Files
mozjpeg/djpeg.c
DRC 94c64ead85 Various doc tweaks
- "bits per component" = "bits per sample"

  Describing the data precision of a JPEG image using "bits per
  component" is technically correct, but "bits per sample" is the
  terminology that the JPEG-1 spec uses.  Also, "bits per component" is
  more commonly used to describe the precision of packed-pixel formats
  (as opposed to "bits per pixel") rather than planar formats, in which
  all components are grouped together.

- Unmention legacy display technologies.  Colormapped and monochrome
  displays aren't a thing anymore, and even when they were still a
  thing, it was possible to display full-color images to them.  In 1991,
  when JPEG decompression time was measured in minutes per megapixel, it
  made sense to keep a decompressed copy of JPEG images on disk, in a
  format that could be displayed without further color conversion (since
  color conversion was slow and memory-intensive.)  In 2024, JPEG
  decompression time is measured in milliseconds per megapixel, and
  color conversion is even faster.  Thus, JPEG images can be
  decompressed, displayed, and color-converted (if necessary) "on the
  fly" at speeds too fast for human vision to perceive.  (In fact, your
  TV performs much more complicated decompression algorithms at least 60
  times per second.)

- Document that color quantization (and associated features), GIF
  input/output, Targa input/output, and OS/2 BMP input/output are legacy
  features.  Legacy status doesn't necessarily mean that the features
  are deprecated.  Rather, it is meant to discourage users from using
  features that may be of little or no benefit on modern machines (such
  as low-quality modes that had significant performance advantages in
  the early 1990s but no longer do) and that are maintained on a
  break/fix basis only.

- General wordsmithing, grammar/punctuation policing, and formatting
  tweaks

- Clarify which data precisions each cjpeg input format and each djpeg
  output format supports.

- cjpeg.1: Remove unnecessary and impolitic statement about the -targa
  switch.

- Adjust or remove performance claims to reflect the fact that:
  * On modern machines, the djpeg "-fast" switch has a negligible effect
    on performance.
  * There is a measurable difference between the performance of Floyd-
    Steinberg dithering and no dithering, but it is not likely
    perceptible to most users.
  * There is a measurable difference between the performance of 1-pass
    and 2-pass color quantization, but it is not likely perceptible to
    most users.
  * There is a measurable difference between the performance of
    full-color and grayscale output when decompressing a full-color JPEG
    image, but it is not likely perceptible to most users.
  * IDCT scaling does not necessarily improve performance.  (It
    generally does if the scaling factor is <= 1/2 and generally doesn't
    if the scaling factor is > 1/2, at least on my machine.  The
    performance claim made in jpeg-6b was probably invalidated when we
    merged the additional scaling factors from jpeg-7.)

- Clarify which djpeg switches/output formats cannot be used when
  decompressing lossless JPEG images.

- Remove djpeg hints, since those involve quality vs. speed tradeoffs
  that are no longer relevant for modern machines.

- Remove documentation regarding using color quantization with 16-bit
  data precision.  (Color quantization requires lossy mode.)

- Java: Fix typos in TJDecompressor.decompress12() and
  TJDecompressor.decompress16() documentation.

- jpegtran.1: Fix truncated paragraph

  In a man page, a single quote at the start of a line is interpreted as
  a macro.

  Closes #775

- libjpeg.txt:
  * Mention J16SAMPLE data type (oversight.)
  * Remove statement about extending jdcolor.c.  (libjpeg-turbo is not
    quite as DIY as libjpeg once was.)
  * Remove paragraph about tweaking the various typedefs in jmorecfg.h.
    It is no longer relevant for modern machines.
  * Remove caveat regarding systems with ints less than 16 bits wide.
    (ANSI/ISO C requires an int to be at least 16 bits wide, and
    libjpeg-turbo has never supported non-ANSI compilers.)

