source: trunk/libjpeg/jpeglib.h @ 283

Last change on this file since 283 was 283, checked in by rbri, 12 years ago

JPEG plugin: libjpeg updated to version 7

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1/*
2 * jpeglib.h
3 *
4 * Copyright (C) 1991-1998, Thomas G. Lane.
5 * Modified 2002-2009 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.
8 *
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.
12 */
13
14#ifndef JPEGLIB_H
15#define JPEGLIB_H
16
17/*
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.
22 */
23
24#ifndef JCONFIG_INCLUDED        /* in case jinclude.h already did */
25#include "jconfig.h"            /* widely used configuration options */
26#endif
27#include "jmorecfg.h"           /* seldom changed options */
28
29
30#ifdef __cplusplus
31#ifndef DONT_USE_EXTERN_C
32extern "C" {
33#endif
34#endif
35
36/* Version ID for the JPEG library.
37 * Might be useful for tests like "#if JPEG_LIB_VERSION >= 70".
38 */
39
40#define JPEG_LIB_VERSION  70    /* Version 7.0 */
41
42
43/* Various constants determining the sizes of things.
44 * All of these are specified by the JPEG standard, so don't change them
45 * if you want to be compatible.
46 */
47
48#define DCTSIZE             8   /* The basic DCT block is 8x8 samples */
49#define DCTSIZE2            64  /* DCTSIZE squared; # of elements in a block */
50#define NUM_QUANT_TBLS      4   /* Quantization tables are numbered 0..3 */
51#define NUM_HUFF_TBLS       4   /* Huffman tables are numbered 0..3 */
52#define NUM_ARITH_TBLS      16  /* Arith-coding tables are numbered 0..15 */
53#define MAX_COMPS_IN_SCAN   4   /* JPEG limit on # of components in one scan */
54#define MAX_SAMP_FACTOR     4   /* JPEG limit on sampling factors */
55/* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
56 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
57 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
58 * to handle it.  We even let you do this from the jconfig.h file.  However,
59 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
60 * sometimes emits noncompliant files doesn't mean you should too.
61 */
62#define C_MAX_BLOCKS_IN_MCU   10 /* compressor's limit on blocks per MCU */
63#ifndef D_MAX_BLOCKS_IN_MCU
64#define D_MAX_BLOCKS_IN_MCU   10 /* decompressor's limit on blocks per MCU */
65#endif
66
67
68/* Data structures for images (arrays of samples and of DCT coefficients).
69 * On 80x86 machines, the image arrays are too big for near pointers,
70 * but the pointer arrays can fit in near memory.
71 */
72
73typedef JSAMPLE FAR *JSAMPROW;  /* ptr to one image row of pixel samples. */
74typedef JSAMPROW *JSAMPARRAY;   /* ptr to some rows (a 2-D sample array) */
75typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
76
77typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
78typedef JBLOCK FAR *JBLOCKROW;  /* pointer to one row of coefficient blocks */
79typedef JBLOCKROW *JBLOCKARRAY;         /* a 2-D array of coefficient blocks */
80typedef JBLOCKARRAY *JBLOCKIMAGE;       /* a 3-D array of coefficient blocks */
81
82typedef JCOEF FAR *JCOEFPTR;    /* useful in a couple of places */
83
84
85/* Types for JPEG compression parameters and working tables. */
86
87
88/* DCT coefficient quantization tables. */
89
90typedef struct {
91  /* This array gives the coefficient quantizers in natural array order
92   * (not the zigzag order in which they are stored in a JPEG DQT marker).
93   * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
94   */
95  UINT16 quantval[DCTSIZE2];    /* quantization step for each coefficient */
96  /* This field is used only during compression.  It's initialized FALSE when
97   * the table is created, and set TRUE when it's been output to the file.
98   * You could suppress output of a table by setting this to TRUE.
99   * (See jpeg_suppress_tables for an example.)
100   */
101  boolean sent_table;           /* TRUE when table has been output */
102} JQUANT_TBL;
103
104
105/* Huffman coding tables. */
106
107typedef struct {
108  /* These two fields directly represent the contents of a JPEG DHT marker */
109  UINT8 bits[17];               /* bits[k] = # of symbols with codes of */
110                                /* length k bits; bits[0] is unused */
111  UINT8 huffval[256];           /* The symbols, in order of incr code length */
112  /* This field is used only during compression.  It's initialized FALSE when
113   * the table is created, and set TRUE when it's been output to the file.
114   * You could suppress output of a table by setting this to TRUE.
115   * (See jpeg_suppress_tables for an example.)
116   */
117  boolean sent_table;           /* TRUE when table has been output */
118} JHUFF_TBL;
119
120
121/* Basic info about one component (color channel). */
122
123typedef struct {
124  /* These values are fixed over the whole image. */
125  /* For compression, they must be supplied by parameter setup; */
126  /* for decompression, they are read from the SOF marker. */
127  int component_id;             /* identifier for this component (0..255) */
128  int component_index;          /* its index in SOF or cinfo->comp_info[] */
129  int h_samp_factor;            /* horizontal sampling factor (1..4) */
130  int v_samp_factor;            /* vertical sampling factor (1..4) */
131  int quant_tbl_no;             /* quantization table selector (0..3) */
132  /* These values may vary between scans. */
133  /* For compression, they must be supplied by parameter setup; */
134  /* for decompression, they are read from the SOS marker. */
135  /* The decompressor output side may not use these variables. */
136  int dc_tbl_no;                /* DC entropy table selector (0..3) */
137  int ac_tbl_no;                /* AC entropy table selector (0..3) */
138 
139  /* Remaining fields should be treated as private by applications. */
140 
141  /* These values are computed during compression or decompression startup: */
142  /* Component's size in DCT blocks.
