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+2.1.4
+=====
+
+### Significant changes relative to 2.1.3
+
+1. Fixed a regression introduced in 2.1.3 that caused build failures with
+Visual Studio 2010.
+
+2. The `tjDecompressHeader3()` function in the TurboJPEG C API and the
+`TJDecompressor.setSourceImage()` method in the TurboJPEG Java API now accept
+"abbreviated table specification" (AKA "tables-only") datastreams, which can be
+used to prime the decompressor with quantization and Huffman tables that can be
+used when decompressing subsequent "abbreviated image" datastreams.
+
+3. libjpeg-turbo now performs run-time detection of AltiVec instructions on
+OS X/PowerPC systems if AltiVec instructions are not enabled at compile time.
+This allows both AltiVec-equipped (PowerPC G4 and G5) and non-AltiVec-equipped
+(PowerPC G3) CPUs to be supported using the same build of libjpeg-turbo.
+
+4. Fixed an error ("Bogus virtual array access") that occurred when attempting
+to decompress a progressive JPEG image with a height less than or equal to one
+iMCU (8 * the vertical sampling factor) using buffered-image mode with
+interblock smoothing enabled. This was a regression introduced by
+2.1 beta1[6(b)].
+
+5. Fixed two issues that prevented partial image decompression from working
+properly with buffered-image mode:
+
+ - Attempting to call `jpeg_crop_scanline()` after
+`jpeg_start_decompress()` but before `jpeg_start_output()` resulted in an error
+("Improper call to JPEG library in state 207".)
+ - Attempting to use `jpeg_skip_scanlines()` resulted in an error ("Bogus
+virtual array access") under certain circumstances.
+
+
+2.1.3
+=====
+
+### Significant changes relative to 2.1.2
+
+1. Fixed a regression introduced by 2.0 beta1[7] whereby cjpeg compressed PGM
+input files into full-color JPEG images unless the `-grayscale` option was
+used.
+
+2. cjpeg now automatically compresses GIF and 8-bit BMP input files into
+grayscale JPEG images if the input files contain only shades of gray.
+
+3. The build system now enables the intrinsics implementation of the AArch64
+(Arm 64-bit) Neon SIMD extensions by default when using GCC 12 or later.
+
+4. Fixed a segfault that occurred while decompressing a 4:2:0 JPEG image using
+the merged (non-fancy) upsampling algorithms (that is, with
+`cinfo.do_fancy_upsampling` set to `FALSE`) along with `jpeg_crop_scanline()`.
+Specifically, the segfault occurred if the number of bytes remaining in the
+output buffer was less than the number of bytes required to represent one
+uncropped scanline of the output image. For that reason, the issue could only
+be reproduced using the libjpeg API, not using djpeg.
+
+
+2.1.2
+=====
+
+### Significant changes relative to 2.1.1
+
+1. Fixed a regression introduced by 2.1 beta1[13] that caused the remaining
+GAS implementations of AArch64 (Arm 64-bit) Neon SIMD functions (which are used
+by default with GCC for performance reasons) to be placed in the `.rodata`
+section rather than in the `.text` section. This caused the GNU linker to
+automatically place the `.rodata` section in an executable segment, which
+prevented libjpeg-turbo from working properly with other linkers and also
+represented a potential security risk.
+
+2. Fixed an issue whereby the `tjTransform()` function incorrectly computed the
+MCU block size for 4:4:4 JPEG images with non-unary sampling factors and thus
+unduly rejected some cropping regions, even though those regions aligned with
+8x8 MCU block boundaries.
+
+3. Fixed a regression introduced by 2.1 beta1[13] that caused the build system
+to enable the Arm Neon SIMD extensions when targetting Armv6 and other legacy
+architectures that do not support Neon instructions.
+
+4. libjpeg-turbo now performs run-time detection of AltiVec instructions on
+FreeBSD/PowerPC systems if AltiVec instructions are not enabled at compile
+time. This allows both AltiVec-equipped and non-AltiVec-equipped CPUs to be
+supported using the same build of libjpeg-turbo.
+
+5. cjpeg now accepts a `-strict` argument similar to that of djpeg and
+jpegtran, which causes the compressor to abort if an LZW-compressed GIF input
+image contains incomplete or corrupt image data.
+
+
+2.1.1
+=====
+
+### Significant changes relative to 2.1.0
+
+1. Fixed a regression introduced in 2.1.0 that caused build failures with
+non-GCC-compatible compilers for Un*x/Arm platforms.
+
+2. Fixed a regression introduced by 2.1 beta1[13] that prevented the Arm 32-bit
+(AArch32) Neon SIMD extensions from building unless the C compiler flags
+included `-mfloat-abi=softfp` or `-mfloat-abi=hard`.
+
+3. Fixed an issue in the AArch32 Neon SIMD Huffman encoder whereby reliance on
+undefined C compiler behavior led to crashes ("SIGBUS: illegal alignment") on
+Android systems when running AArch32/Thumb builds of libjpeg-turbo built with
+recent versions of Clang.
+
+4. Added a command-line argument (`-copy icc`) to jpegtran that causes it to
+copy only the ICC profile markers from the source file and discard any other
+metadata.
+
+5. libjpeg-turbo should now build and run on CHERI-enabled architectures, which
+use capability pointers that are larger than the size of `size_t`.
+
+6. Fixed a regression (CVE-2021-37972) introduced by 2.1 beta1[5] that caused a
+segfault in the 64-bit SSE2 Huffman encoder when attempting to losslessly
+transform a specially-crafted malformed JPEG image.
+
+
+2.1.0
+=====
+
+### Significant changes relative to 2.1 beta1
+
+1. Fixed a regression introduced by 2.1 beta1[6(b)] whereby attempting to
+decompress certain progressive JPEG images with one or more component planes of
+width 8 or less caused a buffer overrun.
+
+2. Fixed a regression introduced by 2.1 beta1[6(b)] whereby attempting to
+decompress a specially-crafted malformed progressive JPEG image caused the
+block smoothing algorithm to read from uninitialized memory.
+
+3. Fixed an issue in the Arm Neon SIMD Huffman encoders that caused the
+encoders to generate incorrect results when using the Clang compiler with
+Visual Studio.
+
+4. Fixed a floating point exception (CVE-2021-20205) that occurred when
+attempting to compress a specially-crafted malformed GIF image with a specified
+image width of 0 using cjpeg.
+
+5. Fixed a regression introduced by 2.0 beta1[15] whereby attempting to
+generate a progressive JPEG image on an SSE2-capable CPU using a scan script
+containing one or more scans with lengths divisible by 32 and non-zero
+successive approximation low bit positions would, under certain circumstances,
+result in an error ("Missing Huffman code table entry") and an invalid JPEG
+image.
+
+6. Introduced a new flag (`TJFLAG_LIMITSCANS` in the TurboJPEG C API and
+`TJ.FLAG_LIMIT_SCANS` in the TurboJPEG Java API) and a corresponding TJBench
+command-line argument (`-limitscans`) that causes the TurboJPEG decompression
+and transform functions/operations to return/throw an error if a progressive
+JPEG image contains an unreasonably large number of scans. This allows
+applications that use the TurboJPEG API to guard against an exploit of the
+progressive JPEG format described in the report
+["Two Issues with the JPEG Standard"](https://libjpeg-turbo.org/pmwiki/uploads/About/TwoIssueswiththeJPEGStandard.pdf).
+
+7. The PPM reader now throws an error, rather than segfaulting (due to a buffer
+overrun) or generating incorrect pixels, if an application attempts to use the
+`tjLoadImage()` function to load a 16-bit binary PPM file (a binary PPM file
+with a maximum value greater than 255) into a grayscale image buffer or to load
+a 16-bit binary PGM file into an RGB image buffer.
+
+8. Fixed an issue in the PPM reader that caused incorrect pixels to be
+generated when using the `tjLoadImage()` function to load a 16-bit binary PPM
+file into an extended RGB image buffer.
+
+9. Fixed an issue whereby, if a JPEG buffer was automatically re-allocated by
+one of the TurboJPEG compression or transform functions and an error
+subsequently occurred during compression or transformation, the JPEG buffer
+pointer passed by the application was not updated when the function returned.
+
+
+2.0.90 (2.1 beta1)
+==================
+
+### Significant changes relative to 2.0.6:
+
+1. The build system, x86-64 SIMD extensions, and accelerated Huffman codec now
+support the x32 ABI on Linux, which allows for using x86-64 instructions with
+32-bit pointers. The x32 ABI is generally enabled by adding `-mx32` to the
+compiler flags.
+
+ Caveats:
+ - CMake 3.9.0 or later is required in order for the build system to
+automatically detect an x32 build.
+ - Java does not support the x32 ABI, and thus the TurboJPEG Java API will
+automatically be disabled with x32 builds.
+
+2. Added Loongson MMI SIMD implementations of the RGB-to-grayscale, 4:2:2 fancy
+chroma upsampling, 4:2:2 and 4:2:0 merged chroma upsampling/color conversion,
+and fast integer DCT/IDCT algorithms. Relative to libjpeg-turbo 2.0.x, this
+speeds up:
+
+ - the compression of RGB source images into grayscale JPEG images by
+approximately 20%
+ - the decompression of 4:2:2 JPEG images by approximately 40-60% when
+using fancy upsampling
+ - the decompression of 4:2:2 and 4:2:0 JPEG images by approximately
+15-20% when using merged upsampling
+ - the compression of RGB source images by approximately 30-45% when using
+the fast integer DCT
+ - the decompression of JPEG images into RGB destination images by
+approximately 2x when using the fast integer IDCT
+
+ The overall decompression speedup for RGB images is now approximately
+2.3-3.7x (compared to 2-3.5x with libjpeg-turbo 2.0.x.)
+
+3. 32-bit (Armv7 or Armv7s) iOS builds of libjpeg-turbo are no longer
+supported, and the libjpeg-turbo build system can no longer be used to package
+such builds. 32-bit iOS apps cannot run in iOS 11 and later, and the App Store
+no longer allows them.
+
+4. 32-bit (i386) OS X/macOS builds of libjpeg-turbo are no longer supported,
+and the libjpeg-turbo build system can no longer be used to package such
+builds. 32-bit Mac applications cannot run in macOS 10.15 "Catalina" and
+later, and the App Store no longer allows them.
+
+5. The SSE2 (x86 SIMD) and C Huffman encoding algorithms have been
+significantly optimized, resulting in a measured average overall compression
+speedup of 12-28% for 64-bit code and 22-52% for 32-bit code on various Intel
+and AMD CPUs, as well as a measured average overall compression speedup of
+0-23% on platforms that do not have a SIMD-accelerated Huffman encoding
+implementation.
+
+6. The block smoothing algorithm that is applied by default when decompressing
+progressive Huffman-encoded JPEG images has been improved in the following
+ways:
+
+ - The algorithm is now more fault-tolerant. Previously, if a particular
+scan was incomplete, then the smoothing parameters for the incomplete scan
+would be applied to the entire output image, including the parts of the image
+that were generated by the prior (complete) scan. Visually, this had the
+effect of removing block smoothing from lower-frequency scans if they were
+followed by an incomplete higher-frequency scan. libjpeg-turbo now applies
+block smoothing parameters to each iMCU row based on which scan generated the
+pixels in that row, rather than always using the block smoothing parameters for
+the most recent scan.
+ - When applying block smoothing to DC scans, a Gaussian-like kernel with a
+5x5 window is used to reduce the "blocky" appearance.
+
+7. Added SIMD acceleration for progressive Huffman encoding on Arm platforms.
