-
Notifications
You must be signed in to change notification settings - Fork 1
/
jpeglib.h
1183 lines (980 loc) · 48.3 KB
/
jpeglib.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* jpeglib.h
*
* Copyright (C) 1991-1998, Thomas G. Lane.
* Modified 2002-2019 by Guido Vollbeding.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file defines the application interface for the JPEG library.
* Most applications using the library need only include this file,
* and perhaps jerror.h if they want to know the exact error codes.
*/
#ifndef JPEGLIB_H
#define JPEGLIB_H
/*
* First we include the configuration files that record how this
* installation of the JPEG library is set up. jconfig.h can be
* generated automatically for many systems. jmorecfg.h contains
* manual configuration options that most people need not worry about.
*/
#ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */
#include "jconfig.h" /* widely used configuration options */
#endif
#include "jmorecfg.h" /* seldom changed options */
#ifdef __cplusplus
#ifndef DONT_USE_EXTERN_C
extern "C" {
#endif
#endif
/* Version IDs for the JPEG library.
* Might be useful for tests like "#if JPEG_LIB_VERSION >= 90".
*/
#define JPEG_LIB_VERSION 90 /* Compatibility version 9.0 */
#define JPEG_LIB_VERSION_MAJOR 9
#define JPEG_LIB_VERSION_MINOR 4
/* Various constants determining the sizes of things.
* All of these are specified by the JPEG standard,
* so don't change them if you want to be compatible.
*/
#define DCTSIZE 8 /* The basic DCT block is 8x8 coefficients */
#define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
#define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
#define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
#define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
#define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
#define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
/* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
* the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
* If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
* to handle it. We even let you do this from the jconfig.h file. However,
* we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
* sometimes emits noncompliant files doesn't mean you should too.
*/
#define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */
#ifndef D_MAX_BLOCKS_IN_MCU
#define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */
#endif
/* Data structures for images (arrays of samples and of DCT coefficients).
* On 80x86 machines, the image arrays are too big for near pointers,
* but the pointer arrays can fit in near memory.
*/
typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */
typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */
typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */
typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */
/* Types for JPEG compression parameters and working tables. */
/* DCT coefficient quantization tables. */
typedef struct {
/* This array gives the coefficient quantizers in natural array order
* (not the zigzag order in which they are stored in a JPEG DQT marker).
* CAUTION: IJG versions prior to v6a kept this array in zigzag order.
*/
UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */
/* This field is used only during compression. It's initialized FALSE when
* the table is created, and set TRUE when it's been output to the file.
* You could suppress output of a table by setting this to TRUE.
* (See jpeg_suppress_tables for an example.)
*/
boolean sent_table; /* TRUE when table has been output */
} JQUANT_TBL;
/* Huffman coding tables. */
typedef struct {
/* These two fields directly represent the contents of a JPEG DHT marker */
UINT8 bits[17]; /* bits[k] = # of symbols with codes of */
/* length k bits; bits[0] is unused */
UINT8 huffval[256]; /* The symbols, in order of incr code length */
/* This field is used only during compression. It's initialized FALSE when
* the table is created, and set TRUE when it's been output to the file.
* You could suppress output of a table by setting this to TRUE.
* (See jpeg_suppress_tables for an example.)
*/
boolean sent_table; /* TRUE when table has been output */
} JHUFF_TBL;
/* Basic info about one component (color channel). */
typedef struct {
/* These values are fixed over the whole image. */
/* For compression, they must be supplied by parameter setup; */
/* for decompression, they are read from the SOF marker. */
int component_id; /* identifier for this component (0..255) */
int component_index; /* its index in SOF or cinfo->comp_info[] */
int h_samp_factor; /* horizontal sampling factor (1..4) */
int v_samp_factor; /* vertical sampling factor (1..4) */
int quant_tbl_no; /* quantization table selector (0..3) */
/* These values may vary between scans. */
/* For compression, they must be supplied by parameter setup; */
/* for decompression, they are read from the SOS marker. */
/* The decompressor output side may not use these variables. */
int dc_tbl_no; /* DC entropy table selector (0..3) */
int ac_tbl_no; /* AC entropy table selector (0..3) */
/* Remaining fields should be treated as private by applications. */
/* These values are computed during compression or decompression startup: */
/* Component's size in DCT blocks.
