4
* Copyright (C) 1991-1995, Thomas G. Lane.
5
* This file is part of the Independent JPEG Group's software.
6
* For conditions of distribution and use, see the accompanying README file.
8
* This file defines the application interface for the JPEG library.
9
* Most applications using the library need only include this file,
10
* and perhaps jerror.h if they want to know the exact error codes.
16
typedef unsigned char boolean;
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.
24
#ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */
25
#include "../jpeg-6/jconfig.h" /* widely used configuration options */
27
#include "../jpeg-6/jmorecfg.h" /* seldom changed options */
30
/* Version ID for the JPEG library.
31
* Might be useful for tests like "#if JPEG_LIB_VERSION >= 60".
34
#define JPEG_LIB_VERSION 60 /* Version 6 */
37
/* Various constants determining the sizes of things.
38
* All of these are specified by the JPEG standard, so don't change them
39
* if you want to be compatible.
42
#define DCTSIZE 8 /* The basic DCT block is 8x8 samples */
43
#define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
44
#define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
45
#define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
46
#define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
47
#define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
48
#define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
49
/* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
50
* the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
51
* If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
52
* to handle it. We even let you do this from the jconfig.h file. However,
53
* we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
54
* sometimes emits noncompliant files doesn't mean you should too.
56
#define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */
57
#ifndef D_MAX_BLOCKS_IN_MCU
58
#define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */
62
/* This macro is used to declare a "method", that is, a function pointer.
63
* We want to supply prototype parameters if the compiler can cope.
64
* Note that the arglist parameter must be parenthesized!
67
#ifdef HAVE_PROTOTYPES
68
#define JMETHOD(type,methodname,arglist) type (*methodname) arglist
70
#define JMETHOD(type,methodname,arglist) type (*methodname) ()
74
/* Data structures for images (arrays of samples and of DCT coefficients).
75
* On 80x86 machines, the image arrays are too big for near pointers,
76
* but the pointer arrays can fit in near memory.
79
typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */
80
typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */
81
typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
83
typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
84
typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */
85
typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
86
typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
88
typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */
91
/* Types for JPEG compression parameters and working tables. */
94
/* DCT coefficient quantization tables. */
97
/* This field directly represents the contents of a JPEG DQT marker.
98
* Note: the values are always given in zigzag order.
100
UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */
101
/* This field is used only during compression. It's initialized FALSE when
102
* the table is created, and set TRUE when it's been output to the file.
103
* You could suppress output of a table by setting this to TRUE.
104
* (See jpeg_suppress_tables for an example.)
106
boolean sent_table; /* TRUE when table has been output */
110
/* Huffman coding tables. */
113
/* These two fields directly represent the contents of a JPEG DHT marker */
114
UINT8 bits[17]; /* bits[k] = # of symbols with codes of */
115
/* length k bits; bits[0] is unused */
116
UINT8 huffval[256]; /* The symbols, in order of incr code length */
117
/* This field is used only during compression. It's initialized FALSE when
118
* the table is created, and set TRUE when it's been output to the file.
119
* You could suppress output of a table by setting this to TRUE.
120
* (See jpeg_suppress_tables for an example.)
122
boolean sent_table; /* TRUE when table has been output */
126
/* Basic info about one component (color channel). */
129
/* These values are fixed over the whole image. */
130
/* For compression, they must be supplied by parameter setup; */
131
/* for decompression, they are read from the SOF marker. */
132
int component_id; /* identifier for this component (0..255) */
133
int component_index; /* its index in SOF or cinfo->comp_info[] */
134
int h_samp_factor; /* horizontal sampling factor (1..4) */
135
int v_samp_factor; /* vertical sampling factor (1..4) */
136
int quant_tbl_no; /* quantization table selector (0..3) */
137
/* These values may vary between scans. */
138
/* For compression, they must be supplied by parameter setup; */
139
/* for decompression, they are read from the SOS marker. */
140
/* The decompressor output side may not use these variables. */
141
int dc_tbl_no; /* DC entropy table selector (0..3) */
142
int ac_tbl_no; /* AC entropy table selector (0..3) */
144
/* Remaining fields should be treated as private by applications. */
146
/* These values are computed during compression or decompression startup: */
147
/* Component's size in DCT blocks.
148
* Any dummy blocks added to complete an MCU are not counted; therefore
149
* these values do not depend on whether a scan is interleaved or not.
151
JDIMENSION width_in_blocks;
152
JDIMENSION height_in_blocks;
153
/* Size of a DCT block in samples. Always DCTSIZE for compression.
154
* For decompression this is the size of the output from one DCT block,
155
* reflecting any scaling we choose to apply during the IDCT step.
156
* Values of 1,2,4,8 are likely to be supported. Note that different
157
* components may receive different IDCT scalings.
