4 * Copyright (C) 1991-1998, Thomas G. Lane.
5 * Modified 2002-2010 by Guido Vollbeding.
6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file.
9 * This file defines the application interface for the JPEG library.
10 * Most applications using the library need only include this file,
11 * and perhaps jerror.h if they want to know the exact error codes.
18 * First we include the configuration files that record how this
19 * installation of the JPEG library is set up. jconfig.h can be
20 * generated automatically for many systems. jmorecfg.h contains
21 * manual configuration options that most people need not worry about.
24 #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */
25 #include "jconfig.h" /* widely used configuration options */
27 #include "jmorecfg.h" /* seldom changed options */
31 #ifndef DONT_USE_EXTERN_C
36 /* Version IDs for the JPEG library.
37 * Might be useful for tests like "#if JPEG_LIB_VERSION >= 80".
40 #define JPEG_LIB_VERSION 80 /* Compatibility version 8.0 */
41 #define JPEG_LIB_VERSION_MAJOR 8
42 #define JPEG_LIB_VERSION_MINOR 3
45 /* Various constants determining the sizes of things.
46 * All of these are specified by the JPEG standard, so don't change them
47 * if you want to be compatible.
50 #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */
51 #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
52 #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
53 #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
54 #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
55 #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
56 #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
57 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
58 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
59 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
60 * to handle it. We even let you do this from the jconfig.h file. However,
61 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
62 * sometimes emits noncompliant files doesn't mean you should too.
64 #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */
65 #ifndef D_MAX_BLOCKS_IN_MCU
66 #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */
70 /* Data structures for images (arrays of samples and of DCT coefficients).
71 * On 80x86 machines, the image arrays are too big for near pointers,
72 * but the pointer arrays can fit in near memory.
75 typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */
76 typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */
77 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
79 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
80 typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */
81 typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
82 typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
84 typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */
87 /* Types for JPEG compression parameters and working tables. */
90 /* DCT coefficient quantization tables. */
93 /* This array gives the coefficient quantizers in natural array order
94 * (not the zigzag order in which they are stored in a JPEG DQT marker).
95 * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
97 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */
98 /* This field is used only during compression. It's initialized FALSE when
99 * the table is created, and set TRUE when it's been output to the file.
100 * You could suppress output of a table by setting this to TRUE.
101 * (See jpeg_suppress_tables for an example.)
103 boolean sent_table; /* TRUE when table has been output */
107 /* Huffman coding tables. */
110 /* These two fields directly represent the contents of a JPEG DHT marker */
111 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */
112 /* length k bits; bits[0] is unused */
113 UINT8 huffval[256]; /* The symbols, in order of incr code length */
114 /* This field is used only during compression. It's initialized FALSE when
115 * the table is created, and set TRUE when it's been output to the file.
116 * You could suppress output of a table by setting this to TRUE.
117 * (See jpeg_suppress_tables for an example.)
119 boolean sent_table; /* TRUE when table has been output */
123 /* Basic info about one component (color channel). */
126 /* These values are fixed over the whole image. */
127 /* For compression, they must be supplied by parameter setup; */
128 /* for decompression, they are read from the SOF marker. */
129 int component_id; /* identifier for this component (0..255) */
130 int component_index; /* its index in SOF or cinfo->comp_info[] */
131 int h_samp_factor; /* horizontal sampling factor (1..4) */
132 int v_samp_factor; /* vertical sampling factor (1..4) */
133 int quant_tbl_no; /* quantization table selector (0..3) */
134 /* These values may vary between scans. */
135 /* For compression, they must be supplied by parameter setup; */
136 /* for decompression, they are read from the SOS marker. */
137 /* The decompressor output side may not use these variables. */
138 int dc_tbl_no; /* DC entropy table selector (0..3) */
139 int ac_tbl_no; /* AC entropy table selector (0..3) */
141 /* Remaining fields should be treated as private by applications. */
143 /* These values are computed during compression or decompression startup: */
144 /* Component's size in DCT blocks.
145 * Any dummy blocks added to complete an MCU are not counted; therefore
146 * these values do not depend on whether a scan is interleaved or not.
148 JDIMENSION width_in_blocks;
149 JDIMENSION height_in_blocks;
150 /* Size of a DCT block in samples,
151 * reflecting any scaling we choose to apply during the DCT step.
152 * Values from 1 to 16 are supported.
153 * Note that different components may receive different DCT scalings.
155 int DCT_h_scaled_size;
156 int DCT_v_scaled_size;
157 /* The downsampled dimensions are the component's actual, unpadded number
158 * of samples at the main buffer (preprocessing/compression interface);
159 * DCT scaling is included, so
160 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_h_scaled_size/DCTSIZE)
161 * and similarly for height.
