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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
| commit | 2aa4a82499d4becd2284cdb482213d541b8804dd (patch) | |
| tree | b80bf8bf13c3766139fbacc530efd0dd9d54394c /media/libpng | |
| parent | Initial commit. (diff) | |
| download | firefox-2aa4a82499d4becd2284cdb482213d541b8804dd.tar.xz firefox-2aa4a82499d4becd2284cdb482213d541b8804dd.zip | |
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'media/libpng')
49 files changed, 56928 insertions, 0 deletions
diff --git a/media/libpng/ANNOUNCE b/media/libpng/ANNOUNCE new file mode 100644 index 0000000000..ecf9c7043b --- /dev/null +++ b/media/libpng/ANNOUNCE @@ -0,0 +1,47 @@ +libpng 1.6.37 - April 14, 2019 +============================== + +This is a public release of libpng, intended for use in production code. + + +Files available for download +---------------------------- + +Source files with LF line endings (for Unix/Linux): + + * libpng-1.6.37.tar.xz (LZMA-compressed, recommended) + * libpng-1.6.37.tar.gz + +Source files with CRLF line endings (for Windows): + + * lp1637.7z (LZMA-compressed, recommended) + * lp1637.zip + +Other information: + + * README.md + * LICENSE.md + * AUTHORS.md + * TRADEMARK.md + + +Changes since the previous public release (version 1.6.36) +---------------------------------------------------------- + + * Fixed a use-after-free vulnerability (CVE-2019-7317) in png_image_free. + * Fixed a memory leak in the ARM NEON implementation of png_do_expand_palette. + * Fixed a memory leak in pngtest.c. + * Fixed two vulnerabilities (CVE-2018-14048, CVE-2018-14550) in + contrib/pngminus; refactor. + * Changed the license of contrib/pngminus to MIT; refresh makefile and docs. + (Contributed by Willem van Schaik) + * Fixed a typo in the libpng license v2. + (Contributed by Miguel Ojeda) + * Added makefiles for AddressSanitizer-enabled builds. + * Cleaned up various makefiles. + + +Send comments/corrections/commendations to png-mng-implement at lists.sf.net. +Subscription is required; visit +https://lists.sourceforge.net/lists/listinfo/png-mng-implement +to subscribe. diff --git a/media/libpng/AUTHORS b/media/libpng/AUTHORS new file mode 100644 index 0000000000..79a3d10361 --- /dev/null +++ b/media/libpng/AUTHORS @@ -0,0 +1,45 @@ +PNG REFERENCE LIBRARY AUTHORS +============================= + +This is the list of PNG Reference Library ("libpng") Contributing +Authors, for copyright and licensing purposes. + + * Andreas Dilger + * Cosmin Truta + * Dave Martindale + * Eric S. Raymond + * Gilles Vollant + * Glenn Randers-Pehrson + * Greg Roelofs + * Guy Eric Schalnat + * James Yu + * John Bowler + * Kevin Bracey + * Magnus Holmgren + * Mandar Sahastrabuddhe + * Mans Rullgard + * Matt Sarett + * Mike Klein + * Paul Schmidt + * Sam Bushell + * Samuel Williams + * Simon-Pierre Cadieux + * Tim Wegner + * Tom Lane + * Tom Tanner + * Vadim Barkov + * Willem van Schaik + * Zhijie Liang + * Arm Holdings + - Richard Townsend + * Google Inc. + - Matt Sarett + - Mike Klein + +The build projects, the build scripts, the test scripts, and other +files in the "projects", "scripts" and "tests" directories, have other +copyright owners, but are released under the libpng license. + +Some files in the "contrib" directory, and some tools-generated files +that are distributed with libpng, have other copyright owners, and are +released under other open source licenses. diff --git a/media/libpng/CHANGES b/media/libpng/CHANGES new file mode 100644 index 0000000000..f0b0a9342c --- /dev/null +++ b/media/libpng/CHANGES @@ -0,0 +1,6109 @@ +CHANGES - changes for libpng + +version 0.1 [March 29, 1995] + initial work-in-progress release + +version 0.2 [April 1, 1995] + added reader into png.h + fixed small problems in stub file + +version 0.3 [April 8, 1995] + added pull reader + split up pngwrite.c to several files + added pnglib.txt + added example.c + cleaned up writer, adding a few new transformations + fixed some bugs in writer + interfaced with zlib 0.5 + added K&R support + added check for 64 KB blocks for 16 bit machines + +version 0.4 [April 26, 1995] + cleaned up code and commented code + simplified time handling into png_time + created png_color_16 and png_color_8 to handle color needs + cleaned up color type defines + fixed various bugs + made various names more consistent + interfaced with zlib 0.71 + cleaned up zTXt reader and writer (using zlib's Reset functions) + split transformations into pngrtran.c and pngwtran.c + +version 0.5 [April 30, 1995] + interfaced with zlib 0.8 + fixed many reading and writing bugs + saved using 3 spaces instead of tabs + +version 0.6 [May 1, 1995] + first beta release + added png_large_malloc() and png_large_free() + added png_size_t + cleaned up some compiler warnings + added png_start_read_image() + +version 0.7 [June 24, 1995] + cleaned up lots of bugs + finished dithering and other stuff + added test program + changed name from pnglib to libpng + +version 0.71 [June 26, 1995] + changed pngtest.png for zlib 0.93 + fixed error in libpng.txt and example.c + +version 0.8 [August 20, 1995] + cleaned up some bugs + added png_set_filler() + split up pngstub.c into pngmem.c, pngio.c, and pngerror.c + added #define's to remove unwanted code + moved png_info_init() to png.c + added old_size into png_realloc() + added functions to manually set filtering and compression info + changed compression parameters based on image type + optimized filter selection code + added version info + changed external functions passing floats to doubles (k&r problems?) + put all the configurable stuff in pngconf.h + enabled png_set_shift to work with paletted images on read + added png_read_update_info() - updates info structure with transformations + +Version 0.81 [August, 1995] + incorporated Tim Wegner's medium model code (thanks, Tim) + +Version 0.82 [September, 1995] + [unspecified changes] + +Version 0.85 [December, 1995] + added more medium model code (almost everything's a far) + added i/o, error, and memory callback functions + fixed some bugs (16-bit, 4-bit interlaced, etc.) + added first run progressive reader (barely tested) + +Version 0.86 [January, 1996] + fixed bugs + improved documentation + +Version 0.87 [January, 1996] + fixed medium model bugs + fixed other bugs introduced in 0.85 and 0.86 + added some minor documentation + +Version 0.88 [January, 1996] + fixed progressive bugs + replaced tabs with spaces + cleaned up documentation + added callbacks for read/write and warning/error functions + +Version 0.89 [June 5, 1996] + Added new initialization API to make libpng work better with shared libs + we now have png_create_read_struct(), png_create_write_struct(), + png_create_info_struct(), png_destroy_read_struct(), and + png_destroy_write_struct() instead of the separate calls to + malloc and png_read_init(), png_info_init(), and png_write_init() + Changed warning/error callback functions to fix bug - this means you + should use the new initialization API if you were using the old + png_set_message_fn() calls, and that the old API no longer exists + so that people are aware that they need to change their code + Changed filter selection API to allow selection of multiple filters + since it didn't work in previous versions of libpng anyways + Optimized filter selection code + Fixed png_set_background() to allow using an arbitrary RGB color for + paletted images + Fixed gamma and background correction for paletted images, so + png_correct_palette is not needed unless you are correcting an + external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED + in pngconf.h) - if nobody uses this, it may disappear in the future. + Fixed bug with Borland 64K memory allocation (Alexander Lehmann) + Fixed bug in interlace handling (Smarasderagd, I think) + Added more error checking for writing and image to reduce invalid files + Separated read and write functions so that they won't both be linked + into a binary when only reading or writing functionality is used + New pngtest image also has interlacing and zTXt + Updated documentation to reflect new API + +Version 0.89c [June 17, 1996] + Bug fixes. + +Version 0.90 [January, 1997] + Made CRC errors/warnings on critical and ancillary chunks configurable + libpng will use the zlib CRC routines by (compile-time) default + Changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner) + Added external C++ wrapper statements to png.h (Gilles Dauphin) + Allow PNG file to be read when some or all of file signature has already + been read from the beginning of the stream. ****This affects the size + of info_struct and invalidates all programs that use a shared libpng**** + Fixed png_filler() declarations + Fixed? background color conversions + Fixed order of error function pointers to match documentation + Current chunk name is now available in png_struct to reduce the number + of nearly identical error messages (will simplify multi-lingual + support when available) + Try to get ready for unknown-chunk callback functions: + - previously read critical chunks are flagged, so the chunk handling + routines can determine if the chunk is in the right place + - all chunk handling routines have the same prototypes, so we will + be able to handle all chunks via a callback mechanism + Try to fix Linux "setjmp" buffer size problems + Removed png_large_malloc, png_large_free, and png_realloc functions. + +Version 0.95 [March, 1997] + Fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never + Fixed bug in PNG file signature compares when start != 0 + Changed parameter type of png_set_filler(...filler...) from png_byte + to png_uint_32 + Added test for MACOS to ensure that both math.h and fp.h are not #included + Added macros for libpng to be compiled as a Windows DLL (Andreas Kupries) + Added "packswap" transformation, which changes the endianness of + packed-pixel bytes (Kevin Bracey) + Added "strip_alpha" transformation, which removes the alpha channel of + input images without using it (not necessarily a good idea) + Added "swap_alpha" transformation, which puts the alpha channel in front + of the color bytes instead of after + Removed all implicit variable tests which assume NULL == 0 (I think) + Changed several variables to "png_size_t" to show 16/32-bit limitations + Added new pCAL chunk read/write support + Added experimental filter selection weighting (Greg Roelofs) + Removed old png_set_rgbx() and png_set_xrgb() functions that have been + obsolete for about 2 years now (use png_set_filler() instead) + Added macros to read 16- and 32-bit ints directly from buffer, to be + used only on those systems that support it (namely PowerPC and 680x0) + With some testing, this may become the default for MACOS/PPC systems. + Only calculate CRC on data if we are going to use it + Added macros for zTXt compression type PNG_zTXt_COMPRESSION_??? + Added macros for simple libpng debugging output selectable at compile time + Removed PNG_READ_END_MODE in progressive reader (Smarasderagd) + More description of info_struct in libpng.txt and png.h + More instructions in example.c + More chunk types tested in pngtest.c + Renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be + png_set_<chunk>. We now have corresponding png_get_<chunk> + functions in pngget.c to get information in info_ptr. This isolates + the application from the internal organization of png_info_struct + (good for shared library implementations). + +Version 0.96 [May, 1997] + Fixed serious bug with < 8bpp images introduced in 0.95 + Fixed 256-color transparency bug (Greg Roelofs) + Fixed up documentation (Greg Roelofs, Laszlo Nyul) + Fixed "error" in pngconf.h for Linux setjmp() behavior + Fixed DOS medium model support (Tim Wegner) + Fixed png_check_keyword() for case with error in static string text + Added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul) + Added typecasts to quiet compiler errors + Added more debugging info + +Version 0.97 [January, 1998] + Removed PNG_USE_OWN_CRC capability + Relocated png_set_crc_action from pngrutil.c to pngrtran.c + Fixed typecasts of "new_key", etc. (Andreas Dilger) + Added RFC 1152 [sic] date support + Fixed bug in gamma handling of 4-bit grayscale + Added 2-bit grayscale gamma handling (Glenn R-P) + Added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P) + Minor corrections in libpng.txt + Added simple sRGB support (Glenn R-P) + Easier conditional compiling, e.g., + define PNG_READ/WRITE_NOT_FULLY_SUPPORTED; + all configurable options can be selected from command-line instead + of having to edit pngconf.h (Glenn R-P) + Fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P) + Added more conditions for png_do_background, to avoid changing + black pixels to background when a background is supplied and + no pixels are transparent + Repaired PNG_NO_STDIO behavior + Tested NODIV support and made it default behavior (Greg Roelofs) + Added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler) + Regularized version numbering scheme and bumped shared-library major + version number to 2 to avoid problems with libpng 0.89 apps + (Greg Roelofs) + +Version 0.98 [January, 1998] + Cleaned up some typos in libpng.txt and in code documentation + Fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler) + Cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c + Changed recommendation about file_gamma for PC images to .51 from .45, + in example.c and libpng.txt, added comments to distinguish between + screen_gamma, viewing_gamma, and display_gamma. + Changed all references to RFC1152 to read RFC1123 and changed the + PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED + Added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent) + Changed srgb_intent from png_byte to int to avoid compiler bugs + +Version 0.99 [January 30, 1998] + Free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler) + Fixed a longstanding "packswap" bug in pngtrans.c + Fixed some inconsistencies in pngconf.h that prevented compiling with + PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined + Fixed some typos and made other minor rearrangement of libpng.txt (Andreas) + Changed recommendation about file_gamma for PC images to .50 from .51 in + example.c and libpng.txt, and changed file_gamma for sRGB images to .45 + Added a number of functions to access information from the png structure + png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit) + Added TARGET_MACOS similar to zlib-1.0.8 + Define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined + Added type casting to all png_malloc() function calls + +Version 0.99a [January 31, 1998] + Added type casts and parentheses to all returns that return a value.(Tim W.) + +Version 0.99b [February 4, 1998] + Added type cast png_uint_32 on malloc function calls where needed. + Changed type of num_hist from png_uint_32 to int (same as num_palette). + Added checks for rowbytes overflow, in case png_size_t is less than 32 bits. + Renamed makefile.elf to makefile.lnx. + +Version 0.99c [February 7, 1998] + More type casting. Removed erroneous overflow test in pngmem.c. + Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes. + Added UNIX manual pages libpng.3 (incorporating libpng.txt) and png.5. + +Version 0.99d [February 11, 1998] + Renamed "far_to_near()" "png_far_to_near()" + Revised libpng.3 + Version 99c "buffered" operations didn't work as intended. Replaced them + with png_memcpy_check() and png_memset_check(). + Added many "if (png_ptr == NULL) return" to quell compiler warnings about + unused png_ptr, mostly in pngget.c and pngset.c. + Check for overlength tRNS chunk present when indexed-color PLTE is read. + Cleaned up spelling errors in libpng.3/libpng.txt + Corrected a problem with png_get_tRNS() which returned undefined trans array + +Version 0.99e [February 28, 1998] + Corrected png_get_tRNS() again. + Add parentheses for easier reading of pngget.c, fixed "||" should be "&&". + Touched up example.c to make more of it compileable, although the entire + file still can't be compiled (Willem van Schaik) + Fixed a bug in png_do_shift() (Bryan Tsai) + Added a space in png.h prototype for png_write_chunk_start() + Replaced pngtest.png with one created with zlib 1.1.1 + Changed pngtest to report PASS even when file size is different (Jean-loup G.) + Corrected some logic errors in png_do_invert_alpha() (Chris Patterson) + +Version 0.99f [March 5, 1998] + Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey) + Moved makefiles into a "scripts" directory, and added INSTALL instruction file + Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok) + Added pointers to "note on libpng versions" in makefile.lnx and README + Added row callback feature when reading and writing nonprogressive rows + and added a test of this feature in pngtest.c + Added user transform callbacks, with test of the feature in pngtest.c + +Version 0.99g [March 6, 1998, morning] + Minor changes to pngtest.c to suppress compiler warnings. + Removed "beta" language from documentation. + +Version 0.99h [March 6, 1998, evening] + Minor changes to previous minor changes to pngtest.c + Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED + and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro + Added user transform capability + +Version 1.00 [March 7, 1998] + Changed several typedefs in pngrutil.c + Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik) + Replaced "while(1)" with "for(;;)" + Added PNGARG() to prototypes in pngtest.c and removed some prototypes + Updated some of the makefiles (Tom Lane) + Changed some typedefs (s_start, etc.) in pngrutil.c + Fixed dimensions of "short_months" array in pngwrite.c + Replaced ansi2knr.c with the one from jpeg-v6 + +Version 1.0.0 [March 8, 1998] + Changed name from 1.00 to 1.0.0 (Adam Costello) + Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert) + +Version 1.0.0a [March 9, 1998] + Fixed three bugs in pngrtran.c to make gamma+background handling consistent + (Greg Roelofs) + Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz + for major, minor, and bugfix releases. This is 10001. (Adam Costello, + Tom Lane) + Make months range from 1-12 in png_convert_to_rfc1123 + +Version 1.0.0b [March 13, 1998] + Quieted compiler complaints about two empty "for" loops in pngrutil.c + Minor changes to makefile.s2x + Removed #ifdef/#endif around a png_free() in pngread.c + +Version 1.0.1 [March 14, 1998] + Changed makefile.s2x to reduce security risk of using a relative pathname + Fixed some typos in the documentation (Greg). + Fixed a problem with value of "channels" returned by png_read_update_info() + +Version 1.0.1a [April 21, 1998] + Optimized Paeth calculations by replacing abs() function calls with intrinsics + plus other loop optimizations. Improves avg decoding speed by about 20%. + Commented out i386istic "align" compiler flags in makefile.lnx. + Reduced the default warning level in some makefiles, to make them consistent. + Removed references to IJG and JPEG in the ansi2knr.c copyright statement. + Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation. + Added grayscale and 16-bit capability to png_do_read_filler(). + Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes + too large when writing an image with bit_depth < 8 (Bob Dellaca). + Corrected some bugs in the experimental weighted filtering heuristics. + Moved a misplaced pngrutil code block that truncates tRNS if it has more + than num_palette entries -- test was done before num_palette was defined. + Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins). + Changed compiler flags in makefile.wat for better optimization + (Pawel Mrochen). + +Version 1.0.1b [May 2, 1998] + Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg). + Relocated the png_composite macros from pngrtran.c to png.h (Greg). + Added makefile.sco (contributed by Mike Hopkirk). + Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a. + Fixed a bug in pngrtran.c that would set channels=5 under some circumstances. + More work on the Paeth-filtering, achieving imperceptible speedup + (A Kleinert). + More work on loop optimization which may help when compiled with C++ + compilers. + Added warnings when people try to use transforms they've defined out. + Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran. + Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg) + +Version 1.0.1c [May 11, 1998] + Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for + filler bytes should have been 0xff instead of 0xf. + Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images. + Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED + out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h + Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED, + for consistency, in pngconf.h + Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier + to remove unwanted capabilities via the compile line + Made some corrections to grammar (which, it's) in documentation (Greg). + Corrected example.c, use of row_pointers in png_write_image(). + +Version 1.0.1d [May 24, 1998] + Corrected several statements that used side effects illegally in pngrutil.c + and pngtrans.c, that were introduced in version 1.0.1b + Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert) + More corrections to example.c, use of row_pointers in png_write_image() + and png_read_rows(). + Added pngdll.mak and pngdef.pas to scripts directory, contributed by + Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5 + Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.) + Changed several loops from count-down to count-up, for consistency. + +Version 1.0.1e [June 6, 1998] + Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and + added warnings when people try to set png_read_fn and png_write_fn in + the same structure. + Added a test such that png_do_gamma will be done when num_trans==0 + for truecolor images that have defined a background. This corrects an + error that was introduced in libpng-0.90 that can cause gamma processing + to be skipped. + Added tests in png.h to include "trans" and "trans_values" in structures + when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined. + Add png_free(png_ptr->time_buffer) in png_destroy_read_struct() + Moved png_convert_to_rfc_1123() from pngwrite.c to png.c + Added capability for user-provided malloc_fn() and free_fn() functions, + and revised pngtest.c to demonstrate their use, replacing the + PNGTEST_DEBUG_MEM feature. + Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner). + +Version 1.0.2 [June 14, 1998] + Fixed two bugs in makefile.bor . + +Version 1.0.2a [December 30, 1998] + Replaced and extended code that was removed from png_set_filler() in 1.0.1a. + Fixed a bug in png_do_filler() that made it fail to write filler bytes in + the left-most pixel of each row (Kevin Bracey). + Changed "static pngcharp tIME_string" to "static char tIME_string[30]" + in pngtest.c (Duncan Simpson). + Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk + even when no tIME chunk was present in the source file. + Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit. + Fixed a problem in png_read_push_finish_row(), which would not skip some + passes that it should skip, for images that are less than 3 pixels high. + Interchanged the order of calls to png_do_swap() and png_do_shift() + in pngwtran.c (John Cromer). + Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h . + Changed "bad adaptive filter type" from error to warning in pngrutil.c . + Fixed a documentation error about default filtering with 8-bit indexed-color. + Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO + (L. Peter Deutsch). + Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions. + Added png_get_copyright() and png_get_header_version() functions. + Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c + Added information about debugging in libpng.txt and libpng.3 . + Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and + makefile.sco. + Removed lines after Dynamic Dependencies" in makefile.aco . + Revised makefile.dec to make a shared library (Jeremie Petit). + Removed trailing blanks from all files. + +Version 1.0.2a [January 6, 1999] + Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h + Added "if" tests to silence complaints about unused png_ptr in png.h and png.c + Changed "check_if_png" function in example.c to return true (nonzero) if PNG. + Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig() + which is obsolete. + +Version 1.0.3 [January 14, 1999] + Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice) + Added a statement of Y2K compliance in png.h, libpng.3, and Y2KINFO. + +Version 1.0.3a [August 12, 1999] + Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning + if an attempt is made to read an interlaced image when it's not supported. + Added check if png_ptr->trans is defined before freeing it in pngread.c + Modified the Y2K statement to include versions back to version 0.71 + Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c + Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments) + Replaced leading blanks with tab characters in makefile.hux + Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents. + Changed (float)red and (float)green to (double)red, (double)green + in png_set_rgb_to_gray() to avoid "promotion" problems in AIX. + Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey). + Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt). + Updated documentation to refer to the PNG-1.2 specification. + Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c + in makefile.knr, INSTALL, and README (L. Peter Deutsch) + Fixed bugs in calculation of the length of rowbytes when adding alpha + channels to 16-bit images, in pngrtran.c (Chris Nokleberg) + Added function png_set_user_transform_info() to store user_transform_ptr, + user_depth, and user_channels into the png_struct, and a function + png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg) + Added function png_set_empty_plte_permitted() to make libpng useable + in MNG applications. + Corrected the typedef for png_free_ptr in png.h (Jesse Jones). + Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be + consistent with PNG-1.2, and allow variance of 500 before complaining. + Added assembler code contributed by Intel in file pngvcrd.c and modified + makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation, + Gilles Vollant) + Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy. + Added some aliases for png_set_expand() in pngrtran.c, namely + png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS() + (Greg Roelofs, in "PNG: The Definitive Guide"). + Added makefile.beo for BEOS on X86, contributed by Sander Stok. + +Version 1.0.3b [August 26, 1999] + Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h + Changed leading blanks to tabs in all makefiles. + Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code. + Made alternate versions of png_set_expand() in pngrtran.c, namely + png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha + (Greg Roelofs, in "PNG: The Definitive Guide"). Deleted the 1.0.3a aliases. + Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h + Revised calculation of num_blocks in pngmem.c to avoid a potentially + negative shift distance, whose results are undefined in the C language. + Added a check in pngset.c to prevent writing multiple tIME chunks. + Added a check in pngwrite.c to detect invalid small window_bits sizes. + +Version 1.0.3d [September 4, 1999] + Fixed type casting of igamma in pngrutil.c + Added new png_expand functions to scripts/pngdef.pas and pngos2.def + Added a demo read_user_transform_fn that examines the row filters in pngtest.c + +Version 1.0.4 [September 24, 1999, not distributed publicly] + Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined + Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h + Made several minor corrections to pngtest.c + Renamed the makefiles with longer but more user friendly extensions. + Copied the PNG copyright and license to a separate LICENSE file. + Revised documentation, png.h, and example.c to remove reference to + "viewing_gamma" which no longer appears in the PNG specification. + Revised pngvcrd.c to use MMX code for interlacing only on the final pass. + Updated pngvcrd.c to use the faster C filter algorithms from libpng-1.0.1a + Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX + assembler code) and makefile.vcwin32 (doesn't). + Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING) + Added a copy of pngnow.png to the distribution. + +Version 1.0.4a [September 25, 1999] + Increase max_pixel_depth in pngrutil.c if a user transform needs it. + Changed several division operations to right-shifts in pngvcrd.c + +Version 1.0.4b [September 30, 1999] + Added parentheses in line 3732 of pngvcrd.c + Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1 + +Version 1.0.4c [October 1, 1999] + Added a "png_check_version" function in png.c and pngtest.c that will generate + a helpful compiler error if an old png.h is found in the search path. + Changed type of png_user_transform_depth|channels from int to png_byte. + Added "Libpng is OSI Certified Open Source Software" statement to png.h + +Version 1.0.4d [October 6, 1999] + Changed 0.45 to 0.45455 in png_set_sRGB() + Removed unused PLTE entries from pngnow.png + Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly. + +Version 1.0.4e [October 10, 1999] + Fixed sign error in pngvcrd.c (Greg Roelofs) + Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P) + +Version 1.0.4f [October 15, 1999] + Surrounded example.c code with #if 0 .. #endif to prevent people from + inadvertently trying to compile it. + Changed png_get_header_version() from a function to a macro in png.h + Added type casting mostly in pngrtran.c and pngwtran.c + Removed some pointless "ptr = NULL" in pngmem.c + Added a "contrib" directory containing the source code from Greg's book. + +Version 1.0.5 [October 15, 1999] + Minor editing of the INSTALL and README files. + +Version 1.0.5a [October 23, 1999] + Added contrib/pngsuite and contrib/pngminus (Willem van Schaik) + Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans) + Further optimization and bugfix of pngvcrd.c + Revised pngset.c so that it does not allocate or free memory in the user's + text_ptr structure. Instead, it makes its own copy. + Created separate write_end_info_struct in pngtest.c for a more severe test. + Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak. + +Version 1.0.5b [November 23, 1999] + Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and + PNG_FLAG_WROTE_tIME from flags to mode. + Added png_write_info_before_PLTE() function. + Fixed some typecasting in contrib/gregbook/*.c + Updated scripts/makevms.com and added makevms.com to contrib/gregbook + and contrib/pngminus (Martin Zinser) + +Version 1.0.5c [November 26, 1999] + Moved png_get_header_version from png.h to png.c, to accommodate ansi2knr. + Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to + accommodate making DLL's: Moved usr_png_ver from global variable to function + png_get_header_ver() in png.c. Moved png_sig to png_sig_bytes in png.c and + eliminated use of png_sig in pngwutil.c. Moved the various png_CHNK arrays + into pngtypes.h. Eliminated use of global png_pass arrays. Declared the + png_CHNK and png_pass arrays to be "const". Made the global arrays + available to applications (although none are used in libpng itself) when + PNG_NO_GLOBAL_ARRAYS is not defined or when PNG_GLOBAL_ARRAYS is defined. + Removed some extraneous "-I" from contrib/pngminus/makefile.std + Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2. + Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3 + +Version 1.0.5d [November 29, 1999] + Add type cast (png_const_charp) two places in png.c + Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays. + Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available + to applications a macro "PNG_USE_LOCAL_ARRAYS". + comment out (with #ifdef) all the new declarations when + PNG_USE_GLOBAL_ARRAYS is defined. + Added PNG_EXPORT_VAR macro to accommodate making DLL's. + +Version 1.0.5e [November 30, 1999] + Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text + structure; refactored the inflate/deflate support to make adding new chunks + with trailing compressed parts easier in the future, and added new functions + png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP, + png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond). + NOTE: Applications that write text chunks MUST define png_text->lang + before calling png_set_text(). It must be set to NULL if you want to + write tEXt or zTXt chunks. If you want your application to be able to + run with older versions of libpng, use + + #ifdef PNG_iTXt_SUPPORTED + png_text[i].lang = NULL; + #endif + + Changed png_get_oFFs() and png_set_oFFs() to use signed rather than unsigned + offsets (Eric S. Raymond). + Combined PNG_READ_cHNK_SUPPORTED and PNG_WRITE_cHNK_SUPPORTED macros into + PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED + macros, leaving the separate macros also available. + Removed comments on #endifs at the end of many short, non-nested #if-blocks. + +Version 1.0.5f [December 6, 1999] + Changed makefile.solaris to issue a warning about potential problems when + the ucb "ld" is in the path ahead of the ccs "ld". + Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3. + Added sCAL chunk support (Eric S. Raymond). + +Version 1.0.5g [December 7, 1999] + Fixed "png_free_spallettes" typo in png.h + Added code to handle new chunks in pngpread.c + Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block + Added "translated_key" to png_text structure and png_write_iTXt(). + Added code in pngwrite.c to work around a newly discovered zlib bug. + +Version 1.0.5h [December 10, 1999] + NOTE: regarding the note for version 1.0.5e, the following must also + be included in your code: + png_text[i].translated_key = NULL; + Unknown chunk handling is now supported. + Option to eliminate all floating point support was added. Some new + fixed-point functions such as png_set_gAMA_fixed() were added. + Expanded tabs and removed trailing blanks in source files. + +Version 1.0.5i [December 13, 1999] + Added some type casts to silence compiler warnings. + Renamed "png_free_spalette" to "png_free_spalettes" for consistency. + Removed leading blanks from a #define in pngvcrd.c + Added some parameters to the new png_set_keep_unknown_chunks() function. + Added a test for up->location != 0 in the first instance of writing + unknown chunks in pngwrite.c + Changed "num" to "i" in png_free_spalettes() and png_free_unknowns() to + prevent recursion. + Added png_free_hIST() function. + Various patches to fix bugs in the sCAL and integer cHRM processing, + and to add some convenience macros for use with sCAL. + +Version 1.0.5j [December 21, 1999] + Changed "unit" parameter of png_write_sCAL from png_byte to int, to work + around buggy compilers. + Added new type "png_fixed_point" for integers that hold float*100000 values + Restored backward compatibility of tEXt/zTXt chunk processing: + Restored the first four members of png_text to the same order as v.1.0.5d. + Added members "lang_key" and "itxt_length" to png_text struct. Set + text_length=0 when "text" contains iTXt data. Use the "compression" + member to distinguish among tEXt/zTXt/iTXt types. Added + PNG_ITXT_COMPRESSION_NONE (1) and PNG_ITXT_COMPRESSION_zTXt(2) macros. + The "Note" above, about backward incompatibility of libpng-1.0.5e, no + longer applies. + Fixed png_read|write_iTXt() to read|write parameters in the right order, + and to write the iTXt chunk after IDAT if it appears in the end_ptr. + Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs) + Reversed the order of trying to write floating-point and fixed-point gAMA. + +Version 1.0.5k [December 27, 1999] + Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))" + Added png_handle_as_unknown() function (Glenn) + Added png_free_chunk_list() function and chunk_list and num_chunk_list members + of png_ptr. + Eliminated erroneous warnings about multiple sPLT chunks and sPLT-after-PLTE. + Fixed a libpng-1.0.5h bug in pngrutil.c that was issuing erroneous warnings + about ignoring incorrect gAMA with sRGB (gAMA was in fact not ignored) + Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR). + Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is. + Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP(). + +Version 1.0.5l [January 1, 2000] + Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr() + for setting a callback function to handle unknown chunks and for + retrieving the associated user pointer (Glenn). + +Version 1.0.5m [January 7, 2000] + Added high-level functions png_read_png(), png_write_png(), png_free_pixels(). + +Version 1.0.5n [January 9, 2000] + Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its + own memory for info_ptr->palette. This makes it safe for the calling + application to free its copy of the palette any time after it calls + png_set_PLTE(). + +Version 1.0.5o [January 20, 2000] + Cosmetic changes only (removed some trailing blanks and TABs) + +Version 1.0.5p [January 31, 2000] + Renamed pngdll.mak to makefile.bd32 + Cosmetic changes in pngtest.c + +Version 1.0.5q [February 5, 2000] + Relocated the makefile.solaris warning about PATH problems. + Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg) + Revised makefile.gcmmx + Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros + +Version 1.0.5r [February 7, 2000] + Removed superfluous prototype for png_get_itxt from png.h + Fixed a bug in pngrtran.c that improperly expanded the background color. + Return *num_text=0 from png_get_text() when appropriate, and fix documentation + of png_get_text() in libpng.txt/libpng.3. + +Version 1.0.5s [February 18, 2000] + Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the + new error handler that's planned for the next libpng release, and changed + example.c, pngtest.c, and contrib programs to use this macro. + Revised some of the DLL-export macros in pngconf.h (Greg Roelofs) + Fixed a bug in png_read_png() that caused it to fail to expand some images + that it should have expanded. + Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions + in pngget.c + Changed the allocation of palette, history, and trans arrays back to + the version 1.0.5 method (linking instead of copying) which restores + backward compatibility with version 1.0.5. Added some remarks about + that in example.c. Added "free_me" member to info_ptr and png_ptr + and added png_free_data() function. + Updated makefile.linux and makefile.gccmmx to make directories conditionally. + Made cosmetic changes to pngasmrd.h + Added png_set_rows() and png_get_rows(), for use with png_read|write_png(). + Modified png_read_png() to allocate info_ptr->row_pointers only if it + hasn't already been allocated. + +Version 1.0.5t [March 4, 2000] + Changed png_jmp_env() migration aiding macro to png_jmpbuf(). + Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c + Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when + PNG_FLAG_HAVE_CHUNK_HEADER was moved into png_ptr->mode in version 1.0.5b + Files in contrib/gregbook were revised to use png_jmpbuf() and to select + a 24-bit visual if one is available, and to allow abbreviated options. + Files in contrib/pngminus were revised to use the png_jmpbuf() macro. + Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s + +Version 1.0.5u [March 5, 2000] + Simplified the code that detects old png.h in png.c and pngtest.c + Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp) + Increased precision of rgb_to_gray calculations from 8 to 15 bits and + added png_set_rgb_to_gray_fixed() function. + Added makefile.bc32 (32-bit Borland C++, C mode) + +Version 1.0.5v [March 11, 2000] + Added some parentheses to the png_jmpbuf macro definition. + Updated references to the zlib home page, which has moved to freesoftware.com. + Corrected bugs in documentation regarding png_read_row() and png_write_row(). + Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt. + Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3, + revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin) + +Version 1.0.6 [March 20, 2000] + Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c + Added makefile.sggcc (SGI IRIX with gcc) + +Version 1.0.6d [April 7, 2000] + Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO + Added data_length parameter to png_decompress_chunk() function + Revised documentation to remove reference to abandoned png_free_chnk functions + Fixed an error in png_rgb_to_gray_fixed() + Revised example.c, usage of png_destroy_write_struct(). + Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file + Added a check for info_ptr->free_me&PNG_FREE_TEXT when freeing text in png.c + Simplify png_sig_bytes() function to remove use of non-ISO-C strdup(). + +Version 1.0.6e [April 9, 2000] + Added png_data_freer() function. + In the code that checks for over-length tRNS chunks, added check of + info_ptr->num_trans as well as png_ptr->num_trans (Matthias Benckmann) + Minor revisions of libpng.txt/libpng.3. + Check for existing data and free it if the free_me flag is set, in png_set_*() + and png_handle_*(). + Only define PNG_WEIGHTED_FILTERS_SUPPORTED when PNG_FLOATING_POINT_SUPPORTED + is defined. + Changed several instances of PNG_NO_CONSOLE_ID to PNG_NO_STDIO in pngrutil.c + and mentioned the purposes of the two macros in libpng.txt/libpng.3. + +Version 1.0.6f [April 14, 2000] + Revised png_set_iCCP() and png_set_rows() to avoid prematurely freeing data. + Add checks in png_set_text() for NULL members of the input text structure. + Revised libpng.txt/libpng.3. + Removed superfluous prototype for png_set_iTXt from png.h + Removed "else" from pngread.c, after png_error(), and changed "0" to "length". + Changed several png_errors about malformed ancillary chunks to png_warnings. + +Version 1.0.6g [April 24, 2000] + Added png_pass-* arrays to pnggccrd.c when PNG_USE_LOCAL_ARRAYS is defined. + Relocated paragraph about png_set_background() in libpng.3/libpng.txt + and other revisions (Matthias Benckmann) + Relocated info_ptr->free_me, png_ptr->free_me, and other info_ptr and + png_ptr members to restore binary compatibility with libpng-1.0.5 + (breaks compatibility with libpng-1.0.6). + +Version 1.0.6h [April 24, 2000] + Changed shared library so-number pattern from 2.x.y.z to xy.z (this builds + libpng.so.10 & libpng.so.10.6h instead of libpng.so.2 & libpng.so.2.1.0.6h) + This is a temporary change for test purposes. + +Version 1.0.6i [May 2, 2000] + Rearranged some members at the end of png_info and png_struct, to put + unknown_chunks_num and free_me within the original size of the png_structs + and free_me, png_read_user_fn, and png_free_fn within the original png_info, + because some old applications allocate the structs directly instead of + using png_create_*(). + Added documentation of user memory functions in libpng.txt/libpng.3 + Modified png_read_png so that it will use user_allocated row_pointers + if present, unless free_me directs that it be freed, and added description + of the use of png_set_rows() and png_get_rows() in libpng.txt/libpng.3. + Added PNG_LEGACY_SUPPORTED macro, and #ifdef out all new (since version + 1.00) members of png_struct and png_info, to regain binary compatibility + when you define this macro. Capabilities lost in this event + are user transforms (new in version 1.0.0),the user transform pointer + (new in version 1.0.2), rgb_to_gray (new in 1.0.5), iCCP, sCAL, sPLT, + the high-level interface, and unknown chunks support (all new in 1.0.6). + This was necessary because of old applications that allocate the structs + directly as authors were instructed to do in libpng-0.88 and earlier, + instead of using png_create_*(). + Added modes PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT which + can be used to detect codes that directly allocate the structs, and + code to check these modes in png_read_init() and png_write_init() and + generate a libpng error if the modes aren't set and PNG_LEGACY_SUPPORTED + was not defined. + Added makefile.intel and updated makefile.watcom (Pawel Mrochen) + +Version 1.0.6j [May 3, 2000] + Overloaded png_read_init() and png_write_init() with macros that convert + calls to png_read_init_2() or png_write_init_2() that check the version + and structure sizes. + +Version 1.0.7beta11 [May 7, 2000] + Removed the new PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT modes + which are no longer used. + Eliminated the three new members of png_text when PNG_LEGACY_SUPPORTED is + defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXt_SUPPORTED + is defined. + Made PNG_NO_READ|WRITE_iTXt the default setting, to avoid memory + overrun when old applications fill the info_ptr->text structure directly. + Added PNGAPI macro, and added it to the definitions of all exported functions. + Relocated version macro definitions ahead of the includes of zlib.h and + pngconf.h in png.h. + +Version 1.0.7beta12 [May 12, 2000] + Revised pngset.c to avoid a problem with expanding the png_debug macro. + Deleted some extraneous defines from pngconf.h + Made PNG_NO_CONSOLE_IO the default condition when PNG_BUILD_DLL is defined. + Use MSC _RPTn debugging instead of fprintf if _MSC_VER is defined. + Added png_access_version_number() function. + Check for mask&PNG_FREE_CHNK (for TEXT, SCAL, PCAL) in png_free_data(). + Expanded libpng.3/libpng.txt information about png_data_freer(). + +Version 1.0.7beta14 [May 17, 2000] (beta13 was not published) + Changed pnggccrd.c and pngvcrd.c to handle bad adaptive filter types as + warnings instead of errors, as pngrutil.c does. + Set the PNG_INFO_IDAT valid flag in png_set_rows() so png_write_png() + will actually write IDATs. + Made the default PNG_USE_LOCAL_ARRAYS depend on PNG_DLL instead of WIN32. + Make png_free_data() ignore its final parameter except when freeing data + that can have multiple instances (text, sPLT, unknowns). + Fixed a new bug in png_set_rows(). + Removed info_ptr->valid tests from png_free_data(), as in version 1.0.5. + Added png_set_invalid() function. + Fixed incorrect illustrations of png_destroy_write_struct() in example.c. + +Version 1.0.7beta15 [May 30, 2000] + Revised the deliberately erroneous Linux setjmp code in pngconf.h to produce + fewer error messages. + Rearranged checks for Z_OK to check the most likely path first in pngpread.c + and pngwutil.c. + Added checks in pngtest.c for png_create_*() returning NULL, and mentioned + in libpng.txt/libpng.3 the need for applications to check this. + Changed names of png_default_*() functions in pngtest to pngtest_*(). + Changed return type of png_get_x|y_offset_*() from png_uint_32 to png_int_32. + Fixed some bugs in the unused PNG_INCH_CONVERSIONS functions in pngget.c + Set each pointer to NULL after freeing it in png_free_data(). + Worked around a problem in pngconf.h; AIX's strings.h defines an "index" + macro that conflicts with libpng's png_color_16.index. (Dimitri + Papadapoulos) + Added "msvc" directory with MSVC++ project files (Simon-Pierre Cadieux). + +Version 1.0.7beta16 [June 4, 2000] + Revised the workaround of AIX string.h "index" bug. + Added a check for overlength PLTE chunk in pngrutil.c. + Added PNG_NO_POINTER_INDEXING macro to use array-indexing instead of pointer + indexing in pngrutil.c and pngwutil.c to accommodate a buggy compiler. + Added a warning in png_decompress_chunk() when it runs out of data, e.g. + when it tries to read an erroneous PhotoShop iCCP chunk. + Added PNG_USE_DLL macro. + Revised the copyright/disclaimer/license notice. + Added contrib/msvctest directory + +Version 1.0.7rc1 [June 9, 2000] + Corrected the definition of PNG_TRANSFORM_INVERT_ALPHA (0x0400 not 0x0200) + Added contrib/visupng directory (Willem van Schaik) + +Version 1.0.7beta18 [June 23, 2000] + Revised PNGAPI definition, and pngvcrd.c to work with __GCC__ + and do not redefine PNGAPI if it is passed in via a compiler directive. + Revised visupng/PngFile.c to remove returns from within the Try block. + Removed leading underscores from "_PNG_H" and "_PNG_SAVE_BSD_SOURCE" macros. + Updated contrib/visupng/cexcept.h to version 1.0.0. + Fixed bugs in pngwrite.c and pngwutil.c that prevented writing iCCP chunks. + +Version 1.0.7rc2 [June 28, 2000] + Updated license to include disclaimers required by UCITA. + Fixed "DJBPP" typo in pnggccrd.c introduced in beta18. + +Version 1.0.7 [July 1, 2000] + Revised the definition of "trans_values" in libpng.3/libpng.txt + +Version 1.0.8beta1 [July 8, 2000] + Added png_free(png_ptr, key) two places in pngpread.c to stop memory leaks. + Changed PNG_NO_STDIO to PNG_NO_CONSOLE_IO, several places in pngrutil.c and + pngwutil.c. + Changed PNG_EXPORT_VAR to use PNG_IMPEXP, in pngconf.h. + Removed unused "#include <assert.h>" from png.c + Added WindowsCE support. + Revised pnggccrd.c to work with gcc-2.95.2 and in the Cygwin environment. + +Version 1.0.8beta2 [July 10, 2000] + Added project files to the wince directory and made further revisions + of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE. + +Version 1.0.8beta3 [July 11, 2000] + Only set the PNG_FLAG_FREE_TRNS or PNG_FREE_TRNS flag in png_handle_tRNS() + for indexed-color input files to avoid potential double-freeing trans array + under some unusual conditions; problem was introduced in version 1.0.6f. + Further revisions to pngtest.c and files in the wince subdirectory. + +Version 1.0.8beta4 [July 14, 2000] + Added the files pngbar.png and pngbar.jpg to the distribution. + Added makefile.cygwin, and cygwin support in pngconf.h + Added PNG_NO_ZALLOC_ZERO macro (makes png_zalloc skip zeroing memory) + +Version 1.0.8rc1 [July 16, 2000] + Revised png_debug() macros and statements to eliminate compiler warnings. + +Version 1.0.8 [July 24, 2000] + Added png_flush() in pngwrite.c, after png_write_IEND(). + Updated makefile.hpux to build a shared library. + +Version 1.0.9beta1 [November 10, 2000] + Fixed typo in scripts/makefile.hpux + Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser) + Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser) + Changed "cdrom.com" in documentation to "libpng.org" + Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg). + Changed type of "params" from voidp to png_voidp in png_read|write_png(). + Make sure PNGAPI and PNG_IMPEXP are defined in pngconf.h. + Revised the 3 instances of WRITEFILE in pngtest.c. + Relocated "msvc" and "wince" project subdirectories into "dll" subdirectory. + Updated png.rc in dll/msvc project + Revised makefile.dec to define and use LIBPATH and INCPATH + Increased size of global png_libpng_ver[] array from 12 to 18 chars. + Made global png_libpng_ver[], png_sig[] and png_pass_*[] arrays const. + Removed duplicate png_crc_finish() from png_handle_bKGD() function. + Added a warning when application calls png_read_update_info() multiple times. + Revised makefile.cygwin + Fixed bugs in iCCP support in pngrutil.c and pngwutil.c. + Replaced png_set_empty_plte_permitted() with png_permit_mng_features(). + +Version 1.0.9beta2 [November 19, 2000] + Renamed the "dll" subdirectory "projects". + Added borland project files to "projects" subdirectory. + Set VS_FF_PRERELEASE and VS_FF_PATCHED flags in msvc/png.rc when appropriate. + Add error message in png_set_compression_buffer_size() when malloc fails. + +Version 1.0.9beta3 [November 23, 2000] + Revised PNG_LIBPNG_BUILD_TYPE macro in png.h, used in the msvc project. + Removed the png_flush() in pngwrite.c that crashes some applications + that don't set png_output_flush_fn. + Added makefile.macosx and makefile.aix to scripts directory. + +Version 1.0.9beta4 [December 1, 2000] + Change png_chunk_warning to png_warning in png_check_keyword(). + Increased the first part of msg buffer from 16 to 18 in png_chunk_error(). + +Version 1.0.9beta5 [December 15, 2000] + Added support for filter method 64 (for PNG datastreams embedded in MNG). + +Version 1.0.9beta6 [December 18, 2000] + Revised png_set_filter() to accept filter method 64 when appropriate. + Added new PNG_HAVE_PNG_SIGNATURE bit to png_ptr->mode and use it to + help prevent applications from using MNG features in PNG datastreams. + Added png_permit_mng_features() function. + Revised libpng.3/libpng.txt. Changed "filter type" to "filter method". + +Version 1.0.9rc1 [December 23, 2000] + Revised test for PNG_HAVE_PNG_SIGNATURE in pngrutil.c + Fixed error handling of unknown compression type in png_decompress_chunk(). + In pngconf.h, define __cdecl when _MSC_VER is defined. + +Version 1.0.9beta7 [December 28, 2000] + Changed PNG_TEXT_COMPRESSION_zTXt to PNG_COMPRESSION_TYPE_BASE several places. + Revised memory management in png_set_hIST and png_handle_hIST in a backward + compatible manner. PLTE and tRNS were revised similarly. + Revised the iCCP chunk reader to ignore trailing garbage. + +Version 1.0.9beta8 [January 12, 2001] + Moved pngasmrd.h into pngconf.h. + Improved handling of out-of-spec garbage iCCP chunks generated by PhotoShop. + +Version 1.0.9beta9 [January 15, 2001] + Added png_set_invalid, png_permit_mng_features, and png_mmx_supported to + wince and msvc project module definition files. + Minor revision of makefile.cygwin. + Fixed bug with progressive reading of narrow interlaced images in pngpread.c + +Version 1.0.9beta10 [January 16, 2001] + Do not typedef png_FILE_p in pngconf.h when PNG_NO_STDIO is defined. + Fixed "png_mmx_supported" typo in project definition files. + +Version 1.0.9beta11 [January 19, 2001] + Updated makefile.sgi to make shared library. + Removed png_mmx_support() function and disabled PNG_MNG_FEATURES_SUPPORTED + by default, for the benefit of DLL forward compatibility. These will + be re-enabled in version 1.2.0. + +Version 1.0.9rc2 [January 22, 2001] + Revised cygwin support. + +Version 1.0.9 [January 31, 2001] + Added check of cygwin's ALL_STATIC in pngconf.h + Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos. + +Version 1.0.10beta1 [March 14, 2001] + Revised makefile.dec, makefile.sgi, and makefile.sggcc; added makefile.hpgcc. + Reformatted libpng.3 to eliminate bad line breaks. + Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c + Added prototype for png_mmx_support() near the top of pnggccrd.c + Moved some error checking from png_handle_IHDR to png_set_IHDR. + Added PNG_NO_READ_SUPPORTED and PNG_NO_WRITE_SUPPORTED macros. + Revised png_mmx_support() function in pnggccrd.c + Restored version 1.0.8 PNG_WRITE_EMPTY_PLTE_SUPPORTED behavior in pngwutil.c + Fixed memory leak in contrib/visupng/PngFile.c + Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version) + Added warnings when retrieving or setting gamma=0. + Increased the first part of msg buffer from 16 to 18 in png_chunk_warning(). + +Version 1.0.10rc1 [March 23, 2001] + Changed all instances of memcpy, strcpy, and strlen to png_memcpy, png_strcpy, + and png_strlen. + Revised png_mmx_supported() function in pnggccrd.c to return proper value. + Fixed bug in progressive reading (pngpread.c) with small images (height < 8). + +Version 1.0.10 [March 30, 2001] + Deleted extraneous space (introduced in 1.0.9) from line 42 of makefile.cygwin + Added beos project files (Chris Herborth) + +Version 1.0.11beta1 [April 3, 2001] + Added type casts on several png_malloc() calls (Dimitri Papadapoulos). + Removed a no-longer needed AIX work-around from pngconf.h + Changed several "//" single-line comments to C-style in pnggccrd.c + +Version 1.0.11beta2 [April 11, 2001] + Removed PNGAPI from several functions whose prototypes did not have PNGAPI. + Updated scripts/pngos2.def + +Version 1.0.11beta3 [April 14, 2001] + Added checking the results of many instances of png_malloc() for NULL + +Version 1.0.11beta4 [April 20, 2001] + Undid the changes from version 1.0.11beta3. Added a check for NULL return + from user's malloc_fn(). + Removed some useless type casts of the NULL pointer. + Added makefile.netbsd + +Version 1.0.11 [April 27, 2001] + Revised makefile.netbsd + +Version 1.0.12beta1 [May 14, 2001] + Test for Windows platform in pngconf.h when including malloc.h (Emmanuel Blot) + Updated makefile.cygwin and handling of Cygwin's ALL_STATIC in pngconf.h + Added some never-to-be-executed code in pnggccrd.c to quiet compiler warnings. + Eliminated the png_error about apps using png_read|write_init(). Instead, + libpng will reallocate the png_struct and info_struct if they are too small. + This retains future binary compatibility for old applications written for + libpng-0.88 and earlier. + +Version 1.2.0beta1 [May 6, 2001] + Bumped DLLNUM to 2. + Re-enabled PNG_MNG_FEATURES_SUPPORTED and enabled PNG_ASSEMBLER_CODE_SUPPORTED + by default. + Added runtime selection of MMX features. + Added png_set_strip_error_numbers function and related macros. + +Version 1.2.0beta2 [May 7, 2001] + Finished merging 1.2.0beta1 with version 1.0.11 + Added a check for attempts to read or write PLTE in grayscale PNG datastreams. + +Version 1.2.0beta3 [May 17, 2001] + Enabled user memory function by default. + Modified png_create_struct so it passes user mem_ptr to user memory allocator. + Increased png_mng_features flag from png_byte to png_uint_32. + Bumped shared-library (so-number) and dll-number to 3. + +Version 1.2.0beta4 [June 23, 2001] + Check for missing profile length field in iCCP chunk and free chunk_data + in case of truncated iCCP chunk. + Bumped shared-library number to 3 in makefile.sgi and makefile.sggcc + Bumped dll-number from 2 to 3 in makefile.cygwin + Revised contrib/gregbook/rpng*-x.c to avoid a memory leak and to exit cleanly + if user attempts to run it on an 8-bit display. + Updated contrib/gregbook + Use png_malloc instead of png_zalloc to allocate palette in pngset.c + Updated makefile.ibmc + Added some typecasts to eliminate gcc 3.0 warnings. Changed prototypes + of png_write_oFFS width and height from png_uint_32 to png_int_32. + Updated example.c + Revised prototypes for png_debug_malloc and png_debug_free in pngtest.c + +Version 1.2.0beta5 [August 8, 2001] + Revised contrib/gregbook + Revised makefile.gcmmx + Revised pnggccrd.c to conditionally compile some thread-unsafe code only + when PNG_THREAD_UNSAFE_OK is defined. + Added tests to prevent pngwutil.c from writing a bKGD or tRNS chunk with + value exceeding 2^bit_depth-1 + Revised makefile.sgi and makefile.sggcc + Replaced calls to fprintf(stderr,...) with png_warning() in pnggccrd.c + Removed restriction that do_invert_mono only operate on 1-bit opaque files + +Version 1.2.0 [September 1, 2001] + Changed a png_warning() to png_debug() in pnggccrd.c + Fixed contrib/gregbook/rpng-x.c, rpng2-x.c to avoid crash with XFreeGC(). + +Version 1.2.1beta1 [October 19, 2001] + Revised makefile.std in contrib/pngminus + Include background_1 in png_struct regardless of gamma support. + Revised makefile.netbsd and makefile.macosx, added makefile.darwin. + Revised example.c to provide more details about using row_callback(). + +Version 1.2.1beta2 [October 25, 2001] + Added type cast to each NULL appearing in a function call, except for + WINCE functions. + Added makefile.so9. + +Version 1.2.1beta3 [October 27, 2001] + Removed type casts from all NULLs. + Simplified png_create_struct_2(). + +Version 1.2.1beta4 [November 7, 2001] + Revised png_create_info_struct() and png_creat_struct_2(). + Added error message if png_write_info() was omitted. + Type cast NULLs appearing in function calls when _NO_PROTO or + PNG_TYPECAST_NULL is defined. + +Version 1.2.1rc1 [November 24, 2001] + Type cast NULLs appearing in function calls except when PNG_NO_TYPECAST_NULL + is defined. + Changed typecast of "size" argument to png_size_t in pngmem.c calls to + the user malloc_fn, to agree with the prototype in png.h + Added a pop/push operation to pnggccrd.c, to preserve Eflag (Maxim Sobolev) + Updated makefile.sgi to recognize LIBPATH and INCPATH. + Updated various makefiles so "make clean" does not remove previous major + version of the shared library. + +Version 1.2.1rc2 [December 4, 2001] + Always allocate 256-entry internal palette, hist, and trans arrays, to + avoid out-of-bounds memory reference caused by invalid PNG datastreams. + Added a check for prefix_length > data_length in iCCP chunk handler. + +Version 1.2.1 [December 7, 2001] + None. + +Version 1.2.2beta1 [February 22, 2002] + Fixed a bug with reading the length of iCCP profiles (Larry Reeves). + Revised makefile.linux, makefile.gcmmx, and makefile.sgi to generate + libpng.a, libpng12.so (not libpng.so.3), and libpng12/png.h + Revised makefile.darwin to remove "-undefined suppress" option. + Added checks for gamma and chromaticity values over 21474.83, which exceed + the limit for PNG unsigned 32-bit integers when encoded. + Revised calls to png_create_read_struct() and png_create_write_struct() + for simpler debugging. + Revised png_zalloc() so zlib handles errors (uses PNG_FLAG_MALLOC_NULL_MEM_OK) + +Version 1.2.2beta2 [February 23, 2002] + Check chunk_length and idat_size for invalid (over PNG_MAX_UINT) lengths. + Check for invalid image dimensions in png_get_IHDR. + Added missing "fi;" in the install target of the SGI makefiles. + Added install-static to all makefiles that make shared libraries. + Always do gamma compensation when image is partially transparent. + +Version 1.2.2beta3 [March 7, 2002] + Compute background.gray and background_1.gray even when color_type is RGB + in case image gets reduced to gray later. + Modified shared-library makefiles to install pkgconfig/libpngNN.pc. + Export (with PNGAPI) png_zalloc, png_zfree, and png_handle_as_unknown + Removed unused png_write_destroy_info prototype from png.h + Eliminated incorrect use of width_mmx from pnggccrd.c in pixel_bytes == 8 case + Added install-shared target to all makefiles that make shared libraries. + Stopped a double free of palette, hist, and trans when not using free_me. + Added makefile.32sunu for Sun Ultra 32 and makefile.64sunu for Sun Ultra 64. + +Version 1.2.2beta4 [March 8, 2002] + Compute background.gray and background_1.gray even when color_type is RGB + in case image gets reduced to gray later (Jason Summers). + Relocated a misplaced /bin/rm in the "install-shared" makefile targets + Added PNG_1_0_X macro which can be used to build a 1.0.x-compatible library. + +Version 1.2.2beta5 [March 26, 2002] + Added missing PNGAPI to several function definitions. + Check for invalid bit_depth or color_type in png_get_IHDR(), and + check for missing PLTE or IHDR in png_push_read_chunk() (Matthias Clasen). + Revised iTXt support to accept NULL for lang and lang_key. + Compute gamma for color components of background even when color_type is gray. + Changed "()" to "{}" in scripts/libpng.pc.in. + Revised makefiles to put png.h and pngconf.h only in $prefix/include/libpngNN + Revised makefiles to make symlink to libpng.so.NN in addition to libpngNN.so + +Version 1.2.2beta6 [March 31, 2002] + +Version 1.0.13beta1 [March 31, 2002] + Prevent png_zalloc() from trying to memset memory that it failed to acquire. + Add typecasts of PNG_MAX_UINT in pngset_cHRM_fixed() (Matt Holgate). + Ensure that the right function (user or default) is used to free the + png_struct after an error in png_create_read_struct_2(). + +Version 1.2.2rc1 [April 7, 2002] + +Version 1.0.13rc1 [April 7, 2002] + Save the ebx register in pnggccrd.c (Sami Farin) + Add "mem_ptr = png_ptr->mem_ptr" in png_destroy_write_struct() (Paul Gardner). + Updated makefiles to put headers in include/libpng and remove old include/*.h. + +Version 1.2.2 [April 15, 2002] + +Version 1.0.13 [April 15, 2002] + Revised description of png_set_filter() in libpng.3/libpng.txt. + Revised makefile.netbsd and added makefile.neNNbsd and makefile.freebsd + +Version 1.0.13patch01 [April 17, 2002] + +Version 1.2.2patch01 [April 17, 2002] + Changed ${PNGMAJ}.${PNGVER} bug to ${PNGVER} in makefile.sgi and + makefile.sggcc + Fixed VER -> PNGVER typo in makefile.macosx and added install-static to + install + Added install: target to makefile.32sunu and makefile.64sunu + +Version 1.0.13patch03 [April 18, 2002] + +Version 1.2.2patch03 [April 18, 2002] + Revised 15 makefiles to link libpng.a to libpngNN.a and the include libpng + subdirectory to libpngNN subdirectory without the full pathname. + Moved generation of libpng.pc from "install" to "all" in 15 makefiles. + +Version 1.2.3rc1 [April 28, 2002] + Added install-man target to 15 makefiles (Dimitri Papadopolous-Orfanos). + Added $(DESTDIR) feature to 24 makefiles (Tim Mooney) + Fixed bug with $prefix, should be $(prefix) in makefile.hpux. + Updated cygwin-specific portion of pngconf.h and revised makefile.cygwin + Added a link from libpngNN.pc to libpng.pc in 15 makefiles. + Added links from include/libpngNN/*.h to include/*.h in 24 makefiles. + Revised makefile.darwin to make relative links without full pathname. + Added setjmp() at the end of png_create_*_struct_2() in case user forgets + to put one in their application. + Restored png_zalloc() and png_zfree() prototypes to version 1.2.1 and + removed them from module definition files. + +Version 1.2.3rc2 [May 1, 2002] + Fixed bug in reporting number of channels in pngget.c and pngset.c, + that was introduced in version 1.2.2beta5. + Exported png_zalloc(), png_zfree(), png_default_read(), png_default_write(), + png_default_flush(), and png_push_fill_buffer() and included them in + module definition files. + Added "libpng.pc" dependency to the "install-shared" target in 15 makefiles. + +Version 1.2.3rc3 [May 1, 2002] + Revised prototype for png_default_flush() + Remove old libpng.pc and libpngNN.pc before installing new ones. + +Version 1.2.3rc4 [May 2, 2002] + Typos in *.def files (png_default_read|write -> png_default_read|write_data) + In makefiles, changed rm libpng.NN.pc to rm libpngNN.pc + Added libpng-config and libpngNN-config and modified makefiles to install + them. + Changed $(MANPATH) to $(DESTDIR)$(MANPATH) in makefiles + Added "Win32 DLL VB" configuration to projects/msvc/libpng.dsp + +Version 1.2.3rc5 [May 11, 2002] + Changed "error" and "message" in prototypes to "error_message" and + "warning_message" to avoid namespace conflict. + Revised 15 makefiles to build libpng-config from libpng-config-*.in + Once more restored png_zalloc and png_zfree to regular nonexported form. + Restored png_default_read|write_data, png_default_flush, png_read_fill_buffer + to nonexported form, but with PNGAPI, and removed them from module def + files. + +Version 1.2.3rc6 [May 14, 2002] + Removed "PNGAPI" from png_zalloc() and png_zfree() in png.c + Changed "Gz" to "Gd" in projects/msvc/libpng.dsp and zlib.dsp. + Removed leftover libpng-config "sed" script from four makefiles. + Revised libpng-config creating script in 16 makefiles. + +Version 1.2.3 [May 22, 2002] + Revised libpng-config target in makefile.cygwin. + Removed description of png_set_mem_fn() from documentation. + Revised makefile.freebsd. + Minor cosmetic changes to 15 makefiles, e.g., $(DI) = $(DESTDIR)/$(INCDIR). + Revised projects/msvc/README.txt + Changed -lpng to -lpngNN in LDFLAGS in several makefiles. + +Version 1.2.4beta1 [May 24, 2002] + Added libpng.pc and libpng-config to "all:" target in 16 makefiles. + Fixed bug in 16 makefiles: $(DESTDIR)/$(LIBPATH) to $(DESTDIR)$(LIBPATH) + Added missing "\" before closing double quote in makefile.gcmmx. + Plugged various memory leaks; added png_malloc_warn() and png_set_text_2() + functions. + +Version 1.2.4beta2 [June 25, 2002] + Plugged memory leak of png_ptr->current_text (Matt Holgate). + Check for buffer overflow before reading CRC in pngpread.c (Warwick Allison) + Added -soname to the loader flags in makefile.dec, makefile.sgi, and + makefile.sggcc. + Added "test-installed" target to makefile.linux, makefile.gcmmx, + makefile.sgi, and makefile.sggcc. + +Version 1.2.4beta3 [June 28, 2002] + Plugged memory leak of row_buf in pngtest.c when there is a png_error(). + Detect buffer overflow in pngpread.c when IDAT is corrupted with extra data. + Added "test-installed" target to makefile.32sunu, makefile.64sunu, + makefile.beos, makefile.darwin, makefile.dec, makefile.macosx, + makefile.solaris, makefile.hpux, makefile.hpgcc, and makefile.so9. + +Version 1.2.4rc1 and 1.0.14rc1 [July 2, 2002] + Added "test-installed" target to makefile.cygwin and makefile.sco. + Revised pnggccrd.c to be able to back out version 1.0.x via PNG_1_0_X macro. + +Version 1.2.4 and 1.0.14 [July 8, 2002] + Changed png_warning() to png_error() when width is too large to process. + +Version 1.2.4patch01 [July 20, 2002] + Revised makefile.cygwin to use DLL number 12 instead of 13. + +Version 1.2.5beta1 [August 6, 2002] + Added code to contrib/gregbook/readpng2.c to ignore unused chunks. + Replaced toucan.png in contrib/gregbook (it has been corrupt since 1.0.11) + Removed some stray *.o files from contrib/gregbook. + Changed png_error() to png_warning() about "Too much data" in pngpread.c + and about "Extra compressed data" in pngrutil.c. + Prevent png_ptr->pass from exceeding 7 in png_push_finish_row(). + Updated makefile.hpgcc + Updated png.c and pnggccrd.c handling of return from png_mmx_support() + +Version 1.2.5beta2 [August 15, 2002] + Only issue png_warning() about "Too much data" in pngpread.c when avail_in + is nonzero. + Updated makefiles to install a separate libpng.so.3 with its own rpath. + +Version 1.2.5rc1 and 1.0.15rc1 [August 24, 2002] + Revised makefiles to not remove previous minor versions of shared libraries. + +Version 1.2.5rc2 and 1.0.15rc2 [September 16, 2002] + Revised 13 makefiles to remove "-lz" and "-L$(ZLIBLIB)", etc., from shared + library loader directive. + Added missing "$OBJSDLL" line to makefile.gcmmx. + Added missing "; fi" to makefile.32sunu. + +Version 1.2.5rc3 and 1.0.15rc3 [September 18, 2002] + Revised libpng-config script. + +Version 1.2.5 and 1.0.15 [October 3, 2002] + Revised makefile.macosx, makefile.darwin, makefile.hpgcc, and makefile.hpux, + and makefile.aix. + Relocated two misplaced PNGAPI lines in pngtest.c + +Version 1.2.6beta1 [October 22, 2002] + Commented out warning about uninitialized mmx_support in pnggccrd.c. + Changed "IBMCPP__" flag to "__IBMCPP__" in pngconf.h. + Relocated two more misplaced PNGAPI lines in pngtest.c + Fixed memory overrun bug in png_do_read_filler() with 16-bit datastreams, + introduced in version 1.0.2. + Revised makefile.macosx, makefile.dec, makefile.aix, and makefile.32sunu. + +Version 1.2.6beta2 [November 1, 2002] + Added libpng-config "--ldopts" output. + Added "AR=ar" and "ARFLAGS=rc" and changed "ar rc" to "$(AR) $(ARFLAGS)" + in makefiles. + +Version 1.2.6beta3 [July 18, 2004] + Reverted makefile changes from version 1.2.6beta2 and some of the changes + from version 1.2.6beta1; these will be postponed until version 1.2.7. + Version 1.2.6 is going to be a simple bugfix release. + Changed the one instance of "ln -sf" to "ln -f -s" in each Sun makefile. + Fixed potential overrun in pngerror.c by using strncpy instead of memcpy. + Added "#!/bin/sh" at the top of configure, for recognition of the + 'x' flag under Cygwin (Cosmin). + Optimized vacuous tests that silence compiler warnings, in png.c (Cosmin). + Added support for PNG_USER_CONFIG, in pngconf.h (Cosmin). + Fixed the special memory handler for Borland C under DOS, in pngmem.c + (Cosmin). + Removed some spurious assignments in pngrutil.c (Cosmin). + Replaced 65536 with 65536L, and 0xffff with 0xffffL, to silence warnings + on 16-bit platforms (Cosmin). + Enclosed shift op expressions in parentheses, to silence warnings (Cosmin). + Used proper type png_fixed_point, to avoid problems on 16-bit platforms, + in png_handle_sRGB() (Cosmin). + Added compression_type to png_struct, and optimized the window size + inside the deflate stream (Cosmin). + Fixed definition of isnonalpha(), in pngerror.c and pngrutil.c (Cosmin). + Fixed handling of unknown chunks that come after IDAT (Cosmin). + Allowed png_error() and png_warning() to work even if png_ptr == NULL + (Cosmin). + Replaced row_info->rowbytes with row_bytes in png_write_find_filter() + (Cosmin). + Fixed definition of PNG_LIBPNG_VER_DLLNUM (Simon-Pierre). + Used PNG_LIBPNG_VER and PNG_LIBPNG_VER_STRING instead of the hardcoded + values in png.c (Simon-Pierre, Cosmin). + Initialized png_libpng_ver[] with PNG_LIBPNG_VER_STRING (Simon-Pierre). + Replaced PNG_LIBPNG_VER_MAJOR with PNG_LIBPNG_VER_DLLNUM in png.rc + (Simon-Pierre). + Moved the definition of PNG_HEADER_VERSION_STRING near the definitions + of the other PNG_LIBPNG_VER_... symbols in png.h (Cosmin). + Relocated #ifndef PNGAPI guards in pngconf.h (Simon-Pierre, Cosmin). + Updated scripts/makefile.vc(a)win32 (Cosmin). + Updated the MSVC project (Simon-Pierre, Cosmin). + Updated the Borland C++ Builder project (Cosmin). + Avoided access to asm_flags in pngvcrd.c, if PNG_1_0_X is defined (Cosmin). + Commented out warning about uninitialized mmx_support in pngvcrd.c (Cosmin). + Removed scripts/makefile.bd32 and scripts/pngdef.pas (Cosmin). + Added extra guard around inclusion of Turbo C memory headers, in pngconf.h + (Cosmin). + Renamed projects/msvc/ to projects/visualc6/, and projects/borland/ to + projects/cbuilder5/ (Cosmin). + Moved projects/visualc6/png32ms.def to scripts/pngw32.def, + and projects/visualc6/png.rc to scripts/pngw32.rc (Cosmin). + Added projects/visualc6/pngtest.dsp; removed contrib/msvctest/ (Cosmin). + Changed line endings to DOS style in cbuilder5 and visualc6 files, even + in the tar.* distributions (Cosmin). + Updated contrib/visupng/VisualPng.dsp (Cosmin). + Updated contrib/visupng/cexcept.h to version 2.0.0 (Cosmin). + Added a separate distribution with "configure" and supporting files (Junichi). + +Version 1.2.6beta4 [July 28, 2004] + Added user ability to change png_size_t via a PNG_SIZE_T macro. + Added png_sizeof() and png_convert_size() functions. + Added PNG_SIZE_MAX (maximum value of a png_size_t variable. + Added check in png_malloc_default() for (size_t)size != (png_uint_32)size + which would indicate an overflow. + Changed sPLT failure action from png_error to png_warning and abandon chunk. + Changed sCAL and iCCP failures from png_error to png_warning and abandon. + Added png_get_uint_31(png_ptr, buf) function. + Added PNG_UINT_32_MAX macro. + Renamed PNG_MAX_UINT to PNG_UINT_31_MAX. + Made png_zalloc() issue a png_warning and return NULL on potential + overflow. + Turn on PNG_NO_ZALLOC_ZERO by default in version 1.2.x + Revised "clobber list" in pnggccrd.c so it will compile under gcc-3.4. + Revised Borland portion of png_malloc() to return NULL or issue + png_error() according to setting of PNG_FLAG_MALLOC_NULL_MEM_OK. + Added PNG_NO_SEQUENTIAL_READ_SUPPORTED macro to conditionally remove + sequential read support. + Added some "#if PNG_WRITE_SUPPORTED" blocks. + Added #ifdef to remove some redundancy in png_malloc_default(). + Use png_malloc instead of png_zalloc to allocate the palette. + +Version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004] + Fixed buffer overflow vulnerability (CVE-2004-0597) in png_handle_tRNS(). + Fixed NULL dereference vulnerability (CVE-2004-0598) in png_handle_iCCP(). + Fixed integer overflow vulnerability (CVE-2004-0599) in png_read_png(). + Fixed some harmless bugs in png_handle_sBIT, etc, that would cause + duplicate chunk types to go undetected. + Fixed some timestamps in the -config version + Rearranged order of processing of color types in png_handle_tRNS(). + Added ROWBYTES macro to calculate rowbytes without integer overflow. + Updated makefile.darwin and removed makefile.macosx from scripts directory. + Imposed default one million column, one-million row limits on the image + dimensions, and added png_set_user_limits() function to override them. + Revised use of PNG_SET_USER_LIMITS_SUPPORTED macro. + Fixed wrong cast of returns from png_get_user_width|height_max(). + Changed some "keep the compiler happy" from empty statements to returns, + Revised libpng.txt to remove 1.2.x stuff from the 1.0.x distribution + +Version 1.0.16rc2 and 1.2.6rc2 [August 7, 2004] + Revised makefile.darwin and makefile.solaris. Removed makefile.macosx. + Revised pngtest's png_debug_malloc() to use png_malloc() instead of + png_malloc_default() which is not supposed to be exported. + Fixed off-by-one error in one of the conversions to PNG_ROWBYTES() in + pngpread.c. Bug was introduced in 1.2.6rc1. + Fixed bug in RGB to RGBX transformation introduced in 1.2.6rc1. + Fixed old bug in RGB to Gray transformation. + Fixed problem with 64-bit compilers by casting arguments to abs() + to png_int_32. + Changed "ln -sf" to "ln -f -s" in three makefiles (solaris, sco, so9). + Changed "HANDLE_CHUNK_*" to "PNG_HANDLE_CHUNK_*" (Cosmin) + Added "-@/bin/rm -f $(DL)/$(LIBNAME).so.$(PNGMAJ)" to 15 *NIX makefiles. + Added code to update the row_info->colortype in png_do_read_filler() (MSB). + +Version 1.0.16rc3 and 1.2.6rc3 [August 9, 2004] + Eliminated use of "abs()" in testing cHRM and gAMA values, to avoid + trouble with some 64-bit compilers. Created PNG_OUT_OF_RANGE() macro. + Revised documentation of png_set_keep_unknown_chunks(). + Check handle_as_unknown status in pngpread.c, as in pngread.c previously. + Moved "PNG_HANDLE_CHUNK_*" macros out of PNG_INTERNAL section of png.h + Added "rim" definitions for CONST4 and CONST6 in pnggccrd.c + +Version 1.0.16rc4 and 1.2.6rc4 [August 10, 2004] + Fixed mistake in pngtest.c introduced in 1.2.6rc2 (declaration of + "pinfo" was out of place). + +Version 1.0.16rc5 and 1.2.6rc5 [August 10, 2004] + Moved "PNG_HANDLE_CHUNK_*" macros out of PNG_ASSEMBLER_CODE_SUPPORTED + section of png.h where they were inadvertently placed in version rc3. + +Version 1.2.6 and 1.0.16 [August 15, 2004] + Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1. + +Version 1.2.7beta1 [August 26, 2004] + Removed unused pngasmrd.h file. + Removed references to uu.net for archived files. Added references to + PNG Spec (second edition) and the PNG ISO/IEC Standard. + Added "test-dd" target in 15 makefiles, to run pngtest in DESTDIR. + Fixed bug with "optimized window size" in the IDAT datastream, that + causes libpng to write PNG files with incorrect zlib header bytes. + +Version 1.2.7beta2 [August 28, 2004] + Fixed bug with sCAL chunk and big-endian machines (David Munro). + Undid new code added in 1.2.6rc2 to update the color_type in + png_set_filler(). + Added png_set_add_alpha() that updates color type. + +Version 1.0.17rc1 and 1.2.7rc1 [September 4, 2004] + Revised png_set_strip_filler() to not remove alpha if color_type has alpha. + +Version 1.2.7 and 1.0.17 [September 12, 2004] + Added makefile.hp64 + Changed projects/msvc/png32ms.def to scripts/png32ms.def in makefile.cygwin + +Version 1.2.8beta1 [November 1, 2004] + Fixed bug in png_text_compress() that would fail to complete a large block. + Fixed bug, introduced in libpng-1.2.7, that overruns a buffer during + strip alpha operation in png_do_strip_filler(). + Added PNG_1_2_X definition in pngconf.h + Use #ifdef to comment out png_info_init in png.c and png_read_init in + pngread.c (as of 1.3.0) + +Version 1.2.8beta2 [November 2, 2004] + Reduce color_type to a nonalpha type after strip alpha operation in + png_do_strip_filler(). + +Version 1.2.8beta3 [November 3, 2004] + Revised definitions of PNG_MAX_UINT_32, PNG_MAX_SIZE, and PNG_MAXSUM + +Version 1.2.8beta4 [November 12, 2004] + Fixed (again) definition of PNG_LIBPNG_VER_DLLNUM in png.h (Cosmin). + Added PNG_LIBPNG_BUILD_PRIVATE in png.h (Cosmin). + Set png_ptr->zstream.data_type to Z_BINARY, to avoid unnecessary detection + of data type in deflate (Cosmin). + Deprecated but continue to support SPECIALBUILD and PRIVATEBUILD in favor of + PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING. + +Version 1.2.8beta5 [November 20, 2004] + Use png_ptr->flags instead of png_ptr->transformations to pass + PNG_STRIP_ALPHA info to png_do_strip_filler(), to preserve ABI + compatibility. + Revised handling of SPECIALBUILD, PRIVATEBUILD, + PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING. + +Version 1.2.8rc1 [November 24, 2004] + Moved handling of BUILD macros from pngconf.h to png.h + Added definition of PNG_LIBPNG_BASE_TYPE in png.h, inadvertently + omitted from beta5. + Revised scripts/pngw32.rc + Despammed mailing addresses by masking "@" with "at". + Inadvertently installed a supposedly faster test version of pngrutil.c + +Version 1.2.8rc2 [November 26, 2004] + Added two missing "\" in png.h + Change tests in pngread.c and pngpread.c to + if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) + png_do_read_transformations(png_ptr); + +Version 1.2.8rc3 [November 28, 2004] + Reverted pngrutil.c to version libpng-1.2.8beta5. + Added scripts/makefile.elf with supporting code in pngconf.h for symbol + versioning (John Bowler). + +Version 1.2.8rc4 [November 29, 2004] + Added projects/visualc7 (Simon-pierre). + +Version 1.2.8rc5 [November 29, 2004] + Fixed new typo in scripts/pngw32.rc + +Version 1.2.8 [December 3, 2004] + Removed projects/visualc7, added projects/visualc71. + +Version 1.2.9beta1 [February 21, 2006] + Initialized some structure members in pngwutil.c to avoid gcc-4.0.0 complaints + Revised man page and libpng.txt to make it clear that one should not call + png_read_end or png_write_end after png_read_png or png_write_png. + Updated references to png-mng-implement mailing list. + Fixed an incorrect typecast in pngrutil.c + Added PNG_NO_READ_SUPPORTED conditional for making a write-only library. + Added PNG_NO_WRITE_INTERLACING_SUPPORTED conditional. + Optimized alpha-inversion loops in pngwtran.c + Moved test for nonzero gamma outside of png_build_gamma_table() in pngrtran.c + Make sure num_trans is <= 256 before copying data in png_set_tRNS(). + Make sure num_palette is <= 256 before copying data in png_set_PLTE(). + Interchanged order of write_swap_alpha and write_invert_alpha transforms. + Added parentheses in the definition of PNG_LIBPNG_BUILD_TYPE (Cosmin). + Optimized zlib window flag (CINFO) in contrib/pngsuite/*.png (Cosmin). + Updated scripts/makefile.bc32 for Borland C++ 5.6 (Cosmin). + Exported png_get_uint_32, png_save_uint_32, png_get_uint_16, png_save_uint_16, + png_get_int_32, png_save_int_32, png_get_uint_31 (Cosmin). + Added type cast (png_byte) in png_write_sCAL() (Cosmin). + Fixed scripts/makefile.cygwin (Christian Biesinger, Cosmin). + Default iTXt support was inadvertently enabled. + +Version 1.2.9beta2 [February 21, 2006] + Check for png_rgb_to_gray and png_gray_to_rgb read transformations before + checking for png_read_dither in pngrtran.c + Revised checking of chromaticity limits to accommodate extended RGB + colorspace (John Denker). + Changed line endings in some of the project files to CRLF, even in the + "Unix" tar distributions (Cosmin). + Made png_get_int_32 and png_save_int_32 always available (Cosmin). + Updated scripts/pngos2.def, scripts/pngw32.def and projects/wince/png32ce.def + with the newly exported functions. + Eliminated distributions without the "configure" script. + Updated INSTALL instructions. + +Version 1.2.9beta3 [February 24, 2006] + Fixed CRCRLF line endings in contrib/visupng/VisualPng.dsp + Made libpng.pc respect EXEC_PREFIX (D. P. Kreil, J. Bowler) + Removed reference to pngasmrd.h from Makefile.am + Renamed CHANGES to ChangeLog. + Renamed LICENSE to COPYING. + Renamed ANNOUNCE to NEWS. + Created AUTHORS file. + +Version 1.2.9beta4 [March 3, 2006] + Changed definition of PKGCONFIG from $prefix/lib to $libdir in configure.ac + Reverted to filenames LICENSE and ANNOUNCE; removed AUTHORS and COPYING. + Removed newline from the end of some error and warning messages. + Removed test for sqrt() from configure.ac and configure. + Made swap tables in pngtrans.c PNG_CONST (Carlo Bramix). + Disabled default iTXt support that was inadvertently enabled in + libpng-1.2.9beta1. + Added "OS2" to list of systems that don't need underscores, in pnggccrd.c + Removed libpng version and date from *.c files. + +Version 1.2.9beta5 [March 4, 2006] + Removed trailing blanks from source files. + Put version and date of latest change in each source file, and changed + copyright year accordingly. + More cleanup of configure.ac, Makefile.am, and associated scripts. + Restored scripts/makefile.elf which was inadvertently deleted. + +Version 1.2.9beta6 [March 6, 2006] + Fixed typo (RELEASE) in configuration files. + +Version 1.2.9beta7 [March 7, 2006] + Removed libpng.vers and libpng.sym from libpng12_la_SOURCES in Makefile.am + Fixed inconsistent #ifdef's around png_sig_bytes() and png_set_sCAL_s() + in png.h. + Updated makefile.elf as suggested by debian. + Made cosmetic changes to some makefiles, adding LN_SF and other macros. + Made some makefiles accept "exec_prefix". + +Version 1.2.9beta8 [March 9, 2006] + Fixed some "#if defined (..." which should be "#if defined(..." + Bug introduced in libpng-1.2.8. + Fixed inconsistency in definition of png_default_read_data() + Restored blank that was lost from makefile.sggcc "clean" target in beta7. + Revised calculation of "current" and "major" for irix in ltmain.sh + Changed "mkdir" to "MKDIR_P" in some makefiles. + Separated PNG_EXPAND and PNG_EXPAND_tRNS. + Added png_set_expand_gray_1_2_4_to_8() and deprecated + png_set_gray_1_2_4_to_8() which also expands tRNS to alpha. + +Version 1.2.9beta9 [March 10, 2006] + Include "config.h" in pngconf.h when available. + Added some checks for NULL png_ptr or NULL info_ptr (timeless) + +Version 1.2.9beta10 [March 20, 2006] + Removed extra CR from contrib/visualpng/VisualPng.dsw (Cosmin) + Made pnggccrd.c PIC-compliant (Christian Aichinger). + Added makefile.mingw (Wolfgang Glas). + Revised pngconf.h MMX checking. + +Version 1.2.9beta11 [March 22, 2006] + Fixed out-of-order declaration in pngwrite.c that was introduced in beta9 + Simplified some makefiles by using LIBSO, LIBSOMAJ, and LIBSOVER macros. + +Version 1.2.9rc1 [March 31, 2006] + Defined PNG_USER_PRIVATEBUILD when including "pngusr.h" (Cosmin). + Removed nonsensical assertion check from pngtest.c (Cosmin). + +Version 1.2.9 [April 14, 2006] + Revised makefile.beos and added "none" selector in ltmain.sh + +Version 1.2.10beta1 [April 15, 2006] + Renamed "config.h" to "png_conf.h" and revised Makefile.am to add + -DPNG_BUILDING_LIBPNG to compile directive, and modified pngconf.h + to include png_conf.h only when PNG_BUILDING_LIBPNG is defined. + +Version 1.2.10beta2 [April 15, 2006] + Manually updated Makefile.in and configure. Changed png_conf.h.in + back to config.h. + +Version 1.2.10beta3 [April 15, 2006] + Change png_conf.h back to config.h in pngconf.h. + +Version 1.2.10beta4 [April 16, 2006] + Change PNG_BUILDING_LIBPNG to PNG_CONFIGURE_LIBPNG in config/Makefile*. + +Version 1.2.10beta5 [April 16, 2006] + Added a configure check for compiling assembler code in pnggccrd.c + +Version 1.2.10beta6 [April 17, 2006] + Revised the configure check for pnggccrd.c + Moved -DPNG_CONFIGURE_LIBPNG into @LIBPNG_DEFINES@ + Added @LIBPNG_DEFINES@ to arguments when building libpng.sym + +Version 1.2.10beta7 [April 18, 2006] + Change "exec_prefix=$prefix" to "exec_prefix=$(prefix)" in makefiles. + +Version 1.2.10rc1 [April 19, 2006] + Ensure pngconf.h doesn't define both PNG_USE_PNGGCCRD and PNG_USE_PNGVCRD + Fixed "LN_FS" typo in makefile.sco and makefile.solaris. + +Version 1.2.10rc2 [April 20, 2006] + Added a backslash between -DPNG_CONFIGURE_LIBPNG and -DPNG_NO_ASSEMBLER_CODE + in configure.ac and configure + Made the configure warning about versioned symbols less arrogant. + +Version 1.2.10rc3 [April 21, 2006] + Added a note in libpng.txt that png_set_sig_bytes(8) can be used when + writing an embedded PNG without the 8-byte signature. + Revised makefiles and configure to avoid making links to libpng.so.* + +Version 1.2.10 [April 23, 2006] + Reverted configure to "rc2" state. + +Version 1.2.11beta1 [May 31, 2006] + scripts/libpng.pc.in contained "configure" style version info and would + not work with makefiles. + The shared-library makefiles were linking to libpng.so.0 instead of + libpng.so.3 compatibility as the library. + +Version 1.2.11beta2 [June 2, 2006] + Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid + buffer overflow. + Fixed bug in example.c (png_set_palette_rgb -> png_set_palette_to_rgb) + +Version 1.2.11beta3 [June 5, 2006] + Prepended "#! /bin/sh" to ltmail.sh and contrib/pngminus/*.sh (Cosmin). + Removed the accidental leftover Makefile.in~ (Cosmin). + Avoided potential buffer overflow and optimized buffer in + png_write_sCAL(), png_write_sCAL_s() (Cosmin). + Removed the include directories and libraries from CFLAGS and LDFLAGS + in scripts/makefile.gcc (Nelson A. de Oliveira, Cosmin). + +Version 1.2.11beta4 [June 6, 2006] + Allow zero-length IDAT chunks after the entire zlib datastream, but not + after another intervening chunk type. + +Version 1.0.19rc1, 1.2.11rc1 [June 13, 2006] + Deleted extraneous square brackets from [config.h] in configure.ac + +Version 1.0.19rc2, 1.2.11rc2 [June 14, 2006] + Added prototypes for PNG_INCH_CONVERSIONS functions to png.h + Revised INSTALL and autogen.sh + Fixed typo in several makefiles (-W1 should be -Wl) + Added typedef for png_int_32 and png_uint_32 on 64-bit systems. + +Version 1.0.19rc3, 1.2.11rc3 [June 15, 2006] + Removed the new typedefs for 64-bit systems (delay until version 1.4.0) + Added one zero element to png_gamma_shift[] array in pngrtran.c to avoid + reading out of bounds. + +Version 1.0.19rc4, 1.2.11rc4 [June 15, 2006] + Really removed the new typedefs for 64-bit systems. + +Version 1.0.19rc5, 1.2.11rc5 [June 22, 2006] + Removed png_sig_bytes entry from scripts/pngw32.def + +Version 1.0.19, 1.2.11 [June 26, 2006] + None. + +Version 1.0.20, 1.2.12 [June 27, 2006] + Really increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid + buffer overflow. + +Version 1.2.13beta1 [October 2, 2006] + Removed AC_FUNC_MALLOC from configure.ac + Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h + Change "logical" to "bitwise" throughout documentation. + Detect and fix attempt to write wrong iCCP profile length (CVE-2006-7244) + +Version 1.0.21, 1.2.13 [November 14, 2006] + Fix potential buffer overflow in sPLT chunk handler. + Fix Makefile.am to not try to link to noexistent files. + Check all exported functions for NULL png_ptr. + +Version 1.2.14beta1 [November 17, 2006] + Relocated three misplaced tests for NULL png_ptr. + Built Makefile.in with automake-1.9.6 instead of 1.9.2. + Build configure with autoconf-2.60 instead of 2.59 + +Version 1.2.14beta2 [November 17, 2006] + Added some typecasts in png_zalloc(). + +Version 1.2.14rc1 [November 20, 2006] + Changed "strtod" to "png_strtod" in pngrutil.c + +Version 1.0.22, 1.2.14 [November 27, 2006] + Added missing "$(srcdir)" in Makefile.am and Makefile.in + +Version 1.2.15beta1 [December 3, 2006] + Generated configure with autoconf-2.61 instead of 2.60 + Revised configure.ac to update libpng.pc and libpng-config. + +Version 1.2.15beta2 [December 3, 2006] + Always export MMX asm functions, just stubs if not building pnggccrd.c + +Version 1.2.15beta3 [December 4, 2006] + Add "png_bytep" typecast to profile while calculating length in pngwutil.c + +Version 1.2.15beta4 [December 7, 2006] + Added scripts/CMakeLists.txt + Changed PNG_NO_ASSEMBLER_CODE to PNG_NO_MMX_CODE in scripts, like 1.4.0beta + +Version 1.2.15beta5 [December 7, 2006] + Changed some instances of PNG_ASSEMBLER_* to PNG_MMX_* in pnggccrd.c + Revised scripts/CMakeLists.txt + +Version 1.2.15beta6 [December 13, 2006] + Revised scripts/CMakeLists.txt and configure.ac + +Version 1.2.15rc1 [December 18, 2006] + Revised scripts/CMakeLists.txt + +Version 1.2.15rc2 [December 21, 2006] + Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers. + Added scripts/makefile.nommx + +Version 1.2.15rc3 [December 25, 2006] + Fixed shared library numbering error that was introduced in 1.2.15beta6. + +Version 1.2.15rc4 [December 27, 2006] + Fixed handling of rgb_to_gray when png_ptr->color.gray isn't set. + +Version 1.2.15rc5 [December 31, 2006] + Revised handling of rgb_to_gray. + +Version 1.2.15 [January 5, 2007] + Added some (unsigned long) typecasts in pngtest.c to avoid printing errors. + +Version 1.2.16beta1 [January 6, 2007] + Fix bugs in makefile.nommx + +Version 1.2.16beta2 [January 16, 2007] + Revised scripts/CMakeLists.txt + +Version 1.2.16 [January 31, 2007] + No changes. + +Version 1.2.17beta1 [March 6, 2007] + Revised scripts/CMakeLists.txt to install both shared and static libraries. + Deleted a redundant line from pngset.c. + +Version 1.2.17beta2 [April 26, 2007] + Relocated misplaced test for png_ptr == NULL in pngpread.c + Change "==" to "&" for testing PNG_RGB_TO_GRAY_ERR & PNG_RGB_TO_GRAY_WARN + flags. + Changed remaining instances of PNG_ASSEMBLER_* to PNG_MMX_* + Added pngerror() when write_IHDR fails in deflateInit2(). + Added "const" to some array declarations. + Mention examples of libpng usage in the libpng*.txt and libpng.3 documents. + +Version 1.2.17rc1 [May 4, 2007] + No changes. + +Version 1.2.17rc2 [May 8, 2007] + Moved several PNG_HAVE_* macros out of PNG_INTERNAL because applications + calling set_unknown_chunk_location() need them. + Changed transformation flag from PNG_EXPAND_tRNS to PNG_EXPAND in + png_set_expand_gray_1_2_4_to_8(). + Added png_ptr->unknown_chunk to hold working unknown chunk data, so it + can be free'ed in case of error. Revised unknown chunk handling in + pngrutil.c and pngpread.c to use this structure. + +Version 1.2.17rc3 [May 8, 2007] + Revised symbol-handling in configure script. + +Version 1.2.17rc4 [May 10, 2007] + Revised unknown chunk handling to avoid storing unknown critical chunks. + +Version 1.0.25 [May 15, 2007] +Version 1.2.17 [May 15, 2007] + Added "png_ptr->num_trans=0" before error return in png_handle_tRNS, + to eliminate a vulnerability (CVE-2007-2445, CERT VU#684664) + +Version 1.0.26 [May 15, 2007] +Version 1.2.18 [May 15, 2007] + Reverted the libpng-1.2.17rc3 change to symbol-handling in configure script + +Version 1.2.19beta1 [May 18, 2007] + Changed "const static" to "static PNG_CONST" everywhere, mostly undoing + change of libpng-1.2.17beta2. Changed other "const" to "PNG_CONST" + Changed some handling of unused parameters, to avoid compiler warnings. + "if (unused == NULL) return;" becomes "unused = unused". + +Version 1.2.19beta2 [May 18, 2007] + Only use the valid bits of tRNS value in png_do_expand() (Brian Cartier) + +Version 1.2.19beta3 [May 19, 2007] + Add some "png_byte" typecasts in png_check_keyword() and write new_key + instead of key in zTXt chunk (Kevin Ryde). + +Version 1.2.19beta4 [May 21, 2007] + Add png_snprintf() function and use it in place of sprint() for improved + defense against buffer overflows. + +Version 1.2.19beta5 [May 21, 2007] + Fixed png_handle_tRNS() to only use the valid bits of tRNS value. + Changed handling of more unused parameters, to avoid compiler warnings. + Removed some PNG_CONST in pngwutil.c to avoid compiler warnings. + +Version 1.2.19beta6 [May 22, 2007] + Added some #ifdef PNG_MMX_CODE_SUPPORTED where needed in pngvcrd.c + Added a special "_MSC_VER" case that defines png_snprintf to _snprintf + +Version 1.2.19beta7 [May 22, 2007] + Squelched png_squelch_warnings() in pnggccrd.c and added + an #ifdef PNG_MMX_CODE_SUPPORTED block around the declarations that caused + the warnings that png_squelch_warnings was squelching. + +Version 1.2.19beta8 [May 22, 2007] + Removed __MMX__ from test in pngconf.h. + +Version 1.2.19beta9 [May 23, 2007] + Made png_squelch_warnings() available via PNG_SQUELCH_WARNINGS macro. + Revised png_squelch_warnings() so it might work. + Updated makefile.sgcc and makefile.solaris; added makefile.solaris-x86. + +Version 1.2.19beta10 [May 24, 2007] + Resquelched png_squelch_warnings(), use "__attribute__((used))" instead. + +Version 1.4.0beta1 [April 20, 2006] + Enabled iTXt support (changes png_struct, thus requires so-number change). + Cleaned up PNG_ASSEMBLER_CODE_SUPPORTED vs PNG_MMX_CODE_SUPPORTED + Eliminated PNG_1_0_X and PNG_1_2_X macros. + Removed deprecated functions png_read_init, png_write_init, png_info_init, + png_permit_empty_plte, png_set_gray_1_2_4_to_8, png_check_sig, and + removed the deprecated macro PNG_MAX_UINT. + Moved "PNG_INTERNAL" parts of png.h and pngconf.h into pngintrn.h + Removed many WIN32_WCE #ifdefs (Cosmin). + Reduced dependency on C-runtime library when on Windows (Simon-Pierre) + Replaced sprintf() with png_sprintf() (Simon-Pierre) + +Version 1.4.0beta2 [April 20, 2006] + Revised makefiles and configure to avoid making links to libpng.so.* + Moved some leftover MMX-related defines from pngconf.h to pngintrn.h + Updated scripts/pngos2.def, pngw32.def, and projects/wince/png32ce.def + +Version 1.4.0beta3 [May 10, 2006] + Updated scripts/pngw32.def to comment out MMX functions. + Added PNG_NO_GET_INT_32 and PNG_NO_SAVE_INT_32 macros. + Scripts/libpng.pc.in contained "configure" style version info and would + not work with makefiles. + Revised pngconf.h and added pngconf.h.in, so makefiles and configure can + pass defines to libpng and applications. + +Version 1.4.0beta4 [May 11, 2006] + Revised configure.ac, Makefile.am, and many of the makefiles to write + their defines in pngconf.h. + +Version 1.4.0beta5 [May 15, 2006] + Added a missing semicolon in Makefile.am and Makefile.in + Deleted extraneous square brackets from configure.ac + +Version 1.4.0beta6 [June 2, 2006] + Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid + buffer overflow. + Changed sonum from 0 to 1. + Removed unused prototype for png_check_sig() from png.h + +Version 1.4.0beta7 [June 16, 2006] + Exported png_write_sig (Cosmin). + Optimized buffer in png_handle_cHRM() (Cosmin). + Set pHYs = 2835 x 2835 pixels per meter, and added + sCAL = 0.352778e-3 x 0.352778e-3 meters, in pngtest.png (Cosmin). + Added png_set_benign_errors(), png_benign_error(), png_chunk_benign_error(). + Added typedef for png_int_32 and png_uint_32 on 64-bit systems. + Added "(unsigned long)" typecast on png_uint_32 variables in printf lists. + +Version 1.4.0beta8 [June 22, 2006] + Added demonstration of user chunk support in pngtest.c, to support the + public sTER chunk and a private vpAg chunk. + +Version 1.4.0beta9 [July 3, 2006] + Removed ordinals from scripts/pngw32.def and removed png_info_int and + png_set_gray_1_2_4_to_8 entries. + Inline call of png_get_uint_32() in png_get_uint_31(). + Use png_get_uint_31() to get vpAg width and height in pngtest.c + Removed WINCE and Netware projects. + Removed standalone Y2KINFO file. + +Version 1.4.0beta10 [July 12, 2006] + Eliminated automatic copy of pngconf.h to pngconf.h.in from configure and + some makefiles, because it was not working reliably. Instead, distribute + pngconf.h.in along with pngconf.h and cause configure and some of the + makefiles to update pngconf.h from pngconf.h.in. + Added pngconf.h to DEPENDENCIES in Makefile.am + +Version 1.4.0beta11 [August 19, 2006] + Removed AC_FUNC_MALLOC from configure.ac. + Added a warning when writing iCCP profile with mismatched profile length. + Patched pnggccrd.c to assemble on x86_64 platforms. + Moved chunk header reading into a separate function png_read_chunk_header() + in pngrutil.c. The chunk header (len+sig) is now serialized in a single + operation (Cosmin). + Implemented support for I/O states. Added png_ptr member io_state, and + functions png_get_io_chunk_name() and png_get_io_state() in pngget.c + (Cosmin). + Added png_get_io_chunk_name and png_get_io_state to scripts/*.def (Cosmin). + Renamed scripts/pngw32.* to scripts/pngwin.* (Cosmin). + Removed the include directories and libraries from CFLAGS and LDFLAGS + in scripts/makefile.gcc (Cosmin). + Used png_save_uint_32() to set vpAg width and height in pngtest.c (Cosmin). + Cast to proper type when getting/setting vpAg units in pngtest.c (Cosmin). + Added pngintrn.h to the Visual C++ projects (Cosmin). + Removed scripts/list (Cosmin). + Updated copyright year in scripts/pngwin.def (Cosmin). + Removed PNG_TYPECAST_NULL and used standard NULL consistently (Cosmin). + Disallowed the user to redefine png_size_t, and enforced a consistent use + of png_size_t across libpng (Cosmin). + Changed the type of png_ptr->rowbytes, PNG_ROWBYTES() and friends + to png_size_t (Cosmin). + Removed png_convert_size() and replaced png_sizeof with sizeof (Cosmin). + Removed some unnecessary type casts (Cosmin). + Changed prototype of png_get_compression_buffer_size() and + png_set_compression_buffer_size() to work with png_size_t instead of + png_uint_32 (Cosmin). + Removed png_memcpy_check() and png_memset_check() (Cosmin). + Fixed a typo (png_byte --> png_bytep) in libpng.3 and libpng.txt (Cosmin). + Clarified that png_zalloc() does not clear the allocated memory, + and png_zalloc() and png_zfree() cannot be PNGAPI (Cosmin). + Renamed png_mem_size_t to png_alloc_size_t, fixed its definition in + pngconf.h, and used it in all memory allocation functions (Cosmin). + Renamed pngintrn.h to pngpriv.h, added a comment at the top of the file + mentioning that the symbols declared in that file are private, and + updated the scripts and the Visual C++ projects accordingly (Cosmin). + Removed circular references between pngconf.h and pngconf.h.in in + scripts/makefile.vc*win32 (Cosmin). + Removing trailing '.' from the warning and error messages (Cosmin). + Added pngdefs.h that is built by makefile or configure, instead of + pngconf.h.in (Glenn). + Detect and fix attempt to write wrong iCCP profile length. + +Version 1.4.0beta12 [October 19, 2006] + Changed "logical" to "bitwise" in the documentation. + Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h + Add a typecast to stifle compiler warning in pngrutil.c + +Version 1.4.0beta13 [November 10, 2006] + Fix potential buffer overflow in sPLT chunk handler. + Fix Makefile.am to not try to link to noexistent files. + +Version 1.4.0beta14 [November 15, 2006] + Check all exported functions for NULL png_ptr. + +Version 1.4.0beta15 [November 17, 2006] + Relocated two misplaced tests for NULL png_ptr. + Built Makefile.in with automake-1.9.6 instead of 1.9.2. + Build configure with autoconf-2.60 instead of 2.59 + Add "install: all" in Makefile.am so "configure; make install" will work. + +Version 1.4.0beta16 [November 17, 2006] + Added a typecast in png_zalloc(). + +Version 1.4.0beta17 [December 4, 2006] + Changed "new_key[79] = '\0';" to "(*new_key)[79] = '\0';" in pngwutil.c + Add "png_bytep" typecast to profile while calculating length in pngwutil.c + +Version 1.4.0beta18 [December 7, 2006] + Added scripts/CMakeLists.txt + +Version 1.4.0beta19 [May 16, 2007] + Revised scripts/CMakeLists.txt + Rebuilt configure and Makefile.in with newer tools. + Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers. + Added scripts/makefile.nommx + +Version 1.4.0beta20 [July 9, 2008] + Moved several PNG_HAVE_* macros from pngpriv.h to png.h because applications + calling set_unknown_chunk_location() need them. + Moved several macro definitions from pngpriv.h to pngconf.h + Merge with changes to the 1.2.X branch, as of 1.2.30beta04. + Deleted all use of the MMX assembler code and Intel-licensed optimizations. + Revised makefile.mingw + +Version 1.4.0beta21 [July 21, 2008] + Moved local array "chunkdata" from pngrutil.c to the png_struct, so + it will be freed by png_read_destroy() in case of a read error (Kurt + Christensen). + +Version 1.4.0beta22 [July 21, 2008] + Change "purpose" and "buffer" to png_ptr->chunkdata to avoid memory leaking. + +Version 1.4.0beta23 [July 22, 2008] + Change "chunkdata = NULL" to "png_ptr->chunkdata = NULL" several places in + png_decompress_chunk(). + +Version 1.4.0beta24 [July 25, 2008] + Change all remaining "chunkdata" to "png_ptr->chunkdata" in + png_decompress_chunk(), and remove "chunkdata" from parameter list. + Put a call to png_check_chunk_name() in png_read_chunk_header(). + Revised png_check_chunk_name() to reject a name with a lowercase 3rd byte. + Removed two calls to png_check_chunk_name() occurring later in the process. + Define PNG_NO_ERROR_NUMBERS by default in pngconf.h + +Version 1.4.0beta25 [July 30, 2008] + Added a call to png_check_chunk_name() in pngpread.c + Reverted png_check_chunk_name() to accept a name with a lowercase 3rd byte. + Added png_push_have_buffer() function to pngpread.c + Eliminated PNG_BIG_ENDIAN_SUPPORTED and associated png_get_* macros. + Made inline expansion of png_get_*() optional with PNG_USE_READ_MACROS. + Eliminated all PNG_USELESS_TESTS and PNG_CORRECT_PALETTE_SUPPORTED code. + Synced contrib directory and configure files with libpng-1.2.30beta06. + Eliminated no-longer-used pngdefs.h (but it's still built in the makefiles) + Relocated a misplaced "#endif /* PNG_NO_WRITE_FILTER */" in pngwutil.c + +Version 1.4.0beta26 [August 4, 2008] + Removed png_push_have_buffer() function in pngpread.c. It increased the + compiled library size slightly. + Changed "-Wall" to "-W -Wall" in the CFLAGS in all makefiles (Cosmin Truta) + Declared png_ptr "volatile" in pngread.c and pngwrite.c to avoid warnings. + Updated contrib/visupng/cexcept.h to version 2.0.1 + Added PNG_LITERAL_CHARACTER macros for #, [, and ]. + +Version 1.4.0beta27 [August 5, 2008] + Revised usage of PNG_LITERAL_SHARP in pngerror.c. + Moved newline character from individual png_debug messages into the + png_debug macros. + Allow user to #define their own png_debug, png_debug1, and png_debug2. + +Version 1.4.0beta28 [August 5, 2008] + Revised usage of PNG_LITERAL_SHARP in pngerror.c. + Added PNG_STRING_NEWLINE macro + +Version 1.4.0beta29 [August 9, 2008] + Revised usage of PNG_STRING_NEWLINE to work on non-ISO compilers. + Added PNG_STRING_COPYRIGHT macro. + Added non-ISO versions of png_debug macros. + +Version 1.4.0beta30 [August 14, 2008] + Added premultiplied alpha feature (Volker Wiendl). + +Version 1.4.0beta31 [August 18, 2008] + Moved png_set_premultiply_alpha from pngtrans.c to pngrtran.c + Removed extra crc check at the end of png_handle_cHRM(). Bug introduced + in libpng-1.4.0beta20. + +Version 1.4.0beta32 [August 19, 2008] + Added PNG_WRITE_FLUSH_SUPPORTED block around new png_flush() call. + Revised PNG_NO_STDIO version of png_write_flush() + +Version 1.4.0beta33 [August 20, 2008] + Added png_get|set_chunk_cache_max() to limit the total number of sPLT, + text, and unknown chunks that can be stored. + +Version 1.4.0beta34 [September 6, 2008] + Shortened tIME_string to 29 bytes in pngtest.c + Fixed off-by-one error introduced in png_push_read_zTXt() function in + libpng-1.2.30beta04/pngpread.c (Harald van Dijk) + +Version 1.4.0beta35 [October 6, 2008] + Changed "trans_values" to "trans_color". + Changed so-number from 0 to 14. Some OS do not like 0. + Revised makefile.darwin to fix shared library numbering. + Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8() + in example.c (debian bug report) + +Version 1.4.0beta36 [October 25, 2008] + Sync with tEXt vulnerability fix in libpng-1.2.33rc02. + +Version 1.4.0beta37 [November 13, 2008] + Added png_check_cHRM in png.c and moved checking from pngget.c, pngrutil.c, + and pngwrite.c + +Version 1.4.0beta38 [November 22, 2008] + Added check for zero-area RGB cHRM triangle in png_check_cHRM() and + png_check_cHRM_fixed(). + +Version 1.4.0beta39 [November 23, 2008] + Revised png_warning() to write its message on standard output by default + when warning_fn is NULL. + +Version 1.4.0beta40 [November 24, 2008] + Eliminated png_check_cHRM(). Instead, always use png_check_cHRM_fixed(). + In png_check_cHRM_fixed(), ensure white_y is > 0, and removed redundant + check for all-zero coordinates that is detected by the triangle check. + +Version 1.4.0beta41 [November 26, 2008] + Fixed string vs pointer-to-string error in png_check_keyword(). + Rearranged test expressions in png_check_cHRM_fixed() to avoid internal + overflows. + Added PNG_NO_CHECK_cHRM conditional. + +Version 1.4.0beta42, 43 [December 1, 2008] + Merge png_debug with version 1.2.34beta04. + +Version 1.4.0beta44 [December 6, 2008] + Removed redundant check for key==NULL before calling png_check_keyword() + to ensure that new_key gets initialized and removed extra warning + (Merge with version 1.2.34beta05 -- Arvan Pritchard). + +Version 1.4.0beta45 [December 9, 2008] + In png_write_png(), respect the placement of the filler bytes in an earlier + call to png_set_filler() (Jim Barry). + +Version 1.4.0beta46 [December 10, 2008] + Undid previous change and added PNG_TRANSFORM_STRIP_FILLER_BEFORE and + PNG_TRANSFORM_STRIP_FILLER_AFTER conditionals and deprecated + PNG_TRANSFORM_STRIP_FILLER (Jim Barry). + +Version 1.4.0beta47 [December 15, 2008] + Support for dithering was disabled by default, because it has never + been well tested and doesn't work very well. The code has not + been removed, however, and can be enabled by building libpng with + PNG_READ_DITHER_SUPPORTED defined. + +Version 1.4.0beta48 [February 14, 2009] + Added new exported function png_calloc(). + Combined several instances of png_malloc(); png_memset() into png_calloc(). + Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24 + but was never defined. + +Version 1.4.0beta49 [February 28, 2009] + Added png_fileno() macro to pngconf.h, used in pngwio.c + Corrected order of #ifdef's in png_debug definition in png.h + Fixed bug introduced in libpng-1.4.0beta48 with the memset arguments + for pcal_params. + Fixed order of #ifdef directives in the png_debug defines in png.h + (bug introduced in libpng-1.2.34/1.4.0beta29). + Revised comments in png_set_read_fn() and png_set_write_fn(). + +Version 1.4.0beta50 [March 18, 2009] + Use png_calloc() instead of png_malloc() to allocate big_row_buf when + reading an interlaced file, to avoid a possible UMR. + Undid revision of PNG_NO_STDIO version of png_write_flush(). Users + having trouble with fflush() can build with PNG_NO_WRITE_FLUSH defined + or supply their own flush_fn() replacement. + Revised libpng*.txt and png.h documentation about use of png_write_flush() + and png_set_write_fn(). + Removed fflush() from pngtest.c. + Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h + +Version 1.4.0beta51 [March 21, 2009] + Removed new png_fileno() macro from pngconf.h . + +Version 1.4.0beta52 [March 27, 2009] + Relocated png_do_chop() ahead of building gamma tables in pngrtran.c + This avoids building 16-bit gamma tables unnecessarily. + Removed fflush() from pngtest.c. + Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h + Added a section on differences between 1.0.x and 1.2.x to libpng.3/libpng.txt + +Version 1.4.0beta53 [April 1, 2009] + Removed some remaining MMX macros from pngpriv.h + Fixed potential memory leak of "new_name" in png_write_iCCP() (Ralph Giles) + +Version 1.4.0beta54 [April 13, 2009] + Added "ifndef PNG_SKIP_SETJMP_CHECK" block in pngconf.h to allow + application code writers to bypass the check for multiple inclusion + of setjmp.h when they know that it is safe to ignore the situation. + Eliminated internal use of setjmp() in pngread.c and pngwrite.c + Reordered ancillary chunks in pngtest.png to be the same as what + pngtest now produces, and made some cosmetic changes to pngtest output. + Eliminated deprecated png_read_init_3() and png_write_init_3() functions. + +Version 1.4.0beta55 [April 15, 2009] + Simplified error handling in pngread.c and pngwrite.c by putting + the new png_read_cleanup() and png_write_cleanup() functions inline. + +Version 1.4.0beta56 [April 25, 2009] + Renamed "user_chunk_data" to "my_user_chunk_data" in pngtest.c to suppress + "shadowed declaration" warning from gcc-4.3.3. + Renamed "gamma" to "png_gamma" in pngset.c to avoid "shadowed declaration" + warning about a global "gamma" variable in math.h on some platforms. + +Version 1.4.0beta57 [May 2, 2009] + Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24 + but was never defined (again). + Rebuilt configure scripts with autoconf-2.63 instead of 2.62 + Removed pngprefs.h and MMX from makefiles + +Version 1.4.0beta58 [May 14, 2009] + Changed pngw32.def to pngwin.def in makefile.mingw (typo was introduced + in beta57). + Clarified usage of sig_bit versus sig_bit_p in example.c (Vincent Torri) + +Version 1.4.0beta59 [May 15, 2009] + Reformated sources in libpng style (3-space intentation, comment format) + Fixed typo in libpng docs (PNG_FILTER_AVE should be PNG_FILTER_AVG) + Added sections about the git repository and our coding style to the + documentation + Relocated misplaced #endif in pngwrite.c, sCAL chunk handler. + +Version 1.4.0beta60 [May 19, 2009] + Conditionally compile png_read_finish_row() which is not used by + progressive readers. + Added contrib/pngminim/preader to demonstrate building minimal progressive + decoder, based on contrib/gregbook with embedded libpng and zlib. + +Version 1.4.0beta61 [May 20, 2009] + In contrib/pngminim/*, renamed "makefile.std" to "makefile", since there + is only one makefile in those directories, and revised the README files + accordingly. + More reformatting of comments, mostly to capitalize sentences. + +Version 1.4.0beta62 [June 2, 2009] + Added "#define PNG_NO_WRITE_SWAP" to contrib/pngminim/encoder/pngusr.h + and "define PNG_NO_READ_SWAP" to decoder/pngusr.h and preader/pngusr.h + Reformatted several remaining "else statement" into two lines. + Added a section to the libpng documentation about using png_get_io_ptr() + in configure scripts to detect the presence of libpng. + +Version 1.4.0beta63 [June 15, 2009] + Revised libpng*.txt and libpng.3 to mention calling png_set_IHDR() + multiple times and to specify the sample order in the tRNS chunk, + because the ISO PNG specification has a typo in the tRNS table. + Changed several PNG_UNKNOWN_CHUNK_SUPPORTED to + PNG_HANDLE_AS_UNKNOWN_SUPPORTED, to make the png_set_keep mechanism + available for ignoring known chunks even when not saving unknown chunks. + Adopted preference for consistent use of "#ifdef" and "#ifndef" versus + "#if defined()" and "if !defined()" where possible. + +Version 1.4.0beta64 [June 24, 2009] + Eliminated PNG_LEGACY_SUPPORTED code. + Moved the various unknown chunk macro definitions outside of the + PNG_READ|WRITE_ANCILLARY_CHUNK_SUPPORTED blocks. + +Version 1.4.0beta65 [June 26, 2009] + Added a reference to the libpng license in each file. + +Version 1.4.0beta66 [June 27, 2009] + Refer to the libpng license instead of the libpng license in each file. + +Version 1.4.0beta67 [July 6, 2009] + Relocated INVERT_ALPHA within png_read_png() and png_write_png(). + Added high-level API transform PNG_TRANSFORM_GRAY_TO_RGB. + Added an "xcode" project to the projects directory (Alam Arias). + +Version 1.4.0beta68 [July 19, 2009] + Avoid some tests in filter selection in pngwutil.c + +Version 1.4.0beta69 [July 25, 2009] + Simplified the new filter-selection test. This runs faster in the + common "PNG_ALL_FILTERS" and PNG_FILTER_NONE cases. + Removed extraneous declaration from the new call to png_read_gray_to_rgb() + (bug introduced in libpng-1.4.0beta67). + Fixed up xcode project (Alam Arias) + Added a prototype for png_64bit_product() in png.c + +Version 1.4.0beta70 [July 27, 2009] + Avoid a possible NULL dereference in debug build, in png_set_text_2(). + (bug introduced in libpng-0.95, discovered by Evan Rouault) + +Version 1.4.0beta71 [July 29, 2009] + Rebuilt configure scripts with autoconf-2.64. + +Version 1.4.0beta72 [August 1, 2009] + Replaced *.tar.lzma with *.tar.xz in distribution. Get the xz codec + from <http://tukaani.org/xz>. + +Version 1.4.0beta73 [August 1, 2009] + Reject attempt to write iCCP chunk with negative embedded profile length + (JD Chen) (CVE-2009-5063). + +Version 1.4.0beta74 [August 8, 2009] + Changed png_ptr and info_ptr member "trans" to "trans_alpha". + +Version 1.4.0beta75 [August 21, 2009] + Removed an extra png_debug() recently added to png_write_find_filter(). + Fixed incorrect #ifdef in pngset.c regarding unknown chunk support. + +Version 1.4.0beta76 [August 22, 2009] + Moved an incorrectly located test in png_read_row() in pngread.c + +Version 1.4.0beta77 [August 27, 2009] + Removed lpXYZ.tar.bz2 (with CRLF), KNOWNBUG, libpng-x.y.z-KNOWNBUG.txt, + and the "noconfig" files from the distribution. + Moved CMakeLists.txt from scripts into the main libpng directory. + Various bugfixes and improvements to CMakeLists.txt (Philip Lowman) + +Version 1.4.0beta78 [August 31, 2009] + Converted all PNG_NO_* tests to PNG_*_SUPPORTED everywhere except pngconf.h + Eliminated PNG_NO_FREE_ME and PNG_FREE_ME_SUPPORTED macros. + Use png_malloc plus a loop instead of png_calloc() to initialize + row_pointers in png_read_png(). + +Version 1.4.0beta79 [September 1, 2009] + Eliminated PNG_GLOBAL_ARRAYS and PNG_LOCAL_ARRAYS; always use local arrays. + Eliminated PNG_CALLOC_SUPPORTED macro and always provide png_calloc(). + +Version 1.4.0beta80 [September 17, 2009] + Removed scripts/libpng.icc + Changed typecast of filler from png_byte to png_uint_16 in png_set_filler(). + (Dennis Gustafsson) + Fixed typo introduced in beta78 in pngtest.c ("#if def " should be "#ifdef ") + +Version 1.4.0beta81 [September 23, 2009] + Eliminated unused PNG_FLAG_FREE_* defines from pngpriv.h + Expanded TAB characters in pngrtran.c + Removed PNG_CONST from all "PNG_CONST PNG_CHNK" declarations to avoid + compiler complaints about doubly declaring things "const". + Changed all "#if [!]defined(X)" to "if[n]def X" where possible. + Eliminated unused png_ptr->row_buf_size + +Version 1.4.0beta82 [September 25, 2009] + Moved redundant IHDR checking into new png_check_IHDR() in png.c + and report all errors found in the IHDR data. + Eliminated useless call to png_check_cHRM() from pngset.c + +Version 1.4.0beta83 [September 25, 2009] + Revised png_check_IHDR() to eliminate bogus complaint about filter_type. + +Version 1.4.0beta84 [September 30, 2009] + Fixed some inconsistent indentation in pngconf.h + Revised png_check_IHDR() to add a test for width variable less than 32-bit. + +Version 1.4.0beta85 [October 1, 2009] + Revised png_check_IHDR() again, to check info_ptr members instead of + the contents of the returned parameters. + +Version 1.4.0beta86 [October 9, 2009] + Updated the "xcode" project (Alam Arias). + Eliminated a shadowed declaration of "pp" in png_handle_sPLT(). + +Version 1.4.0rc01 [October 19, 2009] + Trivial cosmetic changes. + +Version 1.4.0beta87 [October 30, 2009] + Moved version 1.4.0 back into beta. + +Version 1.4.0beta88 [October 30, 2009] + Revised libpng*.txt section about differences between 1.2.x and 1.4.0 + because most of the new features have now been ported back to 1.2.41 + +Version 1.4.0beta89 [November 1, 2009] + More bugfixes and improvements to CMakeLists.txt (Philip Lowman) + Removed a harmless extra png_set_invert_alpha() from pngwrite.c + Apply png_user_chunk_cache_max within png_decompress_chunk(). + Merged libpng-1.2.41.txt with libpng-1.4.0.txt where appropriate. + +Version 1.4.0beta90 [November 2, 2009] + Removed all remaining WIN32_WCE #ifdefs except those involving the + time.h "tm" structure + +Version 1.4.0beta91 [November 3, 2009] + Updated scripts/pngw32.def and projects/wince/png32ce.def + Copied projects/wince/png32ce.def to the scripts directory. + Added scripts/makefile.wce + Patched ltmain.sh for wince support. + Added PNG_CONVERT_tIME_SUPPORTED macro. + +Version 1.4.0beta92 [November 4, 2009] + Make inclusion of time.h in pngconf.h depend on PNG_CONVERT_tIME_SUPPORTED + Make #define PNG_CONVERT_tIME_SUPPORTED depend on PNG_WRITE_tIME_SUPPORTED + Revised libpng*.txt to describe differences from 1.2.40 to 1.4.0 (instead + of differences from 1.2.41 to 1.4.0) + +Version 1.4.0beta93 [November 7, 2009] + Added PNG_DEPSTRUCT, PNG_DEPRECATED, PNG_USE_RESULT, PNG_NORETURN, and + PNG_ALLOCATED macros to detect deprecated direct access to the + png_struct or info_struct members and other deprecated usage in + applications (John Bowler). + Updated scripts/makefile* to add "-DPNG_CONFIGURE_LIBPNG" to CFLAGS, + to prevent warnings about direct access to png structs by libpng + functions while building libpng. They need to be tested, especially + those using compilers other than gcc. + Updated projects/visualc6 and visualc71 with "/d PNG_CONFIGURE_LIBPNG". + They should work but still need to be updated to remove + references to pnggccrd.c or pngvcrd.c and ASM building. + Added README.txt to the beos, cbuilder5, netware, and xcode projects warning + that they need to be updated, to remove references to pnggccrd.c and + pngvcrd.c and to depend on pngpriv.h + Removed three direct references to read_info_ptr members in pngtest.c + that were detected by the new PNG_DEPSTRUCT macro. + Moved the png_debug macro definitions and the png_read_destroy(), + png_write_destroy() and png_far_to_near() prototypes from png.h + to pngpriv.h (John Bowler) + Moved the synopsis lines for png_read_destroy(), png_write_destroy() + png_debug(), png_debug1(), and png_debug2() from libpng.3 to libpngpf.3. + +Version 1.4.0beta94 [November 9, 2009] + Removed the obsolete, unused pnggccrd.c and pngvcrd.c files. + Updated CMakeLists.txt to add "-DPNG_CONFIGURE_LIBPNG" to the definitions. + Removed dependency of pngtest.o on pngpriv.h in the makefiles. + Only #define PNG_DEPSTRUCT, etc. in pngconf.h if not already defined. + +Version 1.4.0beta95 [November 10, 2009] + Changed png_check_sig() to !png_sig_cmp() in contrib programs. + Added -DPNG_CONFIGURE_LIBPNG to contrib/pngminm/*/makefile + Changed png_check_sig() to !png_sig_cmp() in contrib programs. + Corrected the png_get_IHDR() call in contrib/gregbook/readpng2.c + Changed pngminim/*/gather.sh to stop trying to remove pnggccrd.c and pngvcrd.c + Added dependency on pngpriv.h in contrib/pngminim/*/makefile + +Version 1.4.0beta96 [November 12, 2009] + Renamed scripts/makefile.wce to scripts/makefile.cegcc + Revised Makefile.am to use libpng.sys while building libpng.so + so that only PNG_EXPORT functions are exported. + Removed the deprecated png_check_sig() function/macro. + Removed recently removed function names from scripts/*.def + Revised pngtest.png to put chunks in the same order written by pngtest + (evidently the same change made in libpng-1.0beta54 was lost). + Added PNG_PRIVATE macro definition in pngconf.h for possible future use. + +Version 1.4.0beta97 [November 13, 2009] + Restored pngtest.png to the libpng-1.4.0beta7 version. + Removed projects/beos and netware.txt; no one seems to be supporting them. + Revised Makefile.in + +Version 1.4.0beta98 [November 13, 2009] + Added the "xcode" project to zip distributions, + Fixed a typo in scripts/pngwin.def introduced in beta97. + +Version 1.4.0beta99 [November 14, 2009] + Moved libpng-config.in and libpng.pc-configure.in out of the scripts + directory, to libpng-config.in and libpng-pc.in, respectively, and + modified Makefile.am and configure.ac accordingly. Now "configure" + needs nothing from the "scripts" directory. + Avoid redefining PNG_CONST in pngconf.h + +Version 1.4.0beta100 [November 14, 2009] + Removed ASM builds from projects/visualc6 and projects/visualc71 + Removed scripts/makefile.nommx and makefile.vcawin32 + Revised CMakeLists.txt to account for new location of libpng-config.in + and libpng-pc.in + Updated INSTALL to reflect removal and relocation of files. + +Version 1.4.0beta101 [November 14, 2009] + Restored the binary files (*.jpg, *.png, some project files) that were + accidentally deleted from the zip and 7z distributions when the xcode + project was added. + +Version 1.4.0beta102 [November 18, 2009] + Added libpng-config.in and libpng-pc.in to the zip and 7z distributions. + Fixed a typo in projects/visualc6/pngtest.dsp, introduced in beta100. + Moved descriptions of makefiles and other scripts out of INSTALL into + scripts/README.txt + Updated the copyright year in scripts/pngwin.rc from 2006 to 2009. + +Version 1.4.0beta103 [November 21, 2009] + Removed obsolete comments about ASM from projects/visualc71/README_zlib.txt + Align row_buf on 16-byte boundary in memory. + Restored the PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED guard around the call + to png_flush() after png_write_IEND(). See 1.4.0beta32, 1.4.0beta50 + changes above and 1.2.30, 1.2.30rc01 and rc03 in 1.2.41 CHANGES. Someone + needs this feature. + Make the 'png_jmpbuf' macro expand to a call that records the correct + longjmp function as well as returning a pointer to the setjmp + jmp_buf buffer, and marked direct access to jmpbuf 'deprecated'. + (John Bowler) + +Version 1.4.0beta104 [November 22, 2009] + Removed png_longjmp_ptr from scripts/*.def and libpng.3 + Rebuilt configure scripts with autoconf-2.65 + +Version 1.4.0beta105 [November 25, 2009] + Use fast integer PNG_DIVIDE_BY_255() or PNG_DIVIDE_BY_65535() + to accomplish alpha premultiplication when + PNG_READ_COMPOSITE_NODIV_SUPPORTED is defined. + Changed "/255" to "/255.0" in background calculations to make it clear + that the 255 is used as a double. + +Version 1.4.0beta106 [November 27, 2009] + Removed premultiplied alpha feature. + +Version 1.4.0beta107 [December 4, 2009] + Updated README + Added "#define PNG_NO_PEDANTIC_WARNINGS" in the libpng source files. + Removed "-DPNG_CONFIGURE_LIBPNG" from the makefiles and projects. + Revised scripts/makefile.netbsd, makefile.openbsd, and makefile.sco + to put png.h and pngconf.h in $prefix/include, like the other scripts, + instead of in $prefix/include/libpng. Also revised makefile.sco + to put them in $prefix/include/libpng15 instead of in + $prefix/include/libpng/libpng15. + +Version 1.4.0beta108 [December 11, 2009] + Removed leftover "-DPNG_CONFIGURE_LIBPNG" from contrib/pngminim/*/makefile + Relocated png_do_chop() to its original position in pngrtran.c; the + change in version 1.2.41beta08 caused transparency to be handled wrong + in some 16-bit datastreams (Yusaku Sugai). + +Version 1.4.0beta109 [December 13, 2009] + Added "bit_depth" parameter to the private png_build_gamma_table() function. + Pass bit_depth=8 to png_build_gamma_table() when bit_depth is 16 but the + PNG_16_TO_8 transform has been set, to avoid unnecessary build of 16-bit + tables. + +Version 1.4.0rc02 [December 20, 2009] + Declared png_cleanup_needed "volatile" in pngread.c and pngwrite.c + +Version 1.4.0rc03 [December 22, 2009] + Renamed libpng-pc.in back to libpng.pc.in and revised CMakeLists.txt + (revising the change in 1.4.0beta99) + +Version 1.4.0rc04 [December 25, 2009] + Swapped PNG_UNKNOWN_CHUNKS_SUPPORTED and PNG_HANDLE_AS_UNKNOWN_SUPPORTED + in pngset.c to be consistent with other changes in version 1.2.38. + +Version 1.4.0rc05 [December 25, 2009] + Changed "libpng-pc.in" to "libpng.pc.in" in configure.ac, configure, and + Makefile.in to be consistent with changes in libpng-1.4.0rc03 + +Version 1.4.0rc06 [December 29, 2009] + Reverted the gamma_table changes from libpng-1.4.0beta109. + Fixed some indentation errors. + +Version 1.4.0rc07 [January 1, 2010] + Revised libpng*.txt and libpng.3 about 1.2.x->1.4.x differences. + Use png_calloc() instead of png_malloc(); png_memset() in pngrutil.c + Update copyright year to 2010. + +Version 1.4.0rc08 [January 2, 2010] + Avoid deprecated references to png_ptr-io_ptr and png_ptr->error_ptr + in pngtest.c + +Version 1.4.0 [January 3, 2010] + No changes. + +Version 1.4.1beta01 [January 8, 2010] + Updated CMakeLists.txt for consistent indentation and to avoid an + unclosed if-statement warning (Philip Lowman). + Revised Makefile.am and Makefile.in to remove references to Y2KINFO, + KNOWNBUG, and libpng.la (Robert Schwebel). + Revised the makefiles to install the same files and symbolic + links as configure, except for libpng.la and libpng14.la. + Make png_set|get_compression_buffer_size() available even when + PNG_WRITE_SUPPORTED is not enabled. + Revised Makefile.am and Makefile.in to simplify their maintenance. + Revised scripts/makefile.linux to install a link to libpng14.so.14.1 + +Version 1.4.1beta02 [January 9, 2010] + Revised the rest of the makefiles to install a link to libpng14.so.14.1 + +Version 1.4.1beta03 [January 10, 2010] + Removed png_set_premultiply_alpha() from scripts/*.def + +Version 1.4.1rc01 [January 16, 2010] + No changes. + +Version 1.4.1beta04 [January 23, 2010] + Revised png_decompress_chunk() to improve speed and memory usage when + decoding large chunks. + Added png_set|get_chunk_malloc_max() functions. + +Version 1.4.1beta05 [January 26, 2010] + Relocated "int k" declaration in pngtest.c to minimize its scope. + +Version 1.4.1beta06 [January 28, 2010] + Revised png_decompress_chunk() to use a two-pass method suggested by + John Bowler. + +Version 1.4.1beta07 [February 6, 2010] + Folded some long lines in the source files. + Added defineable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX, + and a PNG_USER_LIMITS_SUPPORTED flag. + Eliminated use of png_ptr->irowbytes and reused the slot in png_ptr as + png_ptr->png_user_chunk_malloc_max. + Revised png_push_save_buffer() to do fewer but larger png_malloc() calls. + +Version 1.4.1beta08 [February 6, 2010] + Minor cleanup and updating of dates and copyright year. + +Version 1.5.0beta01 [February 7, 2010] + Moved declaration of png_struct into private pngstruct.h and png_info + into pnginfo.h + +Version 1.4.1beta09 and 1.5.0beta02 [February 7, 2010] + Reverted to original png_push_save_buffer() code. + +Version 1.4.1beta10 and 1.5.0beta03 [February 8, 2010] + Return allocated "old_buffer" in png_push_save_buffer() before + calling png_error(), to avoid a potential memory leak. + Updated configure script to use SO number 15. + +Version 1.5.0beta04 [February 9, 2010] + Removed malformed "incomplete struct declaration" of png_info from png.h + +Version 1.5.0beta05 [February 12, 2010] + Removed PNG_DEPSTRUCT markup in pngstruct.h and pnginfo.h, and undid the + linewrapping that it entailed. + Revised comments in pngstruct.h and pnginfo.h and added pointers to + the libpng license. + Changed PNG_INTERNAL to PNG_EXPOSE_INTERNAL_STRUCTURES + Removed the cbuilder5 project, which has not been updated to 1.4.0. + +Version 1.4.1beta12 and 1.5.0beta06 [February 14, 2010] + Fixed type declaration of png_get_chunk_malloc_max() in pngget.c (Daisuke + Nishikawa) + +Version 1.5.0beta07 [omitted] + +Version 1.5.0beta08 [February 19, 2010] + Changed #ifdef PNG_NO_STDIO_SUPPORTED to #ifdef PNG_NO_CONSOLE_IO_SUPPORTED + wherever png_snprintf() is used to construct error and warning messages. + Noted in scripts/makefile.mingw that it expects to be run under MSYS. + Removed obsolete unused MMX-querying support from contrib/gregbook + Added exported png_longjmp() function. + Removed the AIX redefinition of jmpbuf in png.h + Added -D_ALLSOURCE in configure.ac, makefile.aix, and CMakeLists.txt + when building on AIX. + +Version 1.5.0beta09 [February 19, 2010] + Removed -D_ALLSOURCE from configure.ac, makefile.aix, and CMakeLists.txt. + Changed the name of png_ptr->jmpbuf to png_ptr->png_jmpbuf in pngstruct.h + +Version 1.5.0beta10 [February 25, 2010] + Removed unused gzio.c from contrib/pngminim gather and makefile scripts + Removed replacement error handlers from contrib/gregbook. Because of + the new png_longjmp() function they are no longer needed. + +Version 1.5.0beta11 [March 6, 2010] + Removed checking for already-included setjmp.h from pngconf.h + Fixed inconsistent indentations and made numerous cosmetic changes. + Revised the "SEE ALSO" style of libpng.3, libpngpf.3, and png.5 + +Version 1.5.0beta12 [March 9, 2010] + Moved "#include png.h" inside pngpriv.h and removed "#include png.h" from + the source files, along with "#define PNG_EXPOSE_INTERNAL_STRUCTURES" + and "#define PNG_NO_PEDANTIC_WARNINGS" (John Bowler). + Created new pngdebug.h and moved debug definitions there. + +Version 1.5.0beta13 [March 10, 2010] + Protect pngstruct.h, pnginfo.h, and pngdebug.h from being included twice. + Revise the "#ifdef" blocks in png_inflate() so it will compile when neither + PNG_USER_CHUNK_MALLOC_MAX nor PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED + is defined. + Removed unused png_measure_compressed_chunk() from pngpriv.h and libpngpf.3 + Moved the 'config.h' support from pngconf.h to pngpriv.h + Removed PNGAPI from the png_longjmp_ptr typedef. + Eliminated dependence of pngtest.c on the private pngdebug.h file. + Make all png_debug macros into *unterminated* statements or + expressions (i.e. a trailing ';' must always be added) and correct + the format statements in various png_debug messages. + +Version 1.5.0beta14 [March 14, 2010] + Removed direct access to png_ptr->io_ptr from the Windows code in pngtest.c + Revised Makefile.am to account for recent additions and replacements. + Corrected CE and OS/2 DEF files (scripts/png*def) for symbols removed and + added ordinal numbers to the Windows DEF file and corrected the duplicated + ordinal numbers on CE symbols that are commented out. + Added back in export symbols that can be present in the Windows build but + are disabled by default. + PNG_EXPORT changed to include an 'ordinal' field for DEF file generation. + PNG_CALLBACK added to make callback definitions uniform. PNGAPI split + into PNGCAPI (base C form), PNGAPI (exports) and PNGCBAPI (callbacks), + and appropriate changes made to all files. Cygwin builds re-hinged to + allow procedure call standard changes and to remove the need for the DEF + file (fixes build on Cygwin). + Enabled 'attribute' warnings that are relevant to library APIs and callbacks. + Changed rules for generation of the various symbol files and added a new + rule for a DEF file (which is also added to the distribution). + Updated the symbol file generation to stop it adding spurious spaces + to EOL (coming from preprocessor macro expansion). Added a facility + to join tokens in the output and rewrite *.dfn to use this. + Eliminated scripts/*.def in favor of libpng.def; updated projects/visualc71 + and removed scripts/makefile.cygwin. + Made PNG_BUILD_DLL safe: it can be set whenever a DLL is being built. + Removed the include of sys/types.h - apparently unnecessary now on the + platforms on which it happened (all but Mac OS and RISC OS). + Moved the Mac OS test into pngpriv.h (the only place it is used.) + +Version 1.5.0beta15 [March 17, 2010] + Added symbols.chk target to Makefile.am to validate the symbols in png.h + against the new DEF file scripts/symbols.def. + Changed the default DEF file back to pngwin.def. + Removed makefile.mingw. + Eliminated PNG_NO_EXTERN and PNG_ALL_EXTERN + +Version 1.5.0beta16 [April 1, 2010] + Make png_text_struct independent of PNG_iTXt_SUPPORTED, so that + fields are initialized in all configurations. The READ/WRITE + macros (PNG_(READ|WRITE)_iTXt_SUPPORTED) still function as + before to disable code to actually read or write iTXt chunks + and iTXt_SUPPORTED can be used to detect presence of either + read or write support (but it is probably better to check for + the one actually required - read or write.) + Combined multiple png_warning() calls for a single error. + Restored the macro definition of png_check_sig(). + +Version 1.5.0beta17 [April 17, 2010] + Added some "(long)" typecasts to printf calls in png_handle_cHRM(). + Documented the fact that png_set_dither() was disabled since libpng-1.4.0. + Reenabled png_set_dither() but renamed it to png_set_quantize() to reflect + more accurately what it actually does. At the same time, renamed + the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros to + PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS. + Added some "(long)" typecasts to printf calls in png_handle_cHRM(). + Freeze build-time only configuration in the build. + In all prior versions of libpng most configuration options + controlled by compiler #defines had to be repeated by the + application code that used libpng. This patch changes this + so that compilation options that can only be changed at build + time are frozen in the build. Options that are compiler + dependent (and those that are system dependent) are evaluated + each time - pngconf.h holds these. Options that can be changed + per-file in the application are in png.h. Frozen options are + in the new installed header file pnglibconf.h (John Bowler) + Removed the xcode project because it has not been updated to work + with libpng-1.5.0. + Removed the ability to include optional pngusr.h + +Version 1.5.0beta18 [April 17, 2010] + Restored the ability to include optional pngusr.h + Moved replacements for png_error() and png_warning() from the + contrib/pngminim project to pngerror.c, for use when warnings or + errors are disabled via PNG_NO_WARN or PNG_NO_ERROR_TEXT, to avoid + storing unneeded error/warning text. + Updated contrib/pngminim project to work with the new pnglibconf.h + Added some PNG_NO_* defines to contrib/pngminim/*/pngusr.h to save space. + +Version 1.5.0beta19 [April 24, 2010] + Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED. This allows the functions + to read and write ints to be disabled independently of PNG_USE_READ_MACROS, + which allows libpng to be built with the functions even though the default + is to use the macros - this allows applications to choose at app build + time whether or not to use macros (previously impossible because the + functions weren't in the default build.) + Changed Windows calling convention back to __cdecl for API functions. + For Windows/x86 platforms only: + __stdcall is no longer needed for Visual Basic, so libpng-1.5.0 uses + __cdecl throughout (both API functions and callbacks) on Windows/x86 + platforms. + Replaced visualc6 and visualc71 projects with new vstudio project + Relaxed the overly-restrictive permissions of some files. + +Version 1.5.0beta20 [April 24, 2010] + Relaxed more overly-restrictive permissions of some files. + +Version 1.5.0beta21 [April 27, 2010] + Removed some unwanted binary bytes and changed CRLF to NEWLINE in the new + vstudio project files, and some trivial editing of some files in the + scripts directory. + Set PNG_NO_READ_BGR, PNG_NO_IO_STATE, and PNG_NO_TIME_RFC1123 in + contrib/pngminim/decoder/pngusr.h to make a smaller decoder application. + +Version 1.5.0beta22 [April 28, 2010] + Fixed dependencies of GET_INT_32 - it does not require READ_INT_FUNCTIONS + because it has a macro equivalent. + Improved the options.awk script; added an "everything off" option. + Revised contrib/pngminim to use the "everything off" option in pngusr.dfa. + +Version 1.5.0beta23 [April 29, 2010] + Corrected PNG_REMOVED macro to take five arguments. + The macro was documented with two arguments (name,ordinal), however + the symbol checking .dfn files assumed five arguments. The five + argument form seems more useful so it is changed to that. + Corrected PNG_UNKNOWN_CHUNKS_SUPPORTED to PNG_HANDLE_AS_UNKNOWN_SUPPORTED + in gregbook/readpng2.c + Corrected protection of png_get_user_transform_ptr. The API declaration in + png.h is removed if both READ and WRITE USER_TRANSFORM are turned off + but was left defined in pngtrans.c + Added logunsupported=1 to cause pnglibconf.h to document disabled options. + This makes the installed pnglibconf.h more readable but causes no + other change. The intention is that users of libpng will find it + easier to understand if an API they need is missing. + Include png_reset_zstream() in png.c only when PNG_READ_SUPPORTED is defined. + Removed dummy_inflate.c from contrib/pngminim/encoder + Removed contrib/pngminim/*/gather.sh; gathering is now done in the makefile. + +Version 1.5.0beta24 [May 7, 2010] + Use bitwise "&" instead of arithmetic mod in pngrutil.c calculation of the + offset of the png_ptr->rowbuf pointer into png_ptr->big_row_buf. + Added more blank lines for readability. + +Version 1.5.0beta25 [June 18, 2010] + In pngpread.c: png_push_have_row() add check for new_row > height + Removed the now-redundant check for out-of-bounds new_row from example.c + +Version 1.5.0beta26 [June 18, 2010] + In pngpread.c: png_push_process_row() add check for too many rows. + +Version 1.5.0beta27 [June 18, 2010] + Removed the check added in beta25 as it is now redundant. + +Version 1.5.0beta28 [June 20, 2010] + Rewrote png_process_IDAT_data to consistently treat extra data as warnings + and handle end conditions more cleanly. + Removed the new (beta26) check in png_push_process_row(). + +Version 1.5.0beta29 [June 21, 2010] + Revised scripts/options.awk to work on Sunos (but still doesn't work) + Added comment to options.awk and contrib/pngminim/*/makefile to try nawk. + +Version 1.5.0beta30 [June 22, 2010] + Stop memory leak when reading a malformed sCAL chunk. + +Version 1.5.0beta31 [June 26, 2010] + Revised pngpread.c patch of beta28 to avoid an endless loop. + Removed some trailing blanks. + +Version 1.5.0beta32 [June 26, 2010] + Removed leftover scripts/options.patch and scripts/options.rej + +Version 1.5.0beta33 [July 6, 3010] + Made FIXED and FLOATING options consistent in the APIs they enable and + disable. Corrected scripts/options.awk to handle both command line + options and options specified in the .dfa files. + Changed char *msg to PNG_CONST char *msg in pngrutil.c + Make png_set_sRGB_gAMA_and_cHRM set values using either the fixed or + floating point APIs, but not both. + Reversed patch to remove error handler when the jmp_buf is stored in the + main program structure, not the png_struct. + The error handler is needed because the default handler in libpng will + always use the jmp_buf in the library control structure; this is never + set. The gregbook code is a useful example because, even though it + uses setjmp/longjmp, it shows how error handling can be implemented + using control mechanisms not directly supported by libpng. The + technique will work correctly with mechanisms such as Microsoft + Structure Exceptions or C++ exceptions (compiler willing - note that gcc + does not by default support interworking of C and C++ error handling.) + Reverted changes to call png_longjmp in contrib/gregbook where it is not + appropriate. If mainprog->jmpbuf is used by setjmp, then png_longjmp + cannot be used. + Changed "extern PNG_EXPORT" to "PNG_EXPORT" in png.h (Jan Nijtmans) + Changed "extern" to "PNG_EXTERN" in pngpriv.h (except for the 'extern "C" {') + +Version 1.5.0beta34 [July 12, 2010] + Put #ifndef PNG_EXTERN, #endif around the define PNG_EXTERN in pngpriv.h + +Version 1.5.0beta35 [July 24, 2010] + Removed some newly-added TAB characters. + Added -DNO_PNG_SNPRINTF to CFLAGS in scripts/makefile.dj2 + Moved the definition of png_snprintf() outside of the enclosing + #ifdef blocks in pngconf.h + +Version 1.5.0beta36 [July 29, 2010] + Patches by John Bowler: + Fixed point APIs are now supported throughout (no missing APIs). + Internal fixed point arithmetic support exists for all internal floating + point operations. + sCAL validates the floating point strings it is passed. + Safe, albeit rudimentary, Watcom support is provided by PNG_API_RULE==2 + Two new APIs exist to get the number of passes without turning on the + PNG_INTERLACE transform and to get the number of rows in the current + pass. + A new test program, pngvalid.c, validates the gamma code. + Errors in the 16-bit gamma correction (overflows) have been corrected. + cHRM chunk testing is done consistently (previously the floating point + API bypassed it, because the test really didn't work on FP, now the test + is performed on the actual values to be stored in the PNG file so it + works in the FP case too.) + Most floating point APIs now simply call the fixed point APIs after + converting the values to the fixed point form used in the PNG file. + The standard headers no longer include zlib.h, which is currently only + required for pngstruct.h and can therefore be internal. + Revised png_get_int_32 to undo the PNG two's complement representation of + negative numbers. + +Version 1.5.0beta37 [July 30, 2010] + Added a typecast in png_get_int_32() in png.h and pngrutil.h to avoid + a compiler warning. + Replaced oFFs 0,0 with oFFs -10,20 in pngtest.png + +Version 1.5.0beta38 [July 31, 2010] + Implemented remaining "_fixed" functions. + Corrected a number of recently introduced warnings mostly resulting from + safe but uncast assignments to shorter integers. Also added a zlib + VStudio release library project because the latest zlib Official Windows + build does not include such a thing. + Revised png_get_int_16() to be similar to png_get_int_32(). + Restored projects/visualc71. + +Version 1.5.0beta39 [August 2, 2010] + VisualC/GCC warning fixes, VisualC build fixes + The changes include support for function attributes in VC in addition to + those already present in GCC - necessary because without these some + warnings are unavoidable. Fixes include signed/unsigned fixes in + pngvalid and checks with gcc -Wall -Wextra -Wunused. + VC requires function attributes on function definitions as well as + declarations, PNG_FUNCTION has been added to enable this and the + relevant function definitions changed. + +Version 1.5.0beta40 [August 6, 2010] + Correct use of _WINDOWS_ in pngconf.h + Removed png_mem_ #defines; they are no longer used. + Added the sRGB chunk to pngtest.png + +Version 1.5.0beta41 [August 11, 2010] + Added the cHRM chunk to pngtest.png + Don't try to use version-script with cygwin/mingw. + Revised contrib/gregbook to work under cygwin/mingw. + +Version 1.5.0beta42 [August 18, 2010] + Add .dll.a to the list of extensions to be symlinked by Makefile.am (Yaakov) + Made all API functions that have const arguments and constant string + literal pointers declare them (John Bowler). + +Version 1.5.0beta43 [August 20, 2010] + Removed spurious tabs, shorten long lines (no source change) + Also added scripts/chkfmt to validate the format of all the files that can + reasonably be validated (it is suggested to run "make distclean" before + checking, because some machine generated files have long lines.) + Reformatted the CHANGES file to be more consistent throughout. + Made changes to address various issues identified by GCC, mostly + signed/unsigned and shortening problems on assignment but also a few + difficult to optimize (for GCC) loops. + Fixed non-GCC fixed point builds. In png.c a declaration was misplaced + in an earlier update. Fixed to declare the auto variables at the head. + Use cexcept.h in pngvalid.c. + +Version 1.5.0beta44 [August 24, 2010] + Updated CMakeLists.txt to use CMAKE_INSTALL_LIBDIR variable; useful for + installing libpng in /usr/lib64 (Funda Wang). + Revised CMakeLists.txt to put the man pages in share/man/man* not man/man* + Revised CMakeLists.txt to make symlinks instead of copies when installing. + Changed PNG_LIB_NAME from pngNN to libpngNN in CMakeLists.txt (Philip Lowman) + Implemented memory checks within pngvalid + Reformatted/rearranged pngvalid.c to assist use of progressive reader. + Check interlaced images in pngvalid + Clarified pngusr.h comments in pnglibconf.dfa + Simplified the pngvalid error-handling code now that cexcept.h is in place. + Implemented progressive reader in pngvalid.c for standard tests + Implemented progressive read in pngvalid.c gamma tests + Turn on progressive reader in pngvalid.c by default and tidy code. + +Version 1.5.0beta45 [August 26, 2010] + Added an explicit make step to projects/vstudio for pnglibconf.h + Also corrected zlib.vcxproj into which Visual Studio had introduced + what it calls an "authoring error". The change to make pnglibconf.h + simply copies the file; in the future it may actually generate the + file from scripts/pnglibconf.dfa as the other build systems do. + Changed pngvalid to work when floating point APIs are disabled + Renamed the prebuilt scripts/pnglibconf.h to scripts/pnglibconf.h.prebuilt + Supply default values for PNG_USER_PRIVATEBUILD and PNG_USER_DLLFNAME_POSTFIX + in pngpriv.h in case the user neglected to define them in their pngusr.h + +Version 1.5.0beta46 [August 28, 2010] + Added new private header files to libpng_sources in CMakeLists.txt + Added PNG_READ_16BIT, PNG_WRITE_16BIT, and PNG_16BIT options. + Added reference to scripts/pnglibconf.h.prebuilt in the visualc71 project. + +Version 1.5.0beta47 [September 11, 2010] + Fixed a number of problems with 64-bit compilation reported by Visual + Studio 2010 (John Bowler). + +Version 1.5.0beta48 [October 4, 2010] + Updated CMakeLists.txt (Philip Lowman). + Revised autogen.sh to recognize and use $AUTOCONF, $AUTOMAKE, $AUTOHEADER, + $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE + Fixed problem with symbols creation in Makefile.am which was assuming that + all versions of ccp write to standard output by default (Martin Banky). The + bug was introduced in libpng-1.2.9beta5. + Removed unused mkinstalldirs. + +Version 1.5.0beta49 [October 8, 2010] + Undid Makefile.am revision of 1.5.0beta48. + +Version 1.5.0beta50 [October 14, 2010] + Revised Makefile.in to account for mkinstalldirs being removed. + Added some "(unsigned long)" typecasts in printf statements in pngvalid.c. + Suppressed a compiler warning in png_handle_sPLT(). + Check for out-of-range text compression mode in png_set_text(). + +Version 1.5.0beta51 [October 15, 2010] + Changed embedded dates to "(PENDING RELEASE) in beta releases (and future + rc releases) to minimize the difference between releases. + +Version 1.5.0beta52 [October 16, 2010] + Restored some of the embedded dates (in png.h, png.c, documentation, etc.) + +Version 1.5.0beta53 [October 18, 2010] + Updated INSTALL to mention using "make maintainer-clean" and to remove + obsolete statement about a custom ltmain.sh + Disabled "color-tests" by default in Makefile.am so it will work with + automake versions earlier than 1.11.1 + Use document name "libpng-manual.txt" instead of "libpng-<version>.txt" + to simplify version differences. + Removed obsolete remarks about setjmp handling from INSTALL. + Revised and renamed the typedef in png.h and png.c that was designed + to catch library and header mismatch. + +Version 1.5.0beta54 [November 10, 2010] + Require 48 bytes, not 64 bytes, for big_row_buf in overflow checks. + Used a consistent structure for the pngget.c functions. + +Version 1.5.0beta55 [November 21, 2010] + Revised png_get_uint_32, png_get_int_32, png_get_uint_16 (Cosmin) + Moved reading of file signature into png_read_sig (Cosmin) + Fixed atomicity of chunk header serialization (Cosmin) + Added test for io_state in pngtest.c (Cosmin) + Added "#!/bin/sh" at the top of contrib/pngminim/*/gather.sh scripts. + Changes to remove gcc warnings (John Bowler) + Certain optional gcc warning flags resulted in warnings in libpng code. + With these changes only -Wconversion and -Wcast-qual cannot be turned on. + Changes are trivial rearrangements of code. -Wconversion is not possible + for pngrutil.c (because of the widespread use of += et al on variables + smaller than (int) or (unsigned int)) and -Wcast-qual is not possible + with pngwio.c and pngwutil.c because the 'write' callback and zlib + compression both fail to declare their input buffers with 'const'. + +Version 1.5.0beta56 [December 7, 2010] + Added the private PNG_UNUSED() macro definition in pngpriv.h. + Added some commentary about PNG_EXPORT in png.h and pngconf.h + Revised PNG_EXPORT() macro and added PNG_EXPORTA() macro, with the + objective of simplifying and improving the cosmetic appearance of png.h. + Fixed some incorrect "=" macro names in pnglibconf.dfa + Included documentation of changes in 1.5.0 from 1.4.x in libpng-manual.txt + +Version 1.5.0beta57 [December 9, 2010] + Documented the pngvalid gamma error summary with additional comments and + print statements. + Improved missing symbol handling in checksym.awk; symbols missing in both + the old and new files can now be optionally ignored, treated as errors + or warnings. + Removed references to pngvcrd.c and pnggccrd.c from the vstudio project. + Updated "libpng14" to "libpng15" in the visualc71 project. + Enabled the strip16 tests in pngvalid.` + Don't display test results (except PASS/FAIL) when running "make test". + Instead put them in pngtest-log.txt + Added "--with-zprefix=<string>" to configure.ac + Updated the prebuilt configuration files to autoconf version 2.68 + +Version 1.5.0beta58 [December 19, 2010] + Fixed interlace image handling and add test cases (John Bowler) + Fixed the clean rule in Makefile.am to remove pngtest-log.txt + Made minor changes to work around warnings in gcc 3.4 + +Version 1.5.0rc01 [December 27, 2010] + No changes. + +Version 1.5.0rc02 [December 27, 2010] + Eliminated references to the scripts/*.def files in project/visualc71. + +Version 1.5.0rc03 [December 28, 2010] + Eliminated scripts/*.def and revised Makefile.am accordingly + +Version 1.5.0rc04 [December 29, 2010] + Fixed bug in background transformation handling in pngrtran.c (it was + looking for the flag in png_ptr->transformations instead of in + png_ptr->flags) (David Raymond). + +Version 1.5.0rc05 [December 31, 2010] + Fixed typo in a comment in CMakeLists.txt (libpng14 => libpng15) (Cosmin) + +Version 1.5.0rc06 [January 4, 2011] + Changed the new configure option "zprefix=string" to "zlib-prefix=string" + +Version 1.5.0rc07 [January 4, 2011] + Updated copyright year. + +Version 1.5.0 [January 6, 2011] + No changes. + +version 1.5.1beta01 [January 8, 2011] + Added description of png_set_crc_action() to the manual. + Added a note in the manual that the type of the iCCP profile was changed + from png_charpp to png_bytepp in png_get_iCCP(). This change happened + in version 1.5.0beta36 but is not noted in the CHANGES. Similarly, + it was changed from png_charpp to png_const_bytepp in png_set_iCCP(). + Ensure that png_rgb_to_gray ignores palette mapped images, if libpng + internally happens to call it with one, and fixed a failure to handle + palette mapped images correctly. This fixes CVE-2690. + +Version 1.5.1beta02 [January 14, 2011] + Fixed a bug in handling of interlaced images (bero at arklinux.org). + Updated CMakeLists.txt (Clifford Yapp) + +Version 1.5.1beta03 [January 14, 2011] + Fixed typecasting of some png_debug() statements (Cosmin) + +Version 1.5.1beta04 [January 16, 2011] + Updated documentation of png_set|get_tRNS() (Thomas Klausner). + Mentioned in the documentation that applications must #include "zlib.h" + if they need access to anything in zlib.h, and that a number of + macros such as png_memset() are no longer accessible by applications. + Corrected pngvalid gamma test "sample" function to access all of the color + samples of each pixel, instead of sampling the red channel three times. + Prefixed variable names index, div, exp, gamma with "png_" to avoid "shadow" + warnings, and (mistakenly) changed png_exp() to exp(). + +Version 1.5.1beta05 [January 16, 2011] + Changed variable names png_index, png_div, png_exp, and png_gamma to + char_index, divisor, exp_b10, and gamma_val, respectively, and + changed exp() back to png_exp(). + +Version 1.5.1beta06 [January 20, 2011] + Prevent png_push_crc_skip() from hanging while reading an unknown chunk + or an over-large compressed zTXt chunk with the progressive reader. + Eliminated more GCC "shadow" warnings. + Revised png_fixed() in png.c to avoid compiler warning about reaching the + end without returning anything. + +Version 1.5.1beta07 [January 22, 2011] + In the manual, describe the png_get_IHDR() arguments in the correct order. + Added const_png_structp and const_png_infop types, and used them in + prototypes for most png_get_*() functions. + +Version 1.5.1beta08 [January 23, 2011] + Added png_get_io_chunk_type() and deprecated png_get_io_chunk_name() + Added synopses for the IO_STATE functions and other missing synopses + to the manual. Removed the synopses from libpngpf.3 because they + were out of date and no longer useful. Better information can be + obtained by reading the prototypes and comments in pngpriv.h + Attempted to fix cpp on Solaris with S. Studio 12 cc, fix build + Added a make macro DFNCPP that is a CPP that will accept the tokens in + a .dfn file and adds configure stuff to test for such a CPP. ./configure + should fail if one is not available. + Corrected const_png_ in png.h to png_const_ to avoid polluting the namespace. + Added png_get_current_row_number and png_get_current_pass_number for the + benefit of the user transform callback. + Added png_process_data_pause and png_process_data_skip for the benefit of + progressive readers that need to stop data processing or want to optimize + skipping of unread data (e.g., if the reader marks a chunk to be skipped.) + +Version 1.5.1beta09 [January 24, 2011] + Enhanced pngvalid, corrected an error in gray_to_rgb, corrected doc error. + pngvalid contains tests of transforms, which tests are currently disabled + because they are incompletely tested. gray_to_rgb was failing to expand + the bit depth for smaller bit depth images; this seems to be a long + standing error and resulted, apparently, in invalid output + (CVE-2011-0408, CERT VU#643140). The documentation did not accurately + describe what libpng really does when converting RGB to gray. + +Version 1.5.1beta10 [January 27, 2010] + Fixed incorrect examples of callback prototypes in the manual, that were + introduced in libpng-1.0.0. + In addition the order of the png_get_uint macros with respect to the + relevant function definitions has been reversed. This helps the + preprocessing of the symbol files be more robust. Furthermore, the + symbol file preprocessing now uses -DPNG_NO_USE_READ_MACROS even when + the library may actually be built with PNG_USE_READ_MACROS; this stops + the read macros interfering with the symbol file format. + Made the manual, synopses, and function prototypes use the function + argument names file_gamma, int_file_gamma, and srgb_intent consistently. + +Version 1.5.1beta11 [January 28, 2011] + Changed PNG_UNUSED from "param=param;" to "{if(param){}}". + Corrected local variable type in new API png_process_data_skip() + The type was self-evidently incorrect but only causes problems on 64-bit + architectures. + Added transform tests to pngvalid and simplified the arguments. + +Version 1.5.1rc01 [January 29, 2011] + No changes. + +Version 1.5.1rc02 [January 31, 2011] + Added a request in the manual that applications do not use "png_" or + "PNG_" to begin any of their own symbols. + Changed PNG_UNUSED to "(void)param;" and updated the commentary in pngpriv.h + +Version 1.5.1 [February 3, 2011] + No changes. + +Version 1.5.2beta01 [February 13, 2011] + More -Wshadow fixes for older gcc compilers. Older gcc versions apparently + check formal parameters names in function declarations (as well as + definitions) to see if they match a name in the global namespace. + Revised PNG_EXPORTA macro to not use an empty parameter, to accommodate the + old VisualC++ preprocessor. + Turned on interlace handling in png_read_png(). + Fixed gcc pedantic warnings. + Handle longjmp in Cygwin. + Fixed png_get_current_row_number() in the interlaced case. + Cleaned up ALPHA flags and transformations. + Implemented expansion to 16 bits. + +Version 1.5.2beta02 [February 19, 2011] + Fixed mistake in the descriptions of user read_transform and write_transform + function prototypes in the manual. The row_info struct is png_row_infop. + Reverted png_get_current_row_number() to previous (1.5.2beta01) behavior. + Corrected png_get_current_row_number documentation + Fixed the read/write row callback documentation. + This documents the current behavior, where the callback is called after + every row with information pertaining to the next row. + +Version 1.5.2beta03 [March 3, 2011] + Fixed scripts/makefile.vcwin32 + Updated contrib/pngsuite/README to add the word "modify". + Define PNG_ALLOCATED to blank when _MSC_VER<1300. + +Version 1.5.2rc01 [March 19, 2011] + Define remaining attributes to blank when MSC_VER<1300. + ifdef out mask arrays in pngread.c when interlacing is not supported. + +Version 1.5.2rc02 [March 22, 2011] + Added a hint to try CPP=/bin/cpp if "cpp -E" fails in scripts/pnglibconf.mak + and in contrib/pngminim/*/makefile, eg., on SunOS 5.10, and removed "strip" + from the makefiles. + Fixed a bug (present since libpng-1.0.7) that makes png_handle_sPLT() fail + to compile when PNG_NO_POINTER_INDEXING is defined (Chubanov Kirill) + +Version 1.5.2rc03 [March 24, 2011] + Don't include standard header files in png.h while building the symbol table, + to avoid cpp failure on SunOS (introduced PNG_BUILDING_SYMBOL_TABLE macro). + +Version 1.5.2 [March 31, 2011] + No changes. + +Version 1.5.3beta01 [April 1, 2011] + Re-initialize the zlib compressor before compressing non-IDAT chunks. + Added API functions (png_set_text_compression_level() and four others) to + set parameters for zlib compression of non-IDAT chunks. + +Version 1.5.3beta02 [April 3, 2011] + Updated scripts/symbols.def with new API functions. + Only compile the new zlib re-initializing code when text or iCCP is + supported, using PNG_WRITE_COMPRESSED_TEXT_SUPPORTED macro. + Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03). + Optimize the zlib CMF byte in non-IDAT compressed chunks + +Version 1.5.3beta03 [April 16, 2011] + Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have + snprintf, and the "__STRICT_ANSI__" detects that condition more reliably + than __STDC__ (John Bowler). + Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells + the compiler that a user supplied callback (the error handler) does not + return, yet there is no guarantee in practice that the application code + will correctly implement the error handler because the compiler only + issues a warning if there is a mistake (John Bowler). + Removed the no-longer-used PNG_DEPSTRUCT macro. + Updated the zlib version to 1.2.5 in the VStudio project. + Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in + pngwutil.c (John Bowler). + Fixed bug with stripping the filler or alpha channel when writing, that + was introduced in libpng-1.5.2beta01 (bug report by Andrew Church). + +Version 1.5.3beta04 [April 27, 2011] + Updated pngtest.png with the new zlib CMF optimization. + Cleaned up conditional compilation code and of background/gamma handling + Internal changes only except a new option to avoid compiling the + png_build_grayscale_palette API (which is not used at all internally.) + The main change is to move the transform tests (READ_TRANSFORMS, + WRITE_TRANSFORMS) up one level to the caller of the APIs. This avoids + calls to spurious functions if all transforms are disabled and slightly + simplifies those functions. Pngvalid modified to handle this. + A minor change is to stop the strip_16 and expand_16 interfaces from + disabling each other; this allows the future alpha premultiplication + code to use 16-bit intermediate values while still producing 8-bit output. + png_do_background and png_do_gamma have been simplified to take a single + pointer to the png_struct rather than pointers to every item required + from the png_struct. This makes no practical difference to the internal + code. + A serious bug in the pngvalid internal routine 'standard_display_init' has + been fixed - this failed to initialize the red channel and accidentally + initialized the alpha channel twice. + Changed png_struct jmp_buf member name from png_jmpbuf to tmp_jmpbuf to + avoid a possible clash with the png_jmpbuf macro on some platforms. + +Version 1.5.3beta05 [May 6, 2011] + Added the "_POSIX_SOURCE" feature test macro to ensure libpng sees the + correct API. _POSIX_SOURCE is defined in pngpriv.h, pngtest.c and + pngvalid.c to ensure that POSIX conformant systems disable non-POSIX APIs. + Removed png_snprintf and added formatted warning messages. This change adds + internal APIs to allow png_warning messages to have parameters without + requiring the host OS to implement snprintf. As a side effect the + dependency of the tIME-supporting RFC1132 code on stdio is removed and + PNG_NO_WARNINGS does actually work now. + Pass "" instead of '\0' to png_default_error() in png_err(). This mistake + was introduced in libpng-1.2.20beta01. This fixes CVE-2011-2691. + Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte + optimization configurable. + IDAT compression failed if preceded by a compressed text chunk (bug + introduced in libpng-1.5.3beta01-02). This was because the attempt to + reset the zlib stream in png_write_IDAT happened after the first IDAT + chunk had been deflated - much too late. In this change internal + functions were added to claim/release the z_stream and, hopefully, make + the code more robust. Also deflateEnd checking is added - previously + libpng would ignore an error at the end of the stream. + +Version 1.5.3beta06 [May 8, 2011] + Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt + Implemented premultiplied alpha support: png_set_alpha_mode API + +Version 1.5.3beta07 [May 11, 2011] + Added expand_16 support to the high level interface. + Added named value and 'flag' gamma support to png_set_gamma. Made a minor + change from the previous (unreleased) ABI/API to hide the exact value used + for Macs - it's not a good idea to embed this in the ABI! + Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT + from pngpriv.h to png.h because they must be visible to applications + that call png_set_unknown_chunks(). + Check for up->location !PNG_AFTER_IDAT when writing unknown chunks + before IDAT. + +Version 1.5.3beta08 [May 16, 2011] + Improved "pngvalid --speed" to exclude more of pngvalid from the time. + Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt + The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative + parameters are supplied by the caller), while in the absence of cHRM + sRGB/Rec 709 values are still used. This introduced a divide-by-zero + bug in png_handle_cHRM(). + The bKGD chunk no longer overwrites the background value set by + png_set_background(), allowing the latter to be used before the file + header is read. It never performed any useful function to override + the default anyway. + Added memory overwrite and palette image checks to pngvalid.c + Previously palette image code was poorly checked. Since the transformation + code has a special palette path in most cases this was a severe weakness. + Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When + expanding an indexed image, always expand to RGBA if transparency is + present. + +Version 1.5.3beta09 [May 17, 2011] + Reversed earlier 1.5.3 change of transformation order; move png_expand_16 + back where it was. The change doesn't work because it requires 16-bit + gamma tables when the code only generates 8-bit ones. This fails + silently; the libpng code just doesn't do any gamma correction. Moving + the tests back leaves the old, inaccurate, 8-bit gamma calculations, but + these are clearly better than none! + +Version 1.5.3beta10 [May 20, 2011] + + png_set_background() and png_expand_16() did not work together correctly. + This problem is present in 1.5.2; if png_set_background is called with + need_expand false and the matching 16 bit color libpng erroneously just + treats it as an 8-bit color because of where png_do_expand_16 is in the + transform list. This simple fix reduces the supplied colour to 8-bits, + so it gets smashed, but this is better than the current behavior. + Added tests for expand16, more fixes for palette image tests to pngvalid. + Corrects the code for palette image tests and disables attempts to + validate palette colors. + +Version 1.5.3rc01 [June 3, 2011] + No changes. + +Version 1.5.3rc02 [June 8, 2011] + Fixed uninitialized memory read in png_format_buffer() (Bug report by + Frank Busse, CVE-2011-2501, related to CVE-2004-0421). + +Version 1.5.3beta11 [June 11, 2011] + Fixed png_handle_sCAL which is broken in 1.5. This fixes CVE 2011-2692. + Added sCAL to pngtest.png + Revised documentation about png_set_user_limits() to say that it also affects + png writing. + Revised handling of png_set_user_limits() so that it can increase the + limit beyond the PNG_USER_WIDTH|HEIGHT_MAX; previously it could only + reduce it. + Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is + wrong (high by one) 25% of the time. Dividing by 257 with rounding is + wrong in 128 out of 65536 cases. Getting the right answer all the time + without division is easy. + Added "_SUPPORTED" to the PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION macro. + Added projects/owatcom, an IDE project for OpenWatcom to replace + scripts/makefile.watcom. This project works with OpenWatcom 1.9. The + IDE autogenerates appropriate makefiles (libpng.mk) for batch processing. + The project is configurable, unlike the Visual Studio project, so long + as the developer has an awk. + Changed png_set_gAMA to limit the gamma value range so that the inverse + of the stored value cannot overflow the fixed point representation, + and changed other things OpenWatcom warns about. + Revised pngvalid.c to test PNG_ALPHA_MODE_SUPPORTED correctly. This allows + pngvalid to build when ALPHA_MODE is not supported, which is required if + it is to build on libpng 1.4. + Removed string/memory macros that are no longer used and are not + necessarily fully supportable, particularly png_strncpy and png_snprintf. + Added log option to pngvalid.c and attempted to improve gamma messages. + +Version 1.5.3 [omitted] + People found the presence of a beta release following an rc release + to be confusing; therefore we bump the version to libpng-1.5.4beta01 + and there will be no libpng-1.5.3 release. + +Version 1.5.4beta01 [June 14, 2011] + Made it possible to undefine PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED + to get the same (inaccurate) output as libpng-1.5.2 and earlier. + Moved definitions of PNG_HAVE_IHDR, PNG_AFTER_IDAT, and PNG_HAVE_PLTE + outside of an unknown-chunk block in png.h because they are also + needed for other uses. + +Version 1.5.4beta02 [June 14, 2011] + Fixed and clarified LEGACY 16-to-8 scaling code. + Added png_set_chop_16() API, to match inaccurate results from previous + libpng versions. + Removed the ACCURATE and LEGACY options (they are no longer useable) + Use the old scaling method for background if png_set_chop_16() was + called. + Made png_set_chop_16() API removeable by disabling PNG_CHOP_16_TO_8_SUPPORTED + +Version 1.5.4beta03 [June 15, 2011] + Fixed a problem in png_do_expand_palette() exposed by optimization in + 1.5.3beta06 + Also removed a spurious and confusing "trans" member ("trans") from png_info. + The palette expand optimization prevented expansion to an intermediate RGBA + form if tRNS was present but alpha was marked to be stripped; this exposed + a check for tRNS in png_do_expand_palette() which is inconsistent with the + code elsewhere in libpng. + Correction to the expand_16 code; removed extra instance of + png_set_scale_16_to_8 from pngpriv.h + +Version 1.5.4beta04 [June 16, 2011] + Added a missing "#ifdef PNG_READ_BACKGROUND_SUPPORTED/#endif" in pngrtran.c + Added PNG_TRANSFORM_CHOP_16 to the high-level read transforms. + Made PNG_READ_16_TO_8_ACCURATE_SCALE configurable again. If this is + not enabled, png_set_strip_16() and png_do_scale_16_to_8() aren't built. + Revised contrib/visupng, gregbook, and pngminim to demonstrate chop_16_to_8 + +Version 1.5.4beta05 [June 16, 2011] + Renamed png_set_strip_16() to png_set_scale_16() and renamed + png_set_chop_16() to png_set_strip(16) in an attempt to minimize the + behavior changes between libpng14 and libpng15. + +Version 1.5.4beta06 [June 18, 2011] + Fixed new bug that was causing both strip_16 and scale_16 to be applied. + +Version 1.5.4beta07 [June 19, 2011] + Fixed pngvalid, simplified macros, added checking for 0 in sCAL. + The ACCURATE scale macro is no longer defined in 1.5 - call the + png_scale_16_to_8 API. Made sure that PNG_READ_16_TO_8 is still defined + if the png_strip_16_to_8 API is present. png_check_fp_number now + maintains some state so that positive, negative and zero values are + identified. sCAL uses these to be strictly spec conformant. + +Version 1.5.4beta08 [June 23, 2011] + Fixed pngvalid if ACCURATE_SCALE is defined. + Updated scripts/pnglibconf.h.prebuilt. + +Version 1.5.4rc01 [June 30, 2011] + Define PNG_ALLOCATED to "restrict" only if MSC_VER >= 1400. + +Version 1.5.4 [July 7, 2011] + No changes. + +Version 1.5.5beta01 [July 13, 2011] + Fixed some typos and made other minor changes in the manual. + Updated contrib/pngminus/makefile.std (Samuli Souminen) + +Version 1.5.5beta02 [July 14, 2011] + Revised Makefile.am and Makefile.in to look in the right directory for + pnglibconf.h.prebuilt + +Version 1.5.5beta03 [July 27, 2011] + Enabled compilation with g++ compiler. This compiler does not recognize + the file extension, so it always compiles with C++ rules. Made minor + changes to pngrutil.c to cast results where C++ expects it but C does not. + Minor editing of libpng.3 and libpng-manual.txt. + +Version 1.5.5beta04 [July 29, 2011] + Revised CMakeLists.txt (Clifford Yapp) + Updated commentary about the png_rgb_to_gray() default coefficients + in the manual and in pngrtran.c + +Version 1.5.5beta05 [August 17, 2011] + Prevent unexpected API exports from non-libpng DLLs on Windows. The "_DLL" + is removed from the test of whether a DLL is being built (this erroneously + caused the libpng APIs to be marked as DLL exports in static builds under + Microsoft Visual Studio). Almost all of the libpng building configuration + is moved from pngconf.h to pngpriv.h, but PNG_DLL_EXPORT remains in + pngconf.h, though, so that it is colocated with the import definition (it + is no longer used anywhere in the installed headers). The VStudio project + definitions have been cleaned up: "_USRDLL" has been removed from the + static library builds (this was incorrect), and PNG_USE_DLL has been added + to pngvalid to test the functionality (pngtest does not supply it, + deliberately). The spurious "_EXPORTS" has been removed from the + libpng build (all these errors were a result of copy/paste between project + configurations.) + Added new types and internal functions for CIE RGB end point handling to + pngpriv.h (functions yet to be implemented). + +Version 1.5.5beta06 [August 26, 2011] + Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set in CMakeLists.txt + (Clifford Yap) + Fixes to rgb_to_gray and cHRM XYZ APIs (John Bowler): + The rgb_to_gray code had errors when combined with gamma correction. + Some pixels were treated as true grey when they weren't and such pixels + and true grey ones were not gamma corrected (the original value of the + red component was used instead). APIs to get and set cHRM using color + space end points have been added and the rgb_to_gray code that defaults + based on cHRM, and the divide-by-zero bug in png_handle_cHRM (CERT + VU#477046, CVE-2011-3328, introduced in 1.5.4) have been corrected. + A considerable number of tests has been added to pngvalid for the + rgb_to_gray transform. + Arithmetic errors in rgb_to_gray whereby the calculated gray value was + truncated to the bit depth rather than rounded have been fixed except in + the 8-bit non-gamma-corrected case (where consistency seems more important + than correctness.) The code still has considerable inaccuracies in the + 8-bit case because 8-bit linear arithmetic is used. + +Version 1.5.5beta07 [September 7, 2011] + Added "$(ARCH)" option to makefile.darwin + Added SunOS support to configure.ac and Makefile.am + Changed png_chunk_benign_error() to png_warning() in png.c, in + png_XYZ_from_xy_checked(). + +Version 1.5.5beta08 [September 10, 2011] + Fixed 64-bit compilation errors (gcc). The errors fixed relate + to conditions where types that are 32 bits in the GCC 32-bit + world (uLong and png_size_t) become 64 bits in the 64-bit + world. This produces potential truncation errors which the + compiler correctly flags. + Relocated new HAVE_SOLARIS_LD definition in configure.ac + Constant changes for 64-bit compatibility (removal of L suffixes). The + 16-bit cases still use "L" as we don't have a 16-bit test system. + +Version 1.5.5rc01 [September 15, 2011] + Removed "L" suffixes in pngpriv.h + +Version 1.5.5 [September 22, 2011] + No changes. + +Version 1.5.6beta01 [September 22, 2011] + Fixed some 64-bit type conversion warnings in pngrtran.c + Moved row_info from png_struct to a local variable. + The various interlace mask arrays have been made into arrays of + bytes and made PNG_CONST and static (previously some arrays were + marked PNG_CONST and some weren't). + Additional checks have been added to the transform code to validate the + pixel depths after the transforms on both read and write. + Removed some redundant code from pngwrite.c, in png_destroy_write_struct(). + Changed chunk reading/writing code to use png_uint_32 instead of png_byte[4]. + This removes the need to allocate temporary strings for chunk names on + the stack in the read/write code. Unknown chunk handling still uses the + string form because this is exposed in the API. + +Version 1.5.6beta02 [September 26, 2011] + Added a note in the manual the png_read_update_info() must be called only + once with a particular info_ptr. + Fixed a typo in the definition of the new PNG_STRING_FROM_CHUNK(s,c) macro. + +Version 1.5.6beta03 [September 28, 2011] + Revised test-pngtest.sh to report FAIL when pngtest fails. + Added "--strict" option to pngtest, to report FAIL when the failure is + only because the resulting valid files are different. + Revised CMakeLists.txt to work with mingw and removed some material from + CMakeLists.txt that is no longer useful in libpng-1.5. + +Version 1.5.6beta04 [October 5, 2011] + Fixed typo in Makefile.in and Makefile.am ("-M Wl" should be "-M -Wl")." + +Version 1.5.6beta05 [October 12, 2011] + Speed up png_combine_row() for interlaced images. This reduces the generality + of the code, allowing it to be optimized for Adam7 interlace. The masks + passed to png_combine_row() are now generated internally, avoiding + some code duplication and localizing the interlace handling somewhat. + Align png_struct::row_buf - previously it was always unaligned, caused by + a bug in the code that attempted to align it; the code needs to subtract + one from the pointer to take account of the filter byte prepended to + each row. + Optimized png_combine_row() when rows are aligned. This gains a small + percentage for 16-bit and 32-bit pixels in the typical case where the + output row buffers are appropriately aligned. The optimization was not + previously possible because the png_struct buffer was always misaligned. + Fixed bug in png_write_chunk_header() debug print, introduced in 1.5.6beta01. + +Version 1.5.6beta06 [October 17, 2011] + Removed two redundant tests for uninitialized row. + Fixed a relatively harmless memory overwrite in compressed text writing + with a 1 byte zlib buffer. + Add ability to call png_read_update_info multiple times to pngvalid.c. + Fixes for multiple calls to png_read_update_info. These fixes attend to + most of the errors revealed in pngvalid, however doing the gamma work + twice results in inaccuracies that can't be easily fixed. There is now + a warning in the code if this is going to happen. + Turned on multiple png_read_update_info in pngvalid transform tests. + Prevent libpng from overwriting unused bits at the end of the image when + it is not byte aligned, while reading. Prior to libpng-1.5.6 libpng would + overwrite the partial byte at the end of each row if the row width was not + an exact multiple of 8 bits and the image is not interlaced. + +Version 1.5.6beta07 [October 21, 2011] + Made png_ptr->prev_row an aligned pointer into png_ptr->big_prev_row + (Mans Rullgard). + +Version 1.5.6rc01 [October 26, 2011] + Changed misleading "Missing PLTE before cHRM" warning to "Out of place cHRM" + +Version 1.5.6rc02 [October 27, 2011] + Added LSR() macro to defend against buggy compilers that evaluate non-taken + code branches and complain about out-of-range shifts. + +Version 1.5.6rc03 [October 28, 2011] + Renamed the LSR() macro to PNG_LSR() and added PNG_LSL() macro. + Fixed compiler warnings with Intel and MSYS compilers. The logical shift + fix for Microsoft Visual C is required by other compilers, so this + enables that fix for all compilers when using compile-time constants. + Under MSYS 'byte' is a name declared in a system header file, so we + changed the name of a local variable to avoid the warnings that result. + Added #define PNG_ALIGN_TYPE PNG_ALIGN_NONE to contrib/pngminim/*/pngusr.h + +Version 1.5.6 [November 3, 2011] + No changes. + +Version 1.5.7beta01 [November 4, 2011] + Added support for ARM processor, when decoding all PNG up-filtered rows + and any other-filtered rows with 3 or 4 bytes per pixel (Mans Rullgard). + Fixed bug in pngvalid on early allocation failure; fixed type cast in + pngmem.c; pngvalid would attempt to call png_error() if the allocation + of a png_struct or png_info failed. This would probably have led to a + crash. The pngmem.c implementation of png_malloc() included a cast + to png_size_t which would fail on large allocations on 16-bit systems. + Fix for the preprocessor of the Intel C compiler. The preprocessor + splits adjacent @ signs with a space; this changes the concatenation + token from @-@-@ to PNG_JOIN; that should work with all compiler + preprocessors. + Paeth filter speed improvements from work by Siarhei Siamashka. This + changes the 'Paeth' reconstruction function to improve the GCC code + generation on x86. The changes are only part of the suggested ones; + just the changes that definitely improve speed and remain simple. + The changes also slightly increase the clarity of the code. + +Version 1.5.7beta02 [November 11, 2011] + Check compression_type parameter in png_get_iCCP and remove spurious + casts. The compression_type parameter is always assigned to, so must + be non-NULL. The cast of the profile length potentially truncated the + value unnecessarily on a 16-bit int system, so the cast of the (byte) + compression type to (int) is specified by ANSI-C anyway. + Fixed FP division by zero in pngvalid.c; the 'test_pixel' code left + the sBIT fields in the test pixel as 0, which resulted in a floating + point division by zero which was irrelevant but causes systems where + FP exceptions cause a crash. Added code to pngvalid to turn on FP + exceptions if the appropriate glibc support is there to ensure this is + tested in the future. + Updated scripts/pnglibconf.mak and scripts/makefile.std to handle the + new PNG_JOIN macro. + Added versioning to pnglibconf.h comments. + Simplified read/write API initial version; basic read/write tested on + a variety of images, limited documentation (in the header file.) + Installed more accurate linear to sRGB conversion tables. The slightly + modified tables reduce the number of 16-bit values that + convert to an off-by-one 8-bit value. The "makesRGB.c" code that was used + to generate the tables is now in a contrib/sRGBtables sub-directory. + +Version 1.5.7beta03 [November 17, 2011] + Removed PNG_CONST from the sRGB table declarations in pngpriv.h and png.c + Added run-time detection of NEON support. + Added contrib/libtests; includes simplified API test and timing test and + a color conversion utility for rapid checking of failed 'pngstest' results. + Multiple transform bug fixes plus a work-round for double gamma correction. + libpng does not support more than one transform that requires linear data + at once - if this is tried typically the results is double gamma + correction. Since the simplified APIs can need rgb to gray combined with + a compose operation it is necessary to do one of these outside the main + libpng transform code. This check-in also contains fixes to various bugs + in the simplified APIs themselves and to some bugs in compose and rgb to + gray (on palette) itself. + Fixes for C++ compilation using g++ When libpng source is compiled + using g++. The compiler imposes C++ rules on the C source; thus it + is desirable to make the source work with either C or C++ rules + without throwing away useful error information. This change adds + png_voidcast to allow C semantic (void*) cases or the corresponding + C++ static_cast operation, as appropriate. + Added --noexecstack to assembler file compilation. GCC does not set + this on assembler compilation, even though it does on C compilation. + This creates security issues if assembler code is enabled; the + work-around is to set it by default in the flags for $(CCAS) + Work around compilers that don't support declaration of const data. Some + compilers fault 'extern const' data declarations (because the data is + not initialized); this turns on const-ness only for compilers where + this is known to work. + +Version 1.5.7beta04 [November 17, 2011] + Since the gcc driver does not recognize the --noexecstack flag, we must + use the -Wa prefix to have it passed through to the assembler. + Also removed a duplicate setting of this flag. + Added files that were omitted from the libpng-1.5.7beta03 zip distribution. + +Version 1.5.7beta05 [November 25, 2011] + Removed "zTXt" from warning in generic chunk decompression function. + Validate time settings passed to png_set_tIME() and png_convert_to_rfc1123() + (Frank Busse). Note: This prevented CVE-2015-7981 from affecting + libpng-1.5.7 and later. + Added MINGW support to CMakeLists.txt + Reject invalid compression flag or method when reading the iTXt chunk. + Backed out 'simplified' API changes. The API seems too complex and there + is a lack of consensus or enthusiasm for the proposals. The API also + reveals significant bugs inside libpng (double gamma correction and the + known bug of being unable to retrieve a corrected palette). It seems + better to wait until the bugs, at least, are corrected. + Moved pngvalid.c into contrib/libtests + Rebuilt Makefile.in, configure, etc., with autoconf-2.68 + +Version 1.5.7rc01 [December 1, 2011] + Replaced an "#if" with "#ifdef" in pngrtran.c + Revised #if PNG_DO_BC block in png.c (use #ifdef and add #else) + +Version 1.5.7rc02 [December 5, 2011] + Revised project files and contrib/pngvalid/pngvalid.c to account for + the relocation of pngvalid into contrib/libtests. + Revised pngconf.h to use " __declspec(restrict)" only when MSC_VER >= 1400, + as in libpng-1.5.4. + Put CRLF line endings in the owatcom project files. + +Version 1.5.7rc03 [December 7, 2011] + Updated CMakeLists.txt to account for the relocation of pngvalid.c + +Version 1.5.7 [December 15, 2011] + Minor fixes to pngvalid.c for gcc 4.6.2 compatibility to remove warnings + reported by earlier versions. + Fixed minor memset/sizeof errors in pngvalid.c. + +Version 1.6.0beta01 [December 15, 2011] + Removed machine-generated configure files from the GIT repository (they will + continue to appear in the tarball distributions and in the libpng15 and + earlier GIT branches). + Restored the new 'simplified' API, which was started in libpng-1.5.7beta02 + but later deleted from libpng-1.5.7beta05. + Added example programs for the new 'simplified' API. + Added ANSI-C (C90) headers and require them, and take advantage of the + change. Also fixed some of the projects/* and contrib/* files that needed + updates for libpng16 and the move of pngvalid.c. + With this change the required ANSI-C header files are assumed to exist: the + implementation must provide float.h, limits.h, stdarg.h and stddef.h and + libpng relies on limits.h and stddef.h existing and behaving as defined + (the other two required headers aren't used). Non-ANSI systems that don't + have stddef.h or limits.h will have to provide an appropriate fake + containing the relevant types and #defines. + Dropped support for 16-bit platforms. The use of FAR/far has been eliminated + and the definition of png_alloc_size_t is now controlled by a flag so + that 'small size_t' systems can select it if necessary. Libpng 1.6 may + not currently work on such systems -- it seems likely that it will + ask 'malloc' for more than 65535 bytes with any image that has a + sufficiently large row size (rather than simply failing to read such + images). + New tools directory containing tools used to generate libpng code. + Fixed race conditions in parallel make builds. With higher degrees of + parallelism during 'make' the use of the same temporary file names such + as 'dfn*' can result in a race where a temporary file from one arm of the + build is deleted or overwritten in another arm. This changes the + temporary files for suffix rules to always use $* and ensures that the + non-suffix rules use unique file names. + +Version 1.6.0beta02 [December 21, 2011] + Correct configure builds where build and source directories are separate. + The include path of 'config.h' was erroneously made relative in pngvalid.c + in libpng 1.5.7. + +Version 1.6.0beta03 [December 22, 2011] + Start-up code size improvements, error handler flexibility. These changes + alter how the tricky allocation of the initial png_struct and png_info + structures are handled. png_info is now handled in pretty much the same + way as everything else, except that the allocations handle NULL return + silently. png_struct is changed in a similar way on allocation and on + deallocation a 'safety' error handler is put in place (which should never + be required). The error handler itself is changed to permit mismatches + in the application and libpng error buffer size; however, this means a + silent change to the API to return the jmp_buf if the size doesn't match + the size from the libpng compilation; libpng now allocates the memory and + this may fail. Overall these changes result in slight code size + reductions; however, this is a reduction in code that is always executed + so is particularly valuable. Overall on a 64-bit system the libpng DLL + decreases in code size by 1733 bytes. pngerror.o increases in size by + about 465 bytes because of the new functionality. + Added png_convert_to_rfc1123_buffer() and deprecated png_convert_to_rfc1123() + to avoid including a spurious buffer in the png_struct. + +Version 1.6.0beta04 [December 30, 2011] + Regenerated configure scripts with automake-1.11.2 + Eliminated png_info_destroy(). It is now used only in png.c and only calls + one other internal function and memset(). + Enabled png_get_sCAL_fixed() if floating point APIs are enabled. Previously + it was disabled whenever internal fixed point arithmetic was selected, + which meant it didn't exist even on systems where FP was available but not + preferred. + Added pngvalid.c compile time checks for const APIs. + Implemented 'restrict' for png_info and png_struct. Because of the way + libpng works both png_info and png_struct are always accessed via a + single pointer. This means adding C99 'restrict' to the pointer gives + the compiler some opportunity to optimize the code. This change allows + that. + Moved AC_MSG_CHECKING([if libraries can be versioned]) later to the proper + location in configure.ac (Gilles Espinasse). + Changed png_memcpy to C assignment where appropriate. Changed all those + uses of png_memcpy that were doing a simple assignment to assignments + (all those cases where the thing being copied is a non-array C L-value). + Added some error checking to png_set_*() routines. + Removed the reference to the non-exported function png_memcpy() from + example.c. + Fixed the Visual C 64-bit build - it requires jmp_buf to be aligned, but + it had become misaligned. + Revised contrib/pngminus/pnm2png.c to avoid warnings when png_uint_32 + and unsigned long are of different sizes. + +Version 1.6.0beta05 [January 15, 2012] + Updated manual with description of the simplified API (copied from png.h) + Fix bug in pngerror.c: some long warnings were being improperly truncated + (CVE-2011-3464, bug introduced in libpng-1.5.3beta05). + +Version 1.6.0beta06 [January 24, 2012] + Added palette support to the simplified APIs. This commit + changes some of the macro definitions in png.h, app code + may need corresponding changes. + Increased the formatted warning buffer to 192 bytes. + Added color-map support to simplified API. This is an initial version for + review; the documentation has not yet been updated. + Fixed Min/GW uninstall to remove libpng.dll.a + +Version 1.6.0beta07 [January 28, 2012] + Eliminated Intel icc/icl compiler warnings. The Intel (GCC derived) + compiler issues slightly different warnings from those issued by the + current vesions of GCC. This eliminates those warnings by + adding/removing casts and small code rewrites. + Updated configure.ac from autoupdate: added --enable-werror option. + Also some layout regularization and removal of introduced tab characters + (replaced with 3-character indentation). Obsolete macros identified by + autoupdate have been removed; the replacements are all in 2.59 so + the pre-req hasn't been changed. --enable-werror checks for support + for -Werror (or the given argument) in the compiler. This mimics the + gcc configure option by allowing -Werror to be turned on safely; without + the option the tests written in configure itself fail compilation because + they cause compiler warnings. + Rewrote autogen.sh to run autoreconf instead of running tools one-by-one. + Conditionalize the install rules for MINGW and CYGWIN in CMakeLists.txt and + set CMAKE_LIBRARY_OUTPUT_DIRECTORY to "lib" on all platforms (C. Yapp). + Freeze libtool files in the 'scripts' directory. This version of autogen.sh + attempts to dissuade people from running it when it is not, or should not, + be necessary. In fact, autogen.sh does not work when run in a libpng + directory extracted from a tar distribution anymore. You must run it in + a GIT clone instead. + Added two images to contrib/pngsuite (1-bit and 2-bit transparent grayscale), + and renamed three whose names were inconsistent with those in + pngsuite/README.txt. + +Version 1.6.0beta08 [February 1, 2012] + Fixed Image::colormap misalignment in pngstest.c + Check libtool/libtoolize version number (2.4.2) in configure.ac + Divide test-pngstest.sh into separate pngstest runs for basic and + transparent images. + Moved automake options to AM_INIT_AUTOMAKE in configure.ac + Added color-tests, silent-rules (Not yet implemented in Makefile.am) and + version checking to configure.ac + Improved pngstest speed by not doing redundant tests and add const to + the background parameter of png_image_finish_read. The --background + option is now done automagically only when required, so that commandline + option no longer exists. + Cleaned up pngpriv.h to consistently declare all functions and data. + Also eliminated PNG_CONST_DATA, which is apparently not needed but we + can't be sure until it is gone. + Added symbol prefixing that allows all the libpng external symbols + to be prefixed (suggested by Reuben Hawkins). + Updated "ftbb*.png" list in the owatcom and vstudio projects. + Fixed 'prefix' builds on clean systems. The generation of pngprefix.h + should not require itself. + Updated INSTALL to explain that autogen.sh must be run in a GIT clone, + not in a libpng directory extracted from a tar distribution. + +Version 1.6.0beta09 [February 1, 2012] + Reverted the prebuilt configure files to libpng-1.6.0beta05 condition. + +Version 1.6.0beta10 [February 3, 2012] + Added Z_SOLO for zlib-1.2.6+ and correct pngstest tests + Updated list of test images in CMakeLists.txt + Updated the prebuilt configure files to current condition. + Revised INSTALL information about autogen.sh; it works in tar distributions. + +Version 1.6.0beta11 [February 16, 2012] + Fix character count in pngstest command in projects/owatcom/pngstest.tgt + Revised test-pngstest.sh to report PASS/FAIL for each image. + Updated documentation about the simplified API. + Corrected estimate of error in libpng png_set_rgb_to_gray API. The API is + extremely inaccurate for sRGB conversions because it uses an 8-bit + intermediate linear value and it does not use the sRGB transform, so it + suffers from the known instability in gamma transforms for values close + to 0 (see Poynton). The net result is that the calculation has a maximum + error of 14.99/255; 0.5/255^(1/2.2). pngstest now uses 15 for the + permitted 8-bit error. This may still not be enough because of arithmetic + error. + Removed some unused arrays (with #ifdef) from png_read_push_finish_row(). + Fixed a memory overwrite bug in simplified read of RGB PNG with + non-linear gamma Also bugs in the error checking in pngread.c and changed + quite a lot of the checks in pngstest.c to be correct; either correctly + written or not over-optimistic. The pngstest changes are insufficient to + allow all possible RGB transforms to be passed; pngstest cmppixel needs + to be rewritten to make it clearer which errors it allows and then changed + to permit known inaccuracies. + Removed tests for no-longer-used *_EMPTY_PLTE_SUPPORTED from pngstruct.h + Fixed fixed/float API export conditionals. 1) If FIXED_POINT or + FLOATING_POINT options were switched off, png.h ended up with lone ';' + characters. This is not valid ANSI-C outside a function. The ';' + characters have been moved inside the definition of PNG_FP_EXPORT and + PNG_FIXED_EXPORT. 2) If either option was switched off, the declaration + of the corresponding functions were completely omitted, even though some + of them are still used internally. The result is still valid, but + produces warnings from gcc with some warning options (including -Wall). The + fix is to cause png.h to declare the functions with PNG_INTERNAL_FUNCTION + when png.h is included from pngpriv.h. + Check for invalid palette index while reading paletted PNG. When one is + found, issue a warning and increase png_ptr->num_palette accordingly. + Apps are responsible for checking to see if that happened. + +Version 1.6.0beta12 [February 18, 2012] + Do not increase num_palette on invalid_index. + Relocated check for invalid palette index to pngrtran.c, after unpacking + the sub-8-bit pixels. + Fixed CVE-2011-3026 buffer overrun bug. This bug was introduced when + iCCP chunk support was added at libpng-1.0.6. Deal more correctly with the + test on iCCP chunk length. Also removed spurious casts that may hide + problems on 16-bit systems. + +Version 1.6.0beta13 [February 24, 2012] + Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from + pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c; + now that png_ptr->buffer is inaccessible to applications, the special + handling is no longer useful. + Added PNG_SAFE_LIMITS feature to pnglibconf.dfa, pngpriv.h, and new + pngusr.dfa to reset the user limits to safe ones if PNG_SAFE_LIMITS is + defined. To enable, use "CPPFLAGS=-DPNG_SAFE_LIMITS_SUPPORTED=1" on the + configure command or put #define PNG_SAFE_LIMITS_SUPPORTED in + pnglibconf.h.prebuilt and pnglibconf.h. + +Version 1.6.0beta14 [February 27, 2012] + Added information about the new limits in the manual. + Updated Makefile.in + +Version 1.6.0beta15 [March 2, 2012] + Removed unused "current_text" members of png_struct and the png_free() + of png_ptr->current_text from pngread.c + Rewrote pngstest.c for substantial speed improvement. + Fixed transparent pixel and 16-bit rgb tests in pngstest and removed a + spurious check in pngwrite.c + Added PNG_IMAGE_FLAG_FAST for the benefit of applications that store + intermediate files, or intermediate in-memory data, while processing + image data with the simplified API. The option makes the files larger + but faster to write and read. pngstest now uses this by default; this + can be disabled with the --slow option. + Improved pngstest fine tuning of error numbers, new test file generator. + The generator generates images that test the full range of sample values, + allow the error numbers in pngstest to be tuned and checked. makepng + also allows generation of images with extra chunks, although this is + still work-in-progress. + Added check for invalid palette index while reading. + Fixed some bugs in ICC profile writing. The code should now accept + all potentially valid ICC profiles and reject obviously invalid ones. + It now uses png_error() to do so rather than casually writing a PNG + without the necessary color data. + Removed whitespace from the end of lines in all source files and scripts. + +Version 1.6.0beta16 [March 6, 2012] + Relocated palette-index checking function from pngrutil.c to pngtrans.c + Added palette-index checking while writing. + Changed png_inflate() and calling routines to avoid overflow problems. + This is an intermediate check-in that solves the immediate problems and + introduces one performance improvement (avoiding a copy via png_ptr->zbuf.) + Further changes will be made to make ICC profile handling more secure. + Fixed build warnings (MSVC, GCC, GCC v3). Cygwin GCC with default options + declares 'index' as a global, causing a warning if it is used as a local + variable. GCC 64-bit warns about assigning a (size_t) (unsigned 64-bit) + to an (int) (signed 32-bit). MSVC, however, warns about using the + unary '-' operator on an unsigned value (even though it is well defined + by ANSI-C to be ~x+1). The padding calculation was changed to use a + different method. Removed the tests on png_ptr->pass. + Added contrib/libtests/tarith.c to test internal arithmetic functions from + png.c. This is a libpng maintainer program used to validate changes to the + internal arithmetic functions. + Made read 'inflate' handling like write 'deflate' handling. The read + code now claims and releases png_ptr->zstream, like the write code. + The bug whereby the progressive reader failed to release the zstream + is now fixed, all initialization is delayed, and the code checks for + changed parameters on deflate rather than always calling + deflatedEnd/deflateInit. + Validate the zTXt strings in pngvalid. + Added code to validate the windowBits value passed to deflateInit2(). + If the call to deflateInit2() is wrong a png_warning will be issued + (in fact this is harmless, but the PNG data produced may be sub-optimal). + +Version 1.6.0beta17 [March 10, 2012] + Fixed PNG_LIBPNG_BUILD_BASE_TYPE definition. + Reject all iCCP chunks after the first, even if the first one is invalid. + Deflate/inflate was reworked to move common zlib calls into single + functions [rw]util.c. A new shared keyword check routine was also added + and the 'zbuf' is no longer allocated on progressive read. It is now + possible to call png_inflate() incrementally. A warning is no longer + issued if the language tag or translated keyword in the iTXt chunk + has zero length. + If benign errors are disabled use maximum window on ancillary inflate. + This works round a bug introduced in 1.5.4 where compressed ancillary + chunks could end up with a too-small windowBits value in the deflate + header. + +Version 1.6.0beta18 [March 16, 2012] + Issue a png_benign_error() instead of png_warning() about bad palette index. + In pngtest, treat benign errors as errors if "-strict" is present. + Fixed an off-by-one error in the palette index checking function. + Fixed a compiler warning under Cygwin (Windows-7, 32-bit system) + Revised example.c to put text strings in a temporary character array + instead of directly assigning string constants to png_textp members. + This avoids compiler warnings when -Wwrite-strings is enabled. + Added output flushing to aid debugging under Visual Studio. Unfortunately + this is necessary because the VS2010 output window otherwise simply loses + the error messages on error (they weren't flushed to the window before + the process exited, apparently!) + Added configuration support for benign errors and changed the read + default. Also changed some warnings in the iCCP and sRGB handling + from to benign errors. Configuration now makes read benign + errors warnings and write benign errors to errors by default (thus + changing the behavior on read). The simplified API always forces + read benign errors to warnings (regardless of the system default, unless + this is disabled in which case the simplified API can't be built.) + +Version 1.6.0beta19 [March 18, 2012] + Work around for duplicate row start calls; added warning messages. + This turns on PNG_FLAG_DETECT_UNINITIALIZED to detect app code that + fails to call one of the 'start' routines (not enabled in libpng-1.5 + because it is technically an API change, since it did normally work + before.) It also makes duplicate calls to png_read_start_row (an + internal function called at the start of the image read) benign, as + they were before changes to use png_inflate_claim. Somehow webkit is + causing this to happen; this is probably a mis-feature in the zlib + changes so this commit is only a work-round. + Removed erroneous setting of DETECT_UNINITIALIZED and added more + checks. The code now does a png_error if an attempt is made to do the + row initialization twice; this is an application error and it has + serious consequences because the transform data in png_struct is + changed by each call. + Added application error reporting and added chunk names to read + benign errors; also added --strict to pngstest - not enabled + yet because a warning is produced. + Avoid the double gamma correction warning in the simplified API. + This allows the --strict option to pass in the pngstest checks + +Version 1.6.0beta20 [March 29, 2012] + Changed chunk handler warnings into benign errors, incrementally load iCCP + Added checksum-icc.c to contrib/tools + Prevent PNG_EXPAND+PNG_SHIFT doing the shift twice. + Recognize known sRGB ICC profiles while reading; prefer writing the + iCCP profile over writing the sRGB chunk, controlled by the + PNG_sRGB_PROFILE_CHECKS option. + Revised png_set_text_2() to avoid potential memory corruption (fixes + CVE-2011-3048, also known as CVE-2012-3425). + +Version 1.6.0beta21 [April 27, 2012] + Revised scripts/makefile.darwin: use system zlib; remove quotes around + architecture list; add missing ppc architecture; add architecture options + to shared library link; don't try to create a shared lib based on missing + RELEASE variable. + Enable png_set_check_for_invalid_index() for both read and write. + Removed #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED in pngpriv.h around + declaration of png_handle_unknown(). + Added -lssp_nonshared in a comment in scripts/makefile.freebsd + and changed deprecated NOOBJ and NOPROFILE to NO_OBJ and NO_PROFILE. + +Version 1.6.0beta22 [May 23, 2012] + Removed need for -Wno-cast-align with clang. clang correctly warns on + alignment increasing pointer casts when -Wcast-align is passed. This + fixes the cases that clang warns about either by eliminating the + casts from png_bytep to png_uint_16p (pngread.c), or, for pngrutil.c + where the cast is previously verified or pngstest.c where it is OK, by + introducing new png_aligncast macros to do the cast in a way that clang + accepts. + +Version 1.6.0beta23 [June 6, 2012] + Revised CMakeLists.txt to not attempt to make a symlink under mingw. + Made fixes for new optimization warnings from gcc 4.7.0. The compiler + performs an optimization which is safe; however it then warns about it. + Changing the type of 'palette_number' in pngvalid.c removes the warning. + Do not depend upon a GCC feature macro being available for use in generating + the linker mapfile symbol prefix. + Improved performance of new do_check_palette_indexes() function (only + update the value when it actually increases, move test for whether + the check is wanted out of the function. + +Version 1.6.0beta24 [June 7, 2012] + Don't check palette indexes if num_palette is 0 (as it can be in MNG files). + +Version 1.6.0beta25 [June 16, 2012] + Revised png_set_keep_unknown_chunks() so num_chunks < 0 means ignore all + unknown chunks and all known chunks except for IHDR, PLTE, tRNS, IDAT, + and IEND. Previously it only meant ignore all unknown chunks, the + same as num_chunks == 0. Revised png_image_skip_unused_chunks() to + provide a list of chunks to be processed instead of a list of chunks to + ignore. Revised contrib/gregbook/readpng2.c accordingly. + +Version 1.6.0beta26 [July 10, 2012] + Removed scripts/makefile.cegcc from the *.zip and *.7z distributions; it + depends on configure, which is not included in those archives. + Moved scripts/chkfmt to contrib/tools. + Changed "a+w" to "u+w" in Makefile.in to fix CVE-2012-3386. + +Version 1.6.0beta27 [August 11, 2012] + Do not compile PNG_DEPRECATED, PNG_ALLOC and PNG_PRIVATE when __GNUC__ < 3. + Do not use __restrict when GNUC is <= 3.1 + Removed references to png_zalloc() and png_zfree() from the manual. + Fixed configurations where floating point is completely disabled. Because + of the changes to support symbol prefixing PNG_INTERNAL_FUNCTION declares + floating point APIs during libpng builds even if they are completely + disabled. This requires the png floating point types (png_double*) to be + declared even though the functions are never actually defined. This + change provides a dummy definition so that the declarations work, yet any + implementation will fail to compile because of an incomplete type. + Re-eliminated the use of strcpy() in pngtest.c. An unnecessary use of + strcpy() was accidentally re-introduced in libpng16; this change replaces + it with strncpy(). + Eliminated use of png_sizeof(); use sizeof() instead. + Use a consistent style for (sizeof type) and (sizeof (array)) + Cleanup of png_set_filler(). This function does very different things on + read and write. In libpng 1.6 the two cases can be distinguished and + considerable code cleanup, and extra error checking, is possible. This + makes calls on the write side that have no effect be ignored with a + png_app_error(), which can be disabled in the app using + png_set_benign_errors(), and removes the spurious use of usr_channels + on the read side. + Insist on autotools 1.12.1 for git builds because there are security issues + with 1.12 and insisting on anything less would allow 1.12 to be used. + Removed info_ptr->signature[8] from WRITE-only builds. + Add some conditions for compiling png_fixed(). This is a small function + but it requires "-lm" on some platforms. + Cause pngtest --strict to fail on any warning from libpng (not just errors) + and cause it not to fail at the comparison step if libpng lacks support + for writing chunks that it reads from the input (currently only implemented + for compressed text chunks). + Make all three "make check" test programs work without READ or WRITE support. + Now "make check" will succeed even if libpng is compiled with -DPNG_NO_READ + or -DPNG_NO_WRITE. The tests performed are reduced, but the basic reading + and writing of a PNG file is always tested by one or more of the tests. + Consistently use strlen(), memset(), memcpy(), and memcmp() instead of the + png_strlen(), png_memset(), png_memcpy(), and png_memcmp() macros. + Removed the png_sizeof(), png_strlen(), png_memset(), png_memcpy(), and + png_memcmp() macros. + Work around gcc 3.x and Microsoft Visual Studio 2010 complaints. Both object + to the split initialization of num_chunks. + +Version 1.6.0beta28 [August 29, 2012] + Unknown handling fixes and clean up. This adds more correct option + control of the unknown handling, corrects the pre-existing bug where + the per-chunk 'keep' setting is ignored and makes it possible to skip + IDAT chunks in the sequential reader (broken in earlier 1.6 versions). + There is a new test program, test-unknown.c, which is a work in progress + (not currently part of the test suite). Comments in the header files now + explain how the unknown handling works. + Allow fine grain control of unknown chunk APIs. This change allows + png_set_keep_unknown_chunks() to be turned off if not required and causes + both read and write to behave appropriately (on read this is only possible + if the user callback is used to handle unknown chunks). The change + also removes the support for storing unknown chunks in the info_struct + if the only unknown handling enabled is via the callback, allowing libpng + to be configured with callback reading and none of the unnecessary code. + Corrected fix for unknown handling in pngtest. This reinstates the + libpng handling of unknown chunks other than vpAg and sTER (including + unsafe-to-copy chunks which were dropped before) and eliminates the + repositioning of vpAg and sTER in pngtest.png by changing pngtest.png + (so the chunks are where libpng would put them). + Added "tunknown" test and corrected a logic error in png_handle_unknown() + when SAVE support is absent. Moved the shell test scripts for + contrib/libtests from the libpng top directory to contrib/libtests. + png_handle_unknown() must always read or skip the chunk, if + SAVE_UNKNOWN_CHUNKS is turned off *and* the application does not set + a user callback an unknown chunk will not be read, leading to a read + error, which was revealed by the "tunknown" test. + Cleaned up and corrected ICC profile handling. + contrib/libtests/makepng: corrected 'rgb' and 'gray' cases. profile_error + messages could be truncated; made a correct buffer size calculation and + adjusted pngerror.c appropriately. png_icc_check_* checking improved; + changed the functions to receive the correct color type of the PNG on read + or write and check that it matches the color space of the profile (despite + what the comments said before, there is danger in assuming the app will + cope correctly with an RGB profile on a grayscale image and, since it + violates the PNG spec, allowing it is certain to produce inconsistent + app behavior and might even cause app crashes.) Check that profiles + contain the tags needed to process the PNG (tags all required by the ICC + spec). Removed unused PNG_STATIC from pngpriv.h. + +Version 1.6.0beta29 [September 4, 2012] + Fixed the simplified API example programs to add the *colormap parameter + to several of he API and improved the error message if the version field + is not set. + Added contrib/examples/* to the *.zip and *.7z distributions. + Updated simplified API synopses and description of the png_image structure + in the manual. + Made makepng and pngtest produce identical PNGs, add "--relaxed" option + to pngtest. The "--relaxed" option turns off the benign errors that are + enabled by default in pre-RC builds. makepng can now write ICC profiles + where the length has not been extended to a multiple of 4, and pngtest + now intercepts all libpng errors, allowing the previously-introduced + "--strict test" on no warnings to actually work. + Improved ICC profile handling including cHRM chunk generation and fixed + Cygwin+MSVC build errors. The ICC profile handling now includes more + checking. Several errors that caused rejection of the profile are now + handled with a warning in such a way that the invalid profiles will be + read by default in release (but not pre-RC) builds but will not be + written by default. The easy part of handling the cHRM chunk is written, + where the ICC profile contains the required data. The more difficult + part plus guessing a gAMA value requires code to pass selected RGB values + through the profile. + +Version 1.6.0beta30 [October 24, 2012] + Changed ICC profile matrix/vector types to not depend on array type rules. + By the ANSI-C standard the new types should be identical to the previous + versions, and all known versions of gcc tested with the previous versions + except for GCC-4.2.1 work with this version. The change makes the ANSI-C + rule that const applied to an array of elements applies instead to the + elements in the array moot by explicitly applying const to the base + elements of the png_icc_matrix and png_icc_vector types. The accidental + (harmless) 'const' previously applied to the parameters of two of the + functions have also been removed. + Added a work around for GCC 4.2 optimization bug. + Marked the broken (bad white point) original HP sRGB profiles correctly and + correct comments. + Added -DZ_SOLO to contrib/pngminim/*/makefile to work with zlib-1.2.7 + Use /MDd for vstudio debug builds. Also added pngunkown to the vstudio + builds, fixed build errors and corrected a minor exit code error in + pngvalid if the 'touch' file name is invalid. + Add updated WARNING file to projects/vstudio from libpng 1.5/vstudio + Fixed build when using #define PNG_NO_READ_GAMMA in png_do_compose() in + pngrtran.c (Domani Hannes). + +Version 1.6.0beta31 [November 1, 2012] + Undid the erroneous change to vstudio/pngvalid build in libpng-1.6.0beta30. + Made pngvalid so that it will build outside the libpng source tree. + Made builds -DPNG_NO_READ_GAMMA compile (the unit tests still fail). + Made PNG_NO_READ_GAMMA switch off interfaces that depend on READ_GAMMA. + Prior to 1.6.0 switching off READ_GAMMA did unpredictable things to the + interfaces that use it (specifically, png_do_background in 1.4 would + simply display composite for grayscale images but do composition + with the incorrect arithmetic for color ones). In 1.6 the semantic + of -DPNG_NO_READ_GAMMA is changed to simply disable any interface that + depends on it; this obliges people who set it to consider whether they + really want it off if they happen to use any of the interfaces in + question (typically most users who disable it won't). + Fixed GUIDs in projects/vstudio. Some were duplicated or missing, + resulting in VS2010 having to update the files. + Removed non-working ICC profile support code that was mostly added to + libpng-1.6.0beta29 and beta30. There was too much code for too little + gain; implementing full ICC color correction may be desirable but is left + up to applications. + +Version 1.6.0beta32 [November 25, 2012] + Fixed an intermittent SEGV in pngstest due to an uninitialized array element. + Added the ability for contrib/libtests/makepng.c to make a PNG with just one + color. This is useful for debugging pngstest color inaccuracy reports. + Fixed error checking in the simplified write API (Olaf van der Spek) + Made png_user_version_check() ok to use with libpng version 1.10.x and later. + +Version 1.6.0beta33 [December 15, 2012] + Fixed typo in png.c (PNG_SET_CHUNK_MALLOC_MAX should be PNG_CHUNK_MALLOC_MAX) + that causes the MALLOC_MAX limit not to work (John Bowler) + Change png_warning() to png_app_error() in pngwrite.c and comment the + fall-through condition. + Change png_warning() to png_app_warning() in png_write_tRNS(). + Rearranged the ARM-NEON optimizations: Isolated the machine specific code + to the hardware subdirectory and added comments to pngrutil.c so that + implementors of other optimizations know what to do. + Fixed cases of unquoted DESTDIR in Makefile.am + Rebuilt Makefile.in, etc., with autoconf-2.69 and automake-1.12.5. + +Version 1.6.0beta34 [December 19, 2012] + Cleaned up whitespace in the synopsis portion of the manpage "libpng.3" + Disassembled the version number in scripts/options.awk (necessary for + building on SunOs). + +Version 1.6.0beta35 [December 23, 2012] + Made default Zlib compression settings be configurable. This adds #defines to + pnglibconf.h to control the defaults. + Fixed Windows build issues, enabled ARM compilation. Various warnings issued + by earlier versions of GCC fixed for Cygwin and Min/GW (which both use old + GCCs.) ARM support is enabled by default in zlib.props (unsupported by + Microsoft) and ARM compilation is made possible by deleting the check for + x86. The test programs cannot be run because they are not signed. + +Version 1.6.0beta36 [January 2, 2013] + Discontinued distributing libpng-1.x.x.tar.bz2. + Discontinued distributing libpng-1.7.0-1.6.0-diff.txt and similar. + Rebuilt configure with autoconf-2.69 (inadvertently not done in beta33) + Fixed 'make distcheck' on SUN OS - libpng.so was not being removed + +Version 1.6.0beta37 [January 10, 2013] + Fixed conceivable but difficult to repro overflow. Also added two test + programs to generate and test a PNG which should have the problem. + +Version 1.6.0beta39 [January 19, 2013] + Again corrected attempt at overflow detection in png_set_unknown_chunks() + (CVE-2013-7353). Added overflow detection in png_set_sPLT() and + png_set_text_2() (CVE-2013-7354). + +Version 1.6.0beta40 [January 20, 2013] + Use consistent handling of overflows in text, sPLT and unknown png_set_* APIs + +Version 1.6.0rc01 [January 26, 2013] + No changes. + +Version 1.6.0rc02 [February 4, 2013] + Added png_get_palette_max() function. + +Version 1.6.0rc03 [February 5, 2013] + Fixed the png_get_palette_max API. + +Version 1.6.0rc04 [February 7, 2013] + Turn serial tests back on (recently turned off by autotools upgrade). + +Version 1.6.0rc05 [February 8, 2013] + Update manual about png_get_palette_max(). + +Version 1.6.0rc06 [February 9, 2013] + Fixed missing dependency in --prefix builds The intermediate + internal 'prefix.h' file can only be generated correctly after + pnglibconf.h, however the dependency was not in Makefile.am. The + symptoms are unpredictable depending on the order make chooses to + build pngprefix.h and pnglibconf.h, often the error goes unnoticed + because there is a system pnglibconf.h to use instead. + +Version 1.6.0rc07 [February 10, 2013] + Enclosed the new png_get_palette_max in #ifdef PNG_GET_PALETTE_MAX_SUPPORTED + block, and revised pnglibconf.h and pnglibconf.h.prebuilt accordingly. + +Version 1.6.0rc08 [February 10, 2013] + Fix typo in png.h #ifdef + +Version 1.6.0 [February 14, 2013] + No changes. + +Version 1.6.1beta01 [February 16, 2013] + Made symbol prefixing work with the ARM neon optimizations. Also allow + pngpriv.h to be included for preprocessor definitions only, so it can + be used in non-C/C++ files. Back ported from libpng 1.7. + Made sRGB check numbers consistent. + Ported libpng 1.5 options.awk/dfn file handling to 1.6, fixed one bug. + Removed cc -E workround, corrected png_get_palette_max API Tested on + SUN OS cc 5.9, which demonstrates the tokenization problem previously + avoided by using /lib/cpp. Since all .dfn output is now protected in + double quotes unless it is to be macro substituted the fix should + work everywhere. + Enabled parallel tests - back ported from libpng-1.7. + scripts/pnglibconf.dfa formatting improvements back ported from libpng17. + Fixed a race condition in the creation of the build 'scripts' directory + while building with a parallel make. + Use approved/supported Android method to check for NEON, use Linux/POSIX + 1003.1 API to check /proc/self/auxv avoiding buffer allocation and other + library calls (ported from libpng15). + +Version 1.6.1beta02 [February 19, 2013] + Use parentheses more consistently in "#if defined(MACRO)" tests. + Folded long lines. + Reenabled code to allow zero length PLTE chunks for MNG. + +Version 1.6.1beta03 [February 22, 2013] + Fixed ALIGNED_MEMORY support. + Added a new configure option: + --enable-arm-neon=always will stop the run-time checks. New checks + within arm/arm_init.c will cause the code not to be compiled unless + __ARM_NEON__ is set. This should make it fail safe (if someone asks + for it on then the build will fail if it can't be done.) + Updated the INSTALL document. + +Version 1.6.1beta04 [February 27, 2013] + Revised INSTALL to recommend using CPPFLAGS instead of INCLUDES. + Revised scripts/makefile.freebsd to respect ZLIBLIB and ZLIBINC. + Revised scripts/dfn.awk to work with the buggy MSYS awk that has trouble + with CRLF line endings. + +Version 1.6.1beta05 [March 1, 2013] + Avoid a possible memory leak in contrib/gregbook/readpng.c + +Version 1.6.1beta06 [March 4, 2013] + Better documentation of unknown handling API interactions. + Corrected Android builds and corrected libpng.vers with symbol + prefixing. It also makes those tests compile and link on Android. + Added an API png_set_option() to set optimization options externally, + providing an alternative and general solution for the non-portable + run-time tests used by the ARM Neon code, using the PNG_ARM_NEON option. + The order of settings vs options in pnglibconf.h is reversed to allow + settings to depend on options and options can now set (or override) the + defaults for settings. + +Version 1.6.1beta07 [March 7, 2013] + Corrected simplified API default gamma for color-mapped output, added + a flag to change default. In 1.6.0 when the simplified API was used + to produce color-mapped output from an input image with no gamma + information the gamma assumed for the input could be different from + that assumed for non-color-mapped output. In particular 16-bit depth + input files were assumed to be sRGB encoded, whereas in the 'direct' + case they were assumed to have linear data. This was an error. The + fix makes the simplified API treat all input files the same way and + adds a new flag to the png_image::flags member to allow the + application/user to specify that 16-bit files contain sRGB data + rather than the default linear. + Fixed bugs in the pngpixel and makepng test programs. + +Version 1.6.1beta08 [March 7, 2013] + Fixed CMakelists.txt to allow building a single variant of the library + (Claudio Bley): + Introduced a PNG_LIB_TARGETS variable that lists all activated library + targets. It is an error if this variable ends up empty, ie. you have + to build at least one library variant. + Made the *_COPY targets only depend on library targets actually being build. + Use PNG_LIB_TARGETS to unify a code path. + Changed the CREATE_SYMLINK macro to expect the full path to a file as the + first argument. When symlinking the filename component of that path is + determined and used as the link target. + Use copy_if_different in the CREATE_SYMLINK macro. + +Version 1.6.1beta09 [March 13, 2013] + Eliminated two warnings from the Intel C compiler. The warnings are + technically valid, although a reasonable treatment of division would + show it to be incorrect. + +Version 1.6.1rc01 [March 21, 2013] + No changes. + +Version 1.6.1 [March 28, 2013] + No changes. + +Version 1.6.2beta01 [April 14, 2013] + Updated documentation of 1.5.x to 1.6.x changes in iCCP chunk handling. + Fixed incorrect warning of excess deflate data. End condition - the + warning would be produced if the end of the deflate stream wasn't read + in the last row. The warning is harmless. + Corrected the test on user transform changes on read. It was in the + png_set of the transform function, but that doesn't matter unless the + transform function changes the rowbuf size, and that is only valid if + transform_info is called. + Corrected a misplaced closing bracket in contrib/libtests/pngvalid.c + (Flavio Medeiros). + Corrected length written to uncompressed iTXt chunks (Samuli Suominen). + Bug was introduced in libpng-1.6.0. + +Version 1.6.2rc01 [April 18, 2013] + Added contrib/tools/fixitxt.c, to repair the erroneous iTXt chunk length + written by libpng-1.6.0 and 1.6.1. + Disallow storing sRGB information when the sRGB is not supported. + +Version 1.6.2rc02 [April 18, 2013] + Merge pngtest.c with libpng-1.7.0 + +Version 1.6.2rc03 [April 22, 2013] + Trivial spelling cleanup. + +Version 1.6.2rc04 and 1.6.2rc05 [omitted] + +Version 1.6.2rc06 [April 24, 2013] + Reverted to version 1.6.2rc03. Recent changes to arm/neon support + have been ported to libpng-1.7.0beta09 and will reappear in version + 1.6.3beta01. + +Version 1.6.2 [April 25, 2013] + No changes. + +Version 1.6.3beta01 [April 25, 2013] + Revised stack marking in arm/filter_neon.S and configure.ac. + Ensure that NEON filter stuff is completely disabled when switched 'off'. + Previously the ARM NEON specific files were still built if the option + was switched 'off' as opposed to being explicitly disabled. + +Version 1.6.3beta02 [April 26, 2013] + Test for 'arm*' not just 'arm' in the host_cpu configure variable. + Rebuilt the configure scripts. + +Version 1.6.3beta03 [April 30, 2013] + Expanded manual paragraph about writing private chunks, particularly + the need to call png_set_keep_unknown_chunks() when writing them. + Avoid dereferencing NULL pointer possibly returned from + png_create_write_struct() (Andrew Church). + +Version 1.6.3beta05 [May 9, 2013] + Calculate our own zlib windowBits when decoding rather than trusting the + CMF bytes in the PNG datastream. + Added an option to force maximum window size for inflating, which was + the behavior of libpng15 and earlier, via a new PNG_MAXIMUM_INFLATE_WINDOW + option for png_set_options(). + Added png-fix-itxt and png-fix-too-far-back to the built programs and + removed warnings from the source code and timepng that are revealed as + a result. + Detect wrong libpng versions linked to png-fix-too-far-back, which currently + only works with libpng versions that can be made to reliably fail when + the deflate data contains an out-of-window reference. This means only + 1.6 and later. + Fixed gnu issues: g++ needs a static_cast, gcc 4.4.7 has a broken warning + message which it is easier to work round than ignore. + Updated contrib/pngminus/pnm2png.c (Paul Stewart): + Check for EOF + Ignore "#" delimited comments in input file to pnm2png.c. + Fixed whitespace handling + Added a call to png_set_packing() + Initialize dimension values so if sscanf fails at least we have known + invalid values. + Attempt to detect configuration issues with png-fix-too-far-back, which + requires both the correct libpng and the correct zlib to function + correctly. + Check ZLIB_VERNUM for mismatches, enclose #error in quotes + Added information in the documentation about problems with and fixes for + the bad CRC and bad iTXt chunk situations. + +Version 1.6.3beta06 [May 12, 2013] + Allow contrib/pngminus/pnm2png.c to compile without WRITE_INVERT and + WRITE_PACK supported (writes error message that it can't read P1 or + P4 PBM files). + Improved png-fix-too-far-back usage message, added --suffix option. + Revised contrib/pngminim/*/makefile to generate pnglibconf.h with the + right zlib header files. + Separated CPPFLAGS and CFLAGS in contrib/pngminim/*/makefile + +Version 1.6.3beta07 [June 8, 2013] + Removed a redundant test in png_set_IHDR(). + Added set(CMAKE_CONFIGURATION_TYPES ...) to CMakeLists.txt (Andrew Hundt) + Deleted set(CMAKE_BUILD_TYPE) block from CMakeLists.txt + Enclose the prototypes for the simplified write API in + #ifdef PNG_STDIO_SUPPORTED/#endif + Make ARM NEON support work at compile time (not just configure time). + This moves the test on __ARM_NEON__ into pngconf.h to avoid issues when + using a compiler that compiles for multiple architectures at one time. + Removed PNG_FILTER_OPTIMIZATIONS and PNG_ARM_NEON_SUPPORTED from + pnglibconf.h, allowing more of the decisions to be made internally + (pngpriv.h) during the compile. Without this, symbol prefixing is broken + under certain circumstances on ARM platforms. Now only the API parts of + the optimizations ('check' vs 'api') are exposed in the public header files + except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the + decision about whether or not to use the optimizations. + Protect symbol prefixing against CC/CPPFLAGS/CFLAGS usage. + Previous iOS/Xcode fixes for the ARM NEON optimizations moved the test + on __ARM_NEON__ from configure time to compile time. This breaks symbol + prefixing because the definition of the special png_init_filter_functions + call was hidden at configure time if the relevant compiler arguments are + passed in CFLAGS as opposed to CC. This change attempts to avoid all + the confusion that would result by declaring the init function even when + it is not used, so that it will always get prefixed. + +Version 1.6.3beta08 [June 18, 2013] + Revised libpng.3 so that "doclifter" can process it. + +Version 1.6.3beta09 [June 27, 2013] + Revised example.c to illustrate use of PNG_DEFAULT_sRGB and PNG_GAMMA_MAC_18 + as parameters for png_set_gamma(). These have been available since + libpng-1.5.4. + Renamed contrib/tools/png-fix-too-far-back.c to pngfix.c and revised it + to check all compressed chunks known to libpng. + +Version 1.6.3beta10 [July 5, 2013] + Updated documentation to show default behavior of benign errors correctly. + Only compile ARM code when PNG_READ_SUPPORTED is defined. + Fixed undefined behavior in contrib/tools/pngfix.c and added new strip + option. pngfix relied on undefined behavior and even a simple change from + gcc to g++ caused it to fail. The new strip option 'unsafe' has been + implemented and is the default if --max is given. Option names have + been clarified, with --strip=transform now stripping the bKGD chunk, + which was stripped previously with --strip=unused. + Added all documented chunk types to pngpriv.h + Unified pngfix.c source with libpng17. + +Version 1.6.3rc01 [July 11, 2013] + No changes. + +Version 1.6.3 [July 18, 2013] + Revised manual about changes in iTXt chunk handling made in libpng-1.6.0. + Added "/* SAFE */" comments in pngrutil.c and pngrtran.c where warnings + may be erroneously issued by code-checking applications. + +Version 1.6.4beta01 [August 21, 2013] + Added information about png_set_options() to the manual. + Delay calling png_init_filter_functions() until a row with nonzero filter + is found. + +Version 1.6.4beta02 [August 30, 2013] + Fixed inconsistent conditional compilation of png_chunk_unknown_handling() + prototype, definition, and usage. Made it depend on + PNG_HANDLE_AS_UNKNOWN_SUPPORTED everywhere. + +Version 1.6.4rc01 [September 5, 2013] + No changes. + +Version 1.6.4 [September 12, 2013] + No changes. + +Version 1.6.5 [September 14, 2013] + Removed two stray lines of code from arm/arm_init.c. + +Version 1.6.6 [September 16, 2013] + Removed two stray lines of code from arm/arm_init.c, again. + +Version 1.6.7beta01 [September 30, 2013] + Revised unknown chunk code to correct several bugs in the NO_SAVE_/NO_WRITE + combination + Allow HANDLE_AS_UNKNOWN to work when other options are configured off. Also + fixed the pngminim makefiles to work when $(MAKEFLAGS) contains stuff + which terminates the make options (as by default in recent versions of + Gentoo). + Avoid up-cast warnings in pngvalid.c. On ARM the alignment requirements of + png_modifier are greater than that of png_store and as a consequence + compilation of pngvalid.c results in a warning about increased alignment + requirements because of the bare cast to (png_modifier*). The code is safe, + because the pointer is known to point to a stack allocated png_modifier, + but this change avoids the warning. + Fixed default behavior of ARM_NEON_API. If the ARM NEON API option was + compiled without the CHECK option it defaulted to on, not off. + Check user callback behavior in pngunknown.c. Previous versions compiled + if SAVE_UNKNOWN was not available but did nothing since the callback + was never implemented. + Merged pngunknown.c with 1.7 version and back ported 1.7 improvements/fixes + +Version 1.6.7beta02 [October 12, 2013] + Made changes for compatibility with automake 1.14: + 1) Added the 'compile' program to the list of programs that must be cleaned + in autogen.sh + 2) Added 'subdir-objects' which causes .c files in sub-directories to be + compiled such that the corresponding .o files are also in the + sub-directory. This is because automake 1.14 warns that the + current behavior of compiling to the top level directory may be removed + in the future. + 3) Updated dependencies on pnglibconf.h to match the new .o locations and + added all the files in contrib/libtests and contrib/tools that depend + on pnglibconf.h + 4) Added 'BUILD_SOURCES = pnglibconf.h'; this is the automake recommended + way of handling the dependencies of sources that are machine generated; + unfortunately it only works if the user does 'make all' or 'make check', + so the dependencies (3) are still required. + Cleaned up (char*) casts of zlib messages. The latest version of the Intel C + compiler complains about casting a string literal as (char*), so copied the + treatment of z_const from the library code into pngfix.c + Simplified error message code in pngunknown. The simplification has the + useful side effect of avoiding a bogus warning generated by the latest + version of the Intel C compiler (it objects to + condition ? string-literal : string-literal). + Make autogen.sh work with automake 1.13 as well as 1.14. Do this by always + removing the 1.14 'compile' script but never checking for it. + +Version 1.6.7beta03 [October 19, 2013] + Added ARMv8 support (James Yu <james.yu at linaro.org>). Added file + arm/filter_neon_intrinsics.c; enable with -mfpu=neon. + Revised pngvalid to generate size images with as many filters as it can + manage, limited by the number of rows. + Cleaned up ARM NEON compilation handling. The tests are now in pngpriv.h + and detect the broken GCC compilers. + +Version 1.6.7beta04 [October 26, 2013] + Allow clang derived from older GCC versions to use ARM intrinsics. This + causes all clang builds that use -mfpu=neon to use the intrinsics code, + not the assembler code. This has only been tested on iOS 7. It may be + necessary to exclude some earlier clang versions but this seems unlikely. + Changed NEON implementation selection mechanism. This allows assembler + or intrinsics to be turned on at compile time during the build by defining + PNG_ARM_NEON_IMPLEMENTATION to the correct value (2 or 1). This macro + is undefined by default and the build type is selected in pngpriv.h. + +Version 1.6.7rc01 [November 2, 2013] + No changes. + +Version 1.6.7rc02 [November 7, 2013] + Fixed #include in filter_neon_intrinsics.c and ctype macros. The ctype char + checking macros take an unsigned char argument, not a signed char. + +Version 1.6.7 [November 14, 2013] + No changes. + +Version 1.6.8beta01 [November 24, 2013] + Moved prototype for png_handle_unknown() in pngpriv.h outside of + the #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED/#endif block. + Added "-Wall" to CFLAGS in contrib/pngminim/*/makefile + Conditionally compile some unused functions reported by -Wall in + pngminim. + Fixed 'minimal' builds. Various obviously useful minimal configurations + don't build because of missing contrib/libtests test programs and + overly complex dependencies in scripts/pnglibconf.dfa. This change + adds contrib/conftest/*.dfa files that can be used in automatic build + scripts to ensure that these configurations continue to build. + Enabled WRITE_INVERT and WRITE_PACK in contrib/pngminim/encoder. + Fixed pngvalid 'fail' function declaration on the Intel C Compiler. + This reverts to the previous 'static' implementation and works round + the 'unused static function' warning by using PNG_UNUSED(). + +Version 1.6.8beta02 [November 30, 2013] + Removed or marked PNG_UNUSED some harmless "dead assignments" reported + by clang scan-build. + Changed tabs to 3 spaces in png_debug macros and changed '"%s"m' + to '"%s" m' to improve portability among compilers. + Changed png_free_default() to free() in pngtest.c + +Version 1.6.8rc01 [December 12, 2013] + Tidied up pngfix inits and fixed pngtest no-write builds. + +Version 1.6.8rc02 [December 14, 2013] + Handle zero-length PLTE chunk or NULL palette with png_error() + instead of png_chunk_report(), which by default issues a warning + rather than an error, leading to later reading from a NULL pointer + (png_ptr->palette) in png_do_expand_palette(). This is CVE-2013-6954 + and VU#650142. Libpng-1.6.1 through 1.6.7 are vulnerable. + Libpng-1.6.0 and earlier do not have this bug. + +Version 1.6.8 [December 19, 2013] + No changes. + +Version 1.6.9beta01 [December 26, 2013] + Bookkeeping: Moved functions around (no changes). Moved transform + function definitions before the place where they are called so that + they can be made static. Move the intrapixel functions and the + grayscale palette builder out of the png?tran.c files. The latter + isn't a transform function and is no longer used internally, and the + former MNG specific functions are better placed in pngread/pngwrite.c + Made transform implementation functions static. This makes the internal + functions called by png_do_{read|write}_transformations static. On an + x86-64 DLL build (Gentoo Linux) this reduces the size of the text + segment of the DLL by 1208 bytes, about 0.6%. It also simplifies + maintenance by removing the declarations from pngpriv.h and allowing + easier changes to the internal interfaces. + Rebuilt configure scripts with automake-1.14.1 and autoconf-2.69 + in the tar distributions. + +Version 1.6.9beta02 [January 1, 2014] + Added checks for libpng 1.5 to pngvalid.c. This supports the use of + this version of pngvalid in libpng 1.5 + Merged with pngvalid.c from libpng-1.7 changes to create a single + pngvalid.c + Removed #error macro from contrib/tools/pngfix.c (Thomas Klausner). + Merged pngrio.c, pngtrans.c, pngwio.c, and pngerror.c with libpng-1.7.0 + Merged libpng-1.7.0 changes to make no-interlace configurations work + with test programs. + Revised pngvalid.c to support libpng 1.5, which does not support the + PNG_MAXIMUM_INFLATE_WINDOW option, so #define it out when appropriate in + pngvalid.c + Allow unversioned links created on install to be disabled in configure. + In configure builds 'make install' changes/adds links like png.h + and libpng.a to point to the newly installed, versioned, files (e.g. + libpng17/png.h and libpng17.a). Three new configure options and some + rearrangement of Makefile.am allow creation of these links to be disabled. + +Version 1.6.9beta03 [January 10, 2014] + Removed potentially misleading warning from png_check_IHDR(). + +Version 1.6.9beta04 [January 20, 2014] + Updated scripts/makefile.