1/*
2 * jpeglib.h
3 *
4 * Copyright (C) 1991-1998, Thomas G. Lane.
5 * Modified 2002-2012 by Guido Vollbeding.
6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file.
8 *
9 * This file defines the application interface for the JPEG library.
10 * Most applications using the library need only include this file,
11 * and perhaps jerror.h if they want to know the exact error codes.
12 */
13
14#ifndef JPEGLIB_H
15#define JPEGLIB_H
16
17/*
18 * First we include the configuration files that record how this
19 * installation of the JPEG library is set up. jconfig.h can be
20 * generated automatically for many systems. jmorecfg.h contains
21 * manual configuration options that most people need not worry about.
22 */
23
24#ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */
25#include "jconfig.h" /* widely used configuration options */
26#endif
27#include "jmorecfg.h" /* seldom changed options */
28
29
30#ifdef __cplusplus
31#ifndef DONT_USE_EXTERN_C
32extern "C" {
33#endif
34#endif
35
36/* Version IDs for the JPEG library.
37 * Might be useful for tests like "#if JPEG_LIB_VERSION >= 90".
38 */
39
40#define JPEG_LIB_VERSION 90 /* Compatibility version 9.0 */
41#define JPEG_LIB_VERSION_MAJOR 9
42#define JPEG_LIB_VERSION_MINOR 0
43
44
45/* Various constants determining the sizes of things.
46 * All of these are specified by the JPEG standard, so don't change them
47 * if you want to be compatible.
48 */
49
50#define DCTSIZE 8 /* The basic DCT block is 8x8 coefficients */
51#define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
52#define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
53#define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
54#define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
55#define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
56#define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
57/* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
58 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
59 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
60 * to handle it. We even let you do this from the jconfig.h file. However,
61 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
62 * sometimes emits noncompliant files doesn't mean you should too.
63 */
64#define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */
65#ifndef D_MAX_BLOCKS_IN_MCU
66#define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */
67#endif
68
69
70/* Data structures for images (arrays of samples and of DCT coefficients).
71 * On 80x86 machines, the image arrays are too big for near pointers,
72 * but the pointer arrays can fit in near memory.
73 */
74
75typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */
76typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */
77typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
78
79typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
80typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */
81typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
82typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
83
84typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */
85
86
87/* Types for JPEG compression parameters and working tables. */
88
89
90/* DCT coefficient quantization tables. */
91
92typedef struct {
93 /* This array gives the coefficient quantizers in natural array order
94 * (not the zigzag order in which they are stored in a JPEG DQT marker).
95 * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
96 */
97 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */
98 /* This field is used only during compression. It's initialized FALSE when
99 * the table is created, and set TRUE when it's been output to the file.
100 * You could suppress output of a table by setting this to TRUE.
101 * (See jpeg_suppress_tables for an example.)
102 */
103 boolean sent_table; /* TRUE when table has been output */
104} JQUANT_TBL;
105
106
107/* Huffman coding tables. */
108
109typedef struct {
110 /* These two fields directly represent the contents of a JPEG DHT marker */
111 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */
112 /* length k bits; bits[0] is unused */
113 UINT8 huffval[256]; /* The symbols, in order of incr code length */
114 /* This field is used only during compression. It's initialized FALSE when
115 * the table is created, and set TRUE when it's been output to the file.
116 * You could suppress output of a table by setting this to TRUE.
117 * (See jpeg_suppress_tables for an example.)
118 */
119 boolean sent_table; /* TRUE when table has been output */
120} JHUFF_TBL;
121
122
123/* Basic info about one component (color channel). */
124
125typedef struct {
126 /* These values are fixed over the whole image. */
127 /* For compression, they must be supplied by parameter setup; */
128 /* for decompression, they are read from the SOF marker. */
129 int component_id; /* identifier for this component (0..255) */
130 int component_index; /* its index in SOF or cinfo->comp_info[] */
131 int h_samp_factor; /* horizontal sampling factor (1..4) */
132 int v_samp_factor; /* vertical sampling factor (1..4) */
133 int quant_tbl_no; /* quantization table selector (0..3) */
134 /* These values may vary between scans. */
135 /* For compression, they must be supplied by parameter setup; */
136 /* for decompression, they are read from the SOS marker. */
137 /* The decompressor output side may not use these variables. */
138 int dc_tbl_no; /* DC entropy table selector (0..3) */
139 int ac_tbl_no; /* AC entropy table selector (0..3) */
140
141 /* Remaining fields should be treated as private by applications. */
142
143 /* These values are computed during compression or decompression startup: */
144 /* Component's size in DCT blocks.
145 * Any dummy blocks added to complete an MCU are not counted; therefore
146 * these values do not depend on whether a scan is interleaved or not.
147 */
148 JDIMENSION width_in_blocks;
149 JDIMENSION height_in_blocks;
150 /* Size of a DCT block in samples,
151 * reflecting any scaling we choose to apply during the DCT step.
152 * Values from 1 to 16 are supported.
153 * Note that different components may receive different DCT scalings.
154 */
155 int DCT_h_scaled_size;
156 int DCT_v_scaled_size;
157 /* The downsampled dimensions are the component's actual, unpadded number
158 * of samples at the main buffer (preprocessing/compression interface);
159 * DCT scaling is included, so
160 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_h_scaled_size/DCTSIZE)
161 * and similarly for height.
