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1895 lines
52 KiB
1895 lines
52 KiB
unit GraphicCompression;
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// This file is part of the image library GraphicEx (www.lischke-online.de/Graphics.html).
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//
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// GraphicCompression contains various encoder/decoder classes used to handle compressed
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// data in the various image classes.
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//
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// Currently supported methods are:
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// - LZW (Lempel-Ziff-Welch)
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// + TIF
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// + GIF
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// - RLE (run length encoding)
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// + TGA,
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// + PCX,
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// + TIFF packed bits
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// + SGI
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// + CUT
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// + RLA
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// + PSP
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// - CCITT
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// + raw G3 (fax T.4)
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// + modified G3 (modified Huffman)
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// - LZ77
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//
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// (c) Copyright 1999, 2000 Dipl. Ing. Mike Lischke (public@lischke-online.de). All rights reserved.
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//
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// This package is freeware for non-commercial use only.
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// Contact author for licenses (shareware@lischke-online.de) and see License.txt which comes with the package.
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interface
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{$I GraphicConfiguration.inc}
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uses
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Windows, Classes, SysUtils,
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ZLibC; // general inflate/deflate and LZ77 compression support
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type
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// abstract decoder class to define the base functionality of an encoder/decoder
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TDecoder = class
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public
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); virtual; abstract;
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procedure DecodeEnd; virtual;
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procedure DecodeInit; virtual;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); virtual; abstract;
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procedure EncodeInit; virtual;
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procedure EncodeEnd; virtual;
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end;
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TTargaRLEDecoder = class(TDecoder)
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private
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FColorDepth: Cardinal;
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public
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constructor Create(ColorDepth: Cardinal);
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); override;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); override;
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end;
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{$ifdef UseLZW}
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// Lempel-Ziff-Welch encoder/decoder class
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// TIFF LZW compression / decompression is a bit different to the common LZW code
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TTIFFLZWDecoder = class(TDecoder)
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private
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FCodeSize: Cardinal;
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FCodeMask: Cardinal;
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FFreeCode: Cardinal;
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FOldCode: Cardinal;
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FPrefix: array[0..4095] of Cardinal; // LZW prefix
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FSuffix, // LZW suffix
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FStack: array [0..4095] of Byte; // stack
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FStackPointer: PByte;
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FTarget: PByte;
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FFirstChar: Byte; // buffer for decoded byte
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FClearCode,
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FEOICode: Word;
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function DecodeLZW(Code: Cardinal): Boolean;
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public
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); override;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); override;
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end;
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{$endif} // UseLZW
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TPackbitsRLEDecoder = class(TDecoder)
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public
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); override;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); override;
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end;
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TPCXRLEDecoder = class(TDecoder)
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public
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); override;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); override;
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end;
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TSGIRLEDecoder = class(TDecoder)
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private
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FSampleSize: Byte; // this value can be 1 (for 8 bits) or 2 (for 16 bits)
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public
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constructor Create(SampleSize: Byte);
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); override;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); override;
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end;
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TCUTRLEDecoder = class(TDecoder)
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public
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); override;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); override;
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end;
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TPSPRLEDecoder = class(TDecoder)
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public
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); override;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); override;
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end;
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{$ifdef UseLZW}
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// Note: We need a different LZW decoder class for GIF because the bit order is reversed compared to that
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// of TIFF and the code size increment is handled slightly different.
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TGIFLZWDecoder = class(TDecoder)
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private
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FCodeSize: Cardinal;
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FCodeMask: Cardinal;
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FFreeCode: Cardinal;
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FOldCode: Cardinal;
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FPrefix: array[0..4095] of Cardinal; // LZW prefix
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FSuffix, // LZW suffix
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FStack: array [0..4095] of Byte; // stack
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FStackPointer: PByte;
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FTarget: PByte;
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FFirstChar: Byte; // buffer for decoded byte
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FClearCode,
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FEOICode: Word;
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FInitialCodeSize: Byte;
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function DecodeLZW(Code: Cardinal): Boolean;
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public
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constructor Create(InitialCodeSize: Byte);
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); override;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); override;
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end;
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{$endif} // UseLZW
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TRLADecoder = class(TDecoder)
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public
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); override;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); override;
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end;
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TStateEntry = record
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NewState: array[Boolean] of Cardinal;
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RunLength: Integer;
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end;
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TStateArray = array of TStateEntry;
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TCCITTDecoder = class(TDecoder)
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private
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FOptions: Integer; // determines some options how to proceed
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// Bit 0: if set then two-dimensional encoding was used, otherwise one-dimensional
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// Bit 1: if set then data is uncompressed
