text: /*
   * jpeglib.h
   *
   * Copyright (C) 1991-1998, Thomas G. Lane.
   * This file is part of the Independent JPEG Group's software.
   * For conditions of distribution and use, see the accompanying README 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__
  
  #ifndef __BURGER__
  #include <Burger.h>
  #endif
  
  /*
   * 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 __JMORECFG_H__
  #include <jmorecfg.h>		/* seldom changed options */
  #endif
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /* Version ID for the JPEG library.
   * Might be useful for tests like "#if JPEG_LIB_VERSION >= 60".
   */
  
  #define JPEG_LIB_VERSION  62	/* Version 6b */
  
  /* 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.
   */
  
  #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 blocks per MCU */
  #ifndef D_MAX_BLOCKS_IN_MCU
  #define D_MAX_BLOCKS_IN_MCU   10 /* decompressor's limit on blocks per MCU */
  #endif
  
  /* Data structures for images (arrays of samples and of DCT coefficients).
   * On 80x86 machines, the image arrays are too big for near pointers,
   * but the pointer arrays can fit in near memory.
   */
  
  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 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 JQUANT_TBL {
  	/* 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.
  	*/
  	Short 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.)
  	*/
  	Byte sent_table;		/* TRUE when table has been output */
  	Byte Padding[3];		/* Not used */
  } JQUANT_TBL;
  
  /* Huffman coding tables. */
  
  typedef struct JHUFF_TBL {
  	/* These two fields directly represent the contents of a JPEG DHT marker */
  	Byte bits[17];		/* bits[k] = # of symbols with codes of */
  	/* length k bits; bits[0] is unused */
  	Byte 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.)
  	*/
  	Byte sent_table;		/* TRUE when table has been output */
  	Byte Padding[2];		/* Align to longword */
  } JHUFF_TBL;
  
  /* Basic info about one component (color channel). */
  
  typedef struct jpeg_component_info {
  	/* 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 DCT blocks.
  	* 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.
  	*/
  	Word width_in_blocks;
  	Word height_in_blocks;
  	/* Size of a DCT block in samples.  Always DCTSIZE for compression.
  	* For decompression this is the size of the output from one DCT block,
  	* reflecting any scaling we choose to apply during the IDCT step.
  	* Values of 1,2,4,8 are likely to be supported.  Note that different
  	* components may receive different IDCT scalings.
  	*/
  	int DCT_scaled_size;
  	/* 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 decompression, IDCT scaling is included, so
  	* downsampled_width = ceil(image_width * Hi/Hmax * DCT_scaled_size/DCTSIZE)
  	*/
  	Word downsampled_width;	 /* actual width in samples */
  	Word 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.
  	*/
  	Byte component_needed;	/* do we need the value of this component? */
  	Byte Padding[3];		/* Not used */
  	
  	/* 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 blocks per MCU, horizontally */
  	int MCU_height;		/* number of blocks per MCU, vertically */
  	int MCU_blocks;		/* MCU_width * MCU_height */
  	int MCU_sample_width;		/* MCU width in samples, MCU_width*DCT_scaled_size */
  	int last_col_width;		/* # of non-dummy blocks across in last MCU */
  	int last_row_height;		/* # of non-dummy blocks 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 jpeg_scan_info {
  	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 */
  	int Ah, Al;			/* progressive JPEG successive approx. parms */
  } 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;
  
  typedef struct jpeg_marker_struct {
  	jpeg_saved_marker_ptr next;	/* next in list, or NULL */
  	Byte marker;				/* marker code: JPEG_COM, or JPEG_APP0+n */
  	Byte Padding[3];
  	Word original_length;		/* # bytes of data in the file */
  	Word data_length;			/* # bytes of data saved at data[] */
  	Byte * data;				/* the data contained in the marker */
  	/* the marker length word is not counted in data_length or original_length */
  } jpeg_marker_struct;
  
  /* Known color spaces. */
  
  typedef enum {
  	JCS_UNKNOWN,		/* error/unspecified */
  	JCS_GRAYSCALE,		/* monochrome */
  	JCS_RGB,			/* red/green/blue */
  	JCS_YCbCr,			/* Y/Cb/Cr (also known as YUV) */
  	JCS_CMYK,			/* C/M/Y/K */
  	JCS_YCCK,			/* Y/Cb/Cr/K */
  	JCS_MAXINT=0x7FFFFFFF	/* Ensure ENUM is 32 bit */
  } J_COLOR_SPACE;
  
