1/*
2 * jpeglib.h
3 *
4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1991-1998, Thomas G. Lane.
6 * Modified 2002-2009 by Guido Vollbeding.
7 * Lossless JPEG Modifications:
8 * Copyright (C) 1999, Ken Murchison.
9 * libjpeg-turbo Modifications:
10 * Copyright (C) 2009-2011, 2013-2014, 2016-2017, 2020, 2022-2024,
11 D. R. Commander.
12 * Copyright (C) 2015, Google, Inc.
13 * For conditions of distribution and use, see the accompanying README.ijg
14 * file.
15 *
16 * This file defines the application interface for the JPEG library.
17 * Most applications using the library need only include this file,
18 * and perhaps jerror.h if they want to know the exact error codes.
19 */
20
21/* NOTE: This header file does not include stdio.h, despite the fact that it
22 * uses FILE and size_t. That is by design, since the libjpeg API predates the
23 * widespread adoption of ANSI/ISO C. Referring to libjpeg.txt, it is a
24 * documented requirement that calling programs "include system headers that
25 * define at least the typedefs FILE and size_t" before including jpeglib.h.
26 * Technically speaking, changing that requirement by including stdio.h here
27 * would break backward API compatibility. Please do not file bug reports,
28 * feature requests, or pull requests regarding this.
29 */
30
31#ifndef JPEGLIB_H
32#define JPEGLIB_H
33
34/*
35 * First we include the configuration files that record how this
36 * installation of the JPEG library is set up. jconfig.h can be
37 * generated automatically for many systems. jmorecfg.h contains
38 * manual configuration options that most people need not worry about.
39 */
40
41#ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */
42#include "jconfig.h" /* widely used configuration options */
43#endif
44#include "jmorecfg.h" /* seldom changed options */
45
46
47#ifdef __cplusplus
48#ifndef DONT_USE_EXTERN_C
49extern "C" {
50#endif
51#endif
52
53
54/* Various constants determining the sizes of things.
55 * All of these are specified by the JPEG standard, so don't change them
56 * if you want to be compatible.
57 */
58
59/* NOTE: In lossless mode, an MCU contains one or more samples rather than one
60 * or more 8x8 DCT blocks, so the term "data unit" is used to generically
61 * describe a sample in lossless mode or an 8x8 DCT block in lossy mode. To
62 * preserve backward API/ABI compatibility, the field and macro names retain
63 * the "block" terminology.
64 */
65
66#define DCTSIZE 8 /* The basic DCT block is 8x8 samples */
67#define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
68#define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
69#define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
70#define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
71#define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
72#define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
73/* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
74 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
75 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
76 * to handle it. We even let you do this from the jconfig.h file. However,
77 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
78 * sometimes emits noncompliant files doesn't mean you should too.
79 */
80#define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on data units/MCU */
81#ifndef D_MAX_BLOCKS_IN_MCU
82#define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on data units/MCU */
83#endif
84
85
86/* Data structures for images (arrays of samples and of DCT coefficients).
87 */
88
89typedef JSAMPLE *JSAMPROW; /* ptr to one image row of pixel samples with
90 2-bit through 8-bit data precision. */
91typedef JSAMPROW *JSAMPARRAY; /* ptr to some JSAMPLE rows (a 2-D JSAMPLE
92 array) */
93typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D JSAMPLE array: top index is color */
94
95typedef J12SAMPLE *J12SAMPROW; /* ptr to one image row of pixel samples
96 with 9-bit through 12-bit data
97 precision. */
98typedef J12SAMPROW *J12SAMPARRAY; /* ptr to some J12SAMPLE rows (a 2-D
99 J12SAMPLE array) */
100typedef J12SAMPARRAY *J12SAMPIMAGE; /* a 3-D J12SAMPLE array: top index is
101 color */
102
103typedef J16SAMPLE *J16SAMPROW; /* ptr to one image row of pixel samples
104 with 13-bit through 16-bit data
105 precision. */
106typedef J16SAMPROW *J16SAMPARRAY; /* ptr to some J16SAMPLE rows (a 2-D
107 J16SAMPLE array) */
108typedef J16SAMPARRAY *J16SAMPIMAGE; /* a 3-D J16SAMPLE array: top index is
109 color */
110
111typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
112typedef JBLOCK *JBLOCKROW; /* pointer to one row of coefficient blocks */
113typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
114typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
115
116typedef JCOEF *JCOEFPTR; /* useful in a couple of places */
117
118
119/* Types for JPEG compression parameters and working tables. */
120
121
122/* DCT coefficient quantization tables. */
123
124typedef struct {
125 /* This array gives the coefficient quantizers in natural array order
126 * (not the zigzag order in which they are stored in a JPEG DQT marker).
127 * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
128 */
129 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */
130 /* This field is used only during compression. It's initialized FALSE when
131 * the table is created, and set TRUE when it's been output to the file.
132 * You could suppress output of a table by setting this to TRUE.
133 * (See jpeg_suppress_tables for an example.)
134 */
135 boolean sent_table; /* TRUE when table has been output */
136} JQUANT_TBL;
137
138
139/* Huffman coding tables. */
140
141typedef struct {
142 /* These two fields directly represent the contents of a JPEG DHT marker */
143 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */
144 /* length k bits; bits[0] is unused */
145 UINT8 huffval[256]; /* The symbols, in order of incr code length */
146 /* This field is used only during compression. It's initialized FALSE when
147 * the table is created, and set TRUE when it's been output to the file.
148 * You could suppress output of a table by setting this to TRUE.
149 * (See jpeg_suppress_tables for an example.)
150 */
151 boolean sent_table; /* TRUE when table has been output */
152} JHUFF_TBL;
153
154
155/* Basic info about one component (color channel). */
156
157typedef struct {
158 /* These values are fixed over the whole image. */
159 /* For compression, they must be supplied by parameter setup; */
160 /* for decompression, they are read from the SOF marker. */
161 int component_id; /* identifier for this component (0..255) */
162 int component_index; /* its index in SOF or cinfo->comp_info[] */
163 int h_samp_factor; /* horizontal sampling factor (1..4) */
164 int v_samp_factor; /* vertical sampling factor (1..4) */
165 int quant_tbl_no; /* quantization table selector (0..3) */
166 /* These values may vary between scans. */
167 /* For compression, they must be supplied by parameter setup; */
168 /* for decompression, they are read from the SOS marker. */
169 /* The decompressor output side may not use these variables. */
170 int dc_tbl_no; /* DC entropy table selector (0..3) */
171 int ac_tbl_no; /* AC entropy table selector (0..3) */
172
173 /* Remaining fields should be treated as private by applications. */
174
175 /* These values are computed during compression or decompression startup: */
176 /* Component's size in data units.
