The Tor Browser: media/libjpeg/jpeglib.h@b8a032363ba2 (annotated)

media/libjpeg/jpeglib.h@b8a032363ba2 (annotated)

media/libjpeg/jpeglib.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /*
  * 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 */

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media/libjpeg/jpeglib.h@b8a032363ba2 (annotated)

media/libjpeg/jpeglib.h