163 JDIMENSION downsampled_width; /* actual width in samples */
164 JDIMENSION downsampled_height; /* actual height in samples */
165 /* This flag is used only for decompression. In cases where some of the
166 * components will be ignored (eg grayscale output from YCbCr image),
167 * we can skip most computations for the unused components.
169 boolean component_needed; /* do we need the value of this component? */
171 /* These values are computed before starting a scan of the component. */
172 /* The decompressor output side may not use these variables. */
173 int MCU_width; /* number of blocks per MCU, horizontally */
174 int MCU_height; /* number of blocks per MCU, vertically */
175 int MCU_blocks; /* MCU_width * MCU_height */
176 int MCU_sample_width; /* MCU width in samples: MCU_width * DCT_h_scaled_size */
177 int last_col_width; /* # of non-dummy blocks across in last MCU */
178 int last_row_height; /* # of non-dummy blocks down in last MCU */
180 /* Saved quantization table for component; NULL if none yet saved.
181 * See jdinput.c comments about the need for this information.
182 * This field is currently used only for decompression.
184 JQUANT_TBL * quant_table;
186 /* Private per-component storage for DCT or IDCT subsystem. */
188 } jpeg_component_info;
191 /* The script for encoding a multiple-scan file is an array of these: */
194 int comps_in_scan; /* number of components encoded in this scan */
195 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
196 int Ss, Se; /* progressive JPEG spectral selection parms */
197 int Ah, Al; /* progressive JPEG successive approx. parms */
200 /* The decompressor can save APPn and COM markers in a list of these: */
202 typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr;
204 struct jpeg_marker_struct {
205 jpeg_saved_marker_ptr next; /* next in list, or NULL */
206 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */
207 unsigned int original_length; /* # bytes of data in the file */
208 unsigned int data_length; /* # bytes of data saved at data[] */
209 JOCTET FAR * data; /* the data contained in the marker */
210 /* the marker length word is not counted in data_length or original_length */
213 /* Known color spaces. */
216 JCS_UNKNOWN, /* error/unspecified */
217 JCS_GRAYSCALE, /* monochrome */
218 JCS_RGB, /* red/green/blue */
219 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */
220 JCS_CMYK, /* C/M/Y/K */
221 JCS_YCCK /* Y/Cb/Cr/K */
224 /* DCT/IDCT algorithm options. */
227 JDCT_ISLOW, /* slow but accurate integer algorithm */
228 JDCT_IFAST, /* faster, less accurate integer method */
229 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */
232 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
233 #define JDCT_DEFAULT JDCT_ISLOW
235 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
236 #define JDCT_FASTEST JDCT_IFAST
239 /* Dithering options for decompression. */
242 JDITHER_NONE, /* no dithering */
243 JDITHER_ORDERED, /* simple ordered dither */
244 JDITHER_FS /* Floyd-Steinberg error diffusion dither */
248 /* Common fields between JPEG compression and decompression master structs. */
250 #define jpeg_common_fields \
251 struct jpeg_error_mgr * err; /* Error handler module */\
252 struct jpeg_memory_mgr * mem; /* Memory manager module */\
253 struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
254 void * client_data; /* Available for use by application */\
255 boolean is_decompressor; /* So common code can tell which is which */\
256 int global_state /* For checking call sequence validity */
258 /* Routines that are to be used by both halves of the library are declared
259 * to receive a pointer to this structure. There are no actual instances of
260 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
262 struct jpeg_common_struct {
263 jpeg_common_fields; /* Fields common to both master struct types */
264 /* Additional fields follow in an actual jpeg_compress_struct or
265 * jpeg_decompress_struct. All three structs must agree on these
266 * initial fields! (This would be a lot cleaner in C++.)
270 typedef struct jpeg_common_struct * j_common_ptr;
271 typedef struct jpeg_compress_struct * j_compress_ptr;
272 typedef struct jpeg_decompress_struct * j_decompress_ptr;
275 /* Master record for a compression instance */
277 struct jpeg_compress_struct {
278 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */
280 /* Destination for compressed data */
281 struct jpeg_destination_mgr * dest;
283 /* Description of source image --- these fields must be filled in by
284 * outer application before starting compression. in_color_space must
285 * be correct before you can even call jpeg_set_defaults().
288 JDIMENSION image_width; /* input image width */
289 JDIMENSION image_height; /* input image height */
290 int input_components; /* # of color components in input image */
291 J_COLOR_SPACE in_color_space; /* colorspace of input image */
293 double input_gamma; /* image gamma of input image */
295 /* Compression parameters --- these fields must be set before calling
296 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
297 * initialize everything to reasonable defaults, then changing anything
298 * the application specifically wants to change. That way you won't get
299 * burnt when new parameters are added. Also note that there are several
300 * helper routines to simplify changing parameters.