- usage.txt:
  * Add copyright header.
  * Document cjpeg -icc, -memdst, -report, -strict, and -version
    switches.
  * Document djpeg -icc, -maxscans, -memsrc, -report, -skip, -crop,
    -strict, and -version switches.
  * Document jpegtran -icc, -maxscans, -report, -strict, and -version
    switches.
2024-06-24 22:11:43 -04:00

935 lines
32 KiB
C

/*
* djpeg.c
*
* This file was part of the Independent JPEG Group's software:
* Copyright (C) 1991-1997, Thomas G. Lane.
* Modified 2013-2019 by Guido Vollbeding.
* libjpeg-turbo Modifications:
* Copyright (C) 2010-2011, 2013-2017, 2019-2020, 2022-2024, 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.
*/
#ifdef _MSC_VER
#define _CRT_SECURE_NO_DEPRECATE
#endif
#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
#include "jversion.h" /* for version message */
#include "jconfigint.h"
#include <ctype.h> /* to declare isprint() */
/* 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 (LZW-compressed) */
FMT_GIF0, /* GIF format (uncompressed) */
FMT_OS2, /* BMP format (OS/2 flavor) */
FMT_PPM, /* PPM/PGM (PBMPLUS formats) */
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 JDIMENSION max_scans; /* for -maxscans switch */
static char *outfilename; /* for -outfile switch */
static boolean memsrc; /* for -memsrc switch */
static boolean report; /* for -report switch */
static boolean skip, crop;
static JDIMENSION skip_start, skip_end;
static JDIMENSION crop_x, crop_y, crop_width, crop_height;
static boolean strict; /* for -strict switch */
#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 [legacy feature]\n");
fprintf(stderr, " -fast Low-quality processing [legacy feature]\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 (LZW-compressed)%s [legacy feature]\n",
(DEFAULT_FMT == FMT_GIF ? " (default)" : ""));
fprintf(stderr, " -gif0 Select GIF output format (uncompressed)%s [legacy feature]\n",
(DEFAULT_FMT == FMT_GIF0 ? " (default)" : ""));
#endif
#ifdef BMP_SUPPORTED
fprintf(stderr, " -os2 Select BMP output format (OS/2 style)%s [legacy feature]\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 TARGA_SUPPORTED
fprintf(stderr, " -targa Select Targa output format%s [legacy feature]\n",
(DEFAULT_FMT == FMT_TARGA ? " (default)" : ""));
#endif
fprintf(stderr, "Switches for advanced users:\n");
#ifdef DCT_ISLOW_SUPPORTED
fprintf(stderr, " -dct int Use accurate integer DCT method%s\n",
(JDCT_DEFAULT == JDCT_ISLOW ? " (default)" : ""));
#endif
#ifdef DCT_IFAST_SUPPORTED
fprintf(stderr, " -dct fast Use less accurate integer DCT method [legacy feature]%s\n",
(JDCT_DEFAULT == JDCT_IFAST ? " (default)" : ""));
#endif
#ifdef DCT_FLOAT_SUPPORTED
fprintf(stderr, " -dct float Use floating-point DCT method [legacy feature]%s\n",
(JDCT_DEFAULT == JDCT_FLOAT ? " (default)" : ""));
#endif
fprintf(stderr, " -dither fs Use Floyd-Steinberg dithering when quantizing colors (default)\n");
fprintf(stderr, " [legacy feature]\n");
fprintf(stderr, " -dither none Don't use dithering when quantizing colors [legacy feature]\n");
fprintf(stderr, " -dither ordered Use ordered dithering when quantizing colors\n");
fprintf(stderr, " [legacy feature]\n");
fprintf(stderr, " -icc FILE Extract ICC profile to FILE\n");
#ifdef QUANT_2PASS_SUPPORTED
fprintf(stderr, " -map FILE Quantize to colors used in named image file [legacy feature]\n");
#endif
fprintf(stderr, " -nosmooth Use faster, lower-quality upsampling\n");
#ifdef QUANT_1PASS_SUPPORTED
fprintf(stderr, " -onepass Use 1-pass color quantization (low quality) [legacy feature]\n");
#endif
fprintf(stderr, " -maxmemory N Maximum memory to use (in kbytes)\n");
fprintf(stderr, " -maxscans N Maximum number of scans to allow in input file\n");
fprintf(stderr, " -outfile name Specify name for output file\n");
fprintf(stderr, " -memsrc Load input file into memory before decompressing\n");
