Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1873 insertions, 0 deletions

diff --git a/vcl/source/bitmap/dibtools.cxx b/vcl/source/bitmap/dibtools.cxx
new file mode 100644
index 000000000..96b82b9a7
--- /dev/null
+++ b/vcl/source/bitmap/dibtools.cxx
@@ -0,0 +1,1873 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   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 .
+ */
+
+#include <sal/config.h>
+#include <sal/log.hxx>
+
+#include <cassert>
+
+#include <o3tl/safeint.hxx>
+#include <vcl/dibtools.hxx>
+#include <comphelper/fileformat.h>
+#include <tools/zcodec.hxx>
+#include <tools/stream.hxx>
+#include <tools/fract.hxx>
+#include <tools/helpers.hxx>
+#include <tools/GenericTypeSerializer.hxx>
+#include <unotools/configmgr.hxx>
+#include <vcl/bitmapex.hxx>
+#include <vcl/outdev.hxx>
+#include <bitmap/BitmapWriteAccess.hxx>
+#include <memory>
+
+#define DIBCOREHEADERSIZE       ( 12UL )
+#define DIBINFOHEADERSIZE       ( sizeof(DIBInfoHeader) )
+#define DIBV5HEADERSIZE         ( sizeof(DIBV5Header) )
+
+// - DIBInfoHeader and DIBV5Header
+
+typedef sal_Int32 FXPT2DOT30;
+
+namespace
+{
+
+struct CIEXYZ
+{
+    FXPT2DOT30      aXyzX;
+    FXPT2DOT30      aXyzY;
+    FXPT2DOT30      aXyzZ;
+
+    CIEXYZ()
+    :   aXyzX(0),
+        aXyzY(0),
+        aXyzZ(0)
+    {}
+};
+
+struct CIEXYZTriple
+{
+    CIEXYZ          aXyzRed;
+    CIEXYZ          aXyzGreen;
+    CIEXYZ          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(0),
+        nWidth(0),
+        nHeight(0),
+        nPlanes(0),
+        nBitCount(0),
+        nCompression(0),
+        nSizeImage(0),
+        nXPelsPerMeter(0),
+        nYPelsPerMeter(0),
+        nColsUsed(0),
+        nColsImportant(0)
+    {}
+};
+
+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()
+    :   nV5RedMask(0),
+        nV5GreenMask(0),
+        nV5BlueMask(0),
+        nV5AlphaMask(0),
+        nV5CSType(0),
+        nV5GammaRed(0),
+        nV5GammaGreen(0),
+        nV5GammaBlue(0),
+        nV5Intent(0),
+        nV5ProfileData(0),
+        nV5ProfileSize(0),
+        nV5Reserved(0)
+    {}
+};
+
+vcl::PixelFormat convertToBPP(sal_uInt16 nCount)
+{
+    return (nCount <= 1) ? vcl::PixelFormat::N1_BPP :
+           (nCount <= 8) ? vcl::PixelFormat::N8_BPP :
+                           vcl::PixelFormat::N24_BPP;
+}
+
+bool isBitfieldCompression( ScanlineFormat nScanlineFormat )
+{
+    return ScanlineFormat::N32BitTcMask == nScanlineFormat;
+}
+
+bool ImplReadDIBInfoHeader(SvStream& rIStm, DIBV5Header& rHeader, bool& bTopDown, bool bMSOFormat)
+{
+    if (rIStm.remainingSize() <= 4)
+        return false;
+    // BITMAPINFOHEADER or BITMAPCOREHEADER or BITMAPV5HEADER
+    sal_uInt64 const aStartPos(rIStm.Tell());
+    rIStm.ReadUInt32( rHeader.nSize );
+
+    // BITMAPCOREHEADER
+    if ( rHeader.nSize == DIBCOREHEADERSIZE )
+    {
+        sal_Int16 nTmp16;
+
+        rIStm.ReadInt16( nTmp16 ); rHeader.nWidth = nTmp16;
+        rIStm.ReadInt16( nTmp16 ); rHeader.nHeight = nTmp16;
+        rIStm.ReadUInt16( rHeader.nPlanes );
+        rIStm.ReadUInt16( rHeader.nBitCount );
+    }
+    else if ( bMSOFormat && rHeader.nSize == DIBINFOHEADERSIZE )
+    {
+        sal_Int16 nTmp16(0);
+        rIStm.ReadInt16(nTmp16);
+        rHeader.nWidth = nTmp16;
+        rIStm.ReadInt16(nTmp16);
+        rHeader.nHeight = nTmp16;
+        sal_uInt8 nTmp8(0);
+        rIStm.ReadUChar(nTmp8);
+        rHeader.nPlanes = nTmp8;
+        rIStm.ReadUChar(nTmp8);
+        rHeader.nBitCount = nTmp8;
+        rIStm.ReadInt16(nTmp16);
+        rHeader.nSizeImage = nTmp16;
+        rIStm.ReadInt16(nTmp16);
+        rHeader.nCompression = nTmp16;
+        if ( !rHeader.nSizeImage ) // uncompressed?
+            rHeader.nSizeImage = ((rHeader.nWidth * rHeader.nBitCount + 31) & ~31) / 8 * rHeader.nHeight;
+        rIStm.ReadInt32( rHeader.nXPelsPerMeter );
+        rIStm.ReadInt32( rHeader.nYPelsPerMeter );
+        rIStm.ReadUInt32( rHeader.nColsUsed );
+        rIStm.ReadUInt32( rHeader.nColsImportant );
+    }
+    else
+    {
+        // BITMAPCOREHEADER, BITMAPV5HEADER or unknown. Read as far as possible
+        std::size_t nUsed(sizeof(rHeader.nSize));
+
+        auto readUInt16 = [&nUsed, &rHeader, &rIStm](sal_uInt16 & v) {
+            if (nUsed < rHeader.nSize) {
+                rIStm.ReadUInt16(v);
+                nUsed += sizeof(v);
+            }
+        };
+        auto readInt32 = [&nUsed, &rHeader, &rIStm](sal_Int32 & v) {
+            if (nUsed < rHeader.nSize) {
+                rIStm.ReadInt32(v);
+                nUsed += sizeof(v);
+            }
+        };
+        auto readUInt32 = [&nUsed, &rHeader, &rIStm](sal_uInt32 & v) {
+            if (nUsed < rHeader.nSize) {
+                rIStm.ReadUInt32(v);
+                nUsed += sizeof(v);
+            }
+        };
+
+        // read DIBInfoHeader entries
+        readInt32( rHeader.nWidth );
+        readInt32( rHeader.nHeight );
+        readUInt16( rHeader.nPlanes );
+        readUInt16( rHeader.nBitCount );
+        readUInt32( rHeader.nCompression );
+        readUInt32( rHeader.nSizeImage );
+        readInt32( rHeader.nXPelsPerMeter );
+        readInt32( rHeader.nYPelsPerMeter );
+        readUInt32( rHeader.nColsUsed );
+        readUInt32( rHeader.nColsImportant );
+
+        // read DIBV5HEADER members
+        readUInt32( rHeader.nV5RedMask );
+        readUInt32( rHeader.nV5GreenMask );
+        readUInt32( rHeader.nV5BlueMask );
+        readUInt32( rHeader.nV5AlphaMask );
+        readUInt32( rHeader.nV5CSType );
+
+        // read contained CIEXYZTriple's
+        readInt32( rHeader.aV5Endpoints.aXyzRed.aXyzX );
+        readInt32( rHeader.aV5Endpoints.aXyzRed.aXyzY );
+        readInt32( rHeader.aV5Endpoints.aXyzRed.aXyzZ );
+        readInt32( rHeader.aV5Endpoints.aXyzGreen.aXyzX );
+        readInt32( rHeader.aV5Endpoints.aXyzGreen.aXyzY );
+        readInt32( rHeader.aV5Endpoints.aXyzGreen.aXyzZ );
+        readInt32( rHeader.aV5Endpoints.aXyzBlue.aXyzX );
+        readInt32( rHeader.aV5Endpoints.aXyzBlue.aXyzY );
+        readInt32( rHeader.aV5Endpoints.aXyzBlue.aXyzZ );
+
+        readUInt32( rHeader.nV5GammaRed );
+        readUInt32( rHeader.nV5GammaGreen );
+        readUInt32( rHeader.nV5GammaBlue );
+        readUInt32( rHeader.nV5Intent );
+        readUInt32( rHeader.nV5ProfileData );
+        readUInt32( rHeader.nV5ProfileSize );
+        readUInt32( rHeader.nV5Reserved );
+
+        // Read color mask. An additional 12 bytes of color bitfields follow the info header (WinBMPv3-NT)
+        sal_uInt32 nColorMask = 0;
+        if (BITFIELDS == rHeader.nCompression && DIBINFOHEADERSIZE == rHeader.nSize)
+        {
+            rIStm.ReadUInt32( rHeader.nV5RedMask );
+            rIStm.ReadUInt32( rHeader.nV5GreenMask );
+            rIStm.ReadUInt32( rHeader.nV5BlueMask );
+            nColorMask = 12;
+        }
+
+        // seek to EndPos
+        if (!checkSeek(rIStm, aStartPos + rHeader.nSize + nColorMask))
+            return false;
+    }
+
+    if (!rIStm.good() || rHeader.nHeight == SAL_MIN_INT32)
+        return false;
+
+    if ( rHeader.nHeight < 0 )
+    {
+        bTopDown = true;
+        rHeader.nHeight *= -1;
+    }
+    else
+    {
+        bTopDown = false;
+    }
+
+    if ( rHeader.nWidth < 0 || rHeader.nXPelsPerMeter < 0 || rHeader.nYPelsPerMeter < 0 )
+    {
+        rIStm.SetError( SVSTREAM_FILEFORMAT_ERROR );
+    }
+
+    // #144105# protect a little against damaged files
+    assert(rHeader.nHeight >= 0);
+    if (rHeader.nHeight != 0 && rHeader.nWidth >= 0
