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
32 extern "C" {
33 #endif
34 #endif
35
36 /* Version ID for the JPEG library.
37 * Might be useful for tests like "#if JPEG_LIB_VERSION >= 70".
38 */
39
40 #define JPEG_LIB_VERSION 70 /* Version 7.0 */
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
73 typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */
74 typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */
75 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
76
77 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
78 typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */
79 typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
80 typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
81
82 typedef 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
90 typedef 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
107 typedef 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
123 typedef 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_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
191 typedef 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
200 typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr;
201
202 struct 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
213 typedef 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
224 typedef 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
239 typedef 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 */
260 struct 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
268 typedef struct jpeg_common_struct * j_common_ptr;
269 typedef struct jpeg_compress_struct * j_compress_ptr;
270 typedef struct jpeg_decompress_struct * j_decompress_ptr;
271
272
273 /* Master record for a compression instance */
274
275 struct 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 /*
418 * Links to compression subobjects (methods and private variables of modules)
419 */
420 struct jpeg_comp_master * master;
421 struct jpeg_c_main_controller * main;
422 struct jpeg_c_prep_controller * prep;
423 struct jpeg_c_coef_controller * coef;
424 struct jpeg_marker_writer * marker;
425 struct jpeg_color_converter * cconvert;
426 struct jpeg_downsampler * downsample;
427 struct jpeg_forward_dct * fdct;
428 struct jpeg_entropy_encoder * entropy;
429 jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */
430 int script_space_size;
431 };
432
433
434 /* Master record for a decompression instance */
435
436 struct jpeg_decompress_struct {
437 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
438
439 /* Source of compressed data */
440 struct jpeg_source_mgr * src;
441
442 /* Basic description of image --- filled in by jpeg_read_header(). */
443 /* Application may inspect these values to decide how to process image. */
444
445 JDIMENSION image_width; /* nominal image width (from SOF marker) */
446 JDIMENSION image_height; /* nominal image height */
447 int num_components; /* # of color components in JPEG image */
448 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
449
450 /* Decompression processing parameters --- these fields must be set before
451 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
452 * them to default values.
453 */
454
455 J_COLOR_SPACE out_color_space; /* colorspace for output */
456
457 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
458
459 double output_gamma; /* image gamma wanted in output */
460
461 boolean buffered_image; /* TRUE=multiple output passes */
462 boolean raw_data_out; /* TRUE=downsampled data wanted */
463
464 J_DCT_METHOD dct_method; /* IDCT algorithm selector */
465 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
466 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
467
468 boolean quantize_colors; /* TRUE=colormapped output wanted */
469 /* the following are ignored if not quantize_colors: */
470 J_DITHER_MODE dither_mode; /* type of color dithering to use */
471 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
472 int desired_number_of_colors; /* max # colors to use in created colormap */
473 /* these are significant only in buffered-image mode: */
474 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
475 boolean enable_external_quant;/* enable future use of external colormap */
476 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
477
478 /* Description of actual output image that will be returned to application.
479 * These fields are computed by jpeg_start_decompress().
480 * You can also use jpeg_calc_output_dimensions() to determine these values
481 * in advance of calling jpeg_start_decompress().
482 */
483
484 JDIMENSION output_width; /* scaled image width */
485 JDIMENSION output_height; /* scaled image height */
486 int out_color_components; /* # of color components in out_color_space */
487 int output_components; /* # of color components returned */
488 /* output_components is 1 (a colormap index) when quantizing colors;
489 * otherwise it equals out_color_components.
490 */
491 int rec_outbuf_height; /* min recommended height of scanline buffer */
492 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
493 * high, space and time will be wasted due to unnecessary data copying.
494 * Usually rec_outbuf_height will be 1 or 2, at most 4.
495 */
496
497 /* When quantizing colors, the output colormap is described by these fields.
498 * The application can supply a colormap by setting colormap non-NULL before
499 * calling jpeg_start_decompress; otherwise a colormap is created during
500 * jpeg_start_decompress or jpeg_start_output.
501 * The map has out_color_components rows and actual_number_of_colors columns.
502 */
503 int actual_number_of_colors; /* number of entries in use */
504 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */
505
506 /* State variables: these variables indicate the progress of decompression.
507 * The application may examine these but must not modify them.
508 */
509
510 /* Row index of next scanline to be read from jpeg_read_scanlines().
511 * Application may use this to control its processing loop, e.g.,
512 * "while (output_scanline < output_height)".
