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1 /*
2  * rdppm.c
3  *
4  * This file was part of the Independent JPEG Group's software:
5  * Copyright (C) 1991-1997, Thomas G. Lane.
6  * Modified 2009 by Bill Allombert, Guido Vollbeding.
7  * libjpeg-turbo Modifications:
8  * Copyright (C) 2015-2017, 2020-2021, D. R. Commander.
9  * For conditions of distribution and use, see the accompanying README.ijg
10  * file.
11  *
12  * This file contains routines to read input 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 input from
19  * an ordinary stdio stream.  They further assume that reading begins
20  * at the start of the file; start_input may need work if the
21  * user interface has already read some data (e.g., to determine that
22  * the file is indeed PPM format).
23  */
24 
25 #include "cmyk.h"
26 #include "cdjpeg.h"             /* Common decls for cjpeg/djpeg applications */
27 
28 #ifdef PPM_SUPPORTED
29 
30 
31 /* Portions of this code are based on the PBMPLUS library, which is:
32 **
33 ** Copyright (C) 1988 by Jef Poskanzer.
34 **
35 ** Permission to use, copy, modify, and distribute this software and its
36 ** documentation for any purpose and without fee is hereby granted, provided
37 ** that the above copyright notice appear in all copies and that both that
38 ** copyright notice and this permission notice appear in supporting
39 ** documentation.  This software is provided "as is" without express or
40 ** implied warranty.
41 */
42 
43 
44 /* Macros to deal with unsigned chars as efficiently as compiler allows */
45 
46 typedef unsigned char U_CHAR;
47 #define UCH(x)  ((int)(x))
48 
49 
50 #define ReadOK(file, buffer, len) \
51   (JFREAD(file, buffer, len) == ((size_t)(len)))
52 
53 static int alpha_index[JPEG_NUMCS] = {
54   -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 3, 3, 0, 0, -1
55 };
56 
57 
58 /* Private version of data source object */
59 
60 typedef struct {
61   struct cjpeg_source_struct pub; /* public fields */
62 
63   /* Usually these two pointers point to the same place: */
64   U_CHAR *iobuffer;             /* fread's I/O buffer */
65   JSAMPROW pixrow;              /* compressor input buffer */
66   size_t buffer_width;          /* width of I/O buffer */
67   JSAMPLE *rescale;             /* => maxval-remapping array, or NULL */
68   unsigned int maxval;
69 } ppm_source_struct;
70 
71 typedef ppm_source_struct *ppm_source_ptr;
72 
73 
74 LOCAL(int)
pbm_getc(FILE * infile)75 pbm_getc(FILE *infile)
76 /* Read next char, skipping over any comments */
77 /* A comment/newline sequence is returned as a newline */
78 {
79   register int ch;
80 
81   ch = getc(infile);
82   if (ch == '#') {
83     do {
84       ch = getc(infile);
85     } while (ch != '\n' && ch != EOF);
86   }
87   return ch;
88 }
89 
90 
91 LOCAL(unsigned int)
read_pbm_integer(j_compress_ptr cinfo,FILE * infile,unsigned int maxval)92 read_pbm_integer(j_compress_ptr cinfo, FILE *infile, unsigned int maxval)
93 /* Read an unsigned decimal integer from the PPM file */
94 /* Swallows one trailing character after the integer */
95 /* Note that on a 16-bit-int machine, only values up to 64k can be read. */
96 /* This should not be a problem in practice. */
97 {
98   register int ch;
99   register unsigned int val;
100 
101   /* Skip any leading whitespace */
102   do {
103     ch = pbm_getc(infile);
104     if (ch == EOF)
105       ERREXIT(cinfo, JERR_INPUT_EOF);
106   } while (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r');
107 
108   if (ch < '0' || ch > '9')
109     ERREXIT(cinfo, JERR_PPM_NONNUMERIC);
110 
111   val = ch - '0';
112   while ((ch = pbm_getc(infile)) >= '0' && ch <= '9') {
113     val *= 10;
114     val += ch - '0';
115     if (val > maxval)
116       ERREXIT(cinfo, JERR_PPM_OUTOFRANGE);
117   }
118 
119   return val;
120 }
121 
122 
123 /*
124  * Read one row of pixels.