+        && (rHeader.nSizeImage / 16 / static_cast<sal_uInt32>(rHeader.nHeight)
+            > o3tl::make_unsigned(rHeader.nWidth)))
+    {
+        rHeader.nSizeImage = 0;
+    }
+
+
+    if (rHeader.nPlanes != 1)
+        return false;
+
+    if (rHeader.nBitCount != 0 && rHeader.nBitCount != 1 &&
+        rHeader.nBitCount != 4 && rHeader.nBitCount != 8 &&
+        rHeader.nBitCount != 16 && rHeader.nBitCount != 24 &&
+        rHeader.nBitCount != 32)
+    {
+        return false;
+    }
+
+    return rIStm.good();
+}
+
+bool ImplReadDIBPalette(SvStream& rIStm, BitmapPalette& rPal, bool bQuad)
+{
+    const sal_uInt16    nColors = rPal.GetEntryCount();
+    const sal_uLong     nPalSize = nColors * ( bQuad ? 4UL : 3UL );
+    BitmapColor     aPalColor;
+
+    std::unique_ptr<sal_uInt8[]> pEntries(new sal_uInt8[ nPalSize ]);
+    if (rIStm.ReadBytes(pEntries.get(), nPalSize) != nPalSize)
+    {
+        return false;
+    }
+
+    sal_uInt8* pTmpEntry = pEntries.get();
+    for( sal_uInt16 i = 0; i < nColors; i++ )
+    {
+        aPalColor.SetBlue( *pTmpEntry++ );
+        aPalColor.SetGreen( *pTmpEntry++ );
+        aPalColor.SetRed( *pTmpEntry++ );
+
+        if( bQuad )
+            pTmpEntry++;
+
+        rPal[i] = aPalColor;
+    }
+
+    return rIStm.GetError() == ERRCODE_NONE;
+}
+
+BitmapColor SanitizePaletteIndex(sal_uInt8 nIndex, BitmapPalette& rPalette, bool bForceToMonoWhileReading)
+{
+    const sal_uInt16 nPaletteEntryCount = rPalette.GetEntryCount();
+    if (nPaletteEntryCount && nIndex >= nPaletteEntryCount)
+    {
+        auto nSanitizedIndex = nIndex % nPaletteEntryCount;
+        SAL_WARN_IF(nIndex != nSanitizedIndex, "vcl", "invalid colormap index: "
+                    << static_cast<unsigned int>(nIndex) << ", colormap len is: "
+                    << nPaletteEntryCount);
+        nIndex = nSanitizedIndex;
+    }
+
+    if (nPaletteEntryCount && bForceToMonoWhileReading)
+    {
+        return BitmapColor(static_cast<sal_uInt8>(rPalette[nIndex].GetLuminance() >= 255));
+    }
+
+    return BitmapColor(nIndex);
+}
+
+BitmapColor SanitizeColor(const BitmapColor &rColor, bool bForceToMonoWhileReading)
+{
+    if (!bForceToMonoWhileReading)
+        return rColor;
+    return BitmapColor(static_cast<sal_uInt8>(rColor.GetLuminance() >= 255));
+}
+
+bool ImplDecodeRLE(sal_uInt8* pBuffer, DIBV5Header const & rHeader, BitmapWriteAccess& rAcc, BitmapPalette& rPalette, bool bForceToMonoWhileReading, bool bRLE4)
+{
+    Scanline pRLE = pBuffer;
+    Scanline pEndRLE = pBuffer + rHeader.nSizeImage;
+    tools::Long        nY = rHeader.nHeight - 1;
+    const sal_uLong nWidth = rAcc.Width();
+    sal_uLong       nCountByte;
+    sal_uLong       nRunByte;
+    sal_uLong       nX = 0;
+    sal_uInt8       cTmp;
+    bool        bEndDecoding = false;
+
+    do
+    {
+        if (pRLE == pEndRLE)
+            return false;
+        if( ( nCountByte = *pRLE++ ) == 0 )
+        {
+            if (pRLE == pEndRLE)
+                return false;
+            nRunByte = *pRLE++;
+
+            if( nRunByte > 2 )
+            {
+                Scanline pScanline = rAcc.GetScanline(nY);
+                if( bRLE4 )
+                {
+                    nCountByte = nRunByte >> 1;
+
+                    for( sal_uLong i = 0; i < nCountByte; i++ )
+                    {
+                        if (pRLE == pEndRLE)
+                            return false;
+
+                        cTmp = *pRLE++;
+
+                        if( nX < nWidth )
+                            rAcc.SetPixelOnData(pScanline, nX++, SanitizePaletteIndex(cTmp >> 4, rPalette, bForceToMonoWhileReading));
+
+                        if( nX < nWidth )
+                            rAcc.SetPixelOnData(pScanline, nX++, SanitizePaletteIndex(cTmp & 0x0f, rPalette, bForceToMonoWhileReading));
+                    }
+
+                    if( nRunByte & 1 )
+                    {
+                        if (pRLE == pEndRLE)
+                            return false;
+
+                        if( nX < nWidth )
+                            rAcc.SetPixelOnData(pScanline, nX++, SanitizePaletteIndex(*pRLE >> 4, rPalette, bForceToMonoWhileReading));
+
+                        pRLE++;
+                    }
+
+                    if( ( ( nRunByte + 1 ) >> 1 ) & 1 )
+                    {
+                        if (pRLE == pEndRLE)
+                            return false;
+
+                        pRLE++;
+                    }
+                }
+                else
+                {
+                    for( sal_uLong i = 0; i < nRunByte; i++ )
+                    {
+                        if (pRLE == pEndRLE)
+                            return false;
+
+                        if( nX < nWidth )
+                            rAcc.SetPixelOnData(pScanline, nX++, SanitizePaletteIndex(*pRLE, rPalette, bForceToMonoWhileReading));
+
+                        pRLE++;
+                    }
+
+                    if( nRunByte & 1 )
+                    {
+                        if (pRLE == pEndRLE)
+                            return false;
+
+                        pRLE++;
+                    }
+                }
+            }
+            else if( !nRunByte )
+            {
+                nY--;
+                nX = 0;
+            }
+            else if( nRunByte == 1 )
+                bEndDecoding = true;
+            else
+            {
+                if (pRLE == pEndRLE)
+                    return false;
+
+                nX += *pRLE++;
+
+                if (pRLE == pEndRLE)
+                    return false;
+
+                nY -= *pRLE++;
+            }
+        }
+        else
+        {
+            if (pRLE == pEndRLE)
+                return false;
+            cTmp = *pRLE++;
+
+            Scanline pScanline = rAcc.GetScanline(nY);
+            if( bRLE4 )
+            {
+                nRunByte = nCountByte >> 1;
+
+                for (sal_uLong i = 0; i < nRunByte && nX < nWidth; ++i)
+                {
+                    rAcc.SetPixelOnData(pScanline, nX++, SanitizePaletteIndex(cTmp >> 4, rPalette, bForceToMonoWhileReading));
+                    if( nX < nWidth )
+                        rAcc.SetPixelOnData(pScanline, nX++, SanitizePaletteIndex(cTmp & 0x0f, rPalette, bForceToMonoWhileReading));
+                }
+
+                if( ( nCountByte & 1 ) && ( nX < nWidth ) )
+                    rAcc.SetPixelOnData(pScanline, nX++, SanitizePaletteIndex(cTmp >> 4, rPalette, bForceToMonoWhileReading));
+            }
+            else
+            {
+                for (sal_uLong i = 0; i < nCountByte && nX < nWidth; ++i)
+                    rAcc.SetPixelOnData(pScanline, nX++, SanitizePaletteIndex(cTmp, rPalette, bForceToMonoWhileReading));
+            }
+        }
+    }
+    while (!bEndDecoding && (nY >= 0));
+
+    return true;
+}
+
+bool ImplReadDIBBits(SvStream& rIStm, DIBV5Header& rHeader, BitmapWriteAccess& rAcc, BitmapPalette& rPalette, BitmapWriteAccess* pAccAlpha,
+                     bool bTopDown, bool& rAlphaUsed, const sal_uInt64 nAlignedWidth,
+                     const bool bForceToMonoWhileReading)
+{
+    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 ScanlineFormat::N1BitMsbPal:
+        case ScanlineFormat::N24BitTcBgr:
+        {
+            // we can't trust arbitrary-sourced index based formats to have correct indexes, so we exclude the pal formats
+            // from raw read and force checking their colormap indexes
