xref: /aoo41x/main/vcl/source/gdi/dibtools.cxx (revision 4b444595)

/**************************************************************
 *
 * 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
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 *************************************************************/

// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_vcl.hxx"

#include <vcl/salbtype.hxx>
#include <vcl/dibtools.hxx>
#include <tools/zcodec.hxx>
#include <tools/stream.hxx>
#include <vcl/bitmapex.hxx>
#include <vcl/bmpacc.hxx>
#include <vcl/outdev.hxx>

//////////////////////////////////////////////////////////////////////////////
// - Defines -

#define DIBCOREHEADERSIZE		( 12UL )
#define DIBINFOHEADERSIZE		( sizeof(DIBInfoHeader) )
#define DIBV5HEADERSIZE		    ( sizeof(DIBV5Header) )

//////////////////////////////////////////////////////////////////////////////
// - Compression defines

#define COMPRESS_OWN				('S'|('D'<<8UL))
#define COMPRESS_NONE				( 0UL )
#define RLE_8						( 1UL )
#define RLE_4						( 2UL )
#define BITFIELDS					( 3UL )
#define ZCOMPRESS					( COMPRESS_OWN | 0x01000000UL ) /* == 'SD01' (binary) */

//////////////////////////////////////////////////////////////////////////////
// - DIBInfoHeader and DIBV5Header

typedef sal_Int32 FXPT2DOT30;

struct CIEXYZ
{
    FXPT2DOT30      aXyzX;
    FXPT2DOT30      aXyzY;
    FXPT2DOT30      aXyzZ;

    CIEXYZ()
    :   aXyzX(0L),
        aXyzY(0L),
        aXyzZ(0L)
    {}

    ~CIEXYZ()
    {}
};

struct CIEXYZTriple
{
    CIEXYZ          aXyzRed;
    CIEXYZ          aXyzGreen;
    CIEXYZ          aXyzBlue;

    CIEXYZTriple()
    :   aXyzRed(),
        aXyzGreen(),
        aXyzBlue()
    {}

    ~CIEXYZTriple()
    {}
};

struct DIBInfoHeader
{
    sal_uInt32      nSize;
    sal_Int32       nWidth;
    sal_Int32       nHeight;
    sal_uInt16      nPlanes;
    sal_uInt16      nBitCount;
    sal_uInt32      nCompression;
    sal_uInt32      nSizeImage;
    sal_Int32       nXPelsPerMeter;
    sal_Int32       nYPelsPerMeter;
    sal_uInt32      nColsUsed;
    sal_uInt32      nColsImportant;

    DIBInfoHeader()
    :   nSize(0UL),
        nWidth(0UL),
        nHeight(0UL),
        nPlanes(0),
        nBitCount(0),
        nCompression(0),
        nSizeImage(0),
        nXPelsPerMeter(0UL),
        nYPelsPerMeter(0UL),
        nColsUsed(0UL),
        nColsImportant(0UL)
    {}

    ~DIBInfoHeader()
    {}
};

struct DIBV5Header : public DIBInfoHeader
{
    sal_uInt32      nV5RedMask;
    sal_uInt32      nV5GreenMask;
    sal_uInt32      nV5BlueMask;
    sal_uInt32      nV5AlphaMask;
    sal_uInt32      nV5CSType;
    CIEXYZTriple    aV5Endpoints;
    sal_uInt32      nV5GammaRed;
    sal_uInt32      nV5GammaGreen;
    sal_uInt32      nV5GammaBlue;
    sal_uInt32      nV5Intent;
    sal_uInt32      nV5ProfileData;
    sal_uInt32      nV5ProfileSize;
    sal_uInt32      nV5Reserved;

    DIBV5Header()
    :   DIBInfoHeader(),
        nV5RedMask(0UL),
        nV5GreenMask(0UL),
        nV5BlueMask(0UL),
        nV5AlphaMask(0UL),
        nV5CSType(0UL),
        aV5Endpoints(),
        nV5GammaRed(0UL),
        nV5GammaGreen(0UL),
        nV5GammaBlue(0UL),
        nV5Intent(0UL),
        nV5ProfileData(0UL),
        nV5ProfileSize(0UL),
        nV5Reserved(0UL)
    {}

    ~DIBV5Header()
    {}
};

//////////////////////////////////////////////////////////////////////////////

namespace
{
    inline sal_uInt16 discretizeBitcount( sal_uInt16 nInputCount )
    {
        return ( nInputCount <= 1 ) ? 1 :
               ( nInputCount <= 4 ) ? 4 :
               ( nInputCount <= 8 ) ? 8 : 24;
    }

    inline bool isBitfieldCompression( sal_uLong nScanlineFormat )
    {
        return (BMP_FORMAT_16BIT_TC_LSB_MASK == nScanlineFormat) || (BMP_FORMAT_32BIT_TC_MASK == nScanlineFormat);
    }
}

//////////////////////////////////////////////////////////////////////////////

bool ImplReadDIBInfoHeader(SvStream& rIStm, DIBV5Header& rHeader, bool& bTopDown)
{
	// BITMAPINFOHEADER or BITMAPCOREHEADER or BITMAPV5HEADER
    const sal_Size aStartPos(rIStm.Tell());
	rIStm >> rHeader.nSize;

	// BITMAPCOREHEADER
	if ( rHeader.nSize == DIBCOREHEADERSIZE )
	{
		sal_Int16 nTmp16;

		rIStm >> nTmp16; rHeader.nWidth = nTmp16;
		rIStm >> nTmp16; rHeader.nHeight = nTmp16;
		rIStm >> rHeader.nPlanes;
		rIStm >> rHeader.nBitCount;
	}
	else
	{
        // BITMAPCOREHEADER, BITMAPV5HEADER or unknown. Read as far as possible
        sal_Size nUsed(sizeof(rHeader.nSize));

        // read DIBInfoHeader entries
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nWidth; nUsed += sizeof(rHeader.nWidth); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nHeight; nUsed += sizeof(rHeader.nHeight); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nPlanes; nUsed += sizeof(rHeader.nPlanes); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nBitCount;  nUsed += sizeof(rHeader.nBitCount); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nCompression;  nUsed += sizeof(rHeader.nCompression); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nSizeImage;  nUsed += sizeof(rHeader.nSizeImage); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nXPelsPerMeter;  nUsed += sizeof(rHeader.nXPelsPerMeter); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nYPelsPerMeter;  nUsed += sizeof(rHeader.nYPelsPerMeter); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nColsUsed;  nUsed += sizeof(rHeader.nColsUsed); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nColsImportant;  nUsed += sizeof(rHeader.nColsImportant); }

        // read DIBV5HEADER members
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nV5RedMask; nUsed += sizeof(rHeader.nV5RedMask); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nV5GreenMask; nUsed += sizeof(rHeader.nV5GreenMask);  }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nV5BlueMask; nUsed += sizeof(rHeader.nV5BlueMask);  }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nV5AlphaMask; nUsed += sizeof(rHeader.nV5AlphaMask);  }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nV5CSType; nUsed += sizeof(rHeader.nV5CSType);  }

