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Diffstat (limited to 'media/libjpeg/jcicc.c')
-rw-r--r-- | media/libjpeg/jcicc.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/media/libjpeg/jcicc.c b/media/libjpeg/jcicc.c new file mode 100644 index 0000000000..11037ff694 --- /dev/null +++ b/media/libjpeg/jcicc.c @@ -0,0 +1,105 @@ +/* + * jcicc.c + * + * Copyright (C) 1997-1998, Thomas G. Lane, Todd Newman. + * Copyright (C) 2017, D. R. Commander. + * For conditions of distribution and use, see the accompanying README.ijg + * file. + * + * This file provides code to write International Color Consortium (ICC) device + * profiles embedded in JFIF JPEG image files. The ICC has defined a standard + * for including such data in JPEG "APP2" markers. The code given here does + * not know anything about the internal structure of the ICC profile data; it + * just knows how to embed the profile data in a JPEG file while writing it. + */ + +#define JPEG_INTERNALS +#include "jinclude.h" +#include "jpeglib.h" +#include "jerror.h" + + +/* + * Since an ICC profile can be larger than the maximum size of a JPEG marker + * (64K), we need provisions to split it into multiple markers. The format + * defined by the ICC specifies one or more APP2 markers containing the + * following data: + * Identifying string ASCII "ICC_PROFILE\0" (12 bytes) + * Marker sequence number 1 for first APP2, 2 for next, etc (1 byte) + * Number of markers Total number of APP2's used (1 byte) + * Profile data (remainder of APP2 data) + * Decoders should use the marker sequence numbers to reassemble the profile, + * rather than assuming that the APP2 markers appear in the correct sequence. + */ + +#define ICC_MARKER (JPEG_APP0 + 2) /* JPEG marker code for ICC */ +#define ICC_OVERHEAD_LEN 14 /* size of non-profile data in APP2 */ +#define MAX_BYTES_IN_MARKER 65533 /* maximum data len of a JPEG marker */ +#define MAX_DATA_BYTES_IN_MARKER (MAX_BYTES_IN_MARKER - ICC_OVERHEAD_LEN) + + +/* + * This routine writes the given ICC profile data into a JPEG file. It *must* + * be called AFTER calling jpeg_start_compress() and BEFORE the first call to + * jpeg_write_scanlines(). (This ordering ensures that the APP2 marker(s) will + * appear after the SOI and JFIF or Adobe markers, but before all else.) + */ + +GLOBAL(void) +jpeg_write_icc_profile(j_compress_ptr cinfo, const JOCTET *icc_data_ptr, + unsigned int icc_data_len) +{ + unsigned int num_markers; /* total number of markers we'll write */ + int cur_marker = 1; /* per spec, counting starts at 1 */ + unsigned int length; /* number of bytes to write in this marker */ + + if (icc_data_ptr == NULL || icc_data_len == 0) + ERREXIT(cinfo, JERR_BUFFER_SIZE); + if (cinfo->global_state < CSTATE_SCANNING) + ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); + + /* Calculate the number of markers we'll need, rounding up of course */ + num_markers = icc_data_len / MAX_DATA_BYTES_IN_MARKER; + if (num_markers * MAX_DATA_BYTES_IN_MARKER != icc_data_len) + num_markers++; + + while (icc_data_len > 0) { + /* length of profile to put in this marker */ + length = icc_data_len; + if (length > MAX_DATA_BYTES_IN_MARKER) + length = MAX_DATA_BYTES_IN_MARKER; + icc_data_len -= length; + + /* Write the JPEG marker header (APP2 code and marker length) */ + jpeg_write_m_header(cinfo, ICC_MARKER, + (unsigned int)(length + ICC_OVERHEAD_LEN)); + + /* Write the marker identifying string "ICC_PROFILE" (null-terminated). We + * code it in this less-than-transparent way so that the code works even if + * the local character set is not ASCII. + */ + jpeg_write_m_byte(cinfo, 0x49); + jpeg_write_m_byte(cinfo, 0x43); + jpeg_write_m_byte(cinfo, 0x43); + jpeg_write_m_byte(cinfo, 0x5F); + jpeg_write_m_byte(cinfo, 0x50); + jpeg_write_m_byte(cinfo, 0x52); + jpeg_write_m_byte(cinfo, 0x4F); + jpeg_write_m_byte(cinfo, 0x46); + jpeg_write_m_byte(cinfo, 0x49); + jpeg_write_m_byte(cinfo, 0x4C); + jpeg_write_m_byte(cinfo, 0x45); + jpeg_write_m_byte(cinfo, 0x0); + + /* Add the sequencing info */ + jpeg_write_m_byte(cinfo, cur_marker); + jpeg_write_m_byte(cinfo, (int)num_markers); + + /* Add the profile data */ + while (length--) { + jpeg_write_m_byte(cinfo, *icc_data_ptr); + icc_data_ptr++; + } + cur_marker++; + } +} |