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