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// Bit 2: if set then fill bits are used before EOL codes so that EOL codes always end at
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// at a byte boundary (implicitly handled by state machine)
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FIsWhite, // alternating flag used while coding
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FSwapBits: Boolean; // True if the order of all bits in a byte must be swapped
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FWhiteStates,
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FBlackStates: TStateArray;
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FWidth: Cardinal; // need to know how line length for modified huffman encoding
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// coding/encoding variables
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FBitsLeft,
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FMask,
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FBits: Byte;
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FPackedSize,
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FRestWidth: Cardinal;
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FSource,
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FTarget: PByte;
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FFreeTargetBits: Byte;
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procedure MakeStates;
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protected
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function FillRun(RunLength: Cardinal): Boolean;
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function FindBlackCode: Integer;
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function FindWhiteCode: Integer;
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public
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constructor Create(Options: Integer; SwapBits: Boolean; Width: Cardinal);
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end;
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TCCITTFax3Decoder = class(TCCITTDecoder)
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public
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); override;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); override;
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end;
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TCCITTMHDecoder = class(TCCITTDecoder) // modified Huffman
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private
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public
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); override;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); override;
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end;
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TLZ77Decoder = class(TDecoder)
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private
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FStream: TZState;
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FZLibResult, // returns the return code of the last ZLib operation
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FFlushMode: Integer; // one of flush constants declard in ZLib.pas
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// this is usually Z_FINISH for PSP and Z_PARTIAL_FLUSH for PNG
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function GetAvailableInput: Integer;
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function GetAvailableOutput: Integer;
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public
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constructor Create(FlushMode: Integer);
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procedure Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer); override;
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procedure DecodeEnd; override;
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procedure DecodeInit; override;
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procedure Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal); override;
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property AvailableInput: Integer read GetAvailableInput;
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property AvailableOutput: Integer read GetAvailableOutput;
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property ZLibResult: Integer read FZLibResult;
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end;
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//----------------------------------------------------------------------------------------------------------------------
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implementation
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uses
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Math,
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GraphicStrings;
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const // LZW encoding and decoding support
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NoLZWCode = 4096;
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//----------------- TDecoder (generic decoder class) -------------------------------------------------------------------
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procedure TDecoder.DecodeEnd;
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begin
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end;
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//----------------------------------------------------------------------------------------------------------------------
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procedure TDecoder.DecodeInit;
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begin
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end;
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//----------------------------------------------------------------------------------------------------------------------
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procedure TDecoder.EncodeEnd;
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begin
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end;
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//----------------------------------------------------------------------------------------------------------------------
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procedure TDecoder.EncodeInit;
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begin
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end;
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//----------------- TTargaRLEDecoder -----------------------------------------------------------------------------------
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constructor TTargaRLEDecoder.Create(ColorDepth: Cardinal);
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begin
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FColorDepth := ColorDepth;
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end;
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//----------------------------------------------------------------------------------------------------------------------
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procedure TTargaRLEDecoder.Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer);
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type
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PCardinalArray = ^TCardinalArray;
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TCardinalArray = array[0..MaxInt div 4 - 1] of Cardinal;
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var
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I: Integer;
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SourcePtr,
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TargetPtr: PByte;
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RunLength: Cardinal;
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SourceCardinal: Cardinal;
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begin
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TargetPtr := Dest;
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SourcePtr := Source;
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// unrolled decoder loop to speed up process
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case FColorDepth of
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8:
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while UnpackedSize > 0 do
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begin
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RunLength := 1 + (SourcePtr^ and $7F);
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if SourcePtr^ > $7F then
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begin
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Inc(SourcePtr);
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FillChar(TargetPtr^, RunLength, SourcePtr^);
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Inc(TargetPtr, RunLength);
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Inc(SourcePtr);
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end
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else
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begin
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Inc(SourcePtr);
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Move(SourcePtr^, TargetPtr^, RunLength);
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Inc(SourcePtr, RunLength);
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Inc(TargetPtr, RunLength);
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end;
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Dec(UnpackedSize, RunLength);
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end;
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15,
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16:
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while UnpackedSize > 0 do
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begin
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RunLength := 1 + (SourcePtr^ and $7F);
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if SourcePtr^ > $7F then
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begin
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Inc(SourcePtr);
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for I := 0 to RunLength - 1 do
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begin
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TargetPtr^ := SourcePtr^;
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Inc(SourcePtr);
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Inc(TargetPtr);
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TargetPtr^ := SourcePtr^;
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Dec(SourcePtr);
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Inc(TargetPtr);
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end;
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Inc(SourcePtr, 2);
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end
