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 #include "vtk_jpeg_mangle.h" 29 30 #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */ 31 #include "jconfig.h" /* widely used configuration options */ 32 #endif 33 #ifndef JMORECFG_INCLUDED 34 #include "jmorecfg.h" /* seldom changed options */ 35 #endif 36 37 #ifdef __cplusplus 38 #ifndef DONT_USE_EXTERN_C 39 extern "C" { 40 #endif 41 #endif 42 43 44 /* Various constants determining the sizes of things. 45 * All of these are specified by the JPEG standard, so don't change them 46 * if you want to be compatible. 47 */ 48 49 #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */ 50 #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */ 51 #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */ 52 #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */ 53 #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */ 54 #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */ 55 #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */ 56 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard; 57 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU. 58 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU 59 * to handle it. We even let you do this from the jconfig.h file. However, 60 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe 61 * sometimes emits noncompliant files doesn't mean you should too. 62 */ 63 #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */ 64 #ifndef D_MAX_BLOCKS_IN_MCU 65 #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */ 66 #endif 67 68 69 /* Data structures for images (arrays of samples and of DCT coefficients). 70 */ 71 72 typedef JSAMPLE *JSAMPROW; /* ptr to one image row of pixel samples. */ 73 typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */ 74 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */ 75 76 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */ 77 typedef JBLOCK *JBLOCKROW; /* pointer to one row of coefficient blocks */ 78 typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */ 79 typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */ 80 81 typedef JCOEF *JCOEFPTR; /* useful in a couple of places */ 82 83 84 /* Types for JPEG compression parameters and working tables. */ 85 86 87 /* DCT coefficient quantization tables. */ 88 89 typedef struct { 90 /* This array gives the coefficient quantizers in natural array order 91 * (not the zigzag order in which they are stored in a JPEG DQT marker). 92 * CAUTION: IJG versions prior to v6a kept this array in zigzag order. 93 */ 94 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */ 95 /* This field is used only during compression. It's initialized FALSE when 96 * the table is created, and set TRUE when it's been output to the file. 97 * You could suppress output of a table by setting this to TRUE. 98 * (See jpeg_suppress_tables for an example.) 99 */ 100 boolean sent_table; /* TRUE when table has been output */ 101 } JQUANT_TBL; 102 103 104 /* Huffman coding tables. */ 105 106 typedef struct { 107 /* These two fields directly represent the contents of a JPEG DHT marker */ 108 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */ 109 /* length k bits; bits[0] is unused */ 110 UINT8 huffval[256]; /* The symbols, in order of incr code length */ 111 /* This field is used only during compression. It's initialized FALSE when 112 * the table is created, and set TRUE when it's been output to the file. 113 * You could suppress output of a table by setting this to TRUE. 114 * (See jpeg_suppress_tables for an example.) 115 */ 116 boolean sent_table; /* TRUE when table has been output */ 117 } JHUFF_TBL; 118 119 120 /* Basic info about one component (color channel). */ 121 122 typedef struct { 123 /* These values are fixed over the whole image. */ 124 /* For compression, they must be supplied by parameter setup; */ 125 /* for decompression, they are read from the SOF marker. */ 126 int component_id; /* identifier for this component (0..255) */ 127 int component_index; /* its index in SOF or cinfo->comp_info[] */ 128 int h_samp_factor; /* horizontal sampling factor (1..4) */ 129 int v_samp_factor; /* vertical sampling factor (1..4) */ 130 int quant_tbl_no; /* quantization table selector (0..3) */ 131 /* These values may vary between scans. */ 132 /* For compression, they must be supplied by parameter setup; */ 133 /* for decompression, they are read from the SOS marker. */ 134 /* The decompressor output side may not use these variables. */ 135 int dc_tbl_no; /* DC entropy table selector (0..3) */ 136 int ac_tbl_no; /* AC entropy table selector (0..3) */ 137 138 /* Remaining fields should be treated as private by applications. */ 139 140 /* These values are computed during compression or decompression startup: */ 141 /* Component's size in DCT blocks. 142 * Any dummy blocks added to complete an MCU are not counted; therefore 143 * these values do not depend on whether a scan is interleaved or not. 144 */ 145 JDIMENSION width_in_blocks; 146 JDIMENSION height_in_blocks; 147 /* Size of a DCT block in samples. Always DCTSIZE for compression. 148 * For decompression this is the size of the output from one DCT block, 149 * reflecting any scaling we choose to apply during the IDCT step. 150 * Values from 1 to 16 are supported. 151 * Note that different components may receive different IDCT scalings. 152 */ 153 #if JPEG_LIB_VERSION >= 70 154 int DCT_h_scaled_size; 155 int DCT_v_scaled_size; 156 #else 157 int DCT_scaled_size; 158 #endif 159 /* The downsampled dimensions are the component's actual, unpadded number 160 * of samples at the main buffer (preprocessing/compression interface), thus 161 * downsampled_width = ceil(image_width * Hi/Hmax) 162 * and similarly for height. For decompression, IDCT scaling is included, so 163 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]scaled_size/DCTSIZE) 164 */ 165 JDIMENSION downsampled_width; /* actual width in samples */ 166 JDIMENSION downsampled_height; /* actual height in samples */ 167 /* This flag is used only for decompression. In cases where some of the 168 * components will be ignored (eg grayscale output from YCbCr image), 169 * we can skip most computations for the unused components. 