UnitTools.cpp

        int offset0 = (ui * 2) + mergeCandList.interDirNeighbours[ui] - 1;
        int offset1 = (mergeCandIndex * 2) + mergeCandList.interDirNeighbours[ui] - 1;
        if (mergeCandList.mvFieldNeighbours[offset0].refIdx == mergeCandList.mvFieldNeighbours[offset1].refIdx &&
            mergeCandList.mvFieldNeighbours[offset0].mv == mergeCandList.mvFieldNeighbours[offset1].mv
          )
        {
          hasPruned[ui] = true;
          return true;
        }
      }
    }
  }

  return false;
}

#if JVET_L0090_PAIR_AVG

bool PU::addMergeHMVPCand(const Slice &slice, MergeCtx& mrgCtx, bool canFastExit, const int& mrgCandIdx, const uint32_t maxNumMergeCandMin1, int &cnt, const int prevCnt, bool isAvailableSubPu, unsigned subPuMvpPos
#if JVET_M0483_IBC==0
  , int mmvdList
#endif
#if JVET_M0483_IBC
  , bool ibcFlag
#endif
#if JVET_M0170_MRG_SHARELIST
  , bool isShared
#endif
)
#else

bool PU::addMergeHMVPCand(const Slice &slice, MergeCtx& mrgCtx, bool isCandInter[MRG_MAX_NUM_CANDS], bool canFastExit, const int& mrgCandIdx, const uint32_t maxNumMergeCandMin1, int &cnt, const int prevCnt, bool isAvailableSubPu, unsigned subPuMvpPos
  , int mmvdList
)
#endif
{
#if JVET_M0483_IBC==0
  int mrgCandIdxIBC = mrgCandIdx;
#endif
  MotionInfo miNeighbor;
  bool hasPruned[MRG_MAX_NUM_CANDS];
  memset(hasPruned, 0, MRG_MAX_NUM_CANDS * sizeof(bool));
  if (isAvailableSubPu)
  {
    hasPruned[subPuMvpPos] = true;
  }
#if JVET_M0170_MRG_SHARELIST
#if JVET_M0483_IBC
  int num_avai_candInLUT = ibcFlag ? (isShared ? slice.getAvailableLUTBkupIBCMrgNum() : slice.getAvailableLUTIBCMrgNum()) : (isShared ? slice.getAvailableLUTBkupMrgNum() : slice.getAvailableLUTMrgNum());
  int offset = ibcFlag ? MAX_NUM_HMVP_CANDS : 0;
#else
  int num_avai_candInLUT = (isShared ? slice.getAvailableLUTBkupMrgNum() : slice.getAvailableLUTMrgNum());
#endif
#else
#if JVET_M0483_IBC
  int num_avai_candInLUT = ibcFlag ? slice.getAvailableLUTIBCMrgNum() : slice.getAvailableLUTMrgNum();
  int offset = ibcFlag ? MAX_NUM_HMVP_CANDS : 0;
#else
  int num_avai_candInLUT = slice.getAvailableLUTMrgNum();
#endif
#endif