        // read contained CIEXYZTriple's
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.aV5Endpoints.aXyzRed.aXyzX; nUsed += sizeof(rHeader.aV5Endpoints.aXyzRed.aXyzX); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.aV5Endpoints.aXyzRed.aXyzY; nUsed += sizeof(rHeader.aV5Endpoints.aXyzRed.aXyzY); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.aV5Endpoints.aXyzRed.aXyzZ; nUsed += sizeof(rHeader.aV5Endpoints.aXyzRed.aXyzZ); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.aV5Endpoints.aXyzGreen.aXyzX; nUsed += sizeof(rHeader.aV5Endpoints.aXyzGreen.aXyzX); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.aV5Endpoints.aXyzGreen.aXyzY; nUsed += sizeof(rHeader.aV5Endpoints.aXyzGreen.aXyzY); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.aV5Endpoints.aXyzGreen.aXyzZ; nUsed += sizeof(rHeader.aV5Endpoints.aXyzGreen.aXyzZ); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.aV5Endpoints.aXyzBlue.aXyzX; nUsed += sizeof(rHeader.aV5Endpoints.aXyzBlue.aXyzX); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.aV5Endpoints.aXyzBlue.aXyzY; nUsed += sizeof(rHeader.aV5Endpoints.aXyzBlue.aXyzY); }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.aV5Endpoints.aXyzBlue.aXyzZ; nUsed += sizeof(rHeader.aV5Endpoints.aXyzBlue.aXyzZ); }

        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nV5GammaRed; nUsed += sizeof(rHeader.nV5GammaRed);  }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nV5GammaGreen; nUsed += sizeof(rHeader.nV5GammaGreen);  }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nV5GammaBlue; nUsed += sizeof(rHeader.nV5GammaBlue);  }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nV5Intent; nUsed += sizeof(rHeader.nV5Intent);  }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nV5ProfileData; nUsed += sizeof(rHeader.nV5ProfileData);  }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nV5ProfileSize; nUsed += sizeof(rHeader.nV5ProfileSize);  }
        if(nUsed < rHeader.nSize) { rIStm >> rHeader.nV5Reserved; nUsed += sizeof(rHeader.nV5Reserved);  }

        // seek to EndPos
        rIStm.Seek(aStartPos + rHeader.nSize);
    }

    if ( rHeader.nHeight < 0 )
	{
		bTopDown = true;
		rHeader.nHeight *= -1;
	}
	else
    {
		bTopDown = false;
    }

	if ( rHeader.nWidth < 0 )
    {
		rIStm.SetError( SVSTREAM_FILEFORMAT_ERROR );
    }

    // #144105# protect a little against damaged files
    if( rHeader.nSizeImage > ( 16 * static_cast< sal_uInt32 >( rHeader.nWidth * rHeader.nHeight ) ) )
    {
        rHeader.nSizeImage = 0;
    }

	return( ( rHeader.nPlanes == 1 ) && ( rIStm.GetError() == 0UL ) );
}

bool ImplReadDIBPalette( SvStream& rIStm, BitmapWriteAccess& rAcc, bool bQuad )
{
	const sal_uInt16	nColors = rAcc.GetPaletteEntryCount();
	const sal_uLong 	nPalSize = nColors * ( bQuad ? 4UL : 3UL );
	BitmapColor 	aPalColor;

	sal_uInt8* pEntries = new sal_uInt8[ nPalSize ];
	rIStm.Read( pEntries, nPalSize );

	sal_uInt8* pTmpEntry = pEntries;
	for( sal_uInt16 i = 0; i < nColors; i++ )
	{
		aPalColor.SetBlue( *pTmpEntry++ );
		aPalColor.SetGreen( *pTmpEntry++ );
		aPalColor.SetRed( *pTmpEntry++ );

		if( bQuad )
			pTmpEntry++;

		rAcc.SetPaletteColor( i, aPalColor );
	}

	delete[] pEntries;

	return( rIStm.GetError() == 0UL );
}

void ImplDecodeRLE( sal_uInt8* pBuffer, DIBV5Header& rHeader, BitmapWriteAccess& rAcc, bool bRLE4 )
{
	Scanline	pRLE = pBuffer;
	long		nY = rHeader.nHeight - 1L;
	const sal_uLong	nWidth = rAcc.Width();
	sal_uLong		nCountByte;
	sal_uLong		nRunByte;
	sal_uLong		nX = 0UL;
	sal_uInt8		cTmp;
	bool		bEndDecoding = false;

	do
	{
		if( ( nCountByte = *pRLE++ ) == 0 )
		{
			nRunByte = *pRLE++;

			if( nRunByte > 2 )
			{
				if( bRLE4 )
				{
					nCountByte = nRunByte >> 1;

					for( sal_uLong i = 0UL; i < nCountByte; i++ )
					{
						cTmp = *pRLE++;

						if( nX < nWidth )
							rAcc.SetPixelIndex( nY, nX++, cTmp >> 4 );

						if( nX < nWidth )
							rAcc.SetPixelIndex( nY, nX++, cTmp & 0x0f );
					}

					if( nRunByte & 1 )
					{
						if( nX < nWidth )
							rAcc.SetPixelIndex( nY, nX++, *pRLE >> 4 );

						pRLE++;
					}

					if( ( ( nRunByte + 1 ) >> 1 ) & 1 )
						pRLE++;
				}
				else
				{
					for( sal_uLong i = 0UL; i < nRunByte; i++ )
					{
						if( nX < nWidth )
							rAcc.SetPixelIndex( nY, nX++, *pRLE );

						pRLE++;
					}

					if( nRunByte & 1 )
						pRLE++;
				}
			}
			else if( !nRunByte )
			{
				nY--;
				nX = 0UL;
			}
			else if( nRunByte == 1 )
				bEndDecoding = true;
			else
			{
				nX += *pRLE++;
				nY -= *pRLE++;
			}
		}
		else
		{
			cTmp = *pRLE++;

			if( bRLE4 )
			{
				nRunByte = nCountByte >> 1;

				for( sal_uLong i = 0UL; i < nRunByte; i++ )
				{
					if( nX < nWidth )
						rAcc.SetPixelIndex( nY, nX++, cTmp >> 4 );

					if( nX < nWidth )
						rAcc.SetPixelIndex( nY, nX++, cTmp & 0x0f );
				}

				if( ( nCountByte & 1 ) && ( nX < nWidth ) )
					rAcc.SetPixelIndex( nY, nX++, cTmp >> 4 );
			}
			else
			{
				for( sal_uLong i = 0UL; ( i < nCountByte ) && ( nX < nWidth ); i++ )
					rAcc.SetPixelIndex( nY, nX++, cTmp );
			}
		}
	}
	while ( !bEndDecoding && ( nY >= 0L ) );
}

