4 * Copyright (C) 1991-1998, Thomas G. Lane.
5 * Modified 2002-2022 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 6
45 /* Various constants determining the sizes of things.
46 * All of these are specified by the JPEG standard,
47 * so don't change them 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 =
161 * ceil(image_width * Hi/Hmax * DCT_h_scaled_size/block_size)
162 * and similarly for height.
164 JDIMENSION downsampled_width
; /* actual width in samples */
165 JDIMENSION downsampled_height
; /* actual height in samples */
166 /* For decompression, in cases where some of the components will be
167 * ignored (eg grayscale output from YCbCr image), we can skip most
168 * computations for the unused components.
169 * For compression, some of the components will need further quantization
170 * scale by factor of 2 after DCT (eg BG_YCC output from normal RGB input).
171 * The field is first set TRUE for decompression, FALSE for compression
172 * in initial_setup, and then adapted in color conversion setup.
174 boolean component_needed
;
176 /* These values are computed before starting a scan of the component. */
177 /* The decompressor output side may not use these variables. */
178 int MCU_width
; /* number of blocks per MCU, horizontally */
179 int MCU_height
; /* number of blocks per MCU, vertically */
180 int MCU_blocks
; /* MCU_width * MCU_height */
181 int MCU_sample_width
; /* MCU width in samples: MCU_width * DCT_h_scaled_size */
182 int last_col_width
; /* # of non-dummy blocks across in last MCU */
183 int last_row_height
; /* # of non-dummy blocks down in last MCU */
185 /* Saved quantization table for component; NULL if none yet saved.
186 * See jdinput.c comments about the need for this information.
187 * This field is currently used only for decompression.
189 JQUANT_TBL
* quant_table
;
191 /* Private per-component storage for DCT or IDCT subsystem. */
193 } jpeg_component_info
;
196 /* The script for encoding a multiple-scan file is an array of these: */
199 int comps_in_scan
; /* number of components encoded in this scan */
200 int component_index
[MAX_COMPS_IN_SCAN
]; /* their SOF/comp_info[] indexes */
201 int Ss
, Se
; /* progressive JPEG spectral selection parms */
202 int Ah
, Al
; /* progressive JPEG successive approx. parms */
205 /* The decompressor can save APPn and COM markers in a list of these: */
207 typedef struct jpeg_marker_struct FAR
* jpeg_saved_marker_ptr
;
209 struct jpeg_marker_struct
{
210 jpeg_saved_marker_ptr next
; /* next in list, or NULL */
211 UINT8 marker
; /* marker code: JPEG_COM, or JPEG_APP0+n */
212 unsigned int original_length
; /* # bytes of data in the file */
213 unsigned int data_length
; /* # bytes of data saved at data[] */
214 JOCTET FAR
* data
; /* the data contained in the marker */
215 /* the marker length word is not counted in data_length or original_length */
218 /* Known color spaces. */
221 JCS_UNKNOWN
, /* error/unspecified */
222 JCS_GRAYSCALE
, /* monochrome */
223 JCS_RGB
, /* red/green/blue, standard RGB (sRGB) */
224 JCS_YCbCr
, /* Y/Cb/Cr (also known as YUV), standard YCC */
225 JCS_CMYK
, /* C/M/Y/K */
226 JCS_YCCK
, /* Y/Cb/Cr/K */
227 JCS_BG_RGB
, /* big gamut red/green/blue, bg-sRGB */
228 JCS_BG_YCC
/* big gamut Y/Cb/Cr, bg-sYCC */
231 /* Supported color transforms. */
235 JCT_SUBTRACT_GREEN
= 1
238 /* DCT/IDCT algorithm options. */
241 JDCT_ISLOW
, /* slow but accurate integer algorithm */
242 JDCT_IFAST
, /* faster, less accurate integer method */
243 JDCT_FLOAT
/* floating-point: accurate, fast on fast HW */
246 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
247 #define JDCT_DEFAULT JDCT_ISLOW
249 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
250 #define JDCT_FASTEST JDCT_IFAST
253 /* Dithering options for decompression. */
256 JDITHER_NONE
, /* no dithering */
257 JDITHER_ORDERED
, /* simple ordered dither */
258 JDITHER_FS
/* Floyd-Steinberg error diffusion dither */
262 /* Common fields between JPEG compression and decompression master structs. */
264 #define jpeg_common_fields \
265 struct jpeg_error_mgr * err; /* Error handler module */\
266 struct jpeg_memory_mgr * mem; /* Memory manager module */\
267 struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
268 void * client_data; /* Available for use by application */\
269 boolean is_decompressor; /* So common code can tell which is which */\
270 int global_state /* For checking call sequence validity */
272 /* Routines that are to be used by both halves of the library are declared
273 * to receive a pointer to this structure. There are no actual instances of
274 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
276 struct jpeg_common_struct
{
277 jpeg_common_fields
; /* Fields common to both master struct types */
278 /* Additional fields follow in an actual jpeg_compress_struct or
279 * jpeg_decompress_struct. All three structs must agree on these
280 * initial fields! (This would be a lot cleaner in C++.)
284 typedef struct jpeg_common_struct
* j_common_ptr
;
285 typedef struct jpeg_compress_struct
* j_compress_ptr
;
286 typedef struct jpeg_decompress_struct
* j_decompress_ptr
;
289 /* Master record for a compression instance */
291 struct jpeg_compress_struct
{
292 jpeg_common_fields
; /* Fields shared with jpeg_decompress_struct */
294 /* Destination for compressed data */
295 struct jpeg_destination_mgr
* dest
;
297 /* Description of source image --- these fields must be filled in by
298 * outer application before starting compression. in_color_space must
299 * be correct before you can even call jpeg_set_defaults().
