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.ijg 11 * file. 12 * 13 * This file defines the application interface for the JPEG library. 14 * Most applications using the library need only include this file, 15 * and perhaps jerror.h if they want to know the exact error codes. 16 */ 17 18 #ifndef JPEGLIB_H 19 #define JPEGLIB_H 20 21 /* 22 * First we include the configuration files that record how this 23 * installation of the JPEG library is set up. jconfig.h can be 24 * generated automatically for many systems. jmorecfg.h contains 25 * manual configuration options that most people need not worry about. 26 */ 27 28 #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */ 29 #include "jconfig.h" /* widely used configuration options */ 30 #endif 31 #include "jmorecfg.h" /* seldom changed options */ 32 33 34 #ifdef __cplusplus 35 #ifndef DONT_USE_EXTERN_C 36 extern "C" { 37 #endif 38 #endif 39 40 41 /* Various constants determining the sizes of things. 42 * All of these are specified by the JPEG standard, so don't change them 43 * if you want to be compatible. 44 */ 45 46 #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */ 47 #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */ 48 #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */ 49 #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */ 50 #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */ 51 #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */ 52 #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */ 53 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard; 54 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU. 55 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU 56 * to handle it. We even let you do this from the jconfig.h file. However, 57 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe 58 * sometimes emits noncompliant files doesn't mean you should too. 59 */ 60 #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */ 61 #ifndef D_MAX_BLOCKS_IN_MCU 62 #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */ 63 #endif 64 65 66 /* Data structures for images (arrays of samples and of DCT coefficients). 67 */ 68 69 typedef JSAMPLE *JSAMPROW; /* ptr to one image row of pixel samples. */ 70 typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */ 71 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */ 72 73 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */ 74 typedef JBLOCK *JBLOCKROW; /* pointer to one row of coefficient blocks */ 75 typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */ 76 typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */ 77 78 typedef JCOEF *JCOEFPTR; /* useful in a couple of places */ 79 80 81 /* Types for JPEG compression parameters and working tables. */ 82 83 84 /* DCT coefficient quantization tables. */ 85 86 typedef struct { 87 /* This array gives the coefficient quantizers in natural array order 88 * (not the zigzag order in which they are stored in a JPEG DQT marker). 89 * CAUTION: IJG versions prior to v6a kept this array in zigzag order. 90 */ 91 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */ 92 /* This field is used only during compression. It's initialized FALSE when 93 * the table is created, and set TRUE when it's been output to the file. 94 * You could suppress output of a table by setting this to TRUE. 95 * (See jpeg_suppress_tables for an example.) 96 */ 97 boolean sent_table; /* TRUE when table has been output */ 98 } JQUANT_TBL; 99 100 101 /* Huffman coding tables. */ 102 103 typedef struct { 104 /* These two fields directly represent the contents of a JPEG DHT marker */ 105 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */ 106 /* length k bits; bits[0] is unused */ 107 UINT8 huffval[256]; /* The symbols, in order of incr code length */ 108 /* This field is used only during compression. It's initialized FALSE when 109 * the table is created, and set TRUE when it's been output to the file. 110 * You could suppress output of a table by setting this to TRUE. 111 * (See jpeg_suppress_tables for an example.) 112 */ 113 boolean sent_table; /* TRUE when table has been output */ 114 } JHUFF_TBL; 115 116 117 /* Basic info about one component (color channel). */ 118 119 typedef struct { 120 /* These values are fixed over the whole image. */ 121 /* For compression, they must be supplied by parameter setup; */ 122 /* for decompression, they are read from the SOF marker. */ 123 int component_id; /* identifier for this component (0..255) */ 124 int component_index; /* its index in SOF or cinfo->comp_info[] */ 125 int h_samp_factor; /* horizontal sampling factor (1..4) */ 126 int v_samp_factor; /* vertical sampling factor (1..4) */ 127 int quant_tbl_no; /* quantization table selector (0..3) */ 128 /* These values may vary between scans. */ 129 /* For compression, they must be supplied by parameter setup; */ 130 /* for decompression, they are read from the SOS marker. */ 131 /* The decompressor output side may not use these variables. */ 132 int dc_tbl_no; /* DC entropy table selector (0..3) */ 133 int ac_tbl_no; /* AC entropy table selector (0..3) */ 134 135 /* Remaining fields should be treated as private by applications. */ 136 137 /* These values are computed during compression or decompression startup: */ 138 /* Component's size in DCT blocks. 139 * Any dummy blocks added to complete an MCU are not counted; therefore 140 * these values do not depend on whether a scan is interleaved or not. 141 */ 142 JDIMENSION width_in_blocks; 143 JDIMENSION height_in_blocks; 144 /* Size of a DCT block in samples. Always DCTSIZE for compression. 145 * For decompression this is the size of the output from one DCT block, 146 * reflecting any scaling we choose to apply during the IDCT step. 147 * Values from 1 to 16 are supported. 148 * Note that different components may receive different IDCT scalings. 