1 /*
2  * jpeglib.h
3  *
4  * Copyright (C) 1991-1998, Thomas G. Lane.
5  * This file is part of the Independent JPEG Group's software.
6  * For conditions of distribution and use, see the accompanying README file.
7  *
8  * This file defines the application interface for the JPEG library.
9  * Most applications using the library need only include this file,
10  * and perhaps jerror.h if they want to know the exact error codes.
11  */
12 
13 #ifndef JPEGLIB_H
14 #define JPEGLIB_H
15 
16 /*
17  * First we include the configuration files that record how this
18  * installation of the JPEG library is set up.  jconfig.h can be
19  * generated automatically for many systems.  jmorecfg.h contains
20  * manual configuration options that most people need not worry about.
21  */
22 
23 #ifndef JCONFIG_INCLUDED	/* in case jinclude.h already did */
24 #include "jconfig16.h"		/* widely used configuration options */
25 #endif
26 #include "jmorecfg16.h"		/* seldom changed options */
27 
28 
29 /* Version ID for the JPEG library.
30  * Might be useful for tests like "#if JPEG_LIB_VERSION >= 60".
31  */
32 
33 #define JPEG_LIB_VERSION  62	/* Version 6b */
34 
35 
36 /* Various constants determining the sizes of things.
37  * All of these are specified by the JPEG standard, so don't change them
38  * if you want to be compatible.
39  */
40 
41 #define DCTSIZE		    8	/* The basic DCT block is 8x8 samples */
42 #define DCTSIZE2	    64	/* DCTSIZE squared; # of elements in a block */
43 #define NUM_QUANT_TBLS      4	/* Quantization tables are numbered 0..3 */
44 #define NUM_HUFF_TBLS       4	/* Huffman tables are numbered 0..3 */
45 #define NUM_ARITH_TBLS      16	/* Arith-coding tables are numbered 0..15 */
46 #define MAX_COMPS_IN_SCAN   4	/* JPEG limit on # of components in one scan */
47 #define MAX_SAMP_FACTOR     4	/* JPEG limit on sampling factors */
48 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
49  * the PostScript DCT filter can emit files with many more than 10 data units
50  * per MCU.
51  * If you happen to run across such a file, you can up D_MAX_DATA_UNITS_IN_MCU
52  * to handle it.  We even let you do this from the jconfig.h file.  However,
53  * we strongly discourage changing C_MAX_DATA_UNITS_IN_MCU; just because Adobe
54  * sometimes emits noncompliant files doesn't mean you should too.
55  */
56 #define C_MAX_DATA_UNITS_IN_MCU   10 /* compressor's limit on data units/MCU */
57 #ifndef D_MAX_DATA_UNITS_IN_MCU
58 #define D_MAX_DATA_UNITS_IN_MCU   10 /* decompressor's limit on data units/MCU */
59 #endif
60 
61 
62 /* Data structures for images (arrays of samples and of DCT coefficients).
63  * On 80x86 machines, the image arrays are too big for near pointers,
64  * but the pointer arrays can fit in near memory.
65  */
66 
67 typedef JSAMPLE FAR *JSAMPROW;	/* ptr to one image row of pixel samples. */
68 typedef JSAMPROW *JSAMPARRAY;	/* ptr to some rows (a 2-D sample array) */
69 typedef JSAMPARRAY *JSAMPIMAGE;	/* a 3-D sample array: top index is color */
70 
71 typedef JCOEF JBLOCK[DCTSIZE2];	/* one block of coefficients */
72 typedef JBLOCK FAR *JBLOCKROW;	/* pointer to one row of coefficient blocks */
73 typedef JBLOCKROW *JBLOCKARRAY;		/* a 2-D array of coefficient blocks */
74 typedef JBLOCKARRAY *JBLOCKIMAGE;	/* a 3-D array of coefficient blocks */
75 
76 typedef JCOEF FAR *JCOEFPTR;	/* useful in a couple of places */
77 
78 typedef JDIFF FAR *JDIFFROW;	/* pointer to one row of difference values */
79 typedef JDIFFROW *JDIFFARRAY;	/* ptr to some rows (a 2-D diff array) */
80 typedef JDIFFARRAY *JDIFFIMAGE;	/* a 3-D diff array: top index is color */
81 
82 
83 /* Types for JPEG compression parameters and working tables. */
84 
85 
86 /* DCT coefficient quantization tables. */
87 
88 typedef struct {
89   /* This array gives the coefficient quantizers in natural array order
90    * (not the zigzag order in which they are stored in a JPEG DQT marker).
91    * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
92    */
93   UINT16 quantval[DCTSIZE2];	/* quantization step for each coefficient */
94   /* This field is used only during compression.  It's initialized FALSE when
95    * the table is created, and set TRUE when it's been output to the file.
96    * You could suppress output of a table by setting this to TRUE.
97    * (See jpeg_suppress_tables for an example.)
98    */
99   boolean sent_table;		/* TRUE when table has been output */
100 } JQUANT_TBL;
101 
102 
103 /* Huffman coding tables. */
104 
105 typedef struct {
106   /* These two fields directly represent the contents of a JPEG DHT marker */
107   UINT8 bits[17];		/* bits[k] = # of symbols with codes of */
108 				/* length k bits; bits[0] is unused */
109   UINT8 huffval[256];		/* The symbols, in order of incr code length */
110   /* This field is used only during compression.  It's initialized FALSE when
111    * the table is created, and set TRUE when it's been output to the file.
112    * You could suppress output of a table by setting this to TRUE.
113    * (See jpeg_suppress_tables for an example.)
114    */
115   boolean sent_table;		/* TRUE when table has been output */
116 } JHUFF_TBL;
117 
118 
119 /* Basic info about one component (color channel). */
120 
121 typedef struct {
122   /* These values are fixed over the whole image. */
123   /* For compression, they must be supplied by parameter setup; */
124   /* for decompression, they are read from the SOF marker. */
125   int component_id;		/* identifier for this component (0..255) */
126   int component_index;		/* its index in SOF or cinfo->comp_info[] */
127   int h_samp_factor;		/* horizontal sampling factor (1..4) */
128   int v_samp_factor;		/* vertical sampling factor (1..4) */
129   int quant_tbl_no;		/* quantization table selector (0..3) */
130   /* These values may vary between scans. */
131   /* For compression, they must be supplied by parameter setup; */
132   /* for decompression, they are read from the SOS marker. */
133   /* The decompressor output side may not use these variables. */
134   int dc_tbl_no;		/* DC entropy table selector (0..3) */
135   int ac_tbl_no;		/* AC entropy table selector (0..3) */
136 
137   /* Remaining fields should be treated as private by applications. */
138 
139   /* These values are computed during compression or decompression startup: */
140   /* Component's size in data units.