170 */ 171 boolean component_needed; /* do we need the value of this component? */ 172 173 /* These values are computed before starting a scan of the component. */ 174 /* The decompressor output side may not use these variables. */ 175 int MCU_width; /* number of blocks per MCU, horizontally */ 176 int MCU_height; /* number of blocks per MCU, vertically */ 177 int MCU_blocks; /* MCU_width * MCU_height */ 178 int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_[h_]scaled_size */ 179 int last_col_width; /* # of non-dummy blocks across in last MCU */ 180 int last_row_height; /* # of non-dummy blocks down in last MCU */ 181 182 /* Saved quantization table for component; NULL if none yet saved. 183 * See jdinput.c comments about the need for this information. 184 * This field is currently used only for decompression. 185 */ 186 JQUANT_TBL *quant_table; 187 188 /* Private per-component storage for DCT or IDCT subsystem. */ 189 void *dct_table; 190 } jpeg_component_info; 191 192 193 /* The script for encoding a multiple-scan file is an array of these: */ 194 195 typedef struct { 196 int comps_in_scan; /* number of components encoded in this scan */ 197 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */ 198 int Ss, Se; /* progressive JPEG spectral selection parms */ 199 int Ah, Al; /* progressive JPEG successive approx. parms */ 200 } jpeg_scan_info; 201 202 /* The decompressor can save APPn and COM markers in a list of these: */ 203 204 typedef struct jpeg_marker_struct *jpeg_saved_marker_ptr; 205 206 struct jpeg_marker_struct { 207 jpeg_saved_marker_ptr next; /* next in list, or NULL */ 208 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */ 209 unsigned int original_length; /* # bytes of data in the file */ 210 unsigned int data_length; /* # bytes of data saved at data[] */ 211 JOCTET *data; /* the data contained in the marker */ 212 /* the marker length word is not counted in data_length or original_length */ 213 }; 214 215 /* Known color spaces. */ 216 217 #define JCS_EXTENSIONS 1 218 #define JCS_ALPHA_EXTENSIONS 1 219 220 typedef enum { 221 JCS_UNKNOWN, /* error/unspecified */ 222 JCS_GRAYSCALE, /* monochrome */ 223 JCS_RGB, /* red/green/blue as specified by the RGB_RED, 224 RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros */ 225 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */ 226 JCS_CMYK, /* C/M/Y/K */ 227 JCS_YCCK, /* Y/Cb/Cr/K */ 228 JCS_EXT_RGB, /* red/green/blue */ 229 JCS_EXT_RGBX, /* red/green/blue/x */ 230 JCS_EXT_BGR, /* blue/green/red */ 231 JCS_EXT_BGRX, /* blue/green/red/x */ 232 JCS_EXT_XBGR, /* x/blue/green/red */ 233 JCS_EXT_XRGB, /* x/red/green/blue */ 234 /* When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX, JCS_EXT_XBGR, 235 or JCS_EXT_XRGB during decompression, the X byte is undefined, and in 236 order to ensure the best performance, libjpeg-turbo can set that byte to 237 whatever value it wishes. Use the following colorspace constants to 238 ensure that the X byte is set to 0xFF, so that it can be interpreted as an 239 opaque alpha channel. */ 240 JCS_EXT_RGBA, /* red/green/blue/alpha */ 241 JCS_EXT_BGRA, /* blue/green/red/alpha */ 242 JCS_EXT_ABGR, /* alpha/blue/green/red */ 243 JCS_EXT_ARGB, /* alpha/red/green/blue */ 244 JCS_RGB565 /* 5-bit red/6-bit green/5-bit blue */ 245 } J_COLOR_SPACE; 246 247 /* DCT/IDCT algorithm options. */ 248 249 typedef enum { 250 JDCT_ISLOW, /* slow but accurate integer algorithm */ 251 JDCT_IFAST, /* faster, less accurate integer method */ 252 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */ 253 } J_DCT_METHOD; 254 255 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */ 256 #define JDCT_DEFAULT JDCT_ISLOW 257 #endif 258 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */ 259 #define JDCT_FASTEST JDCT_IFAST 260 #endif 261 262 /* Dithering options for decompression. */ 263 264 typedef enum { 265 JDITHER_NONE, /* no dithering */ 266 JDITHER_ORDERED, /* simple ordered dither */ 267 JDITHER_FS /* Floyd-Steinberg error diffusion dither */ 268 } J_DITHER_MODE; 269 270 271 /* Common fields between JPEG compression and decompression master structs. */ 272 273 #define jpeg_common_fields \ 274 struct jpeg_error_mgr *err; /* Error handler module */\ 275 struct jpeg_memory_mgr *mem; /* Memory manager module */\ 276 struct jpeg_progress_mgr *progress; /* Progress monitor, or NULL if none */\ 277 void *client_data; /* Available for use by application */\ 278 boolean is_decompressor; /* So common code can tell which is which */\ 279 int global_state /* For checking call sequence validity */ 280 281 /* Routines that are to be used by both halves of the library are declared 282 * to receive a pointer to this structure. There are no actual instances of 283 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct. 284 */ 285 struct jpeg_common_struct { 286 jpeg_common_fields; /* Fields common to both master struct types */ 287 /* Additional fields follow in an actual jpeg_compress_struct or 288 * jpeg_decompress_struct. All three structs must agree on these 289 * initial fields! (This would be a lot cleaner in C++.) 290 */ 291 }; 292 293 typedef struct jpeg_common_struct *j_common_ptr; 294 typedef struct jpeg_compress_struct *j_compress_ptr; 295 typedef struct jpeg_decompress_struct *j_decompress_ptr; 296 297 298 /* Master record for a compression instance */ 299 300 struct jpeg_compress_struct { 301 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */ 302 303 /* Destination for compressed data */ 304 struct jpeg_destination_mgr *dest; 305 306 /* Description of source image --- these fields must be filled in by 307 * outer application before starting compression. in_color_space must 308 * be correct before you can even call jpeg_set_defaults(). 