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 /*
  * jpeglib.h
  *
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1991-1998, Thomas G. Lane.
  * Modified 2002-2009 by Guido Vollbeding.
  * Lossless JPEG Modifications:
  * Copyright (C) 1999, Ken Murchison.
  * libjpeg-turbo Modifications:
  * Copyright (C) 2009-2011, 2013-2014, 2016-2017, 2020, 2022-2023,
              D. R. Commander.
  * Copyright (C) 2015, Google, Inc.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
  * This file defines the application interface for the JPEG library.
  * Most applications using the library need only include this file,
  * and perhaps jerror.h if they want to know the exact error codes.
  */
 
 #ifndef JPEGLIB_H
 #define JPEGLIB_H
 
 /*
  * First we include the configuration files that record how this
  * installation of the JPEG library is set up.  jconfig.h can be
  * generated automatically for many systems.  jmorecfg.h contains
  * manual configuration options that most people need not worry about.
  */
 
 #ifndef JCONFIG_INCLUDED        /* in case jinclude.h already did */
 #include "jconfig.h"            /* widely used configuration options */
 #endif
 #include "jmorecfg.h"           /* seldom changed options */
 
 
 #ifdef __cplusplus
 #ifndef DONT_USE_EXTERN_C
 extern "C" {
 #endif
 #endif
 
 
 /* Various constants determining the sizes of things.
  * All of these are specified by the JPEG standard, so don't change them
  * if you want to be compatible.
  */
 
 /* NOTE: In lossless mode, an MCU contains one or more samples rather than one
  * or more 8x8 DCT blocks, so the term "data unit" is used to generically
  * describe a sample in lossless mode or an 8x8 DCT block in lossy mode.  To
  * preserve backward API/ABI compatibility, the field and macro names retain
  * the "block" terminology.
  */
 
 #define DCTSIZE             8   /* The basic DCT block is 8x8 samples */
 #define DCTSIZE2            64  /* DCTSIZE squared; # of elements in a block */
 #define NUM_QUANT_TBLS      4   /* Quantization tables are numbered 0..3 */
 #define NUM_HUFF_TBLS       4   /* Huffman tables are numbered 0..3 */
 #define NUM_ARITH_TBLS      16  /* Arith-coding tables are numbered 0..15 */
 #define MAX_COMPS_IN_SCAN   4   /* JPEG limit on # of components in one scan */
 #define MAX_SAMP_FACTOR     4   /* JPEG limit on sampling factors */
 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
  * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
  * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
  * to handle it.  We even let you do this from the jconfig.h file.  However,
  * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
  * sometimes emits noncompliant files doesn't mean you should too.
  */
 #define C_MAX_BLOCKS_IN_MCU   10 /* compressor's limit on data units/MCU */
 #ifndef D_MAX_BLOCKS_IN_MCU
 #define D_MAX_BLOCKS_IN_MCU   10 /* decompressor's limit on data units/MCU */
 #endif
 
 
 /* Data structures for images (arrays of samples and of DCT coefficients).
  */
 
 typedef JSAMPLE *JSAMPROW;      /* ptr to one image row of pixel samples. */
 typedef JSAMPROW *JSAMPARRAY;   /* ptr to some rows (a 2-D sample array) */
 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
 
 typedef J12SAMPLE *J12SAMPROW;      /* ptr to one image row of 12-bit pixel
                                        samples. */
 typedef J12SAMPROW *J12SAMPARRAY;   /* ptr to some 12-bit sample rows (a 2-D
                                        12-bit sample array) */
 typedef J12SAMPARRAY *J12SAMPIMAGE; /* a 3-D 12-bit sample array: top index is
                                        color */
 
 typedef J16SAMPLE *J16SAMPROW;      /* ptr to one image row of 16-bit pixel
                                        samples. */
 typedef J16SAMPROW *J16SAMPARRAY;   /* ptr to some 16-bit sample rows (a 2-D
                                        16-bit sample array) */
 typedef J16SAMPARRAY *J16SAMPIMAGE; /* a 3-D 16-bit sample array: top index is
                                        color */
 
 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
 typedef JBLOCK *JBLOCKROW;      /* pointer to one row of coefficient blocks */
 typedef JBLOCKROW *JBLOCKARRAY;         /* a 2-D array of coefficient blocks */
 typedef JBLOCKARRAY *JBLOCKIMAGE;       /* a 3-D array of coefficient blocks */
 
 typedef JCOEF *JCOEFPTR;        /* useful in a couple of places */
 
 
 /* Types for JPEG compression parameters and working tables. */
 
 
 /* DCT coefficient quantization tables. */
 
 typedef struct {
   /* This array gives the coefficient quantizers in natural array order
    * (not the zigzag order in which they are stored in a JPEG DQT marker).
    * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
    */
   UINT16 quantval[DCTSIZE2];    /* quantization step for each coefficient */
   /* This field is used only during compression.  It's initialized FALSE when
    * the table is created, and set TRUE when it's been output to the file.
    * You could suppress output of a table by setting this to TRUE.
    * (See jpeg_suppress_tables for an example.)
    */
   boolean sent_table;           /* TRUE when table has been output */
 } JQUANT_TBL;
 
 
 /* Huffman coding tables. */
 
 typedef struct {
   /* These two fields directly represent the contents of a JPEG DHT marker */
   UINT8 bits[17];               /* bits[k] = # of symbols with codes of */
                                 /* length k bits; bits[0] is unused */
   UINT8 huffval[256];           /* The symbols, in order of incr code length */
   /* This field is used only during compression.  It's initialized FALSE when
    * the table is created, and set TRUE when it's been output to the file.
    * You could suppress output of a table by setting this to TRUE.
    * (See jpeg_suppress_tables for an example.)
    */
   boolean sent_table;           /* TRUE when table has been output */
 } JHUFF_TBL;
 
 
 /* Basic info about one component (color channel). */
 
 typedef struct {
   /* These values are fixed over the whole image. */
   /* For compression, they must be supplied by parameter setup; */
   /* for decompression, they are read from the SOF marker. */
   int component_id;             /* identifier for this component (0..255) */
   int component_index;          /* its index in SOF or cinfo->comp_info[] */
   int h_samp_factor;            /* horizontal sampling factor (1..4) */
   int v_samp_factor;            /* vertical sampling factor (1..4) */
   int quant_tbl_no;             /* quantization table selector (0..3) */
   /* These values may vary between scans. */
   /* For compression, they must be supplied by parameter setup; */
   /* for decompression, they are read from the SOS marker. */
   /* The decompressor output side may not use these variables. */
   int dc_tbl_no;                /* DC entropy table selector (0..3) */
   int ac_tbl_no;                /* AC entropy table selector (0..3) */
 