177 * In lossy mode, any dummy blocks added to complete an MCU are not counted;
178 * therefore these values do not depend on whether a scan is interleaved or
179 * not. In lossless mode, these are always equal to the image width and
180 * height.
181 */
182 JDIMENSION width_in_blocks;
183 JDIMENSION height_in_blocks;
184 /* Size of a data unit in samples. Always DCTSIZE for lossy compression.
185 * For lossy decompression this is the size of the output from one DCT block,
186 * reflecting any scaling we choose to apply during the IDCT step.
187 * Values from 1 to 16 are supported. Note that different components may
188 * receive different IDCT scalings. In lossless mode, this is always equal
189 * to 1.
190 */
191#if JPEG_LIB_VERSION >= 70
192 int DCT_h_scaled_size;
193 int DCT_v_scaled_size;
194#else
195 int DCT_scaled_size;
196#endif
197 /* The downsampled dimensions are the component's actual, unpadded number
198 * of samples at the main buffer (preprocessing/compression interface), thus
199 * downsampled_width = ceil(image_width * Hi/Hmax)
200 * and similarly for height. For lossy decompression, IDCT scaling is
201 * included, so
202 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]scaled_size/DCTSIZE)
203 * In lossless mode, these are always equal to the image width and height.
204 */
205 JDIMENSION downsampled_width; /* actual width in samples */
206 JDIMENSION downsampled_height; /* actual height in samples */
207 /* This flag is used only for decompression. In cases where some of the
208 * components will be ignored (eg grayscale output from YCbCr image),
209 * we can skip most computations for the unused components.
210 */
211 boolean component_needed; /* do we need the value of this component? */
212
213 /* These values are computed before starting a scan of the component. */
214 /* The decompressor output side may not use these variables. */
215 int MCU_width; /* number of data units per MCU, horizontally */
216 int MCU_height; /* number of data units per MCU, vertically */
217 int MCU_blocks; /* MCU_width * MCU_height */
218 int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_[h_]scaled_size */
219 int last_col_width; /* # of non-dummy data units across in last MCU */
220 int last_row_height; /* # of non-dummy data units down in last MCU */
221
222 /* Saved quantization table for component; NULL if none yet saved.
223 * See jdinput.c comments about the need for this information.
224 * This field is currently used only for decompression.
225 */
226 JQUANT_TBL *quant_table;
227
228 /* Private per-component storage for DCT or IDCT subsystem. */
229 void *dct_table;
230} jpeg_component_info;
231
232
233/* The script for encoding a multiple-scan file is an array of these: */
234
235typedef struct {
236 int comps_in_scan; /* number of components encoded in this scan */
237 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
238 int Ss, Se; /* progressive JPEG spectral selection parms
239 (Ss is the predictor selection value in
240 lossless mode) */
241 int Ah, Al; /* progressive JPEG successive approx. parms
242 (Al is the point transform value in lossless
243 mode) */
244} jpeg_scan_info;
245
246/* The decompressor can save APPn and COM markers in a list of these: */
247
248typedef struct jpeg_marker_struct *jpeg_saved_marker_ptr;
249
250struct jpeg_marker_struct {
251 jpeg_saved_marker_ptr next; /* next in list, or NULL */
252 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */
253 unsigned int original_length; /* # bytes of data in the file */
254 unsigned int data_length; /* # bytes of data saved at data[] */
255 JOCTET *data; /* the data contained in the marker */
256 /* the marker length word is not counted in data_length or original_length */
257};
258
259/* Known color spaces. */
260
261#define JCS_EXTENSIONS 1
262#define JCS_ALPHA_EXTENSIONS 1
263
264typedef enum {
265 JCS_UNKNOWN, /* error/unspecified */
266 JCS_GRAYSCALE, /* monochrome */
267 JCS_RGB, /* red/green/blue as specified by the RGB_RED,
268 RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros */
269 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */
270 JCS_CMYK, /* C/M/Y/K */
271 JCS_YCCK, /* Y/Cb/Cr/K */
272 JCS_EXT_RGB, /* red/green/blue */
273 JCS_EXT_RGBX, /* red/green/blue/x */
274 JCS_EXT_BGR, /* blue/green/red */
275 JCS_EXT_BGRX, /* blue/green/red/x */
276 JCS_EXT_XBGR, /* x/blue/green/red */
277 JCS_EXT_XRGB, /* x/red/green/blue */
278 /* When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX, JCS_EXT_XBGR,
279 or JCS_EXT_XRGB during decompression, the X byte is undefined, and in
280 order to ensure the best performance, libjpeg-turbo can set that byte to
281 whatever value it wishes. Use the following colorspace constants to
282 ensure that the X byte is set to 0xFF, so that it can be interpreted as an
283 opaque alpha channel. */
284 JCS_EXT_RGBA, /* red/green/blue/alpha */
285 JCS_EXT_BGRA, /* blue/green/red/alpha */
286 JCS_EXT_ABGR, /* alpha/blue/green/red */
287 JCS_EXT_ARGB, /* alpha/red/green/blue */
288 JCS_RGB565 /* 5-bit red/6-bit green/5-bit blue
289 [decompression only] */
290} J_COLOR_SPACE;
291
292/* DCT/IDCT algorithm options. */
293
294typedef enum {
295 JDCT_ISLOW, /* accurate integer method */
296 JDCT_IFAST, /* less accurate integer method [legacy feature] */
297 JDCT_FLOAT /* floating-point method [legacy feature] */
298} J_DCT_METHOD;
299
300#ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
301#define JDCT_DEFAULT JDCT_ISLOW
302#endif
303#ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
304#define JDCT_FASTEST JDCT_IFAST
305#endif
306
307/* Dithering options for decompression. */
308
309typedef enum {
310 JDITHER_NONE, /* no dithering */
311 JDITHER_ORDERED, /* simple ordered dither */
312 JDITHER_FS /* Floyd-Steinberg error diffusion dither */
313} J_DITHER_MODE;
314
315
316/* Common fields between JPEG compression and decompression master structs. */
317
318#define jpeg_common_fields \
319 struct jpeg_error_mgr *err; /* Error handler module */ \
320 struct jpeg_memory_mgr *mem; /* Memory manager module */ \
321 struct jpeg_progress_mgr *progress; /* Progress monitor, or NULL if none */ \
322 void *client_data; /* Available for use by application */ \
323 boolean is_decompressor; /* So common code can tell which is which */ \
324 int global_state /* For checking call sequence validity */
325
326/* Routines that are to be used by both halves of the library are declared
327 * to receive a pointer to this structure. There are no actual instances of
328 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
329 */
330struct jpeg_common_struct {
331 jpeg_common_fields; /* Fields common to both master struct types */
332 /* Additional fields follow in an actual jpeg_compress_struct or
333 * jpeg_decompress_struct. All three structs must agree on these
334 * initial fields! (This would be a lot cleaner in C++.)