* to use CPPFLAGS (Cosmin). + Added clang attribute support (Cosmin). + +Version 1.6.9rc01 [January 28, 2014] + No changes. + +Version 1.6.9rc02 [January 30, 2014] + Quiet an uninitialized memory warning from VC2013 in png_get_png(). + +Version 1.6.9 [February 6, 2014] + +Version 1.6.10beta01 [February 9, 2014] + Backported changes from libpng-1.7.0beta30 and beta31: + Fixed a large number of instances where PNGCBAPI was omitted from + function definitions. + Added pngimage test program for png_read_png() and png_write_png() + with two new test scripts. + Removed dependence on !PNG_READ_EXPAND_SUPPORTED for calling + png_set_packing() in png_read_png(). + Fixed combination of ~alpha with shift. On read invert alpha, processing + occurred after shift processing, which causes the final values to be + outside the range that should be produced by the shift. Reversing the + order on read makes the two transforms work together correctly and mirrors + the order used on write. + Do not read invalid sBIT chunks. Previously libpng only checked sBIT + values on write, so a malicious PNG writer could therefore cause + the read code to return an invalid sBIT chunk, which might lead to + application errors or crashes. Such chunks are now skipped (with + chunk_benign_error). + Make png_read_png() and png_write_png() prototypes in png.h depend + upon PNG_READ_SUPPORTED and PNG_WRITE_SUPPORTED. + Support builds with unsupported PNG_TRANSFORM_* values. All of the + PNG_TRANSFORM_* values are always defined in png.h and, because they + are used for both read and write in some cases, it is not reliable + to #if out ones that are totally unsupported. This change adds error + detection in png_read_image() and png_write_image() to do a + png_app_error() if the app requests something that cannot be done + and it adds corresponding code to pngimage.c to handle such options + by not attempting to test them. + +Version 1.6.10beta02 [February 23, 2014] + Moved redefines of png_error(), png_warning(), png_chunk_error(), + and png_chunk_warning() from pngpriv.h to png.h to make them visible + to libpng-calling applications. + Moved OS dependent code from arm/arm_init.c, to allow the included + implementation of the ARM NEON discovery function to be set at + build-time and provide sample implementations from the current code in the + contrib/arm-neon subdirectory. The __linux__ code has also been changed to + compile and link on Android by using /proc/cpuinfo, and the old linux code + is in contrib/arm-neon/linux-auxv.c. The new code avoids POSIX and Linux + dependencies apart from opening /proc/cpuinfo and is C90 compliant. + Check for info_ptr == NULL early in png_read_end() so we don't need to + run all the png_handle_*() and depend on them to return if info_ptr == NULL. + This improves the performance of png_read_end(png_ptr, NULL) and makes + it more robust against future programming errors. + Check for __has_extension before using it in pngconf.h, to + support older Clang versions (Jeremy Sequoia). + Treat CRC error handling with png_set_crc_action(), instead of with + png_set_benign_errors(), which has been the case since libpng-1.6.0beta18. + Use a user warning handler in contrib/gregbook/readpng2.c instead of default, + so warnings will be put on stderr even if libpng has CONSOLE_IO disabled. + Added png_ptr->process_mode = PNG_READ_IDAT_MODE in png_push_read_chunk + after recognizing the IDAT chunk, which avoids an infinite loop while + reading a datastream whose first IDAT chunk is of zero-length. + This fixes CERT VU#684412 and CVE-2014-0333. + Don't recognize known sRGB profiles as sRGB if they have been hacked, + but don't reject them and don't issue a copyright violation warning. + +Version 1.6.10beta03 [February 25, 2014] + Moved some documentation from png.h to libpng.3 and libpng-manual.txt + Minor editing of contrib/arm-neon/README and contrib/examples/*.c + +Version 1.6.10rc01 [February 27, 2014] + Fixed typos in the manual and in scripts/pnglibconf.dfa (CFLAGS -> CPPFLAGS + and PNG_USR_CONFIG -> PNG_USER_CONFIG). + +Version 1.6.10rc02 [February 28, 2014] + Removed unreachable return statement after png_chunk_error() + in pngrutil.c + +Version 1.6.10rc03 [March 4, 2014] + Un-deprecated png_data_freer(). + +Version 1.6.10 [March 6, 2014] + No changes. + +Version 1.6.11beta01 [March 17, 2014] + Use "if (value != 0)" instead of "if (value)" consistently. + Changed ZlibSrcDir from 1.2.5 to 1.2.8 in projects/vstudio. + Moved configuration information from the manual to the INSTALL file. + +Version 1.6.11beta02 [April 6, 2014] + Removed #if/#else/#endif from inside two pow() calls in pngvalid.c because + they were handled improperly by Portland Group's PGI-14.1 - PGI-14.3 + when using its "__builtin_pow()" function. + Silence 'unused parameter' build warnings (Cosmin Truta). + $(CP) is now used alongside $(RM_F). Also, use 'copy' instead of 'cp' + where applicable, and applied other minor makefile changes (Cosmin). + Don't warn about invalid dimensions exceeding user limits (Cosmin). + Allow an easy replacement of the default pre-built configuration + header with a custom header, via the make PNGLIBCONF_H_PREBUILT + macro (Cosmin). + +Version 1.6.11beta03 [April 6, 2014] + Fixed a typo in pngrutil.c, introduced in libpng-1.5.6, that interferes + with "blocky" expansion of sub-8-bit interlaced PNG files (Eric Huss). + Optionally use __builtin_bswap16() in png_do_swap(). + +Version 1.6.11beta04 [April 19, 2014] + Made progressive reading of interlaced images consistent with the + behavior of the sequential reader and consistent with the manual, by + moving some code out of the PNG_READ_INTERLACING_SUPPORTED blocks. The + row_callback now receives the proper pass number and unexpanded rows, when + png_combine_row() isn't built or used, and png_set_interlace_handling() + is not called. + Allow PNG_sRGB_PROFILE_CHECKING = (-1) to mean no sRGB profile checking. + +Version 1.6.11beta05 [April 26, 2014] + Do not reject ICC V2 profiles that lack padding (Kai-Uwe Behrmann). + Relocated closing bracket of the sRGB profile test loop to avoid getting + "Not recognizing known sRGB profile that has been edited" warning for + ICC V2 profiles that lack the MD5 signature in the profile header. + +Version 1.6.11beta06 [May 19, 2014] + Added PNG_SKIP_sRGB_CHECK_PROFILE choice for png_set_option(). + +Version 1.6.11rc01 [May 27, 2014] + No changes. + +Version 1.6.11rc02 [June 3, 2014] + Test ZLIB_VERNUM instead of PNG_ZLIB_VERNUM in contrib/tools/pngfix.c + +Version 1.6.11 [June 5, 2014] + No changes. + +Version 1.6.12rc01 [June 6, 2014] + Relocated new code from 1.6.11beta06 in png.c to a point after the + declarations (Max Stepin). + +Version 1.6.12rc02 [June 7, 2014] + Changed file permissions of contrib/tools/intgamma.sh, + test-driver, and compile from 0644 to 0755 (Cosmin). + +Version 1.6.12rc03 [June 8, 2014] + Ensure "__has_attribute()" macro exists before trying to use it with + old clang compilers (MacPorts Ticket #43939). + +Version 1.6.12 [June 12, 2014] + No changes. + +Version 1.6.13beta01 [July 4, 2014] + Quieted -Wsign-compare and -Wclobber compiler warnings in + contrib/pngminus/*.c + Added "(void) png_ptr;" where needed in contrib/gregbook to quiet + compiler complaints about unused pointers. + Split a long output string in contrib/gregbook/rpng2-x.c. + Added "PNG_SET_OPTION" requirement for sRGB chunk support to pnglibconf.dfa, + Needed for write-only support (John Bowler). + Changed "if defined(__ARM_NEON__)" to + "if (defined(__ARM_NEON__) || defined(__ARM_NEON))" (James Wu). + Fixed clang no-warning builds: png_digit was defined but never used. + +Version 1.6.13beta02 [July 21, 2014] + Fixed an incorrect separator ("/" should be "\") in scripts/makefile.vcwin32 + (bug report from Wolfgang S. Kechel). Bug was introduced in libpng-1.6.11. + Also fixed makefile.bc32, makefile.bor, makefile.msc, makefile.intel, and + makefile.tc3 similarly. + +Version 1.6.13beta03 [August 3, 2014] + Removed scripts/makefile.elf. It has not worked since libpng-1.5.0beta14 + due to elimination of the PNG_FUNCTION_EXPORT and PNG_DATA_EXPORT + definitions from pngconf.h. + Ensure that CMakeLists.txt makes the target "lib" directory before making + symbolic link into it (SourceForge bug report #226 by Rolf Timmermans). + +Version 1.6.13beta04 [August 8, 2014] + Added opinion that the ECCN (Export Control Classification Number) for + libpng is EAR99 to the README file. + Eliminated use of "$<" in makefile explicit rules, when copying + $PNGLIBCONF_H_PREBUILT. This does not work on some versions of make; + bug introduced in libpng version 1.6.11. + +Version 1.6.13rc01 [August 14, 2014] + Made "ccopts" agree with "CFLAGS" in scripts/makefile.hp* and makefile.*sunu + +Version 1.6.13 [August 21, 2014] + No changes. + +Version 1.6.14beta01 [September 14, 2014] + Guard usage of png_ptr->options with #ifdef PNG_SET_OPTION_SUPPORTED. + Do not build contrib/tools/pngfix.c when PNG_SETJMP_NOT_SUPPORTED, + to allow "make" to complete without setjmp support (bug report by + Claudio Fontana) + Add "#include <setjmp.h>" to contrib/tools/pngfix.c (John Bowler) + +Version 1.6.14beta02 [September 18, 2014] + Use nanosleep() instead of usleep() in contrib/gregbook/rpng2-x.c + because usleep() is deprecated. + Define usleep() in contrib/gregbook/rpng2-x.c if not already defined + in unistd.h and nanosleep() is not available; fixes error introduced + in libpng-1.6.13. + Disable floating point exception handling in pngvalid.c when + PNG_FLOATING_ARITHMETIC is not supported (bug report by "zootus + at users.sourceforge.net"). + +Version 1.6.14beta03 [September 19, 2014] + Define FE_DIVBYZERO, FE_INVALID, and FE_OVERFLOW in pngvalid.c if not + already defined. Revert floating point exception handling in pngvalid.c + to version 1.6.14beta01 behavior. + +Version 1.6.14beta04 [September 27, 2014] + Fixed incorrect handling of the iTXt compression flag in pngrutil.c + (bug report by Shunsaku Hirata). Bug was introduced in libpng-1.6.0. + +Version 1.6.14beta05 [October 1, 2014] + Added "option READ_iCCP enables READ_COMPRESSED_TEXT" to pnglibconf.dfa + +Version 1.6.14beta06 [October 5, 2014] + Removed unused "text_len" parameter from private function png_write_zTXt(). + Conditionally compile some code in png_deflate_claim(), when + PNG_WARNINGS_SUPPORTED and PNG_ERROR_TEXT_SUPPORTED are disabled. + Replaced repeated code in pngpread.c with PNG_PUSH_SAVE_BUFFER_IF_FULL. + Added "chunk iTXt enables TEXT" and "chunk zTXt enables TEXT" + to pnglibconf.dfa. + Removed "option READ_COMPRESSED_TEXT enables READ_TEXT" from pnglibconf.dfa, + to make it possible to configure a libpng that supports iCCP but not TEXT. + +Version 1.6.14beta07 [October 7, 2014] + Removed "option WRITE_COMPRESSED_TEXT enables WRITE_TEXT" from pnglibconf.dfa + Only mark text chunks as written after successfully writing them. + +Version 1.6.14rc01 [October 15, 2014] + Fixed some typos in comments. + +Version 1.6.14rc02 [October 17, 2014] + Changed png_convert_to_rfc_1123() to png_convert_to_rfc_1123_buffer() + in the manual, to reflect the change made in libpng-1.6.0. + Updated README file to explain that direct access to the png_struct + and info_struct members has not been permitted since libpng-1.5.0. + +Version 1.6.14 [October 23, 2014] + No changes. + +Version 1.6.15beta01 [October 29, 2014] + Changed "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)" + Simplified png_free_data(). + Added missing "ptr = NULL" after some instances of png_free(). + +Version 1.6.15beta02 [November 1, 2014] + Changed remaining "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)" + +Version 1.6.15beta03 [November 3, 2014] + Added PNG_USE_ARM_NEON configuration flag (Marcin Juszkiewicz). + +Version 1.6.15beta04 [November 4, 2014] + Removed new PNG_USE_ARM_NEON configuration flag and made a one-line + revision to configure.ac to support ARM on aarch64 instead (John Bowler). + +Version 1.6.15beta05 [November 5, 2014] + Use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING in + example.c, pngtest.c, and applications in the contrib directory. + Fixed an out-of-range read in png_user_version_check() (Bug report from + Qixue Xiao, CVE-2015-8540). + Simplified and future-proofed png_user_version_check(). + Fixed GCC unsigned int->float warnings. Various versions of GCC + seem to generate warnings when an unsigned value is implicitly + converted to double. This is probably a GCC bug but this change + avoids the issue by explicitly converting to (int) where safe. + Free all allocated memory in pngimage. The file buffer cache was left + allocated at the end of the program, harmless but it causes memory + leak reports from clang. + Fixed array size calculations to avoid warnings. At various points + in the code the number of elements in an array is calculated using + sizeof. This generates a compile time constant of type (size_t) which + is then typically assigned to an (unsigned int) or (int). Some versions + of GCC on 64-bit systems warn about the apparent narrowing, even though + the same compiler does apparently generate the correct, in-range, + numeric constant. This adds appropriate, safe, casts to make the + warnings go away. + +Version 1.6.15beta06 [November 6, 2014] + Reverted use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING + in the manual, example.c, pngtest.c, and applications in the contrib + directory. It was incorrect advice. + +Version 1.6.15beta07 [November 7, 2014] + Removed #ifdef PNG_16BIT_SUPPORTED/#endif around png_product2(); it is + needed by png_reciprocal2(). + Added #ifdef PNG_16BIT_SUPPORTED/#endif around png_log16bit() and + png_do_swap(). + Changed all "#endif /* PNG_FEATURE_SUPPORTED */" to "#endif /* FEATURE */" + +Version 1.6.15beta08 [November 8, 2014] + More housecleaning in *.h + +Version 1.6.15rc01 [November 13, 2014] + +Version 1.6.15rc02 [November 14, 2014] + The macros passed in the command line to Borland make were ignored if + similarly-named macros were already defined in makefiles. This behavior + is different from POSIX make and other make programs. Surround the + macro definitions with ifndef guards (Cosmin). + +Version 1.6.15rc03 [November 16, 2014] + Added "-D_CRT_SECURE_NO_WARNINGS" to CFLAGS in scripts/makefile.vcwin32. + Removed the obsolete $ARCH variable from scripts/makefile.darwin. + +Version 1.6.15 [November 20, 2014] + No changes. + +Version 1.6.16beta01 [December 14, 2014] + Added ".align 2" to arm/filter_neon.S to support old GAS assemblers that + don't do alignment correctly. + Revised Makefile.am and scripts/symbols.dfn to work with MinGW/MSYS + (Bob Friesenhahn). + +Version 1.6.16beta02 [December 15, 2014] + Revised Makefile.am and scripts/*.dfn again to work with MinGW/MSYS; + renamed scripts/*.dfn to scripts/*.c (John Bowler). + +Version 1.6.16beta03 [December 21, 2014] + Quiet a "comparison always true" warning in pngstest.c (John Bowler). + +Version 1.6.16rc01 [December 21, 2014] + Restored a test on width that was removed from png.c at libpng-1.6.9 + (Bug report by Alex Eubanks, CVE-2015-0973). + +Version 1.6.16rc02 [December 21, 2014] + Undid the update to pngrutil.c in 1.6.16rc01. + +Version 1.6.16rc03 [December 21, 2014] + Fixed an overflow in png_combine_row() with very wide interlaced images + (Bug report and fix by John Bowler, CVE-2014-9495). + +Version 1.6.16 [December 22, 2014] + No changes. + +Version 1.6.17beta01 [January 29, 2015] + Removed duplicate PNG_SAFE_LIMITS_SUPPORTED handling from pngconf.h + Corrected the width limit calculation in png_check_IHDR(). + Removed user limits from pngfix. Also pass NULL pointers to + png_read_row to skip the unnecessary row de-interlace stuff. + Added testing of png_set_packing() to pngvalid.c + Regenerated configure scripts in the *.tar distributions with libtool-2.4.4 + Implement previously untested cases of libpng transforms in pngvalid.c + Fixed byte order in png_do_read_filler() with 16-bit input. Previously + the high and low bytes of the filler, from png_set_filler() or from + png_set_add_alpha(), were read in the wrong order. + Made the check for out-of-range values in png_set_tRNS() detect + values that are exactly 2^bit_depth, and work on 16-bit platforms. + Merged some parts of libpng-1.6.17beta01 and libpng-1.7.0beta47. + Added #ifndef __COVERITY__ where needed in png.c, pngrutil.c and + pngset.c to avoid warnings about dead code. + Added "& 0xff" to many instances of expressions that are typecast + to (png_byte), to avoid Coverity warnings. + +Version 1.6.17beta02 [February 7, 2015] + Work around one more Coverity-scan dead-code warning. + Do not build png_product2() when it is unused. + +Version 1.6.17beta03 [February 17, 2015] + Display user limits in the output from pngtest. + Eliminated the PNG_SAFE_LIMITS macro and restored the 1-million-column + and 1-million-row default limits in pnglibconf.dfa, that can be reset + by the user at build time or run time. This provides a more robust + defense against DOS and as-yet undiscovered overflows. + +Version 1.6.17beta04 [February 21, 2015] + Added PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED macro, on by default. + Allow user to call png_get_IHDR() with NULL arguments (Reuben Hawkins). + Rebuilt configure scripts with automake-1.15 and libtool-2.4.6 + +Version 1.6.17beta05 [February 25, 2015] + Restored compiling of png_reciprocal2 with PNG_NO_16BIT. + +Version 1.6.17beta06 [February 27, 2015] + Moved png_set_filter() prototype into a PNG_WRITE_SUPPORTED block + of png.h. + Avoid runtime checks when converting integer to png_byte with + Visual Studio (Sergey Kosarevsky) + +Version 1.6.17rc01 [March 4, 2015] + No changes. + +Version 1.6.17rc02 [March 9, 2015] + Removed some comments that the configure script did not handle + properly from scripts/pnglibconf.dfa and pnglibconf.h.prebuilt. + Free the unknown_chunks structure even when it contains no data. + +Version 1.6.17rc03 [March 12, 2015] + Updated CMakeLists.txt to add OSX framework, change YES/NO to ON/OFF + for consistency, and remove some useless tests (Alexey Petruchik). + +Version 1.6.17rc04 [March 16, 2015] + Remove pnglibconf.h, pnglibconf.c, and pnglibconf.out instead of + pnglibconf.* in "make clean" (Cosmin). + Fix bug in calculation of maxbits, in png_write_sBIT, introduced + in libpng-1.6.17beta01 (John Bowler). + +Version 1.6.17rc05 [March 21, 2015] + Define PNG_FILTER_* and PNG_FILTER_VALUE_* in png.h even when WRITE + is not supported (John Bowler). This fixes an error introduced in + libpng-1.6.17beta06. + Reverted "& 0xff" additions of version 1.6.17beta01. Libpng passes + the Coverity scan without them. + +Version 1.6.17rc06 [March 23, 2015] + Remove pnglibconf.dfn and pnglibconf.pre with "make clean". + Reformatted some "&0xff" instances to "& 0xff". + Fixed simplified 8-bit-linear to sRGB alpha. The calculated alpha + value was wrong. It's not clear if this affected the final stored + value; in the obvious code path the upper and lower 8-bits of the + alpha value were identical and the alpha was truncated to 8-bits + rather than dividing by 257 (John Bowler). + +Version 1.6.17 [March 26, 2015] + No changes. + +Version 1.6.18beta01 [April 1, 2015] + Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros. They + have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves + bug report by Andrew Church). + Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c. This + fixes some arithmetic errors that caused some tests to fail on + some 32-bit platforms (Bug reports by Peter Breitenlohner [i686] + and Petr Gajdos [i586]). + +Version 1.6.18beta02 [April 26, 2015] + Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler + (Bug report by Viktor Szakats). + +Version 1.6.18beta03 [May 6, 2015] + Replaced "unexpected" with an integer (0xabadca11) in pngset.c + where a long was expected, to avoid a compiler warning when PNG_DEBUG > 1. + Added contrib/examples/simpleover.c, to demonstrate how to handle + alpha compositing of multiple images, using the "simplified API" + and an example PNG generation tool, contrib/examples/genpng.c + (John Bowler). + +Version 1.6.18beta04 [May 20, 2015] + PNG_RELEASE_BUILD replaces tests where the code depended on the build base + type and can be defined on the command line, allowing testing in beta + builds (John Bowler). + Avoid Coverity issue 80858 (REVERSE NULL) in pngtest.c PNG_DEBUG builds. + Avoid a harmless potential integer overflow in png_XYZ_from_xy() (Bug + report from Christopher Ferris). + +Version 1.6.18beta05 [May 31, 2015] + Backport filter selection code from libpng-1.7.0beta51, to combine + sub_row, up_row, avg_row, and paeth_row into try_row and tst_row. + Changed png_voidcast(), etc., to voidcast(), etc., in contrib/tools/pngfix.c + to avoid confusion with the libpng private macros. + Fixed old cut&paste bug in the weighted filter selection code in + pngwutil.c, introduced in libpng-0.95, March 1997. + +Version 1.6.18beta06 [June 1, 2015] + Removed WRITE_WEIGHTED_FILTERED code, to save a few kbytes of the + compiled library size. It never worked properly and as far as we can + tell, no one uses it. The png_set_filter_heuristics() and + png_set_filter_heuristics_fixed() APIs are retained but deprecated + and do nothing. + +Version 1.6.18beta07 [June 6, 2015] + Removed non-working progressive reader 'skip' function. This + function has apparently never been used. It was implemented + to support back-door modification of png_struct in libpng-1.4.x + but (because it does nothing and cannot do anything) was apparently + never tested (John Bowler). + Fixed cexcept.h in which GCC 5 now reports that one of the auto + variables in the Try macro needs to be volatile to prevent value + being lost over the setjmp (John Bowler). + Fixed NO_WRITE_FILTER and -Wconversion build breaks (John Bowler). + Fix g++ build breaks (John Bowler). + Quieted some Coverity issues in pngfix.c, png-fix-itxt.c, pngvalid.c, + pngstest.c, and pngimage.c. Most seem harmless, but png-fix-itxt + would only work with iTXt chunks with length 255 or less. + Added #ifdef's to contrib/examples programs so people don't try + to compile them without the minimum required support enabled + (suggested by Flavio Medeiros). + +Version 1.6.18beta08 [June 30, 2015] + Eliminated the final two Coverity defects (insecure temporary file + handling in contrib/libtests/pngstest.c; possible overflow of + unsigned char in contrib/tools/png-fix-itxt.c). To use the "secure" + file handling, define PNG_USE_MKSTEMP, otherwise "tmpfile()" will + be used. + Removed some unused WEIGHTED_FILTER macros from png.h and pngstruct.h + +Version 1.6.18beta09 [July 5, 2015] + Removed some useless typecasts from contrib/tools/png-fix-itxt.c + Fixed a new signed-unsigned comparison in pngrtran.c (Max Stepin). + Replaced arbitrary use of 'extern' with #define PNG_LINKAGE_*. To + preserve API compatibility, the new defines all default to "extern" + (requested by Jan Nijtmans). + +Version 1.6.18rc01 [July 9, 2015] + Belatedly added Mans Rullgard and James Yu to the list of Contributing + Authors. + +Version 1.6.18rc02 [July 12, 2015] + Restored unused FILTER_HEURISTIC macros removed at libpng-1.6.18beta08 + to png.h to avoid compatibility warnings. + +Version 1.6.18rc03 [July 15, 2015] + Minor changes to the man page + +Version 1.6.18 [July 23, 2015] + No changes. + +Version 1.6.19beta01 [July 30, 2015] + Updated obsolete information about the simplified API macros in the + manual pages (Bug report by Arc Riley). + Avoid potentially dereferencing NULL info_ptr in png_info_init_3(). + Rearranged png.h to put the major sections in the same order as + in libpng17. + Eliminated unused PNG_COST_SHIFT, PNG_WEIGHT_SHIFT, PNG_COST_FACTOR, and + PNG_WEIGHT_FACTOR macros. + Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler + (Bug report by Viktor Szakats). Several warnings remain and are + unavoidable, where we test for overflow. + Fixed potential leak of png_pixels in contrib/pngminus/pnm2png.c + Fixed uninitialized variable in contrib/gregbook/rpng2-x.c + +Version 1.6.19beta02 [August 19, 2015] + Moved config.h.in~ from the "libpng_autotools_files" list to the + "libpng_autotools_extra" list in autogen.sh because it was causing a + false positive for missing files (bug report by Robert C. Seacord). + Removed unreachable "break" statements in png.c, pngread.c, and pngrtran.c + to suppress clang warnings (Bug report by Viktor Szakats). + Fixed some bad links in the man page. + Changed "n bit" to "n-bit" in comments. + Added signed/unsigned 16-bit safety net. This removes the dubious + 0x8000 flag definitions on 16-bit systems. They aren't supported + yet the defs *probably* work, however it seems much safer to do this + and be advised if anyone, contrary to advice, is building libpng 1.6 + on a 16-bit system. It also adds back various switch default clauses + for GCC; GCC errors out if they are not present (with an appropriately + high level of warnings). + Safely convert num_bytes to a png_byte in png_set_sig_bytes() (Robert + Seacord). + Fixed the recently reported 1's complement security issue by replacing + the value that is illegal in the PNG spec, in both signed and unsigned + values, with 0. Illegal unsigned values (anything greater than or equal + to 0x80000000) can still pass through, but since these are not illegal + in ANSI-C (unlike 0x80000000 in the signed case) the checking that + occurs later can catch them (John Bowler). + +Version 1.6.19beta03 [September 26, 2015] + Fixed png_save_int_32 when int is not 2's complement (John Bowler). + Updated libpng16 with all the recent test changes from libpng17, + including changes to pngvalid.c to ensure that the original, + distributed, version of contrib/visupng/cexcept.h can be used + (John Bowler). + pngvalid contains the correction to the use of SAVE/STORE_ + UNKNOWN_CHUNKS; a bug revealed by changes in libpng 1.7. More + tests contain the --strict option to detect warnings and the + pngvalid-standard test has been corrected so that it does not + turn on progressive-read. There is a separate test which does + that. (John Bowler) + Also made some signed/unsigned fixes. + Make pngstest error limits version specific. Splitting the machine + generated error structs out to a file allows the values to be updated + without changing pngstest.c itself. Since libpng 1.6 and 1.7 have + slightly different error limits this simplifies maintenance. The + makepngs.sh script has also been updated to more accurately reflect + current problems in libpng 1.7 (John Bowler). + Incorporated new test PNG files into make check. tests/pngstest-* + are changed so that the new test files are divided into 8 groups by + gamma and alpha channel. These tests have considerably better code + and pixel-value coverage than contrib/pngsuite; however,coverage is + still incomplete (John Bowler). + Removed the '--strict' in 1.6 because of the double-gamma-correction + warning, updated pngstest-errors.h for the errors detected with the + new contrib/testspngs PNG test files (John Bowler). + +Version 1.6.19beta04 [October 15, 2015] + Worked around rgb-to-gray issues in libpng 1.6. The previous + attempts to ignore the errors in the code aren't quite enough to + deal with the 'channel selection' encoding added to libpng 1.7; abort. + pngvalid.c is changed to drop this encoding in prior versions. + Fixed 'pow' macros in pngvalid.c. It is legal for 'pow' to be a + macro, therefore the argument list cannot contain preprocessing + directives. Make sure pow is a function where this happens. This is + a minimal safe fix, the issue only arises in non-performance-critical + code (bug report by Curtis Leach, fix by John Bowler). + Added sPLT support to pngtest.c + +Version 1.6.19rc01 [October 23, 2015] + No changes. + +Version 1.6.19rc02 [October 31, 2015] + Prevent setting or writing over-length PLTE chunk (Cosmin Truta). + Silently truncate over-length PLTE chunk while reading. + Libpng incorrectly calculated the output rowbytes when the application + decreased either the number of channels or the bit depth (or both) in + a user transform. This was safe; libpng overallocated buffer space + (potentially by quite a lot; up to 4 times the amount required) but, + from 1.5.4 on, resulted in a png_error (John Bowler). + +Version 1.6.19rc03 [November 3, 2015] + Fixed some inconsequential cut-and-paste typos in png_set_cHRM_XYZ_fixed(). + Clarified COPYRIGHT information to state explicitly that versions + are derived from previous versions. + Removed much of the long list of previous versions from png.h and + libpng.3. + +Version 1.6.19rc04 [November 5, 2015] + Fixed new bug with CRC error after reading an over-length palette + (bug report by Cosmin Truta) (CVE-2015-8126). + +Version 1.6.19 [November 12, 2015] + Cleaned up coding style in png_handle_PLTE(). + +Version 1.6.20beta01 [November 20, 2015] + Avoid potential pointer overflow/underflow in png_handle_sPLT() and + png_handle_pCAL() (Bug report by John Regehr). + +Version 1.6.20beta02 [November 23, 2015] + Fixed incorrect implementation of png_set_PLTE() that uses png_ptr + not info_ptr, that left png_set_PLTE() open to the CVE-2015-8126 + vulnerability. Fixes CVE-2015-8472. + +Version 1.6.20beta03 [November 24, 2015] + Backported tests from libpng-1.7.0beta69. + +Version 1.6.20rc01 [November 26, 2015] + Fixed an error in handling of bad zlib CMINFO field in pngfix, found by + American Fuzzy Lop, reported by Brian Carpenter. inflate() doesn't + immediately fault a bad CMINFO field; instead a 'too far back' error + happens later (at least some times). pngfix failed to limit CMINFO to + the allowed values but then assumed that window_bits was in range, + triggering an assert. The bug is mostly harmless; the PNG file cannot + be fixed. + +Version 1.6.20rc02 [November 29, 2015] + In libpng 1.6 zlib initialization was changed to use the window size + in the zlib stream, not a fixed value. This causes some invalid images, + where CINFO is too large, to display 'correctly' if the rest of the + data is valid. This provides a workaround for zlib versions where the + error arises (ones that support the API change to use the window size + in the stream). + +Version 1.6.20 [December 3, 2015] + No changes. + +Version 1.6.21beta01 [December 11, 2015] + Fixed syntax "$(command)" in tests/pngstest that some shells other than + bash could not parse (Bug report by Nelson Beebe). Use `command` instead. + +Version 1.6.21beta02 [December 14, 2015] + Moved png_check_keyword() from pngwutil.c to pngset.c + Removed LE/BE dependencies in pngvalid, to 'fix' the current problem + in the BigEndian tests by not testing it, making the BE code the same + as the LE version. + Fixes to pngvalid for various reduced build configurations (eliminate unused + statics) and a fix for the case in rgb_to_gray when the digitize option + reduces graylo to 0, producing a large error. + +Version 1.6.21beta03 [December 18, 2015] + Widened the 'limit' check on the internally calculated error limits in + the 'DIGITIZE' case (the code used prior to 1.7 for rgb_to_gray error + checks) and changed the check to only operate in non-release builds + (base build type not RC or RELEASE.) + Fixed undefined behavior in pngvalid.c, undefined because + (png_byte) << shift is undefined if it changes the signed bit + (because png_byte is promoted to int). The libpng exported functions + png_get_uint_32 and png_get_uint_16 handle this. (Bug reported by + David Drysdale as a result of reports from UBSAN in clang 3.8). + This changes pngvalid to use BE random numbers; this used to produce + errors but these should not be fixed as a result of the previous changes. + +Version 1.6.21rc01 [January 4, 2016] + In projects/vstudio, combined readme.txt and WARNING into README.txt + +Version 1.6.21rc02 [January 7, 2016] + Relocated assert() in contrib/tools/pngfix.c, bug found by American + Fuzzy Lop, reported by Brian Carpenter. + Marked 'limit' UNUSED in transform_range_check(). This only affects + release builds. + +Version 1.6.21 [January 15, 2016] + Worked around a false-positive Coverity issue in pngvalid.c. + +Version 1.6.22beta01 [January 23, 2016] + Changed PNG_USE_MKSTEMP to __COVERITY__ to select alternate + "tmpfile()" implementation in contrib/libtests/pngstest.c + Fixed NO_STDIO build of pngunknown.c to skip calling png_init_io() + if there is no stdio.h support. + Added a png_image_write_to_memory() API and a number of assist macros + to allow an application that uses the simplified API write to bypass + stdio and write directly to memory. + Added some warnings (png.h) and some check code to detect *possible* + overflow in the ROW_STRIDE and simplified image SIZE macros. This + disallows image width/height/format that *might* overflow. This is + a quiet API change that limits in-memory image size (uncompressed) to + less than 4GByte and image row size (stride) to less than 2GByte. + Revised workaround for false-positive Coverity issue in pngvalid.c. + +Version 1.6.22beta02 [February 8, 2016] + Only use exit(77) in configure builds. + Corrected error in PNG_IMAGE_PNG_SIZE_MAX. This new macro underreported + the palette size because it failed to take into account that the memory + palette has to be expanded to full RGB when it is written to PNG. + Updated CMakeLists.txt, added supporting scripts/gen*.cmake.in + and test.cmake.in (Roger Leigh). + Relaxed limit checks on gamma values in pngrtran.c. As suggested in + the comments gamma values outside the range currently permitted + by png_set_alpha_mode are useful for HDR data encoding. These values + are already permitted by png_set_gamma so it is reasonable caution to + extend the png_set_alpha_mode range as HDR imaging systems are starting + to emerge. + +Version 1.6.22beta03 [March 9, 2016] + Added a common-law trademark notice and export control information + to the LICENSE file, png.h, and the man page. + Restored "& 0xff" in png_save_uint_16() and png_save_uint_32() that + were accidentally removed from libpng-1.6.17. + Changed PNG_INFO_cHNK and PNG_FREE_cHNK from 0xnnnn to 0xnnnnU in png.h + (Robert C. Seacord). + Removed dubious "#if INT_MAX" test from png.h that was added to + libpng-1.6.19beta02 (John Bowler). + Add ${INCLUDES} in scripts/genout.cmake.in (Bug report by Nixon Kwok). + Updated LICENSE to say files in the contrib directory are not + necessarily under the libpng license, and that some makefiles have + other copyright owners. + Added INTEL-SSE2 support (Mike Klein and Matt Sarett, Google, Inc.). + Made contrib/libtests/timepng more robust. The code no longer gives + up/fails on invalid PNG data, it just skips it (with error messages). + The code no longer fails on PNG files with data beyond IEND. Options + exist to use png_read_png (reading the whole image, not by row) and, in + that case, to apply any of the supported transforms. This makes for + more realistic testing; the decoded data actually gets used in a + meaningful fashion (John Bowler). + Fixed some misleading indentation (Krishnaraj Bhat). + +Version 1.6.22beta04 [April 5, 2016] + Force GCC compilation to C89 if needed (Dagobert Michelsen). + SSE filter speed improvements for bpp=3: + memcpy-free implementations of load3() / store3(). + call load3() only when needed at the end of a scanline. + +Version 1.6.22beta05 [April 27, 2016] + Added PNG_FAST_FILTERS macro (defined as + PNG_FILTER_NONE|PNG_FILTER_SUB|PNG_FILTER_UP). + Various fixes for contrib/libtests/timepng.c + Moved INTEL-SSE code from pngpriv.h into contrib/intel/intel_sse.patch. + Fixed typo (missing underscore) in #define PNG_READ_16_TO_8_SUPPORTED + (Bug report by Y.Ohashik). + +Version 1.6.22beta06 [May 5, 2016] + Rebased contrib/intel_sse.patch. + Quieted two Coverity issues in contrib/libtests/timepng.c. + Fixed issues with scripts/genout.cmake.in (David Capello, Nixon Kwok): + Added support to use multiple directories in ZLIBINCDIR variable, + Fixed CMAKE_C_FLAGS with multiple values when genout is compiled on MSVC, + Fixed pnglibconf.c compilation on OS X including the sysroot path. + +Version 1.6.22rc01 [May 14, 2016] + No changes. + +Version 1.6.22rc02 [May 16, 2016] + Removed contrib/timepng from default build; it does not build on platforms + that don't supply clock_gettime(). + +Version 1.6.22rc03 [May 17, 2016] + Restored contrib/timepng to default build but check for the presence + of clock_gettime() in configure.ac and Makefile.am. + +Version 1.6.22 [May 26, 2016] + No changes. + +Version 1.6.23beta01 [May 29, 2016] + Stop a potential memory leak in png_set_tRNS() (Bug report by Ted Ying). + Fixed the progressive reader to handle empty first IDAT chunk properly + (patch by Timothy Nikkel). This bug was introduced in libpng-1.6.0 and + only affected the libpng16 branch. + Added tests in pngvalid.c to check zero-length IDAT chunks in various + positions. Fixed the sequential reader to handle these more robustly + (John Bowler). + +Version 1.6.23rc01 [June 2, 2016] + Corrected progressive read input buffer in pngvalid.c. The previous version + the code invariably passed just one byte at a time to libpng. The intent + was to pass a random number of bytes in the range 0..511. + Moved sse2 prototype from pngpriv.h to contrib/intel/intel_sse.patch. + Added missing ")" in pngerror.c (Matt Sarrett). + +Version 1.6.23rc02 [June 4, 2016] + Fixed undefined behavior in png_push_save_buffer(). Do not call + memcpy() with a null source, even if count is zero (Leon Scroggins III). + +Version 1.6.23 [June 9, 2016] + Fixed bad link to RFC2083 in png.5 (Nikola Forro). + +Version 1.6.24beta01 [June 11, 2016] + Avoid potential overflow of the PNG_IMAGE_SIZE macro. This macro + is not used within libpng, but is used in some of the examples. + +Version 1.6.24beta02 [June 23, 2016] + Correct filter heuristic overflow handling. This was broken when the + write filter code was moved out-of-line; if there is a single filter and + the heuristic sum overflows the calculation of the filtered line is not + completed. In versions prior to 1.6 the code was duplicated in-line + and the check not performed, so the filter operation completed; however, + in the multi-filter case where the sum is performed the 'none' filter would + be selected if all the sums overflowed, even if it wasn't in the filter + list. The fix to the first problem is simply to provide PNG_SIZE_MAX as + the current lmins sum value; this means the sum can never exceed it and + overflows silently. A reasonable compiler that does choose to inline + the code will simply eliminate the sum check. + The fix to the second problem is to use high precision arithmetic (this is + implemented in 1.7), however a simple safe fix here is to chose the lowest + numbered filter in the list from png_set_filter (this only works if the + first problem is also fixed) (John Bowler). + Use a more efficient absolute value calculation on SSE2 (Matthieu Darbois). + Fixed the case where PNG_IMAGE_BUFFER_SIZE can overflow in the application + as a result of the application using an increased 'row_stride'; previously + png_image_finish_read only checked for overflow on the base calculation of + components. (I.e. it checked for overflow of a 32-bit number on the total + number of pixel components in the output format, not the possibly padded row + length and not the number of bytes, which for linear formats is twice the + number of components.) + MSVC does not like '-(unsigned)', so replaced it with 0U-(unsigned) + MSVC does not like (uInt) = -(unsigned) (i.e. as an initializer), unless + the conversion is explicitly invoked by a cast. + Put the SKIP definition in the correct place. It needs to come after the + png.h include (see all the other .c files in contrib/libtests) because it + depends on PNG_LIBPNG_VER. + Removed the three compile warning options from the individual project + files into the zlib.props globals. It increases the warning level from 4 + to All and adds a list of the warnings that need to be turned off. This is + semi-documentary; the intent is to tell libpng users which warnings have + been examined and judged non-fixable at present. The warning about + structure padding is fixable, but it would be a significant change (moving + structure members around). + +Version 1.6.24beta03 [July 4, 2016] + Optimized absolute value calculation in filter selection, similar to + code in the PAETH decoder in pngrutil.c. Build with PNG_USE_ABS to + use this. + Added pngcp to the build together with a pngcp.dfa configuration test. + Added high resolution timing to pngcp. + Added "Common linking failures" section to INSTALL. + Relocated misplaced #endif in png.c sRGB profile checking. + Fixed two Coverity issues in pngcp.c. + +Version 1.6.24beta04 [July 8, 2016] + Avoid filter-selection heuristic sum calculations in cases where only one + filter is a candidate for selection. This trades off code size (added + private png_setup_*_row_only() functions) for speed. + +Version 1.6.24beta05 [July 13, 2016] + Fixed some indentation to comply with our coding style. + Added contrib/tools/reindent. + +Version 1.6.24beta06 [July 18, 2016] + Fixed more indentation to comply with our coding style. + Eliminated unnecessary tests of boolean png_isaligned() vs 0. + +Version 1.6.24rc01 [July 25, 2016] + No changes. + +Version 1.6.24rc02 [August 1, 2016] + Conditionally compile SSE2 headers in contrib/intel/intel_sse.patch + Conditionally compile png_decompress_chunk(). + +Version 1.6.24rc03 [August 2, 2016] + Conditionally compile ARM_NEON headers in pngpriv.h + Updated contrib/intel/intel_sse.patch + +Version 1.6.24[August 4, 2016] + No changes. + +Version 1.6.25beta01 [August 12, 2016] + Reject oversized iCCP profile immediately. + Cleaned up PNG_DEBUG compile of pngtest.c. + Conditionally compile png_inflate(). + +Version 1.6.25beta02 [August 18, 2016] + Don't install pngcp; it conflicts with pngcp in the pngtools package. + Minor editing of INSTALL, (whitespace, added copyright line) + +Version 1.6.25rc01 [August 24, 2016] + No changes. + +Version 1.6.25rc02 [August 29, 2016] + Added MIPS support (Mandar Sahastrabuddhe <Mandar.Sahastrabuddhe@imgtec.com>). + Only the UP filter is currently implemented. + +Version 1.6.25rc03 [August 29, 2016] + Rebased contrib/intel/intel_sse.patch after the MIPS implementation. + +Version 1.6.25rc04 [August 30, 2016] + Added MIPS support for SUB, AVG, and PAETH filters (Mandar Sahastrabuddhe). + +Version 1.6.25rc05 [August 30, 2016] + Rebased contrib/intel/intel_sse.patch after the MIPS implementation update.. + +Version 1.6.25 [September 1, 2016] + No changes. + +Version 1.6.26beta01 [September 26, 2016] + Fixed handling zero length IDAT in pngfix (bug report by Agostino Sarubbo, + bugfix by John Bowler). + Do not issue a png_error() on read in png_set_pCAL() because png_handle_pCAL + has allocated memory that libpng needs to free. + Conditionally compile png_set_benign_errors() in pngread.c and pngtest.c + Issue a png_benign_error instead of a png_error on ADLER32 mismatch + while decoding compressed data chunks. + Changed PNG_ZLIB_VERNUM to ZLIB_VERNUM in pngpriv.h, pngstruct.h, and + pngrutil.c. + If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE, + ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs. + Issue png_benign_error() on ADLER32 checksum mismatch instead of png_error(). + Add tests/badcrc.png and tests/badadler.png to tests/pngtest. + Merged pngtest.c with libpng-1.7.0beta84/pngtest.c + +Version 1.6.26beta02 [October 1, 2016] + Updated the documentation about CRC and ADLER32 handling. + Quieted 117 warnings from clang-3.8 in pngtrans.c, pngread.c, + pngwrite.c, pngunknown.c, and pngvalid.c. + Quieted 58 (out of 144) -Wconversion compiler warnings by changing + flag definitions in pngpriv.h from 0xnnnn to 0xnnnnU and trivial changes + in png.c, pngread.c, and pngwutil.c. + +Version 1.6.26beta03 [October 2, 2016] + Removed contrib/libtests/*.orig and *.rej that slipped into the tarballs. + Quieted the 86 remaining -Wconversion compiler warnings by + revising the png_isaligned() macro and trivial changes in png.c, + pngerror.c, pngget.c, pngmem.c, pngset.c, pngrtran.c, pngrutil.c, + pngwtran.c, pngwrite.c, and pngwutil.c. + +Version 1.6.26beta04 [October 3, 2016] + Quieted (bogus?) clang warnings about "absolute value has no effect" + when PNG_USE_ABS is defined. + Fixed offsets in contrib/intel/intel_sse.patch + +Version 1.6.26beta05 [October 6, 2016] + Changed integer constant 4294967294 to unsigned 4294967294U in pngconf.h + to avoid a signed/unsigned compare in the preprocessor. + +Version 1.6.26beta06 [October 7, 2016] + Use zlib-1.2.8.1 inflateValidate() instead of inflateReset2() to + optionally avoid ADLER32 evaluation. + +Version 1.6.26rc01 [October 12, 2016] + No changes. + +Version 1.6.26 [October 20, 2016] + Cosmetic change, "ptr != 0" to "ptr != NULL" in png.c and pngrutil.c + Despammed email addresses (replaced "@" with " at "). + +Version 1.6.27beta01 [November 2, 2016] + Restrict the new ADLER32-skipping to IDAT chunks. It broke iCCP chunk + handling: an erroneous iCCP chunk would throw a png_error and reject the + entire PNG image instead of rejecting just the iCCP chunk with a warning, + if built with zlib-1.2.8.1. + +Version 1.6.27rc01 [December 27, 2016] + Control ADLER32 checking with new PNG_IGNORE_ADLER32 option. Fixes + an endless loop when handling erroneous ADLER32 checksums; bug + introduced in libpng-1.6.26. + Removed the use of a macro containing the pre-processor 'defined' + operator. It is unclear whether this is valid; a macro that + "generates" 'defined' is not permitted, but the use of the word + "generates" within the C90 standard seems to imply more than simple + substitution of an expression itself containing a well-formed defined + operation. + Added ARM support to CMakeLists.txt (Andreas Franek). + +Version 1.6.27 [December 29, 2016] + Fixed a potential null pointer dereference in png_set_text_2() (bug report + and patch by Patrick Keshishian, CVE-2016-10087). + +Version 1.6.28rc01 [January 3, 2017] + Fixed arm/aarch64 detection in CMakeLists.txt (Gianfranco Costamagna). + Added option to Cmake build allowing a custom location of zlib to be + specified in a scenario where libpng is being built as a subproject + alongside zlib by another project (Sam Serrels). + Changed png_ptr->options from a png_byte to png_uint_32, to accommodate + up to 16 options. + +Version 1.6.28rc02 [January 4, 2017] + Added "include(GNUInstallDirs)" to CMakeLists.txt (Gianfranco Costamagna). + Moved SSE2 optimization code into the main libpng source directory. + Configure libpng with "configure --enable-intel-sse" or compile + libpng with "-DPNG_INTEL_SSE" in CPPFLAGS to enable it. + +Version 1.6.28rc03 [January 4, 2017] + Backed out the SSE optimization and last CMakeLists.txt to allow time for QA. + +Version 1.6.28 [January 5, 2017] + No changes. + +Version 1.6.29beta01 [January 12, 2017] + Readded "include(GNUInstallDirs)" to CMakeLists.txt (Gianfranco Costamagna). + Moved SSE2 optimization code into the main libpng source directory. + Configure libpng with "configure --enable-intel-sse" or compile + libpng with "-DPNG_INTEL_SSE" in CPPFLAGS to enable it. + Simplified conditional compilation in pngvalid.c, for AIX (Michael Felt). + +Version 1.6.29beta02 [February 22, 2017] + Avoid conditional directives that break statements in pngrutil.c (Romero + Malaquias) + The contrib/examples/pngtopng.c recovery code was in the wrong "if" + branches; the comments were correct. + Added code for PowerPC VSX optimisation (Vadim Barkov). + +Version 1.6.29beta03 [March 1, 2017] + Avoid potential overflow of shift operations in png_do_expand() (Aaron Boxer). + Change test ZLIB_VERNUM >= 0x1281 to ZLIB_VERNUM >= 0x1290 in pngrutil.c + because Solaris 11 distributes zlib-1.2.8.f that is older than 1.2.8.1, + as suggested in zlib FAQ, item 24. + Suppress clang warnings about implicit sign changes in png.c + +Version 1.6.29 [March 16, 2017] + No changes. + +Version 1.6.30beta01 [April 1, 2017] + Added missing "$(CPPFLAGS)" to the compile line for c.pic.o in + makefile.linux and makefile.solaris-x86 (Cosmin). + Revised documentation of png_get_error_ptr() in the libpng manual. + Silence clang -Wcomma and const drop warnings (Viktor Szakats). + Update Sourceforge URLs in documentation (https instead of http). + +Version 1.6.30beta02 [April 22, 2017] + Document need to check for integer overflow when allocating a pixel + buffer for multiple rows in contrib/gregbook, contrib/pngminus, + example.c, and in the manual (suggested by Jaeseung Choi). This + is similar to the bug reported against pngquant in CVE-2016-5735. + Removed reference to the obsolete PNG_SAFE_LIMITS macro in the documentation. + +Version 1.6.30beta03 [May 22, 2017] + Check for integer overflow in contrib/visupng and contrib/tools/genpng. + Do not double evaluate CMAKE_SYSTEM_PROCESSOR in CMakeLists.txt. + Test CMAKE_HOST_WIN32 instead of WIN32 in CMakeLists.txt. + Fix some URL in documentation. + +Version 1.6.30beta04 [June 7, 2017] + Avoid writing an empty IDAT when the last IDAT exactly fills the + compression buffer (bug report by Brian Baird). This bug was + introduced in libpng-1.6.0. + +Version 1.6.30rc01 [June 14, 2017] + No changes. + +Version 1.6.30rc02 [June 25, 2017] + Update copyright year in pnglibconf.h, make ltmain.sh executable. + Add a reference to the libpng.download site in README. + +Version 1.6.30 [June 28, 2017] + No changes. + +Version 1.6.31beta01 [July 5, 2017] + Guard the definition of _POSIX_SOURCE in pngpriv.h (AIX already defines it; + bug report by Michael Felt). + Revised pngpriv.h to work around failure to compile arm/filter_neon.S + ("typedef" directive is unrecognized by the assembler). The problem + was introduced in libpng-1.6.30beta01. + Added "Requires: zlib" to libpng.pc.in (Pieter Neerincx). + Added special case for FreeBSD in arm/filter_neon.S (Maya Rashish). + +Version 1.6.31beta02 [July 8, 2017] + Added instructions for disabling hardware optimizations in INSTALL. + Added "--enable-hardware-optimizations" configuration flag to enable + or disable all hardware optimizations with one flag. + +Version 1.6.31beta03 [July 9, 2017] + Updated CMakeLists.txt to add INTEL_SSE and MIPS_MSA platforms. + Changed "int" to "png_size_t" in intel/filter_sse2.c to prevent + possible integer overflow (Bug report by John Bowler). + Quieted "declaration after statement" warnings in intel/filter_sse2.c. + Added scripts/makefile-linux-opt, which has hardware optimizations enabled. + +Version 1.6.31beta04 [July 11, 2017] + Removed one of the GCC-7.1.0 'strict-overflow' warnings that result when + integers appear on both sides of a compare. Worked around the others by + forcing the strict-overflow setting in the relevant functions to a level + where they are not reported (John Bowler). + Changed "FALL THROUGH" comments to "FALLTHROUGH" because GCC doesn't like + the space. + Worked around some C-style casts from (void*) because g++ 5.4.0 objects + to them. + Increased the buffer size for 'sprint' to pass the gcc 7.1.0 'sprint + overflow' check that is on by default with -Wall -Wextra. + +Version 1.6.31beta05 [July 13, 2017] + Added eXIf chunk support. + +Version 1.6.31beta06 [July 17, 2017] + Added a minimal eXIf chunk (with Orientation and FocalLengthIn35mmFilm + tags) to pngtest.png. + +Version 1.6.31beta07 [July 18, 2017] + Revised the eXIf chunk in pngtest.png to fix "Bad IFD1 Directory" warning. + +Version 1.6.31rc01 [July 19, 2017] + No changes. + +Version 1.6.31rc02 [July 25, 2017] + Fixed typo in example.c (png_free_image should be png_image_free) (Bug + report by John Smith) + +Version 1.6.31 [July 27, 2017] + No changes. + +Version 1.6.32beta01 [July 31, 2017] + Avoid possible NULL dereference in png_handle_eXIf when benign_errors + are allowed. Avoid leaking the input buffer "eXIf_buf". + Eliminated png_ptr->num_exif member from pngstruct.h and added num_exif + to arguments for png_get_eXIf() and png_set_eXIf(). + Added calls to png_handle_eXIf(() in pngread.c and png_write_eXIf() in + pngwrite.c, and made various other fixes to png_write_eXIf(). + Changed name of png_get_eXIF and png_set_eXIf() to png_get_eXIf_1() and + png_set_eXIf_1(), respectively, to avoid breaking API compatibility + with libpng-1.6.31. + +Version 1.6.32beta02 [August 1, 2017] + Updated contrib/libtests/pngunknown.c with eXIf chunk. + +Version 1.6.32beta03 [August 2, 2017] + Initialized btoa[] in pngstest.c + Stop memory leak when returning from png_handle_eXIf() with an error + (Bug report from the OSS-fuzz project). + +Version 1.6.32beta04 [August 2, 2017] + Replaced local eXIf_buf with info_ptr-eXIf_buf in png_handle_eXIf(). + Update libpng.3 and libpng-manual.txt about eXIf functions. + +Version 1.6.32beta05 [August 2, 2017] + Restored png_get_eXIf() and png_set_eXIf() to maintain API compatibility. + +Version 1.6.32beta06 [August 2, 2017] + Removed png_get_eXIf_1() and png_set_eXIf_1(). + +Version 1.6.32beta07 [August 3, 2017] + Check length of all chunks except IDAT against user limit to fix an + OSS-fuzz issue (Fixes CVE-2017-12652). + +Version 1.6.32beta08 [August 3, 2017] + Check length of IDAT against maximum possible IDAT size, accounting + for height, rowbytes, interlacing and zlib/deflate overhead. + Restored png_get_eXIf_1() and png_set_eXIf_1(), because strlen(eXIf_buf) + does not work (the eXIf chunk data can contain zeroes). + +Version 1.6.32beta09 [August 3, 2017] + Require cmake-2.8.8 in CMakeLists.txt. Revised symlink creation, + no longer using deprecated cmake LOCATION feature (Clifford Yapp). + Fixed five-byte error in the calculation of IDAT maximum possible size. + +Version 1.6.32beta10 [August 5, 2017] + Moved chunk-length check into a png_check_chunk_length() private + function (Suggested by Max Stepin). + Moved bad pngs from tests to contrib/libtests/crashers + Moved testing of bad pngs into a separate tests/pngtest-badpngs script + Added the --xfail (expected FAIL) option to pngtest.c. It writes XFAIL + in the output but PASS for the libpng test. + Require cmake-3.0.2 in CMakeLists.txt (Clifford Yapp). + Fix "const" declaration info_ptr argument to png_get_eXIf_1() and the + num_exif argument to png_get_eXIf_1() (Github Issue 171). + +Version 1.6.32beta11 [August 7, 2017] + Added "eXIf" to "chunks_to_ignore[]" in png_set_keep_unknown_chunks(). + Added huge_IDAT.png and empty_ancillary_chunks.png to testpngs/crashers. + Make pngtest --strict, --relax, --xfail options imply -m (multiple). + Removed unused chunk_name parameter from png_check_chunk_length(). + Relocated setting free_me for eXIf data, to stop an OSS-fuzz leak. + Initialize profile_header[] in png_handle_iCCP() to fix OSS-fuzz issue. + Initialize png_ptr->row_buf[0] to 255 in png_read_row() to fix OSS-fuzz UMR. + Attempt to fix a UMR in png_set_text_2() to fix OSS-fuzz issue. + Increase minimum zlib stream from 9 to 14 in png_handle_iCCP(), to account + for the minimum 'deflate' stream, and relocate the test to a point + after the keyword has been read. + Check that the eXIf chunk has at least 2 bytes and begins with "II" or "MM". + +Version 1.6.32rc01 [August 18, 2017] + Added a set of "huge_xxxx_chunk.png" files to contrib/testpngs/crashers, + one for each known chunk type, with length = 2GB-1. + Check for 0 return from png_get_rowbytes() and added some (size_t) typecasts + in contrib/pngminus/*.c to stop some Coverity issues (162705, 162706, + and 162707). + Renamed chunks in contrib/testpngs/crashers to avoid having files whose + names differ only in case; this causes problems with some platforms + (github issue #172). + +Version 1.6.32rc02 [August 22, 2017] + Added contrib/oss-fuzz directory which contains files used by the oss-fuzz + project (https://github.com/google/oss-fuzz/tree/master/projects/libpng). + +Version 1.6.32 [August 24, 2017] + No changes. + +Version 1.6.33beta01 [August 28, 2017] + Added PNGMINUS_UNUSED macro to contrib/pngminus/p*.c and added missing + parenthesis in contrib/pngminus/pnm2png.c (bug report by Christian Hesse). + Fixed off-by-one error in png_do_check_palette_indexes() (Bug report + by Mick P., Source Forge Issue #269). + +Version 1.6.33beta02 [September 3, 2017] + Initialize png_handler.row_ptr in contrib/oss-fuzz/libpng_read_fuzzer.cc + to fix shortlived oss-fuzz issue 3234. + Compute a larger limit on IDAT because some applications write a deflate + buffer for each row (Bug report by Andrew Church). + Use current date (DATE) instead of release-date (RDATE) in last + changed date of contrib/oss-fuzz files. + Enabled ARM support in CMakeLists.txt (Bernd Kuhls). + +Version 1.6.33beta03 [September 14, 2017] + Fixed incorrect typecast of some arguments to png_malloc() and + png_calloc() that were png_uint_32 instead of png_alloc_size_t + (Bug report by "irwir" in Github libpng issue #175). + Use pnglibconf.h.prebuilt when building for ANDROID with cmake (Github + issue 162, by rcdailey). + +Version 1.6.33rc01 [September 20, 2017] + Initialize memory allocated by png_inflate to zero, using memset, to + stop an oss-fuzz "use of uninitialized value" detection in png_set_text_2() + due to truncated iTXt or zTXt chunk. + Initialize memory allocated by png_read_buffer to zero, using memset, to + stop an oss-fuzz "use of uninitialized value" detection in + png_icc_check_tag_table() due to truncated iCCP chunk. + Removed a redundant test (suggested by "irwir" in Github issue #180). + +Version 1.6.33rc02 [September 23, 2017] + Added an interlaced version of each file in contrib/pngsuite. + Relocate new memset() call in pngrutil.c. + Removed more redundant tests (suggested by "irwir" in Github issue #180). + Add support for loading images with associated alpha in the Simplified + API (Samuel Williams). + +Version 1.6.33 [September 28, 2017] + Revert contrib/oss-fuzz/libpng_read_fuzzer.cc to libpng-1.6.32 state. + Initialize png_handler.row_ptr in contrib/oss-fuzz/libpng_read_fuzzer.cc + Add end_info structure and png_read_end() to the libpng fuzzer. + +Version 1.6.34 [September 29, 2017] + Removed contrib/pngsuite/i*.png; some of them caused test failures. + +Version 1.6.35beta01 [March 6, 2018] + Restored 21 of the contrib/pngsuite/i*.png, which do not cause test + failures. Placed the remainder in contrib/pngsuite/interlaced/i*.png. + Added calls to png_set_*() transforms commonly used by browsers to + the fuzzer. + Removed some unnecessary brackets in pngrtran.c + Fixed miscellaneous typos (Patch by github user "luzpaz"). + Change "ASM C" to "C ASM" in CMakeLists.txt + Fixed incorrect handling of bKGD chunk in sub-8-bit files (Cosmin) + Added hardware optimization directories to zip and 7z distributions. + Fixed incorrect bitmask for options. + Fixed many spelling typos. + +Version 1.6.35beta02 [March 28, 2018] + Make png_get_iCCP consistent with man page (allow compression-type argument + to be NULL, bug report by Lenard Szolnoki). + +Version 1.6.35 [July 15, 2018] + Replaced the remaining uses of png_size_t with size_t (Cosmin) + Fixed the calculation of row_factor in png_check_chunk_length + (reported by Thuan Pham in SourceForge issue #278) + Added missing parentheses to a macro definition + (suggested by "irwir" in GitHub issue #216) + +Version 1.6.36 [December 1, 2018] + Optimized png_do_expand_palette for ARM processors. + Improved performance by around 10-22% on a recent ARM Chromebook. + (Contributed by Richard Townsend, ARM Holdings) + Fixed manipulation of machine-specific optimization options. + (Contributed by Vicki Pfau) + Used memcpy instead of manual pointer arithmetic on Intel SSE2. + (Contributed by Samuel Williams) + Fixed build errors with MSVC on ARM64. + (Contributed by Zhijie Liang) + Fixed detection of libm in CMakeLists. + (Contributed by Cameron Cawley) + Fixed incorrect creation of pkg-config file in CMakeLists. + (Contributed by Kyle Bentley) + Fixed the CMake build on Windows MSYS by avoiding symlinks. + Fixed a build warning on OpenBSD. + (Contributed by Theo Buehler) + Fixed various typos in comments. + (Contributed by "luz.paz") + Raised the minimum required CMake version from 3.0.2 to 3.1. + Removed yet more of the vestigial support for pre-ANSI C compilers. + Removed ancient makefiles for ancient systems that have been broken + across all previous libpng-1.6.x versions. + Removed the Y2K compliance statement and the export control + information. + Applied various code style and documentation fixes. + +Version 1.6.37 [April 14, 2019] + Fixed a use-after-free vulnerability (CVE-2019-7317) in png_image_free. + Fixed a memory leak in the ARM NEON implementation of png_do_expand_palette. + Fixed a memory leak in pngtest.c. + Fixed two vulnerabilities (CVE-2018-14048, CVE-2018-14550) in + contrib/pngminus; refactor. + Changed the license of contrib/pngminus to MIT; refresh makefile and docs. + (Contributed by Willem van Schaik) + Fixed a typo in the libpng license v2. + (Contributed by Miguel Ojeda) + Added makefiles for AddressSanitizer-enabled builds. + Cleaned up various makefiles. + +Send comments/corrections/commendations to png-mng-implement at lists.sf.net. +Subscription is required; visit +https://lists.sourceforge.net/lists/listinfo/png-mng-implement +to subscribe. diff --git a/media/libpng/LICENSE b/media/libpng/LICENSE new file mode 100644 index 0000000000..e0c5b531cf --- /dev/null +++ b/media/libpng/LICENSE @@ -0,0 +1,134 @@ +COPYRIGHT NOTICE, DISCLAIMER, and LICENSE +========================================= + +PNG Reference Library License version 2 +--------------------------------------- + + * Copyright (c) 1995-2019 The PNG Reference Library Authors. + * Copyright (c) 2018-2019 Cosmin Truta. + * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson. + * Copyright (c) 1996-1997 Andreas Dilger. + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + +The software is supplied "as is", without warranty of any kind, +express or implied, including, without limitation, the warranties +of merchantability, fitness for a particular purpose, title, and +non-infringement. In no event shall the Copyright owners, or +anyone distributing the software, be liable for any damages or +other liability, whether in contract, tort or otherwise, arising +from, out of, or in connection with the software, or the use or +other dealings in the software, even if advised of the possibility +of such damage. + +Permission is hereby granted to use, copy, modify, and distribute +this software, or portions hereof, for any purpose, without fee, +subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you + must not claim that you wrote the original software. If you + use this software in a product, an acknowledgment in the product + documentation would be appreciated, but is not required. + + 2. Altered source versions must be plainly marked as such, and must + not be misrepresented as being the original software. + + 3. This Copyright notice may not be removed or altered from any + source or altered source distribution. + + +PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35) +----------------------------------------------------------------------- + +libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are +Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are +derived from libpng-1.0.6, and are distributed according to the same +disclaimer and license as libpng-1.0.6 with the following individuals +added to the list of Contributing Authors: + + Simon-Pierre Cadieux + Eric S. Raymond + Mans Rullgard + Cosmin Truta + Gilles Vollant + James Yu + Mandar Sahastrabuddhe + Google Inc. + Vadim Barkov + +and with the following additions to the disclaimer: + + There is no warranty against interference with your enjoyment of + the library or against infringement. There is no warranty that our + efforts or the library will fulfill any of your particular purposes + or needs. This library is provided with all faults, and the entire + risk of satisfactory quality, performance, accuracy, and effort is + with the user. + +Some files in the "contrib" directory and some configure-generated +files that are distributed with libpng have other copyright owners, and +are released under other open source licenses. + +libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are +Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from +libpng-0.96, and are distributed according to the same disclaimer and +license as libpng-0.96, with the following individuals added to the +list of Contributing Authors: + + Tom Lane + Glenn Randers-Pehrson + Willem van Schaik + +libpng versions 0.89, June 1996, through 0.96, May 1997, are +Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, +and are distributed according to the same disclaimer and license as +libpng-0.88, with the following individuals added to the list of +Contributing Authors: + + John Bowler + Kevin Bracey + Sam Bushell + Magnus Holmgren + Greg Roelofs + Tom Tanner + +Some files in the "scripts" directory have other copyright owners, +but are released under this license. + +libpng versions 0.5, May 1995, through 0.88, January 1996, are +Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + +For the purposes of this copyright and license, "Contributing Authors" +is defined as the following set of individuals: + + Andreas Dilger + Dave Martindale + Guy Eric Schalnat + Paul Schmidt + Tim Wegner + +The PNG Reference Library is supplied "AS IS". The Contributing +Authors and Group 42, Inc. disclaim all warranties, expressed or +implied, including, without limitation, the warranties of +merchantability and of fitness for any purpose. The Contributing +Authors and Group 42, Inc. assume no liability for direct, indirect, +incidental, special, exemplary, or consequential damages, which may +result from the use of the PNG Reference Library, even if advised of +the possibility of such damage. + +Permission is hereby granted to use, copy, modify, and distribute this +source code, or portions hereof, for any purpose, without fee, subject +to the following restrictions: + + 1. The origin of this source code must not be misrepresented. + + 2. Altered versions must be plainly marked as such and must not + be misrepresented as being the original source. + + 3. This Copyright notice may not be removed or altered from any + source or altered source distribution. + +The Contributing Authors and Group 42, Inc. specifically permit, +without fee, and encourage the use of this source code as a component +to supporting the PNG file format in commercial products. If you use +this source code in a product, acknowledgment is not required but would +be appreciated. diff --git a/media/libpng/MOZCHANGES b/media/libpng/MOZCHANGES new file mode 100644 index 0000000000..52bc5c712a --- /dev/null +++ b/media/libpng/MOZCHANGES @@ -0,0 +1,155 @@ +Changes made to pristine libpng source by mozilla.org developers. +Update the 'release' field in moz.yaml when you update this file. + +pnglibconf.h and moz.build are distributed under the Mozilla Public License, +v. 2.0. If a copy of the MPL was not distributed with this file, You can +obtain one at http://mozilla.org/MPL/2.0/. + +This modified version of libpng code adds animated PNG support and is +released under the same license as the upstream library. The modifications +are Copyright (c) 2006-2007 Andrew Smith, Copyright (c) 2008-2017 Max Stepin, +and are delimited by "#ifdef PNG_APNG_SUPPORTED / #endif" directives +surrounding them in the modified libpng source files. + +2019/04/15 -- Synced with libpng-1.6.37 (bug #1513236) + +2018/09/14 -- Synced with libpng-1.6.35 (bug #1491467). + +2017/08/30 -- Synced with libpng-1.6.34 (bug #1402057). + +2017/03/18 -- Synced with libpng-1.6.31 (bug #1377118). + +2017/03/18 -- Synced with libpng-1.6.29 (bug #1348356). + +2017/01/06 -- Synced with libpng-1.6.28 (bug #1328354). + +2016/12/29 -- Synced with libpng-1.6.27 (bug #1326234). + +2016/10/20 -- Synced with libpng-1.6.26 (bug #1311776). + +2016/09/01 -- Synced with libpng-1.6.25 (bug #1299590). + +2016/08/11 -- Enabled SSE2 support (bug #1276127). + +2016/08/06 -- Synced with libpng-1.6.24 (bug #1291986). + +2016/06/09 -- Synced with libpng-1.6.23 (bug #1275901). + +2016/01/16 -- Synced with libpng-1.6.21 (bug #1230757). + +2015/11/12 -- Synced with libpng-1.6.19 (bug #1224244). + +2015/07/30 -- Synced with libpng-1.6.18 (bug #1186977). + +2015/03/27 -- Synced with libpng-1.6.17 (bug #1147909). + +2014/12/22 -- Synced with libpng-1.6.16 (bug #1114360). + Added arm.patch file. + +2014/11/20 -- Synced with libpng-1.6.15 (bug #1102523). + +2014/10/23 -- Synced with libpng-1.6.14 (bug #1087841). + +2014/08/21 -- Synced with libpng-1.6.13 (bug #1021713). + Renamed mozpngconf.h to pnglibconf.h. + Revised system arm/filter_neon.S to include the lines + #define PNG_READ_SUPPORTED and #define MOZ_PNG_HAVE_ARM_NEON + because the moz.build system doesn't yet pass -DDefined + macros to the assembler. + +2014/03/21 -- Synced with libpng-1.6.10 (bug #980488) and disabled + PNG_WARNINGS and PNG_ERROR_TEXT in non-debug builds. + Limit image dimensions to 32767 (bug #251381, #591822, + and #967656). + +2014/03/04 -- Enabled PNG_WARNINGS and other stuff in mozpngconf.h + as part of enabling Freetype2 with PNG (bug #969814). + +2014/03/03 -- Fixed hang with empty IDAT (bug #974825). This will be + fixed in libpng-1.6.10. + +2014/02/18 -- Exposed png_error(), etc. redefinitions to applications + (moved them from pngpriv.h to png.h). This will be fixed + in libpng-1.6.10. + +2014/02/18 -- Disabled PNG_FIXED_POINT_SUPPORTED in mozpngconf.h (we + don't need both FIXED and FLOATING_POINT support). + +2014/02/15 -- Synced with libpng-1.6.9 (bug #952505). + +2014/02/11 -- Fixed crash with empty PLTE, CVE-2013-6954 (bug #945912). + This will be fixed in libpng-1.6.9. + +2013/12/11 -- Enable ARM support (bug #832390). + +2013/11/17 -- Synced with libpng-1.6.7 (bug #938740). + +2013/09/21 -- Synced with libpng-1.6.6 (bug #841734). + +2013/07/17 -- Synced with libpng-1.5.17 (bug #886499). + +2013/06/06 -- Synced with libpng-1.5.16 (bug #873001). + +2013/04/11 -- Synced with libpng-1.5.15 (bug #858578). + +2013/01/24 -- Synced with libpng-1.5.14 (bug #832487). + +2013/01/23 -- Disabled TEXT support in mozpngconf.h (bug #833594). + +2012/10/02 -- Synced with libpng-1.5.13 (bug #775662). + +2012/07/16 -- Add an "APNG-aware app" flag (bug #759067). + +2012/07/04 -- Synced with libpng-1.5.11 (bug #771394). + +2012/04/13 -- Synced with libpng-1.5.10 (bug #745178). + +2012/02/19 -- Synced with libpng-1.5.9 (bug #648690). + +2011/07/20 -- Synced with libpng-1.4.8 (bug #669863). + +2011/04/08 -- Synced with libpng-1.4.7 (bug #624133). + +2010/06/30 -- Synced with libpng-1.4.3 (bug #564792). + +2010/02/26 -- Synced with libpng-1.4.1 (bug #544747). + +2010/01/04 -- Synced with libpng-1.4.0 (bug #532645). + +2009/09/10 -- Synced with libpng-1.2.40 (bug #492200 and #504805). + Moved location of acTL chunk to just after IHDR + in output PNG file. + +2009/06/01 -- Eliminated incorrect test and rejection of APNG + blend_op in opaque images (bug #441971 and #455140). + +2009/05/17 -- Always clear prev_row for each APNG frame (bug #463465). + +2009/02/19 -- Synced with libpng-1.2.35 (bug #478901). + +2008/08/21 -- Synced with libpng-1.2.31 (bug #418900). + +2008/03/29 -- Initialize prev_row for each APNG frame, only when + the frame size increases (bug #420416). + +2008/01/18 -- Synced with libpng-1.2.24 (bug #408429). + +2007/11/13 -- Synced with libpng-1.2.23; Removed pnggccrd.c and pngvcrd.c; + Reduced footprint by removing error and warning text in + non-debug builds via settings in mozpngconf.h (bug #403239). + +2007/11/06 -- Synced with libpng-1.2.22 (removes MMX support) (bug #386585). + +2007/07/27 -- Enabled cHRM and iCCP chunks for color management (bug #16769). + +2007/05/05 -- Zeroed png_ptr->num_trans on CRC error (bug #374810). + +2007/04/19 -- Synced with libpng-1.2.16 tree (bug #373249). + +2007/03/20 -- Added support for APNG (bug #257197). + +2006/06/27 -- Synced with libpng-1.2.12 tree (bug #334110). + +2004/10/07 -- Synced with libpng-1.2.7 tree (bug #261922). + +2004/10/07 -- Added mozpngconf.h (bug #208607). diff --git a/media/libpng/README b/media/libpng/README new file mode 100644 index 0000000000..cfc1f0e3dc --- /dev/null +++ b/media/libpng/README @@ -0,0 +1,183 @@ +README for libpng version 1.6.37 - April 14, 2019 +================================================= + +See the note about version numbers near the top of png.h. +See INSTALL for instructions on how to install libpng. + +Libpng comes in several distribution formats. Get libpng-*.tar.gz or +libpng-*.tar.xz or if you want UNIX-style line endings in the text +files, or lpng*.7z or lpng*.zip if you want DOS-style line endings. + +Version 0.89 was the first official release of libpng. Don't let the +fact that it's the first release fool you. The libpng library has been +in extensive use and testing since mid-1995. By late 1997 it had +finally gotten to the stage where there hadn't been significant +changes to the API in some time, and people have a bad feeling about +libraries with versions < 1.0. Version 1.0.0 was released in +March 1998. + +**** +Note that some of the changes to the png_info structure render this +version of the library binary incompatible with libpng-0.89 or +earlier versions if you are using a shared library. The type of the +"filler" parameter for png_set_filler() has changed from png_byte to +png_uint_32, which will affect shared-library applications that use +this function. + +To avoid problems with changes to the internals of the png info_struct, +new APIs have been made available in 0.95 to avoid direct application +access to info_ptr. These functions are the png_set_<chunk> and +png_get_<chunk> functions. These functions should be used when +accessing/storing the info_struct data, rather than manipulating it +directly, to avoid such problems in the future. + +It is important to note that the APIs did not make current programs +that access the info struct directly incompatible with the new +library, through libpng-1.2.x. In libpng-1.4.x, which was meant to +be a transitional release, members of the png_struct and the +info_struct can still be accessed, but the compiler will issue a +warning about deprecated usage. Since libpng-1.5.0, direct access +to these structs is not allowed, and the definitions of the structs +reside in private pngstruct.h and pnginfo.h header files that are not +accessible to applications. It is strongly suggested that new +programs use the new APIs (as shown in example.c and pngtest.c), and +older programs be converted to the new format, to facilitate upgrades +in the future. +**** + +Additions since 0.90 include the ability to compile libpng as a +Windows DLL, and new APIs for accessing data in the info struct. +Experimental functions include the ability to set weighting and cost +factors for row filter selection, direct reads of integers from buffers +on big-endian processors that support misaligned data access, faster +methods of doing alpha composition, and more accurate 16->8 bit color +conversion. + +The additions since 0.89 include the ability to read from a PNG stream +which has had some (or all) of the signature bytes read by the calling +application. This also allows the reading of embedded PNG streams that +do not have the PNG file signature. As well, it is now possible to set +the library action on the detection of chunk CRC errors. It is possible +to set different actions based on whether the CRC error occurred in a +critical or an ancillary chunk. + +For a detailed description on using libpng, read libpng-manual.txt. +For examples of libpng in a program, see example.c and pngtest.c. For +usage information and restrictions (what little they are) on libpng, +see png.h. For a description on using zlib (the compression library +used by libpng) and zlib's restrictions, see zlib.h + +I have included a general makefile, as well as several machine and +compiler specific ones, but you may have to modify one for your own +needs. + +You should use zlib 1.0.4 or later to run this, but it MAY work with +versions as old as zlib 0.95. Even so, there are bugs in older zlib +versions which can cause the output of invalid compression streams for +some images. + +You should also note that zlib is a compression library that is useful +for more things than just PNG files. You can use zlib as a drop-in +replacement for fread() and fwrite(), if you are so inclined. + +zlib should be available at the same place that libpng is, or at +https://zlib.net. + +You may also want a copy of the PNG specification. It is available +as an RFC, a W3C Recommendation, and an ISO/IEC Standard. You can find +these at http://www.libpng.org/pub/png/pngdocs.html . + +This code is currently being archived at libpng.sourceforge.io in the +[DOWNLOAD] area, and at http://libpng.download/src . + +This release, based in a large way on Glenn's, Guy's and Andreas' +earlier work, was created and will be supported by myself and the PNG +development group. + +Send comments/corrections/commendations to png-mng-implement at +lists.sourceforge.net (subscription required; visit +https://lists.sourceforge.net/lists/listinfo/png-mng-implement +to subscribe). + +Send general questions about the PNG specification to png-mng-misc +at lists.sourceforge.net (subscription required; visit +https://lists.sourceforge.net/lists/listinfo/png-mng-misc to +subscribe). + +Files in this distribution: + + ANNOUNCE => Announcement of this version, with recent changes + AUTHORS => List of contributing authors + CHANGES => Description of changes between libpng versions + KNOWNBUG => List of known bugs and deficiencies + LICENSE => License to use and redistribute libpng + README => This file + TODO => Things not implemented in the current library + TRADEMARK => Trademark information + example.c => Example code for using libpng functions + libpng.3 => manual page for libpng (includes libpng-manual.txt) + libpng-manual.txt => Description of libpng and its functions + libpngpf.3 => manual page for libpng's private functions + png.5 => manual page for the PNG format + png.c => Basic interface functions common to library + png.h => Library function and interface declarations (public) + pngpriv.h => Library function and interface declarations (private) + pngconf.h => System specific library configuration (public) + pngstruct.h => png_struct declaration (private) + pnginfo.h => png_info struct declaration (private) + pngdebug.h => debugging macros (private) + pngerror.c => Error/warning message I/O functions + pngget.c => Functions for retrieving info from struct + pngmem.c => Memory handling functions + pngbar.png => PNG logo, 88x31 + pngnow.png => PNG logo, 98x31 + pngpread.c => Progressive reading functions + pngread.c => Read data/helper high-level functions + pngrio.c => Lowest-level data read I/O functions + pngrtran.c => Read data transformation functions + pngrutil.c => Read data utility functions + pngset.c => Functions for storing data into the info_struct + pngtest.c => Library test program + pngtest.png => Library test sample image + pngtrans.c => Common data transformation functions + pngwio.c => Lowest-level write I/O functions + pngwrite.c => High-level write functions + pngwtran.c => Write data transformations + pngwutil.c => Write utility functions + arm => Contains optimized code for the ARM platform + powerpc => Contains optimized code for the PowerPC platform + contrib => Contributions + arm-neon => Optimized code for ARM-NEON platform + powerpc-vsx => Optimized code for POWERPC-VSX platform + examples => Example programs + gregbook => source code for PNG reading and writing, from + Greg Roelofs' "PNG: The Definitive Guide", + O'Reilly, 1999 + libtests => Test programs + mips-msa => Optimized code for MIPS-MSA platform + pngminim => Minimal decoder, encoder, and progressive decoder + programs demonstrating use of pngusr.dfa + pngminus => Simple pnm2png and png2pnm programs + pngsuite => Test images + testpngs + tools => Various tools + visupng => Contains a MSVC workspace for VisualPng + intel => Optimized code for INTEL-SSE2 platform + mips => Optimized code for MIPS platform + projects => Contains project files and workspaces for + building a DLL + owatcom => Contains a WATCOM project for building libpng + visualc71 => Contains a Microsoft Visual C++ (MSVC) + workspace for building libpng and zlib + vstudio => Contains a Microsoft Visual C++ (MSVC) + workspace for building libpng and zlib + scripts => Directory containing scripts for building libpng: + (see scripts/README.txt for the list of scripts) + +Good luck, and happy coding! + + * Cosmin Truta (current maintainer, since 2018) + * Glenn Randers-Pehrson (former maintainer, 1998-2018) + * Andreas Eric Dilger (former maintainer, 1996-1997) + * Guy Eric Schalnat (original author and former maintainer, 1995-1996) + (formerly of Group 42, Inc.) diff --git a/media/libpng/TRADEMARK b/media/libpng/TRADEMARK new file mode 100644 index 0000000000..ac667187d6 --- /dev/null +++ b/media/libpng/TRADEMARK @@ -0,0 +1,8 @@ +TRADEMARK +========= + +The name "libpng" has not been registered by the Copyright owners +as a trademark in any jurisdiction. However, because libpng has +been distributed and maintained world-wide, continually since 1995, +the Copyright owners claim "common-law trademark protection" in any +jurisdiction where common-law trademark is recognized. diff --git a/media/libpng/apng.patch b/media/libpng/apng.patch new file mode 100644 index 0000000000..ab4ca59567 --- /dev/null +++ b/media/libpng/apng.patch @@ -0,0 +1,1602 @@ +diff --git a/png.h b/png.h +--- a/png.h ++++ b/png.h +@@ -329,8 +329,12 @@ + */ + # include "pnglibconf.h" + #endif + ++#define PNG_APNG_SUPPORTED ++#define PNG_READ_APNG_SUPPORTED ++#define PNG_WRITE_APNG_SUPPORTED ++ + #ifndef PNG_VERSION_INFO_ONLY + /* Machine specific configuration. */ + # include "pngconf.h" + #endif +@@ -424,8 +428,19 @@ extern "C" { + * constants. + * See pngconf.h for base types that vary by machine/system + */ + ++#ifdef PNG_APNG_SUPPORTED ++/* dispose_op flags from inside fcTL */ ++#define PNG_DISPOSE_OP_NONE 0x00 ++#define PNG_DISPOSE_OP_BACKGROUND 0x01 ++#define PNG_DISPOSE_OP_PREVIOUS 0x02 ++ ++/* blend_op flags from inside fcTL */ ++#define PNG_BLEND_OP_SOURCE 0x00 ++#define PNG_BLEND_OP_OVER 0x01 ++#endif /* APNG */ ++ + /* This triggers a compiler error in png.c, if png.c and png.h + * do not agree upon the version number. + */ + typedef char* png_libpng_version_1_6_37; +@@ -745,8 +760,12 @@ typedef png_unknown_chunk * * png_unknow + #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */ + #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */ + #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */ + #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */ ++#ifdef PNG_APNG_SUPPORTED ++#define PNG_INFO_acTL 0x20000U ++#define PNG_INFO_fcTL 0x40000U ++#endif + + /* This is used for the transformation routines, as some of them + * change these values for the row. It also should enable using + * the routines for other purposes. +@@ -782,8 +801,12 @@ typedef PNG_CALLBACK(void, *png_write_st + + #ifdef PNG_PROGRESSIVE_READ_SUPPORTED + typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); + typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); ++#ifdef PNG_APNG_SUPPORTED ++typedef PNG_CALLBACK(void, *png_progressive_frame_ptr, (png_structp, ++ png_uint_32)); ++#endif + + /* The following callback receives png_uint_32 row_number, int pass for the + * png_bytep data of the row. When transforming an interlaced image the + * row number is the row number within the sub-image of the interlace pass, so +@@ -3226,17 +3249,90 @@ PNG_EXPORT(244, int, png_set_option, (pn + /******************************************************************************* + * END OF HARDWARE AND SOFTWARE OPTIONS + ******************************************************************************/ + ++#ifdef PNG_APNG_SUPPORTED ++PNG_EXPORT(248, png_uint_32, png_get_acTL, (png_structp png_ptr, ++ png_infop info_ptr, png_uint_32 *num_frames, png_uint_32 *num_plays)); ++ ++PNG_EXPORT(249, png_uint_32, png_set_acTL, (png_structp png_ptr, ++ png_infop info_ptr, png_uint_32 num_frames, png_uint_32 num_plays)); ++ ++PNG_EXPORT(250, png_uint_32, png_get_num_frames, (png_structp png_ptr, ++ png_infop info_ptr)); ++ ++PNG_EXPORT(251, png_uint_32, png_get_num_plays, (png_structp png_ptr, ++ png_infop info_ptr)); ++ ++PNG_EXPORT(252, png_uint_32, png_get_next_frame_fcTL, ++ (png_structp png_ptr, png_infop info_ptr, png_uint_32 *width, ++ png_uint_32 *height, png_uint_32 *x_offset, png_uint_32 *y_offset, ++ png_uint_16 *delay_num, png_uint_16 *delay_den, png_byte *dispose_op, ++ png_byte *blend_op)); ++ ++PNG_EXPORT(253, png_uint_32, png_set_next_frame_fcTL, ++ (png_structp png_ptr, png_infop info_ptr, png_uint_32 width, ++ png_uint_32 height, png_uint_32 x_offset, png_uint_32 y_offset, ++ png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, ++ png_byte blend_op)); ++ ++PNG_EXPORT(254, png_uint_32, png_get_next_frame_width, ++ (png_structp png_ptr, png_infop info_ptr)); ++PNG_EXPORT(255, png_uint_32, png_get_next_frame_height, ++ (png_structp png_ptr, png_infop info_ptr)); ++PNG_EXPORT(256, png_uint_32, png_get_next_frame_x_offset, ++ (png_structp png_ptr, png_infop info_ptr)); ++PNG_EXPORT(257, png_uint_32, png_get_next_frame_y_offset, ++ (png_structp png_ptr, png_infop info_ptr)); ++PNG_EXPORT(258, png_uint_16, png_get_next_frame_delay_num, ++ (png_structp png_ptr, png_infop info_ptr)); ++PNG_EXPORT(259, png_uint_16, png_get_next_frame_delay_den, ++ (png_structp png_ptr, png_infop info_ptr)); ++PNG_EXPORT(260, png_byte, png_get_next_frame_dispose_op, ++ (png_structp png_ptr, png_infop info_ptr)); ++PNG_EXPORT(261, png_byte, png_get_next_frame_blend_op, ++ (png_structp png_ptr, png_infop info_ptr)); ++PNG_EXPORT(262, png_byte, png_get_first_frame_is_hidden, ++ (png_structp png_ptr, png_infop info_ptr)); ++PNG_EXPORT(263, png_uint_32, png_set_first_frame_is_hidden, ++ (png_structp png_ptr, png_infop info_ptr, png_byte is_hidden)); ++ ++#ifdef PNG_READ_APNG_SUPPORTED ++PNG_EXPORT(264, void, png_read_frame_head, (png_structp png_ptr, ++ png_infop info_ptr)); ++#ifdef PNG_PROGRESSIVE_READ_SUPPORTED ++PNG_EXPORT(265, void, png_set_progressive_frame_fn, (png_structp png_ptr, ++ png_progressive_frame_ptr frame_info_fn, ++ png_progressive_frame_ptr frame_end_fn)); ++#endif /* PROGRESSIVE_READ */ ++#endif /* READ_APNG */ ++ ++#ifdef PNG_WRITE_APNG_SUPPORTED ++PNG_EXPORT(266, void, png_write_frame_head, (png_structp png_ptr, ++ png_infop info_ptr, png_bytepp row_pointers, ++ png_uint_32 width, png_uint_32 height, ++ png_uint_32 x_offset, png_uint_32 y_offset, ++ png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, ++ png_byte blend_op)); ++ ++PNG_EXPORT(267, void, png_write_frame_tail, (png_structp png_ptr, ++ png_infop info_ptr)); ++#endif /* WRITE_APNG */ ++#endif /* APNG */ ++ + /* Maintainer: Put new public prototypes here ^, in libpng.3, in project + * defs, and in scripts/symbols.def. + */ + + /* The last ordinal number (this is the *last* one already used; the next + * one to use is one more than this.) + */ + #ifdef PNG_EXPORT_LAST_ORDINAL ++#ifdef PNG_APNG_SUPPORTED ++ PNG_EXPORT_LAST_ORDINAL(269); ++#else + PNG_EXPORT_LAST_ORDINAL(249); ++#endif /* APNG */ + #endif + + #ifdef __cplusplus + } +diff --git a/pngget.c b/pngget.c +--- a/pngget.c ++++ b/pngget.c +@@ -1245,5 +1245,167 @@ png_get_palette_max(png_const_structp pn + } + # endif + #endif + ++#ifdef PNG_APNG_SUPPORTED ++png_uint_32 PNGAPI ++png_get_acTL(png_structp png_ptr, png_infop info_ptr, ++ png_uint_32 *num_frames, png_uint_32 *num_plays) ++{ ++ png_debug1(1, "in %s retrieval function", "acTL"); ++ ++ if (png_ptr != NULL && info_ptr != NULL && ++ (info_ptr->valid & PNG_INFO_acTL) != 0 && ++ num_frames != NULL && num_plays != NULL) ++ { ++ *num_frames = info_ptr->num_frames; ++ *num_plays = info_ptr->num_plays; ++ return (1); ++ } ++ ++ return (0); ++} ++ ++png_uint_32 PNGAPI ++png_get_num_frames(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_debug(1, "in png_get_num_frames()"); ++ ++ if (png_ptr != NULL && info_ptr != NULL) ++ return (info_ptr->num_frames); ++ return (0); ++} ++ ++png_uint_32 PNGAPI ++png_get_num_plays(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_debug(1, "in png_get_num_plays()"); ++ ++ if (png_ptr != NULL && info_ptr != NULL) ++ return (info_ptr->num_plays); ++ return (0); ++} ++ ++png_uint_32 PNGAPI ++png_get_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr, ++ png_uint_32 *width, png_uint_32 *height, ++ png_uint_32 *x_offset, png_uint_32 *y_offset, ++ png_uint_16 *delay_num, png_uint_16 *delay_den, ++ png_byte *dispose_op, png_byte *blend_op) ++{ ++ png_debug1(1, "in %s retrieval function", "fcTL"); ++ ++ if (png_ptr != NULL && info_ptr != NULL && ++ (info_ptr->valid & PNG_INFO_fcTL) != 0 && ++ width != NULL && height != NULL && ++ x_offset != NULL && y_offset != NULL && ++ delay_num != NULL && delay_den != NULL && ++ dispose_op != NULL && blend_op != NULL) ++ { ++ *width = info_ptr->next_frame_width; ++ *height = info_ptr->next_frame_height; ++ *x_offset = info_ptr->next_frame_x_offset; ++ *y_offset = info_ptr->next_frame_y_offset; ++ *delay_num = info_ptr->next_frame_delay_num; ++ *delay_den = info_ptr->next_frame_delay_den; ++ *dispose_op = info_ptr->next_frame_dispose_op; ++ *blend_op = info_ptr->next_frame_blend_op; ++ return (1); ++ } ++ ++ return (0); ++} ++ ++png_uint_32 PNGAPI ++png_get_next_frame_width(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_debug(1, "in png_get_next_frame_width()"); ++ ++ if (png_ptr != NULL && info_ptr != NULL) ++ return (info_ptr->next_frame_width); ++ return (0); ++} ++ ++png_uint_32 PNGAPI ++png_get_next_frame_height(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_debug(1, "in png_get_next_frame_height()"); ++ ++ if (png_ptr != NULL && info_ptr != NULL) ++ return (info_ptr->next_frame_height); ++ return (0); ++} ++ ++png_uint_32 PNGAPI ++png_get_next_frame_x_offset(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_debug(1, "in png_get_next_frame_x_offset()"); ++ ++ if (png_ptr != NULL && info_ptr != NULL) ++ return (info_ptr->next_frame_x_offset); ++ return (0); ++} ++ ++png_uint_32 PNGAPI ++png_get_next_frame_y_offset(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_debug(1, "in png_get_next_frame_y_offset()"); ++ ++ if (png_ptr != NULL && info_ptr != NULL) ++ return (info_ptr->next_frame_y_offset); ++ return (0); ++} ++ ++png_uint_16 PNGAPI ++png_get_next_frame_delay_num(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_debug(1, "in png_get_next_frame_delay_num()"); ++ ++ if (png_ptr != NULL && info_ptr != NULL) ++ return (info_ptr->next_frame_delay_num); ++ return (0); ++} ++ ++png_uint_16 PNGAPI ++png_get_next_frame_delay_den(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_debug(1, "in png_get_next_frame_delay_den()"); ++ ++ if (png_ptr != NULL && info_ptr != NULL) ++ return (info_ptr->next_frame_delay_den); ++ return (0); ++} ++ ++png_byte PNGAPI ++png_get_next_frame_dispose_op(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_debug(1, "in png_get_next_frame_dispose_op()"); ++ ++ if (png_ptr != NULL && info_ptr != NULL) ++ return (info_ptr->next_frame_dispose_op); ++ return (0); ++} ++ ++png_byte PNGAPI ++png_get_next_frame_blend_op(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_debug(1, "in png_get_next_frame_blend_op()"); ++ ++ if (png_ptr != NULL && info_ptr != NULL) ++ return (info_ptr->next_frame_blend_op); ++ return (0); ++} ++ ++png_byte PNGAPI ++png_get_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_debug(1, "in png_first_frame_is_hidden()"); ++ ++ if (png_ptr != NULL) ++ return (png_byte)(png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN); ++ ++ PNG_UNUSED(info_ptr) ++ ++ return 0; ++} ++#endif /* APNG */ + #endif /* READ || WRITE */ +diff --git a/pnginfo.h b/pnginfo.h +--- a/pnginfo.h ++++ b/pnginfo.h +@@ -262,6 +262,19 @@ defined(PNG_READ_BACKGROUND_SUPPORTED) + /* Data valid if (valid & PNG_INFO_IDAT) non-zero */ + png_bytepp row_pointers; /* the image bits */ + #endif + ++#ifdef PNG_APNG_SUPPORTED ++ png_uint_32 num_frames; /* including default image */ ++ png_uint_32 num_plays; ++ png_uint_32 next_frame_width; ++ png_uint_32 next_frame_height; ++ png_uint_32 next_frame_x_offset; ++ png_uint_32 next_frame_y_offset; ++ png_uint_16 next_frame_delay_num; ++ png_uint_16 next_frame_delay_den; ++ png_byte next_frame_dispose_op; ++ png_byte next_frame_blend_op; ++#endif ++ + }; + #endif /* PNGINFO_H */ +diff --git a/pngpread.c b/pngpread.c +--- a/pngpread.c ++++ b/pngpread.c +@@ -194,8 +194,91 @@ png_push_read_chunk(png_structrp png_ptr + } + + chunk_name = png_ptr->chunk_name; + ++#ifdef PNG_READ_APNG_SUPPORTED ++ if (png_ptr->num_frames_read > 0 && ++ png_ptr->num_frames_read < info_ptr->num_frames) ++ { ++ if (chunk_name == png_IDAT) ++ { ++ /* Discard trailing IDATs for the first frame */ ++ if ((png_ptr->mode & PNG_HAVE_fcTL) != 0 || ++ png_ptr->num_frames_read > 1) ++ png_error(png_ptr, "out of place IDAT"); ++ ++ PNG_PUSH_SAVE_BUFFER_IF_FULL ++ png_crc_finish(png_ptr, png_ptr->push_length); ++ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; ++ } ++ ++ else if (chunk_name == png_fdAT) ++ { ++ PNG_PUSH_SAVE_BUFFER_IF_LT(4) ++ png_ensure_sequence_number(png_ptr, 4); ++ ++ if ((png_ptr->mode & PNG_HAVE_fcTL) == 0) ++ { ++ /* Discard trailing fdATs for frames other than the first */ ++ if (png_ptr->num_frames_read < 2) ++ png_error(png_ptr, "out of place fdAT"); ++ ++ PNG_PUSH_SAVE_BUFFER_IF_FULL ++ png_crc_finish(png_ptr, png_ptr->push_length); ++ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; ++ } ++ ++ else ++ { ++ /* frame data follows */ ++ png_ptr->idat_size = png_ptr->push_length - 4; ++ png_ptr->mode |= PNG_HAVE_IDAT; ++ png_ptr->process_mode = PNG_READ_IDAT_MODE; ++ } ++ } ++ ++ else if (chunk_name == png_fcTL) ++ { ++ PNG_PUSH_SAVE_BUFFER_IF_FULL ++ png_read_reset(png_ptr); ++ png_ptr->mode &= ~PNG_HAVE_fcTL; ++ ++ png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length); ++ ++ if ((png_ptr->mode & PNG_HAVE_fcTL) == 0) ++ png_error(png_ptr, "missing required fcTL chunk"); ++ ++ png_read_reinit(png_ptr, info_ptr); ++ png_progressive_read_reset(png_ptr); ++ ++ if (png_ptr->frame_info_fn != NULL) ++ (*(png_ptr->frame_info_fn))(png_ptr, png_ptr->num_frames_read); ++ ++ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; ++ } ++ ++ else if (chunk_name == png_IEND) ++ { ++ PNG_PUSH_SAVE_BUFFER_IF_FULL ++ png_warning(png_ptr, "Number of actual frames fewer than expected"); ++ png_crc_finish(png_ptr, png_ptr->push_length); ++ png_ptr->process_mode = PNG_READ_DONE_MODE; ++ png_push_have_end(png_ptr, info_ptr); ++ } ++ ++ else ++ { ++ PNG_PUSH_SAVE_BUFFER_IF_FULL ++ png_warning(png_ptr, "Skipped (ignored) a chunk " ++ "between APNG chunks"); ++ png_crc_finish(png_ptr, png_ptr->push_length); ++ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; ++ } ++ ++ return; ++ } ++#endif /* READ_APNG */ ++ + if (chunk_name == png_IDAT) + { + if ((png_ptr->mode & PNG_AFTER_IDAT) != 0) + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; +@@ -260,8 +343,11 @@ png_push_read_chunk(png_structrp png_ptr + } + + else if (chunk_name == png_IDAT) + { ++#ifdef PNG_READ_APNG_SUPPORTED ++ png_have_info(png_ptr, info_ptr); ++#endif + png_ptr->idat_size = png_ptr->push_length; + png_ptr->process_mode = PNG_READ_IDAT_MODE; + png_push_have_info(png_ptr, info_ptr); + png_ptr->zstream.avail_out = +@@ -406,8 +492,22 @@ png_push_read_chunk(png_structrp png_ptr + png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); + } + #endif + ++#ifdef PNG_READ_APNG_SUPPORTED ++ else if (chunk_name == png_acTL) ++ { ++ PNG_PUSH_SAVE_BUFFER_IF_FULL ++ png_handle_acTL(png_ptr, info_ptr, png_ptr->push_length); ++ } ++ ++ else if (chunk_name == png_fcTL) ++ { ++ PNG_PUSH_SAVE_BUFFER_IF_FULL ++ png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length); ++ } ++ ++#endif /* READ_APNG */ + else + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, +@@ -538,27 +638,74 @@ png_push_read_IDAT(png_structrp png_ptr) + png_byte chunk_length[4]; + png_byte chunk_tag[4]; + + /* TODO: this code can be commoned up with the same code in push_read */ ++#ifdef PNG_READ_APNG_SUPPORTED ++ PNG_PUSH_SAVE_BUFFER_IF_LT(12) ++#else + PNG_PUSH_SAVE_BUFFER_IF_LT(8) ++#endif + png_push_fill_buffer(png_ptr, chunk_length, 4); + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); + png_reset_crc(png_ptr); + png_crc_read(png_ptr, chunk_tag, 4); + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; + ++#ifdef PNG_READ_APNG_SUPPORTED ++ if (png_ptr->chunk_name != png_fdAT && png_ptr->num_frames_read > 0) ++ { ++ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) != 0) ++ { ++ png_ptr->process_mode = PNG_READ_CHUNK_MODE; ++ if (png_ptr->frame_end_fn != NULL) ++ (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read); ++ png_ptr->num_frames_read++; ++ return; ++ } ++ else ++ { ++ if (png_ptr->chunk_name == png_IEND) ++ png_error(png_ptr, "Not enough image data"); ++ PNG_PUSH_SAVE_BUFFER_IF_FULL ++ png_warning(png_ptr, "Skipping (ignoring) a chunk between " ++ "APNG chunks"); ++ png_crc_finish(png_ptr, png_ptr->push_length); ++ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; ++ return; ++ } ++ } ++ else ++#endif ++#ifdef PNG_READ_APNG_SUPPORTED ++ if (png_ptr->chunk_name != png_IDAT && png_ptr->num_frames_read == 0) ++#else + if (png_ptr->chunk_name != png_IDAT) ++#endif + { + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) + png_error(png_ptr, "Not enough compressed data"); + ++#ifdef PNG_READ_APNG_SUPPORTED ++ if (png_ptr->frame_end_fn != NULL) ++ (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read); ++ png_ptr->num_frames_read++; ++#endif ++ + return; + } + + png_ptr->idat_size = png_ptr->push_length; ++ ++#ifdef PNG_READ_APNG_SUPPORTED ++ if (png_ptr->num_frames_read > 0) ++ { ++ png_ensure_sequence_number(png_ptr, 4); ++ png_ptr->idat_size -= 4; ++ } ++#endif + } + + if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0) + { +@@ -630,8 +777,18 @@ png_process_IDAT_data(png_structrp png_p + /* The caller checks for a non-zero buffer length. */ + if (!(buffer_length > 0) || buffer == NULL) + png_error(png_ptr, "No IDAT data (internal error)"); + ++#ifdef PNG_READ_APNG_SUPPORTED ++ /* If the app is not APNG-aware, decode only the first frame */ ++ if ((png_ptr->apng_flags & PNG_APNG_APP) == 0 && ++ png_ptr->num_frames_read > 0) ++ { ++ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; ++ return; ++ } ++#endif ++ + /* This routine must process all the data it has been given + * before returning, calling the row callback as required to + * handle the uncompressed results. + */ +@@ -1084,8 +1241,20 @@ png_set_progressive_read_fn(png_structrp + + png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); + } + ++#ifdef PNG_READ_APNG_SUPPORTED ++void PNGAPI ++png_set_progressive_frame_fn(png_structp png_ptr, ++ png_progressive_frame_ptr frame_info_fn, ++ png_progressive_frame_ptr frame_end_fn) ++{ ++ png_ptr->frame_info_fn = frame_info_fn; ++ png_ptr->frame_end_fn = frame_end_fn; ++ png_ptr->apng_flags |= PNG_APNG_APP; ++} ++#endif ++ + png_voidp PNGAPI + png_get_progressive_ptr(png_const_structrp png_ptr) + { + if (png_ptr == NULL) +diff --git a/pngpriv.h b/pngpriv.h +--- a/pngpriv.h ++++ b/pngpriv.h +@@ -636,8 +636,12 @@ + #define PNG_HAVE_PNG_SIGNATURE 0x1000U + #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */ + /* 0x4000U (unused) */ + #define PNG_IS_READ_STRUCT 0x8000U /* Else is a write struct */ ++#ifdef PNG_APNG_SUPPORTED ++#define PNG_HAVE_acTL 0x10000U ++#define PNG_HAVE_fcTL 0x20000U ++#endif + + /* Flags for the transformations the PNG library does on the image data */ + #define PNG_BGR 0x0001U + #define PNG_INTERLACE 0x0002U +@@ -872,8 +876,18 @@ + #define png_tIME PNG_U32(116, 73, 77, 69) + #define png_tRNS PNG_U32(116, 82, 78, 83) + #define png_zTXt PNG_U32(122, 84, 88, 116) + ++#ifdef PNG_APNG_SUPPORTED ++#define png_acTL PNG_U32( 97, 99, 84, 76) ++#define png_fcTL PNG_U32(102, 99, 84, 76) ++#define png_fdAT PNG_U32(102, 100, 65, 84) ++ ++/* For png_struct.apng_flags: */ ++#define PNG_FIRST_FRAME_HIDDEN 0x0001U ++#define PNG_APNG_APP 0x0002U ++#endif ++ + /* The following will work on (signed char*) strings, whereas the get_uint_32 + * macro will fail on top-bit-set values because of the sign extension. + */ + #define PNG_CHUNK_FROM_STRING(s)\ +@@ -1623,8 +1637,51 @@ PNG_INTERNAL_FUNCTION(void,png_push_read + # endif + + #endif /* PROGRESSIVE_READ */ + ++#ifdef PNG_APNG_SUPPORTED ++PNG_INTERNAL_FUNCTION(void,png_ensure_fcTL_is_valid,(png_structp png_ptr, ++ png_uint_32 width, png_uint_32 height, ++ png_uint_32 x_offset, png_uint_32 y_offset, ++ png_uint_16 delay_num, png_uint_16 delay_den, ++ png_byte dispose_op, png_byte blend_op),PNG_EMPTY); ++ ++#ifdef PNG_READ_APNG_SUPPORTED ++PNG_INTERNAL_FUNCTION(void,png_handle_acTL,(png_structp png_ptr, ++ png_infop info_ptr, png_uint_32 length),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_handle_fcTL,(png_structp png_ptr, ++ png_infop info_ptr, png_uint_32 length),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_handle_fdAT,(png_structp png_ptr, ++ png_infop info_ptr, png_uint_32 length),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_have_info,(png_structp png_ptr, ++ png_infop info_ptr),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_ensure_sequence_number,(png_structp png_ptr, ++ png_uint_32 length),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_read_reset,(png_structp png_ptr),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_read_reinit,(png_structp png_ptr, ++ png_infop info_ptr),PNG_EMPTY); ++#ifdef PNG_PROGRESSIVE_READ_SUPPORTED ++PNG_INTERNAL_FUNCTION(void,png_progressive_read_reset,(png_structp png_ptr), ++ PNG_EMPTY); ++#endif /* PROGRESSIVE_READ */ ++#endif /* READ_APNG */ ++ ++#ifdef PNG_WRITE_APNG_SUPPORTED ++PNG_INTERNAL_FUNCTION(void,png_write_acTL,(png_structp png_ptr, ++ png_uint_32 num_frames, png_uint_32 num_plays),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_write_fcTL,(png_structp png_ptr, ++ png_uint_32 width, png_uint_32 height, ++ png_uint_32 x_offset, png_uint_32 y_offset, ++ png_uint_16 delay_num, png_uint_16 delay_den, ++ png_byte dispose_op, png_byte blend_op),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_write_fdAT,(png_structp png_ptr, ++ png_const_bytep data, png_size_t length),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_write_reset,(png_structp png_ptr),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_write_reinit,(png_structp png_ptr, ++ png_infop info_ptr, png_uint_32 width, png_uint_32 height),PNG_EMPTY); ++#endif /* WRITE_APNG */ ++#endif /* APNG */ ++ + /* Added at libpng version 1.6.0 */ + #ifdef PNG_GAMMA_SUPPORTED + PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY); +diff --git a/pngread.c b/pngread.c +--- a/pngread.c ++++ b/pngread.c +@@ -160,8 +160,11 @@ png_read_info(png_structrp png_ptr, png_ + png_handle_PLTE(png_ptr, info_ptr, length); + + else if (chunk_name == png_IDAT) + { ++#ifdef PNG_READ_APNG_SUPPORTED ++ png_have_info(png_ptr, info_ptr); ++#endif + png_ptr->idat_size = length; + break; + } + +@@ -254,15 +257,92 @@ png_read_info(png_structrp png_ptr, png_ + else if (chunk_name == png_iTXt) + png_handle_iTXt(png_ptr, info_ptr, length); + #endif + ++#ifdef PNG_READ_APNG_SUPPORTED ++ else if (chunk_name == png_acTL) ++ png_handle_acTL(png_ptr, info_ptr, length); ++ ++ else if (chunk_name == png_fcTL) ++ png_handle_fcTL(png_ptr, info_ptr, length); ++ ++ else if (chunk_name == png_fdAT) ++ png_handle_fdAT(png_ptr, info_ptr, length); ++#endif ++ + else + png_handle_unknown(png_ptr, info_ptr, length, + PNG_HANDLE_CHUNK_AS_DEFAULT); + } + } + #endif /* SEQUENTIAL_READ */ + ++#ifdef PNG_READ_APNG_SUPPORTED ++void PNGAPI ++png_read_frame_head(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_byte have_chunk_after_DAT; /* after IDAT or after fdAT */ ++ ++ png_debug(0, "Reading frame head"); ++ ++ if ((png_ptr->mode & PNG_HAVE_acTL) == 0) ++ png_error(png_ptr, "attempt to png_read_frame_head() but " ++ "no acTL present"); ++ ++ /* do nothing for the main IDAT */ ++ if (png_ptr->num_frames_read == 0) ++ return; ++ ++ png_read_reset(png_ptr); ++ png_ptr->flags &= ~PNG_FLAG_ROW_INIT; ++ png_ptr->mode &= ~PNG_HAVE_fcTL; ++ ++ have_chunk_after_DAT = 0; ++ for (;;) ++ { ++ png_uint_32 length = png_read_chunk_header(png_ptr); ++ ++ if (png_ptr->chunk_name == png_IDAT) ++ { ++ /* discard trailing IDATs for the first frame */ ++ if (have_chunk_after_DAT != 0 || png_ptr->num_frames_read > 1) ++ png_error(png_ptr, "png_read_frame_head(): out of place IDAT"); ++ png_crc_finish(png_ptr, length); ++ } ++ ++ else if (png_ptr->chunk_name == png_fcTL) ++ { ++ png_handle_fcTL(png_ptr, info_ptr, length); ++ have_chunk_after_DAT = 1; ++ } ++ ++ else if (png_ptr->chunk_name == png_fdAT) ++ { ++ png_ensure_sequence_number(png_ptr, length); ++ ++ /* discard trailing fdATs for frames other than the first */ ++ if (have_chunk_after_DAT == 0 && png_ptr->num_frames_read > 1) ++ png_crc_finish(png_ptr, length - 4); ++ else if (png_ptr->mode & PNG_HAVE_fcTL) ++ { ++ png_ptr->idat_size = length - 4; ++ png_ptr->mode |= PNG_HAVE_IDAT; ++ ++ break; ++ } ++ else ++ png_error(png_ptr, "png_read_frame_head(): out of place fdAT"); ++ } ++ else ++ { ++ png_warning(png_ptr, "Skipped (ignored) a chunk " ++ "between APNG chunks"); ++ png_crc_finish(png_ptr, length); ++ } ++ } ++} ++#endif /* READ_APNG */ ++ + /* Optional call to update the users info_ptr structure */ + void PNGAPI + png_read_update_info(png_structrp png_ptr, png_inforp info_ptr) + { +diff --git a/pngrutil.c b/pngrutil.c +--- a/pngrutil.c ++++ b/pngrutil.c +@@ -864,8 +864,13 @@ png_handle_IHDR(png_structrp png_ptr, pn + compression_type = buf[10]; + filter_type = buf[11]; + interlace_type = buf[12]; + ++#ifdef PNG_READ_APNG_SUPPORTED ++ png_ptr->first_frame_width = width; ++ png_ptr->first_frame_height = height; ++#endif ++ + /* Set internal variables */ + png_ptr->width = width; + png_ptr->height = height; + png_ptr->bit_depth = (png_byte)bit_depth; +@@ -2856,8 +2861,182 @@ png_handle_iTXt(png_structrp png_ptr, pn + png_chunk_benign_error(png_ptr, errmsg); + } + #endif + ++#ifdef PNG_READ_APNG_SUPPORTED ++void /* PRIVATE */ ++png_handle_acTL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) ++{ ++ png_byte data[8]; ++ png_uint_32 num_frames; ++ png_uint_32 num_plays; ++ png_uint_32 didSet; ++ ++ png_debug(1, "in png_handle_acTL"); ++ ++ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) ++ { ++ png_error(png_ptr, "Missing IHDR before acTL"); ++ } ++ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) ++ { ++ png_warning(png_ptr, "Invalid acTL after IDAT skipped"); ++ png_crc_finish(png_ptr, length); ++ return; ++ } ++ else if ((png_ptr->mode & PNG_HAVE_acTL) != 0) ++ { ++ png_warning(png_ptr, "Duplicate acTL skipped"); ++ png_crc_finish(png_ptr, length); ++ return; ++ } ++ else if (length != 8) ++ { ++ png_warning(png_ptr, "acTL with invalid length skipped"); ++ png_crc_finish(png_ptr, length); ++ return; ++ } ++ ++ png_crc_read(png_ptr, data, 8); ++ png_crc_finish(png_ptr, 0); ++ ++ num_frames = png_get_uint_31(png_ptr, data); ++ num_plays = png_get_uint_31(png_ptr, data + 4); ++ ++ /* the set function will do error checking on num_frames */ ++ didSet = png_set_acTL(png_ptr, info_ptr, num_frames, num_plays); ++ if (didSet != 0) ++ png_ptr->mode |= PNG_HAVE_acTL; ++} ++ ++void /* PRIVATE */ ++png_handle_fcTL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) ++{ ++ png_byte data[22]; ++ png_uint_32 width; ++ png_uint_32 height; ++ png_uint_32 x_offset; ++ png_uint_32 y_offset; ++ png_uint_16 delay_num; ++ png_uint_16 delay_den; ++ png_byte dispose_op; ++ png_byte blend_op; ++ ++ png_debug(1, "in png_handle_fcTL"); ++ ++ png_ensure_sequence_number(png_ptr, length); ++ ++ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) ++ { ++ png_error(png_ptr, "Missing IHDR before fcTL"); ++ } ++ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) ++ { ++ /* for any frames other then the first this message may be misleading, ++ * but correct. PNG_HAVE_IDAT is unset before the frame head is read ++ * i can't think of a better message */ ++ png_warning(png_ptr, "Invalid fcTL after IDAT skipped"); ++ png_crc_finish(png_ptr, length-4); ++ return; ++ } ++ else if ((png_ptr->mode & PNG_HAVE_fcTL) != 0) ++ { ++ png_warning(png_ptr, "Duplicate fcTL within one frame skipped"); ++ png_crc_finish(png_ptr, length-4); ++ return; ++ } ++ else if (length != 26) ++ { ++ png_warning(png_ptr, "fcTL with invalid length skipped"); ++ png_crc_finish(png_ptr, length-4); ++ return; ++ } ++ ++ png_crc_read(png_ptr, data, 22); ++ png_crc_finish(png_ptr, 0); ++ ++ width = png_get_uint_31(png_ptr, data); ++ height = png_get_uint_31(png_ptr, data + 4); ++ x_offset = png_get_uint_31(png_ptr, data + 8); ++ y_offset = png_get_uint_31(png_ptr, data + 12); ++ delay_num = png_get_uint_16(data + 16); ++ delay_den = png_get_uint_16(data + 18); ++ dispose_op = data[20]; ++ blend_op = data[21]; ++ ++ if (png_ptr->num_frames_read == 0 && (x_offset != 0 || y_offset != 0)) ++ { ++ png_warning(png_ptr, "fcTL for the first frame must have zero offset"); ++ return; ++ } ++ ++ if (info_ptr != NULL) ++ { ++ if (png_ptr->num_frames_read == 0 && ++ (width != info_ptr->width || height != info_ptr->height)) ++ { ++ png_warning(png_ptr, "size in first frame's fcTL must match " ++ "the size in IHDR"); ++ return; ++ } ++ ++ /* The set function will do more error checking */ ++ png_set_next_frame_fcTL(png_ptr, info_ptr, width, height, ++ x_offset, y_offset, delay_num, delay_den, ++ dispose_op, blend_op); ++ ++ png_read_reinit(png_ptr, info_ptr); ++ ++ png_ptr->mode |= PNG_HAVE_fcTL; ++ } ++} ++ ++void /* PRIVATE */ ++png_have_info(png_structp png_ptr, png_infop info_ptr) ++{ ++ if ((info_ptr->valid & PNG_INFO_acTL) != 0 && ++ (info_ptr->valid & PNG_INFO_fcTL) == 0) ++ { ++ png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN; ++ info_ptr->num_frames++; ++ } ++} ++ ++void /* PRIVATE */ ++png_handle_fdAT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) ++{ ++ png_ensure_sequence_number(png_ptr, length); ++ ++ /* This function is only called from png_read_end(), png_read_info(), ++ * and png_push_read_chunk() which means that: ++ * - the user doesn't want to read this frame ++ * - or this is an out-of-place fdAT ++ * in either case it is safe to ignore the chunk with a warning */ ++ png_warning(png_ptr, "ignoring fdAT chunk"); ++ png_crc_finish(png_ptr, length - 4); ++ PNG_UNUSED(info_ptr) ++} ++ ++void /* PRIVATE */ ++png_ensure_sequence_number(png_structp png_ptr, png_uint_32 length) ++{ ++ png_byte data[4]; ++ png_uint_32 sequence_number; ++ ++ if (length < 4) ++ png_error(png_ptr, "invalid fcTL or fdAT chunk found"); ++ ++ png_crc_read(png_ptr, data, 4); ++ sequence_number = png_get_uint_31(png_ptr, data); ++ ++ if (sequence_number != png_ptr->next_seq_num) ++ png_error(png_ptr, "fcTL or fdAT chunk with out-of-order sequence " ++ "number found"); ++ ++ png_ptr->next_seq_num++; ++} ++#endif /* READ_APNG */ ++ + #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED + /* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */ + static int + png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length) +@@ -3161,9 +3340,13 @@ png_check_chunk_length(png_const_structr + # elif PNG_USER_CHUNK_MALLOC_MAX > 0 + if (PNG_USER_CHUNK_MALLOC_MAX < limit) + limit = PNG_USER_CHUNK_MALLOC_MAX; + # endif ++#ifdef PNG_READ_APNG_SUPPORTED ++ if (png_ptr->chunk_name == png_IDAT || png_ptr->chunk_name == png_fdAT) ++#else + if (png_ptr->chunk_name == png_IDAT) ++#endif + { + png_alloc_size_t idat_limit = PNG_UINT_31_MAX; + size_t row_factor = + (size_t)png_ptr->width +@@ -4165,8 +4348,40 @@ png_read_IDAT_data(png_structrp png_ptr, + { + uInt avail_in; + png_bytep buffer; + ++#ifdef PNG_READ_APNG_SUPPORTED ++ png_uint_32 bytes_to_skip = 0; ++ ++ while (png_ptr->idat_size == 0 || bytes_to_skip != 0) ++ { ++ png_crc_finish(png_ptr, bytes_to_skip); ++ bytes_to_skip = 0; ++ ++ png_ptr->idat_size = png_read_chunk_header(png_ptr); ++ if (png_ptr->num_frames_read == 0) ++ { ++ if (png_ptr->chunk_name != png_IDAT) ++ png_error(png_ptr, "Not enough image data"); ++ } ++ else ++ { ++ if (png_ptr->chunk_name == png_IEND) ++ png_error(png_ptr, "Not enough image data"); ++ if (png_ptr->chunk_name != png_fdAT) ++ { ++ png_warning(png_ptr, "Skipped (ignored) a chunk " ++ "between APNG chunks"); ++ bytes_to_skip = png_ptr->idat_size; ++ continue; ++ } ++ ++ png_ensure_sequence_number(png_ptr, png_ptr->idat_size); ++ ++ png_ptr->idat_size -= 4; ++ } ++ } ++#else + while (png_ptr->idat_size == 0) + { + png_crc_finish(png_ptr, 0); + +@@ -4176,8 +4391,9 @@ png_read_IDAT_data(png_structrp png_ptr, + */ + if (png_ptr->chunk_name != png_IDAT) + png_error(png_ptr, "Not enough image data"); + } ++#endif /* READ_APNG */ + + avail_in = png_ptr->IDAT_read_size; + + if (avail_in > png_ptr->idat_size) +@@ -4239,8 +4455,11 @@ png_read_IDAT_data(png_structrp png_ptr, + png_ptr->zstream.next_out = NULL; + + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; ++#ifdef PNG_READ_APNG_SUPPORTED ++ png_ptr->num_frames_read++; ++#endif + + if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0) + png_chunk_benign_error(png_ptr, "Extra compressed data"); + break; +@@ -4677,5 +4896,81 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED + png_error(png_ptr, png_ptr->zstream.msg); + + png_ptr->flags |= PNG_FLAG_ROW_INIT; + } ++ ++#ifdef PNG_READ_APNG_SUPPORTED ++/* This function is to be called after the main IDAT set has been read and ++ * before a new IDAT is read. It resets some parts of png_ptr ++ * to make them usable by the read functions again */ ++void /* PRIVATE */ ++png_read_reset(png_structp png_ptr) ++{ ++ png_ptr->mode &= ~PNG_HAVE_IDAT; ++ png_ptr->mode &= ~PNG_AFTER_IDAT; ++ png_ptr->row_number = 0; ++ png_ptr->pass = 0; ++} ++ ++void /* PRIVATE */ ++png_read_reinit(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_ptr->width = info_ptr->next_frame_width; ++ png_ptr->height = info_ptr->next_frame_height; ++ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->width); ++ png_ptr->info_rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, ++ png_ptr->width); ++ if (png_ptr->prev_row != NULL) ++ memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); ++} ++ ++#ifdef PNG_PROGRESSIVE_READ_SUPPORTED ++/* same as png_read_reset() but for the progressive reader */ ++void /* PRIVATE */ ++png_progressive_read_reset(png_structp png_ptr) ++{ ++#ifdef PNG_READ_INTERLACING_SUPPORTED ++ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ ++ ++ /* Start of interlace block */ ++ static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; ++ ++ /* Offset to next interlace block */ ++ static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; ++ ++ /* Start of interlace block in the y direction */ ++ static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; ++ ++ /* Offset to next interlace block in the y direction */ ++ static PNG_CONST png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; ++ ++ if (png_ptr->interlaced != 0) ++ { ++ if ((png_ptr->transformations & PNG_INTERLACE) == 0) ++ png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - ++ png_pass_ystart[0]) / png_pass_yinc[0]; ++ else ++ png_ptr->num_rows = png_ptr->height; ++ ++ png_ptr->iwidth = (png_ptr->width + ++ png_pass_inc[png_ptr->pass] - 1 - ++ png_pass_start[png_ptr->pass]) / ++ png_pass_inc[png_ptr->pass]; ++ } ++ else ++#endif /* READ_INTERLACING */ ++ { ++ png_ptr->num_rows = png_ptr->height; ++ png_ptr->iwidth = png_ptr->width; ++ } ++ png_ptr->flags &= ~PNG_FLAG_ZSTREAM_ENDED; ++ if (inflateReset(&(png_ptr->zstream)) != Z_OK) ++ png_error(png_ptr, "inflateReset failed"); ++ png_ptr->zstream.avail_in = 0; ++ png_ptr->zstream.next_in = 0; ++ png_ptr->zstream.next_out = png_ptr->row_buf; ++ png_ptr->zstream.avail_out = (uInt)PNG_ROWBYTES(png_ptr->pixel_depth, ++ png_ptr->iwidth) + 1; ++} ++#endif /* PROGRESSIVE_READ */ ++#endif /* READ_APNG */ + #endif /* READ */ +diff --git a/pngset.c b/pngset.c +--- a/pngset.c ++++ b/pngset.c +@@ -287,8 +287,13 @@ png_set_IHDR(png_const_structrp png_ptr, + + info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth); + + info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width); ++ ++#ifdef PNG_APNG_SUPPORTED ++ /* for non-animated png. this may be overwritten from an acTL chunk later */ ++ info_ptr->num_frames = 1; ++#endif + } + + #ifdef PNG_oFFs_SUPPORTED + void PNGAPI +@@ -1157,8 +1162,148 @@ png_set_sPLT(png_const_structrp png_ptr, + png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR); + } + #endif /* sPLT */ + ++#ifdef PNG_APNG_SUPPORTED ++png_uint_32 PNGAPI ++png_set_acTL(png_structp png_ptr, png_infop info_ptr, ++ png_uint_32 num_frames, png_uint_32 num_plays) ++{ ++ png_debug1(1, "in %s storage function", "acTL"); ++ ++ if (png_ptr == NULL || info_ptr == NULL) ++ { ++ png_warning(png_ptr, ++ "Call to png_set_acTL() with NULL png_ptr " ++ "or info_ptr ignored"); ++ return (0); ++ } ++ if (num_frames == 0) ++ { ++ png_warning(png_ptr, ++ "Ignoring attempt to set acTL with num_frames zero"); ++ return (0); ++ } ++ if (num_frames > PNG_UINT_31_MAX) ++ { ++ png_warning(png_ptr, ++ "Ignoring attempt to set acTL with num_frames > 2^31-1"); ++ return (0); ++ } ++ if (num_plays > PNG_UINT_31_MAX) ++ { ++ png_warning(png_ptr, ++ "Ignoring attempt to set acTL with num_plays > 2^31-1"); ++ return (0); ++ } ++ ++ info_ptr->num_frames = num_frames; ++ info_ptr->num_plays = num_plays; ++ ++ info_ptr->valid |= PNG_INFO_acTL; ++ ++ return (1); ++} ++ ++/* delay_num and delay_den can hold any 16-bit values including zero */ ++png_uint_32 PNGAPI ++png_set_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr, ++ png_uint_32 width, png_uint_32 height, ++ png_uint_32 x_offset, png_uint_32 y_offset, ++ png_uint_16 delay_num, png_uint_16 delay_den, ++ png_byte dispose_op, png_byte blend_op) ++{ ++ png_debug1(1, "in %s storage function", "fcTL"); ++ ++ if (png_ptr == NULL || info_ptr == NULL) ++ { ++ png_warning(png_ptr, ++ "Call to png_set_fcTL() with NULL png_ptr or info_ptr " ++ "ignored"); ++ return (0); ++ } ++ ++ png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset, ++ delay_num, delay_den, dispose_op, blend_op); ++ ++ if (blend_op == PNG_BLEND_OP_OVER) ++ { ++ if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0 && ++ png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) == 0) ++ { ++ png_warning(png_ptr, "PNG_BLEND_OP_OVER is meaningless " ++ "and wasteful for opaque images, ignored"); ++ blend_op = PNG_BLEND_OP_SOURCE; ++ } ++ } ++ ++ info_ptr->next_frame_width = width; ++ info_ptr->next_frame_height = height; ++ info_ptr->next_frame_x_offset = x_offset; ++ info_ptr->next_frame_y_offset = y_offset; ++ info_ptr->next_frame_delay_num = delay_num; ++ info_ptr->next_frame_delay_den = delay_den; ++ info_ptr->next_frame_dispose_op = dispose_op; ++ info_ptr->next_frame_blend_op = blend_op; ++ ++ info_ptr->valid |= PNG_INFO_fcTL; ++ ++ return (1); ++} ++ ++void /* PRIVATE */ ++png_ensure_fcTL_is_valid(png_structp png_ptr, ++ png_uint_32 width, png_uint_32 height, ++ png_uint_32 x_offset, png_uint_32 y_offset, ++ png_uint_16 delay_num, png_uint_16 delay_den, ++ png_byte dispose_op, png_byte blend_op) ++{ ++ if (width == 0 || width > PNG_UINT_31_MAX) ++ png_error(png_ptr, "invalid width in fcTL (0 or > 2^31-1)"); ++ if (height == 0 || height > PNG_UINT_31_MAX) ++ png_error(png_ptr, "invalid height in fcTL (0 or > 2^31-1)"); ++ if (x_offset > PNG_UINT_31_MAX) ++ png_error(png_ptr, "invalid x_offset in fcTL (> 2^31-1)"); ++ if (y_offset > PNG_UINT_31_MAX) ++ png_error(png_ptr, "invalid y_offset in fcTL (> 2^31-1)"); ++ if (width + x_offset > png_ptr->first_frame_width || ++ height + y_offset > png_ptr->first_frame_height) ++ png_error(png_ptr, "dimensions of a frame are greater than " ++ "the ones in IHDR"); ++ ++ if (dispose_op != PNG_DISPOSE_OP_NONE && ++ dispose_op != PNG_DISPOSE_OP_BACKGROUND && ++ dispose_op != PNG_DISPOSE_OP_PREVIOUS) ++ png_error(png_ptr, "invalid dispose_op in fcTL"); ++ ++ if (blend_op != PNG_BLEND_OP_SOURCE && ++ blend_op != PNG_BLEND_OP_OVER) ++ png_error(png_ptr, "invalid blend_op in fcTL"); ++ ++ PNG_UNUSED(delay_num) ++ PNG_UNUSED(delay_den) ++} ++ ++png_uint_32 PNGAPI ++png_set_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr, ++ png_byte is_hidden) ++{ ++ png_debug(1, "in png_first_frame_is_hidden()"); ++ ++ if (png_ptr == NULL) ++ return 0; ++ ++ if (is_hidden != 0) ++ png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN; ++ else ++ png_ptr->apng_flags &= ~PNG_FIRST_FRAME_HIDDEN; ++ ++ PNG_UNUSED(info_ptr) ++ ++ return 1; ++} ++#endif /* APNG */ ++ + #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED + static png_byte + check_location(png_const_structrp png_ptr, int location) + { +diff --git a/pngstruct.h b/pngstruct.h +--- a/pngstruct.h ++++ b/pngstruct.h +@@ -408,8 +408,29 @@ struct png_struct_def + #ifdef PNG_MNG_FEATURES_SUPPORTED + png_byte filter_type; + #endif + ++#ifdef PNG_APNG_SUPPORTED ++ png_uint_32 apng_flags; ++ png_uint_32 next_seq_num; /* next fcTL/fdAT chunk sequence number */ ++ png_uint_32 first_frame_width; ++ png_uint_32 first_frame_height; ++ ++#ifdef PNG_READ_APNG_SUPPORTED ++ png_uint_32 num_frames_read; /* incremented after all image data of */ ++ /* a frame is read */ ++#ifdef PNG_PROGRESSIVE_READ_SUPPORTED ++ png_progressive_frame_ptr frame_info_fn; /* frame info read callback */ ++ png_progressive_frame_ptr frame_end_fn; /* frame data read callback */ ++#endif ++#endif ++ ++#ifdef PNG_WRITE_APNG_SUPPORTED ++ png_uint_32 num_frames_to_write; ++ png_uint_32 num_frames_written; ++#endif ++#endif /* APNG */ ++ + /* New members added in libpng-1.2.0 */ + + /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */ + #ifdef PNG_USER_MEM_SUPPORTED +diff --git a/pngwrite.c b/pngwrite.c +--- a/pngwrite.c ++++ b/pngwrite.c +@@ -127,8 +127,12 @@ png_write_info_before_PLTE(png_structrp + * an error and calls png_error while the color space is being set, yet + * the application continues writing the PNG. So check the 'invalid' + * flag here too. + */ ++#ifdef PNG_WRITE_APNG_SUPPORTED ++ if ((info_ptr->valid & PNG_INFO_acTL) != 0) ++ png_write_acTL(png_ptr, info_ptr->num_frames, info_ptr->num_plays); ++#endif + #ifdef PNG_GAMMA_SUPPORTED + # ifdef PNG_WRITE_gAMA_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) != 0 && +@@ -364,8 +368,13 @@ png_write_end(png_structrp png_ptr, png_ + + if ((png_ptr->mode & PNG_HAVE_IDAT) == 0) + png_error(png_ptr, "No IDATs written into file"); + ++#ifdef PNG_WRITE_APNG_SUPPORTED ++ if (png_ptr->num_frames_written != png_ptr->num_frames_to_write) ++ png_error(png_ptr, "Not enough frames written"); ++#endif ++ + #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED + if (png_ptr->num_palette_max > png_ptr->num_palette) + png_benign_error(png_ptr, "Wrote palette index exceeding num_palette"); + #endif +@@ -2391,5 +2400,43 @@ png_image_write_to_file(png_imagep image + return 0; + } + #endif /* SIMPLIFIED_WRITE_STDIO */ + #endif /* SIMPLIFIED_WRITE */ ++ ++#ifdef PNG_WRITE_APNG_SUPPORTED ++void PNGAPI ++png_write_frame_head(png_structp png_ptr, png_infop info_ptr, ++ png_bytepp row_pointers, png_uint_32 width, png_uint_32 height, ++ png_uint_32 x_offset, png_uint_32 y_offset, ++ png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, ++ png_byte blend_op) ++{ ++ png_debug(1, "in png_write_frame_head"); ++ ++ /* there is a chance this has been set after png_write_info was called, ++ * so it would be set but not written. is there a way to be sure? */ ++ if ((info_ptr->valid & PNG_INFO_acTL) == 0) ++ png_error(png_ptr, "png_write_frame_head(): acTL not set"); ++ ++ png_write_reset(png_ptr); ++ ++ png_write_reinit(png_ptr, info_ptr, width, height); ++ ++ if ((png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN) == 0 || ++ png_ptr->num_frames_written != 0) ++ png_write_fcTL(png_ptr, width, height, x_offset, y_offset, ++ delay_num, delay_den, dispose_op, blend_op); ++ ++ PNG_UNUSED(row_pointers) ++} ++ ++void PNGAPI ++png_write_frame_tail(png_structp png_ptr, png_infop info_ptr) ++{ ++ png_debug(1, "in png_write_frame_tail"); ++ ++ png_ptr->num_frames_written++; ++ ++ PNG_UNUSED(info_ptr) ++} ++#endif /* WRITE_APNG */ + #endif /* WRITE */ +diff --git a/pngwutil.c b/pngwutil.c +--- a/pngwutil.c ++++ b/pngwutil.c +@@ -820,8 +820,13 @@ png_write_IHDR(png_structrp png_ptr, png + + /* Write the chunk */ + png_write_complete_chunk(png_ptr, png_IHDR, buf, 13); + ++#ifdef PNG_WRITE_APNG_SUPPORTED ++ png_ptr->first_frame_width = width; ++ png_ptr->first_frame_height = height; ++#endif ++ + if ((png_ptr->do_filter) == PNG_NO_FILTERS) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || + png_ptr->bit_depth < 8) +@@ -1002,9 +1007,19 @@ png_compress_IDAT(png_structrp png_ptr, + optimize_cmf(data, png_image_size(png_ptr)); + #endif + + if (size > 0) ++#ifdef PNG_WRITE_APNG_SUPPORTED ++ { ++ if (png_ptr->num_frames_written == 0) ++#endif + png_write_complete_chunk(png_ptr, png_IDAT, data, size); ++#ifdef PNG_WRITE_APNG_SUPPORTED ++ else ++ png_write_fdAT(png_ptr, data, size); ++ } ++#endif /* WRITE_APNG */ ++ + png_ptr->mode |= PNG_HAVE_IDAT; + + png_ptr->zstream.next_out = data; + png_ptr->zstream.avail_out = size; +@@ -1049,9 +1064,19 @@ png_compress_IDAT(png_structrp png_ptr, + optimize_cmf(data, png_image_size(png_ptr)); + #endif + + if (size > 0) ++#ifdef PNG_WRITE_APNG_SUPPORTED ++ { ++ if (png_ptr->num_frames_written == 0) ++#endif + png_write_complete_chunk(png_ptr, png_IDAT, data, size); ++#ifdef PNG_WRITE_APNG_SUPPORTED ++ else ++ png_write_fdAT(png_ptr, data, size); ++ } ++#endif /* WRITE_APNG */ ++ + png_ptr->zstream.avail_out = 0; + png_ptr->zstream.next_out = NULL; + png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT; + +@@ -1884,8 +1909,84 @@ png_write_tIME(png_structrp png_ptr, png + png_write_complete_chunk(png_ptr, png_tIME, buf, 7); + } + #endif + ++#ifdef PNG_WRITE_APNG_SUPPORTED ++void /* PRIVATE */ ++png_write_acTL(png_structp png_ptr, ++ png_uint_32 num_frames, png_uint_32 num_plays) ++{ ++ png_byte buf[8]; ++ ++ png_debug(1, "in png_write_acTL"); ++ ++ png_ptr->num_frames_to_write = num_frames; ++ ++ if ((png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN) != 0) ++ num_frames--; ++ ++ png_save_uint_32(buf, num_frames); ++ png_save_uint_32(buf + 4, num_plays); ++ ++ png_write_complete_chunk(png_ptr, png_acTL, buf, (png_size_t)8); ++} ++ ++void /* PRIVATE */ ++png_write_fcTL(png_structp png_ptr, png_uint_32 width, png_uint_32 height, ++ png_uint_32 x_offset, png_uint_32 y_offset, ++ png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, ++ png_byte blend_op) ++{ ++ png_byte buf[26]; ++ ++ png_debug(1, "in png_write_fcTL"); ++ ++ if (png_ptr->num_frames_written == 0 && (x_offset != 0 || y_offset != 0)) ++ png_error(png_ptr, "x and/or y offset for the first frame aren't 0"); ++ if (png_ptr->num_frames_written == 0 && ++ (width != png_ptr->first_frame_width || ++ height != png_ptr->first_frame_height)) ++ png_error(png_ptr, "width and/or height in the first frame's fcTL " ++ "don't match the ones in IHDR"); ++ ++ /* more error checking */ ++ png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset, ++ delay_num, delay_den, dispose_op, blend_op); ++ ++ png_save_uint_32(buf, png_ptr->next_seq_num); ++ png_save_uint_32(buf + 4, width); ++ png_save_uint_32(buf + 8, height); ++ png_save_uint_32(buf + 12, x_offset); ++ png_save_uint_32(buf + 16, y_offset); ++ png_save_uint_16(buf + 20, delay_num); ++ png_save_uint_16(buf + 22, delay_den); ++ buf[24] = dispose_op; ++ buf[25] = blend_op; ++ ++ png_write_complete_chunk(png_ptr, png_fcTL, buf, (png_size_t)26); ++ ++ png_ptr->next_seq_num++; ++} ++ ++void /* PRIVATE */ ++png_write_fdAT(png_structp png_ptr, ++ png_const_bytep data, png_size_t length) ++{ ++ png_byte buf[4]; ++ ++ png_write_chunk_header(png_ptr, png_fdAT, (png_uint_32)(4 + length)); ++ ++ png_save_uint_32(buf, png_ptr->next_seq_num); ++ png_write_chunk_data(png_ptr, buf, 4); ++ ++ png_write_chunk_data(png_ptr, data, length); ++ ++ png_write_chunk_end(png_ptr); ++ ++ png_ptr->next_seq_num++; ++} ++#endif /* WRITE_APNG */ ++ + /* Initializes the row writing capability of libpng */ + void /* PRIVATE */ + png_write_start_row(png_structrp png_ptr) + { +@@ -2777,5 +2878,40 @@ png_write_filtered_row(png_structrp png_ + png_write_flush(png_ptr); + } + #endif /* WRITE_FLUSH */ + } ++ ++#ifdef PNG_WRITE_APNG_SUPPORTED ++void /* PRIVATE */ ++png_write_reset(png_structp png_ptr) ++{ ++ png_ptr->row_number = 0; ++ png_ptr->pass = 0; ++ png_ptr->mode &= ~PNG_HAVE_IDAT; ++} ++ ++void /* PRIVATE */ ++png_write_reinit(png_structp png_ptr, png_infop info_ptr, ++ png_uint_32 width, png_uint_32 height) ++{ ++ if (png_ptr->num_frames_written == 0 && ++ (width != png_ptr->first_frame_width || ++ height != png_ptr->first_frame_height)) ++ png_error(png_ptr, "width and/or height in the first frame's fcTL " ++ "don't match the ones in IHDR"); ++ if (width > png_ptr->first_frame_width || ++ height > png_ptr->first_frame_height) ++ png_error(png_ptr, "width and/or height for a frame greater than " ++ "the ones in IHDR"); ++ ++ png_set_IHDR(png_ptr, info_ptr, width, height, ++ info_ptr->bit_depth, info_ptr->color_type, ++ info_ptr->interlace_type, info_ptr->compression_type, ++ info_ptr->filter_type); ++ ++ png_ptr->width = width; ++ png_ptr->height = height; ++ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width); ++ png_ptr->usr_width = png_ptr->width; ++} ++#endif /* WRITE_APNG */ + #endif /* WRITE */ diff --git a/media/libpng/arm.patch b/media/libpng/arm.patch new file mode 100644 index 0000000000..6b93816fa7 --- /dev/null +++ b/media/libpng/arm.patch @@ -0,0 +1,32 @@ +diff --git a/arm/arm_init.c b/arm/arm_init.c +--- a/arm/arm_init.c ++++ b/arm/arm_init.c +@@ -34,9 +34,9 @@ + * implementation which reads /proc/cpufino. + */ + #ifndef PNG_ARM_NEON_FILE + # ifdef __linux__ +-# define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c" ++# define PNG_ARM_NEON_FILE "linux.c" + # endif + #endif + + #ifdef PNG_ARM_NEON_FILE +diff --git a/arm/filter_neon.S b/arm/filter_neon.S +--- a/arm/filter_neon.S ++++ b/arm/filter_neon.S +@@ -9,8 +9,14 @@ + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + ++/* These are required because Mozilla's moz.build system doesn't pass ++ * -DDefined macros to the assembler. ++ */ ++#define PNG_READ_SUPPORTED ++#define MOZ_PNG_HAVE_ARM_NEON ++ + /* This is required to get the symbol renames, which are #defines, and the + * definitions (or not) of PNG_ARM_NEON_OPT and PNG_ARM_NEON_IMPLEMENTATION. + */ + #define PNG_VERSION_INFO_ONLY diff --git a/media/libpng/arm/arm_init.c b/media/libpng/arm/arm_init.c new file mode 100644 index 0000000000..1ff9fd8178 --- /dev/null +++ b/media/libpng/arm/arm_init.c @@ -0,0 +1,136 @@ + +/* arm_init.c - NEON optimised filter functions + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 2014,2016 Glenn Randers-Pehrson + * Written by Mans Rullgard, 2011. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are + * called. + */ +#define _POSIX_SOURCE 1 + +#include "../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +#if PNG_ARM_NEON_OPT > 0 +#ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */ +/* WARNING: it is strongly recommended that you do not build libpng with + * run-time checks for CPU features if at all possible. In the case of the ARM + * NEON instructions there is no processor-specific way of detecting the + * presence of the required support, therefore run-time detection is extremely + * OS specific. + * + * You may set the macro PNG_ARM_NEON_FILE to the file name of file containing + * a fragment of C source code which defines the png_have_neon function. There + * are a number of implementations in contrib/arm-neon, but the only one that + * has partial support is contrib/arm-neon/linux.c - a generic Linux + * implementation which reads /proc/cpufino. + */ +#ifndef PNG_ARM_NEON_FILE +# ifdef __linux__ +# define PNG_ARM_NEON_FILE "linux.c" +# endif +#endif + +#ifdef PNG_ARM_NEON_FILE + +#include <signal.h> /* for sig_atomic_t */ +static int png_have_neon(png_structp png_ptr); +#include PNG_ARM_NEON_FILE + +#else /* PNG_ARM_NEON_FILE */ +# error "PNG_ARM_NEON_FILE undefined: no support for run-time ARM NEON checks" +#endif /* PNG_ARM_NEON_FILE */ +#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */ + +#ifndef PNG_ALIGNED_MEMORY_SUPPORTED +# error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED" +#endif + +void +png_init_filter_functions_neon(png_structp pp, unsigned int bpp) +{ + /* The switch statement is compiled in for ARM_NEON_API, the call to + * png_have_neon is compiled in for ARM_NEON_CHECK. If both are defined + * the check is only performed if the API has not set the NEON option on + * or off explicitly. In this case the check controls what happens. + * + * If the CHECK is not compiled in and the option is UNSET the behavior prior + * to 1.6.7 was to use the NEON code - this was a bug caused by having the + * wrong order of the 'ON' and 'default' cases. UNSET now defaults to OFF, + * as documented in png.h + */ + png_debug(1, "in png_init_filter_functions_neon"); +#ifdef PNG_ARM_NEON_API_SUPPORTED + switch ((pp->options >> PNG_ARM_NEON) & 3) + { + case PNG_OPTION_UNSET: + /* Allow the run-time check to execute if it has been enabled - + * thus both API and CHECK can be turned on. If it isn't supported + * this case will fall through to the 'default' below, which just + * returns. + */ +#endif /* PNG_ARM_NEON_API_SUPPORTED */ +#ifdef PNG_ARM_NEON_CHECK_SUPPORTED + { + static volatile sig_atomic_t no_neon = -1; /* not checked */ + + if (no_neon < 0) + no_neon = !png_have_neon(pp); + + if (no_neon) + return; + } +#ifdef PNG_ARM_NEON_API_SUPPORTED + break; +#endif +#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */ + +#ifdef PNG_ARM_NEON_API_SUPPORTED + default: /* OFF or INVALID */ + return; + + case PNG_OPTION_ON: + /* Option turned on */ + break; + } +#endif + + /* IMPORTANT: any new external functions used here must be declared using + * PNG_INTERNAL_FUNCTION in ../pngpriv.h. This is required so that the + * 'prefix' option to configure works: + * + * ./configure --with-libpng-prefix=foobar_ + * + * Verify you have got this right by running the above command, doing a build + * and examining pngprefix.h; it must contain a #define for every external + * function you add. (Notice that this happens automatically for the + * initialization function.) + */ + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon; + + if (bpp == 3) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth3_neon; + } + + else if (bpp == 4) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth4_neon; + } +} +#endif /* PNG_ARM_NEON_OPT > 0 */ +#endif /* READ */ diff --git a/media/libpng/arm/filter_neon.S b/media/libpng/arm/filter_neon.S new file mode 100644 index 0000000000..26d1363b49 --- /dev/null +++ b/media/libpng/arm/filter_neon.S @@ -0,0 +1,259 @@ + +/* filter_neon.S - NEON optimised filter functions + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 2014,2017 Glenn Randers-Pehrson + * Written by Mans Rullgard, 2011. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* These are required because Mozilla's moz.build system doesn't pass + * -DDefined macros to the assembler. + */ +#define PNG_READ_SUPPORTED +#define MOZ_PNG_HAVE_ARM_NEON + +/* This is required to get the symbol renames, which are #defines, and the + * definitions (or not) of PNG_ARM_NEON_OPT and PNG_ARM_NEON_IMPLEMENTATION. + */ +#define PNG_VERSION_INFO_ONLY +#include "../pngpriv.h" + +#if (defined(__linux__) || defined(__FreeBSD__)) && defined(__ELF__) +.section .note.GNU-stack,"",%progbits /* mark stack as non-executable */ +#endif + +#ifdef PNG_READ_SUPPORTED + +/* Assembler NEON support - only works for 32-bit ARM (i.e. it does not work for + * ARM64). The code in arm/filter_neon_intrinsics.c supports ARM64, however it + * only works if -mfpu=neon is specified on the GCC command line. See pngpriv.h + * for the logic which sets PNG_USE_ARM_NEON_ASM: + */ +#if PNG_ARM_NEON_IMPLEMENTATION == 2 /* hand-coded assembler */ + +#if PNG_ARM_NEON_OPT > 0 + +#ifdef __ELF__ +# define ELF +#else +# define ELF @ +#endif + + .arch armv7-a + .fpu neon + +.macro func name, export=0 + .macro endfunc +ELF .size \name, . - \name + .endfunc + .purgem endfunc + .endm + .text + + /* Explicitly specifying alignment here because some versions of + * GAS don't align code correctly. This is harmless in correctly + * written versions of GAS. + */ + .align 2 + + .if \export + .global \name + .endif +ELF .type \name, STT_FUNC + .func \name +\name: +.endm + +func png_read_filter_row_sub4_neon, export=1 + ldr r3, [r0, #4] @ rowbytes + vmov.i8 d3, #0 +1: + vld4.32 {d4[],d5[],d6[],d7[]}, [r1,:128] + vadd.u8 d0, d3, d4 + vadd.u8 d1, d0, d5 + vadd.u8 d2, d1, d6 + vadd.u8 d3, d2, d7 + vst4.32 {d0[0],d1[0],d2[0],d3[0]},[r1,:128]! + subs r3, r3, #16 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_sub3_neon, export=1 + ldr r3, [r0, #4] @ rowbytes + vmov.i8 d3, #0 + mov r0, r1 + mov r2, #3 + mov r12, #12 + vld1.8 {q11}, [r0], r12 +1: + vext.8 d5, d22, d23, #3 + vadd.u8 d0, d3, d22 + vext.8 d6, d22, d23, #6 + vadd.u8 d1, d0, d5 + vext.8 d7, d23, d23, #1 + vld1.8 {q11}, [r0], r12 + vst1.32 {d0[0]}, [r1,:32], r2 + vadd.u8 d2, d1, d6 + vst1.32 {d1[0]}, [r1], r2 + vadd.u8 d3, d2, d7 + vst1.32 {d2[0]}, [r1], r2 + vst1.32 {d3[0]}, [r1], r2 + subs r3, r3, #12 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_up_neon, export=1 + ldr r3, [r0, #4] @ rowbytes +1: + vld1.8 {q0}, [r1,:128] + vld1.8 {q1}, [r2,:128]! + vadd.u8 q0, q0, q1 + vst1.8 {q0}, [r1,:128]! + subs r3, r3, #16 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_avg4_neon, export=1 + ldr r12, [r0, #4] @ rowbytes + vmov.i8 d3, #0 +1: + vld4.32 {d4[],d5[],d6[],d7[]}, [r1,:128] + vld4.32 {d16[],d17[],d18[],d19[]},[r2,:128]! + vhadd.u8 d0, d3, d16 + vadd.u8 d0, d0, d4 + vhadd.u8 d1, d0, d17 + vadd.u8 d1, d1, d5 + vhadd.u8 d2, d1, d18 + vadd.u8 d2, d2, d6 + vhadd.u8 d3, d2, d19 + vadd.u8 d3, d3, d7 + vst4.32 {d0[0],d1[0],d2[0],d3[0]},[r1,:128]! + subs r12, r12, #16 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_avg3_neon, export=1 + push {r4,lr} + ldr r12, [r0, #4] @ rowbytes + vmov.i8 d3, #0 + mov r0, r1 + mov r4, #3 + mov lr, #12 + vld1.8 {q11}, [r0], lr +1: + vld1.8 {q10}, [r2], lr + vext.8 d5, d22, d23, #3 + vhadd.u8 d0, d3, d20 + vext.8 d17, d20, d21, #3 + vadd.u8 d0, d0, d22 + vext.8 d6, d22, d23, #6 + vhadd.u8 d1, d0, d17 + vext.8 d18, d20, d21, #6 + vadd.u8 d1, d1, d5 + vext.8 d7, d23, d23, #1 + vld1.8 {q11}, [r0], lr + vst1.32 {d0[0]}, [r1,:32], r4 + vhadd.u8 d2, d1, d18 + vst1.32 {d1[0]}, [r1], r4 + vext.8 d19, d21, d21, #1 + vadd.u8 d2, d2, d6 + vhadd.u8 d3, d2, d19 + vst1.32 {d2[0]}, [r1], r4 + vadd.u8 d3, d3, d7 + vst1.32 {d3[0]}, [r1], r4 + subs r12, r12, #12 + bgt 1b + + pop {r4,pc} +endfunc + +.macro paeth rx, ra, rb, rc + vaddl.u8 q12, \ra, \rb @ a + b + vaddl.u8 q15, \rc, \rc @ 2*c + vabdl.u8 q13, \rb, \rc @ pa + vabdl.u8 q14, \ra, \rc @ pb + vabd.u16 q15, q12, q15 @ pc + vcle.u16 q12, q13, q14 @ pa <= pb + vcle.u16 q13, q13, q15 @ pa <= pc + vcle.u16 q14, q14, q15 @ pb <= pc + vand q12, q12, q13 @ pa <= pb && pa <= pc + vmovn.u16 d28, q14 + vmovn.u16 \rx, q12 + vbsl d28, \rb, \rc + vbsl \rx, \ra, d28 +.endm + +func png_read_filter_row_paeth4_neon, export=1 + ldr r12, [r0, #4] @ rowbytes + vmov.i8 d3, #0 + vmov.i8 d20, #0 +1: + vld4.32 {d4[],d5[],d6[],d7[]}, [r1,:128] + vld4.32 {d16[],d17[],d18[],d19[]},[r2,:128]! + paeth d0, d3, d16, d20 + vadd.u8 d0, d0, d4 + paeth d1, d0, d17, d16 + vadd.u8 d1, d1, d5 + paeth d2, d1, d18, d17 + vadd.u8 d2, d2, d6 + paeth d3, d2, d19, d18 + vmov d20, d19 + vadd.u8 d3, d3, d7 + vst4.32 {d0[0],d1[0],d2[0],d3[0]},[r1,:128]! + subs r12, r12, #16 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_paeth3_neon, export=1 + push {r4,lr} + ldr r12, [r0, #4] @ rowbytes + vmov.i8 d3, #0 + vmov.i8 d4, #0 + mov r0, r1 + mov r4, #3 + mov lr, #12 + vld1.8 {q11}, [r0], lr +1: + vld1.8 {q10}, [r2], lr + paeth d0, d3, d20, d4 + vext.8 d5, d22, d23, #3 + vadd.u8 d0, d0, d22 + vext.8 d17, d20, d21, #3 + paeth d1, d0, d17, d20 + vst1.32 {d0[0]}, [r1,:32], r4 + vext.8 d6, d22, d23, #6 + vadd.u8 d1, d1, d5 + vext.8 d18, d20, d21, #6 + paeth d2, d1, d18, d17 + vext.8 d7, d23, d23, #1 + vld1.8 {q11}, [r0], lr + vst1.32 {d1[0]}, [r1], r4 + vadd.u8 d2, d2, d6 + vext.8 d19, d21, d21, #1 + paeth d3, d2, d19, d18 + vst1.32 {d2[0]}, [r1], r4 + vmov d4, d19 + vadd.u8 d3, d3, d7 + vst1.32 {d3[0]}, [r1], r4 + subs r12, r12, #12 + bgt 1b + + pop {r4,pc} +endfunc +#endif /* PNG_ARM_NEON_OPT > 0 */ +#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 (assembler) */ +#endif /* READ */ diff --git a/media/libpng/arm/filter_neon_intrinsics.c b/media/libpng/arm/filter_neon_intrinsics.c new file mode 100644 index 0000000000..0647bfa425 --- /dev/null +++ b/media/libpng/arm/filter_neon_intrinsics.c @@ -0,0 +1,402 @@ + +/* filter_neon_intrinsics.c - NEON optimised filter functions + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 2014,2016 Glenn Randers-Pehrson + * Written by James Yu <james.yu at linaro.org>, October 2013. + * Based on filter_neon.S, written by Mans Rullgard, 2011. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +/* This code requires -mfpu=neon on the command line: */ +#if PNG_ARM_NEON_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */ + +#if defined(_MSC_VER) && defined(_M_ARM64) && !defined(__clang__) +# include <arm64_neon.h> +#else +# include <arm_neon.h> +#endif + +/* libpng row pointers are not necessarily aligned to any particular boundary, + * however this code will only work with appropriate alignment. arm/arm_init.c + * checks for this (and will not compile unless it is done). This code uses + * variants of png_aligncast to avoid compiler warnings. + */ +#define png_ptr(type,pointer) png_aligncast(type *,pointer) +#define png_ptrc(type,pointer) png_aligncastconst(const type *,pointer) + +/* The following relies on a variable 'temp_pointer' being declared with type + * 'type'. This is written this way just to hide the GCC strict aliasing + * warning; note that the code is safe because there never is an alias between + * the input and output pointers. + * + * When compiling with MSVC ARM64, the png_ldr macro can't be passed directly + * to vst4_lane_u32, because of an internal compiler error inside MSVC. + * To avoid this compiler bug, we use a temporary variable (vdest_val) to store + * the result of png_ldr. + */ +#define png_ldr(type,pointer)\ + (temp_pointer = png_ptr(type,pointer), *temp_pointer) + +#if PNG_ARM_NEON_OPT > 0 + +void +png_read_filter_row_up_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_bytep rp_stop = row + row_info->rowbytes; + png_const_bytep pp = prev_row; + + png_debug(1, "in png_read_filter_row_up_neon"); + + for (; rp < rp_stop; rp += 16, pp += 16) + { + uint8x16_t qrp, qpp; + + qrp = vld1q_u8(rp); + qpp = vld1q_u8(pp); + qrp = vaddq_u8(qrp, qpp); + vst1q_u8(rp, qrp); + } +} + +void +png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_bytep rp_stop = row + row_info->rowbytes; + + uint8x16_t vtmp = vld1q_u8(rp); + uint8x8x2_t *vrpt = png_ptr(uint8x8x2_t, &vtmp); + uint8x8x2_t vrp = *vrpt; + + uint8x8x4_t vdest; + vdest.val[3] = vdup_n_u8(0); + + png_debug(1, "in png_read_filter_row_sub3_neon"); + + for (; rp < rp_stop;) + { + uint8x8_t vtmp1, vtmp2; + uint32x2_t *temp_pointer; + + vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3); + vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]); + vtmp2 = vext_u8(vrp.val[0], vrp.val[1], 6); + vdest.val[1] = vadd_u8(vdest.val[0], vtmp1); + + vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1); + vdest.val[2] = vadd_u8(vdest.val[1], vtmp2); + vdest.val[3] = vadd_u8(vdest.val[2], vtmp1); + + vtmp = vld1q_u8(rp + 12); + vrpt = png_ptr(uint8x8x2_t, &vtmp); + vrp = *vrpt; + + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0); + rp += 3; + } + + PNG_UNUSED(prev_row) +} + +void +png_read_filter_row_sub4_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_bytep rp_stop = row + row_info->rowbytes; + + uint8x8x4_t vdest; + vdest.val[3] = vdup_n_u8(0); + + png_debug(1, "in png_read_filter_row_sub4_neon"); + + for (; rp < rp_stop; rp += 16) + { + uint32x2x4_t vtmp = vld4_u32(png_ptr(uint32_t,rp)); + uint8x8x4_t *vrpt = png_ptr(uint8x8x4_t,&vtmp); + uint8x8x4_t vrp = *vrpt; + uint32x2x4_t *temp_pointer; + uint32x2x4_t vdest_val; + + vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]); + vdest.val[1] = vadd_u8(vdest.val[0], vrp.val[1]); + vdest.val[2] = vadd_u8(vdest.val[1], vrp.val[2]); + vdest.val[3] = vadd_u8(vdest.val[2], vrp.val[3]); + + vdest_val = png_ldr(uint32x2x4_t, &vdest); + vst4_lane_u32(png_ptr(uint32_t,rp), vdest_val, 0); + } + + PNG_UNUSED(prev_row) +} + +void +png_read_filter_row_avg3_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_const_bytep pp = prev_row; + png_bytep rp_stop = row + row_info->rowbytes; + + uint8x16_t vtmp; + uint8x8x2_t *vrpt; + uint8x8x2_t vrp; + uint8x8x4_t vdest; + vdest.val[3] = vdup_n_u8(0); + + vtmp = vld1q_u8(rp); + vrpt = png_ptr(uint8x8x2_t,&vtmp); + vrp = *vrpt; + + png_debug(1, "in png_read_filter_row_avg3_neon"); + + for (; rp < rp_stop; pp += 12) + { + uint8x8_t vtmp1, vtmp2, vtmp3; + + uint8x8x2_t *vppt; + uint8x8x2_t vpp; + + uint32x2_t *temp_pointer; + + vtmp = vld1q_u8(pp); + vppt = png_ptr(uint8x8x2_t,&vtmp); + vpp = *vppt; + + vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3); + vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]); + vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]); + + vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3); + vtmp3 = vext_u8(vrp.val[0], vrp.val[1], 6); + vdest.val[1] = vhadd_u8(vdest.val[0], vtmp2); + vdest.val[1] = vadd_u8(vdest.val[1], vtmp1); + + vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 6); + vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1); + + vtmp = vld1q_u8(rp + 12); + vrpt = png_ptr(uint8x8x2_t,&vtmp); + vrp = *vrpt; + + vdest.val[2] = vhadd_u8(vdest.val[1], vtmp2); + vdest.val[2] = vadd_u8(vdest.val[2], vtmp3); + + vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1); + + vdest.val[3] = vhadd_u8(vdest.val[2], vtmp2); + vdest.val[3] = vadd_u8(vdest.val[3], vtmp1); + + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0); + rp += 3; + } +} + +void +png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_bytep rp_stop = row + row_info->rowbytes; + png_const_bytep pp = prev_row; + + uint8x8x4_t vdest; + vdest.val[3] = vdup_n_u8(0); + + png_debug(1, "in png_read_filter_row_avg4_neon"); + + for (; rp < rp_stop; rp += 16, pp += 16) + { + uint32x2x4_t vtmp; + uint8x8x4_t *vrpt, *vppt; + uint8x8x4_t vrp, vpp; + uint32x2x4_t *temp_pointer; + uint32x2x4_t vdest_val; + + vtmp = vld4_u32(png_ptr(uint32_t,rp)); + vrpt = png_ptr(uint8x8x4_t,&vtmp); + vrp = *vrpt; + vtmp = vld4_u32(png_ptrc(uint32_t,pp)); + vppt = png_ptr(uint8x8x4_t,&vtmp); + vpp = *vppt; + + vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]); + vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]); + vdest.val[1] = vhadd_u8(vdest.val[0], vpp.val[1]); + vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]); + vdest.val[2] = vhadd_u8(vdest.val[1], vpp.val[2]); + vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]); + vdest.val[3] = vhadd_u8(vdest.val[2], vpp.val[3]); + vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]); + + vdest_val = png_ldr(uint32x2x4_t, &vdest); + vst4_lane_u32(png_ptr(uint32_t,rp), vdest_val, 0); + } +} + +static uint8x8_t +paeth(uint8x8_t a, uint8x8_t b, uint8x8_t c) +{ + uint8x8_t d, e; + uint16x8_t p1, pa, pb, pc; + + p1 = vaddl_u8(a, b); /* a + b */ + pc = vaddl_u8(c, c); /* c * 2 */ + pa = vabdl_u8(b, c); /* pa */ + pb = vabdl_u8(a, c); /* pb */ + pc = vabdq_u16(p1, pc); /* pc */ + + p1 = vcleq_u16(pa, pb); /* pa <= pb */ + pa = vcleq_u16(pa, pc); /* pa <= pc */ + pb = vcleq_u16(pb, pc); /* pb <= pc */ + + p1 = vandq_u16(p1, pa); /* pa <= pb && pa <= pc */ + + d = vmovn_u16(pb); + e = vmovn_u16(p1); + + d = vbsl_u8(d, b, c); + e = vbsl_u8(e, a, d); + + return e; +} + +void +png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_const_bytep pp = prev_row; + png_bytep rp_stop = row + row_info->rowbytes; + + uint8x16_t vtmp; + uint8x8x2_t *vrpt; + uint8x8x2_t vrp; + uint8x8_t vlast = vdup_n_u8(0); + uint8x8x4_t vdest; + vdest.val[3] = vdup_n_u8(0); + + vtmp = vld1q_u8(rp); + vrpt = png_ptr(uint8x8x2_t,&vtmp); + vrp = *vrpt; + + png_debug(1, "in png_read_filter_row_paeth3_neon"); + + for (; rp < rp_stop; pp += 12) + { + uint8x8x2_t *vppt; + uint8x8x2_t vpp; + uint8x8_t vtmp1, vtmp2, vtmp3; + uint32x2_t *temp_pointer; + + vtmp = vld1q_u8(pp); + vppt = png_ptr(uint8x8x2_t,&vtmp); + vpp = *vppt; + + vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast); + vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]); + + vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3); + vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3); + vdest.val[1] = paeth(vdest.val[0], vtmp2, vpp.val[0]); + vdest.val[1] = vadd_u8(vdest.val[1], vtmp1); + + vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 6); + vtmp3 = vext_u8(vpp.val[0], vpp.val[1], 6); + vdest.val[2] = paeth(vdest.val[1], vtmp3, vtmp2); + vdest.val[2] = vadd_u8(vdest.val[2], vtmp1); + + vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1); + vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1); + + vtmp = vld1q_u8(rp + 12); + vrpt = png_ptr(uint8x8x2_t,&vtmp); + vrp = *vrpt; + + vdest.val[3] = paeth(vdest.val[2], vtmp2, vtmp3); + vdest.val[3] = vadd_u8(vdest.val[3], vtmp1); + + vlast = vtmp2; + + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0); + rp += 3; + } +} + +void +png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_bytep rp_stop = row + row_info->rowbytes; + png_const_bytep pp = prev_row; + + uint8x8_t vlast = vdup_n_u8(0); + uint8x8x4_t vdest; + vdest.val[3] = vdup_n_u8(0); + + png_debug(1, "in png_read_filter_row_paeth4_neon"); + + for (; rp < rp_stop; rp += 16, pp += 16) + { + uint32x2x4_t vtmp; + uint8x8x4_t *vrpt, *vppt; + uint8x8x4_t vrp, vpp; + uint32x2x4_t *temp_pointer; + uint32x2x4_t vdest_val; + + vtmp = vld4_u32(png_ptr(uint32_t,rp)); + vrpt = png_ptr(uint8x8x4_t,&vtmp); + vrp = *vrpt; + vtmp = vld4_u32(png_ptrc(uint32_t,pp)); + vppt = png_ptr(uint8x8x4_t,&vtmp); + vpp = *vppt; + + vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast); + vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]); + vdest.val[1] = paeth(vdest.val[0], vpp.val[1], vpp.val[0]); + vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]); + vdest.val[2] = paeth(vdest.val[1], vpp.val[2], vpp.val[1]); + vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]); + vdest.val[3] = paeth(vdest.val[2], vpp.val[3], vpp.val[2]); + vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]); + + vlast = vpp.val[3]; + + vdest_val = png_ldr(uint32x2x4_t, &vdest); + vst4_lane_u32(png_ptr(uint32_t,rp), vdest_val, 0); + } +} + +#endif /* PNG_ARM_NEON_OPT > 0 */ +#endif /* PNG_ARM_NEON_IMPLEMENTATION == 1 (intrinsics) */ +#endif /* READ */ diff --git a/media/libpng/arm/linux.c b/media/libpng/arm/linux.c new file mode 100644 index 0000000000..a9bc360dd5 --- /dev/null +++ b/media/libpng/arm/linux.c @@ -0,0 +1,161 @@ +/* contrib/arm-neon/linux.c + * + * Last changed in libpng 1.6.31 [July 27, 2017] + * Copyright (c) 2014, 2017 Glenn Randers-Pehrson + * Written by John Bowler, 2014, 2017. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * SEE contrib/arm-neon/README before reporting bugs + * + * STATUS: SUPPORTED + * BUG REPORTS: png-mng-implement@sourceforge.net + * + * png_have_neon implemented for Linux by reading the widely available + * pseudo-file /proc/cpuinfo. + * + * This code is strict ANSI-C and is probably moderately portable; it does + * however use <stdio.h> and it assumes that /proc/cpuinfo is never localized. + */ +#include <stdio.h> + +static int +png_have_neon(png_structp png_ptr) +{ + FILE *f = fopen("/proc/cpuinfo", "rb"); + + if (f != NULL) + { + /* This is a simple state machine which reads the input byte-by-byte until + * it gets a match on the 'neon' feature or reaches the end of the stream. + */ + static const char ch_feature[] = { 70, 69, 65, 84, 85, 82, 69, 83 }; + static const char ch_neon[] = { 78, 69, 79, 78 }; + + enum + { + StartLine, Feature, Colon, StartTag, Neon, HaveNeon, SkipTag, SkipLine + } state; + int counter; + + for (state=StartLine, counter=0;;) + { + int ch = fgetc(f); + + if (ch == EOF) + { + /* EOF means error or end-of-file, return false; neon at EOF is + * assumed to be a mistake. + */ + fclose(f); + return 0; + } + + switch (state) + { + case StartLine: + /* Match spaces at the start of line */ + if (ch <= 32) /* skip control characters and space */ + break; + + counter=0; + state = Feature; + /* FALLTHROUGH */ + + case Feature: + /* Match 'FEATURE', ASCII case insensitive. */ + if ((ch & ~0x20) == ch_feature[counter]) + { + if (++counter == (sizeof ch_feature)) + state = Colon; + break; + } + + /* did not match 'feature' */ + state = SkipLine; + /* FALLTHROUGH */ + + case SkipLine: + skipLine: + /* Skip everything until we see linefeed or carriage return */ + if (ch != 10 && ch != 13) + break; + + state = StartLine; + break; + + case Colon: + /* Match any number of space or tab followed by ':' */ + if (ch == 32 || ch == 9) + break; + + if (ch == 58) /* i.e. ':' */ + { + state = StartTag; + break; + } + + /* Either a bad line format or a 'feature' prefix followed by + * other characters. + */ + state = SkipLine; + goto skipLine; + + case StartTag: + /* Skip space characters before a tag */ + if (ch == 32 || ch == 9) + break; + + state = Neon; + counter = 0; + /* FALLTHROUGH */ + + case Neon: + /* Look for 'neon' tag */ + if ((ch & ~0x20) == ch_neon[counter]) + { + if (++counter == (sizeof ch_neon)) + state = HaveNeon; + break; + } + + state = SkipTag; + /* FALLTHROUGH */ + + case SkipTag: + /* Skip non-space characters */ + if (ch == 10 || ch == 13) + state = StartLine; + + else if (ch == 32 || ch == 9) + state = StartTag; + break; + + case HaveNeon: + /* Have seen a 'neon' prefix, but there must be a space or new + * line character to terminate it. + */ + if (ch == 10 || ch == 13 || ch == 32 || ch == 9) + { + fclose(f); + return 1; + } + + state = SkipTag; + break; + + default: + png_error(png_ptr, "png_have_neon: internal error (bug)"); + } + } + } + +#ifdef PNG_WARNINGS_SUPPORTED + else + png_warning(png_ptr, "/proc/cpuinfo open failed"); +#endif + + return 0; +} diff --git a/media/libpng/arm/palette_neon_intrinsics.c b/media/libpng/arm/palette_neon_intrinsics.c new file mode 100644 index 0000000000..8217d65ac6 --- /dev/null +++ b/media/libpng/arm/palette_neon_intrinsics.c @@ -0,0 +1,149 @@ + +/* palette_neon_intrinsics.c - NEON optimised palette expansion functions + * + * Copyright (c) 2018-2019 Cosmin Truta + * Copyright (c) 2017-2018 Arm Holdings. All rights reserved. + * Written by Richard Townsend <Richard.Townsend@arm.com>, February 2017. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "../pngpriv.h" + +#if PNG_ARM_NEON_IMPLEMENTATION == 1 + +#if defined(_MSC_VER) && defined(_M_ARM64) && !defined(__clang__) +# include <arm64_neon.h> +#else +# include <arm_neon.h> +#endif + +/* Build an RGBA8 palette from the separate RGB and alpha palettes. */ +void +png_riffle_palette_neon(png_structrp png_ptr) +{ + png_const_colorp palette = png_ptr->palette; + png_bytep riffled_palette = png_ptr->riffled_palette; + png_const_bytep trans_alpha = png_ptr->trans_alpha; + int num_trans = png_ptr->num_trans; + int i; + + png_debug(1, "in png_riffle_palette_neon"); + + /* Initially black, opaque. */ + uint8x16x4_t w = {{ + vdupq_n_u8(0x00), + vdupq_n_u8(0x00), + vdupq_n_u8(0x00), + vdupq_n_u8(0xff), + }}; + + /* First, riffle the RGB colours into an RGBA8 palette. + * The alpha component is set to opaque for now. + */ + for (i = 0; i < 256; i += 16) + { + uint8x16x3_t v = vld3q_u8((png_const_bytep)(palette + i)); + w.val[0] = v.val[0]; + w.val[1] = v.val[1]; + w.val[2] = v.val[2]; + vst4q_u8(riffled_palette + (i << 2), w); + } + + /* Fix up the missing transparency values. */ + for (i = 0; i < num_trans; i++) + riffled_palette[(i << 2) + 3] = trans_alpha[i]; +} + +/* Expands a palettized row into RGBA8. */ +int +png_do_expand_palette_rgba8_neon(png_structrp png_ptr, png_row_infop row_info, + png_const_bytep row, png_bytepp ssp, png_bytepp ddp) +{ + png_uint_32 row_width = row_info->width; + const png_uint_32 *riffled_palette = + (const png_uint_32 *)png_ptr->riffled_palette; + const png_int_32 pixels_per_chunk = 4; + int i; + + png_debug(1, "in png_do_expand_palette_rgba8_neon"); + + if (row_width < pixels_per_chunk) + return 0; + + /* This function originally gets the last byte of the output row. + * The NEON part writes forward from a given position, so we have + * to seek this back by 4 pixels x 4 bytes. + */ + *ddp = *ddp - ((pixels_per_chunk * sizeof(png_uint_32)) - 1); + + for (i = 0; i < row_width; i += pixels_per_chunk) + { + uint32x4_t cur; + png_bytep sp = *ssp - i, dp = *ddp - (i << 2); + cur = vld1q_dup_u32 (riffled_palette + *(sp - 3)); + cur = vld1q_lane_u32(riffled_palette + *(sp - 2), cur, 1); + cur = vld1q_lane_u32(riffled_palette + *(sp - 1), cur, 2); + cur = vld1q_lane_u32(riffled_palette + *(sp - 0), cur, 3); + vst1q_u32((void *)dp, cur); + } + if (i != row_width) + { + /* Remove the amount that wasn't processed. */ + i -= pixels_per_chunk; + } + + /* Decrement output pointers. */ + *ssp = *ssp - i; + *ddp = *ddp - (i << 2); + return i; +} + +/* Expands a palettized row into RGB8. */ +int +png_do_expand_palette_rgb8_neon(png_structrp png_ptr, png_row_infop row_info, + png_const_bytep row, png_bytepp ssp, png_bytepp ddp) +{ + png_uint_32 row_width = row_info->width; + png_const_bytep palette = (png_const_bytep)png_ptr->palette; + const png_uint_32 pixels_per_chunk = 8; + int i; + + png_debug(1, "in png_do_expand_palette_rgb8_neon"); + + if (row_width <= pixels_per_chunk) + return 0; + + /* Seeking this back by 8 pixels x 3 bytes. */ + *ddp = *ddp - ((pixels_per_chunk * sizeof(png_color)) - 1); + + for (i = 0; i < row_width; i += pixels_per_chunk) + { + uint8x8x3_t cur; + png_bytep sp = *ssp - i, dp = *ddp - ((i << 1) + i); + cur = vld3_dup_u8(palette + sizeof(png_color) * (*(sp - 7))); + cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 6)), cur, 1); + cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 5)), cur, 2); + cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 4)), cur, 3); + cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 3)), cur, 4); + cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 2)), cur, 5); + cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 1)), cur, 6); + cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 0)), cur, 7); + vst3_u8((void *)dp, cur); + } + + if (i != row_width) + { + /* Remove the amount that wasn't processed. */ + i -= pixels_per_chunk; + } + + /* Decrement output pointers. */ + *ssp = *ssp - i; + *ddp = *ddp - ((i << 1) + i); + return i; +} + +#endif /* PNG_ARM_NEON_IMPLEMENTATION */ diff --git a/media/libpng/crashtests/374810-1.html b/media/libpng/crashtests/374810-1.html new file mode 100644 index 0000000000..40fe1cd746 --- /dev/null +++ b/media/libpng/crashtests/374810-1.html @@ -0,0 +1 @@ +<img 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diff --git a/media/libpng/crashtests/945912-1.html b/media/libpng/crashtests/945912-1.html new file mode 100644 index 0000000000..ada73a82ba --- /dev/null +++ b/media/libpng/crashtests/945912-1.html @@ -0,0 +1,8 @@ +<html><head><title>crash test for bug #945912</title></head> +<body> +<img src="data:image/png;base64, +iVBORw0KGgoAAAANSUhEUgAAAEAAAAAgAQMAAACYU+zHAAAAAFBMVEVLqIlVAAAADUlEQVQY02Ng +GAX4AAABIAABYJ+juAAAAABJRU5ErkJggg== +"> +</body> +</html> diff --git a/media/libpng/crashtests/974825-1.html b/media/libpng/crashtests/974825-1.html new file mode 100644 index 0000000000..ef19df54da --- /dev/null +++ b/media/libpng/crashtests/974825-1.html @@ -0,0 +1,7 @@ +<html><head><title>crash test for bug #974825</title></head> +<body> +<img alt="Crash Test bug#974825" title="Crash Test bug#974825" +src="data:image/png;base64, +iVBORw0KGgoAAAANSUhEUgAAAEAAAAAgCAYAAACinX6EAAAAAElEQVRKVU5LdGhlIGp1TmtKVU5LCg=="> +</body> +</html> diff --git a/media/libpng/crashtests/crashtests.list b/media/libpng/crashtests/crashtests.list new file mode 100644 index 0000000000..3a9a2cba3b --- /dev/null +++ b/media/libpng/crashtests/crashtests.list @@ -0,0 +1,3 @@ +load 374810-1.html +load 945912-1.html +load 974825-1.html diff --git a/media/libpng/intel/filter_sse2_intrinsics.c b/media/libpng/intel/filter_sse2_intrinsics.c new file mode 100644 index 0000000000..f52aaa800a --- /dev/null +++ b/media/libpng/intel/filter_sse2_intrinsics.c @@ -0,0 +1,391 @@ + +/* filter_sse2_intrinsics.c - SSE2 optimized filter functions + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 2016-2017 Glenn Randers-Pehrson + * Written by Mike Klein and Matt Sarett + * Derived from arm/filter_neon_intrinsics.c + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +#if PNG_INTEL_SSE_IMPLEMENTATION > 0 + +#include <immintrin.h> + +/* Functions in this file look at most 3 pixels (a,b,c) to predict the 4th (d). + * They're positioned like this: + * prev: c b + * row: a d + * The Sub filter predicts d=a, Avg d=(a+b)/2, and Paeth predicts d to be + * whichever of a, b, or c is closest to p=a+b-c. + */ + +static __m128i load4(const void* p) { + int tmp; + memcpy(&tmp, p, sizeof(tmp)); + return _mm_cvtsi32_si128(tmp); +} + +static void store4(void* p, __m128i v) { + int tmp = _mm_cvtsi128_si32(v); + memcpy(p, &tmp, sizeof(int)); +} + +static __m128i load3(const void* p) { + png_uint_32 tmp = 0; + memcpy(&tmp, p, 3); + return _mm_cvtsi32_si128(tmp); +} + +static void store3(void* p, __m128i v) { + int tmp = _mm_cvtsi128_si32(v); + memcpy(p, &tmp, 3); +} + +void png_read_filter_row_sub3_sse2(png_row_infop row_info, png_bytep row, + png_const_bytep prev) +{ + /* The Sub filter predicts each pixel as the previous pixel, a. + * There is no pixel to the left of the first pixel. It's encoded directly. + * That works with our main loop if we just say that left pixel was zero. + */ + size_t rb; + + __m128i a, d = _mm_setzero_si128(); + + png_debug(1, "in png_read_filter_row_sub3_sse2"); + + rb = row_info->rowbytes; + while (rb >= 4) { + a = d; d = load4(row); + d = _mm_add_epi8(d, a); + store3(row, d); + + row += 3; + rb -= 3; + } + if (rb > 0) { + a = d; d = load3(row); + d = _mm_add_epi8(d, a); + store3(row, d); + + row += 3; + rb -= 3; + } + PNG_UNUSED(prev) +} + +void png_read_filter_row_sub4_sse2(png_row_infop row_info, png_bytep row, + png_const_bytep prev) +{ + /* The Sub filter predicts each pixel as the previous pixel, a. + * There is no pixel to the left of the first pixel. It's encoded directly. + * That works with our main loop if we just say that left pixel was zero. + */ + size_t rb; + + __m128i a, d = _mm_setzero_si128(); + + png_debug(1, "in png_read_filter_row_sub4_sse2"); + + rb = row_info->rowbytes+4; + while (rb > 4) { + a = d; d = load4(row); + d = _mm_add_epi8(d, a); + store4(row, d); + + row += 4; + rb -= 4; + } + PNG_UNUSED(prev) +} + +void png_read_filter_row_avg3_sse2(png_row_infop row_info, png_bytep row, + png_const_bytep prev) +{ + /* The Avg filter predicts each pixel as the (truncated) average of a and b. + * There's no pixel to the left of the first pixel. Luckily, it's + * predicted to be half of the pixel above it. So again, this works + * perfectly with our loop if we make sure a starts at zero. + */ + + size_t rb; + + const __m128i zero = _mm_setzero_si128(); + + __m128i b; + __m128i a, d = zero; + + png_debug(1, "in png_read_filter_row_avg3_sse2"); + rb = row_info->rowbytes; + while (rb >= 4) { + __m128i avg; + b = load4(prev); + a = d; d = load4(row ); + + /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */ + avg = _mm_avg_epu8(a,b); + /* ...but we can fix it up by subtracting off 1 if it rounded up. */ + avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b), + _mm_set1_epi8(1))); + d = _mm_add_epi8(d, avg); + store3(row, d); + + prev += 3; + row += 3; + rb -= 3; + } + if (rb > 0) { + __m128i avg; + b = load3(prev); + a = d; d = load3(row ); + + /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */ + avg = _mm_avg_epu8(a,b); + /* ...but we can fix it up by subtracting off 1 if it rounded up. */ + avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b), + _mm_set1_epi8(1))); + + d = _mm_add_epi8(d, avg); + store3(row, d); + + prev += 3; + row += 3; + rb -= 3; + } +} + +void png_read_filter_row_avg4_sse2(png_row_infop row_info, png_bytep row, + png_const_bytep prev) +{ + /* The Avg filter predicts each pixel as the (truncated) average of a and b. + * There's no pixel to the left of the first pixel. Luckily, it's + * predicted to be half of the pixel above it. So again, this works + * perfectly with our loop if we make sure a starts at zero. + */ + size_t rb; + const __m128i zero = _mm_setzero_si128(); + __m128i b; + __m128i a, d = zero; + + png_debug(1, "in png_read_filter_row_avg4_sse2"); + + rb = row_info->rowbytes+4; + while (rb > 4) { + __m128i avg; + b = load4(prev); + a = d; d = load4(row ); + + /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */ + avg = _mm_avg_epu8(a,b); + /* ...but we can fix it up by subtracting off 1 if it rounded up. */ + avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b), + _mm_set1_epi8(1))); + + d = _mm_add_epi8(d, avg); + store4(row, d); + + prev += 4; + row += 4; + rb -= 4; + } +} + +/* Returns |x| for 16-bit lanes. */ +static __m128i abs_i16(__m128i x) { +#if PNG_INTEL_SSE_IMPLEMENTATION >= 2 + return _mm_abs_epi16(x); +#else + /* Read this all as, return x<0 ? -x : x. + * To negate two's complement, you flip all the bits then add 1. + */ + __m128i is_negative = _mm_cmplt_epi16(x, _mm_setzero_si128()); + + /* Flip negative lanes. */ + x = _mm_xor_si128(x, is_negative); + + /* +1 to negative lanes, else +0. */ + x = _mm_sub_epi16(x, is_negative); + return x; +#endif +} + +/* Bytewise c ? t : e. */ +static __m128i if_then_else(__m128i c, __m128i t, __m128i e) { +#if PNG_INTEL_SSE_IMPLEMENTATION >= 3 + return _mm_blendv_epi8(e,t,c); +#else + return _mm_or_si128(_mm_and_si128(c, t), _mm_andnot_si128(c, e)); +#endif +} + +void png_read_filter_row_paeth3_sse2(png_row_infop row_info, png_bytep row, + png_const_bytep prev) +{ + /* Paeth tries to predict pixel d using the pixel to the left of it, a, + * and two pixels from the previous row, b and c: + * prev: c b + * row: a d + * The Paeth function predicts d to be whichever of a, b, or c is nearest to + * p=a+b-c. + * + * The first pixel has no left context, and so uses an Up filter, p = b. + * This works naturally with our main loop's p = a+b-c if we force a and c + * to zero. + * Here we zero b and d, which become c and a respectively at the start of + * the loop. + */ + size_t rb; + const __m128i zero = _mm_setzero_si128(); + __m128i c, b = zero, + a, d = zero; + + png_debug(1, "in png_read_filter_row_paeth3_sse2"); + + rb = row_info->rowbytes; + while (rb >= 4) { + /* It's easiest to do this math (particularly, deal with pc) with 16-bit + * intermediates. + */ + __m128i pa,pb,pc,smallest,nearest; + c = b; b = _mm_unpacklo_epi8(load4(prev), zero); + a = d; d = _mm_unpacklo_epi8(load4(row ), zero); + + /* (p-a) == (a+b-c - a) == (b-c) */ + + pa = _mm_sub_epi16(b,c); + + /* (p-b) == (a+b-c - b) == (a-c) */ + pb = _mm_sub_epi16(a,c); + + /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */ + pc = _mm_add_epi16(pa,pb); + + pa = abs_i16(pa); /* |p-a| */ + pb = abs_i16(pb); /* |p-b| */ + pc = abs_i16(pc); /* |p-c| */ + + smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb)); + + /* Paeth breaks ties favoring a over b over c. */ + nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a, + if_then_else(_mm_cmpeq_epi16(smallest, pb), b, + c)); + + /* Note `_epi8`: we need addition to wrap modulo 255. */ + d = _mm_add_epi8(d, nearest); + store3(row, _mm_packus_epi16(d,d)); + + prev += 3; + row += 3; + rb -= 3; + } + if (rb > 0) { + /* It's easiest to do this math (particularly, deal with pc) with 16-bit + * intermediates. + */ + __m128i pa,pb,pc,smallest,nearest; + c = b; b = _mm_unpacklo_epi8(load3(prev), zero); + a = d; d = _mm_unpacklo_epi8(load3(row ), zero); + + /* (p-a) == (a+b-c - a) == (b-c) */ + pa = _mm_sub_epi16(b,c); + + /* (p-b) == (a+b-c - b) == (a-c) */ + pb = _mm_sub_epi16(a,c); + + /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */ + pc = _mm_add_epi16(pa,pb); + + pa = abs_i16(pa); /* |p-a| */ + pb = abs_i16(pb); /* |p-b| */ + pc = abs_i16(pc); /* |p-c| */ + + smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb)); + + /* Paeth breaks ties favoring a over b over c. */ + nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a, + if_then_else(_mm_cmpeq_epi16(smallest, pb), b, + c)); + + /* Note `_epi8`: we need addition to wrap modulo 255. */ + d = _mm_add_epi8(d, nearest); + store3(row, _mm_packus_epi16(d,d)); + + prev += 3; + row += 3; + rb -= 3; + } +} + +void png_read_filter_row_paeth4_sse2(png_row_infop row_info, png_bytep row, + png_const_bytep prev) +{ + /* Paeth tries to predict pixel d using the pixel to the left of it, a, + * and two pixels from the previous row, b and c: + * prev: c b + * row: a d + * The Paeth function predicts d to be whichever of a, b, or c is nearest to + * p=a+b-c. + * + * The first pixel has no left context, and so uses an Up filter, p = b. + * This works naturally with our main loop's p = a+b-c if we force a and c + * to zero. + * Here we zero b and d, which become c and a respectively at the start of + * the loop. + */ + size_t rb; + const __m128i zero = _mm_setzero_si128(); + __m128i pa,pb,pc,smallest,nearest; + __m128i c, b = zero, + a, d = zero; + + png_debug(1, "in png_read_filter_row_paeth4_sse2"); + + rb = row_info->rowbytes+4; + while (rb > 4) { + /* It's easiest to do this math (particularly, deal with pc) with 16-bit + * intermediates. + */ + c = b; b = _mm_unpacklo_epi8(load4(prev), zero); + a = d; d = _mm_unpacklo_epi8(load4(row ), zero); + + /* (p-a) == (a+b-c - a) == (b-c) */ + pa = _mm_sub_epi16(b,c); + + /* (p-b) == (a+b-c - b) == (a-c) */ + pb = _mm_sub_epi16(a,c); + + /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */ + pc = _mm_add_epi16(pa,pb); + + pa = abs_i16(pa); /* |p-a| */ + pb = abs_i16(pb); /* |p-b| */ + pc = abs_i16(pc); /* |p-c| */ + + smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb)); + + /* Paeth breaks ties favoring a over b over c. */ + nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a, + if_then_else(_mm_cmpeq_epi16(smallest, pb), b, + c)); + + /* Note `_epi8`: we need addition to wrap modulo 255. */ + d = _mm_add_epi8(d, nearest); + store4(row, _mm_packus_epi16(d,d)); + + prev += 4; + row += 4; + rb -= 4; + } +} + +#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */ +#endif /* READ */ diff --git a/media/libpng/intel/intel_init.c b/media/libpng/intel/intel_init.c new file mode 100644 index 0000000000..2f8168b7c4 --- /dev/null +++ b/media/libpng/intel/intel_init.c @@ -0,0 +1,52 @@ + +/* intel_init.c - SSE2 optimized filter functions + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 2016-2017 Glenn Randers-Pehrson + * Written by Mike Klein and Matt Sarett, Google, Inc. + * Derived from arm/arm_init.c + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED +#if PNG_INTEL_SSE_IMPLEMENTATION > 0 + +void +png_init_filter_functions_sse2(png_structp pp, unsigned int bpp) +{ + /* The techniques used to implement each of these filters in SSE operate on + * one pixel at a time. + * So they generally speed up 3bpp images about 3x, 4bpp images about 4x. + * They can scale up to 6 and 8 bpp images and down to 2 bpp images, + * but they'd not likely have any benefit for 1bpp images. + * Most of these can be implemented using only MMX and 64-bit registers, + * but they end up a bit slower than using the equally-ubiquitous SSE2. + */ + png_debug(1, "in png_init_filter_functions_sse2"); + if (bpp == 3) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_sse2; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_sse2; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth3_sse2; + } + else if (bpp == 4) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_sse2; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_sse2; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth4_sse2; + } + + /* No need optimize PNG_FILTER_VALUE_UP. The compiler should + * autovectorize. + */ +} + +#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */ +#endif /* PNG_READ_SUPPORTED */ diff --git a/media/libpng/libpng-manual.txt b/media/libpng/libpng-manual.txt new file mode 100644 index 0000000000..5dad92fbf7 --- /dev/null +++ b/media/libpng/libpng-manual.txt @@ -0,0 +1,5409 @@ +libpng-manual.txt - A description on how to use and modify libpng + + Copyright (c) 2018-2019 Cosmin Truta + Copyright (c) 1998-2018 Glenn Randers-Pehrson + + This document is released under the libpng license. + For conditions of distribution and use, see the disclaimer + and license in png.h + + Based on: + + libpng version 1.6.36, December 2018, through 1.6.37 - April 2019 + Updated and distributed by Cosmin Truta + Copyright (c) 2018-2019 Cosmin Truta + + libpng versions 0.97, January 1998, through 1.6.35 - July 2018 + Updated and distributed by Glenn Randers-Pehrson + Copyright (c) 1998-2018 Glenn Randers-Pehrson + + libpng 1.0 beta 6 - version 0.96 - May 28, 1997 + Updated and distributed by Andreas Dilger + Copyright (c) 1996, 1997 Andreas Dilger + + libpng 1.0 beta 2 - version 0.88 - January 26, 1996 + For conditions of distribution and use, see copyright + notice in png.h. Copyright (c) 1995, 1996 Guy Eric + Schalnat, Group 42, Inc. + + Updated/rewritten per request in the libpng FAQ + Copyright (c) 1995, 1996 Frank J. T. Wojcik + December 18, 1995 & January 20, 1996 + + TABLE OF CONTENTS + + I. Introduction + II. Structures + III. Reading + IV. Writing + V. Simplified API + VI. Modifying/Customizing libpng + VII. MNG support + VIII. Changes to Libpng from version 0.88 + IX. Changes to Libpng from version 1.0.x to 1.2.x + X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x + XI. Changes to Libpng from version 1.4.x to 1.5.x + XII. Changes to Libpng from version 1.5.x to 1.6.x + XIII. Detecting libpng + XIV. Source code repository + XV. Coding style + +I. Introduction + +This file describes how to use and modify the PNG reference library +(known as libpng) for your own use. In addition to this +file, example.c is a good starting point for using the library, as +it is heavily commented and should include everything most people +will need. We assume that libpng is already installed; see the +INSTALL file for instructions on how to configure and install libpng. + +For examples of libpng usage, see the files "example.c", "pngtest.c", +and the files in the "contrib" directory, all of which are included in +the libpng distribution. + +Libpng was written as a companion to the PNG specification, as a way +of reducing the amount of time and effort it takes to support the PNG +file format in application programs. + +The PNG specification (second edition), November 2003, is available as +a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2004 (E)) at +<https://www.w3.org/TR/2003/REC-PNG-20031110/>. +The W3C and ISO documents have identical technical content. + +The PNG-1.2 specification is available at +<https://png-mng.sourceforge.io/pub/png/spec/1.2/>. +It is technically equivalent +to the PNG specification (second edition) but has some additional material. + +The PNG-1.0 specification is available as RFC 2083 at +<https://png-mng.sourceforge.io/pub/png/spec/1.0/> and as a +W3C Recommendation at <https://www.w3.org/TR/REC-png-961001>. + +Some additional chunks are described in the special-purpose public chunks +documents at <http://www.libpng.org/pub/png/spec/register/> + +Other information +about PNG, and the latest version of libpng, can be found at the PNG home +page, <http://www.libpng.org/pub/png/>. + +Most users will not have to modify the library significantly; advanced +users may want to modify it more. All attempts were made to make it as +complete as possible, while keeping the code easy to understand. +Currently, this library only supports C. Support for other languages +is being considered. + +Libpng has been designed to handle multiple sessions at one time, +to be easily modifiable, to be portable to the vast majority of +machines (ANSI, K&R, 16-, 32-, and 64-bit) available, and to be easy +to use. The ultimate goal of libpng is to promote the acceptance of +the PNG file format in whatever way possible. While there is still +work to be done (see the TODO file), libpng should cover the +majority of the needs of its users. + +Libpng uses zlib for its compression and decompression of PNG files. +Further information about zlib, and the latest version of zlib, can +be found at the zlib home page, <https://zlib.net/>. +The zlib compression utility is a general purpose utility that is +useful for more than PNG files, and can be used without libpng. +See the documentation delivered with zlib for more details. +You can usually find the source files for the zlib utility wherever you +find the libpng source files. + +Libpng is thread safe, provided the threads are using different +instances of the structures. Each thread should have its own +png_struct and png_info instances, and thus its own image. +Libpng does not protect itself against two threads using the +same instance of a structure. + +II. Structures + +There are two main structures that are important to libpng, png_struct +and png_info. Both are internal structures that are no longer exposed +in the libpng interface (as of libpng 1.5.0). + +The png_info structure is designed to provide information about the +PNG file. At one time, the fields of png_info were intended to be +directly accessible to the user. However, this tended to cause problems +with applications using dynamically loaded libraries, and as a result +a set of interface functions for png_info (the png_get_*() and png_set_*() +functions) was developed, and direct access to the png_info fields was +deprecated.. + +The png_struct structure is the object used by the library to decode a +single image. As of 1.5.0 this structure is also not exposed. + +Almost all libpng APIs require a pointer to a png_struct as the first argument. +Many (in particular the png_set and png_get APIs) also require a pointer +to png_info as the second argument. Some application visible macros +defined in png.h designed for basic data access (reading and writing +integers in the PNG format) don't take a png_info pointer, but it's almost +always safe to assume that a (png_struct*) has to be passed to call an API +function. + +You can have more than one png_info structure associated with an image, +as illustrated in pngtest.c, one for information valid prior to the +IDAT chunks and another (called "end_info" below) for things after them. + +The png.h header file is an invaluable reference for programming with libpng. +And while I'm on the topic, make sure you include the libpng header file: + +#include <png.h> + +and also (as of libpng-1.5.0) the zlib header file, if you need it: + +#include <zlib.h> + +Types + +The png.h header file defines a number of integral types used by the +APIs. Most of these are fairly obvious; for example types corresponding +to integers of particular sizes and types for passing color values. + +One exception is how non-integral numbers are handled. For application +convenience most APIs that take such numbers have C (double) arguments; +however, internally PNG, and libpng, use 32 bit signed integers and encode +the value by multiplying by 100,000. As of libpng 1.5.0 a convenience +macro PNG_FP_1 is defined in png.h along with a type (png_fixed_point) +which is simply (png_int_32). + +All APIs that take (double) arguments also have a matching API that +takes the corresponding fixed point integer arguments. The fixed point +API has the same name as the floating point one with "_fixed" appended. +The actual range of values permitted in the APIs is frequently less than +the full range of (png_fixed_point) (-21474 to +21474). When APIs require +a non-negative argument the type is recorded as png_uint_32 above. Consult +the header file and the text below for more information. + +Special care must be take with sCAL chunk handling because the chunk itself +uses non-integral values encoded as strings containing decimal floating point +numbers. See the comments in the header file. + +Configuration + +The main header file function declarations are frequently protected by C +preprocessing directives of the form: + + #ifdef PNG_feature_SUPPORTED + declare-function + #endif + ... + #ifdef PNG_feature_SUPPORTED + use-function + #endif + +The library can be built without support for these APIs, although a +standard build will have all implemented APIs. Application programs +should check the feature macros before using an API for maximum +portability. From libpng 1.5.0 the feature macros set during the build +of libpng are recorded in the header file "pnglibconf.h" and this file +is always included by png.h. + +If you don't need to change the library configuration from the default, skip to +the next section ("Reading"). + +Notice that some of the makefiles in the 'scripts' directory and (in 1.5.0) all +of the build project files in the 'projects' directory simply copy +scripts/pnglibconf.h.prebuilt to pnglibconf.h. This means that these build +systems do not permit easy auto-configuration of the library - they only +support the default configuration. + +The easiest way to make minor changes to the libpng configuration when +auto-configuration is supported is to add definitions to the command line +using (typically) CPPFLAGS. For example: + +CPPFLAGS=-DPNG_NO_FLOATING_ARITHMETIC + +will change the internal libpng math implementation for gamma correction and +other arithmetic calculations to fixed point, avoiding the need for fast +floating point support. The result can be seen in the generated pnglibconf.h - +make sure it contains the changed feature macro setting. + +If you need to make more extensive configuration changes - more than one or two +feature macro settings - you can either add -DPNG_USER_CONFIG to the build +command line and put a list of feature macro settings in pngusr.h or you can set +DFA_XTRA (a makefile variable) to a file containing the same information in the +form of 'option' settings. + +A. Changing pnglibconf.h + +A variety of methods exist to build libpng. Not all of these support +reconfiguration of pnglibconf.h. To reconfigure pnglibconf.h it must either be +rebuilt from scripts/pnglibconf.dfa using awk or it must be edited by hand. + +Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt to +pnglibconf.h and changing the lines defining the supported features, paying +very close attention to the 'option' information in scripts/pnglibconf.dfa +that describes those features and their requirements. This is easy to get +wrong. + +B. Configuration using DFA_XTRA + +Rebuilding from pnglibconf.dfa is easy if a functioning 'awk', or a later +variant such as 'nawk' or 'gawk', is available. The configure build will +automatically find an appropriate awk and build pnglibconf.h. +The scripts/pnglibconf.mak file contains a set of make rules for doing the +same thing if configure is not used, and many of the makefiles in the scripts +directory use this approach. + +When rebuilding simply write a new file containing changed options and set +DFA_XTRA to the name of this file. This causes the build to append the new file +to the end of scripts/pnglibconf.dfa. The pngusr.dfa file should contain lines +of the following forms: + +everything = off + +This turns all optional features off. Include it at the start of pngusr.dfa to +make it easier to build a minimal configuration. You will need to turn at least +some features on afterward to enable either reading or writing code, or both. + +option feature on +option feature off + +Enable or disable a single feature. This will automatically enable other +features required by a feature that is turned on or disable other features that +require a feature which is turned off. Conflicting settings will cause an error +message to be emitted by awk. + +setting feature default value + +Changes the default value of setting 'feature' to 'value'. There are a small +number of settings listed at the top of pnglibconf.h, they are documented in the +source code. Most of these values have performance implications for the library +but most of them have no visible effect on the API. Some can also be overridden +from the API. + +This method of building a customized pnglibconf.h is illustrated in +contrib/pngminim/*. See the "$(PNGCONF):" target in the makefile and +pngusr.dfa in these directories. + +C. Configuration using PNG_USER_CONFIG + +If -DPNG_USER_CONFIG is added to the CPPFLAGS when pnglibconf.h is built, +the file pngusr.h will automatically be included before the options in +scripts/pnglibconf.dfa are processed. Your pngusr.h file should contain only +macro definitions turning features on or off or setting settings. + +Apart from the global setting "everything = off" all the options listed above +can be set using macros in pngusr.h: + +#define PNG_feature_SUPPORTED + +is equivalent to: + +option feature on + +#define PNG_NO_feature + +is equivalent to: + +option feature off + +#define PNG_feature value + +is equivalent to: + +setting feature default value + +Notice that in both cases, pngusr.dfa and pngusr.h, the contents of the +pngusr file you supply override the contents of scripts/pnglibconf.dfa + +If confusing or incomprehensible behavior results it is possible to +examine the intermediate file pnglibconf.dfn to find the full set of +dependency information for each setting and option. Simply locate the +feature in the file and read the C comments that precede it. + +This method is also illustrated in the contrib/pngminim/* makefiles and +pngusr.h. + +III. Reading + +We'll now walk you through the possible functions to call when reading +in a PNG file sequentially, briefly explaining the syntax and purpose +of each one. See example.c and png.h for more detail. While +progressive reading is covered in the next section, you will still +need some of the functions discussed in this section to read a PNG +file. + +Setup + +You will want to do the I/O initialization(*) before you get into libpng, +so if it doesn't work, you don't have much to undo. Of course, you +will also want to insure that you are, in fact, dealing with a PNG +file. Libpng provides a simple check to see if a file is a PNG file. +To use it, pass in the first 1 to 8 bytes of the file to the function +png_sig_cmp(), and it will return 0 (false) if the bytes match the +corresponding bytes of the PNG signature, or nonzero (true) otherwise. +Of course, the more bytes you pass in, the greater the accuracy of the +prediction. + +If you are intending to keep the file pointer open for use in libpng, +you must ensure you don't read more than 8 bytes from the beginning +of the file, and you also have to make a call to png_set_sig_bytes() +with the number of bytes you read from the beginning. Libpng will +then only check the bytes (if any) that your program didn't read. + +(*): If you are not using the standard I/O functions, you will need +to replace them with custom functions. See the discussion under +Customizing libpng. + + FILE *fp = fopen(file_name, "rb"); + if (!fp) + { + return ERROR; + } + + if (fread(header, 1, number, fp) != number) + { + return ERROR; + } + + is_png = !png_sig_cmp(header, 0, number); + if (!is_png) + { + return NOT_PNG; + } + +Next, png_struct and png_info need to be allocated and initialized. In +order to ensure that the size of these structures is correct even with a +dynamically linked libpng, there are functions to initialize and +allocate the structures. We also pass the library version, optional +pointers to error handling functions, and a pointer to a data struct for +use by the error functions, if necessary (the pointer and functions can +be NULL if the default error handlers are to be used). See the section +on Changes to Libpng below regarding the old initialization functions. +The structure allocation functions quietly return NULL if they fail to +create the structure, so your application should check for that. + + png_structp png_ptr = png_create_read_struct + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn); + + if (!png_ptr) + return ERROR; + + png_infop info_ptr = png_create_info_struct(png_ptr); + + if (!info_ptr) + { + png_destroy_read_struct(&png_ptr, + (png_infopp)NULL, (png_infopp)NULL); + return ERROR; + } + +If you want to use your own memory allocation routines, +use a libpng that was built with PNG_USER_MEM_SUPPORTED defined, and use +png_create_read_struct_2() instead of png_create_read_struct(): + + png_structp png_ptr = png_create_read_struct_2 + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn, (png_voidp) + user_mem_ptr, user_malloc_fn, user_free_fn); + +The error handling routines passed to png_create_read_struct() +and the memory alloc/free routines passed to png_create_struct_2() +are only necessary if you are not using the libpng supplied error +handling and memory alloc/free functions. + +When libpng encounters an error, it expects to longjmp back +to your routine. Therefore, you will need to call setjmp and pass +your png_jmpbuf(png_ptr). If you read the file from different +routines, you will need to update the longjmp buffer every time you enter +a new routine that will call a png_*() function. + +See your documentation of setjmp/longjmp for your compiler for more +information on setjmp/longjmp. See the discussion on libpng error +handling in the Customizing Libpng section below for more information +on the libpng error handling. If an error occurs, and libpng longjmp's +back to your setjmp, you will want to call png_destroy_read_struct() to +free any memory. + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + &end_info); + fclose(fp); + return ERROR; + } + +Pass (png_infopp)NULL instead of &end_info if you didn't create +an end_info structure. + +If you would rather avoid the complexity of setjmp/longjmp issues, +you can compile libpng with PNG_NO_SETJMP, in which case +errors will result in a call to PNG_ABORT() which defaults to abort(). + +You can #define PNG_ABORT() to a function that does something +more useful than abort(), as long as your function does not +return. + +Now you need to set up the input code. The default for libpng is to +use the C function fread(). If you use this, you will need to pass a +valid FILE * in the function png_init_io(). Be sure that the file is +opened in binary mode. If you wish to handle reading data in another +way, you need not call the png_init_io() function, but you must then +implement the libpng I/O methods discussed in the Customizing Libpng +section below. + + png_init_io(png_ptr, fp); + +If you had previously opened the file and read any of the signature from +the beginning in order to see if this was a PNG file, you need to let +libpng know that there are some bytes missing from the start of the file. + + png_set_sig_bytes(png_ptr, number); + +You can change the zlib compression buffer size to be used while +reading compressed data with + + png_set_compression_buffer_size(png_ptr, buffer_size); + +where the default size is 8192 bytes. Note that the buffer size +is changed immediately and the buffer is reallocated immediately, +instead of setting a flag to be acted upon later. + +If you want CRC errors to be handled in a different manner than +the default, use + + png_set_crc_action(png_ptr, crit_action, ancil_action); + +The values for png_set_crc_action() say how libpng is to handle CRC errors in +ancillary and critical chunks, and whether to use the data contained +therein. Starting with libpng-1.6.26, this also governs how an ADLER32 error +is handled while reading the IDAT chunk. Note that it is impossible to +"discard" data in a critical chunk. + +Choices for (int) crit_action are + PNG_CRC_DEFAULT 0 error/quit + PNG_CRC_ERROR_QUIT 1 error/quit + PNG_CRC_WARN_USE 3 warn/use data + PNG_CRC_QUIET_USE 4 quiet/use data + PNG_CRC_NO_CHANGE 5 use the current value + +Choices for (int) ancil_action are + PNG_CRC_DEFAULT 0 error/quit + PNG_CRC_ERROR_QUIT 1 error/quit + PNG_CRC_WARN_DISCARD 2 warn/discard data + PNG_CRC_WARN_USE 3 warn/use data + PNG_CRC_QUIET_USE 4 quiet/use data + PNG_CRC_NO_CHANGE 5 use the current value + +When the setting for crit_action is PNG_CRC_QUIET_USE, the CRC and ADLER32 +checksums are not only ignored, but they are not evaluated. + +Setting up callback code + +You can set up a callback function to handle any unknown chunks in the +input stream. You must supply the function + + read_chunk_callback(png_structp png_ptr, + png_unknown_chunkp chunk); + { + /* The unknown chunk structure contains your + chunk data, along with similar data for any other + unknown chunks: */ + + png_byte name[5]; + png_byte *data; + size_t size; + + /* Note that libpng has already taken care of + the CRC handling */ + + /* put your code here. Search for your chunk in the + unknown chunk structure, process it, and return one + of the following: */ + + return -n; /* chunk had an error */ + return 0; /* did not recognize */ + return n; /* success */ + } + +(You can give your function another name that you like instead of +"read_chunk_callback") + +To inform libpng about your function, use + + png_set_read_user_chunk_fn(png_ptr, user_chunk_ptr, + read_chunk_callback); + +This names not only the callback function, but also a user pointer that +you can retrieve with + + png_get_user_chunk_ptr(png_ptr); + +If you call the png_set_read_user_chunk_fn() function, then all unknown +chunks which the callback does not handle will be saved when read. You can +cause them to be discarded by returning '1' ("handled") instead of '0'. This +behavior will change in libpng 1.7 and the default handling set by the +png_set_keep_unknown_chunks() function, described below, will be used when the +callback returns 0. If you want the existing behavior you should set the global +default to PNG_HANDLE_CHUNK_IF_SAFE now; this is compatible with all current +versions of libpng and with 1.7. Libpng 1.6 issues a warning if you keep the +default, or PNG_HANDLE_CHUNK_NEVER, and the callback returns 0. + +At this point, you can set up a callback function that will be +called after each row has been read, which you can use to control +a progress meter or the like. It's demonstrated in pngtest.c. +You must supply a function + + void read_row_callback(png_structp png_ptr, + png_uint_32 row, int pass); + { + /* put your code here */ + } + +(You can give it another name that you like instead of "read_row_callback") + +To inform libpng about your function, use + + png_set_read_status_fn(png_ptr, read_row_callback); + +When this function is called the row has already been completely processed and +the 'row' and 'pass' refer to the next row to be handled. For the +non-interlaced case the row that was just handled is simply one less than the +passed in row number, and pass will always be 0. For the interlaced case the +same applies unless the row value is 0, in which case the row just handled was +the last one from one of the preceding passes. Because interlacing may skip a +pass you cannot be sure that the preceding pass is just 'pass-1'; if you really +need to know what the last pass is record (row,pass) from the callback and use +the last recorded value each time. + +As with the user transform you can find the output row using the +PNG_ROW_FROM_PASS_ROW macro. + +Unknown-chunk handling + +Now you get to set the way the library processes unknown chunks in the +input PNG stream. Both known and unknown chunks will be read. Normal +behavior is that known chunks will be parsed into information in +various info_ptr members while unknown chunks will be discarded. This +behavior can be wasteful if your application will never use some known +chunk types. To change this, you can call: + + png_set_keep_unknown_chunks(png_ptr, keep, + chunk_list, num_chunks); + + keep - 0: default unknown chunk handling + 1: ignore; do not keep + 2: keep only if safe-to-copy + 3: keep even if unsafe-to-copy + + You can use these definitions: + PNG_HANDLE_CHUNK_AS_DEFAULT 0 + PNG_HANDLE_CHUNK_NEVER 1 + PNG_HANDLE_CHUNK_IF_SAFE 2 + PNG_HANDLE_CHUNK_ALWAYS 3 + + chunk_list - list of chunks affected (a byte string, + five bytes per chunk, NULL or '\0' if + num_chunks is positive; ignored if + numchunks <= 0). + + num_chunks - number of chunks affected; if 0, all + unknown chunks are affected. If positive, + only the chunks in the list are affected, + and if negative all unknown chunks and + all known chunks except for the IHDR, + PLTE, tRNS, IDAT, and IEND chunks are + affected. + +Unknown chunks declared in this way will be saved as raw data onto a +list of png_unknown_chunk structures. If a chunk that is normally +known to libpng is named in the list, it will be handled as unknown, +according to the "keep" directive. If a chunk is named in successive +instances of png_set_keep_unknown_chunks(), the final instance will +take precedence. The IHDR and IEND chunks should not be named in +chunk_list; if they are, libpng will process them normally anyway. +If you know that your application will never make use of some particular +chunks, use PNG_HANDLE_CHUNK_NEVER (or 1) as demonstrated below. + +Here is an example of the usage of png_set_keep_unknown_chunks(), +where the private "vpAg" chunk will later be processed by a user chunk +callback function: + + png_byte vpAg[5]={118, 112, 65, 103, (png_byte) '\0'}; + + #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) + png_byte unused_chunks[]= + { + 104, 73, 83, 84, (png_byte) '\0', /* hIST */ + 105, 84, 88, 116, (png_byte) '\0', /* iTXt */ + 112, 67, 65, 76, (png_byte) '\0', /* pCAL */ + 115, 67, 65, 76, (png_byte) '\0', /* sCAL */ + 115, 80, 76, 84, (png_byte) '\0', /* sPLT */ + 116, 73, 77, 69, (png_byte) '\0', /* tIME */ + }; + #endif + + ... + + #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) + /* ignore all unknown chunks + * (use global setting "2" for libpng16 and earlier): + */ + png_set_keep_unknown_chunks(read_ptr, 2, NULL, 0); + + /* except for vpAg: */ + png_set_keep_unknown_chunks(read_ptr, 2, vpAg, 1); + + /* also ignore unused known chunks: */ + png_set_keep_unknown_chunks(read_ptr, 1, unused_chunks, + (int)(sizeof unused_chunks)/5); + #endif + +User limits + +The PNG specification allows the width and height of an image to be as +large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns. +For safety, libpng imposes a default limit of 1 million rows and columns. +Larger images will be rejected immediately with a png_error() call. If +you wish to change these limits, you can use + + png_set_user_limits(png_ptr, width_max, height_max); + +to set your own limits (libpng may reject some very wide images +anyway because of potential buffer overflow conditions). + +You should put this statement after you create the PNG structure and +before calling png_read_info(), png_read_png(), or png_process_data(). + +When writing a PNG datastream, put this statement before calling +png_write_info() or png_write_png(). + +If you need to retrieve the limits that are being applied, use + + width_max = png_get_user_width_max(png_ptr); + height_max = png_get_user_height_max(png_ptr); + +The PNG specification sets no limit on the number of ancillary chunks +allowed in a PNG datastream. By default, libpng imposes a limit of +a total of 1000 sPLT, tEXt, iTXt, zTXt, and unknown chunks to be stored. +If you have set up both info_ptr and end_info_ptr, the limit applies +separately to each. You can change the limit on the total number of such +chunks that will be stored, with + + png_set_chunk_cache_max(png_ptr, user_chunk_cache_max); + +where 0x7fffffffL means unlimited. You can retrieve this limit with + + chunk_cache_max = png_get_chunk_cache_max(png_ptr); + +Libpng imposes a limit of 8 Megabytes (8,000,000 bytes) on the amount of +memory that any chunk other than IDAT can occupy, originally or when +decompressed (prior to libpng-1.6.32 the limit was only applied to compressed +chunks after decompression). You can change this limit with + + png_set_chunk_malloc_max(png_ptr, user_chunk_malloc_max); + +and you can retrieve the limit with + + chunk_malloc_max = png_get_chunk_malloc_max(png_ptr); + +Any chunks that would cause either of these limits to be exceeded will +be ignored. + +Information about your system + +If you intend to display the PNG or to incorporate it in other image data you +need to tell libpng information about your display or drawing surface so that +libpng can convert the values in the image to match the display. + +From libpng-1.5.4 this information can be set before reading the PNG file +header. In earlier versions png_set_gamma() existed but behaved incorrectly if +called before the PNG file header had been read and png_set_alpha_mode() did not +exist. + +If you need to support versions prior to libpng-1.5.4 test the version number +as illustrated below using "PNG_LIBPNG_VER >= 10504" and follow the procedures +described in the appropriate manual page. + +You give libpng the encoding expected by your system expressed as a 'gamma' +value. You can also specify a default encoding for the PNG file in +case the required information is missing from the file. By default libpng +assumes that the PNG data matches your system, to keep this default call: + + png_set_gamma(png_ptr, screen_gamma, output_gamma); + +or you can use the fixed point equivalent: + + png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, + PNG_FP_1*output_gamma); + +If you don't know the gamma for your system it is probably 2.2 - a good +approximation to the IEC standard for display systems (sRGB). If images are +too contrasty or washed out you got the value wrong - check your system +documentation! + +Many systems permit the system gamma to be changed via a lookup table in the +display driver, a few systems, including older Macs, change the response by +default. As of 1.5.4 three special values are available to handle common +situations: + + PNG_DEFAULT_sRGB: Indicates that the system conforms to the + IEC 61966-2-1 standard. This matches almost + all systems. + PNG_GAMMA_MAC_18: Indicates that the system is an older + (pre Mac OS 10.6) Apple Macintosh system with + the default settings. + PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates + that the system expects data with no gamma + encoding. + +You would use the linear (unencoded) value if you need to process the pixel +values further because this avoids the need to decode and re-encode each +component value whenever arithmetic is performed. A lot of graphics software +uses linear values for this reason, often with higher precision component values +to preserve overall accuracy. + + +The output_gamma value expresses how to decode the output values, not how +they are encoded. The values used correspond to the normal numbers used to +describe the overall gamma of a computer display system; for example 2.2 for +an sRGB conformant system. The values are scaled by 100000 in the _fixed +version of the API (so 220000 for sRGB.) + +The inverse of the value is always used to provide a default for the PNG file +encoding if it has no gAMA chunk and if png_set_gamma() has not been called +to override the PNG gamma information. + +When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode +opaque pixels however pixels with lower alpha values are not encoded, +regardless of the output gamma setting. + +When the standard Porter Duff handling is requested with mode 1 the output +encoding is set to be linear and the output_gamma value is only relevant +as a default for input data that has no gamma information. The linear output +encoding will be overridden if png_set_gamma() is called - the results may be +highly unexpected! + +The following numbers are derived from the sRGB standard and the research +behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of +0.45455 (1/2.2) for PNG. The value implicitly includes any viewing +correction required to take account of any differences in the color +environment of the original scene and the intended display environment; the +value expresses how to *decode* the image for display, not how the original +data was *encoded*. + +sRGB provides a peg for the PNG standard by defining a viewing environment. +sRGB itself, and earlier TV standards, actually use a more complex transform +(a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is +limited to simple power laws.) By saying that an image for direct display on +an sRGB conformant system should be stored with a gAMA chunk value of 45455 +(11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification +makes it possible to derive values for other display systems and +environments. + +The Mac value is deduced from the sRGB based on an assumption that the actual +extra viewing correction used in early Mac display systems was implemented as +a power 1.45 lookup table. + +Any system where a programmable lookup table is used or where the behavior of +the final display device characteristics can be changed requires system +specific code to obtain the current characteristic. However this can be +difficult and most PNG gamma correction only requires an approximate value. + +By default, if png_set_alpha_mode() is not called, libpng assumes that all +values are unencoded, linear, values and that the output device also has a +linear characteristic. This is only very rarely correct - it is invariably +better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the +default if you don't know what the right answer is! + +The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS +10.6) which used a correction table to implement a somewhat lower gamma on an +otherwise sRGB system. + +Both these values are reserved (not simple gamma values) in order to allow +more precise correction internally in the future. + +NOTE: the values can be passed to either the fixed or floating +point APIs, but the floating point API will also accept floating point +values. + +The second thing you may need to tell libpng about is how your system handles +alpha channel information. Some, but not all, PNG files contain an alpha +channel. To display these files correctly you need to compose the data onto a +suitable background, as described in the PNG specification. + +Libpng only supports composing onto a single color (using png_set_background; +see below). Otherwise you must do the composition yourself and, in this case, +you may need to call png_set_alpha_mode: + + #if PNG_LIBPNG_VER >= 10504 + png_set_alpha_mode(png_ptr, mode, screen_gamma); + #else + png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma); + #endif + +The screen_gamma value is the same as the argument to png_set_gamma; however, +how it affects the output depends on the mode. png_set_alpha_mode() sets the +file gamma default to 1/screen_gamma, so normally you don't need to call +png_set_gamma. If you need different defaults call png_set_gamma() before +png_set_alpha_mode() - if you call it after it will override the settings made +by png_set_alpha_mode(). + +The mode is as follows: + + PNG_ALPHA_PNG: The data is encoded according to the PNG +specification. Red, green and blue, or gray, components are +gamma encoded color values and are not premultiplied by the +alpha value. The alpha value is a linear measure of the +contribution of the pixel to the corresponding final output pixel. + +You should normally use this format if you intend to perform +color correction on the color values; most, maybe all, color +correction software has no handling for the alpha channel and, +anyway, the math to handle pre-multiplied component values is +unnecessarily complex. + +Before you do any arithmetic on the component values you need +to remove the gamma encoding and multiply out the alpha +channel. See the PNG specification for more detail. It is +important to note that when an image with an alpha channel is +scaled, linear encoded, pre-multiplied component values must +be used! + +The remaining modes assume you don't need to do any further color correction or +that if you do, your color correction software knows all about alpha (it +probably doesn't!). They 'associate' the alpha with the color information by +storing color channel values that have been scaled by the alpha. The +advantage is that the color channels can be resampled (the image can be +scaled) in this form. The disadvantage is that normal practice is to store +linear, not (gamma) encoded, values and this requires 16-bit channels for +still images rather than the 8-bit channels that are just about sufficient if +gamma encoding is used. In addition all non-transparent pixel values, +including completely opaque ones, must be gamma encoded to produce the final +image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes +described below (the latter being the two common names for associated alpha +color channels). Note that PNG files always contain non-associated color +channels; png_set_alpha_mode() with one of the modes causes the decoder to +convert the pixels to an associated form before returning them to your +application. + +Since it is not necessary to perform arithmetic on opaque color values so +long as they are not to be resampled and are in the final color space it is +possible to optimize the handling of alpha by storing the opaque pixels in +the PNG format (adjusted for the output color space) while storing partially +opaque pixels in the standard, linear, format. The accuracy required for +standard alpha composition is relatively low, because the pixels are +isolated, therefore typically the accuracy loss in storing 8-bit linear +values is acceptable. (This is not true if the alpha channel is used to +simulate transparency over large areas - use 16 bits or the PNG mode in +this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is +treated as opaque only if the alpha value is equal to the maximum value. + + PNG_ALPHA_STANDARD: The data libpng produces is encoded in the +standard way assumed by most correctly written graphics software. +The gamma encoding will be removed by libpng and the +linear component values will be pre-multiplied by the +alpha channel. + +With this format the final image must be re-encoded to +match the display gamma before the image is displayed. +If your system doesn't do that, yet still seems to +perform arithmetic on the pixels without decoding them, +it is broken - check out the modes below. + +With PNG_ALPHA_STANDARD libpng always produces linear +component values, whatever screen_gamma you supply. The +screen_gamma value is, however, used as a default for +the file gamma if the PNG file has no gamma information. + +If you call png_set_gamma() after png_set_alpha_mode() you +will override the linear encoding. Instead the +pre-multiplied pixel values will be gamma encoded but +the alpha channel will still be linear. This may +actually match the requirements of some broken software, +but it is unlikely. + +While linear 8-bit data is often used it has +insufficient precision for any image with a reasonable +dynamic range. To avoid problems, and if your software +supports it, use png_set_expand_16() to force all +components to 16 bits. + + PNG_ALPHA_OPTIMIZED: This mode is the same as PNG_ALPHA_STANDARD +except that completely opaque pixels are gamma encoded according to +the screen_gamma value. Pixels with alpha less than 1.0 +will still have linear components. + +Use this format if you have control over your +compositing software and so don't do other arithmetic +(such as scaling) on the data you get from libpng. Your +compositing software can simply copy opaque pixels to +the output but still has linear values for the +non-opaque pixels. + +In normal compositing, where the alpha channel encodes +partial pixel coverage (as opposed to broad area +translucency), the inaccuracies of the 8-bit +representation of non-opaque pixels are irrelevant. + +You can also try this format if your software is broken; +it might look better. + + PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD; however, all component +values, including the alpha channel are gamma encoded. This is +broken because, in practice, no implementation that uses this choice +correctly undoes the encoding before handling alpha composition. Use this +choice only if other serious errors in the software or hardware you use +mandate it. In most cases of broken software or hardware the bug in the +final display manifests as a subtle halo around composited parts of the +image. You may not even perceive this as a halo; the composited part of +the image may simply appear separate from the background, as though it had +been cut out of paper and pasted on afterward. + +If you don't have to deal with bugs in software or hardware, or if you can fix +them, there are three recommended ways of using png_set_alpha_mode(): + + png_set_alpha_mode(png_ptr, PNG_ALPHA_PNG, + screen_gamma); + +You can do color correction on the result (libpng does not currently +support color correction internally). When you handle the alpha channel +you need to undo the gamma encoding and multiply out the alpha. + + png_set_alpha_mode(png_ptr, PNG_ALPHA_STANDARD, + screen_gamma); + png_set_expand_16(png_ptr); + +If you are using the high level interface, don't call png_set_expand_16(); +instead pass PNG_TRANSFORM_EXPAND_16 to the interface. + +With this mode you can't do color correction, but you can do arithmetic, +including composition and scaling, on the data without further processing. + + png_set_alpha_mode(png_ptr, PNG_ALPHA_OPTIMIZED, + screen_gamma); + +You can avoid the expansion to 16-bit components with this mode, but you +lose the ability to scale the image or perform other linear arithmetic. +All you can do is compose the result onto a matching output. Since this +mode is libpng-specific you also need to write your own composition +software. + +The following are examples of calls to png_set_alpha_mode to achieve the +required overall gamma correction and, where necessary, alpha +premultiplication. + + png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); + +Choices for the alpha_mode are + + PNG_ALPHA_PNG 0 /* according to the PNG standard */ + PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ + PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ + PNG_ALPHA_PREMULTIPLIED 1 /* as above */ + PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ + PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ + +PNG_ALPHA_PNG is the default libpng handling of the alpha channel. It is not +pre-multiplied into the color components. In addition the call states +that the output is for a sRGB system and causes all PNG files without gAMA +chunks to be assumed to be encoded using sRGB. + + png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); + +In this case the output is assumed to be something like an sRGB conformant +display preceded by a power-law lookup table of power 1.45. This is how +early Mac systems behaved. + + png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); + +This is the classic Jim Blinn approach and will work in academic +environments where everything is done by the book. It has the shortcoming +of assuming that input PNG data with no gamma information is linear - this +is unlikely to be correct unless the PNG files were generated locally. +Most of the time the output precision will be so low as to show +significant banding in dark areas of the image. + + png_set_expand_16(pp); + png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); + +This is a somewhat more realistic Jim Blinn inspired approach. PNG files +are assumed to have the sRGB encoding if not marked with a gamma value and +the output is always 16 bits per component. This permits accurate scaling +and processing of the data. If you know that your input PNG files were +generated locally you might need to replace PNG_DEFAULT_sRGB with the +correct value for your system. + + png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); + +If you just need to composite the PNG image onto an existing background +and if you control the code that does this you can use the optimization +setting. In this case you just copy completely opaque pixels to the +output. For pixels that are not completely transparent (you just skip +those) you do the composition math using png_composite or png_composite_16 +below then encode the resultant 8-bit or 16-bit values to match the output +encoding. + + Other cases + +If neither the PNG nor the standard linear encoding work for you because +of the software or hardware you use then you have a big problem. The PNG +case will probably result in halos around the image. The linear encoding +will probably result in a washed out, too bright, image (it's actually too +contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably +substantially reduce the halos. Alternatively try: + + png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); + +This option will also reduce the halos, but there will be slight dark +halos round the opaque parts of the image where the background is light. +In the OPTIMIZED mode the halos will be light halos where the background +is dark. Take your pick - the halos are unavoidable unless you can get +your hardware/software fixed! (The OPTIMIZED approach is slightly +faster.) + +When the default gamma of PNG files doesn't match the output gamma. +If you have PNG files with no gamma information png_set_alpha_mode allows +you to provide a default gamma, but it also sets the output gamma to the +matching value. If you know your PNG files have a gamma that doesn't +match the output you can take advantage of the fact that +png_set_alpha_mode always sets the output gamma but only sets the PNG +default if it is not already set: + + png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); + png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); + +The first call sets both the default and the output gamma values, the +second call overrides the output gamma without changing the default. This +is easier than achieving the same effect with png_set_gamma. You must use +PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will +fire if more than one call to png_set_alpha_mode and png_set_background is +made in the same read operation, however multiple calls with PNG_ALPHA_PNG +are ignored. + +If you don't need, or can't handle, the alpha channel you can call +png_set_background() to remove it by compositing against a fixed color. Don't +call png_set_strip_alpha() to do this - it will leave spurious pixel values in +transparent parts of this image. + + png_set_background(png_ptr, &background_color, + PNG_BACKGROUND_GAMMA_SCREEN, 0, 1); + +The background_color is an RGB or grayscale value according to the data format +libpng will produce for you. Because you don't yet know the format of the PNG +file, if you call png_set_background at this point you must arrange for the +format produced by libpng to always have 8-bit or 16-bit components and then +store the color as an 8-bit or 16-bit color as appropriate. The color contains +separate gray and RGB component values, so you can let libpng produce gray or +RGB output according to the input format, but low bit depth grayscale images +must always be converted to at least 8-bit format. (Even though low bit depth +grayscale images can't have an alpha channel they can have a transparent +color!) + +You set the transforms you need later, either as flags to the high level +interface or libpng API calls for the low level interface. For reference the +settings and API calls required are: + +8-bit values: + PNG_TRANSFORM_SCALE_16 | PNG_EXPAND + png_set_expand(png_ptr); png_set_scale_16(png_ptr); + + If you must get exactly the same inaccurate results + produced by default in versions prior to libpng-1.5.4, + use PNG_TRANSFORM_STRIP_16 and png_set_strip_16(png_ptr) + instead. + +16-bit values: + PNG_TRANSFORM_EXPAND_16 + png_set_expand_16(png_ptr); + +In either case palette image data will be expanded to RGB. If you just want +color data you can add PNG_TRANSFORM_GRAY_TO_RGB or png_set_gray_to_rgb(png_ptr) +to the list. + +Calling png_set_background before the PNG file header is read will not work +prior to libpng-1.5.4. Because the failure may result in unexpected warnings or +errors it is therefore much safer to call png_set_background after the head has +been read. Unfortunately this means that prior to libpng-1.5.4 it cannot be +used with the high level interface. + +The high-level read interface + +At this point there are two ways to proceed; through the high-level +read interface, or through a sequence of low-level read operations. +You can use the high-level interface if (a) you are willing to read +the entire image into memory, and (b) the input transformations +you want to do are limited to the following set: + + PNG_TRANSFORM_IDENTITY No transformation + PNG_TRANSFORM_SCALE_16 Strip 16-bit samples to + 8-bit accurately + PNG_TRANSFORM_STRIP_16 Chop 16-bit samples to + 8-bit less accurately + PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel + PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit + samples to bytes + PNG_TRANSFORM_PACKSWAP Change order of packed + pixels to LSB first + PNG_TRANSFORM_EXPAND Perform set_expand() + PNG_TRANSFORM_INVERT_MONO Invert monochrome images + PNG_TRANSFORM_SHIFT Normalize pixels to the + sBIT depth + PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA + to BGRA + PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA + to AG + PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity + to transparency + PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples + PNG_TRANSFORM_GRAY_TO_RGB Expand grayscale samples + to RGB (or GA to RGBA) + PNG_TRANSFORM_EXPAND_16 Expand samples to 16 bits + +(This excludes setting a background color, doing gamma transformation, +quantizing, and setting filler.) If this is the case, simply do this: + + png_read_png(png_ptr, info_ptr, png_transforms, NULL) + +where png_transforms is an integer containing the bitwise OR of some +set of transformation flags. This call is equivalent to png_read_info(), +followed the set of transformations indicated by the transform mask, +then png_read_image(), and finally png_read_end(). + +(The final parameter of this call is not yet used. Someday it might point +to transformation parameters required by some future input transform.) + +You must use png_transforms and not call any png_set_transform() functions +when you use png_read_png(). + +After you have called png_read_png(), you can retrieve the image data +with + + row_pointers = png_get_rows(png_ptr, info_ptr); + +where row_pointers is an array of pointers to the pixel data for each row: + + png_bytep row_pointers[height]; + +If you know your image size and pixel size ahead of time, you can allocate +row_pointers prior to calling png_read_png() with + + if (height > PNG_UINT_32_MAX/(sizeof (png_byte))) + png_error (png_ptr, + "Image is too tall to process in memory"); + + if (width > PNG_UINT_32_MAX/pixel_size) + png_error (png_ptr, + "Image is too wide to process in memory"); + + row_pointers = png_malloc(png_ptr, + height*(sizeof (png_bytep))); + + for (int i=0; i<height, i++) + row_pointers[i]=NULL; /* security precaution */ + + for (int i=0; i<height, i++) + row_pointers[i]=png_malloc(png_ptr, + width*pixel_size); + + png_set_rows(png_ptr, info_ptr, &row_pointers); + +Alternatively you could allocate your image in one big block and define +row_pointers[i] to point into the proper places in your block, but first +be sure that your platform is able to allocate such a large buffer: + + /* Guard against integer overflow */ + if (height > PNG_SIZE_MAX/(width*pixel_size)) { + png_error(png_ptr,"image_data buffer would be too large"); + } + + png_bytep buffer=png_malloc(png_ptr,height*width*pixel_size); + + for (int i=0; i<height, i++) + row_pointers[i]=buffer+i*width*pixel_size; + + png_set_rows(png_ptr, info_ptr, &row_pointers); + +If you use png_set_rows(), the application is responsible for freeing +row_pointers (and row_pointers[i], if they were separately allocated). + +If you don't allocate row_pointers ahead of time, png_read_png() will +do it, and it'll be free'ed by libpng when you call png_destroy_*(). + +The low-level read interface + +If you are going the low-level route, you are now ready to read all +the file information up to the actual image data. You do this with a +call to png_read_info(). + + png_read_info(png_ptr, info_ptr); + +This will process all chunks up to but not including the image data. + +This also copies some of the data from the PNG file into the decode structure +for use in later transformations. Important information copied in is: + +1) The PNG file gamma from the gAMA chunk. This overwrites the default value +provided by an earlier call to png_set_gamma or png_set_alpha_mode. + +2) Prior to libpng-1.5.4 the background color from a bKGd chunk. This +damages the information provided by an earlier call to png_set_background +resulting in unexpected behavior. Libpng-1.5.4 no longer does this. + +3) The number of significant bits in each component value. Libpng uses this to +optimize gamma handling by reducing the internal lookup table sizes. + +4) The transparent color information from a tRNS chunk. This can be modified by +a later call to png_set_tRNS. + +Querying the info structure + +Functions are used to get the information from the info_ptr once it +has been read. Note that these fields may not be completely filled +in until png_read_end() has read the chunk data following the image. + + png_get_IHDR(png_ptr, info_ptr, &width, &height, + &bit_depth, &color_type, &interlace_type, + &compression_type, &filter_method); + + width - holds the width of the image + in pixels (up to 2^31). + + height - holds the height of the image + in pixels (up to 2^31). + + bit_depth - holds the bit depth of one of the + image channels. (valid values are + 1, 2, 4, 8, 16 and depend also on + the color_type. See also + significant bits (sBIT) below). + + color_type - describes which color/alpha channels + are present. + PNG_COLOR_TYPE_GRAY + (bit depths 1, 2, 4, 8, 16) + PNG_COLOR_TYPE_GRAY_ALPHA + (bit depths 8, 16) + PNG_COLOR_TYPE_PALETTE + (bit depths 1, 2, 4, 8) + PNG_COLOR_TYPE_RGB + (bit_depths 8, 16) + PNG_COLOR_TYPE_RGB_ALPHA + (bit_depths 8, 16) + + PNG_COLOR_MASK_PALETTE + PNG_COLOR_MASK_COLOR + PNG_COLOR_MASK_ALPHA + + interlace_type - (PNG_INTERLACE_NONE or + PNG_INTERLACE_ADAM7) + + compression_type - (must be PNG_COMPRESSION_TYPE_BASE + for PNG 1.0) + + filter_method - (must be PNG_FILTER_TYPE_BASE + for PNG 1.0, and can also be + PNG_INTRAPIXEL_DIFFERENCING if + the PNG datastream is embedded in + a MNG-1.0 datastream) + + Any of width, height, color_type, bit_depth, + interlace_type, compression_type, or filter_method can + be NULL if you are not interested in their values. + + Note that png_get_IHDR() returns 32-bit data into + the application's width and height variables. + This is an unsafe situation if these are not png_uint_32 + variables. In such situations, the + png_get_image_width() and png_get_image_height() + functions described below are safer. + + width = png_get_image_width(png_ptr, + info_ptr); + + height = png_get_image_height(png_ptr, + info_ptr); + + bit_depth = png_get_bit_depth(png_ptr, + info_ptr); + + color_type = png_get_color_type(png_ptr, + info_ptr); + + interlace_type = png_get_interlace_type(png_ptr, + info_ptr); + + compression_type = png_get_compression_type(png_ptr, + info_ptr); + + filter_method = png_get_filter_type(png_ptr, + info_ptr); + + channels = png_get_channels(png_ptr, info_ptr); + + channels - number of channels of info for the + color type (valid values are 1 (GRAY, + PALETTE), 2 (GRAY_ALPHA), 3 (RGB), + 4 (RGB_ALPHA or RGB + filler byte)) + + rowbytes = png_get_rowbytes(png_ptr, info_ptr); + + rowbytes - number of bytes needed to hold a row + This value, the bit_depth, color_type, + and the number of channels can change + if you use transforms such as + png_set_expand(). See + png_read_update_info(), below. + + signature = png_get_signature(png_ptr, info_ptr); + + signature - holds the signature read from the + file (if any). The data is kept in + the same offset it would be if the + whole signature were read (i.e. if an + application had already read in 4 + bytes of signature before starting + libpng, the remaining 4 bytes would + be in signature[4] through signature[7] + (see png_set_sig_bytes())). + +These are also important, but their validity depends on whether the chunk +has been read. The png_get_valid(png_ptr, info_ptr, PNG_INFO_<chunk>) and +png_get_<chunk>(png_ptr, info_ptr, ...) functions return non-zero if the +data has been read, or zero if it is missing. The parameters to the +png_get_<chunk> are set directly if they are simple data types, or a +pointer into the info_ptr is returned for any complex types. + +The colorspace data from gAMA, cHRM, sRGB, iCCP, and sBIT chunks +is simply returned to give the application information about how the +image was encoded. Libpng itself only does transformations using the file +gamma when combining semitransparent pixels with the background color, and, +since libpng-1.6.0, when converting between 8-bit sRGB and 16-bit linear pixels +within the simplified API. Libpng also uses the file gamma when converting +RGB to gray, beginning with libpng-1.0.5, if the application calls +png_set_rgb_to_gray()). + + png_get_PLTE(png_ptr, info_ptr, &palette, + &num_palette); + + palette - the palette for the file + (array of png_color) + + num_palette - number of entries in the palette + + png_get_gAMA(png_ptr, info_ptr, &file_gamma); + png_get_gAMA_fixed(png_ptr, info_ptr, &int_file_gamma); + + file_gamma - the gamma at which the file is + written (PNG_INFO_gAMA) + + int_file_gamma - 100,000 times the gamma at which the + file is written + + png_get_cHRM(png_ptr, info_ptr, &white_x, &white_y, &red_x, + &red_y, &green_x, &green_y, &blue_x, &blue_y) + png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z, + &green_X, &green_Y, &green_Z, &blue_X, &blue_Y, + &blue_Z) + png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x, + &int_white_y, &int_red_x, &int_red_y, + &int_green_x, &int_green_y, &int_blue_x, + &int_blue_y) + png_get_cHRM_XYZ_fixed(png_ptr, info_ptr, &int_red_X, &int_red_Y, + &int_red_Z, &int_green_X, &int_green_Y, + &int_green_Z, &int_blue_X, &int_blue_Y, + &int_blue_Z) + + {white,red,green,blue}_{x,y} + A color space encoding specified using the + chromaticities of the end points and the + white point. (PNG_INFO_cHRM) + + {red,green,blue}_{X,Y,Z} + A color space encoding specified using the + encoding end points - the CIE tristimulus + specification of the intended color of the red, + green and blue channels in the PNG RGB data. + The white point is simply the sum of the three + end points. (PNG_INFO_cHRM) + + png_get_sRGB(png_ptr, info_ptr, &srgb_intent); + + srgb_intent - the rendering intent (PNG_INFO_sRGB) + The presence of the sRGB chunk + means that the pixel data is in the + sRGB color space. This chunk also + implies specific values of gAMA and + cHRM. + + png_get_iCCP(png_ptr, info_ptr, &name, + &compression_type, &profile, &proflen); + + name - The profile name. + + compression_type - The compression type; always + PNG_COMPRESSION_TYPE_BASE for PNG 1.0. + You may give NULL to this argument to + ignore it. + + profile - International Color Consortium color + profile data. May contain NULs. + + proflen - length of profile data in bytes. + + png_get_sBIT(png_ptr, info_ptr, &sig_bit); + + sig_bit - the number of significant bits for + (PNG_INFO_sBIT) each of the gray, + red, green, and blue channels, + whichever are appropriate for the + given color type (png_color_16) + + png_get_tRNS(png_ptr, info_ptr, &trans_alpha, + &num_trans, &trans_color); + + trans_alpha - array of alpha (transparency) + entries for palette (PNG_INFO_tRNS) + + num_trans - number of transparent entries + (PNG_INFO_tRNS) + + trans_color - graylevel or color sample values of + the single transparent color for + non-paletted images (PNG_INFO_tRNS) + + png_get_eXIf_1(png_ptr, info_ptr, &num_exif, &exif); + (PNG_INFO_eXIf) + + exif - Exif profile (array of png_byte) + + png_get_hIST(png_ptr, info_ptr, &hist); + (PNG_INFO_hIST) + + hist - histogram of palette (array of + png_uint_16) + + png_get_tIME(png_ptr, info_ptr, &mod_time); + + mod_time - time image was last modified + (PNG_VALID_tIME) + + png_get_bKGD(png_ptr, info_ptr, &background); + + background - background color (of type + png_color_16p) (PNG_VALID_bKGD) + valid 16-bit red, green and blue + values, regardless of color_type + + num_comments = png_get_text(png_ptr, info_ptr, + &text_ptr, &num_text); + + num_comments - number of comments + + text_ptr - array of png_text holding image + comments + + text_ptr[i].compression - type of compression used + on "text" PNG_TEXT_COMPRESSION_NONE + PNG_TEXT_COMPRESSION_zTXt + PNG_ITXT_COMPRESSION_NONE + PNG_ITXT_COMPRESSION_zTXt + + text_ptr[i].key - keyword for comment. Must contain + 1-79 characters. + + text_ptr[i].text - text comments for current + keyword. Can be empty. + + text_ptr[i].text_length - length of text string, + after decompression, 0 for iTXt + + text_ptr[i].itxt_length - length of itxt string, + after decompression, 0 for tEXt/zTXt + + text_ptr[i].lang - language of comment (empty + string for unknown). + + text_ptr[i].lang_key - keyword in UTF-8 + (empty string for unknown). + + Note that the itxt_length, lang, and lang_key + members of the text_ptr structure only exist when the + library is built with iTXt chunk support. Prior to + libpng-1.4.0 the library was built by default without + iTXt support. Also note that when iTXt is supported, + they contain NULL pointers when the "compression" + field contains PNG_TEXT_COMPRESSION_NONE or + PNG_TEXT_COMPRESSION_zTXt. + + num_text - number of comments (same as + num_comments; you can put NULL here + to avoid the duplication) + + Note while png_set_text() will accept text, language, + and translated keywords that can be NULL pointers, the + structure returned by png_get_text will always contain + regular zero-terminated C strings. They might be + empty strings but they will never be NULL pointers. + + num_spalettes = png_get_sPLT(png_ptr, info_ptr, + &palette_ptr); + + num_spalettes - number of sPLT chunks read. + + palette_ptr - array of palette structures holding + contents of one or more sPLT chunks + read. + + png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y, + &unit_type); + + offset_x - positive offset from the left edge + of the screen (can be negative) + + offset_y - positive offset from the top edge + of the screen (can be negative) + + unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER + + png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y, + &unit_type); + + res_x - pixels/unit physical resolution in + x direction + + res_y - pixels/unit physical resolution in + x direction + + unit_type - PNG_RESOLUTION_UNKNOWN, + PNG_RESOLUTION_METER + + png_get_sCAL(png_ptr, info_ptr, &unit, &width, + &height) + + unit - physical scale units (an integer) + + width - width of a pixel in physical scale units + + height - height of a pixel in physical scale units + (width and height are doubles) + + png_get_sCAL_s(png_ptr, info_ptr, &unit, &width, + &height) + + unit - physical scale units (an integer) + + width - width of a pixel in physical scale units + (expressed as a string) + + height - height of a pixel in physical scale units + (width and height are strings like "2.54") + + num_unknown_chunks = png_get_unknown_chunks(png_ptr, + info_ptr, &unknowns) + + unknowns - array of png_unknown_chunk + structures holding unknown chunks + + unknowns[i].name - name of unknown chunk + + unknowns[i].data - data of unknown chunk + + unknowns[i].size - size of unknown chunk's data + + unknowns[i].location - position of chunk in file + + The value of "i" corresponds to the order in which the + chunks were read from the PNG file or inserted with the + png_set_unknown_chunks() function. + + The value of "location" is a bitwise "or" of + + PNG_HAVE_IHDR (0x01) + PNG_HAVE_PLTE (0x02) + PNG_AFTER_IDAT (0x08) + +The data from the pHYs chunk can be retrieved in several convenient +forms: + + res_x = png_get_x_pixels_per_meter(png_ptr, + info_ptr) + + res_y = png_get_y_pixels_per_meter(png_ptr, + info_ptr) + + res_x_and_y = png_get_pixels_per_meter(png_ptr, + info_ptr) + + res_x = png_get_x_pixels_per_inch(png_ptr, + info_ptr) + + res_y = png_get_y_pixels_per_inch(png_ptr, + info_ptr) + + res_x_and_y = png_get_pixels_per_inch(png_ptr, + info_ptr) + + aspect_ratio = png_get_pixel_aspect_ratio(png_ptr, + info_ptr) + + Each of these returns 0 [signifying "unknown"] if + the data is not present or if res_x is 0; + res_x_and_y is 0 if res_x != res_y + + Note that because of the way the resolutions are + stored internally, the inch conversions won't + come out to exactly even number. For example, + 72 dpi is stored as 0.28346 pixels/meter, and + when this is retrieved it is 71.9988 dpi, so + be sure to round the returned value appropriately + if you want to display a reasonable-looking result. + +The data from the oFFs chunk can be retrieved in several convenient +forms: + + x_offset = png_get_x_offset_microns(png_ptr, info_ptr); + + y_offset = png_get_y_offset_microns(png_ptr, info_ptr); + + x_offset = png_get_x_offset_inches(png_ptr, info_ptr); + + y_offset = png_get_y_offset_inches(png_ptr, info_ptr); + + Each of these returns 0 [signifying "unknown" if both + x and y are 0] if the data is not present or if the + chunk is present but the unit is the pixel. The + remark about inexact inch conversions applies here + as well, because a value in inches can't always be + converted to microns and back without some loss + of precision. + +For more information, see the +PNG specification for chunk contents. Be careful with trusting +rowbytes, as some of the transformations could increase the space +needed to hold a row (expand, filler, gray_to_rgb, etc.). +See png_read_update_info(), below. + +A quick word about text_ptr and num_text. PNG stores comments in +keyword/text pairs, one pair per chunk, with no limit on the number +of text chunks, and a 2^31 byte limit on their size. While there are +suggested keywords, there is no requirement to restrict the use to these +strings. It is strongly suggested that keywords and text be sensible +to humans (that's the point), so don't use abbreviations. Non-printing +symbols are not allowed. See the PNG specification for more details. +There is also no requirement to have text after the keyword. + +Keywords should be limited to 79 Latin-1 characters without leading or +trailing spaces, but non-consecutive spaces are allowed within the +keyword. It is possible to have the same keyword any number of times. +The text_ptr is an array of png_text structures, each holding a +pointer to a language string, a pointer to a keyword and a pointer to +a text string. The text string, language code, and translated +keyword may be empty or NULL pointers. The keyword/text +pairs are put into the array in the order that they are received. +However, some or all of the text chunks may be after the image, so, to +make sure you have read all the text chunks, don't mess with these +until after you read the stuff after the image. This will be +mentioned again below in the discussion that goes with png_read_end(). + +Input transformations + +After you've read the header information, you can set up the library +to handle any special transformations of the image data. The various +ways to transform the data will be described in the order that they +should occur. This is important, as some of these change the color +type and/or bit depth of the data, and some others only work on +certain color types and bit depths. + +Transformations you request are ignored if they don't have any meaning for a +particular input data format. However some transformations can have an effect +as a result of a previous transformation. If you specify a contradictory set of +transformations, for example both adding and removing the alpha channel, you +cannot predict the final result. + +The color used for the transparency values should be supplied in the same +format/depth as the current image data. It is stored in the same format/depth +as the image data in a tRNS chunk, so this is what libpng expects for this data. + +The color used for the background value depends on the need_expand argument as +described below. + +Data will be decoded into the supplied row buffers packed into bytes +unless the library has been told to transform it into another format. +For example, 4 bit/pixel paletted or grayscale data will be returned +2 pixels/byte with the leftmost pixel in the high-order bits of the byte, +unless png_set_packing() is called. 