1 /* 2 * jpeglib.h 3 * 4 * This file was part of the Independent JPEG Group's software: 5 * Copyright (C) 1991-1998, Thomas G. Lane. 6 * Modified 2002-2009 by Guido Vollbeding. 7 * libjpeg-turbo Modifications: 8 * Copyright (C) 2009-2011, 2013-2014, 2016, D. R. Commander. 9 * Copyright (C) 2015, Google, Inc. 10 * For conditions of distribution and use, see the accompanying README file. 11 * 12 * This file defines the application interface for the JPEG library. 13 * Most applications using the library need only include this file, 14 * and perhaps jerror.h if they want to know the exact error codes. 15 */ 16 17 #ifndef JPEGLIB_H 18 #define JPEGLIB_H 19 20 /* 21 * First we include the configuration files that record how this 22 * installation of the JPEG library is set up. jconfig.h can be 23 * generated automatically for many systems. jmorecfg.h contains 24 * manual configuration options that most people need not worry about. 25 */ 26 27 #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */ 28 #include "jconfig.h" /* widely used configuration options */ 29 #endif 30 #include "jmorecfg.h" /* seldom changed options */ 31 32 33 #ifdef __cplusplus 34 #ifndef DONT_USE_EXTERN_C 35 extern "C" { 36 #endif 37 #endif 38 39 40 /* Various constants determining the sizes of things. 41 * All of these are specified by the JPEG standard, so don't change them 42 * if you want to be compatible. 43 */ 44 45 #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */ 46 #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */ 47 #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */ 48 #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */ 49 #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */ 50 #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */ 51 #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */ 52 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard; 53 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU. 54 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU 55 * to handle it. We even let you do this from the jconfig.h file. However, 56 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe 57 * sometimes emits noncompliant files doesn't mean you should too. 58 */ 59 #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */ 60 #ifndef D_MAX_BLOCKS_IN_MCU 61 #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */ 62 #endif 63 64 65 /* Data structures for images (arrays of samples and of DCT coefficients). 66 */ 67 68 typedef JSAMPLE *JSAMPROW; /* ptr to one image row of pixel samples. */ 69 typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */ 70 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */ 71 72 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */ 73 typedef JBLOCK *JBLOCKROW; /* pointer to one row of coefficient blocks */ 74 typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */ 75 typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */ 76 77 typedef JCOEF *JCOEFPTR; /* useful in a couple of places */ 78 79 80 /* Types for JPEG compression parameters and working tables. */ 81 82 83 /* DCT coefficient quantization tables. */ 84 85 typedef struct { 86 /* This array gives the coefficient quantizers in natural array order 87 * (not the zigzag order in which they are stored in a JPEG DQT marker). 88 * CAUTION: IJG versions prior to v6a kept this array in zigzag order. 89 */ 90 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */ 91 /* This field is used only during compression. It's initialized FALSE when 92 * the table is created, and set TRUE when it's been output to the file. 93 * You could suppress output of a table by setting this to TRUE. 94 * (See jpeg_suppress_tables for an example.) 95 */ 96 boolean sent_table; /* TRUE when table has been output */ 97 } JQUANT_TBL; 98 99 100 /* Huffman coding tables. */ 101 102 typedef struct { 103 /* These two fields directly represent the contents of a JPEG DHT marker */ 104 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */ 105 /* length k bits; bits[0] is unused */ 106 UINT8 huffval[256]; /* The symbols, in order of incr code length */ 107 /* This field is used only during compression. It's initialized FALSE when 108 * the table is created, and set TRUE when it's been output to the file. 109 * You could suppress output of a table by setting this to TRUE. 110 * (See jpeg_suppress_tables for an example.) 111 */ 112 boolean sent_table; /* TRUE when table has been output */ 113 } JHUFF_TBL; 114 115 116 /* Basic info about one component (color channel). */ 117 118 typedef struct { 119 /* These values are fixed over the whole image. */ 120 /* For compression, they must be supplied by parameter setup; */ 121 /* for decompression, they are read from the SOF marker. */ 122 int component_id; /* identifier for this component (0..255) */ 123 int component_index; /* its index in SOF or cinfo->comp_info[] */ 124 int h_samp_factor; /* horizontal sampling factor (1..4) */ 125 int v_samp_factor; /* vertical sampling factor (1..4) */ 126 int quant_tbl_no; /* quantization table selector (0..3) */ 127 /* These values may vary between scans. */ 128 /* For compression, they must be supplied by parameter setup; */ 129 /* for decompression, they are read from the SOS marker. */ 130 /* The decompressor output side may not use these variables. */ 131 int dc_tbl_no; /* DC entropy table selector (0..3) */ 132 int ac_tbl_no; /* AC entropy table selector (0..3) */ 133 134 /* Remaining fields should be treated as private by applications. */ 135 136 /* These values are computed during compression or decompression startup: */ 137 /* Component's size in DCT blocks. 