1 /* 2 * jpeglib.h 3 * 4 * Copyright (C) 1991-1998, Thomas G. Lane. 5 * Modified 2002-2017 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 >= 90". 38 */ 39 40 #define JPEG_LIB_VERSION 90 /* Compatibility version 9.0 */ 41 #define JPEG_LIB_VERSION_MAJOR 9 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, 47 * so don't change them if you want to be compatible. 48 */ 49 50 #define DCTSIZE 8 /* The basic DCT block is 8x8 coefficients */ 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 = 161 * ceil(image_width * Hi/Hmax * DCT_h_scaled_size/block_size) 162 * and similarly for height. 163 */ 164 JDIMENSION downsampled_width; /* actual width in samples */ 165 JDIMENSION downsampled_height; /* actual height in samples */ 166 /* For decompression, in cases where some of the components will be 167 * ignored (eg grayscale output from YCbCr image), we can skip most 168 * computations for the unused components. 169 * For compression, some of the components will need further quantization 170 * scale by factor of 2 after DCT (eg BG_YCC output from normal RGB input). 171 * The field is first set TRUE for decompression, FALSE for compression 172 * in initial_setup, and then adapted in color conversion setup. 173 */ 174 boolean component_needed; 175 176 /* These values are computed before starting a scan of the component. */ 177 /* The decompressor output side may not use these variables. */ 178 int MCU_width; /* number of blocks per MCU, horizontally */ 179 int MCU_height; /* number of blocks per MCU, vertically */ 180 int MCU_blocks; /* MCU_width * MCU_height */ 181 int MCU_sample_width; /* MCU width in samples: MCU_width * DCT_h_scaled_size */ 182 int last_col_width; /* # of non-dummy blocks across in last MCU */ 183 int last_row_height; /* # of non-dummy blocks down in last MCU */ 184 185 /* Saved quantization table for component; NULL if none yet saved. 186 * See jdinput.c comments about the need for this information. 187 * This field is currently used only for decompression. 188 */ 189 JQUANT_TBL * quant_table; 190 191 /* Private per-component storage for DCT or IDCT subsystem. */ 192 void * dct_table; 193 } jpeg_component_info; 194 195 196 /* The script for encoding a multiple-scan file is an array of these: */ 197 198 typedef struct { 199 int comps_in_scan; /* number of components encoded in this scan */ 200 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */ 201 int Ss, Se; /* progressive JPEG spectral selection parms */ 202 int Ah, Al; /* progressive JPEG successive approx. parms */ 203 } jpeg_scan_info; 204 205 /* The decompressor can save APPn and COM markers in a list of these: */ 206 207 typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr; 208 209 struct jpeg_marker_struct { 210 jpeg_saved_marker_ptr next; /* next in list, or NULL */ 211 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */ 212 unsigned int original_length; /* # bytes of data in the file */ 213 unsigned int data_length; /* # bytes of data saved at data[] */ 214 JOCTET FAR * data; /* the data contained in the marker */ 215 /* the marker length word is not counted in data_length or original_length */ 216 }; 217 218 /* Known color spaces. */ 219 220 typedef enum { 221 JCS_UNKNOWN, /* error/unspecified */ 222 JCS_GRAYSCALE, /* monochrome */ 223 JCS_RGB, /* red/green/blue, standard RGB (sRGB) */ 224 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV), standard YCC */ 225 JCS_CMYK, /* C/M/Y/K */ 226 JCS_YCCK, /* Y/Cb/Cr/K */ 227 JCS_BG_RGB, /* big gamut red/green/blue, bg-sRGB */ 228 JCS_BG_YCC /* big gamut Y/Cb/Cr, bg-sYCC */ 229 } J_COLOR_SPACE; 230 231 /* Supported color transforms. */ 232 233 typedef enum { 234 JCT_NONE = 0, 235 JCT_SUBTRACT_GREEN = 1 236 } J_COLOR_TRANSFORM; 237 238 /* DCT/IDCT algorithm options. */ 239 240 typedef enum { 241 JDCT_ISLOW, /* slow but accurate integer algorithm */ 242 JDCT_IFAST, /* faster, less accurate integer method */ 243 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */ 244 } J_DCT_METHOD; 245 246 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */ 247 #define JDCT_DEFAULT JDCT_ISLOW 248 #endif 249 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */ 250 #define JDCT_FASTEST JDCT_IFAST 251 #endif 252 253 /* Dithering options for decompression. */ 254 255 typedef enum { 256 JDITHER_NONE, /* no dithering */ 257 JDITHER_ORDERED, /* simple ordered dither */ 258 JDITHER_FS /* Floyd-Steinberg error diffusion dither */ 259 } J_DITHER_MODE; 260 261 262 /* Common fields between JPEG compression and decompression master structs. */ 263 264 #define jpeg_common_fields \ 265 struct jpeg_error_mgr * err; /* Error handler module */\ 266 struct jpeg_memory_mgr * mem; /* Memory manager module */\ 267 struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\ 268 void * client_data; /* Available for use by application */\ 269 boolean is_decompressor; /* So common code can tell which is which */\ 270 int global_state /* For checking call sequence validity */ 271 272 /* Routines that are to be used by both halves of the library are declared 273 * to receive a pointer to this structure. There are no actual instances of 274 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct. 275 */ 276 struct jpeg_common_struct { 277 jpeg_common_fields; /* Fields common to both master struct types */ 278 /* Additional fields follow in an actual jpeg_compress_struct or 279 * jpeg_decompress_struct. All three structs must agree on these 280 * initial fields! (This would be a lot cleaner in C++.) 