8-bit RGB data will be stored +in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha() +is called to insert filler bytes, either before or after each RGB triplet. + +16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant +byte of the color value first, unless png_set_scale_16() is called to +transform it to regular RGB RGB triplets, or png_set_filler() or +png_set_add alpha() is called to insert two filler bytes, either before +or after each RRGGBB triplet. Similarly, 8-bit or 16-bit grayscale data can +be modified with png_set_filler(), png_set_add_alpha(), png_set_strip_16(), +or png_set_scale_16(). + +The following code transforms grayscale images of less than 8 to 8 bits, +changes paletted images to RGB, and adds a full alpha channel if there is +transparency information in a tRNS chunk. This is most useful on +grayscale images with bit depths of 2 or 4 or if there is a multiple-image +viewing application that wishes to treat all images in the same way. + + if (color_type == PNG_COLOR_TYPE_PALETTE) + png_set_palette_to_rgb(png_ptr); + + if (png_get_valid(png_ptr, info_ptr, + PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr); + + if (color_type == PNG_COLOR_TYPE_GRAY && + bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr); + +The first two functions are actually aliases for png_set_expand(), added +in libpng version 1.0.4, with the function names expanded to improve code +readability. In some future version they may actually do different +things. + +As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was +added. It expands the sample depth without changing tRNS to alpha. + +As of libpng version 1.5.2, png_set_expand_16() was added. It behaves as +png_set_expand(); however, the resultant channels have 16 bits rather than 8. +Use this when the output color or gray channels are made linear to avoid fairly +severe accuracy loss. + + if (bit_depth < 16) + png_set_expand_16(png_ptr); + +PNG can have files with 16 bits per channel. If you only can handle +8 bits per channel, this will strip the pixels down to 8-bit. + + if (bit_depth == 16) +#if PNG_LIBPNG_VER >= 10504 + png_set_scale_16(png_ptr); +#else + png_set_strip_16(png_ptr); +#endif + +(The more accurate "png_set_scale_16()" API became available in libpng version +1.5.4). + +If you need to process the alpha channel on the image separately from the image +data (for example if you convert it to a bitmap mask) it is possible to have +libpng strip the channel leaving just RGB or gray data: + + if (color_type & PNG_COLOR_MASK_ALPHA) + png_set_strip_alpha(png_ptr); + +If you strip the alpha channel you need to find some other way of dealing with +the information. If, instead, you want to convert the image to an opaque +version with no alpha channel use png_set_background; see below. + +As of libpng version 1.5.2, almost all useful expansions are supported, the +major ommissions are conversion of grayscale to indexed images (which can be +done trivially in the application) and conversion of indexed to grayscale (which +can be done by a trivial manipulation of the palette.) + +In the following table, the 01 means grayscale with depth<8, 31 means +indexed with depth<8, other numerals represent the color type, "T" means +the tRNS chunk is present, A means an alpha channel is present, and O +means tRNS or alpha is present but all pixels in the image are opaque. + + FROM 01 31 0 0T 0O 2 2T 2O 3 3T 3O 4A 4O 6A 6O + TO + 01 - [G] - - - - - - - - - - - - - + 31 [Q] Q [Q] [Q] [Q] Q Q Q Q Q Q [Q] [Q] Q Q + 0 1 G + . . G G G G G G B B GB GB + 0T lt Gt t + . Gt G G Gt G G Bt Bt GBt GBt + 0O lt Gt t . + Gt Gt G Gt Gt G Bt Bt GBt GBt + 2 C P C C C + . . C - - CB CB B B + 2T Ct - Ct C C t + t - - - CBt CBt Bt Bt + 2O Ct - Ct C C t t + - - - CBt CBt Bt Bt + 3 [Q] p [Q] [Q] [Q] Q Q Q + . . [Q] [Q] Q Q + 3T [Qt] p [Qt][Q] [Q] Qt Qt Qt t + t [Qt][Qt] Qt Qt + 3O [Qt] p [Qt][Q] [Q] Qt Qt Qt t t + [Qt][Qt] Qt Qt + 4A lA G A T T GA GT GT GA GT GT + BA G GBA + 4O lA GBA A T T GA GT GT GA GT GT BA + GBA G + 6A CA PA CA C C A T tT PA P P C CBA + BA + 6O CA PBA CA C C A tT T PA P P CBA C BA + + +Within the matrix, + "+" identifies entries where 'from' and 'to' are the same. + "-" means the transformation is not supported. + "." means nothing is necessary (a tRNS chunk can just be ignored). + "t" means the transformation is obtained by png_set_tRNS. + "A" means the transformation is obtained by png_set_add_alpha(). + "X" means the transformation is obtained by png_set_expand(). + "1" means the transformation is obtained by + png_set_expand_gray_1_2_4_to_8() (and by png_set_expand() + if there is no transparency in the original or the final + format). + "C" means the transformation is obtained by png_set_gray_to_rgb(). + "G" means the transformation is obtained by png_set_rgb_to_gray(). + "P" means the transformation is obtained by + png_set_expand_palette_to_rgb(). + "p" means the transformation is obtained by png_set_packing(). + "Q" means the transformation is obtained by png_set_quantize(). + "T" means the transformation is obtained by + png_set_tRNS_to_alpha(). + "B" means the transformation is obtained by + png_set_background(), or png_strip_alpha(). + +When an entry has multiple transforms listed all are required to cause the +right overall transformation. When two transforms are separated by a comma +either will do the job. When transforms are enclosed in [] the transform should +do the job but this is currently unimplemented - a different format will result +if the suggested transformations are used. + +In PNG files, the alpha channel in an image +is the level of opacity. If you need the alpha channel in an image to +be the level of transparency instead of opacity, you can invert the +alpha channel (or the tRNS chunk data) after it's read, so that 0 is +fully opaque and 255 (in 8-bit or paletted images) or 65535 (in 16-bit +images) is fully transparent, with + + png_set_invert_alpha(png_ptr); + +PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as +they can, resulting in, for example, 8 pixels per byte for 1 bit +files. This code expands to 1 pixel per byte without changing the +values of the pixels: + + if (bit_depth < 8) + png_set_packing(png_ptr); + +PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels +stored in a PNG image have been "scaled" or "shifted" up to the next +higher possible bit depth (e.g. from 5 bits/sample in the range [0,31] +to 8 bits/sample in the range [0, 255]). However, it is also possible +to convert the PNG pixel data back to the original bit depth of the +image. This call reduces the pixels back down to the original bit depth: + + png_color_8p sig_bit; + + if (png_get_sBIT(png_ptr, info_ptr, &sig_bit)) + png_set_shift(png_ptr, sig_bit); + +PNG files store 3-color pixels in red, green, blue order. This code +changes the storage of the pixels to blue, green, red: + + if (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_bgr(png_ptr); + +PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them +into 4 or 8 bytes for windowing systems that need them in this format: + + if (color_type == PNG_COLOR_TYPE_RGB) + png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE); + +where "filler" is the 8-bit or 16-bit number to fill with, and the location +is either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether +you want the filler before the RGB or after. When filling an 8-bit pixel, +the least significant 8 bits of the number are used, if a 16-bit number is +supplied. This transformation does not affect images that already have full +alpha channels. To add an opaque alpha channel, use filler=0xffff and +PNG_FILLER_AFTER which will generate RGBA pixels. + +Note that png_set_filler() does not change the color type. If you want +to do that, you can add a true alpha channel with + + if (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_GRAY) + png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER); + +where "filler" contains the alpha value to assign to each pixel. +The png_set_add_alpha() function was added in libpng-1.2.7. + +If you are reading an image with an alpha channel, and you need the +data as ARGB instead of the normal PNG format RGBA: + + if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_swap_alpha(png_ptr); + +For some uses, you may want a grayscale image to be represented as +RGB. This code will do that conversion: + + if (color_type == PNG_COLOR_TYPE_GRAY || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_gray_to_rgb(png_ptr); + +Conversely, you can convert an RGB or RGBA image to grayscale or grayscale +with alpha. + + if (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_rgb_to_gray(png_ptr, error_action, + double red_weight, double green_weight); + + error_action = 1: silently do the conversion + + error_action = 2: issue a warning if the original + image has any pixel where + red != green or red != blue + + error_action = 3: issue an error and abort the + conversion if the original + image has any pixel where + red != green or red != blue + + red_weight: weight of red component + + green_weight: weight of green component + If either weight is negative, default + weights are used. + +In the corresponding fixed point API the red_weight and green_weight values are +simply scaled by 100,000: + + png_set_rgb_to_gray(png_ptr, error_action, + png_fixed_point red_weight, + png_fixed_point green_weight); + +If you have set error_action = 1 or 2, you can +later check whether the image really was gray, after processing +the image rows, with the png_get_rgb_to_gray_status(png_ptr) function. +It will return a png_byte that is zero if the image was gray or +1 if there were any non-gray pixels. Background and sBIT data +will be silently converted to grayscale, using the green channel +data for sBIT, regardless of the error_action setting. + +The default values come from the PNG file cHRM chunk if present; otherwise, the +defaults correspond to the ITU-R recommendation 709, and also the sRGB color +space, as recommended in the Charles Poynton's Colour FAQ, +Copyright (c) 2006-11-28 Charles Poynton, in section 9: + +<http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html#RTFToC9> + + Y = 0.2126 * R + 0.7152 * G + 0.0722 * B + +Previous versions of this document, 1998 through 2002, recommended a slightly +different formula: + + Y = 0.212671 * R + 0.715160 * G + 0.072169 * B + +Libpng uses an integer approximation: + + Y = (6968 * R + 23434 * G + 2366 * B)/32768 + +The calculation is done in a linear colorspace, if the image gamma +can be determined. + +The png_set_background() function has been described already; it tells libpng to +composite images with alpha or simple transparency against the supplied +background color. For compatibility with versions of libpng earlier than +libpng-1.5.4 it is recommended that you call the function after reading the file +header, even if you don't want to use the color in a bKGD chunk, if one exists. + +If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid), +you may use this color, or supply another color more suitable for +the current display (e.g., the background color from a web page). You +need to tell libpng how the color is represented, both the format of the +component values in the color (the number of bits) and the gamma encoding of the +color. The function takes two arguments, background_gamma_mode and need_expand +to convey this information; however, only two combinations are likely to be +useful: + + png_color_16 my_background; + png_color_16p image_background; + + if (png_get_bKGD(png_ptr, info_ptr, &image_background)) + png_set_background(png_ptr, image_background, + PNG_BACKGROUND_GAMMA_FILE, 1/*needs to be expanded*/, 1); + else + png_set_background(png_ptr, &my_background, + PNG_BACKGROUND_GAMMA_SCREEN, 0/*do not expand*/, 1); + +The second call was described above - my_background is in the format of the +final, display, output produced by libpng. Because you now know the format of +the PNG it is possible to avoid the need to choose either 8-bit or 16-bit +output and to retain palette images (the palette colors will be modified +appropriately and the tRNS chunk removed.) However, if you are doing this, +take great care not to ask for transformations without checking first that +they apply! + +In the first call the background color has the original bit depth and color type +of the PNG file. So, for palette images the color is supplied as a palette +index and for low bit greyscale images the color is a reduced bit value in +image_background->gray. + +If you didn't call png_set_gamma() before reading the file header, for example +if you need your code to remain compatible with older versions of libpng prior +to libpng-1.5.4, this is the place to call it. + +Do not call it if you called png_set_alpha_mode(); doing so will damage the +settings put in place by png_set_alpha_mode(). (If png_set_alpha_mode() is +supported then you can certainly do png_set_gamma() before reading the PNG +header.) + +This API unconditionally sets the screen and file gamma values, so it will +override the value in the PNG file unless it is called before the PNG file +reading starts. For this reason you must always call it with the PNG file +value when you call it in this position: + + if (png_get_gAMA(png_ptr, info_ptr, &file_gamma)) + png_set_gamma(png_ptr, screen_gamma, file_gamma); + + else + png_set_gamma(png_ptr, screen_gamma, 0.45455); + +If you need to reduce an RGB file to a paletted file, or if a paletted +file has more entries than will fit on your screen, png_set_quantize() +will do that. Note that this is a simple match quantization that merely +finds the closest color available. This should work fairly well with +optimized palettes, but fairly badly with linear color cubes. If you +pass a palette that is larger than maximum_colors, the file will +reduce the number of colors in the palette so it will fit into +maximum_colors. If there is a histogram, libpng will use it to make +more intelligent choices when reducing the palette. If there is no +histogram, it may not do as good a job. + + if (color_type & PNG_COLOR_MASK_COLOR) + { + if (png_get_valid(png_ptr, info_ptr, + PNG_INFO_PLTE)) + { + png_uint_16p histogram = NULL; + + png_get_hIST(png_ptr, info_ptr, + &histogram); + png_set_quantize(png_ptr, palette, num_palette, + max_screen_colors, histogram, 1); + } + + else + { + png_color std_color_cube[MAX_SCREEN_COLORS] = + { ... colors ... }; + + png_set_quantize(png_ptr, std_color_cube, + MAX_SCREEN_COLORS, MAX_SCREEN_COLORS, + NULL,0); + } + } + +PNG files describe monochrome as black being zero and white being one. +The following code will reverse this (make black be one and white be +zero): + + if (bit_depth == 1 && color_type == PNG_COLOR_TYPE_GRAY) + png_set_invert_mono(png_ptr); + +This function can also be used to invert grayscale and gray-alpha images: + + if (color_type == PNG_COLOR_TYPE_GRAY || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_invert_mono(png_ptr); + +PNG files store 16-bit pixels in network byte order (big-endian, +ie. most significant bits first). This code changes the storage to the +other way (little-endian, i.e. least significant bits first, the +way PCs store them): + + if (bit_depth == 16) + png_set_swap(png_ptr); + +If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you +need to change the order the pixels are packed into bytes, you can use: + + if (bit_depth < 8) + png_set_packswap(png_ptr); + +Finally, you can write your own transformation function if none of +the existing ones meets your needs. This is done by setting a callback +with + + png_set_read_user_transform_fn(png_ptr, + read_transform_fn); + +You must supply the function + + void read_transform_fn(png_structp png_ptr, png_row_infop + row_info, png_bytep data) + +See pngtest.c for a working example. Your function will be called +after all of the other transformations have been processed. Take care with +interlaced images if you do the interlace yourself - the width of the row is the +width in 'row_info', not the overall image width. + +If supported, libpng provides two information routines that you can use to find +where you are in processing the image: + + png_get_current_pass_number(png_structp png_ptr); + png_get_current_row_number(png_structp png_ptr); + +Don't try using these outside a transform callback - firstly they are only +supported if user transforms are supported, secondly they may well return +unexpected results unless the row is actually being processed at the moment they +are called. + +With interlaced +images the value returned is the row in the input sub-image image. Use +PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to +find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass). + +The discussion of interlace handling above contains more information on how to +use these values. + +You can also set up a pointer to a user structure for use by your +callback function, and you can inform libpng that your transform +function will change the number of channels or bit depth with the +function + + png_set_user_transform_info(png_ptr, user_ptr, + user_depth, user_channels); + +The user's application, not libpng, is responsible for allocating and +freeing any memory required for the user structure. + +You can retrieve the pointer via the function +png_get_user_transform_ptr(). For example: + + voidp read_user_transform_ptr = + png_get_user_transform_ptr(png_ptr); + +The last thing to handle is interlacing; this is covered in detail below, +but you must call the function here if you want libpng to handle expansion +of the interlaced image. + + number_of_passes = png_set_interlace_handling(png_ptr); + +After setting the transformations, libpng can update your png_info +structure to reflect any transformations you've requested with this +call. + + png_read_update_info(png_ptr, info_ptr); + +This is most useful to update the info structure's rowbytes +field so you can use it to allocate your image memory. This function +will also update your palette with the correct screen_gamma and +background if these have been given with the calls above. You may +only call png_read_update_info() once with a particular info_ptr. + +After you call png_read_update_info(), you can allocate any +memory you need to hold the image. The row data is simply +raw byte data for all forms of images. As the actual allocation +varies among applications, no example will be given. If you +are allocating one large chunk, you will need to build an +array of pointers to each row, as it will be needed for some +of the functions below. + +Be sure that your platform can allocate the buffer that you'll need. +libpng internally checks for oversize width, but you'll need to +do your own check for number_of_rows*width*pixel_size if you are using +a multiple-row buffer: + + /* Guard against integer overflow */ + if (number_of_rows > PNG_SIZE_MAX/(width*pixel_size)) { + png_error(png_ptr,"image_data buffer would be too large"); + } + +Remember: Before you call png_read_update_info(), the png_get_*() +functions return the values corresponding to the original PNG image. +After you call png_read_update_info the values refer to the image +that libpng will output. Consequently you must call all the png_set_ +functions before you call png_read_update_info(). This is particularly +important for png_set_interlace_handling() - if you are going to call +png_read_update_info() you must call png_set_interlace_handling() before +it unless you want to receive interlaced output. + +Reading image data + +After you've allocated memory, you can read the image data. +The simplest way to do this is in one function call. If you are +allocating enough memory to hold the whole image, you can just +call png_read_image() and libpng will read in all the image data +and put it in the memory area supplied. You will need to pass in +an array of pointers to each row. + +This function automatically handles interlacing, so you don't +need to call png_set_interlace_handling() (unless you call +png_read_update_info()) or call this function multiple times, or any +of that other stuff necessary with png_read_rows(). + + png_read_image(png_ptr, row_pointers); + +where row_pointers is: + + png_bytep row_pointers[height]; + +You can point to void or char or whatever you use for pixels. + +If you don't want to read in the whole image at once, you can +use png_read_rows() instead. If there is no interlacing (check +interlace_type == PNG_INTERLACE_NONE), this is simple: + + png_read_rows(png_ptr, row_pointers, NULL, + number_of_rows); + +where row_pointers is the same as in the png_read_image() call. + +If you are doing this just one row at a time, you can do this with +a single row_pointer instead of an array of row_pointers: + + png_bytep row_pointer = row; + png_read_row(png_ptr, row_pointer, NULL); + +If the file is interlaced (interlace_type != 0 in the IHDR chunk), things +get somewhat harder. The only current (PNG Specification version 1.2) +interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7); +a somewhat complicated 2D interlace scheme, known as Adam7, that +breaks down an image into seven smaller images of varying size, based +on an 8x8 grid. This number is defined (from libpng 1.5) as +PNG_INTERLACE_ADAM7_PASSES in png.h + +libpng can fill out those images or it can give them to you "as is". +It is almost always better to have libpng handle the interlacing for you. +If you want the images filled out, there are two ways to do that. The one +mentioned in the PNG specification is to expand each pixel to cover +those pixels that have not been read yet (the "rectangle" method). +This results in a blocky image for the first pass, which gradually +smooths out as more pixels are read. The other method is the "sparkle" +method, where pixels are drawn only in their final locations, with the +rest of the image remaining whatever colors they were initialized to +before the start of the read. The first method usually looks better, +but tends to be slower, as there are more pixels to put in the rows. + +If, as is likely, you want libpng to expand the images, call this before +calling png_start_read_image() or png_read_update_info(): + + if (interlace_type == PNG_INTERLACE_ADAM7) + number_of_passes + = png_set_interlace_handling(png_ptr); + +This will return the number of passes needed. Currently, this is seven, +but may change if another interlace type is added. This function can be +called even if the file is not interlaced, where it will return one pass. +You then need to read the whole image 'number_of_passes' times. Each time +will distribute the pixels from the current pass to the correct place in +the output image, so you need to supply the same rows to png_read_rows in +each pass. + +If you are not going to display the image after each pass, but are +going to wait until the entire image is read in, use the sparkle +effect. This effect is faster and the end result of either method +is exactly the same. If you are planning on displaying the image +after each pass, the "rectangle" effect is generally considered the +better looking one. + +If you only want the "sparkle" effect, just call png_read_row() or +png_read_rows() as +normal, with the third parameter NULL. Make sure you make pass over +the image number_of_passes times, and you don't change the data in the +rows between calls. You can change the locations of the data, just +not the data. Each pass only writes the pixels appropriate for that +pass, and assumes the data from previous passes is still valid. + + png_read_rows(png_ptr, row_pointers, NULL, + number_of_rows); + or + png_read_row(png_ptr, row_pointers, NULL); + +If you only want the first effect (the rectangles), do the same as +before except pass the row buffer in the third parameter, and leave +the second parameter NULL. + + png_read_rows(png_ptr, NULL, row_pointers, + number_of_rows); + or + png_read_row(png_ptr, NULL, row_pointers); + +If you don't want libpng to handle the interlacing details, just call +png_read_rows() PNG_INTERLACE_ADAM7_PASSES times to read in all the images. +Each of the images is a valid image by itself; however, you will almost +certainly need to distribute the pixels from each sub-image to the +correct place. This is where everything gets very tricky. + +If you want to retrieve the separate images you must pass the correct +number of rows to each successive call of png_read_rows(). The calculation +gets pretty complicated for small images, where some sub-images may +not even exist because either their width or height ends up zero. +libpng provides two macros to help you in 1.5 and later versions: + + png_uint_32 width = PNG_PASS_COLS(image_width, pass_number); + png_uint_32 height = PNG_PASS_ROWS(image_height, pass_number); + +Respectively these tell you the width and height of the sub-image +corresponding to the numbered pass. 'pass' is in in the range 0 to 6 - +this can be confusing because the specification refers to the same passes +as 1 to 7! Be careful, you must check both the width and height before +calling png_read_rows() and not call it for that pass if either is zero. + +You can, of course, read each sub-image row by row. If you want to +produce optimal code to make a pixel-by-pixel transformation of an +interlaced image this is the best approach; read each row of each pass, +transform it, and write it out to a new interlaced image. + +If you want to de-interlace the image yourself libpng provides further +macros to help that tell you where to place the pixels in the output image. +Because the interlacing scheme is rectangular - sub-image pixels are always +arranged on a rectangular grid - all you need to know for each pass is the +starting column and row in the output image of the first pixel plus the +spacing between each pixel. As of libpng 1.5 there are four macros to +retrieve this information: + + png_uint_32 x = PNG_PASS_START_COL(pass); + png_uint_32 y = PNG_PASS_START_ROW(pass); + png_uint_32 xStep = 1U << PNG_PASS_COL_SHIFT(pass); + png_uint_32 yStep = 1U << PNG_PASS_ROW_SHIFT(pass); + +These allow you to write the obvious loop: + + png_uint_32 input_y = 0; + png_uint_32 output_y = PNG_PASS_START_ROW(pass); + + while (output_y < output_image_height) + { + png_uint_32 input_x = 0; + png_uint_32 output_x = PNG_PASS_START_COL(pass); + + while (output_x < output_image_width) + { + image[output_y][output_x] = + subimage[pass][input_y][input_x++]; + + output_x += xStep; + } + + ++input_y; + output_y += yStep; + } + +Notice that the steps between successive output rows and columns are +returned as shifts. This is possible because the pixels in the subimages +are always a power of 2 apart - 1, 2, 4 or 8 pixels - in the original +image. In practice you may need to directly calculate the output coordinate +given an input coordinate. libpng provides two further macros for this +purpose: + + png_uint_32 output_x = PNG_COL_FROM_PASS_COL(input_x, pass); + png_uint_32 output_y = PNG_ROW_FROM_PASS_ROW(input_y, pass); + +Finally a pair of macros are provided to tell you if a particular image +row or column appears in a given pass: + + int col_in_pass = PNG_COL_IN_INTERLACE_PASS(output_x, pass); + int row_in_pass = PNG_ROW_IN_INTERLACE_PASS(output_y, pass); + +Bear in mind that you will probably also need to check the width and height +of the pass in addition to the above to be sure the pass even exists! + +With any luck you are convinced by now that you don't want to do your own +interlace handling. In reality normally the only good reason for doing this +is if you are processing PNG files on a pixel-by-pixel basis and don't want +to load the whole file into memory when it is interlaced. + +libpng includes a test program, pngvalid, that illustrates reading and +writing of interlaced images. If you can't get interlacing to work in your +code and don't want to leave it to libpng (the recommended approach), see +how pngvalid.c does it. + +Finishing a sequential read + +After you are finished reading the image through the +low-level interface, you can finish reading the file. + +If you want to use a different crc action for handling CRC errors in +chunks after the image data, you can call png_set_crc_action() +again at this point. + +If you are interested in comments or time, which may be stored either +before or after the image data, you should pass the separate png_info +struct if you want to keep the comments from before and after the image +separate. + + png_infop end_info = png_create_info_struct(png_ptr); + + if (!end_info) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return ERROR; + } + + png_read_end(png_ptr, end_info); + +If you are not interested, you should still call png_read_end() +but you can pass NULL, avoiding the need to create an end_info structure. +If you do this, libpng will not process any chunks after IDAT other than +skipping over them and perhaps (depending on whether you have called +png_set_crc_action) checking their CRCs while looking for the IEND chunk. + + png_read_end(png_ptr, (png_infop)NULL); + +If you don't call png_read_end(), then your file pointer will be +left pointing to the first chunk after the last IDAT, which is probably +not what you want if you expect to read something beyond the end of +the PNG datastream. + +When you are done, you can free all memory allocated by libpng like this: + + png_destroy_read_struct(&png_ptr, &info_ptr, + &end_info); + +or, if you didn't create an end_info structure, + + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + +It is also possible to individually free the info_ptr members that +point to libpng-allocated storage with the following function: + + png_free_data(png_ptr, info_ptr, mask, seq) + + mask - identifies data to be freed, a mask + containing the bitwise OR of one or + more of + PNG_FREE_PLTE, PNG_FREE_TRNS, + PNG_FREE_HIST, PNG_FREE_ICCP, + PNG_FREE_PCAL, PNG_FREE_ROWS, + PNG_FREE_SCAL, PNG_FREE_SPLT, + PNG_FREE_TEXT, PNG_FREE_UNKN, + or simply PNG_FREE_ALL + + seq - sequence number of item to be freed + (-1 for all items) + +This function may be safely called when the relevant storage has +already been freed, or has not yet been allocated, or was allocated +by the user and not by libpng, and will in those cases do nothing. +The "seq" parameter is ignored if only one item of the selected data +type, such as PLTE, is allowed. If "seq" is not -1, and multiple items +are allowed for the data type identified in the mask, such as text or +sPLT, only the n'th item in the structure is freed, where n is "seq". + +The default behavior is only to free data that was allocated internally +by libpng. This can be changed, so that libpng will not free the data, +or so that it will free data that was allocated by the user with png_malloc() +or png_calloc() and passed in via a png_set_*() function, with + + png_data_freer(png_ptr, info_ptr, freer, mask) + + freer - one of + PNG_DESTROY_WILL_FREE_DATA + PNG_SET_WILL_FREE_DATA + PNG_USER_WILL_FREE_DATA + + mask - which data elements are affected + same choices as in png_free_data() + +This function only affects data that has already been allocated. +You can call this function after reading the PNG data but before calling +any png_set_*() functions, to control whether the user or the png_set_*() +function is responsible for freeing any existing data that might be present, +and again after the png_set_*() functions to control whether the user +or png_destroy_*() is supposed to free the data. When the user assumes +responsibility for libpng-allocated data, the application must use +png_free() to free it, and when the user transfers responsibility to libpng +for data that the user has allocated, the user must have used png_malloc() +or png_calloc() to allocate it. + +If you allocated your row_pointers in a single block, as suggested above in +the description of the high level read interface, you must not transfer +responsibility for freeing it to the png_set_rows or png_read_destroy function, +because they would also try to free the individual row_pointers[i]. + +If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword +separately, do not transfer responsibility for freeing text_ptr to libpng, +because when libpng fills a png_text structure it combines these members with +the key member, and png_free_data() will free only text_ptr.key. Similarly, +if you transfer responsibility for free'ing text_ptr from libpng to your +application, your application must not separately free those members. + +The png_free_data() function will turn off the "valid" flag for anything +it frees. If you need to turn the flag off for a chunk that was freed by +your application instead of by libpng, you can use + + png_set_invalid(png_ptr, info_ptr, mask); + + mask - identifies the chunks to be made invalid, + containing the bitwise OR of one or + more of + PNG_INFO_gAMA, PNG_INFO_sBIT, + PNG_INFO_cHRM, PNG_INFO_PLTE, + PNG_INFO_tRNS, PNG_INFO_bKGD, + PNG_INFO_eXIf, + PNG_INFO_hIST, PNG_INFO_pHYs, + PNG_INFO_oFFs, PNG_INFO_tIME, + PNG_INFO_pCAL, PNG_INFO_sRGB, + PNG_INFO_iCCP, PNG_INFO_sPLT, + PNG_INFO_sCAL, PNG_INFO_IDAT + +For a more compact example of reading a PNG image, see the file example.c. + +Reading PNG files progressively + +The progressive reader is slightly different from the non-progressive +reader. Instead of calling png_read_info(), png_read_rows(), and +png_read_end(), you make one call to png_process_data(), which calls +callbacks when it has the info, a row, or the end of the image. You +set up these callbacks with png_set_progressive_read_fn(). You don't +have to worry about the input/output functions of libpng, as you are +giving the library the data directly in png_process_data(). I will +assume that you have read the section on reading PNG files above, +so I will only highlight the differences (although I will show +all of the code). + +png_structp png_ptr; +png_infop info_ptr; + + /* An example code fragment of how you would + initialize the progressive reader in your + application. */ + int + initialize_png_reader() + { + png_ptr = png_create_read_struct + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn); + + if (!png_ptr) + return ERROR; + + info_ptr = png_create_info_struct(png_ptr); + + if (!info_ptr) + { + png_destroy_read_struct(&png_ptr, + (png_infopp)NULL, (png_infopp)NULL); + return ERROR; + } + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return ERROR; + } + + /* This one's new. You can provide functions + to be called when the header info is valid, + when each row is completed, and when the image + is finished. If you aren't using all functions, + you can specify NULL parameters. Even when all + three functions are NULL, you need to call + png_set_progressive_read_fn(). You can use + any struct as the user_ptr (cast to a void pointer + for the function call), and retrieve the pointer + from inside the callbacks using the function + + png_get_progressive_ptr(png_ptr); + + which will return a void pointer, which you have + to cast appropriately. + */ + png_set_progressive_read_fn(png_ptr, (void *)user_ptr, + info_callback, row_callback, end_callback); + + return 0; + } + + /* A code fragment that you call as you receive blocks + of data */ + int + process_data(png_bytep buffer, png_uint_32 length) + { + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return ERROR; + } + + /* This one's new also. Simply give it a chunk + of data from the file stream (in order, of + course). On machines with segmented memory + models machines, don't give it any more than + 64K. The library seems to run fine with sizes + of 4K. Although you can give it much less if + necessary (I assume you can give it chunks of + 1 byte, I haven't tried less than 256 bytes + yet). When this function returns, you may + want to display any rows that were generated + in the row callback if you don't already do + so there. + */ + png_process_data(png_ptr, info_ptr, buffer, length); + + /* At this point you can call png_process_data_skip if + you want to handle data the library will skip yourself; + it simply returns the number of bytes to skip (and stops + libpng skipping that number of bytes on the next + png_process_data call). + return 0; + } + + /* This function is called (as set by + png_set_progressive_read_fn() above) when enough data + has been supplied so all of the header has been + read. + */ + void + info_callback(png_structp png_ptr, png_infop info) + { + /* Do any setup here, including setting any of + the transformations mentioned in the Reading + PNG files section. For now, you _must_ call + either png_start_read_image() or + png_read_update_info() after all the + transformations are set (even if you don't set + any). You may start getting rows before + png_process_data() returns, so this is your + last chance to prepare for that. + + This is where you turn on interlace handling, + assuming you don't want to do it yourself. + + If you need to you can stop the processing of + your original input data at this point by calling + png_process_data_pause. This returns the number + of unprocessed bytes from the last png_process_data + call - it is up to you to ensure that the next call + sees these bytes again. If you don't want to bother + with this you can get libpng to cache the unread + bytes by setting the 'save' parameter (see png.h) but + then libpng will have to copy the data internally. + */ + } + + /* This function is called when each row of image + data is complete */ + void + row_callback(png_structp png_ptr, png_bytep new_row, + png_uint_32 row_num, int pass) + { + /* If the image is interlaced, and you turned + on the interlace handler, this function will + be called for every row in every pass. Some + of these rows will not be changed from the + previous pass. When the row is not changed, + the new_row variable will be NULL. The rows + and passes are called in order, so you don't + really need the row_num and pass, but I'm + supplying them because it may make your life + easier. + + If you did not turn on interlace handling then + the callback is called for each row of each + sub-image when the image is interlaced. In this + case 'row_num' is the row in the sub-image, not + the row in the output image as it is in all other + cases. + + For the non-NULL rows of interlaced images when + you have switched on libpng interlace handling, + you must call png_progressive_combine_row() + passing in the row and the old row. You can + call this function for NULL rows (it will just + return) and for non-interlaced images (it just + does the memcpy for you) if it will make the + code easier. Thus, you can just do this for + all cases if you switch on interlace handling; + */ + + png_progressive_combine_row(png_ptr, old_row, + new_row); + + /* where old_row is what was displayed + previously for the row. Note that the first + pass (pass == 0, really) will completely cover + the old row, so the rows do not have to be + initialized. After the first pass (and only + for interlaced images), you will have to pass + the current row, and the function will combine + the old row and the new row. + + You can also call png_process_data_pause in this + callback - see above. + */ + } + + void + end_callback(png_structp png_ptr, png_infop info) + { + /* This function is called after the whole image + has been read, including any chunks after the + image (up to and including the IEND). You + will usually have the same info chunk as you + had in the header, although some data may have + been added to the comments and time fields. + + Most people won't do much here, perhaps setting + a flag that marks the image as finished. + */ + } + + + +IV. Writing + +Much of this is very similar to reading. However, everything of +importance is repeated here, so you won't have to constantly look +back up in the reading section to understand writing. + +Setup + +You will want to do the I/O initialization before you get into libpng, +so if it doesn't work, you don't have anything to undo. If you are not +using the standard I/O functions, you will need to replace them with +custom writing functions. See the discussion under Customizing libpng. + + FILE *fp = fopen(file_name, "wb"); + + if (!fp) + return ERROR; + +Next, png_struct and png_info need to be allocated and initialized. +As these can be both relatively large, you may not want to store these +on the stack, unless you have stack space to spare. Of course, you +will want to check if they return NULL. If you are also reading, +you won't want to name your read structure and your write structure +both "png_ptr"; you can call them anything you like, such as +"read_ptr" and "write_ptr". Look at pngtest.c, for example. + + png_structp png_ptr = png_create_write_struct + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn); + + if (!png_ptr) + return ERROR; + + png_infop info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) + { + png_destroy_write_struct(&png_ptr, + (png_infopp)NULL); + return ERROR; + } + +If you want to use your own memory allocation routines, +define PNG_USER_MEM_SUPPORTED and use +png_create_write_struct_2() instead of png_create_write_struct(): + + png_structp png_ptr = png_create_write_struct_2 + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn, (png_voidp) + user_mem_ptr, user_malloc_fn, user_free_fn); + +After you have these structures, you will need to set up the +error handling. When libpng encounters an error, it expects to +longjmp() back to your routine. Therefore, you will need to call +setjmp() and pass the png_jmpbuf(png_ptr). If you +write the file from different routines, you will need to update +the png_jmpbuf(png_ptr) every time you enter a new routine that will +call a png_*() function. See your documentation of setjmp/longjmp +for your compiler for more information on setjmp/longjmp. See +the discussion on libpng error handling in the Customizing Libpng +section below for more information on the libpng error handling. + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_write_struct(&png_ptr, &info_ptr); + fclose(fp); + return ERROR; + } + ... + return; + +If you would rather avoid the complexity of setjmp/longjmp issues, +you can compile libpng with PNG_NO_SETJMP, in which case +errors will result in a call to PNG_ABORT() which defaults to abort(). + +You can #define PNG_ABORT() to a function that does something +more useful than abort(), as long as your function does not +return. + +Checking for invalid palette index on write was added at libpng +1.5.10. If a pixel contains an invalid (out-of-range) index libpng issues +a benign error. This is enabled by default because this condition is an +error according to the PNG specification, Clause 11.3.2, but the error can +be ignored in each png_ptr with + + png_set_check_for_invalid_index(png_ptr, 0); + +If the error is ignored, or if png_benign_error() treats it as a warning, +any invalid pixels are written as-is by the encoder, resulting in an +invalid PNG datastream as output. In this case the application is +responsible for ensuring that the pixel indexes are in range when it writes +a PLTE chunk with fewer entries than the bit depth would allow. + +Now you need to set up the output code. The default for libpng is to +use the C function fwrite(). If you use this, you will need to pass a +valid FILE * in the function png_init_io(). Be sure that the file is +opened in binary mode. Again, if you wish to handle writing data in +another way, see the discussion on libpng I/O handling in the Customizing +Libpng section below. + + png_init_io(png_ptr, fp); + +If you are embedding your PNG into a datastream such as MNG, and don't +want libpng to write the 8-byte signature, or if you have already +written the signature in your application, use + + png_set_sig_bytes(png_ptr, 8); + +to inform libpng that it should not write a signature. + +Write callbacks + +At this point, you can set up a callback function that will be +called after each row has been written, which you can use to control +a progress meter or the like. It's demonstrated in pngtest.c. +You must supply a function + + void write_row_callback(png_structp png_ptr, png_uint_32 row, + int pass); + { + /* put your code here */ + } + +(You can give it another name that you like instead of "write_row_callback") + +To inform libpng about your function, use + + png_set_write_status_fn(png_ptr, write_row_callback); + +When this function is called the row has already been completely processed and +it has also been written out. The 'row' and 'pass' refer to the next row to be +handled. For the +non-interlaced case the row that was just handled is simply one less than the +passed in row number, and pass will always be 0. For the interlaced case the +same applies unless the row value is 0, in which case the row just handled was +the last one from one of the preceding passes. Because interlacing may skip a +pass you cannot be sure that the preceding pass is just 'pass-1', if you really +need to know what the last pass is record (row,pass) from the callback and use +the last recorded value each time. + +As with the user transform you can find the output row using the +PNG_ROW_FROM_PASS_ROW macro. + +You now have the option of modifying how the compression library will +run. The following functions are mainly for testing, but may be useful +in some cases, like if you need to write PNG files extremely fast and +are willing to give up some compression, or if you want to get the +maximum possible compression at the expense of slower writing. If you +have no special needs in this area, let the library do what it wants by +not calling this function at all, as it has been tuned to deliver a good +speed/compression ratio. The second parameter to png_set_filter() is +the filter method, for which the only valid values are 0 (as of the +July 1999 PNG specification, version 1.2) or 64 (if you are writing +a PNG datastream that is to be embedded in a MNG datastream). The third +parameter is a flag that indicates which filter type(s) are to be tested +for each scanline. See the PNG specification for details on the specific +filter types. + + + /* turn on or off filtering, and/or choose + specific filters. You can use either a single + PNG_FILTER_VALUE_NAME or the bitwise OR of one + or more PNG_FILTER_NAME masks. + */ + png_set_filter(png_ptr, 0, + PNG_FILTER_NONE | PNG_FILTER_VALUE_NONE | + PNG_FILTER_SUB | PNG_FILTER_VALUE_SUB | + PNG_FILTER_UP | PNG_FILTER_VALUE_UP | + PNG_FILTER_AVG | PNG_FILTER_VALUE_AVG | + PNG_FILTER_PAETH | PNG_FILTER_VALUE_PAETH| + PNG_ALL_FILTERS | PNG_FAST_FILTERS); + +If an application wants to start and stop using particular filters during +compression, it should start out with all of the filters (to ensure that +the previous row of pixels will be stored in case it's needed later), +and then add and remove them after the start of compression. + +If you are writing a PNG datastream that is to be embedded in a MNG +datastream, the second parameter can be either 0 or 64. + +The png_set_compression_*() functions interface to the zlib compression +library, and should mostly be ignored unless you really know what you are +doing. The only generally useful call is png_set_compression_level() +which changes how much time zlib spends on trying to compress the image +data. See the Compression Library (zlib.h and algorithm.txt, distributed +with zlib) for details on the compression levels. + + #include zlib.h + + /* Set the zlib compression level */ + png_set_compression_level(png_ptr, + Z_BEST_COMPRESSION); + + /* Set other zlib parameters for compressing IDAT */ + png_set_compression_mem_level(png_ptr, 8); + png_set_compression_strategy(png_ptr, + Z_DEFAULT_STRATEGY); + png_set_compression_window_bits(png_ptr, 15); + png_set_compression_method(png_ptr, 8); + png_set_compression_buffer_size(png_ptr, 8192) + + /* Set zlib parameters for text compression + * If you don't call these, the parameters + * fall back on those defined for IDAT chunks + */ + png_set_text_compression_mem_level(png_ptr, 8); + png_set_text_compression_strategy(png_ptr, + Z_DEFAULT_STRATEGY); + png_set_text_compression_window_bits(png_ptr, 15); + png_set_text_compression_method(png_ptr, 8); + +Setting the contents of info for output + +You now need to fill in the png_info structure with all the data you +wish to write before the actual image. Note that the only thing you +are allowed to write after the image is the text chunks and the time +chunk (as of PNG Specification 1.2, anyway). See png_write_end() and +the latest PNG specification for more information on that. If you +wish to write them before the image, fill them in now, and flag that +data as being valid. If you want to wait until after the data, don't +fill them until png_write_end(). For all the fields in png_info and +their data types, see png.h. For explanations of what the fields +contain, see the PNG specification. + +Some of the more important parts of the png_info are: + + png_set_IHDR(png_ptr, info_ptr, width, height, + bit_depth, color_type, interlace_type, + compression_type, filter_method) + + width - holds the width of the image + in pixels (up to 2^31). + + height - holds the height of the image + in pixels (up to 2^31). + + bit_depth - holds the bit depth of one of the + image channels. + (valid values are 1, 2, 4, 8, 16 + and depend also on the + color_type. See also significant + bits (sBIT) below). + + color_type - describes which color/alpha + channels are present. + PNG_COLOR_TYPE_GRAY + (bit depths 1, 2, 4, 8, 16) + PNG_COLOR_TYPE_GRAY_ALPHA + (bit depths 8, 16) + PNG_COLOR_TYPE_PALETTE + (bit depths 1, 2, 4, 8) + PNG_COLOR_TYPE_RGB + (bit_depths 8, 16) + PNG_COLOR_TYPE_RGB_ALPHA + (bit_depths 8, 16) + + PNG_COLOR_MASK_PALETTE + PNG_COLOR_MASK_COLOR + PNG_COLOR_MASK_ALPHA + + interlace_type - PNG_INTERLACE_NONE or + PNG_INTERLACE_ADAM7 + + compression_type - (must be + PNG_COMPRESSION_TYPE_DEFAULT) + + filter_method - (must be PNG_FILTER_TYPE_DEFAULT + or, if you are writing a PNG to + be embedded in a MNG datastream, + can also be + PNG_INTRAPIXEL_DIFFERENCING) + +If you call png_set_IHDR(), the call must appear before any of the +other png_set_*() functions, because they might require access to some of +the IHDR settings. The remaining png_set_*() functions can be called +in any order. + +If you wish, you can reset the compression_type, interlace_type, or +filter_method later by calling png_set_IHDR() again; if you do this, the +width, height, bit_depth, and color_type must be the same in each call. + + png_set_PLTE(png_ptr, info_ptr, palette, + num_palette); + + palette - the palette for the file + (array of png_color) + num_palette - number of entries in the palette + + + png_set_gAMA(png_ptr, info_ptr, file_gamma); + png_set_gAMA_fixed(png_ptr, info_ptr, int_file_gamma); + + file_gamma - the gamma at which the image was + created (PNG_INFO_gAMA) + + int_file_gamma - 100,000 times the gamma at which + the image was created + + png_set_cHRM(png_ptr, info_ptr, white_x, white_y, red_x, red_y, + green_x, green_y, blue_x, blue_y) + png_set_cHRM_XYZ(png_ptr, info_ptr, red_X, red_Y, red_Z, green_X, + green_Y, green_Z, blue_X, blue_Y, blue_Z) + png_set_cHRM_fixed(png_ptr, info_ptr, int_white_x, int_white_y, + int_red_x, int_red_y, int_green_x, int_green_y, + int_blue_x, int_blue_y) + png_set_cHRM_XYZ_fixed(png_ptr, info_ptr, int_red_X, int_red_Y, + int_red_Z, int_green_X, int_green_Y, int_green_Z, + int_blue_X, int_blue_Y, int_blue_Z) + + {white,red,green,blue}_{x,y} + A color space encoding specified using the chromaticities + of the end points and the white point. + + {red,green,blue}_{X,Y,Z} + A color space encoding specified using the encoding end + points - the CIE tristimulus specification of the intended + color of the red, green and blue channels in the PNG RGB + data. The white point is simply the sum of the three end + points. + + png_set_sRGB(png_ptr, info_ptr, srgb_intent); + + srgb_intent - the rendering intent + (PNG_INFO_sRGB) The presence of + the sRGB chunk means that the pixel + data is in the sRGB color space. + This chunk also implies specific + values of gAMA and cHRM. Rendering + intent is the CSS-1 property that + has been defined by the International + Color Consortium + (http://www.color.org). + It can be one of + PNG_sRGB_INTENT_SATURATION, + PNG_sRGB_INTENT_PERCEPTUAL, + PNG_sRGB_INTENT_ABSOLUTE, or + PNG_sRGB_INTENT_RELATIVE. + + + png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, + srgb_intent); + + srgb_intent - the rendering intent + (PNG_INFO_sRGB) The presence of the + sRGB chunk means that the pixel + data is in the sRGB color space. + This function also causes gAMA and + cHRM chunks with the specific values + that are consistent with sRGB to be + written. + + png_set_iCCP(png_ptr, info_ptr, name, compression_type, + profile, proflen); + + name - The profile name. + + compression_type - The compression type; always + PNG_COMPRESSION_TYPE_BASE for PNG 1.0. + You may give NULL to this argument to + ignore it. + + profile - International Color Consortium color + profile data. May contain NULs. + + proflen - length of profile data in bytes. + + png_set_sBIT(png_ptr, info_ptr, sig_bit); + + sig_bit - the number of significant bits for + (PNG_INFO_sBIT) each of the gray, red, + green, and blue channels, whichever are + appropriate for the given color type + (png_color_16) + + png_set_tRNS(png_ptr, info_ptr, trans_alpha, + num_trans, trans_color); + + trans_alpha - array of alpha (transparency) + entries for palette (PNG_INFO_tRNS) + + num_trans - number of transparent entries + (PNG_INFO_tRNS) + + trans_color - graylevel or color sample values + (in order red, green, blue) of the + single transparent color for + non-paletted images (PNG_INFO_tRNS) + + png_set_eXIf_1(png_ptr, info_ptr, num_exif, exif); + + exif - Exif profile (array of + png_byte) (PNG_INFO_eXIf) + + png_set_hIST(png_ptr, info_ptr, hist); + + hist - histogram of palette (array of + png_uint_16) (PNG_INFO_hIST) + + png_set_tIME(png_ptr, info_ptr, mod_time); + + mod_time - time image was last modified + (PNG_VALID_tIME) + + png_set_bKGD(png_ptr, info_ptr, background); + + background - background color (of type + png_color_16p) (PNG_VALID_bKGD) + + png_set_text(png_ptr, info_ptr, text_ptr, num_text); + + text_ptr - array of png_text holding image + comments + + text_ptr[i].compression - type of compression used + on "text" PNG_TEXT_COMPRESSION_NONE + PNG_TEXT_COMPRESSION_zTXt + PNG_ITXT_COMPRESSION_NONE + PNG_ITXT_COMPRESSION_zTXt + text_ptr[i].key - keyword for comment. Must contain + 1-79 characters. + text_ptr[i].text - text comments for current + keyword. Can be NULL or empty. + text_ptr[i].text_length - length of text string, + after decompression, 0 for iTXt + text_ptr[i].itxt_length - length of itxt string, + after decompression, 0 for tEXt/zTXt + text_ptr[i].lang - language of comment (NULL or + empty for unknown). + text_ptr[i].translated_keyword - keyword in UTF-8 (NULL + or empty for unknown). + + Note that the itxt_length, lang, and lang_key + members of the text_ptr structure only exist when the + library is built with iTXt chunk support. Prior to + libpng-1.4.0 the library was built by default without + iTXt support. Also note that when iTXt is supported, + they contain NULL pointers when the "compression" + field contains PNG_TEXT_COMPRESSION_NONE or + PNG_TEXT_COMPRESSION_zTXt. + + num_text - number of comments + + png_set_sPLT(png_ptr, info_ptr, &palette_ptr, + num_spalettes); + + palette_ptr - array of png_sPLT_struct structures + to be added to the list of palettes + in the info structure. + num_spalettes - number of palette structures to be + added. + + png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, + unit_type); + + offset_x - positive offset from the left + edge of the screen + + offset_y - positive offset from the top + edge of the screen + + unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER + + png_set_pHYs(png_ptr, info_ptr, res_x, res_y, + unit_type); + + res_x - pixels/unit physical resolution + in x direction + + res_y - pixels/unit physical resolution + in y direction + + unit_type - PNG_RESOLUTION_UNKNOWN, + PNG_RESOLUTION_METER + + png_set_sCAL(png_ptr, info_ptr, unit, width, height) + + unit - physical scale units (an integer) + + width - width of a pixel in physical scale units + + height - height of a pixel in physical scale units + (width and height are doubles) + + png_set_sCAL_s(png_ptr, info_ptr, unit, width, height) + + unit - physical scale units (an integer) + + width - width of a pixel in physical scale units + expressed as a string + + height - height of a pixel in physical scale units + (width and height are strings like "2.54") + + png_set_unknown_chunks(png_ptr, info_ptr, &unknowns, + num_unknowns) + + unknowns - array of png_unknown_chunk + structures holding unknown chunks + unknowns[i].name - name of unknown chunk + unknowns[i].data - data of unknown chunk + unknowns[i].size - size of unknown chunk's data + unknowns[i].location - position to write chunk in file + 0: do not write chunk + PNG_HAVE_IHDR: before PLTE + PNG_HAVE_PLTE: before IDAT + PNG_AFTER_IDAT: after IDAT + +The "location" member is set automatically according to +what part of the output file has already been written. +You can change its value after calling png_set_unknown_chunks() +as demonstrated in pngtest.c. Within each of the "locations", +the chunks are sequenced according to their position in the +structure (that is, the value of "i", which is the order in which +the chunk was either read from the input file or defined with +png_set_unknown_chunks). + +A quick word about text and num_text. text is an array of png_text +structures. num_text is the number of valid structures in the array. +Each png_text structure holds a language code, a keyword, a text value, +and a compression type. + +The compression types have the same valid numbers as the compression +types of the image data. Currently, the only valid number is zero. +However, you can store text either compressed or uncompressed, unlike +images, which always have to be compressed. So if you don't want the +text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE. +Because tEXt and zTXt chunks don't have a language field, if you +specify PNG_TEXT_COMPRESSION_NONE or PNG_TEXT_COMPRESSION_zTXt +any language code or translated keyword will not be written out. + +Until text gets around a few hundred bytes, it is not worth compressing it. +After the text has been written out to the file, the compression type +is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR, +so that it isn't written out again at the end (in case you are calling +png_write_end() with the same struct). + +The keywords that are given in the PNG Specification are: + + Title Short (one line) title or + caption for image + + Author Name of image's creator + + Description Description of image (possibly long) + + Copyright Copyright notice + + Creation Time Time of original image creation + (usually RFC 1123 format, see below) + + Software Software used to create the image + + Disclaimer Legal disclaimer + + Warning Warning of nature of content + + Source Device used to create the image + + Comment Miscellaneous comment; conversion + from other image format + +The keyword-text pairs work like this. Keywords should be short +simple descriptions of what the comment is about. Some typical +keywords are found in the PNG specification, as is some recommendations +on keywords. You can repeat keywords in a file. You can even write +some text before the image and some after. For example, you may want +to put a description of the image before the image, but leave the +disclaimer until after, so viewers working over modem connections +don't have to wait for the disclaimer to go over the modem before +they start seeing the image. Finally, keywords should be full +words, not abbreviations. Keywords and text are in the ISO 8859-1 +(Latin-1) character set (a superset of regular ASCII) and can not +contain NUL characters, and should not contain control or other +unprintable characters. To make the comments widely readable, stick +with basic ASCII, and avoid machine specific character set extensions +like the IBM-PC character set. The keyword must be present, but +you can leave off the text string on non-compressed pairs. +Compressed pairs must have a text string, as only the text string +is compressed anyway, so the compression would be meaningless. + +PNG supports modification time via the png_time structure. Two +conversion routines are provided, png_convert_from_time_t() for +time_t and png_convert_from_struct_tm() for struct tm. The +time_t routine uses gmtime(). You don't have to use either of +these, but if you wish to fill in the png_time structure directly, +you should provide the time in universal time (GMT) if possible +instead of your local time. Note that the year number is the full +year (e.g. 1998, rather than 98 - PNG is year 2000 compliant!), and +that months start with 1. + +If you want to store the time of the original image creation, you should +use a plain tEXt chunk with the "Creation Time" keyword. This is +necessary because the "creation time" of a PNG image is somewhat vague, +depending on whether you mean the PNG file, the time the image was +created in a non-PNG format, a still photo from which the image was +scanned, or possibly the subject matter itself. In order to facilitate +machine-readable dates, it is recommended that the "Creation Time" +tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"), +although this isn't a requirement. Unlike the tIME chunk, the +"Creation Time" tEXt chunk is not expected to be automatically changed +by the software. To facilitate the use of RFC 1123 dates, a function +png_convert_to_rfc1123_buffer(buffer, png_timep) is provided to +convert from PNG time to an RFC 1123 format string. The caller must provide +a writeable buffer of at least 29 bytes. + +Writing unknown chunks + +You can use the png_set_unknown_chunks function to queue up private chunks +for writing. You give it a chunk name, location, raw data, and a size. You +also must use png_set_keep_unknown_chunks() to ensure that libpng will +handle them. That's all there is to it. The chunks will be written by the +next following png_write_info_before_PLTE, png_write_info, or png_write_end +function, depending upon the specified location. Any chunks previously +read into the info structure's unknown-chunk list will also be written out +in a sequence that satisfies the PNG specification's ordering rules. + +Here is an example of writing two private chunks, prVt and miNE: + + #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + /* Set unknown chunk data */ + png_unknown_chunk unk_chunk[2]; + strcpy((char *) unk_chunk[0].name, "prVt"; + unk_chunk[0].data = (unsigned char *) "PRIVATE DATA"; + unk_chunk[0].size = strlen(unk_chunk[0].data)+1; + unk_chunk[0].location = PNG_HAVE_IHDR; + strcpy((char *) unk_chunk[1].name, "miNE"; + unk_chunk[1].data = (unsigned char *) "MY CHUNK DATA"; + unk_chunk[1].size = strlen(unk_chunk[0].data)+1; + unk_chunk[1].location = PNG_AFTER_IDAT; + png_set_unknown_chunks(write_ptr, write_info_ptr, + unk_chunk, 2); + /* Needed because miNE is not safe-to-copy */ + png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS, + (png_bytep) "miNE", 1); + # if PNG_LIBPNG_VER < 10600 + /* Deal with unknown chunk location bug in 1.5.x and earlier */ + png_set_unknown_chunk_location(png, info, 0, PNG_HAVE_IHDR); + png_set_unknown_chunk_location(png, info, 1, PNG_AFTER_IDAT); + # endif + # if PNG_LIBPNG_VER < 10500 + /* PNG_AFTER_IDAT writes two copies of the chunk prior to libpng-1.5.0, + * one before IDAT and another after IDAT, so don't use it; only use + * PNG_HAVE_IHDR location. This call resets the location previously + * set by assignment and png_set_unknown_chunk_location() for chunk 1. + */ + png_set_unknown_chunk_location(png, info, 1, PNG_HAVE_IHDR); + # endif + #endif + +The high-level write interface + +At this point there are two ways to proceed; through the high-level +write interface, or through a sequence of low-level write operations. +You can use the high-level interface if your image data is present +in the info structure. All defined output +transformations are permitted, enabled by the following masks. + + PNG_TRANSFORM_IDENTITY No transformation + PNG_TRANSFORM_PACKING Pack 1, 2 and 4-bit samples + PNG_TRANSFORM_PACKSWAP Change order of packed + pixels to LSB first + PNG_TRANSFORM_INVERT_MONO Invert monochrome images + PNG_TRANSFORM_SHIFT Normalize pixels to the + sBIT depth + PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA + to BGRA + PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA + to AG + PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity + to transparency + PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples + PNG_TRANSFORM_STRIP_FILLER Strip out filler + bytes (deprecated). + PNG_TRANSFORM_STRIP_FILLER_BEFORE Strip out leading + filler bytes + PNG_TRANSFORM_STRIP_FILLER_AFTER Strip out trailing + filler bytes + +If you have valid image data in the info structure (you can use +png_set_rows() to put image data in the info structure), simply do this: + + png_write_png(png_ptr, info_ptr, png_transforms, NULL) + +where png_transforms is an integer containing the bitwise OR of some set of +transformation flags. This call is equivalent to png_write_info(), +followed the set of transformations indicated by the transform mask, +then png_write_image(), and finally png_write_end(). + +(The final parameter of this call is not yet used. Someday it might point +to transformation parameters required by some future output transform.) + +You must use png_transforms and not call any png_set_transform() functions +when you use png_write_png(). + +The low-level write interface + +If you are going the low-level route instead, you are now ready to +write all the file information up to the actual image data. You do +this with a call to png_write_info(). + + png_write_info(png_ptr, info_ptr); + +Note that there is one transformation you may need to do before +png_write_info(). In PNG files, the alpha channel in an image is the +level of opacity. If your data is supplied as a level of transparency, +you can invert the alpha channel before you write it, so that 0 is +fully transparent and 255 (in 8-bit or paletted images) or 65535 +(in 16-bit images) is fully opaque, with + + png_set_invert_alpha(png_ptr); + +This must appear before png_write_info() instead of later with the +other transformations because in the case of paletted images the tRNS +chunk data has to be inverted before the tRNS chunk is written. If +your image is not a paletted image, the tRNS data (which in such cases +represents a single color to be rendered as transparent) won't need to +be changed, and you can safely do this transformation after your +png_write_info() call. + +If you need to write a private chunk that you want to appear before +the PLTE chunk when PLTE is present, you can write the PNG info in +two steps, and insert code to write your own chunk between them: + + png_write_info_before_PLTE(png_ptr, info_ptr); + png_set_unknown_chunks(png_ptr, info_ptr, ...); + png_write_info(png_ptr, info_ptr); + +After you've written the file information, you can set up the library +to handle any special transformations of the image data. The various +ways to transform the data will be described in the order that they +should occur. This is important, as some of these change the color +type and/or bit depth of the data, and some others only work on +certain color types and bit depths. Even though each transformation +checks to see if it has data that it can do something with, you should +make sure to only enable a transformation if it will be valid for the +data. For example, don't swap red and blue on grayscale data. + +PNG files store RGB pixels packed into 3 or 6 bytes. This code tells +the library to strip input data that has 4 or 8 bytes per pixel down +to 3 or 6 bytes (or strip 2 or 4-byte grayscale+filler data to 1 or 2 +bytes per pixel). + + png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); + +where the 0 is unused, and the location is either PNG_FILLER_BEFORE or +PNG_FILLER_AFTER, depending upon whether the filler byte in the pixel +is stored XRGB or RGBX. + +PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as +they can, resulting in, for example, 8 pixels per byte for 1 bit files. +If the data is supplied at 1 pixel per byte, use this code, which will +correctly pack the pixels into a single byte: + + png_set_packing(png_ptr); + +PNG files reduce possible bit depths to 1, 2, 4, 8, and 16. If your +data is of another bit depth, you can write an sBIT chunk into the +file so that decoders can recover the original data if desired. + + /* Set the true bit depth of the image data */ + if (color_type & PNG_COLOR_MASK_COLOR) + { + sig_bit.red = true_bit_depth; + sig_bit.green = true_bit_depth; + sig_bit.blue = true_bit_depth; + } + + else + { + sig_bit.gray = true_bit_depth; + } + + if (color_type & PNG_COLOR_MASK_ALPHA) + { + sig_bit.alpha = true_bit_depth; + } + + png_set_sBIT(png_ptr, info_ptr, &sig_bit); + +If the data is stored in the row buffer in a bit depth other than +one supported by PNG (e.g. 3 bit data in the range 0-7 for a 4-bit PNG), +this will scale the values to appear to be the correct bit depth as +is required by PNG. + + png_set_shift(png_ptr, &sig_bit); + +PNG files store 16-bit pixels in network byte order (big-endian, +ie. most significant bits first). This code would be used if they are +supplied the other way (little-endian, i.e. least significant bits +first, the way PCs store them): + + if (bit_depth > 8) + png_set_swap(png_ptr); + +If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you +need to change the order the pixels are packed into bytes, you can use: + + if (bit_depth < 8) + png_set_packswap(png_ptr); + +PNG files store 3 color pixels in red, green, blue order. This code +would be used if they are supplied as blue, green, red: + + png_set_bgr(png_ptr); + +PNG files describe monochrome as black being zero and white being +one. This code would be used if the pixels are supplied with this reversed +(black being one and white being zero): + + png_set_invert_mono(png_ptr); + +Finally, you can write your own transformation function if none of +the existing ones meets your needs. This is done by setting a callback +with + + png_set_write_user_transform_fn(png_ptr, + write_transform_fn); + +You must supply the function + + void write_transform_fn(png_structp png_ptr, png_row_infop + row_info, png_bytep data) + +See pngtest.c for a working example. Your function will be called +before any of the other transformations are processed. If supported +libpng also supplies an information routine that may be called from +your callback: + + png_get_current_row_number(png_ptr); + png_get_current_pass_number(png_ptr); + +This returns the current row passed to the transform. With interlaced +images the value returned is the row in the input sub-image image. Use +PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to +find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass). + +The discussion of interlace handling above contains more information on how to +use these values. + +You can also set up a pointer to a user structure for use by your +callback function. + + png_set_user_transform_info(png_ptr, user_ptr, 0, 0); + +The user_channels and user_depth parameters of this function are ignored +when writing; you can set them to zero as shown. + +You can retrieve the pointer via the function png_get_user_transform_ptr(). +For example: + + voidp write_user_transform_ptr = + png_get_user_transform_ptr(png_ptr); + +It is possible to have libpng flush any pending output, either manually, +or automatically after a certain number of lines have been written. To +flush the output stream a single time call: + + png_write_flush(png_ptr); + +and to have libpng flush the output stream periodically after a certain +number of scanlines have been written, call: + + png_set_flush(png_ptr, nrows); + +Note that the distance between rows is from the last time png_write_flush() +was called, or the first row of the image if it has never been called. +So if you write 50 lines, and then png_set_flush 25, it will flush the +output on the next scanline, and every 25 lines thereafter, unless +png_write_flush() is called before 25 more lines have been written. +If nrows is too small (less than about 10 lines for a 640 pixel wide +RGB image) the image compression may decrease noticeably (although this +may be acceptable for real-time applications). Infrequent flushing will +only degrade the compression performance by a few percent over images +that do not use flushing. + +Writing the image data + +That's it for the transformations. Now you can write the image data. +The simplest way to do this is in one function call. If you have the +whole image in memory, you can just call png_write_image() and libpng +will write the image. You will need to pass in an array of pointers to +each row. This function automatically handles interlacing, so you don't +need to call png_set_interlace_handling() or call this function multiple +times, or any of that other stuff necessary with png_write_rows(). + + png_write_image(png_ptr, row_pointers); + +where row_pointers is: + + png_byte *row_pointers[height]; + +You can point to void or char or whatever you use for pixels. + +If you don't want to write the whole image at once, you can +use png_write_rows() instead. If the file is not interlaced, +this is simple: + + png_write_rows(png_ptr, row_pointers, + number_of_rows); + +row_pointers is the same as in the png_write_image() call. + +If you are just writing one row at a time, you can do this with +a single row_pointer instead of an array of row_pointers: + + png_bytep row_pointer = row; + + png_write_row(png_ptr, row_pointer); + +When the file is interlaced, things can get a good deal more complicated. +The only currently (as of the PNG Specification version 1.2, dated July +1999) defined interlacing scheme for PNG files is the "Adam7" interlace +scheme, that breaks down an image into seven smaller images of varying +size. libpng will build these images for you, or you can do them +yourself. If you want to build them yourself, see the PNG specification +for details of which pixels to write when. + +If you don't want libpng to handle the interlacing details, just +use png_set_interlace_handling() and call png_write_rows() the +correct number of times to write all the sub-images +(png_set_interlace_handling() returns the number of sub-images.) + +If you want libpng to build the sub-images, call this before you start +writing any rows: + + number_of_passes = png_set_interlace_handling(png_ptr); + +This will return the number of passes needed. Currently, this is seven, +but may change if another interlace type is added. + +Then write the complete image number_of_passes times. + + png_write_rows(png_ptr, row_pointers, number_of_rows); + +Think carefully before you write an interlaced image. Typically code that +reads such images reads all the image data into memory, uncompressed, before +doing any processing. Only code that can display an image on the fly can +take advantage of the interlacing and even then the image has to be exactly +the correct size for the output device, because scaling an image requires +adjacent pixels and these are not available until all the passes have been +read. + +If you do write an interlaced image you will hardly ever need to handle +the interlacing yourself. Call png_set_interlace_handling() and use the +approach described above. + +The only time it is conceivable that you will really need to write an +interlaced image pass-by-pass is when you have read one pass by pass and +made some pixel-by-pixel transformation to it, as described in the read +code above. In this case use the PNG_PASS_ROWS and PNG_PASS_COLS macros +to determine the size of each sub-image in turn and simply write the rows +you obtained from the read code. + +Finishing a sequential write + +After you are finished writing the image, you should finish writing +the file. If you are interested in writing comments or time, you should +pass an appropriately filled png_info pointer. If you are not interested, +you can pass NULL. + + png_write_end(png_ptr, info_ptr); + +When you are done, you can free all memory used by libpng like this: + + png_destroy_write_struct(&png_ptr, &info_ptr); + +It is also possible to individually free the info_ptr members that +point to libpng-allocated storage with the following function: + + png_free_data(png_ptr, info_ptr, mask, seq) + + mask - identifies data to be freed, a mask + containing the bitwise OR of one or + more of + PNG_FREE_PLTE, PNG_FREE_TRNS, + PNG_FREE_HIST, PNG_FREE_ICCP, + PNG_FREE_PCAL, PNG_FREE_ROWS, + PNG_FREE_SCAL, PNG_FREE_SPLT, + PNG_FREE_TEXT, PNG_FREE_UNKN, + or simply PNG_FREE_ALL + + seq - sequence number of item to be freed + (-1 for all items) + +This function may be safely called when the relevant storage has +already been freed, or has not yet been allocated, or was allocated +by the user and not by libpng, and will in those cases do nothing. +The "seq" parameter is ignored if only one item of the selected data +type, such as PLTE, is allowed. If "seq" is not -1, and multiple items +are allowed for the data type identified in the mask, such as text or +sPLT, only the n'th item in the structure is freed, where n is "seq". + +If you allocated data such as a palette that you passed in to libpng +with png_set_*, you must not free it until just before the call to +png_destroy_write_struct(). + +The default behavior is only to free data that was allocated internally +by libpng. This can be changed, so that libpng will not free the data, +or so that it will free data that was allocated by the user with png_malloc() +or png_calloc() and passed in via a png_set_*() function, with + + png_data_freer(png_ptr, info_ptr, freer, mask) + + freer - one of + PNG_DESTROY_WILL_FREE_DATA + PNG_SET_WILL_FREE_DATA + PNG_USER_WILL_FREE_DATA + + mask - which data elements are affected + same choices as in png_free_data() + +For example, to transfer responsibility for some data from a read structure +to a write structure, you could use + + png_data_freer(read_ptr, read_info_ptr, + PNG_USER_WILL_FREE_DATA, + PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST) + + png_data_freer(write_ptr, write_info_ptr, + PNG_DESTROY_WILL_FREE_DATA, + PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST) + +thereby briefly reassigning responsibility for freeing to the user but +immediately afterwards reassigning it once more to the write_destroy +function. Having done this, it would then be safe to destroy the read +structure and continue to use the PLTE, tRNS, and hIST data in the write +structure. + +This function only affects data that has already been allocated. +You can call this function before calling after the png_set_*() functions +to control whether the user or png_destroy_*() is supposed to free the data. +When the user assumes responsibility for libpng-allocated data, the +application must use +png_free() to free it, and when the user transfers responsibility to libpng +for data that the user has allocated, the user must have used png_malloc() +or png_calloc() to allocate it. + +If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword +separately, do not transfer responsibility for freeing text_ptr to libpng, +because when libpng fills a png_text structure it combines these members with +the key member, and png_free_data() will free only text_ptr.key. Similarly, +if you transfer responsibility for free'ing text_ptr from libpng to your +application, your application must not separately free those members. +For a more compact example of writing a PNG image, see the file example.c. + +V. Simplified API + +The simplified API, which became available in libpng-1.6.0, hides the details +of both libpng and the PNG file format itself. +It allows PNG files to be read into a very limited number of +in-memory bitmap formats or to be written from the same formats. If these +formats do not accommodate your needs then you can, and should, use the more +sophisticated APIs above - these support a wide variety of in-memory formats +and a wide variety of sophisticated transformations to those formats as well +as a wide variety of APIs to manipulate ancillary information. + +To read a PNG file using the simplified API: + + 1) Declare a 'png_image' structure (see below) on the stack, set the + version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL + (this is REQUIRED, your program may crash if you don't do it.) + + 2) Call the appropriate png_image_begin_read... function. + + 3) Set the png_image 'format' member to the required sample format. + + 4) Allocate a buffer for the image and, if required, the color-map. + + 5) Call png_image_finish_read to read the image and, if required, the + color-map into your buffers. + +There are no restrictions on the format of the PNG input itself; all valid +color types, bit depths, and interlace methods are acceptable, and the +input image is transformed as necessary to the requested in-memory format +during the png_image_finish_read() step. The only caveat is that if you +request a color-mapped image from a PNG that is full-color or makes +complex use of an alpha channel the transformation is extremely lossy and the +result may look terrible. + +To write a PNG file using the simplified API: + + 1) Declare a 'png_image' structure on the stack and memset() + it to all zero. + + 2) Initialize the members of the structure that describe the + image, setting the 'format' member to the format of the + image samples. + + 3) Call the appropriate png_image_write... function with a + pointer to the image and, if necessary, the color-map to write + the PNG data. + +png_image is a structure that describes the in-memory format of an image +when it is being read or defines the in-memory format of an image that you +need to write. The "png_image" structure contains the following members: + + png_controlp opaque Initialize to NULL, free with png_image_free + png_uint_32 version Set to PNG_IMAGE_VERSION + png_uint_32 width Image width in pixels (columns) + png_uint_32 height Image height in pixels (rows) + png_uint_32 format Image format as defined below + png_uint_32 flags A bit mask containing informational flags + png_uint_32 colormap_entries; Number of entries in the color-map + png_uint_32 warning_or_error; + char message[64]; + +In the event of an error or warning the "warning_or_error" +field will be set to a non-zero value and the 'message' field will contain +a '\0' terminated string with the libpng error or warning message. If both +warnings and an error were encountered, only the error is recorded. If there +are multiple warnings, only the first one is recorded. + +The upper 30 bits of the "warning_or_error" value are reserved; the low two +bits contain a two bit code such that a value more than 1 indicates a failure +in the API just called: + + 0 - no warning or error + 1 - warning + 2 - error + 3 - error preceded by warning + +The pixels (samples) of the image have one to four channels whose components +have original values in the range 0 to 1.0: + + 1: A single gray or luminance channel (G). + 2: A gray/luminance channel and an alpha channel (GA). + 3: Three red, green, blue color channels (RGB). + 4: Three color channels and an alpha channel (RGBA). + +The channels are encoded in one of two ways: + + a) As a small integer, value 0..255, contained in a single byte. For the +alpha channel the original value is simply value/255. For the color or +luminance channels the value is encoded according to the sRGB specification +and matches the 8-bit format expected by typical display devices. + +The color/gray channels are not scaled (pre-multiplied) by the alpha +channel and are suitable for passing to color management software. + + b) As a value in the range 0..65535, contained in a 2-byte integer, in +the native byte order of the platform on which the application is running. +All channels can be converted to the original value by dividing by 65535; all +channels are linear. Color channels use the RGB encoding (RGB end-points) of +the sRGB specification. This encoding is identified by the +PNG_FORMAT_FLAG_LINEAR flag below. + +When the simplified API needs to convert between sRGB and linear colorspaces, +the actual sRGB transfer curve defined in the sRGB specification (see the +article at https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 +approximation used elsewhere in libpng. + +When an alpha channel is present it is expected to denote pixel coverage +of the color or luminance channels and is returned as an associated alpha +channel: the color/gray channels are scaled (pre-multiplied) by the alpha +value. + +The samples are either contained directly in the image data, between 1 and 8 +bytes per pixel according to the encoding, or are held in a color-map indexed +by bytes in the image data. In the case of a color-map the color-map entries +are individual samples, encoded as above, and the image data has one byte per +pixel to select the relevant sample from the color-map. + +PNG_FORMAT_* + +The #defines to be used in png_image::format. Each #define identifies a +particular layout of channel data and, if present, alpha values. There are +separate defines for each of the two component encodings. + +A format is built up using single bit flag values. All combinations are +valid. Formats can be built up from the flag values or you can use one of +the predefined values below. When testing formats always use the FORMAT_FLAG +macros to test for individual features - future versions of the library may +add new flags. + +When reading or writing color-mapped images the format should be set to the +format of the entries in the color-map then png_image_{read,write}_colormap +called to read or write the color-map and set the format correctly for the +image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! + +NOTE: libpng can be built with particular features disabled. If you see +compiler errors because the definition of one of the following flags has been +compiled out it is because libpng does not have the required support. It is +possible, however, for the libpng configuration to enable the format on just +read or just write; in that case you may see an error at run time. +You can guard against this by checking for the definition of the +appropriate "_SUPPORTED" macro, one of: + + PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED + + PNG_FORMAT_FLAG_ALPHA format with an alpha channel + PNG_FORMAT_FLAG_COLOR color format: otherwise grayscale + PNG_FORMAT_FLAG_LINEAR 2-byte channels else 1-byte + PNG_FORMAT_FLAG_COLORMAP image data is color-mapped + PNG_FORMAT_FLAG_BGR BGR colors, else order is RGB + PNG_FORMAT_FLAG_AFIRST alpha channel comes first + +Supported formats are as follows. Future versions of libpng may support more +formats; for compatibility with older versions simply check if the format +macro is defined using #ifdef. These defines describe the in-memory layout +of the components of the pixels of the image. + +First the single byte (sRGB) formats: + + PNG_FORMAT_GRAY + PNG_FORMAT_GA + PNG_FORMAT_AG + PNG_FORMAT_RGB + PNG_FORMAT_BGR + PNG_FORMAT_RGBA + PNG_FORMAT_ARGB + PNG_FORMAT_BGRA + PNG_FORMAT_ABGR + +Then the linear 2-byte formats. When naming these "Y" is used to +indicate a luminance (gray) channel. The component order within the pixel +is always the same - there is no provision for swapping the order of the +components in the linear format. The components are 16-bit integers in +the native byte order for your platform, and there is no provision for +swapping the bytes to a different endian condition. + + PNG_FORMAT_LINEAR_Y + PNG_FORMAT_LINEAR_Y_ALPHA + PNG_FORMAT_LINEAR_RGB + PNG_FORMAT_LINEAR_RGB_ALPHA + +With color-mapped formats the image data is one byte for each pixel. The byte +is an index into the color-map which is formatted as above. To obtain a +color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP +to one of the above definitions, or you can use one of the definitions below. + + PNG_FORMAT_RGB_COLORMAP + PNG_FORMAT_BGR_COLORMAP + PNG_FORMAT_RGBA_COLORMAP + PNG_FORMAT_ARGB_COLORMAP + PNG_FORMAT_BGRA_COLORMAP + PNG_FORMAT_ABGR_COLORMAP + +PNG_IMAGE macros + +These are convenience macros to derive information from a png_image +structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the +actual image sample values - either the entries in the color-map or the +pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values +for the pixels and will always return 1 for color-mapped formats. The +remaining macros return information about the rows in the image and the +complete image. + +NOTE: All the macros that take a png_image::format parameter are compile time +constants if the format parameter is, itself, a constant. Therefore these +macros can be used in array declarations and case labels where required. +Similarly the macros are also pre-processor constants (sizeof is not used) so +they can be used in #if tests. + + PNG_IMAGE_SAMPLE_CHANNELS(fmt) + Returns the total number of channels in a given format: 1..4 + + PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt) + Returns the size in bytes of a single component of a pixel or color-map + entry (as appropriate) in the image: 1 or 2. + + PNG_IMAGE_SAMPLE_SIZE(fmt) + This is the size of the sample data for one sample. If the image is + color-mapped it is the size of one color-map entry (and image pixels are + one byte in size), otherwise it is the size of one image pixel. + + PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt) + The maximum size of the color-map required by the format expressed in a + count of components. This can be used to compile-time allocate a + color-map: + + png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; + + png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; + + Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the + information from one of the png_image_begin_read_ APIs and dynamically + allocate the required memory. + + PNG_IMAGE_COLORMAP_SIZE(fmt) + The size of the color-map required by the format; this is the size of the + color-map buffer passed to the png_image_{read,write}_colormap APIs. It is + a fixed number determined by the format so can easily be allocated on the + stack if necessary. + +Corresponding information about the pixels + + PNG_IMAGE_PIXEL_CHANNELS(fmt) + The number of separate channels (components) in a pixel; 1 for a + color-mapped image. + + PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ + The size, in bytes, of each component in a pixel; 1 for a color-mapped + image. + + PNG_IMAGE_PIXEL_SIZE(fmt) + The size, in bytes, of a complete pixel; 1 for a color-mapped image. + +Information about the whole row, or whole image + + PNG_IMAGE_ROW_STRIDE(image) + Returns the total number of components in a single row of the image; this + is the minimum 'row stride', the minimum count of components between each + row. For a color-mapped image this is the minimum number of bytes in a + row. + + If you need the stride measured in bytes, row_stride_bytes is + PNG_IMAGE_ROW_STRIDE(image) * PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt) + plus any padding bytes that your application might need, for example + to start the next row on a 4-byte boundary. + + PNG_IMAGE_BUFFER_SIZE(image, row_stride) + Return the size, in bytes, of an image buffer given a png_image and a row + stride - the number of components to leave space for in each row. + + PNG_IMAGE_SIZE(image) + Return the size, in bytes, of the image in memory given just a png_image; + the row stride is the minimum stride required for the image. + + PNG_IMAGE_COLORMAP_SIZE(image) + Return the size, in bytes, of the color-map of this image. If the image + format is not a color-map format this will return a size sufficient for + 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if + you don't want to allocate a color-map in this case. + +PNG_IMAGE_FLAG_* + +Flags containing additional information about the image are held in +the 'flags' field of png_image. + + PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB == 0x01 + This indicates that the RGB values of the in-memory bitmap do not + correspond to the red, green and blue end-points defined by sRGB. + + PNG_IMAGE_FLAG_FAST == 0x02 + On write emphasise speed over compression; the resultant PNG file will be + larger but will be produced significantly faster, particular for large + images. Do not use this option for images which will be distributed, only + used it when producing intermediate files that will be read back in + repeatedly. For a typical 24-bit image the option will double the read + speed at the cost of increasing the image size by 25%, however for many + more compressible images the PNG file can be 10 times larger with only a + slight speed gain. + + PNG_IMAGE_FLAG_16BIT_sRGB == 0x04 + On read if the image is a 16-bit per component image and there is no gAMA + or sRGB chunk assume that the components are sRGB encoded. Notice that + images output by the simplified API always have gamma information; setting + this flag only affects the interpretation of 16-bit images from an + external source. It is recommended that the application expose this flag + to the user; the user can normally easily recognize the difference between + linear and sRGB encoding. This flag has no effect on write - the data + passed to the write APIs must have the correct encoding (as defined + above.) + + If the flag is not set (the default) input 16-bit per component data is + assumed to be linear. + + NOTE: the flag can only be set after the png_image_begin_read_ call, + because that call initializes the 'flags' field. + +READ APIs + + The png_image passed to the read APIs must have been initialized by setting + the png_controlp field 'opaque' to NULL (or, better, memset the whole thing.) + + int png_image_begin_read_from_file( png_imagep image, + const char *file_name) + + The named file is opened for read and the image header + is filled in from the PNG header in the file. + + int png_image_begin_read_from_stdio (png_imagep image, + FILE* file) + + The PNG header is read from the stdio FILE object. + + int png_image_begin_read_from_memory(png_imagep image, + png_const_voidp memory, size_t size) + + The PNG header is read from the given memory buffer. + + int png_image_finish_read(png_imagep image, + png_colorp background, void *buffer, + png_int_32 row_stride, void *colormap)); + + Finish reading the image into the supplied buffer and + clean up the png_image structure. + + row_stride is the step, in png_byte or png_uint_16 units + as appropriate, between adjacent rows. A positive stride + indicates that the top-most row is first in the buffer - + the normal top-down arrangement. A negative stride + indicates that the bottom-most row is first in the buffer. + + background need only be supplied if an alpha channel must + be removed from a png_byte format and the removal is to be + done by compositing on a solid color; otherwise it may be + NULL and any composition will be done directly onto the + buffer. The value is an sRGB color to use for the + background, for grayscale output the green channel is used. + + For linear output removing the alpha channel is always done + by compositing on black. + + void png_image_free(png_imagep image) + + Free any data allocated by libpng in image->opaque, + setting the pointer to NULL. May be called at any time + after the structure is initialized. + +When the simplified API needs to convert between sRGB and linear colorspaces, +the actual sRGB transfer curve defined in the sRGB specification (see the +article at https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 +approximation used elsewhere in libpng. + +WRITE APIS + +For write you must initialize a png_image structure to describe the image to +be written: + + version: must be set to PNG_IMAGE_VERSION + opaque: must be initialized to NULL + width: image width in pixels + height: image height in rows + format: the format of the data you wish to write + flags: set to 0 unless one of the defined flags applies; set + PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images + where the RGB values do not correspond to the colors in sRGB. + colormap_entries: set to the number of entries in the color-map (0 to 256) + + int png_image_write_to_file, (png_imagep image, + const char *file, int convert_to_8bit, const void *buffer, + png_int_32 row_stride, const void *colormap)); + + Write the image to the named file. + + int png_image_write_to_memory (png_imagep image, void *memory, + png_alloc_size_t * PNG_RESTRICT memory_bytes, + int convert_to_8_bit, const void *buffer, ptrdiff_t row_stride, + const void *colormap)); + + Write the image to memory. + + int png_image_write_to_stdio(png_imagep image, FILE *file, + int convert_to_8_bit, const void *buffer, + png_int_32 row_stride, const void *colormap) + + Write the image to the given (FILE*). + +With all write APIs if image is in one of the linear formats with +(png_uint_16) data then setting convert_to_8_bit will cause the output to be +a (png_byte) PNG gamma encoded according to the sRGB specification, otherwise +a 16-bit linear encoded PNG file is written. + +With all APIs row_stride is handled as in the read APIs - it is the spacing +from one row to the next in component sized units (float) and if negative +indicates a bottom-up row layout in the buffer. If you pass zero, libpng will +calculate the row_stride for you from the width and number of channels. + +Note that the write API does not support interlacing, sub-8-bit pixels, +indexed (paletted) images, or most ancillary chunks. + +VI. Modifying/Customizing libpng + +There are two issues here. The first is changing how libpng does +standard things like memory allocation, input/output, and error handling. +The second deals with more complicated things like adding new chunks, +adding new transformations, and generally changing how libpng works. +Both of those are compile-time issues; that is, they are generally +determined at the time the code is written, and there is rarely a need +to provide the user with a means of changing them. + +Memory allocation, input/output, and error handling + +All of the memory allocation, input/output, and error handling in libpng +goes through callbacks that are user-settable. The default routines are +in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively. To change +these functions, call the appropriate png_set_*_fn() function. + +Memory allocation is done through the functions png_malloc(), png_calloc(), +and png_free(). The png_malloc() and png_free() functions currently just +call the standard C functions and png_calloc() calls png_malloc() and then +clears the newly allocated memory to zero; note that png_calloc(png_ptr, size) +is not the same as the calloc(number, size) function provided by stdlib.h. +There is limited support for certain systems with segmented memory +architectures and the types of pointers declared by png.h match this; you +will have to use appropriate pointers in your application. If you prefer +to use a different method of allocating and freeing data, you can use +png_create_read_struct_2() or png_create_write_struct_2() to register your +own functions as described above. These functions also provide a void +pointer that can be retrieved via + + mem_ptr=png_get_mem_ptr(png_ptr); + +Your replacement memory functions must have prototypes as follows: + + png_voidp malloc_fn(png_structp png_ptr, + png_alloc_size_t size); + + void free_fn(png_structp png_ptr, png_voidp ptr); + +Your malloc_fn() must return NULL in case of failure. The png_malloc() +function will normally call png_error() if it receives a NULL from the +system memory allocator or from your replacement malloc_fn(). + +Your free_fn() will never be called with a NULL ptr, since libpng's +png_free() checks for NULL before calling free_fn(). + +Input/Output in libpng is done through png_read() and png_write(), +which currently just call fread() and fwrite(). The FILE * is stored in +png_struct and is initialized via png_init_io(). If you wish to change +the method of I/O, the library supplies callbacks that you can set +through the function png_set_read_fn() and png_set_write_fn() at run +time, instead of calling the png_init_io() function. These functions +also provide a void pointer that can be retrieved via the function +png_get_io_ptr(). For example: + + png_set_read_fn(png_structp read_ptr, + voidp read_io_ptr, png_rw_ptr read_data_fn) + + png_set_write_fn(png_structp write_ptr, + voidp write_io_ptr, png_rw_ptr write_data_fn, + png_flush_ptr output_flush_fn); + + voidp read_io_ptr = png_get_io_ptr(read_ptr); + voidp write_io_ptr = png_get_io_ptr(write_ptr); + +The replacement I/O functions must have prototypes as follows: + + void user_read_data(png_structp png_ptr, + png_bytep data, size_t length); + + void user_write_data(png_structp png_ptr, + png_bytep data, size_t length); + + void user_flush_data(png_structp png_ptr); + +The user_read_data() function is responsible for detecting and +handling end-of-data errors. + +Supplying NULL for the read, write, or flush functions sets them back +to using the default C stream functions, which expect the io_ptr to +point to a standard *FILE structure. It is probably a mistake +to use NULL for one of write_data_fn and output_flush_fn but not both +of them, unless you have built libpng with PNG_NO_WRITE_FLUSH defined. +It is an error to read from a write stream, and vice versa. + +Error handling in libpng is done through png_error() and png_warning(). +Errors handled through png_error() are fatal, meaning that png_error() +should never return to its caller. Currently, this is handled via +setjmp() and longjmp() (unless you have compiled libpng with +PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()), +but you could change this to do things like exit() if you should wish, +as long as your function does not return. + +On non-fatal errors, png_warning() is called +to print a warning message, and then control returns to the calling code. +By default png_error() and png_warning() print a message on stderr via +fprintf() unless the library is compiled with PNG_NO_CONSOLE_IO defined +(because you don't want the messages) or PNG_NO_STDIO defined (because +fprintf() isn't available). If you wish to change the behavior of the error +functions, you will need to set up your own message callbacks. These +functions are normally supplied at the time that the png_struct is created. +It is also possible to redirect errors and warnings to your own replacement +functions after png_create_*_struct() has been called by calling: + + png_set_error_fn(png_structp png_ptr, + png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warning_fn); + +If NULL is supplied for either error_fn or warning_fn, then the libpng +default function will be used, calling fprintf() and/or longjmp() if a +problem is encountered. The replacement error functions should have +parameters as follows: + + void user_error_fn(png_structp png_ptr, + png_const_charp error_msg); + + void user_warning_fn(png_structp png_ptr, + png_const_charp warning_msg); + +Then, within your user_error_fn or user_warning_fn, you can retrieve +the error_ptr if you need it, by calling + + png_voidp error_ptr = png_get_error_ptr(png_ptr); + +The motivation behind using setjmp() and longjmp() is the C++ throw and +catch exception handling methods. This makes the code much easier to write, +as there is no need to check every return code of every function call. +However, there are some uncertainties about the status of local variables +after a longjmp, so the user may want to be careful about doing anything +after setjmp returns non-zero besides returning itself. Consult your +compiler documentation for more details. For an alternative approach, you +may wish to use the "cexcept" facility (see https://cexcept.sourceforge.io/), +which is illustrated in pngvalid.c and in contrib/visupng. + +Beginning in libpng-1.4.0, the png_set_benign_errors() API became available. +You can use this to handle certain errors (normally handled as errors) +as warnings. + + png_set_benign_errors (png_ptr, int allowed); + + allowed: 0: treat png_benign_error() as an error. + 1: treat png_benign_error() as a warning. + +As of libpng-1.6.0, the default condition is to treat benign errors as +warnings while reading and as errors while writing. + +Custom chunks + +If you need to read or write custom chunks, you may need to get deeper +into the libpng code. The library now has mechanisms for storing +and writing chunks of unknown type; you can even declare callbacks +for custom chunks. However, this may not be good enough if the +library code itself needs to know about interactions between your +chunk and existing `intrinsic' chunks. + +If you need to write a new intrinsic chunk, first read the PNG +specification. Acquire a first level of understanding of how it works. +Pay particular attention to the sections that describe chunk names, +and look at how other chunks were designed, so you can do things +similarly. Second, check out the sections of libpng that read and +write chunks. Try to find a chunk that is similar to yours and use +it as a template. More details can be found in the comments inside +the code. It is best to handle private or unknown chunks in a generic method, +via callback functions, instead of by modifying libpng functions. This +is illustrated in pngtest.c, which uses a callback function to handle a +private "vpAg" chunk and the new "sTER" chunk, which are both unknown to +libpng. + +If you wish to write your own transformation for the data, look through +the part of the code that does the transformations, and check out some of +the simpler ones to get an idea of how they work. Try to find a similar +transformation to the one you want to add and copy off of it. More details +can be found in the comments inside the code itself. + +Configuring for gui/windowing platforms: + +You will need to write new error and warning functions that use the GUI +interface, as described previously, and set them to be the error and +warning functions at the time that png_create_*_struct() is called, +in order to have them available during the structure initialization. +They can be changed later via png_set_error_fn(). On some compilers, +you may also have to change the memory allocators (png_malloc, etc.). + +Configuring zlib: + +There are special functions to configure the compression. Perhaps the +most useful one changes the compression level, which currently uses +input compression values in the range 0 - 9. The library normally +uses the default compression level (Z_DEFAULT_COMPRESSION = 6). Tests +have shown that for a large majority of images, compression values in +the range 3-6 compress nearly as well as higher levels, and do so much +faster. For online applications it may be desirable to have maximum speed +(Z_BEST_SPEED = 1). With versions of zlib after v0.99, you can also +specify no compression (Z_NO_COMPRESSION = 0), but this would create +files larger than just storing the raw bitmap. You can specify the +compression level by calling: + + #include zlib.h + png_set_compression_level(png_ptr, level); + +Another useful one is to reduce the memory level used by the library. +The memory level defaults to 8, but it can be lowered if you are +short on memory (running DOS, for example, where you only have 640K). +Note that the memory level does have an effect on compression; among +other things, lower levels will result in sections of incompressible +data being emitted in smaller stored blocks, with a correspondingly +larger relative overhead of up to 15% in the worst case. + + #include zlib.h + png_set_compression_mem_level(png_ptr, level); + +The other functions are for configuring zlib. They are not recommended +for normal use and may result in writing an invalid PNG file. See +zlib.h for more information on what these mean. + + #include zlib.h + png_set_compression_strategy(png_ptr, + strategy); + + png_set_compression_window_bits(png_ptr, + window_bits); + + png_set_compression_method(png_ptr, method); + +This controls the size of the IDAT chunks (default 8192): + + png_set_compression_buffer_size(png_ptr, size); + +As of libpng version 1.5.4, additional APIs became +available to set these separately for non-IDAT +compressed chunks such as zTXt, iTXt, and iCCP: + + #include zlib.h + #if PNG_LIBPNG_VER >= 10504 + png_set_text_compression_level(png_ptr, level); + + png_set_text_compression_mem_level(png_ptr, level); + + png_set_text_compression_strategy(png_ptr, + strategy); + + png_set_text_compression_window_bits(png_ptr, + window_bits); + + png_set_text_compression_method(png_ptr, method); + #endif + +Controlling row filtering + +If you want to control whether libpng uses filtering or not, which +filters are used, and how it goes about picking row filters, you +can call one of these functions. The selection and configuration +of row filters can have a significant impact on the size and +encoding speed and a somewhat lesser impact on the decoding speed +of an image. Filtering is enabled by default for RGB and grayscale +images (with and without alpha), but not for paletted images nor +for any images with bit depths less than 8 bits/pixel. + +The 'method' parameter sets the main filtering method, which is +currently only '0' in the PNG 1.2 specification. The 'filters' +parameter sets which filter(s), if any, should be used for each +scanline. Possible values are PNG_ALL_FILTERS, PNG_NO_FILTERS, +or PNG_FAST_FILTERS to turn filtering on and off, or to turn on +just the fast-decoding subset of filters, respectively. + +Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB, +PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise +ORed together with '|' to specify one or more filters to use. +These filters are described in more detail in the PNG specification. +If you intend to change the filter type during the course of writing +the image, you should start with flags set for all of the filters +you intend to use so that libpng can initialize its internal +structures appropriately for all of the filter types. (Note that this +means the first row must always be adaptively filtered, because libpng +currently does not allocate the filter buffers until png_write_row() +is called for the first time.) + + filters = PNG_NO_FILTERS; + filters = PNG_ALL_FILTERS; + filters = PNG_FAST_FILTERS; + + or + + filters = PNG_FILTER_NONE | PNG_FILTER_SUB | + PNG_FILTER_UP | PNG_FILTER_AVG | + PNG_FILTER_PAETH; + + png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, + filters); + + The second parameter can also be + PNG_INTRAPIXEL_DIFFERENCING if you are + writing a PNG to be embedded in a MNG + datastream. This parameter must be the + same as the value of filter_method used + in png_set_IHDR(). + +Requesting debug printout + +The macro definition PNG_DEBUG can be used to request debugging +printout. Set it to an integer value in the range 0 to 3. Higher +numbers result in increasing amounts of debugging information. The +information is printed to the "stderr" file, unless another file +name is specified in the PNG_DEBUG_FILE macro definition. + +When PNG_DEBUG > 0, the following functions (macros) become available: + + png_debug(level, message) + png_debug1(level, message, p1) + png_debug2(level, message, p1, p2) + +in which "level" is compared to PNG_DEBUG to decide whether to print +the message, "message" is the formatted string to be printed, +and p1 and p2 are parameters that are to be embedded in the string +according to printf-style formatting directives. For example, + + png_debug1(2, "foo=%d", foo); + +is expanded to + + if (PNG_DEBUG > 2) + fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo); + +When PNG_DEBUG is defined but is zero, the macros aren't defined, but you +can still use PNG_DEBUG to control your own debugging: + + #ifdef PNG_DEBUG + fprintf(stderr, ... + #endif + +When PNG_DEBUG = 1, the macros are defined, but only png_debug statements +having level = 0 will be printed. There aren't any such statements in +this version of libpng, but if you insert some they will be printed. + +VII. MNG support + +The MNG specification (available at http://www.libpng.org/pub/mng) allows +certain extensions to PNG for PNG images that are embedded in MNG datastreams. +Libpng can support some of these extensions. To enable them, use the +png_permit_mng_features() function: + + feature_set = png_permit_mng_features(png_ptr, mask) + + mask is a png_uint_32 containing the bitwise OR of the + features you want to enable. These include + PNG_FLAG_MNG_EMPTY_PLTE + PNG_FLAG_MNG_FILTER_64 + PNG_ALL_MNG_FEATURES + + feature_set is a png_uint_32 that is the bitwise AND of + your mask with the set of MNG features that is + supported by the version of libpng that you are using. + +It is an error to use this function when reading or writing a standalone +PNG file with the PNG 8-byte signature. The PNG datastream must be wrapped +in a MNG datastream. As a minimum, it must have the MNG 8-byte signature +and the MHDR and MEND chunks. Libpng does not provide support for these +or any other MNG chunks; your application must provide its own support for +them. You may wish to consider using libmng (available at +https://www.libmng.com/) instead. + +VIII. Changes to Libpng from version 0.88 + +It should be noted that versions of libpng later than 0.96 are not +distributed by the original libpng author, Guy Schalnat, nor by +Andreas Dilger, who had taken over from Guy during 1996 and 1997, and +distributed versions 0.89 through 0.96, but rather by another member +of the original PNG Group, Glenn Randers-Pehrson. Guy and Andreas are +still alive and well, but they have moved on to other things. + +The old libpng functions png_read_init(), png_write_init(), +png_info_init(), png_read_destroy(), and png_write_destroy() have been +moved to PNG_INTERNAL in version 0.95 to discourage their use. These +functions will be removed from libpng version 1.4.0. + +The preferred method of creating and initializing the libpng structures is +via the png_create_read_struct(), png_create_write_struct(), and +png_create_info_struct() because they isolate the size of the structures +from the application, allow version error checking, and also allow the +use of custom error handling routines during the initialization, which +the old functions do not. The functions png_read_destroy() and +png_write_destroy() do not actually free the memory that libpng +allocated for these structs, but just reset the data structures, so they +can be used instead of png_destroy_read_struct() and +png_destroy_write_struct() if you feel there is too much system overhead +allocating and freeing the png_struct for each image read. + +Setting the error callbacks via png_set_message_fn() before +png_read_init() as was suggested in libpng-0.88 is no longer supported +because this caused applications that do not use custom error functions +to fail if the png_ptr was not initialized to zero. It is still possible +to set the error callbacks AFTER png_read_init(), or to change them with +png_set_error_fn(), which is essentially the same function, but with a new +name to force compilation errors with applications that try to use the old +method. + +Support for the sCAL, iCCP, iTXt, and sPLT chunks was added at libpng-1.0.6; +however, iTXt support was not enabled by default. + +Starting with version 1.0.7, you can find out which version of the library +you are using at run-time: + + png_uint_32 libpng_vn = png_access_version_number(); + +The number libpng_vn is constructed from the major version, minor +version with leading zero, and release number with leading zero, +(e.g., libpng_vn for version 1.0.7 is 10007). + +Note that this function does not take a png_ptr, so you can call it +before you've created one. + +You can also check which version of png.h you used when compiling your +application: + + png_uint_32 application_vn = PNG_LIBPNG_VER; + +IX. Changes to Libpng from version 1.0.x to 1.2.x + +Support for user memory management was enabled by default. To +accomplish this, the functions png_create_read_struct_2(), +png_create_write_struct_2(), png_set_mem_fn(), png_get_mem_ptr(), +png_malloc_default(), and png_free_default() were added. + +Support for the iTXt chunk has been enabled by default as of +version 1.2.41. + +Support for certain MNG features was enabled. + +Support for numbered error messages was added. However, we never got +around to actually numbering the error messages. The function +png_set_strip_error_numbers() was added (Note: the prototype for this +function was inadvertently removed from png.h in PNG_NO_ASSEMBLER_CODE +builds of libpng-1.2.15. It was restored in libpng-1.2.36). + +The png_malloc_warn() function was added at libpng-1.2.3. This issues +a png_warning and returns NULL instead of aborting when it fails to +acquire the requested memory allocation. + +Support for setting user limits on image width and height was enabled +by default. The functions png_set_user_limits(), png_get_user_width_max(), +and png_get_user_height_max() were added at libpng-1.2.6. + +The png_set_add_alpha() function was added at libpng-1.2.7. + +The function png_set_expand_gray_1_2_4_to_8() was added at libpng-1.2.9. +Unlike png_set_gray_1_2_4_to_8(), the new function does not expand the +tRNS chunk to alpha. The png_set_gray_1_2_4_to_8() function is +deprecated. + +A number of macro definitions in support of runtime selection of +assembler code features (especially Intel MMX code support) were +added at libpng-1.2.0: + + PNG_ASM_FLAG_MMX_SUPPORT_COMPILED + PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU + PNG_ASM_FLAG_MMX_READ_COMBINE_ROW + PNG_ASM_FLAG_MMX_READ_INTERLACE + PNG_ASM_FLAG_MMX_READ_FILTER_SUB + PNG_ASM_FLAG_MMX_READ_FILTER_UP + PNG_ASM_FLAG_MMX_READ_FILTER_AVG + PNG_ASM_FLAG_MMX_READ_FILTER_PAETH + PNG_ASM_FLAGS_INITIALIZED + PNG_MMX_READ_FLAGS + PNG_MMX_FLAGS + PNG_MMX_WRITE_FLAGS + PNG_MMX_FLAGS + +We added the following functions in support of runtime +selection of assembler code features: + + png_get_mmx_flagmask() + png_set_mmx_thresholds() + png_get_asm_flags() + png_get_mmx_bitdepth_threshold() + png_get_mmx_rowbytes_threshold() + png_set_asm_flags() + +We replaced all of these functions with simple stubs in libpng-1.2.20, +when the Intel assembler code was removed due to a licensing issue. + +These macros are deprecated: + + PNG_READ_TRANSFORMS_NOT_SUPPORTED + PNG_PROGRESSIVE_READ_NOT_SUPPORTED + PNG_NO_SEQUENTIAL_READ_SUPPORTED + PNG_WRITE_TRANSFORMS_NOT_SUPPORTED + PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED + PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED + +They have been replaced, respectively, by: + + PNG_NO_READ_TRANSFORMS + PNG_NO_PROGRESSIVE_READ + PNG_NO_SEQUENTIAL_READ + PNG_NO_WRITE_TRANSFORMS + PNG_NO_READ_ANCILLARY_CHUNKS + PNG_NO_WRITE_ANCILLARY_CHUNKS + +PNG_MAX_UINT was replaced with PNG_UINT_31_MAX. It has been +deprecated since libpng-1.0.16 and libpng-1.2.6. + +The function + png_check_sig(sig, num) +was replaced with + !png_sig_cmp(sig, 0, num) +It has been deprecated since libpng-0.90. + +The function + png_set_gray_1_2_4_to_8() +which also expands tRNS to alpha was replaced with + png_set_expand_gray_1_2_4_to_8() +which does not. It has been deprecated since libpng-1.0.18 and 1.2.9. + +X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x + +Private libpng prototypes and macro definitions were moved from +png.h and pngconf.h into a new pngpriv.h header file. + +Functions png_set_benign_errors(), png_benign_error(), and +png_chunk_benign_error() were added. + +Support for setting the maximum amount of memory that the application +will allocate for reading chunks was added, as a security measure. +The functions png_set_chunk_cache_max() and png_get_chunk_cache_max() +were added to the library. + +We implemented support for I/O states by adding png_ptr member io_state +and functions png_get_io_chunk_name() and png_get_io_state() in pngget.c + +We added PNG_TRANSFORM_GRAY_TO_RGB to the available high-level +input transforms. + +Checking for and reporting of errors in the IHDR chunk is more thorough. + +Support for global arrays was removed, to improve thread safety. + +Some obsolete/deprecated macros and functions have been removed. + +Typecasted NULL definitions such as + #define png_voidp_NULL (png_voidp)NULL +were eliminated. If you used these in your application, just use +NULL instead. + +The png_struct and info_struct members "trans" and "trans_values" were +changed to "trans_alpha" and "trans_color", respectively. + +The obsolete, unused pnggccrd.c and pngvcrd.c files and related makefiles +were removed. + +The PNG_1_0_X and PNG_1_2_X macros were eliminated. + +The PNG_LEGACY_SUPPORTED macro was eliminated. + +Many WIN32_WCE #ifdefs were removed. + +The functions png_read_init(info_ptr), png_write_init(info_ptr), +png_info_init(info_ptr), png_read_destroy(), and png_write_destroy() +have been removed. They have been deprecated since libpng-0.95. + +The png_permit_empty_plte() was removed. It has been deprecated +since libpng-1.0.9. Use png_permit_mng_features() instead. + +We removed the obsolete stub functions png_get_mmx_flagmask(), +png_set_mmx_thresholds(), png_get_asm_flags(), +png_get_mmx_bitdepth_threshold(), png_get_mmx_rowbytes_threshold(), +png_set_asm_flags(), and png_mmx_supported() + +We removed the obsolete png_check_sig(), png_memcpy_check(), and +png_memset_check() functions. Instead use !png_sig_cmp(), memcpy(), +and memset(), respectively. + +The function png_set_gray_1_2_4_to_8() was removed. It has been +deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with +png_set_expand_gray_1_2_4_to_8() because the former function also +expanded any tRNS chunk to an alpha channel. + +Macros for png_get_uint_16, png_get_uint_32, and png_get_int_32 +were added and are used by default instead of the corresponding +functions. Unfortunately, +from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +function) incorrectly returned a value of type png_uint_32. + +We changed the prototype for png_malloc() from + png_malloc(png_structp png_ptr, png_uint_32 size) +to + png_malloc(png_structp png_ptr, png_alloc_size_t size) + +This also applies to the prototype for the user replacement malloc_fn(). + +The png_calloc() function was added and is used in place of +of "png_malloc(); memset();" except in the case in png_read_png() +where the array consists of pointers; in this case a "for" loop is used +after the png_malloc() to set the pointers to NULL, to give robust. +behavior in case the application runs out of memory part-way through +the process. + +We changed the prototypes of png_get_compression_buffer_size() and +png_set_compression_buffer_size() to work with size_t instead of +png_uint_32. + +Support for numbered error messages was removed by default, since we +never got around to actually numbering the error messages. The function +png_set_strip_error_numbers() was removed from the library by default. + +The png_zalloc() and png_zfree() functions are no longer exported. +The png_zalloc() function no longer zeroes out the memory that it +allocates. Applications that called png_zalloc(png_ptr, number, size) +can call png_calloc(png_ptr, number*size) instead, and can call +png_free() instead of png_zfree(). + +Support for dithering was disabled by default in libpng-1.4.0, because +it has not been well tested and doesn't actually "dither". +The code was not +removed, however, and could be enabled by building libpng with +PNG_READ_DITHER_SUPPORTED defined. In libpng-1.4.2, this support +was re-enabled, but the function was renamed png_set_quantize() to +reflect more accurately what it actually does. At the same time, +the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros were also renamed to +PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS, and PNG_READ_DITHER_SUPPORTED +was renamed to PNG_READ_QUANTIZE_SUPPORTED. + +We removed the trailing '.' from the warning and error messages. + +XI. Changes to Libpng from version 1.4.x to 1.5.x + +From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +function) incorrectly returned a value of type png_uint_32. +The incorrect macro was removed from libpng-1.4.5. + +Checking for invalid palette index on write was added at libpng +1.5.10. If a pixel contains an invalid (out-of-range) index libpng issues +a benign error. This is enabled by default because this condition is an +error according to the PNG specification, Clause 11.3.2, but the error can +be ignored in each png_ptr with + + png_set_check_for_invalid_index(png_ptr, allowed); + + allowed - one of + 0: disable benign error (accept the + invalid data without warning). + 1: enable benign error (treat the + invalid data as an error or a + warning). + +If the error is ignored, or if png_benign_error() treats it as a warning, +any invalid pixels are decoded as opaque black by the decoder and written +as-is by the encoder. + +Retrieving the maximum palette index found was added at libpng-1.5.15. +This statement must appear after png_read_png() or png_read_image() while +reading, and after png_write_png() or png_write_image() while writing. + + int max_palette = png_get_palette_max(png_ptr, info_ptr); + +This will return the maximum palette index found in the image, or "-1" if +the palette was not checked, or "0" if no palette was found. Note that this +does not account for any palette index used by ancillary chunks such as the +bKGD chunk; you must check those separately to determine the maximum +palette index actually used. + +There are no substantial API changes between the non-deprecated parts of +the 1.4.5 API and the 1.5.0 API; however, the ability to directly access +members of the main libpng control structures, png_struct and png_info, +deprecated in earlier versions of libpng, has been completely removed from +libpng 1.5, and new private "pngstruct.h", "pnginfo.h", and "pngdebug.h" +header files were created. + +We no longer include zlib.h in png.h. The include statement has been moved +to pngstruct.h, where it is not accessible by applications. Applications that +need access to information in zlib.h will need to add the '#include "zlib.h"' +directive. It does not matter whether this is placed prior to or after +the '"#include png.h"' directive. + +The png_sprintf(), png_strcpy(), and png_strncpy() macros are no longer used +and were removed. + +We moved the png_strlen(), png_memcpy(), png_memset(), and png_memcmp() +macros into a private header file (pngpriv.h) that is not accessible to +applications. + +In png_get_iCCP, the type of "profile" was changed from png_charpp +to png_bytepp, and in png_set_iCCP, from png_charp to png_const_bytep. + +There are changes of form in png.h, including new and changed macros to +declare parts of the API. Some API functions with arguments that are +pointers to data not modified within the function have been corrected to +declare these arguments with const. + +Much of the internal use of C macros to control the library build has also +changed and some of this is visible in the exported header files, in +particular the use of macros to control data and API elements visible +during application compilation may require significant revision to +application code. (It is extremely rare for an application to do this.) + +Any program that compiled against libpng 1.4 and did not use deprecated +features or access internal library structures should compile and work +against libpng 1.5, except for the change in the prototype for +png_get_iCCP() and png_set_iCCP() API functions mentioned above. + +libpng 1.5.0 adds PNG_ PASS macros to help in the reading and writing of +interlaced images. The macros return the number of rows and columns in +each pass and information that can be used to de-interlace and (if +absolutely necessary) interlace an image. + +libpng 1.5.0 adds an API png_longjmp(png_ptr, value). This API calls +the application-provided png_longjmp_ptr on the internal, but application +initialized, longjmp buffer. It is provided as a convenience to avoid +the need to use the png_jmpbuf macro, which had the unnecessary side +effect of resetting the internal png_longjmp_ptr value. + +libpng 1.5.0 includes a complete fixed point API. By default this is +present along with the corresponding floating point API. In general the +fixed point API is faster and smaller than the floating point one because +the PNG file format used fixed point, not floating point. This applies +even if the library uses floating point in internal calculations. A new +macro, PNG_FLOATING_ARITHMETIC_SUPPORTED, reveals whether the library +uses floating point arithmetic (the default) or fixed point arithmetic +internally for performance critical calculations such as gamma correction. +In some cases, the gamma calculations may produce slightly different +results. This has changed the results in png_rgb_to_gray and in alpha +composition (png_set_background for example). This applies even if the +original image was already linear (gamma == 1.0) and, therefore, it is +not necessary to linearize the image. This is because libpng has *not* +been changed to optimize that case correctly, yet. + +Fixed point support for the sCAL chunk comes with an important caveat; +the sCAL specification uses a decimal encoding of floating point values +and the accuracy of PNG fixed point values is insufficient for +representation of these values. Consequently a "string" API +(png_get_sCAL_s and png_set_sCAL_s) is the only reliable way of reading +arbitrary sCAL chunks in the absence of either the floating point API or +internal floating point calculations. Starting with libpng-1.5.0, both +of these functions are present when PNG_sCAL_SUPPORTED is defined. Prior +to libpng-1.5.0, their presence also depended upon PNG_FIXED_POINT_SUPPORTED +being defined and PNG_FLOATING_POINT_SUPPORTED not being defined. + +Applications no longer need to include the optional distribution header +file pngusr.h or define the corresponding macros during application +build in order to see the correct variant of the libpng API. From 1.5.0 +application code can check for the corresponding _SUPPORTED macro: + +#ifdef PNG_INCH_CONVERSIONS_SUPPORTED + /* code that uses the inch conversion APIs. */ +#endif + +This macro will only be defined if the inch conversion functions have been +compiled into libpng. The full set of macros, and whether or not support +has been compiled in, are available in the header file pnglibconf.h. +This header file is specific to the libpng build. Notice that prior to +1.5.0 the _SUPPORTED macros would always have the default definition unless +reset by pngusr.h or by explicit settings on the compiler command line. +These settings may produce compiler warnings or errors in 1.5.0 because +of macro redefinition. + +Applications can now choose whether to use these macros or to call the +corresponding function by defining PNG_USE_READ_MACROS or +PNG_NO_USE_READ_MACROS before including png.h. Notice that this is +only supported from 1.5.0; defining PNG_NO_USE_READ_MACROS prior to 1.5.0 +will lead to a link failure. + +Prior to libpng-1.5.4, the zlib compressor used the same set of parameters +when compressing the IDAT data and textual data such as zTXt and iCCP. +In libpng-1.5.4 we reinitialized the zlib stream for each type of data. +We added five png_set_text_*() functions for setting the parameters to +use with textual data. + +Prior to libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED +option was off by default, and slightly inaccurate scaling occurred. +This option can no longer be turned off, and the choice of accurate +or inaccurate 16-to-8 scaling is by using the new png_set_scale_16_to_8() +API for accurate scaling or the old png_set_strip_16_to_8() API for simple +chopping. In libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED +macro became PNG_READ_SCALE_16_TO_8_SUPPORTED, and the PNG_READ_16_TO_8 +macro became PNG_READ_STRIP_16_TO_8_SUPPORTED, to enable the two +png_set_*_16_to_8() functions separately. + +Prior to libpng-1.5.4, the png_set_user_limits() function could only be +used to reduce the width and height limits from the value of +PNG_USER_WIDTH_MAX and PNG_USER_HEIGHT_MAX, although this document said +that it could be used to override them. Now this function will reduce or +increase the limits. + +Starting in libpng-1.5.22, default user limits were established. These +can be overridden by application calls to png_set_user_limits(), +png_set_user_chunk_cache_max(), and/or png_set_user_malloc_max(). +The limits are now + max possible default + png_user_width_max 0x7fffffff 1,000,000 + png_user_height_max 0x7fffffff 1,000,000 + png_user_chunk_cache_max 0 (unlimited) 1000 + png_user_chunk_malloc_max 0 (unlimited) 8,000,000 + +The png_set_option() function (and the "options" member of the png struct) was +added to libpng-1.5.15, with option PNG_ARM_NEON. + +The library now supports a complete fixed point implementation and can +thus be used on systems that have no floating point support or very +limited or slow support. Previously gamma correction, an essential part +of complete PNG support, required reasonably fast floating point. + +As part of this the choice of internal implementation has been made +independent of the choice of fixed versus floating point APIs and all the +missing fixed point APIs have been implemented. + +The exact mechanism used to control attributes of API functions has +changed, as described in the INSTALL file. + +A new test program, pngvalid, is provided in addition to pngtest. +pngvalid validates the arithmetic accuracy of the gamma correction +calculations and includes a number of validations of the file format. +A subset of the full range of tests is run when "make check" is done +(in the 'configure' build.) pngvalid also allows total allocated memory +usage to be evaluated and performs additional memory overwrite validation. + +Many changes to individual feature macros have been made. The following +are the changes most likely to be noticed by library builders who +configure libpng: + +1) All feature macros now have consistent naming: + +#define PNG_NO_feature turns the feature off +#define PNG_feature_SUPPORTED turns the feature on + +pnglibconf.h contains one line for each feature macro which is either: + +#define PNG_feature_SUPPORTED + +if the feature is supported or: + +/*#undef PNG_feature_SUPPORTED*/ + +if it is not. Library code consistently checks for the 'SUPPORTED' macro. +It does not, and libpng applications should not, check for the 'NO' macro +which will not normally be defined even if the feature is not supported. +The 'NO' macros are only used internally for setting or not setting the +corresponding 'SUPPORTED' macros. + +Compatibility with the old names is provided as follows: + +PNG_INCH_CONVERSIONS turns on PNG_INCH_CONVERSIONS_SUPPORTED + +And the following definitions disable the corresponding feature: + +PNG_SETJMP_NOT_SUPPORTED disables SETJMP +PNG_READ_TRANSFORMS_NOT_SUPPORTED disables READ_TRANSFORMS +PNG_NO_READ_COMPOSITED_NODIV disables READ_COMPOSITE_NODIV +PNG_WRITE_TRANSFORMS_NOT_SUPPORTED disables WRITE_TRANSFORMS +PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED disables READ_ANCILLARY_CHUNKS +PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED disables WRITE_ANCILLARY_CHUNKS + +Library builders should remove use of the above, inconsistent, names. + +2) Warning and error message formatting was previously conditional on +the STDIO feature. The library has been changed to use the +CONSOLE_IO feature instead. This means that if CONSOLE_IO is disabled +the library no longer uses the printf(3) functions, even though the +default read/write implementations use (FILE) style stdio.h functions. + +3) Three feature macros now control the fixed/floating point decisions: + +PNG_FLOATING_POINT_SUPPORTED enables the floating point APIs + +PNG_FIXED_POINT_SUPPORTED enables the fixed point APIs; however, in +practice these are normally required internally anyway (because the PNG +file format is fixed point), therefore in most cases PNG_NO_FIXED_POINT +merely stops the function from being exported. + +PNG_FLOATING_ARITHMETIC_SUPPORTED chooses between the internal floating +point implementation or the fixed point one. Typically the fixed point +implementation is larger and slower than the floating point implementation +on a system that supports floating point; however, it may be faster on a +system which lacks floating point hardware and therefore uses a software +emulation. + +4) Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED. This allows the +functions to read and write ints to be disabled independently of +PNG_USE_READ_MACROS, which allows libpng to be built with the functions +even though the default is to use the macros - this allows applications +to choose at app buildtime whether or not to use macros (previously +impossible because the functions weren't in the default build.) + +XII. Changes to Libpng from version 1.5.x to 1.6.x + +A "simplified API" has been added (see documentation in png.h and a simple +example in contrib/examples/pngtopng.c). The new publicly visible API +includes the following: + + macros: + PNG_FORMAT_* + PNG_IMAGE_* + structures: + png_control + png_image + read functions + png_image_begin_read_from_file() + png_image_begin_read_from_stdio() + png_image_begin_read_from_memory() + png_image_finish_read() + png_image_free() + write functions + png_image_write_to_file() + png_image_write_to_memory() + png_image_write_to_stdio() + +Starting with libpng-1.6.0, you can configure libpng to prefix all exported +symbols, using the PNG_PREFIX macro. + +We no longer include string.h in png.h. The include statement has been moved +to pngpriv.h, where it is not accessible by applications. Applications that +need access to information in string.h must add an '#include <string.h>' +directive. It does not matter whether this is placed prior to or after +the '#include "png.h"' directive. + +The following API are now DEPRECATED: + png_info_init_3() + png_convert_to_rfc1123() which has been replaced + with png_convert_to_rfc1123_buffer() + png_malloc_default() + png_free_default() + png_reset_zstream() + +The following have been removed: + png_get_io_chunk_name(), which has been replaced + with png_get_io_chunk_type(). The new + function returns a 32-bit integer instead of + a string. + The png_sizeof(), png_strlen(), png_memcpy(), png_memcmp(), and + png_memset() macros are no longer used in the libpng sources and + have been removed. These had already been made invisible to applications + (i.e., defined in the private pngpriv.h header file) since libpng-1.5.0. + +The signatures of many exported functions were changed, such that + png_structp became png_structrp or png_const_structrp + png_infop became png_inforp or png_const_inforp +where "rp" indicates a "restricted pointer". + +Dropped support for 16-bit platforms. The support for FAR/far types has +been eliminated and the definition of png_alloc_size_t is now controlled +by a flag so that 'small size_t' systems can select it if necessary. + +Error detection in some chunks has improved; in particular the iCCP chunk +reader now does pretty complete validation of the basic format. Some bad +profiles that were previously accepted are now accepted with a warning or +rejected, depending upon the png_set_benign_errors() setting, in particular +the very old broken Microsoft/HP 3144-byte sRGB profile. Starting with +libpng-1.6.11, recognizing and checking sRGB profiles can be avoided by +means of + + #if defined(PNG_SKIP_sRGB_CHECK_PROFILE) && \ + defined(PNG_SET_OPTION_SUPPORTED) + png_set_option(png_ptr, PNG_SKIP_sRGB_CHECK_PROFILE, + PNG_OPTION_ON); + #endif + +It's not a good idea to do this if you are using the "simplified API", +which needs to be able to recognize sRGB profiles conveyed via the iCCP +chunk. + +The PNG spec requirement that only grayscale profiles may appear in images +with color type 0 or 4 and that even if the image only contains gray pixels, +only RGB profiles may appear in images with color type 2, 3, or 6, is now +enforced. The sRGB chunk is allowed to appear in images with any color type +and is interpreted by libpng to convey a one-tracer-curve gray profile or a +three-tracer-curve RGB profile as appropriate. + +Libpng 1.5.x erroneously used /MD for Debug DLL builds; if you used the debug +builds in your app and you changed your app to use /MD you will need to +change it back to /MDd for libpng 1.6.x. + +Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained +an empty language field or an empty translated keyword. Both of these +are allowed by the PNG specification, so these warnings are no longer issued. + +The library now issues an error if the application attempts to set a +transform after it calls png_read_update_info() or if it attempts to call +both png_read_update_info() and png_start_read_image() or to call either +of them more than once. + +The default condition for benign_errors is now to treat benign errors as +warnings while reading and as errors while writing. + +The library now issues a warning if both background processing and RGB to +gray are used when gamma correction happens. As with previous versions of +the library the results are numerically very incorrect in this case. + +There are some minor arithmetic changes in some transforms such as +png_set_background(), that might be detected by certain regression tests. + +Unknown chunk handling has been improved internally, without any API change. +This adds more correct option control of the unknown handling, corrects +a pre-existing bug where the per-chunk 'keep' setting is ignored, and makes +it possible to skip IDAT chunks in the sequential reader. + +The machine-generated configure files are no longer included in branches +libpng16 and later of the GIT repository. They continue to be included +in the tarball releases, however. + +Libpng-1.6.0 through 1.6.2 used the CMF bytes at the beginning of the IDAT +stream to set the size of the sliding window for reading instead of using the +default 32-kbyte sliding window size. It was discovered that there are +hundreds of PNG files in the wild that have incorrect CMF bytes that caused +zlib to issue the "invalid distance too far back" error and reject the file. +Libpng-1.6.3 and later calculate their own safe CMF from the image dimensions, +provide a way to revert to the libpng-1.5.x behavior (ignoring the CMF bytes +and using a 32-kbyte sliding window), by using + + png_set_option(png_ptr, PNG_MAXIMUM_INFLATE_WINDOW, + PNG_OPTION_ON); + +and provide a tool (contrib/tools/pngfix) for rewriting a PNG file while +optimizing the CMF bytes in its IDAT chunk correctly. + +Libpng-1.6.0 and libpng-1.6.1 wrote uncompressed iTXt chunks with the wrong +length, which resulted in PNG files that cannot be read beyond the bad iTXt +chunk. This error was fixed in libpng-1.6.3, and a tool (called +contrib/tools/png-fix-itxt) has been added to the libpng distribution. + +Starting with libpng-1.6.17, the PNG_SAFE_LIMITS macro was eliminated +and safe limits are used by default (users who need larger limits +can still override them at compile time or run time, as described above). + +The new limits are + default spec limit + png_user_width_max 1,000,000 2,147,483,647 + png_user_height_max 1,000,000 2,147,483,647 + png_user_chunk_cache_max 128 unlimited + png_user_chunk_malloc_max 8,000,000 unlimited + +Starting with libpng-1.6.18, a PNG_RELEASE_BUILD macro was added, which allows +library builders to control compilation for an installed system (a release build). +It can be set for testing debug or beta builds to ensure that they will compile +when the build type is switched to RC or STABLE. In essence this overrides the +PNG_LIBPNG_BUILD_BASE_TYPE definition which is not directly user controllable. + +Starting with libpng-1.6.19, attempting to set an over-length PLTE chunk +is an error. Previously this requirement of the PNG specification was not +enforced, and the palette was always limited to 256 entries. An over-length +PLTE chunk found in an input PNG is silently truncated. + +Starting with libpng-1.6.31, the eXIf chunk is supported. Libpng does not +attempt to decode the Exif profile; it simply returns a byte array +containing the profile to the calling application which must do its own +decoding. + +XIII. Detecting libpng + +The png_get_io_ptr() function has been present since libpng-0.88, has never +changed, and is unaffected by conditional compilation macros. It is the +best choice for use in configure scripts for detecting the presence of any +libpng version since 0.88. In an autoconf "configure.in" you could use + + AC_CHECK_LIB(png, png_get_io_ptr, ... + +XV. Source code repository + +Since about February 2009, version 1.2.34, libpng has been under "git" source +control. The git repository was built from old libpng-x.y.z.tar.gz files +going back to version 0.70. You can access the git repository (read only) +at + + https://github.com/glennrp/libpng or + https://git.code.sf.net/p/libpng/code.git + +or you can browse it with a web browser at + + https://github.com/glennrp/libpng or + https://sourceforge.net/p/libpng/code/ci/libpng16/tree/ + +Patches can be sent to png-mng-implement at lists.sourceforge.net or +uploaded to the libpng bug tracker at + + https://libpng.sourceforge.io/ + +or as a "pull request" to + + https://github.com/glennrp/libpng/pulls + +We also accept patches built from the tar or zip distributions, and +simple verbal descriptions of bug fixes, reported either to the +SourceForge bug tracker, to the png-mng-implement at lists.sf.net +mailing list, as github issues. + +XV. Coding style + +Our coding style is similar to the "Allman" style +(See https://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly +braces on separate lines: + + if (condition) + { + action; + } + + else if (another condition) + { + another action; + } + +The braces can be omitted from simple one-line actions: + + if (condition) + return 0; + +We use 3-space indentation, except for continued statements which +are usually indented the same as the first line of the statement +plus four more spaces. + +For macro definitions we use 2-space indentation, always leaving the "#" +in the first column. + + #ifndef PNG_NO_FEATURE + # ifndef PNG_FEATURE_SUPPORTED + # define PNG_FEATURE_SUPPORTED + # endif + #endif + +Comments appear with the leading "/*" at the same indentation as +the statement that follows the comment: + + /* Single-line comment */ + statement; + + /* This is a multiple-line + * comment. + */ + statement; + +Very short comments can be placed after the end of the statement +to which they pertain: + + statement; /* comment */ + +We don't use C++ style ("//") comments. We have, however, +used them in the past in some now-abandoned MMX assembler +code. + +Functions and their curly braces are not indented, and +exported functions are marked with PNGAPI: + + /* This is a public function that is visible to + * application programmers. It does thus-and-so. + */ + void PNGAPI + png_exported_function(png_ptr, png_info, foo) + { + body; + } + +The return type and decorations are placed on a separate line +ahead of the function name, as illustrated above. + +The prototypes for all exported functions appear in png.h, +above the comment that says + + /* Maintainer: Put new public prototypes here ... */ + +We mark all non-exported functions with "/* PRIVATE */"": + + void /* PRIVATE */ + png_non_exported_function(png_ptr, png_info, foo) + { + body; + } + +The prototypes for non-exported functions (except for those in +pngtest) appear in pngpriv.h above the comment that says + + /* Maintainer: Put new private prototypes here ^ */ + +To avoid polluting the global namespace, the names of all exported +functions and variables begin with "png_", and all publicly visible C +preprocessor macros begin with "PNG". We request that applications that +use libpng *not* begin any of their own symbols with either of these strings. + +We put a space after the "sizeof" operator and we omit the +optional parentheses around its argument when the argument +is an expression, not a type name, and we always enclose the +sizeof operator, with its argument, in parentheses: + + (sizeof (png_uint_32)) + (sizeof array) + +Prior to libpng-1.6.0 we used a "png_sizeof()" macro, formatted as +though it were a function. + +Control keywords if, for, while, and switch are always followed by a space +to distinguish them from function calls, which have no trailing space. + +We put a space after each comma and after each semicolon +in "for" statements, and we put spaces before and after each +C binary operator and after "for" or "while", and before +"?". We don't put a space between a typecast and the expression +being cast, nor do we put one between a function name and the +left parenthesis that follows it: + + for (i = 2; i > 0; --i) + y[i] = a(x) + (int)b; + +We prefer #ifdef and #ifndef to #if defined() and #if !defined() +when there is only one macro being tested. We always use parentheses +with "defined". + +We express integer constants that are used as bit masks in hex format, +with an even number of lower-case hex digits, and to make them unsigned +(e.g., 0x00U, 0xffU, 0x0100U) and long if they are greater than 0x7fff +(e.g., 0xffffUL). + +We prefer to use underscores rather than camelCase in names, except +for a few type names that we inherit from zlib.h. + +We prefer "if (something != 0)" and "if (something == 0)" over +"if (something)" and if "(!something)", respectively, and for pointers +we prefer "if (some_pointer != NULL)" or "if (some_pointer == NULL)". + +We do not use the TAB character for indentation in the C sources. + +Lines do not exceed 80 characters. + +Other rules can be inferred by inspecting the libpng source. diff --git a/media/libpng/mips/filter_msa_intrinsics.c b/media/libpng/mips/filter_msa_intrinsics.c new file mode 100644 index 0000000000..a579179421 --- /dev/null +++ b/media/libpng/mips/filter_msa_intrinsics.c @@ -0,0 +1,808 @@ + +/* filter_msa_intrinsics.c - MSA optimised filter functions + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 2016 Glenn Randers-Pehrson + * Written by Mandar Sahastrabuddhe, August 2016. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include <stdio.h> +#include <stdint.h> +#include "../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +/* This code requires -mfpu=msa on the command line: */ +#if PNG_MIPS_MSA_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */ + +#include <msa.h> + +/* libpng row pointers are not necessarily aligned to any particular boundary, + * however this code will only work with appropriate alignment. mips/mips_init.c + * checks for this (and will not compile unless it is done). This code uses + * variants of png_aligncast to avoid compiler warnings. + */ +#define png_ptr(type,pointer) png_aligncast(type *,pointer) +#define png_ptrc(type,pointer) png_aligncastconst(const type *,pointer) + +/* The following relies on a variable 'temp_pointer' being declared with type + * 'type'. This is written this way just to hide the GCC strict aliasing + * warning; note that the code is safe because there never is an alias between + * the input and output pointers. + */ +#define png_ldr(type,pointer)\ + (temp_pointer = png_ptr(type,pointer), *temp_pointer) + +#if PNG_MIPS_MSA_OPT > 0 + +#ifdef CLANG_BUILD + #define MSA_SRLI_B(a, b) __msa_srli_b((v16i8) a, b) + + #define LW(psrc) \ + ( { \ + uint8_t *psrc_lw_m = (uint8_t *) (psrc); \ + uint32_t val_m; \ + \ + asm volatile ( \ + "lw %[val_m], %[psrc_lw_m] \n\t" \ + \ + : [val_m] "=r" (val_m) \ + : [psrc_lw_m] "m" (*psrc_lw_m) \ + ); \ + \ + val_m; \ + } ) + + #define SH(val, pdst) \ + { \ + uint8_t *pdst_sh_m = (uint8_t *) (pdst); \ + uint16_t val_m = (val); \ + \ + asm volatile ( \ + "sh %[val_m], %[pdst_sh_m] \n\t" \ + \ + : [pdst_sh_m] "=m" (*pdst_sh_m) \ + : [val_m] "r" (val_m) \ + ); \ + } + + #define SW(val, pdst) \ + { \ + uint8_t *pdst_sw_m = (uint8_t *) (pdst); \ + uint32_t val_m = (val); \ + \ + asm volatile ( \ + "sw %[val_m], %[pdst_sw_m] \n\t" \ + \ + : [pdst_sw_m] "=m" (*pdst_sw_m) \ + : [val_m] "r" (val_m) \ + ); \ + } + + #if (__mips == 64) + #define SD(val, pdst) \ + { \ + uint8_t *pdst_sd_m = (uint8_t *) (pdst); \ + uint64_t val_m = (val); \ + \ + asm volatile ( \ + "sd %[val_m], %[pdst_sd_m] \n\t" \ + \ + : [pdst_sd_m] "=m" (*pdst_sd_m) \ + : [val_m] "r" (val_m) \ + ); \ + } + #else + #define SD(val, pdst) \ + { \ + uint8_t *pdst_sd_m = (uint8_t *) (pdst); \ + uint32_t val0_m, val1_m; \ + \ + val0_m = (uint32_t) ((val) & 0x00000000FFFFFFFF); \ + val1_m = (uint32_t) (((val) >> 32) & 0x00000000FFFFFFFF); \ + \ + SW(val0_m, pdst_sd_m); \ + SW(val1_m, pdst_sd_m + 4); \ + } + #endif +#else + #define MSA_SRLI_B(a, b) (a >> b) + +#if (__mips_isa_rev >= 6) + #define LW(psrc) \ + ( { \ + uint8_t *psrc_lw_m = (uint8_t *) (psrc); \ + uint32_t val_m; \ + \ + asm volatile ( \ + "lw %[val_m], %[psrc_lw_m] \n\t" \ + \ + : [val_m] "=r" (val_m) \ + : [psrc_lw_m] "m" (*psrc_lw_m) \ + ); \ + \ + val_m; \ + } ) + + #define SH(val, pdst) \ + { \ + uint8_t *pdst_sh_m = (uint8_t *) (pdst); \ + uint16_t val_m = (val); \ + \ + asm volatile ( \ + "sh %[val_m], %[pdst_sh_m] \n\t" \ + \ + : [pdst_sh_m] "=m" (*pdst_sh_m) \ + : [val_m] "r" (val_m) \ + ); \ + } + + #define SW(val, pdst) \ + { \ + uint8_t *pdst_sw_m = (uint8_t *) (pdst); \ + uint32_t val_m = (val); \ + \ + asm volatile ( \ + "sw %[val_m], %[pdst_sw_m] \n\t" \ + \ + : [pdst_sw_m] "=m" (*pdst_sw_m) \ + : [val_m] "r" (val_m) \ + ); \ + } + + #if (__mips == 64) + #define SD(val, pdst) \ + { \ + uint8_t *pdst_sd_m = (uint8_t *) (pdst); \ + uint64_t val_m = (val); \ + \ + asm volatile ( \ + "sd %[val_m], %[pdst_sd_m] \n\t" \ + \ + : [pdst_sd_m] "=m" (*pdst_sd_m) \ + : [val_m] "r" (val_m) \ + ); \ + } + #else + #define SD(val, pdst) \ + { \ + uint8_t *pdst_sd_m = (uint8_t *) (pdst); \ + uint32_t val0_m, val1_m; \ + \ + val0_m = (uint32_t) ((val) & 0x00000000FFFFFFFF); \ + val1_m = (uint32_t) (((val) >> 32) & 0x00000000FFFFFFFF); \ + \ + SW(val0_m, pdst_sd_m); \ + SW(val1_m, pdst_sd_m + 4); \ + } + #endif +#else // !(__mips_isa_rev >= 6) + #define LW(psrc) \ + ( { \ + uint8_t *psrc_lw_m = (uint8_t *) (psrc); \ + uint32_t val_m; \ + \ + asm volatile ( \ + "ulw %[val_m], %[psrc_lw_m] \n\t" \ + \ + : [val_m] "=r" (val_m) \ + : [psrc_lw_m] "m" (*psrc_lw_m) \ + ); \ + \ + val_m; \ + } ) + + #define SH(val, pdst) \ + { \ + uint8_t *pdst_sh_m = (uint8_t *) (pdst); \ + uint16_t val_m = (val); \ + \ + asm volatile ( \ + "ush %[val_m], %[pdst_sh_m] \n\t" \ + \ + : [pdst_sh_m] "=m" (*pdst_sh_m) \ + : [val_m] "r" (val_m) \ + ); \ + } + + #define SW(val, pdst) \ + { \ + uint8_t *pdst_sw_m = (uint8_t *) (pdst); \ + uint32_t val_m = (val); \ + \ + asm volatile ( \ + "usw %[val_m], %[pdst_sw_m] \n\t" \ + \ + : [pdst_sw_m] "=m" (*pdst_sw_m) \ + : [val_m] "r" (val_m) \ + ); \ + } + + #define SD(val, pdst) \ + { \ + uint8_t *pdst_sd_m = (uint8_t *) (pdst); \ + uint32_t val0_m, val1_m; \ + \ + val0_m = (uint32_t) ((val) & 0x00000000FFFFFFFF); \ + val1_m = (uint32_t) (((val) >> 32) & 0x00000000FFFFFFFF); \ + \ + SW(val0_m, pdst_sd_m); \ + SW(val1_m, pdst_sd_m + 4); \ + } + + #define SW_ZERO(pdst) \ + { \ + uint8_t *pdst_m = (uint8_t *) (pdst); \ + \ + asm volatile ( \ + "usw $0, %[pdst_m] \n\t" \ + \ + : [pdst_m] "=m" (*pdst_m) \ + : \ + ); \ + } +#endif // (__mips_isa_rev >= 6) +#endif + +#define LD_B(RTYPE, psrc) *((RTYPE *) (psrc)) +#define LD_UB(...) LD_B(v16u8, __VA_ARGS__) +#define LD_B2(RTYPE, psrc, stride, out0, out1) \ +{ \ + out0 = LD_B(RTYPE, (psrc)); \ + out1 = LD_B(RTYPE, (psrc) + stride); \ +} +#define LD_UB2(...) LD_B2(v16u8, __VA_ARGS__) +#define LD_B4(RTYPE, psrc, stride, out0, out1, out2, out3) \ +{ \ + LD_B2(RTYPE, (psrc), stride, out0, out1); \ + LD_B2(RTYPE, (psrc) + 2 * stride , stride, out2, out3); \ +} +#define LD_UB4(...) LD_B4(v16u8, __VA_ARGS__) + +#define ST_B(RTYPE, in, pdst) *((RTYPE *) (pdst)) = (in) +#define ST_UB(...) ST_B(v16u8, __VA_ARGS__) +#define ST_B2(RTYPE, in0, in1, pdst, stride) \ +{ \ + ST_B(RTYPE, in0, (pdst)); \ + ST_B(RTYPE, in1, (pdst) + stride); \ +} +#define ST_UB2(...) ST_B2(v16u8, __VA_ARGS__) +#define ST_B4(RTYPE, in0, in1, in2, in3, pdst, stride) \ +{ \ + ST_B2(RTYPE, in0, in1, (pdst), stride); \ + ST_B2(RTYPE, in2, in3, (pdst) + 2 * stride, stride); \ +} +#define ST_UB4(...) ST_B4(v16u8, __VA_ARGS__) + +#define ADD2(in0, in1, in2, in3, out0, out1) \ +{ \ + out0 = in0 + in1; \ + out1 = in2 + in3; \ +} +#define ADD3(in0, in1, in2, in3, in4, in5, \ + out0, out1, out2) \ +{ \ + ADD2(in0, in1, in2, in3, out0, out1); \ + out2 = in4 + in5; \ +} +#define ADD4(in0, in1, in2, in3, in4, in5, in6, in7, \ + out0, out1, out2, out3) \ +{ \ + ADD2(in0, in1, in2, in3, out0, out1); \ + ADD2(in4, in5, in6, in7, out2, out3); \ +} + +#define ILVR_B2(RTYPE, in0, in1, in2, in3, out0, out1) \ +{ \ + out0 = (RTYPE) __msa_ilvr_b((v16i8) in0, (v16i8) in1); \ + out1 = (RTYPE) __msa_ilvr_b((v16i8) in2, (v16i8) in3); \ +} +#define ILVR_B2_SH(...) ILVR_B2(v8i16, __VA_ARGS__) + +#define HSUB_UB2(RTYPE, in0, in1, out0, out1) \ +{ \ + out0 = (RTYPE) __msa_hsub_u_h((v16u8) in0, (v16u8) in0); \ + out1 = (RTYPE) __msa_hsub_u_h((v16u8) in1, (v16u8) in1); \ +} +#define HSUB_UB2_SH(...) HSUB_UB2(v8i16, __VA_ARGS__) + +#define SLDI_B2_0(RTYPE, in0, in1, out0, out1, slide_val) \ +{ \ + v16i8 zero_m = { 0 }; \ + out0 = (RTYPE) __msa_sldi_b((v16i8) zero_m, (v16i8) in0, slide_val); \ + out1 = (RTYPE) __msa_sldi_b((v16i8) zero_m, (v16i8) in1, slide_val); \ +} +#define SLDI_B2_0_UB(...) SLDI_B2_0(v16u8, __VA_ARGS__) + +#define SLDI_B3_0(RTYPE, in0, in1, in2, out0, out1, out2, slide_val) \ +{ \ + v16i8 zero_m = { 0 }; \ + SLDI_B2_0(RTYPE, in0, in1, out0, out1, slide_val); \ + out2 = (RTYPE) __msa_sldi_b((v16i8) zero_m, (v16i8) in2, slide_val); \ +} +#define SLDI_B3_0_UB(...) SLDI_B3_0(v16u8, __VA_ARGS__) + +#define ILVEV_W2(RTYPE, in0, in1, in2, in3, out0, out1) \ +{ \ + out0 = (RTYPE) __msa_ilvev_w((v4i32) in1, (v4i32) in0); \ + out1 = (RTYPE) __msa_ilvev_w((v4i32) in3, (v4i32) in2); \ +} +#define ILVEV_W2_UB(...) ILVEV_W2(v16u8, __VA_ARGS__) + +#define ADD_ABS_H3(RTYPE, in0, in1, in2, out0, out1, out2) \ +{ \ + RTYPE zero = {0}; \ + \ + out0 = __msa_add_a_h((v8i16) zero, in0); \ + out1 = __msa_add_a_h((v8i16) zero, in1); \ + out2 = __msa_add_a_h((v8i16) zero, in2); \ +} +#define ADD_ABS_H3_SH(...) ADD_ABS_H3(v8i16, __VA_ARGS__) + +#define VSHF_B2(RTYPE, in0, in1, in2, in3, mask0, mask1, out0, out1) \ +{ \ + out0 = (RTYPE) __msa_vshf_b((v16i8) mask0, (v16i8) in1, (v16i8) in0); \ + out1 = (RTYPE) __msa_vshf_b((v16i8) mask1, (v16i8) in3, (v16i8) in2); \ +} +#define VSHF_B2_UB(...) VSHF_B2(v16u8, __VA_ARGS__) + +#define CMP_AND_SELECT(inp0, inp1, inp2, inp3, inp4, inp5, out0) \ +{ \ + v8i16 _sel_h0, _sel_h1; \ + v16u8 _sel_b0, _sel_b1; \ + _sel_h0 = (v8i16) __msa_clt_u_h((v8u16) inp1, (v8u16) inp0); \ + _sel_b0 = (v16u8) __msa_pckev_b((v16i8) _sel_h0, (v16i8) _sel_h0); \ + inp0 = (v8i16) __msa_bmnz_v((v16u8) inp0, (v16u8) inp1, (v16u8) _sel_h0); \ + inp4 = (v16u8) __msa_bmnz_v(inp3, inp4, _sel_b0); \ + _sel_h1 = (v8i16) __msa_clt_u_h((v8u16) inp2, (v8u16) inp0); \ + _sel_b1 = (v16u8) __msa_pckev_b((v16i8) _sel_h1, (v16i8) _sel_h1); \ + inp4 = (v16u8) __msa_bmnz_v(inp4, inp5, _sel_b1); \ + out0 += inp4; \ +} + +void png_read_filter_row_up_msa(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + size_t i, cnt, cnt16, cnt32; + size_t istop = row_info->rowbytes; + png_bytep rp = row; + png_const_bytep pp = prev_row; + v16u8 src0, src1, src2, src3, src4, src5, src6, src7; + + for (i = 0; i < (istop >> 6); i++) + { + LD_UB4(rp, 16, src0, src1, src2, src3); + LD_UB4(pp, 16, src4, src5, src6, src7); + pp += 64; + + ADD4(src0, src4, src1, src5, src2, src6, src3, src7, + src0, src1, src2, src3); + + ST_UB4(src0, src1, src2, src3, rp, 16); + rp += 64; + } + + if (istop & 0x3F) + { + cnt32 = istop & 0x20; + cnt16 = istop & 0x10; + cnt = istop & 0xF; + + if(cnt32) + { + if (cnt16 && cnt) + { + LD_UB4(rp, 16, src0, src1, src2, src3); + LD_UB4(pp, 16, src4, src5, src6, src7); + + ADD4(src0, src4, src1, src5, src2, src6, src3, src7, + src0, src1, src2, src3); + + ST_UB4(src0, src1, src2, src3, rp, 16); + rp += 64; + } + else if (cnt16 || cnt) + { + LD_UB2(rp, 16, src0, src1); + LD_UB2(pp, 16, src4, src5); + pp += 32; + src2 = LD_UB(rp + 32); + src6 = LD_UB(pp); + + ADD3(src0, src4, src1, src5, src2, src6, src0, src1, src2); + + ST_UB2(src0, src1, rp, 16); + rp += 32; + ST_UB(src2, rp); + rp += 16; + } + else + { + LD_UB2(rp, 16, src0, src1); + LD_UB2(pp, 16, src4, src5); + + ADD2(src0, src4, src1, src5, src0, src1); + + ST_UB2(src0, src1, rp, 16); + rp += 32; + } + } + else if (cnt16 && cnt) + { + LD_UB2(rp, 16, src0, src1); + LD_UB2(pp, 16, src4, src5); + + ADD2(src0, src4, src1, src5, src0, src1); + + ST_UB2(src0, src1, rp, 16); + rp += 32; + } + else if (cnt16 || cnt) + { + src0 = LD_UB(rp); + src4 = LD_UB(pp); + pp += 16; + + src0 += src4; + + ST_UB(src0, rp); + rp += 16; + } + } +} + +void png_read_filter_row_sub4_msa(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + size_t count; + size_t istop = row_info->rowbytes; + png_bytep src = row; + png_bytep nxt = row + 4; + int32_t inp0; + v16u8 src0, src1, src2, src3, src4; + v16u8 dst0, dst1; + v16u8 zero = { 0 }; + + istop -= 4; + + inp0 = LW(src); + src += 4; + src0 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp0); + + for (count = 0; count < istop; count += 16) + { + src1 = LD_UB(src); + src += 16; + + src2 = (v16u8) __msa_sldi_b((v16i8) zero, (v16i8) src1, 4); + src3 = (v16u8) __msa_sldi_b((v16i8) zero, (v16i8) src1, 8); + src4 = (v16u8) __msa_sldi_b((v16i8) zero, (v16i8) src1, 12); + src1 += src0; + src2 += src1; + src3 += src2; + src4 += src3; + src0 = src4; + ILVEV_W2_UB(src1, src2, src3, src4, dst0, dst1); + dst0 = (v16u8) __msa_pckev_d((v2i64) dst1, (v2i64) dst0); + + ST_UB(dst0, nxt); + nxt += 16; + } +} + +void png_read_filter_row_sub3_msa(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + size_t count; + size_t istop = row_info->rowbytes; + png_bytep src = row; + png_bytep nxt = row + 3; + int64_t out0; + int32_t inp0, out1; + v16u8 src0, src1, src2, src3, src4, dst0, dst1; + v16u8 zero = { 0 }; + v16i8 mask0 = { 0, 1, 2, 16, 17, 18, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; + v16i8 mask1 = { 0, 1, 2, 3, 4, 5, 16, 17, 18, 19, 20, 21, 0, 0, 0, 0 }; + + istop -= 3; + + inp0 = LW(src); + src += 3; + src0 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp0); + + for (count = 0; count < istop; count += 12) + { + src1 = LD_UB(src); + src += 12; + + src2 = (v16u8) __msa_sldi_b((v16i8) zero, (v16i8) src1, 3); + src3 = (v16u8) __msa_sldi_b((v16i8) zero, (v16i8) src1, 6); + src4 = (v16u8) __msa_sldi_b((v16i8) zero, (v16i8) src1, 9); + src1 += src0; + src2 += src1; + src3 += src2; + src4 += src3; + src0 = src4; + VSHF_B2_UB(src1, src2, src3, src4, mask0, mask0, dst0, dst1); + dst0 = (v16u8) __msa_vshf_b(mask1, (v16i8) dst1, (v16i8) dst0); + out0 = __msa_copy_s_d((v2i64) dst0, 0); + out1 = __msa_copy_s_w((v4i32) dst0, 2); + + SD(out0, nxt); + nxt += 8; + SW(out1, nxt); + nxt += 4; + } +} + +void png_read_filter_row_avg4_msa(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + size_t i; + png_bytep src = row; + png_bytep nxt = row; + png_const_bytep pp = prev_row; + size_t istop = row_info->rowbytes - 4; + int32_t inp0, inp1, out0; + v16u8 src0, src1, src2, src3, src4, src5, src6, src7, src8, src9, dst0, dst1; + v16u8 zero = { 0 }; + + inp0 = LW(pp); + pp += 4; + inp1 = LW(src); + src += 4; + src0 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp0); + src1 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp1); + src0 = (v16u8) MSA_SRLI_B(src0, 1); + src1 += src0; + out0 = __msa_copy_s_w((v4i32) src1, 0); + SW(out0, nxt); + nxt += 4; + + for (i = 0; i < istop; i += 16) + { + src2 = LD_UB(pp); + pp += 16; + src6 = LD_UB(src); + src += 16; + + SLDI_B2_0_UB(src2, src6, src3, src7, 4); + SLDI_B2_0_UB(src2, src6, src4, src8, 8); + SLDI_B2_0_UB(src2, src6, src5, src9, 12); + src2 = __msa_ave_u_b(src2, src1); + src6 += src2; + src3 = __msa_ave_u_b(src3, src6); + src7 += src3; + src4 = __msa_ave_u_b(src4, src7); + src8 += src4; + src5 = __msa_ave_u_b(src5, src8); + src9 += src5; + src1 = src9; + ILVEV_W2_UB(src6, src7, src8, src9, dst0, dst1); + dst0 = (v16u8) __msa_pckev_d((v2i64) dst1, (v2i64) dst0); + + ST_UB(dst0, nxt); + nxt += 16; + } +} + +void png_read_filter_row_avg3_msa(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + size_t i; + png_bytep src = row; + png_bytep nxt = row; + png_const_bytep pp = prev_row; + size_t istop = row_info->rowbytes - 3; + int64_t out0; + int32_t inp0, inp1, out1; + int16_t out2; + v16u8 src0, src1, src2, src3, src4, src5, src6, src7, src8, src9, dst0, dst1; + v16u8 zero = { 0 }; + v16i8 mask0 = { 0, 1, 2, 16, 17, 18, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; + v16i8 mask1 = { 0, 1, 2, 3, 4, 5, 16, 17, 18, 19, 20, 21, 0, 0, 0, 0 }; + + inp0 = LW(pp); + pp += 3; + inp1 = LW(src); + src += 3; + src0 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp0); + src1 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp1); + src0 = (v16u8) MSA_SRLI_B(src0, 1); + src1 += src0; + out2 = __msa_copy_s_h((v8i16) src1, 0); + SH(out2, nxt); + nxt += 2; + nxt[0] = src1[2]; + nxt++; + + for (i = 0; i < istop; i += 12) + { + src2 = LD_UB(pp); + pp += 12; + src6 = LD_UB(src); + src += 12; + + SLDI_B2_0_UB(src2, src6, src3, src7, 3); + SLDI_B2_0_UB(src2, src6, src4, src8, 6); + SLDI_B2_0_UB(src2, src6, src5, src9, 9); + src2 = __msa_ave_u_b(src2, src1); + src6 += src2; + src3 = __msa_ave_u_b(src3, src6); + src7 += src3; + src4 = __msa_ave_u_b(src4, src7); + src8 += src4; + src5 = __msa_ave_u_b(src5, src8); + src9 += src5; + src1 = src9; + VSHF_B2_UB(src6, src7, src8, src9, mask0, mask0, dst0, dst1); + dst0 = (v16u8) __msa_vshf_b(mask1, (v16i8) dst1, (v16i8) dst0); + out0 = __msa_copy_s_d((v2i64) dst0, 0); + out1 = __msa_copy_s_w((v4i32) dst0, 2); + + SD(out0, nxt); + nxt += 8; + SW(out1, nxt); + nxt += 4; + } +} + +void png_read_filter_row_paeth4_msa(png_row_infop row_info, + png_bytep row, + png_const_bytep prev_row) +{ + int32_t count, rp_end; + png_bytep nxt; + png_const_bytep prev_nxt; + int32_t inp0, inp1, res0; + v16u8 src0, src1, src2, src3, src4, src5, src6, src7, src8, src9; + v16u8 src10, src11, src12, src13, dst0, dst1; + v8i16 vec0, vec1, vec2; + v16u8 zero = { 0 }; + + nxt = row; + prev_nxt = prev_row; + + inp0 = LW(nxt); + inp1 = LW(prev_nxt); + prev_nxt += 4; + src0 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp0); + src1 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp1); + + src1 += src0; + res0 = __msa_copy_s_w((v4i32) src1, 0); + + SW(res0, nxt); + nxt += 4; + + /* Remainder */ + rp_end = row_info->rowbytes - 4; + + for (count = 0; count < rp_end; count += 16) + { + src2 = LD_UB(prev_nxt); + prev_nxt += 16; + src6 = LD_UB(prev_row); + prev_row += 16; + src10 = LD_UB(nxt); + + SLDI_B3_0_UB(src2, src6, src10, src3, src7, src11, 4); + SLDI_B3_0_UB(src2, src6, src10, src4, src8, src12, 8); + SLDI_B3_0_UB(src2, src6, src10, src5, src9, src13, 12); + ILVR_B2_SH(src2, src6, src1, src6, vec0, vec1); + HSUB_UB2_SH(vec0, vec1, vec0, vec1); + vec2 = vec0 + vec1; + ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2); + CMP_AND_SELECT(vec0, vec1, vec2, src1, src2, src6, src10); + ILVR_B2_SH(src3, src7, src10, src7, vec0, vec1); + HSUB_UB2_SH(vec0, vec1, vec0, vec1); + vec2 = vec0 + vec1; + ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2); + CMP_AND_SELECT(vec0, vec1, vec2, src10, src3, src7, src11); + ILVR_B2_SH(src4, src8, src11, src8, vec0, vec1); + HSUB_UB2_SH(vec0, vec1, vec0, vec1); + vec2 = vec0 + vec1; + ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2); + CMP_AND_SELECT(vec0, vec1, vec2, src11, src4, src8, src12); + ILVR_B2_SH(src5, src9, src12, src9, vec0, vec1); + HSUB_UB2_SH(vec0, vec1, vec0, vec1); + vec2 = vec0 + vec1; + ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2); + CMP_AND_SELECT(vec0, vec1, vec2, src12, src5, src9, src13); + src1 = src13; + ILVEV_W2_UB(src10, src11, src12, src1, dst0, dst1); + dst0 = (v16u8) __msa_pckev_d((v2i64) dst1, (v2i64) dst0); + + ST_UB(dst0, nxt); + nxt += 16; + } +} + +void png_read_filter_row_paeth3_msa(png_row_infop row_info, + png_bytep row, + png_const_bytep prev_row) +{ + int32_t count, rp_end; + png_bytep nxt; + png_const_bytep prev_nxt; + int64_t out0; + int32_t inp0, inp1, out1; + int16_t out2; + v16u8 src0, src1, src2, src3, src4, src5, src6, src7, src8, src9, dst0, dst1; + v16u8 src10, src11, src12, src13; + v8i16 vec0, vec1, vec2; + v16u8 zero = { 0 }; + v16i8 mask0 = { 0, 1, 2, 16, 17, 18, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; + v16i8 mask1 = { 0, 1, 2, 3, 4, 5, 16, 17, 18, 19, 20, 21, 0, 0, 0, 0 }; + + nxt = row; + prev_nxt = prev_row; + + inp0 = LW(nxt); + inp1 = LW(prev_nxt); + prev_nxt += 3; + src0 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp0); + src1 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp1); + + src1 += src0; + out2 = __msa_copy_s_h((v8i16) src1, 0); + + SH(out2, nxt); + nxt += 2; + nxt[0] = src1[2]; + nxt++; + + /* Remainder */ + rp_end = row_info->rowbytes - 3; + + for (count = 0; count < rp_end; count += 12) + { + src2 = LD_UB(prev_nxt); + prev_nxt += 12; + src6 = LD_UB(prev_row); + prev_row += 12; + src10 = LD_UB(nxt); + + SLDI_B3_0_UB(src2, src6, src10, src3, src7, src11, 3); + SLDI_B3_0_UB(src2, src6, src10, src4, src8, src12, 6); + SLDI_B3_0_UB(src2, src6, src10, src5, src9, src13, 9); + ILVR_B2_SH(src2, src6, src1, src6, vec0, vec1); + HSUB_UB2_SH(vec0, vec1, vec0, vec1); + vec2 = vec0 + vec1; + ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2); + CMP_AND_SELECT(vec0, vec1, vec2, src1, src2, src6, src10); + ILVR_B2_SH(src3, src7, src10, src7, vec0, vec1); + HSUB_UB2_SH(vec0, vec1, vec0, vec1); + vec2 = vec0 + vec1; + ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2); + CMP_AND_SELECT(vec0, vec1, vec2, src10, src3, src7, src11); + ILVR_B2_SH(src4, src8, src11, src8, vec0, vec1); + HSUB_UB2_SH(vec0, vec1, vec0, vec1); + vec2 = vec0 + vec1; + ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2); + CMP_AND_SELECT(vec0, vec1, vec2, src11, src4, src8, src12); + ILVR_B2_SH(src5, src9, src12, src9, vec0, vec1); + HSUB_UB2_SH(vec0, vec1, vec0, vec1); + vec2 = vec0 + vec1; + ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2); + CMP_AND_SELECT(vec0, vec1, vec2, src12, src5, src9, src13); + src1 = src13; + VSHF_B2_UB(src10, src11, src12, src13, mask0, mask0, dst0, dst1); + dst0 = (v16u8) __msa_vshf_b(mask1, (v16i8) dst1, (v16i8) dst0); + out0 = __msa_copy_s_d((v2i64) dst0, 0); + out1 = __msa_copy_s_w((v4i32) dst0, 2); + + SD(out0, nxt); + nxt += 8; + SW(out1, nxt); + nxt += 4; + } +} + +#endif /* PNG_MIPS_MSA_OPT > 0 */ +#endif /* PNG_MIPS_MSA_IMPLEMENTATION == 1 (intrinsics) */ +#endif /* READ */ diff --git a/media/libpng/mips/mips_init.c b/media/libpng/mips/mips_init.c new file mode 100644 index 0000000000..8dd283deef --- /dev/null +++ b/media/libpng/mips/mips_init.c @@ -0,0 +1,130 @@ + +/* mips_init.c - MSA optimised filter functions + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 2016 Glenn Randers-Pehrson + * Written by Mandar Sahastrabuddhe, 2016. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are + * called. + */ +#define _POSIX_SOURCE 1 + +#include <stdio.h> +#include "../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +#if PNG_MIPS_MSA_OPT > 0 +#ifdef PNG_MIPS_MSA_CHECK_SUPPORTED /* Do run-time checks */ +/* WARNING: it is strongly recommended that you do not build libpng with + * run-time checks for CPU features if at all possible. In the case of the MIPS + * MSA instructions there is no processor-specific way of detecting the + * presence of the required support, therefore run-time detection is extremely + * OS specific. + * + * You may set the macro PNG_MIPS_MSA_FILE to the file name of file containing + * a fragment of C source code which defines the png_have_msa function. There + * are a number of implementations in contrib/mips-msa, but the only one that + * has partial support is contrib/mips-msa/linux.c - a generic Linux + * implementation which reads /proc/cpufino. + */ +#ifndef PNG_MIPS_MSA_FILE +# ifdef __linux__ +# define PNG_MIPS_MSA_FILE "contrib/mips-msa/linux.c" +# endif +#endif + +#ifdef PNG_MIPS_MSA_FILE + +#include <signal.h> /* for sig_atomic_t */ +static int png_have_msa(png_structp png_ptr); +#include PNG_MIPS_MSA_FILE + +#else /* PNG_MIPS_MSA_FILE */ +# error "PNG_MIPS_MSA_FILE undefined: no support for run-time MIPS MSA checks" +#endif /* PNG_MIPS_MSA_FILE */ +#endif /* PNG_MIPS_MSA_CHECK_SUPPORTED */ + +#ifndef PNG_ALIGNED_MEMORY_SUPPORTED +# error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED" +#endif + +void +png_init_filter_functions_msa(png_structp pp, unsigned int bpp) +{ + /* The switch statement is compiled in for MIPS_MSA_API, the call to + * png_have_msa is compiled in for MIPS_MSA_CHECK. If both are defined + * the check is only performed if the API has not set the MSA option on + * or off explicitly. In this case the check controls what happens. + */ + +#ifdef PNG_MIPS_MSA_API_SUPPORTED + switch ((pp->options >> PNG_MIPS_MSA) & 3) + { + case PNG_OPTION_UNSET: + /* Allow the run-time check to execute if it has been enabled - + * thus both API and CHECK can be turned on. If it isn't supported + * this case will fall through to the 'default' below, which just + * returns. + */ +#endif /* PNG_MIPS_MSA_API_SUPPORTED */ +#ifdef PNG_MIPS_MSA_CHECK_SUPPORTED + { + static volatile sig_atomic_t no_msa = -1; /* not checked */ + + if (no_msa < 0) + no_msa = !png_have_msa(pp); + + if (no_msa) + return; + } +#ifdef PNG_MIPS_MSA_API_SUPPORTED + break; +#endif +#endif /* PNG_MIPS_MSA_CHECK_SUPPORTED */ + +#ifdef PNG_MIPS_MSA_API_SUPPORTED + default: /* OFF or INVALID */ + return; + + case PNG_OPTION_ON: + /* Option turned on */ + break; + } +#endif + + /* IMPORTANT: any new external functions used here must be declared using + * PNG_INTERNAL_FUNCTION in ../pngpriv.h. This is required so that the + * 'prefix' option to configure works: + * + * ./configure --with-libpng-prefix=foobar_ + * + * Verify you have got this right by running the above command, doing a build + * and examining pngprefix.h; it must contain a #define for every external + * function you add. (Notice that this happens automatically for the + * initialization function.) + */ + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_msa; + + if (bpp == 3) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_msa; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_msa; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth3_msa; + } + + else if (bpp == 4) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_msa; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_msa; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth4_msa; + } +} +#endif /* PNG_MIPS_MSA_OPT > 0 */ +#endif /* READ */ diff --git a/media/libpng/moz.build b/media/libpng/moz.build new file mode 100644 index 0000000000..d651b6bf49 --- /dev/null +++ b/media/libpng/moz.build @@ -0,0 +1,78 @@ +# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*- +# vim: set filetype=python: +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this +# file, You can obtain one at http://mozilla.org/MPL/2.0/. + +with Files("**"): + BUG_COMPONENT = ("Core", "ImageLib") + +EXPORTS += [ + 'png.h', + 'pngconf.h', + 'pnglibconf.h' +] + +UNIFIED_SOURCES += [ + 'png.c', + 'pngerror.c', + 'pngget.c', + 'pngmem.c', + 'pngpread.c', + 'pngread.c', + 'pngrio.c', + 'pngrtran.c', + 'pngrutil.c', + 'pngset.c', + 'pngtrans.c', + 'pngwio.c', + 'pngwrite.c', + 'pngwutil.c' +] + +if CONFIG['CPU_ARCH'] == 'arm' or CONFIG['CPU_ARCH'] == 'aarch64': + DEFINES['MOZ_PNG_USE_ARM_NEON'] = True + UNIFIED_SOURCES += [ + 'arm/arm_init.c', + 'arm/filter_neon_intrinsics.c', + 'arm/palette_neon_intrinsics.c' + ] + + if CONFIG['CPU_ARCH'] == 'arm': + SOURCES += [ + 'arm/filter_neon.S' + ] + +if CONFIG['INTEL_ARCHITECTURE']: + DEFINES['MOZ_PNG_USE_INTEL_SSE'] = True + UNIFIED_SOURCES += [ + 'intel/filter_sse2_intrinsics.c', + 'intel/intel_init.c' + ] + +if CONFIG['CPU_ARCH'] == 'mips': + DEFINES['MOZ_PNG_USE_MIPS_MSA'] = True + UNIFIED_SOURCES += [ + 'mips/filter_msa_intrinsics.c', + 'mips/mips_init.c' + ] + +if CONFIG['HAVE_ALTIVEC']: + DEFINES['MOZ_PNG_USE_POWERPC'] = True + UNIFIED_SOURCES += [ + 'powerpc/filter_vsx_intrinsics.c', + 'powerpc/powerpc_init.c' + ] + +if CONFIG['MOZ_TREE_FREETYPE']: + DEFINES['FT_CONFIG_OPTION_USE_PNG'] = True + +Library('mozpng') + +FINAL_LIBRARY = 'gkmedias' + +# We allow warnings for third-party code that can be updated from upstream. +AllowCompilerWarnings() + +if CONFIG['CC_TYPE'] in ('clang', 'gcc'): + CFLAGS += ['-std=gnu89'] diff --git a/media/libpng/moz.yaml b/media/libpng/moz.yaml new file mode 100644 index 0000000000..6cf3637862 --- /dev/null +++ b/media/libpng/moz.yaml @@ -0,0 +1,14 @@ +schema: 1 + +bugzilla: + product: "Core" + component: "ImageLib" + +origin: + name: "libpng" + description: "PNG reference library" + + url: "http://www.libpng.org/pub/png/libpng.html" + license: "libpng" + + release: "1.6.37" diff --git a/media/libpng/png.c b/media/libpng/png.c new file mode 100644 index 0000000000..757c755f97 --- /dev/null +++ b/media/libpng/png.c @@ -0,0 +1,4607 @@ + +/* png.c - location for general purpose libpng functions + * + * Copyright (c) 2018-2019 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +/* Generate a compiler error if there is an old png.h in the search path. */ +typedef png_libpng_version_1_6_37 Your_png_h_is_not_version_1_6_37; + +#ifdef __GNUC__ +/* The version tests may need to be added to, but the problem warning has + * consistently been fixed in GCC versions which obtain wide-spread release. + * The problem is that many versions of GCC rearrange comparison expressions in + * the optimizer in such a way that the results of the comparison will change + * if signed integer overflow occurs. Such comparisons are not permitted in + * ANSI C90, however GCC isn't clever enough to work out that that do not occur + * below in png_ascii_from_fp and png_muldiv, so it produces a warning with + * -Wextra. Unfortunately this is highly dependent on the optimizer and the + * machine architecture so the warning comes and goes unpredictably and is + * impossible to "fix", even were that a good idea. + */ +#if __GNUC__ == 7 && __GNUC_MINOR__ == 1 +#define GCC_STRICT_OVERFLOW 1 +#endif /* GNU 7.1.x */ +#endif /* GNU */ +#ifndef GCC_STRICT_OVERFLOW +#define GCC_STRICT_OVERFLOW 0 +#endif + +/* Tells libpng that we have already handled the first "num_bytes" bytes + * of the PNG file signature. If the PNG data is embedded into another + * stream we can set num_bytes = 8 so that libpng will not attempt to read + * or write any of the magic bytes before it starts on the IHDR. + */ + +#ifdef PNG_READ_SUPPORTED +void PNGAPI +png_set_sig_bytes(png_structrp png_ptr, int num_bytes) +{ + unsigned int nb = (unsigned int)num_bytes; + + png_debug(1, "in png_set_sig_bytes"); + + if (png_ptr == NULL) + return; + + if (num_bytes < 0) + nb = 0; + + if (nb > 8) + png_error(png_ptr, "Too many bytes for PNG signature"); + + png_ptr->sig_bytes = (png_byte)nb; +} + +/* Checks whether the supplied bytes match the PNG signature. We allow + * checking less than the full 8-byte signature so that those apps that + * already read the first few bytes of a file to determine the file type + * can simply check the remaining bytes for extra assurance. Returns + * an integer less than, equal to, or greater than zero if sig is found, + * respectively, to be less than, to match, or be greater than the correct + * PNG signature (this is the same behavior as strcmp, memcmp, etc). + */ +int PNGAPI +png_sig_cmp(png_const_bytep sig, size_t start, size_t num_to_check) +{ + png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; + + if (num_to_check > 8) + num_to_check = 8; + + else if (num_to_check < 1) + return (-1); + + if (start > 7) + return (-1); + + if (start + num_to_check > 8) + num_to_check = 8 - start; + + return ((int)(memcmp(&sig[start], &png_signature[start], num_to_check))); +} + +#endif /* READ */ + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) +/* Function to allocate memory for zlib */ +PNG_FUNCTION(voidpf /* PRIVATE */, +png_zalloc,(voidpf png_ptr, uInt items, uInt size),PNG_ALLOCATED) +{ + png_alloc_size_t num_bytes = size; + + if (png_ptr == NULL) + return NULL; + + if (items >= (~(png_alloc_size_t)0)/size) + { + png_warning (png_voidcast(png_structrp, png_ptr), + "Potential overflow in png_zalloc()"); + return NULL; + } + + num_bytes *= items; + return png_malloc_warn(png_voidcast(png_structrp, png_ptr), num_bytes); +} + +/* Function to free memory for zlib */ +void /* PRIVATE */ +png_zfree(voidpf png_ptr, voidpf ptr) +{ + png_free(png_voidcast(png_const_structrp,png_ptr), ptr); +} + +/* Reset the CRC variable to 32 bits of 1's. Care must be taken + * in case CRC is > 32 bits to leave the top bits 0. + */ +void /* PRIVATE */ +png_reset_crc(png_structrp png_ptr) +{ + /* The cast is safe because the crc is a 32-bit value. */ + png_ptr->crc = (png_uint_32)crc32(0, Z_NULL, 0); +} + +/* Calculate the CRC over a section of data. We can only pass as + * much data to this routine as the largest single buffer size. We + * also check that this data will actually be used before going to the + * trouble of calculating it. + */ +void /* PRIVATE */ +png_calculate_crc(png_structrp png_ptr, png_const_bytep ptr, size_t length) +{ + int need_crc = 1; + + if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0) + { + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == + (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) + need_crc = 0; + } + + else /* critical */ + { + if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0) + need_crc = 0; + } + + /* 'uLong' is defined in zlib.h as unsigned long; this means that on some + * systems it is a 64-bit value. crc32, however, returns 32 bits so the + * following cast is safe. 'uInt' may be no more than 16 bits, so it is + * necessary to perform a loop here. + */ + if (need_crc != 0 && length > 0) + { + uLong crc = png_ptr->crc; /* Should never issue a warning */ + + do + { + uInt safe_length = (uInt)length; +#ifndef __COVERITY__ + if (safe_length == 0) + safe_length = (uInt)-1; /* evil, but safe */ +#endif + + crc = crc32(crc, ptr, safe_length); + + /* The following should never issue compiler warnings; if they do the + * target system has characteristics that will probably violate other + * assumptions within the libpng code. + */ + ptr += safe_length; + length -= safe_length; + } + while (length > 0); + + /* And the following is always safe because the crc is only 32 bits. */ + png_ptr->crc = (png_uint_32)crc; + } +} + +/* Check a user supplied version number, called from both read and write + * functions that create a png_struct. + */ +int +png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver) +{ + /* Libpng versions 1.0.0 and later are binary compatible if the version + * string matches through the second '.'; we must recompile any + * applications that use any older library version. + */ + + if (user_png_ver != NULL) + { + int i = -1; + int found_dots = 0; + + do + { + i++; + if (user_png_ver[i] != PNG_LIBPNG_VER_STRING[i]) + png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; + if (user_png_ver[i] == '.') + found_dots++; + } while (found_dots < 2 && user_png_ver[i] != 0 && + PNG_LIBPNG_VER_STRING[i] != 0); + } + + else + png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; + + if ((png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) != 0) + { +#ifdef PNG_WARNINGS_SUPPORTED + size_t pos = 0; + char m[128]; + + pos = png_safecat(m, (sizeof m), pos, + "Application built with libpng-"); + pos = png_safecat(m, (sizeof m), pos, user_png_ver); + pos = png_safecat(m, (sizeof m), pos, " but running with "); + pos = png_safecat(m, (sizeof m), pos, PNG_LIBPNG_VER_STRING); + PNG_UNUSED(pos) + + png_warning(png_ptr, m); +#endif + +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + png_ptr->flags = 0; +#endif + + return 0; + } + + /* Success return. */ + return 1; +} + +/* Generic function to create a png_struct for either read or write - this + * contains the common initialization. + */ +PNG_FUNCTION(png_structp /* PRIVATE */, +png_create_png_struct,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, + png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) +{ + png_struct create_struct; +# ifdef PNG_SETJMP_SUPPORTED + jmp_buf create_jmp_buf; +# endif + + /* This temporary stack-allocated structure is used to provide a place to + * build enough context to allow the user provided memory allocator (if any) + * to be called. + */ + memset(&create_struct, 0, (sizeof create_struct)); + + /* Added at libpng-1.2.6 */ +# ifdef PNG_USER_LIMITS_SUPPORTED + create_struct.user_width_max = PNG_USER_WIDTH_MAX; + create_struct.user_height_max = PNG_USER_HEIGHT_MAX; + +# ifdef PNG_USER_CHUNK_CACHE_MAX + /* Added at libpng-1.2.43 and 1.4.0 */ + create_struct.user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX; +# endif + +# ifdef PNG_USER_CHUNK_MALLOC_MAX + /* Added at libpng-1.2.43 and 1.4.1, required only for read but exists + * in png_struct regardless. + */ + create_struct.user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX; +# endif +# endif + + /* The following two API calls simply set fields in png_struct, so it is safe + * to do them now even though error handling is not yet set up. + */ +# ifdef PNG_USER_MEM_SUPPORTED + png_set_mem_fn(&create_struct, mem_ptr, malloc_fn, free_fn); +# else + PNG_UNUSED(mem_ptr) + PNG_UNUSED(malloc_fn) + PNG_UNUSED(free_fn) +# endif + + /* (*error_fn) can return control to the caller after the error_ptr is set, + * this will result in a memory leak unless the error_fn does something + * extremely sophisticated. The design lacks merit but is implicit in the + * API. + */ + png_set_error_fn(&create_struct, error_ptr, error_fn, warn_fn); + +# ifdef PNG_SETJMP_SUPPORTED + if (!setjmp(create_jmp_buf)) +# endif + { +# ifdef PNG_SETJMP_SUPPORTED + /* Temporarily fake out the longjmp information until we have + * successfully completed this function. This only works if we have + * setjmp() support compiled in, but it is safe - this stuff should + * never happen. + */ + create_struct.jmp_buf_ptr = &create_jmp_buf; + create_struct.jmp_buf_size = 0; /*stack allocation*/ + create_struct.longjmp_fn = longjmp; +# endif + /* Call the general version checker (shared with read and write code): + */ + if (png_user_version_check(&create_struct, user_png_ver) != 0) + { + png_structrp png_ptr = png_voidcast(png_structrp, + png_malloc_warn(&create_struct, (sizeof *png_ptr))); + + if (png_ptr != NULL) + { + /* png_ptr->zstream holds a back-pointer to the png_struct, so + * this can only be done now: + */ + create_struct.zstream.zalloc = png_zalloc; + create_struct.zstream.zfree = png_zfree; + create_struct.zstream.opaque = png_ptr; + +# ifdef PNG_SETJMP_SUPPORTED + /* Eliminate the local error handling: */ + create_struct.jmp_buf_ptr = NULL; + create_struct.jmp_buf_size = 0; + create_struct.longjmp_fn = 0; +# endif + + *png_ptr = create_struct; + + /* This is the successful return point */ + return png_ptr; + } + } + } + + /* A longjmp because of a bug in the application storage allocator or a + * simple failure to allocate the png_struct. + */ + return NULL; +} + +/* Allocate the memory for an info_struct for the application. */ +PNG_FUNCTION(png_infop,PNGAPI +png_create_info_struct,(png_const_structrp png_ptr),PNG_ALLOCATED) +{ + png_inforp info_ptr; + + png_debug(1, "in png_create_info_struct"); + + if (png_ptr == NULL) + return NULL; + + /* Use the internal API that does not (or at least should not) error out, so + * that this call always returns ok. The application typically sets up the + * error handling *after* creating the info_struct because this is the way it + * has always been done in 'example.c'. + */ + info_ptr = png_voidcast(png_inforp, png_malloc_base(png_ptr, + (sizeof *info_ptr))); + + if (info_ptr != NULL) + memset(info_ptr, 0, (sizeof *info_ptr)); + + return info_ptr; +} + +/* This function frees the memory associated with a single info struct. + * Normally, one would use either png_destroy_read_struct() or + * png_destroy_write_struct() to free an info struct, but this may be + * useful for some applications. From libpng 1.6.0 this function is also used + * internally to implement the png_info release part of the 'struct' destroy + * APIs. This ensures that all possible approaches free the same data (all of + * it). + */ +void PNGAPI +png_destroy_info_struct(png_const_structrp png_ptr, png_infopp info_ptr_ptr) +{ + png_inforp info_ptr = NULL; + + png_debug(1, "in png_destroy_info_struct"); + + if (png_ptr == NULL) + return; + + if (info_ptr_ptr != NULL) + info_ptr = *info_ptr_ptr; + + if (info_ptr != NULL) + { + /* Do this first in case of an error below; if the app implements its own + * memory management this can lead to png_free calling png_error, which + * will abort this routine and return control to the app error handler. + * An infinite loop may result if it then tries to free the same info + * ptr. + */ + *info_ptr_ptr = NULL; + + png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1); + memset(info_ptr, 0, (sizeof *info_ptr)); + png_free(png_ptr, info_ptr); + } +} + +/* Initialize the info structure. This is now an internal function (0.89) + * and applications using it are urged to use png_create_info_struct() + * instead. Use deprecated in 1.6.0, internal use removed (used internally it + * is just a memset). + * + * NOTE: it is almost inconceivable that this API is used because it bypasses + * the user-memory mechanism and the user error handling/warning mechanisms in + * those cases where it does anything other than a memset. + */ +PNG_FUNCTION(void,PNGAPI +png_info_init_3,(png_infopp ptr_ptr, size_t png_info_struct_size), + PNG_DEPRECATED) +{ + png_inforp info_ptr = *ptr_ptr; + + png_debug(1, "in png_info_init_3"); + + if (info_ptr == NULL) + return; + + if ((sizeof (png_info)) > png_info_struct_size) + { + *ptr_ptr = NULL; + /* The following line is why this API should not be used: */ + free(info_ptr); + info_ptr = png_voidcast(png_inforp, png_malloc_base(NULL, + (sizeof *info_ptr))); + if (info_ptr == NULL) + return; + *ptr_ptr = info_ptr; + } + + /* Set everything to 0 */ + memset(info_ptr, 0, (sizeof *info_ptr)); +} + +/* The following API is not called internally */ +void PNGAPI +png_data_freer(png_const_structrp png_ptr, png_inforp info_ptr, + int freer, png_uint_32 mask) +{ + png_debug(1, "in png_data_freer"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (freer == PNG_DESTROY_WILL_FREE_DATA) + info_ptr->free_me |= mask; + + else if (freer == PNG_USER_WILL_FREE_DATA) + info_ptr->free_me &= ~mask; + + else + png_error(png_ptr, "Unknown freer parameter in png_data_freer"); +} + +void PNGAPI +png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask, + int num) +{ + png_debug(1, "in png_free_data"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + +#ifdef PNG_TEXT_SUPPORTED + /* Free text item num or (if num == -1) all text items */ + if (info_ptr->text != NULL && + ((mask & PNG_FREE_TEXT) & info_ptr->free_me) != 0) + { + if (num != -1) + { + png_free(png_ptr, info_ptr->text[num].key); + info_ptr->text[num].key = NULL; + } + + else + { + int i; + + for (i = 0; i < info_ptr->num_text; i++) + png_free(png_ptr, info_ptr->text[i].key); + + png_free(png_ptr, info_ptr->text); + info_ptr->text = NULL; + info_ptr->num_text = 0; + info_ptr->max_text = 0; + } + } +#endif + +#ifdef PNG_tRNS_SUPPORTED + /* Free any tRNS entry */ + if (((mask & PNG_FREE_TRNS) & info_ptr->free_me) != 0) + { + info_ptr->valid &= ~PNG_INFO_tRNS; + png_free(png_ptr, info_ptr->trans_alpha); + info_ptr->trans_alpha = NULL; + info_ptr->num_trans = 0; + } +#endif + +#ifdef PNG_sCAL_SUPPORTED + /* Free any sCAL entry */ + if (((mask & PNG_FREE_SCAL) & info_ptr->free_me) != 0) + { + png_free(png_ptr, info_ptr->scal_s_width); + png_free(png_ptr, info_ptr->scal_s_height); + info_ptr->scal_s_width = NULL; + info_ptr->scal_s_height = NULL; + info_ptr->valid &= ~PNG_INFO_sCAL; + } +#endif + +#ifdef PNG_pCAL_SUPPORTED + /* Free any pCAL entry */ + if (((mask & PNG_FREE_PCAL) & info_ptr->free_me) != 0) + { + png_free(png_ptr, info_ptr->pcal_purpose); + png_free(png_ptr, info_ptr->pcal_units); + info_ptr->pcal_purpose = NULL; + info_ptr->pcal_units = NULL; + + if (info_ptr->pcal_params != NULL) + { + int i; + + for (i = 0; i < info_ptr->pcal_nparams; i++) + png_free(png_ptr, info_ptr->pcal_params[i]); + + png_free(png_ptr, info_ptr->pcal_params); + info_ptr->pcal_params = NULL; + } + info_ptr->valid &= ~PNG_INFO_pCAL; + } +#endif + +#ifdef PNG_iCCP_SUPPORTED + /* Free any profile entry */ + if (((mask & PNG_FREE_ICCP) & info_ptr->free_me) != 0) + { + png_free(png_ptr, info_ptr->iccp_name); + png_free(png_ptr, info_ptr->iccp_profile); + info_ptr->iccp_name = NULL; + info_ptr->iccp_profile = NULL; + info_ptr->valid &= ~PNG_INFO_iCCP; + } +#endif + +#ifdef PNG_sPLT_SUPPORTED + /* Free a given sPLT entry, or (if num == -1) all sPLT entries */ + if (info_ptr->splt_palettes != NULL && + ((mask & PNG_FREE_SPLT) & info_ptr->free_me) != 0) + { + if (num != -1) + { + png_free(png_ptr, info_ptr->splt_palettes[num].name); + png_free(png_ptr, info_ptr->splt_palettes[num].entries); + info_ptr->splt_palettes[num].name = NULL; + info_ptr->splt_palettes[num].entries = NULL; + } + + else + { + int i; + + for (i = 0; i < info_ptr->splt_palettes_num; i++) + { + png_free(png_ptr, info_ptr->splt_palettes[i].name); + png_free(png_ptr, info_ptr->splt_palettes[i].entries); + } + + png_free(png_ptr, info_ptr->splt_palettes); + info_ptr->splt_palettes = NULL; + info_ptr->splt_palettes_num = 0; + info_ptr->valid &= ~PNG_INFO_sPLT; + } + } +#endif + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED + if (info_ptr->unknown_chunks != NULL && + ((mask & PNG_FREE_UNKN) & info_ptr->free_me) != 0) + { + if (num != -1) + { + png_free(png_ptr, info_ptr->unknown_chunks[num].data); + info_ptr->unknown_chunks[num].data = NULL; + } + + else + { + int i; + + for (i = 0; i < info_ptr->unknown_chunks_num; i++) + png_free(png_ptr, info_ptr->unknown_chunks[i].data); + + png_free(png_ptr, info_ptr->unknown_chunks); + info_ptr->unknown_chunks = NULL; + info_ptr->unknown_chunks_num = 0; + } + } +#endif + +#ifdef PNG_eXIf_SUPPORTED + /* Free any eXIf entry */ + if (((mask & PNG_FREE_EXIF) & info_ptr->free_me) != 0) + { +# ifdef PNG_READ_eXIf_SUPPORTED + if (info_ptr->eXIf_buf) + { + png_free(png_ptr, info_ptr->eXIf_buf); + info_ptr->eXIf_buf = NULL; + } +# endif + if (info_ptr->exif) + { + png_free(png_ptr, info_ptr->exif); + info_ptr->exif = NULL; + } + info_ptr->valid &= ~PNG_INFO_eXIf; + } +#endif + +#ifdef PNG_hIST_SUPPORTED + /* Free any hIST entry */ + if (((mask & PNG_FREE_HIST) & info_ptr->free_me) != 0) + { + png_free(png_ptr, info_ptr->hist); + info_ptr->hist = NULL; + info_ptr->valid &= ~PNG_INFO_hIST; + } +#endif + + /* Free any PLTE entry that was internally allocated */ + if (((mask & PNG_FREE_PLTE) & info_ptr->free_me) != 0) + { + png_free(png_ptr, info_ptr->palette); + info_ptr->palette = NULL; + info_ptr->valid &= ~PNG_INFO_PLTE; + info_ptr->num_palette = 0; + } + +#ifdef PNG_INFO_IMAGE_SUPPORTED + /* Free any image bits attached to the info structure */ + if (((mask & PNG_FREE_ROWS) & info_ptr->free_me) != 0) + { + if (info_ptr->row_pointers != NULL) + { + png_uint_32 row; + for (row = 0; row < info_ptr->height; row++) + png_free(png_ptr, info_ptr->row_pointers[row]); + + png_free(png_ptr, info_ptr->row_pointers); + info_ptr->row_pointers = NULL; + } + info_ptr->valid &= ~PNG_INFO_IDAT; + } +#endif + + if (num != -1) + mask &= ~PNG_FREE_MUL; + + info_ptr->free_me &= ~mask; +} +#endif /* READ || WRITE */ + +/* This function returns a pointer to the io_ptr associated with the user + * functions. The application should free any memory associated with this + * pointer before png_write_destroy() or png_read_destroy() are called. + */ +png_voidp PNGAPI +png_get_io_ptr(png_const_structrp png_ptr) +{ + if (png_ptr == NULL) + return (NULL); + + return (png_ptr->io_ptr); +} + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) +# ifdef PNG_STDIO_SUPPORTED +/* Initialize the default input/output functions for the PNG file. If you + * use your own read or write routines, you can call either png_set_read_fn() + * or png_set_write_fn() instead of png_init_io(). If you have defined + * PNG_NO_STDIO or otherwise disabled PNG_STDIO_SUPPORTED, you must use a + * function of your own because "FILE *" isn't necessarily available. + */ +void PNGAPI +png_init_io(png_structrp png_ptr, png_FILE_p fp) +{ + png_debug(1, "in png_init_io"); + + if (png_ptr == NULL) + return; + + png_ptr->io_ptr = (png_voidp)fp; +} +# endif + +# ifdef PNG_SAVE_INT_32_SUPPORTED +/* PNG signed integers are saved in 32-bit 2's complement format. ANSI C-90 + * defines a cast of a signed integer to an unsigned integer either to preserve + * the value, if it is positive, or to calculate: + * + * (UNSIGNED_MAX+1) + integer + * + * Where UNSIGNED_MAX is the appropriate maximum unsigned value, so when the + * negative integral value is added the result will be an unsigned value + * correspnding to the 2's complement representation. + */ +void PNGAPI +png_save_int_32(png_bytep buf, png_int_32 i) +{ + png_save_uint_32(buf, (png_uint_32)i); +} +# endif + +# ifdef PNG_TIME_RFC1123_SUPPORTED +/* Convert the supplied time into an RFC 1123 string suitable for use in + * a "Creation Time" or other text-based time string. + */ +int PNGAPI +png_convert_to_rfc1123_buffer(char out[29], png_const_timep ptime) +{ + static const char short_months[12][4] = + {"Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; + + if (out == NULL) + return 0; + + if (ptime->year > 9999 /* RFC1123 limitation */ || + ptime->month == 0 || ptime->month > 12 || + ptime->day == 0 || ptime->day > 31 || + ptime->hour > 23 || ptime->minute > 59 || + ptime->second > 60) + return 0; + + { + size_t pos = 0; + char number_buf[5]; /* enough for a four-digit year */ + +# define APPEND_STRING(string) pos = png_safecat(out, 29, pos, (string)) +# define APPEND_NUMBER(format, value)\ + APPEND_STRING(PNG_FORMAT_NUMBER(number_buf, format, (value))) +# define APPEND(ch) if (pos < 28) out[pos++] = (ch) + + APPEND_NUMBER(PNG_NUMBER_FORMAT_u, (unsigned)ptime->day); + APPEND(' '); + APPEND_STRING(short_months[(ptime->month - 1)]); + APPEND(' '); + APPEND_NUMBER(PNG_NUMBER_FORMAT_u, ptime->year); + APPEND(' '); + APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->hour); + APPEND(':'); + APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->minute); + APPEND(':'); + APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->second); + APPEND_STRING(" +0000"); /* This reliably terminates the buffer */ + PNG_UNUSED (pos) + +# undef APPEND +# undef APPEND_NUMBER +# undef APPEND_STRING + } + + return 1; +} + +# if PNG_LIBPNG_VER < 10700 +/* To do: remove the following from libpng-1.7 */ +/* Original API that uses a private buffer in png_struct. + * Deprecated because it causes png_struct to carry a spurious temporary + * buffer (png_struct::time_buffer), better to have the caller pass this in. + */ +png_const_charp PNGAPI +png_convert_to_rfc1123(png_structrp png_ptr, png_const_timep ptime) +{ + if (png_ptr != NULL) + { + /* The only failure above if png_ptr != NULL is from an invalid ptime */ + if (png_convert_to_rfc1123_buffer(png_ptr->time_buffer, ptime) == 0) + png_warning(png_ptr, "Ignoring invalid time value"); + + else + return png_ptr->time_buffer; + } + + return NULL; +} +# endif /* LIBPNG_VER < 10700 */ +# endif /* TIME_RFC1123 */ + +#endif /* READ || WRITE */ + +png_const_charp PNGAPI +png_get_copyright(png_const_structrp png_ptr) +{ + PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */ +#ifdef PNG_STRING_COPYRIGHT + return PNG_STRING_COPYRIGHT +#else + return PNG_STRING_NEWLINE \ + "libpng version 1.6.37" PNG_STRING_NEWLINE \ + "Copyright (c) 2018-2019 Cosmin Truta" PNG_STRING_NEWLINE \ + "Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson" \ + PNG_STRING_NEWLINE \ + "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \ + "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \ + PNG_STRING_NEWLINE; +#endif +} + +/* The following return the library version as a short string in the + * format 1.0.0 through 99.99.99zz. To get the version of *.h files + * used with your application, print out PNG_LIBPNG_VER_STRING, which + * is defined in png.h. + * Note: now there is no difference between png_get_libpng_ver() and + * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard, + * it is guaranteed that png.c uses the correct version of png.h. + */ +png_const_charp PNGAPI +png_get_libpng_ver(png_const_structrp png_ptr) +{ + /* Version of *.c files used when building libpng */ + return png_get_header_ver(png_ptr); +} + +png_const_charp PNGAPI +png_get_header_ver(png_const_structrp png_ptr) +{ + /* Version of *.h files used when building libpng */ + PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */ + return PNG_LIBPNG_VER_STRING; +} + +png_const_charp PNGAPI +png_get_header_version(png_const_structrp png_ptr) +{ + /* Returns longer string containing both version and date */ + PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */ +#ifdef __STDC__ + return PNG_HEADER_VERSION_STRING +# ifndef PNG_READ_SUPPORTED + " (NO READ SUPPORT)" +# endif + PNG_STRING_NEWLINE; +#else + return PNG_HEADER_VERSION_STRING; +#endif +} + +#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED +/* NOTE: this routine is not used internally! */ +/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth + * large of png_color. This lets grayscale images be treated as + * paletted. Most useful for gamma correction and simplification + * of code. This API is not used internally. + */ +void PNGAPI +png_build_grayscale_palette(int bit_depth, png_colorp palette) +{ + int num_palette; + int color_inc; + int i; + int v; + + png_debug(1, "in png_do_build_grayscale_palette"); + + if (palette == NULL) + return; + + switch (bit_depth) + { + case 1: + num_palette = 2; + color_inc = 0xff; + break; + + case 2: + num_palette = 4; + color_inc = 0x55; + break; + + case 4: + num_palette = 16; + color_inc = 0x11; + break; + + case 8: + num_palette = 256; + color_inc = 1; + break; + + default: + num_palette = 0; + color_inc = 0; + break; + } + + for (i = 0, v = 0; i < num_palette; i++, v += color_inc) + { + palette[i].red = (png_byte)(v & 0xff); + palette[i].green = (png_byte)(v & 0xff); + palette[i].blue = (png_byte)(v & 0xff); + } +} +#endif + +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED +int PNGAPI +png_handle_as_unknown(png_const_structrp png_ptr, png_const_bytep chunk_name) +{ + /* Check chunk_name and return "keep" value if it's on the list, else 0 */ + png_const_bytep p, p_end; + + if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list == 0) + return PNG_HANDLE_CHUNK_AS_DEFAULT; + + p_end = png_ptr->chunk_list; + p = p_end + png_ptr->num_chunk_list*5; /* beyond end */ + + /* The code is the fifth byte after each four byte string. Historically this + * code was always searched from the end of the list, this is no longer + * necessary because the 'set' routine handles duplicate entries correctly. + */ + do /* num_chunk_list > 0, so at least one */ + { + p -= 5; + + if (memcmp(chunk_name, p, 4) == 0) + return p[4]; + } + while (p > p_end); + + /* This means that known chunks should be processed and unknown chunks should + * be handled according to the value of png_ptr->unknown_default; this can be + * confusing because, as a result, there are two levels of defaulting for + * unknown chunks. + */ + return PNG_HANDLE_CHUNK_AS_DEFAULT; +} + +#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\ + defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED) +int /* PRIVATE */ +png_chunk_unknown_handling(png_const_structrp png_ptr, png_uint_32 chunk_name) +{ + png_byte chunk_string[5]; + + PNG_CSTRING_FROM_CHUNK(chunk_string, chunk_name); + return png_handle_as_unknown(png_ptr, chunk_string); +} +#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */ +#endif /* SET_UNKNOWN_CHUNKS */ + +#ifdef PNG_READ_SUPPORTED +/* This function, added to libpng-1.0.6g, is untested. */ +int PNGAPI +png_reset_zstream(png_structrp png_ptr) +{ + if (png_ptr == NULL) + return Z_STREAM_ERROR; + + /* WARNING: this resets the window bits to the maximum! */ + return (inflateReset(&png_ptr->zstream)); +} +#endif /* READ */ + +/* This function was added to libpng-1.0.7 */ +png_uint_32 PNGAPI +png_access_version_number(void) +{ + /* Version of *.c files used when building libpng */ + return((png_uint_32)PNG_LIBPNG_VER); +} + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) +/* Ensure that png_ptr->zstream.msg holds some appropriate error message string. + * If it doesn't 'ret' is used to set it to something appropriate, even in cases + * like Z_OK or Z_STREAM_END where the error code is apparently a success code. + */ +void /* PRIVATE */ +png_zstream_error(png_structrp png_ptr, int ret) +{ + /* Translate 'ret' into an appropriate error string, priority is given to the + * one in zstream if set. This always returns a string, even in cases like + * Z_OK or Z_STREAM_END where the error code is a success code. + */ + if (png_ptr->zstream.msg == NULL) switch (ret) + { + default: + case Z_OK: + png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return code"); + break; + + case Z_STREAM_END: + /* Normal exit */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected end of LZ stream"); + break; + + case Z_NEED_DICT: + /* This means the deflate stream did not have a dictionary; this + * indicates a bogus PNG. + */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("missing LZ dictionary"); + break; + + case Z_ERRNO: + /* gz APIs only: should not happen */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("zlib IO error"); + break; + + case Z_STREAM_ERROR: + /* internal libpng error */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("bad parameters to zlib"); + break; + + case Z_DATA_ERROR: + png_ptr->zstream.msg = PNGZ_MSG_CAST("damaged LZ stream"); + break; + + case Z_MEM_ERROR: + png_ptr->zstream.msg = PNGZ_MSG_CAST("insufficient memory"); + break; + + case Z_BUF_ERROR: + /* End of input or output; not a problem if the caller is doing + * incremental read or write. + */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("truncated"); + break; + + case Z_VERSION_ERROR: + png_ptr->zstream.msg = PNGZ_MSG_CAST("unsupported zlib version"); + break; + + case PNG_UNEXPECTED_ZLIB_RETURN: + /* Compile errors here mean that zlib now uses the value co-opted in + * pngpriv.h for PNG_UNEXPECTED_ZLIB_RETURN; update the switch above + * and change pngpriv.h. Note that this message is "... return", + * whereas the default/Z_OK one is "... return code". + */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return"); + break; + } +} + +/* png_convert_size: a PNGAPI but no longer in png.h, so deleted + * at libpng 1.5.5! + */ + +/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */ +#ifdef PNG_GAMMA_SUPPORTED /* always set if COLORSPACE */ +static int +png_colorspace_check_gamma(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_fixed_point gAMA, int from) + /* This is called to check a new gamma value against an existing one. The + * routine returns false if the new gamma value should not be written. + * + * 'from' says where the new gamma value comes from: + * + * 0: the new gamma value is the libpng estimate for an ICC profile + * 1: the new gamma value comes from a gAMA chunk + * 2: the new gamma value comes from an sRGB chunk + */ +{ + png_fixed_point gtest; + + if ((colorspace->flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 && + (png_muldiv(>est, colorspace->gamma, PNG_FP_1, gAMA) == 0 || + png_gamma_significant(gtest) != 0)) + { + /* Either this is an sRGB image, in which case the calculated gamma + * approximation should match, or this is an image with a profile and the + * value libpng calculates for the gamma of the profile does not match the + * value recorded in the file. The former, sRGB, case is an error, the + * latter is just a warning. + */ + if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0 || from == 2) + { + png_chunk_report(png_ptr, "gamma value does not match sRGB", + PNG_CHUNK_ERROR); + /* Do not overwrite an sRGB value */ + return from == 2; + } + + else /* sRGB tag not involved */ + { + png_chunk_report(png_ptr, "gamma value does not match libpng estimate", + PNG_CHUNK_WARNING); + return from == 1; + } + } + + return 1; +} + +void /* PRIVATE */ +png_colorspace_set_gamma(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_fixed_point gAMA) +{ + /* Changed in libpng-1.5.4 to limit the values to ensure overflow can't + * occur. Since the fixed point representation is asymmetrical it is + * possible for 1/gamma to overflow the limit of 21474 and this means the + * gamma value must be at least 5/100000 and hence at most 20000.0. For + * safety the limits here are a little narrower. The values are 0.00016 to + * 6250.0, which are truly ridiculous gamma values (and will produce + * displays that are all black or all white.) + * + * In 1.6.0 this test replaces the ones in pngrutil.c, in the gAMA chunk + * handling code, which only required the value to be >0. + */ + png_const_charp errmsg; + + if (gAMA < 16 || gAMA > 625000000) + errmsg = "gamma value out of range"; + +# ifdef PNG_READ_gAMA_SUPPORTED + /* Allow the application to set the gamma value more than once */ + else if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && + (colorspace->flags & PNG_COLORSPACE_FROM_gAMA) != 0) + errmsg = "duplicate"; +# endif + + /* Do nothing if the colorspace is already invalid */ + else if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) + return; + + else + { + if (png_colorspace_check_gamma(png_ptr, colorspace, gAMA, + 1/*from gAMA*/) != 0) + { + /* Store this gamma value. */ + colorspace->gamma = gAMA; + colorspace->flags |= + (PNG_COLORSPACE_HAVE_GAMMA | PNG_COLORSPACE_FROM_gAMA); + } + + /* At present if the check_gamma test fails the gamma of the colorspace is + * not updated however the colorspace is not invalidated. This + * corresponds to the case where the existing gamma comes from an sRGB + * chunk or profile. An error message has already been output. + */ + return; + } + + /* Error exit - errmsg has been set. */ + colorspace->flags |= PNG_COLORSPACE_INVALID; + png_chunk_report(png_ptr, errmsg, PNG_CHUNK_WRITE_ERROR); +} + +void /* PRIVATE */ +png_colorspace_sync_info(png_const_structrp png_ptr, png_inforp info_ptr) +{ + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) + { + /* Everything is invalid */ + info_ptr->valid &= ~(PNG_INFO_gAMA|PNG_INFO_cHRM|PNG_INFO_sRGB| + PNG_INFO_iCCP); + +# ifdef PNG_COLORSPACE_SUPPORTED + /* Clean up the iCCP profile now if it won't be used. */ + png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, -1/*not used*/); +# else + PNG_UNUSED(png_ptr) +# endif + } + + else + { +# ifdef PNG_COLORSPACE_SUPPORTED + /* Leave the INFO_iCCP flag set if the pngset.c code has already set + * it; this allows a PNG to contain a profile which matches sRGB and + * yet still have that profile retrievable by the application. + */ + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_MATCHES_sRGB) != 0) + info_ptr->valid |= PNG_INFO_sRGB; + + else + info_ptr->valid &= ~PNG_INFO_sRGB; + + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + info_ptr->valid |= PNG_INFO_cHRM; + + else + info_ptr->valid &= ~PNG_INFO_cHRM; +# endif + + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0) + info_ptr->valid |= PNG_INFO_gAMA; + + else + info_ptr->valid &= ~PNG_INFO_gAMA; + } +} + +#ifdef PNG_READ_SUPPORTED +void /* PRIVATE */ +png_colorspace_sync(png_const_structrp png_ptr, png_inforp info_ptr) +{ + if (info_ptr == NULL) /* reduce code size; check here not in the caller */ + return; + + info_ptr->colorspace = png_ptr->colorspace; + png_colorspace_sync_info(png_ptr, info_ptr); +} +#endif +#endif /* GAMMA */ + +#ifdef PNG_COLORSPACE_SUPPORTED +/* Added at libpng-1.5.5 to support read and write of true CIEXYZ values for + * cHRM, as opposed to using chromaticities. These internal APIs return + * non-zero on a parameter error. The X, Y and Z values are required to be + * positive and less than 1.0. + */ +static int +png_xy_from_XYZ(png_xy *xy, const png_XYZ *XYZ) +{ + png_int_32 d, dwhite, whiteX, whiteY; + + d = XYZ->red_X + XYZ->red_Y + XYZ->red_Z; + if (png_muldiv(&xy->redx, XYZ->red_X, PNG_FP_1, d) == 0) + return 1; + if (png_muldiv(&xy->redy, XYZ->red_Y, PNG_FP_1, d) == 0) + return 1; + dwhite = d; + whiteX = XYZ->red_X; + whiteY = XYZ->red_Y; + + d = XYZ->green_X + XYZ->green_Y + XYZ->green_Z; + if (png_muldiv(&xy->greenx, XYZ->green_X, PNG_FP_1, d) == 0) + return 1; + if (png_muldiv(&xy->greeny, XYZ->green_Y, PNG_FP_1, d) == 0) + return 1; + dwhite += d; + whiteX += XYZ->green_X; + whiteY += XYZ->green_Y; + + d = XYZ->blue_X + XYZ->blue_Y + XYZ->blue_Z; + if (png_muldiv(&xy->bluex, XYZ->blue_X, PNG_FP_1, d) == 0) + return 1; + if (png_muldiv(&xy->bluey, XYZ->blue_Y, PNG_FP_1, d) == 0) + return 1; + dwhite += d; + whiteX += XYZ->blue_X; + whiteY += XYZ->blue_Y; + + /* The reference white is simply the sum of the end-point (X,Y,Z) vectors, + * thus: + */ + if (png_muldiv(&xy->whitex, whiteX, PNG_FP_1, dwhite) == 0) + return 1; + if (png_muldiv(&xy->whitey, whiteY, PNG_FP_1, dwhite) == 0) + return 1; + + return 0; +} + +static int +png_XYZ_from_xy(png_XYZ *XYZ, const png_xy *xy) +{ + png_fixed_point red_inverse, green_inverse, blue_scale; + png_fixed_point left, right, denominator; + + /* Check xy and, implicitly, z. Note that wide gamut color spaces typically + * have end points with 0 tristimulus values (these are impossible end + * points, but they are used to cover the possible colors). We check + * xy->whitey against 5, not 0, to avoid a possible integer overflow. + */ + if (xy->redx < 0 || xy->redx > PNG_FP_1) return 1; + if (xy->redy < 0 || xy->redy > PNG_FP_1-xy->redx) return 1; + if (xy->greenx < 0 || xy->greenx > PNG_FP_1) return 1; + if (xy->greeny < 0 || xy->greeny > PNG_FP_1-xy->greenx) return 1; + if (xy->bluex < 0 || xy->bluex > PNG_FP_1) return 1; + if (xy->bluey < 0 || xy->bluey > PNG_FP_1-xy->bluex) return 1; + if (xy->whitex < 0 || xy->whitex > PNG_FP_1) return 1; + if (xy->whitey < 5 || xy->whitey > PNG_FP_1-xy->whitex) return 1; + + /* The reverse calculation is more difficult because the original tristimulus + * value had 9 independent values (red,green,blue)x(X,Y,Z) however only 8 + * derived values were recorded in the cHRM chunk; + * (red,green,blue,white)x(x,y). This loses one degree of freedom and + * therefore an arbitrary ninth value has to be introduced to undo the + * original transformations. + * + * Think of the original end-points as points in (X,Y,Z) space. The + * chromaticity values (c) have the property: + * + * C + * c = --------- + * X + Y + Z + * + * For each c (x,y,z) from the corresponding original C (X,Y,Z). Thus the + * three chromaticity values (x,y,z) for each end-point obey the + * relationship: + * + * x + y + z = 1 + * + * This describes the plane in (X,Y,Z) space that intersects each axis at the + * value 1.0; call this the chromaticity plane. Thus the chromaticity + * calculation has scaled each end-point so that it is on the x+y+z=1 plane + * and chromaticity is the intersection of the vector from the origin to the + * (X,Y,Z) value with the chromaticity plane. + * + * To fully invert the chromaticity calculation we would need the three + * end-point scale factors, (red-scale, green-scale, blue-scale), but these + * were not recorded. Instead we calculated the reference white (X,Y,Z) and + * recorded the chromaticity of this. The reference white (X,Y,Z) would have + * given all three of the scale factors since: + * + * color-C = color-c * color-scale + * white-C = red-C + green-C + blue-C + * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale + * + * But cHRM records only white-x and white-y, so we have lost the white scale + * factor: + * + * white-C = white-c*white-scale + * + * To handle this the inverse transformation makes an arbitrary assumption + * about white-scale: + * + * Assume: white-Y = 1.0 + * Hence: white-scale = 1/white-y + * Or: red-Y + green-Y + blue-Y = 1.0 + * + * Notice the last statement of the assumption gives an equation in three of + * the nine values we want to calculate. 