* Any dummy blocks added to complete an MCU are not counted; therefore
* these values do not depend on whether a scan is interleaved or not.
*/
JDIMENSION width_in_blocks;
JDIMENSION height_in_blocks;
/* Size of a DCT block in samples,
* reflecting any scaling we choose to apply during the DCT step.
* Values from 1 to 16 are supported.
* Note that different components may receive different DCT scalings.
*/
int DCT_h_scaled_size;
int DCT_v_scaled_size;
/* The downsampled dimensions are the component's actual, unpadded number
* of samples at the main buffer (preprocessing/compression interface);
* DCT scaling is included, so
* downsampled_width =
* ceil(image_width * Hi/Hmax * DCT_h_scaled_size/block_size)
* and similarly for height.
*/
JDIMENSION downsampled_width; /* actual width in samples */
JDIMENSION downsampled_height; /* actual height in samples */
/* For decompression, in cases where some of the components will be
* ignored (eg grayscale output from YCbCr image), we can skip most
* computations for the unused components.
* For compression, some of the components will need further quantization
* scale by factor of 2 after DCT (eg BG_YCC output from normal RGB input).
* The field is first set TRUE for decompression, FALSE for compression
* in initial_setup, and then adapted in color conversion setup.
*/
boolean component_needed;
/* These values are computed before starting a scan of the component. */
/* The decompressor output side may not use these variables. */
int MCU_width; /* number of blocks per MCU, horizontally */
int MCU_height; /* number of blocks per MCU, vertically */
int MCU_blocks; /* MCU_width * MCU_height */
int MCU_sample_width; /* MCU width in samples: MCU_width * DCT_h_scaled_size */
int last_col_width; /* # of non-dummy blocks across in last MCU */
int last_row_height; /* # of non-dummy blocks down in last MCU */
/* Saved quantization table for component; NULL if none yet saved.
* See jdinput.c comments about the need for this information.
* This field is currently used only for decompression.
*/
JQUANT_TBL * quant_table;
/* Private per-component storage for DCT or IDCT subsystem. */
void * dct_table;
} jpeg_component_info;
/* The script for encoding a multiple-scan file is an array of these: */
typedef struct {
int comps_in_scan; /* number of components encoded in this scan */
int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
int Ss, Se; /* progressive JPEG spectral selection parms */
int Ah, Al; /* progressive JPEG successive approx. parms */
} jpeg_scan_info;
/* The decompressor can save APPn and COM markers in a list of these: */
typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr;
struct jpeg_marker_struct {
jpeg_saved_marker_ptr next; /* next in list, or NULL */
UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */
unsigned int original_length; /* # bytes of data in the file */
unsigned int data_length; /* # bytes of data saved at data[] */
JOCTET FAR * data; /* the data contained in the marker */
/* the marker length word is not counted in data_length or original_length */
};
/* Known color spaces. */
typedef enum {
JCS_UNKNOWN, /* error/unspecified */
JCS_GRAYSCALE, /* monochrome */
JCS_RGB, /* red/green/blue, standard RGB (sRGB) */
JCS_YCbCr, /* Y/Cb/Cr (also known as YUV), standard YCC */
JCS_CMYK, /* C/M/Y/K */
JCS_YCCK, /* Y/Cb/Cr/K */
JCS_BG_RGB, /* big gamut red/green/blue, bg-sRGB */
JCS_BG_YCC /* big gamut Y/Cb/Cr, bg-sYCC */
} J_COLOR_SPACE;
/* Supported color transforms. */
typedef enum {
JCT_NONE = 0,
JCT_SUBTRACT_GREEN = 1
} J_COLOR_TRANSFORM;
/* DCT/IDCT algorithm options. */
typedef enum {
JDCT_ISLOW, /* slow but accurate integer algorithm */
JDCT_IFAST, /* faster, less accurate integer method */
JDCT_FLOAT /* floating-point: accurate, fast on fast HW */
} J_DCT_METHOD;
#ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
#define JDCT_DEFAULT JDCT_ISLOW
#endif
#ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
#define JDCT_FASTEST JDCT_IFAST
#endif
/* Dithering options for decompression. */
typedef enum {
JDITHER_NONE, /* no dithering */
JDITHER_ORDERED, /* simple ordered dither */
JDITHER_FS /* Floyd-Steinberg error diffusion dither */
} J_DITHER_MODE;
/* Common fields between JPEG compression and decompression master structs. */
#define jpeg_common_fields \
struct jpeg_error_mgr * err; /* Error handler module */\
struct jpeg_memory_mgr * mem; /* Memory manager module */\
struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
void * client_data; /* Available for use by application */\
boolean is_decompressor; /* So common code can tell which is which */\
int global_state /* For checking call sequence validity */
/* Routines that are to be used by both halves of the library are declared
* to receive a pointer to this structure. There are no actual instances of
* jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
*/
struct jpeg_common_struct {
jpeg_common_fields; /* Fields common to both master struct types */
/* Additional fields follow in an actual jpeg_compress_struct or
* jpeg_decompress_struct. All three structs must agree on these
* initial fields! (This would be a lot cleaner in C++.)
