273 lines
7.2 KiB
C
273 lines
7.2 KiB
C
/*
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* jcmain.c
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*
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* Copyright (C) 1991, Thomas G. Lane.
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* This file is part of the Independent JPEG Group's software.
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* For conditions of distribution and use, see the accompanying README file.
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*
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* This file contains a trivial test user interface for the JPEG compressor.
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* It should work on any system with Unix- or MS-DOS-style command lines.
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*
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* Two different command line styles are permitted, depending on the
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* compile-time switch TWO_FILE_COMMANDLINE:
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* cjpeg [options] inputfile outputfile
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* cjpeg [options] [inputfile]
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* In the second style, output is always to standard output, which you'd
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* normally redirect to a file or pipe to some other program. Input is
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* either from a named file or from standard input (typically redirected).
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* The second style is convenient on Unix but is unhelpful on systems that
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* don't support pipes. Also, you MUST use the first style if your system
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* doesn't do binary I/O to stdin/stdout.
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*/
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#include "jinclude.h"
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#ifdef __STDC__
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#include <stdlib.h> /* to declare exit() */
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#endif
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#ifdef THINK_C
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#include <console.h> /* command-line reader for Macintosh */
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#endif
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#ifdef DONT_USE_B_MODE /* define mode parameters for fopen() */
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#define READ_BINARY "r"
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#define WRITE_BINARY "w"
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#else
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#define READ_BINARY "rb"
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#define WRITE_BINARY "wb"
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#endif
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/*
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* If your system has getopt(3), you can use your library version by
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* defining HAVE_GETOPT. By default, we use the PD 'egetopt'.
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*/
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#ifdef HAVE_GETOPT
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extern int getopt PP((int argc, char **argv, char *optstring));
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extern char * optarg;
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extern int optind;
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#else
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#include "egetopt.c"
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#define getopt(argc,argv,opt) egetopt(argc,argv,opt)
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#endif
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/*
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* This routine determines what format the input file is,
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* and selects the appropriate input-reading module.
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*
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* To determine which family of input formats the file belongs to,
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* we look only at the first byte of the file, since C does not
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* guarantee that more than one character can be pushed back with ungetc.
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* This is sufficient for the currently envisioned set of input formats.
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*
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* If you need to look at more than one character to select an input module,
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* you can either
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* 1) assume you can fseek() the input file (may fail for piped input);
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* 2) assume you can push back more than one character (works in
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* some C implementations, but unportable);
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* or 3) don't put back the data, and modify the various input_init
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* methods to assume they start reading after the start of file.
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*/
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LOCAL void
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select_file_type (compress_info_ptr cinfo)
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{
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int c;
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if ((c = getc(cinfo->input_file)) == EOF)
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ERREXIT(cinfo->emethods, "Empty input file");
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switch (c) {
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#ifdef GIF_SUPPORTED
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case 'G':
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jselrgif(cinfo);
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break;
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#endif
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#ifdef PPM_SUPPORTED
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case 'P':
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jselrppm(cinfo);
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break;
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#endif
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default:
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ERREXIT(cinfo->emethods, "Unsupported input file format");
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break;
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}
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if (ungetc(c, cinfo->input_file) == EOF)
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ERREXIT(cinfo->emethods, "ungetc failed");
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}
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/*
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* This routine gets control after the input file header has been read.
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* It must determine what output JPEG file format is to be written,
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* and make any other compression parameter changes that are desirable.
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*/
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METHODDEF void
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c_ui_method_selection (compress_info_ptr cinfo)
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{
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/* If the input is gray scale, generate a monochrome JPEG file. */
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if (cinfo->in_color_space == CS_GRAYSCALE)
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j_monochrome_default(cinfo);
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/* For now, always select JFIF output format. */
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#ifdef JFIF_SUPPORTED
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jselwjfif(cinfo);
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#else
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You shoulda defined JFIF_SUPPORTED. /* deliberate syntax error */
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#endif
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}
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LOCAL void
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usage (char * progname)
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/* complain about bad command line */
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{
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fprintf(stderr, "usage: %s ", progname);
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fprintf(stderr, "[-I] [-Q quality 0..100] [-a] [-o] [-d]");
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#ifdef TWO_FILE_COMMANDLINE
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fprintf(stderr, " inputfile outputfile\n");
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#else
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fprintf(stderr, " [inputfile]\n");
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#endif
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exit(2);
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}
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/*
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* The main program.