162 */
163 JDIMENSION downsampled_width; /* actual width in samples */
164 JDIMENSION downsampled_height; /* actual height in samples */
165 /* This flag is used only for decompression. In cases where some of the
166 * components will be ignored (eg grayscale output from YCbCr image),
167 * we can skip most computations for the unused components.
168 */
169 boolean component_needed; /* do we need the value of this component? */
170
171 /* These values are computed before starting a scan of the component. */
172 /* The decompressor output side may not use these variables. */
173 int MCU_width; /* number of blocks per MCU, horizontally */
174 int MCU_height; /* number of blocks per MCU, vertically */
175 int MCU_blocks; /* MCU_width * MCU_height */
176 int MCU_sample_width; /* MCU width in samples: MCU_width * DCT_h_scaled_size */
177 int last_col_width; /* # of non-dummy blocks across in last MCU */
178 int last_row_height; /* # of non-dummy blocks down in last MCU */
179
180 /* Saved quantization table for component; NULL if none yet saved.
181 * See jdinput.c comments about the need for this information.
182 * This field is currently used only for decompression.
183 */
184 JQUANT_TBL * quant_table;
185
186 /* Private per-component storage for DCT or IDCT subsystem. */
187 void * dct_table;
188} jpeg_component_info;
189
190
191/* The script for encoding a multiple-scan file is an array of these: */
192
193typedef struct {
194 int comps_in_scan; /* number of components encoded in this scan */
195 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
196 int Ss, Se; /* progressive JPEG spectral selection parms */
197 int Ah, Al; /* progressive JPEG successive approx. parms */
198} jpeg_scan_info;
199
200/* The decompressor can save APPn and COM markers in a list of these: */
201
202typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr;
203
204struct jpeg_marker_struct {
205 jpeg_saved_marker_ptr next; /* next in list, or NULL */
206 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */
207 unsigned int original_length; /* # bytes of data in the file */
208 unsigned int data_length; /* # bytes of data saved at data[] */
209 JOCTET FAR * data; /* the data contained in the marker */
210 /* the marker length word is not counted in data_length or original_length */
211};
212
213/* Known color spaces. */
214
215typedef enum {
216 JCS_UNKNOWN, /* error/unspecified */
217 JCS_GRAYSCALE, /* monochrome */
218 JCS_RGB, /* red/green/blue */
219 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */
220 JCS_CMYK, /* C/M/Y/K */
221 JCS_YCCK /* Y/Cb/Cr/K */
222} J_COLOR_SPACE;
223
224/* Supported color transforms. */
225
226typedef enum {
227 JCT_NONE = 0,
228 JCT_SUBTRACT_GREEN = 1
229} J_COLOR_TRANSFORM;
230
231/* DCT/IDCT algorithm options. */
232
233typedef enum {
234 JDCT_ISLOW, /* slow but accurate integer algorithm */
235 JDCT_IFAST, /* faster, less accurate integer method */
236 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */
237} J_DCT_METHOD;
238
239#ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
240#define JDCT_DEFAULT JDCT_ISLOW
241#endif
242#ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
243#define JDCT_FASTEST JDCT_IFAST
244#endif
245
246/* Dithering options for decompression. */
247
248typedef enum {
249 JDITHER_NONE, /* no dithering */
250 JDITHER_ORDERED, /* simple ordered dither */
251 JDITHER_FS /* Floyd-Steinberg error diffusion dither */
252} J_DITHER_MODE;
253
254
255/* Common fields between JPEG compression and decompression master structs. */
256
257#define jpeg_common_fields \
258 struct jpeg_error_mgr * err; /* Error handler module */\
259 struct jpeg_memory_mgr * mem; /* Memory manager module */\
260 struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
261 void * client_data; /* Available for use by application */\
262 boolean is_decompressor; /* So common code can tell which is which */\
263 int global_state /* For checking call sequence validity */
264
265/* Routines that are to be used by both halves of the library are declared
266 * to receive a pointer to this structure. There are no actual instances of
267 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
268 */
269struct jpeg_common_struct {
270 jpeg_common_fields; /* Fields common to both master struct types */
271 /* Additional fields follow in an actual jpeg_compress_struct or
272 * jpeg_decompress_struct. All three structs must agree on these
273 * initial fields! (This would be a lot cleaner in C++.)
274 */
275};
276
277typedef struct jpeg_common_struct * j_common_ptr;
278typedef struct jpeg_compress_struct * j_compress_ptr;
279typedef struct jpeg_decompress_struct * j_decompress_ptr;
280
281
282/* Master record for a compression instance */
283
284struct jpeg_compress_struct {
285 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */
286
287 /* Destination for compressed data */
288 struct jpeg_destination_mgr * dest;
289
290 /* Description of source image --- these fields must be filled in by
291 * outer application before starting compression. in_color_space must
292 * be correct before you can even call jpeg_set_defaults().
293 */
294
295 JDIMENSION image_width; /* input image width */
296 JDIMENSION image_height; /* input image height */
297 int input_components; /* # of color components in input image */
298 J_COLOR_SPACE in_color_space; /* colorspace of input image */
299
300 double input_gamma; /* image gamma of input image */
301
302 /* Compression parameters --- these fields must be set before calling
303 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
304 * initialize everything to reasonable defaults, then changing anything
305 * the application specifically wants to change. That way you won't get
306 * burnt when new parameters are added. Also note that there are several
307 * helper routines to simplify changing parameters.
