www.pudn.com > uCOS-uCGUI-FATFs.rar > jpeglib.h, change:2004-08-18,size:44840b


/* 
 * 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 
 
/* 
 * 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 */ 
 
 
/* 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 FAR *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 FAR *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 FAR *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 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. 
   */ 
  JDIMENSION width_in_blocks; 
  JDIMENSION 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) 
   */ 
  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 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 { 
  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 FAR * 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 FAR * data;		/* the data contained in the marker */ 
  /* the marker length word is not counted in data_length or original_length */ 
}; 
 
/* 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 */ 
} 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 */ 
} 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. 
   */ 
 
  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 */ 
   
  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 */ 
  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 */ 
 
  JDIMENSION 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 */ 
   
  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 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; 
}; 
 
 
/* 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 */ 
 
  /* 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 */ 
 
  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 */ 
 
  int min_DCT_scaled_size;	/* smallest DCT_scaled_size of any component */ 
 
  JDIMENSION 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 */ 
 
  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 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; 
}; 
 
 
/* "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 */ 
  JMETHOD(void, error_exit, (j_common_ptr cinfo)); 
  /* Conditionally emit a trace or warning message */ 
  JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level)); 
  /* Routine that actually outputs a trace or error message */ 
  JMETHOD(void, output_message, (j_common_ptr cinfo)); 
  /* Format a message string for the most recent JPEG error or message */ 
  JMETHOD(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 */ 
  JMETHOD(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 { 
  JMETHOD(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 */ 
 
  JMETHOD(void, init_destination, (j_compress_ptr cinfo)); 
  JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo)); 
  JMETHOD(void, term_destination, (j_compress_ptr cinfo)); 
}; 
 
 
/* Data source object for decompression */ 
 
typedef 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 */ 
 
  JMETHOD(void, init_source, (j_decompress_ptr cinfo)); 
  JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo)); 
  JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes)); 
  JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired)); 
  JMETHOD(void, 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; 
 
 
struct jpeg_memory_mgr { 
  /* Method pointers */ 
  JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id, 
				size_t sizeofobject)); 
  JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id, 
				     size_t sizeofobject)); 
  JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id, 
				     JDIMENSION samplesperrow, 
				     JDIMENSION numrows)); 
  JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id, 
				      JDIMENSION blocksperrow, 
				      JDIMENSION numrows)); 
  JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo, 
						  int pool_id, 
						  boolean pre_zero, 
						  JDIMENSION samplesperrow, 
						  JDIMENSION numrows, 
						  JDIMENSION maxaccess)); 
  JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo, 
						  int pool_id, 
						  boolean pre_zero, 
						  JDIMENSION blocksperrow, 
						  JDIMENSION numrows, 
						  JDIMENSION maxaccess)); 
  JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo)); 
  JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo, 
					   jvirt_sarray_ptr ptr, 
					   JDIMENSION start_row, 
					   JDIMENSION num_rows, 
					   boolean writable)); 
  JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo, 
					    jvirt_barray_ptr ptr, 
					    JDIMENSION start_row, 
					    JDIMENSION num_rows, 
					    boolean writable)); 
  JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id)); 
  JMETHOD(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 JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo)); 
 
 
/* Declarations for routines called by application. 
 * The JPP macro hides prototype parameters from compilers that can't cope. 
 * Note JPP requires double parentheses. 
 */ 
 
#define JPP(arglist)	arglist 
 
 
 
/* Default error-management setup */ 
EXTERN(struct jpeg_error_mgr *) jpeg_std_error 
	JPP((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 JPP((j_compress_ptr cinfo, 
				      int version, size_t structsize)); 
EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo, 
					int version, size_t structsize)); 
/* Destruction of JPEG compression objects */ 
EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo)); 
EXTERN(void) jpeg_destroy_decompress JPP((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 JPP((j_compress_ptr cinfo, FILE * outfile)); */ 
/* EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile)); */ 
 
/* Default parameter setup for compression */ 
EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo)); 
/* Compression parameter setup aids */ 
EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo, 
				      J_COLOR_SPACE colorspace)); 
EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo)); 
EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality, 
				   boolean force_baseline)); 
EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo, 
					  int scale_factor, 
					  boolean force_baseline)); 
EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl, 
				       const unsigned int *basic_table, 
				       int scale_factor, 
				       boolean force_baseline)); 
EXTERN(int) jpeg_quality_scaling JPP((int quality)); 
EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo)); 
EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo, 
				       boolean suppress)); 
EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo)); 
EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo)); 
 
/* Main entry points for compression */ 
EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo, 
				      boolean write_all_tables)); 
EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo, 
					     JSAMPARRAY scanlines, 
					     JDIMENSION num_lines)); 
EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo)); 
 
/* Replaces jpeg_write_scanlines when writing raw downsampled data. */ 
EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo, 
					    JSAMPIMAGE data, 
					    JDIMENSION num_lines)); 
 
/* Write a special marker.  See libjpeg.doc concerning safe usage. */ 
EXTERN(void) jpeg_write_marker 
	JPP((j_compress_ptr cinfo, int marker, 
	     const JOCTET * dataptr, unsigned int datalen)); 
/* Same, but piecemeal. */ 
EXTERN(void) jpeg_write_m_header 
	JPP((j_compress_ptr cinfo, int marker, unsigned int datalen)); 
EXTERN(void) jpeg_write_m_byte 
	JPP((j_compress_ptr cinfo, int val)); 
 
/* Alternate compression function: just write an abbreviated table file */ 
EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo)); 
 
/* Decompression startup: read start of JPEG datastream to see what's there */ 
EXTERN(int) jpeg_read_header JPP((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 JPP((j_decompress_ptr cinfo)); 
EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo, 
					    JSAMPARRAY scanlines, 
					    JDIMENSION max_lines)); 
EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo)); 
 
/* Replaces jpeg_read_scanlines when reading raw downsampled data. */ 
EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo, 
					   JSAMPIMAGE data, 
					   JDIMENSION max_lines)); 
 
/* Additional entry points for buffered-image mode. */ 
EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo)); 
EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo, 
				       int scan_number)); 
EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo)); 
EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo)); 
EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo)); 
EXTERN(int) jpeg_consume_input JPP((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) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo)); 
 
/* Control saving of COM and APPn markers into marker_list. */ 
EXTERN(void) jpeg_save_markers 
	JPP((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 
	JPP((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 JPP((j_decompress_ptr cinfo)); 
EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo, 
					  jvirt_barray_ptr * coef_arrays)); 
EXTERN(void) jpeg_copy_critical_parameters JPP((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 JPP((j_compress_ptr cinfo)); 
EXTERN(void) jpeg_abort_decompress JPP((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 JPP((j_common_ptr cinfo)); 
EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo)); 
 
/* Default restart-marker-resync procedure for use by data source modules */ 
EXTERN(boolean) jpeg_resync_to_restart JPP((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 */ 
 
 
/* 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 
 
#endif /* JPEGLIB_H */