jpegtran.c - platform/external/libjpeg-turbo - Gitiles

 /*
  * jpegtran.c
  *
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1995-2010, Thomas G. Lane, Guido Vollbeding.
  * libjpeg-turbo Modifications:
  * Copyright (C) 2010, D. R. Commander.
  * 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 */
 #include "jconfigint.h"

 #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 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
 #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;
   copyoption = JCOPYOPT_DEFAULT;
   transformoption.transform = JXFORM_NONE;
   transformoption.perfect = FALSE;
   transformoption.trim = FALSE;
   transformoption.force_grayscale = FALSE;
   transformoption.crop = FALSE;
   transformoption.slow_hflip = 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, "%s version %s (build %s)\n",
                 PACKAGE_NAME, VERSION, BUILD);
         fprintf(stderr, "%s\n\n", JCOPYRIGHT);
         fprintf(stderr, "Emulating The Independent JPEG Group's software, version %s\n\n",
                 JVERSION);
         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, "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);

   /* 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);

   /* 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 */
 }
	/*
	* jpegtran.c
	*
	* This file was part of the Independent JPEG Group's software:
	* Copyright (C) 1995-2010, Thomas G. Lane, Guido Vollbeding.
	* libjpeg-turbo Modifications:
	* Copyright (C) 2010, D. R. Commander.
	* 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 */
	#include "jconfigint.h"

	#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 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
	#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;
	copyoption = JCOPYOPT_DEFAULT;
	transformoption.transform = JXFORM_NONE;
	transformoption.perfect = FALSE;
	transformoption.trim = FALSE;
	transformoption.force_grayscale = FALSE;
	transformoption.crop = FALSE;
	transformoption.slow_hflip = 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, "%s version %s (build %s)\n",
	PACKAGE_NAME, VERSION, BUILD);
	fprintf(stderr, "%s\n\n", JCOPYRIGHT);
	fprintf(stderr, "Emulating The Independent JPEG Group's software, version %s\n\n",
	JVERSION);
	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, "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);

	/* 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);

	/* 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 */
	}