308 */
309
310 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
311
312 JDIMENSION jpeg_width; /* scaled JPEG image width */
313 JDIMENSION jpeg_height; /* scaled JPEG image height */
314 /* Dimensions of actual JPEG image that will be written to file,
315 * derived from input dimensions by scaling factors above.
316 * These fields are computed by jpeg_start_compress().
317 * You can also use jpeg_calc_jpeg_dimensions() to determine these values
318 * in advance of calling jpeg_start_compress().
319 */
320
321 int data_precision; /* bits of precision in image data */
322
323 int num_components; /* # of color components in JPEG image */
324 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
325
326 jpeg_component_info * comp_info;
327 /* comp_info[i] describes component that appears i'th in SOF */
328
329 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
330 int q_scale_factor[NUM_QUANT_TBLS];
331 /* ptrs to coefficient quantization tables, or NULL if not defined,
332 * and corresponding scale factors (percentage, initialized 100).
333 */
334
335 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
336 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
337 /* ptrs to Huffman coding tables, or NULL if not defined */
338
339 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
340 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
341 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
342
343 int num_scans; /* # of entries in scan_info array */
344 const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */
345 /* The default value of scan_info is NULL, which causes a single-scan
346 * sequential JPEG file to be emitted. To create a multi-scan file,
347 * set num_scans and scan_info to point to an array of scan definitions.
348 */
349
350 boolean raw_data_in; /* TRUE=caller supplies downsampled data */
351 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
352 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */
353 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
354 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
355 int smoothing_factor; /* 1..100, or 0 for no input smoothing */
356 J_DCT_METHOD dct_method; /* DCT algorithm selector */
357
358 /* The restart interval can be specified in absolute MCUs by setting
359 * restart_interval, or in MCU rows by setting restart_in_rows
360 * (in which case the correct restart_interval will be figured
361 * for each scan).
362 */
363 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
364 int restart_in_rows; /* if > 0, MCU rows per restart interval */
365
366 /* Parameters controlling emission of special markers. */
367
368 boolean write_JFIF_header; /* should a JFIF marker be written? */
369 UINT8 JFIF_major_version; /* What to write for the JFIF version number */
370 UINT8 JFIF_minor_version;
371 /* These three values are not used by the JPEG code, merely copied */
372 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
373 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
374 /* ratio is defined by X_density/Y_density even when density_unit=0. */
375 UINT8 density_unit; /* JFIF code for pixel size units */
376 UINT16 X_density; /* Horizontal pixel density */
377 UINT16 Y_density; /* Vertical pixel density */
378 boolean write_Adobe_marker; /* should an Adobe marker be written? */
379
380 J_COLOR_TRANSFORM color_transform;
381 /* Color transform identifier, writes LSE marker if nonzero */
382
383 /* State variable: index of next scanline to be written to
384 * jpeg_write_scanlines(). Application may use this to control its
385 * processing loop, e.g., "while (next_scanline < image_height)".
386 */
387
388 JDIMENSION next_scanline; /* 0 .. image_height-1 */
389
390 /* Remaining fields are known throughout compressor, but generally
391 * should not be touched by a surrounding application.
392 */
393
394 /*
395 * These fields are computed during compression startup
396 */
397 boolean progressive_mode; /* TRUE if scan script uses progressive mode */
398 int max_h_samp_factor; /* largest h_samp_factor */
399 int max_v_samp_factor; /* largest v_samp_factor */
400
401 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
402 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
403
404 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */
405 /* The coefficient controller receives data in units of MCU rows as defined
406 * for fully interleaved scans (whether the JPEG file is interleaved or not).
407 * There are v_samp_factor * DCTSIZE sample rows of each component in an
408 * "iMCU" (interleaved MCU) row.
409 */
410
411 /*
412 * These fields are valid during any one scan.
413 * They describe the components and MCUs actually appearing in the scan.
414 */
415 int comps_in_scan; /* # of JPEG components in this scan */
416 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
417 /* *cur_comp_info[i] describes component that appears i'th in SOS */
418
419 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
420 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
421
422 int blocks_in_MCU; /* # of DCT blocks per MCU */
423 int MCU_membership[C_MAX_BLOCKS_IN_MCU];
424 /* MCU_membership[i] is index in cur_comp_info of component owning */
425 /* i'th block in an MCU */
426
427 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
428
429 int block_size; /* the basic DCT block size: 1..16 */
430 const int * natural_order; /* natural-order position array */
431 int lim_Se; /* min( Se, DCTSIZE2-1 ) */
432
433 /*
434 * Links to compression subobjects (methods and private variables of modules)
435 */
436 struct jpeg_comp_master * master;
437 struct jpeg_c_main_controller * main;
438 struct jpeg_c_prep_controller * prep;
439 struct jpeg_c_coef_controller * coef;
440 struct jpeg_marker_writer * marker;
441 struct jpeg_color_converter * cconvert;
442 struct jpeg_downsampler * downsample;
443 struct jpeg_forward_dct * fdct;
444 struct jpeg_entropy_encoder * entropy;
445 jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */
446 int script_space_size;
447};
448
449
450/* Master record for a decompression instance */
451
452struct jpeg_decompress_struct {
453 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
454
455 /* Source of compressed data */
456 struct jpeg_source_mgr * src;
457
458 /* Basic description of image --- filled in by jpeg_read_header(). */
459 /* Application may inspect these values to decide how to process image. */
460
461 JDIMENSION image_width; /* nominal image width (from SOF marker) */
462 JDIMENSION image_height; /* nominal image height */
463 int num_components; /* # of color components in JPEG image */
464 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
465
466 /* Decompression processing parameters --- these fields must be set before
467 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
468 * them to default values.