302 JDIMENSION image_width
; /* input image width */
303 JDIMENSION image_height
; /* input image height */
304 int input_components
; /* # of color components in input image */
305 J_COLOR_SPACE in_color_space
; /* colorspace of input image */
307 double input_gamma
; /* image gamma of input image */
309 /* Compression parameters --- these fields must be set before calling
310 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
311 * initialize everything to reasonable defaults, then changing anything
312 * the application specifically wants to change. That way you won't get
313 * burnt when new parameters are added. Also note that there are several
314 * helper routines to simplify changing parameters.
317 unsigned int scale_num
, scale_denom
; /* fraction by which to scale image */
319 JDIMENSION jpeg_width
; /* scaled JPEG image width */
320 JDIMENSION jpeg_height
; /* scaled JPEG image height */
321 /* Dimensions of actual JPEG image that will be written to file,
322 * derived from input dimensions by scaling factors above.
323 * These fields are computed by jpeg_start_compress().
324 * You can also use jpeg_calc_jpeg_dimensions() to determine these values
325 * in advance of calling jpeg_start_compress().
328 int data_precision
; /* bits of precision in image data */
330 int num_components
; /* # of color components in JPEG image */
331 J_COLOR_SPACE jpeg_color_space
; /* colorspace of JPEG image */
333 jpeg_component_info
* comp_info
;
334 /* comp_info[i] describes component that appears i'th in SOF */
336 JQUANT_TBL
* quant_tbl_ptrs
[NUM_QUANT_TBLS
];
337 int q_scale_factor
[NUM_QUANT_TBLS
];
338 /* ptrs to coefficient quantization tables, or NULL if not defined,
339 * and corresponding scale factors (percentage, initialized 100).
342 JHUFF_TBL
* dc_huff_tbl_ptrs
[NUM_HUFF_TBLS
];
343 JHUFF_TBL
* ac_huff_tbl_ptrs
[NUM_HUFF_TBLS
];
344 /* ptrs to Huffman coding tables, or NULL if not defined */
346 UINT8 arith_dc_L
[NUM_ARITH_TBLS
]; /* L values for DC arith-coding tables */
347 UINT8 arith_dc_U
[NUM_ARITH_TBLS
]; /* U values for DC arith-coding tables */
348 UINT8 arith_ac_K
[NUM_ARITH_TBLS
]; /* Kx values for AC arith-coding tables */
350 int num_scans
; /* # of entries in scan_info array */
351 const jpeg_scan_info
* scan_info
; /* script for multi-scan file, or NULL */
352 /* The default value of scan_info is NULL, which causes a single-scan
353 * sequential JPEG file to be emitted. To create a multi-scan file,
354 * set num_scans and scan_info to point to an array of scan definitions.
357 boolean raw_data_in
; /* TRUE=caller supplies downsampled data */
358 boolean arith_code
; /* TRUE=arithmetic coding, FALSE=Huffman */
359 boolean optimize_coding
; /* TRUE=optimize entropy encoding parms */
360 boolean CCIR601_sampling
; /* TRUE=first samples are cosited */
361 boolean do_fancy_downsampling
; /* TRUE=apply fancy downsampling */
362 int smoothing_factor
; /* 1..100, or 0 for no input smoothing */
363 J_DCT_METHOD dct_method
; /* DCT algorithm selector */
365 /* The restart interval can be specified in absolute MCUs by setting
366 * restart_interval, or in MCU rows by setting restart_in_rows
367 * (in which case the correct restart_interval will be figured
370 unsigned int restart_interval
; /* MCUs per restart, or 0 for no restart */
371 int restart_in_rows
; /* if > 0, MCU rows per restart interval */
373 /* Parameters controlling emission of special markers. */
375 boolean write_JFIF_header
; /* should a JFIF marker be written? */
376 UINT8 JFIF_major_version
; /* What to write for the JFIF version number */
377 UINT8 JFIF_minor_version
;
378 /* These three values are not used by the JPEG code, merely copied */
379 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
380 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
381 /* ratio is defined by X_density/Y_density even when density_unit=0. */
382 UINT8 density_unit
; /* JFIF code for pixel size units */
383 UINT16 X_density
; /* Horizontal pixel density */
384 UINT16 Y_density
; /* Vertical pixel density */
385 boolean write_Adobe_marker
; /* should an Adobe marker be written? */
387 J_COLOR_TRANSFORM color_transform
;
388 /* Color transform identifier, writes LSE marker if nonzero */
390 /* State variable: index of next scanline to be written to
391 * jpeg_write_scanlines(). Application may use this to control its
392 * processing loop, e.g., "while (next_scanline < image_height)".
395 JDIMENSION next_scanline
; /* 0 .. image_height-1 */
397 /* Remaining fields are known throughout compressor, but generally
398 * should not be touched by a surrounding application.
402 * These fields are computed during compression startup
404 boolean progressive_mode
; /* TRUE if scan script uses progressive mode */
405 int max_h_samp_factor
; /* largest h_samp_factor */
406 int max_v_samp_factor
; /* largest v_samp_factor */
408 int min_DCT_h_scaled_size
; /* smallest DCT_h_scaled_size of any component */
409 int min_DCT_v_scaled_size
; /* smallest DCT_v_scaled_size of any component */
411 JDIMENSION total_iMCU_rows
; /* # of iMCU rows to be input to coef ctlr */
412 /* The coefficient controller receives data in units of MCU rows as defined
413 * for fully interleaved scans (whether the JPEG file is interleaved or not).
414 * There are v_samp_factor * DCT_v_scaled_size sample rows of each component
415 * in an "iMCU" (interleaved MCU) row.
419 * These fields are valid during any one scan.
420 * They describe the components and MCUs actually appearing in the scan.
