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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 
00016 /*
00017  * First we include the configuration files that record how this
00018  * installation of the JPEG library is set up.  jconfig.h can be
00019  * generated automatically for many systems.  jmorecfg.h contains
00020  * manual configuration options that most people need not worry about.
00021  */
00022 
00023 #ifndef JCONFIG_INCLUDED    /* in case jinclude.h already did */
00024 #include "jconfig.h"        /* widely used configuration options */
00025 #endif
00026 #include "jmorecfg.h"              /* seldom changed options */
00027 
00028 
00029 /* Version ID for the JPEG library.
00030  * Might be useful for tests like "#if JPEG_LIB_VERSION >= 60".
00031  */
00032 
00033 #define JPEG_LIB_VERSION  62       /* Version 6b */
00034 
00035 
00036 /* Various constants determining the sizes of things.
00037  * All of these are specified by the JPEG standard, so don't change them
00038  * if you want to be compatible.
00039  */
00040 
00041 #define DCTSIZE                 8  /* The basic DCT block is 8x8 samples */
00042 #define DCTSIZE2         64 /* DCTSIZE squared; # of elements in a block */
00043 #define NUM_QUANT_TBLS      4      /* Quantization tables are numbered 0..3 */
00044 #define NUM_HUFF_TBLS       4      /* Huffman tables are numbered 0..3 */
00045 #define NUM_ARITH_TBLS      16     /* Arith-coding tables are numbered 0..15 */
00046 #define MAX_COMPS_IN_SCAN   4      /* JPEG limit on # of components in one scan */
00047 #define MAX_SAMP_FACTOR     4      /* JPEG limit on sampling factors */
00048 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
00049  * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
00050  * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
00051  * to handle it.  We even let you do this from the jconfig.h file.  However,
00052  * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
00053  * sometimes emits noncompliant files doesn't mean you should too.
00054  */
00055 #define C_MAX_BLOCKS_IN_MCU   10 /* compressor's limit on blocks per MCU */
00056 #ifndef D_MAX_BLOCKS_IN_MCU
00057 #define D_MAX_BLOCKS_IN_MCU   10 /* decompressor's limit on blocks per MCU */
00058 #endif
00059 
00060 
00061 /* Data structures for images (arrays of samples and of DCT coefficients).
00062  * On 80x86 machines, the image arrays are too big for near pointers,
00063  * but the pointer arrays can fit in near memory.
00064  */
00065 
00066 typedef JSAMPLE FAR *JSAMPROW;     /* ptr to one image row of pixel samples. */
00067 typedef JSAMPROW *JSAMPARRAY;      /* ptr to some rows (a 2-D sample array) */
00068 typedef JSAMPARRAY *JSAMPIMAGE;    /* a 3-D sample array: top index is color */
00069 
00070 typedef JCOEF JBLOCK[DCTSIZE2];    /* one block of coefficients */
00071 typedef JBLOCK FAR *JBLOCKROW;     /* pointer to one row of coefficient blocks */
00072 typedef JBLOCKROW *JBLOCKARRAY;           /* a 2-D array of coefficient blocks */
00073 typedef JBLOCKARRAY *JBLOCKIMAGE;  /* a 3-D array of coefficient blocks */
00074 
00075 typedef JCOEF FAR *JCOEFPTR;       /* useful in a couple of places */
00076 
00077 
00078 /* Types for JPEG compression parameters and working tables. */
00079 
00080 
00081 /* DCT coefficient quantization tables. */
00082 
00083 typedef struct {
00084   /* This array gives the coefficient quantizers in natural array order
00085    * (not the zigzag order in which they are stored in a JPEG DQT marker).
00086    * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
00087    */
00088   UINT16 quantval[DCTSIZE2];       /* quantization step for each coefficient */
00089   /* This field is used only during compression.  It's initialized FALSE when
00090    * the table is created, and set TRUE when it's been output to the file.
00091    * You could suppress output of a table by setting this to TRUE.
00092    * (See jpeg_suppress_tables for an example.)
00093    */
00094   boolean sent_table;              /* TRUE when table has been output */
00095 } JQUANT_TBL;
00096 
00097 
00098 /* Huffman coding tables. */
00099 
00100 typedef struct {
00101   /* These two fields directly represent the contents of a JPEG DHT marker */
00102   UINT8 bits[17];           /* bits[k] = # of symbols with codes of */
00103                             /* length k bits; bits[0] is unused */
00104   UINT8 huffval[256];              /* The symbols, in order of incr code length */
00105   /* This field is used only during compression.  It's initialized FALSE when
00106    * the table is created, and set TRUE when it's been output to the file.
00107    * You could suppress output of a table by setting this to TRUE.
00108    * (See jpeg_suppress_tables for an example.)
00109    */
00110   boolean sent_table;              /* TRUE when table has been output */
00111 } JHUFF_TBL;
00112 
00113 
00114 /* Basic info about one component (color channel). */
00115 
00116 typedef struct {
00117   /* These values are fixed over the whole image. */
00118   /* For compression, they must be supplied by parameter setup; */
00119   /* for decompression, they are read from the SOF marker. */
00120   int component_id;         /* identifier for this component (0..255) */
00121   int component_index;             /* its index in SOF or cinfo->comp_info[] */
00122   int h_samp_factor;        /* horizontal sampling factor (1..4) */
00123   int v_samp_factor;        /* vertical sampling factor (1..4) */
00124   int quant_tbl_no;         /* quantization table selector (0..3) */
00125   /* These values may vary between scans. */
00126   /* For compression, they must be supplied by parameter setup; */
00127   /* for decompression, they are read from the SOS marker. */
00128   /* The decompressor output side may not use these variables. */
00129   int dc_tbl_no;            /* DC entropy table selector (0..3) */
00130   int ac_tbl_no;            /* AC entropy table selector (0..3) */
00131   
00132   /* Remaining fields should be treated as private by applications. */
00133   
00134   /* These values are computed during compression or decompression startup: */
00135   /* Component's size in DCT blocks.
