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1 /*
2  * jpeglib.h
3  *
4  * This file was part of the Independent JPEG Group's software:
5  * Copyright (C) 1991-1998, Thomas G. Lane.
6  * Modified 2002-2009 by Guido Vollbeding.
7  * libjpeg-turbo Modifications:
8  * Copyright (C) 2009-2011, 2013-2014, 2016-2017, 2020, D. R. Commander.
9  * Copyright (C) 2015, Google, Inc.
10  * For conditions of distribution and use, see the accompanying README.ijg
11  * file.
12  *
13  * This file defines the application interface for the JPEG library.
14  * Most applications using the library need only include this file,
15  * and perhaps jerror.h if they want to know the exact error codes.
16  */
17 
18 #ifndef JPEGLIB_H
19 #define JPEGLIB_H
20 
21 /* Begin chromium edits */
22 #ifdef HAS_CHROMIUM
23 #include "jpeglibmangler.h"
24 #endif
25 /* End chromium edits */
26 
27 /*
28  * First we include the configuration files that record how this
29  * installation of the JPEG library is set up.  jconfig.h can be
30  * generated automatically for many systems.  jmorecfg.h contains
31  * manual configuration options that most people need not worry about.
32  */
33 
34 #ifndef JCONFIG_INCLUDED        /* in case jinclude.h already did */
35 #include "jconfig.h"            /* widely used configuration options */
36 #endif
37 #include "jmorecfg.h"           /* seldom changed options */
38 
39 
40 #ifdef __cplusplus
41 #ifndef DONT_USE_EXTERN_C
42 extern "C" {
43 #endif
44 #endif
45 
46 
47 /* Various constants determining the sizes of things.
48  * All of these are specified by the JPEG standard, so don't change them
49  * if you want to be compatible.
50  */
51 
52 #define DCTSIZE             8   /* The basic DCT block is 8x8 samples */
53 #define DCTSIZE2            64  /* DCTSIZE squared; # of elements in a block */
54 #define NUM_QUANT_TBLS      4   /* Quantization tables are numbered 0..3 */
55 #define NUM_HUFF_TBLS       4   /* Huffman tables are numbered 0..3 */
56 #define NUM_ARITH_TBLS      16  /* Arith-coding tables are numbered 0..15 */
57 #define MAX_COMPS_IN_SCAN   4   /* JPEG limit on # of components in one scan */
58 #define MAX_SAMP_FACTOR     4   /* JPEG limit on sampling factors */
59 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
60  * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
61  * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
62  * to handle it.  We even let you do this from the jconfig.h file.  However,
63  * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
64  * sometimes emits noncompliant files doesn't mean you should too.
65  */
66 #define C_MAX_BLOCKS_IN_MCU   10 /* compressor's limit on blocks per MCU */
67 #ifndef D_MAX_BLOCKS_IN_MCU
68 #define D_MAX_BLOCKS_IN_MCU   10 /* decompressor's limit on blocks per MCU */
69 #endif
70 
71 
72 /* Data structures for images (arrays of samples and of DCT coefficients).
73  */
74 
75 typedef JSAMPLE *JSAMPROW;      /* ptr to one image row of pixel samples. */
76 typedef JSAMPROW *JSAMPARRAY;   /* ptr to some rows (a 2-D sample array) */
77 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
78 
79 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
80 typedef JBLOCK *JBLOCKROW;      /* pointer to one row of coefficient blocks */
81 typedef JBLOCKROW *JBLOCKARRAY;         /* a 2-D array of coefficient blocks */
82 typedef JBLOCKARRAY *JBLOCKIMAGE;       /* a 3-D array of coefficient blocks */
83 
84 typedef JCOEF *JCOEFPTR;        /* useful in a couple of places */
85 
86 
87 /* Types for JPEG compression parameters and working tables. */
88 
89 
90 /* DCT coefficient quantization tables. */
91 
92 typedef struct {
93   /* This array gives the coefficient quantizers in natural array order
94    * (not the zigzag order in which they are stored in a JPEG DQT marker).
95    * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
96    */
97   UINT16 quantval[DCTSIZE2];    /* quantization step for each coefficient */
98   /* This field is used only during compression.  It's initialized FALSE when
99    * the table is created, and set TRUE when it's been output to the file.
100    * You could suppress output of a table by setting this to TRUE.
101    * (See jpeg_suppress_tables for an example.)
102    */
103   boolean sent_table;           /* TRUE when table has been output */
104 } JQUANT_TBL;
105 
106 
107 /* Huffman coding tables. */
108 
109 typedef struct {
110   /* These two fields directly represent the contents of a JPEG DHT marker */
111   UINT8 bits[17];               /* bits[k] = # of symbols with codes of */
112                                 /* length k bits; bits[0] is unused */
113   UINT8 huffval[256];           /* The symbols, in order of incr code length */
114   /* This field is used only during compression.  It's initialized FALSE when
115    * the table is created, and set TRUE when it's been output to the file.
116    * You could suppress output of a table by setting this to TRUE.
117    * (See jpeg_suppress_tables for an example.)
118    */
119   boolean sent_table;           /* TRUE when table has been output */
120 } JHUFF_TBL;
121 
122 
123 /* Basic info about one component (color channel). */
124 
125 typedef struct {
126   /* These values are fixed over the whole image. */
127   /* For compression, they must be supplied by parameter setup; */
128   /* for decompression, they are read from the SOF marker. */
129   int component_id;             /* identifier for this component (0..255) */
130   int component_index;          /* its index in SOF or cinfo->comp_info[] */
131   int h_samp_factor;            /* horizontal sampling factor (1..4) */
132   int v_samp_factor;            /* vertical sampling factor (1..4) */
133   int quant_tbl_no;             /* quantization table selector (0..3) */
134   /* These values may vary between scans. */
135   /* For compression, they must be supplied by parameter setup; */
136   /* for decompression, they are read from the SOS marker. */
137   /* The decompressor output side may not use these variables. */
138   int dc_tbl_no;                /* DC entropy table selector (0..3) */
139   int ac_tbl_no;                /* AC entropy table selector (0..3) */
140 
141   /* Remaining fields should be treated as private by applications. */
142 
143   /* These values are computed during compression or decompression startup: */
144   /* Component's size in DCT blocks.
145    * Any dummy blocks added to complete an MCU are not counted; therefore
146    * these values do not depend on whether a scan is interleaved or not.
147    */
148   JDIMENSION width_in_blocks;
149   JDIMENSION height_in_blocks;
150   /* Size of a DCT block in samples.  Always DCTSIZE for compression.
151    * For decompression this is the size of the output from one DCT block,
152    * reflecting any scaling we choose to apply during the IDCT step.
