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 /* 17 * First we include the configuration files that record how this 18 * installation of the JPEG library is set up. jconfig.h can be 19 * generated automatically for many systems. jmorecfg.h contains 20 * manual configuration options that most people need not worry about. 21 */ 22 23 #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */ 24 #include "jconfig.h" /* widely used configuration options */ 25 #endif 26 #include "jmorecfg.h" /* seldom changed options */ 27 28 29 /* Version ID for the JPEG library. 30 * Might be useful for tests like "#if JPEG_LIB_VERSION >= 60". 31 */ 32 33 #define JPEG_LIB_VERSION 62 /* Version 6b */ 34 35 36 /* Various constants determining the sizes of things. 37 * All of these are specified by the JPEG standard, so don't change them 38 * if you want to be compatible. 39 */ 40 41 #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */ 42 #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */ 43 #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */ 44 #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */ 45 #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */ 46 #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */ 47 #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */ 48 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard; 49 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU. 50 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU 51 * to handle it. We even let you do this from the jconfig.h file. However, 52 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe 53 * sometimes emits noncompliant files doesn't mean you should too. 54 */ 55 #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */ 56 #ifndef D_MAX_BLOCKS_IN_MCU 57 #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */ 58 #endif 59 60 61 /* Data structures for images (arrays of samples and of DCT coefficients). 62 * On 80x86 machines, the image arrays are too big for near pointers, 63 * but the pointer arrays can fit in near memory. 64 */ 65 66 typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */ 67 typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */ 68 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */ 69 70 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */ 71 typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */ 72 typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */ 73 typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */ 74 75 typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */ 76 77 78 /* Types for JPEG compression parameters and working tables. */ 79 80 81 /* DCT coefficient quantization tables. */ 82 83 typedef struct { 84 /* This array gives the coefficient quantizers in natural array order 85 * (not the zigzag order in which they are stored in a JPEG DQT marker). 86 * CAUTION: IJG versions prior to v6a kept this array in zigzag order. 87 */ 88 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */ 89 /* This field is used only during compression. It's initialized FALSE when 90 * the table is created, and set TRUE when it's been output to the file. 91 * You could suppress output of a table by setting this to TRUE. 92 * (See jpeg_suppress_tables for an example.) 93 */ 94 boolean sent_table; /* TRUE when table has been output */ 95 } JQUANT_TBL; 96 97 98 /* Huffman coding tables. */ 99 100 typedef struct { 101 /* These two fields directly represent the contents of a JPEG DHT marker */ 102 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */ 103 /* length k bits; bits[0] is unused */ 104 UINT8 huffval[256]; /* The symbols, in order of incr code length */ 105 /* This field is used only during compression. It's initialized FALSE when 106 * the table is created, and set TRUE when it's been output to the file. 107 * You could suppress output of a table by setting this to TRUE. 108 * (See jpeg_suppress_tables for an example.) 109 */ 110 boolean sent_table; /* TRUE when table has been output */ 111 } JHUFF_TBL; 112 113 114 /* Basic info about one component (color channel). */ 115 116 typedef struct { 117 /* These values are fixed over the whole image. */ 118 /* For compression, they must be supplied by parameter setup; */ 119 /* for decompression, they are read from the SOF marker. */ 120 int component_id; /* identifier for this component (0..255) */ 121 int component_index; /* its index in SOF or cinfo->comp_info[] */ 122 int h_samp_factor; /* horizontal sampling factor (1..4) */ 123 int v_samp_factor; /* vertical sampling factor (1..4) */ 124 int quant_tbl_no; /* quantization table selector (0..3) */ 125 /* These values may vary between scans. */ 126 /* For compression, they must be supplied by parameter setup; */ 127 /* for decompression, they are read from the SOS marker. */ 128 /* The decompressor output side may not use these variables. */ 129 int dc_tbl_no; /* DC entropy table selector (0..3) */ 130 int ac_tbl_no; /* AC entropy table selector (0..3) */ 131 132 /* Remaining fields should be treated as private by applications. */ 133 134 /* These values are computed during compression or decompression startup: */ 135 /* Component's size in DCT blocks. 136 * Any dummy blocks added to complete an MCU are not counted; therefore 137 * these values do not depend on whether a scan is interleaved or not. 138 */ 139 JDIMENSION width_in_blocks; 140 JDIMENSION height_in_blocks; 141 /* Size of a DCT block in samples. Always DCTSIZE for compression. 142 * For decompression this is the size of the output from one DCT block, 143 * reflecting any scaling we choose to apply during the IDCT step. 144 * Values of 1,2,4,8 are likely to be supported. Note that different 145 * components may receive different IDCT scalings. 146 */ 147 int DCT_scaled_size; 148 /* The downsampled dimensions are the component's actual, unpadded number 149 * of samples at the main buffer (preprocessing/compression interface), thus 150 * downsampled_width = ceil(image_width * Hi/Hmax) 151 * and similarly for height. For decompression, IDCT scaling is included, so 152 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_scaled_size/DCTSIZE) 153 */ 154 JDIMENSION downsampled_width; /* actual width in samples */ 155 JDIMENSION downsampled_height; /* actual height in samples */ 156 /* This flag is used only for decompression. In cases where some of the 157 * components will be ignored (eg grayscale output from YCbCr image), 158 * we can skip most computations for the unused components. 