149 */ 150 #if JPEG_LIB_VERSION >= 70 151 int DCT_h_scaled_size; 152 int DCT_v_scaled_size; 153 #else 154 int DCT_scaled_size; 155 #endif 156 /* The downsampled dimensions are the component's actual, unpadded number 157 * of samples at the main buffer (preprocessing/compression interface), thus 158 * downsampled_width = ceil(image_width * Hi/Hmax) 159 * and similarly for height. For decompression, IDCT scaling is included, so 160 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]scaled_size/DCTSIZE) 161 */ 162 JDIMENSION downsampled_width; /* actual width in samples */ 163 JDIMENSION downsampled_height; /* actual height in samples */ 164 /* This flag is used only for decompression. In cases where some of the 165 * components will be ignored (eg grayscale output from YCbCr image), 166 * we can skip most computations for the unused components. 167 */ 168 boolean component_needed; /* do we need the value of this component? */ 169 170 /* These values are computed before starting a scan of the component. */ 171 /* The decompressor output side may not use these variables. */ 172 int MCU_width; /* number of blocks per MCU, horizontally */ 173 int MCU_height; /* number of blocks per MCU, vertically */ 174 int MCU_blocks; /* MCU_width * MCU_height */ 175 int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_[h_]scaled_size */ 176 int last_col_width; /* # of non-dummy blocks across in last MCU */ 177 int last_row_height; /* # of non-dummy blocks down in last MCU */ 178 179 /* Saved quantization table for component; NULL if none yet saved. 180 * See jdinput.c comments about the need for this information. 181 * This field is currently used only for decompression. 182 */ 183 JQUANT_TBL *quant_table; 184 185 /* Private per-component storage for DCT or IDCT subsystem. */ 186 void *dct_table; 187 } jpeg_component_info; 188 189 190 /* The script for encoding a multiple-scan file is an array of these: */ 191 192 typedef struct { 193 int comps_in_scan; /* number of components encoded in this scan */ 194 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */ 195 int Ss, Se; /* progressive JPEG spectral selection parms */ 196 int Ah, Al; /* progressive JPEG successive approx. parms */ 197 } jpeg_scan_info; 198 199 /* The decompressor can save APPn and COM markers in a list of these: */ 200 201 typedef struct jpeg_marker_struct *jpeg_saved_marker_ptr; 202 203 struct jpeg_marker_struct { 204 jpeg_saved_marker_ptr next; /* next in list, or NULL */ 205 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */ 206 unsigned int original_length; /* # bytes of data in the file */ 207 unsigned int data_length; /* # bytes of data saved at data[] */ 208 JOCTET *data; /* the data contained in the marker */ 209 /* the marker length word is not counted in data_length or original_length */ 210 }; 211 212 /* Known color spaces. */ 213 214 #define JCS_EXTENSIONS 1 215 #define JCS_ALPHA_EXTENSIONS 1 216 217 typedef enum { 218 JCS_UNKNOWN, /* error/unspecified */ 219 JCS_GRAYSCALE, /* monochrome */ 220 JCS_RGB, /* red/green/blue as specified by the RGB_RED, 221 RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros */ 222 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */ 223 JCS_CMYK, /* C/M/Y/K */ 224 JCS_YCCK, /* Y/Cb/Cr/K */ 225 JCS_EXT_RGB, /* red/green/blue */ 226 JCS_EXT_RGBX, /* red/green/blue/x */ 227 JCS_EXT_BGR, /* blue/green/red */ 228 JCS_EXT_BGRX, /* blue/green/red/x */ 229 JCS_EXT_XBGR, /* x/blue/green/red */ 230 JCS_EXT_XRGB, /* x/red/green/blue */ 231 /* When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX, JCS_EXT_XBGR, 232 or JCS_EXT_XRGB during decompression, the X byte is undefined, and in 233 order to ensure the best performance, libjpeg-turbo can set that byte to 234 whatever value it wishes. Use the following colorspace constants to 235 ensure that the X byte is set to 0xFF, so that it can be interpreted as an 236 opaque alpha channel. */ 237 JCS_EXT_RGBA, /* red/green/blue/alpha */ 238 JCS_EXT_BGRA, /* blue/green/red/alpha */ 239 JCS_EXT_ABGR, /* alpha/blue/green/red */ 240 JCS_EXT_ARGB, /* alpha/red/green/blue */ 241 JCS_RGB565 /* 5-bit red/6-bit green/5-bit blue */ 242 } J_COLOR_SPACE; 243 244 /* DCT/IDCT algorithm options. */ 245 246 typedef enum { 247 JDCT_ISLOW, /* slow but accurate integer algorithm */ 248 JDCT_IFAST, /* faster, less accurate integer method */ 249 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */ 250 } J_DCT_METHOD; 251 252 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */ 253 #define JDCT_DEFAULT JDCT_ISLOW 254 #endif 255 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */ 256 #define JDCT_FASTEST JDCT_IFAST 257 #endif 258 259 /* Dithering options for decompression. */ 260 261 typedef enum { 262 JDITHER_NONE, /* no dithering */ 263 JDITHER_ORDERED, /* simple ordered dither */ 264 JDITHER_FS /* Floyd-Steinberg error diffusion dither */ 265 } J_DITHER_MODE; 266 267 268 /* Common fields between JPEG compression and decompression master structs. */ 269 270 #define jpeg_common_fields \ 271 struct jpeg_error_mgr *err; /* Error handler module */\ 272 struct jpeg_memory_mgr *mem; /* Memory manager module */\ 273 struct jpeg_progress_mgr *progress; /* Progress monitor, or NULL if none */\ 274 void *client_data; /* Available for use by application */\ 275 boolean is_decompressor; /* So common code can tell which is which */\ 276 int global_state /* For checking call sequence validity */ 277 278 /* Routines that are to be used by both halves of the library are declared 279 * to receive a pointer to this structure. There are no actual instances of 280 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct. 281 */ 282 struct jpeg_common_struct { 283 jpeg_common_fields; /* Fields common to both master struct types */ 284 /* Additional fields follow in an actual jpeg_compress_struct or 285 * jpeg_decompress_struct. All three structs must agree on these 286 * initial fields! (This would be a lot cleaner in C++.) 