153    * Values from 1 to 16 are supported.
154    * Note that different components may receive different IDCT scalings.
155    */
156 #if JPEG_LIB_VERSION >= 70
157   int DCT_h_scaled_size;
158   int DCT_v_scaled_size;
159 #else
160   int DCT_scaled_size;
161 #endif
162   /* The downsampled dimensions are the component's actual, unpadded number
163    * of samples at the main buffer (preprocessing/compression interface), thus
164    * downsampled_width = ceil(image_width * Hi/Hmax)
165    * and similarly for height.  For decompression, IDCT scaling is included, so
166    * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]scaled_size/DCTSIZE)
167    */
168   JDIMENSION downsampled_width;  /* actual width in samples */
169   JDIMENSION downsampled_height; /* actual height in samples */
170   /* This flag is used only for decompression.  In cases where some of the
171    * components will be ignored (eg grayscale output from YCbCr image),
172    * we can skip most computations for the unused components.
173    */
174   boolean component_needed;     /* do we need the value of this component? */
175 
176   /* These values are computed before starting a scan of the component. */
177   /* The decompressor output side may not use these variables. */
178   int MCU_width;                /* number of blocks per MCU, horizontally */
179   int MCU_height;               /* number of blocks per MCU, vertically */
180   int MCU_blocks;               /* MCU_width * MCU_height */
181   int MCU_sample_width;         /* MCU width in samples, MCU_width*DCT_[h_]scaled_size */
182   int last_col_width;           /* # of non-dummy blocks across in last MCU */
183   int last_row_height;          /* # of non-dummy blocks down in last MCU */
184 
185   /* Saved quantization table for component; NULL if none yet saved.
186    * See jdinput.c comments about the need for this information.
187    * This field is currently used only for decompression.
188    */
189   JQUANT_TBL *quant_table;
190 
191   /* Private per-component storage for DCT or IDCT subsystem. */
192   void *dct_table;
193 } jpeg_component_info;
194 
195 
196 /* The script for encoding a multiple-scan file is an array of these: */
197 
198 typedef struct {
199   int comps_in_scan;            /* number of components encoded in this scan */
200   int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
201   int Ss, Se;                   /* progressive JPEG spectral selection parms */
202   int Ah, Al;                   /* progressive JPEG successive approx. parms */
203 } jpeg_scan_info;
204 
205 /* The decompressor can save APPn and COM markers in a list of these: */
206 
207 typedef struct jpeg_marker_struct *jpeg_saved_marker_ptr;
208 
209 struct jpeg_marker_struct {
210   jpeg_saved_marker_ptr next;   /* next in list, or NULL */
211   UINT8 marker;                 /* marker code: JPEG_COM, or JPEG_APP0+n */
212   unsigned int original_length; /* # bytes of data in the file */
213   unsigned int data_length;     /* # bytes of data saved at data[] */
214   JOCTET *data;                 /* the data contained in the marker */
215   /* the marker length word is not counted in data_length or original_length */
216 };
217 
218 /* Known color spaces. */
219 
220 #define JCS_EXTENSIONS  1
221 #define JCS_ALPHA_EXTENSIONS  1
222 
223 typedef enum {
224   JCS_UNKNOWN,            /* error/unspecified */
225   JCS_GRAYSCALE,          /* monochrome */
226   JCS_RGB,                /* red/green/blue as specified by the RGB_RED,
227                              RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros */
228   JCS_YCbCr,              /* Y/Cb/Cr (also known as YUV) */
229   JCS_CMYK,               /* C/M/Y/K */
230   JCS_YCCK,               /* Y/Cb/Cr/K */
231   JCS_EXT_RGB,            /* red/green/blue */
232   JCS_EXT_RGBX,           /* red/green/blue/x */
233   JCS_EXT_BGR,            /* blue/green/red */
234   JCS_EXT_BGRX,           /* blue/green/red/x */
235   JCS_EXT_XBGR,           /* x/blue/green/red */
236   JCS_EXT_XRGB,           /* x/red/green/blue */
237   /* When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX, JCS_EXT_XBGR,
238      or JCS_EXT_XRGB during decompression, the X byte is undefined, and in
239      order to ensure the best performance, libjpeg-turbo can set that byte to
240      whatever value it wishes.  Use the following colorspace constants to
241      ensure that the X byte is set to 0xFF, so that it can be interpreted as an
242      opaque alpha channel. */
243   JCS_EXT_RGBA,           /* red/green/blue/alpha */
244   JCS_EXT_BGRA,           /* blue/green/red/alpha */
245   JCS_EXT_ABGR,           /* alpha/blue/green/red */
246   JCS_EXT_ARGB,           /* alpha/red/green/blue */
247   JCS_RGB565              /* 5-bit red/6-bit green/5-bit blue */
248 } J_COLOR_SPACE;
249 
250 /* DCT/IDCT algorithm options. */
251 
252 typedef enum {
253   JDCT_ISLOW,             /* accurate integer method */
254   JDCT_IFAST,             /* less accurate integer method [legacy feature] */
255   JDCT_FLOAT              /* floating-point method [legacy feature] */
256 } J_DCT_METHOD;
257 
258 #ifndef JDCT_DEFAULT            /* may be overridden in jconfig.h */
259 #define JDCT_DEFAULT  JDCT_ISLOW
260 #endif
261 #ifndef JDCT_FASTEST            /* may be overridden in jconfig.h */
262 #define JDCT_FASTEST  JDCT_IFAST
263 #endif
264 
265 /* Dithering options for decompression. */
266 
267 typedef enum {
268   JDITHER_NONE,           /* no dithering */
269   JDITHER_ORDERED,        /* simple ordered dither */
270   JDITHER_FS              /* Floyd-Steinberg error diffusion dither */
271 } J_DITHER_MODE;
272 
273 
274 /* Common fields between JPEG compression and decompression master structs. */
275 
276 #define jpeg_common_fields \
277   struct jpeg_error_mgr *err;   /* Error handler module */ \
278   struct jpeg_memory_mgr *mem;  /* Memory manager module */ \
279   struct jpeg_progress_mgr *progress; /* Progress monitor, or NULL if none */ \
280   void *client_data;            /* Available for use by application */ \
281   boolean is_decompressor;      /* So common code can tell which is which */ \
282   int global_state              /* For checking call sequence validity */
283 
284 /* Routines that are to be used by both halves of the library are declared
285  * to receive a pointer to this structure.  There are no actual instances of
286  * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
287  */
288 struct jpeg_common_struct {
289   jpeg_common_fields;           /* Fields common to both master struct types */
290   /* Additional fields follow in an actual jpeg_compress_struct or
291    * jpeg_decompress_struct.  All three structs must agree on these
292    * initial fields!  (This would be a lot cleaner in C++.)