00136    * Any dummy blocks added to complete an MCU are not counted; therefore
00137    * these values do not depend on whether a scan is interleaved or not.
00138    */
00139   JDIMENSION width_in_blocks;
00140   JDIMENSION height_in_blocks;
00141   /* Size of a DCT block in samples.  Always DCTSIZE for compression.
00142    * For decompression this is the size of the output from one DCT block,
00143    * reflecting any scaling we choose to apply during the IDCT step.
00144    * Values of 1,2,4,8 are likely to be supported.  Note that different
00145    * components may receive different IDCT scalings.
00146    */
00147   int DCT_scaled_size;
00148   /* The downsampled dimensions are the component's actual, unpadded number
00149    * of samples at the main buffer (preprocessing/compression interface), thus
00150    * downsampled_width = ceil(image_width * Hi/Hmax)
00151    * and similarly for height.  For decompression, IDCT scaling is included, so
00152    * downsampled_width = ceil(image_width * Hi/Hmax * DCT_scaled_size/DCTSIZE)
00153    */
00154   JDIMENSION downsampled_width;     /* actual width in samples */
00155   JDIMENSION downsampled_height; /* actual height in samples */
00156   /* This flag is used only for decompression.  In cases where some of the
00157    * components will be ignored (eg grayscale output from YCbCr image),
00158    * we can skip most computations for the unused components.
00159    */
00160   boolean component_needed; /* do we need the value of this component? */
00161 
00162   /* These values are computed before starting a scan of the component. */
00163   /* The decompressor output side may not use these variables. */
00164   int MCU_width;            /* number of blocks per MCU, horizontally */
00165   int MCU_height;           /* number of blocks per MCU, vertically */
00166   int MCU_blocks;           /* MCU_width * MCU_height */
00167   int MCU_sample_width;            /* MCU width in samples, MCU_width*DCT_scaled_size */
00168   int last_col_width;              /* # of non-dummy blocks across in last MCU */
00169   int last_row_height;             /* # of non-dummy blocks down in last MCU */
00170 
00171   /* Saved quantization table for component; NULL if none yet saved.
00172    * See jdinput.c comments about the need for this information.
00173    * This field is currently used only for decompression.
00174    */
00175   JQUANT_TBL * quant_table;
00176 
00177   /* Private per-component storage for DCT or IDCT subsystem. */
00178   void * dct_table;
00179 } jpeg_component_info;
00180 
00181 
00182 /* The script for encoding a multiple-scan file is an array of these: */
00183 
00184 typedef struct {
00185   int comps_in_scan;        /* number of components encoded in this scan */
00186   int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
00187   int Ss, Se;               /* progressive JPEG spectral selection parms */
00188   int Ah, Al;               /* progressive JPEG successive approx. parms */
00189 } jpeg_scan_info;
00190 
00191 /* The decompressor can save APPn and COM markers in a list of these: */
00192 
00193 typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr;
00194 
00195 struct jpeg_marker_struct {
00196   jpeg_saved_marker_ptr next;      /* next in list, or NULL */
00197   UINT8 marker;                    /* marker code: JPEG_COM, or JPEG_APP0+n */
00198   unsigned int original_length;    /* # bytes of data in the file */
00199   unsigned int data_length; /* # bytes of data saved at data[] */
00200   JOCTET FAR * data;        /* the data contained in the marker */
00201   /* the marker length word is not counted in data_length or original_length */
00202 };
00203 
00204 /* Known color spaces. */
00205 
00206 typedef enum {
00207        JCS_UNKNOWN,         /* error/unspecified */
00208        JCS_GRAYSCALE,              /* monochrome */
00209        JCS_RGB,             /* red/green/blue */
00210        JCS_YCbCr,           /* Y/Cb/Cr (also known as YUV) */
00211        JCS_CMYK,            /* C/M/Y/K */
00212        JCS_YCCK             /* Y/Cb/Cr/K */
00213 } J_COLOR_SPACE;
00214 
00215 /* DCT/IDCT algorithm options. */
00216 
00217 typedef enum {
00218        JDCT_ISLOW,          /* slow but accurate integer algorithm */
00219        JDCT_IFAST,          /* faster, less accurate integer method */
00220        JDCT_FLOAT           /* floating-point: accurate, fast on fast HW */
00221 } J_DCT_METHOD;
00222 
00223 #ifndef JDCT_DEFAULT        /* may be overridden in jconfig.h */
00224 #define JDCT_DEFAULT  JDCT_ISLOW
00225 #endif
00226 #ifndef JDCT_FASTEST        /* may be overridden in jconfig.h */
00227 #define JDCT_FASTEST  JDCT_IFAST
00228 #endif
00229 
00230 /* Dithering options for decompression. */
00231 
00232 typedef enum {
00233        JDITHER_NONE,        /* no dithering */
00234        JDITHER_ORDERED,     /* simple ordered dither */
00235        JDITHER_FS           /* Floyd-Steinberg error diffusion dither */
00236 } J_DITHER_MODE;
00237 
00238 
00239 /* Common fields between JPEG compression and decompression master structs. */
00240 
00241 #define jpeg_common_fields \
00242   struct jpeg_error_mgr * err;     /* Error handler module */\
00243   struct jpeg_memory_mgr * mem;    /* Memory manager module */\
00244   struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
00245   void * client_data;              /* Available for use by application */\
00246   boolean is_decompressor;  /* So common code can tell which is which */\
00247   int global_state          /* For checking call sequence validity */
00248 
00249 /* Routines that are to be used by both halves of the library are declared
00250  * to receive a pointer to this structure.  There are no actual instances of
00251  * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
00252  */
00253 struct jpeg_common_struct {
00254   jpeg_common_fields;              /* Fields common to both master struct types */
00255   /* Additional fields follow in an actual jpeg_compress_struct or
00256    * jpeg_decompress_struct.  All three structs must agree on these
00257    * initial fields!  (This would be a lot cleaner in C++.)