8 more equations come from the + * above routine as summarised at the top above (the chromaticity + * calculation): + * + * Given: color-x = color-X / (color-X + color-Y + color-Z) + * Hence: (color-x - 1)*color-X + color.x*color-Y + color.x*color-Z = 0 + * + * This is 9 simultaneous equations in the 9 variables "color-C" and can be + * solved by Cramer's rule. Cramer's rule requires calculating 10 9x9 matrix + * determinants, however this is not as bad as it seems because only 28 of + * the total of 90 terms in the various matrices are non-zero. Nevertheless + * Cramer's rule is notoriously numerically unstable because the determinant + * calculation involves the difference of large, but similar, numbers. It is + * difficult to be sure that the calculation is stable for real world values + * and it is certain that it becomes unstable where the end points are close + * together. + * + * So this code uses the perhaps slightly less optimal but more + * understandable and totally obvious approach of calculating color-scale. + * + * This algorithm depends on the precision in white-scale and that is + * (1/white-y), so we can immediately see that as white-y approaches 0 the + * accuracy inherent in the cHRM chunk drops off substantially. + * + * libpng arithmetic: a simple inversion of the above equations + * ------------------------------------------------------------ + * + * white_scale = 1/white-y + * white-X = white-x * white-scale + * white-Y = 1.0 + * white-Z = (1 - white-x - white-y) * white_scale + * + * white-C = red-C + green-C + blue-C + * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale + * + * This gives us three equations in (red-scale,green-scale,blue-scale) where + * all the coefficients are now known: + * + * red-x*red-scale + green-x*green-scale + blue-x*blue-scale + * = white-x/white-y + * red-y*red-scale + green-y*green-scale + blue-y*blue-scale = 1 + * red-z*red-scale + green-z*green-scale + blue-z*blue-scale + * = (1 - white-x - white-y)/white-y + * + * In the last equation color-z is (1 - color-x - color-y) so we can add all + * three equations together to get an alternative third: + * + * red-scale + green-scale + blue-scale = 1/white-y = white-scale + * + * So now we have a Cramer's rule solution where the determinants are just + * 3x3 - far more tractible. Unfortunately 3x3 determinants still involve + * multiplication of three coefficients so we can't guarantee to avoid + * overflow in the libpng fixed point representation. Using Cramer's rule in + * floating point is probably a good choice here, but it's not an option for + * fixed point. Instead proceed to simplify the first two equations by + * eliminating what is likely to be the largest value, blue-scale: + * + * blue-scale = white-scale - red-scale - green-scale + * + * Hence: + * + * (red-x - blue-x)*red-scale + (green-x - blue-x)*green-scale = + * (white-x - blue-x)*white-scale + * + * (red-y - blue-y)*red-scale + (green-y - blue-y)*green-scale = + * 1 - blue-y*white-scale + * + * And now we can trivially solve for (red-scale,green-scale): + * + * green-scale = + * (white-x - blue-x)*white-scale - (red-x - blue-x)*red-scale + * ----------------------------------------------------------- + * green-x - blue-x + * + * red-scale = + * 1 - blue-y*white-scale - (green-y - blue-y) * green-scale + * --------------------------------------------------------- + * red-y - blue-y + * + * Hence: + * + * red-scale = + * ( (green-x - blue-x) * (white-y - blue-y) - + * (green-y - blue-y) * (white-x - blue-x) ) / white-y + * ------------------------------------------------------------------------- + * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x) + * + * green-scale = + * ( (red-y - blue-y) * (white-x - blue-x) - + * (red-x - blue-x) * (white-y - blue-y) ) / white-y + * ------------------------------------------------------------------------- + * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x) + * + * Accuracy: + * The input values have 5 decimal digits of accuracy. The values are all in + * the range 0 < value < 1, so simple products are in the same range but may + * need up to 10 decimal digits to preserve the original precision and avoid + * underflow. Because we are using a 32-bit signed representation we cannot + * match this; the best is a little over 9 decimal digits, less than 10. + * + * The approach used here is to preserve the maximum precision within the + * signed representation. Because the red-scale calculation above uses the + * difference between two products of values that must be in the range -1..+1 + * it is sufficient to divide the product by 7; ceil(100,000/32767*2). The + * factor is irrelevant in the calculation because it is applied to both + * numerator and denominator. + * + * Note that the values of the differences of the products of the + * chromaticities in the above equations tend to be small, for example for + * the sRGB chromaticities they are: + * + * red numerator: -0.04751 + * green numerator: -0.08788 + * denominator: -0.2241 (without white-y multiplication) + * + * The resultant Y coefficients from the chromaticities of some widely used + * color space definitions are (to 15 decimal places): + * + * sRGB + * 0.212639005871510 0.715168678767756 0.072192315360734 + * Kodak ProPhoto + * 0.288071128229293 0.711843217810102 0.000085653960605 + * Adobe RGB + * 0.297344975250536 0.627363566255466 0.075291458493998 + * Adobe Wide Gamut RGB + * 0.258728243040113 0.724682314948566 0.016589442011321 + */ + /* By the argument, above overflow should be impossible here. The return + * value of 2 indicates an internal error to the caller. + */ + if (png_muldiv(&left, xy->greenx-xy->bluex, xy->redy - xy->bluey, 7) == 0) + return 2; + if (png_muldiv(&right, xy->greeny-xy->bluey, xy->redx - xy->bluex, 7) == 0) + return 2; + denominator = left - right; + + /* Now find the red numerator. */ + if (png_muldiv(&left, xy->greenx-xy->bluex, xy->whitey-xy->bluey, 7) == 0) + return 2; + if (png_muldiv(&right, xy->greeny-xy->bluey, xy->whitex-xy->bluex, 7) == 0) + return 2; + + /* Overflow is possible here and it indicates an extreme set of PNG cHRM + * chunk values. This calculation actually returns the reciprocal of the + * scale value because this allows us to delay the multiplication of white-y + * into the denominator, which tends to produce a small number. + */ + if (png_muldiv(&red_inverse, xy->whitey, denominator, left-right) == 0 || + red_inverse <= xy->whitey /* r+g+b scales = white scale */) + return 1; + + /* Similarly for green_inverse: */ + if (png_muldiv(&left, xy->redy-xy->bluey, xy->whitex-xy->bluex, 7) == 0) + return 2; + if (png_muldiv(&right, xy->redx-xy->bluex, xy->whitey-xy->bluey, 7) == 0) + return 2; + if (png_muldiv(&green_inverse, xy->whitey, denominator, left-right) == 0 || + green_inverse <= xy->whitey) + return 1; + + /* And the blue scale, the checks above guarantee this can't overflow but it + * can still produce 0 for extreme cHRM values. + */ + blue_scale = png_reciprocal(xy->whitey) - png_reciprocal(red_inverse) - + png_reciprocal(green_inverse); + if (blue_scale <= 0) + return 1; + + + /* And fill in the png_XYZ: */ + if (png_muldiv(&XYZ->red_X, xy->redx, PNG_FP_1, red_inverse) == 0) + return 1; + if (png_muldiv(&XYZ->red_Y, xy->redy, PNG_FP_1, red_inverse) == 0) + return 1; + if (png_muldiv(&XYZ->red_Z, PNG_FP_1 - xy->redx - xy->redy, PNG_FP_1, + red_inverse) == 0) + return 1; + + if (png_muldiv(&XYZ->green_X, xy->greenx, PNG_FP_1, green_inverse) == 0) + return 1; + if (png_muldiv(&XYZ->green_Y, xy->greeny, PNG_FP_1, green_inverse) == 0) + return 1; + if (png_muldiv(&XYZ->green_Z, PNG_FP_1 - xy->greenx - xy->greeny, PNG_FP_1, + green_inverse) == 0) + return 1; + + if (png_muldiv(&XYZ->blue_X, xy->bluex, blue_scale, PNG_FP_1) == 0) + return 1; + if (png_muldiv(&XYZ->blue_Y, xy->bluey, blue_scale, PNG_FP_1) == 0) + return 1; + if (png_muldiv(&XYZ->blue_Z, PNG_FP_1 - xy->bluex - xy->bluey, blue_scale, + PNG_FP_1) == 0) + return 1; + + return 0; /*success*/ +} + +static int +png_XYZ_normalize(png_XYZ *XYZ) +{ + png_int_32 Y; + + if (XYZ->red_Y < 0 || XYZ->green_Y < 0 || XYZ->blue_Y < 0 || + XYZ->red_X < 0 || XYZ->green_X < 0 || XYZ->blue_X < 0 || + XYZ->red_Z < 0 || XYZ->green_Z < 0 || XYZ->blue_Z < 0) + return 1; + + /* Normalize by scaling so the sum of the end-point Y values is PNG_FP_1. + * IMPLEMENTATION NOTE: ANSI requires signed overflow not to occur, therefore + * relying on addition of two positive values producing a negative one is not + * safe. + */ + Y = XYZ->red_Y; + if (0x7fffffff - Y < XYZ->green_X) + return 1; + Y += XYZ->green_Y; + if (0x7fffffff - Y < XYZ->blue_X) + return 1; + Y += XYZ->blue_Y; + + if (Y != PNG_FP_1) + { + if (png_muldiv(&XYZ->red_X, XYZ->red_X, PNG_FP_1, Y) == 0) + return 1; + if (png_muldiv(&XYZ->red_Y, XYZ->red_Y, PNG_FP_1, Y) == 0) + return 1; + if (png_muldiv(&XYZ->red_Z, XYZ->red_Z, PNG_FP_1, Y) == 0) + return 1; + + if (png_muldiv(&XYZ->green_X, XYZ->green_X, PNG_FP_1, Y) == 0) + return 1; + if (png_muldiv(&XYZ->green_Y, XYZ->green_Y, PNG_FP_1, Y) == 0) + return 1; + if (png_muldiv(&XYZ->green_Z, XYZ->green_Z, PNG_FP_1, Y) == 0) + return 1; + + if (png_muldiv(&XYZ->blue_X, XYZ->blue_X, PNG_FP_1, Y) == 0) + return 1; + if (png_muldiv(&XYZ->blue_Y, XYZ->blue_Y, PNG_FP_1, Y) == 0) + return 1; + if (png_muldiv(&XYZ->blue_Z, XYZ->blue_Z, PNG_FP_1, Y) == 0) + return 1; + } + + return 0; +} + +static int +png_colorspace_endpoints_match(const png_xy *xy1, const png_xy *xy2, int delta) +{ + /* Allow an error of +/-0.01 (absolute value) on each chromaticity */ + if (PNG_OUT_OF_RANGE(xy1->whitex, xy2->whitex,delta) || + PNG_OUT_OF_RANGE(xy1->whitey, xy2->whitey,delta) || + PNG_OUT_OF_RANGE(xy1->redx, xy2->redx, delta) || + PNG_OUT_OF_RANGE(xy1->redy, xy2->redy, delta) || + PNG_OUT_OF_RANGE(xy1->greenx, xy2->greenx,delta) || + PNG_OUT_OF_RANGE(xy1->greeny, xy2->greeny,delta) || + PNG_OUT_OF_RANGE(xy1->bluex, xy2->bluex, delta) || + PNG_OUT_OF_RANGE(xy1->bluey, xy2->bluey, delta)) + return 0; + return 1; +} + +/* Added in libpng-1.6.0, a different check for the validity of a set of cHRM + * chunk chromaticities. Earlier checks used to simply look for the overflow + * condition (where the determinant of the matrix to solve for XYZ ends up zero + * because the chromaticity values are not all distinct.) Despite this it is + * theoretically possible to produce chromaticities that are apparently valid + * but that rapidly degrade to invalid, potentially crashing, sets because of + * arithmetic inaccuracies when calculations are performed on them. The new + * check is to round-trip xy -> XYZ -> xy and then check that the result is + * within a small percentage of the original. + */ +static int +png_colorspace_check_xy(png_XYZ *XYZ, const png_xy *xy) +{ + int result; + png_xy xy_test; + + /* As a side-effect this routine also returns the XYZ endpoints. */ + result = png_XYZ_from_xy(XYZ, xy); + if (result != 0) + return result; + + result = png_xy_from_XYZ(&xy_test, XYZ); + if (result != 0) + return result; + + if (png_colorspace_endpoints_match(xy, &xy_test, + 5/*actually, the math is pretty accurate*/) != 0) + return 0; + + /* Too much slip */ + return 1; +} + +/* This is the check going the other way. The XYZ is modified to normalize it + * (another side-effect) and the xy chromaticities are returned. + */ +static int +png_colorspace_check_XYZ(png_xy *xy, png_XYZ *XYZ) +{ + int result; + png_XYZ XYZtemp; + + result = png_XYZ_normalize(XYZ); + if (result != 0) + return result; + + result = png_xy_from_XYZ(xy, XYZ); + if (result != 0) + return result; + + XYZtemp = *XYZ; + return png_colorspace_check_xy(&XYZtemp, xy); +} + +/* Used to check for an endpoint match against sRGB */ +static const png_xy sRGB_xy = /* From ITU-R BT.709-3 */ +{ + /* color x y */ + /* red */ 64000, 33000, + /* green */ 30000, 60000, + /* blue */ 15000, 6000, + /* white */ 31270, 32900 +}; + +static int +png_colorspace_set_xy_and_XYZ(png_const_structrp png_ptr, + png_colorspacerp colorspace, const png_xy *xy, const png_XYZ *XYZ, + int preferred) +{ + if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) + return 0; + + /* The consistency check is performed on the chromaticities; this factors out + * variations because of the normalization (or not) of the end point Y + * values. + */ + if (preferred < 2 && + (colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + { + /* The end points must be reasonably close to any we already have. The + * following allows an error of up to +/-.001 + */ + if (png_colorspace_endpoints_match(xy, &colorspace->end_points_xy, + 100) == 0) + { + colorspace->flags |= PNG_COLORSPACE_INVALID; + png_benign_error(png_ptr, "inconsistent chromaticities"); + return 0; /* failed */ + } + + /* Only overwrite with preferred values */ + if (preferred == 0) + return 1; /* ok, but no change */ + } + + colorspace->end_points_xy = *xy; + colorspace->end_points_XYZ = *XYZ; + colorspace->flags |= PNG_COLORSPACE_HAVE_ENDPOINTS; + + /* The end points are normally quoted to two decimal digits, so allow +/-0.01 + * on this test. + */ + if (png_colorspace_endpoints_match(xy, &sRGB_xy, 1000) != 0) + colorspace->flags |= PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB; + + else + colorspace->flags &= PNG_COLORSPACE_CANCEL( + PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB); + + return 2; /* ok and changed */ +} + +int /* PRIVATE */ +png_colorspace_set_chromaticities(png_const_structrp png_ptr, + png_colorspacerp colorspace, const png_xy *xy, int preferred) +{ + /* We must check the end points to ensure they are reasonable - in the past + * color management systems have crashed as a result of getting bogus + * colorant values, while this isn't the fault of libpng it is the + * responsibility of libpng because PNG carries the bomb and libpng is in a + * position to protect against it. + */ + png_XYZ XYZ; + + switch (png_colorspace_check_xy(&XYZ, xy)) + { + case 0: /* success */ + return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, xy, &XYZ, + preferred); + + case 1: + /* We can't invert the chromaticities so we can't produce value XYZ + * values. Likely as not a color management system will fail too. + */ + colorspace->flags |= PNG_COLORSPACE_INVALID; + png_benign_error(png_ptr, "invalid chromaticities"); + break; + + default: + /* libpng is broken; this should be a warning but if it happens we + * want error reports so for the moment it is an error. + */ + colorspace->flags |= PNG_COLORSPACE_INVALID; + png_error(png_ptr, "internal error checking chromaticities"); + } + + return 0; /* failed */ +} + +int /* PRIVATE */ +png_colorspace_set_endpoints(png_const_structrp png_ptr, + png_colorspacerp colorspace, const png_XYZ *XYZ_in, int preferred) +{ + png_XYZ XYZ = *XYZ_in; + png_xy xy; + + switch (png_colorspace_check_XYZ(&xy, &XYZ)) + { + case 0: + return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, &xy, &XYZ, + preferred); + + case 1: + /* End points are invalid. */ + colorspace->flags |= PNG_COLORSPACE_INVALID; + png_benign_error(png_ptr, "invalid end points"); + break; + + default: + colorspace->flags |= PNG_COLORSPACE_INVALID; + png_error(png_ptr, "internal error checking chromaticities"); + } + + return 0; /* failed */ +} + +#if defined(PNG_sRGB_SUPPORTED) || defined(PNG_iCCP_SUPPORTED) +/* Error message generation */ +static char +png_icc_tag_char(png_uint_32 byte) +{ + byte &= 0xff; + if (byte >= 32 && byte <= 126) + return (char)byte; + else + return '?'; +} + +static void +png_icc_tag_name(char *name, png_uint_32 tag) +{ + name[0] = '\''; + name[1] = png_icc_tag_char(tag >> 24); + name[2] = png_icc_tag_char(tag >> 16); + name[3] = png_icc_tag_char(tag >> 8); + name[4] = png_icc_tag_char(tag ); + name[5] = '\''; +} + +static int +is_ICC_signature_char(png_alloc_size_t it) +{ + return it == 32 || (it >= 48 && it <= 57) || (it >= 65 && it <= 90) || + (it >= 97 && it <= 122); +} + +static int +is_ICC_signature(png_alloc_size_t it) +{ + return is_ICC_signature_char(it >> 24) /* checks all the top bits */ && + is_ICC_signature_char((it >> 16) & 0xff) && + is_ICC_signature_char((it >> 8) & 0xff) && + is_ICC_signature_char(it & 0xff); +} + +static int +png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_charp name, png_alloc_size_t value, png_const_charp reason) +{ + size_t pos; + char message[196]; /* see below for calculation */ + + if (colorspace != NULL) + colorspace->flags |= PNG_COLORSPACE_INVALID; + + pos = png_safecat(message, (sizeof message), 0, "profile '"); /* 9 chars */ + pos = png_safecat(message, pos+79, pos, name); /* Truncate to 79 chars */ + pos = png_safecat(message, (sizeof message), pos, "': "); /* +2 = 90 */ + if (is_ICC_signature(value) != 0) + { + /* So 'value' is at most 4 bytes and the following cast is safe */ + png_icc_tag_name(message+pos, (png_uint_32)value); + pos += 6; /* total +8; less than the else clause */ + message[pos++] = ':'; + message[pos++] = ' '; + } +# ifdef PNG_WARNINGS_SUPPORTED + else + { + char number[PNG_NUMBER_BUFFER_SIZE]; /* +24 = 114*/ + + pos = png_safecat(message, (sizeof message), pos, + png_format_number(number, number+(sizeof number), + PNG_NUMBER_FORMAT_x, value)); + pos = png_safecat(message, (sizeof message), pos, "h: "); /*+2 = 116*/ + } +# endif + /* The 'reason' is an arbitrary message, allow +79 maximum 195 */ + pos = png_safecat(message, (sizeof message), pos, reason); + PNG_UNUSED(pos) + + /* This is recoverable, but make it unconditionally an app_error on write to + * avoid writing invalid ICC profiles into PNG files (i.e., we handle them + * on read, with a warning, but on write unless the app turns off + * application errors the PNG won't be written.) + */ + png_chunk_report(png_ptr, message, + (colorspace != NULL) ? PNG_CHUNK_ERROR : PNG_CHUNK_WRITE_ERROR); + + return 0; +} +#endif /* sRGB || iCCP */ + +#ifdef PNG_sRGB_SUPPORTED +int /* PRIVATE */ +png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace, + int intent) +{ + /* sRGB sets known gamma, end points and (from the chunk) intent. */ + /* IMPORTANT: these are not necessarily the values found in an ICC profile + * because ICC profiles store values adapted to a D50 environment; it is + * expected that the ICC profile mediaWhitePointTag will be D50; see the + * checks and code elsewhere to understand this better. + * + * These XYZ values, which are accurate to 5dp, produce rgb to gray + * coefficients of (6968,23435,2366), which are reduced (because they add up + * to 32769 not 32768) to (6968,23434,2366). These are the values that + * libpng has traditionally used (and are the best values given the 15bit + * algorithm used by the rgb to gray code.) + */ + static const png_XYZ sRGB_XYZ = /* D65 XYZ (*not* the D50 adapted values!) */ + { + /* color X Y Z */ + /* red */ 41239, 21264, 1933, + /* green */ 35758, 71517, 11919, + /* blue */ 18048, 7219, 95053 + }; + + /* Do nothing if the colorspace is already invalidated. */ + if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) + return 0; + + /* Check the intent, then check for existing settings. It is valid for the + * PNG file to have cHRM or gAMA chunks along with sRGB, but the values must + * be consistent with the correct values. If, however, this function is + * called below because an iCCP chunk matches sRGB then it is quite + * conceivable that an older app recorded incorrect gAMA and cHRM because of + * an incorrect calculation based on the values in the profile - this does + * *not* invalidate the profile (though it still produces an error, which can + * be ignored.) + */ + if (intent < 0 || intent >= PNG_sRGB_INTENT_LAST) + return png_icc_profile_error(png_ptr, colorspace, "sRGB", + (png_alloc_size_t)intent, "invalid sRGB rendering intent"); + + if ((colorspace->flags & PNG_COLORSPACE_HAVE_INTENT) != 0 && + colorspace->rendering_intent != intent) + return png_icc_profile_error(png_ptr, colorspace, "sRGB", + (png_alloc_size_t)intent, "inconsistent rendering intents"); + + if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0) + { + png_benign_error(png_ptr, "duplicate sRGB information ignored"); + return 0; + } + + /* If the standard sRGB cHRM chunk does not match the one from the PNG file + * warn but overwrite the value with the correct one. + */ + if ((colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0 && + !png_colorspace_endpoints_match(&sRGB_xy, &colorspace->end_points_xy, + 100)) + png_chunk_report(png_ptr, "cHRM chunk does not match sRGB", + PNG_CHUNK_ERROR); + + /* This check is just done for the error reporting - the routine always + * returns true when the 'from' argument corresponds to sRGB (2). + */ + (void)png_colorspace_check_gamma(png_ptr, colorspace, PNG_GAMMA_sRGB_INVERSE, + 2/*from sRGB*/); + + /* intent: bugs in GCC force 'int' to be used as the parameter type. */ + colorspace->rendering_intent = (png_uint_16)intent; + colorspace->flags |= PNG_COLORSPACE_HAVE_INTENT; + + /* endpoints */ + colorspace->end_points_xy = sRGB_xy; + colorspace->end_points_XYZ = sRGB_XYZ; + colorspace->flags |= + (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB); + + /* gamma */ + colorspace->gamma = PNG_GAMMA_sRGB_INVERSE; + colorspace->flags |= PNG_COLORSPACE_HAVE_GAMMA; + + /* Finally record that we have an sRGB profile */ + colorspace->flags |= + (PNG_COLORSPACE_MATCHES_sRGB|PNG_COLORSPACE_FROM_sRGB); + + return 1; /* set */ +} +#endif /* sRGB */ + +#ifdef PNG_iCCP_SUPPORTED +/* Encoded value of D50 as an ICC XYZNumber. From the ICC 2010 spec the value + * is XYZ(0.9642,1.0,0.8249), which scales to: + * + * (63189.8112, 65536, 54060.6464) + */ +static const png_byte D50_nCIEXYZ[12] = + { 0x00, 0x00, 0xf6, 0xd6, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0xd3, 0x2d }; + +static int /* bool */ +icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_charp name, png_uint_32 profile_length) +{ + if (profile_length < 132) + return png_icc_profile_error(png_ptr, colorspace, name, profile_length, + "too short"); + return 1; +} + +#ifdef PNG_READ_iCCP_SUPPORTED +int /* PRIVATE */ +png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_charp name, png_uint_32 profile_length) +{ + if (!icc_check_length(png_ptr, colorspace, name, profile_length)) + return 0; + + /* This needs to be here because the 'normal' check is in + * png_decompress_chunk, yet this happens after the attempt to + * png_malloc_base the required data. We only need this on read; on write + * the caller supplies the profile buffer so libpng doesn't allocate it. See + * the call to icc_check_length below (the write case). + */ +# ifdef PNG_SET_USER_LIMITS_SUPPORTED + else if (png_ptr->user_chunk_malloc_max > 0 && + png_ptr->user_chunk_malloc_max < profile_length) + return png_icc_profile_error(png_ptr, colorspace, name, profile_length, + "exceeds application limits"); +# elif PNG_USER_CHUNK_MALLOC_MAX > 0 + else if (PNG_USER_CHUNK_MALLOC_MAX < profile_length) + return png_icc_profile_error(png_ptr, colorspace, name, profile_length, + "exceeds libpng limits"); +# else /* !SET_USER_LIMITS */ + /* This will get compiled out on all 32-bit and better systems. */ + else if (PNG_SIZE_MAX < profile_length) + return png_icc_profile_error(png_ptr, colorspace, name, profile_length, + "exceeds system limits"); +# endif /* !SET_USER_LIMITS */ + + return 1; +} +#endif /* READ_iCCP */ + +int /* PRIVATE */ +png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_charp name, png_uint_32 profile_length, + png_const_bytep profile/* first 132 bytes only */, int color_type) +{ + png_uint_32 temp; + + /* Length check; this cannot be ignored in this code because profile_length + * is used later to check the tag table, so even if the profile seems over + * long profile_length from the caller must be correct. The caller can fix + * this up on read or write by just passing in the profile header length. + */ + temp = png_get_uint_32(profile); + if (temp != profile_length) + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "length does not match profile"); + + temp = (png_uint_32) (*(profile+8)); + if (temp > 3 && (profile_length & 3)) + return png_icc_profile_error(png_ptr, colorspace, name, profile_length, + "invalid length"); + + temp = png_get_uint_32(profile+128); /* tag count: 12 bytes/tag */ + if (temp > 357913930 || /* (2^32-4-132)/12: maximum possible tag count */ + profile_length < 132+12*temp) /* truncated tag table */ + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "tag count too large"); + + /* The 'intent' must be valid or we can't store it, ICC limits the intent to + * 16 bits. + */ + temp = png_get_uint_32(profile+64); + if (temp >= 0xffff) /* The ICC limit */ + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "invalid rendering intent"); + + /* This is just a warning because the profile may be valid in future + * versions. + */ + if (temp >= PNG_sRGB_INTENT_LAST) + (void)png_icc_profile_error(png_ptr, NULL, name, temp, + "intent outside defined range"); + + /* At this point the tag table can't be checked because it hasn't necessarily + * been loaded; however, various header fields can be checked. These checks + * are for values permitted by the PNG spec in an ICC profile; the PNG spec + * restricts the profiles that can be passed in an iCCP chunk (they must be + * appropriate to processing PNG data!) + */ + + /* Data checks (could be skipped). These checks must be independent of the + * version number; however, the version number doesn't accommodate changes in + * the header fields (just the known tags and the interpretation of the + * data.) + */ + temp = png_get_uint_32(profile+36); /* signature 'ascp' */ + if (temp != 0x61637370) + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "invalid signature"); + + /* Currently the PCS illuminant/adopted white point (the computational + * white point) are required to be D50, + * however the profile contains a record of the illuminant so perhaps ICC + * expects to be able to change this in the future (despite the rationale in + * the introduction for using a fixed PCS adopted white.) Consequently the + * following is just a warning. + */ + if (memcmp(profile+68, D50_nCIEXYZ, 12) != 0) + (void)png_icc_profile_error(png_ptr, NULL, name, 0/*no tag value*/, + "PCS illuminant is not D50"); + + /* The PNG spec requires this: + * "If the iCCP chunk is present, the image samples conform to the colour + * space represented by the embedded ICC profile as defined by the + * International Color Consortium [ICC]. The colour space of the ICC profile + * shall be an RGB colour space for colour images (PNG colour types 2, 3, and + * 6), or a greyscale colour space for greyscale images (PNG colour types 0 + * and 4)." + * + * This checking code ensures the embedded profile (on either read or write) + * conforms to the specification requirements. Notice that an ICC 'gray' + * color-space profile contains the information to transform the monochrome + * data to XYZ or L*a*b (according to which PCS the profile uses) and this + * should be used in preference to the standard libpng K channel replication + * into R, G and B channels. + * + * Previously it was suggested that an RGB profile on grayscale data could be + * handled. However it it is clear that using an RGB profile in this context + * must be an error - there is no specification of what it means. Thus it is + * almost certainly more correct to ignore the profile. + */ + temp = png_get_uint_32(profile+16); /* data colour space field */ + switch (temp) + { + case 0x52474220: /* 'RGB ' */ + if ((color_type & PNG_COLOR_MASK_COLOR) == 0) + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "RGB color space not permitted on grayscale PNG"); + break; + + case 0x47524159: /* 'GRAY' */ + if ((color_type & PNG_COLOR_MASK_COLOR) != 0) + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "Gray color space not permitted on RGB PNG"); + break; + + default: + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "invalid ICC profile color space"); + } + + /* It is up to the application to check that the profile class matches the + * application requirements; the spec provides no guidance, but it's pretty + * weird if the profile is not scanner ('scnr'), monitor ('mntr'), printer + * ('prtr') or 'spac' (for generic color spaces). Issue a warning in these + * cases. Issue an error for device link or abstract profiles - these don't + * contain the records necessary to transform the color-space to anything + * other than the target device (and not even that for an abstract profile). + * Profiles of these classes may not be embedded in images. + */ + temp = png_get_uint_32(profile+12); /* profile/device class */ + switch (temp) + { + case 0x73636e72: /* 'scnr' */ + case 0x6d6e7472: /* 'mntr' */ + case 0x70727472: /* 'prtr' */ + case 0x73706163: /* 'spac' */ + /* All supported */ + break; + + case 0x61627374: /* 'abst' */ + /* May not be embedded in an image */ + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "invalid embedded Abstract ICC profile"); + + case 0x6c696e6b: /* 'link' */ + /* DeviceLink profiles cannot be interpreted in a non-device specific + * fashion, if an app uses the AToB0Tag in the profile the results are + * undefined unless the result is sent to the intended device, + * therefore a DeviceLink profile should not be found embedded in a + * PNG. + */ + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "unexpected DeviceLink ICC profile class"); + + case 0x6e6d636c: /* 'nmcl' */ + /* A NamedColor profile is also device specific, however it doesn't + * contain an AToB0 tag that is open to misinterpretation. Almost + * certainly it will fail the tests below. + */ + (void)png_icc_profile_error(png_ptr, NULL, name, temp, + "unexpected NamedColor ICC profile class"); + break; + + default: + /* To allow for future enhancements to the profile accept unrecognized + * profile classes with a warning, these then hit the test below on the + * tag content to ensure they are backward compatible with one of the + * understood profiles. + */ + (void)png_icc_profile_error(png_ptr, NULL, name, temp, + "unrecognized ICC profile class"); + break; + } + + /* For any profile other than a device link one the PCS must be encoded + * either in XYZ or Lab. + */ + temp = png_get_uint_32(profile+20); + switch (temp) + { + case 0x58595a20: /* 'XYZ ' */ + case 0x4c616220: /* 'Lab ' */ + break; + + default: + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "unexpected ICC PCS encoding"); + } + + return 1; +} + +int /* PRIVATE */ +png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_charp name, png_uint_32 profile_length, + png_const_bytep profile /* header plus whole tag table */) +{ + png_uint_32 tag_count = png_get_uint_32(profile+128); + png_uint_32 itag; + png_const_bytep tag = profile+132; /* The first tag */ + + /* First scan all the tags in the table and add bits to the icc_info value + * (temporarily in 'tags'). + */ + for (itag=0; itag < tag_count; ++itag, tag += 12) + { + png_uint_32 tag_id = png_get_uint_32(tag+0); + png_uint_32 tag_start = png_get_uint_32(tag+4); /* must be aligned */ + png_uint_32 tag_length = png_get_uint_32(tag+8);/* not padded */ + + /* The ICC specification does not exclude zero length tags, therefore the + * start might actually be anywhere if there is no data, but this would be + * a clear abuse of the intent of the standard so the start is checked for + * being in range. All defined tag types have an 8 byte header - a 4 byte + * type signature then 0. + */ + + /* This is a hard error; potentially it can cause read outside the + * profile. + */ + if (tag_start > profile_length || tag_length > profile_length - tag_start) + return png_icc_profile_error(png_ptr, colorspace, name, tag_id, + "ICC profile tag outside profile"); + + if ((tag_start & 3) != 0) + { + /* CNHP730S.icc shipped with Microsoft Windows 64 violates this; it is + * only a warning here because libpng does not care about the + * alignment. + */ + (void)png_icc_profile_error(png_ptr, NULL, name, tag_id, + "ICC profile tag start not a multiple of 4"); + } + } + + return 1; /* success, maybe with warnings */ +} + +#ifdef PNG_sRGB_SUPPORTED +#if PNG_sRGB_PROFILE_CHECKS >= 0 +/* Information about the known ICC sRGB profiles */ +static const struct +{ + png_uint_32 adler, crc, length; + png_uint_32 md5[4]; + png_byte have_md5; + png_byte is_broken; + png_uint_16 intent; + +# define PNG_MD5(a,b,c,d) { a, b, c, d }, (a!=0)||(b!=0)||(c!=0)||(d!=0) +# define PNG_ICC_CHECKSUM(adler, crc, md5, intent, broke, date, length, fname)\ + { adler, crc, length, md5, broke, intent }, + +} png_sRGB_checks[] = +{ + /* This data comes from contrib/tools/checksum-icc run on downloads of + * all four ICC sRGB profiles from www.color.org. + */ + /* adler32, crc32, MD5[4], intent, date, length, file-name */ + PNG_ICC_CHECKSUM(0x0a3fd9f6, 0x3b8772b9, + PNG_MD5(0x29f83dde, 0xaff255ae, 0x7842fae4, 0xca83390d), 0, 0, + "2009/03/27 21:36:31", 3048, "sRGB_IEC61966-2-1_black_scaled.icc") + + /* ICC sRGB v2 perceptual no black-compensation: */ + PNG_ICC_CHECKSUM(0x4909e5e1, 0x427ebb21, + PNG_MD5(0xc95bd637, 0xe95d8a3b, 0x0df38f99, 0xc1320389), 1, 0, + "2009/03/27 21:37:45", 3052, "sRGB_IEC61966-2-1_no_black_scaling.icc") + + PNG_ICC_CHECKSUM(0xfd2144a1, 0x306fd8ae, + PNG_MD5(0xfc663378, 0x37e2886b, 0xfd72e983, 0x8228f1b8), 0, 0, + "2009/08/10 17:28:01", 60988, "sRGB_v4_ICC_preference_displayclass.icc") + + /* ICC sRGB v4 perceptual */ + PNG_ICC_CHECKSUM(0x209c35d2, 0xbbef7812, + PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, 0, + "2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc") + + /* The following profiles have no known MD5 checksum. If there is a match + * on the (empty) MD5 the other fields are used to attempt a match and + * a warning is produced. The first two of these profiles have a 'cprt' tag + * which suggests that they were also made by Hewlett Packard. + */ + PNG_ICC_CHECKSUM(0xa054d762, 0x5d5129ce, + PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 0, + "2004/07/21 18:57:42", 3024, "sRGB_IEC61966-2-1_noBPC.icc") + + /* This is a 'mntr' (display) profile with a mediaWhitePointTag that does not + * match the D50 PCS illuminant in the header (it is in fact the D65 values, + * so the white point is recorded as the un-adapted value.) The profiles + * below only differ in one byte - the intent - and are basically the same as + * the previous profile except for the mediaWhitePointTag error and a missing + * chromaticAdaptationTag. + */ + PNG_ICC_CHECKSUM(0xf784f3fb, 0x182ea552, + PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 0, 1/*broken*/, + "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 perceptual") + + PNG_ICC_CHECKSUM(0x0398f3fc, 0xf29e526d, + PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 1/*broken*/, + "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 media-relative") +}; + +static int +png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr, + png_const_bytep profile, uLong adler) +{ + /* The quick check is to verify just the MD5 signature and trust the + * rest of the data. Because the profile has already been verified for + * correctness this is safe. png_colorspace_set_sRGB will check the 'intent' + * field too, so if the profile has been edited with an intent not defined + * by sRGB (but maybe defined by a later ICC specification) the read of + * the profile will fail at that point. + */ + + png_uint_32 length = 0; + png_uint_32 intent = 0x10000; /* invalid */ +#if PNG_sRGB_PROFILE_CHECKS > 1 + uLong crc = 0; /* the value for 0 length data */ +#endif + unsigned int i; + +#ifdef PNG_SET_OPTION_SUPPORTED + /* First see if PNG_SKIP_sRGB_CHECK_PROFILE has been set to "on" */ + if (((png_ptr->options >> PNG_SKIP_sRGB_CHECK_PROFILE) & 3) == + PNG_OPTION_ON) + return 0; +#endif + + for (i=0; i < (sizeof png_sRGB_checks) / (sizeof png_sRGB_checks[0]); ++i) + { + if (png_get_uint_32(profile+84) == png_sRGB_checks[i].md5[0] && + png_get_uint_32(profile+88) == png_sRGB_checks[i].md5[1] && + png_get_uint_32(profile+92) == png_sRGB_checks[i].md5[2] && + png_get_uint_32(profile+96) == png_sRGB_checks[i].md5[3]) + { + /* This may be one of the old HP profiles without an MD5, in that + * case we can only use the length and Adler32 (note that these + * are not used by default if there is an MD5!) + */ +# if PNG_sRGB_PROFILE_CHECKS == 0 + if (png_sRGB_checks[i].have_md5 != 0) + return 1+png_sRGB_checks[i].is_broken; +# endif + + /* Profile is unsigned or more checks have been configured in. */ + if (length == 0) + { + length = png_get_uint_32(profile); + intent = png_get_uint_32(profile+64); + } + + /* Length *and* intent must match */ + if (length == (png_uint_32) png_sRGB_checks[i].length && + intent == (png_uint_32) png_sRGB_checks[i].intent) + { + /* Now calculate the adler32 if not done already. */ + if (adler == 0) + { + adler = adler32(0, NULL, 0); + adler = adler32(adler, profile, length); + } + + if (adler == png_sRGB_checks[i].adler) + { + /* These basic checks suggest that the data has not been + * modified, but if the check level is more than 1 perform + * our own crc32 checksum on the data. + */ +# if PNG_sRGB_PROFILE_CHECKS > 1 + if (crc == 0) + { + crc = crc32(0, NULL, 0); + crc = crc32(crc, profile, length); + } + + /* So this check must pass for the 'return' below to happen. + */ + if (crc == png_sRGB_checks[i].crc) +# endif + { + if (png_sRGB_checks[i].is_broken != 0) + { + /* These profiles are known to have bad data that may cause + * problems if they are used, therefore attempt to + * discourage their use, skip the 'have_md5' warning below, + * which is made irrelevant by this error. + */ + png_chunk_report(png_ptr, "known incorrect sRGB profile", + PNG_CHUNK_ERROR); + } + + /* Warn that this being done; this isn't even an error since + * the profile is perfectly valid, but it would be nice if + * people used the up-to-date ones. + */ + else if (png_sRGB_checks[i].have_md5 == 0) + { + png_chunk_report(png_ptr, + "out-of-date sRGB profile with no signature", + PNG_CHUNK_WARNING); + } + + return 1+png_sRGB_checks[i].is_broken; + } + } + +# if PNG_sRGB_PROFILE_CHECKS > 0 + /* The signature matched, but the profile had been changed in some + * way. This probably indicates a data error or uninformed hacking. + * Fall through to "no match". + */ + png_chunk_report(png_ptr, + "Not recognizing known sRGB profile that has been edited", + PNG_CHUNK_WARNING); + break; +# endif + } + } + } + + return 0; /* no match */ +} + +void /* PRIVATE */ +png_icc_set_sRGB(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_const_bytep profile, uLong adler) +{ + /* Is this profile one of the known ICC sRGB profiles? If it is, just set + * the sRGB information. + */ + if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler) != 0) + (void)png_colorspace_set_sRGB(png_ptr, colorspace, + (int)/*already checked*/png_get_uint_32(profile+64)); +} +#endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */ +#endif /* sRGB */ + +int /* PRIVATE */ +png_colorspace_set_ICC(png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_charp name, png_uint_32 profile_length, png_const_bytep profile, + int color_type) +{ + if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) + return 0; + + if (icc_check_length(png_ptr, colorspace, name, profile_length) != 0 && + png_icc_check_header(png_ptr, colorspace, name, profile_length, profile, + color_type) != 0 && + png_icc_check_tag_table(png_ptr, colorspace, name, profile_length, + profile) != 0) + { +# if defined(PNG_sRGB_SUPPORTED) && PNG_sRGB_PROFILE_CHECKS >= 0 + /* If no sRGB support, don't try storing sRGB information */ + png_icc_set_sRGB(png_ptr, colorspace, profile, 0); +# endif + return 1; + } + + /* Failure case */ + return 0; +} +#endif /* iCCP */ + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +void /* PRIVATE */ +png_colorspace_set_rgb_coefficients(png_structrp png_ptr) +{ + /* Set the rgb_to_gray coefficients from the colorspace. */ + if (png_ptr->rgb_to_gray_coefficients_set == 0 && + (png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + { + /* png_set_background has not been called, get the coefficients from the Y + * values of the colorspace colorants. + */ + png_fixed_point r = png_ptr->colorspace.end_points_XYZ.red_Y; + png_fixed_point g = png_ptr->colorspace.end_points_XYZ.green_Y; + png_fixed_point b = png_ptr->colorspace.end_points_XYZ.blue_Y; + png_fixed_point total = r+g+b; + + if (total > 0 && + r >= 0 && png_muldiv(&r, r, 32768, total) && r >= 0 && r <= 32768 && + g >= 0 && png_muldiv(&g, g, 32768, total) && g >= 0 && g <= 32768 && + b >= 0 && png_muldiv(&b, b, 32768, total) && b >= 0 && b <= 32768 && + r+g+b <= 32769) + { + /* We allow 0 coefficients here. r+g+b may be 32769 if two or + * all of the coefficients were rounded up. Handle this by + * reducing the *largest* coefficient by 1; this matches the + * approach used for the default coefficients in pngrtran.c + */ + int add = 0; + + if (r+g+b > 32768) + add = -1; + else if (r+g+b < 32768) + add = 1; + + if (add != 0) + { + if (g >= r && g >= b) + g += add; + else if (r >= g && r >= b) + r += add; + else + b += add; + } + + /* Check for an internal error. */ + if (r+g+b != 32768) + png_error(png_ptr, + "internal error handling cHRM coefficients"); + + else + { + png_ptr->rgb_to_gray_red_coeff = (png_uint_16)r; + png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g; + } + } + + /* This is a png_error at present even though it could be ignored - + * it should never happen, but it is important that if it does, the + * bug is fixed. + */ + else + png_error(png_ptr, "internal error handling cHRM->XYZ"); + } +} +#endif /* READ_RGB_TO_GRAY */ + +#endif /* COLORSPACE */ + +#ifdef __GNUC__ +/* This exists solely to work round a warning from GNU C. */ +static int /* PRIVATE */ +png_gt(size_t a, size_t b) +{ + return a > b; +} +#else +# define png_gt(a,b) ((a) > (b)) +#endif + +void /* PRIVATE */ +png_check_IHDR(png_const_structrp png_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_type, int compression_type, + int filter_type) +{ + int error = 0; + + /* Check for width and height valid values */ + if (width == 0) + { + png_warning(png_ptr, "Image width is zero in IHDR"); + error = 1; + } + + if (width > PNG_UINT_31_MAX) + { + png_warning(png_ptr, "Invalid image width in IHDR"); + error = 1; + } + + if (png_gt(((width + 7) & (~7U)), + ((PNG_SIZE_MAX + - 48 /* big_row_buf hack */ + - 1) /* filter byte */ + / 8) /* 8-byte RGBA pixels */ + - 1)) /* extra max_pixel_depth pad */ + { + /* The size of the row must be within the limits of this architecture. + * Because the read code can perform arbitrary transformations the + * maximum size is checked here. Because the code in png_read_start_row + * adds extra space "for safety's sake" in several places a conservative + * limit is used here. + * + * NOTE: it would be far better to check the size that is actually used, + * but the effect in the real world is minor and the changes are more + * extensive, therefore much more dangerous and much more difficult to + * write in a way that avoids compiler warnings. + */ + png_warning(png_ptr, "Image width is too large for this architecture"); + error = 1; + } + +#ifdef PNG_SET_USER_LIMITS_SUPPORTED + if (width > png_ptr->user_width_max) +#else + if (width > PNG_USER_WIDTH_MAX) +#endif + { + png_warning(png_ptr, "Image width exceeds user limit in IHDR"); + error = 1; + } + + if (height == 0) + { + png_warning(png_ptr, "Image height is zero in IHDR"); + error = 1; + } + + if (height > PNG_UINT_31_MAX) + { + png_warning(png_ptr, "Invalid image height in IHDR"); + error = 1; + } + +#ifdef PNG_SET_USER_LIMITS_SUPPORTED + if (height > png_ptr->user_height_max) +#else + if (height > PNG_USER_HEIGHT_MAX) +#endif + { + png_warning(png_ptr, "Image height exceeds user limit in IHDR"); + error = 1; + } + + /* Check other values */ + if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 && + bit_depth != 8 && bit_depth != 16) + { + png_warning(png_ptr, "Invalid bit depth in IHDR"); + error = 1; + } + + if (color_type < 0 || color_type == 1 || + color_type == 5 || color_type > 6) + { + png_warning(png_ptr, "Invalid color type in IHDR"); + error = 1; + } + + if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) || + ((color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8)) + { + png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR"); + error = 1; + } + + if (interlace_type >= PNG_INTERLACE_LAST) + { + png_warning(png_ptr, "Unknown interlace method in IHDR"); + error = 1; + } + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + { + png_warning(png_ptr, "Unknown compression method in IHDR"); + error = 1; + } + +#ifdef PNG_MNG_FEATURES_SUPPORTED + /* Accept filter_method 64 (intrapixel differencing) only if + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and + * 2. Libpng did not read a PNG signature (this filter_method is only + * used in PNG datastreams that are embedded in MNG datastreams) and + * 3. The application called png_permit_mng_features with a mask that + * included PNG_FLAG_MNG_FILTER_64 and + * 4. The filter_method is 64 and + * 5. The color_type is RGB or RGBA + */ + if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && + png_ptr->mng_features_permitted != 0) + png_warning(png_ptr, "MNG features are not allowed in a PNG datastream"); + + if (filter_type != PNG_FILTER_TYPE_BASE) + { + if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && + (filter_type == PNG_INTRAPIXEL_DIFFERENCING) && + ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) && + (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA))) + { + png_warning(png_ptr, "Unknown filter method in IHDR"); + error = 1; + } + + if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0) + { + png_warning(png_ptr, "Invalid filter method in IHDR"); + error = 1; + } + } + +#else + if (filter_type != PNG_FILTER_TYPE_BASE) + { + png_warning(png_ptr, "Unknown filter method in IHDR"); + error = 1; + } +#endif + + if (error == 1) + png_error(png_ptr, "Invalid IHDR data"); +} + +#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) +/* ASCII to fp functions */ +/* Check an ASCII formatted floating point value, see the more detailed + * comments in pngpriv.h + */ +/* The following is used internally to preserve the sticky flags */ +#define png_fp_add(state, flags) ((state) |= (flags)) +#define png_fp_set(state, value) ((state) = (value) | ((state) & PNG_FP_STICKY)) + +int /* PRIVATE */ +png_check_fp_number(png_const_charp string, size_t size, int *statep, + png_size_tp whereami) +{ + int state = *statep; + size_t i = *whereami; + + while (i < size) + { + int type; + /* First find the type of the next character */ + switch (string[i]) + { + case 43: type = PNG_FP_SAW_SIGN; break; + case 45: type = PNG_FP_SAW_SIGN + PNG_FP_NEGATIVE; break; + case 46: type = PNG_FP_SAW_DOT; break; + case 48: type = PNG_FP_SAW_DIGIT; break; + case 49: case 50: case 51: case 52: + case 53: case 54: case 55: case 56: + case 57: type = PNG_FP_SAW_DIGIT + PNG_FP_NONZERO; break; + case 69: + case 101: type = PNG_FP_SAW_E; break; + default: goto PNG_FP_End; + } + + /* Now deal with this type according to the current + * state, the type is arranged to not overlap the + * bits of the PNG_FP_STATE. + */ + switch ((state & PNG_FP_STATE) + (type & PNG_FP_SAW_ANY)) + { + case PNG_FP_INTEGER + PNG_FP_SAW_SIGN: + if ((state & PNG_FP_SAW_ANY) != 0) + goto PNG_FP_End; /* not a part of the number */ + + png_fp_add(state, type); + break; + + case PNG_FP_INTEGER + PNG_FP_SAW_DOT: + /* Ok as trailer, ok as lead of fraction. */ + if ((state & PNG_FP_SAW_DOT) != 0) /* two dots */ + goto PNG_FP_End; + + else if ((state & PNG_FP_SAW_DIGIT) != 0) /* trailing dot? */ + png_fp_add(state, type); + + else + png_fp_set(state, PNG_FP_FRACTION | type); + + break; + + case PNG_FP_INTEGER + PNG_FP_SAW_DIGIT: + if ((state & PNG_FP_SAW_DOT) != 0) /* delayed fraction */ + png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT); + + png_fp_add(state, type | PNG_FP_WAS_VALID); + + break; + + case PNG_FP_INTEGER + PNG_FP_SAW_E: + if ((state & PNG_FP_SAW_DIGIT) == 0) + goto PNG_FP_End; + + png_fp_set(state, PNG_FP_EXPONENT); + + break; + + /* case PNG_FP_FRACTION + PNG_FP_SAW_SIGN: + goto PNG_FP_End; ** no sign in fraction */ + + /* case PNG_FP_FRACTION + PNG_FP_SAW_DOT: + goto PNG_FP_End; ** Because SAW_DOT is always set */ + + case PNG_FP_FRACTION + PNG_FP_SAW_DIGIT: + png_fp_add(state, type | PNG_FP_WAS_VALID); + break; + + case PNG_FP_FRACTION + PNG_FP_SAW_E: + /* This is correct because the trailing '.' on an + * integer is handled above - so we can only get here + * with the sequence ".E" (with no preceding digits). + */ + if ((state & PNG_FP_SAW_DIGIT) == 0) + goto PNG_FP_End; + + png_fp_set(state, PNG_FP_EXPONENT); + + break; + + case PNG_FP_EXPONENT + PNG_FP_SAW_SIGN: + if ((state & PNG_FP_SAW_ANY) != 0) + goto PNG_FP_End; /* not a part of the number */ + + png_fp_add(state, PNG_FP_SAW_SIGN); + + break; + + /* case PNG_FP_EXPONENT + PNG_FP_SAW_DOT: + goto PNG_FP_End; */ + + case PNG_FP_EXPONENT + PNG_FP_SAW_DIGIT: + png_fp_add(state, PNG_FP_SAW_DIGIT | PNG_FP_WAS_VALID); + + break; + + /* case PNG_FP_EXPONEXT + PNG_FP_SAW_E: + goto PNG_FP_End; */ + + default: goto PNG_FP_End; /* I.e. break 2 */ + } + + /* The character seems ok, continue. */ + ++i; + } + +PNG_FP_End: + /* Here at the end, update the state and return the correct + * return code. + */ + *statep = state; + *whereami = i; + + return (state & PNG_FP_SAW_DIGIT) != 0; +} + + +/* The same but for a complete string. */ +int +png_check_fp_string(png_const_charp string, size_t size) +{ + int state=0; + size_t char_index=0; + + if (png_check_fp_number(string, size, &state, &char_index) != 0 && + (char_index == size || string[char_index] == 0)) + return state /* must be non-zero - see above */; + + return 0; /* i.e. fail */ +} +#endif /* pCAL || sCAL */ + +#ifdef PNG_sCAL_SUPPORTED +# ifdef PNG_FLOATING_POINT_SUPPORTED +/* Utility used below - a simple accurate power of ten from an integral + * exponent. + */ +static double +png_pow10(int power) +{ + int recip = 0; + double d = 1; + + /* Handle negative exponent with a reciprocal at the end because + * 10 is exact whereas .1 is inexact in base 2 + */ + if (power < 0) + { + if (power < DBL_MIN_10_EXP) return 0; + recip = 1; power = -power; + } + + if (power > 0) + { + /* Decompose power bitwise. */ + double mult = 10; + do + { + if (power & 1) d *= mult; + mult *= mult; + power >>= 1; + } + while (power > 0); + + if (recip != 0) d = 1/d; + } + /* else power is 0 and d is 1 */ + + return d; +} + +/* Function to format a floating point value in ASCII with a given + * precision. + */ +#if GCC_STRICT_OVERFLOW +#pragma GCC diagnostic push +/* The problem arises below with exp_b10, which can never overflow because it + * comes, originally, from frexp and is therefore limited to a range which is + * typically +/-710 (log2(DBL_MAX)/log2(DBL_MIN)). + */ +#pragma GCC diagnostic warning "-Wstrict-overflow=2" +#endif /* GCC_STRICT_OVERFLOW */ +void /* PRIVATE */ +png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, size_t size, + double fp, unsigned int precision) +{ + /* We use standard functions from math.h, but not printf because + * that would require stdio. The caller must supply a buffer of + * sufficient size or we will png_error. The tests on size and + * the space in ascii[] consumed are indicated below. + */ + if (precision < 1) + precision = DBL_DIG; + + /* Enforce the limit of the implementation precision too. */ + if (precision > DBL_DIG+1) + precision = DBL_DIG+1; + + /* Basic sanity checks */ + if (size >= precision+5) /* See the requirements below. */ + { + if (fp < 0) + { + fp = -fp; + *ascii++ = 45; /* '-' PLUS 1 TOTAL 1 */ + --size; + } + + if (fp >= DBL_MIN && fp <= DBL_MAX) + { + int exp_b10; /* A base 10 exponent */ + double base; /* 10^exp_b10 */ + + /* First extract a base 10 exponent of the number, + * the calculation below rounds down when converting + * from base 2 to base 10 (multiply by log10(2) - + * 0.3010, but 77/256 is 0.3008, so exp_b10 needs to + * be increased. Note that the arithmetic shift + * performs a floor() unlike C arithmetic - using a + * C multiply would break the following for negative + * exponents. + */ + (void)frexp(fp, &exp_b10); /* exponent to base 2 */ + + exp_b10 = (exp_b10 * 77) >> 8; /* <= exponent to base 10 */ + + /* Avoid underflow here. */ + base = png_pow10(exp_b10); /* May underflow */ + + while (base < DBL_MIN || base < fp) + { + /* And this may overflow. */ + double test = png_pow10(exp_b10+1); + + if (test <= DBL_MAX) + { + ++exp_b10; base = test; + } + + else + break; + } + + /* Normalize fp and correct exp_b10, after this fp is in the + * range [.1,1) and exp_b10 is both the exponent and the digit + * *before* which the decimal point should be inserted + * (starting with 0 for the first digit). Note that this + * works even if 10^exp_b10 is out of range because of the + * test on DBL_MAX above. + */ + fp /= base; + while (fp >= 1) + { + fp /= 10; ++exp_b10; + } + + /* Because of the code above fp may, at this point, be + * less than .1, this is ok because the code below can + * handle the leading zeros this generates, so no attempt + * is made to correct that here. + */ + + { + unsigned int czero, clead, cdigits; + char exponent[10]; + + /* Allow up to two leading zeros - this will not lengthen + * the number compared to using E-n. + */ + if (exp_b10 < 0 && exp_b10 > -3) /* PLUS 3 TOTAL 4 */ + { + czero = 0U-exp_b10; /* PLUS 2 digits: TOTAL 3 */ + exp_b10 = 0; /* Dot added below before first output. */ + } + else + czero = 0; /* No zeros to add */ + + /* Generate the digit list, stripping trailing zeros and + * inserting a '.' before a digit if the exponent is 0. + */ + clead = czero; /* Count of leading zeros */ + cdigits = 0; /* Count of digits in list. */ + + do + { + double d; + + fp *= 10; + /* Use modf here, not floor and subtract, so that + * the separation is done in one step. At the end + * of the loop don't break the number into parts so + * that the final digit is rounded. + */ + if (cdigits+czero+1 < precision+clead) + fp = modf(fp, &d); + + else + { + d = floor(fp + .5); + + if (d > 9) + { + /* Rounding up to 10, handle that here. */ + if (czero > 0) + { + --czero; d = 1; + if (cdigits == 0) --clead; + } + else + { + while (cdigits > 0 && d > 9) + { + int ch = *--ascii; + + if (exp_b10 != (-1)) + ++exp_b10; + + else if (ch == 46) + { + ch = *--ascii; ++size; + /* Advance exp_b10 to '1', so that the + * decimal point happens after the + * previous digit. + */ + exp_b10 = 1; + } + + --cdigits; + d = ch - 47; /* I.e. 1+(ch-48) */ + } + + /* Did we reach the beginning? If so adjust the + * exponent but take into account the leading + * decimal point. + */ + if (d > 9) /* cdigits == 0 */ + { + if (exp_b10 == (-1)) + { + /* Leading decimal point (plus zeros?), if + * we lose the decimal point here it must + * be reentered below. + */ + int ch = *--ascii; + + if (ch == 46) + { + ++size; exp_b10 = 1; + } + + /* Else lost a leading zero, so 'exp_b10' is + * still ok at (-1) + */ + } + else + ++exp_b10; + + /* In all cases we output a '1' */ + d = 1; + } + } + } + fp = 0; /* Guarantees termination below. */ + } + + if (d == 0) + { + ++czero; + if (cdigits == 0) ++clead; + } + else + { + /* Included embedded zeros in the digit count. */ + cdigits += czero - clead; + clead = 0; + + while (czero > 0) + { + /* exp_b10 == (-1) means we just output the decimal + * place - after the DP don't adjust 'exp_b10' any + * more! + */ + if (exp_b10 != (-1)) + { + if (exp_b10 == 0) + { + *ascii++ = 46; --size; + } + /* PLUS 1: TOTAL 4 */ + --exp_b10; + } + *ascii++ = 48; --czero; + } + + if (exp_b10 != (-1)) + { + if (exp_b10 == 0) + { + *ascii++ = 46; --size; /* counted above */ + } + + --exp_b10; + } + *ascii++ = (char)(48 + (int)d); ++cdigits; + } + } + while (cdigits+czero < precision+clead && fp > DBL_MIN); + + /* The total output count (max) is now 4+precision */ + + /* Check for an exponent, if we don't need one we are + * done and just need to terminate the string. At this + * point, exp_b10==(-1) is effectively a flag: it got + * to '-1' because of the decrement, after outputting + * the decimal point above. (The exponent required is + * *not* -1.) + */ + if (exp_b10 >= (-1) && exp_b10 <= 2) + { + /* The following only happens if we didn't output the + * leading zeros above for negative exponent, so this + * doesn't add to the digit requirement. Note that the + * two zeros here can only be output if the two leading + * zeros were *not* output, so this doesn't increase + * the output count. + */ + while (exp_b10-- > 0) *ascii++ = 48; + + *ascii = 0; + + /* Total buffer requirement (including the '\0') is + * 5+precision - see check at the start. + */ + return; + } + + /* Here if an exponent is required, adjust size for + * the digits we output but did not count. The total + * digit output here so far is at most 1+precision - no + * decimal point and no leading or trailing zeros have + * been output. + */ + size -= cdigits; + + *ascii++ = 69; --size; /* 'E': PLUS 1 TOTAL 2+precision */ + + /* The following use of an unsigned temporary avoids ambiguities in + * the signed arithmetic on exp_b10 and permits GCC at least to do + * better optimization. + */ + { + unsigned int uexp_b10; + + if (exp_b10 < 0) + { + *ascii++ = 45; --size; /* '-': PLUS 1 TOTAL 3+precision */ + uexp_b10 = 0U-exp_b10; + } + + else + uexp_b10 = 0U+exp_b10; + + cdigits = 0; + + while (uexp_b10 > 0) + { + exponent[cdigits++] = (char)(48 + uexp_b10 % 10); + uexp_b10 /= 10; + } + } + + /* Need another size check here for the exponent digits, so + * this need not be considered above. + */ + if (size > cdigits) + { + while (cdigits > 0) *ascii++ = exponent[--cdigits]; + + *ascii = 0; + + return; + } + } + } + else if (!(fp >= DBL_MIN)) + { + *ascii++ = 48; /* '0' */ + *ascii = 0; + return; + } + else + { + *ascii++ = 105; /* 'i' */ + *ascii++ = 110; /* 'n' */ + *ascii++ = 102; /* 'f' */ + *ascii = 0; + return; + } + } + + /* Here on buffer too small. */ + png_error(png_ptr, "ASCII conversion buffer too small"); +} +#if GCC_STRICT_OVERFLOW +#pragma GCC diagnostic pop +#endif /* GCC_STRICT_OVERFLOW */ + +# endif /* FLOATING_POINT */ + +# ifdef PNG_FIXED_POINT_SUPPORTED +/* Function to format a fixed point value in ASCII. + */ +void /* PRIVATE */ +png_ascii_from_fixed(png_const_structrp png_ptr, png_charp ascii, + size_t size, png_fixed_point fp) +{ + /* Require space for 10 decimal digits, a decimal point, a minus sign and a + * trailing \0, 13 characters: + */ + if (size > 12) + { + png_uint_32 num; + + /* Avoid overflow here on the minimum integer. */ + if (fp < 0) + { + *ascii++ = 45; num = (png_uint_32)(-fp); + } + else + num = (png_uint_32)fp; + + if (num <= 0x80000000) /* else overflowed */ + { + unsigned int ndigits = 0, first = 16 /* flag value */; + char digits[10]; + + while (num) + { + /* Split the low digit off num: */ + unsigned int tmp = num/10; + num -= tmp*10; + digits[ndigits++] = (char)(48 + num); + /* Record the first non-zero digit, note that this is a number + * starting at 1, it's not actually the array index. + */ + if (first == 16 && num > 0) + first = ndigits; + num = tmp; + } + + if (ndigits > 0) + { + while (ndigits > 5) *ascii++ = digits[--ndigits]; + /* The remaining digits are fractional digits, ndigits is '5' or + * smaller at this point. It is certainly not zero. Check for a + * non-zero fractional digit: + */ + if (first <= 5) + { + unsigned int i; + *ascii++ = 46; /* decimal point */ + /* ndigits may be <5 for small numbers, output leading zeros + * then ndigits digits to first: + */ + i = 5; + while (ndigits < i) + { + *ascii++ = 48; --i; + } + while (ndigits >= first) *ascii++ = digits[--ndigits]; + /* Don't output the trailing zeros! */ + } + } + else + *ascii++ = 48; + + /* And null terminate the string: */ + *ascii = 0; + return; + } + } + + /* Here on buffer too small. */ + png_error(png_ptr, "ASCII conversion buffer too small"); +} +# endif /* FIXED_POINT */ +#endif /* SCAL */ + +#if defined(PNG_FLOATING_POINT_SUPPORTED) && \ + !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \ + (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \ + defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \ + (defined(PNG_sCAL_SUPPORTED) && \ + defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)) +png_fixed_point +png_fixed(png_const_structrp png_ptr, double fp, png_const_charp text) +{ + double r = floor(100000 * fp + .5); + + if (r > 2147483647. || r < -2147483648.) + png_fixed_error(png_ptr, text); + +# ifndef PNG_ERROR_TEXT_SUPPORTED + PNG_UNUSED(text) +# endif + + return (png_fixed_point)r; +} +#endif + +#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_COLORSPACE_SUPPORTED) ||\ + defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED) +/* muldiv functions */ +/* This API takes signed arguments and rounds the result to the nearest + * integer (or, for a fixed point number - the standard argument - to + * the nearest .00001). Overflow and divide by zero are signalled in + * the result, a boolean - true on success, false on overflow. + */ +#if GCC_STRICT_OVERFLOW /* from above */ +/* It is not obvious which comparison below gets optimized in such a way that + * signed overflow would change the result; looking through the code does not + * reveal any tests which have the form GCC complains about, so presumably the + * optimizer is moving an add or subtract into the 'if' somewhere. + */ +#pragma GCC diagnostic push +#pragma GCC diagnostic warning "-Wstrict-overflow=2" +#endif /* GCC_STRICT_OVERFLOW */ +int +png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times, + png_int_32 divisor) +{ + /* Return a * times / divisor, rounded. */ + if (divisor != 0) + { + if (a == 0 || times == 0) + { + *res = 0; + return 1; + } + else + { +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + double r = a; + r *= times; + r /= divisor; + r = floor(r+.5); + + /* A png_fixed_point is a 32-bit integer. */ + if (r <= 2147483647. && r >= -2147483648.) + { + *res = (png_fixed_point)r; + return 1; + } +#else + int negative = 0; + png_uint_32 A, T, D; + png_uint_32 s16, s32, s00; + + if (a < 0) + negative = 1, A = -a; + else + A = a; + + if (times < 0) + negative = !negative, T = -times; + else + T = times; + + if (divisor < 0) + negative = !negative, D = -divisor; + else + D = divisor; + + /* Following can't overflow because the arguments only + * have 31 bits each, however the result may be 32 bits. + */ + s16 = (A >> 16) * (T & 0xffff) + + (A & 0xffff) * (T >> 16); + /* Can't overflow because the a*times bit is only 30 + * bits at most. + */ + s32 = (A >> 16) * (T >> 16) + (s16 >> 16); + s00 = (A & 0xffff) * (T & 0xffff); + + s16 = (s16 & 0xffff) << 16; + s00 += s16; + + if (s00 < s16) + ++s32; /* carry */ + + if (s32 < D) /* else overflow */ + { + /* s32.s00 is now the 64-bit product, do a standard + * division, we know that s32 < D, so the maximum + * required shift is 31. + */ + int bitshift = 32; + png_fixed_point result = 0; /* NOTE: signed */ + + while (--bitshift >= 0) + { + png_uint_32 d32, d00; + + if (bitshift > 0) + d32 = D >> (32-bitshift), d00 = D << bitshift; + + else + d32 = 0, d00 = D; + + if (s32 > d32) + { + if (s00 < d00) --s32; /* carry */ + s32 -= d32, s00 -= d00, result += 1<<bitshift; + } + + else + if (s32 == d32 && s00 >= d00) + s32 = 0, s00 -= d00, result += 1<<bitshift; + } + + /* Handle the rounding. */ + if (s00 >= (D >> 1)) + ++result; + + if (negative != 0) + result = -result; + + /* Check for overflow. */ + if ((negative != 0 && result <= 0) || + (negative == 0 && result >= 0)) + { + *res = result; + return 1; + } + } +#endif + } + } + + return 0; +} +#if GCC_STRICT_OVERFLOW +#pragma GCC diagnostic pop +#endif /* GCC_STRICT_OVERFLOW */ +#endif /* READ_GAMMA || INCH_CONVERSIONS */ + +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED) +/* The following is for when the caller doesn't much care about the + * result. + */ +png_fixed_point +png_muldiv_warn(png_const_structrp png_ptr, png_fixed_point a, png_int_32 times, + png_int_32 divisor) +{ + png_fixed_point result; + + if (png_muldiv(&result, a, times, divisor) != 0) + return result; + + png_warning(png_ptr, "fixed point overflow ignored"); + return 0; +} +#endif + +#ifdef PNG_GAMMA_SUPPORTED /* more fixed point functions for gamma */ +/* Calculate a reciprocal, return 0 on div-by-zero or overflow. */ +png_fixed_point +png_reciprocal(png_fixed_point a) +{ +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + double r = floor(1E10/a+.5); + + if (r <= 2147483647. && r >= -2147483648.) + return (png_fixed_point)r; +#else + png_fixed_point res; + + if (png_muldiv(&res, 100000, 100000, a) != 0) + return res; +#endif + + return 0; /* error/overflow */ +} + +/* This is the shared test on whether a gamma value is 'significant' - whether + * it is worth doing gamma correction. + */ +int /* PRIVATE */ +png_gamma_significant(png_fixed_point gamma_val) +{ + return gamma_val < PNG_FP_1 - PNG_GAMMA_THRESHOLD_FIXED || + gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED; +} +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED +#ifdef PNG_16BIT_SUPPORTED +/* A local convenience routine. */ +static png_fixed_point +png_product2(png_fixed_point a, png_fixed_point b) +{ + /* The required result is 1/a * 1/b; the following preserves accuracy. */ +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + double r = a * 1E-5; + r *= b; + r = floor(r+.5); + + if (r <= 2147483647. && r >= -2147483648.) + return (png_fixed_point)r; +#else + png_fixed_point res; + + if (png_muldiv(&res, a, b, 100000) != 0) + return res; +#endif + + return 0; /* overflow */ +} +#endif /* 16BIT */ + +/* The inverse of the above. */ +png_fixed_point +png_reciprocal2(png_fixed_point a, png_fixed_point b) +{ + /* The required result is 1/a * 1/b; the following preserves accuracy. */ +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + if (a != 0 && b != 0) + { + double r = 1E15/a; + r /= b; + r = floor(r+.5); + + if (r <= 2147483647. && r >= -2147483648.) + return (png_fixed_point)r; + } +#else + /* This may overflow because the range of png_fixed_point isn't symmetric, + * but this API is only used for the product of file and screen gamma so it + * doesn't matter that the smallest number it can produce is 1/21474, not + * 1/100000 + */ + png_fixed_point res = png_product2(a, b); + + if (res != 0) + return png_reciprocal(res); +#endif + + return 0; /* overflow */ +} +#endif /* READ_GAMMA */ + +#ifdef PNG_READ_GAMMA_SUPPORTED /* gamma table code */ +#ifndef PNG_FLOATING_ARITHMETIC_SUPPORTED +/* Fixed point gamma. + * + * The code to calculate the tables used below can be found in the shell script + * contrib/tools/intgamma.sh + * + * To calculate gamma this code implements fast log() and exp() calls using only + * fixed point arithmetic. This code has sufficient precision for either 8-bit + * or 16-bit sample values. + * + * The tables used here were calculated using simple 'bc' programs, but C double + * precision floating point arithmetic would work fine. + * + * 8-bit log table + * This is a table of -log(value/255)/log(2) for 'value' in the range 128 to + * 255, so it's the base 2 logarithm of a normalized 8-bit floating point + * mantissa. The numbers are 32-bit fractions. + */ +static const png_uint_32 +png_8bit_l2[128] = +{ + 4270715492U, 4222494797U, 4174646467U, 4127164793U, 4080044201U, 4033279239U, + 3986864580U, 3940795015U, 3895065449U, 3849670902U, 3804606499U, 3759867474U, + 3715449162U, 3671346997U, 3627556511U, 3584073329U, 3540893168U, 3498011834U, + 3455425220U, 3413129301U, 3371120137U, 3329393864U, 3287946700U, 3246774933U, + 3205874930U, 3165243125U, 3124876025U, 3084770202U, 3044922296U, 3005329011U, + 2965987113U, 2926893432U, 2888044853U, 2849438323U, 2811070844U, 2772939474U, + 2735041326U, 2697373562U, 2659933400U, 2622718104U, 2585724991U, 2548951424U, + 2512394810U, 2476052606U, 2439922311U, 2404001468U, 2368287663U, 2332778523U, + 2297471715U, 2262364947U, 2227455964U, 2192742551U, 2158222529U, 2123893754U, + 2089754119U, 2055801552U, 2022034013U, 1988449497U, 1955046031U, 1921821672U, + 1888774511U, 1855902668U, 1823204291U, 1790677560U, 1758320682U, 1726131893U, + 1694109454U, 1662251657U, 1630556815U, 1599023271U, 1567649391U, 1536433567U, + 1505374214U, 1474469770U, 1443718700U, 1413119487U, 1382670639U, 1352370686U, + 1322218179U, 1292211689U, 1262349810U, 1232631153U, 1203054352U, 1173618059U, + 1144320946U, 1115161701U, 1086139034U, 1057251672U, 1028498358U, 999877854U, + 971388940U, 943030410U, 914801076U, 886699767U, 858725327U, 830876614U, + 803152505U, 775551890U, 748073672U, 720716771U, 693480120U, 666362667U, + 639363374U, 612481215U, 585715177U, 559064263U, 532527486U, 506103872U, + 479792461U, 453592303U, 427502463U, 401522014U, 375650043U, 349885648U, + 324227938U, 298676034U, 273229066U, 247886176U, 222646516U, 197509248U, + 172473545U, 147538590U, 122703574U, 97967701U, 73330182U, 48790236U, + 24347096U, 0U + +#if 0 + /* The following are the values for 16-bit tables - these work fine for the + * 8-bit conversions but produce very slightly larger errors in the 16-bit + * log (about 1.2 as opposed to 0.7 absolute error in the final value). To + * use these all the shifts below must be adjusted appropriately. + */ + 65166, 64430, 63700, 62976, 62257, 61543, 60835, 60132, 59434, 58741, 58054, + 57371, 56693, 56020, 55352, 54689, 54030, 53375, 52726, 52080, 51439, 50803, + 50170, 49542, 48918, 48298, 47682, 47070, 46462, 45858, 45257, 44661, 44068, + 43479, 42894, 42312, 41733, 41159, 40587, 40020, 39455, 38894, 38336, 37782, + 37230, 36682, 36137, 35595, 35057, 34521, 33988, 33459, 32932, 32408, 31887, + 31369, 30854, 30341, 29832, 29325, 28820, 28319, 27820, 27324, 26830, 26339, + 25850, 25364, 24880, 24399, 23920, 23444, 22970, 22499, 22029, 21562, 21098, + 20636, 20175, 19718, 19262, 18808, 18357, 17908, 17461, 17016, 16573, 16132, + 15694, 15257, 14822, 14390, 13959, 13530, 13103, 12678, 12255, 11834, 11415, + 10997, 10582, 10168, 9756, 9346, 8937, 8531, 8126, 7723, 7321, 6921, 6523, + 6127, 5732, 5339, 4947, 4557, 4169, 3782, 3397, 3014, 2632, 2251, 1872, 1495, + 1119, 744, 372 +#endif +}; + +static png_int_32 +png_log8bit(unsigned int x) +{ + unsigned int lg2 = 0; + /* Each time 'x' is multiplied by 2, 1 must be subtracted off the final log, + * because the log is actually negate that means adding 1. The final + * returned value thus has the range 0 (for 255 input) to 7.994 (for 1 + * input), return -1 for the overflow (log 0) case, - so the result is + * always at most 19 bits. + */ + if ((x &= 0xff) == 0) + return -1; + + if ((x & 0xf0) == 0) + lg2 = 4, x <<= 4; + + if ((x & 0xc0) == 0) + lg2 += 2, x <<= 2; + + if ((x & 0x80) == 0) + lg2 += 1, x <<= 1; + + /* result is at most 19 bits, so this cast is safe: */ + return (png_int_32)((lg2 << 16) + ((png_8bit_l2[x-128]+32768)>>16)); +} + +/* The above gives exact (to 16 binary places) log2 values for 8-bit images, + * for 16-bit images we use the most significant 8 bits of the 16-bit value to + * get an approximation then multiply the approximation by a correction factor + * determined by the remaining up to 8 bits. This requires an additional step + * in the 16-bit case. + * + * We want log2(value/65535), we have log2(v'/255), where: + * + * value = v' * 256 + v'' + * = v' * f + * + * So f is value/v', which is equal to (256+v''/v') since v' is in the range 128 + * to 255 and v'' is in the range 0 to 255 f will be in the range 256 to less + * than 258. The final factor also needs to correct for the fact that our 8-bit + * value is scaled by 255, whereas the 16-bit values must be scaled by 65535. + * + * This gives a final formula using a calculated value 'x' which is value/v' and + * scaling by 65536 to match the above table: + * + * log2(x/257) * 65536 + * + * Since these numbers are so close to '1' we can use simple linear + * interpolation between the two end values 256/257 (result -368.61) and 258/257 + * (result 367.179). The values used below are scaled by a further 64 to give + * 16-bit precision in the interpolation: + * + * Start (256): -23591 + * Zero (257): 0 + * End (258): 23499 + */ +#ifdef PNG_16BIT_SUPPORTED +static png_int_32 +png_log16bit(png_uint_32 x) +{ + unsigned int lg2 = 0; + + /* As above, but now the input has 16 bits. */ + if ((x &= 0xffff) == 0) + return -1; + + if ((x & 0xff00) == 0) + lg2 = 8, x <<= 8; + + if ((x & 0xf000) == 0) + lg2 += 4, x <<= 4; + + if ((x & 0xc000) == 0) + lg2 += 2, x <<= 2; + + if ((x & 0x8000) == 0) + lg2 += 1, x <<= 1; + + /* Calculate the base logarithm from the top 8 bits as a 28-bit fractional + * value. + */ + lg2 <<= 28; + lg2 += (png_8bit_l2[(x>>8)-128]+8) >> 4; + + /* Now we need to interpolate the factor, this requires a division by the top + * 8 bits. Do this with maximum precision. + */ + x = ((x << 16) + (x >> 9)) / (x >> 8); + + /* Since we divided by the top 8 bits of 'x' there will be a '1' at 1<<24, + * the value at 1<<16 (ignoring this) will be 0 or 1; this gives us exactly + * 16 bits to interpolate to get the low bits of the result. Round the + * answer. Note that the end point values are scaled by 64 to retain overall + * precision and that 'lg2' is current scaled by an extra 12 bits, so adjust + * the overall scaling by 6-12. Round at every step. + */ + x -= 1U << 24; + + if (x <= 65536U) /* <= '257' */ + lg2 += ((23591U * (65536U-x)) + (1U << (16+6-12-1))) >> (16+6-12); + + else + lg2 -= ((23499U * (x-65536U)) + (1U << (16+6-12-1))) >> (16+6-12); + + /* Safe, because the result can't have more than 20 bits: */ + return (png_int_32)((lg2 + 2048) >> 12); +} +#endif /* 16BIT */ + +/* The 'exp()' case must invert the above, taking a 20-bit fixed point + * logarithmic value and returning a 16 or 8-bit number as appropriate. In + * each case only the low 16 bits are relevant - the fraction - since the + * integer bits (the top 4) simply determine a shift. + * + * The worst case is the 16-bit distinction between 65535 and 65534. This + * requires perhaps spurious accuracy in the decoding of the logarithm to + * distinguish log2(65535/65534.5) - 10^-5 or 17 bits. There is little chance + * of getting this accuracy in practice. + * + * To deal with this the following exp() function works out the exponent of the + * fractional part of the logarithm by using an accurate 32-bit value from the + * top four fractional bits then multiplying in the remaining bits. + */ +static const png_uint_32 +png_32bit_exp[16] = +{ + /* NOTE: the first entry is deliberately set to the maximum 32-bit value. */ + 4294967295U, 4112874773U, 3938502376U, 3771522796U, 3611622603U, 3458501653U, + 3311872529U, 3171459999U, 3037000500U, 2908241642U, 2784941738U, 2666869345U, + 2553802834U, 2445529972U, 2341847524U, 2242560872U +}; + +/* Adjustment table; provided to explain the numbers in the code below. */ +#if 0 +for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"} + 11 44937.64284865548751208448 + 10 45180.98734845585101160448 + 9 45303.31936980687359311872 + 8 45364.65110595323018870784 + 7 45395.35850361789624614912 + 6 45410.72259715102037508096 + 5 45418.40724413220722311168 + 4 45422.25021786898173001728 + 3 45424.17186732298419044352 + 2 45425.13273269940811464704 + 1 45425.61317555035558641664 + 0 45425.85339951654943850496 +#endif + +static png_uint_32 +png_exp(png_fixed_point x) +{ + if (x > 0 && x <= 0xfffff) /* Else overflow or zero (underflow) */ + { + /* Obtain a 4-bit approximation */ + png_uint_32 e = png_32bit_exp[(x >> 12) & 0x0f]; + + /* Incorporate the low 12 bits - these decrease the returned value by + * multiplying by a number less than 1 if the bit is set. The multiplier + * is determined by the above table and the shift. Notice that the values + * converge on 45426 and this is used to allow linear interpolation of the + * low bits. + */ + if (x & 0x800) + e -= (((e >> 16) * 44938U) + 16U) >> 5; + + if (x & 0x400) + e -= (((e >> 16) * 45181U) + 32U) >> 6; + + if (x & 0x200) + e -= (((e >> 16) * 45303U) + 64U) >> 7; + + if (x & 0x100) + e -= (((e >> 16) * 45365U) + 128U) >> 8; + + if (x & 0x080) + e -= (((e >> 16) * 45395U) + 256U) >> 9; + + if (x & 0x040) + e -= (((e >> 16) * 45410U) + 512U) >> 10; + + /* And handle the low 6 bits in a single block. */ + e -= (((e >> 16) * 355U * (x & 0x3fU)) + 256U) >> 9; + + /* Handle the upper bits of x. */ + e >>= x >> 16; + return e; + } + + /* Check for overflow */ + if (x <= 0) + return png_32bit_exp[0]; + + /* Else underflow */ + return 0; +} + +static png_byte +png_exp8bit(png_fixed_point lg2) +{ + /* Get a 32-bit value: */ + png_uint_32 x = png_exp(lg2); + + /* Convert the 32-bit value to 0..255 by multiplying by 256-1. Note that the + * second, rounding, step can't overflow because of the first, subtraction, + * step. + */ + x -= x >> 8; + return (png_byte)(((x + 0x7fffffU) >> 24) & 0xff); +} + +#ifdef PNG_16BIT_SUPPORTED +static png_uint_16 +png_exp16bit(png_fixed_point lg2) +{ + /* Get a 32-bit value: */ + png_uint_32 x = png_exp(lg2); + + /* Convert the 32-bit value to 0..65535 by multiplying by 65536-1: */ + x -= x >> 16; + return (png_uint_16)((x + 32767U) >> 16); +} +#endif /* 16BIT */ +#endif /* FLOATING_ARITHMETIC */ + +png_byte +png_gamma_8bit_correct(unsigned int value, png_fixed_point gamma_val) +{ + if (value > 0 && value < 255) + { +# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + /* 'value' is unsigned, ANSI-C90 requires the compiler to correctly + * convert this to a floating point value. This includes values that + * would overflow if 'value' were to be converted to 'int'. + * + * Apparently GCC, however, does an intermediate conversion to (int) + * on some (ARM) but not all (x86) platforms, possibly because of + * hardware FP limitations. (E.g. if the hardware conversion always + * assumes the integer register contains a signed value.) This results + * in ANSI-C undefined behavior for large values. + * + * Other implementations on the same machine might actually be ANSI-C90 + * conformant and therefore compile spurious extra code for the large + * values. + * + * We can be reasonably sure that an unsigned to float conversion + * won't be faster than an int to float one. Therefore this code + * assumes responsibility for the undefined behavior, which it knows + * can't happen because of the check above. + * + * Note the argument to this routine is an (unsigned int) because, on + * 16-bit platforms, it is assigned a value which might be out of + * range for an (int); that would result in undefined behavior in the + * caller if the *argument* ('value') were to be declared (int). + */ + double r = floor(255*pow((int)/*SAFE*/value/255.,gamma_val*.00001)+.5); + return (png_byte)r; +# else + png_int_32 lg2 = png_log8bit(value); + png_fixed_point res; + + if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0) + return png_exp8bit(res); + + /* Overflow. */ + value = 0; +# endif + } + + return (png_byte)(value & 0xff); +} + +#ifdef PNG_16BIT_SUPPORTED +png_uint_16 +png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val) +{ + if (value > 0 && value < 65535) + { +# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + /* The same (unsigned int)->(double) constraints apply here as above, + * however in this case the (unsigned int) to (int) conversion can + * overflow on an ANSI-C90 compliant system so the cast needs to ensure + * that this is not possible. + */ + double r = floor(65535*pow((png_int_32)value/65535., + gamma_val*.00001)+.5); + return (png_uint_16)r; +# else + png_int_32 lg2 = png_log16bit(value); + png_fixed_point res; + + if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0) + return png_exp16bit(res); + + /* Overflow. */ + value = 0; +# endif + } + + return (png_uint_16)value; +} +#endif /* 16BIT */ + +/* This does the right thing based on the bit_depth field of the + * png_struct, interpreting values as 8-bit or 16-bit. While the result + * is nominally a 16-bit value if bit depth is 8 then the result is + * 8-bit (as are the arguments.) + */ +png_uint_16 /* PRIVATE */ +png_gamma_correct(png_structrp png_ptr, unsigned int value, + png_fixed_point gamma_val) +{ + if (png_ptr->bit_depth == 8) + return png_gamma_8bit_correct(value, gamma_val); + +#ifdef PNG_16BIT_SUPPORTED + else + return png_gamma_16bit_correct(value, gamma_val); +#else + /* should not reach this */ + return 0; +#endif /* 16BIT */ +} + +#ifdef PNG_16BIT_SUPPORTED +/* Internal function to build a single 16-bit table - the table consists of + * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount + * to shift the input values right (or 16-number_of_signifiant_bits). + * + * The caller is responsible for ensuring that the table gets cleaned up on + * png_error (i.e. if one of the mallocs below fails) - i.e. the *table argument + * should be somewhere that will be cleaned. + */ +static void +png_build_16bit_table(png_structrp png_ptr, png_uint_16pp *ptable, + unsigned int shift, png_fixed_point gamma_val) +{ + /* Various values derived from 'shift': */ + unsigned int num = 1U << (8U - shift); +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + /* CSE the division and work round wacky GCC warnings (see the comments + * in png_gamma_8bit_correct for where these come from.) + */ + double fmax = 1.0 / (((png_int_32)1 << (16U - shift)) - 1); +#endif + unsigned int max = (1U << (16U - shift)) - 1U; + unsigned int max_by_2 = 1U << (15U - shift); + unsigned int i; + + png_uint_16pp table = *ptable = + (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p))); + + for (i = 0; i < num; i++) + { + png_uint_16p sub_table = table[i] = + (png_uint_16p)png_malloc(png_ptr, 256 * (sizeof (png_uint_16))); + + /* The 'threshold' test is repeated here because it can arise for one of + * the 16-bit tables even if the others don't hit it. + */ + if (png_gamma_significant(gamma_val) != 0) + { + /* The old code would overflow at the end and this would cause the + * 'pow' function to return a result >1, resulting in an + * arithmetic error. This code follows the spec exactly; ig is + * the recovered input sample, it always has 8-16 bits. + * + * We want input * 65535/max, rounded, the arithmetic fits in 32 + * bits (unsigned) so long as max <= 32767. + */ + unsigned int j; + for (j = 0; j < 256; j++) + { + png_uint_32 ig = (j << (8-shift)) + i; +# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + /* Inline the 'max' scaling operation: */ + /* See png_gamma_8bit_correct for why the cast to (int) is + * required here. + */ + double d = floor(65535.*pow(ig*fmax, gamma_val*.00001)+.5); + sub_table[j] = (png_uint_16)d; +# else + if (shift != 0) + ig = (ig * 65535U + max_by_2)/max; + + sub_table[j] = png_gamma_16bit_correct(ig, gamma_val); +# endif + } + } + else + { + /* We must still build a table, but do it the fast way. */ + unsigned int j; + + for (j = 0; j < 256; j++) + { + png_uint_32 ig = (j << (8-shift)) + i; + + if (shift != 0) + ig = (ig * 65535U + max_by_2)/max; + + sub_table[j] = (png_uint_16)ig; + } + } + } +} + +/* NOTE: this function expects the *inverse* of the overall gamma transformation + * required. + */ +static void +png_build_16to8_table(png_structrp png_ptr, png_uint_16pp *ptable, + unsigned int shift, png_fixed_point gamma_val) +{ + unsigned int num = 1U << (8U - shift); + unsigned int max = (1U << (16U - shift))-1U; + unsigned int i; + png_uint_32 last; + + png_uint_16pp table = *ptable = + (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p))); + + /* 'num' is the number of tables and also the number of low bits of low + * bits of the input 16-bit value used to select a table. Each table is + * itself indexed by the high 8 bits of the value. + */ + for (i = 0; i < num; i++) + table[i] = (png_uint_16p)png_malloc(png_ptr, + 256 * (sizeof (png_uint_16))); + + /* 'gamma_val' is set to the reciprocal of the value calculated above, so + * pow(out,g) is an *input* value. 'last' is the last input value set. + * + * In the loop 'i' is used to find output values. Since the output is + * 8-bit there are only 256 possible values. The tables are set up to + * select the closest possible output value for each input by finding + * the input value at the boundary between each pair of output values + * and filling the table up to that boundary with the lower output + * value. + * + * The boundary values are 0.5,1.5..253.5,254.5. Since these are 9-bit + * values the code below uses a 16-bit value in i; the values start at + * 128.5 (for 0.5) and step by 257, for a total of 254 values (the last + * entries are filled with 255). Start i at 128 and fill all 'last' + * table entries <= 'max' + */ + last = 0; + for (i = 0; i < 255; ++i) /* 8-bit output value */ + { + /* Find the corresponding maximum input value */ + png_uint_16 out = (png_uint_16)(i * 257U); /* 16-bit output value */ + + /* Find the boundary value in 16 bits: */ + png_uint_32 bound = png_gamma_16bit_correct(out+128U, gamma_val); + + /* Adjust (round) to (16-shift) bits: */ + bound = (bound * max + 32768U)/65535U + 1U; + + while (last < bound) + { + table[last & (0xffU >> shift)][last >> (8U - shift)] = out; + last++; + } + } + + /* And fill in the final entries. */ + while (last < (num << 8)) + { + table[last & (0xff >> shift)][last >> (8U - shift)] = 65535U; + last++; + } +} +#endif /* 16BIT */ + +/* Build a single 8-bit table: same as the 16-bit case but much simpler (and + * typically much faster). Note that libpng currently does no sBIT processing + * (apparently contrary to the spec) so a 256-entry table is always generated. + */ +static void +png_build_8bit_table(png_structrp png_ptr, png_bytepp ptable, + png_fixed_point gamma_val) +{ + unsigned int i; + png_bytep table = *ptable = (png_bytep)png_malloc(png_ptr, 256); + + if (png_gamma_significant(gamma_val) != 0) + for (i=0; i<256; i++) + table[i] = png_gamma_8bit_correct(i, gamma_val); + + else + for (i=0; i<256; ++i) + table[i] = (png_byte)(i & 0xff); +} + +/* Used from png_read_destroy and below to release the memory used by the gamma + * tables. + */ +void /* PRIVATE */ +png_destroy_gamma_table(png_structrp png_ptr) +{ + png_free(png_ptr, png_ptr->gamma_table); + png_ptr->gamma_table = NULL; + +#ifdef PNG_16BIT_SUPPORTED + if (png_ptr->gamma_16_table != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_table[i]); + } + png_free(png_ptr, png_ptr->gamma_16_table); + png_ptr->gamma_16_table = NULL; + } +#endif /* 16BIT */ + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) + png_free(png_ptr, png_ptr->gamma_from_1); + png_ptr->gamma_from_1 = NULL; + png_free(png_ptr, png_ptr->gamma_to_1); + png_ptr->gamma_to_1 = NULL; + +#ifdef PNG_16BIT_SUPPORTED + if (png_ptr->gamma_16_from_1 != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_from_1[i]); + } + png_free(png_ptr, png_ptr->gamma_16_from_1); + png_ptr->gamma_16_from_1 = NULL; + } + if (png_ptr->gamma_16_to_1 != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_to_1[i]); + } + png_free(png_ptr, png_ptr->gamma_16_to_1); + png_ptr->gamma_16_to_1 = NULL; + } +#endif /* 16BIT */ +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ +} + +/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit + * tables, we don't make a full table if we are reducing to 8-bit in + * the future. Note also how the gamma_16 tables are segmented so that + * we don't need to allocate > 64K chunks for a full 16-bit table. + */ +void /* PRIVATE */ +png_build_gamma_table(png_structrp png_ptr, int bit_depth) +{ + png_debug(1, "in png_build_gamma_table"); + + /* Remove any existing table; this copes with multiple calls to + * png_read_update_info. The warning is because building the gamma tables + * multiple times is a performance hit - it's harmless but the ability to + * call png_read_update_info() multiple times is new in 1.5.6 so it seems + * sensible to warn if the app introduces such a hit. + */ + if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL) + { + png_warning(png_ptr, "gamma table being rebuilt"); + png_destroy_gamma_table(png_ptr); + } + + if (bit_depth <= 8) + { + png_build_8bit_table(png_ptr, &png_ptr->gamma_table, + png_ptr->screen_gamma > 0 ? + png_reciprocal2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma) : PNG_FP_1); + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) + if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0) + { + png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1, + png_reciprocal(png_ptr->colorspace.gamma)); + + png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1, + png_ptr->screen_gamma > 0 ? + png_reciprocal(png_ptr->screen_gamma) : + png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */); + } +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ + } +#ifdef PNG_16BIT_SUPPORTED + else + { + png_byte shift, sig_bit; + + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + sig_bit = png_ptr->sig_bit.red; + + if (png_ptr->sig_bit.green > sig_bit) + sig_bit = png_ptr->sig_bit.green; + + if (png_ptr->sig_bit.blue > sig_bit) + sig_bit = png_ptr->sig_bit.blue; + } + else + sig_bit = png_ptr->sig_bit.gray; + + /* 16-bit gamma code uses this equation: + * + * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8] + * + * Where 'iv' is the input color value and 'ov' is the output value - + * pow(iv, gamma). + * + * Thus the gamma table consists of up to 256 256-entry tables. The table + * is selected by the (8-gamma_shift) most significant of the low 8 bits + * of the color value then indexed by the upper 8 bits: + * + * table[low bits][high 8 bits] + * + * So the table 'n' corresponds to all those 'iv' of: + * + * <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1> + * + */ + if (sig_bit > 0 && sig_bit < 16U) + /* shift == insignificant bits */ + shift = (png_byte)((16U - sig_bit) & 0xff); + + else + shift = 0; /* keep all 16 bits */ + + if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0) + { + /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively + * the significant bits in the *input* when the output will + * eventually be 8 bits. By default it is 11. + */ + if (shift < (16U - PNG_MAX_GAMMA_8)) + shift = (16U - PNG_MAX_GAMMA_8); + } + + if (shift > 8U) + shift = 8U; /* Guarantees at least one table! */ + + png_ptr->gamma_shift = shift; + + /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now + * PNG_COMPOSE). This effectively smashed the background calculation for + * 16-bit output because the 8-bit table assumes the result will be + * reduced to 8 bits. + */ + if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0) + png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift, + png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma) : PNG_FP_1); + + else + png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift, + png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma) : PNG_FP_1); + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) + if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0) + { + png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift, + png_reciprocal(png_ptr->colorspace.gamma)); + + /* Notice that the '16 from 1' table should be full precision, however + * the lookup on this table still uses gamma_shift, so it can't be. + * TODO: fix this. + */ + png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift, + png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : + png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */); + } +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ + } +#endif /* 16BIT */ +} +#endif /* READ_GAMMA */ + +/* HARDWARE OR SOFTWARE OPTION SUPPORT */ +#ifdef PNG_SET_OPTION_SUPPORTED +int PNGAPI +png_set_option(png_structrp png_ptr, int option, int onoff) +{ + if (png_ptr != NULL && option >= 0 && option < PNG_OPTION_NEXT && + (option & 1) == 0) + { + png_uint_32 mask = 3U << option; + png_uint_32 setting = (2U + (onoff != 0)) << option; + png_uint_32 current = png_ptr->options; + + png_ptr->options = (png_uint_32)((current & ~mask) | setting); + + return (int)(current & mask) >> option; + } + + return PNG_OPTION_INVALID; +} +#endif + +/* sRGB support */ +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) +/* sRGB conversion tables; these are machine generated with the code in + * contrib/tools/makesRGB.c. The actual sRGB transfer curve defined in the + * specification (see the article at https://en.wikipedia.org/wiki/SRGB) + * is used, not the gamma=1/2.2 approximation use elsewhere in libpng. + * The sRGB to linear table is exact (to the nearest 16-bit linear fraction). + * The inverse (linear to sRGB) table has accuracies as follows: + * + * For all possible (255*65535+1) input values: + * + * error: -0.515566 - 0.625971, 79441 (0.475369%) of readings inexact + * + * For the input values corresponding to the 65536 16-bit values: + * + * error: -0.513727 - 0.607759, 308 (0.469978%) of readings inexact + * + * In all cases the inexact readings are only off by one. + */ + +#ifdef PNG_SIMPLIFIED_READ_SUPPORTED +/* The convert-to-sRGB table is only currently required for read. */ +const png_uint_16 png_sRGB_table[256] = +{ + 0,20,40,60,80,99,119,139, + 159,179,199,219,241,264,288,313, + 340,367,396,427,458,491,526,562, + 599,637,677,718,761,805,851,898, + 947,997,1048,1101,1156,1212,1270,1330, + 1391,1453,1517,1583,1651,1720,1790,1863, + 1937,2013,2090,2170,2250,2333,2418,2504, + 2592,2681,2773,2866,2961,3058,3157,3258, + 3360,3464,3570,3678,3788,3900,4014,4129, + 4247,4366,4488,4611,4736,4864,4993,5124, + 5257,5392,5530,5669,5810,5953,6099,6246, + 6395,6547,6700,6856,7014,7174,7335,7500, + 7666,7834,8004,8177,8352,8528,8708,8889, + 9072,9258,9445,9635,9828,10022,10219,10417, + 10619,10822,11028,11235,11446,11658,11873,12090, + 12309,12530,12754,12980,13209,13440,13673,13909, + 14146,14387,14629,14874,15122,15371,15623,15878, + 16135,16394,16656,16920,17187,17456,17727,18001, + 18277,18556,18837,19121,19407,19696,19987,20281, + 20577,20876,21177,21481,21787,22096,22407,22721, + 23038,23357,23678,24002,24329,24658,24990,25325, + 25662,26001,26344,26688,27036,27386,27739,28094, + 28452,28813,29176,29542,29911,30282,30656,31033, + 31412,31794,32179,32567,32957,33350,33745,34143, + 34544,34948,35355,35764,36176,36591,37008,37429, + 37852,38278,38706,39138,39572,40009,40449,40891, + 41337,41785,42236,42690,43147,43606,44069,44534, + 45002,45473,45947,46423,46903,47385,47871,48359, + 48850,49344,49841,50341,50844,51349,51858,52369, + 52884,53401,53921,54445,54971,55500,56032,56567, + 57105,57646,58190,58737,59287,59840,60396,60955, + 61517,62082,62650,63221,63795,64372,64952,65535 +}; +#endif /* SIMPLIFIED_READ */ + +/* The base/delta tables are required for both read and write (but currently + * only the simplified versions.) + */ +const png_uint_16 png_sRGB_base[512] = +{ + 128,1782,3383,4644,5675,6564,7357,8074, + 8732,9346,9921,10463,10977,11466,11935,12384, + 12816,13233,13634,14024,14402,14769,15125,15473, + 15812,16142,16466,16781,17090,17393,17690,17981, + 18266,18546,18822,19093,19359,19621,19879,20133, + 20383,20630,20873,21113,21349,21583,21813,22041, + 22265,22487,22707,22923,23138,23350,23559,23767, + 23972,24175,24376,24575,24772,24967,25160,25352, + 25542,25730,25916,26101,26284,26465,26645,26823, + 27000,27176,27350,27523,27695,27865,28034,28201, + 28368,28533,28697,28860,29021,29182,29341,29500, + 29657,29813,29969,30123,30276,30429,30580,30730, + 30880,31028,31176,31323,31469,31614,31758,31902, + 32045,32186,32327,32468,32607,32746,32884,33021, + 33158,33294,33429,33564,33697,33831,33963,34095, + 34226,34357,34486,34616,34744,34873,35000,35127, + 35253,35379,35504,35629,35753,35876,35999,36122, + 36244,36365,36486,36606,36726,36845,36964,37083, + 37201,37318,37435,37551,37668,37783,37898,38013, + 38127,38241,38354,38467,38580,38692,38803,38915, + 39026,39136,39246,39356,39465,39574,39682,39790, + 39898,40005,40112,40219,40325,40431,40537,40642, + 40747,40851,40955,41059,41163,41266,41369,41471, + 41573,41675,41777,41878,41979,42079,42179,42279, + 42379,42478,42577,42676,42775,42873,42971,43068, + 43165,43262,43359,43456,43552,43648,43743,43839, + 43934,44028,44123,44217,44311,44405,44499,44592, + 44685,44778,44870,44962,45054,45146,45238,45329, + 45420,45511,45601,45692,45782,45872,45961,46051, + 46140,46229,46318,46406,46494,46583,46670,46758, + 46846,46933,47020,47107,47193,47280,47366,47452, + 47538,47623,47709,47794,47879,47964,48048,48133, + 48217,48301,48385,48468,48552,48635,48718,48801, + 48884,48966,49048,49131,49213,49294,49376,49458, + 49539,49620,49701,49782,49862,49943,50023,50103, + 50183,50263,50342,50422,50501,50580,50659,50738, + 50816,50895,50973,51051,51129,51207,51285,51362, + 51439,51517,51594,51671,51747,51824,51900,51977, + 52053,52129,52205,52280,52356,52432,52507,52582, + 52657,52732,52807,52881,52956,53030,53104,53178, + 53252,53326,53400,53473,53546,53620,53693,53766, + 53839,53911,53984,54056,54129,54201,54273,54345, + 54417,54489,54560,54632,54703,54774,54845,54916, + 54987,55058,55129,55199,55269,55340,55410,55480, + 55550,55620,55689,55759,55828,55898,55967,56036, + 56105,56174,56243,56311,56380,56448,56517,56585, + 56653,56721,56789,56857,56924,56992,57059,57127, + 57194,57261,57328,57395,57462,57529,57595,57662, + 57728,57795,57861,57927,57993,58059,58125,58191, + 58256,58322,58387,58453,58518,58583,58648,58713, + 58778,58843,58908,58972,59037,59101,59165,59230, + 59294,59358,59422,59486,59549,59613,59677,59740, + 59804,59867,59930,59993,60056,60119,60182,60245, + 60308,60370,60433,60495,60558,60620,60682,60744, + 60806,60868,60930,60992,61054,61115,61177,61238, + 61300,61361,61422,61483,61544,61605,61666,61727, + 61788,61848,61909,61969,62030,62090,62150,62211, + 62271,62331,62391,62450,62510,62570,62630,62689, + 62749,62808,62867,62927,62986,63045,63104,63163, + 63222,63281,63340,63398,63457,63515,63574,63632, + 63691,63749,63807,63865,63923,63981,64039,64097, + 64155,64212,64270,64328,64385,64443,64500,64557, + 64614,64672,64729,64786,64843,64900,64956,65013, + 65070,65126,65183,65239,65296,65352,65409,65465 +}; + +const png_byte png_sRGB_delta[512] = +{ + 207,201,158,129,113,100,90,82,77,72,68,64,61,59,56,54, + 52,50,49,47,46,45,43,42,41,40,39,39,38,37,36,36, + 35,34,34,33,33,32,32,31,31,30,30,30,29,29,28,28, + 28,27,27,27,27,26,26,26,25,25,25,25,24,24,24,24, + 23,23,23,23,23,22,22,22,22,22,22,21,21,21,21,21, + 21,20,20,20,20,20,20,20,20,19,19,19,19,19,19,19, + 19,18,18,18,18,18,18,18,18,18,18,17,17,17,17,17, + 17,17,17,17,17,17,16,16,16,16,16,16,16,16,16,16, + 16,16,16,16,15,15,15,15,15,15,15,15,15,15,15,15, + 15,15,15,15,14,14,14,14,14,14,14,14,14,14,14,14, + 14,14,14,14,14,14,14,13,13,13,13,13,13,13,13,13, + 13,13,13,13,13,13,13,13,13,13,13,13,13,13,12,12, + 12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12, + 12,12,12,12,12,12,12,12,12,12,12,12,11,11,11,11, + 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11, + 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11, + 11,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10, + 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10, + 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10, + 10,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, + 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, + 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, + 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, + 9,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7 +}; +#endif /* SIMPLIFIED READ/WRITE sRGB support */ + +/* SIMPLIFIED READ/WRITE SUPPORT */ +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) +static int +png_image_free_function(png_voidp argument) +{ + png_imagep image = png_voidcast(png_imagep, argument); + png_controlp cp = image->opaque; + png_control c; + + /* Double check that we have a png_ptr - it should be impossible to get here + * without one. + */ + if (cp->png_ptr == NULL) + return 0; + + /* First free any data held in the control structure. */ +# ifdef PNG_STDIO_SUPPORTED + if (cp->owned_file != 0) + { + FILE *fp = png_voidcast(FILE*, cp->png_ptr->io_ptr); + cp->owned_file = 0; + + /* Ignore errors here. */ + if (fp != NULL) + { + cp->png_ptr->io_ptr = NULL; + (void)fclose(fp); + } + } +# endif + + /* Copy the control structure so that the original, allocated, version can be + * safely freed. Notice that a png_error here stops the remainder of the + * cleanup, but this is probably fine because that would indicate bad memory + * problems anyway. + */ + c = *cp; + image->opaque = &c; + png_free(c.png_ptr, cp); + + /* Then the structures, calling the correct API. */ + if (c.for_write != 0) + { +# ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED + png_destroy_write_struct(&c.png_ptr, &c.info_ptr); +# else + png_error(c.png_ptr, "simplified write not supported"); +# endif + } + else + { +# ifdef PNG_SIMPLIFIED_READ_SUPPORTED + png_destroy_read_struct(&c.png_ptr, &c.info_ptr, NULL); +# else + png_error(c.png_ptr, "simplified read not supported"); +# endif + } + + /* Success. */ + return 1; +} + +void PNGAPI +png_image_free(png_imagep image) +{ + /* Safely call the real function, but only if doing so is safe at this point + * (if not inside an error handling context). Otherwise assume + * png_safe_execute will call this API after the return. + */ + if (image != NULL && image->opaque != NULL && + image->opaque->error_buf == NULL) + { + png_image_free_function(image); + image->opaque = NULL; + } +} + +int /* PRIVATE */ +png_image_error(png_imagep image, png_const_charp error_message) +{ + /* Utility to log an error. */ + png_safecat(image->message, (sizeof image->message), 0, error_message); + image->warning_or_error |= PNG_IMAGE_ERROR; + png_image_free(image); + return 0; +} + +#endif /* SIMPLIFIED READ/WRITE */ +#endif /* READ || WRITE */ diff --git a/media/libpng/png.h b/media/libpng/png.h new file mode 100644 index 0000000000..6ea3698c20 --- /dev/null +++ b/media/libpng/png.h @@ -0,0 +1,3343 @@ + +/* png.h - header file for PNG reference library + * + * libpng version 1.6.37 - April 14, 2019 + * + * Copyright (c) 2018-2019 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. (See LICENSE, below.) + * + * Authors and maintainers: + * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat + * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger + * libpng versions 0.97, January 1998, through 1.6.35, July 2018: + * Glenn Randers-Pehrson + * libpng versions 1.6.36, December 2018, through 1.6.37, April 2019: + * Cosmin Truta + * See also "Contributing Authors", below. + */ + +/* + * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE + * ========================================= + * + * PNG Reference Library License version 2 + * --------------------------------------- + * + * * Copyright (c) 1995-2019 The PNG Reference Library Authors. + * * Copyright (c) 2018-2019 Cosmin Truta. + * * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson. + * * Copyright (c) 1996-1997 Andreas Dilger. + * * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * The software is supplied "as is", without warranty of any kind, + * express or implied, including, without limitation, the warranties + * of merchantability, fitness for a particular purpose, title, and + * non-infringement. In no event shall the Copyright owners, or + * anyone distributing the software, be liable for any damages or + * other liability, whether in contract, tort or otherwise, arising + * from, out of, or in connection with the software, or the use or + * other dealings in the software, even if advised of the possibility + * of such damage. + * + * Permission is hereby granted to use, copy, modify, and distribute + * this software, or portions hereof, for any purpose, without fee, + * subject to the following restrictions: + * + * 1. The origin of this software must not be misrepresented; you + * must not claim that you wrote the original software. If you + * use this software in a product, an acknowledgment in the product + * documentation would be appreciated, but is not required. + * + * 2. Altered source versions must be plainly marked as such, and must + * not be misrepresented as being the original software. + * + * 3. This Copyright notice may not be removed or altered from any + * source or altered source distribution. + * + * + * PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35) + * ----------------------------------------------------------------------- + * + * libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are + * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are + * derived from libpng-1.0.6, and are distributed according to the same + * disclaimer and license as libpng-1.0.6 with the following individuals + * added to the list of Contributing Authors: + * + * Simon-Pierre Cadieux + * Eric S. Raymond + * Mans Rullgard + * Cosmin Truta + * Gilles Vollant + * James Yu + * Mandar Sahastrabuddhe + * Google Inc. + * Vadim Barkov + * + * and with the following additions to the disclaimer: + * + * There is no warranty against interference with your enjoyment of + * the library or against infringement. There is no warranty that our + * efforts or the library will fulfill any of your particular purposes + * or needs. This library is provided with all faults, and the entire + * risk of satisfactory quality, performance, accuracy, and effort is + * with the user. + * + * Some files in the "contrib" directory and some configure-generated + * files that are distributed with libpng have other copyright owners, and + * are released under other open source licenses. + * + * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are + * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from + * libpng-0.96, and are distributed according to the same disclaimer and + * license as libpng-0.96, with the following individuals added to the + * list of Contributing Authors: + * + * Tom Lane + * Glenn Randers-Pehrson + * Willem van Schaik + * + * libpng versions 0.89, June 1996, through 0.96, May 1997, are + * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, + * and are distributed according to the same disclaimer and license as + * libpng-0.88, with the following individuals added to the list of + * Contributing Authors: + * + * John Bowler + * Kevin Bracey + * Sam Bushell + * Magnus Holmgren + * Greg Roelofs + * Tom Tanner + * + * Some files in the "scripts" directory have other copyright owners, + * but are released under this license. + * + * libpng versions 0.5, May 1995, through 0.88, January 1996, are + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * For the purposes of this copyright and license, "Contributing Authors" + * is defined as the following set of individuals: + * + * Andreas Dilger + * Dave Martindale + * Guy Eric Schalnat + * Paul Schmidt + * Tim Wegner + * + * The PNG Reference Library is supplied "AS IS". The Contributing + * Authors and Group 42, Inc. disclaim all warranties, expressed or + * implied, including, without limitation, the warranties of + * merchantability and of fitness for any purpose. The Contributing + * Authors and Group 42, Inc. assume no liability for direct, indirect, + * incidental, special, exemplary, or consequential damages, which may + * result from the use of the PNG Reference Library, even if advised of + * the possibility of such damage. + * + * Permission is hereby granted to use, copy, modify, and distribute this + * source code, or portions hereof, for any purpose, without fee, subject + * to the following restrictions: + * + * 1. The origin of this source code must not be misrepresented. + * + * 2. Altered versions must be plainly marked as such and must not + * be misrepresented as being the original source. + * + * 3. This Copyright notice may not be removed or altered from any + * source or altered source distribution. + * + * The Contributing Authors and Group 42, Inc. specifically permit, + * without fee, and encourage the use of this source code as a component + * to supporting the PNG file format in commercial products. If you use + * this source code in a product, acknowledgment is not required but would + * be appreciated. + * + * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. + * + * TRADEMARK + * ========= + * + * The name "libpng" has not been registered by the Copyright owners + * as a trademark in any jurisdiction. However, because libpng has + * been distributed and maintained world-wide, continually since 1995, + * the Copyright owners claim "common-law trademark protection" in any + * jurisdiction where common-law trademark is recognized. + */ + +/* + * A "png_get_copyright" function is available, for convenient use in "about" + * boxes and the like: + * + * printf("%s", png_get_copyright(NULL)); + * + * Also, the PNG logo (in PNG format, of course) is supplied in the + * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). + */ + +/* + * The contributing authors would like to thank all those who helped + * with testing, bug fixes, and patience. This wouldn't have been + * possible without all of you. + * + * Thanks to Frank J. T. Wojcik for helping with the documentation. + */ + +/* Note about libpng version numbers: + * + * Due to various miscommunications, unforeseen code incompatibilities + * and occasional factors outside the authors' control, version numbering + * on the library has not always been consistent and straightforward. + * The following table summarizes matters since version 0.89c, which was + * the first widely used release: + * + * source png.h png.h shared-lib + * version string int version + * ------- ------ ----- ---------- + * 0.89c "1.0 beta 3" 0.89 89 1.0.89 + * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] + * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] + * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] + * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] + * 0.97c 0.97 97 2.0.97 + * 0.98 0.98 98 2.0.98 + * 0.99 0.99 98 2.0.99 + * 0.99a-m 0.99 99 2.0.99 + * 1.00 1.00 100 2.1.0 [100 should be 10000] + * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] + * 1.0.1 png.h string is 10001 2.1.0 + * 1.0.1a-e identical to the 10002 from here on, the shared library + * 1.0.2 source version) 10002 is 2.V where V is the source code + * 1.0.2a-b 10003 version, except as noted. + * 1.0.3 10003 + * 1.0.3a-d 10004 + * 1.0.4 10004 + * 1.0.4a-f 10005 + * 1.0.5 (+ 2 patches) 10005 + * 1.0.5a-d 10006 + * 1.0.5e-r 10100 (not source compatible) + * 1.0.5s-v 10006 (not binary compatible) + * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) + * 1.0.6d-f 10007 (still binary incompatible) + * 1.0.6g 10007 + * 1.0.6h 10007 10.6h (testing xy.z so-numbering) + * 1.0.6i 10007 10.6i + * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) + * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) + * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) + * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) + * 1.0.7 1 10007 (still compatible) + * ... + * 1.0.69 10 10069 10.so.0.69[.0] + * ... + * 1.2.59 13 10259 12.so.0.59[.0] + * ... + * 1.4.20 14 10420 14.so.0.20[.0] + * ... + * 1.5.30 15 10530 15.so.15.30[.0] + * ... + * 1.6.37 16 10637 16.so.16.37[.0] + * + * Henceforth the source version will match the shared-library major and + * minor numbers; the shared-library major version number will be used for + * changes in backward compatibility, as it is intended. + * The PNG_LIBPNG_VER macro, which is not used within libpng but is + * available for applications, is an unsigned integer of the form XYYZZ + * corresponding to the source version X.Y.Z (leading zeros in Y and Z). + * Beta versions were given the previous public release number plus a + * letter, until version 1.0.6j; from then on they were given the upcoming + * public release number plus "betaNN" or "rcNN". + * + * Binary incompatibility exists only when applications make direct access + * to the info_ptr or png_ptr members through png.h, and the compiled + * application is loaded with a different version of the library. + * + * DLLNUM will change each time there are forward or backward changes + * in binary compatibility (e.g., when a new feature is added). + * + * See libpng.txt or libpng.3 for more information. The PNG specification + * is available as a W3C Recommendation and as an ISO/IEC Standard; see + * <https://www.w3.org/TR/2003/REC-PNG-20031110/> + */ + +#ifndef PNG_H +#define PNG_H + +/* This is not the place to learn how to use libpng. The file libpng-manual.txt + * describes how to use libpng, and the file example.c summarizes it + * with some code on which to build. This file is useful for looking + * at the actual function definitions and structure components. If that + * file has been stripped from your copy of libpng, you can find it at + * <http://www.libpng.org/pub/png/libpng-manual.txt> + * + * If you just need to read a PNG file and don't want to read the documentation + * skip to the end of this file and read the section entitled 'simplified API'. + */ + +/* Version information for png.h - this should match the version in png.c */ +#define PNG_LIBPNG_VER_STRING "1.6.37" +#define PNG_HEADER_VERSION_STRING " libpng version 1.6.37 - April 14, 2019\n" + +#define PNG_LIBPNG_VER_SONUM 16 +#define PNG_LIBPNG_VER_DLLNUM 16 + +/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ +#define PNG_LIBPNG_VER_MAJOR 1 +#define PNG_LIBPNG_VER_MINOR 6 +#define PNG_LIBPNG_VER_RELEASE 37 + +/* This should be zero for a public release, or non-zero for a + * development version. [Deprecated] + */ +#define PNG_LIBPNG_VER_BUILD 0 + +/* Release Status */ +#define PNG_LIBPNG_BUILD_ALPHA 1 +#define PNG_LIBPNG_BUILD_BETA 2 +#define PNG_LIBPNG_BUILD_RC 3 +#define PNG_LIBPNG_BUILD_STABLE 4 +#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 + +/* Release-Specific Flags */ +#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with + PNG_LIBPNG_BUILD_STABLE only */ +#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with + PNG_LIBPNG_BUILD_SPECIAL */ +#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with + PNG_LIBPNG_BUILD_PRIVATE */ + +#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE + +/* Careful here. At one time, Guy wanted to use 082, but that + * would be octal. We must not include leading zeros. + * Versions 0.7 through 1.0.0 were in the range 0 to 100 here + * (only version 1.0.0 was mis-numbered 100 instead of 10000). + * From version 1.0.1 it is: + * XXYYZZ, where XX=major, YY=minor, ZZ=release + */ +#define PNG_LIBPNG_VER 10637 /* 1.6.37 */ + +/* Library configuration: these options cannot be changed after + * the library has been built. + */ +#ifndef PNGLCONF_H +/* If pnglibconf.h is missing, you can + * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h + */ +# include "pnglibconf.h" +#endif + +#define PNG_APNG_SUPPORTED +#define PNG_READ_APNG_SUPPORTED +#define PNG_WRITE_APNG_SUPPORTED + +#ifndef PNG_VERSION_INFO_ONLY +/* Machine specific configuration. */ +# include "pngconf.h" +#endif + +/* + * Added at libpng-1.2.8 + * + * Ref MSDN: Private as priority over Special + * VS_FF_PRIVATEBUILD File *was not* built using standard release + * procedures. If this value is given, the StringFileInfo block must + * contain a PrivateBuild string. + * + * VS_FF_SPECIALBUILD File *was* built by the original company using + * standard release procedures but is a variation of the standard + * file of the same version number. If this value is given, the + * StringFileInfo block must contain a SpecialBuild string. + */ + +#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ +# define PNG_LIBPNG_BUILD_TYPE \ + (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) +#else +# ifdef PNG_LIBPNG_SPECIALBUILD +# define PNG_LIBPNG_BUILD_TYPE \ + (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) +# else +# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) +# endif +#endif + +#ifndef PNG_VERSION_INFO_ONLY + +/* Inhibit C++ name-mangling for libpng functions but not for system calls. */ +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* Version information for C files, stored in png.c. This had better match + * the version above. + */ +#define png_libpng_ver png_get_header_ver(NULL) + +/* This file is arranged in several sections: + * + * 1. [omitted] + * 2. Any configuration options that can be specified by for the application + * code when it is built. (Build time configuration is in pnglibconf.h) + * 3. Type definitions (base types are defined in pngconf.h), structure + * definitions. + * 4. Exported library functions. + * 5. Simplified API. + * 6. Implementation options. + * + * The library source code has additional files (principally pngpriv.h) that + * allow configuration of the library. + */ + +/* Section 1: [omitted] */ + +/* Section 2: run time configuration + * See pnglibconf.h for build time configuration + * + * Run time configuration allows the application to choose between + * implementations of certain arithmetic APIs. The default is set + * at build time and recorded in pnglibconf.h, but it is safe to + * override these (and only these) settings. Note that this won't + * change what the library does, only application code, and the + * settings can (and probably should) be made on a per-file basis + * by setting the #defines before including png.h + * + * Use macros to read integers from PNG data or use the exported + * functions? + * PNG_USE_READ_MACROS: use the macros (see below) Note that + * the macros evaluate their argument multiple times. + * PNG_NO_USE_READ_MACROS: call the relevant library function. + * + * Use the alternative algorithm for compositing alpha samples that + * does not use division? + * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' + * algorithm. + * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. + * + * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is + * false? + * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error + * APIs to png_warning. + * Otherwise the calls are mapped to png_error. + */ + +/* Section 3: type definitions, including structures and compile time + * constants. + * See pngconf.h for base types that vary by machine/system + */ + +#ifdef PNG_APNG_SUPPORTED +/* dispose_op flags from inside fcTL */ +#define PNG_DISPOSE_OP_NONE 0x00 +#define PNG_DISPOSE_OP_BACKGROUND 0x01 +#define PNG_DISPOSE_OP_PREVIOUS 0x02 + +/* blend_op flags from inside fcTL */ +#define PNG_BLEND_OP_SOURCE 0x00 +#define PNG_BLEND_OP_OVER 0x01 +#endif /* APNG */ + +/* This triggers a compiler error in png.c, if png.c and png.h + * do not agree upon the version number. + */ +typedef char* png_libpng_version_1_6_37; + +/* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. + * + * png_struct is the cache of information used while reading or writing a single + * PNG file. One of these is always required, although the simplified API + * (below) hides the creation and destruction of it. + */ +typedef struct png_struct_def png_struct; +typedef const png_struct * png_const_structp; +typedef png_struct * png_structp; +typedef png_struct * * png_structpp; + +/* png_info contains information read from or to be written to a PNG file. One + * or more of these must exist while reading or creating a PNG file. The + * information is not used by libpng during read but is used to control what + * gets written when a PNG file is created. "png_get_" function calls read + * information during read and "png_set_" functions calls write information + * when creating a PNG. + * been moved into a separate header file that is not accessible to + * applications. Read libpng-manual.txt or libpng.3 for more info. + */ +typedef struct png_info_def png_info; +typedef png_info * png_infop; +typedef const png_info * png_const_infop; +typedef png_info * * png_infopp; + +/* Types with names ending 'p' are pointer types. The corresponding types with + * names ending 'rp' are identical pointer types except that the pointer is + * marked 'restrict', which means that it is the only pointer to the object + * passed to the function. Applications should not use the 'restrict' types; + * it is always valid to pass 'p' to a pointer with a function argument of the + * corresponding 'rp' type. Different compilers have different rules with + * regard to type matching in the presence of 'restrict'. For backward + * compatibility libpng callbacks never have 'restrict' in their parameters and, + * consequentially, writing portable application code is extremely difficult if + * an attempt is made to use 'restrict'. + */ +typedef png_struct * PNG_RESTRICT png_structrp; +typedef const png_struct * PNG_RESTRICT png_const_structrp; +typedef png_info * PNG_RESTRICT png_inforp; +typedef const png_info * PNG_RESTRICT png_const_inforp; + +/* Three color definitions. The order of the red, green, and blue, (and the + * exact size) is not important, although the size of the fields need to + * be png_byte or png_uint_16 (as defined below). + */ +typedef struct png_color_struct +{ + png_byte red; + png_byte green; + png_byte blue; +} png_color; +typedef png_color * png_colorp; +typedef const png_color * png_const_colorp; +typedef png_color * * png_colorpp; + +typedef struct png_color_16_struct +{ + png_byte index; /* used for palette files */ + png_uint_16 red; /* for use in red green blue files */ + png_uint_16 green; + png_uint_16 blue; + png_uint_16 gray; /* for use in grayscale files */ +} png_color_16; +typedef png_color_16 * png_color_16p; +typedef const png_color_16 * png_const_color_16p; +typedef png_color_16 * * png_color_16pp; + +typedef struct png_color_8_struct +{ + png_byte red; /* for use in red green blue files */ + png_byte green; + png_byte blue; + png_byte gray; /* for use in grayscale files */ + png_byte alpha; /* for alpha channel files */ +} png_color_8; +typedef png_color_8 * png_color_8p; +typedef const png_color_8 * png_const_color_8p; +typedef png_color_8 * * png_color_8pp; + +/* + * The following two structures are used for the in-core representation + * of sPLT chunks. + */ +typedef struct png_sPLT_entry_struct +{ + png_uint_16 red; + png_uint_16 green; + png_uint_16 blue; + png_uint_16 alpha; + png_uint_16 frequency; +} png_sPLT_entry; +typedef png_sPLT_entry * png_sPLT_entryp; +typedef const png_sPLT_entry * png_const_sPLT_entryp; +typedef png_sPLT_entry * * png_sPLT_entrypp; + +/* When the depth of the sPLT palette is 8 bits, the color and alpha samples + * occupy the LSB of their respective members, and the MSB of each member + * is zero-filled. The frequency member always occupies the full 16 bits. + */ + +typedef struct png_sPLT_struct +{ + png_charp name; /* palette name */ + png_byte depth; /* depth of palette samples */ + png_sPLT_entryp entries; /* palette entries */ + png_int_32 nentries; /* number of palette entries */ +} png_sPLT_t; +typedef png_sPLT_t * png_sPLT_tp; +typedef const png_sPLT_t * png_const_sPLT_tp; +typedef png_sPLT_t * * png_sPLT_tpp; + +#ifdef PNG_TEXT_SUPPORTED +/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, + * and whether that contents is compressed or not. The "key" field + * points to a regular zero-terminated C string. The "text" fields can be a + * regular C string, an empty string, or a NULL pointer. + * However, the structure returned by png_get_text() will always contain + * the "text" field as a regular zero-terminated C string (possibly + * empty), never a NULL pointer, so it can be safely used in printf() and + * other string-handling functions. Note that the "itxt_length", "lang", and + * "lang_key" members of the structure only exist when the library is built + * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by + * default without iTXt support. Also note that when iTXt *is* supported, + * the "lang" and "lang_key" fields contain NULL pointers when the + * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or + * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the + * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" + * which is always 0 or 1, or its "compression method" which is always 0. + */ +typedef struct png_text_struct +{ + int compression; /* compression value: + -1: tEXt, none + 0: zTXt, deflate + 1: iTXt, none + 2: iTXt, deflate */ + png_charp key; /* keyword, 1-79 character description of "text" */ + png_charp text; /* comment, may be an empty string (ie "") + or a NULL pointer */ + size_t text_length; /* length of the text string */ + size_t itxt_length; /* length of the itxt string */ + png_charp lang; /* language code, 0-79 characters + or a NULL pointer */ + png_charp lang_key; /* keyword translated UTF-8 string, 0 or more + chars or a NULL pointer */ +} png_text; +typedef png_text * png_textp; +typedef const png_text * png_const_textp; +typedef png_text * * png_textpp; +#endif + +/* Supported compression types for text in PNG files (tEXt, and zTXt). + * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ +#define PNG_TEXT_COMPRESSION_NONE_WR -3 +#define PNG_TEXT_COMPRESSION_zTXt_WR -2 +#define PNG_TEXT_COMPRESSION_NONE -1 +#define PNG_TEXT_COMPRESSION_zTXt 0 +#define PNG_ITXT_COMPRESSION_NONE 1 +#define PNG_ITXT_COMPRESSION_zTXt 2 +#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ + +/* png_time is a way to hold the time in an machine independent way. + * Two conversions are provided, both from time_t and struct tm. There + * is no portable way to convert to either of these structures, as far + * as I know. If you know of a portable way, send it to me. As a side + * note - PNG has always been Year 2000 compliant! + */ +typedef struct png_time_struct +{ + png_uint_16 year; /* full year, as in, 1995 */ + png_byte month; /* month of year, 1 - 12 */ + png_byte day; /* day of month, 1 - 31 */ + png_byte hour; /* hour of day, 0 - 23 */ + png_byte minute; /* minute of hour, 0 - 59 */ + png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ +} png_time; +typedef png_time * png_timep; +typedef const png_time * png_const_timep; +typedef png_time * * png_timepp; + +#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ + defined(PNG_USER_CHUNKS_SUPPORTED) +/* png_unknown_chunk is a structure to hold queued chunks for which there is + * no specific support. The idea is that we can use this to queue + * up private chunks for output even though the library doesn't actually + * know about their semantics. + * + * The data in the structure is set by libpng on read and used on write. + */ +typedef struct png_unknown_chunk_t +{ + png_byte name[5]; /* Textual chunk name with '\0' terminator */ + png_byte *data; /* Data, should not be modified on read! */ + size_t size; + + /* On write 'location' must be set using the flag values listed below. + * Notice that on read it is set by libpng however the values stored have + * more bits set than are listed below. Always treat the value as a + * bitmask. On write set only one bit - setting multiple bits may cause the + * chunk to be written in multiple places. + */ + png_byte location; /* mode of operation at read time */ +} +png_unknown_chunk; + +typedef png_unknown_chunk * png_unknown_chunkp; +typedef const png_unknown_chunk * png_const_unknown_chunkp; +typedef png_unknown_chunk * * png_unknown_chunkpp; +#endif + +/* Flag values for the unknown chunk location byte. */ +#define PNG_HAVE_IHDR 0x01 +#define PNG_HAVE_PLTE 0x02 +#define PNG_AFTER_IDAT 0x08 + +/* Maximum positive integer used in PNG is (2^31)-1 */ +#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) +#define PNG_UINT_32_MAX ((png_uint_32)(-1)) +#define PNG_SIZE_MAX ((size_t)(-1)) + +/* These are constants for fixed point values encoded in the + * PNG specification manner (x100000) + */ +#define PNG_FP_1 100000 +#define PNG_FP_HALF 50000 +#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) +#define PNG_FP_MIN (-PNG_FP_MAX) + +/* These describe the color_type field in png_info. */ +/* color type masks */ +#define PNG_COLOR_MASK_PALETTE 1 +#define PNG_COLOR_MASK_COLOR 2 +#define PNG_COLOR_MASK_ALPHA 4 + +/* color types. Note that not all combinations are legal */ +#define PNG_COLOR_TYPE_GRAY 0 +#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) +#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) +#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) +#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) +/* aliases */ +#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA +#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA + +/* This is for compression type. PNG 1.0-1.2 only define the single type. */ +#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ +#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE + +/* This is for filter type. PNG 1.0-1.2 only define the single type. */ +#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ +#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ +#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE + +/* These are for the interlacing type. These values should NOT be changed. */ +#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ +#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ +#define PNG_INTERLACE_LAST 2 /* Not a valid value */ + +/* These are for the oFFs chunk. These values should NOT be changed. */ +#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ +#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ +#define PNG_OFFSET_LAST 2 /* Not a valid value */ + +/* These are for the pCAL chunk. These values should NOT be changed. */ +#define PNG_EQUATION_LINEAR 0 /* Linear transformation */ +#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ +#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ +#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ +#define PNG_EQUATION_LAST 4 /* Not a valid value */ + +/* These are for the sCAL chunk. These values should NOT be changed. */ +#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ +#define PNG_SCALE_METER 1 /* meters per pixel */ +#define PNG_SCALE_RADIAN 2 /* radians per pixel */ +#define PNG_SCALE_LAST 3 /* Not a valid value */ + +/* These are for the pHYs chunk. These values should NOT be changed. */ +#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ +#define PNG_RESOLUTION_METER 1 /* pixels/meter */ +#define PNG_RESOLUTION_LAST 2 /* Not a valid value */ + +/* These are for the sRGB chunk. These values should NOT be changed. */ +#define PNG_sRGB_INTENT_PERCEPTUAL 0 +#define PNG_sRGB_INTENT_RELATIVE 1 +#define PNG_sRGB_INTENT_SATURATION 2 +#define PNG_sRGB_INTENT_ABSOLUTE 3 +#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ + +/* This is for text chunks */ +#define PNG_KEYWORD_MAX_LENGTH 79 + +/* Maximum number of entries in PLTE/sPLT/tRNS arrays */ +#define PNG_MAX_PALETTE_LENGTH 256 + +/* These determine if an ancillary chunk's data has been successfully read + * from the PNG header, or if the application has filled in the corresponding + * data in the info_struct to be written into the output file. The values + * of the PNG_INFO_<chunk> defines should NOT be changed. + */ +#define PNG_INFO_gAMA 0x0001U +#define PNG_INFO_sBIT 0x0002U +#define PNG_INFO_cHRM 0x0004U +#define PNG_INFO_PLTE 0x0008U +#define PNG_INFO_tRNS 0x0010U +#define PNG_INFO_bKGD 0x0020U +#define PNG_INFO_hIST 0x0040U +#define PNG_INFO_pHYs 0x0080U +#define PNG_INFO_oFFs 0x0100U +#define PNG_INFO_tIME 0x0200U +#define PNG_INFO_pCAL 0x0400U +#define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */ +#define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */ +#define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */ +#define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */ +#define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */ +#define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */ +#ifdef PNG_APNG_SUPPORTED +#define PNG_INFO_acTL 0x20000U +#define PNG_INFO_fcTL 0x40000U +#endif + +/* This is used for the transformation routines, as some of them + * change these values for the row. It also should enable using + * the routines for other purposes. + */ +typedef struct png_row_info_struct +{ + png_uint_32 width; /* width of row */ + size_t rowbytes; /* number of bytes in row */ + png_byte color_type; /* color type of row */ + png_byte bit_depth; /* bit depth of row */ + png_byte channels; /* number of channels (1, 2, 3, or 4) */ + png_byte pixel_depth; /* bits per pixel (depth * channels) */ +} png_row_info; + +typedef png_row_info * png_row_infop; +typedef png_row_info * * png_row_infopp; + +/* These are the function types for the I/O functions and for the functions + * that allow the user to override the default I/O functions with his or her + * own. The png_error_ptr type should match that of user-supplied warning + * and error functions, while the png_rw_ptr type should match that of the + * user read/write data functions. Note that the 'write' function must not + * modify the buffer it is passed. The 'read' function, on the other hand, is + * expected to return the read data in the buffer. + */ +typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); +typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, size_t)); +typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); +typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, + int)); +typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, + int)); + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); +typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); +#ifdef PNG_APNG_SUPPORTED +typedef PNG_CALLBACK(void, *png_progressive_frame_ptr, (png_structp, + png_uint_32)); +#endif + +/* The following callback receives png_uint_32 row_number, int pass for the + * png_bytep data of the row. When transforming an interlaced image the + * row number is the row number within the sub-image of the interlace pass, so + * the value will increase to the height of the sub-image (not the full image) + * then reset to 0 for the next pass. + * + * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to + * find the output pixel (x,y) given an interlaced sub-image pixel + * (row,col,pass). (See below for these macros.) + */ +typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, + png_uint_32, int)); +#endif + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, + png_bytep)); +#endif + +#ifdef PNG_USER_CHUNKS_SUPPORTED +typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, + png_unknown_chunkp)); +#endif +#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED +/* not used anywhere */ +/* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ +#endif + +#ifdef PNG_SETJMP_SUPPORTED +/* This must match the function definition in <setjmp.h>, and the application + * must include this before png.h to obtain the definition of jmp_buf. The + * function is required to be PNG_NORETURN, but this is not checked. If the + * function does return the application will crash via an abort() or similar + * system level call. + * + * If you get a warning here while building the library you may need to make + * changes to ensure that pnglibconf.h records the calling convention used by + * your compiler. This may be very difficult - try using a different compiler + * to build the library! + */ +PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); +#endif + +/* Transform masks for the high-level interface */ +#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ +#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ +#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ +#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ +#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ +#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ +#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ +#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ +#define PNG_TRANSFORM_BGR 0x0080 /* read and write */ +#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ +#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ +#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ +#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ +/* Added to libpng-1.2.34 */ +#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER +#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ +/* Added to libpng-1.4.0 */ +#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ +/* Added to libpng-1.5.4 */ +#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ +#if INT_MAX >= 0x8000 /* else this might break */ +#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ +#endif + +/* Flags for MNG supported features */ +#define PNG_FLAG_MNG_EMPTY_PLTE 0x01 +#define PNG_FLAG_MNG_FILTER_64 0x04 +#define PNG_ALL_MNG_FEATURES 0x05 + +/* NOTE: prior to 1.5 these functions had no 'API' style declaration, + * this allowed the zlib default functions to be used on Windows + * platforms. In 1.5 the zlib default malloc (which just calls malloc and + * ignores the first argument) should be completely compatible with the + * following. + */ +typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, + png_alloc_size_t)); +typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); + +/* Section 4: exported functions + * Here are the function definitions most commonly used. This is not + * the place to find out how to use libpng. See libpng-manual.txt for the + * full explanation, see example.c for the summary. This just provides + * a simple one line description of the use of each function. + * + * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in + * pngconf.h and in the *.dfn files in the scripts directory. + * + * PNG_EXPORT(ordinal, type, name, (args)); + * + * ordinal: ordinal that is used while building + * *.def files. The ordinal value is only + * relevant when preprocessing png.h with + * the *.dfn files for building symbol table + * entries, and are removed by pngconf.h. + * type: return type of the function + * name: function name + * args: function arguments, with types + * + * When we wish to append attributes to a function prototype we use + * the PNG_EXPORTA() macro instead. + * + * PNG_EXPORTA(ordinal, type, name, (args), attributes); + * + * ordinal, type, name, and args: same as in PNG_EXPORT(). + * attributes: function attributes + */ + +/* Returns the version number of the library */ +PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); + +/* Tell lib we have already handled the first <num_bytes> magic bytes. + * Handling more than 8 bytes from the beginning of the file is an error. + */ +PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); + +/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a + * PNG file. Returns zero if the supplied bytes match the 8-byte PNG + * signature, and non-zero otherwise. Having num_to_check == 0 or + * start > 7 will always fail (ie return non-zero). + */ +PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start, + size_t num_to_check)); + +/* Simple signature checking function. This is the same as calling + * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). + */ +#define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) + +/* Allocate and initialize png_ptr struct for reading, and any other memory. */ +PNG_EXPORTA(4, png_structp, png_create_read_struct, + (png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn), + PNG_ALLOCATED); + +/* Allocate and initialize png_ptr struct for writing, and any other memory */ +PNG_EXPORTA(5, png_structp, png_create_write_struct, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn), + PNG_ALLOCATED); + +PNG_EXPORT(6, size_t, png_get_compression_buffer_size, + (png_const_structrp png_ptr)); + +PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, + size_t size)); + +/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp + * match up. + */ +#ifdef PNG_SETJMP_SUPPORTED +/* This function returns the jmp_buf built in to *png_ptr. It must be + * supplied with an appropriate 'longjmp' function to use on that jmp_buf + * unless the default error function is overridden in which case NULL is + * acceptable. The size of the jmp_buf is checked against the actual size + * allocated by the library - the call will return NULL on a mismatch + * indicating an ABI mismatch. + */ +PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, + png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); +# define png_jmpbuf(png_ptr) \ + (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) +#else +# define png_jmpbuf(png_ptr) \ + (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) +#endif +/* This function should be used by libpng applications in place of + * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it + * will use it; otherwise it will call PNG_ABORT(). This function was + * added in libpng-1.5.0. + */ +PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), + PNG_NORETURN); + +#ifdef PNG_READ_SUPPORTED +/* Reset the compression stream */ +PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); +#endif + +/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ +#ifdef PNG_USER_MEM_SUPPORTED +PNG_EXPORTA(11, png_structp, png_create_read_struct_2, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn, + png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), + PNG_ALLOCATED); +PNG_EXPORTA(12, png_structp, png_create_write_struct_2, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn, + png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), + PNG_ALLOCATED); +#endif + +/* Write the PNG file signature. */ +PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); + +/* Write a PNG chunk - size, type, (optional) data, CRC. */ +PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep + chunk_name, png_const_bytep data, size_t length)); + +/* Write the start of a PNG chunk - length and chunk name. */ +PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, + png_const_bytep chunk_name, png_uint_32 length)); + +/* Write the data of a PNG chunk started with png_write_chunk_start(). */ +PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, + png_const_bytep data, size_t length)); + +/* Finish a chunk started with png_write_chunk_start() (includes CRC). */ +PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); + +/* Allocate and initialize the info structure */ +PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), + PNG_ALLOCATED); + +/* DEPRECATED: this function allowed init structures to be created using the + * default allocation method (typically malloc). Use is deprecated in 1.6.0 and + * the API will be removed in the future. + */ +PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, + size_t png_info_struct_size), PNG_DEPRECATED); + +/* Writes all the PNG information before the image. */ +PNG_EXPORT(20, void, png_write_info_before_PLTE, + (png_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(21, void, png_write_info, + (png_structrp png_ptr, png_const_inforp info_ptr)); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the information before the actual image data. */ +PNG_EXPORT(22, void, png_read_info, + (png_structrp png_ptr, png_inforp info_ptr)); +#endif + +#ifdef PNG_TIME_RFC1123_SUPPORTED + /* Convert to a US string format: there is no localization support in this + * routine. The original implementation used a 29 character buffer in + * png_struct, this will be removed in future versions. + */ +#if PNG_LIBPNG_VER < 10700 +/* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ +PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, + png_const_timep ptime),PNG_DEPRECATED); +#endif +PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], + png_const_timep ptime)); +#endif + +#ifdef PNG_CONVERT_tIME_SUPPORTED +/* Convert from a struct tm to png_time */ +PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, + const struct tm * ttime)); + +/* Convert from time_t to png_time. Uses gmtime() */ +PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); +#endif /* CONVERT_tIME */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ +PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); +PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); +PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); +PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_EXPAND_16_SUPPORTED +/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion + * of a tRNS chunk if present. + */ +PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* Use blue, green, red order for pixels. */ +PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +/* Expand the grayscale to 24-bit RGB if necessary. */ +PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +/* Reduce RGB to grayscale. */ +#define PNG_ERROR_ACTION_NONE 1 +#define PNG_ERROR_ACTION_WARN 2 +#define PNG_ERROR_ACTION_ERROR 3 +#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ + +PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, + int error_action, double red, double green)) +PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, + int error_action, png_fixed_point red, png_fixed_point green)) + +PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp + png_ptr)); +#endif + +#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED +PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, + png_colorp palette)); +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED +/* How the alpha channel is interpreted - this affects how the color channels + * of a PNG file are returned to the calling application when an alpha channel, + * or a tRNS chunk in a palette file, is present. + * + * This has no effect on the way pixels are written into a PNG output + * datastream. The color samples in a PNG datastream are never premultiplied + * with the alpha samples. + * + * The default is to return data according to the PNG specification: the alpha + * channel is a linear measure of the contribution of the pixel to the + * corresponding composited pixel, and the color channels are unassociated + * (not premultiplied). The gamma encoded color channels must be scaled + * according to the contribution and to do this it is necessary to undo + * the encoding, scale the color values, perform the composition and re-encode + * the values. This is the 'PNG' mode. + * + * The alternative is to 'associate' the alpha with the color information by + * storing color channel values that have been scaled by the alpha. + * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes + * (the latter being the two common names for associated alpha color channels). + * + * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha + * value is equal to the maximum value. + * + * The final choice is to gamma encode the alpha channel as well. This is + * broken because, in practice, no implementation that uses this choice + * correctly undoes the encoding before handling alpha composition. Use this + * choice only if other serious errors in the software or hardware you use + * mandate it; the typical serious error is for dark halos to appear around + * opaque areas of the composited PNG image because of arithmetic overflow. + * + * The API function png_set_alpha_mode specifies which of these choices to use + * with an enumerated 'mode' value and the gamma of the required output: + */ +#define PNG_ALPHA_PNG 0 /* according to the PNG standard */ +#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ +#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ +#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ +#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ +#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ + +PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, + double output_gamma)) +PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, + int mode, png_fixed_point output_gamma)) +#endif + +#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) +/* The output_gamma value is a screen gamma in libpng terminology: it expresses + * how to decode the output values, not how they are encoded. + */ +#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ +#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ +#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ +#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ +#endif + +/* The following are examples of calls to png_set_alpha_mode to achieve the + * required overall gamma correction and, where necessary, alpha + * premultiplication. + * + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); + * This is the default libpng handling of the alpha channel - it is not + * pre-multiplied into the color components. In addition the call states + * that the output is for a sRGB system and causes all PNG files without gAMA + * chunks to be assumed to be encoded using sRGB. + * + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); + * In this case the output is assumed to be something like an sRGB conformant + * display preceded by a power-law lookup table of power 1.45. This is how + * early Mac systems behaved. + * + * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); + * This is the classic Jim Blinn approach and will work in academic + * environments where everything is done by the book. It has the shortcoming + * of assuming that input PNG data with no gamma information is linear - this + * is unlikely to be correct unless the PNG files where generated locally. + * Most of the time the output precision will be so low as to show + * significant banding in dark areas of the image. + * + * png_set_expand_16(pp); + * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); + * This is a somewhat more realistic Jim Blinn inspired approach. PNG files + * are assumed to have the sRGB encoding if not marked with a gamma value and + * the output is always 16 bits per component. This permits accurate scaling + * and processing of the data. If you know that your input PNG files were + * generated locally you might need to replace PNG_DEFAULT_sRGB with the + * correct value for your system. + * + * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); + * If you just need to composite the PNG image onto an existing background + * and if you control the code that does this you can use the optimization + * setting. In this case you just copy completely opaque pixels to the + * output. For pixels that are not completely transparent (you just skip + * those) you do the composition math using png_composite or png_composite_16 + * below then encode the resultant 8-bit or 16-bit values to match the output + * encoding. + * + * Other cases + * If neither the PNG nor the standard linear encoding work for you because + * of the software or hardware you use then you have a big problem. The PNG + * case will probably result in halos around the image. The linear encoding + * will probably result in a washed out, too bright, image (it's actually too + * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably + * substantially reduce the halos. Alternatively try: + * + * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); + * This option will also reduce the halos, but there will be slight dark + * halos round the opaque parts of the image where the background is light. + * In the OPTIMIZED mode the halos will be light halos where the background + * is dark. Take your pick - the halos are unavoidable unless you can get + * your hardware/software fixed! (The OPTIMIZED approach is slightly + * faster.) + * + * When the default gamma of PNG files doesn't match the output gamma. + * If you have PNG files with no gamma information png_set_alpha_mode allows + * you to provide a default gamma, but it also sets the output gamma to the + * matching value. If you know your PNG files have a gamma that doesn't + * match the output you can take advantage of the fact that + * png_set_alpha_mode always sets the output gamma but only sets the PNG + * default if it is not already set: + * + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); + * The first call sets both the default and the output gamma values, the + * second call overrides the output gamma without changing the default. This + * is easier than achieving the same effect with png_set_gamma. You must use + * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will + * fire if more than one call to png_set_alpha_mode and png_set_background is + * made in the same read operation, however multiple calls with PNG_ALPHA_PNG + * are ignored. + */ + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED +PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) +PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) +PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) +/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ +PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, + int flags)); +/* The values of the PNG_FILLER_ defines should NOT be changed */ +# define PNG_FILLER_BEFORE 0 +# define PNG_FILLER_AFTER 1 +/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ +PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, + png_uint_32 filler, int flags)); +#endif /* READ_FILLER || WRITE_FILLER */ + +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* Swap bytes in 16-bit depth files. */ +PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) +/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ +PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ + defined(PNG_WRITE_PACKSWAP_SUPPORTED) +/* Swap packing order of pixels in bytes. */ +PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) +/* Converts files to legal bit depths. */ +PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p + true_bits)); +#endif + +#if defined(PNG_READ_INTERLACING_SUPPORTED) || \ + defined(PNG_WRITE_INTERLACING_SUPPORTED) +/* Have the code handle the interlacing. Returns the number of passes. + * MUST be called before png_read_update_info or png_start_read_image, + * otherwise it will not have the desired effect. Note that it is still + * necessary to call png_read_row or png_read_rows png_get_image_height + * times for each pass. +*/ +PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +/* Invert monochrome files */ +PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +/* Handle alpha and tRNS by replacing with a background color. Prior to + * libpng-1.5.4 this API must not be called before the PNG file header has been + * read. Doing so will result in unexpected behavior and possible warnings or + * errors if the PNG file contains a bKGD chunk. + */ +PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, double background_gamma)) +PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, png_fixed_point background_gamma)) +#endif +#ifdef PNG_READ_BACKGROUND_SUPPORTED +# define PNG_BACKGROUND_GAMMA_UNKNOWN 0 +# define PNG_BACKGROUND_GAMMA_SCREEN 1 +# define PNG_BACKGROUND_GAMMA_FILE 2 +# define PNG_BACKGROUND_GAMMA_UNIQUE 3 +#endif + +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED +/* Scale a 16-bit depth file down to 8-bit, accurately. */ +PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED +#define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */ +/* Strip the second byte of information from a 16-bit depth file. */ +PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +/* Turn on quantizing, and reduce the palette to the number of colors + * available. + */ +PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, + png_colorp palette, int num_palette, int maximum_colors, + png_const_uint_16p histogram, int full_quantize)); +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* The threshold on gamma processing is configurable but hard-wired into the + * library. The following is the floating point variant. + */ +#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) + +/* Handle gamma correction. Screen_gamma=(display_exponent). + * NOTE: this API simply sets the screen and file gamma values. It will + * therefore override the value for gamma in a PNG file if it is called after + * the file header has been read - use with care - call before reading the PNG + * file for best results! + * + * These routines accept the same gamma values as png_set_alpha_mode (described + * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either + * API (floating point or fixed.) Notice, however, that the 'file_gamma' value + * is the inverse of a 'screen gamma' value. + */ +PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, + double screen_gamma, double override_file_gamma)) +PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, + png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) +#endif + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +/* Set how many lines between output flushes - 0 for no flushing */ +PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); +/* Flush the current PNG output buffer */ +PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); +#endif + +/* Optional update palette with requested transformations */ +PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); + +/* Optional call to update the users info structure */ +PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, + png_inforp info_ptr)); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read one or more rows of image data. */ +PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, + png_bytepp display_row, png_uint_32 num_rows)); +#endif + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read a row of data. */ +PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, + png_bytep display_row)); +#endif + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the whole image into memory at once. */ +PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); +#endif + +/* Write a row of image data */ +PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, + png_const_bytep row)); + +/* Write a few rows of image data: (*row) is not written; however, the type + * is declared as writeable to maintain compatibility with previous versions + * of libpng and to allow the 'display_row' array from read_rows to be passed + * unchanged to write_rows. + */ +PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, + png_uint_32 num_rows)); + +/* Write the image data */ +PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); + +/* Write the end of the PNG file. */ +PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, + png_inforp info_ptr)); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the end of the PNG file. */ +PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); +#endif + +/* Free any memory associated with the png_info_struct */ +PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, + png_infopp info_ptr_ptr)); + +/* Free any memory associated with the png_struct and the png_info_structs */ +PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, + png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); + +/* Free any memory associated with the png_struct and the png_info_structs */ +PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, + png_infopp info_ptr_ptr)); + +/* Set the libpng method of handling chunk CRC errors */ +PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, + int ancil_action)); + +/* Values for png_set_crc_action() say how to handle CRC errors in + * ancillary and critical chunks, and whether to use the data contained + * therein. Note that it is impossible to "discard" data in a critical + * chunk. For versions prior to 0.90, the action was always error/quit, + * whereas in version 0.90 and later, the action for CRC errors in ancillary + * chunks is warn/discard. These values should NOT be changed. + * + * value action:critical action:ancillary + */ +#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ +#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ +#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ +#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ +#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ +#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ + +#ifdef PNG_WRITE_SUPPORTED +/* These functions give the user control over the scan-line filtering in + * libpng and the compression methods used by zlib. These functions are + * mainly useful for testing, as the defaults should work with most users. + * Those users who are tight on memory or want faster performance at the + * expense of compression can modify them. See the compression library + * header file (zlib.h) for an explination of the compression functions. + */ + +/* Set the filtering method(s) used by libpng. Currently, the only valid + * value for "method" is 0. + */ +PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, + int filters)); +#endif /* WRITE */ + +/* Flags for png_set_filter() to say which filters to use. The flags + * are chosen so that they don't conflict with real filter types + * below, in case they are supplied instead of the #defined constants. + * These values should NOT be changed. + */ +#define PNG_NO_FILTERS 0x00 +#define PNG_FILTER_NONE 0x08 +#define PNG_FILTER_SUB 0x10 +#define PNG_FILTER_UP 0x20 +#define PNG_FILTER_AVG 0x40 +#define PNG_FILTER_PAETH 0x80 +#define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP) +#define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH) + +/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. + * These defines should NOT be changed. + */ +#define PNG_FILTER_VALUE_NONE 0 +#define PNG_FILTER_VALUE_SUB 1 +#define PNG_FILTER_VALUE_UP 2 +#define PNG_FILTER_VALUE_AVG 3 +#define PNG_FILTER_VALUE_PAETH 4 +#define PNG_FILTER_VALUE_LAST 5 + +#ifdef PNG_WRITE_SUPPORTED +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ +PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, + int heuristic_method, int num_weights, png_const_doublep filter_weights, + png_const_doublep filter_costs)) +PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, + (png_structrp png_ptr, int heuristic_method, int num_weights, + png_const_fixed_point_p filter_weights, + png_const_fixed_point_p filter_costs)) +#endif /* WRITE_WEIGHTED_FILTER */ + +/* The following are no longer used and will be removed from libpng-1.7: */ +#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ +#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ +#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ +#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ + +/* Set the library compression level. Currently, valid values range from + * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 + * (0 - no compression, 9 - "maximal" compression). Note that tests have + * shown that zlib compression levels 3-6 usually perform as well as level 9 + * for PNG images, and do considerably fewer caclulations. In the future, + * these values may not correspond directly to the zlib compression levels. + */ +#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED +PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, + int level)); + +PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, + int mem_level)); + +PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, + int strategy)); + +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, + int window_bits)); + +PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, + int method)); +#endif /* WRITE_CUSTOMIZE_COMPRESSION */ + +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED +/* Also set zlib parameters for compressing non-IDAT chunks */ +PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, + int level)); + +PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, + int mem_level)); + +PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, + int strategy)); + +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +PNG_EXPORT(225, void, png_set_text_compression_window_bits, + (png_structrp png_ptr, int window_bits)); + +PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, + int method)); +#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ +#endif /* WRITE */ + +/* These next functions are called for input/output, memory, and error + * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, + * and call standard C I/O routines such as fread(), fwrite(), and + * fprintf(). These functions can be made to use other I/O routines + * at run time for those applications that need to handle I/O in a + * different manner by calling png_set_???_fn(). See libpng-manual.txt for + * more information. + */ + +#ifdef PNG_STDIO_SUPPORTED +/* Initialize the input/output for the PNG file to the default functions. */ +PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); +#endif + +/* Replace the (error and abort), and warning functions with user + * supplied functions. If no messages are to be printed you must still + * write and use replacement functions. The replacement error_fn should + * still do a longjmp to the last setjmp location if you are using this + * method of error handling. If error_fn or warning_fn is NULL, the + * default function will be used. + */ + +PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, + png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); + +/* Return the user pointer associated with the error functions */ +PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); + +/* Replace the default data output functions with a user supplied one(s). + * If buffered output is not used, then output_flush_fn can be set to NULL. + * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time + * output_flush_fn will be ignored (and thus can be NULL). + * It is probably a mistake to use NULL for output_flush_fn if + * write_data_fn is not also NULL unless you have built libpng with + * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's + * default flush function, which uses the standard *FILE structure, will + * be used. + */ +PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, + png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); + +/* Replace the default data input function with a user supplied one. */ +PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, + png_rw_ptr read_data_fn)); + +/* Return the user pointer associated with the I/O functions */ +PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); + +PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, + png_read_status_ptr read_row_fn)); + +PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, + png_write_status_ptr write_row_fn)); + +#ifdef PNG_USER_MEM_SUPPORTED +/* Replace the default memory allocation functions with user supplied one(s). */ +PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, + png_malloc_ptr malloc_fn, png_free_ptr free_fn)); +/* Return the user pointer associated with the memory functions */ +PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); +#endif + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED +PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, + png_user_transform_ptr read_user_transform_fn)); +#endif + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED +PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, + png_user_transform_ptr write_user_transform_fn)); +#endif + +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, + png_voidp user_transform_ptr, int user_transform_depth, + int user_transform_channels)); +/* Return the user pointer associated with the user transform functions */ +PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, + (png_const_structrp png_ptr)); +#endif + +#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED +/* Return information about the row currently being processed. Note that these + * APIs do not fail but will return unexpected results if called outside a user + * transform callback. Also note that when transforming an interlaced image the + * row number is the row number within the sub-image of the interlace pass, so + * the value will increase to the height of the sub-image (not the full image) + * then reset to 0 for the next pass. + * + * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to + * find the output pixel (x,y) given an interlaced sub-image pixel + * (row,col,pass). (See below for these macros.) + */ +PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); +PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); +#endif + +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED +/* This callback is called only for *unknown* chunks. If + * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known + * chunks to be treated as unknown, however in this case the callback must do + * any processing required by the chunk (e.g. by calling the appropriate + * png_set_ APIs.) + * + * There is no write support - on write, by default, all the chunks in the + * 'unknown' list are written in the specified position. + * + * The integer return from the callback function is interpreted thus: + * + * negative: An error occurred; png_chunk_error will be called. + * zero: The chunk was not handled, the chunk will be saved. A critical + * chunk will cause an error at this point unless it is to be saved. + * positive: The chunk was handled, libpng will ignore/discard it. + * + * See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about + * how this behavior will change in libpng 1.7 + */ +PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, + png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); +#endif + +#ifdef PNG_USER_CHUNKS_SUPPORTED +PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); +#endif + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +/* Sets the function callbacks for the push reader, and a pointer to a + * user-defined structure available to the callback functions. + */ +PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, + png_voidp progressive_ptr, png_progressive_info_ptr info_fn, + png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); + +/* Returns the user pointer associated with the push read functions */ +PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, + (png_const_structrp png_ptr)); + +/* Function to be called when data becomes available */ +PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, + png_inforp info_ptr, png_bytep buffer, size_t buffer_size)); + +/* A function which may be called *only* within png_process_data to stop the + * processing of any more data. The function returns the number of bytes + * remaining, excluding any that libpng has cached internally. A subsequent + * call to png_process_data must supply these bytes again. If the argument + * 'save' is set to true the routine will first save all the pending data and + * will always return 0. + */ +PNG_EXPORT(219, size_t, png_process_data_pause, (png_structrp, int save)); + +/* A function which may be called *only* outside (after) a call to + * png_process_data. It returns the number of bytes of data to skip in the + * input. Normally it will return 0, but if it returns a non-zero value the + * application must skip than number of bytes of input data and pass the + * following data to the next call to png_process_data. + */ +PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); + +/* Function that combines rows. 'new_row' is a flag that should come from + * the callback and be non-NULL if anything needs to be done; the library + * stores its own version of the new data internally and ignores the passed + * in value. + */ +PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, + png_bytep old_row, png_const_bytep new_row)); +#endif /* PROGRESSIVE_READ */ + +PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED); +/* Added at libpng version 1.4.0 */ +PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED); + +/* Added at libpng version 1.2.4 */ +PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED); + +/* Frees a pointer allocated by png_malloc() */ +PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); + +/* Free data that was allocated internally */ +PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_32 free_me, int num)); + +/* Reassign responsibility for freeing existing data, whether allocated + * by libpng or by the application; this works on the png_info structure passed + * in, it does not change the state for other png_info structures. + * + * It is unlikely that this function works correctly as of 1.6.0 and using it + * may result either in memory leaks or double free of allocated data. + */ +PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr, + png_inforp info_ptr, int freer, png_uint_32 mask)); + +/* Assignments for png_data_freer */ +#define PNG_DESTROY_WILL_FREE_DATA 1 +#define PNG_SET_WILL_FREE_DATA 1 +#define PNG_USER_WILL_FREE_DATA 2 +/* Flags for png_ptr->free_me and info_ptr->free_me */ +#define PNG_FREE_HIST 0x0008U +#define PNG_FREE_ICCP 0x0010U +#define PNG_FREE_SPLT 0x0020U +#define PNG_FREE_ROWS 0x0040U +#define PNG_FREE_PCAL 0x0080U +#define PNG_FREE_SCAL 0x0100U +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +# define PNG_FREE_UNKN 0x0200U +#endif +/* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */ +#define PNG_FREE_PLTE 0x1000U +#define PNG_FREE_TRNS 0x2000U +#define PNG_FREE_TEXT 0x4000U +#define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */ +#define PNG_FREE_ALL 0xffffU +#define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ + +#ifdef PNG_USER_MEM_SUPPORTED +PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); +PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, + png_voidp ptr), PNG_DEPRECATED); +#endif + +#ifdef PNG_ERROR_TEXT_SUPPORTED +/* Fatal error in PNG image of libpng - can't continue */ +PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, + png_const_charp error_message), PNG_NORETURN); + +/* The same, but the chunk name is prepended to the error string. */ +PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, + png_const_charp error_message), PNG_NORETURN); + +#else +/* Fatal error in PNG image of libpng - can't continue */ +PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); +# define png_error(s1,s2) png_err(s1) +# define png_chunk_error(s1,s2) png_err(s1) +#endif + +#ifdef PNG_WARNINGS_SUPPORTED +/* Non-fatal error in libpng. Can continue, but may have a problem. */ +PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, + png_const_charp warning_message)); + +/* Non-fatal error in libpng, chunk name is prepended to message. */ +PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, + png_const_charp warning_message)); +#else +# define png_warning(s1,s2) ((void)(s1)) +# define png_chunk_warning(s1,s2) ((void)(s1)) +#endif + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +/* Benign error in libpng. Can continue, but may have a problem. + * User can choose whether to handle as a fatal error or as a warning. */ +PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, + png_const_charp warning_message)); + +#ifdef PNG_READ_SUPPORTED +/* Same, chunk name is prepended to message (only during read) */ +PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, + png_const_charp warning_message)); +#endif + +PNG_EXPORT(109, void, png_set_benign_errors, + (png_structrp png_ptr, int allowed)); +#else +# ifdef PNG_ALLOW_BENIGN_ERRORS +# define png_benign_error png_warning +# define png_chunk_benign_error png_chunk_warning +# else +# define png_benign_error png_error +# define png_chunk_benign_error png_chunk_error +# endif +#endif + +/* The png_set_<chunk> functions are for storing values in the png_info_struct. + * Similarly, the png_get_<chunk> calls are used to read values from the + * png_info_struct, either storing the parameters in the passed variables, or + * setting pointers into the png_info_struct where the data is stored. The + * png_get_<chunk> functions return a non-zero value if the data was available + * in info_ptr, or return zero and do not change any of the parameters if the + * data was not available. + * + * These functions should be used instead of directly accessing png_info + * to avoid problems with future changes in the size and internal layout of + * png_info_struct. + */ +/* Returns "flag" if chunk data is valid in info_ptr. */ +PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 flag)); + +/* Returns number of bytes needed to hold a transformed row. */ +PNG_EXPORT(111, size_t, png_get_rowbytes, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +#ifdef PNG_INFO_IMAGE_SUPPORTED +/* Returns row_pointers, which is an array of pointers to scanlines that was + * returned from png_read_png(). + */ +PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Set row_pointers, which is an array of pointers to scanlines for use + * by png_write_png(). + */ +PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, + png_inforp info_ptr, png_bytepp row_pointers)); +#endif + +/* Returns number of color channels in image. */ +PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +#ifdef PNG_EASY_ACCESS_SUPPORTED +/* Returns image width in pixels. */ +PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image height in pixels. */ +PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image bit_depth. */ +PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image color_type. */ +PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image filter_type. */ +PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image interlace_type. */ +PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image compression_type. */ +PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image resolution in pixels per meter, from pHYs chunk data. */ +PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +/* Returns pixel aspect ratio, computed from pHYs chunk data. */ +PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) +PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) + +/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ +PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +#endif /* EASY_ACCESS */ + +#ifdef PNG_READ_SUPPORTED +/* Returns pointer to signature string read from PNG header */ +PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); +#endif + +#ifdef PNG_bKGD_SUPPORTED +PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, + png_inforp info_ptr, png_color_16p *background)); +#endif + +#ifdef PNG_bKGD_SUPPORTED +PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_color_16p background)); +#endif + +#ifdef PNG_cHRM_SUPPORTED +PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, + png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, + double *red_y, double *green_x, double *green_y, double *blue_x, + double *blue_y)) +PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, + png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, + double *green_X, double *green_Y, double *green_Z, double *blue_X, + double *blue_Y, double *blue_Z)) +PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *int_white_x, png_fixed_point *int_white_y, + png_fixed_point *int_red_x, png_fixed_point *int_red_y, + png_fixed_point *int_green_x, png_fixed_point *int_green_y, + png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) +PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *int_red_X, png_fixed_point *int_red_Y, + png_fixed_point *int_red_Z, png_fixed_point *int_green_X, + png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, + png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, + png_fixed_point *int_blue_Z)) +#endif + +#ifdef PNG_cHRM_SUPPORTED +PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, + png_inforp info_ptr, + double white_x, double white_y, double red_x, double red_y, double green_x, + double green_y, double blue_x, double blue_y)) +PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, + png_inforp info_ptr, double red_X, double red_Y, double red_Z, + double green_X, double green_Y, double green_Z, double blue_X, + double blue_Y, double blue_Z)) +PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, + png_inforp info_ptr, png_fixed_point int_white_x, + png_fixed_point int_white_y, png_fixed_point int_red_x, + png_fixed_point int_red_y, png_fixed_point int_green_x, + png_fixed_point int_green_y, png_fixed_point int_blue_x, + png_fixed_point int_blue_y)) +PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, + png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, + png_fixed_point int_red_Z, png_fixed_point int_green_X, + png_fixed_point int_green_Y, png_fixed_point int_green_Z, + png_fixed_point int_blue_X, png_fixed_point int_blue_Y, + png_fixed_point int_blue_Z)) +#endif + +#ifdef PNG_eXIf_SUPPORTED +PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr, + png_inforp info_ptr, png_bytep *exif)); +PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr, + png_inforp info_ptr, png_bytep exif)); + +PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif)); +PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_32 num_exif, png_bytep exif)); +#endif + +#ifdef PNG_gAMA_SUPPORTED +PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, + png_const_inforp info_ptr, double *file_gamma)) +PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *int_file_gamma)) +#endif + +#ifdef PNG_gAMA_SUPPORTED +PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, + png_inforp info_ptr, double file_gamma)) +PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, + png_inforp info_ptr, png_fixed_point int_file_gamma)) +#endif + +#ifdef PNG_hIST_SUPPORTED +PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_16p *hist)); +PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_uint_16p hist)); +#endif + +PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, + int *bit_depth, int *color_type, int *interlace_method, + int *compression_method, int *filter_method)); + +PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_method, int compression_method, + int filter_method)); + +#ifdef PNG_oFFs_SUPPORTED +PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, + int *unit_type)); +#endif + +#ifdef PNG_oFFs_SUPPORTED +PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, + png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, + int unit_type)); +#endif + +#ifdef PNG_pCAL_SUPPORTED +PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, + png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, + png_int_32 *X1, int *type, int *nparams, png_charp *units, + png_charpp *params)); +#endif + +#ifdef PNG_pCAL_SUPPORTED +PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, + int type, int nparams, png_const_charp units, png_charpp params)); +#endif + +#ifdef PNG_pHYs_SUPPORTED +PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, + int *unit_type)); +#endif + +#ifdef PNG_pHYs_SUPPORTED +PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); +#endif + +PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr, + png_inforp info_ptr, png_colorp *palette, int *num_palette)); + +PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, + png_inforp info_ptr, png_const_colorp palette, int num_palette)); + +#ifdef PNG_sBIT_SUPPORTED +PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, + png_inforp info_ptr, png_color_8p *sig_bit)); +#endif + +#ifdef PNG_sBIT_SUPPORTED +PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_color_8p sig_bit)); +#endif + +#ifdef PNG_sRGB_SUPPORTED +PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, + png_const_inforp info_ptr, int *file_srgb_intent)); +#endif + +#ifdef PNG_sRGB_SUPPORTED +PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, + png_inforp info_ptr, int srgb_intent)); +PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, + png_inforp info_ptr, int srgb_intent)); +#endif + +#ifdef PNG_iCCP_SUPPORTED +PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, + png_inforp info_ptr, png_charpp name, int *compression_type, + png_bytepp profile, png_uint_32 *proflen)); +#endif + +#ifdef PNG_iCCP_SUPPORTED +PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_charp name, int compression_type, + png_const_bytep profile, png_uint_32 proflen)); +#endif + +#ifdef PNG_sPLT_SUPPORTED +PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, + png_inforp info_ptr, png_sPLT_tpp entries)); +#endif + +#ifdef PNG_sPLT_SUPPORTED +PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); +#endif + +#ifdef PNG_TEXT_SUPPORTED +/* png_get_text also returns the number of text chunks in *num_text */ +PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, + png_inforp info_ptr, png_textp *text_ptr, int *num_text)); +#endif + +/* Note while png_set_text() will accept a structure whose text, + * language, and translated keywords are NULL pointers, the structure + * returned by png_get_text will always contain regular + * zero-terminated C strings. They might be empty strings but + * they will never be NULL pointers. + */ + +#ifdef PNG_TEXT_SUPPORTED +PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_textp text_ptr, int num_text)); +#endif + +#ifdef PNG_tIME_SUPPORTED +PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, + png_inforp info_ptr, png_timep *mod_time)); +#endif + +#ifdef PNG_tIME_SUPPORTED +PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_timep mod_time)); +#endif + +#ifdef PNG_tRNS_SUPPORTED +PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, + png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, + png_color_16p *trans_color)); +#endif + +#ifdef PNG_tRNS_SUPPORTED +PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, + png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, + png_const_color_16p trans_color)); +#endif + +#ifdef PNG_sCAL_SUPPORTED +PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, + png_const_inforp info_ptr, int *unit, double *width, double *height)) +#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ + defined(PNG_FLOATING_POINT_SUPPORTED) +/* NOTE: this API is currently implemented using floating point arithmetic, + * consequently it can only be used on systems with floating point support. + * In any case the range of values supported by png_fixed_point is small and it + * is highly recommended that png_get_sCAL_s be used instead. + */ +PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, + png_fixed_point *width, png_fixed_point *height)) +#endif +PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, + (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, + png_charpp swidth, png_charpp sheight)); + +PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, + png_inforp info_ptr, int unit, double width, double height)) +PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, + png_inforp info_ptr, int unit, png_fixed_point width, + png_fixed_point height)) +PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, + png_inforp info_ptr, int unit, + png_const_charp swidth, png_const_charp sheight)); +#endif /* sCAL */ + +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED +/* Provide the default handling for all unknown chunks or, optionally, for + * specific unknown chunks. + * + * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was + * ignored and the default was used, the per-chunk setting only had an effect on + * write. If you wish to have chunk-specific handling on read in code that must + * work on earlier versions you must use a user chunk callback to specify the + * desired handling (keep or discard.) + * + * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The + * parameter is interpreted as follows: + * + * READ: + * PNG_HANDLE_CHUNK_AS_DEFAULT: + * Known chunks: do normal libpng processing, do not keep the chunk (but + * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) + * Unknown chunks: for a specific chunk use the global default, when used + * as the default discard the chunk data. + * PNG_HANDLE_CHUNK_NEVER: + * Discard the chunk data. + * PNG_HANDLE_CHUNK_IF_SAFE: + * Keep the chunk data if the chunk is not critical else raise a chunk + * error. + * PNG_HANDLE_CHUNK_ALWAYS: + * Keep the chunk data. + * + * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, + * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent + * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks + * it simply resets the behavior to the libpng default. + * + * INTERACTION WITH USER CHUNK CALLBACKS: + * The per-chunk handling is always used when there is a png_user_chunk_ptr + * callback and the callback returns 0; the chunk is then always stored *unless* + * it is critical and the per-chunk setting is other than ALWAYS. Notice that + * the global default is *not* used in this case. (In effect the per-chunk + * value is incremented to at least IF_SAFE.) + * + * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and + * per-chunk defaults will be honored. If you want to preserve the current + * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE + * as the default - if you don't do this libpng 1.6 will issue a warning. + * + * If you want unhandled unknown chunks to be discarded in libpng 1.6 and + * earlier simply return '1' (handled). + * + * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: + * If this is *not* set known chunks will always be handled by libpng and + * will never be stored in the unknown chunk list. Known chunks listed to + * png_set_keep_unknown_chunks will have no effect. If it is set then known + * chunks listed with a keep other than AS_DEFAULT will *never* be processed + * by libpng, in addition critical chunks must either be processed by the + * callback or saved. + * + * The IHDR and IEND chunks must not be listed. Because this turns off the + * default handling for chunks that would otherwise be recognized the + * behavior of libpng transformations may well become incorrect! + * + * WRITE: + * When writing chunks the options only apply to the chunks specified by + * png_set_unknown_chunks (below), libpng will *always* write known chunks + * required by png_set_ calls and will always write the core critical chunks + * (as required for PLTE). + * + * Each chunk in the png_set_unknown_chunks list is looked up in the + * png_set_keep_unknown_chunks list to find the keep setting, this is then + * interpreted as follows: + * + * PNG_HANDLE_CHUNK_AS_DEFAULT: + * Write safe-to-copy chunks and write other chunks if the global + * default is set to _ALWAYS, otherwise don't write this chunk. + * PNG_HANDLE_CHUNK_NEVER: + * Do not write the chunk. + * PNG_HANDLE_CHUNK_IF_SAFE: + * Write the chunk if it is safe-to-copy, otherwise do not write it. + * PNG_HANDLE_CHUNK_ALWAYS: + * Write the chunk. + * + * Note that the default behavior is effectively the opposite of the read case - + * in read unknown chunks are not stored by default, in write they are written + * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different + * - on write the safe-to-copy bit is checked, on read the critical bit is + * checked and on read if the chunk is critical an error will be raised. + * + * num_chunks: + * =========== + * If num_chunks is positive, then the "keep" parameter specifies the manner + * for handling only those chunks appearing in the chunk_list array, + * otherwise the chunk list array is ignored. + * + * If num_chunks is 0 the "keep" parameter specifies the default behavior for + * unknown chunks, as described above. + * + * If num_chunks is negative, then the "keep" parameter specifies the manner + * for handling all unknown chunks plus all chunks recognized by libpng + * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to + * be processed by libpng. + */ +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, + int keep, png_const_bytep chunk_list, int num_chunks)); +#endif /* HANDLE_AS_UNKNOWN */ + +/* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; + * the result is therefore true (non-zero) if special handling is required, + * false for the default handling. + */ +PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, + png_const_bytep chunk_name)); +#endif /* SET_UNKNOWN_CHUNKS */ + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_unknown_chunkp unknowns, + int num_unknowns)); + /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added + * unknowns to the location currently stored in the png_struct. This is + * invariably the wrong value on write. To fix this call the following API + * for each chunk in the list with the correct location. If you know your + * code won't be compiled on earlier versions you can rely on + * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing + * the correct thing. + */ + +PNG_EXPORT(175, void, png_set_unknown_chunk_location, + (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); + +PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, + png_inforp info_ptr, png_unknown_chunkpp entries)); +#endif + +/* Png_free_data() will turn off the "valid" flag for anything it frees. + * If you need to turn it off for a chunk that your application has freed, + * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); + */ +PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, + png_inforp info_ptr, int mask)); + +#ifdef PNG_INFO_IMAGE_SUPPORTED +/* The "params" pointer is currently not used and is for future expansion. */ +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, + int transforms, png_voidp params)); +#endif +#ifdef PNG_WRITE_SUPPORTED +PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, + int transforms, png_voidp params)); +#endif +#endif + +PNG_EXPORT(180, png_const_charp, png_get_copyright, + (png_const_structrp png_ptr)); +PNG_EXPORT(181, png_const_charp, png_get_header_ver, + (png_const_structrp png_ptr)); +PNG_EXPORT(182, png_const_charp, png_get_header_version, + (png_const_structrp png_ptr)); +PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, + (png_const_structrp png_ptr)); + +#ifdef PNG_MNG_FEATURES_SUPPORTED +PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, + png_uint_32 mng_features_permitted)); +#endif + +/* For use in png_set_keep_unknown, added to version 1.2.6 */ +#define PNG_HANDLE_CHUNK_AS_DEFAULT 0 +#define PNG_HANDLE_CHUNK_NEVER 1 +#define PNG_HANDLE_CHUNK_IF_SAFE 2 +#define PNG_HANDLE_CHUNK_ALWAYS 3 +#define PNG_HANDLE_CHUNK_LAST 4 + +/* Strip the prepended error numbers ("#nnn ") from error and warning + * messages before passing them to the error or warning handler. + */ +#ifdef PNG_ERROR_NUMBERS_SUPPORTED +PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, + png_uint_32 strip_mode)); +#endif + +/* Added in libpng-1.2.6 */ +#ifdef PNG_SET_USER_LIMITS_SUPPORTED +PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, + png_uint_32 user_width_max, png_uint_32 user_height_max)); +PNG_EXPORT(187, png_uint_32, png_get_user_width_max, + (png_const_structrp png_ptr)); +PNG_EXPORT(188, png_uint_32, png_get_user_height_max, + (png_const_structrp png_ptr)); +/* Added in libpng-1.4.0 */ +PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, + png_uint_32 user_chunk_cache_max)); +PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, + (png_const_structrp png_ptr)); +/* Added in libpng-1.4.1 */ +PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, + png_alloc_size_t user_chunk_cache_max)); +PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, + (png_const_structrp png_ptr)); +#endif + +#if defined(PNG_INCH_CONVERSIONS_SUPPORTED) +PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +PNG_FP_EXPORT(196, float, png_get_x_offset_inches, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) +#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ +PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) +#endif + +PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, + png_const_inforp info_ptr)) +#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ +PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) +#endif + +# ifdef PNG_pHYs_SUPPORTED +PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, + int *unit_type)); +# endif /* pHYs */ +#endif /* INCH_CONVERSIONS */ + +/* Added in libpng-1.4.0 */ +#ifdef PNG_IO_STATE_SUPPORTED +PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); + +/* Removed from libpng 1.6; use png_get_io_chunk_type. */ +PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), + PNG_DEPRECATED) + +PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, + (png_const_structrp png_ptr)); + +/* The flags returned by png_get_io_state() are the following: */ +# define PNG_IO_NONE 0x0000 /* no I/O at this moment */ +# define PNG_IO_READING 0x0001 /* currently reading */ +# define PNG_IO_WRITING 0x0002 /* currently writing */ +# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ +# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ +# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ +# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ +# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ +# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ +#endif /* IO_STATE */ + +/* Interlace support. The following macros are always defined so that if + * libpng interlace handling is turned off the macros may be used to handle + * interlaced images within the application. + */ +#define PNG_INTERLACE_ADAM7_PASSES 7 + +/* Two macros to return the first row and first column of the original, + * full, image which appears in a given pass. 