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else
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begin
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Inc(SourcePtr);
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Move(SourcePtr^, TargetPtr^, 2 * RunLength);
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Inc(SourcePtr, 2 * RunLength);
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Inc(TargetPtr, 2 * RunLength);
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end;
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Dec(UnpackedSize, RunLength);
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end;
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24:
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while UnpackedSize > 0 do
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begin
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RunLength := 1 + (SourcePtr^ and $7F);
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if SourcePtr^ > $7F then
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begin
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Inc(SourcePtr);
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for I := 0 to RunLength - 1 do
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begin
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TargetPtr^ := SourcePtr^;
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Inc(SourcePtr);
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Inc(TargetPtr);
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TargetPtr^ := SourcePtr^;
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Inc(SourcePtr);
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Inc(TargetPtr);
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TargetPtr^ := SourcePtr^;
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Dec(SourcePtr, 2);
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Inc(TargetPtr);
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end;
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Inc(SourcePtr, 3);
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end
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else
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begin
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Inc(SourcePtr);
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Move(SourcePtr^, TargetPtr^, 3 * RunLength);
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Inc(SourcePtr, 3 * RunLength);
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Inc(TargetPtr, 3 * RunLength);
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end;
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Dec(UnpackedSize, RunLength);
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end;
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32:
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while UnpackedSize > 0 do
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begin
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RunLength := 1 + (SourcePtr^ and $7F);
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if SourcePtr^ > $7F then
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begin
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Inc(SourcePtr);
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SourceCardinal := PCardinalArray(SourcePtr)[0];
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for I := 0 to RunLength - 1 do
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PCardinalArray(TargetPtr)[I] := SourceCardinal;
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Inc(TargetPtr, 4 * RunLength);
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Inc(SourcePtr, 4);
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end
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else
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begin
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Inc(SourcePtr);
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Move(SourcePtr^, TargetPtr^, 4 * RunLength);
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Inc(SourcePtr, 4 * RunLength);
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Inc(TargetPtr, 4 * RunLength);
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end;
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Dec(UnpackedSize, RunLength);
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end;
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end;
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Source := SourcePtr;
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end;
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//----------------------------------------------------------------------------------------------------------------------
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function GetPixel(P: PByte; BPP: Byte): Cardinal;
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// Retrieves a pixel value from a buffer. The actual size and order of the bytes is not important
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// since we are only using the value for comparisons with other pixels.
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begin
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Result := P^;
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Inc(P);
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Dec(BPP);
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while BPP > 0 do
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begin
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Result := Result shl 8;
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Result := Result or P^;
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Inc(P);
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Dec(BPP);
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end;
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end;
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//----------------------------------------------------------------------------------------------------------------------
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function CountDiffPixels(P: PByte; BPP: Byte; Count: Integer): Integer;
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// counts pixels in buffer until two identical adjacent ones found
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var
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N: Integer;
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Pixel,
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NextPixel: Cardinal;
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begin
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N := 0;
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NextPixel := 0; // shut up compiler
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if Count = 1 then Result := Count
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else
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begin
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Pixel := GetPixel(P, BPP);
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while Count > 1 do
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begin
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Inc(P, BPP);
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NextPixel := GetPixel(P, BPP);
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if NextPixel = Pixel then Break;
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Pixel := NextPixel;
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Inc(N);
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Dec(Count);
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end;
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if NextPixel = Pixel then Result := N
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else Result := N + 1;
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end;
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end;
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//----------------------------------------------------------------------------------------------------------------------
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function CountSamePixels(P: PByte; BPP: Byte; Count: Integer): Integer;
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var
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Pixel,
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NextPixel: Cardinal;
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begin
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Result := 1;
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Pixel := GetPixel(P, BPP);
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Dec(Count);
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while Count > 0 do
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begin
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Inc(P, BPP);
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NextPixel := GetPixel(P, BPP);
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if NextPixel <> Pixel then Break;
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Inc(Result);
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Dec(Count);
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end;
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end;
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//----------------------------------------------------------------------------------------------------------------------
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procedure TTargaRLEDecoder.Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal);
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// Encodes "Count" bytes pointed to by Source into the buffer supplied with Target and returns the
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// number of bytes stored in Target. BPP denotes bytes per pixel color depth.
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// Note: The target buffer must provide enough space to hold the compressed data. Using a size of
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// twice the size of the input buffer is sufficent.
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var
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DiffCount, // pixel count until two identical
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SameCount: Integer; // number of identical adjacent pixels
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SourcePtr,
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TargetPtr: PByte;
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BPP: Integer;
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begin
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BytesStored := 0;
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SourcePtr := Source;
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TargetPtr := Dest;
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BytesStored := 0;
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// +1 for 15 bits to get the correct 2 bytes per pixel