*/
};
typedef struct jpeg_common_struct * j_common_ptr;
typedef struct jpeg_compress_struct * j_compress_ptr;
typedef struct jpeg_decompress_struct * j_decompress_ptr;
/* Master record for a compression instance */
struct jpeg_compress_struct {
jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */
/* Destination for compressed data */
struct jpeg_destination_mgr * dest;
/* Description of source image --- these fields must be filled in by
* outer application before starting compression. in_color_space must
* be correct before you can even call jpeg_set_defaults().
*/
JDIMENSION image_width; /* input image width */
JDIMENSION image_height; /* input image height */
int input_components; /* # of color components in input image */
J_COLOR_SPACE in_color_space; /* colorspace of input image */
double input_gamma; /* image gamma of input image */
/* Compression parameters --- these fields must be set before calling
* jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
* initialize everything to reasonable defaults, then changing anything
* the application specifically wants to change. That way you won't get
* burnt when new parameters are added. Also note that there are several
* helper routines to simplify changing parameters.
*/
unsigned int scale_num, scale_denom; /* fraction by which to scale image */
JDIMENSION jpeg_width; /* scaled JPEG image width */
JDIMENSION jpeg_height; /* scaled JPEG image height */
/* Dimensions of actual JPEG image that will be written to file,
* derived from input dimensions by scaling factors above.
* These fields are computed by jpeg_start_compress().
* You can also use jpeg_calc_jpeg_dimensions() to determine these values
* in advance of calling jpeg_start_compress().
*/
int data_precision; /* bits of precision in image data */
int num_components; /* # of color components in JPEG image */
J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
jpeg_component_info * comp_info;
/* comp_info[i] describes component that appears i'th in SOF */
JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
int q_scale_factor[NUM_QUANT_TBLS];
/* ptrs to coefficient quantization tables, or NULL if not defined,
* and corresponding scale factors (percentage, initialized 100).
*/
JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
/* ptrs to Huffman coding tables, or NULL if not defined */
UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
int num_scans; /* # of entries in scan_info array */
const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */
/* The default value of scan_info is NULL, which causes a single-scan
* sequential JPEG file to be emitted. To create a multi-scan file,
* set num_scans and scan_info to point to an array of scan definitions.
*/
boolean raw_data_in; /* TRUE=caller supplies downsampled data */
boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
boolean optimize_coding; /* TRUE=optimize entropy encoding parms */
boolean CCIR601_sampling; /* TRUE=first samples are cosited */
boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
int smoothing_factor; /* 1..100, or 0 for no input smoothing */
J_DCT_METHOD dct_method; /* DCT algorithm selector */
/* The restart interval can be specified in absolute MCUs by setting
* restart_interval, or in MCU rows by setting restart_in_rows
* (in which case the correct restart_interval will be figured
* for each scan).