141    * Any dummy data units added to complete an MCU are not counted; therefore
142    * these values do not depend on whether a scan is interleaved or not.
143    */
144   JDIMENSION width_in_data_units;
145   JDIMENSION height_in_data_units;
146   /* Size of a data unit in/output by the codec (in samples).  Always
147    * data_unit for compression.  For decompression this is the size of the
148    * output from one data_unit, reflecting any processing performed by the
149    * codec.  For example, in the DCT-based codec, scaling may be applied
150    * during the IDCT step.  Values of 1,2,4,8 are likely to be supported.
151    * Note that different components may have different codec_data_unit sizes.
152    */
153   int codec_data_unit;
154   /* The downsampled dimensions are the component's actual, unpadded number
155    * of samples at the main buffer (preprocessing/compression interface), thus
156    * downsampled_width = ceil(image_width * Hi/Hmax)
157    * and similarly for height.  For decompression, codec-based processing is
158    * included (ie, IDCT scaling), so
159    * downsampled_width = ceil(image_width * Hi/Hmax * codec_data_unit/data_unit)
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 data units per MCU, horizontally */
172   int MCU_height;		/* number of data units per MCU, vertically */
173   int MCU_data_units;		/* MCU_width * MCU_height */
174   int MCU_sample_width;		/* MCU width in samples, MCU_width*codec_data_unit */
175   int last_col_width;		/* # of non-dummy data_units across in last MCU */
176   int last_row_height;		/* # of non-dummy data_units 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 
191 typedef 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 				   lossless JPEG predictor select parm (Ss) */
196   int Ah, Al;			/* progressive JPEG successive approx. parms
197 				   lossless JPEG point transform parm (Al) */
198 } jpeg_scan_info;
199 
200 /* The decompressor can save APPn and COM markers in a list of these: */
201 
202 typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr;
203 
204 struct jpeg_marker_struct {
205   jpeg_saved_marker_ptr next;	/* next in list, or NULL */
206   UINT8 marker;			/* marker code: JPEG_COM, or JPEG_APP0+n */
207   unsigned int original_length;	/* # bytes of data in the file */
208   unsigned int data_length;	/* # bytes of data saved at data[] */
209   JOCTET FAR * data;		/* the data contained in the marker */
210   /* the marker length word is not counted in data_length or original_length */
211 };
212 
213 /* Known codec processes. */
214 
215 typedef enum {
216 	JPROC_SEQUENTIAL,	/* baseline/extended sequential DCT */
217 	JPROC_PROGRESSIVE,	/* progressive DCT */
218 	JPROC_LOSSLESS		/* lossless (sequential) */
219 } J_CODEC_PROCESS;
220 
221 /* Known color spaces. */
222 
223 typedef enum {
224 	JCS_UNKNOWN,		/* error/unspecified */
225 	JCS_GRAYSCALE,		/* monochrome */
226 	JCS_RGB,		/* red/green/blue */
227 	JCS_YCbCr,		/* Y/Cb/Cr (also known as YUV) */
228 	JCS_CMYK,		/* C/M/Y/K */
229 	JCS_YCCK		/* Y/Cb/Cr/K */
230 } J_COLOR_SPACE;
231 
232 /* DCT/IDCT algorithm options. */
233 
234 typedef enum {
235 	JDCT_ISLOW,		/* slow but accurate integer algorithm */
236 	JDCT_IFAST,		/* faster, less accurate integer method */
237 	JDCT_FLOAT		/* floating-point: accurate, fast on fast HW */
238 } J_DCT_METHOD;
239 
240 #ifndef JDCT_DEFAULT		/* may be overridden in jconfig.h */
241 #define JDCT_DEFAULT  JDCT_ISLOW
242 #endif
243 #ifndef JDCT_FASTEST		/* may be overridden in jconfig.h */
244 #define JDCT_FASTEST  JDCT_IFAST
245 #endif
246 
247 /* Dithering options for decompression. */
248 
249 typedef enum {
250 	JDITHER_NONE,		/* no dithering */
251 	JDITHER_ORDERED,	/* simple ordered dither */
252 	JDITHER_FS		/* Floyd-Steinberg error diffusion dither */
253 } J_DITHER_MODE;
254 
255 
256 /* Common fields between JPEG compression and decompression master structs. */
257 
258 #define jpeg_common_fields \
259   struct jpeg_error_mgr * err;	/* Error handler module */\
260   struct jpeg_memory_mgr * mem;	/* Memory manager module */\
261   struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
262   void * client_data;		/* Available for use by application */\
263   boolean is_decompressor;	/* So common code can tell which is which */\
264   int global_state		/* For checking call sequence validity */
265 
266 /* Routines that are to be used by both halves of the library are declared
267  * to receive a pointer to this structure.  There are no actual instances of
268  * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
269  */
270 struct jpeg_common_struct {
271   jpeg_common_fields;		/* Fields common to both master struct types */
272   /* Additional fields follow in an actual jpeg_compress_struct or
273    * jpeg_decompress_struct.  All three structs must agree on these
274    * initial fields!  (This would be a lot cleaner in C++.)
275    */
276 };
277 
278 typedef struct jpeg_common_struct * j_common_ptr;
279 typedef struct jpeg_compress_struct * j_compress_ptr;
280 typedef struct jpeg_decompress_struct * j_decompress_ptr;
281 
282 
283 /* Master record for a compression instance */
284 
285 struct jpeg_compress_struct {
286   jpeg_common_fields;		/* Fields shared with jpeg_decompress_struct */
287 
288   /* Destination for compressed data */
289   struct jpeg_destination_mgr * dest;
290 
291   /* Description of source image --- these fields must be filled in by
292    * outer application before starting compression.  in_color_space must
293    * be correct before you can even call jpeg_set_defaults().
294    */
295 
296   JDIMENSION image_width;	/* input image width */
297   JDIMENSION image_height;	/* input image height */
298   int input_components;		/* # of color components in input image */
299   J_COLOR_SPACE in_color_space;	/* colorspace of input image */
300 
301   double input_gamma;		/* image gamma of input image */
302 
303   /* Compression parameters --- these fields must be set before calling
304    * jpeg_start_compress().  We recommend calling jpeg_set_defaults() to
305    * initialize everything to reasonable defaults, then changing anything
306    * the application specifically wants to change.  That way you won't get
307    * burnt when new parameters are added.  Also note that there are several
308    * helper routines to simplify changing parameters.
