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src/Source/LibJPEG/jpegtran.c  view on Meta::CPAN

  jvirt_barray_ptr * src_coef_arrays;
  jvirt_barray_ptr * dst_coef_arrays;
  int file_index;
  /* We assume all-in-memory processing and can therefore use only a
   * single file pointer for sequential input and output operation. 
   */
  FILE * fp;

  /* On Mac, fetch a command line. */
#ifdef USE_CCOMMAND
  argc = ccommand(&argv);
#endif

  progname = argv[0];
  if (progname == NULL || progname[0] == 0)
    progname = "jpegtran";	/* in case C library doesn't provide it */

  /* Initialize the JPEG decompression object with default error handling. */
  srcinfo.err = jpeg_std_error(&jsrcerr);
  jpeg_create_decompress(&srcinfo);
  /* Initialize the JPEG compression object with default error handling. */
  dstinfo.err = jpeg_std_error(&jdsterr);
  jpeg_create_compress(&dstinfo);

  /* Now safe to enable signal catcher.
   * Note: we assume only the decompression object will have virtual arrays.
   */
#ifdef NEED_SIGNAL_CATCHER
  enable_signal_catcher((j_common_ptr) &srcinfo);
#endif

  /* Scan command line to find file names.
   * It is convenient to use just one switch-parsing routine, but the switch
   * values read here are mostly ignored; we will rescan the switches after
   * opening the input file.  Also note that most of the switches affect the
   * destination JPEG object, so we parse into that and then copy over what
   * needs to affects the source too.
   */

  file_index = parse_switches(&dstinfo, argc, argv, 0, FALSE);
  jsrcerr.trace_level = jdsterr.trace_level;
  srcinfo.mem->max_memory_to_use = dstinfo.mem->max_memory_to_use;

#ifdef TWO_FILE_COMMANDLINE
  /* Must have either -outfile switch or explicit output file name */
  if (outfilename == NULL) {
    if (file_index != argc-2) {
      fprintf(stderr, "%s: must name one input and one output file\n",
	      progname);
      usage();
    }
    outfilename = argv[file_index+1];
  } else {
    if (file_index != argc-1) {
      fprintf(stderr, "%s: must name one input and one output file\n",
	      progname);
      usage();
    }
  }
#else
  /* Unix style: expect zero or one file name */
  if (file_index < argc-1) {
    fprintf(stderr, "%s: only one input file\n", progname);
    usage();
  }
#endif /* TWO_FILE_COMMANDLINE */

  /* Open the input file. */
  if (file_index < argc) {
    if ((fp = fopen(argv[file_index], READ_BINARY)) == NULL) {
      fprintf(stderr, "%s: can't open %s for reading\n", progname, argv[file_index]);
      exit(EXIT_FAILURE);
    }
  } else {
    /* default input file is stdin */
    fp = read_stdin();
  }

#ifdef PROGRESS_REPORT
  start_progress_monitor((j_common_ptr) &dstinfo, &progress);
#endif

  /* Specify data source for decompression */
  jpeg_stdio_src(&srcinfo, fp);

  /* Enable saving of extra markers that we want to copy */
  jcopy_markers_setup(&srcinfo, copyoption);

  /* Read file header */
  (void) jpeg_read_header(&srcinfo, TRUE);

  /* Adjust default decompression parameters */
  if (scaleoption != NULL)
    if (sscanf(scaleoption, "%u/%u",
	&srcinfo.scale_num, &srcinfo.scale_denom) < 1)
      usage();

  /* Any space needed by a transform option must be requested before
   * jpeg_read_coefficients so that memory allocation will be done right.
   */
#if TRANSFORMS_SUPPORTED
  /* Fail right away if -perfect is given and transformation is not perfect.
   */
  if (!jtransform_request_workspace(&srcinfo, &transformoption)) {
    fprintf(stderr, "%s: transformation is not perfect\n", progname);
    exit(EXIT_FAILURE);
  }
#endif

  /* Read source file as DCT coefficients */
  src_coef_arrays = jpeg_read_coefficients(&srcinfo);

  /* Initialize destination compression parameters from source values */
  jpeg_copy_critical_parameters(&srcinfo, &dstinfo);

  /* Adjust destination parameters if required by transform options;
   * also find out which set of coefficient arrays will hold the output.
   */
#if TRANSFORMS_SUPPORTED
  dst_coef_arrays = jtransform_adjust_parameters(&srcinfo, &dstinfo,
						 src_coef_arrays,