125  *
126  * We provide several different versions depending on input file format.
127  * In all cases, input is scaled to the size of JSAMPLE.
128  *
129  * A really fast path is provided for reading byte/sample raw files with
130  * maxval = MAXJSAMPLE, which is the normal case for 8-bit data.
131  */
132 
133 
134 METHODDEF(JDIMENSION)
get_text_gray_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)135 get_text_gray_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
136 /* This version is for reading text-format PGM files with any maxval */
137 {
138   ppm_source_ptr source = (ppm_source_ptr)sinfo;
139   FILE *infile = source->pub.input_file;
140   register JSAMPROW ptr;
141   register JSAMPLE *rescale = source->rescale;
142   JDIMENSION col;
143   unsigned int maxval = source->maxval;
144 
145   ptr = source->pub.buffer[0];
146   for (col = cinfo->image_width; col > 0; col--) {
147     *ptr++ = rescale[read_pbm_integer(cinfo, infile, maxval)];
148   }
149   return 1;
150 }
151 
152 
153 #define GRAY_RGB_READ_LOOP(read_op, alpha_set_op) { \
154   for (col = cinfo->image_width; col > 0; col--) { \
155     ptr[rindex] = ptr[gindex] = ptr[bindex] = read_op; \
156     alpha_set_op \
157     ptr += ps; \
158   } \
159 }
160 
161 METHODDEF(JDIMENSION)
get_text_gray_rgb_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)162 get_text_gray_rgb_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
163 /* This version is for reading text-format PGM files with any maxval and
164    converting to extended RGB */
165 {
166   ppm_source_ptr source = (ppm_source_ptr)sinfo;
167   FILE *infile = source->pub.input_file;
168   register JSAMPROW ptr;
169   register JSAMPLE *rescale = source->rescale;
170   JDIMENSION col;
171   unsigned int maxval = source->maxval;
172   register int rindex = rgb_red[cinfo->in_color_space];
173   register int gindex = rgb_green[cinfo->in_color_space];
174   register int bindex = rgb_blue[cinfo->in_color_space];
175   register int aindex = alpha_index[cinfo->in_color_space];
176   register int ps = rgb_pixelsize[cinfo->in_color_space];
177 
178   ptr = source->pub.buffer[0];
179   if (maxval == MAXJSAMPLE) {
180     if (aindex >= 0)
181       GRAY_RGB_READ_LOOP(read_pbm_integer(cinfo, infile, maxval),
182                          ptr[aindex] = 0xFF;)
183     else
184       GRAY_RGB_READ_LOOP(read_pbm_integer(cinfo, infile, maxval),)
185   } else {
186     if (aindex >= 0)
187       GRAY_RGB_READ_LOOP(rescale[read_pbm_integer(cinfo, infile, maxval)],
188                          ptr[aindex] = 0xFF;)
189     else
190       GRAY_RGB_READ_LOOP(rescale[read_pbm_integer(cinfo, infile, maxval)],)
191   }
192   return 1;
193 }
194 
195 
196 METHODDEF(JDIMENSION)
get_text_gray_cmyk_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)197 get_text_gray_cmyk_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
198 /* This version is for reading text-format PGM files with any maxval and
199    converting to CMYK */
200 {
201   ppm_source_ptr source = (ppm_source_ptr)sinfo;
202   FILE *infile = source->pub.input_file;
203   register JSAMPROW ptr;
204   register JSAMPLE *rescale = source->rescale;
205   JDIMENSION col;
206   unsigned int maxval = source->maxval;
207 
208   ptr = source->pub.buffer[0];
209   if (maxval == MAXJSAMPLE) {
