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0001 /* 0002 * jpeglib.h 0003 * 0004 * This file was part of the Independent JPEG Group's software: 0005 * Copyright (C) 1991-1998, Thomas G. Lane. 0006 * Modified 2002-2009 by Guido Vollbeding. 0007 * Lossless JPEG Modifications: 0008 * Copyright (C) 1999, Ken Murchison. 0009 * libjpeg-turbo Modifications: 0010 * Copyright (C) 2009-2011, 2013-2014, 2016-2017, 2020, 2022-2024, 0011 D. R. Commander. 0012 * Copyright (C) 2015, Google, Inc. 0013 * For conditions of distribution and use, see the accompanying README.ijg 0014 * file. 0015 * 0016 * This file defines the application interface for the JPEG library. 0017 * Most applications using the library need only include this file, 0018 * and perhaps jerror.h if they want to know the exact error codes. 0019 */ 0020 0021 /* NOTE: This header file does not include stdio.h, despite the fact that it 0022 * uses FILE and size_t. That is by design, since the libjpeg API predates the 0023 * widespread adoption of ANSI/ISO C. Referring to libjpeg.txt, it is a 0024 * documented requirement that calling programs "include system headers that 0025 * define at least the typedefs FILE and size_t" before including jpeglib.h. 0026 * Technically speaking, changing that requirement by including stdio.h here 0027 * would break backward API compatibility. Please do not file bug reports, 0028 * feature requests, or pull requests regarding this. 0029 */ 0030 0031 #ifndef JPEGLIB_H 0032 #define JPEGLIB_H 0033 0034 /* 0035 * First we include the configuration files that record how this 0036 * installation of the JPEG library is set up. jconfig.h can be 0037 * generated automatically for many systems. jmorecfg.h contains 0038 * manual configuration options that most people need not worry about. 0039 */ 0040 0041 #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */ 0042 #include "jconfig.h" /* widely used configuration options */ 0043 #endif 0044 #include "jmorecfg.h" /* seldom changed options */ 0045 0046 0047 #ifdef __cplusplus 0048 #ifndef DONT_USE_EXTERN_C 0049 extern "C" { 0050 #endif 0051 #endif 0052 0053 0054 /* Various constants determining the sizes of things. 0055 * All of these are specified by the JPEG standard, so don't change them 0056 * if you want to be compatible. 0057 */ 0058 0059 /* NOTE: In lossless mode, an MCU contains one or more samples rather than one 0060 * or more 8x8 DCT blocks, so the term "data unit" is used to generically 0061 * describe a sample in lossless mode or an 8x8 DCT block in lossy mode. To 0062 * preserve backward API/ABI compatibility, the field and macro names retain 0063 * the "block" terminology. 0064 */ 0065 0066 #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */ 0067 #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */ 0068 #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */ 0069 #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */ 0070 #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */ 0071 #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */ 0072 #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */ 0073 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard; 0074 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU. 0075 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU 0076 * to handle it. We even let you do this from the jconfig.h file. However, 0077 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe 0078 * sometimes emits noncompliant files doesn't mean you should too. 0079 */ 0080 #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on data units/MCU */ 0081 #ifndef D_MAX_BLOCKS_IN_MCU 0082 #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on data units/MCU */ 0083 #endif 0084 0085 0086 /* Data structures for images (arrays of samples and of DCT coefficients). 0087 */ 0088 0089 typedef JSAMPLE *JSAMPROW; /* ptr to one image row of pixel samples with 0090 2-bit through 8-bit data precision. */ 0091 typedef JSAMPROW *JSAMPARRAY; /* ptr to some JSAMPLE rows (a 2-D JSAMPLE 0092 array) */ 0093 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D JSAMPLE array: top index is color */ 0094 0095 typedef J12SAMPLE *J12SAMPROW; /* ptr to one image row of pixel samples 0096 with 9-bit through 12-bit data 0097 precision. */ 0098 typedef J12SAMPROW *J12SAMPARRAY; /* ptr to some J12SAMPLE rows (a 2-D 0099 J12SAMPLE array) */ 0100 typedef J12SAMPARRAY *J12SAMPIMAGE; /* a 3-D J12SAMPLE array: top index is 0101 color */ 0102 0103 typedef J16SAMPLE *J16SAMPROW; /* ptr to one image row of pixel samples 0104 with 13-bit through 16-bit data 0105 precision. */ 0106 typedef J16SAMPROW *J16SAMPARRAY; /* ptr to some J16SAMPLE rows (a 2-D 0107 J16SAMPLE array) */ 0108 typedef J16SAMPARRAY *J16SAMPIMAGE; /* a 3-D J16SAMPLE array: top index is 0109 color */ 0110 0111 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */ 0112 typedef JBLOCK *JBLOCKROW; /* pointer to one row of coefficient blocks */ 0113 typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */ 0114 typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */ 0115 0116 typedef JCOEF *JCOEFPTR; /* useful in a couple of places */ 0117 0118 0119 /* Types for JPEG compression parameters and working tables. */ 0120 0121 0122 /* DCT coefficient quantization tables. */ 0123 0124 typedef struct { 0125 /* This array gives the coefficient quantizers in natural array order 0126 * (not the zigzag order in which they are stored in a JPEG DQT marker). 0127 * CAUTION: IJG versions prior to v6a kept this array in zigzag order. 0128 */ 0129 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */ 0130 /* This field is used only during compression. It's initialized FALSE when 0131 * the table is created, and set TRUE when it's been output to the file. 0132 * You could suppress output of a table by setting this to TRUE. 0133 * (See jpeg_suppress_tables for an example.) 0134 */ 0135 boolean sent_table; /* TRUE when table has been output */ 0136 } JQUANT_TBL; 0137 0138 0139 /* Huffman coding tables. */ 0140 0141 typedef struct { 0142 /* These two fields directly represent the contents of a JPEG DHT marker */ 0143 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */ 0144 /* length k bits; bits[0] is unused */ 0145 UINT8 huffval[256]; /* The symbols, in order of incr code length */ 0146 /* This field is used only during compression. It's initialized FALSE when 0147 * the table is created, and set TRUE when it's been output to the file. 0148 * You could suppress output of a table by setting this to TRUE. 0149 * (See jpeg_suppress_tables for an example.) 