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 * Lossless JPEG Modifications:
8 * Copyright (C) 1999, Ken Murchison.
9 * libjpeg-turbo Modifications:
10 * Copyright (C) 2009-2011, 2013-2014, 2016-2017, 2020, 2022-2023,
12 * Copyright (C) 2015, Google, Inc.
13 * For conditions of distribution and use, see the accompanying README.ijg
16 * This file defines the application interface for the JPEG library.
17 * Most applications using the library need only include this file,
18 * and perhaps jerror.h if they want to know the exact error codes.
25 * First we include the configuration files that record how this
26 * installation of the JPEG library is set up. jconfig.h can be
27 * generated automatically for many systems. jmorecfg.h contains
28 * manual configuration options that most people need not worry about.
31 #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */
32 #include "jconfig.h" /* widely used configuration options */
34 #include "jmorecfg.h" /* seldom changed options */
38 #ifndef DONT_USE_EXTERN_C
43 /* Various constants determining the sizes of things.
44 * All of these are specified by the JPEG standard, so don't change them
45 * if you want to be compatible.
48 /* NOTE: In lossless mode, an MCU contains one or more samples rather than one
49 * or more 8x8 DCT blocks, so the term "data unit" is used to generically
50 * describe a sample in lossless mode or an 8x8 DCT block in lossy mode. To
51 * preserve backward API/ABI compatibility, the field and macro names retain
52 * the "block" terminology.
55 #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */
56 #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
57 #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
58 #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
59 #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
60 #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
61 #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
62 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
63 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
64 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
65 * to handle it. We even let you do this from the jconfig.h file. However,
66 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
67 * sometimes emits noncompliant files doesn't mean you should too.
69 #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on data units/MCU */
70 #ifndef D_MAX_BLOCKS_IN_MCU
71 #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on data units/MCU */
75 /* Data structures for images (arrays of samples and of DCT coefficients).
78 typedef JSAMPLE *JSAMPROW; /* ptr to one image row of pixel samples. */
79 typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */
80 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
82 typedef J12SAMPLE *J12SAMPROW; /* ptr to one image row of 12-bit pixel
84 typedef J12SAMPROW *J12SAMPARRAY; /* ptr to some 12-bit sample rows (a 2-D
85 12-bit sample array) */
86 typedef J12SAMPARRAY *J12SAMPIMAGE; /* a 3-D 12-bit sample array: top index is
89 typedef J16SAMPLE *J16SAMPROW; /* ptr to one image row of 16-bit pixel
91 typedef J16SAMPROW *J16SAMPARRAY; /* ptr to some 16-bit sample rows (a 2-D
92 16-bit sample array) */
93 typedef J16SAMPARRAY *J16SAMPIMAGE; /* a 3-D 16-bit sample array: top index is
96 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
97 typedef JBLOCK *JBLOCKROW; /* pointer to one row of coefficient blocks */
98 typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
99 typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
101 typedef JCOEF *JCOEFPTR; /* useful in a couple of places */
104 /* Types for JPEG compression parameters and working tables. */
107 /* DCT coefficient quantization tables. */
110 /* This array gives the coefficient quantizers in natural array order
111 * (not the zigzag order in which they are stored in a JPEG DQT marker).
112 * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
114 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */
115 /* This field is used only during compression. It's initialized FALSE when
116 * the table is created, and set TRUE when it's been output to the file.
117 * You could suppress output of a table by setting this to TRUE.
118 * (See jpeg_suppress_tables for an example.)
120 boolean sent_table; /* TRUE when table has been output */
124 /* Huffman coding tables. */
127 /* These two fields directly represent the contents of a JPEG DHT marker */
128 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */
129 /* length k bits; bits[0] is unused */
130 UINT8 huffval[256]; /* The symbols, in order of incr code length */
131 /* This field is used only during compression. It's initialized FALSE when
132 * the table is created, and set TRUE when it's been output to the file.
133 * You could suppress output of a table by setting this to TRUE.
134 * (See jpeg_suppress_tables for an example.)
136 boolean sent_table; /* TRUE when table has been output */
140 /* Basic info about one component (color channel). */
143 /* These values are fixed over the whole image. */
144 /* For compression, they must be supplied by parameter setup; */
145 /* for decompression, they are read from the SOF marker. */
146 int component_id; /* identifier for this component (0..255) */
147 int component_index; /* its index in SOF or cinfo->comp_info[] */
148 int h_samp_factor; /* horizontal sampling factor (1..4) */
149 int v_samp_factor; /* vertical sampling factor (1..4) */
150 int quant_tbl_no; /* quantization table selector (0..3) */
151 /* These values may vary between scans. */
152 /* For compression, they must be supplied by parameter setup; */
153 /* for decompression, they are read from the SOS marker. */
154 /* The decompressor output side may not use these variables. */
155 int dc_tbl_no; /* DC entropy table selector (0..3) */
156 int ac_tbl_no; /* AC entropy table selector (0..3) */
158 /* Remaining fields should be treated as private by applications. */
160 /* These values are computed during compression or decompression startup: */
161 /* Component's size in data units.
162 * In lossy mode, any dummy blocks added to complete an MCU are not counted;
163 * therefore these values do not depend on whether a scan is interleaved or
164 * not. In lossless mode, these are always equal to the image width and
167 JDIMENSION width_in_blocks;
168 JDIMENSION height_in_blocks;
169 /* Size of a data unit in samples. Always DCTSIZE for lossy compression.
170 * For lossy decompression this is the size of the output from one DCT block,
171 * reflecting any scaling we choose to apply during the IDCT step.