303 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
305 JDIMENSION jpeg_width; /* scaled JPEG image width */
306 JDIMENSION jpeg_height; /* scaled JPEG image height */
307 /* Dimensions of actual JPEG image that will be written to file,
308 * derived from input dimensions by scaling factors above.
309 * These fields are computed by jpeg_start_compress().
310 * You can also use jpeg_calc_jpeg_dimensions() to determine these values
311 * in advance of calling jpeg_start_compress().
314 int data_precision; /* bits of precision in image data */
316 int num_components; /* # of color components in JPEG image */
317 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
319 jpeg_component_info * comp_info;
320 /* comp_info[i] describes component that appears i'th in SOF */
322 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
323 int q_scale_factor[NUM_QUANT_TBLS];
324 /* ptrs to coefficient quantization tables, or NULL if not defined,
325 * and corresponding scale factors (percentage, initialized 100).
328 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
329 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
330 /* ptrs to Huffman coding tables, or NULL if not defined */
332 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
333 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
334 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
336 int num_scans; /* # of entries in scan_info array */
337 const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */
338 /* The default value of scan_info is NULL, which causes a single-scan
339 * sequential JPEG file to be emitted. To create a multi-scan file,
340 * set num_scans and scan_info to point to an array of scan definitions.
343 boolean raw_data_in; /* TRUE=caller supplies downsampled data */
344 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
345 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */
346 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
347 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
348 int smoothing_factor; /* 1..100, or 0 for no input smoothing */
349 J_DCT_METHOD dct_method; /* DCT algorithm selector */
351 /* The restart interval can be specified in absolute MCUs by setting
352 * restart_interval, or in MCU rows by setting restart_in_rows
353 * (in which case the correct restart_interval will be figured
356 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
357 int restart_in_rows; /* if > 0, MCU rows per restart interval */
359 /* Parameters controlling emission of special markers. */
361 boolean write_JFIF_header; /* should a JFIF marker be written? */
362 UINT8 JFIF_major_version; /* What to write for the JFIF version number */
363 UINT8 JFIF_minor_version;
364 /* These three values are not used by the JPEG code, merely copied */
365 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
366 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
367 /* ratio is defined by X_density/Y_density even when density_unit=0. */
368 UINT8 density_unit; /* JFIF code for pixel size units */
369 UINT16 X_density; /* Horizontal pixel density */
370 UINT16 Y_density; /* Vertical pixel density */
371 boolean write_Adobe_marker; /* should an Adobe marker be written? */
373 /* State variable: index of next scanline to be written to
374 * jpeg_write_scanlines(). Application may use this to control its
375 * processing loop, e.g., "while (next_scanline < image_height)".
378 JDIMENSION next_scanline; /* 0 .. image_height-1 */
380 /* Remaining fields are known throughout compressor, but generally
381 * should not be touched by a surrounding application.
385 * These fields are computed during compression startup
387 boolean progressive_mode; /* TRUE if scan script uses progressive mode */
388 int max_h_samp_factor; /* largest h_samp_factor */
389 int max_v_samp_factor; /* largest v_samp_factor */
391 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
392 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
394 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */
395 /* The coefficient controller receives data in units of MCU rows as defined
396 * for fully interleaved scans (whether the JPEG file is interleaved or not).
397 * There are v_samp_factor * DCTSIZE sample rows of each component in an
398 * "iMCU" (interleaved MCU) row.
402 * These fields are valid during any one scan.
403 * They describe the components and MCUs actually appearing in the scan.
405 int comps_in_scan; /* # of JPEG components in this scan */
406 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
407 /* *cur_comp_info[i] describes component that appears i'th in SOS */
409 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
410 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
412 int blocks_in_MCU; /* # of DCT blocks per MCU */
413 int MCU_membership[C_MAX_BLOCKS_IN_MCU];
414 /* MCU_membership[i] is index in cur_comp_info of component owning */
415 /* i'th block in an MCU */
417 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
419 int block_size; /* the basic DCT block size: 1..16 */
420 const int * natural_order; /* natural-order position array */
421 int lim_Se; /* min( Se, DCTSIZE2-1 ) */
424 * Links to compression subobjects (methods and private variables of modules)
426 struct jpeg_comp_master * master;
427 struct jpeg_c_main_controller * main;
428 struct jpeg_c_prep_controller * prep;
429 struct jpeg_c_coef_controller * coef;
430 struct jpeg_marker_writer * marker;
431 struct jpeg_color_converter * cconvert;
432 struct jpeg_downsampler * downsample;
433 struct jpeg_forward_dct * fdct;
434 struct jpeg_entropy_encoder * entropy;
435 jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */
436 int script_space_size;
440 /* Master record for a decompression instance */
442 struct jpeg_decompress_struct {
443 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
445 /* Source of compressed data */
446 struct jpeg_source_mgr * src;
448 /* Basic description of image --- filled in by jpeg_read_header(). */
449 /* Application may inspect these values to decide how to process image. */
451 JDIMENSION image_width; /* nominal image width (from SOF marker) */
452 JDIMENSION image_height; /* nominal image height */
453 int num_components; /* # of color components in JPEG image */
454 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
456 /* Decompression processing parameters --- these fields must be set before
457 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
458 * them to default values.