287 */ 288 }; 289 290 typedef struct jpeg_common_struct *j_common_ptr; 291 typedef struct jpeg_compress_struct *j_compress_ptr; 292 typedef struct jpeg_decompress_struct *j_decompress_ptr; 293 294 295 /* Master record for a compression instance */ 296 297 struct jpeg_compress_struct { 298 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */ 299 300 /* Destination for compressed data */ 301 struct jpeg_destination_mgr *dest; 302 303 /* Description of source image --- these fields must be filled in by 304 * outer application before starting compression. in_color_space must 305 * be correct before you can even call jpeg_set_defaults(). 306 */ 307 308 JDIMENSION image_width; /* input image width */ 309 JDIMENSION image_height; /* input image height */ 310 int input_components; /* # of color components in input image */ 311 J_COLOR_SPACE in_color_space; /* colorspace of input image */ 312 313 double input_gamma; /* image gamma of input image */ 314 315 /* Compression parameters --- these fields must be set before calling 316 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to 317 * initialize everything to reasonable defaults, then changing anything 318 * the application specifically wants to change. That way you won't get 319 * burnt when new parameters are added. Also note that there are several 320 * helper routines to simplify changing parameters. 321 */ 322 323 #if JPEG_LIB_VERSION >= 70 324 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 325 326 JDIMENSION jpeg_width; /* scaled JPEG image width */ 327 JDIMENSION jpeg_height; /* scaled JPEG image height */ 328 /* Dimensions of actual JPEG image that will be written to file, 329 * derived from input dimensions by scaling factors above. 330 * These fields are computed by jpeg_start_compress(). 331 * You can also use jpeg_calc_jpeg_dimensions() to determine these values 332 * in advance of calling jpeg_start_compress(). 333 */ 334 #endif 335 336 int data_precision; /* bits of precision in image data */ 337 338 int num_components; /* # of color components in JPEG image */ 339 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 340 341 jpeg_component_info *comp_info; 342 /* comp_info[i] describes component that appears i'th in SOF */ 343 344 JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS]; 345 #if JPEG_LIB_VERSION >= 70 346 int q_scale_factor[NUM_QUANT_TBLS]; 347 #endif 348 /* ptrs to coefficient quantization tables, or NULL if not defined, 349 * and corresponding scale factors (percentage, initialized 100). 350 */ 351 352 JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 353 JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 354 /* ptrs to Huffman coding tables, or NULL if not defined */ 355 356 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 357 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 358 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 359 360 int num_scans; /* # of entries in scan_info array */ 361 const jpeg_scan_info *scan_info; /* script for multi-scan file, or NULL */ 362 /* The default value of scan_info is NULL, which causes a single-scan 363 * sequential JPEG file to be emitted. To create a multi-scan file, 364 * set num_scans and scan_info to point to an array of scan definitions. 365 */ 366 367 boolean raw_data_in; /* TRUE=caller supplies downsampled data */ 368 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 369 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */ 370 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 371 #if JPEG_LIB_VERSION >= 70 372 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */ 373 #endif 374 int smoothing_factor; /* 1..100, or 0 for no input smoothing */ 375 J_DCT_METHOD dct_method; /* DCT algorithm selector */ 376 377 /* The restart interval can be specified in absolute MCUs by setting 378 * restart_interval, or in MCU rows by setting restart_in_rows 379 * (in which case the correct restart_interval will be figured 380 * for each scan). 381 */ 382 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */ 383 int restart_in_rows; /* if > 0, MCU rows per restart interval */ 384 385 /* Parameters controlling emission of special markers. */ 386 387 boolean write_JFIF_header; /* should a JFIF marker be written? */ 388 UINT8 JFIF_major_version; /* What to write for the JFIF version number */ 389 UINT8 JFIF_minor_version; 390 /* These three values are not used by the JPEG code, merely copied */ 391 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */ 392 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */ 393 /* ratio is defined by X_density/Y_density even when density_unit=0. */ 394 UINT8 density_unit; /* JFIF code for pixel size units */ 395 UINT16 X_density; /* Horizontal pixel density */ 396 UINT16 Y_density; /* Vertical pixel density */ 397 boolean write_Adobe_marker; /* should an Adobe marker be written? */ 398 399 /* State variable: index of next scanline to be written to 400 * jpeg_write_scanlines(). Application may use this to control its 401 * processing loop, e.g., "while (next_scanline < image_height)". 402 */ 403 404 JDIMENSION next_scanline; /* 0 .. image_height-1 */ 405 406 /* Remaining fields are known throughout compressor, but generally 407 * should not be touched by a surrounding application. 408 */ 409 410 /* 411 * These fields are computed during compression startup 412 */ 413 boolean progressive_mode; /* TRUE if scan script uses progressive mode */ 414 int max_h_samp_factor; /* largest h_samp_factor */ 415 int max_v_samp_factor; /* largest v_samp_factor */ 416 417 #if JPEG_LIB_VERSION >= 70 418 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 419 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 420 #endif 421 422 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */ 423 /* The coefficient controller receives data in units of MCU rows as defined 424 * for fully interleaved scans (whether the JPEG file is interleaved or not). 