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comparison mupdf-source/thirdparty/libjpeg/wrjpgcom.c @ 2:b50eed0cc0ef upstream

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ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4. The directory name has changed: no version number in the expanded directory now.
author Franz Glasner <fzglas.hg@dom66.de>
date Mon, 15 Sep 2025 11:43:07 +0200
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1:1d09e1dec1d9 2:b50eed0cc0ef
1 /*
2 * wrjpgcom.c
3 *
4 * Copyright (C) 1994-1997, Thomas G. Lane.
5 * Modified 2015-2017 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 a very simple stand-alone application that inserts
10 * user-supplied text as a COM (comment) marker in a JFIF file.
11 * This may be useful as an example of the minimum logic needed to parse
12 * JPEG markers.
13 */
14
15 #define JPEG_CJPEG_DJPEG /* to get the command-line config symbols */
16 #include "jinclude.h" /* get auto-config symbols, <stdio.h> */
17
18 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc() */
19 extern void * malloc ();
20 #endif
21 #include <ctype.h> /* to declare isupper(), tolower() */
22 #ifdef USE_SETMODE
23 #include <fcntl.h> /* to declare setmode()'s parameter macros */
24 /* If you have setmode() but not <io.h>, just delete this line: */
25 #include <io.h> /* to declare setmode() */
26 #endif
27
28 #ifdef USE_CCOMMAND /* command-line reader for Macintosh */
29 #ifdef __MWERKS__
30 #include <SIOUX.h> /* Metrowerks needs this */
31 #include <console.h> /* ... and this */
32 #endif
33 #ifdef THINK_C
34 #include <console.h> /* Think declares it here */
35 #endif
36 #endif
37
38 #ifdef DONT_USE_B_MODE /* define mode parameters for fopen() */
39 #define READ_BINARY "r"
40 #define WRITE_BINARY "w"
41 #else
42 #ifdef VMS /* VMS is very nonstandard */
43 #define READ_BINARY "rb", "ctx=stm"
44 #define WRITE_BINARY "wb", "ctx=stm"
45 #else /* standard ANSI-compliant case */
46 #define READ_BINARY "rb"
47 #define WRITE_BINARY "wb"
48 #endif
49 #endif
50
51 #ifndef EXIT_FAILURE /* define exit() codes if not provided */
52 #define EXIT_FAILURE 1
53 #endif
54 #ifndef EXIT_SUCCESS
55 #ifdef VMS
56 #define EXIT_SUCCESS 1 /* VMS is very nonstandard */
57 #else
58 #define EXIT_SUCCESS 0
59 #endif
60 #endif
61
62 /* Reduce this value if your malloc() can't allocate blocks up to 64K.
63 * On DOS, compiling in large model is usually a better solution.
64 */
65
66 #ifndef MAX_COM_LENGTH
67 #define MAX_COM_LENGTH 65000L /* must be <= 65533 in any case */
68 #endif
69
70
71 /*
72 * These macros are used to read the input file and write the output file.
73 * To reuse this code in another application, you might need to change these.
74 */
75
76 static FILE * infile; /* input JPEG file */
77
78 /* Return next input byte, or EOF if no more */
79 #define NEXTBYTE() getc(infile)
80
81 static FILE * outfile; /* output JPEG file */
82
83 /* Emit an output byte */
84 #define PUTBYTE(x) putc((x), outfile)
85
86
87 /* Error exit handler */
88 #define ERREXIT(msg) (fprintf(stderr, "%s\n", msg), exit(EXIT_FAILURE))
89
90
91 /* Read one byte, testing for EOF */
92 static int
93 read_1_byte (void)
94 {
95 int c;
96
97 c = NEXTBYTE();
98 if (c == EOF)
99 ERREXIT("Premature EOF in JPEG file");
100 return c;
101 }
102
103 /* Read 2 bytes, convert to unsigned int */
104 /* All 2-byte quantities in JPEG markers are MSB first */
105 static unsigned int
106 read_2_bytes (void)
107 {
108 int c1, c2;
109
110 c1 = NEXTBYTE();
111 if (c1 == EOF)
112 ERREXIT("Premature EOF in JPEG file");
113 c2 = NEXTBYTE();
114 if (c2 == EOF)
115 ERREXIT("Premature EOF in JPEG file");
116 return (((unsigned int) c1) << 8) + ((unsigned int) c2);
117 }
118
119
120 /* Routines to write data to output file */
121
122 static void
123 write_1_byte (int c)
124 {
125 PUTBYTE(c);
126 }
127
128 static void
129 write_2_bytes (unsigned int val)
130 {
131 PUTBYTE((val >> 8) & 0xFF);
132 PUTBYTE(val & 0xFF);
133 }
134
135 static void
136 write_marker (int marker)
137 {
138 PUTBYTE(0xFF);
139 PUTBYTE(marker);
140 }
141
142 static void
143 copy_rest_of_file (void)
144 {
145 int c;
146
147 while ((c = NEXTBYTE()) != EOF)
148 PUTBYTE(c);
149 }
150
151
152 /*
153 * JPEG markers consist of one or more 0xFF bytes, followed by a marker
154 * code byte (which is not an FF). Here are the marker codes of interest
155 * in this program. (See jdmarker.c for a more complete list.)