309 */ 310 311 JDIMENSION image_width; /* input image width */ 312 JDIMENSION image_height; /* input image height */ 313 int input_components; /* # of color components in input image */ 314 J_COLOR_SPACE in_color_space; /* colorspace of input image */ 315 316 double input_gamma; /* image gamma of input image */ 317 318 /* Compression parameters --- these fields must be set before calling 319 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to 320 * initialize everything to reasonable defaults, then changing anything 321 * the application specifically wants to change. That way you won't get 322 * burnt when new parameters are added. Also note that there are several 323 * helper routines to simplify changing parameters. 324 */ 325 326 #if JPEG_LIB_VERSION >= 70 327 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 328 329 JDIMENSION jpeg_width; /* scaled JPEG image width */ 330 JDIMENSION jpeg_height; /* scaled JPEG image height */ 331 /* Dimensions of actual JPEG image that will be written to file, 332 * derived from input dimensions by scaling factors above. 333 * These fields are computed by jpeg_start_compress(). 334 * You can also use jpeg_calc_jpeg_dimensions() to determine these values 335 * in advance of calling jpeg_start_compress(). 336 */ 337 #endif 338 339 int data_precision; /* bits of precision in image data */ 340 341 int num_components; /* # of color components in JPEG image */ 342 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 343 344 jpeg_component_info *comp_info; 345 /* comp_info[i] describes component that appears i'th in SOF */ 346 347 JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS]; 348 #if JPEG_LIB_VERSION >= 70 349 int q_scale_factor[NUM_QUANT_TBLS]; 350 #endif 351 /* ptrs to coefficient quantization tables, or NULL if not defined, 352 * and corresponding scale factors (percentage, initialized 100). 353 */ 354 355 JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 356 JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 357 /* ptrs to Huffman coding tables, or NULL if not defined */ 358 359 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 360 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 361 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 362 363 int num_scans; /* # of entries in scan_info array */ 364 const jpeg_scan_info *scan_info; /* script for multi-scan file, or NULL */ 365 /* The default value of scan_info is NULL, which causes a single-scan 366 * sequential JPEG file to be emitted. To create a multi-scan file, 367 * set num_scans and scan_info to point to an array of scan definitions. 368 */ 369 370 boolean raw_data_in; /* TRUE=caller supplies downsampled data */ 371 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 372 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */ 373 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 374 #if JPEG_LIB_VERSION >= 70 375 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */ 376 #endif 377 int smoothing_factor; /* 1..100, or 0 for no input smoothing */ 378 J_DCT_METHOD dct_method; /* DCT algorithm selector */ 379 380 /* The restart interval can be specified in absolute MCUs by setting 381 * restart_interval, or in MCU rows by setting restart_in_rows 382 * (in which case the correct restart_interval will be figured 383 * for each scan). 384 */ 385 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */ 386 int restart_in_rows; /* if > 0, MCU rows per restart interval */ 387 388 /* Parameters controlling emission of special markers. */ 389 390 boolean write_JFIF_header; /* should a JFIF marker be written? */ 391 UINT8 JFIF_major_version; /* What to write for the JFIF version number */ 392 UINT8 JFIF_minor_version; 393 /* These three values are not used by the JPEG code, merely copied */ 394 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */ 395 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */ 396 /* ratio is defined by X_density/Y_density even when density_unit=0. */ 397 UINT8 density_unit; /* JFIF code for pixel size units */ 398 UINT16 X_density; /* Horizontal pixel density */ 399 UINT16 Y_density; /* Vertical pixel density */ 400 boolean write_Adobe_marker; /* should an Adobe marker be written? */ 401 402 /* State variable: index of next scanline to be written to 403 * jpeg_write_scanlines(). Application may use this to control its 404 * processing loop, e.g., "while (next_scanline < image_height)". 405 */ 406 407 JDIMENSION next_scanline; /* 0 .. image_height-1 */ 408 409 /* Remaining fields are known throughout compressor, but generally 410 * should not be touched by a surrounding application. 411 */ 412 413 /* 414 * These fields are computed during compression startup 415 */ 416 boolean progressive_mode; /* TRUE if scan script uses progressive mode */ 417 int max_h_samp_factor; /* largest h_samp_factor */ 418 int max_v_samp_factor; /* largest v_samp_factor */ 419 420 #if JPEG_LIB_VERSION >= 70 421 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 422 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 423 #endif 424 425 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */ 426 /* The coefficient controller receives data in units of MCU rows as defined 427 * for fully interleaved scans (whether the JPEG file is interleaved or not). 