jpeglib.h

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00001 /*
00002  * jpeglib.h
00003  *
00004  * Copyright (C) 1991-1998, Thomas G. Lane.
00005  * This file is part of the Independent JPEG Group's software.
00006  * For conditions of distribution and use, see the accompanying README file.
00007  *
00008  * This file defines the application interface for the JPEG library.
00009  * Most applications using the library need only include this file,
00010  * and perhaps jerror.h if they want to know the exact error codes.
00011  */
00012 
00013 #ifndef JPEGLIB_H
00014 #define JPEGLIB_H
00015 
00019 
00020 /*
00021  * First we include the configuration files that record how this
00022  * installation of the JPEG library is set up.  jconfig.h can be
00023  * generated automatically for many systems.  jmorecfg.h contains
00024  * manual configuration options that most people need not worry about.
00025  */
00026 
00027 #ifndef JCONFIG_INCLUDED    /* in case jinclude.h already did */
00028 #include "jconfig.h"        /* widely used configuration options */
00029 #endif
00030 #include "jmorecfg.h"       /* seldom changed options */
00031 
00032 
00033 /* Version ID for the JPEG library.
00034  * Might be useful for tests like "#if JPEG_LIB_VERSION >= 60".
00035  */
00036 
00037 #define JPEG_LIB_VERSION  62    /* Version 6b */
00038 
00039 
00040 /* Various constants determining the sizes of things.
00041  * All of these are specified by the JPEG standard, so don't change them
00042  * if you want to be compatible.
00043  */
00044 
00045 #define DCTSIZE         8   /* The basic DCT block is 8x8 samples */
00046 #define DCTSIZE2        64  /* DCTSIZE squared; # of elements in a block */
00047 #define NUM_QUANT_TBLS      4   /* Quantization tables are numbered 0..3 */
00048 #define NUM_HUFF_TBLS       4   /* Huffman tables are numbered 0..3 */
00049 #define NUM_ARITH_TBLS      16  /* Arith-coding tables are numbered 0..15 */
00050 #define MAX_COMPS_IN_SCAN   4   /* JPEG limit on # of components in one scan */
00051 #define MAX_SAMP_FACTOR     4   /* JPEG limit on sampling factors */
00052 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
00053  * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
00054  * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
00055  * to handle it.  We even let you do this from the jconfig.h file.  However,
00056  * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
00057  * sometimes emits noncompliant files doesn't mean you should too.
00058  */
00059 #define C_MAX_BLOCKS_IN_MCU   10 /* compressor's limit on blocks per MCU */
00060 #ifndef D_MAX_BLOCKS_IN_MCU
00061 #define D_MAX_BLOCKS_IN_MCU   10 /* decompressor's limit on blocks per MCU */
00062 #endif
00063 
00064 
00065 /* Data structures for images (arrays of samples and of DCT coefficients).
00066  * On 80x86 machines, the image arrays are too big for near pointers,
00067  * but the pointer arrays can fit in near memory.
00068  */
00069 
00070 typedef JSAMPLE FAR *JSAMPROW;  /* ptr to one image row of pixel samples. */
00071 typedef JSAMPROW *JSAMPARRAY;   /* ptr to some rows (a 2-D sample array) */
00072 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
00073 
00074 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
00075 typedef JBLOCK FAR *JBLOCKROW;  /* pointer to one row of coefficient blocks */
00076 typedef JBLOCKROW *JBLOCKARRAY;     /* a 2-D array of coefficient blocks */
00077 typedef JBLOCKARRAY *JBLOCKIMAGE;   /* a 3-D array of coefficient blocks */
00078 
00079 typedef JCOEF FAR *JCOEFPTR;    /* useful in a couple of places */
00080 
00081 
00082 /* Types for JPEG compression parameters and working tables. */
00083 
00084 
00085 /* DCT coefficient quantization tables. */
00086 
00087 typedef struct {
00088   /* This array gives the coefficient quantizers in natural array order
00089    * (not the zigzag order in which they are stored in a JPEG DQT marker).
00090    * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
00091    */
00092   UINT16 quantval[DCTSIZE2];    /* quantization step for each coefficient */
00093   /* This field is used only during compression.  It's initialized FALSE when
00094    * the table is created, and set TRUE when it's been output to the file.
00095    * You could suppress output of a table by setting this to TRUE.
00096    * (See jpeg_suppress_tables for an example.)
00097    */
00098   boolean sent_table;       /* TRUE when table has been output */
00099 } JQUANT_TBL;
00100 
00101 
00102 /* Huffman coding tables. */
00103 
00104 typedef struct {
00105   /* These two fields directly represent the contents of a JPEG DHT marker */
00106   UINT8 bits[17];       /* bits[k] = # of symbols with codes of */
00107                 /* length k bits; bits[0] is unused */
00108   UINT8 huffval[256];       /* The symbols, in order of incr code length */
00109   /* This field is used only during compression.  It's initialized FALSE when
00110    * the table is created, and set TRUE when it's been output to the file.
00111    * You could suppress output of a table by setting this to TRUE.
00112    * (See jpeg_suppress_tables for an example.)
00113    */
00114   boolean sent_table;       /* TRUE when table has been output */
00115 } JHUFF_TBL;
00116 
00117 
00118 /* Basic info about one component (color channel). */
00119 
00120 typedef struct {
00121   /* These values are fixed over the whole image. */
00122   /* For compression, they must be supplied by parameter setup; */
00123   /* for decompression, they are read from the SOF marker. */
00124   int component_id;     /* identifier for this component (0..255) */
00125   int component_index;      /* its index in SOF or cinfo->comp_info[] */
00126   int h_samp_factor;        /* horizontal sampling factor (1..4) */
00127   int v_samp_factor;        /* vertical sampling factor (1..4) */
00128   int quant_tbl_no;     /* quantization table selector (0..3) */
00129   /* These values may vary between scans. */
00130   /* For compression, they must be supplied by parameter setup; */
00131   /* for decompression, they are read from the SOS marker. */
00132   /* The decompressor output side may not use these variables. */
00133   int dc_tbl_no;        /* DC entropy table selector (0..3) */
00134   int ac_tbl_no;        /* AC entropy table selector (0..3) */
00135   
00136   /* Remaining fields should be treated as private by applications. */
00137   
00138   /* These values are computed during compression or decompression startup: */
00139   /* Component's size in DCT blocks.
