ryan/mozjpeg
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

The Independent JPEG Group's JPEG software v5a

Browse Source
This commit is contained in:
Thomas G. Lane
1994-12-07 00:00:00 +00:00
committed by DRC
parent 36a4ccccd3
commit 9ba2f5ed36
37 changed files with 1734 additions and 1032 deletions
Download Patch File Download Diff File Expand all files Collapse all files

68
wrppm.c
View File

@@ -6,6 +6,7 @@
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains routines to write output images in PPM/PGM format.
* The extended 2-byte-per-sample raw PPM/PGM formats are supported.
* The PBMPLUS library is NOT required to compile this software
* (but it is highly useful as a set of PPM image manipulation programs).
*
@@ -20,18 +21,34 @@
/*
* Currently, this code only knows how to write raw PPM or PGM format,
* which can be no more than 8 bits/sample. As an expedient for testing
* 12-bit JPEG mode, we support writing 12-bit data to an 8-bit file by
* downscaling the values. Of course this implies loss of precision.
* For 12-bit JPEG data, we either downscale the values to 8 bits
* (to write standard byte-per-sample PPM/PGM files), or output
* nonstandard word-per-sample PPM/PGM files. Downscaling is done
* if PPM_NORAWWORD is defined (this can be done in the Makefile
* or in jconfig.h).
* (When the core library supports data precision reduction, a cleaner
* implementation will be to ask for that instead.)
*/
#if BITS_IN_JSAMPLE == 8
#define DOWNSCALE(x) (x)
#define PUTPPMSAMPLE(ptr,v) *ptr++ = (char) (v)
#define BYTESPERSAMPLE 1
#define PPM_MAXVAL 255
#else
#define DOWNSCALE(x) ((x) >> (BITS_IN_JSAMPLE-8))
#ifdef PPM_NORAWWORD
#define PUTPPMSAMPLE(ptr,v) *ptr++ = (char) ((v) >> (BITS_IN_JSAMPLE-8))
#define BYTESPERSAMPLE 1
#define PPM_MAXVAL 255
#else
/* The word-per-sample format always puts the LSB first. */
#define PUTPPMSAMPLE(ptr,v) \
{ register int val_ = v; \
*ptr++ = (char) (val_ & 0xFF); \
*ptr++ = (char) ((val_ >> 8) & 0xFF); \
}
#define BYTESPERSAMPLE 2
#define PPM_MAXVAL ((1<<BITS_IN_JSAMPLE)-1)
#endif
#endif
@@ -54,8 +71,8 @@ typedef struct {
/* Usually these two pointers point to the same place: */
char *iobuffer; /* fwrite's I/O buffer */
JSAMPROW pixrow; /* decompressor output buffer */
JDIMENSION buffer_width; /* width of one row */
size_t buffer_width; /* width of I/O buffer */
JDIMENSION samples_per_row; /* JSAMPLEs per output row */
} ppm_dest_struct;
typedef ppm_dest_struct * ppm_dest_ptr;
@@ -80,8 +97,8 @@ put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
/*
* This code is used when we have to copy the data because JSAMPLE is not
* the same size as char. Typically this only happens in 12-bit mode.
* This code is used when we have to copy the data and apply a pixel
* format translation. Typically this only happens in 12-bit mode.
*/
METHODDEF void
@@ -95,8 +112,8 @@ copy_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
ptr = dest->pub.buffer[0];
bufferptr = dest->iobuffer;
for (col = dest->buffer_width; col > 0; col--) {
*bufferptr++ = (char) DOWNSCALE(GETJSAMPLE(*ptr++));
for (col = dest->samples_per_row; col > 0; col--) {
PUTPPMSAMPLE(bufferptr, GETJSAMPLE(*ptr++));
}
(void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
}
@@ -124,9 +141,9 @@ put_demapped_rgb (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
bufferptr = dest->iobuffer;
for (col = cinfo->output_width; col > 0; col--) {
pixval = GETJSAMPLE(*ptr++);
*bufferptr++ = (char) DOWNSCALE(GETJSAMPLE(color_map0[pixval]));
*bufferptr++ = (char) DOWNSCALE(GETJSAMPLE(color_map1[pixval]));
*bufferptr++ = (char) DOWNSCALE(GETJSAMPLE(color_map2[pixval]));
PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map0[pixval]));
PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map1[pixval]));
PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map2[pixval]));
}
(void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
}
@@ -145,7 +162,7 @@ put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
ptr = dest->pub.buffer[0];
bufferptr = dest->iobuffer;
for (col = cinfo->output_width; col > 0; col--) {
*bufferptr++ = (char) DOWNSCALE(GETJSAMPLE(color_map[GETJSAMPLE(*ptr++)]));
PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map[GETJSAMPLE(*ptr++)]));
}
(void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
}
@@ -165,12 +182,14 @@ start_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
case JCS_GRAYSCALE:
/* emit header for raw PGM format */
fprintf(dest->pub.output_file, "P5\n%ld %ld\n%d\n",
(long) cinfo->output_width, (long) cinfo->output_height, 255);
(long) cinfo->output_width, (long) cinfo->output_height,
PPM_MAXVAL);
break;
case JCS_RGB:
/* emit header for raw PPM format */
fprintf(dest->pub.output_file, "P6\n%ld %ld\n%d\n",
(long) cinfo->output_width, (long) cinfo->output_height, 255);
(long) cinfo->output_width, (long) cinfo->output_height,
PPM_MAXVAL);
break;
default:
ERREXIT(cinfo, JERR_PPM_COLORSPACE);
@@ -212,15 +231,16 @@ jinit_write_ppm (j_decompress_ptr cinfo)
jpeg_calc_output_dimensions(cinfo);
/* Create physical I/O buffer. Note we make this near on a PC. */
dest->buffer_width = cinfo->output_width * cinfo->out_color_components;
dest->iobuffer = (char *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(size_t) (dest->buffer_width * SIZEOF(char)));
dest->samples_per_row = cinfo->output_width * cinfo->out_color_components;
dest->buffer_width = dest->samples_per_row * (BYTESPERSAMPLE * SIZEOF(char));
dest->iobuffer = (char *) (*cinfo->mem->alloc_small)
((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width);
if (cinfo->quantize_colors || SIZEOF(JSAMPLE) != SIZEOF(char)) {
if (cinfo->quantize_colors || BITS_IN_JSAMPLE != 8 ||
SIZEOF(JSAMPLE) != SIZEOF(char)) {
/* When quantizing, we need an output buffer for colormap indexes
* that's separate from the physical I/O buffer. We also need a
* separate buffer if JSAMPLE and char are not the same size.
* separate buffer if pixel format translation must take place.
*/
dest->pub.buffer = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,