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++ /*
++ * jpeglib.h
++ *
++ * This file was part of the Independent JPEG Group's software:
++ * Copyright (C) 1991-1998, Thomas G. Lane.
++ * Modified 2002-2009 by Guido Vollbeding.
++ * Lossless JPEG Modifications:
++ * Copyright (C) 1999, Ken Murchison.
++ * libjpeg-turbo Modifications:
++ * Copyright (C) 2009-2011, 2013-2014, 2016-2017, 2020, 2022-2024,
++ D. R. Commander.
++ * Copyright (C) 2015, Google, Inc.
++ * For conditions of distribution and use, see the accompanying README.ijg
++ * 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.
++ */
++
++ /* NOTE: This header file does not include stdio.h, despite the fact that it
++ * uses FILE and size_t. That is by design, since the libjpeg API predates the
++ * widespread adoption of ANSI/ISO C. Referring to libjpeg.txt, it is a
++ * documented requirement that calling programs "include system headers that
++ * define at least the typedefs FILE and size_t" before including jpeglib.h.
++ * Technically speaking, changing that requirement by including stdio.h here
++ * would break backward API compatibility. Please do not file bug reports,
++ * feature requests, or pull requests regarding this.
++ */
++
++ #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.
++ */
++
++ /* NOTE: In lossless mode, an MCU contains one or more samples rather than one
++ * or more 8x8 DCT blocks, so the term "data unit" is used to generically
++ * describe a sample in lossless mode or an 8x8 DCT block in lossy mode. To
++ * preserve backward API/ABI compatibility, the field and macro names retain
++ * the "block" terminology.
++ */
++
++ #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 data units/MCU */
++ #ifndef D_MAX_BLOCKS_IN_MCU
++ #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on data units/MCU */
++ #endif
++
++
++ /* Data structures for images (arrays of samples and of DCT coefficients).
++ */
++
++ typedef JSAMPLE *JSAMPROW; /* ptr to one image row of pixel samples with
++ 2-bit through 8-bit data precision. */
++ typedef JSAMPROW *JSAMPARRAY; /* ptr to some JSAMPLE rows (a 2-D JSAMPLE
++ array) */
++ typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D JSAMPLE array: top index is color */
++
++ typedef J12SAMPLE *J12SAMPROW; /* ptr to one image row of pixel samples
++ with 9-bit through 12-bit data
++ precision. */
++ typedef J12SAMPROW *J12SAMPARRAY; /* ptr to some J12SAMPLE rows (a 2-D
++ J12SAMPLE array) */
++ typedef J12SAMPARRAY *J12SAMPIMAGE; /* a 3-D J12SAMPLE array: top index is
++ color */
++
++ typedef J16SAMPLE *J16SAMPROW; /* ptr to one image row of pixel samples
++ with 13-bit through 16-bit data
++ precision. */
++ typedef J16SAMPROW *J16SAMPARRAY; /* ptr to some J16SAMPLE rows (a 2-D
++ J16SAMPLE array) */
++ typedef J16SAMPARRAY *J16SAMPIMAGE; /* a 3-D J16SAMPLE array: top index is
++ color */
++
++ typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
++ typedef JBLOCK *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 *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 data units.
++ * In lossy mode, 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. In lossless mode, these are always equal to the image width and
++ * height.
++ */
++ JDIMENSION width_in_blocks;
++ JDIMENSION height_in_blocks;
++ /* Size of a data unit in samples. Always DCTSIZE for lossy compression.
++ * For lossy decompression this is the size of the output from one DCT block,
++ * reflecting any scaling we choose to apply during the IDCT step.
++ * Values from 1 to 16 are supported. Note that different components may
++ * receive different IDCT scalings. In lossless mode, this is always equal
++ * to 1.
++ */
++ #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 lossy decompression, IDCT scaling is
++ * included, so
++ * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]scaled_size/DCTSIZE)
++ * In lossless mode, these are always equal to the image width and height.