00140    * Any dummy blocks added to complete an MCU are not counted; therefore
00141    * these values do not depend on whether a scan is interleaved or not.
00142    */
00143   JDIMENSION width_in_blocks;
00144   JDIMENSION height_in_blocks;
00145   /* Size of a DCT block in samples.  Always DCTSIZE for compression.
00146    * For decompression this is the size of the output from one DCT block,
00147    * reflecting any scaling we choose to apply during the IDCT step.
00148    * Values of 1,2,4,8 are likely to be supported.  Note that different
00149    * components may receive different IDCT scalings.
00150    */
00151   int DCT_scaled_size;
00152   /* The downsampled dimensions are the component's actual, unpadded number
00153    * of samples at the main buffer (preprocessing/compression interface), thus
00154    * downsampled_width = ceil(image_width * Hi/Hmax)
00155    * and similarly for height.  For decompression, IDCT scaling is included, so
00156    * downsampled_width = ceil(image_width * Hi/Hmax * DCT_scaled_size/DCTSIZE)
00157    */
00158   JDIMENSION downsampled_width;  /* actual width in samples */
00159   JDIMENSION downsampled_height; /* actual height in samples */
00160   /* This flag is used only for decompression.  In cases where some of the
00161    * components will be ignored (eg grayscale output from YCbCr image),
00162    * we can skip most computations for the unused components.
00163    */
00164   boolean component_needed; /* do we need the value of this component? */
00165 
00166   /* These values are computed before starting a scan of the component. */
00167   /* The decompressor output side may not use these variables. */
00168   int MCU_width;        /* number of blocks per MCU, horizontally */
00169   int MCU_height;       /* number of blocks per MCU, vertically */
00170   int MCU_blocks;       /* MCU_width * MCU_height */
00171   int MCU_sample_width;     /* MCU width in samples, MCU_width*DCT_scaled_size */
00172   int last_col_width;       /* # of non-dummy blocks across in last MCU */
00173   int last_row_height;      /* # of non-dummy blocks down in last MCU */
00174 
00175   /* Saved quantization table for component; NULL if none yet saved.
00176    * See jdinput.c comments about the need for this information.
00177    * This field is currently used only for decompression.
00178    */
00179   JQUANT_TBL * quant_table;
00180 
00181   /* Private per-component storage for DCT or IDCT subsystem. */
00182   void * dct_table;
00183 } jpeg_component_info;
00184 
00185 
00186 /* The script for encoding a multiple-scan file is an array of these: */
00187 
00188 typedef struct {
00189   int comps_in_scan;        /* number of components encoded in this scan */
00190   int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
00191   int Ss, Se;           /* progressive JPEG spectral selection parms */
00192   int Ah, Al;           /* progressive JPEG successive approx. parms */
00193 } jpeg_scan_info;
00194 
00195 /* The decompressor can save APPn and COM markers in a list of these: */
00196 
00197 typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr;
00198 
00199 struct jpeg_marker_struct {
00200   jpeg_saved_marker_ptr next;   /* next in list, or NULL */
00201   UINT8 marker;         /* marker code: JPEG_COM, or JPEG_APP0+n */
00202   unsigned int original_length; /* # bytes of data in the file */
00203   unsigned int data_length; /* # bytes of data saved at data[] */
00204   JOCTET FAR * data;        /* the data contained in the marker */
00205   /* the marker length word is not counted in data_length or original_length */
00206 };
00207 
00208 /* Known color spaces. */
00209 
00210 typedef enum {
00211     JCS_UNKNOWN,        /* error/unspecified */
00212     JCS_GRAYSCALE,      /* monochrome */
00213     JCS_RGB,        /* red/green/blue */
00214     JCS_YCbCr,      /* Y/Cb/Cr (also known as YUV) */
00215     JCS_CMYK,       /* C/M/Y/K */
00216     JCS_YCCK        /* Y/Cb/Cr/K */
00217 } J_COLOR_SPACE;
00218 
00219 /* DCT/IDCT algorithm options. */
00220 
00221 typedef enum {
00222     JDCT_ISLOW,     /* slow but accurate integer algorithm */
00223     JDCT_IFAST,     /* faster, less accurate integer method */
00224     JDCT_FLOAT      /* floating-point: accurate, fast on fast HW */
00225 } J_DCT_METHOD;
00226 
00227 #ifndef JDCT_DEFAULT        /* may be overridden in jconfig.h */
00228 #define JDCT_DEFAULT  JDCT_ISLOW
00229 #endif
00230 #ifndef JDCT_FASTEST        /* may be overridden in jconfig.h */
00231 #define JDCT_FASTEST  JDCT_IFAST
00232 #endif
00233 
00234 /* Dithering options for decompression. */
00235 
00236 typedef enum {
00237     JDITHER_NONE,       /* no dithering */
00238     JDITHER_ORDERED,    /* simple ordered dither */
00239     JDITHER_FS      /* Floyd-Steinberg error diffusion dither */
00240 } J_DITHER_MODE;
00241 
00242 
00243 /* Common fields between JPEG compression and decompression master structs. */
00244 
00245 #define jpeg_common_fields \
00246   struct jpeg_error_mgr * err;  /* Error handler module */\
00247   struct jpeg_memory_mgr * mem; /* Memory manager module */\
00248   struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
00249   void * client_data;       /* Available for use by application */\
00250   boolean is_decompressor;  /* So common code can tell which is which */\
00251   int global_state      /* For checking call sequence validity */
00252 
00253 /* Routines that are to be used by both halves of the library are declared
00254  * to receive a pointer to this structure.  There are no actual instances of
00255  * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
00256  */
00257 struct jpeg_common_struct {
00258   jpeg_common_fields;       /* Fields common to both master struct types */
00259   /* Additional fields follow in an actual jpeg_compress_struct or
00260    * jpeg_decompress_struct.  All three structs must agree on these
00261    * initial fields!  (This would be a lot cleaner in C++.)