210     for (col = cinfo->image_width; col > 0; col--) {
211       JSAMPLE gray = read_pbm_integer(cinfo, infile, maxval);
212       rgb_to_cmyk(gray, gray, gray, ptr, ptr + 1, ptr + 2, ptr + 3);
213       ptr += 4;
214     }
215   } else {
216     for (col = cinfo->image_width; col > 0; col--) {
217       JSAMPLE gray = rescale[read_pbm_integer(cinfo, infile, maxval)];
218       rgb_to_cmyk(gray, gray, gray, ptr, ptr + 1, ptr + 2, ptr + 3);
219       ptr += 4;
220     }
221   }
222   return 1;
223 }
224 
225 
226 #define RGB_READ_LOOP(read_op, alpha_set_op) { \
227   for (col = cinfo->image_width; col > 0; col--) { \
228     ptr[rindex] = read_op; \
229     ptr[gindex] = read_op; \
230     ptr[bindex] = read_op; \
231     alpha_set_op \
232     ptr += ps; \
233   } \
234 }
235 
236 METHODDEF(JDIMENSION)
get_text_rgb_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)237 get_text_rgb_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
238 /* This version is for reading text-format PPM files with any maxval */
239 {
240   ppm_source_ptr source = (ppm_source_ptr)sinfo;
241   FILE *infile = source->pub.input_file;
242   register JSAMPROW ptr;
243   register JSAMPLE *rescale = source->rescale;
244   JDIMENSION col;
245   unsigned int maxval = source->maxval;
246   register int rindex = rgb_red[cinfo->in_color_space];
247   register int gindex = rgb_green[cinfo->in_color_space];
248   register int bindex = rgb_blue[cinfo->in_color_space];
249   register int aindex = alpha_index[cinfo->in_color_space];
250   register int ps = rgb_pixelsize[cinfo->in_color_space];
251 
252   ptr = source->pub.buffer[0];
253   if (maxval == MAXJSAMPLE) {
254     if (aindex >= 0)
255       RGB_READ_LOOP(read_pbm_integer(cinfo, infile, maxval),
256                     ptr[aindex] = 0xFF;)
257     else
258       RGB_READ_LOOP(read_pbm_integer(cinfo, infile, maxval),)
259   } else {
260     if (aindex >= 0)
261       RGB_READ_LOOP(rescale[read_pbm_integer(cinfo, infile, maxval)],
262                     ptr[aindex] = 0xFF;)
263     else
264       RGB_READ_LOOP(rescale[read_pbm_integer(cinfo, infile, maxval)],)
265   }
266   return 1;
267 }
268 
269 
270 METHODDEF(JDIMENSION)
get_text_rgb_cmyk_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)271 get_text_rgb_cmyk_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
272 /* This version is for reading text-format PPM files with any maxval and
273    converting to CMYK */
274 {
275   ppm_source_ptr source = (ppm_source_ptr)sinfo;
276   FILE *infile = source->pub.input_file;
277   register JSAMPROW ptr;
278   register JSAMPLE *rescale = source->rescale;
279   JDIMENSION col;
280   unsigned int maxval = source->maxval;
281 
282   ptr = source->pub.buffer[0];
283   if (maxval == MAXJSAMPLE) {
284     for (col = cinfo->image_width; col > 0; col--) {
285       JSAMPLE r = read_pbm_integer(cinfo, infile, maxval);
286       JSAMPLE g = read_pbm_integer(cinfo, infile, maxval);
287       JSAMPLE b = read_pbm_integer(cinfo, infile, maxval);
288       rgb_to_cmyk(r, g, b, ptr, ptr + 1, ptr + 2, ptr + 3);
289       ptr += 4;
290     }
291   } else {
292     for (col = cinfo->image_width; col > 0; col--) {
293       JSAMPLE r = rescale[read_pbm_integer(cinfo, infile, maxval)];
294       JSAMPLE g = rescale[read_pbm_integer(cinfo, infile, maxval)];
