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