jpeglib.h revision ee451cb395940862dad63c85adfe8f2fd55e864c
1/* 2 * jpeglib.h 3 * 4 * Copyright (C) 1991-1998, 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 defines the application interface for the JPEG library. 9 * Most applications using the library need only include this file, 10 * and perhaps jerror.h if they want to know the exact error codes. 11 */ 12 13#ifndef JPEGLIB_H 14#define JPEGLIB_H 15 16#define FOXIT_PREFIX(origName) FPDFAPIJPEG_##origName 17 18#define jcopy_block_row FOXIT_PREFIX(jcopy_block_row) 19#define jcopy_sample_rows FOXIT_PREFIX(jcopy_sample_rows) 20#define jdiv_round_up FOXIT_PREFIX(jdiv_round_up) 21#define jinit_1pass_quantizer FOXIT_PREFIX(jinit_1pass_quantizer) 22#define jinit_2pass_quantizer FOXIT_PREFIX(jinit_2pass_quantizer) 23#define jinit_color_deconverter FOXIT_PREFIX(jinit_color_deconverter) 24#define jinit_d_coef_controller FOXIT_PREFIX(jinit_d_coef_controller) 25#define jinit_d_main_controller FOXIT_PREFIX(jinit_d_main_controller) 26#define jinit_d_post_controller FOXIT_PREFIX(jinit_d_post_controller) 27#define jinit_huff_decoder FOXIT_PREFIX(jinit_huff_decoder) 28#define jinit_input_controller FOXIT_PREFIX(jinit_input_controller) 29#define jinit_inverse_dct FOXIT_PREFIX(jinit_inverse_dct) 30#define jinit_marker_reader FOXIT_PREFIX(jinit_marker_reader) 31#define jinit_master_decompress FOXIT_PREFIX(jinit_master_decompress) 32#define jinit_memory_mgr FOXIT_PREFIX(jinit_memory_mgr) 33#define jinit_merged_upsampler FOXIT_PREFIX(jinit_merged_upsampler) 34#define jinit_phuff_decoder FOXIT_PREFIX(jinit_phuff_decoder) 35#define jinit_upsampler FOXIT_PREFIX(jinit_upsampler) 36#define jpeg_CreateDecompress FOXIT_PREFIX(jpeg_CreateDecompress) 37#define jpeg_abort FOXIT_PREFIX(jpeg_abort) 38#define jpeg_abort_decompress FOXIT_PREFIX(jpeg_abort_decompress) 39#define jpeg_alloc_huff_table FOXIT_PREFIX(jpeg_alloc_huff_table) 40#define jpeg_alloc_quant_table FOXIT_PREFIX(jpeg_alloc_quant_table) 41#define jpeg_calc_output_dimensions FOXIT_PREFIX(jpeg_calc_output_dimensions) 42#define jpeg_consume_input FOXIT_PREFIX(jpeg_consume_input) 43#define jpeg_destroy FOXIT_PREFIX(jpeg_destroy) 44#define jpeg_destroy_decompress FOXIT_PREFIX(jpeg_destroy_decompress) 45#define jpeg_fill_bit_buffer FOXIT_PREFIX(jpeg_fill_bit_buffer) 46#define jpeg_finish_decompress FOXIT_PREFIX(jpeg_finish_decompress) 47#define jpeg_finish_output FOXIT_PREFIX(jpeg_finish_output) 48#define jpeg_free_large FOXIT_PREFIX(jpeg_free_large) 49#define jpeg_free_small FOXIT_PREFIX(jpeg_free_small) 50#define jpeg_get_large FOXIT_PREFIX(jpeg_get_large) 51#define jpeg_get_small FOXIT_PREFIX(jpeg_get_small) 52#define jpeg_has_multiple_scans FOXIT_PREFIX(jpeg_has_multiple_scans) 53#define jpeg_huff_decode FOXIT_PREFIX(jpeg_huff_decode) 54#define jpeg_idct_1x1 FOXIT_PREFIX(jpeg_idct_1x1) 55#define jpeg_idct_2x2 FOXIT_PREFIX(jpeg_idct_2x2) 56#define jpeg_idct_4x4 FOXIT_PREFIX(jpeg_idct_4x4) 57#define jpeg_idct_float FOXIT_PREFIX(jpeg_idct_float) 58#define jpeg_idct_ifast FOXIT_PREFIX(jpeg_idct_ifast) 59#define jpeg_idct_islow FOXIT_PREFIX(jpeg_idct_islow) 60#define jpeg_input_complete FOXIT_PREFIX(jpeg_input_complete) 61#define jpeg_make_d_derived_tbl FOXIT_PREFIX(jpeg_make_d_derived_tbl) 62#define jpeg_mem_available FOXIT_PREFIX(jpeg_mem_available) 63#define jpeg_mem_init FOXIT_PREFIX(jpeg_mem_init) 64#define jpeg_mem_term FOXIT_PREFIX(jpeg_mem_term) 65#define jpeg_natural_order FOXIT_PREFIX(jpeg_natural_order) 66#define jpeg_new_colormap FOXIT_PREFIX(jpeg_new_colormap) 67#define jpeg_open_backing_store FOXIT_PREFIX(jpeg_open_backing_store) 68#define jpeg_read_coefficients FOXIT_PREFIX(jpeg_read_coefficients) 69#define jpeg_read_header FOXIT_PREFIX(jpeg_read_header) 70#define jpeg_read_raw_data FOXIT_PREFIX(jpeg_read_raw_data) 71#define jpeg_read_scanlines FOXIT_PREFIX(jpeg_read_scanlines) 72#define jpeg_resync_to_restart FOXIT_PREFIX(jpeg_resync_to_restart) 73#define jpeg_save_markers FOXIT_PREFIX(jpeg_save_markers) 74#define jpeg_set_marker_processor FOXIT_PREFIX(jpeg_set_marker_processor) 75#define jpeg_start_decompress FOXIT_PREFIX(jpeg_start_decompress) 76#define jpeg_start_output FOXIT_PREFIX(jpeg_start_output) 77#define jpeg_std_error FOXIT_PREFIX(jpeg_std_error) 78#define jpeg_std_message_table FOXIT_PREFIX(jpeg_std_message_table) 79#define jpeg_stdio_src FOXIT_PREFIX(jpeg_stdio_src) 80#define jround_up FOXIT_PREFIX(jround_up) 81#define jzero_far FOXIT_PREFIX(jzero_far) 82 83 /* 84 * First we include the configuration files that record how this 85 * installation of the JPEG library is set up. jconfig.h can be 86 * generated automatically for many systems. jmorecfg.h contains 87 * manual configuration options that most people need not worry about. 88 */ 89 90#ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */ 91#include "jconfig.h" /* widely used configuration options */ 92#endif 93#include "jmorecfg.h" /* seldom changed options */ 94 95 96/* Version ID for the JPEG library. 97 * Might be useful for tests like "#if JPEG_LIB_VERSION >= 60". 98 */ 99 100#define JPEG_LIB_VERSION 62 /* Version 6b */ 101 102 103/* Various constants determining the sizes of things. 104 * All of these are specified by the JPEG standard, so don't change them 105 * if you want to be compatible. 106 */ 107 108#define DCTSIZE 8 /* The basic DCT block is 8x8 samples */ 109#define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */ 110#define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */ 111#define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */ 112#define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */ 113#define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */ 114#define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */ 115/* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard; 116 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU. 117 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU 118 * to handle it. We even let you do this from the jconfig.h file. However, 119 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe 120 * sometimes emits noncompliant files doesn't mean you should too. 121 */ 122#define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */ 123#ifndef D_MAX_BLOCKS_IN_MCU 124#define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */ 125#endif 126 127 128/* Data structures for images (arrays of samples and of DCT coefficients). 