295       JSAMPLE b = rescale[read_pbm_integer(cinfo, infile, maxval)];
296       rgb_to_cmyk(r, g, b, ptr, ptr + 1, ptr + 2, ptr + 3);
297       ptr += 4;
298     }
299   }
300   return 1;
301 }
302 
303 
304 METHODDEF(JDIMENSION)
get_scaled_gray_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)305 get_scaled_gray_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
306 /* This version is for reading raw-byte-format PGM files with any maxval */
307 {
308   ppm_source_ptr source = (ppm_source_ptr)sinfo;
309   register JSAMPROW ptr;
310   register U_CHAR *bufferptr;
311   register JSAMPLE *rescale = source->rescale;
312   JDIMENSION col;
313 
314   if (!ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
315     ERREXIT(cinfo, JERR_INPUT_EOF);
316   ptr = source->pub.buffer[0];
317   bufferptr = source->iobuffer;
318   for (col = cinfo->image_width; col > 0; col--) {
319     *ptr++ = rescale[UCH(*bufferptr++)];
320   }
321   return 1;
322 }
323 
324 
325 METHODDEF(JDIMENSION)
get_gray_rgb_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)326 get_gray_rgb_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
327 /* This version is for reading raw-byte-format PGM files with any maxval
328    and converting to extended RGB */
329 {
330   ppm_source_ptr source = (ppm_source_ptr)sinfo;
331   register JSAMPROW ptr;
332   register U_CHAR *bufferptr;
333   register JSAMPLE *rescale = source->rescale;
334   JDIMENSION col;
335   unsigned int maxval = source->maxval;
336   register int rindex = rgb_red[cinfo->in_color_space];
337   register int gindex = rgb_green[cinfo->in_color_space];
338   register int bindex = rgb_blue[cinfo->in_color_space];
339   register int aindex = alpha_index[cinfo->in_color_space];
340   register int ps = rgb_pixelsize[cinfo->in_color_space];
341 
342   if (!ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
343     ERREXIT(cinfo, JERR_INPUT_EOF);
344   ptr = source->pub.buffer[0];
345   bufferptr = source->iobuffer;
346   if (maxval == MAXJSAMPLE) {
347     if (aindex >= 0)
348       GRAY_RGB_READ_LOOP(*bufferptr++, ptr[aindex] = 0xFF;)
349     else
350       GRAY_RGB_READ_LOOP(*bufferptr++,)
351   } else {
352     if (aindex >= 0)
353       GRAY_RGB_READ_LOOP(rescale[UCH(*bufferptr++)], ptr[aindex] = 0xFF;)
354     else
355       GRAY_RGB_READ_LOOP(rescale[UCH(*bufferptr++)],)
356   }
357   return 1;
358 }
359 
360 
361 METHODDEF(JDIMENSION)
get_gray_cmyk_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)362 get_gray_cmyk_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
363 /* This version is for reading raw-byte-format PGM files with any maxval
364    and converting to CMYK */
365 {
366   ppm_source_ptr source = (ppm_source_ptr)sinfo;
367   register JSAMPROW ptr;
368   register U_CHAR *bufferptr;
369   register JSAMPLE *rescale = source->rescale;
370   JDIMENSION col;
371   unsigned int maxval = source->maxval;
372 
373   if (!ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
374     ERREXIT(cinfo, JERR_INPUT_EOF);
375   ptr = source->pub.buffer[0];
376   bufferptr = source->iobuffer;
377   if (maxval == MAXJSAMPLE) {
378     for (col = cinfo->image_width; col > 0; col--) {
379       JSAMPLE gray = *bufferptr++;
380       rgb_to_cmyk(gray, gray, gray, ptr, ptr + 1, ptr + 2, ptr + 3);
381       ptr += 4;
382     }