+This speeds up the compression of full-color progressive JPEGs by about 30-40%
+on average (relative to libjpeg-turbo 2.0.x) when using modern Arm CPUs.
+
+8. Added configure-time and run-time auto-detection of Loongson MMI SIMD
+instructions, so that the Loongson MMI SIMD extensions can be included in any
+MIPS64 libjpeg-turbo build.
+
+9. Added fault tolerance features to djpeg and jpegtran, mainly to demonstrate
+methods by which applications can guard against the exploits of the JPEG format
+described in the report
+["Two Issues with the JPEG Standard"](https://libjpeg-turbo.org/pmwiki/uploads/About/TwoIssueswiththeJPEGStandard.pdf).
+
+ - Both programs now accept a `-maxscans` argument, which can be used to
+limit the number of allowable scans in the input file.
+ - Both programs now accept a `-strict` argument, which can be used to
+treat all warnings as fatal.
+
+10. CMake package config files are now included for both the libjpeg and
+TurboJPEG API libraries. This facilitates using libjpeg-turbo with CMake's
+`find_package()` function. For example:
+
+ find_package(libjpeg-turbo CONFIG REQUIRED)
+
+ add_executable(libjpeg_program libjpeg_program.c)
+ target_link_libraries(libjpeg_program PUBLIC libjpeg-turbo::jpeg)
+
+ add_executable(libjpeg_program_static libjpeg_program.c)
+ target_link_libraries(libjpeg_program_static PUBLIC
+ libjpeg-turbo::jpeg-static)
+
+ add_executable(turbojpeg_program turbojpeg_program.c)
+ target_link_libraries(turbojpeg_program PUBLIC
+ libjpeg-turbo::turbojpeg)
+
+ add_executable(turbojpeg_program_static turbojpeg_program.c)
+ target_link_libraries(turbojpeg_program_static PUBLIC
+ libjpeg-turbo::turbojpeg-static)
+
+11. Since the Unisys LZW patent has long expired, cjpeg and djpeg can now
+read/write both LZW-compressed and uncompressed GIF files (feature ported from
+jpeg-6a and jpeg-9d.)
+
+12. jpegtran now includes the `-wipe` and `-drop` options from jpeg-9a and
+jpeg-9d, as well as the ability to expand the image size using the `-crop`
+option. Refer to jpegtran.1 or usage.txt for more details.
+
+13. Added a complete intrinsics implementation of the Arm Neon SIMD extensions,
+thus providing SIMD acceleration on Arm platforms for all of the algorithms
+that are SIMD-accelerated on x86 platforms. This new implementation is
+significantly faster in some cases than the old GAS implementation--
+depending on the algorithms used, the type of CPU core, and the compiler. GCC,
+as of this writing, does not provide a full or optimal set of Neon intrinsics,
+so for performance reasons, the default when building libjpeg-turbo with GCC is
+to continue using the GAS implementation of the following algorithms:
+
+ - 32-bit RGB-to-YCbCr color conversion
+ - 32-bit fast and accurate inverse DCT
+ - 64-bit RGB-to-YCbCr and YCbCr-to-RGB color conversion
+ - 64-bit accurate forward and inverse DCT
+ - 64-bit Huffman encoding
+
+ A new CMake variable (`NEON_INTRINSICS`) can be used to override this
+default.
+
+ Since the new intrinsics implementation includes SIMD acceleration
+for merged upsampling/color conversion, 1.5.1[5] is no longer necessary and has
+been reverted.
+
+14. The Arm Neon SIMD extensions can now be built using Visual Studio.
+
+15. The build system can now be used to generate a universal x86-64 + Armv8
+libjpeg-turbo SDK package for both iOS and macOS.
+
+
+2.0.6
+=====
+
+### Significant changes relative to 2.0.5:
+
+1. Fixed "using JNI after critical get" errors that occurred on Android
+platforms when using any of the YUV encoding/compression/decompression/decoding
+methods in the TurboJPEG Java API.
+
+2. Fixed or worked around multiple issues with `jpeg_skip_scanlines()`:
+
+ - Fixed segfaults or "Corrupt JPEG data: premature end of data segment"
+errors in `jpeg_skip_scanlines()` that occurred when decompressing 4:2:2 or
+4:2:0 JPEG images using merged (non-fancy) upsampling/color conversion (that
+is, when setting `cinfo.do_fancy_upsampling` to `FALSE`.) 2.0.0[6] was a
+similar fix, but it did not cover all cases.
+ - `jpeg_skip_scanlines()` now throws an error if two-pass color
+quantization is enabled. Two-pass color quantization never worked properly
+with `jpeg_skip_scanlines()`, and the issues could not readily be fixed.
+ - Fixed an issue whereby `jpeg_skip_scanlines()` always returned 0 when
+skipping past the end of an image.
+
+3. The Arm 64-bit (Armv8) Neon SIMD extensions can now be built using MinGW
+toolchains targetting Arm64 (AArch64) Windows binaries.
+
+4. Fixed unexpected visual artifacts that occurred when using
+`jpeg_crop_scanline()` and interblock smoothing while decompressing only the DC
+scan of a progressive JPEG image.
+
+5. Fixed an issue whereby libjpeg-turbo would not build if 12-bit-per-component
+JPEG support (`WITH_12BIT`) was enabled along with libjpeg v7 or libjpeg v8
+API/ABI emulation (`WITH_JPEG7` or `WITH_JPEG8`.)
+
+
+2.0.5
+=====
+
+### Significant changes relative to 2.0.4:
+
+1. Worked around issues in the MIPS DSPr2 SIMD extensions that caused failures
+in the libjpeg-turbo regression tests. Specifically, the
+`jsimd_h2v1_downsample_dspr2()` and `jsimd_h2v2_downsample_dspr2()` functions
+in the MIPS DSPr2 SIMD extensions are now disabled until/unless they can be
+fixed, and other functions that are incompatible with big endian MIPS CPUs are
+disabled when building libjpeg-turbo for such CPUs.
+
+2. Fixed an oversight in the `TJCompressor.compress(int)` method in the
+TurboJPEG Java API that caused an error ("java.lang.IllegalStateException: No
+source image is associated with this instance") when attempting to use that
+method to compress a YUV image.
+
+3. Fixed an issue (CVE-2020-13790) in the PPM reader that caused a buffer
+overrun in cjpeg, TJBench, or the `tjLoadImage()` function if one of the values
+in a binary PPM/PGM input file exceeded the maximum value defined in the file's
+header and that maximum value was less than 255. libjpeg-turbo 1.5.0 already
+included a similar fix for binary PPM/PGM files with maximum values greater
+than 255.
+
+4. The TurboJPEG API library's global error handler, which is used in functions
+such as `tjBufSize()` and `tjLoadImage()` that do not require a TurboJPEG
+instance handle, is now thread-safe on platforms that support thread-local
+storage.
+
+
+2.0.4
+=====
+
+### Significant changes relative to 2.0.3:
+
+1. Fixed a regression in the Windows packaging system (introduced by
+2.0 beta1[2]) whereby, if both the 64-bit libjpeg-turbo SDK for GCC and the
+64-bit libjpeg-turbo SDK for Visual C++ were installed on the same system, only
+one of them could be uninstalled.
+
+2. Fixed a signed integer overflow and subsequent segfault that occurred when
+attempting to decompress images with more than 715827882 pixels using the
+64-bit C version of TJBench.
+
+3. Fixed out-of-bounds write in `tjDecompressToYUV2()` and
+`tjDecompressToYUVPlanes()` (sometimes manifesting as a double free) that
+occurred when attempting to decompress grayscale JPEG images that were
+compressed with a sampling factor other than 1 (for instance, with
+`cjpeg -grayscale -sample 2x2`).
+
+4. Fixed a regression introduced by 2.0.2[5] that caused the TurboJPEG API to
+incorrectly identify some JPEG images with unusual sampling factors as 4:4:4
+JPEG images. This was known to cause a buffer overflow when attempting to
+decompress some such images using `tjDecompressToYUV2()` or
+`tjDecompressToYUVPlanes()`.
+
+5. Fixed an issue (CVE-2020-17541), detected by ASan, whereby attempting to
+losslessly transform a specially-crafted malformed JPEG image containing an
+extremely-high-frequency coefficient block (junk image data that could never be
+generated by a legitimate JPEG compressor) could cause the Huffman encoder's
+local buffer to be overrun. (Refer to 1.4.0[9] and 1.4beta1[15].) Given that
+the buffer overrun was fully contained within the stack and did not cause a
+segfault or other user-visible errant behavior, and given that the lossless
+transformer (unlike the decompressor) is not generally exposed to arbitrary
+data exploits, this issue did not likely pose a security risk.
+
+6. The Arm 64-bit (Armv8) Neon SIMD assembly code now stores constants in a
+separate read-only data section rather than in the text section, to support
+execute-only memory layouts.
+
+
+2.0.3
+=====
+
+### Significant changes relative to 2.0.2:
+
+1. Fixed "using JNI after critical get" errors that occurred on Android
+platforms when passing invalid arguments to certain methods in the TurboJPEG
+Java API.
+
+2. Fixed a regression in the SIMD feature detection code, introduced by
+the AVX2 SIMD extensions (2.0 beta1[1]), that was known to cause an illegal
+instruction exception, in rare cases, on CPUs that lack support for CPUID leaf
+07H (or on which the maximum CPUID leaf has been limited by way of a BIOS
+setting.)
+
+3. The 4:4:0 (h1v2) fancy (smooth) chroma upsampling algorithm in the
+decompressor now uses a similar bias pattern to that of the 4:2:2 (h2v1) fancy
+chroma upsampling algorithm, rounding up or down the upsampled result for
+alternate pixels rather than always rounding down. This ensures that,
+regardless of whether a 4:2:2 JPEG image is rotated or transposed prior to
+decompression (in the frequency domain) or after decompression (in the spatial
+domain), the final image will be similar.
+
+4. Fixed an integer overflow and subsequent segfault that occurred when
+attempting to compress or decompress images with more than 1 billion pixels
+using the TurboJPEG API.
+
+5. Fixed a regression introduced by 2.0 beta1[15] whereby attempting to
+generate a progressive JPEG image on an SSE2-capable CPU using a scan script
+containing one or more scans with lengths divisible by 16 would result in an
+error ("Missing Huffman code table entry") and an invalid JPEG image.
+
+6. Fixed an issue whereby `tjDecodeYUV()` and `tjDecodeYUVPlanes()` would throw
+an error ("Invalid progressive parameters") or a warning ("Inconsistent
+progression sequence") if passed a TurboJPEG instance that was previously used
+to decompress a progressive JPEG image.
+
+
+2.0.2
+=====
+
+### Significant changes relative to 2.0.1:
+
+1. Fixed a regression introduced by 2.0.1[5] that prevented a runtime search
+path (rpath) from being embedded in the libjpeg-turbo shared libraries and
+executables for macOS and iOS. This caused a fatal error of the form
+"dyld: Library not loaded" when attempting to use one of the executables,
+unless `DYLD_LIBRARY_PATH` was explicitly set to the location of the
+libjpeg-turbo shared libraries.
+
+2. Fixed an integer overflow and subsequent segfault (CVE-2018-20330) that
+occurred when attempting to load a BMP file with more than 1 billion pixels
+using the `tjLoadImage()` function.
+
+3. Fixed a buffer overrun (CVE-2018-19664) that occurred when attempting to
+decompress a specially-crafted malformed JPEG image to a 256-color BMP using
+djpeg.
+
+4. Fixed a floating point exception that occurred when attempting to
+decompress a specially-crafted malformed JPEG image with a specified image
+width or height of 0 using the C version of TJBench.