   /* Remaining fields should be treated as private by applications. */
 
   /* These values are computed during compression or decompression startup: */
   /* Component's size in data units.
    * In lossy mode, any dummy blocks added to complete an MCU are not counted;
    * therefore these values do not depend on whether a scan is interleaved or
    * not.  In lossless mode, these are always equal to the image width and
    * height.
    */
   JDIMENSION width_in_blocks;
   JDIMENSION height_in_blocks;
   /* Size of a data unit in samples.  Always DCTSIZE for lossy compression.
    * For lossy decompression this is the size of the output from one DCT block,
    * reflecting any scaling we choose to apply during the IDCT step.
    * Values from 1 to 16 are supported.  Note that different components may
    * receive different IDCT scalings.  In lossless mode, this is always equal
    * to 1.
    */
 #if JPEG_LIB_VERSION >= 70
   int DCT_h_scaled_size;
   int DCT_v_scaled_size;
 #else
   int DCT_scaled_size;
 #endif
   /* The downsampled dimensions are the component's actual, unpadded number
    * of samples at the main buffer (preprocessing/compression interface), thus
    * downsampled_width = ceil(image_width * Hi/Hmax)
    * and similarly for height.  For lossy decompression, IDCT scaling is
    * included, so
    * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]scaled_size/DCTSIZE)
    * In lossless mode, these are always equal to the image width and height.
    */
   JDIMENSION downsampled_width;  /* actual width in samples */
   JDIMENSION downsampled_height; /* actual height in samples */
   /* This flag is used only for decompression.  In cases where some of the
    * components will be ignored (eg grayscale output from YCbCr image),
    * we can skip most computations for the unused components.
    */
   boolean component_needed;     /* do we need the value of this component? */
 
   /* These values are computed before starting a scan of the component. */
   /* The decompressor output side may not use these variables. */
   int MCU_width;                /* number of data units per MCU, horizontally */
   int MCU_height;               /* number of data units per MCU, vertically */
   int MCU_blocks;               /* MCU_width * MCU_height */
   int MCU_sample_width;         /* MCU width in samples, MCU_width*DCT_[h_]scaled_size */
   int last_col_width;           /* # of non-dummy data units across in last MCU */
   int last_row_height;          /* # of non-dummy data units down in last MCU */
 
   /* Saved quantization table for component; NULL if none yet saved.
    * See jdinput.c comments about the need for this information.
    * This field is currently used only for decompression.
    */
   JQUANT_TBL *quant_table;
 
   /* Private per-component storage for DCT or IDCT subsystem. */
   void *dct_table;
 } jpeg_component_info;
 
 
 /* The script for encoding a multiple-scan file is an array of these: */
 
 typedef struct {
   int comps_in_scan;            /* number of components encoded in this scan */
   int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
   int Ss, Se;                   /* progressive JPEG spectral selection parms
                                    (Ss is the predictor selection value in
                                    lossless mode) */
   int Ah, Al;                   /* progressive JPEG successive approx. parms
                                    (Al is the point transform value in lossless
                                    mode) */
 } jpeg_scan_info;
 
 /* The decompressor can save APPn and COM markers in a list of these: */
 
 typedef struct jpeg_marker_struct *jpeg_saved_marker_ptr;
 
 struct jpeg_marker_struct {
   jpeg_saved_marker_ptr next;   /* next in list, or NULL */
   UINT8 marker;                 /* marker code: JPEG_COM, or JPEG_APP0+n */
   unsigned int original_length; /* # bytes of data in the file */
   unsigned int data_length;     /* # bytes of data saved at data[] */
   JOCTET *data;                 /* the data contained in the marker */
   /* the marker length word is not counted in data_length or original_length */
 };
 
 /* Known color spaces. */
 
 #define JCS_EXTENSIONS  1
 #define JCS_ALPHA_EXTENSIONS  1
 
 typedef enum {
   JCS_UNKNOWN,            /* error/unspecified */
   JCS_GRAYSCALE,          /* monochrome */
   JCS_RGB,                /* red/green/blue as specified by the RGB_RED,
                              RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros */
   JCS_YCbCr,              /* Y/Cb/Cr (also known as YUV) */
   JCS_CMYK,               /* C/M/Y/K */
   JCS_YCCK,               /* Y/Cb/Cr/K */
   JCS_EXT_RGB,            /* red/green/blue */
   JCS_EXT_RGBX,           /* red/green/blue/x */
   JCS_EXT_BGR,            /* blue/green/red */
   JCS_EXT_BGRX,           /* blue/green/red/x */
   JCS_EXT_XBGR,           /* x/blue/green/red */
   JCS_EXT_XRGB,           /* x/red/green/blue */
   /* When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX, JCS_EXT_XBGR,
      or JCS_EXT_XRGB during decompression, the X byte is undefined, and in
      order to ensure the best performance, libjpeg-turbo can set that byte to
      whatever value it wishes.  Use the following colorspace constants to
      ensure that the X byte is set to 0xFF, so that it can be interpreted as an
      opaque alpha channel. */
   JCS_EXT_RGBA,           /* red/green/blue/alpha */
   JCS_EXT_BGRA,           /* blue/green/red/alpha */
   JCS_EXT_ABGR,           /* alpha/blue/green/red */
   JCS_EXT_ARGB,           /* alpha/red/green/blue */
   JCS_RGB565              /* 5-bit red/6-bit green/5-bit blue
                              [decompression only] */
 } J_COLOR_SPACE;
 
 /* DCT/IDCT algorithm options. */
 
 typedef enum {
   JDCT_ISLOW,             /* accurate integer method */
   JDCT_IFAST,             /* less accurate integer method [legacy feature] */
   JDCT_FLOAT              /* floating-point method [legacy feature] */
 } J_DCT_METHOD;
 
 #ifndef JDCT_DEFAULT            /* may be overridden in jconfig.h */
 #define JDCT_DEFAULT  JDCT_ISLOW
 #endif
 #ifndef JDCT_FASTEST            /* may be overridden in jconfig.h */
 #define JDCT_FASTEST  JDCT_IFAST
 #endif
 
 /* Dithering options for decompression. */
 
 typedef enum {
   JDITHER_NONE,           /* no dithering */
   JDITHER_ORDERED,        /* simple ordered dither */
   JDITHER_FS              /* Floyd-Steinberg error diffusion dither */
 } J_DITHER_MODE;
 
 
 /* Common fields between JPEG compression and decompression master structs. */
 
 #define jpeg_common_fields \
   struct jpeg_error_mgr *err;   /* Error handler module */ \
   struct jpeg_memory_mgr *mem;  /* Memory manager module */ \
   struct jpeg_progress_mgr *progress; /* Progress monitor, or NULL if none */ \
   void *client_data;            /* Available for use by application */ \
   boolean is_decompressor;      /* So common code can tell which is which */ \
   int global_state              /* For checking call sequence validity */
 