+            bNative = ( ( rAcc.IsBottomUp() != bTopDown ) && !bRLE && !bTCMask && ( rAcc.GetScanlineSize() == nAlignedWidth ) );
+            break;
+        }
+
+        default:
+        {
+            break;
+        }
+    }
+
+    // Read data
+    if (bNative)
+    {
+        if (nAlignedWidth
+            > std::numeric_limits<std::size_t>::max() / rHeader.nHeight)
+        {
+            return false;
+        }
+        std::size_t n = nAlignedWidth * rHeader.nHeight;
+        if (rIStm.ReadBytes(rAcc.GetBuffer(), n) != n)
+        {
+            return false;
+        }
+    }
+    else
+    {
+        if (rHeader.nV5RedMask > 0)
+            nRMask = rHeader.nV5RedMask;
+        if (rHeader.nV5GreenMask > 0)
+            nGMask = rHeader.nV5GreenMask;
+        if (rHeader.nV5BlueMask > 0)
+            nBMask = rHeader.nV5BlueMask;
+
+        const tools::Long nWidth(rHeader.nWidth);
+        const tools::Long nHeight(rHeader.nHeight);
+        tools::Long nResult = 0;
+        if (utl::ConfigManager::IsFuzzing() && (o3tl::checked_multiply(nWidth, nHeight, nResult) || nResult > 4000000))
+            return false;
+
+        if (bRLE)
+        {
+            if(!rHeader.nSizeImage)
+            {
+                rHeader.nSizeImage = rIStm.remainingSize();
+            }
+
+            if (rHeader.nSizeImage > rIStm.remainingSize())
+                return false;
+            std::vector<sal_uInt8> aBuffer(rHeader.nSizeImage);
+            if (rIStm.ReadBytes(aBuffer.data(), rHeader.nSizeImage) != rHeader.nSizeImage)
+                return false;
+            if (!ImplDecodeRLE(aBuffer.data(), rHeader, rAcc, rPalette, bForceToMonoWhileReading, RLE_4 == rHeader.nCompression))
+                return false;
+        }
+        else
+        {
+            if (nAlignedWidth > rIStm.remainingSize())
+            {
+                // ofz#11188 avoid timeout
+                // all following paths will enter a case statement, and nCount
+                // is always at least 1, so we can check here before allocation
+                // if at least one row can be read
+                return false;
+            }
+            std::vector<sal_uInt8> aBuf(nAlignedWidth);
+
+            const tools::Long nI(bTopDown ? 1 : -1);
+            tools::Long nY(bTopDown ? 0 : nHeight - 1);
+            tools::Long nCount(nHeight);
+
+            switch(rHeader.nBitCount)
+            {
+                case 1:
+                {
+                    for( ; nCount--; nY += nI )
+                    {
+                        sal_uInt8 * pTmp = aBuf.data();
+                        if (rIStm.ReadBytes(pTmp, nAlignedWidth)
+                            != nAlignedWidth)
+                        {
+                            return false;
+                        }
+                        sal_uInt8   cTmp = *pTmp++;
+                        Scanline pScanline = rAcc.GetScanline(nY);
+                        for( tools::Long nX = 0, nShift = 8; nX < nWidth; nX++ )
+                        {
+                            if( !nShift )
+                            {
+                                nShift = 8;
+                                cTmp = *pTmp++;
+                            }
+
+                            auto nIndex = (cTmp >> --nShift) & 1;
+                            rAcc.SetPixelOnData(pScanline, nX, SanitizePaletteIndex(nIndex, rPalette, bForceToMonoWhileReading));
+                        }
+                    }
+                }
+                break;
+
+                case 4:
+                {
+                    for( ; nCount--; nY += nI )
+                    {
+                        sal_uInt8 * pTmp = aBuf.data();
+                        if (rIStm.ReadBytes(pTmp, nAlignedWidth)
+                            != nAlignedWidth)
+                        {
+                            return false;
+                        }
+                        sal_uInt8   cTmp = *pTmp++;
+                        Scanline pScanline = rAcc.GetScanline(nY);
+                        for( tools::Long nX = 0, nShift = 2; nX < nWidth; nX++ )
+                        {
+                            if( !nShift )
+                            {
+                                nShift = 2;
+                                cTmp = *pTmp++;
+                            }
+
+                            auto nIndex = (cTmp >> ( --nShift << 2 ) ) & 0x0f;
+                            rAcc.SetPixelOnData(pScanline, nX, SanitizePaletteIndex(nIndex, rPalette, bForceToMonoWhileReading));
+                        }
+                    }
+                }
+                break;
+
+                case 8:
+                {
+                    for( ; nCount--; nY += nI )
+                    {
+                        sal_uInt8 * pTmp = aBuf.data();
+                        if (rIStm.ReadBytes(pTmp, nAlignedWidth)
+                            != nAlignedWidth)
+                        {
+                            return false;
+                        }
+
+                        Scanline pScanline = rAcc.GetScanline(nY);
+                        for( tools::Long nX = 0; nX < nWidth; nX++ )
+                        {
+                            auto nIndex = *pTmp++;
+                            rAcc.SetPixelOnData(pScanline, nX, SanitizePaletteIndex(nIndex, rPalette, bForceToMonoWhileReading));
+                        }
+                    }
+                }
+                break;
+
+                case 16:
+                {
+                    ColorMaskElement aRedMask(nRMask);
+                    if (!aRedMask.CalcMaskShift())
+                        return false;
+                    ColorMaskElement aGreenMask(nGMask);
+                    if (!aGreenMask.CalcMaskShift())
+                        return false;
+                    ColorMaskElement aBlueMask(nBMask);
+                    if (!aBlueMask.CalcMaskShift())
+                        return false;
+
+                    ColorMask   aMask(aRedMask, aGreenMask, aBlueMask);
+                    BitmapColor aColor;
+
+                    for( ; nCount--; nY += nI )
+                    {
+                        sal_uInt16 * pTmp16 = reinterpret_cast<sal_uInt16*>(aBuf.data());
+                        if (rIStm.ReadBytes(pTmp16, nAlignedWidth)
+                            != nAlignedWidth)
+                        {
+                            return false;
+                        }
+
+                        Scanline pScanline = rAcc.GetScanline(nY);
+                        for( tools::Long nX = 0; nX < nWidth; nX++ )
+                        {
+                            aMask.GetColorFor16BitLSB( aColor, reinterpret_cast<sal_uInt8*>(pTmp16++) );
+                            rAcc.SetPixelOnData(pScanline, nX, SanitizeColor(aColor, bForceToMonoWhileReading));
+                        }
+                    }
+                }
+                break;
+
+                case 24:
+                {
+                    BitmapColor aPixelColor;
+
+                    for( ; nCount--; nY += nI )
+                    {
+                        sal_uInt8* pTmp = aBuf.data();
+                        if (rIStm.ReadBytes(pTmp, nAlignedWidth)
+                            != nAlignedWidth)
+                        {
+                            return false;
+                        }
+
+                        Scanline pScanline = rAcc.GetScanline(nY);
+                        for( tools::Long nX = 0; nX < nWidth; nX++ )
+                        {
+                            aPixelColor.SetBlue( *pTmp++ );
