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1 /*
2  * djpeg.c
3  *
4  * This file was part of the Independent JPEG Group's software:
5  * Copyright (C) 1991-1997, Thomas G. Lane.
6  * Modified 2013-2019 by Guido Vollbeding.
7  * libjpeg-turbo Modifications:
8  * Copyright (C) 2010-2011, 2013-2017, 2019-2020, 2022, D. R. Commander.
9  * Copyright (C) 2015, Google, Inc.
10  * For conditions of distribution and use, see the accompanying README.ijg
11  * file.
12  *
13  * This file contains a command-line user interface for the JPEG decompressor.
14  * It should work on any system with Unix- or MS-DOS-style command lines.
15  *
16  * Two different command line styles are permitted, depending on the
17  * compile-time switch TWO_FILE_COMMANDLINE:
18  *      djpeg [options]  inputfile outputfile
19  *      djpeg [options]  [inputfile]
20  * In the second style, output is always to standard output, which you'd
21  * normally redirect to a file or pipe to some other program.  Input is
22  * either from a named file or from standard input (typically redirected).
23  * The second style is convenient on Unix but is unhelpful on systems that
24  * don't support pipes.  Also, you MUST use the first style if your system
25  * doesn't do binary I/O to stdin/stdout.
26  * To simplify script writing, the "-outfile" switch is provided.  The syntax
27  *      djpeg [options]  -outfile outputfile  inputfile
28  * works regardless of which command line style is used.
29  */
30 
31 #ifdef _MSC_VER
32 #define _CRT_SECURE_NO_DEPRECATE
33 #endif
34 
35 #include "cdjpeg.h"             /* Common decls for cjpeg/djpeg applications */
36 #include "jversion.h"           /* for version message */
37 #include "jconfigint.h"
38 
39 #include <ctype.h>              /* to declare isprint() */
40 
41 
42 /* Create the add-on message string table. */
43 
44 #define JMESSAGE(code, string)  string,
45 
46 static const char * const cdjpeg_message_table[] = {
47 #include "cderror.h"
48   NULL
49 };
50 
51 
52 /*
53  * This list defines the known output image formats
54  * (not all of which need be supported by a given version).
55  * You can change the default output format by defining DEFAULT_FMT;
56  * indeed, you had better do so if you undefine PPM_SUPPORTED.
57  */
58 
59 typedef enum {
60   FMT_BMP,                      /* BMP format (Windows flavor) */
61   FMT_GIF,                      /* GIF format (LZW-compressed) */
62   FMT_GIF0,                     /* GIF format (uncompressed) */
63   FMT_OS2,                      /* BMP format (OS/2 flavor) */
64   FMT_PPM,                      /* PPM/PGM (PBMPLUS formats) */
65   FMT_TARGA,                    /* Targa format */
66   FMT_TIFF                      /* TIFF format */
67 } IMAGE_FORMATS;
68 
69 #ifndef DEFAULT_FMT             /* so can override from CFLAGS in Makefile */
70 #define DEFAULT_FMT     FMT_PPM
71 #endif
72 
73 static IMAGE_FORMATS requested_fmt;
74 
75 
76 /*
77  * Argument-parsing code.
78  * The switch parser is designed to be useful with DOS-style command line
79  * syntax, ie, intermixed switches and file names, where only the switches
80  * to the left of a given file name affect processing of that file.
81  * The main program in this file doesn't actually use this capability...