513 */
514 JDIMENSION output_scanline; /* 0 .. output_height-1 */
515
516 /* Current input scan number and number of iMCU rows completed in scan.
517 * These indicate the progress of the decompressor input side.
518 */
519 int input_scan_number; /* Number of SOS markers seen so far */
520 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
521
522 /* The "output scan number" is the notional scan being displayed by the
523 * output side. The decompressor will not allow output scan/row number
524 * to get ahead of input scan/row, but it can fall arbitrarily far behind.
525 */
526 int output_scan_number; /* Nominal scan number being displayed */
527 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
528
529 /* Current progression status. coef_bits[c][i] indicates the precision
530 * with which component c's DCT coefficient i (in zigzag order) is known.
531 * It is -1 when no data has yet been received, otherwise it is the point
532 * transform (shift) value for the most recent scan of the coefficient
533 * (thus, 0 at completion of the progression).
534 * This pointer is NULL when reading a non-progressive file.
535 */
536 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
537
538 /* Internal JPEG parameters --- the application usually need not look at
539 * these fields. Note that the decompressor output side may not use
540 * any parameters that can change between scans.
541 */
542
543 /* Quantization and Huffman tables are carried forward across input
544 * datastreams when processing abbreviated JPEG datastreams.
545 */
546
547 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
548 /* ptrs to coefficient quantization tables, or NULL if not defined */
549
550 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
551 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
552 /* ptrs to Huffman coding tables, or NULL if not defined */
553
554 /* These parameters are never carried across datastreams, since they
555 * are given in SOF/SOS markers or defined to be reset by SOI.
556 */
557
558 int data_precision; /* bits of precision in image data */
559
560 jpeg_component_info * comp_info;
561 /* comp_info[i] describes component that appears i'th in SOF */
562
563 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
564 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
565
566 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
567 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
568 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
569
570 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
571
572 /* These fields record data obtained from optional markers recognized by
573 * the JPEG library.
574 */
575 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
576 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
577 UINT8 JFIF_major_version; /* JFIF version number */
578 UINT8 JFIF_minor_version;
579 UINT8 density_unit; /* JFIF code for pixel size units */
580 UINT16 X_density; /* Horizontal pixel density */
581 UINT16 Y_density; /* Vertical pixel density */
582 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
583 UINT8 Adobe_transform; /* Color transform code from Adobe marker */
584
585 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
586
587 /* Aside from the specific data retained from APPn markers known to the
588 * library, the uninterpreted contents of any or all APPn and COM markers
589 * can be saved in a list for examination by the application.
590 */
591 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
592
593 /* Remaining fields are known throughout decompressor, but generally
594 * should not be touched by a surrounding application.
595 */
596
597 /*
598 * These fields are computed during decompression startup
599 */
600 int max_h_samp_factor; /* largest h_samp_factor */
601 int max_v_samp_factor; /* largest v_samp_factor */
602
603 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
604 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
605
606 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
607 /* The coefficient controller's input and output progress is measured in
608 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
609 * in fully interleaved JPEG scans, but are used whether the scan is
610 * interleaved or not. We define an iMCU row as v_samp_factor DCT block
611 * rows of each component. Therefore, the IDCT output contains
612 * v_samp_factor*DCT_v_scaled_size sample rows of a component per iMCU row.
613 */
614
615 JSAMPLE * sample_range_limit; /* table for fast range-limiting */
616
617 /*
618 * These fields are valid during any one scan.
619 * They describe the components and MCUs actually appearing in the scan.
620 * Note that the decompressor output side must not use these fields.
621 */
622 int comps_in_scan; /* # of JPEG components in this scan */
623 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
624 /* *cur_comp_info[i] describes component that appears i'th in SOS */
625
626 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
627 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
628
629 int blocks_in_MCU; /* # of DCT blocks per MCU */
630 int MCU_membership[D_MAX_BLOCKS_IN_MCU];
631 /* MCU_membership[i] is index in cur_comp_info of component owning */
632 /* i'th block in an MCU */
633
634 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
635
636 /* This field is shared between entropy decoder and marker parser.
637 * It is either zero or the code of a JPEG marker that has been
638 * read from the data source, but has not yet been processed.
