00001 /* 00002 * jpeglib.h 00003 * 00004 * Copyright (C) 1991-1998, Thomas G. Lane. 00005 * Modified 2002-2010 by Guido Vollbeding. 00006 * This file is part of the Independent JPEG Group's software. 00007 * For conditions of distribution and use, see the accompanying README file. 00008 * 00009 * This file defines the application interface for the JPEG library. 00010 * Most applications using the library need only include this file, 00011 * and perhaps jerror.h if they want to know the exact error codes. 00012 */ 00013 00014 #ifndef JPEGLIB_H 00015 #define JPEGLIB_H 00016 00017 /* 00018 * First we include the configuration files that record how this 00019 * installation of the JPEG library is set up. jconfig.h can be 00020 * generated automatically for many systems. jmorecfg.h contains 00021 * manual configuration options that most people need not worry about. 00022 */ 00023 00024 #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */ 00025 #include "jconfig.h" /* widely used configuration options */ 00026 #endif 00027 #include "jmorecfg.h" /* seldom changed options */ 00028 00029 00030 #ifdef __cplusplus 00031 #ifndef DONT_USE_EXTERN_C 00032 extern "C" { 00033 #endif 00034 #endif 00035 00036 /* Version IDs for the JPEG library. 00037 * Might be useful for tests like "#if JPEG_LIB_VERSION >= 80". 00038 */ 00039 00040 #define JPEG_LIB_VERSION 80 /* Compatibility version 8.0 */ 00041 #define JPEG_LIB_VERSION_MAJOR 8 00042 #define JPEG_LIB_VERSION_MINOR 3 00043 00044 00045 /* Various constants determining the sizes of things. 00046 * All of these are specified by the JPEG standard, so don't change them 00047 * if you want to be compatible. 00048 */ 00049 00050 #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */ 00051 #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */ 00052 #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */ 00053 #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */ 00054 #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */ 00055 #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */ 00056 #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */ 00057 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard; 00058 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU. 00059 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU 00060 * to handle it. We even let you do this from the jconfig.h file. However, 00061 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe 00062 * sometimes emits noncompliant files doesn't mean you should too. 00063 */ 00064 #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */ 00065 #ifndef D_MAX_BLOCKS_IN_MCU 00066 #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */ 00067 #endif 00068 00069 00070 /* Data structures for images (arrays of samples and of DCT coefficients). 00071 * On 80x86 machines, the image arrays are too big for near pointers, 00072 * but the pointer arrays can fit in near memory. 00073 */ 00074 00075 typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */ 00076 typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */ 00077 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */ 00078 00079 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */ 00080 typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */ 00081 typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */ 00082 typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */ 00083 00084 typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */ 00085 00086 00087 /* Types for JPEG compression parameters and working tables. */ 00088 00089 00090 /* DCT coefficient quantization tables. */ 00091 00092 typedef struct { 00093 /* This array gives the coefficient quantizers in natural array order 00094 * (not the zigzag order in which they are stored in a JPEG DQT marker). 00095 * CAUTION: IJG versions prior to v6a kept this array in zigzag order. 00096 */ 00097 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */ 00098 /* This field is used only during compression. It's initialized FALSE when 00099 * the table is created, and set TRUE when it's been output to the file. 00100 * You could suppress output of a table by setting this to TRUE. 00101 * (See jpeg_suppress_tables for an example.) 00102 */ 00103 boolean sent_table; /* TRUE when table has been output */ 00104 } JQUANT_TBL; 00105 00106 00107 /* Huffman coding tables. */ 00108 00109 typedef struct { 00110 /* These two fields directly represent the contents of a JPEG DHT marker */ 00111 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */ 00112 /* length k bits; bits[0] is unused */ 00113 UINT8 huffval[256]; /* The symbols, in order of incr code length */ 00114 /* This field is used only during compression. It's initialized FALSE when 00115 * the table is created, and set TRUE when it's been output to the file. 00116 * You could suppress output of a table by setting this to TRUE. 00117 * (See jpeg_suppress_tables for an example.) 00118 */ 00119 boolean sent_table; /* TRUE when table has been output */ 00120 } JHUFF_TBL; 00121 00122 00123 /* Basic info about one component (color channel). */ 00124 00125 typedef struct { 00126 /* These values are fixed over the whole image. */ 00127 /* For compression, they must be supplied by parameter setup; */ 00128 /* for decompression, they are read from the SOF marker. */ 00129 int component_id; /* identifier for this component (0..255) */ 00130 int component_index; /* its index in SOF or cinfo->comp_info[] */ 00131 int h_samp_factor; /* horizontal sampling factor (1..4) */ 00132 int v_samp_factor; /* vertical sampling factor (1..4) */ 00133 int quant_tbl_no; /* quantization table selector (0..3) */ 00134 /* These values may vary between scans. */ 00135 /* For compression, they must be supplied by parameter setup; */ 00136 /* for decompression, they are read from the SOS marker. */ 00137 /* The decompressor output side may not use these variables. */ 00138 int dc_tbl_no; /* DC entropy table selector (0..3) */ 00139 int ac_tbl_no; /* AC entropy table selector (0..3) */ 00140 00141 /* Remaining fields should be treated as private by applications. */ 00142 00143 /* These values are computed during compression or decompression startup: */ 00144 /* Component's size in DCT blocks. 00145 * Any dummy blocks added to complete an MCU are not counted; therefore 00146 * these values do not depend on whether a scan is interleaved or not. 00147 */ 00148 JDIMENSION width_in_blocks; 00149 JDIMENSION height_in_blocks; 00150 /* Size of a DCT block in samples, 00151 * reflecting any scaling we choose to apply during the DCT step. 00152 * Values from 1 to 16 are supported. 