469 */
470
471 J_COLOR_SPACE out_color_space; /* colorspace for output */
472
473 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
474
475 double output_gamma; /* image gamma wanted in output */
476
477 boolean buffered_image; /* TRUE=multiple output passes */
478 boolean raw_data_out; /* TRUE=downsampled data wanted */
479
480 J_DCT_METHOD dct_method; /* IDCT algorithm selector */
481 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
482 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
483
484 boolean quantize_colors; /* TRUE=colormapped output wanted */
485 /* the following are ignored if not quantize_colors: */
486 J_DITHER_MODE dither_mode; /* type of color dithering to use */
487 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
488 int desired_number_of_colors; /* max # colors to use in created colormap */
489 /* these are significant only in buffered-image mode: */
490 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
491 boolean enable_external_quant;/* enable future use of external colormap */
492 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
493
494 /* Description of actual output image that will be returned to application.
495 * These fields are computed by jpeg_start_decompress().
496 * You can also use jpeg_calc_output_dimensions() to determine these values
497 * in advance of calling jpeg_start_decompress().
498 */
499
500 JDIMENSION output_width; /* scaled image width */
501 JDIMENSION output_height; /* scaled image height */
502 int out_color_components; /* # of color components in out_color_space */
503 int output_components; /* # of color components returned */
504 /* output_components is 1 (a colormap index) when quantizing colors;
505 * otherwise it equals out_color_components.
506 */
507 int rec_outbuf_height; /* min recommended height of scanline buffer */
508 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
509 * high, space and time will be wasted due to unnecessary data copying.
510 * Usually rec_outbuf_height will be 1 or 2, at most 4.
511 */
512
513 /* When quantizing colors, the output colormap is described by these fields.
514 * The application can supply a colormap by setting colormap non-NULL before
515 * calling jpeg_start_decompress; otherwise a colormap is created during
516 * jpeg_start_decompress or jpeg_start_output.
517 * The map has out_color_components rows and actual_number_of_colors columns.
518 */
519 int actual_number_of_colors; /* number of entries in use */
520 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */
521
522 /* State variables: these variables indicate the progress of decompression.
523 * The application may examine these but must not modify them.
524 */
525
526 /* Row index of next scanline to be read from jpeg_read_scanlines().
527 * Application may use this to control its processing loop, e.g.,
528 * "while (output_scanline < output_height)".
529 */
530 JDIMENSION output_scanline; /* 0 .. output_height-1 */
531
532 /* Current input scan number and number of iMCU rows completed in scan.
533 * These indicate the progress of the decompressor input side.
534 */
535 int input_scan_number; /* Number of SOS markers seen so far */
536 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
537
538 /* The "output scan number" is the notional scan being displayed by the
539 * output side. The decompressor will not allow output scan/row number
540 * to get ahead of input scan/row, but it can fall arbitrarily far behind.
541 */
542 int output_scan_number; /* Nominal scan number being displayed */
543 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
544
545 /* Current progression status. coef_bits[c][i] indicates the precision
546 * with which component c's DCT coefficient i (in zigzag order) is known.
547 * It is -1 when no data has yet been received, otherwise it is the point
548 * transform (shift) value for the most recent scan of the coefficient
549 * (thus, 0 at completion of the progression).
550 * This pointer is NULL when reading a non-progressive file.
551 */
552 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
553
554 /* Internal JPEG parameters --- the application usually need not look at
555 * these fields. Note that the decompressor output side may not use
556 * any parameters that can change between scans.
557 */
558
559 /* Quantization and Huffman tables are carried forward across input
560 * datastreams when processing abbreviated JPEG datastreams.
561 */
562
563 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
564 /* ptrs to coefficient quantization tables, or NULL if not defined */
565
566 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
567 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
568 /* ptrs to Huffman coding tables, or NULL if not defined */
569
570 /* These parameters are never carried across datastreams, since they
571 * are given in SOF/SOS markers or defined to be reset by SOI.
572 */
573
574 int data_precision; /* bits of precision in image data */
575
576 jpeg_component_info * comp_info;
577 /* comp_info[i] describes component that appears i'th in SOF */
578
579 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */
580 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
581 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
582
583 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
584 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
585 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
586
587 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
588
589 /* These fields record data obtained from optional markers recognized by
590 * the JPEG library.
