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