  /* DCT/IDCT algorithm options. */
  
  typedef enum {
  	JDCT_ISLOW,			/* slow but accurate integer algorithm */
  	JDCT_IFAST,			/* faster, less accurate integer method */
  	JDCT_FLOAT,			/* floating-point: accurate, fast on fast HW */
  	JDCT_MAXINT=0x7FFFFFFF	/* Ensure ENUM is 32 bit */
  } 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 */
  	JDITHER_MAXINT=0x7FFFFFFF	/* Ensure ENUM is 32 bit */
  } 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 */\
    Byte is_decompressor;	/* So common code can tell which is which */\
    Byte PaddingX[3];	/* Not used */\
    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.
   */
  typedef 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++.)
  	*/
  } jpeg_common_struct;
  
  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 */
  
  typedef struct jpeg_compress_struct {
  	jpeg_common_fields;		/* Fields shared with jpeg_decompress_struct */
  
  	double input_gamma;		/* image gamma of input image */
  
  	/* 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().
  	*/
  
  	Word image_width;	/* input image width */
  	Word image_height;	/* input image height */
  	int input_components;		/* # of color components in input image */
  	J_COLOR_SPACE in_color_space;	/* colorspace 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.
  	*/
  
  	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];
  	/* 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 */
  
  	Byte arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
  	Byte arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
  	Byte 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.
  	*/
  
  	Byte raw_data_in;		/* TRUE=caller supplies downsampled data */
  	Byte arith_code;		/* TRUE=arithmetic coding, FALSE=Huffman */
  	Byte optimize_coding;	/* TRUE=optimize entropy encoding parms */
  	Byte CCIR601_sampling;	/* TRUE=first samples are cosited */
  	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).
  	*/
  	Word 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. */
  
  	Byte write_JFIF_header;	/* should a JFIF marker be written? */
  	Byte JFIF_major_version;	/* What to write for the JFIF version number */
  	Byte 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. */
  	Byte density_unit;		/* JFIF code for pixel size units */
  	Short X_density;		/* Horizontal pixel density */
  	Short Y_density;		/* Vertical pixel density */
  
  	/* 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)".
  	*/
  
  	Word next_scanline;	/* 0 .. image_height-1  */
  
  	Byte write_Adobe_marker;	/* should an Adobe marker be written? */
  
  	/* Remaining fields are known throughout compressor, but generally
  	* should not be touched by a surrounding application.
  	*/
  
  	/*
  	* These fields are computed during compression startup
  	*/
  	Byte progressive_mode;	/* TRUE if scan script uses progressive mode */
  	Byte Padding1[2];		/* Align to long */
  	int max_h_samp_factor;	/* largest h_samp_factor */
  	int max_v_samp_factor;	/* largest v_samp_factor */
  
  	Word total_iMCU_rows;	/* # of iMCU rows to be input to coef ctlr */
  	/* The coefficient controller receives data in units of MCU rows as defined
  	* for fully interleaved scans (whether the JPEG file is interleaved or not).
  	* There are v_samp_factor * DCTSIZE sample rows of each component in an
  	* "iMCU" (interleaved MCU) row.
  	*/
  
  	/*
  	* 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 */
  
  	Word MCUs_per_row;	/* # of MCUs across the image */
  	Word MCU_rows_in_scan;	/* # of MCU rows in the image */
  
  	int blocks_in_MCU;		/* # of DCT blocks per MCU */
  	int MCU_membership[C_MAX_BLOCKS_IN_MCU];
  	/* MCU_membership[i] is index in cur_comp_info of component owning */
  	/* i'th block in an MCU */
  
  	int Ss, Se, Ah, Al;		/* progressive JPEG parameters for scan */
  
  	/*
  	* 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;
  } jpeg_compress_struct;
  
  /* Master record for a decompression instance */
  
  typedef struct jpeg_decompress_struct {
  	jpeg_common_fields;		/* Fields shared with jpeg_compress_struct */
  	double output_gamma;		/* image gamma wanted in output */
  	
  	/* 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. */
  
  	Word image_width;	/* nominal image width (from SOF marker) */
  	Word 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 */
  
  	Word scale_num, scale_denom; /* fraction by which to scale image */
  
  	Byte buffered_image;	/* TRUE=multiple output passes */
  	Byte raw_data_out;		/* TRUE=downsampled data wanted */
  	Byte do_fancy_upsampling;	/* TRUE=apply fancy upsampling */
  	Byte do_block_smoothing;	/* TRUE=apply interblock smoothing */
  