383   } else {
384     for (col = cinfo->image_width; col > 0; col--) {
385       JSAMPLE gray = rescale[UCH(*bufferptr++)];
386       rgb_to_cmyk(gray, gray, gray, ptr, ptr + 1, ptr + 2, ptr + 3);
387       ptr += 4;
388     }
389   }
390   return 1;
391 }
392 
393 
394 METHODDEF(JDIMENSION)
get_rgb_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)395 get_rgb_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
396 /* This version is for reading raw-byte-format PPM files with any maxval */
397 {
398   ppm_source_ptr source = (ppm_source_ptr)sinfo;
399   register JSAMPROW ptr;
400   register U_CHAR *bufferptr;
401   register JSAMPLE *rescale = source->rescale;
402   JDIMENSION col;
403   unsigned int maxval = source->maxval;
404   register int rindex = rgb_red[cinfo->in_color_space];
405   register int gindex = rgb_green[cinfo->in_color_space];
406   register int bindex = rgb_blue[cinfo->in_color_space];
407   register int aindex = alpha_index[cinfo->in_color_space];
408   register int ps = rgb_pixelsize[cinfo->in_color_space];
409 
410   if (!ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
411     ERREXIT(cinfo, JERR_INPUT_EOF);
412   ptr = source->pub.buffer[0];
413   bufferptr = source->iobuffer;
414   if (maxval == MAXJSAMPLE) {
415     if (aindex >= 0)
416       RGB_READ_LOOP(*bufferptr++, ptr[aindex] = 0xFF;)
417     else
418       RGB_READ_LOOP(*bufferptr++,)
419   } else {
420     if (aindex >= 0)
421       RGB_READ_LOOP(rescale[UCH(*bufferptr++)], ptr[aindex] = 0xFF;)
422     else
423       RGB_READ_LOOP(rescale[UCH(*bufferptr++)],)
424   }
425   return 1;
426 }
427 
428 
429 METHODDEF(JDIMENSION)
get_rgb_cmyk_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)430 get_rgb_cmyk_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
431 /* This version is for reading raw-byte-format PPM files with any maxval and
432    converting to CMYK */
433 {
434   ppm_source_ptr source = (ppm_source_ptr)sinfo;
435   register JSAMPROW ptr;
436   register U_CHAR *bufferptr;
437   register JSAMPLE *rescale = source->rescale;
438   JDIMENSION col;
439   unsigned int maxval = source->maxval;
440 
441   if (!ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
442     ERREXIT(cinfo, JERR_INPUT_EOF);
443   ptr = source->pub.buffer[0];
444   bufferptr = source->iobuffer;
445   if (maxval == MAXJSAMPLE) {
446     for (col = cinfo->image_width; col > 0; col--) {
447       JSAMPLE r = *bufferptr++;
448       JSAMPLE g = *bufferptr++;
449       JSAMPLE b = *bufferptr++;
450       rgb_to_cmyk(r, g, b, ptr, ptr + 1, ptr + 2, ptr + 3);
451       ptr += 4;
452     }
453   } else {
454     for (col = cinfo->image_width; col > 0; col--) {
455       JSAMPLE r = rescale[UCH(*bufferptr++)];
456       JSAMPLE g = rescale[UCH(*bufferptr++)];
457       JSAMPLE b = rescale[UCH(*bufferptr++)];
458       rgb_to_cmyk(r, g, b, ptr, ptr + 1, ptr + 2, ptr + 3);
459       ptr += 4;
460     }
461   }
462   return 1;
463 }
464 
465 
466 METHODDEF(JDIMENSION)
get_raw_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)467 get_raw_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
468 /* This version is for reading raw-byte-format files with maxval = MAXJSAMPLE.
469  * In this case we just read right into the JSAMPLE buffer!
470  * Note that same code works for PPM and PGM files.