425 * There are v_samp_factor * DCTSIZE sample rows of each component in an 426 * "iMCU" (interleaved MCU) row. 427 */ 428 429 /* 430 * These fields are valid during any one scan. 431 * They describe the components and MCUs actually appearing in the scan. 432 */ 433 int comps_in_scan; /* # of JPEG components in this scan */ 434 jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN]; 435 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 436 437 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 438 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 439 440 int blocks_in_MCU; /* # of DCT blocks per MCU */ 441 int MCU_membership[C_MAX_BLOCKS_IN_MCU]; 442 /* MCU_membership[i] is index in cur_comp_info of component owning */ 443 /* i'th block in an MCU */ 444 445 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 446 447 #if JPEG_LIB_VERSION >= 80 448 int block_size; /* the basic DCT block size: 1..16 */ 449 const int *natural_order; /* natural-order position array */ 450 int lim_Se; /* min( Se, DCTSIZE2-1 ) */ 451 #endif 452 453 /* 454 * Links to compression subobjects (methods and private variables of modules) 455 */ 456 struct jpeg_comp_master *master; 457 struct jpeg_c_main_controller *main; 458 struct jpeg_c_prep_controller *prep; 459 struct jpeg_c_coef_controller *coef; 460 struct jpeg_marker_writer *marker; 461 struct jpeg_color_converter *cconvert; 462 struct jpeg_downsampler *downsample; 463 struct jpeg_forward_dct *fdct; 464 struct jpeg_entropy_encoder *entropy; 465 jpeg_scan_info *script_space; /* workspace for jpeg_simple_progression */ 466 int script_space_size; 467 }; 468 469 470 /* Master record for a decompression instance */ 471 472 struct jpeg_decompress_struct { 473 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */ 474 475 /* Source of compressed data */ 476 struct jpeg_source_mgr *src; 477 478 /* Basic description of image --- filled in by jpeg_read_header(). */ 479 /* Application may inspect these values to decide how to process image. */ 480 481 JDIMENSION image_width; /* nominal image width (from SOF marker) */ 482 JDIMENSION image_height; /* nominal image height */ 483 int num_components; /* # of color components in JPEG image */ 484 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 485 486 /* Decompression processing parameters --- these fields must be set before 487 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes 488 * them to default values. 489 */ 490 491 J_COLOR_SPACE out_color_space; /* colorspace for output */ 492 493 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 494 495 double output_gamma; /* image gamma wanted in output */ 496 497 boolean buffered_image; /* TRUE=multiple output passes */ 498 boolean raw_data_out; /* TRUE=downsampled data wanted */ 499 500 J_DCT_METHOD dct_method; /* IDCT algorithm selector */ 501 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */ 502 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */ 503 504 boolean quantize_colors; /* TRUE=colormapped output wanted */ 505 /* the following are ignored if not quantize_colors: */ 506 J_DITHER_MODE dither_mode; /* type of color dithering to use */ 507 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */ 508 int desired_number_of_colors; /* max # colors to use in created colormap */ 509 /* these are significant only in buffered-image mode: */ 510 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */ 511 boolean enable_external_quant;/* enable future use of external colormap */ 512 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */ 513 514 /* Description of actual output image that will be returned to application. 515 * These fields are computed by jpeg_start_decompress(). 516 * You can also use jpeg_calc_output_dimensions() to determine these values 517 * in advance of calling jpeg_start_decompress(). 518 */ 519 520 JDIMENSION output_width; /* scaled image width */ 521 JDIMENSION output_height; /* scaled image height */ 522 int out_color_components; /* # of color components in out_color_space */ 523 int output_components; /* # of color components returned */ 524 /* output_components is 1 (a colormap index) when quantizing colors; 525 * otherwise it equals out_color_components. 526 */ 527 int rec_outbuf_height; /* min recommended height of scanline buffer */ 528 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows 529 * high, space and time will be wasted due to unnecessary data copying. 530 * Usually rec_outbuf_height will be 1 or 2, at most 4. 531 */ 532 533 /* When quantizing colors, the output colormap is described by these fields. 534 * The application can supply a colormap by setting colormap non-NULL before 535 * calling jpeg_start_decompress; otherwise a colormap is created during 536 * jpeg_start_decompress or jpeg_start_output. 537 * The map has out_color_components rows and actual_number_of_colors columns. 538 */ 539 int actual_number_of_colors; /* number of entries in use */ 540 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */ 541 542 /* State variables: these variables indicate the progress of decompression. 543 * The application may examine these but must not modify them. 544 */ 545 546 /* Row index of next scanline to be read from jpeg_read_scanlines(). 547 * Application may use this to control its processing loop, e.g., 548 * "while (output_scanline < output_height)". 549 */ 550 JDIMENSION output_scanline; /* 0 .. output_height-1 */ 551 552 /* Current input scan number and number of iMCU rows completed in scan. 553 * These indicate the progress of the decompressor input side. 554 */ 555 int input_scan_number; /* Number of SOS markers seen so far */ 556 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */ 557 558 /* The "output scan number" is the notional scan being displayed by the 559 * output side. The decompressor will not allow output scan/row number 560 * to get ahead of input scan/row, but it can fall arbitrarily far behind. 561 */ 562 int output_scan_number; /* Nominal scan number being displayed */ 563 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */ 564 565 /* Current progression status. coef_bits[c][i] indicates the precision 566 * with which component c's DCT coefficient i (in zigzag order) is known. 