160
/* The downsampled dimensions are the component's actual, unpadded number
161
* of samples at the main buffer (preprocessing/compression interface), thus
162
* downsampled_width = ceil(image_width * Hi/Hmax)
163
* and similarly for height. For decompression, IDCT scaling is included, so
164
* downsampled_width = ceil(image_width * Hi/Hmax * DCT_scaled_size/DCTSIZE)
166
JDIMENSION downsampled_width; /* actual width in samples */
167
JDIMENSION downsampled_height; /* actual height in samples */
168
/* This flag is used only for decompression. In cases where some of the
169
* components will be ignored (eg grayscale output from YCbCr image),
170
* we can skip most computations for the unused components.
172
boolean component_needed; /* do we need the value of this component? */
174
/* These values are computed before starting a scan of the component. */
175
/* The decompressor output side may not use these variables. */
176
int MCU_width; /* number of blocks per MCU, horizontally */
177
int MCU_height; /* number of blocks per MCU, vertically */
178
int MCU_blocks; /* MCU_width * MCU_height */
179
int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_scaled_size */
180
int last_col_width; /* # of non-dummy blocks across in last MCU */
181
int last_row_height; /* # of non-dummy blocks down in last MCU */
183
/* Saved quantization table for component; NULL if none yet saved.
184
* See jdinput.c comments about the need for this information.
185
* This field is not currently used by the compressor.
187
JQUANT_TBL * quant_table;
189
/* Private per-component storage for DCT or IDCT subsystem. */
191
} jpeg_component_info;
194
/* The script for encoding a multiple-scan file is an array of these: */
197
int comps_in_scan; /* number of components encoded in this scan */
198
int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
199
int Ss, Se; /* progressive JPEG spectral selection parms */
200
int Ah, Al; /* progressive JPEG successive approx. parms */
204
/* Known color spaces. */
207
JCS_UNKNOWN, /* error/unspecified */
208
JCS_GRAYSCALE, /* monochrome */
209
JCS_RGB, /* red/green/blue */
210
JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */
211
JCS_CMYK, /* C/M/Y/K */
212
JCS_YCCK /* Y/Cb/Cr/K */
215
/* DCT/IDCT algorithm options. */
218
JDCT_ISLOW, /* slow but accurate integer algorithm */
219
JDCT_IFAST, /* faster, less accurate integer method */
220
JDCT_FLOAT /* floating-point: accurate, fast on fast HW */
223
#ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
224
#define JDCT_DEFAULT JDCT_ISLOW
226
#ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
227
#define JDCT_FASTEST JDCT_IFAST
230
/* Dithering options for decompression. */
233
JDITHER_NONE, /* no dithering */
234
JDITHER_ORDERED, /* simple ordered dither */
235
JDITHER_FS /* Floyd-Steinberg error diffusion dither */
239
/* Common fields between JPEG compression and decompression master structs. */
241
#define jpeg_common_fields \
242
struct jpeg_error_mgr * err; /* Error handler module */\
243
struct jpeg_memory_mgr * mem; /* Memory manager module */\
244
struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
245
boolean is_decompressor; /* so common code can tell which is which */\
246
int global_state /* for checking call sequence validity */
248
/* Routines that are to be used by both halves of the library are declared
249
* to receive a pointer to this structure. There are no actual instances of
250
* jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
252
struct jpeg_common_struct {
253
jpeg_common_fields; /* Fields common to both master struct types */
254
/* Additional fields follow in an actual jpeg_compress_struct or
255
* jpeg_decompress_struct. All three structs must agree on these
256
* initial fields! (This would be a lot cleaner in C++.)
260
typedef struct jpeg_common_struct * j_common_ptr;
261
typedef struct jpeg_compress_struct * j_compress_ptr;
262
typedef struct jpeg_decompress_struct * j_decompress_ptr;
265
/* Master record for a compression instance */
267
struct jpeg_compress_struct {
268
jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */
270
/* Destination for compressed data */
271
struct jpeg_destination_mgr * dest;
273
/* Description of source image --- these fields must be filled in by
274
* outer application before starting compression. in_color_space must
275
* be correct before you can even call jpeg_set_defaults().
278
JDIMENSION image_width; /* input image width */
279
JDIMENSION image_height; /* input image height */
280
int input_components; /* # of color components in input image */
281
J_COLOR_SPACE in_color_space; /* colorspace of input image */
283
double input_gamma; /* image gamma of input image */
285
/* Compression parameters --- these fields must be set before calling
286
* jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
287
* initialize everything to reasonable defaults, then changing anything
288
* the application specifically wants to change. That way you won't get
289
* burnt when new parameters are added. Also note that there are several
290
* helper routines to simplify changing parameters.
