4 * Copyright (C) 1991-1998, Thomas G. Lane.
5 * Modified 2002-2012 by Guido Vollbeding.
6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file.
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 >= 90".
40 #define JPEG_LIB_VERSION 90 /* Compatibility version 9.0 */
41 #define JPEG_LIB_VERSION_MAJOR 9
42 #define JPEG_LIB_VERSION_MINOR 0
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 coefficients */
51 #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
52 #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
53 #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
54 #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
55 #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
56 #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
57 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
58 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
59 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
60 * to handle it. We even let you do this from the jconfig.h file. However,
61 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
62 * sometimes emits noncompliant files doesn't mean you should too.
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 /* Supported color transforms. */
228 JCT_SUBTRACT_GREEN
= 1
231 /* DCT/IDCT algorithm options. */
234 JDCT_ISLOW
, /* slow but accurate integer algorithm */
235 JDCT_IFAST
, /* faster, less accurate integer method */
236 JDCT_FLOAT
/* floating-point: accurate, fast on fast HW */
239 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
240 #define JDCT_DEFAULT JDCT_ISLOW
242 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
243 #define JDCT_FASTEST JDCT_IFAST
246 /* Dithering options for decompression. */
249 JDITHER_NONE
, /* no dithering */
250 JDITHER_ORDERED
, /* simple ordered dither */
251 JDITHER_FS
/* Floyd-Steinberg error diffusion dither */
255 /* Common fields between JPEG compression and decompression master structs. */
257 #define jpeg_common_fields \
258 struct jpeg_error_mgr * err; /* Error handler module */\
259 struct jpeg_memory_mgr * mem; /* Memory manager module */\
260 struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
261 void * client_data; /* Available for use by application */\
262 boolean is_decompressor; /* So common code can tell which is which */\
263 int global_state /* For checking call sequence validity */
265 /* Routines that are to be used by both halves of the library are declared
266 * to receive a pointer to this structure. There are no actual instances of
267 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
269 struct jpeg_common_struct
{
270 jpeg_common_fields
; /* Fields common to both master struct types */
271 /* Additional fields follow in an actual jpeg_compress_struct or
272 * jpeg_decompress_struct. All three structs must agree on these
273 * initial fields! (This would be a lot cleaner in C++.)
277 typedef struct jpeg_common_struct
* j_common_ptr
;
278 typedef struct jpeg_compress_struct
* j_compress_ptr
;
279 typedef struct jpeg_decompress_struct
* j_decompress_ptr
;
282 /* Master record for a compression instance */
284 struct jpeg_compress_struct
{
285 jpeg_common_fields
; /* Fields shared with jpeg_decompress_struct */
287 /* Destination for compressed data */
288 struct jpeg_destination_mgr
* dest
;
290 /* Description of source image --- these fields must be filled in by
291 * outer application before starting compression. in_color_space must
292 * be correct before you can even call jpeg_set_defaults().
295 JDIMENSION image_width
; /* input image width */
296 JDIMENSION image_height
; /* input image height */
297 int input_components
; /* # of color components in input image */
298 J_COLOR_SPACE in_color_space
; /* colorspace of input image */
300 double input_gamma
; /* image gamma of input image */
302 /* Compression parameters --- these fields must be set before calling
303 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
304 * initialize everything to reasonable defaults, then changing anything
305 * the application specifically wants to change. That way you won't get
306 * burnt when new parameters are added. Also note that there are several
307 * helper routines to simplify changing parameters.
310 unsigned int scale_num
, scale_denom
; /* fraction by which to scale image */
312 JDIMENSION jpeg_width
; /* scaled JPEG image width */
313 JDIMENSION jpeg_height
; /* scaled JPEG image height */
314 /* Dimensions of actual JPEG image that will be written to file,
315 * derived from input dimensions by scaling factors above.
316 * These fields are computed by jpeg_start_compress().
317 * You can also use jpeg_calc_jpeg_dimensions() to determine these values
318 * in advance of calling jpeg_start_compress().
321 int data_precision
; /* bits of precision in image data */
323 int num_components
; /* # of color components in JPEG image */
324 J_COLOR_SPACE jpeg_color_space
; /* colorspace of JPEG image */
326 jpeg_component_info
* comp_info
;
327 /* comp_info[i] describes component that appears i'th in SOF */
329 JQUANT_TBL
* quant_tbl_ptrs
[NUM_QUANT_TBLS
];
330 int q_scale_factor
[NUM_QUANT_TBLS
];
331 /* ptrs to coefficient quantization tables, or NULL if not defined,
332 * and corresponding scale factors (percentage, initialized 100).
335 JHUFF_TBL
* dc_huff_tbl_ptrs
[NUM_HUFF_TBLS
];
336 JHUFF_TBL
* ac_huff_tbl_ptrs
[NUM_HUFF_TBLS
];
337 /* ptrs to Huffman coding tables, or NULL if not defined */
339 UINT8 arith_dc_L
[NUM_ARITH_TBLS
]; /* L values for DC arith-coding tables */
340 UINT8 arith_dc_U
[NUM_ARITH_TBLS
]; /* U values for DC arith-coding tables */
341 UINT8 arith_ac_K
[NUM_ARITH_TBLS
]; /* Kx values for AC arith-coding tables */
343 int num_scans
; /* # of entries in scan_info array */
344 const jpeg_scan_info
* scan_info
; /* script for multi-scan file, or NULL */
345 /* The default value of scan_info is NULL, which causes a single-scan
346 * sequential JPEG file to be emitted. To create a multi-scan file,
347 * set num_scans and scan_info to point to an array of scan definitions.
