source: trunk/src/3rdparty/libjpeg/jpeglib.h@ 1147

Last change on this file since 1147 was 846, checked in by Dmitry A. Kuminov, 14 years ago

trunk: Merged in qt 4.7.2 sources from branches/vendor/nokia/qt.
File size: 47.3 KB
Line 
1/*
2 * jpeglib.h
3 *
4 * Copyright (C) 1991-1998, Thomas G. Lane.
5 * Modified 2002-2009 by Guido Vollbeding.
6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file.
8 *
9 * This file defines the application interface for the JPEG library.
10 * Most applications using the library need only include this file,
11 * and perhaps jerror.h if they want to know the exact error codes.
12 */
13
14#ifndef JPEGLIB_H
15#define JPEGLIB_H
16
17/*
18 * First we include the configuration files that record how this
19 * installation of the JPEG library is set up. jconfig.h can be
20 * generated automatically for many systems. jmorecfg.h contains
21 * manual configuration options that most people need not worry about.
22 */
23
24#ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */
25#include "jconfig.h" /* widely used configuration options */
26#endif
27#include "jmorecfg.h" /* seldom changed options */
28
29
30#ifdef __cplusplus
31#ifndef DONT_USE_EXTERN_C
32extern "C" {
33#endif
34#endif
35
36/* Version ID for the JPEG library.
37 * Might be useful for tests like "#if JPEG_LIB_VERSION >= 80".
38 */
39
40#define JPEG_LIB_VERSION 80 /* Version 8.0 */
41
42
43/* Various constants determining the sizes of things.
44 * All of these are specified by the JPEG standard, so don't change them
45 * if you want to be compatible.
46 */
47
48#define DCTSIZE 8 /* The basic DCT block is 8x8 samples */
49#define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
50#define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
51#define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
52#define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
53#define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
54#define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
55/* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
56 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
57 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
58 * to handle it. We even let you do this from the jconfig.h file. However,
59 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
60 * sometimes emits noncompliant files doesn't mean you should too.
61 */
62#define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */
63#ifndef D_MAX_BLOCKS_IN_MCU
64#define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */
65#endif
66
67
68/* Data structures for images (arrays of samples and of DCT coefficients).
69 * On 80x86 machines, the image arrays are too big for near pointers,
70 * but the pointer arrays can fit in near memory.
71 */
72
73typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */
74typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */
75typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
76
77typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
78typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */
79typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
80typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
81
82typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */
83
84
85/* Types for JPEG compression parameters and working tables. */
86
87
88/* DCT coefficient quantization tables. */
89
90typedef struct {
91 /* This array gives the coefficient quantizers in natural array order
92 * (not the zigzag order in which they are stored in a JPEG DQT marker).
93 * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
94 */
95 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */
96 /* This field is used only during compression. It's initialized FALSE when
97 * the table is created, and set TRUE when it's been output to the file.
98 * You could suppress output of a table by setting this to TRUE.
99 * (See jpeg_suppress_tables for an example.)
100 */
101 boolean sent_table; /* TRUE when table has been output */
102} JQUANT_TBL;
103
104
105/* Huffman coding tables. */
106
107typedef struct {
108 /* These two fields directly represent the contents of a JPEG DHT marker */
109 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */
110 /* length k bits; bits[0] is unused */
111 UINT8 huffval[256]; /* The symbols, in order of incr code length */
112 /* This field is used only during compression. It's initialized FALSE when
113 * the table is created, and set TRUE when it's been output to the file.
114 * You could suppress output of a table by setting this to TRUE.
115 * (See jpeg_suppress_tables for an example.)
116 */
117 boolean sent_table; /* TRUE when table has been output */
118} JHUFF_TBL;
119
120
121/* Basic info about one component (color channel). */
122
123typedef struct {
124 /* These values are fixed over the whole image. */
125 /* For compression, they must be supplied by parameter setup; */
126 /* for decompression, they are read from the SOF marker. */
127 int component_id; /* identifier for this component (0..255) */
128 int component_index; /* its index in SOF or cinfo->comp_info[] */
129 int h_samp_factor; /* horizontal sampling factor (1..4) */
130 int v_samp_factor; /* vertical sampling factor (1..4) */
131 int quant_tbl_no; /* quantization table selector (0..3) */
132 /* These values may vary between scans. */
133 /* For compression, they must be supplied by parameter setup; */
134 /* for decompression, they are read from the SOS marker. */
135 /* The decompressor output side may not use these variables. */
136 int dc_tbl_no; /* DC entropy table selector (0..3) */
137 int ac_tbl_no; /* AC entropy table selector (0..3) */
138
139 /* Remaining fields should be treated as private by applications. */
140
141 /* These values are computed during compression or decompression startup: */
142 /* Component's size in DCT blocks.
143 * Any dummy blocks added to complete an MCU are not counted; therefore
144 * these values do not depend on whether a scan is interleaved or not.
145 */
146 JDIMENSION width_in_blocks;
147 JDIMENSION height_in_blocks;
148 /* Size of a DCT block in samples,
149 * reflecting any scaling we choose to apply during the DCT step.
150 * Values from 1 to 16 are supported.
151 * Note that different components may receive different DCT scalings.