00153 * Note that different components may receive different DCT scalings. 00154 */ 00155 int DCT_h_scaled_size; 00156 int DCT_v_scaled_size; 00157 /* The downsampled dimensions are the component's actual, unpadded number 00158 * of samples at the main buffer (preprocessing/compression interface); 00159 * DCT scaling is included, so 00160 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_h_scaled_size/DCTSIZE) 00161 * and similarly for height. 00162 */ 00163 JDIMENSION downsampled_width; /* actual width in samples */ 00164 JDIMENSION downsampled_height; /* actual height in samples */ 00165 /* This flag is used only for decompression. In cases where some of the 00166 * components will be ignored (eg grayscale output from YCbCr image), 00167 * we can skip most computations for the unused components. 00168 */ 00169 boolean component_needed; /* do we need the value of this component? */ 00170 00171 /* These values are computed before starting a scan of the component. */ 00172 /* The decompressor output side may not use these variables. */ 00173 int MCU_width; /* number of blocks per MCU, horizontally */ 00174 int MCU_height; /* number of blocks per MCU, vertically */ 00175 int MCU_blocks; /* MCU_width * MCU_height */ 00176 int MCU_sample_width; /* MCU width in samples: MCU_width * DCT_h_scaled_size */ 00177 int last_col_width; /* # of non-dummy blocks across in last MCU */ 00178 int last_row_height; /* # of non-dummy blocks down in last MCU */ 00179 00180 /* Saved quantization table for component; NULL if none yet saved. 00181 * See jdinput.c comments about the need for this information. 00182 * This field is currently used only for decompression. 00183 */ 00184 JQUANT_TBL * quant_table; 00185 00186 /* Private per-component storage for DCT or IDCT subsystem. */ 00187 void * dct_table; 00188 } jpeg_component_info; 00189 00190 00191 /* The script for encoding a multiple-scan file is an array of these: */ 00192 00193 typedef struct { 00194 int comps_in_scan; /* number of components encoded in this scan */ 00195 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */ 00196 int Ss, Se; /* progressive JPEG spectral selection parms */ 00197 int Ah, Al; /* progressive JPEG successive approx. parms */ 00198 } jpeg_scan_info; 00199 00200 /* The decompressor can save APPn and COM markers in a list of these: */ 00201 00202 typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr; 00203 00204 struct jpeg_marker_struct { 00205 jpeg_saved_marker_ptr next; /* next in list, or NULL */ 00206 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */ 00207 unsigned int original_length; /* # bytes of data in the file */ 00208 unsigned int data_length; /* # bytes of data saved at data[] */ 00209 JOCTET FAR * data; /* the data contained in the marker */ 00210 /* the marker length word is not counted in data_length or original_length */ 00211 }; 00212 00213 /* Known color spaces. */ 00214 00215 typedef enum { 00216 JCS_UNKNOWN, /* error/unspecified */ 00217 JCS_GRAYSCALE, /* monochrome */ 00218 JCS_RGB, /* red/green/blue */ 00219 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */ 00220 JCS_CMYK, /* C/M/Y/K */ 00221 JCS_YCCK /* Y/Cb/Cr/K */ 00222 } J_COLOR_SPACE; 00223 00224 /* DCT/IDCT algorithm options. */ 00225 00226 typedef enum { 00227 JDCT_ISLOW, /* slow but accurate integer algorithm */ 00228 JDCT_IFAST, /* faster, less accurate integer method */ 00229 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */ 00230 } J_DCT_METHOD; 00231 00232 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */ 00233 #define JDCT_DEFAULT JDCT_ISLOW 00234 #endif 00235 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */ 00236 #define JDCT_FASTEST JDCT_IFAST 00237 #endif 00238 00239 /* Dithering options for decompression. */ 00240 00241 typedef enum { 00242 JDITHER_NONE, /* no dithering */ 00243 JDITHER_ORDERED, /* simple ordered dither */ 00244 JDITHER_FS /* Floyd-Steinberg error diffusion dither */ 00245 } J_DITHER_MODE; 00246 00247 00248 /* Common fields between JPEG compression and decompression master structs. */ 00249 00250 #define jpeg_common_fields \ 00251 struct jpeg_error_mgr * err; /* Error handler module */\ 00252 struct jpeg_memory_mgr * mem; /* Memory manager module */\ 00253 struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\ 00254 void * client_data; /* Available for use by application */\ 00255 boolean is_decompressor; /* So common code can tell which is which */\ 00256 int global_state /* For checking call sequence validity */ 00257 00258 /* Routines that are to be used by both halves of the library are declared 00259 * to receive a pointer to this structure. There are no actual instances of 00260 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct. 00261 */ 00262 struct jpeg_common_struct { 00263 jpeg_common_fields; /* Fields common to both master struct types */ 00264 /* Additional fields follow in an actual jpeg_compress_struct or 00265 * jpeg_decompress_struct. All three structs must agree on these 00266 * initial fields! (This would be a lot cleaner in C++.) 00267 */ 00268 }; 00269 00270 typedef struct jpeg_common_struct * j_common_ptr; 00271 typedef struct jpeg_compress_struct * j_compress_ptr; 00272 typedef struct jpeg_decompress_struct * j_decompress_ptr; 00273 00274 00275 /* Master record for a compression instance */ 00276 00277 struct jpeg_compress_struct { 00278 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */ 00279 00280 /* Destination for compressed data */ 00281 struct jpeg_destination_mgr * dest; 00282 00283 /* Description of source image --- these fields must be filled in by 00284 * outer application before starting compression. in_color_space must 00285 * be correct before you can even call jpeg_set_defaults(). 00286 */ 00287 00288 JDIMENSION image_width; /* input image width */ 00289 JDIMENSION image_height; /* input image height */ 00290 int input_components; /* # of color components in input image */ 00291 J_COLOR_SPACE in_color_space; /* colorspace of input image */ 00292 00293 double input_gamma; /* image gamma of input image */ 00294 00295 /* Compression parameters --- these fields must be set before calling 00296 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to 00297 * initialize everything to reasonable defaults, then changing anything 00298 * the application specifically wants to change. That way you won't get 00299 * burnt when new parameters are added. Also note that there are several 00300 * helper routines to simplify changing parameters. 