  for (int mrgIdx = 1; mrgIdx <= num_avai_candInLUT; mrgIdx++)
  {
#if JVET_M0170_MRG_SHARELIST
#if JVET_M0483_IBC
    miNeighbor = ibcFlag ? (isShared ? slice.getMotionInfoFromLUTBkup(num_avai_candInLUT - mrgIdx + offset) : slice.getMotionInfoFromLUTs(num_avai_candInLUT - mrgIdx + offset))
      : (isShared ? slice.getMotionInfoFromLUTBkup(num_avai_candInLUT - mrgIdx) : slice.getMotionInfoFromLUTs(num_avai_candInLUT - mrgIdx));
#else
    miNeighbor = isShared ? slice.getMotionInfoFromLUTBkup(num_avai_candInLUT - mrgIdx) : slice.getMotionInfoFromLUTs(num_avai_candInLUT - mrgIdx);
#endif
#else
#if JVET_M0483_IBC
    miNeighbor = slice.getMotionInfoFromLUTs(num_avai_candInLUT - mrgIdx + offset);
#else
    miNeighbor = slice.getMotionInfoFromLUTs(num_avai_candInLUT - mrgIdx);
#endif
#endif
    mrgCtx.interDirNeighbours[cnt] = miNeighbor.interDir;
    mrgCtx.mvFieldNeighbours[cnt << 1].setMvField(miNeighbor.mv[0], miNeighbor.refIdx[0]);
    if (slice.isInterB())
    {
      mrgCtx.mvFieldNeighbours[(cnt << 1) + 1].setMvField(miNeighbor.mv[1], miNeighbor.refIdx[1]);
    }
#if JVET_M0126_HMVP_MRG_PRUNING
    if (mrgIdx > 2 || !xCheckSimilarMotion(cnt, prevCnt, mrgCtx, hasPruned))
#else
    if (!xCheckSimilarMotion(cnt, prevCnt, mrgCtx, hasPruned))
#endif
    {
#if !JVET_L0090_PAIR_AVG
      isCandInter[cnt] = true;
#endif
#if JVET_M0264_HMVP_WITH_GBIIDX
      mrgCtx.GBiIdx[cnt] = (mrgCtx.interDirNeighbours[cnt] == 3) ? miNeighbor.GBiIdx : GBI_DEFAULT;
#endif
#if JVET_M0483_IBC==0
      if (miNeighbor.interDir == 1 && slice.getRefPic(REF_PIC_LIST_0, miNeighbor.refIdx[0])->getPOC() == slice.getPOC())
      {
        mrgCtx.mrgTypeNeighbours[cnt] = MRG_TYPE_IBC;
        if(mmvdList != 0 && mrgCandIdx != -1)
          mrgCandIdxIBC++;
      }
      if (mrgCandIdxIBC == cnt && canFastExit)
#else
      if (mrgCandIdx == cnt && canFastExit)
#endif
      {
        return true;
      }
      cnt ++;
      if (cnt  == maxNumMergeCandMin1)
      {
        break;
      }
    }
  }
  return false;
}

#if JVET_M0483_IBC
void PU::getIBCMergeCandidates(const PredictionUnit &pu, MergeCtx& mrgCtx, const int& mrgCandIdx)
{
  const CodingStructure &cs = *pu.cs;
  const Slice &slice = *pu.cs->slice;
  const uint32_t maxNumMergeCand = slice.getMaxNumMergeCand();
  const bool canFastExit = pu.cs->pps->getLog2ParallelMergeLevelMinus2() == 0;

  for (uint32_t ui = 0; ui < maxNumMergeCand; ++ui)
  {
    mrgCtx.GBiIdx[ui] = GBI_DEFAULT;
    mrgCtx.interDirNeighbours[ui] = 0;
    mrgCtx.mrgTypeNeighbours[ui] = MRG_TYPE_IBC;
    mrgCtx.mvFieldNeighbours[ui * 2].refIdx = NOT_VALID;
    mrgCtx.mvFieldNeighbours[ui * 2 + 1].refIdx = NOT_VALID;
  }

  mrgCtx.numValidMergeCand = maxNumMergeCand;
  // compute the location of the current PU

  int cnt = 0;

#if JVET_M0170_MRG_SHARELIST
  const Position posLT = pu.shareParentPos;
  const Position posRT = pu.shareParentPos.offset(pu.shareParentSize.width - 1, 0);
  const Position posLB = pu.shareParentPos.offset(0, pu.shareParentSize.height - 1);
#else
  const Position posLT = pu.Y().topLeft();
  const Position posRT = pu.Y().topRight();
  const Position posLB = pu.Y().bottomLeft();
#endif

  MotionInfo miAbove, miLeft, miAboveLeft, miAboveRight, miBelowLeft;

  //left
  const PredictionUnit* puLeft = cs.getPURestricted(posLB.offset(-1, 0), pu, pu.chType);
  const bool isAvailableA1 = puLeft && isDiffMER(pu, *puLeft) && pu.cu != puLeft->cu && CU::isIBC(*puLeft->cu);
  if (isAvailableA1)
  {
    miLeft = puLeft->getMotionInfo(posLB.offset(-1, 0));