471  */
472 {
473   ppm_source_ptr source = (ppm_source_ptr)sinfo;
474 
475   if (!ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
476     ERREXIT(cinfo, JERR_INPUT_EOF);
477   return 1;
478 }
479 
480 
481 METHODDEF(JDIMENSION)
get_word_gray_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)482 get_word_gray_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
483 /* This version is for reading raw-word-format PGM files with any maxval */
484 {
485   ppm_source_ptr source = (ppm_source_ptr)sinfo;
486   register JSAMPROW ptr;
487   register U_CHAR *bufferptr;
488   register JSAMPLE *rescale = source->rescale;
489   JDIMENSION col;
490   unsigned int maxval = source->maxval;
491 
492   if (!ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
493     ERREXIT(cinfo, JERR_INPUT_EOF);
494   ptr = source->pub.buffer[0];
495   bufferptr = source->iobuffer;
496   for (col = cinfo->image_width; col > 0; col--) {
497     register unsigned int temp;
498     temp  = UCH(*bufferptr++) << 8;
499     temp |= UCH(*bufferptr++);
500     if (temp > maxval)
501       ERREXIT(cinfo, JERR_PPM_OUTOFRANGE);
502     *ptr++ = rescale[temp];
503   }
504   return 1;
505 }
506 
507 
508 METHODDEF(JDIMENSION)
get_word_rgb_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)509 get_word_rgb_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
510 /* This version is for reading raw-word-format PPM files with any maxval */
511 {
512   ppm_source_ptr source = (ppm_source_ptr)sinfo;
513   register JSAMPROW ptr;
514   register U_CHAR *bufferptr;
515   register JSAMPLE *rescale = source->rescale;
516   JDIMENSION col;
517   unsigned int maxval = source->maxval;
518   register int rindex = rgb_red[cinfo->in_color_space];
519   register int gindex = rgb_green[cinfo->in_color_space];
520   register int bindex = rgb_blue[cinfo->in_color_space];
521   register int aindex = alpha_index[cinfo->in_color_space];
522   register int ps = rgb_pixelsize[cinfo->in_color_space];
523 
524   if (!ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
525     ERREXIT(cinfo, JERR_INPUT_EOF);
526   ptr = source->pub.buffer[0];
527   bufferptr = source->iobuffer;
528   for (col = cinfo->image_width; col > 0; col--) {
529     register unsigned int temp;
530     temp  = UCH(*bufferptr++) << 8;
531     temp |= UCH(*bufferptr++);
532     if (temp > maxval)
533       ERREXIT(cinfo, JERR_PPM_OUTOFRANGE);
534     ptr[rindex] = rescale[temp];
535     temp  = UCH(*bufferptr++) << 8;
536     temp |= UCH(*bufferptr++);
537     if (temp > maxval)
538       ERREXIT(cinfo, JERR_PPM_OUTOFRANGE);
539     ptr[gindex] = rescale[temp];
540     temp  = UCH(*bufferptr++) << 8;
541     temp |= UCH(*bufferptr++);
542     if (temp > maxval)
543       ERREXIT(cinfo, JERR_PPM_OUTOFRANGE);
544     ptr[bindex] = rescale[temp];
545     if (aindex >= 0)
546       ptr[aindex] = 0xFF;
547     ptr += ps;
548   }
549   return 1;
550 }
551 
552 
553 /*
554  * Read the file header; return image size and component count.
555  */
556 
557 METHODDEF(void)
start_input_ppm(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)558 start_input_ppm(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
559 {
560   ppm_source_ptr source = (ppm_source_ptr)sinfo;
561   int c;
562   unsigned int w, h, maxval;
563   boolean need_iobuffer, use_raw_buffer, need_rescale;
564 
565   if (getc(source->pub.input_file) != 'P')
566     ERREXIT(cinfo, JERR_PPM_NOT);
567 
568   c = getc(source->pub.input_file); /* subformat discriminator character */
569 
570   /* detect unsupported variants (ie, PBM) before trying to read header */
571   switch (c) {
572   case '2':                     /* it's a text-format PGM file */
573   case '3':                     /* it's a text-format PPM file */
574   case '5':                     /* it's a raw-format PGM file */
575   case '6':                     /* it's a raw-format PPM file */
576     break;
577   default:
578     ERREXIT(cinfo, JERR_PPM_NOT);
579     break;
580   }
581 
582   /* fetch the remaining header info */
