# dlib C++ Library - jpegtran.c

    /*
     * jpegtran.c
     *
     * Copyright (C) 1995-2011, Thomas G. Lane, Guido Vollbeding.
     * This file is part of the Independent JPEG Group's software.
     * For conditions of distribution and use, see the accompanying README file.
     *
     * This file contains a command-line user interface for JPEG transcoding.
     * It is very similar to cjpeg.c, and partly to djpeg.c, but provides
     * lossless transcoding between different JPEG file formats.  It also
     * provides some lossless and sort-of-lossless transformations of JPEG data.
     */

    #include "cdjpeg.h"		/* Common decls for cjpeg/djpeg applications */
    #include "transupp.h"		/* Support routines for jpegtran */
    #include "jversion.h"		/* for version message */

    #ifdef USE_CCOMMAND		/* command-line reader for Macintosh */
    #ifdef __MWERKS__
    #include <SIOUX.h>              /* Metrowerks needs this */
    #include <console.h>		/* ... and this */
    #endif
    #ifdef THINK_C
    #include <console.h>		/* Think declares it here */
    #endif
    #endif

    /*
     * Argument-parsing code.
     * The switch parser is designed to be useful with DOS-style command line
     * syntax, ie, intermixed switches and file names, where only the switches
     * to the left of a given file name affect processing of that file.
     * The main program in this file doesn't actually use this capability...
     */

    static const char * progname;	/* program name for error messages */
    static char * outfilename;	/* for -outfile switch */
    static char * scaleoption;	/* -scale switch */
    static JCOPY_OPTION copyoption;	/* -copy switch */
    static jpeg_transform_info transformoption; /* image transformation options */

    LOCAL(void)
    usage (void)
    /* complain about bad command line */
    {
      fprintf(stderr, "usage: %s [switches] ", progname);
    #ifdef TWO_FILE_COMMANDLINE
      fprintf(stderr, "inputfile outputfile\n");
    #else
      fprintf(stderr, "[inputfile]\n");
    #endif

      fprintf(stderr, "Switches (names may be abbreviated):\n");
      fprintf(stderr, "  -copy none     Copy no extra markers from source file\n");
      fprintf(stderr, "  -copy comments Copy only comment markers (default)\n");
      fprintf(stderr, "  -copy all      Copy all extra markers\n");
    #ifdef ENTROPY_OPT_SUPPORTED
      fprintf(stderr, "  -optimize      Optimize Huffman table (smaller file, but slow compression)\n");
    #endif
    #ifdef C_PROGRESSIVE_SUPPORTED
      fprintf(stderr, "  -progressive   Create progressive JPEG file\n");
    #endif
      fprintf(stderr, "Switches for modifying the image:\n");
    #if TRANSFORMS_SUPPORTED
      fprintf(stderr, "  -crop WxH+X+Y  Crop to a rectangular subarea\n");
      fprintf(stderr, "  -grayscale     Reduce to grayscale (omit color data)\n");
      fprintf(stderr, "  -flip [horizontal|vertical]  Mirror image (left-right or top-bottom)\n");
      fprintf(stderr, "  -perfect       Fail if there is non-transformable edge blocks\n");
      fprintf(stderr, "  -rotate [90|180|270]         Rotate image (degrees clockwise)\n");
    #endif
      fprintf(stderr, "  -scale M/N     Scale output image by fraction M/N, eg, 1/8\n");
    #if TRANSFORMS_SUPPORTED
      fprintf(stderr, "  -transpose     Transpose image\n");
      fprintf(stderr, "  -transverse    Transverse transpose image\n");
      fprintf(stderr, "  -trim          Drop non-transformable edge blocks\n");
    #endif
      fprintf(stderr, "Switches for advanced users:\n");
    #ifdef C_ARITH_CODING_SUPPORTED
      fprintf(stderr, "  -arithmetic    Use arithmetic coding\n");
    #endif
      fprintf(stderr, "  -restart N     Set restart interval in rows, or in blocks with B\n");
      fprintf(stderr, "  -maxmemory N   Maximum memory to use (in kbytes)\n");
      fprintf(stderr, "  -outfile name  Specify name for output file\n");
      fprintf(stderr, "  -verbose  or  -debug   Emit debug output\n");
      fprintf(stderr, "Switches for wizards:\n");
    #ifdef C_MULTISCAN_FILES_SUPPORTED
      fprintf(stderr, "  -scans file    Create multi-scan JPEG per script file\n");
    #endif
      exit(EXIT_FAILURE);
    }