335 */
336};
337
338typedef struct jpeg_common_struct *j_common_ptr;
339typedef struct jpeg_compress_struct *j_compress_ptr;
340typedef struct jpeg_decompress_struct *j_decompress_ptr;
341
342
343/* Master record for a compression instance */
344
345struct jpeg_compress_struct {
346 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */
347
348 /* Destination for compressed data */
349 struct jpeg_destination_mgr *dest;
350
351 /* Description of source image --- these fields must be filled in by
352 * outer application before starting compression. in_color_space must
353 * be correct before you can even call jpeg_set_defaults().
354 */
355
356 JDIMENSION image_width; /* input image width */
357 JDIMENSION image_height; /* input image height */
358 int input_components; /* # of color components in input image */
359 J_COLOR_SPACE in_color_space; /* colorspace of input image */
360
361 double input_gamma; /* image gamma of input image */
362
363 /* Compression parameters --- these fields must be set before calling
364 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
365 * initialize everything to reasonable defaults, then changing anything
366 * the application specifically wants to change. That way you won't get
367 * burnt when new parameters are added. Also note that there are several
368 * helper routines to simplify changing parameters.
369 */
370
371#if JPEG_LIB_VERSION >= 70
372 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
373
374 JDIMENSION jpeg_width; /* scaled JPEG image width */
375 JDIMENSION jpeg_height; /* scaled JPEG image height */
376 /* Dimensions of actual JPEG image that will be written to file,
377 * derived from input dimensions by scaling factors above.
378 * These fields are computed by jpeg_start_compress().
379 * You can also use jpeg_calc_jpeg_dimensions() to determine these values
380 * in advance of calling jpeg_start_compress().
381 */
382#endif
383
384 int data_precision; /* bits of precision in image data */
385
386 int num_components; /* # of color components in JPEG image */
387 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
388
389 jpeg_component_info *comp_info;
390 /* comp_info[i] describes component that appears i'th in SOF */
391
392 JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
393#if JPEG_LIB_VERSION >= 70
394 int q_scale_factor[NUM_QUANT_TBLS];
395#endif
396 /* ptrs to coefficient quantization tables, or NULL if not defined,
397 * and corresponding scale factors (percentage, initialized 100).
398 */
399
400 JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
401 JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
402 /* ptrs to Huffman coding tables, or NULL if not defined */
403
404 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
405 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
406 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
407
408 int num_scans; /* # of entries in scan_info array */
409 const jpeg_scan_info *scan_info; /* script for multi-scan file, or NULL */
410 /* The default value of scan_info is NULL, which causes a single-scan
411 * sequential JPEG file to be emitted. To create a multi-scan file,
412 * set num_scans and scan_info to point to an array of scan definitions.
413 */
414
415 boolean raw_data_in; /* TRUE=caller supplies downsampled data */
416 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
417 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */
418 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
419#if JPEG_LIB_VERSION >= 70
420 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
421#endif
422 int smoothing_factor; /* 1..100, or 0 for no input smoothing */
423 J_DCT_METHOD dct_method; /* DCT algorithm selector */
424
425 /* The restart interval can be specified in absolute MCUs by setting
426 * restart_interval, or in MCU rows by setting restart_in_rows
427 * (in which case the correct restart_interval will be figured
428 * for each scan).
429 */
430 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
431 int restart_in_rows; /* if > 0, MCU rows per restart interval */
432
433 /* Parameters controlling emission of special markers. */
434
435 boolean write_JFIF_header; /* should a JFIF marker be written? */
436 UINT8 JFIF_major_version; /* What to write for the JFIF version number */
437 UINT8 JFIF_minor_version;
438 /* These three values are not used by the JPEG code, merely copied */
439 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
440 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
441 /* ratio is defined by X_density/Y_density even when density_unit=0. */
442 UINT8 density_unit; /* JFIF code for pixel size units */
443 UINT16 X_density; /* Horizontal pixel density */
444 UINT16 Y_density; /* Vertical pixel density */
445 boolean write_Adobe_marker; /* should an Adobe marker be written? */
446
447 /* State variable: index of next scanline to be written to
448 * jpeg_write_scanlines(). Application may use this to control its
449 * processing loop, e.g., "while (next_scanline < image_height)".
450 */
451
452 JDIMENSION next_scanline; /* 0 .. image_height-1 */
453
454 /* Remaining fields are known throughout compressor, but generally
455 * should not be touched by a surrounding application.
456 */
457
458 /*
459 * These fields are computed during compression startup
460 */
461 boolean progressive_mode; /* TRUE if scan script uses progressive mode */
462 int max_h_samp_factor; /* largest h_samp_factor */
463 int max_v_samp_factor; /* largest v_samp_factor */
464
465#if JPEG_LIB_VERSION >= 70
466 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
467 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
468#endif
469
470 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coefficient or
471 difference controller */
472 /* The coefficient or difference controller receives data in units of MCU
473 * rows as defined for fully interleaved scans (whether the JPEG file is
474 * interleaved or not). In lossy mode, there are v_samp_factor * DCTSIZE
475 * sample rows of each component in an "iMCU" (interleaved MCU) row. In
476 * lossless mode, total_iMCU_rows is always equal to the image height.
477 */
478
479 /*
480 * These fields are valid during any one scan.
481 * They describe the components and MCUs actually appearing in the scan.