583   w = read_pbm_integer(cinfo, source->pub.input_file, 65535);
584   h = read_pbm_integer(cinfo, source->pub.input_file, 65535);
585   maxval = read_pbm_integer(cinfo, source->pub.input_file, 65535);
586 
587   if (w <= 0 || h <= 0 || maxval <= 0) /* error check */
588     ERREXIT(cinfo, JERR_PPM_NOT);
589 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
590   if (sinfo->max_pixels && (unsigned long long)w * h > sinfo->max_pixels)
591     ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
592 #endif
593 
594   cinfo->data_precision = BITS_IN_JSAMPLE; /* we always rescale data to this */
595   cinfo->image_width = (JDIMENSION)w;
596   cinfo->image_height = (JDIMENSION)h;
597   source->maxval = maxval;
598 
599   /* initialize flags to most common settings */
600   need_iobuffer = TRUE;         /* do we need an I/O buffer? */
601   use_raw_buffer = FALSE;       /* do we map input buffer onto I/O buffer? */
602   need_rescale = TRUE;          /* do we need a rescale array? */
603 
604   switch (c) {
605   case '2':                     /* it's a text-format PGM file */
606     if (cinfo->in_color_space == JCS_UNKNOWN)
607       cinfo->in_color_space = JCS_GRAYSCALE;
608     TRACEMS2(cinfo, 1, JTRC_PGM_TEXT, w, h);
609     if (cinfo->in_color_space == JCS_GRAYSCALE)
610       source->pub.get_pixel_rows = get_text_gray_row;
611     else if (IsExtRGB(cinfo->in_color_space))
612       source->pub.get_pixel_rows = get_text_gray_rgb_row;
613     else if (cinfo->in_color_space == JCS_CMYK)
614       source->pub.get_pixel_rows = get_text_gray_cmyk_row;
615     else
616       ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
617     need_iobuffer = FALSE;
618     break;
619 
620   case '3':                     /* it's a text-format PPM file */
621     if (cinfo->in_color_space == JCS_UNKNOWN)
622       cinfo->in_color_space = JCS_EXT_RGB;
623     TRACEMS2(cinfo, 1, JTRC_PPM_TEXT, w, h);
624     if (IsExtRGB(cinfo->in_color_space))
625       source->pub.get_pixel_rows = get_text_rgb_row;
626     else if (cinfo->in_color_space == JCS_CMYK)
627       source->pub.get_pixel_rows = get_text_rgb_cmyk_row;
628     else
629       ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
630     need_iobuffer = FALSE;
631     break;
632 
633   case '5':                     /* it's a raw-format PGM file */
634     if (cinfo->in_color_space == JCS_UNKNOWN)
635       cinfo->in_color_space = JCS_GRAYSCALE;
636     TRACEMS2(cinfo, 1, JTRC_PGM, w, h);
637     if (maxval > 255) {
638       if (cinfo->in_color_space == JCS_GRAYSCALE)
639         source->pub.get_pixel_rows = get_word_gray_row;
640       else
641         ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
642     } else if (maxval == MAXJSAMPLE && sizeof(JSAMPLE) == sizeof(U_CHAR) &&
643                cinfo->in_color_space == JCS_GRAYSCALE) {
644       source->pub.get_pixel_rows = get_raw_row;
645       use_raw_buffer = TRUE;
646       need_rescale = FALSE;
647     } else {
648       if (cinfo->in_color_space == JCS_GRAYSCALE)
649         source->pub.get_pixel_rows = get_scaled_gray_row;
650       else if (IsExtRGB(cinfo->in_color_space))
651         source->pub.get_pixel_rows = get_gray_rgb_row;
652       else if (cinfo->in_color_space == JCS_CMYK)
653         source->pub.get_pixel_rows = get_gray_cmyk_row;
654       else
655         ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
656     }
657     break;
658 
659   case '6':                     /* it's a raw-format PPM file */
660     if (cinfo->in_color_space == JCS_UNKNOWN)
661       cinfo->in_color_space = JCS_EXT_RGB;
662     TRACEMS2(cinfo, 1, JTRC_PPM, w, h);
663     if (maxval > 255) {
664       if (IsExtRGB(cinfo->in_color_space))
665         source->pub.get_pixel_rows = get_word_rgb_row;
666       else
667         ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
668     } else if (maxval == MAXJSAMPLE && sizeof(JSAMPLE) == sizeof(U_CHAR) &&
669 #if RGB_RED == 0 && RGB_GREEN == 1 && RGB_BLUE == 2 && RGB_PIXELSIZE == 3
