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Unified Diff: djpeg.c

Issue 1934113002: Update libjpeg_turbo to 1.4.90 from https://github.com/libjpeg-turbo/ (Closed) Base URL: https://chromium.googlesource.com/chromium/deps/libjpeg_turbo.git@master
Patch Set: Created 4 years, 8 months ago
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Index: djpeg.c
diff --git a/djpeg.c b/djpeg.c
index 237ed515190a4a71cdf34c39c89f478eb239fbe5..54cd525ede8a3fb19847f8eed035a5b18a97c72b 100644
--- a/djpeg.c
+++ b/djpeg.c
@@ -3,18 +3,20 @@
*
* 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, 2013-2015, D. R. Commander.
+ * Copyright (C) 2010-2011, 2013-2016, D. R. Commander.
* Copyright (C) 2015, Google, Inc.
- * For conditions of distribution and use, see the accompanying README file.
+ * 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]
+ * 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).
@@ -22,30 +24,31 @@
* 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
+ * 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 "config.h"
+#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
+#include "jversion.h" /* for version message */
+#include "jconfigint.h"
+#include "wrppm.h"
-#include <ctype.h> /* to declare isprint() */
+#include <ctype.h> /* to declare isprint() */
-#ifdef USE_CCOMMAND /* command-line reader for Macintosh */
+#ifdef USE_CCOMMAND /* command-line reader for Macintosh */
#ifdef __MWERKS__
#include <SIOUX.h> /* Metrowerks needs this */
-#include <console.h> /* ... and this */
+#include <console.h> /* ... and this */
#endif
#ifdef THINK_C
-#include <console.h> /* Think declares it here */
+#include <console.h> /* Think declares it here */
#endif
#endif
/* Create the add-on message string table. */
-#define JMESSAGE(code,string) string ,
+#define JMESSAGE(code,string) string ,
static const char * const cdjpeg_message_table[] = {
#include "cderror.h"
@@ -61,17 +64,17 @@ static const char * const cdjpeg_message_table[] = {
*/
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 */
+ 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
+#ifndef DEFAULT_FMT /* so can override from CFLAGS in Makefile */
+#define DEFAULT_FMT FMT_PPM
#endif
static IMAGE_FORMATS requested_fmt;
@@ -86,11 +89,12 @@ static IMAGE_FORMATS requested_fmt;
*/
-static const char * progname; /* program name for error messages */
-static char * outfilename; /* for -outfile switch */
-boolean memsrc; /* for -memsrc switch */
-boolean strip, skip;
-JDIMENSION startY, endY;
+static const char *progname; /* program name for error messages */
+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
@@ -116,40 +120,40 @@ usage (void)
#endif
#ifdef BMP_SUPPORTED
fprintf(stderr, " -bmp Select BMP output format (Windows style)%s\n",
- (DEFAULT_FMT == FMT_BMP ? " (default)" : ""));
+ (DEFAULT_FMT == FMT_BMP ? " (default)" : ""));
#endif
#ifdef GIF_SUPPORTED
fprintf(stderr, " -gif Select GIF output format%s\n",
- (DEFAULT_FMT == FMT_GIF ? " (default)" : ""));
+ (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)" : ""));
+ (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)" : ""));
+ (DEFAULT_FMT == FMT_PPM ? " (default)" : ""));
#endif
#ifdef RLE_SUPPORTED
fprintf(stderr, " -rle Select Utah RLE output format%s\n",
- (DEFAULT_FMT == FMT_RLE ? " (default)" : ""));
+ (DEFAULT_FMT == FMT_RLE ? " (default)" : ""));
#endif
#ifdef TARGA_SUPPORTED
fprintf(stderr, " -targa Select Targa output format%s\n",
- (DEFAULT_FMT == FMT_TARGA ? " (default)" : ""));
+ (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)" : ""));
+ (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)" : ""));
+ (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)" : ""));
+ (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");
@@ -167,16 +171,17 @@ usage (void)
fprintf(stderr, " -memsrc Load input file into memory before decompressing\n");
#endif
- fprintf(stderr, " -skip Y0,Y1 Decode all rows except those between Y0 and Y1 (inclusive)\n");
- fprintf(stderr, " -strip Y0,Y1 Decode only rows between Y0 and Y1 (inclusive)\n");
+ 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, " -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)
+ 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;
@@ -187,14 +192,14 @@ parse_switches (j_decompress_ptr cinfo, int argc, char **argv,
*/
{
int argn;
- char * arg;
+ char *arg;
/* Set up default JPEG parameters. */
- requested_fmt = DEFAULT_FMT; /* set default output file format */
+ requested_fmt = DEFAULT_FMT; /* set default output file format */
outfilename = NULL;
memsrc = FALSE;
- strip = FALSE;
skip = FALSE;
+ crop = FALSE;
cinfo->err->trace_level = 0;
/* Scan command line options, adjust parameters */
@@ -204,54 +209,54 @@ parse_switches (j_decompress_ptr cinfo, int argc, char **argv,