129 * On 80x86 machines, the image arrays are too big for near pointers, 130 * but the pointer arrays can fit in near memory. 131 */ 132 133typedef JSAMPLE *JSAMPROW; /* ptr to one image row of pixel samples. */ 134typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */ 135typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */ 136 137typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */ 138typedef JBLOCK *JBLOCKROW; /* pointer to one row of coefficient blocks */ 139typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */ 140typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */ 141 142typedef JCOEF *JCOEFPTR; /* useful in a couple of places */ 143 144 145/* Types for JPEG compression parameters and working tables. */ 146 147 148/* DCT coefficient quantization tables. */ 149 150typedef struct { 151 /* This array gives the coefficient quantizers in natural array order 152 * (not the zigzag order in which they are stored in a JPEG DQT marker). 153 * CAUTION: IJG versions prior to v6a kept this array in zigzag order. 154 */ 155 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */ 156 /* This field is used only during compression. It's initialized FALSE when 157 * the table is created, and set TRUE when it's been output to the file. 158 * You could suppress output of a table by setting this to TRUE. 159 * (See jpeg_suppress_tables for an example.) 160 */ 161 boolean sent_table; /* TRUE when table has been output */ 162} JQUANT_TBL; 163 164 165/* Huffman coding tables. */ 166 167typedef struct { 168 /* These two fields directly represent the contents of a JPEG DHT marker */ 169 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */ 170 /* length k bits; bits[0] is unused */ 171 UINT8 huffval[256]; /* The symbols, in order of incr code length */ 172 /* This field is used only during compression. It's initialized FALSE when 173 * the table is created, and set TRUE when it's been output to the file. 174 * You could suppress output of a table by setting this to TRUE. 175 * (See jpeg_suppress_tables for an example.) 176 */ 177 boolean sent_table; /* TRUE when table has been output */ 178} JHUFF_TBL; 179 180 181/* Basic info about one component (color channel). */ 182 183typedef struct { 184 /* These values are fixed over the whole image. */ 185 /* For compression, they must be supplied by parameter setup; */ 186 /* for decompression, they are read from the SOF marker. */ 187 int component_id; /* identifier for this component (0..255) */ 188 int component_index; /* its index in SOF or cinfo->comp_info[] */ 189 int h_samp_factor; /* horizontal sampling factor (1..4) */ 190 int v_samp_factor; /* vertical sampling factor (1..4) */ 191 int quant_tbl_no; /* quantization table selector (0..3) */ 192 /* These values may vary between scans. */ 193 /* For compression, they must be supplied by parameter setup; */ 194 /* for decompression, they are read from the SOS marker. */ 195 /* The decompressor output side may not use these variables. */ 196 int dc_tbl_no; /* DC entropy table selector (0..3) */ 197 int ac_tbl_no; /* AC entropy table selector (0..3) */ 198 199 /* Remaining fields should be treated as private by applications. */ 200 201 /* These values are computed during compression or decompression startup: */ 202 /* Component's size in DCT blocks. 203 * Any dummy blocks added to complete an MCU are not counted; therefore 204 * these values do not depend on whether a scan is interleaved or not. 205 */ 206 JDIMENSION width_in_blocks; 207 JDIMENSION height_in_blocks; 208 /* Size of a DCT block in samples. Always DCTSIZE for compression. 209 * For decompression this is the size of the output from one DCT block, 210 * reflecting any scaling we choose to apply during the IDCT step. 211 * Values of 1,2,4,8 are likely to be supported. Note that different 212 * components may receive different IDCT scalings. 213 */ 214 int DCT_scaled_size; 215 /* The downsampled dimensions are the component's actual, unpadded number 216 * of samples at the main buffer (preprocessing/compression interface), thus 217 * downsampled_width = ceil(image_width * Hi/Hmax) 218 * and similarly for height. For decompression, IDCT scaling is included, so 219 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_scaled_size/DCTSIZE) 220 */ 221 JDIMENSION downsampled_width; /* actual width in samples */ 222 JDIMENSION downsampled_height; /* actual height in samples */ 223 /* This flag is used only for decompression. In cases where some of the 224 * components will be ignored (eg grayscale output from YCbCr image), 225 * we can skip most computations for the unused components. 226 */ 227 boolean component_needed; /* do we need the value of this component? */ 228 229 /* These values are computed before starting a scan of the component. */ 230 /* The decompressor output side may not use these variables. */ 231 int MCU_width; /* number of blocks per MCU, horizontally */ 232 int MCU_height; /* number of blocks per MCU, vertically */ 233 int MCU_blocks; /* MCU_width * MCU_height */ 234 int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_scaled_size */ 235 int last_col_width; /* # of non-dummy blocks across in last MCU */ 236 int last_row_height; /* # of non-dummy blocks down in last MCU */ 237 238 /* Saved quantization table for component; NULL if none yet saved. 239 * See jdinput.c comments about the need for this information. 240 * This field is currently used only for decompression. 