workbench/libs/jpeg/wrppm.c

   1 /*
   2  * wrppm.c
   3  *
   4  * Copyright (C) 1991-1996, Thomas G. Lane.
   5  * Modified 2009 by Guido Vollbeding.
   6  * This file is part of the Independent JPEG Group's software.
   7  * For conditions of distribution and use, see the accompanying README file.
   8  *
   9  * This file contains routines to write output images in PPM/PGM format.
  10  * The extended 2-byte-per-sample raw PPM/PGM formats are supported.
  11  * The PBMPLUS library is NOT required to compile this software
  12  * (but it is highly useful as a set of PPM image manipulation programs).
  13  *
  14  * These routines may need modification for non-Unix environments or
  15  * specialized applications.  As they stand, they assume output to
  16  * an ordinary stdio stream.
  17  */
  18
  19 #include "cdjpeg.h"             /* Common decls for cjpeg/djpeg applications */
  20
  21 #ifdef PPM_SUPPORTED
  22
  23
  24 /*
  25  * For 12-bit JPEG data, we either downscale the values to 8 bits
  26  * (to write standard byte-per-sample PPM/PGM files), or output
  27  * nonstandard word-per-sample PPM/PGM files.  Downscaling is done
  28  * if PPM_NORAWWORD is defined (this can be done in the Makefile
  29  * or in jconfig.h).
  30  * (When the core library supports data precision reduction, a cleaner
  31  * implementation will be to ask for that instead.)
  32  */
  33
  34 #if BITS_IN_JSAMPLE == 8
  35 #define PUTPPMSAMPLE(ptr,v)  *ptr++ = (char) (v)
  36 #define BYTESPERSAMPLE 1
  37 #define PPM_MAXVAL 255
  38 #else
  39 #ifdef PPM_NORAWWORD
  40 #define PUTPPMSAMPLE(ptr,v)  *ptr++ = (char) ((v) >> (BITS_IN_JSAMPLE-8))
  41 #define BYTESPERSAMPLE 1
  42 #define PPM_MAXVAL 255
  43 #else
  44 /* The word-per-sample format always puts the MSB first. */
  45 #define PUTPPMSAMPLE(ptr,v)                     \
  46         { register int val_ = v;                \
  47           *ptr++ = (char) ((val_ >> 8) & 0xFF); \
  48           *ptr++ = (char) (val_ & 0xFF);        \
  49         }
  50 #define BYTESPERSAMPLE 2
  51 #define PPM_MAXVAL ((1<<BITS_IN_JSAMPLE)-1)
  52 #endif
  53 #endif
  54
  55
  56 /*
  57  * When JSAMPLE is the same size as char, we can just fwrite() the
  58  * decompressed data to the PPM or PGM file.  On PCs, in order to make this
  59  * work the output buffer must be allocated in near data space, because we are
  60  * assuming small-data memory model wherein fwrite() can't reach far memory.
  61  * If you need to process very wide images on a PC, you might have to compile
  62  * in large-memory model, or else replace fwrite() with a putc() loop ---
  63  * which will be much slower.
  64  */
  65
  66
  67 /* Private version of data destination object */
  68
  69 typedef struct {
  70   struct djpeg_dest_struct pub; /* public fields */
  71
  72   /* Usually these two pointers point to the same place: */
  73   char *iobuffer;               /* fwrite's I/O buffer */
  74   JSAMPROW pixrow;              /* decompressor output buffer */
  75   size_t buffer_width;          /* width of I/O buffer */
  76   JDIMENSION samples_per_row;   /* JSAMPLEs per output row */
  77 } ppm_dest_struct;
  78
  79 typedef ppm_dest_struct * ppm_dest_ptr;
  80
  81
  82 /*
  83  * Write some pixel data.
  84  * In this module rows_supplied will always be 1.
  85  *
  86  * put_pixel_rows handles the "normal" 8-bit case where the decompressor
  87  * output buffer is physically the same as the fwrite buffer.
  88  */
  89
  90 METHODDEF(void)
  91 put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
  92                 JDIMENSION rows_supplied)
  93 {
  94   ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
  95
  96   (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
  97 }
  98
  99
 100 /*
 101  * This code is used when we have to copy the data and apply a pixel
 102  * format translation.  Typically this only happens in 12-bit mode.
 103  */
 104
 105 METHODDEF(void)
 106 copy_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
 107                  JDIMENSION rows_supplied)
 108 {
 109   ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
 110   register char * bufferptr;
 111   register JSAMPROW ptr;
 112   register JDIMENSION col;
 113
 114   ptr = dest->pub.buffer[0];
 115   bufferptr = dest->iobuffer;
 116   for (col = dest->samples_per_row; col > 0; col--) {
 117     PUTPPMSAMPLE(bufferptr, GETJSAMPLE(*ptr++));
 118   }
 119   (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
 120 }
 121
 122
 123 /*
 124  * Write some pixel data when color quantization is in effect.
 125  * We have to demap the color index values to straight data.