309    */
310 
311   boolean lossless;		/* TRUE=lossless encoding, FALSE=lossy */
312 
313   int data_precision;		/* bits of precision in image data */
314 
315   int num_components;		/* # of color components in JPEG image */
316   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
317 
318   jpeg_component_info * comp_info;
319   /* comp_info[i] describes component that appears i'th in SOF */
320 
321   JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
322   /* ptrs to coefficient quantization tables, or NULL if not defined */
323 
324   JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
325   JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
326   /* ptrs to Huffman coding tables, or NULL if not defined */
327 
328   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
329   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
330   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
331 
332   int num_scans;		/* # of entries in scan_info array */
333   const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */
334   /* The default value of scan_info is NULL, which causes a single-scan
335    * sequential JPEG file to be emitted.  To create a multi-scan file,
336    * set num_scans and scan_info to point to an array of scan definitions.
337    */
338 
339   boolean raw_data_in;		/* TRUE=caller supplies downsampled data */
340   boolean arith_code;		/* TRUE=arithmetic coding, FALSE=Huffman */
341   boolean optimize_coding;	/* TRUE=optimize entropy encoding parms */
342   boolean CCIR601_sampling;	/* TRUE=first samples are cosited */
343   int smoothing_factor;		/* 1..100, or 0 for no input smoothing */
344   J_DCT_METHOD dct_method;	/* DCT algorithm selector */
345 
346   /* The restart interval can be specified in absolute MCUs by setting
347    * restart_interval, or in MCU rows by setting restart_in_rows
348    * (in which case the correct restart_interval will be figured
349    * for each scan).
350    */
351   unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
352   int restart_in_rows;		/* if > 0, MCU rows per restart interval */
353 
354   /* Parameters controlling emission of special markers. */
355 
356   boolean write_JFIF_header;	/* should a JFIF marker be written? */
357   UINT8 JFIF_major_version;	/* What to write for the JFIF version number */
358   UINT8 JFIF_minor_version;
359   /* These three values are not used by the JPEG code, merely copied */
360   /* into the JFIF APP0 marker.  density_unit can be 0 for unknown, */
361   /* 1 for dots/inch, or 2 for dots/cm.  Note that the pixel aspect */
362   /* ratio is defined by X_density/Y_density even when density_unit=0. */
363   UINT8 density_unit;		/* JFIF code for pixel size units */
364   UINT16 X_density;		/* Horizontal pixel density */
365   UINT16 Y_density;		/* Vertical pixel density */
366   boolean write_Adobe_marker;	/* should an Adobe marker be written? */
367 
368   /* State variable: index of next scanline to be written to
369    * jpeg_write_scanlines().  Application may use this to control its
370    * processing loop, e.g., "while (next_scanline < image_height)".
371    */
372 
373   JDIMENSION next_scanline;	/* 0 .. image_height-1  */
374 
375   /* Remaining fields are known throughout compressor, but generally
376    * should not be touched by a surrounding application.
377    */
378 
379   /*
380    * These fields are computed during compression startup
381    */
382   int data_unit;		/* size of data unit in samples */
383   J_CODEC_PROCESS process;	/* encoding process of JPEG image */
384 
385   int max_h_samp_factor;	/* largest h_samp_factor */
386   int max_v_samp_factor;	/* largest v_samp_factor */
387 
388   JDIMENSION total_iMCU_rows;	/* # of iMCU rows to be input to codec */
389   /* The codec receives data in units of MCU rows as defined for fully
390    * interleaved scans (whether the JPEG file is interleaved or not).
391    * There are v_samp_factor * data_unit sample rows of each component in an
392    * "iMCU" (interleaved MCU) row.
393    */
394 
395   /*
396    * These fields are valid during any one scan.
397    * They describe the components and MCUs actually appearing in the scan.
398    */
399   int comps_in_scan;		/* # of JPEG components in this scan */
400   jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
401   /* *cur_comp_info[i] describes component that appears i'th in SOS */
402 
403   JDIMENSION MCUs_per_row;	/* # of MCUs across the image */
404   JDIMENSION MCU_rows_in_scan;	/* # of MCU rows in the image */
405 
406   int data_units_in_MCU;	/* # of data units per MCU */
407   int MCU_membership[C_MAX_DATA_UNITS_IN_MCU];
408   /* MCU_membership[i] is index in cur_comp_info of component owning */
409   /* i'th block in an MCU */
410 
411   int Ss, Se, Ah, Al;		/* progressive/lossless JPEG parameters for scan */
412 
413   /*
414    * Links to compression subobjects (methods and private variables of modules)
415    */
416   struct jpeg_comp_master * master;
417   struct jpeg_c_main_controller * main;
418   struct jpeg_c_prep_controller * prep;
419   struct jpeg_c_codec * codec;
420   struct jpeg_marker_writer * marker;
421   struct jpeg_color_converter * cconvert;
422   struct jpeg_downsampler * downsample;
423   jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */
424   int script_space_size;
425 
426   /* force the use of an extended sequential SOF1 marker even when a
427    * SOF0 marker could be used, to comply with DICOM CP 1447.
428    * This is only needed for 8 bits/sample. */
429   boolean force_extended_sequential_marker;
430 };
431 
432 
433 /* Master record for a decompression instance */
434 
435 struct jpeg_decompress_struct {
436   jpeg_common_fields;		/* Fields shared with jpeg_compress_struct */
437 
438   /* Source of compressed data */
439   struct jpeg_source_mgr * src;
440 
441   /* Basic description of image --- filled in by jpeg_read_header(). */
442   /* Application may inspect these values to decide how to process image. */
443 
444   JDIMENSION image_width;	/* nominal image width (from SOF marker) */
445   JDIMENSION image_height;	/* nominal image height */
446   int num_components;		/* # of color components in JPEG image */
447   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
448 
449   /* Decompression processing parameters --- these fields must be set before
450    * calling jpeg_start_decompress().  Note that jpeg_read_header() initializes
451    * them to default values.