422 int comps_in_scan
; /* # of JPEG components in this scan */
423 jpeg_component_info
* cur_comp_info
[MAX_COMPS_IN_SCAN
];
424 /* *cur_comp_info[i] describes component that appears i'th in SOS */
426 JDIMENSION MCUs_per_row
; /* # of MCUs across the image */
427 JDIMENSION MCU_rows_in_scan
; /* # of MCU rows in the image */
429 int blocks_in_MCU
; /* # of DCT blocks per MCU */
430 int MCU_membership
[C_MAX_BLOCKS_IN_MCU
];
431 /* MCU_membership[i] is index in cur_comp_info of component owning */
432 /* i'th block in an MCU */
434 int Ss
, Se
, Ah
, Al
; /* progressive JPEG parameters for scan */
436 int block_size
; /* the basic DCT block size: 1..16 */
437 const int * natural_order
; /* natural-order position array */
438 int lim_Se
; /* min( Se, DCTSIZE2-1 ) */
441 * Links to compression subobjects (methods and private variables of modules)
443 struct jpeg_comp_master
* master
;
444 struct jpeg_c_main_controller
* main
;
445 struct jpeg_c_prep_controller
* prep
;
446 struct jpeg_c_coef_controller
* coef
;
447 struct jpeg_marker_writer
* marker
;
448 struct jpeg_color_converter
* cconvert
;
449 struct jpeg_downsampler
* downsample
;
450 struct jpeg_forward_dct
* fdct
;
451 struct jpeg_entropy_encoder
* entropy
;
452 jpeg_scan_info
* script_space
; /* workspace for jpeg_simple_progression */
453 int script_space_size
;
457 /* Master record for a decompression instance */
459 struct jpeg_decompress_struct
{
460 jpeg_common_fields
; /* Fields shared with jpeg_compress_struct */
462 /* Source of compressed data */
463 struct jpeg_source_mgr
* src
;
465 /* Basic description of image --- filled in by jpeg_read_header(). */
466 /* Application may inspect these values to decide how to process image. */
468 JDIMENSION image_width
; /* nominal image width (from SOF marker) */
469 JDIMENSION image_height
; /* nominal image height */
470 int num_components
; /* # of color components in JPEG image */
471 J_COLOR_SPACE jpeg_color_space
; /* colorspace of JPEG image */
473 /* Decompression processing parameters --- these fields must be set before
474 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
475 * them to default values.
478 J_COLOR_SPACE out_color_space
; /* colorspace for output */
480 unsigned int scale_num
, scale_denom
; /* fraction by which to scale image */
482 double output_gamma
; /* image gamma wanted in output */
484 boolean buffered_image
; /* TRUE=multiple output passes */
485 boolean raw_data_out
; /* TRUE=downsampled data wanted */
487 J_DCT_METHOD dct_method
; /* IDCT algorithm selector */
488 boolean do_fancy_upsampling
; /* TRUE=apply fancy upsampling */
489 boolean do_block_smoothing
; /* TRUE=apply interblock smoothing */
491 boolean quantize_colors
; /* TRUE=colormapped output wanted */
492 /* the following are ignored if not quantize_colors: */
493 J_DITHER_MODE dither_mode
; /* type of color dithering to use */
494 boolean two_pass_quantize
; /* TRUE=use two-pass color quantization */
495 int desired_number_of_colors
; /* max # colors to use in created colormap */
496 /* these are significant only in buffered-image mode: */
497 boolean enable_1pass_quant
; /* enable future use of 1-pass quantizer */
498 boolean enable_external_quant
;/* enable future use of external colormap */
499 boolean enable_2pass_quant
; /* enable future use of 2-pass quantizer */
501 /* Description of actual output image that will be returned to application.
502 * These fields are computed by jpeg_start_decompress().
503 * You can also use jpeg_calc_output_dimensions() to determine these values
504 * in advance of calling jpeg_start_decompress().
507 JDIMENSION output_width
; /* scaled image width */
508 JDIMENSION output_height
; /* scaled image height */
509 int out_color_components
; /* # of color components in out_color_space */
510 int output_components
; /* # of color components returned */
511 /* output_components is 1 (a colormap index) when quantizing colors;
512 * otherwise it equals out_color_components.
514 int rec_outbuf_height
; /* min recommended height of scanline buffer */
515 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
516 * high, space and time will be wasted due to unnecessary data copying.
517 * Usually rec_outbuf_height will be 1 or 2, at most 4.
520 /* When quantizing colors, the output colormap is described by these fields.
521 * The application can supply a colormap by setting colormap non-NULL before
522 * calling jpeg_start_decompress; otherwise a colormap is created during
523 * jpeg_start_decompress or jpeg_start_output.
524 * The map has out_color_components rows and actual_number_of_colors columns.
526 int actual_number_of_colors
; /* number of entries in use */
527 JSAMPARRAY colormap
; /* The color map as a 2-D pixel array */
529 /* State variables: these variables indicate the progress of decompression.
530 * The application may examine these but must not modify them.
533 /* Row index of next scanline to be read from jpeg_read_scanlines().
534 * Application may use this to control its processing loop, e.g.,
535 * "while (output_scanline < output_height)".
537 JDIMENSION output_scanline
; /* 0 .. output_height-1 */
539 /* Current input scan number and number of iMCU rows completed in scan.
540 * These indicate the progress of the decompressor input side.
542 int input_scan_number
; /* Number of SOS markers seen so far */
543 JDIMENSION input_iMCU_row
; /* Number of iMCU rows completed */
545 /* The "output scan number" is the notional scan being displayed by the
546 * output side. The decompressor will not allow output scan/row number
547 * to get ahead of input scan/row, but it can fall arbitrarily far behind.
549 int output_scan_number
; /* Nominal scan number being displayed */
550 JDIMENSION output_iMCU_row
; /* Number of iMCU rows read */
552 /* Current progression status. coef_bits[c][i] indicates the precision
553 * with which component c's DCT coefficient i (in zigzag order) is known.
554 * It is -1 when no data has yet been received, otherwise it is the point
555 * transform (shift) value for the most recent scan of the coefficient
556 * (thus, 0 at completion of the progression).
557 * This pointer is NULL when reading a non-progressive file.