fprintf(stderr, " -report Report decompression progress\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, " [requires PBMPLUS (PPM/PGM), GIF, or Targa output format]\n");
fprintf(stderr, " -strict Treat all warnings as fatal\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;
max_scans = 0;
outfilename = NULL;
memsrc = FALSE;
report = FALSE;
skip = FALSE;
crop = FALSE;
strict = 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 (Windows flavor). */
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, JCOPYRIGHT1);
fprintf(stderr, JCOPYRIGHT2 "\n");
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 (LZW-compressed). */
requested_fmt = FMT_GIF;
} else if (keymatch(arg, "gif0", 4)) {
/* GIF output format (uncompressed). */
requested_fmt = FMT_GIF0;
} 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];
#ifdef SAVE_MARKERS_SUPPORTED
jpeg_save_markers(cinfo, JPEG_APP0 + 2, 0xFFFF);
#endif
} 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);
}
if (cinfo->data_precision == 12)
read_color_map_12(cinfo, mapfile);
else
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, "maxscans", 4)) {
if (++argn >= argc) /* advance to next argument */
usage();
if (sscanf(argv[argn], "%u", &max_scans) != 1)
usage();
} 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 */
memsrc = TRUE;
} else if (keymatch(arg, "pnm", 1) || keymatch(arg, "ppm", 1)) {
/* PPM/PGM output format. */
requested_fmt = FMT_PPM;
} else if (keymatch(arg, "report", 2)) {
report = TRUE;
} 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, "strict", 2)) {
strict = 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 *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;
}
METHODDEF(void)
my_emit_message(j_common_ptr cinfo, int msg_level)
{
if (msg_level < 0) {
/* Treat warning as fatal */
cinfo->err->error_exit(cinfo);
} else {
if (cinfo->err->trace_level >= msg_level)
cinfo->err->output_message(cinfo);
}
}
/*
* The main program.
*/
int
main(int argc, char **argv)
{
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
struct cdjpeg_progress_mgr progress;
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;
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);
if (strict)
jerr.emit_message = my_emit_message;
#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();
}
if (report || max_scans != 0) {
start_progress_monitor((j_common_ptr)&cinfo, &progress);
progress.report = report;
progress.max_scans = max_scans;
}
/* Specify data source for decompression */
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 = fread(&inbuffer[insize], 1, INPUT_BUF_SIZE, input_file);
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
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:
if (cinfo.data_precision == 16)
ERREXIT1(&cinfo, JERR_BAD_PRECISION, cinfo.data_precision);
else if (cinfo.data_precision == 12)
dest_mgr = j12init_write_gif(&cinfo, TRUE);
else
dest_mgr = jinit_write_gif(&cinfo, TRUE);
break;
case FMT_GIF0:
dest_mgr = jinit_write_gif(&cinfo, FALSE);
break;
#endif
#ifdef PPM_SUPPORTED
case FMT_PPM:
if (cinfo.data_precision == 16)
#ifdef D_LOSSLESS_SUPPORTED
dest_mgr = j16init_write_ppm(&cinfo);
#else
ERREXIT1(&cinfo, JERR_BAD_PRECISION, cinfo.data_precision);
#endif
else if (cinfo.data_precision == 12)
dest_mgr = j12init_write_ppm(&cinfo);
else
dest_mgr = jinit_write_ppm(&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 %u\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;
if (cinfo.data_precision == 16)
ERREXIT(&cinfo, JERR_NOTIMPL);
else if (cinfo.data_precision == 12) {
/* Process data */
while (cinfo.output_scanline < skip_start) {
num_scanlines = jpeg12_read_scanlines(&cinfo, dest_mgr->buffer12,
dest_mgr->buffer_height);
(*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines);
}
