compiler/libjpeg/test/cjpeg.c

   1 /*
   2     $Id$
   3 */
   4
   5 /*
   6  * cjpeg.c
   7  *
   8  * Copyright (C) 1991-1998, Thomas G. Lane.
   9  * This file is part of the Independent JPEG Group's software.
  10  * For conditions of distribution and use, see the accompanying README file.
  11  *
  12  * This file contains a command-line user interface for the JPEG compressor.
  13  * It should work on any system with Unix- or MS-DOS-style command lines.
  14  *
  15  * Two different command line styles are permitted, depending on the
  16  * compile-time switch TWO_FILE_COMMANDLINE:
  17  *      cjpeg [options]  inputfile outputfile
  18  *      cjpeg [options]  [inputfile]
  19  * In the second style, output is always to standard output, which you'd
  20  * normally redirect to a file or pipe to some other program.  Input is
  21  * either from a named file or from standard input (typically redirected).
  22  * The second style is convenient on Unix but is unhelpful on systems that
  23  * don't support pipes.  Also, you MUST use the first style if your system
  24  * doesn't do binary I/O to stdin/stdout.
  25  * To simplify script writing, the "-outfile" switch is provided.  The syntax
  26  *      cjpeg [options]  -outfile outputfile  inputfile
  27  * works regardless of which command line style is used.
  28  */
  29
  30 #include <stdio.h>
  31 #include "cdjpeg.h"             /* Common decls for cjpeg/djpeg applications */
  32 #include "jversion.h"           /* for version message */
  33
  34 #ifdef USE_CCOMMAND             /* command-line reader for Macintosh */
  35 #ifdef __MWERKS__
  36 #include <SIOUX.h>              /* Metrowerks needs this */
  37 #include <console.h>            /* ... and this */
  38 #endif
  39 #ifdef THINK_C
  40 #include <console.h>            /* Think declares it here */
  41 #endif
  42 #endif
  43
  44
  45 /* Create the add-on message string table. */
  46
  47 #define JMESSAGE(code,string)   string ,
  48
  49 static const char * const cdjpeg_message_table[] = {
  50 #include "cderror.h"
  51   NULL
  52 };
  53
  54
  55 /*
  56  * This routine determines what format the input file is,
  57  * and selects the appropriate input-reading module.
  58  *
  59  * To determine which family of input formats the file belongs to,
  60  * we may look only at the first byte of the file, since C does not
  61  * guarantee that more than one character can be pushed back with ungetc.
  62  * Looking at additional bytes would require one of these approaches:
  63  *     1) assume we can fseek() the input file (fails for piped input);
  64  *     2) assume we can push back more than one character (works in
  65  *        some C implementations, but unportable);
  66  *     3) provide our own buffering (breaks input readers that want to use
  67  *        stdio directly, such as the RLE library);
  68  * or  4) don't put back the data, and modify the input_init methods to assume
  69  *        they start reading after the start of file (also breaks RLE library).
  70  * #1 is attractive for MS-DOS but is untenable on Unix.
  71  *
  72  * The most portable solution for file types that can't be identified by their
  73  * first byte is to make the user tell us what they are.  This is also the
  74  * only approach for "raw" file types that contain only arbitrary values.
  75  * We presently apply this method for Targa files.  Most of the time Targa
  76  * files start with 0x00, so we recognize that case.  Potentially, however,
  77  * a Targa file could start with any byte value (byte 0 is the length of the
  78  * seldom-used ID field), so we provide a switch to force Targa input mode.
  79  */
  80
  81 static boolean is_targa;        /* records user -targa switch */
  82
  83
  84 LOCAL(cjpeg_source_ptr)
  85 select_file_type (j_compress_ptr cinfo, FILE * infile)
  86 {
  87   int c;
  88
  89   if (is_targa) {
  90 #ifdef TARGA_SUPPORTED
  91     return jinit_read_targa(cinfo);
  92 #else
  93     ERREXIT(cinfo, JERR_TGA_NOTCOMP);
  94 #endif
  95   }
  96
  97   if ((c = getc(infile)) == EOF)
  98     ERREXIT(cinfo, JERR_INPUT_EMPTY);
  99   if (ungetc(c, infile) == EOF)
 100     ERREXIT(cinfo, JERR_UNGETC_FAILED);
 101
 102   switch (c) {
 103 #ifdef BMP_SUPPORTED
 104   case 'B':
 105     return jinit_read_bmp(cinfo);
 106 #endif
 107 #ifdef GIF_SUPPORTED
 108   case 'G':
 109     return jinit_read_gif(cinfo);
 110 #endif
 111 #ifdef PPM_SUPPORTED
 112   case 'P':
 113     return jinit_read_ppm(cinfo);
 114 #endif
 115 #ifdef RLE_SUPPORTED
 116   case 'R':
 117     return jinit_read_rle(cinfo);
 118 #endif
 119 #ifdef TARGA_SUPPORTED
 120   case 0x00:
 121     return jinit_read_targa(cinfo);
 122 #endif
 123   default:
 124     ERREXIT(cinfo, JERR_UNKNOWN_FORMAT);
 125     break;
 126   }
 127
 128   return NULL;                  /* suppress compiler warnings */
 129 }
 130
 131
 132 /*
 133  * Argument-parsing code.
