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0001 /*
0002  * jpeglib.h
0003  *
0004  * This file was part of the Independent JPEG Group's software:
0005  * Copyright (C) 1991-1998, Thomas G. Lane.
0006  * Modified 2002-2009 by Guido Vollbeding.
0007  * Lossless JPEG Modifications:
0008  * Copyright (C) 1999, Ken Murchison.
0009  * libjpeg-turbo Modifications:
0010  * Copyright (C) 2009-2011, 2013-2014, 2016-2017, 2020, 2022-2024,
0011              D. R. Commander.
0012  * Copyright (C) 2015, Google, Inc.
0013  * For conditions of distribution and use, see the accompanying README.ijg
0014  * file.
0015  *
0016  * This file defines the application interface for the JPEG library.
0017  * Most applications using the library need only include this file,
0018  * and perhaps jerror.h if they want to know the exact error codes.
0019  */
0020 
0021 /* NOTE: This header file does not include stdio.h, despite the fact that it
0022  * uses FILE and size_t.  That is by design, since the libjpeg API predates the
0023  * widespread adoption of ANSI/ISO C.  Referring to libjpeg.txt, it is a
0024  * documented requirement that calling programs "include system headers that
0025  * define at least the typedefs FILE and size_t" before including jpeglib.h.
0026  * Technically speaking, changing that requirement by including stdio.h here
0027  * would break backward API compatibility.  Please do not file bug reports,
0028  * feature requests, or pull requests regarding this.
0029  */
0030 
0031 #ifndef JPEGLIB_H
0032 #define JPEGLIB_H
0033 
0034 /*
0035  * First we include the configuration files that record how this
0036  * installation of the JPEG library is set up.  jconfig.h can be
0037  * generated automatically for many systems.  jmorecfg.h contains
0038  * manual configuration options that most people need not worry about.
0039  */
0040 
0041 #ifndef JCONFIG_INCLUDED        /* in case jinclude.h already did */
0042 #include "jconfig.h"            /* widely used configuration options */
0043 #endif
0044 #include "jmorecfg.h"           /* seldom changed options */
0045 
0046 
0047 #ifdef __cplusplus
0048 #ifndef DONT_USE_EXTERN_C
0049 extern "C" {
0050 #endif
0051 #endif
0052 
0053 
0054 /* Various constants determining the sizes of things.
0055  * All of these are specified by the JPEG standard, so don't change them
0056  * if you want to be compatible.
0057  */
0058 
0059 /* NOTE: In lossless mode, an MCU contains one or more samples rather than one
0060  * or more 8x8 DCT blocks, so the term "data unit" is used to generically
0061  * describe a sample in lossless mode or an 8x8 DCT block in lossy mode.  To
0062  * preserve backward API/ABI compatibility, the field and macro names retain
0063  * the "block" terminology.
0064  */
0065 
0066 #define DCTSIZE             8   /* The basic DCT block is 8x8 samples */
0067 #define DCTSIZE2            64  /* DCTSIZE squared; # of elements in a block */
0068 #define NUM_QUANT_TBLS      4   /* Quantization tables are numbered 0..3 */
0069 #define NUM_HUFF_TBLS       4   /* Huffman tables are numbered 0..3 */
0070 #define NUM_ARITH_TBLS      16  /* Arith-coding tables are numbered 0..15 */
0071 #define MAX_COMPS_IN_SCAN   4   /* JPEG limit on # of components in one scan */
0072 #define MAX_SAMP_FACTOR     4   /* JPEG limit on sampling factors */
0073 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
0074  * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
0075  * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
0076  * to handle it.  We even let you do this from the jconfig.h file.  However,
0077  * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
0078  * sometimes emits noncompliant files doesn't mean you should too.
0079  */
0080 #define C_MAX_BLOCKS_IN_MCU   10 /* compressor's limit on data units/MCU */
0081 #ifndef D_MAX_BLOCKS_IN_MCU
0082 #define D_MAX_BLOCKS_IN_MCU   10 /* decompressor's limit on data units/MCU */
0083 #endif
0084 
0085 
0086 /* Data structures for images (arrays of samples and of DCT coefficients).
0087  */
0088 
0089 typedef JSAMPLE *JSAMPROW;      /* ptr to one image row of pixel samples with
0090                                    2-bit through 8-bit data precision. */
0091 typedef JSAMPROW *JSAMPARRAY;   /* ptr to some JSAMPLE rows (a 2-D JSAMPLE
0092                                    array) */
0093 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D JSAMPLE array: top index is color */
0094 
0095 typedef J12SAMPLE *J12SAMPROW;      /* ptr to one image row of pixel samples
0096                                        with 9-bit through 12-bit data
0097                                        precision. */
0098 typedef J12SAMPROW *J12SAMPARRAY;   /* ptr to some J12SAMPLE rows (a 2-D
0099                                        J12SAMPLE array) */
0100 typedef J12SAMPARRAY *J12SAMPIMAGE; /* a 3-D J12SAMPLE array: top index is
0101                                        color */
0102 
0103 typedef J16SAMPLE *J16SAMPROW;      /* ptr to one image row of pixel samples
0104                                        with 13-bit through 16-bit data
0105                                        precision. */
0106 typedef J16SAMPROW *J16SAMPARRAY;   /* ptr to some J16SAMPLE rows (a 2-D
0107                                        J16SAMPLE array) */
0108 typedef J16SAMPARRAY *J16SAMPIMAGE; /* a 3-D J16SAMPLE array: top index is
0109                                        color */
0110 
0111 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
0112 typedef JBLOCK *JBLOCKROW;      /* pointer to one row of coefficient blocks */
0113 typedef JBLOCKROW *JBLOCKARRAY;         /* a 2-D array of coefficient blocks */
0114 typedef JBLOCKARRAY *JBLOCKIMAGE;       /* a 3-D array of coefficient blocks */
0115 
0116 typedef JCOEF *JCOEFPTR;        /* useful in a couple of places */
0117 
0118 
0119 /* Types for JPEG compression parameters and working tables. */
0120 
0121 
0122 /* DCT coefficient quantization tables. */
0123 
0124 typedef struct {
0125   /* This array gives the coefficient quantizers in natural array order
0126    * (not the zigzag order in which they are stored in a JPEG DQT marker).
0127    * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
0128    */
0129   UINT16 quantval[DCTSIZE2];    /* quantization step for each coefficient */
0130   /* This field is used only during compression.  It's initialized FALSE when
0131    * the table is created, and set TRUE when it's been output to the file.
0132    * You could suppress output of a table by setting this to TRUE.
0133    * (See jpeg_suppress_tables for an example.)
0134    */
0135   boolean sent_table;           /* TRUE when table has been output */
0136 } JQUANT_TBL;
0137 
0138 
0139 /* Huffman coding tables. */
0140 
0141 typedef struct {
0142   /* These two fields directly represent the contents of a JPEG DHT marker */
0143   UINT8 bits[17];               /* bits[k] = # of symbols with codes of */
0144                                 /* length k bits; bits[0] is unused */
0145   UINT8 huffval[256];           /* The symbols, in order of incr code length */
0146   /* This field is used only during compression.  It's initialized FALSE when
0147    * the table is created, and set TRUE when it's been output to the file.
0148    * You could suppress output of a table by setting this to TRUE.
0149    * (See jpeg_suppress_tables for an example.)