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BPP := (FColorDepth + 1) div 8;
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while Count > 0 do
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begin
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DiffCount := CountDiffPixels(SourcePtr, BPP, Count);
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SameCount := CountSamePixels(SourcePtr, BPP, Count);
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if DiffCount > 128 then DiffCount := 128;
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if SameCount > 128 then SameCount := 128;
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if DiffCount > 0 then
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begin
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// create a raw packet
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TargetPtr^ := DiffCount - 1; Inc(TargetPtr);
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Dec(Count, DiffCount);
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Inc(BytesStored, (DiffCount * BPP) + 1);
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while DiffCount > 0 do
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begin
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TargetPtr^ := SourcePtr^; Inc(SourcePtr); Inc(TargetPtr);
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if BPP > 1 then begin TargetPtr^ := SourcePtr^; Inc(SourcePtr); Inc(TargetPtr); end;
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if BPP > 2 then begin TargetPtr^ := SourcePtr^; Inc(SourcePtr); Inc(TargetPtr); end;
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if BPP > 3 then begin TargetPtr^ := SourcePtr^; Inc(SourcePtr); Inc(TargetPtr); end;
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Dec(DiffCount);
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end;
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end;
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if SameCount > 1 then
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begin
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// create a RLE packet
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TargetPtr^ := (SameCount - 1) or $80; Inc(TargetPtr);
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Dec(Count, SameCount);
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Inc(BytesStored, BPP + 1);
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Inc(SourcePtr, (SameCount - 1) * BPP);
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TargetPtr^ := SourcePtr^; Inc(SourcePtr); Inc(TargetPtr);
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if BPP > 1 then begin TargetPtr^ := SourcePtr^; Inc(SourcePtr); Inc(TargetPtr); end;
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if BPP > 2 then begin TargetPtr^ := SourcePtr^; Inc(SourcePtr); Inc(TargetPtr); end;
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if BPP > 3 then begin TargetPtr^ := SourcePtr^; Inc(SourcePtr); Inc(TargetPtr); end;
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end;
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end;
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end;
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|
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//----------------- TTIFFLZWDecoder ------------------------------------------------------------------------------------
|
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|
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{$ifdef UseLZW}
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|
|
function TTIFFLZWDecoder.DecodeLZW(Code: Cardinal): Boolean;
|
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|
|
var
|
|
InCode: Cardinal; // buffer for passed code
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|
|
|
begin
|
|
// handling of clear codes
|
|
if Code = FClearCode then
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begin
|
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// reset of all variables
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FCodeSize := 9;
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FCodeMask := (1 shl FCodeSize) - 1;
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FFreeCode := FClearCode + 2;
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FOldCode := NoLZWCode;
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Result := True;
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Exit;
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end;
|
|
|
|
// check whether it is a valid, already registered code
|
|
if Code > FFreeCode then
|
|
raise Exception.Create('TIF LZW: invalid opcode.');
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|
|
// handling for the first LZW code: print and keep it
|
|
if FOldCode = NoLZWCode then
|
|
begin
|
|
FFirstChar := FSuffix[Code];
|
|
FTarget^ := FFirstChar;
|
|
Inc(FTarget);
|
|
FOldCode := Code;
|
|
Result := True;
|
|
Exit;
|
|
end;
|
|
|
|
// keep the passed LZW code
|
|
InCode := Code;
|
|
|
|
// the first LZW code is always smaller than FFirstCode
|
|
if Code = FFreeCode then
|
|
begin
|
|
FStackPointer^ := FFirstChar;
|
|
Inc(FStackPointer);
|
|
Code := FOldCode;
|
|
end;
|
|
|
|
// loop to put decoded bytes onto the stack
|
|
while Code > FClearCode do
|
|
begin
|
|
FStackPointer^ := FSuffix[Code];
|
|
Inc(FStackPointer);
|
|
Code := FPrefix[Code];
|
|
end;
|
|
|
|
// place new code into code table
|
|
FFirstChar := FSuffix[Code];
|
|
FStackPointer^ := FFirstChar;
|
|
Inc(FStackPointer);
|
|
FPrefix[FFreeCode] := FOldCode;
|
|
FSuffix[FFreeCode] := FFirstChar;
|
|
if FFreeCode < 4096 then Inc(FFreeCode);
|
|
|
|
// increase code size if necessary
|
|
if (FFreeCode = FCodeMask) and
|
|
(FCodeSize < 12) then
|
|
begin
|
|
Inc(FCodeSize);
|
|
FCodeMask := (1 shl FCodeSize) - 1;
|
|
end;
|
|
|
|
// put decoded bytes (from the stack) into the target buffer
|
|
FOldCode := InCode;
|
|
repeat
|
|
Dec(FStackPointer);
|
|
FTarget^ := FStackPointer^;
|
|
Inc(FTarget);
|
|
until Cardinal(FStackPointer) <= Cardinal(@FStack);
|
|
|
|
Result := True;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TTIFFLZWDecoder.Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer);
|
|
|
|
var
|
|
I: Integer;
|
|
Data, // current data
|
|
Bits, // counter for bit management
|
|
Code: Cardinal; // current code value
|
|
SourcePtr: PByte;
|
|
|
|
begin
|
|
FTarget := Dest;
|
|
SourcePtr := Source;
|
|
|
|
// initialize parameter
|
|
FClearCode := 1 shl 8;
|
|
FEOICode := FClearCode + 1;
|
|
FFreeCode := FClearCode + 2;
|
|
FOldCode := NoLZWCode;
|
|
FCodeSize := 9;
|
|
FCodeMask := (1 shl FCodeSize) - 1;
|
|
|
|
// init code table
|
|
for I := 0 to FClearCode - 1 do
|
|
begin
|
|
FPrefix[I] := NoLZWCode;
|
|
FSuffix[I] := I;
|
|
end;
|
|
|
|
// initialize stack
|
|
FStackPointer := @FStack;
|
|
|
|
Data := 0;
|
|
Bits := 0;
|
|
for I := 0 to PackedSize - 1 do
|
|
begin
|
|
// read code from bit stream
|
|
Inc(Data, Cardinal(SourcePtr^) shl (24 - Bits));
|
|
Inc(Bits, 8);
|
|
while Bits >= FCodeSize do
|
|
begin
|
|
// current code
|
|
Code := (Data and ($FFFFFFFF - FCodeMask)) shr (32 - FCodeSize);
|
|
// mask it
|
|
Data := Data shl FCodeSize;
|
|
Dec(Bits, FCodeSize);
|
|
|
|
// EOICode -> decoding finished, check also for badly written codes and
|
|
// terminate the loop as soon as the target is filled up
|
|
if (Code = FEOICode) or
|
|
((PChar(FTarget) - PChar(Dest)) >= UnpackedSize) then Exit;
|
|
|
|
if not DecodeLZW(Code) then Break;
|
|
end;
|
|
Inc(SourcePtr);
|
|
end;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TTIFFLZWDecoder.Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal);
|
|
|
|
begin
|
|
|
|
end;
|
|
|
|
{$endif} // UseLZW
|
|
|
|
//----------------- TPackbitsRLEDecoder --------------------------------------------------------------------------------
|
|
|
|
procedure TPackbitsRLEDecoder.Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer);
|
|
|
|
// decodes a simple run-length encoded strip of size PackedSize
|
|
|
|
var
|
|
SourcePtr,
|
|
TargetPtr: PByte;
|
|
N: SmallInt;
|
|
|
|
begin
|
|
TargetPtr := Dest;
|
|
SourcePtr := Source;
|
|
while PackedSize > 0 do
|
|
begin
|
|
N := ShortInt(SourcePtr^);
|
|
Inc(SourcePtr);
|
|
Dec(PackedSize);
|
|
if N < 0 then // replicate next Byte -N + 1 times
|
|
begin
|
|
if N = -128 then Continue; // nop
|
|
N := -N + 1;
|
|
FillChar(TargetPtr^, N, SourcePtr^);
|
|
Inc(SourcePtr);
|
|
Inc(TargetPtr, N);
|
|
Dec(PackedSize);
|
|
end
|
|
else
|
|
begin // copy next N + 1 bytes literally
|
|
Move(SourcePtr^, TargetPtr^, N + 1);
|
|
Inc(TargetPtr, N + 1);
|
|
Inc(SourcePtr, N + 1);
|
|
Dec(PackedSize, N + 1);
|
|
end;
|
|
end;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TPackbitsRLEDecoder.Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal);
|
|
|
|
begin
|
|
|
|
end;
|
|
|
|
//----------------- TPCXRLEDecoder -------------------------------------------------------------------------------------
|
|
|
|
procedure TPCXRLEDecoder.Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer);
|
|
|
|
var
|
|
Count: Integer;
|
|
SourcePtr,
|
|
TargetPtr: PByte;
|
|
|
|
begin
|
|
SourcePtr := Source;
|
|
TargetPtr := Dest;
|
|
while UnpackedSize > 0 do
|
|
begin
|
|
if (SourcePtr^ and $C0) = $C0 then
|
|
begin
|
|
// RLE-Code
|
|
Count := SourcePtr^ and $3F;
|
|
Inc(SourcePtr);
|
|
if UnpackedSize < Count then Count := UnpackedSize;
|
|
FillChar(TargetPtr^, Count, SourcePtr^);
|
|
Inc(SourcePtr);
|
|
Inc(TargetPtr, Count);
|
|
Dec(UnpackedSize, Count);
|
|
end
|
|
else
|
|
begin
|
|
// not compressed
|
|
TargetPtr^ := SourcePtr^;
|
|
Inc(SourcePtr);
|
|
Inc(TargetPtr);
|
|
Dec(UnpackedSize);
|
|
end;
|
|
end;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TPCXRLEDecoder.Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal);
|
|
|
|
begin
|
|
|
|
end;
|
|
|
|
//----------------- TSGIRLEDecoder -------------------------------------------------------------------------------------
|
|
|
|
constructor TSGIRLEDecoder.Create(SampleSize: Byte);
|
|
|
|
begin
|
|
FSampleSize := SampleSize;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TSGIRLEDecoder.Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer);
|
|
|
|
var
|
|
Source8,
|
|
Target8: PByte;
|
|
Source16,
|
|
Target16: PWord;
|
|
Pixel: Byte;
|
|
Pixel16: Word;
|
|
RunLength: Cardinal;
|
|
|
|
begin
|
|
if FSampleSize = 1 then
|
|
begin
|
|
Source8 := Source;
|
|
Target8 := Dest;
|
|
while True do
|
|
begin
|
|
Pixel := Source8^;
|
|
Inc(Source8);
|
|
RunLength := Pixel and $7F;
|
|
if RunLength = 0 then Break;
|
|
|
|
if (Pixel and $80) <> 0 then
|
|
begin
|
|
Move(Source8^, Target8^, RunLength);
|
|
Inc(Target8, RunLength);
|
|
Inc(Source8, RunLength);
|
|
end
|
|
else
|
|
begin
|
|
Pixel := Source8^;
|
|
Inc(Source8);
|
|
FillChar(Target8^, RunLength, Pixel);
|
|
Inc(Target8, RunLength);
|
|
end;
|
|
end;
|
|
end
|
|
else
|
|
begin
|
|
// 16 bits per sample
|
|
Source16 := Source;
|
|
Target16 := Dest;
|
|
while True do
|
|
begin
|
|
// SGI images are stored in big endian style, swap this one repeater value for it
|
|
Pixel16 := Swap(Source16^);
|
|
Inc(Source16);
|
|