293
int data_precision; /* bits of precision in image data */
295
int num_components; /* # of color components in JPEG image */
296
J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
298
jpeg_component_info * comp_info;
299
/* comp_info[i] describes component that appears i'th in SOF */
301
JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
302
/* ptrs to coefficient quantization tables, or NULL if not defined */
304
JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
305
JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
306
/* ptrs to Huffman coding tables, or NULL if not defined */
308
UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
309
UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
310
UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
312
int num_scans; /* # of entries in scan_info array */
313
const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */
314
/* The default value of scan_info is NULL, which causes a single-scan
315
* sequential JPEG file to be emitted. To create a multi-scan file,
316
* set num_scans and scan_info to point to an array of scan definitions.
319
boolean raw_data_in; /* TRUE=caller supplies downsampled data */
320
boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
321
boolean optimize_coding; /* TRUE=optimize entropy encoding parms */
322
boolean CCIR601_sampling; /* TRUE=first samples are cosited */
323
int smoothing_factor; /* 1..100, or 0 for no input smoothing */
324
J_DCT_METHOD dct_method; /* DCT algorithm selector */
326
/* The restart interval can be specified in absolute MCUs by setting
327
* restart_interval, or in MCU rows by setting restart_in_rows
328
* (in which case the correct restart_interval will be figured
331
unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
332
int restart_in_rows; /* if > 0, MCU rows per restart interval */
334
/* Parameters controlling emission of special markers. */
336
boolean write_JFIF_header; /* should a JFIF marker be written? */
337
/* These three values are not used by the JPEG code, merely copied */
338
/* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
339
/* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
340
/* ratio is defined by X_density/Y_density even when density_unit=0. */
341
UINT8 density_unit; /* JFIF code for pixel size units */
342
UINT16 X_density; /* Horizontal pixel density */
343
UINT16 Y_density; /* Vertical pixel density */
344
boolean write_Adobe_marker; /* should an Adobe marker be written? */
346
/* State variable: index of next scanline to be written to
347
* jpeg_write_scanlines(). Application may use this to control its
348
* processing loop, e.g., "while (next_scanline < image_height)".
351
JDIMENSION next_scanline; /* 0 .. image_height-1 */
353
/* Remaining fields are known throughout compressor, but generally
354
* should not be touched by a surrounding application.
358
* These fields are computed during compression startup
360
boolean progressive_mode; /* TRUE if scan script uses progressive mode */
361
int max_h_samp_factor; /* largest h_samp_factor */
362
int max_v_samp_factor; /* largest v_samp_factor */
364
JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */
365
/* The coefficient controller receives data in units of MCU rows as defined
366
* for fully interleaved scans (whether the JPEG file is interleaved or not).
367
* There are v_samp_factor * DCTSIZE sample rows of each component in an
368
* "iMCU" (interleaved MCU) row.
372
* These fields are valid during any one scan.
373
* They describe the components and MCUs actually appearing in the scan.
375
int comps_in_scan; /* # of JPEG components in this scan */
376
jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
377
/* *cur_comp_info[i] describes component that appears i'th in SOS */
379
JDIMENSION MCUs_per_row; /* # of MCUs across the image */
380
JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
382
int blocks_in_MCU; /* # of DCT blocks per MCU */
383
int MCU_membership[C_MAX_BLOCKS_IN_MCU];
384
/* MCU_membership[i] is index in cur_comp_info of component owning */
385
/* i'th block in an MCU */
387
int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
390
* Links to compression subobjects (methods and private variables of modules)
392
struct jpeg_comp_master * master;
393
struct jpeg_c_main_controller * main;
394
struct jpeg_c_prep_controller * prep;
395
struct jpeg_c_coef_controller * coef;
396
struct jpeg_marker_writer * marker;
397
struct jpeg_color_converter * cconvert;
398
struct jpeg_downsampler * downsample;
399
struct jpeg_forward_dct * fdct;
400
struct jpeg_entropy_encoder * entropy;
404
/* Master record for a decompression instance */
406
struct jpeg_decompress_struct {
407
jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
409
/* Source of compressed data */
410
struct jpeg_source_mgr * src;
412
/* Basic description of image --- filled in by jpeg_read_header(). */
413
/* Application may inspect these values to decide how to process image. */
415
JDIMENSION image_width; /* nominal image width (from SOF marker) */
416
JDIMENSION image_height; /* nominal image height */
417
int num_components; /* # of color components in JPEG image */
418
J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
420
/* Decompression processing parameters --- these fields must be set before
421
* calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
422
* them to default values.