bool ImplReadDIBBits(SvStream& rIStm, DIBV5Header& rHeader, BitmapWriteAccess& rAcc, BitmapWriteAccess* pAccAlpha, bool bTopDown, bool& rAlphaUsed)
{
    const sal_Int64 nBitsPerLine (static_cast<sal_Int64>(rHeader.nWidth) * static_cast<sal_Int64>(rHeader.nBitCount));
    if (nBitsPerLine > SAL_MAX_UINT32)
        return false;

	const sal_uLong nAlignedWidth = AlignedWidth4Bytes(static_cast<sal_uLong>(nBitsPerLine));
	sal_uInt32 nRMask(( rHeader.nBitCount == 16 ) ? 0x00007c00UL : 0x00ff0000UL);
	sal_uInt32 nGMask(( rHeader.nBitCount == 16 ) ? 0x000003e0UL : 0x0000ff00UL);
	sal_uInt32 nBMask(( rHeader.nBitCount == 16 ) ? 0x0000001fUL : 0x000000ffUL);
	bool bNative(false);
	bool bTCMask(!pAccAlpha && ((16 == rHeader.nBitCount) || (32 == rHeader.nBitCount)));
	bool bRLE((RLE_8 == rHeader.nCompression && 8 == rHeader.nBitCount) || (RLE_4 == rHeader.nCompression && 4 == rHeader.nBitCount));

	// Is native format?
	switch(rAcc.GetScanlineFormat())
	{
		case( BMP_FORMAT_1BIT_MSB_PAL ):
		case( BMP_FORMAT_4BIT_MSN_PAL ):
		case( BMP_FORMAT_8BIT_PAL ):
		case( BMP_FORMAT_24BIT_TC_BGR ):
        {
			bNative = ( ( static_cast< bool >(rAcc.IsBottomUp()) != bTopDown ) && !bRLE && !bTCMask && ( rAcc.GetScanlineSize() == nAlignedWidth ) );
		    break;
        }

		default:
        {
    		break;
        }
	}

    // Read data
	if(bNative)
	{
		rIStm.Read(rAcc.GetBuffer(), rHeader.nHeight * nAlignedWidth);
	}
	else
	{
		// Read color mask
        if(bTCMask && BITFIELDS == rHeader.nCompression)
        {
            rIStm.SeekRel( -12L );
            rIStm >> nRMask;
            rIStm >> nGMask;
            rIStm >> nBMask;
        }

		if(bRLE)
		{
			if(!rHeader.nSizeImage)
			{
				const sal_uLong nOldPos(rIStm.Tell());

				rIStm.Seek(STREAM_SEEK_TO_END);
				rHeader.nSizeImage = rIStm.Tell() - nOldPos;
				rIStm.Seek(nOldPos);
			}

			sal_uInt8* pBuffer = (sal_uInt8*)rtl_allocateMemory(rHeader.nSizeImage);
			rIStm.Read((char*)pBuffer, rHeader.nSizeImage);
			ImplDecodeRLE(pBuffer, rHeader, rAcc, RLE_4 == rHeader.nCompression);
			rtl_freeMemory(pBuffer);
		}
		else
		{
			const long nWidth(rHeader.nWidth);
			const long nHeight(rHeader.nHeight);
			sal_uInt8* pBuf = new sal_uInt8[nAlignedWidth];

			const long nI(bTopDown ? 1 : -1);
			long nY(bTopDown ? 0 : nHeight - 1);
			long nCount(nHeight);

			switch(rHeader.nBitCount)
			{
				case( 1 ):
				{
					sal_uInt8*	pTmp;
					sal_uInt8	cTmp;

					for( ; nCount--; nY += nI )
					{
						rIStm.Read( pTmp = pBuf, nAlignedWidth );
						cTmp = *pTmp++;

						for( long nX = 0L, nShift = 8L; nX < nWidth; nX++ )
						{
							if( !nShift )
							{
								nShift = 8L,
								cTmp = *pTmp++;
							}

							rAcc.SetPixelIndex( nY, nX, (cTmp >> --nShift) & 1);
						}
					}
				}
				break;

				case( 4 ):
				{
					sal_uInt8*	pTmp;
					sal_uInt8	cTmp;

					for( ; nCount--; nY += nI )
					{
						rIStm.Read( pTmp = pBuf, nAlignedWidth );
						cTmp = *pTmp++;

						for( long nX = 0L, nShift = 2L; nX < nWidth; nX++ )
						{
							if( !nShift )
							{
								nShift = 2UL,
								cTmp = *pTmp++;
							}

							rAcc.SetPixelIndex( nY, nX, (cTmp >> ( --nShift << 2UL ) ) & 0x0f);
						}
					}
				}
				break;

				case( 8 ):
				{
					sal_uInt8*	pTmp;

					for( ; nCount--; nY += nI )
					{
						rIStm.Read( pTmp = pBuf, nAlignedWidth );

						for( long nX = 0L; nX < nWidth; nX++ )
							rAcc.SetPixelIndex( nY, nX, *pTmp++ );
					}
				}
				break;

				case( 16 ):
				{
					ColorMask	aMask( nRMask, nGMask, nBMask );
					BitmapColor aColor;
					sal_uInt16* 	pTmp16;

					for( ; nCount--; nY += nI )
					{
						rIStm.Read( (char*)( pTmp16 = (sal_uInt16*) pBuf ), nAlignedWidth );

						for( long nX = 0L; nX < nWidth; nX++ )
						{
							aMask.GetColorFor16BitLSB( aColor, (sal_uInt8*) pTmp16++ );
							rAcc.SetPixel( nY, nX, aColor );
						}
					}
				}
				break;

				case( 24 ):
				{
					BitmapColor aPixelColor;
					sal_uInt8*		pTmp;

					for( ; nCount--; nY += nI )
					{
						rIStm.Read( pTmp = pBuf, nAlignedWidth );

						for( long nX = 0L; nX < nWidth; nX++ )
						{
							aPixelColor.SetBlue( *pTmp++ );
							aPixelColor.SetGreen( *pTmp++ );
							aPixelColor.SetRed( *pTmp++ );
							rAcc.SetPixel( nY, nX, aPixelColor );
						}
					}
				}
				break;

				case( 32 ):
				{
					ColorMask aMask(nRMask, nGMask, nBMask);
					BitmapColor aColor;
					sal_uInt32* pTmp32;

                    if(pAccAlpha)
                    {
                        sal_uInt8 aAlpha;

                        for( ; nCount--; nY += nI )
                        {
                            rIStm.Read( (char*)( pTmp32 = (sal_uInt32*) pBuf ), nAlignedWidth );

                            for( long nX = 0L; nX < nWidth; nX++ )
                            {
                                aMask.GetColorAndAlphaFor32Bit( aColor, aAlpha, (sal_uInt8*) pTmp32++ );
                                rAcc.SetPixel( nY, nX, aColor );
                                pAccAlpha->SetPixelIndex(nY, nX, sal_uInt8(0xff) - aAlpha);
                                rAlphaUsed |= bool(0xff != aAlpha);
                            }
                        }
                    }
                    else
                    {
                        for( ; nCount--; nY += nI )
                        {
                            rIStm.Read( (char*)( pTmp32 = (sal_uInt32*) pBuf ), nAlignedWidth );