RunLength := Pixel16 and $7F;
|
|
if RunLength = 0 then Break;
|
|
|
|
if (Pixel16 and $80) <> 0 then
|
|
begin
|
|
Move(Source16^, Target16^, 2 * RunLength);
|
|
Inc(Source16^, RunLength);
|
|
Inc(Target16^, RunLength);
|
|
end
|
|
else
|
|
begin
|
|
Pixel16 := Source16^;
|
|
Inc(Source16);
|
|
while RunLength > 0 do
|
|
begin
|
|
Target16^ := Pixel16;
|
|
Inc(Target16);
|
|
Dec(RunLength);
|
|
end;
|
|
end;
|
|
end;
|
|
end;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TSGIRLEDecoder.Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal);
|
|
|
|
begin
|
|
|
|
end;
|
|
|
|
//----------------- TCUTRLE --------------------------------------------------------------------------------------------
|
|
|
|
procedure TCUTRLEDecoder.Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer);
|
|
|
|
var
|
|
TargetPtr: PByte;
|
|
Pixel: Byte;
|
|
RunLength: Cardinal;
|
|
|
|
begin
|
|
TargetPtr := Dest;
|
|
// skip first two bytes per row (I don't know their meaning)
|
|
Inc(PByte(Source), 2);
|
|
while True do
|
|
begin
|
|
Pixel := PByte(Source)^;
|
|
Inc(PByte(Source));
|
|
if Pixel = 0 then Break;
|
|
|
|
RunLength := Pixel and $7F;
|
|
if (Pixel and $80) = 0 then
|
|
begin
|
|
Move(Source^, TargetPtr^, RunLength);
|
|
Inc(TargetPtr, RunLength);
|
|
Inc(PByte(Source), RunLength);
|
|
end
|
|
else
|
|
begin
|
|
Pixel := PByte(Source)^;
|
|
Inc(PByte(Source));
|
|
FillChar(TargetPtr^, RunLength, Pixel);
|
|
Inc(TargetPtr, RunLength);
|
|
end;
|
|
end;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TCUTRLEDecoder.Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal);
|
|
|
|
begin
|
|
|
|
end;
|
|
|
|
//----------------- TPSPRLEDecoder -------------------------------------------------------------------------------------
|
|
|
|
procedure TPSPRLEDecoder.Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer);
|
|
|
|
var
|
|
SourcePtr,
|
|
TargetPtr: PByte;
|
|
RunLength: Cardinal;
|
|
|
|
begin
|
|
SourcePtr := Source;
|
|
TargetPtr := Dest;
|
|
while PackedSize > 0 do
|
|
begin
|
|
RunLength := SourcePtr^;
|
|
Inc(SourcePtr);
|
|
Dec(PackedSize);
|
|
if RunLength < 128 then
|
|
begin
|
|
Move(SourcePtr^, TargetPtr^, RunLength);
|
|
Inc(TargetPtr, RunLength);
|
|
Inc(SourcePtr, RunLength);
|
|
Dec(PackedSize, RunLength);
|
|
end
|
|
else
|
|
begin
|
|
Dec(RunLength, 128);
|
|
FillChar(TargetPtr^, RunLength, SourcePtr^);
|
|
Inc(SourcePtr);
|
|
Inc(TargetPtr, RunLength);
|
|
Dec(PackedSize);
|
|
end;
|
|
end;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TPSPRLEDecoder.Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal);
|
|
|
|
begin
|
|
|
|
end;
|
|
|
|
//----------------- TGIFLZWDecoder -------------------------------------------------------------------------------------
|
|
|
|
{$ifdef UseLZW}
|
|
|
|
constructor TGIFLZWDecoder.Create(InitialCodeSize: Byte);
|
|
|
|
begin
|
|
FInitialCodeSize := InitialCodeSize;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
function TGIFLZWDecoder.DecodeLZW(Code: Cardinal): Boolean;
|
|
|
|
var
|
|
InCode: Cardinal; // buffer for passed code
|
|
|
|
begin
|
|
// handling of clear codes
|
|
if Code = FClearCode then
|
|
begin
|
|
// reset of all variables
|
|
FCodeSize := FInitialCodeSize + 1;
|
|
FCodeMask := (1 shl FCodeSize) - 1;
|
|
FFreeCode := FClearCode + 2;
|
|
FOldCode := NoLZWCode;
|
|
Result := True;
|
|
Exit;
|
|
end;
|
|
|
|
// check whether it is a valid, already registered code
|
|
if Code > FFreeCode then
|
|
raise Exception.Create('GIF LZW: invalid opcode.');
|
|
|
|
// handling for the first LZW code: print and keep it
|
|
if FOldCode = NoLZWCode then
|
|
begin
|
|
FFirstChar := FSuffix[Code];
|
|
FTarget^ := FFirstChar;
|
|
Inc(FTarget);
|
|
FOldCode := Code;
|
|
Result := True;
|
|
Exit;
|
|
end;
|
|
|
|
// keep the passed LZW code
|
|
InCode := Code;
|
|
|
|
// the first LZW code is always smaller than FFirstCode
|
|
if Code = FFreeCode then
|
|
begin
|
|
FStackPointer^ := FFirstChar;
|
|
Inc(FStackPointer);
|
|
Code := FOldCode;
|
|
end;
|
|
|
|
// loop to put decoded bytes onto the stack
|
|
while Code > FClearCode do
|
|
begin
|
|
FStackPointer^ := FSuffix[Code];
|
|
Inc(FStackPointer);
|
|
Code := FPrefix[Code];
|
|
end;
|
|
|
|
// place new code into code table
|
|
FFirstChar := FSuffix[Code];
|
|
FStackPointer^ := FFirstChar;
|
|
Inc(FStackPointer);
|
|
FPrefix[FFreeCode] := FOldCode;
|
|
FSuffix[FFreeCode] := FFirstChar;
|
|
|
|
// increase code size if necessary
|
|
if (FFreeCode = FCodeMask) and
|
|
(FCodeSize < 12) then
|
|
begin
|
|
Inc(FCodeSize);
|
|
FCodeMask := (1 shl FCodeSize) - 1;
|
|
end;
|
|
if FFreeCode < 4095 then Inc(FFreeCode);
|
|
|
|
// put decoded bytes (from the stack) into the target buffer
|
|
FOldCode := InCode;
|
|
repeat
|
|
Dec(FStackPointer);
|
|
FTarget^ := FStackPointer^;
|
|
Inc(FTarget);
|
|
until FStackPointer = @FStack;
|
|
|
|
Result := True;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TGIFLZWDecoder.Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer);
|
|
|
|
var
|
|
I: Integer;
|
|
Data, // current data
|
|
Bits, // counter for bit management
|
|
Code: Cardinal; // current code value
|
|
SourcePtr: PByte;
|
|
|
|
begin
|
|
FTarget := Dest;
|
|
SourcePtr := Source;
|
|
|
|
// initialize parameter
|
|
FCodeSize := FInitialCodeSize + 1;
|
|
FClearCode := 1 shl FInitialCodeSize;
|
|
FEOICode := FClearCode + 1;
|
|
FFreeCode := FClearCode + 2;
|
|
FOldCode := NoLZWCode;
|
|
FCodeMask := (1 shl FCodeSize) - 1;
|
|
|
|
// init code table
|
|
for I := 0 to FClearCode - 1 do
|
|
begin
|
|
FPrefix[I] := NoLZWCode;
|
|
FSuffix[I] := I;
|
|
end;
|
|
|
|
// initialize stack
|
|
FStackPointer := @FStack;
|
|
|
|
Data := 0;
|
|
Bits := 0;
|
|
while PackedSize > 0 do
|
|
begin
|
|
// read code from bit stream
|
|
Inc(Data, SourcePtr^ shl Bits);
|
|
Inc(Bits, 8);
|
|
while Bits >= FCodeSize do
|
|
begin
|
|
// current code
|
|
Code := Data and FCodeMask;
|
|
// prepare next run
|
|
Data := Data shr FCodeSize;
|
|
Dec(Bits, FCodeSize);
|
|
|
|
// EOICode -> decoding finished, check also for badly written codes and
|
|
// terminate the loop as soon as the target is filled up
|
|
if (Code = FEOICode) or
|
|
((PChar(FTarget) - PChar(Dest)) >= UnpackedSize) then Exit;
|
|
|
|
if not DecodeLZW(Code) then Break;
|
|
end;
|
|
Inc(SourcePtr);
|
|
Dec(PackedSize);
|
|
end;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TGIFLZWDecoder.Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal);
|
|
|
|
begin
|
|
|
|
end;
|
|
|
|
{$endif}
|
|
|
|
//----------------- TRLADecoder ----------------------------------------------------------------------------------------
|
|
|
|
procedure TRLADecoder.Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer);
|
|
|
|
// decodes a simple run-length encoded strip of size PackedSize
|
|
// this is very similar to TPackbitsRLEDecoder
|
|
|
|
var
|
|
SourcePtr,
|
|
TargetPtr: PByte;
|
|
N: SmallInt;
|
|
|
|
begin
|
|
TargetPtr := Dest;
|
|
SourcePtr := Source;
|
|
while PackedSize > 0 do
|
|
begin
|
|
N := ShortInt(SourcePtr^);
|
|
Inc(SourcePtr);
|
|
Dec(PackedSize);
|
|
if N >= 0 then // replicate next Byte N + 1 times
|
|
begin
|
|
FillChar(TargetPtr^, N + 1, SourcePtr^);
|
|
Inc(TargetPtr, N + 1);
|
|
Inc(SourcePtr);
|
|
Dec(PackedSize);
|
|
end
|
|
else
|
|
begin // copy next -N bytes literally
|
|
Move(SourcePtr^, TargetPtr^, -N);
|
|
Inc(TargetPtr, -N);
|
|
Inc(SourcePtr, -N);
|
|
Inc(PackedSize, N);
|
|
end;
|
|
end;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TRLADecoder.Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal);
|
|
|
|
begin
|
|
|
|
end;
|
|
|
|
//----------------- TCCITTDecoder --------------------------------------------------------------------------------------
|
|
|
|
constructor TCCITTDecoder.Create(Options: Integer; SwapBits: Boolean; Width: Cardinal);
|
|
|
|
begin
|
|
FOptions := Options;
|
|
FSwapBits := SwapBits;
|
|
FWidth := Width;
|
|
MakeStates;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
const
|
|
// 256 bytes to make bit reversing easy,
|
|
// this is actually not much more than writing bit manipulation code, but much faster
|
|
ReverseTable: array[0..255] of Byte = (
|
|
$00, $80, $40, $C0, $20, $A0, $60, $E0,
|
|
$10, $90, $50, $D0, $30, $B0, $70, $F0,
|
|
$08, $88, $48, $C8, $28, $A8, $68, $E8,
|
|
$18, $98, $58, $D8, $38, $B8, $78, $F8,
|
|
$04, $84, $44, $C4, $24, $A4, $64, $E4,
|
|
$14, $94, $54, $D4, $34, $B4, $74, $F4,
|
|
$0C, $8C, $4C, $CC, $2C, $AC, $6C, $EC,
|
|
$1C, $9C, $5C, $DC, $3C, $BC, $7C, $FC,
|
|
$02, $82, $42, $C2, $22, $A2, $62, $E2,
|
|
$12, $92, $52, $D2, $32, $B2, $72, $F2,
|
|
$0A, $8A, $4A, $CA, $2A, $AA, $6A, $EA,
|
|
$1A, $9A, $5A, $DA, $3A, $BA, $7A, $FA,
|
|
$06, $86, $46, $C6, $26, $A6, $66, $E6,
|
|
$16, $96, $56, $D6, $36, $B6, $76, $F6,
|
|
$0E, $8E, $4E, $CE, $2E, $AE, $6E, $EE,
|
|
$1E, $9E, $5E, $DE, $3E, $BE, $7E, $FE,
|
|
$01, $81, $41, $C1, $21, $A1, $61, $E1,
|
|
$11, $91, $51, $D1, $31, $B1, $71, $F1,
|
|
$09, $89, $49, $C9, $29, $A9, $69, $E9,
|
|
$19, $99, $59, $D9, $39, $B9, $79, $F9,
|
|
$05, $85, $45, $C5, $25, $A5, $65, $E5,
|
|
$15, $95, $55, $D5, $35, $B5, $75, $F5,
|
|
$0D, $8D, $4D, $CD, $2D, $AD, $6D, $ED,
|
|
$1D, $9D, $5D, $DD, $3D, $BD, $7D, $FD,
|
|
$03, $83, $43, $C3, $23, $A3, $63, $E3,
|
|
$13, $93, $53, $D3, $33, $B3, $73, $F3,
|
|
$0B, $8B, $4B, $CB, $2B, $AB, $6B, $EB,
|
|
$1B, $9B, $5B, $DB, $3B, $BB, $7B, $FB,
|
|
$07, $87, $47, $C7, $27, $A7, $67, $E7,
|
|
$17, $97, $57, $D7, $37, $B7, $77, $F7,
|
|
$0F, $8F, $4F, $CF, $2F, $AF, $6F, $EF,
|
|
$1F, $9F, $5F, $DF, $3F, $BF, $7F, $FF
|
|
);
|
|
|
|
G3_EOL = -1;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
function TCCITTDecoder.FillRun(RunLength: Cardinal): Boolean;
|
|
|
|
// fills a number of bits with 1s (for black, white only increments pointers),
|
|
// returns True if the line has been filled entirely, otherwise False
|
|
|
|
var
|
|
Run: Cardinal;
|
|
|
|
begin
|
|
Run := Min(FFreeTargetBits, RunLength);
|
|
// fill remaining bits in the current byte
|
|
if Run in [1..7] then
|
|
begin
|
|
Dec(FFreeTargetBits, Run);
|
|
if not FIsWhite then FTarget^ := FTarget^ or (((1 shl Run) - 1) shl FFreeTargetBits);
|
|
if FFreeTargetBits = 0 then
|
|
begin
|
|
Inc(FTarget);
|
|
FFreeTargetBits := 8;
|
|
end;
|
|
Run := RunLength - Run;
|
|
end
|
|
else Run := RunLength;
|
|
|
|
// fill entire bytes whenever possible
|
|
if Run > 0 then
|
|
begin
|
|
if not FIsWhite then FillChar(FTarget^, Run div 8, $FF);
|
|
Inc(FTarget, Run div 8);
|
|
Run := Run mod 8;
|
|
end;
|
|
|
|
// finally fill remaining bits
|
|
if Run > 0 then
|
|
begin
|
|
FFreeTargetBits := 8 - Run;
|
|
if not FIsWhite then FTarget^ := ((1 shl Run) - 1) shl FFreeTargetBits;
|
|
end;
|
|
|
|
// this will throw an exception if the sum of the run lengths for a row is not
|
|
// exactly the row size (the documentation speaks of an unrecoverable error)
|
|
if Cardinal(RunLength) > FRestWidth then RunLength := FRestWidth;
|
|
Dec(FRestWidth, RunLength);
|
|
Result := FRestWidth = 0;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
function TCCITTDecoder.FindBlackCode: Integer;
|
|
|
|
// Executes the state machine to find the run length for the next bit combination.