  	J_DCT_METHOD dct_method;	/* IDCT algorithm selector */
  
  	/* the following are ignored if not quantize_colors: */
  	J_DITHER_MODE dither_mode;	/* type of color dithering to use */
  	int desired_number_of_colors;	/* max # colors to use in created colormap */
  
  	Byte two_pass_quantize;	/* TRUE=use two-pass color quantization */
  	Byte quantize_colors;	/* TRUE=colormapped output wanted */
  	/* these are significant only in buffered-image mode: */
  	Byte enable_1pass_quant;	/* enable future use of 1-pass quantizer */
  	Byte enable_external_quant;/* enable future use of external colormap */
  
  	/* 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().
  	*/
  
  	Word output_width;	/* scaled image width */
  	Word 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 */
  
  	/* 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)".
  	*/
  	Word 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 */
  	Word 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 */
  	Word 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 */
  
  	Byte enable_2pass_quant;	/* enable future use of 2-pass quantizer */
  	Byte progressive_mode;	/* TRUE if SOFn specifies progressive mode */
  	Byte arith_code;		/* TRUE=arithmetic coding, FALSE=Huffman */
  	Byte saw_JFIF_marker;	/* TRUE iff a JFIF APP0 marker was found */
  
  	Byte arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
  	Byte arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
  	Byte arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
  
  	Word restart_interval; /* MCUs per restart interval, or 0 for no restart */
  
  	/* These fields record data obtained from optional markers recognized by
  	* the JPEG library.
  	*/
  	/* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
  	Byte JFIF_major_version;	/* JFIF version number */
  	Byte JFIF_minor_version;
  	Byte density_unit;		/* JFIF code for pixel size units */
  	Byte saw_Adobe_marker;	/* TRUE iff an Adobe APP14 marker was found */
  
  	Short X_density;		/* Horizontal pixel density */
  	Short Y_density;		/* Vertical pixel density */
  	
  	Byte Adobe_transform;	/* Color transform code from Adobe marker */
  	Byte CCIR601_sampling;	/* TRUE=first samples are cosited */
  	Byte Padding1[2];
  	
  	/* 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 */
  
  	int min_DCT_scaled_size;	/* smallest DCT_scaled_size of any component */
  
  	Word total_iMCU_rows;	/* # of iMCU rows in image */
  	/* The coefficient 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.  We define an iMCU row as v_samp_factor DCT block
  	* rows of each component.  Therefore, the IDCT output contains
  	* v_samp_factor*DCT_scaled_size sample rows of a component per iMCU row.
  	*/
  
  	JSAMPLE * sample_range_limit; /* table for fast range-limiting */
  
  	/*
  	* 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 */
  
  	Word MCUs_per_row;	/* # of MCUs across the image */
  	Word MCU_rows_in_scan;	/* # of MCU rows in the image */
  
  	int blocks_in_MCU;		/* # of DCT blocks per MCU */
  	int MCU_membership[D_MAX_BLOCKS_IN_MCU];
  	/* MCU_membership[i] is index in cur_comp_info of component owning */
  	/* i'th block in an MCU */
  
  	int Ss, Se, Ah, Al;		/* progressive JPEG parameters for scan */
  
  	/* 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;
  } jpeg_decompress_struct;
  
  
  /* "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 */
  
  typedef struct jpeg_error_mgr {
  	/* Error exit handler: does not return to caller */
  	void(FASTCALL *error_exit)(j_common_ptr cinfo);
  	/* Conditionally emit a trace or warning message */
  	void(FASTCALL *emit_message)(j_common_ptr cinfo, int msg_level);
  	/* Routine that actually outputs a trace or error message */
  	void(FASTCALL *output_message)(j_common_ptr cinfo);
  	/* Format a message string for the most recent JPEG error or message */
  	void(FASTCALL *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(FASTCALL *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 */
  } jpeg_error_mgr;
  
  
  /* Progress monitor object */
  
  typedef struct jpeg_progress_mgr {
  	void(FASTCALL *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 */
  } jpeg_progress_mgr;
  
  
  /* Data destination object for compression */
  
  typedef struct jpeg_destination_mgr {
  	Byte * next_output_byte;	/* => next byte to write in buffer */
  	long free_in_buffer;		/* # of byte spaces remaining in buffer */
  
  	void(FASTCALL *init_destination)(j_compress_ptr cinfo);
  	Byte(FASTCALL *empty_output_buffer)(j_compress_ptr cinfo);
  	void(FASTCALL *term_destination)(j_compress_ptr cinfo);
  } jpeg_destination_mgr;
  
