diff options
Diffstat (limited to 'svtools/source/filter.vcl/igif/decode.cxx')
| -rw-r--r-- | svtools/source/filter.vcl/igif/decode.cxx | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/svtools/source/filter.vcl/igif/decode.cxx b/svtools/source/filter.vcl/igif/decode.cxx new file mode 100644 index 000000000000..03a69414cd4b --- /dev/null +++ b/svtools/source/filter.vcl/igif/decode.cxx @@ -0,0 +1,218 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/************************************************************************* + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * Copyright 2000, 2010 Oracle and/or its affiliates. + * + * OpenOffice.org - a multi-platform office productivity suite + * + * This file is part of OpenOffice.org. + * + * OpenOffice.org is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License version 3 + * only, as published by the Free Software Foundation. + * + * OpenOffice.org is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License version 3 for more details + * (a copy is included in the LICENSE file that accompanied this code). + * + * You should have received a copy of the GNU Lesser General Public License + * version 3 along with OpenOffice.org. If not, see + * <http://www.openoffice.org/license.html> + * for a copy of the LGPLv3 License. + * + ************************************************************************/ + +// MARKER(update_precomp.py): autogen include statement, do not remove +#include "precompiled_svtools.hxx" + +#include "decode.hxx" + +// ------------------------------------------------------------------------ + +struct GIFLZWTableEntry +{ + GIFLZWTableEntry* pPrev; + GIFLZWTableEntry* pFirst; + sal_uInt8 nData; +}; + +// ------------------------------------------------------------------------ + +GIFLZWDecompressor::GIFLZWDecompressor( sal_uInt8 cDataSize ) : + nInputBitsBuf ( 0 ), + nOutBufDataLen ( 0 ), + nInputBitsBufSize ( 0 ), + bEOIFound ( sal_False ), + nDataSize ( cDataSize ) +{ + pOutBuf = new sal_uInt8[ 4096 ]; + + nClearCode = 1 << nDataSize; + nEOICode = nClearCode + 1; + nTableSize = nEOICode + 1; + nCodeSize = nDataSize + 1; + nOldCode = 0xffff; + pOutBufData = pOutBuf + 4096; + + pTable = new GIFLZWTableEntry[ 4098 ]; + + for( sal_uInt16 i = 0; i < nTableSize; i++ ) + { + pTable[i].pPrev = NULL; + pTable[i].pFirst = pTable + i; + pTable[i].nData = (sal_uInt8) i; + } +} + +// ------------------------------------------------------------------------ + +GIFLZWDecompressor::~GIFLZWDecompressor() +{ + delete[] pOutBuf; + delete[] pTable; +} + +// ------------------------------------------------------------------------ + +HPBYTE GIFLZWDecompressor::DecompressBlock( HPBYTE pSrc, sal_uInt8 cBufSize, + sal_uLong& rCount, sal_Bool& rEOI ) +{ + sal_uLong nTargetSize = 4096; + sal_uLong nCount = 0; + HPBYTE pTarget = (HPBYTE) rtl_allocateMemory( nTargetSize ); + HPBYTE pTmpTarget = pTarget; + + nBlockBufSize = cBufSize; + nBlockBufPos = 0; + pBlockBuf = pSrc; + + while( ProcessOneCode() ) + { + nCount += nOutBufDataLen; + + if( nCount > nTargetSize ) + { + sal_uLong nNewSize = nTargetSize << 1; + sal_uLong nOffset = pTmpTarget - pTarget; + HPBYTE pTmp = (HPBYTE) rtl_allocateMemory( nNewSize ); + + memcpy( pTmp, pTarget, nTargetSize ); + rtl_freeMemory( pTarget ); + + nTargetSize = nNewSize; + pTmpTarget = ( pTarget = pTmp ) + nOffset; + } + + memcpy( pTmpTarget, pOutBufData, nOutBufDataLen ); + pTmpTarget += nOutBufDataLen; + pOutBufData += nOutBufDataLen; + nOutBufDataLen = 0; + + if ( bEOIFound ) + break; + } + + rCount = nCount; + rEOI = bEOIFound; + + return pTarget; +} + +// ------------------------------------------------------------------------ + +void GIFLZWDecompressor::AddToTable( sal_uInt16 nPrevCode, sal_uInt16 nCodeFirstData ) +{ + GIFLZWTableEntry* pE; + + if( nTableSize < 4096 ) + { + pE = pTable + nTableSize; + pE->pPrev = pTable + nPrevCode; + pE->pFirst = pE->pPrev->pFirst; + pE->nData = pTable[ nCodeFirstData ].pFirst->nData; + nTableSize++; + + if ( ( nTableSize == (sal_uInt16) (1 << nCodeSize) ) && ( nTableSize < 4096 ) ) + nCodeSize++; + } +} + +// ------------------------------------------------------------------------ + +sal_Bool GIFLZWDecompressor::ProcessOneCode() +{ + GIFLZWTableEntry* pE; + sal_uInt16 nCode; + sal_Bool bRet = sal_False; + sal_Bool bEndOfBlock = sal_False; + + while( nInputBitsBufSize < nCodeSize ) + { + if( nBlockBufPos >= nBlockBufSize ) + { + bEndOfBlock = sal_True; + break; + } + + nInputBitsBuf |= ( (sal_uLong) pBlockBuf[ nBlockBufPos++ ] ) << nInputBitsBufSize; + nInputBitsBufSize += 8; + } + + if ( !bEndOfBlock ) + { + // Einen Code aus dem Eingabe-Buffer holen: + nCode = sal::static_int_cast< sal_uInt16 >( + ( (sal_uInt16) nInputBitsBuf ) & ( ~( 0xffff << nCodeSize ) )); + nInputBitsBuf >>= nCodeSize; + nInputBitsBufSize = nInputBitsBufSize - nCodeSize; + + if ( nCode < nClearCode ) + { + if ( nOldCode != 0xffff ) + AddToTable( nOldCode, nCode ); + } + else if ( ( nCode > nEOICode ) && ( nCode <= nTableSize ) ) + { + if ( nCode == nTableSize ) + AddToTable( nOldCode, nOldCode ); + else + AddToTable( nOldCode, nCode ); + } + else + { + if ( nCode == nClearCode ) + { + nTableSize = nEOICode + 1; + nCodeSize = nDataSize + 1; + nOldCode = 0xffff; + nOutBufDataLen = 0; + } + else + bEOIFound = sal_True; + + return sal_True; + } + + nOldCode = nCode; + + // Zeichen(/-folge) des Codes nCode in den Ausgabe-Buffer schreiben: + pE = pTable + nCode; + do + { + nOutBufDataLen++; + *(--pOutBufData) = pE->nData; + pE = pE->pPrev; + } + while( pE ); + + bRet = sal_True; + } + + return bRet; +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |