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Documentation                       Search   jpeglib.h Go to the documentation of this file. /* * jpeglib.h * * Copyright (C) 1991-1998, Thomas G. Lane. * This file is part of the Independent JPEG Group's software. * For conditions of distribution and use, see the accompanying README file. * * This file defines the application interface for the JPEG library. * Most applications using the library need only include this file, * and perhaps jerror.h if they want to know the exact error codes. */ #ifndef JPEGLIB_H #define JPEGLIB_H /* * First we include the configuration files that record how this * installation of the JPEG library is set up. jconfig.h can be * generated automatically for many systems. jmorecfg.h contains * manual configuration options that most people need not worry about. */ #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */ #include "jconfig.h" /* widely used configuration options */ #endif #include "jmorecfg.h" /* seldom changed options */ /* Version ID for the JPEG library. * Might be useful for tests like "#if JPEG_LIB_VERSION >= 60". */ #define JPEG_LIB_VERSION 62 /* Version 6b */ /* Various constants determining the sizes of things. * All of these are specified by the JPEG standard, so don't change them * if you want to be compatible. */ #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */ #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */ #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */ #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */ #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */ #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */ #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */ /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard; * the PostScript DCT filter can emit files with many more than 10 blocks/MCU. * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU * to handle it. We even let you do this from the jconfig.h file. However, * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe * sometimes emits noncompliant files doesn't mean you should too. */ #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */ #ifndef D_MAX_BLOCKS_IN_MCU #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */ #endif /* Data structures for images (arrays of samples and of DCT coefficients). * On 80x86 machines, the image arrays are too big for near pointers, * but the pointer arrays can fit in near memory. */ typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */ typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */ typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */ typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */ typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */ typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */ typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */ typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */ /* Types for JPEG compression parameters and working tables. */ /* DCT coefficient quantization tables. */ typedef struct { /* This array gives the coefficient quantizers in natural array order * (not the zigzag order in which they are stored in a JPEG DQT marker). * CAUTION: IJG versions prior to v6a kept this array in zigzag order. */ UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */ /* This field is used only during compression. It's initialized FALSE when * the table is created, and set TRUE when it's been output to the file. * You could suppress output of a table by setting this to TRUE. * (See jpeg_suppress_tables for an example.) */ boolean sent_table; /* TRUE when table has been output */ } JQUANT_TBL; /* Huffman coding tables. */ typedef struct { /* These two fields directly represent the contents of a JPEG DHT marker */ UINT8 bits[17]; /* bits[k] = # of symbols with codes of */ /* length k bits; bits[0] is unused */ UINT8 huffval[256]; /* The symbols, in order of incr code length */ /* This field is used only during compression. It's initialized FALSE when * the table is created, and set TRUE when it's been output to the file. * You could suppress output of a table by setting this to TRUE. * (See jpeg_suppress_tables for an example.) */ boolean sent_table; /* TRUE when table has been output */ } JHUFF_TBL; /* Basic info about one component (color channel). */ typedef struct { /* These values are fixed over the whole image. */ /* For compression, they must be supplied by parameter setup; */ /* for decompression, they are read from the SOF marker. */ int component_id; /* identifier for this component (0..255) */ int component_index; /* its index in SOF or cinfo->comp_info[] */ int h_samp_factor; /* horizontal sampling factor (1..4) */ int v_samp_factor; /* vertical sampling factor (1..4) */ int quant_tbl_no; /* quantization table selector (0..3) */ /* These values may vary between scans. */ /* For compression, they must be supplied by parameter setup; */ /* for decompression, they are read from the SOS marker. */ /* The decompressor output side may not use these variables. */ int dc_tbl_no; /* DC entropy table selector (0..3) */ int ac_tbl_no; /* AC entropy table selector (0..3) */ /* Remaining fields should be treated as private by applications. */ /* These values are computed during compression or decompression startup: */ /* Component's size in