+                            aPixelColor.SetGreen( *pTmp++ );
+                            aPixelColor.SetRed( *pTmp++ );
+                            rAcc.SetPixelOnData(pScanline, nX, SanitizeColor(aPixelColor, bForceToMonoWhileReading));
+                        }
+                    }
+                }
+                break;
+
+                case 32:
+                {
+                    ColorMaskElement aRedMask(nRMask);
+                    if (!aRedMask.CalcMaskShift())
+                        return false;
+                    ColorMaskElement aGreenMask(nGMask);
+                    if (!aGreenMask.CalcMaskShift())
+                        return false;
+                    ColorMaskElement aBlueMask(nBMask);
+                    if (!aBlueMask.CalcMaskShift())
+                        return false;
+                    ColorMask aMask(aRedMask, aGreenMask, aBlueMask);
+
+                    BitmapColor aColor;
+                    sal_uInt32* pTmp32;
+
+                    if(pAccAlpha)
+                    {
+                        sal_uInt8 aAlpha;
+
+                        for( ; nCount--; nY += nI )
+                        {
+                            pTmp32 = reinterpret_cast<sal_uInt32*>(aBuf.data());
+                            if (rIStm.ReadBytes(pTmp32, nAlignedWidth)
+                                != nAlignedWidth)
+                            {
+                                return false;
+                            }
+
+                            Scanline pScanline = rAcc.GetScanline(nY);
+                            Scanline pAlphaScanline = pAccAlpha->GetScanline(nY);
+                            for( tools::Long nX = 0; nX < nWidth; nX++ )
+                            {
+                                aMask.GetColorAndAlphaFor32Bit( aColor, aAlpha, reinterpret_cast<sal_uInt8*>(pTmp32++) );
+                                rAcc.SetPixelOnData(pScanline, nX, SanitizeColor(aColor, bForceToMonoWhileReading));
+                                pAccAlpha->SetPixelOnData(pAlphaScanline, nX, BitmapColor(sal_uInt8(0xff) - aAlpha));
+                                rAlphaUsed |= 0xff != aAlpha;
+                            }
+                        }
+                    }
+                    else
+                    {
+                        for( ; nCount--; nY += nI )
+                        {
+                            pTmp32 = reinterpret_cast<sal_uInt32*>(aBuf.data());
+                            if (rIStm.ReadBytes(pTmp32, nAlignedWidth)
+                                != nAlignedWidth)
+                            {
+                                return false;
+                            }
+
+                            Scanline pScanline = rAcc.GetScanline(nY);
+                            for( tools::Long nX = 0; nX < nWidth; nX++ )
+                            {
+                                aMask.GetColorFor32Bit( aColor, reinterpret_cast<sal_uInt8*>(pTmp32++) );
+                                rAcc.SetPixelOnData(pScanline, nX, SanitizeColor(aColor, bForceToMonoWhileReading));
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    return rIStm.GetError() == ERRCODE_NONE;
+}
+
+bool ImplReadDIBBody(SvStream& rIStm, Bitmap& rBmp, AlphaMask* pBmpAlpha, sal_uInt64 nOffset, bool bIsMask, bool bMSOFormat)
+{
+    DIBV5Header aHeader;
+    const sal_uInt64 nStmPos = rIStm.Tell();
+    bool bTopDown(false);
+
+    if (!ImplReadDIBInfoHeader(rIStm, aHeader, bTopDown, bMSOFormat))
+        return false;
+
+    //BI_BITCOUNT_0 jpeg/png is unsupported
+    if (aHeader.nBitCount == 0)
+        return false;
+
+    if (aHeader.nWidth <= 0 || aHeader.nHeight <= 0)
+        return false;
+
+    // In case ImplReadDIB() didn't call ImplReadDIBFileHeader() before
+    // this method, nOffset is 0, that's OK.
+    if (nOffset && aHeader.nSize > nOffset)
+    {
+        // Header size claims to extend into the image data.
+        // Looks like an error.
+        return false;
+    }
+
+    sal_uInt16 nColors(0);
+    SvStream* pIStm;
+    std::unique_ptr<SvMemoryStream> pMemStm;
+    std::vector<sal_uInt8> aData;
+
+    if (aHeader.nBitCount <= 8)
+    {
+        if(aHeader.nColsUsed)
+        {
+            nColors = static_cast<sal_uInt16>(aHeader.nColsUsed);
+        }
+        else
+        {
+            nColors = ( 1 << aHeader.nBitCount );
+        }
+    }
+
+    if (ZCOMPRESS == aHeader.nCompression)
+    {
+        sal_uInt32 nCodedSize(0);
+        sal_uInt32  nUncodedSize(0);
+
+        // read coding information
+        rIStm.ReadUInt32( nCodedSize ).ReadUInt32( nUncodedSize ).ReadUInt32( aHeader.nCompression );
+        if (nCodedSize > rIStm.remainingSize())
+           nCodedSize = sal_uInt32(rIStm.remainingSize());
+
+        pMemStm.reset(new SvMemoryStream);
+        // There may be bytes left over or the codec might read more than
+        // necessary. So to preserve the correctness of the source stream copy
+        // the encoded block
+        pMemStm->WriteStream(rIStm, nCodedSize);
+        pMemStm->Seek(0);
+
+        size_t nSizeInc(4 * pMemStm->remainingSize());
+        if (nUncodedSize < nSizeInc)
+            nSizeInc = nUncodedSize;
+
+        if (nSizeInc > 0)
+        {
+            // decode buffer
+            ZCodec aCodec;
+            aCodec.BeginCompression();
+            aData.resize(nSizeInc);
+            size_t nDataPos(0);
+            while (nUncodedSize > nDataPos)
+            {
+                assert(aData.size() > nDataPos);
+                const size_t nToRead(std::min<size_t>(nUncodedSize - nDataPos, aData.size() - nDataPos));
+                assert(nToRead > 0);
+                assert(!aData.empty());
+                const tools::Long nRead = aCodec.Read(*pMemStm, aData.data() + nDataPos, sal_uInt32(nToRead));
+                if (nRead > 0)
+                {
+                    nDataPos += static_cast<tools::ULong>(nRead);
+                    // we haven't read everything yet: resize buffer and continue
+                    if (nDataPos < nUncodedSize)
+                        aData.resize(aData.size() + nSizeInc);
+                }
+                else
+                {
+                    break;
+                }
+            }
+            // truncate the data buffer to actually read size
+            aData.resize(nDataPos);
+            // set the real uncoded size
+            nUncodedSize = sal_uInt32(aData.size());
+            aCodec.EndCompression();
+        }
+
+        if (aData.empty())
+        {
+            // add something so we can take address of the first element
+            aData.resize(1);
+            nUncodedSize = 0;
+        }
+
+        // set decoded bytes to memory stream,
+        // from which we will read the bitmap data
+        pMemStm.reset(new SvMemoryStream);
+        pIStm = pMemStm.get();
+        assert(!aData.empty());
+        pMemStm->SetBuffer(aData.data(), nUncodedSize, nUncodedSize);
+        nOffset = 0;
+    }
+    else
+    {
+        pIStm = &rIStm;
+    }
+
+    // read palette
+    BitmapPalette aPalette;
+    if (nColors)
+    {
+        aPalette.SetEntryCount(nColors);
+        ImplReadDIBPalette(*pIStm, aPalette, aHeader.nSize != DIBCOREHEADERSIZE);
+    }
+
+    if (pIStm->GetError())
+        return false;
+
+    if (nOffset)
+    {
+        // It is problematic to seek backwards. We are at the
+        // end of BITMAPINFOHEADER or 12 bytes further in case
+        // of WinBMPv3-NT format. It is possible to seek forward
+        // though because a gap may be there.