143   * Any dummy blocks added to complete an MCU are not counted; therefore
144   * these values do not depend on whether a scan is interleaved or not.
145   */
146  JDIMENSION width_in_blocks;
147  JDIMENSION height_in_blocks;
148  /* Size of a DCT block in samples,
149   * reflecting any scaling we choose to apply during the DCT step.
150   * Values from 1 to 16 are supported.
151   * Note that different components may receive different DCT scalings.
152   */
153  int DCT_h_scaled_size;
154  int DCT_v_scaled_size;
155  /* The downsampled dimensions are the component's actual, unpadded number
156   * of samples at the main buffer (preprocessing/compression interface);
157   * DCT scaling is included, so
158   * downsampled_width = ceil(image_width * Hi/Hmax * DCT_h_scaled_size/DCTSIZE)
159   * and similarly for height.
160   */
161  JDIMENSION downsampled_width;  /* actual width in samples */
162  JDIMENSION downsampled_height; /* actual height in samples */
163  /* This flag is used only for decompression.  In cases where some of the
164   * components will be ignored (eg grayscale output from YCbCr image),
165   * we can skip most computations for the unused components.
166   */
167  boolean component_needed;     /* do we need the value of this component? */
168
169  /* These values are computed before starting a scan of the component. */
170  /* The decompressor output side may not use these variables. */
171  int MCU_width;                /* number of blocks per MCU, horizontally */
172  int MCU_height;               /* number of blocks per MCU, vertically */
173  int MCU_blocks;               /* MCU_width * MCU_height */
174  int MCU_sample_width;         /* MCU width in samples, MCU_width*DCT_scaled_size */
175  int last_col_width;           /* # of non-dummy blocks across in last MCU */
176  int last_row_height;          /* # of non-dummy blocks down in last MCU */
177
178  /* Saved quantization table for component; NULL if none yet saved.
179   * See jdinput.c comments about the need for this information.
180   * This field is currently used only for decompression.
181   */
182  JQUANT_TBL * quant_table;
183
184  /* Private per-component storage for DCT or IDCT subsystem. */
185  void * dct_table;
186} jpeg_component_info;
187
188
189/* The script for encoding a multiple-scan file is an array of these: */
190
191typedef struct {
192  int comps_in_scan;            /* number of components encoded in this scan */
193  int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
194  int Ss, Se;                   /* progressive JPEG spectral selection parms */
195  int Ah, Al;                   /* progressive JPEG successive approx. parms */
196} jpeg_scan_info;
197
198/* The decompressor can save APPn and COM markers in a list of these: */
199
200typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr;
201
202struct jpeg_marker_struct {
203  jpeg_saved_marker_ptr next;   /* next in list, or NULL */
204  UINT8 marker;                 /* marker code: JPEG_COM, or JPEG_APP0+n */
205  unsigned int original_length; /* # bytes of data in the file */
206  unsigned int data_length;     /* # bytes of data saved at data[] */
207  JOCTET FAR * data;            /* the data contained in the marker */
208  /* the marker length word is not counted in data_length or original_length */
209};
210
211/* Known color spaces. */
212
213typedef enum {
214        JCS_UNKNOWN,            /* error/unspecified */
215        JCS_GRAYSCALE,          /* monochrome */
216        JCS_RGB,                /* red/green/blue */
217        JCS_YCbCr,              /* Y/Cb/Cr (also known as YUV) */
218        JCS_CMYK,               /* C/M/Y/K */
219        JCS_YCCK                /* Y/Cb/Cr/K */
220} J_COLOR_SPACE;
221
222/* DCT/IDCT algorithm options. */
223
224typedef enum {
225        JDCT_ISLOW,             /* slow but accurate integer algorithm */
226        JDCT_IFAST,             /* faster, less accurate integer method */
227        JDCT_FLOAT              /* floating-point: accurate, fast on fast HW */
228} J_DCT_METHOD;
229
230#ifndef JDCT_DEFAULT            /* may be overridden in jconfig.h */
231#define JDCT_DEFAULT  JDCT_ISLOW
232#endif
233#ifndef JDCT_FASTEST            /* may be overridden in jconfig.h */
234#define JDCT_FASTEST  JDCT_IFAST
235#endif
236
237/* Dithering options for decompression. */
238
239typedef enum {
240        JDITHER_NONE,           /* no dithering */
241        JDITHER_ORDERED,        /* simple ordered dither */
242        JDITHER_FS              /* Floyd-Steinberg error diffusion dither */
243} J_DITHER_MODE;
244
245
246/* Common fields between JPEG compression and decompression master structs. */
247
248#define jpeg_common_fields \
249  struct jpeg_error_mgr * err;  /* Error handler module */\
250  struct jpeg_memory_mgr * mem; /* Memory manager module */\
251  struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
252  void * client_data;           /* Available for use by application */\
253  boolean is_decompressor;      /* So common code can tell which is which */\
254  int global_state              /* For checking call sequence validity */
255
256/* Routines that are to be used by both halves of the library are declared
257 * to receive a pointer to this structure.  There are no actual instances of
258 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
259 */
260struct jpeg_common_struct {
261  jpeg_common_fields;           /* Fields common to both master struct types */
262  /* Additional fields follow in an actual jpeg_compress_struct or
263   * jpeg_decompress_struct.  All three structs must agree on these
264   * initial fields!  (This would be a lot cleaner in C++.)
265   */
266};
267
268typedef struct jpeg_common_struct * j_common_ptr;
269typedef struct jpeg_compress_struct * j_compress_ptr;
270typedef struct jpeg_decompress_struct * j_decompress_ptr;
271
272
273/* Master record for a compression instance */
274
275struct jpeg_compress_struct {
276  jpeg_common_fields;           /* Fields shared with jpeg_decompress_struct */
277
278  /* Destination for compressed data */
279  struct jpeg_destination_mgr * dest;
280
281  /* Description of source image --- these fields must be filled in by
282   * outer application before starting compression.  in_color_space must
283   * be correct before you can even call jpeg_set_defaults().