                            for( long nX = 0L; nX < nWidth; nX++ )
                            {
                                aMask.GetColorFor32Bit( aColor, (sal_uInt8*) pTmp32++ );
                                rAcc.SetPixel( nY, nX, aColor );
                            }
                        }
                    }
				}
			}

			delete[] pBuf;
		}
	}

	return( rIStm.GetError() == 0UL );
}

bool ImplReadDIBBody( SvStream& rIStm, Bitmap& rBmp, Bitmap* pBmpAlpha, sal_uLong nOffset )
{
    DIBV5Header aHeader;
    const sal_uLong nStmPos = rIStm.Tell();
    bool bRet( false );
    bool bTopDown( false );

    if ( ImplReadDIBInfoHeader( rIStm, aHeader, bTopDown )
         && aHeader.nWidth != 0
         && aHeader.nHeight != 0
         && aHeader.nBitCount != 0 )
    {
        if ( nOffset > 0 && aHeader.nSize > nOffset )
        {
            // Header size claims to extend into the image data.
            // Looks like an error.
            return false;
        }

		const sal_uInt16 nBitCount(discretizeBitcount(aHeader.nBitCount));
		const Size aSizePixel(aHeader.nWidth, aHeader.nHeight);
		BitmapPalette aDummyPal;
		Bitmap aNewBmp(aSizePixel, nBitCount, &aDummyPal);
		Bitmap aNewBmpAlpha;
		BitmapWriteAccess* pAcc = aNewBmp.AcquireWriteAccess();
        BitmapWriteAccess* pAccAlpha = 0;
        bool bAlphaPossible(pBmpAlpha && aHeader.nBitCount == 32);

        if(bAlphaPossible)
        {
            const bool bRedSet(0 != aHeader.nV5RedMask);
            const bool bGreenSet(0 != aHeader.nV5GreenMask);
            const bool bBlueSet(0 != aHeader.nV5BlueMask);

            // some clipboard entries have alpha mask on zero to say that there is
            // no alpha; do only use this when the other masks are set. The MS docu
            // says that that masks are only to be set when bV5Compression is set to
            // BI_BITFIELDS, but there seem to exist a wild variety of usages...
            if((bRedSet || bGreenSet || bBlueSet) && (0 == aHeader.nV5AlphaMask))
            {
                bAlphaPossible = false;
            }
        }

        if(bAlphaPossible)
        {
            aNewBmpAlpha = Bitmap(aSizePixel, 8);
            pAccAlpha = aNewBmpAlpha.AcquireWriteAccess();
        }

		if(pAcc)
		{
			sal_uInt16 nColors(0);
			SvStream* pIStm;
			SvMemoryStream* pMemStm = NULL;
			sal_uInt8* pData = NULL;

			if(nBitCount <= 8)
			{
				if(aHeader.nColsUsed)
                {
					nColors = (sal_uInt16)aHeader.nColsUsed;
                }
				else
                {
					nColors = ( 1 << aHeader.nBitCount );
                }
			}

			if(ZCOMPRESS == aHeader.nCompression)
			{
				ZCodec aCodec;
				sal_uInt32 nCodedSize(0);
                sal_uInt32  nUncodedSize(0);
				sal_uLong nCodedPos(0);

				// read coding information
				rIStm >> nCodedSize >> nUncodedSize >> aHeader.nCompression;
				pData = (sal_uInt8*) rtl_allocateMemory( nUncodedSize );

				// decode buffer
				nCodedPos = rIStm.Tell();
				aCodec.BeginCompression();
				aCodec.Read( rIStm, pData, nUncodedSize );
				aCodec.EndCompression();

				// skip unread bytes from coded buffer
				rIStm.SeekRel( nCodedSize - ( rIStm.Tell() - nCodedPos ) );

				// set decoded bytes to memory stream,
				// from which we will read the bitmap data
				pIStm = pMemStm = new SvMemoryStream;
				pMemStm->SetBuffer( (char*) pData, nUncodedSize, false, nUncodedSize );
				nOffset = 0;
			}
			else
            {
				pIStm = &rIStm;
            }

			// read palette
			if(nColors)
			{
				pAcc->SetPaletteEntryCount(nColors);
				ImplReadDIBPalette(*pIStm, *pAcc, aHeader.nSize != DIBCOREHEADERSIZE);
			}

			// read bits
            bool bAlphaUsed(false);

			if(!pIStm->GetError())
			{
				if(nOffset)
                {
					pIStm->SeekRel(nOffset - (pIStm->Tell() - nStmPos));
                }

				bRet = ImplReadDIBBits(*pIStm, aHeader, *pAcc, pAccAlpha, bTopDown, bAlphaUsed);

				if(bRet && aHeader.nXPelsPerMeter && aHeader.nYPelsPerMeter)
				{
					MapMode aMapMode(
                        MAP_MM,
                        Point(),
						Fraction(1000, aHeader.nXPelsPerMeter),
						Fraction(1000, aHeader.nYPelsPerMeter));

					aNewBmp.SetPrefMapMode(aMapMode);
					aNewBmp.SetPrefSize(Size(aHeader.nWidth, aHeader.nHeight));
				}
			}

			if( pData )
            {
				rtl_freeMemory(pData);
            }

			delete pMemStm;
			aNewBmp.ReleaseAccess(pAcc);

            if(bAlphaPossible)
            {
                aNewBmpAlpha.ReleaseAccess(pAccAlpha);

                if(!bAlphaUsed)
                {
                    bAlphaPossible = false;
                }
            }

			if(bRet)
            {
                rBmp = aNewBmp;

                if(bAlphaPossible)
                {
                    *pBmpAlpha = aNewBmpAlpha;
                }
            }
		}
	}

	return bRet;
}

bool ImplReadDIBFileHeader( SvStream& rIStm, sal_uLong& rOffset )
{
    bool bRet = false;

    const sal_Int64 nSavedStreamPos( rIStm.Tell() );
    const sal_Int64 nStreamLength( rIStm.Seek( STREAM_SEEK_TO_END ) );
    rIStm.Seek( nSavedStreamPos );

    sal_uInt16 nTmp16 = 0;
    rIStm >> nTmp16;

    if ( ( 0x4D42 == nTmp16 ) || ( 0x4142 == nTmp16 ) )
    {
        sal_uInt32 nTmp32;
        if ( 0x4142 == nTmp16 )
        {
            rIStm.SeekRel( 12L );
            rIStm >> nTmp16;
            rIStm.SeekRel( 8L );
            rIStm >> nTmp32;
            rOffset = nTmp32 - 28UL;
            bRet = ( 0x4D42 == nTmp16 );
        }
        else // 0x4D42 == nTmp16, 'MB' from BITMAPFILEHEADER
        {
            rIStm.SeekRel( 8L );        // we are on bfSize member of BITMAPFILEHEADER, forward to bfOffBits
            rIStm >> nTmp32;            // read bfOffBits
            rOffset = nTmp32 - 14UL;    // adapt offset by sizeof(BITMAPFILEHEADER)
            bRet = ( rIStm.GetError() == 0UL );
        }