293    */
294 };
295 
296 typedef struct jpeg_common_struct *j_common_ptr;
297 typedef struct jpeg_compress_struct *j_compress_ptr;
298 typedef struct jpeg_decompress_struct *j_decompress_ptr;
299 
300 
301 /* Master record for a compression instance */
302 
303 struct jpeg_compress_struct {
304   jpeg_common_fields;           /* Fields shared with jpeg_decompress_struct */
305 
306   /* Destination for compressed data */
307   struct jpeg_destination_mgr *dest;
308 
309   /* Description of source image --- these fields must be filled in by
310    * outer application before starting compression.  in_color_space must
311    * be correct before you can even call jpeg_set_defaults().
312    */
313 
314   JDIMENSION image_width;       /* input image width */
315   JDIMENSION image_height;      /* input image height */
316   int input_components;         /* # of color components in input image */
317   J_COLOR_SPACE in_color_space; /* colorspace of input image */
318 
319   double input_gamma;           /* image gamma of input image */
320 
321   /* Compression parameters --- these fields must be set before calling
322    * jpeg_start_compress().  We recommend calling jpeg_set_defaults() to
323    * initialize everything to reasonable defaults, then changing anything
324    * the application specifically wants to change.  That way you won't get
325    * burnt when new parameters are added.  Also note that there are several
326    * helper routines to simplify changing parameters.
327    */
328 
329 #if JPEG_LIB_VERSION >= 70
330   unsigned int scale_num, scale_denom; /* fraction by which to scale image */
331 
332   JDIMENSION jpeg_width;        /* scaled JPEG image width */
333   JDIMENSION jpeg_height;       /* scaled JPEG image height */
334   /* Dimensions of actual JPEG image that will be written to file,
335    * derived from input dimensions by scaling factors above.
336    * These fields are computed by jpeg_start_compress().
337    * You can also use jpeg_calc_jpeg_dimensions() to determine these values
338    * in advance of calling jpeg_start_compress().
339    */
340 #endif
341 
342   int data_precision;           /* bits of precision in image data */
343 
344   int num_components;           /* # of color components in JPEG image */
345   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
346 
347   jpeg_component_info *comp_info;
348   /* comp_info[i] describes component that appears i'th in SOF */
349 
350   JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
351 #if JPEG_LIB_VERSION >= 70
352   int q_scale_factor[NUM_QUANT_TBLS];
353 #endif
354   /* ptrs to coefficient quantization tables, or NULL if not defined,
355    * and corresponding scale factors (percentage, initialized 100).
356    */
357 
358   JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
359   JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
360   /* ptrs to Huffman coding tables, or NULL if not defined */
361 
362   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
363   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
364   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
365 
366   int num_scans;                /* # of entries in scan_info array */
367   const jpeg_scan_info *scan_info; /* script for multi-scan file, or NULL */
368   /* The default value of scan_info is NULL, which causes a single-scan
369    * sequential JPEG file to be emitted.  To create a multi-scan file,
370    * set num_scans and scan_info to point to an array of scan definitions.
371    */
372 
373   boolean raw_data_in;          /* TRUE=caller supplies downsampled data */
374   boolean arith_code;           /* TRUE=arithmetic coding, FALSE=Huffman */
375   boolean optimize_coding;      /* TRUE=optimize entropy encoding parms */
376   boolean CCIR601_sampling;     /* TRUE=first samples are cosited */
377 #if JPEG_LIB_VERSION >= 70
378   boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
379 #endif
380   int smoothing_factor;         /* 1..100, or 0 for no input smoothing */
381   J_DCT_METHOD dct_method;      /* DCT algorithm selector */
382 
383   /* The restart interval can be specified in absolute MCUs by setting
384    * restart_interval, or in MCU rows by setting restart_in_rows
385    * (in which case the correct restart_interval will be figured
386    * for each scan).
387    */
388   unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
389   int restart_in_rows;          /* if > 0, MCU rows per restart interval */
390 
391   /* Parameters controlling emission of special markers. */
392 
393   boolean write_JFIF_header;    /* should a JFIF marker be written? */
394   UINT8 JFIF_major_version;     /* What to write for the JFIF version number */
395   UINT8 JFIF_minor_version;
396   /* These three values are not used by the JPEG code, merely copied */
397   /* into the JFIF APP0 marker.  density_unit can be 0 for unknown, */
398   /* 1 for dots/inch, or 2 for dots/cm.  Note that the pixel aspect */
399   /* ratio is defined by X_density/Y_density even when density_unit=0. */
400   UINT8 density_unit;           /* JFIF code for pixel size units */
401   UINT16 X_density;             /* Horizontal pixel density */
402   UINT16 Y_density;             /* Vertical pixel density */
403   boolean write_Adobe_marker;   /* should an Adobe marker be written? */
404 
405   /* State variable: index of next scanline to be written to
406    * jpeg_write_scanlines().  Application may use this to control its
407    * processing loop, e.g., "while (next_scanline < image_height)".
408    */
409 
410   JDIMENSION next_scanline;     /* 0 .. image_height-1  */
411 
412   /* Remaining fields are known throughout compressor, but generally
413    * should not be touched by a surrounding application.
414    */
415 
416   /*
417    * These fields are computed during compression startup
418    */
419   boolean progressive_mode;     /* TRUE if scan script uses progressive mode */
420   int max_h_samp_factor;        /* largest h_samp_factor */
421   int max_v_samp_factor;        /* largest v_samp_factor */
422 
423 #if JPEG_LIB_VERSION >= 70
424   int min_DCT_h_scaled_size;    /* smallest DCT_h_scaled_size of any component */
425   int min_DCT_v_scaled_size;    /* smallest DCT_v_scaled_size of any component */
426 #endif
427 
428   JDIMENSION total_iMCU_rows;   /* # of iMCU rows to be input to coef ctlr */
429   /* The coefficient controller receives data in units of MCU rows as defined
430    * for fully interleaved scans (whether the JPEG file is interleaved or not).
431    * There are v_samp_factor * DCTSIZE sample rows of each component in an
432    * "iMCU" (interleaved MCU) row.
433    */
434 
435   /*
436    * These fields are valid during any one scan.
437    * They describe the components and MCUs actually appearing in the scan.