350 boolean raw_data_in
; /* TRUE=caller supplies downsampled data */
351 boolean arith_code
; /* TRUE=arithmetic coding, FALSE=Huffman */
352 boolean optimize_coding
; /* TRUE=optimize entropy encoding parms */
353 boolean CCIR601_sampling
; /* TRUE=first samples are cosited */
354 boolean do_fancy_downsampling
; /* TRUE=apply fancy downsampling */
355 int smoothing_factor
; /* 1..100, or 0 for no input smoothing */
356 J_DCT_METHOD dct_method
; /* DCT algorithm selector */
358 /* The restart interval can be specified in absolute MCUs by setting
359 * restart_interval, or in MCU rows by setting restart_in_rows
360 * (in which case the correct restart_interval will be figured
363 unsigned int restart_interval
; /* MCUs per restart, or 0 for no restart */
364 int restart_in_rows
; /* if > 0, MCU rows per restart interval */
366 /* Parameters controlling emission of special markers. */
368 boolean write_JFIF_header
; /* should a JFIF marker be written? */
369 UINT8 JFIF_major_version
; /* What to write for the JFIF version number */
370 UINT8 JFIF_minor_version
;
371 /* These three values are not used by the JPEG code, merely copied */
372 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
373 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
374 /* ratio is defined by X_density/Y_density even when density_unit=0. */
375 UINT8 density_unit
; /* JFIF code for pixel size units */
376 UINT16 X_density
; /* Horizontal pixel density */
377 UINT16 Y_density
; /* Vertical pixel density */
378 boolean write_Adobe_marker
; /* should an Adobe marker be written? */
380 J_COLOR_TRANSFORM color_transform
;
381 /* Color transform identifier, writes LSE marker if nonzero */
383 /* State variable: index of next scanline to be written to
384 * jpeg_write_scanlines(). Application may use this to control its
385 * processing loop, e.g., "while (next_scanline < image_height)".
388 JDIMENSION next_scanline
; /* 0 .. image_height-1 */
390 /* Remaining fields are known throughout compressor, but generally
391 * should not be touched by a surrounding application.
395 * These fields are computed during compression startup
397 boolean progressive_mode
; /* TRUE if scan script uses progressive mode */
398 int max_h_samp_factor
; /* largest h_samp_factor */
399 int max_v_samp_factor
; /* largest v_samp_factor */
401 int min_DCT_h_scaled_size
; /* smallest DCT_h_scaled_size of any component */
402 int min_DCT_v_scaled_size
; /* smallest DCT_v_scaled_size of any component */
404 JDIMENSION total_iMCU_rows
; /* # of iMCU rows to be input to coef ctlr */
405 /* The coefficient controller receives data in units of MCU rows as defined
406 * for fully interleaved scans (whether the JPEG file is interleaved or not).
407 * There are v_samp_factor * DCTSIZE sample rows of each component in an
408 * "iMCU" (interleaved MCU) row.
412 * These fields are valid during any one scan.
413 * They describe the components and MCUs actually appearing in the scan.
415 int comps_in_scan
; /* # of JPEG components in this scan */
416 jpeg_component_info
* cur_comp_info
[MAX_COMPS_IN_SCAN
];
417 /* *cur_comp_info[i] describes component that appears i'th in SOS */
419 JDIMENSION MCUs_per_row
; /* # of MCUs across the image */
420 JDIMENSION MCU_rows_in_scan
; /* # of MCU rows in the image */
422 int blocks_in_MCU
; /* # of DCT blocks per MCU */
423 int MCU_membership
[C_MAX_BLOCKS_IN_MCU
];
424 /* MCU_membership[i] is index in cur_comp_info of component owning */
425 /* i'th block in an MCU */
427 int Ss
, Se
, Ah
, Al
; /* progressive JPEG parameters for scan */
429 int block_size
; /* the basic DCT block size: 1..16 */
430 const int * natural_order
; /* natural-order position array */
431 int lim_Se
; /* min( Se, DCTSIZE2-1 ) */
434 * Links to compression subobjects (methods and private variables of modules)
436 struct jpeg_comp_master
* master
;
437 struct jpeg_c_main_controller
* main
;
438 struct jpeg_c_prep_controller
* prep
;
439 struct jpeg_c_coef_controller
* coef
;
440 struct jpeg_marker_writer
* marker
;
441 struct jpeg_color_converter
* cconvert
;
442 struct jpeg_downsampler
* downsample
;
443 struct jpeg_forward_dct
* fdct
;
444 struct jpeg_entropy_encoder
* entropy
;
445 jpeg_scan_info
* script_space
; /* workspace for jpeg_simple_progression */
446 int script_space_size
;
450 /* Master record for a decompression instance */
452 struct jpeg_decompress_struct
{
453 jpeg_common_fields
; /* Fields shared with jpeg_compress_struct */
455 /* Source of compressed data */
456 struct jpeg_source_mgr
* src
;
458 /* Basic description of image --- filled in by jpeg_read_header(). */
459 /* Application may inspect these values to decide how to process image. */
461 JDIMENSION image_width
; /* nominal image width (from SOF marker) */
462 JDIMENSION image_height
; /* nominal image height */
463 int num_components
; /* # of color components in JPEG image */
464 J_COLOR_SPACE jpeg_color_space
; /* colorspace of JPEG image */
466 /* Decompression processing parameters --- these fields must be set before
467 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
468 * them to default values.