*/
unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
int restart_in_rows; /* if > 0, MCU rows per restart interval */
/* Parameters controlling emission of special markers. */
boolean write_JFIF_header; /* should a JFIF marker be written? */
UINT8 JFIF_major_version; /* What to write for the JFIF version number */
UINT8 JFIF_minor_version;
/* These three values are not used by the JPEG code, merely copied */
/* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
/* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
/* ratio is defined by X_density/Y_density even when density_unit=0. */
UINT8 density_unit; /* JFIF code for pixel size units */
UINT16 X_density; /* Horizontal pixel density */
UINT16 Y_density; /* Vertical pixel density */
boolean write_Adobe_marker; /* should an Adobe marker be written? */
J_COLOR_TRANSFORM color_transform;
/* Color transform identifier, writes LSE marker if nonzero */
/* State variable: index of next scanline to be written to
* jpeg_write_scanlines(). Application may use this to control its
* processing loop, e.g., "while (next_scanline < image_height)".
*/
JDIMENSION next_scanline; /* 0 .. image_height-1 */
/* Remaining fields are known throughout compressor, but generally
* should not be touched by a surrounding application.
*/
/*
* These fields are computed during compression startup
*/
boolean progressive_mode; /* TRUE if scan script uses progressive mode */
int max_h_samp_factor; /* largest h_samp_factor */
int max_v_samp_factor; /* largest v_samp_factor */
int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */
/* The coefficient controller receives data in units of MCU rows as defined
* for fully interleaved scans (whether the JPEG file is interleaved or not).
* There are v_samp_factor * DCT_v_scaled_size sample rows of each component
* in an "iMCU" (interleaved MCU) row.
*/
/*
* These fields are valid during any one scan.
* They describe the components and MCUs actually appearing in the scan.
*/
int comps_in_scan; /* # of JPEG components in this scan */
jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
/* *cur_comp_info[i] describes component that appears i'th in SOS */
JDIMENSION MCUs_per_row; /* # of MCUs across the image */
JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
int blocks_in_MCU; /* # of DCT blocks per MCU */
int MCU_membership[C_MAX_BLOCKS_IN_MCU];
/* MCU_membership[i] is index in cur_comp_info of component owning */
/* i'th block in an MCU */
int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
int block_size; /* the basic DCT block size: 1..16 */
const int * natural_order; /* natural-order position array */
int lim_Se; /* min( Se, DCTSIZE2-1 ) */
/*
* Links to compression subobjects (methods and private variables of modules)
*/
struct jpeg_comp_master * master;
struct jpeg_c_main_controller * main;
struct jpeg_c_prep_controller * prep;
struct jpeg_c_coef_controller * coef;
struct jpeg_marker_writer * marker;
struct jpeg_color_converter * cconvert;
struct jpeg_downsampler * downsample;
struct jpeg_forward_dct * fdct;
struct jpeg_entropy_encoder * entropy;
jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */
int script_space_size;
};
/* Master record for a decompression instance */
struct jpeg_decompress_struct {
jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
/* Source of compressed data */
struct jpeg_source_mgr * src;
/* Basic description of image --- filled in by jpeg_read_header(). */
/* Application may inspect these values to decide how to process image. */
JDIMENSION image_width; /* nominal image width (from SOF marker) */
JDIMENSION image_height; /* nominal image height */
int num_components; /* # of color components in JPEG image */
J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
/* Decompression processing parameters --- these fields must be set before
* calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
* them to default values.
*/
J_COLOR_SPACE out_color_space; /* colorspace for output */
unsigned int scale_num, scale_denom; /* fraction by which to scale image */
double output_gamma; /* image gamma wanted in output */
boolean buffered_image; /* TRUE=multiple output passes */
boolean raw_data_out; /* TRUE=downsampled data wanted */
J_DCT_METHOD dct_method; /* IDCT algorithm selector */
boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
boolean quantize_colors; /* TRUE=colormapped output wanted */
/* the following are ignored if not quantize_colors: */
J_DITHER_MODE dither_mode; /* type of color dithering to use */
boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
int desired_number_of_colors; /* max # colors to use in created colormap */
/* these are significant only in buffered-image mode: */
boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
boolean enable_external_quant;/* enable future use of external colormap */
boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
/* Description of actual output image that will be returned to application.
