1 /* 2 * jpeglib.h 3 * 4 * Copyright (C) 1991-1998, Thomas G. Lane. 5 * Modified 2002-2010 by Guido Vollbeding. 6 * This file is part of the Independent JPEG Group's software. 7 * For conditions of distribution and use, see the accompanying README file. 8 * 9 * This file defines the application interface for the JPEG library. 10 * Most applications using the library need only include this file, 11 * and perhaps jerror.h if they want to know the exact error codes. 12 */ 13 14 #ifndef JPEGLIB_H 15 #define JPEGLIB_H 16 17 /* 18 * First we include the configuration files that record how this 19 * installation of the JPEG library is set up. jconfig.h can be 20 * generated automatically for many systems. jmorecfg.h contains 21 * manual configuration options that most people need not worry about. 22 */ 23 24 #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */ 25 #include "jconfig.h" /* widely used configuration options */ 26 #endif 27 #include "jmorecfg.h" /* seldom changed options */ 28 29 30 #ifdef __cplusplus 31 #ifndef DONT_USE_EXTERN_C 32 extern "C" { 33 #endif 34 #endif 35 36 /* Version IDs for the JPEG library. 37 * Might be useful for tests like "#if JPEG_LIB_VERSION >= 80". 38 */ 39 40 #define JPEG_LIB_VERSION 80 /* Compatibility version 8.0 */ 41 #define JPEG_LIB_VERSION_MAJOR 8 42 #define JPEG_LIB_VERSION_MINOR 3 43 44 45 /* Various constants determining the sizes of things. 46 * All of these are specified by the JPEG standard, so don't change them 47 * if you want to be compatible. 48 */ 49 50 #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */ 51 #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */ 52 #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */ 53 #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */ 54 #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */ 55 #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */ 56 #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */ 57 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard; 58 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU. 59 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU 60 * to handle it. We even let you do this from the jconfig.h file. However, 61 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe 62 * sometimes emits noncompliant files doesn't mean you should too. 63 */ 64 #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */ 65 #ifndef D_MAX_BLOCKS_IN_MCU 66 #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */ 67 #endif 68 69 70 /* Data structures for images (arrays of samples and of DCT coefficients). 71 * On 80x86 machines, the image arrays are too big for near pointers, 72 * but the pointer arrays can fit in near memory. 73 */ 74 75 typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */ 76 typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */ 77 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */ 78 79 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */ 80 typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */ 81 typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */ 82 typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */ 83 84 typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */ 85 86 87 /* Types for JPEG compression parameters and working tables. */ 88 89 90 /* DCT coefficient quantization tables. */ 91 92 typedef struct { 93 /* This array gives the coefficient quantizers in natural array order 94 * (not the zigzag order in which they are stored in a JPEG DQT marker). 95 * CAUTION: IJG versions prior to v6a kept this array in zigzag order. 96 */ 97 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */ 98 /* This field is used only during compression. It's initialized FALSE when 99 * the table is created, and set TRUE when it's been output to the file. 100 * You could suppress output of a table by setting this to TRUE. 101 * (See jpeg_suppress_tables for an example.) 102 */ 103 boolean sent_table; /* TRUE when table has been output */ 104 } JQUANT_TBL; 105 106 107 /* Huffman coding tables. */ 108 109 typedef struct { 110 /* These two fields directly represent the contents of a JPEG DHT marker */ 111 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */ 112 /* length k bits; bits[0] is unused */ 113 UINT8 huffval[256]; /* The symbols, in order of incr code length */ 114 /* This field is used only during compression. It's initialized FALSE when 115 * the table is created, and set TRUE when it's been output to the file. 116 * You could suppress output of a table by setting this to TRUE. 117 * (See jpeg_suppress_tables for an example.) 118 */ 119 boolean sent_table; /* TRUE when table has been output */ 120 } JHUFF_TBL; 121 122 123 /* Basic info about one component (color channel). */ 124 125 typedef struct { 126 /* These values are fixed over the whole image. */ 127 /* For compression, they must be supplied by parameter setup; */ 128 /* for decompression, they are read from the SOF marker. */ 129 int component_id; /* identifier for this component (0..255) */ 130 int component_index; /* its index in SOF or cinfo->comp_info[] */ 131 int h_samp_factor; /* horizontal sampling factor (1..4) */ 132 int v_samp_factor; /* vertical sampling factor (1..4) */ 133 int quant_tbl_no; /* quantization table selector (0..3) */ 134 /* These values may vary between scans. */ 135 /* For compression, they must be supplied by parameter setup; */ 136 /* for decompression, they are read from the SOS marker. */ 137 /* The decompressor output side may not use these variables. */ 138 int dc_tbl_no; /* DC entropy table selector (0..3) */ 139 int ac_tbl_no; /* AC entropy table selector (0..3) */ 140 141 /* Remaining fields should be treated as private by applications. */ 142 143 /* These values are computed during compression or decompression startup: */ 144 /* Component's size in DCT blocks. 145 * Any dummy blocks added to complete an MCU are not counted; therefore 146 * these values do not depend on whether a scan is interleaved or not. 147 */ 148 JDIMENSION width_in_blocks; 149 JDIMENSION height_in_blocks; 150 /* Size of a DCT block in samples, 151 * reflecting any scaling we choose to apply during the DCT step. 152 * Values from 1 to 16 are supported. 