0150 */ 0151 boolean sent_table; /* TRUE when table has been output */ 0152 } JHUFF_TBL; 0153 0154 0155 /* Basic info about one component (color channel). */ 0156 0157 typedef struct { 0158 /* These values are fixed over the whole image. */ 0159 /* For compression, they must be supplied by parameter setup; */ 0160 /* for decompression, they are read from the SOF marker. */ 0161 int component_id; /* identifier for this component (0..255) */ 0162 int component_index; /* its index in SOF or cinfo->comp_info[] */ 0163 int h_samp_factor; /* horizontal sampling factor (1..4) */ 0164 int v_samp_factor; /* vertical sampling factor (1..4) */ 0165 int quant_tbl_no; /* quantization table selector (0..3) */ 0166 /* These values may vary between scans. */ 0167 /* For compression, they must be supplied by parameter setup; */ 0168 /* for decompression, they are read from the SOS marker. */ 0169 /* The decompressor output side may not use these variables. */ 0170 int dc_tbl_no; /* DC entropy table selector (0..3) */ 0171 int ac_tbl_no; /* AC entropy table selector (0..3) */ 0172 0173 /* Remaining fields should be treated as private by applications. */ 0174 0175 /* These values are computed during compression or decompression startup: */ 0176 /* Component's size in data units. 0177 * In lossy mode, any dummy blocks added to complete an MCU are not counted; 0178 * therefore these values do not depend on whether a scan is interleaved or 0179 * not. In lossless mode, these are always equal to the image width and 0180 * height. 0181 */ 0182 JDIMENSION width_in_blocks; 0183 JDIMENSION height_in_blocks; 0184 /* Size of a data unit in samples. Always DCTSIZE for lossy compression. 0185 * For lossy decompression this is the size of the output from one DCT block, 0186 * reflecting any scaling we choose to apply during the IDCT step. 0187 * Values from 1 to 16 are supported. Note that different components may 0188 * receive different IDCT scalings. In lossless mode, this is always equal 0189 * to 1. 0190 */ 0191 #if JPEG_LIB_VERSION >= 70 0192 int DCT_h_scaled_size; 0193 int DCT_v_scaled_size; 0194 #else 0195 int DCT_scaled_size; 0196 #endif 0197 /* The downsampled dimensions are the component's actual, unpadded number 0198 * of samples at the main buffer (preprocessing/compression interface), thus 0199 * downsampled_width = ceil(image_width * Hi/Hmax) 0200 * and similarly for height. For lossy decompression, IDCT scaling is 0201 * included, so 0202 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]scaled_size/DCTSIZE) 0203 * In lossless mode, these are always equal to the image width and height. 0204 */ 0205 JDIMENSION downsampled_width; /* actual width in samples */ 0206 JDIMENSION downsampled_height; /* actual height in samples */ 0207 /* This flag is used only for decompression. In cases where some of the 0208 * components will be ignored (eg grayscale output from YCbCr image), 0209 * we can skip most computations for the unused components. 0210 */ 0211 boolean component_needed; /* do we need the value of this component? */ 0212 0213 /* These values are computed before starting a scan of the component. */ 0214 /* The decompressor output side may not use these variables. */ 0215 int MCU_width; /* number of data units per MCU, horizontally */ 0216 int MCU_height; /* number of data units per MCU, vertically */ 0217 int MCU_blocks; /* MCU_width * MCU_height */ 0218 int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_[h_]scaled_size */ 0219 int last_col_width; /* # of non-dummy data units across in last MCU */ 0220 int last_row_height; /* # of non-dummy data units down in last MCU */ 0221 0222 /* Saved quantization table for component; NULL if none yet saved. 0223 * See jdinput.c comments about the need for this information. 0224 * This field is currently used only for decompression. 0225 */ 0226 JQUANT_TBL *quant_table; 0227 0228 /* Private per-component storage for DCT or IDCT subsystem. */ 0229 void *dct_table; 0230 } jpeg_component_info; 0231 0232 0233 /* The script for encoding a multiple-scan file is an array of these: */ 0234 0235 typedef struct { 0236 int comps_in_scan; /* number of components encoded in this scan */ 0237 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */ 0238 int Ss, Se; /* progressive JPEG spectral selection parms 0239 (Ss is the predictor selection value in 0240 lossless mode) */ 0241 int Ah, Al; /* progressive JPEG successive approx. parms 0242 (Al is the point transform value in lossless 0243 mode) */ 0244 } jpeg_scan_info; 0245 0246 /* The decompressor can save APPn and COM markers in a list of these: */ 0247 0248 typedef struct jpeg_marker_struct *jpeg_saved_marker_ptr; 0249 0250 struct jpeg_marker_struct { 0251 jpeg_saved_marker_ptr next; /* next in list, or NULL */ 0252 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */ 0253 unsigned int original_length; /* # bytes of data in the file */ 0254 unsigned int data_length; /* # bytes of data saved at data[] */ 0255 JOCTET *data; /* the data contained in the marker */ 0256 /* the marker length word is not counted in data_length or original_length */ 0257 }; 0258 0259 /* Known color spaces. */ 0260 0261 #define JCS_EXTENSIONS 1 0262 #define JCS_ALPHA_EXTENSIONS 1 0263 0264 typedef enum { 0265 JCS_UNKNOWN, /* error/unspecified */ 0266 JCS_GRAYSCALE, /* monochrome */ 0267 JCS_RGB, /* red/green/blue as specified by the RGB_RED, 0268 RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros */ 0269 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */ 0270 JCS_CMYK, /* C/M/Y/K */ 0271 JCS_YCCK, /* Y/Cb/Cr/K */ 0272 JCS_EXT_RGB, /* red/green/blue */ 0273 JCS_EXT_RGBX, /* red/green/blue/x */ 0274 JCS_EXT_BGR, /* blue/green/red */ 0275 JCS_EXT_BGRX, /* blue/green/red/x */ 0276 JCS_EXT_XBGR, /* x/blue/green/red */ 0277 JCS_EXT_XRGB, /* x/red/green/blue */ 0278 /* When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX, JCS_EXT_XBGR, 0279 or JCS_EXT_XRGB during decompression, the X byte is undefined, and in 0280 order to ensure the best performance, libjpeg-turbo can set that byte to 0281 whatever value it wishes. Use the following colorspace constants to 0282 ensure that the X byte is set to 0xFF, so that it can be interpreted as an 0283 opaque alpha channel. */ 0284 JCS_EXT_RGBA, /* red/green/blue/alpha */ 0285 JCS_EXT_BGRA, /* blue/green/red/alpha */ 0286 JCS_EXT_ABGR, /* alpha/blue/green/red */ 0287 JCS_EXT_ARGB, /* alpha/red/green/blue */ 0288 JCS_RGB565 /* 5-bit red/6-bit green/5-bit blue 0289 [decompression only] */ 0290 } J_COLOR_SPACE; 0291 0292 /* DCT/IDCT algorithm options. */ 0293 0294 typedef enum { 0295 JDCT_ISLOW, /* accurate integer method */ 0296 JDCT_IFAST, /* less accurate integer method [legacy feature] */ 0297 JDCT_FLOAT /* floating-point method [legacy feature] */ 0298 } J_DCT_METHOD; 0299 0300 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */ 0301 #define JDCT_DEFAULT JDCT_ISLOW 0302 #endif 0303 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */ 0304 #define JDCT_FASTEST