438    */
439   int comps_in_scan;            /* # of JPEG components in this scan */
440   jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
441   /* *cur_comp_info[i] describes component that appears i'th in SOS */
442 
443   JDIMENSION MCUs_per_row;      /* # of MCUs across the image */
444   JDIMENSION MCU_rows_in_scan;  /* # of MCU rows in the image */
445 
446   int blocks_in_MCU;            /* # of DCT blocks per MCU */
447   int MCU_membership[C_MAX_BLOCKS_IN_MCU];
448   /* MCU_membership[i] is index in cur_comp_info of component owning */
449   /* i'th block in an MCU */
450 
451   int Ss, Se, Ah, Al;           /* progressive JPEG parameters for scan */
452 
453 #if JPEG_LIB_VERSION >= 80
454   int block_size;               /* the basic DCT block size: 1..16 */
455   const int *natural_order;     /* natural-order position array */
456   int lim_Se;                   /* min( Se, DCTSIZE2-1 ) */
457 #endif
458 
459   /*
460    * Links to compression subobjects (methods and private variables of modules)
461    */
462   struct jpeg_comp_master *master;
463   struct jpeg_c_main_controller *main;
464   struct jpeg_c_prep_controller *prep;
465   struct jpeg_c_coef_controller *coef;
466   struct jpeg_marker_writer *marker;
467   struct jpeg_color_converter *cconvert;
468   struct jpeg_downsampler *downsample;
469   struct jpeg_forward_dct *fdct;
470   struct jpeg_entropy_encoder *entropy;
471   jpeg_scan_info *script_space; /* workspace for jpeg_simple_progression */
472   int script_space_size;
473 };
474 
475 
476 /* Master record for a decompression instance */
477 
478 struct jpeg_decompress_struct {
479   jpeg_common_fields;           /* Fields shared with jpeg_compress_struct */
480 
481   /* Source of compressed data */
482   struct jpeg_source_mgr *src;
483 
484   /* Basic description of image --- filled in by jpeg_read_header(). */
485   /* Application may inspect these values to decide how to process image. */
486 
487   JDIMENSION image_width;       /* nominal image width (from SOF marker) */
488   JDIMENSION image_height;      /* nominal image height */
489   int num_components;           /* # of color components in JPEG image */
490   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
491 
492   /* Decompression processing parameters --- these fields must be set before
493    * calling jpeg_start_decompress().  Note that jpeg_read_header() initializes
494    * them to default values.
495    */
496 
497   J_COLOR_SPACE out_color_space; /* colorspace for output */
498 
499   unsigned int scale_num, scale_denom; /* fraction by which to scale image */
500 
501   double output_gamma;          /* image gamma wanted in output */
502 
503   boolean buffered_image;       /* TRUE=multiple output passes */
504   boolean raw_data_out;         /* TRUE=downsampled data wanted */
505 
506   J_DCT_METHOD dct_method;      /* IDCT algorithm selector */
507   boolean do_fancy_upsampling;  /* TRUE=apply fancy upsampling */
508   boolean do_block_smoothing;   /* TRUE=apply interblock smoothing */
509 
510   boolean quantize_colors;      /* TRUE=colormapped output wanted */
511   /* the following are ignored if not quantize_colors: */
512   J_DITHER_MODE dither_mode;    /* type of color dithering to use */
513   boolean two_pass_quantize;    /* TRUE=use two-pass color quantization */
514   int desired_number_of_colors; /* max # colors to use in created colormap */
515   /* these are significant only in buffered-image mode: */
516   boolean enable_1pass_quant;   /* enable future use of 1-pass quantizer */
517   boolean enable_external_quant;/* enable future use of external colormap */
518   boolean enable_2pass_quant;   /* enable future use of 2-pass quantizer */
519 
520   /* Description of actual output image that will be returned to application.
521    * These fields are computed by jpeg_start_decompress().
522    * You can also use jpeg_calc_output_dimensions() to determine these values
523    * in advance of calling jpeg_start_decompress().
524    */
525 
526   JDIMENSION output_width;      /* scaled image width */
527   JDIMENSION output_height;     /* scaled image height */
528   int out_color_components;     /* # of color components in out_color_space */
529   int output_components;        /* # of color components returned */
530   /* output_components is 1 (a colormap index) when quantizing colors;
531    * otherwise it equals out_color_components.
532    */
533   int rec_outbuf_height;        /* min recommended height of scanline buffer */
534   /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
535    * high, space and time will be wasted due to unnecessary data copying.
536    * Usually rec_outbuf_height will be 1 or 2, at most 4.
537    */
538 
539   /* When quantizing colors, the output colormap is described by these fields.
540    * The application can supply a colormap by setting colormap non-NULL before
541    * calling jpeg_start_decompress; otherwise a colormap is created during
542    * jpeg_start_decompress or jpeg_start_output.
543    * The map has out_color_components rows and actual_number_of_colors columns.
544    */
545   int actual_number_of_colors;  /* number of entries in use */
546   JSAMPARRAY colormap;          /* The color map as a 2-D pixel array */
547 
548   /* State variables: these variables indicate the progress of decompression.
549    * The application may examine these but must not modify them.
550    */
551 
552   /* Row index of next scanline to be read from jpeg_read_scanlines().
553    * Application may use this to control its processing loop, e.g.,
554    * "while (output_scanline < output_height)".
555    */
556   JDIMENSION output_scanline;   /* 0 .. output_height-1  */
557 
558   /* Current input scan number and number of iMCU rows completed in scan.
559    * These indicate the progress of the decompressor input side.
560    */
561   int input_scan_number;        /* Number of SOS markers seen so far */
562   JDIMENSION input_iMCU_row;    /* Number of iMCU rows completed */
563 
564   /* The "output scan number" is the notional scan being displayed by the
565    * output side.  The decompressor will not allow output scan/row number
566    * to get ahead of input scan/row, but it can fall arbitrarily far behind.
567    */
568   int output_scan_number;       /* Nominal scan number being displayed */
569   JDIMENSION output_iMCU_row;   /* Number of iMCU rows read */
570 
571   /* Current progression status.  coef_bits[c][i] indicates the precision
572    * with which component c's DCT coefficient i (in zigzag order) is known.
573    * It is -1 when no data has yet been received, otherwise it is the point
574    * transform (shift) value for the most recent scan of the coefficient
575    * (thus, 0 at completion of the progression).
576    * This pointer is NULL when reading a non-progressive file.
577    */
578   int (*coef_bits)[DCTSIZE2];   /* -1 or current Al value for each coef */
579 
580   /* Internal JPEG parameters --- the application usually need not look at
581    * these fields.  Note that the decompressor output side may not use
582    * any parameters that can change between scans.
583    */
584 
585   /* Quantization and Huffman tables are carried forward across input
586    * datastreams when processing abbreviated JPEG datastreams.