452    */
453 
454   J_COLOR_SPACE out_color_space; /* colorspace for output */
455 
456   unsigned int scale_num, scale_denom; /* fraction by which to scale image */
457 
458   double output_gamma;		/* image gamma wanted in output */
459 
460   boolean buffered_image;	/* TRUE=multiple output passes */
461   boolean raw_data_out;		/* TRUE=downsampled data wanted */
462 
463   J_DCT_METHOD dct_method;	/* IDCT algorithm selector */
464   boolean do_fancy_upsampling;	/* TRUE=apply fancy upsampling */
465   boolean do_block_smoothing;	/* TRUE=apply interblock smoothing */
466 
467   boolean quantize_colors;	/* TRUE=colormapped output wanted */
468   /* the following are ignored if not quantize_colors: */
469   J_DITHER_MODE dither_mode;	/* type of color dithering to use */
470   boolean two_pass_quantize;	/* TRUE=use two-pass color quantization */
471   int desired_number_of_colors;	/* max # colors to use in created colormap */
472   /* these are significant only in buffered-image mode: */
473   boolean enable_1pass_quant;	/* enable future use of 1-pass quantizer */
474   boolean enable_external_quant;/* enable future use of external colormap */
475   boolean enable_2pass_quant;	/* enable future use of 2-pass quantizer */
476 
477   /* Description of actual output image that will be returned to application.
478    * These fields are computed by jpeg_start_decompress().
479    * You can also use jpeg_calc_output_dimensions() to determine these values
480    * in advance of calling jpeg_start_decompress().
481    */
482 
483   JDIMENSION output_width;	/* scaled image width */
484   JDIMENSION output_height;	/* scaled image height */
485   int out_color_components;	/* # of color components in out_color_space */
486   int output_components;	/* # of color components returned */
487   /* output_components is 1 (a colormap index) when quantizing colors;
488    * otherwise it equals out_color_components.
489    */
490   int rec_outbuf_height;	/* min recommended height of scanline buffer */
491   /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
492    * high, space and time will be wasted due to unnecessary data copying.
493    * Usually rec_outbuf_height will be 1 or 2, at most 4.
494    */
495 
496   /* When quantizing colors, the output colormap is described by these fields.
497    * The application can supply a colormap by setting colormap non-NULL before
498    * calling jpeg_start_decompress; otherwise a colormap is created during
499    * jpeg_start_decompress or jpeg_start_output.
500    * The map has out_color_components rows and actual_number_of_colors columns.
501    */
502   int actual_number_of_colors;	/* number of entries in use */
503   JSAMPARRAY colormap;		/* The color map as a 2-D pixel array */
504 
505   /* State variables: these variables indicate the progress of decompression.
506    * The application may examine these but must not modify them.
507    */
508 
509   /* Row index of next scanline to be read from jpeg_read_scanlines().
510    * Application may use this to control its processing loop, e.g.,
511    * "while (output_scanline < output_height)".
512    */
513   JDIMENSION output_scanline;	/* 0 .. output_height-1  */
514 
515   /* Current input scan number and number of iMCU rows completed in scan.
516    * These indicate the progress of the decompressor input side.
517    */
518   int input_scan_number;	/* Number of SOS markers seen so far */
519   JDIMENSION input_iMCU_row;	/* Number of iMCU rows completed */
520 
521   /* The "output scan number" is the notional scan being displayed by the
522    * output side.  The decompressor will not allow output scan/row number
523    * to get ahead of input scan/row, but it can fall arbitrarily far behind.
524    */
525   int output_scan_number;	/* Nominal scan number being displayed */
526   JDIMENSION output_iMCU_row;	/* Number of iMCU rows read */
527 
528   /* Current progression status.  coef_bits[c][i] indicates the precision
529    * with which component c's DCT coefficient i (in zigzag order) is known.
530    * It is -1 when no data has yet been received, otherwise it is the point
531    * transform (shift) value for the most recent scan of the coefficient
532    * (thus, 0 at completion of the progression).
533    * This pointer is NULL when reading a non-progressive file.
534    */
535   int (*coef_bits)[DCTSIZE2];	/* -1 or current Al value for each coef */
536 
537   /* Internal JPEG parameters --- the application usually need not look at
538    * these fields.  Note that the decompressor output side may not use
539    * any parameters that can change between scans.
540    */
541 
542   /* Quantization and Huffman tables are carried forward across input
543    * datastreams when processing abbreviated JPEG datastreams.
544    */
545 
546   JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
547   /* ptrs to coefficient quantization tables, or NULL if not defined */
548 
549   JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
550   JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
551   /* ptrs to Huffman coding tables, or NULL if not defined */
552 
553   /* These parameters are never carried across datastreams, since they
554    * are given in SOF/SOS markers or defined to be reset by SOI.
555    */
556 
557   int data_precision;		/* bits of precision in image data */
558 
559   jpeg_component_info * comp_info;
560   /* comp_info[i] describes component that appears i'th in SOF */
561 
562   boolean arith_code;		/* TRUE=arithmetic coding, FALSE=Huffman */
563 
564   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
565   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
566   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
567 
568   unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
569 
570   /* These fields record data obtained from optional markers recognized by
571    * the JPEG library.
572    */
573   boolean saw_JFIF_marker;	/* TRUE iff a JFIF APP0 marker was found */
574   /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
575   UINT8 JFIF_major_version;	/* JFIF version number */
576   UINT8 JFIF_minor_version;
577   UINT8 density_unit;		/* JFIF code for pixel size units */
578   UINT16 X_density;		/* Horizontal pixel density */
579   UINT16 Y_density;		/* Vertical pixel density */
580   boolean saw_Adobe_marker;	/* TRUE iff an Adobe APP14 marker was found */
581   UINT8 Adobe_transform;	/* Color transform code from Adobe marker */
582 
583   boolean CCIR601_sampling;	/* TRUE=first samples are cosited */
584 
585   /* Aside from the specific data retained from APPn markers known to the
586    * library, the uninterpreted contents of any or all APPn and COM markers
587    * can be saved in a list for examination by the application.
588    */
589   jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
590 
591   /* Remaining fields are known throughout decompressor, but generally
592    * should not be touched by a surrounding application.
