/* * djpeg.c * * This file was part of the Independent JPEG Group's software: * Copyright (C) 1991-1997, Thomas G. Lane. * Modified 2013 by Guido Vollbeding. * libjpeg-turbo Modifications: * Copyright (C) 2010-2011, 2013-2017, D. R. Commander. * Copyright (C) 2015, Google, Inc. * For conditions of distribution and use, see the accompanying README.ijg * file. * * This file contains a command-line 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. * To simplify script writing, the "-outfile" switch is provided. The syntax * djpeg [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 */ #include "jconfigint.h" #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare free() */ extern void free(void *ptr); #endif #include <ctype.h> /* to declare isprint() */ #ifdef USE_CCOMMAND /* command-line reader for Macintosh */ #ifdef __MWERKS__ #include <SIOUX.h> /* Metrowerks needs this */ #include <console.h> /* ... and this */ #endif #ifdef THINK_C #include <console.h> /* 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 list defines the known output image formats * (not all of which need be supported by a given version). * You can change the default output format by defining DEFAULT_FMT; * indeed, you had better do so if you undefine PPM_SUPPORTED. */ typedef enum { FMT_BMP, /* BMP format (Windows flavor) */ FMT_GIF, /* GIF format */ FMT_OS2, /* BMP format (OS/2 flavor) */ FMT_PPM, /* PPM/PGM (PBMPLUS formats) */ FMT_RLE, /* RLE format */ FMT_TARGA, /* Targa format */ FMT_TIFF /* TIFF format */ } IMAGE_FORMATS; #ifndef DEFAULT_FMT /* so can override from CFLAGS in Makefile */ #define DEFAULT_FMT FMT_PPM #endif static IMAGE_FORMATS requested_fmt; /* * 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 *icc_filename; /* for -icc switch */ static char *outfilename; /* for -outfile switch */ boolean memsrc; /* for -memsrc switch */ boolean skip, crop; JDIMENSION skip_start, skip_end; JDIMENSION crop_x, crop_y, crop_width, crop_height; #define INPUT_BUF_SIZE 4096 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, " -colors N Reduce image to no more than N colors\n"); fprintf(stderr, " -fast Fast, low-quality processing\n"); fprintf(stderr, " -grayscale Force grayscale output\n"); fprintf(stderr, " -rgb Force RGB output\n"); fprintf(stderr, " -rgb565 Force RGB565 output\n"); #ifdef IDCT_SCALING_SUPPORTED fprintf(stderr, " -scale M/N Scale output image by fraction M/N, eg, 1/8\n"); #endif #ifdef BMP_SUPPORTED fprintf(stderr, " -bmp Select BMP output format (Windows style)%s\n", (DEFAULT_FMT == FMT_BMP ? " (default)" : "")); #endif #ifdef GIF_SUPPORTED fprintf(stderr, " -gif Select GIF output format%s\n", (DEFAULT_FMT == FMT_GIF ? " (default)" : "")); #endif #ifdef BMP_SUPPORTED fprintf(stderr, " -os2 Select BMP output format (OS/2 style)%s\n", (DEFAULT_FMT == FMT_OS2 ? " (default)" : "")); #endif #ifdef PPM_SUPPORTED fprintf(stderr, " -pnm Select PBMPLUS (PPM/PGM) output format%s\n", (DEFAULT_FMT == FMT_PPM ? " (default)" : "")); #endif #ifdef RLE_SUPPORTED fprintf(stderr, " -rle Select Utah RLE output format%s\n", (DEFAULT_FMT == FMT_RLE ? " (default)" : "")); #endif #ifdef TARGA_SUPPORTED fprintf(stderr, " -targa Select Targa output format%s\n", (DEFAULT_FMT == FMT_TARGA ? " (default)" : "")); #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, " -dither fs Use F-S dithering (default)\n"); fprintf(stderr, " -dither none Don't use dithering in quantization\n"); fprintf(stderr, " -dither ordered Use ordered dither (medium speed, quality)\n"); fprintf(stderr, " -icc FILE Extract ICC profile to FILE\n"); #ifdef QUANT_2PASS_SUPPORTED fprintf(stderr, " -map FILE Map to colors used in named image file\n"); #endif