281 */ 282 }; 283 284 typedef struct jpeg_common_struct * j_common_ptr; 285 typedef struct jpeg_compress_struct * j_compress_ptr; 286 typedef struct jpeg_decompress_struct * j_decompress_ptr; 287 288 289 /* Master record for a compression instance */ 290 291 struct jpeg_compress_struct { 292 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */ 293 294 /* Destination for compressed data */ 295 struct jpeg_destination_mgr * dest; 296 297 /* Description of source image --- these fields must be filled in by 298 * outer application before starting compression. in_color_space must 299 * be correct before you can even call jpeg_set_defaults(). 300 */ 301 302 JDIMENSION image_width; /* input image width */ 303 JDIMENSION image_height; /* input image height */ 304 int input_components; /* # of color components in input image */ 305 J_COLOR_SPACE in_color_space; /* colorspace of input image */ 306 307 double input_gamma; /* image gamma of input image */ 308 309 /* Compression parameters --- these fields must be set before calling 310 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to 311 * initialize everything to reasonable defaults, then changing anything 312 * the application specifically wants to change. That way you won't get 313 * burnt when new parameters are added. Also note that there are several 314 * helper routines to simplify changing parameters. 315 */ 316 317 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 318 319 JDIMENSION jpeg_width; /* scaled JPEG image width */ 320 JDIMENSION jpeg_height; /* scaled JPEG image height */ 321 /* Dimensions of actual JPEG image that will be written to file, 322 * derived from input dimensions by scaling factors above. 323 * These fields are computed by jpeg_start_compress(). 324 * You can also use jpeg_calc_jpeg_dimensions() to determine these values 325 * in advance of calling jpeg_start_compress(). 326 */ 327 328 int data_precision; /* bits of precision in image data */ 329 330 int num_components; /* # of color components in JPEG image */ 331 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 332 333 jpeg_component_info * comp_info; 334 /* comp_info[i] describes component that appears i'th in SOF */ 335 336 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 337 int q_scale_factor[NUM_QUANT_TBLS]; 338 /* ptrs to coefficient quantization tables, or NULL if not defined, 339 * and corresponding scale factors (percentage, initialized 100). 340 */ 341 342 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 343 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 344 /* ptrs to Huffman coding tables, or NULL if not defined */ 345 346 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 347 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 348 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 349 350 int num_scans; /* # of entries in scan_info array */ 351 const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */ 352 /* The default value of scan_info is NULL, which causes a single-scan 353 * sequential JPEG file to be emitted. To create a multi-scan file, 354 * set num_scans and scan_info to point to an array of scan definitions. 355 */ 356 357 boolean raw_data_in; /* TRUE=caller supplies downsampled data */ 358 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 359 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */ 360 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 361 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */ 362 int smoothing_factor; /* 1..100, or 0 for no input smoothing */ 363 J_DCT_METHOD dct_method; /* DCT algorithm selector */ 364 365 /* The restart interval can be specified in absolute MCUs by setting 366 * restart_interval, or in MCU rows by setting restart_in_rows 367 * (in which case the correct restart_interval will be figured 368 * for each scan). 369 */ 370 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */ 371 int restart_in_rows; /* if > 0, MCU rows per restart interval */ 372 373 /* Parameters controlling emission of special markers. */ 374 375 boolean write_JFIF_header; /* should a JFIF marker be written? */ 376 UINT8 JFIF_major_version; /* What to write for the JFIF version number */ 377 UINT8 JFIF_minor_version; 378 /* These three values are not used by the JPEG code, merely copied */ 379 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */ 380 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */ 381 /* ratio is defined by X_density/Y_density even when density_unit=0. */ 382 UINT8 density_unit; /* JFIF code for pixel size units */ 383 UINT16 X_density; /* Horizontal pixel density */ 384 UINT16 Y_density; /* Vertical pixel density */ 385 boolean write_Adobe_marker; /* should an Adobe marker be written? */ 386 387 J_COLOR_TRANSFORM color_transform; 388 /* Color transform identifier, writes LSE marker if nonzero */ 389 390 /* State variable: index of next scanline to be written to 391 * jpeg_write_scanlines(). Application may use this to control its 392 * processing loop, e.g., "while (next_scanline < image_height)". 393 */ 394 395 JDIMENSION next_scanline; /* 0 .. image_height-1 */ 396 397 /* Remaining fields are known throughout compressor, but generally 398 * should not be touched by a surrounding application. 