source: trunk/libjpeg/wrppm.c @ 15

Last change on this file since 15 was 15, checked in by Eugene Romanenko, 16 years ago

needed libs update

File size: 8.4 KB
Line 
1/*
2 * wrppm.c
3 *
4 * Copyright (C) 1991-1996, Thomas G. Lane.
5 * This file is part of the Independent JPEG Group's software.
6 * For conditions of distribution and use, see the accompanying README file.
7 *
8 * This file contains routines to write output images in PPM/PGM format.
9 * The extended 2-byte-per-sample raw PPM/PGM formats are supported.
10 * The PBMPLUS library is NOT required to compile this software
11 * (but it is highly useful as a set of PPM image manipulation programs).
12 *
13 * These routines may need modification for non-Unix environments or
14 * specialized applications.  As they stand, they assume output to
15 * an ordinary stdio stream.
16 */
17
18#include "cdjpeg.h"             /* Common decls for cjpeg/djpeg applications */
19
20#ifdef PPM_SUPPORTED
21
22
23/*
24 * For 12-bit JPEG data, we either downscale the values to 8 bits
25 * (to write standard byte-per-sample PPM/PGM files), or output
26 * nonstandard word-per-sample PPM/PGM files.  Downscaling is done
27 * if PPM_NORAWWORD is defined (this can be done in the Makefile
28 * or in jconfig.h).
29 * (When the core library supports data precision reduction, a cleaner
30 * implementation will be to ask for that instead.)
31 */
32
33#if BITS_IN_JSAMPLE == 8
34#define PUTPPMSAMPLE(ptr,v)  *ptr++ = (char) (v)
35#define BYTESPERSAMPLE 1
36#define PPM_MAXVAL 255
37#else
38#ifdef PPM_NORAWWORD
39#define PUTPPMSAMPLE(ptr,v)  *ptr++ = (char) ((v) >> (BITS_IN_JSAMPLE-8))
40#define BYTESPERSAMPLE 1
41#define PPM_MAXVAL 255
42#else
43/* The word-per-sample format always puts the LSB first. */
44#define PUTPPMSAMPLE(ptr,v)                     \
45        { register int val_ = v;                \
46          *ptr++ = (char) (val_ & 0xFF);        \
47          *ptr++ = (char) ((val_ >> 8) & 0xFF); \
48        }
49#define BYTESPERSAMPLE 2
50#define PPM_MAXVAL ((1<<BITS_IN_JSAMPLE)-1)
51#endif
52#endif
53
54
55/*
56 * When JSAMPLE is the same size as char, we can just fwrite() the
57 * decompressed data to the PPM or PGM file.  On PCs, in order to make this
58 * work the output buffer must be allocated in near data space, because we are
59 * assuming small-data memory model wherein fwrite() can't reach far memory.
60 * If you need to process very wide images on a PC, you might have to compile
61 * in large-memory model, or else replace fwrite() with a putc() loop ---
62 * which will be much slower.
63 */
64
65
66/* Private version of data destination object */
67
68typedef struct {
69  struct djpeg_dest_struct pub; /* public fields */
70
71  /* Usually these two pointers point to the same place: */
72  char *iobuffer;               /* fwrite's I/O buffer */
73  JSAMPROW pixrow;              /* decompressor output buffer */
74  size_t buffer_width;          /* width of I/O buffer */
75  JDIMENSION samples_per_row;   /* JSAMPLEs per output row */
76} ppm_dest_struct;
77
78typedef ppm_dest_struct * ppm_dest_ptr;
79
80
81/*
82 * Write some pixel data.
83 * In this module rows_supplied will always be 1.
84 *
85 * put_pixel_rows handles the "normal" 8-bit case where the decompressor
86 * output buffer is physically the same as the fwrite buffer.
87 */
88
89METHODDEF(void)
90put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
91                JDIMENSION rows_supplied)
92{
93  ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
94
95  (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
96}
97
98
99/*
100 * This code is used when we have to copy the data and apply a pixel
101 * format translation.  Typically this only happens in 12-bit mode.
102 */
103
104METHODDEF(void)
105copy_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
106                 JDIMENSION rows_supplied)
107{
108  ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
109  register char * bufferptr;
110  register JSAMPROW ptr;
111  register JDIMENSION col;
112
113  ptr = dest->pub.buffer[0];
114  bufferptr = dest->iobuffer;
115  for (col = dest->samples_per_row; col > 0; col--) {
116    PUTPPMSAMPLE(bufferptr, GETJSAMPLE(*ptr++));
117  }
118  (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
119}
120
121
122/*
123 * Write some pixel data when color quantization is in effect.
124 * We have to demap the color index values to straight data.
125 */
126
127METHODDEF(void)
128put_demapped_rgb (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
129                  JDIMENSION rows_supplied)
130{
131  ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
132  register char * bufferptr;
133  register int pixval;
134  register JSAMPROW ptr;