639 */
640 int unread_marker;
641
642 /*
643 * Links to decompression subobjects (methods, private variables of modules)
644 */
645 struct jpeg_decomp_master * master;
646 struct jpeg_d_main_controller * main;
647 struct jpeg_d_coef_controller * coef;
648 struct jpeg_d_post_controller * post;
649 struct jpeg_input_controller * inputctl;
650 struct jpeg_marker_reader * marker;
651 struct jpeg_entropy_decoder * entropy;
652 struct jpeg_inverse_dct * idct;
653 struct jpeg_upsampler * upsample;
654 struct jpeg_color_deconverter * cconvert;
655 struct jpeg_color_quantizer * cquantize;
656 };
657
658
659 /* "Object" declarations for JPEG modules that may be supplied or called
660 * directly by the surrounding application.
661 * As with all objects in the JPEG library, these structs only define the
662 * publicly visible methods and state variables of a module. Additional
663 * private fields may exist after the public ones.
664 */
665
666
667 /* Error handler object */
668
669 struct jpeg_error_mgr {
670 /* Error exit handler: does not return to caller */
671 JMETHOD(void, error_exit, (j_common_ptr cinfo));
672 /* Conditionally emit a trace or warning message */
673 JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
674 /* Routine that actually outputs a trace or error message */
675 JMETHOD(void, output_message, (j_common_ptr cinfo));
676 /* Format a message string for the most recent JPEG error or message */
677 JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
678 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
679 /* Reset error state variables at start of a new image */
680 JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
681
682 /* The message ID code and any parameters are saved here.
683 * A message can have one string parameter or up to 8 int parameters.
684 */
685 int msg_code;
686 #define JMSG_STR_PARM_MAX 80
687 union {
688 int i[8];
689 char s[JMSG_STR_PARM_MAX];
690 } msg_parm;
691
692 /* Standard state variables for error facility */
693
694 int trace_level; /* max msg_level that will be displayed */
695
696 /* For recoverable corrupt-data errors, we emit a warning message,
697 * but keep going unless emit_message chooses to abort. emit_message
698 * should count warnings in num_warnings. The surrounding application
699 * can check for bad data by seeing if num_warnings is nonzero at the
700 * end of processing.
701 */
702 long num_warnings; /* number of corrupt-data warnings */
703
704 /* These fields point to the table(s) of error message strings.
705 * An application can change the table pointer to switch to a different
706 * message list (typically, to change the language in which errors are
707 * reported). Some applications may wish to add additional error codes
708 * that will be handled by the JPEG library error mechanism; the second
709 * table pointer is used for this purpose.
710 *
711 * First table includes all errors generated by JPEG library itself.
712 * Error code 0 is reserved for a "no such error string" message.
713 */
714 const char * const * jpeg_message_table; /* Library errors */
715 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
716 /* Second table can be added by application (see cjpeg/djpeg for example).
717 * It contains strings numbered first_addon_message..last_addon_message.
718 */
719 const char * const * addon_message_table; /* Non-library errors */
720 int first_addon_message; /* code for first string in addon table */
721 int last_addon_message; /* code for last string in addon table */
722 };
723
724
725 /* Progress monitor object */
726
727 struct jpeg_progress_mgr {
728 JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
729
730 long pass_counter; /* work units completed in this pass */
731 long pass_limit; /* total number of work units in this pass */
732 int completed_passes; /* passes completed so far */
733 int total_passes; /* total number of passes expected */
734 };
735
736
737 /* Data destination object for compression */
738
739 struct jpeg_destination_mgr {
740 JOCTET * next_output_byte; /* => next byte to write in buffer */
741 size_t free_in_buffer; /* # of byte spaces remaining in buffer */
742
743 JMETHOD(void, init_destination, (j_compress_ptr cinfo));
744 JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
745 JMETHOD(void, term_destination, (j_compress_ptr cinfo));
746 };
747
748
749 /* Data source object for decompression */
750
751 struct jpeg_source_mgr {
752 const JOCTET * next_input_byte; /* => next byte to read from buffer */
753 size_t bytes_in_buffer; /* # of bytes remaining in buffer */
754
755 JMETHOD(void, init_source, (j_decompress_ptr cinfo));
756 JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
757 JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
758 JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
759 JMETHOD(void, term_source, (j_decompress_ptr cinfo));
760 };
761
762
763 /* Memory manager object.
764 * Allocates "small" objects (a few K total), "large" objects (tens of K),
765 * and "really big" objects (virtual arrays with backing store if needed).
766 * The memory manager does not allow individual objects to be freed; rather,
767 * each created object is assigned to a pool, and whole pools can be freed
768 * at once. This is faster and more convenient than remembering exactly what
769 * to free, especially where malloc()/free() are not too speedy.
770 * NB: alloc routines never return NULL. They exit to error_exit if not
771 * successful.