153 * Note that different components may receive different DCT scalings. 154 */ 155 int DCT_h_scaled_size; 156 int DCT_v_scaled_size; 157 /* The downsampled dimensions are the component's actual, unpadded number 158 * of samples at the main buffer (preprocessing/compression interface); 159 * DCT scaling is included, so 160 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_h_scaled_size/DCTSIZE) 161 * and similarly for height. 162 */ 163 JDIMENSION downsampled_width; /* actual width in samples */ 164 JDIMENSION downsampled_height; /* actual height in samples */ 165 /* This flag is used only for decompression. In cases where some of the 166 * components will be ignored (eg grayscale output from YCbCr image), 167 * we can skip most computations for the unused components. 168 */ 169 boolean component_needed; /* do we need the value of this component? */ 170 171 /* These values are computed before starting a scan of the component. */ 172 /* The decompressor output side may not use these variables. */ 173 int MCU_width; /* number of blocks per MCU, horizontally */ 174 int MCU_height; /* number of blocks per MCU, vertically */ 175 int MCU_blocks; /* MCU_width * MCU_height */ 176 int MCU_sample_width; /* MCU width in samples: MCU_width * DCT_h_scaled_size */ 177 int last_col_width; /* # of non-dummy blocks across in last MCU */ 178 int last_row_height; /* # of non-dummy blocks down in last MCU */ 179 180 /* Saved quantization table for component; NULL if none yet saved. 181 * See jdinput.c comments about the need for this information. 182 * This field is currently used only for decompression. 183 */ 184 JQUANT_TBL * quant_table; 185 186 /* Private per-component storage for DCT or IDCT subsystem. */ 187 void * dct_table; 188 } jpeg_component_info; 189 190 191 /* The script for encoding a multiple-scan file is an array of these: */ 192 193 typedef struct { 194 int comps_in_scan; /* number of components encoded in this scan */ 195 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */ 196 int Ss, Se; /* progressive JPEG spectral selection parms */ 197 int Ah, Al; /* progressive JPEG successive approx. parms */ 198 } jpeg_scan_info; 199 200 /* The decompressor can save APPn and COM markers in a list of these: */ 201 202 typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr; 203 204 struct jpeg_marker_struct { 205 jpeg_saved_marker_ptr next; /* next in list, or NULL */ 206 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */ 207 unsigned int original_length; /* # bytes of data in the file */ 208 unsigned int data_length; /* # bytes of data saved at data[] */ 209 JOCTET FAR * data; /* the data contained in the marker */ 210 /* the marker length word is not counted in data_length or original_length */ 211 }; 212 213 /* Known color spaces. */ 214 215 typedef enum { 216 JCS_UNKNOWN, /* error/unspecified */ 217 JCS_GRAYSCALE, /* monochrome */ 218 JCS_RGB, /* red/green/blue */ 219 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */ 220 JCS_CMYK, /* C/M/Y/K */ 221 JCS_YCCK /* Y/Cb/Cr/K */ 222 } J_COLOR_SPACE; 223 224 /* DCT/IDCT algorithm options. */ 225 226 typedef enum { 227 JDCT_ISLOW, /* slow but accurate integer algorithm */ 228 JDCT_IFAST, /* faster, less accurate integer method */ 229 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */ 230 } J_DCT_METHOD; 231 232 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */ 233 #define JDCT_DEFAULT JDCT_ISLOW 234 #endif 235 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */ 236 #define JDCT_FASTEST JDCT_IFAST 237 #endif 238 239 /* Dithering options for decompression. */ 240 241 typedef enum { 242 JDITHER_NONE, /* no dithering */ 243 JDITHER_ORDERED, /* simple ordered dither */ 244 JDITHER_FS /* Floyd-Steinberg error diffusion dither */ 245 } J_DITHER_MODE; 246 247 248 /* Common fields between JPEG compression and decompression master structs. */ 249 250 #define jpeg_common_fields \ 251 struct jpeg_error_mgr * err; /* Error handler module */\ 252 struct jpeg_memory_mgr * mem; /* Memory manager module */\ 253 struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\ 254 void * client_data; /* Available for use by application */\ 255 boolean is_decompressor; /* So common code can tell which is which */\ 256 int global_state /* For checking call sequence validity */ 257 258 /* Routines that are to be used by both halves of the library are declared 259 * to receive a pointer to this structure. There are no actual instances of 260 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct. 261 */ 262 struct jpeg_common_struct { 263 jpeg_common_fields; /* Fields common to both master struct types */ 264 /* Additional fields follow in an actual jpeg_compress_struct or 265 * jpeg_decompress_struct. All three structs must agree on these 266 * initial fields! (This would be a lot cleaner in C++.) 267 */ 268 }; 269 270 typedef struct jpeg_common_struct * j_common_ptr; 271 typedef struct jpeg_compress_struct * j_compress_ptr; 272 typedef struct jpeg_decompress_struct * j_decompress_ptr; 273 274 275 /* Master record for a compression instance */ 276 277 struct jpeg_compress_struct { 278 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */ 279 280 /* Destination for compressed data */ 281 struct jpeg_destination_mgr * dest; 282 283 /* Description of source image --- these fields must be filled in by 284 * outer application before starting compression. in_color_space must 285 * be correct before you can even call jpeg_set_defaults(). 286 */ 287 288 JDIMENSION image_width; /* input image width */ 289 JDIMENSION image_height; /* input image height */ 290 int input_components; /* # of color components in input image */ 291 J_COLOR_SPACE in_color_space; /* colorspace of input image */ 292 293 double input_gamma; /* image gamma of input image */ 294 295 /* Compression parameters --- these fields must be set before calling 296 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to 297 * initialize everything to reasonable defaults, then changing anything 298 * the application specifically wants to change. That way you won't get 299 * burnt when new parameters are added. Also note that there are several 300 * helper routines to simplify changing parameters. 