++ */
++ 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 data units per MCU, horizontally */
++ int MCU_height; /* number of data units 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 data units across in last MCU */
++ int last_row_height; /* # of non-dummy data units 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
++ (Ss is the predictor selection value in
++ lossless mode) */
++ int Ah, Al; /* progressive JPEG successive approx. parms
++ (Al is the point transform value in lossless
++ mode) */
++ } jpeg_scan_info;
++
++ /* The decompressor can save APPn and COM markers in a list of these: */
++
++ typedef struct jpeg_marker_struct *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 *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 */
++ JCS_RGB565 /* 5-bit red/6-bit green/5-bit blue
++ [decompression only] */
++ } J_COLOR_SPACE;
++
++ /* DCT/IDCT algorithm options. */
++
++ typedef enum {
++ JDCT_ISLOW, /* accurate integer method */
++ JDCT_IFAST, /* less accurate integer method [legacy feature] */
++ JDCT_FLOAT /* floating-point method [legacy feature] */
++ } 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 coefficient or
++ difference controller */
++ /* The coefficient or difference controller receives data in units of MCU
++ * rows as defined for fully interleaved scans (whether the JPEG file is
++ * interleaved or not). In lossy mode, there are v_samp_factor * DCTSIZE
++ * sample rows of each component in an "iMCU" (interleaved MCU) row. In
++ * lossless mode, total_iMCU_rows is always equal to the image height.
++ */
++
++ /*
++ * 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 data units per MCU */
++ int MCU_membership[C_MAX_BLOCKS_IN_MCU];
++ /* MCU_membership[i] is index in cur_comp_info of component owning */
++ /* i'th data unit in an MCU */
++
++ int Ss, Se, Ah, Al; /* progressive/lossless 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
++ If data_precision is 12, then this is
++ actually a J12SAMPARRAY, so callers must
++ type-cast it in order to read/write 12-bit
++ samples from/to the 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 or difference 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. In lossy mode, 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.
++ * In lossless mode, total_iMCU_rows is always equal to the image height.
++ */
++
++ JSAMPLE *sample_range_limit; /* table for fast range-limiting
++ If data_precision is 9 to 12, then this is
++ actually a J12SAMPLE pointer, and if
++ data_precision is 13 to 16, then this is
++ actually a J16SAMPLE pointer, so callers
++ must type-cast it in order to read samples
++ from the array. */
++
++ /*
++ * 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 data units per MCU */
++ int MCU_membership[D_MAX_BLOCKS_IN_MCU];
++ /* MCU_membership[i] is index in cur_comp_info of component owning */
++ /* i'th data unit in an MCU */
++
++ int Ss, Se, Ah, Al; /* progressive/lossless 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 */
++ void (*error_exit) (j_common_ptr cinfo);
++ /* Conditionally emit a trace or warning message */
++ void (*emit_message) (j_common_ptr cinfo, int msg_level);
++ /* Routine that actually outputs a trace or error message */
++ void (*output_message) (j_common_ptr cinfo);
++ /* Format a message string for the most recent JPEG error or message */
++ 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 */
++ 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 {
++ 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 */
++
++ void (*init_destination) (j_compress_ptr cinfo);
++ boolean (*empty_output_buffer) (j_compress_ptr cinfo);
++ 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 */
++
++ void (*init_source) (j_decompress_ptr cinfo);
++ boolean (*fill_input_buffer) (j_decompress_ptr cinfo);
++ void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes);
++ boolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired);
++ 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 */
++ void *(*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject);
++ void *(*alloc_large) (j_common_ptr cinfo, int pool_id,
++ size_t sizeofobject);
++ /* If cinfo->data_precision is 12 or 16, then this method and the
++ * access_virt_sarray method actually return a J12SAMPARRAY or a
++ * J16SAMPARRAY, so callers must type-cast the return value in order to
++ * read/write 12-bit or 16-bit samples from/to the array.
++ */
++ JSAMPARRAY (*alloc_sarray) (j_common_ptr cinfo, int pool_id,
++ JDIMENSION samplesperrow, JDIMENSION numrows);
++ JBLOCKARRAY (*alloc_barray) (j_common_ptr cinfo, int pool_id,
++ JDIMENSION blocksperrow, JDIMENSION numrows);
++ jvirt_sarray_ptr (*request_virt_sarray) (j_common_ptr cinfo, int pool_id,
++ boolean pre_zero,
++ JDIMENSION samplesperrow,
++ JDIMENSION numrows,
++ JDIMENSION maxaccess);
++ jvirt_barray_ptr (*request_virt_barray) (j_common_ptr cinfo, int pool_id,
++ boolean pre_zero,
++ JDIMENSION blocksperrow,
++ JDIMENSION numrows,
++ JDIMENSION maxaccess);
++ void (*realize_virt_arrays) (j_common_ptr cinfo);
++ JSAMPARRAY (*access_virt_sarray) (j_common_ptr cinfo, jvirt_sarray_ptr ptr,
++ JDIMENSION start_row, JDIMENSION num_rows,
++ boolean writable);
++ JBLOCKARRAY (*access_virt_barray) (j_common_ptr cinfo, jvirt_barray_ptr ptr,
++ JDIMENSION start_row, JDIMENSION num_rows,
++ boolean writable);
++ void (*free_pool) (j_common_ptr cinfo, int pool_id);
++ 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 boolean (*jpeg_marker_parser_method) (j_decompress_ptr cinfo);
++
++
++ /* Originally, this macro was used as a way of defining function prototypes
++ * for both modern compilers as well as older compilers that did not support
++ * prototype parameters. libjpeg-turbo has never supported these older,
++ * non-ANSI compilers, but the macro is still included because there is some
++ * software out there that uses it.