284   */
285
286  JDIMENSION image_width;       /* input image width */
287  JDIMENSION image_height;      /* input image height */
288  int input_components;         /* # of color components in input image */
289  J_COLOR_SPACE in_color_space; /* colorspace of input image */
290
291  double input_gamma;           /* image gamma of input image */
292
293  /* Compression parameters --- these fields must be set before calling
294   * jpeg_start_compress().  We recommend calling jpeg_set_defaults() to
295   * initialize everything to reasonable defaults, then changing anything
296   * the application specifically wants to change.  That way you won't get
297   * burnt when new parameters are added.  Also note that there are several
298   * helper routines to simplify changing parameters.
299   */
300
301  unsigned int scale_num, scale_denom; /* fraction by which to scale image */
302
303  JDIMENSION jpeg_width;        /* scaled JPEG image width */
304  JDIMENSION jpeg_height;       /* scaled JPEG image height */
305  /* Dimensions of actual JPEG image that will be written to file,
306   * derived from input dimensions by scaling factors above.
307   * These fields are computed by jpeg_start_compress().
308   * You can also use jpeg_calc_jpeg_dimensions() to determine these values
309   * in advance of calling jpeg_start_compress().
310   */
311
312  int data_precision;           /* bits of precision in image data */
313
314  int num_components;           /* # of color components in JPEG image */
315  J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
316
317  jpeg_component_info * comp_info;
318  /* comp_info[i] describes component that appears i'th in SOF */
319
320  JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
321  int q_scale_factor[NUM_QUANT_TBLS];
322  /* ptrs to coefficient quantization tables, or NULL if not defined,
323   * and corresponding scale factors (percentage, initialized 100).
324   */
325
326  JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
327  JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
328  /* ptrs to Huffman coding tables, or NULL if not defined */
329
330  UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
331  UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
332  UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
333
334  int num_scans;                /* # of entries in scan_info array */
335  const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */
336  /* The default value of scan_info is NULL, which causes a single-scan
337   * sequential JPEG file to be emitted.  To create a multi-scan file,
338   * set num_scans and scan_info to point to an array of scan definitions.
339   */
340
341  boolean raw_data_in;          /* TRUE=caller supplies downsampled data */
342  boolean arith_code;           /* TRUE=arithmetic coding, FALSE=Huffman */
343  boolean optimize_coding;      /* TRUE=optimize entropy encoding parms */
344  boolean CCIR601_sampling;     /* TRUE=first samples are cosited */
345  boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
346  int smoothing_factor;         /* 1..100, or 0 for no input smoothing */
347  J_DCT_METHOD dct_method;      /* DCT algorithm selector */
348
349  /* The restart interval can be specified in absolute MCUs by setting
350   * restart_interval, or in MCU rows by setting restart_in_rows
351   * (in which case the correct restart_interval will be figured
352   * for each scan).
353   */
354  unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
355  int restart_in_rows;          /* if > 0, MCU rows per restart interval */
356
357  /* Parameters controlling emission of special markers. */
358
359  boolean write_JFIF_header;    /* should a JFIF marker be written? */
360  UINT8 JFIF_major_version;     /* What to write for the JFIF version number */
361  UINT8 JFIF_minor_version;
362  /* These three values are not used by the JPEG code, merely copied */
363  /* into the JFIF APP0 marker.  density_unit can be 0 for unknown, */
364  /* 1 for dots/inch, or 2 for dots/cm.  Note that the pixel aspect */
365  /* ratio is defined by X_density/Y_density even when density_unit=0. */
366  UINT8 density_unit;           /* JFIF code for pixel size units */
367  UINT16 X_density;             /* Horizontal pixel density */
368  UINT16 Y_density;             /* Vertical pixel density */
369  boolean write_Adobe_marker;   /* should an Adobe marker be written? */
370 
371  /* State variable: index of next scanline to be written to
372   * jpeg_write_scanlines().  Application may use this to control its
373   * processing loop, e.g., "while (next_scanline < image_height)".
374   */
375
376  JDIMENSION next_scanline;     /* 0 .. image_height-1  */
377
378  /* Remaining fields are known throughout compressor, but generally
379   * should not be touched by a surrounding application.
380   */
381
382  /*
383   * These fields are computed during compression startup
384   */
385  boolean progressive_mode;     /* TRUE if scan script uses progressive mode */
386  int max_h_samp_factor;        /* largest h_samp_factor */
387  int max_v_samp_factor;        /* largest v_samp_factor */
388
389  int min_DCT_h_scaled_size;    /* smallest DCT_h_scaled_size of any component */
390  int min_DCT_v_scaled_size;    /* smallest DCT_v_scaled_size of any component */
391
392  JDIMENSION total_iMCU_rows;   /* # of iMCU rows to be input to coef ctlr */
393  /* The coefficient controller receives data in units of MCU rows as defined
394   * for fully interleaved scans (whether the JPEG file is interleaved or not).
395   * There are v_samp_factor * DCTSIZE sample rows of each component in an
396   * "iMCU" (interleaved MCU) row.
397   */
398 
399  /*
400   * These fields are valid during any one scan.
401   * They describe the components and MCUs actually appearing in the scan.