567 * It is -1 when no data has yet been received, otherwise it is the point 568 * transform (shift) value for the most recent scan of the coefficient 569 * (thus, 0 at completion of the progression). 570 * This pointer is NULL when reading a non-progressive file. 571 */ 572 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */ 573 574 /* Internal JPEG parameters --- the application usually need not look at 575 * these fields. Note that the decompressor output side may not use 576 * any parameters that can change between scans. 577 */ 578 579 /* Quantization and Huffman tables are carried forward across input 580 * datastreams when processing abbreviated JPEG datastreams. 581 */ 582 583 JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS]; 584 /* ptrs to coefficient quantization tables, or NULL if not defined */ 585 586 JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 587 JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 588 /* ptrs to Huffman coding tables, or NULL if not defined */ 589 590 /* These parameters are never carried across datastreams, since they 591 * are given in SOF/SOS markers or defined to be reset by SOI. 592 */ 593 594 int data_precision; /* bits of precision in image data */ 595 596 jpeg_component_info *comp_info; 597 /* comp_info[i] describes component that appears i'th in SOF */ 598 599 #if JPEG_LIB_VERSION >= 80 600 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */ 601 #endif 602 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */ 603 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 604 605 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 606 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 607 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 608 609 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */ 610 611 /* These fields record data obtained from optional markers recognized by 612 * the JPEG library. 613 */ 614 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */ 615 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */ 616 UINT8 JFIF_major_version; /* JFIF version number */ 617 UINT8 JFIF_minor_version; 618 UINT8 density_unit; /* JFIF code for pixel size units */ 619 UINT16 X_density; /* Horizontal pixel density */ 620 UINT16 Y_density; /* Vertical pixel density */ 621 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */ 622 UINT8 Adobe_transform; /* Color transform code from Adobe marker */ 623 624 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 625 626 /* Aside from the specific data retained from APPn markers known to the 627 * library, the uninterpreted contents of any or all APPn and COM markers 628 * can be saved in a list for examination by the application. 629 */ 630 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */ 631 632 /* Remaining fields are known throughout decompressor, but generally 633 * should not be touched by a surrounding application. 634 */ 635 636 /* 637 * These fields are computed during decompression startup 638 */ 639 int max_h_samp_factor; /* largest h_samp_factor */ 640 int max_v_samp_factor; /* largest v_samp_factor */ 641 642 #if JPEG_LIB_VERSION >= 70 643 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 644 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 645 #else 646 int min_DCT_scaled_size; /* smallest DCT_scaled_size of any component */ 647 #endif 648 649 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */ 650 /* The coefficient controller's input and output progress is measured in 651 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows 652 * in fully interleaved JPEG scans, but are used whether the scan is 653 * interleaved or not. We define an iMCU row as v_samp_factor DCT block 654 * rows of each component. Therefore, the IDCT output contains 655 * v_samp_factor*DCT_[v_]scaled_size sample rows of a component per iMCU row. 656 */ 657 658 JSAMPLE *sample_range_limit; /* table for fast range-limiting */ 659 660 /* 661 * These fields are valid during any one scan. 662 * They describe the components and MCUs actually appearing in the scan. 663 * Note that the decompressor output side must not use these fields. 664 */ 665 int comps_in_scan; /* # of JPEG components in this scan */ 666 jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN]; 667 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 668 669 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 670 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 671 672 int blocks_in_MCU; /* # of DCT blocks per MCU */ 673 int MCU_membership[D_MAX_BLOCKS_IN_MCU]; 674 /* MCU_membership[i] is index in cur_comp_info of component owning */ 675 /* i'th block in an MCU */ 676 677 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 678 679 #if JPEG_LIB_VERSION >= 80 680 /* These fields are derived from Se of first SOS marker. 681 */ 682 int block_size; /* the basic DCT block size: 1..16 */ 683 const int *natural_order; /* natural-order position array for entropy decode */ 684 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */ 685 #endif 686 687 /* This field is shared between entropy decoder and marker parser. 688 * It is either zero or the code of a JPEG marker that has been 689 * read from the data source, but has not yet been processed. 690 */ 691 int unread_marker; 692 693 /* 694 * Links to decompression subobjects (methods, private variables of modules) 695 */ 696 struct jpeg_decomp_master *master; 697 struct jpeg_d_main_controller *main; 698 struct jpeg_d_coef_controller *coef; 699 struct jpeg_d_post_controller *post; 700 struct jpeg_input_controller *inputctl; 701 struct jpeg_marker_reader *marker; 702 struct jpeg_entropy_decoder *entropy; 703 struct jpeg_inverse_dct *idct; 704 struct jpeg_upsampler *upsample; 705 struct jpeg_color_deconverter *cconvert; 706 struct jpeg_color_quantizer *cquantize; 707 }; 708 709 710 /* "Object" declarations for JPEG modules that may be supplied or called 711 * directly by the surrounding application. 