1 /* 2 * jpeglib.h 3 * 4 * Copyright (C) 1991-1998, Thomas G. Lane. 5 * Modified 2002-2009 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 ID for the JPEG library. 37 * Might be useful for tests like "#if JPEG_LIB_VERSION >= 80". 38 */ 39 40 #define JPEG_LIB_VERSION 80 /* Version 8.0 */ 41 42 43 /* Various constants determining the sizes of things. 44 * All of these are specified by the JPEG standard, so don't change them 45 * if you want to be compatible. 46 */ 47 48 #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */ 49 #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */ 50 #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */ 51 #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */ 52 #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */ 53 #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */ 54 #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */ 55 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard; 56 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU. 57 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU 58 * to handle it. We even let you do this from the jconfig.h file. However, 59 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe 60 * sometimes emits noncompliant files doesn't mean you should too. 61 */ 62 #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */ 63 #ifndef D_MAX_BLOCKS_IN_MCU 64 #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */ 65 #endif 66 67 68 /* Data structures for images (arrays of samples and of DCT coefficients). 69 * On 80x86 machines, the image arrays are too big for near pointers, 70 * but the pointer arrays can fit in near memory. 71 */ 72 73 typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */ 74 typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */ 75 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */ 76 77 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */ 78 typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */ 79 typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */ 80 typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */ 81 82 typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */ 83 84 85 /* Types for JPEG compression parameters and working tables. */ 86 87 88 /* DCT coefficient quantization tables. */ 89 90 typedef struct { 91 /* This array gives the coefficient quantizers in natural array order 92 * (not the zigzag order in which they are stored in a JPEG DQT marker). 93 * CAUTION: IJG versions prior to v6a kept this array in zigzag order. 94 */ 95 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */ 96 /* This field is used only during compression. It's initialized FALSE when 97 * the table is created, and set TRUE when it's been output to the file. 98 * You could suppress output of a table by setting this to TRUE. 99 * (See jpeg_suppress_tables for an example.) 100 */ 101 boolean sent_table; /* TRUE when table has been output */ 102 } JQUANT_TBL; 103 104 105 /* Huffman coding tables. */ 106 107 typedef struct { 108 /* These two fields directly represent the contents of a JPEG DHT marker */ 109 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */ 110 /* length k bits; bits[0] is unused */ 111 UINT8 huffval[256]; /* The symbols, in order of incr code length */ 112 /* This field is used only during compression. It's initialized FALSE when 113 * the table is created, and set TRUE when it's been output to the file. 114 * You could suppress output of a table by setting this to TRUE. 115 * (See jpeg_suppress_tables for an example.) 116 */ 117 boolean sent_table; /* TRUE when table has been output */ 118 } JHUFF_TBL; 119 120 121 /* Basic info about one component (color channel). */ 122 123 typedef struct { 124 /* These values are fixed over the whole image. */ 125 /* For compression, they must be supplied by parameter setup; */ 126 /* for decompression, they are read from the SOF marker. */ 127 int component_id; /* identifier for this component (0..255) */ 128 int component_index; /* its index in SOF or cinfo->comp_info[] */ 129 int h_samp_factor; /* horizontal sampling factor (1..4) */ 130 int v_samp_factor; /* vertical sampling factor (1..4) */ 131 int quant_tbl_no; /* quantization table selector (0..3) */ 132 /* These values may vary between scans. */ 133 /* For compression, they must be supplied by parameter setup; */ 134 /* for decompression, they are read from the SOS marker. */ 135 /* The decompressor output side may not use these variables. */ 136 int dc_tbl_no; /* DC entropy table selector (0..3) */ 137 int ac_tbl_no; /* AC entropy table selector (0..3) */ 138 139 /* Remaining fields should be treated as private by applications. */ 140 141 /* These values are computed during compression or decompression startup: */ 142 /* Component's size in DCT blocks. 143 * Any dummy blocks added to complete an MCU are not counted; therefore 144 * these values do not depend on whether a scan is interleaved or not. 145 */ 146 JDIMENSION width_in_blocks; 147 JDIMENSION height_in_blocks; 148 /* Size of a DCT block in samples, 149 * reflecting any scaling we choose to apply during the DCT step. 150 * Values from 1 to 16 are supported. 151 * Note that different components may receive different DCT scalings. 152 */ 153 int DCT_h_scaled_size; 154 int DCT_v_scaled_size; 155 /* The downsampled dimensions are the component's actual, unpadded number 156 * of samples at the main buffer (preprocessing/compression interface); 157 * DCT scaling is included, so 158 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_h_scaled_size/DCTSIZE) 159 * and similarly for height. 160 */ 161 JDIMENSION downsampled_width; /* actual width in samples */ 162 JDIMENSION downsampled_height; /* actual height in samples */ 163 /* This flag is used only for decompression. In cases where some of the 164 * components will be ignored (eg grayscale output from YCbCr image), 165 * we can skip most computations for the unused components. 