00301 */ 00302 00303 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 00304 00305 JDIMENSION jpeg_width; /* scaled JPEG image width */ 00306 JDIMENSION jpeg_height; /* scaled JPEG image height */ 00307 /* Dimensions of actual JPEG image that will be written to file, 00308 * derived from input dimensions by scaling factors above. 00309 * These fields are computed by jpeg_start_compress(). 00310 * You can also use jpeg_calc_jpeg_dimensions() to determine these values 00311 * in advance of calling jpeg_start_compress(). 00312 */ 00313 00314 int data_precision; /* bits of precision in image data */ 00315 00316 int num_components; /* # of color components in JPEG image */ 00317 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 00318 00319 jpeg_component_info * comp_info; 00320 /* comp_info[i] describes component that appears i'th in SOF */ 00321 00322 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 00323 int q_scale_factor[NUM_QUANT_TBLS]; 00324 /* ptrs to coefficient quantization tables, or NULL if not defined, 00325 * and corresponding scale factors (percentage, initialized 100). 00326 */ 00327 00328 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 00329 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 00330 /* ptrs to Huffman coding tables, or NULL if not defined */ 00331 00332 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 00333 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 00334 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 00335 00336 int num_scans; /* # of entries in scan_info array */ 00337 const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */ 00338 /* The default value of scan_info is NULL, which causes a single-scan 00339 * sequential JPEG file to be emitted. To create a multi-scan file, 00340 * set num_scans and scan_info to point to an array of scan definitions. 00341 */ 00342 00343 boolean raw_data_in; /* TRUE=caller supplies downsampled data */ 00344 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 00345 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */ 00346 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 00347 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */ 00348 int smoothing_factor; /* 1..100, or 0 for no input smoothing */ 00349 J_DCT_METHOD dct_method; /* DCT algorithm selector */ 00350 00351 /* The restart interval can be specified in absolute MCUs by setting 00352 * restart_interval, or in MCU rows by setting restart_in_rows 00353 * (in which case the correct restart_interval will be figured 00354 * for each scan). 00355 */ 00356 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */ 00357 int restart_in_rows; /* if > 0, MCU rows per restart interval */ 00358 00359 /* Parameters controlling emission of special markers. */ 00360 00361 boolean write_JFIF_header; /* should a JFIF marker be written? */ 00362 UINT8 JFIF_major_version; /* What to write for the JFIF version number */ 00363 UINT8 JFIF_minor_version; 00364 /* These three values are not used by the JPEG code, merely copied */ 00365 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */ 00366 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */ 00367 /* ratio is defined by X_density/Y_density even when density_unit=0. */ 00368 UINT8 density_unit; /* JFIF code for pixel size units */ 00369 UINT16 X_density; /* Horizontal pixel density */ 00370 UINT16 Y_density; /* Vertical pixel density */ 00371 boolean write_Adobe_marker; /* should an Adobe marker be written? */ 00372 00373 /* State variable: index of next scanline to be written to 00374 * jpeg_write_scanlines(). Application may use this to control its 00375 * processing loop, e.g., "while (next_scanline < image_height)". 00376 */ 00377 00378 JDIMENSION next_scanline; /* 0 .. image_height-1 */ 00379 00380 /* Remaining fields are known throughout compressor, but generally 00381 * should not be touched by a surrounding application. 00382 */ 00383 00384 /* 00385 * These fields are computed during compression startup 00386 */ 00387 boolean progressive_mode; /* TRUE if scan script uses progressive mode */ 00388 int max_h_samp_factor; /* largest h_samp_factor */ 00389 int max_v_samp_factor; /* largest v_samp_factor */ 00390 00391 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 00392 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 00393 00394 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */ 00395 /* The coefficient controller receives data in units of MCU rows as defined 00396 * for fully interleaved scans (whether the JPEG file is interleaved or not). 00397 * There are v_samp_factor * DCTSIZE sample rows of each component in an 00398 * "iMCU" (interleaved MCU) row. 00399 */ 00400 00401 /* 00402 * These fields are valid during any one scan. 00403 * They describe the components and MCUs actually appearing in the scan. 00404 */ 00405 int comps_in_scan; /* # of JPEG components in this scan */ 00406 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 00407 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 00408 00409 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 00410 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 00411 00412 int blocks_in_MCU; /* # of DCT blocks per MCU */ 00413 int MCU_membership[C_MAX_BLOCKS_IN_MCU]; 00414 /* MCU_membership[i] is index in cur_comp_info of component owning */ 00415 /* i'th block in an MCU */ 00416 00417 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 00418 00419 int block_size; /* the basic DCT block size: 1..16 */ 00420 const int * natural_order; /* natural-order position array */ 00421 int lim_Se; /* min( Se, DCTSIZE2-1 ) */ 00422 00423 /* 00424 * Links to compression subobjects (methods and private variables of modules) 00425 */ 00426 struct jpeg_comp_master * master; 00427 struct jpeg_c_main_controller * main; 00428 struct jpeg_c_prep_controller * prep; 00429 struct jpeg_c_coef_controller * coef; 00430 struct jpeg_marker_writer * marker; 00431 struct jpeg_color_converter * cconvert; 00432 struct jpeg_downsampler * downsample; 00433 struct jpeg_forward_dct * fdct; 00434 struct jpeg_entropy_encoder * entropy; 00435 jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */ 00436 int script_space_size; 00437 }; 00438 00439 00440 /* Master record for a decompression instance */ 00441 00442 struct jpeg_decompress_struct { 00443 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */ 00444 00445 /* Source of compressed data */ 00446 struct jpeg_source_mgr * src; 00447 00448 /* Basic description of image --- filled in by jpeg_read_header(). */ 00449 /* Application may inspect these values to decide how to process image. */ 00450 00451 JDIMENSION image_width; /* nominal image width (from SOF marker) */ 00452 JDIMENSION image_height; /* nominal image height */ 00453 int num_components; /* # of color components in JPEG image */ 00454 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ 00455 00456 /* Decompression processing parameters --- these fields must be set before 00457 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes 00458 * them to default values. 