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 */
+ outfilename = NULL; /* -outfile applies to just one input file */
+ continue; /* ignore this name if previously processed */
}
- break; /* else done parsing switches */
+ break; /* else done parsing switches */
}
- arg++; /* advance past switch marker character */
+ 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)) {
+ keymatch(arg, "quantize", 1) || keymatch(arg, "quantise", 1)) {
/* Do color quantization. */
int val;
- if (++argn >= argc) /* advance to next argument */
- usage();
+ if (++argn >= argc) /* advance to next argument */
+ usage();
if (sscanf(argv[argn], "%d", &val) != 1)
- usage();
+ 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 (++argn >= argc) /* advance to next argument */
+ usage();
if (keymatch(argv[argn], "int", 1)) {
- cinfo->dct_method = JDCT_ISLOW;
+ cinfo->dct_method = JDCT_ISLOW;
} else if (keymatch(argv[argn], "fast", 2)) {
- cinfo->dct_method = JDCT_IFAST;
+ cinfo->dct_method = JDCT_IFAST;
} else if (keymatch(argv[argn], "float", 2)) {
- cinfo->dct_method = JDCT_FLOAT;
+ cinfo->dct_method = JDCT_FLOAT;
} else
- usage();
+ usage();
} else if (keymatch(arg, "dither", 2)) {
/* Select dithering algorithm. */
- if (++argn >= argc) /* advance to next argument */
- usage();
+ if (++argn >= argc) /* advance to next argument */
+ usage();
if (keymatch(argv[argn], "fs", 2)) {
- cinfo->dither_mode = JDITHER_FS;
+ cinfo->dither_mode = JDITHER_FS;
} else if (keymatch(argv[argn], "none", 2)) {
- cinfo->dither_mode = JDITHER_NONE;
+ cinfo->dither_mode = JDITHER_NONE;
} else if (keymatch(argv[argn], "ordered", 2)) {
- cinfo->dither_mode = JDITHER_ORDERED;
+ cinfo->dither_mode = JDITHER_ORDERED;
} else
- usage();
+ usage();
} else if (keymatch(arg, "debug", 1) || keymatch(arg, "verbose", 1)) {
/* Enable debug printouts. */
@@ -259,21 +264,26 @@ parse_switches (j_decompress_ptr cinfo, int argc, char **argv,
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;
+ 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->desired_number_of_colors = 216;
cinfo->dct_method = JDCT_FASTEST;
cinfo->do_fancy_upsampling = FALSE;
@@ -295,21 +305,21 @@ parse_switches (j_decompress_ptr cinfo, int argc, char **argv,
} 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;
+ 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);
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
}
@@ -318,12 +328,12 @@ parse_switches (j_decompress_ptr cinfo, int argc, char **argv,
long lval;
char ch = 'x';
- if (++argn >= argc) /* advance to next argument */
- usage();
+ if (++argn >= argc) /* advance to next argument */
+ usage();
if (sscanf(argv[argn], "%ld%c", &lval, &ch) < 1)
- usage();
+ usage();
if (ch == 'm' || ch == 'M')
- lval *= 1000L;
+ lval *= 1000L;
cinfo->mem->max_memory_to_use = lval * 1000L;
} else if (keymatch(arg, "nosmooth", 3)) {
@@ -340,9 +350,9 @@ parse_switches (j_decompress_ptr cinfo, int argc, char **argv,
} 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 */
+ 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 */
@@ -364,36 +374,40 @@ parse_switches (j_decompress_ptr cinfo, int argc, char **argv,
} 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], "%d/%d",
- &cinfo->scale_num, &cinfo->scale_denom) != 2)
- usage();
-
- } else if (keymatch(arg, "strip", 2)) {
- if (++argn >= argc)
+ if (++argn >= argc) /* advance to next argument */
usage();
- if (sscanf(argv[argn], "%d,%d", &startY, &endY) != 2 || startY > endY)
+ if (sscanf(argv[argn], "%u/%u",
+ &cinfo->scale_num, &cinfo->scale_denom) != 2)
usage();
- strip = TRUE;
} else if (keymatch(arg, "skip", 2)) {
if (++argn >= argc)
usage();
- if (sscanf(argv[argn], "%d,%d", &startY, &endY) != 2 || startY > endY)
+ 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 */
+ usage(); /* bogus switch */
}
}
- return argn; /* return index of next arg (file name) */
+ return argn; /* return index of next arg (file name) */
}
@@ -408,7 +422,7 @@ LOCAL(unsigned int)
jpeg_getc (j_decompress_ptr cinfo)
/* Read next byte */
{
- struct jpeg_source_mgr * datasrc = cinfo->src;
+ struct jpeg_source_mgr *datasrc = cinfo->src;
if (datasrc->bytes_in_buffer == 0) {
if (! (*datasrc->fill_input_buffer) (cinfo))
@@ -423,20 +437,20 @@ METHODDEF(boolean)
print_text_marker (j_decompress_ptr cinfo)
{
boolean traceit = (cinfo->err->trace_level >= 1);
- INT32 length;
+ 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 */
+ 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 */
+ else /* assume it is an APPn otherwise */
fprintf(stderr, "APP%d, length %ld:\n",
- cinfo->unread_marker - JPEG_APP0, (long) length);
+ cinfo->unread_marker - JPEG_APP0, (long) length);
}
while (--length >= 0) {
@@ -448,16 +462,16 @@ print_text_marker (j_decompress_ptr cinfo)
* Newlines in CR, CR/LF, or LF form will be printed as one newline.