772 */
773
774 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
775 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
776 #define JPOOL_NUMPOOLS 2
777
778 typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
779 typedef struct jvirt_barray_control * jvirt_barray_ptr;
780
781
782 struct jpeg_memory_mgr {
783 /* Method pointers */
784 JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
785 size_t sizeofobject));
786 JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
787 size_t sizeofobject));
788 JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
789 JDIMENSION samplesperrow,
790 JDIMENSION numrows));
791 JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
792 JDIMENSION blocksperrow,
793 JDIMENSION numrows));
794 JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
795 int pool_id,
796 boolean pre_zero,
797 JDIMENSION samplesperrow,
798 JDIMENSION numrows,
799 JDIMENSION maxaccess));
800 JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
801 int pool_id,
802 boolean pre_zero,
803 JDIMENSION blocksperrow,
804 JDIMENSION numrows,
805 JDIMENSION maxaccess));
806 JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
807 JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
808 jvirt_sarray_ptr ptr,
809 JDIMENSION start_row,
810 JDIMENSION num_rows,
811 boolean writable));
812 JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
813 jvirt_barray_ptr ptr,
814 JDIMENSION start_row,
815 JDIMENSION num_rows,
816 boolean writable));
817 JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
818 JMETHOD(void, self_destruct, (j_common_ptr cinfo));
819
820 /* Limit on memory allocation for this JPEG object. (Note that this is
821 * merely advisory, not a guaranteed maximum; it only affects the space
822 * used for virtual-array buffers.) May be changed by outer application
823 * after creating the JPEG object.
824 */
825 long max_memory_to_use;
826
827 /* Maximum allocation request accepted by alloc_large. */
828 long max_alloc_chunk;
829 };
830
831
832 /* Routine signature for application-supplied marker processing methods.
833 * Need not pass marker code since it is stored in cinfo->unread_marker.
834 */
835 typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
836
837
838 /* Declarations for routines called by application.
839 * The JPP macro hides prototype parameters from compilers that can't cope.
840 * Note JPP requires double parentheses.
841 */
842
843 #ifdef HAVE_PROTOTYPES
844 #define JPP(arglist) arglist
845 #else
846 #define JPP(arglist) ()
847 #endif
848
849
850 /* Short forms of external names for systems with brain-damaged linkers.
851 * We shorten external names to be unique in the first six letters, which
852 * is good enough for all known systems.
853 * (If your compiler itself needs names to be unique in less than 15
854 * characters, you are out of luck. Get a better compiler.)
855 */
856
857 #ifdef NEED_SHORT_EXTERNAL_NAMES
858 #define jpeg_std_error jStdError
859 #define jpeg_CreateCompress jCreaCompress
860 #define jpeg_CreateDecompress jCreaDecompress
861 #define jpeg_destroy_compress jDestCompress
862 #define jpeg_destroy_decompress jDestDecompress
863 #define jpeg_stdio_dest jStdDest
864 #define jpeg_stdio_src jStdSrc
865 #define jpeg_set_defaults jSetDefaults
866 #define jpeg_set_colorspace jSetColorspace
867 #define jpeg_default_colorspace jDefColorspace
868 #define jpeg_set_quality jSetQuality
869 #define jpeg_set_linear_quality jSetLQuality
870 #define jpeg_default_qtables jDefQTables
871 #define jpeg_add_quant_table jAddQuantTable
872 #define jpeg_quality_scaling jQualityScaling
873 #define jpeg_simple_progression jSimProgress
874 #define jpeg_suppress_tables jSuppressTables
875 #define jpeg_alloc_quant_table jAlcQTable
876 #define jpeg_alloc_huff_table jAlcHTable
877 #define jpeg_start_compress jStrtCompress
878 #define jpeg_write_scanlines jWrtScanlines
879 #define jpeg_finish_compress jFinCompress
880 #define jpeg_calc_jpeg_dimensions jCjpegDimensions
881 #define jpeg_write_raw_data jWrtRawData
882 #define jpeg_write_marker jWrtMarker
883 #define jpeg_write_m_header jWrtMHeader
884 #define jpeg_write_m_byte jWrtMByte
885 #define jpeg_write_tables jWrtTables
886 #define jpeg_read_header jReadHeader
887 #define jpeg_start_decompress jStrtDecompress
888 #define jpeg_read_scanlines jReadScanlines
889 #define jpeg_finish_decompress jFinDecompress
890 #define jpeg_read_raw_data jReadRawData
891 #define jpeg_has_multiple_scans jHasMultScn
892 #define jpeg_start_output jStrtOutput
893 #define jpeg_finish_output jFinOutput
894 #define jpeg_input_complete jInComplete
895 #define jpeg_new_colormap jNewCMap
896 #define jpeg_consume_input jConsumeInput
897 #define jpeg_calc_output_dimensions jCalcDimensions
898 #define jpeg_save_markers jSaveMarkers
899 #define jpeg_set_marker_processor jSetMarker
900 #define jpeg_read_coefficients jReadCoefs
901 #define jpeg_write_coefficients jWrtCoefs
902 #define jpeg_copy_critical_parameters jCopyCrit
903 #define jpeg_abort_compress jAbrtCompress
904 #define jpeg_abort_decompress jAbrtDecompress
905 #define jpeg_abort jAbort
906 #define jpeg_destroy jDestroy
907 #define jpeg_resync_to_restart jResyncRestart
908 #endif /* NEED_SHORT_EXTERNAL_NAMES */
909
910
911 /* Default error-management setup */
912 EXTERN(struct jpeg_error_mgr *) jpeg_std_error
913 JPP((struct jpeg_error_mgr * err));
914
915 /* Initialization of JPEG compression objects.