* These fields are computed by jpeg_start_decompress().
* You can also use jpeg_calc_output_dimensions() to determine these values
* in advance of calling jpeg_start_decompress().
*/
JDIMENSION output_width; /* scaled image width */
JDIMENSION output_height; /* scaled image height */
int out_color_components; /* # of color components in out_color_space */
int output_components; /* # of color components returned */
/* output_components is 1 (a colormap index) when quantizing colors;
* otherwise it equals out_color_components.
*/
int rec_outbuf_height; /* min recommended height of scanline buffer */
/* If the buffer passed to jpeg_read_scanlines() is less than this many rows
* high, space and time will be wasted due to unnecessary data copying.
* Usually rec_outbuf_height will be 1 or 2, at most 4.
*/
/* When quantizing colors, the output colormap is described by these fields.
* The application can supply a colormap by setting colormap non-NULL before
* calling jpeg_start_decompress; otherwise a colormap is created during
* jpeg_start_decompress or jpeg_start_output.
* The map has out_color_components rows and actual_number_of_colors columns.
*/
int actual_number_of_colors; /* number of entries in use */
JSAMPARRAY colormap; /* The color map as a 2-D pixel array */
/* State variables: these variables indicate the progress of decompression.
* The application may examine these but must not modify them.
*/
/* Row index of next scanline to be read from jpeg_read_scanlines().
* Application may use this to control its processing loop, e.g.,
* "while (output_scanline < output_height)".
*/
JDIMENSION output_scanline; /* 0 .. output_height-1 */
/* Current input scan number and number of iMCU rows completed in scan.
* These indicate the progress of the decompressor input side.
*/
int input_scan_number; /* Number of SOS markers seen so far */
JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
/* The "output scan number" is the notional scan being displayed by the
* output side. The decompressor will not allow output scan/row number
* to get ahead of input scan/row, but it can fall arbitrarily far behind.
*/
int output_scan_number; /* Nominal scan number being displayed */
JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
/* Current progression status. coef_bits[c][i] indicates the precision
* with which component c's DCT coefficient i (in zigzag order) is known.
* It is -1 when no data has yet been received, otherwise it is the point
* transform (shift) value for the most recent scan of the coefficient
* (thus, 0 at completion of the progression).
* This pointer is NULL when reading a non-progressive file.
*/
int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
/* Internal JPEG parameters --- the application usually need not look at
* these fields. Note that the decompressor output side may not use
* any parameters that can change between scans.
*/
/* Quantization and Huffman tables are carried forward across input
* datastreams when processing abbreviated JPEG datastreams.
*/
JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
/* ptrs to coefficient quantization tables, or NULL if not defined */
JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
/* ptrs to Huffman coding tables, or NULL if not defined */
/* These parameters are never carried across datastreams, since they
* are given in SOF/SOS markers or defined to be reset by SOI.
*/
int data_precision; /* bits of precision in image data */
jpeg_component_info * comp_info;
/* comp_info[i] describes component that appears i'th in SOF */
boolean is_baseline; /* TRUE if Baseline SOF0 encountered */
boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
/* These fields record data obtained from optional markers recognized by
* the JPEG library.
*/
boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
/* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
UINT8 JFIF_major_version; /* JFIF version number */
UINT8 JFIF_minor_version;
UINT8 density_unit; /* JFIF code for pixel size units */
UINT16 X_density; /* Horizontal pixel density */
UINT16 Y_density; /* Vertical pixel density */
boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
UINT8 Adobe_transform; /* Color transform code from Adobe marker */
J_COLOR_TRANSFORM color_transform;
/* Color transform identifier derived from LSE marker, otherwise zero */
boolean CCIR601_sampling; /* TRUE=first samples are cosited */
/* Aside from the specific data retained from APPn markers known to the
* library, the uninterpreted contents of any or all APPn and COM markers
* can be saved in a list for examination by the application.
*/
jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
/* Remaining fields are known throughout decompressor, but generally
* should not be touched by a surrounding application.