399 */ 400 401 /* 402 * These fields are computed during compression startup 403 */ 404 boolean progressive_mode; /* TRUE if scan script uses progressive mode */ 405 int max_h_samp_factor; /* largest h_samp_factor */ 406 int max_v_samp_factor; /* largest v_samp_factor */ 407 408 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 409 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 410 411 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */ 412 /* The coefficient controller receives data in units of MCU rows as defined 413 * for fully interleaved scans (whether the JPEG file is interleaved or not). 414 * There are v_samp_factor * DCT_v_scaled_size sample rows of each component 415 * in an "iMCU" (interleaved MCU) row. 416 */ 417 418 /* 419 * These fields are valid during any one scan. 420 * They describe the components and MCUs actually appearing in the scan. 421 */ 422 int comps_in_scan; /* # of JPEG components in this scan */ 423 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 424 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 425 426 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 427 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 428 429 int blocks_in_MCU; /* # of DCT blocks per MCU */ 430 int MCU_membership[C_MAX_BLOCKS_IN_MCU]; 431 /* MCU_membership[i] is index in cur_comp_info of component owning */ 432 /* i'th block in an MCU */ 433 434 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 435 436 int block_size; /* the basic DCT block size: 1..16 */ 437 const int * natural_order; /* natural-order position array */ 438 int lim_Se; /* min( Se, DCTSIZE2-1 ) */ 439 440 /* 441 * Links to compression subobjects (methods and private variables of modules) 442 */ 443 struct jpeg_comp_master * master; 444 struct jpeg_c_main_controller * main; 445 struct jpeg_c_prep_controller * prep; 446 struct jpeg_c_coef_controller * coef; 447 struct jpeg_marker_writer * marker; 448 struct jpeg_color_converter * cconvert; 449 struct jpeg_downsampler * downsample; 450 struct jpeg_forward_dct * fdct; 451 struct jpeg_entropy_encoder * entropy; 452 jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */ 453 int script_space_size; 454 }; 455 456 457 /* Master record for a decompression instance */ 458 459 struct jpeg_decompress_struct { 460 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */ 461 462 /* Source of compressed data */ 463 struct jpeg_source_mgr * src; 464 465 /* Basic description of image --- filled in by jpeg_read_header(). */ 466 /* Application may inspect these values to decide how to process image. */ 467 468 JDIMENSION image_width; /* nominal image width (from SOF marker) */ 469 JDIMENSION image_height; /* nominal image height */ 470 int num_components; /* # of color components in JPEG image */ 471 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 472 473 /* Decompression processing parameters --- these fields must be set before 474 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes 475 * them to default values. 476 */ 477 478 J_COLOR_SPACE out_color_space; /* colorspace for output */ 479 480 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 481 482 double output_gamma; /* image gamma wanted in output */ 483 484 boolean buffered_image; /* TRUE=multiple output passes */ 485 boolean raw_data_out; /* TRUE=downsampled data wanted */ 486 487 J_DCT_METHOD dct_method; /* IDCT algorithm selector */ 488 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */ 489 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */ 490 491 boolean quantize_colors; /* TRUE=colormapped output wanted */ 492 /* the following are ignored if not quantize_colors: */ 493 J_DITHER_MODE dither_mode; /* type of color dithering to use */ 494 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */ 495 int desired_number_of_colors; /* max # colors to use in created colormap */ 496 /* these are significant only in buffered-image mode: */ 497 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */ 498 boolean enable_external_quant;/* enable future use of external colormap */ 499 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */ 500 501 /* Description of actual output image that will be returned to application. 502 * These fields are computed by jpeg_start_decompress(). 503 * You can also use jpeg_calc_output_dimensions() to determine these values 504 * in advance of calling jpeg_start_decompress(). 505 */ 506 507 JDIMENSION output_width; /* scaled image width */ 508 JDIMENSION output_height; /* scaled image height */ 509 int out_color_components; /* # of color components in out_color_space */ 510 int output_components; /* # of color components returned */ 511 /* output_components is 1 (a colormap index) when quantizing colors; 512 * otherwise it equals out_color_components. 513 */ 514 int rec_outbuf_height; /* min recommended height of scanline buffer */ 515 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows 516 * high, space and time will be wasted due to unnecessary data copying. 517 * Usually rec_outbuf_height will be 1 or 2, at most 4. 518 */ 519 520 /* When quantizing colors, the output colormap is described by these fields. 521 * The application can supply a colormap by setting colormap non-NULL before 522 * calling jpeg_start_decompress; otherwise a colormap is created during 523 * jpeg_start_decompress or jpeg_start_output. 524 * The map has out_color_components rows and actual_number_of_colors columns. 525 */ 526 int actual_number_of_colors; /* number of entries in use */ 527 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */ 528 529 /* State variables: these variables indicate the progress of decompression. 530 * The application may examine these but must not modify them. 531 */ 532 533 /* Row index of next scanline to be read from jpeg_read_scanlines(). 