402   */
403  int comps_in_scan;            /* # of JPEG components in this scan */
404  jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
405  /* *cur_comp_info[i] describes component that appears i'th in SOS */
406 
407  JDIMENSION MCUs_per_row;      /* # of MCUs across the image */
408  JDIMENSION MCU_rows_in_scan;  /* # of MCU rows in the image */
409 
410  int blocks_in_MCU;            /* # of DCT blocks per MCU */
411  int MCU_membership[C_MAX_BLOCKS_IN_MCU];
412  /* MCU_membership[i] is index in cur_comp_info of component owning */
413  /* i'th block in an MCU */
414
415  int Ss, Se, Ah, Al;           /* progressive JPEG parameters for scan */
416
417  /*
418   * Links to compression subobjects (methods and private variables of modules)
419   */
420  struct jpeg_comp_master * master;
421  struct jpeg_c_main_controller * main;
422  struct jpeg_c_prep_controller * prep;
423  struct jpeg_c_coef_controller * coef;
424  struct jpeg_marker_writer * marker;
425  struct jpeg_color_converter * cconvert;
426  struct jpeg_downsampler * downsample;
427  struct jpeg_forward_dct * fdct;
428  struct jpeg_entropy_encoder * entropy;
429  jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */
430  int script_space_size;
431};
432
433
434/* Master record for a decompression instance */
435
436struct jpeg_decompress_struct {
437  jpeg_common_fields;           /* Fields shared with jpeg_compress_struct */
438
439  /* Source of compressed data */
440  struct jpeg_source_mgr * src;
441
442  /* Basic description of image --- filled in by jpeg_read_header(). */
443  /* Application may inspect these values to decide how to process image. */
444
445  JDIMENSION image_width;       /* nominal image width (from SOF marker) */
446  JDIMENSION image_height;      /* nominal image height */
447  int num_components;           /* # of color components in JPEG image */
448  J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
449
450  /* Decompression processing parameters --- these fields must be set before
451   * calling jpeg_start_decompress().  Note that jpeg_read_header() initializes
452   * them to default values.
453   */
454
455  J_COLOR_SPACE out_color_space; /* colorspace for output */
456
457  unsigned int scale_num, scale_denom; /* fraction by which to scale image */
458
459  double output_gamma;          /* image gamma wanted in output */
460
461  boolean buffered_image;       /* TRUE=multiple output passes */
462  boolean raw_data_out;         /* TRUE=downsampled data wanted */
463
464  J_DCT_METHOD dct_method;      /* IDCT algorithm selector */
465  boolean do_fancy_upsampling;  /* TRUE=apply fancy upsampling */
466  boolean do_block_smoothing;   /* TRUE=apply interblock smoothing */
467
468  boolean quantize_colors;      /* TRUE=colormapped output wanted */
469  /* the following are ignored if not quantize_colors: */
470  J_DITHER_MODE dither_mode;    /* type of color dithering to use */
471  boolean two_pass_quantize;    /* TRUE=use two-pass color quantization */
472  int desired_number_of_colors; /* max # colors to use in created colormap */
473  /* these are significant only in buffered-image mode: */
474  boolean enable_1pass_quant;   /* enable future use of 1-pass quantizer */
475  boolean enable_external_quant;/* enable future use of external colormap */
476  boolean enable_2pass_quant;   /* enable future use of 2-pass quantizer */
477
478  /* Description of actual output image that will be returned to application.
479   * These fields are computed by jpeg_start_decompress().
480   * You can also use jpeg_calc_output_dimensions() to determine these values
481   * in advance of calling jpeg_start_decompress().
482   */
483
484  JDIMENSION output_width;      /* scaled image width */
485  JDIMENSION output_height;     /* scaled image height */
486  int out_color_components;     /* # of color components in out_color_space */
487  int output_components;        /* # of color components returned */
488  /* output_components is 1 (a colormap index) when quantizing colors;
489   * otherwise it equals out_color_components.
490   */
491  int rec_outbuf_height;        /* min recommended height of scanline buffer */
492  /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
493   * high, space and time will be wasted due to unnecessary data copying.
494   * Usually rec_outbuf_height will be 1 or 2, at most 4.
495   */
496
497  /* When quantizing colors, the output colormap is described by these fields.
498   * The application can supply a colormap by setting colormap non-NULL before
499   * calling jpeg_start_decompress; otherwise a colormap is created during
500   * jpeg_start_decompress or jpeg_start_output.
501   * The map has out_color_components rows and actual_number_of_colors columns.
502   */
503  int actual_number_of_colors;  /* number of entries in use */
504  JSAMPARRAY colormap;          /* The color map as a 2-D pixel array */
505
506  /* State variables: these variables indicate the progress of decompression.
507   * The application may examine these but must not modify them.
508   */
509
510  /* Row index of next scanline to be read from jpeg_read_scanlines().
511   * Application may use this to control its processing loop, e.g.,
512   * "while (output_scanline < output_height)".
513   */
514  JDIMENSION output_scanline;   /* 0 .. output_height-1  */
515
516  /* Current input scan number and number of iMCU rows completed in scan.
517   * These indicate the progress of the decompressor input side.
518   */
519  int input_scan_number;        /* Number of SOS markers seen so far */
520  JDIMENSION input_iMCU_row;    /* Number of iMCU rows completed */
521
522  /* The "output scan number" is the notional scan being displayed by the
523   * output side.  The decompressor will not allow output scan/row number
524   * to get ahead of input scan/row, but it can fall arbitrarily far behind.
525   */
526  int output_scan_number;       /* Nominal scan number being displayed */
527  JDIMENSION output_iMCU_row;   /* Number of iMCU rows read */
528
529  /* Current progression status.  coef_bits[c][i] indicates the precision
530   * with which component c's DCT coefficient i (in zigzag order) is known.
531   * It is -1 when no data has yet been received, otherwise it is the point
532   * transform (shift) value for the most recent scan of the coefficient
533   * (thus, 0 at completion of the progression).
534   * This pointer is NULL when reading a non-progressive file.
535   */
536  int (*coef_bits)[DCTSIZE2];   /* -1 or current Al value for each coef */
537
538  /* Internal JPEG parameters --- the application usually need not look at
539   * these fields.  Note that the decompressor output side may not use
540   * any parameters that can change between scans.