++ */
++
++ #define JPP(arglist) arglist
++
++
++ /* Default error-management setup */
++ EXTERN(struct jpeg_error_mgr *) jpeg_std_error(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(j_compress_ptr cinfo, int version,
++ size_t structsize);
++ EXTERN(void) jpeg_CreateDecompress(j_decompress_ptr cinfo, int version,
++ size_t structsize);
++ /* Destruction of JPEG compression objects */
++ EXTERN(void) jpeg_destroy_compress(j_compress_ptr cinfo);
++ EXTERN(void) jpeg_destroy_decompress(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(j_compress_ptr cinfo, FILE *outfile);
++ EXTERN(void) jpeg_stdio_src(j_decompress_ptr cinfo, FILE *infile);
++
++ /* Data source and destination managers: memory buffers. */
++ EXTERN(void) jpeg_mem_dest(j_compress_ptr cinfo, unsigned char **outbuffer,
++ unsigned long *outsize);
++ EXTERN(void) jpeg_mem_src(j_decompress_ptr cinfo,
++ const unsigned char *inbuffer, unsigned long insize);
++
++ /* Default parameter setup for compression */
++ EXTERN(void) jpeg_set_defaults(j_compress_ptr cinfo);
++ /* Compression parameter setup aids */
++ EXTERN(void) jpeg_set_colorspace(j_compress_ptr cinfo,
++ J_COLOR_SPACE colorspace);
++ EXTERN(void) jpeg_default_colorspace(j_compress_ptr cinfo);
++ EXTERN(void) jpeg_set_quality(j_compress_ptr cinfo, int quality,
++ boolean force_baseline);
++ EXTERN(void) jpeg_set_linear_quality(j_compress_ptr cinfo, int scale_factor,
++ boolean force_baseline);
++ #if JPEG_LIB_VERSION >= 70
++ EXTERN(void) jpeg_default_qtables(j_compress_ptr cinfo,
++ boolean force_baseline);
++ #endif
++ EXTERN(void) jpeg_add_quant_table(j_compress_ptr cinfo, int which_tbl,
++ const unsigned int *basic_table,
++ int scale_factor, boolean force_baseline);
++ EXTERN(int) jpeg_quality_scaling(int quality);
++ EXTERN(void) jpeg_enable_lossless(j_compress_ptr cinfo,
++ int predictor_selection_value,
++ int point_transform);
++ EXTERN(void) jpeg_simple_progression(j_compress_ptr cinfo);
++ EXTERN(void) jpeg_suppress_tables(j_compress_ptr cinfo, boolean suppress);
++ EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table(j_common_ptr cinfo);
++ EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table(j_common_ptr cinfo);
++
++ /* Main entry points for compression */
++ EXTERN(void) jpeg_start_compress(j_compress_ptr cinfo,
++ boolean write_all_tables);
++ EXTERN(JDIMENSION) jpeg_write_scanlines(j_compress_ptr cinfo,
++ JSAMPARRAY scanlines,
++ JDIMENSION num_lines);
++ EXTERN(JDIMENSION) jpeg12_write_scanlines(j_compress_ptr cinfo,
++ J12SAMPARRAY scanlines,
++ JDIMENSION num_lines);
++ EXTERN(JDIMENSION) jpeg16_write_scanlines(j_compress_ptr cinfo,
++ J16SAMPARRAY scanlines,
++ JDIMENSION num_lines);
++ EXTERN(void) jpeg_finish_compress(j_compress_ptr cinfo);
++
++ #if JPEG_LIB_VERSION >= 70
++ /* Precalculate JPEG dimensions for current compression parameters. */
++ EXTERN(void) jpeg_calc_jpeg_dimensions(j_compress_ptr cinfo);
++ #endif
++
++ /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
++ EXTERN(JDIMENSION) jpeg_write_raw_data(j_compress_ptr cinfo, JSAMPIMAGE data,
++ JDIMENSION num_lines);
++ EXTERN(JDIMENSION) jpeg12_write_raw_data(j_compress_ptr cinfo,
++ J12SAMPIMAGE data,
++ JDIMENSION num_lines);
++
++ /* Write a special marker. See libjpeg.txt concerning safe usage. */
++ EXTERN(void) jpeg_write_marker(j_compress_ptr cinfo, int marker,
++ const JOCTET *dataptr, unsigned int datalen);