138 * Any dummy blocks added to complete an MCU are not counted; therefore 139 * these values do not depend on whether a scan is interleaved or not. 140 */ 141 JDIMENSION width_in_blocks; 142 JDIMENSION height_in_blocks; 143 /* Size of a DCT block in samples. Always DCTSIZE for compression. 144 * For decompression this is the size of the output from one DCT block, 145 * reflecting any scaling we choose to apply during the IDCT step. 146 * Values from 1 to 16 are supported. 147 * Note that different components may receive different IDCT scalings. 148 */ 149 #if JPEG_LIB_VERSION >= 70 150 int DCT_h_scaled_size; 151 int DCT_v_scaled_size; 152 #else 153 int DCT_scaled_size; 154 #endif 155 /* The downsampled dimensions are the component's actual, unpadded number 156 * of samples at the main buffer (preprocessing/compression interface), thus 157 * downsampled_width = ceil(image_width * Hi/Hmax) 158 * and similarly for height. For decompression, IDCT scaling is included, so 159 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]scaled_size/DCTSIZE) 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 * 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 * 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 #define JCS_EXTENSIONS 1 214 #define JCS_ALPHA_EXTENSIONS 1 215 216 typedef enum { 217 JCS_UNKNOWN, /* error/unspecified */ 218 JCS_GRAYSCALE, /* monochrome */ 219 JCS_RGB, /* red/green/blue as specified by the RGB_RED, 220 RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros */ 221 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */ 222 JCS_CMYK, /* C/M/Y/K */ 223 JCS_YCCK, /* Y/Cb/Cr/K */ 224 JCS_EXT_RGB, /* red/green/blue */ 225 JCS_EXT_RGBX, /* red/green/blue/x */ 226 JCS_EXT_BGR, /* blue/green/red */ 227 JCS_EXT_BGRX, /* blue/green/red/x */ 228 JCS_EXT_XBGR, /* x/blue/green/red */ 229 JCS_EXT_XRGB, /* x/red/green/blue */ 230 /* When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX, JCS_EXT_XBGR, 231 or JCS_EXT_XRGB during decompression, the X byte is undefined, and in 232 order to ensure the best performance, libjpeg-turbo can set that byte to 233 whatever value it wishes. Use the following colorspace constants to 234 ensure that the X byte is set to 0xFF, so that it can be interpreted as an 235 opaque alpha channel. */ 236 JCS_EXT_RGBA, /* red/green/blue/alpha */ 237 JCS_EXT_BGRA, /* blue/green/red/alpha */ 238 JCS_EXT_ABGR, /* alpha/blue/green/red */ 239 JCS_EXT_ARGB, /* alpha/red/green/blue */ 240 JCS_RGB565 /* 5-bit red/6-bit green/5-bit blue */ 241 } J_COLOR_SPACE; 242 243 /* DCT/IDCT algorithm options. */ 244 245 typedef enum { 246 JDCT_ISLOW, /* slow but accurate integer algorithm */ 247 JDCT_IFAST, /* faster, less accurate integer method */ 248 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */ 249 } J_DCT_METHOD; 250 251 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */ 252 #define JDCT_DEFAULT JDCT_ISLOW 253 #endif 254 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */ 255 #define JDCT_FASTEST JDCT_IFAST 256 #endif 257 258 /* Dithering options for decompression. */ 259 260 typedef enum { 261 JDITHER_NONE, /* no dithering */ 262 JDITHER_ORDERED, /* simple ordered dither */ 263 JDITHER_FS /* Floyd-Steinberg error diffusion dither */ 264 } J_DITHER_MODE; 265 266 267 /* Common fields between JPEG compression and decompression master structs. */ 268 269 #define jpeg_common_fields \ 270 struct jpeg_error_mgr * err; /* Error handler module */\ 271 struct jpeg_memory_mgr * mem; /* Memory manager module */\ 272 struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\ 273 void * client_data; /* Available for use by application */\ 274 boolean is_decompressor; /* So common code can tell which is which */\ 275 int global_state /* For checking call sequence validity */ 276 277 /* Routines that are to be used by both halves of the library are declared 278 * to receive a pointer to this structure. There are no actual instances of 279 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct. 280 */ 281 struct jpeg_common_struct { 282 jpeg_common_fields; /* Fields common to both master struct types */ 283 /* Additional fields follow in an actual jpeg_compress_struct or 284 * jpeg_decompress_struct. All three structs must agree on these 285 * initial fields! (This would be a lot cleaner in C++.) 286 */ 287 }; 288 289 typedef struct jpeg_common_struct * j_common_ptr; 290 typedef struct jpeg_compress_struct * j_compress_ptr; 291 typedef struct jpeg_decompress_struct * j_decompress_ptr; 292 293 294 /* Master record for a compression instance */ 295 296 struct jpeg_compress_struct { 297 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */ 298 299 /* Destination for compressed data */ 300 struct jpeg_destination_mgr * dest; 301 302 /* Description of source image --- these fields must be filled in by 303 * outer application before starting compression. in_color_space must 304 * be correct before you can even call jpeg_set_defaults(). 305 */ 306 307 JDIMENSION image_width; /* input image width */ 308 JDIMENSION image_height; /* input image height */ 309 int input_components; /* # of color components in input image */ 310 J_COLOR_SPACE in_color_space; /* colorspace of input image */ 311 312 double input_gamma; /* image gamma of input image */ 313 314 /* Compression parameters --- these fields must be set before calling 315 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to 316 * initialize everything to reasonable defaults, then changing anything 317 * the application specifically wants to change. That way you won't get 318 * burnt when new parameters are added. Also note that there are several 319 * helper routines to simplify changing parameters. 320 */ 321 322 #if JPEG_LIB_VERSION >= 70 323 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 324 325 JDIMENSION jpeg_width; /* scaled JPEG image width */ 326 JDIMENSION jpeg_height; /* scaled JPEG image height */ 327 /* Dimensions of actual JPEG image that will be written to file, 328 * derived from input dimensions by scaling factors above. 