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/*
* jdmain.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 decompressor.
* 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:
* djpeg [options] inputfile outputfile
* djpeg [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
typedef enum { /* defines known output image formats */
FMT_PPM, /* PPM/PGM (PBMPLUS formats) */
FMT_GIF, /* GIF format */
FMT_TIFF /* TIFF format */
} IMAGE_FORMATS;
static IMAGE_FORMATS requested_fmt;
/*
* This routine gets control after the input file header has been read.
* It must determine what output file format is to be written,
* and make any other decompression parameter changes that are desirable.
*/
METHODDEF void
d_ui_method_selection (decompress_info_ptr cinfo)
{
/* if grayscale or CMYK input, force similar output; */
/* else leave the output colorspace as set by options. */
if (cinfo->jpeg_color_space == CS_GRAYSCALE)
cinfo->out_color_space = CS_GRAYSCALE;
else if (cinfo->jpeg_color_space == CS_CMYK)
cinfo->out_color_space = CS_CMYK;
/* select output file format */
/* Note: jselwxxx routine may make additional parameter changes,
* such as forcing color quantization if it's a colormapped format.
*/
switch (requested_fmt) {
#ifdef GIF_SUPPORTED
case FMT_GIF:
jselwgif(cinfo);
break;
#endif
#ifdef PPM_SUPPORTED
case FMT_PPM:
jselwppm(cinfo);
break;
#endif
default:
ERREXIT(cinfo->emethods, "Unsupported output file format");
break;
}
}
/*
* Reload the input buffer after it's been emptied, and return the next byte.
* See the JGETC macro for calling conditions.
*
* This routine would need to be replaced if reading JPEG data from something
* other than a stdio stream.
*/
METHODDEF int
read_jpeg_data (decompress_info_ptr cinfo)
{
cinfo->bytes_in_buffer = fread(cinfo->input_buffer + MIN_UNGET,
1, JPEG_BUF_SIZE,
cinfo->input_file);
cinfo->next_input_byte = cinfo->input_buffer + MIN_UNGET;
if (cinfo->bytes_in_buffer <= 0)
ERREXIT(cinfo->emethods, "Unexpected EOF in JPEG file");
return JGETC(cinfo);
}
LOCAL void
usage (char * progname)
/* complain about bad command line */
{
fprintf(stderr, "usage: %s ", progname);
fprintf(stderr, "[-b] [-q colors] [-2] [-d] [-g] [-G]");
#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 decompress_info_struct cinfo;
struct decompress_methods_struct dc_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 = &dc_methods;
cinfo.emethods = &e_methods;
jselerror(&e_methods); /* error/trace message routines */
jselvirtmem(&e_methods); /* memory allocation routines */
dc_methods.d_ui_method_selection = d_ui_method_selection;
dc_methods.read_jpeg_data = read_jpeg_data;
/* Allocate memory for input buffer. */
cinfo.input_buffer = (char *) (*cinfo.emethods->alloc_small)
((size_t) (JPEG_BUF_SIZE + MIN_UNGET));
cinfo.bytes_in_buffer = 0; /* initialize buffer to empty */
/* 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;
cinfo.output_gamma = 1.0;
cinfo.quantize_colors = FALSE;
cinfo.two_pass_quantize = FALSE;
cinfo.use_dithering = FALSE;
cinfo.desired_number_of_colors = 256;
cinfo.do_block_smoothing = FALSE;
cinfo.do_pixel_smoothing = FALSE;
cinfo.out_color_space = CS_RGB;
cinfo.jpeg_color_space = CS_UNKNOWN;
/* setting any other value in jpeg_color_space overrides heuristics */
/* in jrdjfif.c ... */
/* You may wanta change the default output format; here's the place: */
#ifdef PPM_SUPPORTED
requested_fmt = FMT_PPM;
#else
requested_fmt = FMT_GIF;
#endif
/* Scan parameters */
while ((c = getopt(argc, argv, "bq:2DdgG")) != EOF)
switch (c) {
case 'b': /* Enable cross-block smoothing. */
cinfo.do_block_smoothing = TRUE;
break;
case 'q': /* Do color quantization. */
{ int val;
if (optarg == NULL)
usage(argv[0]);
if (sscanf(optarg, "%d", &val) != 1)
usage(argv[0]);
cinfo.desired_number_of_colors = val;
}
cinfo.quantize_colors = TRUE;
break;
case '2': /* Use two-pass quantization. */
cinfo.two_pass_quantize = TRUE;
break;
case 'D': /* Use dithering in color quantization. */
cinfo.use_dithering = TRUE;
break;
case 'd': /* Debugging. */
e_methods.trace_level++;
break;
case 'g': /* Force grayscale output. */
cinfo.out_color_space = CS_GRAYSCALE;
break;
case 'G': /* GIF output format. */
requested_fmt = FMT_GIF;
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 */
/* Set up to read a JFIF or baseline-JPEG file. */
/* A smarter UI would inspect the first few bytes of the input file */
/* to determine its type. */
#ifdef JFIF_SUPPORTED
jselrjfif(&cinfo);
#else
You shoulda defined JFIF_SUPPORTED. /* deliberate syntax error */
#endif
/* Do it to it! */
jpeg_decompress(&cinfo);
/* Release memory. */
(*cinfo.emethods->free_small) ((void *) cinfo.input_buffer);
#ifdef MEM_STATS
if (e_methods.trace_level > 0)
j_mem_stats();
#endif
/* All done. */
exit(0);
}
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