156 */
157
158 #define M_SOF0 0xC0 /* Start Of Frame N */
159 #define M_SOF1 0xC1 /* N indicates which compression process */
160 #define M_SOF2 0xC2 /* Only SOF0-SOF2 are now in common use */
161 #define M_SOF3 0xC3
162 #define M_SOF5 0xC5 /* NB: codes C4 and CC are NOT SOF markers */
163 #define M_SOF6 0xC6
164 #define M_SOF7 0xC7
165 #define M_SOF9 0xC9
166 #define M_SOF10 0xCA
167 #define M_SOF11 0xCB
168 #define M_SOF13 0xCD
169 #define M_SOF14 0xCE
170 #define M_SOF15 0xCF
171 #define M_SOI 0xD8 /* Start Of Image (beginning of datastream) */
172 #define M_EOI 0xD9 /* End Of Image (end of datastream) */
173 #define M_SOS 0xDA /* Start Of Scan (begins compressed data) */
174 #define M_COM 0xFE /* COMment */
175
176
177 /*
178 * Find the next JPEG marker and return its marker code.
179 * We expect at least one FF byte, possibly more if the compressor used FFs
180 * to pad the file. (Padding FFs will NOT be replicated in the output file.)
181 * There could also be non-FF garbage between markers. The treatment of such
182 * garbage is unspecified; we choose to skip over it but emit a warning msg.
183 * NB: this routine must not be used after seeing SOS marker, since it will
184 * not deal correctly with FF/00 sequences in the compressed image data...
185 */
186
187 static int
188 next_marker (void)
189 {
190 int c;
191 int discarded_bytes = 0;
192
193 /* Find 0xFF byte; count and skip any non-FFs. */
194 c = read_1_byte();
195 while (c != 0xFF) {
196 discarded_bytes++;
197 c = read_1_byte();
198 }
199 /* Get marker code byte, swallowing any duplicate FF bytes. Extra FFs
200 * are legal as pad bytes, so don't count them in discarded_bytes.
201 */
202 do {
203 c = read_1_byte();
204 } while (c == 0xFF);
205
206 if (discarded_bytes != 0) {
207 fprintf(stderr, "Warning: garbage data found in JPEG file\n");
208 }
209
210 return c;
211 }
212
213
214 /*
215 * Read the initial marker, which should be SOI.
216 * For a JFIF file, the first two bytes of the file should be literally
217 * 0xFF M_SOI. To be more general, we could use next_marker, but if the
218 * input file weren't actually JPEG at all, next_marker might read the whole
219 * file and then return a misleading error message...
220 */
221
222 static int
223 first_marker (void)
224 {
225 int c1, c2;
226
227 c1 = NEXTBYTE();
228 c2 = NEXTBYTE();
229 if (c1 != 0xFF || c2 != M_SOI)
230 ERREXIT("Not a JPEG file");
231 return c2;
232 }
233
234
235 /*
236 * Most types of marker are followed by a variable-length parameter segment.
237 * This routine skips over the parameters for any marker we don't otherwise
238 * want to process.
239 * Note that we MUST skip the parameter segment explicitly in order not to
240 * be fooled by 0xFF bytes that might appear within the parameter segment;
241 * such bytes do NOT introduce new markers.
