SampleAdaptiveOffset.cpp

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/** \file     SampleAdaptiveOffset.cpp
    \brief    sample adaptive offset class
*/

#include "SampleAdaptiveOffset.h"

#include "UnitTools.h"
#include "UnitPartitioner.h"
#include "CodingStructure.h"
#include "CommonLib/dtrace_codingstruct.h"
#include "CommonLib/dtrace_buffer.h"

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>

//! \ingroup CommonLib
//! \{

SAOOffset::SAOOffset()
{
  reset();
}

SAOOffset::~SAOOffset()
{

}

void SAOOffset::reset()
{
  modeIdc = SAO_MODE_OFF;
  typeIdc = -1;
  typeAuxInfo = -1;
  ::memset(offset, 0, sizeof(int)* MAX_NUM_SAO_CLASSES);
}

const SAOOffset& SAOOffset::operator= (const SAOOffset& src)
{
  modeIdc = src.modeIdc;
  typeIdc = src.typeIdc;
  typeAuxInfo = src.typeAuxInfo;
  ::memcpy(offset, src.offset, sizeof(int)* MAX_NUM_SAO_CLASSES);

  return *this;
}


SAOBlkParam::SAOBlkParam()
{
  reset();
}

SAOBlkParam::~SAOBlkParam()
{

}

void SAOBlkParam::reset()
{
  for(int compIdx = 0; compIdx < MAX_NUM_COMPONENT; compIdx++)
  {
    offsetParam[compIdx].reset();
  }
}

const SAOBlkParam& SAOBlkParam::operator= (const SAOBlkParam& src)
{
  for(int compIdx = 0; compIdx < MAX_NUM_COMPONENT; compIdx++)
  {
    offsetParam[compIdx] = src.offsetParam[compIdx];
  }
  return *this;
}




SampleAdaptiveOffset::SampleAdaptiveOffset()
{
  m_numberOfComponents = 0;
}


SampleAdaptiveOffset::~SampleAdaptiveOffset()
{
  destroy();

  m_signLineBuf1.clear();
  m_signLineBuf2.clear();
}

void SampleAdaptiveOffset::create( int picWidth, int picHeight, ChromaFormat format, uint32_t maxCUWidth, uint32_t maxCUHeight, uint32_t maxCUDepth, uint32_t lumaBitShift, uint32_t chromaBitShift )
{
  //temporary picture buffer
  UnitArea picArea(format, Area(0, 0, picWidth, picHeight));

  m_tempBuf.destroy();
  m_tempBuf.create( picArea );

  //bit-depth related
  for(int compIdx = 0; compIdx < MAX_NUM_COMPONENT; compIdx++)
  {
    m_offsetStepLog2  [compIdx] = isLuma(ComponentID(compIdx))? lumaBitShift : chromaBitShift;
  }
  m_numberOfComponents = getNumberValidComponents(format);
}

void SampleAdaptiveOffset::destroy()
{
  m_tempBuf.destroy();
}

void SampleAdaptiveOffset::invertQuantOffsets(ComponentID compIdx, int typeIdc, int typeAuxInfo, int* dstOffsets, int* srcOffsets)
{
  int codedOffset[MAX_NUM_SAO_CLASSES];

  ::memcpy(codedOffset, srcOffsets, sizeof(int)*MAX_NUM_SAO_CLASSES);
  ::memset(dstOffsets, 0, sizeof(int)*MAX_NUM_SAO_CLASSES);

  if(typeIdc == SAO_TYPE_START_BO)
  {
    for(int i=0; i< 4; i++)
    {
      dstOffsets[(typeAuxInfo+ i)%NUM_SAO_BO_CLASSES] = codedOffset[(typeAuxInfo+ i)%NUM_SAO_BO_CLASSES]*(1<<m_offsetStepLog2[compIdx]);
    }
  }
  else //EO
  {
    for(int i=0; i< NUM_SAO_EO_CLASSES; i++)
    {
      dstOffsets[i] = codedOffset[i] *(1<<m_offsetStepLog2[compIdx]);
    }
    CHECK(dstOffsets[SAO_CLASS_EO_PLAIN] != 0, "EO offset is not '0'"); //keep EO plain offset as zero
  }