172 * Values from 1 to 16 are supported. Note that different components may
173 * receive different IDCT scalings. In lossless mode, this is always equal
176 #if JPEG_LIB_VERSION >= 70
177 int DCT_h_scaled_size;
178 int DCT_v_scaled_size;
182 /* The downsampled dimensions are the component's actual, unpadded number
183 * of samples at the main buffer (preprocessing/compression interface), thus
184 * downsampled_width = ceil(image_width * Hi/Hmax)
185 * and similarly for height. For lossy decompression, IDCT scaling is
187 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]scaled_size/DCTSIZE)
188 * In lossless mode, these are always equal to the image width and height.
190 JDIMENSION downsampled_width; /* actual width in samples */
191 JDIMENSION downsampled_height; /* actual height in samples */
192 /* This flag is used only for decompression. In cases where some of the
193 * components will be ignored (eg grayscale output from YCbCr image),
194 * we can skip most computations for the unused components.
196 boolean component_needed; /* do we need the value of this component? */
198 /* These values are computed before starting a scan of the component. */
199 /* The decompressor output side may not use these variables. */
200 int MCU_width; /* number of data units per MCU, horizontally */
201 int MCU_height; /* number of data units per MCU, vertically */
202 int MCU_blocks; /* MCU_width * MCU_height */
203 int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_[h_]scaled_size */
204 int last_col_width; /* # of non-dummy data units across in last MCU */
205 int last_row_height; /* # of non-dummy data units down in last MCU */
207 /* Saved quantization table for component; NULL if none yet saved.
208 * See jdinput.c comments about the need for this information.
209 * This field is currently used only for decompression.
211 JQUANT_TBL *quant_table;
213 /* Private per-component storage for DCT or IDCT subsystem. */
215 } jpeg_component_info;
218 /* The script for encoding a multiple-scan file is an array of these: */
221 int comps_in_scan; /* number of components encoded in this scan */
222 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
223 int Ss, Se; /* progressive JPEG spectral selection parms
224 (Ss is the predictor selection value in
226 int Ah, Al; /* progressive JPEG successive approx. parms
227 (Al is the point transform value in lossless
231 /* The decompressor can save APPn and COM markers in a list of these: */
233 typedef struct jpeg_marker_struct *jpeg_saved_marker_ptr;
235 struct jpeg_marker_struct {
236 jpeg_saved_marker_ptr next; /* next in list, or NULL */
237 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */
238 unsigned int original_length; /* # bytes of data in the file */
239 unsigned int data_length; /* # bytes of data saved at data[] */
240 JOCTET *data; /* the data contained in the marker */
241 /* the marker length word is not counted in data_length or original_length */
244 /* Known color spaces. */
246 #define JCS_EXTENSIONS 1
247 #define JCS_ALPHA_EXTENSIONS 1
250 JCS_UNKNOWN, /* error/unspecified */
251 JCS_GRAYSCALE, /* monochrome */
252 JCS_RGB, /* red/green/blue as specified by the RGB_RED,
253 RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros */
254 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */
255 JCS_CMYK, /* C/M/Y/K */
256 JCS_YCCK, /* Y/Cb/Cr/K */
257 JCS_EXT_RGB, /* red/green/blue */
258 JCS_EXT_RGBX, /* red/green/blue/x */
259 JCS_EXT_BGR, /* blue/green/red */
260 JCS_EXT_BGRX, /* blue/green/red/x */
261 JCS_EXT_XBGR, /* x/blue/green/red */
262 JCS_EXT_XRGB, /* x/red/green/blue */
263 /* When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX, JCS_EXT_XBGR,
264 or JCS_EXT_XRGB during decompression, the X byte is undefined, and in
265 order to ensure the best performance, libjpeg-turbo can set that byte to
266 whatever value it wishes. Use the following colorspace constants to
267 ensure that the X byte is set to 0xFF, so that it can be interpreted as an
268 opaque alpha channel. */
269 JCS_EXT_RGBA, /* red/green/blue/alpha */
270 JCS_EXT_BGRA, /* blue/green/red/alpha */
271 JCS_EXT_ABGR, /* alpha/blue/green/red */
272 JCS_EXT_ARGB, /* alpha/red/green/blue */
273 JCS_RGB565 /* 5-bit red/6-bit green/5-bit blue
274 [decompression only] */
277 /* DCT/IDCT algorithm options. */
280 JDCT_ISLOW, /* accurate integer method */
281 JDCT_IFAST, /* less accurate integer method [legacy feature] */
282 JDCT_FLOAT /* floating-point method [legacy feature] */
285 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
286 #define JDCT_DEFAULT JDCT_ISLOW
288 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
289 #define JDCT_FASTEST JDCT_IFAST
292 /* Dithering options for decompression. */
295 JDITHER_NONE, /* no dithering */
296 JDITHER_ORDERED, /* simple ordered dither */
297 JDITHER_FS /* Floyd-Steinberg error diffusion dither */
301 /* Common fields between JPEG compression and decompression master structs. */
303 #define jpeg_common_fields \
304 struct jpeg_error_mgr *err; /* Error handler module */ \
305 struct jpeg_memory_mgr *mem; /* Memory manager module */ \
306 struct jpeg_progress_mgr *progress; /* Progress monitor, or NULL if none */ \
307 void *client_data; /* Available for use by application */ \
308 boolean is_decompressor; /* So common code can tell which is which */ \
309 int global_state /* For checking call sequence validity */
311 /* Routines that are to be used by both halves of the library are declared
312 * to receive a pointer to this structure. There are no actual instances of
313 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
315 struct jpeg_common_struct {
316 jpeg_common_fields; /* Fields common to both master struct types */
317 /* Additional fields follow in an actual jpeg_compress_struct or
318 * jpeg_decompress_struct. All three structs must agree on these
319 * initial fields! (This would be a lot cleaner in C++.)
323 typedef struct jpeg_common_struct *j_common_ptr;
324 typedef struct jpeg_compress_struct *j_compress_ptr;
325 typedef struct jpeg_decompress_struct *j_decompress_ptr;
327 typedef struct _Pick_Color_
340 /* Master record for a compression instance */
342 struct jpeg_compress_struct {
343 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */
345 /* Destination for compressed data */
346 struct jpeg_destination_mgr *dest;
348 /* Description of source image --- these fields must be filled in by
349 * outer application before starting compression. in_color_space must
350 * be correct before you can even call jpeg_set_defaults().