559 int (*coef_bits
)[DCTSIZE2
]; /* -1 or current Al value for each coef */
561 /* Internal JPEG parameters --- the application usually need not look at
562 * these fields. Note that the decompressor output side may not use
563 * any parameters that can change between scans.
566 /* Quantization and Huffman tables are carried forward across input
567 * datastreams when processing abbreviated JPEG datastreams.
570 JQUANT_TBL
* quant_tbl_ptrs
[NUM_QUANT_TBLS
];
571 /* ptrs to coefficient quantization tables, or NULL if not defined */
573 JHUFF_TBL
* dc_huff_tbl_ptrs
[NUM_HUFF_TBLS
];
574 JHUFF_TBL
* ac_huff_tbl_ptrs
[NUM_HUFF_TBLS
];
575 /* ptrs to Huffman coding tables, or NULL if not defined */
577 /* These parameters are never carried across datastreams, since they
578 * are given in SOF/SOS markers or defined to be reset by SOI.
581 int data_precision
; /* bits of precision in image data */
583 jpeg_component_info
* comp_info
;
584 /* comp_info[i] describes component that appears i'th in SOF */
586 boolean is_baseline
; /* TRUE if Baseline SOF0 encountered */
587 boolean progressive_mode
; /* TRUE if SOFn specifies progressive mode */
588 boolean arith_code
; /* TRUE=arithmetic coding, FALSE=Huffman */
590 UINT8 arith_dc_L
[NUM_ARITH_TBLS
]; /* L values for DC arith-coding tables */
591 UINT8 arith_dc_U
[NUM_ARITH_TBLS
]; /* U values for DC arith-coding tables */
592 UINT8 arith_ac_K
[NUM_ARITH_TBLS
]; /* Kx values for AC arith-coding tables */
594 unsigned int restart_interval
; /* MCUs per restart interval, or 0 for no restart */
596 /* These fields record data obtained from optional markers recognized by
599 boolean saw_JFIF_marker
; /* TRUE iff a JFIF APP0 marker was found */
600 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
601 UINT8 JFIF_major_version
; /* JFIF version number */
602 UINT8 JFIF_minor_version
;
603 UINT8 density_unit
; /* JFIF code for pixel size units */
604 UINT16 X_density
; /* Horizontal pixel density */
605 UINT16 Y_density
; /* Vertical pixel density */
606 boolean saw_Adobe_marker
; /* TRUE iff an Adobe APP14 marker was found */
607 UINT8 Adobe_transform
; /* Color transform code from Adobe marker */
609 J_COLOR_TRANSFORM color_transform
;
610 /* Color transform identifier derived from LSE marker, otherwise zero */
612 boolean CCIR601_sampling
; /* TRUE=first samples are cosited */
614 /* Aside from the specific data retained from APPn markers known to the
615 * library, the uninterpreted contents of any or all APPn and COM markers
616 * can be saved in a list for examination by the application.
618 jpeg_saved_marker_ptr marker_list
; /* Head of list of saved markers */
620 /* Remaining fields are known throughout decompressor, but generally
621 * should not be touched by a surrounding application.
625 * These fields are computed during decompression startup
627 int max_h_samp_factor
; /* largest h_samp_factor */
628 int max_v_samp_factor
; /* largest v_samp_factor */
630 int min_DCT_h_scaled_size
; /* smallest DCT_h_scaled_size of any component */
631 int min_DCT_v_scaled_size
; /* smallest DCT_v_scaled_size of any component */
633 JDIMENSION total_iMCU_rows
; /* # of iMCU rows in image */
634 /* The coefficient controller's input and output progress is measured in
635 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
636 * in fully interleaved JPEG scans, but are used whether the scan is
637 * interleaved or not. We define an iMCU row as v_samp_factor DCT block
638 * rows of each component. Therefore, the IDCT output contains
639 * v_samp_factor * DCT_v_scaled_size sample rows of a component per iMCU row.
642 JSAMPLE
* sample_range_limit
; /* table for fast range-limiting */
645 * These fields are valid during any one scan.
646 * They describe the components and MCUs actually appearing in the scan.
647 * Note that the decompressor output side must not use these fields.
649 int comps_in_scan
; /* # of JPEG components in this scan */
650 jpeg_component_info
* cur_comp_info
[MAX_COMPS_IN_SCAN
];
651 /* *cur_comp_info[i] describes component that appears i'th in SOS */
653 JDIMENSION MCUs_per_row
; /* # of MCUs across the image */
654 JDIMENSION MCU_rows_in_scan
; /* # of MCU rows in the image */
656 int blocks_in_MCU
; /* # of DCT blocks per MCU */
657 int MCU_membership
[D_MAX_BLOCKS_IN_MCU
];
658 /* MCU_membership[i] is index in cur_comp_info of component owning */
659 /* i'th block in an MCU */
661 int Ss
, Se
, Ah
, Al
; /* progressive JPEG parameters for scan */
663 /* These fields are derived from Se of first SOS marker.
665 int block_size
; /* the basic DCT block size: 1..16 */
666 const int * natural_order
; /* natural-order position array for entropy decode */
667 int lim_Se
; /* min( Se, DCTSIZE2-1 ) for entropy decode */
669 /* This field is shared between entropy decoder and marker parser.
670 * It is either zero or the code of a JPEG marker that has been
671 * read from the data source, but has not yet been processed.
676 * Links to decompression subobjects (methods, private variables of modules)
678 struct jpeg_decomp_master
* master
;
679 struct jpeg_d_main_controller
* main
;
680 struct jpeg_d_coef_controller
* coef
;
681 struct jpeg_d_post_controller
* post
;
682 struct jpeg_input_controller
* inputctl
;
683 struct jpeg_marker_reader
* marker
;
684 struct jpeg_entropy_decoder
* entropy
;
685 struct jpeg_inverse_dct
* idct
;
686 struct jpeg_upsampler
* upsample
;
687 struct jpeg_color_deconverter
* cconvert
;
688 struct jpeg_color_quantizer
* cquantize
;
692 /* "Object" declarations for JPEG modules that may be supplied or called
693 * directly by the surrounding application.