534 * Application may use this to control its processing loop, e.g., 535 * "while (output_scanline < output_height)". 536 */ 537 JDIMENSION output_scanline; /* 0 .. output_height-1 */ 538 539 /* Current input scan number and number of iMCU rows completed in scan. 540 * These indicate the progress of the decompressor input side. 541 */ 542 int input_scan_number; /* Number of SOS markers seen so far */ 543 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */ 544 545 /* The "output scan number" is the notional scan being displayed by the 546 * output side. The decompressor will not allow output scan/row number 547 * to get ahead of input scan/row, but it can fall arbitrarily far behind. 548 */ 549 int output_scan_number; /* Nominal scan number being displayed */ 550 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */ 551 552 /* Current progression status. coef_bits[c][i] indicates the precision 553 * with which component c's DCT coefficient i (in zigzag order) is known. 554 * It is -1 when no data has yet been received, otherwise it is the point 555 * transform (shift) value for the most recent scan of the coefficient 556 * (thus, 0 at completion of the progression). 557 * This pointer is NULL when reading a non-progressive file. 558 */ 559 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */ 560 561 /* Internal JPEG parameters --- the application usually need not look at 562 * these fields. Note that the decompressor output side may not use 563 * any parameters that can change between scans. 564 */ 565 566 /* Quantization and Huffman tables are carried forward across input 567 * datastreams when processing abbreviated JPEG datastreams. 568 */ 569 570 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 571 /* ptrs to coefficient quantization tables, or NULL if not defined */ 572 573 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 574 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 575 /* ptrs to Huffman coding tables, or NULL if not defined */ 576 577 /* These parameters are never carried across datastreams, since they 578 * are given in SOF/SOS markers or defined to be reset by SOI. 579 */ 580 581 int data_precision; /* bits of precision in image data */ 582 583 jpeg_component_info * comp_info; 584 /* comp_info[i] describes component that appears i'th in SOF */ 585 586 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */ 587 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */ 588 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 589 590 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 591 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 592 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 593 594 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */ 595 596 /* These fields record data obtained from optional markers recognized by 597 * the JPEG library. 598 */ 599 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */ 600 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */ 601 UINT8 JFIF_major_version; /* JFIF version number */ 602 UINT8 JFIF_minor_version; 603 UINT8 density_unit; /* JFIF code for pixel size units */ 604 UINT16 X_density; /* Horizontal pixel density */ 605 UINT16 Y_density; /* Vertical pixel density */ 606 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */ 607 UINT8 Adobe_transform; /* Color transform code from Adobe marker */ 608 609 J_COLOR_TRANSFORM color_transform; 610 /* Color transform identifier derived from LSE marker, otherwise zero */ 611 612 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 613 614 /* Aside from the specific data retained from APPn markers known to the 615 * library, the uninterpreted contents of any or all APPn and COM markers 616 * can be saved in a list for examination by the application. 617 */ 618 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */ 619 620 /* Remaining fields are known throughout decompressor, but generally 621 * should not be touched by a surrounding application. 622 */ 623 624 /* 625 * These fields are computed during decompression startup 626 */ 627 int max_h_samp_factor; /* largest h_samp_factor */ 628 int max_v_samp_factor; /* largest v_samp_factor */ 629 630 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 631 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 632 633 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */ 634 /* The coefficient controller's input and output progress is measured in 635 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows 636 * in fully interleaved JPEG scans, but are used whether the scan is 637 * interleaved or not. We define an iMCU row as v_samp_factor DCT block 638 * rows of each component. Therefore, the IDCT output contains 639 * v_samp_factor * DCT_v_scaled_size sample rows of a component per iMCU row. 640 */ 641 642 JSAMPLE * sample_range_limit; /* table for fast range-limiting */ 643 644 /* 645 * These fields are valid during any one scan. 646 * They describe the components and MCUs actually appearing in the scan. 647 * Note that the decompressor output side must not use these fields. 648 */ 649 int comps_in_scan; /* # of JPEG components in this scan */ 650 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 651 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 652 653 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 654 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 655 656 int blocks_in_MCU; /* # of DCT blocks per MCU */ 657 int MCU_membership[D_MAX_BLOCKS_IN_MCU]; 658 /* MCU_membership[i] is index in cur_comp_info of component owning */ 659 /* i'th block in an MCU */ 660 661 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 662 663 /* These fields are derived from Se of first SOS marker. 