00459 */ 00460 00461 J_COLOR_SPACE out_color_space; /* colorspace for output */ 00462 00463 unsigned int scale_num, scale_denom; /* fraction by which to scale image */ 00464 00465 double output_gamma; /* image gamma wanted in output */ 00466 00467 boolean buffered_image; /* TRUE=multiple output passes */ 00468 boolean raw_data_out; /* TRUE=downsampled data wanted */ 00469 00470 J_DCT_METHOD dct_method; /* IDCT algorithm selector */ 00471 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */ 00472 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */ 00473 00474 boolean quantize_colors; /* TRUE=colormapped output wanted */ 00475 /* the following are ignored if not quantize_colors: */ 00476 J_DITHER_MODE dither_mode; /* type of color dithering to use */ 00477 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */ 00478 int desired_number_of_colors; /* max # colors to use in created colormap */ 00479 /* these are significant only in buffered-image mode: */ 00480 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */ 00481 boolean enable_external_quant;/* enable future use of external colormap */ 00482 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */ 00483 00484 /* Description of actual output image that will be returned to application. 00485 * These fields are computed by jpeg_start_decompress(). 00486 * You can also use jpeg_calc_output_dimensions() to determine these values 00487 * in advance of calling jpeg_start_decompress(). 00488 */ 00489 00490 JDIMENSION output_width; /* scaled image width */ 00491 JDIMENSION output_height; /* scaled image height */ 00492 int out_color_components; /* # of color components in out_color_space */ 00493 int output_components; /* # of color components returned */ 00494 /* output_components is 1 (a colormap index) when quantizing colors; 00495 * otherwise it equals out_color_components. 00496 */ 00497 int rec_outbuf_height; /* min recommended height of scanline buffer */ 00498 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows 00499 * high, space and time will be wasted due to unnecessary data copying. 00500 * Usually rec_outbuf_height will be 1 or 2, at most 4. 00501 */ 00502 00503 /* When quantizing colors, the output colormap is described by these fields. 00504 * The application can supply a colormap by setting colormap non-NULL before 00505 * calling jpeg_start_decompress; otherwise a colormap is created during 00506 * jpeg_start_decompress or jpeg_start_output. 00507 * The map has out_color_components rows and actual_number_of_colors columns. 00508 */ 00509 int actual_number_of_colors; /* number of entries in use */ 00510 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */ 00511 00512 /* State variables: these variables indicate the progress of decompression. 00513 * The application may examine these but must not modify them. 00514 */ 00515 00516 /* Row index of next scanline to be read from jpeg_read_scanlines(). 00517 * Application may use this to control its processing loop, e.g., 00518 * "while (output_scanline < output_height)". 00519 */ 00520 JDIMENSION output_scanline; /* 0 .. output_height-1 */ 00521 00522 /* Current input scan number and number of iMCU rows completed in scan. 00523 * These indicate the progress of the decompressor input side. 00524 */ 00525 int input_scan_number; /* Number of SOS markers seen so far */ 00526 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */ 00527 00528 /* The "output scan number" is the notional scan being displayed by the 00529 * output side. The decompressor will not allow output scan/row number 00530 * to get ahead of input scan/row, but it can fall arbitrarily far behind. 00531 */ 00532 int output_scan_number; /* Nominal scan number being displayed */ 00533 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */ 00534 00535 /* Current progression status. coef_bits[c][i] indicates the precision 00536 * with which component c's DCT coefficient i (in zigzag order) is known. 00537 * It is -1 when no data has yet been received, otherwise it is the point 00538 * transform (shift) value for the most recent scan of the coefficient 00539 * (thus, 0 at completion of the progression). 00540 * This pointer is NULL when reading a non-progressive file. 00541 */ 00542 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */ 00543 00544 /* Internal JPEG parameters --- the application usually need not look at 00545 * these fields. Note that the decompressor output side may not use 00546 * any parameters that can change between scans. 00547 */ 00548 00549 /* Quantization and Huffman tables are carried forward across input 00550 * datastreams when processing abbreviated JPEG datastreams. 00551 */ 00552 00553 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; 00554 /* ptrs to coefficient quantization tables, or NULL if not defined */ 00555 00556 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; 00557 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; 00558 /* ptrs to Huffman coding tables, or NULL if not defined */ 00559 00560 /* These parameters are never carried across datastreams, since they 00561 * are given in SOF/SOS markers or defined to be reset by SOI. 00562 */ 00563 00564 int data_precision; /* bits of precision in image data */ 00565 00566 jpeg_component_info * comp_info; 00567 /* comp_info[i] describes component that appears i'th in SOF */ 00568 00569 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */ 00570 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */ 00571 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ 00572 00573 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ 00574 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ 00575 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ 00576 00577 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */ 00578 00579 /* These fields record data obtained from optional markers recognized by 00580 * the JPEG library. 