src/jpeg/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 #if defined(__VISAGECPP__)
 146 /* Visual Age fixups for multiple declarations */
 147 #  define start_input_pass   start_input_pass2 /* already in jcmaint.c */
 148 #endif
 149
 150 /* Input control module */
 151 struct jpeg_input_controller {
 152   JMETHOD(int, consume_input, (j_decompress_ptr cinfo));
 153   JMETHOD(void, reset_input_controller, (j_decompress_ptr cinfo));
 154   JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
 155   JMETHOD(void, finish_input_pass, (j_decompress_ptr cinfo));
 156
 157   /* State variables made visible to other modules */
 158   boolean has_multiple_scans;   /* True if file has multiple scans */
 159   boolean eoi_reached;          /* True when EOI has been consumed */
 160 };
 161
 162 #if defined(__VISAGECPP__)
 163 #  ifdef start_input_pass2
 164 #   undef start_input_pass2
 165 #  endif
 166 #endif
 167
 168 /* Main buffer control (downsampled-data buffer) */
 169 struct jpeg_d_main_controller {
 170   JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
 171   JMETHOD(void, process_data, (j_decompress_ptr cinfo,
 172                                JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
 173                                JDIMENSION out_rows_avail));
 174 };
 175
 176 /* Coefficient buffer control */
 177 struct jpeg_d_coef_controller {
 178   JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
 179   JMETHOD(int, consume_data, (j_decompress_ptr cinfo));
 180   JMETHOD(void, start_output_pass, (j_decompress_ptr cinfo));
 181   JMETHOD(int, decompress_data, (j_decompress_ptr cinfo,
 182                                  JSAMPIMAGE output_buf));
 183   /* Pointer to array of coefficient virtual arrays, or NULL if none */
 184   jvirt_barray_ptr *coef_arrays;
 185 };
 186
 187 /* Decompression postprocessing (color quantization buffer control) */
 188 struct jpeg_d_post_controller {
 189   JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
 190   JMETHOD(void, post_process_data, (j_decompress_ptr cinfo,
 191                                     JSAMPIMAGE input_buf,
 192                                     JDIMENSION *in_row_group_ctr,
 193                                     JDIMENSION in_row_groups_avail,
 194                                     JSAMPARRAY output_buf,
 195                                     JDIMENSION *out_row_ctr,
 196                                     JDIMENSION out_rows_avail));
 197 };
 198
 199 /* Marker reading & parsing */
 200 struct jpeg_marker_reader {
 201   JMETHOD(void, reset_marker_reader, (j_decompress_ptr cinfo));
 202   /* Read markers until SOS or EOI.
 203    * Returns same codes as are defined for jpeg_consume_input:
 204    * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
 205    */
 206   JMETHOD(int, read_markers, (j_decompress_ptr cinfo));
 207   /* Read a restart marker --- exported for use by entropy decoder only */
 208   jpeg_marker_parser_method read_restart_marker;
 209
 210   /* State of marker reader --- nominally internal, but applications
 211    * supplying COM or APPn handlers might like to know the state.
 212    */
 213   boolean saw_SOI;              /* found SOI? */
 214   boolean saw_SOF;              /* found SOF? */
 215   int next_restart_num;         /* next restart number expected (0-7) */
 216   unsigned int discarded_bytes; /* # of bytes skipped looking for a marker */
 217 };
 218
 219 /* Entropy decoding */
 220 struct jpeg_entropy_decoder {
 221   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
 222   JMETHOD(boolean, decode_mcu, (j_decompress_ptr cinfo,
 223                                 JBLOCKROW *MCU_data));
 224
 225   /* This is here to share code between baseline and progressive decoders; */
 226   /* other modules probably should not use it */
 227   boolean insufficient_data;    /* set TRUE after emitting warning */
 228 };
 229
 230 /* Inverse DCT (also performs dequantization) */
 231 typedef JMETHOD(void, inverse_DCT_method_ptr,
 232                 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
 233                  JCOEFPTR coef_block,
 234                  JSAMPARRAY output_buf, JDIMENSION output_col));
