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 /*

  * jpeglib.h

  *

  * This file was part of the Independent JPEG Group's software:

  * Copyright (C) 1991-1998, Thomas G. Lane.

  * Modified 2002-2009 by Guido Vollbeding.

  * Modifications:

  * Copyright (C) 2009-2011, 2013, D. R. Commander.

  * 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 */

 #ifdef __cplusplus

 #ifndef DONT_USE_EXTERN_C

 extern "C" {

 #endif

 #endif

 /* Various constants determining the sizes of things.

  * All of these are specified by the JPEG standard, so don't change them

  * if you want to be compatible.

  */

 #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.

    */

 #if JPEG_LIB_VERSION >= 70

   int DCT_h_scaled_size;

   int DCT_v_scaled_size;

 #else

   int DCT_scaled_size;

 #endif

   /* The downsampled dimensions are the component's actual, unpadded number

    * of samples at the main buffer (preprocessing/compression interface), thus

    * downsampled_width = ceil(image_width * Hi/Hmax)

    * and similarly for height.  For decompression, IDCT scaling is included, so

    * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]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_[h_]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. */

 #define JCS_EXTENSIONS 1

 #define JCS_ALPHA_EXTENSIONS 1

 typedef enum {

 	JCS_UNKNOWN,		/* error/unspecified */

 	JCS_GRAYSCALE,		/* monochrome */

 	JCS_RGB,		/* red/green/blue as specified by the RGB_RED, RGB_GREEN,

 				   RGB_BLUE, and RGB_PIXELSIZE macros */

 	JCS_YCbCr,		/* Y/Cb/Cr (also known as YUV) */

 	JCS_CMYK,		/* C/M/Y/K */

 	JCS_YCCK,		/* Y/Cb/Cr/K */

 	JCS_EXT_RGB,		/* red/green/blue */

 	JCS_EXT_RGBX,		/* red/green/blue/x */

 	JCS_EXT_BGR,		/* blue/green/red */

 	JCS_EXT_BGRX,		/* blue/green/red/x */

 	JCS_EXT_XBGR,		/* x/blue/green/red */

 	JCS_EXT_XRGB,		/* x/red/green/blue */

 	/* When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX,

 	   JCS_EXT_XBGR, or JCS_EXT_XRGB during decompression, the X byte is

 	   undefined, and in order to ensure the best performance,

 	   libjpeg-turbo can set that byte to whatever value it wishes.  Use

 	   the following colorspace constants to ensure that the X byte is set

 	   to 0xFF, so that it can be interpreted as an opaque alpha

 	   channel. */

 	JCS_EXT_RGBA,		/* red/green/blue/alpha */

 	JCS_EXT_BGRA,		/* blue/green/red/alpha */

 	JCS_EXT_ABGR,		/* alpha/blue/green/red */

 	JCS_EXT_ARGB		/* alpha/red/green/blue */

 } 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.

    */

 #if JPEG_LIB_VERSION >= 70

   unsigned int scale_num, scale_denom; /* fraction by which to scale image */

   JDIMENSION jpeg_width;	/* scaled JPEG image width */

   JDIMENSION jpeg_height;	/* scaled JPEG image height */

   /* Dimensions of actual JPEG image that will be written to file,

    * derived from input dimensions by scaling factors above.

    * These fields are computed by jpeg_start_compress().

    * You can also use jpeg_calc_jpeg_dimensions() to determine these values

    * in advance of calling jpeg_start_compress().

    */

 #endif

   int data_precision;		/* bits of precision in image data */

   int num_components;		/* # of color components in JPEG image */

   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */

   jpeg_component_info * comp_info;

   /* comp_info[i] describes component that appears i'th in SOF */

   JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];

 #if JPEG_LIB_VERSION >= 70

   int q_scale_factor[NUM_QUANT_TBLS];

 #endif

   /* ptrs to coefficient quantization tables, or NULL if not defined,

    * and corresponding scale factors (percentage, initialized 100).

    */

   JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];

   JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];

   /* ptrs to Huffman coding tables, or NULL if not defined */

   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */

   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */

   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */

   int num_scans;		/* # of entries in scan_info array */

   const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */

   /* The default value of scan_info is NULL, which causes a single-scan

    * sequential JPEG file to be emitted.  To create a multi-scan file,

    * set num_scans and scan_info to point to an array of scan definitions.