  /* Data source object for decompression */
  
  typedef struct jpeg_source_mgr {
  	const Byte * next_input_byte; /* => next byte to read from buffer */
  	long bytes_in_buffer;	/* # of bytes remaining in buffer */
  
  	void(FASTCALL *init_source)(j_decompress_ptr cinfo);
  	Byte(FASTCALL *fill_input_buffer)(j_decompress_ptr cinfo);
  	void(FASTCALL *skip_input_data)(j_decompress_ptr cinfo, long num_bytes);
  	Byte(FASTCALL *resync_to_restart)(j_decompress_ptr cinfo, int desired);
  	void(FASTCALL *term_source)(j_decompress_ptr cinfo);
  } jpeg_source_mgr;
  
  
  /* 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;
  
  typedef struct jpeg_memory_mgr {
  	/* Method pointers */
  	void *(FASTCALL *alloc_small)(j_common_ptr cinfo, int pool_id,long sizeofobject);
  	void *(FASTCALL *alloc_large)(j_common_ptr cinfo, int pool_id,long sizeofobject);
  	JSAMPARRAY(FASTCALL *alloc_sarray)(j_common_ptr cinfo, int pool_id,Word samplesperrow,Word numrows);
  	JBLOCKARRAY(FASTCALL *alloc_barray)(j_common_ptr cinfo, int pool_id,Word blocksperrow,Word numrows);
  	jvirt_sarray_ptr(FASTCALL *request_virt_sarray)(j_common_ptr cinfo,int pool_id,Byte pre_zero,Word samplesperrow,Word numrows,Word maxaccess);
  	jvirt_barray_ptr (FASTCALL *request_virt_barray)(j_common_ptr cinfo,int pool_id,Byte pre_zero,Word blocksperrow,Word numrows,Word maxaccess);
  	void (FASTCALL *realize_virt_arrays)(j_common_ptr cinfo);
  	JSAMPARRAY(FASTCALL *access_virt_sarray)(j_common_ptr cinfo,jvirt_sarray_ptr ptr,Word start_row,Word num_rows,Byte writable);
  	JBLOCKARRAY(FASTCALL *access_virt_barray)(j_common_ptr cinfo,jvirt_barray_ptr ptr,Word start_row,Word num_rows,Byte writable);
  	void(FASTCALL *free_pool)(j_common_ptr cinfo, int pool_id);
  	void(FASTCALL *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;
  } jpeg_memory_mgr;
  
  
  /* Routine signature for application-supplied marker processing methods.
   * Need not pass marker code since it is stored in cinfo->unread_marker.
   */
  typedef Byte (FASTCALL *jpeg_marker_parser_method)(j_decompress_ptr cinfo);
  
  /* Short forms of external names for systems with brain-damaged linkers.
   * We shorten external names to be unique in the first six letters, which
   * is good enough for all known systems.
   * (If your compiler itself needs names to be unique in less than 15 
   * characters, you are out of luck.  Get a better compiler.)
   */
  
  /* Default error-management setup */
  extern struct jpeg_error_mgr * FASTCALL 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,(long) sizeof(struct jpeg_compress_struct))
  #define jpeg_create_decompress(cinfo) \
      jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION,(long) sizeof(struct jpeg_decompress_struct))
  extern void FASTCALL jpeg_CreateCompress (j_compress_ptr cinfo,int version, long structsize);
  extern void FASTCALL jpeg_CreateDecompress (j_decompress_ptr cinfo,int version, long structsize);
  
  /* Destruction of JPEG compression objects */
  extern void FASTCALL jpeg_destroy_compress (j_compress_ptr cinfo);
  extern void FASTCALL 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 FASTCALL jpeg_stdio_dest (j_compress_ptr cinfo, FILE * outfile);
  extern void FASTCALL jpeg_stdio_src (j_decompress_ptr cinfo, FILE * infile);
  