|
|
// Returns the run length of the found code.
|
|
|
|
var
|
|
State,
|
|
NewState: Cardinal;
|
|
Bit: Boolean;
|
|
|
|
begin
|
|
State := 0;
|
|
Result := 0;
|
|
repeat
|
|
// advance to next byte in the input buffer if necessary
|
|
if FBitsLeft = 0 then
|
|
begin
|
|
if FPackedSize = 0 then Break;
|
|
FBits := FSource^;
|
|
Inc(FSource);
|
|
Dec(FPackedSize);
|
|
FMask := $80;
|
|
FBitsLeft := 8;
|
|
end;
|
|
Bit := (FBits and FMask) <> 0;
|
|
|
|
// advance the state machine
|
|
NewState := FBlackStates[State].NewState[Bit];
|
|
if NewState = 0 then
|
|
begin
|
|
Inc(Result, FBlackStates[State].RunLength);
|
|
if FBlackStates[State].RunLength < 64 then Break
|
|
else
|
|
begin
|
|
NewState := FBlackStates[0].NewState[Bit];
|
|
end;
|
|
end;
|
|
State := NewState;
|
|
|
|
// address next bit
|
|
FMask := FMask shr 1;
|
|
if FBitsLeft > 0 then Dec(FBitsLeft);
|
|
until False;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
function TCCITTDecoder.FindWhiteCode: Integer;
|
|
|
|
// Executes the state machine to find the run length for the next bit combination.
|
|
// Returns the run length of the found code.
|
|
|
|
var
|
|
State,
|
|
NewState: Cardinal;
|
|
Bit: Boolean;
|
|
|
|
begin
|
|
State := 0;
|
|
Result := 0;
|
|
repeat
|
|
// advance to next byte in the input buffer if necessary
|
|
if FBitsLeft = 0 then
|
|
begin
|
|
if FPackedSize = 0 then Break;
|
|
FBits := FSource^;
|
|
Inc(FSource);
|
|
Dec(FPackedSize);
|
|
FMask := $80;
|
|
FBitsLeft := 8;
|
|
end;
|
|
Bit := (FBits and FMask) <> 0;
|
|
|
|
// advance the state machine
|
|
NewState := FWhiteStates[State].NewState[Bit];
|
|
if NewState = 0 then
|
|
begin
|
|
// a code has been found
|
|
Inc(Result, FWhiteStates[State].RunLength);
|
|
// if we found a terminating code then exit loop, otherwise continue
|
|
if FWhiteStates[State].RunLength < 64 then Break
|
|
else
|
|
begin
|
|
// found a make up code, continue state machine with current bit (rather than reading the next one)
|
|
NewState := FWhiteStates[0].NewState[Bit];
|
|
end;
|
|
end;
|
|
State := NewState;
|
|
|
|
// address next bit
|
|
FMask := FMask shr 1;
|
|
if FBitsLeft > 0 then Dec(FBitsLeft);
|
|
until False;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
type
|
|
TCodeEntry = record
|
|
Code, Len: Cardinal;
|
|
end;
|
|
|
|
const // CCITT code tables
|
|
WhiteCodes: array[0..116] of TCodeEntry = (
|
|
(Code : $0035; Len : 8),
|
|
(Code : $0007; Len : 6),
|
|
(Code : $0007; Len : 4),
|
|
(Code : $0008; Len : 4),
|
|
(Code : $000B; Len : 4),
|
|
(Code : $000C; Len : 4),
|
|
(Code : $000E; Len : 4),
|
|
(Code : $000F; Len : 4),
|
|
(Code : $0013; Len : 5),
|
|
(Code : $0014; Len : 5),
|
|
(Code : $0007; Len : 5),
|
|
(Code : $0008; Len : 5),
|
|
(Code : $0008; Len : 6),
|
|
(Code : $0003; Len : 6),
|
|
(Code : $0034; Len : 6),
|
|
(Code : $0035; Len : 6),
|
|
(Code : $002A; Len : 6),
|
|
(Code : $002B; Len : 6),
|
|
(Code : $0027; Len : 7),
|
|
(Code : $000C; Len : 7),
|
|
(Code : $0008; Len : 7),
|
|
(Code : $0017; Len : 7),
|
|
(Code : $0003; Len : 7),
|
|
(Code : $0004; Len : 7),
|
|
(Code : $0028; Len : 7),
|
|
(Code : $002B; Len : 7),
|
|
(Code : $0013; Len : 7),
|
|
(Code : $0024; Len : 7),
|
|
(Code : $0018; Len : 7),
|
|
(Code : $0002; Len : 8),
|
|
(Code : $0003; Len : 8),
|
|
(Code : $001A; Len : 8),
|
|
(Code : $001B; Len : 8),
|
|
(Code : $0012; Len : 8),
|
|
(Code : $0013; Len : 8),
|
|
(Code : $0014; Len : 8),
|
|
(Code : $0015; Len : 8),
|
|
(Code : $0016; Len : 8),
|
|
(Code : $0017; Len : 8),
|
|
(Code : $0028; Len : 8),
|
|
(Code : $0029; Len : 8),
|
|
(Code : $002A; Len : 8),
|
|
(Code : $002B; Len : 8),
|
|
(Code : $002C; Len : 8),
|
|
(Code : $002D; Len : 8),
|
|
(Code : $0004; Len : 8),
|
|
(Code : $0005; Len : 8),
|
|
(Code : $000A; Len : 8),
|
|
(Code : $000B; Len : 8),
|
|
(Code : $0052; Len : 8),
|
|
(Code : $0053; Len : 8),
|
|
(Code : $0054; Len : 8),
|
|
(Code : $0055; Len : 8),
|
|
(Code : $0024; Len : 8),
|
|
(Code : $0025; Len : 8),
|
|
(Code : $0058; Len : 8),
|
|
(Code : $0059; Len : 8),
|
|
(Code : $005A; Len : 8),
|
|
(Code : $005B; Len : 8),
|
|
(Code : $004A; Len : 8),
|
|
(Code : $004B; Len : 8),
|
|
(Code : $0032; Len : 8),
|
|
(Code : $0033; Len : 8),
|
|
(Code : $0034; Len : 8),
|
|
(Code : $001B; Len : 5),
|
|
(Code : $0012; Len : 5),
|
|
(Code : $0017; Len : 6),
|
|
(Code : $0037; Len : 7),
|
|
(Code : $0036; Len : 8),
|
|
(Code : $0037; Len : 8),
|
|
(Code : $0064; Len : 8),
|
|
(Code : $0065; Len : 8),
|
|
(Code : $0068; Len : 8),
|
|
(Code : $0067; Len : 8),
|
|
(Code : $00CC; Len : 9),
|
|
(Code : $00CD; Len : 9),
|
|
(Code : $00D2; Len : 9),
|
|
(Code : $00D3; Len : 9),
|
|
(Code : $00D4; Len : 9),
|
|
(Code : $00D5; Len : 9),
|
|
(Code : $00D6; Len : 9),
|
|
(Code : $00D7; Len : 9),
|
|
(Code : $00D8; Len : 9),
|
|
(Code : $00D9; Len : 9),
|
|
(Code : $00DA; Len : 9),
|
|
(Code : $00DB; Len : 9),
|
|
(Code : $0098; Len : 9),
|
|
(Code : $0099; Len : 9),
|
|
(Code : $009A; Len : 9),
|
|
(Code : $0018; Len : 6),
|
|
(Code : $009B; Len : 9),
|
|
(Code : $0008; Len : 11),
|
|
(Code : $000C; Len : 11),
|
|
(Code : $000D; Len : 11),
|
|
(Code : $0012; Len : 12),
|
|
(Code : $0013; Len : 12),
|
|
(Code : $0014; Len : 12),
|
|