    */

   boolean raw_data_in;		/* TRUE=caller supplies downsampled data */

   boolean arith_code;		/* TRUE=arithmetic coding, FALSE=Huffman */

   boolean optimize_coding;	/* TRUE=optimize entropy encoding parms */

   boolean CCIR601_sampling;	/* TRUE=first samples are cosited */

 #if JPEG_LIB_VERSION >= 70

   boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */

 #endif

   int smoothing_factor;		/* 1..100, or 0 for no input smoothing */

   J_DCT_METHOD dct_method;	/* DCT algorithm selector */

   /* The restart interval can be specified in absolute MCUs by setting

    * restart_interval, or in MCU rows by setting restart_in_rows

    * (in which case the correct restart_interval will be figured

    * for each scan).

    */

   unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */

   int restart_in_rows;		/* if > 0, MCU rows per restart interval */

   /* Parameters controlling emission of special markers. */

   boolean write_JFIF_header;	/* should a JFIF marker be written? */

   UINT8 JFIF_major_version;	/* What to write for the JFIF version number */

   UINT8 JFIF_minor_version;

   /* These three values are not used by the JPEG code, merely copied */

   /* into the JFIF APP0 marker.  density_unit can be 0 for unknown, */

   /* 1 for dots/inch, or 2 for dots/cm.  Note that the pixel aspect */

   /* ratio is defined by X_density/Y_density even when density_unit=0. */

   UINT8 density_unit;		/* JFIF code for pixel size units */

   UINT16 X_density;		/* Horizontal pixel density */

   UINT16 Y_density;		/* Vertical pixel density */

   boolean write_Adobe_marker;	/* should an Adobe marker be written? */

   /* State variable: index of next scanline to be written to

    * jpeg_write_scanlines().  Application may use this to control its

    * processing loop, e.g., "while (next_scanline < image_height)".

    */

   JDIMENSION next_scanline;	/* 0 .. image_height-1  */

   /* Remaining fields are known throughout compressor, but generally

    * should not be touched by a surrounding application.

    */

   /*

    * These fields are computed during compression startup

    */

   boolean progressive_mode;	/* TRUE if scan script uses progressive mode */

   int max_h_samp_factor;	/* largest h_samp_factor */

   int max_v_samp_factor;	/* largest v_samp_factor */

 #if JPEG_LIB_VERSION >= 70

   int min_DCT_h_scaled_size;	/* smallest DCT_h_scaled_size of any component */

   int min_DCT_v_scaled_size;	/* smallest DCT_v_scaled_size of any component */

 #endif

   JDIMENSION total_iMCU_rows;	/* # of iMCU rows to be input to 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 */

 #if JPEG_LIB_VERSION >= 80

   int block_size;		/* the basic DCT block size: 1..16 */

   const int * natural_order;	/* natural-order position array */

   int lim_Se;			/* min( Se, DCTSIZE2-1 ) */

 #endif

   /*

    * Links to compression subobjects (methods and private variables of modules)

    */

   struct jpeg_comp_master * master;

   struct jpeg_c_main_controller * main;

   struct jpeg_c_prep_controller * prep;

   struct jpeg_c_coef_controller * coef;

   struct jpeg_marker_writer * marker;

   struct jpeg_color_converter * cconvert;

   struct jpeg_downsampler * downsample;

   struct jpeg_forward_dct * fdct;

   struct jpeg_entropy_encoder * entropy;

   jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */

   int script_space_size;

 };

 /* Master record for a decompression instance */

 struct jpeg_decompress_struct {

   jpeg_common_fields;		/* Fields shared with jpeg_compress_struct */

   /* Source of compressed data */

   struct jpeg_source_mgr * src;

   /* Basic description of image --- filled in by jpeg_read_header(). */

   /* Application may inspect these values to decide how to process image. */

   JDIMENSION image_width;	/* nominal image width (from SOF marker) */

   JDIMENSION image_height;	/* nominal image height */

   int num_components;		/* # of color components in JPEG image */

   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */

   /* Decompression processing parameters --- these fields must be set before

    * calling jpeg_start_decompress().  Note that jpeg_read_header() initializes

    * them to default values.

    */

   J_COLOR_SPACE out_color_space; /* colorspace for output */

   unsigned int scale_num, scale_denom; /* fraction by which to scale image */

   double output_gamma;		/* image gamma wanted in output */

   boolean buffered_image;	/* TRUE=multiple output passes */

   boolean raw_data_out;		/* TRUE=downsampled data wanted */

   J_DCT_METHOD dct_method;	/* IDCT algorithm selector */

   boolean do_fancy_upsampling;	/* TRUE=apply fancy upsampling */

   boolean do_block_smoothing;	/* TRUE=apply interblock smoothing */

   boolean quantize_colors;	/* TRUE=colormapped output wanted */

   /* the following are ignored if not quantize_colors: */

   J_DITHER_MODE dither_mode;	/* type of color dithering to use */

   boolean two_pass_quantize;	/* TRUE=use two-pass color quantization */

   int desired_number_of_colors;	/* max # colors to use in created colormap */

   /* these are significant only in buffered-image mode: */

   boolean enable_1pass_quant;	/* enable future use of 1-pass quantizer */

   boolean enable_external_quant;/* enable future use of external colormap */

   boolean enable_2pass_quant;	/* enable future use of 2-pass quantizer */

   /* Description of actual output image that will be returned to application.