353 JDIMENSION image_width; /* input image width */
354 JDIMENSION image_height; /* input image height */
355 int input_components; /* # of color components in input image */
356 J_COLOR_SPACE in_color_space; /* colorspace of input image */
358 double input_gamma; /* image gamma of input image */
360 /* Compression parameters --- these fields must be set before calling
361 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
362 * initialize everything to reasonable defaults, then changing anything
363 * the application specifically wants to change. That way you won't get
364 * burnt when new parameters are added. Also note that there are several
365 * helper routines to simplify changing parameters.
368 #if JPEG_LIB_VERSION >= 70
369 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
371 JDIMENSION jpeg_width; /* scaled JPEG image width */
372 JDIMENSION jpeg_height; /* scaled JPEG image height */
373 /* Dimensions of actual JPEG image that will be written to file,
374 * derived from input dimensions by scaling factors above.
375 * These fields are computed by jpeg_start_compress().
376 * You can also use jpeg_calc_jpeg_dimensions() to determine these values
377 * in advance of calling jpeg_start_compress().
381 int data_precision; /* bits of precision in image data */
383 int num_components; /* # of color components in JPEG image */
384 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
386 jpeg_component_info *comp_info;
387 /* comp_info[i] describes component that appears i'th in SOF */
389 JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
390 #if JPEG_LIB_VERSION >= 70
391 int q_scale_factor[NUM_QUANT_TBLS];
393 /* ptrs to coefficient quantization tables, or NULL if not defined,
394 * and corresponding scale factors (percentage, initialized 100).
397 JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
398 JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
399 /* ptrs to Huffman coding tables, or NULL if not defined */
401 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
402 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
403 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
405 int num_scans; /* # of entries in scan_info array */
406 const jpeg_scan_info *scan_info; /* script for multi-scan file, or NULL */
407 /* The default value of scan_info is NULL, which causes a single-scan
408 * sequential JPEG file to be emitted. To create a multi-scan file,
409 * set num_scans and scan_info to point to an array of scan definitions.
412 boolean raw_data_in; /* TRUE=caller supplies downsampled data */
413 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
414 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */
415 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
416 #if JPEG_LIB_VERSION >= 70
417 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
419 int smoothing_factor; /* 1..100, or 0 for no input smoothing */
420 J_DCT_METHOD dct_method; /* DCT algorithm selector */
422 /* The restart interval can be specified in absolute MCUs by setting
423 * restart_interval, or in MCU rows by setting restart_in_rows
424 * (in which case the correct restart_interval will be figured
427 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
428 int restart_in_rows; /* if > 0, MCU rows per restart interval */
430 /* Parameters controlling emission of special markers. */
432 boolean write_JFIF_header; /* should a JFIF marker be written? */
433 UINT8 JFIF_major_version; /* What to write for the JFIF version number */
434 UINT8 JFIF_minor_version;
435 /* These three values are not used by the JPEG code, merely copied */
436 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
437 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
438 /* ratio is defined by X_density/Y_density even when density_unit=0. */
439 UINT8 density_unit; /* JFIF code for pixel size units */
440 UINT16 X_density; /* Horizontal pixel density */
441 UINT16 Y_density; /* Vertical pixel density */
442 boolean write_Adobe_marker; /* should an Adobe marker be written? */
444 /* State variable: index of next scanline to be written to
445 * jpeg_write_scanlines(). Application may use this to control its
446 * processing loop, e.g., "while (next_scanline < image_height)".
449 JDIMENSION next_scanline; /* 0 .. image_height-1 */
451 /* Remaining fields are known throughout compressor, but generally
452 * should not be touched by a surrounding application.
456 * These fields are computed during compression startup
458 boolean progressive_mode; /* TRUE if scan script uses progressive mode */
459 int max_h_samp_factor; /* largest h_samp_factor */
460 int max_v_samp_factor; /* largest v_samp_factor */
462 #if JPEG_LIB_VERSION >= 70
463 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
464 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
467 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coefficient or
468 difference controller */
469 /* The coefficient or difference controller receives data in units of MCU
470 * rows as defined for fully interleaved scans (whether the JPEG file is
471 * interleaved or not). In lossy mode, there are v_samp_factor * DCTSIZE
472 * sample rows of each component in an "iMCU" (interleaved MCU) row. In
473 * lossless mode, total_iMCU_rows is always equal to the image height.
477 * These fields are valid during any one scan.
478 * They describe the components and MCUs actually appearing in the scan.
480 int comps_in_scan; /* # of JPEG components in this scan */
481 jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
482 /* *cur_comp_info[i] describes component that appears i'th in SOS */
484 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
485 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
487 int blocks_in_MCU; /* # of data units per MCU */
488 int MCU_membership[C_MAX_BLOCKS_IN_MCU];
489 /* MCU_membership[i] is index in cur_comp_info of component owning */
490 /* i'th data unit in an MCU */
492 int Ss, Se, Ah, Al; /* progressive/lossless JPEG parameters for
495 #if JPEG_LIB_VERSION >= 80
496 int block_size; /* the basic DCT block size: 1..16 */
497 const int *natural_order; /* natural-order position array */
498 int lim_Se; /* min( Se, DCTSIZE2-1 ) */
502 * Links to compression subobjects (methods and private variables of modules)
504 struct jpeg_comp_master *master;
505 struct jpeg_c_main_controller *main;
506 struct jpeg_c_prep_controller *prep;
507 struct jpeg_c_coef_controller *coef;
508 struct jpeg_marker_writer *marker;
509 struct jpeg_color_converter *cconvert;
510 struct jpeg_downsampler *downsample;
511 struct jpeg_forward_dct *fdct;
512 struct jpeg_entropy_encoder *entropy;
513 jpeg_scan_info *script_space; /* workspace for jpeg_simple_progression */
514 int script_space_size;
518 /* Master record for a decompression instance */
520 struct jpeg_decompress_struct {
521 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
523 /* Source of compressed data */
524 struct jpeg_source_mgr *src;
526 /* Basic description of image --- filled in by jpeg_read_header(). */
527 /* Application may inspect these values to decide how to process image. */
529 JDIMENSION image_width; /* nominal image width (from SOF marker) */
530 JDIMENSION image_height; /* nominal image height */
531 int num_components; /* # of color components in JPEG image */
532 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
534 /* Decompression processing parameters --- these fields must be set before
535 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
536 * them to default values.