*/
/*
* These fields are computed during decompression startup
*/
int max_h_samp_factor; /* largest h_samp_factor */
int max_v_samp_factor; /* largest v_samp_factor */
int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
/* The coefficient controller's input and output progress is measured in
* units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
* in fully interleaved JPEG scans, but are used whether the scan is
* interleaved or not. We define an iMCU row as v_samp_factor DCT block
* rows of each component. Therefore, the IDCT output contains
* v_samp_factor * DCT_v_scaled_size sample rows of a component per iMCU row.
*/
JSAMPLE * sample_range_limit; /* table for fast range-limiting */
/*
* These fields are valid during any one scan.
* They describe the components and MCUs actually appearing in the scan.
* Note that the decompressor output side must not use these fields.
*/
int comps_in_scan; /* # of JPEG components in this scan */
jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
/* *cur_comp_info[i] describes component that appears i'th in SOS */
JDIMENSION MCUs_per_row; /* # of MCUs across the image */
JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
int blocks_in_MCU; /* # of DCT blocks per MCU */
int MCU_membership[D_MAX_BLOCKS_IN_MCU];
/* MCU_membership[i] is index in cur_comp_info of component owning */
/* i'th block in an MCU */
int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
/* These fields are derived from Se of first SOS marker.
*/
int block_size; /* the basic DCT block size: 1..16 */
const int * natural_order; /* natural-order position array for entropy decode */
int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */
/* This field is shared between entropy decoder and marker parser.
* It is either zero or the code of a JPEG marker that has been
* read from the data source, but has not yet been processed.
*/
int unread_marker;
/*
* Links to decompression subobjects (methods, private variables of modules)
*/
struct jpeg_decomp_master * master;
struct jpeg_d_main_controller * main;
struct jpeg_d_coef_controller * coef;
struct jpeg_d_post_controller * post;
struct jpeg_input_controller * inputctl;
struct jpeg_marker_reader * marker;
struct jpeg_entropy_decoder * entropy;
struct jpeg_inverse_dct * idct;
struct jpeg_upsampler * upsample;
struct jpeg_color_deconverter * cconvert;
struct jpeg_color_quantizer * cquantize;
};
/* "Object" declarations for JPEG modules that may be supplied or called
* directly by the surrounding application.
* As with all objects in the JPEG library, these structs only define the
* publicly visible methods and state variables of a module. Additional
* private fields may exist after the public ones.
*/
/* Error handler object */
struct jpeg_error_mgr {
/* Error exit handler: does not return to caller */
JMETHOD(noreturn_t, error_exit, (j_common_ptr cinfo));
/* Conditionally emit a trace or warning message */
JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
/* Routine that actually outputs a trace or error message */
JMETHOD(void, output_message, (j_common_ptr cinfo));
/* Format a message string for the most recent JPEG error or message */
JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
#define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
/* Reset error state variables at start of a new image */
JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
/* The message ID code and any parameters are saved here.
* A message can have one string parameter or up to 8 int parameters.
*/
int msg_code;
#define JMSG_STR_PARM_MAX 80
union {
int i[8];
char s[JMSG_STR_PARM_MAX];
} msg_parm;
/* Standard state variables for error facility */
int trace_level; /* max msg_level that will be displayed */
/* For recoverable corrupt-data errors, we emit a warning message,
* but keep going unless emit_message chooses to abort. emit_message
* should count warnings in num_warnings. The surrounding application
* can check for bad data by seeing if num_warnings is nonzero at the
* end of processing.
*/
long num_warnings; /* number of corrupt-data warnings */
/* These fields point to the table(s) of error message strings.
* An application can change the table pointer to switch to a different
* message list (typically, to change the language in which errors are
* reported). Some applications may wish to add additional error codes
* that will be handled by the JPEG library error mechanism; the second
* table pointer is used for this purpose.
*
* First table includes all errors generated by JPEG library itself.
* Error code 0 is reserved for a "no such error string" message.
*/
const char * const * jpeg_message_table; /* Library errors */
int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
/* Second table can be added by application (see cjpeg/djpeg for example).
* It contains strings numbered first_addon_message..last_addon_message.