0150    */
0151   boolean sent_table;           /* TRUE when table has been output */
0152 } JHUFF_TBL;
0153 
0154 
0155 /* Basic info about one component (color channel). */
0156 
0157 typedef struct {
0158   /* These values are fixed over the whole image. */
0159   /* For compression, they must be supplied by parameter setup; */
0160   /* for decompression, they are read from the SOF marker. */
0161   int component_id;             /* identifier for this component (0..255) */
0162   int component_index;          /* its index in SOF or cinfo->comp_info[] */
0163   int h_samp_factor;            /* horizontal sampling factor (1..4) */
0164   int v_samp_factor;            /* vertical sampling factor (1..4) */
0165   int quant_tbl_no;             /* quantization table selector (0..3) */
0166   /* These values may vary between scans. */
0167   /* For compression, they must be supplied by parameter setup; */
0168   /* for decompression, they are read from the SOS marker. */
0169   /* The decompressor output side may not use these variables. */
0170   int dc_tbl_no;                /* DC entropy table selector (0..3) */
0171   int ac_tbl_no;                /* AC entropy table selector (0..3) */
0172 
0173   /* Remaining fields should be treated as private by applications. */
0174 
0175   /* These values are computed during compression or decompression startup: */
0176   /* Component's size in data units.
0177    * In lossy mode, any dummy blocks added to complete an MCU are not counted;
0178    * therefore these values do not depend on whether a scan is interleaved or
0179    * not.  In lossless mode, these are always equal to the image width and
0180    * height.
0181    */
0182   JDIMENSION width_in_blocks;
0183   JDIMENSION height_in_blocks;
0184   /* Size of a data unit in samples.  Always DCTSIZE for lossy compression.
0185    * For lossy decompression this is the size of the output from one DCT block,
0186    * reflecting any scaling we choose to apply during the IDCT step.
0187    * Values from 1 to 16 are supported.  Note that different components may
0188    * receive different IDCT scalings.  In lossless mode, this is always equal
0189    * to 1.
0190    */
0191 #if JPEG_LIB_VERSION >= 70
0192   int DCT_h_scaled_size;
0193   int DCT_v_scaled_size;
0194 #else
0195   int DCT_scaled_size;
0196 #endif
0197   /* The downsampled dimensions are the component's actual, unpadded number
0198    * of samples at the main buffer (preprocessing/compression interface), thus
0199    * downsampled_width = ceil(image_width * Hi/Hmax)
0200    * and similarly for height.  For lossy decompression, IDCT scaling is
0201    * included, so
0202    * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]scaled_size/DCTSIZE)
0203    * In lossless mode, these are always equal to the image width and height.
0204    */
0205   JDIMENSION downsampled_width;  /* actual width in samples */
0206   JDIMENSION downsampled_height; /* actual height in samples */
0207   /* This flag is used only for decompression.  In cases where some of the
0208    * components will be ignored (eg grayscale output from YCbCr image),
0209    * we can skip most computations for the unused components.
0210    */
0211   boolean component_needed;     /* do we need the value of this component? */
0212 
0213   /* These values are computed before starting a scan of the component. */
0214   /* The decompressor output side may not use these variables. */
0215   int MCU_width;                /* number of data units per MCU, horizontally */
0216   int MCU_height;               /* number of data units per MCU, vertically */
0217   int MCU_blocks;               /* MCU_width * MCU_height */
0218   int MCU_sample_width;         /* MCU width in samples, MCU_width*DCT_[h_]scaled_size */
0219   int last_col_width;           /* # of non-dummy data units across in last MCU */
0220   int last_row_height;          /* # of non-dummy data units down in last MCU */
0221 
0222   /* Saved quantization table for component; NULL if none yet saved.
0223    * See jdinput.c comments about the need for this information.
0224    * This field is currently used only for decompression.
0225    */
0226   JQUANT_TBL *quant_table;
0227 
0228   /* Private per-component storage for DCT or IDCT subsystem. */
0229   void *dct_table;
0230 } jpeg_component_info;
0231 
0232 
0233 /* The script for encoding a multiple-scan file is an array of these: */
0234 
0235 typedef struct {
0236   int comps_in_scan;            /* number of components encoded in this scan */
0237   int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
0238   int Ss, Se;                   /* progressive JPEG spectral selection parms
0239                                    (Ss is the predictor selection value in
0240                                    lossless mode) */
0241   int Ah, Al;                   /* progressive JPEG successive approx. parms
0242                                    (Al is the point transform value in lossless
0243                                    mode) */
0244 } jpeg_scan_info;
0245 
0246 /* The decompressor can save APPn and COM markers in a list of these: */
0247 
0248 typedef struct jpeg_marker_struct *jpeg_saved_marker_ptr;
0249 
0250 struct jpeg_marker_struct {
0251   jpeg_saved_marker_ptr next;   /* next in list, or NULL */
0252   UINT8 marker;                 /* marker code: JPEG_COM, or JPEG_APP0+n */
0253   unsigned int original_length; /* # bytes of data in the file */
0254   unsigned int data_length;     /* # bytes of data saved at data[] */
0255   JOCTET *data;                 /* the data contained in the marker */
0256   /* the marker length word is not counted in data_length or original_length */
0257 };
0258 
0259 /* Known color spaces. */
0260 
0261 #define JCS_EXTENSIONS  1
0262 #define JCS_ALPHA_EXTENSIONS  1
0263 
0264 typedef enum {
0265   JCS_UNKNOWN,            /* error/unspecified */
0266   JCS_GRAYSCALE,          /* monochrome */
0267   JCS_RGB,                /* red/green/blue as specified by the RGB_RED,
0268                              RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros */
0269   JCS_YCbCr,              /* Y/Cb/Cr (also known as YUV) */
0270   JCS_CMYK,               /* C/M/Y/K */
0271   JCS_YCCK,               /* Y/Cb/Cr/K */
0272   JCS_EXT_RGB,            /* red/green/blue */
0273   JCS_EXT_RGBX,           /* red/green/blue/x */
0274   JCS_EXT_BGR,            /* blue/green/red */
0275   JCS_EXT_BGRX,           /* blue/green/red/x */
0276   JCS_EXT_XBGR,           /* x/blue/green/red */
0277   JCS_EXT_XRGB,           /* x/red/green/blue */
0278   /* When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX, JCS_EXT_XBGR,
0279      or JCS_EXT_XRGB during decompression, the X byte is undefined, and in
0280      order to ensure the best performance, libjpeg-turbo can set that byte to
0281      whatever value it wishes.  Use the following colorspace constants to
0282      ensure that the X byte is set to 0xFF, so that it can be interpreted as an
0283      opaque alpha channel. */
0284   JCS_EXT_RGBA,           /* red/green/blue/alpha */
0285   JCS_EXT_BGRA,           /* blue/green/red/alpha */
0286   JCS_EXT_ABGR,           /* alpha/blue/green/red */
0287   JCS_EXT_ARGB,           /* alpha/red/green/blue */
0288   JCS_RGB565              /* 5-bit red/6-bit green/5-bit blue
0289                              [decompression only] */
0290 } J_COLOR_SPACE;
0291 
0292 /* DCT/IDCT algorithm options. */
0293 
0294 typedef enum {
0295   JDCT_ISLOW,             /* accurate integer method */
0296   JDCT_IFAST,             /* less accurate integer method [legacy feature] */
0297   JDCT_FLOAT              /* floating-point method [legacy feature] */
0298 } J_DCT_METHOD;
0299 
0300 #ifndef JDCT_DEFAULT            /* may be overridden in jconfig.h */
0301 #define JDCT_DEFAULT  JDCT_ISLOW
0302 #endif
0303 #ifndef JDCT_FASTEST            /* may be overridden in jconfig.h */
0304 #define JDCT_FASTEST  JDCT_IFAST
0305 #endif
0306 
0307 /* Dithering options for decompression. */
0308 
0309 typedef enum {
0310   JDITHER_NONE,           /* no dithering */
0311   JDITHER_ORDERED,        /* simple ordered dither */
0312   JDITHER_FS              /* Floyd-Steinberg error diffusion dither */
0313 } J_DITHER_MODE;
0314 
0315 
0316 /* Common fields between JPEG compression and decompression master structs. */
0317 
0318 #define jpeg_common_fields \
0319   struct jpeg_error_mgr *err;   /* Error handler module */ \
0320   struct jpeg_memory_mgr *mem;  /* Memory manager module */ \
0321   struct jpeg_progress_mgr *progress; /* Progress monitor, or NULL if none */ \
0322   void *client_data;            /* Available for use by application */ \
0323   boolean is_decompressor;      /* So common code can tell which is which */ \
0324   int global_state              /* For checking call sequence validity */
0325 
0326 /* Routines that are to be used by both halves of the library are declared
0327  * to receive a pointer to this structure.  There are no actual instances of
0328  * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
0329  */
0330 struct jpeg_common_struct {
0331   jpeg_common_fields;           /* Fields common to both master struct types */
0332   /* Additional fields follow in an actual jpeg_compress_struct or
0333    * jpeg_decompress_struct.  All three structs must agree on these
0334    * initial fields!  (This would be a lot cleaner in C++.)