916 * jpeg_create_compress() and jpeg_create_decompress() are the exported
917 * names that applications should call. These expand to calls on
918 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
919 * passed for version mismatch checking.
920 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
921 */
922 #define jpeg_create_compress(cinfo) \
923 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
924 (size_t) sizeof(struct jpeg_compress_struct))
925 #define jpeg_create_decompress(cinfo) \
926 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
927 (size_t) sizeof(struct jpeg_decompress_struct))
928 EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo,
929 int version, size_t structsize));
930 EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo,
931 int version, size_t structsize));
932 /* Destruction of JPEG compression objects */
933 EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo));
934 EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
935
936 /* Standard data source and destination managers: stdio streams. */
937 /* Caller is responsible for opening the file before and closing after. */
938 EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
939 EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile));
940
941 /* Default parameter setup for compression */
942 EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo));
943 /* Compression parameter setup aids */
944 EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo,
945 J_COLOR_SPACE colorspace));
946 EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo));
947 EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
948 boolean force_baseline));
949 EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
950 int scale_factor,
951 boolean force_baseline));
952 EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo,
953 boolean force_baseline));
954 EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
955 const unsigned int *basic_table,
956 int scale_factor,
957 boolean force_baseline));
958 EXTERN(int) jpeg_quality_scaling JPP((int quality));
959 EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo));
960 EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo,
961 boolean suppress));
962 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo));
963 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo));
964
965 /* Main entry points for compression */
966 EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo,
967 boolean write_all_tables));
968 EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo,
969 JSAMPARRAY scanlines,
970 JDIMENSION num_lines));
971 EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo));
972
973 /* Precalculate JPEG dimensions for current compression parameters. */
974 EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo));
975
976 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
977 EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo,
978 JSAMPIMAGE data,
979 JDIMENSION num_lines));
980
981 /* Write a special marker. See libjpeg.txt concerning safe usage. */
982 EXTERN(void) jpeg_write_marker
983 JPP((j_compress_ptr cinfo, int marker,
984 const JOCTET * dataptr, unsigned int datalen));
985 /* Same, but piecemeal. */
986 EXTERN(void) jpeg_write_m_header
987 JPP((j_compress_ptr cinfo, int marker, unsigned int datalen));
988 EXTERN(void) jpeg_write_m_byte
989 JPP((j_compress_ptr cinfo, int val));
990
991 /* Alternate compression function: just write an abbreviated table file */
992 EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo));
993
994 /* Decompression startup: read start of JPEG datastream to see what's there */
995 EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo,
996 boolean require_image));
997 /* Return value is one of: */
998 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
999 #define JPEG_HEADER_OK 1 /* Found valid image datastream */
1000 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
1001 /* If you pass require_image = TRUE (normal case), you need not check for
1002 * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
1003 * JPEG_SUSPENDED is only possible if you use a data source module that can
1004 * give a suspension return (the stdio source module doesn't).