471 J_COLOR_SPACE out_color_space
; /* colorspace for output */
473 unsigned int scale_num
, scale_denom
; /* fraction by which to scale image */
475 double output_gamma
; /* image gamma wanted in output */
477 boolean buffered_image
; /* TRUE=multiple output passes */
478 boolean raw_data_out
; /* TRUE=downsampled data wanted */
480 J_DCT_METHOD dct_method
; /* IDCT algorithm selector */
481 boolean do_fancy_upsampling
; /* TRUE=apply fancy upsampling */
482 boolean do_block_smoothing
; /* TRUE=apply interblock smoothing */
484 boolean quantize_colors
; /* TRUE=colormapped output wanted */
485 /* the following are ignored if not quantize_colors: */
486 J_DITHER_MODE dither_mode
; /* type of color dithering to use */
487 boolean two_pass_quantize
; /* TRUE=use two-pass color quantization */
488 int desired_number_of_colors
; /* max # colors to use in created colormap */
489 /* these are significant only in buffered-image mode: */
490 boolean enable_1pass_quant
; /* enable future use of 1-pass quantizer */
491 boolean enable_external_quant
;/* enable future use of external colormap */
492 boolean enable_2pass_quant
; /* enable future use of 2-pass quantizer */
494 /* Description of actual output image that will be returned to application.
495 * These fields are computed by jpeg_start_decompress().
496 * You can also use jpeg_calc_output_dimensions() to determine these values
497 * in advance of calling jpeg_start_decompress().
500 JDIMENSION output_width
; /* scaled image width */
501 JDIMENSION output_height
; /* scaled image height */
502 int out_color_components
; /* # of color components in out_color_space */
503 int output_components
; /* # of color components returned */
504 /* output_components is 1 (a colormap index) when quantizing colors;
505 * otherwise it equals out_color_components.
507 int rec_outbuf_height
; /* min recommended height of scanline buffer */
508 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
509 * high, space and time will be wasted due to unnecessary data copying.
510 * Usually rec_outbuf_height will be 1 or 2, at most 4.
513 /* When quantizing colors, the output colormap is described by these fields.
514 * The application can supply a colormap by setting colormap non-NULL before
515 * calling jpeg_start_decompress; otherwise a colormap is created during
516 * jpeg_start_decompress or jpeg_start_output.
517 * The map has out_color_components rows and actual_number_of_colors columns.
519 int actual_number_of_colors
; /* number of entries in use */
520 JSAMPARRAY colormap
; /* The color map as a 2-D pixel array */
522 /* State variables: these variables indicate the progress of decompression.
523 * The application may examine these but must not modify them.
526 /* Row index of next scanline to be read from jpeg_read_scanlines().
527 * Application may use this to control its processing loop, e.g.,
528 * "while (output_scanline < output_height)".
530 JDIMENSION output_scanline
; /* 0 .. output_height-1 */
532 /* Current input scan number and number of iMCU rows completed in scan.
533 * These indicate the progress of the decompressor input side.
535 int input_scan_number
; /* Number of SOS markers seen so far */
536 JDIMENSION input_iMCU_row
; /* Number of iMCU rows completed */
538 /* The "output scan number" is the notional scan being displayed by the
539 * output side. The decompressor will not allow output scan/row number
540 * to get ahead of input scan/row, but it can fall arbitrarily far behind.
542 int output_scan_number
; /* Nominal scan number being displayed */
543 JDIMENSION output_iMCU_row
; /* Number of iMCU rows read */
545 /* Current progression status. coef_bits[c][i] indicates the precision
546 * with which component c's DCT coefficient i (in zigzag order) is known.
547 * It is -1 when no data has yet been received, otherwise it is the point
548 * transform (shift) value for the most recent scan of the coefficient
549 * (thus, 0 at completion of the progression).
550 * This pointer is NULL when reading a non-progressive file.
552 int (*coef_bits
)[DCTSIZE2
]; /* -1 or current Al value for each coef */
554 /* Internal JPEG parameters --- the application usually need not look at
555 * these fields. Note that the decompressor output side may not use
556 * any parameters that can change between scans.
559 /* Quantization and Huffman tables are carried forward across input
560 * datastreams when processing abbreviated JPEG datastreams.
563 JQUANT_TBL
* quant_tbl_ptrs
[NUM_QUANT_TBLS
];
564 /* ptrs to coefficient quantization tables, or NULL if not defined */
566 JHUFF_TBL
* dc_huff_tbl_ptrs
[NUM_HUFF_TBLS
];
567 JHUFF_TBL
* ac_huff_tbl_ptrs
[NUM_HUFF_TBLS
];
568 /* ptrs to Huffman coding tables, or NULL if not defined */
570 /* These parameters are never carried across datastreams, since they
571 * are given in SOF/SOS markers or defined to be reset by SOI.