152 */
153 int DCT_h_scaled_size;
154 int DCT_v_scaled_size;
155 /* The downsampled dimensions are the component's actual, unpadded number
156 * of samples at the main buffer (preprocessing/compression interface);
157 * DCT scaling is included, so
158 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_h_scaled_size/DCTSIZE)
159 * and similarly for height.
160 */
161 JDIMENSION downsampled_width; /* actual width in samples */
162 JDIMENSION downsampled_height; /* actual height in samples */
163 /* This flag is used only for decompression. In cases where some of the
164 * components will be ignored (eg grayscale output from YCbCr image),
165 * we can skip most computations for the unused components.
166 */
167 boolean component_needed; /* do we need the value of this component? */
168
169 /* These values are computed before starting a scan of the component. */
170 /* The decompressor output side may not use these variables. */
171 int MCU_width; /* number of blocks per MCU, horizontally */
172 int MCU_height; /* number of blocks per MCU, vertically */
173 int MCU_blocks; /* MCU_width * MCU_height */
174 int MCU_sample_width; /* MCU width in samples: MCU_width * DCT_h_scaled_size */
175 int last_col_width; /* # of non-dummy blocks across in last MCU */
176 int last_row_height; /* # of non-dummy blocks down in last MCU */
177
178 /* Saved quantization table for component; NULL if none yet saved.
179 * See jdinput.c comments about the need for this information.
180 * This field is currently used only for decompression.
181 */
182 JQUANT_TBL * quant_table;
183
184 /* Private per-component storage for DCT or IDCT subsystem. */
185 void * dct_table;
186} jpeg_component_info;
187
188
189/* The script for encoding a multiple-scan file is an array of these: */
190
191typedef struct {
192 int comps_in_scan; /* number of components encoded in this scan */
193 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
194 int Ss, Se; /* progressive JPEG spectral selection parms */
195 int Ah, Al; /* progressive JPEG successive approx. parms */
196} jpeg_scan_info;
197
198/* The decompressor can save APPn and COM markers in a list of these: */
199
200typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr;
201
202struct jpeg_marker_struct {
203 jpeg_saved_marker_ptr next; /* next in list, or NULL */
204 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */
205 unsigned int original_length; /* # bytes of data in the file */
206 unsigned int data_length; /* # bytes of data saved at data[] */
207 JOCTET FAR * data; /* the data contained in the marker */
208 /* the marker length word is not counted in data_length or original_length */
209};
210
211/* Known color spaces. */
212
213typedef enum {
214 JCS_UNKNOWN, /* error/unspecified */
215 JCS_GRAYSCALE, /* monochrome */
216 JCS_RGB, /* red/green/blue */
217 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */
218 JCS_CMYK, /* C/M/Y/K */
219 JCS_YCCK /* Y/Cb/Cr/K */
220} J_COLOR_SPACE;
221
222/* DCT/IDCT algorithm options. */
223
224typedef enum {
225 JDCT_ISLOW, /* slow but accurate integer algorithm */
226 JDCT_IFAST, /* faster, less accurate integer method */
227 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */
228} J_DCT_METHOD;
229
230#ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
231#define JDCT_DEFAULT JDCT_ISLOW
232#endif
233#ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
234#define JDCT_FASTEST JDCT_IFAST
235#endif
236
237/* Dithering options for decompression. */
238
239typedef enum {
240 JDITHER_NONE, /* no dithering */
241 JDITHER_ORDERED, /* simple ordered dither */
242 JDITHER_FS /* Floyd-Steinberg error diffusion dither */
243} J_DITHER_MODE;
244
245
246/* Common fields between JPEG compression and decompression master structs. */
247
248#define jpeg_common_fields \
249 struct jpeg_error_mgr * err; /* Error handler module */\
250 struct jpeg_memory_mgr * mem; /* Memory manager module */\
251 struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
252 void * client_data; /* Available for use by application */\
253 boolean is_decompressor; /* So common code can tell which is which */\
254 int global_state /* For checking call sequence validity */
255
256/* Routines that are to be used by both halves of the library are declared
257 * to receive a pointer to this structure. There are no actual instances of
258 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
259 */
260struct jpeg_common_struct {
261 jpeg_common_fields; /* Fields common to both master struct types */
262 /* Additional fields follow in an actual jpeg_compress_struct or
263 * jpeg_decompress_struct. All three structs must agree on these
264 * initial fields! (This would be a lot cleaner in C++.)
265 */
266};
267
268typedef struct jpeg_common_struct * j_common_ptr;
269typedef struct jpeg_compress_struct * j_compress_ptr;
270typedef struct jpeg_decompress_struct * j_decompress_ptr;
271
272
273/* Master record for a compression instance */
274
275struct jpeg_compress_struct {
276 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */
277
278 /* Destination for compressed data */
279 struct jpeg_destination_mgr * dest;
280
281 /* Description of source image --- these fields must be filled in by
282 * outer application before starting compression. in_color_space must
283 * be correct before you can even call jpeg_set_defaults().