135  register JSAMPROW color_map0 = cinfo->colormap[0];
136  register JSAMPROW color_map1 = cinfo->colormap[1];
137  register JSAMPROW color_map2 = cinfo->colormap[2];
138  register JDIMENSION col;
139
140  ptr = dest->pub.buffer[0];
141  bufferptr = dest->iobuffer;
142  for (col = cinfo->output_width; col > 0; col--) {
143    pixval = GETJSAMPLE(*ptr++);
144    PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map0[pixval]));
145    PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map1[pixval]));
146    PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map2[pixval]));
147  }
148  (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
149}
150
151
152METHODDEF(void)
153put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
154                   JDIMENSION rows_supplied)
155{
156  ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
157  register char * bufferptr;
158  register JSAMPROW ptr;
159  register JSAMPROW color_map = cinfo->colormap[0];
160  register JDIMENSION col;
161
162  ptr = dest->pub.buffer[0];
163  bufferptr = dest->iobuffer;
164  for (col = cinfo->output_width; col > 0; col--) {
165    PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map[GETJSAMPLE(*ptr++)]));
166  }
167  (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
168}
169
170
171/*
172 * Startup: write the file header.
173 */
174
175METHODDEF(void)
176start_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
177{
178  ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
179
180  /* Emit file header */
181  switch (cinfo->out_color_space) {
182  case JCS_GRAYSCALE:
183    /* emit header for raw PGM format */
184    fprintf(dest->pub.output_file, "P5\n%ld %ld\n%d\n",
185            (long) cinfo->output_width, (long) cinfo->output_height,
186            PPM_MAXVAL);
187    break;
188  case JCS_RGB:
189    /* emit header for raw PPM format */
190    fprintf(dest->pub.output_file, "P6\n%ld %ld\n%d\n",
191            (long) cinfo->output_width, (long) cinfo->output_height,
192            PPM_MAXVAL);
193    break;
194  default:
195    ERREXIT(cinfo, JERR_PPM_COLORSPACE);
196  }
197}
198
199
200/*
201 * Finish up at the end of the file.
202 */
203
204METHODDEF(void)
205finish_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
206{
207  /* Make sure we wrote the output file OK */
208  fflush(dinfo->output_file);
209  if (ferror(dinfo->output_file))
210    ERREXIT(cinfo, JERR_FILE_WRITE);
211}
212
213
214/*
215 * The module selection routine for PPM format output.
216 */
217
218GLOBAL(djpeg_dest_ptr)
219jinit_write_ppm (j_decompress_ptr cinfo)
220{
221  ppm_dest_ptr dest;
222
223  /* Create module interface object, fill in method pointers */
224  dest = (ppm_dest_ptr)
225      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
226                                  SIZEOF(ppm_dest_struct));
227  dest->pub.start_output = start_output_ppm;
228  dest->pub.finish_output = finish_output_ppm;
229
230  /* Calculate output image dimensions so we can allocate space */
231  jpeg_calc_output_dimensions(cinfo);
232
233  /* Create physical I/O buffer.  Note we make this near on a PC. */
234  dest->samples_per_row = cinfo->output_width * cinfo->out_color_components;
235  dest->buffer_width = dest->samples_per_row * (BYTESPERSAMPLE * SIZEOF(char));
236  dest->iobuffer = (char *) (*cinfo->mem->alloc_small)
237    ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width);
238
239  if (cinfo->quantize_colors || BITS_IN_JSAMPLE != 8 ||
240      SIZEOF(JSAMPLE) != SIZEOF(char)) {
241    /* When quantizing, we need an output buffer for colormap indexes
242     * that's separate from the physical I/O buffer.  We also need a
243     * separate buffer if pixel format translation must take place.
244     */
245    dest->pub.buffer = (*cinfo->mem->alloc_sarray)
246      ((j_common_ptr) cinfo, JPOOL_IMAGE,
247       cinfo->output_width * cinfo->output_components, (JDIMENSION) 1);
248    dest->pub.buffer_height = 1;
249    if (! cinfo->quantize_colors)
250      dest->pub.put_pixel_rows = copy_pixel_rows;
251    else if (cinfo->out_color_space == JCS_GRAYSCALE)
252      dest->pub.put_pixel_rows = put_demapped_gray;
253    else
254      dest->pub.put_pixel_rows = put_demapped_rgb;
255  } else {
256    /* We will fwrite() directly from decompressor output buffer. */
257    /* Synthesize a JSAMPARRAY pointer structure */
258    /* Cast here implies near->far pointer conversion on PCs */
259    dest->pixrow = (JSAMPROW) dest->iobuffer;
260    dest->pub.buffer = & dest->pixrow;
261    dest->pub.buffer_height = 1;
262    dest->pub.put_pixel_rows = put_pixel_rows;
263  }
264
265  return (djpeg_dest_ptr) dest;
266}
267
268#endif /* PPM_SUPPORTED */
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