DCT blocks. * Any dummy blocks added to complete an MCU are not counted; therefore * these values do not depend on whether a scan is interleaved or not. */ JDIMENSION width_in_blocks; JDIMENSION height_in_blocks; /* Size of a DCT block in samples. Always DCTSIZE for compression. * For decompression this is the size of the output from one DCT block, * reflecting any scaling we choose to apply during the IDCT step. * Values of 1,2,4,8 are likely to be supported. Note that different * components may receive different IDCT scalings. */ int DCT_scaled_size; /* The downsampled dimensions are the component's actual, unpadded number * of samples at the main buffer (preprocessing/compression interface), thus * downsampled_width = ceil(image_width * Hi/Hmax) * and similarly for height. For decompression, IDCT scaling is included, so * downsampled_width = ceil(image_width * Hi/Hmax * DCT_scaled_size/DCTSIZE) */ JDIMENSION downsampled_width; /* actual width in samples */ JDIMENSION downsampled_height; /* actual height in samples */ /* This flag is used only for decompression. In cases where some of the * components will be ignored (eg grayscale output from YCbCr image), * we can skip most computations for the unused components. */ boolean component_needed; /* do we need the value of this component? */ /* These values are computed before starting a scan of the component. */ /* The decompressor output side may not use these variables. */ int MCU_width; /* number of blocks per MCU, horizontally */ int MCU_height; /* number of blocks per MCU, vertically */ int MCU_blocks; /* MCU_width * MCU_height */ int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_scaled_size */ int last_col_width; /* # of non-dummy blocks across in last MCU */ int last_row_height; /* # of non-dummy blocks down in last MCU */ /* Saved quantization table for component; NULL if none yet saved. * See jdinput.c comments about the need for this information. * This field is currently used only for decompression. */ JQUANT_TBL * quant_table; /* Private per-component storage for DCT or IDCT subsystem. */ void * dct_table; } jpeg_component_info; /* The script for encoding a multiple-scan file is an array of these: */ typedef struct { int comps_in_scan; /* number of components encoded in this scan */ int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */ int Ss, Se; /* progressive JPEG spectral selection parms */ int Ah, Al; /* progressive JPEG successive approx. parms */ } jpeg_scan_info; /* The decompressor can save APPn and COM markers in a list of these: */ typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr; struct jpeg_marker_struct { jpeg_saved_marker_ptr next; /* next in list, or NULL */ UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */ unsigned int original_length; /* # bytes of data in the file */ unsigned int data_length; /* # bytes of data saved at data[] */ JOCTET FAR * data; /* the data contained in the marker */ /* the marker length word is not counted in data_length or original_length */ }; /* Known color spaces. */ typedef enum { JCS_UNKNOWN, /* error/unspecified */ JCS_GRAYSCALE, /* monochrome */ JCS_RGB, /* red/green/blue */ JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */ JCS_CMYK, /* C/M/Y/K */ JCS_YCCK /* Y/Cb/Cr/K */ } J_COLOR_SPACE; /* DCT/IDCT algorithm options. */ typedef enum { JDCT_ISLOW, /* slow but accurate integer algorithm */ JDCT_IFAST, /* faster, less accurate integer method */ JDCT_FLOAT /* floating-point: accurate, fast on fast HW */ } J_DCT_METHOD; #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */ #define JDCT_DEFAULT JDCT_ISLOW #endif #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */ #define JDCT_FASTEST JDCT_IFAST #endif /* Dithering options for decompression. */ typedef enum { JDITHER_NONE, /* no dithering */ JDITHER_ORDERED, /* simple ordered dither */ JDITHER_FS /* Floyd-Steinberg error diffusion dither */ } J_DITHER_MODE; /* Common fields between JPEG compression and decompression master structs. */ #define jpeg_common_fields \ struct jpeg_error_mgr * err; /* Error handler module */\ struct jpeg_memory_mgr * mem; /* Memory manager module */\ struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\ void * client_data; /* Available for use by application */\ boolean is_decompressor; /* So common code can tell which is which */\ int global_state /* For checking call sequence validity */ /* Routines that are to be used by both halves of the library are declared * to receive a pointer to this structure. There are no actual instances of * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct. */ struct jpeg_common_struct { jpeg_common_fields; /* Fields common to both master struct types */ /* Additional fields follow in an actual jpeg_compress_struct or * jpeg_decompress_struct. All three structs must agree on these * initial fields! (This would be a lot cleaner in C++.) */ }; typedef struct jpeg_common_struct * j_common_ptr; typedef struct jpeg_compress_struct * j_compress_ptr; typedef struct jpeg_decompress_struct * j_decompress_ptr; /* Master record for a compression instance */ struct jpeg_compress_struct { jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */ /* Destination for compressed data */ struct jpeg_destination_mgr * dest; /* Description of source image --- these fields must be filled in by * outer application