587    */
588 
589   JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
590   /* ptrs to coefficient quantization tables, or NULL if not defined */
591 
592   JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
593   JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
594   /* ptrs to Huffman coding tables, or NULL if not defined */
595 
596   /* These parameters are never carried across datastreams, since they
597    * are given in SOF/SOS markers or defined to be reset by SOI.
598    */
599 
600   int data_precision;           /* bits of precision in image data */
601 
602   jpeg_component_info *comp_info;
603   /* comp_info[i] describes component that appears i'th in SOF */
604 
605 #if JPEG_LIB_VERSION >= 80
606   boolean is_baseline;          /* TRUE if Baseline SOF0 encountered */
607 #endif
608   boolean progressive_mode;     /* TRUE if SOFn specifies progressive mode */
609   boolean arith_code;           /* TRUE=arithmetic coding, FALSE=Huffman */
610 
611   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
612   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
613   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
614 
615   unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
616 
617   /* These fields record data obtained from optional markers recognized by
618    * the JPEG library.
619    */
620   boolean saw_JFIF_marker;      /* TRUE iff a JFIF APP0 marker was found */
621   /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
622   UINT8 JFIF_major_version;     /* JFIF version number */
623   UINT8 JFIF_minor_version;
624   UINT8 density_unit;           /* JFIF code for pixel size units */
625   UINT16 X_density;             /* Horizontal pixel density */
626   UINT16 Y_density;             /* Vertical pixel density */
627   boolean saw_Adobe_marker;     /* TRUE iff an Adobe APP14 marker was found */
628   UINT8 Adobe_transform;        /* Color transform code from Adobe marker */
629 
630   boolean CCIR601_sampling;     /* TRUE=first samples are cosited */
631 
632   /* Aside from the specific data retained from APPn markers known to the
633    * library, the uninterpreted contents of any or all APPn and COM markers
634    * can be saved in a list for examination by the application.
635    */
636   jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
637 
638   /* Remaining fields are known throughout decompressor, but generally
639    * should not be touched by a surrounding application.
640    */
641 
642   /*
643    * These fields are computed during decompression startup
644    */
645   int max_h_samp_factor;        /* largest h_samp_factor */
646   int max_v_samp_factor;        /* largest v_samp_factor */
647 
648 #if JPEG_LIB_VERSION >= 70
649   int min_DCT_h_scaled_size;    /* smallest DCT_h_scaled_size of any component */
650   int min_DCT_v_scaled_size;    /* smallest DCT_v_scaled_size of any component */
651 #else
652   int min_DCT_scaled_size;      /* smallest DCT_scaled_size of any component */
653 #endif
654 
655   JDIMENSION total_iMCU_rows;   /* # of iMCU rows in image */
656   /* The coefficient controller's input and output progress is measured in
657    * units of "iMCU" (interleaved MCU) rows.  These are the same as MCU rows
658    * in fully interleaved JPEG scans, but are used whether the scan is
659    * interleaved or not.  We define an iMCU row as v_samp_factor DCT block
660    * rows of each component.  Therefore, the IDCT output contains
661    * v_samp_factor*DCT_[v_]scaled_size sample rows of a component per iMCU row.
662    */
663 
664   JSAMPLE *sample_range_limit;  /* table for fast range-limiting */
665 
666   /*
667    * These fields are valid during any one scan.
668    * They describe the components and MCUs actually appearing in the scan.
669    * Note that the decompressor output side must not use these fields.
670    */
671   int comps_in_scan;            /* # of JPEG components in this scan */
672   jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
673   /* *cur_comp_info[i] describes component that appears i'th in SOS */
674 
675   JDIMENSION MCUs_per_row;      /* # of MCUs across the image */
676   JDIMENSION MCU_rows_in_scan;  /* # of MCU rows in the image */
677 
678   int blocks_in_MCU;            /* # of DCT blocks per MCU */
679   int MCU_membership[D_MAX_BLOCKS_IN_MCU];
680   /* MCU_membership[i] is index in cur_comp_info of component owning */
681   /* i'th block in an MCU */
682 
683   int Ss, Se, Ah, Al;           /* progressive JPEG parameters for scan */
684 
685 #if JPEG_LIB_VERSION >= 80
686   /* These fields are derived from Se of first SOS marker.
687    */
688   int block_size;               /* the basic DCT block size: 1..16 */
689   const int *natural_order; /* natural-order position array for entropy decode */
690   int lim_Se;                   /* min( Se, DCTSIZE2-1 ) for entropy decode */
691 #endif
692 
693   /* This field is shared between entropy decoder and marker parser.
694    * It is either zero or the code of a JPEG marker that has been
695    * read from the data source, but has not yet been processed.
696    */
697   int unread_marker;
698 
699   /*
700    * Links to decompression subobjects (methods, private variables of modules)
701    */
702   struct jpeg_decomp_master *master;
703   struct jpeg_d_main_controller *main;
704   struct jpeg_d_coef_controller *coef;
705   struct jpeg_d_post_controller *post;
706   struct jpeg_input_controller *inputctl;
707   struct jpeg_marker_reader *marker;
708   struct jpeg_entropy_decoder *entropy;
709   struct jpeg_inverse_dct *idct;
710   struct jpeg_upsampler *upsample;
711   struct jpeg_color_deconverter *cconvert;
712   struct jpeg_color_quantizer *cquantize;
713 };
714 
715 
716 /* "Object" declarations for JPEG modules that may be supplied or called
717  * directly by the surrounding application.
718  * As with all objects in the JPEG library, these structs only define the
719  * publicly visible methods and state variables of a module.  Additional
720  * private fields may exist after the public ones.
721  */
722 
723 
724 /* Error handler object */
725 
726 struct jpeg_error_mgr {
727   /* Error exit handler: does not return to caller */
728   void (*error_exit) (j_common_ptr cinfo);
729   /* Conditionally emit a trace or warning message */
730   void (*emit_message) (j_common_ptr cinfo, int msg_level);
731   /* Routine that actually outputs a trace or error message */
732   void (*output_message) (j_common_ptr cinfo);
733   /* Format a message string for the most recent JPEG error or message */
734   void (*format_message) (j_common_ptr cinfo, char *buffer);
735 #define JMSG_LENGTH_MAX  200    /* recommended size of format_message buffer */
736   /* Reset error state variables at start of a new image */
737   void (*reset_error_mgr) (j_common_ptr cinfo);
738 
739   /* The message ID code and any parameters are saved here.
740    * A message can have one string parameter or up to 8 int parameters.