574 int data_precision
; /* bits of precision in image data */
576 jpeg_component_info
* comp_info
;
577 /* comp_info[i] describes component that appears i'th in SOF */
579 boolean is_baseline
; /* TRUE if Baseline SOF0 encountered */
580 boolean progressive_mode
; /* TRUE if SOFn specifies progressive mode */
581 boolean arith_code
; /* TRUE=arithmetic coding, FALSE=Huffman */
583 UINT8 arith_dc_L
[NUM_ARITH_TBLS
]; /* L values for DC arith-coding tables */
584 UINT8 arith_dc_U
[NUM_ARITH_TBLS
]; /* U values for DC arith-coding tables */
585 UINT8 arith_ac_K
[NUM_ARITH_TBLS
]; /* Kx values for AC arith-coding tables */
587 unsigned int restart_interval
; /* MCUs per restart interval, or 0 for no restart */
589 /* These fields record data obtained from optional markers recognized by
592 boolean saw_JFIF_marker
; /* TRUE iff a JFIF APP0 marker was found */
593 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
594 UINT8 JFIF_major_version
; /* JFIF version number */
595 UINT8 JFIF_minor_version
;
596 UINT8 density_unit
; /* JFIF code for pixel size units */
597 UINT16 X_density
; /* Horizontal pixel density */
598 UINT16 Y_density
; /* Vertical pixel density */
599 boolean saw_Adobe_marker
; /* TRUE iff an Adobe APP14 marker was found */
600 UINT8 Adobe_transform
; /* Color transform code from Adobe marker */
602 J_COLOR_TRANSFORM color_transform
;
603 /* Color transform identifier derived from LSE marker, otherwise zero */
605 boolean CCIR601_sampling
; /* TRUE=first samples are cosited */
607 /* Aside from the specific data retained from APPn markers known to the
608 * library, the uninterpreted contents of any or all APPn and COM markers
609 * can be saved in a list for examination by the application.
611 jpeg_saved_marker_ptr marker_list
; /* Head of list of saved markers */
613 /* Remaining fields are known throughout decompressor, but generally
614 * should not be touched by a surrounding application.
618 * These fields are computed during decompression startup
620 int max_h_samp_factor
; /* largest h_samp_factor */
621 int max_v_samp_factor
; /* largest v_samp_factor */
623 int min_DCT_h_scaled_size
; /* smallest DCT_h_scaled_size of any component */
624 int min_DCT_v_scaled_size
; /* smallest DCT_v_scaled_size of any component */
626 JDIMENSION total_iMCU_rows
; /* # of iMCU rows in image */
627 /* The coefficient controller's input and output progress is measured in
628 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
629 * in fully interleaved JPEG scans, but are used whether the scan is
630 * interleaved or not. We define an iMCU row as v_samp_factor DCT block
631 * rows of each component. Therefore, the IDCT output contains
632 * v_samp_factor*DCT_v_scaled_size sample rows of a component per iMCU row.
635 JSAMPLE
* sample_range_limit
; /* table for fast range-limiting */
638 * These fields are valid during any one scan.
639 * They describe the components and MCUs actually appearing in the scan.
640 * Note that the decompressor output side must not use these fields.
642 int comps_in_scan
; /* # of JPEG components in this scan */
643 jpeg_component_info
* cur_comp_info
[MAX_COMPS_IN_SCAN
];
644 /* *cur_comp_info[i] describes component that appears i'th in SOS */
646 JDIMENSION MCUs_per_row
; /* # of MCUs across the image */
647 JDIMENSION MCU_rows_in_scan
; /* # of MCU rows in the image */
649 int blocks_in_MCU
; /* # of DCT blocks per MCU */
650 int MCU_membership
[D_MAX_BLOCKS_IN_MCU
];
651 /* MCU_membership[i] is index in cur_comp_info of component owning */
652 /* i'th block in an MCU */
654 int Ss
, Se
, Ah
, Al
; /* progressive JPEG parameters for scan */
656 /* These fields are derived from Se of first SOS marker.
658 int block_size
; /* the basic DCT block size: 1..16 */
659 const int * natural_order
; /* natural-order position array for entropy decode */
660 int lim_Se
; /* min( Se, DCTSIZE2-1 ) for entropy decode */
662 /* This field is shared between entropy decoder and marker parser.
663 * It is either zero or the code of a JPEG marker that has been
664 * read from the data source, but has not yet been processed.
669 * Links to decompression subobjects (methods, private variables of modules)
671 struct jpeg_decomp_master
* master
;
672 struct jpeg_d_main_controller
* main
;
673 struct jpeg_d_coef_controller
* coef
;
674 struct jpeg_d_post_controller
* post
;
675 struct jpeg_input_controller
* inputctl
;
676 struct jpeg_marker_reader
* marker
;
677 struct jpeg_entropy_decoder
* entropy
;
678 struct jpeg_inverse_dct
* idct
;
679 struct jpeg_upsampler
* upsample
;
680 struct jpeg_color_deconverter
* cconvert
;
681 struct jpeg_color_quantizer
* cquantize
;
685 /* "Object" declarations for JPEG modules that may be supplied or called
686 * directly by the surrounding application.
687 * As with all objects in the JPEG library, these structs only define the
688 * publicly visible methods and state variables of a module. Additional
689 * private fields may exist after the public ones.
693 /* Error handler object */
695 struct jpeg_error_mgr
{
696 /* Error exit handler: does not return to caller */
697 JMETHOD(noreturn_t
, error_exit
, (j_common_ptr cinfo
));
698 /* Conditionally emit a trace or warning message */
699 JMETHOD(void, emit_message
, (j_common_ptr cinfo
, int msg_level
));
700 /* Routine that actually outputs a trace or error message */
701 JMETHOD(void, output_message
, (j_common_ptr cinfo
));
702 /* Format a message string for the most recent JPEG error or message */
703 JMETHOD(void, format_message
, (j_common_ptr cinfo
, char * buffer
));
704 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
705 /* Reset error state variables at start of a new image */
706 JMETHOD(void, reset_error_mgr
, (j_common_ptr cinfo
));
708 /* The message ID code and any parameters are saved here.
709 * A message can have one string parameter or up to 8 int parameters.