 /* Routines that are to be used by both halves of the library are declared
  * to receive a pointer to this structure.  There are no actual instances of
  * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
  */
 struct jpeg_common_struct {
   jpeg_common_fields;           /* Fields common to both master struct types */
   /* Additional fields follow in an actual jpeg_compress_struct or
    * jpeg_decompress_struct.  All three structs must agree on these
    * initial fields!  (This would be a lot cleaner in C++.)
    */
 };
 
 typedef struct jpeg_common_struct *j_common_ptr;
 typedef struct jpeg_compress_struct *j_compress_ptr;
 typedef struct jpeg_decompress_struct *j_decompress_ptr;
 
 
 /* Master record for a compression instance */
 
 struct jpeg_compress_struct {
   jpeg_common_fields;           /* Fields shared with jpeg_decompress_struct */
 
   /* Destination for compressed data */
   struct jpeg_destination_mgr *dest;
 
   /* Description of source image --- these fields must be filled in by
    * outer application before starting compression.  in_color_space must
    * be correct before you can even call jpeg_set_defaults().
    */
 
   JDIMENSION image_width;       /* input image width */
   JDIMENSION image_height;      /* input image height */
   int input_components;         /* # of color components in input image */
   J_COLOR_SPACE in_color_space; /* colorspace of input image */
 
   double input_gamma;           /* image gamma of input image */
 
   /* Compression parameters --- these fields must be set before calling
    * jpeg_start_compress().  We recommend calling jpeg_set_defaults() to
    * initialize everything to reasonable defaults, then changing anything
    * the application specifically wants to change.  That way you won't get
    * burnt when new parameters are added.  Also note that there are several
    * helper routines to simplify changing parameters.
    */
 
 #if JPEG_LIB_VERSION >= 70
   unsigned int scale_num, scale_denom; /* fraction by which to scale image */
 
   JDIMENSION jpeg_width;        /* scaled JPEG image width */
   JDIMENSION jpeg_height;       /* scaled JPEG image height */
   /* Dimensions of actual JPEG image that will be written to file,
    * derived from input dimensions by scaling factors above.
    * These fields are computed by jpeg_start_compress().
    * You can also use jpeg_calc_jpeg_dimensions() to determine these values
    * in advance of calling jpeg_start_compress().
    */
 #endif
 
   int data_precision;           /* bits of precision in image data */
 
   int num_components;           /* # of color components in JPEG image */
   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
 
   jpeg_component_info *comp_info;
   /* comp_info[i] describes component that appears i'th in SOF */
 
   JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
 #if JPEG_LIB_VERSION >= 70
   int q_scale_factor[NUM_QUANT_TBLS];
 #endif
   /* ptrs to coefficient quantization tables, or NULL if not defined,
    * and corresponding scale factors (percentage, initialized 100).
    */
 
   JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
   JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
   /* ptrs to Huffman coding tables, or NULL if not defined */
 
   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
 
   int num_scans;                /* # of entries in scan_info array */
   const jpeg_scan_info *scan_info; /* script for multi-scan file, or NULL */
   /* The default value of scan_info is NULL, which causes a single-scan
    * sequential JPEG file to be emitted.  To create a multi-scan file,
    * set num_scans and scan_info to point to an array of scan definitions.
    */
 
   boolean raw_data_in;          /* TRUE=caller supplies downsampled data */
   boolean arith_code;           /* TRUE=arithmetic coding, FALSE=Huffman */
   boolean optimize_coding;      /* TRUE=optimize entropy encoding parms */
   boolean CCIR601_sampling;     /* TRUE=first samples are cosited */
 #if JPEG_LIB_VERSION >= 70
   boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
 #endif
   int smoothing_factor;         /* 1..100, or 0 for no input smoothing */
   J_DCT_METHOD dct_method;      /* DCT algorithm selector */
 
   /* The restart interval can be specified in absolute MCUs by setting
    * restart_interval, or in MCU rows by setting restart_in_rows
    * (in which case the correct restart_interval will be figured
    * for each scan).
    */
   unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
   int restart_in_rows;          /* if > 0, MCU rows per restart interval */
 
   /* Parameters controlling emission of special markers. */
 
   boolean write_JFIF_header;    /* should a JFIF marker be written? */
   UINT8 JFIF_major_version;     /* What to write for the JFIF version number */
   UINT8 JFIF_minor_version;
   /* These three values are not used by the JPEG code, merely copied */
   /* into the JFIF APP0 marker.  density_unit can be 0 for unknown, */
   /* 1 for dots/inch, or 2 for dots/cm.  Note that the pixel aspect */
   /* ratio is defined by X_density/Y_density even when density_unit=0. */
   UINT8 density_unit;           /* JFIF code for pixel size units */
   UINT16 X_density;             /* Horizontal pixel density */
   UINT16 Y_density;             /* Vertical pixel density */
   boolean write_Adobe_marker;   /* should an Adobe marker be written? */
 
   /* State variable: index of next scanline to be written to
    * jpeg_write_scanlines().  Application may use this to control its
    * processing loop, e.g., "while (next_scanline < image_height)".
    */
 
   JDIMENSION next_scanline;     /* 0 .. image_height-1  */
 
   /* Remaining fields are known throughout compressor, but generally
    * should not be touched by a surrounding application.
    */
 
   /*
    * These fields are computed during compression startup
    */
   boolean progressive_mode;     /* TRUE if scan script uses progressive mode */
   int max_h_samp_factor;        /* largest h_samp_factor */
   int max_v_samp_factor;        /* largest v_samp_factor */
 
 #if JPEG_LIB_VERSION >= 70
   int min_DCT_h_scaled_size;    /* smallest DCT_h_scaled_size of any component */
   int min_DCT_v_scaled_size;    /* smallest DCT_v_scaled_size of any component */
 #endif
 
   JDIMENSION total_iMCU_rows;   /* # of iMCU rows to be input to coefficient or
                                    difference controller */
   /* The coefficient or difference controller receives data in units of MCU
    * rows as defined for fully interleaved scans (whether the JPEG file is
    * interleaved or not).  In lossy mode, there are v_samp_factor * DCTSIZE
    * sample rows of each component in an "iMCU" (interleaved MCU) row.  In
    * lossless mode, total_iMCU_rows is always equal to the image height.
    */
 
   /*
    * These fields are valid during any one scan.
    * They describe the components and MCUs actually appearing in the scan.
    */
   int comps_in_scan;            /* # of JPEG components in this scan */
   jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
   /* *cur_comp_info[i] describes component that appears i'th in SOS */
 