00262    */
00263 };
00264 
00265 typedef struct jpeg_common_struct * j_common_ptr;
00266 typedef struct jpeg_compress_struct * j_compress_ptr;
00267 typedef struct jpeg_decompress_struct * j_decompress_ptr;
00268 
00269 
00270 /* Master record for a compression instance */
00271 
00272 struct jpeg_compress_struct {
00273   jpeg_common_fields;       /* Fields shared with jpeg_decompress_struct */
00274 
00275   /* Destination for compressed data */
00276   struct jpeg_destination_mgr * dest;
00277 
00278   /* Description of source image --- these fields must be filled in by
00279    * outer application before starting compression.  in_color_space must
00280    * be correct before you can even call jpeg_set_defaults().
00281    */
00282 
00283   JDIMENSION image_width;   /* input image width */
00284   JDIMENSION image_height;  /* input image height */
00285   int input_components;     /* # of color components in input image */
00286   J_COLOR_SPACE in_color_space; /* colorspace of input image */
00287 
00288   double input_gamma;       /* image gamma of input image */
00289 
00290   /* Compression parameters --- these fields must be set before calling
00291    * jpeg_start_compress().  We recommend calling jpeg_set_defaults() to
00292    * initialize everything to reasonable defaults, then changing anything
00293    * the application specifically wants to change.  That way you won't get
00294    * burnt when new parameters are added.  Also note that there are several
00295    * helper routines to simplify changing parameters.
00296    */
00297 
00298   int data_precision;       /* bits of precision in image data */
00299 
00300   int num_components;       /* # of color components in JPEG image */
00301   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
00302 
00303   jpeg_component_info * comp_info;
00304   /* comp_info[i] describes component that appears i'th in SOF */
00305   
00306   JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
00307   /* ptrs to coefficient quantization tables, or NULL if not defined */
00308   
00309   JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
00310   JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
00311   /* ptrs to Huffman coding tables, or NULL if not defined */
00312   
00313   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
00314   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
00315   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
00316 
00317   int num_scans;        /* # of entries in scan_info array */
00318   const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */
00319   /* The default value of scan_info is NULL, which causes a single-scan
00320    * sequential JPEG file to be emitted.  To create a multi-scan file,
00321    * set num_scans and scan_info to point to an array of scan definitions.
00322    */
00323 
00324   boolean raw_data_in;      /* TRUE=caller supplies downsampled data */
00325   boolean arith_code;       /* TRUE=arithmetic coding, FALSE=Huffman */
00326   boolean optimize_coding;  /* TRUE=optimize entropy encoding parms */
00327   boolean CCIR601_sampling; /* TRUE=first samples are cosited */
00328   int smoothing_factor;     /* 1..100, or 0 for no input smoothing */
00329   J_DCT_METHOD dct_method;  /* DCT algorithm selector */
00330 
00331   /* The restart interval can be specified in absolute MCUs by setting
00332    * restart_interval, or in MCU rows by setting restart_in_rows
00333    * (in which case the correct restart_interval will be figured
00334    * for each scan).
00335    */
00336   unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
00337   int restart_in_rows;      /* if > 0, MCU rows per restart interval */
00338 
00339   /* Parameters controlling emission of special markers. */
00340 
00341   boolean write_JFIF_header;    /* should a JFIF marker be written? */
00342   UINT8 JFIF_major_version; /* What to write for the JFIF version number */
00343   UINT8 JFIF_minor_version;
00344   /* These three values are not used by the JPEG code, merely copied */
00345   /* into the JFIF APP0 marker.  density_unit can be 0 for unknown, */
00346   /* 1 for dots/inch, or 2 for dots/cm.  Note that the pixel aspect */
00347   /* ratio is defined by X_density/Y_density even when density_unit=0. */
00348   UINT8 density_unit;       /* JFIF code for pixel size units */
00349   UINT16 X_density;     /* Horizontal pixel density */
00350   UINT16 Y_density;     /* Vertical pixel density */
00351   boolean write_Adobe_marker;   /* should an Adobe marker be written? */
00352   
00353   /* State variable: index of next scanline to be written to
00354    * jpeg_write_scanlines().  Application may use this to control its
00355    * processing loop, e.g., "while (next_scanline < image_height)".
00356    */
00357 
00358   JDIMENSION next_scanline; /* 0 .. image_height-1  */
00359 
00360   /* Remaining fields are known throughout compressor, but generally
00361    * should not be touched by a surrounding application.
00362    */
00363 
00364   /*
00365    * These fields are computed during compression startup
00366    */
00367   boolean progressive_mode; /* TRUE if scan script uses progressive mode */
00368   int max_h_samp_factor;    /* largest h_samp_factor */
00369   int max_v_samp_factor;    /* largest v_samp_factor */
00370 
00371   JDIMENSION total_iMCU_rows;   /* # of iMCU rows to be input to coef ctlr */
00372   /* The coefficient controller receives data in units of MCU rows as defined
00373    * for fully interleaved scans (whether the JPEG file is interleaved or not).
00374    * There are v_samp_factor * DCTSIZE sample rows of each component in an
00375    * "iMCU" (interleaved MCU) row.
00376    */
00377   
00378   /*
00379    * These fields are valid during any one scan.
00380    * They describe the components and MCUs actually appearing in the scan.