712 #define JMSG_STR_PARM_MAX 80
715 char s
[JMSG_STR_PARM_MAX
];
718 /* Standard state variables for error facility */
720 int trace_level
; /* max msg_level that will be displayed */
722 /* For recoverable corrupt-data errors, we emit a warning message,
723 * but keep going unless emit_message chooses to abort. emit_message
724 * should count warnings in num_warnings. The surrounding application
725 * can check for bad data by seeing if num_warnings is nonzero at the
728 long num_warnings
; /* number of corrupt-data warnings */
730 /* These fields point to the table(s) of error message strings.
731 * An application can change the table pointer to switch to a different
732 * message list (typically, to change the language in which errors are
733 * reported). Some applications may wish to add additional error codes
734 * that will be handled by the JPEG library error mechanism; the second
735 * table pointer is used for this purpose.
737 * First table includes all errors generated by JPEG library itself.
738 * Error code 0 is reserved for a "no such error string" message.
740 const char * const * jpeg_message_table
; /* Library errors */
741 int last_jpeg_message
; /* Table contains strings 0..last_jpeg_message */
742 /* Second table can be added by application (see cjpeg/djpeg for example).
743 * It contains strings numbered first_addon_message..last_addon_message.
745 const char * const * addon_message_table
; /* Non-library errors */
746 int first_addon_message
; /* code for first string in addon table */
747 int last_addon_message
; /* code for last string in addon table */
751 /* Progress monitor object */
753 struct jpeg_progress_mgr
{
754 JMETHOD(void, progress_monitor
, (j_common_ptr cinfo
));
756 long pass_counter
; /* work units completed in this pass */
757 long pass_limit
; /* total number of work units in this pass */
758 int completed_passes
; /* passes completed so far */
759 int total_passes
; /* total number of passes expected */
763 /* Data destination object for compression */
765 struct jpeg_destination_mgr
{
766 JOCTET
* next_output_byte
; /* => next byte to write in buffer */
767 size_t free_in_buffer
; /* # of byte spaces remaining in buffer */
769 JMETHOD(void, init_destination
, (j_compress_ptr cinfo
));
770 JMETHOD(boolean
, empty_output_buffer
, (j_compress_ptr cinfo
));
771 JMETHOD(void, term_destination
, (j_compress_ptr cinfo
));
775 /* Data source object for decompression */
777 struct jpeg_source_mgr
{
778 const JOCTET
* next_input_byte
; /* => next byte to read from buffer */
779 size_t bytes_in_buffer
; /* # of bytes remaining in buffer */
781 JMETHOD(void, init_source
, (j_decompress_ptr cinfo
));
782 JMETHOD(boolean
, fill_input_buffer
, (j_decompress_ptr cinfo
));
783 JMETHOD(void, skip_input_data
, (j_decompress_ptr cinfo
, long num_bytes
));
784 JMETHOD(boolean
, resync_to_restart
, (j_decompress_ptr cinfo
, int desired
));
785 JMETHOD(void, term_source
, (j_decompress_ptr cinfo
));
789 /* Memory manager object.
790 * Allocates "small" objects (a few K total), "large" objects (tens of K),
791 * and "really big" objects (virtual arrays with backing store if needed).
792 * The memory manager does not allow individual objects to be freed; rather,
793 * each created object is assigned to a pool, and whole pools can be freed
794 * at once. This is faster and more convenient than remembering exactly what
795 * to free, especially where malloc()/free() are not too speedy.
796 * NB: alloc routines never return NULL. They exit to error_exit if not
800 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
801 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
802 #define JPOOL_NUMPOOLS 2
804 typedef struct jvirt_sarray_control
* jvirt_sarray_ptr
;
805 typedef struct jvirt_barray_control
* jvirt_barray_ptr
;
808 struct jpeg_memory_mgr
{
809 /* Method pointers */
810 JMETHOD(void *, alloc_small
, (j_common_ptr cinfo
, int pool_id
,
811 size_t sizeofobject
));
812 JMETHOD(void FAR
*, alloc_large
, (j_common_ptr cinfo
, int pool_id
,
813 size_t sizeofobject
));
814 JMETHOD(JSAMPARRAY
, alloc_sarray
, (j_common_ptr cinfo
, int pool_id
,
815 JDIMENSION samplesperrow
,
816 JDIMENSION numrows
));
817 JMETHOD(JBLOCKARRAY
, alloc_barray
, (j_common_ptr cinfo
, int pool_id
,
818 JDIMENSION blocksperrow
,
819 JDIMENSION numrows
));
820 JMETHOD(jvirt_sarray_ptr
, request_virt_sarray
, (j_common_ptr cinfo
,
823 JDIMENSION samplesperrow
,
825 JDIMENSION maxaccess
));
826 JMETHOD(jvirt_barray_ptr
, request_virt_barray
, (j_common_ptr cinfo
,
829 JDIMENSION blocksperrow
,
831 JDIMENSION maxaccess
));
832 JMETHOD(void, realize_virt_arrays
, (j_common_ptr cinfo
));
833 JMETHOD(JSAMPARRAY
, access_virt_sarray
, (j_common_ptr cinfo
,
834 jvirt_sarray_ptr ptr
,
835 JDIMENSION start_row
,
838 JMETHOD(JBLOCKARRAY
, access_virt_barray
, (j_common_ptr cinfo
,
839 jvirt_barray_ptr ptr
,
840 JDIMENSION start_row
,
843 JMETHOD(void, free_pool
, (j_common_ptr cinfo
, int pool_id
));
844 JMETHOD(void, self_destruct
, (j_common_ptr cinfo
));
846 /* Limit on memory allocation for this JPEG object. (Note that this is
847 * merely advisory, not a guaranteed maximum; it only affects the space
848 * used for virtual-array buffers.) May be changed by outer application
849 * after creating the JPEG object.