241 */ 242 JQUANT_TBL * quant_table; 243 244 /* Private per-component storage for DCT or IDCT subsystem. */ 245 void * dct_table; 246} jpeg_component_info; 247 248 249/* The script for encoding a multiple-scan file is an array of these: */ 250 251typedef struct { 252 int comps_in_scan; /* number of components encoded in this scan */ 253 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */ 254 int Ss, Se; /* progressive JPEG spectral selection parms */ 255 int Ah, Al; /* progressive JPEG successive approx. parms */ 256} jpeg_scan_info; 257 258/* The decompressor can save APPn and COM markers in a list of these: */ 259 260typedef struct jpeg_marker_struct * jpeg_saved_marker_ptr; 261 262struct jpeg_marker_struct { 263 jpeg_saved_marker_ptr next; /* next in list, or NULL */ 264 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */ 265 unsigned int original_length; /* # bytes of data in the file */ 266 unsigned int data_length; /* # bytes of data saved at data[] */ 267 JOCTET * data; /* the data contained in the marker */ 268 /* the marker length word is not counted in data_length or original_length */ 269}; 270 271/* Known color spaces. */ 272 273typedef enum { 274 JCS_UNKNOWN, /* error/unspecified */ 275 JCS_GRAYSCALE, /* monochrome */ 276 JCS_RGB, /* red/green/blue */ 277 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */ 278 JCS_CMYK, /* C/M/Y/K */ 279 JCS_YCCK /* Y/Cb/Cr/K */ 280} J_COLOR_SPACE; 281 282/* DCT/IDCT algorithm options. */ 283 284typedef enum { 285 JDCT_ISLOW, /* slow but accurate integer algorithm */ 286 JDCT_IFAST, /* faster, less accurate integer method */ 287 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */ 288} J_DCT_METHOD; 289 290#ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */ 291#define JDCT_DEFAULT JDCT_ISLOW 292#endif 293#ifndef JDCT_FASTEST /* may be overridden in jconfig.h */ 294#define JDCT_FASTEST JDCT_IFAST 295#endif 296 297/* Dithering options for decompression. */ 298 299typedef enum { 300 JDITHER_NONE, /* no dithering */ 301 JDITHER_ORDERED, /* simple ordered dither */ 302 JDITHER_FS /* Floyd-Steinberg error diffusion dither */ 303} J_DITHER_MODE; 304 305 306/* Common fields between JPEG compression and decompression master structs. */ 307 308#define jpeg_common_fields \ 309 struct jpeg_error_mgr * err; /* Error handler module */\ 310 struct jpeg_memory_mgr * mem; /* Memory manager module */\ 311 struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\ 312 void * client_data; /* Available for use by application */\ 313 boolean is_decompressor; /* So common code can tell which is which */\ 314 int global_state /* For checking call sequence validity */ 315 316/* Routines that are to be used by both halves of the library are declared 317 * to receive a pointer to this structure. There are no actual instances of 318 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct. 319 */ 320struct jpeg_common_struct { 321 jpeg_common_fields; /* Fields common to both master struct types */ 322 /* Additional fields follow in an actual jpeg_compress_struct or 323 * jpeg_decompress_struct. All three structs must agree on these 324 * initial fields! (This would be a lot cleaner in C++.) 325 */ 326}; 327 328typedef struct jpeg_common_struct * j_common_ptr; 329typedef struct jpeg_compress_struct * j_compress_ptr; 330typedef struct jpeg_decompress_struct * j_decompress_ptr; 331 332 333/* Master record for a compression instance */ 334 335struct jpeg_compress_struct { 336 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */ 337 338 /* Destination for compressed data */ 339 struct jpeg_destination_mgr * dest; 340 341 /* Description of source image --- these fields must be filled in by 342 * outer application before starting compression. in_color_space must 343 * be correct before you can even call jpeg_set_defaults(). 344 */ 345 346 JDIMENSION image_width; /* input image width */ 347 JDIMENSION image_height; /* input image height */ 348 int input_components; /* # of color components in input image */ 349 J_COLOR_SPACE in_color_space; /* colorspace of input image */ 350 351 double input_gamma; /* image gamma of input image */ 352 353 /* Compression parameters --- these fields must be set before calling 354 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to 355 * initialize everything to reasonable defaults, then changing anything 356 * the application specifically wants to change. That way you won't get 357 * burnt when new parameters are added. Also note that there are several 358 * helper routines to simplify changing parameters. 359 */ 360 361 int data_precision; /* bits of precision in image data */ 362 363 int num_components; /* # of color components in JPEG image */ 364 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 365 366 jpeg_component_info * comp_info; 367 /* comp_info[i] describes component that appears i'th in SOF */ 368 369 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 370 /* ptrs to coefficient quantization tables, or NULL if not defined */ 371 372 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 373 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 374 /* ptrs to Huffman coding tables, or NULL if not defined */ 375 376 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 377 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 378 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 379 380 int num_scans; /* # of entries in scan_info array */ 381 const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */ 382 /* The default value of scan_info is NULL, which causes a single-scan 383 * sequential JPEG file to be emitted. To create a multi-scan file, 384 * set num_scans and scan_info to point to an array of scan definitions. 385 */ 386 387 boolean raw_data_in; /* TRUE=caller supplies downsampled data */ 388 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 389 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */ 390 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 391 int smoothing_factor; /* 1..100, or 0 for no input smoothing */ 392 J_DCT_METHOD dct_method; /* DCT algorithm selector */ 393 394 /* The restart interval can be specified in absolute MCUs by setting 395 * restart_interval, or in MCU rows by setting restart_in_rows 396 * (in which case the correct restart_interval will be figured 397 * for each scan). 398 */ 399 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */ 400 int restart_in_rows; /* if > 0, MCU rows per restart interval */ 401 402 /* Parameters controlling emission of special markers. */ 403 404 boolean write_JFIF_header; /* should a JFIF marker be written? */ 405 UINT8 JFIF_major_version; /* What to write for the JFIF version number */ 406 UINT8 JFIF_minor_version; 407 /* These three values are not used by the JPEG code, merely copied */ 408 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */ 409 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */ 410 /* ratio is defined by X_density/Y_density even when density_unit=0. */ 411 UINT8 density_unit; /* JFIF code for pixel size units */ 412 UINT16 X_density; /* Horizontal pixel density */ 413 UINT16 Y_density; /* Vertical pixel density */ 414 boolean write_Adobe_marker; /* should an Adobe marker be written? */ 415 416 /* State variable: index of next scanline to be written to 417 * jpeg_write_scanlines(). Application may use this to control its 418 * processing loop, e.g., "while (next_scanline < image_height)". 