539 J_COLOR_SPACE out_color_space; /* colorspace for output */
541 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
543 #if COLOR_PICKER_ENABLE == 1
544 unsigned int region_x, region_y, region_w, region_h; /* if region_w && region_h > 0, then use this region to decode. scale above is done prior to region select */
547 double output_gamma; /* image gamma wanted in output */
549 boolean buffered_image; /* TRUE=multiple output passes */
550 boolean raw_data_out; /* TRUE=downsampled data wanted */
552 J_DCT_METHOD dct_method; /* IDCT algorithm selector */
553 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
554 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
556 boolean quantize_colors; /* TRUE=colormapped output wanted */
557 /* the following are ignored if not quantize_colors: */
558 J_DITHER_MODE dither_mode; /* type of color dithering to use */
559 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
560 int desired_number_of_colors; /* max # colors to use in created colormap */
561 /* these are significant only in buffered-image mode: */
562 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
563 boolean enable_external_quant;/* enable future use of external colormap */
564 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
566 /* Description of actual output image that will be returned to application.
567 * These fields are computed by jpeg_start_decompress().
568 * You can also use jpeg_calc_output_dimensions() to determine these values
569 * in advance of calling jpeg_start_decompress().
572 JDIMENSION output_width; /* scaled image width */
573 JDIMENSION output_height; /* scaled image height */
574 int out_color_components; /* # of color components in out_color_space */
575 int output_components; /* # of color components returned */
576 /* output_components is 1 (a colormap index) when quantizing colors;
577 * otherwise it equals out_color_components.
579 int rec_outbuf_height; /* min recommended height of scanline buffer */
580 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
581 * high, space and time will be wasted due to unnecessary data copying.
582 * Usually rec_outbuf_height will be 1 or 2, at most 4.
585 /* When quantizing colors, the output colormap is described by these fields.
586 * The application can supply a colormap by setting colormap non-NULL before
587 * calling jpeg_start_decompress; otherwise a colormap is created during
588 * jpeg_start_decompress or jpeg_start_output.
589 * The map has out_color_components rows and actual_number_of_colors columns.
591 int actual_number_of_colors; /* number of entries in use */
592 JSAMPARRAY colormap; /* The color map as a 2-D pixel array
593 If data_precision is 12 or 16, then this is
594 actually a J12SAMPARRAY or a J16SAMPARRAY,
595 so callers must type-cast it in order to
596 read/write 12-bit or 16-bit samples from/to
599 /* State variables: these variables indicate the progress of decompression.
600 * The application may examine these but must not modify them.
603 /* Row index of next scanline to be read from jpeg_read_scanlines().
604 * Application may use this to control its processing loop, e.g.,
605 * "while (output_scanline < output_height)".
607 JDIMENSION output_scanline; /* 0 .. output_height-1 */
609 /* Current input scan number and number of iMCU rows completed in scan.
610 * These indicate the progress of the decompressor input side.
612 int input_scan_number; /* Number of SOS markers seen so far */
613 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
615 /* The "output scan number" is the notional scan being displayed by the
616 * output side. The decompressor will not allow output scan/row number
617 * to get ahead of input scan/row, but it can fall arbitrarily far behind.
619 int output_scan_number; /* Nominal scan number being displayed */
620 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
622 /* Current progression status. coef_bits[c][i] indicates the precision
623 * with which component c's DCT coefficient i (in zigzag order) is known.
624 * It is -1 when no data has yet been received, otherwise it is the point
625 * transform (shift) value for the most recent scan of the coefficient
626 * (thus, 0 at completion of the progression).
627 * This pointer is NULL when reading a non-progressive file.
629 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
631 /* Internal JPEG parameters --- the application usually need not look at
632 * these fields. Note that the decompressor output side may not use
633 * any parameters that can change between scans.
636 /* Quantization and Huffman tables are carried forward across input
637 * datastreams when processing abbreviated JPEG datastreams.
640 JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
641 /* ptrs to coefficient quantization tables, or NULL if not defined */
643 JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
644 JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
645 /* ptrs to Huffman coding tables, or NULL if not defined */
647 /* These parameters are never carried across datastreams, since they
648 * are given in SOF/SOS markers or defined to be reset by SOI.
651 int data_precision; /* bits of precision in image data */
653 jpeg_component_info *comp_info;
654 /* comp_info[i] describes component that appears i'th in SOF */
656 #if JPEG_LIB_VERSION >= 80
657 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */
659 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
660 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
662 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
663 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
664 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
666 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
668 /* These fields record data obtained from optional markers recognized by
671 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
672 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
673 UINT8 JFIF_major_version; /* JFIF version number */
674 UINT8 JFIF_minor_version;
675 UINT8 density_unit; /* JFIF code for pixel size units */
676 UINT16 X_density; /* Horizontal pixel density */
677 UINT16 Y_density; /* Vertical pixel density */
678 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
679 UINT8 Adobe_transform; /* Color transform code from Adobe marker */
681 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
683 /* Aside from the specific data retained from APPn markers known to the
684 * library, the uninterpreted contents of any or all APPn and COM markers
685 * can be saved in a list for examination by the application.
