third_party/libjpeg/jpegint.h

   1 /*
   2  * jpegint.h
   3  *
   4  * Copyright (C) 1991-1997, Thomas G. Lane.
   5  * This file is part of the Independent JPEG Group's software.
   6  * For conditions of distribution and use, see the accompanying README file.
   7  *
   8  * This file provides common declarations for the various JPEG modules.
   9  * These declarations are considered internal to the JPEG library; most
  10  * applications using the library shouldn't need to include this file.
  11  */
  12
  13
  14 /* Declarations for both compression & decompression */
  15
  16 typedef enum {                  /* Operating modes for buffer controllers */
  17         JBUF_PASS_THRU,         /* Plain stripwise operation */
  18         /* Remaining modes require a full-image buffer to have been created */
  19         JBUF_SAVE_SOURCE,       /* Run source subobject only, save output */
  20         JBUF_CRANK_DEST,        /* Run dest subobject only, using saved data */
  21         JBUF_SAVE_AND_PASS      /* Run both subobjects, save output */
  22 } J_BUF_MODE;
  23
  24 /* Values of global_state field (jdapi.c has some dependencies on ordering!) */
  25 #define CSTATE_START    100     /* after create_compress */
  26 #define CSTATE_SCANNING 101     /* start_compress done, write_scanlines OK */
  27 #define CSTATE_RAW_OK   102     /* start_compress done, write_raw_data OK */
  28 #define CSTATE_WRCOEFS  103     /* jpeg_write_coefficients done */
  29 #define DSTATE_START    200     /* after create_decompress */
  30 #define DSTATE_INHEADER 201     /* reading header markers, no SOS yet */
  31 #define DSTATE_READY    202     /* found SOS, ready for start_decompress */
  32 #define DSTATE_PRELOAD  203     /* reading multiscan file in start_decompress*/
  33 #define DSTATE_PRESCAN  204     /* performing dummy pass for 2-pass quant */
  34 #define DSTATE_SCANNING 205     /* start_decompress done, read_scanlines OK */
  35 #define DSTATE_RAW_OK   206     /* start_decompress done, read_raw_data OK */
  36 #define DSTATE_BUFIMAGE 207     /* expecting jpeg_start_output */
  37 #define DSTATE_BUFPOST  208     /* looking for SOS/EOI in jpeg_finish_output */
  38 #define DSTATE_RDCOEFS  209     /* reading file in jpeg_read_coefficients */
  39 #define DSTATE_STOPPING 210     /* looking for EOI in jpeg_finish_decompress */
  40
  41
  42 /* Declarations for compression modules */
  43
  44 /* Master control module */
  45 struct jpeg_comp_master {
  46   JMETHOD(void, prepare_for_pass, (j_compress_ptr cinfo));
  47   JMETHOD(void, pass_startup, (j_compress_ptr cinfo));
  48   JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
  49
  50   /* State variables made visible to other modules */
  51   boolean call_pass_startup;    /* True if pass_startup must be called */
  52   boolean is_last_pass;         /* True during last pass */
  53 };
  54
  55 /* Main buffer control (downsampled-data buffer) */
  56 struct jpeg_c_main_controller {
  57   JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
  58   JMETHOD(void, process_data, (j_compress_ptr cinfo,
  59                                JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
  60                                JDIMENSION in_rows_avail));
  61 };
  62
  63 /* Compression preprocessing (downsampling input buffer control) */
  64 struct jpeg_c_prep_controller {
  65   JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
  66   JMETHOD(void, pre_process_data, (j_compress_ptr cinfo,
  67                                    JSAMPARRAY input_buf,
  68                                    JDIMENSION *in_row_ctr,
  69                                    JDIMENSION in_rows_avail,
  70                                    JSAMPIMAGE output_buf,
  71                                    JDIMENSION *out_row_group_ctr,
  72                                    JDIMENSION out_row_groups_avail));
  73 };
  74
  75 /* Coefficient buffer control */
  76 struct jpeg_c_coef_controller {
  77   JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
  78   JMETHOD(boolean, compress_data, (j_compress_ptr cinfo,
  79                                    JSAMPIMAGE input_buf));
  80 };
  81
  82 /* Colorspace conversion */
  83 struct jpeg_color_converter {
  84   JMETHOD(void, start_pass, (j_compress_ptr cinfo));
  85   JMETHOD(void, color_convert, (j_compress_ptr cinfo,
  86                                 JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
  87                                 JDIMENSION output_row, int num_rows));
  88 };
  89
  90 /* Downsampling */
  91 struct jpeg_downsampler {
  92   JMETHOD(void, start_pass, (j_compress_ptr cinfo));