593    */
594 
595   /*
596    * These fields are computed during decompression startup
597    */
598   int data_unit;		/* size of data unit in samples */
599   J_CODEC_PROCESS process;	/* decoding process of JPEG image */
600 
601   int max_h_samp_factor;	/* largest h_samp_factor */
602   int max_v_samp_factor;	/* largest v_samp_factor */
603 
604   int min_codec_data_unit;	/* smallest codec_data_unit of any component */
605 
606   JDIMENSION total_iMCU_rows;	/* # of iMCU rows in image */
607   /* The codec's input and output progress is measured in units of "iMCU"
608    * (interleaved MCU) rows.  These are the same as MCU rows in fully
609    * interleaved JPEG scans, but are used whether the scan is interleaved
610    * or not.  We define an iMCU row as v_samp_factor data_unit rows of each
611    * component.  Therefore, the codec output contains
612    * v_samp_factor*codec_data_unit 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 data_units_in_MCU;	/* # of data _units per MCU */
630   int MCU_membership[D_MAX_DATA_UNITS_IN_MCU];
631   /* MCU_membership[i] is index in cur_comp_info of component owning */
632   /* i'th data unit in an MCU */
633 
634   int Ss, Se, Ah, Al;		/* progressive/lossless JPEG parms 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_codec * codec;
648   struct jpeg_d_post_controller * post;
649   struct jpeg_input_controller * inputctl;
650   struct jpeg_marker_reader * marker;
651   struct jpeg_upsampler * upsample;
652   struct jpeg_color_deconverter * cconvert;
653   struct jpeg_color_quantizer * cquantize;
654 
655   /* Options that enable or disable various workarounds */
656   unsigned int workaround_options;
657 };
658 
659 /* constants for workaround_options in struct jpeg_decompress_struct */
660 #define WORKAROUND_PREDICTOR6OVERFLOW 1
661 #define WORKAROUND_BUGGY_CORNELL_16BIT_JPEG_ENCODER 2
662 
663 /* "Object" declarations for JPEG modules that may be supplied or called
664  * directly by the surrounding application.
665  * As with all objects in the JPEG library, these structs only define the
666  * publicly visible methods and state variables of a module.  Additional
667  * private fields may exist after the public ones.
668  */
669 
670 
671 /* Error handler object */
672 
673 struct jpeg_error_mgr {
674   /* Error exit handler: does not return to caller */
675   JMETHOD(void, error_exit, (j_common_ptr cinfo));
676   /* Conditionally emit a trace or warning message */
677   JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
678   /* Routine that actually outputs a trace or error message */
679   JMETHOD(void, output_message, (j_common_ptr cinfo));
680   /* Format a message string for the most recent JPEG error or message */
681   JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
682 #define JMSG_LENGTH_MAX  200	/* recommended size of format_message buffer */
683   /* Reset error state variables at start of a new image */
684   JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
685 
686   /* The message ID code and any parameters are saved here.
687    * A message can have one string parameter or up to 8 int parameters.
688    */
689   int msg_code;
690 #define JMSG_STR_PARM_MAX  80
691   union {
692     int i[8];
693     char s[JMSG_STR_PARM_MAX];
694   } msg_parm;
695 
696   /* Standard state variables for error facility */
697 
698   int trace_level;		/* max msg_level that will be displayed */
699 
700   /* For recoverable corrupt-data errors, we emit a warning message,
701    * but keep going unless emit_message chooses to abort.  emit_message
702    * should count warnings in num_warnings.  The surrounding application
703    * can check for bad data by seeing if num_warnings is nonzero at the
704    * end of processing.
705    */
706   long num_warnings;		/* number of corrupt-data warnings */
707 
708   /* These fields point to the table(s) of error message strings.
709    * An application can change the table pointer to switch to a different
710    * message list (typically, to change the language in which errors are
711    * reported).  Some applications may wish to add additional error codes
712    * that will be handled by the JPEG library error mechanism; the second
713    * table pointer is used for this purpose.
714    *
715    * First table includes all errors generated by JPEG library itself.
716    * Error code 0 is reserved for a "no such error string" message.
717    */
718   const char * const * jpeg_message_table; /* Library errors */
719   int last_jpeg_message;    /* Table contains strings 0..last_jpeg_message */
720   /* Second table can be added by application (see cjpeg/djpeg for example).
721    * It contains strings numbered first_addon_message..last_addon_message.
722    */
723   const char * const * addon_message_table; /* Non-library errors */
724   int first_addon_message;	/* code for first string in addon table */
725   int last_addon_message;	/* code for last string in addon table */
726 };
727 
728 
729 /* Progress monitor object */
730 
731 struct jpeg_progress_mgr {
732   JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
733 
734   long pass_counter;		/* work units completed in this pass */
735   long pass_limit;		/* total number of work units in this pass */
736   int completed_passes;		/* passes completed so far */
737   int total_passes;		/* total number of passes expected */
738 };
739 
740 
741 /* Data destination object for compression */
742 
743 struct jpeg_destination_mgr {
744   JOCTET * next_output_byte;	/* => next byte to write in buffer */
745   size_t free_in_buffer;	/* # of byte spaces remaining in buffer */
746 
747   JMETHOD(void, init_destination, (j_compress_ptr cinfo));
748   JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
749   JMETHOD(void, term_destination, (j_compress_ptr cinfo));
750 };
751 
752 
753 /* Data source object for decompression */
754 
755 struct jpeg_source_mgr {
756   const JOCTET * next_input_byte; /* => next byte to read from buffer */
757   size_t bytes_in_buffer;	/* # of bytes remaining in buffer */
758 
759   JMETHOD(void, init_source, (j_decompress_ptr cinfo));
760   JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
761   JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
762   JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
763   JMETHOD(void, term_source, (j_decompress_ptr cinfo));
764 };
765 
766 
767 /* Memory manager object.
768  * Allocates "small" objects (a few K total), "large" objects (tens of K),
769  * and "really big" objects (virtual arrays with backing store if needed).
770  * The memory manager does not allow individual objects to be freed; rather,
771  * each created object is assigned to a pool, and whole pools can be freed
772  * at once.  This is faster and more convenient than remembering exactly what
773  * to free, especially where malloc()/free() are not too speedy.
774  * NB: alloc routines never return NULL.  They exit to error_exit if not
775  * successful.