428 * There are v_samp_factor * DCTSIZE sample rows of each component in an 429 * "iMCU" (interleaved MCU) row. 430 */ 431 432 /* 433 * These fields are valid during any one scan. 434 * They describe the components and MCUs actually appearing in the scan. 435 */ 436 int comps_in_scan; /* # of JPEG components in this scan */ 437 jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN]; 438 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 439 440 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 441 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 442 443 int blocks_in_MCU; /* # of DCT blocks per MCU */ 444 int MCU_membership[C_MAX_BLOCKS_IN_MCU]; 445 /* MCU_membership[i] is index in cur_comp_info of component owning */ 446 /* i'th block in an MCU */ 447 448 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 449 450 #if JPEG_LIB_VERSION >= 80 451 int block_size; /* the basic DCT block size: 1..16 */ 452 const int *natural_order; /* natural-order position array */ 453 int lim_Se; /* min( Se, DCTSIZE2-1 ) */ 454 #endif 455 456 /* 457 * Links to compression subobjects (methods and private variables of modules) 458 */ 459 struct jpeg_comp_master *master; 460 struct jpeg_c_main_controller *main; 461 struct jpeg_c_prep_controller *prep; 462 struct jpeg_c_coef_controller *coef; 463 struct jpeg_marker_writer *marker; 464 struct jpeg_color_converter *cconvert; 465 struct jpeg_downsampler *downsample; 466 struct jpeg_forward_dct *fdct; 467 struct jpeg_entropy_encoder *entropy; 468 jpeg_scan_info *script_space; /* workspace for jpeg_simple_progression */ 469 int script_space_size; 470 }; 471 472 473 /* Master record for a decompression instance */ 474 475 struct jpeg_decompress_struct { 476 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */ 477 478 /* Source of compressed data */ 479 struct jpeg_source_mgr *src; 480 481 /* Basic description of image --- filled in by jpeg_read_header(). */ 482 /* Application may inspect these values to decide how to process image. */ 483 484 JDIMENSION image_width; /* nominal image width (from SOF marker) */ 485 JDIMENSION image_height; /* nominal image height */ 486 int num_components; /* # of color components in JPEG image */ 487 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 488 489 /* Decompression processing parameters --- these fields must be set before 490 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes 491 * them to default values. 492 */ 493 494 J_COLOR_SPACE out_color_space; /* colorspace for output */ 495 496 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 497 498 double output_gamma; /* image gamma wanted in output */ 499 500 boolean buffered_image; /* TRUE=multiple output passes */ 501 boolean raw_data_out; /* TRUE=downsampled data wanted */ 502 503 J_DCT_METHOD dct_method; /* IDCT algorithm selector */ 504 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */ 505 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */ 506 507 boolean quantize_colors; /* TRUE=colormapped output wanted */ 508 /* the following are ignored if not quantize_colors: */ 509 J_DITHER_MODE dither_mode; /* type of color dithering to use */ 510 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */ 511 int desired_number_of_colors; /* max # colors to use in created colormap */ 512 /* these are significant only in buffered-image mode: */ 513 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */ 514 boolean enable_external_quant;/* enable future use of external colormap */ 515 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */ 516 517 /* Description of actual output image that will be returned to application. 518 * These fields are computed by jpeg_start_decompress(). 519 * You can also use jpeg_calc_output_dimensions() to determine these values 520 * in advance of calling jpeg_start_decompress(). 521 */ 522 523 JDIMENSION output_width; /* scaled image width */ 524 JDIMENSION output_height; /* scaled image height */ 525 int out_color_components; /* # of color components in out_color_space */ 526 int output_components; /* # of color components returned */ 527 /* output_components is 1 (a colormap index) when quantizing colors; 528 * otherwise it equals out_color_components. 529 */ 530 int rec_outbuf_height; /* min recommended height of scanline buffer */ 531 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows 532 * high, space and time will be wasted due to unnecessary data copying. 533 * Usually rec_outbuf_height will be 1 or 2, at most 4. 534 */ 535 536 /* When quantizing colors, the output colormap is described by these fields. 537 * The application can supply a colormap by setting colormap non-NULL before 538 * calling jpeg_start_decompress; otherwise a colormap is created during 539 * jpeg_start_decompress or jpeg_start_output. 540 * The map has out_color_components rows and actual_number_of_colors columns. 541 */ 542 int actual_number_of_colors; /* number of entries in use */ 543 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */ 544 545 /* State variables: these variables indicate the progress of decompression. 546 * The application may examine these but must not modify them. 547 */ 548 549 /* Row index of next scanline to be read from jpeg_read_scanlines(). 550 * Application may use this to control its processing loop, e.g., 551 * "while (output_scanline < output_height)". 552 */ 553 JDIMENSION output_scanline; /* 0 .. output_height-1 */ 554 555 /* Current input scan number and number of iMCU rows completed in scan. 556 * These indicate the progress of the decompressor input side. 557 */ 558 int input_scan_number; /* Number of SOS markers seen so far */ 559 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */ 560 561 /* The "output scan number" is the notional scan being displayed by the 562 * output side. The decompressor will not allow output scan/row number 563 * to get ahead of input scan/row, but it can fall arbitrarily far behind. 564 */ 565 int output_scan_number; /* Nominal scan number being displayed */ 566 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */ 567 568 /* Current progression status. coef_bits[c][i] indicates the precision 569 * with which component c's DCT coefficient i (in zigzag order) is known. 570 * It is -1 when no data has yet been received, otherwise it is the point 571 * transform (shift) value for the most recent scan of the coefficient 572 * (thus, 0 at completion of the progression). 