166 */ 167 boolean component_needed; /* do we need the value of this component? */ 168 169 /* These values are computed before starting a scan of the component. */ 170 /* The decompressor output side may not use these variables. */ 171 int MCU_width; /* number of blocks per MCU, horizontally */ 172 int MCU_height; /* number of blocks per MCU, vertically */ 173 int MCU_blocks; /* MCU_width * MCU_height */ 174 int MCU_sample_width; /* MCU width in samples: MCU_width * DCT_h_scaled_size */ 175 int last_col_width; /* # of non-dummy blocks across in last MCU */ 176 int last_row_height; /* # of non-dummy blocks down in last MCU */ 177 178 /* Saved quantization table for component; NULL if none yet saved. 179 * See jdinput.c comments about the need for this information. 180 * This field is currently used only for decompression. 181 */ 182 JQUANT_TBL * quant_table; 183 184 /* Private per-component storage for DCT or IDCT subsystem. */ 185 void * dct_table; 186 } jpeg_component_info; 187 188 189 /* The script for encoding a multiple-scan file is an array of these: */ 190 191 typedef struct { 192 int comps_in_scan; /* number of components encoded in this scan */ 193 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */ 194 int Ss, Se; /* progressive JPEG spectral selection parms */ 195 int Ah, Al; /* progressive JPEG successive approx. parms */ 196 } jpeg_scan_info; 197 198 /* The decompressor can save APPn and COM markers in a list of these: */ 199 200 typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr; 201 202 struct jpeg_marker_struct { 203 jpeg_saved_marker_ptr next; /* next in list, or NULL */ 204 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */ 205 unsigned int original_length; /* # bytes of data in the file */ 206 unsigned int data_length; /* # bytes of data saved at data[] */ 207 JOCTET FAR * data; /* the data contained in the marker */ 208 /* the marker length word is not counted in data_length or original_length */ 209 }; 210 211 /* Known color spaces. */ 212 213 typedef enum { 214 JCS_UNKNOWN, /* error/unspecified */ 215 JCS_GRAYSCALE, /* monochrome */ 216 JCS_RGB, /* red/green/blue */ 217 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */ 218 JCS_CMYK, /* C/M/Y/K */ 219 JCS_YCCK /* Y/Cb/Cr/K */ 220 } J_COLOR_SPACE; 221 222 /* DCT/IDCT algorithm options. */ 223 224 typedef enum { 225 JDCT_ISLOW, /* slow but accurate integer algorithm */ 226 JDCT_IFAST, /* faster, less accurate integer method */ 227 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */ 228 } J_DCT_METHOD; 229 230 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */ 231 #define JDCT_DEFAULT JDCT_ISLOW 232 #endif 233 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */ 234 #define JDCT_FASTEST JDCT_IFAST 235 #endif 236 237 /* Dithering options for decompression. */ 238 239 typedef enum { 240 JDITHER_NONE, /* no dithering */ 241 JDITHER_ORDERED, /* simple ordered dither */ 242 JDITHER_FS /* Floyd-Steinberg error diffusion dither */ 243 } J_DITHER_MODE; 244 245 246 /* Common fields between JPEG compression and decompression master structs. */ 247 248 #define jpeg_common_fields \ 249 struct jpeg_error_mgr * err; /* Error handler module */\ 250 struct jpeg_memory_mgr * mem; /* Memory manager module */\ 251 struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\ 252 void * client_data; /* Available for use by application */\ 253 boolean is_decompressor; /* So common code can tell which is which */\ 254 int global_state /* For checking call sequence validity */ 255 256 /* Routines that are to be used by both halves of the library are declared 257 * to receive a pointer to this structure. There are no actual instances of 258 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct. 259 */ 260 struct jpeg_common_struct { 261 jpeg_common_fields; /* Fields common to both master struct types */ 262 /* Additional fields follow in an actual jpeg_compress_struct or 263 * jpeg_decompress_struct. All three structs must agree on these 264 * initial fields! (This would be a lot cleaner in C++.) 265 */ 266 }; 267 268 typedef struct jpeg_common_struct * j_common_ptr; 269 typedef struct jpeg_compress_struct * j_compress_ptr; 270 typedef struct jpeg_decompress_struct * j_decompress_ptr; 271 272 273 /* Master record for a compression instance */ 274 275 struct jpeg_compress_struct { 276 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */ 277 278 /* Destination for compressed data */ 279 struct jpeg_destination_mgr * dest; 280 281 /* Description of source image --- these fields must be filled in by 282 * outer application before starting compression. in_color_space must 283 * be correct before you can even call jpeg_set_defaults(). 284 */ 285 286 JDIMENSION image_width; /* input image width */ 287 JDIMENSION image_height; /* input image height */ 288 int input_components; /* # of color components in input image */ 289 J_COLOR_SPACE in_color_space; /* colorspace of input image */ 290 291 double input_gamma; /* image gamma of input image */ 292 293 /* Compression parameters --- these fields must be set before calling 294 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to 295 * initialize everything to reasonable defaults, then changing anything 296 * the application specifically wants to change. That way you won't get 297 * burnt when new parameters are added. Also note that there are several 298 * helper routines to simplify changing parameters. 299 */ 300 301 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 302 303 JDIMENSION jpeg_width; /* scaled JPEG image width */ 304 JDIMENSION jpeg_height; /* scaled JPEG image height */ 305 /* Dimensions of actual JPEG image that will be written to file, 306 * derived from input dimensions by scaling factors above. 307 * These fields are computed by jpeg_start_compress(). 308 * You can also use jpeg_calc_jpeg_dimensions() to determine these values 309 * in advance of calling jpeg_start_compress(). 