851 long max_memory_to_use
;
853 /* Maximum allocation request accepted by alloc_large. */
854 long max_alloc_chunk
;
858 /* Routine signature for application-supplied marker processing methods.
859 * Need not pass marker code since it is stored in cinfo->unread_marker.
861 typedef JMETHOD(boolean
, jpeg_marker_parser_method
, (j_decompress_ptr cinfo
));
864 /* Declarations for routines called by application.
865 * The JPP macro hides prototype parameters from compilers that can't cope.
866 * Note JPP requires double parentheses.
869 #ifdef HAVE_PROTOTYPES
870 #define JPP(arglist) arglist
872 #define JPP(arglist) ()
876 /* Short forms of external names for systems with brain-damaged linkers.
877 * We shorten external names to be unique in the first six letters, which
878 * is good enough for all known systems.
879 * (If your compiler itself needs names to be unique in less than 15
880 * characters, you are out of luck. Get a better compiler.)
883 #ifdef NEED_SHORT_EXTERNAL_NAMES
884 #define jpeg_std_error jStdError
885 #define jpeg_CreateCompress jCreaCompress
886 #define jpeg_CreateDecompress jCreaDecompress
887 #define jpeg_destroy_compress jDestCompress
888 #define jpeg_destroy_decompress jDestDecompress
889 #define jpeg_stdio_dest jStdDest
890 #define jpeg_stdio_src jStdSrc
891 #define jpeg_mem_dest jMemDest
892 #define jpeg_mem_src jMemSrc
893 #define jpeg_set_defaults jSetDefaults
894 #define jpeg_set_colorspace jSetColorspace
895 #define jpeg_default_colorspace jDefColorspace
896 #define jpeg_set_quality jSetQuality
897 #define jpeg_set_linear_quality jSetLQuality
898 #define jpeg_default_qtables jDefQTables
899 #define jpeg_add_quant_table jAddQuantTable
900 #define jpeg_quality_scaling jQualityScaling
901 #define jpeg_simple_progression jSimProgress
902 #define jpeg_suppress_tables jSuppressTables
903 #define jpeg_alloc_quant_table jAlcQTable
904 #define jpeg_alloc_huff_table jAlcHTable
905 #define jpeg_start_compress jStrtCompress
906 #define jpeg_write_scanlines jWrtScanlines
907 #define jpeg_finish_compress jFinCompress
908 #define jpeg_calc_jpeg_dimensions jCjpegDimensions
909 #define jpeg_write_raw_data jWrtRawData
910 #define jpeg_write_marker jWrtMarker
911 #define jpeg_write_m_header jWrtMHeader
912 #define jpeg_write_m_byte jWrtMByte
913 #define jpeg_write_tables jWrtTables
914 #define jpeg_read_header jReadHeader
915 #define jpeg_start_decompress jStrtDecompress
916 #define jpeg_read_scanlines jReadScanlines
917 #define jpeg_finish_decompress jFinDecompress
918 #define jpeg_read_raw_data jReadRawData
919 #define jpeg_has_multiple_scans jHasMultScn
920 #define jpeg_start_output jStrtOutput
921 #define jpeg_finish_output jFinOutput
922 #define jpeg_input_complete jInComplete
923 #define jpeg_new_colormap jNewCMap
924 #define jpeg_consume_input jConsumeInput
925 #define jpeg_core_output_dimensions jCoreDimensions
926 #define jpeg_calc_output_dimensions jCalcDimensions
927 #define jpeg_save_markers jSaveMarkers
928 #define jpeg_set_marker_processor jSetMarker
929 #define jpeg_read_coefficients jReadCoefs
930 #define jpeg_write_coefficients jWrtCoefs
931 #define jpeg_copy_critical_parameters jCopyCrit
932 #define jpeg_abort_compress jAbrtCompress
933 #define jpeg_abort_decompress jAbrtDecompress
934 #define jpeg_abort jAbort
935 #define jpeg_destroy jDestroy
936 #define jpeg_resync_to_restart jResyncRestart
937 #endif /* NEED_SHORT_EXTERNAL_NAMES */
940 /* Default error-management setup */
941 EXTERN(struct jpeg_error_mgr
*) jpeg_std_error
942 JPP((struct jpeg_error_mgr
* err
));
944 /* Initialization of JPEG compression objects.
945 * jpeg_create_compress() and jpeg_create_decompress() are the exported
946 * names that applications should call. These expand to calls on
947 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
948 * passed for version mismatch checking.