JDCT_IFAST 0305 #endif 0306 0307 /* Dithering options for decompression. */ 0308 0309 typedef enum { 0310 JDITHER_NONE, /* no dithering */ 0311 JDITHER_ORDERED, /* simple ordered dither */ 0312 JDITHER_FS /* Floyd-Steinberg error diffusion dither */ 0313 } J_DITHER_MODE; 0314 0315 0316 /* Common fields between JPEG compression and decompression master structs. */ 0317 0318 #define jpeg_common_fields \ 0319 struct jpeg_error_mgr *err; /* Error handler module */ \ 0320 struct jpeg_memory_mgr *mem; /* Memory manager module */ \ 0321 struct jpeg_progress_mgr *progress; /* Progress monitor, or NULL if none */ \ 0322 void *client_data; /* Available for use by application */ \ 0323 boolean is_decompressor; /* So common code can tell which is which */ \ 0324 int global_state /* For checking call sequence validity */ 0325 0326 /* Routines that are to be used by both halves of the library are declared 0327 * to receive a pointer to this structure. There are no actual instances of 0328 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct. 0329 */ 0330 struct jpeg_common_struct { 0331 jpeg_common_fields; /* Fields common to both master struct types */ 0332 /* Additional fields follow in an actual jpeg_compress_struct or 0333 * jpeg_decompress_struct. All three structs must agree on these 0334 * initial fields! (This would be a lot cleaner in C++.) 0335 */ 0336 }; 0337 0338 typedef struct jpeg_common_struct *j_common_ptr; 0339 typedef struct jpeg_compress_struct *j_compress_ptr; 0340 typedef struct jpeg_decompress_struct *j_decompress_ptr; 0341 0342 0343 /* Master record for a compression instance */ 0344 0345 struct jpeg_compress_struct { 0346 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */ 0347 0348 /* Destination for compressed data */ 0349 struct jpeg_destination_mgr *dest; 0350 0351 /* Description of source image --- these fields must be filled in by 0352 * outer application before starting compression. in_color_space must 0353 * be correct before you can even call jpeg_set_defaults(). 0354 */ 0355 0356 JDIMENSION image_width; /* input image width */ 0357 JDIMENSION image_height; /* input image height */ 0358 int input_components; /* # of color components in input image */ 0359 J_COLOR_SPACE in_color_space; /* colorspace of input image */ 0360 0361 double input_gamma; /* image gamma of input image */ 0362 0363 /* Compression parameters --- these fields must be set before calling 0364 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to 0365 * initialize everything to reasonable defaults, then changing anything 0366 * the application specifically wants to change. That way you won't get 0367 * burnt when new parameters are added. Also note that there are several 0368 * helper routines to simplify changing parameters. 0369 */ 0370 0371 #if JPEG_LIB_VERSION >= 70 0372 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 0373 0374 JDIMENSION jpeg_width; /* scaled JPEG image width */ 0375 JDIMENSION jpeg_height; /* scaled JPEG image height */ 0376 /* Dimensions of actual JPEG image that will be written to file, 0377 * derived from input dimensions by scaling factors above. 0378 * These fields are computed by jpeg_start_compress(). 0379 * You can also use jpeg_calc_jpeg_dimensions() to determine these values 0380 * in advance of calling jpeg_start_compress(). 0381 */ 0382 #endif 0383 0384 int data_precision; /* bits of precision in image data */ 0385 0386 int num_components; /* # of color components in JPEG image */ 0387 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 0388 0389 jpeg_component_info *comp_info; 0390 /* comp_info[i] describes component that appears i'th in SOF */ 0391 0392 JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS]; 0393 #if JPEG_LIB_VERSION >= 70 0394 int q_scale_factor[NUM_QUANT_TBLS]; 0395 #endif 0396 /* ptrs to coefficient quantization tables, or NULL if not defined, 0397 * and corresponding scale factors (percentage, initialized 100). 0398 */ 0399 0400 JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 0401 JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 0402 /* ptrs to Huffman coding tables, or NULL if not defined */ 0403 0404 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 0405 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 0406 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 0407 0408 int num_scans; /* # of entries in scan_info array */ 0409 const jpeg_scan_info *scan_info; /* script for multi-scan file, or NULL */ 0410 /* The default value of scan_info is NULL, which causes a single-scan 0411 * sequential JPEG file to be emitted. To create a multi-scan file, 0412 * set num_scans and scan_info to point to an array of scan definitions. 0413 */ 0414 0415 boolean raw_data_in; /* TRUE=caller supplies downsampled data */ 0416 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 0417 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */ 0418 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 0419 #if JPEG_LIB_VERSION >= 70 0420 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */ 0421 #endif 0422 int smoothing_factor; /* 1..100, or 0 for no input smoothing */ 0423 J_DCT_METHOD dct_method; /* DCT algorithm selector */ 0424 0425 /* The restart interval can be specified in absolute MCUs by setting 0426 * restart_interval, or in MCU rows by setting restart_in_rows 0427 * (in which case the correct restart_interval will be figured 0428 * for each scan). 0429 */ 0430 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */ 0431 int restart_in_rows; /* if > 0, MCU rows per restart interval */ 0432 0433 /* Parameters controlling emission of special markers. */ 0434 0435 boolean write_JFIF_header; /* should a JFIF marker be written? */ 0436 UINT8 JFIF_major_version; /* What to write for the JFIF version number */ 0437 UINT8 JFIF_minor_version; 0438 /* These three values are not used by the JPEG code, merely copied */ 0439 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */ 0440 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */ 0441 /* ratio is defined by X_density/Y_density even when density_unit=0. */ 0442 UINT8 density_unit; /* JFIF code for pixel size units */ 0443 UINT16 X_density; /* Horizontal pixel density */ 0444 UINT16 Y_density; /* Vertical pixel density */ 0445 boolean write_Adobe_marker; /* should an Adobe marker be written? */ 0446 0447 /* State variable: index of next scanline to be written to 0448 * jpeg_write_scanlines(). Application may use this to control its 0449 * processing loop, e.g., "while (next_scanline < image_height)". 0450 */ 0451 0452 JDIMENSION next_scanline; /* 0 .. image_height-1 */ 0453 0454 /* Remaining fields are known throughout compressor, but generally 0455 * should not be touched by a surrounding application. 