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Diffstat (limited to 'jdmain.c')
| -rw-r--r-- | jdmain.c | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/jdmain.c b/jdmain.c new file mode 100644 index 0000000..109d124 --- /dev/null +++ b/jdmain.c @@ -0,0 +1,289 @@ +/* + * 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); +} |