00381    */
00382   int comps_in_scan;        /* # of JPEG components in this scan */
00383   jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
00384   /* *cur_comp_info[i] describes component that appears i'th in SOS */
00385   
00386   JDIMENSION MCUs_per_row;  /* # of MCUs across the image */
00387   JDIMENSION MCU_rows_in_scan;  /* # of MCU rows in the image */
00388   
00389   int blocks_in_MCU;        /* # of DCT blocks per MCU */
00390   int MCU_membership[C_MAX_BLOCKS_IN_MCU];
00391   /* MCU_membership[i] is index in cur_comp_info of component owning */
00392   /* i'th block in an MCU */
00393 
00394   int Ss, Se, Ah, Al;       /* progressive JPEG parameters for scan */
00395 
00396   /*
00397    * Links to compression subobjects (methods and private variables of modules)
00398    */
00399   struct jpeg_comp_master * master;
00400   struct jpeg_c_main_controller * main;
00401   struct jpeg_c_prep_controller * prep;
00402   struct jpeg_c_coef_controller * coef;
00403   struct jpeg_marker_writer * marker;
00404   struct jpeg_color_converter * cconvert;
00405   struct jpeg_downsampler * downsample;
00406   struct jpeg_forward_dct * fdct;
00407   struct jpeg_entropy_encoder * entropy;
00408   jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */
00409   int script_space_size;
00410 };
00411 
00412 
00413 /* Master record for a decompression instance */
00414 
00415 struct jpeg_decompress_struct {
00416   jpeg_common_fields;       /* Fields shared with jpeg_compress_struct */
00417 
00418   /* Source of compressed data */
00419   struct jpeg_source_mgr * src;
00420 
00421   /* Basic description of image --- filled in by jpeg_read_header(). */
00422   /* Application may inspect these values to decide how to process image. */
00423 
00424   JDIMENSION image_width;   /* nominal image width (from SOF marker) */
00425   JDIMENSION image_height;  /* nominal image height */
00426   int num_components;       /* # of color components in JPEG image */
00427   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
00428 
00429   /* Decompression processing parameters --- these fields must be set before
00430    * calling jpeg_start_decompress().  Note that jpeg_read_header() initializes
00431    * them to default values.
00432    */
00433 
00434   J_COLOR_SPACE out_color_space; /* colorspace for output */
00435 
00436   unsigned int scale_num, scale_denom; /* fraction by which to scale image */
00437 
00438   double output_gamma;      /* image gamma wanted in output */
00439 
00440   boolean buffered_image;   /* TRUE=multiple output passes */
00441   boolean raw_data_out;     /* TRUE=downsampled data wanted */
00442 
00443   J_DCT_METHOD dct_method;  /* IDCT algorithm selector */
00444   boolean do_fancy_upsampling;  /* TRUE=apply fancy upsampling */
00445   boolean do_block_smoothing;   /* TRUE=apply interblock smoothing */
00446 
00447   boolean quantize_colors;  /* TRUE=colormapped output wanted */
00448   /* the following are ignored if not quantize_colors: */
00449   J_DITHER_MODE dither_mode;    /* type of color dithering to use */
00450   boolean two_pass_quantize;    /* TRUE=use two-pass color quantization */
00451   int desired_number_of_colors; /* max # colors to use in created colormap */
00452   /* these are significant only in buffered-image mode: */
00453   boolean enable_1pass_quant;   /* enable future use of 1-pass quantizer */
00454   boolean enable_external_quant;/* enable future use of external colormap */
00455   boolean enable_2pass_quant;   /* enable future use of 2-pass quantizer */
00456 
00457   /* Description of actual output image that will be returned to application.
00458    * These fields are computed by jpeg_start_decompress().
00459    * You can also use jpeg_calc_output_dimensions() to determine these values
00460    * in advance of calling jpeg_start_decompress().
00461    */
00462 
00463   JDIMENSION output_width;  /* scaled image width */
00464   JDIMENSION output_height; /* scaled image height */
00465   int out_color_components; /* # of color components in out_color_space */
00466   int output_components;    /* # of color components returned */
00467   /* output_components is 1 (a colormap index) when quantizing colors;
00468    * otherwise it equals out_color_components.
00469    */
00470   int rec_outbuf_height;    /* min recommended height of scanline buffer */
00471   /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
00472    * high, space and time will be wasted due to unnecessary data copying.
00473    * Usually rec_outbuf_height will be 1 or 2, at most 4.
00474    */
00475 
00476   /* When quantizing colors, the output colormap is described by these fields.
00477    * The application can supply a colormap by setting colormap non-NULL before
00478    * calling jpeg_start_decompress; otherwise a colormap is created during
00479    * jpeg_start_decompress or jpeg_start_output.
00480    * The map has out_color_components rows and actual_number_of_colors columns.
00481    */
00482   int actual_number_of_colors;  /* number of entries in use */
00483   JSAMPARRAY colormap;      /* The color map as a 2-D pixel array */
00484 
00485   /* State variables: these variables indicate the progress of decompression.
00486    * The application may examine these but must not modify them.
00487    */
00488 
00489   /* Row index of next scanline to be read from jpeg_read_scanlines().
00490    * Application may use this to control its processing loop, e.g.,
00491    * "while (output_scanline < output_height)".
00492    */
00493   JDIMENSION output_scanline;   /* 0 .. output_height-1  */
00494 
00495   /* Current input scan number and number of iMCU rows completed in scan.
00496    * These indicate the progress of the decompressor input side.
00497    */
00498   int input_scan_number;    /* Number of SOS markers seen so far */
00499   JDIMENSION input_iMCU_row;    /* Number of iMCU rows completed */
00500 
00501   /* The "output scan number" is the notional scan being displayed by the
00502    * output side.  The decompressor will not allow output scan/row number
00503    * to get ahead of input scan/row, but it can fall arbitrarily far behind.
00504    */
00505   int output_scan_number;   /* Nominal scan number being displayed */
00506   JDIMENSION output_iMCU_row;   /* Number of iMCU rows read */
00507 
00508   /* Current progression status.  coef_bits[c][i] indicates the precision
00509    * with which component c's DCT coefficient i (in zigzag order) is known.
00510    * It is -1 when no data has yet been received, otherwise it is the point
00511    * transform (shift) value for the most recent scan of the coefficient
00512    * (thus, 0 at completion of the progression).
00513    * This pointer is NULL when reading a non-progressive file.