425
J_COLOR_SPACE out_color_space; /* colorspace for output */
427
unsigned int scale_num, scale_denom; /* fraction by which to scale image */
429
double output_gamma; /* image gamma wanted in output */
431
boolean buffered_image; /* TRUE=multiple output passes */
432
boolean raw_data_out; /* TRUE=downsampled data wanted */
434
J_DCT_METHOD dct_method; /* IDCT algorithm selector */
435
boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
436
boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
438
boolean quantize_colors; /* TRUE=colormapped output wanted */
439
/* the following are ignored if not quantize_colors: */
440
J_DITHER_MODE dither_mode; /* type of color dithering to use */
441
boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
442
int desired_number_of_colors; /* max # colors to use in created colormap */
443
/* these are significant only in buffered-image mode: */
444
boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
445
boolean enable_external_quant;/* enable future use of external colormap */
446
boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
448
/* Description of actual output image that will be returned to application.
449
* These fields are computed by jpeg_start_decompress().
450
* You can also use jpeg_calc_output_dimensions() to determine these values
451
* in advance of calling jpeg_start_decompress().
454
JDIMENSION output_width; /* scaled image width */
455
JDIMENSION output_height; /* scaled image height */
456
int out_color_components; /* # of color components in out_color_space */
457
int output_components; /* # of color components returned */
458
/* output_components is 1 (a colormap index) when quantizing colors;
459
* otherwise it equals out_color_components.
461
int rec_outbuf_height; /* min recommended height of scanline buffer */
462
/* If the buffer passed to jpeg_read_scanlines() is less than this many rows
463
* high, space and time will be wasted due to unnecessary data copying.
464
* Usually rec_outbuf_height will be 1 or 2, at most 4.
467
/* When quantizing colors, the output colormap is described by these fields.
468
* The application can supply a colormap by setting colormap non-NULL before
469
* calling jpeg_start_decompress; otherwise a colormap is created during
470
* jpeg_start_decompress or jpeg_start_output.
471
* The map has out_color_components rows and actual_number_of_colors columns.
473
int actual_number_of_colors; /* number of entries in use */
474
JSAMPARRAY colormap; /* The color map as a 2-D pixel array */
476
/* State variables: these variables indicate the progress of decompression.
477
* The application may examine these but must not modify them.
480
/* Row index of next scanline to be read from jpeg_read_scanlines().
481
* Application may use this to control its processing loop, e.g.,
482
* "while (output_scanline < output_height)".
484
JDIMENSION output_scanline; /* 0 .. output_height-1 */
486
/* Current input scan number and number of iMCU rows completed in scan.
487
* These indicate the progress of the decompressor input side.
489
int input_scan_number; /* Number of SOS markers seen so far */
490
JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
492
/* The "output scan number" is the notional scan being displayed by the
493
* output side. The decompressor will not allow output scan/row number
494
* to get ahead of input scan/row, but it can fall arbitrarily far behind.
496
int output_scan_number; /* Nominal scan number being displayed */
497
JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
499
/* Current progression status. coef_bits[c][i] indicates the precision
500
* with which component c's DCT coefficient i (in zigzag order) is known.
501
* It is -1 when no data has yet been received, otherwise it is the point
502
* transform (shift) value for the most recent scan of the coefficient
503
* (thus, 0 at completion of the progression).
504
* This pointer is NULL when reading a non-progressive file.
506
int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
508
/* Internal JPEG parameters --- the application usually need not look at
509
* these fields. Note that the decompressor output side may not use
510
* any parameters that can change between scans.
513
/* Quantization and Huffman tables are carried forward across input
514
* datastreams when processing abbreviated JPEG datastreams.
517
JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
518
/* ptrs to coefficient quantization tables, or NULL if not defined */
520
JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
521
JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
522
/* ptrs to Huffman coding tables, or NULL if not defined */
524
/* These parameters are never carried across datastreams, since they
525
* are given in SOF/SOS markers or defined to be reset by SOI.
528
int data_precision; /* bits of precision in image data */
530
jpeg_component_info * comp_info;
531
/* comp_info[i] describes component that appears i'th in SOF */
533
boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
534
boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
536
UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
537
UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
538
UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
540
unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
542
/* These fields record data obtained from optional markers recognized by
545
boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
546
/* Data copied from JFIF marker: */
547
UINT8 density_unit; /* JFIF code for pixel size units */
548
UINT16 X_density; /* Horizontal pixel density */
549
UINT16 Y_density; /* Vertical pixel density */
550
boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
551
UINT8 Adobe_transform; /* Color transform code from Adobe marker */
553
boolean CCIR601_sampling; /* TRUE=first samples are cosited */
555
/* Remaining fields are known throughout decompressor, but generally
556
* should not be touched by a surrounding application.
560
* These fields are computed during decompression startup
562
int max_h_samp_factor; /* largest h_samp_factor */
563
int max_v_samp_factor; /* largest v_samp_factor */
565
int min_DCT_scaled_size; /* smallest DCT_scaled_size of any component */
567
JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
568
/* The coefficient controller's input and output progress is measured in
569
* units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
570
* in fully interleaved JPEG scans, but are used whether the scan is
571
* interleaved or not. We define an iMCU row as v_samp_factor DCT block
572
* rows of each component. Therefore, the IDCT output contains
573
* v_samp_factor*DCT_scaled_size sample rows of a component per iMCU row.