591 */
592 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
593 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
594 UINT8 JFIF_major_version; /* JFIF version number */
595 UINT8 JFIF_minor_version;
596 UINT8 density_unit; /* JFIF code for pixel size units */
597 UINT16 X_density; /* Horizontal pixel density */
598 UINT16 Y_density; /* Vertical pixel density */
599 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
600 UINT8 Adobe_transform; /* Color transform code from Adobe marker */
601
602 J_COLOR_TRANSFORM color_transform;
603 /* Color transform identifier derived from LSE marker, otherwise zero */
604
605 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
606
607 /* Aside from the specific data retained from APPn markers known to the
608 * library, the uninterpreted contents of any or all APPn and COM markers
609 * can be saved in a list for examination by the application.
610 */
611 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
612
613 /* Remaining fields are known throughout decompressor, but generally
614 * should not be touched by a surrounding application.
615 */
616
617 /*
618 * These fields are computed during decompression startup
619 */
620 int max_h_samp_factor; /* largest h_samp_factor */
621 int max_v_samp_factor; /* largest v_samp_factor */
622
623 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
624 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
625
626 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
627 /* The coefficient controller's input and output progress is measured in
628 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
629 * in fully interleaved JPEG scans, but are used whether the scan is
630 * interleaved or not. We define an iMCU row as v_samp_factor DCT block
631 * rows of each component. Therefore, the IDCT output contains
632 * v_samp_factor*DCT_v_scaled_size sample rows of a component per iMCU row.
633 */
634
635 JSAMPLE * sample_range_limit; /* table for fast range-limiting */
636
637 /*
638 * These fields are valid during any one scan.
639 * They describe the components and MCUs actually appearing in the scan.
640 * Note that the decompressor output side must not use these fields.
641 */
642 int comps_in_scan; /* # of JPEG components in this scan */
643 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
644 /* *cur_comp_info[i] describes component that appears i'th in SOS */
645
646 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
647 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
648
649 int blocks_in_MCU; /* # of DCT blocks per MCU */
650 int MCU_membership[D_MAX_BLOCKS_IN_MCU];
651 /* MCU_membership[i] is index in cur_comp_info of component owning */
652 /* i'th block in an MCU */
653
654 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
655
656 /* These fields are derived from Se of first SOS marker.
657 */
658 int block_size; /* the basic DCT block size: 1..16 */
659 const int * natural_order; /* natural-order position array for entropy decode */
660 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */
661
662 /* This field is shared between entropy decoder and marker parser.
663 * It is either zero or the code of a JPEG marker that has been
664 * read from the data source, but has not yet been processed.
665 */
666 int unread_marker;
667
668 /*
669 * Links to decompression subobjects (methods, private variables of modules)
670 */
671 struct jpeg_decomp_master * master;
672 struct jpeg_d_main_controller * main;
673 struct jpeg_d_coef_controller * coef;
674 struct jpeg_d_post_controller * post;
675 struct jpeg_input_controller * inputctl;
676 struct jpeg_marker_reader * marker;
677 struct jpeg_entropy_decoder * entropy;
678 struct jpeg_inverse_dct * idct;
679 struct jpeg_upsampler * upsample;
680 struct jpeg_color_deconverter * cconvert;
681 struct jpeg_color_quantizer * cquantize;
682};
683
684
685/* "Object" declarations for JPEG modules that may be supplied or called
686 * directly by the surrounding application.
687 * As with all objects in the JPEG library, these structs only define the
688 * publicly visible methods and state variables of a module. Additional
689 * private fields may exist after the public ones.
690 */
691
692
693/* Error handler object */
694
695struct jpeg_error_mgr {
696 /* Error exit handler: does not return to caller */
697 JMETHOD(noreturn_t, error_exit, (j_common_ptr cinfo));
698 /* Conditionally emit a trace or warning message */
699 JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
700 /* Routine that actually outputs a trace or error message */
701 JMETHOD(void, output_message, (j_common_ptr cinfo));
702 /* Format a message string for the most recent JPEG error or message */
703 JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
704#define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
705 /* Reset error state variables at start of a new image */
706 JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
707
708 /* The message ID code and any parameters are saved here.
709 * A message can have one string parameter or up to 8 int parameters.
710 */
711 int msg_code;
712#define JMSG_STR_PARM_MAX 80
713 union {
714 int i[8];
715 char s[JMSG_STR_PARM_MAX];
716 } msg_parm;
717
718 /* Standard state variables for error facility */
719
720 int trace_level; /* max msg_level that will be displayed */
721
722 /* For recoverable corrupt-data errors, we emit a warning message,
723 * but keep going unless emit_message chooses to abort. emit_message
724 * should count warnings in num_warnings. The surrounding application
725 * can check for bad data by seeing if num_warnings is nonzero at the
726 * end of processing.
727 */
728 long num_warnings; /* number of corrupt-data warnings */
729
730 /* These fields point to the table(s) of error message strings.
731 * An application can change the table pointer to switch to a different
732 * message list (typically, to change the language in which errors are
733 * reported). Some applications may wish to add additional error codes
734 * that will be handled by the JPEG library error mechanism; the second
735 * table pointer is used for this purpose.
736 *
737 * First table includes all errors generated by JPEG library itself.
738 * Error code 0 is reserved for a "no such error string" message.
739 */
740 const char * const * jpeg_message_table; /* Library errors */
741 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
742 /* Second table can be added by application (see cjpeg/djpeg for example).
743 * It contains strings numbered first_addon_message..last_addon_message.