00258    */
00259 };
00260 
00261 typedef struct jpeg_common_struct * j_common_ptr;
00262 typedef struct jpeg_compress_struct * j_compress_ptr;
00263 typedef struct jpeg_decompress_struct * j_decompress_ptr;
00264 
00265 
00266 /* Master record for a compression instance */
00267 
00268 struct jpeg_compress_struct {
00269   jpeg_common_fields;              /* Fields shared with jpeg_decompress_struct */
00270 
00271   /* Destination for compressed data */
00272   struct jpeg_destination_mgr * dest;
00273 
00274   /* Description of source image --- these fields must be filled in by
00275    * outer application before starting compression.  in_color_space must
00276    * be correct before you can even call jpeg_set_defaults().
00277    */
00278 
00279   JDIMENSION image_width;   /* input image width */
00280   JDIMENSION image_height;  /* input image height */
00281   int input_components;            /* # of color components in input image */
00282   J_COLOR_SPACE in_color_space;    /* colorspace of input image */
00283 
00284   double input_gamma;              /* image gamma of input image */
00285 
00286   /* Compression parameters --- these fields must be set before calling
00287    * jpeg_start_compress().  We recommend calling jpeg_set_defaults() to
00288    * initialize everything to reasonable defaults, then changing anything
00289    * the application specifically wants to change.  That way you won't get
00290    * burnt when new parameters are added.  Also note that there are several
00291    * helper routines to simplify changing parameters.
00292    */
00293 
00294   int data_precision;              /* bits of precision in image data */
00295 
00296   int num_components;              /* # of color components in JPEG image */
00297   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
00298 
00299   jpeg_component_info * comp_info;
00300   /* comp_info[i] describes component that appears i'th in SOF */
00301   
00302   JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
00303   /* ptrs to coefficient quantization tables, or NULL if not defined */
00304   
00305   JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
00306   JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
00307   /* ptrs to Huffman coding tables, or NULL if not defined */
00308   
00309   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
00310   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
00311   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
00312 
00313   int num_scans;            /* # of entries in scan_info array */
00314   const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */
00315   /* The default value of scan_info is NULL, which causes a single-scan
00316    * sequential JPEG file to be emitted.  To create a multi-scan file,
00317    * set num_scans and scan_info to point to an array of scan definitions.
00318    */
00319 
00320   boolean raw_data_in;             /* TRUE=caller supplies downsampled data */
00321   boolean arith_code;              /* TRUE=arithmetic coding, FALSE=Huffman */
00322   boolean optimize_coding;  /* TRUE=optimize entropy encoding parms */
00323   boolean CCIR601_sampling; /* TRUE=first samples are cosited */
00324   int smoothing_factor;            /* 1..100, or 0 for no input smoothing */
00325   J_DCT_METHOD dct_method;  /* DCT algorithm selector */
00326 
00327   /* The restart interval can be specified in absolute MCUs by setting
00328    * restart_interval, or in MCU rows by setting restart_in_rows
00329    * (in which case the correct restart_interval will be figured
00330    * for each scan).
00331    */
00332   unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
00333   int restart_in_rows;             /* if > 0, MCU rows per restart interval */
00334 
00335   /* Parameters controlling emission of special markers. */
00336 
00337   boolean write_JFIF_header;       /* should a JFIF marker be written? */
00338   UINT8 JFIF_major_version; /* What to write for the JFIF version number */
00339   UINT8 JFIF_minor_version;
00340   /* These three values are not used by the JPEG code, merely copied */
00341   /* into the JFIF APP0 marker.  density_unit can be 0 for unknown, */
00342   /* 1 for dots/inch, or 2 for dots/cm.  Note that the pixel aspect */
00343   /* ratio is defined by X_density/Y_density even when density_unit=0. */
00344   UINT8 density_unit;              /* JFIF code for pixel size units */
00345   UINT16 X_density;         /* Horizontal pixel density */
00346   UINT16 Y_density;         /* Vertical pixel density */
00347   boolean write_Adobe_marker;      /* should an Adobe marker be written? */
00348   
00349   /* State variable: index of next scanline to be written to
00350    * jpeg_write_scanlines().  Application may use this to control its
00351    * processing loop, e.g., "while (next_scanline < image_height)".
00352    */
00353 
00354   JDIMENSION next_scanline; /* 0 .. image_height-1  */
00355 
00356   /* Remaining fields are known throughout compressor, but generally
00357    * should not be touched by a surrounding application.
00358    */
00359 
00360   /*
00361    * These fields are computed during compression startup
00362    */
00363   boolean progressive_mode; /* TRUE if scan script uses progressive mode */
00364   int max_h_samp_factor;    /* largest h_samp_factor */
00365   int max_v_samp_factor;    /* largest v_samp_factor */
00366 
00367   JDIMENSION total_iMCU_rows;      /* # of iMCU rows to be input to coef ctlr */
00368   /* The coefficient controller receives data in units of MCU rows as defined
00369    * for fully interleaved scans (whether the JPEG file is interleaved or not).
00370    * There are v_samp_factor * DCTSIZE sample rows of each component in an
00371    * "iMCU" (interleaved MCU) row.
00372    */
00373   
00374   /*
00375    * These fields are valid during any one scan.
00376    * They describe the components and MCUs actually appearing in the scan.