687 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
689 /* Remaining fields are known throughout decompressor, but generally
690 * should not be touched by a surrounding application.
694 * These fields are computed during decompression startup
696 int max_h_samp_factor; /* largest h_samp_factor */
697 int max_v_samp_factor; /* largest v_samp_factor */
699 #if JPEG_LIB_VERSION >= 70
700 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
701 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
703 int min_DCT_scaled_size; /* smallest DCT_scaled_size of any component */
706 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
707 /* The coefficient or difference controller's input and output progress is
708 * measured in units of "iMCU" (interleaved MCU) rows. These are the same as
709 * MCU rows in fully interleaved JPEG scans, but are used whether the scan is
710 * interleaved or not. In lossy mode, we define an iMCU row as v_samp_factor
711 * DCT block rows of each component. Therefore, the IDCT output contains
712 * v_samp_factor*DCT_[v_]scaled_size sample rows of a component per iMCU row.
713 * In lossless mode, total_iMCU_rows is always equal to the image height.
716 JSAMPLE *sample_range_limit; /* table for fast range-limiting
717 If data_precision is 12 or 16, then this is
718 actually a J12SAMPLE pointer or a J16SAMPLE
719 pointer, so callers must type-cast it in
720 order to read 12-bit or 16-bit samples from
724 * These fields are valid during any one scan.
725 * They describe the components and MCUs actually appearing in the scan.
726 * Note that the decompressor output side must not use these fields.
728 int comps_in_scan; /* # of JPEG components in this scan */
729 jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
730 /* *cur_comp_info[i] describes component that appears i'th in SOS */
732 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
733 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
735 int blocks_in_MCU; /* # of data units per MCU */
736 int MCU_membership[D_MAX_BLOCKS_IN_MCU];
737 /* MCU_membership[i] is index in cur_comp_info of component owning */
738 /* i'th data unit in an MCU */
740 int Ss, Se, Ah, Al; /* progressive/lossless JPEG parameters for
743 #if JPEG_LIB_VERSION >= 80
744 /* These fields are derived from Se of first SOS marker.
746 int block_size; /* the basic DCT block size: 1..16 */
747 const int *natural_order; /* natural-order position array for entropy decode */
748 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */
751 /* This field is shared between entropy decoder and marker parser.
752 * It is either zero or the code of a JPEG marker that has been
753 * read from the data source, but has not yet been processed.
758 * Links to decompression subobjects (methods, private variables of modules)
760 struct jpeg_decomp_master *master;
761 struct jpeg_d_main_controller *main;
762 struct jpeg_d_coef_controller *coef;
763 struct jpeg_d_post_controller *post;
764 struct jpeg_input_controller *inputctl;
765 struct jpeg_marker_reader *marker;
766 struct jpeg_entropy_decoder *entropy;
767 struct jpeg_inverse_dct *idct;
768 struct jpeg_upsampler *upsample;
769 struct jpeg_color_deconverter *cconvert;
770 struct jpeg_color_quantizer *cquantize;
772 #if COLOR_PICKER_ENABLE == 1
773 struct _Pick_Color_ *pick_color_data;
778 /* "Object" declarations for JPEG modules that may be supplied or called
779 * directly by the surrounding application.
780 * As with all objects in the JPEG library, these structs only define the
781 * publicly visible methods and state variables of a module. Additional
782 * private fields may exist after the public ones.
786 /* Error handler object */
788 struct jpeg_error_mgr {
789 /* Error exit handler: does not return to caller */
790 void (*error_exit) (j_common_ptr cinfo);
791 /* Conditionally emit a trace or warning message */
792 void (*emit_message) (j_common_ptr cinfo, int msg_level);
793 /* Routine that actually outputs a trace or error message */
794 void (*output_message) (j_common_ptr cinfo);
795 /* Format a message string for the most recent JPEG error or message */
796 void (*format_message) (j_common_ptr cinfo, char *buffer);
797 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
798 /* Reset error state variables at start of a new image */
799 void (*reset_error_mgr) (j_common_ptr cinfo);
801 /* The message ID code and any parameters are saved here.
802 * A message can have one string parameter or up to 8 int parameters.
805 #define JMSG_STR_PARM_MAX 80
808 char s[JMSG_STR_PARM_MAX];
811 /* Standard state variables for error facility */
813 int trace_level; /* max msg_level that will be displayed */
815 /* For recoverable corrupt-data errors, we emit a warning message,
816 * but keep going unless emit_message chooses to abort. emit_message
817 * should count warnings in num_warnings. The surrounding application
818 * can check for bad data by seeing if num_warnings is nonzero at the
821 long num_warnings; /* number of corrupt-data warnings */
823 /* These fields point to the table(s) of error message strings.
824 * An application can change the table pointer to switch to a different
825 * message list (typically, to change the language in which errors are
826 * reported). Some applications may wish to add additional error codes
827 * that will be handled by the JPEG library error mechanism; the second
828 * table pointer is used for this purpose.
830 * First table includes all errors generated by JPEG library itself.
831 * Error code 0 is reserved for a "no such error string" message.
833 const char * const *jpeg_message_table; /* Library errors */
834 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
835 /* Second table can be added by application (see cjpeg/djpeg for example).
836 * It contains strings numbered first_addon_message..last_addon_message.