 134  * The switch parser is designed to be useful with DOS-style command line
 135  * syntax, ie, intermixed switches and file names, where only the switches
 136  * to the left of a given file name affect processing of that file.
 137  * The main program in this file doesn't actually use this capability...
 138  */
 139
 140
 141 static const char * progname;   /* program name for error messages */
 142 static char * outfilename;      /* for -outfile switch */
 143
 144
 145 LOCAL(void)
 146 usage (void)
 147 /* complain about bad command line */
 148 {
 149   fprintf(stderr, "usage: %s [switches] ", progname);
 150 #ifdef TWO_FILE_COMMANDLINE
 151   fprintf(stderr, "inputfile outputfile\n");
 152 #else
 153   fprintf(stderr, "[inputfile]\n");
 154 #endif
 155
 156   fprintf(stderr, "Switches (names may be abbreviated):\n");
 157   fprintf(stderr, "  -quality N     Compression quality (0..100; 5-95 is useful range)\n");
 158   fprintf(stderr, "  -grayscale     Create monochrome JPEG file\n");
 159 #ifdef ENTROPY_OPT_SUPPORTED
 160   fprintf(stderr, "  -optimize      Optimize Huffman table (smaller file, but slow compression)\n");
 161 #endif
 162 #ifdef C_PROGRESSIVE_SUPPORTED
 163   fprintf(stderr, "  -progressive   Create progressive JPEG file\n");
 164 #endif
 165 #ifdef C_LOSSLESS_SUPPORTED
 166   fprintf(stderr, "  -lossless psv[,Pt]  Create lossless JPEG file\n");
 167 #endif
 168 #ifdef TARGA_SUPPORTED
 169   fprintf(stderr, "  -targa         Input file is Targa format (usually not needed)\n");
 170 #endif
 171   fprintf(stderr, "Switches for advanced users:\n");
 172 #ifdef DCT_ISLOW_SUPPORTED
 173   fprintf(stderr, "  -dct int       Use integer DCT method%s\n",
 174           (JDCT_DEFAULT == JDCT_ISLOW ? " (default)" : ""));
 175 #endif
 176 #ifdef DCT_IFAST_SUPPORTED
 177   fprintf(stderr, "  -dct fast      Use fast integer DCT (less accurate)%s\n",
 178           (JDCT_DEFAULT == JDCT_IFAST ? " (default)" : ""));
 179 #endif
 180 #ifdef DCT_FLOAT_SUPPORTED
 181   fprintf(stderr, "  -dct float     Use floating-point DCT method%s\n",
 182           (JDCT_DEFAULT == JDCT_FLOAT ? " (default)" : ""));
 183 #endif
 184   fprintf(stderr, "  -restart N     Set restart interval in rows, or in blocks with B\n");
 185 #ifdef INPUT_SMOOTHING_SUPPORTED
 186   fprintf(stderr, "  -smooth N      Smooth dithered input (N=1..100 is strength)\n");
 187 #endif
 188   fprintf(stderr, "  -maxmemory N   Maximum memory to use (in kbytes)\n");
 189   fprintf(stderr, "  -outfile name  Specify name for output file\n");
 190   fprintf(stderr, "  -verbose  or  -debug   Emit debug output\n");
 191   fprintf(stderr, "Switches for wizards:\n");
 192 #ifdef C_ARITH_CODING_SUPPORTED
 193   fprintf(stderr, "  -arithmetic    Use arithmetic coding\n");
 194 #endif
 195   fprintf(stderr, "  -baseline      Force baseline quantization tables\n");
 196   fprintf(stderr, "  -qtables file  Use quantization tables given in file\n");
 197   fprintf(stderr, "  -qslots N[,...]    Set component quantization tables\n");
 198   fprintf(stderr, "  -sample HxV[,...]  Set component sampling factors\n");
 199 #ifdef C_MULTISCAN_FILES_SUPPORTED
 200   fprintf(stderr, "  -scans file    Create multi-scan JPEG per script file\n");
 201 #endif
 202   exit(EXIT_FAILURE);
 203 }
 204
 205
 206 LOCAL(int)
 207 parse_switches (j_compress_ptr cinfo, int argc, char **argv,
 208                 int last_file_arg_seen, boolean for_real)
 209 /* Parse optional switches.