712 * As with all objects in the JPEG library, these structs only define the 713 * publicly visible methods and state variables of a module. Additional 714 * private fields may exist after the public ones. 715 */ 716 717 718 /* Error handler object */ 719 720 struct jpeg_error_mgr { 721 /* Error exit handler: does not return to caller */ 722 void (*error_exit) (j_common_ptr cinfo); 723 /* Conditionally emit a trace or warning message */ 724 void (*emit_message) (j_common_ptr cinfo, int msg_level); 725 /* Routine that actually outputs a trace or error message */ 726 void (*output_message) (j_common_ptr cinfo); 727 /* Format a message string for the most recent JPEG error or message */ 728 void (*format_message) (j_common_ptr cinfo, char *buffer); 729 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */ 730 /* Reset error state variables at start of a new image */ 731 void (*reset_error_mgr) (j_common_ptr cinfo); 732 733 /* The message ID code and any parameters are saved here. 734 * A message can have one string parameter or up to 8 int parameters. 735 */ 736 int msg_code; 737 #define JMSG_STR_PARM_MAX 80 738 union { 739 int i[8]; 740 char s[JMSG_STR_PARM_MAX]; 741 } msg_parm; 742 743 /* Standard state variables for error facility */ 744 745 int trace_level; /* max msg_level that will be displayed */ 746 747 /* For recoverable corrupt-data errors, we emit a warning message, 748 * but keep going unless emit_message chooses to abort. emit_message 749 * should count warnings in num_warnings. The surrounding application 750 * can check for bad data by seeing if num_warnings is nonzero at the 751 * end of processing. 752 */ 753 long num_warnings; /* number of corrupt-data warnings */ 754 755 /* These fields point to the table(s) of error message strings. 756 * An application can change the table pointer to switch to a different 757 * message list (typically, to change the language in which errors are 758 * reported). Some applications may wish to add additional error codes 759 * that will be handled by the JPEG library error mechanism; the second 760 * table pointer is used for this purpose. 761 * 762 * First table includes all errors generated by JPEG library itself. 763 * Error code 0 is reserved for a "no such error string" message. 764 */ 765 const char * const *jpeg_message_table; /* Library errors */ 766 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */ 767 /* Second table can be added by application (see cjpeg/djpeg for example). 768 * It contains strings numbered first_addon_message..last_addon_message. 769 */ 770 const char * const *addon_message_table; /* Non-library errors */ 771 int first_addon_message; /* code for first string in addon table */ 772 int last_addon_message; /* code for last string in addon table */ 773 }; 774 775 776 /* Progress monitor object */ 777 778 struct jpeg_progress_mgr { 779 void (*progress_monitor) (j_common_ptr cinfo); 780 781 long pass_counter; /* work units completed in this pass */ 782 long pass_limit; /* total number of work units in this pass */ 783 int completed_passes; /* passes completed so far */ 784 int total_passes; /* total number of passes expected */ 785 }; 786 787 788 /* Data destination object for compression */ 789 790 struct jpeg_destination_mgr { 791 JOCTET *next_output_byte; /* => next byte to write in buffer */ 792 size_t free_in_buffer; /* # of byte spaces remaining in buffer */ 793 794 void (*init_destination) (j_compress_ptr cinfo); 795 boolean (*empty_output_buffer) (j_compress_ptr cinfo); 796 void (*term_destination) (j_compress_ptr cinfo); 797 }; 798 799 800 /* Data source object for decompression */ 801 802 struct jpeg_source_mgr { 803 const JOCTET *next_input_byte; /* => next byte to read from buffer */ 804 size_t bytes_in_buffer; /* # of bytes remaining in buffer */ 805 806 void (*init_source) (j_decompress_ptr cinfo); 807 boolean (*fill_input_buffer) (j_decompress_ptr cinfo); 808 void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes); 809 boolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired); 810 void (*term_source) (j_decompress_ptr cinfo); 811 }; 812 813 814 /* Memory manager object. 815 * Allocates "small" objects (a few K total), "large" objects (tens of K), 816 * and "really big" objects (virtual arrays with backing store if needed). 817 * The memory manager does not allow individual objects to be freed; rather, 818 * each created object is assigned to a pool, and whole pools can be freed 819 * at once. This is faster and more convenient than remembering exactly what 820 * to free, especially where malloc()/free() are not too speedy. 821 * NB: alloc routines never return NULL. They exit to error_exit if not 822 * successful. 823 */ 824 825 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */ 826 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */ 827 #define JPOOL_NUMPOOLS 2 828 829 typedef struct jvirt_sarray_control *jvirt_sarray_ptr; 830 typedef struct jvirt_barray_control *jvirt_barray_ptr; 831 832 833 struct jpeg_memory_mgr { 834 /* Method pointers */ 835 void *(*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject); 836 void *(*alloc_large) (j_common_ptr cinfo, int pool_id, 837 size_t sizeofobject); 838 JSAMPARRAY (*alloc_sarray) (j_common_ptr cinfo, int pool_id, 839 JDIMENSION samplesperrow, JDIMENSION numrows); 840 JBLOCKARRAY (*alloc_barray) (j_common_ptr cinfo, int pool_id, 841 JDIMENSION blocksperrow, JDIMENSION numrows); 842 jvirt_sarray_ptr (*request_virt_sarray) (j_common_ptr cinfo, int pool_id, 843 boolean pre_zero, 844 JDIMENSION samplesperrow, 845 JDIMENSION numrows, 846 JDIMENSION maxaccess); 847 jvirt_barray_ptr (*request_virt_barray) (j_common_ptr cinfo, int pool_id, 848 boolean pre_zero, 849 JDIMENSION blocksperrow, 850 JDIMENSION numrows, 851 JDIMENSION maxaccess); 852 void (*realize_virt_arrays) (j_common_ptr cinfo); 853 JSAMPARRAY (*access_virt_sarray) (j_common_ptr cinfo, jvirt_sarray_ptr ptr, 854 JDIMENSION start_row, JDIMENSION num_rows, 855 boolean writable); 856 JBLOCKARRAY (*access_virt_barray) (j_common_ptr cinfo, jvirt_barray_ptr ptr, 857 JDIMENSION start_row, JDIMENSION num_rows, 858 boolean writable); 859 void (*free_pool) (j_common_ptr cinfo, int pool_id); 860 void (*self_destruct) (j_common_ptr cinfo); 861 862 /* Limit on memory allocation for this JPEG object. (Note that this is 863 * merely advisory, not a guaranteed maximum; it only affects the space 864 * used for virtual-array buffers.) May be changed by outer application 865 * after creating the JPEG object. 