694 * As with all objects in the JPEG library, these structs only define the
695 * publicly visible methods and state variables of a module. Additional
696 * private fields may exist after the public ones.
700 /* Error handler object */
702 struct jpeg_error_mgr
{
703 /* Error exit handler: does not return to caller */
704 JMETHOD(noreturn_t
, error_exit
, (j_common_ptr cinfo
));
705 /* Conditionally emit a trace or warning message */
706 JMETHOD(void, emit_message
, (j_common_ptr cinfo
, int msg_level
));
707 /* Routine that actually outputs a trace or error message */
708 JMETHOD(void, output_message
, (j_common_ptr cinfo
));
709 /* Format a message string for the most recent JPEG error or message */
710 JMETHOD(void, format_message
, (j_common_ptr cinfo
, char * buffer
));
711 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
712 /* Reset error state variables at start of a new image */
713 JMETHOD(void, reset_error_mgr
, (j_common_ptr cinfo
));
715 /* The message ID code and any parameters are saved here.
716 * A message can have one string parameter or up to 8 int parameters.
719 #define JMSG_STR_PARM_MAX 80
722 char s
[JMSG_STR_PARM_MAX
];
725 /* Standard state variables for error facility */
727 int trace_level
; /* max msg_level that will be displayed */
729 /* For recoverable corrupt-data errors, we emit a warning message,
730 * but keep going unless emit_message chooses to abort. emit_message
731 * should count warnings in num_warnings. The surrounding application
732 * can check for bad data by seeing if num_warnings is nonzero at the
735 long num_warnings
; /* number of corrupt-data warnings */
737 /* These fields point to the table(s) of error message strings.
738 * An application can change the table pointer to switch to a different
739 * message list (typically, to change the language in which errors are
740 * reported). Some applications may wish to add additional error codes
741 * that will be handled by the JPEG library error mechanism; the second
742 * table pointer is used for this purpose.
744 * First table includes all errors generated by JPEG library itself.
745 * Error code 0 is reserved for a "no such error string" message.
747 const char * const * jpeg_message_table
; /* Library errors */
748 int last_jpeg_message
; /* Table contains strings 0..last_jpeg_message */
749 /* Second table can be added by application (see cjpeg/djpeg for example).
750 * It contains strings numbered first_addon_message..last_addon_message.
752 const char * const * addon_message_table
; /* Non-library errors */
753 int first_addon_message
; /* code for first string in addon table */
754 int last_addon_message
; /* code for last string in addon table */
758 /* Progress monitor object */
760 struct jpeg_progress_mgr
{
761 JMETHOD(void, progress_monitor
, (j_common_ptr cinfo
));
763 long pass_counter
; /* work units completed in this pass */
764 long pass_limit
; /* total number of work units in this pass */
765 int completed_passes
; /* passes completed so far */
766 int total_passes
; /* total number of passes expected */
770 /* Data destination object for compression */
772 struct jpeg_destination_mgr
{
773 JOCTET
* next_output_byte
; /* => next byte to write in buffer */
774 size_t free_in_buffer
; /* # of byte spaces remaining in buffer */
776 JMETHOD(void, init_destination
, (j_compress_ptr cinfo
));
777 JMETHOD(boolean
, empty_output_buffer
, (j_compress_ptr cinfo
));
778 JMETHOD(void, term_destination
, (j_compress_ptr cinfo
));
782 /* Data source object for decompression */
784 struct jpeg_source_mgr
{
785 const JOCTET
* next_input_byte
; /* => next byte to read from buffer */
786 size_t bytes_in_buffer
; /* # of bytes remaining in buffer */
788 JMETHOD(void, init_source
, (j_decompress_ptr cinfo
));
789 JMETHOD(boolean
, fill_input_buffer
, (j_decompress_ptr cinfo
));
790 JMETHOD(void, skip_input_data
, (j_decompress_ptr cinfo
, long num_bytes
));
791 JMETHOD(boolean
, resync_to_restart
, (j_decompress_ptr cinfo
, int desired
));
792 JMETHOD(void, term_source
, (j_decompress_ptr cinfo
));
796 /* Memory manager object.
797 * Allocates "small" objects (a few K total), "large" objects (tens of K),
798 * and "really big" objects (virtual arrays with backing store if needed).
799 * The memory manager does not allow individual objects to be freed; rather,
800 * each created object is assigned to a pool, and whole pools can be freed
801 * at once. This is faster and more convenient than remembering exactly what
802 * to free, especially where malloc()/free() are not too speedy.