    // get Inter Dir
    mrgCtx.interDirNeighbours[cnt] = miLeft.interDir;
    // get Mv from Left
    mrgCtx.mvFieldNeighbours[cnt << 1].setMvField(miLeft.mv[0], miLeft.refIdx[0]);
    if (mrgCandIdx == cnt && canFastExit)
    {
      return;
    }
    cnt++;
  }

  // early termination
  if (cnt == maxNumMergeCand)
  {
    return;
  }


  // above
  const PredictionUnit *puAbove = cs.getPURestricted(posRT.offset(0, -1), pu, pu.chType);
  bool isAvailableB1 = puAbove && isDiffMER(pu, *puAbove) && pu.cu != puAbove->cu && CU::isIBC(*puAbove->cu);
  if (isAvailableB1)
  {
    miAbove = puAbove->getMotionInfo(posRT.offset(0, -1));

    if (!isAvailableA1 || (miAbove != miLeft))
    {
      // get Inter Dir
      mrgCtx.interDirNeighbours[cnt] = miAbove.interDir;
      // get Mv from Above
      mrgCtx.mvFieldNeighbours[cnt << 1].setMvField(miAbove.mv[0], miAbove.refIdx[0]);
      if (mrgCandIdx == cnt && canFastExit)
      {
        return;
      }

      cnt++;
    }
  }

  // early termination
  if (cnt == maxNumMergeCand)
  {
    return;
  }

#if JVET_M0126_HMVP_MRG_PRUNING
  int spatialCandPos = cnt;
#endif

  // above right
  const PredictionUnit *puAboveRight = cs.getPURestricted(posRT.offset(1, -1), pu, pu.chType);
  bool isAvailableB0 = puAboveRight && isDiffMER(pu, *puAboveRight) && CU::isIBC(*puAboveRight->cu);
  if (isAvailableB0)
  {
    miAboveRight = puAboveRight->getMotionInfo(posRT.offset(1, -1));

#if HM_JEM_MERGE_CANDS
    if ((!isAvailableB1 || (miAbove != miAboveRight)) && (!isAvailableA1 || (miLeft != miAboveRight)))
#else
    if (!isAvailableB1 || (miAbove != miAboveRight))
#endif
    {
      // get Inter Dir
      mrgCtx.interDirNeighbours[cnt] = miAboveRight.interDir;
      // get Mv from Above-right
      mrgCtx.mvFieldNeighbours[cnt << 1].setMvField(miAboveRight.mv[0], miAboveRight.refIdx[0]);

      if (mrgCandIdx == cnt && canFastExit)
      {
        return;
      }

      cnt++;
    }
  }
  // early termination
  if (cnt == maxNumMergeCand)
  {
    return;
  }

  //left bottom
  const PredictionUnit *puLeftBottom = cs.getPURestricted(posLB.offset(-1, 1), pu, pu.chType);
  bool isAvailableA0 = puLeftBottom && isDiffMER(pu, *puLeftBottom) && CU::isIBC(*puLeftBottom->cu);
  if (isAvailableA0)
  {
    miBelowLeft = puLeftBottom->getMotionInfo(posLB.offset(-1, 1));

#if HM_JEM_MERGE_CANDS
    if ((!isAvailableA1 || (miBelowLeft != miLeft)) && (!isAvailableB1 || (miBelowLeft != miAbove)) && (!isAvailableB0 || (miBelowLeft != miAboveRight)))
#else
    if (!isAvailableA1 || (miBelowLeft != miLeft))
#endif
    {
      // get Inter Dir
      mrgCtx.interDirNeighbours[cnt] = miBelowLeft.interDir;
      mrgCtx.mvFieldNeighbours[cnt << 1].setMvField(miBelowLeft.mv[0], miBelowLeft.refIdx[0]);
      if (mrgCandIdx == cnt && canFastExit)
      {
        return;
      }

      cnt++;
    }
  }
  // early termination
  if (cnt == maxNumMergeCand)
  {
    return;
  }