before starting compression. in_color_space must * be correct before you can even call jpeg_set_defaults(). */ JDIMENSION image_width; /* input image width */ JDIMENSION image_height; /* input image height */ int input_components; /* # of color components in input image */ J_COLOR_SPACE in_color_space; /* colorspace of input image */ double input_gamma; /* image gamma of input image */ /* Compression parameters --- these fields must be set before calling * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to * initialize everything to reasonable defaults, then changing anything * the application specifically wants to change. That way you won't get * burnt when new parameters are added. Also note that there are several * helper routines to simplify changing parameters. */ int data_precision; /* bits of precision in image data */ int num_components; /* # of color components in JPEG image */ J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ jpeg_component_info * comp_info; /* comp_info[i] describes component that appears i'th in SOF */ JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; /* ptrs to coefficient quantization tables, or NULL if not defined */ JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; /* ptrs to Huffman coding tables, or NULL if not defined */ UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ int num_scans; /* # of entries in scan_info array */ const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */ /* The default value of scan_info is NULL, which causes a single-scan * sequential JPEG file to be emitted. To create a multi-scan file, * set num_scans and scan_info to point to an array of scan definitions. */ boolean raw_data_in; /* TRUE=caller supplies downsampled data */ boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ boolean optimize_coding; /* TRUE=optimize entropy encoding parms */ boolean CCIR601_sampling; /* TRUE=first samples are cosited */ int smoothing_factor; /* 1..100, or 0 for no input smoothing */ J_DCT_METHOD dct_method; /* DCT algorithm selector */ /* The restart interval can be specified in absolute MCUs by setting * restart_interval, or in MCU rows by setting restart_in_rows * (in which case the correct restart_interval will be figured * for each scan). */ unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */ int restart_in_rows; /* if > 0, MCU rows per restart interval */ /* Parameters controlling emission of special markers. */ boolean write_JFIF_header; /* should a JFIF marker be written? */ UINT8 JFIF_major_version; /* What to write for the JFIF version number */ UINT8 JFIF_minor_version; /* These three values are not used by the JPEG code, merely copied */ /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */ /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */ /* ratio is defined by X_density/Y_density even when density_unit=0. */ UINT8 density_unit; /* JFIF code for pixel size units */ UINT16 X_density; /* Horizontal pixel density */ UINT16 Y_density; /* Vertical pixel density */ boolean write_Adobe_marker; /* should an Adobe marker be written? */ /* State variable: index of next scanline to be written to * jpeg_write_scanlines(). Application may use this to control its * processing loop, e.g., "while (next_scanline < image_height)". */ JDIMENSION next_scanline; /* 0 .. image_height-1 */ /* Remaining fields are known throughout compressor, but generally * should not be touched by a surrounding application. */ /* * These fields are computed during compression startup */ boolean progressive_mode; /* TRUE if scan script uses progressive mode */ int max_h_samp_factor; /* largest h_samp_factor */ int max_v_samp_factor; /* largest v_samp_factor */ JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */ /* The coefficient controller receives data in units of MCU rows as defined * for fully interleaved scans (whether the JPEG file is interleaved or not). * There are v_samp_factor * DCTSIZE sample rows of each component in an * "iMCU" (interleaved MCU) row. */ /* * These fields are valid during any one scan. * They describe the components and MCUs actually appearing in the scan. */ int comps_in_scan; /* # of JPEG components in this scan */ jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; /* *cur_comp_info[i] describes component that appears i'th in SOS */ JDIMENSION MCUs_per_row; /* # of MCUs across the image */ JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ int blocks_in_MCU; /* # of DCT blocks per MCU */ int MCU_membership[C_MAX_BLOCKS_IN_MCU]; /* MCU_membership[i] is index in cur_comp_info of component owning */ /* i'th block in an MCU */ int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ /* * Links to compression subobjects (methods and private variables of modules) */ struct jpeg_comp_master * master; struct jpeg_c_main_controller * main; struct jpeg_c_prep_controller * prep; struct jpeg_c_coef_controller * coef; struct jpeg_marker_writer * marker; struct jpeg_color_converter * cconvert; struct jpeg_downsampler * downsample; struct jpeg_forward_dct * fdct; struct jpeg_entropy_encoder * entropy; jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */ int script_space_size; }; /* Master record for a decompression instance */ struct jpeg_decompress_struct { jpeg_common_fields; /* Fields shared with jpeg_compress_struct */ /* Source of compressed