 235
 236 struct jpeg_inverse_dct {
 237   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
 238   /* It is useful to allow each component to have a separate IDCT method. */
 239   inverse_DCT_method_ptr inverse_DCT[MAX_COMPONENTS];
 240 };
 241
 242 /* Upsampling (note that upsampler must also call color converter) */
 243 struct jpeg_upsampler {
 244   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
 245   JMETHOD(void, upsample, (j_decompress_ptr cinfo,
 246                            JSAMPIMAGE input_buf,
 247                            JDIMENSION *in_row_group_ctr,
 248                            JDIMENSION in_row_groups_avail,
 249                            JSAMPARRAY output_buf,
 250                            JDIMENSION *out_row_ctr,
 251                            JDIMENSION out_rows_avail));
 252
 253   boolean need_context_rows;    /* TRUE if need rows above & below */
 254 };
 255
 256 /* Colorspace conversion */
 257 struct jpeg_color_deconverter {
 258   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
 259   JMETHOD(void, color_convert, (j_decompress_ptr cinfo,
 260                                 JSAMPIMAGE input_buf, JDIMENSION input_row,
 261                                 JSAMPARRAY output_buf, int num_rows));
 262 };
 263
 264 /* Color quantization or color precision reduction */
 265 struct jpeg_color_quantizer {
 266   JMETHOD(void, start_pass, (j_decompress_ptr cinfo, boolean is_pre_scan));
 267   JMETHOD(void, color_quantize, (j_decompress_ptr cinfo,
 268                                  JSAMPARRAY input_buf, JSAMPARRAY output_buf,
 269                                  int num_rows));
 270   JMETHOD(void, finish_pass, (j_decompress_ptr cinfo));
 271   JMETHOD(void, new_color_map, (j_decompress_ptr cinfo));
 272 };
 273
 274
 275 /* Miscellaneous useful macros */
 276
 277 #undef MAX
 278 #define MAX(a,b)        ((a) > (b) ? (a) : (b))
 279 #undef MIN
 280 #define MIN(a,b)        ((a) < (b) ? (a) : (b))
 281
 282
 283 /* We assume that right shift corresponds to signed division by 2 with
 284  * rounding towards minus infinity.  This is correct for typical "arithmetic
 285  * shift" instructions that shift in copies of the sign bit.  But some
 286  * C compilers implement >> with an unsigned shift.  For these machines you
 287  * must define RIGHT_SHIFT_IS_UNSIGNED.
 288  * RIGHT_SHIFT provides a proper signed right shift of an INT32 quantity.
 289  * It is only applied with constant shift counts.  SHIFT_TEMPS must be
 290  * included in the variables of any routine using RIGHT_SHIFT.
 291  */
 292
 293 #ifdef RIGHT_SHIFT_IS_UNSIGNED
 294 #define SHIFT_TEMPS     JPEG_INT32 shift_temp;
 295 #define RIGHT_SHIFT(x,shft)  \
 296         ((shift_temp = (x)) < 0 ? \
 297          (shift_temp >> (shft)) | ((~((JPEG_INT32) 0)) << (32-(shft))) : \
 298          (shift_temp >> (shft)))
 299 #else
 300 #define SHIFT_TEMPS
 301 #define RIGHT_SHIFT(x,shft)     ((x) >> (shft))
 302 #endif
 303
 304
 305 /* Short forms of external names for systems with brain-damaged linkers. */
 306
 307 #ifdef NEED_SHORT_EXTERNAL_NAMES
 308 #define jinit_compress_master   jICompress
 309 #define jinit_c_master_control  jICMaster
 310 #define jinit_c_main_controller jICMainC
 311 #define jinit_c_prep_controller jICPrepC
 312 #define jinit_c_coef_controller jICCoefC
 313 #define jinit_color_converter   jICColor
 314 #define jinit_downsampler       jIDownsampler
 315 #define jinit_forward_dct       jIFDCT
 316 #define jinit_huff_encoder      jIHEncoder
 317 #define jinit_phuff_encoder     jIPHEncoder
 318 #define jinit_marker_writer     jIMWriter
 319 #define jinit_master_decompress jIDMaster
 320 #define jinit_d_main_controller jIDMainC
 321 #define jinit_d_coef_controller jIDCoefC
 322 #define jinit_d_post_controller jIDPostC
 323 #define jinit_input_controller  jIInCtlr
 324 #define jinit_marker_reader     jIMReader
 325 #define jinit_huff_decoder      jIHDecoder
 326 #define jinit_phuff_decoder     jIPHDecoder
 327 #define jinit_inverse_dct       jIIDCT
 328 #define jinit_upsampler         jIUpsampler
 329 #define jinit_color_deconverter jIDColor
 330 #define jinit_1pass_quantizer   jI1Quant
 331 #define jinit_2pass_quantizer   jI2Quant