  // above left
  if (cnt < 4)
  {
    const PredictionUnit *puAboveLeft = cs.getPURestricted(posLT.offset(-1, -1), pu, pu.chType);
    bool isAvailableB2 = puAboveLeft && isDiffMER(pu, *puAboveLeft) && CU::isIBC(*puAboveLeft->cu);
    if (isAvailableB2)
    {
      miAboveLeft = puAboveLeft->getMotionInfo(posLT.offset(-1, -1));

#if HM_JEM_MERGE_CANDS
      if ((!isAvailableA1 || (miLeft != miAboveLeft)) && (!isAvailableB1 || (miAbove != miAboveLeft)) && (!isAvailableA0 || (miBelowLeft != miAboveLeft)) && (!isAvailableB0 || (miAboveRight != miAboveLeft)))
#else
      if ((!isAvailableA1 || (miLeft != miAboveLeft)) && (!isAvailableB1 || (miAbove != miAboveLeft)))
#endif
      {
        // get Inter Dir
        mrgCtx.interDirNeighbours[cnt] = miAboveLeft.interDir;
        mrgCtx.mvFieldNeighbours[cnt << 1].setMvField(miAboveLeft.mv[0], miAboveLeft.refIdx[0]);
        if (mrgCandIdx == cnt && canFastExit)
        {
          return;
        }

        cnt++;
      }
    }
  }
  // early termination
  if (cnt == maxNumMergeCand)
  {
    return;
  }

  int maxNumMergeCandMin1 = maxNumMergeCand - 1;
  if (cnt != maxNumMergeCandMin1)
  {
    bool isAvailableSubPu = false;
    unsigned subPuMvpPos = 0;

#if JVET_M0170_MRG_SHARELIST
    bool  isShared = ((pu.Y().lumaSize().width != pu.shareParentSize.width) || (pu.Y().lumaSize().height != pu.shareParentSize.height));
#endif

#if JVET_L0090_PAIR_AVG
    bool bFound = addMergeHMVPCand(slice, mrgCtx, canFastExit
      , mrgCandIdx
      , maxNumMergeCandMin1, cnt
#if JVET_M0126_HMVP_MRG_PRUNING
      , spatialCandPos
#else
      , cnt
#endif
      , isAvailableSubPu, subPuMvpPos
#if JVET_M0483_IBC
      , true
#endif
#if JVET_M0170_MRG_SHARELIST
      , isShared
#endif
    );
#else
    bool bFound = addMergeHMVPCand(slice, mrgCtx, isCandInter, canFastExit
      , mrgCandIdx
      , maxNumMergeCandMin1, cnt, cnt, isAvailableSubPu, subPuMvpPos
    );
#endif
    if (bFound)
    {
      return;
    }
  }

#if JVET_L0090_PAIR_AVG
  // pairwise-average candidates
#if JVET_M0193_PAIR_AVG_REDUCTION==0
    const int cutoff = std::min(cnt, 4);
    const int end = cutoff * (cutoff - 1) / 2;
    constexpr int PRIORITY_LIST0[] = { 0, 0, 1, 0, 1, 2 };
    constexpr int PRIORITY_LIST1[] = { 1, 2, 2, 3, 3, 3 };

    for (int idx = 0; idx < end && cnt != maxNumMergeCand; idx++)
    {
      const int i = PRIORITY_LIST0[idx];
      const int j = PRIORITY_LIST1[idx];
#else
    if (cnt>1 && cnt <maxNumMergeCand)
    {
#endif
       mrgCtx.mvFieldNeighbours[cnt * 2    ].setMvField(Mv(0, 0), NOT_VALID);
       mrgCtx.mvFieldNeighbours[cnt * 2 + 1].setMvField(Mv(0, 0), NOT_VALID);