284 */
285
286 JDIMENSION image_width; /* input image width */
287 JDIMENSION image_height; /* input image height */
288 int input_components; /* # of color components in input image */
289 J_COLOR_SPACE in_color_space; /* colorspace of input image */
290
291 double input_gamma; /* image gamma of input image */
292
293 /* Compression parameters --- these fields must be set before calling
294 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
295 * initialize everything to reasonable defaults, then changing anything
296 * the application specifically wants to change. That way you won't get
297 * burnt when new parameters are added. Also note that there are several
298 * helper routines to simplify changing parameters.
299 */
300
301 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
302
303 JDIMENSION jpeg_width; /* scaled JPEG image width */
304 JDIMENSION jpeg_height; /* scaled JPEG image height */
305 /* Dimensions of actual JPEG image that will be written to file,
306 * derived from input dimensions by scaling factors above.
307 * These fields are computed by jpeg_start_compress().
308 * You can also use jpeg_calc_jpeg_dimensions() to determine these values
309 * in advance of calling jpeg_start_compress().
310 */
311
312 int data_precision; /* bits of precision in image data */
313
314 int num_components; /* # of color components in JPEG image */
315 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
316
317 jpeg_component_info * comp_info;
318 /* comp_info[i] describes component that appears i'th in SOF */
319
320 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
321 int q_scale_factor[NUM_QUANT_TBLS];
322 /* ptrs to coefficient quantization tables, or NULL if not defined,
323 * and corresponding scale factors (percentage, initialized 100).
324 */
325
326 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
327 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
328 /* ptrs to Huffman coding tables, or NULL if not defined */
329
330 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
331 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
332 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
333
334 int num_scans; /* # of entries in scan_info array */
335 const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */
336 /* The default value of scan_info is NULL, which causes a single-scan
337 * sequential JPEG file to be emitted. To create a multi-scan file,
338 * set num_scans and scan_info to point to an array of scan definitions.
339 */
340
341 boolean raw_data_in; /* TRUE=caller supplies downsampled data */
342 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
343 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */
344 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
345 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
346 int smoothing_factor; /* 1..100, or 0 for no input smoothing */
347 J_DCT_METHOD dct_method; /* DCT algorithm selector */
348
349 /* The restart interval can be specified in absolute MCUs by setting
350 * restart_interval, or in MCU rows by setting restart_in_rows
351 * (in which case the correct restart_interval will be figured
352 * for each scan).
353 */
354 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
355 int restart_in_rows; /* if > 0, MCU rows per restart interval */
356
357 /* Parameters controlling emission of special markers. */
358
359 boolean write_JFIF_header; /* should a JFIF marker be written? */
360 UINT8 JFIF_major_version; /* What to write for the JFIF version number */
361 UINT8 JFIF_minor_version;
362 /* These three values are not used by the JPEG code, merely copied */
363 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
364 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
365 /* ratio is defined by X_density/Y_density even when density_unit=0. */
366 UINT8 density_unit; /* JFIF code for pixel size units */
367 UINT16 X_density; /* Horizontal pixel density */
368 UINT16 Y_density; /* Vertical pixel density */
369 boolean write_Adobe_marker; /* should an Adobe marker be written? */
370
371 /* State variable: index of next scanline to be written to
372 * jpeg_write_scanlines(). Application may use this to control its
373 * processing loop, e.g., "while (next_scanline < image_height)".
374 */
375
376 JDIMENSION next_scanline; /* 0 .. image_height-1 */
377
378 /* Remaining fields are known throughout compressor, but generally
379 * should not be touched by a surrounding application.
380 */
381
382 /*
383 * These fields are computed during compression startup
384 */
385 boolean progressive_mode; /* TRUE if scan script uses progressive mode */
386 int max_h_samp_factor; /* largest h_samp_factor */
387 int max_v_samp_factor; /* largest v_samp_factor */
388
389 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
390 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
391
392 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */
393 /* The coefficient controller receives data in units of MCU rows as defined
394 * for fully interleaved scans (whether the JPEG file is interleaved or not).
395 * There are v_samp_factor * DCTSIZE sample rows of each component in an
396 * "iMCU" (interleaved MCU) row.
397 */
398
399 /*
400 * These fields are valid during any one scan.
401 * They describe the components and MCUs actually appearing in the scan.
402 */
403 int comps_in_scan; /* # of JPEG components in this scan */
404 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
405 /* *cur_comp_info[i] describes component that appears i'th in SOS */
406
407 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
408 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
409
410 int blocks_in_MCU; /* # of DCT blocks per MCU */
411 int MCU_membership[C_MAX_BLOCKS_IN_MCU];
412 /* MCU_membership[i] is index in cur_comp_info of component owning */
413 /* i'th block in an MCU */
414
415 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
416
417 int block_size; /* the basic DCT block size: 1..16 */
418 const int * natural_order; /* natural-order position array */
419 int lim_Se; /* min( Se, DCTSIZE2-1 ) */
420
421 /*
422 * Links to compression subobjects (methods and private variables of modules)
423 */
424 struct jpeg_comp_master * master;
425 struct jpeg_c_main_controller * main;
426 struct jpeg_c_prep_controller * prep;
427 struct jpeg_c_coef_controller * coef;
428 struct jpeg_marker_writer * marker;
429 struct jpeg_color_converter * cconvert;
430 struct jpeg_downsampler * downsample;
431 struct jpeg_forward_dct * fdct;
432 struct jpeg_entropy_encoder * entropy;
433 jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */
434 int script_space_size;
435};
436
437
438/* Master record for a decompression instance */
439
440struct jpeg_decompress_struct {
441 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
442
443 /* Source of compressed data */
444 struct jpeg_source_mgr * src;
445
446 /* Basic description of image --- filled in by jpeg_read_header(). */
447 /* Application may inspect these values to decide how to process image. */
448
449 JDIMENSION image_width; /* nominal image width (from SOF marker) */
450 JDIMENSION image_height; /* nominal image height */
451 int num_components; /* # of color components in JPEG image */
452 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
453
454 /* Decompression processing parameters --- these fields must be set before
455 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
456 * them to default values.
457 */
458
459 J_COLOR_SPACE out_color_space; /* colorspace for output */
460
461 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
462
463 double output_gamma; /* image gamma wanted in output */
464
465 boolean buffered_image; /* TRUE=multiple output passes */
466 boolean raw_data_out; /* TRUE=downsampled data wanted */
467
468 J_DCT_METHOD dct_method; /* IDCT algorithm selector */
469 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
470 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
471
472 boolean quantize_colors; /* TRUE=colormapped output wanted */
473 /* the following are ignored if not quantize_colors: */
474 J_DITHER_MODE dither_mode; /* type of color dithering to use */
475 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
476 int desired_number_of_colors; /* max # colors to use in created colormap */
477 /* these are significant only in buffered-image mode: */
478 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
479 boolean enable_external_quant;/* enable future use of external colormap */
480 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
481
482 /* Description of actual output image that will be returned to application.
483 * These fields are computed by jpeg_start_decompress().
484 * You can also use jpeg_calc_output_dimensions() to determine these values
485 * in advance of calling jpeg_start_decompress().
486 */
487
488 JDIMENSION output_width; /* scaled image width */
489 JDIMENSION output_height; /* scaled image height */
490 int out_color_components; /* # of color components in out_color_space */
491 int output_components; /* # of color components returned */
492 /* output_components is 1 (a colormap index) when quantizing colors;
493 * otherwise it equals out_color_components.
494 */
495 int rec_outbuf_height; /* min recommended height of scanline buffer */
496 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
497 * high, space and time will be wasted due to unnecessary data copying.
498 * Usually rec_outbuf_height will be 1 or 2, at most 4.
499 */
500
501 /* When quantizing colors, the output colormap is described by these fields.
502 * The application can supply a colormap by setting colormap non-NULL before
503 * calling jpeg_start_decompress; otherwise a colormap is created during
504 * jpeg_start_decompress or jpeg_start_output.
505 * The map has out_color_components rows and actual_number_of_colors columns.
506 */
507 int actual_number_of_colors; /* number of entries in use */
508 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */
509
510 /* State variables: these variables indicate the progress of decompression.
511 * The application may examine these but must not modify them.
512 */
513
514 /* Row index of next scanline to be read from jpeg_read_scanlines().
515 * Application may use this to control its processing loop, e.g.,
516 * "while (output_scanline < output_height)".
517 */
518 JDIMENSION output_scanline; /* 0 .. output_height-1 */
519
520 /* Current input scan number and number of iMCU rows completed in scan.
521 * These indicate the progress of the decompressor input side.
522 */
523 int input_scan_number; /* Number of SOS markers seen so far */
524 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
525
526 /* The "output scan number" is the notional scan being displayed by the
527 * output side. The decompressor will not allow output scan/row number
528 * to get ahead of input scan/row, but it can fall arbitrarily far behind.
529 */
530 int output_scan_number; /* Nominal scan number being displayed */
531 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
532
533 /* Current progression status. coef_bits[c][i] indicates the precision
534 * with which component c's DCT coefficient i (in zigzag order) is known.
535 * It is -1 when no data has yet been received, otherwise it is the point
536 * transform (shift) value for the most recent scan of the coefficient
537 * (thus, 0 at completion of the progression).
538 * This pointer is NULL when reading a non-progressive file.
539 */
540 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
541
542 /* Internal JPEG parameters --- the application usually need not look at
543 * these fields. Note that the decompressor output side may not use
544 * any parameters that can change between scans.
545 */
546
547 /* Quantization and Huffman tables are carried forward across input
548 * datastreams when processing abbreviated JPEG datastreams.
549 */
550
551 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
552 /* ptrs to coefficient quantization tables, or NULL if not defined */
553
554 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
555 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
556 /* ptrs to Huffman coding tables, or NULL if not defined */
557
558 /* These parameters are never carried across datastreams, since they
559 * are given in SOF/SOS markers or defined to be reset by SOI.
560 */
561
562 int data_precision; /* bits of precision in image data */
563
564 jpeg_component_info * comp_info;
565 /* comp_info[i] describes component that appears i'th in SOF */
566
567 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */
568 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
569 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
570
571 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
572 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
573 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
574
575 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
576
577 /* These fields record data obtained from optional markers recognized by
578 * the JPEG library.