670                (cinfo->in_color_space == JCS_EXT_RGB ||
671                 cinfo->in_color_space == JCS_RGB)) {
672 #else
673                cinfo->in_color_space == JCS_EXT_RGB) {
674 #endif
675       source->pub.get_pixel_rows = get_raw_row;
676       use_raw_buffer = TRUE;
677       need_rescale = FALSE;
678     } else {
679       if (IsExtRGB(cinfo->in_color_space))
680         source->pub.get_pixel_rows = get_rgb_row;
681       else if (cinfo->in_color_space == JCS_CMYK)
682         source->pub.get_pixel_rows = get_rgb_cmyk_row;
683       else
684         ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
685     }
686     break;
687   }
688 
689   if (IsExtRGB(cinfo->in_color_space))
690     cinfo->input_components = rgb_pixelsize[cinfo->in_color_space];
691   else if (cinfo->in_color_space == JCS_GRAYSCALE)
692     cinfo->input_components = 1;
693   else if (cinfo->in_color_space == JCS_CMYK)
694     cinfo->input_components = 4;
695 
696   /* Allocate space for I/O buffer: 1 or 3 bytes or words/pixel. */
697   if (need_iobuffer) {
698     if (c == '6')
699       source->buffer_width = (size_t)w * 3 *
700         ((maxval <= 255) ? sizeof(U_CHAR) : (2 * sizeof(U_CHAR)));
701     else
702       source->buffer_width = (size_t)w *
703         ((maxval <= 255) ? sizeof(U_CHAR) : (2 * sizeof(U_CHAR)));
704     source->iobuffer = (U_CHAR *)
705       (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
706                                   source->buffer_width);
707   }
708 
709   /* Create compressor input buffer. */
710   if (use_raw_buffer) {
711     /* For unscaled raw-input case, we can just map it onto the I/O buffer. */
712     /* Synthesize a JSAMPARRAY pointer structure */
713     source->pixrow = (JSAMPROW)source->iobuffer;
714     source->pub.buffer = &source->pixrow;
715     source->pub.buffer_height = 1;
716   } else {
717     /* Need to translate anyway, so make a separate sample buffer. */
718     source->pub.buffer = (*cinfo->mem->alloc_sarray)
719       ((j_common_ptr)cinfo, JPOOL_IMAGE,
720        (JDIMENSION)w * cinfo->input_components, (JDIMENSION)1);
721     source->pub.buffer_height = 1;
722   }
723 
724   /* Compute the rescaling array if required. */
725   if (need_rescale) {
726     long val, half_maxval;
727 
728     /* On 16-bit-int machines we have to be careful of maxval = 65535 */
729     source->rescale = (JSAMPLE *)
730       (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
731                                   (size_t)(((long)MAX(maxval, 255) + 1L) *
732                                            sizeof(JSAMPLE)));
733     MEMZERO(source->rescale, (size_t)(((long)MAX(maxval, 255) + 1L) *
734                                       sizeof(JSAMPLE)));
735     half_maxval = maxval / 2;
736     for (val = 0; val <= (long)maxval; val++) {
737       /* The multiplication here must be done in 32 bits to avoid overflow */
738       source->rescale[val] = (JSAMPLE)((val * MAXJSAMPLE + half_maxval) /
739                                         maxval);
740     }
741   }
742 }
743 
744 
745 /*
746  * Finish up at the end of the file.
747  */
748 
749 METHODDEF(void)
750 finish_input_ppm(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
751 {
752   /* no work */
753 }
754 
755 
756 /*
757  * The module selection routine for PPM format input.
758  */
759 
760 GLOBAL(cjpeg_source_ptr)
761 jinit_read_ppm(j_compress_ptr cinfo)
762 {
763   ppm_source_ptr source;
764 
765   /* Create module interface object */
766   source = (ppm_source_ptr)
767     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
768                                 sizeof(ppm_source_struct));
769   /* Fill in method ptrs, except get_pixel_rows which start_input sets */
770   source->pub.start_input = start_input_ppm;
771   source->pub.finish_input = finish_input_ppm;
772 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
773   source->pub.max_pixels = 0;
774 #endif
775 
776   return (cjpeg_source_ptr)source;
777 }
778 
779 #endif /* PPM_SUPPORTED */
780