+        sal_Int32 nSeekRel = nOffset - (pIStm->Tell() - nStmPos);
+        if (nSeekRel > 0)
+            pIStm->SeekRel(nSeekRel);
+    }
+
+    const sal_Int64 nBitsPerLine (static_cast<sal_Int64>(aHeader.nWidth) * static_cast<sal_Int64>(aHeader.nBitCount));
+    if (nBitsPerLine > SAL_MAX_UINT32)
+        return false;
+    const sal_uInt64 nAlignedWidth(AlignedWidth4Bytes(static_cast<sal_uLong>(nBitsPerLine)));
+
+    switch (aHeader.nCompression)
+    {
+        case RLE_8:
+        {
+            if (aHeader.nBitCount != 8)
+                return false;
+            // (partially) check the image dimensions to avoid potential large bitmap allocation if the input is damaged
+            sal_uInt64 nMaxWidth = pIStm->remainingSize();
+            nMaxWidth *= 256;   //assume generous compression ratio
+            nMaxWidth /= aHeader.nHeight;
+            if (nMaxWidth < o3tl::make_unsigned(aHeader.nWidth))
+                return false;
+            break;
+        }
+        case RLE_4:
+        {
+            if (aHeader.nBitCount != 4)
+                return false;
+            sal_uInt64 nMaxWidth = pIStm->remainingSize();
+            nMaxWidth *= 512;   //assume generous compression ratio
+            nMaxWidth /= aHeader.nHeight;
+            if (nMaxWidth < o3tl::make_unsigned(aHeader.nWidth))
+                return false;
+            break;
+        }
+        default:
+            // tdf#122958 invalid compression value used
+            if (aHeader.nCompression & 0x000F)
+            {
+                // lets assume that there was an error in the generating application
+                // and allow through as COMPRESS_NONE if the bottom byte is 0
+                SAL_WARN( "vcl", "bad bmp compression scheme: " << aHeader.nCompression << ", rejecting bmp");
+                return false;
+            }
+            else
+                SAL_WARN( "vcl", "bad bmp compression scheme: " << aHeader.nCompression << ", assuming meant to be COMPRESS_NONE");
+        [[fallthrough]];
+        case BITFIELDS:
+        case ZCOMPRESS:
+        case COMPRESS_NONE:
+        {
+            // (partially) check the image dimensions to avoid potential large bitmap allocation if the input is damaged
+            sal_uInt64 nMaxWidth = pIStm->remainingSize();
+            nMaxWidth /= aHeader.nHeight;
+            if (nMaxWidth < nAlignedWidth)
+                return false;
+            break;
+        }
+    }
+
+    const Size aSizePixel(aHeader.nWidth, aHeader.nHeight);
+    AlphaMask aNewBmpAlpha;
+    AlphaScopedWriteAccess pAccAlpha;
+    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 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 = AlphaMask(aSizePixel);
+        pAccAlpha = AlphaScopedWriteAccess(aNewBmpAlpha);
+    }
+
+    vcl::PixelFormat ePixelFormat(convertToBPP(aHeader.nBitCount));
+    const BitmapPalette* pPal = &aPalette;
+    //ofz#948 match the surrounding logic of case TransparentType::Bitmap of
+    //ReadDIBBitmapEx but do it while reading for performance
+    const bool bIsAlpha = (ePixelFormat == vcl::PixelFormat::N8_BPP &&
+                          !!aPalette && aPalette.IsGreyPalette8Bit());
+    const bool bForceToMonoWhileReading = (bIsMask && !bIsAlpha && ePixelFormat != vcl::PixelFormat::N1_BPP);
+    if (bForceToMonoWhileReading)
+    {
+        pPal = nullptr;
+        ePixelFormat = vcl::PixelFormat::N1_BPP;
+        SAL_WARN( "vcl", "forcing mask to monochrome");
+    }
+
+    Bitmap aNewBmp(aSizePixel, ePixelFormat, pPal);
+    BitmapScopedWriteAccess pAcc(aNewBmp);
+    if (!pAcc)
+        return false;
+    if (pAcc->Width() != aHeader.nWidth || pAcc->Height() != aHeader.nHeight)
+    {
+        return false;
+    }
+
+    // read bits
+    bool bAlphaUsed(false);
+    bool bRet = ImplReadDIBBits(*pIStm, aHeader, *pAcc, aPalette, pAccAlpha.get(), bTopDown, bAlphaUsed, nAlignedWidth, bForceToMonoWhileReading);
+
+    if (bRet && aHeader.nXPelsPerMeter && aHeader.nYPelsPerMeter)
+    {
+        MapMode aMapMode(
+            MapUnit::MapMM,
+            Point(),
+            Fraction(1000, aHeader.nXPelsPerMeter),
+            Fraction(1000, aHeader.nYPelsPerMeter));
+
+        aNewBmp.SetPrefMapMode(aMapMode);
+        aNewBmp.SetPrefSize(Size(aHeader.nWidth, aHeader.nHeight));
+    }
+
+    pAcc.reset();
+
+    if (bAlphaPossible)
+    {
+        pAccAlpha.reset();
+
+        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_uInt64 nStreamLength = rIStm.TellEnd();
+
+    sal_uInt16 nTmp16 = 0;
+    rIStm.ReadUInt16( nTmp16 );
+
+    if ( ( 0x4D42 == nTmp16 ) || ( 0x4142 == nTmp16 ) )
+    {
+        sal_uInt32 nTmp32(0);
+        if ( 0x4142 == nTmp16 )
+        {
+            rIStm.SeekRel( 12 );
+            rIStm.ReadUInt16( nTmp16 );
+            rIStm.SeekRel( 8 );
+            rIStm.ReadUInt32( nTmp32 );
+            rOffset = nTmp32 - 28;
+            bRet = ( 0x4D42 == nTmp16 );
+        }
+        else // 0x4D42 == nTmp16, 'MB' from BITMAPFILEHEADER
+        {
+            rIStm.SeekRel( 8 );        // we are on bfSize member of BITMAPFILEHEADER, forward to bfOffBits
+            rIStm.ReadUInt32( nTmp32 );            // read bfOffBits
+            rOffset = nTmp32 - 14;    // adapt offset by sizeof(BITMAPFILEHEADER)
+            bRet = rIStm.GetError() == ERRCODE_NONE;
+        }
+
+        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 const & rAcc )
+{
+    const sal_uInt16    nColors = rAcc.GetPaletteEntryCount();
+    const sal_uLong     nPalSize = nColors * 4UL;
+    std::unique_ptr<sal_uInt8[]> pEntries(new sal_uInt8[ nPalSize ]);
+    sal_uInt8*          pTmpEntry = pEntries.get();
+
+    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.WriteBytes( pEntries.get(), nPalSize );
+
+    return rOStm.GetError() == ERRCODE_NONE;
+}
+
+bool ImplWriteRLE( SvStream& rOStm, BitmapReadAccess const & 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;
+    std::vector<sal_uInt8> aBuf(( nWidth << 1 ) + 2);
+    sal_uInt8       cPix;
+    sal_uInt8       cLast;
+    bool        bFound;
+
+    for ( tools::Long nY = nHeight - 1; nY >= 0; nY-- )
+    {
+        sal_uInt8* pTmp = aBuf.data();
+        nX = nBufCount = 0;
+        Scanline pScanline = rAcc.GetScanline( nY );
+
+        while( nX < nWidth )
+        {
+            nCount = 1;
+            cPix = rAcc.GetIndexFromData( pScanline, nX++ );
+
+            while( ( nX < nWidth ) && ( nCount < 255 )