        if ( rOffset >= nStreamLength )
        {
            // Offset claims that image starts past the end of the
            // stream.  Unlikely.
            rIStm.SetError( SVSTREAM_FILEFORMAT_ERROR );
            bRet = false;
        }
    }
    else
        rIStm.SetError( SVSTREAM_FILEFORMAT_ERROR );

    return bRet;
}

bool ImplWriteDIBPalette( SvStream& rOStm, BitmapReadAccess& rAcc )
{
	const sal_uInt16	nColors = rAcc.GetPaletteEntryCount();
	const sal_uLong 	nPalSize = nColors * 4UL;
	sal_uInt8*			pEntries = new sal_uInt8[ nPalSize ];
	sal_uInt8*			pTmpEntry = pEntries;
	BitmapColor 	aPalColor;

	for( sal_uInt16 i = 0; i < nColors; i++ )
	{
		const BitmapColor& rPalColor = rAcc.GetPaletteColor( i );

		*pTmpEntry++ = rPalColor.GetBlue();
		*pTmpEntry++ = rPalColor.GetGreen();
		*pTmpEntry++ = rPalColor.GetRed();
		*pTmpEntry++ = 0;
	}

	rOStm.Write( pEntries, nPalSize );
	delete[] pEntries;

	return( rOStm.GetError() == 0UL );
}

bool ImplWriteRLE( SvStream& rOStm, BitmapReadAccess& rAcc, bool bRLE4 )
{
	const sal_uLong nWidth = rAcc.Width();
	const sal_uLong nHeight = rAcc.Height();
	sal_uLong		nX;
	sal_uLong		nSaveIndex;
	sal_uLong		nCount;
	sal_uLong		nBufCount;
	sal_uInt8*		pBuf = new sal_uInt8[ ( nWidth << 1 ) + 2 ];
	sal_uInt8*		pTmp;
	sal_uInt8		cPix;
	sal_uInt8		cLast;
	bool		bFound;

	for ( long nY = nHeight - 1L; nY >= 0L; nY-- )
	{
		pTmp = pBuf;
		nX = nBufCount = 0UL;

		while( nX < nWidth )
		{
			nCount = 1L;
			cPix = rAcc.GetPixelIndex( nY, nX++ );

			while( ( nX < nWidth ) && ( nCount < 255L )
				&& ( cPix == rAcc.GetPixelIndex( nY, nX ) ) )
			{
				nX++;
				nCount++;
			}

			if ( nCount > 1 )
			{
				*pTmp++ = (sal_uInt8) nCount;
				*pTmp++ = ( bRLE4 ? ( ( cPix << 4 ) | cPix ) : cPix );
				nBufCount += 2;
			}
			else
			{
				cLast = cPix;
				nSaveIndex = nX - 1UL;
				bFound = false;

				while( ( nX < nWidth ) && ( nCount < 256L )
					&& ( cPix = rAcc.GetPixelIndex( nY, nX ) ) != cLast )
				{
					nX++; nCount++;
					cLast = cPix;
					bFound = true;
				}

				if ( bFound )
					nX--;

				if ( nCount > 3 )
				{
					*pTmp++ = 0;
					*pTmp++ = (sal_uInt8) --nCount;

					if( bRLE4 )
					{
						for ( sal_uLong i = 0; i < nCount; i++, pTmp++ )
						{
							*pTmp = rAcc.GetPixelIndex( nY, nSaveIndex++ ) << 4;

							if ( ++i < nCount )
								*pTmp |= rAcc.GetPixelIndex( nY, nSaveIndex++ );
						}

						nCount = ( nCount + 1 ) >> 1;
					}
					else
					{
						for( sal_uLong i = 0UL; i < nCount; i++ )
							*pTmp++ = rAcc.GetPixelIndex( nY, nSaveIndex++ );
					}

					if ( nCount & 1 )
					{
						*pTmp++ = 0;
						nBufCount += ( nCount + 3 );
					}
					else
						nBufCount += ( nCount + 2 );
				}
				else
				{
					*pTmp++ = 1;
					*pTmp++ = rAcc.GetPixelIndex( nY, nSaveIndex ) << (bRLE4 ? 4 : 0);

					if ( nCount == 3 )
					{
						*pTmp++ = 1;
						*pTmp++ = rAcc.GetPixelIndex( nY, ++nSaveIndex ) << ( bRLE4 ? 4 : 0 );
						nBufCount += 4;
					}
					else
						nBufCount += 2;
				}
			}
		}

		pBuf[ nBufCount++ ] = 0;
		pBuf[ nBufCount++ ] = 0;

		rOStm.Write( pBuf, nBufCount );
	}

	rOStm << (sal_uInt8) 0;
	rOStm << (sal_uInt8) 1;

	delete[] pBuf;

	return( rOStm.GetError() == 0UL );
}

bool ImplWriteDIBBits(SvStream& rOStm, BitmapReadAccess& rAcc, BitmapReadAccess* pAccAlpha, sal_uLong nCompression, sal_uInt32& rImageSize)
{
	if(!pAccAlpha && BITFIELDS == nCompression)
	{
		const ColorMask&	rMask = rAcc.GetColorMask();
		SVBT32				aVal32;

		UInt32ToSVBT32( rMask.GetRedMask(), aVal32 );
		rOStm.Write( (sal_uInt8*) aVal32, 4UL );

		UInt32ToSVBT32( rMask.GetGreenMask(), aVal32 );
		rOStm.Write( (sal_uInt8*) aVal32, 4UL );

		UInt32ToSVBT32( rMask.GetBlueMask(), aVal32 );
		rOStm.Write( (sal_uInt8*) aVal32, 4UL );

		rImageSize = rOStm.Tell();

		if( rAcc.IsBottomUp() )
			rOStm.Write( rAcc.GetBuffer(), rAcc.Height() * rAcc.GetScanlineSize() );
		else
		{
			for( long nY = rAcc.Height() - 1, nScanlineSize = rAcc.GetScanlineSize(); nY >= 0L; nY-- )
				rOStm.Write( rAcc.GetScanline( nY ), nScanlineSize );
		}
	}
	else if(!pAccAlpha && ((RLE_4 == nCompression) || (RLE_8 == nCompression)))
	{
		rImageSize = rOStm.Tell();
		ImplWriteRLE( rOStm, rAcc, RLE_4 == nCompression );
	}
	else if(!nCompression)
	{
        // #i5xxx# Limit bitcount to 24bit, the 32 bit cases are not
        // handled properly below (would have to set color masks, and
        // nCompression=BITFIELDS - but color mask is not set for
        // formats != *_TC_*). Note that this very problem might cause
        // trouble at other places - the introduction of 32 bit RGBA
        // bitmaps is relatively recent.
        // #i59239# discretize bitcount for aligned width to 1,4,8,24
        // (other cases are not written below)
        const sal_uInt16 nBitCount(pAccAlpha ? 32 : discretizeBitcount(static_cast< sal_uInt16 >(rAcc.GetBitCount())));
        const sal_uLong nAlignedWidth(AlignedWidth4Bytes(rAcc.Width() * nBitCount));
		bool bNative(false);