0335    */
0336 };
0337 
0338 typedef struct jpeg_common_struct *j_common_ptr;
0339 typedef struct jpeg_compress_struct *j_compress_ptr;
0340 typedef struct jpeg_decompress_struct *j_decompress_ptr;
0341 
0342 
0343 /* Master record for a compression instance */
0344 
0345 struct jpeg_compress_struct {
0346   jpeg_common_fields;           /* Fields shared with jpeg_decompress_struct */
0347 
0348   /* Destination for compressed data */
0349   struct jpeg_destination_mgr *dest;
0350 
0351   /* Description of source image --- these fields must be filled in by
0352    * outer application before starting compression.  in_color_space must
0353    * be correct before you can even call jpeg_set_defaults().
0354    */
0355 
0356   JDIMENSION image_width;       /* input image width */
0357   JDIMENSION image_height;      /* input image height */
0358   int input_components;         /* # of color components in input image */
0359   J_COLOR_SPACE in_color_space; /* colorspace of input image */
0360 
0361   double input_gamma;           /* image gamma of input image */
0362 
0363   /* Compression parameters --- these fields must be set before calling
0364    * jpeg_start_compress().  We recommend calling jpeg_set_defaults() to
0365    * initialize everything to reasonable defaults, then changing anything
0366    * the application specifically wants to change.  That way you won't get
0367    * burnt when new parameters are added.  Also note that there are several
0368    * helper routines to simplify changing parameters.
0369    */
0370 
0371 #if JPEG_LIB_VERSION >= 70
0372   unsigned int scale_num, scale_denom; /* fraction by which to scale image */
0373 
0374   JDIMENSION jpeg_width;        /* scaled JPEG image width */
0375   JDIMENSION jpeg_height;       /* scaled JPEG image height */
0376   /* Dimensions of actual JPEG image that will be written to file,
0377    * derived from input dimensions by scaling factors above.
0378    * These fields are computed by jpeg_start_compress().
0379    * You can also use jpeg_calc_jpeg_dimensions() to determine these values
0380    * in advance of calling jpeg_start_compress().
0381    */
0382 #endif
0383 
0384   int data_precision;           /* bits of precision in image data */
0385 
0386   int num_components;           /* # of color components in JPEG image */
0387   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
0388 
0389   jpeg_component_info *comp_info;
0390   /* comp_info[i] describes component that appears i'th in SOF */
0391 
0392   JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
0393 #if JPEG_LIB_VERSION >= 70
0394   int q_scale_factor[NUM_QUANT_TBLS];
0395 #endif
0396   /* ptrs to coefficient quantization tables, or NULL if not defined,
0397    * and corresponding scale factors (percentage, initialized 100).
0398    */
0399 
0400   JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
0401   JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
0402   /* ptrs to Huffman coding tables, or NULL if not defined */
0403 
0404   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
0405   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
0406   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
0407 
0408   int num_scans;                /* # of entries in scan_info array */
0409   const jpeg_scan_info *scan_info; /* script for multi-scan file, or NULL */
0410   /* The default value of scan_info is NULL, which causes a single-scan
0411    * sequential JPEG file to be emitted.  To create a multi-scan file,
0412    * set num_scans and scan_info to point to an array of scan definitions.
0413    */
0414 
0415   boolean raw_data_in;          /* TRUE=caller supplies downsampled data */
0416   boolean arith_code;           /* TRUE=arithmetic coding, FALSE=Huffman */
0417   boolean optimize_coding;      /* TRUE=optimize entropy encoding parms */
0418   boolean CCIR601_sampling;     /* TRUE=first samples are cosited */
0419 #if JPEG_LIB_VERSION >= 70
0420   boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
0421 #endif
0422   int smoothing_factor;         /* 1..100, or 0 for no input smoothing */
0423   J_DCT_METHOD dct_method;      /* DCT algorithm selector */
0424 
0425   /* The restart interval can be specified in absolute MCUs by setting
0426    * restart_interval, or in MCU rows by setting restart_in_rows
0427    * (in which case the correct restart_interval will be figured
0428    * for each scan).
0429    */
0430   unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
0431   int restart_in_rows;          /* if > 0, MCU rows per restart interval */
0432 
0433   /* Parameters controlling emission of special markers. */
0434 
0435   boolean write_JFIF_header;    /* should a JFIF marker be written? */
0436   UINT8 JFIF_major_version;     /* What to write for the JFIF version number */
0437   UINT8 JFIF_minor_version;
0438   /* These three values are not used by the JPEG code, merely copied */
0439   /* into the JFIF APP0 marker.  density_unit can be 0 for unknown, */
0440   /* 1 for dots/inch, or 2 for dots/cm.  Note that the pixel aspect */
0441   /* ratio is defined by X_density/Y_density even when density_unit=0. */
0442   UINT8 density_unit;           /* JFIF code for pixel size units */
0443   UINT16 X_density;             /* Horizontal pixel density */
0444   UINT16 Y_density;             /* Vertical pixel density */
0445   boolean write_Adobe_marker;   /* should an Adobe marker be written? */
0446 
0447   /* State variable: index of next scanline to be written to
0448    * jpeg_write_scanlines().  Application may use this to control its
0449    * processing loop, e.g., "while (next_scanline < image_height)".
0450    */
0451 
0452   JDIMENSION next_scanline;     /* 0 .. image_height-1  */
0453 
0454   /* Remaining fields are known throughout compressor, but generally
0455    * should not be touched by a surrounding application.
0456    */
0457 
0458   /*
0459    * These fields are computed during compression startup
0460    */
0461   boolean progressive_mode;     /* TRUE if scan script uses progressive mode */
0462   int max_h_samp_factor;        /* largest h_samp_factor */
0463   int max_v_samp_factor;        /* largest v_samp_factor */
0464 
0465 #if JPEG_LIB_VERSION >= 70
0466   int min_DCT_h_scaled_size;    /* smallest DCT_h_scaled_size of any component */
0467   int min_DCT_v_scaled_size;    /* smallest DCT_v_scaled_size of any component */
0468 #endif
0469 
0470   JDIMENSION total_iMCU_rows;   /* # of iMCU rows to be input to coefficient or
0471                                    difference controller */
0472   /* The coefficient or difference controller receives data in units of MCU
0473    * rows as defined for fully interleaved scans (whether the JPEG file is
0474    * interleaved or not).  In lossy mode, there are v_samp_factor * DCTSIZE
0475    * sample rows of each component in an "iMCU" (interleaved MCU) row.  In
0476    * lossless mode, total_iMCU_rows is always equal to the image height.