242 */
243
244 static void
245 copy_variable (void)
246 /* Copy an unknown or uninteresting variable-length marker */
247 {
248 unsigned int length;
249
250 /* Get the marker parameter length count */
251 length = read_2_bytes();
252 write_2_bytes(length);
253 /* Length includes itself, so must be at least 2 */
254 if (length < 2)
255 ERREXIT("Erroneous JPEG marker length");
256 length -= 2;
257 /* Copy the remaining bytes */
258 while (length > 0) {
259 write_1_byte(read_1_byte());
260 length--;
261 }
262 }
263
264 static void
265 skip_variable (void)
266 /* Skip over an unknown or uninteresting variable-length marker */
267 {
268 unsigned int length;
269
270 /* Get the marker parameter length count */
271 length = read_2_bytes();
272 /* Length includes itself, so must be at least 2 */
273 if (length < 2)
274 ERREXIT("Erroneous JPEG marker length");
275 length -= 2;
276 /* Skip over the remaining bytes */
277 while (length > 0) {
278 (void) read_1_byte();
279 length--;
280 }
281 }
282
283
284 /*
285 * Parse the marker stream until SOFn or EOI is seen;
286 * copy data to output, but discard COM markers unless keep_COM is true.
287 */
288
289 static int
290 scan_JPEG_header (int keep_COM)
291 {
292 int marker;
293
294 /* Expect SOI at start of file */
295 if (first_marker() != M_SOI)
296 ERREXIT("Expected SOI marker first");
297 write_marker(M_SOI);
298
299 /* Scan miscellaneous markers until we reach SOFn. */
300 for (;;) {
301 marker = next_marker();
302 switch (marker) {
303 /* Note that marker codes 0xC4, 0xC8, 0xCC are not, and must not be,
304 * treated as SOFn. C4 in particular is actually DHT.
305 */
306 case M_SOF0: /* Baseline */
307 case M_SOF1: /* Extended sequential, Huffman */
308 case M_SOF2: /* Progressive, Huffman */
309 case M_SOF3: /* Lossless, Huffman */
310 case M_SOF5: /* Differential sequential, Huffman */
311 case M_SOF6: /* Differential progressive, Huffman */
312 case M_SOF7: /* Differential lossless, Huffman */
313 case M_SOF9: /* Extended sequential, arithmetic */
314 case M_SOF10: /* Progressive, arithmetic */
315 case M_SOF11: /* Lossless, arithmetic */
316 case M_SOF13: /* Differential sequential, arithmetic */
317 case M_SOF14: /* Differential progressive, arithmetic */
318 case M_SOF15: /* Differential lossless, arithmetic */
319 return marker;
320
321 case M_SOS: /* should not see compressed data before SOF */
322 ERREXIT("SOS without prior SOFn");
323 break;
324
325 case M_EOI: /* in case it's a tables-only JPEG stream */
326 return marker;
327
328 case M_COM: /* Existing COM: conditionally discard */
329 if (keep_COM) {
330 write_marker(marker);
331 copy_variable();
332 } else {
333 skip_variable();
334 }
335 break;
336
337 default: /* Anything else just gets copied */
338 write_marker(marker);
339 copy_variable(); /* we assume it has a parameter count... */
340 break;
341 }
342 } /* end loop */
343 }
344
345
346 /* Command line parsing code */
347
348 static const char * progname; /* program name for error messages */
349
350
351 static void
352 usage (void)
353 /* complain about bad command line */
354 {
355 fprintf(stderr, "wrjpgcom inserts a textual comment in a JPEG file.\n");
356 fprintf(stderr, "You can add to or replace any existing comment(s).\n");
357
358 fprintf(stderr, "Usage: %s [switches] ", progname);
359 #ifdef TWO_FILE_COMMANDLINE
360 fprintf(stderr, "inputfile outputfile\n");
361 #else
362 fprintf(stderr, "[inputfile]\n");
363 #endif
364
365 fprintf(stderr, "Switches (names may be abbreviated):\n");
366 fprintf(stderr, " -replace Delete any existing comments\n");
367 fprintf(stderr, " -comment \"text\" Insert comment with given text\n");
368 fprintf(stderr, " -cfile name Read comment from named file\n");
369 fprintf(stderr, "Notice that you must put quotes around the comment text\n");
370 fprintf(stderr, "when you use -comment.\n");
371 fprintf(stderr, "If you do not give either -comment or -cfile on the command line,\n");
372 fprintf(stderr, "then the comment text is read from standard input.\n");
373 fprintf(stderr, "It can be multiple lines, up to %u characters total.\n",
374 (unsigned int) MAX_COM_LENGTH);
375 #ifndef TWO_FILE_COMMANDLINE
376 fprintf(stderr, "You must specify an input JPEG file name when supplying\n");
377 fprintf(stderr, "comment text from standard input.\n");
378 #endif
379
380 exit(EXIT_FAILURE);
381 }
382
383
384 static int
385 keymatch (char * arg, const char * keyword, int minchars)
386 /* Case-insensitive matching of (possibly abbreviated) keyword switches. */
387 /* keyword is the constant keyword (must be lower case already), */
388 /* minchars is length of minimum legal abbreviation. */
389 {
390 register int ca, ck;
391 register int nmatched = 0;
392
393 while ((ca = *arg++) != '\0') {
394 if ((ck = *keyword++) == '\0')
395 return 0; /* arg longer than keyword, no good */
396 if (isupper(ca)) /* force arg to lcase (assume ck is already) */
397 ca = tolower(ca);
398 if (ca != ck)
399 return 0; /* no good */
400 nmatched++; /* count matched characters */
401 }
402 /* reached end of argument; fail if it's too short for unique abbrev */
403 if (nmatched < minchars)
404 return 0;
405 return 1; /* A-OK */
406 }
407
408
409 /*
410 * The main program.