 332 #define jinit_merged_upsampler  jIMUpsampler
 333 #define jinit_memory_mgr        jIMemMgr
 334 #define jdiv_round_up           jDivRound
 335 #define jround_up               jRound
 336 #define jcopy_sample_rows       jCopySamples
 337 #define jcopy_block_row         jCopyBlocks
 338 #define jzero_far               jZeroFar
 339 #define jpeg_zigzag_order       jZIGTable
 340 #define jpeg_natural_order      jZAGTable
 341 #endif /* NEED_SHORT_EXTERNAL_NAMES */
 342
 343
 344 /* Compression module initialization routines */
 345 EXTERN(void) jinit_compress_master JPP((j_compress_ptr cinfo));
 346 EXTERN(void) jinit_c_master_control JPP((j_compress_ptr cinfo,
 347                                          boolean transcode_only));
 348 EXTERN(void) jinit_c_main_controller JPP((j_compress_ptr cinfo,
 349                                           boolean need_full_buffer));
 350 EXTERN(void) jinit_c_prep_controller JPP((j_compress_ptr cinfo,
 351                                           boolean need_full_buffer));
 352 EXTERN(void) jinit_c_coef_controller JPP((j_compress_ptr cinfo,
 353                                           boolean need_full_buffer));
 354 EXTERN(void) jinit_color_converter JPP((j_compress_ptr cinfo));
 355 EXTERN(void) jinit_downsampler JPP((j_compress_ptr cinfo));
 356 EXTERN(void) jinit_forward_dct JPP((j_compress_ptr cinfo));
 357 EXTERN(void) jinit_huff_encoder JPP((j_compress_ptr cinfo));
 358 EXTERN(void) jinit_phuff_encoder JPP((j_compress_ptr cinfo));
 359 EXTERN(void) jinit_marker_writer JPP((j_compress_ptr cinfo));
 360 /* Decompression module initialization routines */
 361 EXTERN(void) jinit_master_decompress JPP((j_decompress_ptr cinfo));
 362 EXTERN(void) jinit_d_main_controller JPP((j_decompress_ptr cinfo,
 363                                           boolean need_full_buffer));
 364 EXTERN(void) jinit_d_coef_controller JPP((j_decompress_ptr cinfo,
 365                                           boolean need_full_buffer));
 366 EXTERN(void) jinit_d_post_controller JPP((j_decompress_ptr cinfo,
 367                                           boolean need_full_buffer));
 368 EXTERN(void) jinit_input_controller JPP((j_decompress_ptr cinfo));
 369 EXTERN(void) jinit_marker_reader JPP((j_decompress_ptr cinfo));
 370 EXTERN(void) jinit_huff_decoder JPP((j_decompress_ptr cinfo));
 371 EXTERN(void) jinit_phuff_decoder JPP((j_decompress_ptr cinfo));
 372 EXTERN(void) jinit_inverse_dct JPP((j_decompress_ptr cinfo));
 373 EXTERN(void) jinit_upsampler JPP((j_decompress_ptr cinfo));
 374 EXTERN(void) jinit_color_deconverter JPP((j_decompress_ptr cinfo));
 375 EXTERN(void) jinit_1pass_quantizer JPP((j_decompress_ptr cinfo));
 376 EXTERN(void) jinit_2pass_quantizer JPP((j_decompress_ptr cinfo));
 377 EXTERN(void) jinit_merged_upsampler JPP((j_decompress_ptr cinfo));
 378 /* Memory manager initialization */
 379 EXTERN(void) jinit_memory_mgr JPP((j_common_ptr cinfo));
 380
 381 /* Utility routines in jutils.c */
 382 EXTERN(long) jdiv_round_up JPP((long a, long b));
 383 EXTERN(long) jround_up JPP((long a, long b));
 384 EXTERN(void) jcopy_sample_rows JPP((JSAMPARRAY input_array, int source_row,
 385                                     JSAMPARRAY output_array, int dest_row,
 386                                     int num_rows, JDIMENSION num_cols));
 387 EXTERN(void) jcopy_block_row JPP((JBLOCKROW input_row, JBLOCKROW output_row,
 388                                   JDIMENSION num_blocks));
 389 EXTERN(void) jzero_far JPP((void FAR * target, size_t bytestozero));
 390 /* Constant tables in jutils.c */
 391 #if 0                           /* This table is not actually needed in v6a */
 392 extern const int jpeg_zigzag_order[]; /* natural coef order to zigzag order */
 393 #endif
 394 extern const int jpeg_natural_order[]; /* zigzag coef order to natural order */
 395
 396 /* Suppress undefined-structure complaints if necessary. */
 397
 398 #ifdef INCOMPLETE_TYPES_BROKEN
 399 #ifndef AM_MEMORY_MANAGER       /* only jmemmgr.c defines these */
 400 struct jvirt_sarray_control { long dummy; };
 401 struct jvirt_barray_control { long dummy; };
 402 #endif
 403 #endif /* INCOMPLETE_TYPES_BROKEN */