00377    */
00378   int comps_in_scan;        /* # of JPEG components in this scan */
00379   jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
00380   /* *cur_comp_info[i] describes component that appears i'th in SOS */
00381   
00382   JDIMENSION MCUs_per_row;  /* # of MCUs across the image */
00383   JDIMENSION MCU_rows_in_scan;     /* # of MCU rows in the image */
00384   
00385   int blocks_in_MCU;        /* # of DCT blocks per MCU */
00386   int MCU_membership[C_MAX_BLOCKS_IN_MCU];
00387   /* MCU_membership[i] is index in cur_comp_info of component owning */
00388   /* i'th block in an MCU */
00389 
00390   int Ss, Se, Ah, Al;              /* progressive JPEG parameters for scan */
00391 
00392   /*
00393    * Links to compression subobjects (methods and private variables of modules)
00394    */
00395   struct jpeg_comp_master * master;
00396   struct jpeg_c_main_controller * main;
00397   struct jpeg_c_prep_controller * prep;
00398   struct jpeg_c_coef_controller * coef;
00399   struct jpeg_marker_writer * marker;
00400   struct jpeg_color_converter * cconvert;
00401   struct jpeg_downsampler * downsample;
00402   struct jpeg_forward_dct * fdct;
00403   struct jpeg_entropy_encoder * entropy;
00404   jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */
00405   int script_space_size;
00406 };
00407 
00408 
00409 /* Master record for a decompression instance */
00410 
00411 struct jpeg_decompress_struct {
00412   jpeg_common_fields;              /* Fields shared with jpeg_compress_struct */
00413 
00414   /* Source of compressed data */
00415   struct jpeg_source_mgr * src;
00416 
00417   /* Basic description of image --- filled in by jpeg_read_header(). */
00418   /* Application may inspect these values to decide how to process image. */
00419 
00420   JDIMENSION image_width;   /* nominal image width (from SOF marker) */
00421   JDIMENSION image_height;  /* nominal image height */
00422   int num_components;              /* # of color components in JPEG image */
00423   J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
00424 
00425   /* Decompression processing parameters --- these fields must be set before
00426    * calling jpeg_start_decompress().  Note that jpeg_read_header() initializes
00427    * them to default values.
00428    */
00429 
00430   J_COLOR_SPACE out_color_space; /* colorspace for output */
00431 
00432   unsigned int scale_num, scale_denom; /* fraction by which to scale image */
00433 
00434   double output_gamma;             /* image gamma wanted in output */
00435 
00436   boolean buffered_image;   /* TRUE=multiple output passes */
00437   boolean raw_data_out;            /* TRUE=downsampled data wanted */
00438 
00439   J_DCT_METHOD dct_method;  /* IDCT algorithm selector */
00440   boolean do_fancy_upsampling;     /* TRUE=apply fancy upsampling */
00441   boolean do_block_smoothing;      /* TRUE=apply interblock smoothing */
00442 
00443   boolean quantize_colors;  /* TRUE=colormapped output wanted */
00444   /* the following are ignored if not quantize_colors: */
00445   J_DITHER_MODE dither_mode;       /* type of color dithering to use */
00446   boolean two_pass_quantize;       /* TRUE=use two-pass color quantization */
00447   int desired_number_of_colors;    /* max # colors to use in created colormap */
00448   /* these are significant only in buffered-image mode: */
00449   boolean enable_1pass_quant;      /* enable future use of 1-pass quantizer */
00450   boolean enable_external_quant;/* enable future use of external colormap */
00451   boolean enable_2pass_quant;      /* enable future use of 2-pass quantizer */
00452 
00453   /* Description of actual output image that will be returned to application.
00454    * These fields are computed by jpeg_start_decompress().
00455    * You can also use jpeg_calc_output_dimensions() to determine these values
00456    * in advance of calling jpeg_start_decompress().
00457    */
00458 
00459   JDIMENSION output_width;  /* scaled image width */
00460   JDIMENSION output_height; /* scaled image height */
00461   int out_color_components; /* # of color components in out_color_space */
00462   int output_components;    /* # of color components returned */
00463   /* output_components is 1 (a colormap index) when quantizing colors;
00464    * otherwise it equals out_color_components.
00465    */
00466   int rec_outbuf_height;    /* min recommended height of scanline buffer */
00467   /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
00468    * high, space and time will be wasted due to unnecessary data copying.
00469    * Usually rec_outbuf_height will be 1 or 2, at most 4.
00470    */
00471 
00472   /* When quantizing colors, the output colormap is described by these fields.
00473    * The application can supply a colormap by setting colormap non-NULL before
00474    * calling jpeg_start_decompress; otherwise a colormap is created during
00475    * jpeg_start_decompress or jpeg_start_output.
00476    * The map has out_color_components rows and actual_number_of_colors columns.
00477    */
00478   int actual_number_of_colors;     /* number of entries in use */
00479   JSAMPARRAY colormap;             /* The color map as a 2-D pixel array */
00480 
00481   /* State variables: these variables indicate the progress of decompression.
00482    * The application may examine these but must not modify them.
00483    */
00484 
00485   /* Row index of next scanline to be read from jpeg_read_scanlines().
00486    * Application may use this to control its processing loop, e.g.,
00487    * "while (output_scanline < output_height)".
00488    */
00489   JDIMENSION output_scanline;      /* 0 .. output_height-1  */
00490 
00491   /* Current input scan number and number of iMCU rows completed in scan.
00492    * These indicate the progress of the decompressor input side.
00493    */
00494   int input_scan_number;    /* Number of SOS markers seen so far */
00495   JDIMENSION input_iMCU_row;       /* Number of iMCU rows completed */
00496 
00497   /* The "output scan number" is the notional scan being displayed by the
00498    * output side.  The decompressor will not allow output scan/row number
00499    * to get ahead of input scan/row, but it can fall arbitrarily far behind.
00500    */
00501   int output_scan_number;   /* Nominal scan number being displayed */
00502   JDIMENSION output_iMCU_row;      /* Number of iMCU rows read */
00503 
00504   /* Current progression status.  coef_bits[c][i] indicates the precision
00505    * with which component c's DCT coefficient i (in zigzag order) is known.
00506    * It is -1 when no data has yet been received, otherwise it is the point
00507    * transform (shift) value for the most recent scan of the coefficient
00508    * (thus, 0 at completion of the progression).
00509    * This pointer is NULL when reading a non-progressive file.
00510    */
00511   int (*coef_bits)[DCTSIZE2];      /* -1 or current Al value for each coef */
00512 
00513   /* Internal JPEG parameters --- the application usually need not look at
00514    * these fields.  Note that the decompressor output side may not use
00515    * any parameters that can change between scans.
00516    */
00517 
00518   /* Quantization and Huffman tables are carried forward across input
00519    * datastreams when processing abbreviated JPEG datastreams.