fprintf(stderr, " -nosmooth Don't use high-quality upsampling\n"); #ifdef QUANT_1PASS_SUPPORTED fprintf(stderr, " -onepass Use 1-pass quantization (fast, low quality)\n"); #endif fprintf(stderr, " -maxmemory N Maximum memory to use (in kbytes)\n"); fprintf(stderr, " -outfile name Specify name for output file\n"); #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED) fprintf(stderr, " -memsrc Load input file into memory before decompressing\n"); #endif fprintf(stderr, " -skip Y0,Y1 Decompress all rows except those between Y0 and Y1 (inclusive)\n"); fprintf(stderr, " -crop WxH+X+Y Decompress only a rectangular subregion of the image\n"); fprintf(stderr, " [requires PBMPLUS (PPM/PGM), GIF, or Targa output format]\n"); fprintf(stderr, " -verbose or -debug Emit debug output\n"); fprintf(stderr, " -version Print version information and exit\n"); exit(EXIT_FAILURE); } LOCAL(int) parse_switches(j_decompress_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; /* Set up default JPEG parameters. */ requested_fmt = DEFAULT_FMT; /* set default output file format */ icc_filename = NULL; outfilename = NULL; memsrc = FALSE; skip = FALSE; crop = FALSE; 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, "bmp", 1)) { /* BMP output format. */ requested_fmt = FMT_BMP; } else if (keymatch(arg, "colors", 1) || keymatch(arg, "colours", 1) || keymatch(arg, "quantize", 1) || keymatch(arg, "quantise", 1)) { /* Do color quantization. */ int val; if (++argn >= argc) /* advance to next argument */ usage(); if (sscanf(argv[argn], "%d", &val) != 1) usage(); cinfo->desired_number_of_colors = val; cinfo->quantize_colors = TRUE; } else if (keymatch(arg, "dct", 2)) { /* Select IDCT 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, "dither", 2)) { /* Select dithering algorithm. */ if (++argn >= argc) /* advance to next argument */ usage(); if (keymatch(argv[argn], "fs", 2)) { cinfo->dither_mode = JDITHER_FS; } else if (keymatch(argv[argn], "none", 2)) { cinfo->dither_mode = JDITHER_NONE; } else if (keymatch(argv[argn], "ordered", 2)) { cinfo->dither_mode = JDITHER_ORDERED; } 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, "%s version %s (build %s)\n", PACKAGE_NAME, VERSION, BUILD); fprintf(stderr, "%s\n\n", JCOPYRIGHT); fprintf(stderr, "Emulating The Independent JPEG Group's software, version %s\n\n", JVERSION); printed_version = TRUE; } cinfo->err->trace_level++; } else if (keymatch(arg, "version", 4)) { fprintf(stderr, "%s version %s (build %s)\n", PACKAGE_NAME, VERSION, BUILD); exit(EXIT_SUCCESS); } else if (keymatch(arg, "fast", 1)) { /* Select recommended processing options for quick-and-dirty output. */ cinfo->two_pass_quantize = FALSE; cinfo->dither_mode = JDITHER_ORDERED; if (!cinfo->quantize_colors) /* don't override an earlier -colors */ cinfo->desired_number_of_colors = 216; cinfo->dct_method = JDCT_FASTEST; cinfo->do_fancy_upsampling = FALSE; } else if (keymatch(arg, "gif", 1)) { /* GIF output format. */ requested_fmt = FMT_GIF; } else if (keymatch(arg, "grayscale", 2) || keymatch(arg, "greyscale", 2)) { /* Force monochrome output. */ cinfo->out_color_space = JCS_GRAYSCALE; } else if (keymatch(arg, "rgb", 2)) { /* Force RGB output. */ cinfo->out_color_space = JCS_RGB; } else if (keymatch(arg, "rgb565", 2)) { /* Force RGB565 output. */ cinfo->out_color_space = JCS_RGB565; } else if (keymatch(arg, "icc", 1)) { /* Set ICC filename. */ if (++argn >= argc) /* advance to next argument */ usage(); icc_filename = argv[argn]; jpeg_save_markers(cinfo, JPEG_APP0 + 2, 0xFFFF); } else if (keymatch(arg, "map", 3)) { /* Quantize to a color map taken from an input file. */ if (++argn >= argc) /* advance to next argument */ usage(); if (for_real) { /* too