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/src/FreeImage/Source/LibJPEG/wrppm.c

https://bitbucket.org/cabalistic/ogredeps/
C | 269 lines | 150 code | 43 blank | 76 comment | 15 complexity | 4d88f18e273d3e21e7ca001a9c9e1e6f MD5 | raw file
  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
 69typedef 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
 79typedef 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
 90METHODDEF(void)
 91put_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
105METHODDEF(void)
106copy_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
128METHODDEF(void)
129put_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
153METHODDEF(void)
154put_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
176METHODDEF(void)
177start_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
205METHODDEF(void)
206finish_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
219GLOBAL(djpeg_dest_ptr)
220jinit_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 */