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Diffstat (limited to 'libjpegtwrp/wrppm.c')
| -rw-r--r-- | libjpegtwrp/wrppm.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/libjpegtwrp/wrppm.c b/libjpegtwrp/wrppm.c new file mode 100644 index 000000000..6c6d90881 --- /dev/null +++ b/libjpegtwrp/wrppm.c @@ -0,0 +1,268 @@ +/* + * wrppm.c + * + * Copyright (C) 1991-1996, Thomas G. Lane. + * This file is part of the Independent JPEG Group's software. + * 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). + * + * These routines may need modification for non-Unix environments or + * specialized applications. As they stand, they assume output to + * an ordinary stdio stream. + */ + +#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */ + +#ifdef PPM_SUPPORTED + + +/* + * 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 PUTPPMSAMPLE(ptr,v) *ptr++ = (char) (v) +#define BYTESPERSAMPLE 1 +#define PPM_MAXVAL 255 +#else +#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 + + +/* + * When JSAMPLE is the same size as char, we can just fwrite() the + * decompressed data to the PPM or PGM file. On PCs, in order to make this + * work the output buffer must be allocated in near data space, because we are + * assuming small-data memory model wherein fwrite() can't reach far memory. + * If you need to process very wide images on a PC, you might have to compile + * in large-memory model, or else replace fwrite() with a putc() loop --- + * which will be much slower. + */ + + +/* Private version of data destination object */ + +typedef struct { + struct djpeg_dest_struct pub; /* public fields */ + + /* Usually these two pointers point to the same place: */ + char *iobuffer; /* fwrite's I/O buffer */ + JSAMPROW pixrow; /* decompressor output buffer */ + 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; + + +/* + * Write some pixel data. + * In this module rows_supplied will always be 1. + * + * put_pixel_rows handles the "normal" 8-bit case where the decompressor + * output buffer is physically the same as the fwrite buffer. + */ + +METHODDEF(void) +put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, + JDIMENSION rows_supplied) +{ + ppm_dest_ptr dest = (ppm_dest_ptr) dinfo; + + (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); +} + + +/* + * 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) +copy_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, + JDIMENSION rows_supplied) +{ + ppm_dest_ptr dest = (ppm_dest_ptr) dinfo; + register char * bufferptr; + register JSAMPROW ptr; + register JDIMENSION col; + + ptr = dest->pub.buffer[0]; + bufferptr = dest->iobuffer; + for (col = dest->samples_per_row; col > 0; col--) { + PUTPPMSAMPLE(bufferptr, GETJSAMPLE(*ptr++)); + } + (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); +} + + +/* + * Write some pixel data when color quantization is in effect. + * We have to demap the color index values to straight data. + */ + +METHODDEF(void) +put_demapped_rgb (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, + JDIMENSION rows_supplied) +{ + ppm_dest_ptr dest = (ppm_dest_ptr) dinfo; + register char * bufferptr; + register int pixval; + register JSAMPROW ptr; + register JSAMPROW color_map0 = cinfo->colormap[0]; + register JSAMPROW color_map1 = cinfo->colormap[1]; + register JSAMPROW color_map2 = cinfo->colormap[2]; + register JDIMENSION col; + + ptr = dest->pub.buffer[0]; + bufferptr = dest->iobuffer; + for (col = cinfo->output_width; col > 0; col--) { + pixval = GETJSAMPLE(*ptr++); + 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); +} + + +METHODDEF(void) +put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, + JDIMENSION rows_supplied) +{ + ppm_dest_ptr dest = (ppm_dest_ptr) dinfo; + register char * bufferptr; + register JSAMPROW ptr; + register JSAMPROW color_map = cinfo->colormap[0]; + register JDIMENSION col; + + ptr = dest->pub.buffer[0]; + bufferptr = dest->iobuffer; + for (col = cinfo->output_width; col > 0; col--) { + PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map[GETJSAMPLE(*ptr++)])); + } + (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); +} + + +/* + * Startup: write the file header. + */ + +METHODDEF(void) +start_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) +{ + ppm_dest_ptr dest = (ppm_dest_ptr) dinfo; + + /* Emit file header */ + switch (cinfo->out_color_space) { + 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, + 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, + PPM_MAXVAL); + break; + default: + ERREXIT(cinfo, JERR_PPM_COLORSPACE); + } +} + + +/* + * Finish up at the end of the file. + */ + +METHODDEF(void) +finish_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) +{ + /* Make sure we wrote the output file OK */ + fflush(dinfo->output_file); + if (ferror(dinfo->output_file)) + ERREXIT(cinfo, JERR_FILE_WRITE); +} + + +/* + * The module selection routine for PPM format output. + */ + +GLOBAL(djpeg_dest_ptr) +jinit_write_ppm (j_decompress_ptr cinfo) +{ + ppm_dest_ptr dest; + + /* Create module interface object, fill in method pointers */ + dest = (ppm_dest_ptr) + (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, + SIZEOF(ppm_dest_struct)); + dest->pub.start_output = start_output_ppm; + dest->pub.finish_output = finish_output_ppm; + + /* Calculate output image dimensions so we can allocate space */ + jpeg_calc_output_dimensions(cinfo); + + /* Create physical I/O buffer. Note we make this near on a PC. */ + 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 || 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 pixel format translation must take place. + */ + dest->pub.buffer = (*cinfo->mem->alloc_sarray) + ((j_common_ptr) cinfo, JPOOL_IMAGE, + cinfo->output_width * cinfo->output_components, (JDIMENSION) 1); + dest->pub.buffer_height = 1; + if (! cinfo->quantize_colors) + dest->pub.put_pixel_rows = copy_pixel_rows; + else if (cinfo->out_color_space == JCS_GRAYSCALE) + dest->pub.put_pixel_rows = put_demapped_gray; + else + dest->pub.put_pixel_rows = put_demapped_rgb; + } else { + /* We will fwrite() directly from decompressor output buffer. */ + /* Synthesize a JSAMPARRAY pointer structure */ + /* Cast here implies near->far pointer conversion on PCs */ + dest->pixrow = (JSAMPROW) dest->iobuffer; + dest->pub.buffer = & dest->pixrow; + dest->pub.buffer_height = 1; + dest->pub.put_pixel_rows = put_pixel_rows; + } + + return (djpeg_dest_ptr) dest; +} + +#endif /* PPM_SUPPORTED */ |