541   */
542
543  /* Quantization and Huffman tables are carried forward across input
544   * datastreams when processing abbreviated JPEG datastreams.
545   */
546
547  JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
548  /* ptrs to coefficient quantization tables, or NULL if not defined */
549
550  JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
551  JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
552  /* ptrs to Huffman coding tables, or NULL if not defined */
553
554  /* These parameters are never carried across datastreams, since they
555   * are given in SOF/SOS markers or defined to be reset by SOI.
556   */
557
558  int data_precision;           /* bits of precision in image data */
559
560  jpeg_component_info * comp_info;
561  /* comp_info[i] describes component that appears i'th in SOF */
562
563  boolean progressive_mode;     /* TRUE if SOFn specifies progressive mode */
564  boolean arith_code;           /* TRUE=arithmetic coding, FALSE=Huffman */
565
566  UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
567  UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
568  UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
569
570  unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
571
572  /* These fields record data obtained from optional markers recognized by
573   * the JPEG library.
574   */
575  boolean saw_JFIF_marker;      /* TRUE iff a JFIF APP0 marker was found */
576  /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
577  UINT8 JFIF_major_version;     /* JFIF version number */
578  UINT8 JFIF_minor_version;
579  UINT8 density_unit;           /* JFIF code for pixel size units */
580  UINT16 X_density;             /* Horizontal pixel density */
581  UINT16 Y_density;             /* Vertical pixel density */
582  boolean saw_Adobe_marker;     /* TRUE iff an Adobe APP14 marker was found */
583  UINT8 Adobe_transform;        /* Color transform code from Adobe marker */
584
585  boolean CCIR601_sampling;     /* TRUE=first samples are cosited */
586
587  /* Aside from the specific data retained from APPn markers known to the
588   * library, the uninterpreted contents of any or all APPn and COM markers
589   * can be saved in a list for examination by the application.
590   */
591  jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
592
593  /* Remaining fields are known throughout decompressor, but generally
594   * should not be touched by a surrounding application.
595   */
596
597  /*
598   * These fields are computed during decompression startup
599   */
600  int max_h_samp_factor;        /* largest h_samp_factor */
601  int max_v_samp_factor;        /* largest v_samp_factor */
602
603  int min_DCT_h_scaled_size;    /* smallest DCT_h_scaled_size of any component */
604  int min_DCT_v_scaled_size;    /* smallest DCT_v_scaled_size of any component */
605
606  JDIMENSION total_iMCU_rows;   /* # of iMCU rows in image */
607  /* The coefficient controller's input and output progress is measured in
608   * units of "iMCU" (interleaved MCU) rows.  These are the same as MCU rows
609   * in fully interleaved JPEG scans, but are used whether the scan is
610   * interleaved or not.  We define an iMCU row as v_samp_factor DCT block
611   * rows of each component.  Therefore, the IDCT output contains
612   * v_samp_factor*DCT_v_scaled_size sample rows of a component per iMCU row.
613   */
614
615  JSAMPLE * sample_range_limit; /* table for fast range-limiting */
616
617  /*
618   * These fields are valid during any one scan.
619   * They describe the components and MCUs actually appearing in the scan.
620   * Note that the decompressor output side must not use these fields.
621   */
622  int comps_in_scan;            /* # of JPEG components in this scan */
623  jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
624  /* *cur_comp_info[i] describes component that appears i'th in SOS */
625
626  JDIMENSION MCUs_per_row;      /* # of MCUs across the image */
627  JDIMENSION MCU_rows_in_scan;  /* # of MCU rows in the image */
628
629  int blocks_in_MCU;            /* # of DCT blocks per MCU */
630  int MCU_membership[D_MAX_BLOCKS_IN_MCU];
631  /* MCU_membership[i] is index in cur_comp_info of component owning */
632  /* i'th block in an MCU */
633
634  int Ss, Se, Ah, Al;           /* progressive JPEG parameters for scan */
635
636  /* This field is shared between entropy decoder and marker parser.
637   * It is either zero or the code of a JPEG marker that has been
638   * read from the data source, but has not yet been processed.
639   */
640  int unread_marker;
641
642  /*
643   * Links to decompression subobjects (methods, private variables of modules)
644   */
645  struct jpeg_decomp_master * master;
646  struct jpeg_d_main_controller * main;
647  struct jpeg_d_coef_controller * coef;
648  struct jpeg_d_post_controller * post;
649  struct jpeg_input_controller * inputctl;
650  struct jpeg_marker_reader * marker;
651  struct jpeg_entropy_decoder * entropy;
652  struct jpeg_inverse_dct * idct;
653  struct jpeg_upsampler * upsample;
654  struct jpeg_color_deconverter * cconvert;
655  struct jpeg_color_quantizer * cquantize;
656};
657
658
659/* "Object" declarations for JPEG modules that may be supplied or called
660 * directly by the surrounding application.
661 * As with all objects in the JPEG library, these structs only define the
662 * publicly visible methods and state variables of a module.  Additional
663 * private fields may exist after the public ones.
664 */
665
666
667/* Error handler object */
668
669struct jpeg_error_mgr {
670  /* Error exit handler: does not return to caller */
671  JMETHOD(void, error_exit, (j_common_ptr cinfo));
672  /* Conditionally emit a trace or warning message */
673  JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
674  /* Routine that actually outputs a trace or error message */
675  JMETHOD(void, output_message, (j_common_ptr cinfo));
676  /* Format a message string for the most recent JPEG error or message */
677  JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
678#define JMSG_LENGTH_MAX  200    /* recommended size of format_message buffer */
679  /* Reset error state variables at start of a new image */
680  JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
681 
682  /* The message ID code and any parameters are saved here.
683   * A message can have one string parameter or up to 8 int parameters.