00520    */
00521 
00522   JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
00523   /* ptrs to coefficient quantization tables, or NULL if not defined */
00524 
00525   JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
00526   JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
00527   /* ptrs to Huffman coding tables, or NULL if not defined */
00528 
00529   /* These parameters are never carried across datastreams, since they
00530    * are given in SOF/SOS markers or defined to be reset by SOI.
00531    */
00532 
00533   int data_precision;              /* bits of precision in image data */
00534 
00535   jpeg_component_info * comp_info;
00536   /* comp_info[i] describes component that appears i'th in SOF */
00537 
00538   boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
00539   boolean arith_code;              /* TRUE=arithmetic coding, FALSE=Huffman */
00540 
00541   UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
00542   UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
00543   UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
00544 
00545   unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
00546 
00547   /* These fields record data obtained from optional markers recognized by
00548    * the JPEG library.
00549    */
00550   boolean saw_JFIF_marker;  /* TRUE iff a JFIF APP0 marker was found */
00551   /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
00552   UINT8 JFIF_major_version; /* JFIF version number */
00553   UINT8 JFIF_minor_version;
00554   UINT8 density_unit;              /* JFIF code for pixel size units */
00555   UINT16 X_density;         /* Horizontal pixel density */
00556   UINT16 Y_density;         /* Vertical pixel density */
00557   boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
00558   UINT8 Adobe_transform;    /* Color transform code from Adobe marker */
00559 
00560   boolean CCIR601_sampling; /* TRUE=first samples are cosited */
00561 
00562   /* Aside from the specific data retained from APPn markers known to the
00563    * library, the uninterpreted contents of any or all APPn and COM markers
00564    * can be saved in a list for examination by the application.
00565    */
00566   jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
00567 
00568   /* Remaining fields are known throughout decompressor, but generally
00569    * should not be touched by a surrounding application.
00570    */
00571 
00572   /*
00573    * These fields are computed during decompression startup
00574    */
00575   int max_h_samp_factor;    /* largest h_samp_factor */
00576   int max_v_samp_factor;    /* largest v_samp_factor */
00577 
00578   int min_DCT_scaled_size;  /* smallest DCT_scaled_size of any component */
00579 
00580   JDIMENSION total_iMCU_rows;      /* # of iMCU rows in image */
00581   /* The coefficient controller's input and output progress is measured in
00582    * units of "iMCU" (interleaved MCU) rows.  These are the same as MCU rows
00583    * in fully interleaved JPEG scans, but are used whether the scan is
00584    * interleaved or not.  We define an iMCU row as v_samp_factor DCT block
00585    * rows of each component.  Therefore, the IDCT output contains
00586    * v_samp_factor*DCT_scaled_size sample rows of a component per iMCU row.
00587    */
00588 
00589   JSAMPLE * sample_range_limit; /* table for fast range-limiting */
00590 
00591   /*
00592    * These fields are valid during any one scan.
00593    * They describe the components and MCUs actually appearing in the scan.
00594    * Note that the decompressor output side must not use these fields.
00595    */
00596   int comps_in_scan;        /* # of JPEG components in this scan */
00597   jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
00598   /* *cur_comp_info[i] describes component that appears i'th in SOS */
00599 
00600   JDIMENSION MCUs_per_row;  /* # of MCUs across the image */
00601   JDIMENSION MCU_rows_in_scan;     /* # of MCU rows in the image */
00602 
00603   int blocks_in_MCU;        /* # of DCT blocks per MCU */
00604   int MCU_membership[D_MAX_BLOCKS_IN_MCU];
00605   /* MCU_membership[i] is index in cur_comp_info of component owning */
00606   /* i'th block in an MCU */
00607 
00608   int Ss, Se, Ah, Al;              /* progressive JPEG parameters for scan */
00609 
00610   /* This field is shared between entropy decoder and marker parser.
00611    * It is either zero or the code of a JPEG marker that has been
00612    * read from the data source, but has not yet been processed.
00613    */
00614   int unread_marker;
00615 
00616   /*
00617    * Links to decompression subobjects (methods, private variables of modules)
00618    */
00619   struct jpeg_decomp_master * master;
00620   struct jpeg_d_main_controller * main;
00621   struct jpeg_d_coef_controller * coef;
00622   struct jpeg_d_post_controller * post;
00623   struct jpeg_input_controller * inputctl;
00624   struct jpeg_marker_reader * marker;
00625   struct jpeg_entropy_decoder * entropy;
00626   struct jpeg_inverse_dct * idct;
00627   struct jpeg_upsampler * upsample;
00628   struct jpeg_color_deconverter * cconvert;
00629   struct jpeg_color_quantizer * cquantize;
00630 };
00631 
00632 
00633 /* "Object" declarations for JPEG modules that may be supplied or called
00634  * directly by the surrounding application.
00635  * As with all objects in the JPEG library, these structs only define the
00636  * publicly visible methods and state variables of a module.  Additional
00637  * private fields may exist after the public ones.
00638  */
00639 
00640 
00641 /* Error handler object */
00642 
00643 struct jpeg_error_mgr {
00644   /* Error exit handler: does not return to caller */
00645   JMETHOD(void, error_exit, (j_common_ptr cinfo));
00646   /* Conditionally emit a trace or warning message */
00647   JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
00648   /* Routine that actually outputs a trace or error message */
00649   JMETHOD(void, output_message, (j_common_ptr cinfo));
00650   /* Format a message string for the most recent JPEG error or message */
00651   JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
00652 #define JMSG_LENGTH_MAX  200       /* recommended size of format_message buffer */
00653   /* Reset error state variables at start of a new image */
00654   JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
00655   
00656   /* The message ID code and any parameters are saved here.
00657    * A message can have one string parameter or up to 8 int parameters.