}

int SampleAdaptiveOffset::getMergeList(CodingStructure& cs, int ctuRsAddr, SAOBlkParam* blkParams, SAOBlkParam* mergeList[NUM_SAO_MERGE_TYPES])
{
  const PreCalcValues& pcv = *cs.pcv;

  int ctuX = ctuRsAddr % pcv.widthInCtus;
  int ctuY = ctuRsAddr / pcv.widthInCtus;
  const CodingUnit& cu = *cs.getCU(Position(ctuX*pcv.maxCUWidth, ctuY*pcv.maxCUHeight), CH_L);
  int mergedCTUPos;
  int numValidMergeCandidates = 0;

  for(int mergeType=0; mergeType< NUM_SAO_MERGE_TYPES; mergeType++)
  {
    SAOBlkParam* mergeCandidate = NULL;

    switch(mergeType)
    {
    case SAO_MERGE_ABOVE:
      {
        if(ctuY > 0)
        {
          mergedCTUPos = ctuRsAddr- pcv.widthInCtus;
          if(cs.getCURestricted(Position(ctuX*pcv.maxCUWidth, (ctuY-1)*pcv.maxCUHeight), cu, cu.chType))
          {
            mergeCandidate = &(blkParams[mergedCTUPos]);
          }
        }
      }
      break;
    case SAO_MERGE_LEFT:
      {
        if(ctuX > 0)
        {
          mergedCTUPos = ctuRsAddr- 1;
          if(cs.getCURestricted(Position((ctuX-1)*pcv.maxCUWidth, ctuY*pcv.maxCUHeight), cu, cu.chType))
          {
            mergeCandidate = &(blkParams[mergedCTUPos]);
          }
        }
      }
      break;
    default:
      {
        THROW("not a supported merge type");
      }
    }

    mergeList[mergeType]=mergeCandidate;
    if (mergeCandidate != NULL)
    {
      numValidMergeCandidates++;
    }
  }

  return numValidMergeCandidates;
}


void SampleAdaptiveOffset::reconstructBlkSAOParam(SAOBlkParam& recParam, SAOBlkParam* mergeList[NUM_SAO_MERGE_TYPES])
{
  const int numberOfComponents = m_numberOfComponents;
  for(int compIdx = 0; compIdx < numberOfComponents; compIdx++)
  {
    const ComponentID component = ComponentID(compIdx);
    SAOOffset& offsetParam = recParam[component];

    if(offsetParam.modeIdc == SAO_MODE_OFF)
    {
      continue;
    }

    switch(offsetParam.modeIdc)
    {
    case SAO_MODE_NEW:
      {
        invertQuantOffsets(component, offsetParam.typeIdc, offsetParam.typeAuxInfo, offsetParam.offset, offsetParam.offset);
      }
      break;
    case SAO_MODE_MERGE:
      {
        SAOBlkParam* mergeTarget = mergeList[offsetParam.typeIdc];
        CHECK(mergeTarget == NULL, "Merge target does not exist");

        offsetParam = (*mergeTarget)[component];
      }
      break;
    default:
      {
        THROW("Not a supported mode");
      }
    }
  }
}

void SampleAdaptiveOffset::xReconstructBlkSAOParams(CodingStructure& cs, SAOBlkParam* saoBlkParams)
{
  for(uint32_t compIdx = 0; compIdx < MAX_NUM_COMPONENT; compIdx++)
  {
    m_picSAOEnabled[compIdx] = false;
  }

  const uint32_t numberOfComponents = getNumberValidComponents(cs.pcv->chrFormat);

  for(int ctuRsAddr=0; ctuRsAddr< cs.pcv->sizeInCtus; ctuRsAddr++)
  {
    SAOBlkParam* mergeList[NUM_SAO_MERGE_TYPES] = { NULL };
    getMergeList(cs, ctuRsAddr, saoBlkParams, mergeList);

    reconstructBlkSAOParam(saoBlkParams[ctuRsAddr], mergeList);

    for(uint32_t compIdx = 0; compIdx < numberOfComponents; compIdx++)
    {
      if(saoBlkParams[ctuRsAddr][compIdx].modeIdc != SAO_MODE_OFF)
      {
        m_picSAOEnabled[compIdx] = true;
      }
    }
  }
}