838 const char * const *addon_message_table; /* Non-library errors */
839 int first_addon_message; /* code for first string in addon table */
840 int last_addon_message; /* code for last string in addon table */
844 /* Progress monitor object */
846 struct jpeg_progress_mgr {
847 void (*progress_monitor) (j_common_ptr cinfo);
849 long pass_counter; /* work units completed in this pass */
850 long pass_limit; /* total number of work units in this pass */
851 int completed_passes; /* passes completed so far */
852 int total_passes; /* total number of passes expected */
856 /* Data destination object for compression */
858 struct jpeg_destination_mgr {
859 JOCTET *next_output_byte; /* => next byte to write in buffer */
860 size_t free_in_buffer; /* # of byte spaces remaining in buffer */
862 void (*init_destination) (j_compress_ptr cinfo);
863 boolean (*empty_output_buffer) (j_compress_ptr cinfo);
864 void (*term_destination) (j_compress_ptr cinfo);
868 /* Data source object for decompression */
870 struct jpeg_source_mgr {
871 const JOCTET *next_input_byte; /* => next byte to read from buffer */
872 size_t bytes_in_buffer; /* # of bytes remaining in buffer */
874 void (*init_source) (j_decompress_ptr cinfo);
875 boolean (*fill_input_buffer) (j_decompress_ptr cinfo);
876 void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes);
877 boolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired);
878 void (*term_source) (j_decompress_ptr cinfo);
882 /* Memory manager object.
883 * Allocates "small" objects (a few K total), "large" objects (tens of K),
884 * and "really big" objects (virtual arrays with backing store if needed).
885 * The memory manager does not allow individual objects to be freed; rather,
886 * each created object is assigned to a pool, and whole pools can be freed
887 * at once. This is faster and more convenient than remembering exactly what
888 * to free, especially where malloc()/free() are not too speedy.
889 * NB: alloc routines never return NULL. They exit to error_exit if not
893 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
894 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
895 #define JPOOL_NUMPOOLS 2
897 typedef struct jvirt_sarray_control *jvirt_sarray_ptr;
898 typedef struct jvirt_barray_control *jvirt_barray_ptr;
901 struct jpeg_memory_mgr {
902 /* Method pointers */
903 void *(*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject);
904 void *(*alloc_large) (j_common_ptr cinfo, int pool_id,
905 size_t sizeofobject);
906 /* If cinfo->data_precision is 12 or 16, then this method and the
907 * access_virt_sarray method actually return a J12SAMPARRAY or a
908 * J16SAMPARRAY, so callers must type-cast the return value in order to
909 * read/write 12-bit or 16-bit samples from/to the array.
911 JSAMPARRAY (*alloc_sarray) (j_common_ptr cinfo, int pool_id,
912 JDIMENSION samplesperrow, JDIMENSION numrows);
913 JBLOCKARRAY (*alloc_barray) (j_common_ptr cinfo, int pool_id,
914 JDIMENSION blocksperrow, JDIMENSION numrows);
915 jvirt_sarray_ptr (*request_virt_sarray) (j_common_ptr cinfo, int pool_id,
917 JDIMENSION samplesperrow,
919 JDIMENSION maxaccess);
920 jvirt_barray_ptr (*request_virt_barray) (j_common_ptr cinfo, int pool_id,
922 JDIMENSION blocksperrow,
924 JDIMENSION maxaccess);
925 void (*realize_virt_arrays) (j_common_ptr cinfo);
926 JSAMPARRAY (*access_virt_sarray) (j_common_ptr cinfo, jvirt_sarray_ptr ptr,
927 JDIMENSION start_row, JDIMENSION num_rows,
929 JBLOCKARRAY (*access_virt_barray) (j_common_ptr cinfo, jvirt_barray_ptr ptr,
930 JDIMENSION start_row, JDIMENSION num_rows,
932 void (*free_pool) (j_common_ptr cinfo, int pool_id);
933 void (*self_destruct) (j_common_ptr cinfo);
935 /* Limit on memory allocation for this JPEG object. (Note that this is
936 * merely advisory, not a guaranteed maximum; it only affects the space
937 * used for virtual-array buffers.) May be changed by outer application
938 * after creating the JPEG object.
940 long max_memory_to_use;
942 /* Maximum allocation request accepted by alloc_large. */
943 long max_alloc_chunk;
947 /* Routine signature for application-supplied marker processing methods.
948 * Need not pass marker code since it is stored in cinfo->unread_marker.
950 typedef boolean (*jpeg_marker_parser_method) (j_decompress_ptr cinfo);
953 /* Originally, this macro was used as a way of defining function prototypes
954 * for both modern compilers as well as older compilers that did not support
955 * prototype parameters. libjpeg-turbo has never supported these older,
956 * non-ANSI compilers, but the macro is still included because there is some
957 * software out there that uses it.
960 #define JPP(arglist) arglist
963 /* Default error-management setup */
964 EXTERN(struct jpeg_error_mgr *) jpeg_std_error(struct jpeg_error_mgr *err);
966 /* Initialization of JPEG compression objects.
967 * jpeg_create_compress() and jpeg_create_decompress() are the exported
968 * names that applications should call. These expand to calls on
969 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
970 * passed for version mismatch checking.