0477    */
0478 
0479   /*
0480    * These fields are valid during any one scan.
0481    * They describe the components and MCUs actually appearing in the scan.
0482    */
0483   int comps_in_scan;            /* # of JPEG components in this scan */
0484   jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
0485   /* *cur_comp_info[i] describes component that appears i'th in SOS */
0486 
0487   JDIMENSION MCUs_per_row;      /* # of MCUs across the image */
0488   JDIMENSION MCU_rows_in_scan;  /* # of MCU rows in the image */
0489 
0490   int blocks_in_MCU;            /* # of data units per MCU */
0491   int MCU_membership[C_MAX_BLOCKS_IN_MCU];
0492   /* MCU_membership[i] is index in cur_comp_info of component owning */
0493   /* i'th data unit in an MCU */
0494 
0495   int Ss, Se, Ah, Al;           /* progressive/lossless JPEG parameters for
0496                                    scan */
0497 
0498 #if JPEG_LIB_VERSION >= 80
0499   int block_size;               /* the basic DCT block size: 1..16 */
0500   const int *natural_order;     /* natural-order position array */
0501   int lim_Se;                   /* min( Se, DCTSIZE2-1 ) */
0502 #endif
0503 
0504   /*
0505    * Links to compression subobjects (methods and private variables of modules)
0506    */
0507   struct jpeg_comp_master *master;
0508   struct jpeg_c_main_controller *main;
0509   struct jpeg_c_prep_controller *prep;
0510   struct jpeg_c_coef_controller *coef;
0511   struct jpeg_marker_writer *marker;
0512   struct jpeg_color_converter *cconvert;
0513   struct jpeg_downsampler *downsample;
0514   struct jpeg_forward_dct *fdct;
0515   struct jpeg_entropy_encoder *entropy;
0516   jpeg_scan_info *script_space; /* workspace for jpeg_simple_progression */
0517   int script_space_size;
0518 };
0519 
0520 
0521 /* Master record for a decompression instance */
0522 
0523 struct jpeg_decompress_struct {
0524   jpeg_common_fields;           /* Fields shared with jpeg_compress_struct */
0525 
0526   /* Source of compressed data */
0527   struct jpeg_source_mgr *src;
0528 
0529   /* Basic description of image --- filled in by jpeg_read_header(). */
0530   /* Application may inspect these values to decide how to process image. */
0531 
0532   JDIMENSION image_width;       /* nominal image width (from SOF marker) */
0533   JDIMENSION image_height;      /* nominal image height */
0534   int num_components;           /* # of color components in JPEG image */
0535   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
0536 
0537   /* Decompression processing parameters --- these fields must be set before
0538    * calling jpeg_start_decompress().  Note that jpeg_read_header() initializes
0539    * them to default values.
0540    */
0541 
0542   J_COLOR_SPACE out_color_space; /* colorspace for output */
0543 
0544   unsigned int scale_num, scale_denom; /* fraction by which to scale image */
0545 
0546   double output_gamma;          /* image gamma wanted in output */
0547 
0548   boolean buffered_image;       /* TRUE=multiple output passes */
0549   boolean raw_data_out;         /* TRUE=downsampled data wanted */
0550 
0551   J_DCT_METHOD dct_method;      /* IDCT algorithm selector */
0552   boolean do_fancy_upsampling;  /* TRUE=apply fancy upsampling */
0553   boolean do_block_smoothing;   /* TRUE=apply interblock smoothing */
0554 
0555   boolean quantize_colors;      /* TRUE=colormapped output wanted */
0556   /* the following are ignored if not quantize_colors: */
0557   J_DITHER_MODE dither_mode;    /* type of color dithering to use */
0558   boolean two_pass_quantize;    /* TRUE=use two-pass color quantization */
0559   int desired_number_of_colors; /* max # colors to use in created colormap */
0560   /* these are significant only in buffered-image mode: */
0561   boolean enable_1pass_quant;   /* enable future use of 1-pass quantizer */
0562   boolean enable_external_quant;/* enable future use of external colormap */
0563   boolean enable_2pass_quant;   /* enable future use of 2-pass quantizer */
0564 
0565   /* Description of actual output image that will be returned to application.
0566    * These fields are computed by jpeg_start_decompress().
0567    * You can also use jpeg_calc_output_dimensions() to determine these values
0568    * in advance of calling jpeg_start_decompress().
0569    */
0570 
0571   JDIMENSION output_width;      /* scaled image width */
0572   JDIMENSION output_height;     /* scaled image height */
0573   int out_color_components;     /* # of color components in out_color_space */
0574   int output_components;        /* # of color components returned */
0575   /* output_components is 1 (a colormap index) when quantizing colors;
0576    * otherwise it equals out_color_components.
0577    */
0578   int rec_outbuf_height;        /* min recommended height of scanline buffer */
0579   /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
0580    * high, space and time will be wasted due to unnecessary data copying.
0581    * Usually rec_outbuf_height will be 1 or 2, at most 4.
0582    */
0583 
0584   /* When quantizing colors, the output colormap is described by these fields.
0585    * The application can supply a colormap by setting colormap non-NULL before
0586    * calling jpeg_start_decompress; otherwise a colormap is created during
0587    * jpeg_start_decompress or jpeg_start_output.
0588    * The map has out_color_components rows and actual_number_of_colors columns.
0589    */
0590   int actual_number_of_colors;  /* number of entries in use */
0591   JSAMPARRAY colormap;          /* The color map as a 2-D pixel array
0592                                    If data_precision is 12, then this is
0593                                    actually a J12SAMPARRAY, so callers must
0594                                    type-cast it in order to read/write 12-bit
0595                                    samples from/to the array. */
0596 
0597   /* State variables: these variables indicate the progress of decompression.
0598    * The application may examine these but must not modify them.
0599    */
0600 
0601   /* Row index of next scanline to be read from jpeg_read_scanlines().
0602    * Application may use this to control its processing loop, e.g.,
0603    * "while (output_scanline < output_height)".
0604    */
0605   JDIMENSION output_scanline;   /* 0 .. output_height-1  */
0606 
0607   /* Current input scan number and number of iMCU rows completed in scan.
0608    * These indicate the progress of the decompressor input side.
0609    */
0610   int input_scan_number;        /* Number of SOS markers seen so far */
0611   JDIMENSION input_iMCU_row;    /* Number of iMCU rows completed */
0612 
0613   /* The "output scan number" is the notional scan being displayed by the
0614    * output side.  The decompressor will not allow output scan/row number
0615    * to get ahead of input scan/row, but it can fall arbitrarily far behind.
0616    */
0617   int output_scan_number;       /* Nominal scan number being displayed */
0618   JDIMENSION output_iMCU_row;   /* Number of iMCU rows read */
0619 
0620   /* Current progression status.  coef_bits[c][i] indicates the precision
0621    * with which component c's DCT coefficient i (in zigzag order) is known.
0622    * It is -1 when no data has yet been received, otherwise it is the point
0623    * transform (shift) value for the most recent scan of the coefficient
0624    * (thus, 0 at completion of the progression).
0625    * This pointer is NULL when reading a non-progressive file.