void SampleAdaptiveOffset::offsetBlock(const int channelBitDepth, const ClpRng& clpRng, int typeIdx, int* offset
                                          , const Pel* srcBlk, Pel* resBlk, int srcStride, int resStride,  int width, int height
                                          , bool isLeftAvail,  bool isRightAvail, bool isAboveAvail, bool isBelowAvail, bool isAboveLeftAvail, bool isAboveRightAvail, bool isBelowLeftAvail, bool isBelowRightAvail
                                          , bool isCtuCrossedByVirtualBoundaries, int horVirBndryPos[], int verVirBndryPos[], int numHorVirBndry, int numVerVirBndry
  )
{
  int x,y, startX, startY, endX, endY, edgeType;
  int firstLineStartX, firstLineEndX, lastLineStartX, lastLineEndX;
  int8_t signLeft, signRight, signDown;

  const Pel* srcLine = srcBlk;
        Pel* resLine = resBlk;

  switch(typeIdx)
  {
  case SAO_TYPE_EO_0:
    {
      offset += 2;
      startX = isLeftAvail ? 0 : 1;
      endX   = isRightAvail ? width : (width -1);
      for (y=0; y< height; y++)
      {
        signLeft = (int8_t)sgn(srcLine[startX] - srcLine[startX-1]);
        for (x=startX; x< endX; x++)
        {
          signRight = (int8_t)sgn(srcLine[x] - srcLine[x+1]);
          if (isCtuCrossedByVirtualBoundaries && isProcessDisabled(x, y, numVerVirBndry, 0, verVirBndryPos, horVirBndryPos))
          {
            signLeft = -signRight;
            continue;
          }
          edgeType =  signRight + signLeft;
          signLeft  = -signRight;

          resLine[x] = ClipPel<int>( srcLine[x] + offset[edgeType], clpRng);
        }
        srcLine  += srcStride;
        resLine += resStride;
      }

    }
    break;
  case SAO_TYPE_EO_90:
    {
      offset += 2;
      int8_t *signUpLine = &m_signLineBuf1[0];

      startY = isAboveAvail ? 0 : 1;
      endY   = isBelowAvail ? height : height-1;
      if (!isAboveAvail)
      {
        srcLine += srcStride;
        resLine += resStride;
      }

      const Pel* srcLineAbove= srcLine- srcStride;
      for (x=0; x< width; x++)
      {
        signUpLine[x] = (int8_t)sgn(srcLine[x] - srcLineAbove[x]);
      }

      const Pel* srcLineBelow;
      for (y=startY; y<endY; y++)
      {
        srcLineBelow= srcLine+ srcStride;

        for (x=0; x< width; x++)
        {
          signDown  = (int8_t)sgn(srcLine[x] - srcLineBelow[x]);
          if (isCtuCrossedByVirtualBoundaries && isProcessDisabled(x, y, 0, numHorVirBndry, verVirBndryPos, horVirBndryPos))
          {
            signUpLine[x] = -signDown;
            continue;
          }
          edgeType = signDown + signUpLine[x];
          signUpLine[x]= -signDown;

          resLine[x] = ClipPel<int>(srcLine[x] + offset[edgeType], clpRng);
        }
        srcLine += srcStride;
        resLine += resStride;
      }

    }
    break;
  case SAO_TYPE_EO_135:
    {
      offset += 2;
      int8_t *signUpLine, *signDownLine, *signTmpLine;

      signUpLine  = &m_signLineBuf1[0];
      signDownLine= &m_signLineBuf2[0];

      startX = isLeftAvail ? 0 : 1 ;
      endX   = isRightAvail ? width : (width-1);

      //prepare 2nd line's upper sign
      const Pel* srcLineBelow= srcLine+ srcStride;
      for (x=startX; x< endX+1; x++)
      {
        signUpLine[x] = (int8_t)sgn(srcLineBelow[x] - srcLine[x- 1]);
      }

      //1st line
      const Pel* srcLineAbove= srcLine- srcStride;
      firstLineStartX = isAboveLeftAvail ? 0 : 1;
      firstLineEndX   = isAboveAvail? endX: 1;
      for(x= firstLineStartX; x< firstLineEndX; x++)
      {
        if (isCtuCrossedByVirtualBoundaries && isProcessDisabled(x, 0, numVerVirBndry, numHorVirBndry, verVirBndryPos, horVirBndryPos))
        {
          continue;
        }
        edgeType  =  sgn(srcLine[x] - srcLineAbove[x- 1]) - signUpLine[x+1];

        resLine[x] = ClipPel<int>( srcLine[x] + offset[edgeType], clpRng);
      }
      srcLine  += srcStride;
      resLine  += resStride;