00514    */
00515   int (*coef_bits)[DCTSIZE2];   /* -1 or current Al value for each coef */
00516 
00517   /* Internal JPEG parameters --- the application usually need not look at
00518    * these fields.  Note that the decompressor output side may not use
00519    * any parameters that can change between scans.
00520    */
00521 
00522   /* Quantization and Huffman tables are carried forward across input
00523    * datastreams when processing abbreviated JPEG datastreams.
00524    */
00525 
00526   JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
00527   /* ptrs to coefficient quantization tables, or NULL if not defined */
00528 
00529   JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
00530   JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
00531   /* ptrs to Huffman coding tables, or NULL if not defined */
00532 
00533   /* These parameters are never carried across datastreams, since they
00534    * are given in SOF/SOS markers or defined to be reset by SOI.
00535    */
00536 
00537   int data_precision;       /* bits of precision in image data */
00538 
00539   jpeg_component_info * comp_info;
00540   /* comp_info[i] describes component that appears i'th in SOF */
00541 
00542   boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
00543   boolean arith_code;       /* TRUE=arithmetic coding, FALSE=Huffman */
00544 
00545   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
00546   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
00547   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
00548 
00549   unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
00550 
00551   /* These fields record data obtained from optional markers recognized by
00552    * the JPEG library.
00553    */
00554   boolean saw_JFIF_marker;  /* TRUE iff a JFIF APP0 marker was found */
00555   /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
00556   UINT8 JFIF_major_version; /* JFIF version number */
00557   UINT8 JFIF_minor_version;
00558   UINT8 density_unit;       /* JFIF code for pixel size units */
00559   UINT16 X_density;     /* Horizontal pixel density */
00560   UINT16 Y_density;     /* Vertical pixel density */
00561   boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
00562   UINT8 Adobe_transform;    /* Color transform code from Adobe marker */
00563 
00564   boolean CCIR601_sampling; /* TRUE=first samples are cosited */
00565 
00566   /* Aside from the specific data retained from APPn markers known to the
00567    * library, the uninterpreted contents of any or all APPn and COM markers
00568    * can be saved in a list for examination by the application.
00569    */
00570   jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
00571 
00572   /* Remaining fields are known throughout decompressor, but generally
00573    * should not be touched by a surrounding application.
00574    */
00575 
00576   /*
00577    * These fields are computed during decompression startup
00578    */
00579   int max_h_samp_factor;    /* largest h_samp_factor */
00580   int max_v_samp_factor;    /* largest v_samp_factor */
00581 
00582   int min_DCT_scaled_size;  /* smallest DCT_scaled_size of any component */
00583 
00584   JDIMENSION total_iMCU_rows;   /* # of iMCU rows in image */
00585   /* The coefficient controller's input and output progress is measured in
00586    * units of "iMCU" (interleaved MCU) rows.  These are the same as MCU rows
00587    * in fully interleaved JPEG scans, but are used whether the scan is
00588    * interleaved or not.  We define an iMCU row as v_samp_factor DCT block
00589    * rows of each component.  Therefore, the IDCT output contains
00590    * v_samp_factor*DCT_scaled_size sample rows of a component per iMCU row.
00591    */
00592 
00593   JSAMPLE * sample_range_limit; /* table for fast range-limiting */
00594 
00595   /*
00596    * These fields are valid during any one scan.
00597    * They describe the components and MCUs actually appearing in the scan.
00598    * Note that the decompressor output side must not use these fields.
00599    */
00600   int comps_in_scan;        /* # of JPEG components in this scan */
00601   jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
00602   /* *cur_comp_info[i] describes component that appears i'th in SOS */
00603 
00604   JDIMENSION MCUs_per_row;  /* # of MCUs across the image */
00605   JDIMENSION MCU_rows_in_scan;  /* # of MCU rows in the image */
00606 
00607   int blocks_in_MCU;        /* # of DCT blocks per MCU */
00608   int MCU_membership[D_MAX_BLOCKS_IN_MCU];
00609   /* MCU_membership[i] is index in cur_comp_info of component owning */
00610   /* i'th block in an MCU */
00611 
00612   int Ss, Se, Ah, Al;       /* progressive JPEG parameters for scan */
00613 
00614   /* This field is shared between entropy decoder and marker parser.
00615    * It is either zero or the code of a JPEG marker that has been
00616    * read from the data source, but has not yet been processed.
00617    */
00618   int unread_marker;
00619 
00620   /*
00621    * Links to decompression subobjects (methods, private variables of modules)
00622    */
00623   struct jpeg_decomp_master * master;
00624   struct jpeg_d_main_controller * main;
00625   struct jpeg_d_coef_controller * coef;
00626   struct jpeg_d_post_controller * post;
00627   struct jpeg_input_controller * inputctl;
00628   struct jpeg_marker_reader * marker;
00629   struct jpeg_entropy_decoder * entropy;
00630   struct jpeg_inverse_dct * idct;
00631   struct jpeg_upsampler * upsample;
00632   struct jpeg_color_deconverter * cconvert;
00633   struct jpeg_color_quantizer * cquantize;
00634 };
00635 
00636 
00637 /* "Object" declarations for JPEG modules that may be supplied or called
00638  * directly by the surrounding application.
00639  * As with all objects in the JPEG library, these structs only define the
00640  * publicly visible methods and state variables of a module.  Additional
00641  * private fields may exist after the public ones.
00642  */
00643 
00644 
00645 /* Error handler object */
00646 
00647 struct jpeg_error_mgr {
00648   /* Error exit handler: does not return to caller */
00649   JMETHOD(void, error_exit, (j_common_ptr cinfo));
00650   /* Conditionally emit a trace or warning message */
00651   JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
00652   /* Routine that actually outputs a trace or error message */
00653   JMETHOD(void, output_message, (j_common_ptr cinfo));
00654   /* Format a message string for the most recent JPEG error or message */
00655   JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
00656 #define JMSG_LENGTH_MAX  200    /* recommended size of format_message buffer */
00657   /* Reset error state variables at start of a new image */
00658   JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
00659   
00660   /* The message ID code and any parameters are saved here.
