www.pudn.com > jpegsr6b.zip > cjpeg.c
/* * cjpeg.c * * Copyright (C) 1991-1998, 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 command-line 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. * To simplify script writing, the "-outfile" switch is provided. The syntax * cjpeg [options] -outfile outputfile inputfile * works regardless of which command line style is used. */ #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */ #include "jversion.h" /* for version message */ #ifdef USE_CCOMMAND /* command-line reader for Macintosh */ #ifdef __MWERKS__ #include/* Metrowerks needs this */ #include /* ... and this */ #endif #ifdef THINK_C #include /* Think declares it here */ #endif #endif /* Create the add-on message string table. */ #define JMESSAGE(code,string) string , static const char * const cdjpeg_message_table[] = { #include "cderror.h" NULL }; /* * 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 may 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. * Looking at additional bytes would require one of these approaches: * 1) assume we can fseek() the input file (fails for piped input); * 2) assume we can push back more than one character (works in * some C implementations, but unportable); * 3) provide our own buffering (breaks input readers that want to use * stdio directly, such as the RLE library); * or 4) don't put back the data, and modify the input_init methods to assume * they start reading after the start of file (also breaks RLE library). * #1 is attractive for MS-DOS but is untenable on Unix. * * The most portable solution for file types that can't be identified by their * first byte is to make the user tell us what they are. This is also the * only approach for "raw" file types that contain only arbitrary values. * We presently apply this method for Targa files. Most of the time Targa * files start with 0x00, so we recognize that case. Potentially, however, * a Targa file could start with any byte value (byte 0 is the length of the * seldom-used ID field), so we provide a switch to force Targa input mode. */ static boolean is_targa; /* records user -targa switch */ LOCAL(cjpeg_source_ptr) select_file_type (j_compress_ptr cinfo, FILE * infile) { int c; if (is_targa) { #ifdef TARGA_SUPPORTED return jinit_read_targa(cinfo); #else ERREXIT(cinfo, JERR_TGA_NOTCOMP); #endif } if ((c = getc(infile)) == EOF) ERREXIT(cinfo, JERR_INPUT_EMPTY); if (ungetc(c, infile) == EOF) ERREXIT(cinfo, JERR_UNGETC_FAILED); switch (c) { #ifdef BMP_SUPPORTED case 'B': return jinit_read_bmp(cinfo); #endif #ifdef GIF_SUPPORTED case 'G': return jinit_read_gif(cinfo); #endif #ifdef PPM_SUPPORTED case 'P': return jinit_read_ppm(cinfo); #endif #ifdef RLE_SUPPORTED case 'R': return jinit_read_rle(cinfo); #endif #ifdef TARGA_SUPPORTED case 0x00: return jinit_read_targa(cinfo); #endif default: ERREXIT(cinfo, JERR_UNKNOWN_FORMAT); break; } return NULL; /* suppress compiler warnings */ } /* * 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 */ 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, " -quality N Compression quality (0..100; 5-95 is useful range)\n"); fprintf(stderr, " -grayscale Create monochrome JPEG file\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 #ifdef TARGA_SUPPORTED fprintf(stderr, " -targa Input file is Targa format (usually not needed)\n"); #endif fprintf(stderr, "Switches for advanced users:\n"); #ifdef DCT_ISLOW_SUPPORTED fprintf(stderr, " -dct int Use integer DCT method%s\n", (JDCT_DEFAULT == JDCT_ISLOW ? " (default)" : "")); #endif #ifdef DCT_IFAST_SUPPORTED fprintf(stderr, " -dct fast Use fast integer DCT (less accurate)%s\n", (JDCT_DEFAULT == JDCT_IFAST ? " (default)" : "")); #endif #ifdef DCT_FLOAT_SUPPORTED fprintf(stderr, " -dct float Use floating-point DCT method%s\n", (JDCT_DEFAULT == JDCT_FLOAT ? " (default)" : "")); #endif fprintf(stderr, " -restart N Set restart interval in rows, or in blocks with B\n"); #ifdef INPUT_SMOOTHING_SUPPORTED fprintf(stderr, " -smooth N Smooth dithered input (N=1..100 is strength)\n"); #endif 