data */ struct jpeg_source_mgr * src; /* Basic description of image --- filled in by jpeg_read_header(). */ /* Application may inspect these values to decide how to process image. */ JDIMENSION image_width; /* nominal image width (from SOF marker) */ JDIMENSION image_height; /* nominal image height */ int num_components; /* # of color components in JPEG image */ J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */ /* Decompression processing parameters --- these fields must be set before * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes * them to default values. */ J_COLOR_SPACE out_color_space; /* colorspace for output */ unsigned int scale_num, scale_denom; /* fraction by which to scale image */ double output_gamma; /* image gamma wanted in output */ boolean buffered_image; /* TRUE=multiple output passes */ boolean raw_data_out; /* TRUE=downsampled data wanted */ J_DCT_METHOD dct_method; /* IDCT algorithm selector */ boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */ boolean do_block_smoothing; /* TRUE=apply interblock smoothing */ boolean quantize_colors; /* TRUE=colormapped output wanted */ /* the following are ignored if not quantize_colors: */ J_DITHER_MODE dither_mode; /* type of color dithering to use */ boolean two_pass_quantize; /* TRUE=use two-pass color quantization */ int desired_number_of_colors; /* max # colors to use in created colormap */ /* these are significant only in buffered-image mode: */ boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */ boolean enable_external_quant;/* enable future use of external colormap */ boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */ /* Description of actual output image that will be returned to application. * These fields are computed by jpeg_start_decompress(). * You can also use jpeg_calc_output_dimensions() to determine these values * in advance of calling jpeg_start_decompress(). */ JDIMENSION output_width; /* scaled image width */ JDIMENSION output_height; /* scaled image height */ int out_color_components; /* # of color components in out_color_space */ int output_components; /* # of color components returned */ /* output_components is 1 (a colormap index) when quantizing colors; * otherwise it equals out_color_components. */ int rec_outbuf_height; /* min recommended height of scanline buffer */ /* If the buffer passed to jpeg_read_scanlines() is less than this many rows * high, space and time will be wasted due to unnecessary data copying. * Usually rec_outbuf_height will be 1 or 2, at most 4. */ /* When quantizing colors, the output colormap is described by these fields. * The application can supply a colormap by setting colormap non-NULL before * calling jpeg_start_decompress; otherwise a colormap is created during * jpeg_start_decompress or jpeg_start_output. * The map has out_color_components rows and actual_number_of_colors columns. */ int actual_number_of_colors; /* number of entries in use */ JSAMPARRAY colormap; /* The color map as a 2-D pixel array */ /* State variables: these variables indicate the progress of decompression. * The application may examine these but must not modify them. */ /* Row index of next scanline to be read from jpeg_read_scanlines(). * Application may use this to control its processing loop, e.g., * "while (output_scanline < output_height)". */ JDIMENSION output_scanline; /* 0 .. output_height-1 */ /* Current input scan number and number of iMCU rows completed in scan. * These indicate the progress of the decompressor input side. */ int input_scan_number; /* Number of SOS markers seen so far */ JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */ /* The "output scan number" is the notional scan being displayed by the * output side. The decompressor will not allow output scan/row number * to get ahead of input scan/row, but it can fall arbitrarily far behind. */ int output_scan_number; /* Nominal scan number being displayed */ JDIMENSION output_iMCU_row; /* Number of iMCU rows read */ /* Current progression status. coef_bits[c][i] indicates the precision * with which component c's DCT coefficient i (in zigzag order) is known. * It is -1 when no data has yet been received, otherwise it is the point * transform (shift) value for the most recent scan of the coefficient * (thus, 0 at completion of the progression). * This pointer is NULL when reading a non-progressive file. */ int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */ /* Internal JPEG parameters --- the application usually need not look at * these fields. Note that the decompressor output side may not use * any parameters that can change between scans. */ /* Quantization and Huffman tables are carried forward across input * datastreams when processing abbreviated JPEG datastreams. */ JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS]; /* ptrs to coefficient quantization tables, or NULL if not defined */ JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS]; JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS]; /* ptrs to Huffman coding tables, or NULL if not defined */ /* These parameters are never carried across datastreams, since they * are given in SOF/SOS markers or defined to be reset by SOI. */ int data_precision; /* bits of precision in image data */ jpeg_component_info * comp_info; /* comp_info[i] describes component that appears i'th in SOF */ boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */ boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */ UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */ UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */ UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */ unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */ /* These fields record data obtained from optional markers recognized by * the JPEG library. */ boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */ /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */ UINT8 JFIF_major_version; /* JFIF version number */ UINT8 JFIF_minor_version; UINT8 density_unit; /* JFIF code for pixel size units */ UINT16 X_density; /* Horizontal pixel density */ UINT16 Y_density; /* Vertical pixel density */ boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */ UINT8 Adobe_transform; /* Color transform code from Adobe marker */ boolean CCIR601_sampling; /* TRUE=first samples are cosited */ /* Aside from the specific data retained from APPn markers known to the * library, the uninterpreted contents of any or all APPn and COM markers * can be saved in a list for examination by the application. */ jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */ /* Remaining fields are known throughout decompressor, but generally * should not be touched by a surrounding application. */ /* * These fields are computed during decompression startup */ int max_h_samp_factor; /* largest h_samp_factor */ int max_v_samp_factor; /* largest v_samp_factor */ int min_DCT_scaled_size; /* smallest DCT_scaled_size of any component */ JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */ /* The coefficient controller's input and output progress is measured in * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows * in fully interleaved JPEG scans, but are used whether the scan is * interleaved or not. We define an iMCU row as v_samp_factor DCT block * rows of each component. Therefore, the IDCT output contains * v_samp_factor*DCT_scaled_size sample rows of a component per iMCU row. */ JSAMPLE * sample_range_limit; /* table for fast range-limiting */ /* * These fields are valid during any one scan. * They describe the components and MCUs actually appearing in the scan. * Note that the decompressor output side must not use these fields. */ int comps_in_scan; /* # of JPEG components in this scan */ jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]; /* *cur_comp_info[i] describes component that appears i'th in SOS */ JDIMENSION MCUs_per_row; /* # of MCUs across the image */ JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */ int blocks_in_MCU; /* # of DCT blocks per MCU */ int MCU_membership[D_MAX_BLOCKS_IN_MCU]; /* MCU_membership[i] is index in cur_comp_info of component owning */ /* i'th block in an MCU */ int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */ /* This field is shared between entropy decoder and marker parser. * It is either zero or the code of a JPEG marker that has been * read from the data source, but has not yet been processed. */ int unread_marker; /* * Links to decompression subobjects (methods, private variables of modules) */ struct jpeg_decomp_master * master; struct jpeg_d_main_controller * main; struct jpeg_d_coef_controller * coef; struct jpeg_d_post_controller * post; struct jpeg_input_controller * inputctl; struct jpeg_marker_reader * marker; struct jpeg_entropy_decoder * entropy; struct jpeg_inverse_dct * idct; struct jpeg_upsampler * upsample; struct jpeg_color_deconverter * cconvert; struct jpeg_color_quantizer * cquantize; }; /* "Object" declarations for JPEG modules that may be supplied or called * directly by the surrounding application. * As with all objects in the JPEG library, these structs only define the * publicly visible methods and state variables of a module. Additional * private fields may exist after the public ones. */ /* Error handler object */ struct jpeg_error_mgr { /* Error exit handler: does not return to caller */ JMETHOD(void, error_exit, (j_common_ptr cinfo)); /* Conditionally emit a trace or warning message */ JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level)); /* Routine that actually outputs a trace or error message */ JMETHOD(void, output_message, (j_common_ptr cinfo)); /* Format a message string for the most recent JPEG error or message */ JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer)); #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */ /* Reset error state variables at start of a new image */ JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo)); /* The message ID code and any parameters are saved here. * A message can have one string parameter or up to 8 int parameters. */ int msg_code; #define JMSG_STR_PARM_MAX 80 union { int i[8]; char s[JMSG_STR_PARM_MAX]; } msg_parm; /* Standard state variables for error facility */ int trace_level; /* max msg_level that will be displayed */ /* For recoverable corrupt-data errors, we emit a warning message, * but keep going unless emit_message chooses to abort. emit_message * should count warnings in num_warnings. The surrounding application * can check for bad data by seeing if num_warnings is nonzero at the * end of processing. */ long num_warnings; /* number of corrupt-data warnings */ /* These fields point to the table(s) of error message strings. * An