/****************************************************************************/ /* abdapi.h */ /* */ /* Bitmap Decompression API header file */ /* */ /* Copyright(C) Microsoft Corporation 1997-1999 */ /****************************************************************************/ #ifndef _H_ABDAPI #define _H_ABDAPI /****************************************************************************/ /* RLE codes */ /****************************************************************************/ /* */ /* The following codes fill a full single byte address space. The approach */ /* is to use the high order bits to identify the code type and the low */ /* order bits to encode the length of the associated run. There are two */ /* forms of order */ /* - regular orders which have a 5 bit length field (31 bytes of data) */ /* - "lite" orders with a 4 bit length */ /* */ /* A value of 0 in the length field indicates an extended length, where */ /* the following byte contains the length of the data. There is also a */ /* "mega mega" form which has a two byte length field. (See end of */ /* codespace of the codes that define the megamega form). */ /* */ /* A set of codes at the high end of the address space is used to encode */ /* commonly occuring short sequences, in particular */ /* - certain single byte FGBG codings */ /* - single bytes of BLACK and WHITE */ /* */ /* */ /* SUMMARY */ /* ******* */ /* 7 6 5 4 3 2 1 0 76543210 76543210 76543210 */ /* */ /* MEGA_BG_RUN 0 0 0 0 0 0 0 0 */ /* */ /* BG_RUN 0 0 0 */ /* */ /* MEGA_FG_RUN 0 0 1 0 0 0 0 0 */ /* */ /* FG_RUN 0 0 1 */ /* */ /* MEGA_FG_BG_IMAGE 0 1 0 0 0 0 0 0 <-data-> ... */ /* */ /* FG_BG_IMAGE 0 1 0 <-data-> ... */ /* */ /* MEGA_COLOR_RUN 0 1 1 0 0 0 0 0 <-color> */ /* */ /* COLOR_RUN 0 1 1 */ /* */ /* MEGA_COLOR_IMAGE 1 0 0 0 0 0 0 0 <-data-> ... */ /* */ /* COLOR_IMAGE 1 0 0 <-data-> ... */ /* */ /* MEGA_PACKED_CLR_IMG 1 0 1 0 0 0 0 0 <-data-> ... */ /* */ /* PACKED COLOR IMAGE 1 0 1 <-data-> ... */ /* */ /* SET_FG_MEGA_FG_RUN 1 1 0 0 0 0 0 0 <-color> */ /* */ /* SET_FG_FG_RUN 1 1 0 0 <-len-> */ /* */ /* SET_FG_MEGA_FG_BG 1 1 0 1 0 0 0 0 <-color> <-data-> ... */ /* */ /* SET_FG_FG_BG 1 1 0 1 <-len-> <-data-> ... */ /* */ /* MEGA_DITHERED_RUN 1 1 1 0 0 0 0 0 <-data-> <-data-> */ /* */ /* DITHERED_RUN 1 1 1 0 <-len-> <-data-> <-data-> */ /* */ /* MEGA_MEGA_BG_RUN 1 1 1 1 0 0 0 0 */ /* */ /* MEGA_MEGA_FG_RUN 1 1 1 1 0 0 0 1 */ /* */ /* MEGA_MEGA_FGBG 1 1 1 1 0 0 1 0 */ /* */ /* MEGA_MEGA_COLOR_RUN 1 1 1 1 0 0 1 1 */ /* */ /* MEGA_MEGA_CLR_IMG 1 1 1 1 0 1 0 0 */ /* */ /* MEGA_MEGA_PACKED_CLR 1 1 1 1 0 1 0 1 */ /* */ /* MEGA_MEGA_SET_FG_RUN 1 1 1 1 0 1 1 0 */ /* */ /* MEGA_MEGA_SET_FGBG 1 1 1 1 0 1 1 1 */ /* */ /* MEGA_MEGA_DITHER 1 1 1 1 1 0 0 0 */ /* */ /* Special FGBG code 1 1 1 1 1 1 0 0 1 FGBG code 0x03 = 11000000 */ /* (Note that 0x01 will generally handled by the single pel insertion code) */ /* */ /* Special FBBG code 2 1 1 1 1 1 0 1 0 FGBG code 0x05 = 10100000 */ /* */ /* Special FBBG code 3 1 1 1 1 1 0 1 1 FGBG code 0x07 = 11100000 */ /* */ /* Special FBBG code 4 1 1 1 1 1 1 0 0 FGBG code 0x0F = 11110000 */ /* */ /* BLACK 1 1 1 1 1 1 0 1 */ /* */ /* WHITE 1 1 1 1 1 1 1 0 */ /* */ /* START_LOSSY 1 1 1 1 1 1 1 1 */ /* */ /* */ /****************************************************************************/ /* GENERAL NOTES */ /****************************************************************************/ /* */ /* - For MEGA runs the length encoded is the length of the run minus the */ /* maximum