301 */ 302 303 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 304 305 JDIMENSION jpeg_width; /* scaled JPEG image width */ 306 JDIMENSION jpeg_height; /* scaled JPEG image height */ 307 /* Dimensions of actual JPEG image that will be written to file, 308 * derived from input dimensions by scaling factors above. 309 * These fields are computed by jpeg_start_compress(). 310 * You can also use jpeg_calc_jpeg_dimensions() to determine these values 311 * in advance of calling jpeg_start_compress(). 312 */ 313 314 int data_precision; /* bits of precision in image data */ 315 316 int num_components; /* # of color components in JPEG image */ 317 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 318 319 jpeg_component_info * comp_info; 320 /* comp_info[i] describes component that appears i'th in SOF */ 321 322 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 323 int q_scale_factor[NUM_QUANT_TBLS]; 324 /* ptrs to coefficient quantization tables, or NULL if not defined, 325 * and corresponding scale factors (percentage, initialized 100). 326 */ 327 328 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 329 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 330 /* ptrs to Huffman coding tables, or NULL if not defined */ 331 332 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 333 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 334 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 335 336 int num_scans; /* # of entries in scan_info array */ 337 const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */ 338 /* The default value of scan_info is NULL, which causes a single-scan 339 * sequential JPEG file to be emitted. To create a multi-scan file, 340 * set num_scans and scan_info to point to an array of scan definitions. 341 */ 342 343 boolean raw_data_in; /* TRUE=caller supplies downsampled data */ 344 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 345 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */ 346 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 347 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */ 348 int smoothing_factor; /* 1..100, or 0 for no input smoothing */ 349 J_DCT_METHOD dct_method; /* DCT algorithm selector */ 350 351 /* The restart interval can be specified in absolute MCUs by setting 352 * restart_interval, or in MCU rows by setting restart_in_rows 353 * (in which case the correct restart_interval will be figured 354 * for each scan). 355 */ 356 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */ 357 int restart_in_rows; /* if > 0, MCU rows per restart interval */ 358 359 /* Parameters controlling emission of special markers. */ 360 361 boolean write_JFIF_header; /* should a JFIF marker be written? */ 362 UINT8 JFIF_major_version; /* What to write for the JFIF version number */ 363 UINT8 JFIF_minor_version; 364 /* These three values are not used by the JPEG code, merely copied */ 365 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */ 366 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */ 367 /* ratio is defined by X_density/Y_density even when density_unit=0. */ 368 UINT8 density_unit; /* JFIF code for pixel size units */ 369 UINT16 X_density; /* Horizontal pixel density */ 370 UINT16 Y_density; /* Vertical pixel density */ 371 boolean write_Adobe_marker; /* should an Adobe marker be written? */ 372 373 /* State variable: index of next scanline to be written to 374 * jpeg_write_scanlines(). Application may use this to control its 375 * processing loop, e.g., "while (next_scanline < image_height)". 376 */ 377 378 JDIMENSION next_scanline; /* 0 .. image_height-1 */ 379 380 /* Remaining fields are known throughout compressor, but generally 381 * should not be touched by a surrounding application. 382 */ 383 384 /* 385 * These fields are computed during compression startup 386 */ 387 boolean progressive_mode; /* TRUE if scan script uses progressive mode */ 388 int max_h_samp_factor; /* largest h_samp_factor */ 389 int max_v_samp_factor; /* largest v_samp_factor */ 390 391 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 392 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 393 394 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */ 395 /* The coefficient controller receives data in units of MCU rows as defined 396 * for fully interleaved scans (whether the JPEG file is interleaved or not). 397 * There are v_samp_factor * DCTSIZE sample rows of each component in an 398 * "iMCU" (interleaved MCU) row. 399 */ 400 401 /* 402 * These fields are valid during any one scan. 403 * They describe the components and MCUs actually appearing in the scan. 404 */ 405 int comps_in_scan; /* # of JPEG components in this scan */ 406 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 407 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 408 409 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 410 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 411 412 int blocks_in_MCU; /* # of DCT blocks per MCU */ 413 int MCU_membership[C_MAX_BLOCKS_IN_MCU]; 414 /* MCU_membership[i] is index in cur_comp_info of component owning */ 415 /* i'th block in an MCU */ 416 417 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 418 419 int block_size; /* the basic DCT block size: 1..16 */ 420 const int * natural_order; /* natural-order position array */ 421 int lim_Se; /* min( Se, DCTSIZE2-1 ) */ 422 423 /* 424 * Links to compression subobjects (methods and private variables of modules) 425 */ 426 struct jpeg_comp_master * master; 427 struct jpeg_c_main_controller * main; 428 struct jpeg_c_prep_controller * prep; 429 struct jpeg_c_coef_controller * coef; 430 struct jpeg_marker_writer * marker; 431 struct jpeg_color_converter * cconvert; 432 struct jpeg_downsampler * downsample; 433 struct jpeg_forward_dct * fdct; 434 struct jpeg_entropy_encoder * entropy; 435 jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */ 436 int script_space_size; 437 }; 438 439 440 /* Master record for a decompression instance */ 441 442 struct jpeg_decompress_struct { 443 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */ 444 445 /* Source of compressed data */ 446 struct jpeg_source_mgr * src; 447 448 /* Basic description of image --- filled in by jpeg_read_header(). */ 449 /* Application may inspect these values to decide how to process image. */ 450 451 JDIMENSION image_width; /* nominal image width (from SOF marker) */ 452 JDIMENSION image_height; /* nominal image height */ 453 int num_components; /* # of color components in JPEG image */ 454 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 455 456 /* Decompression processing parameters --- these fields must be set before 457 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes 458 * them to default values. 