application can change the table pointer to switch to a different * message list (typically, to change the language in which errors are * reported). Some applications may wish to add additional error codes * that will be handled by the JPEG library error mechanism; the second * table pointer is used for this purpose. * * First table includes all errors generated by JPEG library itself. * Error code 0 is reserved for a "no such error string" message. */ const char * const * jpeg_message_table; /* Library errors */ int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */ /* Second table can be added by application (see cjpeg/djpeg for example). * It contains strings numbered first_addon_message..last_addon_message. */ const char * const * addon_message_table; /* Non-library errors */ int first_addon_message; /* code for first string in addon table */ int last_addon_message; /* code for last string in addon table */ }; /* Progress monitor object */ struct jpeg_progress_mgr { JMETHOD(void, progress_monitor, (j_common_ptr cinfo)); long pass_counter; /* work units completed in this pass */ long pass_limit; /* total number of work units in this pass */ int completed_passes; /* passes completed so far */ int total_passes; /* total number of passes expected */ }; /* Data destination object for compression */ struct jpeg_destination_mgr { JOCTET * next_output_byte; /* => next byte to write in buffer */ size_t free_in_buffer; /* # of byte spaces remaining in buffer */ JMETHOD(void, init_destination, (j_compress_ptr cinfo)); JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo)); JMETHOD(void, term_destination, (j_compress_ptr cinfo)); }; /* Data source object for decompression */ struct jpeg_source_mgr { const JOCTET * next_input_byte; /* => next byte to read from buffer */ size_t bytes_in_buffer; /* # of bytes remaining in buffer */ JMETHOD(void, init_source, (j_decompress_ptr cinfo)); JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo)); JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes)); JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired)); JMETHOD(void, term_source, (j_decompress_ptr cinfo)); }; /* Memory manager object. * Allocates "small" objects (a few K total), "large" objects (tens of K), * and "really big" objects (virtual arrays with backing store if needed). * The memory manager does not allow individual objects to be freed; rather, * each created object is assigned to a pool, and whole pools can be freed * at once. This is faster and more convenient than remembering exactly what * to free, especially where malloc()/free() are not too speedy. * NB: alloc routines never return NULL. They exit to error_exit if not * successful. */ #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */ #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */ #define JPOOL_NUMPOOLS 2 typedef struct jvirt_sarray_control * jvirt_sarray_ptr; typedef struct jvirt_barray_control * jvirt_barray_ptr; struct jpeg_memory_mgr { /* Method pointers */ JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id, size_t sizeofobject)); JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id, size_t sizeofobject)); JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id, JDIMENSION samplesperrow, JDIMENSION numrows)); JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id, JDIMENSION blocksperrow, JDIMENSION numrows)); JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo, int pool_id, boolean pre_zero, JDIMENSION samplesperrow, JDIMENSION numrows, JDIMENSION maxaccess)); JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo, int pool_id, boolean pre_zero, JDIMENSION blocksperrow, JDIMENSION numrows, JDIMENSION maxaccess)); JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo)); JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo, jvirt_sarray_ptr ptr, JDIMENSION start_row, JDIMENSION num_rows, boolean writable)); JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo, jvirt_barray_ptr ptr, JDIMENSION start_row, JDIMENSION num_rows, boolean writable)); JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id)); JMETHOD(void, self_destruct, (j_common_ptr cinfo)); /* Limit on memory allocation for this JPEG object. (Note that this is * merely advisory, not a guaranteed maximum; it only affects the space * used for virtual-array buffers.) May be changed by outer application * after creating the JPEG object. */ long max_memory_to_use; /* Maximum allocation request accepted by alloc_large. */ long max_alloc_chunk; }; /* Routine signature for application-supplied marker processing methods. * Need not pass marker code since it is stored in cinfo->unread_marker. */ typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo)); /* Declarations for routines called by application. * The JPP macro hides prototype parameters from compilers that can't cope. * Note JPP requires double parentheses. */ #ifdef HAVE_PROTOTYPES #define JPP(arglist) arglist #else #define JPP(arglist) () #endif /* Short forms of external names for systems with brain-damaged linkers. * We shorten external names to be unique in the first six letters, which * is good enough for all known systems. * (If your compiler itself needs names to be unique in less than 15 * characters, you are out of luck. Get a better compiler.) */ #ifdef NEED_SHORT_EXTERNAL_NAMES #define jpeg_std_error jStdError #define jpeg_CreateCompress jCreaCompress #define jpeg_CreateDecompress jCreaDecompress #define jpeg_destroy_compress jDestCompress #define jpeg_destroy_decompress jDestDecompress #define jpeg_stdio_dest jStdDest #define jpeg_stdio_src jStdSrc #define jpeg_set_defaults jSetDefaults #define jpeg_set_colorspace jSetColorspace #define jpeg_default_colorspace jDefColorspace #define jpeg_set_quality jSetQuality #define jpeg_set_linear_quality jSetLQuality #define jpeg_add_quant_table jAddQuantTable #define jpeg_quality_scaling jQualityScaling #define jpeg_simple_progression jSimProgress #define jpeg_suppress_tables jSuppressTables #define jpeg_alloc_quant_table jAlcQTable #define jpeg_alloc_huff_table jAlcHTable #define jpeg_start_compress jStrtCompress #define jpeg_write_scanlines jWrtScanlines #define jpeg_finish_compress jFinCompress #define jpeg_write_raw_data jWrtRawData #define jpeg_write_marker jWrtMarker #define jpeg_write_m_header jWrtMHeader #define jpeg_write_m_byte jWrtMByte #define jpeg_write_tables jWrtTables #define jpeg_read_header jReadHeader #define jpeg_start_decompress jStrtDecompress #define jpeg_read_scanlines jReadScanlines #define jpeg_finish_decompress jFinDecompress #define jpeg_read_raw_data jReadRawData #define jpeg_has_multiple_scans jHasMultScn #define jpeg_start_output jStrtOutput #define jpeg_finish_output jFinOutput #define jpeg_input_complete jInComplete #define jpeg_new_colormap jNewCMap #define jpeg_consume_input jConsumeInput #define jpeg_calc_output_dimensions jCalcDimensions #define jpeg_save_markers jSaveMarkers #define jpeg_set_marker_processor jSetMarker #define jpeg_read_coefficients jReadCoefs #define jpeg_write_coefficients jWrtCoefs #define jpeg_copy_critical_parameters jCopyCrit #define jpeg_abort_compress jAbrtCompress #define jpeg_abort_decompress jAbrtDecompress #define jpeg_abort jAbort #define jpeg_destroy jDestroy #define jpeg_resync_to_restart jResyncRestart #endif /* NEED_SHORT_EXTERNAL_NAMES */ /* Default error-management setup */ EXTERN(struct jpeg_error_mgr *) jpeg_std_error JPP((struct jpeg_error_mgr * err)); /* Initialization of JPEG compression objects. * jpeg_create_compress() and jpeg_create_decompress() are the exported * names that applications should call. These expand to calls on * jpeg_CreateCompress and jpeg_CreateDecompress with additional information * passed for version mismatch checking. * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx. */ #define jpeg_create_compress(cinfo) \ jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \ (size_t) sizeof(struct jpeg_compress_struct)) #define jpeg_create_decompress(cinfo) \ jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \ (size_t) sizeof(struct jpeg_decompress_struct)) EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo, int version, size_t structsize)); EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo, int version, size_t structsize)); /* Destruction of JPEG compression objects */ EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo)); EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo)); /* Standard data source and destination managers: stdio streams. */ /* Caller is responsible for opening the file before and closing after. */ EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile)); EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile)); /* Default parameter setup for compression */ EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo)); /* Compression parameter setup aids */ EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo, J_COLOR_SPACE colorspace)); EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo)); EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality, boolean force_baseline)); EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo, int scale_factor, boolean force_baseline)); EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl, const unsigned int *basic_table, int scale_factor, boolean force_baseline)); EXTERN(int) jpeg_quality_scaling JPP((int quality)); EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo)); EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo, boolean suppress)); EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo)); EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo)); /* Main entry points for compression */ EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo, boolean write_all_tables)); EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo, JSAMPARRAY scanlines, JDIMENSION num_lines)); EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo)); /* Replaces jpeg_write_scanlines when writing raw downsampled data. */ EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo, JSAMPIMAGE data, JDIMENSION num_lines)); /* Write a special marker. See libjpeg.doc concerning safe usage. */ EXTERN(void) jpeg_write_marker JPP((j_compress_ptr cinfo, int marker, const JOCTET * dataptr, unsigned int datalen)); /* Same, but piecemeal. */ EXTERN(void) jpeg_write_m_header JPP((j_compress_ptr cinfo, int marker, unsigned int datalen)); EXTERN(void) jpeg_write_m_byte JPP((j_compress_ptr cinfo, int val)); /* Alternate compression function: just write an abbreviated table file */ EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo)); /* Decompression startup: read start of JPEG datastream to see what's there */ EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo, boolean require_image)); /* Return value is one of: */ #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */ #define JPEG_HEADER_OK 1 /* Found valid image datastream */ #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */ /* If you pass require_image = TRUE (normal case), you need not check for * a TABLES_ONLY return code; an abbreviated file will cause an error exit. * JPEG_SUSPENDED is only possible if you use a data source module that can * give a suspension return (the stdio source module doesn't). */ /* Main entry points for decompression */ EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo)); EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo, JSAMPARRAY scanlines, JDIMENSION max_lines)); EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo)); /* Replaces jpeg_read_scanlines when reading raw downsampled data. */ EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo, JSAMPIMAGE data, JDIMENSION max_lines)); /* Additional entry points for buffered-image mode. */ EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo)); EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo, int scan_number)); EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo)); EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo)); EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo)); EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo)); /* Return value is one of: */ /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */ #define JPEG_REACHED_SOS 1 /* Reached start of new scan */ #define JPEG_REACHED_EOI 2 /* Reached end of image */ #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */ #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */ /* Precalculate output dimensions for current decompression parameters. */ EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo)); /* Control saving of COM and APPn markers into marker_list. */ EXTERN(void) jpeg_save_markers JPP((j_decompress_ptr cinfo, int marker_code, unsigned int length_limit)); /* Install a special processing method for COM or APPn markers. */ EXTERN(void) jpeg_set_marker_processor JPP((j_decompress_ptr cinfo, int marker_code, jpeg_marker_parser_method routine)); /* Read or write raw DCT coefficients --- useful for lossless transcoding. */ EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo)); EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays)); EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo)); /* If you choose to abort compression or decompression before completing * jpeg_finish_(de)compress, then you need to clean up to release memory, * temporary files, etc. You can just call jpeg_destroy_(de)compress * if you're done with the JPEG object, but if you want to clean it up and * reuse it, call this: */ EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo)); EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo)); /* Generic versions of jpeg_abort and jpeg_destroy that work on either * flavor of JPEG object. These may be more convenient in some places. */ EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo)); EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo)); /* Default restart-marker-resync procedure for use by data source modules */ EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo, int desired)); /* These marker codes are exported since applications and data source modules * are likely to want to use them. */ #define JPEG_RST0 0xD0 /* RST0 marker code */ #define JPEG_EOI 0xD9 /* EOI marker code */ #define JPEG_APP0 0xE0 /* APP0 marker code */ #define JPEG_COM 0xFE /* COM marker code */ /* If we have a brain-damaged compiler that emits warnings (or worse, errors) * for structure definitions that are never filled in, keep it quiet by * supplying dummy definitions for the various substructures. */ #ifdef INCOMPLETE_TYPES_BROKEN #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */ struct jvirt_sarray_control { long dummy; }; struct jvirt_barray_control { long dummy; }; struct jpeg_comp_master { long dummy; }; struct jpeg_c_main_controller { long dummy; }; struct jpeg_c_prep_controller { long dummy; }; struct jpeg_c_coef_controller { long dummy; }; struct jpeg_marker_writer { long dummy; }; struct jpeg_color_converter { long dummy; }; struct jpeg_downsampler { long dummy; }; struct jpeg_forward_dct { long dummy; }; struct jpeg_entropy_encoder { long dummy; }; struct jpeg_decomp_master { long dummy; }; struct jpeg_d_main_controller { long dummy; }; struct jpeg_d_coef_controller { long dummy; }; struct jpeg_d_post_controller { long dummy; }; struct jpeg_input_controller { long dummy; }; struct jpeg_marker_reader { long dummy; }; struct jpeg_entropy_decoder { long dummy; }; struct jpeg_inverse_dct { long dummy; }; struct jpeg_upsampler { long dummy; }; struct jpeg_color_deconverter { long dummy; }; struct jpeg_color_quantizer { long dummy; }; #endif /* JPEG_INTERNALS */ #endif /* INCOMPLETE_TYPES_BROKEN */ /* * The JPEG library modules define JPEG_INTERNALS before including this file. * The internal structure declarations are read only when that is true. * Applications using the library should not include jpegint.h, but may wish * to include jerror.h. */ #ifdef JPEG_INTERNALS #include "jpegint.h" /* fetch private declarations */ #include "jerror.h" /* fetch error codes too */ #endif #endif /* JPEGLIB_H */