*/
if (ch == '\r') {
- fprintf(stderr, "\n");
+ fprintf(stderr, "\n");
} else if (ch == '\n') {
- if (lastch != '\r')
- fprintf(stderr, "\n");
+ if (lastch != '\r')
+ fprintf(stderr, "\n");
} else if (ch == '\\') {
- fprintf(stderr, "\\\\");
+ fprintf(stderr, "\\\\");
} else if (isprint(ch)) {
- putc(ch, stderr);
+ putc(ch, stderr);
} else {
- fprintf(stderr, "\\%03o", ch);
+ fprintf(stderr, "\\%03o", ch);
}
lastch = ch;
}
@@ -484,8 +498,8 @@ main (int argc, char **argv)
#endif
int file_index;
djpeg_dest_ptr dest_mgr = NULL;
- FILE * input_file;
- FILE * output_file;
+ FILE *input_file;
+ FILE *output_file;
unsigned char *inbuffer = NULL;
unsigned long insize = 0;
JDIMENSION num_scanlines;
@@ -497,7 +511,7 @@ main (int argc, char **argv)
progname = argv[0];
if (progname == NULL || progname[0] == 0)
- progname = "djpeg"; /* in case C library doesn't provide it */
+ 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);
@@ -516,11 +530,6 @@ main (int argc, char **argv)
jpeg_set_marker_processor(&cinfo, JPEG_COM, print_text_marker);
jpeg_set_marker_processor(&cinfo, JPEG_APP0+12, print_text_marker);
- /* Now safe to enable signal catcher. */
-#ifdef NEED_SIGNAL_CATCHER
- enable_signal_catcher((j_common_ptr) &cinfo);
-#endif
-
/* 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
@@ -536,14 +545,14 @@ main (int argc, char **argv)
if (outfilename == NULL) {
if (file_index != argc-2) {
fprintf(stderr, "%s: must name one input and one output file\n",
- progname);
+ 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);
+ progname);
usage();
}
}
@@ -654,54 +663,78 @@ main (int argc, char **argv)
/* Start decompressor */
(void) jpeg_start_decompress(&cinfo);
- /* Strip decode */
- if (strip || skip) {
+ /* Skip rows */
+ if (skip) {
JDIMENSION tmp;
- /* Check for valid endY. We cannot check this value until after
+ /* Check for valid skip_end. We cannot check this value until after
* jpeg_start_decompress() is called. Note that we have already verified
- * that startY <= endY.
+ * that skip_start <= skip_end.
*/
- if (endY > cinfo.output_height - 1) {
- fprintf(stderr, "%s: strip %d-%d exceeds image height %d\n", progname,
- startY, endY, cinfo.output_height);
+ 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 image of the proper size for the partial decode.
+ * manager creates an output image of the proper size.
*/
tmp = cinfo.output_height;
- cinfo.output_height = endY - startY + 1;
- if (skip)
- cinfo.output_height = 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 */
- if (skip) {
- while (cinfo.output_scanline < startY) {
- 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, endY - startY + 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);
- }
- } else {
- jpeg_skip_scanlines(&cinfo, startY);
- while (cinfo.output_scanline <= endY) {
- 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 - endY + 1);
+ 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);
+ ((ppm_dest_ptr) dest_mgr)->buffer_width = cinfo.output_width *
+ cinfo.out_color_components *
+ sizeof(JSAMPLE);
+
+ /* 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 decode */
+ /* Normal full-image decompress */
} else {
/* Write output file header */
(*dest_mgr->start_output) (&cinfo, dest_mgr);
@@ -744,5 +777,5 @@ main (int argc, char **argv)
/* All done. */
exit(jerr.num_warnings ? EXIT_WARNING : EXIT_SUCCESS);
- return 0; /* suppress no-return-value warnings */
+ return 0; /* suppress no-return-value warnings */
}

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