459 */ 460 461 J_COLOR_SPACE out_color_space; /* colorspace for output */ 462 463 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 464 465 double output_gamma; /* image gamma wanted in output */ 466 467 boolean buffered_image; /* TRUE=multiple output passes */ 468 boolean raw_data_out; /* TRUE=downsampled data wanted */ 469 470 J_DCT_METHOD dct_method; /* IDCT algorithm selector */ 471 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */ 472 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */ 473 474 boolean quantize_colors; /* TRUE=colormapped output wanted */ 475 /* the following are ignored if not quantize_colors: */ 476 J_DITHER_MODE dither_mode; /* type of color dithering to use */ 477 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */ 478 int desired_number_of_colors; /* max # colors to use in created colormap */ 479 /* these are significant only in buffered-image mode: */ 480 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */ 481 boolean enable_external_quant;/* enable future use of external colormap */ 482 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */ 483 484 /* Description of actual output image that will be returned to application. 485 * These fields are computed by jpeg_start_decompress(). 486 * You can also use jpeg_calc_output_dimensions() to determine these values 487 * in advance of calling jpeg_start_decompress(). 488 */ 489 490 JDIMENSION output_width; /* scaled image width */ 491 JDIMENSION output_height; /* scaled image height */ 492 int out_color_components; /* # of color components in out_color_space */ 493 int output_components; /* # of color components returned */ 494 /* output_components is 1 (a colormap index) when quantizing colors; 495 * otherwise it equals out_color_components. 496 */ 497 int rec_outbuf_height; /* min recommended height of scanline buffer */ 498 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows 499 * high, space and time will be wasted due to unnecessary data copying. 500 * Usually rec_outbuf_height will be 1 or 2, at most 4. 501 */ 502 503 /* When quantizing colors, the output colormap is described by these fields. 504 * The application can supply a colormap by setting colormap non-NULL before 505 * calling jpeg_start_decompress; otherwise a colormap is created during 506 * jpeg_start_decompress or jpeg_start_output. 507 * The map has out_color_components rows and actual_number_of_colors columns. 508 */ 509 int actual_number_of_colors; /* number of entries in use */ 510 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */ 511 512 /* State variables: these variables indicate the progress of decompression. 513 * The application may examine these but must not modify them. 514 */ 515 516 /* Row index of next scanline to be read from jpeg_read_scanlines(). 517 * Application may use this to control its processing loop, e.g., 518 * "while (output_scanline < output_height)". 519 */ 520 JDIMENSION output_scanline; /* 0 .. output_height-1 */ 521 522 /* Current input scan number and number of iMCU rows completed in scan. 523 * These indicate the progress of the decompressor input side. 524 */ 525 int input_scan_number; /* Number of SOS markers seen so far */ 526 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */ 527 528 /* The "output scan number" is the notional scan being displayed by the 529 * output side. The decompressor will not allow output scan/row number 530 * to get ahead of input scan/row, but it can fall arbitrarily far behind. 531 */ 532 int output_scan_number; /* Nominal scan number being displayed */ 533 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */ 534 535 /* Current progression status. coef_bits[c][i] indicates the precision 536 * with which component c's DCT coefficient i (in zigzag order) is known. 537 * It is -1 when no data has yet been received, otherwise it is the point 538 * transform (shift) value for the most recent scan of the coefficient 539 * (thus, 0 at completion of the progression). 540 * This pointer is NULL when reading a non-progressive file. 541 */ 542 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */ 543 544 /* Internal JPEG parameters --- the application usually need not look at 545 * these fields. Note that the decompressor output side may not use 546 * any parameters that can change between scans. 547 */ 548 549 /* Quantization and Huffman tables are carried forward across input 550 * datastreams when processing abbreviated JPEG datastreams. 551 */ 552 553 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 554 /* ptrs to coefficient quantization tables, or NULL if not defined */ 555 556 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 557 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 558 /* ptrs to Huffman coding tables, or NULL if not defined */ 559 560 /* These parameters are never carried across datastreams, since they 561 * are given in SOF/SOS markers or defined to be reset by SOI. 562 */ 563 564 int data_precision; /* bits of precision in image data */ 565 566 jpeg_component_info * comp_info; 567 /* comp_info[i] describes component that appears i'th in SOF */ 568 569 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */ 570 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */ 571 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 572 573 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 574 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 575 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 576 577 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */ 578 579 /* These fields record data obtained from optional markers recognized by 580 * the JPEG library. 