+                && ( cPix == rAcc.GetIndexFromData( pScanline, nX ) ) )
+            {
+                nX++;
+                nCount++;
+            }
+
+            if ( nCount > 1 )
+            {
+                *pTmp++ = static_cast<sal_uInt8>(nCount);
+                *pTmp++ = ( bRLE4 ? ( ( cPix << 4 ) | cPix ) : cPix );
+                nBufCount += 2;
+            }
+            else
+            {
+                cLast = cPix;
+                nSaveIndex = nX - 1;
+                bFound = false;
+
+                while( ( nX < nWidth ) && ( nCount < 256 ) )
+                {
+                    cPix = rAcc.GetIndexFromData( pScanline, nX );
+                    if (cPix == cLast)
+                        break;
+                    nX++; nCount++;
+                    cLast = cPix;
+                    bFound = true;
+                }
+
+                if ( bFound )
+                    nX--;
+
+                if ( nCount > 3 )
+                {
+                    *pTmp++ = 0;
+                    *pTmp++ = static_cast<sal_uInt8>(--nCount);
+
+                    if( bRLE4 )
+                    {
+                        for ( sal_uLong i = 0; i < nCount; i++, pTmp++ )
+                        {
+                            *pTmp = rAcc.GetIndexFromData( pScanline, nSaveIndex++ ) << 4;
+
+                            if ( ++i < nCount )
+                                *pTmp |= rAcc.GetIndexFromData( pScanline, nSaveIndex++ );
+                        }
+
+                        nCount = ( nCount + 1 ) >> 1;
+                    }
+                    else
+                    {
+                        for( sal_uLong i = 0; i < nCount; i++ )
+                            *pTmp++ = rAcc.GetIndexFromData( pScanline, nSaveIndex++ );
+                    }
+
+                    if ( nCount & 1 )
+                    {
+                        *pTmp++ = 0;
+                        nBufCount += ( nCount + 3 );
+                    }
+                    else
+                        nBufCount += ( nCount + 2 );
+                }
+                else
+                {
+                    *pTmp++ = 1;
+                    *pTmp++ = rAcc.GetIndexFromData( pScanline, nSaveIndex ) << (bRLE4 ? 4 : 0);
+
+                    if ( nCount == 3 )
+                    {
+                        *pTmp++ = 1;
+                        *pTmp++ = rAcc.GetIndexFromData( pScanline, ++nSaveIndex ) << ( bRLE4 ? 4 : 0 );
+                        nBufCount += 4;
+                    }
+                    else
+                        nBufCount += 2;
+                }
+            }
+        }
+
+        aBuf[ nBufCount++ ] = 0;
+        aBuf[ nBufCount++ ] = 0;
+
+        rOStm.WriteBytes(aBuf.data(), nBufCount);
+    }
+
+    rOStm.WriteUChar( 0 );
+    rOStm.WriteUChar( 1 );
+
+    return rOStm.GetError() == ERRCODE_NONE;
+}
+
+bool ImplWriteDIBBits(SvStream& rOStm, BitmapReadAccess const & rAcc, BitmapReadAccess const * pAccAlpha, sal_uLong nCompression, sal_uInt32& rImageSize)
+{
+    if(!pAccAlpha && BITFIELDS == nCompression)
+    {
+        const ColorMask&    rMask = rAcc.GetColorMask();
+        SVBT32              aVal32;
+
+        UInt32ToSVBT32( rMask.GetRedMask(), aVal32 );
+        rOStm.WriteBytes( aVal32, 4UL );
+
+        UInt32ToSVBT32( rMask.GetGreenMask(), aVal32 );
+        rOStm.WriteBytes( aVal32, 4UL );
+
+        UInt32ToSVBT32( rMask.GetBlueMask(), aVal32 );
+        rOStm.WriteBytes( aVal32, 4UL );
+
+        rImageSize = rOStm.Tell();
+
+        if( rAcc.IsBottomUp() )
+            rOStm.WriteBytes(rAcc.GetBuffer(), rAcc.Height() * rAcc.GetScanlineSize());
+        else
+        {
+            for( tools::Long nY = rAcc.Height() - 1, nScanlineSize = rAcc.GetScanlineSize(); nY >= 0; nY-- )
+                rOStm.WriteBytes( 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 1,8,24
+        // (other cases are not written below)
+        const auto ePixelFormat(pAccAlpha ? vcl::PixelFormat::N32_BPP : convertToBPP(rAcc.GetBitCount()));
+        const sal_uLong nAlignedWidth(AlignedWidth4Bytes(rAcc.Width() * sal_Int32(ePixelFormat)));
+        bool bNative(false);
+
+        switch(rAcc.GetScanlineFormat())
+        {
+            case ScanlineFormat::N1BitMsbPal:
+            case ScanlineFormat::N8BitPal:
+            case ScanlineFormat::N24BitTcBgr:
+            {
+                if(!pAccAlpha && rAcc.IsBottomUp() && (rAcc.GetScanlineSize() == nAlignedWidth))
+                {
+                    bNative = true;
+                }
+
+                break;
+            }
+
+            default:
+            {
+                break;
+            }
+        }
+
+        rImageSize = rOStm.Tell();
+
+        if(bNative)
+        {
+            rOStm.WriteBytes(rAcc.GetBuffer(), nAlignedWidth * rAcc.Height());
+        }
+        else
+        {
+            const tools::Long nWidth(rAcc.Width());
+            const tools::Long nHeight(rAcc.Height());
+            std::vector<sal_uInt8> aBuf(nAlignedWidth);
+            switch(ePixelFormat)
+            {
+                case vcl::PixelFormat::N1_BPP:
+                {
+                    //valgrind, zero out the trailing unused alignment bytes
+                    size_t nUnusedBytes = nAlignedWidth - ((nWidth+7) / 8);
+                    memset(aBuf.data() + nAlignedWidth - nUnusedBytes, 0, nUnusedBytes);
+
+                    for( tools::Long nY = nHeight - 1; nY >= 0; nY-- )
+                    {
+                        sal_uInt8* pTmp = aBuf.data();
+                        sal_uInt8 cTmp = 0;
+                        Scanline pScanline = rAcc.GetScanline( nY );
+
+                        for( tools::Long nX = 0, nShift = 8; nX < nWidth; nX++ )
+                        {
+                            if( !nShift )
+                            {
+                                nShift = 8;
+                                *pTmp++ = cTmp;
+                                cTmp = 0;
+                            }
+
+                            cTmp |= rAcc.GetIndexFromData( pScanline, nX ) << --nShift;
+                        }
+
+                        *pTmp = cTmp;
+                        rOStm.WriteBytes(aBuf.data(), nAlignedWidth);
+                    }
+                }
+                break;
+
+                case vcl::PixelFormat::N8_BPP:
+                {
+                    for( tools::Long nY = nHeight - 1; nY >= 0; nY-- )