741    */
742   int msg_code;
743 #define JMSG_STR_PARM_MAX  80
744   union {
745     int i[8];
746     char s[JMSG_STR_PARM_MAX];
747   } msg_parm;
748 
749   /* Standard state variables for error facility */
750 
751   int trace_level;              /* max msg_level that will be displayed */
752 
753   /* For recoverable corrupt-data errors, we emit a warning message,
754    * but keep going unless emit_message chooses to abort.  emit_message
755    * should count warnings in num_warnings.  The surrounding application
756    * can check for bad data by seeing if num_warnings is nonzero at the
757    * end of processing.
758    */
759   long num_warnings;            /* number of corrupt-data warnings */
760 
761   /* These fields point to the table(s) of error message strings.
762    * An application can change the table pointer to switch to a different
763    * message list (typically, to change the language in which errors are
764    * reported).  Some applications may wish to add additional error codes
765    * that will be handled by the JPEG library error mechanism; the second
766    * table pointer is used for this purpose.
767    *
768    * First table includes all errors generated by JPEG library itself.
769    * Error code 0 is reserved for a "no such error string" message.
770    */
771   const char * const *jpeg_message_table; /* Library errors */
772   int last_jpeg_message;    /* Table contains strings 0..last_jpeg_message */
773   /* Second table can be added by application (see cjpeg/djpeg for example).
774    * It contains strings numbered first_addon_message..last_addon_message.
775    */
776   const char * const *addon_message_table; /* Non-library errors */
777   int first_addon_message;      /* code for first string in addon table */
778   int last_addon_message;       /* code for last string in addon table */
779 };
780 
781 
782 /* Progress monitor object */
783 
784 struct jpeg_progress_mgr {
785   void (*progress_monitor) (j_common_ptr cinfo);
786 
787   long pass_counter;            /* work units completed in this pass */
788   long pass_limit;              /* total number of work units in this pass */
789   int completed_passes;         /* passes completed so far */
790   int total_passes;             /* total number of passes expected */
791 };
792 
793 
794 /* Data destination object for compression */
795 
796 struct jpeg_destination_mgr {
797   JOCTET *next_output_byte;     /* => next byte to write in buffer */
798   size_t free_in_buffer;        /* # of byte spaces remaining in buffer */
799 
800   void (*init_destination) (j_compress_ptr cinfo);
801   boolean (*empty_output_buffer) (j_compress_ptr cinfo);
802   void (*term_destination) (j_compress_ptr cinfo);
803 };
804 
805 
806 /* Data source object for decompression */
807 
808 struct jpeg_source_mgr {
809   const JOCTET *next_input_byte; /* => next byte to read from buffer */
810   size_t bytes_in_buffer;       /* # of bytes remaining in buffer */
811 
812   void (*init_source) (j_decompress_ptr cinfo);
813   boolean (*fill_input_buffer) (j_decompress_ptr cinfo);
814   void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes);
815   boolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired);
816   void (*term_source) (j_decompress_ptr cinfo);
817 };
818 
819 
820 /* Memory manager object.
821  * Allocates "small" objects (a few K total), "large" objects (tens of K),
822  * and "really big" objects (virtual arrays with backing store if needed).
823  * The memory manager does not allow individual objects to be freed; rather,
824  * each created object is assigned to a pool, and whole pools can be freed
825  * at once.  This is faster and more convenient than remembering exactly what
826  * to free, especially where malloc()/free() are not too speedy.
827  * NB: alloc routines never return NULL.  They exit to error_exit if not
828  * successful.
829  */
830 
831 #define JPOOL_PERMANENT  0      /* lasts until master record is destroyed */
832 #define JPOOL_IMAGE      1      /* lasts until done with image/datastream */
833 #define JPOOL_NUMPOOLS   2
834 
835 typedef struct jvirt_sarray_control *jvirt_sarray_ptr;
836 typedef struct jvirt_barray_control *jvirt_barray_ptr;
837 
838 
839 struct jpeg_memory_mgr {
840   /* Method pointers */
841   void *(*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject);
842   void *(*alloc_large) (j_common_ptr cinfo, int pool_id,
843                         size_t sizeofobject);
844   JSAMPARRAY (*alloc_sarray) (j_common_ptr cinfo, int pool_id,
845                               JDIMENSION samplesperrow, JDIMENSION numrows);
846   JBLOCKARRAY (*alloc_barray) (j_common_ptr cinfo, int pool_id,
847                                JDIMENSION blocksperrow, JDIMENSION numrows);
848   jvirt_sarray_ptr (*request_virt_sarray) (j_common_ptr cinfo, int pool_id,
849                                            boolean pre_zero,
850                                            JDIMENSION samplesperrow,
851                                            JDIMENSION numrows,
852                                            JDIMENSION maxaccess);
853   jvirt_barray_ptr (*request_virt_barray) (j_common_ptr cinfo, int pool_id,
854                                            boolean pre_zero,
855                                            JDIMENSION blocksperrow,
856                                            JDIMENSION numrows,
857                                            JDIMENSION maxaccess);
858   void (*realize_virt_arrays) (j_common_ptr cinfo);
859   JSAMPARRAY (*access_virt_sarray) (j_common_ptr cinfo, jvirt_sarray_ptr ptr,
860                                     JDIMENSION start_row, JDIMENSION num_rows,
861                                     boolean writable);
862   JBLOCKARRAY (*access_virt_barray) (j_common_ptr cinfo, jvirt_barray_ptr ptr,
863                                      JDIMENSION start_row, JDIMENSION num_rows,
864                                      boolean writable);
865   void (*free_pool) (j_common_ptr cinfo, int pool_id);
866   void (*self_destruct) (j_common_ptr cinfo);
867 
868   /* Limit on memory allocation for this JPEG object.  (Note that this is
869    * merely advisory, not a guaranteed maximum; it only affects the space
870    * used for virtual-array buffers.)  May be changed by outer application
871    * after creating the JPEG object.
872    */
873   long max_memory_to_use;
874 
875   /* Maximum allocation request accepted by alloc_large. */
876   long max_alloc_chunk;
877 };
878 
879 
880 /* Routine signature for application-supplied marker processing methods.
881  * Need not pass marker code since it is stored in cinfo->unread_marker.
882  */
883 typedef boolean (*jpeg_marker_parser_method) (j_decompress_ptr cinfo);
884 
885 
886 /* Originally, this macro was used as a way of defining function prototypes
887  * for both modern compilers as well as older compilers that did not support
888  * prototype parameters.  libjpeg-turbo has never supported these older,
889  * non-ANSI compilers, but the macro is still included because there is some
890  * software out there that uses it.