581 */ 582 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */ 583 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */ 584 UINT8 JFIF_major_version; /* JFIF version number */ 585 UINT8 JFIF_minor_version; 586 UINT8 density_unit; /* JFIF code for pixel size units */ 587 UINT16 X_density; /* Horizontal pixel density */ 588 UINT16 Y_density; /* Vertical pixel density */ 589 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */ 590 UINT8 Adobe_transform; /* Color transform code from Adobe marker */ 591 592 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 593 594 /* Aside from the specific data retained from APPn markers known to the 595 * library, the uninterpreted contents of any or all APPn and COM markers 596 * can be saved in a list for examination by the application. 597 */ 598 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */ 599 600 /* Remaining fields are known throughout decompressor, but generally 601 * should not be touched by a surrounding application. 602 */ 603 604 /* 605 * These fields are computed during decompression startup 606 */ 607 int max_h_samp_factor; /* largest h_samp_factor */ 608 int max_v_samp_factor; /* largest v_samp_factor */ 609 610 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 611 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 612 613 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */ 614 /* The coefficient controller's input and output progress is measured in 615 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows 616 * in fully interleaved JPEG scans, but are used whether the scan is 617 * interleaved or not. We define an iMCU row as v_samp_factor DCT block 618 * rows of each component. Therefore, the IDCT output contains 619 * v_samp_factor*DCT_v_scaled_size sample rows of a component per iMCU row. 620 */ 621 622 JSAMPLE * sample_range_limit; /* table for fast range-limiting */ 623 624 /* 625 * These fields are valid during any one scan. 626 * They describe the components and MCUs actually appearing in the scan. 627 * Note that the decompressor output side must not use these fields. 628 */ 629 int comps_in_scan; /* # of JPEG components in this scan */ 630 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 631 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 632 633 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 634 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 635 636 int blocks_in_MCU; /* # of DCT blocks per MCU */ 637 int MCU_membership[D_MAX_BLOCKS_IN_MCU]; 638 /* MCU_membership[i] is index in cur_comp_info of component owning */ 639 /* i'th block in an MCU */ 640 641 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 642 643 /* These fields are derived from Se of first SOS marker. 644 */ 645 int block_size; /* the basic DCT block size: 1..16 */ 646 const int * natural_order; /* natural-order position array for entropy decode */ 647 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */ 648 649 /* This field is shared between entropy decoder and marker parser. 650 * It is either zero or the code of a JPEG marker that has been 651 * read from the data source, but has not yet been processed. 652 */ 653 int unread_marker; 654 655 /* 656 * Links to decompression subobjects (methods, private variables of modules) 657 */ 658 struct jpeg_decomp_master * master; 659 struct jpeg_d_main_controller * main; 660 struct jpeg_d_coef_controller * coef; 661 struct jpeg_d_post_controller * post; 662 struct jpeg_input_controller * inputctl; 663 struct jpeg_marker_reader * marker; 664 struct jpeg_entropy_decoder * entropy; 665 struct jpeg_inverse_dct * idct; 666 struct jpeg_upsampler * upsample; 667 struct jpeg_color_deconverter * cconvert; 668 struct jpeg_color_quantizer * cquantize; 669 }; 670 671 672 /* "Object" declarations for JPEG modules that may be supplied or called 673 * directly by the surrounding application. 674 * As with all objects in the JPEG library, these structs only define the 675 * publicly visible methods and state variables of a module. Additional 676 * private fields may exist after the public ones. 677 */ 678 679 680 /* Error handler object */ 681 682 struct jpeg_error_mgr { 683 /* Error exit handler: does not return to caller */ 684 JMETHOD(void, error_exit, (j_common_ptr cinfo)); 685 /* Conditionally emit a trace or warning message */ 686 JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level)); 687 /* Routine that actually outputs a trace or error message */ 688 JMETHOD(void, output_message, (j_common_ptr cinfo)); 689 /* Format a message string for the most recent JPEG error or message */ 690 JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer)); 691 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */ 692 /* Reset error state variables at start of a new image */ 693 JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo)); 694 695 /* The message ID code and any parameters are saved here. 696 * A message can have one string parameter or up to 8 int parameters. 697 */ 698 int msg_code; 699 #define JMSG_STR_PARM_MAX 80 700 union { 701 int i[8]; 702 char s[JMSG_STR_PARM_MAX]; 703 } msg_parm; 704 705 /* Standard state variables for error facility */ 706 707 int trace_level; /* max msg_level that will be displayed */ 708 709 /* For recoverable corrupt-data errors, we emit a warning message, 710 * but keep going unless emit_message chooses to abort. emit_message 711 * should count warnings in num_warnings. The surrounding application 712 * can check for bad data by seeing if num_warnings is nonzero at the 713 * end of processing. 714 */ 715 long num_warnings; /* number of corrupt-data warnings */ 716 717 /* These fields point to the table(s) of error message strings. 718 * An application can change the table pointer to switch to a different 719 * message list (typically, to change the language in which errors are 720 * reported). Some applications may wish to add additional error codes 721 * that will be handled by the JPEG library error mechanism; the second 722 * table pointer is used for this purpose. 