82  */
83 
84 
85 static const char *progname;    /* program name for error messages */
86 static char *icc_filename;      /* for -icc switch */
87 JDIMENSION max_scans;           /* for -maxscans switch */
88 static char *outfilename;       /* for -outfile switch */
89 boolean memsrc;                 /* for -memsrc switch */
90 boolean report;                 /* for -report switch */
91 boolean skip, crop;
92 JDIMENSION skip_start, skip_end;
93 JDIMENSION crop_x, crop_y, crop_width, crop_height;
94 boolean strict;                 /* for -strict switch */
95 #define INPUT_BUF_SIZE  4096
96 
97 
98 LOCAL(void)
usage(void)99 usage(void)
100 /* complain about bad command line */
101 {
102   fprintf(stderr, "usage: %s [switches] ", progname);
103 #ifdef TWO_FILE_COMMANDLINE
104   fprintf(stderr, "inputfile outputfile\n");
105 #else
106   fprintf(stderr, "[inputfile]\n");
107 #endif
108 
109   fprintf(stderr, "Switches (names may be abbreviated):\n");
110   fprintf(stderr, "  -colors N      Reduce image to no more than N colors\n");
111   fprintf(stderr, "  -fast          Fast, low-quality processing\n");
112   fprintf(stderr, "  -grayscale     Force grayscale output\n");
113   fprintf(stderr, "  -rgb           Force RGB output\n");
114   fprintf(stderr, "  -rgb565        Force RGB565 output\n");
115 #ifdef IDCT_SCALING_SUPPORTED
116   fprintf(stderr, "  -scale M/N     Scale output image by fraction M/N, eg, 1/8\n");
117 #endif
118 #ifdef BMP_SUPPORTED
119   fprintf(stderr, "  -bmp           Select BMP output format (Windows style)%s\n",
120           (DEFAULT_FMT == FMT_BMP ? " (default)" : ""));
121 #endif
122 #ifdef GIF_SUPPORTED
123   fprintf(stderr, "  -gif           Select GIF output format (LZW-compressed)%s\n",
124           (DEFAULT_FMT == FMT_GIF ? " (default)" : ""));
125   fprintf(stderr, "  -gif0          Select GIF output format (uncompressed)%s\n",
126           (DEFAULT_FMT == FMT_GIF0 ? " (default)" : ""));
127 #endif
128 #ifdef BMP_SUPPORTED
129   fprintf(stderr, "  -os2           Select BMP output format (OS/2 style)%s\n",
130           (DEFAULT_FMT == FMT_OS2 ? " (default)" : ""));
131 #endif
132 #ifdef PPM_SUPPORTED
133   fprintf(stderr, "  -pnm           Select PBMPLUS (PPM/PGM) output format%s\n",
134           (DEFAULT_FMT == FMT_PPM ? " (default)" : ""));
135 #endif
136 #ifdef TARGA_SUPPORTED
137   fprintf(stderr, "  -targa         Select Targa output format%s\n",
138           (DEFAULT_FMT == FMT_TARGA ? " (default)" : ""));
139 #endif
140   fprintf(stderr, "Switches for advanced users:\n");
141 #ifdef DCT_ISLOW_SUPPORTED
142   fprintf(stderr, "  -dct int       Use accurate integer DCT method%s\n",
143           (JDCT_DEFAULT == JDCT_ISLOW ? " (default)" : ""));
144 #endif
145 #ifdef DCT_IFAST_SUPPORTED
146   fprintf(stderr, "  -dct fast      Use less accurate integer DCT method [legacy feature]%s\n",
147           (JDCT_DEFAULT == JDCT_IFAST ? " (default)" : ""));
148 #endif
149 #ifdef DCT_FLOAT_SUPPORTED
150   fprintf(stderr, "  -dct float     Use floating-point DCT method [legacy feature]%s\n",
151           (JDCT_DEFAULT == JDCT_FLOAT ? " (default)" : ""));
152 #endif
153   fprintf(stderr, "  -dither fs     Use F-S dithering (default)\n");
154   fprintf(stderr, "  -dither none   Don't use dithering in quantization\n");
155   fprintf(stderr, "  -dither ordered  Use ordered dither (medium speed, quality)\n");
156   fprintf(stderr, "  -icc FILE      Extract ICC profile to FILE\n");
157 #ifdef QUANT_2PASS_SUPPORTED
158   fprintf(stderr, "  -map FILE      Map to colors used in named image file\n");
159 #endif
160   fprintf(stderr, "  -nosmooth      Don't use high-quality upsampling\n");
161 #ifdef QUANT_1PASS_SUPPORTED
162   fprintf(stderr, "  -onepass       Use 1-pass quantization (fast, low quality)\n");
163 #endif
164   fprintf(stderr, "  -maxmemory N   Maximum memory to use (in kbytes)\n");
165   fprintf(stderr, "  -maxscans N    Maximum number of scans to allow in input file\n");
166   fprintf(stderr, "  -outfile name  Specify name for output file\n");
167 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
168   fprintf(stderr, "  -memsrc        Load input file into memory before decompressing\n");
169 #endif
170   fprintf(stderr, "  -report        Report decompression progress\n");
171   fprintf(stderr, "  -skip Y0,Y1    Decompress all rows except those between Y0 and Y1 (inclusive)\n");
172   fprintf(stderr, "  -crop WxH+X+Y  Decompress only a rectangular subregion of the image\n");
173   fprintf(stderr, "                 [requires PBMPLUS (PPM/PGM), GIF, or Targa output format]\n");
174   fprintf(stderr, "  -strict        Treat all warnings as fatal\n");
175   fprintf(stderr, "  -verbose  or  -debug   Emit debug output\n");
176   fprintf(stderr, "  -version       Print version information and exit\n");
177   exit(EXIT_FAILURE);
178 }
179 
180 
181 LOCAL(int)
parse_switches(j_decompress_ptr cinfo,int argc,char ** argv,int last_file_arg_seen,boolean for_real)182 parse_switches(j_decompress_ptr cinfo, int argc, char **argv,
183                int last_file_arg_seen, boolean for_real)
184 /* Parse optional switches.