482 */
483 int comps_in_scan; /* # of JPEG components in this scan */
484 jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
485 /* *cur_comp_info[i] describes component that appears i'th in SOS */
486
487 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
488 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
489
490 int blocks_in_MCU; /* # of data units per MCU */
491 int MCU_membership[C_MAX_BLOCKS_IN_MCU];
492 /* MCU_membership[i] is index in cur_comp_info of component owning */
493 /* i'th data unit in an MCU */
494
495 int Ss, Se, Ah, Al; /* progressive/lossless JPEG parameters for
496 scan */
497
498#if JPEG_LIB_VERSION >= 80
499 int block_size; /* the basic DCT block size: 1..16 */
500 const int *natural_order; /* natural-order position array */
501 int lim_Se; /* min( Se, DCTSIZE2-1 ) */
502#endif
503
504 /*
505 * Links to compression subobjects (methods and private variables of modules)
506 */
507 struct jpeg_comp_master *master;
508 struct jpeg_c_main_controller *main;
509 struct jpeg_c_prep_controller *prep;
510 struct jpeg_c_coef_controller *coef;
511 struct jpeg_marker_writer *marker;
512 struct jpeg_color_converter *cconvert;
513 struct jpeg_downsampler *downsample;
514 struct jpeg_forward_dct *fdct;
515 struct jpeg_entropy_encoder *entropy;
516 jpeg_scan_info *script_space; /* workspace for jpeg_simple_progression */
517 int script_space_size;
518};
519
520
521/* Master record for a decompression instance */
522
523struct jpeg_decompress_struct {
524 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
525
526 /* Source of compressed data */
527 struct jpeg_source_mgr *src;
528
529 /* Basic description of image --- filled in by jpeg_read_header(). */
530 /* Application may inspect these values to decide how to process image. */
531
532 JDIMENSION image_width; /* nominal image width (from SOF marker) */
533 JDIMENSION image_height; /* nominal image height */
534 int num_components; /* # of color components in JPEG image */
535 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
536
537 /* Decompression processing parameters --- these fields must be set before
538 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
539 * them to default values.
540 */
541
542 J_COLOR_SPACE out_color_space; /* colorspace for output */
543
544 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
545
546 double output_gamma; /* image gamma wanted in output */
547
548 boolean buffered_image; /* TRUE=multiple output passes */
549 boolean raw_data_out; /* TRUE=downsampled data wanted */
550
551 J_DCT_METHOD dct_method; /* IDCT algorithm selector */
552 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
553 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
554
555 boolean quantize_colors; /* TRUE=colormapped output wanted */
556 /* the following are ignored if not quantize_colors: */
557 J_DITHER_MODE dither_mode; /* type of color dithering to use */
558 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
559 int desired_number_of_colors; /* max # colors to use in created colormap */
560 /* these are significant only in buffered-image mode: */
561 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
562 boolean enable_external_quant;/* enable future use of external colormap */
563 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
564
565 /* Description of actual output image that will be returned to application.
566 * These fields are computed by jpeg_start_decompress().
567 * You can also use jpeg_calc_output_dimensions() to determine these values
568 * in advance of calling jpeg_start_decompress().
569 */
570
571 JDIMENSION output_width; /* scaled image width */
572 JDIMENSION output_height; /* scaled image height */
573 int out_color_components; /* # of color components in out_color_space */
574 int output_components; /* # of color components returned */
575 /* output_components is 1 (a colormap index) when quantizing colors;
576 * otherwise it equals out_color_components.
577 */
578 int rec_outbuf_height; /* min recommended height of scanline buffer */
579 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
580 * high, space and time will be wasted due to unnecessary data copying.
581 * Usually rec_outbuf_height will be 1 or 2, at most 4.
582 */
583
584 /* When quantizing colors, the output colormap is described by these fields.
585 * The application can supply a colormap by setting colormap non-NULL before
586 * calling jpeg_start_decompress; otherwise a colormap is created during
587 * jpeg_start_decompress or jpeg_start_output.
588 * The map has out_color_components rows and actual_number_of_colors columns.
589 */
590 int actual_number_of_colors; /* number of entries in use */
591 JSAMPARRAY colormap; /* The color map as a 2-D pixel array
592 If data_precision is 12, then this is
593 actually a J12SAMPARRAY, so callers must
594 type-cast it in order to read/write 12-bit
595 samples from/to the array. */
596
597 /* State variables: these variables indicate the progress of decompression.
598 * The application may examine these but must not modify them.
599 */
600
601 /* Row index of next scanline to be read from jpeg_read_scanlines().
602 * Application may use this to control its processing loop, e.g.,
603 * "while (output_scanline < output_height)".
604 */
605 JDIMENSION output_scanline; /* 0 .. output_height-1 */
606
607 /* Current input scan number and number of iMCU rows completed in scan.
608 * These indicate the progress of the decompressor input side.
609 */
610 int input_scan_number; /* Number of SOS markers seen so far */
611 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
612
613 /* The "output scan number" is the notional scan being displayed by the
614 * output side. The decompressor will not allow output scan/row number
615 * to get ahead of input scan/row, but it can fall arbitrarily far behind.
616 */
617 int output_scan_number; /* Nominal scan number being displayed */
618 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
619
620 /* Current progression status. coef_bits[c][i] indicates the precision
621 * with which component c's DCT coefficient i (in zigzag order) is known.
622 * It is -1 when no data has yet been received, otherwise it is the point
623 * transform (shift) value for the most recent scan of the coefficient
624 * (thus, 0 at completion of the progression).
625 * This pointer is NULL when reading a non-progressive file.
626 */
627 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
628
629 /* Internal JPEG parameters --- the application usually need not look at
630 * these fields. Note that the decompressor output side may not use
631 * any parameters that can change between scans.
632 */
633
634 /* Quantization and Huffman tables are carried forward across input
635 * datastreams when processing abbreviated JPEG datastreams.
636 */
637
638 JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
639 /* ptrs to coefficient quantization tables, or NULL if not defined */
640
641 JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
642 JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
643 /* ptrs to Huffman coding tables, or NULL if not defined */
644
645 /* These parameters are never carried across datastreams, since they
646 * are given in SOF/SOS markers or defined to be reset by SOI.
647 */
648
649 int data_precision; /* bits of precision in image data */
650
651 jpeg_component_info *comp_info;
652 /* comp_info[i] describes component that appears i'th in SOF */
653
654#if JPEG_LIB_VERSION >= 80
655 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */
656#endif
657 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
658 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
659
660 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
661 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
662 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
663
664 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
665
666 /* These fields record data obtained from optional markers recognized by
667 * the JPEG library.