1005 */
1006
1007 /* Main entry points for decompression */
1008 EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo));
1009 EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
1010 JSAMPARRAY scanlines,
1011 JDIMENSION max_lines));
1012 EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
1013
1014 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
1015 EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
1016 JSAMPIMAGE data,
1017 JDIMENSION max_lines));
1018
1019 /* Additional entry points for buffered-image mode. */
1020 EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
1021 EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo,
1022 int scan_number));
1023 EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo));
1024 EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo));
1025 EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo));
1026 EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo));
1027 /* Return value is one of: */
1028 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
1029 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */
1030 #define JPEG_REACHED_EOI 2 /* Reached end of image */
1031 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
1032 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
1033
1034 /* Precalculate output dimensions for current decompression parameters. */
1035 EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo));
1036
1037 /* Control saving of COM and APPn markers into marker_list. */
1038 EXTERN(void) jpeg_save_markers
1039 JPP((j_decompress_ptr cinfo, int marker_code,
1040 unsigned int length_limit));
1041
1042 /* Install a special processing method for COM or APPn markers. */
1043 EXTERN(void) jpeg_set_marker_processor
1044 JPP((j_decompress_ptr cinfo, int marker_code,
1045 jpeg_marker_parser_method routine));
1046
1047 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
1048 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo));
1049 EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo,
1050 jvirt_barray_ptr * coef_arrays));
1051 EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo,
1052 j_compress_ptr dstinfo));
1053
1054 /* If you choose to abort compression or decompression before completing
1055 * jpeg_finish_(de)compress, then you need to clean up to release memory,
1056 * temporary files, etc. You can just call jpeg_destroy_(de)compress
1057 * if you're done with the JPEG object, but if you want to clean it up and
1058 * reuse it, call this:
1059 */
1060 EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo));
1061 EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo));
1062
1063 /* Generic versions of jpeg_abort and jpeg_destroy that work on either
1064 * flavor of JPEG object. These may be more convenient in some places.
1065 */
1066 EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo));
1067 EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo));
1068
1069 /* Default restart-marker-resync procedure for use by data source modules */
1070 EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo,
1071 int desired));
1072
1073
1074 /* These marker codes are exported since applications and data source modules
1075 * are likely to want to use them.
1076 */
1077
1078 #define JPEG_RST0 0xD0 /* RST0 marker code */
1079 #define JPEG_EOI 0xD9 /* EOI marker code */
1080 #define JPEG_APP0 0xE0 /* APP0 marker code */
1081 #define JPEG_COM 0xFE /* COM marker code */
1082
1083
1084 /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1085 * for structure definitions that are never filled in, keep it quiet by
1086 * supplying dummy definitions for the various substructures.
1087 */
1088
1089 #ifdef INCOMPLETE_TYPES_BROKEN
1090 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
1091 struct jvirt_sarray_control { long dummy; };
1092 struct jvirt_barray_control { long dummy; };
1093 struct jpeg_comp_master { long dummy; };
1094 struct jpeg_c_main_controller { long dummy; };
1095 struct jpeg_c_prep_controller { long dummy; };
1096 struct jpeg_c_coef_controller { long dummy; };
1097 struct jpeg_marker_writer { long dummy; };
1098 struct jpeg_color_converter { long dummy; };
1099 struct jpeg_downsampler { long dummy; };
1100 struct jpeg_forward_dct { long dummy; };
1101 struct jpeg_entropy_encoder { long dummy; };
1102 struct jpeg_decomp_master { long dummy; };
1103 struct jpeg_d_main_controller { long dummy; };
1104 struct jpeg_d_coef_controller { long dummy; };
1105 struct jpeg_d_post_controller { long dummy; };
1106 struct jpeg_input_controller { long dummy; };
1107 struct jpeg_marker_reader { long dummy; };
1108 struct jpeg_entropy_decoder { long dummy; };
1109 struct jpeg_inverse_dct { long dummy; };
1110 struct jpeg_upsampler { long dummy; };
1111 struct jpeg_color_deconverter { long dummy; };
1112 struct jpeg_color_quantizer { long dummy; };
1113 #endif /* JPEG_INTERNALS */
1114 #endif /* INCOMPLETE_TYPES_BROKEN */
1115
1116
1117 /*
1118 * The JPEG library modules define JPEG_INTERNALS before including this file.
1119 * The internal structure declarations are read only when that is true.
1120 * Applications using the library should not include jpegint.h, but may wish
1121 * to include jerror.h.
1122 */
1123
1124 #ifdef JPEG_INTERNALS
1125 #include "jpegint.h" /* fetch private declarations */
1126 #include "jerror.h" /* fetch error codes too */
1127 #endif
1128
1129 #ifdef __cplusplus
1130 #ifndef DONT_USE_EXTERN_C
1131 }
1132 #endif
1133 #endif
1134
1135 #endif /* JPEGLIB_H */