00658    */
00659   int msg_code;
00660 #define JMSG_STR_PARM_MAX  80
00661   union {
00662     int i[8];
00663     char s[JMSG_STR_PARM_MAX];
00664   } msg_parm;
00665   
00666   /* Standard state variables for error facility */
00667   
00668   int trace_level;          /* max msg_level that will be displayed */
00669   
00670   /* For recoverable corrupt-data errors, we emit a warning message,
00671    * but keep going unless emit_message chooses to abort.  emit_message
00672    * should count warnings in num_warnings.  The surrounding application
00673    * can check for bad data by seeing if num_warnings is nonzero at the
00674    * end of processing.
00675    */
00676   long num_warnings;        /* number of corrupt-data warnings */
00677 
00678   /* These fields point to the table(s) of error message strings.
00679    * An application can change the table pointer to switch to a different
00680    * message list (typically, to change the language in which errors are
00681    * reported).  Some applications may wish to add additional error codes
00682    * that will be handled by the JPEG library error mechanism; the second
00683    * table pointer is used for this purpose.
00684    *
00685    * First table includes all errors generated by JPEG library itself.
00686    * Error code 0 is reserved for a "no such error string" message.
00687    */
00688   const char * const * jpeg_message_table; /* Library errors */
00689   int last_jpeg_message;    /* Table contains strings 0..last_jpeg_message */
00690   /* Second table can be added by application (see cjpeg/djpeg for example).
00691    * It contains strings numbered first_addon_message..last_addon_message.
00692    */
00693   const char * const * addon_message_table; /* Non-library errors */
00694   int first_addon_message;  /* code for first string in addon table */
00695   int last_addon_message;   /* code for last string in addon table */
00696 };
00697 
00698 
00699 /* Progress monitor object */
00700 
00701 struct jpeg_progress_mgr {
00702   JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
00703 
00704   long pass_counter;        /* work units completed in this pass */
00705   long pass_limit;          /* total number of work units in this pass */
00706   int completed_passes;            /* passes completed so far */
00707   int total_passes;         /* total number of passes expected */
00708 };
00709 
00710 
00711 /* Data destination object for compression */
00712 
00713 struct jpeg_destination_mgr {
00714   JOCTET * next_output_byte;       /* => next byte to write in buffer */
00715   size_t free_in_buffer;    /* # of byte spaces remaining in buffer */
00716 
00717   JMETHOD(void, init_destination, (j_compress_ptr cinfo));
00718   JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
00719   JMETHOD(void, term_destination, (j_compress_ptr cinfo));
00720 };
00721 
00722 
00723 /* Data source object for decompression */
00724 
00725 struct jpeg_source_mgr {
00726   const JOCTET * next_input_byte; /* => next byte to read from buffer */
00727   size_t bytes_in_buffer;   /* # of bytes remaining in buffer */
00728 
00729   JMETHOD(void, init_source, (j_decompress_ptr cinfo));
00730   JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
00731   JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
00732   JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
00733   JMETHOD(void, term_source, (j_decompress_ptr cinfo));
00734 };
00735 
00736 
00737 /* Memory manager object.
00738  * Allocates "small" objects (a few K total), "large" objects (tens of K),
00739  * and "really big" objects (virtual arrays with backing store if needed).
00740  * The memory manager does not allow individual objects to be freed; rather,
00741  * each created object is assigned to a pool, and whole pools can be freed
00742  * at once.  This is faster and more convenient than remembering exactly what
00743  * to free, especially where malloc()/free() are not too speedy.
00744  * NB: alloc routines never return NULL.  They exit to error_exit if not
00745  * successful.
00746  */
00747 
00748 #define JPOOL_PERMANENT     0      /* lasts until master record is destroyed */
00749 #define JPOOL_IMAGE  1      /* lasts until done with image/datastream */
00750 #define JPOOL_NUMPOOLS      2
00751 
00752 typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
00753 typedef struct jvirt_barray_control * jvirt_barray_ptr;
00754 
00755 
00756 struct jpeg_memory_mgr {
00757   /* Method pointers */
00758   JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
00759                             size_t sizeofobject));
00760   JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
00761                                  size_t sizeofobject));
00762   JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
00763                                  JDIMENSION samplesperrow,
00764                                  JDIMENSION numrows));
00765   JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
00766                                   JDIMENSION blocksperrow,
00767                                   JDIMENSION numrows));
00768   JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
00769                                             int pool_id,
00770                                             boolean pre_zero,
00771                                             JDIMENSION samplesperrow,
00772                                             JDIMENSION numrows,
00773                                             JDIMENSION maxaccess));
00774   JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
00775                                             int pool_id,
00776                                             boolean pre_zero,
00777                                             JDIMENSION blocksperrow,
00778                                             JDIMENSION numrows,
00779                                             JDIMENSION maxaccess));
00780   JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
00781   JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
00782                                       jvirt_sarray_ptr ptr,
00783                                       JDIMENSION start_row,
00784                                       JDIMENSION num_rows,
00785                                       boolean writable));
00786   JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
00787                                        jvirt_barray_ptr ptr,
00788                                        JDIMENSION start_row,
00789                                        JDIMENSION num_rows,
00790                                        boolean writable));
00791   JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
00792   JMETHOD(void, self_destruct, (j_common_ptr cinfo));
00793 
00794   /* Limit on memory allocation for this JPEG object.  (Note that this is
00795    * merely advisory, not a guaranteed maximum; it only affects the space
00796    * used for virtual-array buffers.)  May be changed by outer application
00797    * after creating the JPEG object.
00798    */
00799   long max_memory_to_use;
00800 
00801   /* Maximum allocation request accepted by alloc_large. */
00802   long max_alloc_chunk;
00803 };
00804 
00805 
00806 /* Routine signature for application-supplied marker processing methods.
00807  * Need not pass marker code since it is stored in cinfo->unread_marker.
00808  */
00809 typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
00810 
00811 
00812 /* Declarations for routines called by application.
00813  * The JPP macro hides prototype parameters from compilers that can't cope.
00814  * Note JPP requires double parentheses.
00815  */
00816 
00817 #ifdef HAVE_PROTOTYPES
00818 #define JPP(arglist) arglist
00819 #else
00820 #define JPP(arglist) ()
00821 #endif
00822 
00823 
00824 /* Short forms of external names for systems with brain-damaged linkers.