0456 */ 0457 0458 /* 0459 * These fields are computed during compression startup 0460 */ 0461 boolean progressive_mode; /* TRUE if scan script uses progressive mode */ 0462 int max_h_samp_factor; /* largest h_samp_factor */ 0463 int max_v_samp_factor; /* largest v_samp_factor */ 0464 0465 #if JPEG_LIB_VERSION >= 70 0466 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 0467 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 0468 #endif 0469 0470 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coefficient or 0471 difference controller */ 0472 /* The coefficient or difference controller receives data in units of MCU 0473 * rows as defined for fully interleaved scans (whether the JPEG file is 0474 * interleaved or not). In lossy mode, there are v_samp_factor * DCTSIZE 0475 * sample rows of each component in an "iMCU" (interleaved MCU) row. In 0476 * lossless mode, total_iMCU_rows is always equal to the image height. 0477 */ 0478 0479 /* 0480 * These fields are valid during any one scan. 0481 * They describe the components and MCUs actually appearing in the scan. 0482 */ 0483 int comps_in_scan; /* # of JPEG components in this scan */ 0484 jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN]; 0485 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 0486 0487 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 0488 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 0489 0490 int blocks_in_MCU; /* # of data units per MCU */ 0491 int MCU_membership[C_MAX_BLOCKS_IN_MCU]; 0492 /* MCU_membership[i] is index in cur_comp_info of component owning */ 0493 /* i'th data unit in an MCU */ 0494 0495 int Ss, Se, Ah, Al; /* progressive/lossless JPEG parameters for 0496 scan */ 0497 0498 #if JPEG_LIB_VERSION >= 80 0499 int block_size; /* the basic DCT block size: 1..16 */ 0500 const int *natural_order; /* natural-order position array */ 0501 int lim_Se; /* min( Se, DCTSIZE2-1 ) */ 0502 #endif 0503 0504 /* 0505 * Links to compression subobjects (methods and private variables of modules) 0506 */ 0507 struct jpeg_comp_master *master; 0508 struct jpeg_c_main_controller *main; 0509 struct jpeg_c_prep_controller *prep; 0510 struct jpeg_c_coef_controller *coef; 0511 struct jpeg_marker_writer *marker; 0512 struct jpeg_color_converter *cconvert; 0513 struct jpeg_downsampler *downsample; 0514 struct jpeg_forward_dct *fdct; 0515 struct jpeg_entropy_encoder *entropy; 0516 jpeg_scan_info *script_space; /* workspace for jpeg_simple_progression */ 0517 int script_space_size; 0518 }; 0519 0520 0521 /* Master record for a decompression instance */ 0522 0523 struct jpeg_decompress_struct { 0524 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */ 0525 0526 /* Source of compressed data */ 0527 struct jpeg_source_mgr *src; 0528 0529 /* Basic description of image --- filled in by jpeg_read_header(). */ 0530 /* Application may inspect these values to decide how to process image. */ 0531 0532 JDIMENSION image_width; /* nominal image width (from SOF marker) */ 0533 JDIMENSION image_height; /* nominal image height */ 0534 int num_components; /* # of color components in JPEG image */ 0535 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 0536 0537 /* Decompression processing parameters --- these fields must be set before 0538 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes 0539 * them to default values. 0540 */ 0541 0542 J_COLOR_SPACE out_color_space; /* colorspace for output */ 0543 0544 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 0545 0546 double output_gamma; /* image gamma wanted in output */ 0547 0548 boolean buffered_image; /* TRUE=multiple output passes */ 0549 boolean raw_data_out; /* TRUE=downsampled data wanted */ 0550 0551 J_DCT_METHOD dct_method; /* IDCT algorithm selector */ 0552 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */ 0553 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */ 0554 0555 boolean quantize_colors; /* TRUE=colormapped output wanted */ 0556 /* the following are ignored if not quantize_colors: */ 0557 J_DITHER_MODE dither_mode; /* type of color dithering to use */ 0558 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */ 0559 int desired_number_of_colors; /* max # colors to use in created colormap */ 0560 /* these are significant only in buffered-image mode: */ 0561 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */ 0562 boolean enable_external_quant;/* enable future use of external colormap */ 0563 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */ 0564 0565 /* Description of actual output image that will be returned to application. 0566 * These fields are computed by jpeg_start_decompress(). 0567 * You can also use jpeg_calc_output_dimensions() to determine these values 0568 * in advance of calling jpeg_start_decompress(). 0569 */ 0570 0571 JDIMENSION output_width; /* scaled image width */ 0572 JDIMENSION output_height; /* scaled image height */ 0573 int out_color_components; /* # of color components in out_color_space */ 0574 int output_components; /* # of color components returned */ 0575 /* output_components is 1 (a colormap index) when quantizing colors; 0576 * otherwise it equals out_color_components. 0577 */ 0578 int rec_outbuf_height; /* min recommended height of scanline buffer */ 0579 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows 0580 * high, space and time will be wasted due to unnecessary data copying. 0581 * Usually rec_outbuf_height will be 1 or 2, at most 4. 0582 */ 0583 0584 /* When quantizing colors, the output colormap is described by these fields. 0585 * The application can supply a colormap by setting colormap non-NULL before 0586 * calling jpeg_start_decompress; otherwise a colormap is created during 0587 * jpeg_start_decompress or jpeg_start_output. 0588 * The map has out_color_components rows and actual_number_of_colors columns. 0589 */ 0590 int actual_number_of_colors; /* number of entries in use */ 0591 JSAMPARRAY colormap; /* The color map as a 2-D pixel array 0592 If data_precision is 12, then this is 0593 actually a J12SAMPARRAY, so callers must 0594 type-cast it in order to read/write 12-bit 0595 samples from/to the array. */ 0596 0597 /* State variables: these variables indicate the progress of decompression. 0598 * The application may examine these but must not modify them. 0599 */ 0600 0601 /* Row index of next scanline to be read from jpeg_read_scanlines(). 0602 * Application may use this to control its processing loop, e.g., 0603 * "while (output_scanline < output_height)". 0604 */ 0605 JDIMENSION output_scanline; /* 0 .. output_height-1 */ 0606 0607 /* Current input scan number and number of iMCU rows completed in scan. 0608 * These indicate the progress of the decompressor input side. 0609 */ 0610 int input_scan_number; /* Number of SOS markers seen so far */ 0611 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */ 0612 0613 /* The "output scan number" is the notional scan being displayed by the 0614 * output side. The decompressor will not allow output scan/row number 0615 * to get ahead of input scan/row, but it can fall arbitrarily far behind. 