329 * These fields are computed by jpeg_start_compress(). 330 * You can also use jpeg_calc_jpeg_dimensions() to determine these values 331 * in advance of calling jpeg_start_compress(). 332 */ 333 #endif 334 335 int data_precision; /* bits of precision in image data */ 336 337 int num_components; /* # of color components in JPEG image */ 338 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 339 340 jpeg_component_info * comp_info; 341 /* comp_info[i] describes component that appears i'th in SOF */ 342 343 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 344 #if JPEG_LIB_VERSION >= 70 345 int q_scale_factor[NUM_QUANT_TBLS]; 346 #endif 347 /* ptrs to coefficient quantization tables, or NULL if not defined, 348 * and corresponding scale factors (percentage, initialized 100). 349 */ 350 351 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 352 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 353 /* ptrs to Huffman coding tables, or NULL if not defined */ 354 355 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 356 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 357 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 358 359 int num_scans; /* # of entries in scan_info array */ 360 const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */ 361 /* The default value of scan_info is NULL, which causes a single-scan 362 * sequential JPEG file to be emitted. To create a multi-scan file, 363 * set num_scans and scan_info to point to an array of scan definitions. 364 */ 365 366 boolean raw_data_in; /* TRUE=caller supplies downsampled data */ 367 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 368 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */ 369 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 370 #if JPEG_LIB_VERSION >= 70 371 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */ 372 #endif 373 int smoothing_factor; /* 1..100, or 0 for no input smoothing */ 374 J_DCT_METHOD dct_method; /* DCT algorithm selector */ 375 376 /* The restart interval can be specified in absolute MCUs by setting 377 * restart_interval, or in MCU rows by setting restart_in_rows 378 * (in which case the correct restart_interval will be figured 379 * for each scan). 380 */ 381 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */ 382 int restart_in_rows; /* if > 0, MCU rows per restart interval */ 383 384 /* Parameters controlling emission of special markers. */ 385 386 boolean write_JFIF_header; /* should a JFIF marker be written? */ 387 UINT8 JFIF_major_version; /* What to write for the JFIF version number */ 388 UINT8 JFIF_minor_version; 389 /* These three values are not used by the JPEG code, merely copied */ 390 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */ 391 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */ 392 /* ratio is defined by X_density/Y_density even when density_unit=0. */ 393 UINT8 density_unit; /* JFIF code for pixel size units */ 394 UINT16 X_density; /* Horizontal pixel density */ 395 UINT16 Y_density; /* Vertical pixel density */ 396 boolean write_Adobe_marker; /* should an Adobe marker be written? */ 397 398 /* State variable: index of next scanline to be written to 399 * jpeg_write_scanlines(). Application may use this to control its 400 * processing loop, e.g., "while (next_scanline < image_height)". 401 */ 402 403 JDIMENSION next_scanline; /* 0 .. image_height-1 */ 404 405 /* Remaining fields are known throughout compressor, but generally 406 * should not be touched by a surrounding application. 407 */ 408 409 /* 410 * These fields are computed during compression startup 411 */ 412 boolean progressive_mode; /* TRUE if scan script uses progressive mode */ 413 int max_h_samp_factor; /* largest h_samp_factor */ 414 int max_v_samp_factor; /* largest v_samp_factor */ 415 416 #if JPEG_LIB_VERSION >= 70 417 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 418 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 419 #endif 420 421 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */ 422 /* The coefficient controller receives data in units of MCU rows as defined 423 * for fully interleaved scans (whether the JPEG file is interleaved or not). 424 * There are v_samp_factor * DCTSIZE sample rows of each component in an 425 * "iMCU" (interleaved MCU) row. 426 */ 427 428 /* 429 * These fields are valid during any one scan. 430 * They describe the components and MCUs actually appearing in the scan. 431 */ 432 int comps_in_scan; /* # of JPEG components in this scan */ 433 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 434 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 435 436 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 437 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 438 439 int blocks_in_MCU; /* # of DCT blocks per MCU */ 440 int MCU_membership[C_MAX_BLOCKS_IN_MCU]; 441 /* MCU_membership[i] is index in cur_comp_info of component owning */ 442 /* i'th block in an MCU */ 443 444 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 445 446 #if JPEG_LIB_VERSION >= 80 447 int block_size; /* the basic DCT block size: 1..16 */ 448 const int * natural_order; /* natural-order position array */ 449 int lim_Se; /* min( Se, DCTSIZE2-1 ) */ 450 #endif 451 452 /* 453 * Links to compression subobjects (methods and private variables of modules) 454 */ 455 struct jpeg_comp_master * master; 456 struct jpeg_c_main_controller * main; 457 struct jpeg_c_prep_controller * prep; 458 struct jpeg_c_coef_controller * coef; 459 struct jpeg_marker_writer * marker; 460 struct jpeg_color_converter * cconvert; 461 struct jpeg_downsampler * downsample; 462 struct jpeg_forward_dct * fdct; 463 struct jpeg_entropy_encoder * entropy; 464 jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */ 465 int script_space_size; 466 }; 467 468 469 /* Master record for a decompression instance */ 470 471 struct jpeg_decompress_struct { 472 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */ 473 474 /* Source of compressed data */ 475 struct jpeg_source_mgr * src; 476 477 /* Basic description of image --- filled in by jpeg_read_header(). */ 478 /* Application may inspect these values to decide how to process image. */ 479 480 JDIMENSION image_width; /* nominal image width (from SOF marker) */ 481 JDIMENSION image_height; /* nominal image height */ 482 int num_components; /* # of color components in JPEG image */ 483 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 484 485 /* Decompression processing parameters --- these fields must be set before 486 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes 487 * them to default values. 488 */ 489 490 J_COLOR_SPACE out_color_space; /* colorspace for output */ 491 492 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 493 494 double output_gamma; /* image gamma wanted in output */ 495 496 boolean buffered_image; /* TRUE=multiple output passes */ 497 boolean raw_data_out; /* TRUE=downsampled data wanted */ 498 499 J_DCT_METHOD dct_method; /* IDCT algorithm selector */ 500 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */ 501 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */ 502 503 boolean quantize_colors; /* TRUE=colormapped output wanted */ 504 /* the following are ignored if not quantize_colors: */ 505 J_DITHER_MODE dither_mode; /* type of color dithering to use */ 506 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */ 507 int desired_number_of_colors; /* max # colors to use in created colormap */ 508 /* these are significant only in buffered-image mode: */ 509 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */ 510 boolean enable_external_quant;/* enable future use of external colormap */ 511 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */ 512 513 /* Description of actual output image that will be returned to application. 514 * These fields are computed by jpeg_start_decompress(). 515 * You can also use jpeg_calc_output_dimensions() to determine these values 516 * in advance of calling jpeg_start_decompress(). 517 */ 518 519 JDIMENSION output_width; /* scaled image width */ 520 JDIMENSION output_height; /* scaled image height */ 521 int out_color_components; /* # of color components in out_color_space */ 522 int output_components; /* # of color components returned */ 523 /* output_components is 1 (a colormap index) when quantizing colors; 524 * otherwise it equals out_color_components. 525 */ 526 int rec_outbuf_height; /* min recommended height of scanline buffer */ 527 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows 528 * high, space and time will be wasted due to unnecessary data copying. 529 * Usually rec_outbuf_height will be 1 or 2, at most 4. 530 */ 531 532 /* When quantizing colors, the output colormap is described by these fields. 533 * The application can supply a colormap by setting colormap non-NULL before 534 * calling jpeg_start_decompress; otherwise a colormap is created during 535 * jpeg_start_decompress or jpeg_start_output. 536 * The map has out_color_components rows and actual_number_of_colors columns. 537 */ 538 int actual_number_of_colors; /* number of entries in use */ 539 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */ 540 541 /* State variables: these variables indicate the progress of decompression. 542 * The application may examine these but must not modify them. 543 */ 544 545 /* Row index of next scanline to be read from jpeg_read_scanlines(). 546 * Application may use this to control its processing loop, e.g., 547 * "while (output_scanline < output_height)". 548 */ 549 JDIMENSION output_scanline; /* 0 .. output_height-1 */ 550 551 /* Current input scan number and number of iMCU rows completed in scan. 552 * These indicate the progress of the decompressor input side. 553 */ 554 int input_scan_number; /* Number of SOS markers seen so far */ 555 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */ 556 557 /* The "output scan number" is the notional scan being displayed by the 558 * output side. The decompressor will not allow output scan/row number 559 * to get ahead of input scan/row, but it can fall arbitrarily far behind. 560 */ 561 int output_scan_number; /* Nominal scan number being displayed */ 562 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */ 563 564 /* Current progression status. coef_bits[c][i] indicates the precision 565 * with which component c's DCT coefficient i (in zigzag order) is known. 566 * It is -1 when no data has yet been received, otherwise it is the point 567 * transform (shift) value for the most recent scan of the coefficient 568 * (thus, 0 at completion of the progression). 569 * This pointer is NULL when reading a non-progressive file. 570 */ 571 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */ 572 573 /* Internal JPEG parameters --- the application usually need not look at 574 * these fields. Note that the decompressor output side may not use 575 * any parameters that can change between scans. 576 */ 577 578 /* Quantization and Huffman tables are carried forward across input 579 * datastreams when processing abbreviated JPEG datastreams. 