   JDIMENSION MCUs_per_row;      /* # of MCUs across the image */
   JDIMENSION MCU_rows_in_scan;  /* # of MCU rows in the image */
 
   int blocks_in_MCU;            /* # of data units per MCU */
   int MCU_membership[C_MAX_BLOCKS_IN_MCU];
   /* MCU_membership[i] is index in cur_comp_info of component owning */
   /* i'th data unit in an MCU */
 
   int Ss, Se, Ah, Al;           /* progressive/lossless JPEG parameters for
                                    scan */
 
 #if JPEG_LIB_VERSION >= 80
   int block_size;               /* the basic DCT block size: 1..16 */
   const int *natural_order;     /* natural-order position array */
   int lim_Se;                   /* min( Se, DCTSIZE2-1 ) */
 #endif
 
   /*
    * Links to compression subobjects (methods and private variables of modules)
    */
   struct jpeg_comp_master *master;
   struct jpeg_c_main_controller *main;
   struct jpeg_c_prep_controller *prep;
   struct jpeg_c_coef_controller *coef;
   struct jpeg_marker_writer *marker;
   struct jpeg_color_converter *cconvert;
   struct jpeg_downsampler *downsample;
   struct jpeg_forward_dct *fdct;
   struct jpeg_entropy_encoder *entropy;
   jpeg_scan_info *script_space; /* workspace for jpeg_simple_progression */
   int script_space_size;
 };
 
 
 /* Master record for a decompression instance */
 
 struct jpeg_decompress_struct {
   jpeg_common_fields;           /* Fields shared with jpeg_compress_struct */
 
   /* Source of compressed data */
   struct jpeg_source_mgr *src;
 
   /* Basic description of image --- filled in by jpeg_read_header(). */
   /* Application may inspect these values to decide how to process image. */
 
   JDIMENSION image_width;       /* nominal image width (from SOF marker) */
   JDIMENSION image_height;      /* nominal image height */
   int num_components;           /* # of color components in JPEG image */
   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
 
   /* Decompression processing parameters --- these fields must be set before
    * calling jpeg_start_decompress().  Note that jpeg_read_header() initializes
    * them to default values.
    */
 
   J_COLOR_SPACE out_color_space; /* colorspace for output */
 
   unsigned int scale_num, scale_denom; /* fraction by which to scale image */
 
   double output_gamma;          /* image gamma wanted in output */
 
   boolean buffered_image;       /* TRUE=multiple output passes */
   boolean raw_data_out;         /* TRUE=downsampled data wanted */
 
   J_DCT_METHOD dct_method;      /* IDCT algorithm selector */
   boolean do_fancy_upsampling;  /* TRUE=apply fancy upsampling */
   boolean do_block_smoothing;   /* TRUE=apply interblock smoothing */
 
   boolean quantize_colors;      /* TRUE=colormapped output wanted */
   /* the following are ignored if not quantize_colors: */
   J_DITHER_MODE dither_mode;    /* type of color dithering to use */
   boolean two_pass_quantize;    /* TRUE=use two-pass color quantization */
   int desired_number_of_colors; /* max # colors to use in created colormap */
   /* these are significant only in buffered-image mode: */
   boolean enable_1pass_quant;   /* enable future use of 1-pass quantizer */
   boolean enable_external_quant;/* enable future use of external colormap */
   boolean enable_2pass_quant;   /* enable future use of 2-pass quantizer */
 
   /* Description of actual output image that will be returned to application.
    * These fields are computed by jpeg_start_decompress().
    * You can also use jpeg_calc_output_dimensions() to determine these values
    * in advance of calling jpeg_start_decompress().
    */
 
   JDIMENSION output_width;      /* scaled image width */
   JDIMENSION output_height;     /* scaled image height */
   int out_color_components;     /* # of color components in out_color_space */
   int output_components;        /* # of color components returned */
   /* output_components is 1 (a colormap index) when quantizing colors;
    * otherwise it equals out_color_components.
    */
   int rec_outbuf_height;        /* min recommended height of scanline buffer */
   /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
    * high, space and time will be wasted due to unnecessary data copying.
    * Usually rec_outbuf_height will be 1 or 2, at most 4.
    */
 
   /* When quantizing colors, the output colormap is described by these fields.
    * The application can supply a colormap by setting colormap non-NULL before
    * calling jpeg_start_decompress; otherwise a colormap is created during
    * jpeg_start_decompress or jpeg_start_output.
    * The map has out_color_components rows and actual_number_of_colors columns.
    */
   int actual_number_of_colors;  /* number of entries in use */
   JSAMPARRAY colormap;          /* The color map as a 2-D pixel array
                                    If data_precision is 12 or 16, then this is
                                    actually a J12SAMPARRAY or a J16SAMPARRAY,
                                    so callers must type-cast it in order to
                                    read/write 12-bit or 16-bit samples from/to
                                    the array. */
 
   /* State variables: these variables indicate the progress of decompression.
    * The application may examine these but must not modify them.
    */
 
   /* Row index of next scanline to be read from jpeg_read_scanlines().
    * Application may use this to control its processing loop, e.g.,
    * "while (output_scanline < output_height)".
    */
   JDIMENSION output_scanline;   /* 0 .. output_height-1  */
 
   /* Current input scan number and number of iMCU rows completed in scan.
    * These indicate the progress of the decompressor input side.
    */
   int input_scan_number;        /* Number of SOS markers seen so far */
   JDIMENSION input_iMCU_row;    /* Number of iMCU rows completed */
 
   /* The "output scan number" is the notional scan being displayed by the
    * output side.  The decompressor will not allow output scan/row number
    * to get ahead of input scan/row, but it can fall arbitrarily far behind.
    */
   int output_scan_number;       /* Nominal scan number being displayed */
   JDIMENSION output_iMCU_row;   /* Number of iMCU rows read */
 
   /* Current progression status.  coef_bits[c][i] indicates the precision
    * with which component c's DCT coefficient i (in zigzag order) is known.
    * It is -1 when no data has yet been received, otherwise it is the point
    * transform (shift) value for the most recent scan of the coefficient
    * (thus, 0 at completion of the progression).
    * This pointer is NULL when reading a non-progressive file.
    */
   int (*coef_bits)[DCTSIZE2];   /* -1 or current Al value for each coef */
 
   /* Internal JPEG parameters --- the application usually need not look at
    * these fields.  Note that the decompressor output side may not use
    * any parameters that can change between scans.
    */
 
   /* Quantization and Huffman tables are carried forward across input
    * datastreams when processing abbreviated JPEG datastreams.
    */
 
   JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
   /* ptrs to coefficient quantization tables, or NULL if not defined */
 
   JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
   JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
   /* ptrs to Huffman coding tables, or NULL if not defined */
 
   /* These parameters are never carried across datastreams, since they
    * are given in SOF/SOS markers or defined to be reset by SOI.
    */
 
   int data_precision;           /* bits of precision in image data */
 
   jpeg_component_info *comp_info;
   /* comp_info[i] describes component that appears i'th in SOF */
 
 #if JPEG_LIB_VERSION >= 80
   boolean is_baseline;          /* TRUE if Baseline SOF0 encountered */
 #endif
   boolean progressive_mode;     /* TRUE if SOFn specifies progressive mode */
   boolean arith_code;           /* TRUE=arithmetic coding, FALSE=Huffman */
 
   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
 
   unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
 
   /* These fields record data obtained from optional markers recognized by
    * the JPEG library.
    */
   boolean saw_JFIF_marker;      /* TRUE iff a JFIF APP0 marker was found */
   /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
   UINT8 JFIF_major_version;     /* JFIF version number */
   UINT8 JFIF_minor_version;
   UINT8 density_unit;           /* JFIF code for pixel size units */
   UINT16 X_density;             /* Horizontal pixel density */
   UINT16 Y_density;             /* Vertical pixel density */
   boolean saw_Adobe_marker;     /* TRUE iff an Adobe APP14 marker was found */
   UINT8 Adobe_transform;        /* Color transform code from Adobe marker */
 
   boolean CCIR601_sampling;     /* TRUE=first samples are cosited */
 
   /* Aside from the specific data retained from APPn markers known to the
    * library, the uninterpreted contents of any or all APPn and COM markers
    * can be saved in a list for examination by the application.
    */
   jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
 
   /* Remaining fields are known throughout decompressor, but generally
    * should not be touched by a surrounding application.
    */
 
   /*
    * These fields are computed during decompression startup
    */
   int max_h_samp_factor;        /* largest h_samp_factor */
   int max_v_samp_factor;        /* largest v_samp_factor */
 
 #if JPEG_LIB_VERSION >= 70
   int min_DCT_h_scaled_size;    /* smallest DCT_h_scaled_size of any component */
   int min_DCT_v_scaled_size;    /* smallest DCT_v_scaled_size of any component */
 #else
   int min_DCT_scaled_size;      /* smallest DCT_scaled_size of any component */
 #endif
 
   JDIMENSION total_iMCU_rows;   /* # of iMCU rows in image */
   /* The coefficient or difference controller's input and output progress is
    * measured in units of "iMCU" (interleaved MCU) rows.  These are the same as
    * MCU rows in fully interleaved JPEG scans, but are used whether the scan is
    * interleaved or not.  In lossy mode, we define an iMCU row as v_samp_factor
    * DCT block rows of each component.  Therefore, the IDCT output contains
    * v_samp_factor*DCT_[v_]scaled_size sample rows of a component per iMCU row.
    * In lossless mode, total_iMCU_rows is always equal to the image height.
    */
 
   JSAMPLE *sample_range_limit;  /* table for fast range-limiting
                                    If data_precision is 12 or 16, then this is
                                    actually a J12SAMPLE pointer or a J16SAMPLE
                                    pointer, so callers must type-cast it in
                                    order to read 12-bit or 16-bit samples from
                                    the array. */
 
   /*
    * These fields are valid during any one scan.
    * They describe the components and MCUs actually appearing in the scan.
    * Note that the decompressor output side must not use these fields.
    */
   int comps_in_scan;            /* # of JPEG components in this scan */
   jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
   /* *cur_comp_info[i] describes component that appears i'th in SOS */
 
   JDIMENSION MCUs_per_row;      /* # of MCUs across the image */
   JDIMENSION MCU_rows_in_scan;  /* # of MCU rows in the image */
 
   int blocks_in_MCU;            /* # of data units per MCU */
   int MCU_membership[D_MAX_BLOCKS_IN_MCU];
   /* MCU_membership[i] is index in cur_comp_info of component owning */
   /* i'th data unit in an MCU */
 
   int Ss, Se, Ah, Al;           /* progressive/lossless JPEG parameters for
                                    scan */
 
 #if JPEG_LIB_VERSION >= 80
   /* These fields are derived from Se of first SOS marker.
    */
   int block_size;               /* the basic DCT block size: 1..16 */
   const int *natural_order; /* natural-order position array for entropy decode */
   int lim_Se;                   /* min( Se, DCTSIZE2-1 ) for entropy decode */
 #endif
 
   /* This field is shared between entropy decoder and marker parser.
    * It is either zero or the code of a JPEG marker that has been
    * read from the data source, but has not yet been processed.
    */
   int unread_marker;
 
   /*
    * Links to decompression subobjects (methods, private variables of modules)
    */
   struct jpeg_decomp_master *master;
   struct jpeg_d_main_controller *main;
   struct jpeg_d_coef_controller *coef;
   struct jpeg_d_post_controller *post;
   struct jpeg_input_controller *inputctl;
   struct jpeg_marker_reader *marker;
   struct jpeg_entropy_decoder *entropy;
   struct jpeg_inverse_dct *idct;
   struct jpeg_upsampler *upsample;
   struct jpeg_color_deconverter *cconvert;
   struct jpeg_color_quantizer *cquantize;
 };
 
 
 /* "Object" declarations for JPEG modules that may be supplied or called
  * directly by the surrounding application.
  * As with all objects in the JPEG library, these structs only define the
  * publicly visible methods and state variables of a module.  Additional
  * private fields may exist after the public ones.
  */
 
 
 /* Error handler object */
 
 struct jpeg_error_mgr {
   /* Error exit handler: does not return to caller */
   void (*error_exit) (j_common_ptr cinfo);
   /* Conditionally emit a trace or warning message */
   void (*emit_message) (j_common_ptr cinfo, int msg_level);
   /* Routine that actually outputs a trace or error message */
   void (*output_message) (j_common_ptr cinfo);
   /* Format a message string for the most recent JPEG error or message */
   void (*format_message) (j_common_ptr cinfo, char *buffer);
 #define JMSG_LENGTH_MAX  200    /* recommended size of format_message buffer */
   /* Reset error state variables at start of a new image */
   void (*reset_error_mgr) (j_common_ptr cinfo);
 
   /* The message ID code and any parameters are saved here.
    * A message can have one string parameter or up to 8 int parameters.
    */
   int msg_code;
 #define JMSG_STR_PARM_MAX  80
   union {
     int i[8];
     char s[JMSG_STR_PARM_MAX];
   } msg_parm;
 