891  */
892 
893 #define JPP(arglist)    arglist
894 
895 
896 /* Default error-management setup */
897 EXTERN(struct jpeg_error_mgr *) jpeg_std_error(struct jpeg_error_mgr *err);
898 
899 /* Initialization of JPEG compression objects.
900  * jpeg_create_compress() and jpeg_create_decompress() are the exported
901  * names that applications should call.  These expand to calls on
902  * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
903  * passed for version mismatch checking.
904  * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
905  */
906 #define jpeg_create_compress(cinfo) \
907   jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
908                       (size_t)sizeof(struct jpeg_compress_struct))
909 #define jpeg_create_decompress(cinfo) \
910   jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
911                         (size_t)sizeof(struct jpeg_decompress_struct))
912 EXTERN(void) jpeg_CreateCompress(j_compress_ptr cinfo, int version,
913                                  size_t structsize);
914 EXTERN(void) jpeg_CreateDecompress(j_decompress_ptr cinfo, int version,
915                                    size_t structsize);
916 /* Destruction of JPEG compression objects */
917 EXTERN(void) jpeg_destroy_compress(j_compress_ptr cinfo);
918 EXTERN(void) jpeg_destroy_decompress(j_decompress_ptr cinfo);
919 
920 /* Standard data source and destination managers: stdio streams. */
921 /* Caller is responsible for opening the file before and closing after. */
922 EXTERN(void) jpeg_stdio_dest(j_compress_ptr cinfo, FILE *outfile);
923 EXTERN(void) jpeg_stdio_src(j_decompress_ptr cinfo, FILE *infile);
924 
925 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
926 /* Data source and destination managers: memory buffers. */
927 EXTERN(void) jpeg_mem_dest(j_compress_ptr cinfo, unsigned char **outbuffer,
928                            unsigned long *outsize);
929 EXTERN(void) jpeg_mem_src(j_decompress_ptr cinfo,
930                           const unsigned char *inbuffer, unsigned long insize);
931 #endif
932 
933 /* Default parameter setup for compression */
934 EXTERN(void) jpeg_set_defaults(j_compress_ptr cinfo);
935 /* Compression parameter setup aids */
936 EXTERN(void) jpeg_set_colorspace(j_compress_ptr cinfo,
937                                  J_COLOR_SPACE colorspace);
938 EXTERN(void) jpeg_default_colorspace(j_compress_ptr cinfo);
939 EXTERN(void) jpeg_set_quality(j_compress_ptr cinfo, int quality,
940                               boolean force_baseline);
941 EXTERN(void) jpeg_set_linear_quality(j_compress_ptr cinfo, int scale_factor,
942                                      boolean force_baseline);
943 #if JPEG_LIB_VERSION >= 70
944 EXTERN(void) jpeg_default_qtables(j_compress_ptr cinfo,
945                                   boolean force_baseline);
946 #endif
947 EXTERN(void) jpeg_add_quant_table(j_compress_ptr cinfo, int which_tbl,
948                                   const unsigned int *basic_table,
949                                   int scale_factor, boolean force_baseline);
950 EXTERN(int) jpeg_quality_scaling(int quality);
951 EXTERN(void) jpeg_simple_progression(j_compress_ptr cinfo);
952 EXTERN(void) jpeg_suppress_tables(j_compress_ptr cinfo, boolean suppress);
953 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table(j_common_ptr cinfo);
954 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table(j_common_ptr cinfo);
955 
956 /* Main entry points for compression */
957 EXTERN(void) jpeg_start_compress(j_compress_ptr cinfo,
958                                  boolean write_all_tables);
959 EXTERN(JDIMENSION) jpeg_write_scanlines(j_compress_ptr cinfo,
960                                         JSAMPARRAY scanlines,
961                                         JDIMENSION num_lines);
962 EXTERN(void) jpeg_finish_compress(j_compress_ptr cinfo);
963 
964 #if JPEG_LIB_VERSION >= 70
965 /* Precalculate JPEG dimensions for current compression parameters. */
966 EXTERN(void) jpeg_calc_jpeg_dimensions(j_compress_ptr cinfo);
967 #endif
968 
969 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
970 EXTERN(JDIMENSION) jpeg_write_raw_data(j_compress_ptr cinfo, JSAMPIMAGE data,
971                                        JDIMENSION num_lines);
972 
973 /* Write a special marker.  See libjpeg.txt concerning safe usage. */
974 EXTERN(void) jpeg_write_marker(j_compress_ptr cinfo, int marker,
975                                const JOCTET *dataptr, unsigned int datalen);
976 /* Same, but piecemeal. */
977 EXTERN(void) jpeg_write_m_header(j_compress_ptr cinfo, int marker,
978                                  unsigned int datalen);
979 EXTERN(void) jpeg_write_m_byte(j_compress_ptr cinfo, int val);
980 
981 /* Alternate compression function: just write an abbreviated table file */
982 EXTERN(void) jpeg_write_tables(j_compress_ptr cinfo);
983 
984 /* Write ICC profile.  See libjpeg.txt for usage information. */
985 EXTERN(void) jpeg_write_icc_profile(j_compress_ptr cinfo,
986                                     const JOCTET *icc_data_ptr,
987                                     unsigned int icc_data_len);
988 
989 
990 /* Decompression startup: read start of JPEG datastream to see what's there */
991 EXTERN(int) jpeg_read_header(j_decompress_ptr cinfo, boolean require_image);
992 /* Return value is one of: */
993 #define JPEG_SUSPENDED           0 /* Suspended due to lack of input data */
994 #define JPEG_HEADER_OK           1 /* Found valid image datastream */
995 #define JPEG_HEADER_TABLES_ONLY  2 /* Found valid table-specs-only datastream */
996 /* If you pass require_image = TRUE (normal case), you need not check for
997  * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
998  * JPEG_SUSPENDED is only possible if you use a data source module that can
999  * give a suspension return (the stdio source module doesn't).