 126  */
 127
 128 METHODDEF(void)
 129 put_demapped_rgb (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
 130                   JDIMENSION rows_supplied)
 131 {
 132   ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
 133   register char * bufferptr;
 134   register int pixval;
 135   register JSAMPROW ptr;
 136   register JSAMPROW color_map0 = cinfo->colormap[0];
 137   register JSAMPROW color_map1 = cinfo->colormap[1];
 138   register JSAMPROW color_map2 = cinfo->colormap[2];
 139   register JDIMENSION col;
 140
 141   ptr = dest->pub.buffer[0];
 142   bufferptr = dest->iobuffer;
 143   for (col = cinfo->output_width; col > 0; col--) {
 144     pixval = GETJSAMPLE(*ptr++);
 145     PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map0[pixval]));
 146     PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map1[pixval]));
 147     PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map2[pixval]));
 148   }
 149   (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
 150 }
 151
 152
 153 METHODDEF(void)
 154 put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
 155                    JDIMENSION rows_supplied)
 156 {
 157   ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
 158   register char * bufferptr;
 159   register JSAMPROW ptr;
 160   register JSAMPROW color_map = cinfo->colormap[0];
 161   register JDIMENSION col;
 162
 163   ptr = dest->pub.buffer[0];
 164   bufferptr = dest->iobuffer;
 165   for (col = cinfo->output_width; col > 0; col--) {
 166     PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map[GETJSAMPLE(*ptr++)]));
 167   }
 168   (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
 169 }
 170
 171
 172 /*
 173  * Startup: write the file header.
 174  */
 175
 176 METHODDEF(void)
 177 start_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
 178 {
 179   ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
 180
 181   /* Emit file header */
 182   switch (cinfo->out_color_space) {
 183   case JCS_GRAYSCALE:
 184     /* emit header for raw PGM format */
 185     fprintf(dest->pub.output_file, "P5\n%ld %ld\n%d\n",
 186             (long) cinfo->output_width, (long) cinfo->output_height,
 187             PPM_MAXVAL);
 188     break;
 189   case JCS_RGB:
 190     /* emit header for raw PPM format */
 191     fprintf(dest->pub.output_file, "P6\n%ld %ld\n%d\n",
 192             (long) cinfo->output_width, (long) cinfo->output_height,
 193             PPM_MAXVAL);
 194     break;
 195   default:
 196     ERREXIT(cinfo, JERR_PPM_COLORSPACE);
 197   }
 198 }
 199
 200
 201 /*
 202  * Finish up at the end of the file.
 203  */
 204
 205 METHODDEF(void)
 206 finish_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
 207 {
 208   /* Make sure we wrote the output file OK */
 209   fflush(dinfo->output_file);
 210   if (ferror(dinfo->output_file))
 211     ERREXIT(cinfo, JERR_FILE_WRITE);
 212 }
 213
 214
 215 /*
 216  * The module selection routine for PPM format output.
 217  */
 218
 219 GLOBAL(djpeg_dest_ptr)
 220 jinit_write_ppm (j_decompress_ptr cinfo)
 221 {
 222   ppm_dest_ptr dest;
 223
 224   /* Create module interface object, fill in method pointers */
 225   dest = (ppm_dest_ptr)
 226       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
 227                                   SIZEOF(ppm_dest_struct));
 228   dest->pub.start_output = start_output_ppm;
 229   dest->pub.finish_output = finish_output_ppm;
 230
 231   /* Calculate output image dimensions so we can allocate space */
 232   jpeg_calc_output_dimensions(cinfo);
 233
 234   /* Create physical I/O buffer.  Note we make this near on a PC. */
 235   dest->samples_per_row = cinfo->output_width * cinfo->out_color_components;
 236   dest->buffer_width = dest->samples_per_row * (BYTESPERSAMPLE * SIZEOF(char));
 237   dest->iobuffer = (char *) (*cinfo->mem->alloc_small)
 238     ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width);
 239
 240   if (cinfo->quantize_colors || BITS_IN_JSAMPLE != 8 ||
 241       SIZEOF(JSAMPLE) != SIZEOF(char)) {
 242     /* When quantizing, we need an output buffer for colormap indexes
 243      * that's separate from the physical I/O buffer.  We also need a
 244      * separate buffer if pixel format translation must take place.
 245      */
 246     dest->pub.buffer = (*cinfo->mem->alloc_sarray)
 247       ((j_common_ptr) cinfo, JPOOL_IMAGE,
 248        cinfo->output_width * cinfo->output_components, (JDIMENSION) 1);
 249     dest->pub.buffer_height = 1;
 250     if (! cinfo->quantize_colors)
 251       dest->pub.put_pixel_rows = copy_pixel_rows;
 252     else if (cinfo->out_color_space == JCS_GRAYSCALE)
 253       dest->pub.put_pixel_rows = put_demapped_gray;
 254     else
 255       dest->pub.put_pixel_rows = put_demapped_rgb;
 256   } else {
 257     /* We will fwrite() directly from decompressor output buffer. */
 258     /* Synthesize a JSAMPARRAY pointer structure */
 259     /* Cast here implies near->far pointer conversion on PCs */
 260     dest->pixrow = (JSAMPROW) dest->iobuffer;
 261     dest->pub.buffer = & dest->pixrow;
 262     dest->pub.buffer_height = 1;
 263     dest->pub.put_pixel_rows = put_pixel_rows;
 264   }
 265
 266   return (djpeg_dest_ptr) dest;
 267 }
 268
 269 #endif /* PPM_SUPPORTED */