723 * 724 * First table includes all errors generated by JPEG library itself. 725 * Error code 0 is reserved for a "no such error string" message. 726 */ 727 const char * const * jpeg_message_table; /* Library errors */ 728 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */ 729 /* Second table can be added by application (see cjpeg/djpeg for example). 730 * It contains strings numbered first_addon_message..last_addon_message. 731 */ 732 const char * const * addon_message_table; /* Non-library errors */ 733 int first_addon_message; /* code for first string in addon table */ 734 int last_addon_message; /* code for last string in addon table */ 735 }; 736 737 738 /* Progress monitor object */ 739 740 struct jpeg_progress_mgr { 741 JMETHOD(void, progress_monitor, (j_common_ptr cinfo)); 742 743 long pass_counter; /* work units completed in this pass */ 744 long pass_limit; /* total number of work units in this pass */ 745 int completed_passes; /* passes completed so far */ 746 int total_passes; /* total number of passes expected */ 747 }; 748 749 750 /* Data destination object for compression */ 751 752 struct jpeg_destination_mgr { 753 JOCTET * next_output_byte; /* => next byte to write in buffer */ 754 size_t free_in_buffer; /* # of byte spaces remaining in buffer */ 755 756 JMETHOD(void, init_destination, (j_compress_ptr cinfo)); 757 JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo)); 758 JMETHOD(void, term_destination, (j_compress_ptr cinfo)); 759 }; 760 761 762 /* Data source object for decompression */ 763 764 struct jpeg_source_mgr { 765 const JOCTET * next_input_byte; /* => next byte to read from buffer */ 766 size_t bytes_in_buffer; /* # of bytes remaining in buffer */ 767 768 JMETHOD(void, init_source, (j_decompress_ptr cinfo)); 769 JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo)); 770 JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes)); 771 JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired)); 772 JMETHOD(void, term_source, (j_decompress_ptr cinfo)); 773 }; 774 775 776 /* Memory manager object. 777 * Allocates "small" objects (a few K total), "large" objects (tens of K), 778 * and "really big" objects (virtual arrays with backing store if needed). 779 * The memory manager does not allow individual objects to be freed; rather, 780 * each created object is assigned to a pool, and whole pools can be freed 781 * at once. This is faster and more convenient than remembering exactly what 782 * to free, especially where malloc()/free() are not too speedy. 783 * NB: alloc routines never return NULL. They exit to error_exit if not 784 * successful. 785 */ 786 787 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */ 788 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */ 789 #define JPOOL_NUMPOOLS 2 790 791 typedef struct jvirt_sarray_control * jvirt_sarray_ptr; 792 typedef struct jvirt_barray_control * jvirt_barray_ptr; 793 794 795 struct jpeg_memory_mgr { 796 /* Method pointers */ 797 JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id, 798 size_t sizeofobject)); 799 JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id, 800 size_t sizeofobject)); 801 JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id, 802 JDIMENSION samplesperrow, 803 JDIMENSION numrows)); 804 JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id, 805 JDIMENSION blocksperrow, 806 JDIMENSION numrows)); 807 JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo, 808 int pool_id, 809 boolean pre_zero, 810 JDIMENSION samplesperrow, 811 JDIMENSION numrows, 812 JDIMENSION maxaccess)); 813 JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo, 814 int pool_id, 815 boolean pre_zero, 816 JDIMENSION blocksperrow, 817 JDIMENSION numrows, 818 JDIMENSION maxaccess)); 819 JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo)); 820 JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo, 821 jvirt_sarray_ptr ptr, 822 JDIMENSION start_row, 823 JDIMENSION num_rows, 824 boolean writable)); 825 JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo, 826 jvirt_barray_ptr ptr, 827 JDIMENSION start_row, 828 JDIMENSION num_rows, 829 boolean writable)); 830 JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id)); 831 JMETHOD(void, self_destruct, (j_common_ptr cinfo)); 832 833 /* Limit on memory allocation for this JPEG object. (Note that this is 834 * merely advisory, not a guaranteed maximum; it only affects the space 835 * used for virtual-array buffers.) May be changed by outer application 836 * after creating the JPEG object. 837 */ 838 long max_memory_to_use; 839 840 /* Maximum allocation request accepted by alloc_large. */ 841 long max_alloc_chunk; 842 }; 843 844 845 /* Routine signature for application-supplied marker processing methods. 846 * Need not pass marker code since it is stored in cinfo->unread_marker. 847 */ 848 typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo)); 849 850 851 /* Declarations for routines called by application. 852 * The JPP macro hides prototype parameters from compilers that can't cope. 853 * Note JPP requires double parentheses. 854 */ 855 856 #ifdef HAVE_PROTOTYPES 857 #define JPP(arglist) arglist 858 #else 859 #define JPP(arglist) () 860 #endif 861 862 863 /* Short forms of external names for systems with brain-damaged linkers. 864 * We shorten external names to be unique in the first six letters, which 865 * is good enough for all known systems. 866 * (If your compiler itself needs names to be unique in less than 15 867 * characters, you are out of luck. Get a better compiler.) 