*/
const char * const * addon_message_table; /* Non-library errors */
int first_addon_message; /* code for first string in addon table */
int last_addon_message; /* code for last string in addon table */
};
/* Progress monitor object */
struct jpeg_progress_mgr {
JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
long pass_counter; /* work units completed in this pass */
long pass_limit; /* total number of work units in this pass */
int completed_passes; /* passes completed so far */
int total_passes; /* total number of passes expected */
};
/* Data destination object for compression */
struct jpeg_destination_mgr {
JOCTET * next_output_byte; /* => next byte to write in buffer */
size_t free_in_buffer; /* # of byte spaces remaining in buffer */
JMETHOD(void, init_destination, (j_compress_ptr cinfo));
JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
JMETHOD(void, term_destination, (j_compress_ptr cinfo));
};
/* Data source object for decompression */
struct jpeg_source_mgr {
const JOCTET * next_input_byte; /* => next byte to read from buffer */
size_t bytes_in_buffer; /* # of bytes remaining in buffer */
JMETHOD(void, init_source, (j_decompress_ptr cinfo));
JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
JMETHOD(void, term_source, (j_decompress_ptr cinfo));
};
/* Memory manager object.
* Allocates "small" objects (a few K total), "large" objects (tens of K),
* and "really big" objects (virtual arrays with backing store if needed).
* The memory manager does not allow individual objects to be freed; rather,
* each created object is assigned to a pool, and whole pools can be freed
* at once. This is faster and more convenient than remembering exactly what
* to free, especially where malloc()/free() are not too speedy.
* NB: alloc routines never return NULL. They exit to error_exit if not
* successful.
*/
#define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
#define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
#define JPOOL_NUMPOOLS 2
typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
typedef struct jvirt_barray_control * jvirt_barray_ptr;
struct jpeg_memory_mgr {
/* Method pointers */
JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
size_t sizeofobject));
JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
size_t sizeofobject));
JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
JDIMENSION samplesperrow,
JDIMENSION numrows));
JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
JDIMENSION blocksperrow,
JDIMENSION numrows));
JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
int pool_id,
boolean pre_zero,
JDIMENSION samplesperrow,
JDIMENSION numrows,
JDIMENSION maxaccess));
JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
int pool_id,
boolean pre_zero,
JDIMENSION blocksperrow,
JDIMENSION numrows,
JDIMENSION maxaccess));
JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
jvirt_sarray_ptr ptr,
JDIMENSION start_row,
JDIMENSION num_rows,
boolean writable));
JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
jvirt_barray_ptr ptr,
JDIMENSION start_row,
JDIMENSION num_rows,
boolean writable));
JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
JMETHOD(void, self_destruct, (j_common_ptr cinfo));
/* Limit on memory allocation for this JPEG object. (Note that this is
* merely advisory, not a guaranteed maximum; it only affects the space
* used for virtual-array buffers.) May be changed by outer application
* after creating the JPEG object.
*/
long max_memory_to_use;
/* Maximum allocation request accepted by alloc_large. */
long max_alloc_chunk;
};
/* Routine signature for application-supplied marker processing methods.
* Need not pass marker code since it is stored in cinfo->unread_marker.
*/
typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
/* Declarations for routines called by application.
* The JPP macro hides prototype parameters from compilers that can't cope.
* Note JPP requires double parentheses.
*/
#ifdef HAVE_PROTOTYPES
#define JPP(arglist) arglist
#else
#define JPP(arglist) ()
#endif
/* Short forms of external names for systems with brain-damaged linkers.
* We shorten external names to be unique in the first six letters, which
* is good enough for all known systems.
* (If your compiler itself needs names to be unique in less than 15
* characters, you are out of luck. Get a better compiler.)