461 J_COLOR_SPACE out_color_space; /* colorspace for output */
463 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
465 unsigned int region_x, region_y, region_w, region_h; /* if region_w && region_h > 0, then use this region to decode. scale above is done prior to region select */
467 double output_gamma; /* image gamma wanted in output */
469 boolean buffered_image; /* TRUE=multiple output passes */
470 boolean raw_data_out; /* TRUE=downsampled data wanted */
472 J_DCT_METHOD dct_method; /* IDCT algorithm selector */
473 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
474 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
476 boolean quantize_colors; /* TRUE=colormapped output wanted */
477 /* the following are ignored if not quantize_colors: */
478 J_DITHER_MODE dither_mode; /* type of color dithering to use */
479 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
480 int desired_number_of_colors; /* max # colors to use in created colormap */
481 /* these are significant only in buffered-image mode: */
482 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
483 boolean enable_external_quant;/* enable future use of external colormap */
484 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
486 /* Description of actual output image that will be returned to application.
487 * These fields are computed by jpeg_start_decompress().
488 * You can also use jpeg_calc_output_dimensions() to determine these values
489 * in advance of calling jpeg_start_decompress().
492 JDIMENSION output_width; /* scaled image width */
493 JDIMENSION output_height; /* scaled image height */
494 int out_color_components; /* # of color components in out_color_space */
495 int output_components; /* # of color components returned */
496 /* output_components is 1 (a colormap index) when quantizing colors;
497 * otherwise it equals out_color_components.
499 int rec_outbuf_height; /* min recommended height of scanline buffer */
500 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
501 * high, space and time will be wasted due to unnecessary data copying.
502 * Usually rec_outbuf_height will be 1 or 2, at most 4.
505 /* When quantizing colors, the output colormap is described by these fields.
506 * The application can supply a colormap by setting colormap non-NULL before
507 * calling jpeg_start_decompress; otherwise a colormap is created during
508 * jpeg_start_decompress or jpeg_start_output.
509 * The map has out_color_components rows and actual_number_of_colors columns.
511 int actual_number_of_colors; /* number of entries in use */
512 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */
514 /* State variables: these variables indicate the progress of decompression.
515 * The application may examine these but must not modify them.
518 /* Row index of next scanline to be read from jpeg_read_scanlines().
519 * Application may use this to control its processing loop, e.g.,
520 * "while (output_scanline < output_height)".
522 JDIMENSION output_scanline; /* 0 .. output_height-1 */
524 /* Current input scan number and number of iMCU rows completed in scan.
525 * These indicate the progress of the decompressor input side.
527 int input_scan_number; /* Number of SOS markers seen so far */
528 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
530 /* The "output scan number" is the notional scan being displayed by the
531 * output side. The decompressor will not allow output scan/row number
532 * to get ahead of input scan/row, but it can fall arbitrarily far behind.
534 int output_scan_number; /* Nominal scan number being displayed */
535 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
537 /* Current progression status. coef_bits[c][i] indicates the precision
538 * with which component c's DCT coefficient i (in zigzag order) is known.
539 * It is -1 when no data has yet been received, otherwise it is the point
540 * transform (shift) value for the most recent scan of the coefficient
541 * (thus, 0 at completion of the progression).
542 * This pointer is NULL when reading a non-progressive file.
544 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
546 /* Internal JPEG parameters --- the application usually need not look at
547 * these fields. Note that the decompressor output side may not use
548 * any parameters that can change between scans.
551 /* Quantization and Huffman tables are carried forward across input
552 * datastreams when processing abbreviated JPEG datastreams.
555 JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
556 /* ptrs to coefficient quantization tables, or NULL if not defined */
558 JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
559 JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
560 /* ptrs to Huffman coding tables, or NULL if not defined */
562 /* These parameters are never carried across datastreams, since they
563 * are given in SOF/SOS markers or defined to be reset by SOI.
566 int data_precision; /* bits of precision in image data */
568 jpeg_component_info * comp_info;
569 /* comp_info[i] describes component that appears i'th in SOF */
571 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */
572 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
573 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
575 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
576 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
577 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
579 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
581 /* These fields record data obtained from optional markers recognized by
584 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
585 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
586 UINT8 JFIF_major_version; /* JFIF version number */
587 UINT8 JFIF_minor_version;
588 UINT8 density_unit; /* JFIF code for pixel size units */
589 UINT16 X_density; /* Horizontal pixel density */
590 UINT16 Y_density; /* Vertical pixel density */
591 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
592 UINT8 Adobe_transform; /* Color transform code from Adobe marker */
594 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
596 /* Aside from the specific data retained from APPn markers known to the
597 * library, the uninterpreted contents of any or all APPn and COM markers
598 * can be saved in a list for examination by the application.