868 */ 869 870 #ifdef NEED_SHORT_EXTERNAL_NAMES 871 #define jpeg_std_error jStdError 872 #define jpeg_CreateCompress jCreaCompress 873 #define jpeg_CreateDecompress jCreaDecompress 874 #define jpeg_destroy_compress jDestCompress 875 #define jpeg_destroy_decompress jDestDecompress 876 #define jpeg_stdio_dest jStdDest 877 #define jpeg_stdio_src jStdSrc 878 #define jpeg_mem_dest jMemDest 879 #define jpeg_mem_src jMemSrc 880 #define jpeg_set_defaults jSetDefaults 881 #define jpeg_set_colorspace jSetColorspace 882 #define jpeg_default_colorspace jDefColorspace 883 #define jpeg_set_quality jSetQuality 884 #define jpeg_set_linear_quality jSetLQuality 885 #define jpeg_default_qtables jDefQTables 886 #define jpeg_add_quant_table jAddQuantTable 887 #define jpeg_quality_scaling jQualityScaling 888 #define jpeg_simple_progression jSimProgress 889 #define jpeg_suppress_tables jSuppressTables 890 #define jpeg_alloc_quant_table jAlcQTable 891 #define jpeg_alloc_huff_table jAlcHTable 892 #define jpeg_start_compress jStrtCompress 893 #define jpeg_write_scanlines jWrtScanlines 894 #define jpeg_finish_compress jFinCompress 895 #define jpeg_calc_jpeg_dimensions jCjpegDimensions 896 #define jpeg_write_raw_data jWrtRawData 897 #define jpeg_write_marker jWrtMarker 898 #define jpeg_write_m_header jWrtMHeader 899 #define jpeg_write_m_byte jWrtMByte 900 #define jpeg_write_tables jWrtTables 901 #define jpeg_read_header jReadHeader 902 #define jpeg_start_decompress jStrtDecompress 903 #define jpeg_read_scanlines jReadScanlines 904 #define jpeg_finish_decompress jFinDecompress 905 #define jpeg_read_raw_data jReadRawData 906 #define jpeg_has_multiple_scans jHasMultScn 907 #define jpeg_start_output jStrtOutput 908 #define jpeg_finish_output jFinOutput 909 #define jpeg_input_complete jInComplete 910 #define jpeg_new_colormap jNewCMap 911 #define jpeg_consume_input jConsumeInput 912 #define jpeg_core_output_dimensions jCoreDimensions 913 #define jpeg_calc_output_dimensions jCalcDimensions 914 #define jpeg_save_markers jSaveMarkers 915 #define jpeg_set_marker_processor jSetMarker 916 #define jpeg_read_coefficients jReadCoefs 917 #define jpeg_write_coefficients jWrtCoefs 918 #define jpeg_copy_critical_parameters jCopyCrit 919 #define jpeg_abort_compress jAbrtCompress 920 #define jpeg_abort_decompress jAbrtDecompress 921 #define jpeg_abort jAbort 922 #define jpeg_destroy jDestroy 923 #define jpeg_resync_to_restart jResyncRestart 924 #endif /* NEED_SHORT_EXTERNAL_NAMES */ 925 926 927 /* Default error-management setup */ 928 EXTERN(struct jpeg_error_mgr *) jpeg_std_error 929 JPP((struct jpeg_error_mgr * err)); 930 931 /* Initialization of JPEG compression objects. 932 * jpeg_create_compress() and jpeg_create_decompress() are the exported 933 * names that applications should call. These expand to calls on 934 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information 935 * passed for version mismatch checking. 936 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx. 937 */ 938 #define jpeg_create_compress(cinfo) \ 939 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \ 940 (size_t) sizeof(struct jpeg_compress_struct)) 941 #define jpeg_create_decompress(cinfo) \ 942 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \ 943 (size_t) sizeof(struct jpeg_decompress_struct)) 944 EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo, 945 int version, size_t structsize)); 946 EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo, 947 int version, size_t structsize)); 948 /* Destruction of JPEG compression objects */ 949 EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo)); 950 EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo)); 951 952 /* Standard data source and destination managers: stdio streams. */ 953 /* Caller is responsible for opening the file before and closing after. */ 954 EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile)); 955 EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile)); 956 957 /* Data source and destination managers: memory buffers. */ 958 EXTERN(void) jpeg_mem_dest JPP((j_compress_ptr cinfo, 959 unsigned char ** outbuffer, 960 unsigned long * outsize)); 961 EXTERN(void) jpeg_mem_src JPP((j_decompress_ptr cinfo, 962 unsigned char * inbuffer, 963 unsigned long insize)); 964 965 /* Default parameter setup for compression */ 966 EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo)); 967 /* Compression parameter setup aids */ 968 EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo, 969 J_COLOR_SPACE colorspace)); 970 EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo)); 971 EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality, 972 boolean force_baseline)); 973 EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo, 974 int scale_factor, 975 boolean force_baseline)); 976 EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo, 977 boolean force_baseline)); 978 EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl, 979 const unsigned int *basic_table, 980 int scale_factor, 981 boolean force_baseline)); 982 EXTERN(int) jpeg_quality_scaling JPP((int quality)); 983 EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo)); 984 EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo, 985 boolean suppress)); 986 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo)); 987 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo)); 988 989 /* Main entry points for compression */ 990 EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo, 991 boolean write_all_tables)); 992 EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo, 993 JSAMPARRAY scanlines, 994 JDIMENSION num_lines)); 995 EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo)); 996 997 /* Precalculate JPEG dimensions for current compression parameters. */ 998 EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo)); 999 1000 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */ 1001 EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo, 1002 JSAMPIMAGE data, 1003 JDIMENSION num_lines)); 1004 1005 /* Write a special marker. See libjpeg.txt concerning safe usage. */ 1006 EXTERN(void) jpeg_write_marker 1007 JPP((j_compress_ptr cinfo, int marker, 1008 const JOCTET * dataptr, unsigned int datalen)); 1009 /* Same, but piecemeal. */ 1010 EXTERN(void) jpeg_write_m_header 1011 JPP((j_compress_ptr cinfo, int marker, unsigned int datalen)); 1012 EXTERN(void) jpeg_write_m_byte 1013 JPP((j_compress_ptr cinfo, int val)); 1014 1015 /* Alternate compression function: just write an abbreviated table file */ 1016 EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo)); 1017 1018 /* Decompression startup: read start of JPEG datastream to see what's there */ 1019 EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo, 1020 boolean require_image)); 1021 /* Return value is one of: */ 1022 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */ 1023 #define JPEG_HEADER_OK 1 /* Found valid image datastream */ 1024 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */ 1025 /* If you pass require_image = TRUE (normal case), you need not check for 1026 * a TABLES_ONLY return code; an abbreviated file will cause an error exit. 1027 * JPEG_SUSPENDED is only possible if you use a data source module that can 1028 * give a suspension return (the stdio source module doesn't). 