 210  * Returns argv[] index of first file-name argument (== argc if none).
 211  * Any file names with indexes <= last_file_arg_seen are ignored;
 212  * they have presumably been processed in a previous iteration.
 213  * (Pass 0 for last_file_arg_seen on the first or only iteration.)
 214  * for_real is FALSE on the first (dummy) pass; we may skip any expensive
 215  * processing.
 216  */
 217 {
 218   int argn;
 219   char * arg;
 220   int quality;                  /* -quality parameter */
 221   int q_scale_factor;           /* scaling percentage for -qtables */
 222   boolean force_baseline;
 223   boolean simple_progressive;
 224   char * qtablefile = NULL;     /* saves -qtables filename if any */
 225   char * qslotsarg = NULL;      /* saves -qslots parm if any */
 226   char * samplearg = NULL;      /* saves -sample parm if any */
 227   char * scansarg = NULL;       /* saves -scans parm if any */
 228   char * losslsarg = NULL;      /* saves -lossless parm if any */
 229
 230   /* Set up default JPEG parameters. */
 231   /* Note that default -quality level need not, and does not,
 232    * match the default scaling for an explicit -qtables argument.
 233    */
 234   quality = 75;                 /* default -quality value */
 235   q_scale_factor = 100;         /* default to no scaling for -qtables */
 236   force_baseline = FALSE;       /* by default, allow 16-bit quantizers */
 237   simple_progressive = FALSE;
 238   is_targa = FALSE;
 239   outfilename = NULL;
 240   cinfo->err->trace_level = 0;
 241
 242   /* Scan command line options, adjust parameters */
 243
 244   for (argn = 1; argn < argc; argn++) {
 245     arg = argv[argn];
 246     if (*arg != '-') {
 247       /* Not a switch, must be a file name argument */
 248       if (argn <= last_file_arg_seen) {
 249         outfilename = NULL;     /* -outfile applies to just one input file */
 250         continue;               /* ignore this name if previously processed */
 251       }
 252       break;                    /* else done parsing switches */
 253     }
 254     arg++;                      /* advance past switch marker character */
 255
 256     if (keymatch(arg, "arithmetic", 1)) {
 257       /* Use arithmetic coding. */
 258 #ifdef C_ARITH_CODING_SUPPORTED
 259       cinfo->arith_code = TRUE;
 260 #else
 261       fprintf(stderr, "%s: sorry, arithmetic coding not supported\n",
 262               progname);
 263       exit(EXIT_FAILURE);
 264 #endif
 265
 266     } else if (keymatch(arg, "baseline", 1)) {
 267       /* Force baseline-compatible output (8-bit quantizer values). */
 268       force_baseline = TRUE;
 269
 270     } else if (keymatch(arg, "dct", 2)) {
 271       /* Select DCT algorithm. */
 272       if (++argn >= argc)       /* advance to next argument */
 273         usage();
 274       if (keymatch(argv[argn], "int", 1)) {
 275         cinfo->dct_method = JDCT_ISLOW;
 276       } else if (keymatch(argv[argn], "fast", 2)) {
 277         cinfo->dct_method = JDCT_IFAST;
 278       } else if (keymatch(argv[argn], "float", 2)) {
 279         cinfo->dct_method = JDCT_FLOAT;
 280       } else
 281         usage();
 282
 283     } else if (keymatch(arg, "debug", 1) || keymatch(arg, "verbose", 1)) {
 284       /* Enable debug printouts. */
 285       /* On first -d, print version identification */
 286       static boolean printed_version = FALSE;
 287
 288       if (! printed_version) {
 289         fprintf(stderr, "Independent JPEG Group's CJPEG, version %s\n%s\n",
 290                 JVERSION, JCOPYRIGHT);
 291         printed_version = TRUE;
 292       }
 293       cinfo->err->trace_level++;
 294
 295     } else if (keymatch(arg, "grayscale", 2) || keymatch(arg, "greyscale",2)) {
 296       /* Force a monochrome JPEG file to be generated. */
 297       jpeg_set_colorspace(cinfo, JCS_GRAYSCALE);
 298
 299     } else if (keymatch(arg, "lossless", 1)) {
 300 /* Select simple lossless mode. */
 301 #ifdef C_LOSSLESS_SUPPORTED
 302       if (++argn >= argc)       /* advance to next argument */
 303         usage();
 304       losslsarg = argv[argn];