      //middle lines
      for (y= 1; y< height-1; y++)
      {
        srcLineBelow= srcLine+ srcStride;

        for (x=startX; x<endX; x++)
        {
          signDown =  (int8_t)sgn(srcLine[x] - srcLineBelow[x+ 1]);
          if (isCtuCrossedByVirtualBoundaries && isProcessDisabled(x, y, numVerVirBndry, numHorVirBndry, verVirBndryPos, horVirBndryPos))
          {
            signDownLine[x + 1] = -signDown;
            continue;
          }
          edgeType =  signDown + signUpLine[x];
          resLine[x] = ClipPel<int>( srcLine[x] + offset[edgeType], clpRng);

          signDownLine[x+1] = -signDown;
        }
        signDownLine[startX] = (int8_t)sgn(srcLineBelow[startX] - srcLine[startX-1]);

        signTmpLine  = signUpLine;
        signUpLine   = signDownLine;
        signDownLine = signTmpLine;

        srcLine += srcStride;
        resLine += resStride;
      }

      //last line
      srcLineBelow= srcLine+ srcStride;
      lastLineStartX = isBelowAvail ? startX : (width -1);
      lastLineEndX   = isBelowRightAvail ? width : (width -1);
      for(x= lastLineStartX; x< lastLineEndX; x++)
      {
        if (isCtuCrossedByVirtualBoundaries && isProcessDisabled(x, height - 1, numVerVirBndry, numHorVirBndry, verVirBndryPos, horVirBndryPos))
        {
          continue;
        }
        edgeType =  sgn(srcLine[x] - srcLineBelow[x+ 1]) + signUpLine[x];
        resLine[x] = ClipPel<int>( srcLine[x] + offset[edgeType], clpRng);

      }
    }
    break;
  case SAO_TYPE_EO_45:
    {
      offset += 2;
      int8_t *signUpLine = &m_signLineBuf1[1];

      startX = isLeftAvail ? 0 : 1;
      endX   = isRightAvail ? width : (width -1);

      //prepare 2nd line upper sign
      const Pel* srcLineBelow= srcLine+ srcStride;
      for (x=startX-1; x< endX; x++)
      {
        signUpLine[x] = (int8_t)sgn(srcLineBelow[x] - srcLine[x+1]);
      }


      //first line
      const Pel* srcLineAbove= srcLine- srcStride;
      firstLineStartX = isAboveAvail ? startX : (width -1 );
      firstLineEndX   = isAboveRightAvail ? width : (width-1);
      for(x= firstLineStartX; x< firstLineEndX; x++)
      {
        if (isCtuCrossedByVirtualBoundaries && isProcessDisabled(x, 0, numVerVirBndry, numHorVirBndry, verVirBndryPos, horVirBndryPos))
        {
          continue;
        }
        edgeType = sgn(srcLine[x] - srcLineAbove[x+1]) -signUpLine[x-1];
        resLine[x] = ClipPel<int>(srcLine[x] + offset[edgeType], clpRng);
      }
      srcLine += srcStride;
      resLine += resStride;

      //middle lines
      for (y= 1; y< height-1; y++)
      {
        srcLineBelow= srcLine+ srcStride;

        for(x= startX; x< endX; x++)
        {
          signDown =  (int8_t)sgn(srcLine[x] - srcLineBelow[x-1]);
          if (isCtuCrossedByVirtualBoundaries && isProcessDisabled(x, y, numVerVirBndry, numHorVirBndry, verVirBndryPos, horVirBndryPos))
          {
            signUpLine[x - 1] = -signDown;
            continue;
          }
          edgeType =  signDown + signUpLine[x];
          resLine[x] = ClipPel<int>(srcLine[x] + offset[edgeType], clpRng);
          signUpLine[x-1] = -signDown;
        }
        signUpLine[endX-1] = (int8_t)sgn(srcLineBelow[endX-1] - srcLine[endX]);
        srcLine  += srcStride;
        resLine += resStride;
      }

