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