0626    */
0627   int (*coef_bits)[DCTSIZE2];   /* -1 or current Al value for each coef */
0628 
0629   /* Internal JPEG parameters --- the application usually need not look at
0630    * these fields.  Note that the decompressor output side may not use
0631    * any parameters that can change between scans.
0632    */
0633 
0634   /* Quantization and Huffman tables are carried forward across input
0635    * datastreams when processing abbreviated JPEG datastreams.
0636    */
0637 
0638   JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
0639   /* ptrs to coefficient quantization tables, or NULL if not defined */
0640 
0641   JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
0642   JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
0643   /* ptrs to Huffman coding tables, or NULL if not defined */
0644 
0645   /* These parameters are never carried across datastreams, since they
0646    * are given in SOF/SOS markers or defined to be reset by SOI.
0647    */
0648 
0649   int data_precision;           /* bits of precision in image data */
0650 
0651   jpeg_component_info *comp_info;
0652   /* comp_info[i] describes component that appears i'th in SOF */
0653 
0654 #if JPEG_LIB_VERSION >= 80
0655   boolean is_baseline;          /* TRUE if Baseline SOF0 encountered */
0656 #endif
0657   boolean progressive_mode;     /* TRUE if SOFn specifies progressive mode */
0658   boolean arith_code;           /* TRUE=arithmetic coding, FALSE=Huffman */
0659 
0660   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
0661   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
0662   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
0663 
0664   unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
0665 
0666   /* These fields record data obtained from optional markers recognized by
0667    * the JPEG library.
0668    */
0669   boolean saw_JFIF_marker;      /* TRUE iff a JFIF APP0 marker was found */
0670   /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
0671   UINT8 JFIF_major_version;     /* JFIF version number */
0672   UINT8 JFIF_minor_version;
0673   UINT8 density_unit;           /* JFIF code for pixel size units */
0674   UINT16 X_density;             /* Horizontal pixel density */
0675   UINT16 Y_density;             /* Vertical pixel density */
0676   boolean saw_Adobe_marker;     /* TRUE iff an Adobe APP14 marker was found */
0677   UINT8 Adobe_transform;        /* Color transform code from Adobe marker */
0678 
0679   boolean CCIR601_sampling;     /* TRUE=first samples are cosited */
0680 
0681   /* Aside from the specific data retained from APPn markers known to the
0682    * library, the uninterpreted contents of any or all APPn and COM markers
0683    * can be saved in a list for examination by the application.
0684    */
0685   jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
0686 
0687   /* Remaining fields are known throughout decompressor, but generally
0688    * should not be touched by a surrounding application.
0689    */
0690 
0691   /*
0692    * These fields are computed during decompression startup
0693    */
0694   int max_h_samp_factor;        /* largest h_samp_factor */
0695   int max_v_samp_factor;        /* largest v_samp_factor */
0696 
0697 #if JPEG_LIB_VERSION >= 70
0698   int min_DCT_h_scaled_size;    /* smallest DCT_h_scaled_size of any component */
0699   int min_DCT_v_scaled_size;    /* smallest DCT_v_scaled_size of any component */
0700 #else
0701   int min_DCT_scaled_size;      /* smallest DCT_scaled_size of any component */
0702 #endif
0703 
0704   JDIMENSION total_iMCU_rows;   /* # of iMCU rows in image */
0705   /* The coefficient or difference controller's input and output progress is
0706    * measured in units of "iMCU" (interleaved MCU) rows.  These are the same as
0707    * MCU rows in fully interleaved JPEG scans, but are used whether the scan is
0708    * interleaved or not.  In lossy mode, we define an iMCU row as v_samp_factor
0709    * DCT block rows of each component.  Therefore, the IDCT output contains
0710    * v_samp_factor*DCT_[v_]scaled_size sample rows of a component per iMCU row.
0711    * In lossless mode, total_iMCU_rows is always equal to the image height.
0712    */
0713 
0714   JSAMPLE *sample_range_limit;  /* table for fast range-limiting
0715                                    If data_precision is 9 to 12, then this is
0716                                    actually a J12SAMPLE pointer, and if
0717                                    data_precision is 13 to 16, then this is
0718                                    actually a J16SAMPLE pointer, so callers
0719                                    must type-cast it in order to read samples
0720                                    from the array. */
0721 
0722   /*
0723    * These fields are valid during any one scan.
0724    * They describe the components and MCUs actually appearing in the scan.
0725    * Note that the decompressor output side must not use these fields.
0726    */
0727   int comps_in_scan;            /* # of JPEG components in this scan */
0728   jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
0729   /* *cur_comp_info[i] describes component that appears i'th in SOS */
0730 
0731   JDIMENSION MCUs_per_row;      /* # of MCUs across the image */
0732   JDIMENSION MCU_rows_in_scan;  /* # of MCU rows in the image */
0733 
0734   int blocks_in_MCU;            /* # of data units per MCU */
0735   int MCU_membership[D_MAX_BLOCKS_IN_MCU];
0736   /* MCU_membership[i] is index in cur_comp_info of component owning */
0737   /* i'th data unit in an MCU */
0738 
0739   int Ss, Se, Ah, Al;           /* progressive/lossless JPEG parameters for
0740                                    scan */
0741 
0742 #if JPEG_LIB_VERSION >= 80
0743   /* These fields are derived from Se of first SOS marker.
0744    */
0745   int block_size;               /* the basic DCT block size: 1..16 */
0746   const int *natural_order; /* natural-order position array for entropy decode */
0747   int lim_Se;                   /* min( Se, DCTSIZE2-1 ) for entropy decode */
0748 #endif
0749 
0750   /* This field is shared between entropy decoder and marker parser.
0751    * It is either zero or the code of a JPEG marker that has been
0752    * read from the data source, but has not yet been processed.
0753    */
0754   int unread_marker;
0755 
0756   /*
0757    * Links to decompression subobjects (methods, private variables of modules)
0758    */
0759   struct jpeg_decomp_master *master;
0760   struct jpeg_d_main_controller *main;
0761   struct jpeg_d_coef_controller *coef;
0762   struct jpeg_d_post_controller *post;
0763   struct jpeg_input_controller *inputctl;
0764   struct jpeg_marker_reader *marker;
0765   struct jpeg_entropy_decoder *entropy;
0766   struct jpeg_inverse_dct *idct;
0767   struct jpeg_upsampler *upsample;
0768   struct jpeg_color_deconverter *cconvert;
0769   struct jpeg_color_quantizer *cquantize;
0770 };
0771 
0772 
0773 /* "Object" declarations for JPEG modules that may be supplied or called
0774  * directly by the surrounding application.
0775  * As with all objects in the JPEG library, these structs only define the
0776  * publicly visible methods and state variables of a module.  Additional
0777  * private fields may exist after the public ones.
0778  */
0779 
0780 
0781 /* Error handler object */
0782 
0783 struct jpeg_error_mgr {
0784   /* Error exit handler: does not return to caller */
0785   void (*error_exit) (j_common_ptr cinfo);
0786   /* Conditionally emit a trace or warning message */
0787   void (*emit_message) (j_common_ptr cinfo, int msg_level);
0788   /* Routine that actually outputs a trace or error message */
0789   void (*output_message) (j_common_ptr cinfo);
0790   /* Format a message string for the most recent JPEG error or message */
0791   void (*format_message) (j_common_ptr cinfo, char *buffer);
0792 #define JMSG_LENGTH_MAX  200    /* recommended size of format_message buffer */
0793   /* Reset error state variables at start of a new image */
0794   void (*reset_error_mgr) (j_common_ptr cinfo);
0795 
0796   /* The message ID code and any parameters are saved here.