      //last line
      srcLineBelow= srcLine+ srcStride;
      lastLineStartX = isBelowLeftAvail ? 0 : 1;
      lastLineEndX   = isBelowAvail ? endX : 1;
      for(x= lastLineStartX; x< lastLineEndX; x++)
      {
        if (isCtuCrossedByVirtualBoundaries && isProcessDisabled(x, height - 1, numVerVirBndry, numHorVirBndry, verVirBndryPos, horVirBndryPos))
        {
          continue;
        }
        edgeType = sgn(srcLine[x] - srcLineBelow[x-1]) + signUpLine[x];
        resLine[x] = ClipPel<int>(srcLine[x] + offset[edgeType], clpRng);

      }
    }
    break;
  case SAO_TYPE_BO:
    {
      const int shiftBits = channelBitDepth - NUM_SAO_BO_CLASSES_LOG2;
      for (y=0; y< height; y++)
      {
        for (x=0; x< width; x++)
        {
          resLine[x] = ClipPel<int>(srcLine[x] + offset[srcLine[x] >> shiftBits], clpRng );
        }
        srcLine += srcStride;
        resLine += resStride;
      }
    }
    break;
  default:
    {
      THROW("Not a supported SAO types\n");
    }
  }
}

void SampleAdaptiveOffset::offsetCTU( const UnitArea& area, const CPelUnitBuf& src, PelUnitBuf& res, SAOBlkParam& saoblkParam, CodingStructure& cs)
{
  const uint32_t numberOfComponents = getNumberValidComponents( area.chromaFormat );
  bool bAllOff=true;
  for( uint32_t compIdx = 0; compIdx < numberOfComponents; compIdx++)
  {
    if (saoblkParam[compIdx].modeIdc != SAO_MODE_OFF)
    {
      bAllOff=false;
    }
  }
  if (bAllOff)
  {
    return;
  }

  bool isLeftAvail, isRightAvail, isAboveAvail, isBelowAvail, isAboveLeftAvail, isAboveRightAvail, isBelowLeftAvail, isBelowRightAvail;

  //block boundary availability
  deriveLoopFilterBoundaryAvailibility(cs, area.Y(), isLeftAvail,isRightAvail,isAboveAvail,isBelowAvail,isAboveLeftAvail,isAboveRightAvail,isBelowLeftAvail,isBelowRightAvail);

  const size_t lineBufferSize = area.Y().width + 1;
  if (m_signLineBuf1.size() < lineBufferSize)
  {
    m_signLineBuf1.resize(lineBufferSize);
    m_signLineBuf2.resize(lineBufferSize);
  }

  int numHorVirBndry = 0, numVerVirBndry = 0;
  int horVirBndryPos[] = { -1,-1,-1 };
  int verVirBndryPos[] = { -1,-1,-1 };
  int horVirBndryPosComp[] = { -1,-1,-1 };
  int verVirBndryPosComp[] = { -1,-1,-1 };
#if JVET_P1006_PICTURE_HEADER
  bool isCtuCrossedByVirtualBoundaries = isCrossedByVirtualBoundaries(area.Y().x, area.Y().y, area.Y().width, area.Y().height, numHorVirBndry, numVerVirBndry, horVirBndryPos, verVirBndryPos, cs.picHeader );
#else
  bool isCtuCrossedByVirtualBoundaries = isCrossedByVirtualBoundaries(area.Y().x, area.Y().y, area.Y().width, area.Y().height, numHorVirBndry, numVerVirBndry, horVirBndryPos, verVirBndryPos, cs.slice->getPPS());
#endif
  for(int compIdx = 0; compIdx < numberOfComponents; compIdx++)
  {
    const ComponentID compID = ComponentID(compIdx);
    const CompArea& compArea = area.block(compID);
    SAOOffset& ctbOffset     = saoblkParam[compIdx];

    if(ctbOffset.modeIdc != SAO_MODE_OFF)
    {
      int  srcStride    = src.get(compID).stride;
      const Pel* srcBlk = src.get(compID).bufAt(compArea);
      int  resStride    = res.get(compID).stride;
      Pel* resBlk       = res.get(compID).bufAt(compArea);
      for (int i = 0; i < numHorVirBndry; i++)
      {
        horVirBndryPosComp[i] = (horVirBndryPos[i] >> ::getComponentScaleY(compID, area.chromaFormat)) - compArea.y;
      }
      for (int i = 0; i < numVerVirBndry; i++)
      {
        verVirBndryPosComp[i] = (verVirBndryPos[i] >> ::getComponentScaleX(compID, area.chromaFormat)) - compArea.x;
      }