    LOCAL(void)
    select_transform (JXFORM_CODE transform)
    /* Silly little routine to detect multiple transform options,
     * which we can't handle.
     */
    {
    #if TRANSFORMS_SUPPORTED
      if (transformoption.transform == JXFORM_NONE ||
          transformoption.transform == transform) {
        transformoption.transform = transform;
      } else {
        fprintf(stderr, "%s: can only do one image transformation at a time\n",
    	    progname);
        usage();
      }
    #else
      fprintf(stderr, "%s: sorry, image transformation was not compiled\n",
    	  progname);
      exit(EXIT_FAILURE);
    #endif
    }

    LOCAL(int)
    parse_switches (j_compress_ptr cinfo, int argc, char **argv,
    		int last_file_arg_seen, boolean for_real)
    /* Parse optional switches.
     * Returns argv[] index of first file-name argument (== argc if none).
     * Any file names with indexes <= last_file_arg_seen are ignored;
     * they have presumably been processed in a previous iteration.
     * (Pass 0 for last_file_arg_seen on the first or only iteration.)
     * for_real is FALSE on the first (dummy) pass; we may skip any expensive
     * processing.
     */
    {
      int argn;
      char * arg;
      boolean simple_progressive;
      char * scansarg = NULL;	/* saves -scans parm if any */

      /* Set up default JPEG parameters. */
      simple_progressive = FALSE;
      outfilename = NULL;
      scaleoption = NULL;
      copyoption = JCOPYOPT_DEFAULT;
      transformoption.transform = JXFORM_NONE;
      transformoption.perfect = FALSE;
      transformoption.trim = FALSE;
      transformoption.force_grayscale = FALSE;
      transformoption.crop = FALSE;
      cinfo->err->trace_level = 0;

      /* Scan command line options, adjust parameters */

      for (argn = 1; argn < argc; argn++) {
        arg = argv[argn];
        if (*arg != '-') {
          /* Not a switch, must be a file name argument */
          if (argn <= last_file_arg_seen) {
    	outfilename = NULL;	/* -outfile applies to just one input file */
    	continue;		/* ignore this name if previously processed */
          }
          break;			/* else done parsing switches */
        }
        arg++;			/* advance past switch marker character */

        if (keymatch(arg, "arithmetic", 1)) {
          /* Use arithmetic coding. */
    #ifdef C_ARITH_CODING_SUPPORTED
          cinfo->arith_code = TRUE;
    #else
          fprintf(stderr, "%s: sorry, arithmetic coding not supported\n",
    	      progname);
          exit(EXIT_FAILURE);
    #endif

        } else if (keymatch(arg, "copy", 2)) {
          /* Select which extra markers to copy. */
          if (++argn >= argc)	/* advance to next argument */
    	usage();
          if (keymatch(argv[argn], "none", 1)) {
    	copyoption = JCOPYOPT_NONE;
          } else if (keymatch(argv[argn], "comments", 1)) {
    	copyoption = JCOPYOPT_COMMENTS;
          } else if (keymatch(argv[argn], "all", 1)) {
    	copyoption = JCOPYOPT_ALL;
          } else
    	usage();

        } else if (keymatch(arg, "crop", 2)) {
          /* Perform lossless cropping. */
    #if TRANSFORMS_SUPPORTED
          if (++argn >= argc)	/* advance to next argument */
    	usage();
          if (! jtransform_parse_crop_spec(&transformoption, argv[argn])) {
    	fprintf(stderr, "%s: bogus -crop argument '%s'\n",
    		progname, argv[argn]);
    	exit(EXIT_FAILURE);
          }
    #else
          select_transform(JXFORM_NONE);	/* force an error */
    #endif

        } else if (keymatch(arg, "debug", 1) || keymatch(arg, "verbose", 1)) {
          /* Enable debug printouts. */
          /* On first -d, print version identification */
          static boolean printed_version = FALSE;

          if (! printed_version) {
    	fprintf(stderr, "Independent JPEG Group's JPEGTRAN, version %s\n%s\n",
    		JVERSION, JCOPYRIGHT);
    	printed_version = TRUE;
          }
          cinfo->err->trace_level++;