+                    {
+                        sal_uInt8* pTmp = aBuf.data();
+                        Scanline pScanline = rAcc.GetScanline( nY );
+
+                        for( tools::Long nX = 0; nX < nWidth; nX++ )
+                            *pTmp++ = rAcc.GetIndexFromData( pScanline, nX );
+
+                        rOStm.WriteBytes(aBuf.data(), nAlignedWidth);
+                    }
+                }
+                break;
+
+                case vcl::PixelFormat::N24_BPP:
+                {
+                    //valgrind, zero out the trailing unused alignment bytes
+                    size_t nUnusedBytes = nAlignedWidth - nWidth * 3;
+                    memset(aBuf.data() + nAlignedWidth - nUnusedBytes, 0, nUnusedBytes);
+                }
+                [[fallthrough]];
+                // #i59239# fallback to 24 bit format, if bitcount is non-default
+                default:
+                {
+                    BitmapColor aPixelColor;
+                    const bool bWriteAlpha(ePixelFormat == vcl::PixelFormat::N32_BPP && pAccAlpha);
+
+                    for( tools::Long nY = nHeight - 1; nY >= 0; nY-- )
+                    {
+                        sal_uInt8* pTmp = aBuf.data();
+                        Scanline pScanlineAlpha = bWriteAlpha ? pAccAlpha->GetScanline( nY ) : nullptr;
+
+                        for( tools::Long nX = 0; 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)
+                            {
+                                *pTmp++ = sal_uInt8(0xff) - pAccAlpha->GetIndexFromData( pScanlineAlpha, nX );
+                            }
+                        }
+
+                        rOStm.WriteBytes(aBuf.data(), nAlignedWidth);
+                    }
+                }
+                break;
+            }
+        }
+    }
+
+    rImageSize = rOStm.Tell() - rImageSize;
+
+    return (!rOStm.GetError());
+}
+
+bool ImplWriteDIBBody(const Bitmap& rBitmap, SvStream& rOStm, BitmapReadAccess const & rAcc, BitmapReadAccess const * pAccAlpha, bool bCompressed)
+{
+    const MapMode aMapPixel(MapUnit::MapPixel);
+    DIBV5Header aHeader;
+    sal_uInt64 nImageSizePos(0);
+    sal_uInt64 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 = 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 1,8,24 (other cases
+        // are not written below)
+        const auto ePixelFormat(pAccAlpha ? vcl::PixelFormat::N32_BPP : convertToBPP(rAcc.GetBitCount()));
+        aHeader.nBitCount = sal_uInt16(ePixelFormat);
+        aHeader.nSizeImage = rAcc.Height() * AlignedWidth4Bytes(rAcc.Width() * aHeader.nBitCount);
+
+        if (bCompressed)
+        {
+            if (ePixelFormat == vcl::PixelFormat::N8_BPP)
+                nCompression = RLE_8;
+        }
+    }
+
+    if((rOStm.GetCompressMode() & SvStreamCompressFlags::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(100000, 100000), MapMode(MapUnit::Map100thMM), rBitmap.GetPrefMapMode()));
+        const double fBmpWidthM(static_cast<double>(rBitmap.GetPrefSize().Width()) / aScale100000.Width());
+        const double fBmpHeightM(static_cast<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.WriteUInt32( aHeader.nSize );
+    rOStm.WriteInt32( aHeader.nWidth );
+    rOStm.WriteInt32( aHeader.nHeight );
+    rOStm.WriteUInt16( aHeader.nPlanes );
+    rOStm.WriteUInt16( aHeader.nBitCount );
+    rOStm.WriteUInt32( aHeader.nCompression );
+
+    nImageSizePos = rOStm.Tell();
+    rOStm.SeekRel( sizeof( aHeader.nSizeImage ) );
+
+    rOStm.WriteInt32( aHeader.nXPelsPerMeter );
+    rOStm.WriteInt32( aHeader.nYPelsPerMeter );
+    rOStm.WriteUInt32( aHeader.nColsUsed );
+    rOStm.WriteUInt32( 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.WriteUInt32( aHeader.nV5RedMask );
+        rOStm.WriteUInt32( aHeader.nV5GreenMask );
+        rOStm.WriteUInt32( aHeader.nV5BlueMask );
+        rOStm.WriteUInt32( aHeader.nV5AlphaMask );
+        rOStm.WriteUInt32( aHeader.nV5CSType );
+
+        rOStm.WriteInt32( aHeader.aV5Endpoints.aXyzRed.aXyzX );
+        rOStm.WriteInt32( aHeader.aV5Endpoints.aXyzRed.aXyzY );
+        rOStm.WriteInt32( aHeader.aV5Endpoints.aXyzRed.aXyzZ );
+        rOStm.WriteInt32( aHeader.aV5Endpoints.aXyzGreen.aXyzX );
+        rOStm.WriteInt32( aHeader.aV5Endpoints.aXyzGreen.aXyzY );
+        rOStm.WriteInt32( aHeader.aV5Endpoints.aXyzGreen.aXyzZ );
+        rOStm.WriteInt32( aHeader.aV5Endpoints.aXyzBlue.aXyzX );
+        rOStm.WriteInt32( aHeader.aV5Endpoints.aXyzBlue.aXyzY );
+        rOStm.WriteInt32( aHeader.aV5Endpoints.aXyzBlue.aXyzZ );
+
+        rOStm.WriteUInt32( aHeader.nV5GammaRed );
+        rOStm.WriteUInt32( aHeader.nV5GammaGreen );
+        rOStm.WriteUInt32( aHeader.nV5GammaBlue );
+        rOStm.WriteUInt32( aHeader.nV5Intent );
+        rOStm.WriteUInt32( aHeader.nV5ProfileData );
+        rOStm.WriteUInt32( aHeader.nV5ProfileSize );
+        rOStm.WriteUInt32( aHeader.nV5Reserved );
+    }
+
+    if(ZCOMPRESS == aHeader.nCompression)
+    {
+        ZCodec aCodec;
+        SvMemoryStream aMemStm(aHeader.nSizeImage + 4096, 65535);
+        sal_uInt64 nCodedPos(rOStm.Tell());
+        sal_uInt64 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, static_cast<sal_uInt8 const *>(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.WriteUInt32( nCodedSize ).WriteUInt32( nUncodedSize ).WriteUInt32( 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.WriteUInt32( aHeader.nSizeImage );
+    rOStm.Seek(nEndPos);
+
+    return bRet;
+}
+
+bool ImplWriteDIBFileHeader(SvStream& rOStm, BitmapReadAccess const & rAcc)
+{
+    const sal_uInt32 nPalCount((rAcc.HasPalette() ? rAcc.GetPaletteEntryCount() : isBitfieldCompression(rAcc.GetScanlineFormat()) ? 3UL : 0UL));
+    const sal_uInt32 nOffset(14 + DIBINFOHEADERSIZE + nPalCount * 4UL);
+
+    rOStm.WriteUInt16( 0x4D42 ); // 'MB' from BITMAPFILEHEADER
+    rOStm.WriteUInt32( nOffset + (rAcc.Height() * rAcc.GetScanlineSize()) );
+    rOStm.WriteUInt16( 0 );
+    rOStm.WriteUInt16( 0 );
+    rOStm.WriteUInt32( nOffset );
+
+    return rOStm.GetError() == ERRCODE_NONE;
+}
+
+bool ImplReadDIB(
+    Bitmap& rTarget,
+    AlphaMask* pTargetAlpha,
+    SvStream& rIStm,
+    bool bFileHeader,
+    bool bIsMask=false,
+    bool bMSOFormat=false)
+{
+    const SvStreamEndian nOldFormat(rIStm.GetEndian());
+    const auto nOldPos(rIStm.Tell());
+    sal_uLong nOffset(0);
+    bool bRet(false);
+
+    rIStm.SetEndian(SvStreamEndian::LITTLE);
+
+    if(bFileHeader)