159 */ 160 boolean component_needed; /* do we need the value of this component? */ 161 162 /* These values are computed before starting a scan of the component. */ 163 /* The decompressor output side may not use these variables. */ 164 int MCU_width; /* number of blocks per MCU, horizontally */ 165 int MCU_height; /* number of blocks per MCU, vertically */ 166 int MCU_blocks; /* MCU_width * MCU_height */ 167 int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_scaled_size */ 168 int last_col_width; /* # of non-dummy blocks across in last MCU */ 169 int last_row_height; /* # of non-dummy blocks down in last MCU */ 170 171 /* Saved quantization table for component; NULL if none yet saved. 172 * See jdinput.c comments about the need for this information. 173 * This field is currently used only for decompression. 174 */ 175 JQUANT_TBL * quant_table; 176 177 /* Private per-component storage for DCT or IDCT subsystem. */ 178 void * dct_table; 179 } jpeg_component_info; 180 181 182 /* The script for encoding a multiple-scan file is an array of these: */ 183 184 typedef struct { 185 int comps_in_scan; /* number of components encoded in this scan */ 186 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */ 187 int Ss, Se; /* progressive JPEG spectral selection parms */ 188 int Ah, Al; /* progressive JPEG successive approx. parms */ 189 } jpeg_scan_info; 190 191 /* The decompressor can save APPn and COM markers in a list of these: */ 192 193 typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr; 194 195 struct jpeg_marker_struct { 196 jpeg_saved_marker_ptr next; /* next in list, or NULL */ 197 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */ 198 unsigned int original_length; /* # bytes of data in the file */ 199 unsigned int data_length; /* # bytes of data saved at data[] */ 200 JOCTET FAR * data; /* the data contained in the marker */ 201 /* the marker length word is not counted in data_length or original_length */ 202 }; 203 204 /* Known color spaces. */ 205 206 typedef enum { 207 JCS_UNKNOWN, /* error/unspecified */ 208 JCS_GRAYSCALE, /* monochrome */ 209 JCS_RGB, /* red/green/blue */ 210 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */ 211 JCS_CMYK, /* C/M/Y/K */ 212 JCS_YCCK, /* Y/Cb/Cr/K */ 213 #ifdef ANDROID_RGB 214 JCS_RGBA_8888, /* red/green/blue/alpha */ 215 JCS_RGB_565 /* red/green/blue in 565 format */ 216 #endif 217 } J_COLOR_SPACE; 218 219 /* DCT/IDCT algorithm options. */ 220 221 typedef enum { 222 JDCT_ISLOW, /* slow but accurate integer algorithm */ 223 JDCT_IFAST, /* faster, less accurate integer method */ 224 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */ 225 } J_DCT_METHOD; 226 227 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */ 228 #define JDCT_DEFAULT JDCT_ISLOW 229 #endif 230 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */ 231 #define JDCT_FASTEST JDCT_IFAST 232 #endif 233 234 /* Dithering options for decompression. */ 235 236 typedef enum { 237 JDITHER_NONE, /* no dithering */ 238 JDITHER_ORDERED, /* simple ordered dither */ 239 JDITHER_FS /* Floyd-Steinberg error diffusion dither */ 240 } J_DITHER_MODE; 241 242 243 /* Common fields between JPEG compression and decompression master structs. */ 244 245 #define jpeg_common_fields \ 246 struct jpeg_error_mgr * err; /* Error handler module */\ 247 struct jpeg_memory_mgr * mem; /* Memory manager module */\ 248 struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\ 249 void * client_data; /* Available for use by application */\ 250 boolean is_decompressor; /* So common code can tell which is which */\ 251 int global_state /* For checking call sequence validity */ 252 253 /* Routines that are to be used by both halves of the library are declared 254 * to receive a pointer to this structure. There are no actual instances of 255 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct. 256 */ 257 struct jpeg_common_struct { 258 jpeg_common_fields; /* Fields common to both master struct types */ 259 /* Additional fields follow in an actual jpeg_compress_struct or 260 * jpeg_decompress_struct. All three structs must agree on these 261 * initial fields! (This would be a lot cleaner in C++.) 262 */ 263 }; 264 265 typedef struct jpeg_common_struct * j_common_ptr; 266 typedef struct jpeg_compress_struct * j_compress_ptr; 267 typedef struct jpeg_decompress_struct * j_decompress_ptr; 268 269 270 /* Master record for a compression instance */ 271 272 struct jpeg_compress_struct { 273 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */ 274 275 /* Destination for compressed data */ 276 struct jpeg_destination_mgr * dest; 277 278 /* Description of source image --- these fields must be filled in by 279 * outer application before starting compression. in_color_space must 280 * be correct before you can even call jpeg_set_defaults(). 281 */ 282 283 JDIMENSION image_width; /* input image width */ 284 JDIMENSION image_height; /* input image height */ 285 int input_components; /* # of color components in input image */ 286 J_COLOR_SPACE in_color_space; /* colorspace of input image */ 287 288 double input_gamma; /* image gamma of input image */ 289 290 /* Compression parameters --- these fields must be set before calling 291 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to 292 * initialize everything to reasonable defaults, then changing anything 293 * the application specifically wants to change. That way you won't get 294 * burnt when new parameters are added. Also note that there are several 295 * helper routines to simplify changing parameters. 