  93   JMETHOD(void, downsample, (j_compress_ptr cinfo,
  94                              JSAMPIMAGE input_buf, JDIMENSION in_row_index,
  95                              JSAMPIMAGE output_buf,
  96                              JDIMENSION out_row_group_index));
  97
  98   boolean need_context_rows;    /* TRUE if need rows above & below */
  99 };
 100
 101 /* Forward DCT (also controls coefficient quantization) */
 102 struct jpeg_forward_dct {
 103   JMETHOD(void, start_pass, (j_compress_ptr cinfo));
 104   /* perhaps this should be an array??? */
 105   JMETHOD(void, forward_DCT, (j_compress_ptr cinfo,
 106                               jpeg_component_info * compptr,
 107                               JSAMPARRAY sample_data, JBLOCKROW coef_blocks,
 108                               JDIMENSION start_row, JDIMENSION start_col,
 109                               JDIMENSION num_blocks));
 110 };
 111
 112 /* Entropy encoding */
 113 struct jpeg_entropy_encoder {
 114   JMETHOD(void, start_pass, (j_compress_ptr cinfo, boolean gather_statistics));
 115   JMETHOD(boolean, encode_mcu, (j_compress_ptr cinfo, JBLOCKROW *MCU_data));
 116   JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
 117 };
 118
 119 /* Marker writing */
 120 struct jpeg_marker_writer {
 121   JMETHOD(void, write_file_header, (j_compress_ptr cinfo));
 122   JMETHOD(void, write_frame_header, (j_compress_ptr cinfo));
 123   JMETHOD(void, write_scan_header, (j_compress_ptr cinfo));
 124   JMETHOD(void, write_file_trailer, (j_compress_ptr cinfo));
 125   JMETHOD(void, write_tables_only, (j_compress_ptr cinfo));
 126   /* These routines are exported to allow insertion of extra markers */
 127   /* Probably only COM and APPn markers should be written this way */
 128   JMETHOD(void, write_marker_header, (j_compress_ptr cinfo, int marker,
 129                                       unsigned int datalen));
 130   JMETHOD(void, write_marker_byte, (j_compress_ptr cinfo, int val));
 131 };
 132
 133
 134 /* Declarations for decompression modules */
 135
 136 /* Master control module */
 137 struct jpeg_decomp_master {
 138   JMETHOD(void, prepare_for_output_pass, (j_decompress_ptr cinfo));
 139   JMETHOD(void, finish_output_pass, (j_decompress_ptr cinfo));
 140
 141   /* State variables made visible to other modules */
 142   boolean is_dummy_pass;        /* True during 1st pass for 2-pass quant */
 143 };
 144
 145 /* Input control module */
 146 struct jpeg_input_controller {
 147   JMETHOD(int, consume_input, (j_decompress_ptr cinfo));
 148   JMETHOD(void, reset_input_controller, (j_decompress_ptr cinfo));
 149   JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
 150   JMETHOD(void, finish_input_pass, (j_decompress_ptr cinfo));
 151
 152   /* State variables made visible to other modules */
 153   boolean has_multiple_scans;   /* True if file has multiple scans */
 154   boolean eoi_reached;          /* True when EOI has been consumed */
 155 };
 156
 157 /* Main buffer control (downsampled-data buffer) */
 158 struct jpeg_d_main_controller {
 159   JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
 160   JMETHOD(void, process_data, (j_decompress_ptr cinfo,
 161                                JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
 162                                JDIMENSION out_rows_avail));
 163 };
 164
 165 /* Coefficient buffer control */
 166 struct jpeg_d_coef_controller {
 167   JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
 168   JMETHOD(int, consume_data, (j_decompress_ptr cinfo));
 169   JMETHOD(void, start_output_pass, (j_decompress_ptr cinfo));
 170   JMETHOD(int, decompress_data, (j_decompress_ptr cinfo,
 171                                  JSAMPIMAGE output_buf));
 172   /* Pointer to array of coefficient virtual arrays, or NULL if none */
 173   jvirt_barray_ptr *coef_arrays;
 174 };
 175
 176 /* Decompression postprocessing (color quantization buffer control) */
 177 struct jpeg_d_post_controller {
 178   JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
 179   JMETHOD(void, post_process_data, (j_decompress_ptr cinfo,
 180                                     JSAMPIMAGE input_buf,
 181                                     JDIMENSION *in_row_group_ctr,
 182                                     JDIMENSION in_row_groups_avail,
 183                                     JSAMPARRAY output_buf,
 184                                     JDIMENSION *out_row_ctr,
 185                                     JDIMENSION out_rows_avail));
 186 };
 187
 188 /* Marker reading & parsing */
 189 struct jpeg_marker_reader {
 190   JMETHOD(void, reset_marker_reader, (j_decompress_ptr cinfo));
 191   /* Read markers until SOS or EOI.