1029 */ 1030 1031 /* Main entry points for decompression */ 1032 EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo)); 1033 EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo, 1034 JSAMPARRAY scanlines, 1035 JDIMENSION max_lines)); 1036 EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo)); 1037 1038 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */ 1039 EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo, 1040 JSAMPIMAGE data, 1041 JDIMENSION max_lines)); 1042 1043 /* Additional entry points for buffered-image mode. */ 1044 EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo)); 1045 EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo, 1046 int scan_number)); 1047 EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo)); 1048 EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo)); 1049 EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo)); 1050 EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo)); 1051 /* Return value is one of: */ 1052 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */ 1053 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */ 1054 #define JPEG_REACHED_EOI 2 /* Reached end of image */ 1055 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */ 1056 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */ 1057 1058 /* Precalculate output dimensions for current decompression parameters. */ 1059 EXTERN(void) jpeg_core_output_dimensions JPP((j_decompress_ptr cinfo)); 1060 EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo)); 1061 1062 /* Control saving of COM and APPn markers into marker_list. */ 1063 EXTERN(void) jpeg_save_markers 1064 JPP((j_decompress_ptr cinfo, int marker_code, 1065 unsigned int length_limit)); 1066 1067 /* Install a special processing method for COM or APPn markers. */ 1068 EXTERN(void) jpeg_set_marker_processor 1069 JPP((j_decompress_ptr cinfo, int marker_code, 1070 jpeg_marker_parser_method routine)); 1071 1072 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */ 1073 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo)); 1074 EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo, 1075 jvirt_barray_ptr * coef_arrays)); 1076 EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo, 1077 j_compress_ptr dstinfo)); 1078 1079 /* If you choose to abort compression or decompression before completing 1080 * jpeg_finish_(de)compress, then you need to clean up to release memory, 1081 * temporary files, etc. You can just call jpeg_destroy_(de)compress 1082 * if you're done with the JPEG object, but if you want to clean it up and 1083 * reuse it, call this: 1084 */ 1085 EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo)); 1086 EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo)); 1087 1088 /* Generic versions of jpeg_abort and jpeg_destroy that work on either 1089 * flavor of JPEG object. These may be more convenient in some places. 1090 */ 1091 EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo)); 1092 EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo)); 1093 1094 /* Default restart-marker-resync procedure for use by data source modules */ 1095 EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo, 1096 int desired)); 1097 1098 1099 /* These marker codes are exported since applications and data source modules 1100 * are likely to want to use them. 1101 */ 1102 1103 #define JPEG_RST0 0xD0 /* RST0 marker code */ 1104 #define JPEG_EOI 0xD9 /* EOI marker code */ 1105 #define JPEG_APP0 0xE0 /* APP0 marker code */ 1106 #define JPEG_COM 0xFE /* COM marker code */ 1107 1108 1109 /* If we have a brain-damaged compiler that emits warnings (or worse, errors) 1110 * for structure definitions that are never filled in, keep it quiet by 1111 * supplying dummy definitions for the various substructures. 1112 */ 1113 1114 #ifdef INCOMPLETE_TYPES_BROKEN 1115 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */ 1116 struct jvirt_sarray_control { long dummy; }; 1117 struct jvirt_barray_control { long dummy; }; 1118 struct jpeg_comp_master { long dummy; }; 1119 struct jpeg_c_main_controller { long dummy; }; 1120 struct jpeg_c_prep_controller { long dummy; }; 1121 struct jpeg_c_coef_controller { long dummy; }; 1122 struct jpeg_marker_writer { long dummy; }; 1123 struct jpeg_color_converter { long dummy; }; 1124 struct jpeg_downsampler { long dummy; }; 1125 struct jpeg_forward_dct { long dummy; }; 1126 struct jpeg_entropy_encoder { long dummy; }; 1127 struct jpeg_decomp_master { long dummy; }; 1128 struct jpeg_d_main_controller { long dummy; }; 1129 struct jpeg_d_coef_controller { long dummy; }; 1130 struct jpeg_d_post_controller { long dummy; }; 1131 struct jpeg_input_controller { long dummy; }; 1132 struct jpeg_marker_reader { long dummy; }; 1133 struct jpeg_entropy_decoder { long dummy; }; 1134 struct jpeg_inverse_dct { long dummy; }; 1135 struct jpeg_upsampler { long dummy; }; 1136 struct jpeg_color_deconverter { long dummy; }; 1137 struct jpeg_color_quantizer { long dummy; }; 1138 #endif /* JPEG_INTERNALS */ 1139 #endif /* INCOMPLETE_TYPES_BROKEN */ 1140 1141 1142 /* 1143 * The JPEG library modules define JPEG_INTERNALS before including this file. 1144 * The internal structure declarations are read only when that is true. 1145 * Applications using the library should not include jpegint.h, but may wish 1146 * to include jerror.h. 1147 */ 1148 1149 #ifdef JPEG_INTERNALS 1150 #include "jpegint.h" /* fetch private declarations */ 1151 #include "jerror.h" /* fetch error codes too */ 1152 #endif 1153 1154 #ifdef __cplusplus 1155 #ifndef DONT_USE_EXTERN_C 1156 } 1157 #endif 1158 #endif 1159 1160 #endif /* JPEGLIB_H */ 1161