664 */ 665 int block_size; /* the basic DCT block size: 1..16 */ 666 const int * natural_order; /* natural-order position array for entropy decode */ 667 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */ 668 669 /* This field is shared between entropy decoder and marker parser. 670 * It is either zero or the code of a JPEG marker that has been 671 * read from the data source, but has not yet been processed. 672 */ 673 int unread_marker; 674 675 /* 676 * Links to decompression subobjects (methods, private variables of modules) 677 */ 678 struct jpeg_decomp_master * master; 679 struct jpeg_d_main_controller * main; 680 struct jpeg_d_coef_controller * coef; 681 struct jpeg_d_post_controller * post; 682 struct jpeg_input_controller * inputctl; 683 struct jpeg_marker_reader * marker; 684 struct jpeg_entropy_decoder * entropy; 685 struct jpeg_inverse_dct * idct; 686 struct jpeg_upsampler * upsample; 687 struct jpeg_color_deconverter * cconvert; 688 struct jpeg_color_quantizer * cquantize; 689 }; 690 691 692 /* "Object" declarations for JPEG modules that may be supplied or called 693 * directly by the surrounding application. 694 * As with all objects in the JPEG library, these structs only define the 695 * publicly visible methods and state variables of a module. Additional 696 * private fields may exist after the public ones. 697 */ 698 699 700 /* Error handler object */ 701 702 struct jpeg_error_mgr { 703 /* Error exit handler: does not return to caller */ 704 JMETHOD(noreturn_t, error_exit, (j_common_ptr cinfo)); 705 /* Conditionally emit a trace or warning message */ 706 JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level)); 707 /* Routine that actually outputs a trace or error message */ 708 JMETHOD(void, output_message, (j_common_ptr cinfo)); 709 /* Format a message string for the most recent JPEG error or message */ 710 JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer)); 711 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */ 712 /* Reset error state variables at start of a new image */ 713 JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo)); 714 715 /* The message ID code and any parameters are saved here. 716 * A message can have one string parameter or up to 8 int parameters. 717 */ 718 int msg_code; 719 #define JMSG_STR_PARM_MAX 80 720 union { 721 int i[8]; 722 char s[JMSG_STR_PARM_MAX]; 723 } msg_parm; 724 725 /* Standard state variables for error facility */ 726 727 int trace_level; /* max msg_level that will be displayed */ 728 729 /* For recoverable corrupt-data errors, we emit a warning message, 730 * but keep going unless emit_message chooses to abort. emit_message 731 * should count warnings in num_warnings. The surrounding application 732 * can check for bad data by seeing if num_warnings is nonzero at the 733 * end of processing. 734 */ 735 long num_warnings; /* number of corrupt-data warnings */ 736 737 /* These fields point to the table(s) of error message strings. 738 * An application can change the table pointer to switch to a different 739 * message list (typically, to change the language in which errors are 740 * reported). Some applications may wish to add additional error codes 741 * that will be handled by the JPEG library error mechanism; the second 742 * table pointer is used for this purpose. 743 * 744 * First table includes all errors generated by JPEG library itself. 745 * Error code 0 is reserved for a "no such error string" message. 746 */ 747 const char * const * jpeg_message_table; /* Library errors */ 748 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */ 749 /* Second table can be added by application (see cjpeg/djpeg for example). 750 * It contains strings numbered first_addon_message..last_addon_message. 751 */ 752 const char * const * addon_message_table; /* Non-library errors */ 753 int first_addon_message; /* code for first string in addon table */ 754 int last_addon_message; /* code for last string in addon table */ 755 }; 756 757 758 /* Progress monitor object */ 759 760 struct jpeg_progress_mgr { 761 JMETHOD(void, progress_monitor, (j_common_ptr cinfo)); 762 763 long pass_counter; /* work units completed in this pass */ 764 long pass_limit; /* total number of work units in this pass */ 765 int completed_passes; /* passes completed so far */ 766 int total_passes; /* total number of passes expected */ 767 }; 768 769 770 /* Data destination object for compression */ 771 772 struct jpeg_destination_mgr { 773 JOCTET * next_output_byte; /* => next byte to write in buffer */ 774 size_t free_in_buffer; /* # of byte spaces remaining in buffer */ 775 776 JMETHOD(void, init_destination, (j_compress_ptr cinfo)); 777 JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo)); 778 JMETHOD(void, term_destination, (j_compress_ptr cinfo)); 779 }; 780 781 782 /* Data source object for decompression */ 783 784 struct jpeg_source_mgr { 785 const JOCTET * next_input_byte; /* => next byte to read from buffer */ 786 size_t bytes_in_buffer; /* # of bytes remaining in buffer */ 787 788 JMETHOD(void, init_source, (j_decompress_ptr cinfo)); 789 JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo)); 790 JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes)); 791 JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired)); 792 JMETHOD(void, term_source, (j_decompress_ptr cinfo)); 793 }; 794 795 796 /* Memory manager object. 