 305       /* We must postpone execution until num_components is known. */
 306 #else
 307       fprintf(stderr, "%s: sorry, lossless output was not compiled\n",
 308               progname);
 309       exit(EXIT_FAILURE);
 310 #endif
 311
 312     } else if (keymatch(arg, "maxmemory", 3)) {
 313       /* Maximum memory in Kb (or Mb with 'm'). */
 314       long lval;
 315       char ch = 'x';
 316
 317       if (++argn >= argc)       /* advance to next argument */
 318         usage();
 319       if (sscanf(argv[argn], "%ld%c", &lval, &ch) < 1)
 320         usage();
 321       if (ch == 'm' || ch == 'M')
 322         lval *= 1000L;
 323       cinfo->mem->max_memory_to_use = lval * 1000L;
 324
 325     } else if (keymatch(arg, "optimize", 1) || keymatch(arg, "optimise", 1)) {
 326       /* Enable entropy parm optimization. */
 327 #ifdef ENTROPY_OPT_SUPPORTED
 328       cinfo->optimize_coding = TRUE;
 329 #else
 330       fprintf(stderr, "%s: sorry, entropy optimization was not compiled\n",
 331               progname);
 332       exit(EXIT_FAILURE);
 333 #endif
 334
 335     } else if (keymatch(arg, "outfile", 4)) {
 336       /* Set output file name. */
 337       if (++argn >= argc)       /* advance to next argument */
 338         usage();
 339       outfilename = argv[argn]; /* save it away for later use */
 340
 341     } else if (keymatch(arg, "progressive", 1)) {
 342       /* Select simple progressive mode. */
 343 #ifdef C_PROGRESSIVE_SUPPORTED
 344       simple_progressive = TRUE;
 345       /* We must postpone execution until num_components is known. */
 346 #else
 347       fprintf(stderr, "%s: sorry, progressive output was not compiled\n",
 348               progname);
 349       exit(EXIT_FAILURE);
 350 #endif
 351
 352     } else if (keymatch(arg, "quality", 1)) {
 353       /* Quality factor (quantization table scaling factor). */
 354       if (++argn >= argc)       /* advance to next argument */
 355         usage();
 356       if (sscanf(argv[argn], "%d", &quality) != 1)
 357         usage();
 358       /* Change scale factor in case -qtables is present. */
 359       q_scale_factor = jpeg_quality_scaling(quality);
 360
 361     } else if (keymatch(arg, "qslots", 2)) {
 362       /* Quantization table slot numbers. */
 363       if (++argn >= argc)       /* advance to next argument */
 364         usage();
 365       qslotsarg = argv[argn];
 366       /* Must delay setting qslots until after we have processed any
 367        * colorspace-determining switches, since jpeg_set_colorspace sets
 368        * default quant table numbers.
 369        */
 370
 371     } else if (keymatch(arg, "qtables", 2)) {
 372       /* Quantization tables fetched from file. */
 373       if (++argn >= argc)       /* advance to next argument */
 374         usage();
 375       qtablefile = argv[argn];
 376       /* We postpone actually reading the file in case -quality comes later. */
 377
 378     } else if (keymatch(arg, "restart", 1)) {
 379       /* Restart interval in MCU rows (or in MCUs with 'b'). */
 380       long lval;
 381       char ch = 'x';
 382
 383       if (++argn >= argc)       /* advance to next argument */
 384         usage();
 385       if (sscanf(argv[argn], "%ld%c", &lval, &ch) < 1)
 386         usage();
 387       if (lval < 0 || lval > 65535L)
 388         usage();
 389       if (ch == 'b' || ch == 'B') {
 390         cinfo->restart_interval = (unsigned int) lval;
 391         cinfo->restart_in_rows = 0; /* else prior '-restart n' overrides me */
 392       } else {
 393         cinfo->restart_in_rows = (int) lval;
 394         /* restart_interval will be computed during startup */
 395       }
 396
 397     } else if (keymatch(arg, "sample", 2)) {
 398       /* Set sampling factors. */
 399       if (++argn >= argc)       /* advance to next argument */
 400         usage();
 401       samplearg = argv[argn];
 402       /* Must delay setting sample factors until after we have processed any
 403        * colorspace-determining switches, since jpeg_set_colorspace sets
 404        * default sampling factors.