668 */
669 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
670 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
671 UINT8 JFIF_major_version; /* JFIF version number */
672 UINT8 JFIF_minor_version;
673 UINT8 density_unit; /* JFIF code for pixel size units */
674 UINT16 X_density; /* Horizontal pixel density */
675 UINT16 Y_density; /* Vertical pixel density */
676 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
677 UINT8 Adobe_transform; /* Color transform code from Adobe marker */
678
679 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
680
681 /* Aside from the specific data retained from APPn markers known to the
682 * library, the uninterpreted contents of any or all APPn and COM markers
683 * can be saved in a list for examination by the application.
684 */
685 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
686
687 /* Remaining fields are known throughout decompressor, but generally
688 * should not be touched by a surrounding application.
689 */
690
691 /*
692 * These fields are computed during decompression startup
693 */
694 int max_h_samp_factor; /* largest h_samp_factor */
695 int max_v_samp_factor; /* largest v_samp_factor */
696
697#if JPEG_LIB_VERSION >= 70
698 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
699 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
700#else
701 int min_DCT_scaled_size; /* smallest DCT_scaled_size of any component */
702#endif
703
704 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
705 /* The coefficient or difference controller's input and output progress is
706 * measured in units of "iMCU" (interleaved MCU) rows. These are the same as
707 * MCU rows in fully interleaved JPEG scans, but are used whether the scan is
708 * interleaved or not. In lossy mode, we define an iMCU row as v_samp_factor
709 * DCT block rows of each component. Therefore, the IDCT output contains
710 * v_samp_factor*DCT_[v_]scaled_size sample rows of a component per iMCU row.
711 * In lossless mode, total_iMCU_rows is always equal to the image height.
712 */
713
714 JSAMPLE *sample_range_limit; /* table for fast range-limiting
715 If data_precision is 9 to 12, then this is
716 actually a J12SAMPLE pointer, and if
717 data_precision is 13 to 16, then this is
718 actually a J16SAMPLE pointer, so callers
719 must type-cast it in order to read samples
720 from the array. */
721
722 /*
723 * These fields are valid during any one scan.
724 * They describe the components and MCUs actually appearing in the scan.
725 * Note that the decompressor output side must not use these fields.
726 */
727 int comps_in_scan; /* # of JPEG components in this scan */
728 jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
729 /* *cur_comp_info[i] describes component that appears i'th in SOS */
730
731 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
732 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
733
734 int blocks_in_MCU; /* # of data units per MCU */
735 int MCU_membership[D_MAX_BLOCKS_IN_MCU];
736 /* MCU_membership[i] is index in cur_comp_info of component owning */
737 /* i'th data unit in an MCU */
738
739 int Ss, Se, Ah, Al; /* progressive/lossless JPEG parameters for
740 scan */
741
742#if JPEG_LIB_VERSION >= 80
743 /* These fields are derived from Se of first SOS marker.
744 */
745 int block_size; /* the basic DCT block size: 1..16 */
746 const int *natural_order; /* natural-order position array for entropy decode */
747 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */
748#endif
749
750 /* This field is shared between entropy decoder and marker parser.
751 * It is either zero or the code of a JPEG marker that has been
752 * read from the data source, but has not yet been processed.
753 */
754 int unread_marker;
755
756 /*
757 * Links to decompression subobjects (methods, private variables of modules)
758 */
759 struct jpeg_decomp_master *master;
760 struct jpeg_d_main_controller *main;
761 struct jpeg_d_coef_controller *coef;
762 struct jpeg_d_post_controller *post;
763 struct jpeg_input_controller *inputctl;
764 struct jpeg_marker_reader *marker;
765 struct jpeg_entropy_decoder *entropy;
766 struct jpeg_inverse_dct *idct;
767 struct jpeg_upsampler *upsample;
768 struct jpeg_color_deconverter *cconvert;
769 struct jpeg_color_quantizer *cquantize;
770};
771
772
773/* "Object" declarations for JPEG modules that may be supplied or called
774 * directly by the surrounding application.
775 * As with all objects in the JPEG library, these structs only define the
776 * publicly visible methods and state variables of a module. Additional
777 * private fields may exist after the public ones.
778 */
779
780
781/* Error handler object */
782
783struct jpeg_error_mgr {
784 /* Error exit handler: does not return to caller */
785 void (*error_exit) (j_common_ptr cinfo);
786 /* Conditionally emit a trace or warning message */
787 void (*emit_message) (j_common_ptr cinfo, int msg_level);
788 /* Routine that actually outputs a trace or error message */
789 void (*output_message) (j_common_ptr cinfo);
790 /* Format a message string for the most recent JPEG error or message */
791 void (*format_message) (j_common_ptr cinfo, char *buffer);
792#define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
793 /* Reset error state variables at start of a new image */
794 void (*reset_error_mgr) (j_common_ptr cinfo);
795
796 /* The message ID code and any parameters are saved here.
797 * A message can have one string parameter or up to 8 int parameters.
798 */
799 int msg_code;
800#define JMSG_STR_PARM_MAX 80
801 union {
802 int i[8];
803 char s[JMSG_STR_PARM_MAX];
804 } msg_parm;
805
806 /* Standard state variables for error facility */
807
808 int trace_level; /* max msg_level that will be displayed */
809
810 /* For recoverable corrupt-data errors, we emit a warning message,
811 * but keep going unless emit_message chooses to abort. emit_message
812 * should count warnings in num_warnings. The surrounding application
813 * can check for bad data by seeing if num_warnings is nonzero at the
814 * end of processing.
815 */
816 long num_warnings; /* number of corrupt-data warnings */
817
818 /* These fields point to the table(s) of error message strings.
819 * An application can change the table pointer to switch to a different
820 * message list (typically, to change the language in which errors are
821 * reported). Some applications may wish to add additional error codes
822 * that will be handled by the JPEG library error mechanism; the second
823 * table pointer is used for this purpose.
824 *
825 * First table includes all errors generated by JPEG library itself.
826 * Error code 0 is reserved for a "no such error string" message.
827 */
828 const char * const *jpeg_message_table; /* Library errors */
829 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
830 /* Second table can be added by application (see cjpeg/djpeg for example).
831 * It contains strings numbered first_addon_message..last_addon_message.