00661    * A message can have one string parameter or up to 8 int parameters.
00662    */
00663   int msg_code;
00664 #define JMSG_STR_PARM_MAX  80
00665   union {
00666     int i[8];
00667     char s[JMSG_STR_PARM_MAX];
00668   } msg_parm;
00669   
00670   /* Standard state variables for error facility */
00671   
00672   int trace_level;      /* max msg_level that will be displayed */
00673   
00674   /* For recoverable corrupt-data errors, we emit a warning message,
00675    * but keep going unless emit_message chooses to abort.  emit_message
00676    * should count warnings in num_warnings.  The surrounding application
00677    * can check for bad data by seeing if num_warnings is nonzero at the
00678    * end of processing.
00679    */
00680   long num_warnings;        /* number of corrupt-data warnings */
00681 
00682   /* These fields point to the table(s) of error message strings.
00683    * An application can change the table pointer to switch to a different
00684    * message list (typically, to change the language in which errors are
00685    * reported).  Some applications may wish to add additional error codes
00686    * that will be handled by the JPEG library error mechanism; the second
00687    * table pointer is used for this purpose.
00688    *
00689    * First table includes all errors generated by JPEG library itself.
00690    * Error code 0 is reserved for a "no such error string" message.
00691    */
00692   const char * const * jpeg_message_table; /* Library errors */
00693   int last_jpeg_message;    /* Table contains strings 0..last_jpeg_message */
00694   /* Second table can be added by application (see cjpeg/djpeg for example).
00695    * It contains strings numbered first_addon_message..last_addon_message.
00696    */
00697   const char * const * addon_message_table; /* Non-library errors */
00698   int first_addon_message;  /* code for first string in addon table */
00699   int last_addon_message;   /* code for last string in addon table */
00700 };
00701 
00702 
00703 /* Progress monitor object */
00704 
00705 struct jpeg_progress_mgr {
00706   JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
00707 
00708   long pass_counter;        /* work units completed in this pass */
00709   long pass_limit;      /* total number of work units in this pass */
00710   int completed_passes;     /* passes completed so far */
00711   int total_passes;     /* total number of passes expected */
00712 };
00713 
00714 
00715 /* Data destination object for compression */
00716 
00717 struct jpeg_destination_mgr {
00718   JOCTET * next_output_byte;    /* => next byte to write in buffer */
00719   size_t free_in_buffer;    /* # of byte spaces remaining in buffer */
00720 
00721   JMETHOD(void, init_destination, (j_compress_ptr cinfo));
00722   JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
00723   JMETHOD(void, term_destination, (j_compress_ptr cinfo));
00724 };
00725 
00726 
00727 /* Data source object for decompression */
00728 
00729 struct jpeg_source_mgr {
00730   const JOCTET * next_input_byte; /* => next byte to read from buffer */
00731   size_t bytes_in_buffer;   /* # of bytes remaining in buffer */
00732 
00733   JMETHOD(void, init_source, (j_decompress_ptr cinfo));
00734   JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
00735   JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
00736   JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
00737   JMETHOD(void, term_source, (j_decompress_ptr cinfo));
00738 };
00739 
00740 
00741 /* Memory manager object.
00742  * Allocates "small" objects (a few K total), "large" objects (tens of K),
00743  * and "really big" objects (virtual arrays with backing store if needed).
00744  * The memory manager does not allow individual objects to be freed; rather,
00745  * each created object is assigned to a pool, and whole pools can be freed
00746  * at once.  This is faster and more convenient than remembering exactly what
00747  * to free, especially where malloc()/free() are not too speedy.
00748  * NB: alloc routines never return NULL.  They exit to error_exit if not
00749  * successful.
00750  */
00751 
00752 #define JPOOL_PERMANENT 0   /* lasts until master record is destroyed */
00753 #define JPOOL_IMAGE 1   /* lasts until done with image/datastream */
00754 #define JPOOL_NUMPOOLS  2
00755 
00756 typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
00757 typedef struct jvirt_barray_control * jvirt_barray_ptr;
00758 
00759 
00760 struct jpeg_memory_mgr {
00761   /* Method pointers */
00762   JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
00763                 size_t sizeofobject));
00764   JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
00765                      size_t sizeofobject));
00766   JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
00767                      JDIMENSION samplesperrow,
00768                      JDIMENSION numrows));
00769   JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
00770                       JDIMENSION blocksperrow,
00771                       JDIMENSION numrows));
00772   JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
00773                           int pool_id,
00774                           boolean pre_zero,
00775                           JDIMENSION samplesperrow,
00776                           JDIMENSION numrows,
00777                           JDIMENSION maxaccess));
00778   JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
00779                           int pool_id,
00780                           boolean pre_zero,
00781                           JDIMENSION blocksperrow,
00782                           JDIMENSION numrows,
00783                           JDIMENSION maxaccess));
00784   JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
00785   JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
00786                        jvirt_sarray_ptr ptr,
00787                        JDIMENSION start_row,
00788                        JDIMENSION num_rows,
00789                        boolean writable));
00790   JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
00791                         jvirt_barray_ptr ptr,
00792                         JDIMENSION start_row,
00793                         JDIMENSION num_rows,
00794                         boolean writable));
00795   JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
00796   JMETHOD(void, self_destruct, (j_common_ptr cinfo));
00797 
00798   /* Limit on memory allocation for this JPEG object.  (Note that this is
00799    * merely advisory, not a guaranteed maximum; it only affects the space
00800    * used for virtual-array buffers.)  May be changed by outer application
00801    * after creating the JPEG object.
00802    */
00803   long max_memory_to_use;
00804 
00805   /* Maximum allocation request accepted by alloc_large. */
00806   long max_alloc_chunk;
00807 };
00808 
00809 
00810 /* Routine signature for application-supplied marker processing methods.
00811  * Need not pass marker code since it is stored in cinfo->unread_marker.
00812  */
00813 typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
00814 
00815 
00816 /* Declarations for routines called by application.
00817  * The JPP macro hides prototype parameters from compilers that can't cope.