971 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
973 #define jpeg_create_compress(cinfo) \
974 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
975 (size_t)sizeof(struct jpeg_compress_struct))
976 #define jpeg_create_decompress(cinfo) \
977 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
978 (size_t)sizeof(struct jpeg_decompress_struct))
979 EXTERN(void) jpeg_CreateCompress(j_compress_ptr cinfo, int version,
981 EXTERN(void) jpeg_CreateDecompress(j_decompress_ptr cinfo, int version,
983 /* Destruction of JPEG compression objects */
984 EXTERN(void) jpeg_destroy_compress(j_compress_ptr cinfo);
985 EXTERN(void) jpeg_destroy_decompress(j_decompress_ptr cinfo);
987 /* Standard data source and destination managers: stdio streams. */
988 /* Caller is responsible for opening the file before and closing after. */
989 EXTERN(void) jpeg_stdio_dest(j_compress_ptr cinfo, FILE *outfile);
990 EXTERN(void) jpeg_stdio_src(j_decompress_ptr cinfo, FILE *infile);
992 /* Data source and destination managers: memory buffers. */
993 EXTERN(void) jpeg_mem_dest(j_compress_ptr cinfo, unsigned char **outbuffer,
994 unsigned long *outsize);
995 EXTERN(void) jpeg_mem_src(j_decompress_ptr cinfo,
996 const unsigned char *inbuffer, unsigned long insize);
998 /* Default parameter setup for compression */
999 EXTERN(void) jpeg_set_defaults(j_compress_ptr cinfo);
1000 /* Compression parameter setup aids */
1001 EXTERN(void) jpeg_set_colorspace(j_compress_ptr cinfo,
1002 J_COLOR_SPACE colorspace);
1003 EXTERN(void) jpeg_default_colorspace(j_compress_ptr cinfo);
1004 EXTERN(void) jpeg_set_quality(j_compress_ptr cinfo, int quality,
1005 boolean force_baseline);
1006 EXTERN(void) jpeg_set_linear_quality(j_compress_ptr cinfo, int scale_factor,
1007 boolean force_baseline);
1008 #if JPEG_LIB_VERSION >= 70
1009 EXTERN(void) jpeg_default_qtables(j_compress_ptr cinfo,
1010 boolean force_baseline);
1012 EXTERN(void) jpeg_add_quant_table(j_compress_ptr cinfo, int which_tbl,
1013 const unsigned int *basic_table,
1014 int scale_factor, boolean force_baseline);
1015 EXTERN(int) jpeg_quality_scaling(int quality);
1016 EXTERN(void) jpeg_enable_lossless(j_compress_ptr cinfo,
1017 int predictor_selection_value,
1018 int point_transform);
1019 EXTERN(void) jpeg_simple_progression(j_compress_ptr cinfo);
1020 EXTERN(void) jpeg_suppress_tables(j_compress_ptr cinfo, boolean suppress);
1021 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table(j_common_ptr cinfo);
1022 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table(j_common_ptr cinfo);
1024 /* Main entry points for compression */
1025 EXTERN(void) jpeg_start_compress(j_compress_ptr cinfo,
1026 boolean write_all_tables);
1027 EXTERN(JDIMENSION) jpeg_write_scanlines(j_compress_ptr cinfo,
1028 JSAMPARRAY scanlines,
1029 JDIMENSION num_lines);
1030 EXTERN(JDIMENSION) jpeg12_write_scanlines(j_compress_ptr cinfo,
1031 J12SAMPARRAY scanlines,
1032 JDIMENSION num_lines);
1033 EXTERN(JDIMENSION) jpeg16_write_scanlines(j_compress_ptr cinfo,
1034 J16SAMPARRAY scanlines,
1035 JDIMENSION num_lines);
1036 EXTERN(void) jpeg_finish_compress(j_compress_ptr cinfo);
1038 #if JPEG_LIB_VERSION >= 70
1039 /* Precalculate JPEG dimensions for current compression parameters. */
1040 EXTERN(void) jpeg_calc_jpeg_dimensions(j_compress_ptr cinfo);
1043 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
1044 EXTERN(JDIMENSION) jpeg_write_raw_data(j_compress_ptr cinfo, JSAMPIMAGE data,
1045 JDIMENSION num_lines);
1046 EXTERN(JDIMENSION) jpeg12_write_raw_data(j_compress_ptr cinfo,
1048 JDIMENSION num_lines);
1050 /* Write a special marker. See libjpeg.txt concerning safe usage. */
1051 EXTERN(void) jpeg_write_marker(j_compress_ptr cinfo, int marker,
1052 const JOCTET *dataptr, unsigned int datalen);
1053 /* Same, but piecemeal. */
1054 EXTERN(void) jpeg_write_m_header(j_compress_ptr cinfo, int marker,
1055 unsigned int datalen);
1056 EXTERN(void) jpeg_write_m_byte(j_compress_ptr cinfo, int val);
1058 /* Alternate compression function: just write an abbreviated table file */
1059 EXTERN(void) jpeg_write_tables(j_compress_ptr cinfo);
1061 /* Write ICC profile. See libjpeg.txt for usage information. */
1062 EXTERN(void) jpeg_write_icc_profile(j_compress_ptr cinfo,
1063 const JOCTET *icc_data_ptr,
1064 unsigned int icc_data_len);
1067 /* Decompression startup: read start of JPEG datastream to see what's there */
1068 EXTERN(int) jpeg_read_header(j_decompress_ptr cinfo, boolean require_image);
1069 /* Return value is one of: */
1070 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
1071 #define JPEG_HEADER_OK 1 /* Found valid image datastream */
1072 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
1073 /* If you pass require_image = TRUE (normal case), you need not check for
1074 * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
1075 * JPEG_SUSPENDED is only possible if you use a data source module that can
1076 * give a suspension return (the stdio source module doesn't).