length of the non-mega form. */ /* In the mega-mega form we encode the plain 16 bit length, to keep */ /* encoding/deconding simple. */ /* */ /* - The sequence BG_RUN,BG_RUN is not exactly what it appears. We */ /* use the fact that this is not generated in normal encoding to */ /* encode <1 foreground>. The same pel */ /* insertion convention applies to any combination of MEGA_BG run and */ /* BG_RUN */ /* */ /* - A packed image is encoded when we find that all the color fields in a */ /* run have 0 in the high order nibble. We do not currently use this code */ /* for 8 bit compression, but it is supported by the V2 decoder. */ /* */ /* - The set fg color code (Used to exist in V1) has been retired in favor */ /* of separate commands for those codes that may embed a color. Generally*/ /* This saves one byte for every foreground color transition for 8bpp. */ /* */ /* - The color run code is new for V2. It indicates a color run where the */ /* XOR is not performed. This applies to, for example, the line of bits */ /* immediately below a text line. (There is no special case for runs of */ /* the bg color - these are treated as any other color run.) */ /* */ /* - Observation shows a high occurrence of BG runs split by single FGBG */ /* codes. In decreasing probability these are 3,5,7,9,f,11,1f,3f (1 is */ /* handled by the implicit BG run break). Save 1 byte by encoding as */ /* single codes */ /* */ /* - There is a relatively high occurrence of single pel color codes ff and */ /* 00. Save 1 byte by encoding as special characters */ /* */ /* - The length in a FGBG run is slightly strange. Because they generally */ /* occur in multiples of 8 bytes we get a big saving if we encode the */ /* length of a short run as length/8. However, for those special */ /* cases where the length is not a multiple of 8 we encode a long run. */ /* Therefore the long form can only cover the range 1-256 bytes. */ /* beyond that we use the mega-mega form. */ /* */ /****************************************************************************/ /* DETAILS OF COMPRESSION CODES */ /****************************************************************************/ /* */ /* BG_RUN */ /* */ /* Represents a background run (black:0) of the specified length. */ /* */ /****************************************************************************/ /* */ /* FG_BG_IMAGE/SET_FG_FG_BG_IMAGE */ /* */ /* Represents a binary image containing only the current foreground(1) and */ /* background(0) colors. */ /* */ /****************************************************************************/ /* */ /* FG_RUN/SET_FG_FG_RUN */ /* */ /* Represents a continuous foreground run of the specified length. */ /* The foreground color is white by default, and is changed by the */ /* SET_FG_FG_RUN version of this code. */ /* */ /****************************************************************************/ /* */ /* DITHERED_RUN */ /* */ /* Represents a run of alternating colors of the specified length. */ /* */ /****************************************************************************/ /* */ /* COLOR_IMAGE */ /* */ /* Represents a color image of the specified length. No XOR is performed. */ /* This data is uncompressed, so we hope that we won't see */ /* many of these codes! */ /* */ /****************************************************************************/ /* */ /* COLOR_RUN */ /* */ /* Represents a color run of the specified length. No XOR is performed. */ /* Since the color is not XORed, it is unlikely