803 * NB: alloc routines never return NULL. They exit to error_exit if not
807 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
808 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
809 #define JPOOL_NUMPOOLS 2
811 typedef struct jvirt_sarray_control
* jvirt_sarray_ptr
;
812 typedef struct jvirt_barray_control
* jvirt_barray_ptr
;
815 struct jpeg_memory_mgr
{
816 /* Method pointers */
817 JMETHOD(void *, alloc_small
, (j_common_ptr cinfo
, int pool_id
,
818 size_t sizeofobject
));
819 JMETHOD(void FAR
*, alloc_large
, (j_common_ptr cinfo
, int pool_id
,
820 size_t sizeofobject
));
821 JMETHOD(JSAMPARRAY
, alloc_sarray
, (j_common_ptr cinfo
, int pool_id
,
822 JDIMENSION samplesperrow
,
823 JDIMENSION numrows
));
824 JMETHOD(JBLOCKARRAY
, alloc_barray
, (j_common_ptr cinfo
, int pool_id
,
825 JDIMENSION blocksperrow
,
826 JDIMENSION numrows
));
827 JMETHOD(jvirt_sarray_ptr
, request_virt_sarray
, (j_common_ptr cinfo
,
830 JDIMENSION samplesperrow
,
832 JDIMENSION maxaccess
));
833 JMETHOD(jvirt_barray_ptr
, request_virt_barray
, (j_common_ptr cinfo
,
836 JDIMENSION blocksperrow
,
838 JDIMENSION maxaccess
));
839 JMETHOD(void, realize_virt_arrays
, (j_common_ptr cinfo
));
840 JMETHOD(JSAMPARRAY
, access_virt_sarray
, (j_common_ptr cinfo
,
841 jvirt_sarray_ptr ptr
,
842 JDIMENSION start_row
,
845 JMETHOD(JBLOCKARRAY
, access_virt_barray
, (j_common_ptr cinfo
,
846 jvirt_barray_ptr ptr
,
847 JDIMENSION start_row
,
850 JMETHOD(void, free_pool
, (j_common_ptr cinfo
, int pool_id
));
851 JMETHOD(void, self_destruct
, (j_common_ptr cinfo
));
853 /* Limit on memory allocation for this JPEG object. (Note that this is
854 * merely advisory, not a guaranteed maximum; it only affects the space
855 * used for virtual-array buffers.) May be changed by outer application
856 * after creating the JPEG object.
858 long max_memory_to_use
;
860 /* Maximum allocation request accepted by alloc_large. */
861 long max_alloc_chunk
;
865 /* Routine signature for application-supplied marker processing methods.
866 * Need not pass marker code since it is stored in cinfo->unread_marker.
868 typedef JMETHOD(boolean
, jpeg_marker_parser_method
, (j_decompress_ptr cinfo
));
871 /* Declarations for routines called by application.
872 * The JPP macro hides prototype parameters from compilers that can't cope.
873 * Note JPP requires double parentheses.
876 #ifdef HAVE_PROTOTYPES
877 #define JPP(arglist) arglist
879 #define JPP(arglist) ()
883 /* Short forms of external names for systems with brain-damaged linkers.
884 * We shorten external names to be unique in the first six letters, which
885 * is good enough for all known systems.
886 * (If your compiler itself needs names to be unique in less than 15
887 * characters, you are out of luck. Get a better compiler.)
890 #ifdef NEED_SHORT_EXTERNAL_NAMES
891 #define jpeg_std_error jStdError
892 #define jpeg_CreateCompress jCreaCompress
893 #define jpeg_CreateDecompress jCreaDecompress
894 #define jpeg_destroy_compress jDestCompress
895 #define jpeg_destroy_decompress jDestDecompress
896 #define jpeg_stdio_dest jStdDest
897 #define jpeg_stdio_src jStdSrc
898 #define jpeg_mem_dest jMemDest
899 #define jpeg_mem_src jMemSrc
900 #define jpeg_set_defaults jSetDefaults
901 #define jpeg_set_colorspace jSetColorspace
902 #define jpeg_default_colorspace jDefColorspace
903 #define jpeg_set_quality jSetQuality
904 #define jpeg_set_linear_quality jSetLQuality
905 #define jpeg_default_qtables jDefQTables
906 #define jpeg_add_quant_table jAddQuantTable
907 #define jpeg_quality_scaling jQualityScaling
908 #define jpeg_simple_progression jSimProgress
909 #define jpeg_suppress_tables jSuppressTables
910 #define jpeg_alloc_quant_table jAlcQTable
911 #define jpeg_alloc_huff_table jAlcHTable
912 #define jpeg_std_huff_table jStdHTable
913 #define jpeg_start_compress jStrtCompress
914 #define jpeg_write_scanlines jWrtScanlines
915 #define jpeg_finish_compress jFinCompress
916 #define jpeg_calc_jpeg_dimensions jCjpegDimensions
917 #define jpeg_write_raw_data jWrtRawData
918 #define jpeg_write_marker jWrtMarker
919 #define jpeg_write_m_header jWrtMHeader
920 #define jpeg_write_m_byte jWrtMByte
921 #define jpeg_write_tables jWrtTables
922 #define jpeg_read_header jReadHeader
923 #define jpeg_start_decompress jStrtDecompress
924 #define jpeg_read_scanlines jReadScanlines
925 #define jpeg_finish_decompress jFinDecompress
926 #define jpeg_read_raw_data jReadRawData
927 #define jpeg_has_multiple_scans jHasMultScn
928 #define jpeg_start_output jStrtOutput
929 #define jpeg_finish_output jFinOutput
930 #define jpeg_input_complete jInComplete
931 #define jpeg_new_colormap jNewCMap
932 #define jpeg_consume_input jConsumeInput
933 #define jpeg_core_output_dimensions jCoreDimensions
934 #define jpeg_calc_output_dimensions jCalcDimensions
935 #define jpeg_save_markers jSaveMarkers
936 #define jpeg_set_marker_processor jSetMarker
937 #define jpeg_read_coefficients jReadCoefs
938 #define jpeg_write_coefficients jWrtCoefs
939 #define jpeg_copy_critical_parameters jCopyCrit
940 #define jpeg_abort_compress jAbrtCompress
941 #define jpeg_abort_decompress jAbrtDecompress
942 #define jpeg_abort jAbort
943 #define jpeg_destroy jDestroy
944 #define jpeg_resync_to_restart jResyncRestart
945 #endif /* NEED_SHORT_EXTERNAL_NAMES */
948 /* Default error-management setup */
949 EXTERN(struct jpeg_error_mgr
*) jpeg_std_error
950 JPP((struct jpeg_error_mgr
* err
));
952 /* Initialization of JPEG compression objects.
953 * jpeg_create_compress() and jpeg_create_decompress() are the exported
954 * names that applications should call. These expand to calls on
955 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
956 * passed for version mismatch checking.