580 */ 581 582 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 583 /* ptrs to coefficient quantization tables, or NULL if not defined */ 584 585 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 586 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 587 /* ptrs to Huffman coding tables, or NULL if not defined */ 588 589 /* These parameters are never carried across datastreams, since they 590 * are given in SOF/SOS markers or defined to be reset by SOI. 591 */ 592 593 int data_precision; /* bits of precision in image data */ 594 595 jpeg_component_info * comp_info; 596 /* comp_info[i] describes component that appears i'th in SOF */ 597 598 #if JPEG_LIB_VERSION >= 80 599 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */ 600 #endif 601 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */ 602 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 603 604 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 605 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 606 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 607 608 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */ 609 610 /* These fields record data obtained from optional markers recognized by 611 * the JPEG library. 612 */ 613 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */ 614 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */ 615 UINT8 JFIF_major_version; /* JFIF version number */ 616 UINT8 JFIF_minor_version; 617 UINT8 density_unit; /* JFIF code for pixel size units */ 618 UINT16 X_density; /* Horizontal pixel density */ 619 UINT16 Y_density; /* Vertical pixel density */ 620 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */ 621 UINT8 Adobe_transform; /* Color transform code from Adobe marker */ 622 623 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 624 625 /* Aside from the specific data retained from APPn markers known to the 626 * library, the uninterpreted contents of any or all APPn and COM markers 627 * can be saved in a list for examination by the application. 628 */ 629 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */ 630 631 /* Remaining fields are known throughout decompressor, but generally 632 * should not be touched by a surrounding application. 633 */ 634 635 /* 636 * These fields are computed during decompression startup 637 */ 638 int max_h_samp_factor; /* largest h_samp_factor */ 639 int max_v_samp_factor; /* largest v_samp_factor */ 640 641 #if JPEG_LIB_VERSION >= 70 642 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 643 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 644 #else 645 int min_DCT_scaled_size; /* smallest DCT_scaled_size of any component */ 646 #endif 647 648 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */ 649 /* The coefficient controller's input and output progress is measured in 650 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows 651 * in fully interleaved JPEG scans, but are used whether the scan is 652 * interleaved or not. We define an iMCU row as v_samp_factor DCT block 653 * rows of each component. Therefore, the IDCT output contains 654 * v_samp_factor*DCT_[v_]scaled_size sample rows of a component per iMCU row. 655 */ 656 657 JSAMPLE * sample_range_limit; /* table for fast range-limiting */ 658 659 /* 660 * These fields are valid during any one scan. 661 * They describe the components and MCUs actually appearing in the scan. 662 * Note that the decompressor output side must not use these fields. 663 */ 664 int comps_in_scan; /* # of JPEG components in this scan */ 665 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 666 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 667 668 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 669 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 670 671 int blocks_in_MCU; /* # of DCT blocks per MCU */ 672 int MCU_membership[D_MAX_BLOCKS_IN_MCU]; 673 /* MCU_membership[i] is index in cur_comp_info of component owning */ 674 /* i'th block in an MCU */ 675 676 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 677 678 #if JPEG_LIB_VERSION >= 80 679 /* These fields are derived from Se of first SOS marker. 680 */ 681 int block_size; /* the basic DCT block size: 1..16 */ 682 const int * natural_order; /* natural-order position array for entropy decode */ 683 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */ 684 #endif 685 686 /* This field is shared between entropy decoder and marker parser. 687 * It is either zero or the code of a JPEG marker that has been 688 * read from the data source, but has not yet been processed. 689 */ 690 int unread_marker; 691 692 /* 693 * Links to decompression subobjects (methods, private variables of modules) 694 */ 695 struct jpeg_decomp_master * master; 696 struct jpeg_d_main_controller * main; 697 struct jpeg_d_coef_controller * coef; 698 struct jpeg_d_post_controller * post; 699 struct jpeg_input_controller * inputctl; 700 struct jpeg_marker_reader * marker; 701 struct jpeg_entropy_decoder * entropy; 702 struct jpeg_inverse_dct * idct; 703 struct jpeg_upsampler * upsample; 704 struct jpeg_color_deconverter * cconvert; 705 struct jpeg_color_quantizer * cquantize; 706 }; 707 708 709 /* "Object" declarations for JPEG modules that may be supplied or called 710 * directly by the surrounding application. 711 * As with all objects in the JPEG library, these structs only define the 712 * publicly visible methods and state variables of a module. Additional 713 * private fields may exist after the public ones. 714 */ 715 716 717 /* Error handler object */ 718 719 struct jpeg_error_mgr { 720 /* Error exit handler: does not return to caller */ 721 void (*error_exit) (j_common_ptr cinfo); 722 /* Conditionally emit a trace or warning message */ 723 void (*emit_message) (j_common_ptr cinfo, int msg_level); 724 /* Routine that actually outputs a trace or error message */ 725 void (*output_message) (j_common_ptr cinfo); 726 /* Format a message string for the most recent JPEG error or message */ 727 void (*format_message) (j_common_ptr cinfo, char * buffer); 728 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */ 729 /* Reset error state variables at start of a new image */ 730 void (*reset_error_mgr) (j_common_ptr cinfo); 731 732 /* The message ID code and any parameters are saved here. 733 * A message can have one string parameter or up to 8 int parameters. 