832 */
833 const char * const *addon_message_table; /* Non-library errors */
834 int first_addon_message; /* code for first string in addon table */
835 int last_addon_message; /* code for last string in addon table */
836};
837
838
839/* Progress monitor object */
840
841struct jpeg_progress_mgr {
842 void (*progress_monitor) (j_common_ptr cinfo);
843
844 long pass_counter; /* work units completed in this pass */
845 long pass_limit; /* total number of work units in this pass */
846 int completed_passes; /* passes completed so far */
847 int total_passes; /* total number of passes expected */
848};
849
850
851/* Data destination object for compression */
852
853struct jpeg_destination_mgr {
854 JOCTET *next_output_byte; /* => next byte to write in buffer */
855 size_t free_in_buffer; /* # of byte spaces remaining in buffer */
856
857 void (*init_destination) (j_compress_ptr cinfo);
858 boolean (*empty_output_buffer) (j_compress_ptr cinfo);
859 void (*term_destination) (j_compress_ptr cinfo);
860};
861
862
863/* Data source object for decompression */
864
865struct jpeg_source_mgr {
866 const JOCTET *next_input_byte; /* => next byte to read from buffer */
867 size_t bytes_in_buffer; /* # of bytes remaining in buffer */
868
869 void (*init_source) (j_decompress_ptr cinfo);
870 boolean (*fill_input_buffer) (j_decompress_ptr cinfo);
871 void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes);
872 boolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired);
873 void (*term_source) (j_decompress_ptr cinfo);
874};
875
876
877/* Memory manager object.
878 * Allocates "small" objects (a few K total), "large" objects (tens of K),
879 * and "really big" objects (virtual arrays with backing store if needed).
880 * The memory manager does not allow individual objects to be freed; rather,
881 * each created object is assigned to a pool, and whole pools can be freed
882 * at once. This is faster and more convenient than remembering exactly what
883 * to free, especially where malloc()/free() are not too speedy.
884 * NB: alloc routines never return NULL. They exit to error_exit if not
885 * successful.
886 */
887
888#define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
889#define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
890#define JPOOL_NUMPOOLS 2
891
892typedef struct jvirt_sarray_control *jvirt_sarray_ptr;
893typedef struct jvirt_barray_control *jvirt_barray_ptr;
894
895
896struct jpeg_memory_mgr {
897 /* Method pointers */
898 void *(*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject);
899 void *(*alloc_large) (j_common_ptr cinfo, int pool_id,
900 size_t sizeofobject);
901 /* If cinfo->data_precision is 12 or 16, then this method and the
902 * access_virt_sarray method actually return a J12SAMPARRAY or a
903 * J16SAMPARRAY, so callers must type-cast the return value in order to
904 * read/write 12-bit or 16-bit samples from/to the array.
905 */
906 JSAMPARRAY (*alloc_sarray) (j_common_ptr cinfo, int pool_id,
907 JDIMENSION samplesperrow, JDIMENSION numrows);
908 JBLOCKARRAY (*alloc_barray) (j_common_ptr cinfo, int pool_id,
909 JDIMENSION blocksperrow, JDIMENSION numrows);
910 jvirt_sarray_ptr (*request_virt_sarray) (j_common_ptr cinfo, int pool_id,
911 boolean pre_zero,
912 JDIMENSION samplesperrow,
913 JDIMENSION numrows,
914 JDIMENSION maxaccess);
915 jvirt_barray_ptr (*request_virt_barray) (j_common_ptr cinfo, int pool_id,
916 boolean pre_zero,
917 JDIMENSION blocksperrow,
918 JDIMENSION numrows,
919 JDIMENSION maxaccess);
920 void (*realize_virt_arrays) (j_common_ptr cinfo);
921 JSAMPARRAY (*access_virt_sarray) (j_common_ptr cinfo, jvirt_sarray_ptr ptr,
922 JDIMENSION start_row, JDIMENSION num_rows,
923 boolean writable);
924 JBLOCKARRAY (*access_virt_barray) (j_common_ptr cinfo, jvirt_barray_ptr ptr,
925 JDIMENSION start_row, JDIMENSION num_rows,
926 boolean writable);
927 void (*free_pool) (j_common_ptr cinfo, int pool_id);
928 void (*self_destruct) (j_common_ptr cinfo);
929
930 /* Limit on memory allocation for this JPEG object. (Note that this is
931 * merely advisory, not a guaranteed maximum; it only affects the space
932 * used for virtual-array buffers.) May be changed by outer application
933 * after creating the JPEG object.
934 */
935 long max_memory_to_use;
936
937 /* Maximum allocation request accepted by alloc_large. */
938 long max_alloc_chunk;
939};
940
941
942/* Routine signature for application-supplied marker processing methods.
943 * Need not pass marker code since it is stored in cinfo->unread_marker.
944 */
945typedef boolean (*jpeg_marker_parser_method) (j_decompress_ptr cinfo);
946
947
948/* Originally, this macro was used as a way of defining function prototypes
949 * for both modern compilers as well as older compilers that did not support
950 * prototype parameters. libjpeg-turbo has never supported these older,
951 * non-ANSI compilers, but the macro is still included because there is some
952 * software out there that uses it.
953 */
954
955#define JPP(arglist) arglist
956
957
958/* Default error-management setup */
959EXTERN(struct jpeg_error_mgr *) jpeg_std_error(struct jpeg_error_mgr *err);
960
961/* Initialization of JPEG compression objects.
962 * jpeg_create_compress() and jpeg_create_decompress() are the exported
963 * names that applications should call. These expand to calls on
964 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
965 * passed for version mismatch checking.
