jpegint.h 15.2 KB
Newer Older
Erwan Croze's avatar
Erwan Croze committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368
/*
 * 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, D. R. Commander.
 * Copyright (C) 2015, Google, Inc.
 * 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;


/*
 * 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);
};

/* 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);
};

/* 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);
};

/* 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);
};

/* 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);

  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);
};

/* 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;
};

/* 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);
};

/* 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);
  /* 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);
};

/* 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);

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];
};

/* 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);

  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);
};

/* 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);
  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);
/* 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);
/* 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);
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[];

/* Suppress undefined-structure complaints if necessary. */

#ifdef INCOMPLETE_TYPES_BROKEN
#ifndef AM_MEMORY_MANAGER       /* only jmemmgr.c defines these */
struct jvirt_sarray_control { long dummy; };
struct jvirt_barray_control { long dummy; };
#endif
#endif /* INCOMPLETE_TYPES_BROKEN */