+
+5. The TurboJPEG API will now decompress 4:4:4 JPEG images with 2x1, 1x2, 3x1,
+or 1x3 luminance and chrominance sampling factors. This is a non-standard way
+of specifying 1x subsampling (normally 4:4:4 JPEGs have 1x1 luminance and
+chrominance sampling factors), but the JPEG format and the libjpeg API both
+allow it.
+
+6. Fixed a regression introduced by 2.0 beta1[7] that caused djpeg to generate
+incorrect PPM images when used with the `-colors` option.
+
+7. Fixed an issue whereby a static build of libjpeg-turbo (a build in which
+`ENABLE_SHARED` is `0`) could not be installed using the Visual Studio IDE.
+
+8. Fixed a severe performance issue in the Loongson MMI SIMD extensions that
+occurred when compressing RGB images whose image rows were not 64-bit-aligned.
+
+
+2.0.1
+=====
+
+### Significant changes relative to 2.0.0:
+
+1. Fixed a regression introduced with the new CMake-based Un*x build system,
+whereby jconfig.h could cause compiler warnings of the form
+`"HAVE_*_H" redefined` if it was included by downstream Autotools-based
+projects that used `AC_CHECK_HEADERS()` to check for the existence of locale.h,
+stddef.h, or stdlib.h.
+
+2. The `jsimd_quantize_float_dspr2()` and `jsimd_convsamp_float_dspr2()`
+functions in the MIPS DSPr2 SIMD extensions are now disabled at compile time
+if the soft float ABI is enabled. Those functions use instructions that are
+incompatible with the soft float ABI.
+
+3. Fixed a regression in the SIMD feature detection code, introduced by
+the AVX2 SIMD extensions (2.0 beta1[1]), that caused libjpeg-turbo to crash on
+Windows 7 if Service Pack 1 was not installed.
+
+4. Fixed out-of-bounds read in cjpeg that occurred when attempting to compress
+a specially-crafted malformed color-index (8-bit-per-sample) Targa file in
+which some of the samples (color indices) exceeded the bounds of the Targa
+file's color table.
+
+5. Fixed an issue whereby installing a fully static build of libjpeg-turbo
+(a build in which `CFLAGS` contains `-static` and `ENABLE_SHARED` is `0`) would
+fail with "No valid ELF RPATH or RUNPATH entry exists in the file."
+
+
+2.0.0
+=====
+
+### Significant changes relative to 2.0 beta1:
+
+1. The TurboJPEG API can now decompress CMYK JPEG images that have subsampled M
+and Y components (not to be confused with YCCK JPEG images, in which the C/M/Y
+components have been transformed into luma and chroma.) Previously, an error
+was generated ("Could not determine subsampling type for JPEG image") when such
+an image was passed to `tjDecompressHeader3()`, `tjTransform()`,
+`tjDecompressToYUVPlanes()`, `tjDecompressToYUV2()`, or the equivalent Java
+methods.
+
+2. Fixed an issue (CVE-2018-11813) whereby a specially-crafted malformed input
+file (specifically, a file with a valid Targa header but incomplete pixel data)
+would cause cjpeg to generate a JPEG file that was potentially thousands of
+times larger than the input file. The Targa reader in cjpeg was not properly
+detecting that the end of the input file had been reached prematurely, so after
+all valid pixels had been read from the input, the reader injected dummy pixels
+with values of 255 into the JPEG compressor until the number of pixels
+specified in the Targa header had been compressed. The Targa reader in cjpeg
+now behaves like the PPM reader and aborts compression if the end of the input
+file is reached prematurely. Because this issue only affected cjpeg and not
+the underlying library, and because it did not involve any out-of-bounds reads
+or other exploitable behaviors, it was not believed to represent a security
+threat.
+
+3. Fixed an issue whereby the `tjLoadImage()` and `tjSaveImage()` functions
+would produce a "Bogus message code" error message if the underlying bitmap and
+PPM readers/writers threw an error that was specific to the readers/writers
+(as opposed to a general libjpeg API error.)
+
+4. Fixed an issue (CVE-2018-1152) whereby a specially-crafted malformed BMP
+file, one in which the header specified an image width of 1073741824 pixels,
+would trigger a floating point exception (division by zero) in the
+`tjLoadImage()` function when attempting to load the BMP file into a
+4-component image buffer.
+
+5. Fixed an issue whereby certain combinations of calls to
+`jpeg_skip_scanlines()` and `jpeg_read_scanlines()` could trigger an infinite
+loop when decompressing progressive JPEG images that use vertical chroma
+subsampling (for instance, 4:2:0 or 4:4:0.)
+
+6. Fixed a segfault in `jpeg_skip_scanlines()` that occurred when decompressing
+a 4:2:2 or 4:2:0 JPEG image using the merged (non-fancy) upsampling algorithms
+(that is, when setting `cinfo.do_fancy_upsampling` to `FALSE`.)
+
+7. The new CMake-based build system will now disable the MIPS DSPr2 SIMD
+extensions if it detects that the compiler does not support DSPr2 instructions.
+
+8. Fixed out-of-bounds read in cjpeg (CVE-2018-14498) that occurred when
+attempting to compress a specially-crafted malformed color-index
+(8-bit-per-sample) BMP file in which some of the samples (color indices)
+exceeded the bounds of the BMP file's color table.
+
+9. Fixed a signed integer overflow in the progressive Huffman decoder, detected
+by the Clang and GCC undefined behavior sanitizers, that could be triggered by
+attempting to decompress a specially-crafted malformed JPEG image. This issue
+did not pose a security threat, but removing the warning made it easier to
+detect actual security issues, should they arise in the future.
+
+
+1.5.90 (2.0 beta1)
+==================
+
+### Significant changes relative to 1.5.3:
+
+1. Added AVX2 SIMD implementations of the colorspace conversion, chroma
+downsampling and upsampling, integer quantization and sample conversion, and
+accurate integer DCT/IDCT algorithms. When using the accurate integer DCT/IDCT
+algorithms on AVX2-equipped CPUs, the compression of RGB images is
+approximately 13-36% (avg. 22%) faster (relative to libjpeg-turbo 1.5.x) with
+64-bit code and 11-21% (avg. 17%) faster with 32-bit code, and the
+decompression of RGB images is approximately 9-35% (avg. 17%) faster with
+64-bit code and 7-17% (avg. 12%) faster with 32-bit code. (As tested on a
+3 GHz Intel Core i7. Actual mileage may vary.)
+
+2. Overhauled the build system to use CMake on all platforms, and removed the
+autotools-based build system. This decision resulted from extensive
+discussions within the libjpeg-turbo community. libjpeg-turbo traditionally
+used CMake only for Windows builds, but there was an increasing amount of
+demand to extend CMake support to other platforms. However, because of the
+unique nature of our code base (the need to support different assemblers on
+each platform, the need for Java support, etc.), providing dual build systems
+as other OSS imaging libraries do (including libpng and libtiff) would have
+created a maintenance burden. The use of CMake greatly simplifies some aspects
+of our build system, owing to CMake's built-in support for various assemblers,
+Java, and unit testing, as well as generally fewer quirks that have to be
+worked around in order to implement our packaging system. Eliminating
+autotools puts our project slightly at odds with the traditional practices of
+the OSS community, since most "system libraries" tend to be built with
+autotools, but it is believed that the benefits of this move outweigh the
+risks. In addition to providing a unified build environment, switching to
+CMake allows for the use of various build tools and IDEs that aren't supported
+under autotools, including XCode, Ninja, and Eclipse. It also eliminates the
+need to install autotools via MacPorts/Homebrew on OS X and allows
+libjpeg-turbo to be configured without the use of a terminal/command prompt.
+Extensive testing was conducted to ensure that all features provided by the
+autotools-based build system are provided by the new build system.
+
+3. The libjpeg API in this version of libjpeg-turbo now includes two additional
+functions, `jpeg_read_icc_profile()` and `jpeg_write_icc_profile()`, that can
+be used to extract ICC profile data from a JPEG file while decompressing or to
+embed ICC profile data in a JPEG file while compressing or transforming. This
+eliminates the need for downstream projects, such as color management libraries
+and browsers, to include their own glueware for accomplishing this.
+
+4. Improved error handling in the TurboJPEG API library:
+
+ - Introduced a new function (`tjGetErrorStr2()`) in the TurboJPEG C API
+that allows compression/decompression/transform error messages to be retrieved
+in a thread-safe manner. Retrieving error messages from global functions, such
+as `tjInitCompress()` or `tjBufSize()`, is still thread-unsafe, but since those
+functions will only throw errors if passed an invalid argument or if a memory
+allocation failure occurs, thread safety is not as much of a concern.
+ - Introduced a new function (`tjGetErrorCode()`) in the TurboJPEG C API
+and a new method (`TJException.getErrorCode()`) in the TurboJPEG Java API that
+can be used to determine the severity of the last
+compression/decompression/transform error. This allows applications to
+choose whether to ignore warnings (non-fatal errors) from the underlying
+libjpeg API or to treat them as fatal.
+ - Introduced a new flag (`TJFLAG_STOPONWARNING` in the TurboJPEG C API and
+`TJ.FLAG_STOPONWARNING` in the TurboJPEG Java API) that causes the library to
+immediately halt a compression/decompression/transform operation if it
+encounters a warning from the underlying libjpeg API (the default behavior is
+to allow the operation to complete unless a fatal error is encountered.)
+
+5. Introduced a new flag in the TurboJPEG C and Java APIs (`TJFLAG_PROGRESSIVE`
+and `TJ.FLAG_PROGRESSIVE`, respectively) that causes the library to use
+progressive entropy coding in JPEG images generated by compression and
+transform operations. Additionally, a new transform option
+(`TJXOPT_PROGRESSIVE` in the C API and `TJTransform.OPT_PROGRESSIVE` in the
+Java API) has been introduced, allowing progressive entropy coding to be
+enabled for selected transforms in a multi-transform operation.
+
+6. Introduced a new transform option in the TurboJPEG API (`TJXOPT_COPYNONE` in
+the C API and `TJTransform.OPT_COPYNONE` in the Java API) that allows the
+copying of markers (including EXIF and ICC profile data) to be disabled for a
+particular transform.
+
+7. Added two functions to the TurboJPEG C API (`tjLoadImage()` and
+`tjSaveImage()`) that can be used to load/save a BMP or PPM/PGM image to/from a
+memory buffer with a specified pixel format and layout. These functions
+replace the project-private (and slow) bmp API, which was previously used by
+TJBench, and they also provide a convenient way for first-time users of
+libjpeg-turbo to quickly develop a complete JPEG compression/decompression
+program.
+
+8. The TurboJPEG C API now includes a new convenience array (`tjAlphaOffset[]`)
+that contains the alpha component index for each pixel format (or -1 if the
+pixel format lacks an alpha component.) The TurboJPEG Java API now includes a
+new method (`TJ.getAlphaOffset()`) that returns the same value. In addition,
+the `tjRedOffset[]`, `tjGreenOffset[]`, and `tjBlueOffset[]` arrays-- and the
+corresponding `TJ.getRedOffset()`, `TJ.getGreenOffset()`, and
+`TJ.getBlueOffset()` methods-- now return -1 for `TJPF_GRAY`/`TJ.PF_GRAY`
+rather than 0. This allows programs to easily determine whether a pixel format
+has red, green, blue, and alpha components.
+
+9. Added a new example (tjexample.c) that demonstrates the basic usage of the
+TurboJPEG C API. This example mirrors the functionality of TJExample.java.
+Both files are now included in the libjpeg-turbo documentation.