419 */ 420 421 JDIMENSION next_scanline; /* 0 .. image_height-1 */ 422 423 /* Remaining fields are known throughout compressor, but generally 424 * should not be touched by a surrounding application. 425 */ 426 427 /* 428 * These fields are computed during compression startup 429 */ 430 boolean progressive_mode; /* TRUE if scan script uses progressive mode */ 431 int max_h_samp_factor; /* largest h_samp_factor */ 432 int max_v_samp_factor; /* largest v_samp_factor */ 433 434 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */ 435 /* The coefficient controller receives data in units of MCU rows as defined 436 * for fully interleaved scans (whether the JPEG file is interleaved or not). 437 * There are v_samp_factor * DCTSIZE sample rows of each component in an 438 * "iMCU" (interleaved MCU) row. 439 */ 440 441 /* 442 * These fields are valid during any one scan. 443 * They describe the components and MCUs actually appearing in the scan. 444 */ 445 int comps_in_scan; /* # of JPEG components in this scan */ 446 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 447 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 448 449 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 450 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 451 452 int blocks_in_MCU; /* # of DCT blocks per MCU */ 453 int MCU_membership[C_MAX_BLOCKS_IN_MCU]; 454 /* MCU_membership[i] is index in cur_comp_info of component owning */ 455 /* i'th block in an MCU */ 456 457 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 458 459 /* 460 * Links to compression subobjects (methods and private variables of modules) 461 */ 462 struct jpeg_comp_master * master; 463 struct jpeg_c_main_controller * main; 464 struct jpeg_c_prep_controller * prep; 465 struct jpeg_c_coef_controller * coef; 466 struct jpeg_marker_writer * marker; 467 struct jpeg_color_converter * cconvert; 468 struct jpeg_downsampler * downsample; 469 struct jpeg_forward_dct * fdct; 470 struct jpeg_entropy_encoder * entropy; 471 jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */ 472 int script_space_size; 473}; 474 475 476/* Master record for a decompression instance */ 477 478struct jpeg_decompress_struct { 479 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */ 480 481 /* Source of compressed data */ 482 struct jpeg_source_mgr * src; 483 484 /* Basic description of image --- filled in by jpeg_read_header(). */ 485 /* Application may inspect these values to decide how to process image. */ 486 487 JDIMENSION image_width; /* nominal image width (from SOF marker) */ 488 JDIMENSION image_height; /* nominal image height */ 489 int num_components; /* # of color components in JPEG image */ 490 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 491 492 /* Decompression processing parameters --- these fields must be set before 493 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes 494 * them to default values. 495 */ 496 497 J_COLOR_SPACE out_color_space; /* colorspace for output */ 498 499 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 500 501 double output_gamma; /* image gamma wanted in output */ 502 503 boolean buffered_image; /* TRUE=multiple output passes */ 504 boolean raw_data_out; /* TRUE=downsampled data wanted */ 505 506 J_DCT_METHOD dct_method; /* IDCT algorithm selector */ 507 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */ 508 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */ 509 510 boolean quantize_colors; /* TRUE=colormapped output wanted */ 511 /* the following are ignored if not quantize_colors: */ 512 J_DITHER_MODE dither_mode; /* type of color dithering to use */ 513 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */ 514 int desired_number_of_colors; /* max # colors to use in created colormap */ 515 /* these are significant only in buffered-image mode: */ 516 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */ 517 boolean enable_external_quant;/* enable future use of external colormap */ 518 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */ 519 520 /* Description of actual output image that will be returned to application. 521 * These fields are computed by jpeg_start_decompress(). 522 * You can also use jpeg_calc_output_dimensions() to determine these values 523 * in advance of calling jpeg_start_decompress(). 524 */ 525 526 JDIMENSION output_width; /* scaled image width */ 527 JDIMENSION output_height; /* scaled image height */ 528 int out_color_components; /* # of color components in out_color_space */ 529 int output_components; /* # of color components returned */ 530 /* output_components is 1 (a colormap index) when quantizing colors; 531 * otherwise it equals out_color_components. 532 */ 533 int rec_outbuf_height; /* min recommended height of scanline buffer */ 534 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows 535 * high, space and time will be wasted due to unnecessary data copying. 536 * Usually rec_outbuf_height will be 1 or 2, at most 4. 537 */ 538 539 /* When quantizing colors, the output colormap is described by these fields. 540 * The application can supply a colormap by setting colormap non-NULL before 541 * calling jpeg_start_decompress; otherwise a colormap is created during 542 * jpeg_start_decompress or jpeg_start_output. 543 * The map has out_color_components rows and actual_number_of_colors columns. 544 */ 545 int actual_number_of_colors; /* number of entries in use */ 546 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */ 547 548 /* State variables: these variables indicate the progress of decompression. 549 * The application may examine these but must not modify them. 550 */ 551 552 /* Row index of next scanline to be read from jpeg_read_scanlines(). 553 * Application may use this to control its processing loop, e.g., 554 * "while (output_scanline < output_height)". 555 */ 556 JDIMENSION output_scanline; /* 0 .. output_height-1 */ 557 558 /* Current input scan number and number of iMCU rows completed in scan. 559 * These indicate the progress of the decompressor input side. 560 */ 561 int input_scan_number; /* Number of SOS markers seen so far */ 562 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */ 563 564 /* The "output scan number" is the notional scan being displayed by the 565 * output side. The decompressor will not allow output scan/row number 566 * to get ahead of input scan/row, but it can fall arbitrarily far behind. 567 */ 568 int output_scan_number; /* Nominal scan number being displayed */ 569 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */ 570 571 /* Current progression status. coef_bits[c][i] indicates the precision 572 * with which component c's DCT coefficient i (in zigzag order) is known. 573 * It is -1 when no data has yet been received, otherwise it is the point 574 * transform (shift) value for the most recent scan of the coefficient 575 * (thus, 0 at completion of the progression). 576 * This pointer is NULL when reading a non-progressive file. 577 */ 578 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */ 579 580 /* Internal JPEG parameters --- the application usually need not look at 581 * these fields. Note that the decompressor output side may not use 582 * any parameters that can change between scans. 583 */ 584 585 /* Quantization and Huffman tables are carried forward across input 586 * datastreams when processing abbreviated JPEG datastreams. 587 */ 588 589 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 590 /* ptrs to coefficient quantization tables, or NULL if not defined */ 591 592 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 593 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 594 /* ptrs to Huffman coding tables, or NULL if not defined */ 595 596 /* These parameters are never carried across datastreams, since they 597 * are given in SOF/SOS markers or defined to be reset by SOI. 598 */ 599 600 int data_precision; /* bits of precision in image data */ 601 602 jpeg_component_info * comp_info; 603 /* comp_info[i] describes component that appears i'th in SOF */ 604 605 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */ 606 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 607 608 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 609 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 610 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 611 612 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */ 613 614 /* These fields record data obtained from optional markers recognized by 615 * the JPEG library. 616 */ 617 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */ 618 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */ 619 UINT8 JFIF_major_version; /* JFIF version number */ 620 UINT8 JFIF_minor_version; 621 UINT8 density_unit; /* JFIF code for pixel size units */ 622 UINT16 X_density; /* Horizontal pixel density */ 623 UINT16 Y_density; /* Vertical pixel density */ 624 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */ 625 UINT8 Adobe_transform; /* Color transform code from Adobe marker */ 626 627 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 628 629 /* Aside from the specific data retained from APPn markers known to the 630 * library, the uninterpreted contents of any or all APPn and COM markers 631 * can be saved in a list for examination by the application. 632 */ 633 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */ 634 635 /* Remaining fields are known throughout decompressor, but generally 636 * should not be touched by a surrounding application. 637 */ 638 639 /* 640 * These fields are computed during decompression startup 641 */ 642 int max_h_samp_factor; /* largest h_samp_factor */ 643 int max_v_samp_factor; /* largest v_samp_factor */ 644 645 int min_DCT_scaled_size; /* smallest DCT_scaled_size of any component */ 646 647 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */ 648 /* The coefficient controller's input and output progress is measured in 649 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows 650 * in fully interleaved JPEG scans, but are used whether the scan is 651 * interleaved or not. We define an iMCU row as v_samp_factor DCT block 652 * rows of each component. Therefore, the IDCT output contains 653 * v_samp_factor*DCT_scaled_size sample rows of a component per iMCU row. 654 */ 655 656 JSAMPLE * sample_range_limit; /* table for fast range-limiting */ 657 658 /* 659 * These fields are valid during any one scan. 660 * They describe the components and MCUs actually appearing in the scan. 661 * Note that the decompressor output side must not use these fields. 662 */ 663 int comps_in_scan; /* # of JPEG components in this scan */ 664 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 665 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 666 667 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 668 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 669 670 int blocks_in_MCU; /* # of DCT blocks per MCU */ 671 int MCU_membership[D_MAX_BLOCKS_IN_MCU]; 672 /* MCU_membership[i] is index in cur_comp_info of component owning */ 673 /* i'th block in an MCU */ 674 675 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 676 677 /* This field is shared between entropy decoder and marker parser. 678 * It is either zero or the code of a JPEG marker that has been 679 * read from the data source, but has not yet been processed. 680 */ 681 int unread_marker; 682 683 /* 684 * Links to decompression subobjects (methods, private variables of modules) 685 */ 686 struct jpeg_decomp_master * master; 687 struct jpeg_d_main_controller * main; 688 struct jpeg_d_coef_controller * coef; 689 struct jpeg_d_post_controller * post; 690 struct jpeg_input_controller * inputctl; 691 struct jpeg_marker_reader * marker; 692 struct jpeg_entropy_decoder * entropy; 693 struct jpeg_inverse_dct * idct; 694 struct jpeg_upsampler * upsample; 695 struct jpeg_color_deconverter * cconvert; 696 struct jpeg_color_quantizer * cquantize; 697}; 698 699 700/* "Object" declarations for JPEG modules that may be supplied or called 701 * directly by the surrounding application. 