1000  */
1001 
1002 /* Main entry points for decompression */
1003 EXTERN(boolean) jpeg_start_decompress(j_decompress_ptr cinfo);
1004 EXTERN(JDIMENSION) jpeg_read_scanlines(j_decompress_ptr cinfo,
1005                                        JSAMPARRAY scanlines,
1006                                        JDIMENSION max_lines);
1007 EXTERN(JDIMENSION) jpeg_skip_scanlines(j_decompress_ptr cinfo,
1008                                        JDIMENSION num_lines);
1009 EXTERN(void) jpeg_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
1010                                 JDIMENSION *width);
1011 EXTERN(boolean) jpeg_finish_decompress(j_decompress_ptr cinfo);
1012 
1013 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
1014 EXTERN(JDIMENSION) jpeg_read_raw_data(j_decompress_ptr cinfo, JSAMPIMAGE data,
1015                                       JDIMENSION max_lines);
1016 
1017 /* Additional entry points for buffered-image mode. */
1018 EXTERN(boolean) jpeg_has_multiple_scans(j_decompress_ptr cinfo);
1019 EXTERN(boolean) jpeg_start_output(j_decompress_ptr cinfo, int scan_number);
1020 EXTERN(boolean) jpeg_finish_output(j_decompress_ptr cinfo);
1021 EXTERN(boolean) jpeg_input_complete(j_decompress_ptr cinfo);
1022 EXTERN(void) jpeg_new_colormap(j_decompress_ptr cinfo);
1023 EXTERN(int) jpeg_consume_input(j_decompress_ptr cinfo);
1024 /* Return value is one of: */
1025 /* #define JPEG_SUSPENDED       0    Suspended due to lack of input data */
1026 #define JPEG_REACHED_SOS        1 /* Reached start of new scan */
1027 #define JPEG_REACHED_EOI        2 /* Reached end of image */
1028 #define JPEG_ROW_COMPLETED      3 /* Completed one iMCU row */
1029 #define JPEG_SCAN_COMPLETED     4 /* Completed last iMCU row of a scan */
1030 
1031 /* Precalculate output dimensions for current decompression parameters. */
1032 #if JPEG_LIB_VERSION >= 80
1033 EXTERN(void) jpeg_core_output_dimensions(j_decompress_ptr cinfo);
1034 #endif
1035 EXTERN(void) jpeg_calc_output_dimensions(j_decompress_ptr cinfo);
1036 
1037 /* Control saving of COM and APPn markers into marker_list. */
1038 EXTERN(void) jpeg_save_markers(j_decompress_ptr cinfo, int marker_code,
1039                                unsigned int length_limit);
1040 
1041 /* Install a special processing method for COM or APPn markers. */
1042 EXTERN(void) jpeg_set_marker_processor(j_decompress_ptr cinfo,
1043                                        int marker_code,
1044                                        jpeg_marker_parser_method routine);
1045 
1046 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
1047 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients(j_decompress_ptr cinfo);
1048 EXTERN(void) jpeg_write_coefficients(j_compress_ptr cinfo,
1049                                      jvirt_barray_ptr *coef_arrays);
1050 EXTERN(void) jpeg_copy_critical_parameters(j_decompress_ptr srcinfo,
1051                                            j_compress_ptr dstinfo);
1052 
1053 /* If you choose to abort compression or decompression before completing
1054  * jpeg_finish_(de)compress, then you need to clean up to release memory,
1055  * temporary files, etc.  You can just call jpeg_destroy_(de)compress
1056  * if you're done with the JPEG object, but if you want to clean it up and
1057  * reuse it, call this:
1058  */
1059 EXTERN(void) jpeg_abort_compress(j_compress_ptr cinfo);
1060 EXTERN(void) jpeg_abort_decompress(j_decompress_ptr cinfo);
1061 
1062 /* Generic versions of jpeg_abort and jpeg_destroy that work on either
1063  * flavor of JPEG object.  These may be more convenient in some places.
1064  */
1065 EXTERN(void) jpeg_abort(j_common_ptr cinfo);
1066 EXTERN(void) jpeg_destroy(j_common_ptr cinfo);
1067 
1068 /* Default restart-marker-resync procedure for use by data source modules */
1069 EXTERN(boolean) jpeg_resync_to_restart(j_decompress_ptr cinfo, int desired);
1070 
1071 /* Read ICC profile.  See libjpeg.txt for usage information. */
1072 EXTERN(boolean) jpeg_read_icc_profile(j_decompress_ptr cinfo,
1073                                       JOCTET **icc_data_ptr,
1074                                       unsigned int *icc_data_len);
1075 
1076 
1077 /* These marker codes are exported since applications and data source modules
1078  * are likely to want to use them.
1079  */
1080 
1081 #define JPEG_RST0       0xD0    /* RST0 marker code */
1082 #define JPEG_EOI        0xD9    /* EOI marker code */
1083 #define JPEG_APP0       0xE0    /* APP0 marker code */
1084 #define JPEG_COM        0xFE    /* COM marker code */
1085 
1086 
1087 /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1088  * for structure definitions that are never filled in, keep it quiet by
1089  * supplying dummy definitions for the various substructures.
1090  */
1091 
1092 #ifdef INCOMPLETE_TYPES_BROKEN
1093 #ifndef JPEG_INTERNALS          /* will be defined in jpegint.h */
1094 struct jvirt_sarray_control { long dummy; };
1095 struct jvirt_barray_control { long dummy; };
1096 struct jpeg_comp_master { long dummy; };
1097 struct jpeg_c_main_controller { long dummy; };
1098 struct jpeg_c_prep_controller { long dummy; };
1099 struct jpeg_c_coef_controller { long dummy; };
1100 struct jpeg_marker_writer { long dummy; };
1101 struct jpeg_color_converter { long dummy; };
1102 struct jpeg_downsampler { long dummy; };
1103 struct jpeg_forward_dct { long dummy; };
1104 struct jpeg_entropy_encoder { long dummy; };
1105 struct jpeg_decomp_master { long dummy; };
1106 struct jpeg_d_main_controller { long dummy; };
1107 struct jpeg_d_coef_controller { long dummy; };
1108 struct jpeg_d_post_controller { long dummy; };
1109 struct jpeg_input_controller { long dummy; };
1110 struct jpeg_marker_reader { long dummy; };
1111 struct jpeg_entropy_decoder { long dummy; };
1112 struct jpeg_inverse_dct { long dummy; };
1113 struct jpeg_upsampler { long dummy; };
1114 struct jpeg_color_deconverter { long dummy; };
1115 struct jpeg_color_quantizer { long dummy; };
1116 #endif /* JPEG_INTERNALS */
1117 #endif /* INCOMPLETE_TYPES_BROKEN */
1118 
1119 
1120 /*
1121  * The JPEG library modules define JPEG_INTERNALS before including this file.
1122  * The internal structure declarations are read only when that is true.
1123  * Applications using the library should not include jpegint.h, but may wish
1124  * to include jerror.h.
1125  */
1126 
1127 #ifdef JPEG_INTERNALS
1128 #include "jpegint.h"            /* fetch private declarations */
1129 #include "jerror.h"             /* fetch error codes too */
1130 #endif
1131 
1132 #ifdef __cplusplus
1133 #ifndef DONT_USE_EXTERN_C
1134 }
1135 #endif
1136 #endif
1137 
1138 #endif /* JPEGLIB_H */
1139