310 */ 311 312 int data_precision; /* bits of precision in image data */ 313 314 int num_components; /* # of color components in JPEG image */ 315 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 316 317 jpeg_component_info * comp_info; 318 /* comp_info[i] describes component that appears i'th in SOF */ 319 320 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 321 int q_scale_factor[NUM_QUANT_TBLS]; 322 /* ptrs to coefficient quantization tables, or NULL if not defined, 323 * and corresponding scale factors (percentage, initialized 100). 324 */ 325 326 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 327 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 328 /* ptrs to Huffman coding tables, or NULL if not defined */ 329 330 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 331 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 332 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 333 334 int num_scans; /* # of entries in scan_info array */ 335 const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */ 336 /* The default value of scan_info is NULL, which causes a single-scan 337 * sequential JPEG file to be emitted. To create a multi-scan file, 338 * set num_scans and scan_info to point to an array of scan definitions. 339 */ 340 341 boolean raw_data_in; /* TRUE=caller supplies downsampled data */ 342 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 343 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */ 344 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 345 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */ 346 int smoothing_factor; /* 1..100, or 0 for no input smoothing */ 347 J_DCT_METHOD dct_method; /* DCT algorithm selector */ 348 349 /* The restart interval can be specified in absolute MCUs by setting 350 * restart_interval, or in MCU rows by setting restart_in_rows 351 * (in which case the correct restart_interval will be figured 352 * for each scan). 353 */ 354 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */ 355 int restart_in_rows; /* if > 0, MCU rows per restart interval */ 356 357 /* Parameters controlling emission of special markers. */ 358 359 boolean write_JFIF_header; /* should a JFIF marker be written? */ 360 UINT8 JFIF_major_version; /* What to write for the JFIF version number */ 361 UINT8 JFIF_minor_version; 362 /* These three values are not used by the JPEG code, merely copied */ 363 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */ 364 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */ 365 /* ratio is defined by X_density/Y_density even when density_unit=0. */ 366 UINT8 density_unit; /* JFIF code for pixel size units */ 367 UINT16 X_density; /* Horizontal pixel density */ 368 UINT16 Y_density; /* Vertical pixel density */ 369 boolean write_Adobe_marker; /* should an Adobe marker be written? */ 370 371 /* State variable: index of next scanline to be written to 372 * jpeg_write_scanlines(). Application may use this to control its 373 * processing loop, e.g., "while (next_scanline < image_height)". 374 */ 375 376 JDIMENSION next_scanline; /* 0 .. image_height-1 */ 377 378 /* Remaining fields are known throughout compressor, but generally 379 * should not be touched by a surrounding application. 380 */ 381 382 /* 383 * These fields are computed during compression startup 384 */ 385 boolean progressive_mode; /* TRUE if scan script uses progressive mode */ 386 int max_h_samp_factor; /* largest h_samp_factor */ 387 int max_v_samp_factor; /* largest v_samp_factor */ 388 389 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 390 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 391 392 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */ 393 /* The coefficient controller receives data in units of MCU rows as defined 394 * for fully interleaved scans (whether the JPEG file is interleaved or not). 395 * There are v_samp_factor * DCTSIZE sample rows of each component in an 396 * "iMCU" (interleaved MCU) row. 397 */ 398 399 /* 400 * These fields are valid during any one scan. 401 * They describe the components and MCUs actually appearing in the scan. 402 */ 403 int comps_in_scan; /* # of JPEG components in this scan */ 404 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 405 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 406 407 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 408 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 409 410 int blocks_in_MCU; /* # of DCT blocks per MCU */ 411 int MCU_membership[C_MAX_BLOCKS_IN_MCU]; 412 /* MCU_membership[i] is index in cur_comp_info of component owning */ 413 /* i'th block in an MCU */ 414 415 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 416 417 int block_size; /* the basic DCT block size: 1..16 */ 418 const int * natural_order; /* natural-order position array */ 419 int lim_Se; /* min( Se, DCTSIZE2-1 ) */ 420 421 /* 422 * Links to compression subobjects (methods and private variables of modules) 423 */ 424 struct jpeg_comp_master * master; 425 struct jpeg_c_main_controller * main; 426 struct jpeg_c_prep_controller * prep; 427 struct jpeg_c_coef_controller * coef; 428 struct jpeg_marker_writer * marker; 429 struct jpeg_color_converter * cconvert; 430 struct jpeg_downsampler * downsample; 431 struct jpeg_forward_dct * fdct; 432 struct jpeg_entropy_encoder * entropy; 433 jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */ 434 int script_space_size; 435 }; 436 437 438 /* Master record for a decompression instance */ 439 440 struct jpeg_decompress_struct { 441 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */ 442 443 /* Source of compressed data */ 444 struct jpeg_source_mgr * src; 445 446 /* Basic description of image --- filled in by jpeg_read_header(). */ 447 /* Application may inspect these values to decide how to process image. */ 448 449 JDIMENSION image_width; /* nominal image width (from SOF marker) */ 450 JDIMENSION image_height; /* nominal image height */ 451 int num_components; /* # of color components in JPEG image */ 452 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 453 454 /* Decompression processing parameters --- these fields must be set before 455 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes 456 * them to default values. 