744 */
745 const char * const * addon_message_table; /* Non-library errors */
746 int first_addon_message; /* code for first string in addon table */
747 int last_addon_message; /* code for last string in addon table */
748};
749
750
751/* Progress monitor object */
752
753struct jpeg_progress_mgr {
754 JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
755
756 long pass_counter; /* work units completed in this pass */
757 long pass_limit; /* total number of work units in this pass */
758 int completed_passes; /* passes completed so far */
759 int total_passes; /* total number of passes expected */
760};
761
762
763/* Data destination object for compression */
764
765struct jpeg_destination_mgr {
766 JOCTET * next_output_byte; /* => next byte to write in buffer */
767 size_t free_in_buffer; /* # of byte spaces remaining in buffer */
768
769 JMETHOD(void, init_destination, (j_compress_ptr cinfo));
770 JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
771 JMETHOD(void, term_destination, (j_compress_ptr cinfo));
772};
773
774
775/* Data source object for decompression */
776
777struct jpeg_source_mgr {
778 const JOCTET * next_input_byte; /* => next byte to read from buffer */
779 size_t bytes_in_buffer; /* # of bytes remaining in buffer */
780
781 JMETHOD(void, init_source, (j_decompress_ptr cinfo));
782 JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
783 JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
784 JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
785 JMETHOD(void, term_source, (j_decompress_ptr cinfo));
786};
787
788
789/* Memory manager object.
790 * Allocates "small" objects (a few K total), "large" objects (tens of K),
791 * and "really big" objects (virtual arrays with backing store if needed).
792 * The memory manager does not allow individual objects to be freed; rather,
793 * each created object is assigned to a pool, and whole pools can be freed
794 * at once. This is faster and more convenient than remembering exactly what
795 * to free, especially where malloc()/free() are not too speedy.
796 * NB: alloc routines never return NULL. They exit to error_exit if not
797 * successful.
798 */
799
800#define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
801#define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
802#define JPOOL_NUMPOOLS 2
803
804typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
805typedef struct jvirt_barray_control * jvirt_barray_ptr;
806
807
808struct jpeg_memory_mgr {
809 /* Method pointers */
810 JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
811 size_t sizeofobject));
812 JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
813 size_t sizeofobject));
814 JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
815 JDIMENSION samplesperrow,
816 JDIMENSION numrows));
817 JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
818 JDIMENSION blocksperrow,
819 JDIMENSION numrows));
820 JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
821 int pool_id,
822 boolean pre_zero,
823 JDIMENSION samplesperrow,
824 JDIMENSION numrows,
825 JDIMENSION maxaccess));
826 JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
827 int pool_id,
828 boolean pre_zero,
829 JDIMENSION blocksperrow,
830 JDIMENSION numrows,
831 JDIMENSION maxaccess));
832 JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
833 JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
834 jvirt_sarray_ptr ptr,
835 JDIMENSION start_row,
836 JDIMENSION num_rows,
837 boolean writable));
838 JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
839 jvirt_barray_ptr ptr,
840 JDIMENSION start_row,
841 JDIMENSION num_rows,
842 boolean writable));
843 JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
844 JMETHOD(void, self_destruct, (j_common_ptr cinfo));
845
846 /* Limit on memory allocation for this JPEG object. (Note that this is
847 * merely advisory, not a guaranteed maximum; it only affects the space
848 * used for virtual-array buffers.) May be changed by outer application
849 * after creating the JPEG object.
850 */
851 long max_memory_to_use;
852
853 /* Maximum allocation request accepted by alloc_large. */
854 long max_alloc_chunk;
855};
856
857
858/* Routine signature for application-supplied marker processing methods.
859 * Need not pass marker code since it is stored in cinfo->unread_marker.
860 */
861typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
862
863
864/* Declarations for routines called by application.
865 * The JPP macro hides prototype parameters from compilers that can't cope.
866 * Note JPP requires double parentheses.
867 */
868
869#ifdef HAVE_PROTOTYPES
870#define JPP(arglist) arglist
871#else
872#define JPP(arglist) ()
873#endif
874
875
876/* Short forms of external names for systems with brain-damaged linkers.
877 * We shorten external names to be unique in the first six letters, which
878 * is good enough for all known systems.
879 * (If your compiler itself needs names to be unique in less than 15
880 * characters, you are out of luck. Get a better compiler.)