966 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
967 */
968#define jpeg_create_compress(cinfo) \
969 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
970 (size_t)sizeof(struct jpeg_compress_struct))
971#define jpeg_create_decompress(cinfo) \
972 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
973 (size_t)sizeof(struct jpeg_decompress_struct))
974EXTERN(void) jpeg_CreateCompress(j_compress_ptr cinfo, int version,
975 size_t structsize);
976EXTERN(void) jpeg_CreateDecompress(j_decompress_ptr cinfo, int version,
977 size_t structsize);
978/* Destruction of JPEG compression objects */
979EXTERN(void) jpeg_destroy_compress(j_compress_ptr cinfo);
980EXTERN(void) jpeg_destroy_decompress(j_decompress_ptr cinfo);
981
982/* Standard data source and destination managers: stdio streams. */
983/* Caller is responsible for opening the file before and closing after. */
984EXTERN(void) jpeg_stdio_dest(j_compress_ptr cinfo, FILE *outfile);
985EXTERN(void) jpeg_stdio_src(j_decompress_ptr cinfo, FILE *infile);
986
987/* Data source and destination managers: memory buffers. */
988EXTERN(void) jpeg_mem_dest(j_compress_ptr cinfo, unsigned char **outbuffer,
989 unsigned long *outsize);
990EXTERN(void) jpeg_mem_src(j_decompress_ptr cinfo,
991 const unsigned char *inbuffer, unsigned long insize);
992
993/* Default parameter setup for compression */
994EXTERN(void) jpeg_set_defaults(j_compress_ptr cinfo);
995/* Compression parameter setup aids */
996EXTERN(void) jpeg_set_colorspace(j_compress_ptr cinfo,
997 J_COLOR_SPACE colorspace);
998EXTERN(void) jpeg_default_colorspace(j_compress_ptr cinfo);
999EXTERN(void) jpeg_set_quality(j_compress_ptr cinfo, int quality,
1000 boolean force_baseline);
1001EXTERN(void) jpeg_set_linear_quality(j_compress_ptr cinfo, int scale_factor,
1002 boolean force_baseline);
1003#if JPEG_LIB_VERSION >= 70
1004EXTERN(void) jpeg_default_qtables(j_compress_ptr cinfo,
1005 boolean force_baseline);
1006#endif
1007EXTERN(void) jpeg_add_quant_table(j_compress_ptr cinfo, int which_tbl,
1008 const unsigned int *basic_table,
1009 int scale_factor, boolean force_baseline);
1010EXTERN(int) jpeg_quality_scaling(int quality);
1011EXTERN(void) jpeg_enable_lossless(j_compress_ptr cinfo,
1012 int predictor_selection_value,
1013 int point_transform);
1014EXTERN(void) jpeg_simple_progression(j_compress_ptr cinfo);
1015EXTERN(void) jpeg_suppress_tables(j_compress_ptr cinfo, boolean suppress);
1016EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table(j_common_ptr cinfo);
1017EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table(j_common_ptr cinfo);
1018
1019/* Main entry points for compression */
1020EXTERN(void) jpeg_start_compress(j_compress_ptr cinfo,
1021 boolean write_all_tables);
1022EXTERN(JDIMENSION) jpeg_write_scanlines(j_compress_ptr cinfo,
1023 JSAMPARRAY scanlines,
1024 JDIMENSION num_lines);
1025EXTERN(JDIMENSION) jpeg12_write_scanlines(j_compress_ptr cinfo,
1026 J12SAMPARRAY scanlines,
1027 JDIMENSION num_lines);
1028EXTERN(JDIMENSION) jpeg16_write_scanlines(j_compress_ptr cinfo,
1029 J16SAMPARRAY scanlines,
1030 JDIMENSION num_lines);
1031EXTERN(void) jpeg_finish_compress(j_compress_ptr cinfo);
1032
1033#if JPEG_LIB_VERSION >= 70
1034/* Precalculate JPEG dimensions for current compression parameters. */
1035EXTERN(void) jpeg_calc_jpeg_dimensions(j_compress_ptr cinfo);
1036#endif
1037
1038/* Replaces jpeg_write_scanlines when writing raw downsampled data. */
1039EXTERN(JDIMENSION) jpeg_write_raw_data(j_compress_ptr cinfo, JSAMPIMAGE data,
1040 JDIMENSION num_lines);
1041EXTERN(JDIMENSION) jpeg12_write_raw_data(j_compress_ptr cinfo,
1042 J12SAMPIMAGE data,
1043 JDIMENSION num_lines);
1044
1045/* Write a special marker. See libjpeg.txt concerning safe usage. */
1046EXTERN(void) jpeg_write_marker(j_compress_ptr cinfo, int marker,
1047 const JOCTET *dataptr, unsigned int datalen);
1048/* Same, but piecemeal. */
1049EXTERN(void) jpeg_write_m_header(j_compress_ptr cinfo, int marker,
1050 unsigned int datalen);
1051EXTERN(void) jpeg_write_m_byte(j_compress_ptr cinfo, int val);
1052
1053/* Alternate compression function: just write an abbreviated table file */
1054EXTERN(void) jpeg_write_tables(j_compress_ptr cinfo);
1055
1056/* Write ICC profile. See libjpeg.txt for usage information. */
1057EXTERN(void) jpeg_write_icc_profile(j_compress_ptr cinfo,
1058 const JOCTET *icc_data_ptr,
1059 unsigned int icc_data_len);
1060
1061
1062/* Decompression startup: read start of JPEG datastream to see what's there */
1063EXTERN(int) jpeg_read_header(j_decompress_ptr cinfo, boolean require_image);
1064/* Return value is one of: */
1065#define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
1066#define JPEG_HEADER_OK 1 /* Found valid image datastream */
1067#define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
1068/* If you pass require_image = TRUE (normal case), you need not check for
1069 * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
1070 * JPEG_SUSPENDED is only possible if you use a data source module that can
1071 * give a suspension return (the stdio source module doesn't).
