ryan/mozjpeg
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
e8b40f3c2ba187ba95c13c3e8ce21c8534256df7
mozjpeg/jpegint.h
DRC e8b40f3c2b Vastly improve 12-bit JPEG integration 
The Gordian knot that 7fec5074f9 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.
2022-11-04 12:30:33 -05:00

481 lines
20 KiB
C
Raw Blame History

/*
* jpegint.h
*
* This file was part of the Independent JPEG Group's software:
* Copyright (C) 1991-1997, Thomas G. Lane.
* Modified 1997-2009 by Guido Vollbeding.
* libjpeg-turbo Modifications:
* Copyright (C) 2015-2016, 2019, 2021-2022, D. R. Commander.
* Copyright (C) 2015, Google, Inc.
* Copyright (C) 2021, Alex Richardson.
* For conditions of distribution and use, see the accompanying README.ijg
* file.
*
* This file provides common declarations for the various JPEG modules.
* These declarations are considered internal to the JPEG library; most
* applications using the library shouldn't need to include this file.
*/
/* Declarations for both compression & decompression */
typedef enum { /* Operating modes for buffer controllers */
JBUF_PASS_THRU, /* Plain stripwise operation */
/* Remaining modes require a full-image buffer to have been created */
JBUF_SAVE_SOURCE, /* Run source subobject only, save output */
JBUF_CRANK_DEST, /* Run dest subobject only, using saved data */
JBUF_SAVE_AND_PASS /* Run both subobjects, save output */
} J_BUF_MODE;
/* Values of global_state field (jdapi.c has some dependencies on ordering!) */
#define CSTATE_START 100 /* after create_compress */
#define CSTATE_SCANNING 101 /* start_compress done, write_scanlines OK */
#define CSTATE_RAW_OK 102 /* start_compress done, write_raw_data OK */
#define CSTATE_WRCOEFS 103 /* jpeg_write_coefficients done */
#define DSTATE_START 200 /* after create_decompress */
#define DSTATE_INHEADER 201 /* reading header markers, no SOS yet */
#define DSTATE_READY 202 /* found SOS, ready for start_decompress */
#define DSTATE_PRELOAD 203 /* reading multiscan file in start_decompress*/
#define DSTATE_PRESCAN 204 /* performing dummy pass for 2-pass quant */
#define DSTATE_SCANNING 205 /* start_decompress done, read_scanlines OK */
#define DSTATE_RAW_OK 206 /* start_decompress done, read_raw_data OK */
#define DSTATE_BUFIMAGE 207 /* expecting jpeg_start_output */
#define DSTATE_BUFPOST 208 /* looking for SOS/EOI in jpeg_finish_output */
#define DSTATE_RDCOEFS 209 /* reading file in jpeg_read_coefficients */
#define DSTATE_STOPPING 210 /* looking for EOI in jpeg_finish_decompress */
/* JLONG must hold at least signed 32-bit values. */
typedef long JLONG;
/* JUINTPTR must hold pointer values. */
#ifdef __UINTPTR_TYPE__
/*
* __UINTPTR_TYPE__ is GNU-specific and available in GCC 4.6+ and Clang 3.0+.
* Fortunately, that is sufficient to support the few architectures for which
* sizeof(void *) != sizeof(size_t). The only other options would require C99
* or Clang-specific builtins.