00581 */ 00582 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */ 00583 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */ 00584 UINT8 JFIF_major_version; /* JFIF version number */ 00585 UINT8 JFIF_minor_version; 00586 UINT8 density_unit; /* JFIF code for pixel size units */ 00587 UINT16 X_density; /* Horizontal pixel density */ 00588 UINT16 Y_density; /* Vertical pixel density */ 00589 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */ 00590 UINT8 Adobe_transform; /* Color transform code from Adobe marker */ 00591 00592 boolean CCIR601_sampling; /* TRUE=first samples are cosited */ 00593 00594 /* Aside from the specific data retained from APPn markers known to the 00595 * library, the uninterpreted contents of any or all APPn and COM markers 00596 * can be saved in a list for examination by the application. 00597 */ 00598 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */ 00599 00600 /* Remaining fields are known throughout decompressor, but generally 00601 * should not be touched by a surrounding application. 00602 */ 00603 00604 /* 00605 * These fields are computed during decompression startup 00606 */ 00607 int max_h_samp_factor; /* largest h_samp_factor */ 00608 int max_v_samp_factor; /* largest v_samp_factor */ 00609 00610 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */ 00611 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */ 00612 00613 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */ 00614 /* The coefficient controller's input and output progress is measured in 00615 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows 00616 * in fully interleaved JPEG scans, but are used whether the scan is 00617 * interleaved or not. We define an iMCU row as v_samp_factor DCT block 00618 * rows of each component. Therefore, the IDCT output contains 00619 * v_samp_factor*DCT_v_scaled_size sample rows of a component per iMCU row. 00620 */ 00621 00622 JSAMPLE * sample_range_limit; /* table for fast range-limiting */ 00623 00624 /* 00625 * These fields are valid during any one scan. 00626 * They describe the components and MCUs actually appearing in the scan. 00627 * Note that the decompressor output side must not use these fields. 00628 */ 00629 int comps_in_scan; /* # of JPEG components in this scan */ 00630 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; 00631 /* *cur_comp_info[i] describes component that appears i'th in SOS */ 00632 00633 JDIMENSION MCUs_per_row; /* # of MCUs across the image */ 00634 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ 00635 00636 int blocks_in_MCU; /* # of DCT blocks per MCU */ 00637 int MCU_membership[D_MAX_BLOCKS_IN_MCU]; 00638 /* MCU_membership[i] is index in cur_comp_info of component owning */ 00639 /* i'th block in an MCU */ 00640 00641 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ 00642 00643 /* These fields are derived from Se of first SOS marker. 00644 */ 00645 int block_size; /* the basic DCT block size: 1..16 */ 00646 const int * natural_order; /* natural-order position array for entropy decode */ 00647 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */ 00648 00649 /* This field is shared between entropy decoder and marker parser. 00650 * It is either zero or the code of a JPEG marker that has been 00651 * read from the data source, but has not yet been processed. 00652 */ 00653 int unread_marker; 00654 00655 /* 00656 * Links to decompression subobjects (methods, private variables of modules) 00657 */ 00658 struct jpeg_decomp_master * master; 00659 struct jpeg_d_main_controller * main; 00660 struct jpeg_d_coef_controller * coef; 00661 struct jpeg_d_post_controller * post; 00662 struct jpeg_input_controller * inputctl; 00663 struct jpeg_marker_reader * marker; 00664 struct jpeg_entropy_decoder * entropy; 00665 struct jpeg_inverse_dct * idct; 00666 struct jpeg_upsampler * upsample; 00667 struct jpeg_color_deconverter * cconvert; 00668 struct jpeg_color_quantizer * cquantize; 00669 }; 00670 00671 00672 /* "Object" declarations for JPEG modules that may be supplied or called 00673 * directly by the surrounding application. 00674 * As with all objects in the JPEG library, these structs only define the 00675 * publicly visible methods and state variables of a module. Additional 00676 * private fields may exist after the public ones. 00677 */ 00678 00679 00680 /* Error handler object */ 00681 00682 struct jpeg_error_mgr { 00683 /* Error exit handler: does not return to caller */ 00684 JMETHOD(void, error_exit, (j_common_ptr cinfo)); 00685 /* Conditionally emit a trace or warning message */ 00686 JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level)); 00687 /* Routine that actually outputs a trace or error message */ 00688 JMETHOD(void, output_message, (j_common_ptr cinfo)); 00689 /* Format a message string for the most recent JPEG error or message */ 00690 JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer)); 00691 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */ 00692 /* Reset error state variables at start of a new image */ 00693 JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo)); 00694 00695 /* The message ID code and any parameters are saved here. 00696 * A message can have one string parameter or up to 8 int parameters. 00697 */ 00698 int msg_code; 00699 #define JMSG_STR_PARM_MAX 80 00700 union { 00701 int i[8]; 00702 char s[JMSG_STR_PARM_MAX]; 00703 } msg_parm; 00704 00705 /* Standard state variables for error facility */ 00706 00707 int trace_level; /* max msg_level that will be displayed */ 00708 00709 /* For recoverable corrupt-data errors, we emit a warning message, 00710 * but keep going unless emit_message chooses to abort. emit_message 00711 * should count warnings in num_warnings. The surrounding application 00712 * can check for bad data by seeing if num_warnings is nonzero at the 00713 * end of processing. 00714 */ 00715 long num_warnings; /* number of corrupt-data warnings */ 00716 00717 /* These fields point to the table(s) of error message strings. 