0797    * A message can have one string parameter or up to 8 int parameters.
0798    */
0799   int msg_code;
0800 #define JMSG_STR_PARM_MAX  80
0801   union {
0802     int i[8];
0803     char s[JMSG_STR_PARM_MAX];
0804   } msg_parm;
0805 
0806   /* Standard state variables for error facility */
0807 
0808   int trace_level;              /* max msg_level that will be displayed */
0809 
0810   /* For recoverable corrupt-data errors, we emit a warning message,
0811    * but keep going unless emit_message chooses to abort.  emit_message
0812    * should count warnings in num_warnings.  The surrounding application
0813    * can check for bad data by seeing if num_warnings is nonzero at the
0814    * end of processing.
0815    */
0816   long num_warnings;            /* number of corrupt-data warnings */
0817 
0818   /* These fields point to the table(s) of error message strings.
0819    * An application can change the table pointer to switch to a different
0820    * message list (typically, to change the language in which errors are
0821    * reported).  Some applications may wish to add additional error codes
0822    * that will be handled by the JPEG library error mechanism; the second
0823    * table pointer is used for this purpose.
0824    *
0825    * First table includes all errors generated by JPEG library itself.
0826    * Error code 0 is reserved for a "no such error string" message.
0827    */
0828   const char * const *jpeg_message_table; /* Library errors */
0829   int last_jpeg_message;    /* Table contains strings 0..last_jpeg_message */
0830   /* Second table can be added by application (see cjpeg/djpeg for example).
0831    * It contains strings numbered first_addon_message..last_addon_message.
0832    */
0833   const char * const *addon_message_table; /* Non-library errors */
0834   int first_addon_message;      /* code for first string in addon table */
0835   int last_addon_message;       /* code for last string in addon table */
0836 };
0837 
0838 
0839 /* Progress monitor object */
0840 
0841 struct jpeg_progress_mgr {
0842   void (*progress_monitor) (j_common_ptr cinfo);
0843 
0844   long pass_counter;            /* work units completed in this pass */
0845   long pass_limit;              /* total number of work units in this pass */
0846   int completed_passes;         /* passes completed so far */
0847   int total_passes;             /* total number of passes expected */
0848 };
0849 
0850 
0851 /* Data destination object for compression */
0852 
0853 struct jpeg_destination_mgr {
0854   JOCTET *next_output_byte;     /* => next byte to write in buffer */
0855   size_t free_in_buffer;        /* # of byte spaces remaining in buffer */
0856 
0857   void (*init_destination) (j_compress_ptr cinfo);
0858   boolean (*empty_output_buffer) (j_compress_ptr cinfo);
0859   void (*term_destination) (j_compress_ptr cinfo);
0860 };
0861 
0862 
0863 /* Data source object for decompression */
0864 
0865 struct jpeg_source_mgr {
0866   const JOCTET *next_input_byte; /* => next byte to read from buffer */
0867   size_t bytes_in_buffer;       /* # of bytes remaining in buffer */
0868 
0869   void (*init_source) (j_decompress_ptr cinfo);
0870   boolean (*fill_input_buffer) (j_decompress_ptr cinfo);
0871   void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes);
0872   boolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired);
0873   void (*term_source) (j_decompress_ptr cinfo);
0874 };
0875 
0876 
0877 /* Memory manager object.
0878  * Allocates "small" objects (a few K total), "large" objects (tens of K),
0879  * and "really big" objects (virtual arrays with backing store if needed).
0880  * The memory manager does not allow individual objects to be freed; rather,
0881  * each created object is assigned to a pool, and whole pools can be freed
0882  * at once.  This is faster and more convenient than remembering exactly what
0883  * to free, especially where malloc()/free() are not too speedy.
0884  * NB: alloc routines never return NULL.  They exit to error_exit if not
0885  * successful.
0886  */
0887 
0888 #define JPOOL_PERMANENT  0      /* lasts until master record is destroyed */
0889 #define JPOOL_IMAGE      1      /* lasts until done with image/datastream */
0890 #define JPOOL_NUMPOOLS   2
0891 
0892 typedef struct jvirt_sarray_control *jvirt_sarray_ptr;
0893 typedef struct jvirt_barray_control *jvirt_barray_ptr;
0894 
0895 
0896 struct jpeg_memory_mgr {
0897   /* Method pointers */
0898   void *(*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject);
0899   void *(*alloc_large) (j_common_ptr cinfo, int pool_id,
0900                         size_t sizeofobject);
0901   /* If cinfo->data_precision is 12 or 16, then this method and the
0902    * access_virt_sarray method actually return a J12SAMPARRAY or a
0903    * J16SAMPARRAY, so callers must type-cast the return value in order to
0904    * read/write 12-bit or 16-bit samples from/to the array.
0905    */
0906   JSAMPARRAY (*alloc_sarray) (j_common_ptr cinfo, int pool_id,
0907                               JDIMENSION samplesperrow, JDIMENSION numrows);
0908   JBLOCKARRAY (*alloc_barray) (j_common_ptr cinfo, int pool_id,
0909                                JDIMENSION blocksperrow, JDIMENSION numrows);
0910   jvirt_sarray_ptr (*request_virt_sarray) (j_common_ptr cinfo, int pool_id,
0911                                            boolean pre_zero,
0912                                            JDIMENSION samplesperrow,
0913                                            JDIMENSION numrows,
0914                                            JDIMENSION maxaccess);
0915   jvirt_barray_ptr (*request_virt_barray) (j_common_ptr cinfo, int pool_id,
0916                                            boolean pre_zero,
0917                                            JDIMENSION blocksperrow,
0918                                            JDIMENSION numrows,
0919                                            JDIMENSION maxaccess);
0920   void (*realize_virt_arrays) (j_common_ptr cinfo);
0921   JSAMPARRAY (*access_virt_sarray) (j_common_ptr cinfo, jvirt_sarray_ptr ptr,
0922                                     JDIMENSION start_row, JDIMENSION num_rows,
0923                                     boolean writable);
0924   JBLOCKARRAY (*access_virt_barray) (j_common_ptr cinfo, jvirt_barray_ptr ptr,
0925                                      JDIMENSION start_row, JDIMENSION num_rows,
0926                                      boolean writable);
0927   void (*free_pool) (j_common_ptr cinfo, int pool_id);
0928   void (*self_destruct) (j_common_ptr cinfo);
0929 
0930   /* Limit on memory allocation for this JPEG object.  (Note that this is
0931    * merely advisory, not a guaranteed maximum; it only affects the space
0932    * used for virtual-array buffers.)  May be changed by outer application
0933    * after creating the JPEG object.
0934    */
0935   long max_memory_to_use;
0936 
0937   /* Maximum allocation request accepted by alloc_large. */
0938   long max_alloc_chunk;
0939 };
0940 
0941 
0942 /* Routine signature for application-supplied marker processing methods.
0943  * Need not pass marker code since it is stored in cinfo->unread_marker.
0944  */
0945 typedef boolean (*jpeg_marker_parser_method) (j_decompress_ptr cinfo);
0946 
0947 
0948 /* Originally, this macro was used as a way of defining function prototypes
0949  * for both modern compilers as well as older compilers that did not support
0950  * prototype parameters.  libjpeg-turbo has never supported these older,
0951  * non-ANSI compilers, but the macro is still included because there is some
0952  * software out there that uses it.