185  * Returns argv[] index of first file-name argument (== argc if none).
186  * Any file names with indexes <= last_file_arg_seen are ignored;
187  * they have presumably been processed in a previous iteration.
188  * (Pass 0 for last_file_arg_seen on the first or only iteration.)
189  * for_real is FALSE on the first (dummy) pass; we may skip any expensive
190  * processing.
191  */
192 {
193   int argn;
194   char *arg;
195 
196   /* Set up default JPEG parameters. */
197   requested_fmt = DEFAULT_FMT;  /* set default output file format */
198   icc_filename = NULL;
199   max_scans = 0;
200   outfilename = NULL;
201   memsrc = FALSE;
202   report = FALSE;
203   skip = FALSE;
204   crop = FALSE;
205   strict = FALSE;
206   cinfo->err->trace_level = 0;
207 
208   /* Scan command line options, adjust parameters */
209 
210   for (argn = 1; argn < argc; argn++) {
211     arg = argv[argn];
212     if (*arg != '-') {
213       /* Not a switch, must be a file name argument */
214       if (argn <= last_file_arg_seen) {
215         outfilename = NULL;     /* -outfile applies to just one input file */
216         continue;               /* ignore this name if previously processed */
217       }
218       break;                    /* else done parsing switches */
219     }
220     arg++;                      /* advance past switch marker character */
221 
222     if (keymatch(arg, "bmp", 1)) {
223       /* BMP output format (Windows flavor). */
224       requested_fmt = FMT_BMP;
225 
226     } else if (keymatch(arg, "colors", 1) || keymatch(arg, "colours", 1) ||
227                keymatch(arg, "quantize", 1) || keymatch(arg, "quantise", 1)) {
228       /* Do color quantization. */
229       int val;
230 
231       if (++argn >= argc)       /* advance to next argument */
232         usage();
233       if (sscanf(argv[argn], "%d", &val) != 1)
234         usage();
235       cinfo->desired_number_of_colors = val;
236       cinfo->quantize_colors = TRUE;
237 
238     } else if (keymatch(arg, "dct", 2)) {
239       /* Select IDCT algorithm. */
240       if (++argn >= argc)       /* advance to next argument */
241         usage();
242       if (keymatch(argv[argn], "int", 1)) {
243         cinfo->dct_method = JDCT_ISLOW;
244       } else if (keymatch(argv[argn], "fast", 2)) {
245         cinfo->dct_method = JDCT_IFAST;
246       } else if (keymatch(argv[argn], "float", 2)) {
247         cinfo->dct_method = JDCT_FLOAT;
248       } else
249         usage();
250 
251     } else if (keymatch(arg, "dither", 2)) {
252       /* Select dithering algorithm. */
253       if (++argn >= argc)       /* advance to next argument */
254         usage();
255       if (keymatch(argv[argn], "fs", 2)) {
256         cinfo->dither_mode = JDITHER_FS;
257       } else if (keymatch(argv[argn], "none", 2)) {
258         cinfo->dither_mode = JDITHER_NONE;
259       } else if (keymatch(argv[argn], "ordered", 2)) {
260         cinfo->dither_mode = JDITHER_ORDERED;
261       } else
262         usage();
263 
264     } else if (keymatch(arg, "debug", 1) || keymatch(arg, "verbose", 1)) {
265       /* Enable debug printouts. */
266       /* On first -d, print version identification */
267       static boolean printed_version = FALSE;
268 
269       if (!printed_version) {
270         fprintf(stderr, "%s version %s (build %s)\n",
271                 PACKAGE_NAME, VERSION, BUILD);
272         fprintf(stderr, "%s\n\n", JCOPYRIGHT);
273         fprintf(stderr, "Emulating The Independent JPEG Group's software, version %s\n\n",
274                 JVERSION);
275         printed_version = TRUE;
276       }
277       cinfo->err->trace_level++;
278 
279     } else if (keymatch(arg, "version", 4)) {
280       fprintf(stderr, "%s version %s (build %s)\n",
281               PACKAGE_NAME, VERSION, BUILD);
282       exit(EXIT_SUCCESS);
283 
284     } else if (keymatch(arg, "fast", 1)) {
285       /* Select recommended processing options for quick-and-dirty output. */
286       cinfo->two_pass_quantize = FALSE;