00718 * An application can change the table pointer to switch to a different 00719 * message list (typically, to change the language in which errors are 00720 * reported). Some applications may wish to add additional error codes 00721 * that will be handled by the JPEG library error mechanism; the second 00722 * table pointer is used for this purpose. 00723 * 00724 * First table includes all errors generated by JPEG library itself. 00725 * Error code 0 is reserved for a "no such error string" message. 00726 */ 00727 const char * const * jpeg_message_table; /* Library errors */ 00728 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */ 00729 /* Second table can be added by application (see cjpeg/djpeg for example). 00730 * It contains strings numbered first_addon_message..last_addon_message. 00731 */ 00732 const char * const * addon_message_table; /* Non-library errors */ 00733 int first_addon_message; /* code for first string in addon table */ 00734 int last_addon_message; /* code for last string in addon table */ 00735 }; 00736 00737 00738 /* Progress monitor object */ 00739 00740 struct jpeg_progress_mgr { 00741 JMETHOD(void, progress_monitor, (j_common_ptr cinfo)); 00742 00743 long pass_counter; /* work units completed in this pass */ 00744 long pass_limit; /* total number of work units in this pass */ 00745 int completed_passes; /* passes completed so far */ 00746 int total_passes; /* total number of passes expected */ 00747 }; 00748 00749 00750 /* Data destination object for compression */ 00751 00752 struct jpeg_destination_mgr { 00753 JOCTET * next_output_byte; /* => next byte to write in buffer */ 00754 size_t free_in_buffer; /* # of byte spaces remaining in buffer */ 00755 00756 JMETHOD(void, init_destination, (j_compress_ptr cinfo)); 00757 JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo)); 00758 JMETHOD(void, term_destination, (j_compress_ptr cinfo)); 00759 }; 00760 00761 00762 /* Data source object for decompression */ 00763 00764 struct jpeg_source_mgr { 00765 const JOCTET * next_input_byte; /* => next byte to read from buffer */ 00766 size_t bytes_in_buffer; /* # of bytes remaining in buffer */ 00767 00768 JMETHOD(void, init_source, (j_decompress_ptr cinfo)); 00769 JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo)); 00770 JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes)); 00771 JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired)); 00772 JMETHOD(void, term_source, (j_decompress_ptr cinfo)); 00773 }; 00774 00775 00776 /* Memory manager object. 00777 * Allocates "small" objects (a few K total), "large" objects (tens of K), 00778 * and "really big" objects (virtual arrays with backing store if needed). 00779 * The memory manager does not allow individual objects to be freed; rather, 00780 * each created object is assigned to a pool, and whole pools can be freed 00781 * at once. This is faster and more convenient than remembering exactly what 00782 * to free, especially where malloc()/free() are not too speedy. 00783 * NB: alloc routines never return NULL. They exit to error_exit if not 00784 * successful. 00785 */ 00786 00787 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */ 00788 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */ 00789 #define JPOOL_NUMPOOLS 2 00790 00791 typedef struct jvirt_sarray_control * jvirt_sarray_ptr; 00792 typedef struct jvirt_barray_control * jvirt_barray_ptr; 00793 00794 00795 struct jpeg_memory_mgr { 00796 /* Method pointers */ 00797 JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id, 00798 size_t sizeofobject)); 00799 JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id, 00800 size_t sizeofobject)); 00801 JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id, 00802 JDIMENSION samplesperrow, 00803 JDIMENSION numrows)); 00804 JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id, 00805 JDIMENSION blocksperrow, 00806 JDIMENSION numrows)); 00807 JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo, 00808 int pool_id, 00809 boolean pre_zero, 00810 JDIMENSION samplesperrow, 00811 JDIMENSION numrows, 00812 JDIMENSION maxaccess)); 00813 JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo, 00814 int pool_id, 00815 boolean pre_zero, 00816 JDIMENSION blocksperrow, 00817 JDIMENSION numrows, 00818 JDIMENSION maxaccess)); 00819 JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo)); 00820 JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo, 00821 jvirt_sarray_ptr ptr, 00822 JDIMENSION start_row, 00823 JDIMENSION num_rows, 00824 boolean writable)); 00825 JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo, 00826 jvirt_barray_ptr ptr, 00827 JDIMENSION start_row, 00828 JDIMENSION num_rows, 00829 boolean writable)); 00830 JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id)); 00831 JMETHOD(void, self_destruct, (j_common_ptr cinfo)); 00832 00833 /* Limit on memory allocation for this JPEG object. (Note that this is 00834 * merely advisory, not a guaranteed maximum; it only affects the space 00835 * used for virtual-array buffers.) May be changed by outer application 00836 * after creating the JPEG object. 00837 */ 00838 long max_memory_to_use; 00839 00840 /* Maximum allocation request accepted by alloc_large. */ 00841 long max_alloc_chunk; 00842 }; 00843 00844 00845 /* Routine signature for application-supplied marker processing methods. 00846 * Need not pass marker code since it is stored in cinfo->unread_marker. 00847 */ 00848 typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo)); 00849 00850 00851 /* Declarations for routines called by application. 00852 * The JPP macro hides prototype parameters from compilers that can't cope. 00853 * Note JPP requires double parentheses. 00854 */ 00855 00856 #ifdef HAVE_PROTOTYPES 00857 #define JPP(arglist) arglist 00858 #else 00859 #define JPP(arglist) () 00860 #endif 00861 00862 00863 /* Short forms of external names for systems with brain-damaged linkers. 00864 * We shorten external names to be unique in the first six letters, which 00865 * is good enough for all known systems. 00866 * (If your compiler itself needs names to be unique in less than 15 00867 * characters, you are out of luck. Get a better compiler.) 