457 */ 458 459 J_COLOR_SPACE out_color_space; /* colorspace for output */ 460 461 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 462 463 double output_gamma; /* image gamma wanted in output */ 464 465 boolean buffered_image; /* TRUE=multiple output passes */ 466 boolean raw_data_out; /* TRUE=downsampled data wanted */ 467 468 J_DCT_METHOD dct_method; /* IDCT algorithm selector */ 469 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */ 470 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */ 471 472 boolean quantize_colors; /* TRUE=colormapped output wanted */ 473 /* the following are ignored if not quantize_colors: */ 474 J_DITHER_MODE dither_mode; /* type of color dithering to use */ 475 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */ 476 int desired_number_of_colors; /* max # colors to use in created colormap */ 477 /* these are significant only in buffered-image mode: */ 478 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */ 479 boolean enable_external_quant;/* enable future use of external colormap */ 480 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */ 481 482 /* Description of actual output image that will be returned to application. 483 * These fields are computed by jpeg_start_decompress(). 484 * You can also use jpeg_calc_output_dimensions() to determine these values 485 * in advance of calling jpeg_start_decompress(). 486 */ 487 488 JDIMENSION output_width; /* scaled image width */ 489 JDIMENSION output_height; /* scaled image height */ 490 int out_color_components; /* # of color components in out_color_space */ 491 int output_components; /* # of color components returned */ 492 /* output_components is 1 (a colormap index) when quantizing colors; 493 * otherwise it equals out_color_components. 494 */ 495 int rec_outbuf_height; /* min recommended height of scanline buffer */ 496 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows 497 * high, space and time will be wasted due to unnecessary data copying. 498 * Usually rec_outbuf_height will be 1 or 2, at most 4. 499 */ 500 501 /* When quantizing colors, the output colormap is described by these fields. 502 * The application can supply a colormap by setting colormap non-NULL before 503 * calling jpeg_start_decompress; otherwise a colormap is created during 504 * jpeg_start_decompress or jpeg_start_output. 505 * The map has out_color_components rows and actual_number_of_colors columns. 506 */ 507 int actual_number_of_colors; /* number of entries in use */ 508 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */ 509 510 /* State variables: these variables indicate the progress of decompression. 511 * The application may examine these but must not modify them. 512 */ 513 514 /* Row index of next scanline to be read from jpeg_read_scanlines(). 515 * Application may use this to control its processing loop, e.g., 516 * "while (output_scanline < output_height)". 517 */ 518 JDIMENSION output_scanline; /* 0 .. output_height-1 */ 519 520 /* Current input scan number and number of iMCU rows completed in scan. 521 * These indicate the progress of the decompressor input side. 522 */ 523 int input_scan_number; /* Number of SOS markers seen so far */ 524 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */ 525 526 /* The "output scan number" is the notional scan being displayed by the 527 * output side. The decompressor will not allow output scan/row number 528 * to get ahead of input scan/row, but it can fall arbitrarily far behind. 529 */ 530 int output_scan_number; /* Nominal scan number being displayed */ 531 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */ 532 533 /* Current progression status. coef_bits[c][i] indicates the precision 534 * with which component c's DCT coefficient i (in zigzag order) is known. 535 * It is -1 when no data has yet been received, otherwise it is the point 536 * transform (shift) value for the most recent scan of the coefficient 537 * (thus, 0 at completion of the progression). 538 * This pointer is NULL when reading a non-progressive file. 539 */ 540 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */ 541 542 /* Internal JPEG parameters --- the application usually need not look at 543 * these fields. Note that the decompressor output side may not use 544 * any parameters that can change between scans. 545 */ 546 547 /* Quantization and Huffman tables are carried forward across input 548 * datastreams when processing abbreviated JPEG datastreams. 549 */ 550 551 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 552 /* ptrs to coefficient quantization tables, or NULL if not defined */ 553 554 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 555 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 556 /* ptrs to Huffman coding tables, or NULL if not defined */ 557 558 /* These parameters are never carried across datastreams, since they 559 * are given in SOF/SOS markers or defined to be reset by SOI. 560 */ 561 562 int data_precision; /* bits of precision in image data */ 563 564 jpeg_component_info * comp_info; 565 /* comp_info[i] describes component that appears i'th in SOF */ 566 567 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */ 568 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */ 569 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 570 571 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 572 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 573 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 574 575 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */ 576 577 /* These fields record data obtained from optional markers recognized by 578 * the JPEG library. 