776  */
777 
778 #define JPOOL_PERMANENT	0	/* lasts until master record is destroyed */
779 #define JPOOL_IMAGE	1	/* lasts until done with image/datastream */
780 #define JPOOL_NUMPOOLS	2
781 
782 typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
783 typedef struct jvirt_barray_control * jvirt_barray_ptr;
784 
785 
786 #ifdef C_LOSSLESS_SUPPORTED
787 #define NEED_DARRAY
788 #else
789 #ifdef D_LOSSLESS_SUPPORTED
790 #define NEED_DARRAY
791 #endif
792 #endif
793 
794 struct jpeg_memory_mgr {
795   /* Method pointers */
796   JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
797 				size_t sizeofobject));
798   JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
799 				     size_t sizeofobject));
800   JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
801 				     JDIMENSION samplesperrow,
802 				     JDIMENSION numrows));
803   JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
804 				      JDIMENSION blocksperrow,
805 				      JDIMENSION numrows));
806 #ifdef NEED_DARRAY
807   JMETHOD(JDIFFARRAY, alloc_darray, (j_common_ptr cinfo, int pool_id,
808 				     JDIMENSION diffsperrow,
809 				     JDIMENSION numrows));
810 #endif
811   JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
812 						  int pool_id,
813 						  boolean pre_zero,
814 						  JDIMENSION samplesperrow,
815 						  JDIMENSION numrows,
816 						  JDIMENSION maxaccess));
817   JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
818 						  int pool_id,
819 						  boolean pre_zero,
820 						  JDIMENSION blocksperrow,
821 						  JDIMENSION numrows,
822 						  JDIMENSION maxaccess));
823   JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
824   JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
825 					   jvirt_sarray_ptr ptr,
826 					   JDIMENSION start_row,
827 					   JDIMENSION num_rows,
828 					   boolean writable));
829   JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
830 					    jvirt_barray_ptr ptr,
831 					    JDIMENSION start_row,
832 					    JDIMENSION num_rows,
833 					    boolean writable));
834   JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
835   JMETHOD(void, self_destruct, (j_common_ptr cinfo));
836 
837   /* Limit on memory allocation for this JPEG object.  (Note that this is
838    * merely advisory, not a guaranteed maximum; it only affects the space
839    * used for virtual-array buffers.)  May be changed by outer application
840    * after creating the JPEG object.
841    */
842   long max_memory_to_use;
843 
844   /* Maximum allocation request accepted by alloc_large. */
845   long max_alloc_chunk;
846 };
847 
848 
849 /* Routine signature for application-supplied marker processing methods.
850  * Need not pass marker code since it is stored in cinfo->unread_marker.
851  */
852 typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
853 
854 
855 /* Declarations for routines called by application.
856  * The JPP macro hides prototype parameters from compilers that can't cope.
857  * Note JPP requires double parentheses.
858  */
859 
860 #ifdef HAVE_PROTOTYPES
861 #define JPP(arglist)	arglist
862 #else
863 #define JPP(arglist)	()
864 #endif
865 
866 
867 /* Short forms of external names for systems with brain-damaged linkers.
868  * We shorten external names to be unique in the first six letters, which
869  * is good enough for all known systems.
870  * (If your compiler itself needs names to be unique in less than 15
871  * characters, you are out of luck.  Get a better compiler.)
872  */
873 
874 /* MAKE SURE THAT ALL FUNCTIONS DECLARED GLOBAL() ARE RE-DEFINED HERE! */
875 
876 #ifdef NEED_SHORT_EXTERNAL_NAMES
877 #define jcopy_block_row                jcopy16_block_row
878 #define jcopy_sample_rows              jcopy16_sample_rows
879 #define jdiv_round_up                  jdiv16_round_up
880 #define jinit_1pass_quantizer          jinit16_1pass_quantizer
881 #define jinit_2pass_quantizer          jinit16_2pass_quantizer
882 #define jinit_arith_decoder            jinit16_arith_decoder
883 #define jinit_arith_encoder            jinit16_arith_encoder
884 #define jinit_c_codec                  jinit16_c_codec
885 #define jinit_c_coef_controller        jinit16_c_coef_controller
886 #define jinit_c_diff_controller        jinit16_c_diff_controller
887 #define jinit_c_main_controller        jinit16_c_main_controller
888 #define jinit_c_master_control         jinit16_c_master_control
889 #define jinit_c_prep_controller        jinit16_c_prep_controller
890 #define jinit_c_scaler                 jinit16_c_scaler
891 #define jinit_color_converter          jinit16_color_converter
892 #define jinit_color_deconverter        jinit16_color_deconverter
893 #define jinit_compress_master          jinit16_compress_master
894 #define jinit_d_codec                  jinit16_d_codec
895 #define jinit_d_coef_controller        jinit16_d_coef_controller
896 #define jinit_d_diff_controller        jinit16_d_diff_controller
897 #define jinit_d_main_controller        jinit16_d_main_controller
898 #define jinit_d_post_controller        jinit16_d_post_controller
899 #define jinit_d_post_controller        jinit16_d_post_controller
900 #define jinit_d_scaler                 jinit16_d_scaler
901 #define jinit_differencer              jinit16_differencer
902 #define jinit_downsampler              jinit16_downsampler
903 #define jinit_forward_dct              jinit16_forward_dct
904 #define jinit_input_controller         jinit16_input_controller
905 #define jinit_inverse_dct              jinit16_inverse_dct
906 #define jinit_lhuff_decoder            jinit16_lhuff_decoder
907 #define jinit_lhuff_encoder            jinit16_lhuff_encoder
908 #define jinit_lossless_c_codec         jinit16_lossless_c_codec
909 #define jinit_lossless_d_codec         jinit16_lossless_d_codec
910 #define jinit_lossy_c_codec            jinit16_lossy_c_codec
911 #define jinit_lossy_d_codec            jinit16_lossy_d_codec
912 #define jinit_marker_reader            jinit16_marker_reader
913 #define jinit_marker_writer            jinit16_marker_writer
914 #define jinit_master_decompress        jinit16_master_decompress
915 #define jinit_memory_mgr               jinit16_memory_mgr
916 #define jinit_merged_upsampler         jinit16_merged_upsampler
917 #define jinit_phuff_decoder            jinit16_phuff_decoder
918 #define jinit_phuff_encoder            jinit16_phuff_encoder
919 #define jinit_shuff_decoder            jinit16_shuff_decoder
920 #define jinit_shuff_encoder            jinit16_shuff_encoder
921 #define jinit_undifferencer            jinit16_undifferencer
922 #define jinit_upsampler                jinit16_upsampler
923 #define jpeg_CreateCompress            jpeg16_CreateCompress
924 #define jpeg_CreateDecompress          jpeg16_CreateDecompress
925 #define jpeg_abort                     jpeg16_abort
926 #define jpeg_abort_compress            jpeg16_abort_compress
927 #define jpeg_abort_decompress          jpeg16_abort_decompress
928 #define jpeg_add_quant_table           jpeg16_add_quant_table
929 #define jpeg_alloc_huff_table          jpeg16_alloc_huff_table
930 #define jpeg_alloc_quant_table         jpeg16_alloc_quant_table
931 #define jpeg_calc_output_dimensions    jpeg16_calc_output_dimensions
932 #define jpeg_consume_input             jpeg16_consume_input
933 #define jpeg_copy_critical_parameters  jpeg16_copy_critical_parameters
934 #define jpeg_default_colorspace        jpeg16_default_colorspace
935 #define jpeg_destroy                   jpeg16_destroy
936 #define jpeg_destroy_compress          jpeg16_destroy_compress
937 #define jpeg_destroy_decompress        jpeg16_destroy_decompress
938 #define jpeg_fdct_float                jpeg16_fdct_float
939 #define jpeg_fdct_ifast                jpeg16_fdct_ifast
940 #define jpeg_fdct_islow                jpeg16_fdct_islow
941 #define jpeg_fill_bit_buffer           jpeg16_fill_bit_buffer
942 #define jpeg_finish_compress           jpeg16_finish_compress
943 #define jpeg_finish_decompress         jpeg16_finish_decompress