00825  * We shorten external names to be unique in the first six letters, which
00826  * is good enough for all known systems.
00827  * (If your compiler itself needs names to be unique in less than 15 
00828  * characters, you are out of luck.  Get a better compiler.)
00829  */
00830 
00831 #ifdef NEED_SHORT_EXTERNAL_NAMES
00832 #define jpeg_std_error             jStdError
00833 #define jpeg_CreateCompress jCreaCompress
00834 #define jpeg_CreateDecompress      jCreaDecompress
00835 #define jpeg_destroy_compress      jDestCompress
00836 #define jpeg_destroy_decompress    jDestDecompress
00837 #define jpeg_stdio_dest            jStdDest
00838 #define jpeg_stdio_src             jStdSrc
00839 #define jpeg_set_defaults   jSetDefaults
00840 #define jpeg_set_colorspace jSetColorspace
00841 #define jpeg_default_colorspace    jDefColorspace
00842 #define jpeg_set_quality    jSetQuality
00843 #define jpeg_set_linear_quality    jSetLQuality
00844 #define jpeg_add_quant_table       jAddQuantTable
00845 #define jpeg_quality_scaling       jQualityScaling
00846 #define jpeg_simple_progression    jSimProgress
00847 #define jpeg_suppress_tables       jSuppressTables
00848 #define jpeg_alloc_quant_table     jAlcQTable
00849 #define jpeg_alloc_huff_table      jAlcHTable
00850 #define jpeg_start_compress jStrtCompress
00851 #define jpeg_write_scanlines       jWrtScanlines
00852 #define jpeg_finish_compress       jFinCompress
00853 #define jpeg_write_raw_data jWrtRawData
00854 #define jpeg_write_marker   jWrtMarker
00855 #define jpeg_write_m_header jWrtMHeader
00856 #define jpeg_write_m_byte   jWrtMByte
00857 #define jpeg_write_tables   jWrtTables
00858 #define jpeg_read_header    jReadHeader
00859 #define jpeg_start_decompress      jStrtDecompress
00860 #define jpeg_read_scanlines jReadScanlines
00861 #define jpeg_finish_decompress     jFinDecompress
00862 #define jpeg_read_raw_data  jReadRawData
00863 #define jpeg_has_multiple_scans    jHasMultScn
00864 #define jpeg_start_output   jStrtOutput
00865 #define jpeg_finish_output  jFinOutput
00866 #define jpeg_input_complete jInComplete
00867 #define jpeg_new_colormap   jNewCMap
00868 #define jpeg_consume_input  jConsumeInput
00869 #define jpeg_calc_output_dimensions       jCalcDimensions
00870 #define jpeg_save_markers   jSaveMarkers
00871 #define jpeg_set_marker_processor  jSetMarker
00872 #define jpeg_read_coefficients     jReadCoefs
00873 #define jpeg_write_coefficients    jWrtCoefs
00874 #define jpeg_copy_critical_parameters     jCopyCrit
00875 #define jpeg_abort_compress jAbrtCompress
00876 #define jpeg_abort_decompress      jAbrtDecompress
00877 #define jpeg_abort          jAbort
00878 #define jpeg_destroy        jDestroy
00879 #define jpeg_resync_to_restart     jResyncRestart
00880 #endif /* NEED_SHORT_EXTERNAL_NAMES */
00881 
00882 
00883 /* Default error-management setup */
00884 EXTERN(struct jpeg_error_mgr *) jpeg_std_error
00885        JPP((struct jpeg_error_mgr * err));
00886 
00887 /* Initialization of JPEG compression objects.
00888  * jpeg_create_compress() and jpeg_create_decompress() are the exported
00889  * names that applications should call.  These expand to calls on
00890  * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
00891  * passed for version mismatch checking.
00892  * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
00893  */
00894 #define jpeg_create_compress(cinfo) \
00895     jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
00896                      (size_t) sizeof(struct jpeg_compress_struct))
00897 #define jpeg_create_decompress(cinfo) \
00898     jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
00899                        (size_t) sizeof(struct jpeg_decompress_struct))
00900 EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo,
00901                                   int version, size_t structsize));
00902 EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo,
00903                                    int version, size_t structsize));
00904 /* Destruction of JPEG compression objects */
00905 EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo));
00906 EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
00907 
00908 /* Standard data source and destination managers: stdio streams. */
00909 /* Caller is responsible for opening the file before and closing after. */
00910 EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
00911 EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile));
00912 
00913 /* Default parameter setup for compression */
00914 EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo));
00915 /* Compression parameter setup aids */
00916 EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo,
00917                                   J_COLOR_SPACE colorspace));
00918 EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo));
00919 EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
00920                                boolean force_baseline));
00921 EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
00922                                      int scale_factor,
00923                                      boolean force_baseline));
00924 EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
00925                                    const unsigned int *basic_table,
00926                                    int scale_factor,
00927                                    boolean force_baseline));
00928 EXTERN(int) jpeg_quality_scaling JPP((int quality));
00929 EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo));
00930 EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo,
00931                                    boolean suppress));
00932 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo));
00933 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo));
00934 
00935 /* Main entry points for compression */
00936 EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo,
00937                                   boolean write_all_tables));
00938 EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo,
00939                                         JSAMPARRAY scanlines,
00940                                         JDIMENSION num_lines));
00941 EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo));
00942 
00943 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
00944 EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo,
00945                                        JSAMPIMAGE data,
00946                                        JDIMENSION num_lines));
00947 
00948 /* Write a special marker.  See libjpeg.doc concerning safe usage. */
00949 EXTERN(void) jpeg_write_marker
00950        JPP((j_compress_ptr cinfo, int marker,
00951             const JOCTET * dataptr, unsigned int datalen));
00952 /* Same, but piecemeal. */
00953 EXTERN(void) jpeg_write_m_header
00954        JPP((j_compress_ptr cinfo, int marker, unsigned int datalen));
00955 EXTERN(void) jpeg_write_m_byte
00956        JPP((j_compress_ptr cinfo, int val));
00957 
00958 /* Alternate compression function: just write an abbreviated table file */
00959 EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo));
00960 
00961 /* Decompression startup: read start of JPEG datastream to see what's there */
00962 EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo,
00963                               boolean require_image));
00964 /* Return value is one of: */
00965 #define JPEG_SUSPENDED             0 /* Suspended due to lack of input data */
00966 #define JPEG_HEADER_OK             1 /* Found valid image datastream */
00967 #define JPEG_HEADER_TABLES_ONLY    2 /* Found valid table-specs-only datastream */
00968 /* If you pass require_image = TRUE (normal case), you need not check for
00969  * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
00970  * JPEG_SUSPENDED is only possible if you use a data source module that can
00971  * give a suspension return (the stdio source module doesn't).