579 */
580 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
581 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
582 UINT8 JFIF_major_version; /* JFIF version number */
583 UINT8 JFIF_minor_version;
584 UINT8 density_unit; /* JFIF code for pixel size units */
585 UINT16 X_density; /* Horizontal pixel density */
586 UINT16 Y_density; /* Vertical pixel density */
587 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
588 UINT8 Adobe_transform; /* Color transform code from Adobe marker */
589
590 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
591
592 /* Aside from the specific data retained from APPn markers known to the
593 * library, the uninterpreted contents of any or all APPn and COM markers
594 * can be saved in a list for examination by the application.
595 */
596 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
597
598 /* Remaining fields are known throughout decompressor, but generally
599 * should not be touched by a surrounding application.
600 */
601
602 /*
603 * These fields are computed during decompression startup
604 */
605 int max_h_samp_factor; /* largest h_samp_factor */
606 int max_v_samp_factor; /* largest v_samp_factor */
607
608 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
609 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
610
611 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
612 /* The coefficient controller's input and output progress is measured in
613 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
614 * in fully interleaved JPEG scans, but are used whether the scan is
615 * interleaved or not. We define an iMCU row as v_samp_factor DCT block
616 * rows of each component. Therefore, the IDCT output contains
617 * v_samp_factor*DCT_v_scaled_size sample rows of a component per iMCU row.
618 */
619
620 JSAMPLE * sample_range_limit; /* table for fast range-limiting */
621
622 /*
623 * These fields are valid during any one scan.
624 * They describe the components and MCUs actually appearing in the scan.
625 * Note that the decompressor output side must not use these fields.
626 */
627 int comps_in_scan; /* # of JPEG components in this scan */
628 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
629 /* *cur_comp_info[i] describes component that appears i'th in SOS */
630
631 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
632 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
633
634 int blocks_in_MCU; /* # of DCT blocks per MCU */
635 int MCU_membership[D_MAX_BLOCKS_IN_MCU];
636 /* MCU_membership[i] is index in cur_comp_info of component owning */
637 /* i'th block in an MCU */
638
639 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
640
641 /* These fields are derived from Se of first SOS marker.
642 */
643 int block_size; /* the basic DCT block size: 1..16 */
644 const int * natural_order; /* natural-order position array for entropy decode */
645 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */
646
647 /* This field is shared between entropy decoder and marker parser.
648 * It is either zero or the code of a JPEG marker that has been
649 * read from the data source, but has not yet been processed.
650 */
651 int unread_marker;
652
653 /*
654 * Links to decompression subobjects (methods, private variables of modules)
655 */
656 struct jpeg_decomp_master * master;
657 struct jpeg_d_main_controller * main;
658 struct jpeg_d_coef_controller * coef;
659 struct jpeg_d_post_controller * post;
660 struct jpeg_input_controller * inputctl;
661 struct jpeg_marker_reader * marker;
662 struct jpeg_entropy_decoder * entropy;
663 struct jpeg_inverse_dct * idct;
664 struct jpeg_upsampler * upsample;
665 struct jpeg_color_deconverter * cconvert;
666 struct jpeg_color_quantizer * cquantize;
667};
668
669
670/* "Object" declarations for JPEG modules that may be supplied or called
671 * directly by the surrounding application.
672 * As with all objects in the JPEG library, these structs only define the
673 * publicly visible methods and state variables of a module. Additional
674 * private fields may exist after the public ones.
675 */
676
677
678/* Error handler object */
679
680struct jpeg_error_mgr {
681 /* Error exit handler: does not return to caller */
682 JMETHOD(void, error_exit, (j_common_ptr cinfo));
683 /* Conditionally emit a trace or warning message */
684 JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
685 /* Routine that actually outputs a trace or error message */
686 JMETHOD(void, output_message, (j_common_ptr cinfo));
687 /* Format a message string for the most recent JPEG error or message */
688 JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
689#define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
690 /* Reset error state variables at start of a new image */
691 JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
692
693 /* The message ID code and any parameters are saved here.
694 * A message can have one string parameter or up to 8 int parameters.
695 */
696 int msg_code;
697#define JMSG_STR_PARM_MAX 80
698 union {
699 int i[8];
700 char s[JMSG_STR_PARM_MAX];
701 } msg_parm;
702
703 /* Standard state variables for error facility */
704
705 int trace_level; /* max msg_level that will be displayed */
706
707 /* For recoverable corrupt-data errors, we emit a warning message,
708 * but keep going unless emit_message chooses to abort. emit_message
709 * should count warnings in num_warnings. The surrounding application
710 * can check for bad data by seeing if num_warnings is nonzero at the
711 * end of processing.
712 */
713 long num_warnings; /* number of corrupt-data warnings */
714
715 /* These fields point to the table(s) of error message strings.
716 * An application can change the table pointer to switch to a different
717 * message list (typically, to change the language in which errors are
718 * reported). Some applications may wish to add additional error codes
719 * that will be handled by the JPEG library error mechanism; the second
720 * table pointer is used for this purpose.
721 *
722 * First table includes all errors generated by JPEG library itself.
723 * Error code 0 is reserved for a "no such error string" message.
724 */
725 const char * const * jpeg_message_table; /* Library errors */
726 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
727 /* Second table can be added by application (see cjpeg/djpeg for example).
728 * It contains strings numbered first_addon_message..last_addon_message.