 405        */
 406
 407     } else if (keymatch(arg, "scans", 2)) {
 408       /* Set scan script. */
 409 #ifdef C_MULTISCAN_FILES_SUPPORTED
 410       if (++argn >= argc)       /* advance to next argument */
 411         usage();
 412       scansarg = argv[argn];
 413       /* We must postpone reading the file in case -progressive appears. */
 414 #else
 415       fprintf(stderr, "%s: sorry, multi-scan output was not compiled\n",
 416               progname);
 417       exit(EXIT_FAILURE);
 418 #endif
 419
 420     } else if (keymatch(arg, "smooth", 2)) {
 421       /* Set input smoothing factor. */
 422       int val;
 423
 424       if (++argn >= argc)       /* advance to next argument */
 425         usage();
 426       if (sscanf(argv[argn], "%d", &val) != 1)
 427         usage();
 428       if (val < 0 || val > 100)
 429         usage();
 430       cinfo->smoothing_factor = val;
 431
 432     } else if (keymatch(arg, "targa", 1)) {
 433       /* Input file is Targa format. */
 434       is_targa = TRUE;
 435
 436     } else {
 437       usage();                  /* bogus switch */
 438     }
 439   }
 440
 441   /* Post-switch-scanning cleanup */
 442
 443   if (for_real) {
 444
 445     /* Set quantization tables for selected quality. */
 446     /* Some or all may be overridden if -qtables is present. */
 447     jpeg_set_quality(cinfo, quality, force_baseline);
 448
 449     if (qtablefile != NULL)     /* process -qtables if it was present */
 450       if (! read_quant_tables(cinfo, qtablefile,
 451                               q_scale_factor, force_baseline))
 452         usage();
 453
 454     if (qslotsarg != NULL)      /* process -qslots if it was present */
 455       if (! set_quant_slots(cinfo, qslotsarg))
 456         usage();
 457
 458     if (samplearg != NULL)      /* process -sample if it was present */
 459       if (! set_sample_factors(cinfo, samplearg))
 460         usage();
 461
 462 #ifdef C_PROGRESSIVE_SUPPORTED
 463     if (simple_progressive)     /* process -progressive; -scans can override */
 464       jpeg_simple_progression(cinfo);
 465 #endif
 466
 467 #ifdef C_LOSSLESS_SUPPORTED
 468     if (losslsarg != NULL)      /* process -lossless if it was present */
 469       if (! set_simple_lossless(cinfo, losslsarg))
 470         usage();
 471 #endif
 472
 473 #ifdef C_MULTISCAN_FILES_SUPPORTED
 474     if (scansarg != NULL)       /* process -scans if it was present */
 475       if (! read_scan_script(cinfo, scansarg))
 476         usage();
 477 #endif
 478   }
 479
 480   return argn;                  /* return index of next arg (file name) */
 481 }
 482
 483
 484 /*
 485  * The main program.
 486  */
 487
 488 int
 489 main (int argc, char **argv)
 490 {
 491   struct jpeg_compress_struct cinfo;
 492   struct jpeg_error_mgr jerr;
 493 #ifdef PROGRESS_REPORT
 494   struct cdjpeg_progress_mgr progress;
 495 #endif
 496   int file_index;
 497   cjpeg_source_ptr src_mgr;
 498   FILE * input_file;
 499   FILE * output_file;
 500   JDIMENSION num_scanlines;
 501
 502   /* On Mac, fetch a command line. */
 503 #ifdef USE_CCOMMAND
 504   argc = ccommand(&argv);
 505 #endif
 506
 507   progname = argv[0];
 508   if (progname == NULL || progname[0] == 0)
 509     progname = "cjpeg";         /* in case C library doesn't provide it */
 510
 511   /* Initialize the JPEG compression object with default error handling. */
 512   cinfo.err = jpeg_std_error(&jerr);
 513   jpeg_create_compress(&cinfo);
 514   /* Add some application-specific error messages (from cderror.h) */
 515   jerr.addon_message_table = cdjpeg_message_table;
 516   jerr.first_addon_message = JMSG_FIRSTADDONCODE;
 517   jerr.last_addon_message = JMSG_LASTADDONCODE;
 518
 519   /* Now safe to enable signal catcher. */
 520 #ifdef NEED_SIGNAL_CATCHER
 521   enable_signal_catcher((j_common_ptr) &cinfo);
 522 #endif
 523
 524   /* Initialize JPEG parameters.