if ((tmp = jpeg12_skip_scanlines(&cinfo, skip_end - skip_start + 1)) !=
skip_end - skip_start + 1) {
fprintf(stderr, "%s: jpeg12_skip_scanlines() returned %u rather than %u\n",
progname, tmp, skip_end - skip_start + 1);
exit(EXIT_FAILURE);
}
while (cinfo.output_scanline < cinfo.output_height) {
num_scanlines = jpeg12_read_scanlines(&cinfo, dest_mgr->buffer12,
dest_mgr->buffer_height);
(*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines);
}
} else {
/* 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);
}
if ((tmp = jpeg_skip_scanlines(&cinfo, skip_end - skip_start + 1)) !=
skip_end - skip_start + 1) {
fprintf(stderr, "%s: jpeg_skip_scanlines() returned %u rather than %u\n",
progname, tmp, skip_end - skip_start + 1);
exit(EXIT_FAILURE);
}
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 %u x %u\n",
progname, cinfo.output_width, cinfo.output_height);
exit(EXIT_FAILURE);
}
if (cinfo.data_precision == 16)
ERREXIT(&cinfo, JERR_NOTIMPL);
else if (cinfo.data_precision == 12)
jpeg12_crop_scanline(&cinfo, &crop_x, &crop_width);
else
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;
if (cinfo.data_precision == 16)
ERREXIT(&cinfo, JERR_NOTIMPL);
else if (cinfo.data_precision == 12) {
/* Process data */
if ((tmp = jpeg12_skip_scanlines(&cinfo, crop_y)) != crop_y) {
fprintf(stderr, "%s: jpeg12_skip_scanlines() returned %u rather than %u\n",
progname, tmp, crop_y);
exit(EXIT_FAILURE);
}
while (cinfo.output_scanline < crop_y + crop_height) {
num_scanlines = jpeg12_read_scanlines(&cinfo, dest_mgr->buffer12,
dest_mgr->buffer_height);
(*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines);
}
if ((tmp =
jpeg12_skip_scanlines(&cinfo, cinfo.output_height - crop_y -
crop_height)) !=
cinfo.output_height - crop_y - crop_height) {
fprintf(stderr, "%s: jpeg12_skip_scanlines() returned %u rather than %u\n",
progname, tmp, cinfo.output_height - crop_y - crop_height);
exit(EXIT_FAILURE);
}
} else {
/* Process data */
if ((tmp = jpeg_skip_scanlines(&cinfo, crop_y)) != crop_y) {
fprintf(stderr, "%s: jpeg_skip_scanlines() returned %u rather than %u\n",
progname, tmp, crop_y);
exit(EXIT_FAILURE);
}
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);
}
if ((tmp =
jpeg_skip_scanlines(&cinfo,
cinfo.output_height - crop_y - crop_height)) !=
cinfo.output_height - crop_y - crop_height) {
fprintf(stderr, "%s: jpeg_skip_scanlines() returned %u rather than %u\n",
progname, tmp, cinfo.output_height - crop_y - crop_height);
exit(EXIT_FAILURE);
}
}
/* Normal full-image decompress */
} else {
/* Write output file header */
(*dest_mgr->start_output) (&cinfo, dest_mgr);
if (cinfo.data_precision == 16) {
#ifdef D_LOSSLESS_SUPPORTED
/* Process data */
while (cinfo.output_scanline < cinfo.output_height) {
num_scanlines = jpeg16_read_scanlines(&cinfo, dest_mgr->buffer16,
dest_mgr->buffer_height);
(*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines);
}
#else
ERREXIT1(&cinfo, JERR_BAD_PRECISION, cinfo.data_precision);
#endif
} else if (cinfo.data_precision == 12) {
/* Process data */
while (cinfo.output_scanline < cinfo.output_height) {
num_scanlines = jpeg12_read_scanlines(&cinfo, dest_mgr->buffer12,
dest_mgr->buffer_height);
(*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines);
}
} else {
/* 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);
}
}
}
/* Hack: count final pass as done in case finish_output does an extra pass.
* The library won't have updated completed_passes.
*/
if (report || max_scans != 0)
progress.pub.completed_passes = progress.pub.total_passes;
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);
if (report || max_scans != 0)
end_progress_monitor((j_common_ptr)&cinfo);
if (memsrc)
free(inbuffer);
/* All done. */
exit(jerr.num_warnings ? EXIT_WARNING : EXIT_SUCCESS);
return 0; /* suppress no-return-value warnings */
}