    * These fields are computed by jpeg_start_decompress().

    * You can also use jpeg_calc_output_dimensions() to determine these values

    * in advance of calling jpeg_start_decompress().

    */

   JDIMENSION output_width;	/* scaled image width */

   JDIMENSION output_height;	/* scaled image height */

   int out_color_components;	/* # of color components in out_color_space */

   int output_components;	/* # of color components returned */

   /* output_components is 1 (a colormap index) when quantizing colors;

    * otherwise it equals out_color_components.

    */

   int rec_outbuf_height;	/* min recommended height of scanline buffer */

   /* If the buffer passed to jpeg_read_scanlines() is less than this many rows

    * high, space and time will be wasted due to unnecessary data copying.

    * Usually rec_outbuf_height will be 1 or 2, at most 4.

    */

   /* When quantizing colors, the output colormap is described by these fields.

    * The application can supply a colormap by setting colormap non-NULL before

    * calling jpeg_start_decompress; otherwise a colormap is created during

    * jpeg_start_decompress or jpeg_start_output.

    * The map has out_color_components rows and actual_number_of_colors columns.

    */

   int actual_number_of_colors;	/* number of entries in use */

   JSAMPARRAY colormap;		/* The color map as a 2-D pixel array */

   /* State variables: these variables indicate the progress of decompression.

    * The application may examine these but must not modify them.

    */

   /* Row index of next scanline to be read from jpeg_read_scanlines().

    * Application may use this to control its processing loop, e.g.,

    * "while (output_scanline < output_height)".

    */

   JDIMENSION output_scanline;	/* 0 .. output_height-1  */

   /* Current input scan number and number of iMCU rows completed in scan.

    * These indicate the progress of the decompressor input side.

    */

   int input_scan_number;	/* Number of SOS markers seen so far */

   JDIMENSION input_iMCU_row;	/* Number of iMCU rows completed */

   /* The "output scan number" is the notional scan being displayed by the

    * output side.  The decompressor will not allow output scan/row number

    * to get ahead of input scan/row, but it can fall arbitrarily far behind.

    */

   int output_scan_number;	/* Nominal scan number being displayed */

   JDIMENSION output_iMCU_row;	/* Number of iMCU rows read */

   /* Current progression status.  coef_bits[c][i] indicates the precision

    * with which component c's DCT coefficient i (in zigzag order) is known.

    * It is -1 when no data has yet been received, otherwise it is the point

    * transform (shift) value for the most recent scan of the coefficient

    * (thus, 0 at completion of the progression).

    * This pointer is NULL when reading a non-progressive file.

    */

   int (*coef_bits)[DCTSIZE2];	/* -1 or current Al value for each coef */

   /* Internal JPEG parameters --- the application usually need not look at

    * these fields.  Note that the decompressor output side may not use

    * any parameters that can change between scans.

    */

   /* Quantization and Huffman tables are carried forward across input

    * datastreams when processing abbreviated JPEG datastreams.

    */

   JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];

   /* ptrs to coefficient quantization tables, or NULL if not defined */

   JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];

   JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];

   /* ptrs to Huffman coding tables, or NULL if not defined */

   /* These parameters are never carried across datastreams, since they

    * are given in SOF/SOS markers or defined to be reset by SOI.

    */

   int data_precision;		/* bits of precision in image data */

   jpeg_component_info * comp_info;

   /* comp_info[i] describes component that appears i'th in SOF */

 #if JPEG_LIB_VERSION >= 80

   boolean is_baseline;		/* TRUE if Baseline SOF0 encountered */

 #endif

   boolean progressive_mode;	/* TRUE if SOFn specifies progressive mode */

   boolean arith_code;		/* TRUE=arithmetic coding, FALSE=Huffman */

   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */

   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */

   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */

   unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */

   /* These fields record data obtained from optional markers recognized by

    * the JPEG library.