1079 /* Main entry points for decompression */
1080 EXTERN(boolean) jpeg_start_decompress(j_decompress_ptr cinfo);
1081 EXTERN(JDIMENSION) jpeg_read_scanlines(j_decompress_ptr cinfo,
1082 JSAMPARRAY scanlines,
1083 JDIMENSION max_lines);
1084 EXTERN(JDIMENSION) jpeg12_read_scanlines(j_decompress_ptr cinfo,
1085 J12SAMPARRAY scanlines,
1086 JDIMENSION max_lines);
1087 EXTERN(JDIMENSION) jpeg16_read_scanlines(j_decompress_ptr cinfo,
1088 J16SAMPARRAY scanlines,
1089 JDIMENSION max_lines);
1090 EXTERN(JDIMENSION) jpeg_skip_scanlines(j_decompress_ptr cinfo,
1091 JDIMENSION num_lines);
1092 EXTERN(JDIMENSION) jpeg12_skip_scanlines(j_decompress_ptr cinfo,
1093 JDIMENSION num_lines);
1094 EXTERN(void) jpeg_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
1096 EXTERN(void) jpeg12_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
1098 EXTERN(boolean) jpeg_finish_decompress(j_decompress_ptr cinfo);
1100 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
1101 EXTERN(JDIMENSION) jpeg_read_raw_data(j_decompress_ptr cinfo, JSAMPIMAGE data,
1102 JDIMENSION max_lines);
1103 EXTERN(JDIMENSION) jpeg12_read_raw_data(j_decompress_ptr cinfo,
1105 JDIMENSION max_lines);
1107 /* Additional entry points for buffered-image mode. */
1108 EXTERN(boolean) jpeg_has_multiple_scans(j_decompress_ptr cinfo);
1109 EXTERN(boolean) jpeg_start_output(j_decompress_ptr cinfo, int scan_number);
1110 EXTERN(boolean) jpeg_finish_output(j_decompress_ptr cinfo);
1111 EXTERN(boolean) jpeg_input_complete(j_decompress_ptr cinfo);
1112 EXTERN(void) jpeg_new_colormap(j_decompress_ptr cinfo);
1113 EXTERN(int) jpeg_consume_input(j_decompress_ptr cinfo);
1114 /* Return value is one of: */
1115 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
1116 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */
1117 #define JPEG_REACHED_EOI 2 /* Reached end of image */
1118 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
1119 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
1121 /* Precalculate output dimensions for current decompression parameters. */
1122 #if JPEG_LIB_VERSION >= 80
1123 EXTERN(void) jpeg_core_output_dimensions(j_decompress_ptr cinfo);
1125 EXTERN(void) jpeg_calc_output_dimensions(j_decompress_ptr cinfo);
1127 /* Control saving of COM and APPn markers into marker_list. */
1128 EXTERN(void) jpeg_save_markers(j_decompress_ptr cinfo, int marker_code,
1129 unsigned int length_limit);
1131 /* Install a special processing method for COM or APPn markers. */
1132 EXTERN(void) jpeg_set_marker_processor(j_decompress_ptr cinfo,
1134 jpeg_marker_parser_method routine);
1136 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
1137 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients(j_decompress_ptr cinfo);
1138 EXTERN(void) jpeg_write_coefficients(j_compress_ptr cinfo,
1139 jvirt_barray_ptr *coef_arrays);
1140 EXTERN(void) jpeg_copy_critical_parameters(j_decompress_ptr srcinfo,
1141 j_compress_ptr dstinfo);
1143 /* If you choose to abort compression or decompression before completing
1144 * jpeg_finish_(de)compress, then you need to clean up to release memory,
1145 * temporary files, etc. You can just call jpeg_destroy_(de)compress
1146 * if you're done with the JPEG object, but if you want to clean it up and
1147 * reuse it, call this:
1149 EXTERN(void) jpeg_abort_compress(j_compress_ptr cinfo);
1150 EXTERN(void) jpeg_abort_decompress(j_decompress_ptr cinfo);
1152 /* Generic versions of jpeg_abort and jpeg_destroy that work on either
1153 * flavor of JPEG object. These may be more convenient in some places.
1155 EXTERN(void) jpeg_abort(j_common_ptr cinfo);
1156 EXTERN(void) jpeg_destroy(j_common_ptr cinfo);
1158 /* Default restart-marker-resync procedure for use by data source modules */
1159 EXTERN(boolean) jpeg_resync_to_restart(j_decompress_ptr cinfo, int desired);
1161 /* Read ICC profile. See libjpeg.txt for usage information. */
1162 EXTERN(boolean) jpeg_read_icc_profile(j_decompress_ptr cinfo,
1163 JOCTET **icc_data_ptr,
1164 unsigned int *icc_data_len);
1167 /* These marker codes are exported since applications and data source modules
1168 * are likely to want to use them.
1171 #define JPEG_RST0 0xD0 /* RST0 marker code */
1172 #define JPEG_EOI 0xD9 /* EOI marker code */
1173 #define JPEG_APP0 0xE0 /* APP0 marker code */
1174 #define JPEG_COM 0xFE /* COM marker code */
1177 /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1178 * for structure definitions that are never filled in, keep it quiet by
1179 * supplying dummy definitions for the various substructures.
1182 #ifdef INCOMPLETE_TYPES_BROKEN
1183 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
1184 struct jvirt_sarray_control { long dummy; };
1185 struct jvirt_barray_control { long dummy; };
1186 struct jpeg_comp_master { long dummy; };
1187 struct jpeg_c_main_controller { long dummy; };
1188 struct jpeg_c_prep_controller { long dummy; };
1189 struct jpeg_c_coef_controller { long dummy; };
1190 struct jpeg_marker_writer { long dummy; };
1191 struct jpeg_color_converter { long dummy; };
1192 struct jpeg_downsampler { long dummy; };
1193 struct jpeg_forward_dct { long dummy; };
1194 struct jpeg_entropy_encoder { long dummy; };
1195 struct jpeg_decomp_master { long dummy; };
1196 struct jpeg_d_main_controller { long dummy; };
1197 struct jpeg_d_coef_controller { long dummy; };
1198 struct jpeg_d_post_controller { long dummy; };
1199 struct jpeg_input_controller { long dummy; };
1200 struct jpeg_marker_reader { long dummy; };
1201 struct jpeg_entropy_decoder { long dummy; };
1202 struct jpeg_inverse_dct { long dummy; };
1203 struct jpeg_upsampler { long dummy; };
1204 struct jpeg_color_deconverter { long dummy; };
1205 struct jpeg_color_quantizer { long dummy; };
1206 #endif /* JPEG_INTERNALS */
1207 #endif /* INCOMPLETE_TYPES_BROKEN */
1211 * The JPEG library modules define JPEG_INTERNALS before including this file.
1212 * The internal structure declarations are read only when that is true.
1213 * Applications using the library should not include jpegint.h, but may wish
1214 * to include jerror.h.
1217 #ifdef JPEG_INTERNALS
1218 #include "jpegint.h" /* fetch private declarations */
1219 #include "jerror.h" /* fetch error codes too */
1223 #ifndef DONT_USE_EXTERN_C
1228 #endif /* JPEGLIB_H */