		switch(rAcc.GetScanlineFormat())
		{
			case( BMP_FORMAT_1BIT_MSB_PAL ):
			case( BMP_FORMAT_4BIT_MSN_PAL ):
			case( BMP_FORMAT_8BIT_PAL ):
			case( BMP_FORMAT_24BIT_TC_BGR ):
			{
				if(!pAccAlpha && rAcc.IsBottomUp() && (rAcc.GetScanlineSize() == nAlignedWidth))
                {
					bNative = true;
                }

                break;
			}

			default:
            {
                break;
            }
		}

		rImageSize = rOStm.Tell();

		if(bNative)
        {
			rOStm.Write(rAcc.GetBuffer(), nAlignedWidth * rAcc.Height());
        }
		else
		{
			const long nWidth(rAcc.Width());
			const long nHeight(rAcc.Height());
			sal_uInt8* pBuf = new sal_uInt8[ nAlignedWidth ];
			sal_uInt8* pTmp(0);
			sal_uInt8 cTmp(0);

			switch( nBitCount )
			{
				case( 1 ):
				{
					for( long nY = nHeight - 1; nY >= 0L; nY-- )
					{
						pTmp = pBuf;
						cTmp = 0;

						for( long nX = 0L, nShift = 8L; nX < nWidth; nX++ )
						{
							if( !nShift )
							{
								nShift = 8L;
								*pTmp++ = cTmp;
								cTmp = 0;
							}

							cTmp |= rAcc.GetPixelIndex( nY, nX ) << --nShift;
						}

						*pTmp = cTmp;
						rOStm.Write( pBuf, nAlignedWidth );
					}
				}
				break;

				case( 4 ):
				{
					for( long nY = nHeight - 1; nY >= 0L; nY-- )
					{
						pTmp = pBuf;
						cTmp = 0;

						for( long nX = 0L, nShift = 2L; nX < nWidth; nX++ )
						{
							if( !nShift )
							{
								nShift = 2L;
								*pTmp++ = cTmp;
								cTmp = 0;
							}

							cTmp |= rAcc.GetPixelIndex( nY, nX ) << ( --nShift << 2L );
						}
						*pTmp = cTmp;
						rOStm.Write( pBuf, nAlignedWidth );
					}
				}
				break;

				case( 8 ):
				{
					for( long nY = nHeight - 1; nY >= 0L; nY-- )
					{
						pTmp = pBuf;

						for( long nX = 0L; nX < nWidth; nX++ )
							*pTmp++ = rAcc.GetPixelIndex( nY, nX );

						rOStm.Write( pBuf, nAlignedWidth );
					}
				}
				break;

                // #i59239# fallback to 24 bit format, if bitcount is non-default
                default:
                    // FALLTHROUGH intended
				case( 24 ):
				{
					BitmapColor aPixelColor;
                    const bool bWriteAlpha(32 == nBitCount && pAccAlpha);

					for( long nY = nHeight - 1; nY >= 0L; nY-- )
					{
						pTmp = pBuf;

						for( long nX = 0L; nX < nWidth; nX++ )
						{
                            // when alpha is used, this may be non-24bit main bitmap, so use GetColor
                            // instead of GetPixel to ensure RGB value
                            aPixelColor = rAcc.GetColor( nY, nX );

							*pTmp++ = aPixelColor.GetBlue();
							*pTmp++ = aPixelColor.GetGreen();
							*pTmp++ = aPixelColor.GetRed();

                            if(bWriteAlpha)
                            {
                                if(pAccAlpha)
                                {
                                    *pTmp++ = (sal_uInt8)0xff - (sal_uInt8)pAccAlpha->GetPixelIndex( nY, nX );
                                }
                                else
                                {
                                    *pTmp++ = (sal_uInt8)0xff;
                                }
                            }
						}

						rOStm.Write( pBuf, nAlignedWidth );
					}
				}
				break;
			}

			delete[] pBuf;
		}
	}

	rImageSize = rOStm.Tell() - rImageSize;

	return (!rOStm.GetError());
}

bool ImplWriteDIBBody(const Bitmap& rBitmap, SvStream& rOStm, BitmapReadAccess& rAcc, BitmapReadAccess* pAccAlpha, bool bCompressed)
{
	const MapMode aMapPixel(MAP_PIXEL);
	DIBV5Header aHeader;
	sal_uLong nImageSizePos(0);
	sal_uLong nEndPos(0);
	sal_uInt32 nCompression(COMPRESS_NONE);
	bool bRet(false);

	aHeader.nSize = pAccAlpha ? DIBV5HEADERSIZE : DIBINFOHEADERSIZE; // size dependent on CF_DIB type to use
	aHeader.nWidth = rAcc.Width();
	aHeader.nHeight = rAcc.Height();
	aHeader.nPlanes = 1;

    if(!pAccAlpha && isBitfieldCompression(rAcc.GetScanlineFormat()))
	{
        aHeader.nBitCount = (BMP_FORMAT_16BIT_TC_LSB_MASK == rAcc.GetScanlineFormat()) ? 16 : 32;
        aHeader.nSizeImage = rAcc.Height() * rAcc.GetScanlineSize();
        nCompression = BITFIELDS;
    }
    else
    {
        // #i5xxx# Limit bitcount to 24bit, the 32 bit cases are
        // not handled properly below (would have to set color
        // masks, and nCompression=BITFIELDS - but color mask is
        // not set for formats != *_TC_*). Note that this very
        // problem might cause trouble at other places - the
        // introduction of 32 bit RGBA bitmaps is relatively
        // recent.
        // #i59239# discretize bitcount to 1,4,8,24 (other cases
        // are not written below)
        const sal_uInt16 nBitCount(pAccAlpha ? 32 : discretizeBitcount(static_cast< sal_uInt16 >(rAcc.GetBitCount())));
        aHeader.nBitCount = nBitCount;
        aHeader.nSizeImage = rAcc.Height() * AlignedWidth4Bytes(rAcc.Width() * aHeader.nBitCount);

        if(bCompressed)
        {
            if(4 == nBitCount)
            {
                nCompression = RLE_4;
            }
            else if(8 == nBitCount)
            {
                nCompression = RLE_8;
            }
        }
	}

	if((rOStm.GetCompressMode() & COMPRESSMODE_ZBITMAP) && (rOStm.GetVersion() >= SOFFICE_FILEFORMAT_40))
	{
		aHeader.nCompression = ZCOMPRESS;
	}
	else
    {
		aHeader.nCompression = nCompression;
    }