 192    * Returns same codes as are defined for jpeg_consume_input:
 193    * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
 194    */
 195   JMETHOD(int, read_markers, (j_decompress_ptr cinfo));
 196   /* Read a restart marker --- exported for use by entropy decoder only */
 197   jpeg_marker_parser_method read_restart_marker;
 198
 199   /* State of marker reader --- nominally internal, but applications
 200    * supplying COM or APPn handlers might like to know the state.
 201    */
 202   boolean saw_SOI;              /* found SOI? */
 203   boolean saw_SOF;              /* found SOF? */
 204   int next_restart_num;         /* next restart number expected (0-7) */
 205   unsigned int discarded_bytes; /* # of bytes skipped looking for a marker */
 206 };
 207
 208 /* Entropy decoding */
 209 struct jpeg_entropy_decoder {
 210   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
 211   JMETHOD(boolean, decode_mcu, (j_decompress_ptr cinfo,
 212                                 JBLOCKROW *MCU_data));
 213
 214   /* This is here to share code between baseline and progressive decoders; */
 215   /* other modules probably should not use it */
 216   boolean insufficient_data;    /* set TRUE after emitting warning */
 217 };
 218
 219 /* Inverse DCT (also performs dequantization) */
 220 typedef JMETHOD(void, inverse_DCT_method_ptr,
 221                 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
 222                  JCOEFPTR coef_block,
 223                  JSAMPARRAY output_buf, JDIMENSION output_col));
 224
 225 struct jpeg_inverse_dct {
 226   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
 227   /* It is useful to allow each component to have a separate IDCT method. */
 228   inverse_DCT_method_ptr inverse_DCT[MAX_COMPONENTS];
 229 };
 230
 231 /* Upsampling (note that upsampler must also call color converter) */
 232 struct jpeg_upsampler {
 233   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
 234   JMETHOD(void, upsample, (j_decompress_ptr cinfo,
 235                            JSAMPIMAGE input_buf,
 236                            JDIMENSION *in_row_group_ctr,
 237                            JDIMENSION in_row_groups_avail,
 238                            JSAMPARRAY output_buf,
 239                            JDIMENSION *out_row_ctr,
 240                            JDIMENSION out_rows_avail));
 241
 242   boolean need_context_rows;    /* TRUE if need rows above & below */
 243 };
 244
 245 /* Colorspace conversion */
 246 struct jpeg_color_deconverter {
 247   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
 248   JMETHOD(void, color_convert, (j_decompress_ptr cinfo,
 249                                 JSAMPIMAGE input_buf, JDIMENSION input_row,
 250                                 JSAMPARRAY output_buf, int num_rows));
 251 };
 252
 253 /* Color quantization or color precision reduction */
 254 struct jpeg_color_quantizer {
 255   JMETHOD(void, start_pass, (j_decompress_ptr cinfo, boolean is_pre_scan));
 256   JMETHOD(void, color_quantize, (j_decompress_ptr cinfo,
 257                                  JSAMPARRAY input_buf, JSAMPARRAY output_buf,
 258                                  int num_rows));
 259   JMETHOD(void, finish_pass, (j_decompress_ptr cinfo));
 260   JMETHOD(void, new_color_map, (j_decompress_ptr cinfo));
 261 };
 262
 263
 264 /* Miscellaneous useful macros */
 265
 266 #undef MAX
 267 #define MAX(a,b)        ((a) > (b) ? (a) : (b))
 268 #undef MIN
 269 #define MIN(a,b)        ((a) < (b) ? (a) : (b))
 270
 271
 272 /* We assume that right shift corresponds to signed division by 2 with
 273  * rounding towards minus infinity.  This is correct for typical "arithmetic
 274  * shift" instructions that shift in copies of the sign bit.  But some
 275  * C compilers implement >> with an unsigned shift.  For these machines you
 276  * must define RIGHT_SHIFT_IS_UNSIGNED.
 277  * RIGHT_SHIFT provides a proper signed right shift of an INT32 quantity.
 278  * It is only applied with constant shift counts.  SHIFT_TEMPS must be
 279  * included in the variables of any routine using RIGHT_SHIFT.
 280  */
 281
 282 #ifdef RIGHT_SHIFT_IS_UNSIGNED
 283 #define SHIFT_TEMPS     INT32 shift_temp;
 284 #define RIGHT_SHIFT(x,shft)  \
 285         ((shift_temp = (x)) < 0 ? \
 286          (shift_temp >> (shft)) | ((~((INT32) 0)) << (32-(shft))) : \
 287          (shift_temp >> (shft)))
 288 #else
 289 #define SHIFT_TEMPS
 290 #define RIGHT_SHIFT(x,shft)     ((x) >> (shft))
 291 #endif
 292
 293
 294 /* Short forms of external names for systems with brain-damaged linkers. */
 295
 296 #ifdef NEED_SHORT_EXTERNAL_NAMES
 297 #define jinit_compress_master   jICompress
 298 #define jinit_c_master_control  jICMaster
 299 #define jinit_c_main_controller jICMainC
 300 #define jinit_c_prep_controller jICPrepC
 301 #define jinit_c_coef_controller jICCoefC
 302 #define jinit_color_converter   jICColor
 303 #define jinit_downsampler       jIDownsampler
 304 #define jinit_forward_dct       jIFDCT
 305 #define jinit_huff_encoder      jIHEncoder
 306 #define jinit_phuff_encoder     jIPHEncoder
 307 #define jinit_marker_writer     jIMWriter
 308 #define jinit_master_decompress jIDMaster
 309 #define jinit_d_main_controller jIDMainC
 310 #define jinit_d_coef_controller jIDCoefC
 311 #define jinit_d_post_controller jIDPostC
 312 #define jinit_input_controller  jIInCtlr
 313 #define jinit_marker_reader     jIMReader
 314 #define jinit_huff_decoder      jIHDecoder
 315 #define jinit_phuff_decoder     jIPHDecoder
 316 #define jinit_inverse_dct       jIIDCT
 317 #define jinit_upsampler         jIUpsampler
 318 #define jinit_color_deconverter jIDColor
 319 #define jinit_1pass_quantizer   jI1Quant
 320 #define jinit_2pass_quantizer   jI2Quant
 321 #define jinit_merged_upsampler  jIMUpsampler
 322 #define jinit_memory_mgr        jIMemMgr
 323 #define jdiv_round_up           jDivRound
 324 #define jround_up               jRound
 325 #define jcopy_sample_rows       jCopySamples
 326 #define jcopy_block_row         jCopyBlocks
 327 #define jzero_far               jZeroFar
 328 #define jpeg_zigzag_order       jZIGTable
 329 #define jpeg_natural_order      jZAGTable
 330 #endif /* NEED_SHORT_EXTERNAL_NAMES */
 331
 332
 333 /* Compression module initialization routines */
 334 EXTERN(void) jinit_compress_master JPP((j_compress_ptr cinfo));
 335 EXTERN(void) jinit_c_master_control JPP((j_compress_ptr cinfo,
 336                                          boolean transcode_only));
 337 EXTERN(void) jinit_c_main_controller JPP((j_compress_ptr cinfo,
 338                                           boolean need_full_buffer));
 339 EXTERN(void) jinit_c_prep_controller JPP((j_compress_ptr cinfo,
 340                                           boolean need_full_buffer));
 341 EXTERN(void) jinit_c_coef_controller JPP((j_compress_ptr cinfo,
 342                                           boolean need_full_buffer));