600 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
602 /* Remaining fields are known throughout decompressor, but generally
603 * should not be touched by a surrounding application.
607 * These fields are computed during decompression startup
609 int max_h_samp_factor; /* largest h_samp_factor */
610 int max_v_samp_factor; /* largest v_samp_factor */
612 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
613 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
615 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
616 /* The coefficient controller's input and output progress is measured in
617 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
618 * in fully interleaved JPEG scans, but are used whether the scan is
619 * interleaved or not. We define an iMCU row as v_samp_factor DCT block
620 * rows of each component. Therefore, the IDCT output contains
621 * v_samp_factor*DCT_v_scaled_size sample rows of a component per iMCU row.
624 JSAMPLE * sample_range_limit; /* table for fast range-limiting */
627 * These fields are valid during any one scan.
628 * They describe the components and MCUs actually appearing in the scan.
629 * Note that the decompressor output side must not use these fields.
631 int comps_in_scan; /* # of JPEG components in this scan */
632 jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
633 /* *cur_comp_info[i] describes component that appears i'th in SOS */
635 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
636 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
638 int blocks_in_MCU; /* # of DCT blocks per MCU */
639 int MCU_membership[D_MAX_BLOCKS_IN_MCU];
640 /* MCU_membership[i] is index in cur_comp_info of component owning */
641 /* i'th block in an MCU */
643 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
645 /* These fields are derived from Se of first SOS marker.
647 int block_size; /* the basic DCT block size: 1..16 */
648 const int * natural_order; /* natural-order position array for entropy decode */
649 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */
651 /* This field is shared between entropy decoder and marker parser.
652 * It is either zero or the code of a JPEG marker that has been
653 * read from the data source, but has not yet been processed.
658 * Links to decompression subobjects (methods, private variables of modules)
660 struct jpeg_decomp_master * master;
661 struct jpeg_d_main_controller * main;
662 struct jpeg_d_coef_controller * coef;
663 struct jpeg_d_post_controller * post;
664 struct jpeg_input_controller * inputctl;
665 struct jpeg_marker_reader * marker;
666 struct jpeg_entropy_decoder * entropy;
667 struct jpeg_inverse_dct * idct;
668 struct jpeg_upsampler * upsample;
669 struct jpeg_color_deconverter * cconvert;
670 struct jpeg_color_quantizer * cquantize;
674 /* "Object" declarations for JPEG modules that may be supplied or called
675 * directly by the surrounding application.
676 * As with all objects in the JPEG library, these structs only define the
677 * publicly visible methods and state variables of a module. Additional
678 * private fields may exist after the public ones.
682 /* Error handler object */
684 struct jpeg_error_mgr {
685 /* Error exit handler: does not return to caller */
686 JMETHOD(void, error_exit, (j_common_ptr cinfo));
687 /* Conditionally emit a trace or warning message */
688 JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
689 /* Routine that actually outputs a trace or error message */
690 JMETHOD(void, output_message, (j_common_ptr cinfo));
691 /* Format a message string for the most recent JPEG error or message */
692 JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
693 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
694 /* Reset error state variables at start of a new image */
695 JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
697 /* The message ID code and any parameters are saved here.
698 * A message can have one string parameter or up to 8 int parameters.
701 #define JMSG_STR_PARM_MAX 80
704 char s[JMSG_STR_PARM_MAX];
707 /* Standard state variables for error facility */
709 int trace_level; /* max msg_level that will be displayed */
711 /* For recoverable corrupt-data errors, we emit a warning message,
712 * but keep going unless emit_message chooses to abort. emit_message
713 * should count warnings in num_warnings. The surrounding application
714 * can check for bad data by seeing if num_warnings is nonzero at the
717 long num_warnings; /* number of corrupt-data warnings */
719 /* These fields point to the table(s) of error message strings.
720 * An application can change the table pointer to switch to a different
721 * message list (typically, to change the language in which errors are
722 * reported). Some applications may wish to add additional error codes
723 * that will be handled by the JPEG library error mechanism; the second
724 * table pointer is used for this purpose.
726 * First table includes all errors generated by JPEG library itself.
727 * Error code 0 is reserved for a "no such error string" message.
729 const char * const * jpeg_message_table; /* Library errors */
730 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
731 /* Second table can be added by application (see cjpeg/djpeg for example).
732 * It contains strings numbered first_addon_message..last_addon_message.