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*/
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GLOBAL void
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main (int argc, char **argv)
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{
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struct compress_info_struct cinfo;
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struct compress_methods_struct c_methods;
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struct external_methods_struct e_methods;
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int c;
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/* On Mac, fetch a command line. */
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#ifdef THINK_C
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argc = ccommand(&argv);
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#endif
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/* Initialize the system-dependent method pointers. */
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cinfo.methods = &c_methods;
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cinfo.emethods = &e_methods;
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jselerror(&e_methods); /* error/trace message routines */
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jselvirtmem(&e_methods); /* memory allocation routines */
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c_methods.c_ui_method_selection = c_ui_method_selection;
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/* Set up default input and output file references. */
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/* (These may be overridden below.) */
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cinfo.input_file = stdin;
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cinfo.output_file = stdout;
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/* Set up default parameters. */
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e_methods.trace_level = 0;
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j_default_compression(&cinfo, 75); /* default quality level */
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/* Scan parameters */
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while ((c = getopt(argc, argv, "IQ:aod")) != EOF)
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switch (c) {
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case 'I': /* Create noninterleaved file. */
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#ifdef MULTISCAN_FILES_SUPPORTED
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cinfo.interleave = FALSE;
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#else
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fprintf(stderr, "%s: sorry, multiple-scan support was not compiled\n",
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argv[0]);
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exit(2);
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#endif
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break;
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case 'Q': /* Quality factor. */
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{ int val;
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if (optarg == NULL)
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usage(argv[0]);
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if (sscanf(optarg, "%d", &val) != 1)
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usage(argv[0]);
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/* Note: for now, we leave force_baseline FALSE.
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* In a production user interface, probably should make it TRUE
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* unless overridden by a separate switch.
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*/
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j_set_quality(&cinfo, val, FALSE);
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}
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break;
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case 'a': /* Use arithmetic coding. */
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#ifdef ARITH_CODING_SUPPORTED
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cinfo.arith_code = TRUE;
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#else
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fprintf(stderr, "%s: sorry, arithmetic coding not supported\n",
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argv[0]);
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exit(2);
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#endif
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break;
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case 'o': /* Enable entropy parm optimization. */
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#ifdef ENTROPY_OPT_SUPPORTED
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cinfo.optimize_coding = TRUE;
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#else
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fprintf(stderr, "%s: sorry, entropy optimization was not compiled\n",
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argv[0]);
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exit(2);
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#endif
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break;
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case 'd': /* Debugging. */
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e_methods.trace_level++;
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break;
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case '?':
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default:
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usage(argv[0]);
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break;
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}
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/* Select the input and output files */
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#ifdef TWO_FILE_COMMANDLINE
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if (optind != argc-2) {
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fprintf(stderr, "%s: must name one input and one output file\n", argv[0]);
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usage(argv[0]);
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}
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if ((cinfo.input_file = fopen(argv[optind], READ_BINARY)) == NULL) {
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fprintf(stderr, "%s: can't open %s\n", argv[0], argv[optind]);
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exit(2);
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}
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if ((cinfo.output_file = fopen(argv[optind+1], WRITE_BINARY)) == NULL) {
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fprintf(stderr, "%s: can't open %s\n", argv[0], argv[optind+1]);
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exit(2);
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}
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#else /* not TWO_FILE_COMMANDLINE -- use Unix style */
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if (optind < argc-1) {
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fprintf(stderr, "%s: only one input file\n", argv[0]);
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usage(argv[0]);
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}
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if (optind < argc) {
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if ((cinfo.input_file = fopen(argv[optind], READ_BINARY)) == NULL) {
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fprintf(stderr, "%s: can't open %s\n", argv[0], argv[optind]);
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exit(2);
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}
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}
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#endif /* TWO_FILE_COMMANDLINE */
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/* Figure out the input file format, and set up to read it. */
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select_file_type(&cinfo);
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/* Do it to it! */
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jpeg_compress(&cinfo);
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/* Release memory. */
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j_free_defaults(&cinfo);
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#ifdef MEM_STATS
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if (e_methods.trace_level > 0)
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j_mem_stats();
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#endif
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/* All done. */
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exit(0);
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}
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