684   */
685  int msg_code;
686#define JMSG_STR_PARM_MAX  80
687  union {
688    int i[8];
689    char s[JMSG_STR_PARM_MAX];
690  } msg_parm;
691 
692  /* Standard state variables for error facility */
693 
694  int trace_level;              /* max msg_level that will be displayed */
695 
696  /* For recoverable corrupt-data errors, we emit a warning message,
697   * but keep going unless emit_message chooses to abort.  emit_message
698   * should count warnings in num_warnings.  The surrounding application
699   * can check for bad data by seeing if num_warnings is nonzero at the
700   * end of processing.
701   */
702  long num_warnings;            /* number of corrupt-data warnings */
703
704  /* These fields point to the table(s) of error message strings.
705   * An application can change the table pointer to switch to a different
706   * message list (typically, to change the language in which errors are
707   * reported).  Some applications may wish to add additional error codes
708   * that will be handled by the JPEG library error mechanism; the second
709   * table pointer is used for this purpose.
710   *
711   * First table includes all errors generated by JPEG library itself.
712   * Error code 0 is reserved for a "no such error string" message.
713   */
714  const char * const * jpeg_message_table; /* Library errors */
715  int last_jpeg_message;    /* Table contains strings 0..last_jpeg_message */
716  /* Second table can be added by application (see cjpeg/djpeg for example).
717   * It contains strings numbered first_addon_message..last_addon_message.
718   */
719  const char * const * addon_message_table; /* Non-library errors */
720  int first_addon_message;      /* code for first string in addon table */
721  int last_addon_message;       /* code for last string in addon table */
722};
723
724
725/* Progress monitor object */
726
727struct jpeg_progress_mgr {
728  JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
729
730  long pass_counter;            /* work units completed in this pass */
731  long pass_limit;              /* total number of work units in this pass */
732  int completed_passes;         /* passes completed so far */
733  int total_passes;             /* total number of passes expected */
734};
735
736
737/* Data destination object for compression */
738
739struct jpeg_destination_mgr {
740  JOCTET * next_output_byte;    /* => next byte to write in buffer */
741  size_t free_in_buffer;        /* # of byte spaces remaining in buffer */
742
743  JMETHOD(void, init_destination, (j_compress_ptr cinfo));
744  JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
745  JMETHOD(void, term_destination, (j_compress_ptr cinfo));
746};
747
748
749/* Data source object for decompression */
750
751struct jpeg_source_mgr {
752  const JOCTET * next_input_byte; /* => next byte to read from buffer */
753  size_t bytes_in_buffer;       /* # of bytes remaining in buffer */
754
755  JMETHOD(void, init_source, (j_decompress_ptr cinfo));
756  JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
757  JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
758  JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
759  JMETHOD(void, term_source, (j_decompress_ptr cinfo));
760};
761
762
763/* Memory manager object.
764 * Allocates "small" objects (a few K total), "large" objects (tens of K),
765 * and "really big" objects (virtual arrays with backing store if needed).
766 * The memory manager does not allow individual objects to be freed; rather,
767 * each created object is assigned to a pool, and whole pools can be freed
768 * at once.  This is faster and more convenient than remembering exactly what
769 * to free, especially where malloc()/free() are not too speedy.
770 * NB: alloc routines never return NULL.  They exit to error_exit if not
771 * successful.
772 */
773
774#define JPOOL_PERMANENT 0       /* lasts until master record is destroyed */
775#define JPOOL_IMAGE     1       /* lasts until done with image/datastream */
776#define JPOOL_NUMPOOLS  2
777
778typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
779typedef struct jvirt_barray_control * jvirt_barray_ptr;
780
781
782struct jpeg_memory_mgr {
783  /* Method pointers */
784  JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
785                                size_t sizeofobject));
786  JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
787                                     size_t sizeofobject));
788  JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
789                                     JDIMENSION samplesperrow,
790                                     JDIMENSION numrows));
791  JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
792                                      JDIMENSION blocksperrow,
793                                      JDIMENSION numrows));
794  JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
795                                                  int pool_id,
796                                                  boolean pre_zero,
797                                                  JDIMENSION samplesperrow,
798                                                  JDIMENSION numrows,
799                                                  JDIMENSION maxaccess));
800  JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
801                                                  int pool_id,
802                                                  boolean pre_zero,
803                                                  JDIMENSION blocksperrow,
804                                                  JDIMENSION numrows,
805                                                  JDIMENSION maxaccess));
806  JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
807  JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
808                                           jvirt_sarray_ptr ptr,
809                                           JDIMENSION start_row,
810                                           JDIMENSION num_rows,
811                                           boolean writable));
812  JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
813                                            jvirt_barray_ptr ptr,
814                                            JDIMENSION start_row,
815                                            JDIMENSION num_rows,
816                                            boolean writable));
817  JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
818  JMETHOD(void, self_destruct, (j_common_ptr cinfo));
819
820  /* Limit on memory allocation for this JPEG object.  (Note that this is
821   * merely advisory, not a guaranteed maximum; it only affects the space
822   * used for virtual-array buffers.)  May be changed by outer application
823   * after creating the JPEG object.
824   */
825  long max_memory_to_use;
826
827  /* Maximum allocation request accepted by alloc_large. */
828  long max_alloc_chunk;
829};
830
831
832/* Routine signature for application-supplied marker processing methods.
833 * Need not pass marker code since it is stored in cinfo->unread_marker.
834 */
835typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
836
837
838/* Declarations for routines called by application.
839 * The JPP macro hides prototype parameters from compilers that can't cope.
840 * Note JPP requires double parentheses.
841 */
842
843#ifdef HAVE_PROTOTYPES
844#define JPP(arglist)    arglist
845#else
846#define JPP(arglist)    ()
847#endif
848
849
850/* Short forms of external names for systems with brain-damaged linkers.