702 * As with all objects in the JPEG library, these structs only define the 703 * publicly visible methods and state variables of a module. Additional 704 * private fields may exist after the public ones. 705 */ 706 707 708/* Error handler object */ 709 710struct jpeg_error_mgr { 711 /* Error exit handler: does not return to caller */ 712 JMETHOD(void, error_exit, (j_common_ptr cinfo)); 713 /* Conditionally emit a trace or warning message */ 714 JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level)); 715 /* Routine that actually outputs a trace or error message */ 716 JMETHOD(void, output_message, (j_common_ptr cinfo)); 717 /* Format a message string for the most recent JPEG error or message */ 718 JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer)); 719#define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */ 720 /* Reset error state variables at start of a new image */ 721 JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo)); 722 723 /* The message ID code and any parameters are saved here. 724 * A message can have one string parameter or up to 8 int parameters. 725 */ 726 int msg_code; 727#define JMSG_STR_PARM_MAX 80 728 union { 729 int i[8]; 730 char s[JMSG_STR_PARM_MAX]; 731 } msg_parm; 732 733 /* Standard state variables for error facility */ 734 735 int trace_level; /* max msg_level that will be displayed */ 736 737 /* For recoverable corrupt-data errors, we emit a warning message, 738 * but keep going unless emit_message chooses to abort. emit_message 739 * should count warnings in num_warnings. The surrounding application 740 * can check for bad data by seeing if num_warnings is nonzero at the 741 * end of processing. 742 */ 743 long num_warnings; /* number of corrupt-data warnings */ 744 745 /* These fields point to the table(s) of error message strings. 746 * An application can change the table pointer to switch to a different 747 * message list (typically, to change the language in which errors are 748 * reported). Some applications may wish to add additional error codes 749 * that will be handled by the JPEG library error mechanism; the second 750 * table pointer is used for this purpose. 751 * 752 * First table includes all errors generated by JPEG library itself. 753 * Error code 0 is reserved for a "no such error string" message. 754 */ 755 const char * const * jpeg_message_table; /* Library errors */ 756 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */ 757 /* Second table can be added by application (see cjpeg/djpeg for example). 758 * It contains strings numbered first_addon_message..last_addon_message. 759 */ 760 const char * const * addon_message_table; /* Non-library errors */ 761 int first_addon_message; /* code for first string in addon table */ 762 int last_addon_message; /* code for last string in addon table */ 763}; 764 765 766/* Progress monitor object */ 767 768struct jpeg_progress_mgr { 769 JMETHOD(void, progress_monitor, (j_common_ptr cinfo)); 770 771 long pass_counter; /* work units completed in this pass */ 772 long pass_limit; /* total number of work units in this pass */ 773 int completed_passes; /* passes completed so far */ 774 int total_passes; /* total number of passes expected */ 775}; 776 777 778/* Data destination object for compression */ 779 780struct jpeg_destination_mgr { 781 JOCTET * next_output_byte; /* => next byte to write in buffer */ 782 size_t free_in_buffer; /* # of byte spaces remaining in buffer */ 783 784 JMETHOD(void, init_destination, (j_compress_ptr cinfo)); 785 JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo)); 786 JMETHOD(void, term_destination, (j_compress_ptr cinfo)); 787}; 788 789 790/* Data source object for decompression */ 791 792struct jpeg_source_mgr { 793 const JOCTET * next_input_byte; /* => next byte to read from buffer */ 794 size_t bytes_in_buffer; /* # of bytes remaining in buffer */ 795 796 JMETHOD(void, init_source, (j_decompress_ptr cinfo)); 797 JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo)); 798 JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes)); 799 JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired)); 800 JMETHOD(void, term_source, (j_decompress_ptr cinfo)); 801}; 802 803 804/* Memory manager object. 805 * Allocates "small" objects (a few K total), "large" objects (tens of K), 806 * and "really big" objects (virtual arrays with backing store if needed). 807 * The memory manager does not allow individual objects to be freed; rather, 808 * each created object is assigned to a pool, and whole pools can be freed 809 * at once. This is faster and more convenient than remembering exactly what 810 * to free, especially where malloc()/free() are not too speedy. 811 * NB: alloc routines never return NULL. They exit to error_exit if not 812 * successful. 813 */ 814 815#define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */ 816#define JPOOL_IMAGE 1 /* lasts until done with image/datastream */ 817#define JPOOL_NUMPOOLS 2 818 819typedef struct jvirt_sarray_control * jvirt_sarray_ptr; 820typedef struct jvirt_barray_control * jvirt_barray_ptr; 821 822 823struct jpeg_memory_mgr { 824 /* Method pointers */ 825 JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id, 826 size_t sizeofobject)); 827 JMETHOD(void *, alloc_large, (j_common_ptr cinfo, int pool_id, 828 size_t sizeofobject)); 829 JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id, 830 JDIMENSION samplesperrow, 831 JDIMENSION numrows)); 832 JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id, 833 JDIMENSION blocksperrow, 834 JDIMENSION numrows)); 835 JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo, 836 int pool_id, 837 boolean pre_zero, 838 JDIMENSION samplesperrow, 839 JDIMENSION numrows, 840 JDIMENSION maxaccess)); 841 JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo, 842 int pool_id, 843 boolean pre_zero, 844 JDIMENSION blocksperrow, 845 JDIMENSION numrows, 846 JDIMENSION maxaccess)); 847 JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo)); 848 JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo, 849 jvirt_sarray_ptr ptr, 850 JDIMENSION start_row, 851 JDIMENSION num_rows, 852 boolean writable)); 853 JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo, 854 jvirt_barray_ptr ptr, 855 JDIMENSION start_row, 856 JDIMENSION num_rows, 857 boolean writable)); 858 JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id)); 859 JMETHOD(void, self_destruct, (j_common_ptr cinfo)); 860 861 /* Limit on memory allocation for this JPEG object. (Note that this is 862 * merely advisory, not a guaranteed maximum; it only affects the space 863 * used for virtual-array buffers.) May be changed by outer application 864 * after creating the JPEG object. 865 */ 866 long max_memory_to_use; 867 868 /* Maximum allocation request accepted by alloc_large. */ 869 long max_alloc_chunk; 870}; 871 872 873/* Routine signature for application-supplied marker processing methods. 