1 | /* |
2 | * reserved comment block |
3 | * DO NOT REMOVE OR ALTER! |
4 | */ |
5 | /* |
6 | * jpeglib.h |
7 | * |
8 | * Copyright (C) 1991-1998, Thomas G. Lane. |
9 | * This file is part of the Independent JPEG Group's software. |
10 | * For conditions of distribution and use, see the accompanying README file. |
11 | * |
12 | * This file defines the application interface for the JPEG library. |
13 | * Most applications using the library need only include this file, |
14 | * and perhaps jerror.h if they want to know the exact error codes. |
15 | */ |
16 | |
17 | #ifndef JPEGLIB_H |
18 | #define JPEGLIB_H |
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_size */ |
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 ; /* 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 restart */ |
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 | size_t max_memory_to_use; |
804 | |
805 | /* Maximum allocation request accepted by alloc_large. */ |
806 | size_t 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 |
860 | #define jpeg_write_m_byte jWrtMByte |
861 | #define jpeg_write_tables jWrtTables |
862 | #define |
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 1 /* Found valid image datastream */ |
971 | #define 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 */ |
1101 | |