+
+10. Fixed two signed integer overflows in the arithmetic decoder, detected by
+the Clang undefined behavior sanitizer, that could be triggered by attempting
+to decompress a specially-crafted malformed JPEG image. These issues did not
+pose a security threat, but removing the warnings makes it easier to detect
+actual security issues, should they arise in the future.
+
+11. Fixed a bug in the merged 4:2:0 upsampling/dithered RGB565 color conversion
+algorithm that caused incorrect dithering in the output image. This algorithm
+now produces bitwise-identical results to the unmerged algorithms.
+
+12. The SIMD function symbols for x86[-64]/ELF, MIPS/ELF, macOS/x86[-64] (if
+libjpeg-turbo is built with Yasm), and iOS/Arm[64] builds are now private.
+This prevents those symbols from being exposed in applications or shared
+libraries that link statically with libjpeg-turbo.
+
+13. Added Loongson MMI SIMD implementations of the RGB-to-YCbCr and
+YCbCr-to-RGB colorspace conversion, 4:2:0 chroma downsampling, 4:2:0 fancy
+chroma upsampling, integer quantization, and accurate integer DCT/IDCT
+algorithms. When using the accurate integer DCT/IDCT, this speeds up the
+compression of RGB images by approximately 70-100% and the decompression of RGB
+images by approximately 2-3.5x.
+
+14. Fixed a build error when building with older MinGW releases (regression
+caused by 1.5.1[7].)
+
+15. Added SIMD acceleration for progressive Huffman encoding on SSE2-capable
+x86 and x86-64 platforms. This speeds up the compression of full-color
+progressive JPEGs by about 85-90% on average (relative to libjpeg-turbo 1.5.x)
+when using modern Intel and AMD CPUs.
+
+
+1.5.3
+=====
+
+### Significant changes relative to 1.5.2:
+
+1. Fixed a NullPointerException in the TurboJPEG Java wrapper that occurred
+when using the YUVImage constructor that creates an instance backed by separate
+image planes and allocates memory for the image planes.
+
+2. Fixed an issue whereby the Java version of TJUnitTest would fail when
+testing BufferedImage encoding/decoding on big endian systems.
+
+3. Fixed a segfault in djpeg that would occur if an output format other than
+PPM/PGM was selected along with the `-crop` option. The `-crop` option now
+works with the GIF and Targa formats as well (unfortunately, it cannot be made
+to work with the BMP and RLE formats due to the fact that those output engines
+write scanlines in bottom-up order.) djpeg will now exit gracefully if an
+output format other than PPM/PGM, GIF, or Targa is selected along with the
+`-crop` option.
+
+4. Fixed an issue (CVE-2017-15232) whereby `jpeg_skip_scanlines()` would
+segfault if color quantization was enabled.
+
+5. TJBench (both C and Java versions) will now display usage information if any
+command-line argument is unrecognized. This prevents the program from silently
+ignoring typos.
+
+6. Fixed an access violation in tjbench.exe (Windows) that occurred when the
+program was used to decompress an existing JPEG image.
+
+7. Fixed an ArrayIndexOutOfBoundsException in the TJExample Java program that
+occurred when attempting to decompress a JPEG image that had been compressed
+with 4:1:1 chrominance subsampling.
+
+8. Fixed an issue whereby, when using `jpeg_skip_scanlines()` to skip to the
+end of a single-scan (non-progressive) image, subsequent calls to
+`jpeg_consume_input()` would return `JPEG_SUSPENDED` rather than
+`JPEG_REACHED_EOI`.
+
+9. `jpeg_crop_scanline()` now works correctly when decompressing grayscale JPEG
+images that were compressed with a sampling factor other than 1 (for instance,
+with `cjpeg -grayscale -sample 2x2`).
+
+
+1.5.2
+=====
+
+### Significant changes relative to 1.5.1:
+
+1. Fixed a regression introduced by 1.5.1[7] that prevented libjpeg-turbo from
+building with Android NDK platforms prior to android-21 (5.0).
+
+2. Fixed a regression introduced by 1.5.1[1] that prevented the MIPS DSPR2 SIMD
+code in libjpeg-turbo from building.
+
+3. Fixed a regression introduced by 1.5 beta1[11] that prevented the Java
+version of TJBench from outputting any reference images (the `-nowrite` switch
+was accidentally enabled by default.)
+
+4. libjpeg-turbo should now build and run with full AltiVec SIMD acceleration
+on PowerPC-based AmigaOS 4 and OpenBSD systems.
+
+5. Fixed build and runtime errors on Windows that occurred when building
+libjpeg-turbo with libjpeg v7 API/ABI emulation and the in-memory
+source/destination managers. Due to an oversight, the `jpeg_skip_scanlines()`
+and `jpeg_crop_scanline()` functions were not being included in jpeg7.dll when
+libjpeg-turbo was built with `-DWITH_JPEG7=1` and `-DWITH_MEMSRCDST=1`.
+
+6. Fixed "Bogus virtual array access" error that occurred when using the
+lossless crop feature in jpegtran or the TurboJPEG API, if libjpeg-turbo was
+built with libjpeg v7 API/ABI emulation. This was apparently a long-standing
+bug that has existed since the introduction of libjpeg v7/v8 API/ABI emulation
+in libjpeg-turbo v1.1.
+
+7. The lossless transform features in jpegtran and the TurboJPEG API will now
+always attempt to adjust the EXIF image width and height tags if the image size
+changed as a result of the transform. This behavior has always existed when
+using libjpeg v8 API/ABI emulation. It was supposed to be available with
+libjpeg v7 API/ABI emulation as well but did not work properly due to a bug.
+Furthermore, there was never any good reason not to enable it with libjpeg v6b
+API/ABI emulation, since the behavior is entirely internal. Note that
+`-copy all` must be passed to jpegtran in order to transfer the EXIF tags from
+the source image to the destination image.
+
+8. Fixed several memory leaks in the TurboJPEG API library that could occur
+if the library was built with certain compilers and optimization levels
+(known to occur with GCC 4.x and clang with `-O1` and higher but not with
+GCC 5.x or 6.x) and one of the underlying libjpeg API functions threw an error
+after a TurboJPEG API function allocated a local buffer.
+
+9. The libjpeg-turbo memory manager will now honor the `max_memory_to_use`
+structure member in jpeg\_memory\_mgr, which can be set to the maximum amount
+of memory (in bytes) that libjpeg-turbo should use during decompression or
+multi-pass (including progressive) compression. This limit can also be set
+using the `JPEGMEM` environment variable or using the `-maxmemory` switch in
+cjpeg/djpeg/jpegtran (refer to the respective man pages for more details.)
+This has been a documented feature of libjpeg since v5, but the
+`malloc()`/`free()` implementation of the memory manager (jmemnobs.c) never
+implemented the feature. Restricting libjpeg-turbo's memory usage is useful
+for two reasons: it allows testers to more easily work around the 2 GB limit
+in libFuzzer, and it allows developers of security-sensitive applications to
+more easily defend against one of the progressive JPEG exploits (LJT-01-004)
+identified in
+[this report](http://www.libjpeg-turbo.org/pmwiki/uploads/About/TwoIssueswiththeJPEGStandard.pdf).
+
+10. TJBench will now run each benchmark for 1 second prior to starting the
+timer, in order to improve the consistency of the results. Furthermore, the
+`-warmup` option is now used to specify the amount of warmup time rather than
+the number of warmup iterations.
+
+11. Fixed an error (`short jump is out of range`) that occurred when assembling
+the 32-bit x86 SIMD extensions with NASM versions prior to 2.04. This was a
+regression introduced by 1.5 beta1[12].
+
+
+1.5.1
+=====
+
+### Significant changes relative to 1.5.0:
+
+1. Previously, the undocumented `JSIMD_FORCE*` environment variables could be
+used to force-enable a particular SIMD instruction set if multiple instruction
+sets were available on a particular platform. On x86 platforms, where CPU
+feature detection is bulletproof and multiple SIMD instruction sets are
+available, it makes sense for those environment variables to allow forcing the
+use of an instruction set only if that instruction set is available. However,
+since the ARM implementations of libjpeg-turbo can only use one SIMD
+instruction set, and since their feature detection code is less bulletproof
+(parsing /proc/cpuinfo), it makes sense for the `JSIMD_FORCENEON` environment
+variable to bypass the feature detection code and really force the use of NEON
+instructions. A new environment variable (`JSIMD_FORCEDSPR2`) was introduced
+in the MIPS implementation for the same reasons, and the existing
+`JSIMD_FORCENONE` environment variable was extended to that implementation.
+These environment variables provide a workaround for those attempting to test
+ARM and MIPS builds of libjpeg-turbo in QEMU, which passes through
+/proc/cpuinfo from the host system.
+
+2. libjpeg-turbo previously assumed that AltiVec instructions were always
+available on PowerPC platforms, which led to "illegal instruction" errors when
+running on PowerPC chips that lack AltiVec support (such as the older 7xx/G3
+and newer e5500 series.) libjpeg-turbo now examines /proc/cpuinfo on
+Linux/Android systems and enables AltiVec instructions only if the CPU supports
+them. It also now provides two environment variables, `JSIMD_FORCEALTIVEC` and
+`JSIMD_FORCENONE`, to force-enable and force-disable AltiVec instructions in
+environments where /proc/cpuinfo is an unreliable means of CPU feature
+detection (such as when running in QEMU.) On OS X, libjpeg-turbo continues to
+assume that AltiVec support is always available, which means that libjpeg-turbo
+cannot be used with G3 Macs unless you set the environment variable
+`JSIMD_FORCENONE` to `1`.
+
+3. Fixed an issue whereby 64-bit ARM (AArch64) builds of libjpeg-turbo would
+crash when built with recent releases of the Clang/LLVM compiler. This was
+caused by an ABI conformance issue in some of libjpeg-turbo's 64-bit NEON SIMD
+routines. Those routines were incorrectly using 64-bit instructions to
+transfer a 32-bit JDIMENSION argument, whereas the ABI allows the upper
+(unused) 32 bits of a 32-bit argument's register to be undefined. The new
+Clang/LLVM optimizer uses load combining to transfer multiple adjacent 32-bit
+structure members into a single 64-bit register, and this exposed the ABI
+conformance issue.
+
+4. Fancy upsampling is now supported when decompressing JPEG images that use
+4:4:0 (h1v2) chroma subsampling. These images are generated when losslessly
+rotating or transposing JPEG images that use 4:2:2 (h2v1) chroma subsampling.
+The h1v2 fancy upsampling algorithm is not currently SIMD-accelerated.
+
+5. If merged upsampling isn't SIMD-accelerated but YCbCr-to-RGB conversion is,
+then libjpeg-turbo will now disable merged upsampling when decompressing YCbCr
+JPEG images into RGB or extended RGB output images. This significantly speeds
+up the decompression of 4:2:0 and 4:2:2 JPEGs on ARM platforms if fancy
+upsampling is not used (for example, if the `-nosmooth` option to djpeg is
+specified.)
+
+6. The TurboJPEG API will now decompress 4:2:2 and 4:4:0 JPEG images with
+2x2 luminance sampling factors and 2x1 or 1x2 chrominance sampling factors.
+This is a non-standard way of specifying 2x subsampling (normally 4:2:2 JPEGs
+have 2x1 luminance and 1x1 chrominance sampling factors, and 4:4:0 JPEGs have
+1x2 luminance and 1x1 chrominance sampling factors), but the JPEG format and
+the libjpeg API both allow it.
+
+7. Fixed an unsigned integer overflow in the libjpeg memory manager, detected
+by the Clang undefined behavior sanitizer, that could be triggered by
+attempting to decompress a specially-crafted malformed JPEG image. This issue
+affected only 32-bit code and did not pose a security threat, but removing the
+warning makes it easier to detect actual security issues, should they arise in
+the future.