   /* Standard state variables for error facility */
 
   int trace_level;              /* max msg_level that will be displayed */
 
   /* For recoverable corrupt-data errors, we emit a warning message,
    * but keep going unless emit_message chooses to abort.  emit_message
    * should count warnings in num_warnings.  The surrounding application
    * can check for bad data by seeing if num_warnings is nonzero at the
    * end of processing.
    */
   long num_warnings;            /* number of corrupt-data warnings */
 
   /* These fields point to the table(s) of error message strings.
    * An application can change the table pointer to switch to a different
    * message list (typically, to change the language in which errors are
    * reported).  Some applications may wish to add additional error codes
    * that will be handled by the JPEG library error mechanism; the second
    * table pointer is used for this purpose.
    *
    * First table includes all errors generated by JPEG library itself.
    * Error code 0 is reserved for a "no such error string" message.
    */
   const char * const *jpeg_message_table; /* Library errors */
   int last_jpeg_message;    /* Table contains strings 0..last_jpeg_message */
   /* Second table can be added by application (see cjpeg/djpeg for example).
    * It contains strings numbered first_addon_message..last_addon_message.
    */
   const char * const *addon_message_table; /* Non-library errors */
   int first_addon_message;      /* code for first string in addon table */
   int last_addon_message;       /* code for last string in addon table */
 };
 
 
 /* Progress monitor object */
 
 struct jpeg_progress_mgr {
   void (*progress_monitor) (j_common_ptr cinfo);
 
   long pass_counter;            /* work units completed in this pass */
   long pass_limit;              /* total number of work units in this pass */
   int completed_passes;         /* passes completed so far */
   int total_passes;             /* total number of passes expected */
 };
 
 
 /* Data destination object for compression */
 
 struct jpeg_destination_mgr {
   JOCTET *next_output_byte;     /* => next byte to write in buffer */
   size_t free_in_buffer;        /* # of byte spaces remaining in buffer */
 
   void (*init_destination) (j_compress_ptr cinfo);
   boolean (*empty_output_buffer) (j_compress_ptr cinfo);
   void (*term_destination) (j_compress_ptr cinfo);
 };
 
 
 /* Data source object for decompression */
 
 struct jpeg_source_mgr {
   const JOCTET *next_input_byte; /* => next byte to read from buffer */
   size_t bytes_in_buffer;       /* # of bytes remaining in buffer */
 
   void (*init_source) (j_decompress_ptr cinfo);
   boolean (*fill_input_buffer) (j_decompress_ptr cinfo);
   void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes);
   boolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired);
   void (*term_source) (j_decompress_ptr cinfo);
 };
 
 
 /* Memory manager object.
  * Allocates "small" objects (a few K total), "large" objects (tens of K),
  * and "really big" objects (virtual arrays with backing store if needed).
  * The memory manager does not allow individual objects to be freed; rather,
  * each created object is assigned to a pool, and whole pools can be freed
  * at once.  This is faster and more convenient than remembering exactly what
  * to free, especially where malloc()/free() are not too speedy.
  * NB: alloc routines never return NULL.  They exit to error_exit if not
  * successful.
  */
 
 #define JPOOL_PERMANENT  0      /* lasts until master record is destroyed */
 #define JPOOL_IMAGE      1      /* lasts until done with image/datastream */
 #define JPOOL_NUMPOOLS   2
 
 typedef struct jvirt_sarray_control *jvirt_sarray_ptr;
 typedef struct jvirt_barray_control *jvirt_barray_ptr;
 
 
 struct jpeg_memory_mgr {
   /* Method pointers */
   void *(*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject);
   void *(*alloc_large) (j_common_ptr cinfo, int pool_id,
                         size_t sizeofobject);
   /* If cinfo->data_precision is 12 or 16, then this method and the
    * access_virt_sarray method actually return a J12SAMPARRAY or a
    * J16SAMPARRAY, so callers must type-cast the return value in order to
    * read/write 12-bit or 16-bit samples from/to the array.
    */
   JSAMPARRAY (*alloc_sarray) (j_common_ptr cinfo, int pool_id,
                               JDIMENSION samplesperrow, JDIMENSION numrows);
   JBLOCKARRAY (*alloc_barray) (j_common_ptr cinfo, int pool_id,
                                JDIMENSION blocksperrow, JDIMENSION numrows);
   jvirt_sarray_ptr (*request_virt_sarray) (j_common_ptr cinfo, int pool_id,
                                            boolean pre_zero,
                                            JDIMENSION samplesperrow,
                                            JDIMENSION numrows,
                                            JDIMENSION maxaccess);
   jvirt_barray_ptr (*request_virt_barray) (j_common_ptr cinfo, int pool_id,
                                            boolean pre_zero,
                                            JDIMENSION blocksperrow,
                                            JDIMENSION numrows,
                                            JDIMENSION maxaccess);
   void (*realize_virt_arrays) (j_common_ptr cinfo);
   JSAMPARRAY (*access_virt_sarray) (j_common_ptr cinfo, jvirt_sarray_ptr ptr,
                                     JDIMENSION start_row, JDIMENSION num_rows,
                                     boolean writable);
   JBLOCKARRAY (*access_virt_barray) (j_common_ptr cinfo, jvirt_barray_ptr ptr,
                                      JDIMENSION start_row, JDIMENSION num_rows,
                                      boolean writable);
   void (*free_pool) (j_common_ptr cinfo, int pool_id);
   void (*self_destruct) (j_common_ptr cinfo);
 
   /* Limit on memory allocation for this JPEG object.  (Note that this is
    * merely advisory, not a guaranteed maximum; it only affects the space
    * used for virtual-array buffers.)  May be changed by outer application
    * after creating the JPEG object.
    */
   long max_memory_to_use;
 
   /* Maximum allocation request accepted by alloc_large. */
   long max_alloc_chunk;
 };
 
 
 /* Routine signature for application-supplied marker processing methods.
  * Need not pass marker code since it is stored in cinfo->unread_marker.
  */
 typedef boolean (*jpeg_marker_parser_method) (j_decompress_ptr cinfo);
 
 
 /* Originally, this macro was used as a way of defining function prototypes
  * for both modern compilers as well as older compilers that did not support
  * prototype parameters.  libjpeg-turbo has never supported these older,
  * non-ANSI compilers, but the macro is still included because there is some
  * software out there that uses it.
  */
 
 #define JPP(arglist)    arglist
 
 
 /* Default error-management setup */
 EXTERN(struct jpeg_error_mgr *) jpeg_std_error(struct jpeg_error_mgr *err);
 