#if JVET_M0193_PAIR_AVG_REDUCTION
       const Mv& MvI = mrgCtx.mvFieldNeighbours[0 * 2].mv;
       const Mv& MvJ = mrgCtx.mvFieldNeighbours[1 * 2].mv;
#else
       const Mv& MvI = mrgCtx.mvFieldNeighbours[i * 2 ].mv;
       const Mv& MvJ = mrgCtx.mvFieldNeighbours[j * 2 ].mv;
#endif
       // average two MVs
       Mv avgMv = MvI;

       avgMv += MvJ;
       mrgCtx.mrgTypeNeighbours[cnt] = MRG_TYPE_IBC;
#if JVET_M0265_MV_ROUNDING_CLEANUP
       roundAffineMv(avgMv.hor, avgMv.ver, 1);
       avgMv.roundToPrecision(MV_PRECISION_INTERNAL, MV_PRECISION_INT);
#else
       avgMv.setHor(avgMv.getHor() / 2);
       avgMv.setVer(avgMv.getVer() / 2);
       avgMv.setHor((avgMv.getHor() / 16) << 4);
       avgMv.setVer((avgMv.getVer() / 16) << 4);
#endif
      mrgCtx.mvFieldNeighbours[cnt * 2 ].setMvField(avgMv, MAX_NUM_REF);
      mrgCtx.interDirNeighbours[cnt] = 1;
      cnt++;
    }

    // early termination
    if (cnt == maxNumMergeCand)
    {
      return;
    }
#endif

  mrgCtx.numValidMergeCand = cnt;

}
#endif

void PU::getInterMergeCandidates( const PredictionUnit &pu, MergeCtx& mrgCtx,
                                 int mmvdList,
                                 const int& mrgCandIdx )
{
  const CodingStructure &cs  = *pu.cs;
  const Slice &slice         = *pu.cs->slice;
  const uint32_t maxNumMergeCand = slice.getMaxNumMergeCand();
  const bool canFastExit     = pu.cs->pps->getLog2ParallelMergeLevelMinus2() == 0;

#if !JVET_L0090_PAIR_AVG
  // this variable is unused if remove HEVC combined candidates
  bool isCandInter[MRG_MAX_NUM_CANDS];
#endif

  for (uint32_t ui = 0; ui < maxNumMergeCand; ++ui)
  {
#if !JVET_L0090_PAIR_AVG
    isCandInter[ui] = false;
#endif
    mrgCtx.GBiIdx[ui] = GBI_DEFAULT;
    mrgCtx.interDirNeighbours[ui] = 0;
    mrgCtx.mrgTypeNeighbours [ui] = MRG_TYPE_DEFAULT_N;
    mrgCtx.mvFieldNeighbours[(ui << 1)    ].refIdx = NOT_VALID;
    mrgCtx.mvFieldNeighbours[(ui << 1) + 1].refIdx = NOT_VALID;
  }

  mrgCtx.numValidMergeCand = maxNumMergeCand;
  // compute the location of the current PU

  int cnt = 0;

#if JVET_M0483_IBC==0
  int mrgCandIdxIBC = mrgCandIdx;
#endif

#if JVET_M0170_MRG_SHARELIST
  const Position posLT = pu.shareParentPos;
  const Position posRT = pu.shareParentPos.offset(pu.shareParentSize.width - 1, 0);
  const Position posLB = pu.shareParentPos.offset(0, pu.shareParentSize.height - 1);
#else
  const Position posLT = pu.Y().topLeft();
  const Position posRT = pu.Y().topRight();
  const Position posLB = pu.Y().bottomLeft();
#endif
  MotionInfo miAbove, miLeft, miAboveLeft, miAboveRight, miBelowLeft;

  //left
  const PredictionUnit* puLeft = cs.getPURestricted( posLB.offset( -1, 0 ), pu, pu.chType );

  const bool isAvailableA1 = puLeft && isDiffMER( pu, *puLeft ) && pu.cu != puLeft->cu && CU::isInter( *puLeft->cu );

  if( isAvailableA1 )
  {
    miLeft = puLeft->getMotionInfo( posLB.offset(-1, 0) );

#if !JVET_L0090_PAIR_AVG
    isCandInter[cnt] = true;
#endif

    // get Inter Dir
    mrgCtx.interDirNeighbours[cnt] = miLeft.interDir;
    mrgCtx.GBiIdx[cnt] = (mrgCtx.interDirNeighbours[cnt] == 3) ? puLeft->cu->GBiIdx : GBI_DEFAULT;
    // get Mv from Left
#if JVET_M0483_IBC==0
    if (puLeft->cu->ibc)
    {
      mrgCtx.mrgTypeNeighbours[cnt] = MRG_TYPE_IBC;
      if (mmvdList != 0 && mrgCandIdx != -1)
        mrgCandIdxIBC++;
    }
#endif
    mrgCtx.mvFieldNeighbours[cnt << 1].setMvField(miLeft.mv[0], miLeft.refIdx[0]);

    if (slice.isInterB())
    {
      mrgCtx.mvFieldNeighbours[(cnt << 1) + 1].setMvField(miLeft.mv[1], miLeft.refIdx[1]);
    }
#if JVET_M0483_IBC==0
    if (mrgCandIdxIBC == cnt && canFastExit)
#else
    if (mrgCandIdx == cnt && canFastExit)
#endif
    {
      return;
    }

    cnt++;
  }

  // early termination
  if (cnt == maxNumMergeCand)
  {
    return;
  }


  // above
  const PredictionUnit *puAbove = cs.getPURestricted( posRT.offset( 0, -1 ), pu, pu.chType );

  bool isAvailableB1 = puAbove && isDiffMER( pu, *puAbove ) && pu.cu != puAbove->cu && CU::isInter( *puAbove->cu );

  if( isAvailableB1 )
  {
    miAbove = puAbove->getMotionInfo( posRT.offset( 0, -1 ) );

    if( !isAvailableA1 || ( miAbove != miLeft ) )
    {
#if !JVET_L0090_PAIR_AVG
      isCandInter[cnt] = true;
#endif

      // get Inter Dir
      mrgCtx.interDirNeighbours[cnt] = miAbove.interDir;
      // get Mv from Above
      mrgCtx.GBiIdx[cnt] = (mrgCtx.interDirNeighbours[cnt] == 3) ? puAbove->cu->GBiIdx : GBI_DEFAULT;
#if JVET_M0483_IBC==0
      if (puAbove->cu->ibc)
      {
        mrgCtx.mrgTypeNeighbours[cnt] = MRG_TYPE_IBC;
        if (mmvdList != 0 && mrgCandIdx != -1)
          mrgCandIdxIBC++;
      }
#endif
      mrgCtx.mvFieldNeighbours[cnt << 1].setMvField( miAbove.mv[0], miAbove.refIdx[0] );

      if( slice.isInterB() )
      {
        mrgCtx.mvFieldNeighbours[( cnt << 1 ) + 1].setMvField( miAbove.mv[1], miAbove.refIdx[1] );
      }
#if JVET_M0483_IBC==0
      if (mrgCandIdxIBC == cnt && canFastExit)
#else
      if (mrgCandIdx == cnt && canFastExit)
#endif
      {
        return;
      }

      cnt++;
    }
  }

  // early termination
  if( cnt == maxNumMergeCand )
  {
    return;
  }

#if JVET_M0126_HMVP_MRG_PRUNING
  int spatialCandPos = cnt;
#endif

  // above right
  const PredictionUnit *puAboveRight = cs.getPURestricted( posRT.offset( 1, -1 ), pu, pu.chType );

  bool isAvailableB0 = puAboveRight && isDiffMER( pu, *puAboveRight ) && CU::isInter( *puAboveRight->cu );

  if( isAvailableB0 )
  {
    miAboveRight = puAboveRight->getMotionInfo( posRT.offset( 1, -1 ) );

