cdjpeg.h

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Hash : b56e8b28
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Date : 2022-11-08T15:01:18

Clean up the lossless JPEG feature

- Rename jpeg_simple_lossless() to jpeg_enable_lossless() and modify the
  function so that it stores the lossless parameters directly in the Ss
  and Al fields of jpeg_compress_struct rather than using a scan script.

- Move the cjpeg -lossless switch into "Switches for advanced users".

- Document the libjpeg API and run-time features that are unavailable in
  lossless mode, and ensure that all parameters, functions, and switches
  related to unavailable features are ignored or generate errors in
  lossless mode.

- Defer any action that depends on whether lossless mode is enabled
  until jpeg_start_compress()/jpeg_start_decompress() is called.

- Document the purpose of the point transform value.

- "Codec" stands for coder/decoder, so it is a bit awkward to say
  "lossless compression codec" and "lossless decompression codec".
  Use "lossless compressor" and "lossless decompressor" instead.

- Restore backward API/ABI compatibility with libjpeg v6b:

  * Move the new 'lossless' field from the exposed jpeg_compress_struct
    and jpeg_decompress_struct structures into the opaque
    jpeg_comp_master and jpeg_decomp_master structures, and allocate the
    master structures in the body of jpeg_create_compress() and
    jpeg_create_decompress().

  * Remove the new 'process' field from jpeg_compress_struct and
    jpeg_decompress_struct and replace it with the old
    'progressive_mode' field and the new 'lossless' field.

  * Remove the new 'data_unit' field from jpeg_compress_struct and
    jpeg_decompress_struct and replace it with a locally-computed
    data unit variable.

  * Restore the names of macros and fields that refer to DCT blocks, and
    document that they have a different meaning in lossless mode.  (Most
    of them aren't very meaningful in lossless mode anyhow.)

  * Remove the new alloc_darray() method from jpeg_memory_mgr and
    replace it with an internal macro that wraps the alloc_sarray()
    method.

  * Move the JDIFF* data types from jpeglib.h and jmorecfg.h into
    jpegint.h.

  * Remove the new 'codec' field from jpeg_compress_struct and
    jpeg_decompress_struct and instead reuse the existing internal
    coefficient control, forward/inverse DCT, and entropy
    encoding/decoding structures for lossless compression/decompression.

  * Repurpose existing error codes rather than introducing new ones.
    (The new JERR_BAD_RESTART and JWRN_MUST_DOWNSCALE codes remain,
    although JWRN_MUST_DOWNSCALE will probably be removed in
    libjpeg-turbo, since we have a different way of handling multiple
    data precisions.)

- Automatically enable lossless mode when a scan script with parameters
  that are only valid for lossless mode is detected, and document the
  use of scan scripts to generate lossless JPEG images.

- Move the sequential and shared Huffman routines back into jchuff.c and
  jdhuff.c, and document that those routines are shared with jclhuff.c
  and jdlhuff.c as well as with jcphuff.c and jdphuff.c.

- Move MAX_DIFF_BITS from jchuff.h into jclhuff.c, the only place where
  it is used.

- Move the predictor and scaler code into jclossls.c and jdlossls.c.

- Streamline register usage in the [un]differencers (inspired by similar
  optimizations in the color [de]converters.)

- Restructure the logic in a few places to reduce duplicated code.

- Ensure that all lossless-specific code is guarded by
  C_LOSSLESS_SUPPORTED or D_LOSSLESS_SUPPORTED and that the library can
  be built successfully if either or both of those macros is undefined.

- Remove all short forms of external names introduced by the lossless
  JPEG patch.  (These will not be needed by libjpeg-turbo, so there is
  no use cleaning them up.)

- Various wordsmithing, formatting, and punctuation tweaks

- Eliminate various compiler warnings.

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cdjpeg.h

/*
 * cdjpeg.h
 *
 * This file was part of the Independent JPEG Group's software:
 * Copyright (C) 1994-1997, Thomas G. Lane.
 * Modified 2019 by Guido Vollbeding.
 * libjpeg-turbo Modifications:
 * Copyright (C) 2017, 2019, 2021-2022, D. R. Commander.
 * For conditions of distribution and use, see the accompanying README.ijg
 * file.
 *
 * This file contains common declarations for the sample applications
 * cjpeg and djpeg.  It is NOT used by the core JPEG library.
 */

#define JPEG_CJPEG_DJPEG        /* define proper options in jconfig.h */
#define JPEG_INTERNAL_OPTIONS   /* cjpeg.c,djpeg.c need to see xxx_SUPPORTED */
#include "jinclude.h"
#include "jpeglib.h"
#include "jerror.h"             /* get library error codes too */
#include "cderror.h"            /* get application-specific error codes */


/*
 * Object interface for cjpeg's source file decoding modules
 */

typedef struct cjpeg_source_struct *cjpeg_source_ptr;

struct cjpeg_source_struct {
  void (*start_input) (j_compress_ptr cinfo, cjpeg_source_ptr sinfo);
  JDIMENSION (*get_pixel_rows) (j_compress_ptr cinfo, cjpeg_source_ptr sinfo);
  void (*finish_input) (j_compress_ptr cinfo, cjpeg_source_ptr sinfo);

  FILE *input_file;

  JSAMPARRAY buffer;
  J12SAMPARRAY buffer12;
  JDIMENSION buffer_height;
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
  JDIMENSION max_pixels;
#endif
};


/*
 * Object interface for djpeg's output file encoding modules
 */

typedef struct djpeg_dest_struct *djpeg_dest_ptr;

struct djpeg_dest_struct {
  /* start_output is called after jpeg_start_decompress finishes.
   * The color map will be ready at this time, if one is needed.
   */
  void (*start_output) (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo);
  /* Emit the specified number of pixel rows from the buffer. */
  void (*put_pixel_rows) (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
                          JDIMENSION rows_supplied);
  /* Finish up at the end of the image. */
  void (*finish_output) (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo);
  /* Re-calculate buffer dimensions based on output dimensions (for use with
     partial image decompression.)  If this is NULL, then the output format
     does not support partial image decompression (BMP, in particular, cannot
     support partial decompression because it uses an inversion buffer to write
     the image in bottom-up order.) */
  void (*calc_buffer_dimensions) (j_decompress_ptr cinfo,
                                  djpeg_dest_ptr dinfo);


  /* Target file spec; filled in by djpeg.c after object is created. */
  FILE *output_file;

  /* Output pixel-row buffer.  Created by module init or start_output.
   * Width is cinfo->output_width * cinfo->output_components;
   * height is buffer_height.
   */
  JSAMPARRAY buffer;
  J12SAMPARRAY buffer12;
  JDIMENSION buffer_height;
};


/*
 * cjpeg/djpeg may need to perform extra passes to convert to or from
 * the source/destination file format.  The JPEG library does not know
 * about these passes, but we'd like them to be counted by the progress
 * monitor.  We use an expanded progress monitor object to hold the
 * additional pass count.
 */

struct cdjpeg_progress_mgr {
  struct jpeg_progress_mgr pub; /* fields known to JPEG library */
  int completed_extra_passes;   /* extra passes completed */
  int total_extra_passes;       /* total extra */
  JDIMENSION max_scans;         /* abort if the number of scans exceeds this
                                   value and the value is non-zero */
  boolean report;               /* whether or not to report progress */
  /* last printed percentage stored here to avoid multiple printouts */
  int percent_done;
};

typedef struct cdjpeg_progress_mgr *cd_progress_ptr;


/* Module selection routines for I/O modules. */

EXTERN(cjpeg_source_ptr) jinit_read_bmp(j_compress_ptr cinfo,
                                        boolean use_inversion_array);
EXTERN(djpeg_dest_ptr) jinit_write_bmp(j_decompress_ptr cinfo, boolean is_os2,
                                       boolean use_inversion_array);
EXTERN(cjpeg_source_ptr) jinit_read_gif(j_compress_ptr cinfo);
EXTERN(cjpeg_source_ptr) j12init_read_gif(j_compress_ptr cinfo);
EXTERN(djpeg_dest_ptr) jinit_write_gif(j_decompress_ptr cinfo, boolean is_lzw);
EXTERN(djpeg_dest_ptr) j12init_write_gif(j_decompress_ptr cinfo,
                                         boolean is_lzw);
EXTERN(cjpeg_source_ptr) jinit_read_ppm(j_compress_ptr cinfo);
EXTERN(cjpeg_source_ptr) j12init_read_ppm(j_compress_ptr cinfo);
EXTERN(djpeg_dest_ptr) jinit_write_ppm(j_decompress_ptr cinfo);
EXTERN(djpeg_dest_ptr) j12init_write_ppm(j_decompress_ptr cinfo);
EXTERN(cjpeg_source_ptr) jinit_read_targa(j_compress_ptr cinfo);
EXTERN(djpeg_dest_ptr) jinit_write_targa(j_decompress_ptr cinfo);

/* cjpeg support routines (in rdswitch.c) */

EXTERN(boolean) read_quant_tables(j_compress_ptr cinfo, char *filename,
                                  boolean force_baseline);
EXTERN(boolean) read_scan_script(j_compress_ptr cinfo, char *filename);
EXTERN(boolean) set_quality_ratings(j_compress_ptr cinfo, char *arg,
                                    boolean force_baseline);
EXTERN(boolean) set_quant_slots(j_compress_ptr cinfo, char *arg);
EXTERN(boolean) set_sample_factors(j_compress_ptr cinfo, char *arg);

/* djpeg support routines (in rdcolmap.c) */

EXTERN(void) read_color_map(j_decompress_ptr cinfo, FILE *infile);
EXTERN(void) read_color_map_12(j_decompress_ptr cinfo, FILE *infile);

/* common support routines (in cdjpeg.c) */

EXTERN(void) start_progress_monitor(j_common_ptr cinfo,
                                    cd_progress_ptr progress);
EXTERN(void) end_progress_monitor(j_common_ptr cinfo);
EXTERN(boolean) keymatch(char *arg, const char *keyword, int minchars);
EXTERN(FILE *) read_stdin(void);
EXTERN(FILE *) write_stdout(void);

/* miscellaneous useful macros */

#ifdef DONT_USE_B_MODE          /* define mode parameters for fopen() */
#define READ_BINARY     "r"
#define WRITE_BINARY    "w"
#else
#define READ_BINARY     "rb"
#define WRITE_BINARY    "wb"
#endif

#ifndef EXIT_FAILURE            /* define exit() codes if not provided */
#define EXIT_FAILURE  1
#endif
#ifndef EXIT_SUCCESS
#define EXIT_SUCCESS  0
#endif
#ifndef EXIT_WARNING
#define EXIT_WARNING  2
#endif

#define IsExtRGB(cs) \
  (cs == JCS_RGB || (cs >= JCS_EXT_RGB && cs <= JCS_EXT_ARGB))

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kc3-lang/libjpeg-turbo/cdjpeg.h

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cdjpeg.h