        } else if (keymatch(arg, "flip", 1)) {
          /* Mirror left-right or top-bottom. */
          if (++argn >= argc)	/* advance to next argument */
    	usage();
          if (keymatch(argv[argn], "horizontal", 1))
    	select_transform(JXFORM_FLIP_H);
          else if (keymatch(argv[argn], "vertical", 1))
    	select_transform(JXFORM_FLIP_V);
          else
    	usage();

        } else if (keymatch(arg, "grayscale", 1) || keymatch(arg, "greyscale",1)) {
          /* Force to grayscale. */
    #if TRANSFORMS_SUPPORTED
          transformoption.force_grayscale = TRUE;
    #else
          select_transform(JXFORM_NONE);	/* force an error */
    #endif

        } else if (keymatch(arg, "maxmemory", 3)) {
          /* Maximum memory in Kb (or Mb with 'm'). */
          long lval;
          char ch = 'x';

          if (++argn >= argc)	/* advance to next argument */
    	usage();
          if (sscanf(argv[argn], "%ld%c", &lval, &ch) < 1)
    	usage();
          if (ch == 'm' || ch == 'M')
    	lval *= 1000L;
          cinfo->mem->max_memory_to_use = lval * 1000L;

        } else if (keymatch(arg, "optimize", 1) || keymatch(arg, "optimise", 1)) {
          /* Enable entropy parm optimization. */
    #ifdef ENTROPY_OPT_SUPPORTED
          cinfo->optimize_coding = TRUE;
    #else
          fprintf(stderr, "%s: sorry, entropy optimization was not compiled\n",
    	      progname);
          exit(EXIT_FAILURE);
    #endif

        } else if (keymatch(arg, "outfile", 4)) {
          /* Set output file name. */
          if (++argn >= argc)	/* advance to next argument */
    	usage();
          outfilename = argv[argn];	/* save it away for later use */

        } else if (keymatch(arg, "perfect", 2)) {
          /* Fail if there is any partial edge MCUs that the transform can't
           * handle. */
          transformoption.perfect = TRUE;

        } else if (keymatch(arg, "progressive", 2)) {
          /* Select simple progressive mode. */
    #ifdef C_PROGRESSIVE_SUPPORTED
          simple_progressive = TRUE;
          /* We must postpone execution until num_components is known. */
    #else
          fprintf(stderr, "%s: sorry, progressive output was not compiled\n",
    	      progname);
          exit(EXIT_FAILURE);
    #endif

        } else if (keymatch(arg, "restart", 1)) {
          /* Restart interval in MCU rows (or in MCUs with 'b'). */
          long lval;
          char ch = 'x';

          if (++argn >= argc)	/* advance to next argument */
    	usage();
          if (sscanf(argv[argn], "%ld%c", &lval, &ch) < 1)
    	usage();
          if (lval < 0 || lval > 65535L)
    	usage();
          if (ch == 'b' || ch == 'B') {
    	cinfo->restart_interval = (unsigned int) lval;
    	cinfo->restart_in_rows = 0; /* else prior '-restart n' overrides me */
          } else {
    	cinfo->restart_in_rows = (int) lval;
    	/* restart_interval will be computed during startup */
          }

        } else if (keymatch(arg, "rotate", 2)) {
          /* Rotate 90, 180, or 270 degrees (measured clockwise). */
          if (++argn >= argc)	/* advance to next argument */
    	usage();
          if (keymatch(argv[argn], "90", 2))
    	select_transform(JXFORM_ROT_90);
          else if (keymatch(argv[argn], "180", 3))
    	select_transform(JXFORM_ROT_180);
          else if (keymatch(argv[argn], "270", 3))
    	select_transform(JXFORM_ROT_270);
          else
    	usage();

        } else if (keymatch(arg, "scale", 4)) {
          /* Scale the output image by a fraction M/N. */
          if (++argn >= argc)	/* advance to next argument */
    	usage();
          scaleoption = argv[argn];
          /* We must postpone processing until decompression startup. */