to match the running */ /* foreground color information. Therefore this code always carries a */ /* color byte and there is no SET_FG_COLOR_RUN form of the code. */ /* */ /****************************************************************************/ /* */ /* PACKED_COLOR_IMAGE */ /* */ /* Represents a color image of the specified length, with pairs of colors */ /* packed into a single byte. (This can only be done when the color info */ /* is zero in the high order nibble.) */ /* */ /****************************************************************************/ /* */ /* START_LOSSY */ /* */ /* Informs the decoder that lossy mode has been established and any of the */ /* following color runs will need pixel doubling performing. */ /* RLE decoding will remain in this mode until the end of this block */ /* */ /****************************************************************************/ #define CODE_MASK 0xE0 #define CODE_MASK_LITE 0xF0 #define CODE_BG_RUN 0x00 /* 20 */ #define CODE_FG_RUN 0x20 /* 20 */ #define CODE_FG_BG_IMAGE 0x40 /* 20 */ #define CODE_COLOR_RUN 0x60 /* 20 */ #define CODE_COLOR_IMAGE 0x80 /* 20 */ #ifndef DC_HICOLOR #define CODE_PACKED_COLOR_IMAGE 0xA0 /* 20 */ #endif #define CODE_SET_FG_FG_RUN 0xC0 /* 10 */ #define CODE_SET_FG_FG_BG 0xD0 /* 10 */ #define CODE_DITHERED_RUN 0xE0 /* 10 */ #define CODE_MEGA_MEGA_BG_RUN 0xF0 #define CODE_MEGA_MEGA_FG_RUN 0xF1 #define CODE_MEGA_MEGA_FGBG 0xF2 #define CODE_MEGA_MEGA_COLOR_RUN 0xF3 #define CODE_MEGA_MEGA_CLR_IMG 0xF4 #ifndef DC_HICOLOR #define CODE_MEGA_MEGA_PACKED_CLR 0xF5 #endif #define CODE_MEGA_MEGA_SET_FG_RUN 0xF6 #define CODE_MEGA_MEGA_SET_FGBG 0xF7 #define CODE_MEGA_MEGA_DITHER 0xF8 #define CODE_SPECIAL_FGBG_1 0xF9 #define CODE_SPECIAL_FGBG_2 0xFA #ifndef DC_HICOLOR #define CODE_SPECIAL_FGBG_3 0xFB #define CODE_SPECIAL_FGBG_4 0xFC #endif #define CODE_WHITE 0xFD #define CODE_BLACK 0xFE #define CODE_START_LOSSY 0xFF #define MAX_LENGTH_ORDER 31 #define MAX_LENGTH_LONG_ORDER 287 #define MAX_LENGTH_ORDER_LITE 15 #define MAX_LENGTH_LONG_ORDER_LITE 271 #define MAX_LENGTH_FGBG_ORDER (31*8) #define MAX_LENGTH_FGBG_ORDER_LITE (15*8) #define MAX_LENGTH_LONG_FGBG_ORDER 255 /****************************************************************************/ /* The special FGBG codes that correspond to codes F0-F7 */ /****************************************************************************/ #define SPECIAL_FGBG_CODE_1 0x03 #define SPECIAL_FGBG_CODE_2 0x05 #define SPECIAL_FGBG_CODE_3 0x07 #define SPECIAL_FGBG_CODE_4 0x0F /****************************************************************************/ /* */ /* TYPES */ /* */ /****************************************************************************/ /****************************************************************************/ /* The Compressed Data header structure. */ /****************************************************************************/ typedef struct _CD_HEADER { DCUINT16 cbCompFirstRowSize; DCUINT16 cbCompMainBodySize; DCUINT16 cbScanWidth; DCUINT16 cbUncompressedSize; } CD_HEADER; typedef CD_HEADER *PCD_HEADER; /****************************************************************************/ /* */ /* FUNCTIONS */ /* */ /****************************************************************************/ HRESULT DCAPI BD_DecompressBitmap( PDCUINT8 pCompressedData, PDCUINT8 pDstBitmap, DCUINT srcDataSize, DCUINT dstBufferSize, DCUINT noBCHeader, DCUINT8 bitmapBitsPerPel, DCUINT16 bitmapWidth, DCUINT16 bitmapHeight ); #endif /* H_ABDAPI */