 /* Initialization of JPEG compression objects.
  * jpeg_create_compress() and jpeg_create_decompress() are the exported
  * names that applications should call.  These expand to calls on
  * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
  * passed for version mismatch checking.
  * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
  */
 #define jpeg_create_compress(cinfo) \
   jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
                       (size_t)sizeof(struct jpeg_compress_struct))
 #define jpeg_create_decompress(cinfo) \
   jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
                         (size_t)sizeof(struct jpeg_decompress_struct))
 EXTERN(void) jpeg_CreateCompress(j_compress_ptr cinfo, int version,
                                  size_t structsize);
 EXTERN(void) jpeg_CreateDecompress(j_decompress_ptr cinfo, int version,
                                    size_t structsize);
 /* Destruction of JPEG compression objects */
 EXTERN(void) jpeg_destroy_compress(j_compress_ptr cinfo);
 EXTERN(void) jpeg_destroy_decompress(j_decompress_ptr cinfo);
 
 /* Standard data source and destination managers: stdio streams. */
 /* Caller is responsible for opening the file before and closing after. */
 EXTERN(void) jpeg_stdio_dest(j_compress_ptr cinfo, FILE *outfile);
 EXTERN(void) jpeg_stdio_src(j_decompress_ptr cinfo, FILE *infile);
 
 /* Data source and destination managers: memory buffers. */
 EXTERN(void) jpeg_mem_dest(j_compress_ptr cinfo, unsigned char **outbuffer,
                            unsigned long *outsize);
 EXTERN(void) jpeg_mem_src(j_decompress_ptr cinfo,
                           const unsigned char *inbuffer, unsigned long insize);
 
 /* Default parameter setup for compression */
 EXTERN(void) jpeg_set_defaults(j_compress_ptr cinfo);
 /* Compression parameter setup aids */
 EXTERN(void) jpeg_set_colorspace(j_compress_ptr cinfo,
                                  J_COLOR_SPACE colorspace);
 EXTERN(void) jpeg_default_colorspace(j_compress_ptr cinfo);
 EXTERN(void) jpeg_set_quality(j_compress_ptr cinfo, int quality,
                               boolean force_baseline);
 EXTERN(void) jpeg_set_linear_quality(j_compress_ptr cinfo, int scale_factor,
                                      boolean force_baseline);
 #if JPEG_LIB_VERSION >= 70
 EXTERN(void) jpeg_default_qtables(j_compress_ptr cinfo,
                                   boolean force_baseline);
 #endif
 EXTERN(void) jpeg_add_quant_table(j_compress_ptr cinfo, int which_tbl,
                                   const unsigned int *basic_table,
                                   int scale_factor, boolean force_baseline);
 EXTERN(int) jpeg_quality_scaling(int quality);
 EXTERN(void) jpeg_enable_lossless(j_compress_ptr cinfo,
                                   int predictor_selection_value,
                                   int point_transform);
 EXTERN(void) jpeg_simple_progression(j_compress_ptr cinfo);
 EXTERN(void) jpeg_suppress_tables(j_compress_ptr cinfo, boolean suppress);
 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table(j_common_ptr cinfo);
 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table(j_common_ptr cinfo);
 
 /* Main entry points for compression */
 EXTERN(void) jpeg_start_compress(j_compress_ptr cinfo,
                                  boolean write_all_tables);
 EXTERN(JDIMENSION) jpeg_write_scanlines(j_compress_ptr cinfo,
                                         JSAMPARRAY scanlines,
                                         JDIMENSION num_lines);
 EXTERN(JDIMENSION) jpeg12_write_scanlines(j_compress_ptr cinfo,
                                           J12SAMPARRAY scanlines,
                                           JDIMENSION num_lines);
 EXTERN(JDIMENSION) jpeg16_write_scanlines(j_compress_ptr cinfo,
                                           J16SAMPARRAY scanlines,
                                           JDIMENSION num_lines);
 EXTERN(void) jpeg_finish_compress(j_compress_ptr cinfo);
 
 #if JPEG_LIB_VERSION >= 70
 /* Precalculate JPEG dimensions for current compression parameters. */
 EXTERN(void) jpeg_calc_jpeg_dimensions(j_compress_ptr cinfo);
 #endif
 
 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
 EXTERN(JDIMENSION) jpeg_write_raw_data(j_compress_ptr cinfo, JSAMPIMAGE data,
                                        JDIMENSION num_lines);
 EXTERN(JDIMENSION) jpeg12_write_raw_data(j_compress_ptr cinfo,
                                          J12SAMPIMAGE data,
                                          JDIMENSION num_lines);
 
 /* Write a special marker.  See libjpeg.txt concerning safe usage. */
 EXTERN(void) jpeg_write_marker(j_compress_ptr cinfo, int marker,
                                const JOCTET *dataptr, unsigned int datalen);
 /* Same, but piecemeal. */
 EXTERN(void) jpeg_write_m_header(j_compress_ptr cinfo, int marker,
                                  unsigned int datalen);
 EXTERN(void) jpeg_write_m_byte(j_compress_ptr cinfo, int val);
 
 /* Alternate compression function: just write an abbreviated table file */
 EXTERN(void) jpeg_write_tables(j_compress_ptr cinfo);
 
 /* Write ICC profile.  See libjpeg.txt for usage information. */
 EXTERN(void) jpeg_write_icc_profile(j_compress_ptr cinfo,
                                     const JOCTET *icc_data_ptr,
                                     unsigned int icc_data_len);
 
 
 /* Decompression startup: read start of JPEG datastream to see what's there */
 EXTERN(int) jpeg_read_header(j_decompress_ptr cinfo, boolean require_image);
 /* Return value is one of: */
 #define JPEG_SUSPENDED           0 /* Suspended due to lack of input data */
 #define JPEG_HEADER_OK           1 /* Found valid image datastream */
 #define JPEG_HEADER_TABLES_ONLY  2 /* Found valid table-specs-only datastream */
 /* If you pass require_image = TRUE (normal case), you need not check for
  * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
  * JPEG_SUSPENDED is only possible if you use a data source module that can
  * give a suspension return (the stdio source module doesn't).
  */
 
 /* Main entry points for decompression */
 EXTERN(boolean) jpeg_start_decompress(j_decompress_ptr cinfo);
 EXTERN(JDIMENSION) jpeg_read_scanlines(j_decompress_ptr cinfo,
                                        JSAMPARRAY scanlines,
                                        JDIMENSION max_lines);
 EXTERN(JDIMENSION) jpeg12_read_scanlines(j_decompress_ptr cinfo,
                                          J12SAMPARRAY scanlines,
                                          JDIMENSION max_lines);
 EXTERN(JDIMENSION) jpeg16_read_scanlines(j_decompress_ptr cinfo,
                                          J16SAMPARRAY scanlines,
                                          JDIMENSION max_lines);
 EXTERN(JDIMENSION) jpeg_skip_scanlines(j_decompress_ptr cinfo,
                                        JDIMENSION num_lines);
 EXTERN(JDIMENSION) jpeg12_skip_scanlines(j_decompress_ptr cinfo,
                                          JDIMENSION num_lines);
 EXTERN(void) jpeg_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
                                 JDIMENSION *width);
 EXTERN(void) jpeg12_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
                                   JDIMENSION *width);
 EXTERN(boolean) jpeg_finish_decompress(j_decompress_ptr cinfo);
 