576
JSAMPLE * sample_range_limit; /* table for fast range-limiting */
579
* These fields are valid during any one scan.
580
* They describe the components and MCUs actually appearing in the scan.
581
* Note that the decompressor output side must not use these fields.
583
int comps_in_scan; /* # of JPEG components in this scan */
584
jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
585
/* *cur_comp_info[i] describes component that appears i'th in SOS */
587
JDIMENSION MCUs_per_row; /* # of MCUs across the image */
588
JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
590
int blocks_in_MCU; /* # of DCT blocks per MCU */
591
int MCU_membership[D_MAX_BLOCKS_IN_MCU];
592
/* MCU_membership[i] is index in cur_comp_info of component owning */
593
/* i'th block in an MCU */
595
int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
597
/* This field is shared between entropy decoder and marker parser.
598
* It is either zero or the code of a JPEG marker that has been
599
* read from the data source, but has not yet been processed.
604
* Links to decompression subobjects (methods, private variables of modules)
606
struct jpeg_decomp_master * master;
607
struct jpeg_d_main_controller * main;
608
struct jpeg_d_coef_controller * coef;
609
struct jpeg_d_post_controller * post;
610
struct jpeg_input_controller * inputctl;
611
struct jpeg_marker_reader * marker;
612
struct jpeg_entropy_decoder * entropy;
613
struct jpeg_inverse_dct * idct;
614
struct jpeg_upsampler * upsample;
615
struct jpeg_color_deconverter * cconvert;
616
struct jpeg_color_quantizer * cquantize;
620
/* "Object" declarations for JPEG modules that may be supplied or called
621
* directly by the surrounding application.
622
* As with all objects in the JPEG library, these structs only define the
623
* publicly visible methods and state variables of a module. Additional
624
* private fields may exist after the public ones.
628
/* Error handler object */
630
struct jpeg_error_mgr {
631
/* Error exit handler: does not return to caller */
632
JMETHOD(void, error_exit, (j_common_ptr cinfo));
633
/* Conditionally emit a trace or warning message */
634
JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
635
/* Routine that actually outputs a trace or error message */
636
JMETHOD(void, output_message, (j_common_ptr cinfo));
637
/* Format a message string for the most recent JPEG error or message */
638
JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
639
#define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
640
/* Reset error state variables at start of a new image */
641
JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
643
/* The message ID code and any parameters are saved here.
644
* A message can have one string parameter or up to 8 int parameters.
647
#define JMSG_STR_PARM_MAX 80
650
char s[JMSG_STR_PARM_MAX];
653
/* Standard state variables for error facility */
655
int trace_level; /* max msg_level that will be displayed */
657
/* For recoverable corrupt-data errors, we emit a warning message,
658
* but keep going unless emit_message chooses to abort. emit_message
659
* should count warnings in num_warnings. The surrounding application
660
* can check for bad data by seeing if num_warnings is nonzero at the
663
long num_warnings; /* number of corrupt-data warnings */
665
/* These fields point to the table(s) of error message strings.
666
* An application can change the table pointer to switch to a different
667
* message list (typically, to change the language in which errors are
668
* reported). Some applications may wish to add additional error codes
669
* that will be handled by the JPEG library error mechanism; the second
670
* table pointer is used for this purpose.
672
* First table includes all errors generated by JPEG library itself.
673
* Error code 0 is reserved for a "no such error string" message.
675
const char * const * jpeg_message_table; /* Library errors */
676
int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
677
/* Second table can be added by application (see cjpeg/djpeg for example).
678
* It contains strings numbered first_addon_message..last_addon_message.
680
const char * const * addon_message_table; /* Non-library errors */
681
int first_addon_message; /* code for first string in addon table */
682
int last_addon_message; /* code for last string in addon table */
686
/* Progress monitor object */
688
struct jpeg_progress_mgr {
689
JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
691
long pass_counter; /* work units completed in this pass */
692
long pass_limit; /* total number of work units in this pass */
693
int completed_passes; /* passes completed so far */
694
int total_passes; /* total number of passes expected */
698
/* Data destination object for compression */
700
struct jpeg_destination_mgr {
701
JOCTET * next_output_byte; /* => next byte to write in buffer */
702
size_t free_in_buffer; /* # of byte spaces remaining in buffer */
704
JMETHOD(void, init_destination, (j_compress_ptr cinfo));
705
JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
706
JMETHOD(void, term_destination, (j_compress_ptr cinfo));
710
/* Data source object for decompression */
712
struct jpeg_source_mgr {
713
const JOCTET * next_input_byte; /* => next byte to read from buffer */
714
size_t bytes_in_buffer; /* # of bytes remaining in buffer */
716
JMETHOD(void, init_source, (j_decompress_ptr cinfo));
717
JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
718
JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
719
JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
720
JMETHOD(void, term_source, (j_decompress_ptr cinfo));
724
/* Memory manager object.