+
+8. Fixed additional negative left shifts and other issues reported by the GCC
+and Clang undefined behavior sanitizers when attempting to decompress
+specially-crafted malformed JPEG images. None of these issues posed a security
+threat, but removing the warnings makes it easier to detect actual security
+issues, should they arise in the future.
+
+9. Fixed an out-of-bounds array reference, introduced by 1.4.90[2] (partial
+image decompression) and detected by the Clang undefined behavior sanitizer,
+that could be triggered by a specially-crafted malformed JPEG image with more
+than four components. Because the out-of-bounds reference was still within the
+same structure, it was not known to pose a security threat, but removing the
+warning makes it easier to detect actual security issues, should they arise in
+the future.
+
+10. Fixed another ABI conformance issue in the 64-bit ARM (AArch64) NEON SIMD
+code. Some of the routines were incorrectly reading and storing data below the
+stack pointer, which caused segfaults in certain applications under specific
+circumstances.
+
+
+1.5.0
+=====
+
+### Significant changes relative to 1.5 beta1:
+
+1. Fixed an issue whereby a malformed motion-JPEG frame could cause the "fast
+path" of libjpeg-turbo's Huffman decoder to read from uninitialized memory.
+
+2. Added libjpeg-turbo version and build information to the global string table
+of the libjpeg and TurboJPEG API libraries. This is a common practice in other
+infrastructure libraries, such as OpenSSL and libpng, because it makes it easy
+to examine an application binary and determine which version of the library the
+application was linked against.
+
+3. Fixed a couple of issues in the PPM reader that would cause buffer overruns
+in cjpeg if one of the values in a binary PPM/PGM input file exceeded the
+maximum value defined in the file's header and that maximum value was greater
+than 255. libjpeg-turbo 1.4.2 already included a similar fix for ASCII PPM/PGM
+files. Note that these issues were not security bugs, since they were confined
+to the cjpeg program and did not affect any of the libjpeg-turbo libraries.
+
+4. Fixed an issue whereby attempting to decompress a JPEG file with a corrupt
+header using the `tjDecompressToYUV2()` function would cause the function to
+abort without returning an error and, under certain circumstances, corrupt the
+stack. This only occurred if `tjDecompressToYUV2()` was called prior to
+calling `tjDecompressHeader3()`, or if the return value from
+`tjDecompressHeader3()` was ignored (both cases represent incorrect usage of
+the TurboJPEG API.)
+
+5. Fixed an issue in the ARM 32-bit SIMD-accelerated Huffman encoder that
+prevented the code from assembling properly with clang.
+
+6. The `jpeg_stdio_src()`, `jpeg_mem_src()`, `jpeg_stdio_dest()`, and
+`jpeg_mem_dest()` functions in the libjpeg API will now throw an error if a
+source/destination manager has already been assigned to the compress or
+decompress object by a different function or by the calling program. This
+prevents these functions from attempting to reuse a source/destination manager
+structure that was allocated elsewhere, because there is no way to ensure that
+it would be big enough to accommodate the new source/destination manager.
+
+
+1.4.90 (1.5 beta1)
+==================
+
+### Significant changes relative to 1.4.2:
+
+1. Added full SIMD acceleration for PowerPC platforms using AltiVec VMX
+(128-bit SIMD) instructions. Although the performance of libjpeg-turbo on
+PowerPC was already good, due to the increased number of registers available
+to the compiler vs. x86, it was still possible to speed up compression by about
+3-4x and decompression by about 2-2.5x (relative to libjpeg v6b) through the
+use of AltiVec instructions.
+
+2. Added two new libjpeg API functions (`jpeg_skip_scanlines()` and
+`jpeg_crop_scanline()`) that can be used to partially decode a JPEG image. See
+[libjpeg.txt](libjpeg.txt) for more details.
+
+3. The TJCompressor and TJDecompressor classes in the TurboJPEG Java API now
+implement the Closeable interface, so those classes can be used with a
+try-with-resources statement.
+
+4. The TurboJPEG Java classes now throw unchecked idiomatic exceptions
+(IllegalArgumentException, IllegalStateException) for unrecoverable errors
+caused by incorrect API usage, and those classes throw a new checked exception
+type (TJException) for errors that are passed through from the C library.
+
+5. Source buffers for the TurboJPEG C API functions, as well as the
+`jpeg_mem_src()` function in the libjpeg API, are now declared as const
+pointers. This facilitates passing read-only buffers to those functions and
+ensures the caller that the source buffer will not be modified. This should
+not create any backward API or ABI incompatibilities with prior libjpeg-turbo
+releases.
+
+6. The MIPS DSPr2 SIMD code can now be compiled to support either FR=0 or FR=1
+FPUs.
+
+7. Fixed additional negative left shifts and other issues reported by the GCC
+and Clang undefined behavior sanitizers. Most of these issues affected only
+32-bit code, and none of them was known to pose a security threat, but removing
+the warnings makes it easier to detect actual security issues, should they
+arise in the future.
+
+8. Removed the unnecessary `.arch` directive from the ARM64 NEON SIMD code.
+This directive was preventing the code from assembling using the clang
+integrated assembler.
+
+9. Fixed a regression caused by 1.4.1[6] that prevented 32-bit and 64-bit
+libjpeg-turbo RPMs from being installed simultaneously on recent Red Hat/Fedora
+distributions. This was due to the addition of a macro in jconfig.h that
+allows the Huffman codec to determine the word size at compile time. Since
+that macro differs between 32-bit and 64-bit builds, this caused a conflict
+between the i386 and x86_64 RPMs (any differing files, other than executables,
+are not allowed when 32-bit and 64-bit RPMs are installed simultaneously.)
+Since the macro is used only internally, it has been moved into jconfigint.h.
+
+10. The x86-64 SIMD code can now be disabled at run time by setting the
+`JSIMD_FORCENONE` environment variable to `1` (the other SIMD implementations
+already had this capability.)
+
+11. Added a new command-line argument to TJBench (`-nowrite`) that prevents the
+benchmark from outputting any images. This removes any potential operating
+system overhead that might be caused by lazy writes to disk and thus improves
+the consistency of the performance measurements.
+
+12. Added SIMD acceleration for Huffman encoding on SSE2-capable x86 and x86-64
+platforms. This speeds up the compression of full-color JPEGs by about 10-15%
+on average (relative to libjpeg-turbo 1.4.x) when using modern Intel and AMD
+CPUs. Additionally, this works around an issue in the clang optimizer that
+prevents it (as of this writing) from achieving the same performance as GCC
+when compiling the C version of the Huffman encoder
+(<https://llvm.org/bugs/show_bug.cgi?id=16035>). For the purposes of
+benchmarking or regression testing, SIMD-accelerated Huffman encoding can be
+disabled by setting the `JSIMD_NOHUFFENC` environment variable to `1`.
+
+13. Added ARM 64-bit (ARMv8) NEON SIMD implementations of the commonly-used
+compression algorithms (including the accurate integer forward DCT and h2v2 &
+h2v1 downsampling algorithms, which are not accelerated in the 32-bit NEON
+implementation.) This speeds up the compression of full-color JPEGs by about
+75% on average on a Cavium ThunderX processor and by about 2-2.5x on average on
+Cortex-A53 and Cortex-A57 cores.
+
+14. Added SIMD acceleration for Huffman encoding on NEON-capable ARM 32-bit
+and 64-bit platforms.
+
+ For 32-bit code, this speeds up the compression of full-color JPEGs by
+about 30% on average on a typical iOS device (iPhone 4S, Cortex-A9) and by
+about 6-7% on average on a typical Android device (Nexus 5X, Cortex-A53 and
+Cortex-A57), relative to libjpeg-turbo 1.4.x. Note that the larger speedup
+under iOS is due to the fact that iOS builds use LLVM, which does not optimize
+the C Huffman encoder as well as GCC does.
+
+ For 64-bit code, NEON-accelerated Huffman encoding speeds up the
+compression of full-color JPEGs by about 40% on average on a typical iOS device
+(iPhone 5S, Apple A7) and by about 7-8% on average on a typical Android device
+(Nexus 5X, Cortex-A53 and Cortex-A57), in addition to the speedup described in
+[13] above.
+
+ For the purposes of benchmarking or regression testing, SIMD-accelerated
+Huffman encoding can be disabled by setting the `JSIMD_NOHUFFENC` environment
+variable to `1`.
+
+15. pkg-config (.pc) scripts are now included for both the libjpeg and
+TurboJPEG API libraries on Un*x systems. Note that if a project's build system
+relies on these scripts, then it will not be possible to build that project
+with libjpeg or with a prior version of libjpeg-turbo.
+
+16. Optimized the ARM 64-bit (ARMv8) NEON SIMD decompression routines to
+improve performance on CPUs with in-order pipelines. This speeds up the
+decompression of full-color JPEGs by nearly 2x on average on a Cavium ThunderX
+processor and by about 15% on average on a Cortex-A53 core.
+
+17. Fixed an issue in the accelerated Huffman decoder that could have caused
+the decoder to read past the end of the input buffer when a malformed,
+specially-crafted JPEG image was being decompressed. In prior versions of
+libjpeg-turbo, the accelerated Huffman decoder was invoked (in most cases) only
+if there were > 128 bytes of data in the input buffer. However, it is possible
+to construct a JPEG image in which a single Huffman block is over 430 bytes
+long, so this version of libjpeg-turbo activates the accelerated Huffman
+decoder only if there are > 512 bytes of data in the input buffer.
+
+18. Fixed a memory leak in tjunittest encountered when running the program
+with the `-yuv` option.
+
+
+1.4.2
+=====
+
+### Significant changes relative to 1.4.1:
+
+1. Fixed an issue whereby cjpeg would segfault if a Windows bitmap with a
+negative width or height was used as an input image (Windows bitmaps can have
+a negative height if they are stored in top-down order, but such files are
+rare and not supported by libjpeg-turbo.)
+
+2. Fixed an issue whereby, under certain circumstances, libjpeg-turbo would
+incorrectly encode certain JPEG images when quality=100 and the fast integer
+forward DCT were used. This was known to cause `make test` to fail when the
+library was built with `-march=haswell` on x86 systems.
+
+3. Fixed an issue whereby libjpeg-turbo would crash when built with the latest
+& greatest development version of the Clang/LLVM compiler. This was caused by
+an x86-64 ABI conformance issue in some of libjpeg-turbo's 64-bit SSE2 SIMD
+routines. Those routines were incorrectly using a 64-bit `mov` instruction to
+transfer a 32-bit JDIMENSION argument, whereas the x86-64 ABI allows the upper
+(unused) 32 bits of a 32-bit argument's register to be undefined. The new
+Clang/LLVM optimizer uses load combining to transfer multiple adjacent 32-bit
+structure members into a single 64-bit register, and this exposed the ABI
+conformance issue.
+
+4. Fixed a bug in the MIPS DSPr2 4:2:0 "plain" (non-fancy and non-merged)
+upsampling routine that caused a buffer overflow (and subsequent segfault) when
+decompressing a 4:2:0 JPEG image whose scaled output width was less than 16
+pixels. The "plain" upsampling routines are normally only used when
+decompressing a non-YCbCr JPEG image, but they are also used when decompressing
+a JPEG image whose scaled output height is 1.
+
+5. Fixed various negative left shifts and other issues reported by the GCC and
+Clang undefined behavior sanitizers. None of these was known to pose a
+security threat, but removing the warnings makes it easier to detect actual
+security issues, should they arise in the future.
