libjpeg.h文件

/* * 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. *///jpeg组制定，是jpeg格式较为标准的头文件#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". *///版本号#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 *///DCT系数#define DCTSIZE2    64/* DCTSIZE squared; # of elements in a block */#define NUM_QUANT_TBLS      4/* Quantization tables are numbered 0..3 *///量化表#define NUM_HUFF_TBLS       4/* Huffman tables are numbered 0..3 *///哈夫曼表#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_PERMANENT0/* lasts until master record is destroyed */#define JPOOL_IMAGE1/* lasts until done with image/datastream */#define JPOOL_NUMPOOLS2typedef 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_errorjStdError#define jpeg_CreateCompressjCreaCompress#define jpeg_CreateDecompressjCreaDecompress#define jpeg_destroy_compressjDestCompress#define jpeg_destroy_decompressjDestDecompress#define jpeg_stdio_destjStdDest#define jpeg_stdio_srcjStdSrc#define jpeg_set_defaultsjSetDefaults#define jpeg_set_colorspacejSetColorspace#define jpeg_default_colorspacejDefColorspace#define jpeg_set_qualityjSetQuality#define jpeg_set_linear_qualityjSetLQuality#define jpeg_add_quant_tablejAddQuantTable#define jpeg_quality_scalingjQualityScaling#define jpeg_simple_progressionjSimProgress#define jpeg_suppress_tablesjSuppressTables#define jpeg_alloc_quant_tablejAlcQTable#define jpeg_alloc_huff_tablejAlcHTable#define jpeg_start_compressjStrtCompress#define jpeg_write_scanlinesjWrtScanlines#define jpeg_finish_compressjFinCompress#define jpeg_write_raw_datajWrtRawData#define jpeg_write_markerjWrtMarker#define jpeg_write_m_headerjWrtMHeader#define jpeg_write_m_bytejWrtMByte#define jpeg_write_tablesjWrtTables#define jpeg_read_headerjReadHeader#define jpeg_start_decompressjStrtDecompress#define jpeg_read_scanlinesjReadScanlines#define jpeg_finish_decompressjFinDecompress#define jpeg_read_raw_datajReadRawData#define jpeg_has_multiple_scansjHasMultScn#define jpeg_start_outputjStrtOutput#define jpeg_finish_outputjFinOutput#define jpeg_input_completejInComplete#define jpeg_new_colormapjNewCMap#define jpeg_consume_inputjConsumeInput#define jpeg_calc_output_dimensionsjCalcDimensions#define jpeg_save_markersjSaveMarkers#define jpeg_set_marker_processorjSetMarker#define jpeg_read_coefficientsjReadCoefs#define jpeg_write_coefficientsjWrtCoefs#define jpeg_copy_critical_parametersjCopyCrit#define jpeg_abort_compressjAbrtCompress#define jpeg_abort_decompressjAbrtDecompress#define jpeg_abortjAbort#define jpeg_destroyjDestroy#define jpeg_resync_to_restartjResyncRestart#endif /* NEED_SHORT_EXTERNAL_NAMES *//* Default error-management setup */EXTERN(struct jpeg_error_mgr *) jpeg_std_errorJPP((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_markerJPP((j_compress_ptr cinfo, int marker,     const JOCTET * dataptr, unsigned int datalen));/* Same, but piecemeal. */EXTERN(void) jpeg_write_m_headerJPP((j_compress_ptr cinfo, int marker, unsigned int datalen));EXTERN(void) jpeg_write_m_byteJPP((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_SUSPENDED0 /* Suspended due to lack of input data */#define JPEG_HEADER_OK1 /* Found valid image datastream */#define JPEG_HEADER_TABLES_ONLY2 /* 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_SUSPENDED0    Suspended due to lack of input data */#define JPEG_REACHED_SOS1 /* Reached start of new scan */#define JPEG_REACHED_EOI2 /* Reached end of image */#define JPEG_ROW_COMPLETED3 /* Completed one iMCU row */#define JPEG_SCAN_COMPLETED4 /* 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_markersJPP((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_processorJPP((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_RST00xD0/* RST0 marker code */#define JPEG_EOI0xD9/* EOI marker code */#define JPEG_APP00xE0/* APP0 marker code */#define JPEG_COM0xFE/* 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 */