725
* Allocates "small" objects (a few K total), "large" objects (tens of K),
726
* and "really big" objects (virtual arrays with backing store if needed).
727
* The memory manager does not allow individual objects to be freed; rather,
728
* each created object is assigned to a pool, and whole pools can be freed
729
* at once. This is faster and more convenient than remembering exactly what
730
* to free, especially where malloc()/free() are not too speedy.
731
* NB: alloc routines never return NULL. They exit to error_exit if not
735
#define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
736
#define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
737
#define JPOOL_NUMPOOLS 2
739
typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
740
typedef struct jvirt_barray_control * jvirt_barray_ptr;
743
struct jpeg_memory_mgr {
744
/* Method pointers */
745
JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
746
size_t sizeofobject));
747
JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
748
size_t sizeofobject));
749
JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
750
JDIMENSION samplesperrow,
751
JDIMENSION numrows));
752
JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
753
JDIMENSION blocksperrow,
754
JDIMENSION numrows));
755
JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
758
JDIMENSION samplesperrow,
760
JDIMENSION maxaccess));
761
JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
764
JDIMENSION blocksperrow,
766
JDIMENSION maxaccess));
767
JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
768
JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
769
jvirt_sarray_ptr ptr,
770
JDIMENSION start_row,
773
JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
774
jvirt_barray_ptr ptr,
775
JDIMENSION start_row,
778
JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
779
JMETHOD(void, self_destruct, (j_common_ptr cinfo));
781
/* Limit on memory allocation for this JPEG object. (Note that this is
782
* merely advisory, not a guaranteed maximum; it only affects the space
783
* used for virtual-array buffers.) May be changed by outer application
784
* after creating the JPEG object.
786
long max_memory_to_use;
790
/* Routine signature for application-supplied marker processing methods.
791
* Need not pass marker code since it is stored in cinfo->unread_marker.
793
typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
796
/* Declarations for routines called by application.
797
* The JPP macro hides prototype parameters from compilers that can't cope.
798
* Note JPP requires double parentheses.
801
#ifdef HAVE_PROTOTYPES
802
#define JPP(arglist) arglist
804
#define JPP(arglist) ()
808
/* Short forms of external names for systems with brain-damaged linkers.
809
* We shorten external names to be unique in the first six letters, which
810
* is good enough for all known systems.
811
* (If your compiler itself needs names to be unique in less than 15
812
* characters, you are out of luck. Get a better compiler.)
815
#ifdef NEED_SHORT_EXTERNAL_NAMES
816
#define jpeg_std_error jStdError
817
#define jpeg_create_compress jCreaCompress
818
#define jpeg_create_decompress jCreaDecompress
819
#define jpeg_destroy_compress jDestCompress
820
#define jpeg_destroy_decompress jDestDecompress
821
#define jpeg_stdio_dest jStdDest
822
#define jpeg_stdio_src jStdSrc
823
#define jpeg_set_defaults jSetDefaults
824
#define jpeg_set_colorspace jSetColorspace
825
#define jpeg_default_colorspace jDefColorspace
826
#define jpeg_set_quality jSetQuality
827
#define jpeg_set_linear_quality jSetLQuality
828
#define jpeg_add_quant_table jAddQuantTable
829
#define jpeg_quality_scaling jQualityScaling
830
#define jpeg_simple_progression jSimProgress
831
#define jpeg_suppress_tables jSuppressTables
832
#define jpeg_alloc_quant_table jAlcQTable
833
#define jpeg_alloc_huff_table jAlcHTable
834
#define jpeg_start_compress jStrtCompress
835
#define jpeg_write_scanlines jWrtScanlines
836
#define jpeg_finish_compress jFinCompress
837
#define jpeg_write_raw_data jWrtRawData
838
#define jpeg_write_marker jWrtMarker
839
#define jpeg_write_tables jWrtTables
840
#define jpeg_read_header jReadHeader
841
#define jpeg_start_decompress jStrtDecompress
842
#define jpeg_read_scanlines jReadScanlines