expensive to do twice! */ #ifdef QUANT_2PASS_SUPPORTED /* otherwise can't quantize to supplied map */ FILE *mapfile; if ((mapfile = fopen(argv[argn], READ_BINARY)) == NULL) { fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]); exit(EXIT_FAILURE); } read_color_map(cinfo, mapfile); fclose(mapfile); cinfo->quantize_colors = TRUE; #else ERREXIT(cinfo, JERR_NOT_COMPILED); #endif } } 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, "nosmooth", 3)) { /* Suppress fancy upsampling */ cinfo->do_fancy_upsampling = FALSE; } else if (keymatch(arg, "onepass", 3)) { /* Use fast one-pass quantization. */ cinfo->two_pass_quantize = FALSE; } else if (keymatch(arg, "os2", 3)) { /* BMP output format (OS/2 flavor). */ requested_fmt = FMT_OS2; } 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, "memsrc", 2)) { /* Use in-memory source manager */ #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED) memsrc = TRUE; #else fprintf(stderr, "%s: sorry, in-memory source manager was not compiled in\n", progname); exit(EXIT_FAILURE); #endif } else if (keymatch(arg, "pnm", 1) || keymatch(arg, "ppm", 1)) { /* PPM/PGM output format. */ requested_fmt = FMT_PPM; } else if (keymatch(arg, "rle", 1)) { /* RLE output format. */ requested_fmt = FMT_RLE; } else if (keymatch(arg, "scale", 2)) { /* Scale the output image by a fraction M/N. */ if (++argn >= argc) /* advance to next argument */ usage(); if (sscanf(argv[argn], "%u/%u", &cinfo->scale_num, &cinfo->scale_denom) != 2) usage(); } else if (keymatch(arg, "skip", 2)) { if (++argn >= argc) usage(); if (sscanf(argv[argn], "%u,%u", &skip_start, &skip_end) != 2 || skip_start > skip_end) usage(); skip = TRUE; } else if (keymatch(arg, "crop", 2)) { char c; if (++argn >= argc) usage(); if (sscanf(argv[argn], "%u%c%u+%u+%u", &crop_width, &c, &crop_height, &crop_x, &crop_y) != 5 || (c != 'X' && c != 'x') || crop_width < 1 || crop_height < 1) usage(); crop = TRUE; } else if (keymatch(arg, "targa", 1)) { /* Targa output format. */ requested_fmt = FMT_TARGA; } else { usage(); /* bogus switch */ } } return argn; /* return index of next arg (file name) */ } /* * Marker processor for COM and interesting APPn markers. * This replaces the library's built-in processor, which just skips the marker. * We want to print out the marker as text, to the extent possible. * Note this code relies on a non-suspending data source. */ LOCAL(unsigned int) jpeg_getc(j_decompress_ptr cinfo) /* Read next byte */ { struct jpeg_source_mgr *datasrc = cinfo->src; if (datasrc->bytes_in_buffer == 0) { if (!(*datasrc->fill_input_buffer) (cinfo)) ERREXIT(cinfo, JERR_CANT_SUSPEND); } datasrc->bytes_in_buffer--; return GETJOCTET(*datasrc->next_input_byte++); } METHODDEF(boolean) print_text_marker(j_decompress_ptr cinfo) { boolean traceit = (cinfo->err->trace_level >= 1); long length; unsigned int ch; unsigned int lastch = 0; length = jpeg_getc(cinfo) << 8; length += jpeg_getc(cinfo); length -= 2; /* discount the length word itself */ if (traceit) { if (cinfo->unread_marker == JPEG_COM) fprintf(stderr, "Comment, length %ld:\n", (long)length); else /* assume it is an APPn otherwise */ fprintf(stderr, "APP%d, length %ld:\n", cinfo->unread_marker - JPEG_APP0, (long)length); } while (--length >= 0) { ch = jpeg_getc(cinfo); if (traceit) { /* Emit the character in a readable form. * Nonprintables are converted to \nnn form, * while \ is converted to \\. * Newlines in CR, CR/LF, or LF form will be printed as one newline. */ if (ch == '\r') { fprintf(stderr, "\n"); } else if (ch == '\n') { if (lastch != '\r') fprintf(stderr, "\n"); } else if (ch == '\\') { fprintf(stderr, "\\\\"); } else if (isprint(ch)) { putc(ch, stderr); } else { fprintf(stderr, "\\%03o", ch); } lastch = ch; } } if (traceit) fprintf(stderr, "\n"); return TRUE; } /* * The main program. */ int main(int argc, char **argv) { struct jpeg_decompress_struct cinfo; struct jpeg_error_mgr jerr; #ifdef PROGRESS_REPORT struct cdjpeg_progress_mgr progress; #endif int file_index; djpeg_dest_ptr dest_mgr = NULL; FILE *input_file; FILE *output_file; unsigned char *inbuffer = NULL; unsigned long insize = 0; 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 = "djpeg"; /* in case C library doesn't provide it */ /* Initialize the JPEG decompression object with default error handling. */ cinfo.err = jpeg_std_error(&jerr); jpeg_create_decompress(&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; /* Insert custom marker processor for COM and APP12. * APP12 is used by some digital camera makers for textual info, * so we provide the ability to display it as text. * If you like, additional APPn marker types can be selected for display, * but don't try to override APP0 or APP14 this way (see libjpeg.txt). */ jpeg_set_marker_processor(&cinfo, JPEG_COM, print_text_marker); jpeg_set_marker_processor(&cinfo, JPEG_APP0 + 12, print_text_marker); /* 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. * (Exception: tracing level set here controls verbosity for COM markers * found during jpeg_read_header...) */ 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 /* Specify data source for decompression */ #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED) if (memsrc) { size_t nbytes; do { inbuffer = (unsigned char *)realloc(inbuffer, insize + INPUT_BUF_SIZE); if (inbuffer == NULL) { fprintf(stderr, "%s: memory allocation failure\n", progname); exit(EXIT_FAILURE); } nbytes = JFREAD(input_file, &inbuffer[insize], INPUT_BUF_SIZE); if (nbytes < INPUT_BUF_SIZE && ferror(input_file)) { if (file_index < argc) fprintf(stderr, "%s: can't read from %s\n", progname, argv[file_index]); else fprintf(stderr, "%s: can't read from stdin\n", progname); } insize += (unsigned long)nbytes; } while (nbytes == INPUT_BUF_SIZE); fprintf(stderr, "Compressed size: %lu bytes\n", insize); jpeg_mem_src(&cinfo, inbuffer, insize); } else #endif jpeg_stdio_src(&cinfo, input_file); /* Read file header, set default decompression parameters */ (void)jpeg_read_header(&cinfo, TRUE); /* Adjust default decompression parameters by re-parsing the options */ file_index = parse_switches(&cinfo, argc, argv, 0, TRUE); /* Initialize the output module now to let it override any crucial * option settings (for instance, GIF wants to force color quantization). */ switch (requested_fmt) { #ifdef BMP_SUPPORTED case FMT_BMP: dest_mgr = jinit_write_bmp(&cinfo, FALSE, TRUE); break; case FMT_OS2: dest_mgr = jinit_write_bmp(&cinfo, TRUE, TRUE); break; #endif #ifdef GIF_SUPPORTED case FMT_GIF: dest_mgr = jinit_write_gif(&cinfo); break; #endif #ifdef PPM_SUPPORTED case FMT_PPM: dest_mgr = jinit_write_ppm(&cinfo); break; #endif #ifdef RLE_SUPPORTED case FMT_RLE: dest_mgr = jinit_write_rle(&cinfo); break; #endif #ifdef TARGA_SUPPORTED case FMT_TARGA: dest_mgr = jinit_write_targa(&cinfo); break; #endif default: ERREXIT(&cinfo, JERR_UNSUPPORTED_FORMAT); break; } dest_mgr->output_file = output_file; /* Start decompressor */ (void)jpeg_start_decompress(&cinfo); /* Skip rows */ if (skip) { JDIMENSION tmp; /* Check for valid skip_end. We cannot check this value until after * jpeg_start_decompress() is called. Note that we have already verified * that skip_start <= skip_end. */ if (skip_end > cinfo.output_height - 1) { fprintf(stderr, "%s: skip region exceeds image height %d\n", progname, cinfo.output_height); exit(EXIT_FAILURE); } /* Write output file header. This