      offsetBlock( cs.sps->getBitDepth(toChannelType(compID)),
                   cs.slice->clpRng(compID),
                   ctbOffset.typeIdc, ctbOffset.offset
                  , srcBlk, resBlk, srcStride, resStride, compArea.width, compArea.height
                  , isLeftAvail, isRightAvail
                  , isAboveAvail, isBelowAvail
                  , isAboveLeftAvail, isAboveRightAvail
                  , isBelowLeftAvail, isBelowRightAvail
                  , isCtuCrossedByVirtualBoundaries, horVirBndryPosComp, verVirBndryPosComp, numHorVirBndry, numVerVirBndry
                  );
    }
  } //compIdx
}

void SampleAdaptiveOffset::SAOProcess( CodingStructure& cs, SAOBlkParam* saoBlkParams
                                      )
{
  CHECK(!saoBlkParams, "No parameters present");

  xReconstructBlkSAOParams(cs, saoBlkParams);

  const uint32_t numberOfComponents = getNumberValidComponents(cs.area.chromaFormat);
  bool bAllDisabled = true;
  for (uint32_t compIdx = 0; compIdx < numberOfComponents; compIdx++)
  {
    if (m_picSAOEnabled[compIdx])
    {
      bAllDisabled = false;
    }
  }
  if (bAllDisabled)
  {
    return;
  }

  const PreCalcValues& pcv = *cs.pcv;
  PelUnitBuf rec = cs.getRecoBuf();
  m_tempBuf.copyFrom( rec );

  int ctuRsAddr = 0;
  for( uint32_t yPos = 0; yPos < pcv.lumaHeight; yPos += pcv.maxCUHeight )
  {
    for( uint32_t xPos = 0; xPos < pcv.lumaWidth; xPos += pcv.maxCUWidth )
    {
      const uint32_t width  = (xPos + pcv.maxCUWidth  > pcv.lumaWidth)  ? (pcv.lumaWidth - xPos)  : pcv.maxCUWidth;
      const uint32_t height = (yPos + pcv.maxCUHeight > pcv.lumaHeight) ? (pcv.lumaHeight - yPos) : pcv.maxCUHeight;
      const UnitArea area( cs.area.chromaFormat, Area(xPos , yPos, width, height) );

      offsetCTU( area, m_tempBuf, rec, cs.picture->getSAO()[ctuRsAddr], cs);
      ctuRsAddr++;
    }
  }

  DTRACE_UPDATE(g_trace_ctx, (std::make_pair("poc", cs.slice->getPOC())));
  DTRACE_PIC_COMP(D_REC_CB_LUMA_SAO, cs, cs.getRecoBuf(), COMPONENT_Y);
  DTRACE_PIC_COMP(D_REC_CB_CHROMA_SAO, cs, cs.getRecoBuf(), COMPONENT_Cb);
  DTRACE_PIC_COMP(D_REC_CB_CHROMA_SAO, cs, cs.getRecoBuf(), COMPONENT_Cr);

  DTRACE    ( g_trace_ctx, D_CRC, "SAO" );
  DTRACE_CRC( g_trace_ctx, D_CRC, cs, cs.getRecoBuf() );

}


void SampleAdaptiveOffset::deriveLoopFilterBoundaryAvailibility(CodingStructure& cs, const Position &pos,
  bool& isLeftAvail,
  bool& isRightAvail,
  bool& isAboveAvail,
  bool& isBelowAvail,
  bool& isAboveLeftAvail,
  bool& isAboveRightAvail,
  bool& isBelowLeftAvail,
  bool& isBelowRightAvail
  ) const
{
  const int width = cs.pcv->maxCUWidth;
  const int height = cs.pcv->maxCUHeight;
  const CodingUnit* cuCurr = cs.getCU(pos, CH_L);
  const CodingUnit* cuLeft = cs.getCU(pos.offset(-width, 0), CH_L);
  const CodingUnit* cuRight = cs.getCU(pos.offset(width, 0), CH_L);
  const CodingUnit* cuAbove = cs.getCU(pos.offset(0, -height), CH_L);
  const CodingUnit* cuBelow = cs.getCU(pos.offset(0, height), CH_L);
  const CodingUnit* cuAboveLeft = cs.getCU(pos.offset(-width, -height), CH_L);
  const CodingUnit* cuAboveRight = cs.getCU(pos.offset(width, -height), CH_L);
  const CodingUnit* cuBelowLeft = cs.getCU(pos.offset(-width, height), CH_L);
  const CodingUnit* cuBelowRight = cs.getCU(pos.offset(width, height), CH_L);