*/
typedef __UINTPTR_TYPE__ JUINTPTR;
#else
typedef size_t JUINTPTR;
#endif
/*
* Left shift macro that handles a negative operand without causing any
* sanitizer warnings
*/
#define LEFT_SHIFT(a, b) ((JLONG)((unsigned long)(a) << (b)))
/* Declarations for compression modules */
/* Master control module */
struct jpeg_comp_master {
void (*prepare_for_pass) (j_compress_ptr cinfo);
void (*pass_startup) (j_compress_ptr cinfo);
void (*finish_pass) (j_compress_ptr cinfo);
/* State variables made visible to other modules */
boolean call_pass_startup; /* True if pass_startup must be called */
boolean is_last_pass; /* True during last pass */
};
/* Main buffer control (downsampled-data buffer) */
struct jpeg_c_main_controller {
void (*start_pass) (j_compress_ptr cinfo, J_BUF_MODE pass_mode);
void (*process_data) (j_compress_ptr cinfo, JSAMPARRAY input_buf,
JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail);
#ifdef WITH_12BIT
void (*process_data_12) (j_compress_ptr cinfo, J12SAMPARRAY input_buf,
JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail);
#endif
};
/* Compression preprocessing (downsampling input buffer control) */
struct jpeg_c_prep_controller {
void (*start_pass) (j_compress_ptr cinfo, J_BUF_MODE pass_mode);
void (*pre_process_data) (j_compress_ptr cinfo, JSAMPARRAY input_buf,
JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail,
JSAMPIMAGE output_buf,
JDIMENSION *out_row_group_ctr,
JDIMENSION out_row_groups_avail);
#ifdef WITH_12BIT
void (*pre_process_data_12) (j_compress_ptr cinfo, J12SAMPARRAY input_buf,
JDIMENSION *in_row_ctr,
JDIMENSION in_rows_avail,
J12SAMPIMAGE output_buf,
JDIMENSION *out_row_group_ctr,
JDIMENSION out_row_groups_avail);
#endif
};
/* Coefficient buffer control */
struct jpeg_c_coef_controller {
void (*start_pass) (j_compress_ptr cinfo, J_BUF_MODE pass_mode);
boolean (*compress_data) (j_compress_ptr cinfo, JSAMPIMAGE input_buf);
#ifdef WITH_12BIT
boolean (*compress_data_12) (j_compress_ptr cinfo, J12SAMPIMAGE input_buf);
#endif
};
/* Colorspace conversion */
struct jpeg_color_converter {
void (*start_pass) (j_compress_ptr cinfo);
void (*color_convert) (j_compress_ptr cinfo, JSAMPARRAY input_buf,
JSAMPIMAGE output_buf, JDIMENSION output_row,
int num_rows);
#ifdef WITH_12BIT
void (*color_convert_12) (j_compress_ptr cinfo, J12SAMPARRAY input_buf,
J12SAMPIMAGE output_buf, JDIMENSION output_row,
int num_rows);
#endif
};
/* Downsampling */
struct jpeg_downsampler {
void (*start_pass) (j_compress_ptr cinfo);
void (*downsample) (j_compress_ptr cinfo, JSAMPIMAGE input_buf,
JDIMENSION in_row_index, JSAMPIMAGE output_buf,
JDIMENSION out_row_group_index);
#ifdef WITH_12BIT
void (*downsample_12) (j_compress_ptr cinfo, J12SAMPIMAGE input_buf,
JDIMENSION in_row_index, J12SAMPIMAGE output_buf,
JDIMENSION out_row_group_index);
#endif
boolean need_context_rows; /* TRUE if need rows above & below */
};
/* Forward DCT (also controls coefficient quantization) */
struct jpeg_forward_dct {
void (*start_pass) (j_compress_ptr cinfo);
/* perhaps this should be an array??? */
void (*forward_DCT) (j_compress_ptr cinfo, jpeg_component_info *compptr,
JSAMPARRAY sample_data, JBLOCKROW coef_blocks,
JDIMENSION start_row, JDIMENSION start_col,
JDIMENSION num_blocks);
#ifdef WITH_12BIT
void (*forward_DCT_12) (j_compress_ptr cinfo, jpeg_component_info *compptr,
J12SAMPARRAY sample_data, JBLOCKROW coef_blocks,
JDIMENSION start_row, JDIMENSION start_col,
JDIMENSION num_blocks);
#endif
};
/* Entropy encoding */
struct jpeg_entropy_encoder {
void (*start_pass) (j_compress_ptr cinfo, boolean gather_statistics);
boolean (*encode_mcu) (j_compress_ptr cinfo, JBLOCKROW *MCU_data);
void (*finish_pass) (j_compress_ptr cinfo);