'pass' is in the range 0 + * to 6 and the result is in the range 0 to 7. + */ +#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) +#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) + +/* A macro to return the offset between pixels in the output row for a pair of + * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that + * follows. Note that ROW_OFFSET is the offset from one row to the next whereas + * COL_OFFSET is from one column to the next, within a row. + */ +#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) +#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) + +/* Two macros to help evaluate the number of rows or columns in each + * pass. This is expressed as a shift - effectively log2 of the number or + * rows or columns in each 8x8 tile of the original image. + */ +#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) +#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) + +/* Hence two macros to determine the number of rows or columns in a given + * pass of an image given its height or width. In fact these macros may + * return non-zero even though the sub-image is empty, because the other + * dimension may be empty for a small image. + */ +#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ + -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) +#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ + -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) + +/* For the reader row callbacks (both progressive and sequential) it is + * necessary to find the row in the output image given a row in an interlaced + * image, so two more macros: + */ +#define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ + (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) +#define PNG_COL_FROM_PASS_COL(x_in, pass) \ + (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) + +/* Two macros which return a boolean (0 or 1) saying whether the given row + * or column is in a particular pass. These use a common utility macro that + * returns a mask for a given pass - the offset 'off' selects the row or + * column version. The mask has the appropriate bit set for each column in + * the tile. + */ +#define PNG_PASS_MASK(pass,off) ( \ + ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ + ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) + +#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ + ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) +#define PNG_COL_IN_INTERLACE_PASS(x, pass) \ + ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) + +#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED +/* With these routines we avoid an integer divide, which will be slower on + * most machines. However, it does take more operations than the corresponding + * divide method, so it may be slower on a few RISC systems. There are two + * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. + * + * Note that the rounding factors are NOT supposed to be the same! 128 and + * 32768 are correct for the NODIV code; 127 and 32767 are correct for the + * standard method. + * + * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] + */ + + /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ + +# define png_composite(composite, fg, alpha, bg) \ + { \ + png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ + * (png_uint_16)(alpha) \ + + (png_uint_16)(bg)*(png_uint_16)(255 \ + - (png_uint_16)(alpha)) + 128); \ + (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \ + } + +# define png_composite_16(composite, fg, alpha, bg) \ + { \ + png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ + * (png_uint_32)(alpha) \ + + (png_uint_32)(bg)*(65535 \ + - (png_uint_32)(alpha)) + 32768); \ + (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \ + } + +#else /* Standard method using integer division */ + +# define png_composite(composite, fg, alpha, bg) \ + (composite) = \ + (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \ + (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ + 127) / 255)) + +# define png_composite_16(composite, fg, alpha, bg) \ + (composite) = \ + (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \ + (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ + 32767) / 65535)) +#endif /* READ_COMPOSITE_NODIV */ + +#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED +PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); +PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); +PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); +#endif + +PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, + png_const_bytep buf)); +/* No png_get_int_16 -- may be added if there's a real need for it. */ + +/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED +PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); +#endif +#ifdef PNG_SAVE_INT_32_SUPPORTED +PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); +#endif + +/* Place a 16-bit number into a buffer in PNG byte order. + * The parameter is declared unsigned int, not png_uint_16, + * just to avoid potential problems on pre-ANSI C compilers. + */ +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED +PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); +/* No png_save_int_16 -- may be added if there's a real need for it. */ +#endif + +#ifdef PNG_USE_READ_MACROS +/* Inline macros to do direct reads of bytes from the input buffer. + * The png_get_int_32() routine assumes we are using two's complement + * format for negative values, which is almost certainly true. + */ +# define PNG_get_uint_32(buf) \ + (((png_uint_32)(*(buf)) << 24) + \ + ((png_uint_32)(*((buf) + 1)) << 16) + \ + ((png_uint_32)(*((buf) + 2)) << 8) + \ + ((png_uint_32)(*((buf) + 3)))) + + /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the + * function) incorrectly returned a value of type png_uint_32. + */ +# define PNG_get_uint_16(buf) \ + ((png_uint_16) \ + (((unsigned int)(*(buf)) << 8) + \ + ((unsigned int)(*((buf) + 1))))) + +# define PNG_get_int_32(buf) \ + ((png_int_32)((*(buf) & 0x80) \ + ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \ + : (png_int_32)png_get_uint_32(buf))) + +/* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, + * but defining a macro name prefixed with PNG_PREFIX. + */ +# ifndef PNG_PREFIX +# define png_get_uint_32(buf) PNG_get_uint_32(buf) +# define png_get_uint_16(buf) PNG_get_uint_16(buf) +# define png_get_int_32(buf) PNG_get_int_32(buf) +# endif +#else +# ifdef PNG_PREFIX + /* No macros; revert to the (redefined) function */ +# define PNG_get_uint_32 (png_get_uint_32) +# define PNG_get_uint_16 (png_get_uint_16) +# define PNG_get_int_32 (png_get_int_32) +# endif +#endif + +#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED +PNG_EXPORT(242, void, png_set_check_for_invalid_index, + (png_structrp png_ptr, int allowed)); +# ifdef PNG_GET_PALETTE_MAX_SUPPORTED +PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, + png_const_infop info_ptr)); +# endif +#endif /* CHECK_FOR_INVALID_INDEX */ + +/******************************************************************************* + * Section 5: SIMPLIFIED API + ******************************************************************************* + * + * Please read the documentation in libpng-manual.txt (TODO: write said + * documentation) if you don't understand what follows. + * + * The simplified API hides the details of both libpng and the PNG file format + * itself. It allows PNG files to be read into a very limited number of + * in-memory bitmap formats or to be written from the same formats. If these + * formats do not accommodate your needs then you can, and should, use the more + * sophisticated APIs above - these support a wide variety of in-memory formats + * and a wide variety of sophisticated transformations to those formats as well + * as a wide variety of APIs to manipulate ancillary information. + * + * To read a PNG file using the simplified API: + * + * 1) Declare a 'png_image' structure (see below) on the stack, set the + * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL + * (this is REQUIRED, your program may crash if you don't do it.) + * 2) Call the appropriate png_image_begin_read... function. + * 3) Set the png_image 'format' member to the required sample format. + * 4) Allocate a buffer for the image and, if required, the color-map. + * 5) Call png_image_finish_read to read the image and, if required, the + * color-map into your buffers. + * + * There are no restrictions on the format of the PNG input itself; all valid + * color types, bit depths, and interlace methods are acceptable, and the + * input image is transformed as necessary to the requested in-memory format + * during the png_image_finish_read() step. The only caveat is that if you + * request a color-mapped image from a PNG that is full-color or makes + * complex use of an alpha channel the transformation is extremely lossy and the + * result may look terrible. + * + * To write a PNG file using the simplified API: + * + * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. + * 2) Initialize the members of the structure that describe the image, setting + * the 'format' member to the format of the image samples. + * 3) Call the appropriate png_image_write... function with a pointer to the + * image and, if necessary, the color-map to write the PNG data. + * + * png_image is a structure that describes the in-memory format of an image + * when it is being read or defines the in-memory format of an image that you + * need to write: + */ +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) + +#define PNG_IMAGE_VERSION 1 + +typedef struct png_control *png_controlp; +typedef struct +{ + png_controlp opaque; /* Initialize to NULL, free with png_image_free */ + png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ + png_uint_32 width; /* Image width in pixels (columns) */ + png_uint_32 height; /* Image height in pixels (rows) */ + png_uint_32 format; /* Image format as defined below */ + png_uint_32 flags; /* A bit mask containing informational flags */ + png_uint_32 colormap_entries; + /* Number of entries in the color-map */ + + /* In the event of an error or warning the following field will be set to a + * non-zero value and the 'message' field will contain a '\0' terminated + * string with the libpng error or warning message. If both warnings and + * an error were encountered, only the error is recorded. If there + * are multiple warnings, only the first one is recorded. + * + * The upper 30 bits of this value are reserved, the low two bits contain + * a value as follows: + */ +# define PNG_IMAGE_WARNING 1 +# define PNG_IMAGE_ERROR 2 + /* + * The result is a two-bit code such that a value more than 1 indicates + * a failure in the API just called: + * + * 0 - no warning or error + * 1 - warning + * 2 - error + * 3 - error preceded by warning + */ +# define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) + + png_uint_32 warning_or_error; + + char message[64]; +} png_image, *png_imagep; + +/* The samples of the image have one to four channels whose components have + * original values in the range 0 to 1.0: + * + * 1: A single gray or luminance channel (G). + * 2: A gray/luminance channel and an alpha channel (GA). + * 3: Three red, green, blue color channels (RGB). + * 4: Three color channels and an alpha channel (RGBA). + * + * The components are encoded in one of two ways: + * + * a) As a small integer, value 0..255, contained in a single byte. For the + * alpha channel the original value is simply value/255. For the color or + * luminance channels the value is encoded according to the sRGB specification + * and matches the 8-bit format expected by typical display devices. + * + * The color/gray channels are not scaled (pre-multiplied) by the alpha + * channel and are suitable for passing to color management software. + * + * b) As a value in the range 0..65535, contained in a 2-byte integer. All + * channels can be converted to the original value by dividing by 65535; all + * channels are linear. Color channels use the RGB encoding (RGB end-points) of + * the sRGB specification. This encoding is identified by the + * PNG_FORMAT_FLAG_LINEAR flag below. + * + * When the simplified API needs to convert between sRGB and linear colorspaces, + * the actual sRGB transfer curve defined in the sRGB specification (see the + * article at <https://en.wikipedia.org/wiki/SRGB>) is used, not the gamma=1/2.2 + * approximation used elsewhere in libpng. + * + * When an alpha channel is present it is expected to denote pixel coverage + * of the color or luminance channels and is returned as an associated alpha + * channel: the color/gray channels are scaled (pre-multiplied) by the alpha + * value. + * + * The samples are either contained directly in the image data, between 1 and 8 + * bytes per pixel according to the encoding, or are held in a color-map indexed + * by bytes in the image data. In the case of a color-map the color-map entries + * are individual samples, encoded as above, and the image data has one byte per + * pixel to select the relevant sample from the color-map. + */ + +/* PNG_FORMAT_* + * + * #defines to be used in png_image::format. Each #define identifies a + * particular layout of sample data and, if present, alpha values. There are + * separate defines for each of the two component encodings. + * + * A format is built up using single bit flag values. All combinations are + * valid. Formats can be built up from the flag values or you can use one of + * the predefined values below. When testing formats always use the FORMAT_FLAG + * macros to test for individual features - future versions of the library may + * add new flags. + * + * When reading or writing color-mapped images the format should be set to the + * format of the entries in the color-map then png_image_{read,write}_colormap + * called to read or write the color-map and set the format correctly for the + * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! + * + * NOTE: libpng can be built with particular features disabled. If you see + * compiler errors because the definition of one of the following flags has been + * compiled out it is because libpng does not have the required support. It is + * possible, however, for the libpng configuration to enable the format on just + * read or just write; in that case you may see an error at run time. You can + * guard against this by checking for the definition of the appropriate + * "_SUPPORTED" macro, one of: + * + * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED + */ +#define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ +#define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ +#define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */ +#define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ + +#ifdef PNG_FORMAT_BGR_SUPPORTED +# define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ +#endif + +#ifdef PNG_FORMAT_AFIRST_SUPPORTED +# define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ +#endif + +#define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */ + +/* Commonly used formats have predefined macros. + * + * First the single byte (sRGB) formats: + */ +#define PNG_FORMAT_GRAY 0 +#define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA +#define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) +#define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR +#define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) +#define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) +#define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) +#define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) +#define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) + +/* Then the linear 2-byte formats. When naming these "Y" is used to + * indicate a luminance (gray) channel. + */ +#define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR +#define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) +#define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) +#define PNG_FORMAT_LINEAR_RGB_ALPHA \ + (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) + +/* With color-mapped formats the image data is one byte for each pixel, the byte + * is an index into the color-map which is formatted as above. To obtain a + * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP + * to one of the above definitions, or you can use one of the definitions below. + */ +#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) + +/* PNG_IMAGE macros + * + * These are convenience macros to derive information from a png_image + * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the + * actual image sample values - either the entries in the color-map or the + * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values + * for the pixels and will always return 1 for color-mapped formats. The + * remaining macros return information about the rows in the image and the + * complete image. + * + * NOTE: All the macros that take a png_image::format parameter are compile time + * constants if the format parameter is, itself, a constant. Therefore these + * macros can be used in array declarations and case labels where required. + * Similarly the macros are also pre-processor constants (sizeof is not used) so + * they can be used in #if tests. + * + * First the information about the samples. + */ +#define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ + (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) + /* Return the total number of channels in a given format: 1..4 */ + +#define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ + ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) + /* Return the size in bytes of a single component of a pixel or color-map + * entry (as appropriate) in the image: 1 or 2. + */ + +#define PNG_IMAGE_SAMPLE_SIZE(fmt)\ + (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) + /* This is the size of the sample data for one sample. If the image is + * color-mapped it is the size of one color-map entry (and image pixels are + * one byte in size), otherwise it is the size of one image pixel. + */ + +#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ + (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) + /* The maximum size of the color-map required by the format expressed in a + * count of components. This can be used to compile-time allocate a + * color-map: + * + * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; + * + * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; + * + * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the + * information from one of the png_image_begin_read_ APIs and dynamically + * allocate the required memory. + */ + +/* Corresponding information about the pixels */ +#define PNG_IMAGE_PIXEL_(test,fmt)\ + (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) + +#define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ + PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) + /* The number of separate channels (components) in a pixel; 1 for a + * color-mapped image. + */ + +#define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ + PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) + /* The size, in bytes, of each component in a pixel; 1 for a color-mapped + * image. + */ + +#define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) + /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ + +/* Information about the whole row, or whole image */ +#define PNG_IMAGE_ROW_STRIDE(image)\ + (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) + /* Return the total number of components in a single row of the image; this + * is the minimum 'row stride', the minimum count of components between each + * row. For a color-mapped image this is the minimum number of bytes in a + * row. + * + * WARNING: this macro overflows for some images with more than one component + * and very large image widths. libpng will refuse to process an image where + * this macro would overflow. + */ + +#define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ + (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) + /* Return the size, in bytes, of an image buffer given a png_image and a row + * stride - the number of components to leave space for in each row. + * + * WARNING: this macro overflows a 32-bit integer for some large PNG images, + * libpng will refuse to process an image where such an overflow would occur. + */ + +#define PNG_IMAGE_SIZE(image)\ + PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) + /* Return the size, in bytes, of the image in memory given just a png_image; + * the row stride is the minimum stride required for the image. + */ + +#define PNG_IMAGE_COLORMAP_SIZE(image)\ + (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) + /* Return the size, in bytes, of the color-map of this image. If the image + * format is not a color-map format this will return a size sufficient for + * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if + * you don't want to allocate a color-map in this case. + */ + +/* PNG_IMAGE_FLAG_* + * + * Flags containing additional information about the image are held in the + * 'flags' field of png_image. + */ +#define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 + /* This indicates that the RGB values of the in-memory bitmap do not + * correspond to the red, green and blue end-points defined by sRGB. + */ + +#define PNG_IMAGE_FLAG_FAST 0x02 + /* On write emphasise speed over compression; the resultant PNG file will be + * larger but will be produced significantly faster, particular for large + * images. Do not use this option for images which will be distributed, only + * used it when producing intermediate files that will be read back in + * repeatedly. For a typical 24-bit image the option will double the read + * speed at the cost of increasing the image size by 25%, however for many + * more compressible images the PNG file can be 10 times larger with only a + * slight speed gain. + */ + +#define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 + /* On read if the image is a 16-bit per component image and there is no gAMA + * or sRGB chunk assume that the components are sRGB encoded. Notice that + * images output by the simplified API always have gamma information; setting + * this flag only affects the interpretation of 16-bit images from an + * external source. It is recommended that the application expose this flag + * to the user; the user can normally easily recognize the difference between + * linear and sRGB encoding. This flag has no effect on write - the data + * passed to the write APIs must have the correct encoding (as defined + * above.) + * + * If the flag is not set (the default) input 16-bit per component data is + * assumed to be linear. + * + * NOTE: the flag can only be set after the png_image_begin_read_ call, + * because that call initializes the 'flags' field. + */ + +#ifdef PNG_SIMPLIFIED_READ_SUPPORTED +/* READ APIs + * --------- + * + * The png_image passed to the read APIs must have been initialized by setting + * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) + */ +#ifdef PNG_STDIO_SUPPORTED +PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, + const char *file_name)); + /* The named file is opened for read and the image header is filled in + * from the PNG header in the file. + */ + +PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, + FILE* file)); + /* The PNG header is read from the stdio FILE object. */ +#endif /* STDIO */ + +PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, + png_const_voidp memory, size_t size)); + /* The PNG header is read from the given memory buffer. */ + +PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, + png_const_colorp background, void *buffer, png_int_32 row_stride, + void *colormap)); + /* Finish reading the image into the supplied buffer and clean up the + * png_image structure. + * + * row_stride is the step, in byte or 2-byte units as appropriate, + * between adjacent rows. A positive stride indicates that the top-most row + * is first in the buffer - the normal top-down arrangement. A negative + * stride indicates that the bottom-most row is first in the buffer. + * + * background need only be supplied if an alpha channel must be removed from + * a png_byte format and the removal is to be done by compositing on a solid + * color; otherwise it may be NULL and any composition will be done directly + * onto the buffer. The value is an sRGB color to use for the background, + * for grayscale output the green channel is used. + * + * background must be supplied when an alpha channel must be removed from a + * single byte color-mapped output format, in other words if: + * + * 1) The original format from png_image_begin_read_from_* had + * PNG_FORMAT_FLAG_ALPHA set. + * 2) The format set by the application does not. + * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and + * PNG_FORMAT_FLAG_LINEAR *not* set. + * + * For linear output removing the alpha channel is always done by compositing + * on black and background is ignored. + * + * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must + * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. + * image->colormap_entries will be updated to the actual number of entries + * written to the colormap; this may be less than the original value. + */ + +PNG_EXPORT(238, void, png_image_free, (png_imagep image)); + /* Free any data allocated by libpng in image->opaque, setting the pointer to + * NULL. May be called at any time after the structure is initialized. + */ +#endif /* SIMPLIFIED_READ */ + +#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED +/* WRITE APIS + * ---------- + * For write you must initialize a png_image structure to describe the image to + * be written. To do this use memset to set the whole structure to 0 then + * initialize fields describing your image. + * + * version: must be set to PNG_IMAGE_VERSION + * opaque: must be initialized to NULL + * width: image width in pixels + * height: image height in rows + * format: the format of the data (image and color-map) you wish to write + * flags: set to 0 unless one of the defined flags applies; set + * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB + * values do not correspond to the colors in sRGB. + * colormap_entries: set to the number of entries in the color-map (0 to 256) + */ +#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED +PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, + const char *file, int convert_to_8bit, const void *buffer, + png_int_32 row_stride, const void *colormap)); + /* Write the image to the named file. */ + +PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, + int convert_to_8_bit, const void *buffer, png_int_32 row_stride, + const void *colormap)); + /* Write the image to the given (FILE*). */ +#endif /* SIMPLIFIED_WRITE_STDIO */ + +/* With all write APIs if image is in one of the linear formats with 16-bit + * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG + * gamma encoded according to the sRGB specification, otherwise a 16-bit linear + * encoded PNG file is written. + * + * With color-mapped data formats the colormap parameter point to a color-map + * with at least image->colormap_entries encoded in the specified format. If + * the format is linear the written PNG color-map will be converted to sRGB + * regardless of the convert_to_8_bit flag. + * + * With all APIs row_stride is handled as in the read APIs - it is the spacing + * from one row to the next in component sized units (1 or 2 bytes) and if + * negative indicates a bottom-up row layout in the buffer. If row_stride is + * zero, libpng will calculate it for you from the image width and number of + * channels. + * + * Note that the write API does not support interlacing, sub-8-bit pixels or + * most ancillary chunks. If you need to write text chunks (e.g. for copyright + * notices) you need to use one of the other APIs. + */ + +PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory, + png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit, + const void *buffer, png_int_32 row_stride, const void *colormap)); + /* Write the image to the given memory buffer. The function both writes the + * whole PNG data stream to *memory and updates *memory_bytes with the count + * of bytes written. + * + * 'memory' may be NULL. In this case *memory_bytes is not read however on + * success the number of bytes which would have been written will still be + * stored in *memory_bytes. On failure *memory_bytes will contain 0. + * + * If 'memory' is not NULL it must point to memory[*memory_bytes] of + * writeable memory. + * + * If the function returns success memory[*memory_bytes] (if 'memory' is not + * NULL) contains the written PNG data. *memory_bytes will always be less + * than or equal to the original value. + * + * If the function returns false and *memory_bytes was not changed an error + * occurred during write. If *memory_bytes was changed, or is not 0 if + * 'memory' was NULL, the write would have succeeded but for the memory + * buffer being too small. *memory_bytes contains the required number of + * bytes and will be bigger that the original value. + */ + +#define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\ + row_stride, colormap)\ + png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\ + row_stride, colormap) + /* Return the amount of memory in 'size' required to compress this image. + * The png_image structure 'image' must be filled in as in the above + * function and must not be changed before the actual write call, the buffer + * and all other parameters must also be identical to that in the final + * write call. The 'size' variable need not be initialized. + * + * NOTE: the macro returns true/false, if false is returned 'size' will be + * set to zero and the write failed and probably will fail if tried again. + */ + +/* You can pre-allocate the buffer by making sure it is of sufficient size + * regardless of the amount of compression achieved. The buffer size will + * always be bigger than the original image and it will never be filled. The + * following macros are provided to assist in allocating the buffer. + */ +#define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height) + /* The number of uncompressed bytes in the PNG byte encoding of the image; + * uncompressing the PNG IDAT data will give this number of bytes. + * + * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this + * macro can because of the extra bytes used in the PNG byte encoding. You + * need to avoid this macro if your image size approaches 2^30 in width or + * height. The same goes for the remainder of these macros; they all produce + * bigger numbers than the actual in-memory image size. + */ +#ifndef PNG_ZLIB_MAX_SIZE +# define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U) + /* An upper bound on the number of compressed bytes given 'b' uncompressed + * bytes. This is based on deflateBounds() in zlib; different + * implementations of zlib compression may conceivably produce more data so + * if your zlib implementation is not zlib itself redefine this macro + * appropriately. + */ +#endif + +#define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\ + PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image)) + /* An upper bound on the size of the data in the PNG IDAT chunks. */ + +#define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\ + ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\ + (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\ + 12U+3U*(image).colormap_entries/*PLTE data*/+\ + (((image).format&PNG_FORMAT_FLAG_ALPHA)?\ + 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\ + 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size)) + /* A helper for the following macro; if your compiler cannot handle the + * following macro use this one with the result of + * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most + * compilers should handle this just fine.) + */ + +#define PNG_IMAGE_PNG_SIZE_MAX(image)\ + PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image)) + /* An upper bound on the total length of the PNG data stream for 'image'. + * The result is of type png_alloc_size_t, on 32-bit systems this may + * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will + * run out of buffer space but return a corrected size which should work. + */ +#endif /* SIMPLIFIED_WRITE */ +/******************************************************************************* + * END OF SIMPLIFIED API + ******************************************************************************/ +#endif /* SIMPLIFIED_{READ|WRITE} */ + +/******************************************************************************* + * Section 6: IMPLEMENTATION OPTIONS + ******************************************************************************* + * + * Support for arbitrary implementation-specific optimizations. The API allows + * particular options to be turned on or off. 'Option' is the number of the + * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given + * by the PNG_OPTION_ defines below. + * + * HARDWARE: normally hardware capabilities, such as the Intel SSE instructions, + * are detected at run time, however sometimes it may be impossible + * to do this in user mode, in which case it is necessary to discover + * the capabilities in an OS specific way. Such capabilities are + * listed here when libpng has support for them and must be turned + * ON by the application if present. + * + * SOFTWARE: sometimes software optimizations actually result in performance + * decrease on some architectures or systems, or with some sets of + * PNG images. 'Software' options allow such optimizations to be + * selected at run time. + */ +#ifdef PNG_SET_OPTION_SUPPORTED +#ifdef PNG_ARM_NEON_API_SUPPORTED +# define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ +#endif +#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ +#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */ +#ifdef PNG_MIPS_MSA_API_SUPPORTED +# define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */ +#endif +#define PNG_IGNORE_ADLER32 8 +#ifdef PNG_POWERPC_VSX_API_SUPPORTED +# define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */ +#endif +#define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */ + +/* Return values: NOTE: there are four values and 'off' is *not* zero */ +#define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ +#define PNG_OPTION_INVALID 1 /* Option number out of range */ +#define PNG_OPTION_OFF 2 +#define PNG_OPTION_ON 3 + +PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, + int onoff)); +#endif /* SET_OPTION */ + +/******************************************************************************* + * END OF HARDWARE AND SOFTWARE OPTIONS + ******************************************************************************/ + +#ifdef PNG_APNG_SUPPORTED +PNG_EXPORT(248, png_uint_32, png_get_acTL, (png_structp png_ptr, + png_infop info_ptr, png_uint_32 *num_frames, png_uint_32 *num_plays)); + +PNG_EXPORT(249, png_uint_32, png_set_acTL, (png_structp png_ptr, + png_infop info_ptr, png_uint_32 num_frames, png_uint_32 num_plays)); + +PNG_EXPORT(250, png_uint_32, png_get_num_frames, (png_structp png_ptr, + png_infop info_ptr)); + +PNG_EXPORT(251, png_uint_32, png_get_num_plays, (png_structp png_ptr, + png_infop info_ptr)); + +PNG_EXPORT(252, png_uint_32, png_get_next_frame_fcTL, + (png_structp png_ptr, png_infop info_ptr, png_uint_32 *width, + png_uint_32 *height, png_uint_32 *x_offset, png_uint_32 *y_offset, + png_uint_16 *delay_num, png_uint_16 *delay_den, png_byte *dispose_op, + png_byte *blend_op)); + +PNG_EXPORT(253, png_uint_32, png_set_next_frame_fcTL, + (png_structp png_ptr, png_infop info_ptr, png_uint_32 width, + png_uint_32 height, png_uint_32 x_offset, png_uint_32 y_offset, + png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, + png_byte blend_op)); + +PNG_EXPORT(254, png_uint_32, png_get_next_frame_width, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(255, png_uint_32, png_get_next_frame_height, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(256, png_uint_32, png_get_next_frame_x_offset, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(257, png_uint_32, png_get_next_frame_y_offset, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(258, png_uint_16, png_get_next_frame_delay_num, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(259, png_uint_16, png_get_next_frame_delay_den, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(260, png_byte, png_get_next_frame_dispose_op, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(261, png_byte, png_get_next_frame_blend_op, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(262, png_byte, png_get_first_frame_is_hidden, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(263, png_uint_32, png_set_first_frame_is_hidden, + (png_structp png_ptr, png_infop info_ptr, png_byte is_hidden)); + +#ifdef PNG_READ_APNG_SUPPORTED +PNG_EXPORT(264, void, png_read_frame_head, (png_structp png_ptr, + png_infop info_ptr)); +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +PNG_EXPORT(265, void, png_set_progressive_frame_fn, (png_structp png_ptr, + png_progressive_frame_ptr frame_info_fn, + png_progressive_frame_ptr frame_end_fn)); +#endif /* PROGRESSIVE_READ */ +#endif /* READ_APNG */ + +#ifdef PNG_WRITE_APNG_SUPPORTED +PNG_EXPORT(266, void, png_write_frame_head, (png_structp png_ptr, + png_infop info_ptr, png_bytepp row_pointers, + png_uint_32 width, png_uint_32 height, + png_uint_32 x_offset, png_uint_32 y_offset, + png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, + png_byte blend_op)); + +PNG_EXPORT(267, void, png_write_frame_tail, (png_structp png_ptr, + png_infop info_ptr)); +#endif /* WRITE_APNG */ +#endif /* APNG */ + +/* Maintainer: Put new public prototypes here ^, in libpng.3, in project + * defs, and in scripts/symbols.def. + */ + +/* The last ordinal number (this is the *last* one already used; the next + * one to use is one more than this.) + */ +#ifdef PNG_EXPORT_LAST_ORDINAL +#ifdef PNG_APNG_SUPPORTED + PNG_EXPORT_LAST_ORDINAL(269); +#else + PNG_EXPORT_LAST_ORDINAL(249); +#endif /* APNG */ +#endif + +#ifdef __cplusplus +} +#endif + +#endif /* PNG_VERSION_INFO_ONLY */ +/* Do not put anything past this line */ +#endif /* PNG_H */ diff --git a/media/libpng/pngconf.h b/media/libpng/pngconf.h new file mode 100644 index 0000000000..927a769dbe --- /dev/null +++ b/media/libpng/pngconf.h @@ -0,0 +1,623 @@ + +/* pngconf.h - machine-configurable file for libpng + * + * libpng version 1.6.37 + * + * Copyright (c) 2018-2019 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * Any machine specific code is near the front of this file, so if you + * are configuring libpng for a machine, you may want to read the section + * starting here down to where it starts to typedef png_color, png_text, + * and png_info. + */ + +#ifndef PNGCONF_H +#define PNGCONF_H + +#ifndef PNG_BUILDING_SYMBOL_TABLE /* else includes may cause problems */ + +/* From libpng 1.6.0 libpng requires an ANSI X3.159-1989 ("ISOC90") compliant C + * compiler for correct compilation. The following header files are required by + * the standard. If your compiler doesn't provide these header files, or they + * do not match the standard, you will need to provide/improve them. + */ +#include <limits.h> +#include <stddef.h> + +/* Library header files. These header files are all defined by ISOC90; libpng + * expects conformant implementations, however, an ISOC90 conformant system need + * not provide these header files if the functionality cannot be implemented. + * In this case it will be necessary to disable the relevant parts of libpng in + * the build of pnglibconf.h. + * + * Prior to 1.6.0 string.h was included here; the API changes in 1.6.0 to not + * include this unnecessary header file. + */ + +#ifdef PNG_STDIO_SUPPORTED + /* Required for the definition of FILE: */ +# include <stdio.h> +#endif + +#ifdef PNG_SETJMP_SUPPORTED + /* Required for the definition of jmp_buf and the declaration of longjmp: */ +# include <setjmp.h> +#endif + +#ifdef PNG_CONVERT_tIME_SUPPORTED + /* Required for struct tm: */ +# include <time.h> +#endif + +#endif /* PNG_BUILDING_SYMBOL_TABLE */ + +/* Prior to 1.6.0, it was possible to turn off 'const' in declarations, + * using PNG_NO_CONST. This is no longer supported. + */ +#define PNG_CONST const /* backward compatibility only */ + +/* This controls optimization of the reading of 16-bit and 32-bit + * values from PNG files. It can be set on a per-app-file basis: it + * just changes whether a macro is used when the function is called. + * The library builder sets the default; if read functions are not + * built into the library the macro implementation is forced on. + */ +#ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED +# define PNG_USE_READ_MACROS +#endif +#if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS) +# if PNG_DEFAULT_READ_MACROS +# define PNG_USE_READ_MACROS +# endif +#endif + +/* COMPILER SPECIFIC OPTIONS. + * + * These options are provided so that a variety of difficult compilers + * can be used. Some are fixed at build time (e.g. PNG_API_RULE + * below) but still have compiler specific implementations, others + * may be changed on a per-file basis when compiling against libpng. + */ + +/* The PNGARG macro was used in versions of libpng prior to 1.6.0 to protect + * against legacy (pre ISOC90) compilers that did not understand function + * prototypes. It is not required for modern C compilers. + */ +#ifndef PNGARG +# define PNGARG(arglist) arglist +#endif + +/* Function calling conventions. + * ============================= + * Normally it is not necessary to specify to the compiler how to call + * a function - it just does it - however on x86 systems derived from + * Microsoft and Borland C compilers ('IBM PC', 'DOS', 'Windows' systems + * and some others) there are multiple ways to call a function and the + * default can be changed on the compiler command line. For this reason + * libpng specifies the calling convention of every exported function and + * every function called via a user supplied function pointer. This is + * done in this file by defining the following macros: + * + * PNGAPI Calling convention for exported functions. + * PNGCBAPI Calling convention for user provided (callback) functions. + * PNGCAPI Calling convention used by the ANSI-C library (required + * for longjmp callbacks and sometimes used internally to + * specify the calling convention for zlib). + * + * These macros should never be overridden. If it is necessary to + * change calling convention in a private build this can be done + * by setting PNG_API_RULE (which defaults to 0) to one of the values + * below to select the correct 'API' variants. + * + * PNG_API_RULE=0 Use PNGCAPI - the 'C' calling convention - throughout. + * This is correct in every known environment. + * PNG_API_RULE=1 Use the operating system convention for PNGAPI and + * the 'C' calling convention (from PNGCAPI) for + * callbacks (PNGCBAPI). This is no longer required + * in any known environment - if it has to be used + * please post an explanation of the problem to the + * libpng mailing list. + * + * These cases only differ if the operating system does not use the C + * calling convention, at present this just means the above cases + * (x86 DOS/Windows systems) and, even then, this does not apply to + * Cygwin running on those systems. + * + * Note that the value must be defined in pnglibconf.h so that what + * the application uses to call the library matches the conventions + * set when building the library. + */ + +/* Symbol export + * ============= + * When building a shared library it is almost always necessary to tell + * the compiler which symbols to export. The png.h macro 'PNG_EXPORT' + * is used to mark the symbols. On some systems these symbols can be + * extracted at link time and need no special processing by the compiler, + * on other systems the symbols are flagged by the compiler and just + * the declaration requires a special tag applied (unfortunately) in a + * compiler dependent way. Some systems can do either. + * + * A small number of older systems also require a symbol from a DLL to + * be flagged to the program that calls it. This is a problem because + * we do not know in the header file included by application code that + * the symbol will come from a shared library, as opposed to a statically + * linked one. For this reason the application must tell us by setting + * the magic flag PNG_USE_DLL to turn on the special processing before + * it includes png.h. + * + * Four additional macros are used to make this happen: + * + * PNG_IMPEXP The magic (if any) to cause a symbol to be exported from + * the build or imported if PNG_USE_DLL is set - compiler + * and system specific. + * + * PNG_EXPORT_TYPE(type) A macro that pre or appends PNG_IMPEXP to + * 'type', compiler specific. + * + * PNG_DLL_EXPORT Set to the magic to use during a libpng build to + * make a symbol exported from the DLL. Not used in the + * public header files; see pngpriv.h for how it is used + * in the libpng build. + * + * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come + * from a DLL - used to define PNG_IMPEXP when + * PNG_USE_DLL is set. + */ + +/* System specific discovery. + * ========================== + * This code is used at build time to find PNG_IMPEXP, the API settings + * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL + * import processing is possible. On Windows systems it also sets + * compiler-specific macros to the values required to change the calling + * conventions of the various functions. + */ +#if defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\ + defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__) + /* Windows system (DOS doesn't support DLLs). Includes builds under Cygwin or + * MinGW on any architecture currently supported by Windows. Also includes + * Watcom builds but these need special treatment because they are not + * compatible with GCC or Visual C because of different calling conventions. + */ +# if PNG_API_RULE == 2 + /* If this line results in an error, either because __watcall is not + * understood or because of a redefine just below you cannot use *this* + * build of the library with the compiler you are using. *This* build was + * build using Watcom and applications must also be built using Watcom! + */ +# define PNGCAPI __watcall +# endif + +# if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800)) +# define PNGCAPI __cdecl +# if PNG_API_RULE == 1 + /* If this line results in an error __stdcall is not understood and + * PNG_API_RULE should not have been set to '1'. + */ +# define PNGAPI __stdcall +# endif +# else + /* An older compiler, or one not detected (erroneously) above, + * if necessary override on the command line to get the correct + * variants for the compiler. + */ +# ifndef PNGCAPI +# define PNGCAPI _cdecl +# endif +# if PNG_API_RULE == 1 && !defined(PNGAPI) +# define PNGAPI _stdcall +# endif +# endif /* compiler/api */ + + /* NOTE: PNGCBAPI always defaults to PNGCAPI. */ + +# if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD) +# error "PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed" +# endif + +# if (defined(_MSC_VER) && _MSC_VER < 800) ||\ + (defined(__BORLANDC__) && __BORLANDC__ < 0x500) + /* older Borland and MSC + * compilers used '__export' and required this to be after + * the type. + */ +# ifndef PNG_EXPORT_TYPE +# define PNG_EXPORT_TYPE(type) type PNG_IMPEXP +# endif +# define PNG_DLL_EXPORT __export +# else /* newer compiler */ +# define PNG_DLL_EXPORT __declspec(dllexport) +# ifndef PNG_DLL_IMPORT +# define PNG_DLL_IMPORT __declspec(dllimport) +# endif +# endif /* compiler */ + +#else /* !Windows */ +# if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__) +# define PNGAPI _System +# else /* !Windows/x86 && !OS/2 */ + /* Use the defaults, or define PNG*API on the command line (but + * this will have to be done for every compile!) + */ +# endif /* other system, !OS/2 */ +#endif /* !Windows/x86 */ + +/* Now do all the defaulting . */ +#ifndef PNGCAPI +# define PNGCAPI +#endif +#ifndef PNGCBAPI +# define PNGCBAPI PNGCAPI +#endif +#ifndef PNGAPI +# define PNGAPI PNGCAPI +#endif + +/* PNG_IMPEXP may be set on the compilation system command line or (if not set) + * then in an internal header file when building the library, otherwise (when + * using the library) it is set here. + */ +#ifndef PNG_IMPEXP +# if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT) + /* This forces use of a DLL, disallowing static linking */ +# define PNG_IMPEXP PNG_DLL_IMPORT +# endif + +# ifndef PNG_IMPEXP +# define PNG_IMPEXP +# endif +#endif + +/* In 1.5.2 the definition of PNG_FUNCTION has been changed to always treat + * 'attributes' as a storage class - the attributes go at the start of the + * function definition, and attributes are always appended regardless of the + * compiler. This considerably simplifies these macros but may cause problems + * if any compilers both need function attributes and fail to handle them as + * a storage class (this is unlikely.) + */ +#ifndef PNG_FUNCTION +# define PNG_FUNCTION(type, name, args, attributes) attributes type name args +#endif + +#ifndef PNG_EXPORT_TYPE +# define PNG_EXPORT_TYPE(type) PNG_IMPEXP type +#endif + + /* The ordinal value is only relevant when preprocessing png.h for symbol + * table entries, so we discard it here. See the .dfn files in the + * scripts directory. + */ + +#ifndef PNG_EXPORTA +# define PNG_EXPORTA(ordinal, type, name, args, attributes) \ + PNG_FUNCTION(PNG_EXPORT_TYPE(type), (PNGAPI name), PNGARG(args), \ + PNG_LINKAGE_API attributes) +#endif + +/* ANSI-C (C90) does not permit a macro to be invoked with an empty argument, + * so make something non-empty to satisfy the requirement: + */ +#define PNG_EMPTY /*empty list*/ + +#define PNG_EXPORT(ordinal, type, name, args) \ + PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY) + +/* Use PNG_REMOVED to comment out a removed interface. */ +#ifndef PNG_REMOVED +# define PNG_REMOVED(ordinal, type, name, args, attributes) +#endif + +#ifndef PNG_CALLBACK +# define PNG_CALLBACK(type, name, args) type (PNGCBAPI name) PNGARG(args) +#endif + +/* Support for compiler specific function attributes. These are used + * so that where compiler support is available incorrect use of API + * functions in png.h will generate compiler warnings. + * + * Added at libpng-1.2.41. + */ + +#ifndef PNG_NO_PEDANTIC_WARNINGS +# ifndef PNG_PEDANTIC_WARNINGS_SUPPORTED +# define PNG_PEDANTIC_WARNINGS_SUPPORTED +# endif +#endif + +#ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED + /* Support for compiler specific function attributes. These are used + * so that where compiler support is available, incorrect use of API + * functions in png.h will generate compiler warnings. Added at libpng + * version 1.2.41. Disabling these removes the warnings but may also produce + * less efficient code. + */ +# if defined(__clang__) && defined(__has_attribute) + /* Clang defines both __clang__ and __GNUC__. Check __clang__ first. */ +# if !defined(PNG_USE_RESULT) && __has_attribute(__warn_unused_result__) +# define PNG_USE_RESULT __attribute__((__warn_unused_result__)) +# endif +# if !defined(PNG_NORETURN) && __has_attribute(__noreturn__) +# define PNG_NORETURN __attribute__((__noreturn__)) +# endif +# if !defined(PNG_ALLOCATED) && __has_attribute(__malloc__) +# define PNG_ALLOCATED __attribute__((__malloc__)) +# endif +# if !defined(PNG_DEPRECATED) && __has_attribute(__deprecated__) +# define PNG_DEPRECATED __attribute__((__deprecated__)) +# endif +# if !defined(PNG_PRIVATE) +# ifdef __has_extension +# if __has_extension(attribute_unavailable_with_message) +# define PNG_PRIVATE __attribute__((__unavailable__(\ + "This function is not exported by libpng."))) +# endif +# endif +# endif +# ifndef PNG_RESTRICT +# define PNG_RESTRICT __restrict +# endif + +# elif defined(__GNUC__) +# ifndef PNG_USE_RESULT +# define PNG_USE_RESULT __attribute__((__warn_unused_result__)) +# endif +# ifndef PNG_NORETURN +# define PNG_NORETURN __attribute__((__noreturn__)) +# endif +# if __GNUC__ >= 3 +# ifndef PNG_ALLOCATED +# define PNG_ALLOCATED __attribute__((__malloc__)) +# endif +# ifndef PNG_DEPRECATED +# define PNG_DEPRECATED __attribute__((__deprecated__)) +# endif +# ifndef PNG_PRIVATE +# if 0 /* Doesn't work so we use deprecated instead*/ +# define PNG_PRIVATE \ + __attribute__((warning("This function is not exported by libpng."))) +# else +# define PNG_PRIVATE \ + __attribute__((__deprecated__)) +# endif +# endif +# if ((__GNUC__ > 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1)) +# ifndef PNG_RESTRICT +# define PNG_RESTRICT __restrict +# endif +# endif /* __GNUC__.__GNUC_MINOR__ > 3.0 */ +# endif /* __GNUC__ >= 3 */ + +# elif defined(_MSC_VER) && (_MSC_VER >= 1300) +# ifndef PNG_USE_RESULT +# define PNG_USE_RESULT /* not supported */ +# endif +# ifndef PNG_NORETURN +# define PNG_NORETURN __declspec(noreturn) +# endif +# ifndef PNG_ALLOCATED +# if (_MSC_VER >= 1400) +# define PNG_ALLOCATED __declspec(restrict) +# endif +# endif +# ifndef PNG_DEPRECATED +# define PNG_DEPRECATED __declspec(deprecated) +# endif +# ifndef PNG_PRIVATE +# define PNG_PRIVATE __declspec(deprecated) +# endif +# ifndef PNG_RESTRICT +# if (_MSC_VER >= 1400) +# define PNG_RESTRICT __restrict +# endif +# endif + +# elif defined(__WATCOMC__) +# ifndef PNG_RESTRICT +# define PNG_RESTRICT __restrict +# endif +# endif +#endif /* PNG_PEDANTIC_WARNINGS */ + +#ifndef PNG_DEPRECATED +# define PNG_DEPRECATED /* Use of this function is deprecated */ +#endif +#ifndef PNG_USE_RESULT +# define PNG_USE_RESULT /* The result of this function must be checked */ +#endif +#ifndef PNG_NORETURN +# define PNG_NORETURN /* This function does not return */ +#endif +#ifndef PNG_ALLOCATED +# define PNG_ALLOCATED /* The result of the function is new memory */ +#endif +#ifndef PNG_PRIVATE +# define PNG_PRIVATE /* This is a private libpng function */ +#endif +#ifndef PNG_RESTRICT +# define PNG_RESTRICT /* The C99 "restrict" feature */ +#endif + +#ifndef PNG_FP_EXPORT /* A floating point API. */ +# ifdef PNG_FLOATING_POINT_SUPPORTED +# define PNG_FP_EXPORT(ordinal, type, name, args)\ + PNG_EXPORT(ordinal, type, name, args); +# else /* No floating point APIs */ +# define PNG_FP_EXPORT(ordinal, type, name, args) +# endif +#endif +#ifndef PNG_FIXED_EXPORT /* A fixed point API. */ +# ifdef PNG_FIXED_POINT_SUPPORTED +# define PNG_FIXED_EXPORT(ordinal, type, name, args)\ + PNG_EXPORT(ordinal, type, name, args); +# else /* No fixed point APIs */ +# define PNG_FIXED_EXPORT(ordinal, type, name, args) +# endif +#endif + +#ifndef PNG_BUILDING_SYMBOL_TABLE +/* Some typedefs to get us started. These should be safe on most of the common + * platforms. + * + * png_uint_32 and png_int_32 may, currently, be larger than required to hold a + * 32-bit value however this is not normally advisable. + * + * png_uint_16 and png_int_16 should always be two bytes in size - this is + * verified at library build time. + * + * png_byte must always be one byte in size. + * + * The checks below use constants from limits.h, as defined by the ISOC90 + * standard. + */ +#if CHAR_BIT == 8 && UCHAR_MAX == 255 + typedef unsigned char png_byte; +#else +# error "libpng requires 8-bit bytes" +#endif + +#if INT_MIN == -32768 && INT_MAX == 32767 + typedef int png_int_16; +#elif SHRT_MIN == -32768 && SHRT_MAX == 32767 + typedef short png_int_16; +#else +# error "libpng requires a signed 16-bit type" +#endif + +#if UINT_MAX == 65535 + typedef unsigned int png_uint_16; +#elif USHRT_MAX == 65535 + typedef unsigned short png_uint_16; +#else +# error "libpng requires an unsigned 16-bit type" +#endif + +#if INT_MIN < -2147483646 && INT_MAX > 2147483646 + typedef int png_int_32; +#elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646 + typedef long int png_int_32; +#else +# error "libpng requires a signed 32-bit (or more) type" +#endif + +#if UINT_MAX > 4294967294U + typedef unsigned int png_uint_32; +#elif ULONG_MAX > 4294967294U + typedef unsigned long int png_uint_32; +#else +# error "libpng requires an unsigned 32-bit (or more) type" +#endif + +/* Prior to 1.6.0, it was possible to disable the use of size_t and ptrdiff_t. + * From 1.6.0 onwards, an ISO C90 compiler, as well as a standard-compliant + * behavior of sizeof and ptrdiff_t are required. + * The legacy typedefs are provided here for backwards compatibility. + */ +typedef size_t png_size_t; +typedef ptrdiff_t png_ptrdiff_t; + +/* libpng needs to know the maximum value of 'size_t' and this controls the + * definition of png_alloc_size_t, below. This maximum value of size_t limits + * but does not control the maximum allocations the library makes - there is + * direct application control of this through png_set_user_limits(). + */ +#ifndef PNG_SMALL_SIZE_T + /* Compiler specific tests for systems where size_t is known to be less than + * 32 bits (some of these systems may no longer work because of the lack of + * 'far' support; see above.) + */ +# if (defined(__TURBOC__) && !defined(__FLAT__)) ||\ + (defined(_MSC_VER) && defined(MAXSEG_64K)) +# define PNG_SMALL_SIZE_T +# endif +#endif + +/* png_alloc_size_t is guaranteed to be no smaller than size_t, and no smaller + * than png_uint_32. Casts from size_t or png_uint_32 to png_alloc_size_t are + * not necessary; in fact, it is recommended not to use them at all, so that + * the compiler can complain when something turns out to be problematic. + * + * Casts in the other direction (from png_alloc_size_t to size_t or + * png_uint_32) should be explicitly applied; however, we do not expect to + * encounter practical situations that require such conversions. + * + * PNG_SMALL_SIZE_T must be defined if the maximum value of size_t is less than + * 4294967295 - i.e. less than the maximum value of png_uint_32. + */ +#ifdef PNG_SMALL_SIZE_T + typedef png_uint_32 png_alloc_size_t; +#else + typedef size_t png_alloc_size_t; +#endif + +/* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler + * implementations of Intel CPU specific support of user-mode segmented address + * spaces, where 16-bit pointers address more than 65536 bytes of memory using + * separate 'segment' registers. The implementation requires two different + * types of pointer (only one of which includes the segment value.) + * + * If required this support is available in version 1.2 of libpng and may be + * available in versions through 1.5, although the correctness of the code has + * not been verified recently. + */ + +/* Typedef for floating-point numbers that are converted to fixed-point with a + * multiple of 100,000, e.g., gamma + */ +typedef png_int_32 png_fixed_point; + +/* Add typedefs for pointers */ +typedef void * png_voidp; +typedef const void * png_const_voidp; +typedef png_byte * png_bytep; +typedef const png_byte * png_const_bytep; +typedef png_uint_32 * png_uint_32p; +typedef const png_uint_32 * png_const_uint_32p; +typedef png_int_32 * png_int_32p; +typedef const png_int_32 * png_const_int_32p; +typedef png_uint_16 * png_uint_16p; +typedef const png_uint_16 * png_const_uint_16p; +typedef png_int_16 * png_int_16p; +typedef const png_int_16 * png_const_int_16p; +typedef char * png_charp; +typedef const char * png_const_charp; +typedef png_fixed_point * png_fixed_point_p; +typedef const png_fixed_point * png_const_fixed_point_p; +typedef size_t * png_size_tp; +typedef const size_t * png_const_size_tp; + +#ifdef PNG_STDIO_SUPPORTED +typedef FILE * png_FILE_p; +#endif + +#ifdef PNG_FLOATING_POINT_SUPPORTED +typedef double * png_doublep; +typedef const double * png_const_doublep; +#endif + +/* Pointers to pointers; i.e. arrays */ +typedef png_byte * * png_bytepp; +typedef png_uint_32 * * png_uint_32pp; +typedef png_int_32 * * png_int_32pp; +typedef png_uint_16 * * png_uint_16pp; +typedef png_int_16 * * png_int_16pp; +typedef const char * * png_const_charpp; +typedef char * * png_charpp; +typedef png_fixed_point * * png_fixed_point_pp; +#ifdef PNG_FLOATING_POINT_SUPPORTED +typedef double * * png_doublepp; +#endif + +/* Pointers to pointers to pointers; i.e., pointer to array */ +typedef char * * * png_charppp; + +#endif /* PNG_BUILDING_SYMBOL_TABLE */ + +#endif /* PNGCONF_H */ diff --git a/media/libpng/pngdebug.h b/media/libpng/pngdebug.h new file mode 100644 index 0000000000..00d5a4569e --- /dev/null +++ b/media/libpng/pngdebug.h @@ -0,0 +1,153 @@ + +/* pngdebug.h - Debugging macros for libpng, also used in pngtest.c + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* Define PNG_DEBUG at compile time for debugging information. Higher + * numbers for PNG_DEBUG mean more debugging information. This has + * only been added since version 0.95 so it is not implemented throughout + * libpng yet, but more support will be added as needed. + * + * png_debug[1-2]?(level, message ,arg{0-2}) + * Expands to a statement (either a simple expression or a compound + * do..while(0) statement) that outputs a message with parameter + * substitution if PNG_DEBUG is defined to 2 or more. If PNG_DEBUG + * is undefined, 0 or 1 every png_debug expands to a simple expression + * (actually ((void)0)). + * + * level: level of detail of message, starting at 0. A level 'n' + * message is preceded by 'n' 3-space indentations (not implemented + * on Microsoft compilers unless PNG_DEBUG_FILE is also + * defined, to allow debug DLL compilation with no standard IO). + * message: a printf(3) style text string. A trailing '\n' is added + * to the message. + * arg: 0 to 2 arguments for printf(3) style substitution in message. + */ +#ifndef PNGDEBUG_H +#define PNGDEBUG_H +/* These settings control the formatting of messages in png.c and pngerror.c */ +/* Moved to pngdebug.h at 1.5.0 */ +# ifndef PNG_LITERAL_SHARP +# define PNG_LITERAL_SHARP 0x23 +# endif +# ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET +# define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b +# endif +# ifndef PNG_LITERAL_RIGHT_SQUARE_BRACKET +# define PNG_LITERAL_RIGHT_SQUARE_BRACKET 0x5d +# endif +# ifndef PNG_STRING_NEWLINE +# define PNG_STRING_NEWLINE "\n" +# endif + +#ifdef PNG_DEBUG +# if (PNG_DEBUG > 0) +# if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER) +# include <crtdbg.h> +# if (PNG_DEBUG > 1) +# ifndef _DEBUG +# define _DEBUG +# endif +# ifndef png_debug +# define png_debug(l,m) _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE) +# endif +# ifndef png_debug1 +# define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1) +# endif +# ifndef png_debug2 +# define png_debug2(l,m,p1,p2) \ + _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2) +# endif +# endif +# else /* PNG_DEBUG_FILE || !_MSC_VER */ +# ifndef PNG_STDIO_SUPPORTED +# include <stdio.h> /* not included yet */ +# endif +# ifndef PNG_DEBUG_FILE +# define PNG_DEBUG_FILE stderr +# endif /* PNG_DEBUG_FILE */ + +# if (PNG_DEBUG > 1) +# ifdef __STDC__ +# ifndef png_debug +# define png_debug(l,m) \ + do { \ + int num_tabs=l; \ + fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \ + (num_tabs==2 ? " " : (num_tabs>2 ? " " : "")))); \ + } while (0) +# endif +# ifndef png_debug1 +# define png_debug1(l,m,p1) \ + do { \ + int num_tabs=l; \ + fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \ + (num_tabs==2 ? " " : (num_tabs>2 ? " " : ""))),p1); \ + } while (0) +# endif +# ifndef png_debug2 +# define png_debug2(l,m,p1,p2) \ + do { \ + int num_tabs=l; \ + fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \ + (num_tabs==2 ? " " : (num_tabs>2 ? " " : ""))),p1,p2);\ + } while (0) +# endif +# else /* __STDC __ */ +# ifndef png_debug +# define png_debug(l,m) \ + do { \ + int num_tabs=l; \ + char format[256]; \ + snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \ + (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \ + m,PNG_STRING_NEWLINE); \ + fprintf(PNG_DEBUG_FILE,format); \ + } while (0) +# endif +# ifndef png_debug1 +# define png_debug1(l,m,p1) \ + do { \ + int num_tabs=l; \ + char format[256]; \ + snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \ + (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \ + m,PNG_STRING_NEWLINE); \ + fprintf(PNG_DEBUG_FILE,format,p1); \ + } while (0) +# endif +# ifndef png_debug2 +# define png_debug2(l,m,p1,p2) \ + do { \ + int num_tabs=l; \ + char format[256]; \ + snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \ + (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \ + m,PNG_STRING_NEWLINE); \ + fprintf(PNG_DEBUG_FILE,format,p1,p2); \ + } while (0) +# endif +# endif /* __STDC __ */ +# endif /* (PNG_DEBUG > 1) */ + +# endif /* _MSC_VER */ +# endif /* (PNG_DEBUG > 0) */ +#endif /* PNG_DEBUG */ +#ifndef png_debug +# define png_debug(l, m) ((void)0) +#endif +#ifndef png_debug1 +# define png_debug1(l, m, p1) ((void)0) +#endif +#ifndef png_debug2 +# define png_debug2(l, m, p1, p2) ((void)0) +#endif +#endif /* PNGDEBUG_H */ diff --git a/media/libpng/pngerror.c b/media/libpng/pngerror.c new file mode 100644 index 0000000000..ec3a709b9d --- /dev/null +++ b/media/libpng/pngerror.c @@ -0,0 +1,963 @@ + +/* pngerror.c - stub functions for i/o and memory allocation + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all error handling. Users who + * need special error handling are expected to write replacement functions + * and use png_set_error_fn() to use those functions. See the instructions + * at each function. + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr, + png_const_charp error_message)),PNG_NORETURN); + +#ifdef PNG_WARNINGS_SUPPORTED +static void /* PRIVATE */ +png_default_warning PNGARG((png_const_structrp png_ptr, + png_const_charp warning_message)); +#endif /* WARNINGS */ + +/* This function is called whenever there is a fatal error. This function + * should not be changed. If there is a need to handle errors differently, + * you should supply a replacement error function and use png_set_error_fn() + * to replace the error function at run-time. + */ +#ifdef PNG_ERROR_TEXT_SUPPORTED +PNG_FUNCTION(void,PNGAPI +png_error,(png_const_structrp png_ptr, png_const_charp error_message), + PNG_NORETURN) +{ +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + char msg[16]; + if (png_ptr != NULL) + { + if ((png_ptr->flags & + (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0) + { + if (*error_message == PNG_LITERAL_SHARP) + { + /* Strip "#nnnn " from beginning of error message. */ + int offset; + for (offset = 1; offset<15; offset++) + if (error_message[offset] == ' ') + break; + + if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0) + { + int i; + for (i = 0; i < offset - 1; i++) + msg[i] = error_message[i + 1]; + msg[i - 1] = '\0'; + error_message = msg; + } + + else + error_message += offset; + } + + else + { + if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0) + { + msg[0] = '0'; + msg[1] = '\0'; + error_message = msg; + } + } + } + } +#endif + if (png_ptr != NULL && png_ptr->error_fn != NULL) + (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), + error_message); + + /* If the custom handler doesn't exist, or if it returns, + use the default handler, which will not return. */ + png_default_error(png_ptr, error_message); +} +#else +PNG_FUNCTION(void,PNGAPI +png_err,(png_const_structrp png_ptr),PNG_NORETURN) +{ + /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed + * erroneously as '\0', instead of the empty string "". This was + * apparently an error, introduced in libpng-1.2.20, and png_default_error + * will crash in this case. + */ + if (png_ptr != NULL && png_ptr->error_fn != NULL) + (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), ""); + + /* If the custom handler doesn't exist, or if it returns, + use the default handler, which will not return. */ + png_default_error(png_ptr, ""); +} +#endif /* ERROR_TEXT */ + +/* Utility to safely appends strings to a buffer. This never errors out so + * error checking is not required in the caller. + */ +size_t +png_safecat(png_charp buffer, size_t bufsize, size_t pos, + png_const_charp string) +{ + if (buffer != NULL && pos < bufsize) + { + if (string != NULL) + while (*string != '\0' && pos < bufsize-1) + buffer[pos++] = *string++; + + buffer[pos] = '\0'; + } + + return pos; +} + +#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED) +/* Utility to dump an unsigned value into a buffer, given a start pointer and + * and end pointer (which should point just *beyond* the end of the buffer!) + * Returns the pointer to the start of the formatted string. + */ +png_charp +png_format_number(png_const_charp start, png_charp end, int format, + png_alloc_size_t number) +{ + int count = 0; /* number of digits output */ + int mincount = 1; /* minimum number required */ + int output = 0; /* digit output (for the fixed point format) */ + + *--end = '\0'; + + /* This is written so that the loop always runs at least once, even with + * number zero. + */ + while (end > start && (number != 0 || count < mincount)) + { + + static const char digits[] = "0123456789ABCDEF"; + + switch (format) + { + case PNG_NUMBER_FORMAT_fixed: + /* Needs five digits (the fraction) */ + mincount = 5; + if (output != 0 || number % 10 != 0) + { + *--end = digits[number % 10]; + output = 1; + } + number /= 10; + break; + + case PNG_NUMBER_FORMAT_02u: + /* Expects at least 2 digits. */ + mincount = 2; + /* FALLTHROUGH */ + + case PNG_NUMBER_FORMAT_u: + *--end = digits[number % 10]; + number /= 10; + break; + + case PNG_NUMBER_FORMAT_02x: + /* This format expects at least two digits */ + mincount = 2; + /* FALLTHROUGH */ + + case PNG_NUMBER_FORMAT_x: + *--end = digits[number & 0xf]; + number >>= 4; + break; + + default: /* an error */ + number = 0; + break; + } + + /* Keep track of the number of digits added */ + ++count; + + /* Float a fixed number here: */ + if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start)) + { + /* End of the fraction, but maybe nothing was output? In that case + * drop the decimal point. If the number is a true zero handle that + * here. + */ + if (output != 0) + *--end = '.'; + else if (number == 0) /* and !output */ + *--end = '0'; + } + } + + return end; +} +#endif + +#ifdef PNG_WARNINGS_SUPPORTED +/* This function is called whenever there is a non-fatal error. This function + * should not be changed. If there is a need to handle warnings differently, + * you should supply a replacement warning function and use + * png_set_error_fn() to replace the warning function at run-time. + */ +void PNGAPI +png_warning(png_const_structrp png_ptr, png_const_charp warning_message) +{ + int offset = 0; + if (png_ptr != NULL) + { +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + if ((png_ptr->flags & + (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0) +#endif + { + if (*warning_message == PNG_LITERAL_SHARP) + { + for (offset = 1; offset < 15; offset++) + if (warning_message[offset] == ' ') + break; + } + } + } + if (png_ptr != NULL && png_ptr->warning_fn != NULL) + (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr), + warning_message + offset); + else + png_default_warning(png_ptr, warning_message + offset); +} + +/* These functions support 'formatted' warning messages with up to + * PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter + * is introduced by @<number>, where 'number' starts at 1. This follows the + * standard established by X/Open for internationalizable error messages. + */ +void +png_warning_parameter(png_warning_parameters p, int number, + png_const_charp string) +{ + if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT) + (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string); +} + +void +png_warning_parameter_unsigned(png_warning_parameters p, int number, int format, + png_alloc_size_t value) +{ + char buffer[PNG_NUMBER_BUFFER_SIZE]; + png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value)); +} + +void +png_warning_parameter_signed(png_warning_parameters p, int number, int format, + png_int_32 value) +{ + png_alloc_size_t u; + png_charp str; + char buffer[PNG_NUMBER_BUFFER_SIZE]; + + /* Avoid overflow by doing the negate in a png_alloc_size_t: */ + u = (png_alloc_size_t)value; + if (value < 0) + u = ~u + 1; + + str = PNG_FORMAT_NUMBER(buffer, format, u); + + if (value < 0 && str > buffer) + *--str = '-'; + + png_warning_parameter(p, number, str); +} + +void +png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p, + png_const_charp message) +{ + /* The internal buffer is just 192 bytes - enough for all our messages, + * overflow doesn't happen because this code checks! If someone figures + * out how to send us a message longer than 192 bytes, all that will + * happen is that the message will be truncated appropriately. + */ + size_t i = 0; /* Index in the msg[] buffer: */ + char msg[192]; + + /* Each iteration through the following loop writes at most one character + * to msg[i++] then returns here to validate that there is still space for + * the trailing '\0'. It may (in the case of a parameter) read more than + * one character from message[]; it must check for '\0' and continue to the + * test if it finds the end of string. + */ + while (i<(sizeof msg)-1 && *message != '\0') + { + /* '@' at end of string is now just printed (previously it was skipped); + * it is an error in the calling code to terminate the string with @. + */ + if (p != NULL && *message == '@' && message[1] != '\0') + { + int parameter_char = *++message; /* Consume the '@' */ + static const char valid_parameters[] = "123456789"; + int parameter = 0; + + /* Search for the parameter digit, the index in the string is the + * parameter to use. + */ + while (valid_parameters[parameter] != parameter_char && + valid_parameters[parameter] != '\0') + ++parameter; + + /* If the parameter digit is out of range it will just get printed. */ + if (parameter < PNG_WARNING_PARAMETER_COUNT) + { + /* Append this parameter */ + png_const_charp parm = p[parameter]; + png_const_charp pend = p[parameter] + (sizeof p[parameter]); + + /* No need to copy the trailing '\0' here, but there is no guarantee + * that parm[] has been initialized, so there is no guarantee of a + * trailing '\0': + */ + while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend) + msg[i++] = *parm++; + + /* Consume the parameter digit too: */ + ++message; + continue; + } + + /* else not a parameter and there is a character after the @ sign; just + * copy that. This is known not to be '\0' because of the test above. + */ + } + + /* At this point *message can't be '\0', even in the bad parameter case + * above where there is a lone '@' at the end of the message string. + */ + msg[i++] = *message++; + } + + /* i is always less than (sizeof msg), so: */ + msg[i] = '\0'; + + /* And this is the formatted message. It may be larger than + * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these + * are not (currently) formatted. + */ + png_warning(png_ptr, msg); +} +#endif /* WARNINGS */ + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +void PNGAPI +png_benign_error(png_const_structrp png_ptr, png_const_charp error_message) +{ + if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0) + { +# ifdef PNG_READ_SUPPORTED + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && + png_ptr->chunk_name != 0) + png_chunk_warning(png_ptr, error_message); + else +# endif + png_warning(png_ptr, error_message); + } + + else + { +# ifdef PNG_READ_SUPPORTED + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && + png_ptr->chunk_name != 0) + png_chunk_error(png_ptr, error_message); + else +# endif + png_error(png_ptr, error_message); + } + +# ifndef PNG_ERROR_TEXT_SUPPORTED + PNG_UNUSED(error_message) +# endif +} + +void /* PRIVATE */ +png_app_warning(png_const_structrp png_ptr, png_const_charp error_message) +{ + if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0) + png_warning(png_ptr, error_message); + else + png_error(png_ptr, error_message); + +# ifndef PNG_ERROR_TEXT_SUPPORTED + PNG_UNUSED(error_message) +# endif +} + +void /* PRIVATE */ +png_app_error(png_const_structrp png_ptr, png_const_charp error_message) +{ + if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0) + png_warning(png_ptr, error_message); + else + png_error(png_ptr, error_message); + +# ifndef PNG_ERROR_TEXT_SUPPORTED + PNG_UNUSED(error_message) +# endif +} +#endif /* BENIGN_ERRORS */ + +#define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */ +#if defined(PNG_WARNINGS_SUPPORTED) || \ + (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)) +/* These utilities are used internally to build an error message that relates + * to the current chunk. The chunk name comes from png_ptr->chunk_name, + * which is used to prefix the message. The message is limited in length + * to 63 bytes. The name characters are output as hex digits wrapped in [] + * if the character is invalid. + */ +#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) +static const char png_digit[16] = { + '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', + 'A', 'B', 'C', 'D', 'E', 'F' +}; + +static void /* PRIVATE */ +png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp + error_message) +{ + png_uint_32 chunk_name = png_ptr->chunk_name; + int iout = 0, ishift = 24; + + while (ishift >= 0) + { + int c = (int)(chunk_name >> ishift) & 0xff; + + ishift -= 8; + if (isnonalpha(c) != 0) + { + buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET; + buffer[iout++] = png_digit[(c & 0xf0) >> 4]; + buffer[iout++] = png_digit[c & 0x0f]; + buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET; + } + + else + { + buffer[iout++] = (char)c; + } + } + + if (error_message == NULL) + buffer[iout] = '\0'; + + else + { + int iin = 0; + + buffer[iout++] = ':'; + buffer[iout++] = ' '; + + while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0') + buffer[iout++] = error_message[iin++]; + + /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */ + buffer[iout] = '\0'; + } +} +#endif /* WARNINGS || ERROR_TEXT */ + +#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED) +PNG_FUNCTION(void,PNGAPI +png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message), + PNG_NORETURN) +{ + char msg[18+PNG_MAX_ERROR_TEXT]; + if (png_ptr == NULL) + png_error(png_ptr, error_message); + + else + { + png_format_buffer(png_ptr, msg, error_message); + png_error(png_ptr, msg); + } +} +#endif /* READ && ERROR_TEXT */ + +#ifdef PNG_WARNINGS_SUPPORTED +void PNGAPI +png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message) +{ + char msg[18+PNG_MAX_ERROR_TEXT]; + if (png_ptr == NULL) + png_warning(png_ptr, warning_message); + + else + { + png_format_buffer(png_ptr, msg, warning_message); + png_warning(png_ptr, msg); + } +} +#endif /* WARNINGS */ + +#ifdef PNG_READ_SUPPORTED +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +void PNGAPI +png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp + error_message) +{ + if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0) + png_chunk_warning(png_ptr, error_message); + + else + png_chunk_error(png_ptr, error_message); + +# ifndef PNG_ERROR_TEXT_SUPPORTED + PNG_UNUSED(error_message) +# endif +} +#endif +#endif /* READ */ + +void /* PRIVATE */ +png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error) +{ +# ifndef PNG_WARNINGS_SUPPORTED + PNG_UNUSED(message) +# endif + + /* This is always supported, but for just read or just write it + * unconditionally does the right thing. + */ +# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED) + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) +# endif + +# ifdef PNG_READ_SUPPORTED + { + if (error < PNG_CHUNK_ERROR) + png_chunk_warning(png_ptr, message); + + else + png_chunk_benign_error(png_ptr, message); + } +# endif + +# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED) + else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0) +# endif + +# ifdef PNG_WRITE_SUPPORTED + { + if (error < PNG_CHUNK_WRITE_ERROR) + png_app_warning(png_ptr, message); + + else + png_app_error(png_ptr, message); + } +# endif +} + +#ifdef PNG_ERROR_TEXT_SUPPORTED +#ifdef PNG_FLOATING_POINT_SUPPORTED +PNG_FUNCTION(void, +png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN) +{ +# define fixed_message "fixed point overflow in " +# define fixed_message_ln ((sizeof fixed_message)-1) + unsigned int iin; + char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT]; + memcpy(msg, fixed_message, fixed_message_ln); + iin = 0; + if (name != NULL) + while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0) + { + msg[fixed_message_ln + iin] = name[iin]; + ++iin; + } + msg[fixed_message_ln + iin] = 0; + png_error(png_ptr, msg); +} +#endif +#endif + +#ifdef PNG_SETJMP_SUPPORTED +/* This API only exists if ANSI-C style error handling is used, + * otherwise it is necessary for png_default_error to be overridden. + */ +jmp_buf* PNGAPI +png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn, + size_t jmp_buf_size) +{ + /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value + * and it must not change after that. Libpng doesn't care how big the + * buffer is, just that it doesn't change. + * + * If the buffer size is no *larger* than the size of jmp_buf when libpng is + * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0 + * semantics that this call will not fail. If the size is larger, however, + * the buffer is allocated and this may fail, causing the function to return + * NULL. + */ + if (png_ptr == NULL) + return NULL; + + if (png_ptr->jmp_buf_ptr == NULL) + { + png_ptr->jmp_buf_size = 0; /* not allocated */ + + if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local)) + png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; + + else + { + png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *, + png_malloc_warn(png_ptr, jmp_buf_size)); + + if (png_ptr->jmp_buf_ptr == NULL) + return NULL; /* new NULL return on OOM */ + + png_ptr->jmp_buf_size = jmp_buf_size; + } + } + + else /* Already allocated: check the size */ + { + size_t size = png_ptr->jmp_buf_size; + + if (size == 0) + { + size = (sizeof png_ptr->jmp_buf_local); + if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local) + { + /* This is an internal error in libpng: somehow we have been left + * with a stack allocated jmp_buf when the application regained + * control. It's always possible to fix this up, but for the moment + * this is a png_error because that makes it easy to detect. + */ + png_error(png_ptr, "Libpng jmp_buf still allocated"); + /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */ + } + } + + if (size != jmp_buf_size) + { + png_warning(png_ptr, "Application jmp_buf size changed"); + return NULL; /* caller will probably crash: no choice here */ + } + } + + /* Finally fill in the function, now we have a satisfactory buffer. It is + * valid to change the function on every call. + */ + png_ptr->longjmp_fn = longjmp_fn; + return png_ptr->jmp_buf_ptr; +} + +void /* PRIVATE */ +png_free_jmpbuf(png_structrp png_ptr) +{ + if (png_ptr != NULL) + { + jmp_buf *jb = png_ptr->jmp_buf_ptr; + + /* A size of 0 is used to indicate a local, stack, allocation of the + * pointer; used here and in png.c + */ + if (jb != NULL && png_ptr->jmp_buf_size > 0) + { + + /* This stuff is so that a failure to free the error control structure + * does not leave libpng in a state with no valid error handling: the + * free always succeeds, if there is an error it gets ignored. + */ + if (jb != &png_ptr->jmp_buf_local) + { + /* Make an internal, libpng, jmp_buf to return here */ + jmp_buf free_jmp_buf; + + if (!setjmp(free_jmp_buf)) + { + png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */ + png_ptr->jmp_buf_size = 0; /* stack allocation */ + png_ptr->longjmp_fn = longjmp; + png_free(png_ptr, jb); /* Return to setjmp on error */ + } + } + } + + /* *Always* cancel everything out: */ + png_ptr->jmp_buf_size = 0; + png_ptr->jmp_buf_ptr = NULL; + png_ptr->longjmp_fn = 0; + } +} +#endif + +/* This is the default error handling function. Note that replacements for + * this function MUST NOT RETURN, or the program will likely crash. This + * function is used by default, or if the program supplies NULL for the + * error function pointer in png_set_error_fn(). + */ +static PNG_FUNCTION(void /* PRIVATE */, +png_default_error,(png_const_structrp png_ptr, png_const_charp error_message), + PNG_NORETURN) +{ +#ifdef PNG_CONSOLE_IO_SUPPORTED +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + /* Check on NULL only added in 1.5.4 */ + if (error_message != NULL && *error_message == PNG_LITERAL_SHARP) + { + /* Strip "#nnnn " from beginning of error message. */ + int offset; + char error_number[16]; + for (offset = 0; offset<15; offset++) + { + error_number[offset] = error_message[offset + 1]; + if (error_message[offset] == ' ') + break; + } + + if ((offset > 1) && (offset < 15)) + { + error_number[offset - 1] = '\0'; + fprintf(stderr, "libpng error no. %s: %s", + error_number, error_message + offset + 1); + fprintf(stderr, PNG_STRING_NEWLINE); + } + + else + { + fprintf(stderr, "libpng error: %s, offset=%d", + error_message, offset); + fprintf(stderr, PNG_STRING_NEWLINE); + } + } + else +#endif + { + fprintf(stderr, "libpng error: %s", error_message ? error_message : + "undefined"); + fprintf(stderr, PNG_STRING_NEWLINE); + } +#else + PNG_UNUSED(error_message) /* Make compiler happy */ +#endif + png_longjmp(png_ptr, 1); +} + +PNG_FUNCTION(void,PNGAPI +png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN) +{ +#ifdef PNG_SETJMP_SUPPORTED + if (png_ptr != NULL && png_ptr->longjmp_fn != NULL && + png_ptr->jmp_buf_ptr != NULL) + png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val); +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(val) +#endif + + /* If control reaches this point, png_longjmp() must not return. The only + * choice is to terminate the whole process (or maybe the thread); to do + * this the ANSI-C abort() function is used unless a different method is + * implemented by overriding the default configuration setting for + * PNG_ABORT(). + */ + PNG_ABORT(); +} + +#ifdef PNG_WARNINGS_SUPPORTED +/* This function is called when there is a warning, but the library thinks + * it can continue anyway. Replacement functions don't have to do anything + * here if you don't want them to. In the default configuration, png_ptr is + * not used, but it is passed in case it may be useful. + */ +static void /* PRIVATE */ +png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message) +{ +#ifdef PNG_CONSOLE_IO_SUPPORTED +# ifdef PNG_ERROR_NUMBERS_SUPPORTED + if (*warning_message == PNG_LITERAL_SHARP) + { + int offset; + char warning_number[16]; + for (offset = 0; offset < 15; offset++) + { + warning_number[offset] = warning_message[offset + 1]; + if (warning_message[offset] == ' ') + break; + } + + if ((offset > 1) && (offset < 15)) + { + warning_number[offset + 1] = '\0'; + fprintf(stderr, "libpng warning no. %s: %s", + warning_number, warning_message + offset); + fprintf(stderr, PNG_STRING_NEWLINE); + } + + else + { + fprintf(stderr, "libpng warning: %s", + warning_message); + fprintf(stderr, PNG_STRING_NEWLINE); + } + } + else +# endif + + { + fprintf(stderr, "libpng warning: %s", warning_message); + fprintf(stderr, PNG_STRING_NEWLINE); + } +#else + PNG_UNUSED(warning_message) /* Make compiler happy */ +#endif + PNG_UNUSED(png_ptr) /* Make compiler happy */ +} +#endif /* WARNINGS */ + +/* This function is called when the application wants to use another method + * of handling errors and warnings. Note that the error function MUST NOT + * return to the calling routine or serious problems will occur. The return + * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1) + */ +void PNGAPI +png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warning_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->error_ptr = error_ptr; + png_ptr->error_fn = error_fn; +#ifdef PNG_WARNINGS_SUPPORTED + png_ptr->warning_fn = warning_fn; +#else + PNG_UNUSED(warning_fn) +#endif +} + + +/* This function returns a pointer to the error_ptr associated with the user + * functions. The application should free any memory associated with this + * pointer before png_write_destroy and png_read_destroy are called. + */ +png_voidp PNGAPI +png_get_error_ptr(png_const_structrp png_ptr) +{ + if (png_ptr == NULL) + return NULL; + + return ((png_voidp)png_ptr->error_ptr); +} + + +#ifdef PNG_ERROR_NUMBERS_SUPPORTED +void PNGAPI +png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode) +{ + if (png_ptr != NULL) + { + png_ptr->flags &= + ((~(PNG_FLAG_STRIP_ERROR_NUMBERS | + PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode); + } +} +#endif + +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) + /* Currently the above both depend on SETJMP_SUPPORTED, however it would be + * possible to implement without setjmp support just so long as there is some + * way to handle the error return here: + */ +PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI +png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message), + PNG_NORETURN) +{ + png_const_structrp png_ptr = png_nonconst_ptr; + png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr); + + /* An error is always logged here, overwriting anything (typically a warning) + * that is already there: + */ + if (image != NULL) + { + png_safecat(image->message, (sizeof image->message), 0, error_message); + image->warning_or_error |= PNG_IMAGE_ERROR; + + /* Retrieve the jmp_buf from within the png_control, making this work for + * C++ compilation too is pretty tricky: C++ wants a pointer to the first + * element of a jmp_buf, but C doesn't tell us the type of that. + */ + if (image->opaque != NULL && image->opaque->error_buf != NULL) + longjmp(png_control_jmp_buf(image->opaque), 1); + + /* Missing longjmp buffer, the following is to help debugging: */ + { + size_t pos = png_safecat(image->message, (sizeof image->message), 0, + "bad longjmp: "); + png_safecat(image->message, (sizeof image->message), pos, + error_message); + } + } + + /* Here on an internal programming error. */ + abort(); +} + +#ifdef PNG_WARNINGS_SUPPORTED +void /* PRIVATE */ PNGCBAPI +png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message) +{ + png_const_structrp png_ptr = png_nonconst_ptr; + png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr); + + /* A warning is only logged if there is no prior warning or error. */ + if (image->warning_or_error == 0) + { + png_safecat(image->message, (sizeof image->message), 0, warning_message); + image->warning_or_error |= PNG_IMAGE_WARNING; + } +} +#endif + +int /* PRIVATE */ +png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg) +{ + volatile png_imagep image = image_in; + volatile int result; + volatile png_voidp saved_error_buf; + jmp_buf safe_jmpbuf; + + /* Safely execute function(arg) with png_error returning to this function. */ + saved_error_buf = image->opaque->error_buf; + result = setjmp(safe_jmpbuf) == 0; + + if (result != 0) + { + + image->opaque->error_buf = safe_jmpbuf; + result = function(arg); + } + + image->opaque->error_buf = saved_error_buf; + + /* And do the cleanup prior to any failure return. */ + if (result == 0) + png_image_free(image); + + return result; +} +#endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */ +#endif /* READ || WRITE */ diff --git a/media/libpng/pngget.c b/media/libpng/pngget.c new file mode 100644 index 0000000000..2638cfbe9f --- /dev/null +++ b/media/libpng/pngget.c @@ -0,0 +1,1411 @@ + +/* pngget.c - retrieval of values from info struct + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +png_uint_32 PNGAPI +png_get_valid(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_uint_32 flag) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->valid & flag); + + return(0); +} + +size_t PNGAPI +png_get_rowbytes(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->rowbytes); + + return(0); +} + +#ifdef PNG_INFO_IMAGE_SUPPORTED +png_bytepp PNGAPI +png_get_rows(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->row_pointers); + + return(0); +} +#endif + +#ifdef PNG_EASY_ACCESS_SUPPORTED +/* Easy access to info, added in libpng-0.99 */ +png_uint_32 PNGAPI +png_get_image_width(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->width; + + return (0); +} + +png_uint_32 PNGAPI +png_get_image_height(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->height; + + return (0); +} + +png_byte PNGAPI +png_get_bit_depth(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->bit_depth; + + return (0); +} + +png_byte PNGAPI +png_get_color_type(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->color_type; + + return (0); +} + +png_byte PNGAPI +png_get_filter_type(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->filter_type; + + return (0); +} + +png_byte PNGAPI +png_get_interlace_type(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->interlace_type; + + return (0); +} + +png_byte PNGAPI +png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->compression_type; + + return (0); +} + +png_uint_32 PNGAPI +png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp + info_ptr) +{ +#ifdef PNG_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + png_debug1(1, "in %s retrieval function", + "png_get_x_pixels_per_meter"); + + if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER) + return (info_ptr->x_pixels_per_unit); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +png_uint_32 PNGAPI +png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp + info_ptr) +{ +#ifdef PNG_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + png_debug1(1, "in %s retrieval function", + "png_get_y_pixels_per_meter"); + + if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER) + return (info_ptr->y_pixels_per_unit); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +png_uint_32 PNGAPI +png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ +#ifdef PNG_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter"); + + if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER && + info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit) + return (info_ptr->x_pixels_per_unit); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +#ifdef PNG_FLOATING_POINT_SUPPORTED +float PNGAPI +png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp + info_ptr) +{ +#ifdef PNG_READ_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio"); + + if (info_ptr->x_pixels_per_unit != 0) + return ((float)((float)info_ptr->y_pixels_per_unit + /(float)info_ptr->x_pixels_per_unit)); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return ((float)0.0); +} +#endif + +#ifdef PNG_FIXED_POINT_SUPPORTED +png_fixed_point PNGAPI +png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr, + png_const_inforp info_ptr) +{ +#ifdef PNG_READ_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0 && + info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0 && + info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX && + info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX) + { + png_fixed_point res; + + png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio_fixed"); + + /* The following casts work because a PNG 4 byte integer only has a valid + * range of 0..2^31-1; otherwise the cast might overflow. + */ + if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1, + (png_int_32)info_ptr->x_pixels_per_unit) != 0) + return res; + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return 0; +} +#endif + +png_int_32 PNGAPI +png_get_x_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ +#ifdef PNG_oFFs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_oFFs) != 0) + { + png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns"); + + if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER) + return (info_ptr->x_offset); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +png_int_32 PNGAPI +png_get_y_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ +#ifdef PNG_oFFs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_oFFs) != 0) + { + png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns"); + + if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER) + return (info_ptr->y_offset); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +png_int_32 PNGAPI +png_get_x_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ +#ifdef PNG_oFFs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_oFFs) != 0) + { + png_debug1(1, "in %s retrieval function", "png_get_x_offset_pixels"); + + if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL) + return (info_ptr->x_offset); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +png_int_32 PNGAPI +png_get_y_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ +#ifdef PNG_oFFs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_oFFs) != 0) + { + png_debug1(1, "in %s retrieval function", "png_get_y_offset_pixels"); + + if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL) + return (info_ptr->y_offset); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +#ifdef PNG_INCH_CONVERSIONS_SUPPORTED +static png_uint_32 +ppi_from_ppm(png_uint_32 ppm) +{ +#if 0 + /* The conversion is *(2.54/100), in binary (32 digits): + * .00000110100000001001110101001001 + */ + png_uint_32 t1001, t1101; + ppm >>= 1; /* .1 */ + t1001 = ppm + (ppm >> 3); /* .1001 */ + t1101 = t1001 + (ppm >> 1); /* .1101 */ + ppm >>= 20; /* .000000000000000000001 */ + t1101 += t1101 >> 15; /* .1101000000000001101 */ + t1001 >>= 11; /* .000000000001001 */ + t1001 += t1001 >> 12; /* .000000000001001000000001001 */ + ppm += t1001; /* .000000000001001000001001001 */ + ppm += t1101; /* .110100000001001110101001001 */ + return (ppm + 16) >> 5;/* .00000110100000001001110101001001 */ +#else + /* The argument is a PNG unsigned integer, so it is not permitted + * to be bigger than 2^31. + */ + png_fixed_point result; + if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127, + 5000) != 0) + return (png_uint_32)result; + + /* Overflow. */ + return 0; +#endif +} + +png_uint_32 PNGAPI +png_get_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + return ppi_from_ppm(png_get_pixels_per_meter(png_ptr, info_ptr)); +} + +png_uint_32 PNGAPI +png_get_x_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr)); +} + +png_uint_32 PNGAPI +png_get_y_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + return ppi_from_ppm(png_get_y_pixels_per_meter(png_ptr, info_ptr)); +} + +#ifdef PNG_FIXED_POINT_SUPPORTED +static png_fixed_point +png_fixed_inches_from_microns(png_const_structrp png_ptr, png_int_32 microns) +{ + /* Convert from meters * 1,000,000 to inches * 100,000, meters to + * inches is simply *(100/2.54), so we want *(10/2.54) == 500/127. + * Notice that this can overflow - a warning is output and 0 is + * returned. + */ + return png_muldiv_warn(png_ptr, microns, 500, 127); +} + +png_fixed_point PNGAPI +png_get_x_offset_inches_fixed(png_const_structrp png_ptr, + png_const_inforp info_ptr) +{ + return png_fixed_inches_from_microns(png_ptr, + png_get_x_offset_microns(png_ptr, info_ptr)); +} +#endif + +#ifdef PNG_FIXED_POINT_SUPPORTED +png_fixed_point PNGAPI +png_get_y_offset_inches_fixed(png_const_structrp png_ptr, + png_const_inforp info_ptr) +{ + return png_fixed_inches_from_microns(png_ptr, + png_get_y_offset_microns(png_ptr, info_ptr)); +} +#endif + +#ifdef PNG_FLOATING_POINT_SUPPORTED +float PNGAPI +png_get_x_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + /* To avoid the overflow do the conversion directly in floating + * point. + */ + return (float)(png_get_x_offset_microns(png_ptr, info_ptr) * .00003937); +} +#endif + +#ifdef PNG_FLOATING_POINT_SUPPORTED +float PNGAPI +png_get_y_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + /* To avoid the overflow do the conversion directly in floating + * point. + */ + return (float)(png_get_y_offset_microns(png_ptr, info_ptr) * .00003937); +} +#endif + +#ifdef PNG_pHYs_SUPPORTED +png_uint_32 PNGAPI +png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type) +{ + png_uint_32 retval = 0; + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + png_debug1(1, "in %s retrieval function", "pHYs"); + + if (res_x != NULL) + { + *res_x = info_ptr->x_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + + if (res_y != NULL) + { + *res_y = info_ptr->y_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + + if (unit_type != NULL) + { + *unit_type = (int)info_ptr->phys_unit_type; + retval |= PNG_INFO_pHYs; + + if (*unit_type == 1) + { + if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50); + if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50); + } + } + } + + return (retval); +} +#endif /* pHYs */ +#endif /* INCH_CONVERSIONS */ + +/* png_get_channels really belongs in here, too, but it's been around longer */ + +#endif /* EASY_ACCESS */ + + +png_byte PNGAPI +png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->channels); + + return (0); +} + +#ifdef PNG_READ_SUPPORTED +png_const_bytep PNGAPI +png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->signature); + + return (NULL); +} +#endif + +#ifdef PNG_bKGD_SUPPORTED +png_uint_32 PNGAPI +png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr, + png_color_16p *background) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_bKGD) != 0 && + background != NULL) + { + png_debug1(1, "in %s retrieval function", "bKGD"); + + *background = &(info_ptr->background); + return (PNG_INFO_bKGD); + } + + return (0); +} +#endif + +#ifdef PNG_cHRM_SUPPORTED +/* The XYZ APIs were added in 1.5.5 to take advantage of the code added at the + * same time to correct the rgb grayscale coefficient defaults obtained from the + * cHRM chunk in 1.5.4 + */ +# ifdef PNG_FLOATING_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr, + double *white_x, double *white_y, double *red_x, double *red_y, + double *green_x, double *green_y, double *blue_x, double *blue_y) +{ + /* Quiet API change: this code used to only return the end points if a cHRM + * chunk was present, but the end points can also come from iCCP or sRGB + * chunks, so in 1.6.0 the png_get_ APIs return the end points regardless and + * the png_set_ APIs merely check that set end points are mutually + * consistent. + */ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + { + png_debug1(1, "in %s retrieval function", "cHRM"); + + if (white_x != NULL) + *white_x = png_float(png_ptr, + info_ptr->colorspace.end_points_xy.whitex, "cHRM white X"); + if (white_y != NULL) + *white_y = png_float(png_ptr, + info_ptr->colorspace.end_points_xy.whitey, "cHRM white Y"); + if (red_x != NULL) + *red_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redx, + "cHRM red X"); + if (red_y != NULL) + *red_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redy, + "cHRM red Y"); + if (green_x != NULL) + *green_x = png_float(png_ptr, + info_ptr->colorspace.end_points_xy.greenx, "cHRM green X"); + if (green_y != NULL) + *green_y = png_float(png_ptr, + info_ptr->colorspace.end_points_xy.greeny, "cHRM green Y"); + if (blue_x != NULL) + *blue_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluex, + "cHRM blue X"); + if (blue_y != NULL) + *blue_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluey, + "cHRM blue Y"); + return (PNG_INFO_cHRM); + } + + return (0); +} + +png_uint_32 PNGAPI +png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr, + double *red_X, double *red_Y, double *red_Z, double *green_X, + double *green_Y, double *green_Z, double *blue_X, double *blue_Y, + double *blue_Z) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + { + png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)"); + + if (red_X != NULL) + *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X, + "cHRM red X"); + if (red_Y != NULL) + *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Y, + "cHRM red Y"); + if (red_Z != NULL) + *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z, + "cHRM red Z"); + if (green_X != NULL) + *green_X = png_float(png_ptr, + info_ptr->colorspace.end_points_XYZ.green_X, "cHRM green X"); + if (green_Y != NULL) + *green_Y = png_float(png_ptr, + info_ptr->colorspace.end_points_XYZ.green_Y, "cHRM green Y"); + if (green_Z != NULL) + *green_Z = png_float(png_ptr, + info_ptr->colorspace.end_points_XYZ.green_Z, "cHRM green Z"); + if (blue_X != NULL) + *blue_X = png_float(png_ptr, + info_ptr->colorspace.end_points_XYZ.blue_X, "cHRM blue X"); + if (blue_Y != NULL) + *blue_Y = png_float(png_ptr, + info_ptr->colorspace.end_points_XYZ.blue_Y, "cHRM blue Y"); + if (blue_Z != NULL) + *blue_Z = png_float(png_ptr, + info_ptr->colorspace.end_points_XYZ.blue_Z, "cHRM blue Z"); + return (PNG_INFO_cHRM); + } + + return (0); +} +# endif + +# ifdef PNG_FIXED_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *int_red_X, png_fixed_point *int_red_Y, + png_fixed_point *int_red_Z, png_fixed_point *int_green_X, + png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, + png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, + png_fixed_point *int_blue_Z) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + { + png_debug1(1, "in %s retrieval function", "cHRM_XYZ"); + + if (int_red_X != NULL) + *int_red_X = info_ptr->colorspace.end_points_XYZ.red_X; + if (int_red_Y != NULL) + *int_red_Y = info_ptr->colorspace.end_points_XYZ.red_Y; + if (int_red_Z != NULL) + *int_red_Z = info_ptr->colorspace.end_points_XYZ.red_Z; + if (int_green_X != NULL) + *int_green_X = info_ptr->colorspace.end_points_XYZ.green_X; + if (int_green_Y != NULL) + *int_green_Y = info_ptr->colorspace.end_points_XYZ.green_Y; + if (int_green_Z != NULL) + *int_green_Z = info_ptr->colorspace.end_points_XYZ.green_Z; + if (int_blue_X != NULL) + *int_blue_X = info_ptr->colorspace.end_points_XYZ.blue_X; + if (int_blue_Y != NULL) + *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blue_Y; + if (int_blue_Z != NULL) + *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blue_Z; + return (PNG_INFO_cHRM); + } + + return (0); +} + +png_uint_32 PNGAPI +png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x, + png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y, + png_fixed_point *blue_x, png_fixed_point *blue_y) +{ + png_debug1(1, "in %s retrieval function", "cHRM"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + { + if (white_x != NULL) + *white_x = info_ptr->colorspace.end_points_xy.whitex; + if (white_y != NULL) + *white_y = info_ptr->colorspace.end_points_xy.whitey; + if (red_x != NULL) + *red_x = info_ptr->colorspace.end_points_xy.redx; + if (red_y != NULL) + *red_y = info_ptr->colorspace.end_points_xy.redy; + if (green_x != NULL) + *green_x = info_ptr->colorspace.end_points_xy.greenx; + if (green_y != NULL) + *green_y = info_ptr->colorspace.end_points_xy.greeny; + if (blue_x != NULL) + *blue_x = info_ptr->colorspace.end_points_xy.bluex; + if (blue_y != NULL) + *blue_y = info_ptr->colorspace.end_points_xy.bluey; + return (PNG_INFO_cHRM); + } + + return (0); +} +# endif +#endif + +#ifdef PNG_gAMA_SUPPORTED +# ifdef PNG_FIXED_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *file_gamma) +{ + png_debug1(1, "in %s retrieval function", "gAMA"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 && + file_gamma != NULL) + { + *file_gamma = info_ptr->colorspace.gamma; + return (PNG_INFO_gAMA); + } + + return (0); +} +# endif + +# ifdef PNG_FLOATING_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr, + double *file_gamma) +{ + png_debug1(1, "in %s retrieval function", "gAMA(float)"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 && + file_gamma != NULL) + { + *file_gamma = png_float(png_ptr, info_ptr->colorspace.gamma, + "png_get_gAMA"); + return (PNG_INFO_gAMA); + } + + return (0); +} +# endif +#endif + +#ifdef PNG_sRGB_SUPPORTED +png_uint_32 PNGAPI +png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr, + int *file_srgb_intent) +{ + png_debug1(1, "in %s retrieval function", "sRGB"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sRGB) != 0 && file_srgb_intent != NULL) + { + *file_srgb_intent = info_ptr->colorspace.rendering_intent; + return (PNG_INFO_sRGB); + } + + return (0); +} +#endif + +#ifdef PNG_iCCP_SUPPORTED +png_uint_32 PNGAPI +png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr, + png_charpp name, int *compression_type, + png_bytepp profile, png_uint_32 *proflen) +{ + png_debug1(1, "in %s retrieval function", "iCCP"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_iCCP) != 0 && + name != NULL && profile != NULL && proflen != NULL) + { + *name = info_ptr->iccp_name; + *profile = info_ptr->iccp_profile; + *proflen = png_get_uint_32(info_ptr->iccp_profile); + /* This is somewhat irrelevant since the profile data returned has + * actually been uncompressed. + */ + if (compression_type != NULL) + *compression_type = PNG_COMPRESSION_TYPE_BASE; + return (PNG_INFO_iCCP); + } + + return (0); + +} +#endif + +#ifdef PNG_sPLT_SUPPORTED +int PNGAPI +png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr, + png_sPLT_tpp spalettes) +{ + if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL) + { + *spalettes = info_ptr->splt_palettes; + return info_ptr->splt_palettes_num; + } + + return (0); +} +#endif + +#ifdef PNG_eXIf_SUPPORTED +png_uint_32 PNGAPI +png_get_eXIf(png_const_structrp png_ptr, png_inforp info_ptr, + png_bytep *exif) +{ + png_warning(png_ptr, "png_get_eXIf does not work; use png_get_eXIf_1"); + PNG_UNUSED(info_ptr) + PNG_UNUSED(exif) + return 0; +} + +png_uint_32 PNGAPI +png_get_eXIf_1(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_uint_32 *num_exif, png_bytep *exif) +{ + png_debug1(1, "in %s retrieval function", "eXIf"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_eXIf) != 0 && exif != NULL) + { + *num_exif = info_ptr->num_exif; + *exif = info_ptr->exif; + return (PNG_INFO_eXIf); + } + + return (0); +} +#endif + +#ifdef PNG_hIST_SUPPORTED +png_uint_32 PNGAPI +png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr, + png_uint_16p *hist) +{ + png_debug1(1, "in %s retrieval function", "hIST"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_hIST) != 0 && hist != NULL) + { + *hist = info_ptr->hist; + return (PNG_INFO_hIST); + } + + return (0); +} +#endif + +png_uint_32 PNGAPI +png_get_IHDR(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_uint_32 *width, png_uint_32 *height, int *bit_depth, + int *color_type, int *interlace_type, int *compression_type, + int *filter_type) +{ + png_debug1(1, "in %s retrieval function", "IHDR"); + + if (png_ptr == NULL || info_ptr == NULL) + return (0); + + if (width != NULL) + *width = info_ptr->width; + + if (height != NULL) + *height = info_ptr->height; + + if (bit_depth != NULL) + *bit_depth = info_ptr->bit_depth; + + if (color_type != NULL) + *color_type = info_ptr->color_type; + + if (compression_type != NULL) + *compression_type = info_ptr->compression_type; + + if (filter_type != NULL) + *filter_type = info_ptr->filter_type; + + if (interlace_type != NULL) + *interlace_type = info_ptr->interlace_type; + + /* This is redundant if we can be sure that the info_ptr values were all + * assigned in png_set_IHDR(). We do the check anyhow in case an + * application has ignored our advice not to mess with the members + * of info_ptr directly. + */ + png_check_IHDR(png_ptr, info_ptr->width, info_ptr->height, + info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type, + info_ptr->compression_type, info_ptr->filter_type); + + return (1); +} + +#ifdef PNG_oFFs_SUPPORTED +png_uint_32 PNGAPI +png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type) +{ + png_debug1(1, "in %s retrieval function", "oFFs"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_oFFs) != 0 && + offset_x != NULL && offset_y != NULL && unit_type != NULL) + { + *offset_x = info_ptr->x_offset; + *offset_y = info_ptr->y_offset; + *unit_type = (int)info_ptr->offset_unit_type; + return (PNG_INFO_oFFs); + } + + return (0); +} +#endif + +#ifdef PNG_pCAL_SUPPORTED +png_uint_32 PNGAPI +png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr, + png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams, + png_charp *units, png_charpp *params) +{ + png_debug1(1, "in %s retrieval function", "pCAL"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pCAL) != 0 && + purpose != NULL && X0 != NULL && X1 != NULL && type != NULL && + nparams != NULL && units != NULL && params != NULL) + { + *purpose = info_ptr->pcal_purpose; + *X0 = info_ptr->pcal_X0; + *X1 = info_ptr->pcal_X1; + *type = (int)info_ptr->pcal_type; + *nparams = (int)info_ptr->pcal_nparams; + *units = info_ptr->pcal_units; + *params = info_ptr->pcal_params; + return (PNG_INFO_pCAL); + } + + return (0); +} +#endif + +#ifdef PNG_sCAL_SUPPORTED +# ifdef PNG_FIXED_POINT_SUPPORTED +# if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ + defined(PNG_FLOATING_POINT_SUPPORTED) +png_uint_32 PNGAPI +png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, + int *unit, png_fixed_point *width, png_fixed_point *height) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sCAL) != 0) + { + *unit = info_ptr->scal_unit; + /*TODO: make this work without FP support; the API is currently eliminated + * if neither floating point APIs nor internal floating point arithmetic + * are enabled. + */ + *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width"); + *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height), + "sCAL height"); + return (PNG_INFO_sCAL); + } + + return(0); +} +# endif /* FLOATING_ARITHMETIC */ +# endif /* FIXED_POINT */ +# ifdef PNG_FLOATING_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr, + int *unit, double *width, double *height) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sCAL) != 0) + { + *unit = info_ptr->scal_unit; + *width = atof(info_ptr->scal_s_width); + *height = atof(info_ptr->scal_s_height); + return (PNG_INFO_sCAL); + } + + return(0); +} +# endif /* FLOATING POINT */ +png_uint_32 PNGAPI +png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr, + int *unit, png_charpp width, png_charpp height) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sCAL) != 0) + { + *unit = info_ptr->scal_unit; + *width = info_ptr->scal_s_width; + *height = info_ptr->scal_s_height; + return (PNG_INFO_sCAL); + } + + return(0); +} +#endif /* sCAL */ + +#ifdef PNG_pHYs_SUPPORTED +png_uint_32 PNGAPI +png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type) +{ + png_uint_32 retval = 0; + + png_debug1(1, "in %s retrieval function", "pHYs"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + if (res_x != NULL) + { + *res_x = info_ptr->x_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + + if (res_y != NULL) + { + *res_y = info_ptr->y_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + + if (unit_type != NULL) + { + *unit_type = (int)info_ptr->phys_unit_type; + retval |= PNG_INFO_pHYs; + } + } + + return (retval); +} +#endif /* pHYs */ + +png_uint_32 PNGAPI +png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr, + png_colorp *palette, int *num_palette) +{ + png_debug1(1, "in %s retrieval function", "PLTE"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_PLTE) != 0 && palette != NULL) + { + *palette = info_ptr->palette; + *num_palette = info_ptr->num_palette; + png_debug1(3, "num_palette = %d", *num_palette); + return (PNG_INFO_PLTE); + } + + return (0); +} + +#ifdef PNG_sBIT_SUPPORTED +png_uint_32 PNGAPI +png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr, + png_color_8p *sig_bit) +{ + png_debug1(1, "in %s retrieval function", "sBIT"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sBIT) != 0 && sig_bit != NULL) + { + *sig_bit = &(info_ptr->sig_bit); + return (PNG_INFO_sBIT); + } + + return (0); +} +#endif + +#ifdef PNG_TEXT_SUPPORTED +int PNGAPI +png_get_text(png_const_structrp png_ptr, png_inforp info_ptr, + png_textp *text_ptr, int *num_text) +{ + if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0) + { + png_debug1(1, "in 0x%lx retrieval function", + (unsigned long)png_ptr->chunk_name); + + if (text_ptr != NULL) + *text_ptr = info_ptr->text; + + if (num_text != NULL) + *num_text = info_ptr->num_text; + + return info_ptr->num_text; + } + + if (num_text != NULL) + *num_text = 0; + + return(0); +} +#endif + +#ifdef PNG_tIME_SUPPORTED +png_uint_32 PNGAPI +png_get_tIME(png_const_structrp png_ptr, png_inforp info_ptr, + png_timep *mod_time) +{ + png_debug1(1, "in %s retrieval function", "tIME"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_tIME) != 0 && mod_time != NULL) + { + *mod_time = &(info_ptr->mod_time); + return (PNG_INFO_tIME); + } + + return (0); +} +#endif + +#ifdef PNG_tRNS_SUPPORTED +png_uint_32 PNGAPI +png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr, + png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color) +{ + png_uint_32 retval = 0; + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_tRNS) != 0) + { + png_debug1(1, "in %s retrieval function", "tRNS"); + + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (trans_alpha != NULL) + { + *trans_alpha = info_ptr->trans_alpha; + retval |= PNG_INFO_tRNS; + } + + if (trans_color != NULL) + *trans_color = &(info_ptr->trans_color); + } + + else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */ + { + if (trans_color != NULL) + { + *trans_color = &(info_ptr->trans_color); + retval |= PNG_INFO_tRNS; + } + + if (trans_alpha != NULL) + *trans_alpha = NULL; + } + + if (num_trans != NULL) + { + *num_trans = info_ptr->num_trans; + retval |= PNG_INFO_tRNS; + } + } + + return (retval); +} +#endif + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +int PNGAPI +png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr, + png_unknown_chunkpp unknowns) +{ + if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL) + { + *unknowns = info_ptr->unknown_chunks; + return info_ptr->unknown_chunks_num; + } + + return (0); +} +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +png_byte PNGAPI +png_get_rgb_to_gray_status (png_const_structrp png_ptr) +{ + return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0); +} +#endif + +#ifdef PNG_USER_CHUNKS_SUPPORTED +png_voidp PNGAPI +png_get_user_chunk_ptr(png_const_structrp png_ptr) +{ + return (png_ptr ? png_ptr->user_chunk_ptr : NULL); +} +#endif + +size_t PNGAPI +png_get_compression_buffer_size(png_const_structrp png_ptr) +{ + if (png_ptr == NULL) + return 0; + +#ifdef PNG_WRITE_SUPPORTED + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) +#endif + { +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED + return png_ptr->IDAT_read_size; +#else + return PNG_IDAT_READ_SIZE; +#endif + } + +#ifdef PNG_WRITE_SUPPORTED + else + return png_ptr->zbuffer_size; +#endif +} + +#ifdef PNG_SET_USER_LIMITS_SUPPORTED +/* These functions were added to libpng 1.2.6 and were enabled + * by default in libpng-1.4.0 */ +png_uint_32 PNGAPI +png_get_user_width_max (png_const_structrp png_ptr) +{ + return (png_ptr ? png_ptr->user_width_max : 0); +} + +png_uint_32 PNGAPI +png_get_user_height_max (png_const_structrp png_ptr) +{ + return (png_ptr ? png_ptr->user_height_max : 0); +} + +/* This function was added to libpng 1.4.0 */ +png_uint_32 PNGAPI +png_get_chunk_cache_max (png_const_structrp png_ptr) +{ + return (png_ptr ? png_ptr->user_chunk_cache_max : 0); +} + +/* This function was added to libpng 1.4.1 */ +png_alloc_size_t PNGAPI +png_get_chunk_malloc_max (png_const_structrp png_ptr) +{ + return (png_ptr ? png_ptr->user_chunk_malloc_max : 0); +} +#endif /* SET_USER_LIMITS */ + +/* These functions were added to libpng 1.4.0 */ +#ifdef PNG_IO_STATE_SUPPORTED +png_uint_32 PNGAPI +png_get_io_state (png_const_structrp png_ptr) +{ + return png_ptr->io_state; +} + +png_uint_32 PNGAPI +png_get_io_chunk_type (png_const_structrp png_ptr) +{ + return png_ptr->chunk_name; +} +#endif /* IO_STATE */ + +#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED +# ifdef PNG_GET_PALETTE_MAX_SUPPORTED +int PNGAPI +png_get_palette_max(png_const_structp png_ptr, png_const_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return png_ptr->num_palette_max; + + return (-1); +} +# endif +#endif + +#ifdef PNG_APNG_SUPPORTED +png_uint_32 PNGAPI +png_get_acTL(png_structp png_ptr, png_infop info_ptr, + png_uint_32 *num_frames, png_uint_32 *num_plays) +{ + png_debug1(1, "in %s retrieval function", "acTL"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_acTL) != 0 && + num_frames != NULL && num_plays != NULL) + { + *num_frames = info_ptr->num_frames; + *num_plays = info_ptr->num_plays; + return (1); + } + + return (0); +} + +png_uint_32 PNGAPI +png_get_num_frames(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_get_num_frames()"); + + if (png_ptr != NULL && info_ptr != NULL) + return (info_ptr->num_frames); + return (0); +} + +png_uint_32 PNGAPI +png_get_num_plays(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_get_num_plays()"); + + if (png_ptr != NULL && info_ptr != NULL) + return (info_ptr->num_plays); + return (0); +} + +png_uint_32 PNGAPI +png_get_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr, + png_uint_32 *width, png_uint_32 *height, + png_uint_32 *x_offset, png_uint_32 *y_offset, + png_uint_16 *delay_num, png_uint_16 *delay_den, + png_byte *dispose_op, png_byte *blend_op) +{ + png_debug1(1, "in %s retrieval function", "fcTL"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_fcTL) != 0 && + width != NULL && height != NULL && + x_offset != NULL && y_offset != NULL && + delay_num != NULL && delay_den != NULL && + dispose_op != NULL && blend_op != NULL) + { + *width = info_ptr->next_frame_width; + *height = info_ptr->next_frame_height; + *x_offset = info_ptr->next_frame_x_offset; + *y_offset = info_ptr->next_frame_y_offset; + *delay_num = info_ptr->next_frame_delay_num; + *delay_den = info_ptr->next_frame_delay_den; + *dispose_op = info_ptr->next_frame_dispose_op; + *blend_op = info_ptr->next_frame_blend_op; + return (1); + } + + return (0); +} + +png_uint_32 PNGAPI +png_get_next_frame_width(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_get_next_frame_width()"); + + if (png_ptr != NULL && info_ptr != NULL) + return (info_ptr->next_frame_width); + return (0); +} + +png_uint_32 PNGAPI +png_get_next_frame_height(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_get_next_frame_height()"); + + if (png_ptr != NULL && info_ptr != NULL) + return (info_ptr->next_frame_height); + return (0); +} + +png_uint_32 PNGAPI +png_get_next_frame_x_offset(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_get_next_frame_x_offset()"); + + if (png_ptr != NULL && info_ptr != NULL) + return (info_ptr->next_frame_x_offset); + return (0); +} + +png_uint_32 PNGAPI +png_get_next_frame_y_offset(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_get_next_frame_y_offset()"); + + if (png_ptr != NULL && info_ptr != NULL) + return (info_ptr->next_frame_y_offset); + return (0); +} + +png_uint_16 PNGAPI +png_get_next_frame_delay_num(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_get_next_frame_delay_num()"); + + if (png_ptr != NULL && info_ptr != NULL) + return (info_ptr->next_frame_delay_num); + return (0); +} + +png_uint_16 PNGAPI +png_get_next_frame_delay_den(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_get_next_frame_delay_den()"); + + if (png_ptr != NULL && info_ptr != NULL) + return (info_ptr->next_frame_delay_den); + return (0); +} + +png_byte PNGAPI +png_get_next_frame_dispose_op(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_get_next_frame_dispose_op()"); + + if (png_ptr != NULL && info_ptr != NULL) + return (info_ptr->next_frame_dispose_op); + return (0); +} + +png_byte PNGAPI +png_get_next_frame_blend_op(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_get_next_frame_blend_op()"); + + if (png_ptr != NULL && info_ptr != NULL) + return (info_ptr->next_frame_blend_op); + return (0); +} + +png_byte PNGAPI +png_get_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_first_frame_is_hidden()"); + + if (png_ptr != NULL) + return (png_byte)(png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN); + + PNG_UNUSED(info_ptr) + + return 0; +} +#endif /* APNG */ +#endif /* READ || WRITE */ diff --git a/media/libpng/pnginfo.h b/media/libpng/pnginfo.h new file mode 100644 index 0000000000..ac7b269132 --- /dev/null +++ b/media/libpng/pnginfo.h @@ -0,0 +1,280 @@ + +/* pnginfo.h - header file for PNG reference library + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2013,2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + + /* png_info is a structure that holds the information in a PNG file so + * that the application can find out the characteristics of the image. + * If you are reading the file, this structure will tell you what is + * in the PNG file. If you are writing the file, fill in the information + * you want to put into the PNG file, using png_set_*() functions, then + * call png_write_info(). + * + * The names chosen should be very close to the PNG specification, so + * consult that document for information about the meaning of each field. + * + * With libpng < 0.95, it was only possible to directly set and read the + * the values in the png_info_struct, which meant that the contents and + * order of the values had to remain fixed. With libpng 0.95 and later, + * however, there are now functions that abstract the contents of + * png_info_struct from the application, so this makes it easier to use + * libpng with dynamic libraries, and even makes it possible to use + * libraries that don't have all of the libpng ancillary chunk-handing + * functionality. In libpng-1.5.0 this was moved into a separate private + * file that is not visible to applications. + * + * The following members may have allocated storage attached that should be + * cleaned up before the structure is discarded: palette, trans, text, + * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile, + * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these + * are automatically freed when the info structure is deallocated, if they were + * allocated internally by libpng. This behavior can be changed by means + * of the png_data_freer() function. + * + * More allocation details: all the chunk-reading functions that + * change these members go through the corresponding png_set_* + * functions. A function to clear these members is available: see + * png_free_data(). The png_set_* functions do not depend on being + * able to point info structure members to any of the storage they are + * passed (they make their own copies), EXCEPT that the png_set_text + * functions use the same storage passed to them in the text_ptr or + * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns + * functions do not make their own copies. + */ +#ifndef PNGINFO_H +#define PNGINFO_H + +struct png_info_def +{ + /* The following are necessary for every PNG file */ + png_uint_32 width; /* width of image in pixels (from IHDR) */ + png_uint_32 height; /* height of image in pixels (from IHDR) */ + png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */ + size_t rowbytes; /* bytes needed to hold an untransformed row */ + png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */ + png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */ + png_uint_16 num_trans; /* number of transparent palette color (tRNS) */ + png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */ + png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */ + /* The following three should have been named *_method not *_type */ + png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */ + png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */ + png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ + + /* The following are set by png_set_IHDR, called from the application on + * write, but the are never actually used by the write code. + */ + png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */ + png_byte pixel_depth; /* number of bits per pixel */ + png_byte spare_byte; /* to align the data, and for future use */ + +#ifdef PNG_READ_SUPPORTED + /* This is never set during write */ + png_byte signature[8]; /* magic bytes read by libpng from start of file */ +#endif + + /* The rest of the data is optional. If you are reading, check the + * valid field to see if the information in these are valid. If you + * are writing, set the valid field to those chunks you want written, + * and initialize the appropriate fields below. + */ + +#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) + /* png_colorspace only contains 'flags' if neither GAMMA or COLORSPACE are + * defined. When COLORSPACE is switched on all the colorspace-defining + * chunks should be enabled, when GAMMA is switched on all the gamma-defining + * chunks should be enabled. If this is not done it becomes possible to read + * inconsistent PNG files and assign a probably incorrect interpretation to + * the information. (In other words, by carefully choosing which chunks to + * recognize the system configuration can select an interpretation for PNG + * files containing ambiguous data and this will result in inconsistent + * behavior between different libpng builds!) + */ + png_colorspace colorspace; +#endif + +#ifdef PNG_iCCP_SUPPORTED + /* iCCP chunk data. */ + png_charp iccp_name; /* profile name */ + png_bytep iccp_profile; /* International Color Consortium profile data */ + png_uint_32 iccp_proflen; /* ICC profile data length */ +#endif + +#ifdef PNG_TEXT_SUPPORTED + /* The tEXt, and zTXt chunks contain human-readable textual data in + * uncompressed, compressed, and optionally compressed forms, respectively. + * The data in "text" is an array of pointers to uncompressed, + * null-terminated C strings. Each chunk has a keyword that describes the + * textual data contained in that chunk. Keywords are not required to be + * unique, and the text string may be empty. Any number of text chunks may + * be in an image. + */ + int num_text; /* number of comments read or comments to write */ + int max_text; /* current size of text array */ + png_textp text; /* array of comments read or comments to write */ +#endif /* TEXT */ + +#ifdef PNG_tIME_SUPPORTED + /* The tIME chunk holds the last time the displayed image data was + * modified. See the png_time struct for the contents of this struct. + */ + png_time mod_time; +#endif + +#ifdef PNG_sBIT_SUPPORTED + /* The sBIT chunk specifies the number of significant high-order bits + * in the pixel data. Values are in the range [1, bit_depth], and are + * only specified for the channels in the pixel data. The contents of + * the low-order bits is not specified. Data is valid if + * (valid & PNG_INFO_sBIT) is non-zero. + */ + png_color_8 sig_bit; /* significant bits in color channels */ +#endif + +#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \ +defined(PNG_READ_BACKGROUND_SUPPORTED) + /* The tRNS chunk supplies transparency data for paletted images and + * other image types that don't need a full alpha channel. There are + * "num_trans" transparency values for a paletted image, stored in the + * same order as the palette colors, starting from index 0. Values + * for the data are in the range [0, 255], ranging from fully transparent + * to fully opaque, respectively. For non-paletted images, there is a + * single color specified that should be treated as fully transparent. + * Data is valid if (valid & PNG_INFO_tRNS) is non-zero. + */ + png_bytep trans_alpha; /* alpha values for paletted image */ + png_color_16 trans_color; /* transparent color for non-palette image */ +#endif + +#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + /* The bKGD chunk gives the suggested image background color if the + * display program does not have its own background color and the image + * is needs to composited onto a background before display. The colors + * in "background" are normally in the same color space/depth as the + * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero. + */ + png_color_16 background; +#endif + +#ifdef PNG_oFFs_SUPPORTED + /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards + * and downwards from the top-left corner of the display, page, or other + * application-specific co-ordinate space. See the PNG_OFFSET_ defines + * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero. + */ + png_int_32 x_offset; /* x offset on page */ + png_int_32 y_offset; /* y offset on page */ + png_byte offset_unit_type; /* offset units type */ +#endif + +#ifdef PNG_pHYs_SUPPORTED + /* The pHYs chunk gives the physical pixel density of the image for + * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_ + * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero. + */ + png_uint_32 x_pixels_per_unit; /* horizontal pixel density */ + png_uint_32 y_pixels_per_unit; /* vertical pixel density */ + png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */ +#endif + +#ifdef PNG_eXIf_SUPPORTED + int num_exif; /* Added at libpng-1.6.31 */ + png_bytep exif; +# ifdef PNG_READ_eXIf_SUPPORTED + png_bytep eXIf_buf; /* Added at libpng-1.6.32 */ +# endif +#endif + +#ifdef PNG_hIST_SUPPORTED + /* The hIST chunk contains the relative frequency or importance of the + * various palette entries, so that a viewer can intelligently select a + * reduced-color palette, if required. Data is an array of "num_palette" + * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST) + * is non-zero. + */ + png_uint_16p hist; +#endif + +#ifdef PNG_pCAL_SUPPORTED + /* The pCAL chunk describes a transformation between the stored pixel + * values and original physical data values used to create the image. + * The integer range [0, 2^bit_depth - 1] maps to the floating-point + * range given by [pcal_X0, pcal_X1], and are further transformed by a + * (possibly non-linear) transformation function given by "pcal_type" + * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_ + * defines below, and the PNG-Group's PNG extensions document for a + * complete description of the transformations and how they should be + * implemented, and for a description of the ASCII parameter strings. + * Data values are valid if (valid & PNG_INFO_pCAL) non-zero. + */ + png_charp pcal_purpose; /* pCAL chunk description string */ + png_int_32 pcal_X0; /* minimum value */ + png_int_32 pcal_X1; /* maximum value */ + png_charp pcal_units; /* Latin-1 string giving physical units */ + png_charpp pcal_params; /* ASCII strings containing parameter values */ + png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */ + png_byte pcal_nparams; /* number of parameters given in pcal_params */ +#endif + +/* New members added in libpng-1.0.6 */ + png_uint_32 free_me; /* flags items libpng is responsible for freeing */ + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED + /* Storage for unknown chunks that the library doesn't recognize. */ + png_unknown_chunkp unknown_chunks; + + /* The type of this field is limited by the type of + * png_struct::user_chunk_cache_max, else overflow can occur. + */ + int unknown_chunks_num; +#endif + +#ifdef PNG_sPLT_SUPPORTED + /* Data on sPLT chunks (there may be more than one). */ + png_sPLT_tp splt_palettes; + int splt_palettes_num; /* Match type returned by png_get API */ +#endif + +#ifdef PNG_sCAL_SUPPORTED + /* The sCAL chunk describes the actual physical dimensions of the + * subject matter of the graphic. The chunk contains a unit specification + * a byte value, and two ASCII strings representing floating-point + * values. The values are width and height corresponding to one pixel + * in the image. Data values are valid if (valid & PNG_INFO_sCAL) is + * non-zero. + */ + png_byte scal_unit; /* unit of physical scale */ + png_charp scal_s_width; /* string containing height */ + png_charp scal_s_height; /* string containing width */ +#endif + +#ifdef PNG_INFO_IMAGE_SUPPORTED + /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) + non-zero */ + /* Data valid if (valid & PNG_INFO_IDAT) non-zero */ + png_bytepp row_pointers; /* the image bits */ +#endif + +#ifdef PNG_APNG_SUPPORTED + png_uint_32 num_frames; /* including default image */ + png_uint_32 num_plays; + png_uint_32 next_frame_width; + png_uint_32 next_frame_height; + png_uint_32 next_frame_x_offset; + png_uint_32 next_frame_y_offset; + png_uint_16 next_frame_delay_num; + png_uint_16 next_frame_delay_den; + png_byte next_frame_dispose_op; + png_byte next_frame_blend_op; +#endif + +}; +#endif /* PNGINFO_H */ diff --git a/media/libpng/pnglibconf.h b/media/libpng/pnglibconf.h new file mode 100644 index 0000000000..618ec28c5f --- /dev/null +++ b/media/libpng/pnglibconf.h @@ -0,0 +1,705 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef PNGLCONF_H +#define PNGLCONF_H + +#define MOZ_EMBEDDED_LIBPNG + +/* Limit image dimensions (bug #251381, #591822, #967656, and #1283961) */ +#define PNG_USER_LIMITS_SUPPORTED +#ifndef MOZ_PNG_MAX_WIDTH +# define MOZ_PNG_MAX_WIDTH 0x7fffffffL /* Unlimited */ +#endif +#ifndef MOZ_PNG_MAX_HEIGHT +# define MOZ_PNG_MAX_HEIGHT 0x7fffffffL /* Unlimited */ +#endif +/* but allow nsPNGDecoder to override the limits (bug #1368407) */ +#define PNG_SET_USER_LIMITS_SUPPORTED + +#define PNG_API_RULE 0 +#define PNG_COST_SHIFT 3 +#define PNG_GAMMA_THRESHOLD_FIXED 5000 +#define PNG_IDAT_READ_SIZE PNG_ZBUF_SIZE +#define PNG_INFLATE_BUF_SIZE 1024 +#define PNG_LINKAGE_API extern +#define PNG_LINKAGE_CALLBACK extern +#define PNG_LINKAGE_DATA extern +#define PNG_LINKAGE_FUNCTION extern +#define PNG_MAX_GAMMA_8 11 +#define PNG_SET_OPTION_SUPPORTED +#define PNG_sRGB_PROFILE_CHECKS -1 +#define PNG_USER_CHUNK_CACHE_MAX 128 +#define PNG_USER_CHUNK_MALLOC_MAX 4000000L +#define PNG_USER_HEIGHT_MAX MOZ_PNG_MAX_WIDTH +#define PNG_USER_WIDTH_MAX MOZ_PNG_MAX_HEIGHT +#define PNG_WEIGHT_SHIFT 8 +#define PNG_ZBUF_SIZE 8192 +#define PNG_Z_DEFAULT_COMPRESSION (-1) +#define PNG_Z_DEFAULT_NOFILTER_STRATEGY 0 +#define PNG_Z_DEFAULT_STRATEGY 1 + +#ifdef _MSC_VER +/* The PNG_PEDANTIC_WARNINGS (attributes) fail to build with some MSC + * compilers; we'll play it safe and disable them for all MSC compilers. + */ +#define PNG_NO_PEDANTIC_WARNINGS +#endif + +#ifdef MOZ_PNG_USE_ARM_NEON +# undef PNG_ARM_NEON_OPT /* Let libpng decide */ +# define PNG_ALIGNED_MEMORY_SUPPORTED +#else +# define PNG_ARM_NEON_OPT 0 +#endif + +#ifdef MOZ_PNG_USE_MIPS_MSA +# undef PNG_MIPS_MSA_OPT +# define PNG_ALIGNED_MEMORY_SUPPORTED +#else +# define PNG_MIPS_MSA_OPT 0 +#endif + +#ifdef MOZ_PNG_USE_INTEL_SSE +# undef PNG_INTEL_SSE_OPT +# define PNG_INTEL_SSE +# define PNG_ALIGNED_MEMORY_SUPPORTED +#else +# define PNG_INTEL_SSE_OPT 0 +#endif + +#ifdef MOZ_PNG_USE_POWERPC +# undef PNG_POWERPC_VSX_OPT /* Let libpng decide */ +#else +# define PNG_POWERPC_VSX_OPT 0 /* Do not use VSX optimization */ +#endif + +#define PNG_READ_SUPPORTED +#define PNG_PROGRESSIVE_READ_SUPPORTED +#define PNG_READ_APNG_SUPPORTED +#define PNG_READ_cHRM_SUPPORTED +#define PNG_READ_gAMA_SUPPORTED +#define PNG_READ_iCCP_SUPPORTED +#define PNG_READ_sRGB_SUPPORTED +#define PNG_READ_tRNS_SUPPORTED +#define PNG_READ_16BIT_SUPPORTED +#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED +#define PNG_READ_COMPOSITE_NODIV_SUPPORTED +#define PNG_READ_COMPRESSED_TEXT_SUPPORTED +#define PNG_READ_EXPAND_SUPPORTED +#define PNG_READ_GAMMA_SUPPORTED +#define PNG_READ_GRAY_TO_RGB_SUPPORTED +#define PNG_READ_INTERLACING_SUPPORTED +#define PNG_READ_SCALE_16_TO_8_SUPPORTED +#define PNG_READ_TRANSFORMS_SUPPORTED + +/* necessary for freetype color bitmap support */ +#if defined(FT_CONFIG_OPTION_USE_PNG) +#define PNG_READ_PACK_SUPPORTED +#define PNG_READ_FILLER_SUPPORTED +#define PNG_READ_STRIP_16_TO_8_SUPPORTED +#define PNG_READ_USER_TRANSFORM_SUPPORTED +#define PNG_SEQUENTIAL_READ_SUPPORTED +#endif + +#define PNG_WRITE_SUPPORTED +#define PNG_WRITE_APNG_SUPPORTED +#define PNG_WRITE_tRNS_SUPPORTED +#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED +#define PNG_WRITE_FLUSH_SUPPORTED +#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED +#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED + +#define PNG_APNG_SUPPORTED +#define PNG_ALLOW_BENIGN_ERRORS +#define PNG_BENIGN_ERRORS_SUPPORTED +#define PNG_BENIGN_READ_ERRORS_SUPPORTED +#define PNG_cHRM_SUPPORTED +#define PNG_COLORSPACE_SUPPORTED +#define PNG_gAMA_SUPPORTED +#define PNG_GAMMA_SUPPORTED +#define PNG_iCCP_SUPPORTED +#define PNG_sRGB_SUPPORTED +#define PNG_tRNS_SUPPORTED +#define PNG_16BIT_SUPPORTED +#define PNG_FLOATING_ARITHMETIC_SUPPORTED +#define PNG_FLOATING_POINT_SUPPORTED +#define PNG_POINTER_INDEXING_SUPPORTED +#define PNG_SETJMP_SUPPORTED +#define PNG_STDIO_SUPPORTED + +#define PNG_CHECK_cHRM_SUPPORTED +#define PNG_ERROR_TEXT_SUPPORTED +#define PNG_WARNINGS_SUPPORTED + +/* Mangle names of exported libpng functions so different libpng versions + can coexist. It is recommended that if you do this, you give your + library a different name such as "mozlibpng" instead of "libpng". */ + +/* The following has been present since libpng-0.88, has never changed, and + is unaffected by conditional compilation macros. It will not be mangled + and it is the only choice for use in configure scripts for detecting the + presence of any libpng version since 0.88. + + png_get_io_ptr +*/ + +/* Mozilla: mangle it anyway. */ +#define png_get_io_ptr MOZ_PNG_get_io_ptr + +/* The following weren't present in libpng-0.88 but have never changed since + they were first introduced and are not affected by any conditional compile + choices and therefore don't need to be mangled. We'll mangle them anyway. */ +#define png_sig_cmp MOZ_PNG_sig_cmp +#define png_access_version_number MOZ_PNG_access_vn + +/* These have never changed since they were first introduced but they + make direct reference to members of png_ptr that might have been moved, + so they will be mangled. */ + +#define png_set_sig_bytes MOZ_PNG_set_sig_b +#define png_reset_zstream MOZ_PNG_reset_zs + +/* The following may have changed, or can be affected by conditional compilation + choices, and will be mangled. */ +#define png_64bit_product MOZ_PNG_64bit_product +#define png_build_gamma_table MOZ_PNG_build_gamma_tab +#define png_build_grayscale_palette MOZ_PNG_build_g_p +#define png_calculate_crc MOZ_PNG_calc_crc +#define png_calloc MOZ_PNG_calloc +#define png_check_cHRM_fixed MOZ_PNG_ck_cHRM_fixed +#define png_check_chunk_name MOZ_PNG_ck_chunk_name +#define png_check_IHDR MOZ_PNG_ck_IHDR +#define png_check_keyword MOZ_PNG_ck_keyword +#define png_combine_row MOZ_PNG_combine_row +#define png_convert_from_struct_tm MOZ_PNG_cv_from_struct_tm +#define png_convert_from_time_t MOZ_PNG_cv_from_time_t +#define png_convert_to_rfc1123 MOZ_PNG_cv_to_rfc1123 +#define png_correct_palette MOZ_PNG_correct_palette +#define png_crc_error MOZ_PNG_crc_error +#define png_crc_finish MOZ_PNG_crc_finish +#define png_crc_read MOZ_PNG_crc_read +#define png_create_info_struct MOZ_PNG_cr_info_str +#define png_create_read_struct MOZ_PNG_cr_read_str +#define png_create_read_struct_2 MOZ_PNG_cr_read_str_2 +#define png_create_struct MOZ_PNG_create_st +#define png_create_struct_2 MOZ_PNG_create_s2 +#define png_create_write_struct MOZ_PNG_cr_write_str +#define png_create_write_struct_2 MOZ_PNG_cr_write_str_2 +#define png_data_freer MOZ_PNG_data_freer +#define png_decompress_chunk MOZ_PNG_decomp_chunk +#define png_default_error MOZ_PNG_def_error +#define png_default_flush MOZ_PNG_def_flush +#define png_default_read_data MOZ_PNG_def_read_data +#define png_default_warning MOZ_PNG_def_warning +#define png_default_write_data MOZ_PNG_default_write_data +#define png_destroy_info_struct MOZ_PNG_dest_info_str +#define png_destroy_read_struct MOZ_PNG_dest_read_str +#define png_destroy_struct MOZ_PNG_dest_str +#define png_destroy_struct_2 MOZ_PNG_dest_str_2 +#define png_destroy_write_struct MOZ_PNG_dest_write_str +#define png_digit MOZ_PNG_digit +#define png_do_bgr MOZ_PNG_do_bgr +#define png_do_chop MOZ_PNG_do_chop +#define png_do_expand MOZ_PNG_do_expand +#define png_do_expand_palette MOZ_PNG_do_expand_plte +#define png_do_gamma MOZ_PNG_do_gamma +#define png_do_gray_to_rgb MOZ_PNG_do_g_to_rgb +#define png_do_invert MOZ_PNG_do_invert +#define png_do_packswap MOZ_PNG_do_packswap +#define png_do_read_filler MOZ_PNG_do_read_fill +#define png_do_read_interlace MOZ_PNG_do_read_int +#define png_do_read_intrapixel MOZ_PNG_do_read_intra +#define png_do_read_invert_alpha MOZ_PNG_do_read_inv_alph +#define png_do_read_swap_alpha MOZ_PNG_do_read_swap_alph +#define png_do_read_transformations MOZ_PNG_do_read_trans +#define png_do_rgb_to_gray MOZ_PNG_do_rgb_to_g +#define png_do_shift MOZ_PNG_do_shift +#define png_do_swap MOZ_PNG_do_swap +#define png_do_unpack MOZ_PNG_do_unpack +#define png_do_unshift MOZ_PNG_do_unshift +#define png_do_write_interlace MOZ_PNG_do_write_interlace +#define png_do_write_intrapixel MOZ_PNG_do_write_intrapixel +#define png_do_write_invert_alpha MOZ_PNG_do_write_invert_alpha +#define png_do_write_swap_alpha MOZ_PNG_do_write_swap_alpha +#define png_do_write_transformations MOZ_PNG_do_write_trans +#define png_err MOZ_PNG_err +#define png_far_to_near MOZ_PNG_far_to_near +#define png_fixed MOZ_PNG_fixed +#define png_flush MOZ_PNG_flush +#define png_format_buffer MOZ_PNG_format_buf +#define png_free MOZ_PNG_free +#define png_free_data MOZ_PNG_free_data +#define png_free_default MOZ_PNG_free_def +#define png_get_bit_depth MOZ_PNG_get_bit_depth +#define png_get_bKGD MOZ_PNG_get_bKGD +#define png_get_channels MOZ_PNG_get_channels +#define png_get_cHRM MOZ_PNG_get_cHRM +#define png_get_cHRM_fixed MOZ_PNG_get_cHRM_fixed +#define png_get_color_type MOZ_PNG_get_color_type +#define png_get_compression_buffer_size MOZ_PNG_get_comp_buf_siz +#define png_get_compression_type MOZ_PNG_get_comp_type +#define png_get_copyright MOZ_PNG_get_copyright +#define png_get_error_ptr MOZ_PNG_get_error_ptr +#define png_get_filter_type MOZ_PNG_get_filter_type +#define png_get_gAMA MOZ_PNG_get_gAMA +#define png_get_gAMA_fixed MOZ_PNG_get_gAMA_fixed +#define png_get_header_ver MOZ_PNG_get_hdr_ver +#define png_get_header_version MOZ_PNG_get_hdr_vn +#define png_get_hIST MOZ_PNG_get_hIST +#define png_get_iCCP MOZ_PNG_get_iCCP +#define png_get_IHDR MOZ_PNG_get_IHDR +#define png_get_image_height MOZ_PNG_get_image_h +#define png_get_image_width MOZ_PNG_get_image_w +#define png_get_interlace_type MOZ_PNG_get_interlace_type +#define png_get_libpng_ver MOZ_PNG_get_libpng_ver +#define png_get_mem_ptr MOZ_PNG_get_mem_ptr +#define png_get_oFFs MOZ_PNG_get_oFFs +#define png_get_pCAL MOZ_PNG_get_pCAL +#define png_get_pHYs MOZ_PNG_get_pHYs +#define png_get_pHYs_dpi MOZ_PNG_get_pHYs_dpi +#define png_get_pixel_aspect_ratio MOZ_PNG_get_pixel_aspect_ratio +#define png_get_pixels_per_inch MOZ_PNG_get_pixels_per_inch +#define png_get_pixels_per_meter MOZ_PNG_get_pixels_p_m +#define png_get_PLTE MOZ_PNG_get_PLTE +#define png_get_progressive_ptr MOZ_PNG_get_progressive_ptr +#define png_get_rgb_to_gray_status MOZ_PNG_get_rgb_to_gray_status +#define png_get_rowbytes MOZ_PNG_get_rowbytes +#define png_get_rows MOZ_PNG_get_rows +#define png_get_sBIT MOZ_PNG_get_sBIT +#define png_get_sCAL MOZ_PNG_get_sCAL +#define png_get_sCAL_s MOZ_PNG_get_sCAL_s +#define png_get_signature MOZ_PNG_get_signature +#define png_get_sPLT MOZ_PNG_get_sPLT +#define png_get_sRGB MOZ_PNG_get_sRGB +#define png_get_text MOZ_PNG_get_text +#define png_get_tIME MOZ_PNG_get_tIME +#define png_get_tRNS MOZ_PNG_get_tRNS +#define png_get_unknown_chunks MOZ_PNG_get_unk_chunks +#define png_get_user_chunk_ptr MOZ_PNG_get_user_chunk_ptr +#define png_get_user_height_max MOZ_PNG_get_user_height_max +#define png_get_user_transform_ptr MOZ_PNG_get_user_transform_ptr +#define png_get_user_width_max MOZ_PNG_get_user_width_max +#define png_get_valid MOZ_PNG_get_valid +#define png_get_x_offset_inches MOZ_PNG_get_x_offset_inches +#define png_get_x_offset_microns MOZ_PNG_get_x_offs_microns +#define png_get_x_offset_pixels MOZ_PNG_get_x_offs_pixels +#define png_get_x_pixels_per_inch MOZ_PNG_get_x_pixels_per_inch +#define png_get_x_pixels_per_meter MOZ_PNG_get_x_pix_per_meter +#define png_get_y_offset_inches MOZ_PNG_get_y_offset_inches +#define png_get_y_offset_microns MOZ_PNG_get_y_offs_microns +#define png_get_y_offset_pixels MOZ_PNG_get_y_offs_pixels +#define png_get_y_pixels_per_inch MOZ_PNG_get_y_pixels_per_inch +#define png_get_y_pixels_per_meter MOZ_PNG_get_y_pix_per_meter +#define png_handle_as_unknown MOZ_PNG_handle_as_unknown +#define png_handle_bKGD MOZ_PNG_handle_bKGD +#define png_handle_cHRM MOZ_PNG_handle_cHRM +#define png_handle_gAMA MOZ_PNG_handle_gAMA +#define png_handle_hIST MOZ_PNG_handle_hIST +#define png_handle_iCCP MOZ_PNG_handle_iCCP +#define png_handle_IEND MOZ_PNG_handle_IEND +#define png_handle_IHDR MOZ_PNG_handle_IHDR +#define png_handle_iTXt MOZ_PNG_handle_iTXt +#define png_handle_oFFs MOZ_PNG_handle_oFFs +#define png_handle_pCAL MOZ_PNG_handle_pCAL +#define png_handle_pHYs MOZ_PNG_handle_pHYs +#define png_handle_PLTE MOZ_PNG_handle_PLTE +#define png_handle_sBIT MOZ_PNG_handle_sBIT +#define png_handle_sCAL MOZ_PNG_handle_sCAL +#define png_handle_sPLT MOZ_PNG_handle_sPLT +#define png_handle_sRGB MOZ_PNG_handle_sRGB +#define png_handle_tEXt MOZ_PNG_handle_tEXt +#define png_handle_tIME MOZ_PNG_handle_tIME +#define png_handle_tRNS MOZ_PNG_handle_tRNS +#define png_handle_unknown MOZ_PNG_handle_unknown +#define png_handle_zTXt MOZ_PNG_handle_zTXt +#define png_inflate MOZ_PNG_inflate +#define png_info_destroy MOZ_PNG_info_dest +#define png_info_init_3 MOZ_PNG_info_init_3 +#define png_init_io MOZ_PNG_init_io +#define png_init_read_transformations MOZ_PNG_init_read_transf +#define png_malloc MOZ_PNG_malloc +#define png_malloc_default MOZ_PNG_malloc_default +#define png_malloc_warn MOZ_PNG_malloc_warn +#define png_permit_mng_features MOZ_PNG_permit_mng_features +#define png_process_data MOZ_PNG_process_data +#define png_process_IDAT_data MOZ_PNG_proc_IDAT_data +#define png_process_some_data MOZ_PNG_proc_some_data +#define png_progressive_combine_row MOZ_PNG_progressive_combine_row +#define png_push_check_crc MOZ_PNG_push_check_crc +#define png_push_fill_buffer MOZ_PNG_push_fill_buffer +#define png_push_handle_iTXt MOZ_PNG_push_handle_iTXt +#define png_push_handle_tEXt MOZ_PNG_push_handle_tEXt +#define png_push_handle_unknown MOZ_PNG_push_handle_unk +#define png_push_handle_zTXt MOZ_PNG_push_handle_ztXt +#define png_push_have_end MOZ_PNG_push_have_end +#define png_push_have_info MOZ_PNG_push_have_info +#define png_push_have_row MOZ_PNG_push_have_row +#define png_push_process_row MOZ_PNG_push_proc_row +#define png_push_read_chunk MOZ_PNG_push_read_chunk +#define png_push_read_end MOZ_PNG_push_read_end +#define png_push_read_IDAT MOZ_PNG_push_read_IDAT +#define png_push_read_iTXt MOZ_PNG_push_read_iTXt +#define png_push_read_sig MOZ_PNG_push_read_sig +#define png_push_read_tEXt MOZ_PNG_push_read_tEXt +#define png_push_read_zTXt MOZ_PNG_push_read_zTXt +#define png_push_restore_buffer MOZ_PNG_push_rest_buf +#define png_push_save_buffer MOZ_PNG_push_save_buf +#define png_read_chunk_header MOZ_PNG_read_chunk_header +#define png_read_data MOZ_PNG_read_data +#define png_read_destroy MOZ_PNG_read_dest +#define png_read_end MOZ_PNG_read_end +#define png_read_filter_row MOZ_PNG_read_filt_row +#define png_read_finish_row MOZ_PNG_read_finish_row +#define png_read_image MOZ_PNG_read_image +#define png_read_info MOZ_PNG_read_info +#define png_read_png MOZ_PNG_read_png +#define png_read_push_finish_row MOZ_PNG_read_push_finish_row +#define png_read_row MOZ_PNG_read_row +#define png_read_rows MOZ_PNG_read_rows +#define png_read_start_row MOZ_PNG_read_start_row +#define png_read_transform_info MOZ_PNG_read_transform_info +#define png_read_update_info MOZ_PNG_read_update_info +#define png_reset_crc MOZ_PNG_reset_crc +#define png_save_int_32 MOZ_PNG_save_int_32 +#define png_save_uint_16 MOZ_PNG_save_uint_16 +#define png_save_uint_32 MOZ_PNG_save_uint_32 +#define png_set_add_alpha MOZ_PNG_set_add_alpha +#define png_set_background MOZ_PNG_set_background +#define png_set_benign_errors MOZ_PNG_set_benign_errors +#define png_set_bgr MOZ_PNG_set_bgr +#define png_set_bKGD MOZ_PNG_set_bKGD +#define png_set_cHRM MOZ_PNG_set_cHRM +#define png_set_cHRM_fixed MOZ_PNG_set_cHRM_fixed +#define png_set_compression_buffer_size MOZ_PNG_set_comp_buf_siz +#define png_set_compression_level MOZ_PNG_set_comp_level +#define png_set_compression_mem_level MOZ_PNG_set_comp_mem_lev +#define png_set_compression_method MOZ_PNG_set_comp_method +#define png_set_compression_strategy MOZ_PNG_set_comp_strategy +#define png_set_compression_window_bits MOZ_PNG_set_comp_win_bits +#define png_set_crc_action MOZ_PNG_set_crc_action +#define png_set_error_fn MOZ_PNG_set_error_fn +#define png_set_expand MOZ_PNG_set_expand +#define png_set_expand_gray_1_2_4_to_8 MOZ_PNG_set_x_g_124_to_8 +#define png_set_filler MOZ_PNG_set_filler +#define png_set_filter MOZ_PNG_set_filter +#define png_set_filter_heuristics MOZ_PNG_set_filter_heur +#define png_set_flush MOZ_PNG_set_flush +#define png_set_gAMA MOZ_PNG_set_gAMA +#define png_set_gAMA_fixed MOZ_PNG_set_gAMA_fixed +#define png_set_gamma MOZ_PNG_set_gamma +#define png_set_gray_to_rgb MOZ_PNG_set_gray_to_rgb +#define png_set_hIST MOZ_PNG_set_hIST +#define png_set_iCCP MOZ_PNG_set_iCCP +#define png_set_IHDR MOZ_PNG_set_IHDR +#define png_set_interlace_handling MOZ_PNG_set_interlace_handling +#define png_set_invalid MOZ_PNG_set_invalid +#define png_set_invert_alpha MOZ_PNG_set_invert_alpha +#define png_set_invert_mono MOZ_PNG_set_invert_mono +#define png_set_keep_unknown_chunks MOZ_PNG_set_keep_unknown_chunks +#define png_set_mem_fn MOZ_PNG_set_mem_fn +#define png_set_oFFs MOZ_PNG_set_oFFs +#define png_set_packing MOZ_PNG_set_packing +#define png_set_packswap MOZ_PNG_set_packswap +#define png_set_palette_to_rgb MOZ_PNG_set_palette_to_rgb +#define png_set_pCAL MOZ_PNG_set_pCAL +#define png_set_pHYs MOZ_PNG_set_pHYs +#define png_set_PLTE MOZ_PNG_set_PLTE +#define png_set_progressive_read_fn MOZ_PNG_set_progressive_read_fn +#define png_set_read_fn MOZ_PNG_set_read_fn +#define png_set_read_status_fn MOZ_PNG_set_read_status_fn +#define png_set_read_user_chunk_fn MOZ_PNG_set_read_user_chunk_fn +#define png_set_read_user_transform_fn MOZ_PNG_set_read_user_trans_fn +#define png_set_rgb_to_gray MOZ_PNG_set_rgb_to_gray +#define png_set_rgb_to_gray_fixed MOZ_PNG_set_rgb_to_gray_fixed +#define png_set_rows MOZ_PNG_set_rows +#define png_set_sBIT MOZ_PNG_set_sBIT +#define png_set_sCAL MOZ_PNG_set_sCAL +#define png_set_sCAL_s MOZ_PNG_set_sCAL_s +#define png_set_shift MOZ_PNG_set_shift +#define png_set_sPLT MOZ_PNG_set_sPLT +#define png_set_sRGB MOZ_PNG_set_sRGB +#define png_set_sRGB_gAMA_and_cHRM MOZ_PNG_set_sRGB_gAMA_and_cHRM +#define png_set_strip_16 MOZ_PNG_set_strip_16 +#define png_set_strip_alpha MOZ_PNG_set_strip_alpha +#define png_set_strip_error_numbers MOZ_PNG_set_strip_err_nums +#define png_set_swap MOZ_PNG_set_swap +#define png_set_swap_alpha MOZ_PNG_set_swap_alpha +#define png_set_text MOZ_PNG_set_text +#define png_set_text_2 MOZ_PNG_set_text_2 +#define png_set_tIME MOZ_PNG_set_tIME +#define png_set_tRNS MOZ_PNG_set_tRNS +#define png_set_tRNS_to_alpha MOZ_PNG_set_tRNS_to_alpha +#define png_set_unknown_chunk_location MOZ_PNG_set_unknown_chunk_loc +#define png_set_unknown_chunks MOZ_PNG_set_unknown_chunks +#define png_set_user_limits MOZ_PNG_set_user_limits +#define png_set_user_transform_info MOZ_PNG_set_user_transform_info +#define png_set_write_fn MOZ_PNG_set_write_fn +#define png_set_write_status_fn MOZ_PNG_set_write_status_fn +#define png_set_write_user_transform_fn MOZ_PNG_set_write_user_trans_fn +#define png_start_read_image MOZ_PNG_start_read_image +#define png_text_compress MOZ_PNG_text_compress +#define png_write_bKGD MOZ_PNG_write_bKGD +#define png_write_cHRM MOZ_PNG_write_cHRM +#define png_write_cHRM_fixed MOZ_PNG_write_cHRM_fixed +#define png_write_chunk MOZ_PNG_write_chunk +#define png_write_chunk_data MOZ_PNG_write_chunk_data +#define png_write_chunk_end MOZ_PNG_write_chunk_end +#define png_write_chunk_start MOZ_PNG_write_chunk_start +#define png_write_compressed_data_out MOZ_PNG_write_compressed_data_out +#define png_write_data MOZ_PNG_write_data +#define png_write_destroy MOZ_PNG_write_destroy +#define png_write_end MOZ_PNG_write_end +#define png_write_filtered_row MOZ_PNG_write_filtered_row +#define png_write_find_filter MOZ_PNG_write_find_filter +#define png_write_finish_row MOZ_PNG_write_finish_row +#define png_write_flush MOZ_PNG_write_flush +#define png_write_gAMA MOZ_PNG_write_gAMA +#define png_write_gAMA_fixed MOZ_PNG_write_gAMA_fixed +#define png_write_hIST MOZ_PNG_write_hIST +#define png_write_iCCP MOZ_PNG_write_iCCP +#define png_write_IDAT MOZ_PNG_write_IDAT +#define png_write_IEND MOZ_PNG_write_IEND +#define png_write_IHDR MOZ_PNG_write_IHDR +#define png_write_image MOZ_PNG_write_image +#define png_write_info MOZ_PNG_write_info +#define png_write_info_before_PLTE MOZ_PNG_write_info_before_PLTE +#define png_write_iTXt MOZ_PNG_write_iTXt +#define png_write_oFFs MOZ_PNG_write_oFFs +#define png_write_pCAL MOZ_PNG_write_pCAL +#define png_write_pHYs MOZ_PNG_write_pHYs +#define png_write_PLTE MOZ_PNG_write_PLTE +#define png_write_png MOZ_PNG_write_png +#define png_write_row MOZ_PNG_write_row +#define png_write_rows MOZ_PNG_write_rows +#define png_write_sBIT MOZ_PNG_write_sBIT +#define png_write_sCAL_s MOZ_PNG_write_sCAL_s +#define png_write_sig MOZ_PNG_write_sig +#define png_write_sPLT MOZ_PNG_write_sPLT +#define png_write_sRGB MOZ_PNG_write_sRGB +#define png_write_start_row MOZ_PNG_write_trans +#define png_write_tEXt MOZ_PNG_write_tEXt +#define png_write_tIME MOZ_PNG_write_tIME +#define png_write_tRNS MOZ_PNG_write_tRNS +#define png_write_zTXt MOZ_PNG_write_zTXt +#define png_zalloc MOZ_PNG_zalloc +#define png_zfree MOZ_PNG_zfree +#define onebppswaptable MOZ_onebppswaptable +#define twobppswaptable MOZ_twobppswaptable +#define fourbppswaptable MOZ_fourbppswaptable + +/* APNG additions */ +#define png_ensure_fcTL_is_valid MOZ_APNG_ensure_fcTL_is_valid +#define png_ensure_sequence_number MOZ_APNG_ensure_seqno +#define png_get_acTL MOZ_APNG_get_acTL +#define png_get_first_frame_is_hidden MOZ_APNG_get_first_frame_is_hidden +#define png_get_next_frame_blend_op MOZ_APNG_get_next_frame_blend_op +#define png_get_next_frame_delay_den MOZ_APNG_get_next_frame_delay_den +#define png_get_next_frame_delay_num MOZ_APNG_get_next_frame_delay_num +#define png_get_next_frame_dispose_op MOZ_APNG_get_next_frame_dispose_op +#define png_get_next_frame_fcTL MOZ_APNG_get_next_frame_fcTL +#define png_get_next_frame_height MOZ_APNG_get_next_frame_height +#define png_get_next_frame_width MOZ_APNG_get_next_frame_width +#define png_get_next_frame_x_offset MOZ_APNG_get_next_frame_x_offset +#define png_get_next_frame_y_offset MOZ_APNG_get_next_frame_y_offset +#define png_get_num_frames MOZ_APNG_set_num_frames +#define png_get_num_plays MOZ_APNG_set_num_plays +#define png_handle_acTL MOZ_APNG_handle_acTL +#define png_handle_fcTL MOZ_APNG_handle_fcTL +#define png_handle_fdAT MOZ_APNG_handle_fdAT +#define png_have_info MOZ_APNG_have_info +#define png_progressive_read_reset MOZ_APNG_prog_read_reset +#define png_read_frame_head MOZ_APNG_read_frame_head +#define png_read_reinit MOZ_APNG_read_reinit +#define png_read_reset MOZ_APNG_read_reset +#define png_set_acTL MOZ_APNG_set_acTL +#define png_set_first_frame_is_hidden MOZ_APNG_set_first_frame_is_hidden +#define png_set_next_frame_fcTL MOZ_APNG_set_next_frame_fcTL +#define png_set_progressive_frame_fn MOZ_APNG_set_prog_frame_fn +#define png_write_acTL MOZ_APNG_write_acTL +#define png_write_fcTL MOZ_APNG_write_fcTL +#define png_write_fdAT MOZ_APNG_write_fdAT +#define png_write_frame_head MOZ_APNG_write_frame_head +#define png_write_frame_tail MOZ_APNG_write_frame_tail +#define png_write_reinit MOZ_APNG_write_reinit +#define png_write_reset MOZ_APNG_write_reset + +/* libpng-1.4.x additions */ +#define png_do_quantize MOZ_PNG_do_quantize +#define png_get_chunk_cache_max MOZ_PNG_get_chunk_cache_max +#define png_get_chunk_malloc_max MOZ_PNG_get_chunk_malloc_max +#define png_get_io_chunk_name MOZ_PNG_get_io_chunk_name +#define png_get_io_state MOZ_PNG_get_io_state +#define png_longjmp MOZ_PNG_longjmp +#define png_read_sig MOZ_PNG_read_sig +#define png_set_chunk_cache_max MOZ_PNG_set_chunk_cache_max +#define png_set_chunk_malloc_max MOZ_PNG_set_chunk_malloc_max +#define png_set_longjmp_fn MOZ_PNG_set_longjmp_fn +#define png_set_quantize MOZ_PNG_set_quantize + +/* libpng-1.5.x additions */ +#define png_32bit_exp MOZ_PNG_32bit_exp +#define png_8bit_l2 MOZ_PNG_8bit_l2 +#define png_ascii_from_fixed MOZ_PNG_ascii_from_fixed +#define png_ascii_from_fp MOZ_PNG_ascii_from_fp +#define png_build_16bit_table MOZ_PNG_build_16bit_table +#define png_build_16to8_table MOZ_PNG_build_16to8_table +#define png_build_8bit_table MOZ_PNG_build_8bit_table +#define png_check_fp_number MOZ_PNG_check_fp_number +#define png_check_fp_string MOZ_PNG_check_fp_string +#define png_chunk_unknown_handling MOZ_PNG_chunk_unk_handling +#define png_destroy_gamma_table MOZ_PNG_destroy_gamma_table +#define png_do_compose MOZ_PNG_do_compose +#define png_do_encode_alpha MOZ_PNG_do_encode_alpha +#define png_do_expand_16 MOZ_PNG_do_expand_16 +#define png_do_scale_16_to_8 MOZ_PNG_do_scale_16_to_8 +#define png_do_strip_channel MOZ_PNG_do_strip_channel +#define png_exp MOZ_PNG_exp +#define png_exp16bit MOZ_PNG_exp16bit +#define png_exp8bit MOZ_PNG_exp8bit +#define png_fixed_inches_from_microns MOZ_PNG_fixed_inch_from_micr +#define png_format_number MOZ_PNG_format_number +#define png_gamma_16bit_correct MOZ_PNG_gamma_16bit_correct +#define png_gamma_8bit_correct MOZ_PNG_gamma_8bit_correct +#define png_gamma_correct MOZ_PNG_gamma_correct +#define png_gamma_significant MOZ_PNG_gamma_significant +#define png_gamma_threshold MOZ_PNG_gamma_threshold +#define png_get_cHRM_XYZ MOZ_PNG_get_cHRM_XYZ +#define png_get_cHRM_XYZ_fixed MOZ_PNG_get_cHRM_XYZ_fixed +#define png_get_current_pass_number MOZ_PNG_get_cur_pass_number +#define png_get_current_row_number MOZ_PNG_get_cur_row_number +#define png_get_fixed_point MOZ_PNG_get_fixed_point +#define png_get_io_chunk_type MOZ_PNG_get_io_chunk_type +#define png_get_pixel_aspect_ratio_fixed MOZ_PNG_get_pixel_aspect_fx +#define png_get_sCAL_fixed MOZ_PNG_get_sCAL_fixed +#define png_get_x_offset_inches_fixed MOZ_PNG_get_x_offs_inches_fx +#define png_get_y_offset_inches_fixed MOZ_PNG_get_y_offs_inches_fx +#define png_have_hwcap MOZ_PNG_have_hwcap +#define png_init_filter_functions MOZ_PNG_init_filt_func +#define png_init_filter_functions_neon MOZ_PNG_init_filt_func_neon +#define png_init_filter_functions_sse2 MOZ_PNG_init_filt_func_sse2 +#define png_init_filter_functions_vsx MOZ_PNG_init_filt_func_vsx +#define png_init_filter_heuristics MOZ_PNG_init_filt_heur +#define png_init_palette_transformations MOZ_PNG_init_palette_transf +#define png_init_rgb_transformations MOZ_PNG_init_rgb_transf +#define png_log16bit MOZ_PNG_log16bit +#define png_log8bit MOZ_PNG_log8bit +#define png_muldiv MOZ_PNG_muldiv +#define png_muldiv_warn MOZ_PNG_muldiv_warn +#define png_pow10 MOZ_PNG_pow10 +#define png_process_data_pause MOZ_PNG_process_data_pause +#define png_process_data_skip MOZ_PNG_process_data_skip +#define png_product2 MOZ_PNG_product2 +#define png_read_filter_row_sub MOZ_PNG_read_filt_row_s +#define png_read_filter_row_up MOZ_PNG_read_filt_row_up +#define png_read_filter_row_avg MOZ_PNG_read_filt_row_a +#define png_read_filter_row_paeth_1byte_pixel MOZ_PNG_read_filt_row_p_1b_px +#define png_read_filter_row_paeth_multibyte_pixel MOZ_PNG_read_filt_row_p_mb_px + +#define png_read_filter_row_sub3_neon MOZ_PNG_read_filt_row_s3_neon +#define png_read_filter_row_sub4_neon MOZ_PNG_read_filt_row_s4_neon +#define png_read_filter_row_up_neon MOZ_PNG_read_filt_row_up_neon +#define png_read_filter_row_avg3_neon MOZ_PNG_read_filt_row_a3_neon +#define png_read_filter_row_avg4_neon MOZ_PNG_read_filt_row_a4_neon +#define png_read_filter_row_paeth3_neon MOZ_PNG_read_filt_row_p3_neon +#define png_read_filter_row_paeth4_neon MOZ_PNG_read_filt_row_p4_neon + +#define png_read_filter_row_sub3_sse2 MOZ_PNG_read_filt_row_s3_sse2 +#define png_read_filter_row_sub4_sse2 MOZ_PNG_read_filt_row_s4_sse2 +#define png_read_filter_row_avg3_sse2 MOZ_PNG_read_filt_row_a3_sse2 +#define png_read_filter_row_avg4_sse2 MOZ_PNG_read_filt_row_a4_sse2 +#define png_read_filter_row_paeth3_sse2 MOZ_PNG_read_filt_row_p3_sse2 +#define png_read_filter_row_paeth4_sse2 MOZ_PNG_read_filt_row_p4_sse2 + +#define png_read_filter_row_sub3_vsx MOZ_PNG_read_filt_row_s3_vsx +#define png_read_filter_row_sub4_vsx MOZ_PNG_read_filt_row_s4_vsx +#define png_read_filter_row_up_vsx MOZ_PNG_read_filt_row_up_vsx +#define png_read_filter_row_avg3_vsx MOZ_PNG_read_filt_row_a3_vsx +#define png_read_filter_row_avg4_vsx MOZ_PNG_read_filt_row_a4_vsx +#define png_read_filter_row_paeth3_vsx MOZ_PNG_read_filt_row_p3_vsx +#define png_read_filter_row_paeth4_vsx MOZ_PNG_read_filt_row_p4_vsx + +#define png_reciprocal MOZ_PNG_reciprocal +#define png_reciprocal2 MOZ_PNG_reciprocal2 +#define png_reset_filter_heuristics MOZ_PNG_reset_filt_heur +#define png_safecat MOZ_PNG_safecat +#define png_set_alpha_mode MOZ_PNG_set_alpha_mode +#define png_set_alpha_mode_fixed MOZ_PNG_set_alpha_mode_fx +#define png_set_background_fixed MOZ_PNG_set_background_fx +#define png_set_cHRM_XYZ MOZ_PNG_set_cHRM_XYZ +#define png_set_cHRM_XYZ_fixed MOZ_PNG_set_cHRM_XYZ_fixed +#define png_set_expand_16 MOZ_PNG_set_expand_16 +#define png_set_filter_heuristics_fixed MOZ_PNG_set_filter_heur_fx +#define png_set_gamma_fixed MOZ_PNG_set_gamma_fixed +#define png_set_sCAL_fixed MOZ_PNG_set_sCAL_fixed +#define png_set_scale_16 MOZ_PNG_set_scale_16 +#define png_set_text_compression_level MOZ_PNG_set_text_c_level +#define png_set_text_compression_mem_level MOZ_PNG_set_text_c_mem_level +#define png_set_text_compression_method MOZ_PNG_set_text_c_method +#define png_set_text_compression_strategy MOZ_PNG_set_text_c_strategy +#define png_set_text_compression_window_bits MOZ_PNG_set_text_c_wnd_bits +#define png_user_version_check MOZ_PNG_user_version_check +#define png_write_chunk_header MOZ_PNG_write_chunk_header +#define png_write_complete_chunk MOZ_PNG_write_complete_chunk +#define png_xy_from_XYZ MOZ_PNG_xy_from_XYZ +#define png_XYZ_from_xy MOZ_PNG_XYZ_from_xy +#define png_XYZ_from_xy_checked MOZ_PNG_XYZ_from_xy_checked +#define png_zlib_claim MOZ_PNG_zlib_claim +#define png_zlib_release MOZ_PNG_zlib_release +#define convert_gamma_value MOZ_convert_gamma_value +#define ppi_from_ppm MOZ_ppi_from_ppm +#define translate_gamma_flags MOZ_translate_gamma_flags + +/* libpng-1.6.x additions */ +#define png_app_error MOZ_PNG_app_err +#define png_app_warning MOZ_PNG_app_warn +#ifndef png_benign_error +# define png_benign_error MOZ_PNG_benign_err +#endif +#ifndef png_chunk_benign_error +# define png_chunk_benign_error MOZ_PNG_chunk_benign_err +#endif +#define png_chunk_report MOZ_PNG_chunk_report +#define png_colorspace_set_ICC MOZ_PNG_cs_set_ICC +#define png_colorspace_set_chromaticities MOZ_PNG_cs_set_chromats +#define png_colorspace_set_endpoints MOZ_PNG_cs_set_endpts +#define png_colorspace_set_gamma MOZ_PNG_cs_set_gamma +#define png_colorspace_set_sRGB MOZ_PNG_cs_set_sRGB +#define png_colorspace_sync MOZ_PNG_cs_sync +#define png_colorspace_sync_info MOZ_PNG_cs_sync_info +#define png_compress_IDAT MOZ_PNG_compress_IDAT +#define png_create_png_struct MOZ_PNG_create_png_struct +#define png_destroy_png_struct MOZ_PNG_destroy_png_struct +#define png_free_buffer_list MOZ_PNG_free_buffer_list +#define png_free_jmpbuf MOZ_PNG_free_jmpbuf +#define png_get_uint_31 MOZ_PNG_get_uint_31 +#define png_icc_check_header MOZ_PNG_icc_check_header +#define png_icc_check_length MOZ_PNG_icc_check_length +#define png_icc_check_tag_table MOZ_PNG_icc_check_tags +#define png_icc_set_sRGB MOZ_PNG_icc_set_sRGB +#define png_malloc_array MOZ_PNG_malloc_array +#define png_malloc_base MOZ_PNG_malloc_base +#define png_realloc_array MOZ_PNG_realloc_array +#define png_zstream_error MOZ_PNG_zstream_error + +#ifndef png_warning +# define png_warning MOZ_PNG_warning +#endif +#ifndef png_chunk_error +# define png_chunk_error MOZ_PNG_chunk_err +#endif +#ifndef png_chunk_warning +# define png_chunk_warning MOZ_PNG_chunk_warn +#endif +#define png_fixed_error MOZ_PNG_fixed_err +#define png_formatted_warning MOZ_PNG_formatted_warning +#define png_warning_parameter MOZ_PNG_warn_param +#define png_warning_parameter_signed MOZ_PNG_warn_param_signed +#define png_warning_parameter_unsigned MOZ_PNG_warn_param_unsigned + +#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) +#define png_set_packing MOZ_PNG_set_packing +#endif + +#endif /* PNGLCONF_H */ diff --git a/media/libpng/pngmem.c b/media/libpng/pngmem.c new file mode 100644 index 0000000000..09ed9c1c99 --- /dev/null +++ b/media/libpng/pngmem.c @@ -0,0 +1,284 @@ + +/* pngmem.c - stub functions for memory allocation + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2014,2016 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all memory allocation. Users who + * need special memory handling are expected to supply replacement + * functions for png_malloc() and png_free(), and to use + * png_create_read_struct_2() and png_create_write_struct_2() to + * identify the replacement functions. + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) +/* Free a png_struct */ +void /* PRIVATE */ +png_destroy_png_struct(png_structrp png_ptr) +{ + if (png_ptr != NULL) + { + /* png_free might call png_error and may certainly call + * png_get_mem_ptr, so fake a temporary png_struct to support this. + */ + png_struct dummy_struct = *png_ptr; + memset(png_ptr, 0, (sizeof *png_ptr)); + png_free(&dummy_struct, png_ptr); + +# ifdef PNG_SETJMP_SUPPORTED + /* We may have a jmp_buf left to deallocate. */ + png_free_jmpbuf(&dummy_struct); +# endif + } +} + +/* Allocate memory. For reasonable files, size should never exceed + * 64K. However, zlib may allocate more than 64K if you don't tell + * it not to. See zconf.h and png.h for more information. zlib does + * need to allocate exactly 64K, so whatever you call here must + * have the ability to do that. + */ +PNG_FUNCTION(png_voidp,PNGAPI +png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; + + ret = png_malloc(png_ptr, size); + + if (ret != NULL) + memset(ret, 0, size); + + return ret; +} + +/* png_malloc_base, an internal function added at libpng 1.6.0, does the work of + * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED. + * Checking and error handling must happen outside this routine; it returns NULL + * if the allocation cannot be done (for any reason.) + */ +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size), + PNG_ALLOCATED) +{ + /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS + * allocators have also been removed in 1.6.0, so any 16-bit system now has + * to implement a user memory handler. This checks to be sure it isn't + * called with big numbers. + */ +#ifndef PNG_USER_MEM_SUPPORTED + PNG_UNUSED(png_ptr) +#endif + + /* Some compilers complain that this is always true. However, it + * can be false when integer overflow happens. + */ + if (size > 0 && size <= PNG_SIZE_MAX +# ifdef PNG_MAX_MALLOC_64K + && size <= 65536U +# endif + ) + { +#ifdef PNG_USER_MEM_SUPPORTED + if (png_ptr != NULL && png_ptr->malloc_fn != NULL) + return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size); + + else +#endif + return malloc((size_t)size); /* checked for truncation above */ + } + + else + return NULL; +} + +#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\ + defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) +/* This is really here only to work round a spurious warning in GCC 4.6 and 4.7 + * that arises because of the checks in png_realloc_array that are repeated in + * png_malloc_array. + */ +static png_voidp +png_malloc_array_checked(png_const_structrp png_ptr, int nelements, + size_t element_size) +{ + png_alloc_size_t req = (png_alloc_size_t)nelements; /* known to be > 0 */ + + if (req <= PNG_SIZE_MAX/element_size) + return png_malloc_base(png_ptr, req * element_size); + + /* The failure case when the request is too large */ + return NULL; +} + +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_malloc_array,(png_const_structrp png_ptr, int nelements, + size_t element_size),PNG_ALLOCATED) +{ + if (nelements <= 0 || element_size == 0) + png_error(png_ptr, "internal error: array alloc"); + + return png_malloc_array_checked(png_ptr, nelements, element_size); +} + +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array, + int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED) +{ + /* These are internal errors: */ + if (add_elements <= 0 || element_size == 0 || old_elements < 0 || + (old_array == NULL && old_elements > 0)) + png_error(png_ptr, "internal error: array realloc"); + + /* Check for overflow on the elements count (so the caller does not have to + * check.) + */ + if (add_elements <= INT_MAX - old_elements) + { + png_voidp new_array = png_malloc_array_checked(png_ptr, + old_elements+add_elements, element_size); + + if (new_array != NULL) + { + /* Because png_malloc_array worked the size calculations below cannot + * overflow. + */ + if (old_elements > 0) + memcpy(new_array, old_array, element_size*(unsigned)old_elements); + + memset((char*)new_array + element_size*(unsigned)old_elements, 0, + element_size*(unsigned)add_elements); + + return new_array; + } + } + + return NULL; /* error */ +} +#endif /* TEXT || sPLT || STORE_UNKNOWN_CHUNKS */ + +/* Various functions that have different error handling are derived from this. + * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate + * function png_malloc_default is also provided. + */ +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; + + if (png_ptr == NULL) + return NULL; + + ret = png_malloc_base(png_ptr, size); + + if (ret == NULL) + png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */ + + return ret; +} + +#ifdef PNG_USER_MEM_SUPPORTED +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size), + PNG_ALLOCATED PNG_DEPRECATED) +{ + png_voidp ret; + + if (png_ptr == NULL) + return NULL; + + /* Passing 'NULL' here bypasses the application provided memory handler. */ + ret = png_malloc_base(NULL/*use malloc*/, size); + + if (ret == NULL) + png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */ + + return ret; +} +#endif /* USER_MEM */ + +/* This function was added at libpng version 1.2.3. The png_malloc_warn() + * function will issue a png_warning and return NULL instead of issuing a + * png_error, if it fails to allocate the requested memory. + */ +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size), + PNG_ALLOCATED) +{ + if (png_ptr != NULL) + { + png_voidp ret = png_malloc_base(png_ptr, size); + + if (ret != NULL) + return ret; + + png_warning(png_ptr, "Out of memory"); + } + + return NULL; +} + +/* Free a pointer allocated by png_malloc(). If ptr is NULL, return + * without taking any action. + */ +void PNGAPI +png_free(png_const_structrp png_ptr, png_voidp ptr) +{ + if (png_ptr == NULL || ptr == NULL) + return; + +#ifdef PNG_USER_MEM_SUPPORTED + if (png_ptr->free_fn != NULL) + png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr); + + else + png_free_default(png_ptr, ptr); +} + +PNG_FUNCTION(void,PNGAPI +png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED) +{ + if (png_ptr == NULL || ptr == NULL) + return; +#endif /* USER_MEM */ + + free(ptr); +} + +#ifdef PNG_USER_MEM_SUPPORTED +/* This function is called when the application wants to use another method + * of allocating and freeing memory. + */ +void PNGAPI +png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr + malloc_fn, png_free_ptr free_fn) +{ + if (png_ptr != NULL) + { + png_ptr->mem_ptr = mem_ptr; + png_ptr->malloc_fn = malloc_fn; + png_ptr->free_fn = free_fn; + } +} + +/* This function returns a pointer to the mem_ptr associated with the user + * functions. The application should free any memory associated with this + * pointer before png_write_destroy and png_read_destroy are called. + */ +png_voidp PNGAPI +png_get_mem_ptr(png_const_structrp png_ptr) +{ + if (png_ptr == NULL) + return NULL; + + return png_ptr->mem_ptr; +} +#endif /* USER_MEM */ +#endif /* READ || WRITE */ diff --git a/media/libpng/pngpread.c b/media/libpng/pngpread.c new file mode 100644 index 0000000000..7d452a76f2 --- /dev/null +++ b/media/libpng/pngpread.c @@ -0,0 +1,1265 @@ + +/* pngpread.c - read a png file in push mode + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + +/* Push model modes */ +#define PNG_READ_SIG_MODE 0 +#define PNG_READ_CHUNK_MODE 1 +#define PNG_READ_IDAT_MODE 2 +#define PNG_READ_tEXt_MODE 4 +#define PNG_READ_zTXt_MODE 5 +#define PNG_READ_DONE_MODE 6 +#define PNG_READ_iTXt_MODE 7 +#define PNG_ERROR_MODE 8 + +#define PNG_PUSH_SAVE_BUFFER_IF_FULL \ +if (png_ptr->push_length + 4 > png_ptr->buffer_size) \ + { png_push_save_buffer(png_ptr); return; } +#define PNG_PUSH_SAVE_BUFFER_IF_LT(N) \ +if (png_ptr->buffer_size < N) \ + { png_push_save_buffer(png_ptr); return; } + +void PNGAPI +png_process_data(png_structrp png_ptr, png_inforp info_ptr, + png_bytep buffer, size_t buffer_size) +{ + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_push_restore_buffer(png_ptr, buffer, buffer_size); + + while (png_ptr->buffer_size) + { + png_process_some_data(png_ptr, info_ptr); + } +} + +size_t PNGAPI +png_process_data_pause(png_structrp png_ptr, int save) +{ + if (png_ptr != NULL) + { + /* It's easiest for the caller if we do the save; then the caller doesn't + * have to supply the same data again: + */ + if (save != 0) + png_push_save_buffer(png_ptr); + else + { + /* This includes any pending saved bytes: */ + size_t remaining = png_ptr->buffer_size; + png_ptr->buffer_size = 0; + + /* So subtract the saved buffer size, unless all the data + * is actually 'saved', in which case we just return 0 + */ + if (png_ptr->save_buffer_size < remaining) + return remaining - png_ptr->save_buffer_size; + } + } + + return 0; +} + +png_uint_32 PNGAPI +png_process_data_skip(png_structrp png_ptr) +{ +/* TODO: Deprecate and remove this API. + * Somewhere the implementation of this seems to have been lost, + * or abandoned. It was only to support some internal back-door access + * to png_struct) in libpng-1.4.x. + */ + png_app_warning(png_ptr, +"png_process_data_skip is not implemented in any current version of libpng"); + return 0; +} + +/* What we do with the incoming data depends on what we were previously + * doing before we ran out of data... + */ +void /* PRIVATE */ +png_process_some_data(png_structrp png_ptr, png_inforp info_ptr) +{ + if (png_ptr == NULL) + return; + + switch (png_ptr->process_mode) + { + case PNG_READ_SIG_MODE: + { + png_push_read_sig(png_ptr, info_ptr); + break; + } + + case PNG_READ_CHUNK_MODE: + { + png_push_read_chunk(png_ptr, info_ptr); + break; + } + + case PNG_READ_IDAT_MODE: + { + png_push_read_IDAT(png_ptr); + break; + } + + default: + { + png_ptr->buffer_size = 0; + break; + } + } +} + +/* Read any remaining signature bytes from the stream and compare them with + * the correct PNG signature. It is possible that this routine is called + * with bytes already read from the signature, either because they have been + * checked by the calling application, or because of multiple calls to this + * routine. + */ +void /* PRIVATE */ +png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr) +{ + size_t num_checked = png_ptr->sig_bytes; /* SAFE, does not exceed 8 */ + size_t num_to_check = 8 - num_checked; + + if (png_ptr->buffer_size < num_to_check) + { + num_to_check = png_ptr->buffer_size; + } + + png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), + num_to_check); + png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check); + + if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) + { + if (num_checked < 4 && + png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) + png_error(png_ptr, "Not a PNG file"); + + else + png_error(png_ptr, "PNG file corrupted by ASCII conversion"); + } + else + { + if (png_ptr->sig_bytes >= 8) + { + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + } + } +} + +void /* PRIVATE */ +png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr) +{ + png_uint_32 chunk_name; +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + int keep; /* unknown handling method */ +#endif + + /* First we make sure we have enough data for the 4-byte chunk name + * and the 4-byte chunk length before proceeding with decoding the + * chunk data. To fully decode each of these chunks, we also make + * sure we have enough data in the buffer for the 4-byte CRC at the + * end of every chunk (except IDAT, which is handled separately). + */ + if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0) + { + png_byte chunk_length[4]; + png_byte chunk_tag[4]; + + PNG_PUSH_SAVE_BUFFER_IF_LT(8) + png_push_fill_buffer(png_ptr, chunk_length, 4); + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); + png_reset_crc(png_ptr); + png_crc_read(png_ptr, chunk_tag, 4); + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); + png_check_chunk_name(png_ptr, png_ptr->chunk_name); + png_check_chunk_length(png_ptr, png_ptr->push_length); + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; + } + + chunk_name = png_ptr->chunk_name; + +#ifdef PNG_READ_APNG_SUPPORTED + if (png_ptr->num_frames_read > 0 && + png_ptr->num_frames_read < info_ptr->num_frames) + { + if (chunk_name == png_IDAT) + { + /* Discard trailing IDATs for the first frame */ + if ((png_ptr->mode & PNG_HAVE_fcTL) != 0 || + png_ptr->num_frames_read > 1) + png_error(png_ptr, "out of place IDAT"); + + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_crc_finish(png_ptr, png_ptr->push_length); + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; + } + + else if (chunk_name == png_fdAT) + { + PNG_PUSH_SAVE_BUFFER_IF_LT(4) + png_ensure_sequence_number(png_ptr, 4); + + if ((png_ptr->mode & PNG_HAVE_fcTL) == 0) + { + /* Discard trailing fdATs for frames other than the first */ + if (png_ptr->num_frames_read < 2) + png_error(png_ptr, "out of place fdAT"); + + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_crc_finish(png_ptr, png_ptr->push_length); + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; + } + + else + { + /* frame data follows */ + png_ptr->idat_size = png_ptr->push_length - 4; + png_ptr->mode |= PNG_HAVE_IDAT; + png_ptr->process_mode = PNG_READ_IDAT_MODE; + } + } + + else if (chunk_name == png_fcTL) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_read_reset(png_ptr); + png_ptr->mode &= ~PNG_HAVE_fcTL; + + png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length); + + if ((png_ptr->mode & PNG_HAVE_fcTL) == 0) + png_error(png_ptr, "missing required fcTL chunk"); + + png_read_reinit(png_ptr, info_ptr); + png_progressive_read_reset(png_ptr); + + if (png_ptr->frame_info_fn != NULL) + (*(png_ptr->frame_info_fn))(png_ptr, png_ptr->num_frames_read); + + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; + } + + else if (chunk_name == png_IEND) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_warning(png_ptr, "Number of actual frames fewer than expected"); + png_crc_finish(png_ptr, png_ptr->push_length); + png_ptr->process_mode = PNG_READ_DONE_MODE; + png_push_have_end(png_ptr, info_ptr); + } + + else + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_warning(png_ptr, "Skipped (ignored) a chunk " + "between APNG chunks"); + png_crc_finish(png_ptr, png_ptr->push_length); + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; + } + + return; + } +#endif /* READ_APNG */ + + if (chunk_name == png_IDAT) + { + if ((png_ptr->mode & PNG_AFTER_IDAT) != 0) + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; + + /* If we reach an IDAT chunk, this means we have read all of the + * header chunks, and we can start reading the image (or if this + * is called after the image has been read - we have an error). + */ + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_error(png_ptr, "Missing IHDR before IDAT"); + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + (png_ptr->mode & PNG_HAVE_PLTE) == 0) + png_error(png_ptr, "Missing PLTE before IDAT"); + + png_ptr->process_mode = PNG_READ_IDAT_MODE; + + if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + if ((png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) == 0) + if (png_ptr->push_length == 0) + return; + + png_ptr->mode |= PNG_HAVE_IDAT; + + if ((png_ptr->mode & PNG_AFTER_IDAT) != 0) + png_benign_error(png_ptr, "Too many IDATs found"); + } + + if (chunk_name == png_IHDR) + { + if (png_ptr->push_length != 13) + png_error(png_ptr, "Invalid IHDR length"); + + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); + } + + else if (chunk_name == png_IEND) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length); + + png_ptr->process_mode = PNG_READ_DONE_MODE; + png_push_have_end(png_ptr, info_ptr); + } + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep); + + if (chunk_name == png_PLTE) + png_ptr->mode |= PNG_HAVE_PLTE; + } +#endif + + else if (chunk_name == png_PLTE) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); + } + + else if (chunk_name == png_IDAT) + { +#ifdef PNG_READ_APNG_SUPPORTED + png_have_info(png_ptr, info_ptr); +#endif + png_ptr->idat_size = png_ptr->push_length; + png_ptr->process_mode = PNG_READ_IDAT_MODE; + png_push_have_info(png_ptr, info_ptr); + png_ptr->zstream.avail_out = + (uInt) PNG_ROWBYTES(png_ptr->pixel_depth, + png_ptr->iwidth) + 1; + png_ptr->zstream.next_out = png_ptr->row_buf; + return; + } + +#ifdef PNG_READ_gAMA_SUPPORTED + else if (png_ptr->chunk_name == png_gAMA) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sBIT_SUPPORTED + else if (png_ptr->chunk_name == png_sBIT) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_cHRM_SUPPORTED + else if (png_ptr->chunk_name == png_cHRM) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sRGB_SUPPORTED + else if (chunk_name == png_sRGB) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_iCCP_SUPPORTED + else if (png_ptr->chunk_name == png_iCCP) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sPLT_SUPPORTED + else if (chunk_name == png_sPLT) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_tRNS_SUPPORTED + else if (chunk_name == png_tRNS) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_bKGD_SUPPORTED + else if (chunk_name == png_bKGD) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_hIST_SUPPORTED + else if (chunk_name == png_hIST) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_pHYs_SUPPORTED + else if (chunk_name == png_pHYs) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_oFFs_SUPPORTED + else if (chunk_name == png_oFFs) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length); + } +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED + else if (chunk_name == png_pCAL) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sCAL_SUPPORTED + else if (chunk_name == png_sCAL) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_tIME_SUPPORTED + else if (chunk_name == png_tIME) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_tEXt_SUPPORTED + else if (chunk_name == png_tEXt) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_zTXt_SUPPORTED + else if (chunk_name == png_zTXt) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_iTXt_SUPPORTED + else if (chunk_name == png_iTXt) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); + } +#endif + +#ifdef PNG_READ_APNG_SUPPORTED + else if (chunk_name == png_acTL) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_acTL(png_ptr, info_ptr, png_ptr->push_length); + } + + else if (chunk_name == png_fcTL) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif /* READ_APNG */ + else + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, + PNG_HANDLE_CHUNK_AS_DEFAULT); + } + + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; +} + +void PNGCBAPI +png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, size_t length) +{ + png_bytep ptr; + + if (png_ptr == NULL) + return; + + ptr = buffer; + if (png_ptr->save_buffer_size != 0) + { + size_t save_size; + + if (length < png_ptr->save_buffer_size) + save_size = length; + + else + save_size = png_ptr->save_buffer_size; + + memcpy(ptr, png_ptr->save_buffer_ptr, save_size); + length -= save_size; + ptr += save_size; + png_ptr->buffer_size -= save_size; + png_ptr->save_buffer_size -= save_size; + png_ptr->save_buffer_ptr += save_size; + } + if (length != 0 && png_ptr->current_buffer_size != 0) + { + size_t save_size; + + if (length < png_ptr->current_buffer_size) + save_size = length; + + else + save_size = png_ptr->current_buffer_size; + + memcpy(ptr, png_ptr->current_buffer_ptr, save_size); + png_ptr->buffer_size -= save_size; + png_ptr->current_buffer_size -= save_size; + png_ptr->current_buffer_ptr += save_size; + } +} + +void /* PRIVATE */ +png_push_save_buffer(png_structrp png_ptr) +{ + if (png_ptr->save_buffer_size != 0) + { + if (png_ptr->save_buffer_ptr != png_ptr->save_buffer) + { + size_t i, istop; + png_bytep sp; + png_bytep dp; + + istop = png_ptr->save_buffer_size; + for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; + i < istop; i++, sp++, dp++) + { + *dp = *sp; + } + } + } + if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > + png_ptr->save_buffer_max) + { + size_t new_max; + png_bytep old_buffer; + + if (png_ptr->save_buffer_size > PNG_SIZE_MAX - + (png_ptr->current_buffer_size + 256)) + { + png_error(png_ptr, "Potential overflow of save_buffer"); + } + + new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256; + old_buffer = png_ptr->save_buffer; + png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, + (size_t)new_max); + + if (png_ptr->save_buffer == NULL) + { + png_free(png_ptr, old_buffer); + png_error(png_ptr, "Insufficient memory for save_buffer"); + } + + if (old_buffer) + memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); + else if (png_ptr->save_buffer_size) + png_error(png_ptr, "save_buffer error"); + png_free(png_ptr, old_buffer); + png_ptr->save_buffer_max = new_max; + } + if (png_ptr->current_buffer_size) + { + memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, + png_ptr->current_buffer_ptr, png_ptr->current_buffer_size); + png_ptr->save_buffer_size += png_ptr->current_buffer_size; + png_ptr->current_buffer_size = 0; + } + png_ptr->save_buffer_ptr = png_ptr->save_buffer; + png_ptr->buffer_size = 0; +} + +void /* PRIVATE */ +png_push_restore_buffer(png_structrp png_ptr, png_bytep buffer, + size_t buffer_length) +{ + png_ptr->current_buffer = buffer; + png_ptr->current_buffer_size = buffer_length; + png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size; + png_ptr->current_buffer_ptr = png_ptr->current_buffer; +} + +void /* PRIVATE */ +png_push_read_IDAT(png_structrp png_ptr) +{ + if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0) + { + png_byte chunk_length[4]; + png_byte chunk_tag[4]; + + /* TODO: this code can be commoned up with the same code in push_read */ +#ifdef PNG_READ_APNG_SUPPORTED + PNG_PUSH_SAVE_BUFFER_IF_LT(12) +#else + PNG_PUSH_SAVE_BUFFER_IF_LT(8) +#endif + png_push_fill_buffer(png_ptr, chunk_length, 4); + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); + png_reset_crc(png_ptr); + png_crc_read(png_ptr, chunk_tag, 4); + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; + +#ifdef PNG_READ_APNG_SUPPORTED + if (png_ptr->chunk_name != png_fdAT && png_ptr->num_frames_read > 0) + { + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) != 0) + { + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + if (png_ptr->frame_end_fn != NULL) + (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read); + png_ptr->num_frames_read++; + return; + } + else + { + if (png_ptr->chunk_name == png_IEND) + png_error(png_ptr, "Not enough image data"); + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_warning(png_ptr, "Skipping (ignoring) a chunk between " + "APNG chunks"); + png_crc_finish(png_ptr, png_ptr->push_length); + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; + return; + } + } + else +#endif +#ifdef PNG_READ_APNG_SUPPORTED + if (png_ptr->chunk_name != png_IDAT && png_ptr->num_frames_read == 0) +#else + if (png_ptr->chunk_name != png_IDAT) +#endif + { + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) + png_error(png_ptr, "Not enough compressed data"); + +#ifdef PNG_READ_APNG_SUPPORTED + if (png_ptr->frame_end_fn != NULL) + (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read); + png_ptr->num_frames_read++; +#endif + + return; + } + + png_ptr->idat_size = png_ptr->push_length; + +#ifdef PNG_READ_APNG_SUPPORTED + if (png_ptr->num_frames_read > 0) + { + png_ensure_sequence_number(png_ptr, 4); + png_ptr->idat_size -= 4; + } +#endif + } + + if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0) + { + size_t save_size = png_ptr->save_buffer_size; + png_uint_32 idat_size = png_ptr->idat_size; + + /* We want the smaller of 'idat_size' and 'current_buffer_size', but they + * are of different types and we don't know which variable has the fewest + * bits. Carefully select the smaller and cast it to the type of the + * larger - this cannot overflow. Do not cast in the following test - it + * will break on either 16-bit or 64-bit platforms. + */ + if (idat_size < save_size) + save_size = (size_t)idat_size; + + else + idat_size = (png_uint_32)save_size; + + png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); + + png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size); + + png_ptr->idat_size -= idat_size; + png_ptr->buffer_size -= save_size; + png_ptr->save_buffer_size -= save_size; + png_ptr->save_buffer_ptr += save_size; + } + + if (png_ptr->idat_size != 0 && png_ptr->current_buffer_size != 0) + { + size_t save_size = png_ptr->current_buffer_size; + png_uint_32 idat_size = png_ptr->idat_size; + + /* We want the smaller of 'idat_size' and 'current_buffer_size', but they + * are of different types and we don't know which variable has the fewest + * bits. Carefully select the smaller and cast it to the type of the + * larger - this cannot overflow. + */ + if (idat_size < save_size) + save_size = (size_t)idat_size; + + else + idat_size = (png_uint_32)save_size; + + png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); + + png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size); + + png_ptr->idat_size -= idat_size; + png_ptr->buffer_size -= save_size; + png_ptr->current_buffer_size -= save_size; + png_ptr->current_buffer_ptr += save_size; + } + + if (png_ptr->idat_size == 0) + { + PNG_PUSH_SAVE_BUFFER_IF_LT(4) + png_crc_finish(png_ptr, 0); + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->zowner = 0; + } +} + +void /* PRIVATE */ +png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer, + size_t buffer_length) +{ + /* The caller checks for a non-zero buffer length. */ + if (!(buffer_length > 0) || buffer == NULL) + png_error(png_ptr, "No IDAT data (internal error)"); + +#ifdef PNG_READ_APNG_SUPPORTED + /* If the app is not APNG-aware, decode only the first frame */ + if ((png_ptr->apng_flags & PNG_APNG_APP) == 0 && + png_ptr->num_frames_read > 0) + { + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; + return; + } +#endif + + /* This routine must process all the data it has been given + * before returning, calling the row callback as required to + * handle the uncompressed results. + */ + png_ptr->zstream.next_in = buffer; + /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */ + png_ptr->zstream.avail_in = (uInt)buffer_length; + + /* Keep going until the decompressed data is all processed + * or the stream marked as finished. + */ + while (png_ptr->zstream.avail_in > 0 && + (png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) + { + int ret; + + /* We have data for zlib, but we must check that zlib + * has someplace to put the results. It doesn't matter + * if we don't expect any results -- it may be the input + * data is just the LZ end code. + */ + if (!(png_ptr->zstream.avail_out > 0)) + { + /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */ + png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth, + png_ptr->iwidth) + 1); + + png_ptr->zstream.next_out = png_ptr->row_buf; + } + + /* Using Z_SYNC_FLUSH here means that an unterminated + * LZ stream (a stream with a missing end code) can still + * be handled, otherwise (Z_NO_FLUSH) a future zlib + * implementation might defer output and therefore + * change the current behavior (see comments in inflate.c + * for why this doesn't happen at present with zlib 1.2.5). + */ + ret = PNG_INFLATE(png_ptr, Z_SYNC_FLUSH); + + /* Check for any failure before proceeding. */ + if (ret != Z_OK && ret != Z_STREAM_END) + { + /* Terminate the decompression. */ + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; + png_ptr->zowner = 0; + + /* This may be a truncated stream (missing or + * damaged end code). Treat that as a warning. + */ + if (png_ptr->row_number >= png_ptr->num_rows || + png_ptr->pass > 6) + png_warning(png_ptr, "Truncated compressed data in IDAT"); + + else + { + if (ret == Z_DATA_ERROR) + png_benign_error(png_ptr, "IDAT: ADLER32 checksum mismatch"); + else + png_error(png_ptr, "Decompression error in IDAT"); + } + + /* Skip the check on unprocessed input */ + return; + } + + /* Did inflate output any data? */ + if (png_ptr->zstream.next_out != png_ptr->row_buf) + { + /* Is this unexpected data after the last row? + * If it is, artificially terminate the LZ output + * here. + */ + if (png_ptr->row_number >= png_ptr->num_rows || + png_ptr->pass > 6) + { + /* Extra data. */ + png_warning(png_ptr, "Extra compressed data in IDAT"); + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; + png_ptr->zowner = 0; + + /* Do no more processing; skip the unprocessed + * input check below. + */ + return; + } + + /* Do we have a complete row? */ + if (png_ptr->zstream.avail_out == 0) + png_push_process_row(png_ptr); + } + + /* And check for the end of the stream. */ + if (ret == Z_STREAM_END) + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; + } + + /* All the data should have been processed, if anything + * is left at this point we have bytes of IDAT data + * after the zlib end code. + */ + if (png_ptr->zstream.avail_in > 0) + png_warning(png_ptr, "Extra compression data in IDAT"); +} + +void /* PRIVATE */ +png_push_process_row(png_structrp png_ptr) +{ + /* 1.5.6: row_info moved out of png_struct to a local here. */ + png_row_info row_info; + + row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */ + row_info.color_type = png_ptr->color_type; + row_info.bit_depth = png_ptr->bit_depth; + row_info.channels = png_ptr->channels; + row_info.pixel_depth = png_ptr->pixel_depth; + row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); + + if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE) + { + if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST) + png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1, + png_ptr->prev_row + 1, png_ptr->row_buf[0]); + else + png_error(png_ptr, "bad adaptive filter value"); + } + + /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before + * 1.5.6, while the buffer really is this big in current versions of libpng + * it may not be in the future, so this was changed just to copy the + * interlaced row count: + */ + memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1); + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + if (png_ptr->transformations != 0) + png_do_read_transformations(png_ptr, &row_info); +#endif + + /* The transformed pixel depth should match the depth now in row_info. */ + if (png_ptr->transformed_pixel_depth == 0) + { + png_ptr->transformed_pixel_depth = row_info.pixel_depth; + if (row_info.pixel_depth > png_ptr->maximum_pixel_depth) + png_error(png_ptr, "progressive row overflow"); + } + + else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth) + png_error(png_ptr, "internal progressive row size calculation error"); + + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Expand interlaced rows to full size */ + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) != 0) + { + if (png_ptr->pass < 6) + png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass, + png_ptr->transformations); + + switch (png_ptr->pass) + { + case 0: + { + int i; + for (i = 0; i < 8 && png_ptr->pass == 0; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */ + } + + if (png_ptr->pass == 2) /* Pass 1 might be empty */ + { + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + if (png_ptr->pass == 4 && png_ptr->height <= 4) + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + if (png_ptr->pass == 6 && png_ptr->height <= 4) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + break; + } + + case 1: + { + int i; + for (i = 0; i < 8 && png_ptr->pass == 1; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 2) /* Skip top 4 generated rows */ + { + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + break; + } + + case 2: + { + int i; + + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 4) /* Pass 3 might be empty */ + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + break; + } + + case 3: + { + int i; + + for (i = 0; i < 4 && png_ptr->pass == 3; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 4) /* Skip top two generated rows */ + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + break; + } + + case 4: + { + int i; + + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 6) /* Pass 5 might be empty */ + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + break; + } + + case 5: + { + int i; + + for (i = 0; i < 2 && png_ptr->pass == 5; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 6) /* Skip top generated row */ + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + break; + } + + default: + case 6: + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + + if (png_ptr->pass != 6) + break; + + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + } + else +#endif + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } +} + +void /* PRIVATE */ +png_read_push_finish_row(png_structrp png_ptr) +{ +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static const png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static const png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static const png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static const png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; + + /* Height of interlace block. This is not currently used - if you need + * it, uncomment it here and in png.h + static const png_byte png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; + */ +#endif + + png_ptr->row_number++; + if (png_ptr->row_number < png_ptr->num_rows) + return; + +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced != 0) + { + png_ptr->row_number = 0; + memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + + do + { + png_ptr->pass++; + if ((png_ptr->pass == 1 && png_ptr->width < 5) || + (png_ptr->pass == 3 && png_ptr->width < 3) || + (png_ptr->pass == 5 && png_ptr->width < 2)) + png_ptr->pass++; + + if (png_ptr->pass > 7) + png_ptr->pass--; + + if (png_ptr->pass >= 7) + break; + + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + if ((png_ptr->transformations & PNG_INTERLACE) != 0) + break; + + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + + } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0); + } +#endif /* READ_INTERLACING */ +} + +void /* PRIVATE */ +png_push_have_info(png_structrp png_ptr, png_inforp info_ptr) +{ + if (png_ptr->info_fn != NULL) + (*(png_ptr->info_fn))(png_ptr, info_ptr); +} + +void /* PRIVATE */ +png_push_have_end(png_structrp png_ptr, png_inforp info_ptr) +{ + if (png_ptr->end_fn != NULL) + (*(png_ptr->end_fn))(png_ptr, info_ptr); +} + +void /* PRIVATE */ +png_push_have_row(png_structrp png_ptr, png_bytep row) +{ + if (png_ptr->row_fn != NULL) + (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number, + (int)png_ptr->pass); +} + +#ifdef PNG_READ_INTERLACING_SUPPORTED +void PNGAPI +png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row, + png_const_bytep new_row) +{ + if (png_ptr == NULL) + return; + + /* new_row is a flag here - if it is NULL then the app callback was called + * from an empty row (see the calls to png_struct::row_fn below), otherwise + * it must be png_ptr->row_buf+1 + */ + if (new_row != NULL) + png_combine_row(png_ptr, old_row, 1/*blocky display*/); +} +#endif /* READ_INTERLACING */ + +void PNGAPI +png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr, + png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, + png_progressive_end_ptr end_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->info_fn = info_fn; + png_ptr->row_fn = row_fn; + png_ptr->end_fn = end_fn; + + png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); +} + +#ifdef PNG_READ_APNG_SUPPORTED +void PNGAPI +png_set_progressive_frame_fn(png_structp png_ptr, + png_progressive_frame_ptr frame_info_fn, + png_progressive_frame_ptr frame_end_fn) +{ + png_ptr->frame_info_fn = frame_info_fn; + png_ptr->frame_end_fn = frame_end_fn; + png_ptr->apng_flags |= PNG_APNG_APP; +} +#endif + +png_voidp PNGAPI +png_get_progressive_ptr(png_const_structrp png_ptr) +{ + if (png_ptr == NULL) + return (NULL); + + return png_ptr->io_ptr; +} +#endif /* PROGRESSIVE_READ */ diff --git a/media/libpng/pngpriv.h b/media/libpng/pngpriv.h new file mode 100644 index 0000000000..3437bd5b8e --- /dev/null +++ b/media/libpng/pngpriv.h @@ -0,0 +1,2209 @@ + +/* pngpriv.h - private declarations for use inside libpng + * + * Copyright (c) 2018-2019 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* The symbols declared in this file (including the functions declared + * as extern) are PRIVATE. They are not part of the libpng public + * interface, and are not recommended for use by regular applications. + * Some of them may become public in the future; others may stay private, + * change in an incompatible way, or even disappear. + * Although the libpng users are not forbidden to include this header, + * they should be well aware of the issues that may arise from doing so. + */ + +#ifndef PNGPRIV_H +#define PNGPRIV_H + +/* Feature Test Macros. The following are defined here to ensure that correctly + * implemented libraries reveal the APIs libpng needs to build and hide those + * that are not needed and potentially damaging to the compilation. + * + * Feature Test Macros must be defined before any system header is included (see + * POSIX 1003.1 2.8.2 "POSIX Symbols." + * + * These macros only have an effect if the operating system supports either + * POSIX 1003.1 or C99, or both. On other operating systems (particularly + * Windows/Visual Studio) there is no effect; the OS specific tests below are + * still required (as of 2011-05-02.) + */ +#ifndef _POSIX_SOURCE +# define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */ +#endif + +#ifndef PNG_VERSION_INFO_ONLY +/* Standard library headers not required by png.h: */ +# include <stdlib.h> +# include <string.h> +#endif + +#define PNGLIB_BUILD /*libpng is being built, not used*/ + +/* If HAVE_CONFIG_H is defined during the build then the build system must + * provide an appropriate "config.h" file on the include path. The header file + * must provide definitions as required below (search for "HAVE_CONFIG_H"); + * see configure.ac for more details of the requirements. The macro + * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on + * 'configure'; define this macro to prevent the configure build including the + * configure generated config.h. Libpng is expected to compile without *any* + * special build system support on a reasonably ANSI-C compliant system. + */ +#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) +# include <config.h> + + /* Pick up the definition of 'restrict' from config.h if it was read: */ +# define PNG_RESTRICT restrict +#endif + +/* To support symbol prefixing it is necessary to know *before* including png.h + * whether the fixed point (and maybe other) APIs are exported, because if they + * are not internal definitions may be required. This is handled below just + * before png.h is included, but load the configuration now if it is available. + */ +#ifndef PNGLCONF_H +# include "pnglibconf.h" +#endif + +/* Local renames may change non-exported API functions from png.h */ +#if defined(PNG_PREFIX) && !defined(PNGPREFIX_H) +# include "pngprefix.h" +#endif + +#ifdef PNG_USER_CONFIG +# include "pngusr.h" + /* These should have been defined in pngusr.h */ +# ifndef PNG_USER_PRIVATEBUILD +# define PNG_USER_PRIVATEBUILD "Custom libpng build" +# endif +# ifndef PNG_USER_DLLFNAME_POSTFIX +# define PNG_USER_DLLFNAME_POSTFIX "Cb" +# endif +#endif + +/* Compile time options. + * ===================== + * In a multi-arch build the compiler may compile the code several times for the + * same object module, producing different binaries for different architectures. + * When this happens configure-time setting of the target host options cannot be + * done and this interferes with the handling of the ARM NEON optimizations, and + * possibly other similar optimizations. Put additional tests here; in general + * this is needed when the same option can be changed at both compile time and + * run time depending on the target OS (i.e. iOS vs Android.) + * + * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because + * this is not possible with certain compilers (Oracle SUN OS CC), as a result + * it is necessary to ensure that all extern functions that *might* be used + * regardless of $(CFLAGS) get declared in this file. The test on __ARM_NEON__ + * below is one example of this behavior because it is controlled by the + * presence or not of -mfpu=neon on the GCC command line, it is possible to do + * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely + * do this. + */ +#ifndef PNG_ARM_NEON_OPT + /* ARM NEON optimizations are being controlled by the compiler settings, + * typically the target FPU. If the FPU has been set to NEON (-mfpu=neon + * with GCC) then the compiler will define __ARM_NEON__ and we can rely + * unconditionally on NEON instructions not crashing, otherwise we must + * disable use of NEON instructions. + * + * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they + * can only be turned on automatically if that is supported too. If + * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail + * to compile with an appropriate #error if ALIGNED_MEMORY has been turned + * off. + * + * Note that gcc-4.9 defines __ARM_NEON instead of the deprecated + * __ARM_NEON__, so we check both variants. + * + * To disable ARM_NEON optimizations entirely, and skip compiling the + * associated assembler code, pass --enable-arm-neon=no to configure + * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS. + */ +# if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \ + defined(PNG_ALIGNED_MEMORY_SUPPORTED) +# define PNG_ARM_NEON_OPT 2 +# else +# define PNG_ARM_NEON_OPT 0 +# endif +#endif + +#if PNG_ARM_NEON_OPT > 0 + /* NEON optimizations are to be at least considered by libpng, so enable the + * callbacks to do this. + */ +# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon + + /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used + * if possible - if __ARM_NEON__ is set and the compiler version is not known + * to be broken. This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can + * be: + * + * 1 The intrinsics code (the default with __ARM_NEON__) + * 2 The hand coded assembler (the default without __ARM_NEON__) + * + * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however + * this is *NOT* supported and may cease to work even after a minor revision + * to libpng. It *is* valid to do this for testing purposes, e.g. speed + * testing or a new compiler, but the results should be communicated to the + * libpng implementation list for incorporation in the next minor release. + */ +# ifndef PNG_ARM_NEON_IMPLEMENTATION +# if defined(__ARM_NEON__) || defined(__ARM_NEON) +# if defined(__clang__) + /* At present it is unknown by the libpng developers which versions + * of clang support the intrinsics, however some or perhaps all + * versions do not work with the assembler so this may be + * irrelevant, so just use the default (do nothing here.) + */ +# elif defined(__GNUC__) + /* GCC 4.5.4 NEON support is known to be broken. 4.6.3 is known to + * work, so if this *is* GCC, or G++, look for a version >4.5 + */ +# if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6) +# define PNG_ARM_NEON_IMPLEMENTATION 2 +# endif /* no GNUC support */ +# endif /* __GNUC__ */ +# else /* !defined __ARM_NEON__ */ + /* The 'intrinsics' code simply won't compile without this -mfpu=neon: + */ +# if !defined(__aarch64__) + /* The assembler code currently does not work on ARM64 */ +# define PNG_ARM_NEON_IMPLEMENTATION 2 +# endif /* __aarch64__ */ +# endif /* __ARM_NEON__ */ +# endif /* !PNG_ARM_NEON_IMPLEMENTATION */ + +# ifndef PNG_ARM_NEON_IMPLEMENTATION + /* Use the intrinsics code by default. */ +# define PNG_ARM_NEON_IMPLEMENTATION 1 +# endif +#endif /* PNG_ARM_NEON_OPT > 0 */ + +#ifndef PNG_MIPS_MSA_OPT +# if defined(__mips_msa) && (__mips_isa_rev >= 5) && defined(PNG_ALIGNED_MEMORY_SUPPORTED) +# define PNG_MIPS_MSA_OPT 2 +# else +# define PNG_MIPS_MSA_OPT 0 +# endif +#endif + +#ifndef PNG_POWERPC_VSX_OPT +# if defined(__PPC64__) && defined(__ALTIVEC__) && defined(__VSX__) +# define PNG_POWERPC_VSX_OPT 2 +# else +# define PNG_POWERPC_VSX_OPT 0 +# endif +#endif + +#ifndef PNG_INTEL_SSE_OPT +# ifdef PNG_INTEL_SSE + /* Only check for SSE if the build configuration has been modified to + * enable SSE optimizations. This means that these optimizations will + * be off by default. See contrib/intel for more details. + */ +# if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \ + defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \ + (defined(_M_IX86_FP) && _M_IX86_FP >= 2) +# define PNG_INTEL_SSE_OPT 1 +# else +# define PNG_INTEL_SSE_OPT 0 +# endif +# else +# define PNG_INTEL_SSE_OPT 0 +# endif +#endif + +#if PNG_INTEL_SSE_OPT > 0 +# ifndef PNG_INTEL_SSE_IMPLEMENTATION +# if defined(__SSE4_1__) || defined(__AVX__) + /* We are not actually using AVX, but checking for AVX is the best + way we can detect SSE4.1 and SSSE3 on MSVC. + */ +# define PNG_INTEL_SSE_IMPLEMENTATION 3 +# elif defined(__SSSE3__) +# define PNG_INTEL_SSE_IMPLEMENTATION 2 +# elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \ + (defined(_M_IX86_FP) && _M_IX86_FP >= 2) +# define PNG_INTEL_SSE_IMPLEMENTATION 1 +# else +# define PNG_INTEL_SSE_IMPLEMENTATION 0 +# endif +# endif + +# if PNG_INTEL_SSE_IMPLEMENTATION > 0 +# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2 +# endif +#else +# define PNG_INTEL_SSE_IMPLEMENTATION 0 +#endif + +#if PNG_MIPS_MSA_OPT > 0 +# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_msa +# ifndef PNG_MIPS_MSA_IMPLEMENTATION +# if defined(__mips_msa) +# if defined(__clang__) +# elif defined(__GNUC__) +# if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7) +# define PNG_MIPS_MSA_IMPLEMENTATION 2 +# endif /* no GNUC support */ +# endif /* __GNUC__ */ +# else /* !defined __mips_msa */ +# define PNG_MIPS_MSA_IMPLEMENTATION 2 +# endif /* __mips_msa */ +# endif /* !PNG_MIPS_MSA_IMPLEMENTATION */ + +# ifndef PNG_MIPS_MSA_IMPLEMENTATION +# define PNG_MIPS_MSA_IMPLEMENTATION 1 +# endif +#endif /* PNG_MIPS_MSA_OPT > 0 */ + +#if PNG_POWERPC_VSX_OPT > 0 +# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_vsx +# define PNG_POWERPC_VSX_IMPLEMENTATION 1 +#endif + + +/* Is this a build of a DLL where compilation of the object modules requires + * different preprocessor settings to those required for a simple library? If + * so PNG_BUILD_DLL must be set. + * + * If libpng is used inside a DLL but that DLL does not export the libpng APIs + * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a + * static library of libpng then link the DLL against that. + */ +#ifndef PNG_BUILD_DLL +# ifdef DLL_EXPORT + /* This is set by libtool when files are compiled for a DLL; libtool + * always compiles twice, even on systems where it isn't necessary. Set + * PNG_BUILD_DLL in case it is necessary: + */ +# define PNG_BUILD_DLL +# else +# ifdef _WINDLL + /* This is set by the Microsoft Visual Studio IDE in projects that + * build a DLL. It can't easily be removed from those projects (it + * isn't visible in the Visual Studio UI) so it is a fairly reliable + * indication that PNG_IMPEXP needs to be set to the DLL export + * attributes. + */ +# define PNG_BUILD_DLL +# else +# ifdef __DLL__ + /* This is set by the Borland C system when compiling for a DLL + * (as above.) + */ +# define PNG_BUILD_DLL +# else + /* Add additional compiler cases here. */ +# endif +# endif +# endif +#endif /* Setting PNG_BUILD_DLL if required */ + +/* See pngconf.h for more details: the builder of the library may set this on + * the command line to the right thing for the specific compilation system or it + * may be automagically set above (at present we know of no system where it does + * need to be set on the command line.) + * + * PNG_IMPEXP must be set here when building the library to prevent pngconf.h + * setting it to the "import" setting for a DLL build. + */ +#ifndef PNG_IMPEXP +# ifdef PNG_BUILD_DLL +# define PNG_IMPEXP PNG_DLL_EXPORT +# else + /* Not building a DLL, or the DLL doesn't require specific export + * definitions. + */ +# define PNG_IMPEXP +# endif +#endif + +/* No warnings for private or deprecated functions in the build: */ +#ifndef PNG_DEPRECATED +# define PNG_DEPRECATED +#endif +#ifndef PNG_PRIVATE +# define PNG_PRIVATE +#endif + +/* Symbol preprocessing support. + * + * To enable listing global, but internal, symbols the following macros should + * always be used to declare an extern data or function object in this file. + */ +#ifndef PNG_INTERNAL_DATA +# define PNG_INTERNAL_DATA(type, name, array) PNG_LINKAGE_DATA type name array +#endif + +#ifndef PNG_INTERNAL_FUNCTION +# define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\ + PNG_LINKAGE_FUNCTION PNG_FUNCTION(type, name, args, PNG_EMPTY attributes) +#endif + +#ifndef PNG_INTERNAL_CALLBACK +# define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\ + PNG_LINKAGE_CALLBACK PNG_FUNCTION(type, (PNGCBAPI name), args,\ + PNG_EMPTY attributes) +#endif + +/* If floating or fixed point APIs are disabled they may still be compiled + * internally. To handle this make sure they are declared as the appropriate + * internal extern function (otherwise the symbol prefixing stuff won't work and + * the functions will be used without definitions.) + * + * NOTE: although all the API functions are declared here they are not all + * actually built! Because the declarations are still made it is necessary to + * fake out types that they depend on. + */ +#ifndef PNG_FP_EXPORT +# ifndef PNG_FLOATING_POINT_SUPPORTED +# define PNG_FP_EXPORT(ordinal, type, name, args)\ + PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY); +# ifndef PNG_VERSION_INFO_ONLY + typedef struct png_incomplete png_double; + typedef png_double* png_doublep; + typedef const png_double* png_const_doublep; + typedef png_double** png_doublepp; +# endif +# endif +#endif +#ifndef PNG_FIXED_EXPORT +# ifndef PNG_FIXED_POINT_SUPPORTED +# define PNG_FIXED_EXPORT(ordinal, type, name, args)\ + PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY); +# endif +#endif + +#include "png.h" + +/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */ +#ifndef PNG_DLL_EXPORT +# define PNG_DLL_EXPORT +#endif + +/* This is a global switch to set the compilation for an installed system + * (a release build). It can be set for testing debug builds to ensure that + * they will compile when the build type is switched to RC or STABLE, the + * default is just to use PNG_LIBPNG_BUILD_BASE_TYPE. Set this in CPPFLAGS + * with either: + * + * -DPNG_RELEASE_BUILD Turns on the release compile path + * -DPNG_RELEASE_BUILD=0 Turns it off + * or in your pngusr.h with + * #define PNG_RELEASE_BUILD=1 Turns on the release compile path + * #define PNG_RELEASE_BUILD=0 Turns it off + */ +#ifndef PNG_RELEASE_BUILD +# define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC) +#endif + +/* SECURITY and SAFETY: + * + * libpng is built with support for internal limits on image dimensions and + * memory usage. These are documented in scripts/pnglibconf.dfa of the + * source and recorded in the machine generated header file pnglibconf.h. + */ + +/* If you are running on a machine where you cannot allocate more + * than 64K of memory at once, uncomment this. While libpng will not + * normally need that much memory in a chunk (unless you load up a very + * large file), zlib needs to know how big of a chunk it can use, and + * libpng thus makes sure to check any memory allocation to verify it + * will fit into memory. + * + * zlib provides 'MAXSEG_64K' which, if defined, indicates the + * same limit and pngconf.h (already included) sets the limit + * if certain operating systems are detected. + */ +#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K) +# define PNG_MAX_MALLOC_64K +#endif + +#ifndef PNG_UNUSED +/* Unused formal parameter warnings are silenced using the following macro + * which is expected to have no bad effects on performance (optimizing + * compilers will probably remove it entirely). Note that if you replace + * it with something other than whitespace, you must include the terminating + * semicolon. + */ +# define PNG_UNUSED(param) (void)param; +#endif + +/* Just a little check that someone hasn't tried to define something + * contradictory. + */ +#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K) +# undef PNG_ZBUF_SIZE +# define PNG_ZBUF_SIZE 65536L +#endif + +/* If warnings or errors are turned off the code is disabled or redirected here. + * From 1.5.4 functions have been added to allow very limited formatting of + * error and warning messages - this code will also be disabled here. + */ +#ifdef PNG_WARNINGS_SUPPORTED +# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p; +#else +# define png_warning_parameter(p,number,string) ((void)0) +# define png_warning_parameter_unsigned(p,number,format,value) ((void)0) +# define png_warning_parameter_signed(p,number,format,value) ((void)0) +# define png_formatted_warning(pp,p,message) ((void)(pp)) +# define PNG_WARNING_PARAMETERS(p) +#endif +#ifndef PNG_ERROR_TEXT_SUPPORTED +# define png_fixed_error(s1,s2) png_err(s1) +#endif + +/* Some fixed point APIs are still required even if not exported because + * they get used by the corresponding floating point APIs. This magic + * deals with this: + */ +#ifdef PNG_FIXED_POINT_SUPPORTED +# define PNGFAPI PNGAPI +#else +# define PNGFAPI /* PRIVATE */ +#endif + +#ifndef PNG_VERSION_INFO_ONLY +/* Other defines specific to compilers can go here. Try to keep + * them inside an appropriate ifdef/endif pair for portability. + */ + +/* C allows up-casts from (void*) to any pointer and (const void*) to any + * pointer to a const object. C++ regards this as a type error and requires an + * explicit, static, cast and provides the static_cast<> rune to ensure that + * const is not cast away. + */ +#ifdef __cplusplus +# define png_voidcast(type, value) static_cast<type>(value) +# define png_constcast(type, value) const_cast<type>(value) +# define png_aligncast(type, value) \ + static_cast<type>(static_cast<void*>(value)) +# define png_aligncastconst(type, value) \ + static_cast<type>(static_cast<const void*>(value)) +#else +# define png_voidcast(type, value) (value) +# ifdef _WIN64 +# ifdef __GNUC__ + typedef unsigned long long png_ptruint; +# else + typedef unsigned __int64 png_ptruint; +# endif +# else + typedef unsigned long png_ptruint; +# endif +# define png_constcast(type, value) ((type)(png_ptruint)(const void*)(value)) +# define png_aligncast(type, value) ((void*)(value)) +# define png_aligncastconst(type, value) ((const void*)(value)) +#endif /* __cplusplus */ + +#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\ + defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) + /* png.c requires the following ANSI-C constants if the conversion of + * floating point to ASCII is implemented therein: + * + * DBL_DIG Maximum number of decimal digits (can be set to any constant) + * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value) + * DBL_MAX Maximum floating point number (can be set to an arbitrary value) + */ +# include <float.h> + +# if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \ + defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC) + /* We need to check that <math.h> hasn't already been included earlier + * as it seems it doesn't agree with <fp.h>, yet we should really use + * <fp.h> if possible. + */ +# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__) +# include <fp.h> +# endif +# else +# include <math.h> +# endif +# if defined(_AMIGA) && defined(__SASC) && defined(_M68881) + /* Amiga SAS/C: We must include builtin FPU functions when compiling using + * MATH=68881 + */ +# include <m68881.h> +# endif +#endif + +/* This provides the non-ANSI (far) memory allocation routines. */ +#if defined(__TURBOC__) && defined(__MSDOS__) +# include <mem.h> +# include <alloc.h> +#endif + +#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \ + defined(_WIN32) || defined(__WIN32__) +# include <windows.h> /* defines _WINDOWS_ macro */ +#endif +#endif /* PNG_VERSION_INFO_ONLY */ + +/* Moved here around 1.5.0beta36 from pngconf.h */ +/* Users may want to use these so they are not private. Any library + * functions that are passed far data must be model-independent. + */ + +/* Memory model/platform independent fns */ +#ifndef PNG_ABORT +# ifdef _WINDOWS_ +# define PNG_ABORT() ExitProcess(0) +# else +# define PNG_ABORT() abort() +# endif +#endif + +/* These macros may need to be architecture dependent. */ +#define PNG_ALIGN_NONE 0 /* do not use data alignment */ +#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */ +#ifdef offsetof +# define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */ +#else +# define PNG_ALIGN_OFFSET -1 /* prevent the use of this */ +#endif +#define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */ + +#ifndef PNG_ALIGN_TYPE + /* Default to using aligned access optimizations and requiring alignment to a + * multiple of the data type size. Override in a compiler specific fashion + * if necessary by inserting tests here: + */ +# define PNG_ALIGN_TYPE PNG_ALIGN_SIZE +#endif + +#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE + /* This is used because in some compiler implementations non-aligned + * structure members are supported, so the offsetof approach below fails. + * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access + * is good for performance. Do not do this unless you have tested the result + * and understand it. + */ +# define png_alignof(type) (sizeof (type)) +#else +# if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET +# define png_alignof(type) offsetof(struct{char c; type t;}, t) +# else +# if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS +# define png_alignof(type) (1) +# endif + /* Else leave png_alignof undefined to prevent use thereof */ +# endif +#endif + +/* This implicitly assumes alignment is always to a power of 2. */ +#ifdef png_alignof +# define png_isaligned(ptr, type)\ + (((type)((const char*)ptr-(const char*)0) & \ + (type)(png_alignof(type)-1)) == 0) +#else +# define png_isaligned(ptr, type) 0 +#endif + +/* End of memory model/platform independent support */ +/* End of 1.5.0beta36 move from pngconf.h */ + +/* CONSTANTS and UTILITY MACROS + * These are used internally by libpng and not exposed in the API + */ + +/* Various modes of operation. Note that after an init, mode is set to + * zero automatically when the structure is created. Three of these + * are defined in png.h because they need to be visible to applications + * that call png_set_unknown_chunk(). + */ +/* #define PNG_HAVE_IHDR 0x01U (defined in png.h) */ +/* #define PNG_HAVE_PLTE 0x02U (defined in png.h) */ +#define PNG_HAVE_IDAT 0x04U +/* #define PNG_AFTER_IDAT 0x08U (defined in png.h) */ +#define PNG_HAVE_IEND 0x10U + /* 0x20U (unused) */ + /* 0x40U (unused) */ + /* 0x80U (unused) */ +#define PNG_HAVE_CHUNK_HEADER 0x100U +#define PNG_WROTE_tIME 0x200U +#define PNG_WROTE_INFO_BEFORE_PLTE 0x400U +#define PNG_BACKGROUND_IS_GRAY 0x800U +#define PNG_HAVE_PNG_SIGNATURE 0x1000U +#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */ + /* 0x4000U (unused) */ +#define PNG_IS_READ_STRUCT 0x8000U /* Else is a write struct */ +#ifdef PNG_APNG_SUPPORTED +#define PNG_HAVE_acTL 0x10000U +#define PNG_HAVE_fcTL 0x20000U +#endif + +/* Flags for the transformations the PNG library does on the image data */ +#define PNG_BGR 0x0001U +#define PNG_INTERLACE 0x0002U +#define PNG_PACK 0x0004U +#define PNG_SHIFT 0x0008U +#define PNG_SWAP_BYTES 0x0010U +#define PNG_INVERT_MONO 0x0020U +#define PNG_QUANTIZE 0x0040U +#define PNG_COMPOSE 0x0080U /* Was PNG_BACKGROUND */ +#define PNG_BACKGROUND_EXPAND 0x0100U +#define PNG_EXPAND_16 0x0200U /* Added to libpng 1.5.2 */ +#define PNG_16_TO_8 0x0400U /* Becomes 'chop' in 1.5.4 */ +#define PNG_RGBA 0x0800U +#define PNG_EXPAND 0x1000U +#define PNG_GAMMA 0x2000U +#define PNG_GRAY_TO_RGB 0x4000U +#define PNG_FILLER 0x8000U +#define PNG_PACKSWAP 0x10000U +#define PNG_SWAP_ALPHA 0x20000U +#define PNG_STRIP_ALPHA 0x40000U +#define PNG_INVERT_ALPHA 0x80000U +#define PNG_USER_TRANSFORM 0x100000U +#define PNG_RGB_TO_GRAY_ERR 0x200000U +#define PNG_RGB_TO_GRAY_WARN 0x400000U +#define PNG_RGB_TO_GRAY 0x600000U /* two bits, RGB_TO_GRAY_ERR|WARN */ +#define PNG_ENCODE_ALPHA 0x800000U /* Added to libpng-1.5.4 */ +#define PNG_ADD_ALPHA 0x1000000U /* Added to libpng-1.2.7 */ +#define PNG_EXPAND_tRNS 0x2000000U /* Added to libpng-1.2.9 */ +#define PNG_SCALE_16_TO_8 0x4000000U /* Added to libpng-1.5.4 */ + /* 0x8000000U unused */ + /* 0x10000000U unused */ + /* 0x20000000U unused */ + /* 0x40000000U unused */ +/* Flags for png_create_struct */ +#define PNG_STRUCT_PNG 0x0001U +#define PNG_STRUCT_INFO 0x0002U + +/* Flags for the png_ptr->flags rather than declaring a byte for each one */ +#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001U +#define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002U /* Added to libpng-1.6.0 */ + /* 0x0004U unused */ +#define PNG_FLAG_ZSTREAM_ENDED 0x0008U /* Added to libpng-1.6.0 */ + /* 0x0010U unused */ + /* 0x0020U unused */ +#define PNG_FLAG_ROW_INIT 0x0040U +#define PNG_FLAG_FILLER_AFTER 0x0080U +#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100U +#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200U +#define PNG_FLAG_CRC_CRITICAL_USE 0x0400U +#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800U +#define PNG_FLAG_ASSUME_sRGB 0x1000U /* Added to libpng-1.5.4 */ +#define PNG_FLAG_OPTIMIZE_ALPHA 0x2000U /* Added to libpng-1.5.4 */ +#define PNG_FLAG_DETECT_UNINITIALIZED 0x4000U /* Added to libpng-1.5.4 */ +/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000U */ +/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000U */ +#define PNG_FLAG_LIBRARY_MISMATCH 0x20000U +#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000U +#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000U +#define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000U /* Added to libpng-1.4.0 */ +#define PNG_FLAG_APP_WARNINGS_WARN 0x200000U /* Added to libpng-1.6.0 */ +#define PNG_FLAG_APP_ERRORS_WARN 0x400000U /* Added to libpng-1.6.0 */ + /* 0x800000U unused */ + /* 0x1000000U unused */ + /* 0x2000000U unused */ + /* 0x4000000U unused */ + /* 0x8000000U unused */ + /* 0x10000000U unused */ + /* 0x20000000U unused */ + /* 0x40000000U unused */ + +#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \ + PNG_FLAG_CRC_ANCILLARY_NOWARN) + +#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \ + PNG_FLAG_CRC_CRITICAL_IGNORE) + +#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \ + PNG_FLAG_CRC_CRITICAL_MASK) + +/* Save typing and make code easier to understand */ + +#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \ + abs((int)((c1).green) - (int)((c2).green)) + \ + abs((int)((c1).blue) - (int)((c2).blue))) + +/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255 + * by dividing by 257 *with rounding*. This macro is exact for the given range. + * See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the + * macro were established by experiment (modifying the added value). The macro + * has a second variant that takes a value already scaled by 255 and divides by + * 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it + * only gives off-by-one errors and only for 0.5% (1 in 200) of the values. + */ +#define PNG_DIV65535(v24) (((v24) + 32895) >> 16) +#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255) + +/* Added to libpng-1.2.6 JB */ +#define PNG_ROWBYTES(pixel_bits, width) \ + ((pixel_bits) >= 8 ? \ + ((size_t)(width) * (((size_t)(pixel_bits)) >> 3)) : \ + (( ((size_t)(width) * ((size_t)(pixel_bits))) + 7) >> 3) ) + +/* This returns the number of trailing bits in the last byte of a row, 0 if the + * last byte is completely full of pixels. It is, in principle, (pixel_bits x + * width) % 8, but that would overflow for large 'width'. The second macro is + * the same except that it returns the number of unused bits in the last byte; + * (8-TRAILBITS), but 0 when TRAILBITS is 0. + * + * NOTE: these macros are intended to be self-evidently correct and never + * overflow on the assumption that pixel_bits is in the range 0..255. The + * arguments are evaluated only once and they can be signed (e.g. as a result of + * the integral promotions). The result of the expression always has type + * (png_uint_32), however the compiler always knows it is in the range 0..7. + */ +#define PNG_TRAILBITS(pixel_bits, width) \ + (((pixel_bits) * ((width) % (png_uint_32)8)) % 8) + +#define PNG_PADBITS(pixel_bits, width) \ + ((8 - PNG_TRAILBITS(pixel_bits, width)) % 8) + +/* PNG_OUT_OF_RANGE returns true if value is outside the range + * ideal-delta..ideal+delta. Each argument is evaluated twice. + * "ideal" and "delta" should be constants, normally simple + * integers, "value" a variable. Added to libpng-1.2.6 JB + */ +#define PNG_OUT_OF_RANGE(value, ideal, delta) \ + ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) ) + +/* Conversions between fixed and floating point, only defined if + * required (to make sure the code doesn't accidentally use float + * when it is supposedly disabled.) + */ +#ifdef PNG_FLOATING_POINT_SUPPORTED +/* The floating point conversion can't overflow, though it can and + * does lose accuracy relative to the original fixed point value. + * In practice this doesn't matter because png_fixed_point only + * stores numbers with very low precision. The png_ptr and s + * arguments are unused by default but are there in case error + * checking becomes a requirement. + */ +#define png_float(png_ptr, fixed, s) (.00001 * (fixed)) + +/* The fixed point conversion performs range checking and evaluates + * its argument multiple times, so must be used with care. The + * range checking uses the PNG specification values for a signed + * 32-bit fixed point value except that the values are deliberately + * rounded-to-zero to an integral value - 21474 (21474.83 is roughly + * (2^31-1) * 100000). 's' is a string that describes the value being + * converted. + * + * NOTE: this macro will raise a png_error if the range check fails, + * therefore it is normally only appropriate to use this on values + * that come from API calls or other sources where an out of range + * error indicates a programming error, not a data error! + * + * NOTE: by default this is off - the macro is not used - because the + * function call saves a lot of code. + */ +#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED +#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\ + ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0)) +#endif +/* else the corresponding function is defined below, inside the scope of the + * cplusplus test. + */ +#endif + +/* Constants for known chunk types. If you need to add a chunk, define the name + * here. For historical reasons these constants have the form png_<name>; i.e. + * the prefix is lower case. Please use decimal values as the parameters to + * match the ISO PNG specification and to avoid relying on the C locale + * interpretation of character values. + * + * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values + * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string + * to be generated if required. + * + * PNG_32b correctly produces a value shifted by up to 24 bits, even on + * architectures where (int) is only 16 bits. + */ +#define PNG_32b(b,s) ((png_uint_32)(b) << (s)) +#define PNG_U32(b1,b2,b3,b4) \ + (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0)) + +/* Constants for known chunk types. + * + * MAINTAINERS: If you need to add a chunk, define the name here. + * For historical reasons these constants have the form png_<name>; i.e. + * the prefix is lower case. Please use decimal values as the parameters to + * match the ISO PNG specification and to avoid relying on the C locale + * interpretation of character values. Please keep the list sorted. + * + * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk + * type. In fact the specification does not express chunk types this way, + * however using a 32-bit value means that the chunk type can be read from the + * stream using exactly the same code as used for a 32-bit unsigned value and + * can be examined far more efficiently (using one arithmetic compare). + * + * Prior to 1.5.6 the chunk type constants were expressed as C strings. The + * libpng API still uses strings for 'unknown' chunks and a macro, + * PNG_STRING_FROM_CHUNK, allows a string to be generated if required. Notice + * that for portable code numeric values must still be used; the string "IHDR" + * is not portable and neither is PNG_U32('I', 'H', 'D', 'R'). + * + * In 1.7.0 the definitions will be made public in png.h to avoid having to + * duplicate the same definitions in application code. + */ +#define png_IDAT PNG_U32( 73, 68, 65, 84) +#define png_IEND PNG_U32( 73, 69, 78, 68) +#define png_IHDR PNG_U32( 73, 72, 68, 82) +#define png_PLTE PNG_U32( 80, 76, 84, 69) +#define png_bKGD PNG_U32( 98, 75, 71, 68) +#define png_cHRM PNG_U32( 99, 72, 82, 77) +#define png_eXIf PNG_U32(101, 88, 73, 102) /* registered July 2017 */ +#define png_fRAc PNG_U32(102, 82, 65, 99) /* registered, not defined */ +#define png_gAMA PNG_U32(103, 65, 77, 65) +#define png_gIFg PNG_U32(103, 73, 70, 103) +#define png_gIFt PNG_U32(103, 73, 70, 116) /* deprecated */ +#define png_gIFx PNG_U32(103, 73, 70, 120) +#define png_hIST PNG_U32(104, 73, 83, 84) +#define png_iCCP PNG_U32(105, 67, 67, 80) +#define png_iTXt PNG_U32(105, 84, 88, 116) +#define png_oFFs PNG_U32(111, 70, 70, 115) +#define png_pCAL PNG_U32(112, 67, 65, 76) +#define png_pHYs PNG_U32(112, 72, 89, 115) +#define png_sBIT PNG_U32(115, 66, 73, 84) +#define png_sCAL PNG_U32(115, 67, 65, 76) +#define png_sPLT PNG_U32(115, 80, 76, 84) +#define png_sRGB PNG_U32(115, 82, 71, 66) +#define png_sTER PNG_U32(115, 84, 69, 82) +#define png_tEXt PNG_U32(116, 69, 88, 116) +#define png_tIME PNG_U32(116, 73, 77, 69) +#define png_tRNS PNG_U32(116, 82, 78, 83) +#define png_zTXt PNG_U32(122, 84, 88, 116) + +#ifdef PNG_APNG_SUPPORTED +#define png_acTL PNG_U32( 97, 99, 84, 76) +#define png_fcTL PNG_U32(102, 99, 84, 76) +#define png_fdAT PNG_U32(102, 100, 65, 84) + +/* For png_struct.apng_flags: */ +#define PNG_FIRST_FRAME_HIDDEN 0x0001U +#define PNG_APNG_APP 0x0002U +#endif + +/* The following will work on (signed char*) strings, whereas the get_uint_32 + * macro will fail on top-bit-set values because of the sign extension. + */ +#define PNG_CHUNK_FROM_STRING(s)\ + PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3]) + +/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is + * signed and the argument is a (char[]) This macro will fail miserably on + * systems where (char) is more than 8 bits. + */ +#define PNG_STRING_FROM_CHUNK(s,c)\ + (void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \ + ((char*)(s))[1]=(char)(((c)>>16) & 0xff),\ + ((char*)(s))[2]=(char)(((c)>>8) & 0xff), \ + ((char*)(s))[3]=(char)((c & 0xff))) + +/* Do the same but terminate with a null character. */ +#define PNG_CSTRING_FROM_CHUNK(s,c)\ + (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0) + +/* Test on flag values as defined in the spec (section 5.4): */ +#define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29)) +#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c)) +#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21)) +#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13)) +#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5)) + +/* Gamma values (new at libpng-1.5.4): */ +#define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */ +#define PNG_GAMMA_MAC_INVERSE 65909 +#define PNG_GAMMA_sRGB_INVERSE 45455 + +/* Almost everything below is C specific; the #defines above can be used in + * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot. + */ +#ifndef PNG_VERSION_INFO_ONLY + +#include "pngstruct.h" +#include "pnginfo.h" + +/* Validate the include paths - the include path used to generate pnglibconf.h + * must match that used in the build, or we must be using pnglibconf.h.prebuilt: + */ +#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM +# error ZLIB_VERNUM != PNG_ZLIB_VERNUM \ + "-I (include path) error: see the notes in pngpriv.h" + /* This means that when pnglibconf.h was built the copy of zlib.h that it + * used is not the same as the one being used here. Because the build of + * libpng makes decisions to use inflateInit2 and inflateReset2 based on the + * zlib version number and because this affects handling of certain broken + * PNG files the -I directives must match. + * + * The most likely explanation is that you passed a -I in CFLAGS. This will + * not work; all the preprocessor directives and in particular all the -I + * directives must be in CPPFLAGS. + */ +#endif + +/* This is used for 16-bit gamma tables -- only the top level pointers are + * const; this could be changed: + */ +typedef const png_uint_16p * png_const_uint_16pp; + +/* Added to libpng-1.5.7: sRGB conversion tables */ +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) +#ifdef PNG_SIMPLIFIED_READ_SUPPORTED +PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]); + /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value, + * 0..65535. This table gives the closest 16-bit answers (no errors). + */ +#endif + +PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]); +PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]); + +#define PNG_sRGB_FROM_LINEAR(linear) \ + ((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \ + + ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8))) + /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB + * encoded value with maximum error 0.646365. Note that the input is not a + * 16-bit value; it has been multiplied by 255! */ +#endif /* SIMPLIFIED_READ/WRITE */ + + +/* Inhibit C++ name-mangling for libpng functions but not for system calls. */ +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* Internal functions; these are not exported from a DLL however because they + * are used within several of the C source files they have to be C extern. + * + * All of these functions must be declared with PNG_INTERNAL_FUNCTION. + */ + +/* Zlib support */ +#define PNG_UNEXPECTED_ZLIB_RETURN (-7) +PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret), + PNG_EMPTY); + /* Used by the zlib handling functions to ensure that z_stream::msg is always + * set before they return. + */ + +#ifdef PNG_WRITE_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr, + png_compression_bufferp *list),PNG_EMPTY); + /* Free the buffer list used by the compressed write code. */ +#endif + +#if defined(PNG_FLOATING_POINT_SUPPORTED) && \ + !