(Code : $0015; Len : 12),
|
|
(Code : $0016; Len : 12),
|
|
(Code : $0017; Len : 12),
|
|
(Code : $001C; Len : 12),
|
|
(Code : $001D; Len : 12),
|
|
(Code : $001E; Len : 12),
|
|
(Code : $001F; Len : 12),
|
|
// EOL codes
|
|
(Code : $0001; Len : 12),
|
|
(Code : $0001; Len : 13),
|
|
(Code : $0001; Len : 14),
|
|
(Code : $0001; Len : 15),
|
|
(Code : $0001; Len : 16),
|
|
(Code : $0001; Len : 17),
|
|
(Code : $0001; Len : 18),
|
|
(Code : $0001; Len : 19),
|
|
(Code : $0001; Len : 20),
|
|
(Code : $0001; Len : 21),
|
|
(Code : $0001; Len : 22),
|
|
(Code : $0001; Len : 23),
|
|
(Code : $0001; Len : 24)
|
|
);
|
|
|
|
BlackCodes: array[0..116] of TCodeEntry = (
|
|
(Code : $0037; Len : 10),
|
|
(Code : $0002; Len : 3),
|
|
(Code : $0003; Len : 2),
|
|
(Code : $0002; Len : 2),
|
|
(Code : $0003; Len : 3),
|
|
(Code : $0003; Len : 4),
|
|
(Code : $0002; Len : 4),
|
|
(Code : $0003; Len : 5),
|
|
(Code : $0005; Len : 6),
|
|
(Code : $0004; Len : 6),
|
|
(Code : $0004; Len : 7),
|
|
(Code : $0005; Len : 7),
|
|
(Code : $0007; Len : 7),
|
|
(Code : $0004; Len : 8),
|
|
(Code : $0007; Len : 8),
|
|
(Code : $0018; Len : 9),
|
|
(Code : $0017; Len : 10),
|
|
(Code : $0018; Len : 10),
|
|
(Code : $0008; Len : 10),
|
|
(Code : $0067; Len : 11),
|
|
(Code : $0068; Len : 11),
|
|
(Code : $006C; Len : 11),
|
|
(Code : $0037; Len : 11),
|
|
(Code : $0028; Len : 11),
|
|
(Code : $0017; Len : 11),
|
|
(Code : $0018; Len : 11),
|
|
(Code : $00CA; Len : 12),
|
|
(Code : $00CB; Len : 12),
|
|
(Code : $00CC; Len : 12),
|
|
(Code : $00CD; Len : 12),
|
|
(Code : $0068; Len : 12),
|
|
(Code : $0069; Len : 12),
|
|
(Code : $006A; Len : 12),
|
|
(Code : $006B; Len : 12),
|
|
(Code : $00D2; Len : 12),
|
|
(Code : $00D3; Len : 12),
|
|
(Code : $00D4; Len : 12),
|
|
(Code : $00D5; Len : 12),
|
|
(Code : $00D6; Len : 12),
|
|
(Code : $00D7; Len : 12),
|
|
(Code : $006C; Len : 12),
|
|
(Code : $006D; Len : 12),
|
|
(Code : $00DA; Len : 12),
|
|
(Code : $00DB; Len : 12),
|
|
(Code : $0054; Len : 12),
|
|
(Code : $0055; Len : 12),
|
|
(Code : $0056; Len : 12),
|
|
(Code : $0057; Len : 12),
|
|
(Code : $0064; Len : 12),
|
|
(Code : $0065; Len : 12),
|
|
(Code : $0052; Len : 12),
|
|
(Code : $0053; Len : 12),
|
|
(Code : $0024; Len : 12),
|
|
(Code : $0037; Len : 12),
|
|
(Code : $0038; Len : 12),
|
|
(Code : $0027; Len : 12),
|
|
(Code : $0028; Len : 12),
|
|
(Code : $0058; Len : 12),
|
|
(Code : $0059; Len : 12),
|
|
(Code : $002B; Len : 12),
|
|
(Code : $002C; Len : 12),
|
|
(Code : $005A; Len : 12),
|
|
(Code : $0066; Len : 12),
|
|
(Code : $0067; Len : 12),
|
|
(Code : $000F; Len : 10),
|
|
(Code : $00C8; Len : 12),
|
|
(Code : $00C9; Len : 12),
|
|
(Code : $005B; Len : 12),
|
|
(Code : $0033; Len : 12),
|
|
(Code : $0034; Len : 12),
|
|
(Code : $0035; Len : 12),
|
|
(Code : $006C; Len : 13),
|
|
(Code : $006D; Len : 13),
|
|
(Code : $004A; Len : 13),
|
|
(Code : $004B; Len : 13),
|
|
(Code : $004C; Len : 13),
|
|
(Code : $004D; Len : 13),
|
|
(Code : $0072; Len : 13),
|
|
(Code : $0073; Len : 13),
|
|
(Code : $0074; Len : 13),
|
|
(Code : $0075; Len : 13),
|
|
(Code : $0076; Len : 13),
|
|
(Code : $0077; Len : 13),
|
|
(Code : $0052; Len : 13),
|
|
(Code : $0053; Len : 13),
|
|
(Code : $0054; Len : 13),
|
|
(Code : $0055; Len : 13),
|
|
(Code : $005A; Len : 13),
|
|
(Code : $005B; Len : 13),
|
|
(Code : $0064; Len : 13),
|
|
(Code : $0065; Len : 13),
|
|
(Code : $0008; Len : 11),
|
|
(Code : $000C; Len : 11),
|
|
(Code : $000D; Len : 11),
|
|
(Code : $0012; Len : 12),
|
|
(Code : $0013; Len : 12),
|
|
(Code : $0014; Len : 12),
|
|
(Code : $0015; Len : 12),
|
|
(Code : $0016; Len : 12),
|
|
(Code : $0017; Len : 12),
|
|
(Code : $001C; Len : 12),
|
|
(Code : $001D; Len : 12),
|
|
(Code : $001E; Len : 12),
|
|
(Code : $001F; Len : 12),
|
|
// EOL codes
|
|
(Code : $0001; Len : 12),
|
|
(Code : $0001; Len : 13),
|
|
(Code : $0001; Len : 14),
|
|
(Code : $0001; Len : 15),
|
|
(Code : $0001; Len : 16),
|
|
(Code : $0001; Len : 17),
|
|
(Code : $0001; Len : 18),
|
|
(Code : $0001; Len : 19),
|
|
(Code : $0001; Len : 20),
|
|
(Code : $0001; Len : 21),
|
|
(Code : $0001; Len : 22),
|
|
(Code : $0001; Len : 23),
|
|
(Code : $0001; Len : 24)
|
|
);
|
|
|
|
procedure TCCITTDecoder.MakeStates;
|
|
|
|
// creates state arrays for white and black codes
|
|
// These state arrays are so designed that they have at each state (starting with state 0) a new state index
|
|
// into the same array according to the bit for which the state is current.
|
|
|
|
//--------------- local functions -------------------------------------------
|
|
|
|
procedure AddCode(var Target: TStateArray; Bits: Cardinal; BitLen, RL: Integer);
|
|
|
|
// interprets the given string as a sequence of bits and makes a state chain from it
|
|
|
|
var
|
|
State,
|
|
NewState: Integer;
|
|
Bit: Boolean;
|
|
|
|
begin
|
|
// start state
|
|
State := 0;
|
|
// prepare bit combination (bits are given right align, but must be scanned from left)
|
|
Bits := Bits shl (32 - BitLen);
|
|
while BitLen > 0 do
|
|
begin
|
|
// determine next state according to the bit string
|
|
asm
|
|
SHL [Bits], 1
|
|
SETC [Bit]
|
|
end;
|
|
NewState := Target[State].NewState[Bit];
|
|
// Is it a not yet assigned state?