734 */ 735 int msg_code; 736 #define JMSG_STR_PARM_MAX 80 737 union { 738 int i[8]; 739 char s[JMSG_STR_PARM_MAX]; 740 } msg_parm; 741 742 /* Standard state variables for error facility */ 743 744 int trace_level; /* max msg_level that will be displayed */ 745 746 /* For recoverable corrupt-data errors, we emit a warning message, 747 * but keep going unless emit_message chooses to abort. emit_message 748 * should count warnings in num_warnings. The surrounding application 749 * can check for bad data by seeing if num_warnings is nonzero at the 750 * end of processing. 751 */ 752 long num_warnings; /* number of corrupt-data warnings */ 753 754 /* These fields point to the table(s) of error message strings. 755 * An application can change the table pointer to switch to a different 756 * message list (typically, to change the language in which errors are 757 * reported). Some applications may wish to add additional error codes 758 * that will be handled by the JPEG library error mechanism; the second 759 * table pointer is used for this purpose. 760 * 761 * First table includes all errors generated by JPEG library itself. 762 * Error code 0 is reserved for a "no such error string" message. 763 */ 764 const char * const * jpeg_message_table; /* Library errors */ 765 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */ 766 /* Second table can be added by application (see cjpeg/djpeg for example). 767 * It contains strings numbered first_addon_message..last_addon_message. 768 */ 769 const char * const * addon_message_table; /* Non-library errors */ 770 int first_addon_message; /* code for first string in addon table */ 771 int last_addon_message; /* code for last string in addon table */ 772 }; 773 774 775 /* Progress monitor object */ 776 777 struct jpeg_progress_mgr { 778 void (*progress_monitor) (j_common_ptr cinfo); 779 780 long pass_counter; /* work units completed in this pass */ 781 long pass_limit; /* total number of work units in this pass */ 782 int completed_passes; /* passes completed so far */ 783 int total_passes; /* total number of passes expected */ 784 }; 785 786 787 /* Data destination object for compression */ 788 789 struct jpeg_destination_mgr { 790 JOCTET * next_output_byte; /* => next byte to write in buffer */ 791 size_t free_in_buffer; /* # of byte spaces remaining in buffer */ 792 793 void (*init_destination) (j_compress_ptr cinfo); 794 boolean (*empty_output_buffer) (j_compress_ptr cinfo); 795 void (*term_destination) (j_compress_ptr cinfo); 796 }; 797 798 799 /* Data source object for decompression */ 800 801 struct jpeg_source_mgr { 802 const JOCTET * next_input_byte; /* => next byte to read from buffer */ 803 size_t bytes_in_buffer; /* # of bytes remaining in buffer */ 804 805 void (*init_source) (j_decompress_ptr cinfo); 806 boolean (*fill_input_buffer) (j_decompress_ptr cinfo); 807 void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes); 808 boolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired); 809 void (*term_source) (j_decompress_ptr cinfo); 810 }; 811 812 813 /* Memory manager object. 814 * Allocates "small" objects (a few K total), "large" objects (tens of K), 815 * and "really big" objects (virtual arrays with backing store if needed). 816 * The memory manager does not allow individual objects to be freed; rather, 817 * each created object is assigned to a pool, and whole pools can be freed 818 * at once. This is faster and more convenient than remembering exactly what 819 * to free, especially where malloc()/free() are not too speedy. 820 * NB: alloc routines never return NULL. They exit to error_exit if not 821 * successful. 822 */ 823 824 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */ 825 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */ 826 #define JPOOL_NUMPOOLS 2 827 828 typedef struct jvirt_sarray_control * jvirt_sarray_ptr; 829 typedef struct jvirt_barray_control * jvirt_barray_ptr; 830 831 832 struct jpeg_memory_mgr { 833 /* Method pointers */ 834 void * (*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject); 835 void * (*alloc_large) (j_common_ptr cinfo, int pool_id, 836 size_t sizeofobject); 837 JSAMPARRAY (*alloc_sarray) (j_common_ptr cinfo, int pool_id, 838 JDIMENSION samplesperrow, JDIMENSION numrows); 839 JBLOCKARRAY (*alloc_barray) (j_common_ptr cinfo, int pool_id, 840 JDIMENSION blocksperrow, JDIMENSION numrows); 841 jvirt_sarray_ptr (*request_virt_sarray) (j_common_ptr cinfo, int pool_id, 842 boolean pre_zero, 843 JDIMENSION samplesperrow, 844 JDIMENSION numrows, 845 JDIMENSION maxaccess); 846 jvirt_barray_ptr (*request_virt_barray) (j_common_ptr cinfo, int pool_id, 847 boolean pre_zero, 848 JDIMENSION blocksperrow, 849 JDIMENSION numrows, 850 JDIMENSION maxaccess); 851 void (*realize_virt_arrays) (j_common_ptr cinfo); 852 JSAMPARRAY (*access_virt_sarray) (j_common_ptr cinfo, jvirt_sarray_ptr ptr, 853 JDIMENSION start_row, JDIMENSION num_rows, 854 boolean writable); 855 JBLOCKARRAY (*access_virt_barray) (j_common_ptr cinfo, jvirt_barray_ptr ptr, 856 JDIMENSION start_row, JDIMENSION num_rows, 857 boolean writable); 858 void (*free_pool) (j_common_ptr cinfo, int pool_id); 859 void (*self_destruct) (j_common_ptr cinfo); 860 861 /* Limit on memory allocation for this JPEG object. (Note that this is 862 * merely advisory, not a guaranteed maximum; it only affects the space 863 * used for virtual-array buffers.) May be changed by outer application 864 * after creating the JPEG object. 