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/*

 * 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 */

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));

};

/* 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.

 */

#ifdef HAVE_PROTOTYPES

#define JPP(arglist)	arglist

#else

#define JPP(arglist)	()

#endif

/* 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.)

 */

#ifdef NEED_SHORT_EXTERNAL_NAMES

#define jpeg_std_error		jStdError

#define jpeg_CreateCompress	jCreaCompress

#define jpeg_CreateDecompress	jCreaDecompress

#define jpeg_destroy_compress	jDestCompress

#define jpeg_destroy_decompress	jDestDecompress

#define jpeg_stdio_dest		jStdDest

#define jpeg_stdio_src		jStdSrc

#define jpeg_set_defaults	jSetDefaults

#define jpeg_set_colorspace	jSetColorspace

#define jpeg_default_colorspace	jDefColorspace

#define jpeg_set_quality	jSetQuality

#define jpeg_set_linear_quality	jSetLQuality

#define jpeg_add_quant_table	jAddQuantTable

#define jpeg_quality_scaling	jQualityScaling

#define jpeg_simple_progression	jSimProgress

#define jpeg_suppress_tables	jSuppressTables

#define jpeg_alloc_quant_table	jAlcQTable

#define jpeg_alloc_huff_table	jAlcHTable

#define jpeg_start_compress	jStrtCompress

#define jpeg_write_scanlines	jWrtScanlines

#define jpeg_finish_compress	jFinCompress

#define jpeg_write_raw_data	jWrtRawData

#define jpeg_write_marker	jWrtMarker

#define jpeg_write_m_header	jWrtMHeader

#define jpeg_write_m_byte	jWrtMByte

#define jpeg_write_tables	jWrtTables

#define jpeg_read_header	jReadHeader

#define jpeg_start_decompress	jStrtDecompress

#define jpeg_read_scanlines	jReadScanlines

#define jpeg_finish_decompress	jFinDecompress

#define jpeg_read_raw_data	jReadRawData

#define jpeg_has_multiple_scans	jHasMultScn

#define jpeg_start_output	jStrtOutput

#define jpeg_finish_output	jFinOutput

#define jpeg_input_complete	jInComplete

#define jpeg_new_colormap	jNewCMap

#define jpeg_consume_input	jConsumeInput

#define jpeg_calc_output_dimensions	jCalcDimensions

#define jpeg_save_markers	jSaveMarkers

#define jpeg_set_marker_processor	jSetMarker

#define jpeg_read_coefficients	jReadCoefs

#define jpeg_write_coefficients	jWrtCoefs

#define jpeg_copy_critical_parameters	jCopyCrit

#define jpeg_abort_compress	jAbrtCompress

#define jpeg_abort_decompress	jAbrtDecompress

#define jpeg_abort		jAbort

#define jpeg_destroy		jDestroy

#define jpeg_resync_to_restart	jResyncRestart

#endif /* NEED_SHORT_EXTERNAL_NAMES */

/* 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 */