+
+
+1.4.1
+=====
+
+### Significant changes relative to 1.4.0:
+
+1. tjbench now properly handles CMYK/YCCK JPEG files. Passing an argument of
+`-cmyk` (instead of, for instance, `-rgb`) will cause tjbench to internally
+convert the source bitmap to CMYK prior to compression, to generate YCCK JPEG
+files, and to internally convert the decompressed CMYK pixels back to RGB after
+decompression (the latter is done automatically if a CMYK or YCCK JPEG is
+passed to tjbench as a source image.) The CMYK<->RGB conversion operation is
+not benchmarked. NOTE: The quick & dirty CMYK<->RGB conversions that tjbench
+uses are suitable for testing only. Proper conversion between CMYK and RGB
+requires a color management system.
+
+2. `make test` now performs additional bitwise regression tests using tjbench,
+mainly for the purpose of testing compression from/decompression to a subregion
+of a larger image buffer.
+
+3. `make test` no longer tests the regression of the floating point DCT/IDCT
+by default, since the results of those tests can vary if the algorithms in
+question are not implemented using SIMD instructions on a particular platform.
+See the comments in [Makefile.am](Makefile.am) for information on how to
+re-enable the tests and to specify an expected result for them based on the
+particulars of your platform.
+
+4. The NULL color conversion routines have been significantly optimized,
+which speeds up the compression of RGB and CMYK JPEGs by 5-20% when using
+64-bit code and 0-3% when using 32-bit code, and the decompression of those
+images by 10-30% when using 64-bit code and 3-12% when using 32-bit code.
+
+5. Fixed an "illegal instruction" error that occurred when djpeg from a
+SIMD-enabled libjpeg-turbo MIPS build was executed with the `-nosmooth` option
+on a MIPS machine that lacked DSPr2 support. The MIPS SIMD routines for h2v1
+and h2v2 merged upsampling were not properly checking for the existence of
+DSPr2.
+
+6. Performance has been improved significantly on 64-bit non-Linux and
+non-Windows platforms (generally 10-20% faster compression and 5-10% faster
+decompression.) Due to an oversight, the 64-bit version of the accelerated
+Huffman codec was not being compiled in when libjpeg-turbo was built on
+platforms other than Windows or Linux. Oops.
+
+7. Fixed an extremely rare bug in the Huffman encoder that caused 64-bit
+builds of libjpeg-turbo to incorrectly encode a few specific test images when
+quality=98, an optimized Huffman table, and the accurate integer forward DCT
+were used.
+
+8. The Windows (CMake) build system now supports building only static or only
+shared libraries. This is accomplished by adding either `-DENABLE_STATIC=0` or
+`-DENABLE_SHARED=0` to the CMake command line.
+
+9. TurboJPEG API functions will now return an error code if a warning is
+triggered in the underlying libjpeg API. For instance, if a JPEG file is
+corrupt, the TurboJPEG decompression functions will attempt to decompress
+as much of the image as possible, but those functions will now return -1 to
+indicate that the decompression was not entirely successful.
+
+10. Fixed a bug in the MIPS DSPr2 4:2:2 fancy upsampling routine that caused a
+buffer overflow (and subsequent segfault) when decompressing a 4:2:2 JPEG image
+in which the right-most MCU was 5 or 6 pixels wide.
+
+
+1.4.0
+=====
+
+### Significant changes relative to 1.4 beta1:
+
+1. Fixed a build issue on OS X PowerPC platforms (md5cmp failed to build
+because OS X does not provide the `le32toh()` and `htole32()` functions.)
+
+2. The non-SIMD RGB565 color conversion code did not work correctly on big
+endian machines. This has been fixed.
+
+3. Fixed an issue in `tjPlaneSizeYUV()` whereby it would erroneously return 1
+instead of -1 if `componentID` was > 0 and `subsamp` was `TJSAMP_GRAY`.
+
+3. Fixed an issue in `tjBufSizeYUV2()` whereby it would erroneously return 0
+instead of -1 if `width` was < 1.
+
+5. The Huffman encoder now uses `clz` and `bsr` instructions for bit counting
+on ARM64 platforms (see 1.4 beta1[5].)
+
+6. The `close()` method in the TJCompressor and TJDecompressor Java classes is
+now idempotent. Previously, that method would call the native `tjDestroy()`
+function even if the TurboJPEG instance had already been destroyed. This
+caused an exception to be thrown during finalization, if the `close()` method
+had already been called. The exception was caught, but it was still an
+expensive operation.
+
+7. The TurboJPEG API previously generated an error (`Could not determine
+subsampling type for JPEG image`) when attempting to decompress grayscale JPEG
+images that were compressed with a sampling factor other than 1 (for instance,
+with `cjpeg -grayscale -sample 2x2`). Subsampling technically has no meaning
+with grayscale JPEGs, and thus the horizontal and vertical sampling factors
+for such images are ignored by the decompressor. However, the TurboJPEG API
+was being too rigid and was expecting the sampling factors to be equal to 1
+before it treated the image as a grayscale JPEG.
+
+8. cjpeg, djpeg, and jpegtran now accept an argument of `-version`, which will
+print the library version and exit.
+
+9. Referring to 1.4 beta1[15], another extremely rare circumstance was
+discovered under which the Huffman encoder's local buffer can be overrun
+when a buffered destination manager is being used and an
+extremely-high-frequency block (basically junk image data) is being encoded.
+Even though the Huffman local buffer was increased from 128 bytes to 136 bytes
+to address the previous issue, the new issue caused even the larger buffer to
+be overrun. Further analysis reveals that, in the absolute worst case (such as
+setting alternating AC coefficients to 32767 and -32768 in the JPEG scanning
+order), the Huffman encoder can produce encoded blocks that approach double the
+size of the unencoded blocks. Thus, the Huffman local buffer was increased to
+256 bytes, which should prevent any such issue from re-occurring in the future.
+
+10. The new `tjPlaneSizeYUV()`, `tjPlaneWidth()`, and `tjPlaneHeight()`
+functions were not actually usable on any platform except OS X and Windows,
+because those functions were not included in the libturbojpeg mapfile. This
+has been fixed.
+
+11. Restored the `JPP()`, `JMETHOD()`, and `FAR` macros in the libjpeg-turbo
+header files. The `JPP()` and `JMETHOD()` macros were originally implemented
+in libjpeg as a way of supporting non-ANSI compilers that lacked support for
+prototype parameters. libjpeg-turbo has never supported such compilers, but
+some software packages still use the macros to define their own prototypes.
+Similarly, libjpeg-turbo has never supported MS-DOS and other platforms that
+have far symbols, but some software packages still use the `FAR` macro. A
+pretty good argument can be made that this is a bad practice on the part of the
+software in question, but since this affects more than one package, it's just
+easier to fix it here.
+
+12. Fixed issues that were preventing the ARM 64-bit SIMD code from compiling
+for iOS, and included an ARMv8 architecture in all of the binaries installed by
+the "official" libjpeg-turbo SDK for OS X.
+
+
+1.3.90 (1.4 beta1)
+==================
+
+### Significant changes relative to 1.3.1:
+
+1. New features in the TurboJPEG API:
+
+ - YUV planar images can now be generated with an arbitrary line padding
+(previously only 4-byte padding, which was compatible with X Video, was
+supported.)
+ - The decompress-to-YUV function has been extended to support image
+scaling.
+ - JPEG images can now be compressed from YUV planar source images.
+ - YUV planar images can now be decoded into RGB or grayscale images.
+ - 4:1:1 subsampling is now supported. This is mainly included for
+compatibility, since 4:1:1 is not fully accelerated in libjpeg-turbo and has no
+significant advantages relative to 4:2:0.
+ - CMYK images are now supported. This feature allows CMYK source images
+to be compressed to YCCK JPEGs and YCCK or CMYK JPEGs to be decompressed to
+CMYK destination images. Conversion between CMYK/YCCK and RGB or YUV images is
+not supported. Such conversion requires a color management system and is thus
+out of scope for a codec library.
+ - The handling of YUV images in the Java API has been significantly
+refactored and should now be much more intuitive.
+ - The Java API now supports encoding a YUV image from an arbitrary
+position in a large image buffer.
+ - All of the YUV functions now have a corresponding function that operates
+on separate image planes instead of a unified image buffer. This allows for
+compressing/decoding from or decompressing/encoding to a subregion of a larger
+YUV image. It also allows for handling YUV formats that swap the order of the
+U and V planes.
+
+2. Added SIMD acceleration for DSPr2-capable MIPS platforms. This speeds up
+the compression of full-color JPEGs by 70-80% on such platforms and
+decompression by 25-35%.
+
+3. If an application attempts to decompress a Huffman-coded JPEG image whose
+header does not contain Huffman tables, libjpeg-turbo will now insert the
+default Huffman tables. In order to save space, many motion JPEG video frames
+are encoded without the default Huffman tables, so these frames can now be
+successfully decompressed by libjpeg-turbo without additional work on the part
+of the application. An application can still override the Huffman tables, for
+instance to re-use tables from a previous frame of the same video.
+
+4. The Mac packaging system now uses pkgbuild and productbuild rather than
+PackageMaker (which is obsolete and no longer supported.) This means that
+OS X 10.6 "Snow Leopard" or later must be used when packaging libjpeg-turbo,
+although the packages produced can be installed on OS X 10.5 "Leopard" or
+later. OS X 10.4 "Tiger" is no longer supported.
+
+5. The Huffman encoder now uses `clz` and `bsr` instructions for bit counting
+on ARM platforms rather than a lookup table. This reduces the memory footprint
+by 64k, which may be important for some mobile applications. Out of four
+Android devices that were tested, two demonstrated a small overall performance
+loss (~3-4% on average) with ARMv6 code and a small gain (also ~3-4%) with
+ARMv7 code when enabling this new feature, but the other two devices
+demonstrated a significant overall performance gain with both ARMv6 and ARMv7
+code (~10-20%) when enabling the feature. Actual mileage may vary.
+
+6. Worked around an issue with Visual C++ 2010 and later that caused incorrect
+pixels to be generated when decompressing a JPEG image to a 256-color bitmap,
+if compiler optimization was enabled when libjpeg-turbo was built. This caused
+the regression tests to fail when doing a release build under Visual C++ 2010
+and later.
+
+7. Improved the accuracy and performance of the non-SIMD implementation of the
+floating point inverse DCT (using code borrowed from libjpeg v8a and later.)
+The accuracy of this implementation now matches the accuracy of the SSE/SSE2
+implementation. Note, however, that the floating point DCT/IDCT algorithms are
+mainly a legacy feature. They generally do not produce significantly better
+accuracy than the accurate integer DCT/IDCT algorithms, and they are quite a
+bit slower.
+
+8. Added a new output colorspace (`JCS_RGB565`) to the libjpeg API that allows
+for decompressing JPEG images into RGB565 (16-bit) pixels. If dithering is not
+used, then this code path is SIMD-accelerated on ARM platforms.
+
+9. Numerous obsolete features, such as support for non-ANSI compilers and
+support for the MS-DOS memory model, were removed from the libjpeg code,
+greatly improving its readability and making it easier to maintain and extend.
+
+10. Fixed a segfault that occurred when calling `output_message()` with
+`msg_code` set to `JMSG_COPYRIGHT`.
+
+11. Fixed an issue whereby wrjpgcom was allowing comments longer than 65k
+characters to be passed on the command line, which was causing it to generate
+incorrect JPEG files.
+
+12. Fixed a bug in the build system that was causing the Windows version of
+wrjpgcom to be built using the rdjpgcom source code.
+
+13. Restored 12-bit-per-component JPEG support. A 12-bit version of
+libjpeg-turbo can now be built by passing an argument of `--with-12bit` to
+configure (Unix) or `-DWITH_12BIT=1` to cmake (Windows.) 12-bit JPEG support
+is included only for convenience. Enabling this feature disables all of the
+performance features in libjpeg-turbo, as well as arithmetic coding and the
+TurboJPEG API. The resulting library still contains the other libjpeg-turbo
+features (such as the colorspace extensions), but in general, it performs no
+faster than libjpeg v6b.
+
+14. Added ARM 64-bit SIMD acceleration for the YCC-to-RGB color conversion
+and IDCT algorithms (both are used during JPEG decompression.) For unknown
+reasons (probably related to clang), this code cannot currently be compiled for
+iOS.
+
+15. Fixed an extremely rare bug (CVE-2014-9092) that could cause the Huffman
+encoder's local buffer to overrun when a very high-frequency MCU is compressed
+using quality 100 and no subsampling, and when the JPEG output buffer is being
+dynamically resized by the destination manager. This issue was so rare that,
+even with a test program specifically designed to make the bug occur (by
+injecting random high-frequency YUV data into the compressor), it was
+reproducible only once in about every 25 million iterations.
+
+16. Fixed an oversight in the TurboJPEG C wrapper: if any of the JPEG
+compression functions was called repeatedly with the same
+automatically-allocated destination buffer, then TurboJPEG would erroneously
+assume that the `jpegSize` parameter was equal to the size of the buffer, when
+in fact that parameter was probably equal to the size of the most recently
+compressed JPEG image. If the size of the previous JPEG image was not as large
+as the current JPEG image, then TurboJPEG would unnecessarily reallocate the
+destination buffer.
+
+
+1.3.1
+=====
+
+### Significant changes relative to 1.3.0:
+
+1. On Un*x systems, `make install` now installs the libjpeg-turbo libraries
+into /opt/libjpeg-turbo/lib32 by default on any 32-bit system, not just x86,
+and into /opt/libjpeg-turbo/lib64 by default on any 64-bit system, not just
+x86-64. You can override this by overriding either the `prefix` or `libdir`
+configure variables.
+
+2. The Windows installer now places a copy of the TurboJPEG DLLs in the same
+directory as the rest of the libjpeg-turbo binaries. This was mainly done
+to support TurboVNC 1.3, which bundles the DLLs in its Windows installation.
+When using a 32-bit version of CMake on 64-bit Windows, it is impossible to
+access the c:\WINDOWS\system32 directory, which made it impossible for the
+TurboVNC build scripts to bundle the 64-bit TurboJPEG DLL.
+
+3. Fixed a bug whereby attempting to encode a progressive JPEG with arithmetic
+entropy coding (by passing arguments of `-progressive -arithmetic` to cjpeg or
+jpegtran, for instance) would result in an error, `Requested feature was
+omitted at compile time`.
+
+4. Fixed a couple of issues (CVE-2013-6629 and CVE-2013-6630) whereby malformed
+JPEG images would cause libjpeg-turbo to use uninitialized memory during
+decompression.
+
+5. Fixed an error (`Buffer passed to JPEG library is too small`) that occurred
+when calling the TurboJPEG YUV encoding function with a very small (< 5x5)
+source image, and added a unit test to check for this error.
+
+6. The Java classes should now build properly under Visual Studio 2010 and
+later.
+
+7. Fixed an issue that prevented SRPMs generated using the in-tree packaging
+tools from being rebuilt on certain newer Linux distributions.
+
+8. Numerous minor fixes to eliminate compilation and build/packaging system
+warnings, fix cosmetic issues, improve documentation clarity, and other general
+source cleanup.
+
+
+1.3.0
+=====
+
+### Significant changes relative to 1.3 beta1:
+
+1. `make test` now works properly on FreeBSD, and it no longer requires the
+md5sum executable to be present on other Un*x platforms.
+
+2. Overhauled the packaging system:
+
+ - To avoid conflict with vendor-supplied libjpeg-turbo packages, the
+official RPMs and DEBs for libjpeg-turbo have been renamed to
+"libjpeg-turbo-official".
+ - The TurboJPEG libraries are now located under /opt/libjpeg-turbo in the
+official Linux and Mac packages, to avoid conflict with vendor-supplied
+packages and also to streamline the packaging system.
+ - Release packages are now created with the directory structure defined
+by the configure variables `prefix`, `bindir`, `libdir`, etc. (Un\*x) or by the
+`CMAKE_INSTALL_PREFIX` variable (Windows.) The exception is that the docs are
+always located under the system default documentation directory on Un\*x and
+Mac systems, and on Windows, the TurboJPEG DLL is always located in the Windows
+system directory.
+ - To avoid confusion, official libjpeg-turbo packages on Linux/Unix
+platforms (except for Mac) will always install the 32-bit libraries in
+/opt/libjpeg-turbo/lib32 and the 64-bit libraries in /opt/libjpeg-turbo/lib64.
+ - Fixed an issue whereby, in some cases, the libjpeg-turbo executables on
+Un*x systems were not properly linking with the shared libraries installed by
+the same package.
+ - Fixed an issue whereby building the "installer" target on Windows when
+`WITH_JAVA=1` would fail if the TurboJPEG JAR had not been previously built.
+ - Building the "install" target on Windows now installs files into the
+same places that the installer does.
+
+3. Fixed a Huffman encoder bug that prevented I/O suspension from working
+properly.
+
+
+1.2.90 (1.3 beta1)
+==================
+
+### Significant changes relative to 1.2.1:
+
+1. Added support for additional scaling factors (3/8, 5/8, 3/4, 7/8, 9/8, 5/4,
+11/8, 3/2, 13/8, 7/4, 15/8, and 2) when decompressing. Note that the IDCT will
+not be SIMD-accelerated when using any of these new scaling factors.
+
+2. The TurboJPEG dynamic library is now versioned. It was not strictly
+necessary to do so, because TurboJPEG uses versioned symbols, and if a function
+changes in an ABI-incompatible way, that function is renamed and a legacy
+function is provided to maintain backward compatibility. However, certain
+Linux distro maintainers have a policy against accepting any library that isn't
+versioned.
+
+3. Extended the TurboJPEG Java API so that it can be used to compress a JPEG
+image from and decompress a JPEG image to an arbitrary position in a large
+image buffer.
+
+4. The `tjDecompressToYUV()` function now supports the `TJFLAG_FASTDCT` flag.
+
+5. The 32-bit supplementary package for amd64 Debian systems now provides
+symlinks in /usr/lib/i386-linux-gnu for the TurboJPEG libraries in /usr/lib32.
+This allows those libraries to be used on MultiArch-compatible systems (such as
+Ubuntu 11 and later) without setting the linker path.
+
+6. The TurboJPEG Java wrapper should now find the JNI library on Mac systems
+without having to pass `-Djava.library.path=/usr/lib` to java.
+
+7. TJBench has been ported to Java to provide a convenient way of validating
+the performance of the TurboJPEG Java API. It can be run with
+`java -cp turbojpeg.jar TJBench`.
+
+8. cjpeg can now be used to generate JPEG files with the RGB colorspace
+(feature ported from jpeg-8d.)
+
+9. The width and height in the `-crop` argument passed to jpegtran can now be
+suffixed with `f` to indicate that, when the upper left corner of the cropping
+region is automatically moved to the nearest iMCU boundary, the bottom right
+corner should be moved by the same amount. In other words, this feature causes
+jpegtran to strictly honor the specified width/height rather than the specified
+bottom right corner (feature ported from jpeg-8d.)
+
+10. JPEG files using the RGB colorspace can now be decompressed into grayscale
+images (feature ported from jpeg-8d.)
+
+11. Fixed a regression caused by 1.2.1[7] whereby the build would fail with
+multiple "Mismatch in operand sizes" errors when attempting to build the x86
+SIMD code with NASM 0.98.
+
+12. The in-memory source/destination managers (`jpeg_mem_src()` and
+`jpeg_mem_dest()`) are now included by default when building libjpeg-turbo with
+libjpeg v6b or v7 emulation, so that programs can take advantage of these
+functions without requiring the use of the backward-incompatible libjpeg v8
+ABI. The "age number" of the libjpeg-turbo library on Un*x systems has been
+incremented by 1 to reflect this. You can disable this feature with a
+configure/CMake switch in order to retain strict API/ABI compatibility with the
+libjpeg v6b or v7 API/ABI (or with previous versions of libjpeg-turbo.) See
+[README.md](README.md) for more details.
+
+13. Added ARMv7s architecture to libjpeg.a and libturbojpeg.a in the official
+libjpeg-turbo binary package for OS X, so that those libraries can be used to
+build applications that leverage the faster CPUs in the iPhone 5 and iPad 4.
+
+
+1.2.1
+=====
+
+### Significant changes relative to 1.2.0:
+
+1. Creating or decoding a JPEG file that uses the RGB colorspace should now
+properly work when the input or output colorspace is one of the libjpeg-turbo
+colorspace extensions.
+
+2. When libjpeg-turbo was built without SIMD support and merged (non-fancy)
+upsampling was used along with an alpha-enabled colorspace during
+decompression, the unused byte of the decompressed pixels was not being set to
+0xFF. This has been fixed. TJUnitTest has also been extended to test for the
+correct behavior of the colorspace extensions when merged upsampling is used.
+
+3. Fixed a bug whereby the libjpeg-turbo SSE2 SIMD code would not preserve the
+upper 64 bits of xmm6 and xmm7 on Win64 platforms, which violated the Win64
+calling conventions.
+
+4. Fixed a regression (CVE-2012-2806) caused by 1.2.0[6] whereby decompressing
+corrupt JPEG images (specifically, images in which the component count was
+erroneously set to a large value) would cause libjpeg-turbo to segfault.
+
+5. Worked around a severe performance issue with "Bobcat" (AMD Embedded APU)
+processors. The `MASKMOVDQU` instruction, which was used by the libjpeg-turbo
+SSE2 SIMD code, is apparently implemented in microcode on AMD processors, and
+it is painfully slow on Bobcat processors in particular. Eliminating the use
+of this instruction improved performance by an order of magnitude on Bobcat
+processors and by a small amount (typically 5%) on AMD desktop processors.
+
+6. Added SIMD acceleration for performing 4:2:2 upsampling on NEON-capable ARM
+platforms. This speeds up the decompression of 4:2:2 JPEGs by 20-25% on such
+platforms.
+
+7. Fixed a regression caused by 1.2.0[2] whereby, on Linux/x86 platforms
+running the 32-bit SSE2 SIMD code in libjpeg-turbo, decompressing a 4:2:0 or
+4:2:2 JPEG image into a 32-bit (RGBX, BGRX, etc.) buffer without using fancy
+upsampling would produce several incorrect columns of pixels at the right-hand
+side of the output image if each row in the output image was not evenly
+divisible by 16 bytes.
+
+8. Fixed an issue whereby attempting to build the SIMD extensions with Xcode
+4.3 on OS X platforms would cause NASM to return numerous errors of the form
+"'%define' expects a macro identifier".
+
+9. Added flags to the TurboJPEG API that allow the caller to force the use of
+either the fast or the accurate DCT/IDCT algorithms in the underlying codec.
+
+
+1.2.0
+=====
+
+### Significant changes relative to 1.2 beta1:
+
+1. Fixed build issue with Yasm on Unix systems (the libjpeg-turbo build system
+was not adding the current directory to the assembler include path, so Yasm
+was not able to find jsimdcfg.inc.)
+
+2. Fixed out-of-bounds read in SSE2 SIMD code that occurred when decompressing
+a JPEG image to a bitmap buffer whose size was not a multiple of 16 bytes.