729 */
730 const char * const * addon_message_table; /* Non-library errors */
731 int first_addon_message; /* code for first string in addon table */
732 int last_addon_message; /* code for last string in addon table */
733};
734
735
736/* Progress monitor object */
737
738struct jpeg_progress_mgr {
739 JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
740
741 long pass_counter; /* work units completed in this pass */
742 long pass_limit; /* total number of work units in this pass */
743 int completed_passes; /* passes completed so far */
744 int total_passes; /* total number of passes expected */
745};
746
747
748/* Data destination object for compression */
749
750struct jpeg_destination_mgr {
751 JOCTET * next_output_byte; /* => next byte to write in buffer */
752 size_t free_in_buffer; /* # of byte spaces remaining in buffer */
753
754 JMETHOD(void, init_destination, (j_compress_ptr cinfo));
755 JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
756 JMETHOD(void, term_destination, (j_compress_ptr cinfo));
757};
758
759
760/* Data source object for decompression */
761
762struct jpeg_source_mgr {
763 const JOCTET * next_input_byte; /* => next byte to read from buffer */
764 size_t bytes_in_buffer; /* # of bytes remaining in buffer */
765
766 JMETHOD(void, init_source, (j_decompress_ptr cinfo));
767 JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
768 JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
769 JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
770 JMETHOD(void, term_source, (j_decompress_ptr cinfo));
771};
772
773
774/* Memory manager object.
775 * Allocates "small" objects (a few K total), "large" objects (tens of K),
776 * and "really big" objects (virtual arrays with backing store if needed).
777 * The memory manager does not allow individual objects to be freed; rather,
778 * each created object is assigned to a pool, and whole pools can be freed
779 * at once. This is faster and more convenient than remembering exactly what
780 * to free, especially where malloc()/free() are not too speedy.
781 * NB: alloc routines never return NULL. They exit to error_exit if not
782 * successful.
783 */
784
785#define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
786#define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
787#define JPOOL_NUMPOOLS 2
788
789typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
790typedef struct jvirt_barray_control * jvirt_barray_ptr;
791
792
793struct jpeg_memory_mgr {
794 /* Method pointers */
795 JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
796 size_t sizeofobject));
797 JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
798 size_t sizeofobject));
799 JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
800 JDIMENSION samplesperrow,
801 JDIMENSION numrows));
802 JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
803 JDIMENSION blocksperrow,
804 JDIMENSION numrows));
805 JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
806 int pool_id,
807 boolean pre_zero,
808 JDIMENSION samplesperrow,
809 JDIMENSION numrows,
810 JDIMENSION maxaccess));
811 JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
812 int pool_id,
813 boolean pre_zero,
814 JDIMENSION blocksperrow,
815 JDIMENSION numrows,
816 JDIMENSION maxaccess));
817 JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
818 JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
819 jvirt_sarray_ptr ptr,
820 JDIMENSION start_row,
821 JDIMENSION num_rows,
822 boolean writable));
823 JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
824 jvirt_barray_ptr ptr,
825 JDIMENSION start_row,
826 JDIMENSION num_rows,
827 boolean writable));
828 JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
829 JMETHOD(void, self_destruct, (j_common_ptr cinfo));
830
831 /* Limit on memory allocation for this JPEG object. (Note that this is
832 * merely advisory, not a guaranteed maximum; it only affects the space
833 * used for virtual-array buffers.) May be changed by outer application
834 * after creating the JPEG object.
835 */
836 long max_memory_to_use;
837
838 /* Maximum allocation request accepted by alloc_large. */
839 long max_alloc_chunk;
840};
841
842
843/* Routine signature for application-supplied marker processing methods.
844 * Need not pass marker code since it is stored in cinfo->unread_marker.
845 */
846typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
847
848
849/* Declarations for routines called by application.
850 * The JPP macro hides prototype parameters from compilers that can't cope.
851 * Note JPP requires double parentheses.
852 */
853
854#ifdef HAVE_PROTOTYPES
855#define JPP(arglist) arglist
856#else
857#define JPP(arglist) ()
858#endif
859
860
861/* Short forms of external names for systems with brain-damaged linkers.
862 * We shorten external names to be unique in the first six letters, which
863 * is good enough for all known systems.
864 * (If your compiler itself needs names to be unique in less than 15
865 * characters, you are out of luck. Get a better compiler.)