411 */
412
413 int
414 main (int argc, char **argv)
415 {
416 int argn;
417 char * arg;
418 int keep_COM = 1;
419 char * comment_arg = NULL;
420 FILE * comment_file = NULL;
421 unsigned int comment_length = 0;
422 int marker;
423
424 /* On Mac, fetch a command line. */
425 #ifdef USE_CCOMMAND
426 argc = ccommand(&argv);
427 #endif
428
429 progname = argv[0];
430 if (progname == NULL || progname[0] == 0)
431 progname = "wrjpgcom"; /* in case C library doesn't provide it */
432
433 /* Parse switches, if any */
434 for (argn = 1; argn < argc; argn++) {
435 arg = argv[argn];
436 if (arg[0] != '-')
437 break; /* not switch, must be file name */
438 arg++; /* advance over '-' */
439 if (keymatch(arg, "replace", 1)) {
440 keep_COM = 0;
441 } else if (keymatch(arg, "cfile", 2)) {
442 if (++argn >= argc) usage();
443 if ((comment_file = fopen(argv[argn], "r")) == NULL) {
444 fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
445 exit(EXIT_FAILURE);
446 }
447 } else if (keymatch(arg, "comment", 1)) {
448 if (++argn >= argc) usage();
449 comment_arg = argv[argn];
450 /* If the comment text starts with '"', then we are probably running
451 * under MS-DOG and must parse out the quoted string ourselves. Sigh.
452 */
453 if (comment_arg[0] == '"') {
454 comment_arg = (char *) malloc((size_t) MAX_COM_LENGTH);
455 if (comment_arg == NULL)
456 ERREXIT("Insufficient memory");
457 if (strlen(argv[argn]+1) >= (size_t) MAX_COM_LENGTH) {
458 fprintf(stderr, "Comment text may not exceed %u bytes\n",
459 (unsigned int) MAX_COM_LENGTH);
460 exit(EXIT_FAILURE);
461 }
462 strcpy(comment_arg, argv[argn]+1);
463 for (;;) {
464 comment_length = (unsigned int) strlen(comment_arg);
465 if (comment_length > 0 && comment_arg[comment_length-1] == '"') {
466 comment_arg[comment_length-1] = '\0'; /* zap terminating quote */
467 break;
468 }
469 if (++argn >= argc)
470 ERREXIT("Missing ending quote mark");
471 if (strlen(comment_arg) + 1 + strlen(argv[argn]) >=
472 (size_t) MAX_COM_LENGTH) {
473 fprintf(stderr, "Comment text may not exceed %u bytes\n",
474 (unsigned int) MAX_COM_LENGTH);
475 exit(EXIT_FAILURE);
476 }
477 strcat(comment_arg, " ");
478 strcat(comment_arg, argv[argn]);
479 }
480 } else if (strlen(comment_arg) >= (size_t) MAX_COM_LENGTH) {
481 fprintf(stderr, "Comment text may not exceed %u bytes\n",
482 (unsigned int) MAX_COM_LENGTH);
483 exit(EXIT_FAILURE);
484 }
485 comment_length = (unsigned int) strlen(comment_arg);
486 } else
487 usage();
488 }
489
490 /* Cannot use both -comment and -cfile. */
491 if (comment_arg != NULL && comment_file != NULL)
492 usage();
493 /* If there is neither -comment nor -cfile, we will read the comment text
494 * from stdin; in this case there MUST be an input JPEG file name.