881 */
882
883#ifdef NEED_SHORT_EXTERNAL_NAMES
884#define jpeg_std_error jStdError
885#define jpeg_CreateCompress jCreaCompress
886#define jpeg_CreateDecompress jCreaDecompress
887#define jpeg_destroy_compress jDestCompress
888#define jpeg_destroy_decompress jDestDecompress
889#define jpeg_stdio_dest jStdDest
890#define jpeg_stdio_src jStdSrc
891#define jpeg_mem_dest jMemDest
892#define jpeg_mem_src jMemSrc
893#define jpeg_set_defaults jSetDefaults
894#define jpeg_set_colorspace jSetColorspace
895#define jpeg_default_colorspace jDefColorspace
896#define jpeg_set_quality jSetQuality
897#define jpeg_set_linear_quality jSetLQuality
898#define jpeg_default_qtables jDefQTables
899#define jpeg_add_quant_table jAddQuantTable
900#define jpeg_quality_scaling jQualityScaling
901#define jpeg_simple_progression jSimProgress
902#define jpeg_suppress_tables jSuppressTables
903#define jpeg_alloc_quant_table jAlcQTable
904#define jpeg_alloc_huff_table jAlcHTable
905#define jpeg_start_compress jStrtCompress
906#define jpeg_write_scanlines jWrtScanlines
907#define jpeg_finish_compress jFinCompress
908#define jpeg_calc_jpeg_dimensions jCjpegDimensions
909#define jpeg_write_raw_data jWrtRawData
910#define jpeg_write_marker jWrtMarker
911#define jpeg_write_m_header jWrtMHeader
912#define jpeg_write_m_byte jWrtMByte
913#define jpeg_write_tables jWrtTables
914#define jpeg_read_header jReadHeader
915#define jpeg_start_decompress jStrtDecompress
916#define jpeg_read_scanlines jReadScanlines
917#define jpeg_finish_decompress jFinDecompress
918#define jpeg_read_raw_data jReadRawData
919#define jpeg_has_multiple_scans jHasMultScn
920#define jpeg_start_output jStrtOutput
921#define jpeg_finish_output jFinOutput
922#define jpeg_input_complete jInComplete
923#define jpeg_new_colormap jNewCMap
924#define jpeg_consume_input jConsumeInput
925#define jpeg_core_output_dimensions jCoreDimensions
926#define jpeg_calc_output_dimensions jCalcDimensions
927#define jpeg_save_markers jSaveMarkers
928#define jpeg_set_marker_processor jSetMarker
929#define jpeg_read_coefficients jReadCoefs
930#define jpeg_write_coefficients jWrtCoefs
931#define jpeg_copy_critical_parameters jCopyCrit
932#define jpeg_abort_compress jAbrtCompress
933#define jpeg_abort_decompress jAbrtDecompress
934#define jpeg_abort jAbort
935#define jpeg_destroy jDestroy
936#define jpeg_resync_to_restart jResyncRestart
937#endif /* NEED_SHORT_EXTERNAL_NAMES */
938
939
940/* Default error-management setup */
941EXTERN(struct jpeg_error_mgr *) jpeg_std_error
942 JPP((struct jpeg_error_mgr * err));
943
944/* Initialization of JPEG compression objects.
945 * jpeg_create_compress() and jpeg_create_decompress() are the exported
946 * names that applications should call. These expand to calls on
947 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
948 * passed for version mismatch checking.
949 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
950 */
951#define jpeg_create_compress(cinfo) \
952 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
953 (size_t) sizeof(struct jpeg_compress_struct))
954#define jpeg_create_decompress(cinfo) \
955 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
956 (size_t) sizeof(struct jpeg_decompress_struct))
957EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo,
958 int version, size_t structsize));
959EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo,
960 int version, size_t structsize));
961/* Destruction of JPEG compression objects */
962EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo));
963EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
964
965/* Standard data source and destination managers: stdio streams. */
966/* Caller is responsible for opening the file before and closing after. */
967EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
968EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile));
969
970/* Data source and destination managers: memory buffers. */
971EXTERN(void) jpeg_mem_dest JPP((j_compress_ptr cinfo,
972 unsigned char ** outbuffer,
973 unsigned long * outsize));
974EXTERN(void) jpeg_mem_src JPP((j_decompress_ptr cinfo,
975 unsigned char * inbuffer,
976 unsigned long insize));
977
978/* Default parameter setup for compression */
979EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo));
980/* Compression parameter setup aids */
981EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo,
982 J_COLOR_SPACE colorspace));
983EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo));
984EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
985 boolean force_baseline));
986EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
987 int scale_factor,
988 boolean force_baseline));
989EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo,
990 boolean force_baseline));
991EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
992 const unsigned int *basic_table,
993 int scale_factor,
994 boolean force_baseline));
995EXTERN(int) jpeg_quality_scaling JPP((int quality));
996EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo));
997EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo,
998 boolean suppress));
999EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo));
1000EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo));
1001
1002/* Main entry points for compression */
1003EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo,
1004 boolean write_all_tables));
1005EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo,
1006 JSAMPARRAY scanlines,
1007 JDIMENSION num_lines));
1008EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo));
1009
1010/* Precalculate JPEG dimensions for current compression parameters. */
1011EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo));
1012
1013/* Replaces jpeg_write_scanlines when writing raw downsampled data. */
1014EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo,
1015 JSAMPIMAGE data,
1016 JDIMENSION num_lines));
1017
1018/* Write a special marker. See libjpeg.txt concerning safe usage. */
1019EXTERN(void) jpeg_write_marker
1020 JPP((j_compress_ptr cinfo, int marker,
1021 const JOCTET * dataptr, unsigned int datalen));
1022/* Same, but piecemeal. */
1023EXTERN(void) jpeg_write_m_header
1024 JPP((j_compress_ptr cinfo, int marker, unsigned int datalen));
1025EXTERN(void) jpeg_write_m_byte
1026 JPP((j_compress_ptr cinfo, int val));
1027
1028/* Alternate compression function: just write an abbreviated table file */
1029EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo));
1030
1031/* Decompression startup: read start of JPEG datastream to see what's there */
1032EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo,
1033 boolean require_image));
1034/* Return value is one of: */
1035#define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
1036#define JPEG_HEADER_OK 1 /* Found valid image datastream */
1037#define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
1038/* If you pass require_image = TRUE (normal case), you need not check for
1039 * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
1040 * JPEG_SUSPENDED is only possible if you use a data source module that can
1041 * give a suspension return (the stdio source module doesn't).