579 */ 580 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */ 581 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */ 582 UINT8 JFIF_major_version; /* JFIF version number */ 583 UINT8 JFIF_minor_version; 584 UINT8 density_unit; /* JFIF code for pixel size units */ 585 UINT16 X_density; /* Horizontal pixel density */ 586 UINT16 Y_density; /* Vertical pixel density */ 587 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */ 588 UINT8 Adobe_transform; /* Color transform code from Adobe marker */ 589 590 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 591 592 /* Aside from the specific data retained from APPn markers known to the 593 * library, the uninterpreted contents of any or all APPn and COM markers 594 * can be saved in a list for examination by the application. 595 */ 596 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */ 597 598 /* Remaining fields are known throughout decompressor, but generally 599 * should not be touched by a surrounding application. 600 */ 601 602 /* 603 * These fields are computed during decompression startup 604 */ 605 int max_h_samp_factor; /* largest h_samp_factor */ 606 int max_v_samp_factor; /* largest v_samp_factor */ 607 608 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 609 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 610 611 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */ 612 /* The coefficient controller's input and output progress is measured in 613 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows 614 * in fully interleaved JPEG scans, but are used whether the scan is 615 * interleaved or not. We define an iMCU row as v_samp_factor DCT block 616 * rows of each component. Therefore, the IDCT output contains 617 * v_samp_factor*DCT_v_scaled_size sample rows of a component per iMCU row. 618 */ 619 620 JSAMPLE * sample_range_limit; /* table for fast range-limiting */ 621 622 /* 623 * These fields are valid during any one scan. 624 * They describe the components and MCUs actually appearing in the scan. 625 * Note that the decompressor output side must not use these fields. 626 */ 627 int comps_in_scan; /* # of JPEG components in this scan */ 628 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 629 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 630 631 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 632 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 633 634 int blocks_in_MCU; /* # of DCT blocks per MCU */ 635 int MCU_membership[D_MAX_BLOCKS_IN_MCU]; 636 /* MCU_membership[i] is index in cur_comp_info of component owning */ 637 /* i'th block in an MCU */ 638 639 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 640 641 /* These fields are derived from Se of first SOS marker. 642 */ 643 int block_size; /* the basic DCT block size: 1..16 */ 644 const int * natural_order; /* natural-order position array for entropy decode */ 645 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */ 646 647 /* This field is shared between entropy decoder and marker parser. 648 * It is either zero or the code of a JPEG marker that has been 649 * read from the data source, but has not yet been processed. 650 */ 651 int unread_marker; 652 653 /* 654 * Links to decompression subobjects (methods, private variables of modules) 655 */ 656 struct jpeg_decomp_master * master; 657 struct jpeg_d_main_controller * main; 658 struct jpeg_d_coef_controller * coef; 659 struct jpeg_d_post_controller * post; 660 struct jpeg_input_controller * inputctl; 661 struct jpeg_marker_reader * marker; 662 struct jpeg_entropy_decoder * entropy; 663 struct jpeg_inverse_dct * idct; 664 struct jpeg_upsampler * upsample; 665 struct jpeg_color_deconverter * cconvert; 666 struct jpeg_color_quantizer * cquantize; 667 }; 668 669 670 /* "Object" declarations for JPEG modules that may be supplied or called 671 * directly by the surrounding application. 672 * As with all objects in the JPEG library, these structs only define the 673 * publicly visible methods and state variables of a module. Additional 674 * private fields may exist after the public ones. 675 */ 676 677 678 /* Error handler object */ 679 680 struct jpeg_error_mgr { 681 /* Error exit handler: does not return to caller */ 682 JMETHOD(void, error_exit, (j_common_ptr cinfo)); 683 /* Conditionally emit a trace or warning message */ 684 JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level)); 685 /* Routine that actually outputs a trace or error message */ 686 JMETHOD(void, output_message, (j_common_ptr cinfo)); 687 /* Format a message string for the most recent JPEG error or message */ 688 JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer)); 689 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */ 690 /* Reset error state variables at start of a new image */ 691 JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo)); 692 693 /* The message ID code and any parameters are saved here. 694 * A message can have one string parameter or up to 8 int parameters. 695 */ 696 int msg_code; 697 #define JMSG_STR_PARM_MAX 80 698 union { 699 int i[8]; 700 char s[JMSG_STR_PARM_MAX]; 701 } msg_parm; 702 703 /* Standard state variables for error facility */ 704 705 int trace_level; /* max msg_level that will be displayed */ 706 707 /* For recoverable corrupt-data errors, we emit a warning message, 708 * but keep going unless emit_message chooses to abort. emit_message 709 * should count warnings in num_warnings. The surrounding application 710 * can check for bad data by seeing if num_warnings is nonzero at the 711 * end of processing. 712 */ 713 long num_warnings; /* number of corrupt-data warnings */ 714 715 /* These fields point to the table(s) of error message strings. 716 * An application can change the table pointer to switch to a different 717 * message list (typically, to change the language in which errors are 718 * reported). Some applications may wish to add additional error codes 719 * that will be handled by the JPEG library error mechanism; the second 720 * table pointer is used for this purpose. 721 * 722 * First table includes all errors generated by JPEG library itself. 723 * Error code 0 is reserved for a "no such error string" message. 724 */ 725 const char * const * jpeg_message_table; /* Library errors */ 726 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */ 727 /* Second table can be added by application (see cjpeg/djpeg for example). 