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \ + (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \ + defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \ + (defined(PNG_sCAL_SUPPORTED) && \ + defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)) +PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr, + double fp, png_const_charp text),PNG_EMPTY); +#endif + +/* Check the user version string for compatibility, returns false if the version + * numbers aren't compatible. + */ +PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr, + png_const_charp user_png_ver),PNG_EMPTY); + +/* Internal base allocator - no messages, NULL on failure to allocate. This + * does, however, call the application provided allocator and that could call + * png_error (although that would be a bug in the application implementation.) + */ +PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr, + png_alloc_size_t size),PNG_ALLOCATED); + +#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\ + defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) +/* Internal array allocator, outputs no error or warning messages on failure, + * just returns NULL. + */ +PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr, + int nelements, size_t element_size),PNG_ALLOCATED); + +/* The same but an existing array is extended by add_elements. This function + * also memsets the new elements to 0 and copies the old elements. The old + * array is not freed or altered. + */ +PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr, + png_const_voidp array, int old_elements, int add_elements, + size_t element_size),PNG_ALLOCATED); +#endif /* text, sPLT or unknown chunks */ + +/* Magic to create a struct when there is no struct to call the user supplied + * memory allocators. Because error handling has not been set up the memory + * handlers can't safely call png_error, but this is an obscure and undocumented + * restriction so libpng has to assume that the 'free' handler, at least, might + * call png_error. + */ +PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn, + png_free_ptr free_fn),PNG_ALLOCATED); + +/* Free memory from internal libpng struct */ +PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr), + PNG_EMPTY); + +/* Free an allocated jmp_buf (always succeeds) */ +PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY); + +/* Function to allocate memory for zlib. PNGAPI is disallowed. */ +PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size), + PNG_ALLOCATED); + +/* Function to free memory for zlib. PNGAPI is disallowed. */ +PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY); + +/* Next four functions are used internally as callbacks. PNGCBAPI is required + * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to + * PNGCBAPI at 1.5.0 + */ + +PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr, + png_bytep data, size_t length),PNG_EMPTY); + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr, + png_bytep buffer, size_t length),PNG_EMPTY); +#endif + +PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr, + png_bytep data, size_t length),PNG_EMPTY); + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +# ifdef PNG_STDIO_SUPPORTED +PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr), + PNG_EMPTY); +# endif +#endif + +/* Reset the CRC variable */ +PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY); + +/* Write the "data" buffer to whatever output you are using */ +PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr, + png_const_bytep data, size_t length),PNG_EMPTY); + +/* Read and check the PNG file signature */ +PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); + +/* Read the chunk header (length + type name) */ +PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr), + PNG_EMPTY); + +/* Read data from whatever input you are using into the "data" buffer */ +PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data, + size_t length),PNG_EMPTY); + +/* Read bytes into buf, and update png_ptr->crc */ +PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf, + png_uint_32 length),PNG_EMPTY); + +/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */ +PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr, + png_uint_32 skip),PNG_EMPTY); + +/* Read the CRC from the file and compare it to the libpng calculated CRC */ +PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY); + +/* Calculate the CRC over a section of data. Note that we are only + * passing a maximum of 64K on systems that have this as a memory limit, + * since this is the maximum buffer size we can specify. + */ +PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr, + png_const_bytep ptr, size_t length),PNG_EMPTY); + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY); +#endif + +/* Write various chunks */ + +/* Write the IHDR chunk, and update the png_struct with the necessary + * information. + */ +PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, + int compression_method, int filter_method, int interlace_method),PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr, + png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr, + png_const_bytep row_data, png_alloc_size_t row_data_length, int flush), + PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY); + +#ifdef PNG_WRITE_gAMA_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr, + png_fixed_point file_gamma),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_sBIT_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr, + png_const_color_8p sbit, int color_type),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_cHRM_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr, + const png_xy *xy), PNG_EMPTY); + /* The xy value must have been previously validated */ +#endif + +#ifdef PNG_WRITE_sRGB_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr, + int intent),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_eXIf_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_eXIf,(png_structrp png_ptr, + png_bytep exif, int num_exif),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_iCCP_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr, + png_const_charp name, png_const_bytep profile), PNG_EMPTY); + /* The profile must have been previously validated for correctness, the + * length comes from the first four bytes. Only the base, deflate, + * compression is supported. + */ +#endif + +#ifdef PNG_WRITE_sPLT_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr, + png_const_sPLT_tp palette),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_tRNS_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr, + png_const_bytep trans, png_const_color_16p values, int number, + int color_type),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_bKGD_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr, + png_const_color_16p values, int color_type),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_hIST_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr, + png_const_uint_16p hist, int num_hist),PNG_EMPTY); +#endif + +/* Chunks that have keywords */ +#ifdef PNG_WRITE_tEXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr, + png_const_charp key, png_const_charp text, size_t text_len),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_zTXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp + key, png_const_charp text, int compression),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_iTXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr, + int compression, png_const_charp key, png_const_charp lang, + png_const_charp lang_key, png_const_charp text),PNG_EMPTY); +#endif + +#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */ +PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr, + png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_oFFs_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr, + png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_pCAL_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr, + png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams, + png_const_charp units, png_charpp params),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_pHYs_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr, + png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit, + int unit_type),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_tIME_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr, + png_const_timep mod_time),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_sCAL_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr, + int unit, png_const_charp width, png_const_charp height),PNG_EMPTY); +#endif + +/* Called when finished processing a row of data */ +PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr), + PNG_EMPTY); + +/* Internal use only. Called before first row of data */ +PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr), + PNG_EMPTY); + +/* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an + * array of png_ptr->width pixels. If the image is not interlaced or this + * is the final pass this just does a memcpy, otherwise the "display" flag + * is used to determine whether to copy pixels that are not in the current pass. + * + * Because 'png_do_read_interlace' (below) replicates pixels this allows this + * function to achieve the documented 'blocky' appearance during interlaced read + * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row' + * are not changed if they are not in the current pass, when display is 0. + * + * 'display' must be 0 or 1, otherwise the memcpy will be done regardless. + * + * The API always reads from the png_struct row buffer and always assumes that + * it is full width (png_do_read_interlace has already been called.) + * + * This function is only ever used to write to row buffers provided by the + * caller of the relevant libpng API and the row must have already been + * transformed by the read transformations. + * + * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed + * bitmasks for use within the code, otherwise runtime generated masks are used. + * The default is compile time masks. + */ +#ifndef PNG_USE_COMPILE_TIME_MASKS +# define PNG_USE_COMPILE_TIME_MASKS 1 +#endif +PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr, + png_bytep row, int display),PNG_EMPTY); + +#ifdef PNG_READ_INTERLACING_SUPPORTED +/* Expand an interlaced row: the 'row_info' describes the pass data that has + * been read in and must correspond to the pixels in 'row', the pixels are + * expanded (moved apart) in 'row' to match the final layout, when doing this + * the pixels are *replicated* to the intervening space. This is essential for + * the correct operation of png_combine_row, above. + */ +PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info, + png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY); +#endif + +/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */ + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED +/* Grab pixels out of a row for an interlaced pass */ +PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info, + png_bytep row, int pass),PNG_EMPTY); +#endif + +/* Unfilter a row: check the filter value before calling this, there is no point + * calling it for PNG_FILTER_VALUE_NONE. + */ +PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop + row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY); + +#if PNG_ARM_NEON_OPT > 0 +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info, + png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +#endif + +#if PNG_MIPS_MSA_OPT > 0 +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_msa,(png_row_infop row_info, + png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_msa,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_msa,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_msa,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_msa,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_msa,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_msa,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +#endif + +#if PNG_POWERPC_VSX_OPT > 0 +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_vsx,(png_row_infop row_info, + png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_vsx,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_vsx,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_vsx,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_vsx,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_vsx,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_vsx,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +#endif + +#if PNG_INTEL_SSE_IMPLEMENTATION > 0 +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +#endif + +/* Choose the best filter to use and filter the row data */ +PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr, + png_row_infop row_info),PNG_EMPTY); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr, + png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY); + /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer + * is NULL the function checks, instead, for the end of the stream. In this + * case a benign error will be issued if the stream end is not found or if + * extra data has to be consumed. + */ +PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr), + PNG_EMPTY); + /* This cleans up when the IDAT LZ stream does not end when the last image + * byte is read; there is still some pending input. + */ + +PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr), + PNG_EMPTY); + /* Finish a row while reading, dealing with interlacing passes, etc. */ +#endif /* SEQUENTIAL_READ */ + +/* Initialize the row buffers, etc. */ +PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY); + +#if ZLIB_VERNUM >= 0x1240 +PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush), + PNG_EMPTY); +# define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush) +#else /* Zlib < 1.2.4 */ +# define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush) +#endif /* Zlib < 1.2.4 */ + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +/* Optional call to update the users info structure */ +PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +#endif + +/* Shared transform functions, defined in pngtran.c */ +#if defined(PNG_WRITE_FILLER_SUPPORTED) || \ + defined(PNG_READ_STRIP_ALPHA_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info, + png_bytep row, int at_start),PNG_EMPTY); +#endif + +#ifdef PNG_16BIT_SUPPORTED +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info, + png_bytep row),PNG_EMPTY); +#endif +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ + defined(PNG_WRITE_PACKSWAP_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info, + png_bytep row),PNG_EMPTY); +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info, + png_bytep row),PNG_EMPTY); +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info, + png_bytep row),PNG_EMPTY); +#endif + +/* The following decodes the appropriate chunks, and does error correction, + * then calls the appropriate callback for the chunk if it is valid. + */ + +/* Decode the IHDR chunk */ +PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); + +#ifdef PNG_READ_bKGD_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_eXIf_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_eXIf,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_gAMA_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_hIST_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_iCCP_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif /* READ_iCCP */ + +#ifdef PNG_READ_iTXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_sPLT_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif /* READ_sPLT */ + +#ifdef PNG_READ_sRGB_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_tIME_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_tRNS_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_const_structrp png_ptr, + png_uint_32 chunk_name),PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(void,png_check_chunk_length,(png_const_structrp png_ptr, + png_uint_32 chunk_length),PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY); + /* This is the function that gets called for unknown chunks. The 'keep' + * argument is either non-zero for a known chunk that has been set to be + * handled as unknown or zero for an unknown chunk. By default the function + * just skips the chunk or errors out if it is critical. + */ + +#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\ + defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED) +PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling, + (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY); + /* Exactly as the API png_handle_as_unknown() except that the argument is a + * 32-bit chunk name, not a string. + */ +#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */ + +/* Handle the transformations for reading and writing */ +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr, + png_row_infop row_info),PNG_EMPTY); +#endif +#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr, + png_row_infop row_info),PNG_EMPTY); +#endif + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr), + PNG_EMPTY); +#endif + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr), + PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr, + png_bytep buffer, size_t buffer_length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr, + png_bytep buffer, size_t buffer_length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr), + PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr, + png_bytep row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr), + PNG_EMPTY); +# ifdef PNG_READ_tEXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +# endif +# ifdef PNG_READ_zTXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +# endif +# ifdef PNG_READ_iTXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +# endif + +#endif /* PROGRESSIVE_READ */ + +#ifdef PNG_APNG_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_ensure_fcTL_is_valid,(png_structp png_ptr, + png_uint_32 width, png_uint_32 height, + png_uint_32 x_offset, png_uint_32 y_offset, + png_uint_16 delay_num, png_uint_16 delay_den, + png_byte dispose_op, png_byte blend_op),PNG_EMPTY); + +#ifdef PNG_READ_APNG_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_acTL,(png_structp png_ptr, + png_infop info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_handle_fcTL,(png_structp png_ptr, + png_infop info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_handle_fdAT,(png_structp png_ptr, + png_infop info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_have_info,(png_structp png_ptr, + png_infop info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_ensure_sequence_number,(png_structp png_ptr, + png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_reset,(png_structp png_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_reinit,(png_structp png_ptr, + png_infop info_ptr),PNG_EMPTY); +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_progressive_read_reset,(png_structp png_ptr), + PNG_EMPTY); +#endif /* PROGRESSIVE_READ */ +#endif /* READ_APNG */ + +#ifdef PNG_WRITE_APNG_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_acTL,(png_structp png_ptr, + png_uint_32 num_frames, png_uint_32 num_plays),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_write_fcTL,(png_structp png_ptr, + png_uint_32 width, png_uint_32 height, + png_uint_32 x_offset, png_uint_32 y_offset, + png_uint_16 delay_num, png_uint_16 delay_den, + png_byte dispose_op, png_byte blend_op),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_write_fdAT,(png_structp png_ptr, + png_const_bytep data, png_size_t length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_write_reset,(png_structp png_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_write_reinit,(png_structp png_ptr, + png_infop info_ptr, png_uint_32 width, png_uint_32 height),PNG_EMPTY); +#endif /* WRITE_APNG */ +#endif /* APNG */ + +/* Added at libpng version 1.6.0 */ +#ifdef PNG_GAMMA_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY); + /* Set the colorspace gamma with a value provided by the application or by + * the gAMA chunk on read. The value will override anything set by an ICC + * profile. + */ + +PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr, + png_inforp info_ptr), PNG_EMPTY); + /* Synchronize the info 'valid' flags with the colorspace */ + +PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr, + png_inforp info_ptr), PNG_EMPTY); + /* Copy the png_struct colorspace to the info_struct and call the above to + * synchronize the flags. Checks for NULL info_ptr and does nothing. + */ +#endif + +/* Added at libpng version 1.4.0 */ +#ifdef PNG_COLORSPACE_SUPPORTED +/* These internal functions are for maintaining the colorspace structure within + * a png_info or png_struct (or, indeed, both). + */ +PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities, + (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy, + int preferred), PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints, + (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ, + int preferred), PNG_EMPTY); + +#ifdef PNG_sRGB_SUPPORTED +PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr, + png_colorspacerp colorspace, int intent), PNG_EMPTY); + /* This does set the colorspace gAMA and cHRM values too, but doesn't set the + * flags to write them, if it returns false there was a problem and an error + * message has already been output (but the colorspace may still need to be + * synced to record the invalid flag). + */ +#endif /* sRGB */ + +#ifdef PNG_iCCP_SUPPORTED +PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_const_charp name, + png_uint_32 profile_length, png_const_bytep profile, int color_type), + PNG_EMPTY); + /* The 'name' is used for information only */ + +/* Routines for checking parts of an ICC profile. */ +#ifdef PNG_READ_iCCP_SUPPORTED +PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_const_charp name, + png_uint_32 profile_length), PNG_EMPTY); +#endif /* READ_iCCP */ +PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_const_charp name, + png_uint_32 profile_length, + png_const_bytep profile /* first 132 bytes only */, int color_type), + PNG_EMPTY); +PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_const_charp name, + png_uint_32 profile_length, + png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY); +#ifdef PNG_sRGB_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,( + png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_bytep profile, uLong adler), PNG_EMPTY); + /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may + * be zero to indicate that it is not available. It is used, if provided, + * as a fast check on the profile when checking to see if it is sRGB. + */ +#endif +#endif /* iCCP */ + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients, + (png_structrp png_ptr), PNG_EMPTY); + /* Set the rgb_to_gray coefficients from the colorspace Y values */ +#endif /* READ_RGB_TO_GRAY */ +#endif /* COLORSPACE */ + +/* Added at libpng version 1.4.0 */ +PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_type, int compression_type, + int filter_type),PNG_EMPTY); + +/* Added at libpng version 1.5.10 */ +#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \ + defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes, + (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY); +#endif + +#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr, + png_const_charp name),PNG_NORETURN); +#endif + +/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite + * the end. Always leaves the buffer nul terminated. Never errors out (and + * there is no error code.) + */ +PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize, + size_t pos, png_const_charp string),PNG_EMPTY); + +/* Various internal functions to handle formatted warning messages, currently + * only implemented for warnings. + */ +#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED) +/* Utility to dump an unsigned value into a buffer, given a start pointer and + * and end pointer (which should point just *beyond* the end of the buffer!) + * Returns the pointer to the start of the formatted string. This utility only + * does unsigned values. + */ +PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start, + png_charp end, int format, png_alloc_size_t number),PNG_EMPTY); + +/* Convenience macro that takes an array: */ +#define PNG_FORMAT_NUMBER(buffer,format,number) \ + png_format_number(buffer, buffer + (sizeof buffer), format, number) + +/* Suggested size for a number buffer (enough for 64 bits and a sign!) */ +#define PNG_NUMBER_BUFFER_SIZE 24 + +/* These are the integer formats currently supported, the name is formed from + * the standard printf(3) format string. + */ +#define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */ +#define PNG_NUMBER_FORMAT_02u 2 +#define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */ +#define PNG_NUMBER_FORMAT_02d 2 +#define PNG_NUMBER_FORMAT_x 3 +#define PNG_NUMBER_FORMAT_02x 4 +#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */ +#endif + +#ifdef PNG_WARNINGS_SUPPORTED +/* New defines and members adding in libpng-1.5.4 */ +# define PNG_WARNING_PARAMETER_SIZE 32 +# define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */ + +/* An l-value of this type has to be passed to the APIs below to cache the + * values of the parameters to a formatted warning message. + */ +typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][ + PNG_WARNING_PARAMETER_SIZE]; + +PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p, + int number, png_const_charp string),PNG_EMPTY); + /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters, + * including the trailing '\0'. + */ +PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned, + (png_warning_parameters p, int number, int format, png_alloc_size_t value), + PNG_EMPTY); + /* Use png_alloc_size_t because it is an unsigned type as big as any we + * need to output. Use the following for a signed value. + */ +PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed, + (png_warning_parameters p, int number, int format, png_int_32 value), + PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr, + png_warning_parameters p, png_const_charp message),PNG_EMPTY); + /* 'message' follows the X/Open approach of using @1, @2 to insert + * parameters previously supplied using the above functions. Errors in + * specifying the parameters will simply result in garbage substitutions. + */ +#endif + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +/* Application errors (new in 1.6); use these functions (declared below) for + * errors in the parameters or order of API function calls on read. The + * 'warning' should be used for an error that can be handled completely; the + * 'error' for one which can be handled safely but which may lose application + * information or settings. + * + * By default these both result in a png_error call prior to release, while in a + * released version the 'warning' is just a warning. However if the application + * explicitly disables benign errors (explicitly permitting the code to lose + * information) they both turn into warnings. + * + * If benign errors aren't supported they end up as the corresponding base call + * (png_warning or png_error.) + */ +PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr, + png_const_charp message),PNG_EMPTY); + /* The application provided invalid parameters to an API function or called + * an API function at the wrong time, libpng can completely recover. + */ + +PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr, + png_const_charp message),PNG_EMPTY); + /* As above but libpng will ignore the call, or attempt some other partial + * recovery from the error. + */ +#else +# define png_app_warning(pp,s) png_warning(pp,s) +# define png_app_error(pp,s) png_error(pp,s) +#endif + +PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr, + png_const_charp message, int error),PNG_EMPTY); + /* Report a recoverable issue in chunk data. On read this is used to report + * a problem found while reading a particular chunk and the + * png_chunk_benign_error or png_chunk_warning function is used as + * appropriate. On write this is used to report an error that comes from + * data set via an application call to a png_set_ API and png_app_error or + * png_app_warning is used as appropriate. + * + * The 'error' parameter must have one of the following values: + */ +#define PNG_CHUNK_WARNING 0 /* never an error */ +#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */ +#define PNG_CHUNK_ERROR 2 /* always an error */ + +/* ASCII to FP interfaces, currently only implemented if sCAL + * support is required. + */ +#if defined(PNG_sCAL_SUPPORTED) +/* MAX_DIGITS is actually the maximum number of characters in an sCAL + * width or height, derived from the precision (number of significant + * digits - a build time settable option) and assumptions about the + * maximum ridiculous exponent. + */ +#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/) + +#ifdef PNG_FLOATING_POINT_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr, + png_charp ascii, size_t size, double fp, unsigned int precision), + PNG_EMPTY); +#endif /* FLOATING_POINT */ + +#ifdef PNG_FIXED_POINT_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr, + png_charp ascii, size_t size, png_fixed_point fp),PNG_EMPTY); +#endif /* FIXED_POINT */ +#endif /* sCAL */ + +#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) +/* An internal API to validate the format of a floating point number. + * The result is the index of the next character. If the number is + * not valid it will be the index of a character in the supposed number. + * + * The format of a number is defined in the PNG extensions specification + * and this API is strictly conformant to that spec, not anyone elses! + * + * The format as a regular expression is: + * + * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)? + * + * or: + * + * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)? + * + * The complexity is that either integer or fraction must be present and the + * fraction is permitted to have no digits only if the integer is present. + * + * NOTE: The dangling E problem. + * There is a PNG valid floating point number in the following: + * + * PNG floating point numbers are not greedy. + * + * Working this out requires *TWO* character lookahead (because of the + * sign), the parser does not do this - it will fail at the 'r' - this + * doesn't matter for PNG sCAL chunk values, but it requires more care + * if the value were ever to be embedded in something more complex. Use + * ANSI-C strtod if you need the lookahead. + */ +/* State table for the parser. */ +#define PNG_FP_INTEGER 0 /* before or in integer */ +#define PNG_FP_FRACTION 1 /* before or in fraction */ +#define PNG_FP_EXPONENT 2 /* before or in exponent */ +#define PNG_FP_STATE 3 /* mask for the above */ +#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */ +#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */ +#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */ +#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */ +#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */ + +/* These three values don't affect the parser. They are set but not used. + */ +#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */ +#define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */ +#define PNG_FP_NONZERO 256 /* A non-zero value */ +#define PNG_FP_STICKY 448 /* The above three flags */ + +/* This is available for the caller to store in 'state' if required. Do not + * call the parser after setting it (the parser sometimes clears it.) + */ +#define PNG_FP_INVALID 512 /* Available for callers as a distinct value */ + +/* Result codes for the parser (boolean - true meants ok, false means + * not ok yet.) + */ +#define PNG_FP_MAYBE 0 /* The number may be valid in the future */ +#define PNG_FP_OK 1 /* The number is valid */ + +/* Tests on the sticky non-zero and negative flags. To pass these checks + * the state must also indicate that the whole number is valid - this is + * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this + * is equivalent to PNG_FP_OK above.) + */ +#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO) + /* NZ_MASK: the string is valid and a non-zero negative value */ +#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO) + /* Z MASK: the string is valid and a non-zero value. */ + /* PNG_FP_SAW_DIGIT: the string is valid. */ +#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT) +#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK) +#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK) + +/* The actual parser. This can be called repeatedly. It updates + * the index into the string and the state variable (which must + * be initialized to 0). It returns a result code, as above. There + * is no point calling the parser any more if it fails to advance to + * the end of the string - it is stuck on an invalid character (or + * terminated by '\0'). + * + * Note that the pointer will consume an E or even an E+ and then leave + * a 'maybe' state even though a preceding integer.fraction is valid. + * The PNG_FP_WAS_VALID flag indicates that a preceding substring was + * a valid number. It's possible to recover from this by calling + * the parser again (from the start, with state 0) but with a string + * that omits the last character (i.e. set the size to the index of + * the problem character.) This has not been tested within libpng. + */ +PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string, + size_t size, int *statep, png_size_tp whereami),PNG_EMPTY); + +/* This is the same but it checks a complete string and returns true + * only if it just contains a floating point number. As of 1.5.4 this + * function also returns the state at the end of parsing the number if + * it was valid (otherwise it returns 0.) This can be used for testing + * for negative or zero values using the sticky flag. + */ +PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string, + size_t size),PNG_EMPTY); +#endif /* pCAL || sCAL */ + +#if defined(PNG_GAMMA_SUPPORTED) ||\ + defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED) +/* Added at libpng version 1.5.0 */ +/* This is a utility to provide a*times/div (rounded) and indicate + * if there is an overflow. The result is a boolean - false (0) + * for overflow, true (1) if no overflow, in which case *res + * holds the result. + */ +PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a, + png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY); +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED) +/* Same deal, but issue a warning on overflow and return 0. */ +PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn, + (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by, + png_int_32 divided_by),PNG_EMPTY); +#endif + +#ifdef PNG_GAMMA_SUPPORTED +/* Calculate a reciprocal - used for gamma values. This returns + * 0 if the argument is 0 in order to maintain an undefined value; + * there are no warnings. + */ +PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a), + PNG_EMPTY); + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* The same but gives a reciprocal of the product of two fixed point + * values. Accuracy is suitable for gamma calculations but this is + * not exact - use png_muldiv for that. Only required at present on read. + */ +PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a, + png_fixed_point b),PNG_EMPTY); +#endif + +/* Return true if the gamma value is significantly different from 1.0 */ +PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value), + PNG_EMPTY); +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* Internal fixed point gamma correction. These APIs are called as + * required to convert single values - they don't need to be fast, + * they are not used when processing image pixel values. + * + * While the input is an 'unsigned' value it must actually be the + * correct bit value - 0..255 or 0..65535 as required. + */ +PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr, + unsigned int value, png_fixed_point gamma_value),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value, + png_fixed_point gamma_value),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value, + png_fixed_point gamma_value),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr), + PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr, + int bit_depth),PNG_EMPTY); +#endif + +/* SIMPLIFIED READ/WRITE SUPPORT */ +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) +/* The internal structure that png_image::opaque points to. */ +typedef struct png_control +{ + png_structp png_ptr; + png_infop info_ptr; + png_voidp error_buf; /* Always a jmp_buf at present. */ + + png_const_bytep memory; /* Memory buffer. */ + size_t size; /* Size of the memory buffer. */ + + unsigned int for_write :1; /* Otherwise it is a read structure */ + unsigned int owned_file :1; /* We own the file in io_ptr */ +} png_control; + +/* Return the pointer to the jmp_buf from a png_control: necessary because C + * does not reveal the type of the elements of jmp_buf. + */ +#ifdef __cplusplus +# define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0]) +#else +# define png_control_jmp_buf(pc) ((pc)->error_buf) +#endif + +/* Utility to safely execute a piece of libpng code catching and logging any + * errors that might occur. Returns true on success, false on failure (either + * of the function or as a result of a png_error.) + */ +PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr, + png_const_charp error_message),PNG_NORETURN); + +#ifdef PNG_WARNINGS_SUPPORTED +PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr, + png_const_charp warning_message),PNG_EMPTY); +#else +# define png_safe_warning 0/*dummy argument*/ +#endif + +PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image, + int (*function)(png_voidp), png_voidp arg),PNG_EMPTY); + +/* Utility to log an error; this also cleans up the png_image; the function + * always returns 0 (false). + */ +PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image, + png_const_charp error_message),PNG_EMPTY); + +#ifndef PNG_SIMPLIFIED_READ_SUPPORTED +/* png_image_free is used by the write code but not exported */ +PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY); +#endif /* !SIMPLIFIED_READ */ + +#endif /* SIMPLIFIED READ/WRITE */ + +/* These are initialization functions for hardware specific PNG filter + * optimizations; list these here then select the appropriate one at compile + * time using the macro PNG_FILTER_OPTIMIZATIONS. If the macro is not defined + * the generic code is used. + */ +#ifdef PNG_FILTER_OPTIMIZATIONS +PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr, + unsigned int bpp), PNG_EMPTY); + /* Just declare the optimization that will be used */ +#else + /* List *all* the possible optimizations here - this branch is required if + * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in + * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing. + */ +# if PNG_ARM_NEON_OPT > 0 +PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon, + (png_structp png_ptr, unsigned int bpp), PNG_EMPTY); +#endif + +#if PNG_MIPS_MSA_OPT > 0 +PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_msa, + (png_structp png_ptr, unsigned int bpp), PNG_EMPTY); +#endif + +# if PNG_INTEL_SSE_IMPLEMENTATION > 0 +PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2, + (png_structp png_ptr, unsigned int bpp), PNG_EMPTY); +# endif +#endif + +PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr, + png_const_charp key, png_bytep new_key), PNG_EMPTY); + +#if PNG_ARM_NEON_IMPLEMENTATION == 1 +PNG_INTERNAL_FUNCTION(void, + png_riffle_palette_neon, + (png_structrp), + PNG_EMPTY); +PNG_INTERNAL_FUNCTION(int, + png_do_expand_palette_rgba8_neon, + (png_structrp, + png_row_infop, + png_const_bytep, + const png_bytepp, + const png_bytepp), + PNG_EMPTY); +PNG_INTERNAL_FUNCTION(int, + png_do_expand_palette_rgb8_neon, + (png_structrp, + png_row_infop, + png_const_bytep, + const png_bytepp, + const png_bytepp), + PNG_EMPTY); +#endif + +/* Maintainer: Put new private prototypes here ^ */ + +#include "pngdebug.h" + +#ifdef __cplusplus +} +#endif + +#endif /* PNG_VERSION_INFO_ONLY */ +#endif /* PNGPRIV_H */ diff --git a/media/libpng/pngread.c b/media/libpng/pngread.c new file mode 100644 index 0000000000..0153539c6b --- /dev/null +++ b/media/libpng/pngread.c @@ -0,0 +1,4305 @@ + +/* pngread.c - read a PNG file + * + * Copyright (c) 2018-2019 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file contains routines that an application calls directly to + * read a PNG file or stream. + */ + +#include "pngpriv.h" +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) && defined(PNG_STDIO_SUPPORTED) +# include <errno.h> +#endif + +#ifdef PNG_READ_SUPPORTED + +/* Create a PNG structure for reading, and allocate any memory needed. */ +PNG_FUNCTION(png_structp,PNGAPI +png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED) +{ +#ifndef PNG_USER_MEM_SUPPORTED + png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr, + error_fn, warn_fn, NULL, NULL, NULL); +#else + return png_create_read_struct_2(user_png_ver, error_ptr, error_fn, + warn_fn, NULL, NULL, NULL); +} + +/* Alternate create PNG structure for reading, and allocate any memory + * needed. + */ +PNG_FUNCTION(png_structp,PNGAPI +png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, + png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) +{ + png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr, + error_fn, warn_fn, mem_ptr, malloc_fn, free_fn); +#endif /* USER_MEM */ + + if (png_ptr != NULL) + { + png_ptr->mode = PNG_IS_READ_STRUCT; + + /* Added in libpng-1.6.0; this can be used to detect a read structure if + * required (it will be zero in a write structure.) + */ +# ifdef PNG_SEQUENTIAL_READ_SUPPORTED + png_ptr->IDAT_read_size = PNG_IDAT_READ_SIZE; +# endif + +# ifdef PNG_BENIGN_READ_ERRORS_SUPPORTED + png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN; + + /* In stable builds only warn if an application error can be completely + * handled. + */ +# if PNG_RELEASE_BUILD + png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN; +# endif +# endif + + /* TODO: delay this, it can be done in png_init_io (if the app doesn't + * do it itself) avoiding setting the default function if it is not + * required. + */ + png_set_read_fn(png_ptr, NULL, NULL); + } + + return png_ptr; +} + + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the information before the actual image data. This has been + * changed in v0.90 to allow reading a file that already has the magic + * bytes read from the stream. You can tell libpng how many bytes have + * been read from the beginning of the stream (up to the maximum of 8) + * via png_set_sig_bytes(), and we will only check the remaining bytes + * here. The application can then have access to the signature bytes we + * read if it is determined that this isn't a valid PNG file. + */ +void PNGAPI +png_read_info(png_structrp png_ptr, png_inforp info_ptr) +{ +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + int keep; +#endif + + png_debug(1, "in png_read_info"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + /* Read and check the PNG file signature. */ + png_read_sig(png_ptr, info_ptr); + + for (;;) + { + png_uint_32 length = png_read_chunk_header(png_ptr); + png_uint_32 chunk_name = png_ptr->chunk_name; + + /* IDAT logic needs to happen here to simplify getting the two flags + * right. + */ + if (chunk_name == png_IDAT) + { + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "Missing IHDR before IDAT"); + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + (png_ptr->mode & PNG_HAVE_PLTE) == 0) + png_chunk_error(png_ptr, "Missing PLTE before IDAT"); + + else if ((png_ptr->mode & PNG_AFTER_IDAT) != 0) + png_chunk_benign_error(png_ptr, "Too many IDATs found"); + + png_ptr->mode |= PNG_HAVE_IDAT; + } + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; + png_ptr->mode |= PNG_AFTER_IDAT; + } + + /* This should be a binary subdivision search or a hash for + * matching the chunk name rather than a linear search. + */ + if (chunk_name == png_IHDR) + png_handle_IHDR(png_ptr, info_ptr, length); + + else if (chunk_name == png_IEND) + png_handle_IEND(png_ptr, info_ptr, length); + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) + { + png_handle_unknown(png_ptr, info_ptr, length, keep); + + if (chunk_name == png_PLTE) + png_ptr->mode |= PNG_HAVE_PLTE; + + else if (chunk_name == png_IDAT) + { + png_ptr->idat_size = 0; /* It has been consumed */ + break; + } + } +#endif + else if (chunk_name == png_PLTE) + png_handle_PLTE(png_ptr, info_ptr, length); + + else if (chunk_name == png_IDAT) + { +#ifdef PNG_READ_APNG_SUPPORTED + png_have_info(png_ptr, info_ptr); +#endif + png_ptr->idat_size = length; + break; + } + +#ifdef PNG_READ_bKGD_SUPPORTED + else if (chunk_name == png_bKGD) + png_handle_bKGD(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED + else if (chunk_name == png_cHRM) + png_handle_cHRM(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_eXIf_SUPPORTED + else if (chunk_name == png_eXIf) + png_handle_eXIf(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_gAMA_SUPPORTED + else if (chunk_name == png_gAMA) + png_handle_gAMA(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_hIST_SUPPORTED + else if (chunk_name == png_hIST) + png_handle_hIST(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED + else if (chunk_name == png_oFFs) + png_handle_oFFs(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED + else if (chunk_name == png_pCAL) + png_handle_pCAL(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED + else if (chunk_name == png_sCAL) + png_handle_sCAL(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED + else if (chunk_name == png_pHYs) + png_handle_pHYs(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED + else if (chunk_name == png_sBIT) + png_handle_sBIT(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sRGB_SUPPORTED + else if (chunk_name == png_sRGB) + png_handle_sRGB(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_iCCP_SUPPORTED + else if (chunk_name == png_iCCP) + png_handle_iCCP(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sPLT_SUPPORTED + else if (chunk_name == png_sPLT) + png_handle_sPLT(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED + else if (chunk_name == png_tEXt) + png_handle_tEXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tIME_SUPPORTED + else if (chunk_name == png_tIME) + png_handle_tIME(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tRNS_SUPPORTED + else if (chunk_name == png_tRNS) + png_handle_tRNS(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED + else if (chunk_name == png_zTXt) + png_handle_zTXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_iTXt_SUPPORTED + else if (chunk_name == png_iTXt) + png_handle_iTXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_APNG_SUPPORTED + else if (chunk_name == png_acTL) + png_handle_acTL(png_ptr, info_ptr, length); + + else if (chunk_name == png_fcTL) + png_handle_fcTL(png_ptr, info_ptr, length); + + else if (chunk_name == png_fdAT) + png_handle_fdAT(png_ptr, info_ptr, length); +#endif + + else + png_handle_unknown(png_ptr, info_ptr, length, + PNG_HANDLE_CHUNK_AS_DEFAULT); + } +} +#endif /* SEQUENTIAL_READ */ + +#ifdef PNG_READ_APNG_SUPPORTED +void PNGAPI +png_read_frame_head(png_structp png_ptr, png_infop info_ptr) +{ + png_byte have_chunk_after_DAT; /* after IDAT or after fdAT */ + + png_debug(0, "Reading frame head"); + + if ((png_ptr->mode & PNG_HAVE_acTL) == 0) + png_error(png_ptr, "attempt to png_read_frame_head() but " + "no acTL present"); + + /* do nothing for the main IDAT */ + if (png_ptr->num_frames_read == 0) + return; + + png_read_reset(png_ptr); + png_ptr->flags &= ~PNG_FLAG_ROW_INIT; + png_ptr->mode &= ~PNG_HAVE_fcTL; + + have_chunk_after_DAT = 0; + for (;;) + { + png_uint_32 length = png_read_chunk_header(png_ptr); + + if (png_ptr->chunk_name == png_IDAT) + { + /* discard trailing IDATs for the first frame */ + if (have_chunk_after_DAT != 0 || png_ptr->num_frames_read > 1) + png_error(png_ptr, "png_read_frame_head(): out of place IDAT"); + png_crc_finish(png_ptr, length); + } + + else if (png_ptr->chunk_name == png_fcTL) + { + png_handle_fcTL(png_ptr, info_ptr, length); + have_chunk_after_DAT = 1; + } + + else if (png_ptr->chunk_name == png_fdAT) + { + png_ensure_sequence_number(png_ptr, length); + + /* discard trailing fdATs for frames other than the first */ + if (have_chunk_after_DAT == 0 && png_ptr->num_frames_read > 1) + png_crc_finish(png_ptr, length - 4); + else if (png_ptr->mode & PNG_HAVE_fcTL) + { + png_ptr->idat_size = length - 4; + png_ptr->mode |= PNG_HAVE_IDAT; + + break; + } + else + png_error(png_ptr, "png_read_frame_head(): out of place fdAT"); + } + else + { + png_warning(png_ptr, "Skipped (ignored) a chunk " + "between APNG chunks"); + png_crc_finish(png_ptr, length); + } + } +} +#endif /* READ_APNG */ + +/* Optional call to update the users info_ptr structure */ +void PNGAPI +png_read_update_info(png_structrp png_ptr, png_inforp info_ptr) +{ + png_debug(1, "in png_read_update_info"); + + if (png_ptr != NULL) + { + if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) + { + png_read_start_row(png_ptr); + +# ifdef PNG_READ_TRANSFORMS_SUPPORTED + png_read_transform_info(png_ptr, info_ptr); +# else + PNG_UNUSED(info_ptr) +# endif + } + + /* New in 1.6.0 this avoids the bug of doing the initializations twice */ + else + png_app_error(png_ptr, + "png_read_update_info/png_start_read_image: duplicate call"); + } +} + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Initialize palette, background, etc, after transformations + * are set, but before any reading takes place. This allows + * the user to obtain a gamma-corrected palette, for example. + * If the user doesn't call this, we will do it ourselves. + */ +void PNGAPI +png_start_read_image(png_structrp png_ptr) +{ + png_debug(1, "in png_start_read_image"); + + if (png_ptr != NULL) + { + if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) + png_read_start_row(png_ptr); + + /* New in 1.6.0 this avoids the bug of doing the initializations twice */ + else + png_app_error(png_ptr, + "png_start_read_image/png_read_update_info: duplicate call"); + } +} +#endif /* SEQUENTIAL_READ */ + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +#ifdef PNG_MNG_FEATURES_SUPPORTED +/* Undoes intrapixel differencing, + * NOTE: this is apparently only supported in the 'sequential' reader. + */ +static void +png_do_read_intrapixel(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_read_intrapixel"); + + if ( + (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + int bytes_per_pixel; + png_uint_32 row_width = row_info->width; + + if (row_info->bit_depth == 8) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 3; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 4; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + *(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff); + *(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff); + } + } + else if (row_info->bit_depth == 16) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 6; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 8; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + png_uint_32 s0 = (png_uint_32)(*(rp ) << 8) | *(rp + 1); + png_uint_32 s1 = (png_uint_32)(*(rp + 2) << 8) | *(rp + 3); + png_uint_32 s2 = (png_uint_32)(*(rp + 4) << 8) | *(rp + 5); + png_uint_32 red = (s0 + s1 + 65536) & 0xffff; + png_uint_32 blue = (s2 + s1 + 65536) & 0xffff; + *(rp ) = (png_byte)((red >> 8) & 0xff); + *(rp + 1) = (png_byte)(red & 0xff); + *(rp + 4) = (png_byte)((blue >> 8) & 0xff); + *(rp + 5) = (png_byte)(blue & 0xff); + } + } + } +} +#endif /* MNG_FEATURES */ + +void PNGAPI +png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row) +{ + png_row_info row_info; + + if (png_ptr == NULL) + return; + + png_debug2(1, "in png_read_row (row %lu, pass %d)", + (unsigned long)png_ptr->row_number, png_ptr->pass); + + /* png_read_start_row sets the information (in particular iwidth) for this + * interlace pass. + */ + if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) + png_read_start_row(png_ptr); + + /* 1.5.6: row_info moved out of png_struct to a local here. */ + row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */ + row_info.color_type = png_ptr->color_type; + row_info.bit_depth = png_ptr->bit_depth; + row_info.channels = png_ptr->channels; + row_info.pixel_depth = png_ptr->pixel_depth; + row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); + +#ifdef PNG_WARNINGS_SUPPORTED + if (png_ptr->row_number == 0 && png_ptr->pass == 0) + { + /* Check for transforms that have been set but were defined out */ +#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED) + if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) + png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED) + if ((png_ptr->transformations & PNG_FILLER) != 0) + png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \ + !defined(PNG_READ_PACKSWAP_SUPPORTED) + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) + png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED) + if ((png_ptr->transformations & PNG_PACK) != 0) + png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) + if ((png_ptr->transformations & PNG_SHIFT) != 0) + png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED) + if ((png_ptr->transformations & PNG_BGR) != 0) + png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED) + if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) + png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined"); +#endif + } +#endif /* WARNINGS */ + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* If interlaced and we do not need a new row, combine row and return. + * Notice that the pixels we have from previous rows have been transformed + * already; we can only combine like with like (transformed or + * untransformed) and, because of the libpng API for interlaced images, this + * means we must transform before de-interlacing. + */ + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) != 0) + { + switch (png_ptr->pass) + { + case 0: + if (png_ptr->row_number & 0x07) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + png_read_finish_row(png_ptr); + return; + } + break; + + case 1: + if ((png_ptr->row_number & 0x07) || png_ptr->width < 5) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + + png_read_finish_row(png_ptr); + return; + } + break; + + case 2: + if ((png_ptr->row_number & 0x07) != 4) + { + if (dsp_row != NULL && (png_ptr->row_number & 4)) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + + png_read_finish_row(png_ptr); + return; + } + break; + + case 3: + if ((png_ptr->row_number & 3) || png_ptr->width < 3) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + + png_read_finish_row(png_ptr); + return; + } + break; + + case 4: + if ((png_ptr->row_number & 3) != 2) + { + if (dsp_row != NULL && (png_ptr->row_number & 2)) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + + png_read_finish_row(png_ptr); + return; + } + break; + + case 5: + if ((png_ptr->row_number & 1) || png_ptr->width < 2) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + + png_read_finish_row(png_ptr); + return; + } + break; + + default: + case 6: + if ((png_ptr->row_number & 1) == 0) + { + png_read_finish_row(png_ptr); + return; + } + break; + } + } +#endif + + if ((png_ptr->mode & PNG_HAVE_IDAT) == 0) + png_error(png_ptr, "Invalid attempt to read row data"); + + /* Fill the row with IDAT data: */ + png_ptr->row_buf[0]=255; /* to force error if no data was found */ + png_read_IDAT_data(png_ptr, png_ptr->row_buf, row_info.rowbytes + 1); + + if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE) + { + if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST) + png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1, + png_ptr->prev_row + 1, png_ptr->row_buf[0]); + else + png_error(png_ptr, "bad adaptive filter value"); + } + + /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before + * 1.5.6, while the buffer really is this big in current versions of libpng + * it may not be in the future, so this was changed just to copy the + * interlaced count: + */ + memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1); + +#ifdef PNG_MNG_FEATURES_SUPPORTED + if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && + (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) + { + /* Intrapixel differencing */ + png_do_read_intrapixel(&row_info, png_ptr->row_buf + 1); + } +#endif + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + if (png_ptr->transformations) + png_do_read_transformations(png_ptr, &row_info); +#endif + + /* The transformed pixel depth should match the depth now in row_info. */ + if (png_ptr->transformed_pixel_depth == 0) + { + png_ptr->transformed_pixel_depth = row_info.pixel_depth; + if (row_info.pixel_depth > png_ptr->maximum_pixel_depth) + png_error(png_ptr, "sequential row overflow"); + } + + else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth) + png_error(png_ptr, "internal sequential row size calculation error"); + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Expand interlaced rows to full size */ + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) != 0) + { + if (png_ptr->pass < 6) + png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass, + png_ptr->transformations); + + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + + if (row != NULL) + png_combine_row(png_ptr, row, 0/*row*/); + } + + else +#endif + { + if (row != NULL) + png_combine_row(png_ptr, row, -1/*ignored*/); + + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, -1/*ignored*/); + } + png_read_finish_row(png_ptr); + + if (png_ptr->read_row_fn != NULL) + (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); + +} +#endif /* SEQUENTIAL_READ */ + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read one or more rows of image data. If the image is interlaced, + * and png_set_interlace_handling() has been called, the rows need to + * contain the contents of the rows from the previous pass. If the + * image has alpha or transparency, and png_handle_alpha()[*] has been + * called, the rows contents must be initialized to the contents of the + * screen. + * + * "row" holds the actual image, and pixels are placed in it + * as they arrive. If the image is displayed after each pass, it will + * appear to "sparkle" in. "display_row" can be used to display a + * "chunky" progressive image, with finer detail added as it becomes + * available. If you do not want this "chunky" display, you may pass + * NULL for display_row. If you do not want the sparkle display, and + * you have not called png_handle_alpha(), you may pass NULL for rows. + * If you have called png_handle_alpha(), and the image has either an + * alpha channel or a transparency chunk, you must provide a buffer for + * rows. In this case, you do not have to provide a display_row buffer + * also, but you may. If the image is not interlaced, or if you have + * not called png_set_interlace_handling(), the display_row buffer will + * be ignored, so pass NULL to it. + * + * [*] png_handle_alpha() does not exist yet, as of this version of libpng + */ + +void PNGAPI +png_read_rows(png_structrp png_ptr, png_bytepp row, + png_bytepp display_row, png_uint_32 num_rows) +{ + png_uint_32 i; + png_bytepp rp; + png_bytepp dp; + + png_debug(1, "in png_read_rows"); + + if (png_ptr == NULL) + return; + + rp = row; + dp = display_row; + if (rp != NULL && dp != NULL) + for (i = 0; i < num_rows; i++) + { + png_bytep rptr = *rp++; + png_bytep dptr = *dp++; + + png_read_row(png_ptr, rptr, dptr); + } + + else if (rp != NULL) + for (i = 0; i < num_rows; i++) + { + png_bytep rptr = *rp; + png_read_row(png_ptr, rptr, NULL); + rp++; + } + + else if (dp != NULL) + for (i = 0; i < num_rows; i++) + { + png_bytep dptr = *dp; + png_read_row(png_ptr, NULL, dptr); + dp++; + } +} +#endif /* SEQUENTIAL_READ */ + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the entire image. If the image has an alpha channel or a tRNS + * chunk, and you have called png_handle_alpha()[*], you will need to + * initialize the image to the current image that PNG will be overlaying. + * We set the num_rows again here, in case it was incorrectly set in + * png_read_start_row() by a call to png_read_update_info() or + * png_start_read_image() if png_set_interlace_handling() wasn't called + * prior to either of these functions like it should have been. You can + * only call this function once. If you desire to have an image for + * each pass of a interlaced image, use png_read_rows() instead. + * + * [*] png_handle_alpha() does not exist yet, as of this version of libpng + */ +void PNGAPI +png_read_image(png_structrp png_ptr, png_bytepp image) +{ + png_uint_32 i, image_height; + int pass, j; + png_bytepp rp; + + png_debug(1, "in png_read_image"); + + if (png_ptr == NULL) + return; + +#ifdef PNG_READ_INTERLACING_SUPPORTED + if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) + { + pass = png_set_interlace_handling(png_ptr); + /* And make sure transforms are initialized. */ + png_start_read_image(png_ptr); + } + else + { + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) == 0) + { + /* Caller called png_start_read_image or png_read_update_info without + * first turning on the PNG_INTERLACE transform. We can fix this here, + * but the caller should do it! + */ + png_warning(png_ptr, "Interlace handling should be turned on when " + "using png_read_image"); + /* Make sure this is set correctly */ + png_ptr->num_rows = png_ptr->height; + } + + /* Obtain the pass number, which also turns on the PNG_INTERLACE flag in + * the above error case. + */ + pass = png_set_interlace_handling(png_ptr); + } +#else + if (png_ptr->interlaced) + png_error(png_ptr, + "Cannot read interlaced image -- interlace handler disabled"); + + pass = 1; +#endif + + image_height=png_ptr->height; + + for (j = 0; j < pass; j++) + { + rp = image; + for (i = 0; i < image_height; i++) + { + png_read_row(png_ptr, *rp, NULL); + rp++; + } + } +} +#endif /* SEQUENTIAL_READ */ + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the end of the PNG file. Will not read past the end of the + * file, will verify the end is accurate, and will read any comments + * or time information at the end of the file, if info is not NULL. + */ +void PNGAPI +png_read_end(png_structrp png_ptr, png_inforp info_ptr) +{ +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + int keep; +#endif + + png_debug(1, "in png_read_end"); + + if (png_ptr == NULL) + return; + + /* If png_read_end is called in the middle of reading the rows there may + * still be pending IDAT data and an owned zstream. Deal with this here. + */ +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + if (png_chunk_unknown_handling(png_ptr, png_IDAT) == 0) +#endif + png_read_finish_IDAT(png_ptr); + +#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Report invalid palette index; added at libng-1.5.10 */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + png_ptr->num_palette_max > png_ptr->num_palette) + png_benign_error(png_ptr, "Read palette index exceeding num_palette"); +#endif + + do + { + png_uint_32 length = png_read_chunk_header(png_ptr); + png_uint_32 chunk_name = png_ptr->chunk_name; + + if (chunk_name != png_IDAT) + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; + + if (chunk_name == png_IEND) + png_handle_IEND(png_ptr, info_ptr, length); + + else if (chunk_name == png_IHDR) + png_handle_IHDR(png_ptr, info_ptr, length); + + else if (info_ptr == NULL) + png_crc_finish(png_ptr, length); + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) + { + if (chunk_name == png_IDAT) + { + if ((length > 0 && !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)) + || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0) + png_benign_error(png_ptr, ".Too many IDATs found"); + } + png_handle_unknown(png_ptr, info_ptr, length, keep); + if (chunk_name == png_PLTE) + png_ptr->mode |= PNG_HAVE_PLTE; + } +#endif + + else if (chunk_name == png_IDAT) + { + /* Zero length IDATs are legal after the last IDAT has been + * read, but not after other chunks have been read. 1.6 does not + * always read all the deflate data; specifically it cannot be relied + * upon to read the Adler32 at the end. If it doesn't ignore IDAT + * chunks which are longer than zero as well: + */ + if ((length > 0 && !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)) + || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0) + png_benign_error(png_ptr, "..Too many IDATs found"); + + png_crc_finish(png_ptr, length); + } + else if (chunk_name == png_PLTE) + png_handle_PLTE(png_ptr, info_ptr, length); + +#ifdef PNG_READ_bKGD_SUPPORTED + else if (chunk_name == png_bKGD) + png_handle_bKGD(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED + else if (chunk_name == png_cHRM) + png_handle_cHRM(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_eXIf_SUPPORTED + else if (chunk_name == png_eXIf) + png_handle_eXIf(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_gAMA_SUPPORTED + else if (chunk_name == png_gAMA) + png_handle_gAMA(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_hIST_SUPPORTED + else if (chunk_name == png_hIST) + png_handle_hIST(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED + else if (chunk_name == png_oFFs) + png_handle_oFFs(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED + else if (chunk_name == png_pCAL) + png_handle_pCAL(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED + else if (chunk_name == png_sCAL) + png_handle_sCAL(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED + else if (chunk_name == png_pHYs) + png_handle_pHYs(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED + else if (chunk_name == png_sBIT) + png_handle_sBIT(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sRGB_SUPPORTED + else if (chunk_name == png_sRGB) + png_handle_sRGB(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_iCCP_SUPPORTED + else if (chunk_name == png_iCCP) + png_handle_iCCP(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sPLT_SUPPORTED + else if (chunk_name == png_sPLT) + png_handle_sPLT(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED + else if (chunk_name == png_tEXt) + png_handle_tEXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tIME_SUPPORTED + else if (chunk_name == png_tIME) + png_handle_tIME(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tRNS_SUPPORTED + else if (chunk_name == png_tRNS) + png_handle_tRNS(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED + else if (chunk_name == png_zTXt) + png_handle_zTXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_iTXt_SUPPORTED + else if (chunk_name == png_iTXt) + png_handle_iTXt(png_ptr, info_ptr, length); +#endif + + else + png_handle_unknown(png_ptr, info_ptr, length, + PNG_HANDLE_CHUNK_AS_DEFAULT); + } while ((png_ptr->mode & PNG_HAVE_IEND) == 0); +} +#endif /* SEQUENTIAL_READ */ + +/* Free all memory used in the read struct */ +static void +png_read_destroy(png_structrp png_ptr) +{ + png_debug(1, "in png_read_destroy"); + +#ifdef PNG_READ_GAMMA_SUPPORTED + png_destroy_gamma_table(png_ptr); +#endif + + png_free(png_ptr, png_ptr->big_row_buf); + png_ptr->big_row_buf = NULL; + png_free(png_ptr, png_ptr->big_prev_row); + png_ptr->big_prev_row = NULL; + png_free(png_ptr, png_ptr->read_buffer); + png_ptr->read_buffer = NULL; + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + png_free(png_ptr, png_ptr->palette_lookup); + png_ptr->palette_lookup = NULL; + png_free(png_ptr, png_ptr->quantize_index); + png_ptr->quantize_index = NULL; +#endif + + if ((png_ptr->free_me & PNG_FREE_PLTE) != 0) + { + png_zfree(png_ptr, png_ptr->palette); + png_ptr->palette = NULL; + } + png_ptr->free_me &= ~PNG_FREE_PLTE; + +#if defined(PNG_tRNS_SUPPORTED) || \ + defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + if ((png_ptr->free_me & PNG_FREE_TRNS) != 0) + { + png_free(png_ptr, png_ptr->trans_alpha); + png_ptr->trans_alpha = NULL; + } + png_ptr->free_me &= ~PNG_FREE_TRNS; +#endif + + inflateEnd(&png_ptr->zstream); + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + png_free(png_ptr, png_ptr->save_buffer); + png_ptr->save_buffer = NULL; +#endif + +#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) && \ + defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) + png_free(png_ptr, png_ptr->unknown_chunk.data); + png_ptr->unknown_chunk.data = NULL; +#endif + +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + png_free(png_ptr, png_ptr->chunk_list); + png_ptr->chunk_list = NULL; +#endif + +#if defined(PNG_READ_EXPAND_SUPPORTED) && \ + defined(PNG_ARM_NEON_IMPLEMENTATION) + png_free(png_ptr, png_ptr->riffled_palette); + png_ptr->riffled_palette = NULL; +#endif + + /* NOTE: the 'setjmp' buffer may still be allocated and the memory and error + * callbacks are still set at this point. They are required to complete the + * destruction of the png_struct itself. + */ +} + +/* Free all memory used by the read */ +void PNGAPI +png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, + png_infopp end_info_ptr_ptr) +{ + png_structrp png_ptr = NULL; + + png_debug(1, "in png_destroy_read_struct"); + + if (png_ptr_ptr != NULL) + png_ptr = *png_ptr_ptr; + + if (png_ptr == NULL) + return; + + /* libpng 1.6.0: use the API to destroy info structs to ensure consistent + * behavior. Prior to 1.6.0 libpng did extra 'info' destruction in this API. + * The extra was, apparently, unnecessary yet this hides memory leak bugs. + */ + png_destroy_info_struct(png_ptr, end_info_ptr_ptr); + png_destroy_info_struct(png_ptr, info_ptr_ptr); + + *png_ptr_ptr = NULL; + png_read_destroy(png_ptr); + png_destroy_png_struct(png_ptr); +} + +void PNGAPI +png_set_read_status_fn(png_structrp png_ptr, png_read_status_ptr read_row_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->read_row_fn = read_row_fn; +} + + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +#ifdef PNG_INFO_IMAGE_SUPPORTED +void PNGAPI +png_read_png(png_structrp png_ptr, png_inforp info_ptr, + int transforms, voidp params) +{ + if (png_ptr == NULL || info_ptr == NULL) + return; + + /* png_read_info() gives us all of the information from the + * PNG file before the first IDAT (image data chunk). + */ + png_read_info(png_ptr, info_ptr); + if (info_ptr->height > PNG_UINT_32_MAX/(sizeof (png_bytep))) + png_error(png_ptr, "Image is too high to process with png_read_png()"); + + /* -------------- image transformations start here ------------------- */ + /* libpng 1.6.10: add code to cause a png_app_error if a selected TRANSFORM + * is not implemented. This will only happen in de-configured (non-default) + * libpng builds. The results can be unexpected - png_read_png may return + * short or mal-formed rows because the transform is skipped. + */ + + /* Tell libpng to strip 16-bit/color files down to 8 bits per color. + */ + if ((transforms & PNG_TRANSFORM_SCALE_16) != 0) + /* Added at libpng-1.5.4. "strip_16" produces the same result that it + * did in earlier versions, while "scale_16" is now more accurate. + */ +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + png_set_scale_16(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SCALE_16 not supported"); +#endif + + /* If both SCALE and STRIP are required pngrtran will effectively cancel the + * latter by doing SCALE first. This is ok and allows apps not to check for + * which is supported to get the right answer. + */ + if ((transforms & PNG_TRANSFORM_STRIP_16) != 0) +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + png_set_strip_16(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_16 not supported"); +#endif + + /* Strip alpha bytes from the input data without combining with + * the background (not recommended). + */ + if ((transforms & PNG_TRANSFORM_STRIP_ALPHA) != 0) +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + png_set_strip_alpha(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_ALPHA not supported"); +#endif + + /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single + * byte into separate bytes (useful for paletted and grayscale images). + */ + if ((transforms & PNG_TRANSFORM_PACKING) != 0) +#ifdef PNG_READ_PACK_SUPPORTED + png_set_packing(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported"); +#endif + + /* Change the order of packed pixels to least significant bit first + * (not useful if you are using png_set_packing). + */ + if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0) +#ifdef PNG_READ_PACKSWAP_SUPPORTED + png_set_packswap(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported"); +#endif + + /* Expand paletted colors into true RGB triplets + * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel + * Expand paletted or RGB images with transparency to full alpha + * channels so the data will be available as RGBA quartets. + */ + if ((transforms & PNG_TRANSFORM_EXPAND) != 0) +#ifdef PNG_READ_EXPAND_SUPPORTED + png_set_expand(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND not supported"); +#endif + + /* We don't handle background color or gamma transformation or quantizing. + */ + + /* Invert monochrome files to have 0 as white and 1 as black + */ + if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0) +#ifdef PNG_READ_INVERT_SUPPORTED + png_set_invert_mono(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported"); +#endif + + /* If you want to shift the pixel values from the range [0,255] or + * [0,65535] to the original [0,7] or [0,31], or whatever range the + * colors were originally in: + */ + if ((transforms & PNG_TRANSFORM_SHIFT) != 0) +#ifdef PNG_READ_SHIFT_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sBIT) != 0) + png_set_shift(png_ptr, &info_ptr->sig_bit); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported"); +#endif + + /* Flip the RGB pixels to BGR (or RGBA to BGRA) */ + if ((transforms & PNG_TRANSFORM_BGR) != 0) +#ifdef PNG_READ_BGR_SUPPORTED + png_set_bgr(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported"); +#endif + + /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */ + if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0) +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED + png_set_swap_alpha(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported"); +#endif + + /* Swap bytes of 16-bit files to least significant byte first */ + if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0) +#ifdef PNG_READ_SWAP_SUPPORTED + png_set_swap(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported"); +#endif + +/* Added at libpng-1.2.41 */ + /* Invert the alpha channel from opacity to transparency */ + if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0) +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED + png_set_invert_alpha(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported"); +#endif + +/* Added at libpng-1.2.41 */ + /* Expand grayscale image to RGB */ + if ((transforms & PNG_TRANSFORM_GRAY_TO_RGB) != 0) +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + png_set_gray_to_rgb(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_GRAY_TO_RGB not supported"); +#endif + +/* Added at libpng-1.5.4 */ + if ((transforms & PNG_TRANSFORM_EXPAND_16) != 0) +#ifdef PNG_READ_EXPAND_16_SUPPORTED + png_set_expand_16(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND_16 not supported"); +#endif + + /* We don't handle adding filler bytes */ + + /* We use png_read_image and rely on that for interlace handling, but we also + * call png_read_update_info therefore must turn on interlace handling now: + */ + (void)png_set_interlace_handling(png_ptr); + + /* Optional call to gamma correct and add the background to the palette + * and update info structure. REQUIRED if you are expecting libpng to + * update the palette for you (i.e., you selected such a transform above). + */ + png_read_update_info(png_ptr, info_ptr); + + /* -------------- image transformations end here ------------------- */ + + png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); + if (info_ptr->row_pointers == NULL) + { + png_uint_32 iptr; + + info_ptr->row_pointers = png_voidcast(png_bytepp, png_malloc(png_ptr, + info_ptr->height * (sizeof (png_bytep)))); + + for (iptr=0; iptr<info_ptr->height; iptr++) + info_ptr->row_pointers[iptr] = NULL; + + info_ptr->free_me |= PNG_FREE_ROWS; + + for (iptr = 0; iptr < info_ptr->height; iptr++) + info_ptr->row_pointers[iptr] = png_voidcast(png_bytep, + png_malloc(png_ptr, info_ptr->rowbytes)); + } + + png_read_image(png_ptr, info_ptr->row_pointers); + info_ptr->valid |= PNG_INFO_IDAT; + + /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */ + png_read_end(png_ptr, info_ptr); + + PNG_UNUSED(params) +} +#endif /* INFO_IMAGE */ +#endif /* SEQUENTIAL_READ */ + +#ifdef PNG_SIMPLIFIED_READ_SUPPORTED +/* SIMPLIFIED READ + * + * This code currently relies on the sequential reader, though it could easily + * be made to work with the progressive one. + */ +/* Arguments to png_image_finish_read: */ + +/* Encoding of PNG data (used by the color-map code) */ +# define P_NOTSET 0 /* File encoding not yet known */ +# define P_sRGB 1 /* 8-bit encoded to sRGB gamma */ +# define P_LINEAR 2 /* 16-bit linear: not encoded, NOT pre-multiplied! */ +# define P_FILE 3 /* 8-bit encoded to file gamma, not sRGB or linear */ +# define P_LINEAR8 4 /* 8-bit linear: only from a file value */ + +/* Color-map processing: after libpng has run on the PNG image further + * processing may be needed to convert the data to color-map indices. + */ +#define PNG_CMAP_NONE 0 +#define PNG_CMAP_GA 1 /* Process GA data to a color-map with alpha */ +#define PNG_CMAP_TRANS 2 /* Process GA data to a background index */ +#define PNG_CMAP_RGB 3 /* Process RGB data */ +#define PNG_CMAP_RGB_ALPHA 4 /* Process RGBA data */ + +/* The following document where the background is for each processing case. */ +#define PNG_CMAP_NONE_BACKGROUND 256 +#define PNG_CMAP_GA_BACKGROUND 231 +#define PNG_CMAP_TRANS_BACKGROUND 254 +#define PNG_CMAP_RGB_BACKGROUND 256 +#define PNG_CMAP_RGB_ALPHA_BACKGROUND 216 + +typedef struct +{ + /* Arguments: */ + png_imagep image; + png_voidp buffer; + png_int_32 row_stride; + png_voidp colormap; + png_const_colorp background; + /* Local variables: */ + png_voidp local_row; + png_voidp first_row; + ptrdiff_t row_bytes; /* step between rows */ + int file_encoding; /* E_ values above */ + png_fixed_point gamma_to_linear; /* For P_FILE, reciprocal of gamma */ + int colormap_processing; /* PNG_CMAP_ values above */ +} png_image_read_control; + +/* Do all the *safe* initialization - 'safe' means that png_error won't be + * called, so setting up the jmp_buf is not required. This means that anything + * called from here must *not* call png_malloc - it has to call png_malloc_warn + * instead so that control is returned safely back to this routine. + */ +static int +png_image_read_init(png_imagep image) +{ + if (image->opaque == NULL) + { + png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, image, + png_safe_error, png_safe_warning); + + /* And set the rest of the structure to NULL to ensure that the various + * fields are consistent. + */ + memset(image, 0, (sizeof *image)); + image->version = PNG_IMAGE_VERSION; + + if (png_ptr != NULL) + { + png_infop info_ptr = png_create_info_struct(png_ptr); + + if (info_ptr != NULL) + { + png_controlp control = png_voidcast(png_controlp, + png_malloc_warn(png_ptr, (sizeof *control))); + + if (control != NULL) + { + memset(control, 0, (sizeof *control)); + + control->png_ptr = png_ptr; + control->info_ptr = info_ptr; + control->for_write = 0; + + image->opaque = control; + return 1; + } + + /* Error clean up */ + png_destroy_info_struct(png_ptr, &info_ptr); + } + + png_destroy_read_struct(&png_ptr, NULL, NULL); + } + + return png_image_error(image, "png_image_read: out of memory"); + } + + return png_image_error(image, "png_image_read: opaque pointer not NULL"); +} + +/* Utility to find the base format of a PNG file from a png_struct. */ +static png_uint_32 +png_image_format(png_structrp png_ptr) +{ + png_uint_32 format = 0; + + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + format |= PNG_FORMAT_FLAG_COLOR; + + if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) + format |= PNG_FORMAT_FLAG_ALPHA; + + /* Use png_ptr here, not info_ptr, because by examination png_handle_tRNS + * sets the png_struct fields; that's all we are interested in here. The + * precise interaction with an app call to png_set_tRNS and PNG file reading + * is unclear. + */ + else if (png_ptr->num_trans > 0) + format |= PNG_FORMAT_FLAG_ALPHA; + + if (png_ptr->bit_depth == 16) + format |= PNG_FORMAT_FLAG_LINEAR; + + if ((png_ptr->color_type & PNG_COLOR_MASK_PALETTE) != 0) + format |= PNG_FORMAT_FLAG_COLORMAP; + + return format; +} + +/* Is the given gamma significantly different from sRGB? The test is the same + * one used in pngrtran.c when deciding whether to do gamma correction. The + * arithmetic optimizes the division by using the fact that the inverse of the + * file sRGB gamma is 2.2 + */ +static int +png_gamma_not_sRGB(png_fixed_point g) +{ + if (g < PNG_FP_1) + { + /* An uninitialized gamma is assumed to be sRGB for the simplified API. */ + if (g == 0) + return 0; + + return png_gamma_significant((g * 11 + 2)/5 /* i.e. *2.2, rounded */); + } + + return 1; +} + +/* Do the main body of a 'png_image_begin_read' function; read the PNG file + * header and fill in all the information. This is executed in a safe context, + * unlike the init routine above. + */ +static int +png_image_read_header(png_voidp argument) +{ + png_imagep image = png_voidcast(png_imagep, argument); + png_structrp png_ptr = image->opaque->png_ptr; + png_inforp info_ptr = image->opaque->info_ptr; + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED + png_set_benign_errors(png_ptr, 1/*warn*/); +#endif + png_read_info(png_ptr, info_ptr); + + /* Do this the fast way; just read directly out of png_struct. */ + image->width = png_ptr->width; + image->height = png_ptr->height; + + { + png_uint_32 format = png_image_format(png_ptr); + + image->format = format; + +#ifdef PNG_COLORSPACE_SUPPORTED + /* Does the colorspace match sRGB? If there is no color endpoint + * (colorant) information assume yes, otherwise require the + * 'ENDPOINTS_MATCHP_sRGB' colorspace flag to have been set. If the + * colorspace has been determined to be invalid ignore it. + */ + if ((format & PNG_FORMAT_FLAG_COLOR) != 0 && ((png_ptr->colorspace.flags + & (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB| + PNG_COLORSPACE_INVALID)) == PNG_COLORSPACE_HAVE_ENDPOINTS)) + image->flags |= PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB; +#endif + } + + /* We need the maximum number of entries regardless of the format the + * application sets here. + */ + { + png_uint_32 cmap_entries; + + switch (png_ptr->color_type) + { + case PNG_COLOR_TYPE_GRAY: + cmap_entries = 1U << png_ptr->bit_depth; + break; + + case PNG_COLOR_TYPE_PALETTE: + cmap_entries = (png_uint_32)png_ptr->num_palette; + break; + + default: + cmap_entries = 256; + break; + } + + if (cmap_entries > 256) + cmap_entries = 256; + + image->colormap_entries = cmap_entries; + } + + return 1; +} + +#ifdef PNG_STDIO_SUPPORTED +int PNGAPI +png_image_begin_read_from_stdio(png_imagep image, FILE* file) +{ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (file != NULL) + { + if (png_image_read_init(image) != 0) + { + /* This is slightly evil, but png_init_io doesn't do anything other + * than this and we haven't changed the standard IO functions so + * this saves a 'safe' function. + */ + image->opaque->png_ptr->io_ptr = file; + return png_safe_execute(image, png_image_read_header, image); + } + } + + else + return png_image_error(image, + "png_image_begin_read_from_stdio: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION"); + + return 0; +} + +int PNGAPI +png_image_begin_read_from_file(png_imagep image, const char *file_name) +{ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (file_name != NULL) + { + FILE *fp = fopen(file_name, "rb"); + + if (fp != NULL) + { + if (png_image_read_init(image) != 0) + { + image->opaque->png_ptr->io_ptr = fp; + image->opaque->owned_file = 1; + return png_safe_execute(image, png_image_read_header, image); + } + + /* Clean up: just the opened file. */ + (void)fclose(fp); + } + + else + return png_image_error(image, strerror(errno)); + } + + else + return png_image_error(image, + "png_image_begin_read_from_file: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION"); + + return 0; +} +#endif /* STDIO */ + +static void PNGCBAPI +png_image_memory_read(png_structp png_ptr, png_bytep out, size_t need) +{ + if (png_ptr != NULL) + { + png_imagep image = png_voidcast(png_imagep, png_ptr->io_ptr); + if (image != NULL) + { + png_controlp cp = image->opaque; + if (cp != NULL) + { + png_const_bytep memory = cp->memory; + size_t size = cp->size; + + if (memory != NULL && size >= need) + { + memcpy(out, memory, need); + cp->memory = memory + need; + cp->size = size - need; + return; + } + + png_error(png_ptr, "read beyond end of data"); + } + } + + png_error(png_ptr, "invalid memory read"); + } +} + +int PNGAPI png_image_begin_read_from_memory(png_imagep image, + png_const_voidp memory, size_t size) +{ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (memory != NULL && size > 0) + { + if (png_image_read_init(image) != 0) + { + /* Now set the IO functions to read from the memory buffer and + * store it into io_ptr. Again do this in-place to avoid calling a + * libpng function that requires error handling. + */ + image->opaque->memory = png_voidcast(png_const_bytep, memory); + image->opaque->size = size; + image->opaque->png_ptr->io_ptr = image; + image->opaque->png_ptr->read_data_fn = png_image_memory_read; + + return png_safe_execute(image, png_image_read_header, image); + } + } + + else + return png_image_error(image, + "png_image_begin_read_from_memory: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION"); + + return 0; +} + +/* Utility function to skip chunks that are not used by the simplified image + * read functions and an appropriate macro to call it. + */ +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +static void +png_image_skip_unused_chunks(png_structrp png_ptr) +{ + /* Prepare the reader to ignore all recognized chunks whose data will not + * be used, i.e., all chunks recognized by libpng except for those + * involved in basic image reading: + * + * IHDR, PLTE, IDAT, IEND + * + * Or image data handling: + * + * tRNS, bKGD, gAMA, cHRM, sRGB, [iCCP] and sBIT. + * + * This provides a small performance improvement and eliminates any + * potential vulnerability to security problems in the unused chunks. + * + * At present the iCCP chunk data isn't used, so iCCP chunk can be ignored + * too. This allows the simplified API to be compiled without iCCP support, + * however if the support is there the chunk is still checked to detect + * errors (which are unfortunately quite common.) + */ + { + static const png_byte chunks_to_process[] = { + 98, 75, 71, 68, '\0', /* bKGD */ + 99, 72, 82, 77, '\0', /* cHRM */ + 103, 65, 77, 65, '\0', /* gAMA */ +# ifdef PNG_READ_iCCP_SUPPORTED + 105, 67, 67, 80, '\0', /* iCCP */ +# endif + 115, 66, 73, 84, '\0', /* sBIT */ + 115, 82, 71, 66, '\0', /* sRGB */ + }; + + /* Ignore unknown chunks and all other chunks except for the + * IHDR, PLTE, tRNS, IDAT, and IEND chunks. + */ + png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_NEVER, + NULL, -1); + + /* But do not ignore image data handling chunks */ + png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_AS_DEFAULT, + chunks_to_process, (int)/*SAFE*/(sizeof chunks_to_process)/5); + } +} + +# define PNG_SKIP_CHUNKS(p) png_image_skip_unused_chunks(p) +#else +# define PNG_SKIP_CHUNKS(p) ((void)0) +#endif /* HANDLE_AS_UNKNOWN */ + +/* The following macro gives the exact rounded answer for all values in the + * range 0..255 (it actually divides by 51.2, but the rounding still generates + * the correct numbers 0..5 + */ +#define PNG_DIV51(v8) (((v8) * 5 + 130) >> 8) + +/* Utility functions to make particular color-maps */ +static void +set_file_encoding(png_image_read_control *display) +{ + png_fixed_point g = display->image->opaque->png_ptr->colorspace.gamma; + if (png_gamma_significant(g) != 0) + { + if (png_gamma_not_sRGB(g) != 0) + { + display->file_encoding = P_FILE; + display->gamma_to_linear = png_reciprocal(g); + } + + else + display->file_encoding = P_sRGB; + } + + else + display->file_encoding = P_LINEAR8; +} + +static unsigned int +decode_gamma(png_image_read_control *display, png_uint_32 value, int encoding) +{ + if (encoding == P_FILE) /* double check */ + encoding = display->file_encoding; + + if (encoding == P_NOTSET) /* must be the file encoding */ + { + set_file_encoding(display); + encoding = display->file_encoding; + } + + switch (encoding) + { + case P_FILE: + value = png_gamma_16bit_correct(value*257, display->gamma_to_linear); + break; + + case P_sRGB: + value = png_sRGB_table[value]; + break; + + case P_LINEAR: + break; + + case P_LINEAR8: + value *= 257; + break; + +#ifdef __GNUC__ + default: + png_error(display->image->opaque->png_ptr, + "unexpected encoding (internal error)"); +#endif + } + + return value; +} + +static png_uint_32 +png_colormap_compose(png_image_read_control *display, + png_uint_32 foreground, int foreground_encoding, png_uint_32 alpha, + png_uint_32 background, int encoding) +{ + /* The file value is composed on the background, the background has the given + * encoding and so does the result, the file is encoded with P_FILE and the + * file and alpha are 8-bit values. The (output) encoding will always be + * P_LINEAR or P_sRGB. + */ + png_uint_32 f = decode_gamma(display, foreground, foreground_encoding); + png_uint_32 b = decode_gamma(display, background, encoding); + + /* The alpha is always an 8-bit value (it comes from the palette), the value + * scaled by 255 is what PNG_sRGB_FROM_LINEAR requires. + */ + f = f * alpha + b * (255-alpha); + + if (encoding == P_LINEAR) + { + /* Scale to 65535; divide by 255, approximately (in fact this is extremely + * accurate, it divides by 255.00000005937181414556, with no overflow.) + */ + f *= 257; /* Now scaled by 65535 */ + f += f >> 16; + f = (f+32768) >> 16; + } + + else /* P_sRGB */ + f = PNG_sRGB_FROM_LINEAR(f); + + return f; +} + +/* NOTE: P_LINEAR values to this routine must be 16-bit, but P_FILE values must + * be 8-bit. + */ +static void +png_create_colormap_entry(png_image_read_control *display, + png_uint_32 ip, png_uint_32 red, png_uint_32 green, png_uint_32 blue, + png_uint_32 alpha, int encoding) +{ + png_imagep image = display->image; + int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) != 0 ? + P_LINEAR : P_sRGB; + int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 && + (red != green || green != blue); + + if (ip > 255) + png_error(image->opaque->png_ptr, "color-map index out of range"); + + /* Update the cache with whether the file gamma is significantly different + * from sRGB. + */ + if (encoding == P_FILE) + { + if (display->file_encoding == P_NOTSET) + set_file_encoding(display); + + /* Note that the cached value may be P_FILE too, but if it is then the + * gamma_to_linear member has been set. + */ + encoding = display->file_encoding; + } + + if (encoding == P_FILE) + { + png_fixed_point g = display->gamma_to_linear; + + red = png_gamma_16bit_correct(red*257, g); + green = png_gamma_16bit_correct(green*257, g); + blue = png_gamma_16bit_correct(blue*257, g); + + if (convert_to_Y != 0 || output_encoding == P_LINEAR) + { + alpha *= 257; + encoding = P_LINEAR; + } + + else + { + red = PNG_sRGB_FROM_LINEAR(red * 255); + green = PNG_sRGB_FROM_LINEAR(green * 255); + blue = PNG_sRGB_FROM_LINEAR(blue * 255); + encoding = P_sRGB; + } + } + + else if (encoding == P_LINEAR8) + { + /* This encoding occurs quite frequently in test cases because PngSuite + * includes a gAMA 1.0 chunk with most images. + */ + red *= 257; + green *= 257; + blue *= 257; + alpha *= 257; + encoding = P_LINEAR; + } + + else if (encoding == P_sRGB && + (convert_to_Y != 0 || output_encoding == P_LINEAR)) + { + /* The values are 8-bit sRGB values, but must be converted to 16-bit + * linear. + */ + red = png_sRGB_table[red]; + green = png_sRGB_table[green]; + blue = png_sRGB_table[blue]; + alpha *= 257; + encoding = P_LINEAR; + } + + /* This is set if the color isn't gray but the output is. */ + if (encoding == P_LINEAR) + { + if (convert_to_Y != 0) + { + /* NOTE: these values are copied from png_do_rgb_to_gray */ + png_uint_32 y = (png_uint_32)6968 * red + (png_uint_32)23434 * green + + (png_uint_32)2366 * blue; + + if (output_encoding == P_LINEAR) + y = (y + 16384) >> 15; + + else + { + /* y is scaled by 32768, we need it scaled by 255: */ + y = (y + 128) >> 8; + y *= 255; + y = PNG_sRGB_FROM_LINEAR((y + 64) >> 7); + alpha = PNG_DIV257(alpha); + encoding = P_sRGB; + } + + blue = red = green = y; + } + + else if (output_encoding == P_sRGB) + { + red = PNG_sRGB_FROM_LINEAR(red * 255); + green = PNG_sRGB_FROM_LINEAR(green * 255); + blue = PNG_sRGB_FROM_LINEAR(blue * 255); + alpha = PNG_DIV257(alpha); + encoding = P_sRGB; + } + } + + if (encoding != output_encoding) + png_error(image->opaque->png_ptr, "bad encoding (internal error)"); + + /* Store the value. */ + { +# ifdef PNG_FORMAT_AFIRST_SUPPORTED + int afirst = (image->format & PNG_FORMAT_FLAG_AFIRST) != 0 && + (image->format & PNG_FORMAT_FLAG_ALPHA) != 0; +# else +# define afirst 0 +# endif +# ifdef PNG_FORMAT_BGR_SUPPORTED + int bgr = (image->format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0; +# else +# define bgr 0 +# endif + + if (output_encoding == P_LINEAR) + { + png_uint_16p entry = png_voidcast(png_uint_16p, display->colormap); + + entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format); + + /* The linear 16-bit values must be pre-multiplied by the alpha channel + * value, if less than 65535 (this is, effectively, composite on black + * if the alpha channel is removed.) + */ + switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format)) + { + case 4: + entry[afirst ? 0 : 3] = (png_uint_16)alpha; + /* FALLTHROUGH */ + + case 3: + if (alpha < 65535) + { + if (alpha > 0) + { + blue = (blue * alpha + 32767U)/65535U; + green = (green * alpha + 32767U)/65535U; + red = (red * alpha + 32767U)/65535U; + } + + else + red = green = blue = 0; + } + entry[afirst + (2 ^ bgr)] = (png_uint_16)blue; + entry[afirst + 1] = (png_uint_16)green; + entry[afirst + bgr] = (png_uint_16)red; + break; + + case 2: + entry[1 ^ afirst] = (png_uint_16)alpha; + /* FALLTHROUGH */ + + case 1: + if (alpha < 65535) + { + if (alpha > 0) + green = (green * alpha + 32767U)/65535U; + + else + green = 0; + } + entry[afirst] = (png_uint_16)green; + break; + + default: + break; + } + } + + else /* output encoding is P_sRGB */ + { + png_bytep entry = png_voidcast(png_bytep, display->colormap); + + entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format); + + switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format)) + { + case 4: + entry[afirst ? 0 : 3] = (png_byte)alpha; + /* FALLTHROUGH */ + case 3: + entry[afirst + (2 ^ bgr)] = (png_byte)blue; + entry[afirst + 1] = (png_byte)green; + entry[afirst + bgr] = (png_byte)red; + break; + + case 2: + entry[1 ^ afirst] = (png_byte)alpha; + /* FALLTHROUGH */ + case 1: + entry[afirst] = (png_byte)green; + break; + + default: + break; + } + } + +# ifdef afirst +# undef afirst +# endif +# ifdef bgr +# undef bgr +# endif + } +} + +static int +make_gray_file_colormap(png_image_read_control *display) +{ + unsigned int i; + + for (i=0; i<256; ++i) + png_create_colormap_entry(display, i, i, i, i, 255, P_FILE); + + return (int)i; +} + +static int +make_gray_colormap(png_image_read_control *display) +{ + unsigned int i; + + for (i=0; i<256; ++i) + png_create_colormap_entry(display, i, i, i, i, 255, P_sRGB); + + return (int)i; +} +#define PNG_GRAY_COLORMAP_ENTRIES 256 + +static int +make_ga_colormap(png_image_read_control *display) +{ + unsigned int i, a; + + /* Alpha is retained, the output will be a color-map with entries + * selected by six levels of alpha. One transparent entry, 6 gray + * levels for all the intermediate alpha values, leaving 230 entries + * for the opaque grays. The color-map entries are the six values + * [0..5]*51, the GA processing uses PNG_DIV51(value) to find the + * relevant entry. + * + * if (alpha > 229) // opaque + * { + * // The 231 entries are selected to make the math below work: + * base = 0; + * entry = (231 * gray + 128) >> 8; + * } + * else if (alpha < 26) // transparent + * { + * base = 231; + * entry = 0; + * } + * else // partially opaque + * { + * base = 226 + 6 * PNG_DIV51(alpha); + * entry = PNG_DIV51(gray); + * } + */ + i = 0; + while (i < 231) + { + unsigned int gray = (i * 256 + 115) / 231; + png_create_colormap_entry(display, i++, gray, gray, gray, 255, P_sRGB); + } + + /* 255 is used here for the component values for consistency with the code + * that undoes premultiplication in pngwrite.c. + */ + png_create_colormap_entry(display, i++, 255, 255, 255, 0, P_sRGB); + + for (a=1; a<5; ++a) + { + unsigned int g; + + for (g=0; g<6; ++g) + png_create_colormap_entry(display, i++, g*51, g*51, g*51, a*51, + P_sRGB); + } + + return (int)i; +} + +#define PNG_GA_COLORMAP_ENTRIES 256 + +static int +make_rgb_colormap(png_image_read_control *display) +{ + unsigned int i, r; + + /* Build a 6x6x6 opaque RGB cube */ + for (i=r=0; r<6; ++r) + { + unsigned int g; + + for (g=0; g<6; ++g) + { + unsigned int b; + + for (b=0; b<6; ++b) + png_create_colormap_entry(display, i++, r*51, g*51, b*51, 255, + P_sRGB); + } + } + + return (int)i; +} + +#define PNG_RGB_COLORMAP_ENTRIES 216 + +/* Return a palette index to the above palette given three 8-bit sRGB values. */ +#define PNG_RGB_INDEX(r,g,b) \ + ((png_byte)(6 * (6 * PNG_DIV51(r) + PNG_DIV51(g)) + PNG_DIV51(b))) + +static int +png_image_read_colormap(png_voidp argument) +{ + png_image_read_control *display = + png_voidcast(png_image_read_control*, argument); + png_imagep image = display->image; + + png_structrp png_ptr = image->opaque->png_ptr; + png_uint_32 output_format = image->format; + int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) != 0 ? + P_LINEAR : P_sRGB; + + unsigned int cmap_entries; + unsigned int output_processing; /* Output processing option */ + unsigned int data_encoding = P_NOTSET; /* Encoding libpng must produce */ + + /* Background information; the background color and the index of this color + * in the color-map if it exists (else 256). + */ + unsigned int background_index = 256; + png_uint_32 back_r, back_g, back_b; + + /* Flags to accumulate things that need to be done to the input. */ + int expand_tRNS = 0; + + /* Exclude the NYI feature of compositing onto a color-mapped buffer; it is + * very difficult to do, the results look awful, and it is difficult to see + * what possible use it is because the application can't control the + * color-map. + */ + if (((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0 || + png_ptr->num_trans > 0) /* alpha in input */ && + ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0) /* no alpha in output */) + { + if (output_encoding == P_LINEAR) /* compose on black */ + back_b = back_g = back_r = 0; + + else if (display->background == NULL /* no way to remove it */) + png_error(png_ptr, + "background color must be supplied to remove alpha/transparency"); + + /* Get a copy of the background color (this avoids repeating the checks + * below.) The encoding is 8-bit sRGB or 16-bit linear, depending on the + * output format. + */ + else + { + back_g = display->background->green; + if ((output_format & PNG_FORMAT_FLAG_COLOR) != 0) + { + back_r = display->background->red; + back_b = display->background->blue; + } + else + back_b = back_r = back_g; + } + } + + else if (output_encoding == P_LINEAR) + back_b = back_r = back_g = 65535; + + else + back_b = back_r = back_g = 255; + + /* Default the input file gamma if required - this is necessary because + * libpng assumes that if no gamma information is present the data is in the + * output format, but the simplified API deduces the gamma from the input + * format. + */ + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) == 0) + { + /* Do this directly, not using the png_colorspace functions, to ensure + * that it happens even if the colorspace is invalid (though probably if + * it is the setting will be ignored) Note that the same thing can be + * achieved at the application interface with png_set_gAMA. + */ + if (png_ptr->bit_depth == 16 && + (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0) + png_ptr->colorspace.gamma = PNG_GAMMA_LINEAR; + + else + png_ptr->colorspace.gamma = PNG_GAMMA_sRGB_INVERSE; + + png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; + } + + /* Decide what to do based on the PNG color type of the input data. The + * utility function png_create_colormap_entry deals with most aspects of the + * output transformations; this code works out how to produce bytes of + * color-map entries from the original format. + */ + switch (png_ptr->color_type) + { + case PNG_COLOR_TYPE_GRAY: + if (png_ptr->bit_depth <= 8) + { + /* There at most 256 colors in the output, regardless of + * transparency. + */ + unsigned int step, i, val, trans = 256/*ignore*/, back_alpha = 0; + + cmap_entries = 1U << png_ptr->bit_depth; + if (cmap_entries > image->colormap_entries) + png_error(png_ptr, "gray[8] color-map: too few entries"); + + step = 255 / (cmap_entries - 1); + output_processing = PNG_CMAP_NONE; + + /* If there is a tRNS chunk then this either selects a transparent + * value or, if the output has no alpha, the background color. + */ + if (png_ptr->num_trans > 0) + { + trans = png_ptr->trans_color.gray; + + if ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0) + back_alpha = output_encoding == P_LINEAR ? 65535 : 255; + } + + /* png_create_colormap_entry just takes an RGBA and writes the + * corresponding color-map entry using the format from 'image', + * including the required conversion to sRGB or linear as + * appropriate. The input values are always either sRGB (if the + * gamma correction flag is 0) or 0..255 scaled file encoded values + * (if the function must gamma correct them). + */ + for (i=val=0; i<cmap_entries; ++i, val += step) + { + /* 'i' is a file value. While this will result in duplicated + * entries for 8-bit non-sRGB encoded files it is necessary to + * have non-gamma corrected values to do tRNS handling. + */ + if (i != trans) + png_create_colormap_entry(display, i, val, val, val, 255, + P_FILE/*8-bit with file gamma*/); + + /* Else this entry is transparent. The colors don't matter if + * there is an alpha channel (back_alpha == 0), but it does no + * harm to pass them in; the values are not set above so this + * passes in white. + * + * NOTE: this preserves the full precision of the application + * supplied background color when it is used. + */ + else + png_create_colormap_entry(display, i, back_r, back_g, back_b, + back_alpha, output_encoding); + } + + /* We need libpng to preserve the original encoding. */ + data_encoding = P_FILE; + + /* The rows from libpng, while technically gray values, are now also + * color-map indices; however, they may need to be expanded to 1 + * byte per pixel. This is what png_set_packing does (i.e., it + * unpacks the bit values into bytes.) + */ + if (png_ptr->bit_depth < 8) + png_set_packing(png_ptr); + } + + else /* bit depth is 16 */ + { + /* The 16-bit input values can be converted directly to 8-bit gamma + * encoded values; however, if a tRNS chunk is present 257 color-map + * entries are required. This means that the extra entry requires + * special processing; add an alpha channel, sacrifice gray level + * 254 and convert transparent (alpha==0) entries to that. + * + * Use libpng to chop the data to 8 bits. Convert it to sRGB at the + * same time to minimize quality loss. If a tRNS chunk is present + * this means libpng must handle it too; otherwise it is impossible + * to do the exact match on the 16-bit value. + * + * If the output has no alpha channel *and* the background color is + * gray then it is possible to let libpng handle the substitution by + * ensuring that the corresponding gray level matches the background + * color exactly. + */ + data_encoding = P_sRGB; + + if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "gray[16] color-map: too few entries"); + + cmap_entries = (unsigned int)make_gray_colormap(display); + + if (png_ptr->num_trans > 0) + { + unsigned int back_alpha; + + if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0) + back_alpha = 0; + + else + { + if (back_r == back_g && back_g == back_b) + { + /* Background is gray; no special processing will be + * required. + */ + png_color_16 c; + png_uint_32 gray = back_g; + + if (output_encoding == P_LINEAR) + { + gray = PNG_sRGB_FROM_LINEAR(gray * 255); + + /* And make sure the corresponding palette entry + * matches. + */ + png_create_colormap_entry(display, gray, back_g, back_g, + back_g, 65535, P_LINEAR); + } + + /* The background passed to libpng, however, must be the + * sRGB value. + */ + c.index = 0; /*unused*/ + c.gray = c.red = c.green = c.blue = (png_uint_16)gray; + + /* NOTE: does this work without expanding tRNS to alpha? + * It should be the color->gray case below apparently + * doesn't. + */ + png_set_background_fixed(png_ptr, &c, + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); + + output_processing = PNG_CMAP_NONE; + break; + } +#ifdef __COVERITY__ + /* Coverity claims that output_encoding cannot be 2 (P_LINEAR) + * here. + */ + back_alpha = 255; +#else + back_alpha = output_encoding == P_LINEAR ? 65535 : 255; +#endif + } + + /* output_processing means that the libpng-processed row will be + * 8-bit GA and it has to be processing to single byte color-map + * values. Entry 254 is replaced by either a completely + * transparent entry or by the background color at full + * precision (and the background color is not a simple gray + * level in this case.) + */ + expand_tRNS = 1; + output_processing = PNG_CMAP_TRANS; + background_index = 254; + + /* And set (overwrite) color-map entry 254 to the actual + * background color at full precision. + */ + png_create_colormap_entry(display, 254, back_r, back_g, back_b, + back_alpha, output_encoding); + } + + else + output_processing = PNG_CMAP_NONE; + } + break; + + case PNG_COLOR_TYPE_GRAY_ALPHA: + /* 8-bit or 16-bit PNG with two channels - gray and alpha. A minimum + * of 65536 combinations. If, however, the alpha channel is to be + * removed there are only 256 possibilities if the background is gray. + * (Otherwise there is a subset of the 65536 possibilities defined by + * the triangle between black, white and the background color.) + * + * Reduce 16-bit files to 8-bit and sRGB encode the result. No need to + * worry about tRNS matching - tRNS is ignored if there is an alpha + * channel. + */ + data_encoding = P_sRGB; + + if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "gray+alpha color-map: too few entries"); + + cmap_entries = (unsigned int)make_ga_colormap(display); + + background_index = PNG_CMAP_GA_BACKGROUND; + output_processing = PNG_CMAP_GA; + } + + else /* alpha is removed */ + { + /* Alpha must be removed as the PNG data is processed when the + * background is a color because the G and A channels are + * independent and the vector addition (non-parallel vectors) is a + * 2-D problem. + * + * This can be reduced to the same algorithm as above by making a + * colormap containing gray levels (for the opaque grays), a + * background entry (for a transparent pixel) and a set of four six + * level color values, one set for each intermediate alpha value. + * See the comments in make_ga_colormap for how this works in the + * per-pixel processing. + * + * If the background is gray, however, we only need a 256 entry gray + * level color map. It is sufficient to make the entry generated + * for the background color be exactly the color specified. + */ + if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0 || + (back_r == back_g && back_g == back_b)) + { + /* Background is gray; no special processing will be required. */ + png_color_16 c; + png_uint_32 gray = back_g; + + if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "gray-alpha color-map: too few entries"); + + cmap_entries = (unsigned int)make_gray_colormap(display); + + if (output_encoding == P_LINEAR) + { + gray = PNG_sRGB_FROM_LINEAR(gray * 255); + + /* And make sure the corresponding palette entry matches. */ + png_create_colormap_entry(display, gray, back_g, back_g, + back_g, 65535, P_LINEAR); + } + + /* The background passed to libpng, however, must be the sRGB + * value. + */ + c.index = 0; /*unused*/ + c.gray = c.red = c.green = c.blue = (png_uint_16)gray; + + png_set_background_fixed(png_ptr, &c, + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); + + output_processing = PNG_CMAP_NONE; + } + + else + { + png_uint_32 i, a; + + /* This is the same as png_make_ga_colormap, above, except that + * the entries are all opaque. + */ + if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "ga-alpha color-map: too few entries"); + + i = 0; + while (i < 231) + { + png_uint_32 gray = (i * 256 + 115) / 231; + png_create_colormap_entry(display, i++, gray, gray, gray, + 255, P_sRGB); + } + + /* NOTE: this preserves the full precision of the application + * background color. + */ + background_index = i; + png_create_colormap_entry(display, i++, back_r, back_g, back_b, +#ifdef __COVERITY__ + /* Coverity claims that output_encoding + * cannot be 2 (P_LINEAR) here. + */ 255U, +#else + output_encoding == P_LINEAR ? 65535U : 255U, +#endif + output_encoding); + + /* For non-opaque input composite on the sRGB background - this + * requires inverting the encoding for each component. The input + * is still converted to the sRGB encoding because this is a + * reasonable approximate to the logarithmic curve of human + * visual sensitivity, at least over the narrow range which PNG + * represents. Consequently 'G' is always sRGB encoded, while + * 'A' is linear. We need the linear background colors. + */ + if (output_encoding == P_sRGB) /* else already linear */ + { + /* This may produce a value not exactly matching the + * background, but that's ok because these numbers are only + * used when alpha != 0 + */ + back_r = png_sRGB_table[back_r]; + back_g = png_sRGB_table[back_g]; + back_b = png_sRGB_table[back_b]; + } + + for (a=1; a<5; ++a) + { + unsigned int g; + + /* PNG_sRGB_FROM_LINEAR expects a 16-bit linear value scaled + * by an 8-bit alpha value (0..255). + */ + png_uint_32 alpha = 51 * a; + png_uint_32 back_rx = (255-alpha) * back_r; + png_uint_32 back_gx = (255-alpha) * back_g; + png_uint_32 back_bx = (255-alpha) * back_b; + + for (g=0; g<6; ++g) + { + png_uint_32 gray = png_sRGB_table[g*51] * alpha; + + png_create_colormap_entry(display, i++, + PNG_sRGB_FROM_LINEAR(gray + back_rx), + PNG_sRGB_FROM_LINEAR(gray + back_gx), + PNG_sRGB_FROM_LINEAR(gray + back_bx), 255, P_sRGB); + } + } + + cmap_entries = i; + output_processing = PNG_CMAP_GA; + } + } + break; + + case PNG_COLOR_TYPE_RGB: + case PNG_COLOR_TYPE_RGB_ALPHA: + /* Exclude the case where the output is gray; we can always handle this + * with the cases above. + */ + if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0) + { + /* The color-map will be grayscale, so we may as well convert the + * input RGB values to a simple grayscale and use the grayscale + * code above. + * + * NOTE: calling this apparently damages the recognition of the + * transparent color in background color handling; call + * png_set_tRNS_to_alpha before png_set_background_fixed. + */ + png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, -1, + -1); + data_encoding = P_sRGB; + + /* The output will now be one or two 8-bit gray or gray+alpha + * channels. The more complex case arises when the input has alpha. + */ + if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + png_ptr->num_trans > 0) && + (output_format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + /* Both input and output have an alpha channel, so no background + * processing is required; just map the GA bytes to the right + * color-map entry. + */ + expand_tRNS = 1; + + if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "rgb[ga] color-map: too few entries"); + + cmap_entries = (unsigned int)make_ga_colormap(display); + background_index = PNG_CMAP_GA_BACKGROUND; + output_processing = PNG_CMAP_GA; + } + + else + { + /* Either the input or the output has no alpha channel, so there + * will be no non-opaque pixels in the color-map; it will just be + * grayscale. + */ + if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "rgb[gray] color-map: too few entries"); + + /* Ideally this code would use libpng to do the gamma correction, + * but if an input alpha channel is to be removed we will hit the + * libpng bug in gamma+compose+rgb-to-gray (the double gamma + * correction bug). Fix this by dropping the gamma correction in + * this case and doing it in the palette; this will result in + * duplicate palette entries, but that's better than the + * alternative of double gamma correction. + */ + if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + png_ptr->num_trans > 0) && + png_gamma_not_sRGB(png_ptr->colorspace.gamma) != 0) + { + cmap_entries = (unsigned int)make_gray_file_colormap(display); + data_encoding = P_FILE; + } + + else + cmap_entries = (unsigned int)make_gray_colormap(display); + + /* But if the input has alpha or transparency it must be removed + */ + if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + png_ptr->num_trans > 0) + { + png_color_16 c; + png_uint_32 gray = back_g; + + /* We need to ensure that the application background exists in + * the colormap and that completely transparent pixels map to + * it. Achieve this simply by ensuring that the entry + * selected for the background really is the background color. + */ + if (data_encoding == P_FILE) /* from the fixup above */ + { + /* The app supplied a gray which is in output_encoding, we + * need to convert it to a value of the input (P_FILE) + * encoding then set this palette entry to the required + * output encoding. + */ + if (output_encoding == P_sRGB) + gray = png_sRGB_table[gray]; /* now P_LINEAR */ + + gray = PNG_DIV257(png_gamma_16bit_correct(gray, + png_ptr->colorspace.gamma)); /* now P_FILE */ + + /* And make sure the corresponding palette entry contains + * exactly the required sRGB value. + */ + png_create_colormap_entry(display, gray, back_g, back_g, + back_g, 0/*unused*/, output_encoding); + } + + else if (output_encoding == P_LINEAR) + { + gray = PNG_sRGB_FROM_LINEAR(gray * 255); + + /* And make sure the corresponding palette entry matches. + */ + png_create_colormap_entry(display, gray, back_g, back_g, + back_g, 0/*unused*/, P_LINEAR); + } + + /* The background passed to libpng, however, must be the + * output (normally sRGB) value. + */ + c.index = 0; /*unused*/ + c.gray = c.red = c.green = c.blue = (png_uint_16)gray; + + /* NOTE: the following is apparently a bug in libpng. Without + * it the transparent color recognition in + * png_set_background_fixed seems to go wrong. + */ + expand_tRNS = 1; + png_set_background_fixed(png_ptr, &c, + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); + } + + output_processing = PNG_CMAP_NONE; + } + } + + else /* output is color */ + { + /* We could use png_quantize here so long as there is no transparent + * color or alpha; png_quantize ignores alpha. Easier overall just + * to do it once and using PNG_DIV51 on the 6x6x6 reduced RGB cube. + * Consequently we always want libpng to produce sRGB data. + */ + data_encoding = P_sRGB; + + /* Is there any transparency or alpha? */ + if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + png_ptr->num_trans > 0) + { + /* Is there alpha in the output too? If so all four channels are + * processed into a special RGB cube with alpha support. + */ + if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + png_uint_32 r; + + if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries) + png_error(png_ptr, "rgb+alpha color-map: too few entries"); + + cmap_entries = (unsigned int)make_rgb_colormap(display); + + /* Add a transparent entry. */ + png_create_colormap_entry(display, cmap_entries, 255, 255, + 255, 0, P_sRGB); + + /* This is stored as the background index for the processing + * algorithm. + */ + background_index = cmap_entries++; + + /* Add 27 r,g,b entries each with alpha 0.5. */ + for (r=0; r<256; r = (r << 1) | 0x7f) + { + png_uint_32 g; + + for (g=0; g<256; g = (g << 1) | 0x7f) + { + png_uint_32 b; + + /* This generates components with the values 0, 127 and + * 255 + */ + for (b=0; b<256; b = (b << 1) | 0x7f) + png_create_colormap_entry(display, cmap_entries++, + r, g, b, 128, P_sRGB); + } + } + + expand_tRNS = 1; + output_processing = PNG_CMAP_RGB_ALPHA; + } + + else + { + /* Alpha/transparency must be removed. The background must + * exist in the color map (achieved by setting adding it after + * the 666 color-map). If the standard processing code will + * pick up this entry automatically that's all that is + * required; libpng can be called to do the background + * processing. + */ + unsigned int sample_size = + PNG_IMAGE_SAMPLE_SIZE(output_format); + png_uint_32 r, g, b; /* sRGB background */ + + if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries) + png_error(png_ptr, "rgb-alpha color-map: too few entries"); + + cmap_entries = (unsigned int)make_rgb_colormap(display); + + png_create_colormap_entry(display, cmap_entries, back_r, + back_g, back_b, 0/*unused*/, output_encoding); + + if (output_encoding == P_LINEAR) + { + r = PNG_sRGB_FROM_LINEAR(back_r * 255); + g = PNG_sRGB_FROM_LINEAR(back_g * 255); + b = PNG_sRGB_FROM_LINEAR(back_b * 255); + } + + else + { + r = back_r; + g = back_g; + b = back_g; + } + + /* Compare the newly-created color-map entry with the one the + * PNG_CMAP_RGB algorithm will use. If the two entries don't + * match, add the new one and set this as the background + * index. + */ + if (memcmp((png_const_bytep)display->colormap + + sample_size * cmap_entries, + (png_const_bytep)display->colormap + + sample_size * PNG_RGB_INDEX(r,g,b), + sample_size) != 0) + { + /* The background color must be added. */ + background_index = cmap_entries++; + + /* Add 27 r,g,b entries each with created by composing with + * the background at alpha 0.5. + */ + for (r=0; r<256; r = (r << 1) | 0x7f) + { + for (g=0; g<256; g = (g << 1) | 0x7f) + { + /* This generates components with the values 0, 127 + * and 255 + */ + for (b=0; b<256; b = (b << 1) | 0x7f) + png_create_colormap_entry(display, cmap_entries++, + png_colormap_compose(display, r, P_sRGB, 128, + back_r, output_encoding), + png_colormap_compose(display, g, P_sRGB, 128, + back_g, output_encoding), + png_colormap_compose(display, b, P_sRGB, 128, + back_b, output_encoding), + 0/*unused*/, output_encoding); + } + } + + expand_tRNS = 1; + output_processing = PNG_CMAP_RGB_ALPHA; + } + + else /* background color is in the standard color-map */ + { + png_color_16 c; + + c.index = 0; /*unused*/ + c.red = (png_uint_16)back_r; + c.gray = c.green = (png_uint_16)back_g; + c.blue = (png_uint_16)back_b; + + png_set_background_fixed(png_ptr, &c, + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); + + output_processing = PNG_CMAP_RGB; + } + } + } + + else /* no alpha or transparency in the input */ + { + /* Alpha in the output is irrelevant, simply map the opaque input + * pixels to the 6x6x6 color-map. + */ + if (PNG_RGB_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "rgb color-map: too few entries"); + + cmap_entries = (unsigned int)make_rgb_colormap(display); + output_processing = PNG_CMAP_RGB; + } + } + break; + + case PNG_COLOR_TYPE_PALETTE: + /* It's already got a color-map. It may be necessary to eliminate the + * tRNS entries though. + */ + { + unsigned int num_trans = png_ptr->num_trans; + png_const_bytep trans = num_trans > 0 ? png_ptr->trans_alpha : NULL; + png_const_colorp colormap = png_ptr->palette; + int do_background = trans != NULL && + (output_format & PNG_FORMAT_FLAG_ALPHA) == 0; + unsigned int i; + + /* Just in case: */ + if (trans == NULL) + num_trans = 0; + + output_processing = PNG_CMAP_NONE; + data_encoding = P_FILE; /* Don't change from color-map indices */ + cmap_entries = (unsigned int)png_ptr->num_palette; + if (cmap_entries > 256) + cmap_entries = 256; + + if (cmap_entries > (unsigned int)image->colormap_entries) + png_error(png_ptr, "palette color-map: too few entries"); + + for (i=0; i < cmap_entries; ++i) + { + if (do_background != 0 && i < num_trans && trans[i] < 255) + { + if (trans[i] == 0) + png_create_colormap_entry(display, i, back_r, back_g, + back_b, 0, output_encoding); + + else + { + /* Must compose the PNG file color in the color-map entry + * on the sRGB color in 'back'. + */ + png_create_colormap_entry(display, i, + png_colormap_compose(display, colormap[i].red, + P_FILE, trans[i], back_r, output_encoding), + png_colormap_compose(display, colormap[i].green, + P_FILE, trans[i], back_g, output_encoding), + png_colormap_compose(display, colormap[i].blue, + P_FILE, trans[i], back_b, output_encoding), + output_encoding == P_LINEAR ? trans[i] * 257U : + trans[i], + output_encoding); + } + } + + else + png_create_colormap_entry(display, i, colormap[i].red, + colormap[i].green, colormap[i].blue, + i < num_trans ? trans[i] : 255U, P_FILE/*8-bit*/); + } + + /* The PNG data may have indices packed in fewer than 8 bits, it + * must be expanded if so. + */ + if (png_ptr->bit_depth < 8) + png_set_packing(png_ptr); + } + break; + + default: + png_error(png_ptr, "invalid PNG color type"); + /*NOT REACHED*/ + } + + /* Now deal with the output processing */ + if (expand_tRNS != 0 && png_ptr->num_trans > 0 && + (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0) + png_set_tRNS_to_alpha(png_ptr); + + switch (data_encoding) + { + case P_sRGB: + /* Change to 8-bit sRGB */ + png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, PNG_GAMMA_sRGB); + /* FALLTHROUGH */ + + case P_FILE: + if (png_ptr->bit_depth > 8) + png_set_scale_16(png_ptr); + break; + +#ifdef __GNUC__ + default: + png_error(png_ptr, "bad data option (internal error)"); +#endif + } + + if (cmap_entries > 256 || cmap_entries > image->colormap_entries) + png_error(png_ptr, "color map overflow (BAD internal error)"); + + image->colormap_entries = cmap_entries; + + /* Double check using the recorded background index */ + switch (output_processing) + { + case PNG_CMAP_NONE: + if (background_index != PNG_CMAP_NONE_BACKGROUND) + goto bad_background; + break; + + case PNG_CMAP_GA: + if (background_index != PNG_CMAP_GA_BACKGROUND) + goto bad_background; + break; + + case PNG_CMAP_TRANS: + if (background_index >= cmap_entries || + background_index != PNG_CMAP_TRANS_BACKGROUND) + goto bad_background; + break; + + case PNG_CMAP_RGB: + if (background_index != PNG_CMAP_RGB_BACKGROUND) + goto bad_background; + break; + + case PNG_CMAP_RGB_ALPHA: + if (background_index != PNG_CMAP_RGB_ALPHA_BACKGROUND) + goto bad_background; + break; + + default: + png_error(png_ptr, "bad processing option (internal error)"); + + bad_background: + png_error(png_ptr, "bad background index (internal error)"); + } + + display->colormap_processing = (int)output_processing; + + return 1/*ok*/; +} + +/* The final part of the color-map read called from png_image_finish_read. */ +static int +png_image_read_and_map(png_voidp argument) +{ + png_image_read_control *display = png_voidcast(png_image_read_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + int passes; + + /* Called when the libpng data must be transformed into the color-mapped + * form. There is a local row buffer in display->local and this routine must + * do the interlace handling. + */ + switch (png_ptr->interlaced) + { + case PNG_INTERLACE_NONE: + passes = 1; + break; + + case PNG_INTERLACE_ADAM7: + passes = PNG_INTERLACE_ADAM7_PASSES; + break; + + default: + png_error(png_ptr, "unknown interlace type"); + } + + { + png_uint_32 height = image->height; + png_uint_32 width = image->width; + int proc = display->colormap_processing; + png_bytep first_row = png_voidcast(png_bytep, display->first_row); + ptrdiff_t step_row = display->row_bytes; + int pass; + + for (pass = 0; pass < passes; ++pass) + { + unsigned int startx, stepx, stepy; + png_uint_32 y; + + if (png_ptr->interlaced == PNG_INTERLACE_ADAM7) + { + /* The row may be empty for a short image: */ + if (PNG_PASS_COLS(width, pass) == 0) + continue; + + startx = PNG_PASS_START_COL(pass); + stepx = PNG_PASS_COL_OFFSET(pass); + y = PNG_PASS_START_ROW(pass); + stepy = PNG_PASS_ROW_OFFSET(pass); + } + + else + { + y = 0; + startx = 0; + stepx = stepy = 1; + } + + for (; y<height; y += stepy) + { + png_bytep inrow = png_voidcast(png_bytep, display->local_row); + png_bytep outrow = first_row + y * step_row; + png_const_bytep end_row = outrow + width; + + /* Read read the libpng data into the temporary buffer. */ + png_read_row(png_ptr, inrow, NULL); + + /* Now process the row according to the processing option, note + * that the caller verifies that the format of the libpng output + * data is as required. + */ + outrow += startx; + switch (proc) + { + case PNG_CMAP_GA: + for (; outrow < end_row; outrow += stepx) + { + /* The data is always in the PNG order */ + unsigned int gray = *inrow++; + unsigned int alpha = *inrow++; + unsigned int entry; + + /* NOTE: this code is copied as a comment in + * make_ga_colormap above. Please update the + * comment if you change this code! + */ + if (alpha > 229) /* opaque */ + { + entry = (231 * gray + 128) >> 8; + } + else if (alpha < 26) /* transparent */ + { + entry = 231; + } + else /* partially opaque */ + { + entry = 226 + 6 * PNG_DIV51(alpha) + PNG_DIV51(gray); + } + + *outrow = (png_byte)entry; + } + break; + + case PNG_CMAP_TRANS: + for (; outrow < end_row; outrow += stepx) + { + png_byte gray = *inrow++; + png_byte alpha = *inrow++; + + if (alpha == 0) + *outrow = PNG_CMAP_TRANS_BACKGROUND; + + else if (gray != PNG_CMAP_TRANS_BACKGROUND) + *outrow = gray; + + else + *outrow = (png_byte)(PNG_CMAP_TRANS_BACKGROUND+1); + } + break; + + case PNG_CMAP_RGB: + for (; outrow < end_row; outrow += stepx) + { + *outrow = PNG_RGB_INDEX(inrow[0], inrow[1], inrow[2]); + inrow += 3; + } + break; + + case PNG_CMAP_RGB_ALPHA: + for (; outrow < end_row; outrow += stepx) + { + unsigned int alpha = inrow[3]; + + /* Because the alpha entries only hold alpha==0.5 values + * split the processing at alpha==0.25 (64) and 0.75 + * (196). + */ + + if (alpha >= 196) + *outrow = PNG_RGB_INDEX(inrow[0], inrow[1], + inrow[2]); + + else if (alpha < 64) + *outrow = PNG_CMAP_RGB_ALPHA_BACKGROUND; + + else + { + /* Likewise there are three entries for each of r, g + * and b. We could select the entry by popcount on + * the top two bits on those architectures that + * support it, this is what the code below does, + * crudely. + */ + unsigned int back_i = PNG_CMAP_RGB_ALPHA_BACKGROUND+1; + + /* Here are how the values map: + * + * 0x00 .. 0x3f -> 0 + * 0x40 .. 0xbf -> 1 + * 0xc0 .. 0xff -> 2 + * + * So, as above with the explicit alpha checks, the + * breakpoints are at 64 and 196. + */ + if (inrow[0] & 0x80) back_i += 9; /* red */ + if (inrow[0] & 0x40) back_i += 9; + if (inrow[0] & 0x80) back_i += 3; /* green */ + if (inrow[0] & 0x40) back_i += 3; + if (inrow[0] & 0x80) back_i += 1; /* blue */ + if (inrow[0] & 0x40) back_i += 1; + + *outrow = (png_byte)back_i; + } + + inrow += 4; + } + break; + + default: + break; + } + } + } + } + + return 1; +} + +static int +png_image_read_colormapped(png_voidp argument) +{ + png_image_read_control *display = png_voidcast(png_image_read_control*, + argument); + png_imagep image = display->image; + png_controlp control = image->opaque; + png_structrp png_ptr = control->png_ptr; + png_inforp info_ptr = control->info_ptr; + + int passes = 0; /* As a flag */ + + PNG_SKIP_CHUNKS(png_ptr); + + /* Update the 'info' structure and make sure the result is as required; first + * make sure to turn on the interlace handling if it will be required + * (because it can't be turned on *after* the call to png_read_update_info!) + */ + if (display->colormap_processing == PNG_CMAP_NONE) + passes = png_set_interlace_handling(png_ptr); + + png_read_update_info(png_ptr, info_ptr); + + /* The expected output can be deduced from the colormap_processing option. */ + switch (display->colormap_processing) + { + case PNG_CMAP_NONE: + /* Output must be one channel and one byte per pixel, the output + * encoding can be anything. + */ + if ((info_ptr->color_type == PNG_COLOR_TYPE_PALETTE || + info_ptr->color_type == PNG_COLOR_TYPE_GRAY) && + info_ptr->bit_depth == 8) + break; + + goto bad_output; + + case PNG_CMAP_TRANS: + case PNG_CMAP_GA: + /* Output must be two channels and the 'G' one must be sRGB, the latter + * can be checked with an exact number because it should have been set + * to this number above! + */ + if (info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && + info_ptr->bit_depth == 8 && + png_ptr->screen_gamma == PNG_GAMMA_sRGB && + image->colormap_entries == 256) + break; + + goto bad_output; + + case PNG_CMAP_RGB: + /* Output must be 8-bit sRGB encoded RGB */ + if (info_ptr->color_type == PNG_COLOR_TYPE_RGB && + info_ptr->bit_depth == 8 && + png_ptr->screen_gamma == PNG_GAMMA_sRGB && + image->colormap_entries == 216) + break; + + goto bad_output; + + case PNG_CMAP_RGB_ALPHA: + /* Output must be 8-bit sRGB encoded RGBA */ + if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA && + info_ptr->bit_depth == 8 && + png_ptr->screen_gamma == PNG_GAMMA_sRGB && + image->colormap_entries == 244 /* 216 + 1 + 27 */) + break; + + goto bad_output; + + default: + bad_output: + png_error(png_ptr, "bad color-map processing (internal error)"); + } + + /* Now read the rows. Do this here if it is possible to read directly into + * the output buffer, otherwise allocate a local row buffer of the maximum + * size libpng requires and call the relevant processing routine safely. + */ + { + png_voidp first_row = display->buffer; + ptrdiff_t row_bytes = display->row_stride; + + /* The following expression is designed to work correctly whether it gives + * a signed or an unsigned result. + */ + if (row_bytes < 0) + { + char *ptr = png_voidcast(char*, first_row); + ptr += (image->height-1) * (-row_bytes); + first_row = png_voidcast(png_voidp, ptr); + } + + display->first_row = first_row; + display->row_bytes = row_bytes; + } + + if (passes == 0) + { + int result; + png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr)); + + display->local_row = row; + result = png_safe_execute(image, png_image_read_and_map, display); + display->local_row = NULL; + png_free(png_ptr, row); + + return result; + } + + else + { + png_alloc_size_t row_bytes = (png_alloc_size_t)display->row_bytes; + + while (--passes >= 0) + { + png_uint_32 y = image->height; + png_bytep row = png_voidcast(png_bytep, display->first_row); + + for (; y > 0; --y) + { + png_read_row(png_ptr, row, NULL); + row += row_bytes; + } + } + + return 1; + } +} + +/* Just the row reading part of png_image_read. */ +static int +png_image_read_composite(png_voidp argument) +{ + png_image_read_control *display = png_voidcast(png_image_read_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + int passes; + + switch (png_ptr->interlaced) + { + case PNG_INTERLACE_NONE: + passes = 1; + break; + + case PNG_INTERLACE_ADAM7: + passes = PNG_INTERLACE_ADAM7_PASSES; + break; + + default: + png_error(png_ptr, "unknown interlace type"); + } + + { + png_uint_32 height = image->height; + png_uint_32 width = image->width; + ptrdiff_t step_row = display->row_bytes; + unsigned int channels = + (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1; + int pass; + + for (pass = 0; pass < passes; ++pass) + { + unsigned int startx, stepx, stepy; + png_uint_32 y; + + if (png_ptr->interlaced == PNG_INTERLACE_ADAM7) + { + /* The row may be empty for a short image: */ + if (PNG_PASS_COLS(width, pass) == 0) + continue; + + startx = PNG_PASS_START_COL(pass) * channels; + stepx = PNG_PASS_COL_OFFSET(pass) * channels; + y = PNG_PASS_START_ROW(pass); + stepy = PNG_PASS_ROW_OFFSET(pass); + } + + else + { + y = 0; + startx = 0; + stepx = channels; + stepy = 1; + } + + for (; y<height; y += stepy) + { + png_bytep inrow = png_voidcast(png_bytep, display->local_row); + png_bytep outrow; + png_const_bytep end_row; + + /* Read the row, which is packed: */ + png_read_row(png_ptr, inrow, NULL); + + outrow = png_voidcast(png_bytep, display->first_row); + outrow += y * step_row; + end_row = outrow + width * channels; + + /* Now do the composition on each pixel in this row. */ + outrow += startx; + for (; outrow < end_row; outrow += stepx) + { + png_byte alpha = inrow[channels]; + + if (alpha > 0) /* else no change to the output */ + { + unsigned int c; + + for (c=0; c<channels; ++c) + { + png_uint_32 component = inrow[c]; + + if (alpha < 255) /* else just use component */ + { + /* This is PNG_OPTIMIZED_ALPHA, the component value + * is a linear 8-bit value. Combine this with the + * current outrow[c] value which is sRGB encoded. + * Arithmetic here is 16-bits to preserve the output + * values correctly. + */ + component *= 257*255; /* =65535 */ + component += (255-alpha)*png_sRGB_table[outrow[c]]; + + /* So 'component' is scaled by 255*65535 and is + * therefore appropriate for the sRGB to linear + * conversion table. + */ + component = PNG_sRGB_FROM_LINEAR(component); + } + + outrow[c] = (png_byte)component; + } + } + + inrow += channels+1; /* components and alpha channel */ + } + } + } + } + + return 1; +} + +/* The do_local_background case; called when all the following transforms are to + * be done: + * + * PNG_RGB_TO_GRAY + * PNG_COMPOSITE + * PNG_GAMMA + * + * This is a work-around for the fact that both the PNG_RGB_TO_GRAY and + * PNG_COMPOSITE code performs gamma correction, so we get double gamma + * correction. The fix-up is to prevent the PNG_COMPOSITE operation from + * happening inside libpng, so this routine sees an 8 or 16-bit gray+alpha + * row and handles the removal or pre-multiplication of the alpha channel. + */ +static int +png_image_read_background(png_voidp argument) +{ + png_image_read_control *display = png_voidcast(png_image_read_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + png_inforp info_ptr = image->opaque->info_ptr; + png_uint_32 height = image->height; + png_uint_32 width = image->width; + int pass, passes; + + /* Double check the convoluted logic below. We expect to get here with + * libpng doing rgb to gray and gamma correction but background processing + * left to the png_image_read_background function. The rows libpng produce + * might be 8 or 16-bit but should always have two channels; gray plus alpha. + */ + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == 0) + png_error(png_ptr, "lost rgb to gray"); + + if ((png_ptr->transformations & PNG_COMPOSE) != 0) + png_error(png_ptr, "unexpected compose"); + + if (png_get_channels(png_ptr, info_ptr) != 2) + png_error(png_ptr, "lost/gained channels"); + + /* Expect the 8-bit case to always remove the alpha channel */ + if ((image->format & PNG_FORMAT_FLAG_LINEAR) == 0 && + (image->format & PNG_FORMAT_FLAG_ALPHA) != 0) + png_error(png_ptr, "unexpected 8-bit transformation"); + + switch (png_ptr->interlaced) + { + case PNG_INTERLACE_NONE: + passes = 1; + break; + + case PNG_INTERLACE_ADAM7: + passes = PNG_INTERLACE_ADAM7_PASSES; + break; + + default: + png_error(png_ptr, "unknown interlace type"); + } + + /* Use direct access to info_ptr here because otherwise the simplified API + * would require PNG_EASY_ACCESS_SUPPORTED (just for this.) Note this is + * checking the value after libpng expansions, not the original value in the + * PNG. + */ + switch (info_ptr->bit_depth) + { + case 8: + /* 8-bit sRGB gray values with an alpha channel; the alpha channel is + * to be removed by composing on a background: either the row if + * display->background is NULL or display->background->green if not. + * Unlike the code above ALPHA_OPTIMIZED has *not* been done. + */ + { + png_bytep first_row = png_voidcast(png_bytep, display->first_row); + ptrdiff_t step_row = display->row_bytes; + + for (pass = 0; pass < passes; ++pass) + { + png_bytep row = png_voidcast(png_bytep, display->first_row); + unsigned int startx, stepx, stepy; + png_uint_32 y; + + if (png_ptr->interlaced == PNG_INTERLACE_ADAM7) + { + /* The row may be empty for a short image: */ + if (PNG_PASS_COLS(width, pass) == 0) + continue; + + startx = PNG_PASS_START_COL(pass); + stepx = PNG_PASS_COL_OFFSET(pass); + y = PNG_PASS_START_ROW(pass); + stepy = PNG_PASS_ROW_OFFSET(pass); + } + + else + { + y = 0; + startx = 0; + stepx = stepy = 1; + } + + if (display->background == NULL) + { + for (; y<height; y += stepy) + { + png_bytep inrow = png_voidcast(png_bytep, + display->local_row); + png_bytep outrow = first_row + y * step_row; + png_const_bytep end_row = outrow + width; + + /* Read the row, which is packed: */ + png_read_row(png_ptr, inrow, NULL); + + /* Now do the composition on each pixel in this row. */ + outrow += startx; + for (; outrow < end_row; outrow += stepx) + { + png_byte alpha = inrow[1]; + + if (alpha > 0) /* else no change to the output */ + { + png_uint_32 component = inrow[0]; + + if (alpha < 255) /* else just use component */ + { + /* Since PNG_OPTIMIZED_ALPHA was not set it is + * necessary to invert the sRGB transfer + * function and multiply the alpha out. + */ + component = png_sRGB_table[component] * alpha; + component += png_sRGB_table[outrow[0]] * + (255-alpha); + component = PNG_sRGB_FROM_LINEAR(component); + } + + outrow[0] = (png_byte)component; + } + + inrow += 2; /* gray and alpha channel */ + } + } + } + + else /* constant background value */ + { + png_byte background8 = display->background->green; + png_uint_16 background = png_sRGB_table[background8]; + + for (; y<height; y += stepy) + { + png_bytep inrow = png_voidcast(png_bytep, + display->local_row); + png_bytep outrow = first_row + y * step_row; + png_const_bytep end_row = outrow + width; + + /* Read the row, which is packed: */ + png_read_row(png_ptr, inrow, NULL); + + /* Now do the composition on each pixel in this row. */ + outrow += startx; + for (; outrow < end_row; outrow += stepx) + { + png_byte alpha = inrow[1]; + + if (alpha > 0) /* else use background */ + { + png_uint_32 component = inrow[0]; + + if (alpha < 255) /* else just use component */ + { + component = png_sRGB_table[component] * alpha; + component += background * (255-alpha); + component = PNG_sRGB_FROM_LINEAR(component); + } + + outrow[0] = (png_byte)component; + } + + else + outrow[0] = background8; + + inrow += 2; /* gray and alpha channel */ + } + + row += display->row_bytes; + } + } + } + } + break; + + case 16: + /* 16-bit linear with pre-multiplied alpha; the pre-multiplication must + * still be done and, maybe, the alpha channel removed. This code also + * handles the alpha-first option. + */ + { + png_uint_16p first_row = png_voidcast(png_uint_16p, + display->first_row); + /* The division by two is safe because the caller passed in a + * stride which was multiplied by 2 (below) to get row_bytes. + */ + ptrdiff_t step_row = display->row_bytes / 2; + unsigned int preserve_alpha = (image->format & + PNG_FORMAT_FLAG_ALPHA) != 0; + unsigned int outchannels = 1U+preserve_alpha; + int swap_alpha = 0; + +# ifdef PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED + if (preserve_alpha != 0 && + (image->format & PNG_FORMAT_FLAG_AFIRST) != 0) + swap_alpha = 1; +# endif + + for (pass = 0; pass < passes; ++pass) + { + unsigned int startx, stepx, stepy; + png_uint_32 y; + + /* The 'x' start and step are adjusted to output components here. + */ + if (png_ptr->interlaced == PNG_INTERLACE_ADAM7) + { + /* The row may be empty for a short image: */ + if (PNG_PASS_COLS(width, pass) == 0) + continue; + + startx = PNG_PASS_START_COL(pass) * outchannels; + stepx = PNG_PASS_COL_OFFSET(pass) * outchannels; + y = PNG_PASS_START_ROW(pass); + stepy = PNG_PASS_ROW_OFFSET(pass); + } + + else + { + y = 0; + startx = 0; + stepx = outchannels; + stepy = 1; + } + + for (; y<height; y += stepy) + { + png_const_uint_16p inrow; + png_uint_16p outrow = first_row + y*step_row; + png_uint_16p end_row = outrow + width * outchannels; + + /* Read the row, which is packed: */ + png_read_row(png_ptr, png_voidcast(png_bytep, + display->local_row), NULL); + inrow = png_voidcast(png_const_uint_16p, display->local_row); + + /* Now do the pre-multiplication on each pixel in this row. + */ + outrow += startx; + for (; outrow < end_row; outrow += stepx) + { + png_uint_32 component = inrow[0]; + png_uint_16 alpha = inrow[1]; + + if (alpha > 0) /* else 0 */ + { + if (alpha < 65535) /* else just use component */ + { + component *= alpha; + component += 32767; + component /= 65535; + } + } + + else + component = 0; + + outrow[swap_alpha] = (png_uint_16)component; + if (preserve_alpha != 0) + outrow[1 ^ swap_alpha] = alpha; + + inrow += 2; /* components and alpha channel */ + } + } + } + } + break; + +#ifdef __GNUC__ + default: + png_error(png_ptr, "unexpected bit depth"); +#endif + } + + return 1; +} + +/* The guts of png_image_finish_read as a png_safe_execute callback. */ +static int +png_image_read_direct(png_voidp argument) +{ + png_image_read_control *display = png_voidcast(png_image_read_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + png_inforp info_ptr = image->opaque->info_ptr; + + png_uint_32 format = image->format; + int linear = (format & PNG_FORMAT_FLAG_LINEAR) != 0; + int do_local_compose = 0; + int do_local_background = 0; /* to avoid double gamma correction bug */ + int passes = 0; + + /* Add transforms to ensure the correct output format is produced then check + * that the required implementation support is there. Always expand; always + * need 8 bits minimum, no palette and expanded tRNS. + */ + png_set_expand(png_ptr); + + /* Now check the format to see if it was modified. */ + { + png_uint_32 base_format = png_image_format(png_ptr) & + ~PNG_FORMAT_FLAG_COLORMAP /* removed by png_set_expand */; + png_uint_32 change = format ^ base_format; + png_fixed_point output_gamma; + int mode; /* alpha mode */ + + /* Do this first so that we have a record if rgb to gray is happening. */ + if ((change & PNG_FORMAT_FLAG_COLOR) != 0) + { + /* gray<->color transformation required. */ + if ((format & PNG_FORMAT_FLAG_COLOR) != 0) + png_set_gray_to_rgb(png_ptr); + + else + { + /* libpng can't do both rgb to gray and + * background/pre-multiplication if there is also significant gamma + * correction, because both operations require linear colors and + * the code only supports one transform doing the gamma correction. + * Handle this by doing the pre-multiplication or background + * operation in this code, if necessary. + * + * TODO: fix this by rewriting pngrtran.c (!) + * + * For the moment (given that fixing this in pngrtran.c is an + * enormous change) 'do_local_background' is used to indicate that + * the problem exists. + */ + if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0) + do_local_background = 1/*maybe*/; + + png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, + PNG_RGB_TO_GRAY_DEFAULT, PNG_RGB_TO_GRAY_DEFAULT); + } + + change &= ~PNG_FORMAT_FLAG_COLOR; + } + + /* Set the gamma appropriately, linear for 16-bit input, sRGB otherwise. + */ + { + png_fixed_point input_gamma_default; + + if ((base_format & PNG_FORMAT_FLAG_LINEAR) != 0 && + (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0) + input_gamma_default = PNG_GAMMA_LINEAR; + else + input_gamma_default = PNG_DEFAULT_sRGB; + + /* Call png_set_alpha_mode to set the default for the input gamma; the + * output gamma is set by a second call below. + */ + png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, input_gamma_default); + } + + if (linear != 0) + { + /* If there *is* an alpha channel in the input it must be multiplied + * out; use PNG_ALPHA_STANDARD, otherwise just use PNG_ALPHA_PNG. + */ + if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0) + mode = PNG_ALPHA_STANDARD; /* associated alpha */ + + else + mode = PNG_ALPHA_PNG; + + output_gamma = PNG_GAMMA_LINEAR; + } + + else + { + mode = PNG_ALPHA_PNG; + output_gamma = PNG_DEFAULT_sRGB; + } + + if ((change & PNG_FORMAT_FLAG_ASSOCIATED_ALPHA) != 0) + { + mode = PNG_ALPHA_OPTIMIZED; + change &= ~PNG_FORMAT_FLAG_ASSOCIATED_ALPHA; + } + + /* If 'do_local_background' is set check for the presence of gamma + * correction; this is part of the work-round for the libpng bug + * described above. + * + * TODO: fix libpng and remove this. + */ + if (do_local_background != 0) + { + png_fixed_point gtest; + + /* This is 'png_gamma_threshold' from pngrtran.c; the test used for + * gamma correction, the screen gamma hasn't been set on png_struct + * yet; it's set below. png_struct::gamma, however, is set to the + * final value. + */ + if (png_muldiv(>est, output_gamma, png_ptr->colorspace.gamma, + PNG_FP_1) != 0 && png_gamma_significant(gtest) == 0) + do_local_background = 0; + + else if (mode == PNG_ALPHA_STANDARD) + { + do_local_background = 2/*required*/; + mode = PNG_ALPHA_PNG; /* prevent libpng doing it */ + } + + /* else leave as 1 for the checks below */ + } + + /* If the bit-depth changes then handle that here. */ + if ((change & PNG_FORMAT_FLAG_LINEAR) != 0) + { + if (linear != 0 /*16-bit output*/) + png_set_expand_16(png_ptr); + + else /* 8-bit output */ + png_set_scale_16(png_ptr); + + change &= ~PNG_FORMAT_FLAG_LINEAR; + } + + /* Now the background/alpha channel changes. */ + if ((change & PNG_FORMAT_FLAG_ALPHA) != 0) + { + /* Removing an alpha channel requires composition for the 8-bit + * formats; for the 16-bit it is already done, above, by the + * pre-multiplication and the channel just needs to be stripped. + */ + if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + /* If RGB->gray is happening the alpha channel must be left and the + * operation completed locally. + * + * TODO: fix libpng and remove this. + */ + if (do_local_background != 0) + do_local_background = 2/*required*/; + + /* 16-bit output: just remove the channel */ + else if (linear != 0) /* compose on black (well, pre-multiply) */ + png_set_strip_alpha(png_ptr); + + /* 8-bit output: do an appropriate compose */ + else if (display->background != NULL) + { + png_color_16 c; + + c.index = 0; /*unused*/ + c.red = display->background->red; + c.green = display->background->green; + c.blue = display->background->blue; + c.gray = display->background->green; + + /* This is always an 8-bit sRGB value, using the 'green' channel + * for gray is much better than calculating the luminance here; + * we can get off-by-one errors in that calculation relative to + * the app expectations and that will show up in transparent + * pixels. + */ + png_set_background_fixed(png_ptr, &c, + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); + } + + else /* compose on row: implemented below. */ + { + do_local_compose = 1; + /* This leaves the alpha channel in the output, so it has to be + * removed by the code below. Set the encoding to the 'OPTIMIZE' + * one so the code only has to hack on the pixels that require + * composition. + */ + mode = PNG_ALPHA_OPTIMIZED; + } + } + + else /* output needs an alpha channel */ + { + /* This is tricky because it happens before the swap operation has + * been accomplished; however, the swap does *not* swap the added + * alpha channel (weird API), so it must be added in the correct + * place. + */ + png_uint_32 filler; /* opaque filler */ + int where; + + if (linear != 0) + filler = 65535; + + else + filler = 255; + +#ifdef PNG_FORMAT_AFIRST_SUPPORTED + if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) + { + where = PNG_FILLER_BEFORE; + change &= ~PNG_FORMAT_FLAG_AFIRST; + } + + else +#endif + where = PNG_FILLER_AFTER; + + png_set_add_alpha(png_ptr, filler, where); + } + + /* This stops the (irrelevant) call to swap_alpha below. */ + change &= ~PNG_FORMAT_FLAG_ALPHA; + } + + /* Now set the alpha mode correctly; this is always done, even if there is + * no alpha channel in either the input or the output because it correctly + * sets the output gamma. + */ + png_set_alpha_mode_fixed(png_ptr, mode, output_gamma); + +# ifdef PNG_FORMAT_BGR_SUPPORTED + if ((change & PNG_FORMAT_FLAG_BGR) != 0) + { + /* Check only the output format; PNG is never BGR; don't do this if + * the output is gray, but fix up the 'format' value in that case. + */ + if ((format & PNG_FORMAT_FLAG_COLOR) != 0) + png_set_bgr(png_ptr); + + else + format &= ~PNG_FORMAT_FLAG_BGR; + + change &= ~PNG_FORMAT_FLAG_BGR; + } +# endif + +# ifdef PNG_FORMAT_AFIRST_SUPPORTED + if ((change & PNG_FORMAT_FLAG_AFIRST) != 0) + { + /* Only relevant if there is an alpha channel - it's particularly + * important to handle this correctly because do_local_compose may + * be set above and then libpng will keep the alpha channel for this + * code to remove. + */ + if ((format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + /* Disable this if doing a local background, + * TODO: remove this when local background is no longer required. + */ + if (do_local_background != 2) + png_set_swap_alpha(png_ptr); + } + + else + format &= ~PNG_FORMAT_FLAG_AFIRST; + + change &= ~PNG_FORMAT_FLAG_AFIRST; + } +# endif + + /* If the *output* is 16-bit then we need to check for a byte-swap on this + * architecture. + */ + if (linear != 0) + { + png_uint_16 le = 0x0001; + + if ((*(png_const_bytep) & le) != 0) + png_set_swap(png_ptr); + } + + /* If change is not now 0 some transformation is missing - error out. */ + if (change != 0) + png_error(png_ptr, "png_read_image: unsupported transformation"); + } + + PNG_SKIP_CHUNKS(png_ptr); + + /* Update the 'info' structure and make sure the result is as required; first + * make sure to turn on the interlace handling if it will be required + * (because it can't be turned on *after* the call to png_read_update_info!) + * + * TODO: remove the do_local_background fixup below. + */ + if (do_local_compose == 0 && do_local_background != 2) + passes = png_set_interlace_handling(png_ptr); + + png_read_update_info(png_ptr, info_ptr); + + { + png_uint_32 info_format = 0; + + if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + info_format |= PNG_FORMAT_FLAG_COLOR; + + if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) + { + /* do_local_compose removes this channel below. */ + if (do_local_compose == 0) + { + /* do_local_background does the same if required. */ + if (do_local_background != 2 || + (format & PNG_FORMAT_FLAG_ALPHA) != 0) + info_format |= PNG_FORMAT_FLAG_ALPHA; + } + } + + else if (do_local_compose != 0) /* internal error */ + png_error(png_ptr, "png_image_read: alpha channel lost"); + + if ((format & PNG_FORMAT_FLAG_ASSOCIATED_ALPHA) != 0) { + info_format |= PNG_FORMAT_FLAG_ASSOCIATED_ALPHA; + } + + if (info_ptr->bit_depth == 16) + info_format |= PNG_FORMAT_FLAG_LINEAR; + +#ifdef PNG_FORMAT_BGR_SUPPORTED + if ((png_ptr->transformations & PNG_BGR) != 0) + info_format |= PNG_FORMAT_FLAG_BGR; +#endif + +#ifdef PNG_FORMAT_AFIRST_SUPPORTED + if (do_local_background == 2) + { + if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) + info_format |= PNG_FORMAT_FLAG_AFIRST; + } + + if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0 || + ((png_ptr->transformations & PNG_ADD_ALPHA) != 0 && + (png_ptr->flags & PNG_FLAG_FILLER_AFTER) == 0)) + { + if (do_local_background == 2) + png_error(png_ptr, "unexpected alpha swap transformation"); + + info_format |= PNG_FORMAT_FLAG_AFIRST; + } +# endif + + /* This is actually an internal error. */ + if (info_format != format) + png_error(png_ptr, "png_read_image: invalid transformations"); + } + + /* Now read the rows. If do_local_compose is set then it is necessary to use + * a local row buffer. The output will be GA, RGBA or BGRA and must be + * converted to G, RGB or BGR as appropriate. The 'local_row' member of the + * display acts as a flag. + */ + { + png_voidp first_row = display->buffer; + ptrdiff_t row_bytes = display->row_stride; + + if (linear != 0) + row_bytes *= 2; + + /* The following expression is designed to work correctly whether it gives + * a signed or an unsigned result. + */ + if (row_bytes < 0) + { + char *ptr = png_voidcast(char*, first_row); + ptr += (image->height-1) * (-row_bytes); + first_row = png_voidcast(png_voidp, ptr); + } + + display->first_row = first_row; + display->row_bytes = row_bytes; + } + + if (do_local_compose != 0) + { + int result; + png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr)); + + display->local_row = row; + result = png_safe_execute(image, png_image_read_composite, display); + display->local_row = NULL; + png_free(png_ptr, row); + + return result; + } + + else if (do_local_background == 2) + { + int result; + png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr)); + + display->local_row = row; + result = png_safe_execute(image, png_image_read_background, display); + display->local_row = NULL; + png_free(png_ptr, row); + + return result; + } + + else + { + png_alloc_size_t row_bytes = (png_alloc_size_t)display->row_bytes; + + while (--passes >= 0) + { + png_uint_32 y = image->height; + png_bytep row = png_voidcast(png_bytep, display->first_row); + + for (; y > 0; --y) + { + png_read_row(png_ptr, row, NULL); + row += row_bytes; + } + } + + return 1; + } +} + +int PNGAPI +png_image_finish_read(png_imagep image, png_const_colorp background, + void *buffer, png_int_32 row_stride, void *colormap) +{ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + /* Check for row_stride overflow. This check is not performed on the + * original PNG format because it may not occur in the output PNG format + * and libpng deals with the issues of reading the original. + */ + unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format); + + /* The following checks just the 'row_stride' calculation to ensure it + * fits in a signed 32-bit value. Because channels/components can be + * either 1 or 2 bytes in size the length of a row can still overflow 32 + * bits; this is just to verify that the 'row_stride' argument can be + * represented. + */ + if (image->width <= 0x7fffffffU/channels) /* no overflow */ + { + png_uint_32 check; + png_uint_32 png_row_stride = image->width * channels; + + if (row_stride == 0) + row_stride = (png_int_32)/*SAFE*/png_row_stride; + + if (row_stride < 0) + check = (png_uint_32)(-row_stride); + + else + check = (png_uint_32)row_stride; + + /* This verifies 'check', the absolute value of the actual stride + * passed in and detects overflow in the application calculation (i.e. + * if the app did actually pass in a non-zero 'row_stride'. + */ + if (image->opaque != NULL && buffer != NULL && check >= png_row_stride) + { + /* Now check for overflow of the image buffer calculation; this + * limits the whole image size to 32 bits for API compatibility with + * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro. + * + * The PNG_IMAGE_BUFFER_SIZE macro is: + * + * (PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)*height*(row_stride)) + * + * And the component size is always 1 or 2, so make sure that the + * number of *bytes* that the application is saying are available + * does actually fit into a 32-bit number. + * + * NOTE: this will be changed in 1.7 because PNG_IMAGE_BUFFER_SIZE + * will be changed to use png_alloc_size_t; bigger images can be + * accommodated on 64-bit systems. + */ + if (image->height <= + 0xffffffffU/PNG_IMAGE_PIXEL_COMPONENT_SIZE(image->format)/check) + { + if ((image->format & PNG_FORMAT_FLAG_COLORMAP) == 0 || + (image->colormap_entries > 0 && colormap != NULL)) + { + int result; + png_image_read_control display; + + memset(&display, 0, (sizeof display)); + display.image = image; + display.buffer = buffer; + display.row_stride = row_stride; + display.colormap = colormap; + display.background = background; + display.local_row = NULL; + + /* Choose the correct 'end' routine; for the color-map case + * all the setup has already been done. + */ + if ((image->format & PNG_FORMAT_FLAG_COLORMAP) != 0) + result = + png_safe_execute(image, + png_image_read_colormap, &display) && + png_safe_execute(image, + png_image_read_colormapped, &display); + + else + result = + png_safe_execute(image, + png_image_read_direct, &display); + + png_image_free(image); + return result; + } + + else + return png_image_error(image, + "png_image_finish_read[color-map]: no color-map"); + } + + else + return png_image_error(image, + "png_image_finish_read: image too large"); + } + + else + return png_image_error(image, + "png_image_finish_read: invalid argument"); + } + + else + return png_image_error(image, + "png_image_finish_read: row_stride too large"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_finish_read: damaged PNG_IMAGE_VERSION"); + + return 0; +} + +#endif /* SIMPLIFIED_READ */ +#endif /* READ */ diff --git a/media/libpng/pngrio.c b/media/libpng/pngrio.c new file mode 100644 index 0000000000..7946358101 --- /dev/null +++ b/media/libpng/pngrio.c @@ -0,0 +1,120 @@ + +/* pngrio.c - functions for data input + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all input. Users who need + * special handling are expected to write a function that has the same + * arguments as this and performs a similar function, but that possibly + * has a different input method. Note that you shouldn't change this + * function, but rather write a replacement function and then make + * libpng use it at run time with png_set_read_fn(...). + */ + +#include "pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +/* Read the data from whatever input you are using. The default routine + * reads from a file pointer. Note that this routine sometimes gets called + * with very small lengths, so you should implement some kind of simple + * buffering if you are using unbuffered reads. This should never be asked + * to read more than 64K on a 16-bit machine. + */ +void /* PRIVATE */ +png_read_data(png_structrp png_ptr, png_bytep data, size_t length) +{ + png_debug1(4, "reading %d bytes", (int)length); + + if (png_ptr->read_data_fn != NULL) + (*(png_ptr->read_data_fn))(png_ptr, data, length); + + else + png_error(png_ptr, "Call to NULL read function"); +} + +#ifdef PNG_STDIO_SUPPORTED +/* This is the function that does the actual reading of data. If you are + * not reading from a standard C stream, you should create a replacement + * read_data function and use it at run time with png_set_read_fn(), rather + * than changing the library. + */ +void PNGCBAPI +png_default_read_data(png_structp png_ptr, png_bytep data, size_t length) +{ + size_t check; + + if (png_ptr == NULL) + return; + + /* fread() returns 0 on error, so it is OK to store this in a size_t + * instead of an int, which is what fread() actually returns. + */ + check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr)); + + if (check != length) + png_error(png_ptr, "Read Error"); +} +#endif + +/* This function allows the application to supply a new input function + * for libpng if standard C streams aren't being used. + * + * This function takes as its arguments: + * + * png_ptr - pointer to a png input data structure + * + * io_ptr - pointer to user supplied structure containing info about + * the input functions. May be NULL. + * + * read_data_fn - pointer to a new input function that takes as its + * arguments a pointer to a png_struct, a pointer to + * a location where input data can be stored, and a 32-bit + * unsigned int that is the number of bytes to be read. + * To exit and output any fatal error messages the new write + * function should call png_error(png_ptr, "Error msg"). + * May be NULL, in which case libpng's default function will + * be used. + */ +void PNGAPI +png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr, + png_rw_ptr read_data_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->io_ptr = io_ptr; + +#ifdef PNG_STDIO_SUPPORTED + if (read_data_fn != NULL) + png_ptr->read_data_fn = read_data_fn; + + else + png_ptr->read_data_fn = png_default_read_data; +#else + png_ptr->read_data_fn = read_data_fn; +#endif + +#ifdef PNG_WRITE_SUPPORTED + /* It is an error to write to a read device */ + if (png_ptr->write_data_fn != NULL) + { + png_ptr->write_data_fn = NULL; + png_warning(png_ptr, + "Can't set both read_data_fn and write_data_fn in the" + " same structure"); + } +#endif + +#ifdef PNG_WRITE_FLUSH_SUPPORTED + png_ptr->output_flush_fn = NULL; +#endif +} +#endif /* READ */ diff --git a/media/libpng/pngrtran.c b/media/libpng/pngrtran.c new file mode 100644 index 0000000000..786e0de5d2 --- /dev/null +++ b/media/libpng/pngrtran.c @@ -0,0 +1,5044 @@ + +/* pngrtran.c - transforms the data in a row for PNG readers + * + * Copyright (c) 2018-2019 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file contains functions optionally called by an application + * in order to tell libpng how to handle data when reading a PNG. + * Transformations that are used in both reading and writing are + * in pngtrans.c. + */ + +#include "pngpriv.h" + +#ifdef PNG_ARM_NEON_IMPLEMENTATION +# if PNG_ARM_NEON_IMPLEMENTATION == 1 +# define PNG_ARM_NEON_INTRINSICS_AVAILABLE +# if defined(_MSC_VER) && defined(_M_ARM64) && !defined(__clang__) +# include <arm64_neon.h> +# else +# include <arm_neon.h> +# endif +# endif +#endif + +#ifdef PNG_READ_SUPPORTED + +/* Set the action on getting a CRC error for an ancillary or critical chunk. */ +void PNGAPI +png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action) +{ + png_debug(1, "in png_set_crc_action"); + + if (png_ptr == NULL) + return; + + /* Tell libpng how we react to CRC errors in critical chunks */ + switch (crit_action) + { + case PNG_CRC_NO_CHANGE: /* Leave setting as is */ + break; + + case PNG_CRC_WARN_USE: /* Warn/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; + break; + + case PNG_CRC_QUIET_USE: /* Quiet/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | + PNG_FLAG_CRC_CRITICAL_IGNORE; + break; + + case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */ + png_warning(png_ptr, + "Can't discard critical data on CRC error"); + /* FALLTHROUGH */ + case PNG_CRC_ERROR_QUIT: /* Error/quit */ + + case PNG_CRC_DEFAULT: + default: + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + break; + } + + /* Tell libpng how we react to CRC errors in ancillary chunks */ + switch (ancil_action) + { + case PNG_CRC_NO_CHANGE: /* Leave setting as is */ + break; + + case PNG_CRC_WARN_USE: /* Warn/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; + break; + + case PNG_CRC_QUIET_USE: /* Quiet/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | + PNG_FLAG_CRC_ANCILLARY_NOWARN; + break; + + case PNG_CRC_ERROR_QUIT: /* Error/quit */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; + break; + + case PNG_CRC_WARN_DISCARD: /* Warn/discard data */ + + case PNG_CRC_DEFAULT: + default: + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + break; + } +} + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +/* Is it OK to set a transformation now? Only if png_start_read_image or + * png_read_update_info have not been called. It is not necessary for the IHDR + * to have been read in all cases; the need_IHDR parameter allows for this + * check too. + */ +static int +png_rtran_ok(png_structrp png_ptr, int need_IHDR) +{ + if (png_ptr != NULL) + { + if ((png_ptr->flags & PNG_FLAG_ROW_INIT) != 0) + png_app_error(png_ptr, + "invalid after png_start_read_image or png_read_update_info"); + + else if (need_IHDR && (png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_app_error(png_ptr, "invalid before the PNG header has been read"); + + else + { + /* Turn on failure to initialize correctly for all transforms. */ + png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED; + + return 1; /* Ok */ + } + } + + return 0; /* no png_error possible! */ +} +#endif + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +/* Handle alpha and tRNS via a background color */ +void PNGFAPI +png_set_background_fixed(png_structrp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, png_fixed_point background_gamma) +{ + png_debug(1, "in png_set_background_fixed"); + + if (png_rtran_ok(png_ptr, 0) == 0 || background_color == NULL) + return; + + if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) + { + png_warning(png_ptr, "Application must supply a known background gamma"); + return; + } + + png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA; + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + + png_ptr->background = *background_color; + png_ptr->background_gamma = background_gamma; + png_ptr->background_gamma_type = (png_byte)(background_gamma_code); + if (need_expand != 0) + png_ptr->transformations |= PNG_BACKGROUND_EXPAND; + else + png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_background(png_structrp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, double background_gamma) +{ + png_set_background_fixed(png_ptr, background_color, background_gamma_code, + need_expand, png_fixed(png_ptr, background_gamma, "png_set_background")); +} +# endif /* FLOATING_POINT */ +#endif /* READ_BACKGROUND */ + +/* Scale 16-bit depth files to 8-bit depth. If both of these are set then the + * one that pngrtran does first (scale) happens. This is necessary to allow the + * TRANSFORM and API behavior to be somewhat consistent, and it's simpler. + */ +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED +void PNGAPI +png_set_scale_16(png_structrp png_ptr) +{ + png_debug(1, "in png_set_scale_16"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= PNG_SCALE_16_TO_8; +} +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED +/* Chop 16-bit depth files to 8-bit depth */ +void PNGAPI +png_set_strip_16(png_structrp png_ptr) +{ + png_debug(1, "in png_set_strip_16"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= PNG_16_TO_8; +} +#endif + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED +void PNGAPI +png_set_strip_alpha(png_structrp png_ptr) +{ + png_debug(1, "in png_set_strip_alpha"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= PNG_STRIP_ALPHA; +} +#endif + +#if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED) +static png_fixed_point +translate_gamma_flags(png_structrp png_ptr, png_fixed_point output_gamma, + int is_screen) +{ + /* Check for flag values. The main reason for having the old Mac value as a + * flag is that it is pretty near impossible to work out what the correct + * value is from Apple documentation - a working Mac system is needed to + * discover the value! + */ + if (output_gamma == PNG_DEFAULT_sRGB || + output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB) + { + /* If there is no sRGB support this just sets the gamma to the standard + * sRGB value. (This is a side effect of using this function!) + */ +# ifdef PNG_READ_sRGB_SUPPORTED + png_ptr->flags |= PNG_FLAG_ASSUME_sRGB; +# else + PNG_UNUSED(png_ptr) +# endif + if (is_screen != 0) + output_gamma = PNG_GAMMA_sRGB; + else + output_gamma = PNG_GAMMA_sRGB_INVERSE; + } + + else if (output_gamma == PNG_GAMMA_MAC_18 || + output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18) + { + if (is_screen != 0) + output_gamma = PNG_GAMMA_MAC_OLD; + else + output_gamma = PNG_GAMMA_MAC_INVERSE; + } + + return output_gamma; +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +static png_fixed_point +convert_gamma_value(png_structrp png_ptr, double output_gamma) +{ + /* The following silently ignores cases where fixed point (times 100,000) + * gamma values are passed to the floating point API. This is safe and it + * means the fixed point constants work just fine with the floating point + * API. The alternative would just lead to undetected errors and spurious + * bug reports. Negative values fail inside the _fixed API unless they + * correspond to the flag values. + */ + if (output_gamma > 0 && output_gamma < 128) + output_gamma *= PNG_FP_1; + + /* This preserves -1 and -2 exactly: */ + output_gamma = floor(output_gamma + .5); + + if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN) + png_fixed_error(png_ptr, "gamma value"); + + return (png_fixed_point)output_gamma; +} +# endif +#endif /* READ_ALPHA_MODE || READ_GAMMA */ + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED +void PNGFAPI +png_set_alpha_mode_fixed(png_structrp png_ptr, int mode, + png_fixed_point output_gamma) +{ + int compose = 0; + png_fixed_point file_gamma; + + png_debug(1, "in png_set_alpha_mode"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/); + + /* Validate the value to ensure it is in a reasonable range. The value + * is expected to be 1 or greater, but this range test allows for some + * viewing correction values. The intent is to weed out users of this API + * who use the inverse of the gamma value accidentally! Since some of these + * values are reasonable this may have to be changed: + * + * 1.6.x: changed from 0.07..3 to 0.01..100 (to accommodate the optimal 16-bit + * gamma of 36, and its reciprocal.) + */ + if (output_gamma < 1000 || output_gamma > 10000000) + png_error(png_ptr, "output gamma out of expected range"); + + /* The default file gamma is the inverse of the output gamma; the output + * gamma may be changed below so get the file value first: + */ + file_gamma = png_reciprocal(output_gamma); + + /* There are really 8 possibilities here, composed of any combination + * of: + * + * premultiply the color channels + * do not encode non-opaque pixels + * encode the alpha as well as the color channels + * + * The differences disappear if the input/output ('screen') gamma is 1.0, + * because then the encoding is a no-op and there is only the choice of + * premultiplying the color channels or not. + * + * png_set_alpha_mode and png_set_background interact because both use + * png_compose to do the work. Calling both is only useful when + * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along + * with a default gamma value. Otherwise PNG_COMPOSE must not be set. + */ + switch (mode) + { + case PNG_ALPHA_PNG: /* default: png standard */ + /* No compose, but it may be set by png_set_background! */ + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + break; + + case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */ + compose = 1; + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + /* The output is linear: */ + output_gamma = PNG_FP_1; + break; + + case PNG_ALPHA_OPTIMIZED: /* associated, non-opaque pixels linear */ + compose = 1; + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA; + /* output_gamma records the encoding of opaque pixels! */ + break; + + case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */ + compose = 1; + png_ptr->transformations |= PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + break; + + default: + png_error(png_ptr, "invalid alpha mode"); + } + + /* Only set the default gamma if the file gamma has not been set (this has + * the side effect that the gamma in a second call to png_set_alpha_mode will + * be ignored.) + */ + if (png_ptr->colorspace.gamma == 0) + { + png_ptr->colorspace.gamma = file_gamma; + png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; + } + + /* But always set the output gamma: */ + png_ptr->screen_gamma = output_gamma; + + /* Finally, if pre-multiplying, set the background fields to achieve the + * desired result. + */ + if (compose != 0) + { + /* And obtain alpha pre-multiplication by composing on black: */ + memset(&png_ptr->background, 0, (sizeof png_ptr->background)); + png_ptr->background_gamma = png_ptr->colorspace.gamma; /* just in case */ + png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE; + png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; + + if ((png_ptr->transformations & PNG_COMPOSE) != 0) + png_error(png_ptr, + "conflicting calls to set alpha mode and background"); + + png_ptr->transformations |= PNG_COMPOSE; + } +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma) +{ + png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr, + output_gamma)); +} +# endif +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +/* Dither file to 8-bit. Supply a palette, the current number + * of elements in the palette, the maximum number of elements + * allowed, and a histogram if possible. If the current number + * of colors is greater than the maximum number, the palette will be + * modified to fit in the maximum number. "full_quantize" indicates + * whether we need a quantizing cube set up for RGB images, or if we + * simply are reducing the number of colors in a paletted image. + */ + +typedef struct png_dsort_struct +{ + struct png_dsort_struct * next; + png_byte left; + png_byte right; +} png_dsort; +typedef png_dsort * png_dsortp; +typedef png_dsort * * png_dsortpp; + +void PNGAPI +png_set_quantize(png_structrp png_ptr, png_colorp palette, + int num_palette, int maximum_colors, png_const_uint_16p histogram, + int full_quantize) +{ + png_debug(1, "in png_set_quantize"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= PNG_QUANTIZE; + + if (full_quantize == 0) + { + int i; + + png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr, + (png_alloc_size_t)((png_uint_32)num_palette * (sizeof (png_byte)))); + for (i = 0; i < num_palette; i++) + png_ptr->quantize_index[i] = (png_byte)i; + } + + if (num_palette > maximum_colors) + { + if (histogram != NULL) + { + /* This is easy enough, just throw out the least used colors. + * Perhaps not the best solution, but good enough. + */ + + int i; + + /* Initialize an array to sort colors */ + png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr, + (png_alloc_size_t)((png_uint_32)num_palette * (sizeof (png_byte)))); + + /* Initialize the quantize_sort array */ + for (i = 0; i < num_palette; i++) + png_ptr->quantize_sort[i] = (png_byte)i; + + /* Find the least used palette entries by starting a + * bubble sort, and running it until we have sorted + * out enough colors. Note that we don't care about + * sorting all the colors, just finding which are + * least used. + */ + + for (i = num_palette - 1; i >= maximum_colors; i--) + { + int done; /* To stop early if the list is pre-sorted */ + int j; + + done = 1; + for (j = 0; j < i; j++) + { + if (histogram[png_ptr->quantize_sort[j]] + < histogram[png_ptr->quantize_sort[j + 1]]) + { + png_byte t; + + t = png_ptr->quantize_sort[j]; + png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1]; + png_ptr->quantize_sort[j + 1] = t; + done = 0; + } + } + + if (done != 0) + break; + } + + /* Swap the palette around, and set up a table, if necessary */ + if (full_quantize != 0) + { + int j = num_palette; + + /* Put all the useful colors within the max, but don't + * move the others. + */ + for (i = 0; i < maximum_colors; i++) + { + if ((int)png_ptr->quantize_sort[i] >= maximum_colors) + { + do + j--; + while ((int)png_ptr->quantize_sort[j] >= maximum_colors); + + palette[i] = palette[j]; + } + } + } + else + { + int j = num_palette; + + /* Move all the used colors inside the max limit, and + * develop a translation table. + */ + for (i = 0; i < maximum_colors; i++) + { + /* Only move the colors we need to */ + if ((int)png_ptr->quantize_sort[i] >= maximum_colors) + { + png_color tmp_color; + + do + j--; + while ((int)png_ptr->quantize_sort[j] >= maximum_colors); + + tmp_color = palette[j]; + palette[j] = palette[i]; + palette[i] = tmp_color; + /* Indicate where the color went */ + png_ptr->quantize_index[j] = (png_byte)i; + png_ptr->quantize_index[i] = (png_byte)j; + } + } + + /* Find closest color for those colors we are not using */ + for (i = 0; i < num_palette; i++) + { + if ((int)png_ptr->quantize_index[i] >= maximum_colors) + { + int min_d, k, min_k, d_index; + + /* Find the closest color to one we threw out */ + d_index = png_ptr->quantize_index[i]; + min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); + for (k = 1, min_k = 0; k < maximum_colors; k++) + { + int d; + + d = PNG_COLOR_DIST(palette[d_index], palette[k]); + + if (d < min_d) + { + min_d = d; + min_k = k; + } + } + /* Point to closest color */ + png_ptr->quantize_index[i] = (png_byte)min_k; + } + } + } + png_free(png_ptr, png_ptr->quantize_sort); + png_ptr->quantize_sort = NULL; + } + else + { + /* This is much harder to do simply (and quickly). Perhaps + * we need to go through a median cut routine, but those + * don't always behave themselves with only a few colors + * as input. So we will just find the closest two colors, + * and throw out one of them (chosen somewhat randomly). + * [We don't understand this at all, so if someone wants to + * work on improving it, be our guest - AED, GRP] + */ + int i; + int max_d; + int num_new_palette; + png_dsortp t; + png_dsortpp hash; + + t = NULL; + + /* Initialize palette index arrays */ + png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr, + (png_alloc_size_t)((png_uint_32)num_palette * + (sizeof (png_byte)))); + png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr, + (png_alloc_size_t)((png_uint_32)num_palette * + (sizeof (png_byte)))); + + /* Initialize the sort array */ + for (i = 0; i < num_palette; i++) + { + png_ptr->index_to_palette[i] = (png_byte)i; + png_ptr->palette_to_index[i] = (png_byte)i; + } + + hash = (png_dsortpp)png_calloc(png_ptr, (png_alloc_size_t)(769 * + (sizeof (png_dsortp)))); + + num_new_palette = num_palette; + + /* Initial wild guess at how far apart the farthest pixel + * pair we will be eliminating will be. Larger + * numbers mean more areas will be allocated, Smaller + * numbers run the risk of not saving enough data, and + * having to do this all over again. + * + * I have not done extensive checking on this number. + */ + max_d = 96; + + while (num_new_palette > maximum_colors) + { + for (i = 0; i < num_new_palette - 1; i++) + { + int j; + + for (j = i + 1; j < num_new_palette; j++) + { + int d; + + d = PNG_COLOR_DIST(palette[i], palette[j]); + + if (d <= max_d) + { + + t = (png_dsortp)png_malloc_warn(png_ptr, + (png_alloc_size_t)(sizeof (png_dsort))); + + if (t == NULL) + break; + + t->next = hash[d]; + t->left = (png_byte)i; + t->right = (png_byte)j; + hash[d] = t; + } + } + if (t == NULL) + break; + } + + if (t != NULL) + for (i = 0; i <= max_d; i++) + { + if (hash[i] != NULL) + { + png_dsortp p; + + for (p = hash[i]; p; p = p->next) + { + if ((int)png_ptr->index_to_palette[p->left] + < num_new_palette && + (int)png_ptr->index_to_palette[p->right] + < num_new_palette) + { + int j, next_j; + + if (num_new_palette & 0x01) + { + j = p->left; + next_j = p->right; + } + else + { + j = p->right; + next_j = p->left; + } + + num_new_palette--; + palette[png_ptr->index_to_palette[j]] + = palette[num_new_palette]; + if (full_quantize == 0) + { + int k; + + for (k = 0; k < num_palette; k++) + { + if (png_ptr->quantize_index[k] == + png_ptr->index_to_palette[j]) + png_ptr->quantize_index[k] = + png_ptr->index_to_palette[next_j]; + + if ((int)png_ptr->quantize_index[k] == + num_new_palette) + png_ptr->quantize_index[k] = + png_ptr->index_to_palette[j]; + } + } + + png_ptr->index_to_palette[png_ptr->palette_to_index + [num_new_palette]] = png_ptr->index_to_palette[j]; + + png_ptr->palette_to_index[png_ptr->index_to_palette[j]] + = png_ptr->palette_to_index[num_new_palette]; + + png_ptr->index_to_palette[j] = + (png_byte)num_new_palette; + + png_ptr->palette_to_index[num_new_palette] = + (png_byte)j; + } + if (num_new_palette <= maximum_colors) + break; + } + if (num_new_palette <= maximum_colors) + break; + } + } + + for (i = 0; i < 769; i++) + { + if (hash[i] != NULL) + { + png_dsortp p = hash[i]; + while (p) + { + t = p->next; + png_free(png_ptr, p); + p = t; + } + } + hash[i] = 0; + } + max_d += 96; + } + png_free(png_ptr, hash); + png_free(png_ptr, png_ptr->palette_to_index); + png_free(png_ptr, png_ptr->index_to_palette); + png_ptr->palette_to_index = NULL; + png_ptr->index_to_palette = NULL; + } + num_palette = maximum_colors; + } + if (png_ptr->palette == NULL) + { + png_ptr->palette = palette; + } + png_ptr->num_palette = (png_uint_16)num_palette; + + if (full_quantize != 0) + { + int i; + png_bytep distance; + int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS + + PNG_QUANTIZE_BLUE_BITS; + int num_red = (1 << PNG_QUANTIZE_RED_BITS); + int num_green = (1 << PNG_QUANTIZE_GREEN_BITS); + int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS); + size_t num_entries = ((size_t)1 << total_bits); + + png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr, + (png_alloc_size_t)(num_entries * (sizeof (png_byte)))); + + distance = (png_bytep)png_malloc(png_ptr, (png_alloc_size_t)(num_entries * + (sizeof (png_byte)))); + + memset(distance, 0xff, num_entries * (sizeof (png_byte))); + + for (i = 0; i < num_palette; i++) + { + int ir, ig, ib; + int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS)); + int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS)); + int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS)); + + for (ir = 0; ir < num_red; ir++) + { + /* int dr = abs(ir - r); */ + int dr = ((ir > r) ? ir - r : r - ir); + int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS + + PNG_QUANTIZE_GREEN_BITS)); + + for (ig = 0; ig < num_green; ig++) + { + /* int dg = abs(ig - g); */ + int dg = ((ig > g) ? ig - g : g - ig); + int dt = dr + dg; + int dm = ((dr > dg) ? dr : dg); + int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS); + + for (ib = 0; ib < num_blue; ib++) + { + int d_index = index_g | ib; + /* int db = abs(ib - b); */ + int db = ((ib > b) ? ib - b : b - ib); + int dmax = ((dm > db) ? dm : db); + int d = dmax + dt + db; + + if (d < (int)distance[d_index]) + { + distance[d_index] = (png_byte)d; + png_ptr->palette_lookup[d_index] = (png_byte)i; + } + } + } + } + } + + png_free(png_ptr, distance); + } +} +#endif /* READ_QUANTIZE */ + +#ifdef PNG_READ_GAMMA_SUPPORTED +void PNGFAPI +png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma, + png_fixed_point file_gamma) +{ + png_debug(1, "in png_set_gamma_fixed"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + /* New in libpng-1.5.4 - reserve particular negative values as flags. */ + scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/); + file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/); + + /* Checking the gamma values for being >0 was added in 1.5.4 along with the + * premultiplied alpha support; this actually hides an undocumented feature + * of the previous implementation which allowed gamma processing to be + * disabled in background handling. There is no evidence (so far) that this + * was being used; however, png_set_background itself accepted and must still + * accept '0' for the gamma value it takes, because it isn't always used. + * + * Since this is an API change (albeit a very minor one that removes an + * undocumented API feature) the following checks were only enabled in + * libpng-1.6.0. + */ + if (file_gamma <= 0) + png_error(png_ptr, "invalid file gamma in png_set_gamma"); + + if (scrn_gamma <= 0) + png_error(png_ptr, "invalid screen gamma in png_set_gamma"); + + /* Set the gamma values unconditionally - this overrides the value in the PNG + * file if a gAMA chunk was present. png_set_alpha_mode provides a + * different, easier, way to default the file gamma. + */ + png_ptr->colorspace.gamma = file_gamma; + png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; + png_ptr->screen_gamma = scrn_gamma; +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma) +{ + png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma), + convert_gamma_value(png_ptr, file_gamma)); +} +# endif /* FLOATING_POINT */ +#endif /* READ_GAMMA */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* Expand paletted images to RGB, expand grayscale images of + * less than 8-bit depth to 8-bit depth, and expand tRNS chunks + * to alpha channels. + */ +void PNGAPI +png_set_expand(png_structrp png_ptr) +{ + png_debug(1, "in png_set_expand"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); +} + +/* GRR 19990627: the following three functions currently are identical + * to png_set_expand(). However, it is entirely reasonable that someone + * might wish to expand an indexed image to RGB but *not* expand a single, + * fully transparent palette entry to a full alpha channel--perhaps instead + * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace + * the transparent color with a particular RGB value, or drop tRNS entirely. + * IOW, a future version of the library may make the transformations flag + * a bit more fine-grained, with separate bits for each of these three + * functions. + * + * More to the point, these functions make it obvious what libpng will be + * doing, whereas "expand" can (and does) mean any number of things. + * + * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified + * to expand only the sample depth but not to expand the tRNS to alpha + * and its name was changed to png_set_expand_gray_1_2_4_to_8(). + */ + +/* Expand paletted images to RGB. */ +void PNGAPI +png_set_palette_to_rgb(png_structrp png_ptr) +{ + png_debug(1, "in png_set_palette_to_rgb"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); +} + +/* Expand grayscale images of less than 8-bit depth to 8 bits. */ +void PNGAPI +png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr) +{ + png_debug(1, "in png_set_expand_gray_1_2_4_to_8"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= PNG_EXPAND; +} + +/* Expand tRNS chunks to alpha channels. */ +void PNGAPI +png_set_tRNS_to_alpha(png_structrp png_ptr) +{ + png_debug(1, "in png_set_tRNS_to_alpha"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); +} +#endif /* READ_EXPAND */ + +#ifdef PNG_READ_EXPAND_16_SUPPORTED +/* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise + * it may not work correctly.) + */ +void PNGAPI +png_set_expand_16(png_structrp png_ptr) +{ + png_debug(1, "in png_set_expand_16"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS); +} +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +void PNGAPI +png_set_gray_to_rgb(png_structrp png_ptr) +{ + png_debug(1, "in png_set_gray_to_rgb"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + /* Because rgb must be 8 bits or more: */ + png_set_expand_gray_1_2_4_to_8(png_ptr); + png_ptr->transformations |= PNG_GRAY_TO_RGB; +} +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +void PNGFAPI +png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action, + png_fixed_point red, png_fixed_point green) +{ + png_debug(1, "in png_set_rgb_to_gray"); + + /* Need the IHDR here because of the check on color_type below. */ + /* TODO: fix this */ + if (png_rtran_ok(png_ptr, 1) == 0) + return; + + switch (error_action) + { + case PNG_ERROR_ACTION_NONE: + png_ptr->transformations |= PNG_RGB_TO_GRAY; + break; + + case PNG_ERROR_ACTION_WARN: + png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; + break; + + case PNG_ERROR_ACTION_ERROR: + png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; + break; + + default: + png_error(png_ptr, "invalid error action to rgb_to_gray"); + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) +#ifdef PNG_READ_EXPAND_SUPPORTED + png_ptr->transformations |= PNG_EXPAND; +#else + { + /* Make this an error in 1.6 because otherwise the application may assume + * that it just worked and get a memory overwrite. + */ + png_error(png_ptr, + "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED"); + + /* png_ptr->transformations &= ~PNG_RGB_TO_GRAY; */ + } +#endif + { + if (red >= 0 && green >= 0 && red + green <= PNG_FP_1) + { + png_uint_16 red_int, green_int; + + /* NOTE: this calculation does not round, but this behavior is retained + * for consistency; the inaccuracy is very small. The code here always + * overwrites the coefficients, regardless of whether they have been + * defaulted or set already. + */ + red_int = (png_uint_16)(((png_uint_32)red*32768)/100000); + green_int = (png_uint_16)(((png_uint_32)green*32768)/100000); + + png_ptr->rgb_to_gray_red_coeff = red_int; + png_ptr->rgb_to_gray_green_coeff = green_int; + png_ptr->rgb_to_gray_coefficients_set = 1; + } + + else + { + if (red >= 0 && green >= 0) + png_app_warning(png_ptr, + "ignoring out of range rgb_to_gray coefficients"); + + /* Use the defaults, from the cHRM chunk if set, else the historical + * values which are close to the sRGB/HDTV/ITU-Rec 709 values. See + * png_do_rgb_to_gray for more discussion of the values. In this case + * the coefficients are not marked as 'set' and are not overwritten if + * something has already provided a default. + */ + if (png_ptr->rgb_to_gray_red_coeff == 0 && + png_ptr->rgb_to_gray_green_coeff == 0) + { + png_ptr->rgb_to_gray_red_coeff = 6968; + png_ptr->rgb_to_gray_green_coeff = 23434; + /* png_ptr->rgb_to_gray_blue_coeff = 2366; */ + } + } + } +} + +#ifdef PNG_FLOATING_POINT_SUPPORTED +/* Convert a RGB image to a grayscale of the same width. This allows us, + * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. + */ + +void PNGAPI +png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red, + double green) +{ + png_set_rgb_to_gray_fixed(png_ptr, error_action, + png_fixed(png_ptr, red, "rgb to gray red coefficient"), + png_fixed(png_ptr, green, "rgb to gray green coefficient")); +} +#endif /* FLOATING POINT */ + +#endif /* RGB_TO_GRAY */ + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +void PNGAPI +png_set_read_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr + read_user_transform_fn) +{ + png_debug(1, "in png_set_read_user_transform_fn"); + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + png_ptr->transformations |= PNG_USER_TRANSFORM; + png_ptr->read_user_transform_fn = read_user_transform_fn; +#endif +} +#endif + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +#ifdef PNG_READ_GAMMA_SUPPORTED +/* In the case of gamma transformations only do transformations on images where + * the [file] gamma and screen_gamma are not close reciprocals, otherwise it + * slows things down slightly, and also needlessly introduces small errors. + */ +static int /* PRIVATE */ +png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma) +{ + /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma + * correction as a difference of the overall transform from 1.0 + * + * We want to compare the threshold with s*f - 1, if we get + * overflow here it is because of wacky gamma values so we + * turn on processing anyway. + */ + png_fixed_point gtest; + return !png_muldiv(>est, screen_gamma, file_gamma, PNG_FP_1) || + png_gamma_significant(gtest); +} +#endif + +/* Initialize everything needed for the read. This includes modifying + * the palette. + */ + +/* For the moment 'png_init_palette_transformations' and + * 'png_init_rgb_transformations' only do some flag canceling optimizations. + * The intent is that these two routines should have palette or rgb operations + * extracted from 'png_init_read_transformations'. + */ +static void /* PRIVATE */ +png_init_palette_transformations(png_structrp png_ptr) +{ + /* Called to handle the (input) palette case. In png_do_read_transformations + * the first step is to expand the palette if requested, so this code must + * take care to only make changes that are invariant with respect to the + * palette expansion, or only do them if there is no expansion. + * + * STRIP_ALPHA has already been handled in the caller (by setting num_trans + * to 0.) + */ + int input_has_alpha = 0; + int input_has_transparency = 0; + + if (png_ptr->num_trans > 0) + { + int i; + + /* Ignore if all the entries are opaque (unlikely!) */ + for (i=0; i<png_ptr->num_trans; ++i) + { + if (png_ptr->trans_alpha[i] == 255) + continue; + else if (png_ptr->trans_alpha[i] == 0) + input_has_transparency = 1; + else + { + input_has_transparency = 1; + input_has_alpha = 1; + break; + } + } + } + + /* If no alpha we can optimize. */ + if (input_has_alpha == 0) + { + /* Any alpha means background and associative alpha processing is + * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA + * and ENCODE_ALPHA are irrelevant. + */ + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + + if (input_has_transparency == 0) + png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); + } + +#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) + /* png_set_background handling - deals with the complexity of whether the + * background color is in the file format or the screen format in the case + * where an 'expand' will happen. + */ + + /* The following code cannot be entered in the alpha pre-multiplication case + * because PNG_BACKGROUND_EXPAND is cancelled below. + */ + if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 && + (png_ptr->transformations & PNG_EXPAND) != 0) + { + { + png_ptr->background.red = + png_ptr->palette[png_ptr->background.index].red; + png_ptr->background.green = + png_ptr->palette[png_ptr->background.index].green; + png_ptr->background.blue = + png_ptr->palette[png_ptr->background.index].blue; + +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0) + { + if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0) + { + /* Invert the alpha channel (in tRNS) unless the pixels are + * going to be expanded, in which case leave it for later + */ + int i, istop = png_ptr->num_trans; + + for (i = 0; i < istop; i++) + png_ptr->trans_alpha[i] = + (png_byte)(255 - png_ptr->trans_alpha[i]); + } + } +#endif /* READ_INVERT_ALPHA */ + } + } /* background expand and (therefore) no alpha association. */ +#endif /* READ_EXPAND && READ_BACKGROUND */ +} + +static void /* PRIVATE */ +png_init_rgb_transformations(png_structrp png_ptr) +{ + /* Added to libpng-1.5.4: check the color type to determine whether there + * is any alpha or transparency in the image and simply cancel the + * background and alpha mode stuff if there isn't. + */ + int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0; + int input_has_transparency = png_ptr->num_trans > 0; + + /* If no alpha we can optimize. */ + if (input_has_alpha == 0) + { + /* Any alpha means background and associative alpha processing is + * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA + * and ENCODE_ALPHA are irrelevant. + */ +# ifdef PNG_READ_ALPHA_MODE_SUPPORTED + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; +# endif + + if (input_has_transparency == 0) + png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); + } + +#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) + /* png_set_background handling - deals with the complexity of whether the + * background color is in the file format or the screen format in the case + * where an 'expand' will happen. + */ + + /* The following code cannot be entered in the alpha pre-multiplication case + * because PNG_BACKGROUND_EXPAND is cancelled below. + */ + if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 && + (png_ptr->transformations & PNG_EXPAND) != 0 && + (png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) + /* i.e., GRAY or GRAY_ALPHA */ + { + { + /* Expand background and tRNS chunks */ + int gray = png_ptr->background.gray; + int trans_gray = png_ptr->trans_color.gray; + + switch (png_ptr->bit_depth) + { + case 1: + gray *= 0xff; + trans_gray *= 0xff; + break; + + case 2: + gray *= 0x55; + trans_gray *= 0x55; + break; + + case 4: + gray *= 0x11; + trans_gray *= 0x11; + break; + + default: + + case 8: + /* FALLTHROUGH */ /* (Already 8 bits) */ + + case 16: + /* Already a full 16 bits */ + break; + } + + png_ptr->background.red = png_ptr->background.green = + png_ptr->background.blue = (png_uint_16)gray; + + if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0) + { + png_ptr->trans_color.red = png_ptr->trans_color.green = + png_ptr->trans_color.blue = (png_uint_16)trans_gray; + } + } + } /* background expand and (therefore) no alpha association. */ +#endif /* READ_EXPAND && READ_BACKGROUND */ +} + +void /* PRIVATE */ +png_init_read_transformations(png_structrp png_ptr) +{ + png_debug(1, "in png_init_read_transformations"); + + /* This internal function is called from png_read_start_row in pngrutil.c + * and it is called before the 'rowbytes' calculation is done, so the code + * in here can change or update the transformations flags. + * + * First do updates that do not depend on the details of the PNG image data + * being processed. + */ + +#ifdef PNG_READ_GAMMA_SUPPORTED + /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds + * png_set_alpha_mode and this is another source for a default file gamma so + * the test needs to be performed later - here. In addition prior to 1.5.4 + * the tests were repeated for the PALETTE color type here - this is no + * longer necessary (and doesn't seem to have been necessary before.) + */ + { + /* The following temporary indicates if overall gamma correction is + * required. + */ + int gamma_correction = 0; + + if (png_ptr->colorspace.gamma != 0) /* has been set */ + { + if (png_ptr->screen_gamma != 0) /* screen set too */ + gamma_correction = png_gamma_threshold(png_ptr->colorspace.gamma, + png_ptr->screen_gamma); + + else + /* Assume the output matches the input; a long time default behavior + * of libpng, although the standard has nothing to say about this. + */ + png_ptr->screen_gamma = png_reciprocal(png_ptr->colorspace.gamma); + } + + else if (png_ptr->screen_gamma != 0) + /* The converse - assume the file matches the screen, note that this + * perhaps undesirable default can (from 1.5.4) be changed by calling + * png_set_alpha_mode (even if the alpha handling mode isn't required + * or isn't changed from the default.) + */ + png_ptr->colorspace.gamma = png_reciprocal(png_ptr->screen_gamma); + + else /* neither are set */ + /* Just in case the following prevents any processing - file and screen + * are both assumed to be linear and there is no way to introduce a + * third gamma value other than png_set_background with 'UNIQUE', and, + * prior to 1.5.4 + */ + png_ptr->screen_gamma = png_ptr->colorspace.gamma = PNG_FP_1; + + /* We have a gamma value now. */ + png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; + + /* Now turn the gamma transformation on or off as appropriate. Notice + * that PNG_GAMMA just refers to the file->screen correction. Alpha + * composition may independently cause gamma correction because it needs + * linear data (e.g. if the file has a gAMA chunk but the screen gamma + * hasn't been specified.) In any case this flag may get turned off in + * the code immediately below if the transform can be handled outside the + * row loop. + */ + if (gamma_correction != 0) + png_ptr->transformations |= PNG_GAMMA; + + else + png_ptr->transformations &= ~PNG_GAMMA; + } +#endif + + /* Certain transformations have the effect of preventing other + * transformations that happen afterward in png_do_read_transformations; + * resolve the interdependencies here. From the code of + * png_do_read_transformations the order is: + * + * 1) PNG_EXPAND (including PNG_EXPAND_tRNS) + * 2) PNG_STRIP_ALPHA (if no compose) + * 3) PNG_RGB_TO_GRAY + * 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY + * 5) PNG_COMPOSE + * 6) PNG_GAMMA + * 7) PNG_STRIP_ALPHA (if compose) + * 8) PNG_ENCODE_ALPHA + * 9) PNG_SCALE_16_TO_8 + * 10) PNG_16_TO_8 + * 11) PNG_QUANTIZE (converts to palette) + * 12) PNG_EXPAND_16 + * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY + * 14) PNG_INVERT_MONO + * 15) PNG_INVERT_ALPHA + * 16) PNG_SHIFT + * 17) PNG_PACK + * 18) PNG_BGR + * 19) PNG_PACKSWAP + * 20) PNG_FILLER (includes PNG_ADD_ALPHA) + * 21) PNG_SWAP_ALPHA + * 22) PNG_SWAP_BYTES + * 23) PNG_USER_TRANSFORM [must be last] + */ +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 && + (png_ptr->transformations & PNG_COMPOSE) == 0) + { + /* Stripping the alpha channel happens immediately after the 'expand' + * transformations, before all other transformation, so it cancels out + * the alpha handling. It has the side effect negating the effect of + * PNG_EXPAND_tRNS too: + */ + png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA | + PNG_EXPAND_tRNS); + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + + /* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen + * so transparency information would remain just so long as it wasn't + * expanded. This produces unexpected API changes if the set of things + * that do PNG_EXPAND_tRNS changes (perfectly possible given the + * documentation - which says ask for what you want, accept what you + * get.) This makes the behavior consistent from 1.5.4: + */ + png_ptr->num_trans = 0; + } +#endif /* STRIP_ALPHA supported, no COMPOSE */ + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA + * settings will have no effect. + */ + if (png_gamma_significant(png_ptr->screen_gamma) == 0) + { + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + } +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Make sure the coefficients for the rgb to gray conversion are set + * appropriately. + */ + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) + png_colorspace_set_rgb_coefficients(png_ptr); +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) + /* Detect gray background and attempt to enable optimization for + * gray --> RGB case. + * + * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or + * RGB_ALPHA (in which case need_expand is superfluous anyway), the + * background color might actually be gray yet not be flagged as such. + * This is not a problem for the current code, which uses + * PNG_BACKGROUND_IS_GRAY only to decide when to do the + * png_do_gray_to_rgb() transformation. + * + * TODO: this code needs to be revised to avoid the complexity and + * interdependencies. The color type of the background should be recorded in + * png_set_background, along with the bit depth, then the code has a record + * of exactly what color space the background is currently in. + */ + if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0) + { + /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if + * the file was grayscale the background value is gray. + */ + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) + png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; + } + + else if ((png_ptr->transformations & PNG_COMPOSE) != 0) + { + /* PNG_COMPOSE: png_set_background was called with need_expand false, + * so the color is in the color space of the output or png_set_alpha_mode + * was called and the color is black. Ignore RGB_TO_GRAY because that + * happens before GRAY_TO_RGB. + */ + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0) + { + if (png_ptr->background.red == png_ptr->background.green && + png_ptr->background.red == png_ptr->background.blue) + { + png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; + png_ptr->background.gray = png_ptr->background.red; + } + } + } +#endif /* READ_EXPAND && READ_BACKGROUND */ +#endif /* READ_GRAY_TO_RGB */ + + /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations + * can be performed directly on the palette, and some (such as rgb to gray) + * can be optimized inside the palette. This is particularly true of the + * composite (background and alpha) stuff, which can be pretty much all done + * in the palette even if the result is expanded to RGB or gray afterward. + * + * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and + * earlier and the palette stuff is actually handled on the first row. This + * leads to the reported bug that the palette returned by png_get_PLTE is not + * updated. + */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + png_init_palette_transformations(png_ptr); + + else + png_init_rgb_transformations(png_ptr); + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ + defined(PNG_READ_EXPAND_16_SUPPORTED) + if ((png_ptr->transformations & PNG_EXPAND_16) != 0 && + (png_ptr->transformations & PNG_COMPOSE) != 0 && + (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 && + png_ptr->bit_depth != 16) + { + /* TODO: fix this. Because the expand_16 operation is after the compose + * handling the background color must be 8, not 16, bits deep, but the + * application will supply a 16-bit value so reduce it here. + * + * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at + * present, so that case is ok (until do_expand_16 is moved.) + * + * NOTE: this discards the low 16 bits of the user supplied background + * color, but until expand_16 works properly there is no choice! + */ +# define CHOP(x) (x)=((png_uint_16)PNG_DIV257(x)) + CHOP(png_ptr->background.red); + CHOP(png_ptr->background.green); + CHOP(png_ptr->background.blue); + CHOP(png_ptr->background.gray); +# undef CHOP + } +#endif /* READ_BACKGROUND && READ_EXPAND_16 */ + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ + (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \ + defined(PNG_READ_STRIP_16_TO_8_SUPPORTED)) + if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) != 0 && + (png_ptr->transformations & PNG_COMPOSE) != 0 && + (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 && + png_ptr->bit_depth == 16) + { + /* On the other hand, if a 16-bit file is to be reduced to 8-bits per + * component this will also happen after PNG_COMPOSE and so the background + * color must be pre-expanded here. + * + * TODO: fix this too. + */ + png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257); + png_ptr->background.green = + (png_uint_16)(png_ptr->background.green * 257); + png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257); + png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257); + } +#endif + + /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the + * background support (see the comments in scripts/pnglibconf.dfa), this + * allows pre-multiplication of the alpha channel to be implemented as + * compositing on black. This is probably sub-optimal and has been done in + * 1.5.4 betas simply to enable external critique and testing (i.e. to + * implement the new API quickly, without lots of internal changes.) + */ + +#ifdef PNG_READ_GAMMA_SUPPORTED +# ifdef PNG_READ_BACKGROUND_SUPPORTED + /* Includes ALPHA_MODE */ + png_ptr->background_1 = png_ptr->background; +# endif + + /* This needs to change - in the palette image case a whole set of tables are + * built when it would be quicker to just calculate the correct value for + * each palette entry directly. Also, the test is too tricky - why check + * PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that + * PNG_GAMMA is cancelled even if the gamma is known? The test excludes the + * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction + * the gamma tables will not be built even if composition is required on a + * gamma encoded value. + * + * In 1.5.4 this is addressed below by an additional check on the individual + * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the + * tables. + */ + if ((png_ptr->transformations & PNG_GAMMA) != 0 || + ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0 && + (png_gamma_significant(png_ptr->colorspace.gamma) != 0 || + png_gamma_significant(png_ptr->screen_gamma) != 0)) || + ((png_ptr->transformations & PNG_COMPOSE) != 0 && + (png_gamma_significant(png_ptr->colorspace.gamma) != 0 || + png_gamma_significant(png_ptr->screen_gamma) != 0 +# ifdef PNG_READ_BACKGROUND_SUPPORTED + || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE && + png_gamma_significant(png_ptr->background_gamma) != 0) +# endif + )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 && + png_gamma_significant(png_ptr->screen_gamma) != 0)) + { + png_build_gamma_table(png_ptr, png_ptr->bit_depth); + +#ifdef PNG_READ_BACKGROUND_SUPPORTED + if ((png_ptr->transformations & PNG_COMPOSE) != 0) + { + /* Issue a warning about this combination: because RGB_TO_GRAY is + * optimized to do the gamma transform if present yet do_background has + * to do the same thing if both options are set a + * double-gamma-correction happens. This is true in all versions of + * libpng to date. + */ + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) + png_warning(png_ptr, + "libpng does not support gamma+background+rgb_to_gray"); + + if ((png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) != 0) + { + /* We don't get to here unless there is a tRNS chunk with non-opaque + * entries - see the checking code at the start of this function. + */ + png_color back, back_1; + png_colorp palette = png_ptr->palette; + int num_palette = png_ptr->num_palette; + int i; + if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) + { + + back.red = png_ptr->gamma_table[png_ptr->background.red]; + back.green = png_ptr->gamma_table[png_ptr->background.green]; + back.blue = png_ptr->gamma_table[png_ptr->background.blue]; + + back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; + back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; + back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; + } + else + { + png_fixed_point g, gs; + + switch (png_ptr->background_gamma_type) + { + case PNG_BACKGROUND_GAMMA_SCREEN: + g = (png_ptr->screen_gamma); + gs = PNG_FP_1; + break; + + case PNG_BACKGROUND_GAMMA_FILE: + g = png_reciprocal(png_ptr->colorspace.gamma); + gs = png_reciprocal2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma); + break; + + case PNG_BACKGROUND_GAMMA_UNIQUE: + g = png_reciprocal(png_ptr->background_gamma); + gs = png_reciprocal2(png_ptr->background_gamma, + png_ptr->screen_gamma); + break; + default: + g = PNG_FP_1; /* back_1 */ + gs = PNG_FP_1; /* back */ + break; + } + + if (png_gamma_significant(gs) != 0) + { + back.red = png_gamma_8bit_correct(png_ptr->background.red, + gs); + back.green = png_gamma_8bit_correct(png_ptr->background.green, + gs); + back.blue = png_gamma_8bit_correct(png_ptr->background.blue, + gs); + } + + else + { + back.red = (png_byte)png_ptr->background.red; + back.green = (png_byte)png_ptr->background.green; + back.blue = (png_byte)png_ptr->background.blue; + } + + if (png_gamma_significant(g) != 0) + { + back_1.red = png_gamma_8bit_correct(png_ptr->background.red, + g); + back_1.green = png_gamma_8bit_correct( + png_ptr->background.green, g); + back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue, + g); + } + + else + { + back_1.red = (png_byte)png_ptr->background.red; + back_1.green = (png_byte)png_ptr->background.green; + back_1.blue = (png_byte)png_ptr->background.blue; + } + } + + for (i = 0; i < num_palette; i++) + { + if (i < (int)png_ptr->num_trans && + png_ptr->trans_alpha[i] != 0xff) + { + if (png_ptr->trans_alpha[i] == 0) + { + palette[i] = back; + } + else /* if (png_ptr->trans_alpha[i] != 0xff) */ + { + png_byte v, w; + + v = png_ptr->gamma_to_1[palette[i].red]; + png_composite(w, v, png_ptr->trans_alpha[i], back_1.red); + palette[i].red = png_ptr->gamma_from_1[w]; + + v = png_ptr->gamma_to_1[palette[i].green]; + png_composite(w, v, png_ptr->trans_alpha[i], back_1.green); + palette[i].green = png_ptr->gamma_from_1[w]; + + v = png_ptr->gamma_to_1[palette[i].blue]; + png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue); + palette[i].blue = png_ptr->gamma_from_1[w]; + } + } + else + { + palette[i].red = png_ptr->gamma_table[palette[i].red]; + palette[i].green = png_ptr->gamma_table[palette[i].green]; + palette[i].blue = png_ptr->gamma_table[palette[i].blue]; + } + } + + /* Prevent the transformations being done again. + * + * NOTE: this is highly dubious; it removes the transformations in + * place. This seems inconsistent with the general treatment of the + * transformations elsewhere. + */ + png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA); + } /* color_type == PNG_COLOR_TYPE_PALETTE */ + + /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ + else /* color_type != PNG_COLOR_TYPE_PALETTE */ + { + int gs_sig, g_sig; + png_fixed_point g = PNG_FP_1; /* Correction to linear */ + png_fixed_point gs = PNG_FP_1; /* Correction to screen */ + + switch (png_ptr->background_gamma_type) + { + case PNG_BACKGROUND_GAMMA_SCREEN: + g = png_ptr->screen_gamma; + /* gs = PNG_FP_1; */ + break; + + case PNG_BACKGROUND_GAMMA_FILE: + g = png_reciprocal(png_ptr->colorspace.gamma); + gs = png_reciprocal2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma); + break; + + case PNG_BACKGROUND_GAMMA_UNIQUE: + g = png_reciprocal(png_ptr->background_gamma); + gs = png_reciprocal2(png_ptr->background_gamma, + png_ptr->screen_gamma); + break; + + default: + png_error(png_ptr, "invalid background gamma type"); + } + + g_sig = png_gamma_significant(g); + gs_sig = png_gamma_significant(gs); + + if (g_sig != 0) + png_ptr->background_1.gray = png_gamma_correct(png_ptr, + png_ptr->background.gray, g); + + if (gs_sig != 0) + png_ptr->background.gray = png_gamma_correct(png_ptr, + png_ptr->background.gray, gs); + + if ((png_ptr->background.red != png_ptr->background.green) || + (png_ptr->background.red != png_ptr->background.blue) || + (png_ptr->background.red != png_ptr->background.gray)) + { + /* RGB or RGBA with color background */ + if (g_sig != 0) + { + png_ptr->background_1.red = png_gamma_correct(png_ptr, + png_ptr->background.red, g); + + png_ptr->background_1.green = png_gamma_correct(png_ptr, + png_ptr->background.green, g); + + png_ptr->background_1.blue = png_gamma_correct(png_ptr, + png_ptr->background.blue, g); + } + + if (gs_sig != 0) + { + png_ptr->background.red = png_gamma_correct(png_ptr, + png_ptr->background.red, gs); + + png_ptr->background.green = png_gamma_correct(png_ptr, + png_ptr->background.green, gs); + + png_ptr->background.blue = png_gamma_correct(png_ptr, + png_ptr->background.blue, gs); + } + } + + else + { + /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ + png_ptr->background_1.red = png_ptr->background_1.green + = png_ptr->background_1.blue = png_ptr->background_1.gray; + + png_ptr->background.red = png_ptr->background.green + = png_ptr->background.blue = png_ptr->background.gray; + } + + /* The background is now in screen gamma: */ + png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN; + } /* color_type != PNG_COLOR_TYPE_PALETTE */ + }/* png_ptr->transformations & PNG_BACKGROUND */ + + else + /* Transformation does not include PNG_BACKGROUND */ +#endif /* READ_BACKGROUND */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* RGB_TO_GRAY needs to have non-gamma-corrected values! */ + && ((png_ptr->transformations & PNG_EXPAND) == 0 || + (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0) +#endif + ) + { + png_colorp palette = png_ptr->palette; + int num_palette = png_ptr->num_palette; + int i; + + /* NOTE: there are other transformations that should probably be in + * here too. + */ + for (i = 0; i < num_palette; i++) + { + palette[i].red = png_ptr->gamma_table[palette[i].red]; + palette[i].green = png_ptr->gamma_table[palette[i].green]; + palette[i].blue = png_ptr->gamma_table[palette[i].blue]; + } + + /* Done the gamma correction. */ + png_ptr->transformations &= ~PNG_GAMMA; + } /* color_type == PALETTE && !PNG_BACKGROUND transformation */ + } +#ifdef PNG_READ_BACKGROUND_SUPPORTED + else +#endif +#endif /* READ_GAMMA */ + +#ifdef PNG_READ_BACKGROUND_SUPPORTED + /* No GAMMA transformation (see the hanging else 4 lines above) */ + if ((png_ptr->transformations & PNG_COMPOSE) != 0 && + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) + { + int i; + int istop = (int)png_ptr->num_trans; + png_color back; + png_colorp palette = png_ptr->palette; + + back.red = (png_byte)png_ptr->background.red; + back.green = (png_byte)png_ptr->background.green; + back.blue = (png_byte)png_ptr->background.blue; + + for (i = 0; i < istop; i++) + { + if (png_ptr->trans_alpha[i] == 0) + { + palette[i] = back; + } + + else if (png_ptr->trans_alpha[i] != 0xff) + { + /* The png_composite() macro is defined in png.h */ + png_composite(palette[i].red, palette[i].red, + png_ptr->trans_alpha[i], back.red); + + png_composite(palette[i].green, palette[i].green, + png_ptr->trans_alpha[i], back.green); + + png_composite(palette[i].blue, palette[i].blue, + png_ptr->trans_alpha[i], back.blue); + } + } + + png_ptr->transformations &= ~PNG_COMPOSE; + } +#endif /* READ_BACKGROUND */ + +#ifdef PNG_READ_SHIFT_SUPPORTED + if ((png_ptr->transformations & PNG_SHIFT) != 0 && + (png_ptr->transformations & PNG_EXPAND) == 0 && + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) + { + int i; + int istop = png_ptr->num_palette; + int shift = 8 - png_ptr->sig_bit.red; + + png_ptr->transformations &= ~PNG_SHIFT; + + /* significant bits can be in the range 1 to 7 for a meaningful result, if + * the number of significant bits is 0 then no shift is done (this is an + * error condition which is silently ignored.) + */ + if (shift > 0 && shift < 8) + for (i=0; i<istop; ++i) + { + int component = png_ptr->palette[i].red; + + component >>= shift; + png_ptr->palette[i].red = (png_byte)component; + } + + shift = 8 - png_ptr->sig_bit.green; + if (shift > 0 && shift < 8) + for (i=0; i<istop; ++i) + { + int component = png_ptr->palette[i].green; + + component >>= shift; + png_ptr->palette[i].green = (png_byte)component; + } + + shift = 8 - png_ptr->sig_bit.blue; + if (shift > 0 && shift < 8) + for (i=0; i<istop; ++i) + { + int component = png_ptr->palette[i].blue; + + component >>= shift; + png_ptr->palette[i].blue = (png_byte)component; + } + } +#endif /* READ_SHIFT */ +} + +/* Modify the info structure to reflect the transformations. The + * info should be updated so a PNG file could be written with it, + * assuming the transformations result in valid PNG data. + */ +void /* PRIVATE */ +png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr) +{ + png_debug(1, "in png_read_transform_info"); + +#ifdef PNG_READ_EXPAND_SUPPORTED + if ((png_ptr->transformations & PNG_EXPAND) != 0) + { + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + /* This check must match what actually happens in + * png_do_expand_palette; if it ever checks the tRNS chunk to see if + * it is all opaque we must do the same (at present it does not.) + */ + if (png_ptr->num_trans > 0) + info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; + + else + info_ptr->color_type = PNG_COLOR_TYPE_RGB; + + info_ptr->bit_depth = 8; + info_ptr->num_trans = 0; + + if (png_ptr->palette == NULL) + png_error (png_ptr, "Palette is NULL in indexed image"); + } + else + { + if (png_ptr->num_trans != 0) + { + if ((png_ptr->transformations & PNG_EXPAND_tRNS) != 0) + info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; + } + if (info_ptr->bit_depth < 8) + info_ptr->bit_depth = 8; + + info_ptr->num_trans = 0; + } + } +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) + /* The following is almost certainly wrong unless the background value is in + * the screen space! + */ + if ((png_ptr->transformations & PNG_COMPOSE) != 0) + info_ptr->background = png_ptr->background; +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED + /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4), + * however it seems that the code in png_init_read_transformations, which has + * been called before this from png_read_update_info->png_read_start_row + * sometimes does the gamma transform and cancels the flag. + * + * TODO: this looks wrong; the info_ptr should end up with a gamma equal to + * the screen_gamma value. The following probably results in weirdness if + * the info_ptr is used by the app after the rows have been read. + */ + info_ptr->colorspace.gamma = png_ptr->colorspace.gamma; +#endif + + if (info_ptr->bit_depth == 16) + { +# ifdef PNG_READ_16BIT_SUPPORTED +# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0) + info_ptr->bit_depth = 8; +# endif + +# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + if ((png_ptr->transformations & PNG_16_TO_8) != 0) + info_ptr->bit_depth = 8; +# endif + +# else + /* No 16-bit support: force chopping 16-bit input down to 8, in this case + * the app program can chose if both APIs are available by setting the + * correct scaling to use. + */ +# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + /* For compatibility with previous versions use the strip method by + * default. This code works because if PNG_SCALE_16_TO_8 is already + * set the code below will do that in preference to the chop. + */ + png_ptr->transformations |= PNG_16_TO_8; + info_ptr->bit_depth = 8; +# else + +# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + png_ptr->transformations |= PNG_SCALE_16_TO_8; + info_ptr->bit_depth = 8; +# else + + CONFIGURATION ERROR: you must enable at least one 16 to 8 method +# endif +# endif +#endif /* !READ_16BIT */ + } + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0) + info_ptr->color_type = (png_byte)(info_ptr->color_type | + PNG_COLOR_MASK_COLOR); +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) + info_ptr->color_type = (png_byte)(info_ptr->color_type & + ~PNG_COLOR_MASK_COLOR); +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + if ((png_ptr->transformations & PNG_QUANTIZE) != 0) + { + if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || + (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && + png_ptr->palette_lookup != 0 && info_ptr->bit_depth == 8) + { + info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; + } + } +#endif + +#ifdef PNG_READ_EXPAND_16_SUPPORTED + if ((png_ptr->transformations & PNG_EXPAND_16) != 0 && + info_ptr->bit_depth == 8 && + info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + { + info_ptr->bit_depth = 16; + } +#endif + +#ifdef PNG_READ_PACK_SUPPORTED + if ((png_ptr->transformations & PNG_PACK) != 0 && + (info_ptr->bit_depth < 8)) + info_ptr->bit_depth = 8; +#endif + + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + info_ptr->channels = 1; + + else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + info_ptr->channels = 3; + + else + info_ptr->channels = 1; + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0) + { + info_ptr->color_type = (png_byte)(info_ptr->color_type & + ~PNG_COLOR_MASK_ALPHA); + info_ptr->num_trans = 0; + } +#endif + + if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) + info_ptr->channels++; + +#ifdef PNG_READ_FILLER_SUPPORTED + /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */ + if ((png_ptr->transformations & PNG_FILLER) != 0 && + (info_ptr->color_type == PNG_COLOR_TYPE_RGB || + info_ptr->color_type == PNG_COLOR_TYPE_GRAY)) + { + info_ptr->channels++; + /* If adding a true alpha channel not just filler */ + if ((png_ptr->transformations & PNG_ADD_ALPHA) != 0) + info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; + } +#endif + +#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \ +defined(PNG_READ_USER_TRANSFORM_SUPPORTED) + if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) + { + if (png_ptr->user_transform_depth != 0) + info_ptr->bit_depth = png_ptr->user_transform_depth; + + if (png_ptr->user_transform_channels != 0) + info_ptr->channels = png_ptr->user_transform_channels; + } +#endif + + info_ptr->pixel_depth = (png_byte)(info_ptr->channels * + info_ptr->bit_depth); + + info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width); + + /* Adding in 1.5.4: cache the above value in png_struct so that we can later + * check in png_rowbytes that the user buffer won't get overwritten. Note + * that the field is not always set - if png_read_update_info isn't called + * the application has to either not do any transforms or get the calculation + * right itself. + */ + png_ptr->info_rowbytes = info_ptr->rowbytes; + +#ifndef PNG_READ_EXPAND_SUPPORTED + if (png_ptr != NULL) + return; +#endif +} + +#ifdef PNG_READ_PACK_SUPPORTED +/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, + * without changing the actual values. Thus, if you had a row with + * a bit depth of 1, you would end up with bytes that only contained + * the numbers 0 or 1. If you would rather they contain 0 and 255, use + * png_do_shift() after this. + */ +static void +png_do_unpack(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_unpack"); + + if (row_info->bit_depth < 8) + { + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + switch (row_info->bit_depth) + { + case 1: + { + png_bytep sp = row + (size_t)((row_width - 1) >> 3); + png_bytep dp = row + (size_t)row_width - 1; + png_uint_32 shift = 7U - ((row_width + 7U) & 0x07); + for (i = 0; i < row_width; i++) + { + *dp = (png_byte)((*sp >> shift) & 0x01); + + if (shift == 7) + { + shift = 0; + sp--; + } + + else + shift++; + + dp--; + } + break; + } + + case 2: + { + + png_bytep sp = row + (size_t)((row_width - 1) >> 2); + png_bytep dp = row + (size_t)row_width - 1; + png_uint_32 shift = ((3U - ((row_width + 3U) & 0x03)) << 1); + for (i = 0; i < row_width; i++) + { + *dp = (png_byte)((*sp >> shift) & 0x03); + + if (shift == 6) + { + shift = 0; + sp--; + } + + else + shift += 2; + + dp--; + } + break; + } + + case 4: + { + png_bytep sp = row + (size_t)((row_width - 1) >> 1); + png_bytep dp = row + (size_t)row_width - 1; + png_uint_32 shift = ((1U - ((row_width + 1U) & 0x01)) << 2); + for (i = 0; i < row_width; i++) + { + *dp = (png_byte)((*sp >> shift) & 0x0f); + + if (shift == 4) + { + shift = 0; + sp--; + } + + else + shift = 4; + + dp--; + } + break; + } + + default: + break; + } + row_info->bit_depth = 8; + row_info->pixel_depth = (png_byte)(8 * row_info->channels); + row_info->rowbytes = row_width * row_info->channels; + } +} +#endif + +#ifdef PNG_READ_SHIFT_SUPPORTED +/* Reverse the effects of png_do_shift. This routine merely shifts the + * pixels back to their significant bits values. Thus, if you have + * a row of bit depth 8, but only 5 are significant, this will shift + * the values back to 0 through 31. + */ +static void +png_do_unshift(png_row_infop row_info, png_bytep row, + png_const_color_8p sig_bits) +{ + int color_type; + + png_debug(1, "in png_do_unshift"); + + /* The palette case has already been handled in the _init routine. */ + color_type = row_info->color_type; + + if (color_type != PNG_COLOR_TYPE_PALETTE) + { + int shift[4]; + int channels = 0; + int bit_depth = row_info->bit_depth; + + if ((color_type & PNG_COLOR_MASK_COLOR) != 0) + { + shift[channels++] = bit_depth - sig_bits->red; + shift[channels++] = bit_depth - sig_bits->green; + shift[channels++] = bit_depth - sig_bits->blue; + } + + else + { + shift[channels++] = bit_depth - sig_bits->gray; + } + + if ((color_type & PNG_COLOR_MASK_ALPHA) != 0) + { + shift[channels++] = bit_depth - sig_bits->alpha; + } + + { + int c, have_shift; + + for (c = have_shift = 0; c < channels; ++c) + { + /* A shift of more than the bit depth is an error condition but it + * gets ignored here. + */ + if (shift[c] <= 0 || shift[c] >= bit_depth) + shift[c] = 0; + + else + have_shift = 1; + } + + if (have_shift == 0) + return; + } + + switch (bit_depth) + { + default: + /* Must be 1bpp gray: should not be here! */ + /* NOTREACHED */ + break; + + case 2: + /* Must be 2bpp gray */ + /* assert(channels == 1 && shift[0] == 1) */ + { + png_bytep bp = row; + png_bytep bp_end = bp + row_info->rowbytes; + + while (bp < bp_end) + { + int b = (*bp >> 1) & 0x55; + *bp++ = (png_byte)b; + } + break; + } + + case 4: + /* Must be 4bpp gray */ + /* assert(channels == 1) */ + { + png_bytep bp = row; + png_bytep bp_end = bp + row_info->rowbytes; + int gray_shift = shift[0]; + int mask = 0xf >> gray_shift; + + mask |= mask << 4; + + while (bp < bp_end) + { + int b = (*bp >> gray_shift) & mask; + *bp++ = (png_byte)b; + } + break; + } + + case 8: + /* Single byte components, G, GA, RGB, RGBA */ + { + png_bytep bp = row; + png_bytep bp_end = bp + row_info->rowbytes; + int channel = 0; + + while (bp < bp_end) + { + int b = *bp >> shift[channel]; + if (++channel >= channels) + channel = 0; + *bp++ = (png_byte)b; + } + break; + } + +#ifdef PNG_READ_16BIT_SUPPORTED + case 16: + /* Double byte components, G, GA, RGB, RGBA */ + { + png_bytep bp = row; + png_bytep bp_end = bp + row_info->rowbytes; + int channel = 0; + + while (bp < bp_end) + { + int value = (bp[0] << 8) + bp[1]; + + value >>= shift[channel]; + if (++channel >= channels) + channel = 0; + *bp++ = (png_byte)(value >> 8); + *bp++ = (png_byte)value; + } + break; + } +#endif + } + } +} +#endif + +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED +/* Scale rows of bit depth 16 down to 8 accurately */ +static void +png_do_scale_16_to_8(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_scale_16_to_8"); + + if (row_info->bit_depth == 16) + { + png_bytep sp = row; /* source */ + png_bytep dp = row; /* destination */ + png_bytep ep = sp + row_info->rowbytes; /* end+1 */ + + while (sp < ep) + { + /* The input is an array of 16-bit components, these must be scaled to + * 8 bits each. For a 16-bit value V the required value (from the PNG + * specification) is: + * + * (V * 255) / 65535 + * + * This reduces to round(V / 257), or floor((V + 128.5)/257) + * + * Represent V as the two byte value vhi.vlo. Make a guess that the + * result is the top byte of V, vhi, then the correction to this value + * is: + * + * error = floor(((V-vhi.vhi) + 128.5) / 257) + * = floor(((vlo-vhi) + 128.5) / 257) + * + * This can be approximated using integer arithmetic (and a signed + * shift): + * + * error = (vlo-vhi+128) >> 8; + * + * The approximate differs from the exact answer only when (vlo-vhi) is + * 128; it then gives a correction of +1 when the exact correction is + * 0. This gives 128 errors. The exact answer (correct for all 16-bit + * input values) is: + * + * error = (vlo-vhi+128)*65535 >> 24; + * + * An alternative arithmetic calculation which also gives no errors is: + * + * (V * 255 + 32895) >> 16 + */ + + png_int_32 tmp = *sp++; /* must be signed! */ + tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24; + *dp++ = (png_byte)tmp; + } + + row_info->bit_depth = 8; + row_info->pixel_depth = (png_byte)(8 * row_info->channels); + row_info->rowbytes = row_info->width * row_info->channels; + } +} +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED +static void +/* Simply discard the low byte. This was the default behavior prior + * to libpng-1.5.4. + */ +png_do_chop(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_chop"); + + if (row_info->bit_depth == 16) + { + png_bytep sp = row; /* source */ + png_bytep dp = row; /* destination */ + png_bytep ep = sp + row_info->rowbytes; /* end+1 */ + + while (sp < ep) + { + *dp++ = *sp; + sp += 2; /* skip low byte */ + } + + row_info->bit_depth = 8; + row_info->pixel_depth = (png_byte)(8 * row_info->channels); + row_info->rowbytes = row_info->width * row_info->channels; + } +} +#endif + +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED +static void +png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) +{ + png_uint_32 row_width = row_info->width; + + png_debug(1, "in png_do_read_swap_alpha"); + + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + /* This converts from RGBA to ARGB */ + if (row_info->bit_depth == 8) + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_byte save; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + save = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + /* This converts from RRGGBBAA to AARRGGBB */ + else + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_byte save[2]; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + save[0] = *(--sp); + save[1] = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save[0]; + *(--dp) = save[1]; + } + } +#endif + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + /* This converts from GA to AG */ + if (row_info->bit_depth == 8) + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_byte save; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + save = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + /* This converts from GGAA to AAGG */ + else + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_byte save[2]; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + save[0] = *(--sp); + save[1] = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save[0]; + *(--dp) = save[1]; + } + } +#endif + } +} +#endif + +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED +static void +png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) +{ + png_uint_32 row_width; + png_debug(1, "in png_do_read_invert_alpha"); + + row_width = row_info->width; + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This inverts the alpha channel in RGBA */ + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + *(--dp) = (png_byte)(255 - *(--sp)); + +/* This does nothing: + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + We can replace it with: +*/ + sp-=3; + dp=sp; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + /* This inverts the alpha channel in RRGGBBAA */ + else + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + *(--dp) = (png_byte)(255 - *(--sp)); + *(--dp) = (png_byte)(255 - *(--sp)); + +/* This does nothing: + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + We can replace it with: +*/ + sp-=6; + dp=sp; + } + } +#endif + } + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This inverts the alpha channel in GA */ + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + *(--dp) = (png_byte)(255 - *(--sp)); + *(--dp) = *(--sp); + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + else + { + /* This inverts the alpha channel in GGAA */ + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + *(--dp) = (png_byte)(255 - *(--sp)); + *(--dp) = (png_byte)(255 - *(--sp)); +/* + *(--dp) = *(--sp); + *(--dp) = *(--sp); +*/ + sp-=2; + dp=sp; + } + } +#endif + } +} +#endif + +#ifdef PNG_READ_FILLER_SUPPORTED +/* Add filler channel if we have RGB color */ +static void +png_do_read_filler(png_row_infop row_info, png_bytep row, + png_uint_32 filler, png_uint_32 flags) +{ + png_uint_32 i; + png_uint_32 row_width = row_info->width; + +#ifdef PNG_READ_16BIT_SUPPORTED + png_byte hi_filler = (png_byte)(filler>>8); +#endif + png_byte lo_filler = (png_byte)filler; + + png_debug(1, "in png_do_read_filler"); + + if ( + row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + if (row_info->bit_depth == 8) + { + if ((flags & PNG_FLAG_FILLER_AFTER) != 0) + { + /* This changes the data from G to GX */ + png_bytep sp = row + (size_t)row_width; + png_bytep dp = sp + (size_t)row_width; + for (i = 1; i < row_width; i++) + { + *(--dp) = lo_filler; + *(--dp) = *(--sp); + } + *(--dp) = lo_filler; + row_info->channels = 2; + row_info->pixel_depth = 16; + row_info->rowbytes = row_width * 2; + } + + else + { + /* This changes the data from G to XG */ + png_bytep sp = row + (size_t)row_width; + png_bytep dp = sp + (size_t)row_width; + for (i = 0; i < row_width; i++) + { + *(--dp) = *(--sp); + *(--dp) = lo_filler; + } + row_info->channels = 2; + row_info->pixel_depth = 16; + row_info->rowbytes = row_width * 2; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + if ((flags & PNG_FLAG_FILLER_AFTER) != 0) + { + /* This changes the data from GG to GGXX */ + png_bytep sp = row + (size_t)row_width * 2; + png_bytep dp = sp + (size_t)row_width * 2; + for (i = 1; i < row_width; i++) + { + *(--dp) = lo_filler; + *(--dp) = hi_filler; + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + *(--dp) = lo_filler; + *(--dp) = hi_filler; + row_info->channels = 2; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + } + + else + { + /* This changes the data from GG to XXGG */ + png_bytep sp = row + (size_t)row_width * 2; + png_bytep dp = sp + (size_t)row_width * 2; + for (i = 0; i < row_width; i++) + { + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = lo_filler; + *(--dp) = hi_filler; + } + row_info->channels = 2; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + } + } +#endif + } /* COLOR_TYPE == GRAY */ + else if (row_info->color_type == PNG_COLOR_TYPE_RGB) + { + if (row_info->bit_depth == 8) + { + if ((flags & PNG_FLAG_FILLER_AFTER) != 0) + { + /* This changes the data from RGB to RGBX */ + png_bytep sp = row + (size_t)row_width * 3; + png_bytep dp = sp + (size_t)row_width; + for (i = 1; i < row_width; i++) + { + *(--dp) = lo_filler; + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + *(--dp) = lo_filler; + row_info->channels = 4; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + } + + else + { + /* This changes the data from RGB to XRGB */ + png_bytep sp = row + (size_t)row_width * 3; + png_bytep dp = sp + (size_t)row_width; + for (i = 0; i < row_width; i++) + { + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = lo_filler; + } + row_info->channels = 4; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + if ((flags & PNG_FLAG_FILLER_AFTER) != 0) + { + /* This changes the data from RRGGBB to RRGGBBXX */ + png_bytep sp = row + (size_t)row_width * 6; + png_bytep dp = sp + (size_t)row_width * 2; + for (i = 1; i < row_width; i++) + { + *(--dp) = lo_filler; + *(--dp) = hi_filler; + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + *(--dp) = lo_filler; + *(--dp) = hi_filler; + row_info->channels = 4; + row_info->pixel_depth = 64; + row_info->rowbytes = row_width * 8; + } + + else + { + /* This changes the data from RRGGBB to XXRRGGBB */ + png_bytep sp = row + (size_t)row_width * 6; + png_bytep dp = sp + (size_t)row_width * 2; + for (i = 0; i < row_width; i++) + { + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = lo_filler; + *(--dp) = hi_filler; + } + + row_info->channels = 4; + row_info->pixel_depth = 64; + row_info->rowbytes = row_width * 8; + } + } +#endif + } /* COLOR_TYPE == RGB */ +} +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +/* Expand grayscale files to RGB, with or without alpha */ +static void +png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) +{ + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + png_debug(1, "in png_do_gray_to_rgb"); + + if (row_info->bit_depth >= 8 && + (row_info->color_type & PNG_COLOR_MASK_COLOR) == 0) + { + if (row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + if (row_info->bit_depth == 8) + { + /* This changes G to RGB */ + png_bytep sp = row + (size_t)row_width - 1; + png_bytep dp = sp + (size_t)row_width * 2; + for (i = 0; i < row_width; i++) + { + *(dp--) = *sp; + *(dp--) = *sp; + *(dp--) = *(sp--); + } + } + + else + { + /* This changes GG to RRGGBB */ + png_bytep sp = row + (size_t)row_width * 2 - 1; + png_bytep dp = sp + (size_t)row_width * 4; + for (i = 0; i < row_width; i++) + { + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *(sp--); + *(dp--) = *(sp--); + } + } + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This changes GA to RGBA */ + png_bytep sp = row + (size_t)row_width * 2 - 1; + png_bytep dp = sp + (size_t)row_width * 2; + for (i = 0; i < row_width; i++) + { + *(dp--) = *(sp--); + *(dp--) = *sp; + *(dp--) = *sp; + *(dp--) = *(sp--); + } + } + + else + { + /* This changes GGAA to RRGGBBAA */ + png_bytep sp = row + (size_t)row_width * 4 - 1; + png_bytep dp = sp + (size_t)row_width * 4; + for (i = 0; i < row_width; i++) + { + *(dp--) = *(sp--); + *(dp--) = *(sp--); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *(sp--); + *(dp--) = *(sp--); + } + } + } + row_info->channels = (png_byte)(row_info->channels + 2); + row_info->color_type |= PNG_COLOR_MASK_COLOR; + row_info->pixel_depth = (png_byte)(row_info->channels * + row_info->bit_depth); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } +} +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +/* Reduce RGB files to grayscale, with or without alpha + * using the equation given in Poynton's ColorFAQ of 1998-01-04 at + * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008 but + * versions dated 1998 through November 2002 have been archived at + * https://web.archive.org/web/20000816232553/www.inforamp.net/ + * ~poynton/notes/colour_and_gamma/ColorFAQ.txt ) + * Charles Poynton poynton at poynton.com + * + * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B + * + * which can be expressed with integers as + * + * Y = (6969 * R + 23434 * G + 2365 * B)/32768 + * + * Poynton's current link (as of January 2003 through July 2011): + * <http://www.poynton.com/notes/colour_and_gamma/> + * has changed the numbers slightly: + * + * Y = 0.2126*R + 0.7152*G + 0.0722*B + * + * which can be expressed with integers as + * + * Y = (6966 * R + 23436 * G + 2366 * B)/32768 + * + * Historically, however, libpng uses numbers derived from the ITU-R Rec 709 + * end point chromaticities and the D65 white point. Depending on the + * precision used for the D65 white point this produces a variety of different + * numbers, however if the four decimal place value used in ITU-R Rec 709 is + * used (0.3127,0.3290) the Y calculation would be: + * + * Y = (6968 * R + 23435 * G + 2366 * B)/32768 + * + * While this is correct the rounding results in an overflow for white, because + * the sum of the rounded coefficients is 32769, not 32768. Consequently + * libpng uses, instead, the closest non-overflowing approximation: + * + * Y = (6968 * R + 23434 * G + 2366 * B)/32768 + * + * Starting with libpng-1.5.5, if the image being converted has a cHRM chunk + * (including an sRGB chunk) then the chromaticities are used to calculate the + * coefficients. See the chunk handling in pngrutil.c for more information. + * + * In all cases the calculation is to be done in a linear colorspace. If no + * gamma information is available to correct the encoding of the original RGB + * values this results in an implicit assumption that the original PNG RGB + * values were linear. + * + * Other integer coefficients can be used via png_set_rgb_to_gray(). Because + * the API takes just red and green coefficients the blue coefficient is + * calculated to make the sum 32768. This will result in different rounding + * to that used above. + */ +static int +png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row) +{ + int rgb_error = 0; + + png_debug(1, "in png_do_rgb_to_gray"); + + if ((row_info->color_type & PNG_COLOR_MASK_PALETTE) == 0 && + (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; + png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; + png_uint_32 bc = 32768 - rc - gc; + png_uint_32 row_width = row_info->width; + int have_alpha = (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0; + + if (row_info->bit_depth == 8) + { +#ifdef PNG_READ_GAMMA_SUPPORTED + /* Notice that gamma to/from 1 are not necessarily inverses (if + * there is an overall gamma correction). Prior to 1.5.5 this code + * checked the linearized values for equality; this doesn't match + * the documentation, the original values must be checked. + */ + if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + png_byte red = *(sp++); + png_byte green = *(sp++); + png_byte blue = *(sp++); + + if (red != green || red != blue) + { + red = png_ptr->gamma_to_1[red]; + green = png_ptr->gamma_to_1[green]; + blue = png_ptr->gamma_to_1[blue]; + + rgb_error |= 1; + *(dp++) = png_ptr->gamma_from_1[ + (rc*red + gc*green + bc*blue + 16384)>>15]; + } + + else + { + /* If there is no overall correction the table will not be + * set. + */ + if (png_ptr->gamma_table != NULL) + red = png_ptr->gamma_table[red]; + + *(dp++) = red; + } + + if (have_alpha != 0) + *(dp++) = *(sp++); + } + } + else +#endif + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + png_byte red = *(sp++); + png_byte green = *(sp++); + png_byte blue = *(sp++); + + if (red != green || red != blue) + { + rgb_error |= 1; + /* NOTE: this is the historical approach which simply + * truncates the results. + */ + *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); + } + + else + *(dp++) = red; + + if (have_alpha != 0) + *(dp++) = *(sp++); + } + } + } + + else /* RGB bit_depth == 16 */ + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL) + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + png_uint_16 red, green, blue, w; + png_byte hi,lo; + + hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo)); + hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo)); + hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo)); + + if (red == green && red == blue) + { + if (png_ptr->gamma_16_table != NULL) + w = png_ptr->gamma_16_table[(red & 0xff) + >> png_ptr->gamma_shift][red >> 8]; + + else + w = red; + } + + else + { + png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red & 0xff) + >> png_ptr->gamma_shift][red>>8]; + png_uint_16 green_1 = + png_ptr->gamma_16_to_1[(green & 0xff) >> + png_ptr->gamma_shift][green>>8]; + png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue & 0xff) + >> png_ptr->gamma_shift][blue>>8]; + png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 + + bc*blue_1 + 16384)>>15); + w = png_ptr->gamma_16_from_1[(gray16 & 0xff) >> + png_ptr->gamma_shift][gray16 >> 8]; + rgb_error |= 1; + } + + *(dp++) = (png_byte)((w>>8) & 0xff); + *(dp++) = (png_byte)(w & 0xff); + + if (have_alpha != 0) + { + *(dp++) = *(sp++); + *(dp++) = *(sp++); + } + } + } + else +#endif + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + png_uint_16 red, green, blue, gray16; + png_byte hi,lo; + + hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo)); + hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo)); + hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo)); + + if (red != green || red != blue) + rgb_error |= 1; + + /* From 1.5.5 in the 16-bit case do the accurate conversion even + * in the 'fast' case - this is because this is where the code + * ends up when handling linear 16-bit data. + */ + gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >> + 15); + *(dp++) = (png_byte)((gray16 >> 8) & 0xff); + *(dp++) = (png_byte)(gray16 & 0xff); + + if (have_alpha != 0) + { + *(dp++) = *(sp++); + *(dp++) = *(sp++); + } + } + } + } + + row_info->channels = (png_byte)(row_info->channels - 2); + row_info->color_type = (png_byte)(row_info->color_type & + ~PNG_COLOR_MASK_COLOR); + row_info->pixel_depth = (png_byte)(row_info->channels * + row_info->bit_depth); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } + return rgb_error; +} +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) +/* Replace any alpha or transparency with the supplied background color. + * "background" is already in the screen gamma, while "background_1" is + * at a gamma of 1.0. Paletted files have already been taken care of. + */ +static void +png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr) +{ +#ifdef PNG_READ_GAMMA_SUPPORTED + png_const_bytep gamma_table = png_ptr->gamma_table; + png_const_bytep gamma_from_1 = png_ptr->gamma_from_1; + png_const_bytep gamma_to_1 = png_ptr->gamma_to_1; + png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table; + png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1; + png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1; + int gamma_shift = png_ptr->gamma_shift; + int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0; +#endif + + png_bytep sp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + int shift; + + png_debug(1, "in png_do_compose"); + + switch (row_info->color_type) + { + case PNG_COLOR_TYPE_GRAY: + { + switch (row_info->bit_depth) + { + case 1: + { + sp = row; + shift = 7; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x01) + == png_ptr->trans_color.gray) + { + unsigned int tmp = *sp & (0x7f7f >> (7 - shift)); + tmp |= + (unsigned int)(png_ptr->background.gray << shift); + *sp = (png_byte)(tmp & 0xff); + } + + if (shift == 0) + { + shift = 7; + sp++; + } + + else + shift--; + } + break; + } + + case 2: + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_table != NULL) + { + sp = row; + shift = 6; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x03) + == png_ptr->trans_color.gray) + { + unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); + tmp |= + (unsigned int)png_ptr->background.gray << shift; + *sp = (png_byte)(tmp & 0xff); + } + + else + { + unsigned int p = (*sp >> shift) & 0x03; + unsigned int g = (gamma_table [p | (p << 2) | + (p << 4) | (p << 6)] >> 6) & 0x03; + unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); + tmp |= (unsigned int)(g << shift); + *sp = (png_byte)(tmp & 0xff); + } + + if (shift == 0) + { + shift = 6; + sp++; + } + + else + shift -= 2; + } + } + + else +#endif + { + sp = row; + shift = 6; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x03) + == png_ptr->trans_color.gray) + { + unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); + tmp |= + (unsigned int)png_ptr->background.gray << shift; + *sp = (png_byte)(tmp & 0xff); + } + + if (shift == 0) + { + shift = 6; + sp++; + } + + else + shift -= 2; + } + } + break; + } + + case 4: + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_table != NULL) + { + sp = row; + shift = 4; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x0f) + == png_ptr->trans_color.gray) + { + unsigned int tmp = *sp & (0x0f0f >> (4 - shift)); + tmp |= + (unsigned int)(png_ptr->background.gray << shift); + *sp = (png_byte)(tmp & 0xff); + } + + else + { + unsigned int p = (*sp >> shift) & 0x0f; + unsigned int g = (gamma_table[p | (p << 4)] >> 4) & + 0x0f; + unsigned int tmp = *sp & (0x0f0f >> (4 - shift)); + tmp |= (unsigned int)(g << shift); + *sp = (png_byte)(tmp & 0xff); + } + + if (shift == 0) + { + shift = 4; + sp++; + } + + else + shift -= 4; + } + } + + else +#endif + { + sp = row; + shift = 4; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x0f) + == png_ptr->trans_color.gray) + { + unsigned int tmp = *sp & (0x0f0f >> (4 - shift)); + tmp |= + (unsigned int)(png_ptr->background.gray << shift); + *sp = (png_byte)(tmp & 0xff); + } + + if (shift == 0) + { + shift = 4; + sp++; + } + + else + shift -= 4; + } + } + break; + } + + case 8: + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_table != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp++) + { + if (*sp == png_ptr->trans_color.gray) + *sp = (png_byte)png_ptr->background.gray; + + else + *sp = gamma_table[*sp]; + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp++) + { + if (*sp == png_ptr->trans_color.gray) + *sp = (png_byte)png_ptr->background.gray; + } + } + break; + } + + case 16: + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_16 != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 2) + { + png_uint_16 v; + + v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + + if (v == png_ptr->trans_color.gray) + { + /* Background is already in screen gamma */ + *sp = (png_byte)((png_ptr->background.gray >> 8) + & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.gray + & 0xff); + } + + else + { + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + } + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 2) + { + png_uint_16 v; + + v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + + if (v == png_ptr->trans_color.gray) + { + *sp = (png_byte)((png_ptr->background.gray >> 8) + & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.gray + & 0xff); + } + } + } + break; + } + + default: + break; + } + break; + } + + case PNG_COLOR_TYPE_RGB: + { + if (row_info->bit_depth == 8) + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_table != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 3) + { + if (*sp == png_ptr->trans_color.red && + *(sp + 1) == png_ptr->trans_color.green && + *(sp + 2) == png_ptr->trans_color.blue) + { + *sp = (png_byte)png_ptr->background.red; + *(sp + 1) = (png_byte)png_ptr->background.green; + *(sp + 2) = (png_byte)png_ptr->background.blue; + } + + else + { + *sp = gamma_table[*sp]; + *(sp + 1) = gamma_table[*(sp + 1)]; + *(sp + 2) = gamma_table[*(sp + 2)]; + } + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 3) + { + if (*sp == png_ptr->trans_color.red && + *(sp + 1) == png_ptr->trans_color.green && + *(sp + 2) == png_ptr->trans_color.blue) + { + *sp = (png_byte)png_ptr->background.red; + *(sp + 1) = (png_byte)png_ptr->background.green; + *(sp + 2) = (png_byte)png_ptr->background.blue; + } + } + } + } + else /* if (row_info->bit_depth == 16) */ + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_16 != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 6) + { + png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + + png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + + png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) + + *(sp + 5)); + + if (r == png_ptr->trans_color.red && + g == png_ptr->trans_color.green && + b == png_ptr->trans_color.blue) + { + /* Background is already in screen gamma */ + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) + & 0xff); + *(sp + 3) = (png_byte)(png_ptr->background.green + & 0xff); + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) + & 0xff); + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); + } + + else + { + png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + + v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; + *(sp + 2) = (png_byte)((v >> 8) & 0xff); + *(sp + 3) = (png_byte)(v & 0xff); + + v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; + *(sp + 4) = (png_byte)((v >> 8) & 0xff); + *(sp + 5) = (png_byte)(v & 0xff); + } + } + } + + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 6) + { + png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + + png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + + png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) + + *(sp + 5)); + + if (r == png_ptr->trans_color.red && + g == png_ptr->trans_color.green && + b == png_ptr->trans_color.blue) + { + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) + & 0xff); + *(sp + 3) = (png_byte)(png_ptr->background.green + & 0xff); + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) + & 0xff); + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); + } + } + } + } + break; + } + + case PNG_COLOR_TYPE_GRAY_ALPHA: + { + if (row_info->bit_depth == 8) + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_to_1 != NULL && gamma_from_1 != NULL && + gamma_table != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 2) + { + png_uint_16 a = *(sp + 1); + + if (a == 0xff) + *sp = gamma_table[*sp]; + + else if (a == 0) + { + /* Background is already in screen gamma */ + *sp = (png_byte)png_ptr->background.gray; + } + + else + { + png_byte v, w; + + v = gamma_to_1[*sp]; + png_composite(w, v, a, png_ptr->background_1.gray); + if (optimize == 0) + w = gamma_from_1[w]; + *sp = w; + } + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 2) + { + png_byte a = *(sp + 1); + + if (a == 0) + *sp = (png_byte)png_ptr->background.gray; + + else if (a < 0xff) + png_composite(*sp, *sp, a, png_ptr->background.gray); + } + } + } + else /* if (png_ptr->bit_depth == 16) */ + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_16 != NULL && gamma_16_from_1 != NULL && + gamma_16_to_1 != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 4) + { + png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + + if (a == (png_uint_16)0xffff) + { + png_uint_16 v; + + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + } + + else if (a == 0) + { + /* Background is already in screen gamma */ + *sp = (png_byte)((png_ptr->background.gray >> 8) + & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); + } + + else + { + png_uint_16 g, v, w; + + g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; + png_composite_16(v, g, a, png_ptr->background_1.gray); + if (optimize != 0) + w = v; + else + w = gamma_16_from_1[(v & 0xff) >> + gamma_shift][v >> 8]; + *sp = (png_byte)((w >> 8) & 0xff); + *(sp + 1) = (png_byte)(w & 0xff); + } + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 4) + { + png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + + if (a == 0) + { + *sp = (png_byte)((png_ptr->background.gray >> 8) + & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); + } + + else if (a < 0xffff) + { + png_uint_16 g, v; + + g = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + png_composite_16(v, g, a, png_ptr->background.gray); + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + } + } + } + } + break; + } + + case PNG_COLOR_TYPE_RGB_ALPHA: + { + if (row_info->bit_depth == 8) + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_to_1 != NULL && gamma_from_1 != NULL && + gamma_table != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 4) + { + png_byte a = *(sp + 3); + + if (a == 0xff) + { + *sp = gamma_table[*sp]; + *(sp + 1) = gamma_table[*(sp + 1)]; + *(sp + 2) = gamma_table[*(sp + 2)]; + } + + else if (a == 0) + { + /* Background is already in screen gamma */ + *sp = (png_byte)png_ptr->background.red; + *(sp + 1) = (png_byte)png_ptr->background.green; + *(sp + 2) = (png_byte)png_ptr->background.blue; + } + + else + { + png_byte v, w; + + v = gamma_to_1[*sp]; + png_composite(w, v, a, png_ptr->background_1.red); + if (optimize == 0) w = gamma_from_1[w]; + *sp = w; + + v = gamma_to_1[*(sp + 1)]; + png_composite(w, v, a, png_ptr->background_1.green); + if (optimize == 0) w = gamma_from_1[w]; + *(sp + 1) = w; + + v = gamma_to_1[*(sp + 2)]; + png_composite(w, v, a, png_ptr->background_1.blue); + if (optimize == 0) w = gamma_from_1[w]; + *(sp + 2) = w; + } + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 4) + { + png_byte a = *(sp + 3); + + if (a == 0) + { + *sp = (png_byte)png_ptr->background.red; + *(sp + 1) = (png_byte)png_ptr->background.green; + *(sp + 2) = (png_byte)png_ptr->background.blue; + } + + else if (a < 0xff) + { + png_composite(*sp, *sp, a, png_ptr->background.red); + + png_composite(*(sp + 1), *(sp + 1), a, + png_ptr->background.green); + + png_composite(*(sp + 2), *(sp + 2), a, + png_ptr->background.blue); + } + } + } + } + else /* if (row_info->bit_depth == 16) */ + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_16 != NULL && gamma_16_from_1 != NULL && + gamma_16_to_1 != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 8) + { + png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) + << 8) + (png_uint_16)(*(sp + 7))); + + if (a == (png_uint_16)0xffff) + { + png_uint_16 v; + + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + + v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; + *(sp + 2) = (png_byte)((v >> 8) & 0xff); + *(sp + 3) = (png_byte)(v & 0xff); + + v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; + *(sp + 4) = (png_byte)((v >> 8) & 0xff); + *(sp + 5) = (png_byte)(v & 0xff); + } + + else if (a == 0) + { + /* Background is already in screen gamma */ + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) + & 0xff); + *(sp + 3) = (png_byte)(png_ptr->background.green + & 0xff); + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) + & 0xff); + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); + } + + else + { + png_uint_16 v, w; + + v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; + png_composite_16(w, v, a, png_ptr->background_1.red); + if (optimize == 0) + w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >> + 8]; + *sp = (png_byte)((w >> 8) & 0xff); + *(sp + 1) = (png_byte)(w & 0xff); + + v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; + png_composite_16(w, v, a, png_ptr->background_1.green); + if (optimize == 0) + w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >> + 8]; + + *(sp + 2) = (png_byte)((w >> 8) & 0xff); + *(sp + 3) = (png_byte)(w & 0xff); + + v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; + png_composite_16(w, v, a, png_ptr->background_1.blue); + if (optimize == 0) + w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >> + 8]; + + *(sp + 4) = (png_byte)((w >> 8) & 0xff); + *(sp + 5) = (png_byte)(w & 0xff); + } + } + } + + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 8) + { + png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) + << 8) + (png_uint_16)(*(sp + 7))); + + if (a == 0) + { + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) + & 0xff); + *(sp + 3) = (png_byte)(png_ptr->background.green + & 0xff); + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) + & 0xff); + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); + } + + else if (a < 0xffff) + { + png_uint_16 v; + + png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) + + *(sp + 5)); + + png_composite_16(v, r, a, png_ptr->background.red); + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + + png_composite_16(v, g, a, png_ptr->background.green); + *(sp + 2) = (png_byte)((v >> 8) & 0xff); + *(sp + 3) = (png_byte)(v & 0xff); + + png_composite_16(v, b, a, png_ptr->background.blue); + *(sp + 4) = (png_byte)((v >> 8) & 0xff); + *(sp + 5) = (png_byte)(v & 0xff); + } + } + } + } + break; + } + + default: + break; + } +} +#endif /* READ_BACKGROUND || READ_ALPHA_MODE */ + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* Gamma correct the image, avoiding the alpha channel. Make sure + * you do this after you deal with the transparency issue on grayscale + * or RGB images. If your bit depth is 8, use gamma_table, if it + * is 16, use gamma_16_table and gamma_shift. Build these with + * build_gamma_table(). + */ +static void +png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr) +{ + png_const_bytep gamma_table = png_ptr->gamma_table; + png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table; + int gamma_shift = png_ptr->gamma_shift; + + png_bytep sp; + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + png_debug(1, "in png_do_gamma"); + + if (((row_info->bit_depth <= 8 && gamma_table != NULL) || + (row_info->bit_depth == 16 && gamma_16_table != NULL))) + { + switch (row_info->color_type) + { + case PNG_COLOR_TYPE_RGB: + { + if (row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_width; i++) + { + *sp = gamma_table[*sp]; + sp++; + *sp = gamma_table[*sp]; + sp++; + *sp = gamma_table[*sp]; + sp++; + } + } + + else /* if (row_info->bit_depth == 16) */ + { + sp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 v; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + } + } + break; + } + + case PNG_COLOR_TYPE_RGB_ALPHA: + { + if (row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_width; i++) + { + *sp = gamma_table[*sp]; + sp++; + + *sp = gamma_table[*sp]; + sp++; + + *sp = gamma_table[*sp]; + sp++; + + sp++; + } + } + + else /* if (row_info->bit_depth == 16) */ + { + sp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 4; + } + } + break; + } + + case PNG_COLOR_TYPE_GRAY_ALPHA: + { + if (row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_width; i++) + { + *sp = gamma_table[*sp]; + sp += 2; + } + } + + else /* if (row_info->bit_depth == 16) */ + { + sp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 4; + } + } + break; + } + + case PNG_COLOR_TYPE_GRAY: + { + if (row_info->bit_depth == 2) + { + sp = row; + for (i = 0; i < row_width; i += 4) + { + int a = *sp & 0xc0; + int b = *sp & 0x30; + int c = *sp & 0x0c; + int d = *sp & 0x03; + + *sp = (png_byte)( + ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)| + ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)| + ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)| + ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) )); + sp++; + } + } + + if (row_info->bit_depth == 4) + { + sp = row; + for (i = 0; i < row_width; i += 2) + { + int msb = *sp & 0xf0; + int lsb = *sp & 0x0f; + + *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0) + | (((int)gamma_table[(lsb << 4) | lsb]) >> 4)); + sp++; + } + } + + else if (row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_width; i++) + { + *sp = gamma_table[*sp]; + sp++; + } + } + + else if (row_info->bit_depth == 16) + { + sp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + } + } + break; + } + + default: + break; + } + } +} +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED +/* Encode the alpha channel to the output gamma (the input channel is always + * linear.) Called only with color types that have an alpha channel. Needs the + * from_1 tables. + */ +static void +png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr) +{ + png_uint_32 row_width = row_info->width; + + png_debug(1, "in png_do_encode_alpha"); + + if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0) + { + if (row_info->bit_depth == 8) + { + png_bytep table = png_ptr->gamma_from_1; + + if (table != NULL) + { + int step = (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2; + + /* The alpha channel is the last component: */ + row += step - 1; + + for (; row_width > 0; --row_width, row += step) + *row = table[*row]; + + return; + } + } + + else if (row_info->bit_depth == 16) + { + png_uint_16pp table = png_ptr->gamma_16_from_1; + int gamma_shift = png_ptr->gamma_shift; + + if (table != NULL) + { + int step = (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4; + + /* The alpha channel is the last component: */ + row += step - 2; + + for (; row_width > 0; --row_width, row += step) + { + png_uint_16 v; + + v = table[*(row + 1) >> gamma_shift][*row]; + *row = (png_byte)((v >> 8) & 0xff); + *(row + 1) = (png_byte)(v & 0xff); + } + + return; + } + } + } + + /* Only get to here if called with a weird row_info; no harm has been done, + * so just issue a warning. + */ + png_warning(png_ptr, "png_do_encode_alpha: unexpected call"); +} +#endif + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* Expands a palette row to an RGB or RGBA row depending + * upon whether you supply trans and num_trans. + */ +static void +png_do_expand_palette(png_structrp png_ptr, png_row_infop row_info, + png_bytep row, png_const_colorp palette, png_const_bytep trans_alpha, + int num_trans) +{ + int shift, value; + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + png_debug(1, "in png_do_expand_palette"); + + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (row_info->bit_depth < 8) + { + switch (row_info->bit_depth) + { + case 1: + { + sp = row + (size_t)((row_width - 1) >> 3); + dp = row + (size_t)row_width - 1; + shift = 7 - (int)((row_width + 7) & 0x07); + for (i = 0; i < row_width; i++) + { + if ((*sp >> shift) & 0x01) + *dp = 1; + + else + *dp = 0; + + if (shift == 7) + { + shift = 0; + sp--; + } + + else + shift++; + + dp--; + } + break; + } + + case 2: + { + sp = row + (size_t)((row_width - 1) >> 2); + dp = row + (size_t)row_width - 1; + shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); + for (i = 0; i < row_width; i++) + { + value = (*sp >> shift) & 0x03; + *dp = (png_byte)value; + if (shift == 6) + { + shift = 0; + sp--; + } + + else + shift += 2; + + dp--; + } + break; + } + + case 4: + { + sp = row + (size_t)((row_width - 1) >> 1); + dp = row + (size_t)row_width - 1; + shift = (int)((row_width & 0x01) << 2); + for (i = 0; i < row_width; i++) + { + value = (*sp >> shift) & 0x0f; + *dp = (png_byte)value; + if (shift == 4) + { + shift = 0; + sp--; + } + + else + shift += 4; + + dp--; + } + break; + } + + default: + break; + } + row_info->bit_depth = 8; + row_info->pixel_depth = 8; + row_info->rowbytes = row_width; + } + + if (row_info->bit_depth == 8) + { + { + if (num_trans > 0) + { + sp = row + (size_t)row_width - 1; + dp = row + ((size_t)row_width << 2) - 1; + + i = 0; +#ifdef PNG_ARM_NEON_INTRINSICS_AVAILABLE + if (png_ptr->riffled_palette != NULL) + { + /* The RGBA optimization works with png_ptr->bit_depth == 8 + * but sometimes row_info->bit_depth has been changed to 8. + * In these cases, the palette hasn't been riffled. + */ + i = png_do_expand_palette_rgba8_neon(png_ptr, row_info, row, + &sp, &dp); + } +#else + PNG_UNUSED(png_ptr) +#endif + + for (; i < row_width; i++) + { + if ((int)(*sp) >= num_trans) + *dp-- = 0xff; + else + *dp-- = trans_alpha[*sp]; + *dp-- = palette[*sp].blue; + *dp-- = palette[*sp].green; + *dp-- = palette[*sp].red; + sp--; + } + row_info->bit_depth = 8; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + row_info->color_type = 6; + row_info->channels = 4; + } + + else + { + sp = row + (size_t)row_width - 1; + dp = row + (size_t)(row_width * 3) - 1; + i = 0; +#ifdef PNG_ARM_NEON_INTRINSICS_AVAILABLE + i = png_do_expand_palette_rgb8_neon(png_ptr, row_info, row, + &sp, &dp); +#else + PNG_UNUSED(png_ptr) +#endif + + for (; i < row_width; i++) + { + *dp-- = palette[*sp].blue; + *dp-- = palette[*sp].green; + *dp-- = palette[*sp].red; + sp--; + } + + row_info->bit_depth = 8; + row_info->pixel_depth = 24; + row_info->rowbytes = row_width * 3; + row_info->color_type = 2; + row_info->channels = 3; + } + } + } + } +} + +/* If the bit depth < 8, it is expanded to 8. Also, if the already + * expanded transparency value is supplied, an alpha channel is built. + */ +static void +png_do_expand(png_row_infop row_info, png_bytep row, + png_const_color_16p trans_color) +{ + int shift, value; + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + png_debug(1, "in png_do_expand"); + + if (row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + unsigned int gray = trans_color != NULL ? trans_color->gray : 0; + + if (row_info->bit_depth < 8) + { + switch (row_info->bit_depth) + { + case 1: + { + gray = (gray & 0x01) * 0xff; + sp = row + (size_t)((row_width - 1) >> 3); + dp = row + (size_t)row_width - 1; + shift = 7 - (int)((row_width + 7) & 0x07); + for (i = 0; i < row_width; i++) + { + if ((*sp >> shift) & 0x01) + *dp = 0xff; + + else + *dp = 0; + + if (shift == 7) + { + shift = 0; + sp--; + } + + else + shift++; + + dp--; + } + break; + } + + case 2: + { + gray = (gray & 0x03) * 0x55; + sp = row + (size_t)((row_width - 1) >> 2); + dp = row + (size_t)row_width - 1; + shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); + for (i = 0; i < row_width; i++) + { + value = (*sp >> shift) & 0x03; + *dp = (png_byte)(value | (value << 2) | (value << 4) | + (value << 6)); + if (shift == 6) + { + shift = 0; + sp--; + } + + else + shift += 2; + + dp--; + } + break; + } + + case 4: + { + gray = (gray & 0x0f) * 0x11; + sp = row + (size_t)((row_width - 1) >> 1); + dp = row + (size_t)row_width - 1; + shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); + for (i = 0; i < row_width; i++) + { + value = (*sp >> shift) & 0x0f; + *dp = (png_byte)(value | (value << 4)); + if (shift == 4) + { + shift = 0; + sp--; + } + + else + shift = 4; + + dp--; + } + break; + } + + default: + break; + } + + row_info->bit_depth = 8; + row_info->pixel_depth = 8; + row_info->rowbytes = row_width; + } + + if (trans_color != NULL) + { + if (row_info->bit_depth == 8) + { + gray = gray & 0xff; + sp = row + (size_t)row_width - 1; + dp = row + ((size_t)row_width << 1) - 1; + + for (i = 0; i < row_width; i++) + { + if ((*sp & 0xffU) == gray) + *dp-- = 0; + + else + *dp-- = 0xff; + + *dp-- = *sp--; + } + } + + else if (row_info->bit_depth == 16) + { + unsigned int gray_high = (gray >> 8) & 0xff; + unsigned int gray_low = gray & 0xff; + sp = row + row_info->rowbytes - 1; + dp = row + (row_info->rowbytes << 1) - 1; + for (i = 0; i < row_width; i++) + { + if ((*(sp - 1) & 0xffU) == gray_high && + (*(sp) & 0xffU) == gray_low) + { + *dp-- = 0; + *dp-- = 0; + } + + else + { + *dp-- = 0xff; + *dp-- = 0xff; + } + + *dp-- = *sp--; + *dp-- = *sp--; + } + } + + row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; + row_info->channels = 2; + row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, + row_width); + } + } + else if (row_info->color_type == PNG_COLOR_TYPE_RGB && + trans_color != NULL) + { + if (row_info->bit_depth == 8) + { + png_byte red = (png_byte)(trans_color->red & 0xff); + png_byte green = (png_byte)(trans_color->green & 0xff); + png_byte blue = (png_byte)(trans_color->blue & 0xff); + sp = row + (size_t)row_info->rowbytes - 1; + dp = row + ((size_t)row_width << 2) - 1; + for (i = 0; i < row_width; i++) + { + if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue) + *dp-- = 0; + + else + *dp-- = 0xff; + + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + } + } + else if (row_info->bit_depth == 16) + { + png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff); + png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff); + png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff); + png_byte red_low = (png_byte)(trans_color->red & 0xff); + png_byte green_low = (png_byte)(trans_color->green & 0xff); + png_byte blue_low = (png_byte)(trans_color->blue & 0xff); + sp = row + row_info->rowbytes - 1; + dp = row + ((size_t)row_width << 3) - 1; + for (i = 0; i < row_width; i++) + { + if (*(sp - 5) == red_high && + *(sp - 4) == red_low && + *(sp - 3) == green_high && + *(sp - 2) == green_low && + *(sp - 1) == blue_high && + *(sp ) == blue_low) + { + *dp-- = 0; + *dp-- = 0; + } + + else + { + *dp-- = 0xff; + *dp-- = 0xff; + } + + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + } + } + row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; + row_info->channels = 4; + row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } +} +#endif + +#ifdef PNG_READ_EXPAND_16_SUPPORTED +/* If the bit depth is 8 and the color type is not a palette type expand the + * whole row to 16 bits. Has no effect otherwise. + */ +static void +png_do_expand_16(png_row_infop row_info, png_bytep row) +{ + if (row_info->bit_depth == 8 && + row_info->color_type != PNG_COLOR_TYPE_PALETTE) + { + /* The row have a sequence of bytes containing [0..255] and we need + * to turn it into another row containing [0..65535], to do this we + * calculate: + * + * (input / 255) * 65535 + * + * Which happens to be exactly input * 257 and this can be achieved + * simply by byte replication in place (copying backwards). + */ + png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */ + png_byte *dp = sp + row_info->rowbytes; /* destination, end + 1 */ + while (dp > sp) + { + dp[-2] = dp[-1] = *--sp; dp -= 2; + } + + row_info->rowbytes *= 2; + row_info->bit_depth = 16; + row_info->pixel_depth = (png_byte)(row_info->channels * 16); + } +} +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +static void +png_do_quantize(png_row_infop row_info, png_bytep row, + png_const_bytep palette_lookup, png_const_bytep quantize_lookup) +{ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + png_debug(1, "in png_do_quantize"); + + if (row_info->bit_depth == 8) + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup) + { + int r, g, b, p; + sp = row; + dp = row; + for (i = 0; i < row_width; i++) + { + r = *sp++; + g = *sp++; + b = *sp++; + + /* This looks real messy, but the compiler will reduce + * it down to a reasonable formula. For example, with + * 5 bits per color, we get: + * p = (((r >> 3) & 0x1f) << 10) | + * (((g >> 3) & 0x1f) << 5) | + * ((b >> 3) & 0x1f); + */ + p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & + ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << + (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | + (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & + ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << + (PNG_QUANTIZE_BLUE_BITS)) | + ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & + ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); + + *dp++ = palette_lookup[p]; + } + + row_info->color_type = PNG_COLOR_TYPE_PALETTE; + row_info->channels = 1; + row_info->pixel_depth = row_info->bit_depth; + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && + palette_lookup != NULL) + { + int r, g, b, p; + sp = row; + dp = row; + for (i = 0; i < row_width; i++) + { + r = *sp++; + g = *sp++; + b = *sp++; + sp++; + + p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & + ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << + (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | + (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & + ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << + (PNG_QUANTIZE_BLUE_BITS)) | + ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & + ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); + + *dp++ = palette_lookup[p]; + } + + row_info->color_type = PNG_COLOR_TYPE_PALETTE; + row_info->channels = 1; + row_info->pixel_depth = row_info->bit_depth; + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } + + else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && + quantize_lookup) + { + sp = row; + + for (i = 0; i < row_width; i++, sp++) + { + *sp = quantize_lookup[*sp]; + } + } + } +} +#endif /* READ_QUANTIZE */ + +/* Transform the row. The order of transformations is significant, + * and is very touchy. If you add a transformation, take care to + * decide how it fits in with the other transformations here. + */ +void /* PRIVATE */ +png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info) +{ + png_debug(1, "in png_do_read_transformations"); + + if (png_ptr->row_buf == NULL) + { + /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this + * error is incredibly rare and incredibly easy to debug without this + * information. + */ + png_error(png_ptr, "NULL row buffer"); + } + + /* The following is debugging; prior to 1.5.4 the code was never compiled in; + * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro + * PNG_WARN_UNINITIALIZED_ROW removed. In 1.6 the new flag is set only for + * all transformations, however in practice the ROW_INIT always gets done on + * demand, if necessary. + */ + if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 && + (png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) + { + /* Application has failed to call either png_read_start_image() or + * png_read_update_info() after setting transforms that expand pixels. + * This check added to libpng-1.2.19 (but not enabled until 1.5.4). + */ + png_error(png_ptr, "Uninitialized row"); + } + +#ifdef PNG_READ_EXPAND_SUPPORTED + if ((png_ptr->transformations & PNG_EXPAND) != 0) + { + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) + { +#ifdef PNG_ARM_NEON_INTRINSICS_AVAILABLE + if ((png_ptr->num_trans > 0) && (png_ptr->bit_depth == 8)) + { + if (png_ptr->riffled_palette == NULL) + { + /* Initialize the accelerated palette expansion. */ + png_ptr->riffled_palette = + (png_bytep)png_malloc(png_ptr, 256 * 4); + png_riffle_palette_neon(png_ptr); + } + } +#endif + png_do_expand_palette(png_ptr, row_info, png_ptr->row_buf + 1, + png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans); + } + + else + { + if (png_ptr->num_trans != 0 && + (png_ptr->transformations & PNG_EXPAND_tRNS) != 0) + png_do_expand(row_info, png_ptr->row_buf + 1, + &(png_ptr->trans_color)); + + else + png_do_expand(row_info, png_ptr->row_buf + 1, NULL); + } + } +#endif + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 && + (png_ptr->transformations & PNG_COMPOSE) == 0 && + (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) + png_do_strip_channel(row_info, png_ptr->row_buf + 1, + 0 /* at_start == false, because SWAP_ALPHA happens later */); +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) + { + int rgb_error = + png_do_rgb_to_gray(png_ptr, row_info, + png_ptr->row_buf + 1); + + if (rgb_error != 0) + { + png_ptr->rgb_to_gray_status=1; + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == + PNG_RGB_TO_GRAY_WARN) + png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel"); + + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == + PNG_RGB_TO_GRAY_ERR) + png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel"); + } + } +#endif + +/* From Andreas Dilger e-mail to png-implement, 26 March 1998: + * + * In most cases, the "simple transparency" should be done prior to doing + * gray-to-RGB, or you will have to test 3x as many bytes to check if a + * pixel is transparent. You would also need to make sure that the + * transparency information is upgraded to RGB. + * + * To summarize, the current flow is: + * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite + * with background "in place" if transparent, + * convert to RGB if necessary + * - Gray + alpha -> composite with gray background and remove alpha bytes, + * convert to RGB if necessary + * + * To support RGB backgrounds for gray images we need: + * - Gray + simple transparency -> convert to RGB + simple transparency, + * compare 3 or 6 bytes and composite with + * background "in place" if transparent + * (3x compare/pixel compared to doing + * composite with gray bkgrnd) + * - Gray + alpha -> convert to RGB + alpha, composite with background and + * remove alpha bytes (3x float + * operations/pixel compared with composite + * on gray background) + * + * Greg's change will do this. The reason it wasn't done before is for + * performance, as this increases the per-pixel operations. If we would check + * in advance if the background was gray or RGB, and position the gray-to-RGB + * transform appropriately, then it would save a lot of work/time. + */ + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + /* If gray -> RGB, do so now only if background is non-gray; else do later + * for performance reasons + */ + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 && + (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) == 0) + png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) + if ((png_ptr->transformations & PNG_COMPOSE) != 0) + png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr); +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED + if ((png_ptr->transformations & PNG_GAMMA) != 0 && +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Because RGB_TO_GRAY does the gamma transform. */ + (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0 && +#endif +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) + /* Because PNG_COMPOSE does the gamma transform if there is something to + * do (if there is an alpha channel or transparency.) + */ + !((png_ptr->transformations & PNG_COMPOSE) != 0 && + ((png_ptr->num_trans != 0) || + (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)) && +#endif + /* Because png_init_read_transformations transforms the palette, unless + * RGB_TO_GRAY will do the transform. + */ + (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) + png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr); +#endif + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 && + (png_ptr->transformations & PNG_COMPOSE) != 0 && + (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) + png_do_strip_channel(row_info, png_ptr->row_buf + 1, + 0 /* at_start == false, because SWAP_ALPHA happens later */); +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + if ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 && + (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0) + png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr); +#endif + +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0) + png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + /* There is no harm in doing both of these because only one has any effect, + * by putting the 'scale' option first if the app asks for scale (either by + * calling the API or in a TRANSFORM flag) this is what happens. + */ + if ((png_ptr->transformations & PNG_16_TO_8) != 0) + png_do_chop(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + if ((png_ptr->transformations & PNG_QUANTIZE) != 0) + { + png_do_quantize(row_info, png_ptr->row_buf + 1, + png_ptr->palette_lookup, png_ptr->quantize_index); + + if (row_info->rowbytes == 0) + png_error(png_ptr, "png_do_quantize returned rowbytes=0"); + } +#endif /* READ_QUANTIZE */ + +#ifdef PNG_READ_EXPAND_16_SUPPORTED + /* Do the expansion now, after all the arithmetic has been done. Notice + * that previous transformations can handle the PNG_EXPAND_16 flag if this + * is efficient (particularly true in the case of gamma correction, where + * better accuracy results faster!) + */ + if ((png_ptr->transformations & PNG_EXPAND_16) != 0) + png_do_expand_16(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + /* NOTE: moved here in 1.5.4 (from much later in this list.) */ + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 && + (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) != 0) + png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_INVERT_SUPPORTED + if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) + png_do_invert(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0) + png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_SHIFT_SUPPORTED + if ((png_ptr->transformations & PNG_SHIFT) != 0) + png_do_unshift(row_info, png_ptr->row_buf + 1, + &(png_ptr->shift)); +#endif + +#ifdef PNG_READ_PACK_SUPPORTED + if ((png_ptr->transformations & PNG_PACK) != 0) + png_do_unpack(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Added at libpng-1.5.10 */ + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && + png_ptr->num_palette_max >= 0) + png_do_check_palette_indexes(png_ptr, row_info); +#endif + +#ifdef PNG_READ_BGR_SUPPORTED + if ((png_ptr->transformations & PNG_BGR) != 0) + png_do_bgr(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) + png_do_packswap(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_FILLER_SUPPORTED + if ((png_ptr->transformations & PNG_FILLER) != 0) + png_do_read_filler(row_info, png_ptr->row_buf + 1, + (png_uint_32)png_ptr->filler, png_ptr->flags); +#endif + +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0) + png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_16BIT_SUPPORTED +#ifdef PNG_READ_SWAP_SUPPORTED + if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) + png_do_swap(row_info, png_ptr->row_buf + 1); +#endif +#endif + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) + { + if (png_ptr->read_user_transform_fn != NULL) + (*(png_ptr->read_user_transform_fn)) /* User read transform function */ + (png_ptr, /* png_ptr */ + row_info, /* row_info: */ + /* png_uint_32 width; width of row */ + /* size_t rowbytes; number of bytes in row */ + /* png_byte color_type; color type of pixels */ + /* png_byte bit_depth; bit depth of samples */ + /* png_byte channels; number of channels (1-4) */ + /* png_byte pixel_depth; bits per pixel (depth*channels) */ + png_ptr->row_buf + 1); /* start of pixel data for row */ +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED + if (png_ptr->user_transform_depth != 0) + row_info->bit_depth = png_ptr->user_transform_depth; + + if (png_ptr->user_transform_channels != 0) + row_info->channels = png_ptr->user_transform_channels; +#endif + row_info->pixel_depth = (png_byte)(row_info->bit_depth * + row_info->channels); + + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width); + } +#endif +} + +#endif /* READ_TRANSFORMS */ +#endif /* READ */ diff --git a/media/libpng/pngrutil.c b/media/libpng/pngrutil.c new file mode 100644 index 0000000000..79b3656806 --- /dev/null +++ b/media/libpng/pngrutil.c @@ -0,0 +1,4976 @@ + +/* pngrutil.c - utilities to read a PNG file + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file contains routines that are only called from within + * libpng itself during the course of reading an image. + */ + +#include "pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +png_uint_32 PNGAPI +png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf) +{ + png_uint_32 uval = png_get_uint_32(buf); + + if (uval > PNG_UINT_31_MAX) + png_error(png_ptr, "PNG unsigned integer out of range"); + + return (uval); +} + +#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED) +/* The following is a variation on the above for use with the fixed + * point values used for gAMA and cHRM. Instead of png_error it + * issues a warning and returns (-1) - an invalid value because both + * gAMA and cHRM use *unsigned* integers for fixed point values. + */ +#define PNG_FIXED_ERROR (-1) + +static png_fixed_point /* PRIVATE */ +png_get_fixed_point(png_structrp png_ptr, png_const_bytep buf) +{ + png_uint_32 uval = png_get_uint_32(buf); + + if (uval <= PNG_UINT_31_MAX) + return (png_fixed_point)uval; /* known to be in range */ + + /* The caller can turn off the warning by passing NULL. */ + if (png_ptr != NULL) + png_warning(png_ptr, "PNG fixed point integer out of range"); + + return PNG_FIXED_ERROR; +} +#endif + +#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED +/* NOTE: the read macros will obscure these definitions, so that if + * PNG_USE_READ_MACROS is set the library will not use them internally, + * but the APIs will still be available externally. + * + * The parentheses around "PNGAPI function_name" in the following three + * functions are necessary because they allow the macros to co-exist with + * these (unused but exported) functions. + */ + +/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */ +png_uint_32 (PNGAPI +png_get_uint_32)(png_const_bytep buf) +{ + png_uint_32 uval = + ((png_uint_32)(*(buf )) << 24) + + ((png_uint_32)(*(buf + 1)) << 16) + + ((png_uint_32)(*(buf + 2)) << 8) + + ((png_uint_32)(*(buf + 3)) ) ; + + return uval; +} + +/* Grab a signed 32-bit integer from a buffer in big-endian format. The + * data is stored in the PNG file in two's complement format and there + * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore + * the following code does a two's complement to native conversion. + */ +png_int_32 (PNGAPI +png_get_int_32)(png_const_bytep buf) +{ + png_uint_32 uval = png_get_uint_32(buf); + if ((uval & 0x80000000) == 0) /* non-negative */ + return (png_int_32)uval; + + uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */ + if ((uval & 0x80000000) == 0) /* no overflow */ + return -(png_int_32)uval; + /* The following has to be safe; this function only gets called on PNG data + * and if we get here that data is invalid. 0 is the most safe value and + * if not then an attacker would surely just generate a PNG with 0 instead. + */ + return 0; +} + +/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */ +png_uint_16 (PNGAPI +png_get_uint_16)(png_const_bytep buf) +{ + /* ANSI-C requires an int value to accommodate at least 16 bits so this + * works and allows the compiler not to worry about possible narrowing + * on 32-bit systems. (Pre-ANSI systems did not make integers smaller + * than 16 bits either.) + */ + unsigned int val = + ((unsigned int)(*buf) << 8) + + ((unsigned int)(*(buf + 1))); + + return (png_uint_16)val; +} + +#endif /* READ_INT_FUNCTIONS */ + +/* Read and check the PNG file signature */ +void /* PRIVATE */ +png_read_sig(png_structrp png_ptr, png_inforp info_ptr) +{ + size_t num_checked, num_to_check; + + /* Exit if the user application does not expect a signature. */ + if (png_ptr->sig_bytes >= 8) + return; + + num_checked = png_ptr->sig_bytes; + num_to_check = 8 - num_checked; + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE; +#endif + + /* The signature must be serialized in a single I/O call. */ + png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); + png_ptr->sig_bytes = 8; + + if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check) != 0) + { + if (num_checked < 4 && + png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) + png_error(png_ptr, "Not a PNG file"); + else + png_error(png_ptr, "PNG file corrupted by ASCII conversion"); + } + if (num_checked < 3) + png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; +} + +/* Read the chunk header (length + type name). + * Put the type name into png_ptr->chunk_name, and return the length. + */ +png_uint_32 /* PRIVATE */ +png_read_chunk_header(png_structrp png_ptr) +{ + png_byte buf[8]; + png_uint_32 length; + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR; +#endif + + /* Read the length and the chunk name. + * This must be performed in a single I/O call. + */ + png_read_data(png_ptr, buf, 8); + length = png_get_uint_31(png_ptr, buf); + + /* Put the chunk name into png_ptr->chunk_name. */ + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4); + + png_debug2(0, "Reading %lx chunk, length = %lu", + (unsigned long)png_ptr->chunk_name, (unsigned long)length); + + /* Reset the crc and run it over the chunk name. */ + png_reset_crc(png_ptr); + png_calculate_crc(png_ptr, buf + 4, 4); + + /* Check to see if chunk name is valid. */ + png_check_chunk_name(png_ptr, png_ptr->chunk_name); + + /* Check for too-large chunk length */ + png_check_chunk_length(png_ptr, length); + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA; +#endif + + return length; +} + +/* Read data, and (optionally) run it through the CRC. */ +void /* PRIVATE */ +png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length) +{ + if (png_ptr == NULL) + return; + + png_read_data(png_ptr, buf, length); + png_calculate_crc(png_ptr, buf, length); +} + +/* Optionally skip data and then check the CRC. Depending on whether we + * are reading an ancillary or critical chunk, and how the program has set + * things up, we may calculate the CRC on the data and print a message. + * Returns '1' if there was a CRC error, '0' otherwise. + */ +int /* PRIVATE */ +png_crc_finish(png_structrp png_ptr, png_uint_32 skip) +{ + /* The size of the local buffer for inflate is a good guess as to a + * reasonable size to use for buffering reads from the application. + */ + while (skip > 0) + { + png_uint_32 len; + png_byte tmpbuf[PNG_INFLATE_BUF_SIZE]; + + len = (sizeof tmpbuf); + if (len > skip) + len = skip; + skip -= len; + + png_crc_read(png_ptr, tmpbuf, len); + } + + if (png_crc_error(png_ptr) != 0) + { + if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0 ? + (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0 : + (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE) != 0) + { + png_chunk_warning(png_ptr, "CRC error"); + } + + else + png_chunk_error(png_ptr, "CRC error"); + + return (1); + } + + return (0); +} + +/* Compare the CRC stored in the PNG file with that calculated by libpng from + * the data it has read thus far. + */ +int /* PRIVATE */ +png_crc_error(png_structrp png_ptr) +{ + png_byte crc_bytes[4]; + png_uint_32 crc; + int need_crc = 1; + + if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0) + { + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == + (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) + need_crc = 0; + } + + else /* critical */ + { + if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0) + need_crc = 0; + } + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC; +#endif + + /* The chunk CRC must be serialized in a single I/O call. */ + png_read_data(png_ptr, crc_bytes, 4); + + if (need_crc != 0) + { + crc = png_get_uint_32(crc_bytes); + return ((int)(crc != png_ptr->crc)); + } + + else + return (0); +} + +#if defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) ||\ + defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_sCAL_SUPPORTED) ||\ + defined(PNG_READ_sPLT_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) ||\ + defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_SEQUENTIAL_READ_SUPPORTED) +/* Manage the read buffer; this simply reallocates the buffer if it is not small + * enough (or if it is not allocated). The routine returns a pointer to the + * buffer; if an error occurs and 'warn' is set the routine returns NULL, else + * it will call png_error (via png_malloc) on failure. (warn == 2 means + * 'silent'). + */ +static png_bytep +png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn) +{ + png_bytep buffer = png_ptr->read_buffer; + + if (buffer != NULL && new_size > png_ptr->read_buffer_size) + { + png_ptr->read_buffer = NULL; + png_ptr->read_buffer = NULL; + png_ptr->read_buffer_size = 0; + png_free(png_ptr, buffer); + buffer = NULL; + } + + if (buffer == NULL) + { + buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size)); + + if (buffer != NULL) + { + memset(buffer, 0, new_size); /* just in case */ + png_ptr->read_buffer = buffer; + png_ptr->read_buffer_size = new_size; + } + + else if (warn < 2) /* else silent */ + { + if (warn != 0) + png_chunk_warning(png_ptr, "insufficient memory to read chunk"); + + else + png_chunk_error(png_ptr, "insufficient memory to read chunk"); + } + } + + return buffer; +} +#endif /* READ_iCCP|iTXt|pCAL|sCAL|sPLT|tEXt|zTXt|SEQUENTIAL_READ */ + +/* png_inflate_claim: claim the zstream for some nefarious purpose that involves + * decompression. Returns Z_OK on success, else a zlib error code. It checks + * the owner but, in final release builds, just issues a warning if some other + * chunk apparently owns the stream. Prior to release it does a png_error. + */ +static int +png_inflate_claim(png_structrp png_ptr, png_uint_32 owner) +{ + if (png_ptr->zowner != 0) + { + char msg[64]; + + PNG_STRING_FROM_CHUNK(msg, png_ptr->zowner); + /* So the message that results is "<chunk> using zstream"; this is an + * internal error, but is very useful for debugging. i18n requirements + * are minimal. + */ + (void)png_safecat(msg, (sizeof msg), 4, " using zstream"); +#if PNG_RELEASE_BUILD + png_chunk_warning(png_ptr, msg); + png_ptr->zowner = 0; +#else + png_chunk_error(png_ptr, msg); +#endif + } + + /* Implementation note: unlike 'png_deflate_claim' this internal function + * does not take the size of the data as an argument. Some efficiency could + * be gained by using this when it is known *if* the zlib stream itself does + * not record the number; however, this is an illusion: the original writer + * of the PNG may have selected a lower window size, and we really must + * follow that because, for systems with with limited capabilities, we + * would otherwise reject the application's attempts to use a smaller window + * size (zlib doesn't have an interface to say "this or lower"!). + * + * inflateReset2 was added to zlib 1.2.4; before this the window could not be + * reset, therefore it is necessary to always allocate the maximum window + * size with earlier zlibs just in case later compressed chunks need it. + */ + { + int ret; /* zlib return code */ +#if ZLIB_VERNUM >= 0x1240 + int window_bits = 0; + +# if defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_MAXIMUM_INFLATE_WINDOW) + if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) == + PNG_OPTION_ON) + { + window_bits = 15; + png_ptr->zstream_start = 0; /* fixed window size */ + } + + else + { + png_ptr->zstream_start = 1; + } +# endif + +#endif /* ZLIB_VERNUM >= 0x1240 */ + + /* Set this for safety, just in case the previous owner left pointers to + * memory allocations. + */ + png_ptr->zstream.next_in = NULL; + png_ptr->zstream.avail_in = 0; + png_ptr->zstream.next_out = NULL; + png_ptr->zstream.avail_out = 0; + + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) + { +#if ZLIB_VERNUM >= 0x1240 + ret = inflateReset2(&png_ptr->zstream, window_bits); +#else + ret = inflateReset(&png_ptr->zstream); +#endif + } + + else + { +#if ZLIB_VERNUM >= 0x1240 + ret = inflateInit2(&png_ptr->zstream, window_bits); +#else + ret = inflateInit(&png_ptr->zstream); +#endif + + if (ret == Z_OK) + png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED; + } + +#if ZLIB_VERNUM >= 0x1290 && \ + defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_IGNORE_ADLER32) + if (((png_ptr->options >> PNG_IGNORE_ADLER32) & 3) == PNG_OPTION_ON) + /* Turn off validation of the ADLER32 checksum in IDAT chunks */ + ret = inflateValidate(&png_ptr->zstream, 0); +#endif + + if (ret == Z_OK) + png_ptr->zowner = owner; + + else + png_zstream_error(png_ptr, ret); + + return ret; + } + +#ifdef window_bits +# undef window_bits +#endif +} + +#if ZLIB_VERNUM >= 0x1240 +/* Handle the start of the inflate stream if we called inflateInit2(strm,0); + * in this case some zlib versions skip validation of the CINFO field and, in + * certain circumstances, libpng may end up displaying an invalid image, in + * contrast to implementations that call zlib in the normal way (e.g. libpng + * 1.5). + */ +int /* PRIVATE */ +png_zlib_inflate(png_structrp png_ptr, int flush) +{ + if (png_ptr->zstream_start && png_ptr->zstream.avail_in > 0) + { + if ((*png_ptr->zstream.next_in >> 4) > 7) + { + png_ptr->zstream.msg = "invalid window size (libpng)"; + return Z_DATA_ERROR; + } + + png_ptr->zstream_start = 0; + } + + return inflate(&png_ptr->zstream, flush); +} +#endif /* Zlib >= 1.2.4 */ + +#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED +#if defined(PNG_READ_zTXt_SUPPORTED) || defined (PNG_READ_iTXt_SUPPORTED) +/* png_inflate now returns zlib error codes including Z_OK and Z_STREAM_END to + * allow the caller to do multiple calls if required. If the 'finish' flag is + * set Z_FINISH will be passed to the final inflate() call and Z_STREAM_END must + * be returned or there has been a problem, otherwise Z_SYNC_FLUSH is used and + * Z_OK or Z_STREAM_END will be returned on success. + * + * The input and output sizes are updated to the actual amounts of data consumed + * or written, not the amount available (as in a z_stream). The data pointers + * are not changed, so the next input is (data+input_size) and the next + * available output is (output+output_size). + */ +static int +png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish, + /* INPUT: */ png_const_bytep input, png_uint_32p input_size_ptr, + /* OUTPUT: */ png_bytep output, png_alloc_size_t *output_size_ptr) +{ + if (png_ptr->zowner == owner) /* Else not claimed */ + { + int ret; + png_alloc_size_t avail_out = *output_size_ptr; + png_uint_32 avail_in = *input_size_ptr; + + /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it + * can't even necessarily handle 65536 bytes) because the type uInt is + * "16 bits or more". Consequently it is necessary to chunk the input to + * zlib. This code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the + * maximum value that can be stored in a uInt.) It is possible to set + * ZLIB_IO_MAX to a lower value in pngpriv.h and this may sometimes have + * a performance advantage, because it reduces the amount of data accessed + * at each step and that may give the OS more time to page it in. + */ + png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input); + /* avail_in and avail_out are set below from 'size' */ + png_ptr->zstream.avail_in = 0; + png_ptr->zstream.avail_out = 0; + + /* Read directly into the output if it is available (this is set to + * a local buffer below if output is NULL). + */ + if (output != NULL) + png_ptr->zstream.next_out = output; + + do + { + uInt avail; + Byte local_buffer[PNG_INFLATE_BUF_SIZE]; + + /* zlib INPUT BUFFER */ + /* The setting of 'avail_in' used to be outside the loop; by setting it + * inside it is possible to chunk the input to zlib and simply rely on + * zlib to advance the 'next_in' pointer. This allows arbitrary + * amounts of data to be passed through zlib at the unavoidable cost of + * requiring a window save (memcpy of up to 32768 output bytes) + * every ZLIB_IO_MAX input bytes. + */ + avail_in += png_ptr->zstream.avail_in; /* not consumed last time */ + + avail = ZLIB_IO_MAX; + + if (avail_in < avail) + avail = (uInt)avail_in; /* safe: < than ZLIB_IO_MAX */ + + avail_in -= avail; + png_ptr->zstream.avail_in = avail; + + /* zlib OUTPUT BUFFER */ + avail_out += png_ptr->zstream.avail_out; /* not written last time */ + + avail = ZLIB_IO_MAX; /* maximum zlib can process */ + + if (output == NULL) + { + /* Reset the output buffer each time round if output is NULL and + * make available the full buffer, up to 'remaining_space' + */ + png_ptr->zstream.next_out = local_buffer; + if ((sizeof local_buffer) < avail) + avail = (sizeof local_buffer); + } + + if (avail_out < avail) + avail = (uInt)avail_out; /* safe: < ZLIB_IO_MAX */ + + png_ptr->zstream.avail_out = avail; + avail_out -= avail; + + /* zlib inflate call */ + /* In fact 'avail_out' may be 0 at this point, that happens at the end + * of the read when the final LZ end code was not passed at the end of + * the previous chunk of input data. Tell zlib if we have reached the + * end of the output buffer. + */ + ret = PNG_INFLATE(png_ptr, avail_out > 0 ? Z_NO_FLUSH : + (finish ? Z_FINISH : Z_SYNC_FLUSH)); + } while (ret == Z_OK); + + /* For safety kill the local buffer pointer now */ + if (output == NULL) + png_ptr->zstream.next_out = NULL; + + /* Claw back the 'size' and 'remaining_space' byte counts. */ + avail_in += png_ptr->zstream.avail_in; + avail_out += png_ptr->zstream.avail_out; + + /* Update the input and output sizes; the updated values are the amount + * consumed or written, effectively the inverse of what zlib uses. + */ + if (avail_out > 0) + *output_size_ptr -= avail_out; + + if (avail_in > 0) + *input_size_ptr -= avail_in; + + /* Ensure png_ptr->zstream.msg is set (even in the success case!) */ + png_zstream_error(png_ptr, ret); + return ret; + } + + else + { + /* This is a bad internal error. The recovery assigns to the zstream msg + * pointer, which is not owned by the caller, but this is safe; it's only + * used on errors! + */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed"); + return Z_STREAM_ERROR; + } +} + +/* + * Decompress trailing data in a chunk. The assumption is that read_buffer + * points at an allocated area holding the contents of a chunk with a + * trailing compressed part. What we get back is an allocated area + * holding the original prefix part and an uncompressed version of the + * trailing part (the malloc area passed in is freed). + */ +static int +png_decompress_chunk(png_structrp png_ptr, + png_uint_32 chunklength, png_uint_32 prefix_size, + png_alloc_size_t *newlength /* must be initialized to the maximum! */, + int terminate /*add a '\0' to the end of the uncompressed data*/) +{ + /* TODO: implement different limits for different types of chunk. + * + * The caller supplies *newlength set to the maximum length of the + * uncompressed data, but this routine allocates space for the prefix and + * maybe a '\0' terminator too. We have to assume that 'prefix_size' is + * limited only by the maximum chunk size. + */ + png_alloc_size_t limit = PNG_SIZE_MAX; + +# ifdef PNG_SET_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_malloc_max > 0 && + png_ptr->user_chunk_malloc_max < limit) + limit = png_ptr->user_chunk_malloc_max; +# elif PNG_USER_CHUNK_MALLOC_MAX > 0 + if (PNG_USER_CHUNK_MALLOC_MAX < limit) + limit = PNG_USER_CHUNK_MALLOC_MAX; +# endif + + if (limit >= prefix_size + (terminate != 0)) + { + int ret; + + limit -= prefix_size + (terminate != 0); + + if (limit < *newlength) + *newlength = limit; + + /* Now try to claim the stream. */ + ret = png_inflate_claim(png_ptr, png_ptr->chunk_name); + + if (ret == Z_OK) + { + png_uint_32 lzsize = chunklength - prefix_size; + + ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/, + /* input: */ png_ptr->read_buffer + prefix_size, &lzsize, + /* output: */ NULL, newlength); + + if (ret == Z_STREAM_END) + { + /* Use 'inflateReset' here, not 'inflateReset2' because this + * preserves the previously decided window size (otherwise it would + * be necessary to store the previous window size.) In practice + * this doesn't matter anyway, because png_inflate will call inflate + * with Z_FINISH in almost all cases, so the window will not be + * maintained. + */ + if (inflateReset(&png_ptr->zstream) == Z_OK) + { + /* Because of the limit checks above we know that the new, + * expanded, size will fit in a size_t (let alone an + * png_alloc_size_t). Use png_malloc_base here to avoid an + * extra OOM message. + */ + png_alloc_size_t new_size = *newlength; + png_alloc_size_t buffer_size = prefix_size + new_size + + (terminate != 0); + png_bytep text = png_voidcast(png_bytep, png_malloc_base(png_ptr, + buffer_size)); + + if (text != NULL) + { + memset(text, 0, buffer_size); + + ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/, + png_ptr->read_buffer + prefix_size, &lzsize, + text + prefix_size, newlength); + + if (ret == Z_STREAM_END) + { + if (new_size == *newlength) + { + if (terminate != 0) + text[prefix_size + *newlength] = 0; + + if (prefix_size > 0) + memcpy(text, png_ptr->read_buffer, prefix_size); + + { + png_bytep old_ptr = png_ptr->read_buffer; + + png_ptr->read_buffer = text; + png_ptr->read_buffer_size = buffer_size; + text = old_ptr; /* freed below */ + } + } + + else + { + /* The size changed on the second read, there can be no + * guarantee that anything is correct at this point. + * The 'msg' pointer has been set to "unexpected end of + * LZ stream", which is fine, but return an error code + * that the caller won't accept. + */ + ret = PNG_UNEXPECTED_ZLIB_RETURN; + } + } + + else if (ret == Z_OK) + ret = PNG_UNEXPECTED_ZLIB_RETURN; /* for safety */ + + /* Free the text pointer (this is the old read_buffer on + * success) + */ + png_free(png_ptr, text); + + /* This really is very benign, but it's still an error because + * the extra space may otherwise be used as a Trojan Horse. + */ + if (ret == Z_STREAM_END && + chunklength - prefix_size != lzsize) + png_chunk_benign_error(png_ptr, "extra compressed data"); + } + + else + { + /* Out of memory allocating the buffer */ + ret = Z_MEM_ERROR; + png_zstream_error(png_ptr, Z_MEM_ERROR); + } + } + + else + { + /* inflateReset failed, store the error message */ + png_zstream_error(png_ptr, ret); + ret = PNG_UNEXPECTED_ZLIB_RETURN; + } + } + + else if (ret == Z_OK) + ret = PNG_UNEXPECTED_ZLIB_RETURN; + + /* Release the claimed stream */ + png_ptr->zowner = 0; + } + + else /* the claim failed */ if (ret == Z_STREAM_END) /* impossible! */ + ret = PNG_UNEXPECTED_ZLIB_RETURN; + + return ret; + } + + else + { + /* Application/configuration limits exceeded */ + png_zstream_error(png_ptr, Z_MEM_ERROR); + return Z_MEM_ERROR; + } +} +#endif /* READ_zTXt || READ_iTXt */ +#endif /* READ_COMPRESSED_TEXT */ + +#ifdef PNG_READ_iCCP_SUPPORTED +/* Perform a partial read and decompress, producing 'avail_out' bytes and + * reading from the current chunk as required. + */ +static int +png_inflate_read(png_structrp png_ptr, png_bytep read_buffer, uInt read_size, + png_uint_32p chunk_bytes, png_bytep next_out, png_alloc_size_t *out_size, + int finish) +{ + if (png_ptr->zowner == png_ptr->chunk_name) + { + int ret; + + /* next_in and avail_in must have been initialized by the caller. */ + png_ptr->zstream.next_out = next_out; + png_ptr->zstream.avail_out = 0; /* set in the loop */ + + do + { + if (png_ptr->zstream.avail_in == 0) + { + if (read_size > *chunk_bytes) + read_size = (uInt)*chunk_bytes; + *chunk_bytes -= read_size; + + if (read_size > 0) + png_crc_read(png_ptr, read_buffer, read_size); + + png_ptr->zstream.next_in = read_buffer; + png_ptr->zstream.avail_in = read_size; + } + + if (png_ptr->zstream.avail_out == 0) + { + uInt avail = ZLIB_IO_MAX; + if (avail > *out_size) + avail = (uInt)*out_size; + *out_size -= avail; + + png_ptr->zstream.avail_out = avail; + } + + /* Use Z_SYNC_FLUSH when there is no more chunk data to ensure that all + * the available output is produced; this allows reading of truncated + * streams. + */ + ret = PNG_INFLATE(png_ptr, *chunk_bytes > 0 ? + Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH)); + } + while (ret == Z_OK && (*out_size > 0 || png_ptr->zstream.avail_out > 0)); + + *out_size += png_ptr->zstream.avail_out; + png_ptr->zstream.avail_out = 0; /* Should not be required, but is safe */ + + /* Ensure the error message pointer is always set: */ + png_zstream_error(png_ptr, ret); + return ret; + } + + else + { + png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed"); + return Z_STREAM_ERROR; + } +} +#endif /* READ_iCCP */ + +/* Read and check the IDHR chunk */ + +void /* PRIVATE */ +png_handle_IHDR(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte buf[13]; + png_uint_32 width, height; + int bit_depth, color_type, compression_type, filter_type; + int interlace_type; + + png_debug(1, "in png_handle_IHDR"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) != 0) + png_chunk_error(png_ptr, "out of place"); + + /* Check the length */ + if (length != 13) + png_chunk_error(png_ptr, "invalid"); + + png_ptr->mode |= PNG_HAVE_IHDR; + + png_crc_read(png_ptr, buf, 13); + png_crc_finish(png_ptr, 0); + + width = png_get_uint_31(png_ptr, buf); + height = png_get_uint_31(png_ptr, buf + 4); + bit_depth = buf[8]; + color_type = buf[9]; + compression_type = buf[10]; + filter_type = buf[11]; + interlace_type = buf[12]; + +#ifdef PNG_READ_APNG_SUPPORTED + png_ptr->first_frame_width = width; + png_ptr->first_frame_height = height; +#endif + + /* Set internal variables */ + png_ptr->width = width; + png_ptr->height = height; + png_ptr->bit_depth = (png_byte)bit_depth; + png_ptr->interlaced = (png_byte)interlace_type; + png_ptr->color_type = (png_byte)color_type; +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_ptr->filter_type = (png_byte)filter_type; +#endif + png_ptr->compression_type = (png_byte)compression_type; + + /* Find number of channels */ + switch (png_ptr->color_type) + { + default: /* invalid, png_set_IHDR calls png_error */ + case PNG_COLOR_TYPE_GRAY: + case PNG_COLOR_TYPE_PALETTE: + png_ptr->channels = 1; + break; + + case PNG_COLOR_TYPE_RGB: + png_ptr->channels = 3; + break; + + case PNG_COLOR_TYPE_GRAY_ALPHA: + png_ptr->channels = 2; + break; + + case PNG_COLOR_TYPE_RGB_ALPHA: + png_ptr->channels = 4; + break; + } + + /* Set up other useful info */ + png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * png_ptr->channels); + png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width); + png_debug1(3, "bit_depth = %d", png_ptr->bit_depth); + png_debug1(3, "channels = %d", png_ptr->channels); + png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes); + png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, + color_type, interlace_type, compression_type, filter_type); +} + +/* Read and check the palette */ +void /* PRIVATE */ +png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_color palette[PNG_MAX_PALETTE_LENGTH]; + int max_palette_length, num, i; +#ifdef PNG_POINTER_INDEXING_SUPPORTED + png_colorp pal_ptr; +#endif + + png_debug(1, "in png_handle_PLTE"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + /* Moved to before the 'after IDAT' check below because otherwise duplicate + * PLTE chunks are potentially ignored (the spec says there shall not be more + * than one PLTE, the error is not treated as benign, so this check trumps + * the requirement that PLTE appears before IDAT.) + */ + else if ((png_ptr->mode & PNG_HAVE_PLTE) != 0) + png_chunk_error(png_ptr, "duplicate"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + /* This is benign because the non-benign error happened before, when an + * IDAT was encountered in a color-mapped image with no PLTE. + */ + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + png_ptr->mode |= PNG_HAVE_PLTE; + + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "ignored in grayscale PNG"); + return; + } + +#ifndef PNG_READ_OPT_PLTE_SUPPORTED + if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + { + png_crc_finish(png_ptr, length); + return; + } +#endif + + if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3) + { + png_crc_finish(png_ptr, length); + + if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + png_chunk_benign_error(png_ptr, "invalid"); + + else + png_chunk_error(png_ptr, "invalid"); + + return; + } + + /* The cast is safe because 'length' is less than 3*PNG_MAX_PALETTE_LENGTH */ + num = (int)length / 3; + + /* If the palette has 256 or fewer entries but is too large for the bit + * depth, we don't issue an error, to preserve the behavior of previous + * libpng versions. We silently truncate the unused extra palette entries + * here. + */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + max_palette_length = (1 << png_ptr->bit_depth); + else + max_palette_length = PNG_MAX_PALETTE_LENGTH; + + if (num > max_palette_length) + num = max_palette_length; + +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++) + { + png_byte buf[3]; + + png_crc_read(png_ptr, buf, 3); + pal_ptr->red = buf[0]; + pal_ptr->green = buf[1]; + pal_ptr->blue = buf[2]; + } +#else + for (i = 0; i < num; i++) + { + png_byte buf[3]; + + png_crc_read(png_ptr, buf, 3); + /* Don't depend upon png_color being any order */ + palette[i].red = buf[0]; + palette[i].green = buf[1]; + palette[i].blue = buf[2]; + } +#endif + + /* If we actually need the PLTE chunk (ie for a paletted image), we do + * whatever the normal CRC configuration tells us. However, if we + * have an RGB image, the PLTE can be considered ancillary, so + * we will act as though it is. + */ +#ifndef PNG_READ_OPT_PLTE_SUPPORTED + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) +#endif + { + png_crc_finish(png_ptr, (png_uint_32) (length - (unsigned int)num * 3)); + } + +#ifndef PNG_READ_OPT_PLTE_SUPPORTED + else if (png_crc_error(png_ptr) != 0) /* Only if we have a CRC error */ + { + /* If we don't want to use the data from an ancillary chunk, + * we have two options: an error abort, or a warning and we + * ignore the data in this chunk (which should be OK, since + * it's considered ancillary for a RGB or RGBA image). + * + * IMPLEMENTATION NOTE: this is only here because png_crc_finish uses the + * chunk type to determine whether to check the ancillary or the critical + * flags. + */ + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE) == 0) + { + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) != 0) + return; + + else + png_chunk_error(png_ptr, "CRC error"); + } + + /* Otherwise, we (optionally) emit a warning and use the chunk. */ + else if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0) + png_chunk_warning(png_ptr, "CRC error"); + } +#endif + + /* TODO: png_set_PLTE has the side effect of setting png_ptr->palette to its + * own copy of the palette. This has the side effect that when png_start_row + * is called (this happens after any call to png_read_update_info) the + * info_ptr palette gets changed. This is extremely unexpected and + * confusing. + * + * Fix this by not sharing the palette in this way. + */ + png_set_PLTE(png_ptr, info_ptr, palette, num); + + /* The three chunks, bKGD, hIST and tRNS *must* appear after PLTE and before + * IDAT. Prior to 1.6.0 this was not checked; instead the code merely + * checked the apparent validity of a tRNS chunk inserted before PLTE on a + * palette PNG. 1.6.0 attempts to rigorously follow the standard and + * therefore does a benign error if the erroneous condition is detected *and* + * cancels the tRNS if the benign error returns. The alternative is to + * amend the standard since it would be rather hypocritical of the standards + * maintainers to ignore it. + */ +#ifdef PNG_READ_tRNS_SUPPORTED + if (png_ptr->num_trans > 0 || + (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0)) + { + /* Cancel this because otherwise it would be used if the transforms + * require it. Don't cancel the 'valid' flag because this would prevent + * detection of duplicate chunks. + */ + png_ptr->num_trans = 0; + + if (info_ptr != NULL) + info_ptr->num_trans = 0; + + png_chunk_benign_error(png_ptr, "tRNS must be after"); + } +#endif + +#ifdef PNG_READ_hIST_SUPPORTED + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0) + png_chunk_benign_error(png_ptr, "hIST must be after"); +#endif + +#ifdef PNG_READ_bKGD_SUPPORTED + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0) + png_chunk_benign_error(png_ptr, "bKGD must be after"); +#endif +} + +void /* PRIVATE */ +png_handle_IEND(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_debug(1, "in png_handle_IEND"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0 || + (png_ptr->mode & PNG_HAVE_IDAT) == 0) + png_chunk_error(png_ptr, "out of place"); + + png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND); + + png_crc_finish(png_ptr, length); + + if (length != 0) + png_chunk_benign_error(png_ptr, "invalid"); + + PNG_UNUSED(info_ptr) +} + +#ifdef PNG_READ_gAMA_SUPPORTED +void /* PRIVATE */ +png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_fixed_point igamma; + png_byte buf[4]; + + png_debug(1, "in png_handle_gAMA"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + if (length != 4) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, 4); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + igamma = png_get_fixed_point(NULL, buf); + + png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma); + png_colorspace_sync(png_ptr, info_ptr); +} +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED +void /* PRIVATE */ +png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + unsigned int truelen, i; + png_byte sample_depth; + png_byte buf[4]; + + png_debug(1, "in png_handle_sBIT"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + truelen = 3; + sample_depth = 8; + } + + else + { + truelen = png_ptr->channels; + sample_depth = png_ptr->bit_depth; + } + + if (length != truelen || length > 4) + { + png_chunk_benign_error(png_ptr, "invalid"); + png_crc_finish(png_ptr, length); + return; + } + + buf[0] = buf[1] = buf[2] = buf[3] = sample_depth; + png_crc_read(png_ptr, buf, truelen); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + for (i=0; i<truelen; ++i) + { + if (buf[i] == 0 || buf[i] > sample_depth) + { + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + } + + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + png_ptr->sig_bit.red = buf[0]; + png_ptr->sig_bit.green = buf[1]; + png_ptr->sig_bit.blue = buf[2]; + png_ptr->sig_bit.alpha = buf[3]; + } + + else + { + png_ptr->sig_bit.gray = buf[0]; + png_ptr->sig_bit.red = buf[0]; + png_ptr->sig_bit.green = buf[0]; + png_ptr->sig_bit.blue = buf[0]; + png_ptr->sig_bit.alpha = buf[1]; + } + + png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit)); +} +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED +void /* PRIVATE */ +png_handle_cHRM(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte buf[32]; + png_xy xy; + + png_debug(1, "in png_handle_cHRM"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + if (length != 32) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, 32); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + xy.whitex = png_get_fixed_point(NULL, buf); + xy.whitey = png_get_fixed_point(NULL, buf + 4); + xy.redx = png_get_fixed_point(NULL, buf + 8); + xy.redy = png_get_fixed_point(NULL, buf + 12); + xy.greenx = png_get_fixed_point(NULL, buf + 16); + xy.greeny = png_get_fixed_point(NULL, buf + 20); + xy.bluex = png_get_fixed_point(NULL, buf + 24); + xy.bluey = png_get_fixed_point(NULL, buf + 28); + + if (xy.whitex == PNG_FIXED_ERROR || + xy.whitey == PNG_FIXED_ERROR || + xy.redx == PNG_FIXED_ERROR || + xy.redy == PNG_FIXED_ERROR || + xy.greenx == PNG_FIXED_ERROR || + xy.greeny == PNG_FIXED_ERROR || + xy.bluex == PNG_FIXED_ERROR || + xy.bluey == PNG_FIXED_ERROR) + { + png_chunk_benign_error(png_ptr, "invalid values"); + return; + } + + /* If a colorspace error has already been output skip this chunk */ + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) + return; + + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0) + { + png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID; + png_colorspace_sync(png_ptr, info_ptr); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + png_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM; + (void)png_colorspace_set_chromaticities(png_ptr, &png_ptr->colorspace, &xy, + 1/*prefer cHRM values*/); + png_colorspace_sync(png_ptr, info_ptr); +} +#endif + +#ifdef PNG_READ_sRGB_SUPPORTED +void /* PRIVATE */ +png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte intent; + + png_debug(1, "in png_handle_sRGB"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + if (length != 1) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, &intent, 1); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + /* If a colorspace error has already been output skip this chunk */ + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) + return; + + /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect + * this. + */ + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) != 0) + { + png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID; + png_colorspace_sync(png_ptr, info_ptr); + png_chunk_benign_error(png_ptr, "too many profiles"); + return; + } + + (void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent); + png_colorspace_sync(png_ptr, info_ptr); +} +#endif /* READ_sRGB */ + +#ifdef PNG_READ_iCCP_SUPPORTED +void /* PRIVATE */ +png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +/* Note: this does not properly handle profiles that are > 64K under DOS */ +{ + png_const_charp errmsg = NULL; /* error message output, or no error */ + int finished = 0; /* crc checked */ + + png_debug(1, "in png_handle_iCCP"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + /* Consistent with all the above colorspace handling an obviously *invalid* + * chunk is just ignored, so does not invalidate the color space. An + * alternative is to set the 'invalid' flags at the start of this routine + * and only clear them in they were not set before and all the tests pass. + */ + + /* The keyword must be at least one character and there is a + * terminator (0) byte and the compression method byte, and the + * 'zlib' datastream is at least 11 bytes. + */ + if (length < 14) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "too short"); + return; + } + + /* If a colorspace error has already been output skip this chunk */ + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) + { + png_crc_finish(png_ptr, length); + return; + } + + /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect + * this. + */ + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) == 0) + { + uInt read_length, keyword_length; + char keyword[81]; + + /* Find the keyword; the keyword plus separator and compression method + * bytes can be at most 81 characters long. + */ + read_length = 81; /* maximum */ + if (read_length > length) + read_length = (uInt)length; + + png_crc_read(png_ptr, (png_bytep)keyword, read_length); + length -= read_length; + + /* The minimum 'zlib' stream is assumed to be just the 2 byte header, + * 5 bytes minimum 'deflate' stream, and the 4 byte checksum. + */ + if (length < 11) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "too short"); + return; + } + + keyword_length = 0; + while (keyword_length < 80 && keyword_length < read_length && + keyword[keyword_length] != 0) + ++keyword_length; + + /* TODO: make the keyword checking common */ + if (keyword_length >= 1 && keyword_length <= 79) + { + /* We only understand '0' compression - deflate - so if we get a + * different value we can't safely decode the chunk. + */ + if (keyword_length+1 < read_length && + keyword[keyword_length+1] == PNG_COMPRESSION_TYPE_BASE) + { + read_length -= keyword_length+2; + + if (png_inflate_claim(png_ptr, png_iCCP) == Z_OK) + { + Byte profile_header[132]={0}; + Byte local_buffer[PNG_INFLATE_BUF_SIZE]; + png_alloc_size_t size = (sizeof profile_header); + + png_ptr->zstream.next_in = (Bytef*)keyword + (keyword_length+2); + png_ptr->zstream.avail_in = read_length; + (void)png_inflate_read(png_ptr, local_buffer, + (sizeof local_buffer), &length, profile_header, &size, + 0/*finish: don't, because the output is too small*/); + + if (size == 0) + { + /* We have the ICC profile header; do the basic header checks. + */ + png_uint_32 profile_length = png_get_uint_32(profile_header); + + if (png_icc_check_length(png_ptr, &png_ptr->colorspace, + keyword, profile_length) != 0) + { + /* The length is apparently ok, so we can check the 132 + * byte header. + */ + if (png_icc_check_header(png_ptr, &png_ptr->colorspace, + keyword, profile_length, profile_header, + png_ptr->color_type) != 0) + { + /* Now read the tag table; a variable size buffer is + * needed at this point, allocate one for the whole + * profile. The header check has already validated + * that none of this stuff will overflow. + */ + png_uint_32 tag_count = + png_get_uint_32(profile_header + 128); + png_bytep profile = png_read_buffer(png_ptr, + profile_length, 2/*silent*/); + + if (profile != NULL) + { + memcpy(profile, profile_header, + (sizeof profile_header)); + + size = 12 * tag_count; + + (void)png_inflate_read(png_ptr, local_buffer, + (sizeof local_buffer), &length, + profile + (sizeof profile_header), &size, 0); + + /* Still expect a buffer error because we expect + * there to be some tag data! + */ + if (size == 0) + { + if (png_icc_check_tag_table(png_ptr, + &png_ptr->colorspace, keyword, profile_length, + profile) != 0) + { + /* The profile has been validated for basic + * security issues, so read the whole thing in. + */ + size = profile_length - (sizeof profile_header) + - 12 * tag_count; + + (void)png_inflate_read(png_ptr, local_buffer, + (sizeof local_buffer), &length, + profile + (sizeof profile_header) + + 12 * tag_count, &size, 1/*finish*/); + + if (length > 0 && !(png_ptr->flags & + PNG_FLAG_BENIGN_ERRORS_WARN)) + errmsg = "extra compressed data"; + + /* But otherwise allow extra data: */ + else if (size == 0) + { + if (length > 0) + { + /* This can be handled completely, so + * keep going. + */ + png_chunk_warning(png_ptr, + "extra compressed data"); + } + + png_crc_finish(png_ptr, length); + finished = 1; + +# if defined(PNG_sRGB_SUPPORTED) && PNG_sRGB_PROFILE_CHECKS >= 0 + /* Check for a match against sRGB */ + png_icc_set_sRGB(png_ptr, + &png_ptr->colorspace, profile, + png_ptr->zstream.adler); +# endif + + /* Steal the profile for info_ptr. */ + if (info_ptr != NULL) + { + png_free_data(png_ptr, info_ptr, + PNG_FREE_ICCP, 0); + + info_ptr->iccp_name = png_voidcast(char*, + png_malloc_base(png_ptr, + keyword_length+1)); + if (info_ptr->iccp_name != NULL) + { + memcpy(info_ptr->iccp_name, keyword, + keyword_length+1); + info_ptr->iccp_proflen = + profile_length; + info_ptr->iccp_profile = profile; + png_ptr->read_buffer = NULL; /*steal*/ + info_ptr->free_me |= PNG_FREE_ICCP; + info_ptr->valid |= PNG_INFO_iCCP; + } + + else + { + png_ptr->colorspace.flags |= + PNG_COLORSPACE_INVALID; + errmsg = "out of memory"; + } + } + + /* else the profile remains in the read + * buffer which gets reused for subsequent + * chunks. + */ + + if (info_ptr != NULL) + png_colorspace_sync(png_ptr, info_ptr); + + if (errmsg == NULL) + { + png_ptr->zowner = 0; + return; + } + } + if (errmsg == NULL) + errmsg = png_ptr->zstream.msg; + } + /* else png_icc_check_tag_table output an error */ + } + else /* profile truncated */ + errmsg = png_ptr->zstream.msg; + } + + else + errmsg = "out of memory"; + } + + /* else png_icc_check_header output an error */ + } + + /* else png_icc_check_length output an error */ + } + + else /* profile truncated */ + errmsg = png_ptr->zstream.msg; + + /* Release the stream */ + png_ptr->zowner = 0; + } + + else /* png_inflate_claim failed */ + errmsg = png_ptr->zstream.msg; + } + + else + errmsg = "bad compression method"; /* or missing */ + } + + else + errmsg = "bad keyword"; + } + + else + errmsg = "too many profiles"; + + /* Failure: the reason is in 'errmsg' */ + if (finished == 0) + png_crc_finish(png_ptr, length); + + png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID; + png_colorspace_sync(png_ptr, info_ptr); + if (errmsg != NULL) /* else already output */ + png_chunk_benign_error(png_ptr, errmsg); +} +#endif /* READ_iCCP */ + +#ifdef PNG_READ_sPLT_SUPPORTED +void /* PRIVATE */ +png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +/* Note: this does not properly handle chunks that are > 64K under DOS */ +{ + png_bytep entry_start, buffer; + png_sPLT_t new_palette; + png_sPLT_entryp pp; + png_uint_32 data_length; + int entry_size, i; + png_uint_32 skip = 0; + png_uint_32 dl; + size_t max_dl; + + png_debug(1, "in png_handle_sPLT"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_warning(png_ptr, "No space in chunk cache for sPLT"); + png_crc_finish(png_ptr, length); + return; + } + } +#endif + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + +#ifdef PNG_MAX_MALLOC_64K + if (length > 65535U) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "too large to fit in memory"); + return; + } +#endif + + buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/); + if (buffer == NULL) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + + /* WARNING: this may break if size_t is less than 32 bits; it is assumed + * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a + * potential breakage point if the types in pngconf.h aren't exactly right. + */ + png_crc_read(png_ptr, buffer, length); + + if (png_crc_finish(png_ptr, skip) != 0) + return; + + buffer[length] = 0; + + for (entry_start = buffer; *entry_start; entry_start++) + /* Empty loop to find end of name */ ; + + ++entry_start; + + /* A sample depth should follow the separator, and we should be on it */ + if (length < 2U || entry_start > buffer + (length - 2U)) + { + png_warning(png_ptr, "malformed sPLT chunk"); + return; + } + + new_palette.depth = *entry_start++; + entry_size = (new_palette.depth == 8 ? 6 : 10); + /* This must fit in a png_uint_32 because it is derived from the original + * chunk data length. + */ + data_length = length - (png_uint_32)(entry_start - buffer); + + /* Integrity-check the data length */ + if ((data_length % (unsigned int)entry_size) != 0) + { + png_warning(png_ptr, "sPLT chunk has bad length"); + return; + } + + dl = (png_uint_32)(data_length / (unsigned int)entry_size); + max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry)); + + if (dl > max_dl) + { + png_warning(png_ptr, "sPLT chunk too long"); + return; + } + + new_palette.nentries = (png_int_32)(data_length / (unsigned int)entry_size); + + new_palette.entries = (png_sPLT_entryp)png_malloc_warn(png_ptr, + (png_alloc_size_t) new_palette.nentries * (sizeof (png_sPLT_entry))); + + if (new_palette.entries == NULL) + { + png_warning(png_ptr, "sPLT chunk requires too much memory"); + return; + } + +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (i = 0; i < new_palette.nentries; i++) + { + pp = new_palette.entries + i; + + if (new_palette.depth == 8) + { + pp->red = *entry_start++; + pp->green = *entry_start++; + pp->blue = *entry_start++; + pp->alpha = *entry_start++; + } + + else + { + pp->red = png_get_uint_16(entry_start); entry_start += 2; + pp->green = png_get_uint_16(entry_start); entry_start += 2; + pp->blue = png_get_uint_16(entry_start); entry_start += 2; + pp->alpha = png_get_uint_16(entry_start); entry_start += 2; + } + + pp->frequency = png_get_uint_16(entry_start); entry_start += 2; + } +#else + pp = new_palette.entries; + + for (i = 0; i < new_palette.nentries; i++) + { + + if (new_palette.depth == 8) + { + pp[i].red = *entry_start++; + pp[i].green = *entry_start++; + pp[i].blue = *entry_start++; + pp[i].alpha = *entry_start++; + } + + else + { + pp[i].red = png_get_uint_16(entry_start); entry_start += 2; + pp[i].green = png_get_uint_16(entry_start); entry_start += 2; + pp[i].blue = png_get_uint_16(entry_start); entry_start += 2; + pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2; + } + + pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2; + } +#endif + + /* Discard all chunk data except the name and stash that */ + new_palette.name = (png_charp)buffer; + + png_set_sPLT(png_ptr, info_ptr, &new_palette, 1); + + png_free(png_ptr, new_palette.entries); +} +#endif /* READ_sPLT */ + +#ifdef PNG_READ_tRNS_SUPPORTED +void /* PRIVATE */ +png_handle_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte readbuf[PNG_MAX_PALETTE_LENGTH]; + + png_debug(1, "in png_handle_tRNS"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + png_byte buf[2]; + + if (length != 2) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, 2); + png_ptr->num_trans = 1; + png_ptr->trans_color.gray = png_get_uint_16(buf); + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + png_byte buf[6]; + + if (length != 6) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, length); + png_ptr->num_trans = 1; + png_ptr->trans_color.red = png_get_uint_16(buf); + png_ptr->trans_color.green = png_get_uint_16(buf + 2); + png_ptr->trans_color.blue = png_get_uint_16(buf + 4); + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if ((png_ptr->mode & PNG_HAVE_PLTE) == 0) + { + /* TODO: is this actually an error in the ISO spec? */ + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + if (length > (unsigned int) png_ptr->num_palette || + length > (unsigned int) PNG_MAX_PALETTE_LENGTH || + length == 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, readbuf, length); + png_ptr->num_trans = (png_uint_16)length; + } + + else + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid with alpha channel"); + return; + } + + if (png_crc_finish(png_ptr, 0) != 0) + { + png_ptr->num_trans = 0; + return; + } + + /* TODO: this is a horrible side effect in the palette case because the + * png_struct ends up with a pointer to the tRNS buffer owned by the + * png_info. Fix this. + */ + png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans, + &(png_ptr->trans_color)); +} +#endif + +#ifdef PNG_READ_bKGD_SUPPORTED +void /* PRIVATE */ +png_handle_bKGD(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + unsigned int truelen; + png_byte buf[6]; + png_color_16 background; + + png_debug(1, "in png_handle_bKGD"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 || + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + (png_ptr->mode & PNG_HAVE_PLTE) == 0)) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + truelen = 1; + + else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + truelen = 6; + + else + truelen = 2; + + if (length != truelen) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, truelen); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + /* We convert the index value into RGB components so that we can allow + * arbitrary RGB values for background when we have transparency, and + * so it is easy to determine the RGB values of the background color + * from the info_ptr struct. + */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + background.index = buf[0]; + + if (info_ptr != NULL && info_ptr->num_palette != 0) + { + if (buf[0] >= info_ptr->num_palette) + { + png_chunk_benign_error(png_ptr, "invalid index"); + return; + } + + background.red = (png_uint_16)png_ptr->palette[buf[0]].red; + background.green = (png_uint_16)png_ptr->palette[buf[0]].green; + background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue; + } + + else + background.red = background.green = background.blue = 0; + + background.gray = 0; + } + + else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) /* GRAY */ + { + if (png_ptr->bit_depth <= 8) + { + if (buf[0] != 0 || buf[1] >= (unsigned int)(1 << png_ptr->bit_depth)) + { + png_chunk_benign_error(png_ptr, "invalid gray level"); + return; + } + } + + background.index = 0; + background.red = + background.green = + background.blue = + background.gray = png_get_uint_16(buf); + } + + else + { + if (png_ptr->bit_depth <= 8) + { + if (buf[0] != 0 || buf[2] != 0 || buf[4] != 0) + { + png_chunk_benign_error(png_ptr, "invalid color"); + return; + } + } + + background.index = 0; + background.red = png_get_uint_16(buf); + background.green = png_get_uint_16(buf + 2); + background.blue = png_get_uint_16(buf + 4); + background.gray = 0; + } + + png_set_bKGD(png_ptr, info_ptr, &background); +} +#endif + +#ifdef PNG_READ_eXIf_SUPPORTED +void /* PRIVATE */ +png_handle_eXIf(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + unsigned int i; + + png_debug(1, "in png_handle_eXIf"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + if (length < 2) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "too short"); + return; + } + + else if (info_ptr == NULL || (info_ptr->valid & PNG_INFO_eXIf) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + info_ptr->free_me |= PNG_FREE_EXIF; + + info_ptr->eXIf_buf = png_voidcast(png_bytep, + png_malloc_warn(png_ptr, length)); + + if (info_ptr->eXIf_buf == NULL) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + for (i = 0; i < length; i++) + { + png_byte buf[1]; + png_crc_read(png_ptr, buf, 1); + info_ptr->eXIf_buf[i] = buf[0]; + if (i == 1 && buf[0] != 'M' && buf[0] != 'I' + && info_ptr->eXIf_buf[0] != buf[0]) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "incorrect byte-order specifier"); + png_free(png_ptr, info_ptr->eXIf_buf); + info_ptr->eXIf_buf = NULL; + return; + } + } + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + png_set_eXIf_1(png_ptr, info_ptr, length, info_ptr->eXIf_buf); + + png_free(png_ptr, info_ptr->eXIf_buf); + info_ptr->eXIf_buf = NULL; +} +#endif + +#ifdef PNG_READ_hIST_SUPPORTED +void /* PRIVATE */ +png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + unsigned int num, i; + png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH]; + + png_debug(1, "in png_handle_hIST"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 || + (png_ptr->mode & PNG_HAVE_PLTE) == 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + num = length / 2 ; + + if (num != (unsigned int) png_ptr->num_palette || + num > (unsigned int) PNG_MAX_PALETTE_LENGTH) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + for (i = 0; i < num; i++) + { + png_byte buf[2]; + + png_crc_read(png_ptr, buf, 2); + readbuf[i] = png_get_uint_16(buf); + } + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + png_set_hIST(png_ptr, info_ptr, readbuf); +} +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED +void /* PRIVATE */ +png_handle_pHYs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte buf[9]; + png_uint_32 res_x, res_y; + int unit_type; + + png_debug(1, "in png_handle_pHYs"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + if (length != 9) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, 9); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + res_x = png_get_uint_32(buf); + res_y = png_get_uint_32(buf + 4); + unit_type = buf[8]; + png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type); +} +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED +void /* PRIVATE */ +png_handle_oFFs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte buf[9]; + png_int_32 offset_x, offset_y; + int unit_type; + + png_debug(1, "in png_handle_oFFs"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + if (length != 9) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, 9); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + offset_x = png_get_int_32(buf); + offset_y = png_get_int_32(buf + 4); + unit_type = buf[8]; + png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type); +} +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED +/* Read the pCAL chunk (described in the PNG Extensions document) */ +void /* PRIVATE */ +png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_int_32 X0, X1; + png_byte type, nparams; + png_bytep buffer, buf, units, endptr; + png_charpp params; + int i; + + png_debug(1, "in png_handle_pCAL"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)", + length + 1); + + buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/); + + if (buffer == NULL) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + png_crc_read(png_ptr, buffer, length); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + buffer[length] = 0; /* Null terminate the last string */ + + png_debug(3, "Finding end of pCAL purpose string"); + for (buf = buffer; *buf; buf++) + /* Empty loop */ ; + + endptr = buffer + length; + + /* We need to have at least 12 bytes after the purpose string + * in order to get the parameter information. + */ + if (endptr - buf <= 12) + { + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_debug(3, "Reading pCAL X0, X1, type, nparams, and units"); + X0 = png_get_int_32((png_bytep)buf+1); + X1 = png_get_int_32((png_bytep)buf+5); + type = buf[9]; + nparams = buf[10]; + units = buf + 11; + + png_debug(3, "Checking pCAL equation type and number of parameters"); + /* Check that we have the right number of parameters for known + * equation types. + */ + if ((type == PNG_EQUATION_LINEAR && nparams != 2) || + (type == PNG_EQUATION_BASE_E && nparams != 3) || + (type == PNG_EQUATION_ARBITRARY && nparams != 3) || + (type == PNG_EQUATION_HYPERBOLIC && nparams != 4)) + { + png_chunk_benign_error(png_ptr, "invalid parameter count"); + return; + } + + else if (type >= PNG_EQUATION_LAST) + { + png_chunk_benign_error(png_ptr, "unrecognized equation type"); + } + + for (buf = units; *buf; buf++) + /* Empty loop to move past the units string. */ ; + + png_debug(3, "Allocating pCAL parameters array"); + + params = png_voidcast(png_charpp, png_malloc_warn(png_ptr, + nparams * (sizeof (png_charp)))); + + if (params == NULL) + { + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + /* Get pointers to the start of each parameter string. */ + for (i = 0; i < nparams; i++) + { + buf++; /* Skip the null string terminator from previous parameter. */ + + png_debug1(3, "Reading pCAL parameter %d", i); + + for (params[i] = (png_charp)buf; buf <= endptr && *buf != 0; buf++) + /* Empty loop to move past each parameter string */ ; + + /* Make sure we haven't run out of data yet */ + if (buf > endptr) + { + png_free(png_ptr, params); + png_chunk_benign_error(png_ptr, "invalid data"); + return; + } + } + + png_set_pCAL(png_ptr, info_ptr, (png_charp)buffer, X0, X1, type, nparams, + (png_charp)units, params); + + png_free(png_ptr, params); +} +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED +/* Read the sCAL chunk */ +void /* PRIVATE */ +png_handle_sCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_bytep buffer; + size_t i; + int state; + + png_debug(1, "in png_handle_sCAL"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + /* Need unit type, width, \0, height: minimum 4 bytes */ + else if (length < 4) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)", + length + 1); + + buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/); + + if (buffer == NULL) + { + png_chunk_benign_error(png_ptr, "out of memory"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buffer, length); + buffer[length] = 0; /* Null terminate the last string */ + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + /* Validate the unit. */ + if (buffer[0] != 1 && buffer[0] != 2) + { + png_chunk_benign_error(png_ptr, "invalid unit"); + return; + } + + /* Validate the ASCII numbers, need two ASCII numbers separated by + * a '\0' and they need to fit exactly in the chunk data. + */ + i = 1; + state = 0; + + if (png_check_fp_number((png_const_charp)buffer, length, &state, &i) == 0 || + i >= length || buffer[i++] != 0) + png_chunk_benign_error(png_ptr, "bad width format"); + + else if (PNG_FP_IS_POSITIVE(state) == 0) + png_chunk_benign_error(png_ptr, "non-positive width"); + + else + { + size_t heighti = i; + + state = 0; + if (png_check_fp_number((png_const_charp)buffer, length, + &state, &i) == 0 || i != length) + png_chunk_benign_error(png_ptr, "bad height format"); + + else if (PNG_FP_IS_POSITIVE(state) == 0) + png_chunk_benign_error(png_ptr, "non-positive height"); + + else + /* This is the (only) success case. */ + png_set_sCAL_s(png_ptr, info_ptr, buffer[0], + (png_charp)buffer+1, (png_charp)buffer+heighti); + } +} +#endif + +#ifdef PNG_READ_tIME_SUPPORTED +void /* PRIVATE */ +png_handle_tIME(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte buf[7]; + png_time mod_time; + + png_debug(1, "in png_handle_tIME"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + png_ptr->mode |= PNG_AFTER_IDAT; + + if (length != 7) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, 7); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + mod_time.second = buf[6]; + mod_time.minute = buf[5]; + mod_time.hour = buf[4]; + mod_time.day = buf[3]; + mod_time.month = buf[2]; + mod_time.year = png_get_uint_16(buf); + + png_set_tIME(png_ptr, info_ptr, &mod_time); +} +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED +/* Note: this does not properly handle chunks that are > 64K under DOS */ +void /* PRIVATE */ +png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_text text_info; + png_bytep buffer; + png_charp key; + png_charp text; + png_uint_32 skip = 0; + + png_debug(1, "in png_handle_tEXt"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "no space in chunk cache"); + return; + } + } +#endif + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + png_ptr->mode |= PNG_AFTER_IDAT; + +#ifdef PNG_MAX_MALLOC_64K + if (length > 65535U) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "too large to fit in memory"); + return; + } +#endif + + buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/); + + if (buffer == NULL) + { + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + png_crc_read(png_ptr, buffer, length); + + if (png_crc_finish(png_ptr, skip) != 0) + return; + + key = (png_charp)buffer; + key[length] = 0; + + for (text = key; *text; text++) + /* Empty loop to find end of key */ ; + + if (text != key + length) + text++; + + text_info.compression = PNG_TEXT_COMPRESSION_NONE; + text_info.key = key; + text_info.lang = NULL; + text_info.lang_key = NULL; + text_info.itxt_length = 0; + text_info.text = text; + text_info.text_length = strlen(text); + + if (png_set_text_2(png_ptr, info_ptr, &text_info, 1) != 0) + png_warning(png_ptr, "Insufficient memory to process text chunk"); +} +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED +/* Note: this does not correctly handle chunks that are > 64K under DOS */ +void /* PRIVATE */ +png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_const_charp errmsg = NULL; + png_bytep buffer; + png_uint_32 keyword_length; + + png_debug(1, "in png_handle_zTXt"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "no space in chunk cache"); + return; + } + } +#endif + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + png_ptr->mode |= PNG_AFTER_IDAT; + + /* Note, "length" is sufficient here; we won't be adding + * a null terminator later. + */ + buffer = png_read_buffer(png_ptr, length, 2/*silent*/); + + if (buffer == NULL) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + png_crc_read(png_ptr, buffer, length); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + /* TODO: also check that the keyword contents match the spec! */ + for (keyword_length = 0; + keyword_length < length && buffer[keyword_length] != 0; + ++keyword_length) + /* Empty loop to find end of name */ ; + + if (keyword_length > 79 || keyword_length < 1) + errmsg = "bad keyword"; + + /* zTXt must have some LZ data after the keyword, although it may expand to + * zero bytes; we need a '\0' at the end of the keyword, the compression type + * then the LZ data: + */ + else if (keyword_length + 3 > length) + errmsg = "truncated"; + + else if (buffer[keyword_length+1] != PNG_COMPRESSION_TYPE_BASE) + errmsg = "unknown compression type"; + + else + { + png_alloc_size_t uncompressed_length = PNG_SIZE_MAX; + + /* TODO: at present png_decompress_chunk imposes a single application + * level memory limit, this should be split to different values for iCCP + * and text chunks. + */ + if (png_decompress_chunk(png_ptr, length, keyword_length+2, + &uncompressed_length, 1/*terminate*/) == Z_STREAM_END) + { + png_text text; + + if (png_ptr->read_buffer == NULL) + errmsg="Read failure in png_handle_zTXt"; + else + { + /* It worked; png_ptr->read_buffer now looks like a tEXt chunk + * except for the extra compression type byte and the fact that + * it isn't necessarily '\0' terminated. + */ + buffer = png_ptr->read_buffer; + buffer[uncompressed_length+(keyword_length+2)] = 0; + + text.compression = PNG_TEXT_COMPRESSION_zTXt; + text.key = (png_charp)buffer; + text.text = (png_charp)(buffer + keyword_length+2); + text.text_length = uncompressed_length; + text.itxt_length = 0; + text.lang = NULL; + text.lang_key = NULL; + + if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0) + errmsg = "insufficient memory"; + } + } + + else + errmsg = png_ptr->zstream.msg; + } + + if (errmsg != NULL) + png_chunk_benign_error(png_ptr, errmsg); +} +#endif + +#ifdef PNG_READ_iTXt_SUPPORTED +/* Note: this does not correctly handle chunks that are > 64K under DOS */ +void /* PRIVATE */ +png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_const_charp errmsg = NULL; + png_bytep buffer; + png_uint_32 prefix_length; + + png_debug(1, "in png_handle_iTXt"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "no space in chunk cache"); + return; + } + } +#endif + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + png_ptr->mode |= PNG_AFTER_IDAT; + + buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/); + + if (buffer == NULL) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + png_crc_read(png_ptr, buffer, length); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + /* First the keyword. */ + for (prefix_length=0; + prefix_length < length && buffer[prefix_length] != 0; + ++prefix_length) + /* Empty loop */ ; + + /* Perform a basic check on the keyword length here. */ + if (prefix_length > 79 || prefix_length < 1) + errmsg = "bad keyword"; + + /* Expect keyword, compression flag, compression type, language, translated + * keyword (both may be empty but are 0 terminated) then the text, which may + * be empty. + */ + else if (prefix_length + 5 > length) + errmsg = "truncated"; + + else if (buffer[prefix_length+1] == 0 || + (buffer[prefix_length+1] == 1 && + buffer[prefix_length+2] == PNG_COMPRESSION_TYPE_BASE)) + { + int compressed = buffer[prefix_length+1] != 0; + png_uint_32 language_offset, translated_keyword_offset; + png_alloc_size_t uncompressed_length = 0; + + /* Now the language tag */ + prefix_length += 3; + language_offset = prefix_length; + + for (; prefix_length < length && buffer[prefix_length] != 0; + ++prefix_length) + /* Empty loop */ ; + + /* WARNING: the length may be invalid here, this is checked below. */ + translated_keyword_offset = ++prefix_length; + + for (; prefix_length < length && buffer[prefix_length] != 0; + ++prefix_length) + /* Empty loop */ ; + + /* prefix_length should now be at the trailing '\0' of the translated + * keyword, but it may already be over the end. None of this arithmetic + * can overflow because chunks are at most 2^31 bytes long, but on 16-bit + * systems the available allocation may overflow. + */ + ++prefix_length; + + if (compressed == 0 && prefix_length <= length) + uncompressed_length = length - prefix_length; + + else if (compressed != 0 && prefix_length < length) + { + uncompressed_length = PNG_SIZE_MAX; + + /* TODO: at present png_decompress_chunk imposes a single application + * level memory limit, this should be split to different values for + * iCCP and text chunks. + */ + if (png_decompress_chunk(png_ptr, length, prefix_length, + &uncompressed_length, 1/*terminate*/) == Z_STREAM_END) + buffer = png_ptr->read_buffer; + + else + errmsg = png_ptr->zstream.msg; + } + + else + errmsg = "truncated"; + + if (errmsg == NULL) + { + png_text text; + + buffer[uncompressed_length+prefix_length] = 0; + + if (compressed == 0) + text.compression = PNG_ITXT_COMPRESSION_NONE; + + else + text.compression = PNG_ITXT_COMPRESSION_zTXt; + + text.key = (png_charp)buffer; + text.lang = (png_charp)buffer + language_offset; + text.lang_key = (png_charp)buffer + translated_keyword_offset; + text.text = (png_charp)buffer + prefix_length; + text.text_length = 0; + text.itxt_length = uncompressed_length; + + if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0) + errmsg = "insufficient memory"; + } + } + + else + errmsg = "bad compression info"; + + if (errmsg != NULL) + png_chunk_benign_error(png_ptr, errmsg); +} +#endif + +#ifdef PNG_READ_APNG_SUPPORTED +void /* PRIVATE */ +png_handle_acTL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte data[8]; + png_uint_32 num_frames; + png_uint_32 num_plays; + png_uint_32 didSet; + + png_debug(1, "in png_handle_acTL"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + { + png_error(png_ptr, "Missing IHDR before acTL"); + } + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_warning(png_ptr, "Invalid acTL after IDAT skipped"); + png_crc_finish(png_ptr, length); + return; + } + else if ((png_ptr->mode & PNG_HAVE_acTL) != 0) + { + png_warning(png_ptr, "Duplicate acTL skipped"); + png_crc_finish(png_ptr, length); + return; + } + else if (length != 8) + { + png_warning(png_ptr, "acTL with invalid length skipped"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, data, 8); + png_crc_finish(png_ptr, 0); + + num_frames = png_get_uint_31(png_ptr, data); + num_plays = png_get_uint_31(png_ptr, data + 4); + + /* the set function will do error checking on num_frames */ + didSet = png_set_acTL(png_ptr, info_ptr, num_frames, num_plays); + if (didSet != 0) + png_ptr->mode |= PNG_HAVE_acTL; +} + +void /* PRIVATE */ +png_handle_fcTL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte data[22]; + png_uint_32 width; + png_uint_32 height; + png_uint_32 x_offset; + png_uint_32 y_offset; + png_uint_16 delay_num; + png_uint_16 delay_den; + png_byte dispose_op; + png_byte blend_op; + + png_debug(1, "in png_handle_fcTL"); + + png_ensure_sequence_number(png_ptr, length); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + { + png_error(png_ptr, "Missing IHDR before fcTL"); + } + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + /* for any frames other then the first this message may be misleading, + * but correct. PNG_HAVE_IDAT is unset before the frame head is read + * i can't think of a better message */ + png_warning(png_ptr, "Invalid fcTL after IDAT skipped"); + png_crc_finish(png_ptr, length-4); + return; + } + else if ((png_ptr->mode & PNG_HAVE_fcTL) != 0) + { + png_warning(png_ptr, "Duplicate fcTL within one frame skipped"); + png_crc_finish(png_ptr, length-4); + return; + } + else if (length != 26) + { + png_warning(png_ptr, "fcTL with invalid length skipped"); + png_crc_finish(png_ptr, length-4); + return; + } + + png_crc_read(png_ptr, data, 22); + png_crc_finish(png_ptr, 0); + + width = png_get_uint_31(png_ptr, data); + height = png_get_uint_31(png_ptr, data + 4); + x_offset = png_get_uint_31(png_ptr, data + 8); + y_offset = png_get_uint_31(png_ptr, data + 12); + delay_num = png_get_uint_16(data + 16); + delay_den = png_get_uint_16(data + 18); + dispose_op = data[20]; + blend_op = data[21]; + + if (png_ptr->num_frames_read == 0 && (x_offset != 0 || y_offset != 0)) + { + png_warning(png_ptr, "fcTL for the first frame must have zero offset"); + return; + } + + if (info_ptr != NULL) + { + if (png_ptr->num_frames_read == 0 && + (width != info_ptr->width || height != info_ptr->height)) + { + png_warning(png_ptr, "size in first frame's fcTL must match " + "the size in IHDR"); + return; + } + + /* The set function will do more error checking */ + png_set_next_frame_fcTL(png_ptr, info_ptr, width, height, + x_offset, y_offset, delay_num, delay_den, + dispose_op, blend_op); + + png_read_reinit(png_ptr, info_ptr); + + png_ptr->mode |= PNG_HAVE_fcTL; + } +} + +void /* PRIVATE */ +png_have_info(png_structp png_ptr, png_infop info_ptr) +{ + if ((info_ptr->valid & PNG_INFO_acTL) != 0 && + (info_ptr->valid & PNG_INFO_fcTL) == 0) + { + png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN; + info_ptr->num_frames++; + } +} + +void /* PRIVATE */ +png_handle_fdAT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_ensure_sequence_number(png_ptr, length); + + /* This function is only called from png_read_end(), png_read_info(), + * and png_push_read_chunk() which means that: + * - the user doesn't want to read this frame + * - or this is an out-of-place fdAT + * in either case it is safe to ignore the chunk with a warning */ + png_warning(png_ptr, "ignoring fdAT chunk"); + png_crc_finish(png_ptr, length - 4); + PNG_UNUSED(info_ptr) +} + +void /* PRIVATE */ +png_ensure_sequence_number(png_structp png_ptr, png_uint_32 length) +{ + png_byte data[4]; + png_uint_32 sequence_number; + + if (length < 4) + png_error(png_ptr, "invalid fcTL or fdAT chunk found"); + + png_crc_read(png_ptr, data, 4); + sequence_number = png_get_uint_31(png_ptr, data); + + if (sequence_number != png_ptr->next_seq_num) + png_error(png_ptr, "fcTL or fdAT chunk with out-of-order sequence " + "number found"); + + png_ptr->next_seq_num++; +} +#endif /* READ_APNG */ + +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED +/* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */ +static int +png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length) +{ + png_alloc_size_t limit = PNG_SIZE_MAX; + + if (png_ptr->unknown_chunk.data != NULL) + { + png_free(png_ptr, png_ptr->unknown_chunk.data); + png_ptr->unknown_chunk.data = NULL; + } + +# ifdef PNG_SET_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_malloc_max > 0 && + png_ptr->user_chunk_malloc_max < limit) + limit = png_ptr->user_chunk_malloc_max; + +# elif PNG_USER_CHUNK_MALLOC_MAX > 0 + if (PNG_USER_CHUNK_MALLOC_MAX < limit) + limit = PNG_USER_CHUNK_MALLOC_MAX; +# endif + + if (length <= limit) + { + PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name); + /* The following is safe because of the PNG_SIZE_MAX init above */ + png_ptr->unknown_chunk.size = (size_t)length/*SAFE*/; + /* 'mode' is a flag array, only the bottom four bits matter here */ + png_ptr->unknown_chunk.location = (png_byte)png_ptr->mode/*SAFE*/; + + if (length == 0) + png_ptr->unknown_chunk.data = NULL; + + else + { + /* Do a 'warn' here - it is handled below. */ + png_ptr->unknown_chunk.data = png_voidcast(png_bytep, + png_malloc_warn(png_ptr, length)); + } + } + + if (png_ptr->unknown_chunk.data == NULL && length > 0) + { + /* This is benign because we clean up correctly */ + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "unknown chunk exceeds memory limits"); + return 0; + } + + else + { + if (length > 0) + png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length); + png_crc_finish(png_ptr, 0); + return 1; + } +} +#endif /* READ_UNKNOWN_CHUNKS */ + +/* Handle an unknown, or known but disabled, chunk */ +void /* PRIVATE */ +png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr, + png_uint_32 length, int keep) +{ + int handled = 0; /* the chunk was handled */ + + png_debug(1, "in png_handle_unknown"); + +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED + /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing + * the bug which meant that setting a non-default behavior for a specific + * chunk would be ignored (the default was always used unless a user + * callback was installed). + * + * 'keep' is the value from the png_chunk_unknown_handling, the setting for + * this specific chunk_name, if PNG_HANDLE_AS_UNKNOWN_SUPPORTED, if not it + * will always be PNG_HANDLE_CHUNK_AS_DEFAULT and it needs to be set here. + * This is just an optimization to avoid multiple calls to the lookup + * function. + */ +# ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name); +# endif +# endif + + /* One of the following methods will read the chunk or skip it (at least one + * of these is always defined because this is the only way to switch on + * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) + */ +# ifdef PNG_READ_USER_CHUNKS_SUPPORTED + /* The user callback takes precedence over the chunk keep value, but the + * keep value is still required to validate a save of a critical chunk. + */ + if (png_ptr->read_user_chunk_fn != NULL) + { + if (png_cache_unknown_chunk(png_ptr, length) != 0) + { + /* Callback to user unknown chunk handler */ + int ret = (*(png_ptr->read_user_chunk_fn))(png_ptr, + &png_ptr->unknown_chunk); + + /* ret is: + * negative: An error occurred; png_chunk_error will be called. + * zero: The chunk was not handled, the chunk will be discarded + * unless png_set_keep_unknown_chunks has been used to set + * a 'keep' behavior for this particular chunk, in which + * case that will be used. A critical chunk will cause an + * error at this point unless it is to be saved. + * positive: The chunk was handled, libpng will ignore/discard it. + */ + if (ret < 0) + png_chunk_error(png_ptr, "error in user chunk"); + + else if (ret == 0) + { + /* If the keep value is 'default' or 'never' override it, but + * still error out on critical chunks unless the keep value is + * 'always' While this is weird it is the behavior in 1.4.12. + * A possible improvement would be to obey the value set for the + * chunk, but this would be an API change that would probably + * damage some applications. + * + * The png_app_warning below catches the case that matters, where + * the application has not set specific save or ignore for this + * chunk or global save or ignore. + */ + if (keep < PNG_HANDLE_CHUNK_IF_SAFE) + { +# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + if (png_ptr->unknown_default < PNG_HANDLE_CHUNK_IF_SAFE) + { + png_chunk_warning(png_ptr, "Saving unknown chunk:"); + png_app_warning(png_ptr, + "forcing save of an unhandled chunk;" + " please call png_set_keep_unknown_chunks"); + /* with keep = PNG_HANDLE_CHUNK_IF_SAFE */ + } +# endif + keep = PNG_HANDLE_CHUNK_IF_SAFE; + } + } + + else /* chunk was handled */ + { + handled = 1; + /* Critical chunks can be safely discarded at this point. */ + keep = PNG_HANDLE_CHUNK_NEVER; + } + } + + else + keep = PNG_HANDLE_CHUNK_NEVER; /* insufficient memory */ + } + + else + /* Use the SAVE_UNKNOWN_CHUNKS code or skip the chunk */ +# endif /* READ_USER_CHUNKS */ + +# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED + { + /* keep is currently just the per-chunk setting, if there was no + * setting change it to the global default now (not that this may + * still be AS_DEFAULT) then obtain the cache of the chunk if required, + * if not simply skip the chunk. + */ + if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT) + keep = png_ptr->unknown_default; + + if (keep == PNG_HANDLE_CHUNK_ALWAYS || + (keep == PNG_HANDLE_CHUNK_IF_SAFE && + PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))) + { + if (png_cache_unknown_chunk(png_ptr, length) == 0) + keep = PNG_HANDLE_CHUNK_NEVER; + } + + else + png_crc_finish(png_ptr, length); + } +# else +# ifndef PNG_READ_USER_CHUNKS_SUPPORTED +# error no method to support READ_UNKNOWN_CHUNKS +# endif + + { + /* If here there is no read callback pointer set and no support is + * compiled in to just save the unknown chunks, so simply skip this + * chunk. If 'keep' is something other than AS_DEFAULT or NEVER then + * the app has erroneously asked for unknown chunk saving when there + * is no support. + */ + if (keep > PNG_HANDLE_CHUNK_NEVER) + png_app_error(png_ptr, "no unknown chunk support available"); + + png_crc_finish(png_ptr, length); + } +# endif + +# ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED + /* Now store the chunk in the chunk list if appropriate, and if the limits + * permit it. + */ + if (keep == PNG_HANDLE_CHUNK_ALWAYS || + (keep == PNG_HANDLE_CHUNK_IF_SAFE && + PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))) + { +# ifdef PNG_USER_LIMITS_SUPPORTED + switch (png_ptr->user_chunk_cache_max) + { + case 2: + png_ptr->user_chunk_cache_max = 1; + png_chunk_benign_error(png_ptr, "no space in chunk cache"); + /* FALLTHROUGH */ + case 1: + /* NOTE: prior to 1.6.0 this case resulted in an unknown critical + * chunk being skipped, now there will be a hard error below. + */ + break; + + default: /* not at limit */ + --(png_ptr->user_chunk_cache_max); + /* FALLTHROUGH */ + case 0: /* no limit */ +# endif /* USER_LIMITS */ + /* Here when the limit isn't reached or when limits are compiled + * out; store the chunk. + */ + png_set_unknown_chunks(png_ptr, info_ptr, + &png_ptr->unknown_chunk, 1); + handled = 1; +# ifdef PNG_USER_LIMITS_SUPPORTED + break; + } +# endif + } +# else /* no store support: the chunk must be handled by the user callback */ + PNG_UNUSED(info_ptr) +# endif + + /* Regardless of the error handling below the cached data (if any) can be + * freed now. Notice that the data is not freed if there is a png_error, but + * it will be freed by destroy_read_struct. + */ + if (png_ptr->unknown_chunk.data != NULL) + png_free(png_ptr, png_ptr->unknown_chunk.data); + png_ptr->unknown_chunk.data = NULL; + +#else /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */ + /* There is no support to read an unknown chunk, so just skip it. */ + png_crc_finish(png_ptr, length); + PNG_UNUSED(info_ptr) + PNG_UNUSED(keep) +#endif /* !READ_UNKNOWN_CHUNKS */ + + /* Check for unhandled critical chunks */ + if (handled == 0 && PNG_CHUNK_CRITICAL(png_ptr->chunk_name)) + png_chunk_error(png_ptr, "unhandled critical chunk"); +} + +/* This function is called to verify that a chunk name is valid. + * This function can't have the "critical chunk check" incorporated + * into it, since in the future we will need to be able to call user + * functions to handle unknown critical chunks after we check that + * the chunk name itself is valid. + */ + +/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is: + * + * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) + */ + +void /* PRIVATE */ +png_check_chunk_name(png_const_structrp png_ptr, png_uint_32 chunk_name) +{ + int i; + png_uint_32 cn=chunk_name; + + png_debug(1, "in png_check_chunk_name"); + + for (i=1; i<=4; ++i) + { + int c = cn & 0xff; + + if (c < 65 || c > 122 || (c > 90 && c < 97)) + png_chunk_error(png_ptr, "invalid chunk type"); + + cn >>= 8; + } +} + +void /* PRIVATE */ +png_check_chunk_length(png_const_structrp png_ptr, png_uint_32 length) +{ + png_alloc_size_t limit = PNG_UINT_31_MAX; + +# ifdef PNG_SET_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_malloc_max > 0 && + png_ptr->user_chunk_malloc_max < limit) + limit = png_ptr->user_chunk_malloc_max; +# elif PNG_USER_CHUNK_MALLOC_MAX > 0 + if (PNG_USER_CHUNK_MALLOC_MAX < limit) + limit = PNG_USER_CHUNK_MALLOC_MAX; +# endif +#ifdef PNG_READ_APNG_SUPPORTED + if (png_ptr->chunk_name == png_IDAT || png_ptr->chunk_name == png_fdAT) +#else + if (png_ptr->chunk_name == png_IDAT) +#endif + { + png_alloc_size_t idat_limit = PNG_UINT_31_MAX; + size_t row_factor = + (size_t)png_ptr->width + * (size_t)png_ptr->channels + * (png_ptr->bit_depth > 8? 2: 1) + + 1 + + (png_ptr->interlaced? 6: 0); + if (png_ptr->height > PNG_UINT_32_MAX/row_factor) + idat_limit = PNG_UINT_31_MAX; + else + idat_limit = png_ptr->height * row_factor; + row_factor = row_factor > 32566? 32566 : row_factor; + idat_limit += 6 + 5*(idat_limit/row_factor+1); /* zlib+deflate overhead */ + idat_limit=idat_limit < PNG_UINT_31_MAX? idat_limit : PNG_UINT_31_MAX; + limit = limit < idat_limit? idat_limit : limit; + } + + if (length > limit) + { + png_debug2(0," length = %lu, limit = %lu", + (unsigned long)length,(unsigned long)limit); + png_chunk_error(png_ptr, "chunk data is too large"); + } +} + +/* Combines the row recently read in with the existing pixels in the row. This + * routine takes care of alpha and transparency if requested. This routine also + * handles the two methods of progressive display of interlaced images, + * depending on the 'display' value; if 'display' is true then the whole row + * (dp) is filled from the start by replicating the available pixels. If + * 'display' is false only those pixels present in the pass are filled in. + */ +void /* PRIVATE */ +png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display) +{ + unsigned int pixel_depth = png_ptr->transformed_pixel_depth; + png_const_bytep sp = png_ptr->row_buf + 1; + png_alloc_size_t row_width = png_ptr->width; + unsigned int pass = png_ptr->pass; + png_bytep end_ptr = 0; + png_byte end_byte = 0; + unsigned int end_mask; + + png_debug(1, "in png_combine_row"); + + /* Added in 1.5.6: it should not be possible to enter this routine until at + * least one row has been read from the PNG data and transformed. + */ + if (pixel_depth == 0) + png_error(png_ptr, "internal row logic error"); + + /* Added in 1.5.4: the pixel depth should match the information returned by + * any call to png_read_update_info at this point. Do not continue if we got + * this wrong. + */ + if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes != + PNG_ROWBYTES(pixel_depth, row_width)) + png_error(png_ptr, "internal row size calculation error"); + + /* Don't expect this to ever happen: */ + if (row_width == 0) + png_error(png_ptr, "internal row width error"); + + /* Preserve the last byte in cases where only part of it will be overwritten, + * the multiply below may overflow, we don't care because ANSI-C guarantees + * we get the low bits. + */ + end_mask = (pixel_depth * row_width) & 7; + if (end_mask != 0) + { + /* end_ptr == NULL is a flag to say do nothing */ + end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1; + end_byte = *end_ptr; +# ifdef PNG_READ_PACKSWAP_SUPPORTED + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) + /* little-endian byte */ + end_mask = (unsigned int)(0xff << end_mask); + + else /* big-endian byte */ +# endif + end_mask = 0xff >> end_mask; + /* end_mask is now the bits to *keep* from the destination row */ + } + + /* For non-interlaced images this reduces to a memcpy(). A memcpy() + * will also happen if interlacing isn't supported or if the application + * does not call png_set_interlace_handling(). In the latter cases the + * caller just gets a sequence of the unexpanded rows from each interlace + * pass. + */ +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) != 0 && + pass < 6 && (display == 0 || + /* The following copies everything for 'display' on passes 0, 2 and 4. */ + (display == 1 && (pass & 1) != 0))) + { + /* Narrow images may have no bits in a pass; the caller should handle + * this, but this test is cheap: + */ + if (row_width <= PNG_PASS_START_COL(pass)) + return; + + if (pixel_depth < 8) + { + /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit + * into 32 bits, then a single loop over the bytes using the four byte + * values in the 32-bit mask can be used. For the 'display' option the + * expanded mask may also not require any masking within a byte. To + * make this work the PACKSWAP option must be taken into account - it + * simply requires the pixels to be reversed in each byte. + * + * The 'regular' case requires a mask for each of the first 6 passes, + * the 'display' case does a copy for the even passes in the range + * 0..6. This has already been handled in the test above. + * + * The masks are arranged as four bytes with the first byte to use in + * the lowest bits (little-endian) regardless of the order (PACKSWAP or + * not) of the pixels in each byte. + * + * NOTE: the whole of this logic depends on the caller of this function + * only calling it on rows appropriate to the pass. This function only + * understands the 'x' logic; the 'y' logic is handled by the caller. + * + * The following defines allow generation of compile time constant bit + * masks for each pixel depth and each possibility of swapped or not + * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index, + * is in the range 0..7; and the result is 1 if the pixel is to be + * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B' + * for the block method. + * + * With some compilers a compile time expression of the general form: + * + * (shift >= 32) ? (a >> (shift-32)) : (b >> shift) + * + * Produces warnings with values of 'shift' in the range 33 to 63 + * because the right hand side of the ?: expression is evaluated by + * the compiler even though it isn't used. Microsoft Visual C (various + * versions) and the Intel C compiler are known to do this. To avoid + * this the following macros are used in 1.5.6. This is a temporary + * solution to avoid destabilizing the code during the release process. + */ +# if PNG_USE_COMPILE_TIME_MASKS +# define PNG_LSR(x,s) ((x)>>((s) & 0x1f)) +# define PNG_LSL(x,s) ((x)<<((s) & 0x1f)) +# else +# define PNG_LSR(x,s) ((x)>>(s)) +# define PNG_LSL(x,s) ((x)<<(s)) +# endif +# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\ + PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1) +# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\ + PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1) + + /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is + * little endian - the first pixel is at bit 0 - however the extra + * parameter 's' can be set to cause the mask position to be swapped + * within each byte, to match the PNG format. This is done by XOR of + * the shift with 7, 6 or 4 for bit depths 1, 2 and 4. + */ +# define PIXEL_MASK(p,x,d,s) \ + (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0)))) + + /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask. + */ +# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) +# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) + + /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp + * cases the result needs replicating, for the 4-bpp case the above + * generates a full 32 bits. + */ +# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1))) + +# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\ + S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\ + S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d) + +# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\ + B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\ + B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d) + +#if PNG_USE_COMPILE_TIME_MASKS + /* Utility macros to construct all the masks for a depth/swap + * combination. The 's' parameter says whether the format is PNG + * (big endian bytes) or not. Only the three odd-numbered passes are + * required for the display/block algorithm. + */ +# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\ + S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) } + +# define B_MASKS(d,s) { B_MASK(1,d,s), B_MASK(3,d,s), B_MASK(5,d,s) } + +# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2)) + + /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and + * then pass: + */ + static const png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] = + { + /* Little-endian byte masks for PACKSWAP */ + { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) }, + /* Normal (big-endian byte) masks - PNG format */ + { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) } + }; + + /* display_mask has only three entries for the odd passes, so index by + * pass>>1. + */ + static const png_uint_32 display_mask[2][3][3] = + { + /* Little-endian byte masks for PACKSWAP */ + { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) }, + /* Normal (big-endian byte) masks - PNG format */ + { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) } + }; + +# define MASK(pass,depth,display,png)\ + ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\ + row_mask[png][DEPTH_INDEX(depth)][pass]) + +#else /* !PNG_USE_COMPILE_TIME_MASKS */ + /* This is the runtime alternative: it seems unlikely that this will + * ever be either smaller or faster than the compile time approach. + */ +# define MASK(pass,depth,display,png)\ + ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png)) +#endif /* !USE_COMPILE_TIME_MASKS */ + + /* Use the appropriate mask to copy the required bits. In some cases + * the byte mask will be 0 or 0xff; optimize these cases. row_width is + * the number of pixels, but the code copies bytes, so it is necessary + * to special case the end. + */ + png_uint_32 pixels_per_byte = 8 / pixel_depth; + png_uint_32 mask; + +# ifdef PNG_READ_PACKSWAP_SUPPORTED + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) + mask = MASK(pass, pixel_depth, display, 0); + + else +# endif + mask = MASK(pass, pixel_depth, display, 1); + + for (;;) + { + png_uint_32 m; + + /* It doesn't matter in the following if png_uint_32 has more than + * 32 bits because the high bits always match those in m<<24; it is, + * however, essential to use OR here, not +, because of this. + */ + m = mask; + mask = (m >> 8) | (m << 24); /* rotate right to good compilers */ + m &= 0xff; + + if (m != 0) /* something to copy */ + { + if (m != 0xff) + *dp = (png_byte)((*dp & ~m) | (*sp & m)); + else + *dp = *sp; + } + + /* NOTE: this may overwrite the last byte with garbage if the image + * is not an exact number of bytes wide; libpng has always done + * this. + */ + if (row_width <= pixels_per_byte) + break; /* May need to restore part of the last byte */ + + row_width -= pixels_per_byte; + ++dp; + ++sp; + } + } + + else /* pixel_depth >= 8 */ + { + unsigned int bytes_to_copy, bytes_to_jump; + + /* Validate the depth - it must be a multiple of 8 */ + if (pixel_depth & 7) + png_error(png_ptr, "invalid user transform pixel depth"); + + pixel_depth >>= 3; /* now in bytes */ + row_width *= pixel_depth; + + /* Regardless of pass number the Adam 7 interlace always results in a + * fixed number of pixels to copy then to skip. There may be a + * different number of pixels to skip at the start though. + */ + { + unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth; + + row_width -= offset; + dp += offset; + sp += offset; + } + + /* Work out the bytes to copy. */ + if (display != 0) + { + /* When doing the 'block' algorithm the pixel in the pass gets + * replicated to adjacent pixels. This is why the even (0,2,4,6) + * passes are skipped above - the entire expanded row is copied. + */ + bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth; + + /* But don't allow this number to exceed the actual row width. */ + if (bytes_to_copy > row_width) + bytes_to_copy = (unsigned int)/*SAFE*/row_width; + } + + else /* normal row; Adam7 only ever gives us one pixel to copy. */ + bytes_to_copy = pixel_depth; + + /* In Adam7 there is a constant offset between where the pixels go. */ + bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth; + + /* And simply copy these bytes. Some optimization is possible here, + * depending on the value of 'bytes_to_copy'. Special case the low + * byte counts, which we know to be frequent. + * + * Notice that these cases all 'return' rather than 'break' - this + * avoids an unnecessary test on whether to restore the last byte + * below. + */ + switch (bytes_to_copy) + { + case 1: + for (;;) + { + *dp = *sp; + + if (row_width <= bytes_to_jump) + return; + + dp += bytes_to_jump; + sp += bytes_to_jump; + row_width -= bytes_to_jump; + } + + case 2: + /* There is a possibility of a partial copy at the end here; this + * slows the code down somewhat. + */ + do + { + dp[0] = sp[0]; dp[1] = sp[1]; + + if (row_width <= bytes_to_jump) + return; + + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; + } + while (row_width > 1); + + /* And there can only be one byte left at this point: */ + *dp = *sp; + return; + + case 3: + /* This can only be the RGB case, so each copy is exactly one + * pixel and it is not necessary to check for a partial copy. + */ + for (;;) + { + dp[0] = sp[0]; dp[1] = sp[1]; dp[2] = sp[2]; + + if (row_width <= bytes_to_jump) + return; + + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; + } + + default: +#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE + /* Check for double byte alignment and, if possible, use a + * 16-bit copy. Don't attempt this for narrow images - ones that + * are less than an interlace panel wide. Don't attempt it for + * wide bytes_to_copy either - use the memcpy there. + */ + if (bytes_to_copy < 16 /*else use memcpy*/ && + png_isaligned(dp, png_uint_16) && + png_isaligned(sp, png_uint_16) && + bytes_to_copy % (sizeof (png_uint_16)) == 0 && + bytes_to_jump % (sizeof (png_uint_16)) == 0) + { + /* Everything is aligned for png_uint_16 copies, but try for + * png_uint_32 first. + */ + if (png_isaligned(dp, png_uint_32) && + png_isaligned(sp, png_uint_32) && + bytes_to_copy % (sizeof (png_uint_32)) == 0 && + bytes_to_jump % (sizeof (png_uint_32)) == 0) + { + png_uint_32p dp32 = png_aligncast(png_uint_32p,dp); + png_const_uint_32p sp32 = png_aligncastconst( + png_const_uint_32p, sp); + size_t skip = (bytes_to_jump-bytes_to_copy) / + (sizeof (png_uint_32)); + + do + { + size_t c = bytes_to_copy; + do + { + *dp32++ = *sp32++; + c -= (sizeof (png_uint_32)); + } + while (c > 0); + + if (row_width <= bytes_to_jump) + return; + + dp32 += skip; + sp32 += skip; + row_width -= bytes_to_jump; + } + while (bytes_to_copy <= row_width); + + /* Get to here when the row_width truncates the final copy. + * There will be 1-3 bytes left to copy, so don't try the + * 16-bit loop below. + */ + dp = (png_bytep)dp32; + sp = (png_const_bytep)sp32; + do + *dp++ = *sp++; + while (--row_width > 0); + return; + } + + /* Else do it in 16-bit quantities, but only if the size is + * not too large. + */ + else + { + png_uint_16p dp16 = png_aligncast(png_uint_16p, dp); + png_const_uint_16p sp16 = png_aligncastconst( + png_const_uint_16p, sp); + size_t skip = (bytes_to_jump-bytes_to_copy) / + (sizeof (png_uint_16)); + + do + { + size_t c = bytes_to_copy; + do + { + *dp16++ = *sp16++; + c -= (sizeof (png_uint_16)); + } + while (c > 0); + + if (row_width <= bytes_to_jump) + return; + + dp16 += skip; + sp16 += skip; + row_width -= bytes_to_jump; + } + while (bytes_to_copy <= row_width); + + /* End of row - 1 byte left, bytes_to_copy > row_width: */ + dp = (png_bytep)dp16; + sp = (png_const_bytep)sp16; + do + *dp++ = *sp++; + while (--row_width > 0); + return; + } + } +#endif /* ALIGN_TYPE code */ + + /* The true default - use a memcpy: */ + for (;;) + { + memcpy(dp, sp, bytes_to_copy); + + if (row_width <= bytes_to_jump) + return; + + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; + if (bytes_to_copy > row_width) + bytes_to_copy = (unsigned int)/*SAFE*/row_width; + } + } + + /* NOT REACHED*/ + } /* pixel_depth >= 8 */ + + /* Here if pixel_depth < 8 to check 'end_ptr' below. */ + } + else +#endif /* READ_INTERLACING */ + + /* If here then the switch above wasn't used so just memcpy the whole row + * from the temporary row buffer (notice that this overwrites the end of the + * destination row if it is a partial byte.) + */ + memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width)); + + /* Restore the overwritten bits from the last byte if necessary. */ + if (end_ptr != NULL) + *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask)); +} + +#ifdef PNG_READ_INTERLACING_SUPPORTED +void /* PRIVATE */ +png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass, + png_uint_32 transformations /* Because these may affect the byte layout */) +{ + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + /* Offset to next interlace block */ + static const unsigned int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + png_debug(1, "in png_do_read_interlace"); + if (row != NULL && row_info != NULL) + { + png_uint_32 final_width; + + final_width = row_info->width * png_pass_inc[pass]; + + switch (row_info->pixel_depth) + { + case 1: + { + png_bytep sp = row + (size_t)((row_info->width - 1) >> 3); + png_bytep dp = row + (size_t)((final_width - 1) >> 3); + unsigned int sshift, dshift; + unsigned int s_start, s_end; + int s_inc; + int jstop = (int)png_pass_inc[pass]; + png_byte v; + png_uint_32 i; + int j; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if ((transformations & PNG_PACKSWAP) != 0) + { + sshift = ((row_info->width + 7) & 0x07); + dshift = ((final_width + 7) & 0x07); + s_start = 7; + s_end = 0; + s_inc = -1; + } + + else +#endif + { + sshift = 7 - ((row_info->width + 7) & 0x07); + dshift = 7 - ((final_width + 7) & 0x07); + s_start = 0; + s_end = 7; + s_inc = 1; + } + + for (i = 0; i < row_info->width; i++) + { + v = (png_byte)((*sp >> sshift) & 0x01); + for (j = 0; j < jstop; j++) + { + unsigned int tmp = *dp & (0x7f7f >> (7 - dshift)); + tmp |= (unsigned int)(v << dshift); + *dp = (png_byte)(tmp & 0xff); + + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + + else + dshift = (unsigned int)((int)dshift + s_inc); + } + + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + + else + sshift = (unsigned int)((int)sshift + s_inc); + } + break; + } + + case 2: + { + png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2); + png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2); + unsigned int sshift, dshift; + unsigned int s_start, s_end; + int s_inc; + int jstop = (int)png_pass_inc[pass]; + png_uint_32 i; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if ((transformations & PNG_PACKSWAP) != 0) + { + sshift = (((row_info->width + 3) & 0x03) << 1); + dshift = (((final_width + 3) & 0x03) << 1); + s_start = 6; + s_end = 0; + s_inc = -2; + } + + else +#endif + { + sshift = ((3 - ((row_info->width + 3) & 0x03)) << 1); + dshift = ((3 - ((final_width + 3) & 0x03)) << 1); + s_start = 0; + s_end = 6; + s_inc = 2; + } + + for (i = 0; i < row_info->width; i++) + { + png_byte v; + int j; + + v = (png_byte)((*sp >> sshift) & 0x03); + for (j = 0; j < jstop; j++) + { + unsigned int tmp = *dp & (0x3f3f >> (6 - dshift)); + tmp |= (unsigned int)(v << dshift); + *dp = (png_byte)(tmp & 0xff); + + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + + else + dshift = (unsigned int)((int)dshift + s_inc); + } + + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + + else + sshift = (unsigned int)((int)sshift + s_inc); + } + break; + } + + case 4: + { + png_bytep sp = row + (size_t)((row_info->width - 1) >> 1); + png_bytep dp = row + (size_t)((final_width - 1) >> 1); + unsigned int sshift, dshift; + unsigned int s_start, s_end; + int s_inc; + png_uint_32 i; + int jstop = (int)png_pass_inc[pass]; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if ((transformations & PNG_PACKSWAP) != 0) + { + sshift = (((row_info->width + 1) & 0x01) << 2); + dshift = (((final_width + 1) & 0x01) << 2); + s_start = 4; + s_end = 0; + s_inc = -4; + } + + else +#endif + { + sshift = ((1 - ((row_info->width + 1) & 0x01)) << 2); + dshift = ((1 - ((final_width + 1) & 0x01)) << 2); + s_start = 0; + s_end = 4; + s_inc = 4; + } + + for (i = 0; i < row_info->width; i++) + { + png_byte v = (png_byte)((*sp >> sshift) & 0x0f); + int j; + + for (j = 0; j < jstop; j++) + { + unsigned int tmp = *dp & (0xf0f >> (4 - dshift)); + tmp |= (unsigned int)(v << dshift); + *dp = (png_byte)(tmp & 0xff); + + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + + else + dshift = (unsigned int)((int)dshift + s_inc); + } + + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + + else + sshift = (unsigned int)((int)sshift + s_inc); + } + break; + } + + default: + { + size_t pixel_bytes = (row_info->pixel_depth >> 3); + + png_bytep sp = row + (size_t)(row_info->width - 1) + * pixel_bytes; + + png_bytep dp = row + (size_t)(final_width - 1) * pixel_bytes; + + int jstop = (int)png_pass_inc[pass]; + png_uint_32 i; + + for (i = 0; i < row_info->width; i++) + { + png_byte v[8]; /* SAFE; pixel_depth does not exceed 64 */ + int j; + + memcpy(v, sp, pixel_bytes); + + for (j = 0; j < jstop; j++) + { + memcpy(dp, v, pixel_bytes); + dp -= pixel_bytes; + } + + sp -= pixel_bytes; + } + break; + } + } + + row_info->width = final_width; + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width); + } +#ifndef PNG_READ_PACKSWAP_SUPPORTED + PNG_UNUSED(transformations) /* Silence compiler warning */ +#endif +} +#endif /* READ_INTERLACING */ + +static void +png_read_filter_row_sub(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + size_t i; + size_t istop = row_info->rowbytes; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_bytep rp = row + bpp; + + PNG_UNUSED(prev_row) + + for (i = bpp; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); + rp++; + } +} + +static void +png_read_filter_row_up(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + size_t i; + size_t istop = row_info->rowbytes; + png_bytep rp = row; + png_const_bytep pp = prev_row; + + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); + rp++; + } +} + +static void +png_read_filter_row_avg(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + size_t i; + png_bytep rp = row; + png_const_bytep pp = prev_row; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + size_t istop = row_info->rowbytes - bpp; + + for (i = 0; i < bpp; i++) + { + *rp = (png_byte)(((int)(*rp) + + ((int)(*pp++) / 2 )) & 0xff); + + rp++; + } + + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); + + rp++; + } +} + +static void +png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp_end = row + row_info->rowbytes; + int a, c; + + /* First pixel/byte */ + c = *prev_row++; + a = *row + c; + *row++ = (png_byte)a; + + /* Remainder */ + while (row < rp_end) + { + int b, pa, pb, pc, p; + + a &= 0xff; /* From previous iteration or start */ + b = *prev_row++; + + p = b - c; + pc = a - c; + +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + + /* Find the best predictor, the least of pa, pb, pc favoring the earlier + * ones in the case of a tie. + */ + if (pb < pa) + { + pa = pb; a = b; + } + if (pc < pa) a = c; + + /* Calculate the current pixel in a, and move the previous row pixel to c + * for the next time round the loop + */ + c = b; + a += *row; + *row++ = (png_byte)a; + } +} + +static void +png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_bytep rp_end = row + bpp; + + /* Process the first pixel in the row completely (this is the same as 'up' + * because there is only one candidate predictor for the first row). + */ + while (row < rp_end) + { + int a = *row + *prev_row++; + *row++ = (png_byte)a; + } + + /* Remainder */ + rp_end = rp_end + (row_info->rowbytes - bpp); + + while (row < rp_end) + { + int a, b, c, pa, pb, pc, p; + + c = *(prev_row - bpp); + a = *(row - bpp); + b = *prev_row++; + + p = b - c; + pc = a - c; + +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + + if (pb < pa) + { + pa = pb; a = b; + } + if (pc < pa) a = c; + + a += *row; + *row++ = (png_byte)a; + } +} + +static void +png_init_filter_functions(png_structrp pp) + /* This function is called once for every PNG image (except for PNG images + * that only use PNG_FILTER_VALUE_NONE for all rows) to set the + * implementations required to reverse the filtering of PNG rows. Reversing + * the filter is the first transformation performed on the row data. It is + * performed in place, therefore an implementation can be selected based on + * the image pixel format. If the implementation depends on image width then + * take care to ensure that it works correctly if the image is interlaced - + * interlacing causes the actual row width to vary. + */ +{ + unsigned int bpp = (pp->pixel_depth + 7) >> 3; + + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub; + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg; + if (bpp == 1) + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth_1byte_pixel; + else + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth_multibyte_pixel; + +#ifdef PNG_FILTER_OPTIMIZATIONS + /* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to + * call to install hardware optimizations for the above functions; simply + * replace whatever elements of the pp->read_filter[] array with a hardware + * specific (or, for that matter, generic) optimization. + * + * To see an example of this examine what configure.ac does when + * --enable-arm-neon is specified on the command line. + */ + PNG_FILTER_OPTIMIZATIONS(pp, bpp); +#endif +} + +void /* PRIVATE */ +png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row, + png_const_bytep prev_row, int filter) +{ + /* OPTIMIZATION: DO NOT MODIFY THIS FUNCTION, instead #define + * PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic + * implementations. See png_init_filter_functions above. + */ + if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST) + { + if (pp->read_filter[0] == NULL) + png_init_filter_functions(pp); + + pp->read_filter[filter-1](row_info, row, prev_row); + } +} + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +void /* PRIVATE */ +png_read_IDAT_data(png_structrp png_ptr, png_bytep output, + png_alloc_size_t avail_out) +{ + /* Loop reading IDATs and decompressing the result into output[avail_out] */ + png_ptr->zstream.next_out = output; + png_ptr->zstream.avail_out = 0; /* safety: set below */ + + if (output == NULL) + avail_out = 0; + + do + { + int ret; + png_byte tmpbuf[PNG_INFLATE_BUF_SIZE]; + + if (png_ptr->zstream.avail_in == 0) + { + uInt avail_in; + png_bytep buffer; + +#ifdef PNG_READ_APNG_SUPPORTED + png_uint_32 bytes_to_skip = 0; + + while (png_ptr->idat_size == 0 || bytes_to_skip != 0) + { + png_crc_finish(png_ptr, bytes_to_skip); + bytes_to_skip = 0; + + png_ptr->idat_size = png_read_chunk_header(png_ptr); + if (png_ptr->num_frames_read == 0) + { + if (png_ptr->chunk_name != png_IDAT) + png_error(png_ptr, "Not enough image data"); + } + else + { + if (png_ptr->chunk_name == png_IEND) + png_error(png_ptr, "Not enough image data"); + if (png_ptr->chunk_name != png_fdAT) + { + png_warning(png_ptr, "Skipped (ignored) a chunk " + "between APNG chunks"); + bytes_to_skip = png_ptr->idat_size; + continue; + } + + png_ensure_sequence_number(png_ptr, png_ptr->idat_size); + + png_ptr->idat_size -= 4; + } + } +#else + while (png_ptr->idat_size == 0) + { + png_crc_finish(png_ptr, 0); + + png_ptr->idat_size = png_read_chunk_header(png_ptr); + /* This is an error even in the 'check' case because the code just + * consumed a non-IDAT header. + */ + if (png_ptr->chunk_name != png_IDAT) + png_error(png_ptr, "Not enough image data"); + } +#endif /* READ_APNG */ + + avail_in = png_ptr->IDAT_read_size; + + if (avail_in > png_ptr->idat_size) + avail_in = (uInt)png_ptr->idat_size; + + /* A PNG with a gradually increasing IDAT size will defeat this attempt + * to minimize memory usage by causing lots of re-allocs, but + * realistically doing IDAT_read_size re-allocs is not likely to be a + * big problem. + */ + buffer = png_read_buffer(png_ptr, avail_in, 0/*error*/); + + png_crc_read(png_ptr, buffer, avail_in); + png_ptr->idat_size -= avail_in; + + png_ptr->zstream.next_in = buffer; + png_ptr->zstream.avail_in = avail_in; + } + + /* And set up the output side. */ + if (output != NULL) /* standard read */ + { + uInt out = ZLIB_IO_MAX; + + if (out > avail_out) + out = (uInt)avail_out; + + avail_out -= out; + png_ptr->zstream.avail_out = out; + } + + else /* after last row, checking for end */ + { + png_ptr->zstream.next_out = tmpbuf; + png_ptr->zstream.avail_out = (sizeof tmpbuf); + } + + /* Use NO_FLUSH; this gives zlib the maximum opportunity to optimize the + * process. If the LZ stream is truncated the sequential reader will + * terminally damage the stream, above, by reading the chunk header of the + * following chunk (it then exits with png_error). + * + * TODO: deal more elegantly with truncated IDAT lists. + */ + ret = PNG_INFLATE(png_ptr, Z_NO_FLUSH); + + /* Take the unconsumed output back. */ + if (output != NULL) + avail_out += png_ptr->zstream.avail_out; + + else /* avail_out counts the extra bytes */ + avail_out += (sizeof tmpbuf) - png_ptr->zstream.avail_out; + + png_ptr->zstream.avail_out = 0; + + if (ret == Z_STREAM_END) + { + /* Do this for safety; we won't read any more into this row. */ + png_ptr->zstream.next_out = NULL; + + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; +#ifdef PNG_READ_APNG_SUPPORTED + png_ptr->num_frames_read++; +#endif + + if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0) + png_chunk_benign_error(png_ptr, "Extra compressed data"); + break; + } + + if (ret != Z_OK) + { + png_zstream_error(png_ptr, ret); + + if (output != NULL) + png_chunk_error(png_ptr, png_ptr->zstream.msg); + + else /* checking */ + { + png_chunk_benign_error(png_ptr, png_ptr->zstream.msg); + return; + } + } + } while (avail_out > 0); + + if (avail_out > 0) + { + /* The stream ended before the image; this is the same as too few IDATs so + * should be handled the same way. + */ + if (output != NULL) + png_error(png_ptr, "Not enough image data"); + + else /* the deflate stream contained extra data */ + png_chunk_benign_error(png_ptr, "Too much image data"); + } +} + +void /* PRIVATE */ +png_read_finish_IDAT(png_structrp png_ptr) +{ + /* We don't need any more data and the stream should have ended, however the + * LZ end code may actually not have been processed. In this case we must + * read it otherwise stray unread IDAT data or, more likely, an IDAT chunk + * may still remain to be consumed. + */ + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) + { + /* The NULL causes png_read_IDAT_data to swallow any remaining bytes in + * the compressed stream, but the stream may be damaged too, so even after + * this call we may need to terminate the zstream ownership. + */ + png_read_IDAT_data(png_ptr, NULL, 0); + png_ptr->zstream.next_out = NULL; /* safety */ + + /* Now clear everything out for safety; the following may not have been + * done. + */ + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) + { + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; + } + } + + /* If the zstream has not been released do it now *and* terminate the reading + * of the final IDAT chunk. + */ + if (png_ptr->zowner == png_IDAT) + { + /* Always do this; the pointers otherwise point into the read buffer. */ + png_ptr->zstream.next_in = NULL; + png_ptr->zstream.avail_in = 0; + + /* Now we no longer own the zstream. */ + png_ptr->zowner = 0; + + /* The slightly weird semantics of the sequential IDAT reading is that we + * are always in or at the end of an IDAT chunk, so we always need to do a + * crc_finish here. If idat_size is non-zero we also need to read the + * spurious bytes at the end of the chunk now. + */ + (void)png_crc_finish(png_ptr, png_ptr->idat_size); + } +} + +void /* PRIVATE */ +png_read_finish_row(png_structrp png_ptr) +{ + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static const png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static const png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; + + png_debug(1, "in png_read_finish_row"); + png_ptr->row_number++; + if (png_ptr->row_number < png_ptr->num_rows) + return; + + if (png_ptr->interlaced != 0) + { + png_ptr->row_number = 0; + + /* TO DO: don't do this if prev_row isn't needed (requires + * read-ahead of the next row's filter byte. + */ + memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + + do + { + png_ptr->pass++; + + if (png_ptr->pass >= 7) + break; + + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + if ((png_ptr->transformations & PNG_INTERLACE) == 0) + { + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + } + + else /* if (png_ptr->transformations & PNG_INTERLACE) */ + break; /* libpng deinterlacing sees every row */ + + } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0); + + if (png_ptr->pass < 7) + return; + } + + /* Here after at the end of the last row of the last pass. */ + png_read_finish_IDAT(png_ptr); +} +#endif /* SEQUENTIAL_READ */ + +void /* PRIVATE */ +png_read_start_row(png_structrp png_ptr) +{ + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static const png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static const png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; + + unsigned int max_pixel_depth; + size_t row_bytes; + + png_debug(1, "in png_read_start_row"); + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + png_init_read_transformations(png_ptr); +#endif + if (png_ptr->interlaced != 0) + { + if ((png_ptr->transformations & PNG_INTERLACE) == 0) + png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - + png_pass_ystart[0]) / png_pass_yinc[0]; + + else + png_ptr->num_rows = png_ptr->height; + + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + } + + else + { + png_ptr->num_rows = png_ptr->height; + png_ptr->iwidth = png_ptr->width; + } + + max_pixel_depth = (unsigned int)png_ptr->pixel_depth; + + /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpler set of + * calculations to calculate the final pixel depth, then + * png_do_read_transforms actually does the transforms. This means that the + * code which effectively calculates this value is actually repeated in three + * separate places. They must all match. Innocent changes to the order of + * transformations can and will break libpng in a way that causes memory + * overwrites. + * + * TODO: fix this. + */ +#ifdef PNG_READ_PACK_SUPPORTED + if ((png_ptr->transformations & PNG_PACK) != 0 && png_ptr->bit_depth < 8) + max_pixel_depth = 8; +#endif + +#ifdef PNG_READ_EXPAND_SUPPORTED + if ((png_ptr->transformations & PNG_EXPAND) != 0) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (png_ptr->num_trans != 0) + max_pixel_depth = 32; + + else + max_pixel_depth = 24; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + if (max_pixel_depth < 8) + max_pixel_depth = 8; + + if (png_ptr->num_trans != 0) + max_pixel_depth *= 2; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + if (png_ptr->num_trans != 0) + { + max_pixel_depth *= 4; + max_pixel_depth /= 3; + } + } + } +#endif + +#ifdef PNG_READ_EXPAND_16_SUPPORTED + if ((png_ptr->transformations & PNG_EXPAND_16) != 0) + { +# ifdef PNG_READ_EXPAND_SUPPORTED + /* In fact it is an error if it isn't supported, but checking is + * the safe way. + */ + if ((png_ptr->transformations & PNG_EXPAND) != 0) + { + if (png_ptr->bit_depth < 16) + max_pixel_depth *= 2; + } + else +# endif + png_ptr->transformations &= ~PNG_EXPAND_16; + } +#endif + +#ifdef PNG_READ_FILLER_SUPPORTED + if ((png_ptr->transformations & (PNG_FILLER)) != 0) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + if (max_pixel_depth <= 8) + max_pixel_depth = 16; + + else + max_pixel_depth = 32; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB || + png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (max_pixel_depth <= 32) + max_pixel_depth = 32; + + else + max_pixel_depth = 64; + } + } +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0) + { + if ( +#ifdef PNG_READ_EXPAND_SUPPORTED + (png_ptr->num_trans != 0 && + (png_ptr->transformations & PNG_EXPAND) != 0) || +#endif +#ifdef PNG_READ_FILLER_SUPPORTED + (png_ptr->transformations & (PNG_FILLER)) != 0 || +#endif + png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (max_pixel_depth <= 16) + max_pixel_depth = 32; + + else + max_pixel_depth = 64; + } + + else + { + if (max_pixel_depth <= 8) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + max_pixel_depth = 32; + + else + max_pixel_depth = 24; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + max_pixel_depth = 64; + + else + max_pixel_depth = 48; + } + } +#endif + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \ +defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) + if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) + { + unsigned int user_pixel_depth = png_ptr->user_transform_depth * + png_ptr->user_transform_channels; + + if (user_pixel_depth > max_pixel_depth) + max_pixel_depth = user_pixel_depth; + } +#endif + + /* This value is stored in png_struct and double checked in the row read + * code. + */ + png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth; + png_ptr->transformed_pixel_depth = 0; /* calculated on demand */ + + /* Align the width on the next larger 8 pixels. Mainly used + * for interlacing + */ + row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7)); + /* Calculate the maximum bytes needed, adding a byte and a pixel + * for safety's sake + */ + row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) + + 1 + ((max_pixel_depth + 7) >> 3U); + +#ifdef PNG_MAX_MALLOC_64K + if (row_bytes > (png_uint_32)65536L) + png_error(png_ptr, "This image requires a row greater than 64KB"); +#endif + + if (row_bytes + 48 > png_ptr->old_big_row_buf_size) + { + png_free(png_ptr, png_ptr->big_row_buf); + png_free(png_ptr, png_ptr->big_prev_row); + + if (png_ptr->interlaced != 0) + png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr, + row_bytes + 48); + + else + png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48); + + png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48); + +#ifdef PNG_ALIGNED_MEMORY_SUPPORTED + /* Use 16-byte aligned memory for row_buf with at least 16 bytes + * of padding before and after row_buf; treat prev_row similarly. + * NOTE: the alignment is to the start of the pixels, one beyond the start + * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this + * was incorrect; the filter byte was aligned, which had the exact + * opposite effect of that intended. + */ + { + png_bytep temp = png_ptr->big_row_buf + 32; + int extra = (int)((temp - (png_bytep)0) & 0x0f); + png_ptr->row_buf = temp - extra - 1/*filter byte*/; + + temp = png_ptr->big_prev_row + 32; + extra = (int)((temp - (png_bytep)0) & 0x0f); + png_ptr->prev_row = temp - extra - 1/*filter byte*/; + } + +#else + /* Use 31 bytes of padding before and 17 bytes after row_buf. */ + png_ptr->row_buf = png_ptr->big_row_buf + 31; + png_ptr->prev_row = png_ptr->big_prev_row + 31; +#endif + png_ptr->old_big_row_buf_size = row_bytes + 48; + } + +#ifdef PNG_MAX_MALLOC_64K + if (png_ptr->rowbytes > 65535) + png_error(png_ptr, "This image requires a row greater than 64KB"); + +#endif + if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1)) + png_error(png_ptr, "Row has too many bytes to allocate in memory"); + + memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + + png_debug1(3, "width = %u,", png_ptr->width); + png_debug1(3, "height = %u,", png_ptr->height); + png_debug1(3, "iwidth = %u,", png_ptr->iwidth); + png_debug1(3, "num_rows = %u,", png_ptr->num_rows); + png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes); + png_debug1(3, "irowbytes = %lu", + (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1); + + /* The sequential reader needs a buffer for IDAT, but the progressive reader + * does not, so free the read buffer now regardless; the sequential reader + * reallocates it on demand. + */ + if (png_ptr->read_buffer != NULL) + { + png_bytep buffer = png_ptr->read_buffer; + + png_ptr->read_buffer_size = 0; + png_ptr->read_buffer = NULL; + png_free(png_ptr, buffer); + } + + /* Finally claim the zstream for the inflate of the IDAT data, use the bits + * value from the stream (note that this will result in a fatal error if the + * IDAT stream has a bogus deflate header window_bits value, but this should + * not be happening any longer!) + */ + if (png_inflate_claim(png_ptr, png_IDAT) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + + png_ptr->flags |= PNG_FLAG_ROW_INIT; +} + +#ifdef PNG_READ_APNG_SUPPORTED +/* This function is to be called after the main IDAT set has been read and + * before a new IDAT is read. It resets some parts of png_ptr + * to make them usable by the read functions again */ +void /* PRIVATE */ +png_read_reset(png_structp png_ptr) +{ + png_ptr->mode &= ~PNG_HAVE_IDAT; + png_ptr->mode &= ~PNG_AFTER_IDAT; + png_ptr->row_number = 0; + png_ptr->pass = 0; +} + +void /* PRIVATE */ +png_read_reinit(png_structp png_ptr, png_infop info_ptr) +{ + png_ptr->width = info_ptr->next_frame_width; + png_ptr->height = info_ptr->next_frame_height; + png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->width); + png_ptr->info_rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, + png_ptr->width); + if (png_ptr->prev_row != NULL) + memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); +} + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +/* same as png_read_reset() but for the progressive reader */ +void /* PRIVATE */ +png_progressive_read_reset(png_structp png_ptr) +{ +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static PNG_CONST png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; + + if (png_ptr->interlaced != 0) + { + if ((png_ptr->transformations & PNG_INTERLACE) == 0) + png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - + png_pass_ystart[0]) / png_pass_yinc[0]; + else + png_ptr->num_rows = png_ptr->height; + + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + } + else +#endif /* READ_INTERLACING */ + { + png_ptr->num_rows = png_ptr->height; + png_ptr->iwidth = png_ptr->width; + } + png_ptr->flags &= ~PNG_FLAG_ZSTREAM_ENDED; + if (inflateReset(&(png_ptr->zstream)) != Z_OK) + png_error(png_ptr, "inflateReset failed"); + png_ptr->zstream.avail_in = 0; + png_ptr->zstream.next_in = 0; + png_ptr->zstream.next_out = png_ptr->row_buf; + png_ptr->zstream.avail_out = (uInt)PNG_ROWBYTES(png_ptr->pixel_depth, + png_ptr->iwidth) + 1; +} +#endif /* PROGRESSIVE_READ */ +#endif /* READ_APNG */ +#endif /* READ */ diff --git a/media/libpng/pngset.c b/media/libpng/pngset.c new file mode 100644 index 0000000000..bdc6abc0f0 --- /dev/null +++ b/media/libpng/pngset.c @@ -0,0 +1,1947 @@ + +/* pngset.c - storage of image information into info struct + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * The functions here are used during reads to store data from the file + * into the info struct, and during writes to store application data + * into the info struct for writing into the file. This abstracts the + * info struct and allows us to change the structure in the future. + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +#ifdef PNG_bKGD_SUPPORTED +void PNGAPI +png_set_bKGD(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_color_16p background) +{ + png_debug1(1, "in %s storage function", "bKGD"); + + if (png_ptr == NULL || info_ptr == NULL || background == NULL) + return; + + info_ptr->background = *background; + info_ptr->valid |= PNG_INFO_bKGD; +} +#endif + +#ifdef PNG_cHRM_SUPPORTED +void PNGFAPI +png_set_cHRM_fixed(png_const_structrp png_ptr, png_inforp info_ptr, + png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x, + png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y, + png_fixed_point blue_x, png_fixed_point blue_y) +{ + png_xy xy; + + png_debug1(1, "in %s storage function", "cHRM fixed"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + xy.redx = red_x; + xy.redy = red_y; + xy.greenx = green_x; + xy.greeny = green_y; + xy.bluex = blue_x; + xy.bluey = blue_y; + xy.whitex = white_x; + xy.whitey = white_y; + + if (png_colorspace_set_chromaticities(png_ptr, &info_ptr->colorspace, &xy, + 2/* override with app values*/) != 0) + info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM; + + png_colorspace_sync_info(png_ptr, info_ptr); +} + +void PNGFAPI +png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_inforp info_ptr, + png_fixed_point int_red_X, png_fixed_point int_red_Y, + png_fixed_point int_red_Z, png_fixed_point int_green_X, + png_fixed_point int_green_Y, png_fixed_point int_green_Z, + png_fixed_point int_blue_X, png_fixed_point int_blue_Y, + png_fixed_point int_blue_Z) +{ + png_XYZ XYZ; + + png_debug1(1, "in %s storage function", "cHRM XYZ fixed"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + XYZ.red_X = int_red_X; + XYZ.red_Y = int_red_Y; + XYZ.red_Z = int_red_Z; + XYZ.green_X = int_green_X; + XYZ.green_Y = int_green_Y; + XYZ.green_Z = int_green_Z; + XYZ.blue_X = int_blue_X; + XYZ.blue_Y = int_blue_Y; + XYZ.blue_Z = int_blue_Z; + + if (png_colorspace_set_endpoints(png_ptr, &info_ptr->colorspace, + &XYZ, 2) != 0) + info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM; + + png_colorspace_sync_info(png_ptr, info_ptr); +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_cHRM(png_const_structrp png_ptr, png_inforp info_ptr, + double white_x, double white_y, double red_x, double red_y, + double green_x, double green_y, double blue_x, double blue_y) +{ + png_set_cHRM_fixed(png_ptr, info_ptr, + png_fixed(png_ptr, white_x, "cHRM White X"), + png_fixed(png_ptr, white_y, "cHRM White Y"), + png_fixed(png_ptr, red_x, "cHRM Red X"), + png_fixed(png_ptr, red_y, "cHRM Red Y"), + png_fixed(png_ptr, green_x, "cHRM Green X"), + png_fixed(png_ptr, green_y, "cHRM Green Y"), + png_fixed(png_ptr, blue_x, "cHRM Blue X"), + png_fixed(png_ptr, blue_y, "cHRM Blue Y")); +} + +void PNGAPI +png_set_cHRM_XYZ(png_const_structrp png_ptr, png_inforp info_ptr, double red_X, + double red_Y, double red_Z, double green_X, double green_Y, double green_Z, + double blue_X, double blue_Y, double blue_Z) +{ + png_set_cHRM_XYZ_fixed(png_ptr, info_ptr, + png_fixed(png_ptr, red_X, "cHRM Red X"), + png_fixed(png_ptr, red_Y, "cHRM Red Y"), + png_fixed(png_ptr, red_Z, "cHRM Red Z"), + png_fixed(png_ptr, green_X, "cHRM Green X"), + png_fixed(png_ptr, green_Y, "cHRM Green Y"), + png_fixed(png_ptr, green_Z, "cHRM Green Z"), + png_fixed(png_ptr, blue_X, "cHRM Blue X"), + png_fixed(png_ptr, blue_Y, "cHRM Blue Y"), + png_fixed(png_ptr, blue_Z, "cHRM Blue Z")); +} +# endif /* FLOATING_POINT */ + +#endif /* cHRM */ + +#ifdef PNG_eXIf_SUPPORTED +void PNGAPI +png_set_eXIf(png_const_structrp png_ptr, png_inforp info_ptr, + png_bytep eXIf_buf) +{ + png_warning(png_ptr, "png_set_eXIf does not work; use png_set_eXIf_1"); + PNG_UNUSED(info_ptr) + PNG_UNUSED(eXIf_buf) +} + +void PNGAPI +png_set_eXIf_1(png_const_structrp png_ptr, png_inforp info_ptr, + png_uint_32 num_exif, png_bytep eXIf_buf) +{ + int i; + + png_debug1(1, "in %s storage function", "eXIf"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (info_ptr->exif) + { + png_free(png_ptr, info_ptr->exif); + info_ptr->exif = NULL; + } + + info_ptr->num_exif = num_exif; + + info_ptr->exif = png_voidcast(png_bytep, png_malloc_warn(png_ptr, + info_ptr->num_exif)); + + if (info_ptr->exif == NULL) + { + png_warning(png_ptr, "Insufficient memory for eXIf chunk data"); + return; + } + + info_ptr->free_me |= PNG_FREE_EXIF; + + for (i = 0; i < (int) info_ptr->num_exif; i++) + info_ptr->exif[i] = eXIf_buf[i]; + + info_ptr->valid |= PNG_INFO_eXIf; +} +#endif /* eXIf */ + +#ifdef PNG_gAMA_SUPPORTED +void PNGFAPI +png_set_gAMA_fixed(png_const_structrp png_ptr, png_inforp info_ptr, + png_fixed_point file_gamma) +{ + png_debug1(1, "in %s storage function", "gAMA"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_colorspace_set_gamma(png_ptr, &info_ptr->colorspace, file_gamma); + png_colorspace_sync_info(png_ptr, info_ptr); +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_gAMA(png_const_structrp png_ptr, png_inforp info_ptr, double file_gamma) +{ + png_set_gAMA_fixed(png_ptr, info_ptr, png_fixed(png_ptr, file_gamma, + "png_set_gAMA")); +} +# endif +#endif + +#ifdef PNG_hIST_SUPPORTED +void PNGAPI +png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_uint_16p hist) +{ + int i; + + png_debug1(1, "in %s storage function", "hIST"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (info_ptr->num_palette == 0 || info_ptr->num_palette + > PNG_MAX_PALETTE_LENGTH) + { + png_warning(png_ptr, + "Invalid palette size, hIST allocation skipped"); + + return; + } + + png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0); + + /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in + * version 1.2.1 + */ + info_ptr->hist = png_voidcast(png_uint_16p, png_malloc_warn(png_ptr, + PNG_MAX_PALETTE_LENGTH * (sizeof (png_uint_16)))); + + if (info_ptr->hist == NULL) + { + png_warning(png_ptr, "Insufficient memory for hIST chunk data"); + + return; + } + + info_ptr->free_me |= PNG_FREE_HIST; + + for (i = 0; i < info_ptr->num_palette; i++) + info_ptr->hist[i] = hist[i]; + + info_ptr->valid |= PNG_INFO_hIST; +} +#endif + +void PNGAPI +png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_type, int compression_type, + int filter_type) +{ + png_debug1(1, "in %s storage function", "IHDR"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->width = width; + info_ptr->height = height; + info_ptr->bit_depth = (png_byte)bit_depth; + info_ptr->color_type = (png_byte)color_type; + info_ptr->compression_type = (png_byte)compression_type; + info_ptr->filter_type = (png_byte)filter_type; + info_ptr->interlace_type = (png_byte)interlace_type; + + png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height, + info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type, + info_ptr->compression_type, info_ptr->filter_type); + + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + info_ptr->channels = 1; + + else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + info_ptr->channels = 3; + + else + info_ptr->channels = 1; + + if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) + info_ptr->channels++; + + info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth); + + info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width); + +#ifdef PNG_APNG_SUPPORTED + /* for non-animated png. this may be overwritten from an acTL chunk later */ + info_ptr->num_frames = 1; +#endif +} + +#ifdef PNG_oFFs_SUPPORTED +void PNGAPI +png_set_oFFs(png_const_structrp png_ptr, png_inforp info_ptr, + png_int_32 offset_x, png_int_32 offset_y, int unit_type) +{ + png_debug1(1, "in %s storage function", "oFFs"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->x_offset = offset_x; + info_ptr->y_offset = offset_y; + info_ptr->offset_unit_type = (png_byte)unit_type; + info_ptr->valid |= PNG_INFO_oFFs; +} +#endif + +#ifdef PNG_pCAL_SUPPORTED +void PNGAPI +png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type, + int nparams, png_const_charp units, png_charpp params) +{ + size_t length; + int i; + + png_debug1(1, "in %s storage function", "pCAL"); + + if (png_ptr == NULL || info_ptr == NULL || purpose == NULL || units == NULL + || (nparams > 0 && params == NULL)) + return; + + length = strlen(purpose) + 1; + png_debug1(3, "allocating purpose for info (%lu bytes)", + (unsigned long)length); + + /* TODO: validate format of calibration name and unit name */ + + /* Check that the type matches the specification. */ + if (type < 0 || type > 3) + { + png_chunk_report(png_ptr, "Invalid pCAL equation type", + PNG_CHUNK_WRITE_ERROR); + return; + } + + if (nparams < 0 || nparams > 255) + { + png_chunk_report(png_ptr, "Invalid pCAL parameter count", + PNG_CHUNK_WRITE_ERROR); + return; + } + + /* Validate params[nparams] */ + for (i=0; i<nparams; ++i) + { + if (params[i] == NULL || + !png_check_fp_string(params[i], strlen(params[i]))) + { + png_chunk_report(png_ptr, "Invalid format for pCAL parameter", + PNG_CHUNK_WRITE_ERROR); + return; + } + } + + info_ptr->pcal_purpose = png_voidcast(png_charp, + png_malloc_warn(png_ptr, length)); + + if (info_ptr->pcal_purpose == NULL) + { + png_chunk_report(png_ptr, "Insufficient memory for pCAL purpose", + PNG_CHUNK_WRITE_ERROR); + return; + } + + memcpy(info_ptr->pcal_purpose, purpose, length); + + png_debug(3, "storing X0, X1, type, and nparams in info"); + info_ptr->pcal_X0 = X0; + info_ptr->pcal_X1 = X1; + info_ptr->pcal_type = (png_byte)type; + info_ptr->pcal_nparams = (png_byte)nparams; + + length = strlen(units) + 1; + png_debug1(3, "allocating units for info (%lu bytes)", + (unsigned long)length); + + info_ptr->pcal_units = png_voidcast(png_charp, + png_malloc_warn(png_ptr, length)); + + if (info_ptr->pcal_units == NULL) + { + png_warning(png_ptr, "Insufficient memory for pCAL units"); + + return; + } + + memcpy(info_ptr->pcal_units, units, length); + + info_ptr->pcal_params = png_voidcast(png_charpp, png_malloc_warn(png_ptr, + (size_t)(((unsigned int)nparams + 1) * (sizeof (png_charp))))); + + if (info_ptr->pcal_params == NULL) + { + png_warning(png_ptr, "Insufficient memory for pCAL params"); + + return; + } + + memset(info_ptr->pcal_params, 0, ((unsigned int)nparams + 1) * + (sizeof (png_charp))); + + for (i = 0; i < nparams; i++) + { + length = strlen(params[i]) + 1; + png_debug2(3, "allocating parameter %d for info (%lu bytes)", i, + (unsigned long)length); + + info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length); + + if (info_ptr->pcal_params[i] == NULL) + { + png_warning(png_ptr, "Insufficient memory for pCAL parameter"); + + return; + } + + memcpy(info_ptr->pcal_params[i], params[i], length); + } + + info_ptr->valid |= PNG_INFO_pCAL; + info_ptr->free_me |= PNG_FREE_PCAL; +} +#endif + +#ifdef PNG_sCAL_SUPPORTED +void PNGAPI +png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr, + int unit, png_const_charp swidth, png_const_charp sheight) +{ + size_t lengthw = 0, lengthh = 0; + + png_debug1(1, "in %s storage function", "sCAL"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + /* Double check the unit (should never get here with an invalid + * unit unless this is an API call.) + */ + if (unit != 1 && unit != 2) + png_error(png_ptr, "Invalid sCAL unit"); + + if (swidth == NULL || (lengthw = strlen(swidth)) == 0 || + swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw)) + png_error(png_ptr, "Invalid sCAL width"); + + if (sheight == NULL || (lengthh = strlen(sheight)) == 0 || + sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh)) + png_error(png_ptr, "Invalid sCAL height"); + + info_ptr->scal_unit = (png_byte)unit; + + ++lengthw; + + png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw); + + info_ptr->scal_s_width = png_voidcast(png_charp, + png_malloc_warn(png_ptr, lengthw)); + + if (info_ptr->scal_s_width == NULL) + { + png_warning(png_ptr, "Memory allocation failed while processing sCAL"); + + return; + } + + memcpy(info_ptr->scal_s_width, swidth, lengthw); + + ++lengthh; + + png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh); + + info_ptr->scal_s_height = png_voidcast(png_charp, + png_malloc_warn(png_ptr, lengthh)); + + if (info_ptr->scal_s_height == NULL) + { + png_free (png_ptr, info_ptr->scal_s_width); + info_ptr->scal_s_width = NULL; + + png_warning(png_ptr, "Memory allocation failed while processing sCAL"); + + return; + } + + memcpy(info_ptr->scal_s_height, sheight, lengthh); + + info_ptr->valid |= PNG_INFO_sCAL; + info_ptr->free_me |= PNG_FREE_SCAL; +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit, + double width, double height) +{ + png_debug1(1, "in %s storage function", "sCAL"); + + /* Check the arguments. */ + if (width <= 0) + png_warning(png_ptr, "Invalid sCAL width ignored"); + + else if (height <= 0) + png_warning(png_ptr, "Invalid sCAL height ignored"); + + else + { + /* Convert 'width' and 'height' to ASCII. */ + char swidth[PNG_sCAL_MAX_DIGITS+1]; + char sheight[PNG_sCAL_MAX_DIGITS+1]; + + png_ascii_from_fp(png_ptr, swidth, (sizeof swidth), width, + PNG_sCAL_PRECISION); + png_ascii_from_fp(png_ptr, sheight, (sizeof sheight), height, + PNG_sCAL_PRECISION); + + png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight); + } +} +# endif + +# ifdef PNG_FIXED_POINT_SUPPORTED +void PNGAPI +png_set_sCAL_fixed(png_const_structrp png_ptr, png_inforp info_ptr, int unit, + png_fixed_point width, png_fixed_point height) +{ + png_debug1(1, "in %s storage function", "sCAL"); + + /* Check the arguments. */ + if (width <= 0) + png_warning(png_ptr, "Invalid sCAL width ignored"); + + else if (height <= 0) + png_warning(png_ptr, "Invalid sCAL height ignored"); + + else + { + /* Convert 'width' and 'height' to ASCII. */ + char swidth[PNG_sCAL_MAX_DIGITS+1]; + char sheight[PNG_sCAL_MAX_DIGITS+1]; + + png_ascii_from_fixed(png_ptr, swidth, (sizeof swidth), width); + png_ascii_from_fixed(png_ptr, sheight, (sizeof sheight), height); + + png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight); + } +} +# endif +#endif + +#ifdef PNG_pHYs_SUPPORTED +void PNGAPI +png_set_pHYs(png_const_structrp png_ptr, png_inforp info_ptr, + png_uint_32 res_x, png_uint_32 res_y, int unit_type) +{ + png_debug1(1, "in %s storage function", "pHYs"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->x_pixels_per_unit = res_x; + info_ptr->y_pixels_per_unit = res_y; + info_ptr->phys_unit_type = (png_byte)unit_type; + info_ptr->valid |= PNG_INFO_pHYs; +} +#endif + +void PNGAPI +png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr, + png_const_colorp palette, int num_palette) +{ + + png_uint_32 max_palette_length; + + png_debug1(1, "in %s storage function", "PLTE"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + max_palette_length = (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ? + (1 << info_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH; + + if (num_palette < 0 || num_palette > (int) max_palette_length) + { + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + png_error(png_ptr, "Invalid palette length"); + + else + { + png_warning(png_ptr, "Invalid palette length"); + + return; + } + } + + if ((num_palette > 0 && palette == NULL) || + (num_palette == 0 +# ifdef PNG_MNG_FEATURES_SUPPORTED + && (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0 +# endif + )) + { + png_error(png_ptr, "Invalid palette"); + } + + /* It may not actually be necessary to set png_ptr->palette here; + * we do it for backward compatibility with the way the png_handle_tRNS + * function used to do the allocation. + * + * 1.6.0: the above statement appears to be incorrect; something has to set + * the palette inside png_struct on read. + */ + png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0); + + /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead + * of num_palette entries, in case of an invalid PNG file or incorrect + * call to png_set_PLTE() with too-large sample values. + */ + png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr, + PNG_MAX_PALETTE_LENGTH * (sizeof (png_color)))); + + if (num_palette > 0) + memcpy(png_ptr->palette, palette, (unsigned int)num_palette * + (sizeof (png_color))); + info_ptr->palette = png_ptr->palette; + info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette; + + info_ptr->free_me |= PNG_FREE_PLTE; + + info_ptr->valid |= PNG_INFO_PLTE; +} + +#ifdef PNG_sBIT_SUPPORTED +void PNGAPI +png_set_sBIT(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_color_8p sig_bit) +{ + png_debug1(1, "in %s storage function", "sBIT"); + + if (png_ptr == NULL || info_ptr == NULL || sig_bit == NULL) + return; + + info_ptr->sig_bit = *sig_bit; + info_ptr->valid |= PNG_INFO_sBIT; +} +#endif + +#ifdef PNG_sRGB_SUPPORTED +void PNGAPI +png_set_sRGB(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent) +{ + png_debug1(1, "in %s storage function", "sRGB"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + (void)png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent); + png_colorspace_sync_info(png_ptr, info_ptr); +} + +void PNGAPI +png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr, + int srgb_intent) +{ + png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, + srgb_intent) != 0) + { + /* This causes the gAMA and cHRM to be written too */ + info_ptr->colorspace.flags |= + PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM; + } + + png_colorspace_sync_info(png_ptr, info_ptr); +} +#endif /* sRGB */ + + +#ifdef PNG_iCCP_SUPPORTED +void PNGAPI +png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_charp name, int compression_type, + png_const_bytep profile, png_uint_32 proflen) +{ + png_charp new_iccp_name; + png_bytep new_iccp_profile; + size_t length; + + png_debug1(1, "in %s storage function", "iCCP"); + + if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL) + return; + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + png_app_error(png_ptr, "Invalid iCCP compression method"); + + /* Set the colorspace first because this validates the profile; do not + * override previously set app cHRM or gAMA here (because likely as not the + * application knows better than libpng what the correct values are.) Pass + * the info_ptr color_type field to png_colorspace_set_ICC because in the + * write case it has not yet been stored in png_ptr. + */ + { + int result = png_colorspace_set_ICC(png_ptr, &info_ptr->colorspace, name, + proflen, profile, info_ptr->color_type); + + png_colorspace_sync_info(png_ptr, info_ptr); + + /* Don't do any of the copying if the profile was bad, or inconsistent. */ + if (result == 0) + return; + + /* But do write the gAMA and cHRM chunks from the profile. */ + info_ptr->colorspace.flags |= + PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM; + } + + length = strlen(name)+1; + new_iccp_name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length)); + + if (new_iccp_name == NULL) + { + png_benign_error(png_ptr, "Insufficient memory to process iCCP chunk"); + + return; + } + + memcpy(new_iccp_name, name, length); + new_iccp_profile = png_voidcast(png_bytep, + png_malloc_warn(png_ptr, proflen)); + + if (new_iccp_profile == NULL) + { + png_free(png_ptr, new_iccp_name); + png_benign_error(png_ptr, + "Insufficient memory to process iCCP profile"); + + return; + } + + memcpy(new_iccp_profile, profile, proflen); + + png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0); + + info_ptr->iccp_proflen = proflen; + info_ptr->iccp_name = new_iccp_name; + info_ptr->iccp_profile = new_iccp_profile; + info_ptr->free_me |= PNG_FREE_ICCP; + info_ptr->valid |= PNG_INFO_iCCP; +} +#endif + +#ifdef PNG_TEXT_SUPPORTED +void PNGAPI +png_set_text(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_textp text_ptr, int num_text) +{ + int ret; + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text); + + if (ret != 0) + png_error(png_ptr, "Insufficient memory to store text"); +} + +int /* PRIVATE */ +png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_textp text_ptr, int num_text) +{ + int i; + + png_debug1(1, "in %lx storage function", png_ptr == NULL ? 0xabadca11U : + (unsigned long)png_ptr->chunk_name); + + if (png_ptr == NULL || info_ptr == NULL || num_text <= 0 || text_ptr == NULL) + return(0); + + /* Make sure we have enough space in the "text" array in info_struct + * to hold all of the incoming text_ptr objects. This compare can't overflow + * because max_text >= num_text (anyway, subtract of two positive integers + * can't overflow in any case.) + */ + if (num_text > info_ptr->max_text - info_ptr->num_text) + { + int old_num_text = info_ptr->num_text; + int max_text; + png_textp new_text = NULL; + + /* Calculate an appropriate max_text, checking for overflow. */ + max_text = old_num_text; + if (num_text <= INT_MAX - max_text) + { + max_text += num_text; + + /* Round up to a multiple of 8 */ + if (max_text < INT_MAX-8) + max_text = (max_text + 8) & ~0x7; + + else + max_text = INT_MAX; + + /* Now allocate a new array and copy the old members in; this does all + * the overflow checks. + */ + new_text = png_voidcast(png_textp,png_realloc_array(png_ptr, + info_ptr->text, old_num_text, max_text-old_num_text, + sizeof *new_text)); + } + + if (new_text == NULL) + { + png_chunk_report(png_ptr, "too many text chunks", + PNG_CHUNK_WRITE_ERROR); + + return 1; + } + + png_free(png_ptr, info_ptr->text); + + info_ptr->text = new_text; + info_ptr->free_me |= PNG_FREE_TEXT; + info_ptr->max_text = max_text; + /* num_text is adjusted below as the entries are copied in */ + + png_debug1(3, "allocated %d entries for info_ptr->text", max_text); + } + + for (i = 0; i < num_text; i++) + { + size_t text_length, key_len; + size_t lang_len, lang_key_len; + png_textp textp = &(info_ptr->text[info_ptr->num_text]); + + if (text_ptr[i].key == NULL) + continue; + + if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE || + text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST) + { + png_chunk_report(png_ptr, "text compression mode is out of range", + PNG_CHUNK_WRITE_ERROR); + continue; + } + + key_len = strlen(text_ptr[i].key); + + if (text_ptr[i].compression <= 0) + { + lang_len = 0; + lang_key_len = 0; + } + + else +# ifdef PNG_iTXt_SUPPORTED + { + /* Set iTXt data */ + + if (text_ptr[i].lang != NULL) + lang_len = strlen(text_ptr[i].lang); + + else + lang_len = 0; + + if (text_ptr[i].lang_key != NULL) + lang_key_len = strlen(text_ptr[i].lang_key); + + else + lang_key_len = 0; + } +# else /* iTXt */ + { + png_chunk_report(png_ptr, "iTXt chunk not supported", + PNG_CHUNK_WRITE_ERROR); + continue; + } +# endif + + if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0') + { + text_length = 0; +# ifdef PNG_iTXt_SUPPORTED + if (text_ptr[i].compression > 0) + textp->compression = PNG_ITXT_COMPRESSION_NONE; + + else +# endif + textp->compression = PNG_TEXT_COMPRESSION_NONE; + } + + else + { + text_length = strlen(text_ptr[i].text); + textp->compression = text_ptr[i].compression; + } + + textp->key = png_voidcast(png_charp,png_malloc_base(png_ptr, + key_len + text_length + lang_len + lang_key_len + 4)); + + if (textp->key == NULL) + { + png_chunk_report(png_ptr, "text chunk: out of memory", + PNG_CHUNK_WRITE_ERROR); + + return 1; + } + + png_debug2(2, "Allocated %lu bytes at %p in png_set_text", + (unsigned long)(png_uint_32) + (key_len + lang_len + lang_key_len + text_length + 4), + textp->key); + + memcpy(textp->key, text_ptr[i].key, key_len); + *(textp->key + key_len) = '\0'; + + if (text_ptr[i].compression > 0) + { + textp->lang = textp->key + key_len + 1; + memcpy(textp->lang, text_ptr[i].lang, lang_len); + *(textp->lang + lang_len) = '\0'; + textp->lang_key = textp->lang + lang_len + 1; + memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len); + *(textp->lang_key + lang_key_len) = '\0'; + textp->text = textp->lang_key + lang_key_len + 1; + } + + else + { + textp->lang=NULL; + textp->lang_key=NULL; + textp->text = textp->key + key_len + 1; + } + + if (text_length != 0) + memcpy(textp->text, text_ptr[i].text, text_length); + + *(textp->text + text_length) = '\0'; + +# ifdef PNG_iTXt_SUPPORTED + if (textp->compression > 0) + { + textp->text_length = 0; + textp->itxt_length = text_length; + } + + else +# endif + { + textp->text_length = text_length; + textp->itxt_length = 0; + } + + info_ptr->num_text++; + png_debug1(3, "transferred text chunk %d", info_ptr->num_text); + } + + return(0); +} +#endif + +#ifdef PNG_tIME_SUPPORTED +void PNGAPI +png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_timep mod_time) +{ + png_debug1(1, "in %s storage function", "tIME"); + + if (png_ptr == NULL || info_ptr == NULL || mod_time == NULL || + (png_ptr->mode & PNG_WROTE_tIME) != 0) + return; + + if (mod_time->month == 0 || mod_time->month > 12 || + mod_time->day == 0 || mod_time->day > 31 || + mod_time->hour > 23 || mod_time->minute > 59 || + mod_time->second > 60) + { + png_warning(png_ptr, "Ignoring invalid time value"); + + return; + } + + info_ptr->mod_time = *mod_time; + info_ptr->valid |= PNG_INFO_tIME; +} +#endif + +#ifdef PNG_tRNS_SUPPORTED +void PNGAPI +png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr, + png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color) +{ + png_debug1(1, "in %s storage function", "tRNS"); + + if (png_ptr == NULL || info_ptr == NULL) + + return; + + if (trans_alpha != NULL) + { + /* It may not actually be necessary to set png_ptr->trans_alpha here; + * we do it for backward compatibility with the way the png_handle_tRNS + * function used to do the allocation. + * + * 1.6.0: The above statement is incorrect; png_handle_tRNS effectively + * relies on png_set_tRNS storing the information in png_struct + * (otherwise it won't be there for the code in pngrtran.c). + */ + + png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0); + + if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH) + { + /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */ + info_ptr->trans_alpha = png_voidcast(png_bytep, + png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH)); + memcpy(info_ptr->trans_alpha, trans_alpha, (size_t)num_trans); + } + png_ptr->trans_alpha = info_ptr->trans_alpha; + } + + if (trans_color != NULL) + { +#ifdef PNG_WARNINGS_SUPPORTED + if (info_ptr->bit_depth < 16) + { + int sample_max = (1 << info_ptr->bit_depth) - 1; + + if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY && + trans_color->gray > sample_max) || + (info_ptr->color_type == PNG_COLOR_TYPE_RGB && + (trans_color->red > sample_max || + trans_color->green > sample_max || + trans_color->blue > sample_max))) + png_warning(png_ptr, + "tRNS chunk has out-of-range samples for bit_depth"); + } +#endif + + info_ptr->trans_color = *trans_color; + + if (num_trans == 0) + num_trans = 1; + } + + info_ptr->num_trans = (png_uint_16)num_trans; + + if (num_trans != 0) + { + info_ptr->valid |= PNG_INFO_tRNS; + info_ptr->free_me |= PNG_FREE_TRNS; + } +} +#endif + +#ifdef PNG_sPLT_SUPPORTED +void PNGAPI +png_set_sPLT(png_const_structrp png_ptr, + png_inforp info_ptr, png_const_sPLT_tp entries, int nentries) +/* + * entries - array of png_sPLT_t structures + * to be added to the list of palettes + * in the info structure. + * + * nentries - number of palette structures to be + * added. + */ +{ + png_sPLT_tp np; + + if (png_ptr == NULL || info_ptr == NULL || nentries <= 0 || entries == NULL) + return; + + /* Use the internal realloc function, which checks for all the possible + * overflows. Notice that the parameters are (int) and (size_t) + */ + np = png_voidcast(png_sPLT_tp,png_realloc_array(png_ptr, + info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries, + sizeof *np)); + + if (np == NULL) + { + /* Out of memory or too many chunks */ + png_chunk_report(png_ptr, "too many sPLT chunks", PNG_CHUNK_WRITE_ERROR); + + return; + } + + png_free(png_ptr, info_ptr->splt_palettes); + info_ptr->splt_palettes = np; + info_ptr->free_me |= PNG_FREE_SPLT; + + np += info_ptr->splt_palettes_num; + + do + { + size_t length; + + /* Skip invalid input entries */ + if (entries->name == NULL || entries->entries == NULL) + { + /* png_handle_sPLT doesn't do this, so this is an app error */ + png_app_error(png_ptr, "png_set_sPLT: invalid sPLT"); + /* Just skip the invalid entry */ + continue; + } + + np->depth = entries->depth; + + /* In the event of out-of-memory just return - there's no point keeping + * on trying to add sPLT chunks. + */ + length = strlen(entries->name) + 1; + np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length)); + + if (np->name == NULL) + break; + + memcpy(np->name, entries->name, length); + + /* IMPORTANT: we have memory now that won't get freed if something else + * goes wrong; this code must free it. png_malloc_array produces no + * warnings; use a png_chunk_report (below) if there is an error. + */ + np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr, + entries->nentries, sizeof (png_sPLT_entry))); + + if (np->entries == NULL) + { + png_free(png_ptr, np->name); + np->name = NULL; + break; + } + + np->nentries = entries->nentries; + /* This multiply can't overflow because png_malloc_array has already + * checked it when doing the allocation. + */ + memcpy(np->entries, entries->entries, + (unsigned int)entries->nentries * sizeof (png_sPLT_entry)); + + /* Note that 'continue' skips the advance of the out pointer and out + * count, so an invalid entry is not added. + */ + info_ptr->valid |= PNG_INFO_sPLT; + ++(info_ptr->splt_palettes_num); + ++np; + ++entries; + } + while (--nentries); + + if (nentries > 0) + png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR); +} +#endif /* sPLT */ + +#ifdef PNG_APNG_SUPPORTED +png_uint_32 PNGAPI +png_set_acTL(png_structp png_ptr, png_infop info_ptr, + png_uint_32 num_frames, png_uint_32 num_plays) +{ + png_debug1(1, "in %s storage function", "acTL"); + + if (png_ptr == NULL || info_ptr == NULL) + { + png_warning(png_ptr, + "Call to png_set_acTL() with NULL png_ptr " + "or info_ptr ignored"); + return (0); + } + if (num_frames == 0) + { + png_warning(png_ptr, + "Ignoring attempt to set acTL with num_frames zero"); + return (0); + } + if (num_frames > PNG_UINT_31_MAX) + { + png_warning(png_ptr, + "Ignoring attempt to set acTL with num_frames > 2^31-1"); + return (0); + } + if (num_plays > PNG_UINT_31_MAX) + { + png_warning(png_ptr, + "Ignoring attempt to set acTL with num_plays > 2^31-1"); + return (0); + } + + info_ptr->num_frames = num_frames; + info_ptr->num_plays = num_plays; + + info_ptr->valid |= PNG_INFO_acTL; + + return (1); +} + +/* delay_num and delay_den can hold any 16-bit values including zero */ +png_uint_32 PNGAPI +png_set_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr, + png_uint_32 width, png_uint_32 height, + png_uint_32 x_offset, png_uint_32 y_offset, + png_uint_16 delay_num, png_uint_16 delay_den, + png_byte dispose_op, png_byte blend_op) +{ + png_debug1(1, "in %s storage function", "fcTL"); + + if (png_ptr == NULL || info_ptr == NULL) + { + png_warning(png_ptr, + "Call to png_set_fcTL() with NULL png_ptr or info_ptr " + "ignored"); + return (0); + } + + png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset, + delay_num, delay_den, dispose_op, blend_op); + + if (blend_op == PNG_BLEND_OP_OVER) + { + if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0 && + png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) == 0) + { + png_warning(png_ptr, "PNG_BLEND_OP_OVER is meaningless " + "and wasteful for opaque images, ignored"); + blend_op = PNG_BLEND_OP_SOURCE; + } + } + + info_ptr->next_frame_width = width; + info_ptr->next_frame_height = height; + info_ptr->next_frame_x_offset = x_offset; + info_ptr->next_frame_y_offset = y_offset; + info_ptr->next_frame_delay_num = delay_num; + info_ptr->next_frame_delay_den = delay_den; + info_ptr->next_frame_dispose_op = dispose_op; + info_ptr->next_frame_blend_op = blend_op; + + info_ptr->valid |= PNG_INFO_fcTL; + + return (1); +} + +void /* PRIVATE */ +png_ensure_fcTL_is_valid(png_structp png_ptr, + png_uint_32 width, png_uint_32 height, + png_uint_32 x_offset, png_uint_32 y_offset, + png_uint_16 delay_num, png_uint_16 delay_den, + png_byte dispose_op, png_byte blend_op) +{ + if (width == 0 || width > PNG_UINT_31_MAX) + png_error(png_ptr, "invalid width in fcTL (0 or > 2^31-1)"); + if (height == 0 || height > PNG_UINT_31_MAX) + png_error(png_ptr, "invalid height in fcTL (0 or > 2^31-1)"); + if (x_offset > PNG_UINT_31_MAX) + png_error(png_ptr, "invalid x_offset in fcTL (> 2^31-1)"); + if (y_offset > PNG_UINT_31_MAX) + png_error(png_ptr, "invalid y_offset in fcTL (> 2^31-1)"); + if (width + x_offset > png_ptr->first_frame_width || + height + y_offset > png_ptr->first_frame_height) + png_error(png_ptr, "dimensions of a frame are greater than " + "the ones in IHDR"); + + if (dispose_op != PNG_DISPOSE_OP_NONE && + dispose_op != PNG_DISPOSE_OP_BACKGROUND && + dispose_op != PNG_DISPOSE_OP_PREVIOUS) + png_error(png_ptr, "invalid dispose_op in fcTL"); + + if (blend_op != PNG_BLEND_OP_SOURCE && + blend_op != PNG_BLEND_OP_OVER) + png_error(png_ptr, "invalid blend_op in fcTL"); + + PNG_UNUSED(delay_num) + PNG_UNUSED(delay_den) +} + +png_uint_32 PNGAPI +png_set_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr, + png_byte is_hidden) +{ + png_debug(1, "in png_first_frame_is_hidden()"); + + if (png_ptr == NULL) + return 0; + + if (is_hidden != 0) + png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN; + else + png_ptr->apng_flags &= ~PNG_FIRST_FRAME_HIDDEN; + + PNG_UNUSED(info_ptr) + + return 1; +} +#endif /* APNG */ + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +static png_byte +check_location(png_const_structrp png_ptr, int location) +{ + location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT); + + /* New in 1.6.0; copy the location and check it. This is an API + * change; previously the app had to use the + * png_set_unknown_chunk_location API below for each chunk. + */ + if (location == 0 && (png_ptr->mode & PNG_IS_READ_STRUCT) == 0) + { + /* Write struct, so unknown chunks come from the app */ + png_app_warning(png_ptr, + "png_set_unknown_chunks now expects a valid location"); + /* Use the old behavior */ + location = (png_byte)(png_ptr->mode & + (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)); + } + + /* This need not be an internal error - if the app calls + * png_set_unknown_chunks on a read pointer it must get the location right. + */ + if (location == 0) + png_error(png_ptr, "invalid location in png_set_unknown_chunks"); + + /* Now reduce the location to the top-most set bit by removing each least + * significant bit in turn. + */ + while (location != (location & -location)) + location &= ~(location & -location); + + /* The cast is safe because 'location' is a bit mask and only the low four + * bits are significant. + */ + return (png_byte)location; +} + +void PNGAPI +png_set_unknown_chunks(png_const_structrp png_ptr, + png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns) +{ + png_unknown_chunkp np; + + if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0 || + unknowns == NULL) + return; + + /* Check for the failure cases where support has been disabled at compile + * time. This code is hardly ever compiled - it's here because + * STORE_UNKNOWN_CHUNKS is set by both read and write code (compiling in this + * code) but may be meaningless if the read or write handling of unknown + * chunks is not compiled in. + */ +# if !defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \ + defined(PNG_READ_SUPPORTED) + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) + { + png_app_error(png_ptr, "no unknown chunk support on read"); + + return; + } +# endif +# if !defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \ + defined(PNG_WRITE_SUPPORTED) + if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0) + { + png_app_error(png_ptr, "no unknown chunk support on write"); + + return; + } +# endif + + /* Prior to 1.6.0 this code used png_malloc_warn; however, this meant that + * unknown critical chunks could be lost with just a warning resulting in + * undefined behavior. Now png_chunk_report is used to provide behavior + * appropriate to read or write. + */ + np = png_voidcast(png_unknown_chunkp, png_realloc_array(png_ptr, + info_ptr->unknown_chunks, info_ptr->unknown_chunks_num, num_unknowns, + sizeof *np)); + + if (np == NULL) + { + png_chunk_report(png_ptr, "too many unknown chunks", + PNG_CHUNK_WRITE_ERROR); + + return; + } + + png_free(png_ptr, info_ptr->unknown_chunks); + info_ptr->unknown_chunks = np; /* safe because it is initialized */ + info_ptr->free_me |= PNG_FREE_UNKN; + + np += info_ptr->unknown_chunks_num; + + /* Increment unknown_chunks_num each time round the loop to protect the + * just-allocated chunk data. + */ + for (; num_unknowns > 0; --num_unknowns, ++unknowns) + { + memcpy(np->name, unknowns->name, (sizeof np->name)); + np->name[(sizeof np->name)-1] = '\0'; + np->location = check_location(png_ptr, unknowns->location); + + if (unknowns->size == 0) + { + np->data = NULL; + np->size = 0; + } + + else + { + np->data = png_voidcast(png_bytep, + png_malloc_base(png_ptr, unknowns->size)); + + if (np->data == NULL) + { + png_chunk_report(png_ptr, "unknown chunk: out of memory", + PNG_CHUNK_WRITE_ERROR); + /* But just skip storing the unknown chunk */ + continue; + } + + memcpy(np->data, unknowns->data, unknowns->size); + np->size = unknowns->size; + } + + /* These increments are skipped on out-of-memory for the data - the + * unknown chunk entry gets overwritten if the png_chunk_report returns. + * This is correct in the read case (the chunk is just dropped.) + */ + ++np; + ++(info_ptr->unknown_chunks_num); + } +} + +void PNGAPI +png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr, + int chunk, int location) +{ + /* This API is pretty pointless in 1.6.0 because the location can be set + * before the call to png_set_unknown_chunks. + * + * TODO: add a png_app_warning in 1.7 + */ + if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 && + chunk < info_ptr->unknown_chunks_num) + { + if ((location & (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)) == 0) + { + png_app_error(png_ptr, "invalid unknown chunk location"); + /* Fake out the pre 1.6.0 behavior: */ + if (((unsigned int)location & PNG_HAVE_IDAT) != 0) /* undocumented! */ + location = PNG_AFTER_IDAT; + + else + location = PNG_HAVE_IHDR; /* also undocumented */ + } + + info_ptr->unknown_chunks[chunk].location = + check_location(png_ptr, location); + } +} +#endif /* STORE_UNKNOWN_CHUNKS */ + +#ifdef PNG_MNG_FEATURES_SUPPORTED +png_uint_32 PNGAPI +png_permit_mng_features (png_structrp png_ptr, png_uint_32 mng_features) +{ + png_debug(1, "in png_permit_mng_features"); + + if (png_ptr == NULL) + return 0; + + png_ptr->mng_features_permitted = mng_features & PNG_ALL_MNG_FEATURES; + + return png_ptr->mng_features_permitted; +} +#endif + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +static unsigned int +add_one_chunk(png_bytep list, unsigned int count, png_const_bytep add, int keep) +{ + unsigned int i; + + /* Utility function: update the 'keep' state of a chunk if it is already in + * the list, otherwise add it to the list. + */ + for (i=0; i<count; ++i, list += 5) + { + if (memcmp(list, add, 4) == 0) + { + list[4] = (png_byte)keep; + + return count; + } + } + + if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT) + { + ++count; + memcpy(list, add, 4); + list[4] = (png_byte)keep; + } + + return count; +} + +void PNGAPI +png_set_keep_unknown_chunks(png_structrp png_ptr, int keep, + png_const_bytep chunk_list, int num_chunks_in) +{ + png_bytep new_list; + unsigned int num_chunks, old_num_chunks; + + if (png_ptr == NULL) + return; + + if (keep < 0 || keep >= PNG_HANDLE_CHUNK_LAST) + { + png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep"); + + return; + } + + if (num_chunks_in <= 0) + { + png_ptr->unknown_default = keep; + + /* '0' means just set the flags, so stop here */ + if (num_chunks_in == 0) + return; + } + + if (num_chunks_in < 0) + { + /* Ignore all unknown chunks and all chunks recognized by + * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND + */ + static const png_byte chunks_to_ignore[] = { + 98, 75, 71, 68, '\0', /* bKGD */ + 99, 72, 82, 77, '\0', /* cHRM */ + 101, 88, 73, 102, '\0', /* eXIf */ + 103, 65, 77, 65, '\0', /* gAMA */ + 104, 73, 83, 84, '\0', /* hIST */ + 105, 67, 67, 80, '\0', /* iCCP */ + 105, 84, 88, 116, '\0', /* iTXt */ + 111, 70, 70, 115, '\0', /* oFFs */ + 112, 67, 65, 76, '\0', /* pCAL */ + 112, 72, 89, 115, '\0', /* pHYs */ + 115, 66, 73, 84, '\0', /* sBIT */ + 115, 67, 65, 76, '\0', /* sCAL */ + 115, 80, 76, 84, '\0', /* sPLT */ + 115, 84, 69, 82, '\0', /* sTER */ + 115, 82, 71, 66, '\0', /* sRGB */ + 116, 69, 88, 116, '\0', /* tEXt */ + 116, 73, 77, 69, '\0', /* tIME */ + 122, 84, 88, 116, '\0' /* zTXt */ + }; + + chunk_list = chunks_to_ignore; + num_chunks = (unsigned int)/*SAFE*/(sizeof chunks_to_ignore)/5U; + } + + else /* num_chunks_in > 0 */ + { + if (chunk_list == NULL) + { + /* Prior to 1.6.0 this was silently ignored, now it is an app_error + * which can be switched off. + */ + png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list"); + + return; + } + + num_chunks = (unsigned int)num_chunks_in; + } + + old_num_chunks = png_ptr->num_chunk_list; + if (png_ptr->chunk_list == NULL) + old_num_chunks = 0; + + /* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow. + */ + if (num_chunks + old_num_chunks > UINT_MAX/5) + { + png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks"); + + return; + } + + /* If these chunks are being reset to the default then no more memory is + * required because add_one_chunk above doesn't extend the list if the 'keep' + * parameter is the default. + */ + if (keep != 0) + { + new_list = png_voidcast(png_bytep, png_malloc(png_ptr, + 5 * (num_chunks + old_num_chunks))); + + if (old_num_chunks > 0) + memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks); + } + + else if (old_num_chunks > 0) + new_list = png_ptr->chunk_list; + + else + new_list = NULL; + + /* Add the new chunks together with each one's handling code. If the chunk + * already exists the code is updated, otherwise the chunk is added to the + * end. (In libpng 1.6.0 order no longer matters because this code enforces + * the earlier convention that the last setting is the one that is used.) + */ + if (new_list != NULL) + { + png_const_bytep inlist; + png_bytep outlist; + unsigned int i; + + for (i=0; i<num_chunks; ++i) + { + old_num_chunks = add_one_chunk(new_list, old_num_chunks, + chunk_list+5*i, keep); + } + + /* Now remove any spurious 'default' entries. */ + num_chunks = 0; + for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5) + { + if (inlist[4]) + { + if (outlist != inlist) + memcpy(outlist, inlist, 5); + outlist += 5; + ++num_chunks; + } + } + + /* This means the application has removed all the specialized handling. */ + if (num_chunks == 0) + { + if (png_ptr->chunk_list != new_list) + png_free(png_ptr, new_list); + + new_list = NULL; + } + } + + else + num_chunks = 0; + + png_ptr->num_chunk_list = num_chunks; + + if (png_ptr->chunk_list != new_list) + { + if (png_ptr->chunk_list != NULL) + png_free(png_ptr, png_ptr->chunk_list); + + png_ptr->chunk_list = new_list; + } +} +#endif + +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED +void PNGAPI +png_set_read_user_chunk_fn(png_structrp png_ptr, png_voidp user_chunk_ptr, + png_user_chunk_ptr read_user_chunk_fn) +{ + png_debug(1, "in png_set_read_user_chunk_fn"); + + if (png_ptr == NULL) + return; + + png_ptr->read_user_chunk_fn = read_user_chunk_fn; + png_ptr->user_chunk_ptr = user_chunk_ptr; +} +#endif + +#ifdef PNG_INFO_IMAGE_SUPPORTED +void PNGAPI +png_set_rows(png_const_structrp png_ptr, png_inforp info_ptr, + png_bytepp row_pointers) +{ + png_debug1(1, "in %s storage function", "rows"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (info_ptr->row_pointers != NULL && + (info_ptr->row_pointers != row_pointers)) + png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); + + info_ptr->row_pointers = row_pointers; + + if (row_pointers != NULL) + info_ptr->valid |= PNG_INFO_IDAT; +} +#endif + +void PNGAPI +png_set_compression_buffer_size(png_structrp png_ptr, size_t size) +{ + if (png_ptr == NULL) + return; + + if (size == 0 || size > PNG_UINT_31_MAX) + png_error(png_ptr, "invalid compression buffer size"); + +# ifdef PNG_SEQUENTIAL_READ_SUPPORTED + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) + { + png_ptr->IDAT_read_size = (png_uint_32)size; /* checked above */ + return; + } +# endif + +# ifdef PNG_WRITE_SUPPORTED + if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0) + { + if (png_ptr->zowner != 0) + { + png_warning(png_ptr, + "Compression buffer size cannot be changed because it is in use"); + + return; + } + +#ifndef __COVERITY__ + /* Some compilers complain that this is always false. However, it + * can be true when integer overflow happens. + */ + if (size > ZLIB_IO_MAX) + { + png_warning(png_ptr, + "Compression buffer size limited to system maximum"); + size = ZLIB_IO_MAX; /* must fit */ + } +#endif + + if (size < 6) + { + /* Deflate will potentially go into an infinite loop on a SYNC_FLUSH + * if this is permitted. + */ + png_warning(png_ptr, + "Compression buffer size cannot be reduced below 6"); + + return; + } + + if (png_ptr->zbuffer_size != size) + { + png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list); + png_ptr->zbuffer_size = (uInt)size; + } + } +# endif +} + +void PNGAPI +png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask) +{ + if (png_ptr != NULL && info_ptr != NULL) + info_ptr->valid &= (unsigned int)(~mask); +} + + +#ifdef PNG_SET_USER_LIMITS_SUPPORTED +/* This function was added to libpng 1.2.6 */ +void PNGAPI +png_set_user_limits (png_structrp png_ptr, png_uint_32 user_width_max, + png_uint_32 user_height_max) +{ + /* Images with dimensions larger than these limits will be + * rejected by png_set_IHDR(). To accept any PNG datastream + * regardless of dimensions, set both limits to 0x7fffffff. + */ + if (png_ptr == NULL) + return; + + png_ptr->user_width_max = user_width_max; + png_ptr->user_height_max = user_height_max; +} + +/* This function was added to libpng 1.4.0 */ +void PNGAPI +png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max) +{ + if (png_ptr != NULL) + png_ptr->user_chunk_cache_max = user_chunk_cache_max; +} + +/* This function was added to libpng 1.4.1 */ +void PNGAPI +png_set_chunk_malloc_max (png_structrp png_ptr, + png_alloc_size_t user_chunk_malloc_max) +{ + if (png_ptr != NULL) + png_ptr->user_chunk_malloc_max = user_chunk_malloc_max; +} +#endif /* ?SET_USER_LIMITS */ + + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +void PNGAPI +png_set_benign_errors(png_structrp png_ptr, int allowed) +{ + png_debug(1, "in png_set_benign_errors"); + + /* If allowed is 1, png_benign_error() is treated as a warning. + * + * If allowed is 0, png_benign_error() is treated as an error (which + * is the default behavior if png_set_benign_errors() is not called). + */ + + if (allowed != 0) + png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN | + PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN; + + else + png_ptr->flags &= ~(PNG_FLAG_BENIGN_ERRORS_WARN | + PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN); +} +#endif /* BENIGN_ERRORS */ + +#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Whether to report invalid palette index; added at libng-1.5.10. + * It is possible for an indexed (color-type==3) PNG file to contain + * pixels with invalid (out-of-range) indexes if the PLTE chunk has + * fewer entries than the image's bit-depth would allow. We recover + * from this gracefully by filling any incomplete palette with zeros + * (opaque black). By default, when this occurs libpng will issue + * a benign error. This API can be used to override that behavior. + */ +void PNGAPI +png_set_check_for_invalid_index(png_structrp png_ptr, int allowed) +{ + png_debug(1, "in png_set_check_for_invalid_index"); + + if (allowed > 0) + png_ptr->num_palette_max = 0; + + else + png_ptr->num_palette_max = -1; +} +#endif + +#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) || \ + defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) +/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification, + * and if invalid, correct the keyword rather than discarding the entire + * chunk. The PNG 1.0 specification requires keywords 1-79 characters in + * length, forbids leading or trailing whitespace, multiple internal spaces, + * and the non-break space (0x80) from ISO 8859-1. Returns keyword length. + * + * The 'new_key' buffer must be 80 characters in size (for the keyword plus a + * trailing '\0'). If this routine returns 0 then there was no keyword, or a + * valid one could not be generated, and the caller must png_error. + */ +png_uint_32 /* PRIVATE */ +png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key) +{ +#ifdef PNG_WARNINGS_SUPPORTED + png_const_charp orig_key = key; +#endif + png_uint_32 key_len = 0; + int bad_character = 0; + int space = 1; + + png_debug(1, "in png_check_keyword"); + + if (key == NULL) + { + *new_key = 0; + return 0; + } + + while (*key && key_len < 79) + { + png_byte ch = (png_byte)*key++; + + if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/)) + { + *new_key++ = ch; ++key_len; space = 0; + } + + else if (space == 0) + { + /* A space or an invalid character when one wasn't seen immediately + * before; output just a space. + */ + *new_key++ = 32; ++key_len; space = 1; + + /* If the character was not a space then it is invalid. */ + if (ch != 32) + bad_character = ch; + } + + else if (bad_character == 0) + bad_character = ch; /* just skip it, record the first error */ + } + + if (key_len > 0 && space != 0) /* trailing space */ + { + --key_len; --new_key; + if (bad_character == 0) + bad_character = 32; + } + + /* Terminate the keyword */ + *new_key = 0; + + if (key_len == 0) + return 0; + +#ifdef PNG_WARNINGS_SUPPORTED + /* Try to only output one warning per keyword: */ + if (*key != 0) /* keyword too long */ + png_warning(png_ptr, "keyword truncated"); + + else if (bad_character != 0) + { + PNG_WARNING_PARAMETERS(p) + + png_warning_parameter(p, 1, orig_key); + png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character); + + png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'"); + } +#else /* !WARNINGS */ + PNG_UNUSED(png_ptr) +#endif /* !WARNINGS */ + + return key_len; +} +#endif /* TEXT || pCAL || iCCP || sPLT */ +#endif /* READ || WRITE */ diff --git a/media/libpng/pngstruct.h b/media/libpng/pngstruct.h new file mode 100644 index 0000000000..d45a557541 --- /dev/null +++ b/media/libpng/pngstruct.h @@ -0,0 +1,510 @@ + +/* pngstruct.h - header file for PNG reference library + * + * Copyright (c) 2018-2019 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* The structure that holds the information to read and write PNG files. + * The only people who need to care about what is inside of this are the + * people who will be modifying the library for their own special needs. + * It should NOT be accessed directly by an application. + */ + +#ifndef PNGSTRUCT_H +#define PNGSTRUCT_H +/* zlib.h defines the structure z_stream, an instance of which is included + * in this structure and is required for decompressing the LZ compressed + * data in PNG files. + */ +#ifndef ZLIB_CONST + /* We must ensure that zlib uses 'const' in declarations. */ +# define ZLIB_CONST +#endif +#include "zlib.h" +#ifdef const + /* zlib.h sometimes #defines const to nothing, undo this. */ +# undef const +#endif + +/* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility + * with older builds. + */ +#if ZLIB_VERNUM < 0x1260 +# define PNGZ_MSG_CAST(s) png_constcast(char*,s) +# define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b) +#else +# define PNGZ_MSG_CAST(s) (s) +# define PNGZ_INPUT_CAST(b) (b) +#endif + +/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib + * can handle at once. This type need be no larger than 16 bits (so maximum of + * 65535), this define allows us to discover how big it is, but limited by the + * maximum for size_t. The value can be overridden in a library build + * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably + * lower value (e.g. 255 works). A lower value may help memory usage (slightly) + * and may even improve performance on some systems (and degrade it on others.) + */ +#ifndef ZLIB_IO_MAX +# define ZLIB_IO_MAX ((uInt)-1) +#endif + +#ifdef PNG_WRITE_SUPPORTED +/* The type of a compression buffer list used by the write code. */ +typedef struct png_compression_buffer +{ + struct png_compression_buffer *next; + png_byte output[1]; /* actually zbuf_size */ +} png_compression_buffer, *png_compression_bufferp; + +#define PNG_COMPRESSION_BUFFER_SIZE(pp)\ + (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size) +#endif + +/* Colorspace support; structures used in png_struct, png_info and in internal + * functions to hold and communicate information about the color space. + * + * PNG_COLORSPACE_SUPPORTED is only required if the application will perform + * colorspace corrections, otherwise all the colorspace information can be + * skipped and the size of libpng can be reduced (significantly) by compiling + * out the colorspace support. + */ +#ifdef PNG_COLORSPACE_SUPPORTED +/* The chromaticities of the red, green and blue colorants and the chromaticity + * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)). + */ +typedef struct png_xy +{ + png_fixed_point redx, redy; + png_fixed_point greenx, greeny; + png_fixed_point bluex, bluey; + png_fixed_point whitex, whitey; +} png_xy; + +/* The same data as above but encoded as CIE XYZ values. When this data comes + * from chromaticities the sum of the Y values is assumed to be 1.0 + */ +typedef struct png_XYZ +{ + png_fixed_point red_X, red_Y, red_Z; + png_fixed_point green_X, green_Y, green_Z; + png_fixed_point blue_X, blue_Y, blue_Z; +} png_XYZ; +#endif /* COLORSPACE */ + +#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) +/* A colorspace is all the above plus, potentially, profile information; + * however at present libpng does not use the profile internally so it is only + * stored in the png_info struct (if iCCP is supported.) The rendering intent + * is retained here and is checked. + * + * The file gamma encoding information is also stored here and gamma correction + * is done by libpng, whereas color correction must currently be done by the + * application. + */ +typedef struct png_colorspace +{ +#ifdef PNG_GAMMA_SUPPORTED + png_fixed_point gamma; /* File gamma */ +#endif + +#ifdef PNG_COLORSPACE_SUPPORTED + png_xy end_points_xy; /* End points as chromaticities */ + png_XYZ end_points_XYZ; /* End points as CIE XYZ colorant values */ + png_uint_16 rendering_intent; /* Rendering intent of a profile */ +#endif + + /* Flags are always defined to simplify the code. */ + png_uint_16 flags; /* As defined below */ +} png_colorspace, * PNG_RESTRICT png_colorspacerp; + +typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp; + +/* General flags for the 'flags' field */ +#define PNG_COLORSPACE_HAVE_GAMMA 0x0001 +#define PNG_COLORSPACE_HAVE_ENDPOINTS 0x0002 +#define PNG_COLORSPACE_HAVE_INTENT 0x0004 +#define PNG_COLORSPACE_FROM_gAMA 0x0008 +#define PNG_COLORSPACE_FROM_cHRM 0x0010 +#define PNG_COLORSPACE_FROM_sRGB 0x0020 +#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040 +#define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */ +#define PNG_COLORSPACE_INVALID 0x8000 +#define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags)) +#endif /* COLORSPACE || GAMMA */ + +struct png_struct_def +{ +#ifdef PNG_SETJMP_SUPPORTED + jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */ + png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */ + jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */ + size_t jmp_buf_size; /* size of the above, if allocated */ +#endif + png_error_ptr error_fn; /* function for printing errors and aborting */ +#ifdef PNG_WARNINGS_SUPPORTED + png_error_ptr warning_fn; /* function for printing warnings */ +#endif + png_voidp error_ptr; /* user supplied struct for error functions */ + png_rw_ptr write_data_fn; /* function for writing output data */ + png_rw_ptr read_data_fn; /* function for reading input data */ + png_voidp io_ptr; /* ptr to application struct for I/O functions */ + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + png_user_transform_ptr read_user_transform_fn; /* user read transform */ +#endif + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED + png_user_transform_ptr write_user_transform_fn; /* user write transform */ +#endif + +/* These were added in libpng-1.0.2 */ +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) + png_voidp user_transform_ptr; /* user supplied struct for user transform */ + png_byte user_transform_depth; /* bit depth of user transformed pixels */ + png_byte user_transform_channels; /* channels in user transformed pixels */ +#endif +#endif + + png_uint_32 mode; /* tells us where we are in the PNG file */ + png_uint_32 flags; /* flags indicating various things to libpng */ + png_uint_32 transformations; /* which transformations to perform */ + + png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */ + z_stream zstream; /* decompression structure */ + +#ifdef PNG_WRITE_SUPPORTED + png_compression_bufferp zbuffer_list; /* Created on demand during write */ + uInt zbuffer_size; /* size of the actual buffer */ + + int zlib_level; /* holds zlib compression level */ + int zlib_method; /* holds zlib compression method */ + int zlib_window_bits; /* holds zlib compression window bits */ + int zlib_mem_level; /* holds zlib compression memory level */ + int zlib_strategy; /* holds zlib compression strategy */ +#endif +/* Added at libpng 1.5.4 */ +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED + int zlib_text_level; /* holds zlib compression level */ + int zlib_text_method; /* holds zlib compression method */ + int zlib_text_window_bits; /* holds zlib compression window bits */ + int zlib_text_mem_level; /* holds zlib compression memory level */ + int zlib_text_strategy; /* holds zlib compression strategy */ +#endif +/* End of material added at libpng 1.5.4 */ +/* Added at libpng 1.6.0 */ +#ifdef PNG_WRITE_SUPPORTED + int zlib_set_level; /* Actual values set into the zstream on write */ + int zlib_set_method; + int zlib_set_window_bits; + int zlib_set_mem_level; + int zlib_set_strategy; +#endif + + png_uint_32 width; /* width of image in pixels */ + png_uint_32 height; /* height of image in pixels */ + png_uint_32 num_rows; /* number of rows in current pass */ + png_uint_32 usr_width; /* width of row at start of write */ + size_t rowbytes; /* size of row in bytes */ + png_uint_32 iwidth; /* width of current interlaced row in pixels */ + png_uint_32 row_number; /* current row in interlace pass */ + png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */ + png_bytep prev_row; /* buffer to save previous (unfiltered) row. + * While reading this is a pointer into + * big_prev_row; while writing it is separately + * allocated if needed. + */ + png_bytep row_buf; /* buffer to save current (unfiltered) row. + * While reading, this is a pointer into + * big_row_buf; while writing it is separately + * allocated. + */ +#ifdef PNG_WRITE_FILTER_SUPPORTED + png_bytep try_row; /* buffer to save trial row when filtering */ + png_bytep tst_row; /* buffer to save best trial row when filtering */ +#endif + size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */ + + png_uint_32 idat_size; /* current IDAT size for read */ + png_uint_32 crc; /* current chunk CRC value */ + png_colorp palette; /* palette from the input file */ + png_uint_16 num_palette; /* number of color entries in palette */ + +/* Added at libpng-1.5.10 */ +#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED + int num_palette_max; /* maximum palette index found in IDAT */ +#endif + + png_uint_16 num_trans; /* number of transparency values */ + png_byte compression; /* file compression type (always 0) */ + png_byte filter; /* file filter type (always 0) */ + png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ + png_byte pass; /* current interlace pass (0 - 6) */ + png_byte do_filter; /* row filter flags (see PNG_FILTER_ in png.h ) */ + png_byte color_type; /* color type of file */ + png_byte bit_depth; /* bit depth of file */ + png_byte usr_bit_depth; /* bit depth of users row: write only */ + png_byte pixel_depth; /* number of bits per pixel */ + png_byte channels; /* number of channels in file */ +#ifdef PNG_WRITE_SUPPORTED + png_byte usr_channels; /* channels at start of write: write only */ +#endif + png_byte sig_bytes; /* magic bytes read/written from start of file */ + png_byte maximum_pixel_depth; + /* pixel depth used for the row buffers */ + png_byte transformed_pixel_depth; + /* pixel depth after read/write transforms */ +#if ZLIB_VERNUM >= 0x1240 + png_byte zstream_start; /* at start of an input zlib stream */ +#endif /* Zlib >= 1.2.4 */ +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) + png_uint_16 filler; /* filler bytes for pixel expansion */ +#endif + +#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) + png_byte background_gamma_type; + png_fixed_point background_gamma; + png_color_16 background; /* background color in screen gamma space */ +#ifdef PNG_READ_GAMMA_SUPPORTED + png_color_16 background_1; /* background normalized to gamma 1.0 */ +#endif +#endif /* bKGD */ + +#ifdef PNG_WRITE_FLUSH_SUPPORTED + png_flush_ptr output_flush_fn; /* Function for flushing output */ + png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */ + png_uint_32 flush_rows; /* number of rows written since last flush */ +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED + int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */ + png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */ + + png_bytep gamma_table; /* gamma table for 8-bit depth files */ + png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */ +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) + png_bytep gamma_from_1; /* converts from 1.0 to screen */ + png_bytep gamma_to_1; /* converts from file to 1.0 */ + png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */ + png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */ +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED) + png_color_8 sig_bit; /* significant bits in each available channel */ +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) + png_color_8 shift; /* shift for significant bit transformation */ +#endif + +#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \ + || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + png_bytep trans_alpha; /* alpha values for paletted files */ + png_color_16 trans_color; /* transparent color for non-paletted files */ +#endif + + png_read_status_ptr read_row_fn; /* called after each row is decoded */ + png_write_status_ptr write_row_fn; /* called after each row is encoded */ +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + png_progressive_info_ptr info_fn; /* called after header data fully read */ + png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */ + png_progressive_end_ptr end_fn; /* called after image is complete */ + png_bytep save_buffer_ptr; /* current location in save_buffer */ + png_bytep save_buffer; /* buffer for previously read data */ + png_bytep current_buffer_ptr; /* current location in current_buffer */ + png_bytep current_buffer; /* buffer for recently used data */ + png_uint_32 push_length; /* size of current input chunk */ + png_uint_32 skip_length; /* bytes to skip in input data */ + size_t save_buffer_size; /* amount of data now in save_buffer */ + size_t save_buffer_max; /* total size of save_buffer */ + size_t buffer_size; /* total amount of available input data */ + size_t current_buffer_size; /* amount of data now in current_buffer */ + int process_mode; /* what push library is currently doing */ + int cur_palette; /* current push library palette index */ + +#endif /* PROGRESSIVE_READ */ + +#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) +/* For the Borland special 64K segment handler */ + png_bytepp offset_table_ptr; + png_bytep offset_table; + png_uint_16 offset_table_number; + png_uint_16 offset_table_count; + png_uint_16 offset_table_count_free; +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + png_bytep palette_lookup; /* lookup table for quantizing */ + png_bytep quantize_index; /* index translation for palette files */ +#endif + +/* Options */ +#ifdef PNG_SET_OPTION_SUPPORTED + png_uint_32 options; /* On/off state (up to 16 options) */ +#endif + +#if PNG_LIBPNG_VER < 10700 +/* To do: remove this from libpng-1.7 */ +#ifdef PNG_TIME_RFC1123_SUPPORTED + char time_buffer[29]; /* String to hold RFC 1123 time text */ +#endif +#endif + +/* New members added in libpng-1.0.6 */ + + png_uint_32 free_me; /* flags items libpng is responsible for freeing */ + +#ifdef PNG_USER_CHUNKS_SUPPORTED + png_voidp user_chunk_ptr; +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED + png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */ +#endif +#endif + +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + int unknown_default; /* As PNG_HANDLE_* */ + unsigned int num_chunk_list; /* Number of entries in the list */ + png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name + * followed by a PNG_HANDLE_* byte */ +#endif + +/* New members added in libpng-1.0.3 */ +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + png_byte rgb_to_gray_status; + /* Added in libpng 1.5.5 to record setting of coefficients: */ + png_byte rgb_to_gray_coefficients_set; + /* These were changed from png_byte in libpng-1.0.6 */ + png_uint_16 rgb_to_gray_red_coeff; + png_uint_16 rgb_to_gray_green_coeff; + /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */ +#endif + +/* New member added in libpng-1.6.36 */ +#if defined(PNG_READ_EXPAND_SUPPORTED) && \ + defined(PNG_ARM_NEON_IMPLEMENTATION) + png_bytep riffled_palette; /* buffer for accelerated palette expansion */ +#endif + +/* New member added in libpng-1.0.4 (renamed in 1.0.9) */ +#if defined(PNG_MNG_FEATURES_SUPPORTED) +/* Changed from png_byte to png_uint_32 at version 1.2.0 */ + png_uint_32 mng_features_permitted; +#endif + +/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */ +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_byte filter_type; +#endif + +#ifdef PNG_APNG_SUPPORTED + png_uint_32 apng_flags; + png_uint_32 next_seq_num; /* next fcTL/fdAT chunk sequence number */ + png_uint_32 first_frame_width; + png_uint_32 first_frame_height; + +#ifdef PNG_READ_APNG_SUPPORTED + png_uint_32 num_frames_read; /* incremented after all image data of */ + /* a frame is read */ +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + png_progressive_frame_ptr frame_info_fn; /* frame info read callback */ + png_progressive_frame_ptr frame_end_fn; /* frame data read callback */ +#endif +#endif + +#ifdef PNG_WRITE_APNG_SUPPORTED + png_uint_32 num_frames_to_write; + png_uint_32 num_frames_written; +#endif +#endif /* APNG */ + +/* New members added in libpng-1.2.0 */ + +/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */ +#ifdef PNG_USER_MEM_SUPPORTED + png_voidp mem_ptr; /* user supplied struct for mem functions */ + png_malloc_ptr malloc_fn; /* function for allocating memory */ + png_free_ptr free_fn; /* function for freeing memory */ +#endif + +/* New member added in libpng-1.0.13 and 1.2.0 */ + png_bytep big_row_buf; /* buffer to save current (unfiltered) row */ + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +/* The following three members were added at version 1.0.14 and 1.2.4 */ + png_bytep quantize_sort; /* working sort array */ + png_bytep index_to_palette; /* where the original index currently is + in the palette */ + png_bytep palette_to_index; /* which original index points to this + palette color */ +#endif + +/* New members added in libpng-1.0.16 and 1.2.6 */ + png_byte compression_type; + +#ifdef PNG_USER_LIMITS_SUPPORTED + png_uint_32 user_width_max; + png_uint_32 user_height_max; + + /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown + * chunks that can be stored (0 means unlimited). + */ + png_uint_32 user_chunk_cache_max; + + /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk + * can occupy when decompressed. 