874 * Need not pass marker code since it is stored in cinfo->unread_marker. 875 */ 876typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo)); 877 878 879/* Declarations for routines called by application. 880 * The JPP macro hides prototype parameters from compilers that can't cope. 881 * Note JPP requires double parentheses. 882 */ 883 884#ifdef HAVE_PROTOTYPES 885#define JPP(arglist) arglist 886#else 887#define JPP(arglist) () 888#endif 889 890 891/* Short forms of external names for systems with brain-damaged linkers. 892 * We shorten external names to be unique in the first six letters, which 893 * is good enough for all known systems. 894 * (If your compiler itself needs names to be unique in less than 15 895 * characters, you are out of luck. Get a better compiler.) 896 */ 897 898#ifdef NEED_SHORT_EXTERNAL_NAMES 899#define jpeg_std_error jStdError 900#define jpeg_CreateCompress jCreaCompress 901#define jpeg_CreateDecompress jCreaDecompress 902#define jpeg_destroy_compress jDestCompress 903#define jpeg_destroy_decompress jDestDecompress 904#define jpeg_stdio_dest jStdDest 905#define jpeg_stdio_src jStdSrc 906#define jpeg_set_defaults jSetDefaults 907#define jpeg_set_colorspace jSetColorspace 908#define jpeg_default_colorspace jDefColorspace 909#define jpeg_set_quality jSetQuality 910#define jpeg_set_linear_quality jSetLQuality 911#define jpeg_add_quant_table jAddQuantTable 912#define jpeg_quality_scaling jQualityScaling 913#define jpeg_simple_progression jSimProgress 914#define jpeg_suppress_tables jSuppressTables 915#define jpeg_alloc_quant_table jAlcQTable 916#define jpeg_alloc_huff_table jAlcHTable 917#define jpeg_start_compress jStrtCompress 918#define jpeg_write_scanlines jWrtScanlines 919#define jpeg_finish_compress jFinCompress 920#define jpeg_write_raw_data jWrtRawData 921#define jpeg_write_marker jWrtMarker 922#define jpeg_write_m_header jWrtMHeader 923#define jpeg_write_m_byte jWrtMByte 924#define jpeg_write_tables jWrtTables 925#define jpeg_read_header jReadHeader 926#define jpeg_start_decompress jStrtDecompress 927#define jpeg_read_scanlines jReadScanlines 928#define jpeg_finish_decompress jFinDecompress 929#define jpeg_read_raw_data jReadRawData 930#define jpeg_has_multiple_scans jHasMultScn 931#define jpeg_start_output jStrtOutput 932#define jpeg_finish_output jFinOutput 933#define jpeg_input_complete jInComplete 934#define jpeg_new_colormap jNewCMap 935#define jpeg_consume_input jConsumeInput 936#define jpeg_calc_output_dimensions jCalcDimensions 937#define jpeg_save_markers jSaveMarkers 938#define jpeg_set_marker_processor jSetMarker 939#define jpeg_read_coefficients jReadCoefs 940#define jpeg_write_coefficients jWrtCoefs 941#define jpeg_copy_critical_parameters jCopyCrit 942#define jpeg_abort_compress jAbrtCompress 943#define jpeg_abort_decompress jAbrtDecompress 944#define jpeg_abort jAbort 945#define jpeg_destroy jDestroy 946#define jpeg_resync_to_restart jResyncRestart 947#endif /* NEED_SHORT_EXTERNAL_NAMES */ 948 949 950/* Default error-management setup */ 951EXTERN(struct jpeg_error_mgr *) jpeg_std_error 952 JPP((struct jpeg_error_mgr * err)); 953 954/* Initialization of JPEG compression objects. 955 * jpeg_create_compress() and jpeg_create_decompress() are the exported 956 * names that applications should call. These expand to calls on 957 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information 958 * passed for version mismatch checking. 959 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx. 960 */ 961#define jpeg_create_compress(cinfo) \ 962 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \ 963 (size_t) sizeof(struct jpeg_compress_struct)) 964#define jpeg_create_decompress(cinfo) \ 965 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \ 966 (size_t) sizeof(struct jpeg_decompress_struct)) 967EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo, 968 int version, size_t structsize)); 969EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo, 970 int version, size_t structsize)); 971/* Destruction of JPEG compression objects */ 972EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo)); 973EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo)); 974 975#if 0 976/* Standard data source and destination managers: stdio streams. */ 977/* Caller is responsible for opening the file before and closing after. */ 978EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FXSYS_FILE * outfile)); 979EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FXSYS_FILE * infile)); 980#endif 981 982/* Default parameter setup for compression */ 983EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo)); 984/* Compression parameter setup aids */ 985EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo, 986 J_COLOR_SPACE colorspace)); 987EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo)); 988EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality, 989 boolean force_baseline)); 990EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo, 991 int scale_factor, 992 boolean force_baseline)); 993EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl, 994 const unsigned int *basic_table, 995 int scale_factor, 996 boolean force_baseline)); 997EXTERN(int) jpeg_quality_scaling JPP((int quality)); 998EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo)); 999EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo, 1000 boolean suppress)); 1001EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo)); 1002EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo)); 1003 1004/* Main entry points for compression */ 1005EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo, 1006 boolean write_all_tables)); 1007EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo, 1008 JSAMPARRAY scanlines, 1009 JDIMENSION num_lines)); 1010EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo)); 1011 1012/* Replaces jpeg_write_scanlines when writing raw downsampled data. */ 1013EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo, 1014 JSAMPIMAGE data, 1015 JDIMENSION num_lines)); 1016 1017/* Write a special marker. See libjpeg.doc concerning safe usage. */ 1018EXTERN(void) jpeg_write_marker 1019 JPP((j_compress_ptr cinfo, int marker, 1020 const JOCTET * dataptr, unsigned int datalen)); 1021/* Same, but piecemeal. */ 1022EXTERN(void) jpeg_write_m_header 1023 JPP((j_compress_ptr cinfo, int marker, unsigned int datalen)); 1024EXTERN(void) jpeg_write_m_byte 1025 JPP((j_compress_ptr cinfo, int val)); 1026 1027/* Alternate compression function: just write an abbreviated table file */ 1028EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo)); 1029 1030/* Decompression startup: read start of JPEG datastream to see what's there */ 1031EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo, 1032 boolean require_image)); 1033/* Return value is one of: */ 1034#define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */ 1035#define JPEG_HEADER_OK 1 /* Found valid image datastream */ 1036#define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */ 1037/* If you pass require_image = TRUE (normal case), you need not check for 1038 * a TABLES_ONLY return code; an abbreviated file will cause an error exit. 1039 * JPEG_SUSPENDED is only possible if you use a data source module that can 1040 * give a suspension return (the stdio source module doesn't). 