296 */ 297 298 int data_precision; /* bits of precision in image data */ 299 300 int num_components; /* # of color components in JPEG image */ 301 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 302 303 jpeg_component_info * comp_info; 304 /* comp_info[i] describes component that appears i'th in SOF */ 305 306 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 307 /* ptrs to coefficient quantization tables, or NULL if not defined */ 308 309 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 310 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 311 /* ptrs to Huffman coding tables, or NULL if not defined */ 312 313 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 314 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 315 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 316 317 int num_scans; /* # of entries in scan_info array */ 318 const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */ 319 /* The default value of scan_info is NULL, which causes a single-scan 320 * sequential JPEG file to be emitted. To create a multi-scan file, 321 * set num_scans and scan_info to point to an array of scan definitions. 322 */ 323 324 boolean raw_data_in; /* TRUE=caller supplies downsampled data */ 325 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 326 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */ 327 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 328 int smoothing_factor; /* 1..100, or 0 for no input smoothing */ 329 J_DCT_METHOD dct_method; /* DCT algorithm selector */ 330 331 /* The restart interval can be specified in absolute MCUs by setting 332 * restart_interval, or in MCU rows by setting restart_in_rows 333 * (in which case the correct restart_interval will be figured 334 * for each scan). 335 */ 336 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */ 337 int restart_in_rows; /* if > 0, MCU rows per restart interval */ 338 339 /* Parameters controlling emission of special markers. */ 340 341 boolean write_JFIF_header; /* should a JFIF marker be written? */ 342 UINT8 JFIF_major_version; /* What to write for the JFIF version number */ 343 UINT8 JFIF_minor_version; 344 /* These three values are not used by the JPEG code, merely copied */ 345 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */ 346 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */ 347 /* ratio is defined by X_density/Y_density even when density_unit=0. */ 348 UINT8 density_unit; /* JFIF code for pixel size units */ 349 UINT16 X_density; /* Horizontal pixel density */ 350 UINT16 Y_density; /* Vertical pixel density */ 351 boolean write_Adobe_marker; /* should an Adobe marker be written? */ 352 353 /* State variable: index of next scanline to be written to 354 * jpeg_write_scanlines(). Application may use this to control its 355 * processing loop, e.g., "while (next_scanline < image_height)". 356 */ 357 358 JDIMENSION next_scanline; /* 0 .. image_height-1 */ 359 360 /* Remaining fields are known throughout compressor, but generally 361 * should not be touched by a surrounding application. 362 */ 363 364 /* 365 * These fields are computed during compression startup 366 */ 367 boolean progressive_mode; /* TRUE if scan script uses progressive mode */ 368 int max_h_samp_factor; /* largest h_samp_factor */ 369 int max_v_samp_factor; /* largest v_samp_factor */ 370 371 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */ 372 /* The coefficient controller receives data in units of MCU rows as defined 373 * for fully interleaved scans (whether the JPEG file is interleaved or not). 374 * There are v_samp_factor * DCTSIZE sample rows of each component in an 375 * "iMCU" (interleaved MCU) row. 376 */ 377 378 /* 379 * These fields are valid during any one scan. 380 * They describe the components and MCUs actually appearing in the scan. 381 */ 382 int comps_in_scan; /* # of JPEG components in this scan */ 383 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 384 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 385 386 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 387 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 388 389 int blocks_in_MCU; /* # of DCT blocks per MCU */ 390 int MCU_membership[C_MAX_BLOCKS_IN_MCU]; 391 /* MCU_membership[i] is index in cur_comp_info of component owning */ 392 /* i'th block in an MCU */ 393 394 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 395 396 /* 397 * Links to compression subobjects (methods and private variables of modules) 398 */ 399 struct jpeg_comp_master * master; 400 struct jpeg_c_main_controller * main; 401 struct jpeg_c_prep_controller * prep; 402 struct jpeg_c_coef_controller * coef; 403 struct jpeg_marker_writer * marker; 404 struct jpeg_color_converter * cconvert; 405 struct jpeg_downsampler * downsample; 406 struct jpeg_forward_dct * fdct; 407 struct jpeg_entropy_encoder * entropy; 408 jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */ 409 int script_space_size; 410 }; 411 412 413 /* Master record for a decompression instance */ 414 415 struct jpeg_decompress_struct { 416 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */ 417 418 /* Source of compressed data */ 419 struct jpeg_source_mgr * src; 420 421 /* Basic description of image --- filled in by jpeg_read_header(). */ 422 /* Application may inspect these values to decide how to process image. */ 423 424 JDIMENSION original_image_width; /* nominal image width (from SOF marker) */ 425 426 JDIMENSION image_width; /* nominal image width (from SOF marker) 427 may be changed by tile decode */ 428 JDIMENSION image_height; /* nominal image height */ 429 int num_components; /* # of color components in JPEG image */ 430 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 431 432 /* Decompression processing parameters --- these fields must be set before 433 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes 434 * them to default values. 435 */ 436 437 J_COLOR_SPACE out_color_space; /* colorspace for output */ 438 439 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 440 441 double output_gamma; /* image gamma wanted in output */ 442 443 boolean buffered_image; /* TRUE=multiple output passes */ 444 boolean raw_data_out; /* TRUE=downsampled data wanted */ 445 446 J_DCT_METHOD dct_method; /* IDCT algorithm selector */ 447 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */ 448 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */ 449 450 boolean quantize_colors; /* TRUE=colormapped output wanted */ 451 /* the following are ignored if not quantize_colors: */ 452 J_DITHER_MODE dither_mode; /* type of color dithering to use */ 453 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */ 454 int desired_number_of_colors; /* max # colors to use in created colormap */ 455 /* these are significant only in buffered-image mode: */ 456 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */ 457 boolean enable_external_quant;/* enable future use of external colormap */ 458 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */ 459 460 /* Description of actual output image that will be returned to application. 