  // check cross slice flags
#if JVET_P1006_PICTURE_HEADER
  const bool isLoopFilterAcrossSlicePPS = cs.pps->getLoopFilterAcrossSlicesEnabledFlag();
  if (!isLoopFilterAcrossSlicePPS)
  {
    isLeftAvail       = (cuLeft == NULL)       ? false : CU::isSameSlice(*cuCurr, *cuLeft);
    isAboveAvail      = (cuAbove == NULL)      ? false : CU::isSameSlice(*cuCurr, *cuAbove);
    isRightAvail      = (cuRight == NULL)      ? false : CU::isSameSlice(*cuCurr, *cuRight);
    isBelowAvail      = (cuBelow == NULL)      ? false : CU::isSameSlice(*cuCurr, *cuBelow);
    isAboveLeftAvail  = (cuAboveLeft == NULL)  ? false : CU::isSameSlice(*cuCurr, *cuAboveLeft);
    isAboveRightAvail = (cuAboveRight == NULL) ? false : CU::isSameSlice(*cuCurr, *cuAboveRight);
    isBelowLeftAvail  = (cuBelowLeft == NULL)  ? false : CU::isSameSlice(*cuCurr, *cuBelowLeft);
    isBelowRightAvail = (cuBelowRight == NULL) ? false : CU::isSameSlice(*cuCurr, *cuBelowRight);
  }
  else
  {
    isLeftAvail       = (cuLeft != NULL);
    isAboveAvail      = (cuAbove != NULL);
    isRightAvail      = (cuRight != NULL);
    isBelowAvail      = (cuBelow != NULL);
    isAboveLeftAvail  = (cuAboveLeft != NULL);
    isAboveRightAvail = (cuAboveRight != NULL);
    isBelowLeftAvail  = (cuBelowLeft != NULL);
    isBelowRightAvail = (cuBelowRight != NULL);
  }
#else
  {
    //left
    isLeftAvail       = (cuLeft != NULL)       ? ( !CU::isSameSlice(*cuCurr, *cuLeft)       ? cuCurr->slice->getLFCrossSliceBoundaryFlag()       : true ) : false;

    //above
    isAboveAvail      = (cuAbove != NULL)      ? ( !CU::isSameSlice(*cuCurr, *cuAbove)      ? cuCurr->slice->getLFCrossSliceBoundaryFlag()       : true ) : false;

    //right
    isRightAvail      = (cuRight != NULL)      ? ( !CU::isSameSlice(*cuCurr, *cuRight)      ? cuRight->slice->getLFCrossSliceBoundaryFlag()      : true ) : false;

    //below
    isBelowAvail      = (cuBelow != NULL)      ? ( !CU::isSameSlice(*cuCurr, *cuBelow)      ? cuBelow->slice->getLFCrossSliceBoundaryFlag()      : true ) : false;

    //above-left
    isAboveLeftAvail  = (cuAboveLeft != NULL)  ? ( !CU::isSameSlice(*cuCurr, *cuAboveLeft)  ? cuCurr->slice->getLFCrossSliceBoundaryFlag()       : true ) : false;

    //below-right
    isBelowRightAvail = (cuBelowRight != NULL) ? ( !CU::isSameSlice(*cuCurr, *cuBelowRight) ? cuBelowRight->slice->getLFCrossSliceBoundaryFlag() : true ) : false;

    //above-right
    isAboveRightAvail = false;
    if (cuAboveRight != NULL)
    {
      const bool bLFCrossSliceBoundaryFlag = (cuCurr->slice->getSliceCurStartCtuTsAddr() > cuAboveRight->slice->getSliceCurStartCtuTsAddr()) ? cuCurr->slice->getLFCrossSliceBoundaryFlag() : cuAboveRight->slice->getLFCrossSliceBoundaryFlag();
      isAboveRightAvail = ( !CU::isSameSlice(*cuCurr, *cuAboveRight) ) ? bLFCrossSliceBoundaryFlag : true;
    }