728 * It contains strings numbered first_addon_message..last_addon_message. 729 */ 730 const char * const * addon_message_table; /* Non-library errors */ 731 int first_addon_message; /* code for first string in addon table */ 732 int last_addon_message; /* code for last string in addon table */ 733 }; 734 735 736 /* Progress monitor object */ 737 738 struct jpeg_progress_mgr { 739 JMETHOD(void, progress_monitor, (j_common_ptr cinfo)); 740 741 long pass_counter; /* work units completed in this pass */ 742 long pass_limit; /* total number of work units in this pass */ 743 int completed_passes; /* passes completed so far */ 744 int total_passes; /* total number of passes expected */ 745 }; 746 747 748 /* Data destination object for compression */ 749 750 struct jpeg_destination_mgr { 751 JOCTET * next_output_byte; /* => next byte to write in buffer */ 752 size_t free_in_buffer; /* # of byte spaces remaining in buffer */ 753 754 JMETHOD(void, init_destination, (j_compress_ptr cinfo)); 755 JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo)); 756 JMETHOD(void, term_destination, (j_compress_ptr cinfo)); 757 }; 758 759 760 /* Data source object for decompression */ 761 762 struct jpeg_source_mgr { 763 const JOCTET * next_input_byte; /* => next byte to read from buffer */ 764 size_t bytes_in_buffer; /* # of bytes remaining in buffer */ 765 766 JMETHOD(void, init_source, (j_decompress_ptr cinfo)); 767 JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo)); 768 JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes)); 769 JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired)); 770 JMETHOD(void, term_source, (j_decompress_ptr cinfo)); 771 }; 772 773 774 /* Memory manager object. 775 * Allocates "small" objects (a few K total), "large" objects (tens of K), 776 * and "really big" objects (virtual arrays with backing store if needed). 777 * The memory manager does not allow individual objects to be freed; rather, 778 * each created object is assigned to a pool, and whole pools can be freed 779 * at once. This is faster and more convenient than remembering exactly what 780 * to free, especially where malloc()/free() are not too speedy. 781 * NB: alloc routines never return NULL. They exit to error_exit if not 782 * successful. 783 */ 784 785 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */ 786 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */ 787 #define JPOOL_NUMPOOLS 2 788 789 typedef struct jvirt_sarray_control * jvirt_sarray_ptr; 790 typedef struct jvirt_barray_control * jvirt_barray_ptr; 791 792 793 struct jpeg_memory_mgr { 794 /* Method pointers */ 795 JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id, 796 size_t sizeofobject)); 797 JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id, 798 size_t sizeofobject)); 799 JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id, 800 JDIMENSION samplesperrow, 801 JDIMENSION numrows)); 802 JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id, 803 JDIMENSION blocksperrow, 804 JDIMENSION numrows)); 805 JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo, 806 int pool_id, 807 boolean pre_zero, 808 JDIMENSION samplesperrow, 809 JDIMENSION numrows, 810 JDIMENSION maxaccess)); 811 JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo, 812 int pool_id, 813 boolean pre_zero, 814 JDIMENSION blocksperrow, 815 JDIMENSION numrows, 816 JDIMENSION maxaccess)); 817 JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo)); 818 JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo, 819 jvirt_sarray_ptr ptr, 820 JDIMENSION start_row, 821 JDIMENSION num_rows, 822 boolean writable)); 823 JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo, 824 jvirt_barray_ptr ptr, 825 JDIMENSION start_row, 826 JDIMENSION num_rows, 827 boolean writable)); 828 JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id)); 829 JMETHOD(void, self_destruct, (j_common_ptr cinfo)); 830 831 /* Limit on memory allocation for this JPEG object. (Note that this is 832 * merely advisory, not a guaranteed maximum; it only affects the space 833 * used for virtual-array buffers.) May be changed by outer application 834 * after creating the JPEG object. 835 */ 836 long max_memory_to_use; 837 838 /* Maximum allocation request accepted by alloc_large. */ 839 long max_alloc_chunk; 840 }; 841 842 843 /* Routine signature for application-supplied marker processing methods. 844 * Need not pass marker code since it is stored in cinfo->unread_marker. 845 */ 846 typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo)); 847 848 849 /* Declarations for routines called by application. 850 * The JPP macro hides prototype parameters from compilers that can't cope. 851 * Note JPP requires double parentheses. 852 */ 853 854 #ifdef HAVE_PROTOTYPES 855 #define JPP(arglist) arglist 856 #else 857 #define JPP(arglist) () 858 #endif 859 860 861 /* Short forms of external names for systems with brain-damaged linkers. 862 * We shorten external names to be unique in the first six letters, which 863 * is good enough for all known systems. 864 * (If your compiler itself needs names to be unique in less than 15 865 * characters, you are out of luck. Get a better compiler.) 