0 means unlimited. + */ + png_alloc_size_t user_chunk_malloc_max; +#endif + +/* New member added in libpng-1.0.25 and 1.2.17 */ +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED + /* Temporary storage for unknown chunk that the library doesn't recognize, + * used while reading the chunk. + */ + png_unknown_chunk unknown_chunk; +#endif + +/* New member added in libpng-1.2.26 */ + size_t old_big_row_buf_size; + +#ifdef PNG_READ_SUPPORTED +/* New member added in libpng-1.2.30 */ + png_bytep read_buffer; /* buffer for reading chunk data */ + png_alloc_size_t read_buffer_size; /* current size of the buffer */ +#endif +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED + uInt IDAT_read_size; /* limit on read buffer size for IDAT */ +#endif + +#ifdef PNG_IO_STATE_SUPPORTED +/* New member added in libpng-1.4.0 */ + png_uint_32 io_state; +#endif + +/* New member added in libpng-1.5.6 */ + png_bytep big_prev_row; + +/* New member added in libpng-1.5.7 */ + void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info, + png_bytep row, png_const_bytep prev_row); + +#ifdef PNG_READ_SUPPORTED +#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) + png_colorspace colorspace; +#endif +#endif +}; +#endif /* PNGSTRUCT_H */ diff --git a/media/libpng/pngtrans.c b/media/libpng/pngtrans.c new file mode 100644 index 0000000000..1100f46ebe --- /dev/null +++ b/media/libpng/pngtrans.c @@ -0,0 +1,864 @@ + +/* pngtrans.c - transforms the data in a row (used by both readers and writers) + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* Turn on BGR-to-RGB mapping */ +void PNGAPI +png_set_bgr(png_structrp png_ptr) +{ + png_debug(1, "in png_set_bgr"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_BGR; +} +#endif + +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* Turn on 16-bit byte swapping */ +void PNGAPI +png_set_swap(png_structrp png_ptr) +{ + png_debug(1, "in png_set_swap"); + + if (png_ptr == NULL) + return; + + if (png_ptr->bit_depth == 16) + png_ptr->transformations |= PNG_SWAP_BYTES; +} +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) +/* Turn on pixel packing */ +void PNGAPI +png_set_packing(png_structrp png_ptr) +{ + png_debug(1, "in png_set_packing"); + + if (png_ptr == NULL) + return; + + if (png_ptr->bit_depth < 8) + { + png_ptr->transformations |= PNG_PACK; +# ifdef PNG_WRITE_SUPPORTED + png_ptr->usr_bit_depth = 8; +# endif + } +} +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) +/* Turn on packed pixel swapping */ +void PNGAPI +png_set_packswap(png_structrp png_ptr) +{ + png_debug(1, "in png_set_packswap"); + + if (png_ptr == NULL) + return; + + if (png_ptr->bit_depth < 8) + png_ptr->transformations |= PNG_PACKSWAP; +} +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) +void PNGAPI +png_set_shift(png_structrp png_ptr, png_const_color_8p true_bits) +{ + png_debug(1, "in png_set_shift"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_SHIFT; + png_ptr->shift = *true_bits; +} +#endif + +#if defined(PNG_READ_INTERLACING_SUPPORTED) || \ + defined(PNG_WRITE_INTERLACING_SUPPORTED) +int PNGAPI +png_set_interlace_handling(png_structrp png_ptr) +{ + png_debug(1, "in png_set_interlace handling"); + + if (png_ptr != 0 && png_ptr->interlaced != 0) + { + png_ptr->transformations |= PNG_INTERLACE; + return (7); + } + + return (1); +} +#endif + +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) +/* Add a filler byte on read, or remove a filler or alpha byte on write. + * The filler type has changed in v0.95 to allow future 2-byte fillers + * for 48-bit input data, as well as to avoid problems with some compilers + * that don't like bytes as parameters. + */ +void PNGAPI +png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc) +{ + png_debug(1, "in png_set_filler"); + + if (png_ptr == NULL) + return; + + /* In libpng 1.6 it is possible to determine whether this is a read or write + * operation and therefore to do more checking here for a valid call. + */ + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) + { +# ifdef PNG_READ_FILLER_SUPPORTED + /* On read png_set_filler is always valid, regardless of the base PNG + * format, because other transformations can give a format where the + * filler code can execute (basically an 8 or 16-bit component RGB or G + * format.) + * + * NOTE: usr_channels is not used by the read code! (This has led to + * confusion in the past.) The filler is only used in the read code. + */ + png_ptr->filler = (png_uint_16)filler; +# else + png_app_error(png_ptr, "png_set_filler not supported on read"); + PNG_UNUSED(filler) /* not used in the write case */ + return; +# endif + } + + else /* write */ + { +# ifdef PNG_WRITE_FILLER_SUPPORTED + /* On write the usr_channels parameter must be set correctly at the + * start to record the number of channels in the app-supplied data. + */ + switch (png_ptr->color_type) + { + case PNG_COLOR_TYPE_RGB: + png_ptr->usr_channels = 4; + break; + + case PNG_COLOR_TYPE_GRAY: + if (png_ptr->bit_depth >= 8) + { + png_ptr->usr_channels = 2; + break; + } + + else + { + /* There simply isn't any code in libpng to strip out bits + * from bytes when the components are less than a byte in + * size! + */ + png_app_error(png_ptr, + "png_set_filler is invalid for" + " low bit depth gray output"); + return; + } + + default: + png_app_error(png_ptr, + "png_set_filler: inappropriate color type"); + return; + } +# else + png_app_error(png_ptr, "png_set_filler not supported on write"); + return; +# endif + } + + /* Here on success - libpng supports the operation, set the transformation + * and the flag to say where the filler channel is. + */ + png_ptr->transformations |= PNG_FILLER; + + if (filler_loc == PNG_FILLER_AFTER) + png_ptr->flags |= PNG_FLAG_FILLER_AFTER; + + else + png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER; +} + +/* Added to libpng-1.2.7 */ +void PNGAPI +png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc) +{ + png_debug(1, "in png_set_add_alpha"); + + if (png_ptr == NULL) + return; + + png_set_filler(png_ptr, filler, filler_loc); + /* The above may fail to do anything. */ + if ((png_ptr->transformations & PNG_FILLER) != 0) + png_ptr->transformations |= PNG_ADD_ALPHA; +} + +#endif + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) +void PNGAPI +png_set_swap_alpha(png_structrp png_ptr) +{ + png_debug(1, "in png_set_swap_alpha"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_SWAP_ALPHA; +} +#endif + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) +void PNGAPI +png_set_invert_alpha(png_structrp png_ptr) +{ + png_debug(1, "in png_set_invert_alpha"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_INVERT_ALPHA; +} +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +void PNGAPI +png_set_invert_mono(png_structrp png_ptr) +{ + png_debug(1, "in png_set_invert_mono"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_INVERT_MONO; +} + +/* Invert monochrome grayscale data */ +void /* PRIVATE */ +png_do_invert(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_invert"); + + /* This test removed from libpng version 1.0.13 and 1.2.0: + * if (row_info->bit_depth == 1 && + */ + if (row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + png_bytep rp = row; + size_t i; + size_t istop = row_info->rowbytes; + + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(~(*rp)); + rp++; + } + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && + row_info->bit_depth == 8) + { + png_bytep rp = row; + size_t i; + size_t istop = row_info->rowbytes; + + for (i = 0; i < istop; i += 2) + { + *rp = (png_byte)(~(*rp)); + rp += 2; + } + } + +#ifdef PNG_16BIT_SUPPORTED + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && + row_info->bit_depth == 16) + { + png_bytep rp = row; + size_t i; + size_t istop = row_info->rowbytes; + + for (i = 0; i < istop; i += 4) + { + *rp = (png_byte)(~(*rp)); + *(rp + 1) = (png_byte)(~(*(rp + 1))); + rp += 4; + } + } +#endif +} +#endif + +#ifdef PNG_16BIT_SUPPORTED +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* Swaps byte order on 16-bit depth images */ +void /* PRIVATE */ +png_do_swap(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_swap"); + + if (row_info->bit_depth == 16) + { + png_bytep rp = row; + png_uint_32 i; + png_uint_32 istop= row_info->width * row_info->channels; + + for (i = 0; i < istop; i++, rp += 2) + { +#ifdef PNG_BUILTIN_BSWAP16_SUPPORTED + /* Feature added to libpng-1.6.11 for testing purposes, not + * enabled by default. + */ + *(png_uint_16*)rp = __builtin_bswap16(*(png_uint_16*)rp); +#else + png_byte t = *rp; + *rp = *(rp + 1); + *(rp + 1) = t; +#endif + } + } +} +#endif +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) +static const png_byte onebppswaptable[256] = { + 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, + 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0, + 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, + 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8, + 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, + 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4, + 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, + 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC, + 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, + 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2, + 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, + 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA, + 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, + 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6, + 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, + 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE, + 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, + 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1, + 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, + 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9, + 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, + 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5, + 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, + 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD, + 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, + 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3, + 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, + 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB, + 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, + 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7, + 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, + 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF +}; + +static const png_byte twobppswaptable[256] = { + 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0, + 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0, + 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4, + 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4, + 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8, + 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8, + 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC, + 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC, + 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1, + 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1, + 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5, + 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5, + 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9, + 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9, + 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD, + 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD, + 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2, + 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2, + 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6, + 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6, + 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA, + 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA, + 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE, + 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE, + 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3, + 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3, + 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7, + 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7, + 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB, + 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB, + 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF, + 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF +}; + +static const png_byte fourbppswaptable[256] = { + 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, + 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0, + 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71, + 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1, + 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72, + 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2, + 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73, + 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3, + 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74, + 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4, + 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75, + 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5, + 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76, + 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6, + 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77, + 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7, + 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78, + 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8, + 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79, + 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9, + 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A, + 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA, + 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B, + 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB, + 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C, + 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC, + 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D, + 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD, + 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E, + 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE, + 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F, + 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF +}; + +/* Swaps pixel packing order within bytes */ +void /* PRIVATE */ +png_do_packswap(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_packswap"); + + if (row_info->bit_depth < 8) + { + png_bytep rp; + png_const_bytep end, table; + + end = row + row_info->rowbytes; + + if (row_info->bit_depth == 1) + table = onebppswaptable; + + else if (row_info->bit_depth == 2) + table = twobppswaptable; + + else if (row_info->bit_depth == 4) + table = fourbppswaptable; + + else + return; + + for (rp = row; rp < end; rp++) + *rp = table[*rp]; + } +} +#endif /* PACKSWAP || WRITE_PACKSWAP */ + +#if defined(PNG_WRITE_FILLER_SUPPORTED) || \ + defined(PNG_READ_STRIP_ALPHA_SUPPORTED) +/* Remove a channel - this used to be 'png_do_strip_filler' but it used a + * somewhat weird combination of flags to determine what to do. All the calls + * to png_do_strip_filler are changed in 1.5.2 to call this instead with the + * correct arguments. + * + * The routine isn't general - the channel must be the channel at the start or + * end (not in the middle) of each pixel. + */ +void /* PRIVATE */ +png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start) +{ + png_bytep sp = row; /* source pointer */ + png_bytep dp = row; /* destination pointer */ + png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */ + + /* At the start sp will point to the first byte to copy and dp to where + * it is copied to. ep always points just beyond the end of the row, so + * the loop simply copies (channels-1) channels until sp reaches ep. + * + * at_start: 0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc. + * nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc. + */ + + /* GA, GX, XG cases */ + if (row_info->channels == 2) + { + if (row_info->bit_depth == 8) + { + if (at_start != 0) /* Skip initial filler */ + ++sp; + else /* Skip initial channel and, for sp, the filler */ + { + sp += 2; ++dp; + } + + /* For a 1 pixel wide image there is nothing to do */ + while (sp < ep) + { + *dp++ = *sp; sp += 2; + } + + row_info->pixel_depth = 8; + } + + else if (row_info->bit_depth == 16) + { + if (at_start != 0) /* Skip initial filler */ + sp += 2; + else /* Skip initial channel and, for sp, the filler */ + { + sp += 4; dp += 2; + } + + while (sp < ep) + { + *dp++ = *sp++; *dp++ = *sp; sp += 3; + } + + row_info->pixel_depth = 16; + } + + else + return; /* bad bit depth */ + + row_info->channels = 1; + + /* Finally fix the color type if it records an alpha channel */ + if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + row_info->color_type = PNG_COLOR_TYPE_GRAY; + } + + /* RGBA, RGBX, XRGB cases */ + else if (row_info->channels == 4) + { + if (row_info->bit_depth == 8) + { + if (at_start != 0) /* Skip initial filler */ + ++sp; + else /* Skip initial channels and, for sp, the filler */ + { + sp += 4; dp += 3; + } + + /* Note that the loop adds 3 to dp and 4 to sp each time. */ + while (sp < ep) + { + *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp; sp += 2; + } + + row_info->pixel_depth = 24; + } + + else if (row_info->bit_depth == 16) + { + if (at_start != 0) /* Skip initial filler */ + sp += 2; + else /* Skip initial channels and, for sp, the filler */ + { + sp += 8; dp += 6; + } + + while (sp < ep) + { + /* Copy 6 bytes, skip 2 */ + *dp++ = *sp++; *dp++ = *sp++; + *dp++ = *sp++; *dp++ = *sp++; + *dp++ = *sp++; *dp++ = *sp; sp += 3; + } + + row_info->pixel_depth = 48; + } + + else + return; /* bad bit depth */ + + row_info->channels = 3; + + /* Finally fix the color type if it records an alpha channel */ + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + row_info->color_type = PNG_COLOR_TYPE_RGB; + } + + else + return; /* The filler channel has gone already */ + + /* Fix the rowbytes value. */ + row_info->rowbytes = (size_t)(dp-row); +} +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* Swaps red and blue bytes within a pixel */ +void /* PRIVATE */ +png_do_bgr(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_bgr"); + + if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + png_uint_32 row_width = row_info->width; + if (row_info->bit_depth == 8) + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_width; i++, rp += 3) + { + png_byte save = *rp; + *rp = *(rp + 2); + *(rp + 2) = save; + } + } + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_width; i++, rp += 4) + { + png_byte save = *rp; + *rp = *(rp + 2); + *(rp + 2) = save; + } + } + } + +#ifdef PNG_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_width; i++, rp += 6) + { + png_byte save = *rp; + *rp = *(rp + 4); + *(rp + 4) = save; + save = *(rp + 1); + *(rp + 1) = *(rp + 5); + *(rp + 5) = save; + } + } + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_width; i++, rp += 8) + { + png_byte save = *rp; + *rp = *(rp + 4); + *(rp + 4) = save; + save = *(rp + 1); + *(rp + 1) = *(rp + 5); + *(rp + 5) = save; + } + } + } +#endif + } +} +#endif /* READ_BGR || WRITE_BGR */ + +#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \ + defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED) +/* Added at libpng-1.5.10 */ +void /* PRIVATE */ +png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info) +{ + if (png_ptr->num_palette < (1 << row_info->bit_depth) && + png_ptr->num_palette > 0) /* num_palette can be 0 in MNG files */ + { + /* Calculations moved outside switch in an attempt to stop different + * compiler warnings. 'padding' is in *bits* within the last byte, it is + * an 'int' because pixel_depth becomes an 'int' in the expression below, + * and this calculation is used because it avoids warnings that other + * forms produced on either GCC or MSVC. + */ + int padding = PNG_PADBITS(row_info->pixel_depth, row_info->width); + png_bytep rp = png_ptr->row_buf + row_info->rowbytes - 1; + + switch (row_info->bit_depth) + { + case 1: + { + /* in this case, all bytes must be 0 so we don't need + * to unpack the pixels except for the rightmost one. + */ + for (; rp > png_ptr->row_buf; rp--) + { + if ((*rp >> padding) != 0) + png_ptr->num_palette_max = 1; + padding = 0; + } + + break; + } + + case 2: + { + for (; rp > png_ptr->row_buf; rp--) + { + int i = ((*rp >> padding) & 0x03); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + i = (((*rp >> padding) >> 2) & 0x03); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + i = (((*rp >> padding) >> 4) & 0x03); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + i = (((*rp >> padding) >> 6) & 0x03); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + padding = 0; + } + + break; + } + + case 4: + { + for (; rp > png_ptr->row_buf; rp--) + { + int i = ((*rp >> padding) & 0x0f); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + i = (((*rp >> padding) >> 4) & 0x0f); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + padding = 0; + } + + break; + } + + case 8: + { + for (; rp > png_ptr->row_buf; rp--) + { + if (*rp > png_ptr->num_palette_max) + png_ptr->num_palette_max = (int) *rp; + } + + break; + } + + default: + break; + } + } +} +#endif /* CHECK_FOR_INVALID_INDEX */ + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +void PNGAPI +png_set_user_transform_info(png_structrp png_ptr, png_voidp + user_transform_ptr, int user_transform_depth, int user_transform_channels) +{ + png_debug(1, "in png_set_user_transform_info"); + + if (png_ptr == NULL) + return; + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && + (png_ptr->flags & PNG_FLAG_ROW_INIT) != 0) + { + png_app_error(png_ptr, + "info change after png_start_read_image or png_read_update_info"); + return; + } +#endif + + png_ptr->user_transform_ptr = user_transform_ptr; + png_ptr->user_transform_depth = (png_byte)user_transform_depth; + png_ptr->user_transform_channels = (png_byte)user_transform_channels; +} +#endif + +/* This function returns a pointer to the user_transform_ptr associated with + * the user transform functions. The application should free any memory + * associated with this pointer before png_write_destroy and png_read_destroy + * are called. + */ +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +png_voidp PNGAPI +png_get_user_transform_ptr(png_const_structrp png_ptr) +{ + if (png_ptr == NULL) + return (NULL); + + return png_ptr->user_transform_ptr; +} +#endif + +#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED +png_uint_32 PNGAPI +png_get_current_row_number(png_const_structrp png_ptr) +{ + /* See the comments in png.h - this is the sub-image row when reading an + * interlaced image. + */ + if (png_ptr != NULL) + return png_ptr->row_number; + + return PNG_UINT_32_MAX; /* help the app not to fail silently */ +} + +png_byte PNGAPI +png_get_current_pass_number(png_const_structrp png_ptr) +{ + if (png_ptr != NULL) + return png_ptr->pass; + return 8; /* invalid */ +} +#endif /* USER_TRANSFORM_INFO */ +#endif /* READ_USER_TRANSFORM || WRITE_USER_TRANSFORM */ +#endif /* READ || WRITE */ diff --git a/media/libpng/pngwio.c b/media/libpng/pngwio.c new file mode 100644 index 0000000000..10e919dd03 --- /dev/null +++ b/media/libpng/pngwio.c @@ -0,0 +1,168 @@ + +/* pngwio.c - functions for data output + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2014,2016,2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all output. Users who need + * special handling are expected to write functions that have the same + * arguments as these and perform similar functions, but that possibly + * use different output methods. Note that you shouldn't change these + * functions, but rather write replacement functions and then change + * them at run time with png_set_write_fn(...). + */ + +#include "pngpriv.h" + +#ifdef PNG_WRITE_SUPPORTED + +/* Write the data to whatever output you are using. The default routine + * writes to a file pointer. Note that this routine sometimes gets called + * with very small lengths, so you should implement some kind of simple + * buffering if you are using unbuffered writes. This should never be asked + * to write more than 64K on a 16-bit machine. + */ + +void /* PRIVATE */ +png_write_data(png_structrp png_ptr, png_const_bytep data, size_t length) +{ + /* NOTE: write_data_fn must not change the buffer! */ + if (png_ptr->write_data_fn != NULL ) + (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data), + length); + + else + png_error(png_ptr, "Call to NULL write function"); +} + +#ifdef PNG_STDIO_SUPPORTED +/* This is the function that does the actual writing of data. If you are + * not writing to a standard C stream, you should create a replacement + * write_data function and use it at run time with png_set_write_fn(), rather + * than changing the library. + */ +void PNGCBAPI +png_default_write_data(png_structp png_ptr, png_bytep data, size_t length) +{ + size_t check; + + if (png_ptr == NULL) + return; + + check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr)); + + if (check != length) + png_error(png_ptr, "Write Error"); +} +#endif + +/* This function is called to output any data pending writing (normally + * to disk). After png_flush is called, there should be no data pending + * writing in any buffers. + */ +#ifdef PNG_WRITE_FLUSH_SUPPORTED +void /* PRIVATE */ +png_flush(png_structrp png_ptr) +{ + if (png_ptr->output_flush_fn != NULL) + (*(png_ptr->output_flush_fn))(png_ptr); +} + +# ifdef PNG_STDIO_SUPPORTED +void PNGCBAPI +png_default_flush(png_structp png_ptr) +{ + png_FILE_p io_ptr; + + if (png_ptr == NULL) + return; + + io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr)); + fflush(io_ptr); +} +# endif +#endif + +/* This function allows the application to supply new output functions for + * libpng if standard C streams aren't being used. + * + * This function takes as its arguments: + * png_ptr - pointer to a png output data structure + * io_ptr - pointer to user supplied structure containing info about + * the output functions. May be NULL. + * write_data_fn - pointer to a new output function that takes as its + * arguments a pointer to a png_struct, a pointer to + * data to be written, and a 32-bit unsigned int that is + * the number of bytes to be written. The new write + * function should call png_error(png_ptr, "Error msg") + * to exit and output any fatal error messages. May be + * NULL, in which case libpng's default function will + * be used. + * flush_data_fn - pointer to a new flush function that takes as its + * arguments a pointer to a png_struct. After a call to + * the flush function, there should be no data in any buffers + * or pending transmission. If the output method doesn't do + * any buffering of output, a function prototype must still be + * supplied although it doesn't have to do anything. If + * PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile + * time, output_flush_fn will be ignored, although it must be + * supplied for compatibility. May be NULL, in which case + * libpng's default function will be used, if + * PNG_WRITE_FLUSH_SUPPORTED is defined. This is not + * a good idea if io_ptr does not point to a standard + * *FILE structure. + */ +void PNGAPI +png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr, + png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->io_ptr = io_ptr; + +#ifdef PNG_STDIO_SUPPORTED + if (write_data_fn != NULL) + png_ptr->write_data_fn = write_data_fn; + + else + png_ptr->write_data_fn = png_default_write_data; +#else + png_ptr->write_data_fn = write_data_fn; +#endif + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +# ifdef PNG_STDIO_SUPPORTED + + if (output_flush_fn != NULL) + png_ptr->output_flush_fn = output_flush_fn; + + else + png_ptr->output_flush_fn = png_default_flush; + +# else + png_ptr->output_flush_fn = output_flush_fn; +# endif +#else + PNG_UNUSED(output_flush_fn) +#endif /* WRITE_FLUSH */ + +#ifdef PNG_READ_SUPPORTED + /* It is an error to read while writing a png file */ + if (png_ptr->read_data_fn != NULL) + { + png_ptr->read_data_fn = NULL; + + png_warning(png_ptr, + "Can't set both read_data_fn and write_data_fn in the" + " same structure"); + } +#endif +} +#endif /* WRITE */ diff --git a/media/libpng/pngwrite.c b/media/libpng/pngwrite.c new file mode 100644 index 0000000000..6bae1e05a0 --- /dev/null +++ b/media/libpng/pngwrite.c @@ -0,0 +1,2442 @@ + +/* pngwrite.c - general routines to write a PNG file + * + * Copyright (c) 2018-2019 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" +#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED +# include <errno.h> +#endif /* SIMPLIFIED_WRITE_STDIO */ + +#ifdef PNG_WRITE_SUPPORTED + +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED +/* Write out all the unknown chunks for the current given location */ +static void +write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr, + unsigned int where) +{ + if (info_ptr->unknown_chunks_num != 0) + { + png_const_unknown_chunkp up; + + png_debug(5, "writing extra chunks"); + + for (up = info_ptr->unknown_chunks; + up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num; + ++up) + if ((up->location & where) != 0) + { + /* If per-chunk unknown chunk handling is enabled use it, otherwise + * just write the chunks the application has set. + */ +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + int keep = png_handle_as_unknown(png_ptr, up->name); + + /* NOTE: this code is radically different from the read side in the + * matter of handling an ancillary unknown chunk. In the read side + * the default behavior is to discard it, in the code below the default + * behavior is to write it. Critical chunks are, however, only + * written if explicitly listed or if the default is set to write all + * unknown chunks. + * + * The default handling is also slightly weird - it is not possible to + * stop the writing of all unsafe-to-copy chunks! + * + * TODO: REVIEW: this would seem to be a bug. + */ + if (keep != PNG_HANDLE_CHUNK_NEVER && + ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ || + keep == PNG_HANDLE_CHUNK_ALWAYS || + (keep == PNG_HANDLE_CHUNK_AS_DEFAULT && + png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS))) +#endif + { + /* TODO: review, what is wrong with a zero length unknown chunk? */ + if (up->size == 0) + png_warning(png_ptr, "Writing zero-length unknown chunk"); + + png_write_chunk(png_ptr, up->name, up->data, up->size); + } + } + } +} +#endif /* WRITE_UNKNOWN_CHUNKS */ + +/* Writes all the PNG information. This is the suggested way to use the + * library. If you have a new chunk to add, make a function to write it, + * and put it in the correct location here. If you want the chunk written + * after the image data, put it in png_write_end(). I strongly encourage + * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing + * the chunk, as that will keep the code from breaking if you want to just + * write a plain PNG file. If you have long comments, I suggest writing + * them in png_write_end(), and compressing them. + */ +void PNGAPI +png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr) +{ + png_debug(1, "in png_write_info_before_PLTE"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0) + { + /* Write PNG signature */ + png_write_sig(png_ptr); + +#ifdef PNG_MNG_FEATURES_SUPPORTED + if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && \ + png_ptr->mng_features_permitted != 0) + { + png_warning(png_ptr, + "MNG features are not allowed in a PNG datastream"); + png_ptr->mng_features_permitted = 0; + } +#endif + + /* Write IHDR information. */ + png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height, + info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type, + info_ptr->filter_type, +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + info_ptr->interlace_type +#else + 0 +#endif + ); + + /* The rest of these check to see if the valid field has the appropriate + * flag set, and if it does, writes the chunk. + * + * 1.6.0: COLORSPACE support controls the writing of these chunks too, and + * the chunks will be written if the WRITE routine is there and + * information * is available in the COLORSPACE. (See + * png_colorspace_sync_info in png.c for where the valid flags get set.) + * + * Under certain circumstances the colorspace can be invalidated without + * syncing the info_struct 'valid' flags; this happens if libpng detects + * an error and calls png_error while the color space is being set, yet + * the application continues writing the PNG. So check the 'invalid' + * flag here too. + */ +#ifdef PNG_WRITE_APNG_SUPPORTED + if ((info_ptr->valid & PNG_INFO_acTL) != 0) + png_write_acTL(png_ptr, info_ptr->num_frames, info_ptr->num_plays); +#endif +#ifdef PNG_GAMMA_SUPPORTED +# ifdef PNG_WRITE_gAMA_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) != 0 && + (info_ptr->valid & PNG_INFO_gAMA) != 0) + png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma); +# endif +#endif + +#ifdef PNG_COLORSPACE_SUPPORTED + /* Write only one of sRGB or an ICC profile. If a profile was supplied + * and it matches one of the known sRGB ones issue a warning. + */ +# ifdef PNG_WRITE_iCCP_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->valid & PNG_INFO_iCCP) != 0) + { +# ifdef PNG_WRITE_sRGB_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sRGB) != 0) + png_app_warning(png_ptr, + "profile matches sRGB but writing iCCP instead"); +# endif + + png_write_iCCP(png_ptr, info_ptr->iccp_name, + info_ptr->iccp_profile); + } +# ifdef PNG_WRITE_sRGB_SUPPORTED + else +# endif +# endif + +# ifdef PNG_WRITE_sRGB_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->valid & PNG_INFO_sRGB) != 0) + png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent); +# endif /* WRITE_sRGB */ +#endif /* COLORSPACE */ + +#ifdef PNG_WRITE_sBIT_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sBIT) != 0) + png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type); +#endif + +#ifdef PNG_COLORSPACE_SUPPORTED +# ifdef PNG_WRITE_cHRM_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0 && + (info_ptr->valid & PNG_INFO_cHRM) != 0) + png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy); +# endif +#endif + +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR); +#endif + + png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE; + } +} + +void PNGAPI +png_write_info(png_structrp png_ptr, png_const_inforp info_ptr) +{ +#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) + int i; +#endif + + png_debug(1, "in png_write_info"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_write_info_before_PLTE(png_ptr, info_ptr); + + if ((info_ptr->valid & PNG_INFO_PLTE) != 0) + png_write_PLTE(png_ptr, info_ptr->palette, + (png_uint_32)info_ptr->num_palette); + + else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + png_error(png_ptr, "Valid palette required for paletted images"); + +#ifdef PNG_WRITE_tRNS_SUPPORTED + if ((info_ptr->valid & PNG_INFO_tRNS) !=0) + { +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED + /* Invert the alpha channel (in tRNS) */ + if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0 && + info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + int j, jend; + + jend = info_ptr->num_trans; + if (jend > PNG_MAX_PALETTE_LENGTH) + jend = PNG_MAX_PALETTE_LENGTH; + + for (j = 0; j<jend; ++j) + info_ptr->trans_alpha[j] = + (png_byte)(255 - info_ptr->trans_alpha[j]); + } +#endif + png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color), + info_ptr->num_trans, info_ptr->color_type); + } +#endif +#ifdef PNG_WRITE_bKGD_SUPPORTED + if ((info_ptr->valid & PNG_INFO_bKGD) != 0) + png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type); +#endif + +#ifdef PNG_WRITE_eXIf_SUPPORTED + if ((info_ptr->valid & PNG_INFO_eXIf) != 0) + png_write_eXIf(png_ptr, info_ptr->exif, info_ptr->num_exif); +#endif + +#ifdef PNG_WRITE_hIST_SUPPORTED + if ((info_ptr->valid & PNG_INFO_hIST) != 0) + png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette); +#endif + +#ifdef PNG_WRITE_oFFs_SUPPORTED + if ((info_ptr->valid & PNG_INFO_oFFs) != 0) + png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset, + info_ptr->offset_unit_type); +#endif + +#ifdef PNG_WRITE_pCAL_SUPPORTED + if ((info_ptr->valid & PNG_INFO_pCAL) != 0) + png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0, + info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams, + info_ptr->pcal_units, info_ptr->pcal_params); +#endif + +#ifdef PNG_WRITE_sCAL_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sCAL) != 0) + png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit, + info_ptr->scal_s_width, info_ptr->scal_s_height); +#endif /* sCAL */ + +#ifdef PNG_WRITE_pHYs_SUPPORTED + if ((info_ptr->valid & PNG_INFO_pHYs) != 0) + png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit, + info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type); +#endif /* pHYs */ + +#ifdef PNG_WRITE_tIME_SUPPORTED + if ((info_ptr->valid & PNG_INFO_tIME) != 0) + { + png_write_tIME(png_ptr, &(info_ptr->mod_time)); + png_ptr->mode |= PNG_WROTE_tIME; + } +#endif /* tIME */ + +#ifdef PNG_WRITE_sPLT_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sPLT) != 0) + for (i = 0; i < (int)info_ptr->splt_palettes_num; i++) + png_write_sPLT(png_ptr, info_ptr->splt_palettes + i); +#endif /* sPLT */ + +#ifdef PNG_WRITE_TEXT_SUPPORTED + /* Check to see if we need to write text chunks */ + for (i = 0; i < info_ptr->num_text; i++) + { + png_debug2(2, "Writing header text chunk %d, type %d", i, + info_ptr->text[i].compression); + /* An internationalized chunk? */ + if (info_ptr->text[i].compression > 0) + { +#ifdef PNG_WRITE_iTXt_SUPPORTED + /* Write international chunk */ + png_write_iTXt(png_ptr, + info_ptr->text[i].compression, + info_ptr->text[i].key, + info_ptr->text[i].lang, + info_ptr->text[i].lang_key, + info_ptr->text[i].text); + /* Mark this chunk as written */ + if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; + else + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; +#else + png_warning(png_ptr, "Unable to write international text"); +#endif + } + + /* If we want a compressed text chunk */ + else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt) + { +#ifdef PNG_WRITE_zTXt_SUPPORTED + /* Write compressed chunk */ + png_write_zTXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, info_ptr->text[i].compression); + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; +#else + png_warning(png_ptr, "Unable to write compressed text"); +#endif + } + + else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + { +#ifdef PNG_WRITE_tEXt_SUPPORTED + /* Write uncompressed chunk */ + png_write_tEXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, + 0); + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; +#else + /* Can't get here */ + png_warning(png_ptr, "Unable to write uncompressed text"); +#endif + } + } +#endif /* tEXt */ + +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE); +#endif +} + +/* Writes the end of the PNG file. If you don't want to write comments or + * time information, you can pass NULL for info. If you already wrote these + * in png_write_info(), do not write them again here. If you have long + * comments, I suggest writing them here, and compressing them. + */ +void PNGAPI +png_write_end(png_structrp png_ptr, png_inforp info_ptr) +{ + png_debug(1, "in png_write_end"); + + if (png_ptr == NULL) + return; + + if ((png_ptr->mode & PNG_HAVE_IDAT) == 0) + png_error(png_ptr, "No IDATs written into file"); + +#ifdef PNG_WRITE_APNG_SUPPORTED + if (png_ptr->num_frames_written != png_ptr->num_frames_to_write) + png_error(png_ptr, "Not enough frames written"); +#endif + +#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED + if (png_ptr->num_palette_max > png_ptr->num_palette) + png_benign_error(png_ptr, "Wrote palette index exceeding num_palette"); +#endif + + /* See if user wants us to write information chunks */ + if (info_ptr != NULL) + { +#ifdef PNG_WRITE_TEXT_SUPPORTED + int i; /* local index variable */ +#endif +#ifdef PNG_WRITE_tIME_SUPPORTED + /* Check to see if user has supplied a time chunk */ + if ((info_ptr->valid & PNG_INFO_tIME) != 0 && + (png_ptr->mode & PNG_WROTE_tIME) == 0) + png_write_tIME(png_ptr, &(info_ptr->mod_time)); + +#endif +#ifdef PNG_WRITE_TEXT_SUPPORTED + /* Loop through comment chunks */ + for (i = 0; i < info_ptr->num_text; i++) + { + png_debug2(2, "Writing trailer text chunk %d, type %d", i, + info_ptr->text[i].compression); + /* An internationalized chunk? */ + if (info_ptr->text[i].compression > 0) + { +#ifdef PNG_WRITE_iTXt_SUPPORTED + /* Write international chunk */ + png_write_iTXt(png_ptr, + info_ptr->text[i].compression, + info_ptr->text[i].key, + info_ptr->text[i].lang, + info_ptr->text[i].lang_key, + info_ptr->text[i].text); + /* Mark this chunk as written */ + if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; + else + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; +#else + png_warning(png_ptr, "Unable to write international text"); +#endif + } + + else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt) + { +#ifdef PNG_WRITE_zTXt_SUPPORTED + /* Write compressed chunk */ + png_write_zTXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, info_ptr->text[i].compression); + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; +#else + png_warning(png_ptr, "Unable to write compressed text"); +#endif + } + + else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + { +#ifdef PNG_WRITE_tEXt_SUPPORTED + /* Write uncompressed chunk */ + png_write_tEXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, 0); + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; +#else + png_warning(png_ptr, "Unable to write uncompressed text"); +#endif + } + } +#endif + +#ifdef PNG_WRITE_eXIf_SUPPORTED + if ((info_ptr->valid & PNG_INFO_eXIf) != 0) + png_write_eXIf(png_ptr, info_ptr->exif, info_ptr->num_exif); +#endif + +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT); +#endif + } + + png_ptr->mode |= PNG_AFTER_IDAT; + + /* Write end of PNG file */ + png_write_IEND(png_ptr); + + /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03, + * and restored again in libpng-1.2.30, may cause some applications that + * do not set png_ptr->output_flush_fn to crash. If your application + * experiences a problem, please try building libpng with + * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to + * png-mng-implement at lists.sf.net . + */ +#ifdef PNG_WRITE_FLUSH_SUPPORTED +# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED + png_flush(png_ptr); +# endif +#endif +} + +#ifdef PNG_CONVERT_tIME_SUPPORTED +void PNGAPI +png_convert_from_struct_tm(png_timep ptime, const struct tm * ttime) +{ + png_debug(1, "in png_convert_from_struct_tm"); + + ptime->year = (png_uint_16)(1900 + ttime->tm_year); + ptime->month = (png_byte)(ttime->tm_mon + 1); + ptime->day = (png_byte)ttime->tm_mday; + ptime->hour = (png_byte)ttime->tm_hour; + ptime->minute = (png_byte)ttime->tm_min; + ptime->second = (png_byte)ttime->tm_sec; +} + +void PNGAPI +png_convert_from_time_t(png_timep ptime, time_t ttime) +{ + struct tm *tbuf; + + png_debug(1, "in png_convert_from_time_t"); + + tbuf = gmtime(&ttime); + png_convert_from_struct_tm(ptime, tbuf); +} +#endif + +/* Initialize png_ptr structure, and allocate any memory needed */ +PNG_FUNCTION(png_structp,PNGAPI +png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED) +{ +#ifndef PNG_USER_MEM_SUPPORTED + png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, + error_fn, warn_fn, NULL, NULL, NULL); +#else + return png_create_write_struct_2(user_png_ver, error_ptr, error_fn, + warn_fn, NULL, NULL, NULL); +} + +/* Alternate initialize png_ptr structure, and allocate any memory needed */ +PNG_FUNCTION(png_structp,PNGAPI +png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, + png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) +{ + png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, + error_fn, warn_fn, mem_ptr, malloc_fn, free_fn); +#endif /* USER_MEM */ + if (png_ptr != NULL) + { + /* Set the zlib control values to defaults; they can be overridden by the + * application after the struct has been created. + */ + png_ptr->zbuffer_size = PNG_ZBUF_SIZE; + + /* The 'zlib_strategy' setting is irrelevant because png_default_claim in + * pngwutil.c defaults it according to whether or not filters will be + * used, and ignores this setting. + */ + png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY; + png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION; + png_ptr->zlib_mem_level = 8; + png_ptr->zlib_window_bits = 15; + png_ptr->zlib_method = 8; + +#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED + png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY; + png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION; + png_ptr->zlib_text_mem_level = 8; + png_ptr->zlib_text_window_bits = 15; + png_ptr->zlib_text_method = 8; +#endif /* WRITE_COMPRESSED_TEXT */ + + /* This is a highly dubious configuration option; by default it is off, + * but it may be appropriate for private builds that are testing + * extensions not conformant to the current specification, or of + * applications that must not fail to write at all costs! + */ +#ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED + /* In stable builds only warn if an application error can be completely + * handled. + */ + png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN; +#endif + + /* App warnings are warnings in release (or release candidate) builds but + * are errors during development. + */ +#if PNG_RELEASE_BUILD + png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN; +#endif + + /* TODO: delay this, it can be done in png_init_io() (if the app doesn't + * do it itself) avoiding setting the default function if it is not + * required. + */ + png_set_write_fn(png_ptr, NULL, NULL, NULL); + } + + return png_ptr; +} + + +/* Write a few rows of image data. If the image is interlaced, + * either you will have to write the 7 sub images, or, if you + * have called png_set_interlace_handling(), you will have to + * "write" the image seven times. + */ +void PNGAPI +png_write_rows(png_structrp png_ptr, png_bytepp row, + png_uint_32 num_rows) +{ + png_uint_32 i; /* row counter */ + png_bytepp rp; /* row pointer */ + + png_debug(1, "in png_write_rows"); + + if (png_ptr == NULL) + return; + + /* Loop through the rows */ + for (i = 0, rp = row; i < num_rows; i++, rp++) + { + png_write_row(png_ptr, *rp); + } +} + +/* Write the image. You only need to call this function once, even + * if you are writing an interlaced image. + */ +void PNGAPI +png_write_image(png_structrp png_ptr, png_bytepp image) +{ + png_uint_32 i; /* row index */ + int pass, num_pass; /* pass variables */ + png_bytepp rp; /* points to current row */ + + if (png_ptr == NULL) + return; + + png_debug(1, "in png_write_image"); + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Initialize interlace handling. If image is not interlaced, + * this will set pass to 1 + */ + num_pass = png_set_interlace_handling(png_ptr); +#else + num_pass = 1; +#endif + /* Loop through passes */ + for (pass = 0; pass < num_pass; pass++) + { + /* Loop through image */ + for (i = 0, rp = image; i < png_ptr->height; i++, rp++) + { + png_write_row(png_ptr, *rp); + } + } +} + +#ifdef PNG_MNG_FEATURES_SUPPORTED +/* Performs intrapixel differencing */ +static void +png_do_write_intrapixel(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_write_intrapixel"); + + if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + int bytes_per_pixel; + png_uint_32 row_width = row_info->width; + if (row_info->bit_depth == 8) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 3; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 4; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + *(rp) = (png_byte)(*rp - *(rp + 1)); + *(rp + 2) = (png_byte)(*(rp + 2) - *(rp + 1)); + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 6; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 8; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + png_uint_32 s0 = (png_uint_32)(*(rp ) << 8) | *(rp + 1); + png_uint_32 s1 = (png_uint_32)(*(rp + 2) << 8) | *(rp + 3); + png_uint_32 s2 = (png_uint_32)(*(rp + 4) << 8) | *(rp + 5); + png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL); + png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL); + *(rp ) = (png_byte)(red >> 8); + *(rp + 1) = (png_byte)red; + *(rp + 4) = (png_byte)(blue >> 8); + *(rp + 5) = (png_byte)blue; + } + } +#endif /* WRITE_16BIT */ + } +} +#endif /* MNG_FEATURES */ + +/* Called by user to write a row of image data */ +void PNGAPI +png_write_row(png_structrp png_ptr, png_const_bytep row) +{ + /* 1.5.6: moved from png_struct to be a local structure: */ + png_row_info row_info; + + if (png_ptr == NULL) + return; + + png_debug2(1, "in png_write_row (row %u, pass %d)", + png_ptr->row_number, png_ptr->pass); + + /* Initialize transformations and other stuff if first time */ + if (png_ptr->row_number == 0 && png_ptr->pass == 0) + { + /* Make sure we wrote the header info */ + if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0) + png_error(png_ptr, + "png_write_info was never called before png_write_row"); + + /* Check for transforms that have been set but were defined out */ +#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED) + if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) + png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED) + if ((png_ptr->transformations & PNG_FILLER) != 0) + png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined"); +#endif +#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \ + defined(PNG_READ_PACKSWAP_SUPPORTED) + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) + png_warning(png_ptr, + "PNG_WRITE_PACKSWAP_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED) + if ((png_ptr->transformations & PNG_PACK) != 0) + png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED) + if ((png_ptr->transformations & PNG_SHIFT) != 0) + png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED) + if ((png_ptr->transformations & PNG_BGR) != 0) + png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED) + if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) + png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined"); +#endif + + png_write_start_row(png_ptr); + } + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* If interlaced and not interested in row, return */ + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) != 0) + { + switch (png_ptr->pass) + { + case 0: + if ((png_ptr->row_number & 0x07) != 0) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 1: + if ((png_ptr->row_number & 0x07) != 0 || png_ptr->width < 5) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 2: + if ((png_ptr->row_number & 0x07) != 4) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 3: + if ((png_ptr->row_number & 0x03) != 0 || png_ptr->width < 3) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 4: + if ((png_ptr->row_number & 0x03) != 2) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 5: + if ((png_ptr->row_number & 0x01) != 0 || png_ptr->width < 2) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 6: + if ((png_ptr->row_number & 0x01) == 0) + { + png_write_finish_row(png_ptr); + return; + } + break; + + default: /* error: ignore it */ + break; + } + } +#endif + + /* Set up row info for transformations */ + row_info.color_type = png_ptr->color_type; + row_info.width = png_ptr->usr_width; + row_info.channels = png_ptr->usr_channels; + row_info.bit_depth = png_ptr->usr_bit_depth; + row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels); + row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); + + png_debug1(3, "row_info->color_type = %d", row_info.color_type); + png_debug1(3, "row_info->width = %u", row_info.width); + png_debug1(3, "row_info->channels = %d", row_info.channels); + png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth); + png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth); + png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes); + + /* Copy user's row into buffer, leaving room for filter byte. */ + memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes); + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Handle interlacing */ + if (png_ptr->interlaced && png_ptr->pass < 6 && + (png_ptr->transformations & PNG_INTERLACE) != 0) + { + png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass); + /* This should always get caught above, but still ... */ + if (row_info.width == 0) + { + png_write_finish_row(png_ptr); + return; + } + } +#endif + +#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED + /* Handle other transformations */ + if (png_ptr->transformations != 0) + png_do_write_transformations(png_ptr, &row_info); +#endif + + /* At this point the row_info pixel depth must match the 'transformed' depth, + * which is also the output depth. + */ + if (row_info.pixel_depth != png_ptr->pixel_depth || + row_info.pixel_depth != png_ptr->transformed_pixel_depth) + png_error(png_ptr, "internal write transform logic error"); + +#ifdef PNG_MNG_FEATURES_SUPPORTED + /* Write filter_method 64 (intrapixel differencing) only if + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and + * 2. Libpng did not write a PNG signature (this filter_method is only + * used in PNG datastreams that are embedded in MNG datastreams) and + * 3. The application called png_permit_mng_features with a mask that + * included PNG_FLAG_MNG_FILTER_64 and + * 4. The filter_method is 64 and + * 5. The color_type is RGB or RGBA + */ + if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && + (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) + { + /* Intrapixel differencing */ + png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1); + } +#endif + +/* Added at libpng-1.5.10 */ +#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Check for out-of-range palette index */ + if (row_info.color_type == PNG_COLOR_TYPE_PALETTE && + png_ptr->num_palette_max >= 0) + png_do_check_palette_indexes(png_ptr, &row_info); +#endif + + /* Find a filter if necessary, filter the row and write it out. */ + png_write_find_filter(png_ptr, &row_info); + + if (png_ptr->write_row_fn != NULL) + (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); +} + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +/* Set the automatic flush interval or 0 to turn flushing off */ +void PNGAPI +png_set_flush(png_structrp png_ptr, int nrows) +{ + png_debug(1, "in png_set_flush"); + + if (png_ptr == NULL) + return; + + png_ptr->flush_dist = (nrows < 0 ? 0 : (png_uint_32)nrows); +} + +/* Flush the current output buffers now */ +void PNGAPI +png_write_flush(png_structrp png_ptr) +{ + png_debug(1, "in png_write_flush"); + + if (png_ptr == NULL) + return; + + /* We have already written out all of the data */ + if (png_ptr->row_number >= png_ptr->num_rows) + return; + + png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH); + png_ptr->flush_rows = 0; + png_flush(png_ptr); +} +#endif /* WRITE_FLUSH */ + +/* Free any memory used in png_ptr struct without freeing the struct itself. */ +static void +png_write_destroy(png_structrp png_ptr) +{ + png_debug(1, "in png_write_destroy"); + + /* Free any memory zlib uses */ + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) + deflateEnd(&png_ptr->zstream); + + /* Free our memory. png_free checks NULL for us. */ + png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list); + png_free(png_ptr, png_ptr->row_buf); + png_ptr->row_buf = NULL; +#ifdef PNG_WRITE_FILTER_SUPPORTED + png_free(png_ptr, png_ptr->prev_row); + png_free(png_ptr, png_ptr->try_row); + png_free(png_ptr, png_ptr->tst_row); + png_ptr->prev_row = NULL; + png_ptr->try_row = NULL; + png_ptr->tst_row = NULL; +#endif + +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + png_free(png_ptr, png_ptr->chunk_list); + png_ptr->chunk_list = NULL; +#endif + + /* The error handling and memory handling information is left intact at this + * point: the jmp_buf may still have to be freed. See png_destroy_png_struct + * for how this happens. + */ +} + +/* Free all memory used by the write. + * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for + * *png_ptr_ptr. Prior to 1.6.0 it would accept such a value and it would free + * the passed in info_structs but it would quietly fail to free any of the data + * inside them. In 1.6.0 it quietly does nothing (it has to be quiet because it + * has no png_ptr.) + */ +void PNGAPI +png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr) +{ + png_debug(1, "in png_destroy_write_struct"); + + if (png_ptr_ptr != NULL) + { + png_structrp png_ptr = *png_ptr_ptr; + + if (png_ptr != NULL) /* added in libpng 1.6.0 */ + { + png_destroy_info_struct(png_ptr, info_ptr_ptr); + + *png_ptr_ptr = NULL; + png_write_destroy(png_ptr); + png_destroy_png_struct(png_ptr); + } + } +} + +/* Allow the application to select one or more row filters to use. */ +void PNGAPI +png_set_filter(png_structrp png_ptr, int method, int filters) +{ + png_debug(1, "in png_set_filter"); + + if (png_ptr == NULL) + return; + +#ifdef PNG_MNG_FEATURES_SUPPORTED + if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && + (method == PNG_INTRAPIXEL_DIFFERENCING)) + method = PNG_FILTER_TYPE_BASE; + +#endif + if (method == PNG_FILTER_TYPE_BASE) + { + switch (filters & (PNG_ALL_FILTERS | 0x07)) + { +#ifdef PNG_WRITE_FILTER_SUPPORTED + case 5: + case 6: + case 7: png_app_error(png_ptr, "Unknown row filter for method 0"); +#endif /* WRITE_FILTER */ + /* FALLTHROUGH */ + case PNG_FILTER_VALUE_NONE: + png_ptr->do_filter = PNG_FILTER_NONE; break; + +#ifdef PNG_WRITE_FILTER_SUPPORTED + case PNG_FILTER_VALUE_SUB: + png_ptr->do_filter = PNG_FILTER_SUB; break; + + case PNG_FILTER_VALUE_UP: + png_ptr->do_filter = PNG_FILTER_UP; break; + + case PNG_FILTER_VALUE_AVG: + png_ptr->do_filter = PNG_FILTER_AVG; break; + + case PNG_FILTER_VALUE_PAETH: + png_ptr->do_filter = PNG_FILTER_PAETH; break; + + default: + png_ptr->do_filter = (png_byte)filters; break; +#else + default: + png_app_error(png_ptr, "Unknown row filter for method 0"); +#endif /* WRITE_FILTER */ + } + +#ifdef PNG_WRITE_FILTER_SUPPORTED + /* If we have allocated the row_buf, this means we have already started + * with the image and we should have allocated all of the filter buffers + * that have been selected. If prev_row isn't already allocated, then + * it is too late to start using the filters that need it, since we + * will be missing the data in the previous row. If an application + * wants to start and stop using particular filters during compression, + * it should start out with all of the filters, and then remove them + * or add them back after the start of compression. + * + * NOTE: this is a nasty constraint on the code, because it means that the + * prev_row buffer must be maintained even if there are currently no + * 'prev_row' requiring filters active. + */ + if (png_ptr->row_buf != NULL) + { + int num_filters; + png_alloc_size_t buf_size; + + /* Repeat the checks in png_write_start_row; 1 pixel high or wide + * images cannot benefit from certain filters. If this isn't done here + * the check below will fire on 1 pixel high images. + */ + if (png_ptr->height == 1) + filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); + + if (png_ptr->width == 1) + filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH); + + if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0 + && png_ptr->prev_row == NULL) + { + /* This is the error case, however it is benign - the previous row + * is not available so the filter can't be used. Just warn here. + */ + png_app_warning(png_ptr, + "png_set_filter: UP/AVG/PAETH cannot be added after start"); + filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); + } + + num_filters = 0; + + if (filters & PNG_FILTER_SUB) + num_filters++; + + if (filters & PNG_FILTER_UP) + num_filters++; + + if (filters & PNG_FILTER_AVG) + num_filters++; + + if (filters & PNG_FILTER_PAETH) + num_filters++; + + /* Allocate needed row buffers if they have not already been + * allocated. + */ + buf_size = PNG_ROWBYTES(png_ptr->usr_channels * png_ptr->usr_bit_depth, + png_ptr->width) + 1; + + if (png_ptr->try_row == NULL) + png_ptr->try_row = png_voidcast(png_bytep, + png_malloc(png_ptr, buf_size)); + + if (num_filters > 1) + { + if (png_ptr->tst_row == NULL) + png_ptr->tst_row = png_voidcast(png_bytep, + png_malloc(png_ptr, buf_size)); + } + } + png_ptr->do_filter = (png_byte)filters; +#endif + } + else + png_error(png_ptr, "Unknown custom filter method"); +} + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ +/* Provide floating and fixed point APIs */ +#ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method, + int num_weights, png_const_doublep filter_weights, + png_const_doublep filter_costs) +{ + PNG_UNUSED(png_ptr) + PNG_UNUSED(heuristic_method) + PNG_UNUSED(num_weights) + PNG_UNUSED(filter_weights) + PNG_UNUSED(filter_costs) +} +#endif /* FLOATING_POINT */ + +#ifdef PNG_FIXED_POINT_SUPPORTED +void PNGAPI +png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method, + int num_weights, png_const_fixed_point_p filter_weights, + png_const_fixed_point_p filter_costs) +{ + PNG_UNUSED(png_ptr) + PNG_UNUSED(heuristic_method) + PNG_UNUSED(num_weights) + PNG_UNUSED(filter_weights) + PNG_UNUSED(filter_costs) +} +#endif /* FIXED_POINT */ +#endif /* WRITE_WEIGHTED_FILTER */ + +#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED +void PNGAPI +png_set_compression_level(png_structrp png_ptr, int level) +{ + png_debug(1, "in png_set_compression_level"); + + if (png_ptr == NULL) + return; + + png_ptr->zlib_level = level; +} + +void PNGAPI +png_set_compression_mem_level(png_structrp png_ptr, int mem_level) +{ + png_debug(1, "in png_set_compression_mem_level"); + + if (png_ptr == NULL) + return; + + png_ptr->zlib_mem_level = mem_level; +} + +void PNGAPI +png_set_compression_strategy(png_structrp png_ptr, int strategy) +{ + png_debug(1, "in png_set_compression_strategy"); + + if (png_ptr == NULL) + return; + + /* The flag setting here prevents the libpng dynamic selection of strategy. + */ + png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY; + png_ptr->zlib_strategy = strategy; +} + +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +void PNGAPI +png_set_compression_window_bits(png_structrp png_ptr, int window_bits) +{ + if (png_ptr == NULL) + return; + + /* Prior to 1.6.0 this would warn but then set the window_bits value. This + * meant that negative window bits values could be selected that would cause + * libpng to write a non-standard PNG file with raw deflate or gzip + * compressed IDAT or ancillary chunks. Such files can be read and there is + * no warning on read, so this seems like a very bad idea. + */ + if (window_bits > 15) + { + png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); + window_bits = 15; + } + + else if (window_bits < 8) + { + png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); + window_bits = 8; + } + + png_ptr->zlib_window_bits = window_bits; +} + +void PNGAPI +png_set_compression_method(png_structrp png_ptr, int method) +{ + png_debug(1, "in png_set_compression_method"); + + if (png_ptr == NULL) + return; + + /* This would produce an invalid PNG file if it worked, but it doesn't and + * deflate will fault it, so it is harmless to just warn here. + */ + if (method != 8) + png_warning(png_ptr, "Only compression method 8 is supported by PNG"); + + png_ptr->zlib_method = method; +} +#endif /* WRITE_CUSTOMIZE_COMPRESSION */ + +/* The following were added to libpng-1.5.4 */ +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED +void PNGAPI +png_set_text_compression_level(png_structrp png_ptr, int level) +{ + png_debug(1, "in png_set_text_compression_level"); + + if (png_ptr == NULL) + return; + + png_ptr->zlib_text_level = level; +} + +void PNGAPI +png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level) +{ + png_debug(1, "in png_set_text_compression_mem_level"); + + if (png_ptr == NULL) + return; + + png_ptr->zlib_text_mem_level = mem_level; +} + +void PNGAPI +png_set_text_compression_strategy(png_structrp png_ptr, int strategy) +{ + png_debug(1, "in png_set_text_compression_strategy"); + + if (png_ptr == NULL) + return; + + png_ptr->zlib_text_strategy = strategy; +} + +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +void PNGAPI +png_set_text_compression_window_bits(png_structrp png_ptr, int window_bits) +{ + if (png_ptr == NULL) + return; + + if (window_bits > 15) + { + png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); + window_bits = 15; + } + + else if (window_bits < 8) + { + png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); + window_bits = 8; + } + + png_ptr->zlib_text_window_bits = window_bits; +} + +void PNGAPI +png_set_text_compression_method(png_structrp png_ptr, int method) +{ + png_debug(1, "in png_set_text_compression_method"); + + if (png_ptr == NULL) + return; + + if (method != 8) + png_warning(png_ptr, "Only compression method 8 is supported by PNG"); + + png_ptr->zlib_text_method = method; +} +#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ +/* end of API added to libpng-1.5.4 */ + +void PNGAPI +png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->write_row_fn = write_row_fn; +} + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED +void PNGAPI +png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr + write_user_transform_fn) +{ + png_debug(1, "in png_set_write_user_transform_fn"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_USER_TRANSFORM; + png_ptr->write_user_transform_fn = write_user_transform_fn; +} +#endif + + +#ifdef PNG_INFO_IMAGE_SUPPORTED +void PNGAPI +png_write_png(png_structrp png_ptr, png_inforp info_ptr, + int transforms, voidp params) +{ + if (png_ptr == NULL || info_ptr == NULL) + return; + + if ((info_ptr->valid & PNG_INFO_IDAT) == 0) + { + png_app_error(png_ptr, "no rows for png_write_image to write"); + return; + } + + /* Write the file header information. */ + png_write_info(png_ptr, info_ptr); + + /* ------ these transformations don't touch the info structure ------- */ + + /* Invert monochrome pixels */ + if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0) +#ifdef PNG_WRITE_INVERT_SUPPORTED + png_set_invert_mono(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported"); +#endif + + /* Shift the pixels up to a legal bit depth and fill in + * as appropriate to correctly scale the image. + */ + if ((transforms & PNG_TRANSFORM_SHIFT) != 0) +#ifdef PNG_WRITE_SHIFT_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sBIT) != 0) + png_set_shift(png_ptr, &info_ptr->sig_bit); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported"); +#endif + + /* Pack pixels into bytes */ + if ((transforms & PNG_TRANSFORM_PACKING) != 0) +#ifdef PNG_WRITE_PACK_SUPPORTED + png_set_packing(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported"); +#endif + + /* Swap location of alpha bytes from ARGB to RGBA */ + if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0) +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED + png_set_swap_alpha(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported"); +#endif + + /* Remove a filler (X) from XRGB/RGBX/AG/GA into to convert it into + * RGB, note that the code expects the input color type to be G or RGB; no + * alpha channel. + */ + if ((transforms & (PNG_TRANSFORM_STRIP_FILLER_AFTER| + PNG_TRANSFORM_STRIP_FILLER_BEFORE)) != 0) + { +#ifdef PNG_WRITE_FILLER_SUPPORTED + if ((transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) != 0) + { + if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) + png_app_error(png_ptr, + "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported"); + + /* Continue if ignored - this is the pre-1.6.10 behavior */ + png_set_filler(png_ptr, 0, PNG_FILLER_AFTER); + } + + else if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) + png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported"); +#endif + } + + /* Flip BGR pixels to RGB */ + if ((transforms & PNG_TRANSFORM_BGR) != 0) +#ifdef PNG_WRITE_BGR_SUPPORTED + png_set_bgr(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported"); +#endif + + /* Swap bytes of 16-bit files to most significant byte first */ + if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0) +#ifdef PNG_WRITE_SWAP_SUPPORTED + png_set_swap(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported"); +#endif + + /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats */ + if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0) +#ifdef PNG_WRITE_PACKSWAP_SUPPORTED + png_set_packswap(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported"); +#endif + + /* Invert the alpha channel from opacity to transparency */ + if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0) +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED + png_set_invert_alpha(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported"); +#endif + + /* ----------------------- end of transformations ------------------- */ + + /* Write the bits */ + png_write_image(png_ptr, info_ptr->row_pointers); + + /* It is REQUIRED to call this to finish writing the rest of the file */ + png_write_end(png_ptr, info_ptr); + + PNG_UNUSED(params) +} +#endif + + +#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED +/* Initialize the write structure - general purpose utility. */ +static int +png_image_write_init(png_imagep image) +{ + png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image, + png_safe_error, png_safe_warning); + + if (png_ptr != NULL) + { + png_infop info_ptr = png_create_info_struct(png_ptr); + + if (info_ptr != NULL) + { + png_controlp control = png_voidcast(png_controlp, + png_malloc_warn(png_ptr, (sizeof *control))); + + if (control != NULL) + { + memset(control, 0, (sizeof *control)); + + control->png_ptr = png_ptr; + control->info_ptr = info_ptr; + control->for_write = 1; + + image->opaque = control; + return 1; + } + + /* Error clean up */ + png_destroy_info_struct(png_ptr, &info_ptr); + } + + png_destroy_write_struct(&png_ptr, NULL); + } + + return png_image_error(image, "png_image_write_: out of memory"); +} + +/* Arguments to png_image_write_main: */ +typedef struct +{ + /* Arguments: */ + png_imagep image; + png_const_voidp buffer; + png_int_32 row_stride; + png_const_voidp colormap; + int convert_to_8bit; + /* Local variables: */ + png_const_voidp first_row; + ptrdiff_t row_bytes; + png_voidp local_row; + /* Byte count for memory writing */ + png_bytep memory; + png_alloc_size_t memory_bytes; /* not used for STDIO */ + png_alloc_size_t output_bytes; /* running total */ +} png_image_write_control; + +/* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to + * do any necessary byte swapping. The component order is defined by the + * png_image format value. + */ +static int +png_write_image_16bit(png_voidp argument) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + + png_const_uint_16p input_row = png_voidcast(png_const_uint_16p, + display->first_row); + png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row); + png_uint_16p row_end; + unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? + 3 : 1; + int aindex = 0; + png_uint_32 y = image->height; + + if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) + { +# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED + if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) + { + aindex = -1; + ++input_row; /* To point to the first component */ + ++output_row; + } + else + aindex = (int)channels; +# else + aindex = (int)channels; +# endif + } + + else + png_error(png_ptr, "png_write_image: internal call error"); + + /* Work out the output row end and count over this, note that the increment + * above to 'row' means that row_end can actually be beyond the end of the + * row; this is correct. + */ + row_end = output_row + image->width * (channels+1); + + for (; y > 0; --y) + { + png_const_uint_16p in_ptr = input_row; + png_uint_16p out_ptr = output_row; + + while (out_ptr < row_end) + { + png_uint_16 alpha = in_ptr[aindex]; + png_uint_32 reciprocal = 0; + int c; + + out_ptr[aindex] = alpha; + + /* Calculate a reciprocal. The correct calculation is simply + * component/alpha*65535 << 15. (I.e. 15 bits of precision); this + * allows correct rounding by adding .5 before the shift. 'reciprocal' + * is only initialized when required. + */ + if (alpha > 0 && alpha < 65535) + reciprocal = ((0xffff<<15)+(alpha>>1))/alpha; + + c = (int)channels; + do /* always at least one channel */ + { + png_uint_16 component = *in_ptr++; + + /* The following gives 65535 for an alpha of 0, which is fine, + * otherwise if 0/0 is represented as some other value there is more + * likely to be a discontinuity which will probably damage + * compression when moving from a fully transparent area to a + * nearly transparent one. (The assumption here is that opaque + * areas tend not to be 0 intensity.) + */ + if (component >= alpha) + component = 65535; + + /* component<alpha, so component/alpha is less than one and + * component*reciprocal is less than 2^31. + */ + else if (component > 0 && alpha < 65535) + { + png_uint_32 calc = component * reciprocal; + calc += 16384; /* round to nearest */ + component = (png_uint_16)(calc >> 15); + } + + *out_ptr++ = component; + } + while (--c > 0); + + /* Skip to next component (skip the intervening alpha channel) */ + ++in_ptr; + ++out_ptr; + } + + png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row)); + input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16)); + } + + return 1; +} + +/* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel + * is present it must be removed from the components, the components are then + * written in sRGB encoding. No components are added or removed. + * + * Calculate an alpha reciprocal to reverse pre-multiplication. As above the + * calculation can be done to 15 bits of accuracy; however, the output needs to + * be scaled in the range 0..255*65535, so include that scaling here. + */ +# define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+((alpha)>>1))/(alpha)) + +static png_byte +png_unpremultiply(png_uint_32 component, png_uint_32 alpha, + png_uint_32 reciprocal/*from the above macro*/) +{ + /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0 + * is represented as some other value there is more likely to be a + * discontinuity which will probably damage compression when moving from a + * fully transparent area to a nearly transparent one. (The assumption here + * is that opaque areas tend not to be 0 intensity.) + * + * There is a rounding problem here; if alpha is less than 128 it will end up + * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the + * output change for this too. + */ + if (component >= alpha || alpha < 128) + return 255; + + /* component<alpha, so component/alpha is less than one and + * component*reciprocal is less than 2^31. + */ + else if (component > 0) + { + /* The test is that alpha/257 (rounded) is less than 255, the first value + * that becomes 255 is 65407. + * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore, + * be exact!) [Could also test reciprocal != 0] + */ + if (alpha < 65407) + { + component *= reciprocal; + component += 64; /* round to nearest */ + component >>= 7; + } + + else + component *= 255; + + /* Convert the component to sRGB. */ + return (png_byte)PNG_sRGB_FROM_LINEAR(component); + } + + else + return 0; +} + +static int +png_write_image_8bit(png_voidp argument) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + + png_const_uint_16p input_row = png_voidcast(png_const_uint_16p, + display->first_row); + png_bytep output_row = png_voidcast(png_bytep, display->local_row); + png_uint_32 y = image->height; + unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? + 3 : 1; + + if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + png_bytep row_end; + int aindex; + +# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED + if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) + { + aindex = -1; + ++input_row; /* To point to the first component */ + ++output_row; + } + + else +# endif + aindex = (int)channels; + + /* Use row_end in place of a loop counter: */ + row_end = output_row + image->width * (channels+1); + + for (; y > 0; --y) + { + png_const_uint_16p in_ptr = input_row; + png_bytep out_ptr = output_row; + + while (out_ptr < row_end) + { + png_uint_16 alpha = in_ptr[aindex]; + png_byte alphabyte = (png_byte)PNG_DIV257(alpha); + png_uint_32 reciprocal = 0; + int c; + + /* Scale and write the alpha channel. */ + out_ptr[aindex] = alphabyte; + + if (alphabyte > 0 && alphabyte < 255) + reciprocal = UNP_RECIPROCAL(alpha); + + c = (int)channels; + do /* always at least one channel */ + *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal); + while (--c > 0); + + /* Skip to next component (skip the intervening alpha channel) */ + ++in_ptr; + ++out_ptr; + } /* while out_ptr < row_end */ + + png_write_row(png_ptr, png_voidcast(png_const_bytep, + display->local_row)); + input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16)); + } /* while y */ + } + + else + { + /* No alpha channel, so the row_end really is the end of the row and it + * is sufficient to loop over the components one by one. + */ + png_bytep row_end = output_row + image->width * channels; + + for (; y > 0; --y) + { + png_const_uint_16p in_ptr = input_row; + png_bytep out_ptr = output_row; + + while (out_ptr < row_end) + { + png_uint_32 component = *in_ptr++; + + component *= 255; + *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component); + } + + png_write_row(png_ptr, output_row); + input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16)); + } + } + + return 1; +} + +static void +png_image_set_PLTE(png_image_write_control *display) +{ + png_imagep image = display->image; + const void *cmap = display->colormap; + int entries = image->colormap_entries > 256 ? 256 : + (int)image->colormap_entries; + + /* NOTE: the caller must check for cmap != NULL and entries != 0 */ + png_uint_32 format = image->format; + unsigned int channels = PNG_IMAGE_SAMPLE_CHANNELS(format); + +# if defined(PNG_FORMAT_BGR_SUPPORTED) &&\ + defined(PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED) + int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 && + (format & PNG_FORMAT_FLAG_ALPHA) != 0; +# else +# define afirst 0 +# endif + +# ifdef PNG_FORMAT_BGR_SUPPORTED + int bgr = (format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0; +# else +# define bgr 0 +# endif + + int i, num_trans; + png_color palette[256]; + png_byte tRNS[256]; + + memset(tRNS, 255, (sizeof tRNS)); + memset(palette, 0, (sizeof palette)); + + for (i=num_trans=0; i<entries; ++i) + { + /* This gets automatically converted to sRGB with reversal of the + * pre-multiplication if the color-map has an alpha channel. + */ + if ((format & PNG_FORMAT_FLAG_LINEAR) != 0) + { + png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap); + + entry += (unsigned int)i * channels; + + if ((channels & 1) != 0) /* no alpha */ + { + if (channels >= 3) /* RGB */ + { + palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 * + entry[(2 ^ bgr)]); + palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 * + entry[1]); + palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 * + entry[bgr]); + } + + else /* Gray */ + palette[i].blue = palette[i].red = palette[i].green = + (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry); + } + + else /* alpha */ + { + png_uint_16 alpha = entry[afirst ? 0 : channels-1]; + png_byte alphabyte = (png_byte)PNG_DIV257(alpha); + png_uint_32 reciprocal = 0; + + /* Calculate a reciprocal, as in the png_write_image_8bit code above + * this is designed to produce a value scaled to 255*65535 when + * divided by 128 (i.e. asr 7). + */ + if (alphabyte > 0 && alphabyte < 255) + reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha; + + tRNS[i] = alphabyte; + if (alphabyte < 255) + num_trans = i+1; + + if (channels >= 3) /* RGB */ + { + palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)], + alpha, reciprocal); + palette[i].green = png_unpremultiply(entry[afirst + 1], alpha, + reciprocal); + palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha, + reciprocal); + } + + else /* gray */ + palette[i].blue = palette[i].red = palette[i].green = + png_unpremultiply(entry[afirst], alpha, reciprocal); + } + } + + else /* Color-map has sRGB values */ + { + png_const_bytep entry = png_voidcast(png_const_bytep, cmap); + + entry += (unsigned int)i * channels; + + switch (channels) + { + case 4: + tRNS[i] = entry[afirst ? 0 : 3]; + if (tRNS[i] < 255) + num_trans = i+1; + /* FALLTHROUGH */ + case 3: + palette[i].blue = entry[afirst + (2 ^ bgr)]; + palette[i].green = entry[afirst + 1]; + palette[i].red = entry[afirst + bgr]; + break; + + case 2: + tRNS[i] = entry[1 ^ afirst]; + if (tRNS[i] < 255) + num_trans = i+1; + /* FALLTHROUGH */ + case 1: + palette[i].blue = palette[i].red = palette[i].green = + entry[afirst]; + break; + + default: + break; + } + } + } + +# ifdef afirst +# undef afirst +# endif +# ifdef bgr +# undef bgr +# endif + + png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette, + entries); + + if (num_trans > 0) + png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS, + num_trans, NULL); + + image->colormap_entries = (png_uint_32)entries; +} + +static int +png_image_write_main(png_voidp argument) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + png_inforp info_ptr = image->opaque->info_ptr; + png_uint_32 format = image->format; + + /* The following four ints are actually booleans */ + int colormap = (format & PNG_FORMAT_FLAG_COLORMAP); + int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR); /* input */ + int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA); + int write_16bit = linear && (display->convert_to_8bit == 0); + +# ifdef PNG_BENIGN_ERRORS_SUPPORTED + /* Make sure we error out on any bad situation */ + png_set_benign_errors(png_ptr, 0/*error*/); +# endif + + /* Default the 'row_stride' parameter if required, also check the row stride + * and total image size to ensure that they are within the system limits. + */ + { + unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format); + + if (image->width <= 0x7fffffffU/channels) /* no overflow */ + { + png_uint_32 check; + png_uint_32 png_row_stride = image->width * channels; + + if (display->row_stride == 0) + display->row_stride = (png_int_32)/*SAFE*/png_row_stride; + + if (display->row_stride < 0) + check = (png_uint_32)(-display->row_stride); + + else + check = (png_uint_32)display->row_stride; + + if (check >= png_row_stride) + { + /* Now check for overflow of the image buffer calculation; this + * limits the whole image size to 32 bits for API compatibility with + * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro. + */ + if (image->height > 0xffffffffU/png_row_stride) + png_error(image->opaque->png_ptr, "memory image too large"); + } + + else + png_error(image->opaque->png_ptr, "supplied row stride too small"); + } + + else + png_error(image->opaque->png_ptr, "image row stride too large"); + } + + /* Set the required transforms then write the rows in the correct order. */ + if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0) + { + if (display->colormap != NULL && image->colormap_entries > 0) + { + png_uint_32 entries = image->colormap_entries; + + png_set_IHDR(png_ptr, info_ptr, image->width, image->height, + entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)), + PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE, + PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + png_image_set_PLTE(display); + } + + else + png_error(image->opaque->png_ptr, + "no color-map for color-mapped image"); + } + + else + png_set_IHDR(png_ptr, info_ptr, image->width, image->height, + write_16bit ? 16 : 8, + ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) + + ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0), + PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + /* Counter-intuitively the data transformations must be called *after* + * png_write_info, not before as in the read code, but the 'set' functions + * must still be called before. Just set the color space information, never + * write an interlaced image. + */ + + if (write_16bit != 0) + { + /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */ + png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR); + + if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0) + png_set_cHRM_fixed(png_ptr, info_ptr, + /* color x y */ + /* white */ 31270, 32900, + /* red */ 64000, 33000, + /* green */ 30000, 60000, + /* blue */ 15000, 6000 + ); + } + + else if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0) + png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL); + + /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit + * space must still be gamma encoded. + */ + else + png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE); + + /* Write the file header. */ + png_write_info(png_ptr, info_ptr); + + /* Now set up the data transformations (*after* the header is written), + * remove the handled transformations from the 'format' flags for checking. + * + * First check for a little endian system if writing 16-bit files. + */ + if (write_16bit != 0) + { + png_uint_16 le = 0x0001; + + if ((*(png_const_bytep) & le) != 0) + png_set_swap(png_ptr); + } + +# ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED + if ((format & PNG_FORMAT_FLAG_BGR) != 0) + { + if (colormap == 0 && (format & PNG_FORMAT_FLAG_COLOR) != 0) + png_set_bgr(png_ptr); + format &= ~PNG_FORMAT_FLAG_BGR; + } +# endif + +# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED + if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) + { + if (colormap == 0 && (format & PNG_FORMAT_FLAG_ALPHA) != 0) + png_set_swap_alpha(png_ptr); + format &= ~PNG_FORMAT_FLAG_AFIRST; + } +# endif + + /* If there are 16 or fewer color-map entries we wrote a lower bit depth + * above, but the application data is still byte packed. + */ + if (colormap != 0 && image->colormap_entries <= 16) + png_set_packing(png_ptr); + + /* That should have handled all (both) the transforms. */ + if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR | + PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0) + png_error(png_ptr, "png_write_image: unsupported transformation"); + + { + png_const_bytep row = png_voidcast(png_const_bytep, display->buffer); + ptrdiff_t row_bytes = display->row_stride; + + if (linear != 0) + row_bytes *= (sizeof (png_uint_16)); + + if (row_bytes < 0) + row += (image->height-1) * (-row_bytes); + + display->first_row = row; + display->row_bytes = row_bytes; + } + + /* Apply 'fast' options if the flag is set. */ + if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0) + { + png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS); + /* NOTE: determined by experiment using pngstest, this reflects some + * balance between the time to write the image once and the time to read + * it about 50 times. The speed-up in pngstest was about 10-20% of the + * total (user) time on a heavily loaded system. + */ +# ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED + png_set_compression_level(png_ptr, 3); +# endif + } + + /* Check for the cases that currently require a pre-transform on the row + * before it is written. This only applies when the input is 16-bit and + * either there is an alpha channel or it is converted to 8-bit. + */ + if ((linear != 0 && alpha != 0 ) || + (colormap == 0 && display->convert_to_8bit != 0)) + { + png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr, + png_get_rowbytes(png_ptr, info_ptr))); + int result; + + display->local_row = row; + if (write_16bit != 0) + result = png_safe_execute(image, png_write_image_16bit, display); + else + result = png_safe_execute(image, png_write_image_8bit, display); + display->local_row = NULL; + + png_free(png_ptr, row); + + /* Skip the 'write_end' on error: */ + if (result == 0) + return 0; + } + + /* Otherwise this is the case where the input is in a format currently + * supported by the rest of the libpng write code; call it directly. + */ + else + { + png_const_bytep row = png_voidcast(png_const_bytep, display->first_row); + ptrdiff_t row_bytes = display->row_bytes; + png_uint_32 y = image->height; + + for (; y > 0; --y) + { + png_write_row(png_ptr, row); + row += row_bytes; + } + } + + png_write_end(png_ptr, info_ptr); + return 1; +} + + +static void (PNGCBAPI +image_memory_write)(png_structp png_ptr, png_bytep/*const*/ data, size_t size) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + png_ptr->io_ptr/*backdoor: png_get_io_ptr(png_ptr)*/); + png_alloc_size_t ob = display->output_bytes; + + /* Check for overflow; this should never happen: */ + if (size <= ((png_alloc_size_t)-1) - ob) + { + /* I don't think libpng ever does this, but just in case: */ + if (size > 0) + { + if (display->memory_bytes >= ob+size) /* writing */ + memcpy(display->memory+ob, data, size); + + /* Always update the size: */ + display->output_bytes = ob+size; + } + } + + else + png_error(png_ptr, "png_image_write_to_memory: PNG too big"); +} + +static void (PNGCBAPI +image_memory_flush)(png_structp png_ptr) +{ + PNG_UNUSED(png_ptr) +} + +static int +png_image_write_memory(png_voidp argument) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + argument); + + /* The rest of the memory-specific init and write_main in an error protected + * environment. This case needs to use callbacks for the write operations + * since libpng has no built in support for writing to memory. + */ + png_set_write_fn(display->image->opaque->png_ptr, display/*io_ptr*/, + image_memory_write, image_memory_flush); + + return png_image_write_main(display); +} + +int PNGAPI +png_image_write_to_memory(png_imagep image, void *memory, + png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8bit, + const void *buffer, png_int_32 row_stride, const void *colormap) +{ + /* Write the image to the given buffer, or count the bytes if it is NULL */ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (memory_bytes != NULL && buffer != NULL) + { + /* This is to give the caller an easier error detection in the NULL + * case and guard against uninitialized variable problems: + */ + if (memory == NULL) + *memory_bytes = 0; + + if (png_image_write_init(image) != 0) + { + png_image_write_control display; + int result; + + memset(&display, 0, (sizeof display)); + display.image = image; + display.buffer = buffer; + display.row_stride = row_stride; + display.colormap = colormap; + display.convert_to_8bit = convert_to_8bit; + display.memory = png_voidcast(png_bytep, memory); + display.memory_bytes = *memory_bytes; + display.output_bytes = 0; + + result = png_safe_execute(image, png_image_write_memory, &display); + png_image_free(image); + + /* write_memory returns true even if we ran out of buffer. */ + if (result) + { + /* On out-of-buffer this function returns '0' but still updates + * memory_bytes: + */ + if (memory != NULL && display.output_bytes > *memory_bytes) + result = 0; + + *memory_bytes = display.output_bytes; + } + + return result; + } + + else + return 0; + } + + else + return png_image_error(image, + "png_image_write_to_memory: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_write_to_memory: incorrect PNG_IMAGE_VERSION"); + + else + return 0; +} + +#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED +int PNGAPI +png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit, + const void *buffer, png_int_32 row_stride, const void *colormap) +{ + /* Write the image to the given (FILE*). */ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (file != NULL && buffer != NULL) + { + if (png_image_write_init(image) != 0) + { + png_image_write_control display; + int result; + + /* This is slightly evil, but png_init_io doesn't do anything other + * than this and we haven't changed the standard IO functions so + * this saves a 'safe' function. + */ + image->opaque->png_ptr->io_ptr = file; + + memset(&display, 0, (sizeof display)); + display.image = image; + display.buffer = buffer; + display.row_stride = row_stride; + display.colormap = colormap; + display.convert_to_8bit = convert_to_8bit; + + result = png_safe_execute(image, png_image_write_main, &display); + png_image_free(image); + return result; + } + + else + return 0; + } + + else + return png_image_error(image, + "png_image_write_to_stdio: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION"); + + else + return 0; +} + +int PNGAPI +png_image_write_to_file(png_imagep image, const char *file_name, + int convert_to_8bit, const void *buffer, png_int_32 row_stride, + const void *colormap) +{ + /* Write the image to the named file. */ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (file_name != NULL && buffer != NULL) + { + FILE *fp = fopen(file_name, "wb"); + + if (fp != NULL) + { + if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer, + row_stride, colormap) != 0) + { + int error; /* from fflush/fclose */ + + /* Make sure the file is flushed correctly. */ + if (fflush(fp) == 0 && ferror(fp) == 0) + { + if (fclose(fp) == 0) + return 1; + + error = errno; /* from fclose */ + } + + else + { + error = errno; /* from fflush or ferror */ + (void)fclose(fp); + } + + (void)remove(file_name); + /* The image has already been cleaned up; this is just used to + * set the error (because the original write succeeded). + */ + return png_image_error(image, strerror(error)); + } + + else + { + /* Clean up: just the opened file. */ + (void)fclose(fp); + (void)remove(file_name); + return 0; + } + } + + else + return png_image_error(image, strerror(errno)); + } + + else + return png_image_error(image, + "png_image_write_to_file: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_write_to_file: incorrect PNG_IMAGE_VERSION"); + + else + return 0; +} +#endif /* SIMPLIFIED_WRITE_STDIO */ +#endif /* SIMPLIFIED_WRITE */ + +#ifdef PNG_WRITE_APNG_SUPPORTED +void PNGAPI +png_write_frame_head(png_structp png_ptr, png_infop info_ptr, + png_bytepp row_pointers, png_uint_32 width, png_uint_32 height, + png_uint_32 x_offset, png_uint_32 y_offset, + png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, + png_byte blend_op) +{ + png_debug(1, "in png_write_frame_head"); + + /* there is a chance this has been set after png_write_info was called, + * so it would be set but not written. is there a way to be sure? */ + if ((info_ptr->valid & PNG_INFO_acTL) == 0) + png_error(png_ptr, "png_write_frame_head(): acTL not set"); + + png_write_reset(png_ptr); + + png_write_reinit(png_ptr, info_ptr, width, height); + + if ((png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN) == 0 || + png_ptr->num_frames_written != 0) + png_write_fcTL(png_ptr, width, height, x_offset, y_offset, + delay_num, delay_den, dispose_op, blend_op); + + PNG_UNUSED(row_pointers) +} + +void PNGAPI +png_write_frame_tail(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_write_frame_tail"); + + png_ptr->num_frames_written++; + + PNG_UNUSED(info_ptr) +} +#endif /* WRITE_APNG */ +#endif /* WRITE */ diff --git a/media/libpng/pngwtran.c b/media/libpng/pngwtran.c new file mode 100644 index 0000000000..49a13c1e98 --- /dev/null +++ b/media/libpng/pngwtran.c @@ -0,0 +1,575 @@ + +/* pngwtran.c - transforms the data in a row for PNG writers + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#ifdef PNG_WRITE_SUPPORTED +#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED + +#ifdef PNG_WRITE_PACK_SUPPORTED +/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The + * row_info bit depth should be 8 (one pixel per byte). The channels + * should be 1 (this only happens on grayscale and paletted images). + */ +static void +png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth) +{ + png_debug(1, "in png_do_pack"); + + if (row_info->bit_depth == 8 && + row_info->channels == 1) + { + switch ((int)bit_depth) + { + case 1: + { + png_bytep sp, dp; + int mask, v; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + sp = row; + dp = row; + mask = 0x80; + v = 0; + + for (i = 0; i < row_width; i++) + { + if (*sp != 0) + v |= mask; + + sp++; + + if (mask > 1) + mask >>= 1; + + else + { + mask = 0x80; + *dp = (png_byte)v; + dp++; + v = 0; + } + } + + if (mask != 0x80) + *dp = (png_byte)v; + + break; + } + + case 2: + { + png_bytep sp, dp; + unsigned int shift; + int v; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + sp = row; + dp = row; + shift = 6; + v = 0; + + for (i = 0; i < row_width; i++) + { + png_byte value; + + value = (png_byte)(*sp & 0x03); + v |= (value << shift); + + if (shift == 0) + { + shift = 6; + *dp = (png_byte)v; + dp++; + v = 0; + } + + else + shift -= 2; + + sp++; + } + + if (shift != 6) + *dp = (png_byte)v; + + break; + } + + case 4: + { + png_bytep sp, dp; + unsigned int shift; + int v; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + sp = row; + dp = row; + shift = 4; + v = 0; + + for (i = 0; i < row_width; i++) + { + png_byte value; + + value = (png_byte)(*sp & 0x0f); + v |= (value << shift); + + if (shift == 0) + { + shift = 4; + *dp = (png_byte)v; + dp++; + v = 0; + } + + else + shift -= 4; + + sp++; + } + + if (shift != 4) + *dp = (png_byte)v; + + break; + } + + default: + break; + } + + row_info->bit_depth = (png_byte)bit_depth; + row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, + row_info->width); + } +} +#endif + +#ifdef PNG_WRITE_SHIFT_SUPPORTED +/* Shift pixel values to take advantage of whole range. Pass the + * true number of bits in bit_depth. The row should be packed + * according to row_info->bit_depth. Thus, if you had a row of + * bit depth 4, but the pixels only had values from 0 to 7, you + * would pass 3 as bit_depth, and this routine would translate the + * data to 0 to 15. + */ +static void +png_do_shift(png_row_infop row_info, png_bytep row, + png_const_color_8p bit_depth) +{ + png_debug(1, "in png_do_shift"); + + if (row_info->color_type != PNG_COLOR_TYPE_PALETTE) + { + int shift_start[4], shift_dec[4]; + unsigned int channels = 0; + + if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + shift_start[channels] = row_info->bit_depth - bit_depth->red; + shift_dec[channels] = bit_depth->red; + channels++; + + shift_start[channels] = row_info->bit_depth - bit_depth->green; + shift_dec[channels] = bit_depth->green; + channels++; + + shift_start[channels] = row_info->bit_depth - bit_depth->blue; + shift_dec[channels] = bit_depth->blue; + channels++; + } + + else + { + shift_start[channels] = row_info->bit_depth - bit_depth->gray; + shift_dec[channels] = bit_depth->gray; + channels++; + } + + if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0) + { + shift_start[channels] = row_info->bit_depth - bit_depth->alpha; + shift_dec[channels] = bit_depth->alpha; + channels++; + } + + /* With low row depths, could only be grayscale, so one channel */ + if (row_info->bit_depth < 8) + { + png_bytep bp = row; + size_t i; + unsigned int mask; + size_t row_bytes = row_info->rowbytes; + + if (bit_depth->gray == 1 && row_info->bit_depth == 2) + mask = 0x55; + + else if (row_info->bit_depth == 4 && bit_depth->gray == 3) + mask = 0x11; + + else + mask = 0xff; + + for (i = 0; i < row_bytes; i++, bp++) + { + int j; + unsigned int v, out; + + v = *bp; + out = 0; + + for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0]) + { + if (j > 0) + out |= v << j; + + else + out |= (v >> (-j)) & mask; + } + + *bp = (png_byte)(out & 0xff); + } + } + + else if (row_info->bit_depth == 8) + { + png_bytep bp = row; + png_uint_32 i; + png_uint_32 istop = channels * row_info->width; + + for (i = 0; i < istop; i++, bp++) + { + unsigned int c = i%channels; + int j; + unsigned int v, out; + + v = *bp; + out = 0; + + for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) + { + if (j > 0) + out |= v << j; + + else + out |= v >> (-j); + } + + *bp = (png_byte)(out & 0xff); + } + } + + else + { + png_bytep bp; + png_uint_32 i; + png_uint_32 istop = channels * row_info->width; + + for (bp = row, i = 0; i < istop; i++) + { + unsigned int c = i%channels; + int j; + unsigned int value, v; + + v = png_get_uint_16(bp); + value = 0; + + for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) + { + if (j > 0) + value |= v << j; + + else + value |= v >> (-j); + } + *bp++ = (png_byte)((value >> 8) & 0xff); + *bp++ = (png_byte)(value & 0xff); + } + } + } +} +#endif + +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED +static void +png_do_write_swap_alpha(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_write_swap_alpha"); + + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This converts from ARGB to RGBA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + png_byte save = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save; + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else + { + /* This converts from AARRGGBB to RRGGBBAA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + png_byte save[2]; + save[0] = *(sp++); + save[1] = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save[0]; + *(dp++) = save[1]; + } + } +#endif /* WRITE_16BIT */ + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This converts from AG to GA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + png_byte save = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save; + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else + { + /* This converts from AAGG to GGAA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + png_byte save[2]; + save[0] = *(sp++); + save[1] = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save[0]; + *(dp++) = save[1]; + } + } +#endif /* WRITE_16BIT */ + } + } +} +#endif + +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED +static void +png_do_write_invert_alpha(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_write_invert_alpha"); + + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This inverts the alpha channel in RGBA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + /* Does nothing + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + */ + sp+=3; dp = sp; + *dp = (png_byte)(255 - *(sp++)); + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else + { + /* This inverts the alpha channel in RRGGBBAA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + /* Does nothing + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + */ + sp+=6; dp = sp; + *(dp++) = (png_byte)(255 - *(sp++)); + *dp = (png_byte)(255 - *(sp++)); + } + } +#endif /* WRITE_16BIT */ + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This inverts the alpha channel in GA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + *(dp++) = *(sp++); + *(dp++) = (png_byte)(255 - *(sp++)); + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else + { + /* This inverts the alpha channel in GGAA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + /* Does nothing + *(dp++) = *(sp++); + *(dp++) = *(sp++); + */ + sp+=2; dp = sp; + *(dp++) = (png_byte)(255 - *(sp++)); + *dp = (png_byte)(255 - *(sp++)); + } + } +#endif /* WRITE_16BIT */ + } + } +} +#endif + +/* Transform the data according to the user's wishes. The order of + * transformations is significant. + */ +void /* PRIVATE */ +png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info) +{ + png_debug(1, "in png_do_write_transformations"); + + if (png_ptr == NULL) + return; + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED + if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) + if (png_ptr->write_user_transform_fn != NULL) + (*(png_ptr->write_user_transform_fn)) /* User write transform + function */ + (png_ptr, /* png_ptr */ + row_info, /* row_info: */ + /* png_uint_32 width; width of row */ + /* size_t rowbytes; number of bytes in row */ + /* png_byte color_type; color type of pixels */ + /* png_byte bit_depth; bit depth of samples */ + /* png_byte channels; number of channels (1-4) */ + /* png_byte pixel_depth; bits per pixel (depth*channels) */ + png_ptr->row_buf + 1); /* start of pixel data for row */ +#endif + +#ifdef PNG_WRITE_FILLER_SUPPORTED + if ((png_ptr->transformations & PNG_FILLER) != 0) + png_do_strip_channel(row_info, png_ptr->row_buf + 1, + !(png_ptr->flags & PNG_FLAG_FILLER_AFTER)); +#endif + +#ifdef PNG_WRITE_PACKSWAP_SUPPORTED + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) + png_do_packswap(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_PACK_SUPPORTED + if ((png_ptr->transformations & PNG_PACK) != 0) + png_do_pack(row_info, png_ptr->row_buf + 1, + (png_uint_32)png_ptr->bit_depth); +#endif + +#ifdef PNG_WRITE_SWAP_SUPPORTED +# ifdef PNG_16BIT_SUPPORTED + if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) + png_do_swap(row_info, png_ptr->row_buf + 1); +# endif +#endif + +#ifdef PNG_WRITE_SHIFT_SUPPORTED + if ((png_ptr->transformations & PNG_SHIFT) != 0) + png_do_shift(row_info, png_ptr->row_buf + 1, + &(png_ptr->shift)); +#endif + +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0) + png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0) + png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_BGR_SUPPORTED + if ((png_ptr->transformations & PNG_BGR) != 0) + png_do_bgr(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_INVERT_SUPPORTED + if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) + png_do_invert(row_info, png_ptr->row_buf + 1); +#endif +} +#endif /* WRITE_TRANSFORMS */ +#endif /* WRITE */ diff --git a/media/libpng/pngwutil.c b/media/libpng/pngwutil.c new file mode 100644 index 0000000000..d0715bbc1e --- /dev/null +++ b/media/libpng/pngwutil.c @@ -0,0 +1,2917 @@ + +/* pngwutil.c - utilities to write a PNG file + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#ifdef PNG_WRITE_SUPPORTED + +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED +/* Place a 32-bit number into a buffer in PNG byte order. We work + * with unsigned numbers for convenience, although one supported + * ancillary chunk uses signed (two's complement) numbers. + */ +void PNGAPI +png_save_uint_32(png_bytep buf, png_uint_32 i) +{ + buf[0] = (png_byte)((i >> 24) & 0xffU); + buf[1] = (png_byte)((i >> 16) & 0xffU); + buf[2] = (png_byte)((i >> 8) & 0xffU); + buf[3] = (png_byte)( i & 0xffU); +} + +/* Place a 16-bit number into a buffer in PNG byte order. + * The parameter is declared unsigned int, not png_uint_16, + * just to avoid potential problems on pre-ANSI C compilers. + */ +void PNGAPI +png_save_uint_16(png_bytep buf, unsigned int i) +{ + buf[0] = (png_byte)((i >> 8) & 0xffU); + buf[1] = (png_byte)( i & 0xffU); +} +#endif + +/* Simple function to write the signature. If we have already written + * the magic bytes of the signature, or more likely, the PNG stream is + * being embedded into another stream and doesn't need its own signature, + * we should call png_set_sig_bytes() to tell libpng how many of the + * bytes have already been written. + */ +void PNGAPI +png_write_sig(png_structrp png_ptr) +{ + png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the signature is being written */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE; +#endif + + /* Write the rest of the 8 byte signature */ + png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes], + (size_t)(8 - png_ptr->sig_bytes)); + + if (png_ptr->sig_bytes < 3) + png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; +} + +/* Write the start of a PNG chunk. The type is the chunk type. + * The total_length is the sum of the lengths of all the data you will be + * passing in png_write_chunk_data(). + */ +static void +png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name, + png_uint_32 length) +{ + png_byte buf[8]; + +#if defined(PNG_DEBUG) && (PNG_DEBUG > 0) + PNG_CSTRING_FROM_CHUNK(buf, chunk_name); + png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length); +#endif + + if (png_ptr == NULL) + return; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the chunk header is being written. + * PNG_IO_CHUNK_HDR requires a single I/O call. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR; +#endif + + /* Write the length and the chunk name */ + png_save_uint_32(buf, length); + png_save_uint_32(buf + 4, chunk_name); + png_write_data(png_ptr, buf, 8); + + /* Put the chunk name into png_ptr->chunk_name */ + png_ptr->chunk_name = chunk_name; + + /* Reset the crc and run it over the chunk name */ + png_reset_crc(png_ptr); + + png_calculate_crc(png_ptr, buf + 4, 4); + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that chunk data will (possibly) be written. + * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA; +#endif +} + +void PNGAPI +png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_string, + png_uint_32 length) +{ + png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length); +} + +/* Write the data of a PNG chunk started with png_write_chunk_header(). + * Note that multiple calls to this function are allowed, and that the + * sum of the lengths from these calls *must* add up to the total_length + * given to png_write_chunk_header(). + */ +void PNGAPI +png_write_chunk_data(png_structrp png_ptr, png_const_bytep data, size_t length) +{ + /* Write the data, and run the CRC over it */ + if (png_ptr == NULL) + return; + + if (data != NULL && length > 0) + { + png_write_data(png_ptr, data, length); + + /* Update the CRC after writing the data, + * in case the user I/O routine alters it. + */ + png_calculate_crc(png_ptr, data, length); + } +} + +/* Finish a chunk started with png_write_chunk_header(). */ +void PNGAPI +png_write_chunk_end(png_structrp png_ptr) +{ + png_byte buf[4]; + + if (png_ptr == NULL) return; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the chunk CRC is being written. + * PNG_IO_CHUNK_CRC requires a single I/O function call. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC; +#endif + + /* Write the crc in a single operation */ + png_save_uint_32(buf, png_ptr->crc); + + png_write_data(png_ptr, buf, 4); +} + +/* Write a PNG chunk all at once. The type is an array of ASCII characters + * representing the chunk name. The array must be at least 4 bytes in + * length, and does not need to be null terminated. To be safe, pass the + * pre-defined chunk names here, and if you need a new one, define it + * where the others are defined. The length is the length of the data. + * All the data must be present. If that is not possible, use the + * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() + * functions instead. + */ +static void +png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name, + png_const_bytep data, size_t length) +{ + if (png_ptr == NULL) + return; + + /* On 64-bit architectures 'length' may not fit in a png_uint_32. */ + if (length > PNG_UINT_31_MAX) + png_error(png_ptr, "length exceeds PNG maximum"); + + png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length); + png_write_chunk_data(png_ptr, data, length); + png_write_chunk_end(png_ptr); +} + +/* This is the API that calls the internal function above. */ +void PNGAPI +png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string, + png_const_bytep data, size_t length) +{ + png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data, + length); +} + +/* This is used below to find the size of an image to pass to png_deflate_claim, + * so it only needs to be accurate if the size is less than 16384 bytes (the + * point at which a lower LZ window size can be used.) + */ +static png_alloc_size_t +png_image_size(png_structrp png_ptr) +{ + /* Only return sizes up to the maximum of a png_uint_32; do this by limiting + * the width and height used to 15 bits. + */ + png_uint_32 h = png_ptr->height; + + if (png_ptr->rowbytes < 32768 && h < 32768) + { + if (png_ptr->interlaced != 0) + { + /* Interlacing makes the image larger because of the replication of + * both the filter byte and the padding to a byte boundary. + */ + png_uint_32 w = png_ptr->width; + unsigned int pd = png_ptr->pixel_depth; + png_alloc_size_t cb_base; + int pass; + + for (cb_base=0, pass=0; pass<=6; ++pass) + { + png_uint_32 pw = PNG_PASS_COLS(w, pass); + + if (pw > 0) + cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass); + } + + return cb_base; + } + + else + return (png_ptr->rowbytes+1) * h; + } + + else + return 0xffffffffU; +} + +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + /* This is the code to hack the first two bytes of the deflate stream (the + * deflate header) to correct the windowBits value to match the actual data + * size. Note that the second argument is the *uncompressed* size but the + * first argument is the *compressed* data (and it must be deflate + * compressed.) + */ +static void +optimize_cmf(png_bytep data, png_alloc_size_t data_size) +{ + /* Optimize the CMF field in the zlib stream. The resultant zlib stream is + * still compliant to the stream specification. + */ + if (data_size <= 16384) /* else windowBits must be 15 */ + { + unsigned int z_cmf = data[0]; /* zlib compression method and flags */ + + if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) + { + unsigned int z_cinfo; + unsigned int half_z_window_size; + + z_cinfo = z_cmf >> 4; + half_z_window_size = 1U << (z_cinfo + 7); + + if (data_size <= half_z_window_size) /* else no change */ + { + unsigned int tmp; + + do + { + half_z_window_size >>= 1; + --z_cinfo; + } + while (z_cinfo > 0 && data_size <= half_z_window_size); + + z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); + + data[0] = (png_byte)z_cmf; + tmp = data[1] & 0xe0; + tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; + data[1] = (png_byte)tmp; + } + } + } +} +#endif /* WRITE_OPTIMIZE_CMF */ + +/* Initialize the compressor for the appropriate type of compression. */ +static int +png_deflate_claim(png_structrp png_ptr, png_uint_32 owner, + png_alloc_size_t data_size) +{ + if (png_ptr->zowner != 0) + { +#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED) + char msg[64]; + + PNG_STRING_FROM_CHUNK(msg, owner); + msg[4] = ':'; + msg[5] = ' '; + PNG_STRING_FROM_CHUNK(msg+6, png_ptr->zowner); + /* So the message that results is "<chunk> using zstream"; this is an + * internal error, but is very useful for debugging. i18n requirements + * are minimal. + */ + (void)png_safecat(msg, (sizeof msg), 10, " using zstream"); +#endif +#if PNG_RELEASE_BUILD + png_warning(png_ptr, msg); + + /* Attempt sane error recovery */ + if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */ + { + png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT"); + return Z_STREAM_ERROR; + } + + png_ptr->zowner = 0; +#else + png_error(png_ptr, msg); +#endif + } + + { + int level = png_ptr->zlib_level; + int method = png_ptr->zlib_method; + int windowBits = png_ptr->zlib_window_bits; + int memLevel = png_ptr->zlib_mem_level; + int strategy; /* set below */ + int ret; /* zlib return code */ + + if (owner == png_IDAT) + { + if ((png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY) != 0) + strategy = png_ptr->zlib_strategy; + + else if (png_ptr->do_filter != PNG_FILTER_NONE) + strategy = PNG_Z_DEFAULT_STRATEGY; + + else + strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY; + } + + else + { +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED + level = png_ptr->zlib_text_level; + method = png_ptr->zlib_text_method; + windowBits = png_ptr->zlib_text_window_bits; + memLevel = png_ptr->zlib_text_mem_level; + strategy = png_ptr->zlib_text_strategy; +#else + /* If customization is not supported the values all come from the + * IDAT values except for the strategy, which is fixed to the + * default. (This is the pre-1.6.0 behavior too, although it was + * implemented in a very different way.) + */ + strategy = Z_DEFAULT_STRATEGY; +#endif + } + + /* Adjust 'windowBits' down if larger than 'data_size'; to stop this + * happening just pass 32768 as the data_size parameter. Notice that zlib + * requires an extra 262 bytes in the window in addition to the data to be + * able to see the whole of the data, so if data_size+262 takes us to the + * next windowBits size we need to fix up the value later. (Because even + * though deflate needs the extra window, inflate does not!) + */ + if (data_size <= 16384) + { + /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to + * work round a Microsoft Visual C misbehavior which, contrary to C-90, + * widens the result of the following shift to 64-bits if (and, + * apparently, only if) it is used in a test. + */ + unsigned int half_window_size = 1U << (windowBits-1); + + while (data_size + 262 <= half_window_size) + { + half_window_size >>= 1; + --windowBits; + } + } + + /* Check against the previous initialized values, if any. */ + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0 && + (png_ptr->zlib_set_level != level || + png_ptr->zlib_set_method != method || + png_ptr->zlib_set_window_bits != windowBits || + png_ptr->zlib_set_mem_level != memLevel || + png_ptr->zlib_set_strategy != strategy)) + { + if (deflateEnd(&png_ptr->zstream) != Z_OK) + png_warning(png_ptr, "deflateEnd failed (ignored)"); + + png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED; + } + + /* For safety clear out the input and output pointers (currently zlib + * doesn't use them on Init, but it might in the future). + */ + png_ptr->zstream.next_in = NULL; + png_ptr->zstream.avail_in = 0; + png_ptr->zstream.next_out = NULL; + png_ptr->zstream.avail_out = 0; + + /* Now initialize if required, setting the new parameters, otherwise just + * do a simple reset to the previous parameters. + */ + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) + ret = deflateReset(&png_ptr->zstream); + + else + { + ret = deflateInit2(&png_ptr->zstream, level, method, windowBits, + memLevel, strategy); + + if (ret == Z_OK) + png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED; + } + + /* The return code is from either deflateReset or deflateInit2; they have + * pretty much the same set of error codes. + */ + if (ret == Z_OK) + png_ptr->zowner = owner; + + else + png_zstream_error(png_ptr, ret); + + return ret; + } +} + +/* Clean up (or trim) a linked list of compression buffers. */ +void /* PRIVATE */ +png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp) +{ + png_compression_bufferp list = *listp; + + if (list != NULL) + { + *listp = NULL; + + do + { + png_compression_bufferp next = list->next; + + png_free(png_ptr, list); + list = next; + } + while (list != NULL); + } +} + +#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED +/* This pair of functions encapsulates the operation of (a) compressing a + * text string, and (b) issuing it later as a series of chunk data writes. + * The compression_state structure is shared context for these functions + * set up by the caller to allow access to the relevant local variables. + * + * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size + * temporary buffers. From 1.6.0 it is retained in png_struct so that it will + * be correctly freed in the event of a write error (previous implementations + * just leaked memory.) + */ +typedef struct +{ + png_const_bytep input; /* The uncompressed input data */ + png_alloc_size_t input_len; /* Its length */ + png_uint_32 output_len; /* Final compressed length */ + png_byte output[1024]; /* First block of output */ +} compression_state; + +static void +png_text_compress_init(compression_state *comp, png_const_bytep input, + png_alloc_size_t input_len) +{ + comp->input = input; + comp->input_len = input_len; + comp->output_len = 0; +} + +/* Compress the data in the compression state input */ +static int +png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name, + compression_state *comp, png_uint_32 prefix_len) +{ + int ret; + + /* To find the length of the output it is necessary to first compress the + * input. The result is buffered rather than using the two-pass algorithm + * that is used on the inflate side; deflate is assumed to be slower and a + * PNG writer is assumed to have more memory available than a PNG reader. + * + * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an + * upper limit on the output size, but it is always bigger than the input + * size so it is likely to be more efficient to use this linked-list + * approach. + */ + ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len); + + if (ret != Z_OK) + return ret; + + /* Set up the compression buffers, we need a loop here to avoid overflowing a + * uInt. Use ZLIB_IO_MAX to limit the input. The output is always limited + * by the output buffer size, so there is no need to check that. Since this + * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits + * in size. + */ + { + png_compression_bufferp *end = &png_ptr->zbuffer_list; + png_alloc_size_t input_len = comp->input_len; /* may be zero! */ + png_uint_32 output_len; + + /* zlib updates these for us: */ + png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input); + png_ptr->zstream.avail_in = 0; /* Set below */ + png_ptr->zstream.next_out = comp->output; + png_ptr->zstream.avail_out = (sizeof comp->output); + + output_len = png_ptr->zstream.avail_out; + + do + { + uInt avail_in = ZLIB_IO_MAX; + + if (avail_in > input_len) + avail_in = (uInt)input_len; + + input_len -= avail_in; + + png_ptr->zstream.avail_in = avail_in; + + if (png_ptr->zstream.avail_out == 0) + { + png_compression_buffer *next; + + /* Chunk data is limited to 2^31 bytes in length, so the prefix + * length must be counted here. + */ + if (output_len + prefix_len > PNG_UINT_31_MAX) + { + ret = Z_MEM_ERROR; + break; + } + + /* Need a new (malloc'ed) buffer, but there may be one present + * already. + */ + next = *end; + if (next == NULL) + { + next = png_voidcast(png_compression_bufferp, png_malloc_base + (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr))); + + if (next == NULL) + { + ret = Z_MEM_ERROR; + break; + } + + /* Link in this buffer (so that it will be freed later) */ + next->next = NULL; + *end = next; + } + + png_ptr->zstream.next_out = next->output; + png_ptr->zstream.avail_out = png_ptr->zbuffer_size; + output_len += png_ptr->zstream.avail_out; + + /* Move 'end' to the next buffer pointer. */ + end = &next->next; + } + + /* Compress the data */ + ret = deflate(&png_ptr->zstream, + input_len > 0 ? Z_NO_FLUSH : Z_FINISH); + + /* Claw back input data that was not consumed (because avail_in is + * reset above every time round the loop). + */ + input_len += png_ptr->zstream.avail_in; + png_ptr->zstream.avail_in = 0; /* safety */ + } + while (ret == Z_OK); + + /* There may be some space left in the last output buffer. This needs to + * be subtracted from output_len. + */ + output_len -= png_ptr->zstream.avail_out; + png_ptr->zstream.avail_out = 0; /* safety */ + comp->output_len = output_len; + + /* Now double check the output length, put in a custom message if it is + * too long. Otherwise ensure the z_stream::msg pointer is set to + * something. + */ + if (output_len + prefix_len >= PNG_UINT_31_MAX) + { + png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long"); + ret = Z_MEM_ERROR; + } + + else + png_zstream_error(png_ptr, ret); + + /* Reset zlib for another zTXt/iTXt or image data */ + png_ptr->zowner = 0; + + /* The only success case is Z_STREAM_END, input_len must be 0; if not this + * is an internal error. + */ + if (ret == Z_STREAM_END && input_len == 0) + { +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + /* Fix up the deflate header, if required */ + optimize_cmf(comp->output, comp->input_len); +#endif + /* But Z_OK is returned, not Z_STREAM_END; this allows the claim + * function above to return Z_STREAM_END on an error (though it never + * does in the current versions of zlib.) + */ + return Z_OK; + } + + else + return ret; + } +} + +/* Ship the compressed text out via chunk writes */ +static void +png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp) +{ + png_uint_32 output_len = comp->output_len; + png_const_bytep output = comp->output; + png_uint_32 avail = (sizeof comp->output); + png_compression_buffer *next = png_ptr->zbuffer_list; + + for (;;) + { + if (avail > output_len) + avail = output_len; + + png_write_chunk_data(png_ptr, output, avail); + + output_len -= avail; + + if (output_len == 0 || next == NULL) + break; + + avail = png_ptr->zbuffer_size; + output = next->output; + next = next->next; + } + + /* This is an internal error; 'next' must have been NULL! */ + if (output_len > 0) + png_error(png_ptr, "error writing ancillary chunked compressed data"); +} +#endif /* WRITE_COMPRESSED_TEXT */ + +/* Write the IHDR chunk, and update the png_struct with the necessary + * information. Note that the rest of this code depends upon this + * information being correct. + */ +void /* PRIVATE */ +png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height, + int bit_depth, int color_type, int compression_type, int filter_type, + int interlace_type) +{ + png_byte buf[13]; /* Buffer to store the IHDR info */ + int is_invalid_depth; + + png_debug(1, "in png_write_IHDR"); + + /* Check that we have valid input data from the application info */ + switch (color_type) + { + case PNG_COLOR_TYPE_GRAY: + switch (bit_depth) + { + case 1: + case 2: + case 4: + case 8: +#ifdef PNG_WRITE_16BIT_SUPPORTED + case 16: +#endif + png_ptr->channels = 1; break; + + default: + png_error(png_ptr, + "Invalid bit depth for grayscale image"); + } + break; + + case PNG_COLOR_TYPE_RGB: + is_invalid_depth = (bit_depth != 8); +#ifdef PNG_WRITE_16BIT_SUPPORTED + is_invalid_depth = (is_invalid_depth && bit_depth != 16); +#endif + if (is_invalid_depth) + png_error(png_ptr, "Invalid bit depth for RGB image"); + + png_ptr->channels = 3; + break; + + case PNG_COLOR_TYPE_PALETTE: + switch (bit_depth) + { + case 1: + case 2: + case 4: + case 8: + png_ptr->channels = 1; + break; + + default: + png_error(png_ptr, "Invalid bit depth for paletted image"); + } + break; + + case PNG_COLOR_TYPE_GRAY_ALPHA: + is_invalid_depth = (bit_depth != 8); +#ifdef PNG_WRITE_16BIT_SUPPORTED + is_invalid_depth = (is_invalid_depth && bit_depth != 16); +#endif + if (is_invalid_depth) + png_error(png_ptr, "Invalid bit depth for grayscale+alpha image"); + + png_ptr->channels = 2; + break; + + case PNG_COLOR_TYPE_RGB_ALPHA: + is_invalid_depth = (bit_depth != 8); +#ifdef PNG_WRITE_16BIT_SUPPORTED + is_invalid_depth = (is_invalid_depth && bit_depth != 16); +#endif + if (is_invalid_depth) + png_error(png_ptr, "Invalid bit depth for RGBA image"); + + png_ptr->channels = 4; + break; + + default: + png_error(png_ptr, "Invalid image color type specified"); + } + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + { + png_warning(png_ptr, "Invalid compression type specified"); + compression_type = PNG_COMPRESSION_TYPE_BASE; + } + + /* Write filter_method 64 (intrapixel differencing) only if + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and + * 2. Libpng did not write a PNG signature (this filter_method is only + * used in PNG datastreams that are embedded in MNG datastreams) and + * 3. The application called png_permit_mng_features with a mask that + * included PNG_FLAG_MNG_FILTER_64 and + * 4. The filter_method is 64 and + * 5. The color_type is RGB or RGBA + */ + if ( +#ifdef PNG_MNG_FEATURES_SUPPORTED + !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && + ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) && + (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) && + (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) && +#endif + filter_type != PNG_FILTER_TYPE_BASE) + { + png_warning(png_ptr, "Invalid filter type specified"); + filter_type = PNG_FILTER_TYPE_BASE; + } + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + if (interlace_type != PNG_INTERLACE_NONE && + interlace_type != PNG_INTERLACE_ADAM7) + { + png_warning(png_ptr, "Invalid interlace type specified"); + interlace_type = PNG_INTERLACE_ADAM7; + } +#else + interlace_type=PNG_INTERLACE_NONE; +#endif + + /* Save the relevant information */ + png_ptr->bit_depth = (png_byte)bit_depth; + png_ptr->color_type = (png_byte)color_type; + png_ptr->interlaced = (png_byte)interlace_type; +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_ptr->filter_type = (png_byte)filter_type; +#endif + png_ptr->compression_type = (png_byte)compression_type; + png_ptr->width = width; + png_ptr->height = height; + + png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels); + png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width); + /* Set the usr info, so any transformations can modify it */ + png_ptr->usr_width = png_ptr->width; + png_ptr->usr_bit_depth = png_ptr->bit_depth; + png_ptr->usr_channels = png_ptr->channels; + + /* Pack the header information into the buffer */ + png_save_uint_32(buf, width); + png_save_uint_32(buf + 4, height); + buf[8] = (png_byte)bit_depth; + buf[9] = (png_byte)color_type; + buf[10] = (png_byte)compression_type; + buf[11] = (png_byte)filter_type; + buf[12] = (png_byte)interlace_type; + + /* Write the chunk */ + png_write_complete_chunk(png_ptr, png_IHDR, buf, 13); + +#ifdef PNG_WRITE_APNG_SUPPORTED + png_ptr->first_frame_width = width; + png_ptr->first_frame_height = height; +#endif + + if ((png_ptr->do_filter) == PNG_NO_FILTERS) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || + png_ptr->bit_depth < 8) + png_ptr->do_filter = PNG_FILTER_NONE; + + else + png_ptr->do_filter = PNG_ALL_FILTERS; + } + + png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */ +} + +/* Write the palette. We are careful not to trust png_color to be in the + * correct order for PNG, so people can redefine it to any convenient + * structure. + */ +void /* PRIVATE */ +png_write_PLTE(png_structrp png_ptr, png_const_colorp palette, + png_uint_32 num_pal) +{ + png_uint_32 max_palette_length, i; + png_const_colorp pal_ptr; + png_byte buf[3]; + + png_debug(1, "in png_write_PLTE"); + + max_palette_length = (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ? + (1 << png_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH; + + if (( +#ifdef PNG_MNG_FEATURES_SUPPORTED + (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0 && +#endif + num_pal == 0) || num_pal > max_palette_length) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + png_error(png_ptr, "Invalid number of colors in palette"); + } + + else + { + png_warning(png_ptr, "Invalid number of colors in palette"); + return; + } + } + + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) + { + png_warning(png_ptr, + "Ignoring request to write a PLTE chunk in grayscale PNG"); + + return; + } + + png_ptr->num_palette = (png_uint_16)num_pal; + png_debug1(3, "num_palette = %d", png_ptr->num_palette); + + png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3)); +#ifdef PNG_POINTER_INDEXING_SUPPORTED + + for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++) + { + buf[0] = pal_ptr->red; + buf[1] = pal_ptr->green; + buf[2] = pal_ptr->blue; + png_write_chunk_data(png_ptr, buf, 3); + } + +#else + /* This is a little slower but some buggy compilers need to do this + * instead + */ + pal_ptr=palette; + + for (i = 0; i < num_pal; i++) + { + buf[0] = pal_ptr[i].red; + buf[1] = pal_ptr[i].green; + buf[2] = pal_ptr[i].blue; + png_write_chunk_data(png_ptr, buf, 3); + } + +#endif + png_write_chunk_end(png_ptr); + png_ptr->mode |= PNG_HAVE_PLTE; +} + +/* This is similar to png_text_compress, above, except that it does not require + * all of the data at once and, instead of buffering the compressed result, + * writes it as IDAT chunks. Unlike png_text_compress it *can* png_error out + * because it calls the write interface. As a result it does its own error + * reporting and does not return an error code. In the event of error it will + * just call png_error. The input data length may exceed 32-bits. The 'flush' + * parameter is exactly the same as that to deflate, with the following + * meanings: + * + * Z_NO_FLUSH: normal incremental output of compressed data + * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush + * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up + * + * The routine manages the acquire and release of the png_ptr->zstream by + * checking and (at the end) clearing png_ptr->zowner; it does some sanity + * checks on the 'mode' flags while doing this. + */ +void /* PRIVATE */ +png_compress_IDAT(png_structrp png_ptr, png_const_bytep input, + png_alloc_size_t input_len, int flush) +{ + if (png_ptr->zowner != png_IDAT) + { + /* First time. Ensure we have a temporary buffer for compression and + * trim the buffer list if it has more than one entry to free memory. + * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been + * created at this point, but the check here is quick and safe. + */ + if (png_ptr->zbuffer_list == NULL) + { + png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp, + png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr))); + png_ptr->zbuffer_list->next = NULL; + } + + else + png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next); + + /* It is a terminal error if we can't claim the zstream. */ + if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + + /* The output state is maintained in png_ptr->zstream, so it must be + * initialized here after the claim. + */ + png_ptr->zstream.next_out = png_ptr->zbuffer_list->output; + png_ptr->zstream.avail_out = png_ptr->zbuffer_size; + } + + /* Now loop reading and writing until all the input is consumed or an error + * terminates the operation. The _out values are maintained across calls to + * this function, but the input must be reset each time. + */ + png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input); + png_ptr->zstream.avail_in = 0; /* set below */ + for (;;) + { + int ret; + + /* INPUT: from the row data */ + uInt avail = ZLIB_IO_MAX; + + if (avail > input_len) + avail = (uInt)input_len; /* safe because of the check */ + + png_ptr->zstream.avail_in = avail; + input_len -= avail; + + ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush); + + /* Include as-yet unconsumed input */ + input_len += png_ptr->zstream.avail_in; + png_ptr->zstream.avail_in = 0; + + /* OUTPUT: write complete IDAT chunks when avail_out drops to zero. Note + * that these two zstream fields are preserved across the calls, therefore + * there is no need to set these up on entry to the loop. + */ + if (png_ptr->zstream.avail_out == 0) + { + png_bytep data = png_ptr->zbuffer_list->output; + uInt size = png_ptr->zbuffer_size; + + /* Write an IDAT containing the data then reset the buffer. The + * first IDAT may need deflate header optimization. + */ +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 && + png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) + optimize_cmf(data, png_image_size(png_ptr)); +#endif + + if (size > 0) +#ifdef PNG_WRITE_APNG_SUPPORTED + { + if (png_ptr->num_frames_written == 0) +#endif + png_write_complete_chunk(png_ptr, png_IDAT, data, size); +#ifdef PNG_WRITE_APNG_SUPPORTED + else + png_write_fdAT(png_ptr, data, size); + } +#endif /* WRITE_APNG */ + + png_ptr->mode |= PNG_HAVE_IDAT; + + png_ptr->zstream.next_out = data; + png_ptr->zstream.avail_out = size; + + /* For SYNC_FLUSH or FINISH it is essential to keep calling zlib with + * the same flush parameter until it has finished output, for NO_FLUSH + * it doesn't matter. + */ + if (ret == Z_OK && flush != Z_NO_FLUSH) + continue; + } + + /* The order of these checks doesn't matter much; it just affects which + * possible error might be detected if multiple things go wrong at once. + */ + if (ret == Z_OK) /* most likely return code! */ + { + /* If all the input has been consumed then just return. If Z_FINISH + * was used as the flush parameter something has gone wrong if we get + * here. + */ + if (input_len == 0) + { + if (flush == Z_FINISH) + png_error(png_ptr, "Z_OK on Z_FINISH with output space"); + + return; + } + } + + else if (ret == Z_STREAM_END && flush == Z_FINISH) + { + /* This is the end of the IDAT data; any pending output must be + * flushed. For small PNG files we may still be at the beginning. + */ + png_bytep data = png_ptr->zbuffer_list->output; + uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out; + +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 && + png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) + optimize_cmf(data, png_image_size(png_ptr)); +#endif + + if (size > 0) +#ifdef PNG_WRITE_APNG_SUPPORTED + { + if (png_ptr->num_frames_written == 0) +#endif + png_write_complete_chunk(png_ptr, png_IDAT, data, size); +#ifdef PNG_WRITE_APNG_SUPPORTED + else + png_write_fdAT(png_ptr, data, size); + } +#endif /* WRITE_APNG */ + + png_ptr->zstream.avail_out = 0; + png_ptr->zstream.next_out = NULL; + png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT; + + png_ptr->zowner = 0; /* Release the stream */ + return; + } + + else + { + /* This is an error condition. */ + png_zstream_error(png_ptr, ret); + png_error(png_ptr, png_ptr->zstream.msg); + } + } +} + +/* Write an IEND chunk */ +void /* PRIVATE */ +png_write_IEND(png_structrp png_ptr) +{ + png_debug(1, "in png_write_IEND"); + + png_write_complete_chunk(png_ptr, png_IEND, NULL, 0); + png_ptr->mode |= PNG_HAVE_IEND; +} + +#ifdef PNG_WRITE_gAMA_SUPPORTED +/* Write a gAMA chunk */ +void /* PRIVATE */ +png_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma) +{ + png_byte buf[4]; + + png_debug(1, "in png_write_gAMA"); + + /* file_gamma is saved in 1/100,000ths */ + png_save_uint_32(buf, (png_uint_32)file_gamma); + png_write_complete_chunk(png_ptr, png_gAMA, buf, 4); +} +#endif + +#ifdef PNG_WRITE_sRGB_SUPPORTED +/* Write a sRGB chunk */ +void /* PRIVATE */ +png_write_sRGB(png_structrp png_ptr, int srgb_intent) +{ + png_byte buf[1]; + + png_debug(1, "in png_write_sRGB"); + + if (srgb_intent >= PNG_sRGB_INTENT_LAST) + png_warning(png_ptr, + "Invalid sRGB rendering intent specified"); + + buf[0]=(png_byte)srgb_intent; + png_write_complete_chunk(png_ptr, png_sRGB, buf, 1); +} +#endif + +#ifdef PNG_WRITE_iCCP_SUPPORTED +/* Write an iCCP chunk */ +void /* PRIVATE */ +png_write_iCCP(png_structrp png_ptr, png_const_charp name, + png_const_bytep profile) +{ + png_uint_32 name_len; + png_uint_32 profile_len; + png_byte new_name[81]; /* 1 byte for the compression byte */ + compression_state comp; + png_uint_32 temp; + + png_debug(1, "in png_write_iCCP"); + + /* These are all internal problems: the profile should have been checked + * before when it was stored. + */ + if (profile == NULL) + png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */ + + profile_len = png_get_uint_32(profile); + + if (profile_len < 132) + png_error(png_ptr, "ICC profile too short"); + + temp = (png_uint_32) (*(profile+8)); + if (temp > 3 && (profile_len & 0x03)) + png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)"); + + { + png_uint_32 embedded_profile_len = png_get_uint_32(profile); + + if (profile_len != embedded_profile_len) + png_error(png_ptr, "Profile length does not match profile"); + } + + name_len = png_check_keyword(png_ptr, name, new_name); + + if (name_len == 0) + png_error(png_ptr, "iCCP: invalid keyword"); + + new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE; + + /* Make sure we include the NULL after the name and the compression type */ + ++name_len; + + png_text_compress_init(&comp, profile, profile_len); + + /* Allow for keyword terminator and compression byte */ + if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + + png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len); + + png_write_chunk_data(png_ptr, new_name, name_len); + + png_write_compressed_data_out(png_ptr, &comp); + + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_sPLT_SUPPORTED +/* Write a sPLT chunk */ +void /* PRIVATE */ +png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette) +{ + png_uint_32 name_len; + png_byte new_name[80]; + png_byte entrybuf[10]; + size_t entry_size = (spalette->depth == 8 ? 6 : 10); + size_t palette_size = entry_size * (size_t)spalette->nentries; + png_sPLT_entryp ep; +#ifndef PNG_POINTER_INDEXING_SUPPORTED + int i; +#endif + + png_debug(1, "in png_write_sPLT"); + + name_len = png_check_keyword(png_ptr, spalette->name, new_name); + + if (name_len == 0) + png_error(png_ptr, "sPLT: invalid keyword"); + + /* Make sure we include the NULL after the name */ + png_write_chunk_header(png_ptr, png_sPLT, + (png_uint_32)(name_len + 2 + palette_size)); + + png_write_chunk_data(png_ptr, (png_bytep)new_name, (size_t)(name_len + 1)); + + png_write_chunk_data(png_ptr, &spalette->depth, 1); + + /* Loop through each palette entry, writing appropriately */ +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++) + { + if (spalette->depth == 8) + { + entrybuf[0] = (png_byte)ep->red; + entrybuf[1] = (png_byte)ep->green; + entrybuf[2] = (png_byte)ep->blue; + entrybuf[3] = (png_byte)ep->alpha; + png_save_uint_16(entrybuf + 4, ep->frequency); + } + + else + { + png_save_uint_16(entrybuf + 0, ep->red); + png_save_uint_16(entrybuf + 2, ep->green); + png_save_uint_16(entrybuf + 4, ep->blue); + png_save_uint_16(entrybuf + 6, ep->alpha); + png_save_uint_16(entrybuf + 8, ep->frequency); + } + + png_write_chunk_data(png_ptr, entrybuf, entry_size); + } +#else + ep=spalette->entries; + for (i = 0; i>spalette->nentries; i++) + { + if (spalette->depth == 8) + { + entrybuf[0] = (png_byte)ep[i].red; + entrybuf[1] = (png_byte)ep[i].green; + entrybuf[2] = (png_byte)ep[i].blue; + entrybuf[3] = (png_byte)ep[i].alpha; + png_save_uint_16(entrybuf + 4, ep[i].frequency); + } + + else + { + png_save_uint_16(entrybuf + 0, ep[i].red); + png_save_uint_16(entrybuf + 2, ep[i].green); + png_save_uint_16(entrybuf + 4, ep[i].blue); + png_save_uint_16(entrybuf + 6, ep[i].alpha); + png_save_uint_16(entrybuf + 8, ep[i].frequency); + } + + png_write_chunk_data(png_ptr, entrybuf, entry_size); + } +#endif + + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_sBIT_SUPPORTED +/* Write the sBIT chunk */ +void /* PRIVATE */ +png_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type) +{ + png_byte buf[4]; + size_t size; + + png_debug(1, "in png_write_sBIT"); + + /* Make sure we don't depend upon the order of PNG_COLOR_8 */ + if ((color_type & PNG_COLOR_MASK_COLOR) != 0) + { + png_byte maxbits; + + maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 : + png_ptr->usr_bit_depth); + + if (sbit->red == 0 || sbit->red > maxbits || + sbit->green == 0 || sbit->green > maxbits || + sbit->blue == 0 || sbit->blue > maxbits) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + + buf[0] = sbit->red; + buf[1] = sbit->green; + buf[2] = sbit->blue; + size = 3; + } + + else + { + if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + + buf[0] = sbit->gray; + size = 1; + } + + if ((color_type & PNG_COLOR_MASK_ALPHA) != 0) + { + if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + + buf[size++] = sbit->alpha; + } + + png_write_complete_chunk(png_ptr, png_sBIT, buf, size); +} +#endif + +#ifdef PNG_WRITE_cHRM_SUPPORTED +/* Write the cHRM chunk */ +void /* PRIVATE */ +png_write_cHRM_fixed(png_structrp png_ptr, const png_xy *xy) +{ + png_byte buf[32]; + + png_debug(1, "in png_write_cHRM"); + + /* Each value is saved in 1/100,000ths */ + png_save_int_32(buf, xy->whitex); + png_save_int_32(buf + 4, xy->whitey); + + png_save_int_32(buf + 8, xy->redx); + png_save_int_32(buf + 12, xy->redy); + + png_save_int_32(buf + 16, xy->greenx); + png_save_int_32(buf + 20, xy->greeny); + + png_save_int_32(buf + 24, xy->bluex); + png_save_int_32(buf + 28, xy->bluey); + + png_write_complete_chunk(png_ptr, png_cHRM, buf, 32); +} +#endif + +#ifdef PNG_WRITE_tRNS_SUPPORTED +/* Write the tRNS chunk */ +void /* PRIVATE */ +png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha, + png_const_color_16p tran, int num_trans, int color_type) +{ + png_byte buf[6]; + + png_debug(1, "in png_write_tRNS"); + + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) + { + png_app_warning(png_ptr, + "Invalid number of transparent colors specified"); + return; + } + + /* Write the chunk out as it is */ + png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha, + (size_t)num_trans); + } + + else if (color_type == PNG_COLOR_TYPE_GRAY) + { + /* One 16-bit value */ + if (tran->gray >= (1 << png_ptr->bit_depth)) + { + png_app_warning(png_ptr, + "Ignoring attempt to write tRNS chunk out-of-range for bit_depth"); + + return; + } + + png_save_uint_16(buf, tran->gray); + png_write_complete_chunk(png_ptr, png_tRNS, buf, 2); + } + + else if (color_type == PNG_COLOR_TYPE_RGB) + { + /* Three 16-bit values */ + png_save_uint_16(buf, tran->red); + png_save_uint_16(buf + 2, tran->green); + png_save_uint_16(buf + 4, tran->blue); +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0) +#else + if ((buf[0] | buf[2] | buf[4]) != 0) +#endif + { + png_app_warning(png_ptr, + "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); + return; + } + + png_write_complete_chunk(png_ptr, png_tRNS, buf, 6); + } + + else + { + png_app_warning(png_ptr, "Can't write tRNS with an alpha channel"); + } +} +#endif + +#ifdef PNG_WRITE_bKGD_SUPPORTED +/* Write the background chunk */ +void /* PRIVATE */ +png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type) +{ + png_byte buf[6]; + + png_debug(1, "in png_write_bKGD"); + + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + if ( +#ifdef PNG_MNG_FEATURES_SUPPORTED + (png_ptr->num_palette != 0 || + (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0) && +#endif + back->index >= png_ptr->num_palette) + { + png_warning(png_ptr, "Invalid background palette index"); + return; + } + + buf[0] = back->index; + png_write_complete_chunk(png_ptr, png_bKGD, buf, 1); + } + + else if ((color_type & PNG_COLOR_MASK_COLOR) != 0) + { + png_save_uint_16(buf, back->red); + png_save_uint_16(buf + 2, back->green); + png_save_uint_16(buf + 4, back->blue); +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0) +#else + if ((buf[0] | buf[2] | buf[4]) != 0) +#endif + { + png_warning(png_ptr, + "Ignoring attempt to write 16-bit bKGD chunk " + "when bit_depth is 8"); + + return; + } + + png_write_complete_chunk(png_ptr, png_bKGD, buf, 6); + } + + else + { + if (back->gray >= (1 << png_ptr->bit_depth)) + { + png_warning(png_ptr, + "Ignoring attempt to write bKGD chunk out-of-range for bit_depth"); + + return; + } + + png_save_uint_16(buf, back->gray); + png_write_complete_chunk(png_ptr, png_bKGD, buf, 2); + } +} +#endif + +#ifdef PNG_WRITE_eXIf_SUPPORTED +/* Write the Exif data */ +void /* PRIVATE */ +png_write_eXIf(png_structrp png_ptr, png_bytep exif, int num_exif) +{ + int i; + png_byte buf[1]; + + png_debug(1, "in png_write_eXIf"); + + png_write_chunk_header(png_ptr, png_eXIf, (png_uint_32)(num_exif)); + + for (i = 0; i < num_exif; i++) + { + buf[0] = exif[i]; + png_write_chunk_data(png_ptr, buf, 1); + } + + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_hIST_SUPPORTED +/* Write the histogram */ +void /* PRIVATE */ +png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist) +{ + int i; + png_byte buf[3]; + + png_debug(1, "in png_write_hIST"); + + if (num_hist > (int)png_ptr->num_palette) + { + png_debug2(3, "num_hist = %d, num_palette = %d", num_hist, + png_ptr->num_palette); + + png_warning(png_ptr, "Invalid number of histogram entries specified"); + return; + } + + png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); + + for (i = 0; i < num_hist; i++) + { + png_save_uint_16(buf, hist[i]); + png_write_chunk_data(png_ptr, buf, 2); + } + + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_tEXt_SUPPORTED +/* Write a tEXt chunk */ +void /* PRIVATE */ +png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text, + size_t text_len) +{ + png_uint_32 key_len; + png_byte new_key[80]; + + png_debug(1, "in png_write_tEXt"); + + key_len = png_check_keyword(png_ptr, key, new_key); + + if (key_len == 0) + png_error(png_ptr, "tEXt: invalid keyword"); + + if (text == NULL || *text == '\0') + text_len = 0; + + else + text_len = strlen(text); + + if (text_len > PNG_UINT_31_MAX - (key_len+1)) + png_error(png_ptr, "tEXt: text too long"); + + /* Make sure we include the 0 after the key */ + png_write_chunk_header(png_ptr, png_tEXt, + (png_uint_32)/*checked above*/(key_len + text_len + 1)); + /* + * We leave it to the application to meet PNG-1.0 requirements on the + * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of + * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. + */ + png_write_chunk_data(png_ptr, new_key, key_len + 1); + + if (text_len != 0) + png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len); + + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_zTXt_SUPPORTED +/* Write a compressed text chunk */ +void /* PRIVATE */ +png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text, + int compression) +{ + png_uint_32 key_len; + png_byte new_key[81]; + compression_state comp; + + png_debug(1, "in png_write_zTXt"); + + if (compression == PNG_TEXT_COMPRESSION_NONE) + { + png_write_tEXt(png_ptr, key, text, 0); + return; + } + + if (compression != PNG_TEXT_COMPRESSION_zTXt) + png_error(png_ptr, "zTXt: invalid compression type"); + + key_len = png_check_keyword(png_ptr, key, new_key); + + if (key_len == 0) + png_error(png_ptr, "zTXt: invalid keyword"); + + /* Add the compression method and 1 for the keyword separator. */ + new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE; + ++key_len; + + /* Compute the compressed data; do it now for the length */ + png_text_compress_init(&comp, (png_const_bytep)text, + text == NULL ? 0 : strlen(text)); + + if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + + /* Write start of chunk */ + png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len); + + /* Write key */ + png_write_chunk_data(png_ptr, new_key, key_len); + + /* Write the compressed data */ + png_write_compressed_data_out(png_ptr, &comp); + + /* Close the chunk */ + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_iTXt_SUPPORTED +/* Write an iTXt chunk */ +void /* PRIVATE */ +png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key, + png_const_charp lang, png_const_charp lang_key, png_const_charp text) +{ + png_uint_32 key_len, prefix_len; + size_t lang_len, lang_key_len; + png_byte new_key[82]; + compression_state comp; + + png_debug(1, "in png_write_iTXt"); + + key_len = png_check_keyword(png_ptr, key, new_key); + + if (key_len == 0) + png_error(png_ptr, "iTXt: invalid keyword"); + + /* Set the compression flag */ + switch (compression) + { + case PNG_ITXT_COMPRESSION_NONE: + case PNG_TEXT_COMPRESSION_NONE: + compression = new_key[++key_len] = 0; /* no compression */ + break; + + case PNG_TEXT_COMPRESSION_zTXt: + case PNG_ITXT_COMPRESSION_zTXt: + compression = new_key[++key_len] = 1; /* compressed */ + break; + + default: + png_error(png_ptr, "iTXt: invalid compression"); + } + + new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE; + ++key_len; /* for the keywod separator */ + + /* We leave it to the application to meet PNG-1.0 requirements on the + * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of + * any non-Latin-1 characters except for NEWLINE. ISO PNG, however, + * specifies that the text is UTF-8 and this really doesn't require any + * checking. + * + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. + * + * TODO: validate the language tag correctly (see the spec.) + */ + if (lang == NULL) lang = ""; /* empty language is valid */ + lang_len = strlen(lang)+1; + if (lang_key == NULL) lang_key = ""; /* may be empty */ + lang_key_len = strlen(lang_key)+1; + if (text == NULL) text = ""; /* may be empty */ + + prefix_len = key_len; + if (lang_len > PNG_UINT_31_MAX-prefix_len) + prefix_len = PNG_UINT_31_MAX; + else + prefix_len = (png_uint_32)(prefix_len + lang_len); + + if (lang_key_len > PNG_UINT_31_MAX-prefix_len) + prefix_len = PNG_UINT_31_MAX; + else + prefix_len = (png_uint_32)(prefix_len + lang_key_len); + + png_text_compress_init(&comp, (png_const_bytep)text, strlen(text)); + + if (compression != 0) + { + if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + } + + else + { + if (comp.input_len > PNG_UINT_31_MAX-prefix_len) + png_error(png_ptr, "iTXt: uncompressed text too long"); + + /* So the string will fit in a chunk: */ + comp.output_len = (png_uint_32)/*SAFE*/comp.input_len; + } + + png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len); + + png_write_chunk_data(png_ptr, new_key, key_len); + + png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len); + + png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len); + + if (compression != 0) + png_write_compressed_data_out(png_ptr, &comp); + + else + png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.output_len); + + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_oFFs_SUPPORTED +/* Write the oFFs chunk */ +void /* PRIVATE */ +png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset, + int unit_type) +{ + png_byte buf[9]; + + png_debug(1, "in png_write_oFFs"); + + if (unit_type >= PNG_OFFSET_LAST) + png_warning(png_ptr, "Unrecognized unit type for oFFs chunk"); + + png_save_int_32(buf, x_offset); + png_save_int_32(buf + 4, y_offset); + buf[8] = (png_byte)unit_type; + + png_write_complete_chunk(png_ptr, png_oFFs, buf, 9); +} +#endif +#ifdef PNG_WRITE_pCAL_SUPPORTED +/* Write the pCAL chunk (described in the PNG extensions document) */ +void /* PRIVATE */ +png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0, + png_int_32 X1, int type, int nparams, png_const_charp units, + png_charpp params) +{ + png_uint_32 purpose_len; + size_t units_len, total_len; + png_size_tp params_len; + png_byte buf[10]; + png_byte new_purpose[80]; + int i; + + png_debug1(1, "in png_write_pCAL (%d parameters)", nparams); + + if (type >= PNG_EQUATION_LAST) + png_error(png_ptr, "Unrecognized equation type for pCAL chunk"); + + purpose_len = png_check_keyword(png_ptr, purpose, new_purpose); + + if (purpose_len == 0) + png_error(png_ptr, "pCAL: invalid keyword"); + + ++purpose_len; /* terminator */ + + png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); + units_len = strlen(units) + (nparams == 0 ? 0 : 1); + png_debug1(3, "pCAL units length = %d", (int)units_len); + total_len = purpose_len + units_len + 10; + + params_len = (png_size_tp)png_malloc(png_ptr, + (png_alloc_size_t)((png_alloc_size_t)nparams * (sizeof (size_t)))); + + /* Find the length of each parameter, making sure we don't count the + * null terminator for the last parameter. + */ + for (i = 0; i < nparams; i++) + { + params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1); + png_debug2(3, "pCAL parameter %d length = %lu", i, + (unsigned long)params_len[i]); + total_len += params_len[i]; + } + + png_debug1(3, "pCAL total length = %d", (int)total_len); + png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len); + png_write_chunk_data(png_ptr, new_purpose, purpose_len); + png_save_int_32(buf, X0); + png_save_int_32(buf + 4, X1); + buf[8] = (png_byte)type; + buf[9] = (png_byte)nparams; + png_write_chunk_data(png_ptr, buf, 10); + png_write_chunk_data(png_ptr, (png_const_bytep)units, (size_t)units_len); + + for (i = 0; i < nparams; i++) + { + png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]); + } + + png_free(png_ptr, params_len); + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_sCAL_SUPPORTED +/* Write the sCAL chunk */ +void /* PRIVATE */ +png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width, + png_const_charp height) +{ + png_byte buf[64]; + size_t wlen, hlen, total_len; + + png_debug(1, "in png_write_sCAL_s"); + + wlen = strlen(width); + hlen = strlen(height); + total_len = wlen + hlen + 2; + + if (total_len > 64) + { + png_warning(png_ptr, "Can't write sCAL (buffer too small)"); + return; + } + + buf[0] = (png_byte)unit; + memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */ + memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */ + + png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); + png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len); +} +#endif + +#ifdef PNG_WRITE_pHYs_SUPPORTED +/* Write the pHYs chunk */ +void /* PRIVATE */ +png_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit, + png_uint_32 y_pixels_per_unit, + int unit_type) +{ + png_byte buf[9]; + + png_debug(1, "in png_write_pHYs"); + + if (unit_type >= PNG_RESOLUTION_LAST) + png_warning(png_ptr, "Unrecognized unit type for pHYs chunk"); + + png_save_uint_32(buf, x_pixels_per_unit); + png_save_uint_32(buf + 4, y_pixels_per_unit); + buf[8] = (png_byte)unit_type; + + png_write_complete_chunk(png_ptr, png_pHYs, buf, 9); +} +#endif + +#ifdef PNG_WRITE_tIME_SUPPORTED +/* Write the tIME chunk. Use either png_convert_from_struct_tm() + * or png_convert_from_time_t(), or fill in the structure yourself. + */ +void /* PRIVATE */ +png_write_tIME(png_structrp png_ptr, png_const_timep mod_time) +{ + png_byte buf[7]; + + png_debug(1, "in png_write_tIME"); + + if (mod_time->month > 12 || mod_time->month < 1 || + mod_time->day > 31 || mod_time->day < 1 || + mod_time->hour > 23 || mod_time->second > 60) + { + png_warning(png_ptr, "Invalid time specified for tIME chunk"); + return; + } + + png_save_uint_16(buf, mod_time->year); + buf[2] = mod_time->month; + buf[3] = mod_time->day; + buf[4] = mod_time->hour; + buf[5] = mod_time->minute; + buf[6] = mod_time->second; + + png_write_complete_chunk(png_ptr, png_tIME, buf, 7); +} +#endif + +#ifdef PNG_WRITE_APNG_SUPPORTED +void /* PRIVATE */ +png_write_acTL(png_structp png_ptr, + png_uint_32 num_frames, png_uint_32 num_plays) +{ + png_byte buf[8]; + + png_debug(1, "in png_write_acTL"); + + png_ptr->num_frames_to_write = num_frames; + + if ((png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN) != 0) + num_frames--; + + png_save_uint_32(buf, num_frames); + png_save_uint_32(buf + 4, num_plays); + + png_write_complete_chunk(png_ptr, png_acTL, buf, (png_size_t)8); +} + +void /* PRIVATE */ +png_write_fcTL(png_structp png_ptr, png_uint_32 width, png_uint_32 height, + png_uint_32 x_offset, png_uint_32 y_offset, + png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, + png_byte blend_op) +{ + png_byte buf[26]; + + png_debug(1, "in png_write_fcTL"); + + if (png_ptr->num_frames_written == 0 && (x_offset != 0 || y_offset != 0)) + png_error(png_ptr, "x and/or y offset for the first frame aren't 0"); + if (png_ptr->num_frames_written == 0 && + (width != png_ptr->first_frame_width || + height != png_ptr->first_frame_height)) + png_error(png_ptr, "width and/or height in the first frame's fcTL " + "don't match the ones in IHDR"); + + /* more error checking */ + png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset, + delay_num, delay_den, dispose_op, blend_op); + + png_save_uint_32(buf, png_ptr->next_seq_num); + png_save_uint_32(buf + 4, width); + png_save_uint_32(buf + 8, height); + png_save_uint_32(buf + 12, x_offset); + png_save_uint_32(buf + 16, y_offset); + png_save_uint_16(buf + 20, delay_num); + png_save_uint_16(buf + 22, delay_den); + buf[24] = dispose_op; + buf[25] = blend_op; + + png_write_complete_chunk(png_ptr, png_fcTL, buf, (png_size_t)26); + + png_ptr->next_seq_num++; +} + +void /* PRIVATE */ +png_write_fdAT(png_structp png_ptr, + png_const_bytep data, png_size_t length) +{ + png_byte buf[4]; + + png_write_chunk_header(png_ptr, png_fdAT, (png_uint_32)(4 + length)); + + png_save_uint_32(buf, png_ptr->next_seq_num); + png_write_chunk_data(png_ptr, buf, 4); + + png_write_chunk_data(png_ptr, data, length); + + png_write_chunk_end(png_ptr); + + png_ptr->next_seq_num++; +} +#endif /* WRITE_APNG */ + +/* Initializes the row writing capability of libpng */ +void /* PRIVATE */ +png_write_start_row(png_structrp png_ptr) +{ +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static const png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static const png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif + + png_alloc_size_t buf_size; + int usr_pixel_depth; + +#ifdef PNG_WRITE_FILTER_SUPPORTED + png_byte filters; +#endif + + png_debug(1, "in png_write_start_row"); + + usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth; + buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1; + + /* 1.5.6: added to allow checking in the row write code. */ + png_ptr->transformed_pixel_depth = png_ptr->pixel_depth; + png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth; + + /* Set up row buffer */ + png_ptr->row_buf = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size)); + + png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; + +#ifdef PNG_WRITE_FILTER_SUPPORTED + filters = png_ptr->do_filter; + + if (png_ptr->height == 1) + filters &= 0xff & ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); + + if (png_ptr->width == 1) + filters &= 0xff & ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH); + + if (filters == 0) + filters = PNG_FILTER_NONE; + + png_ptr->do_filter = filters; + + if (((filters & (PNG_FILTER_SUB | PNG_FILTER_UP | PNG_FILTER_AVG | + PNG_FILTER_PAETH)) != 0) && png_ptr->try_row == NULL) + { + int num_filters = 0; + + png_ptr->try_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size)); + + if (filters & PNG_FILTER_SUB) + num_filters++; + + if (filters & PNG_FILTER_UP) + num_filters++; + + if (filters & PNG_FILTER_AVG) + num_filters++; + + if (filters & PNG_FILTER_PAETH) + num_filters++; + + if (num_filters > 1) + png_ptr->tst_row = png_voidcast(png_bytep, png_malloc(png_ptr, + buf_size)); + } + + /* We only need to keep the previous row if we are using one of the following + * filters. + */ + if ((filters & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) != 0) + png_ptr->prev_row = png_voidcast(png_bytep, + png_calloc(png_ptr, buf_size)); +#endif /* WRITE_FILTER */ + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* If interlaced, we need to set up width and height of pass */ + if (png_ptr->interlaced != 0) + { + if ((png_ptr->transformations & PNG_INTERLACE) == 0) + { + png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - + png_pass_ystart[0]) / png_pass_yinc[0]; + + png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 - + png_pass_start[0]) / png_pass_inc[0]; + } + + else + { + png_ptr->num_rows = png_ptr->height; + png_ptr->usr_width = png_ptr->width; + } + } + + else +#endif + { + png_ptr->num_rows = png_ptr->height; + png_ptr->usr_width = png_ptr->width; + } +} + +/* Internal use only. Called when finished processing a row of data. */ +void /* PRIVATE */ +png_write_finish_row(png_structrp png_ptr) +{ +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static const png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static const png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif + + png_debug(1, "in png_write_finish_row"); + + /* Next row */ + png_ptr->row_number++; + + /* See if we are done */ + if (png_ptr->row_number < png_ptr->num_rows) + return; + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* If interlaced, go to next pass */ + if (png_ptr->interlaced != 0) + { + png_ptr->row_number = 0; + if ((png_ptr->transformations & PNG_INTERLACE) != 0) + { + png_ptr->pass++; + } + + else + { + /* Loop until we find a non-zero width or height pass */ + do + { + png_ptr->pass++; + + if (png_ptr->pass >= 7) + break; + + png_ptr->usr_width = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + + if ((png_ptr->transformations & PNG_INTERLACE) != 0) + break; + + } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0); + + } + + /* Reset the row above the image for the next pass */ + if (png_ptr->pass < 7) + { + if (png_ptr->prev_row != NULL) + memset(png_ptr->prev_row, 0, + PNG_ROWBYTES(png_ptr->usr_channels * + png_ptr->usr_bit_depth, png_ptr->width) + 1); + + return; + } + } +#endif + + /* If we get here, we've just written the last row, so we need + to flush the compressor */ + png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH); +} + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED +/* Pick out the correct pixels for the interlace pass. + * The basic idea here is to go through the row with a source + * pointer and a destination pointer (sp and dp), and copy the + * correct pixels for the pass. As the row gets compacted, + * sp will always be >= dp, so we should never overwrite anything. + * See the default: case for the easiest code to understand. + */ +void /* PRIVATE */ +png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) +{ + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + png_debug(1, "in png_do_write_interlace"); + + /* We don't have to do anything on the last pass (6) */ + if (pass < 6) + { + /* Each pixel depth is handled separately */ + switch (row_info->pixel_depth) + { + case 1: + { + png_bytep sp; + png_bytep dp; + unsigned int shift; + int d; + int value; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + dp = row; + d = 0; + shift = 7; + + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + sp = row + (size_t)(i >> 3); + value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01; + d |= (value << shift); + + if (shift == 0) + { + shift = 7; + *dp++ = (png_byte)d; + d = 0; + } + + else + shift--; + + } + if (shift != 7) + *dp = (png_byte)d; + + break; + } + + case 2: + { + png_bytep sp; + png_bytep dp; + unsigned int shift; + int d; + int value; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + dp = row; + shift = 6; + d = 0; + + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + sp = row + (size_t)(i >> 2); + value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03; + d |= (value << shift); + + if (shift == 0) + { + shift = 6; + *dp++ = (png_byte)d; + d = 0; + } + + else + shift -= 2; + } + if (shift != 6) + *dp = (png_byte)d; + + break; + } + + case 4: + { + png_bytep sp; + png_bytep dp; + unsigned int shift; + int d; + int value; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + dp = row; + shift = 4; + d = 0; + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + sp = row + (size_t)(i >> 1); + value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f; + d |= (value << shift); + + if (shift == 0) + { + shift = 4; + *dp++ = (png_byte)d; + d = 0; + } + + else + shift -= 4; + } + if (shift != 4) + *dp = (png_byte)d; + + break; + } + + default: + { + png_bytep sp; + png_bytep dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + size_t pixel_bytes; + + /* Start at the beginning */ + dp = row; + + /* Find out how many bytes each pixel takes up */ + pixel_bytes = (row_info->pixel_depth >> 3); + + /* Loop through the row, only looking at the pixels that matter */ + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + /* Find out where the original pixel is */ + sp = row + (size_t)i * pixel_bytes; + + /* Move the pixel */ + if (dp != sp) + memcpy(dp, sp, pixel_bytes); + + /* Next pixel */ + dp += pixel_bytes; + } + break; + } + } + /* Set new row width */ + row_info->width = (row_info->width + + png_pass_inc[pass] - 1 - + png_pass_start[pass]) / + png_pass_inc[pass]; + + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, + row_info->width); + } +} +#endif + + +/* This filters the row, chooses which filter to use, if it has not already + * been specified by the application, and then writes the row out with the + * chosen filter. + */ +static void /* PRIVATE */ +png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row, + size_t row_bytes); + +#ifdef PNG_WRITE_FILTER_SUPPORTED +static size_t /* PRIVATE */ +png_setup_sub_row(png_structrp png_ptr, png_uint_32 bpp, + size_t row_bytes, size_t lmins) +{ + png_bytep rp, dp, lp; + size_t i; + size_t sum = 0; + unsigned int v; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp; + i++, rp++, dp++) + { + v = *dp = *rp; +#ifdef PNG_USE_ABS + sum += 128 - abs((int)v - 128); +#else + sum += (v < 128) ? v : 256 - v; +#endif + } + + for (lp = png_ptr->row_buf + 1; i < row_bytes; + i++, rp++, lp++, dp++) + { + v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); +#ifdef PNG_USE_ABS + sum += 128 - abs((int)v - 128); +#else + sum += (v < 128) ? v : 256 - v; +#endif + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + + return (sum); +} + +static void /* PRIVATE */ +png_setup_sub_row_only(png_structrp png_ptr, png_uint_32 bpp, + size_t row_bytes) +{ + png_bytep rp, dp, lp; + size_t i; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp; + i++, rp++, dp++) + { + *dp = *rp; + } + + for (lp = png_ptr->row_buf + 1; i < row_bytes; + i++, rp++, lp++, dp++) + { + *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); + } +} + +static size_t /* PRIVATE */ +png_setup_up_row(png_structrp png_ptr, size_t row_bytes, size_t lmins) +{ + png_bytep rp, dp, pp; + size_t i; + size_t sum = 0; + unsigned int v; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_UP; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, + pp = png_ptr->prev_row + 1; i < row_bytes; + i++, rp++, pp++, dp++) + { + v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); +#ifdef PNG_USE_ABS + sum += 128 - abs((int)v - 128); +#else + sum += (v < 128) ? v : 256 - v; +#endif + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + + return (sum); +} +static void /* PRIVATE */ +png_setup_up_row_only(png_structrp png_ptr, size_t row_bytes) +{ + png_bytep rp, dp, pp; + size_t i; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_UP; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, + pp = png_ptr->prev_row + 1; i < row_bytes; + i++, rp++, pp++, dp++) + { + *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); + } +} + +static size_t /* PRIVATE */ +png_setup_avg_row(png_structrp png_ptr, png_uint_32 bpp, + size_t row_bytes, size_t lmins) +{ + png_bytep rp, dp, pp, lp; + png_uint_32 i; + size_t sum = 0; + unsigned int v; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, + pp = png_ptr->prev_row + 1; i < bpp; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); + +#ifdef PNG_USE_ABS + sum += 128 - abs((int)v - 128); +#else + sum += (v < 128) ? v : 256 - v; +#endif + } + + for (lp = png_ptr->row_buf + 1; i < row_bytes; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) + & 0xff); + +#ifdef PNG_USE_ABS + sum += 128 - abs((int)v - 128); +#else + sum += (v < 128) ? v : 256 - v; +#endif + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + + return (sum); +} +static void /* PRIVATE */ +png_setup_avg_row_only(png_structrp png_ptr, png_uint_32 bpp, + size_t row_bytes) +{ + png_bytep rp, dp, pp, lp; + png_uint_32 i; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, + pp = png_ptr->prev_row + 1; i < bpp; i++) + { + *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); + } + + for (lp = png_ptr->row_buf + 1; i < row_bytes; i++) + { + *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) + & 0xff); + } +} + +static size_t /* PRIVATE */ +png_setup_paeth_row(png_structrp png_ptr, png_uint_32 bpp, + size_t row_bytes, size_t lmins) +{ + png_bytep rp, dp, pp, cp, lp; + size_t i; + size_t sum = 0; + unsigned int v; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, + pp = png_ptr->prev_row + 1; i < bpp; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); + +#ifdef PNG_USE_ABS + sum += 128 - abs((int)v - 128); +#else + sum += (v < 128) ? v : 256 - v; +#endif + } + + for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes; + i++) + { + int a, b, c, pa, pb, pc, p; + + b = *pp++; + c = *cp++; + a = *lp++; + + p = b - c; + pc = a - c; + +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + + p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; + + v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); + +#ifdef PNG_USE_ABS + sum += 128 - abs((int)v - 128); +#else + sum += (v < 128) ? v : 256 - v; +#endif + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + + return (sum); +} +static void /* PRIVATE */ +png_setup_paeth_row_only(png_structrp png_ptr, png_uint_32 bpp, + size_t row_bytes) +{ + png_bytep rp, dp, pp, cp, lp; + size_t i; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, + pp = png_ptr->prev_row + 1; i < bpp; i++) + { + *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); + } + + for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes; + i++) + { + int a, b, c, pa, pb, pc, p; + + b = *pp++; + c = *cp++; + a = *lp++; + + p = b - c; + pc = a - c; + +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + + p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; + + *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); + } +} +#endif /* WRITE_FILTER */ + +void /* PRIVATE */ +png_write_find_filter(png_structrp png_ptr, png_row_infop row_info) +{ +#ifndef PNG_WRITE_FILTER_SUPPORTED + png_write_filtered_row(png_ptr, png_ptr->row_buf, row_info->rowbytes+1); +#else + unsigned int filter_to_do = png_ptr->do_filter; + png_bytep row_buf; + png_bytep best_row; + png_uint_32 bpp; + size_t mins; + size_t row_bytes = row_info->rowbytes; + + png_debug(1, "in png_write_find_filter"); + + /* Find out how many bytes offset each pixel is */ + bpp = (row_info->pixel_depth + 7) >> 3; + + row_buf = png_ptr->row_buf; + mins = PNG_SIZE_MAX - 256/* so we can detect potential overflow of the + running sum */; + + /* The prediction method we use is to find which method provides the + * smallest value when summing the absolute values of the distances + * from zero, using anything >= 128 as negative numbers. This is known + * as the "minimum sum of absolute differences" heuristic. Other + * heuristics are the "weighted minimum sum of absolute differences" + * (experimental and can in theory improve compression), and the "zlib + * predictive" method (not implemented yet), which does test compressions + * of lines using different filter methods, and then chooses the + * (series of) filter(s) that give minimum compressed data size (VERY + * computationally expensive). + * + * GRR 980525: consider also + * + * (1) minimum sum of absolute differences from running average (i.e., + * keep running sum of non-absolute differences & count of bytes) + * [track dispersion, too? restart average if dispersion too large?] + * + * (1b) minimum sum of absolute differences from sliding average, probably + * with window size <= deflate window (usually 32K) + * + * (2) minimum sum of squared differences from zero or running average + * (i.e., ~ root-mean-square approach) + */ + + + /* We don't need to test the 'no filter' case if this is the only filter + * that has been chosen, as it doesn't actually do anything to the data. + */ + best_row = png_ptr->row_buf; + + if (PNG_SIZE_MAX/128 <= row_bytes) + { + /* Overflow can occur in the calculation, just select the lowest set + * filter. + */ + filter_to_do &= 0U-filter_to_do; + } + else if ((filter_to_do & PNG_FILTER_NONE) != 0 && + filter_to_do != PNG_FILTER_NONE) + { + /* Overflow not possible and multiple filters in the list, including the + * 'none' filter. + */ + png_bytep rp; + size_t sum = 0; + size_t i; + unsigned int v; + + { + for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) + { + v = *rp; +#ifdef PNG_USE_ABS + sum += 128 - abs((int)v - 128); +#else + sum += (v < 128) ? v : 256 - v; +#endif + } + } + + mins = sum; + } + + /* Sub filter */ + if (filter_to_do == PNG_FILTER_SUB) + /* It's the only filter so no testing is needed */ + { + png_setup_sub_row_only(png_ptr, bpp, row_bytes); + best_row = png_ptr->try_row; + } + + else if ((filter_to_do & PNG_FILTER_SUB) != 0) + { + size_t sum; + size_t lmins = mins; + + sum = png_setup_sub_row(png_ptr, bpp, row_bytes, lmins); + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->try_row; + if (png_ptr->tst_row != NULL) + { + png_ptr->try_row = png_ptr->tst_row; + png_ptr->tst_row = best_row; + } + } + } + + /* Up filter */ + if (filter_to_do == PNG_FILTER_UP) + { + png_setup_up_row_only(png_ptr, row_bytes); + best_row = png_ptr->try_row; + } + + else if ((filter_to_do & PNG_FILTER_UP) != 0) + { + size_t sum; + size_t lmins = mins; + + sum = png_setup_up_row(png_ptr, row_bytes, lmins); + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->try_row; + if (png_ptr->tst_row != NULL) + { + png_ptr->try_row = png_ptr->tst_row; + png_ptr->tst_row = best_row; + } + } + } + + /* Avg filter */ + if (filter_to_do == PNG_FILTER_AVG) + { + png_setup_avg_row_only(png_ptr, bpp, row_bytes); + best_row = png_ptr->try_row; + } + + else if ((filter_to_do & PNG_FILTER_AVG) != 0) + { + size_t sum; + size_t lmins = mins; + + sum= png_setup_avg_row(png_ptr, bpp, row_bytes, lmins); + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->try_row; + if (png_ptr->tst_row != NULL) + { + png_ptr->try_row = png_ptr->tst_row; + png_ptr->tst_row = best_row; + } + } + } + + /* Paeth filter */ + if (filter_to_do == PNG_FILTER_PAETH) + { + png_setup_paeth_row_only(png_ptr, bpp, row_bytes); + best_row = png_ptr->try_row; + } + + else if ((filter_to_do & PNG_FILTER_PAETH) != 0) + { + size_t sum; + size_t lmins = mins; + + sum = png_setup_paeth_row(png_ptr, bpp, row_bytes, lmins); + + if (sum < mins) + { + best_row = png_ptr->try_row; + if (png_ptr->tst_row != NULL) + { + png_ptr->try_row = png_ptr->tst_row; + png_ptr->tst_row = best_row; + } + } + } + + /* Do the actual writing of the filtered row data from the chosen filter. */ + png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1); + +#endif /* WRITE_FILTER */ +} + + +/* Do the actual writing of a previously filtered row. */ +static void +png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row, + size_t full_row_length/*includes filter byte*/) +{ + png_debug(1, "in png_write_filtered_row"); + + png_debug1(2, "filter = %d", filtered_row[0]); + + png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH); + +#ifdef PNG_WRITE_FILTER_SUPPORTED + /* Swap the current and previous rows */ + if (png_ptr->prev_row != NULL) + { + png_bytep tptr; + + tptr = png_ptr->prev_row; + png_ptr->prev_row = png_ptr->row_buf; + png_ptr->row_buf = tptr; + } +#endif /* WRITE_FILTER */ + + /* Finish row - updates counters and flushes zlib if last row */ + png_write_finish_row(png_ptr); + +#ifdef PNG_WRITE_FLUSH_SUPPORTED + png_ptr->flush_rows++; + + if (png_ptr->flush_dist > 0 && + png_ptr->flush_rows >= png_ptr->flush_dist) + { + png_write_flush(png_ptr); + } +#endif /* WRITE_FLUSH */ +} + +#ifdef PNG_WRITE_APNG_SUPPORTED +void /* PRIVATE */ +png_write_reset(png_structp png_ptr) +{ + png_ptr->row_number = 0; + png_ptr->pass = 0; + png_ptr->mode &= ~PNG_HAVE_IDAT; +} + +void /* PRIVATE */ +png_write_reinit(png_structp png_ptr, png_infop info_ptr, + png_uint_32 width, png_uint_32 height) +{ + if (png_ptr->num_frames_written == 0 && + (width != png_ptr->first_frame_width || + height != png_ptr->first_frame_height)) + png_error(png_ptr, "width and/or height in the first frame's fcTL " + "don't match the ones in IHDR"); + if (width > png_ptr->first_frame_width || + height > png_ptr->first_frame_height) + png_error(png_ptr, "width and/or height for a frame greater than " + "the ones in IHDR"); + + png_set_IHDR(png_ptr, info_ptr, width, height, + info_ptr->bit_depth, info_ptr->color_type, + info_ptr->interlace_type, info_ptr->compression_type, + info_ptr->filter_type); + + png_ptr->width = width; + png_ptr->height = height; + png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width); + png_ptr->usr_width = png_ptr->width; +} +#endif /* WRITE_APNG */ +#endif /* WRITE */ diff --git a/media/libpng/powerpc/filter_vsx_intrinsics.c b/media/libpng/powerpc/filter_vsx_intrinsics.c new file mode 100644 index 0000000000..01cf8800dc --- /dev/null +++ b/media/libpng/powerpc/filter_vsx_intrinsics.c @@ -0,0 +1,768 @@ +/* filter_vsx_intrinsics.c - PowerPC optimised filter functions + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 2017 Glenn Randers-Pehrson + * Written by Vadim Barkov, 2017. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include <stdio.h> +#include <stdint.h> +#include "../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +/* This code requires -maltivec and -mvsx on the command line: */ +#if PNG_POWERPC_VSX_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */ + +#include <altivec.h> + +#if PNG_POWERPC_VSX_OPT > 0 + +#ifndef __VSX__ +# error "This code requires VSX support (POWER7 and later). Please provide -mvsx compiler flag." +#endif + +#define vec_ld_unaligned(vec,data) vec = vec_vsx_ld(0,data) +#define vec_st_unaligned(vec,data) vec_vsx_st(vec,0,data) + + +/* Functions in this file look at most 3 pixels (a,b,c) to predict the 4th (d). + * They're positioned like this: + * prev: c b + * row: a d + * The Sub filter predicts d=a, Avg d=(a+b)/2, and Paeth predicts d to be + * whichever of a, b, or c is closest to p=a+b-c. + * ( this is taken from ../intel/filter_sse2_intrinsics.c ) + */ + +#define vsx_declare_common_vars(row_info,row,prev_row,offset) \ + png_byte i;\ + png_bytep rp = row + offset;\ + png_const_bytep pp = prev_row;\ + size_t unaligned_top = 16 - (((size_t)rp % 16));\ + size_t istop;\ + if(unaligned_top == 16)\ + unaligned_top = 0;\ + istop = row_info->rowbytes;\ + if((unaligned_top < istop))\ + istop -= unaligned_top;\ + else{\ + unaligned_top = istop;\ + istop = 0;\ + } + +void png_read_filter_row_up_vsx(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + vector unsigned char rp_vec; + vector unsigned char pp_vec; + vsx_declare_common_vars(row_info,row,prev_row,0) + + /* Altivec operations require 16-byte aligned data + * but input can be unaligned. So we calculate + * unaligned part as usual. + */ + for (i = 0; i < unaligned_top; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); + rp++; + } + + /* Using SIMD while we can */ + while( istop >= 16 ) + { + rp_vec = vec_ld(0,rp); + vec_ld_unaligned(pp_vec,pp); + + rp_vec = vec_add(rp_vec,pp_vec); + + vec_st(rp_vec,0,rp); + + pp += 16; + rp += 16; + istop -= 16; + } + + if(istop > 0) + { + /* If byte count of row is not divisible by 16 + * we will process remaining part as usual + */ + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); + rp++; + } +} + +} + +static const vector unsigned char VSX_LEFTSHIFTED1_4 = {16,16,16,16, 0, 1, 2, 3,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_LEFTSHIFTED2_4 = {16,16,16,16,16,16,16,16, 4, 5, 6, 7,16,16,16,16}; +static const vector unsigned char VSX_LEFTSHIFTED3_4 = {16,16,16,16,16,16,16,16,16,16,16,16, 8, 9,10,11}; + +static const vector unsigned char VSX_LEFTSHIFTED1_3 = {16,16,16, 0, 1, 2,16,16,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_LEFTSHIFTED2_3 = {16,16,16,16,16,16, 3, 4, 5,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_LEFTSHIFTED3_3 = {16,16,16,16,16,16,16,16,16, 6, 7, 8,16,16,16,16}; +static const vector unsigned char VSX_LEFTSHIFTED4_3 = {16,16,16,16,16,16,16,16,16,16,16,16, 9,10,11,16}; + +static const vector unsigned char VSX_NOT_SHIFTED1_4 = {16,16,16,16, 4, 5, 6, 7,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_NOT_SHIFTED2_4 = {16,16,16,16,16,16,16,16, 8, 9,10,11,16,16,16,16}; +static const vector unsigned char VSX_NOT_SHIFTED3_4 = {16,16,16,16,16,16,16,16,16,16,16,16,12,13,14,15}; + +static const vector unsigned char VSX_NOT_SHIFTED1_3 = {16,16,16, 3, 4, 5,16,16,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_NOT_SHIFTED2_3 = {16,16,16,16,16,16, 6, 7, 8,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_NOT_SHIFTED3_3 = {16,16,16,16,16,16,16,16,16, 9,10,11,16,16,16,16}; +static const vector unsigned char VSX_NOT_SHIFTED4_3 = {16,16,16,16,16,16,16,16,16,16,16,16,12,13,14,16}; + +static const vector unsigned char VSX_CHAR_ZERO = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; +#ifdef __LITTLE_ENDIAN__ + +static const vector unsigned char VSX_CHAR_TO_SHORT1_4 = { 4,16, 5,16, 6,16, 7,16,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_CHAR_TO_SHORT2_4 = { 8,16, 9,16,10,16,11,16,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_CHAR_TO_SHORT3_4 = {12,16,13,16,14,16,15,16,16,16,16,16,16,16,16,16}; + +static const vector unsigned char VSX_SHORT_TO_CHAR1_4 = {16,16,16,16, 0, 2, 4, 6,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_SHORT_TO_CHAR2_4 = {16,16,16,16,16,16,16,16, 0, 2, 4, 6,16,16,16,16}; +static const vector unsigned char VSX_SHORT_TO_CHAR3_4 = {16,16,16,16,16,16,16,16,16,16,16,16, 0, 2, 4, 6}; + +static const vector unsigned char VSX_CHAR_TO_SHORT1_3 = { 3,16, 4,16, 5,16,16,16,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_CHAR_TO_SHORT2_3 = { 6,16, 7,16, 8,16,16,16,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_CHAR_TO_SHORT3_3 = { 9,16,10,16,11,16,16,16,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_CHAR_TO_SHORT4_3 = {12,16,13,16,14,16,16,16,16,16,16,16,16,16,16,16}; + +static const vector unsigned char VSX_SHORT_TO_CHAR1_3 = {16,16,16, 0, 2, 4,16,16,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_SHORT_TO_CHAR2_3 = {16,16,16,16,16,16, 0, 2, 4,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_SHORT_TO_CHAR3_3 = {16,16,16,16,16,16,16,16,16, 0, 2, 4,16,16,16,16}; +static const vector unsigned char VSX_SHORT_TO_CHAR4_3 = {16,16,16,16,16,16,16,16,16,16,16,16, 0, 2, 4,16}; + +#elif defined(__BIG_ENDIAN__) + +static const vector unsigned char VSX_CHAR_TO_SHORT1_4 = {16, 4,16, 5,16, 6,16, 7,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_CHAR_TO_SHORT2_4 = {16, 8,16, 9,16,10,16,11,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_CHAR_TO_SHORT3_4 = {16,12,16,13,16,14,16,15,16,16,16,16,16,16,16,16}; + +static const vector unsigned char VSX_SHORT_TO_CHAR1_4 = {16,16,16,16, 1, 3, 5, 7,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_SHORT_TO_CHAR2_4 = {16,16,16,16,16,16,16,16, 1, 3, 5, 7,16,16,16,16}; +static const vector unsigned char VSX_SHORT_TO_CHAR3_4 = {16,16,16,16,16,16,16,16,16,16,16,16, 1, 3, 5, 7}; + +static const vector unsigned char VSX_CHAR_TO_SHORT1_3 = {16, 3,16, 4,16, 5,16,16,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_CHAR_TO_SHORT2_3 = {16, 6,16, 7,16, 8,16,16,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_CHAR_TO_SHORT3_3 = {16, 9,16,10,16,11,16,16,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_CHAR_TO_SHORT4_3 = {16,12,16,13,16,14,16,16,16,16,16,16,16,16,16,16}; + +static const vector unsigned char VSX_SHORT_TO_CHAR1_3 = {16,16,16, 1, 3, 5,16,16,16,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_SHORT_TO_CHAR2_3 = {16,16,16,16,16,16, 1, 3, 5,16,16,16,16,16,16,16}; +static const vector unsigned char VSX_SHORT_TO_CHAR3_3 = {16,16,16,16,16,16,16,16,16, 1, 3, 5,16,16,16,16}; +static const vector unsigned char VSX_SHORT_TO_CHAR4_3 = {16,16,16,16,16,16,16,16,16,16,16,16, 1, 3, 5,16}; + +#endif + +#define vsx_char_to_short(vec,offset,bpp) (vector unsigned short)vec_perm((vec),VSX_CHAR_ZERO,VSX_CHAR_TO_SHORT##offset##_##bpp) +#define vsx_short_to_char(vec,offset,bpp) vec_perm(((vector unsigned char)(vec)),VSX_CHAR_ZERO,VSX_SHORT_TO_CHAR##offset##_##bpp) + +#ifdef PNG_USE_ABS +# define vsx_abs(number) abs(number) +#else +# define vsx_abs(number) (number > 0) ? (number) : -(number) +#endif + +void png_read_filter_row_sub4_vsx(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_byte bpp = 4; + + vector unsigned char rp_vec; + vector unsigned char part_vec; + + vsx_declare_common_vars(row_info,row,prev_row,bpp) + + PNG_UNUSED(pp) + + /* Altivec operations require 16-byte aligned data + * but input can be unaligned. So we calculate + * unaligned part as usual. + */ + for (i = 0; i < unaligned_top; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); + rp++; + } + + /* Using SIMD while we can */ + while( istop >= 16 ) + { + for(i=0;i < bpp ; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); + rp++; + } + rp -= bpp; + + rp_vec = vec_ld(0,rp); + part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED1_4); + rp_vec = vec_add(rp_vec,part_vec); + + part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED2_4); + rp_vec = vec_add(rp_vec,part_vec); + + part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED3_4); + rp_vec = vec_add(rp_vec,part_vec); + + vec_st(rp_vec,0,rp); + + rp += 16; + istop -= 16; + } + + if(istop > 0) + for (i = 0; i < istop % 16; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*(rp - bpp))) & 0xff); + rp++; + } + +} + +void png_read_filter_row_sub3_vsx(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_byte bpp = 3; + + vector unsigned char rp_vec; + vector unsigned char part_vec; + + vsx_declare_common_vars(row_info,row,prev_row,bpp) + + PNG_UNUSED(pp) + + /* Altivec operations require 16-byte aligned data + * but input can be unaligned. So we calculate + * unaligned part as usual. + */ + for (i = 0; i < unaligned_top; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); + rp++; + } + + /* Using SIMD while we can */ + while( istop >= 16 ) + { + for(i=0;i < bpp ; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); + rp++; + } + rp -= bpp; + + rp_vec = vec_ld(0,rp); + part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED1_3); + rp_vec = vec_add(rp_vec,part_vec); + + part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED2_3); + rp_vec = vec_add(rp_vec,part_vec); + + part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED3_3); + rp_vec = vec_add(rp_vec,part_vec); + + part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED4_3); + rp_vec = vec_add(rp_vec,part_vec); + + vec_st(rp_vec,0,rp); + rp += 15; + istop -= 16; + + /* Since 16 % bpp = 16 % 3 = 1, last element of array must + * be proceeded manually + */ + *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); + rp++; + } + + if(istop > 0) + for (i = 0; i < istop % 16; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); + rp++; + } +} + +void png_read_filter_row_avg4_vsx(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_byte bpp = 4; + + vector unsigned char rp_vec; + vector unsigned char pp_vec; + vector unsigned char pp_part_vec; + vector unsigned char rp_part_vec; + vector unsigned char avg_vec; + + vsx_declare_common_vars(row_info,row,prev_row,bpp) + rp -= bpp; + if(istop >= bpp) + istop -= bpp; + + for (i = 0; i < bpp; i++) + { + *rp = (png_byte)(((int)(*rp) + + ((int)(*pp++) / 2 )) & 0xff); + + rp++; + } + + /* Altivec operations require 16-byte aligned data + * but input can be unaligned. So we calculate + * unaligned part as usual. + */ + for (i = 0; i < unaligned_top; i++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); + + rp++; + } + + /* Using SIMD while we can */ + while( istop >= 16 ) + { + for(i=0;i < bpp ; i++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); + + rp++; + } + rp -= bpp; + pp -= bpp; + + vec_ld_unaligned(pp_vec,pp); + rp_vec = vec_ld(0,rp); + + rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED1_4); + pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED1_4); + avg_vec = vec_avg(rp_part_vec,pp_part_vec); + avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1))); + rp_vec = vec_add(rp_vec,avg_vec); + + rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED2_4); + pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED2_4); + avg_vec = vec_avg(rp_part_vec,pp_part_vec); + avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1))); + rp_vec = vec_add(rp_vec,avg_vec); + + rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED3_4); + pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED3_4); + avg_vec = vec_avg(rp_part_vec,pp_part_vec); + avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1))); + rp_vec = vec_add(rp_vec,avg_vec); + + vec_st(rp_vec,0,rp); + + rp += 16; + pp += 16; + istop -= 16; + } + + if(istop > 0) + for (i = 0; i < istop % 16; i++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); + + rp++; + } +} + +void png_read_filter_row_avg3_vsx(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_byte bpp = 3; + + vector unsigned char rp_vec; + vector unsigned char pp_vec; + vector unsigned char pp_part_vec; + vector unsigned char rp_part_vec; + vector unsigned char avg_vec; + + vsx_declare_common_vars(row_info,row,prev_row,bpp) + rp -= bpp; + if(istop >= bpp) + istop -= bpp; + + for (i = 0; i < bpp; i++) + { + *rp = (png_byte)(((int)(*rp) + + ((int)(*pp++) / 2 )) & 0xff); + + rp++; + } + + /* Altivec operations require 16-byte aligned data + * but input can be unaligned. So we calculate + * unaligned part as usual. + */ + for (i = 0; i < unaligned_top; i++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); + + rp++; + } + + /* Using SIMD while we can */ + while( istop >= 16 ) + { + for(i=0;i < bpp ; i++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); + + rp++; + } + rp -= bpp; + pp -= bpp; + + vec_ld_unaligned(pp_vec,pp); + rp_vec = vec_ld(0,rp); + + rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED1_3); + pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED1_3); + avg_vec = vec_avg(rp_part_vec,pp_part_vec); + avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1))); + rp_vec = vec_add(rp_vec,avg_vec); + + rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED2_3); + pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED2_3); + avg_vec = vec_avg(rp_part_vec,pp_part_vec); + avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1))); + rp_vec = vec_add(rp_vec,avg_vec); + + rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED3_3); + pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED3_3); + avg_vec = vec_avg(rp_part_vec,pp_part_vec); + avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1))); + rp_vec = vec_add(rp_vec,avg_vec); + + rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED4_3); + pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED4_3); + avg_vec = vec_avg(rp_part_vec,pp_part_vec); + avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1))); + rp_vec = vec_add(rp_vec,avg_vec); + + vec_st(rp_vec,0,rp); + + rp += 15; + pp += 15; + istop -= 16; + + /* Since 16 % bpp = 16 % 3 = 1, last element of array must + * be proceeded manually + */ + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); + rp++; + } + + if(istop > 0) + for (i = 0; i < istop % 16; i++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); + + rp++; + } +} + +/* Bytewise c ? t : e. */ +#define if_then_else(c,t,e) vec_sel(e,t,c) + +#define vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp) {\ + c = *(pp - bpp);\ + a = *(rp - bpp);\ + b = *pp++;\ + p = b - c;\ + pc = a - c;\ + pa = vsx_abs(p);\ + pb = vsx_abs(pc);\ + pc = vsx_abs(p + pc);\ + if (pb < pa) pa = pb, a = b;\ + if (pc < pa) a = c;\ + a += *rp;\ + *rp++ = (png_byte)a;\ + } + +void png_read_filter_row_paeth4_vsx(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_byte bpp = 4; + + int a, b, c, pa, pb, pc, p; + vector unsigned char rp_vec; + vector unsigned char pp_vec; + vector unsigned short a_vec,b_vec,c_vec,nearest_vec; + vector signed short pa_vec,pb_vec,pc_vec,smallest_vec; + + vsx_declare_common_vars(row_info,row,prev_row,bpp) + rp -= bpp; + if(istop >= bpp) + istop -= bpp; + + /* Process the first pixel in the row completely (this is the same as 'up' + * because there is only one candidate predictor for the first row). + */ + for(i = 0; i < bpp ; i++) + { + *rp = (png_byte)( *rp + *pp); + rp++; + pp++; + } + + for(i = 0; i < unaligned_top ; i++) + { + vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp) + } + + while( istop >= 16) + { + for(i = 0; i < bpp ; i++) + { + vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp) + } + + rp -= bpp; + pp -= bpp; + rp_vec = vec_ld(0,rp); + vec_ld_unaligned(pp_vec,pp); + + a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED1_4),1,4); + b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED1_4),1,4); + c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED1_4),1,4); + pa_vec = (vector signed short) vec_sub(b_vec,c_vec); + pb_vec = (vector signed short) vec_sub(a_vec , c_vec); + pc_vec = vec_add(pa_vec,pb_vec); + pa_vec = vec_abs(pa_vec); + pb_vec = vec_abs(pb_vec); + pc_vec = vec_abs(pc_vec); + smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec)); + nearest_vec = if_then_else( + vec_cmpeq(pa_vec,smallest_vec), + a_vec, + if_then_else( + vec_cmpeq(pb_vec,smallest_vec), + b_vec, + c_vec + ) + ); + rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,1,4))); + + a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED2_4),2,4); + b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED2_4),2,4); + c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED2_4),2,4); + pa_vec = (vector signed short) vec_sub(b_vec,c_vec); + pb_vec = (vector signed short) vec_sub(a_vec , c_vec); + pc_vec = vec_add(pa_vec,pb_vec); + pa_vec = vec_abs(pa_vec); + pb_vec = vec_abs(pb_vec); + pc_vec = vec_abs(pc_vec); + smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec)); + nearest_vec = if_then_else( + vec_cmpeq(pa_vec,smallest_vec), + a_vec, + if_then_else( + vec_cmpeq(pb_vec,smallest_vec), + b_vec, + c_vec + ) + ); + rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,2,4))); + + a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED3_4),3,4); + b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED3_4),3,4); + c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED3_4),3,4); + pa_vec = (vector signed short) vec_sub(b_vec,c_vec); + pb_vec = (vector signed short) vec_sub(a_vec , c_vec); + pc_vec = vec_add(pa_vec,pb_vec); + pa_vec = vec_abs(pa_vec); + pb_vec = vec_abs(pb_vec); + pc_vec = vec_abs(pc_vec); + smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec)); + nearest_vec = if_then_else( + vec_cmpeq(pa_vec,smallest_vec), + a_vec, + if_then_else( + vec_cmpeq(pb_vec,smallest_vec), + b_vec, + c_vec + ) + ); + rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,3,4))); + + vec_st(rp_vec,0,rp); + + rp += 16; + pp += 16; + istop -= 16; + } + + if(istop > 0) + for (i = 0; i < istop % 16; i++) + { + vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp) + } +} + +void png_read_filter_row_paeth3_vsx(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_byte bpp = 3; + + int a, b, c, pa, pb, pc, p; + vector unsigned char rp_vec; + vector unsigned char pp_vec; + vector unsigned short a_vec,b_vec,c_vec,nearest_vec; + vector signed short pa_vec,pb_vec,pc_vec,smallest_vec; + + vsx_declare_common_vars(row_info,row,prev_row,bpp) + rp -= bpp; + if(istop >= bpp) + istop -= bpp; + + /* Process the first pixel in the row completely (this is the same as 'up' + * because there is only one candidate predictor for the first row). + */ + for(i = 0; i < bpp ; i++) + { + *rp = (png_byte)( *rp + *pp); + rp++; + pp++; + } + + for(i = 0; i < unaligned_top ; i++) + { + vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp) + } + + while( istop >= 16) + { + for(i = 0; i < bpp ; i++) + { + vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp) + } + + rp -= bpp; + pp -= bpp; + rp_vec = vec_ld(0,rp); + vec_ld_unaligned(pp_vec,pp); + + a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED1_3),1,3); + b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED1_3),1,3); + c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED1_3),1,3); + pa_vec = (vector signed short) vec_sub(b_vec,c_vec); + pb_vec = (vector signed short) vec_sub(a_vec , c_vec); + pc_vec = vec_add(pa_vec,pb_vec); + pa_vec = vec_abs(pa_vec); + pb_vec = vec_abs(pb_vec); + pc_vec = vec_abs(pc_vec); + smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec)); + nearest_vec = if_then_else( + vec_cmpeq(pa_vec,smallest_vec), + a_vec, + if_then_else( + vec_cmpeq(pb_vec,smallest_vec), + b_vec, + c_vec + ) + ); + rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,1,3))); + + a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED2_3),2,3); + b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED2_3),2,3); + c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED2_3),2,3); + pa_vec = (vector signed short) vec_sub(b_vec,c_vec); + pb_vec = (vector signed short) vec_sub(a_vec , c_vec); + pc_vec = vec_add(pa_vec,pb_vec); + pa_vec = vec_abs(pa_vec); + pb_vec = vec_abs(pb_vec); + pc_vec = vec_abs(pc_vec); + smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec)); + nearest_vec = if_then_else( + vec_cmpeq(pa_vec,smallest_vec), + a_vec, + if_then_else( + vec_cmpeq(pb_vec,smallest_vec), + b_vec, + c_vec + ) + ); + rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,2,3))); + + a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED3_3),3,3); + b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED3_3),3,3); + c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED3_3),3,3); + pa_vec = (vector signed short) vec_sub(b_vec,c_vec); + pb_vec = (vector signed short) vec_sub(a_vec , c_vec); + pc_vec = vec_add(pa_vec,pb_vec); + pa_vec = vec_abs(pa_vec); + pb_vec = vec_abs(pb_vec); + pc_vec = vec_abs(pc_vec); + smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec)); + nearest_vec = if_then_else( + vec_cmpeq(pa_vec,smallest_vec), + a_vec, + if_then_else( + vec_cmpeq(pb_vec,smallest_vec), + b_vec, + c_vec + ) + ); + rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,3,3))); + + a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED4_3),4,3); + b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED4_3),4,3); + c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED4_3),4,3); + pa_vec = (vector signed short) vec_sub(b_vec,c_vec); + pb_vec = (vector signed short) vec_sub(a_vec , c_vec); + pc_vec = vec_add(pa_vec,pb_vec); + pa_vec = vec_abs(pa_vec); + pb_vec = vec_abs(pb_vec); + pc_vec = vec_abs(pc_vec); + smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec)); + nearest_vec = if_then_else( + vec_cmpeq(pa_vec,smallest_vec), + a_vec, + if_then_else( + vec_cmpeq(pb_vec,smallest_vec), + b_vec, + c_vec + ) + ); + rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,4,3))); + + vec_st(rp_vec,0,rp); + + rp += 15; + pp += 15; + istop -= 16; + + /* Since 16 % bpp = 16 % 3 = 1, last element of array must + * be proceeded manually + */ + vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp) + } + + if(istop > 0) + for (i = 0; i < istop % 16; i++) + { + vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp) + } +} + +#endif /* PNG_POWERPC_VSX_OPT > 0 */ +#endif /* PNG_POWERPC_VSX_IMPLEMENTATION == 1 (intrinsics) */ +#endif /* READ */ diff --git a/media/libpng/powerpc/powerpc_init.c b/media/libpng/powerpc/powerpc_init.c new file mode 100644 index 0000000000..54426c558e --- /dev/null +++ b/media/libpng/powerpc/powerpc_init.c @@ -0,0 +1,126 @@ + +/* powerpc_init.c - POWERPC optimised filter functions + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 2017 Glenn Randers-Pehrson + * Written by Vadim Barkov, 2017. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are + * called. + */ +#define _POSIX_SOURCE 1 + +#include <stdio.h> +#include "../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +#if PNG_POWERPC_VSX_OPT > 0 +#ifdef PNG_POWERPC_VSX_CHECK_SUPPORTED /* Do run-time checks */ +/* WARNING: it is strongly recommended that you do not build libpng with + * run-time checks for CPU features if at all possible. In the case of the PowerPC + * VSX instructions there is no processor-specific way of detecting the + * presence of the required support, therefore run-time detection is extremely + * OS specific. + * + * You may set the macro PNG_POWERPC_VSX_FILE to the file name of file containing + * a fragment of C source code which defines the png_have_vsx function. There + * are a number of implementations in contrib/powerpc-vsx, but the only one that + * has partial support is contrib/powerpc-vsx/linux.c - a generic Linux + * implementation which reads /proc/cpufino. + */ +#ifndef PNG_POWERPC_VSX_FILE +# ifdef __linux__ +# define PNG_POWERPC_VSX_FILE "contrib/powerpc-vsx/linux_aux.c" +# endif +#endif + +#ifdef PNG_POWERPC_VSX_FILE + +#include <signal.h> /* for sig_atomic_t */ +static int png_have_vsx(png_structp png_ptr); +#include PNG_POWERPC_VSX_FILE + +#else /* PNG_POWERPC_VSX_FILE */ +# error "PNG_POWERPC_VSX_FILE undefined: no support for run-time POWERPC VSX checks" +#endif /* PNG_POWERPC_VSX_FILE */ +#endif /* PNG_POWERPC_VSX_CHECK_SUPPORTED */ + +void +png_init_filter_functions_vsx(png_structp pp, unsigned int bpp) +{ + /* The switch statement is compiled in for POWERPC_VSX_API, the call to + * png_have_vsx is compiled in for POWERPC_VSX_CHECK. If both are defined + * the check is only performed if the API has not set the PowerPC option on + * or off explicitly. In this case the check controls what happens. + */ + +#ifdef PNG_POWERPC_VSX_API_SUPPORTED + switch ((pp->options >> PNG_POWERPC_VSX) & 3) + { + case PNG_OPTION_UNSET: + /* Allow the run-time check to execute if it has been enabled - + * thus both API and CHECK can be turned on. If it isn't supported + * this case will fall through to the 'default' below, which just + * returns. + */ +#endif /* PNG_POWERPC_VSX_API_SUPPORTED */ +#ifdef PNG_POWERPC_VSX_CHECK_SUPPORTED + { + static volatile sig_atomic_t no_vsx = -1; /* not checked */ + + if (no_vsx < 0) + no_vsx = !png_have_vsx(pp); + + if (no_vsx) + return; + } +#ifdef PNG_POWERPC_VSX_API_SUPPORTED + break; +#endif +#endif /* PNG_POWERPC_VSX_CHECK_SUPPORTED */ + +#ifdef PNG_POWERPC_VSX_API_SUPPORTED + default: /* OFF or INVALID */ + return; + + case PNG_OPTION_ON: + /* Option turned on */ + break; + } +#endif + + /* IMPORTANT: any new internal functions used here must be declared using + * PNG_INTERNAL_FUNCTION in ../pngpriv.h. This is required so that the + * 'prefix' option to configure works: + * + * ./configure --with-libpng-prefix=foobar_ + * + * Verify you have got this right by running the above command, doing a build + * and examining pngprefix.h; it must contain a #define for every external + * function you add. (Notice that this happens automatically for the + * initialization function.) + */ + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_vsx; + + if (bpp == 3) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_vsx; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_vsx; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth3_vsx; + } + + else if (bpp == 4) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_vsx; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_vsx; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth4_vsx; + } +} +#endif /* PNG_POWERPC_VSX_OPT > 0 */ +#endif /* READ */ |