734 const char * const * addon_message_table; /* Non-library errors */
735 int first_addon_message; /* code for first string in addon table */
736 int last_addon_message; /* code for last string in addon table */
740 /* Progress monitor object */
742 struct jpeg_progress_mgr {
743 JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
745 long pass_counter; /* work units completed in this pass */
746 long pass_limit; /* total number of work units in this pass */
747 int completed_passes; /* passes completed so far */
748 int total_passes; /* total number of passes expected */
752 /* Data destination object for compression */
754 struct jpeg_destination_mgr {
755 JOCTET * next_output_byte; /* => next byte to write in buffer */
756 size_t free_in_buffer; /* # of byte spaces remaining in buffer */
758 JMETHOD(void, init_destination, (j_compress_ptr cinfo));
759 JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
760 JMETHOD(void, term_destination, (j_compress_ptr cinfo));
764 /* Data source object for decompression */
766 struct jpeg_source_mgr {
767 const JOCTET * next_input_byte; /* => next byte to read from buffer */
768 size_t bytes_in_buffer; /* # of bytes remaining in buffer */
770 JMETHOD(void, init_source, (j_decompress_ptr cinfo));
771 JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
772 JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
773 JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
774 JMETHOD(void, term_source, (j_decompress_ptr cinfo));
778 /* Memory manager object.
779 * Allocates "small" objects (a few K total), "large" objects (tens of K),
780 * and "really big" objects (virtual arrays with backing store if needed).
781 * The memory manager does not allow individual objects to be freed; rather,
782 * each created object is assigned to a pool, and whole pools can be freed
783 * at once. This is faster and more convenient than remembering exactly what
784 * to free, especially where malloc()/free() are not too speedy.
785 * NB: alloc routines never return NULL. They exit to error_exit if not
789 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
790 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
791 #define JPOOL_NUMPOOLS 2
793 typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
794 typedef struct jvirt_barray_control * jvirt_barray_ptr;
797 struct jpeg_memory_mgr {
798 /* Method pointers */
799 JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
800 size_t sizeofobject));
801 JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
802 size_t sizeofobject));
803 JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
804 JDIMENSION samplesperrow,
805 JDIMENSION numrows));
806 JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
807 JDIMENSION blocksperrow,
808 JDIMENSION numrows));
809 JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
812 JDIMENSION samplesperrow,
814 JDIMENSION maxaccess));
815 JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
818 JDIMENSION blocksperrow,
820 JDIMENSION maxaccess));
821 JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
822 JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
823 jvirt_sarray_ptr ptr,
824 JDIMENSION start_row,
827 JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
828 jvirt_barray_ptr ptr,
829 JDIMENSION start_row,
832 JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
833 JMETHOD(void, self_destruct, (j_common_ptr cinfo));
835 /* Limit on memory allocation for this JPEG object. (Note that this is
836 * merely advisory, not a guaranteed maximum; it only affects the space
837 * used for virtual-array buffers.) May be changed by outer application
838 * after creating the JPEG object.
840 long max_memory_to_use;
842 /* Maximum allocation request accepted by alloc_large. */
843 long max_alloc_chunk;
847 /* Routine signature for application-supplied marker processing methods.
848 * Need not pass marker code since it is stored in cinfo->unread_marker.
850 typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
853 /* Declarations for routines called by application.
854 * The JPP macro hides prototype parameters from compilers that can't cope.
855 * Note JPP requires double parentheses.
858 #ifdef HAVE_PROTOTYPES
859 #define JPP(arglist) arglist
861 #define JPP(arglist) ()
865 /* Short forms of external names for systems with brain-damaged linkers.
866 * We shorten external names to be unique in the first six letters, which
867 * is good enough for all known systems.
868 * (If your compiler itself needs names to be unique in less than 15
869 * characters, you are out of luck. Get a better compiler.)