1042 */
1043
1044/* Main entry points for decompression */
1045EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo));
1046EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
1047 JSAMPARRAY scanlines,
1048 JDIMENSION max_lines));
1049EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
1050
1051/* Replaces jpeg_read_scanlines when reading raw downsampled data. */
1052EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
1053 JSAMPIMAGE data,
1054 JDIMENSION max_lines));
1055
1056/* Additional entry points for buffered-image mode. */
1057EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
1058EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo,
1059 int scan_number));
1060EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo));
1061EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo));
1062EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo));
1063EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo));
1064/* Return value is one of: */
1065/* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
1066#define JPEG_REACHED_SOS 1 /* Reached start of new scan */
1067#define JPEG_REACHED_EOI 2 /* Reached end of image */
1068#define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
1069#define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
1070
1071/* Precalculate output dimensions for current decompression parameters. */
1072EXTERN(void) jpeg_core_output_dimensions JPP((j_decompress_ptr cinfo));
1073EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo));
1074
1075/* Control saving of COM and APPn markers into marker_list. */
1076EXTERN(void) jpeg_save_markers
1077 JPP((j_decompress_ptr cinfo, int marker_code,
1078 unsigned int length_limit));
1079
1080/* Install a special processing method for COM or APPn markers. */
1081EXTERN(void) jpeg_set_marker_processor
1082 JPP((j_decompress_ptr cinfo, int marker_code,
1083 jpeg_marker_parser_method routine));
1084
1085/* Read or write raw DCT coefficients --- useful for lossless transcoding. */
1086EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo));
1087EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo,
1088 jvirt_barray_ptr * coef_arrays));
1089EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo,
1090 j_compress_ptr dstinfo));
1091
1092/* If you choose to abort compression or decompression before completing
1093 * jpeg_finish_(de)compress, then you need to clean up to release memory,
1094 * temporary files, etc. You can just call jpeg_destroy_(de)compress
1095 * if you're done with the JPEG object, but if you want to clean it up and
1096 * reuse it, call this:
1097 */
1098EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo));
1099EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo));
1100
1101/* Generic versions of jpeg_abort and jpeg_destroy that work on either
1102 * flavor of JPEG object. These may be more convenient in some places.
1103 */
1104EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo));
1105EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo));
1106
1107/* Default restart-marker-resync procedure for use by data source modules */
1108EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo,
1109 int desired));
1110
1111
1112/* These marker codes are exported since applications and data source modules
1113 * are likely to want to use them.
1114 */
1115
1116#define JPEG_RST0 0xD0 /* RST0 marker code */
1117#define JPEG_EOI 0xD9 /* EOI marker code */
1118#define JPEG_APP0 0xE0 /* APP0 marker code */
1119#define JPEG_COM 0xFE /* COM marker code */
1120
1121
1122/* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1123 * for structure definitions that are never filled in, keep it quiet by
1124 * supplying dummy definitions for the various substructures.
1125 */
1126
1127#ifdef INCOMPLETE_TYPES_BROKEN
1128#ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
1129struct jvirt_sarray_control { long dummy; };
1130struct jvirt_barray_control { long dummy; };
1131struct jpeg_comp_master { long dummy; };
1132struct jpeg_c_main_controller { long dummy; };
1133struct jpeg_c_prep_controller { long dummy; };
1134struct jpeg_c_coef_controller { long dummy; };
1135struct jpeg_marker_writer { long dummy; };
1136struct jpeg_color_converter { long dummy; };
1137struct jpeg_downsampler { long dummy; };
1138struct jpeg_forward_dct { long dummy; };
1139struct jpeg_entropy_encoder { long dummy; };
1140struct jpeg_decomp_master { long dummy; };
1141struct jpeg_d_main_controller { long dummy; };
1142struct jpeg_d_coef_controller { long dummy; };
1143struct jpeg_d_post_controller { long dummy; };
1144struct jpeg_input_controller { long dummy; };
1145struct jpeg_marker_reader { long dummy; };
1146struct jpeg_entropy_decoder { long dummy; };
1147struct jpeg_inverse_dct { long dummy; };
1148struct jpeg_upsampler { long dummy; };
1149struct jpeg_color_deconverter { long dummy; };
1150struct jpeg_color_quantizer { long dummy; };
1151#endif /* JPEG_INTERNALS */
1152#endif /* INCOMPLETE_TYPES_BROKEN */
1153
1154
1155/*
1156 * The JPEG library modules define JPEG_INTERNALS before including this file.
1157 * The internal structure declarations are read only when that is true.
1158 * Applications using the library should not include jpegint.h, but may wish
1159 * to include jerror.h.
1160 */
1161
1162#ifdef JPEG_INTERNALS
1163#include "jpegint.h" /* fetch private declarations */
1164#include "jerror.h" /* fetch error codes too */
1165#endif
1166
1167#ifdef __cplusplus
1168#ifndef DONT_USE_EXTERN_C
1169}
1170#endif
1171#endif
1172
1173#endif /* JPEGLIB_H */
1174