461 * These fields are computed by jpeg_start_decompress(). 462 * You can also use jpeg_calc_output_dimensions() to determine these values 463 * in advance of calling jpeg_start_decompress(). 464 */ 465 466 JDIMENSION output_width; /* scaled image width */ 467 JDIMENSION output_height; /* scaled image height */ 468 int out_color_components; /* # of color components in out_color_space */ 469 int output_components; /* # of color components returned */ 470 /* output_components is 1 (a colormap index) when quantizing colors; 471 * otherwise it equals out_color_components. 472 */ 473 int rec_outbuf_height; /* min recommended height of scanline buffer */ 474 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows 475 * high, space and time will be wasted due to unnecessary data copying. 476 * Usually rec_outbuf_height will be 1 or 2, at most 4. 477 */ 478 479 /* When quantizing colors, the output colormap is described by these fields. 480 * The application can supply a colormap by setting colormap non-NULL before 481 * calling jpeg_start_decompress; otherwise a colormap is created during 482 * jpeg_start_decompress or jpeg_start_output. 483 * The map has out_color_components rows and actual_number_of_colors columns. 484 */ 485 int actual_number_of_colors; /* number of entries in use */ 486 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */ 487 488 /* State variables: these variables indicate the progress of decompression. 489 * The application may examine these but must not modify them. 490 */ 491 492 /* Row index of next scanline to be read from jpeg_read_scanlines(). 493 * Application may use this to control its processing loop, e.g., 494 * "while (output_scanline < output_height)". 495 */ 496 JDIMENSION output_scanline; /* 0 .. output_height-1 */ 497 498 /* Current input scan number and number of iMCU rows completed in scan. 499 * These indicate the progress of the decompressor input side. 500 */ 501 int input_scan_number; /* Number of SOS markers seen so far */ 502 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */ 503 504 /* The "output scan number" is the notional scan being displayed by the 505 * output side. The decompressor will not allow output scan/row number 506 * to get ahead of input scan/row, but it can fall arbitrarily far behind. 507 */ 508 int output_scan_number; /* Nominal scan number being displayed */ 509 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */ 510 511 /* Current progression status. coef_bits[c][i] indicates the precision 512 * with which component c's DCT coefficient i (in zigzag order) is known. 513 * It is -1 when no data has yet been received, otherwise it is the point 514 * transform (shift) value for the most recent scan of the coefficient 515 * (thus, 0 at completion of the progression). 516 * This pointer is NULL when reading a non-progressive file. 517 */ 518 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */ 519 520 /* Internal JPEG parameters --- the application usually need not look at 521 * these fields. Note that the decompressor output side may not use 522 * any parameters that can change between scans. 523 */ 524 525 /* Quantization and Huffman tables are carried forward across input 526 * datastreams when processing abbreviated JPEG datastreams. 527 */ 528 529 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 530 /* ptrs to coefficient quantization tables, or NULL if not defined */ 531 532 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 533 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 534 /* ptrs to Huffman coding tables, or NULL if not defined */ 535 536 /* These parameters are never carried across datastreams, since they 537 * are given in SOF/SOS markers or defined to be reset by SOI. 538 */ 539 540 int data_precision; /* bits of precision in image data */ 541 542 jpeg_component_info * comp_info; 543 /* comp_info[i] describes component that appears i'th in SOF */ 544 545 boolean tile_decode; /* TRUE if using tile based decoding */ 546 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */ 547 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 548 549 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 550 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 551 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 552 553 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */ 554 555 /* These fields record data obtained from optional markers recognized by 556 * the JPEG library. 557 */ 558 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */ 559 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */ 560 UINT8 JFIF_major_version; /* JFIF version number */ 561 UINT8 JFIF_minor_version; 562 UINT8 density_unit; /* JFIF code for pixel size units */ 563 UINT16 X_density; /* Horizontal pixel density */ 564 UINT16 Y_density; /* Vertical pixel density */ 565 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */ 566 UINT8 Adobe_transform; /* Color transform code from Adobe marker */ 567 568 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 569 570 /* Aside from the specific data retained from APPn markers known to the 571 * library, the uninterpreted contents of any or all APPn and COM markers 572 * can be saved in a list for examination by the application. 573 */ 574 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */ 575 576 /* Remaining fields are known throughout decompressor, but generally 577 * should not be touched by a surrounding application. 