+This was more of an annoyance than an actual bug, since it did not cause any
+actual run-time problems, but the issue showed up when running libjpeg-turbo in
+valgrind. See <http://crbug.com/72399> for more information.
+
+3. Added a compile-time macro (`LIBJPEG_TURBO_VERSION`) that can be used to
+check the version of libjpeg-turbo against which an application was compiled.
+
+4. Added new RGBA/BGRA/ABGR/ARGB colorspace extension constants (libjpeg API)
+and pixel formats (TurboJPEG API), which allow applications to specify that,
+when decompressing to a 4-component RGB buffer, the unused byte should be set
+to 0xFF so that it can be interpreted as an opaque alpha channel.
+
+5. Fixed regression issue whereby DevIL failed to build against libjpeg-turbo
+because libjpeg-turbo's distributed version of jconfig.h contained an `INLINE`
+macro, which conflicted with a similar macro in DevIL. This macro is used only
+internally when building libjpeg-turbo, so it was moved into config.h.
+
+6. libjpeg-turbo will now correctly decompress erroneous CMYK/YCCK JPEGs whose
+K component is assigned a component ID of 1 instead of 4. Although these files
+are in violation of the spec, other JPEG implementations handle them
+correctly.
+
+7. Added ARMv6 and ARMv7 architectures to libjpeg.a and libturbojpeg.a in
+the official libjpeg-turbo binary package for OS X, so that those libraries can
+be used to build both OS X and iOS applications.
+
+
+1.1.90 (1.2 beta1)
+==================
+
+### Significant changes relative to 1.1.1:
+
+1. Added a Java wrapper for the TurboJPEG API. See [java/README](java/README)
+for more details.
+
+2. The TurboJPEG API can now be used to scale down images during
+decompression.
+
+3. Added SIMD routines for RGB-to-grayscale color conversion, which
+significantly improves the performance of grayscale JPEG compression from an
+RGB source image.
+
+4. Improved the performance of the C color conversion routines, which are used
+on platforms for which SIMD acceleration is not available.
+
+5. Added a function to the TurboJPEG API that performs lossless transforms.
+This function is implemented using the same back end as jpegtran, but it
+performs transcoding entirely in memory and allows multiple transforms and/or
+crop operations to be batched together, so the source coefficients only need to
+be read once. This is useful when generating image tiles from a single source
+JPEG.
+
+6. Added tests for the new TurboJPEG scaled decompression and lossless
+transform features to tjbench (the TurboJPEG benchmark, formerly called
+"jpgtest".)
+
+7. Added support for 4:4:0 (transposed 4:2:2) subsampling in TurboJPEG, which
+was necessary in order for it to read 4:2:2 JPEG files that had been losslessly
+transposed or rotated 90 degrees.
+
+8. All legacy VirtualGL code has been re-factored, and this has allowed
+libjpeg-turbo, in its entirety, to be re-licensed under a BSD-style license.
+
+9. libjpeg-turbo can now be built with Yasm.
+
+10. Added SIMD acceleration for ARM Linux and iOS platforms that support
+NEON instructions.
+
+11. Refactored the TurboJPEG C API and documented it using Doxygen. The
+TurboJPEG 1.2 API uses pixel formats to define the size and component order of
+the uncompressed source/destination images, and it includes a more efficient
+version of `TJBUFSIZE()` that computes a worst-case JPEG size based on the
+level of chrominance subsampling. The refactored implementation of the
+TurboJPEG API now uses the libjpeg memory source and destination managers,
+which allows the TurboJPEG compressor to grow the JPEG buffer as necessary.
+
+12. Eliminated errors in the output of jpegtran on Windows that occurred when
+the application was invoked using I/O redirection
+(`jpegtran <input.jpg >output.jpg`.)
+
+13. The inclusion of libjpeg v7 and v8 emulation as well as arithmetic coding
+support in libjpeg-turbo v1.1.0 introduced several new error constants in
+jerror.h, and these were mistakenly enabled for all emulation modes, causing
+the error enum in libjpeg-turbo to sometimes have different values than the
+same enum in libjpeg. This represents an ABI incompatibility, and it caused
+problems with rare applications that took specific action based on a particular
+error value. The fix was to include the new error constants conditionally
+based on whether libjpeg v7 or v8 emulation was enabled.
+
+14. Fixed an issue whereby Windows applications that used libjpeg-turbo would
+fail to compile if the Windows system headers were included before jpeglib.h.
+This issue was caused by a conflict in the definition of the INT32 type.
+
+15. Fixed 32-bit supplementary package for amd64 Debian systems, which was
+broken by enhancements to the packaging system in 1.1.
+
+16. When decompressing a JPEG image using an output colorspace of
+`JCS_EXT_RGBX`, `JCS_EXT_BGRX`, `JCS_EXT_XBGR`, or `JCS_EXT_XRGB`,
+libjpeg-turbo will now set the unused byte to 0xFF, which allows applications
+to interpret that byte as an alpha channel (0xFF = opaque).
+
+
+1.1.1
+=====
+
+### Significant changes relative to 1.1.0:
+
+1. Fixed a 1-pixel error in row 0, column 21 of the luminance plane generated
+by `tjEncodeYUV()`.
+
+2. libjpeg-turbo's accelerated Huffman decoder previously ignored unexpected
+markers found in the middle of the JPEG data stream during decompression. It
+will now hand off decoding of a particular block to the unaccelerated Huffman
+decoder if an unexpected marker is found, so that the unaccelerated Huffman
+decoder can generate an appropriate warning.
+
+3. Older versions of MinGW64 prefixed symbol names with underscores by
+default, which differed from the behavior of 64-bit Visual C++. MinGW64 1.0
+has adopted the behavior of 64-bit Visual C++ as the default, so to accommodate
+this, the libjpeg-turbo SIMD function names are no longer prefixed with an
+underscore when building with MinGW64. This means that, when building
+libjpeg-turbo with older versions of MinGW64, you will now have to add
+`-fno-leading-underscore` to the `CFLAGS`.
+
+4. Fixed a regression bug in the NSIS script that caused the Windows installer
+build to fail when using the Visual Studio IDE.
+
+5. Fixed a bug in `jpeg_read_coefficients()` whereby it would not initialize
+`cinfo->image_width` and `cinfo->image_height` if libjpeg v7 or v8 emulation
+was enabled. This specifically caused the jpegoptim program to fail if it was
+linked against a version of libjpeg-turbo that was built with libjpeg v7 or v8
+emulation.
+
+6. Eliminated excessive I/O overhead that occurred when reading BMP files in
+cjpeg.
+
+7. Eliminated errors in the output of cjpeg on Windows that occurred when the
+application was invoked using I/O redirection (`cjpeg <inputfile >output.jpg`.)
+
+
+1.1.0
+=====
+
+### Significant changes relative to 1.1 beta1:
+
+1. The algorithm used by the SIMD quantization function cannot produce correct
+results when the JPEG quality is >= 98 and the fast integer forward DCT is
+used. Thus, the non-SIMD quantization function is now used for those cases,
+and libjpeg-turbo should now produce identical output to libjpeg v6b in all
+cases.
+
+2. Despite the above, the fast integer forward DCT still degrades somewhat for
+JPEG qualities greater than 95, so the TurboJPEG wrapper will now automatically
+use the accurate integer forward DCT when generating JPEG images of quality 96
+or greater. This reduces compression performance by as much as 15% for these
+high-quality images but is necessary to ensure that the images are perceptually
+lossless. It also ensures that the library can avoid the performance pitfall
+created by [1].
+
+3. Ported jpgtest.cxx to pure C to avoid the need for a C++ compiler.
+
+4. Fixed visual artifacts in grayscale JPEG compression caused by a typo in
+the RGB-to-luminance lookup tables.
+
+5. The Windows distribution packages now include the libjpeg run-time programs
+(cjpeg, etc.)
+
+6. All packages now include jpgtest.
+
+7. The TurboJPEG dynamic library now uses versioned symbols.
+
+8. Added two new TurboJPEG API functions, `tjEncodeYUV()` and
+`tjDecompressToYUV()`, to replace the somewhat hackish `TJ_YUV` flag.
+
+
+1.0.90 (1.1 beta1)
+==================
+
+### Significant changes relative to 1.0.1:
+
+1. Added emulation of the libjpeg v7 and v8 APIs and ABIs. See
+[README.md](README.md) for more details. This feature was sponsored by
+CamTrace SAS.
+
+2. Created a new CMake-based build system for the Visual C++ and MinGW builds.
+
+3. Grayscale bitmaps can now be compressed from/decompressed to using the
+TurboJPEG API.
+
+4. jpgtest can now be used to test decompression performance with existing
+JPEG images.
+
+5. If the default install prefix (/opt/libjpeg-turbo) is used, then
+`make install` now creates /opt/libjpeg-turbo/lib32 and
+/opt/libjpeg-turbo/lib64 sym links to duplicate the behavior of the binary
+packages.
+
+6. All symbols in the libjpeg-turbo dynamic library are now versioned, even
+when the library is built with libjpeg v6b emulation.
+
+7. Added arithmetic encoding and decoding support (can be disabled with
+configure or CMake options)
+
+8. Added a `TJ_YUV` flag to the TurboJPEG API, which causes both the compressor
+and decompressor to output planar YUV images.
+
+9. Added an extended version of `tjDecompressHeader()` to the TurboJPEG API,
+which allows the caller to determine the type of subsampling used in a JPEG
+image.
+
+10. Added further protections against invalid Huffman codes.
+
+
+1.0.1
+=====
+
+### Significant changes relative to 1.0.0:
+
+1. The Huffman decoder will now handle erroneous Huffman codes (for instance,
+from a corrupt JPEG image.) Previously, these would cause libjpeg-turbo to
+crash under certain circumstances.
+
+2. Fixed typo in SIMD dispatch routines that was causing 4:2:2 upsampling to
+be used instead of 4:2:0 when decompressing JPEG images using SSE2 code.
+
+3. The configure script will now automatically determine whether the
+`INCOMPLETE_TYPES_BROKEN` macro should be defined.
+
+
+1.0.0
+=====
+
+### Significant changes relative to 0.0.93:
+
+1. 2983700: Further FreeBSD build tweaks (no longer necessary to specify
+`--host` when configuring on a 64-bit system)
+
+2. Created symlinks in the Unix/Linux packages so that the TurboJPEG
+include file can always be found in /opt/libjpeg-turbo/include, the 32-bit
+static libraries can always be found in /opt/libjpeg-turbo/lib32, and the
+64-bit static libraries can always be found in /opt/libjpeg-turbo/lib64.
+
+3. The Unix/Linux distribution packages now include the libjpeg run-time
+programs (cjpeg, etc.) and man pages.
+
+4. Created a 32-bit supplementary package for amd64 Debian systems, which
+contains just the 32-bit libjpeg-turbo libraries.
+
+5. Moved the libraries from */lib32 to */lib in the i386 Debian package.
+
+6. Include distribution package for Cygwin
+
+7. No longer necessary to specify `--without-simd` on non-x86 architectures,
+and unit tests now work on those architectures.
+
+
+0.0.93
+======
+
+### Significant changes since 0.0.91:
+
+1. 2982659: Fixed x86-64 build on FreeBSD systems
+
+2. 2988188: Added support for Windows 64-bit systems
+
+
+0.0.91
+======
+
+### Significant changes relative to 0.0.90:
+
+1. Added documentation to .deb packages
+
+2. 2968313: Fixed data corruption issues when decompressing large JPEG images
+and/or using buffered I/O with the libjpeg-turbo decompressor
+
+
+0.0.90
+======
+
+Initial release