866 */ 867 868 #ifdef NEED_SHORT_EXTERNAL_NAMES 869 #define jpeg_std_error jStdError 870 #define jpeg_CreateCompress jCreaCompress 871 #define jpeg_CreateDecompress jCreaDecompress 872 #define jpeg_destroy_compress jDestCompress 873 #define jpeg_destroy_decompress jDestDecompress 874 #define jpeg_stdio_dest jStdDest 875 #define jpeg_stdio_src jStdSrc 876 #define jpeg_mem_dest jMemDest 877 #define jpeg_mem_src jMemSrc 878 #define jpeg_set_defaults jSetDefaults 879 #define jpeg_set_colorspace jSetColorspace 880 #define jpeg_default_colorspace jDefColorspace 881 #define jpeg_set_quality jSetQuality 882 #define jpeg_set_linear_quality jSetLQuality 883 #define jpeg_default_qtables jDefQTables 884 #define jpeg_add_quant_table jAddQuantTable 885 #define jpeg_quality_scaling jQualityScaling 886 #define jpeg_simple_progression jSimProgress 887 #define jpeg_suppress_tables jSuppressTables 888 #define jpeg_alloc_quant_table jAlcQTable 889 #define jpeg_alloc_huff_table jAlcHTable 890 #define jpeg_start_compress jStrtCompress 891 #define jpeg_write_scanlines jWrtScanlines 892 #define jpeg_finish_compress jFinCompress 893 #define jpeg_calc_jpeg_dimensions jCjpegDimensions 894 #define jpeg_write_raw_data jWrtRawData 895 #define jpeg_write_marker jWrtMarker 896 #define jpeg_write_m_header jWrtMHeader 897 #define jpeg_write_m_byte jWrtMByte 898 #define jpeg_write_tables jWrtTables 899 #define jpeg_read_header jReadHeader 900 #define jpeg_start_decompress jStrtDecompress 901 #define jpeg_read_scanlines jReadScanlines 902 #define jpeg_finish_decompress jFinDecompress 903 #define jpeg_read_raw_data jReadRawData 904 #define jpeg_has_multiple_scans jHasMultScn 905 #define jpeg_start_output jStrtOutput 906 #define jpeg_finish_output jFinOutput 907 #define jpeg_input_complete jInComplete 908 #define jpeg_new_colormap jNewCMap 909 #define jpeg_consume_input jConsumeInput 910 #define jpeg_core_output_dimensions jCoreDimensions 911 #define jpeg_calc_output_dimensions jCalcDimensions 912 #define jpeg_save_markers jSaveMarkers 913 #define jpeg_set_marker_processor jSetMarker 914 #define jpeg_read_coefficients jReadCoefs 915 #define jpeg_write_coefficients jWrtCoefs 916 #define jpeg_copy_critical_parameters jCopyCrit 917 #define jpeg_abort_compress jAbrtCompress 918 #define jpeg_abort_decompress jAbrtDecompress 919 #define jpeg_abort jAbort 920 #define jpeg_destroy jDestroy 921 #define jpeg_resync_to_restart jResyncRestart 922 #endif /* NEED_SHORT_EXTERNAL_NAMES */ 923 924 925 /* Default error-management setup */ 926 EXTERN(struct jpeg_error_mgr *) jpeg_std_error 927 JPP((struct jpeg_error_mgr * err)); 928 929 /* Initialization of JPEG compression objects. 930 * jpeg_create_compress() and jpeg_create_decompress() are the exported 931 * names that applications should call. These expand to calls on 932 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information 933 * passed for version mismatch checking. 934 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx. 935 */ 936 #define jpeg_create_compress(cinfo) \ 937 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \ 938 (size_t) sizeof(struct jpeg_compress_struct)) 939 #define jpeg_create_decompress(cinfo) \ 940 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \ 941 (size_t) sizeof(struct jpeg_decompress_struct)) 942 EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo, 943 int version, size_t structsize)); 944 EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo, 945 int version, size_t structsize)); 946 /* Destruction of JPEG compression objects */ 947 EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo)); 948 EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo)); 949 950 /* Standard data source and destination managers: stdio streams. */ 951 /* Caller is responsible for opening the file before and closing after. */ 952 EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile)); 953 EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile)); 954 955 /* Data source and destination managers: memory buffers. */ 956 EXTERN(void) jpeg_mem_dest JPP((j_compress_ptr cinfo, 957 unsigned char ** outbuffer, 958 unsigned long * outsize)); 959 EXTERN(void) jpeg_mem_src JPP((j_decompress_ptr cinfo, 960 unsigned char * inbuffer, 961 unsigned long insize)); 962 963 /* Default parameter setup for compression */ 964 EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo)); 965 /* Compression parameter setup aids */ 966 EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo, 967 J_COLOR_SPACE colorspace)); 968 EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo)); 969 EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality, 970 boolean force_baseline)); 971 EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo, 972 int scale_factor, 973 boolean force_baseline)); 974 EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo, 975 boolean force_baseline)); 976 EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl, 977 const unsigned int *basic_table, 978 int scale_factor, 979 boolean force_baseline)); 980 EXTERN(int) jpeg_quality_scaling JPP((int quality)); 981 EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo)); 982 EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo, 983 boolean suppress)); 984 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo)); 985 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo)); 986 987 /* Main entry points for compression */ 988 EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo, 989 boolean write_all_tables)); 990 EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo, 991 JSAMPARRAY scanlines, 992 JDIMENSION num_lines)); 993 EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo)); 994 995 /* Precalculate JPEG dimensions for current compression parameters. */ 996 EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo)); 997 998 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */ 999 EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo, 1000 JSAMPIMAGE data, 1001 JDIMENSION num_lines)); 1002 1003 /* Write a special marker. See libjpeg.txt concerning safe usage. */ 1004 EXTERN(void) jpeg_write_marker 1005 JPP((j_compress_ptr cinfo, int marker, 1006 const JOCTET * dataptr, unsigned int datalen)); 1007 /* Same, but piecemeal. */ 1008 EXTERN(void) jpeg_write_m_header 1009 JPP((j_compress_ptr cinfo, int marker, unsigned int datalen)); 1010 EXTERN(void) jpeg_write_m_byte 1011 JPP((j_compress_ptr cinfo, int val)); 1012 1013 /* Alternate compression function: just write an abbreviated table file */ 1014 EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo)); 1015 1016 /* Decompression startup: read start of JPEG datastream to see what's there */ 1017 EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo, 1018 boolean require_image)); 1019 /* Return value is one of: */ 1020 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */ 1021 #define JPEG_HEADER_OK 1 /* Found valid image datastream */ 1022 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */ 1023 /* If you pass require_image = TRUE (normal case), you need not check for 1024 * a TABLES_ONLY return code; an abbreviated file will cause an error exit. 1025 * JPEG_SUSPENDED is only possible if you use a data source module that can 1026 * give a suspension return (the stdio source module doesn't). 