866 */
867
868#ifdef NEED_SHORT_EXTERNAL_NAMES
869#define jpeg_std_error jStdError
870#define jpeg_CreateCompress jCreaCompress
871#define jpeg_CreateDecompress jCreaDecompress
872#define jpeg_destroy_compress jDestCompress
873#define jpeg_destroy_decompress jDestDecompress
874#define jpeg_stdio_dest jStdDest
875#define jpeg_stdio_src jStdSrc
876#define jpeg_mem_dest jMemDest
877#define jpeg_mem_src jMemSrc
878#define jpeg_set_defaults jSetDefaults
879#define jpeg_set_colorspace jSetColorspace
880#define jpeg_default_colorspace jDefColorspace
881#define jpeg_set_quality jSetQuality
882#define jpeg_set_linear_quality jSetLQuality
883#define jpeg_default_qtables jDefQTables
884#define jpeg_add_quant_table jAddQuantTable
885#define jpeg_quality_scaling jQualityScaling
886#define jpeg_simple_progression jSimProgress
887#define jpeg_suppress_tables jSuppressTables
888#define jpeg_alloc_quant_table jAlcQTable
889#define jpeg_alloc_huff_table jAlcHTable
890#define jpeg_start_compress jStrtCompress
891#define jpeg_write_scanlines jWrtScanlines
892#define jpeg_finish_compress jFinCompress
893#define jpeg_calc_jpeg_dimensions jCjpegDimensions
894#define jpeg_write_raw_data jWrtRawData
895#define jpeg_write_marker jWrtMarker
896#define jpeg_write_m_header jWrtMHeader
897#define jpeg_write_m_byte jWrtMByte
898#define jpeg_write_tables jWrtTables
899#define jpeg_read_header jReadHeader
900#define jpeg_start_decompress jStrtDecompress
901#define jpeg_read_scanlines jReadScanlines
902#define jpeg_finish_decompress jFinDecompress
903#define jpeg_read_raw_data jReadRawData
904#define jpeg_has_multiple_scans jHasMultScn
905#define jpeg_start_output jStrtOutput
906#define jpeg_finish_output jFinOutput
907#define jpeg_input_complete jInComplete
908#define jpeg_new_colormap jNewCMap
909#define jpeg_consume_input jConsumeInput
910#define jpeg_core_output_dimensions jCoreDimensions
911#define jpeg_calc_output_dimensions jCalcDimensions
912#define jpeg_save_markers jSaveMarkers
913#define jpeg_set_marker_processor jSetMarker
914#define jpeg_read_coefficients jReadCoefs
915#define jpeg_write_coefficients jWrtCoefs
916#define jpeg_copy_critical_parameters jCopyCrit
917#define jpeg_abort_compress jAbrtCompress
918#define jpeg_abort_decompress jAbrtDecompress
919#define jpeg_abort jAbort
920#define jpeg_destroy jDestroy
921#define jpeg_resync_to_restart jResyncRestart
922#endif /* NEED_SHORT_EXTERNAL_NAMES */
923
924
925/* Default error-management setup */
926EXTERN(struct jpeg_error_mgr *) jpeg_std_error
927 JPP((struct jpeg_error_mgr * err));
928
929/* Initialization of JPEG compression objects.
930 * jpeg_create_compress() and jpeg_create_decompress() are the exported
931 * names that applications should call. These expand to calls on
932 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
933 * passed for version mismatch checking.
934 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
935 */
936#define jpeg_create_compress(cinfo) \
937 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
938 (size_t) sizeof(struct jpeg_compress_struct))
939#define jpeg_create_decompress(cinfo) \
940 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
941 (size_t) sizeof(struct jpeg_decompress_struct))
942EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo,
943 int version, size_t structsize));
944EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo,
945 int version, size_t structsize));
946/* Destruction of JPEG compression objects */
947EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo));
948EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
949
950/* Standard data source and destination managers: stdio streams. */
951/* Caller is responsible for opening the file before and closing after. */
952EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
953EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile));
954
955/* Data source and destination managers: memory buffers. */
956EXTERN(void) jpeg_mem_dest JPP((j_compress_ptr cinfo,
957 unsigned char ** outbuffer,
958 unsigned long * outsize));
959EXTERN(void) jpeg_mem_src JPP((j_decompress_ptr cinfo,
960 unsigned char * inbuffer,
961 unsigned long insize));
962
963/* Default parameter setup for compression */
964EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo));
965/* Compression parameter setup aids */
966EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo,
967 J_COLOR_SPACE colorspace));
968EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo));
969EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
970 boolean force_baseline));
971EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
972 int scale_factor,
973 boolean force_baseline));
974EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo,
975 boolean force_baseline));
976EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
977 const unsigned int *basic_table,
978 int scale_factor,
979 boolean force_baseline));
980EXTERN(int) jpeg_quality_scaling JPP((int quality));
981EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo));
982EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo,
983 boolean suppress));
984EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo));
985EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo));
986
987/* Main entry points for compression */
988EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo,
989 boolean write_all_tables));
990EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo,
991 JSAMPARRAY scanlines,
992 JDIMENSION num_lines));
993EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo));
994
995/* Precalculate JPEG dimensions for current compression parameters. */
996EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo));
997
998/* Replaces jpeg_write_scanlines when writing raw downsampled data. */
999EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo,
1000 JSAMPIMAGE data,
1001 JDIMENSION num_lines));
1002
1003/* Write a special marker. See libjpeg.txt concerning safe usage. */
1004EXTERN(void) jpeg_write_marker
1005 JPP((j_compress_ptr cinfo, int marker,
1006 const JOCTET * dataptr, unsigned int datalen));
1007/* Same, but piecemeal. */
1008EXTERN(void) jpeg_write_m_header
1009 JPP((j_compress_ptr cinfo, int marker, unsigned int datalen));
1010EXTERN(void) jpeg_write_m_byte
1011 JPP((j_compress_ptr cinfo, int val));
1012
1013/* Alternate compression function: just write an abbreviated table file */
1014EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo));
1015
1016/* Decompression startup: read start of JPEG datastream to see what's there */
1017EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo,
1018 boolean require_image));
1019/* Return value is one of: */
1020#define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
1021#define JPEG_HEADER_OK 1 /* Found valid image datastream */
1022#define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
1023/* If you pass require_image = TRUE (normal case), you need not check for
1024 * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
1025 * JPEG_SUSPENDED is only possible if you use a data source module that can
1026 * give a suspension return (the stdio source module doesn't).