851 * We shorten external names to be unique in the first six letters, which
852 * is good enough for all known systems.
853 * (If your compiler itself needs names to be unique in less than 15
854 * characters, you are out of luck.  Get a better compiler.)
855 */
856
857#ifdef NEED_SHORT_EXTERNAL_NAMES
858#define jpeg_std_error          jStdError
859#define jpeg_CreateCompress     jCreaCompress
860#define jpeg_CreateDecompress   jCreaDecompress
861#define jpeg_destroy_compress   jDestCompress
862#define jpeg_destroy_decompress jDestDecompress
863#define jpeg_stdio_dest         jStdDest
864#define jpeg_stdio_src          jStdSrc
865#define jpeg_set_defaults       jSetDefaults
866#define jpeg_set_colorspace     jSetColorspace
867#define jpeg_default_colorspace jDefColorspace
868#define jpeg_set_quality        jSetQuality
869#define jpeg_set_linear_quality jSetLQuality
870#define jpeg_default_qtables    jDefQTables
871#define jpeg_add_quant_table    jAddQuantTable
872#define jpeg_quality_scaling    jQualityScaling
873#define jpeg_simple_progression jSimProgress
874#define jpeg_suppress_tables    jSuppressTables
875#define jpeg_alloc_quant_table  jAlcQTable
876#define jpeg_alloc_huff_table   jAlcHTable
877#define jpeg_start_compress     jStrtCompress
878#define jpeg_write_scanlines    jWrtScanlines
879#define jpeg_finish_compress    jFinCompress
880#define jpeg_calc_jpeg_dimensions       jCjpegDimensions
881#define jpeg_write_raw_data     jWrtRawData
882#define jpeg_write_marker       jWrtMarker
883#define jpeg_write_m_header     jWrtMHeader
884#define jpeg_write_m_byte       jWrtMByte
885#define jpeg_write_tables       jWrtTables
886#define jpeg_read_header        jReadHeader
887#define jpeg_start_decompress   jStrtDecompress
888#define jpeg_read_scanlines     jReadScanlines
889#define jpeg_finish_decompress  jFinDecompress
890#define jpeg_read_raw_data      jReadRawData
891#define jpeg_has_multiple_scans jHasMultScn
892#define jpeg_start_output       jStrtOutput
893#define jpeg_finish_output      jFinOutput
894#define jpeg_input_complete     jInComplete
895#define jpeg_new_colormap       jNewCMap
896#define jpeg_consume_input      jConsumeInput
897#define jpeg_calc_output_dimensions     jCalcDimensions
898#define jpeg_save_markers       jSaveMarkers
899#define jpeg_set_marker_processor       jSetMarker
900#define jpeg_read_coefficients  jReadCoefs
901#define jpeg_write_coefficients jWrtCoefs
902#define jpeg_copy_critical_parameters   jCopyCrit
903#define jpeg_abort_compress     jAbrtCompress
904#define jpeg_abort_decompress   jAbrtDecompress
905#define jpeg_abort              jAbort
906#define jpeg_destroy            jDestroy
907#define jpeg_resync_to_restart  jResyncRestart
908#endif /* NEED_SHORT_EXTERNAL_NAMES */
909
910
911/* Default error-management setup */
912EXTERN(struct jpeg_error_mgr *) jpeg_std_error
913        JPP((struct jpeg_error_mgr * err));
914
915/* Initialization of JPEG compression objects.
916 * jpeg_create_compress() and jpeg_create_decompress() are the exported
917 * names that applications should call.  These expand to calls on
918 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
919 * passed for version mismatch checking.
920 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
921 */
922#define jpeg_create_compress(cinfo) \
923    jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
924                        (size_t) sizeof(struct jpeg_compress_struct))
925#define jpeg_create_decompress(cinfo) \
926    jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
927                          (size_t) sizeof(struct jpeg_decompress_struct))
928EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo,
929                                      int version, size_t structsize));
930EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo,
931                                        int version, size_t structsize));
932/* Destruction of JPEG compression objects */
933EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo));
934EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
935
936/* Standard data source and destination managers: stdio streams. */
937/* Caller is responsible for opening the file before and closing after. */
938EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
939EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile));
940
941/* Default parameter setup for compression */
942EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo));
943/* Compression parameter setup aids */
944EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo,
945                                      J_COLOR_SPACE colorspace));
946EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo));
947EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
948                                   boolean force_baseline));
949EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
950                                          int scale_factor,
951                                          boolean force_baseline));
952EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo,
953                                       boolean force_baseline));
954EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
955                                       const unsigned int *basic_table,
956                                       int scale_factor,
957                                       boolean force_baseline));
958EXTERN(int) jpeg_quality_scaling JPP((int quality));
959EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo));
960EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo,
961                                       boolean suppress));
962EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo));
963EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo));
964
965/* Main entry points for compression */
966EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo,
967                                      boolean write_all_tables));
968EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo,
969                                             JSAMPARRAY scanlines,
970                                             JDIMENSION num_lines));
971EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo));
972
973/* Precalculate JPEG dimensions for current compression parameters. */
974EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo));
975
976/* Replaces jpeg_write_scanlines when writing raw downsampled data. */
977EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo,
978                                            JSAMPIMAGE data,
979                                            JDIMENSION num_lines));
980
981/* Write a special marker.  See libjpeg.txt concerning safe usage. */
982EXTERN(void) jpeg_write_marker
983        JPP((j_compress_ptr cinfo, int marker,
984             const JOCTET * dataptr, unsigned int datalen));
985/* Same, but piecemeal. */
986EXTERN(void) jpeg_write_m_header
987        JPP((j_compress_ptr cinfo, int marker, unsigned int datalen));
988EXTERN(void) jpeg_write_m_byte
989        JPP((j_compress_ptr cinfo, int val));
990
991/* Alternate compression function: just write an abbreviated table file */
992EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo));
993
994/* Decompression startup: read start of JPEG datastream to see what's there */
995EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo,
996                                  boolean require_image));
997/* Return value is one of: */
998#define JPEG_SUSPENDED          0 /* Suspended due to lack of input data */
999#define JPEG_HEADER_OK          1 /* Found valid image datastream */
1000#define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
1001/* If you pass require_image = TRUE (normal case), you need not check for
1002 * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
1003 * JPEG_SUSPENDED is only possible if you use a data source module that can
1004 * give a suspension return (the stdio source module doesn't).