    //below-left
    isBelowLeftAvail = false;
    if (cuBelowLeft != NULL)
    {
      const bool bLFCrossSliceBoundaryFlag = (cuCurr->slice->getSliceCurStartCtuTsAddr() > cuBelowLeft->slice->getSliceCurStartCtuTsAddr()) ? cuCurr->slice->getLFCrossSliceBoundaryFlag() : cuBelowLeft->slice->getLFCrossSliceBoundaryFlag();
      isBelowLeftAvail = ( !CU::isSameSlice(*cuCurr, *cuBelowLeft) ) ? bLFCrossSliceBoundaryFlag : true;
    }
  }
#endif

  // check cross tile flags
  const bool isLoopFilterAcrossTilePPS = cs.pps->getLoopFilterAcrossTilesEnabledFlag();
  if (!isLoopFilterAcrossTilePPS)
  {
    isLeftAvail       = (!isLeftAvail)       ? false : CU::isSameTile(*cuCurr, *cuLeft);
    isAboveAvail      = (!isAboveAvail)      ? false : CU::isSameTile(*cuCurr, *cuAbove);
    isRightAvail      = (!isRightAvail)      ? false : CU::isSameTile(*cuCurr, *cuRight);
    isBelowAvail      = (!isBelowAvail)      ? false : CU::isSameTile(*cuCurr, *cuBelow);
    isAboveLeftAvail  = (!isAboveLeftAvail)  ? false : CU::isSameTile(*cuCurr, *cuAboveLeft);
    isAboveRightAvail = (!isAboveRightAvail) ? false : CU::isSameTile(*cuCurr, *cuAboveRight);
    isBelowLeftAvail  = (!isBelowLeftAvail)  ? false : CU::isSameTile(*cuCurr, *cuBelowLeft);
    isBelowRightAvail = (!isBelowRightAvail) ? false : CU::isSameTile(*cuCurr, *cuBelowRight);
  }
}

#if JVET_P1006_PICTURE_HEADER
bool SampleAdaptiveOffset::isCrossedByVirtualBoundaries(const int xPos, const int yPos, const int width, const int height, int& numHorVirBndry, int& numVerVirBndry, int horVirBndryPos[], int verVirBndryPos[], const PicHeader* picHeader )
{
  numHorVirBndry = 0; numVerVirBndry = 0;
  if (picHeader->getLoopFilterAcrossVirtualBoundariesDisabledFlag())
  {
    for (int i = 0; i < picHeader->getNumHorVirtualBoundaries(); i++)
    {
     if (yPos <= picHeader->getVirtualBoundariesPosY(i) && picHeader->getVirtualBoundariesPosY(i) <= yPos + height)
      {
        horVirBndryPos[numHorVirBndry++] = picHeader->getVirtualBoundariesPosY(i);
      }
    }
    for (int i = 0; i < picHeader->getNumVerVirtualBoundaries(); i++)
    {
      if (xPos <= picHeader->getVirtualBoundariesPosX(i) && picHeader->getVirtualBoundariesPosX(i) <= xPos + width)
      {
        verVirBndryPos[numVerVirBndry++] = picHeader->getVirtualBoundariesPosX(i);
      }
    }
  }
  return numHorVirBndry > 0 || numVerVirBndry > 0 ;
}
#else
bool SampleAdaptiveOffset::isCrossedByVirtualBoundaries(const int xPos, const int yPos, const int width, const int height, int& numHorVirBndry, int& numVerVirBndry, int horVirBndryPos[], int verVirBndryPos[], const PPS* pps)
{
  numHorVirBndry = 0; numVerVirBndry = 0;
  if (pps->getLoopFilterAcrossVirtualBoundariesDisabledFlag())
  {
    for (int i = 0; i < pps->getNumHorVirtualBoundaries(); i++)
    {
     if (yPos <= pps->getVirtualBoundariesPosY(i) && pps->getVirtualBoundariesPosY(i) <= yPos + height)
      {
        horVirBndryPos[numHorVirBndry++] = pps->getVirtualBoundariesPosY(i);
      }
    }
    for (int i = 0; i < pps->getNumVerVirtualBoundaries(); i++)
    {
      if (xPos <= pps->getVirtualBoundariesPosX(i) && pps->getVirtualBoundariesPosX(i) <= xPos + width)
      {
        verVirBndryPos[numVerVirBndry++] = pps->getVirtualBoundariesPosX(i);
      }
    }
  }
  return numHorVirBndry > 0 || numVerVirBndry > 0 ;
}
#endif
//! \}