1041 */ 1042 1043/* Main entry points for decompression */ 1044EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo)); 1045EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo, 1046 JSAMPARRAY scanlines, 1047 JDIMENSION max_lines)); 1048EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo)); 1049 1050/* Replaces jpeg_read_scanlines when reading raw downsampled data. */ 1051EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo, 1052 JSAMPIMAGE data, 1053 JDIMENSION max_lines)); 1054 1055/* Additional entry points for buffered-image mode. */ 1056EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo)); 1057EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo, 1058 int scan_number)); 1059EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo)); 1060EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo)); 1061EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo)); 1062EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo)); 1063/* Return value is one of: */ 1064/* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */ 1065#define JPEG_REACHED_SOS 1 /* Reached start of new scan */ 1066#define JPEG_REACHED_EOI 2 /* Reached end of image */ 1067#define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */ 1068#define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */ 1069 1070/* Precalculate output dimensions for current decompression parameters. */ 1071EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo)); 1072 1073/* Control saving of COM and APPn markers into marker_list. */ 1074EXTERN(void) jpeg_save_markers 1075 JPP((j_decompress_ptr cinfo, int marker_code, 1076 unsigned int length_limit)); 1077 1078/* Install a special processing method for COM or APPn markers. */ 1079EXTERN(void) jpeg_set_marker_processor 1080 JPP((j_decompress_ptr cinfo, int marker_code, 1081 jpeg_marker_parser_method routine)); 1082 1083/* Read or write raw DCT coefficients --- useful for lossless transcoding. */ 1084EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo)); 1085EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo, 1086 jvirt_barray_ptr * coef_arrays)); 1087EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo, 1088 j_compress_ptr dstinfo)); 1089 1090/* If you choose to abort compression or decompression before completing 1091 * jpeg_finish_(de)compress, then you need to clean up to release memory, 1092 * temporary files, etc. You can just call jpeg_destroy_(de)compress 1093 * if you're done with the JPEG object, but if you want to clean it up and 1094 * reuse it, call this: 1095 */ 1096EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo)); 1097EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo)); 1098 1099/* Generic versions of jpeg_abort and jpeg_destroy that work on either 1100 * flavor of JPEG object. These may be more convenient in some places. 1101 */ 1102EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo)); 1103EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo)); 1104 1105/* Default restart-marker-resync procedure for use by data source modules */ 1106EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo, 1107 int desired)); 1108 1109 1110/* These marker codes are exported since applications and data source modules 1111 * are likely to want to use them. 1112 */ 1113 1114#define JPEG_RST0 0xD0 /* RST0 marker code */ 1115#define JPEG_EOI 0xD9 /* EOI marker code */ 1116#define JPEG_APP0 0xE0 /* APP0 marker code */ 1117#define JPEG_COM 0xFE /* COM marker code */ 1118 1119 1120/* If we have a brain-damaged compiler that emits warnings (or worse, errors) 1121 * for structure definitions that are never filled in, keep it quiet by 1122 * supplying dummy definitions for the various substructures. 1123 */ 1124 1125#ifdef INCOMPLETE_TYPES_BROKEN 1126#ifndef JPEG_INTERNALS /* will be defined in jpegint.h */ 1127struct jvirt_sarray_control { long dummy; }; 1128struct jvirt_barray_control { long dummy; }; 1129struct jpeg_comp_master { long dummy; }; 1130struct jpeg_c_main_controller { long dummy; }; 1131struct jpeg_c_prep_controller { long dummy; }; 1132struct jpeg_c_coef_controller { long dummy; }; 1133struct jpeg_marker_writer { long dummy; }; 1134struct jpeg_color_converter { long dummy; }; 1135struct jpeg_downsampler { long dummy; }; 1136struct jpeg_forward_dct { long dummy; }; 1137struct jpeg_entropy_encoder { long dummy; }; 1138struct jpeg_decomp_master { long dummy; }; 1139struct jpeg_d_main_controller { long dummy; }; 1140struct jpeg_d_coef_controller { long dummy; }; 1141struct jpeg_d_post_controller { long dummy; }; 1142struct jpeg_input_controller { long dummy; }; 1143struct jpeg_marker_reader { long dummy; }; 1144struct jpeg_entropy_decoder { long dummy; }; 1145struct jpeg_inverse_dct { long dummy; }; 1146struct jpeg_upsampler { long dummy; }; 1147struct jpeg_color_deconverter { long dummy; }; 1148struct jpeg_color_quantizer { long dummy; }; 1149#endif /* JPEG_INTERNALS */ 1150#endif /* INCOMPLETE_TYPES_BROKEN */ 1151 1152 1153/* 1154 * The JPEG library modules define JPEG_INTERNALS before including this file. 1155 * The internal structure declarations are read only when that is true. 1156 * Applications using the library should not include jpegint.h, but may wish 1157 * to include jerror.h. 1158 */ 1159 1160#ifdef JPEG_INTERNALS 1161#include "jpegint.h" /* fetch private declarations */ 1162#include "jerror.h" /* fetch error codes too */ 1163#endif 1164 1165#endif /* JPEGLIB_H */ 1166