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_ARITH_CODING_SUPPORTED fprintf(stderr, " -arithmetic Use arithmetic coding\n"); #endif fprintf(stderr, " -baseline Force baseline quantization tables\n"); fprintf(stderr, " -qtables file Use quantization tables given in file\n"); fprintf(stderr, " -qslots N[,...] Set component quantization tables\n"); fprintf(stderr, " -sample HxV[,...] Set component sampling factors\n"); #ifdef C_MULTISCAN_FILES_SUPPORTED fprintf(stderr, " -scans file Create multi-scan JPEG per script file\n"); #endif exit(EXIT_FAILURE); } 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; int quality; /* -quality parameter */ int q_scale_factor; /* scaling percentage for -qtables */ boolean force_baseline; boolean simple_progressive; char * qtablefile = NULL; /* saves -qtables filename if any */ char * qslotsarg = NULL; /* saves -qslots parm if any */ char * samplearg = NULL; /* saves -sample parm if any */ char * scansarg = NULL; /* saves -scans parm if any */ /* Set up default JPEG parameters. */ /* Note that default -quality level need not, and does not, * match the default scaling for an explicit -qtables argument. */ quality = 75; /* default -quality value */ q_scale_factor = 100; /* default to no scaling for -qtables */ force_baseline = FALSE; /* by default, allow 16-bit quantizers */ simple_progressive = FALSE; is_targa = FALSE; outfilename = NULL; 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, "baseline", 1)) { /* Force baseline-compatible output (8-bit quantizer values). */ force_baseline = TRUE; } else if (keymatch(arg, "dct", 2)) { /* Select DCT algorithm. */ if (++argn >= argc) /* advance to next argument */ usage(); if (keymatch(argv[argn], "int", 1)) { cinfo->dct_method = JDCT_ISLOW; } else if (keymatch(argv[argn], "fast", 2)) { cinfo->dct_method = JDCT_IFAST; } else if (keymatch(argv[argn], "float", 2)) { cinfo->dct_method = JDCT_FLOAT; } else usage(); } 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, "Independent JPEG Group's CJPEG, version %s\n%s\n", JVERSION, JCOPYRIGHT); printed_version = TRUE; } cinfo->err->trace_level++; } else if (keymatch(arg, "grayscale", 2) || keymatch(arg, "greyscale",2)) { /* Force a monochrome JPEG file to be generated. */ jpeg_set_colorspace(cinfo, JCS_GRAYSCALE); } 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, "progressive", 1)) { /* 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, "quality", 1)) { /* Quality factor (quantization table scaling factor). */ if (++argn >= argc) /* advance to next argument */ usage(); if (sscanf(argv[argn], "%d", &quality) != 1) usage(); /* Change scale factor in case -qtables is present. */ q_scale_factor = jpeg_quality_scaling(quality); } else if (keymatch(arg, "qslots", 2)) { /* Quantization table slot numbers. */ if (++argn >= argc) /* advance to next argument */ usage(); qslotsarg = argv[argn]; /* Must delay setting qslots until after we have processed any * colorspace-determining switches, since jpeg_set_colorspace sets * default quant table numbers. */ } else if (keymatch(arg, "qtables", 2)) { /* Quantization tables fetched from file. */ if (++argn >= argc) /* advance to next argument */ usage(); qtablefile = argv[argn]; /* We postpone actually reading the file in case -quality comes later. */ } 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, "sample", 2)) { /* Set sampling factors. */ if (++argn >= argc) /* advance to next argument */ usage(); samplearg = argv[argn]; /* Must delay setting sample factors until after we have processed any * colorspace-determining switches, since jpeg_set_colorspace sets * default sampling factors. */ } else if (keymatch(arg, "scans", 2)) { /* 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, "smooth", 2)) { /* Set input smoothing factor. */ int val; if (++argn >= argc) /* advance to next argument */ usage(); if (sscanf(argv[argn], "%d", &val) != 1) usage(); if (val < 0 || val > 100) usage(); cinfo->smoothing_factor = val; } else if (keymatch(arg, "targa", 1)) { /* Input file is Targa format. */ is_targa = TRUE; } else { usage(); /* bogus switch */ } } /* Post-switch-scanning cleanup */ if (for_real) { /* Set quantization tables for selected quality. */ /* Some or all may be overridden if -qtables is present. */ jpeg_set_quality(cinfo, quality, force_baseline); if (qtablefile != NULL) /* process -qtables if it was present */ if (! read_quant_tables(cinfo, qtablefile, q_scale_factor, force_baseline)) usage(); if (qslotsarg != NULL) /* process -qslots if it was present */ if (! set_quant_slots(cinfo, qslotsarg)) usage(); if (samplearg != NULL) /* process -sample if it was present */ if (! set_sample_factors(cinfo, samplearg)) usage(); #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_compress_struct cinfo; struct jpeg_error_mgr jerr; #ifdef PROGRESS_REPORT struct cdjpeg_progress_mgr progress; #endif int file_index; cjpeg_source_ptr src_mgr; FILE * input_file; FILE * output_file; JDIMENSION num_scanlines; /* On Mac, fetch a command line. */ #ifdef USE_CCOMMAND argc = ccommand(&argv); #endif progname = argv[0]; if (progname == NULL || progname[0] == 0) progname = "cjpeg"; /* in case C library doesn't provide it */ /* Initialize the JPEG compression object with default error handling. */ cinfo.err = jpeg_std_error(&jerr); jpeg_create_compress(&cinfo); /* Add some application-specific error messages (from cderror.h) */ jerr.addon_message_table = cdjpeg_message_table; jerr.first_addon_message = JMSG_FIRSTADDONCODE; jerr.last_addon_message = JMSG_LASTADDONCODE; /* Now safe to enable signal catcher. */ #ifdef NEED_SIGNAL_CATCHER enable_signal_catcher((j_common_ptr) &cinfo); #endif /* Initialize JPEG parameters. * Much of this may be overridden later. * In particular, we don't yet know the input file's color space, * but we need to provide some value for jpeg_set_defaults() to work. */ cinfo.in_color_space = JCS_RGB; /* arbitrary guess */ jpeg_set_defaults(&cinfo); /* Scan command line to find file names. * It is convenient to use just one switch-parsing routine, but the switch * values read here are ignored; we will rescan the switches after opening * the input file. */ file_index = parse_switches(&cinfo, argc, argv, 0, FALSE); #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 ((input_file = fopen(argv[file_index], READ_BINARY)) == NULL) { fprintf(stderr, "%s: can't open %s\n", progname, argv[file_index]); exit(EXIT_FAILURE); } } else { /* default input file is stdin */ input_file = read_stdin(); } /* Open the output file. */ if (outfilename != NULL) { if ((output_file = fopen(outfilename, WRITE_BINARY)) == NULL) { fprintf(stderr, "%s: can't open %s\n", progname, outfilename); exit(EXIT_FAILURE); } } else { /* default output file is stdout */ output_file = write_stdout(); } #ifdef PROGRESS_REPORT start_progress_monitor((j_common_ptr) &cinfo, &progress); #endif /* Figure out the input file format, and set up to read it. */ src_mgr = select_file_type(&cinfo, input_file); src_mgr->input_file = input_file; /* Read the input file header to obtain file size & colorspace. */ (*src_mgr->start_input) (&cinfo, src_mgr); /* Now that we know input colorspace, fix colorspace-dependent defaults */ jpeg_default_colorspace(&cinfo); /* Adjust default compression parameters by re-parsing the options */ file_index = parse_switches(&cinfo, argc, argv, 0, TRUE); /* Specify data destination for compression */ jpeg_stdio_dest(&cinfo, output_file); /* Start compressor */ jpeg_start_compress(&cinfo, TRUE); /* Process data */ while (cinfo.next_scanline < cinfo.image_height) { num_scanlines = (*src_mgr->get_pixel_rows) (&cinfo, src_mgr); (void) jpeg_write_scanlines(&cinfo, src_mgr->buffer, num_scanlines); } /* Finish compression and release memory */ (*src_mgr->finish_input) (&cinfo, src_mgr); jpeg_finish_compress(&cinfo); jpeg_destroy_compress(&cinfo); /* Close files, if we opened them */ if (input_file != stdin) fclose(input_file); if (output_file != stdout) fclose(output_file); #ifdef PROGRESS_REPORT end_progress_monitor((j_common_ptr) &cinfo); #endif /* All done. */ exit(jerr.num_warnings ? EXIT_WARNING : EXIT_SUCCESS); return 0; /* suppress no-return-value warnings */ }