	if(rBitmap.GetPrefSize().Width() && rBitmap.GetPrefSize().Height() && (rBitmap.GetPrefMapMode() != aMapPixel))
	{
        // #i48108# Try to recover xpels/ypels as previously stored on
        // disk. The problem with just converting maPrefSize to 100th
        // mm and then relating that to the bitmap pixel size is that
        // MapMode is integer-based, and suffers from roundoffs,
        // especially if maPrefSize is small. Trying to circumvent
        // that by performing part of the math in floating point.
        const Size aScale100000(OutputDevice::LogicToLogic(Size(100000L, 100000L), MAP_100TH_MM, rBitmap.GetPrefMapMode()));
        const double fBmpWidthM((double)rBitmap.GetPrefSize().Width() / aScale100000.Width());
        const double fBmpHeightM((double)rBitmap.GetPrefSize().Height() / aScale100000.Height());

        if(!basegfx::fTools::equalZero(fBmpWidthM) && !basegfx::fTools::equalZero(fBmpHeightM))
        {
            aHeader.nXPelsPerMeter = basegfx::fround(rAcc.Width() / fabs(fBmpWidthM));
            aHeader.nYPelsPerMeter = basegfx::fround(rAcc.Height() / fabs(fBmpHeightM));
        }
	}

	aHeader.nColsUsed = ((!pAccAlpha && aHeader.nBitCount <= 8) ? rAcc.GetPaletteEntryCount() : 0);
	aHeader.nColsImportant = 0;

	rOStm << aHeader.nSize;
	rOStm << aHeader.nWidth;
	rOStm << aHeader.nHeight;
	rOStm << aHeader.nPlanes;
	rOStm << aHeader.nBitCount;
	rOStm << aHeader.nCompression;

    nImageSizePos = rOStm.Tell();
	rOStm.SeekRel( sizeof( aHeader.nSizeImage ) );

    rOStm << aHeader.nXPelsPerMeter;
	rOStm << aHeader.nYPelsPerMeter;
	rOStm << aHeader.nColsUsed;
	rOStm << aHeader.nColsImportant;

    if(pAccAlpha) // only write DIBV5 when asked to do so
    {
        aHeader.nV5CSType = 0x57696E20; // LCS_WINDOWS_COLOR_SPACE
        aHeader.nV5Intent = 0x00000004; // LCS_GM_IMAGES

        rOStm << aHeader.nV5RedMask;
        rOStm << aHeader.nV5GreenMask;
        rOStm << aHeader.nV5BlueMask;
        rOStm << aHeader.nV5AlphaMask;
        rOStm << aHeader.nV5CSType;

        rOStm << aHeader.aV5Endpoints.aXyzRed.aXyzX;
        rOStm << aHeader.aV5Endpoints.aXyzRed.aXyzY;
        rOStm << aHeader.aV5Endpoints.aXyzRed.aXyzZ;
        rOStm << aHeader.aV5Endpoints.aXyzGreen.aXyzX;
        rOStm << aHeader.aV5Endpoints.aXyzGreen.aXyzY;
        rOStm << aHeader.aV5Endpoints.aXyzGreen.aXyzZ;
        rOStm << aHeader.aV5Endpoints.aXyzBlue.aXyzX;
        rOStm << aHeader.aV5Endpoints.aXyzBlue.aXyzY;
        rOStm << aHeader.aV5Endpoints.aXyzBlue.aXyzZ;

        rOStm << aHeader.nV5GammaRed;
        rOStm << aHeader.nV5GammaGreen;
        rOStm << aHeader.nV5GammaBlue;
        rOStm << aHeader.nV5Intent;
        rOStm << aHeader.nV5ProfileData;
        rOStm << aHeader.nV5ProfileSize;
        rOStm << aHeader.nV5Reserved;
    }

	if(ZCOMPRESS == aHeader.nCompression)
	{
		ZCodec aCodec;
		SvMemoryStream aMemStm(aHeader.nSizeImage + 4096, 65535);
		sal_uLong nCodedPos(rOStm.Tell());
        sal_uLong nLastPos(0);
		sal_uInt32 nCodedSize(0);
        sal_uInt32 nUncodedSize(0);

		// write uncoded data palette
		if(aHeader.nColsUsed)
        {
			ImplWriteDIBPalette(aMemStm, rAcc);
        }

		// write uncoded bits
		bRet = ImplWriteDIBBits(aMemStm, rAcc, pAccAlpha, nCompression, aHeader.nSizeImage);

		// get uncoded size
		nUncodedSize = aMemStm.Tell();

		// seek over compress info
		rOStm.SeekRel(12);

		// write compressed data
		aCodec.BeginCompression(3);
		aCodec.Write(rOStm, (sal_uInt8*)aMemStm.GetData(), nUncodedSize);
		aCodec.EndCompression();

		// update compress info ( coded size, uncoded size, uncoded compression )
        nLastPos = rOStm.Tell();
		nCodedSize = nLastPos - nCodedPos - 12;
		rOStm.Seek(nCodedPos);
		rOStm << nCodedSize << nUncodedSize << nCompression;
		rOStm.Seek(nLastPos);

		if(bRet)
        {
			bRet = (ERRCODE_NONE == rOStm.GetError());
        }
	}
	else
	{
		if(aHeader.nColsUsed)
        {
			ImplWriteDIBPalette(rOStm, rAcc);
        }

		bRet = ImplWriteDIBBits(rOStm, rAcc, pAccAlpha, aHeader.nCompression, aHeader.nSizeImage);
	}

	nEndPos = rOStm.Tell();
	rOStm.Seek(nImageSizePos);
	rOStm << aHeader.nSizeImage;
	rOStm.Seek(nEndPos);

	return bRet;
}

bool ImplWriteDIBFileHeader(SvStream& rOStm, BitmapReadAccess& rAcc, bool bUseDIBV5)
{
	const sal_uInt32 nPalCount((rAcc.HasPalette() ? rAcc.GetPaletteEntryCount() : isBitfieldCompression(rAcc.GetScanlineFormat()) ? 3UL : 0UL));
	const sal_uInt32 nOffset(14 + (bUseDIBV5 ? DIBV5HEADERSIZE : DIBINFOHEADERSIZE) + nPalCount * 4UL);

	rOStm << (sal_uInt16)0x4D42; // 'MB' from BITMAPFILEHEADER
	rOStm << (sal_uInt32)(nOffset + (rAcc.Height() * rAcc.GetScanlineSize()));
	rOStm << (sal_uInt16)0;
	rOStm << (sal_uInt16)0;
	rOStm << nOffset;

	return( rOStm.GetError() == 0UL );
}

//////////////////////////////////////////////////////////////////////////////

bool ImplReadDIB(
    Bitmap& rTarget, Bitmap*
    pTargetAlpha,
    SvStream& rIStm,
    bool bFileHeader)
{
    const sal_uInt16 nOldFormat(rIStm.GetNumberFormatInt());
    const sal_uLong nOldPos(rIStm.Tell());
    sal_uLong nOffset(0UL);
    bool bRet(false);