865 */ 866 long max_memory_to_use; 867 868 /* Maximum allocation request accepted by alloc_large. */ 869 long max_alloc_chunk; 870 }; 871 872 873 /* Routine signature for application-supplied marker processing methods. 874 * Need not pass marker code since it is stored in cinfo->unread_marker. 875 */ 876 typedef boolean (*jpeg_marker_parser_method) (j_decompress_ptr cinfo); 877 878 879 /* Originally, this macro was used as a way of defining function prototypes 880 * for both modern compilers as well as older compilers that did not support 881 * prototype parameters. libjpeg-turbo has never supported these older, 882 * non-ANSI compilers, but the macro is still included because there is some 883 * software out there that uses it. 884 */ 885 886 #define JPP(arglist) arglist 887 888 889 /* Default error-management setup */ 890 EXTERN(struct jpeg_error_mgr *) jpeg_std_error (struct jpeg_error_mgr * err); 891 892 /* Initialization of JPEG compression objects. 893 * jpeg_create_compress() and jpeg_create_decompress() are the exported 894 * names that applications should call. These expand to calls on 895 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information 896 * passed for version mismatch checking. 897 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx. 898 */ 899 #define jpeg_create_compress(cinfo) \ 900 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \ 901 (size_t) sizeof(struct jpeg_compress_struct)) 902 #define jpeg_create_decompress(cinfo) \ 903 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \ 904 (size_t) sizeof(struct jpeg_decompress_struct)) 905 EXTERN(void) jpeg_CreateCompress (j_compress_ptr cinfo, int version, 906 size_t structsize); 907 EXTERN(void) jpeg_CreateDecompress (j_decompress_ptr cinfo, int version, 908 size_t structsize); 909 /* Destruction of JPEG compression objects */ 910 EXTERN(void) jpeg_destroy_compress (j_compress_ptr cinfo); 911 EXTERN(void) jpeg_destroy_decompress (j_decompress_ptr cinfo); 912 913 /* Standard data source and destination managers: stdio streams. */ 914 /* Caller is responsible for opening the file before and closing after. */ 915 EXTERN(void) jpeg_stdio_dest (j_compress_ptr cinfo, FILE * outfile); 916 EXTERN(void) jpeg_stdio_src (j_decompress_ptr cinfo, FILE * infile); 917 918 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED) 919 /* Data source and destination managers: memory buffers. */ 920 EXTERN(void) jpeg_mem_dest (j_compress_ptr cinfo, unsigned char ** outbuffer, 921 unsigned long * outsize); 922 EXTERN(void) jpeg_mem_src (j_decompress_ptr cinfo, unsigned char * inbuffer, 923 unsigned long insize); 924 #endif 925 926 /* Default parameter setup for compression */ 927 EXTERN(void) jpeg_set_defaults (j_compress_ptr cinfo); 928 /* Compression parameter setup aids */ 929 EXTERN(void) jpeg_set_colorspace (j_compress_ptr cinfo, 930 J_COLOR_SPACE colorspace); 931 EXTERN(void) jpeg_default_colorspace (j_compress_ptr cinfo); 932 EXTERN(void) jpeg_set_quality (j_compress_ptr cinfo, int quality, 933 boolean force_baseline); 934 EXTERN(void) jpeg_set_linear_quality (j_compress_ptr cinfo, int scale_factor, 935 boolean force_baseline); 936 #if JPEG_LIB_VERSION >= 70 937 EXTERN(void) jpeg_default_qtables (j_compress_ptr cinfo, 938 boolean force_baseline); 939 #endif 940 EXTERN(void) jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl, 941 const unsigned int *basic_table, 942 int scale_factor, boolean force_baseline); 943 EXTERN(int) jpeg_quality_scaling (int quality); 944 EXTERN(void) jpeg_simple_progression (j_compress_ptr cinfo); 945 EXTERN(void) jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress); 946 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table (j_common_ptr cinfo); 947 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table (j_common_ptr cinfo); 948 949 /* Main entry points for compression */ 950 EXTERN(void) jpeg_start_compress (j_compress_ptr cinfo, 951 boolean write_all_tables); 952 EXTERN(JDIMENSION) jpeg_write_scanlines (j_compress_ptr cinfo, 953 JSAMPARRAY scanlines, 954 JDIMENSION num_lines); 955 EXTERN(void) jpeg_finish_compress (j_compress_ptr cinfo); 956 957 #if JPEG_LIB_VERSION >= 70 958 /* Precalculate JPEG dimensions for current compression parameters. */ 959 EXTERN(void) jpeg_calc_jpeg_dimensions (j_compress_ptr cinfo); 960 #endif 961 962 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */ 963 EXTERN(JDIMENSION) jpeg_write_raw_data (j_compress_ptr cinfo, JSAMPIMAGE data, 964 JDIMENSION num_lines); 965 966 /* Write a special marker. See libjpeg.txt concerning safe usage. */ 967 EXTERN(void) jpeg_write_marker (j_compress_ptr cinfo, int marker, 968 const JOCTET * dataptr, unsigned int datalen); 969 /* Same, but piecemeal. */ 970 EXTERN(void) jpeg_write_m_header (j_compress_ptr cinfo, int marker, 971 unsigned int datalen); 972 EXTERN(void) jpeg_write_m_byte (j_compress_ptr cinfo, int val); 973 974 /* Alternate compression function: just write an abbreviated table file */ 975 EXTERN(void) jpeg_write_tables (j_compress_ptr cinfo); 976 977 /* Decompression startup: read start of JPEG datastream to see what's there */ 978 EXTERN(int) jpeg_read_header (j_decompress_ptr cinfo, boolean require_image); 979 /* Return value is one of: */ 980 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */ 981 #define JPEG_HEADER_OK 1 /* Found valid image datastream */ 982 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */ 983 /* If you pass require_image = TRUE (normal case), you need not check for 984 * a TABLES_ONLY return code; an abbreviated file will cause an error exit. 985 * JPEG_SUSPENDED is only possible if you use a data source module that can 986 * give a suspension return (the stdio source module doesn't). 