797 * Allocates "small" objects (a few K total), "large" objects (tens of K), 798 * and "really big" objects (virtual arrays with backing store if needed). 799 * The memory manager does not allow individual objects to be freed; rather, 800 * each created object is assigned to a pool, and whole pools can be freed 801 * at once. This is faster and more convenient than remembering exactly what 802 * to free, especially where malloc()/free() are not too speedy. 803 * NB: alloc routines never return NULL. They exit to error_exit if not 804 * successful. 805 */ 806 807 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */ 808 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */ 809 #define JPOOL_NUMPOOLS 2 810 811 typedef struct jvirt_sarray_control * jvirt_sarray_ptr; 812 typedef struct jvirt_barray_control * jvirt_barray_ptr; 813 814 815 struct jpeg_memory_mgr { 816 /* Method pointers */ 817 JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id, 818 size_t sizeofobject)); 819 JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id, 820 size_t sizeofobject)); 821 JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id, 822 JDIMENSION samplesperrow, 823 JDIMENSION numrows)); 824 JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id, 825 JDIMENSION blocksperrow, 826 JDIMENSION numrows)); 827 JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo, 828 int pool_id, 829 boolean pre_zero, 830 JDIMENSION samplesperrow, 831 JDIMENSION numrows, 832 JDIMENSION maxaccess)); 833 JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo, 834 int pool_id, 835 boolean pre_zero, 836 JDIMENSION blocksperrow, 837 JDIMENSION numrows, 838 JDIMENSION maxaccess)); 839 JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo)); 840 JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo, 841 jvirt_sarray_ptr ptr, 842 JDIMENSION start_row, 843 JDIMENSION num_rows, 844 boolean writable)); 845 JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo, 846 jvirt_barray_ptr ptr, 847 JDIMENSION start_row, 848 JDIMENSION num_rows, 849 boolean writable)); 850 JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id)); 851 JMETHOD(void, self_destruct, (j_common_ptr cinfo)); 852 853 /* Limit on memory allocation for this JPEG object. (Note that this is 854 * merely advisory, not a guaranteed maximum; it only affects the space 855 * used for virtual-array buffers.) May be changed by outer application 856 * after creating the JPEG object. 857 */ 858 long max_memory_to_use; 859 860 /* Maximum allocation request accepted by alloc_large. */ 861 long max_alloc_chunk; 862 }; 863 864 865 /* Routine signature for application-supplied marker processing methods. 866 * Need not pass marker code since it is stored in cinfo->unread_marker. 867 */ 868 typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo)); 869 870 871 /* Declarations for routines called by application. 872 * The JPP macro hides prototype parameters from compilers that can't cope. 873 * Note JPP requires double parentheses. 874 */ 875 876 #ifdef HAVE_PROTOTYPES 877 #define JPP(arglist) arglist 878 #else 879 #define JPP(arglist) () 880 #endif 881 882 883 /* Short forms of external names for systems with brain-damaged linkers. 884 * We shorten external names to be unique in the first six letters, which 885 * is good enough for all known systems. 886 * (If your compiler itself needs names to be unique in less than 15 887 * characters, you are out of luck. Get a better compiler.) 888 */ 889 890 #ifdef NEED_SHORT_EXTERNAL_NAMES 891 #define jpeg_std_error jStdError 892 #define jpeg_CreateCompress jCreaCompress 893 #define jpeg_CreateDecompress jCreaDecompress 894 #define jpeg_destroy_compress jDestCompress 895 #define jpeg_destroy_decompress jDestDecompress 896 #define jpeg_stdio_dest jStdDest 897 #define jpeg_stdio_src jStdSrc 898 #define jpeg_mem_dest jMemDest 899 #define jpeg_mem_src jMemSrc 900 #define jpeg_set_defaults jSetDefaults 901 #define jpeg_set_colorspace jSetColorspace 902 #define jpeg_default_colorspace jDefColorspace 903 #define jpeg_set_quality jSetQuality 904 #define jpeg_set_linear_quality jSetLQuality 905 #define jpeg_default_qtables jDefQTables 906 #define jpeg_add_quant_table jAddQuantTable 907 #define jpeg_quality_scaling jQualityScaling 908 #define jpeg_simple_progression jSimProgress 909 #define jpeg_suppress_tables jSuppressTables 910 #define jpeg_alloc_quant_table jAlcQTable 911 #define jpeg_alloc_huff_table jAlcHTable 912 #define jpeg_start_compress jStrtCompress 913 #define jpeg_write_scanlines jWrtScanlines 914 #define jpeg_finish_compress jFinCompress 915 #define jpeg_calc_jpeg_dimensions jCjpegDimensions 916 #define jpeg_write_raw_data jWrtRawData 917 #define jpeg_write_marker jWrtMarker 918 #define jpeg_write_m_header jWrtMHeader 919 #define jpeg_write_m_byte jWrtMByte 920 #define jpeg_write_tables jWrtTables 921 #define jpeg_read_header jReadHeader 922 #define jpeg_start_decompress jStrtDecompress 923 #define jpeg_read_scanlines jReadScanlines 924 #define jpeg_finish_decompress jFinDecompress 925 #define jpeg_read_raw_data jReadRawData 926 #define jpeg_has_multiple_scans jHasMultScn 927 #define jpeg_start_output jStrtOutput 928 #define jpeg_finish_output jFinOutput 929 #define jpeg_input_complete jInComplete 930 #define jpeg_new_colormap jNewCMap 931 #define jpeg_consume_input jConsumeInput 932 #define jpeg_core_output_dimensions jCoreDimensions 933 #define jpeg_calc_output_dimensions jCalcDimensions 934 #define jpeg_save_markers jSaveMarkers 935 #define jpeg_set_marker_processor jSetMarker 936 #define jpeg_read_coefficients jReadCoefs 937 #define jpeg_write_coefficients jWrtCoefs 938 #define jpeg_copy_critical_parameters jCopyCrit 939 #define jpeg_abort_compress jAbrtCompress 940 #define jpeg_abort_decompress jAbrtDecompress 941 #define jpeg_abort jAbort 942 #define jpeg_destroy jDestroy 943 #define jpeg_resync_to_restart jResyncRestart 944 #endif /* NEED_SHORT_EXTERNAL_NAMES */ 945 946 947 /* Default error-management setup */ 948 EXTERN(struct jpeg_error_mgr *) jpeg_std_error 949 JPP((struct jpeg_error_mgr * err)); 950 951 /* Initialization of JPEG compression objects. 