    rIStm.SetNumberFormatInt(NUMBERFORMAT_INT_LITTLEENDIAN);

    if(bFileHeader)
    {
        if(ImplReadDIBFileHeader(rIStm, nOffset))
        {
            bRet = ImplReadDIBBody(rIStm, rTarget, nOffset >= DIBV5HEADERSIZE ? pTargetAlpha : 0, nOffset);
        }
    }
    else
    {
        bRet = ImplReadDIBBody(rIStm, rTarget, 0, nOffset);
    }

    if(!bRet)
    {
        if(!rIStm.GetError())
        {
            rIStm.SetError(SVSTREAM_GENERALERROR);
        }

        rIStm.Seek(nOldPos);
    }

    rIStm.SetNumberFormatInt(nOldFormat);

    return bRet;
}

bool ImplWriteDIB(
    const Bitmap& rSource,
    const Bitmap* pSourceAlpha,
    SvStream& rOStm,
    bool bCompressed,
    bool bFileHeader)
{
    const Size aSizePix(rSource.GetSizePixel());
    bool bRet(false);

    if(aSizePix.Width() && aSizePix.Height())
    {
        BitmapReadAccess* pAcc = const_cast< Bitmap& >(rSource).AcquireReadAccess();
        BitmapReadAccess* pAccAlpha = 0;
        const sal_uInt16 nOldFormat(rOStm.GetNumberFormatInt());
        const sal_uLong nOldPos(rOStm.Tell());

        if(pSourceAlpha)
        {
            const Size aSizePixAlpha(pSourceAlpha->GetSizePixel());

            if(aSizePixAlpha == aSizePix)
            {
                pAccAlpha = const_cast< Bitmap* >(pSourceAlpha)->AcquireReadAccess();
            }
            else
            {
                OSL_ENSURE(false, "WriteDIB got an alpha channel, but it's pixel size differs from the base bitmap (!)");
            }
        }

        rOStm.SetNumberFormatInt(NUMBERFORMAT_INT_LITTLEENDIAN);

        if(pAcc)
        {
            if(bFileHeader)
            {
                if(ImplWriteDIBFileHeader(rOStm, *pAcc, 0 != pSourceAlpha))
                {
                    bRet = ImplWriteDIBBody(rSource, rOStm, *pAcc, pAccAlpha, bCompressed);
                }
            }
            else
            {
                bRet = ImplWriteDIBBody(rSource, rOStm, *pAcc, pAccAlpha, bCompressed);
            }

            const_cast< Bitmap& >(rSource).ReleaseAccess(pAcc);

            if(pAccAlpha)
            {
                const_cast< Bitmap* >(pSourceAlpha)->ReleaseAccess(pAccAlpha);
            }
        }

        if(!bRet)
        {
            rOStm.SetError(SVSTREAM_GENERALERROR);
            rOStm.Seek(nOldPos);
        }

        rOStm.SetNumberFormatInt(nOldFormat);
    }

    return bRet;
}

//////////////////////////////////////////////////////////////////////////////

bool ReadDIB(
    Bitmap& rTarget,
    SvStream& rIStm,
    bool bFileHeader)
{
    return ImplReadDIB(rTarget, 0, rIStm, bFileHeader);
}

bool ReadDIBBitmapEx(
    BitmapEx& rTarget,
    SvStream& rIStm)
{
    Bitmap aBmp;
    bool bRetval(ImplReadDIB(aBmp, 0, rIStm, true) && !rIStm.GetError());

    if(bRetval)
    {
        // base bitmap was read, set as return value and try to read alpha extra-data
        const sal_uLong nStmPos(rIStm.Tell());
        sal_uInt32 nMagic1(0);
        sal_uInt32 nMagic2(0);

        rTarget = BitmapEx(aBmp);
        rIStm >> nMagic1 >> nMagic2;
        bRetval = (0x25091962 == nMagic1) && (0xACB20201 == nMagic2) && !rIStm.GetError();

        if(bRetval)
        {
            sal_uInt8 bTransparent(false);

            rIStm >> bTransparent;
            bRetval = !rIStm.GetError();

            if(bRetval)
            {
                if((sal_uInt8)TRANSPARENT_BITMAP == bTransparent)
                {
                    Bitmap aMask;

                    bRetval = ImplReadDIB(aMask, 0, rIStm, true);

                    if(bRetval)
                    {
                        if(!!aMask)
                        {
                            // do we have an alpha mask?
                            if((8 == aMask.GetBitCount()) && aMask.HasGreyPalette())
                            {
                                AlphaMask aAlpha;

                                // create alpha mask quickly (without greyscale conversion)
                                aAlpha.ImplSetBitmap(aMask);
                                rTarget = BitmapEx(aBmp, aAlpha);
                            }
                            else
                            {
                                rTarget = BitmapEx(aBmp, aMask);
                            }
                        }
                    }
                }
                else if((sal_uInt8)TRANSPARENT_COLOR == bTransparent)
                {
                    Color aTransparentColor;

                    rIStm >> aTransparentColor;
                    bRetval = !rIStm.GetError();

                    if(bRetval)
                    {
                        rTarget = BitmapEx(aBmp, aTransparentColor);
                    }
                }
            }
        }

        if(!bRetval)
        {
            // alpha extra data could not be read; reset, but use base bitmap as result
            rIStm.ResetError();
            rIStm.Seek(nStmPos);
            bRetval = true;
        }
    }

    return bRetval;
}

bool ReadDIBV5(
    Bitmap& rTarget,
    Bitmap& rTargetAlpha,
    SvStream& rIStm)
{
    return ImplReadDIB(rTarget, &rTargetAlpha, rIStm, true);
}

//////////////////////////////////////////////////////////////////////////////

bool WriteDIB(
    const Bitmap& rSource,
    SvStream& rOStm,
    bool bCompressed,
    bool bFileHeader)
{
    return ImplWriteDIB(rSource, 0, rOStm, bCompressed, bFileHeader);
}

bool WriteDIBBitmapEx(
    const BitmapEx& rSource,
    SvStream& rOStm)
{
    if(ImplWriteDIB(rSource.GetBitmap(), 0, rOStm, true, true))
    {
        rOStm << (sal_uInt32)0x25091962;
        rOStm << (sal_uInt32)0xACB20201;
        rOStm << (sal_uInt8)rSource.eTransparent;

        if(TRANSPARENT_BITMAP == rSource.eTransparent)
        {
            return ImplWriteDIB(rSource.aMask, 0, rOStm, true, true);
        }
        else if(TRANSPARENT_COLOR == rSource.eTransparent)
        {
            rOStm << rSource.aTransparentColor;
            return true;
        }
    }

    return false;
}

bool WriteDIBV5(
    const Bitmap& rSource,
    const Bitmap& rSourceAlpha,
    SvStream& rOStm)
{
    return ImplWriteDIB(rSource, &rSourceAlpha, rOStm, false, true);
}

//////////////////////////////////////////////////////////////////////////////
// eof