578 */ 579 580 /* 581 * These fields are computed during decompression startup 582 */ 583 int max_h_samp_factor; /* largest h_samp_factor */ 584 int max_v_samp_factor; /* largest v_samp_factor */ 585 586 int min_DCT_scaled_size; /* smallest DCT_scaled_size of any component */ 587 588 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */ 589 /* The coefficient controller's input and output progress is measured in 590 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows 591 * in fully interleaved JPEG scans, but are used whether the scan is 592 * interleaved or not. We define an iMCU row as v_samp_factor DCT block 593 * rows of each component. Therefore, the IDCT output contains 594 * v_samp_factor*DCT_scaled_size sample rows of a component per iMCU row. 595 */ 596 597 JSAMPLE * sample_range_limit; /* table for fast range-limiting */ 598 599 /* 600 * These fields are valid during any one scan. 601 * They describe the components and MCUs actually appearing in the scan. 602 * Note that the decompressor output side must not use these fields. 603 */ 604 int comps_in_scan; /* # of JPEG components in this scan */ 605 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 606 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 607 608 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 609 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 610 611 int blocks_in_MCU; /* # of DCT blocks per MCU */ 612 int MCU_membership[D_MAX_BLOCKS_IN_MCU]; 613 /* MCU_membership[i] is index in cur_comp_info of component owning */ 614 /* i'th block in an MCU */ 615 616 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 617 618 /* This field is shared between entropy decoder and marker parser. 619 * It is either zero or the code of a JPEG marker that has been 620 * read from the data source, but has not yet been processed. 621 */ 622 int unread_marker; 623 624 /* 625 * Links to decompression subobjects (methods, private variables of modules) 626 */ 627 struct jpeg_decomp_master * master; 628 struct jpeg_d_main_controller * main; 629 struct jpeg_d_coef_controller * coef; 630 struct jpeg_d_post_controller * post; 631 struct jpeg_input_controller * inputctl; 632 struct jpeg_marker_reader * marker; 633 struct jpeg_entropy_decoder * entropy; 634 struct jpeg_inverse_dct * idct; 635 struct jpeg_upsampler * upsample; 636 struct jpeg_color_deconverter * cconvert; 637 struct jpeg_color_quantizer * cquantize; 638 }; 639 640 typedef struct { 641 642 // |--- byte_offset ---|- bit_left -| 643 // \------ 27 -------/ \---- 5 ----/ 644 unsigned int bitstream_offset; 645 short prev_dc[3]; 646 647 // remaining EOBs in EOBRUN 648 unsigned short EOBRUN; 649 650 // save the decoder current bit buffer, entropy->bitstate.get_buffer. 651 INT32 get_buffer; 652 653 // save the restart info. 654 unsigned short restarts_to_go; 655 unsigned char next_restart_num; 656 } huffman_offset_data; 657 658 typedef struct { 659 660 // The header starting position of this scan 661 unsigned int bitstream_offset; 662 663 // Number of components in this scan 664 int comps_in_scan; 665 666 // Number of MCUs in each row 667 int MCUs_per_row; 668 int MCU_rows_per_iMCU_row; 669 670 // The last MCU position and its dc value in this scan 671 huffman_offset_data prev_MCU_offset; 672 673 huffman_offset_data **offset; 674 } huffman_scan_header; 675 676 #define DEFAULT_MCU_SAMPLE_SIZE 16 677 678 typedef struct { 679 680 // The number of MCUs that we sample each time as an index point 681 int MCU_sample_size; 682 683 // Number of scan in this image 684 int scan_count; 685 686 // Number of iMCUs rows in this image 687 int total_iMCU_rows; 688 689 // Memory used by scan struct 690 size_t mem_used; 691 huffman_scan_header *scan; 692 } huffman_index; 693 694 /* "Object" declarations for JPEG modules that may be supplied or called 695 * directly by the surrounding application. 696 * As with all objects in the JPEG library, these structs only define the 697 * publicly visible methods and state variables of a module. Additional 698 * private fields may exist after the public ones. 699 */ 700 701 702 /* Error handler object */ 703 704 struct jpeg_error_mgr { 705 /* Error exit handler: does not return to caller */ 706 JMETHOD(void, error_exit, (j_common_ptr cinfo)); 707 /* Conditionally emit a trace or warning message */ 708 JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level)); 709 /* Routine that actually outputs a trace or error message */ 710 JMETHOD(void, output_message, (j_common_ptr cinfo)); 711 /* Format a message string for the most recent JPEG error or message */ 712 JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer)); 713 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */ 714 /* Reset error state variables at start of a new image */ 715 JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo)); 716 717 /* The message ID code and any parameters are saved here. 718 * A message can have one string parameter or up to 8 int parameters. 719 */ 720 int msg_code; 721 #define JMSG_STR_PARM_MAX 80 722 union { 723 int i[8]; 724 char s[JMSG_STR_PARM_MAX]; 725 } msg_parm; 726 727 /* Standard state variables for error facility */ 728 729 int trace_level; /* max msg_level that will be displayed */ 730 731 /* For recoverable corrupt-data errors, we emit a warning message, 732 * but keep going unless emit_message chooses to abort. emit_message 733 * should count warnings in num_warnings. The surrounding application 734 * can check for bad data by seeing if num_warnings is nonzero at the 735 * end of processing. 736 */ 737 long num_warnings; /* number of corrupt-data warnings */ 738 739 /* These fields point to the table(s) of error message strings. 740 * An application can change the table pointer to switch to a different 741 * message list (typically, to change the language in which errors are 742 * reported). Some applications may wish to add additional error codes 743 * that will be handled by the JPEG library error mechanism; the second 744 * table pointer is used for this purpose. 745 * 746 * First table includes all errors generated by JPEG library itself. 747 * Error code 0 is reserved for a "no such error string" message. 748 */ 749 const char * const * jpeg_message_table; /* Library errors */ 750 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */ 751 /* Second table can be added by application (see cjpeg/djpeg for example). 