872 #ifdef NEED_SHORT_EXTERNAL_NAMES
873 #define jpeg_std_error jStdError
874 #define jpeg_CreateCompress jCreaCompress
875 #define jpeg_CreateDecompress jCreaDecompress
876 #define jpeg_destroy_compress jDestCompress
877 #define jpeg_destroy_decompress jDestDecompress
878 #define jpeg_stdio_dest jStdDest
879 #define jpeg_stdio_src jStdSrc
880 #define jpeg_mem_dest jMemDest
881 #define jpeg_mem_src jMemSrc
882 #define jpeg_set_defaults jSetDefaults
883 #define jpeg_set_colorspace jSetColorspace
884 #define jpeg_default_colorspace jDefColorspace
885 #define jpeg_set_quality jSetQuality
886 #define jpeg_set_linear_quality jSetLQuality
887 #define jpeg_default_qtables jDefQTables
888 #define jpeg_add_quant_table jAddQuantTable
889 #define jpeg_quality_scaling jQualityScaling
890 #define jpeg_simple_progression jSimProgress
891 #define jpeg_suppress_tables jSuppressTables
892 #define jpeg_alloc_quant_table jAlcQTable
893 #define jpeg_alloc_huff_table jAlcHTable
894 #define jpeg_start_compress jStrtCompress
895 #define jpeg_write_scanlines jWrtScanlines
896 #define jpeg_finish_compress jFinCompress
897 #define jpeg_calc_jpeg_dimensions jCjpegDimensions
898 #define jpeg_write_raw_data jWrtRawData
899 #define jpeg_write_marker jWrtMarker
900 #define jpeg_write_m_header jWrtMHeader
901 #define jpeg_write_m_byte jWrtMByte
902 #define jpeg_write_tables jWrtTables
903 #define jpeg_read_header jReadHeader
904 #define jpeg_start_decompress jStrtDecompress
905 #define jpeg_read_scanlines jReadScanlines
906 #define jpeg_finish_decompress jFinDecompress
907 #define jpeg_read_raw_data jReadRawData
908 #define jpeg_has_multiple_scans jHasMultScn
909 #define jpeg_start_output jStrtOutput
910 #define jpeg_finish_output jFinOutput
911 #define jpeg_input_complete jInComplete
912 #define jpeg_new_colormap jNewCMap
913 #define jpeg_consume_input jConsumeInput
914 #define jpeg_core_output_dimensions jCoreDimensions
915 #define jpeg_calc_output_dimensions jCalcDimensions
916 #define jpeg_save_markers jSaveMarkers
917 #define jpeg_set_marker_processor jSetMarker
918 #define jpeg_read_coefficients jReadCoefs
919 #define jpeg_write_coefficients jWrtCoefs
920 #define jpeg_copy_critical_parameters jCopyCrit
921 #define jpeg_abort_compress jAbrtCompress
922 #define jpeg_abort_decompress jAbrtDecompress
923 #define jpeg_abort jAbort
924 #define jpeg_destroy jDestroy
925 #define jpeg_resync_to_restart jResyncRestart
926 #endif /* NEED_SHORT_EXTERNAL_NAMES */
929 /* Default error-management setup */
930 EXTERN(struct jpeg_error_mgr *) jpeg_std_error
931 JPP((struct jpeg_error_mgr * err));
933 /* Initialization of JPEG compression objects.
934 * jpeg_create_compress() and jpeg_create_decompress() are the exported
935 * names that applications should call. These expand to calls on
936 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
937 * passed for version mismatch checking.
938 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
940 #define jpeg_create_compress(cinfo) \
941 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
942 (size_t) sizeof(struct jpeg_compress_struct))
943 #define jpeg_create_decompress(cinfo) \
944 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
945 (size_t) sizeof(struct jpeg_decompress_struct))
946 EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo,
947 int version, size_t structsize));
948 EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo,
949 int version, size_t structsize));
950 /* Destruction of JPEG compression objects */
951 EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo));
952 EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
954 /* Standard data source and destination managers: stdio streams. */
955 /* Caller is responsible for opening the file before and closing after. */
956 EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
957 EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile));
959 /* Data source and destination managers: memory buffers. */
960 EXTERN(void) jpeg_mem_dest JPP((j_compress_ptr cinfo,
961 unsigned char ** outbuffer,
962 unsigned long * outsize));
963 EXTERN(void) jpeg_mem_src JPP((j_decompress_ptr cinfo,
964 unsigned char * inbuffer,
965 unsigned long insize));
967 /* Default parameter setup for compression */
968 EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo));
969 /* Compression parameter setup aids */
970 EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo,
971 J_COLOR_SPACE colorspace));
972 EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo));
973 EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
974 boolean force_baseline));
975 EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
977 boolean force_baseline));
978 EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo,
979 boolean force_baseline));
980 EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
981 const unsigned int *basic_table,
983 boolean force_baseline));
984 EXTERN(int) jpeg_quality_scaling JPP((int quality));
985 EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo));
986 EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo,
988 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo));
989 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo));
991 /* Main entry points for compression */
992 EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo,
993 boolean write_all_tables));
994 EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo,
995 JSAMPARRAY scanlines,
996 JDIMENSION num_lines));
997 EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo));
999 /* Precalculate JPEG dimensions for current compression parameters. */
1000 EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo));
1002 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
1003 EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo,
1005 JDIMENSION num_lines));
1007 /* Write a special marker. See libjpeg.txt concerning safe usage. */
1008 EXTERN(void) jpeg_write_marker
1009 JPP((j_compress_ptr cinfo, int marker,
1010 const JOCTET * dataptr, unsigned int datalen));
1011 /* Same, but piecemeal. */
1012 EXTERN(void) jpeg_write_m_header
1013 JPP((j_compress_ptr cinfo, int marker, unsigned int datalen));
1014 EXTERN(void) jpeg_write_m_byte
1015 JPP((j_compress_ptr cinfo, int val));
1017 /* Alternate compression function: just write an abbreviated table file */
1018 EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo));
1020 /* Decompression startup: read start of JPEG datastream to see what's there */
1021 EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo,
1022 boolean require_image));
1023 /* Return value is one of: */
1024 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
1025 #define JPEG_HEADER_OK 1 /* Found valid image datastream */
1026 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
1027 /* If you pass require_image = TRUE (normal case), you need not check for
1028 * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
1029 * JPEG_SUSPENDED is only possible if you use a data source module that can
1030 * give a suspension return (the stdio source module doesn't).