0616 */ 0617 int output_scan_number; /* Nominal scan number being displayed */ 0618 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */ 0619 0620 /* Current progression status. coef_bits[c][i] indicates the precision 0621 * with which component c's DCT coefficient i (in zigzag order) is known. 0622 * It is -1 when no data has yet been received, otherwise it is the point 0623 * transform (shift) value for the most recent scan of the coefficient 0624 * (thus, 0 at completion of the progression). 0625 * This pointer is NULL when reading a non-progressive file. 0626 */ 0627 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */ 0628 0629 /* Internal JPEG parameters --- the application usually need not look at 0630 * these fields. Note that the decompressor output side may not use 0631 * any parameters that can change between scans. 0632 */ 0633 0634 /* Quantization and Huffman tables are carried forward across input 0635 * datastreams when processing abbreviated JPEG datastreams. 0636 */ 0637 0638 JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS]; 0639 /* ptrs to coefficient quantization tables, or NULL if not defined */ 0640 0641 JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 0642 JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 0643 /* ptrs to Huffman coding tables, or NULL if not defined */ 0644 0645 /* These parameters are never carried across datastreams, since they 0646 * are given in SOF/SOS markers or defined to be reset by SOI. 0647 */ 0648 0649 int data_precision; /* bits of precision in image data */ 0650 0651 jpeg_component_info *comp_info; 0652 /* comp_info[i] describes component that appears i'th in SOF */ 0653 0654 #if JPEG_LIB_VERSION >= 80 0655 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */ 0656 #endif 0657 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */ 0658 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 0659 0660 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 0661 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 0662 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 0663 0664 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */ 0665 0666 /* These fields record data obtained from optional markers recognized by 0667 * the JPEG library. 0668 */ 0669 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */ 0670 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */ 0671 UINT8 JFIF_major_version; /* JFIF version number */ 0672 UINT8 JFIF_minor_version; 0673 UINT8 density_unit; /* JFIF code for pixel size units */ 0674 UINT16 X_density; /* Horizontal pixel density */ 0675 UINT16 Y_density; /* Vertical pixel density */ 0676 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */ 0677 UINT8 Adobe_transform; /* Color transform code from Adobe marker */ 0678 0679 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 0680 0681 /* Aside from the specific data retained from APPn markers known to the 0682 * library, the uninterpreted contents of any or all APPn and COM markers 0683 * can be saved in a list for examination by the application. 0684 */ 0685 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */ 0686 0687 /* Remaining fields are known throughout decompressor, but generally 0688 * should not be touched by a surrounding application. 0689 */ 0690 0691 /* 0692 * These fields are computed during decompression startup 0693 */ 0694 int max_h_samp_factor; /* largest h_samp_factor */ 0695 int max_v_samp_factor; /* largest v_samp_factor */ 0696 0697 #if JPEG_LIB_VERSION >= 70 0698 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 0699 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 0700 #else 0701 int min_DCT_scaled_size; /* smallest DCT_scaled_size of any component */ 0702 #endif 0703 0704 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */ 0705 /* The coefficient or difference controller's input and output progress is 0706 * measured in units of "iMCU" (interleaved MCU) rows. These are the same as 0707 * MCU rows in fully interleaved JPEG scans, but are used whether the scan is 0708 * interleaved or not. In lossy mode, we define an iMCU row as v_samp_factor 0709 * DCT block rows of each component. Therefore, the IDCT output contains 0710 * v_samp_factor*DCT_[v_]scaled_size sample rows of a component per iMCU row. 0711 * In lossless mode, total_iMCU_rows is always equal to the image height. 0712 */ 0713 0714 JSAMPLE *sample_range_limit; /* table for fast range-limiting 0715 If data_precision is 9 to 12, then this is 0716 actually a J12SAMPLE pointer, and if 0717 data_precision is 13 to 16, then this is 0718 actually a J16SAMPLE pointer, so callers 0719 must type-cast it in order to read samples 0720 from the array. */ 0721 0722 /* 0723 * These fields are valid during any one scan. 0724 * They describe the components and MCUs actually appearing in the scan. 0725 * Note that the decompressor output side must not use these fields. 0726 */ 0727 int comps_in_scan; /* # of JPEG components in this scan */ 0728 jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN]; 0729 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 0730 0731 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 0732 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 0733 0734 int blocks_in_MCU; /* # of data units per MCU */ 0735 int MCU_membership[D_MAX_BLOCKS_IN_MCU]; 0736 /* MCU_membership[i] is index in cur_comp_info of component owning */ 0737 /* i'th data unit in an MCU */ 0738 0739 int Ss, Se, Ah, Al; /* progressive/lossless JPEG parameters for 0740 scan */ 0741 0742 #if JPEG_LIB_VERSION >= 80 0743 /* These fields are derived from Se of first SOS marker. 0744 */ 0745 int block_size; /* the basic DCT block size: 1..16 */ 0746 const int *natural_order; /* natural-order position array for entropy decode */ 0747 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */ 0748 #endif 0749 0750 /* This field is shared between entropy decoder and marker parser. 0751 * It is either zero or the code of a JPEG marker that has been 0752 * read from the data source, but has not yet been processed. 0753 */ 0754 int unread_marker; 0755 0756 /* 0757 * Links to decompression subobjects (methods, private variables of modules) 0758 */ 0759 struct jpeg_decomp_master *master; 0760 struct jpeg_d_main_controller *main; 0761 struct jpeg_d_coef_controller *coef; 0762 struct jpeg_d_post_controller *post; 0763 struct jpeg_input_controller *inputctl; 0764 struct jpeg_marker_reader *marker; 0765 struct jpeg_entropy_decoder *entropy; 0766 struct jpeg_inverse_dct *idct; 0767 struct jpeg_upsampler *upsample; 0768 struct jpeg_color_deconverter *cconvert; 0769 struct jpeg_color_quantizer *cquantize; 0770 }; 0771 0772 0773 /* "Object" declarations for JPEG modules that may be supplied or called 0774 * directly by the surrounding application. 