1027 */
1028
1029/* Main entry points for decompression */
1030EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo));
1031EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
1032 JSAMPARRAY scanlines,
1033 JDIMENSION max_lines));
1034EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
1035
1036/* Replaces jpeg_read_scanlines when reading raw downsampled data. */
1037EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
1038 JSAMPIMAGE data,
1039 JDIMENSION max_lines));
1040
1041/* Additional entry points for buffered-image mode. */
1042EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
1043EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo,
1044 int scan_number));
1045EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo));
1046EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo));
1047EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo));
1048EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo));
1049/* Return value is one of: */
1050/* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
1051#define JPEG_REACHED_SOS 1 /* Reached start of new scan */
1052#define JPEG_REACHED_EOI 2 /* Reached end of image */
1053#define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
1054#define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
1055
1056/* Precalculate output dimensions for current decompression parameters. */
1057EXTERN(void) jpeg_core_output_dimensions JPP((j_decompress_ptr cinfo));
1058EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo));
1059
1060/* Control saving of COM and APPn markers into marker_list. */
1061EXTERN(void) jpeg_save_markers
1062 JPP((j_decompress_ptr cinfo, int marker_code,
1063 unsigned int length_limit));
1064
1065/* Install a special processing method for COM or APPn markers. */
1066EXTERN(void) jpeg_set_marker_processor
1067 JPP((j_decompress_ptr cinfo, int marker_code,
1068 jpeg_marker_parser_method routine));
1069
1070/* Read or write raw DCT coefficients --- useful for lossless transcoding. */
1071EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo));
1072EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo,
1073 jvirt_barray_ptr * coef_arrays));
1074EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo,
1075 j_compress_ptr dstinfo));
1076
1077/* If you choose to abort compression or decompression before completing
1078 * jpeg_finish_(de)compress, then you need to clean up to release memory,
1079 * temporary files, etc. You can just call jpeg_destroy_(de)compress
1080 * if you're done with the JPEG object, but if you want to clean it up and
1081 * reuse it, call this:
1082 */
1083EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo));
1084EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo));
1085
1086/* Generic versions of jpeg_abort and jpeg_destroy that work on either
1087 * flavor of JPEG object. These may be more convenient in some places.
1088 */
1089EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo));
1090EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo));
1091
1092/* Default restart-marker-resync procedure for use by data source modules */
1093EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo,
1094 int desired));
1095
1096
1097/* These marker codes are exported since applications and data source modules
1098 * are likely to want to use them.
1099 */
1100
1101#define JPEG_RST0 0xD0 /* RST0 marker code */
1102#define JPEG_EOI 0xD9 /* EOI marker code */
1103#define JPEG_APP0 0xE0 /* APP0 marker code */
1104#define JPEG_COM 0xFE /* COM marker code */
1105
1106
1107/* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1108 * for structure definitions that are never filled in, keep it quiet by
1109 * supplying dummy definitions for the various substructures.
1110 */
1111
1112#ifdef INCOMPLETE_TYPES_BROKEN
1113#ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
1114struct jvirt_sarray_control { long dummy; };
1115struct jvirt_barray_control { long dummy; };
1116struct jpeg_comp_master { long dummy; };
1117struct jpeg_c_main_controller { long dummy; };
1118struct jpeg_c_prep_controller { long dummy; };
1119struct jpeg_c_coef_controller { long dummy; };
1120struct jpeg_marker_writer { long dummy; };
1121struct jpeg_color_converter { long dummy; };
1122struct jpeg_downsampler { long dummy; };
1123struct jpeg_forward_dct { long dummy; };
1124struct jpeg_entropy_encoder { long dummy; };
1125struct jpeg_decomp_master { long dummy; };
1126struct jpeg_d_main_controller { long dummy; };
1127struct jpeg_d_coef_controller { long dummy; };
1128struct jpeg_d_post_controller { long dummy; };
1129struct jpeg_input_controller { long dummy; };
1130struct jpeg_marker_reader { long dummy; };
1131struct jpeg_entropy_decoder { long dummy; };
1132struct jpeg_inverse_dct { long dummy; };
1133struct jpeg_upsampler { long dummy; };
1134struct jpeg_color_deconverter { long dummy; };
1135struct jpeg_color_quantizer { long dummy; };
1136#endif /* JPEG_INTERNALS */
1137#endif /* INCOMPLETE_TYPES_BROKEN */
1138
1139
1140/*
1141 * The JPEG library modules define JPEG_INTERNALS before including this file.
1142 * The internal structure declarations are read only when that is true.
1143 * Applications using the library should not include jpegint.h, but may wish
1144 * to include jerror.h.
1145 */
1146
1147#ifdef JPEG_INTERNALS
1148#include "jpegint.h" /* fetch private declarations */
1149#include "jerror.h" /* fetch error codes too */
1150#endif
1151
1152#ifdef __cplusplus
1153#ifndef DONT_USE_EXTERN_C
1154}
1155#endif
1156#endif
1157
1158#endif /* JPEGLIB_H */
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