843
#define jpeg_finish_decompress jFinDecompress
844
#define jpeg_read_raw_data jReadRawData
845
#define jpeg_has_multiple_scans jHasMultScn
846
#define jpeg_start_output jStrtOutput
847
#define jpeg_finish_output jFinOutput
848
#define jpeg_input_complete jInComplete
849
#define jpeg_new_colormap jNewCMap
850
#define jpeg_consume_input jConsumeInput
851
#define jpeg_calc_output_dimensions jCalcDimensions
852
#define jpeg_set_marker_processor jSetMarker
853
#define jpeg_read_coefficients jReadCoefs
854
#define jpeg_write_coefficients jWrtCoefs
855
#define jpeg_copy_critical_parameters jCopyCrit
856
#define jpeg_abort_compress jAbrtCompress
857
#define jpeg_abort_decompress jAbrtDecompress
858
#define jpeg_abort jAbort
859
#define jpeg_destroy jDestroy
860
#define jpeg_resync_to_restart jResyncRestart
861
#endif /* NEED_SHORT_EXTERNAL_NAMES */
864
/* Default error-management setup */
865
EXTERN struct jpeg_error_mgr *jpeg_std_error JPP((struct jpeg_error_mgr *err));
867
/* Initialization and destruction of JPEG compression objects */
868
/* NB: you must set up the error-manager BEFORE calling jpeg_create_xxx */
869
EXTERN void jpeg_create_compress JPP((j_compress_ptr cinfo));
870
EXTERN void jpeg_create_decompress JPP((j_decompress_ptr cinfo));
871
EXTERN void jpeg_destroy_compress JPP((j_compress_ptr cinfo));
872
EXTERN void jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
874
/* Standard data source and destination managers: stdio streams. */
875
/* Caller is responsible for opening the file before and closing after. */
876
EXTERN void jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
877
EXTERN void jpeg_stdio_src JPP((j_decompress_ptr cinfo, unsigned char *infile));
879
/* Default parameter setup for compression */
880
EXTERN void jpeg_set_defaults JPP((j_compress_ptr cinfo));
881
/* Compression parameter setup aids */
882
EXTERN void jpeg_set_colorspace JPP((j_compress_ptr cinfo,
883
J_COLOR_SPACE colorspace));
884
EXTERN void jpeg_default_colorspace JPP((j_compress_ptr cinfo));
885
EXTERN void jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
886
boolean force_baseline));
887
EXTERN void jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
889
boolean force_baseline));
890
EXTERN void jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
891
const unsigned int *basic_table,
893
boolean force_baseline));
894
EXTERN int jpeg_quality_scaling JPP((int quality));
895
EXTERN void jpeg_simple_progression JPP((j_compress_ptr cinfo));
896
EXTERN void jpeg_suppress_tables JPP((j_compress_ptr cinfo,
898
EXTERN JQUANT_TBL * jpeg_alloc_quant_table JPP((j_common_ptr cinfo));
899
EXTERN JHUFF_TBL * jpeg_alloc_huff_table JPP((j_common_ptr cinfo));
901
/* Main entry points for compression */
902
EXTERN void jpeg_start_compress JPP((j_compress_ptr cinfo,
903
boolean write_all_tables));
904
EXTERN JDIMENSION jpeg_write_scanlines JPP((j_compress_ptr cinfo,
905
JSAMPARRAY scanlines,
906
JDIMENSION num_lines));
907
EXTERN void jpeg_finish_compress JPP((j_compress_ptr cinfo));
909
/* Replaces jpeg_write_scanlines when writing raw downsampled data. */
910
EXTERN JDIMENSION jpeg_write_raw_data JPP((j_compress_ptr cinfo,
912
JDIMENSION num_lines));
914
/* Write a special marker. See libjpeg.doc concerning safe usage. */
915
EXTERN void jpeg_write_marker JPP((j_compress_ptr cinfo, int marker,
916
const JOCTET *dataptr, unsigned int datalen));
918
/* Alternate compression function: just write an abbreviated table file */
919
EXTERN void jpeg_write_tables JPP((j_compress_ptr cinfo));
921
/* Decompression startup: read start of JPEG datastream to see what's there */
922
EXTERN int jpeg_read_header JPP((j_decompress_ptr cinfo,
923
boolean require_image));
924
/* Return value is one of: */
925
#define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
926
#define JPEG_HEADER_OK 1 /* Found valid image datastream */
927
#define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
928
/* If you pass require_image = TRUE (normal case), you need not check for
929
* a TABLES_ONLY return code; an abbreviated file will cause an error exit.
930
* JPEG_SUSPENDED is only possible if you use a data source module that can
931
* give a suspension return (the stdio source module doesn't).
