djpeg.c

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Hash : e8b40f3c
Author :
Date : 2022-11-01T21:45:39

Vastly improve 12-bit JPEG integration

The Gordian knot that 7fec5074f962b20ed00b4f5da4533e1e8d4ed8ac attempted
to unravel was caused by the fact that there are several
data-precision-dependent (JSAMPLE-dependent) fields and methods in the
exposed libjpeg API structures, and if you change the exposed libjpeg
API structures, then you have to change the whole API.  If you change
the whole API, then you have to provide a whole new library to support
the new API, and that makes it difficult to support multiple data
precisions in the same application.  (It is not impossible, as example.c
demonstrated, but using data-precision-dependent libjpeg API structures
would have made the cjpeg, djpeg, and jpegtran source code hard to read,
so it made more sense to build, install, and package 12-bit-specific
versions of those applications.)

Unfortunately, the result of that initial integration effort was an
unreadable and unmaintainable mess, which is a problem for a library
that is an ISO/ITU-T reference implementation.  Also, as I dug into the
problem of lossless JPEG support, I realized that 16-bit lossless JPEG
images are a thing, and supporting yet another version of the libjpeg
API just for those images is untenable.

In fact, however, the touch points for JSAMPLE in the exposed libjpeg
API structures are minimal:

  - The colormap and sample_range_limit fields in jpeg_decompress_struct
  - The alloc_sarray() and access_virt_sarray() methods in
    jpeg_memory_mgr
  - jpeg_write_scanlines() and jpeg_write_raw_data()
  - jpeg_read_scanlines() and jpeg_read_raw_data()
  - jpeg_skip_scanlines() and jpeg_crop_scanline()
    (This is subtle, but both of those functions use JSAMPLE-dependent
    opaque structures behind the scenes.)

It is much more readable and maintainable to provide 12-bit-specific
versions of those six top-level API functions and to document that the
aforementioned methods and fields must be type-cast when using 12-bit
samples.  Since that eliminates the need to provide a 12-bit-specific
version of the exposed libjpeg API structures, we can:

  - Compile only the precision-dependent libjpeg modules (the
    coefficient buffer controllers, the colorspace converters, the
    DCT/IDCT managers, the main buffer controllers, the preprocessing
    and postprocessing controller, the downsampler and upsamplers, the
    quantizers, the integer DCT methods, and the IDCT methods) for
    multiple data precisions.
  - Introduce 12-bit-specific methods into the various internal
    structures defined in jpegint.h.
  - Create precision-independent data type, macro, method, field, and
    function names that are prefixed by an underscore, and use an
    internal header to convert those into precision-dependent data
    type, macro, method, field, and function names, based on the value
    of BITS_IN_JSAMPLE, when compiling the precision-dependent libjpeg
    modules.
  - Expose precision-dependent jinit*() functions for each of the
    precision-dependent libjpeg modules.
  - Abstract the precision-dependent libjpeg modules by calling the
    appropriate precision-dependent jinit*() function, based on the
    value of cinfo->data_precision, from top-level libjpeg API
    functions.

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djpeg.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, 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 */
JDIMENSION max_scans;           /* for -maxscans switch */
static char *outfilename;       /* for -outfile switch */
boolean memsrc;                 /* for -memsrc switch */
boolean report;                 /* for -report switch */
boolean skip, crop;
JDIMENSION skip_start, skip_end;
JDIMENSION crop_x, crop_y, crop_width, crop_height;
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\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 (LZW-compressed)%s\n",
          (DEFAULT_FMT == FMT_GIF ? " (default)" : ""));
  fprintf(stderr, "  -gif0          Select GIF output format (uncompressed)%s\n",
          (DEFAULT_FMT == FMT_GIF0 ? " (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 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 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 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, "  -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, "%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 (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];
      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, "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:
#ifdef WITH_12BIT
    if (cinfo.data_precision == 12)
      dest_mgr = j12init_write_gif(&cinfo, TRUE);
    else
#endif
      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:
#ifdef WITH_12BIT
    if (cinfo.data_precision == 12)
      dest_mgr = j12init_write_ppm(&cinfo);
    else
#endif
      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;

#ifdef WITH_12BIT
    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
#endif
    {
      /* 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);
    }

#ifdef WITH_12BIT
    if (cinfo.data_precision == 12)
      jpeg12_crop_scanline(&cinfo, &crop_x, &crop_width);
    else
#endif
      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;

#ifdef WITH_12BIT
    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
#endif
    {
      /* 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);

#ifdef WITH_12BIT
    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
#endif
    {
      /* 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 */
}

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kc3-lang/libjpeg-turbo/djpeg.c

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djpeg.c