752 * It contains strings numbered first_addon_message..last_addon_message. 753 */ 754 const char * const * addon_message_table; /* Non-library errors */ 755 int first_addon_message; /* code for first string in addon table */ 756 int last_addon_message; /* code for last string in addon table */ 757 }; 758 759 760 /* Progress monitor object */ 761 762 struct jpeg_progress_mgr { 763 JMETHOD(void, progress_monitor, (j_common_ptr cinfo)); 764 765 long pass_counter; /* work units completed in this pass */ 766 long pass_limit; /* total number of work units in this pass */ 767 int completed_passes; /* passes completed so far */ 768 int total_passes; /* total number of passes expected */ 769 }; 770 771 772 /* Data destination object for compression */ 773 774 struct jpeg_destination_mgr { 775 JOCTET * next_output_byte; /* => next byte to write in buffer */ 776 size_t free_in_buffer; /* # of byte spaces remaining in buffer */ 777 778 JMETHOD(void, init_destination, (j_compress_ptr cinfo)); 779 JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo)); 780 JMETHOD(void, term_destination, (j_compress_ptr cinfo)); 781 }; 782 783 784 /* Data source object for decompression */ 785 786 struct jpeg_source_mgr { 787 const JOCTET * next_input_byte; /* => next byte to read from buffer */ 788 const JOCTET * start_input_byte; /* => first byte to read from input */ 789 size_t bytes_in_buffer; /* # of bytes remaining in buffer */ 790 size_t current_offset; /* current readed input offset */ 791 792 JMETHOD(void, init_source, (j_decompress_ptr cinfo)); 793 JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo)); 794 JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes)); 795 JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired)); 796 JMETHOD(void, term_source, (j_decompress_ptr cinfo)); 797 JMETHOD(boolean, seek_input_data, (j_decompress_ptr cinfo, long byte_offset)); 798 }; 799 800 801 /* Memory manager object. 802 * Allocates "small" objects (a few K total), "large" objects (tens of K), 803 * and "really big" objects (virtual arrays with backing store if needed). 804 * The memory manager does not allow individual objects to be freed; rather, 805 * each created object is assigned to a pool, and whole pools can be freed 806 * at once. This is faster and more convenient than remembering exactly what 807 * to free, especially where malloc()/free() are not too speedy. 808 * NB: alloc routines never return NULL. They exit to error_exit if not 809 * successful. 810 */ 811 812 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */ 813 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */ 814 #define JPOOL_NUMPOOLS 2 815 816 typedef struct jvirt_sarray_control * jvirt_sarray_ptr; 817 typedef struct jvirt_barray_control * jvirt_barray_ptr; 818 819 820 struct jpeg_memory_mgr { 821 /* Method pointers */ 822 JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id, 823 size_t sizeofobject)); 824 JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id, 825 size_t sizeofobject)); 826 JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id, 827 JDIMENSION samplesperrow, 828 JDIMENSION numrows)); 829 JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id, 830 JDIMENSION blocksperrow, 831 JDIMENSION numrows)); 832 JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo, 833 int pool_id, 834 boolean pre_zero, 835 JDIMENSION samplesperrow, 836 JDIMENSION numrows, 837 JDIMENSION maxaccess)); 838 JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo, 839 int pool_id, 840 boolean pre_zero, 841 JDIMENSION blocksperrow, 842 JDIMENSION numrows, 843 JDIMENSION maxaccess)); 844 JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo)); 845 JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo, 846 jvirt_sarray_ptr ptr, 847 JDIMENSION start_row, 848 JDIMENSION num_rows, 849 boolean writable)); 850 JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo, 851 jvirt_barray_ptr ptr, 852 JDIMENSION start_row, 853 JDIMENSION num_rows, 854 boolean writable)); 855 JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id)); 856 JMETHOD(void, self_destruct, (j_common_ptr cinfo)); 857 858 /* Limit on memory allocation for this JPEG object. (Note that this is 859 * merely advisory, not a guaranteed maximum; it only affects the space 860 * used for virtual-array buffers.) May be changed by outer application 861 * after creating the JPEG object. 862 */ 863 long max_memory_to_use; 864 865 /* Maximum allocation request accepted by alloc_large. */ 866 long max_alloc_chunk; 867 }; 868 869 870 /* Routine signature for application-supplied marker processing methods. 871 * Need not pass marker code since it is stored in cinfo->unread_marker. 872 */ 873 typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo)); 874 875 876 /* Declarations for routines called by application. 877 * The JPP macro hides prototype parameters from compilers that can't cope. 878 * Note JPP requires double parentheses. 879 */ 880 881 #ifdef HAVE_PROTOTYPES 882 #define JPP(arglist) arglist 883 #else 884 #define JPP(arglist) () 885 #endif 886 887 888 /* Short forms of external names for systems with brain-damaged linkers. 889 * We shorten external names to be unique in the first six letters, which 890 * is good enough for all known systems. 891 * (If your compiler itself needs names to be unique in less than 15 892 * characters, you are out of luck. Get a better compiler.) 