944 #define jpeg_finish_output             jpeg16_finish_output
945 #define jpeg_free_large                jpeg16_free_large
946 #define jpeg_free_small                jpeg16_free_small
947 #define jpeg_gen_optimal_table         jpeg16_gen_optimal_table
948 #define jpeg_get_large                 jpeg16_get_large
949 #define jpeg_get_small                 jpeg16_get_small
950 #define jpeg_has_multiple_scans        jpeg16_has_multiple_scans
951 #define jpeg_huff_decode               jpeg16_huff_decode
952 #define jpeg_idct_1x1                  jpeg16_idct_1x1
953 #define jpeg_idct_2x2                  jpeg16_idct_2x2
954 #define jpeg_idct_4x4                  jpeg16_idct_4x4
955 #define jpeg_idct_float                jpeg16_idct_float
956 #define jpeg_idct_ifast                jpeg16_idct_ifast
957 #define jpeg_idct_islow                jpeg16_idct_islow
958 #define jpeg_input_complete            jpeg16_input_complete
959 #define jpeg_make_c_derived_tbl        jpeg16_make_c_derived_tbl
960 #define jpeg_make_d_derived_tbl        jpeg16_make_d_derived_tbl
961 #define jpeg_mem_available             jpeg16_mem_available
962 #define jpeg_mem_init                  jpeg16_mem_init
963 #define jpeg_mem_term                  jpeg16_mem_term
964 #define jpeg_new_colormap              jpeg16_new_colormap
965 #define jpeg_open_backing_store        jpeg16_open_backing_store
966 #define jpeg_quality_scaling           jpeg16_quality_scaling
967 #define jpeg_read_coefficients         jpeg16_read_coefficients
968 #define jpeg_read_header               jpeg16_read_header
969 #define jpeg_read_raw_data             jpeg16_read_raw_data
970 #define jpeg_read_scanlines            jpeg16_read_scanlines
971 #define jpeg_resync_to_restart         jpeg16_resync_to_restart
972 #define jpeg_save_markers              jpeg16_save_markers
973 #define jpeg_set_colorspace            jpeg16_set_colorspace
974 #define jpeg_set_defaults              jpeg16_set_defaults
975 #define jpeg_set_linear_quality        jpeg16_set_linear_quality
976 #define jpeg_set_marker_processor      jpeg16_set_marker_processor
977 #define jpeg_set_quality               jpeg16_set_quality
978 #define jpeg_simple_lossless           jpeg16_simple_lossless
979 #define jpeg_simple_progression        jpeg16_simple_progression
980 #define jpeg_start_compress            jpeg16_start_compress
981 #define jpeg_start_decompress          jpeg16_start_decompress
982 #define jpeg_start_output              jpeg16_start_output
983 #define jpeg_std_error                 jpeg16_std_error
984 #define jpeg_stdio_dest                jpeg16_stdio_dest
985 #define jpeg_stdio_src                 jpeg16_stdio_src
986 #define jpeg_suppress_tables           jpeg16_suppress_tables
987 #define jpeg_write_coefficients        jpeg16_write_coefficients
988 #define jpeg_write_m_byte              jpeg16_write_m_byte
989 #define jpeg_write_m_header            jpeg16_write_m_header
990 #define jpeg_write_marker              jpeg16_write_marker
991 #define jpeg_write_raw_data            jpeg16_write_raw_data
992 #define jpeg_write_scanlines           jpeg16_write_scanlines
993 #define jpeg_write_tables              jpeg16_write_tables
994 #define jround_up                      jround16_up
995 #define jzero_far                      jzero16_far
996 #endif /* NEED_SHORT_EXTERNAL_NAMES */
997 
998 
999 /* Default error-management setup */
1000 EXTERN(struct jpeg_error_mgr *) jpeg_std_error
1001 	JPP((struct jpeg_error_mgr * err));
1002 
1003 /* Initialization of JPEG compression objects.
1004  * jpeg_create_compress() and jpeg_create_decompress() are the exported
1005  * names that applications should call.  These expand to calls on
1006  * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
1007  * passed for version mismatch checking.
1008  * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
1009  */
1010 #define jpeg_create_compress(cinfo) \
1011     jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
1012 			(size_t) sizeof(struct jpeg_compress_struct))
1013 #define jpeg_create_decompress(cinfo) \
1014     jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
1015 			  (size_t) sizeof(struct jpeg_decompress_struct))
1016 EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo,
1017 				      int version, size_t structsize));
1018 EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo,
1019 					int version, size_t structsize));
1020 /* Destruction of JPEG compression objects */
1021 EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo));
1022 EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
1023 
1024 /* Standard data source and destination managers: stdio streams. */
1025 /* Caller is responsible for opening the file before and closing after. */
1026 EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
1027 EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile));
1028 
1029 /* Default parameter setup for compression */
1030 EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo));
1031 /* Compression parameter setup aids */
1032 EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo,
1033 				      J_COLOR_SPACE colorspace));
1034 EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo));
1035 EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
1036 				   boolean force_baseline));
1037 EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
1038 					  int scale_factor,
1039 					  boolean force_baseline));
1040 EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
1041 				       const unsigned int *basic_table,
1042 				       int scale_factor,
1043 				       boolean force_baseline));
1044 EXTERN(int) jpeg_quality_scaling JPP((int quality));
1045 EXTERN(void) jpeg_simple_lossless JPP((j_compress_ptr cinfo,
1046 				       int predictor, int point_transform));
1047 EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo));
1048 EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo,
1049 				       boolean suppress));
1050 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo));
1051 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo));
1052 
1053 /* Main entry points for compression */
1054 EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo,
1055 				      boolean write_all_tables));
1056 EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo,
1057 					     JSAMPARRAY scanlines,
1058 					     JDIMENSION num_lines));
1059 EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo));
1060 
1061 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
1062 EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo,
1063 					    JSAMPIMAGE data,
1064 					    JDIMENSION num_lines));
1065 
1066 /* Write a special marker.  See libjpeg.doc concerning safe usage. */
1067 EXTERN(void) jpeg_write_marker
1068 	JPP((j_compress_ptr cinfo, int marker,
1069 	     const JOCTET * dataptr, unsigned int datalen));
1070 /* Same, but piecemeal. */
1071 EXTERN(void) jpeg_write_m_header
1072 	JPP((j_compress_ptr cinfo, int marker, unsigned int datalen));
1073 EXTERN(void) jpeg_write_m_byte
1074 	JPP((j_compress_ptr cinfo, int val));
1075 
1076 /* Alternate compression function: just write an abbreviated table file */
1077 EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo));
1078 
1079 /* Decompression startup: read start of JPEG datastream to see what's there */
1080 EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo,
1081 				  boolean require_image));
1082 /* Return value is one of: */
1083 #define JPEG_SUSPENDED		0 /* Suspended due to lack of input data */
1084 #define JPEG_HEADER_OK		1 /* Found valid image datastream */
1085 #define JPEG_HEADER_TABLES_ONLY	2 /* Found valid table-specs-only datastream */
1086 /* If you pass require_image = TRUE (normal case), you need not check for
1087  * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
1088  * JPEG_SUSPENDED is only possible if you use a data source module that can
1089  * give a suspension return (the stdio source module doesn't).