1033 /* Main entry points for decompression */
1034 EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo));
1035 EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
1036 JSAMPARRAY scanlines,
1037 JDIMENSION max_lines));
1038 EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
1040 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
1041 EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
1043 JDIMENSION max_lines));
1045 /* Additional entry points for buffered-image mode. */
1046 EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
1047 EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo,
1049 EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo));
1050 EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo));
1051 EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo));
1052 EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo));
1053 /* Return value is one of: */
1054 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
1055 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */
1056 #define JPEG_REACHED_EOI 2 /* Reached end of image */
1057 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
1058 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
1060 /* Precalculate output dimensions for current decompression parameters. */
1061 EXTERN(void) jpeg_core_output_dimensions JPP((j_decompress_ptr cinfo));
1062 EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo));
1064 /* Control saving of COM and APPn markers into marker_list. */
1065 EXTERN(void) jpeg_save_markers
1066 JPP((j_decompress_ptr cinfo, int marker_code,
1067 unsigned int length_limit));
1069 /* Install a special processing method for COM or APPn markers. */
1070 EXTERN(void) jpeg_set_marker_processor
1071 JPP((j_decompress_ptr cinfo, int marker_code,
1072 jpeg_marker_parser_method routine));
1074 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
1075 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo));
1076 EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo,
1077 jvirt_barray_ptr * coef_arrays));
1078 EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo,
1079 j_compress_ptr dstinfo));
1081 /* If you choose to abort compression or decompression before completing
1082 * jpeg_finish_(de)compress, then you need to clean up to release memory,
1083 * temporary files, etc. You can just call jpeg_destroy_(de)compress
1084 * if you're done with the JPEG object, but if you want to clean it up and
1085 * reuse it, call this:
1087 EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo));
1088 EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo));
1090 /* Generic versions of jpeg_abort and jpeg_destroy that work on either
1091 * flavor of JPEG object. These may be more convenient in some places.
1093 EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo));
1094 EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo));
1096 /* Default restart-marker-resync procedure for use by data source modules */
1097 EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo,
1101 /* These marker codes are exported since applications and data source modules
1102 * are likely to want to use them.
1105 #define JPEG_RST0 0xD0 /* RST0 marker code */
1106 #define JPEG_EOI 0xD9 /* EOI marker code */
1107 #define JPEG_APP0 0xE0 /* APP0 marker code */
1108 #define JPEG_COM 0xFE /* COM marker code */
1111 /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1112 * for structure definitions that are never filled in, keep it quiet by
1113 * supplying dummy definitions for the various substructures.
1116 #ifdef INCOMPLETE_TYPES_BROKEN
1117 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
1118 struct jvirt_sarray_control { long dummy; };
1119 struct jvirt_barray_control { long dummy; };
1120 struct jpeg_comp_master { long dummy; };
1121 struct jpeg_c_main_controller { long dummy; };
1122 struct jpeg_c_prep_controller { long dummy; };
1123 struct jpeg_c_coef_controller { long dummy; };
1124 struct jpeg_marker_writer { long dummy; };
1125 struct jpeg_color_converter { long dummy; };
1126 struct jpeg_downsampler { long dummy; };
1127 struct jpeg_forward_dct { long dummy; };
1128 struct jpeg_entropy_encoder { long dummy; };
1129 struct jpeg_decomp_master { long dummy; };
1130 struct jpeg_d_main_controller { long dummy; };
1131 struct jpeg_d_coef_controller { long dummy; };
1132 struct jpeg_d_post_controller { long dummy; };
1133 struct jpeg_input_controller { long dummy; };
1134 struct jpeg_marker_reader { long dummy; };
1135 struct jpeg_entropy_decoder { long dummy; };
1136 struct jpeg_inverse_dct { long dummy; };
1137 struct jpeg_upsampler { long dummy; };
1138 struct jpeg_color_deconverter { long dummy; };
1139 struct jpeg_color_quantizer { long dummy; };
1140 #endif /* JPEG_INTERNALS */
1141 #endif /* INCOMPLETE_TYPES_BROKEN */
1145 * The JPEG library modules define JPEG_INTERNALS before including this file.
1146 * The internal structure declarations are read only when that is true.
1147 * Applications using the library should not include jpegint.h, but may wish
1148 * to include jerror.h.
1151 #ifdef JPEG_INTERNALS
1152 #include "jpegint.h" /* fetch private declarations */
1153 #include "jerror.h" /* fetch error codes too */
1157 #ifndef DONT_USE_EXTERN_C
1162 #endif /* JPEGLIB_H */