00868 */ 00869 00870 #ifdef NEED_SHORT_EXTERNAL_NAMES 00871 #define jpeg_std_error jStdError 00872 #define jpeg_CreateCompress jCreaCompress 00873 #define jpeg_CreateDecompress jCreaDecompress 00874 #define jpeg_destroy_compress jDestCompress 00875 #define jpeg_destroy_decompress jDestDecompress 00876 #define jpeg_stdio_dest jStdDest 00877 #define jpeg_stdio_src jStdSrc 00878 #define jpeg_mem_dest jMemDest 00879 #define jpeg_mem_src jMemSrc 00880 #define jpeg_set_defaults jSetDefaults 00881 #define jpeg_set_colorspace jSetColorspace 00882 #define jpeg_default_colorspace jDefColorspace 00883 #define jpeg_set_quality jSetQuality 00884 #define jpeg_set_linear_quality jSetLQuality 00885 #define jpeg_default_qtables jDefQTables 00886 #define jpeg_add_quant_table jAddQuantTable 00887 #define jpeg_quality_scaling jQualityScaling 00888 #define jpeg_simple_progression jSimProgress 00889 #define jpeg_suppress_tables jSuppressTables 00890 #define jpeg_alloc_quant_table jAlcQTable 00891 #define jpeg_alloc_huff_table jAlcHTable 00892 #define jpeg_start_compress jStrtCompress 00893 #define jpeg_write_scanlines jWrtScanlines 00894 #define jpeg_finish_compress jFinCompress 00895 #define jpeg_calc_jpeg_dimensions jCjpegDimensions 00896 #define jpeg_write_raw_data jWrtRawData 00897 #define jpeg_write_marker jWrtMarker 00898 #define jpeg_write_m_header jWrtMHeader 00899 #define jpeg_write_m_byte jWrtMByte 00900 #define jpeg_write_tables jWrtTables 00901 #define jpeg_read_header jReadHeader 00902 #define jpeg_start_decompress jStrtDecompress 00903 #define jpeg_read_scanlines jReadScanlines 00904 #define jpeg_finish_decompress jFinDecompress 00905 #define jpeg_read_raw_data jReadRawData 00906 #define jpeg_has_multiple_scans jHasMultScn 00907 #define jpeg_start_output jStrtOutput 00908 #define jpeg_finish_output jFinOutput 00909 #define jpeg_input_complete jInComplete 00910 #define jpeg_new_colormap jNewCMap 00911 #define jpeg_consume_input jConsumeInput 00912 #define jpeg_core_output_dimensions jCoreDimensions 00913 #define jpeg_calc_output_dimensions jCalcDimensions 00914 #define jpeg_save_markers jSaveMarkers 00915 #define jpeg_set_marker_processor jSetMarker 00916 #define jpeg_read_coefficients jReadCoefs 00917 #define jpeg_write_coefficients jWrtCoefs 00918 #define jpeg_copy_critical_parameters jCopyCrit 00919 #define jpeg_abort_compress jAbrtCompress 00920 #define jpeg_abort_decompress jAbrtDecompress 00921 #define jpeg_abort jAbort 00922 #define jpeg_destroy jDestroy 00923 #define jpeg_resync_to_restart jResyncRestart 00924 #endif /* NEED_SHORT_EXTERNAL_NAMES */ 00925 00926 00927 /* Default error-management setup */ 00928 EXTERN(struct jpeg_error_mgr *) jpeg_std_error 00929 JPP((struct jpeg_error_mgr * err)); 00930 00931 /* Initialization of JPEG compression objects. 00932 * jpeg_create_compress() and jpeg_create_decompress() are the exported 00933 * names that applications should call. These expand to calls on 00934 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information 00935 * passed for version mismatch checking. 00936 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx. 00937 */ 00938 #define jpeg_create_compress(cinfo) \ 00939 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \ 00940 (size_t) sizeof(struct jpeg_compress_struct)) 00941 #define jpeg_create_decompress(cinfo) \ 00942 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \ 00943 (size_t) sizeof(struct jpeg_decompress_struct)) 00944 EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo, 00945 int version, size_t structsize)); 00946 EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo, 00947 int version, size_t structsize)); 00948 /* Destruction of JPEG compression objects */ 00949 EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo)); 00950 EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo)); 00951 00952 /* Standard data source and destination managers: stdio streams. */ 00953 /* Caller is responsible for opening the file before and closing after. */ 00954 EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile)); 00955 EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile)); 00956 00957 /* Data source and destination managers: memory buffers. */ 00958 EXTERN(void) jpeg_mem_dest JPP((j_compress_ptr cinfo, 00959 unsigned char ** outbuffer, 00960 unsigned long * outsize)); 00961 EXTERN(void) jpeg_mem_src JPP((j_decompress_ptr cinfo, 00962 unsigned char * inbuffer, 00963 unsigned long insize)); 00964 00965 /* Default parameter setup for compression */ 00966 EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo)); 00967 /* Compression parameter setup aids */ 00968 EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo, 00969 J_COLOR_SPACE colorspace)); 00970 EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo)); 00971 EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality, 00972 boolean force_baseline)); 00973 EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo, 00974 int scale_factor, 00975 boolean force_baseline)); 00976 EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo, 00977 boolean force_baseline)); 00978 EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl, 00979 const unsigned int *basic_table, 00980 int scale_factor, 00981 boolean force_baseline)); 00982 EXTERN(int) jpeg_quality_scaling JPP((int quality)); 00983 EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo)); 00984 EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo, 00985 boolean suppress)); 00986 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo)); 00987 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo)); 00988 00989 /* Main entry points for compression */ 00990 EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo, 00991 boolean write_all_tables)); 00992 EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo, 00993 JSAMPARRAY scanlines, 00994 JDIMENSION num_lines)); 00995 EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo)); 00996 00997 /* Precalculate JPEG dimensions for current compression parameters. */ 00998 EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo)); 00999 01000 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */ 01001 EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo, 01002 JSAMPIMAGE data, 01003 JDIMENSION num_lines)); 01004 01005 /* Write a special marker. See libjpeg.txt concerning safe usage. */ 01006 EXTERN(void) jpeg_write_marker 01007 JPP((j_compress_ptr cinfo, int marker, 01008 const JOCTET * dataptr, unsigned int datalen)); 01009 /* Same, but piecemeal. */ 01010 EXTERN(void) jpeg_write_m_header 01011 JPP((j_compress_ptr cinfo, int marker, unsigned int datalen)); 01012 EXTERN(void) jpeg_write_m_byte 01013 JPP((j_compress_ptr cinfo, int val)); 01014 01015 /* Alternate compression function: just write an abbreviated table file */ 01016 EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo)); 01017 01018 /* Decompression startup: read start of JPEG datastream to see what's there */ 01019 EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo, 01020 boolean require_image)); 01021 /* Return value is one of: */ 01022 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */ 01023 #define JPEG_HEADER_OK 1 /* Found valid image datastream */ 01024 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */ 01025 /* If you pass require_image = TRUE (normal case), you need not check for 01026 * a TABLES_ONLY return code; an abbreviated file will cause an error exit. 01027 * JPEG_SUSPENDED is only possible if you use a data source module that can 01028 * give a suspension return (the stdio source module doesn't). 