934
/* Main entry points for decompression */
935
EXTERN boolean jpeg_start_decompress JPP((j_decompress_ptr cinfo));
936
EXTERN JDIMENSION jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
937
JSAMPARRAY scanlines,
938
JDIMENSION max_lines));
939
EXTERN boolean jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
941
/* Replaces jpeg_read_scanlines when reading raw downsampled data. */
942
EXTERN JDIMENSION jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
944
JDIMENSION max_lines));
946
/* Additional entry points for buffered-image mode. */
947
EXTERN boolean jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
948
EXTERN boolean jpeg_start_output JPP((j_decompress_ptr cinfo,
950
EXTERN boolean jpeg_finish_output JPP((j_decompress_ptr cinfo));
951
EXTERN boolean jpeg_input_complete JPP((j_decompress_ptr cinfo));
952
EXTERN void jpeg_new_colormap JPP((j_decompress_ptr cinfo));
953
EXTERN int jpeg_consume_input JPP((j_decompress_ptr cinfo));
954
/* Return value is one of: */
955
/* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
956
#define JPEG_REACHED_SOS 1 /* Reached start of new scan */
957
#define JPEG_REACHED_EOI 2 /* Reached end of image */
958
#define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
959
#define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
961
/* Precalculate output dimensions for current decompression parameters. */
962
EXTERN void jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo));
964
/* Install a special processing method for COM or APPn markers. */
965
EXTERN void jpeg_set_marker_processor JPP((j_decompress_ptr cinfo,
967
jpeg_marker_parser_method routine));
969
/* Read or write raw DCT coefficients --- useful for lossless transcoding. */
970
EXTERN jvirt_barray_ptr * jpeg_read_coefficients JPP((j_decompress_ptr cinfo));
971
EXTERN void jpeg_write_coefficients JPP((j_compress_ptr cinfo,
972
jvirt_barray_ptr * coef_arrays));
973
EXTERN void jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo,
974
j_compress_ptr dstinfo));
976
/* If you choose to abort compression or decompression before completing
977
* jpeg_finish_(de)compress, then you need to clean up to release memory,
978
* temporary files, etc. You can just call jpeg_destroy_(de)compress
979
* if you're done with the JPEG object, but if you want to clean it up and
980
* reuse it, call this:
982
EXTERN void jpeg_abort_compress JPP((j_compress_ptr cinfo));
983
EXTERN void jpeg_abort_decompress JPP((j_decompress_ptr cinfo));
985
/* Generic versions of jpeg_abort and jpeg_destroy that work on either
986
* flavor of JPEG object. These may be more convenient in some places.
988
EXTERN void jpeg_abort JPP((j_common_ptr cinfo));
989
EXTERN void jpeg_destroy JPP((j_common_ptr cinfo));
991
/* Default restart-marker-resync procedure for use by data source modules */
992
EXTERN boolean jpeg_resync_to_restart JPP((j_decompress_ptr cinfo,
996
/* These marker codes are exported since applications and data source modules
997
* are likely to want to use them.
1000
#define JPEG_RST0 0xD0 /* RST0 marker code */
1001
#define JPEG_EOI 0xD9 /* EOI marker code */
1002
#define JPEG_APP0 0xE0 /* APP0 marker code */
1003
#define JPEG_COM 0xFE /* COM marker code */
1006
/* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1007
* for structure definitions that are never filled in, keep it quiet by
1008
* supplying dummy definitions for the various substructures.
1011
#ifdef INCOMPLETE_TYPES_BROKEN
1012
#ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
1013
struct jvirt_sarray_control { long dummy; };
1014
struct jvirt_barray_control { long dummy; };
1015
struct jpeg_comp_master { long dummy; };
1016
struct jpeg_c_main_controller { long dummy; };
1017
struct jpeg_c_prep_controller { long dummy; };
1018
struct jpeg_c_coef_controller { long dummy; };
1019
struct jpeg_marker_writer { long dummy; };
1020
struct jpeg_color_converter { long dummy; };
1021
struct jpeg_downsampler { long dummy; };
1022
struct jpeg_forward_dct { long dummy; };
1023
struct jpeg_entropy_encoder { long dummy; };
1024
struct jpeg_decomp_master { long dummy; };
1025
struct jpeg_d_main_controller { long dummy; };
1026
struct jpeg_d_coef_controller { long dummy; };
1027
struct jpeg_d_post_controller { long dummy; };
1028
struct jpeg_input_controller { long dummy; };
1029
struct jpeg_marker_reader { long dummy; };
1030
struct jpeg_entropy_decoder { long dummy; };
1031
struct jpeg_inverse_dct { long dummy; };
1032
struct jpeg_upsampler { long dummy; };
1033
struct jpeg_color_deconverter { long dummy; };
1034
struct jpeg_color_quantizer { long dummy; };
1035
#endif /* JPEG_INTERNALS */
1036
#endif /* INCOMPLETE_TYPES_BROKEN */
1040
* The JPEG library modules define JPEG_INTERNALS before including this file.
1041
* The internal structure declarations are read only when that is true.
1042
* Applications using the library should not include jpegint.h, but may wish
1043
* to include jerror.h.
1046
#ifdef JPEG_INTERNALS
1047
#include "../jpeg-6/jpegint.h" /* fetch private declarations */
1048
#include "../jpeg-6/jerror.h" /* fetch error codes too */
1051
#endif /* JPEGLIB_H */
added
removed
code/jpeg-6/jpeglib.h