573 * This pointer is NULL when reading a non-progressive file. 574 */ 575 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */ 576 577 /* Internal JPEG parameters --- the application usually need not look at 578 * these fields. Note that the decompressor output side may not use 579 * any parameters that can change between scans. 580 */ 581 582 /* Quantization and Huffman tables are carried forward across input 583 * datastreams when processing abbreviated JPEG datastreams. 584 */ 585 586 JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS]; 587 /* ptrs to coefficient quantization tables, or NULL if not defined */ 588 589 JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 590 JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 591 /* ptrs to Huffman coding tables, or NULL if not defined */ 592 593 /* These parameters are never carried across datastreams, since they 594 * are given in SOF/SOS markers or defined to be reset by SOI. 595 */ 596 597 int data_precision; /* bits of precision in image data */ 598 599 jpeg_component_info *comp_info; 600 /* comp_info[i] describes component that appears i'th in SOF */ 601 602 #if JPEG_LIB_VERSION >= 80 603 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */ 604 #endif 605 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */ 606 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 607 608 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 609 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 610 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 611 612 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */ 613 614 /* These fields record data obtained from optional markers recognized by 615 * the JPEG library. 616 */ 617 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */ 618 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */ 619 UINT8 JFIF_major_version; /* JFIF version number */ 620 UINT8 JFIF_minor_version; 621 UINT8 density_unit; /* JFIF code for pixel size units */ 622 UINT16 X_density; /* Horizontal pixel density */ 623 UINT16 Y_density; /* Vertical pixel density */ 624 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */ 625 UINT8 Adobe_transform; /* Color transform code from Adobe marker */ 626 627 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 628 629 /* Aside from the specific data retained from APPn markers known to the 630 * library, the uninterpreted contents of any or all APPn and COM markers 631 * can be saved in a list for examination by the application. 632 */ 633 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */ 634 635 /* Remaining fields are known throughout decompressor, but generally 636 * should not be touched by a surrounding application. 637 */ 638 639 /* 640 * These fields are computed during decompression startup 641 */ 642 int max_h_samp_factor; /* largest h_samp_factor */ 643 int max_v_samp_factor; /* largest v_samp_factor */ 644 645 #if JPEG_LIB_VERSION >= 70 646 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 647 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 648 #else 649 int min_DCT_scaled_size; /* smallest DCT_scaled_size of any component */ 650 #endif 651 652 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */ 653 /* The coefficient controller's input and output progress is measured in 654 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows 655 * in fully interleaved JPEG scans, but are used whether the scan is 656 * interleaved or not. We define an iMCU row as v_samp_factor DCT block 657 * rows of each component. Therefore, the IDCT output contains 658 * v_samp_factor*DCT_[v_]scaled_size sample rows of a component per iMCU row. 659 */ 660 661 JSAMPLE *sample_range_limit; /* table for fast range-limiting */ 662 663 /* 664 * These fields are valid during any one scan. 665 * They describe the components and MCUs actually appearing in the scan. 666 * Note that the decompressor output side must not use these fields. 667 */ 668 int comps_in_scan; /* # of JPEG components in this scan */ 669 jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN]; 670 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 671 672 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 673 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 674 675 int blocks_in_MCU; /* # of DCT blocks per MCU */ 676 int MCU_membership[D_MAX_BLOCKS_IN_MCU]; 677 /* MCU_membership[i] is index in cur_comp_info of component owning */ 678 /* i'th block in an MCU */ 679 680 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 681 682 #if JPEG_LIB_VERSION >= 80 683 /* These fields are derived from Se of first SOS marker. 684 */ 685 int block_size; /* the basic DCT block size: 1..16 */ 686 const int *natural_order; /* natural-order position array for entropy decode */ 687 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */ 688 #endif 689 690 /* This field is shared between entropy decoder and marker parser. 691 * It is either zero or the code of a JPEG marker that has been 692 * read from the data source, but has not yet been processed. 693 */ 694 int unread_marker; 695 696 /* 697 * Links to decompression subobjects (methods, private variables of modules) 698 */ 699 struct jpeg_decomp_master *master; 700 struct jpeg_d_main_controller *main; 701 struct jpeg_d_coef_controller *coef; 702 struct jpeg_d_post_controller *post; 703 struct jpeg_input_controller *inputctl; 704 struct jpeg_marker_reader *marker; 705 struct jpeg_entropy_decoder *entropy; 706 struct jpeg_inverse_dct *idct; 707 struct jpeg_upsampler *upsample; 708 struct jpeg_color_deconverter *cconvert; 709 struct jpeg_color_quantizer *cquantize; 710 }; 711 712 713 /* "Object" declarations for JPEG modules that may be supplied or called 714 * directly by the surrounding application. 