01029 */ 01030 01031 /* Main entry points for decompression */ 01032 EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo)); 01033 EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo, 01034 JSAMPARRAY scanlines, 01035 JDIMENSION max_lines)); 01036 EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo)); 01037 01038 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */ 01039 EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo, 01040 JSAMPIMAGE data, 01041 JDIMENSION max_lines)); 01042 01043 /* Additional entry points for buffered-image mode. */ 01044 EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo)); 01045 EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo, 01046 int scan_number)); 01047 EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo)); 01048 EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo)); 01049 EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo)); 01050 EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo)); 01051 /* Return value is one of: */ 01052 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */ 01053 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */ 01054 #define JPEG_REACHED_EOI 2 /* Reached end of image */ 01055 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */ 01056 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */ 01057 01058 /* Precalculate output dimensions for current decompression parameters. */ 01059 EXTERN(void) jpeg_core_output_dimensions JPP((j_decompress_ptr cinfo)); 01060 EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo)); 01061 01062 /* Control saving of COM and APPn markers into marker_list. */ 01063 EXTERN(void) jpeg_save_markers 01064 JPP((j_decompress_ptr cinfo, int marker_code, 01065 unsigned int length_limit)); 01066 01067 /* Install a special processing method for COM or APPn markers. */ 01068 EXTERN(void) jpeg_set_marker_processor 01069 JPP((j_decompress_ptr cinfo, int marker_code, 01070 jpeg_marker_parser_method routine)); 01071 01072 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */ 01073 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo)); 01074 EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo, 01075 jvirt_barray_ptr * coef_arrays)); 01076 EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo, 01077 j_compress_ptr dstinfo)); 01078 01079 /* If you choose to abort compression or decompression before completing 01080 * jpeg_finish_(de)compress, then you need to clean up to release memory, 01081 * temporary files, etc. You can just call jpeg_destroy_(de)compress 01082 * if you're done with the JPEG object, but if you want to clean it up and 01083 * reuse it, call this: 01084 */ 01085 EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo)); 01086 EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo)); 01087 01088 /* Generic versions of jpeg_abort and jpeg_destroy that work on either 01089 * flavor of JPEG object. These may be more convenient in some places. 01090 */ 01091 EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo)); 01092 EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo)); 01093 01094 /* Default restart-marker-resync procedure for use by data source modules */ 01095 EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo, 01096 int desired)); 01097 01098 01099 /* These marker codes are exported since applications and data source modules 01100 * are likely to want to use them. 01101 */ 01102 01103 #define JPEG_RST0 0xD0 /* RST0 marker code */ 01104 #define JPEG_EOI 0xD9 /* EOI marker code */ 01105 #define JPEG_APP0 0xE0 /* APP0 marker code */ 01106 #define JPEG_COM 0xFE /* COM marker code */ 01107 01108 01109 /* If we have a brain-damaged compiler that emits warnings (or worse, errors) 01110 * for structure definitions that are never filled in, keep it quiet by 01111 * supplying dummy definitions for the various substructures. 01112 */ 01113 01114 #ifdef INCOMPLETE_TYPES_BROKEN 01115 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */ 01116 struct jvirt_sarray_control { long dummy; }; 01117 struct jvirt_barray_control { long dummy; }; 01118 struct jpeg_comp_master { long dummy; }; 01119 struct jpeg_c_main_controller { long dummy; }; 01120 struct jpeg_c_prep_controller { long dummy; }; 01121 struct jpeg_c_coef_controller { long dummy; }; 01122 struct jpeg_marker_writer { long dummy; }; 01123 struct jpeg_color_converter { long dummy; }; 01124 struct jpeg_downsampler { long dummy; }; 01125 struct jpeg_forward_dct { long dummy; }; 01126 struct jpeg_entropy_encoder { long dummy; }; 01127 struct jpeg_decomp_master { long dummy; }; 01128 struct jpeg_d_main_controller { long dummy; }; 01129 struct jpeg_d_coef_controller { long dummy; }; 01130 struct jpeg_d_post_controller { long dummy; }; 01131 struct jpeg_input_controller { long dummy; }; 01132 struct jpeg_marker_reader { long dummy; }; 01133 struct jpeg_entropy_decoder { long dummy; }; 01134 struct jpeg_inverse_dct { long dummy; }; 01135 struct jpeg_upsampler { long dummy; }; 01136 struct jpeg_color_deconverter { long dummy; }; 01137 struct jpeg_color_quantizer { long dummy; }; 01138 #endif /* JPEG_INTERNALS */ 01139 #endif /* INCOMPLETE_TYPES_BROKEN */ 01140 01141 01142 /* 01143 * The JPEG library modules define JPEG_INTERNALS before including this file. 01144 * The internal structure declarations are read only when that is true. 01145 * Applications using the library should not include jpegint.h, but may wish 01146 * to include jerror.h. 01147 */ 01148 01149 #ifdef JPEG_INTERNALS 01150 #include "jpegint.h" /* fetch private declarations */ 01151 #include "jerror.h" /* fetch error codes too */ 01152 #endif 01153 01154 #ifdef __cplusplus 01155 #ifndef DONT_USE_EXTERN_C 01156 } 01157 #endif 01158 #endif 01159 01160 #endif /* JPEGLIB_H */