++ /* Same, but piecemeal. */
++ EXTERN(void) jpeg_write_m_header(j_compress_ptr cinfo, int marker,
++ unsigned int datalen);
++ EXTERN(void) jpeg_write_m_byte(j_compress_ptr cinfo, int val);
++
++ /* Alternate compression function: just write an abbreviated table file */
++ EXTERN(void) jpeg_write_tables(j_compress_ptr cinfo);
++
++ /* Write ICC profile. See libjpeg.txt for usage information. */
++ EXTERN(void) jpeg_write_icc_profile(j_compress_ptr cinfo,
++ const JOCTET *icc_data_ptr,
++ unsigned int icc_data_len);
++
++
++ /* Decompression startup: read start of JPEG datastream to see what's there */
++ EXTERN(int) jpeg_read_header(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(j_decompress_ptr cinfo);
++ EXTERN(JDIMENSION) jpeg_read_scanlines(j_decompress_ptr cinfo,
++ JSAMPARRAY scanlines,
++ JDIMENSION max_lines);
++ EXTERN(JDIMENSION) jpeg12_read_scanlines(j_decompress_ptr cinfo,
++ J12SAMPARRAY scanlines,
++ JDIMENSION max_lines);
++ EXTERN(JDIMENSION) jpeg16_read_scanlines(j_decompress_ptr cinfo,
++ J16SAMPARRAY scanlines,
++ JDIMENSION max_lines);
++ EXTERN(JDIMENSION) jpeg_skip_scanlines(j_decompress_ptr cinfo,
++ JDIMENSION num_lines);
++ EXTERN(JDIMENSION) jpeg12_skip_scanlines(j_decompress_ptr cinfo,
++ JDIMENSION num_lines);
++ EXTERN(void) jpeg_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
++ JDIMENSION *width);
++ EXTERN(void) jpeg12_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
++ JDIMENSION *width);
++ EXTERN(boolean) jpeg_finish_decompress(j_decompress_ptr cinfo);
++
++ /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
++ EXTERN(JDIMENSION) jpeg_read_raw_data(j_decompress_ptr cinfo, JSAMPIMAGE data,
++ JDIMENSION max_lines);
++ EXTERN(JDIMENSION) jpeg12_read_raw_data(j_decompress_ptr cinfo,
++ J12SAMPIMAGE data,
++ JDIMENSION max_lines);
++
++ /* Additional entry points for buffered-image mode. */
++ EXTERN(boolean) jpeg_has_multiple_scans(j_decompress_ptr cinfo);
++ EXTERN(boolean) jpeg_start_output(j_decompress_ptr cinfo, int scan_number);
++ EXTERN(boolean) jpeg_finish_output(j_decompress_ptr cinfo);
++ EXTERN(boolean) jpeg_input_complete(j_decompress_ptr cinfo);
++ EXTERN(void) jpeg_new_colormap(j_decompress_ptr cinfo);
++ EXTERN(int) jpeg_consume_input(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(j_decompress_ptr cinfo);
++ #endif
++ EXTERN(void) jpeg_calc_output_dimensions(j_decompress_ptr cinfo);
++
++ /* Control saving of COM and APPn markers into marker_list. */
++ EXTERN(void) jpeg_save_markers(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(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(j_decompress_ptr cinfo);
++ EXTERN(void) jpeg_write_coefficients(j_compress_ptr cinfo,
++ jvirt_barray_ptr *coef_arrays);
++ EXTERN(void) jpeg_copy_critical_parameters(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(j_compress_ptr cinfo);
++ EXTERN(void) jpeg_abort_decompress(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(j_common_ptr cinfo);
++ EXTERN(void) jpeg_destroy(j_common_ptr cinfo);
++
++ /* Default restart-marker-resync procedure for use by data source modules */
++ EXTERN(boolean) jpeg_resync_to_restart(j_decompress_ptr cinfo, int desired);
++
++ /* Read ICC profile. See libjpeg.txt for usage information. */
++ EXTERN(boolean) jpeg_read_icc_profile(j_decompress_ptr cinfo,
++ JOCTET **icc_data_ptr,
++ unsigned int *icc_data_len);
++
++
++ /* 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 */