};
/* Marker writing */
struct jpeg_marker_writer {
void (*write_file_header) (j_compress_ptr cinfo);
void (*write_frame_header) (j_compress_ptr cinfo);
void (*write_scan_header) (j_compress_ptr cinfo);
void (*write_file_trailer) (j_compress_ptr cinfo);
void (*write_tables_only) (j_compress_ptr cinfo);
/* These routines are exported to allow insertion of extra markers */
/* Probably only COM and APPn markers should be written this way */
void (*write_marker_header) (j_compress_ptr cinfo, int marker,
unsigned int datalen);
void (*write_marker_byte) (j_compress_ptr cinfo, int val);
};
/* Declarations for decompression modules */
/* Master control module */
struct jpeg_decomp_master {
void (*prepare_for_output_pass) (j_decompress_ptr cinfo);
void (*finish_output_pass) (j_decompress_ptr cinfo);
/* State variables made visible to other modules */
boolean is_dummy_pass; /* True during 1st pass for 2-pass quant */
/* Partial decompression variables */
JDIMENSION first_iMCU_col;
JDIMENSION last_iMCU_col;
JDIMENSION first_MCU_col[MAX_COMPONENTS];
JDIMENSION last_MCU_col[MAX_COMPONENTS];
boolean jinit_upsampler_no_alloc;
/* Last iMCU row that was successfully decoded */
JDIMENSION last_good_iMCU_row;
};
/* Input control module */
struct jpeg_input_controller {
int (*consume_input) (j_decompress_ptr cinfo);
void (*reset_input_controller) (j_decompress_ptr cinfo);
void (*start_input_pass) (j_decompress_ptr cinfo);
void (*finish_input_pass) (j_decompress_ptr cinfo);
/* State variables made visible to other modules */
boolean has_multiple_scans; /* True if file has multiple scans */
boolean eoi_reached; /* True when EOI has been consumed */
};
/* Main buffer control (downsampled-data buffer) */
struct jpeg_d_main_controller {
void (*start_pass) (j_decompress_ptr cinfo, J_BUF_MODE pass_mode);
void (*process_data) (j_decompress_ptr cinfo, JSAMPARRAY output_buf,
JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail);
#ifdef WITH_12BIT
void (*process_data_12) (j_decompress_ptr cinfo, J12SAMPARRAY output_buf,
JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail);
#endif
};
/* Coefficient buffer control */
struct jpeg_d_coef_controller {
void (*start_input_pass) (j_decompress_ptr cinfo);
int (*consume_data) (j_decompress_ptr cinfo);
void (*start_output_pass) (j_decompress_ptr cinfo);
int (*decompress_data) (j_decompress_ptr cinfo, JSAMPIMAGE output_buf);
#ifdef WITH_12BIT
int (*decompress_data_12) (j_decompress_ptr cinfo, J12SAMPIMAGE output_buf);
#endif
/* Pointer to array of coefficient virtual arrays, or NULL if none */
jvirt_barray_ptr *coef_arrays;
};
/* Decompression postprocessing (color quantization buffer control) */
struct jpeg_d_post_controller {
void (*start_pass) (j_decompress_ptr cinfo, J_BUF_MODE pass_mode);
void (*post_process_data) (j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail);
#ifdef WITH_12BIT
void (*post_process_data_12) (j_decompress_ptr cinfo, J12SAMPIMAGE input_buf,
JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
J12SAMPARRAY output_buf,
JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail);
#endif
};
/* Marker reading & parsing */
struct jpeg_marker_reader {
void (*reset_marker_reader) (j_decompress_ptr cinfo);
/* Read markers until SOS or EOI.
* Returns same codes as are defined for jpeg_consume_input:
* JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
*/
int (*read_markers) (j_decompress_ptr cinfo);
/* Read a restart marker --- exported for use by entropy decoder only */
jpeg_marker_parser_method read_restart_marker;
/* State of marker reader --- nominally internal, but applications
* supplying COM or APPn handlers might like to know the state.
*/
boolean saw_SOI; /* found SOI? */
boolean saw_SOF; /* found SOF? */
int next_restart_num; /* next restart number expected (0-7) */
unsigned int discarded_bytes; /* # of bytes skipped looking for a marker */
};
/* Entropy decoding */
struct jpeg_entropy_decoder {
void (*start_pass) (j_decompress_ptr cinfo);
boolean (*decode_mcu) (j_decompress_ptr cinfo, JBLOCKROW *MCU_data);
/* This is here to share code between baseline and progressive decoders; */
/* other modules probably should not use it */
boolean insufficient_data; /* set TRUE after emitting warning */
};
/* Inverse DCT (also performs dequantization) */
typedef void (*inverse_DCT_method_ptr) (j_decompress_ptr cinfo,
jpeg_component_info *compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf,
JDIMENSION output_col);
#ifdef WITH_12BIT
typedef void (*inverse_DCT_12_method_ptr) (j_decompress_ptr cinfo,
jpeg_component_info *compptr,
JCOEFPTR coef_block,
J12SAMPARRAY output_buf,
JDIMENSION output_col);
#endif
struct jpeg_inverse_dct {
void (*start_pass) (j_decompress_ptr cinfo);
/* It is useful to allow each component to have a separate IDCT method. */
inverse_DCT_method_ptr inverse_DCT[MAX_COMPONENTS];
#ifdef WITH_12BIT
inverse_DCT_12_method_ptr inverse_DCT_12[MAX_COMPONENTS];
#endif
};
/* Upsampling (note that upsampler must also call color converter) */
struct jpeg_upsampler {
void (*start_pass) (j_decompress_ptr cinfo);
void (*upsample) (j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail, JSAMPARRAY output_buf,
JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail);
#ifdef WITH_12BIT
void (*upsample_12) (j_decompress_ptr cinfo, J12SAMPIMAGE input_buf,
JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail, J12SAMPARRAY output_buf,
JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail);
#endif
boolean need_context_rows; /* TRUE if need rows above & below */
};
/* Colorspace conversion */
struct jpeg_color_deconverter {
void (*start_pass) (j_decompress_ptr cinfo);
void (*color_convert) (j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
JDIMENSION input_row, JSAMPARRAY output_buf,
int num_rows);
#ifdef WITH_12BIT
void (*color_convert_12) (j_decompress_ptr cinfo, J12SAMPIMAGE input_buf,
JDIMENSION input_row, J12SAMPARRAY output_buf,
int num_rows);
#endif
};
/* Color quantization or color precision reduction */
struct jpeg_color_quantizer {
void (*start_pass) (j_decompress_ptr cinfo, boolean is_pre_scan);
void (*color_quantize) (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
JSAMPARRAY output_buf, int num_rows);
#ifdef WITH_12BIT
void (*color_quantize_12) (j_decompress_ptr cinfo, J12SAMPARRAY input_buf,
J12SAMPARRAY output_buf, int num_rows);
#endif
void (*finish_pass) (j_decompress_ptr cinfo);
void (*new_color_map) (j_decompress_ptr cinfo);
};
/* Miscellaneous useful macros */
#undef MAX
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#undef MIN
#define MIN(a, b) ((a) < (b) ? (a) : (b))
/* We assume that right shift corresponds to signed division by 2 with
* rounding towards minus infinity. This is correct for typical "arithmetic
* shift" instructions that shift in copies of the sign bit. But some
* C compilers implement >> with an unsigned shift. For these machines you
* must define RIGHT_SHIFT_IS_UNSIGNED.
* RIGHT_SHIFT provides a proper signed right shift of a JLONG quantity.
* It is only applied with constant shift counts. SHIFT_TEMPS must be
* included in the variables of any routine using RIGHT_SHIFT.
*/
#ifdef RIGHT_SHIFT_IS_UNSIGNED
#define SHIFT_TEMPS JLONG shift_temp;
#define RIGHT_SHIFT(x, shft) \
((shift_temp = (x)) < 0 ? \
(shift_temp >> (shft)) | ((~((JLONG)0)) << (32 - (shft))) : \
(shift_temp >> (shft)))
#else
#define SHIFT_TEMPS
#define RIGHT_SHIFT(x, shft) ((x) >> (shft))
#endif
/* Compression module initialization routines */
EXTERN(void) jinit_compress_master(j_compress_ptr cinfo);
EXTERN(void) jinit_c_master_control(j_compress_ptr cinfo,