0775 * As with all objects in the JPEG library, these structs only define the 0776 * publicly visible methods and state variables of a module. Additional 0777 * private fields may exist after the public ones. 0778 */ 0779 0780 0781 /* Error handler object */ 0782 0783 struct jpeg_error_mgr { 0784 /* Error exit handler: does not return to caller */ 0785 void (*error_exit) (j_common_ptr cinfo); 0786 /* Conditionally emit a trace or warning message */ 0787 void (*emit_message) (j_common_ptr cinfo, int msg_level); 0788 /* Routine that actually outputs a trace or error message */ 0789 void (*output_message) (j_common_ptr cinfo); 0790 /* Format a message string for the most recent JPEG error or message */ 0791 void (*format_message) (j_common_ptr cinfo, char *buffer); 0792 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */ 0793 /* Reset error state variables at start of a new image */ 0794 void (*reset_error_mgr) (j_common_ptr cinfo); 0795 0796 /* The message ID code and any parameters are saved here. 0797 * A message can have one string parameter or up to 8 int parameters. 0798 */ 0799 int msg_code; 0800 #define JMSG_STR_PARM_MAX 80 0801 union { 0802 int i[8]; 0803 char s[JMSG_STR_PARM_MAX]; 0804 } msg_parm; 0805 0806 /* Standard state variables for error facility */ 0807 0808 int trace_level; /* max msg_level that will be displayed */ 0809 0810 /* For recoverable corrupt-data errors, we emit a warning message, 0811 * but keep going unless emit_message chooses to abort. emit_message 0812 * should count warnings in num_warnings. The surrounding application 0813 * can check for bad data by seeing if num_warnings is nonzero at the 0814 * end of processing. 0815 */ 0816 long num_warnings; /* number of corrupt-data warnings */ 0817 0818 /* These fields point to the table(s) of error message strings. 0819 * An application can change the table pointer to switch to a different 0820 * message list (typically, to change the language in which errors are 0821 * reported). Some applications may wish to add additional error codes 0822 * that will be handled by the JPEG library error mechanism; the second 0823 * table pointer is used for this purpose. 0824 * 0825 * First table includes all errors generated by JPEG library itself. 0826 * Error code 0 is reserved for a "no such error string" message. 0827 */ 0828 const char * const *jpeg_message_table; /* Library errors */ 0829 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */ 0830 /* Second table can be added by application (see cjpeg/djpeg for example). 0831 * It contains strings numbered first_addon_message..last_addon_message. 0832 */ 0833 const char * const *addon_message_table; /* Non-library errors */ 0834 int first_addon_message; /* code for first string in addon table */ 0835 int last_addon_message; /* code for last string in addon table */ 0836 }; 0837 0838 0839 /* Progress monitor object */ 0840 0841 struct jpeg_progress_mgr { 0842 void (*progress_monitor) (j_common_ptr cinfo); 0843 0844 long pass_counter; /* work units completed in this pass */ 0845 long pass_limit; /* total number of work units in this pass */ 0846 int completed_passes; /* passes completed so far */ 0847 int total_passes; /* total number of passes expected */ 0848 }; 0849 0850 0851 /* Data destination object for compression */ 0852 0853 struct jpeg_destination_mgr { 0854 JOCTET *next_output_byte; /* => next byte to write in buffer */ 0855 size_t free_in_buffer; /* # of byte spaces remaining in buffer */ 0856 0857 void (*init_destination) (j_compress_ptr cinfo); 0858 boolean (*empty_output_buffer) (j_compress_ptr cinfo); 0859 void (*term_destination) (j_compress_ptr cinfo); 0860 }; 0861 0862 0863 /* Data source object for decompression */ 0864 0865 struct jpeg_source_mgr { 0866 const JOCTET *next_input_byte; /* => next byte to read from buffer */ 0867 size_t bytes_in_buffer; /* # of bytes remaining in buffer */ 0868 0869 void (*init_source) (j_decompress_ptr cinfo); 0870 boolean (*fill_input_buffer) (j_decompress_ptr cinfo); 0871 void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes); 0872 boolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired); 0873 void (*term_source) (j_decompress_ptr cinfo); 0874 }; 0875 0876 0877 /* Memory manager object. 0878 * Allocates "small" objects (a few K total), "large" objects (tens of K), 0879 * and "really big" objects (virtual arrays with backing store if needed). 0880 * The memory manager does not allow individual objects to be freed; rather, 0881 * each created object is assigned to a pool, and whole pools can be freed 0882 * at once. This is faster and more convenient than remembering exactly what 0883 * to free, especially where malloc()/free() are not too speedy. 0884 * NB: alloc routines never return NULL. They exit to error_exit if not 0885 * successful. 0886 */ 0887 0888 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */ 0889 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */ 0890 #define JPOOL_NUMPOOLS 2 0891 0892 typedef struct jvirt_sarray_control *jvirt_sarray_ptr; 0893 typedef struct jvirt_barray_control *jvirt_barray_ptr; 0894 0895 0896 struct jpeg_memory_mgr { 0897 /* Method pointers */ 0898 void *(*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject); 0899 void *(*alloc_large) (j_common_ptr cinfo, int pool_id, 0900 size_t sizeofobject); 0901 /* If cinfo->data_precision is 12 or 16, then this method and the 0902 * access_virt_sarray method actually return a J12SAMPARRAY or a 0903 * J16SAMPARRAY, so callers must type-cast the return value in order to 0904 * read/write 12-bit or 16-bit samples from/to the array. 0905 */ 0906 JSAMPARRAY (*alloc_sarray) (j_common_ptr cinfo, int pool_id, 0907 JDIMENSION samplesperrow, JDIMENSION numrows); 0908 JBLOCKARRAY (*alloc_barray) (j_common_ptr cinfo, int pool_id, 0909 JDIMENSION blocksperrow, JDIMENSION numrows); 0910 jvirt_sarray_ptr (*request_virt_sarray) (j_common_ptr cinfo, int pool_id, 0911 boolean pre_zero, 0912 JDIMENSION samplesperrow, 0913 JDIMENSION numrows, 0914 JDIMENSION maxaccess); 0915 jvirt_barray_ptr (*request_virt_barray) (j_common_ptr cinfo, int pool_id, 0916 boolean pre_zero, 0917 JDIMENSION blocksperrow, 0918 JDIMENSION numrows, 0919 JDIMENSION maxaccess); 0920 void (*realize_virt_arrays) (j_common_ptr cinfo); 0921 JSAMPARRAY (*access_virt_sarray) (j_common_ptr cinfo, jvirt_sarray_ptr ptr, 0922 JDIMENSION start_row, JDIMENSION num_rows, 0923 boolean writable); 0924 JBLOCKARRAY (*access_virt_barray) (j_common_ptr cinfo, jvirt_barray_ptr ptr, 0925 JDIMENSION start_row, JDIMENSION num_rows, 0926 boolean writable); 0927 void (*free_pool) (j_common_ptr cinfo, int pool_id); 0928 void (*self_destruct) (j_common_ptr cinfo); 0929 0930 /* Limit on memory allocation for this JPEG object. (Note that this is 0931 * merely advisory, not a guaranteed maximum; it only affects the space 0932 * used for virtual-array buffers.) May be changed by outer application 0933 * after creating the JPEG object. 