1072 */
1073
1074/* Main entry points for decompression */
1075EXTERN(boolean) jpeg_start_decompress(j_decompress_ptr cinfo);
1076EXTERN(JDIMENSION) jpeg_read_scanlines(j_decompress_ptr cinfo,
1077 JSAMPARRAY scanlines,
1078 JDIMENSION max_lines);
1079EXTERN(JDIMENSION) jpeg12_read_scanlines(j_decompress_ptr cinfo,
1080 J12SAMPARRAY scanlines,
1081 JDIMENSION max_lines);
1082EXTERN(JDIMENSION) jpeg16_read_scanlines(j_decompress_ptr cinfo,
1083 J16SAMPARRAY scanlines,
1084 JDIMENSION max_lines);
1085EXTERN(JDIMENSION) jpeg_skip_scanlines(j_decompress_ptr cinfo,
1086 JDIMENSION num_lines);
1087EXTERN(JDIMENSION) jpeg12_skip_scanlines(j_decompress_ptr cinfo,
1088 JDIMENSION num_lines);
1089EXTERN(void) jpeg_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
1090 JDIMENSION *width);
1091EXTERN(void) jpeg12_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
1092 JDIMENSION *width);
1093EXTERN(boolean) jpeg_finish_decompress(j_decompress_ptr cinfo);
1094
1095/* Replaces jpeg_read_scanlines when reading raw downsampled data. */
1096EXTERN(JDIMENSION) jpeg_read_raw_data(j_decompress_ptr cinfo, JSAMPIMAGE data,
1097 JDIMENSION max_lines);
1098EXTERN(JDIMENSION) jpeg12_read_raw_data(j_decompress_ptr cinfo,
1099 J12SAMPIMAGE data,
1100 JDIMENSION max_lines);
1101
1102/* Additional entry points for buffered-image mode. */
1103EXTERN(boolean) jpeg_has_multiple_scans(j_decompress_ptr cinfo);
1104EXTERN(boolean) jpeg_start_output(j_decompress_ptr cinfo, int scan_number);
1105EXTERN(boolean) jpeg_finish_output(j_decompress_ptr cinfo);
1106EXTERN(boolean) jpeg_input_complete(j_decompress_ptr cinfo);
1107EXTERN(void) jpeg_new_colormap(j_decompress_ptr cinfo);
1108EXTERN(int) jpeg_consume_input(j_decompress_ptr cinfo);
1109/* Return value is one of: */
1110/* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
1111#define JPEG_REACHED_SOS 1 /* Reached start of new scan */
1112#define JPEG_REACHED_EOI 2 /* Reached end of image */
1113#define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
1114#define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
1115
1116/* Precalculate output dimensions for current decompression parameters. */
1117#if JPEG_LIB_VERSION >= 80
1118EXTERN(void) jpeg_core_output_dimensions(j_decompress_ptr cinfo);
1119#endif
1120EXTERN(void) jpeg_calc_output_dimensions(j_decompress_ptr cinfo);
1121
1122/* Control saving of COM and APPn markers into marker_list. */
1123EXTERN(void) jpeg_save_markers(j_decompress_ptr cinfo, int marker_code,
1124 unsigned int length_limit);
1125
1126/* Install a special processing method for COM or APPn markers. */
1127EXTERN(void) jpeg_set_marker_processor(j_decompress_ptr cinfo,
1128 int marker_code,
1129 jpeg_marker_parser_method routine);
1130
1131/* Read or write raw DCT coefficients --- useful for lossless transcoding. */
1132EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients(j_decompress_ptr cinfo);
1133EXTERN(void) jpeg_write_coefficients(j_compress_ptr cinfo,
1134 jvirt_barray_ptr *coef_arrays);
1135EXTERN(void) jpeg_copy_critical_parameters(j_decompress_ptr srcinfo,
1136 j_compress_ptr dstinfo);
1137
1138/* If you choose to abort compression or decompression before completing
1139 * jpeg_finish_(de)compress, then you need to clean up to release memory,
1140 * temporary files, etc. You can just call jpeg_destroy_(de)compress
1141 * if you're done with the JPEG object, but if you want to clean it up and
1142 * reuse it, call this:
1143 */
1144EXTERN(void) jpeg_abort_compress(j_compress_ptr cinfo);
1145EXTERN(void) jpeg_abort_decompress(j_decompress_ptr cinfo);
1146
1147/* Generic versions of jpeg_abort and jpeg_destroy that work on either
1148 * flavor of JPEG object. These may be more convenient in some places.
1149 */
1150EXTERN(void) jpeg_abort(j_common_ptr cinfo);
1151EXTERN(void) jpeg_destroy(j_common_ptr cinfo);
1152
1153/* Default restart-marker-resync procedure for use by data source modules */
1154EXTERN(boolean) jpeg_resync_to_restart(j_decompress_ptr cinfo, int desired);
1155
1156/* Read ICC profile. See libjpeg.txt for usage information. */
1157EXTERN(boolean) jpeg_read_icc_profile(j_decompress_ptr cinfo,
1158 JOCTET **icc_data_ptr,
1159 unsigned int *icc_data_len);
1160
1161
1162/* These marker codes are exported since applications and data source modules
1163 * are likely to want to use them.
1164 */
1165
1166#define JPEG_RST0 0xD0 /* RST0 marker code */
1167#define JPEG_EOI 0xD9 /* EOI marker code */
1168#define JPEG_APP0 0xE0 /* APP0 marker code */
1169#define JPEG_COM 0xFE /* COM marker code */
1170
1171
1172/* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1173 * for structure definitions that are never filled in, keep it quiet by
1174 * supplying dummy definitions for the various substructures.
1175 */
1176
1177#ifdef INCOMPLETE_TYPES_BROKEN
1178#ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
1179struct jvirt_sarray_control { long dummy; };
1180struct jvirt_barray_control { long dummy; };
1181struct jpeg_comp_master { long dummy; };
1182struct jpeg_c_main_controller { long dummy; };
1183struct jpeg_c_prep_controller { long dummy; };
1184struct jpeg_c_coef_controller { long dummy; };
1185struct jpeg_marker_writer { long dummy; };
1186struct jpeg_color_converter { long dummy; };
1187struct jpeg_downsampler { long dummy; };
1188struct jpeg_forward_dct { long dummy; };
1189struct jpeg_entropy_encoder { long dummy; };
1190struct jpeg_decomp_master { long dummy; };
1191struct jpeg_d_main_controller { long dummy; };
1192struct jpeg_d_coef_controller { long dummy; };
1193struct jpeg_d_post_controller { long dummy; };
1194struct jpeg_input_controller { long dummy; };
1195struct jpeg_marker_reader { long dummy; };
1196struct jpeg_entropy_decoder { long dummy; };
1197struct jpeg_inverse_dct { long dummy; };
1198struct jpeg_upsampler { long dummy; };
1199struct jpeg_color_deconverter { long dummy; };
1200struct jpeg_color_quantizer { long dummy; };
1201#endif /* JPEG_INTERNALS */
1202#endif /* INCOMPLETE_TYPES_BROKEN */
1203
1204
1205/*
1206 * The JPEG library modules define JPEG_INTERNALS before including this file.
1207 * The internal structure declarations are read only when that is true.
1208 * Applications using the library should not include jpegint.h, but may wish
1209 * to include jerror.h.
1210 */
1211
1212#ifdef JPEG_INTERNALS
1213#include "jpegint.h" /* fetch private declarations */
1214#include "jerror.h" /* fetch error codes too */
1215#endif
1216
1217#ifdef __cplusplus
1218#ifndef DONT_USE_EXTERN_C
1219}
1220#endif
1221#endif
1222
1223#endif /* JPEGLIB_H */
1224