 343 EXTERN(void) jinit_color_converter JPP((j_compress_ptr cinfo));
 344 EXTERN(void) jinit_downsampler JPP((j_compress_ptr cinfo));
 345 EXTERN(void) jinit_forward_dct JPP((j_compress_ptr cinfo));
 346 EXTERN(void) jinit_huff_encoder JPP((j_compress_ptr cinfo));
 347 EXTERN(void) jinit_phuff_encoder JPP((j_compress_ptr cinfo));
 348 EXTERN(void) jinit_marker_writer JPP((j_compress_ptr cinfo));
 349 /* Decompression module initialization routines */
 350 EXTERN(void) jinit_master_decompress JPP((j_decompress_ptr cinfo));
 351 EXTERN(void) jinit_d_main_controller JPP((j_decompress_ptr cinfo,
 352                                           boolean need_full_buffer));
 353 EXTERN(void) jinit_d_coef_controller JPP((j_decompress_ptr cinfo,
 354                                           boolean need_full_buffer));
 355 EXTERN(void) jinit_d_post_controller JPP((j_decompress_ptr cinfo,
 356                                           boolean need_full_buffer));
 357 EXTERN(void) jinit_input_controller JPP((j_decompress_ptr cinfo));
 358 EXTERN(void) jinit_marker_reader JPP((j_decompress_ptr cinfo));
 359 EXTERN(void) jinit_huff_decoder JPP((j_decompress_ptr cinfo));
 360 EXTERN(void) jinit_phuff_decoder JPP((j_decompress_ptr cinfo));
 361 EXTERN(void) jinit_inverse_dct JPP((j_decompress_ptr cinfo));
 362 EXTERN(void) jinit_upsampler JPP((j_decompress_ptr cinfo));
 363 EXTERN(void) jinit_color_deconverter JPP((j_decompress_ptr cinfo));
 364 EXTERN(void) jinit_1pass_quantizer JPP((j_decompress_ptr cinfo));
 365 EXTERN(void) jinit_2pass_quantizer JPP((j_decompress_ptr cinfo));
 366 EXTERN(void) jinit_merged_upsampler JPP((j_decompress_ptr cinfo));
 367 /* Memory manager initialization */
 368 EXTERN(void) jinit_memory_mgr JPP((j_common_ptr cinfo));
 369
 370 /* Utility routines in jutils.c */
 371 EXTERN(long) jdiv_round_up JPP((long a, long b));
 372 EXTERN(long) jround_up JPP((long a, long b));
 373 EXTERN(void) jcopy_sample_rows JPP((JSAMPARRAY input_array, int source_row,
 374                                     JSAMPARRAY output_array, int dest_row,
 375                                     int num_rows, JDIMENSION num_cols));
 376 EXTERN(void) jcopy_block_row JPP((JBLOCKROW input_row, JBLOCKROW output_row,
 377                                   JDIMENSION num_blocks));
 378 EXTERN(void) jzero_far JPP((void FAR * target, size_t bytestozero));
 379 /* Constant tables in jutils.c */
 380 #if 0                           /* This table is not actually needed in v6a */
 381 extern const int jpeg_zigzag_order[]; /* natural coef order to zigzag order */
 382 #endif
 383 extern const int jpeg_natural_order[]; /* zigzag coef order to natural order */
 384
 385 /* Suppress undefined-structure complaints if necessary. */
 386
 387 #ifdef INCOMPLETE_TYPES_BROKEN
 388 #ifndef AM_MEMORY_MANAGER       /* only jmemmgr.c defines these */
 389 struct jvirt_sarray_control { long dummy; };
 390 struct jvirt_barray_control { long dummy; };
 391 #endif
 392 #endif /* INCOMPLETE_TYPES_BROKEN */