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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