949 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
951 #define jpeg_create_compress(cinfo) \
952 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
953 (size_t) sizeof(struct jpeg_compress_struct))
954 #define jpeg_create_decompress(cinfo) \
955 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
956 (size_t) sizeof(struct jpeg_decompress_struct))
957 EXTERN(void) jpeg_CreateCompress
JPP((j_compress_ptr cinfo
,
958 int version
, size_t structsize
));
959 EXTERN(void) jpeg_CreateDecompress
JPP((j_decompress_ptr cinfo
,
960 int version
, size_t structsize
));
961 /* Destruction of JPEG compression objects */
962 EXTERN(void) jpeg_destroy_compress
JPP((j_compress_ptr cinfo
));
963 EXTERN(void) jpeg_destroy_decompress
JPP((j_decompress_ptr cinfo
));
965 /* Standard data source and destination managers: stdio streams. */
966 /* Caller is responsible for opening the file before and closing after. */
967 EXTERN(void) jpeg_stdio_dest
JPP((j_compress_ptr cinfo
, FILE * outfile
));
968 EXTERN(void) jpeg_stdio_src
JPP((j_decompress_ptr cinfo
, FILE * infile
));
970 /* Data source and destination managers: memory buffers. */
971 EXTERN(void) jpeg_mem_dest
JPP((j_compress_ptr cinfo
,
972 unsigned char ** outbuffer
,
973 unsigned long * outsize
));
974 EXTERN(void) jpeg_mem_src
JPP((j_decompress_ptr cinfo
,
975 unsigned char * inbuffer
,
976 unsigned long insize
));
978 /* Default parameter setup for compression */
979 EXTERN(void) jpeg_set_defaults
JPP((j_compress_ptr cinfo
));
980 /* Compression parameter setup aids */
981 EXTERN(void) jpeg_set_colorspace
JPP((j_compress_ptr cinfo
,
982 J_COLOR_SPACE colorspace
));
983 EXTERN(void) jpeg_default_colorspace
JPP((j_compress_ptr cinfo
));
984 EXTERN(void) jpeg_set_quality
JPP((j_compress_ptr cinfo
, int quality
,
985 boolean force_baseline
));
986 EXTERN(void) jpeg_set_linear_quality
JPP((j_compress_ptr cinfo
,
988 boolean force_baseline
));
989 EXTERN(void) jpeg_default_qtables
JPP((j_compress_ptr cinfo
,
990 boolean force_baseline
));
991 EXTERN(void) jpeg_add_quant_table
JPP((j_compress_ptr cinfo
, int which_tbl
,
992 const unsigned int *basic_table
,
994 boolean force_baseline
));
995 EXTERN(int) jpeg_quality_scaling
JPP((int quality
));
996 EXTERN(void) jpeg_simple_progression
JPP((j_compress_ptr cinfo
));
997 EXTERN(void) jpeg_suppress_tables
JPP((j_compress_ptr cinfo
,
999 EXTERN(JQUANT_TBL
*) jpeg_alloc_quant_table
JPP((j_common_ptr cinfo
));
1000 EXTERN(JHUFF_TBL
*) jpeg_alloc_huff_table
JPP((j_common_ptr cinfo
));
1002 /* Main entry points for compression */
1003 EXTERN(void) jpeg_start_compress
JPP((j_compress_ptr cinfo
,
1004 boolean write_all_tables
));
1005 EXTERN(JDIMENSION
) jpeg_write_scanlines
JPP((j_compress_ptr cinfo
,
1006 JSAMPARRAY scanlines
,
1007 JDIMENSION num_lines
));
1008 EXTERN(void) jpeg_finish_compress
JPP((j_compress_ptr cinfo
));
1010 /* Precalculate JPEG dimensions for current compression parameters. */
1011 EXTERN(void) jpeg_calc_jpeg_dimensions
JPP((j_compress_ptr cinfo
));
1013 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
1014 EXTERN(JDIMENSION
) jpeg_write_raw_data
JPP((j_compress_ptr cinfo
,
1016 JDIMENSION num_lines
));
1018 /* Write a special marker. See libjpeg.txt concerning safe usage. */
1019 EXTERN(void) jpeg_write_marker
1020 JPP((j_compress_ptr cinfo
, int marker
,
1021 const JOCTET
* dataptr
, unsigned int datalen
));
1022 /* Same, but piecemeal. */
1023 EXTERN(void) jpeg_write_m_header
1024 JPP((j_compress_ptr cinfo
, int marker
, unsigned int datalen
));
1025 EXTERN(void) jpeg_write_m_byte
1026 JPP((j_compress_ptr cinfo
, int val
));
1028 /* Alternate compression function: just write an abbreviated table file */
1029 EXTERN(void) jpeg_write_tables
JPP((j_compress_ptr cinfo
));
1031 /* Decompression startup: read start of JPEG datastream to see what's there */
1032 EXTERN(int) jpeg_read_header
JPP((j_decompress_ptr cinfo
,
1033 boolean require_image
));
1034 /* Return value is one of: */
1035 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
1036 #define JPEG_HEADER_OK 1 /* Found valid image datastream */
1037 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
1038 /* If you pass require_image = TRUE (normal case), you need not check for
1039 * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
1040 * JPEG_SUSPENDED is only possible if you use a data source module that can
1041 * give a suspension return (the stdio source module doesn't).