957 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
959 #define jpeg_create_compress(cinfo) \
960 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
961 (size_t) sizeof(struct jpeg_compress_struct))
962 #define jpeg_create_decompress(cinfo) \
963 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
964 (size_t) sizeof(struct jpeg_decompress_struct))
965 EXTERN(void) jpeg_CreateCompress
JPP((j_compress_ptr cinfo
,
966 int version
, size_t structsize
));
967 EXTERN(void) jpeg_CreateDecompress
JPP((j_decompress_ptr cinfo
,
968 int version
, size_t structsize
));
969 /* Destruction of JPEG compression objects */
970 EXTERN(void) jpeg_destroy_compress
JPP((j_compress_ptr cinfo
));
971 EXTERN(void) jpeg_destroy_decompress
JPP((j_decompress_ptr cinfo
));
973 /* Standard data source and destination managers: stdio streams. */
974 /* Caller is responsible for opening the file before and closing after. */
975 EXTERN(void) jpeg_stdio_dest
JPP((j_compress_ptr cinfo
, FILE * outfile
));
976 EXTERN(void) jpeg_stdio_src
JPP((j_decompress_ptr cinfo
, FILE * infile
));
978 /* Data source and destination managers: memory buffers. */
979 EXTERN(void) jpeg_mem_dest
JPP((j_compress_ptr cinfo
,
980 unsigned char ** outbuffer
,
982 EXTERN(void) jpeg_mem_src
JPP((j_decompress_ptr cinfo
,
983 const unsigned char * inbuffer
,
986 /* Default parameter setup for compression */
987 EXTERN(void) jpeg_set_defaults
JPP((j_compress_ptr cinfo
));
988 /* Compression parameter setup aids */
989 EXTERN(void) jpeg_set_colorspace
JPP((j_compress_ptr cinfo
,
990 J_COLOR_SPACE colorspace
));
991 EXTERN(void) jpeg_default_colorspace
JPP((j_compress_ptr cinfo
));
992 EXTERN(void) jpeg_set_quality
JPP((j_compress_ptr cinfo
, int quality
,
993 boolean force_baseline
));
994 EXTERN(void) jpeg_set_linear_quality
JPP((j_compress_ptr cinfo
,
996 boolean force_baseline
));
997 EXTERN(void) jpeg_default_qtables
JPP((j_compress_ptr cinfo
,
998 boolean force_baseline
));
999 EXTERN(void) jpeg_add_quant_table
JPP((j_compress_ptr cinfo
, int which_tbl
,
1000 const unsigned int *basic_table
,
1002 boolean force_baseline
));
1003 EXTERN(int) jpeg_quality_scaling
JPP((int quality
));
1004 EXTERN(void) jpeg_simple_progression
JPP((j_compress_ptr cinfo
));
1005 EXTERN(void) jpeg_suppress_tables
JPP((j_compress_ptr cinfo
,
1007 EXTERN(JQUANT_TBL
*) jpeg_alloc_quant_table
JPP((j_common_ptr cinfo
));
1008 EXTERN(JHUFF_TBL
*) jpeg_alloc_huff_table
JPP((j_common_ptr cinfo
));
1009 EXTERN(JHUFF_TBL
*) jpeg_std_huff_table
JPP((j_common_ptr cinfo
,
1010 boolean isDC
, int tblno
));
1012 /* Main entry points for compression */
1013 EXTERN(void) jpeg_start_compress
JPP((j_compress_ptr cinfo
,
1014 boolean write_all_tables
));
1015 EXTERN(JDIMENSION
) jpeg_write_scanlines
JPP((j_compress_ptr cinfo
,
1016 JSAMPARRAY scanlines
,
1017 JDIMENSION num_lines
));
1018 EXTERN(void) jpeg_finish_compress
JPP((j_compress_ptr cinfo
));
1020 /* Precalculate JPEG dimensions for current compression parameters. */
1021 EXTERN(void) jpeg_calc_jpeg_dimensions
JPP((j_compress_ptr cinfo
));
1023 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
1024 EXTERN(JDIMENSION
) jpeg_write_raw_data
JPP((j_compress_ptr cinfo
,
1026 JDIMENSION num_lines
));
1028 /* Write a special marker. See libjpeg.txt concerning safe usage. */
1029 EXTERN(void) jpeg_write_marker
1030 JPP((j_compress_ptr cinfo
, int marker
,
1031 const JOCTET
* dataptr
, unsigned int datalen
));
1032 /* Same, but piecemeal. */
1033 EXTERN(void) jpeg_write_m_header
1034 JPP((j_compress_ptr cinfo
, int marker
, unsigned int datalen
));
1035 EXTERN(void) jpeg_write_m_byte
1036 JPP((j_compress_ptr cinfo
, int val
));
1038 /* Alternate compression function: just write an abbreviated table file */
1039 EXTERN(void) jpeg_write_tables
JPP((j_compress_ptr cinfo
));
1041 /* Decompression startup: read start of JPEG datastream to see what's there */
1042 EXTERN(int) jpeg_read_header
JPP((j_decompress_ptr cinfo
,
1043 boolean require_image
));
1044 /* Return value is one of: */
1045 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
1046 #define JPEG_HEADER_OK 1 /* Found valid image datastream */
1047 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
1048 /* If you pass require_image = TRUE (normal case), you need not check for
1049 * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
1050 * JPEG_SUSPENDED is only possible if you use a data source module that can
1051 * give a suspension return (the stdio source module doesn't).