287       cinfo->dither_mode = JDITHER_ORDERED;
288       if (!cinfo->quantize_colors) /* don't override an earlier -colors */
289         cinfo->desired_number_of_colors = 216;
290       cinfo->dct_method = JDCT_FASTEST;
291       cinfo->do_fancy_upsampling = FALSE;
292 
293     } else if (keymatch(arg, "gif", 1)) {
294       /* GIF output format (LZW-compressed). */
295       requested_fmt = FMT_GIF;
296 
297     } else if (keymatch(arg, "gif0", 4)) {
298       /* GIF output format (uncompressed). */
299       requested_fmt = FMT_GIF0;
300 
301     } else if (keymatch(arg, "grayscale", 2) ||
302                keymatch(arg, "greyscale", 2)) {
303       /* Force monochrome output. */
304       cinfo->out_color_space = JCS_GRAYSCALE;
305 
306     } else if (keymatch(arg, "rgb", 2)) {
307       /* Force RGB output. */
308       cinfo->out_color_space = JCS_RGB;
309 
310     } else if (keymatch(arg, "rgb565", 2)) {
311       /* Force RGB565 output. */
312       cinfo->out_color_space = JCS_RGB565;
313 
314     } else if (keymatch(arg, "icc", 1)) {
315       /* Set ICC filename. */
316       if (++argn >= argc)       /* advance to next argument */
317         usage();
318       icc_filename = argv[argn];
319       jpeg_save_markers(cinfo, JPEG_APP0 + 2, 0xFFFF);
320 
321     } else if (keymatch(arg, "map", 3)) {
322       /* Quantize to a color map taken from an input file. */
323       if (++argn >= argc)       /* advance to next argument */
324         usage();
325       if (for_real) {           /* too expensive to do twice! */
326 #ifdef QUANT_2PASS_SUPPORTED    /* otherwise can't quantize to supplied map */
327         FILE *mapfile;
328 
329         if ((mapfile = fopen(argv[argn], READ_BINARY)) == NULL) {
330           fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
331           exit(EXIT_FAILURE);
332         }
333         read_color_map(cinfo, mapfile);
334         fclose(mapfile);
335         cinfo->quantize_colors = TRUE;
336 #else
337         ERREXIT(cinfo, JERR_NOT_COMPILED);
338 #endif
339       }
340 
341     } else if (keymatch(arg, "maxmemory", 3)) {
342       /* Maximum memory in Kb (or Mb with 'm'). */
343       long lval;
344       char ch = 'x';
345 
346       if (++argn >= argc)       /* advance to next argument */
347         usage();
348       if (sscanf(argv[argn], "%ld%c", &lval, &ch) < 1)
349         usage();
350       if (ch == 'm' || ch == 'M')
351         lval *= 1000L;
352       cinfo->mem->max_memory_to_use = lval * 1000L;
353 
354     } else if (keymatch(arg, "maxscans", 4)) {
355       if (++argn >= argc)       /* advance to next argument */
356         usage();
357       if (sscanf(argv[argn], "%u", &max_scans) != 1)
358         usage();
359 
360     } else if (keymatch(arg, "nosmooth", 3)) {
361       /* Suppress fancy upsampling */
362       cinfo->do_fancy_upsampling = FALSE;
363 
364     } else if (keymatch(arg, "onepass", 3)) {
365       /* Use fast one-pass quantization. */
366       cinfo->two_pass_quantize = FALSE;
367 
368     } else if (keymatch(arg, "os2", 3)) {
369       /* BMP output format (OS/2 flavor). */
370       requested_fmt = FMT_OS2;
371 
372     } else if (keymatch(arg, "outfile", 4)) {
373       /* Set output file name. */
374       if (++argn >= argc)       /* advance to next argument */
375         usage();
376       outfilename = argv[argn]; /* save it away for later use */
377 
378     } else if (keymatch(arg, "memsrc", 2)) {
379       /* Use in-memory source manager */
380 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
381       memsrc = TRUE;
382 #else
383       fprintf(stderr, "%s: sorry, in-memory source manager was not compiled in\n",
384               progname);
385       exit(EXIT_FAILURE);
386 #endif
387 
388     } else if (keymatch(arg, "pnm", 1) || keymatch(arg, "ppm", 1)) {
389       /* PPM/PGM output format. */
390       requested_fmt = FMT_PPM;
391 
392     } else if (keymatch(arg, "report", 2)) {
393       report = TRUE;
394 
395     } else if (keymatch(arg, "scale", 2)) {
396       /* Scale the output image by a fraction M/N. */
397       if (++argn >= argc)       /* advance to next argument */
398         usage();
399       if (sscanf(argv[argn], "%u/%u",
400                  &cinfo->scale_num, &cinfo->scale_denom) != 2)
401         usage();
402 
403     } else if (keymatch(arg, "skip", 2)) {
404       if (++argn >= argc)
405         usage();
406       if (sscanf(argv[argn], "%u,%u", &skip_start, &skip_end) != 2 ||
407           skip_start > skip_end)
408         usage();
409       skip = TRUE;
410 
411     } else if (keymatch(arg, "crop", 2)) {
412       char c;
413       if (++argn >= argc)
414         usage();
415       if (sscanf(argv[argn], "%u%c%u+%u+%u", &crop_width, &c, &crop_height,
416                  &crop_x, &crop_y) != 5 ||
417           (c != 'X' && c != 'x') || crop_width < 1 || crop_height < 1)
418         usage();
419       crop = TRUE;
420 
421     } else if (keymatch(arg, "strict", 2)) {
422       strict = TRUE;
423 
424     } else if (keymatch(arg, "targa", 1)) {
425       /* Targa output format. */
426       requested_fmt = FMT_TARGA;
427 
428     } else {
429       usage();                  /* bogus switch */
430     }
431   }
432 
433   return argn;                  /* return index of next arg (file name) */
434 }
435 
436 
437 /*
438  * Marker processor for COM and interesting APPn markers.
439  * This replaces the library's built-in processor, which just skips the marker.
440  * We want to print out the marker as text, to the extent possible.
441  * Note this code relies on a non-suspending data source.
442  */
443 
444 LOCAL(unsigned int)
jpeg_getc(j_decompress_ptr cinfo)445 jpeg_getc(j_decompress_ptr cinfo)
446 /* Read next byte */
447 {
448   struct jpeg_source_mgr *datasrc = cinfo->src;
449 
450   if (datasrc->bytes_in_buffer == 0) {
451     if (!(*datasrc->fill_input_buffer) (cinfo))
452       ERREXIT(cinfo, JERR_CANT_SUSPEND);
453   }
454   datasrc->bytes_in_buffer--;
455   return *datasrc->next_input_byte++;
456 }
457 
458 
459 METHODDEF(boolean)
print_text_marker(j_decompress_ptr cinfo)460 print_text_marker(j_decompress_ptr cinfo)
461 {
462   boolean traceit = (cinfo->err->trace_level >= 1);
463   long length;
464   unsigned int ch;
465   unsigned int lastch = 0;
466 
467   length = jpeg_getc(cinfo) << 8;
468   length += jpeg_getc(cinfo);
469   length -= 2;                  /* discount the length word itself */
470 
471   if (traceit) {
472     if (cinfo->unread_marker == JPEG_COM)
473       fprintf(stderr, "Comment, length %ld:\n", (long)length);
474     else                        /* assume it is an APPn otherwise */
475       fprintf(stderr, "APP%d, length %ld:\n",
476               cinfo->unread_marker - JPEG_APP0, (long)length);
477   }
478 
479   while (--length >= 0) {
480     ch = jpeg_getc(cinfo);
481     if (traceit) {
482       /* Emit the character in a readable form.
483        * Nonprintables are converted to \nnn form,
484        * while \ is converted to \\.
485        * Newlines in CR, CR/LF, or LF form will be printed as one newline.
486        */
487       if (ch == '\r') {
488         fprintf(stderr, "\n");
489       } else if (ch == '\n') {
490         if (lastch != '\r')
491           fprintf(stderr, "\n");
492       } else if (ch == '\\') {
493         fprintf(stderr, "\\\\");
494       } else if (isprint(ch)) {
495         putc(ch, stderr);
496       } else {
497         fprintf(stderr, "\\%03o", ch);
498       }
499       lastch = ch;
500     }
501   }
502 
503   if (traceit)
504     fprintf(stderr, "\n");
505 
506   return TRUE;
507 }
508 
509 
510 METHODDEF(void)
my_emit_message(j_common_ptr cinfo,int msg_level)511 my_emit_message(j_common_ptr cinfo, int msg_level)
512 {
513   if (msg_level < 0) {
514     /* Treat warning as fatal */
515     cinfo->err->error_exit(cinfo);
516   } else {
517     if (cinfo->err->trace_level >= msg_level)
518       cinfo->err->output_message(cinfo);
519   }
520 }
521 
522 
523 /*
524  * The main program.
525  */
526 
527 int
main(int argc,char ** argv)528 main(int argc, char **argv)
529 {
530   struct jpeg_decompress_struct cinfo;
531   struct jpeg_error_mgr jerr;
532   struct cdjpeg_progress_mgr progress;
533   int file_index;
534   djpeg_dest_ptr dest_mgr = NULL;
535   FILE *input_file;
536   FILE *output_file;
537   unsigned char *inbuffer = NULL;
538 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
539   unsigned long insize = 0;
540 #endif
541   JDIMENSION num_scanlines;
542 
543   progname = argv[0];
544   if (progname == NULL || progname[0] == 0)
545     progname = "djpeg";         /* in case C library doesn't provide it */
546 
547   /* Initialize the JPEG decompression object with default error handling. */
548   cinfo.err = jpeg_std_error(&jerr);
549   jpeg_create_decompress(&cinfo);
550   /* Add some application-specific error messages (from cderror.h) */
551   jerr.addon_message_table = cdjpeg_message_table;
552   jerr.first_addon_message = JMSG_FIRSTADDONCODE;
553   jerr.last_addon_message = JMSG_LASTADDONCODE;
554 
555   /* Insert custom marker processor for COM and APP12.
556    * APP12 is used by some digital camera makers for textual info,
557    * so we provide the ability to display it as text.
558    * If you like, additional APPn marker types can be selected for display,
559    * but don't try to override APP0 or APP14 this way (see libjpeg.txt).
560    */
561   jpeg_set_marker_processor(&cinfo, JPEG_COM, print_text_marker);
562   jpeg_set_marker_processor(&cinfo, JPEG_APP0 + 12, print_text_marker);
563 
564   /* Scan command line to find file names. */
565   /* It is convenient to use just one switch-parsing routine, but the switch
566    * values read here are ignored; we will rescan the switches after opening
567    * the input file.
568    * (Exception: tracing level set here controls verbosity for COM markers
569    * found during jpeg_read_header...)
570    */
571 
572   file_index = parse_switches(&cinfo, argc, argv, 0, FALSE);
573 
574   if (strict)
575     jerr.emit_message = my_emit_message;
576 
577 #ifdef TWO_FILE_COMMANDLINE
578   /* Must have either -outfile switch or explicit output file name */
579   if (outfilename == NULL) {
580     if (file_index != argc - 2) {
581       fprintf(stderr, "%s: must name one input and one output file\n",
582               progname);
583       usage();
584     }
585     outfilename = argv[file_index + 1];
586   } else {
587     if (file_index != argc - 1) {
588       fprintf(stderr, "%s: must name one input and one output file\n",
589               progname);
590       usage();
591     }
592   }
593 #else
594   /* Unix style: expect zero or one file name */
595   if (file_index < argc - 1) {
596     fprintf(stderr, "%s: only one input file\n", progname);
597     usage();
598   }
599 #endif /* TWO_FILE_COMMANDLINE */
600 
601   /* Open the input file. */
602   if (file_index < argc) {
603     if ((input_file = fopen(argv[file_index], READ_BINARY)) == NULL) {
604       fprintf(stderr, "%s: can't open %s\n", progname, argv[file_index]);
605       exit(EXIT_FAILURE);
606     }
607   } else {
608     /* default input file is stdin */
609     input_file = read_stdin();
610   }
611 
612   /* Open the output file. */
613   if (outfilename != NULL) {
614     if ((output_file = fopen(outfilename, WRITE_BINARY)) == NULL) {
615       fprintf(stderr, "%s: can't open %s\n", progname, outfilename);
616       exit(EXIT_FAILURE);
617     }
618   } else {
619     /* default output file is stdout */
620     output_file = write_stdout();
621   }
622 
623   if (report || max_scans != 0) {
624     start_progress_monitor((j_common_ptr)&cinfo, &progress);
625     progress.report = report;
626     progress.max_scans = max_scans;
627   }
628 
629   /* Specify data source for decompression */
630 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
631   if (memsrc) {
632     size_t nbytes;
633     do {
634       inbuffer = (unsigned char *)realloc(inbuffer, insize + INPUT_BUF_SIZE);
635       if (inbuffer == NULL) {
636         fprintf(stderr, "%s: memory allocation failure\n", progname);
637         exit(EXIT_FAILURE);
638       }
639       nbytes = fread(&inbuffer[insize], 1, INPUT_BUF_SIZE, input_file);
640       if (nbytes < INPUT_BUF_SIZE && ferror(input_file)) {
641         if (file_index < argc)
642           fprintf(stderr, "%s: can't read from %s\n", progname,
643                   argv[file_index]);
644         else
645           fprintf(stderr, "%s: can't read from stdin\n", progname);
646       }
647       insize += (unsigned long)nbytes;
648     } while (nbytes == INPUT_BUF_SIZE);
649     fprintf(stderr, "Compressed size:  %lu bytes\n", insize);
650     jpeg_mem_src(&cinfo, inbuffer, insize);
651   } else
652 #endif
653     jpeg_stdio_src(&cinfo, input_file);
654 
655   /* Read file header, set default decompression parameters */
656   (void)jpeg_read_header(&cinfo, TRUE);
657 
658   /* Adjust default decompression parameters by re-parsing the options */
659   file_index = parse_switches(&cinfo, argc, argv, 0, TRUE);
660 
661   /* Initialize the output module now to let it override any crucial
662    * option settings (for instance, GIF wants to force color quantization).
663    */
664   switch (requested_fmt) {
665 #ifdef BMP_SUPPORTED
666   case FMT_BMP:
667     dest_mgr = jinit_write_bmp(&cinfo, FALSE, TRUE);
668     break;
669   case FMT_OS2:
670     dest_mgr = jinit_write_bmp(&cinfo, TRUE, TRUE);
671     break;
672 #endif
673 #ifdef GIF_SUPPORTED
674   case FMT_GIF:
675     dest_mgr = jinit_write_gif(&cinfo, TRUE);
676     break;
677   case FMT_GIF0:
678     dest_mgr = jinit_write_gif(&cinfo, FALSE);
679     break;
680 #endif
681 #ifdef PPM_SUPPORTED
682   case FMT_PPM:
683     dest_mgr = jinit_write_ppm(&cinfo);
684     break;
685 #endif
686 #ifdef TARGA_SUPPORTED
687   case FMT_TARGA:
688     dest_mgr = jinit_write_targa(&cinfo);
689     break;
690 #endif
691   default:
692     ERREXIT(&cinfo, JERR_UNSUPPORTED_FORMAT);
693     break;
694   }
695   dest_mgr->output_file = output_file;
696 
697   /* Start decompressor */
698   (void)jpeg_start_decompress(&cinfo);
699 
700   /* Skip rows */
701   if (skip) {
702     JDIMENSION tmp;
703 
704     /* Check for valid skip_end.  We cannot check this value until after
705      * jpeg_start_decompress() is called.  Note that we have already verified
706      * that skip_start <= skip_end.
707      */
708     if (skip_end > cinfo.output_height - 1) {
709       fprintf(stderr, "%s: skip region exceeds image height %u\n", progname,
710               cinfo.output_height);
711       exit(EXIT_FAILURE);
712     }
713 
714     /* Write output file header.  This is a hack to ensure that the destination
715      * manager creates an output image of the proper size.
716      */
717     tmp = cinfo.output_height;
718     cinfo.output_height -= (skip_end - skip_start + 1);
719     (*dest_mgr->start_output) (&cinfo, dest_mgr);
720     cinfo.output_height = tmp;
721 
722     /* Process data */
723     while (cinfo.output_scanline < skip_start) {
724       num_scanlines = jpeg_read_scanlines(&cinfo, dest_mgr->buffer,
725                                           dest_mgr->buffer_height);
726       (*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines);
727     }
728     if ((tmp = jpeg_skip_scanlines(&cinfo, skip_end - skip_start + 1)) !=
729         skip_end - skip_start + 1) {
730       fprintf(stderr, "%s: jpeg_skip_scanlines() returned %u rather than %u\n",
731               progname, tmp, skip_end - skip_start + 1);
732       exit(EXIT_FAILURE);
733     }
734     while (cinfo.output_scanline < cinfo.output_height) {
735       num_scanlines = jpeg_read_scanlines(&cinfo, dest_mgr->buffer,
736                                           dest_mgr->buffer_height);
737       (*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines);
738     }
739 
740   /* Decompress a subregion */
741   } else if (crop) {
742     JDIMENSION tmp;
743 
744     /* Check for valid crop dimensions.  We cannot check these values until
745      * after jpeg_start_decompress() is called.
746      */
747     if (crop_x + crop_width > cinfo.output_width ||
748         crop_y + crop_height > cinfo.output_height) {
749       fprintf(stderr, "%s: crop dimensions exceed image dimensions %u x %u\n",
750               progname, cinfo.output_width, cinfo.output_height);
751       exit(EXIT_FAILURE);
752     }
753 
754     jpeg_crop_scanline(&cinfo, &crop_x, &crop_width);
755     if (dest_mgr->calc_buffer_dimensions)
756       (*dest_mgr->calc_buffer_dimensions) (&cinfo, dest_mgr);
757     else
758       ERREXIT(&cinfo, JERR_UNSUPPORTED_FORMAT);
759 
760     /* Write output file header.  This is a hack to ensure that the destination
761      * manager creates an output image of the proper size.
762      */
763     tmp = cinfo.output_height;
764     cinfo.output_height = crop_height;
765     (*dest_mgr->start_output) (&cinfo, dest_mgr);
766     cinfo.output_height = tmp;
767 
768     /* Process data */
769     if ((tmp = jpeg_skip_scanlines(&cinfo, crop_y)) != crop_y) {
770       fprintf(stderr, "%s: jpeg_skip_scanlines() returned %u rather than %u\n",
771               progname, tmp, crop_y);
772       exit(EXIT_FAILURE);
773     }
774     while (cinfo.output_scanline < crop_y + crop_height) {
775       num_scanlines = jpeg_read_scanlines(&cinfo, dest_mgr->buffer,
776                                           dest_mgr->buffer_height);
777       (*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines);
778     }
779     if ((tmp =
780          jpeg_skip_scanlines(&cinfo,
781                              cinfo.output_height - crop_y - crop_height)) !=
782         cinfo.output_height - crop_y - crop_height) {
783       fprintf(stderr, "%s: jpeg_skip_scanlines() returned %u rather than %u\n",
784               progname, tmp, cinfo.output_height - crop_y - crop_height);
785       exit(EXIT_FAILURE);
786     }
787 
788   /* Normal full-image decompress */
789   } else {
790     /* Write output file header */
791     (*dest_mgr->start_output) (&cinfo, dest_mgr);
792 
793     /* Process data */
794     while (cinfo.output_scanline < cinfo.output_height) {
795       num_scanlines = jpeg_read_scanlines(&cinfo, dest_mgr->buffer,
796                                           dest_mgr->buffer_height);
797       (*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines);
798     }
799   }
800 
801   /* Hack: count final pass as done in case finish_output does an extra pass.
802    * The library won't have updated completed_passes.
803    */
804   if (report || max_scans != 0)
805     progress.pub.completed_passes = progress.pub.total_passes;
806 
807   if (icc_filename != NULL) {
808     FILE *icc_file;
809     JOCTET *icc_profile;
810     unsigned int icc_len;
811 
812     if ((icc_file = fopen(icc_filename, WRITE_BINARY)) == NULL) {
813       fprintf(stderr, "%s: can't open %s\n", progname, icc_filename);
814       exit(EXIT_FAILURE);
815     }
816     if (jpeg_read_icc_profile(&cinfo, &icc_profile, &icc_len)) {
817       if (fwrite(icc_profile, icc_len, 1, icc_file) < 1) {
818         fprintf(stderr, "%s: can't read ICC profile from %s\n", progname,
819                 icc_filename);
820         free(icc_profile);
821         fclose(icc_file);
822         exit(EXIT_FAILURE);
823       }
824       free(icc_profile);
825       fclose(icc_file);
826     } else if (cinfo.err->msg_code != JWRN_BOGUS_ICC)
827       fprintf(stderr, "%s: no ICC profile data in JPEG file\n", progname);
828   }
829 
830   /* Finish decompression and release memory.
831    * I must do it in this order because output module has allocated memory
832    * of lifespan JPOOL_IMAGE; it needs to finish before releasing memory.
833    */
834   (*dest_mgr->finish_output) (&cinfo, dest_mgr);
835   (void)jpeg_finish_decompress(&cinfo);
836   jpeg_destroy_decompress(&cinfo);
837 
838   /* Close files, if we opened them */
839   if (input_file != stdin)
840     fclose(input_file);
841   if (output_file != stdout)
842     fclose(output_file);
843 
844   if (report || max_scans != 0)
845     end_progress_monitor((j_common_ptr)&cinfo);
846 
847   if (memsrc)
848     free(inbuffer);
849 
850   /* All done. */
851   exit(jerr.num_warnings ? EXIT_WARNING : EXIT_SUCCESS);
852   return 0;                     /* suppress no-return-value warnings */
853 }
854