952 * jpeg_create_compress() and jpeg_create_decompress() are the exported 953 * names that applications should call. These expand to calls on 954 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information 955 * passed for version mismatch checking. 956 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx. 957 */ 958 #define jpeg_create_compress(cinfo) \ 959 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \ 960 (size_t) sizeof(struct jpeg_compress_struct)) 961 #define jpeg_create_decompress(cinfo) \ 962 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \ 963 (size_t) sizeof(struct jpeg_decompress_struct)) 964 EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo, 965 int version, size_t structsize)); 966 EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo, 967 int version, size_t structsize)); 968 /* Destruction of JPEG compression objects */ 969 EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo)); 970 EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo)); 971 972 /* Standard data source and destination managers: stdio streams. */ 973 /* Caller is responsible for opening the file before and closing after. */ 974 EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile)); 975 EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile)); 976 977 /* Data source and destination managers: memory buffers. */ 978 EXTERN(void) jpeg_mem_dest JPP((j_compress_ptr cinfo, 979 unsigned char ** outbuffer, 980 unsigned long * outsize)); 981 EXTERN(void) jpeg_mem_src JPP((j_decompress_ptr cinfo, 982 const unsigned char * inbuffer, 983 unsigned long insize)); 984 985 /* Default parameter setup for compression */ 986 EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo)); 987 /* Compression parameter setup aids */ 988 EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo, 989 J_COLOR_SPACE colorspace)); 990 EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo)); 991 EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality, 992 boolean force_baseline)); 993 EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo, 994 int scale_factor, 995 boolean force_baseline)); 996 EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo, 997 boolean force_baseline)); 998 EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl, 999 const unsigned int *basic_table, 1000 int scale_factor, 1001 boolean force_baseline)); 1002 EXTERN(int) jpeg_quality_scaling JPP((int quality)); 1003 EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo)); 1004 EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo, 1005 boolean suppress)); 1006 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo)); 1007 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo)); 1008 1009 /* Main entry points for compression */ 1010 EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo, 1011 boolean write_all_tables)); 1012 EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo, 1013 JSAMPARRAY scanlines, 1014 JDIMENSION num_lines)); 1015 EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo)); 1016 1017 /* Precalculate JPEG dimensions for current compression parameters. */ 1018 EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo)); 1019 1020 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */ 1021 EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo, 1022 JSAMPIMAGE data, 1023 JDIMENSION num_lines)); 1024 1025 /* Write a special marker. See libjpeg.txt concerning safe usage. */ 1026 EXTERN(void) jpeg_write_marker 1027 JPP((j_compress_ptr cinfo, int marker, 1028 const JOCTET * dataptr, unsigned int datalen)); 1029 /* Same, but piecemeal. */ 1030 EXTERN(void) jpeg_write_m_header 1031 JPP((j_compress_ptr cinfo, int marker, unsigned int datalen)); 1032 EXTERN(void) jpeg_write_m_byte 1033 JPP((j_compress_ptr cinfo, int val)); 1034 1035 /* Alternate compression function: just write an abbreviated table file */ 1036 EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo)); 1037 1038 /* Decompression startup: read start of JPEG datastream to see what's there */ 1039 EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo, 1040 boolean require_image)); 1041 /* Return value is one of: */ 1042 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */ 1043 #define JPEG_HEADER_OK 1 /* Found valid image datastream */ 1044 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */ 1045 /* If you pass require_image = TRUE (normal case), you need not check for 1046 * a TABLES_ONLY return code; an abbreviated file will cause an error exit. 1047 * JPEG_SUSPENDED is only possible if you use a data source module that can 1048 * give a suspension return (the stdio source module doesn't). 