00818  * Note JPP requires double parentheses.
00819  */
00820 
00821 #ifdef HAVE_PROTOTYPES
00822 #define JPP(arglist)    arglist
00823 #else
00824 #define JPP(arglist)    ()
00825 #endif
00826 
00827 
00828 /* Short forms of external names for systems with brain-damaged linkers.
00829  * We shorten external names to be unique in the first six letters, which
00830  * is good enough for all known systems.
00831  * (If your compiler itself needs names to be unique in less than 15 
00832  * characters, you are out of luck.  Get a better compiler.)
00833  */
00834 
00835 #ifdef NEED_SHORT_EXTERNAL_NAMES
00836 #define jpeg_std_error      jStdError
00837 #define jpeg_CreateCompress jCreaCompress
00838 #define jpeg_CreateDecompress   jCreaDecompress
00839 #define jpeg_destroy_compress   jDestCompress
00840 #define jpeg_destroy_decompress jDestDecompress
00841 #define jpeg_stdio_dest     jStdDest
00842 #define jpeg_stdio_src      jStdSrc
00843 #define jpeg_set_defaults   jSetDefaults
00844 #define jpeg_set_colorspace jSetColorspace
00845 #define jpeg_default_colorspace jDefColorspace
00846 #define jpeg_set_quality    jSetQuality
00847 #define jpeg_set_linear_quality jSetLQuality
00848 #define jpeg_add_quant_table    jAddQuantTable
00849 #define jpeg_quality_scaling    jQualityScaling
00850 #define jpeg_simple_progression jSimProgress
00851 #define jpeg_suppress_tables    jSuppressTables
00852 #define jpeg_alloc_quant_table  jAlcQTable
00853 #define jpeg_alloc_huff_table   jAlcHTable
00854 #define jpeg_start_compress jStrtCompress
00855 #define jpeg_write_scanlines    jWrtScanlines
00856 #define jpeg_finish_compress    jFinCompress
00857 #define jpeg_write_raw_data jWrtRawData
00858 #define jpeg_write_marker   jWrtMarker
00859 #define jpeg_write_m_header jWrtMHeader
00860 #define jpeg_write_m_byte   jWrtMByte
00861 #define jpeg_write_tables   jWrtTables
00862 #define jpeg_read_header    jReadHeader
00863 #define jpeg_start_decompress   jStrtDecompress
00864 #define jpeg_read_scanlines jReadScanlines
00865 #define jpeg_finish_decompress  jFinDecompress
00866 #define jpeg_read_raw_data  jReadRawData
00867 #define jpeg_has_multiple_scans jHasMultScn
00868 #define jpeg_start_output   jStrtOutput
00869 #define jpeg_finish_output  jFinOutput
00870 #define jpeg_input_complete jInComplete
00871 #define jpeg_new_colormap   jNewCMap
00872 #define jpeg_consume_input  jConsumeInput
00873 #define jpeg_calc_output_dimensions jCalcDimensions
00874 #define jpeg_save_markers   jSaveMarkers
00875 #define jpeg_set_marker_processor   jSetMarker
00876 #define jpeg_read_coefficients  jReadCoefs
00877 #define jpeg_write_coefficients jWrtCoefs
00878 #define jpeg_copy_critical_parameters   jCopyCrit
00879 #define jpeg_abort_compress jAbrtCompress
00880 #define jpeg_abort_decompress   jAbrtDecompress
00881 #define jpeg_abort      jAbort
00882 #define jpeg_destroy        jDestroy
00883 #define jpeg_resync_to_restart  jResyncRestart
00884 #endif /* NEED_SHORT_EXTERNAL_NAMES */
00885 
00886 
00887 /* Default error-management setup */
00888 EXTERN(struct jpeg_error_mgr *) jpeg_std_error
00889     JPP((struct jpeg_error_mgr * err));
00890 
00891 /* Initialization of JPEG compression objects.
00892  * jpeg_create_compress() and jpeg_create_decompress() are the exported
00893  * names that applications should call.  These expand to calls on
00894  * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
00895  * passed for version mismatch checking.
00896  * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
00897  */
00898 #define jpeg_create_compress(cinfo) \
00899     jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
00900             (size_t) sizeof(struct jpeg_compress_struct))
00901 #define jpeg_create_decompress(cinfo) \
00902     jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
00903               (size_t) sizeof(struct jpeg_decompress_struct))
00904 EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo,
00905                       int version, size_t structsize));
00906 EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo,
00907                     int version, size_t structsize));
00908 /* Destruction of JPEG compression objects */
00909 EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo));
00910 EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
00911 
00912 /* Standard data source and destination managers: stdio streams. */
00913 /* Caller is responsible for opening the file before and closing after. */
00914 EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
00915 EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile));
00916 
00917 /* Default parameter setup for compression */
00918 EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo));
00919 /* Compression parameter setup aids */
00920 EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo,
00921                       J_COLOR_SPACE colorspace));
00922 EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo));
00923 EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
00924                    boolean force_baseline));
00925 EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
00926                       int scale_factor,
00927                       boolean force_baseline));
00928 EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
00929                        const unsigned int *basic_table,
00930                        int scale_factor,
00931                        boolean force_baseline));
00932 EXTERN(int) jpeg_quality_scaling JPP((int quality));
00933 EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo));
00934 EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo,
00935                        boolean suppress));
00936 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo));
00937 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo));
00938 
00939 /* Main entry points for compression */
00940 EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo,
00941                       boolean write_all_tables));
00942 EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo,
00943                          JSAMPARRAY scanlines,
00944                          JDIMENSION num_lines));
00945 EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo));
00946 
00947 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
00948 EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo,
00949                         JSAMPIMAGE data,
00950                         JDIMENSION num_lines));
00951 
00952 /* Write a special marker.  See libjpeg.doc concerning safe usage. */
00953 EXTERN(void) jpeg_write_marker
00954     JPP((j_compress_ptr cinfo, int marker,
00955          const JOCTET * dataptr, unsigned int datalen));
00956 /* Same, but piecemeal. */
00957 EXTERN(void) jpeg_write_m_header
00958     JPP((j_compress_ptr cinfo, int marker, unsigned int datalen));
00959 EXTERN(void) jpeg_write_m_byte
00960     JPP((j_compress_ptr cinfo, int val));
00961 
00962 /* Alternate compression function: just write an abbreviated table file */
00963 EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo));
00964 
00965 /* Decompression startup: read start of JPEG datastream to see what's there */
00966 EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo,
00967                   boolean require_image));
00968 /* Return value is one of: */
00969 #define JPEG_SUSPENDED      0 /* Suspended due to lack of input data */
00970 #define JPEG_HEADER_OK      1 /* Found valid image datastream */
00971 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
00972 /* If you pass require_image = TRUE (normal case), you need not check for
00973  * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
00974  * JPEG_SUSPENDED is only possible if you use a data source module that can
00975  * give a suspension return (the stdio source module doesn't).