0953  */
0954 
0955 #define JPP(arglist)    arglist
0956 
0957 
0958 /* Default error-management setup */
0959 EXTERN(struct jpeg_error_mgr *) jpeg_std_error(struct jpeg_error_mgr *err);
0960 
0961 /* Initialization of JPEG compression objects.
0962  * jpeg_create_compress() and jpeg_create_decompress() are the exported
0963  * names that applications should call.  These expand to calls on
0964  * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
0965  * passed for version mismatch checking.
0966  * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
0967  */
0968 #define jpeg_create_compress(cinfo) \
0969   jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
0970                       (size_t)sizeof(struct jpeg_compress_struct))
0971 #define jpeg_create_decompress(cinfo) \
0972   jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
0973                         (size_t)sizeof(struct jpeg_decompress_struct))
0974 EXTERN(void) jpeg_CreateCompress(j_compress_ptr cinfo, int version,
0975                                  size_t structsize);
0976 EXTERN(void) jpeg_CreateDecompress(j_decompress_ptr cinfo, int version,
0977                                    size_t structsize);
0978 /* Destruction of JPEG compression objects */
0979 EXTERN(void) jpeg_destroy_compress(j_compress_ptr cinfo);
0980 EXTERN(void) jpeg_destroy_decompress(j_decompress_ptr cinfo);
0981 
0982 /* Standard data source and destination managers: stdio streams. */
0983 /* Caller is responsible for opening the file before and closing after. */
0984 EXTERN(void) jpeg_stdio_dest(j_compress_ptr cinfo, FILE *outfile);
0985 EXTERN(void) jpeg_stdio_src(j_decompress_ptr cinfo, FILE *infile);
0986 
0987 /* Data source and destination managers: memory buffers. */
0988 EXTERN(void) jpeg_mem_dest(j_compress_ptr cinfo, unsigned char **outbuffer,
0989                            unsigned long *outsize);
0990 EXTERN(void) jpeg_mem_src(j_decompress_ptr cinfo,
0991                           const unsigned char *inbuffer, unsigned long insize);
0992 
0993 /* Default parameter setup for compression */
0994 EXTERN(void) jpeg_set_defaults(j_compress_ptr cinfo);
0995 /* Compression parameter setup aids */
0996 EXTERN(void) jpeg_set_colorspace(j_compress_ptr cinfo,
0997                                  J_COLOR_SPACE colorspace);
0998 EXTERN(void) jpeg_default_colorspace(j_compress_ptr cinfo);
0999 EXTERN(void) jpeg_set_quality(j_compress_ptr cinfo, int quality,
1000                               boolean force_baseline);
1001 EXTERN(void) jpeg_set_linear_quality(j_compress_ptr cinfo, int scale_factor,
1002                                      boolean force_baseline);
1003 #if JPEG_LIB_VERSION >= 70
1004 EXTERN(void) jpeg_default_qtables(j_compress_ptr cinfo,
1005                                   boolean force_baseline);
1006 #endif
1007 EXTERN(void) jpeg_add_quant_table(j_compress_ptr cinfo, int which_tbl,
1008                                   const unsigned int *basic_table,
1009                                   int scale_factor, boolean force_baseline);
1010 EXTERN(int) jpeg_quality_scaling(int quality);
1011 EXTERN(void) jpeg_enable_lossless(j_compress_ptr cinfo,
1012                                   int predictor_selection_value,
1013                                   int point_transform);
1014 EXTERN(void) jpeg_simple_progression(j_compress_ptr cinfo);
1015 EXTERN(void) jpeg_suppress_tables(j_compress_ptr cinfo, boolean suppress);
1016 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table(j_common_ptr cinfo);
1017 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table(j_common_ptr cinfo);
1018 
1019 /* Main entry points for compression */
1020 EXTERN(void) jpeg_start_compress(j_compress_ptr cinfo,
1021                                  boolean write_all_tables);
1022 EXTERN(JDIMENSION) jpeg_write_scanlines(j_compress_ptr cinfo,
1023                                         JSAMPARRAY scanlines,
1024                                         JDIMENSION num_lines);
1025 EXTERN(JDIMENSION) jpeg12_write_scanlines(j_compress_ptr cinfo,
1026                                           J12SAMPARRAY scanlines,
1027                                           JDIMENSION num_lines);
1028 EXTERN(JDIMENSION) jpeg16_write_scanlines(j_compress_ptr cinfo,
1029                                           J16SAMPARRAY scanlines,
1030                                           JDIMENSION num_lines);
1031 EXTERN(void) jpeg_finish_compress(j_compress_ptr cinfo);
1032 
1033 #if JPEG_LIB_VERSION >= 70
1034 /* Precalculate JPEG dimensions for current compression parameters. */
1035 EXTERN(void) jpeg_calc_jpeg_dimensions(j_compress_ptr cinfo);
1036 #endif
1037 
1038 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
1039 EXTERN(JDIMENSION) jpeg_write_raw_data(j_compress_ptr cinfo, JSAMPIMAGE data,
1040                                        JDIMENSION num_lines);
1041 EXTERN(JDIMENSION) jpeg12_write_raw_data(j_compress_ptr cinfo,
1042                                          J12SAMPIMAGE data,
1043                                          JDIMENSION num_lines);
1044 
1045 /* Write a special marker.  See libjpeg.txt concerning safe usage. */
1046 EXTERN(void) jpeg_write_marker(j_compress_ptr cinfo, int marker,
1047                                const JOCTET *dataptr, unsigned int datalen);
1048 /* Same, but piecemeal. */
1049 EXTERN(void) jpeg_write_m_header(j_compress_ptr cinfo, int marker,
1050                                  unsigned int datalen);
1051 EXTERN(void) jpeg_write_m_byte(j_compress_ptr cinfo, int val);
1052 
1053 /* Alternate compression function: just write an abbreviated table file */
1054 EXTERN(void) jpeg_write_tables(j_compress_ptr cinfo);
1055 
1056 /* Write ICC profile.  See libjpeg.txt for usage information. */
1057 EXTERN(void) jpeg_write_icc_profile(j_compress_ptr cinfo,
1058                                     const JOCTET *icc_data_ptr,
1059                                     unsigned int icc_data_len);
1060 
1061 
1062 /* Decompression startup: read start of JPEG datastream to see what's there */
1063 EXTERN(int) jpeg_read_header(j_decompress_ptr cinfo, boolean require_image);
1064 /* Return value is one of: */
1065 #define JPEG_SUSPENDED           0 /* Suspended due to lack of input data */
1066 #define JPEG_HEADER_OK           1 /* Found valid image datastream */
1067 #define JPEG_HEADER_TABLES_ONLY  2 /* Found valid table-specs-only datastream */
1068 /* If you pass require_image = TRUE (normal case), you need not check for
1069  * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
1070  * JPEG_SUSPENDED is only possible if you use a data source module that can
1071  * give a suspension return (the stdio source module doesn't).