987 */ 988 989 /* Main entry points for decompression */ 990 EXTERN(boolean) jpeg_start_decompress (j_decompress_ptr cinfo); 991 EXTERN(JDIMENSION) jpeg_read_scanlines (j_decompress_ptr cinfo, 992 JSAMPARRAY scanlines, 993 JDIMENSION max_lines); 994 EXTERN(JDIMENSION) jpeg_skip_scanlines (j_decompress_ptr cinfo, 995 JDIMENSION num_lines); 996 EXTERN(void) jpeg_crop_scanline (j_decompress_ptr cinfo, JDIMENSION *xoffset, 997 JDIMENSION *width); 998 EXTERN(boolean) jpeg_finish_decompress (j_decompress_ptr cinfo); 999 1000 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */ 1001 EXTERN(JDIMENSION) jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data, 1002 JDIMENSION max_lines); 1003 1004 /* Additional entry points for buffered-image mode. */ 1005 EXTERN(boolean) jpeg_has_multiple_scans (j_decompress_ptr cinfo); 1006 EXTERN(boolean) jpeg_start_output (j_decompress_ptr cinfo, int scan_number); 1007 EXTERN(boolean) jpeg_finish_output (j_decompress_ptr cinfo); 1008 EXTERN(boolean) jpeg_input_complete (j_decompress_ptr cinfo); 1009 EXTERN(void) jpeg_new_colormap (j_decompress_ptr cinfo); 1010 EXTERN(int) jpeg_consume_input (j_decompress_ptr cinfo); 1011 /* Return value is one of: */ 1012 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */ 1013 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */ 1014 #define JPEG_REACHED_EOI 2 /* Reached end of image */ 1015 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */ 1016 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */ 1017 1018 /* Precalculate output dimensions for current decompression parameters. */ 1019 #if JPEG_LIB_VERSION >= 80 1020 EXTERN(void) jpeg_core_output_dimensions (j_decompress_ptr cinfo); 1021 #endif 1022 EXTERN(void) jpeg_calc_output_dimensions (j_decompress_ptr cinfo); 1023 1024 /* Control saving of COM and APPn markers into marker_list. */ 1025 EXTERN(void) jpeg_save_markers (j_decompress_ptr cinfo, int marker_code, 1026 unsigned int length_limit); 1027 1028 /* Install a special processing method for COM or APPn markers. */ 1029 EXTERN(void) jpeg_set_marker_processor (j_decompress_ptr cinfo, 1030 int marker_code, 1031 jpeg_marker_parser_method routine); 1032 1033 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */ 1034 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients (j_decompress_ptr cinfo); 1035 EXTERN(void) jpeg_write_coefficients (j_compress_ptr cinfo, 1036 jvirt_barray_ptr * coef_arrays); 1037 EXTERN(void) jpeg_copy_critical_parameters (j_decompress_ptr srcinfo, 1038 j_compress_ptr dstinfo); 1039 1040 /* If you choose to abort compression or decompression before completing 1041 * jpeg_finish_(de)compress, then you need to clean up to release memory, 1042 * temporary files, etc. You can just call jpeg_destroy_(de)compress 1043 * if you're done with the JPEG object, but if you want to clean it up and 1044 * reuse it, call this: 1045 */ 1046 EXTERN(void) jpeg_abort_compress (j_compress_ptr cinfo); 1047 EXTERN(void) jpeg_abort_decompress (j_decompress_ptr cinfo); 1048 1049 /* Generic versions of jpeg_abort and jpeg_destroy that work on either 1050 * flavor of JPEG object. These may be more convenient in some places. 1051 */ 1052 EXTERN(void) jpeg_abort (j_common_ptr cinfo); 1053 EXTERN(void) jpeg_destroy (j_common_ptr cinfo); 1054 1055 /* Default restart-marker-resync procedure for use by data source modules */ 1056 EXTERN(boolean) jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired); 1057 1058 1059 /* These marker codes are exported since applications and data source modules 1060 * are likely to want to use them. 1061 */ 1062 1063 #define JPEG_RST0 0xD0 /* RST0 marker code */ 1064 #define JPEG_EOI 0xD9 /* EOI marker code */ 1065 #define JPEG_APP0 0xE0 /* APP0 marker code */ 1066 #define JPEG_COM 0xFE /* COM marker code */ 1067 1068 1069 /* If we have a brain-damaged compiler that emits warnings (or worse, errors) 1070 * for structure definitions that are never filled in, keep it quiet by 1071 * supplying dummy definitions for the various substructures. 1072 */ 1073 1074 #ifdef INCOMPLETE_TYPES_BROKEN 1075 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */ 1076 struct jvirt_sarray_control { long dummy; }; 1077 struct jvirt_barray_control { long dummy; }; 1078 struct jpeg_comp_master { long dummy; }; 1079 struct jpeg_c_main_controller { long dummy; }; 1080 struct jpeg_c_prep_controller { long dummy; }; 1081 struct jpeg_c_coef_controller { long dummy; }; 1082 struct jpeg_marker_writer { long dummy; }; 1083 struct jpeg_color_converter { long dummy; }; 1084 struct jpeg_downsampler { long dummy; }; 1085 struct jpeg_forward_dct { long dummy; }; 1086 struct jpeg_entropy_encoder { long dummy; }; 1087 struct jpeg_decomp_master { long dummy; }; 1088 struct jpeg_d_main_controller { long dummy; }; 1089 struct jpeg_d_coef_controller { long dummy; }; 1090 struct jpeg_d_post_controller { long dummy; }; 1091 struct jpeg_input_controller { long dummy; }; 1092 struct jpeg_marker_reader { long dummy; }; 1093 struct jpeg_entropy_decoder { long dummy; }; 1094 struct jpeg_inverse_dct { long dummy; }; 1095 struct jpeg_upsampler { long dummy; }; 1096 struct jpeg_color_deconverter { long dummy; }; 1097 struct jpeg_color_quantizer { long dummy; }; 1098 #endif /* JPEG_INTERNALS */ 1099 #endif /* INCOMPLETE_TYPES_BROKEN */ 1100 1101 1102 /* 1103 * The JPEG library modules define JPEG_INTERNALS before including this file. 1104 * The internal structure declarations are read only when that is true. 1105 * Applications using the library should not include jpegint.h, but may wish 1106 * to include jerror.h. 1107 */ 1108 1109 #ifdef JPEG_INTERNALS 1110 #include "jpegint.h" /* fetch private declarations */ 1111 #include "jerror.h" /* fetch error codes too */ 1112 #endif 1113 1114 #ifdef __cplusplus 1115 #ifndef DONT_USE_EXTERN_C 1116 } 1117 #endif 1118 #endif 1119 1120 #endif /* JPEGLIB_H */ 1121