    */

   boolean saw_JFIF_marker;	/* TRUE iff a JFIF APP0 marker was found */

   /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */

   UINT8 JFIF_major_version;	/* JFIF version number */

   UINT8 JFIF_minor_version;

   UINT8 density_unit;		/* JFIF code for pixel size units */

   UINT16 X_density;		/* Horizontal pixel density */

   UINT16 Y_density;		/* Vertical pixel density */

   boolean saw_Adobe_marker;	/* TRUE iff an Adobe APP14 marker was found */

   UINT8 Adobe_transform;	/* Color transform code from Adobe marker */

   boolean CCIR601_sampling;	/* TRUE=first samples are cosited */

   /* Aside from the specific data retained from APPn markers known to the

    * library, the uninterpreted contents of any or all APPn and COM markers

    * can be saved in a list for examination by the application.

    */

   jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */

   /* Remaining fields are known throughout decompressor, but generally

    * should not be touched by a surrounding application.

    */

   /*

    * These fields are computed during decompression startup

    */

   int max_h_samp_factor;	/* largest h_samp_factor */

   int max_v_samp_factor;	/* largest v_samp_factor */

 #if JPEG_LIB_VERSION >= 70

   int min_DCT_h_scaled_size;	/* smallest DCT_h_scaled_size of any component */

   int min_DCT_v_scaled_size;	/* smallest DCT_v_scaled_size of any component */

 #else

   int min_DCT_scaled_size;	/* smallest DCT_scaled_size of any component */

 #endif

   JDIMENSION total_iMCU_rows;	/* # of iMCU rows in image */

   /* The coefficient 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_[v_]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 */

 #if JPEG_LIB_VERSION >= 80

   /* These fields are derived from Se of first SOS marker.

    */

   int block_size;		/* the basic DCT block size: 1..16 */

   const int * natural_order; /* natural-order position array for entropy decode */

   int lim_Se;			/* min( Se, DCTSIZE2-1 ) for entropy decode */

 #endif

   /* This field is shared between entropy decoder and marker parser.

    * It is either zero or the code of a JPEG marker that has been

    * read from the data source, but has not yet been processed.

    */

   int unread_marker;

   /*

    * Links to decompression subobjects (methods, private variables of modules)

    */

   struct jpeg_decomp_master * master;

   struct jpeg_d_main_controller * main;

   struct jpeg_d_coef_controller * coef;

   struct jpeg_d_post_controller * post;

   struct jpeg_input_controller * inputctl;

   struct jpeg_marker_reader * marker;

   struct jpeg_entropy_decoder * entropy;

   struct jpeg_inverse_dct * idct;

   struct jpeg_upsampler * upsample;

   struct jpeg_color_deconverter * cconvert;

   struct jpeg_color_quantizer * cquantize;

 };

 /* "Object" declarations for JPEG modules that may be supplied or called

  * directly by the surrounding application.

  * As with all objects in the JPEG library, these structs only define the

  * publicly visible methods and state variables of a module.  Additional

  * private fields may exist after the public ones.

  */

 /* Error handler object */

 struct jpeg_error_mgr {

   /* Error exit handler: does not return to caller */

   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

 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)

 #define jpeg_mem_dest		jMemDest

 #define jpeg_mem_src		jMemSrc

 #endif

 #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

 #if JPEG_LIB_VERSION >= 70

 #define jpeg_default_qtables	jDefQTables

 #endif

 #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

 #if JPEG_LIB_VERSION >= 70

 #define jpeg_calc_jpeg_dimensions	jCjpegDimensions

 #endif

 #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

 #if JPEG_LIB_VERSION >= 80

 #define jpeg_core_output_dimensions	jCoreDimensions

 #endif

 #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));

 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)

 /* Data source and destination managers: memory buffers. */

 EXTERN(void) jpeg_mem_dest JPP((j_compress_ptr cinfo,

 			       unsigned char ** outbuffer,

 			       unsigned long * outsize));

 EXTERN(void) jpeg_mem_src JPP((j_decompress_ptr cinfo,

 			      unsigned char * inbuffer,

 			      unsigned long insize));

 #endif

 /* 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));

 #if JPEG_LIB_VERSION >= 70

 EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo,

 				       boolean force_baseline));

 #endif

 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));

 #if JPEG_LIB_VERSION >= 70

 /* Precalculate JPEG dimensions for current compression parameters. */

 EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo));

 #endif

 /* 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.txt 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. */

 #if JPEG_LIB_VERSION >= 80

 EXTERN(void) jpeg_core_output_dimensions JPP((j_decompress_ptr cinfo));

 #endif

 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

 #ifdef __cplusplus

 #ifndef DONT_USE_EXTERN_C

 }

 #endif

 #endif

 #endif /* JPEGLIB_H */