1049 */ 1050 1051 /* Main entry points for decompression */ 1052 EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo)); 1053 EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo, 1054 JSAMPARRAY scanlines, 1055 JDIMENSION max_lines)); 1056 EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo)); 1057 1058 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */ 1059 EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo, 1060 JSAMPIMAGE data, 1061 JDIMENSION max_lines)); 1062 1063 /* Additional entry points for buffered-image mode. */ 1064 EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo)); 1065 EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo, 1066 int scan_number)); 1067 EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo)); 1068 EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo)); 1069 EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo)); 1070 EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo)); 1071 /* Return value is one of: */ 1072 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */ 1073 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */ 1074 #define JPEG_REACHED_EOI 2 /* Reached end of image */ 1075 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */ 1076 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */ 1077 1078 /* Precalculate output dimensions for current decompression parameters. */ 1079 EXTERN(void) jpeg_core_output_dimensions JPP((j_decompress_ptr cinfo)); 1080 EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo)); 1081 1082 /* Control saving of COM and APPn markers into marker_list. */ 1083 EXTERN(void) jpeg_save_markers 1084 JPP((j_decompress_ptr cinfo, int marker_code, 1085 unsigned int length_limit)); 1086 1087 /* Install a special processing method for COM or APPn markers. */ 1088 EXTERN(void) jpeg_set_marker_processor 1089 JPP((j_decompress_ptr cinfo, int marker_code, 1090 jpeg_marker_parser_method routine)); 1091 1092 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */ 1093 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo)); 1094 EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo, 1095 jvirt_barray_ptr * coef_arrays)); 1096 EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo, 1097 j_compress_ptr dstinfo)); 1098 1099 /* If you choose to abort compression or decompression before completing 1100 * jpeg_finish_(de)compress, then you need to clean up to release memory, 1101 * temporary files, etc. You can just call jpeg_destroy_(de)compress 1102 * if you're done with the JPEG object, but if you want to clean it up and 1103 * reuse it, call this: 1104 */ 1105 EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo)); 1106 EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo)); 1107 1108 /* Generic versions of jpeg_abort and jpeg_destroy that work on either 1109 * flavor of JPEG object. These may be more convenient in some places. 1110 */ 1111 EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo)); 1112 EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo)); 1113 1114 /* Default restart-marker-resync procedure for use by data source modules */ 1115 EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo, 1116 int desired)); 1117 1118 1119 /* These marker codes are exported since applications and data source modules 1120 * are likely to want to use them. 1121 */ 1122 1123 #define JPEG_RST0 0xD0 /* RST0 marker code */ 1124 #define JPEG_EOI 0xD9 /* EOI marker code */ 1125 #define JPEG_APP0 0xE0 /* APP0 marker code */ 1126 #define JPEG_COM 0xFE /* COM marker code */ 1127 1128 1129 /* If we have a brain-damaged compiler that emits warnings (or worse, errors) 1130 * for structure definitions that are never filled in, keep it quiet by 1131 * supplying dummy definitions for the various substructures. 1132 */ 1133 1134 #ifdef INCOMPLETE_TYPES_BROKEN 1135 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */ 1136 struct jvirt_sarray_control { long dummy; }; 1137 struct jvirt_barray_control { long dummy; }; 1138 struct jpeg_comp_master { long dummy; }; 1139 struct jpeg_c_main_controller { long dummy; }; 1140 struct jpeg_c_prep_controller { long dummy; }; 1141 struct jpeg_c_coef_controller { long dummy; }; 1142 struct jpeg_marker_writer { long dummy; }; 1143 struct jpeg_color_converter { long dummy; }; 1144 struct jpeg_downsampler { long dummy; }; 1145 struct jpeg_forward_dct { long dummy; }; 1146 struct jpeg_entropy_encoder { long dummy; }; 1147 struct jpeg_decomp_master { long dummy; }; 1148 struct jpeg_d_main_controller { long dummy; }; 1149 struct jpeg_d_coef_controller { long dummy; }; 1150 struct jpeg_d_post_controller { long dummy; }; 1151 struct jpeg_input_controller { long dummy; }; 1152 struct jpeg_marker_reader { long dummy; }; 1153 struct jpeg_entropy_decoder { long dummy; }; 1154 struct jpeg_inverse_dct { long dummy; }; 1155 struct jpeg_upsampler { long dummy; }; 1156 struct jpeg_color_deconverter { long dummy; }; 1157 struct jpeg_color_quantizer { long dummy; }; 1158 #endif /* JPEG_INTERNALS */ 1159 #endif /* INCOMPLETE_TYPES_BROKEN */ 1160 1161 1162 /* 1163 * The JPEG library modules define JPEG_INTERNALS before including this file. 1164 * The internal structure declarations are read only when that is true. 1165 * Applications using the library should not include jpegint.h, but may wish 1166 * to include jerror.h. 1167 */ 1168 1169 #ifdef JPEG_INTERNALS 1170 #include "jpegint.h" /* fetch private declarations */ 1171 #include "jerror.h" /* fetch error codes too */ 1172 #endif 1173 1174 #ifdef __cplusplus 1175 #ifndef DONT_USE_EXTERN_C 1176 } 1177 #endif 1178 #endif 1179 1180 #endif /* JPEGLIB_H */ 1181