boolean transcode_only);
EXTERN(void) jinit_c_main_controller(j_compress_ptr cinfo,
boolean need_full_buffer);
EXTERN(void) jinit_c_prep_controller(j_compress_ptr cinfo,
boolean need_full_buffer);
EXTERN(void) jinit_c_coef_controller(j_compress_ptr cinfo,
boolean need_full_buffer);
EXTERN(void) jinit_color_converter(j_compress_ptr cinfo);
EXTERN(void) jinit_downsampler(j_compress_ptr cinfo);
EXTERN(void) jinit_forward_dct(j_compress_ptr cinfo);
EXTERN(void) jinit_huff_encoder(j_compress_ptr cinfo);
EXTERN(void) jinit_phuff_encoder(j_compress_ptr cinfo);
EXTERN(void) jinit_arith_encoder(j_compress_ptr cinfo);
EXTERN(void) jinit_marker_writer(j_compress_ptr cinfo);
#ifdef WITH_12BIT
EXTERN(void) j12init_c_main_controller(j_compress_ptr cinfo,
boolean need_full_buffer);
EXTERN(void) j12init_c_prep_controller(j_compress_ptr cinfo,
boolean need_full_buffer);
EXTERN(void) j12init_c_coef_controller(j_compress_ptr cinfo,
boolean need_full_buffer);
EXTERN(void) j12init_color_converter(j_compress_ptr cinfo);
EXTERN(void) j12init_downsampler(j_compress_ptr cinfo);
EXTERN(void) j12init_forward_dct(j_compress_ptr cinfo);
#endif
/* Decompression module initialization routines */
EXTERN(void) jinit_master_decompress(j_decompress_ptr cinfo);
EXTERN(void) jinit_d_main_controller(j_decompress_ptr cinfo,
boolean need_full_buffer);
EXTERN(void) jinit_d_coef_controller(j_decompress_ptr cinfo,
boolean need_full_buffer);
EXTERN(void) jinit_d_post_controller(j_decompress_ptr cinfo,
boolean need_full_buffer);
EXTERN(void) jinit_input_controller(j_decompress_ptr cinfo);
EXTERN(void) jinit_marker_reader(j_decompress_ptr cinfo);
EXTERN(void) jinit_huff_decoder(j_decompress_ptr cinfo);
EXTERN(void) jinit_phuff_decoder(j_decompress_ptr cinfo);
EXTERN(void) jinit_arith_decoder(j_decompress_ptr cinfo);
EXTERN(void) jinit_inverse_dct(j_decompress_ptr cinfo);
EXTERN(void) jinit_upsampler(j_decompress_ptr cinfo);
EXTERN(void) jinit_color_deconverter(j_decompress_ptr cinfo);
EXTERN(void) jinit_1pass_quantizer(j_decompress_ptr cinfo);
EXTERN(void) jinit_2pass_quantizer(j_decompress_ptr cinfo);
EXTERN(void) jinit_merged_upsampler(j_decompress_ptr cinfo);
#ifdef WITH_12BIT
EXTERN(void) j12init_d_main_controller(j_decompress_ptr cinfo,
boolean need_full_buffer);
EXTERN(void) j12init_d_coef_controller(j_decompress_ptr cinfo,
boolean need_full_buffer);
EXTERN(void) j12init_d_post_controller(j_decompress_ptr cinfo,
boolean need_full_buffer);
EXTERN(void) j12init_inverse_dct(j_decompress_ptr cinfo);
EXTERN(void) j12init_upsampler(j_decompress_ptr cinfo);
EXTERN(void) j12init_color_deconverter(j_decompress_ptr cinfo);
EXTERN(void) j12init_1pass_quantizer(j_decompress_ptr cinfo);
EXTERN(void) j12init_2pass_quantizer(j_decompress_ptr cinfo);
EXTERN(void) j12init_merged_upsampler(j_decompress_ptr cinfo);
#endif
/* Memory manager initialization */
EXTERN(void) jinit_memory_mgr(j_common_ptr cinfo);
/* Utility routines in jutils.c */
EXTERN(long) jdiv_round_up(long a, long b);
EXTERN(long) jround_up(long a, long b);
EXTERN(void) jcopy_sample_rows(JSAMPARRAY input_array, int source_row,
JSAMPARRAY output_array, int dest_row,
int num_rows, JDIMENSION num_cols);
#ifdef WITH_12BIT
EXTERN(void) j12copy_sample_rows(J12SAMPARRAY input_array, int source_row,
J12SAMPARRAY output_array, int dest_row,
int num_rows, JDIMENSION num_cols);
#endif
EXTERN(void) jcopy_block_row(JBLOCKROW input_row, JBLOCKROW output_row,
JDIMENSION num_blocks);
EXTERN(void) jzero_far(void *target, size_t bytestozero);
/* Constant tables in jutils.c */
#if 0 /* This table is not actually needed in v6a */
extern const int jpeg_zigzag_order[]; /* natural coef order to zigzag order */
#endif
extern const int jpeg_natural_order[]; /* zigzag coef order to natural order */
/* Arithmetic coding probability estimation tables in jaricom.c */
extern const JLONG jpeg_aritab[];
Reference in New Issue View Git Blame Copy Permalink