1044 /* Main entry points for decompression */
1045 EXTERN(boolean
) jpeg_start_decompress
JPP((j_decompress_ptr cinfo
));
1046 EXTERN(JDIMENSION
) jpeg_read_scanlines
JPP((j_decompress_ptr cinfo
,
1047 JSAMPARRAY scanlines
,
1048 JDIMENSION max_lines
));
1049 EXTERN(boolean
) jpeg_finish_decompress
JPP((j_decompress_ptr cinfo
));
1051 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
1052 EXTERN(JDIMENSION
) jpeg_read_raw_data
JPP((j_decompress_ptr cinfo
,
1054 JDIMENSION max_lines
));
1056 /* Additional entry points for buffered-image mode. */
1057 EXTERN(boolean
) jpeg_has_multiple_scans
JPP((j_decompress_ptr cinfo
));
1058 EXTERN(boolean
) jpeg_start_output
JPP((j_decompress_ptr cinfo
,
1060 EXTERN(boolean
) jpeg_finish_output
JPP((j_decompress_ptr cinfo
));
1061 EXTERN(boolean
) jpeg_input_complete
JPP((j_decompress_ptr cinfo
));
1062 EXTERN(void) jpeg_new_colormap
JPP((j_decompress_ptr cinfo
));
1063 EXTERN(int) jpeg_consume_input
JPP((j_decompress_ptr cinfo
));
1064 /* Return value is one of: */
1065 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
1066 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */
1067 #define JPEG_REACHED_EOI 2 /* Reached end of image */
1068 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
1069 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
1071 /* Precalculate output dimensions for current decompression parameters. */
1072 EXTERN(void) jpeg_core_output_dimensions
JPP((j_decompress_ptr cinfo
));
1073 EXTERN(void) jpeg_calc_output_dimensions
JPP((j_decompress_ptr cinfo
));
1075 /* Control saving of COM and APPn markers into marker_list. */
1076 EXTERN(void) jpeg_save_markers
1077 JPP((j_decompress_ptr cinfo
, int marker_code
,
1078 unsigned int length_limit
));
1080 /* Install a special processing method for COM or APPn markers. */
1081 EXTERN(void) jpeg_set_marker_processor
1082 JPP((j_decompress_ptr cinfo
, int marker_code
,
1083 jpeg_marker_parser_method routine
));
1085 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
1086 EXTERN(jvirt_barray_ptr
*) jpeg_read_coefficients
JPP((j_decompress_ptr cinfo
));
1087 EXTERN(void) jpeg_write_coefficients
JPP((j_compress_ptr cinfo
,
1088 jvirt_barray_ptr
* coef_arrays
));
1089 EXTERN(void) jpeg_copy_critical_parameters
JPP((j_decompress_ptr srcinfo
,
1090 j_compress_ptr dstinfo
));
1092 /* If you choose to abort compression or decompression before completing
1093 * jpeg_finish_(de)compress, then you need to clean up to release memory,
1094 * temporary files, etc. You can just call jpeg_destroy_(de)compress
1095 * if you're done with the JPEG object, but if you want to clean it up and
1096 * reuse it, call this:
1098 EXTERN(void) jpeg_abort_compress
JPP((j_compress_ptr cinfo
));
1099 EXTERN(void) jpeg_abort_decompress
JPP((j_decompress_ptr cinfo
));
1101 /* Generic versions of jpeg_abort and jpeg_destroy that work on either
1102 * flavor of JPEG object. These may be more convenient in some places.
1104 EXTERN(void) jpeg_abort
JPP((j_common_ptr cinfo
));
1105 EXTERN(void) jpeg_destroy
JPP((j_common_ptr cinfo
));
1107 /* Default restart-marker-resync procedure for use by data source modules */
1108 EXTERN(boolean
) jpeg_resync_to_restart
JPP((j_decompress_ptr cinfo
,
1112 /* These marker codes are exported since applications and data source modules
1113 * are likely to want to use them.
1116 #define JPEG_RST0 0xD0 /* RST0 marker code */
1117 #define JPEG_EOI 0xD9 /* EOI marker code */
1118 #define JPEG_APP0 0xE0 /* APP0 marker code */
1119 #define JPEG_COM 0xFE /* COM marker code */
1122 /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1123 * for structure definitions that are never filled in, keep it quiet by
1124 * supplying dummy definitions for the various substructures.
1127 #ifdef INCOMPLETE_TYPES_BROKEN
1128 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
1129 struct jvirt_sarray_control
{ long dummy
; };
1130 struct jvirt_barray_control
{ long dummy
; };
1131 struct jpeg_comp_master
{ long dummy
; };
1132 struct jpeg_c_main_controller
{ long dummy
; };
1133 struct jpeg_c_prep_controller
{ long dummy
; };
1134 struct jpeg_c_coef_controller
{ long dummy
; };
1135 struct jpeg_marker_writer
{ long dummy
; };
1136 struct jpeg_color_converter
{ long dummy
; };
1137 struct jpeg_downsampler
{ long dummy
; };
1138 struct jpeg_forward_dct
{ long dummy
; };
1139 struct jpeg_entropy_encoder
{ long dummy
; };
1140 struct jpeg_decomp_master
{ long dummy
; };
1141 struct jpeg_d_main_controller
{ long dummy
; };
1142 struct jpeg_d_coef_controller
{ long dummy
; };
1143 struct jpeg_d_post_controller
{ long dummy
; };
1144 struct jpeg_input_controller
{ long dummy
; };
1145 struct jpeg_marker_reader
{ long dummy
; };
1146 struct jpeg_entropy_decoder
{ long dummy
; };
1147 struct jpeg_inverse_dct
{ long dummy
; };
1148 struct jpeg_upsampler
{ long dummy
; };
1149 struct jpeg_color_deconverter
{ long dummy
; };
1150 struct jpeg_color_quantizer
{ long dummy
; };
1151 #endif /* JPEG_INTERNALS */
1152 #endif /* INCOMPLETE_TYPES_BROKEN */
1156 * The JPEG library modules define JPEG_INTERNALS before including this file.
1157 * The internal structure declarations are read only when that is true.
1158 * Applications using the library should not include jpegint.h, but may wish
1159 * to include jerror.h.
1162 #ifdef JPEG_INTERNALS
1163 #include "jpegint.h" /* fetch private declarations */
1164 #include "jerror.h" /* fetch error codes too */
1168 #ifndef DONT_USE_EXTERN_C
1173 #endif /* JPEGLIB_H */