893 */ 894 895 #ifdef NEED_SHORT_EXTERNAL_NAMES 896 #define jpeg_std_error jStdError 897 #define jpeg_CreateCompress jCreaCompress 898 #define jpeg_CreateDecompress jCreaDecompress 899 #define jpeg_destroy_compress jDestCompress 900 #define jpeg_destroy_decompress jDestDecompress 901 #define jpeg_stdio_dest jStdDest 902 #define jpeg_stdio_src jStdSrc 903 #define jpeg_set_defaults jSetDefaults 904 #define jpeg_set_colorspace jSetColorspace 905 #define jpeg_default_colorspace jDefColorspace 906 #define jpeg_set_quality jSetQuality 907 #define jpeg_set_linear_quality jSetLQuality 908 #define jpeg_add_quant_table jAddQuantTable 909 #define jpeg_quality_scaling jQualityScaling 910 #define jpeg_simple_progression jSimProgress 911 #define jpeg_suppress_tables jSuppressTables 912 #define jpeg_alloc_quant_table jAlcQTable 913 #define jpeg_alloc_huff_table jAlcHTable 914 #define jpeg_start_compress jStrtCompress 915 #define jpeg_write_scanlines jWrtScanlines 916 #define jpeg_finish_compress jFinCompress 917 #define jpeg_write_raw_data jWrtRawData 918 #define jpeg_write_marker jWrtMarker 919 #define jpeg_write_m_header jWrtMHeader 920 #define jpeg_write_m_byte jWrtMByte 921 #define jpeg_write_tables jWrtTables 922 #define jpeg_read_header jReadHeader 923 #define jpeg_start_decompress jStrtDecompress 924 #define jpeg_read_scanlines jReadScanlines 925 #define jpeg_finish_decompress jFinDecompress 926 #define jpeg_read_raw_data jReadRawData 927 #define jpeg_has_multiple_scans jHasMultScn 928 #define jpeg_start_output jStrtOutput 929 #define jpeg_finish_output jFinOutput 930 #define jpeg_input_complete jInComplete 931 #define jpeg_new_colormap jNewCMap 932 #define jpeg_consume_input jConsumeInput 933 #define jpeg_calc_output_dimensions jCalcDimensions 934 #define jpeg_save_markers jSaveMarkers 935 #define jpeg_set_marker_processor jSetMarker 936 #define jpeg_read_coefficients jReadCoefs 937 #define jpeg_write_coefficients jWrtCoefs 938 #define jpeg_copy_critical_parameters jCopyCrit 939 #define jpeg_abort_compress jAbrtCompress 940 #define jpeg_abort_decompress jAbrtDecompress 941 #define jpeg_abort jAbort 942 #define jpeg_destroy jDestroy 943 #define jpeg_resync_to_restart jResyncRestart 944 #endif /* NEED_SHORT_EXTERNAL_NAMES */ 945 946 947 /* Default error-management setup */ 948 EXTERN(struct jpeg_error_mgr *) jpeg_std_error 949 JPP((struct jpeg_error_mgr * err)); 950 951 /* Initialization of JPEG compression objects. 952 * jpeg_create_compress() and jpeg_create_decompress() are the exported 953 * names that applications should call. These expand to calls on 954 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information 955 * passed for version mismatch checking. 956 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx. 957 */ 958 #define jpeg_create_compress(cinfo) \ 959 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \ 960 (size_t) sizeof(struct jpeg_compress_struct)) 961 #define jpeg_create_decompress(cinfo) \ 962 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \ 963 (size_t) sizeof(struct jpeg_decompress_struct)) 964 EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo, 965 int version, size_t structsize)); 966 EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo, 967 int version, size_t structsize)); 968 /* Destruction of JPEG compression objects */ 969 EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo)); 970 EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo)); 971 972 /* Standard data source and destination managers: stdio streams. */ 973 /* Caller is responsible for opening the file before and closing after. */ 974 EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile)); 975 EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile)); 976 977 /* Default parameter setup for compression */ 978 EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo)); 979 /* Compression parameter setup aids */ 980 EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo, 981 J_COLOR_SPACE colorspace)); 982 EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo)); 983 EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality, 984 boolean force_baseline)); 985 EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo, 986 int scale_factor, 987 boolean force_baseline)); 988 EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl, 989 const unsigned int *basic_table, 990 int scale_factor, 991 boolean force_baseline)); 992 EXTERN(int) jpeg_quality_scaling JPP((int quality)); 993 EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo)); 994 EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo, 995 boolean suppress)); 996 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo)); 997 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo)); 998 999 /* Main entry points for compression */ 1000 EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo, 1001 boolean write_all_tables)); 1002 EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo, 1003 JSAMPARRAY scanlines, 1004 JDIMENSION num_lines)); 1005 EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo)); 1006 1007 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */ 1008 EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo, 1009 JSAMPIMAGE data, 1010 JDIMENSION num_lines)); 1011 1012 /* Write a special marker. See libjpeg.doc concerning safe usage. */ 1013 EXTERN(void) jpeg_write_marker 1014 JPP((j_compress_ptr cinfo, int marker, 1015 const JOCTET * dataptr, unsigned int datalen)); 1016 /* Same, but piecemeal. */ 1017 EXTERN(void) jpeg_write_m_header 1018 JPP((j_compress_ptr cinfo, int marker, unsigned int datalen)); 1019 EXTERN(void) jpeg_write_m_byte 1020 JPP((j_compress_ptr cinfo, int val)); 1021 1022 /* Alternate compression function: just write an abbreviated table file */ 1023 EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo)); 1024 1025 /* Decompression startup: read start of JPEG datastream to see what's there */ 1026 EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo, 1027 boolean require_image)); 1028 /* Return value is one of: */ 1029 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */ 1030 #define JPEG_HEADER_OK 1 /* Found valid image datastream */ 1031 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */ 1032 /* If you pass require_image = TRUE (normal case), you need not check for 1033 * a TABLES_ONLY return code; an abbreviated file will cause an error exit. 1034 * JPEG_SUSPENDED is only possible if you use a data source module that can 1035 * give a suspension return (the stdio source module doesn't). 