|
|
if NewState = 0 then
|
|
begin
|
|
// if yes then create a new state at the end of the array
|
|
NewState := Length(Target);
|
|
Target[State].NewState[Bit] := NewState;
|
|
SetLength(Target, Length(Target) + 1);
|
|
end;
|
|
State := NewState;
|
|
|
|
Dec(BitLen);
|
|
end;
|
|
// at this point State indicates the final state where we must store the run length for the
|
|
// particular bit combination
|
|
Target[State].RunLength := RL;
|
|
end;
|
|
|
|
//--------------- end local functions ---------------------------------------
|
|
|
|
var
|
|
I: Integer;
|
|
|
|
begin
|
|
// set an initial entry in each state array
|
|
SetLength(FWhiteStates, 1);
|
|
SetLength(FBlackStates, 1);
|
|
|
|
// with codes
|
|
for I := 0 to 63 do
|
|
with WhiteCodes[I] do AddCode(FWhiteStates, Code, Len, I);
|
|
for I := 64 to 102 do
|
|
with WhiteCodes[I] do AddCode(FWhiteStates, Code, Len, (I - 63) * 64);
|
|
for I := 103 to 116 do
|
|
with WhiteCodes[I] do AddCode(FWhiteStates, Code, Len, G3_EOL);
|
|
|
|
// black codes
|
|
for I := 0 to 63 do
|
|
with BlackCodes[I] do AddCode(FBlackStates, Code, Len, I);
|
|
for I := 64 to 102 do
|
|
with BlackCodes[I] do AddCode(FBlackStates, Code, Len, (I - 63) * 64);
|
|
for I := 103 to 116 do
|
|
with BlackCodes[I] do AddCode(FBlackStates, Code, Len, G3_EOL);
|
|
end;
|
|
|
|
//----------------- TCCITTFax3Decoder ----------------------------------------------------------------------------------
|
|
|
|
procedure TCCITTFax3Decoder.Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer);
|
|
|
|
var
|
|
RunLength: Integer;
|
|
|
|
//--------------- local functions -------------------------------------------
|
|
|
|
procedure AdjustEOL;
|
|
|
|
begin
|
|
FIsWhite := False;
|
|
if FFreeTargetBits in [1..7] then Inc(FTarget);
|
|
FFreeTargetBits := 8;
|
|
FRestWidth := FWidth;
|
|
end;
|
|
|
|
//--------------- end local functions ---------------------------------------
|
|
|
|
begin
|
|
// make all bits white
|
|
FillChar(Dest^, UnpackedSize, 0);
|
|
|
|
// swap all bits here, in order to avoid frequent tests in the main loop
|
|
if FSwapBits then
|
|
asm
|
|
PUSH EBX
|
|
LEA EBX, ReverseTable
|
|
MOV ECX, [PackedSize]
|
|
MOV EDX, [Source]
|
|
MOV EDX, [EDX]
|
|
@@1:
|
|
MOV AL, [EDX]
|
|
XLAT
|
|
MOV [EDX], AL
|
|
INC EDX
|
|
DEC ECX
|
|
JNZ @@1
|
|
POP EBX
|
|
end;
|
|
|
|
// setup initial states
|
|
// a row always starts with a (possibly zero-length) white run
|
|
FIsWhite := True;
|
|
FSource := Source;
|
|
FBitsLeft := 0;
|
|
FPackedSize := PackedSize;
|
|
|
|
// target preparation
|
|
FTarget := Dest;
|
|
FRestWidth := FWidth;
|
|
FFreeTargetBits := 8;
|
|
|
|
// main loop
|
|
repeat
|
|
if FIsWhite then RunLength := FindWhiteCode
|
|
else RunLength := FindBlackCode;
|
|
if RunLength > 0 then
|
|
begin
|
|
if FillRun(RunLength) then AdjustEOL;
|
|
end
|
|
else
|
|
if RunLength = G3_EOL then AdjustEOL;
|
|
|
|
FIsWhite := not FIsWhite;
|
|
until FPackedSize = 0;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TCCITTFax3Decoder.Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal);
|
|
|
|
begin
|
|
|
|
end;
|
|
|
|
//----------------- TCCITTMHDecoder ------------------------------------------------------------------------------------
|
|
|
|
procedure TCCITTMHDecoder.Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer);
|
|
|
|
var
|
|
RunLength: Integer;
|
|
|
|
//--------------- local functions -------------------------------------------
|
|
|
|
procedure AdjustEOL;
|
|
|
|
begin
|
|
FIsWhite := False;
|
|
if FFreeTargetBits in [1..7] then Inc(FTarget);
|
|
FFreeTargetBits := 8;
|
|
FRestWidth := FWidth;
|
|
if FBitsLeft < 8 then FBitsLeft := 0; // discard remaining bits
|
|
end;
|
|
|
|
//--------------- end local functions ---------------------------------------
|
|
|
|
begin
|
|
// make all bits white
|
|
FillChar(Dest^, UnpackedSize, 0);
|
|
|
|
// swap all bits here, in order to avoid frequent tests in the main loop
|
|
if FSwapBits then
|
|
asm
|
|
PUSH EBX
|
|
LEA EBX, ReverseTable
|
|
MOV ECX, [PackedSize]
|
|
MOV EDX, [Source]
|
|
MOV EDX, [EDX]
|
|
@@1:
|
|
MOV AL, [EDX]
|
|
XLAT
|
|
MOV [EDX], AL
|
|
INC EDX
|
|
DEC ECX
|
|
JNZ @@1
|
|
POP EBX
|
|
end;
|
|
|
|
// setup initial states
|
|
// a row always starts with a (possibly zero-length) white run
|
|
FIsWhite := True;
|
|
FSource := Source;
|
|
FBitsLeft := 0;
|
|
FPackedSize := PackedSize;
|
|
|
|
// target preparation
|
|
FTarget := Dest;
|
|
FRestWidth := FWidth;
|
|
FFreeTargetBits := 8;
|
|
|
|
// main loop
|
|
repeat
|
|
if FIsWhite then RunLength := FindWhiteCode
|
|
else RunLength := FindBlackCode;
|
|
if RunLength > 0 then
|
|
if FillRun(RunLength) then AdjustEOL;
|
|
FIsWhite := not FIsWhite;
|
|
until FPackedSize = 0;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TCCITTMHDecoder.Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal);
|
|
|
|
begin
|
|
|
|
end;
|
|
|
|
//----------------- TLZ77Decoder ---------------------------------------------------------------------------------------
|
|
|
|
constructor TLZ77Decoder.Create(FlushMode: Integer);
|
|
|
|
begin
|
|
FillChar(FStream, SizeOf(FStream), 0);
|
|
FFlushMode := FlushMode;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TLZ77Decoder.Decode(var Source, Dest: Pointer; PackedSize, UnpackedSize: Integer);
|
|
|
|
begin
|
|
FStream.NextInput := Source;
|
|
FStream.AvailableInput := PackedSize;
|
|
FStream.NextOutput := Dest;
|
|
FStream.AvailableOutput := UnpackedSize;
|
|
FZLibResult := Inflate(FStream, FFlushMode);
|
|
// advance pointers so used input can be calculated
|
|
Source := FStream.NextInput;
|
|
Dest := FStream.NextOutput;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TLZ77Decoder.DecodeEnd;
|
|
|
|
begin
|
|
if InflateEnd(FStream) < 0 then raise Exception.Create('LZ77 decompression error.');
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TLZ77Decoder.DecodeInit;
|
|
|
|
begin
|
|
if InflateInit(FStream) < 0 then raise Exception.Create('LZ77 decompression error.');
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
procedure TLZ77Decoder.Encode(Source, Dest: Pointer; Count: Cardinal; var BytesStored: Cardinal);
|
|
|
|
begin
|
|
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
function TLZ77Decoder.GetAvailableInput: Integer;
|
|
|
|
begin
|
|
Result := FStream.AvailableInput;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
function TLZ77Decoder.GetAvailableOutput: Integer;
|
|
|
|
begin
|
|
Result := FStream.AvailableOutput;
|
|
end;
|
|
|
|
//----------------------------------------------------------------------------------------------------------------------
|
|
|
|
end.
|
|
|