1027 */ 1028 1029 /* Main entry points for decompression */ 1030 EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo)); 1031 EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo, 1032 JSAMPARRAY scanlines, 1033 JDIMENSION max_lines)); 1034 EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo)); 1035 1036 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */ 1037 EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo, 1038 JSAMPIMAGE data, 1039 JDIMENSION max_lines)); 1040 1041 /* Additional entry points for buffered-image mode. */ 1042 EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo)); 1043 EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo, 1044 int scan_number)); 1045 EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo)); 1046 EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo)); 1047 EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo)); 1048 EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo)); 1049 /* Return value is one of: */ 1050 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */ 1051 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */ 1052 #define JPEG_REACHED_EOI 2 /* Reached end of image */ 1053 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */ 1054 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */ 1055 1056 /* Precalculate output dimensions for current decompression parameters. */ 1057 EXTERN(void) jpeg_core_output_dimensions JPP((j_decompress_ptr cinfo)); 1058 EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo)); 1059 1060 /* Control saving of COM and APPn markers into marker_list. */ 1061 EXTERN(void) jpeg_save_markers 1062 JPP((j_decompress_ptr cinfo, int marker_code, 1063 unsigned int length_limit)); 1064 1065 /* Install a special processing method for COM or APPn markers. */ 1066 EXTERN(void) jpeg_set_marker_processor 1067 JPP((j_decompress_ptr cinfo, int marker_code, 1068 jpeg_marker_parser_method routine)); 1069 1070 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */ 1071 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo)); 1072 EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo, 1073 jvirt_barray_ptr * coef_arrays)); 1074 EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo, 1075 j_compress_ptr dstinfo)); 1076 1077 /* If you choose to abort compression or decompression before completing 1078 * jpeg_finish_(de)compress, then you need to clean up to release memory, 1079 * temporary files, etc. You can just call jpeg_destroy_(de)compress 1080 * if you're done with the JPEG object, but if you want to clean it up and 1081 * reuse it, call this: 1082 */ 1083 EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo)); 1084 EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo)); 1085 1086 /* Generic versions of jpeg_abort and jpeg_destroy that work on either 1087 * flavor of JPEG object. These may be more convenient in some places. 1088 */ 1089 EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo)); 1090 EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo)); 1091 1092 /* Default restart-marker-resync procedure for use by data source modules */ 1093 EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo, 1094 int desired)); 1095 1096 1097 /* These marker codes are exported since applications and data source modules 1098 * are likely to want to use them. 1099 */ 1100 1101 #define JPEG_RST0 0xD0 /* RST0 marker code */ 1102 #define JPEG_EOI 0xD9 /* EOI marker code */ 1103 #define JPEG_APP0 0xE0 /* APP0 marker code */ 1104 #define JPEG_COM 0xFE /* COM marker code */ 1105 1106 1107 /* If we have a brain-damaged compiler that emits warnings (or worse, errors) 1108 * for structure definitions that are never filled in, keep it quiet by 1109 * supplying dummy definitions for the various substructures. 1110 */ 1111 1112 #ifdef INCOMPLETE_TYPES_BROKEN 1113 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */ 1114 struct jvirt_sarray_control { long dummy; }; 1115 struct jvirt_barray_control { long dummy; }; 1116 struct jpeg_comp_master { long dummy; }; 1117 struct jpeg_c_main_controller { long dummy; }; 1118 struct jpeg_c_prep_controller { long dummy; }; 1119 struct jpeg_c_coef_controller { long dummy; }; 1120 struct jpeg_marker_writer { long dummy; }; 1121 struct jpeg_color_converter { long dummy; }; 1122 struct jpeg_downsampler { long dummy; }; 1123 struct jpeg_forward_dct { long dummy; }; 1124 struct jpeg_entropy_encoder { long dummy; }; 1125 struct jpeg_decomp_master { long dummy; }; 1126 struct jpeg_d_main_controller { long dummy; }; 1127 struct jpeg_d_coef_controller { long dummy; }; 1128 struct jpeg_d_post_controller { long dummy; }; 1129 struct jpeg_input_controller { long dummy; }; 1130 struct jpeg_marker_reader { long dummy; }; 1131 struct jpeg_entropy_decoder { long dummy; }; 1132 struct jpeg_inverse_dct { long dummy; }; 1133 struct jpeg_upsampler { long dummy; }; 1134 struct jpeg_color_deconverter { long dummy; }; 1135 struct jpeg_color_quantizer { long dummy; }; 1136 #endif /* JPEG_INTERNALS */ 1137 #endif /* INCOMPLETE_TYPES_BROKEN */ 1138 1139 1140 /* 1141 * The JPEG library modules define JPEG_INTERNALS before including this file. 1142 * The internal structure declarations are read only when that is true. 1143 * Applications using the library should not include jpegint.h, but may wish 1144 * to include jerror.h. 1145 */ 1146 1147 #ifdef JPEG_INTERNALS 1148 #include "jpegint.h" /* fetch private declarations */ 1149 #include "jerror.h" /* fetch error codes too */ 1150 #endif 1151 1152 #ifdef __cplusplus 1153 #ifndef DONT_USE_EXTERN_C 1154 } 1155 #endif 1156 #endif 1157 1158 #endif /* JPEGLIB_H */ 1159