1054 /* Main entry points for decompression */
1055 EXTERN(boolean
) jpeg_start_decompress
JPP((j_decompress_ptr cinfo
));
1056 EXTERN(JDIMENSION
) jpeg_read_scanlines
JPP((j_decompress_ptr cinfo
,
1057 JSAMPARRAY scanlines
,
1058 JDIMENSION max_lines
));
1059 EXTERN(boolean
) jpeg_finish_decompress
JPP((j_decompress_ptr cinfo
));
1061 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
1062 EXTERN(JDIMENSION
) jpeg_read_raw_data
JPP((j_decompress_ptr cinfo
,
1064 JDIMENSION max_lines
));
1066 /* Additional entry points for buffered-image mode. */
1067 EXTERN(boolean
) jpeg_has_multiple_scans
JPP((j_decompress_ptr cinfo
));
1068 EXTERN(boolean
) jpeg_start_output
JPP((j_decompress_ptr cinfo
,
1070 EXTERN(boolean
) jpeg_finish_output
JPP((j_decompress_ptr cinfo
));
1071 EXTERN(boolean
) jpeg_input_complete
JPP((j_decompress_ptr cinfo
));
1072 EXTERN(void) jpeg_new_colormap
JPP((j_decompress_ptr cinfo
));
1073 EXTERN(int) jpeg_consume_input
JPP((j_decompress_ptr cinfo
));
1074 /* Return value is one of: */
1075 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
1076 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */
1077 #define JPEG_REACHED_EOI 2 /* Reached end of image */
1078 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
1079 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
1081 /* Precalculate output dimensions for current decompression parameters. */
1082 EXTERN(void) jpeg_core_output_dimensions
JPP((j_decompress_ptr cinfo
));
1083 EXTERN(void) jpeg_calc_output_dimensions
JPP((j_decompress_ptr cinfo
));
1085 /* Control saving of COM and APPn markers into marker_list. */
1086 EXTERN(void) jpeg_save_markers
1087 JPP((j_decompress_ptr cinfo
, int marker_code
,
1088 unsigned int length_limit
));
1090 /* Install a special processing method for COM or APPn markers. */
1091 EXTERN(void) jpeg_set_marker_processor
1092 JPP((j_decompress_ptr cinfo
, int marker_code
,
1093 jpeg_marker_parser_method routine
));
1095 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
1096 EXTERN(jvirt_barray_ptr
*) jpeg_read_coefficients
JPP((j_decompress_ptr cinfo
));
1097 EXTERN(void) jpeg_write_coefficients
JPP((j_compress_ptr cinfo
,
1098 jvirt_barray_ptr
* coef_arrays
));
1099 EXTERN(void) jpeg_copy_critical_parameters
JPP((j_decompress_ptr srcinfo
,
1100 j_compress_ptr dstinfo
));
1102 /* If you choose to abort compression or decompression before completing
1103 * jpeg_finish_(de)compress, then you need to clean up to release memory,
1104 * temporary files, etc. You can just call jpeg_destroy_(de)compress
1105 * if you're done with the JPEG object, but if you want to clean it up and
1106 * reuse it, call this:
1108 EXTERN(void) jpeg_abort_compress
JPP((j_compress_ptr cinfo
));
1109 EXTERN(void) jpeg_abort_decompress
JPP((j_decompress_ptr cinfo
));
1111 /* Generic versions of jpeg_abort and jpeg_destroy that work on either
1112 * flavor of JPEG object. These may be more convenient in some places.
1114 EXTERN(void) jpeg_abort
JPP((j_common_ptr cinfo
));
1115 EXTERN(void) jpeg_destroy
JPP((j_common_ptr cinfo
));
1117 /* Default restart-marker-resync procedure for use by data source modules */
1118 EXTERN(boolean
) jpeg_resync_to_restart
JPP((j_decompress_ptr cinfo
,
1122 /* These marker codes are exported since applications and data source modules
1123 * are likely to want to use them.
1126 #define JPEG_RST0 0xD0 /* RST0 marker code */
1127 #define JPEG_EOI 0xD9 /* EOI marker code */
1128 #define JPEG_APP0 0xE0 /* APP0 marker code */
1129 #define JPEG_COM 0xFE /* COM marker code */
1132 /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1133 * for structure definitions that are never filled in, keep it quiet by
1134 * supplying dummy definitions for the various substructures.
1137 #ifdef INCOMPLETE_TYPES_BROKEN
1138 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
1139 struct jvirt_sarray_control
{ long dummy
; };
1140 struct jvirt_barray_control
{ long dummy
; };
1141 struct jpeg_comp_master
{ long dummy
; };
1142 struct jpeg_c_main_controller
{ long dummy
; };
1143 struct jpeg_c_prep_controller
{ long dummy
; };
1144 struct jpeg_c_coef_controller
{ long dummy
; };
1145 struct jpeg_marker_writer
{ long dummy
; };
1146 struct jpeg_color_converter
{ long dummy
; };
1147 struct jpeg_downsampler
{ long dummy
; };
1148 struct jpeg_forward_dct
{ long dummy
; };
1149 struct jpeg_entropy_encoder
{ long dummy
; };
1150 struct jpeg_decomp_master
{ long dummy
; };
1151 struct jpeg_d_main_controller
{ long dummy
; };
1152 struct jpeg_d_coef_controller
{ long dummy
; };
1153 struct jpeg_d_post_controller
{ long dummy
; };
1154 struct jpeg_input_controller
{ long dummy
; };
1155 struct jpeg_marker_reader
{ long dummy
; };
1156 struct jpeg_entropy_decoder
{ long dummy
; };
1157 struct jpeg_inverse_dct
{ long dummy
; };
1158 struct jpeg_upsampler
{ long dummy
; };
1159 struct jpeg_color_deconverter
{ long dummy
; };
1160 struct jpeg_color_quantizer
{ long dummy
; };
1161 #endif /* JPEG_INTERNALS */
1162 #endif /* INCOMPLETE_TYPES_BROKEN */
1166 * The JPEG library modules define JPEG_INTERNALS before including this file.
1167 * The internal structure declarations are read only when that is true.
1168 * Applications using the library should not include jpegint.h, but may wish
1169 * to include jerror.h.
1172 #ifdef JPEG_INTERNALS
1173 #include "jpegint.h" /* fetch private declarations */
1174 #include "jerror.h" /* fetch error codes too */
1178 #ifndef DONT_USE_EXTERN_C
1183 #endif /* JPEGLIB_H */