AOO410/main/filter/source/graphicfilter/itiff/lzwdecom.hxx

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 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
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#ifndef _LZWDECOM_HXX
#define _LZWDECOM_HXX

#include <tools/stream.hxx>

struct LZWTableEntry {
	sal_uInt16 nPrevCode;
	sal_uInt16 nDataCount;
	sal_uInt8 nData;
};

class LZWDecompressor {

public:

	LZWDecompressor();
	~LZWDecompressor();

	void StartDecompression(SvStream & rIStream);

	sal_uLong Decompress(sal_uInt8 * pTarget, sal_uLong nMaxCount);
		// Liefert die Anzahl der geschriebenen Bytes, wenn < nMaxCount,
		// sind keine weiteren Daten zu entpacken, oder es ist ein
		// Fehler aufgetreten.

private:

	sal_uInt16 GetNextCode();
	void AddToTable(sal_uInt16 nPrevCode, sal_uInt16 nCodeFirstData);
	void DecompressSome();

	SvStream * pIStream;

	LZWTableEntry * pTable;
	sal_uInt16 nTableSize;

	sal_Bool bEOIFound, bInvert, bFirst;

	sal_uInt16 nOldCode;

	sal_uInt8 * pOutBuf;
	sal_uInt8 * pOutBufData;
	sal_uInt16 nOutBufDataLen;

	sal_uInt8 nInputBitsBuf;
	sal_uInt16 nInputBitsBufSize;
};


#endif