is a hack to ensure that the destination * manager creates an output image of the proper size. */ tmp = cinfo.output_height; cinfo.output_height -= (skip_end - skip_start + 1); (*dest_mgr->start_output) (&cinfo, dest_mgr); cinfo.output_height = tmp; /* Process data */ while (cinfo.output_scanline < skip_start) { num_scanlines = jpeg_read_scanlines(&cinfo, dest_mgr->buffer, dest_mgr->buffer_height); (*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines); } jpeg_skip_scanlines(&cinfo, skip_end - skip_start + 1); while (cinfo.output_scanline < cinfo.output_height) { num_scanlines = jpeg_read_scanlines(&cinfo, dest_mgr->buffer, dest_mgr->buffer_height); (*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines); } /* Decompress a subregion */ } else if (crop) { JDIMENSION tmp; /* Check for valid crop dimensions. We cannot check these values until * after jpeg_start_decompress() is called. */ if (crop_x + crop_width > cinfo.output_width || crop_y + crop_height > cinfo.output_height) { fprintf(stderr, "%s: crop dimensions exceed image dimensions %d x %d\n", progname, cinfo.output_width, cinfo.output_height); exit(EXIT_FAILURE); } jpeg_crop_scanline(&cinfo, &crop_x, &crop_width); if (dest_mgr->calc_buffer_dimensions) (*dest_mgr->calc_buffer_dimensions) (&cinfo, dest_mgr); else ERREXIT(&cinfo, JERR_UNSUPPORTED_FORMAT); /* Write output file header. This is a hack to ensure that the destination * manager creates an output image of the proper size. */ tmp = cinfo.output_height; cinfo.output_height = crop_height; (*dest_mgr->start_output) (&cinfo, dest_mgr); cinfo.output_height = tmp; /* Process data */ jpeg_skip_scanlines(&cinfo, crop_y); while (cinfo.output_scanline < crop_y + crop_height) { num_scanlines = jpeg_read_scanlines(&cinfo, dest_mgr->buffer, dest_mgr->buffer_height); (*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines); } jpeg_skip_scanlines(&cinfo, cinfo.output_height - crop_y - crop_height); /* Normal full-image decompress */ } else { /* Write output file header */ (*dest_mgr->start_output) (&cinfo, dest_mgr); /* Process data */ while (cinfo.output_scanline < cinfo.output_height) { num_scanlines = jpeg_read_scanlines(&cinfo, dest_mgr->buffer, dest_mgr->buffer_height); (*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines); } } #ifdef PROGRESS_REPORT /* Hack: count final pass as done in case finish_output does an extra pass. * The library won't have updated completed_passes. */ progress.pub.completed_passes = progress.pub.total_passes; #endif if (icc_filename != NULL) { FILE *icc_file; JOCTET *icc_profile; unsigned int icc_len; if ((icc_file = fopen(icc_filename, WRITE_BINARY)) == NULL) { fprintf(stderr, "%s: can't open %s\n", progname, icc_filename); exit(EXIT_FAILURE); } if (jpeg_read_icc_profile(&cinfo, &icc_profile, &icc_len)) { if (fwrite(icc_profile, icc_len, 1, icc_file) < 1) { fprintf(stderr, "%s: can't read ICC profile from %s\n", progname, icc_filename); free(icc_profile); fclose(icc_file); exit(EXIT_FAILURE); } free(icc_profile); fclose(icc_file); } else if (cinfo.err->msg_code != JWRN_BOGUS_ICC) fprintf(stderr, "%s: no ICC profile data in JPEG file\n", progname); } /* Finish decompression and release memory. * I must do it in this order because output module has allocated memory * of lifespan JPOOL_IMAGE; it needs to finish before releasing memory. */ (*dest_mgr->finish_output) (&cinfo, dest_mgr); (void)jpeg_finish_decompress(&cinfo); jpeg_destroy_decompress(&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 if (memsrc && inbuffer != NULL) free(inbuffer); /* All done. */ exit(jerr.num_warnings ? EXIT_WARNING : EXIT_SUCCESS); return 0; /* suppress no-return-value warnings */ }