0934 */ 0935 long max_memory_to_use; 0936 0937 /* Maximum allocation request accepted by alloc_large. */ 0938 long max_alloc_chunk; 0939 }; 0940 0941 0942 /* Routine signature for application-supplied marker processing methods. 0943 * Need not pass marker code since it is stored in cinfo->unread_marker. 0944 */ 0945 typedef boolean (*jpeg_marker_parser_method) (j_decompress_ptr cinfo); 0946 0947 0948 /* Originally, this macro was used as a way of defining function prototypes 0949 * for both modern compilers as well as older compilers that did not support 0950 * prototype parameters. libjpeg-turbo has never supported these older, 0951 * non-ANSI compilers, but the macro is still included because there is some 0952 * software out there that uses it. 0953 */ 0954 0955 #define JPP(arglist) arglist 0956 0957 0958 /* Default error-management setup */ 0959 EXTERN(struct jpeg_error_mgr *) jpeg_std_error(struct jpeg_error_mgr *err); 0960 0961 /* Initialization of JPEG compression objects. 0962 * jpeg_create_compress() and jpeg_create_decompress() are the exported 0963 * names that applications should call. These expand to calls on 0964 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information 0965 * passed for version mismatch checking. 0966 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx. 0967 */ 0968 #define jpeg_create_compress(cinfo) \ 0969 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \ 0970 (size_t)sizeof(struct jpeg_compress_struct)) 0971 #define jpeg_create_decompress(cinfo) \ 0972 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \ 0973 (size_t)sizeof(struct jpeg_decompress_struct)) 0974 EXTERN(void) jpeg_CreateCompress(j_compress_ptr cinfo, int version, 0975 size_t structsize); 0976 EXTERN(void) jpeg_CreateDecompress(j_decompress_ptr cinfo, int version, 0977 size_t structsize); 0978 /* Destruction of JPEG compression objects */ 0979 EXTERN(void) jpeg_destroy_compress(j_compress_ptr cinfo); 0980 EXTERN(void) jpeg_destroy_decompress(j_decompress_ptr cinfo); 0981 0982 /* Standard data source and destination managers: stdio streams. */ 0983 /* Caller is responsible for opening the file before and closing after. */ 0984 EXTERN(void) jpeg_stdio_dest(j_compress_ptr cinfo, FILE *outfile); 0985 EXTERN(void) jpeg_stdio_src(j_decompress_ptr cinfo, FILE *infile); 0986 0987 /* Data source and destination managers: memory buffers. */ 0988 EXTERN(void) jpeg_mem_dest(j_compress_ptr cinfo, unsigned char **outbuffer, 0989 unsigned long *outsize); 0990 EXTERN(void) jpeg_mem_src(j_decompress_ptr cinfo, 0991 const unsigned char *inbuffer, unsigned long insize); 0992 0993 /* Default parameter setup for compression */ 0994 EXTERN(void) jpeg_set_defaults(j_compress_ptr cinfo); 0995 /* Compression parameter setup aids */ 0996 EXTERN(void) jpeg_set_colorspace(j_compress_ptr cinfo, 0997 J_COLOR_SPACE colorspace); 0998 EXTERN(void) jpeg_default_colorspace(j_compress_ptr cinfo); 0999 EXTERN(void) jpeg_set_quality(j_compress_ptr cinfo, int quality, 1000 boolean force_baseline); 1001 EXTERN(void) jpeg_set_linear_quality(j_compress_ptr cinfo, int scale_factor, 1002 boolean force_baseline); 1003 #if JPEG_LIB_VERSION >= 70 1004 EXTERN(void) jpeg_default_qtables(j_compress_ptr cinfo, 1005 boolean force_baseline); 1006 #endif 1007 EXTERN(void) jpeg_add_quant_table(j_compress_ptr cinfo, int which_tbl, 1008 const unsigned int *basic_table, 1009 int scale_factor, boolean force_baseline); 1010 EXTERN(int) jpeg_quality_scaling(int quality); 1011 EXTERN(void) jpeg_enable_lossless(j_compress_ptr cinfo, 1012 int predictor_selection_value, 1013 int point_transform); 1014 EXTERN(void) jpeg_simple_progression(j_compress_ptr cinfo); 1015 EXTERN(void) jpeg_suppress_tables(j_compress_ptr cinfo, boolean suppress); 1016 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table(j_common_ptr cinfo); 1017 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table(j_common_ptr cinfo); 1018 1019 /* Main entry points for compression */ 1020 EXTERN(void) jpeg_start_compress(j_compress_ptr cinfo, 1021 boolean write_all_tables); 1022 EXTERN(JDIMENSION) jpeg_write_scanlines(j_compress_ptr cinfo, 1023 JSAMPARRAY scanlines, 1024 JDIMENSION num_lines); 1025 EXTERN(JDIMENSION) jpeg12_write_scanlines(j_compress_ptr cinfo, 1026 J12SAMPARRAY scanlines, 1027 JDIMENSION num_lines); 1028 EXTERN(JDIMENSION) jpeg16_write_scanlines(j_compress_ptr cinfo, 1029 J16SAMPARRAY scanlines, 1030 JDIMENSION num_lines); 1031 EXTERN(void) jpeg_finish_compress(j_compress_ptr cinfo); 1032 1033 #if JPEG_LIB_VERSION >= 70 1034 /* Precalculate JPEG dimensions for current compression parameters. */ 1035 EXTERN(void) jpeg_calc_jpeg_dimensions(j_compress_ptr cinfo); 1036 #endif 1037 1038 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */ 1039 EXTERN(JDIMENSION) jpeg_write_raw_data(j_compress_ptr cinfo, JSAMPIMAGE data, 1040 JDIMENSION num_lines); 1041 EXTERN(JDIMENSION) jpeg12_write_raw_data(j_compress_ptr cinfo, 1042 J12SAMPIMAGE data, 1043 JDIMENSION num_lines); 1044 1045 /* Write a special marker. See libjpeg.txt concerning safe usage. */ 1046 EXTERN(void) jpeg_write_marker(j_compress_ptr cinfo, int marker, 1047 const JOCTET *dataptr, unsigned int datalen); 1048 /* Same, but piecemeal. */ 1049 EXTERN(void) jpeg_write_m_header(j_compress_ptr cinfo, int marker, 1050 unsigned int datalen); 1051 EXTERN(void) jpeg_write_m_byte(j_compress_ptr cinfo, int val); 1052 1053 /* Alternate compression function: just write an abbreviated table file */ 1054 EXTERN(void) jpeg_write_tables(j_compress_ptr cinfo); 1055 1056 /* Write ICC profile. See libjpeg.txt for usage information. */ 1057 EXTERN(void) jpeg_write_icc_profile(j_compress_ptr cinfo, 1058 const JOCTET *icc_data_ptr, 1059 unsigned int icc_data_len); 1060 1061 1062 /* Decompression startup: read start of JPEG datastream to see what's there */ 1063 EXTERN(int) jpeg_read_header(j_decompress_ptr cinfo, boolean require_image); 1064 /* Return value is one of: */ 1065 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */ 1066 #define JPEG_HEADER_OK 1 /* Found valid image datastream */ 1067 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */ 1068 /* If you pass require_image = TRUE (normal case), you need not check for 1069 * a TABLES_ONLY return code; an abbreviated file will cause an error exit. 1070 * JPEG_SUSPENDED is only possible if you use a data source module that can 1071 * give a suspension return (the stdio source module doesn't). 