00976  */
00977 
00978 /* Main entry points for decompression */
00979 EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo));
00980 EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
00981                         JSAMPARRAY scanlines,
00982                         JDIMENSION max_lines));
00983 EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
00984 
00985 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
00986 EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
00987                        JSAMPIMAGE data,
00988                        JDIMENSION max_lines));
00989 
00990 /* Additional entry points for buffered-image mode. */
00991 EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
00992 EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo,
00993                        int scan_number));
00994 EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo));
00995 EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo));
00996 EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo));
00997 EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo));
00998 /* Return value is one of: */
00999 /* #define JPEG_SUSPENDED   0    Suspended due to lack of input data */
01000 #define JPEG_REACHED_SOS    1 /* Reached start of new scan */
01001 #define JPEG_REACHED_EOI    2 /* Reached end of image */
01002 #define JPEG_ROW_COMPLETED  3 /* Completed one iMCU row */
01003 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
01004 
01005 /* Precalculate output dimensions for current decompression parameters. */
01006 EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo));
01007 
01008 /* Control saving of COM and APPn markers into marker_list. */
01009 EXTERN(void) jpeg_save_markers
01010     JPP((j_decompress_ptr cinfo, int marker_code,
01011          unsigned int length_limit));
01012 
01013 /* Install a special processing method for COM or APPn markers. */
01014 EXTERN(void) jpeg_set_marker_processor
01015     JPP((j_decompress_ptr cinfo, int marker_code,
01016          jpeg_marker_parser_method routine));
01017 
01018 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
01019 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo));
01020 EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo,
01021                       jvirt_barray_ptr * coef_arrays));
01022 EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo,
01023                         j_compress_ptr dstinfo));
01024 
01025 /* If you choose to abort compression or decompression before completing
01026  * jpeg_finish_(de)compress, then you need to clean up to release memory,
01027  * temporary files, etc.  You can just call jpeg_destroy_(de)compress
01028  * if you're done with the JPEG object, but if you want to clean it up and
01029  * reuse it, call this:
01030  */
01031 EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo));
01032 EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo));
01033 
01034 /* Generic versions of jpeg_abort and jpeg_destroy that work on either
01035  * flavor of JPEG object.  These may be more convenient in some places.
01036  */
01037 EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo));
01038 EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo));
01039 
01040 /* Default restart-marker-resync procedure for use by data source modules */
01041 EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo,
01042                         int desired));
01043 
01044 
01045 /* These marker codes are exported since applications and data source modules
01046  * are likely to want to use them.
01047  */
01048 
01049 #define JPEG_RST0   0xD0    /* RST0 marker code */
01050 #define JPEG_EOI    0xD9    /* EOI marker code */
01051 #define JPEG_APP0   0xE0    /* APP0 marker code */
01052 #define JPEG_COM    0xFE    /* COM marker code */
01053 
01054 
01055 /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
01056  * for structure definitions that are never filled in, keep it quiet by
01057  * supplying dummy definitions for the various substructures.
01058  */
01059 
01060 #ifdef INCOMPLETE_TYPES_BROKEN
01061 #ifndef JPEG_INTERNALS      /* will be defined in jpegint.h */
01062 struct jvirt_sarray_control { long dummy; };
01063 struct jvirt_barray_control { long dummy; };
01064 struct jpeg_comp_master { long dummy; };
01065 struct jpeg_c_main_controller { long dummy; };
01066 struct jpeg_c_prep_controller { long dummy; };
01067 struct jpeg_c_coef_controller { long dummy; };
01068 struct jpeg_marker_writer { long dummy; };
01069 struct jpeg_color_converter { long dummy; };
01070 struct jpeg_downsampler { long dummy; };
01071 struct jpeg_forward_dct { long dummy; };
01072 struct jpeg_entropy_encoder { long dummy; };
01073 struct jpeg_decomp_master { long dummy; };
01074 struct jpeg_d_main_controller { long dummy; };
01075 struct jpeg_d_coef_controller { long dummy; };
01076 struct jpeg_d_post_controller { long dummy; };
01077 struct jpeg_input_controller { long dummy; };
01078 struct jpeg_marker_reader { long dummy; };
01079 struct jpeg_entropy_decoder { long dummy; };
01080 struct jpeg_inverse_dct { long dummy; };
01081 struct jpeg_upsampler { long dummy; };
01082 struct jpeg_color_deconverter { long dummy; };
01083 struct jpeg_color_quantizer { long dummy; };
01084 #endif /* JPEG_INTERNALS */
01085 #endif /* INCOMPLETE_TYPES_BROKEN */
01086 
01087 
01088 /*
01089  * The JPEG library modules define JPEG_INTERNALS before including this file.
01090  * The internal structure declarations are read only when that is true.
01091  * Applications using the library should not include jpegint.h, but may wish
01092  * to include jerror.h.
01093  */
01094 
01095 #ifdef JPEG_INTERNALS
01096 #include "jpegint.h"        /* fetch private declarations */
01097 #include "jerror.h"     /* fetch error codes too */
01098 #endif
01099 
01100 #endif /* JPEGLIB_H */

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