866 */ 867 long max_memory_to_use; 868 869 /* Maximum allocation request accepted by alloc_large. */ 870 long max_alloc_chunk; 871 }; 872 873 874 /* Routine signature for application-supplied marker processing methods. 875 * Need not pass marker code since it is stored in cinfo->unread_marker. 876 */ 877 typedef boolean (*jpeg_marker_parser_method) (j_decompress_ptr cinfo); 878 879 880 /* Originally, this macro was used as a way of defining function prototypes 881 * for both modern compilers as well as older compilers that did not support 882 * prototype parameters. libjpeg-turbo has never supported these older, 883 * non-ANSI compilers, but the macro is still included because there is some 884 * software out there that uses it. 885 */ 886 887 #define JPP(arglist) arglist 888 889 890 /* Default error-management setup */ 891 EXTERN(struct jpeg_error_mgr *) jpeg_std_error (struct jpeg_error_mgr *err); 892 893 /* Initialization of JPEG compression objects. 894 * jpeg_create_compress() and jpeg_create_decompress() are the exported 895 * names that applications should call. These expand to calls on 896 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information 897 * passed for version mismatch checking. 898 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx. 899 */ 900 #define jpeg_create_compress(cinfo) \ 901 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \ 902 (size_t) sizeof(struct jpeg_compress_struct)) 903 #define jpeg_create_decompress(cinfo) \ 904 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \ 905 (size_t) sizeof(struct jpeg_decompress_struct)) 906 EXTERN(void) jpeg_CreateCompress (j_compress_ptr cinfo, int version, 907 size_t structsize); 908 EXTERN(void) jpeg_CreateDecompress (j_decompress_ptr cinfo, int version, 909 size_t structsize); 910 /* Destruction of JPEG compression objects */ 911 EXTERN(void) jpeg_destroy_compress (j_compress_ptr cinfo); 912 EXTERN(void) jpeg_destroy_decompress (j_decompress_ptr cinfo); 913 914 /* Standard data source and destination managers: stdio streams. */ 915 /* Caller is responsible for opening the file before and closing after. */ 916 EXTERN(void) jpeg_stdio_dest (j_compress_ptr cinfo, FILE *outfile); 917 EXTERN(void) jpeg_stdio_src (j_decompress_ptr cinfo, FILE *infile); 918 919 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED) 920 /* Data source and destination managers: memory buffers. */ 921 EXTERN(void) jpeg_mem_dest (j_compress_ptr cinfo, unsigned char **outbuffer, 922 unsigned long *outsize); 923 EXTERN(void) jpeg_mem_src (j_decompress_ptr cinfo, 924 const unsigned char *inbuffer, 925 unsigned long insize); 926 #endif 927 928 /* Default parameter setup for compression */ 929 EXTERN(void) jpeg_set_defaults (j_compress_ptr cinfo); 930 /* Compression parameter setup aids */ 931 EXTERN(void) jpeg_set_colorspace (j_compress_ptr cinfo, 932 J_COLOR_SPACE colorspace); 933 EXTERN(void) jpeg_default_colorspace (j_compress_ptr cinfo); 934 EXTERN(void) jpeg_set_quality (j_compress_ptr cinfo, int quality, 935 boolean force_baseline); 936 EXTERN(void) jpeg_set_linear_quality (j_compress_ptr cinfo, int scale_factor, 937 boolean force_baseline); 938 #if JPEG_LIB_VERSION >= 70 939 EXTERN(void) jpeg_default_qtables (j_compress_ptr cinfo, 940 boolean force_baseline); 941 #endif 942 EXTERN(void) jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl, 943 const unsigned int *basic_table, 944 int scale_factor, boolean force_baseline); 945 EXTERN(int) jpeg_quality_scaling (int quality); 946 EXTERN(void) jpeg_simple_progression (j_compress_ptr cinfo); 947 EXTERN(void) jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress); 948 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table (j_common_ptr cinfo); 949 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table (j_common_ptr cinfo); 950 951 /* Main entry points for compression */ 952 EXTERN(void) jpeg_start_compress (j_compress_ptr cinfo, 953 boolean write_all_tables); 954 EXTERN(JDIMENSION) jpeg_write_scanlines (j_compress_ptr cinfo, 955 JSAMPARRAY scanlines, 956 JDIMENSION num_lines); 957 EXTERN(void) jpeg_finish_compress (j_compress_ptr cinfo); 958 959 #if JPEG_LIB_VERSION >= 70 960 /* Precalculate JPEG dimensions for current compression parameters. */ 961 EXTERN(void) jpeg_calc_jpeg_dimensions (j_compress_ptr cinfo); 962 #endif 963 964 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */ 965 EXTERN(JDIMENSION) jpeg_write_raw_data (j_compress_ptr cinfo, JSAMPIMAGE data, 966 JDIMENSION num_lines); 967 968 /* Write a special marker. See libjpeg.txt concerning safe usage. */ 969 EXTERN(void) jpeg_write_marker (j_compress_ptr cinfo, int marker, 970 const JOCTET *dataptr, unsigned int datalen); 971 /* Same, but piecemeal. */ 972 EXTERN(void) jpeg_write_m_header (j_compress_ptr cinfo, int marker, 973 unsigned int datalen); 974 EXTERN(void) jpeg_write_m_byte (j_compress_ptr cinfo, int val); 975 976 /* Alternate compression function: just write an abbreviated table file */ 977 EXTERN(void) jpeg_write_tables (j_compress_ptr cinfo); 978 979 /* Decompression startup: read start of JPEG datastream to see what's there */ 980 EXTERN(int) jpeg_read_header (j_decompress_ptr cinfo, boolean require_image); 981 /* Return value is one of: */ 982 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */ 983 #define JPEG_HEADER_OK 1 /* Found valid image datastream */ 984 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */ 985 /* If you pass require_image = TRUE (normal case), you need not check for 986 * a TABLES_ONLY return code; an abbreviated file will cause an error exit. 987 * JPEG_SUSPENDED is only possible if you use a data source module that can 988 * give a suspension return (the stdio source module doesn't). 