1072 */ 1073 1074 /* Main entry points for decompression */ 1075 EXTERN(boolean) jpeg_start_decompress(j_decompress_ptr cinfo); 1076 EXTERN(JDIMENSION) jpeg_read_scanlines(j_decompress_ptr cinfo, 1077 JSAMPARRAY scanlines, 1078 JDIMENSION max_lines); 1079 EXTERN(JDIMENSION) jpeg12_read_scanlines(j_decompress_ptr cinfo, 1080 J12SAMPARRAY scanlines, 1081 JDIMENSION max_lines); 1082 EXTERN(JDIMENSION) jpeg16_read_scanlines(j_decompress_ptr cinfo, 1083 J16SAMPARRAY scanlines, 1084 JDIMENSION max_lines); 1085 EXTERN(JDIMENSION) jpeg_skip_scanlines(j_decompress_ptr cinfo, 1086 JDIMENSION num_lines); 1087 EXTERN(JDIMENSION) jpeg12_skip_scanlines(j_decompress_ptr cinfo, 1088 JDIMENSION num_lines); 1089 EXTERN(void) jpeg_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset, 1090 JDIMENSION *width); 1091 EXTERN(void) jpeg12_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset, 1092 JDIMENSION *width); 1093 EXTERN(boolean) jpeg_finish_decompress(j_decompress_ptr cinfo); 1094 1095 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */ 1096 EXTERN(JDIMENSION) jpeg_read_raw_data(j_decompress_ptr cinfo, JSAMPIMAGE data, 1097 JDIMENSION max_lines); 1098 EXTERN(JDIMENSION) jpeg12_read_raw_data(j_decompress_ptr cinfo, 1099 J12SAMPIMAGE data, 1100 JDIMENSION max_lines); 1101 1102 /* Additional entry points for buffered-image mode. */ 1103 EXTERN(boolean) jpeg_has_multiple_scans(j_decompress_ptr cinfo); 1104 EXTERN(boolean) jpeg_start_output(j_decompress_ptr cinfo, int scan_number); 1105 EXTERN(boolean) jpeg_finish_output(j_decompress_ptr cinfo); 1106 EXTERN(boolean) jpeg_input_complete(j_decompress_ptr cinfo); 1107 EXTERN(void) jpeg_new_colormap(j_decompress_ptr cinfo); 1108 EXTERN(int) jpeg_consume_input(j_decompress_ptr cinfo); 1109 /* Return value is one of: */ 1110 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */ 1111 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */ 1112 #define JPEG_REACHED_EOI 2 /* Reached end of image */ 1113 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */ 1114 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */ 1115 1116 /* Precalculate output dimensions for current decompression parameters. */ 1117 #if JPEG_LIB_VERSION >= 80 1118 EXTERN(void) jpeg_core_output_dimensions(j_decompress_ptr cinfo); 1119 #endif 1120 EXTERN(void) jpeg_calc_output_dimensions(j_decompress_ptr cinfo); 1121 1122 /* Control saving of COM and APPn markers into marker_list. */ 1123 EXTERN(void) jpeg_save_markers(j_decompress_ptr cinfo, int marker_code, 1124 unsigned int length_limit); 1125 1126 /* Install a special processing method for COM or APPn markers. */ 1127 EXTERN(void) jpeg_set_marker_processor(j_decompress_ptr cinfo, 1128 int marker_code, 1129 jpeg_marker_parser_method routine); 1130 1131 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */ 1132 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients(j_decompress_ptr cinfo); 1133 EXTERN(void) jpeg_write_coefficients(j_compress_ptr cinfo, 1134 jvirt_barray_ptr *coef_arrays); 1135 EXTERN(void) jpeg_copy_critical_parameters(j_decompress_ptr srcinfo, 1136 j_compress_ptr dstinfo); 1137 1138 /* If you choose to abort compression or decompression before completing 1139 * jpeg_finish_(de)compress, then you need to clean up to release memory, 1140 * temporary files, etc. You can just call jpeg_destroy_(de)compress 1141 * if you're done with the JPEG object, but if you want to clean it up and 1142 * reuse it, call this: 1143 */ 1144 EXTERN(void) jpeg_abort_compress(j_compress_ptr cinfo); 1145 EXTERN(void) jpeg_abort_decompress(j_decompress_ptr cinfo); 1146 1147 /* Generic versions of jpeg_abort and jpeg_destroy that work on either 1148 * flavor of JPEG object. These may be more convenient in some places. 1149 */ 1150 EXTERN(void) jpeg_abort(j_common_ptr cinfo); 1151 EXTERN(void) jpeg_destroy(j_common_ptr cinfo); 1152 1153 /* Default restart-marker-resync procedure for use by data source modules */ 1154 EXTERN(boolean) jpeg_resync_to_restart(j_decompress_ptr cinfo, int desired); 1155 1156 /* Read ICC profile. See libjpeg.txt for usage information. */ 1157 EXTERN(boolean) jpeg_read_icc_profile(j_decompress_ptr cinfo, 1158 JOCTET **icc_data_ptr, 1159 unsigned int *icc_data_len); 1160 1161 1162 /* These marker codes are exported since applications and data source modules 1163 * are likely to want to use them. 1164 */ 1165 1166 #define JPEG_RST0 0xD0 /* RST0 marker code */ 1167 #define JPEG_EOI 0xD9 /* EOI marker code */ 1168 #define JPEG_APP0 0xE0 /* APP0 marker code */ 1169 #define JPEG_COM 0xFE /* COM marker code */ 1170 1171 1172 /* If we have a brain-damaged compiler that emits warnings (or worse, errors) 1173 * for structure definitions that are never filled in, keep it quiet by 1174 * supplying dummy definitions for the various substructures. 1175 */ 1176 1177 #ifdef INCOMPLETE_TYPES_BROKEN 1178 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */ 1179 struct jvirt_sarray_control { long dummy; }; 1180 struct jvirt_barray_control { long dummy; }; 1181 struct jpeg_comp_master { long dummy; }; 1182 struct jpeg_c_main_controller { long dummy; }; 1183 struct jpeg_c_prep_controller { long dummy; }; 1184 struct jpeg_c_coef_controller { long dummy; }; 1185 struct jpeg_marker_writer { long dummy; }; 1186 struct jpeg_color_converter { long dummy; }; 1187 struct jpeg_downsampler { long dummy; }; 1188 struct jpeg_forward_dct { long dummy; }; 1189 struct jpeg_entropy_encoder { long dummy; }; 1190 struct jpeg_decomp_master { long dummy; }; 1191 struct jpeg_d_main_controller { long dummy; }; 1192 struct jpeg_d_coef_controller { long dummy; }; 1193 struct jpeg_d_post_controller { long dummy; }; 1194 struct jpeg_input_controller { long dummy; }; 1195 struct jpeg_marker_reader { long dummy; }; 1196 struct jpeg_entropy_decoder { long dummy; }; 1197 struct jpeg_inverse_dct { long dummy; }; 1198 struct jpeg_upsampler { long dummy; }; 1199 struct jpeg_color_deconverter { long dummy; }; 1200 struct jpeg_color_quantizer { long dummy; }; 1201 #endif /* JPEG_INTERNALS */ 1202 #endif /* INCOMPLETE_TYPES_BROKEN */ 1203 1204 1205 /* 1206 * The JPEG library modules define JPEG_INTERNALS before including this file. 1207 * The internal structure declarations are read only when that is true. 1208 * Applications using the library should not include jpegint.h, but may wish 1209 * to include jerror.h. 1210 */ 1211 1212 #ifdef JPEG_INTERNALS 1213 #include "jpegint.h" /* fetch private declarations */ 1214 #include "jerror.h" /* fetch error codes too */ 1215 #endif 1216 1217 #ifdef __cplusplus 1218 #ifndef DONT_USE_EXTERN_C 1219 } 1220 #endif 1221 #endif 1222 1223 #endif /* JPEGLIB_H */
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