        } else if (keymatch(arg, "scans", 1)) {
          /* Set scan script. */
    #ifdef C_MULTISCAN_FILES_SUPPORTED
          if (++argn >= argc)	/* advance to next argument */
    	usage();
          scansarg = argv[argn];
          /* We must postpone reading the file in case -progressive appears. */
    #else
          fprintf(stderr, "%s: sorry, multi-scan output was not compiled\n",
    	      progname);
          exit(EXIT_FAILURE);
    #endif

        } else if (keymatch(arg, "transpose", 1)) {
          /* Transpose (across UL-to-LR axis). */
          select_transform(JXFORM_TRANSPOSE);

        } else if (keymatch(arg, "transverse", 6)) {
          /* Transverse transpose (across UR-to-LL axis). */
          select_transform(JXFORM_TRANSVERSE);

        } else if (keymatch(arg, "trim", 3)) {
          /* Trim off any partial edge MCUs that the transform can't handle. */
          transformoption.trim = TRUE;

        } else {
          usage();			/* bogus switch */
        }
      }

      /* Post-switch-scanning cleanup */

      if (for_real) {

    #ifdef C_PROGRESSIVE_SUPPORTED
        if (simple_progressive)	/* process -progressive; -scans can override */
          jpeg_simple_progression(cinfo);
    #endif

    #ifdef C_MULTISCAN_FILES_SUPPORTED
        if (scansarg != NULL)	/* process -scans if it was present */
          if (! read_scan_script(cinfo, scansarg))
    	usage();
    #endif
      }

      return argn;			/* return index of next arg (file name) */
    }

    /*
     * The main program.
     */

    int
    main (int argc, char **argv)
    {
      struct jpeg_decompress_struct srcinfo;
      struct jpeg_compress_struct dstinfo;
      struct jpeg_error_mgr jsrcerr, jdsterr;
    #ifdef PROGRESS_REPORT
      struct cdjpeg_progress_mgr progress;
    #endif
      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, "%d/%d",
    	&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,
    						 &transformoption);
    #else
      dst_coef_arrays = src_coef_arrays;
    #endif

      /* Close input file, if we opened it.
       * Note: we assume that jpeg_read_coefficients consumed all input
       * until JPEG_REACHED_EOI, and that jpeg_finish_decompress will
       * only consume more while (! cinfo->inputctl->eoi_reached).
       * We cannot call jpeg_finish_decompress here since we still need the
       * virtual arrays allocated from the source object for processing.
       */
      if (fp != stdin)
        fclose(fp);

      /* Open the output file. */
      if (outfilename != NULL) {
        if ((fp = fopen(outfilename, WRITE_BINARY)) == NULL) {
          fprintf(stderr, "%s: can't open %s for writing\n", progname, outfilename);
          exit(EXIT_FAILURE);
        }
      } else {
        /* default output file is stdout */
        fp = write_stdout();
      }

      /* Adjust default compression parameters by re-parsing the options */
      file_index = parse_switches(&dstinfo, argc, argv, 0, TRUE);

      /* Specify data destination for compression */
      jpeg_stdio_dest(&dstinfo, fp);

      /* Start compressor (note no image data is actually written here) */
      jpeg_write_coefficients(&dstinfo, dst_coef_arrays);

      /* Copy to the output file any extra markers that we want to preserve */
      jcopy_markers_execute(&srcinfo, &dstinfo, copyoption);

      /* Execute image transformation, if any */
    #if TRANSFORMS_SUPPORTED
      jtransform_execute_transformation(&srcinfo, &dstinfo,
    				    src_coef_arrays,
    				    &transformoption);
    #endif

      /* Finish compression and release memory */
      jpeg_finish_compress(&dstinfo);
      jpeg_destroy_compress(&dstinfo);
      (void) jpeg_finish_decompress(&srcinfo);
      jpeg_destroy_decompress(&srcinfo);

      /* Close output file, if we opened it */
      if (fp != stdout)
        fclose(fp);

    #ifdef PROGRESS_REPORT
      end_progress_monitor((j_common_ptr) &dstinfo);
    #endif

      /* All done. */
      exit(jsrcerr.num_warnings + jdsterr.num_warnings ?EXIT_WARNING:EXIT_SUCCESS);
      return 0;			/* suppress no-return-value warnings */
    }