495 */
496 if (comment_arg == NULL && comment_file == NULL && argn >= argc)
497 usage();
498
499 /* Open the input file. */
500 if (argn < argc) {
501 if ((infile = fopen(argv[argn], READ_BINARY)) == NULL) {
502 fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
503 exit(EXIT_FAILURE);
504 }
505 } else {
506 /* default input file is stdin */
507 #ifdef USE_SETMODE /* need to hack file mode? */
508 setmode(fileno(stdin), O_BINARY);
509 #endif
510 #ifdef USE_FDOPEN /* need to re-open in binary mode? */
511 if ((infile = fdopen(fileno(stdin), READ_BINARY)) == NULL) {
512 fprintf(stderr, "%s: can't open stdin\n", progname);
513 exit(EXIT_FAILURE);
514 }
515 #else
516 infile = stdin;
517 #endif
518 }
519
520 /* Open the output file. */
521 #ifdef TWO_FILE_COMMANDLINE
522 /* Must have explicit output file name */
523 if (argn != argc-2) {
524 fprintf(stderr, "%s: must name one input and one output file\n",
525 progname);
526 usage();
527 }
528 if ((outfile = fopen(argv[argn+1], WRITE_BINARY)) == NULL) {
529 fprintf(stderr, "%s: can't open %s\n", progname, argv[argn+1]);
530 exit(EXIT_FAILURE);
531 }
532 #else
533 /* Unix style: expect zero or one file name */
534 if (argn < argc-1) {
535 fprintf(stderr, "%s: only one input file\n", progname);
536 usage();
537 }
538 /* default output file is stdout */
539 #ifdef USE_SETMODE /* need to hack file mode? */
540 setmode(fileno(stdout), O_BINARY);
541 #endif
542 #ifdef USE_FDOPEN /* need to re-open in binary mode? */
543 if ((outfile = fdopen(fileno(stdout), WRITE_BINARY)) == NULL) {
544 fprintf(stderr, "%s: can't open stdout\n", progname);
545 exit(EXIT_FAILURE);
546 }
547 #else
548 outfile = stdout;
549 #endif
550 #endif /* TWO_FILE_COMMANDLINE */
551
552 /* Collect comment text from comment_file or stdin, if necessary */
553 if (comment_arg == NULL) {
554 FILE * src_file;
555 int c;
556
557 comment_arg = (char *) malloc((size_t) MAX_COM_LENGTH);
558 if (comment_arg == NULL)
559 ERREXIT("Insufficient memory");
560 comment_length = 0;
561 src_file = (comment_file != NULL ? comment_file : stdin);
562 while ((c = getc(src_file)) != EOF) {
563 if (comment_length >= (unsigned int) MAX_COM_LENGTH) {
564 fprintf(stderr, "Comment text may not exceed %u bytes\n",
565 (unsigned int) MAX_COM_LENGTH);
566 exit(EXIT_FAILURE);
567 }
568 comment_arg[comment_length++] = (char) c;
569 }
570 if (comment_file != NULL)
571 fclose(comment_file);
572 }
573
574 /* Copy JPEG headers until SOFn marker;
575 * we will insert the new comment marker just before SOFn.
576 * This (a) causes the new comment to appear after, rather than before,
577 * existing comments; and (b) ensures that comments come after any JFIF
578 * or JFXX markers, as required by the JFIF specification.
579 */
580 marker = scan_JPEG_header(keep_COM);
581 /* Insert the new COM marker, but only if nonempty text has been supplied */
582 if (comment_length > 0) {
583 write_marker(M_COM);
584 write_2_bytes(comment_length + 2);
585 while (comment_length > 0) {
586 write_1_byte(*comment_arg++);
587 comment_length--;
588 }
589 }
590 /* Duplicate the remainder of the source file.
591 * Note that any COM markers occuring after SOF will not be touched.
592 */
593 write_marker(marker);
594 copy_rest_of_file();
595
596 /* All done. */
597 exit(EXIT_SUCCESS);
598 return 0; /* suppress no-return-value warnings */
599 }