00972  */
00973 
00974 /* Main entry points for decompression */
00975 EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo));
00976 EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
00977                                        JSAMPARRAY scanlines,
00978                                        JDIMENSION max_lines));
00979 EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
00980 
00981 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
00982 EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
00983                                       JSAMPIMAGE data,
00984                                       JDIMENSION max_lines));
00985 
00986 /* Additional entry points for buffered-image mode. */
00987 EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
00988 EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo,
00989                                    int scan_number));
00990 EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo));
00991 EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo));
00992 EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo));
00993 EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo));
00994 /* Return value is one of: */
00995 /* #define JPEG_SUSPENDED   0    Suspended due to lack of input data */
00996 #define JPEG_REACHED_SOS    1 /* Reached start of new scan */
00997 #define JPEG_REACHED_EOI    2 /* Reached end of image */
00998 #define JPEG_ROW_COMPLETED  3 /* Completed one iMCU row */
00999 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
01000 
01001 /* Precalculate output dimensions for current decompression parameters. */
01002 EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo));
01003 
01004 /* Control saving of COM and APPn markers into marker_list. */
01005 EXTERN(void) jpeg_save_markers
01006        JPP((j_decompress_ptr cinfo, int marker_code,
01007             unsigned int length_limit));
01008 
01009 /* Install a special processing method for COM or APPn markers. */
01010 EXTERN(void) jpeg_set_marker_processor
01011        JPP((j_decompress_ptr cinfo, int marker_code,
01012             jpeg_marker_parser_method routine));
01013 
01014 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
01015 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo));
01016 EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo,
01017                                      jvirt_barray_ptr * coef_arrays));
01018 EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo,
01019                                           j_compress_ptr dstinfo));
01020 
01021 /* If you choose to abort compression or decompression before completing
01022  * jpeg_finish_(de)compress, then you need to clean up to release memory,
01023  * temporary files, etc.  You can just call jpeg_destroy_(de)compress
01024  * if you're done with the JPEG object, but if you want to clean it up and
01025  * reuse it, call this:
01026  */
01027 EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo));
01028 EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo));
01029 
01030 /* Generic versions of jpeg_abort and jpeg_destroy that work on either
01031  * flavor of JPEG object.  These may be more convenient in some places.
01032  */
01033 EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo));
01034 EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo));
01035 
01036 /* Default restart-marker-resync procedure for use by data source modules */
01037 EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo,
01038                                        int desired));
01039 
01040 
01041 /* These marker codes are exported since applications and data source modules
01042  * are likely to want to use them.
01043  */
01044 
01045 #define JPEG_RST0    0xD0   /* RST0 marker code */
01046 #define JPEG_EOI     0xD9   /* EOI marker code */
01047 #define JPEG_APP0    0xE0   /* APP0 marker code */
01048 #define JPEG_COM     0xFE   /* COM marker code */
01049 
01050 
01051 /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
01052  * for structure definitions that are never filled in, keep it quiet by
01053  * supplying dummy definitions for the various substructures.
01054  */
01055 
01056 #ifdef INCOMPLETE_TYPES_BROKEN
01057 #ifndef JPEG_INTERNALS             /* will be defined in jpegint.h */
01058 struct jvirt_sarray_control { long dummy; };
01059 struct jvirt_barray_control { long dummy; };
01060 struct jpeg_comp_master { long dummy; };
01061 struct jpeg_c_main_controller { long dummy; };
01062 struct jpeg_c_prep_controller { long dummy; };
01063 struct jpeg_c_coef_controller { long dummy; };
01064 struct jpeg_marker_writer { long dummy; };
01065 struct jpeg_color_converter { long dummy; };
01066 struct jpeg_downsampler { long dummy; };
01067 struct jpeg_forward_dct { long dummy; };
01068 struct jpeg_entropy_encoder { long dummy; };
01069 struct jpeg_decomp_master { long dummy; };
01070 struct jpeg_d_main_controller { long dummy; };
01071 struct jpeg_d_coef_controller { long dummy; };
01072 struct jpeg_d_post_controller { long dummy; };
01073 struct jpeg_input_controller { long dummy; };
01074 struct jpeg_marker_reader { long dummy; };
01075 struct jpeg_entropy_decoder { long dummy; };
01076 struct jpeg_inverse_dct { long dummy; };
01077 struct jpeg_upsampler { long dummy; };
01078 struct jpeg_color_deconverter { long dummy; };
01079 struct jpeg_color_quantizer { long dummy; };
01080 #endif /* JPEG_INTERNALS */
01081 #endif /* INCOMPLETE_TYPES_BROKEN */
01082 
01083 
01084 /*
01085  * The JPEG library modules define JPEG_INTERNALS before including this file.
01086  * The internal structure declarations are read only when that is true.
01087  * Applications using the library should not include jpegint.h, but may wish
01088  * to include jerror.h.
01089  */
01090 
01091 #ifdef JPEG_INTERNALS
01092 #include "jpegint.h"        /* fetch private declarations */
01093 #include "jerror.h"         /* fetch error codes too */
01094 #endif
01095 
01096 #endif /* JPEGLIB_H */