+    {
+        if(ImplReadDIBFileHeader(rIStm, nOffset))
+        {
+            bRet = ImplReadDIBBody(rIStm, rTarget, nOffset >= DIBV5HEADERSIZE ? pTargetAlpha : nullptr, nOffset, bIsMask, bMSOFormat);
+        }
+    }
+    else
+    {
+        bRet = ImplReadDIBBody(rIStm, rTarget, nullptr, nOffset, bIsMask, bMSOFormat);
+    }
+
+    if(!bRet)
+    {
+        if(!rIStm.GetError()) // Set error and stop processing whole stream due to security reason
+        {
+            rIStm.SetError(SVSTREAM_GENERALERROR);
+        }
+
+        rIStm.Seek(nOldPos);
+    }
+
+    rIStm.SetEndian(nOldFormat);
+
+    return bRet;
+}
+
+bool ImplWriteDIB(
+    const Bitmap& rSource,
+    SvStream& rOStm,
+    bool bCompressed,
+    bool bFileHeader)
+{
+    const Size aSizePix(rSource.GetSizePixel());
+    bool bRet(false);
+
+    if(aSizePix.Width() && aSizePix.Height())
+    {
+        Bitmap::ScopedReadAccess pAcc(const_cast< Bitmap& >(rSource));
+        Bitmap::ScopedReadAccess pAccAlpha;
+        const SvStreamEndian nOldFormat(rOStm.GetEndian());
+        const sal_uInt64 nOldPos(rOStm.Tell());
+
+        rOStm.SetEndian(SvStreamEndian::LITTLE);
+
+        if (pAcc)
+        {
+            if(bFileHeader)
+            {
+                if(ImplWriteDIBFileHeader(rOStm, *pAcc))
+                {
+                    bRet = ImplWriteDIBBody(rSource, rOStm, *pAcc, pAccAlpha.get(), bCompressed);
+                }
+            }
+            else
+            {
+                bRet = ImplWriteDIBBody(rSource, rOStm, *pAcc, pAccAlpha.get(), bCompressed);
+            }
+
+            pAcc.reset();
+        }
+
+        pAccAlpha.reset();
+
+        if(!bRet)
+        {
+            rOStm.SetError(SVSTREAM_GENERALERROR);
+            rOStm.Seek(nOldPos);
+        }
+
+        rOStm.SetEndian(nOldFormat);
+    }
+
+    return bRet;
+}
+
+} // unnamed namespace
+
+bool ReadDIB(
+    Bitmap& rTarget,
+    SvStream& rIStm,
+    bool bFileHeader,
+    bool bMSOFormat)
+{
+    return ImplReadDIB(rTarget, nullptr, rIStm, bFileHeader, false, bMSOFormat);
+}
+
+bool ReadDIBBitmapEx(
+    BitmapEx& rTarget,
+    SvStream& rIStm,
+    bool bFileHeader,
+    bool bMSOFormat)
+{
+    Bitmap aBmp;
+    bool bRetval(ImplReadDIB(aBmp, nullptr, rIStm, bFileHeader, /*bMask*/false, bMSOFormat) && !rIStm.GetError());
+
+    if(bRetval)
+    {
+        // base bitmap was read, set as return value and try to read alpha extra-data
+        const sal_uInt64 nStmPos(rIStm.Tell());
+        sal_uInt32 nMagic1(0);
+        sal_uInt32 nMagic2(0);
+
+        rTarget = BitmapEx(aBmp);
+        if (rIStm.remainingSize() >= 4)
+            rIStm.ReadUInt32( nMagic1 ).ReadUInt32( nMagic2 );
+        bRetval = (0x25091962 == nMagic1) && (0xACB20201 == nMagic2) && !rIStm.GetError();
+
+        if(bRetval)
+        {
+            sal_uInt8 tmp = 0;
+            rIStm.ReadUChar( tmp );
+            bRetval = !rIStm.GetError();
+
+            if(bRetval)
+            {
+                switch (tmp)
+                {
+                case 2: // TransparentType::Bitmap
+                    {
+                        Bitmap aMask;
+
+                        bRetval = ImplReadDIB(aMask, nullptr, rIStm, true, true);
+
+                        if(bRetval)
+                        {
+                            if(!aMask.IsEmpty())
+                            {
+                                // do we have an alpha mask?
+                                if (aMask.getPixelFormat() == vcl::PixelFormat::N8_BPP && aMask.HasGreyPalette8Bit())
+                                {
+                                    AlphaMask aAlpha;
+
+                                    // create alpha mask quickly (without greyscale conversion)
+                                    aAlpha.ImplSetBitmap(aMask);
+                                    rTarget = BitmapEx(aBmp, aAlpha);
+                                }
+                                else
+                                {
+                                    rTarget = BitmapEx(aBmp, aMask);
+                                }
+                            }
+                        }
+                        break;
+                    }
+                case 1: // backwards compat for old option TransparentType::Color
+                    {
+                        Color aTransparentColor;
+
+                        tools::GenericTypeSerializer aSerializer(rIStm);
+                        aSerializer.readColor(aTransparentColor);
+
+                        bRetval = rIStm.good();
+
+                        if(bRetval)
+                        {
+                            rTarget = BitmapEx(aBmp, aTransparentColor);
+                        }
+                        break;
+                    }
+                default: break;
+                }
+            }
+        }
+
+        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,
+    AlphaMask& rTargetAlpha,
+    SvStream& rIStm)
+{
+    return ImplReadDIB(rTarget, &rTargetAlpha, rIStm, true);
+}
+
+bool ReadRawDIB(
+    BitmapEx& rTarget,
+    const unsigned char* pBuf,
+    const ScanlineFormat nFormat,
+    const int nHeight,
+    const int nStride)
+{
+    BitmapScopedWriteAccess pWriteAccess(rTarget.maBitmap.AcquireWriteAccess(), rTarget.maBitmap);
+    for (int nRow = 0; nRow < nHeight; ++nRow)
+    {
+        pWriteAccess->CopyScanline(nRow, pBuf + (nStride * nRow), nFormat, nStride);
+    }
+
+    return true;
+}
+
+bool WriteDIB(
+    const Bitmap& rSource,
+    SvStream& rOStm,
+    bool bCompressed,
+    bool bFileHeader)
+{
+    return ImplWriteDIB(rSource, rOStm, bCompressed, bFileHeader);
+}
+
+bool WriteDIB(
+    const BitmapEx& rSource,
+    SvStream& rOStm,
+    bool bCompressed)
+{
+    return ImplWriteDIB(rSource.GetBitmap(), rOStm, bCompressed, /*bFileHeader*/true);
+}
+
+bool WriteDIBBitmapEx(
+    const BitmapEx& rSource,
+    SvStream& rOStm)
+{
+    if(ImplWriteDIB(rSource.GetBitmap(), rOStm, true, true))
+    {
+        rOStm.WriteUInt32( 0x25091962 );
+        rOStm.WriteUInt32( 0xACB20201 );
+        rOStm.WriteUChar( rSource.IsAlpha() ? 2 : 0 ); // Used to be TransparentType enum
+
+        if(rSource.IsAlpha())
+        {
+            return ImplWriteDIB(rSource.maAlphaMask, rOStm, true, true);
+        }
+    }
+
+    return false;
+}
+
+sal_uInt32 getDIBV5HeaderSize()
+{
+    return DIBV5HEADERSIZE;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */