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