1072  */
1073 
1074 /* Main entry points for decompression */
1075 EXTERN(boolean) jpeg_start_decompress(j_decompress_ptr cinfo);
1076 EXTERN(JDIMENSION) jpeg_read_scanlines(j_decompress_ptr cinfo,
1077                                        JSAMPARRAY scanlines,
1078                                        JDIMENSION max_lines);
1079 EXTERN(JDIMENSION) jpeg12_read_scanlines(j_decompress_ptr cinfo,
1080                                          J12SAMPARRAY scanlines,
1081                                          JDIMENSION max_lines);
1082 EXTERN(JDIMENSION) jpeg16_read_scanlines(j_decompress_ptr cinfo,
1083                                          J16SAMPARRAY scanlines,
1084                                          JDIMENSION max_lines);
1085 EXTERN(JDIMENSION) jpeg_skip_scanlines(j_decompress_ptr cinfo,
1086                                        JDIMENSION num_lines);
1087 EXTERN(JDIMENSION) jpeg12_skip_scanlines(j_decompress_ptr cinfo,
1088                                          JDIMENSION num_lines);
1089 EXTERN(void) jpeg_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
1090                                 JDIMENSION *width);
1091 EXTERN(void) jpeg12_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
1092                                   JDIMENSION *width);
1093 EXTERN(boolean) jpeg_finish_decompress(j_decompress_ptr cinfo);
1094 
1095 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
1096 EXTERN(JDIMENSION) jpeg_read_raw_data(j_decompress_ptr cinfo, JSAMPIMAGE data,
1097                                       JDIMENSION max_lines);
1098 EXTERN(JDIMENSION) jpeg12_read_raw_data(j_decompress_ptr cinfo,
1099                                         J12SAMPIMAGE data,
1100                                         JDIMENSION max_lines);
1101 
1102 /* Additional entry points for buffered-image mode. */
1103 EXTERN(boolean) jpeg_has_multiple_scans(j_decompress_ptr cinfo);
1104 EXTERN(boolean) jpeg_start_output(j_decompress_ptr cinfo, int scan_number);
1105 EXTERN(boolean) jpeg_finish_output(j_decompress_ptr cinfo);
1106 EXTERN(boolean) jpeg_input_complete(j_decompress_ptr cinfo);
1107 EXTERN(void) jpeg_new_colormap(j_decompress_ptr cinfo);
1108 EXTERN(int) jpeg_consume_input(j_decompress_ptr cinfo);
1109 /* Return value is one of: */
1110 /* #define JPEG_SUSPENDED       0    Suspended due to lack of input data */
1111 #define JPEG_REACHED_SOS        1 /* Reached start of new scan */
1112 #define JPEG_REACHED_EOI        2 /* Reached end of image */
1113 #define JPEG_ROW_COMPLETED      3 /* Completed one iMCU row */
1114 #define JPEG_SCAN_COMPLETED     4 /* Completed last iMCU row of a scan */
1115 
1116 /* Precalculate output dimensions for current decompression parameters. */
1117 #if JPEG_LIB_VERSION >= 80
1118 EXTERN(void) jpeg_core_output_dimensions(j_decompress_ptr cinfo);
1119 #endif
1120 EXTERN(void) jpeg_calc_output_dimensions(j_decompress_ptr cinfo);
1121 
1122 /* Control saving of COM and APPn markers into marker_list. */
1123 EXTERN(void) jpeg_save_markers(j_decompress_ptr cinfo, int marker_code,
1124                                unsigned int length_limit);
1125 
1126 /* Install a special processing method for COM or APPn markers. */
1127 EXTERN(void) jpeg_set_marker_processor(j_decompress_ptr cinfo,
1128                                        int marker_code,
1129                                        jpeg_marker_parser_method routine);
1130 
1131 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
1132 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients(j_decompress_ptr cinfo);
1133 EXTERN(void) jpeg_write_coefficients(j_compress_ptr cinfo,
1134                                      jvirt_barray_ptr *coef_arrays);
1135 EXTERN(void) jpeg_copy_critical_parameters(j_decompress_ptr srcinfo,
1136                                            j_compress_ptr dstinfo);
1137 
1138 /* If you choose to abort compression or decompression before completing
1139  * jpeg_finish_(de)compress, then you need to clean up to release memory,
1140  * temporary files, etc.  You can just call jpeg_destroy_(de)compress
1141  * if you're done with the JPEG object, but if you want to clean it up and
1142  * reuse it, call this:
1143  */
1144 EXTERN(void) jpeg_abort_compress(j_compress_ptr cinfo);
1145 EXTERN(void) jpeg_abort_decompress(j_decompress_ptr cinfo);
1146 
1147 /* Generic versions of jpeg_abort and jpeg_destroy that work on either
1148  * flavor of JPEG object.  These may be more convenient in some places.
1149  */
1150 EXTERN(void) jpeg_abort(j_common_ptr cinfo);
1151 EXTERN(void) jpeg_destroy(j_common_ptr cinfo);
1152 
1153 /* Default restart-marker-resync procedure for use by data source modules */
1154 EXTERN(boolean) jpeg_resync_to_restart(j_decompress_ptr cinfo, int desired);
1155 
1156 /* Read ICC profile.  See libjpeg.txt for usage information. */
1157 EXTERN(boolean) jpeg_read_icc_profile(j_decompress_ptr cinfo,
1158                                       JOCTET **icc_data_ptr,
1159                                       unsigned int *icc_data_len);
1160 
1161 
1162 /* These marker codes are exported since applications and data source modules
1163  * are likely to want to use them.
1164  */
1165 
1166 #define JPEG_RST0       0xD0    /* RST0 marker code */
1167 #define JPEG_EOI        0xD9    /* EOI marker code */
1168 #define JPEG_APP0       0xE0    /* APP0 marker code */
1169 #define JPEG_COM        0xFE    /* COM marker code */
1170 
1171 
1172 /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
1173  * for structure definitions that are never filled in, keep it quiet by
1174  * supplying dummy definitions for the various substructures.
1175  */
1176 
1177 #ifdef INCOMPLETE_TYPES_BROKEN
1178 #ifndef JPEG_INTERNALS          /* will be defined in jpegint.h */
1179 struct jvirt_sarray_control { long dummy; };
1180 struct jvirt_barray_control { long dummy; };
1181 struct jpeg_comp_master { long dummy; };
1182 struct jpeg_c_main_controller { long dummy; };
1183 struct jpeg_c_prep_controller { long dummy; };
1184 struct jpeg_c_coef_controller { long dummy; };
1185 struct jpeg_marker_writer { long dummy; };
1186 struct jpeg_color_converter { long dummy; };
1187 struct jpeg_downsampler { long dummy; };
1188 struct jpeg_forward_dct { long dummy; };
1189 struct jpeg_entropy_encoder { long dummy; };
1190 struct jpeg_decomp_master { long dummy; };
1191 struct jpeg_d_main_controller { long dummy; };
1192 struct jpeg_d_coef_controller { long dummy; };
1193 struct jpeg_d_post_controller { long dummy; };
1194 struct jpeg_input_controller { long dummy; };
1195 struct jpeg_marker_reader { long dummy; };
1196 struct jpeg_entropy_decoder { long dummy; };
1197 struct jpeg_inverse_dct { long dummy; };
1198 struct jpeg_upsampler { long dummy; };
1199 struct jpeg_color_deconverter { long dummy; };
1200 struct jpeg_color_quantizer { long dummy; };
1201 #endif /* JPEG_INTERNALS */
1202 #endif /* INCOMPLETE_TYPES_BROKEN */
1203 
1204 
1205 /*
1206  * The JPEG library modules define JPEG_INTERNALS before including this file.
1207  * The internal structure declarations are read only when that is true.
1208  * Applications using the library should not include jpegint.h, but may wish
1209  * to include jerror.h.
1210  */
1211 
1212 #ifdef JPEG_INTERNALS
1213 #include "jpegint.h"            /* fetch private declarations */
1214 #include "jerror.h"             /* fetch error codes too */
1215 #endif
1216 
1217 #ifdef __cplusplus
1218 #ifndef DONT_USE_EXTERN_C
1219 }
1220 #endif
1221 #endif
1222 
1223 #endif /* JPEGLIB_H */