1005 */
1006
1007/* Main entry points for decompression */
1008EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo));
1009EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
1010                                            JSAMPARRAY scanlines,
1011                                            JDIMENSION max_lines));
1012EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
1013
1014/* Replaces jpeg_read_scanlines when reading raw downsampled data. */
1015EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
1016                                           JSAMPIMAGE data,
1017                                           JDIMENSION max_lines));
1018
1019/* Additional entry points for buffered-image mode. */
1020EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
1021EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo,
1022                                       int scan_number));
1023EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo));
1024EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo));
1025EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo));
1026EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo));
1027/* Return value is one of: */
1028/* #define JPEG_SUSPENDED       0    Suspended due to lack of input data */
1029#define JPEG_REACHED_SOS        1 /* Reached start of new scan */
1030#define JPEG_REACHED_EOI        2 /* Reached end of image */
1031#define JPEG_ROW_COMPLETED      3 /* Completed one iMCU row */
1032#define JPEG_SCAN_COMPLETED     4 /* Completed last iMCU row of a scan */
1033
1034/* Precalculate output dimensions for current decompression parameters. */
1035EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo));
1036
1037/* Control saving of COM and APPn markers into marker_list. */
1038EXTERN(void) jpeg_save_markers
1039        JPP((j_decompress_ptr cinfo, int marker_code,
1040             unsigned int length_limit));
1041
1042/* Install a special processing method for COM or APPn markers. */
1043EXTERN(void) jpeg_set_marker_processor
1044        JPP((j_decompress_ptr cinfo, int marker_code,
1045             jpeg_marker_parser_method routine));
1046
1047/* Read or write raw DCT coefficients --- useful for lossless transcoding. */
1048EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo));
1049EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo,
1050                                          jvirt_barray_ptr * coef_arrays));
1051EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo,
1052                                                j_compress_ptr dstinfo));
1053
1054/* If you choose to abort compression or decompression before completing
1055 * jpeg_finish_(de)compress, then you need to clean up to release memory,
1056 * temporary files, etc.  You can just call jpeg_destroy_(de)compress
1057 * if you're done with the JPEG object, but if you want to clean it up and
1058 * reuse it, call this:
1059 */
1060EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo));
1061EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo));
1062
1063/* Generic versions of jpeg_abort and jpeg_destroy that work on either
1064 * flavor of JPEG object.  These may be more convenient in some places.
1065 */
1066EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo));
1067EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo));
1068
1069/* Default restart-marker-resync procedure for use by data source modules */
1070EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo,
1071                                            int desired));
1072
1073
1074/* These marker codes are exported since applications and data source modules
1075 * are likely to want to use them.
1076 */
1077
1078#define JPEG_RST0       0xD0    /* RST0 marker code */
1079#define JPEG_EOI        0xD9    /* EOI marker code */
1080#define JPEG_APP0       0xE0    /* APP0 marker code */
1081#define JPEG_COM        0xFE    /* COM marker code */
1082
1083
1084/* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1085 * for structure definitions that are never filled in, keep it quiet by
1086 * supplying dummy definitions for the various substructures.
1087 */
1088
1089#ifdef INCOMPLETE_TYPES_BROKEN
1090#ifndef JPEG_INTERNALS          /* will be defined in jpegint.h */
1091struct jvirt_sarray_control { long dummy; };
1092struct jvirt_barray_control { long dummy; };
1093struct jpeg_comp_master { long dummy; };
1094struct jpeg_c_main_controller { long dummy; };
1095struct jpeg_c_prep_controller { long dummy; };
1096struct jpeg_c_coef_controller { long dummy; };
1097struct jpeg_marker_writer { long dummy; };
1098struct jpeg_color_converter { long dummy; };
1099struct jpeg_downsampler { long dummy; };
1100struct jpeg_forward_dct { long dummy; };
1101struct jpeg_entropy_encoder { long dummy; };
1102struct jpeg_decomp_master { long dummy; };
1103struct jpeg_d_main_controller { long dummy; };
1104struct jpeg_d_coef_controller { long dummy; };
1105struct jpeg_d_post_controller { long dummy; };
1106struct jpeg_input_controller { long dummy; };
1107struct jpeg_marker_reader { long dummy; };
1108struct jpeg_entropy_decoder { long dummy; };
1109struct jpeg_inverse_dct { long dummy; };
1110struct jpeg_upsampler { long dummy; };
1111struct jpeg_color_deconverter { long dummy; };
1112struct jpeg_color_quantizer { long dummy; };
1113#endif /* JPEG_INTERNALS */
1114#endif /* INCOMPLETE_TYPES_BROKEN */
1115
1116
1117/*
1118 * The JPEG library modules define JPEG_INTERNALS before including this file.
1119 * The internal structure declarations are read only when that is true.
1120 * Applications using the library should not include jpegint.h, but may wish
1121 * to include jerror.h.
1122 */
1123
1124#ifdef JPEG_INTERNALS
1125#include "jpegint.h"            /* fetch private declarations */
1126#include "jerror.h"             /* fetch error codes too */
1127#endif
1128
1129#ifdef __cplusplus
1130#ifndef DONT_USE_EXTERN_C
1131}
1132#endif
1133#endif
1134
1135#endif /* JPEGLIB_H */
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