 525    * Much of this may be overridden later.
 526    * In particular, we don't yet know the input file's color space,
 527    * but we need to provide some value for jpeg_set_defaults() to work.
 528    */
 529
 530   cinfo.in_color_space = JCS_RGB; /* arbitrary guess */
 531   jpeg_set_defaults(&cinfo);
 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    */
 538
 539   file_index = parse_switches(&cinfo, argc, argv, 0, FALSE);
 540
 541 #ifdef TWO_FILE_COMMANDLINE
 542   /* Must have either -outfile switch or explicit output file name */
 543   if (outfilename == NULL) {
 544     if (file_index != argc-2) {
 545       fprintf(stderr, "%s: must name one input and one output file\n",
 546               progname);
 547       usage();
 548     }
 549     outfilename = argv[file_index+1];
 550   } else {
 551     if (file_index != argc-1) {
 552       fprintf(stderr, "%s: must name one input and one output file\n",
 553               progname);
 554       usage();
 555     }
 556   }
 557 #else
 558   /* Unix style: expect zero or one file name */
 559   if (file_index < argc-1) {
 560     fprintf(stderr, "%s: only one input file\n", progname);
 561     usage();
 562   }
 563 #endif /* TWO_FILE_COMMANDLINE */
 564
 565   /* Open the input file. */
 566   if (file_index < argc) {
 567     if ((input_file = fopen(argv[file_index], READ_BINARY)) == NULL) {
 568       fprintf(stderr, "%s: can't open %s\n", progname, argv[file_index]);
 569       exit(EXIT_FAILURE);
 570     }
 571   } else {
 572     /* default input file is stdin */
 573     input_file = read_stdin();
 574   }
 575
 576   /* Open the output file. */
 577   if (outfilename != NULL) {
 578     if ((output_file = fopen(outfilename, WRITE_BINARY)) == NULL) {
 579       fprintf(stderr, "%s: can't open %s\n", progname, outfilename);
 580       exit(EXIT_FAILURE);
 581     }
 582   } else {
 583     /* default output file is stdout */
 584     output_file = write_stdout();
 585   }
 586
 587 #ifdef PROGRESS_REPORT
 588   start_progress_monitor((j_common_ptr) &cinfo, &progress);
 589 #endif
 590
 591   /* Figure out the input file format, and set up to read it. */
 592   src_mgr = select_file_type(&cinfo, input_file);
 593   src_mgr->input_file = input_file;
 594
 595   /* Read the input file header to obtain file size & colorspace. */
 596   (*src_mgr->start_input) (&cinfo, src_mgr);
 597
 598   /* Now that we know input colorspace, fix colorspace-dependent defaults */
 599   jpeg_default_colorspace(&cinfo);
 600
 601   /* Adjust default compression parameters by re-parsing the options */
 602   file_index = parse_switches(&cinfo, argc, argv, 0, TRUE);
 603
 604   /* Specify data destination for compression */
 605   jpeg_stdio_dest(&cinfo, output_file);
 606
 607   /* Start compressor */
 608   jpeg_start_compress(&cinfo, TRUE);
 609
 610   /* Process data */
 611   while (cinfo.next_scanline < cinfo.image_height) {
 612     num_scanlines = (*src_mgr->get_pixel_rows) (&cinfo, src_mgr);
 613     (void) jpeg_write_scanlines(&cinfo, src_mgr->buffer, num_scanlines);
 614   }
 615
 616   /* Finish compression and release memory */
 617   (*src_mgr->finish_input) (&cinfo, src_mgr);
 618   jpeg_finish_compress(&cinfo);
 619   jpeg_destroy_compress(&cinfo);
 620
 621   /* Close files, if we opened them */
 622   if (input_file != stdin)
 623     fclose(input_file);
 624   if (output_file != stdout)
 625     fclose(output_file);
 626
 627 #ifdef PROGRESS_REPORT
 628   end_progress_monitor((j_common_ptr) &cinfo);
 629 #endif
 630
 631   /* All done. */
 632   exit(jerr.num_warnings ? EXIT_WARNING : EXIT_SUCCESS);
 633   return 0;                     /* suppress no-return-value warnings */
 634 }