1036 */ 1037 1038 /* Main entry points for decompression */ 1039 EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo)); 1040 EXTERN(boolean) jpeg_start_tile_decompress JPP((j_decompress_ptr cinfo)); 1041 EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo, 1042 JSAMPARRAY scanlines, 1043 JDIMENSION max_lines)); 1044 EXTERN(JDIMENSION) jpeg_read_scanlines_from JPP((j_decompress_ptr cinfo, 1045 JSAMPARRAY scanlines, 1046 int line_offset, 1047 JDIMENSION max_lines)); 1048 EXTERN(JDIMENSION) jpeg_read_tile_scanline JPP((j_decompress_ptr cinfo, 1049 huffman_index *index, 1050 JSAMPARRAY scanlines)); 1051 EXTERN(void) jpeg_init_read_tile_scanline JPP((j_decompress_ptr cinfo, 1052 huffman_index *index, 1053 int *start_x, int *start_y, 1054 int *width, int *height)); 1055 EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo)); 1056 1057 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */ 1058 EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo, 1059 JSAMPIMAGE data, 1060 JDIMENSION max_lines)); 1061 1062 /* Additional entry points for buffered-image mode. */ 1063 EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo)); 1064 EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo, 1065 int scan_number)); 1066 EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo)); 1067 EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo)); 1068 EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo)); 1069 EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo)); 1070 /* Return value is one of: */ 1071 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */ 1072 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */ 1073 #define JPEG_REACHED_EOI 2 /* Reached end of image */ 1074 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */ 1075 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */ 1076 1077 /* Precalculate output dimensions for current decompression parameters. */ 1078 EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo)); 1079 1080 /* Control saving of COM and APPn markers into marker_list. */ 1081 EXTERN(void) jpeg_save_markers 1082 JPP((j_decompress_ptr cinfo, int marker_code, 1083 unsigned int length_limit)); 1084 1085 /* Install a special processing method for COM or APPn markers. */ 1086 EXTERN(void) jpeg_set_marker_processor 1087 JPP((j_decompress_ptr cinfo, int marker_code, 1088 jpeg_marker_parser_method routine)); 1089 1090 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */ 1091 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo)); 1092 EXTERN(boolean) jpeg_build_huffman_index 1093 JPP((j_decompress_ptr cinfo, huffman_index *index)); 1094 EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo, 1095 jvirt_barray_ptr * coef_arrays)); 1096 EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo, 1097 j_compress_ptr dstinfo)); 1098 1099 /* If you choose to abort compression or decompression before completing 1100 * jpeg_finish_(de)compress, then you need to clean up to release memory, 1101 * temporary files, etc. You can just call jpeg_destroy_(de)compress 1102 * if you're done with the JPEG object, but if you want to clean it up and 1103 * reuse it, call this: 1104 */ 1105 EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo)); 1106 EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo)); 1107 1108 /* Generic versions of jpeg_abort and jpeg_destroy that work on either 1109 * flavor of JPEG object. These may be more convenient in some places. 1110 */ 1111 EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo)); 1112 EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo)); 1113 1114 /* Default restart-marker-resync procedure for use by data source modules */ 1115 EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo, 1116 int desired)); 1117 1118 EXTERN(void) jpeg_configure_huffman_decoder(j_decompress_ptr cinfo, 1119 huffman_offset_data offset); 1120 EXTERN(void) jpeg_get_huffman_decoder_configuration(j_decompress_ptr cinfo, 1121 huffman_offset_data *offset); 1122 EXTERN(void) jpeg_create_huffman_index(j_decompress_ptr cinfo, 1123 huffman_index *index); 1124 EXTERN(void) jpeg_configure_huffman_index_scan(j_decompress_ptr cinfo, 1125 huffman_index *index, int scan_no, int offset); 1126 EXTERN(void) jpeg_destroy_huffman_index(huffman_index *index); 1127 1128 1129 /* These marker codes are exported since applications and data source modules 1130 * are likely to want to use them. 1131 */ 1132 1133 #define JPEG_RST0 0xD0 /* RST0 marker code */ 1134 #define JPEG_EOI 0xD9 /* EOI marker code */ 1135 #define JPEG_APP0 0xE0 /* APP0 marker code */ 1136 #define JPEG_COM 0xFE /* COM marker code */ 1137 1138 1139 /* If we have a brain-damaged compiler that emits warnings (or worse, errors) 1140 * for structure definitions that are never filled in, keep it quiet by 1141 * supplying dummy definitions for the various substructures. 1142 */ 1143 1144 #ifdef INCOMPLETE_TYPES_BROKEN 1145 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */ 1146 struct jvirt_sarray_control { long dummy; }; 1147 struct jvirt_barray_control { long dummy; }; 1148 struct jpeg_comp_master { long dummy; }; 1149 struct jpeg_c_main_controller { long dummy; }; 1150 struct jpeg_c_prep_controller { long dummy; }; 1151 struct jpeg_c_coef_controller { long dummy; }; 1152 struct jpeg_marker_writer { long dummy; }; 1153 struct jpeg_color_converter { long dummy; }; 1154 struct jpeg_downsampler { long dummy; }; 1155 struct jpeg_forward_dct { long dummy; }; 1156 struct jpeg_entropy_encoder { long dummy; }; 1157 struct jpeg_decomp_master { long dummy; }; 1158 struct jpeg_d_main_controller { long dummy; }; 1159 struct jpeg_d_coef_controller { long dummy; }; 1160 struct jpeg_d_post_controller { long dummy; }; 1161 struct jpeg_input_controller { long dummy; }; 1162 struct jpeg_marker_reader { long dummy; }; 1163 struct jpeg_entropy_decoder { long dummy; }; 1164 struct jpeg_inverse_dct { long dummy; }; 1165 struct jpeg_upsampler { long dummy; }; 1166 struct jpeg_color_deconverter { long dummy; }; 1167 struct jpeg_color_quantizer { long dummy; }; 1168 #endif /* JPEG_INTERNALS */ 1169 #endif /* INCOMPLETE_TYPES_BROKEN */ 1170 1171 1172 /* 1173 * The JPEG library modules define JPEG_INTERNALS before including this file. 1174 * The internal structure declarations are read only when that is true. 1175 * Applications using the library should not include jpegint.h, but may wish 1176 * to include jerror.h. 1177 */ 1178 1179 #ifdef JPEG_INTERNALS 1180 #include "jpegint.h" /* fetch private declarations */ 1181 #include "jerror.h" /* fetch error codes too */ 1182 #endif 1183 1184 #endif /* JPEGLIB_H */ 1185