715 * As with all objects in the JPEG library, these structs only define the 716 * publicly visible methods and state variables of a module. Additional 717 * private fields may exist after the public ones. 718 */ 719 720 721 /* Error handler object */ 722 723 struct jpeg_error_mgr { 724 /* Error exit handler: does not return to caller */ 725 void (*error_exit) (j_common_ptr cinfo); 726 /* Conditionally emit a trace or warning message */ 727 void (*emit_message) (j_common_ptr cinfo, int msg_level); 728 /* Routine that actually outputs a trace or error message */ 729 void (*output_message) (j_common_ptr cinfo); 730 /* Format a message string for the most recent JPEG error or message */ 731 void (*format_message) (j_common_ptr cinfo, char *buffer); 732 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */ 733 /* Reset error state variables at start of a new image */ 734 void (*reset_error_mgr) (j_common_ptr cinfo); 735 736 /* The message ID code and any parameters are saved here. 737 * A message can have one string parameter or up to 8 int parameters. 738 */ 739 int msg_code; 740 #define JMSG_STR_PARM_MAX 80 741 union { 742 int i[8]; 743 char s[JMSG_STR_PARM_MAX]; 744 } msg_parm; 745 746 /* Standard state variables for error facility */ 747 748 int trace_level; /* max msg_level that will be displayed */ 749 750 /* For recoverable corrupt-data errors, we emit a warning message, 751 * but keep going unless emit_message chooses to abort. emit_message 752 * should count warnings in num_warnings. The surrounding application 753 * can check for bad data by seeing if num_warnings is nonzero at the 754 * end of processing. 755 */ 756 long num_warnings; /* number of corrupt-data warnings */ 757 758 /* These fields point to the table(s) of error message strings. 759 * An application can change the table pointer to switch to a different 760 * message list (typically, to change the language in which errors are 761 * reported). Some applications may wish to add additional error codes 762 * that will be handled by the JPEG library error mechanism; the second 763 * table pointer is used for this purpose. 764 * 765 * First table includes all errors generated by JPEG library itself. 766 * Error code 0 is reserved for a "no such error string" message. 767 */ 768 const char * const *jpeg_message_table; /* Library errors */ 769 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */ 770 /* Second table can be added by application (see cjpeg/djpeg for example). 771 * It contains strings numbered first_addon_message..last_addon_message. 772 */ 773 const char * const *addon_message_table; /* Non-library errors */ 774 int first_addon_message; /* code for first string in addon table */ 775 int last_addon_message; /* code for last string in addon table */ 776 }; 777 778 779 /* Progress monitor object */ 780 781 struct jpeg_progress_mgr { 782 void (*progress_monitor) (j_common_ptr cinfo); 783 784 long pass_counter; /* work units completed in this pass */ 785 long pass_limit; /* total number of work units in this pass */ 786 int completed_passes; /* passes completed so far */ 787 int total_passes; /* total number of passes expected */ 788 }; 789 790 791 /* Data destination object for compression */ 792 793 struct jpeg_destination_mgr { 794 JOCTET *next_output_byte; /* => next byte to write in buffer */ 795 size_t free_in_buffer; /* # of byte spaces remaining in buffer */ 796 797 void (*init_destination) (j_compress_ptr cinfo); 798 boolean (*empty_output_buffer) (j_compress_ptr cinfo); 799 void (*term_destination) (j_compress_ptr cinfo); 800 }; 801 802 803 /* Data source object for decompression */ 804 805 struct jpeg_source_mgr { 806 const JOCTET *next_input_byte; /* => next byte to read from buffer */ 807 size_t bytes_in_buffer; /* # of bytes remaining in buffer */ 808 809 void (*init_source) (j_decompress_ptr cinfo); 810 boolean (*fill_input_buffer) (j_decompress_ptr cinfo); 811 void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes); 812 boolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired); 813 void (*term_source) (j_decompress_ptr cinfo); 814 }; 815 816 817 /* Memory manager object. 818 * Allocates "small" objects (a few K total), "large" objects (tens of K), 819 * and "really big" objects (virtual arrays with backing store if needed). 820 * The memory manager does not allow individual objects to be freed; rather, 821 * each created object is assigned to a pool, and whole pools can be freed 822 * at once. This is faster and more convenient than remembering exactly what 823 * to free, especially where malloc()/free() are not too speedy. 824 * NB: alloc routines never return NULL. They exit to error_exit if not 825 * successful. 826 */ 827 828 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */ 829 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */ 830 #define JPOOL_NUMPOOLS 2 831 832 typedef struct jvirt_sarray_control *jvirt_sarray_ptr; 833 typedef struct jvirt_barray_control *jvirt_barray_ptr; 834 835 836 struct jpeg_memory_mgr { 837 /* Method pointers */ 838 void *(*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject); 839 void *(*alloc_large) (j_common_ptr cinfo, int pool_id, 840 size_t sizeofobject); 841 JSAMPARRAY (*alloc_sarray) (j_common_ptr cinfo, int pool_id, 842 JDIMENSION samplesperrow, JDIMENSION numrows); 843 JBLOCKARRAY (*alloc_barray) (j_common_ptr cinfo, int pool_id, 844 JDIMENSION blocksperrow, JDIMENSION numrows); 845 jvirt_sarray_ptr (*request_virt_sarray) (j_common_ptr cinfo, int pool_id, 846 boolean pre_zero, 847 JDIMENSION samplesperrow, 848 JDIMENSION numrows, 849 JDIMENSION maxaccess); 850 jvirt_barray_ptr (*request_virt_barray) (j_common_ptr cinfo, int pool_id, 851 boolean pre_zero, 852 JDIMENSION blocksperrow, 853 JDIMENSION numrows, 854 JDIMENSION maxaccess); 855 void (*realize_virt_arrays) (j_common_ptr cinfo); 856 JSAMPARRAY (*access_virt_sarray) (j_common_ptr cinfo, jvirt_sarray_ptr ptr, 857 JDIMENSION start_row, JDIMENSION num_rows, 858 boolean writable); 859 JBLOCKARRAY (*access_virt_barray) (j_common_ptr cinfo, jvirt_barray_ptr ptr, 860 JDIMENSION start_row, JDIMENSION num_rows, 861 boolean writable); 862 void (*free_pool) (j_common_ptr cinfo, int pool_id); 863 void (*self_destruct) (j_common_ptr cinfo); 864 865 /* Limit on memory allocation for this JPEG object. (Note that this is 866 * merely advisory, not a guaranteed maximum; it only affects the space 867 * used for virtual-array buffers.) May be changed by outer application 868 * after creating the JPEG object. 869 */ 870 long max_memory_to_use; 871 872 /* Maximum allocation request accepted by alloc_large. */ 873 long max_alloc_chunk; 874 }; 875 876 877 /* Routine signature for application-supplied marker processing methods. 878 * Need not pass marker code since it is stored in cinfo->unread_marker. 879 */ 880 typedef boolean (*jpeg_marker_parser_method) (j_decompress_ptr cinfo); 881 882 883 /* Originally, this macro was used as a way of defining function prototypes 884 * for both modern compilers as well as older compilers that did not support 885 * prototype parameters. libjpeg-turbo has never supported these older, 886 * non-ANSI compilers, but the macro is still included because there is some 887 * software out there that uses it. 888 */ 889 890 #define JPP(arglist) arglist 891 892 893 /* Default error-management setup */ 894 EXTERN(struct jpeg_error_mgr *) jpeg_std_error (struct jpeg_error_mgr *err); 895 896 /* Initialization of JPEG compression objects. 897 * jpeg_create_compress() and jpeg_create_decompress() are the exported 898 * names that applications should call. These expand to calls on 899 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information 900 * passed for version mismatch checking. 901 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx. 902 */ 903 #define jpeg_create_compress(cinfo) \ 904 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \ 905 (size_t) sizeof(struct jpeg_compress_struct)) 906 #define jpeg_create_decompress(cinfo) \ 907 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \ 908 (size_t) sizeof(struct jpeg_decompress_struct)) 909 EXTERN(void) jpeg_CreateCompress (j_compress_ptr cinfo, int version, 910 size_t structsize); 911 EXTERN(void) jpeg_CreateDecompress (j_decompress_ptr cinfo, int version, 912 size_t structsize); 913 /* Destruction of JPEG compression objects */ 914 EXTERN(void) jpeg_destroy_compress (j_compress_ptr cinfo); 915 EXTERN(void) jpeg_destroy_decompress (j_decompress_ptr cinfo); 916 917 /* Standard data source and destination managers: stdio streams. */ 918 /* Caller is responsible for opening the file before and closing after. */ 919 EXTERN(void) jpeg_stdio_dest (j_compress_ptr cinfo, FILE *outfile); 920 EXTERN(void) jpeg_stdio_src (j_decompress_ptr cinfo, FILE *infile); 921 922 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED) 923 /* Data source and destination managers: memory buffers. */ 924 EXTERN(void) jpeg_mem_dest (j_compress_ptr cinfo, unsigned char **outbuffer, 925 unsigned long *outsize); 926 EXTERN(void) jpeg_mem_src (j_decompress_ptr cinfo, 927 const unsigned char *inbuffer, 928 unsigned long insize); 929 #endif 930 931 /* Default parameter setup for compression */ 932 EXTERN(void) jpeg_set_defaults (j_compress_ptr cinfo); 933 /* Compression parameter setup aids */ 934 EXTERN(void) jpeg_set_colorspace (j_compress_ptr cinfo, 935 J_COLOR_SPACE colorspace); 936 EXTERN(void) jpeg_default_colorspace (j_compress_ptr cinfo); 937 EXTERN(void) jpeg_set_quality (j_compress_ptr cinfo, int quality, 938 boolean force_baseline); 939 EXTERN(void) jpeg_set_linear_quality (j_compress_ptr cinfo, int scale_factor, 940 boolean force_baseline); 941 #if JPEG_LIB_VERSION >= 70 942 EXTERN(void) jpeg_default_qtables (j_compress_ptr cinfo, 943 boolean force_baseline); 944 #endif 945 EXTERN(void) jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl, 946 const unsigned int *basic_table, 947 int scale_factor, boolean force_baseline); 948 EXTERN(int) jpeg_quality_scaling (int quality); 949 EXTERN(void) jpeg_simple_progression (j_compress_ptr cinfo); 950 EXTERN(void) jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress); 951 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table (j_common_ptr cinfo); 952 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table (j_common_ptr cinfo); 953 954 /* Main entry points for compression */ 955 EXTERN(void) jpeg_start_compress (j_compress_ptr cinfo, 956 boolean write_all_tables); 957 EXTERN(JDIMENSION) jpeg_write_scanlines (j_compress_ptr cinfo, 958 JSAMPARRAY scanlines, 959 JDIMENSION num_lines); 960 EXTERN(void) jpeg_finish_compress (j_compress_ptr cinfo); 961 962 #if JPEG_LIB_VERSION >= 70 963 /* Precalculate JPEG dimensions for current compression parameters. */ 964 EXTERN(void) jpeg_calc_jpeg_dimensions (j_compress_ptr cinfo); 965 #endif 966 967 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */ 968 EXTERN(JDIMENSION) jpeg_write_raw_data (j_compress_ptr cinfo, JSAMPIMAGE data, 969 JDIMENSION num_lines); 970 971 /* Write a special marker. See libjpeg.txt concerning safe usage. */ 972 EXTERN(void) jpeg_write_marker (j_compress_ptr cinfo, int marker, 973 const JOCTET *dataptr, unsigned int datalen); 974 /* Same, but piecemeal. */ 975 EXTERN(void) jpeg_write_m_header (j_compress_ptr cinfo, int marker, 976 unsigned int datalen); 977 EXTERN(void) jpeg_write_m_byte (j_compress_ptr cinfo, int val); 978 979 /* Alternate compression function: just write an abbreviated table file */ 980 EXTERN(void) jpeg_write_tables (j_compress_ptr cinfo); 981 982 /* Decompression startup: read start of JPEG datastream to see what's there */ 983 EXTERN(int) jpeg_read_header (j_decompress_ptr cinfo, boolean require_image); 984 /* Return value is one of: */ 985 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */ 986 #define JPEG_HEADER_OK 1 /* Found valid image datastream */ 987 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */ 988 /* If you pass require_image = TRUE (normal case), you need not check for 989 * a TABLES_ONLY return code; an abbreviated file will cause an error exit. 990 * JPEG_SUSPENDED is only possible if you use a data source module that can 991 * give a suspension return (the stdio source module doesn't). 992 */ 993 994 /* Main entry points for decompression */ 995 EXTERN(boolean) jpeg_start_decompress (j_decompress_ptr cinfo); 996 EXTERN(JDIMENSION) jpeg_read_scanlines (j_decompress_ptr cinfo, 997 JSAMPARRAY scanlines, 998 JDIMENSION max_lines); 999 EXTERN(JDIMENSION) jpeg_skip_scanlines (j_decompress_ptr cinfo, 1000 JDIMENSION num_lines); 1001 EXTERN(void) jpeg_crop_scanline (j_decompress_ptr cinfo, JDIMENSION *xoffset, 1002 JDIMENSION *width); 1003 EXTERN(boolean) jpeg_finish_decompress (j_decompress_ptr cinfo); 1004 1005 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */ 1006 EXTERN(JDIMENSION) jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data, 1007 JDIMENSION max_lines); 1008 1009 /* Additional entry points for buffered-image mode. */ 1010 EXTERN(boolean) jpeg_has_multiple_scans (j_decompress_ptr cinfo); 1011 EXTERN(boolean) jpeg_start_output (j_decompress_ptr cinfo, int scan_number); 1012 EXTERN(boolean) jpeg_finish_output (j_decompress_ptr cinfo); 1013 EXTERN(boolean) jpeg_input_complete (j_decompress_ptr cinfo); 1014 EXTERN(void) jpeg_new_colormap (j_decompress_ptr cinfo); 1015 EXTERN(int) jpeg_consume_input (j_decompress_ptr cinfo); 1016 /* Return value is one of: */ 1017 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */ 1018 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */ 1019 #define JPEG_REACHED_EOI 2 /* Reached end of image */ 1020 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */ 1021 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */ 1022 1023 /* Precalculate output dimensions for current decompression parameters. */ 1024 #if JPEG_LIB_VERSION >= 80 1025 EXTERN(void) jpeg_core_output_dimensions (j_decompress_ptr cinfo); 1026 #endif 1027 EXTERN(void) jpeg_calc_output_dimensions (j_decompress_ptr cinfo); 1028 1029 /* Control saving of COM and APPn markers into marker_list. */ 1030 EXTERN(void) jpeg_save_markers (j_decompress_ptr cinfo, int marker_code, 1031 unsigned int length_limit); 1032 1033 /* Install a special processing method for COM or APPn markers. */ 1034 EXTERN(void) jpeg_set_marker_processor (j_decompress_ptr cinfo, 1035 int marker_code, 1036 jpeg_marker_parser_method routine); 1037 1038 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */ 1039 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients (j_decompress_ptr cinfo); 1040 EXTERN(void) jpeg_write_coefficients (j_compress_ptr cinfo, 1041 jvirt_barray_ptr *coef_arrays); 1042 EXTERN(void) jpeg_copy_critical_parameters (j_decompress_ptr srcinfo, 1043 j_compress_ptr dstinfo); 1044 1045 /* If you choose to abort compression or decompression before completing 1046 * jpeg_finish_(de)compress, then you need to clean up to release memory, 1047 * temporary files, etc. You can just call jpeg_destroy_(de)compress 1048 * if you're done with the JPEG object, but if you want to clean it up and 1049 * reuse it, call this: 1050 */ 1051 EXTERN(void) jpeg_abort_compress (j_compress_ptr cinfo); 1052 EXTERN(void) jpeg_abort_decompress (j_decompress_ptr cinfo); 1053 1054 /* Generic versions of jpeg_abort and jpeg_destroy that work on either 1055 * flavor of JPEG object. These may be more convenient in some places. 1056 */ 1057 EXTERN(void) jpeg_abort (j_common_ptr cinfo); 1058 EXTERN(void) jpeg_destroy (j_common_ptr cinfo); 1059 1060 /* Default restart-marker-resync procedure for use by data source modules */ 1061 EXTERN(boolean) jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired); 1062 1063 1064 /* These marker codes are exported since applications and data source modules 1065 * are likely to want to use them. 1066 */ 1067 1068 #define JPEG_RST0 0xD0 /* RST0 marker code */ 1069 #define JPEG_EOI 0xD9 /* EOI marker code */ 1070 #define JPEG_APP0 0xE0 /* APP0 marker code */ 1071 #define JPEG_COM 0xFE /* COM marker code */ 1072 1073 1074 /* If we have a brain-damaged compiler that emits warnings (or worse, errors) 1075 * for structure definitions that are never filled in, keep it quiet by 1076 * supplying dummy definitions for the various substructures. 1077 */ 1078 1079 #ifdef INCOMPLETE_TYPES_BROKEN 1080 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */ 1081 struct jvirt_sarray_control { long dummy; }; 1082 struct jvirt_barray_control { long dummy; }; 1083 struct jpeg_comp_master { long dummy; }; 1084 struct jpeg_c_main_controller { long dummy; }; 1085 struct jpeg_c_prep_controller { long dummy; }; 1086 struct jpeg_c_coef_controller { long dummy; }; 1087 struct jpeg_marker_writer { long dummy; }; 1088 struct jpeg_color_converter { long dummy; }; 1089 struct jpeg_downsampler { long dummy; }; 1090 struct jpeg_forward_dct { long dummy; }; 1091 struct jpeg_entropy_encoder { long dummy; }; 1092 struct jpeg_decomp_master { long dummy; }; 1093 struct jpeg_d_main_controller { long dummy; }; 1094 struct jpeg_d_coef_controller { long dummy; }; 1095 struct jpeg_d_post_controller { long dummy; }; 1096 struct jpeg_input_controller { long dummy; }; 1097 struct jpeg_marker_reader { long dummy; }; 1098 struct jpeg_entropy_decoder { long dummy; }; 1099 struct jpeg_inverse_dct { long dummy; }; 1100 struct jpeg_upsampler { long dummy; }; 1101 struct jpeg_color_deconverter { long dummy; }; 1102 struct jpeg_color_quantizer { long dummy; }; 1103 #endif /* JPEG_INTERNALS */ 1104 #endif /* INCOMPLETE_TYPES_BROKEN */ 1105 1106 1107 /* 1108 * The JPEG library modules define JPEG_INTERNALS before including this file. 1109 * The internal structure declarations are read only when that is true. 1110 * Applications using the library should not include jpegint.h, but may wish 1111 * to include jerror.h. 1112 */ 1113 1114 #ifdef JPEG_INTERNALS 1115 #include "jpegint.h" /* fetch private declarations */ 1116 #include "jerror.h" /* fetch error codes too */ 1117 #endif 1118 1119 #ifdef __cplusplus 1120 #ifndef DONT_USE_EXTERN_C 1121 } 1122 #endif 1123 #endif 1124 1125 #endif /* JPEGLIB_H */ 1126