1090  */
1091 
1092 /* Main entry points for decompression */
1093 EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo));
1094 EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
1095 					    JSAMPARRAY scanlines,
1096 					    JDIMENSION max_lines));
1097 EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
1098 
1099 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
1100 EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
1101 					   JSAMPIMAGE data,
1102 					   JDIMENSION max_lines));
1103 
1104 /* Additional entry points for buffered-image mode. */
1105 EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
1106 EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo,
1107 				       int scan_number));
1108 EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo));
1109 EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo));
1110 EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo));
1111 EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo));
1112 /* Return value is one of: */
1113 /* #define JPEG_SUSPENDED	0    Suspended due to lack of input data */
1114 #define JPEG_REACHED_SOS	1 /* Reached start of new scan */
1115 #define JPEG_REACHED_EOI	2 /* Reached end of image */
1116 #define JPEG_ROW_COMPLETED	3 /* Completed one iMCU row */
1117 #define JPEG_SCAN_COMPLETED	4 /* Completed last iMCU row of a scan */
1118 
1119 /* Precalculate output dimensions for current decompression parameters. */
1120 EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo));
1121 
1122 /* Control saving of COM and APPn markers into marker_list. */
1123 EXTERN(void) jpeg_save_markers
1124 	JPP((j_decompress_ptr cinfo, int marker_code,
1125 	     unsigned int length_limit));
1126 
1127 /* Install a special processing method for COM or APPn markers. */
1128 EXTERN(void) jpeg_set_marker_processor
1129 	JPP((j_decompress_ptr cinfo, int marker_code,
1130 	     jpeg_marker_parser_method routine));
1131 
1132 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
1133 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo));
1134 EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo,
1135 					  jvirt_barray_ptr * coef_arrays));
1136 EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo,
1137 						j_compress_ptr dstinfo));
1138 
1139 /* If you choose to abort compression or decompression before completing
1140  * jpeg_finish_(de)compress, then you need to clean up to release memory,
1141  * temporary files, etc.  You can just call jpeg_destroy_(de)compress
1142  * if you're done with the JPEG object, but if you want to clean it up and
1143  * reuse it, call this:
1144  */
1145 EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo));
1146 EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo));
1147 
1148 /* Generic versions of jpeg_abort and jpeg_destroy that work on either
1149  * flavor of JPEG object.  These may be more convenient in some places.
1150  */
1151 EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo));
1152 EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo));
1153 
1154 /* Default restart-marker-resync procedure for use by data source modules */
1155 EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo,
1156 					    int desired));
1157 
1158 
1159 /* These marker codes are exported since applications and data source modules
1160  * are likely to want to use them.
1161  */
1162 
1163 #define JPEG_RST0	0xD0	/* RST0 marker code */
1164 #define JPEG_EOI	0xD9	/* EOI marker code */
1165 #define JPEG_APP0	0xE0	/* APP0 marker code */
1166 #define JPEG_COM	0xFE	/* COM marker code */
1167 
1168 
1169 /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1170  * for structure definitions that are never filled in, keep it quiet by
1171  * supplying dummy definitions for the various substructures.
1172  */
1173 
1174 #ifdef INCOMPLETE_TYPES_BROKEN
1175 #ifndef JPEG_INTERNALS		/* will be defined in jpegint.h */
1176 struct jvirt_sarray_control { long dummy; };
1177 struct jvirt_barray_control { long dummy; };
1178 struct jpeg_comp_master { long dummy; };
1179 struct jpeg_c_main_controller { long dummy; };
1180 struct jpeg_c_prep_controller { long dummy; };
1181 struct jpeg_c_coef_controller { long dummy; };
1182 struct jpeg_marker_writer { long dummy; };
1183 struct jpeg_color_converter { long dummy; };
1184 struct jpeg_downsampler { long dummy; };
1185 struct jpeg_forward_dct { long dummy; };
1186 struct jpeg_entropy_encoder { long dummy; };
1187 struct jpeg_decomp_master { long dummy; };
1188 struct jpeg_d_main_controller { long dummy; };
1189 struct jpeg_d_coef_controller { long dummy; };
1190 struct jpeg_d_post_controller { long dummy; };
1191 struct jpeg_input_controller { long dummy; };
1192 struct jpeg_marker_reader { long dummy; };
1193 struct jpeg_entropy_decoder { long dummy; };
1194 struct jpeg_inverse_dct { long dummy; };
1195 struct jpeg_upsampler { long dummy; };
1196 struct jpeg_color_deconverter { long dummy; };
1197 struct jpeg_color_quantizer { long dummy; };
1198 #endif /* JPEG_INTERNALS */
1199 #endif /* INCOMPLETE_TYPES_BROKEN */
1200 
1201 
1202 /*
1203  * The JPEG library modules define JPEG_INTERNALS before including this file.
1204  * The internal structure declarations are read only when that is true.
1205  * Applications using the library should not include jpegint.h, but may wish
1206  * to include jerror.h.
1207  */
1208 
1209 #ifdef JPEG_INTERNALS
1210 #include "jpegint16.h"		/* fetch private declarations */
1211 #include "jerror16.h"		/* fetch error codes too */
1212 #endif
1213 
1214 #endif /* JPEGLIB_H */
1215