*/
#ifdef NEED_SHORT_EXTERNAL_NAMES
#define jpeg_std_error jStdError
#define jpeg_CreateCompress jCreaCompress
#define jpeg_CreateDecompress jCreaDecompress
#define jpeg_destroy_compress jDestCompress
#define jpeg_destroy_decompress jDestDecompress
#define jpeg_stdio_dest jStdDest
#define jpeg_stdio_src jStdSrc
#define jpeg_mem_dest jMemDest
#define jpeg_mem_src jMemSrc
#define jpeg_set_defaults jSetDefaults
#define jpeg_set_colorspace jSetColorspace
#define jpeg_default_colorspace jDefColorspace
#define jpeg_set_quality jSetQuality
#define jpeg_set_linear_quality jSetLQuality
#define jpeg_default_qtables jDefQTables
#define jpeg_add_quant_table jAddQuantTable
#define jpeg_quality_scaling jQualityScaling
#define jpeg_simple_progression jSimProgress
#define jpeg_suppress_tables jSuppressTables
#define jpeg_alloc_quant_table jAlcQTable
#define jpeg_alloc_huff_table jAlcHTable
#define jpeg_std_huff_table jStdHTable
#define jpeg_start_compress jStrtCompress
#define jpeg_write_scanlines jWrtScanlines
#define jpeg_finish_compress jFinCompress
#define jpeg_calc_jpeg_dimensions jCjpegDimensions
#define jpeg_write_raw_data jWrtRawData
#define jpeg_write_marker jWrtMarker
#define jpeg_write_m_header jWrtMHeader
#define jpeg_write_m_byte jWrtMByte
#define jpeg_write_tables jWrtTables
#define jpeg_read_header jReadHeader
#define jpeg_start_decompress jStrtDecompress
#define jpeg_read_scanlines jReadScanlines
#define jpeg_finish_decompress jFinDecompress
#define jpeg_read_raw_data jReadRawData
#define jpeg_has_multiple_scans jHasMultScn
#define jpeg_start_output jStrtOutput
#define jpeg_finish_output jFinOutput
#define jpeg_input_complete jInComplete
#define jpeg_new_colormap jNewCMap
#define jpeg_consume_input jConsumeInput
#define jpeg_core_output_dimensions jCoreDimensions
#define jpeg_calc_output_dimensions jCalcDimensions
#define jpeg_save_markers jSaveMarkers
#define jpeg_set_marker_processor jSetMarker
#define jpeg_read_coefficients jReadCoefs
#define jpeg_write_coefficients jWrtCoefs
#define jpeg_copy_critical_parameters jCopyCrit
#define jpeg_abort_compress jAbrtCompress
#define jpeg_abort_decompress jAbrtDecompress
#define jpeg_abort jAbort
#define jpeg_destroy jDestroy
#define jpeg_resync_to_restart jResyncRestart
#endif /* NEED_SHORT_EXTERNAL_NAMES */
/* Default error-management setup */
EXTERN(struct jpeg_error_mgr *) jpeg_std_error
JPP((struct jpeg_error_mgr * err));
/* Initialization of JPEG compression objects.
* jpeg_create_compress() and jpeg_create_decompress() are the exported
* names that applications should call. These expand to calls on
* jpeg_CreateCompress and jpeg_CreateDecompress with additional information
* passed for version mismatch checking.
* NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
*/
#define jpeg_create_compress(cinfo) \
jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
(size_t) sizeof(struct jpeg_compress_struct))
#define jpeg_create_decompress(cinfo) \
jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
(size_t) sizeof(struct jpeg_decompress_struct))
EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo,
int version, size_t structsize));
EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo,
int version, size_t structsize));
/* Destruction of JPEG compression objects */
EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo));
EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
/* Standard data source and destination managers: stdio streams. */
/* Caller is responsible for opening the file before and closing after. */
EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile));
/* Data source and destination managers: memory buffers. */
EXTERN(void) jpeg_mem_dest JPP((j_compress_ptr cinfo,
unsigned char ** outbuffer,
size_t * outsize));
EXTERN(void) jpeg_mem_src JPP((j_decompress_ptr cinfo,
const unsigned char * inbuffer,
size_t insize));
/* Default parameter setup for compression */
EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo));
/* Compression parameter setup aids */
EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo,
J_COLOR_SPACE colorspace));
EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo));
EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
boolean force_baseline));
EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
int scale_factor,
boolean force_baseline));
EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo,
boolean force_baseline));
EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
const unsigned int *basic_table,