 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
 EXTERN(JDIMENSION) jpeg_read_raw_data(j_decompress_ptr cinfo, JSAMPIMAGE data,
                                       JDIMENSION max_lines);
 EXTERN(JDIMENSION) jpeg12_read_raw_data(j_decompress_ptr cinfo,
                                         J12SAMPIMAGE data,
                                         JDIMENSION max_lines);
 
 /* Additional entry points for buffered-image mode. */
 EXTERN(boolean) jpeg_has_multiple_scans(j_decompress_ptr cinfo);
 EXTERN(boolean) jpeg_start_output(j_decompress_ptr cinfo, int scan_number);
 EXTERN(boolean) jpeg_finish_output(j_decompress_ptr cinfo);
 EXTERN(boolean) jpeg_input_complete(j_decompress_ptr cinfo);
 EXTERN(void) jpeg_new_colormap(j_decompress_ptr cinfo);
 EXTERN(int) jpeg_consume_input(j_decompress_ptr cinfo);
 /* Return value is one of: */
 /* #define JPEG_SUSPENDED       0    Suspended due to lack of input data */
 #define JPEG_REACHED_SOS        1 /* Reached start of new scan */
 #define JPEG_REACHED_EOI        2 /* Reached end of image */
 #define JPEG_ROW_COMPLETED      3 /* Completed one iMCU row */
 #define JPEG_SCAN_COMPLETED     4 /* Completed last iMCU row of a scan */
 
 /* Precalculate output dimensions for current decompression parameters. */
 #if JPEG_LIB_VERSION >= 80
 EXTERN(void) jpeg_core_output_dimensions(j_decompress_ptr cinfo);
 #endif
 EXTERN(void) jpeg_calc_output_dimensions(j_decompress_ptr cinfo);
 
 /* Control saving of COM and APPn markers into marker_list. */
 EXTERN(void) jpeg_save_markers(j_decompress_ptr cinfo, int marker_code,
                                unsigned int length_limit);
 
 /* Install a special processing method for COM or APPn markers. */
 EXTERN(void) jpeg_set_marker_processor(j_decompress_ptr cinfo,
                                        int marker_code,
                                        jpeg_marker_parser_method routine);
 
 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients(j_decompress_ptr cinfo);
 EXTERN(void) jpeg_write_coefficients(j_compress_ptr cinfo,
                                      jvirt_barray_ptr *coef_arrays);
 EXTERN(void) jpeg_copy_critical_parameters(j_decompress_ptr srcinfo,
                                            j_compress_ptr dstinfo);
 
 /* If you choose to abort compression or decompression before completing
  * jpeg_finish_(de)compress, then you need to clean up to release memory,
  * temporary files, etc.  You can just call jpeg_destroy_(de)compress
  * if you're done with the JPEG object, but if you want to clean it up and
  * reuse it, call this:
  */
 EXTERN(void) jpeg_abort_compress(j_compress_ptr cinfo);
 EXTERN(void) jpeg_abort_decompress(j_decompress_ptr cinfo);
 
 /* Generic versions of jpeg_abort and jpeg_destroy that work on either
  * flavor of JPEG object.  These may be more convenient in some places.
  */
 EXTERN(void) jpeg_abort(j_common_ptr cinfo);
 EXTERN(void) jpeg_destroy(j_common_ptr cinfo);
 
 /* Default restart-marker-resync procedure for use by data source modules */
 EXTERN(boolean) jpeg_resync_to_restart(j_decompress_ptr cinfo, int desired);
 
 /* Read ICC profile.  See libjpeg.txt for usage information. */
 EXTERN(boolean) jpeg_read_icc_profile(j_decompress_ptr cinfo,
                                       JOCTET **icc_data_ptr,
                                       unsigned int *icc_data_len);
 
 
 /* These marker codes are exported since applications and data source modules
  * are likely to want to use them.
  */
 
 #define JPEG_RST0       0xD0    /* RST0 marker code */
 #define JPEG_EOI        0xD9    /* EOI marker code */
 #define JPEG_APP0       0xE0    /* APP0 marker code */
 #define JPEG_COM        0xFE    /* COM marker code */
 
 
 /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
  * for structure definitions that are never filled in, keep it quiet by
  * supplying dummy definitions for the various substructures.
  */
 
 #ifdef INCOMPLETE_TYPES_BROKEN
 #ifndef JPEG_INTERNALS          /* will be defined in jpegint.h */
 struct jvirt_sarray_control { long dummy; };
 struct jvirt_barray_control { long dummy; };
 struct jpeg_comp_master { long dummy; };
 struct jpeg_c_main_controller { long dummy; };
 struct jpeg_c_prep_controller { long dummy; };
 struct jpeg_c_coef_controller { long dummy; };
 struct jpeg_marker_writer { long dummy; };
 struct jpeg_color_converter { long dummy; };
 struct jpeg_downsampler { long dummy; };
 struct jpeg_forward_dct { long dummy; };
 struct jpeg_entropy_encoder { long dummy; };
 struct jpeg_decomp_master { long dummy; };
 struct jpeg_d_main_controller { long dummy; };
 struct jpeg_d_coef_controller { long dummy; };
 struct jpeg_d_post_controller { long dummy; };
 struct jpeg_input_controller { long dummy; };
 struct jpeg_marker_reader { long dummy; };
 struct jpeg_entropy_decoder { long dummy; };
 struct jpeg_inverse_dct { long dummy; };
 struct jpeg_upsampler { long dummy; };
 struct jpeg_color_deconverter { long dummy; };
 struct jpeg_color_quantizer { long dummy; };
 #endif /* JPEG_INTERNALS */
 #endif /* INCOMPLETE_TYPES_BROKEN */
 
 
 /*
  * The JPEG library modules define JPEG_INTERNALS before including this file.
  * The internal structure declarations are read only when that is true.
  * Applications using the library should not include jpegint.h, but may wish
  * to include jerror.h.
  */
 
 #ifdef JPEG_INTERNALS
 #include "jpegint.h"            /* fetch private declarations */
 #include "jerror.h"             /* fetch error codes too */
 #endif
 
 #ifdef __cplusplus
 #ifndef DONT_USE_EXTERN_C
 }
 #endif
 #endif
 
 #endif /* JPEGLIB_H */

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