  /* Default parameter setup for compression */
  extern void FASTCALL jpeg_set_defaults(j_compress_ptr cinfo);
  /* Compression parameter setup aids */
  extern void FASTCALL jpeg_set_colorspace(j_compress_ptr cinfo,J_COLOR_SPACE colorspace);
  extern void FASTCALL jpeg_default_colorspace (j_compress_ptr cinfo);
  extern void FASTCALL jpeg_set_quality (j_compress_ptr cinfo, int quality,Byte force_baseline);
  extern void FASTCALL jpeg_set_linear_quality (j_compress_ptr cinfo,int scale_factor,Byte force_baseline);
  extern void FASTCALL jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl,const Word *basic_table,int scale_factor,Byte force_baseline);
  extern int FASTCALL jpeg_quality_scaling (int quality);
  extern void FASTCALL jpeg_simple_progression (j_compress_ptr cinfo);
  extern void FASTCALL jpeg_suppress_tables (j_compress_ptr cinfo,Byte suppress);
  extern JQUANT_TBL * FASTCALL jpeg_alloc_quant_table(j_common_ptr cinfo);
  extern JHUFF_TBL * FASTCALL jpeg_alloc_huff_table (j_common_ptr cinfo);
  
  /* Main entry points for compression */
  extern void FASTCALL jpeg_start_compress (j_compress_ptr cinfo,Byte write_all_tables);
  extern Word FASTCALL jpeg_write_scanlines (j_compress_ptr cinfo,JSAMPARRAY scanlines,Word num_lines);
  extern void FASTCALL jpeg_finish_compress(j_compress_ptr cinfo);
  
  /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
  extern Word FASTCALL jpeg_write_raw_data(j_compress_ptr cinfo,JSAMPIMAGE data,Word num_lines);
  
  /* Write a special marker.  See libjpeg.doc concerning safe usage. */
  extern void FASTCALL jpeg_write_marker(j_compress_ptr cinfo, int marker,const Byte * dataptr, Word datalen);
  /* Same, but piecemeal. */
  extern void FASTCALL jpeg_write_m_header(j_compress_ptr cinfo, int marker, Word datalen);
  extern void FASTCALL jpeg_write_m_byte(j_compress_ptr cinfo, int val);
  
  /* Alternate compression function: just write an abbreviated table file */
  extern void FASTCALL jpeg_write_tables(j_compress_ptr cinfo);
  
  /* Decompression startup: read start of JPEG datastream to see what's there */
  extern int jpeg_read_header(j_decompress_ptr cinfo,Byte 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 Byte FASTCALL jpeg_start_decompress(j_decompress_ptr cinfo);
  extern Word FASTCALL jpeg_read_scanlines(j_decompress_ptr cinfo,JSAMPARRAY scanlines,Word max_lines);
  extern Byte FASTCALL jpeg_finish_decompress (j_decompress_ptr cinfo);
  
  /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
  extern Word FASTCALL jpeg_read_raw_data (j_decompress_ptr cinfo,JSAMPIMAGE data,Word max_lines);
  
  /* Additional entry points for buffered-image mode. */
  extern Byte FASTCALL jpeg_has_multiple_scans (j_decompress_ptr cinfo);
  extern Byte FASTCALL jpeg_start_output (j_decompress_ptr cinfo,int scan_number);
  extern Byte FASTCALL jpeg_finish_output (j_decompress_ptr cinfo);
  extern Byte FASTCALL jpeg_input_complete (j_decompress_ptr cinfo);
  extern void FASTCALL jpeg_new_colormap (j_decompress_ptr cinfo);
  extern int FASTCALL 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. */
  extern void FASTCALL jpeg_calc_output_dimensions (j_decompress_ptr cinfo);
  
  /* Control saving of COM and APPn markers into marker_list. */
  extern void FASTCALL 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 FASTCALL 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 * FASTCALL jpeg_read_coefficients(j_decompress_ptr cinfo);
  extern void FASTCALL jpeg_write_coefficients(j_compress_ptr cinfo,jvirt_barray_ptr * coef_arrays);
  extern void FASTCALL 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 FASTCALL jpeg_abort_compress (j_compress_ptr cinfo);
  extern void FASTCALL 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 FASTCALL jpeg_abort (j_common_ptr cinfo);
  extern void FASTCALL jpeg_destroy(j_common_ptr cinfo);
  
  /* Default restart-marker-resync procedure for use by data source modules */
  extern Byte FASTCALL jpeg_resync_to_restart (j_decompress_ptr cinfo,int desired);
  
  /* 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 */
  
  /*
   * 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 __cplusplus
  }
  #endif
  
  #ifdef JPEG_INTERNALS
  #ifndef __JPEGINT_H__
  #include "jpegint.h"		/* fetch private declarations */
  #endif
  
  #ifndef __JERROR_H__
  #include <jerror.h>		/* fetch error codes too */
  #endif
  #endif
  
  #endif /* JPEGLIB_H */
  