989 */ 990 991 /* Main entry points for decompression */ 992 EXTERN(boolean) jpeg_start_decompress (j_decompress_ptr cinfo); 993 EXTERN(JDIMENSION) jpeg_read_scanlines (j_decompress_ptr cinfo, 994 JSAMPARRAY scanlines, 995 JDIMENSION max_lines); 996 EXTERN(JDIMENSION) jpeg_skip_scanlines (j_decompress_ptr cinfo, 997 JDIMENSION num_lines); 998 EXTERN(void) jpeg_crop_scanline (j_decompress_ptr cinfo, JDIMENSION *xoffset, 999 JDIMENSION *width); 1000 EXTERN(boolean) jpeg_finish_decompress (j_decompress_ptr cinfo); 1001 1002 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */ 1003 EXTERN(JDIMENSION) jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data, 1004 JDIMENSION max_lines); 1005 1006 /* Additional entry points for buffered-image mode. */ 1007 EXTERN(boolean) jpeg_has_multiple_scans (j_decompress_ptr cinfo); 1008 EXTERN(boolean) jpeg_start_output (j_decompress_ptr cinfo, int scan_number); 1009 EXTERN(boolean) jpeg_finish_output (j_decompress_ptr cinfo); 1010 EXTERN(boolean) jpeg_input_complete (j_decompress_ptr cinfo); 1011 EXTERN(void) jpeg_new_colormap (j_decompress_ptr cinfo); 1012 EXTERN(int) jpeg_consume_input (j_decompress_ptr cinfo); 1013 /* Return value is one of: */ 1014 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */ 1015 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */ 1016 #define JPEG_REACHED_EOI 2 /* Reached end of image */ 1017 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */ 1018 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */ 1019 1020 /* Precalculate output dimensions for current decompression parameters. */ 1021 #if JPEG_LIB_VERSION >= 80 1022 EXTERN(void) jpeg_core_output_dimensions (j_decompress_ptr cinfo); 1023 #endif 1024 EXTERN(void) jpeg_calc_output_dimensions (j_decompress_ptr cinfo); 1025 1026 /* Control saving of COM and APPn markers into marker_list. */ 1027 EXTERN(void) jpeg_save_markers (j_decompress_ptr cinfo, int marker_code, 1028 unsigned int length_limit); 1029 1030 /* Install a special processing method for COM or APPn markers. */ 1031 EXTERN(void) jpeg_set_marker_processor (j_decompress_ptr cinfo, 1032 int marker_code, 1033 jpeg_marker_parser_method routine); 1034 1035 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */ 1036 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients (j_decompress_ptr cinfo); 1037 EXTERN(void) jpeg_write_coefficients (j_compress_ptr cinfo, 1038 jvirt_barray_ptr *coef_arrays); 1039 EXTERN(void) jpeg_copy_critical_parameters (j_decompress_ptr srcinfo, 1040 j_compress_ptr dstinfo); 1041 1042 /* If you choose to abort compression or decompression before completing 1043 * jpeg_finish_(de)compress, then you need to clean up to release memory, 1044 * temporary files, etc. You can just call jpeg_destroy_(de)compress 1045 * if you're done with the JPEG object, but if you want to clean it up and 1046 * reuse it, call this: 1047 */ 1048 EXTERN(void) jpeg_abort_compress (j_compress_ptr cinfo); 1049 EXTERN(void) jpeg_abort_decompress (j_decompress_ptr cinfo); 1050 1051 /* Generic versions of jpeg_abort and jpeg_destroy that work on either 1052 * flavor of JPEG object. These may be more convenient in some places. 1053 */ 1054 EXTERN(void) jpeg_abort (j_common_ptr cinfo); 1055 EXTERN(void) jpeg_destroy (j_common_ptr cinfo); 1056 1057 /* Default restart-marker-resync procedure for use by data source modules */ 1058 EXTERN(boolean) jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired); 1059 1060 1061 /* These marker codes are exported since applications and data source modules 1062 * are likely to want to use them. 1063 */ 1064 1065 #define JPEG_RST0 0xD0 /* RST0 marker code */ 1066 #define JPEG_EOI 0xD9 /* EOI marker code */ 1067 #define JPEG_APP0 0xE0 /* APP0 marker code */ 1068 #define JPEG_COM 0xFE /* COM marker code */ 1069 1070 1071 /* If we have a brain-damaged compiler that emits warnings (or worse, errors) 1072 * for structure definitions that are never filled in, keep it quiet by 1073 * supplying dummy definitions for the various substructures. 1074 */ 1075 1076 #ifdef INCOMPLETE_TYPES_BROKEN 1077 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */ 1078 struct jvirt_sarray_control { long dummy; }; 1079 struct jvirt_barray_control { long dummy; }; 1080 struct jpeg_comp_master { long dummy; }; 1081 struct jpeg_c_main_controller { long dummy; }; 1082 struct jpeg_c_prep_controller { long dummy; }; 1083 struct jpeg_c_coef_controller { long dummy; }; 1084 struct jpeg_marker_writer { long dummy; }; 1085 struct jpeg_color_converter { long dummy; }; 1086 struct jpeg_downsampler { long dummy; }; 1087 struct jpeg_forward_dct { long dummy; }; 1088 struct jpeg_entropy_encoder { long dummy; }; 1089 struct jpeg_decomp_master { long dummy; }; 1090 struct jpeg_d_main_controller { long dummy; }; 1091 struct jpeg_d_coef_controller { long dummy; }; 1092 struct jpeg_d_post_controller { long dummy; }; 1093 struct jpeg_input_controller { long dummy; }; 1094 struct jpeg_marker_reader { long dummy; }; 1095 struct jpeg_entropy_decoder { long dummy; }; 1096 struct jpeg_inverse_dct { long dummy; }; 1097 struct jpeg_upsampler { long dummy; }; 1098 struct jpeg_color_deconverter { long dummy; }; 1099 struct jpeg_color_quantizer { long dummy; }; 1100 #endif /* JPEG_INTERNALS */ 1101 #endif /* INCOMPLETE_TYPES_BROKEN */ 1102 1103 1104 /* 1105 * The JPEG library modules define JPEG_INTERNALS before including this file. 1106 * The internal structure declarations are read only when that is true. 1107 * Applications using the library should not include jpegint.h, but may wish 1108 * to include jerror.h. 1109 */ 1110 1111 #ifdef JPEG_INTERNALS 1112 #include "jpegint.h" /* fetch private declarations */ 1113 #include "jerror.h" /* fetch error codes too */ 1114 #endif 1115 1116 #ifdef __cplusplus 1117 #ifndef DONT_USE_EXTERN_C 1118 } 1119 #endif 1120 #endif 1121 1122 #endif /* JPEGLIB_H */ 1123
