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