#if HM_JEM_MERGE_CANDS
    if( ( !isAvailableB1 || ( miAbove != miAboveRight ) ) && ( !isAvailableA1 || ( miLeft != miAboveRight ) ) )
#else
    if( !isAvailableB1 || ( miAbove != miAboveRight ) )
#endif
    {
#if !JVET_L0090_PAIR_AVG
      isCandInter[cnt] = true;
#endif

      // get Inter Dir
      mrgCtx.interDirNeighbours[cnt] = miAboveRight.interDir;
      // get Mv from Above-right
      mrgCtx.GBiIdx[cnt] = (mrgCtx.interDirNeighbours[cnt] == 3) ? puAboveRight->cu->GBiIdx : GBI_DEFAULT;
#if JVET_M0483_IBC==0
      if (puAboveRight->cu->ibc)
      {
        mrgCtx.mrgTypeNeighbours[cnt] = MRG_TYPE_IBC;
        if (mmvdList != 0 && mrgCandIdx != -1)
          mrgCandIdxIBC++;
      }
#endif
      mrgCtx.mvFieldNeighbours[cnt << 1].setMvField( miAboveRight.mv[0], miAboveRight.refIdx[0] );

      if( slice.isInterB() )
      {
        mrgCtx.mvFieldNeighbours[( cnt << 1 ) + 1].setMvField( miAboveRight.mv[1], miAboveRight.refIdx[1] );
      }

#if JVET_M0483_IBC==0
      if (mrgCandIdxIBC == cnt && canFastExit)
#else
      if (mrgCandIdx == cnt && canFastExit)
#endif
      {
        return;
      }

      cnt++;
    }
  }
  // early termination
  if( cnt == maxNumMergeCand )
  {
    return;
  }

  //left bottom
  const PredictionUnit *puLeftBottom = cs.getPURestricted( posLB.offset( -1, 1 ), pu, pu.chType );

  bool isAvailableA0 = puLeftBottom && isDiffMER( pu, *puLeftBottom ) && CU::isInter( *puLeftBottom->cu );

  if( isAvailableA0 )
  {
    miBelowLeft = puLeftBottom->getMotionInfo( posLB.offset( -1, 1 ) );

#if HM_JEM_MERGE_CANDS
    if( ( !isAvailableA1 || ( miBelowLeft != miLeft ) ) && ( !isAvailableB1 || ( miBelowLeft != miAbove ) ) && ( !isAvailableB0 || ( miBelowLeft != miAboveRight ) ) )
#else
    if( !isAvailableA1 || ( miBelowLeft != miLeft ) )
#endif
    {
#if !JVET_L0090_PAIR_AVG
      isCandInter[cnt] = true;
#endif

      // get Inter Dir
      mrgCtx.interDirNeighbours[cnt] = miBelowLeft.interDir;
      mrgCtx.GBiIdx[cnt] = (mrgCtx.interDirNeighbours[cnt] == 3) ? puLeftBottom->cu->GBiIdx : GBI_DEFAULT;
      // get Mv from Bottom-Left
#if JVET_M0483_IBC==0
      if (puLeftBottom->cu->ibc)
      {
        mrgCtx.mrgTypeNeighbours[cnt] = MRG_TYPE_IBC;
        if (mmvdList != 0 && mrgCandIdx != -1)
          mrgCandIdxIBC++;
      }
#endif
      mrgCtx.mvFieldNeighbours[cnt << 1].setMvField( miBelowLeft.mv[0], miBelowLeft.refIdx[0] );

      if( slice.isInterB() )
      {
        mrgCtx.mvFieldNeighbours[( cnt << 1 ) + 1].setMvField( miBelowLeft.mv[1], miBelowLeft.refIdx[1] );
      }

#if JVET_M0483_IBC==0
      if (mrgCandIdxIBC == cnt && canFastExit)
#else
      if (mrgCandIdx == cnt && canFastExit)
#endif
      {
        return;
      }

      cnt++;
    }
  }
  // early termination
  if( cnt == maxNumMergeCand )
  {
    return;
  }


  // above left
  if ( cnt < 4 )
  {
    const PredictionUnit *puAboveLeft = cs.getPURestricted( posLT.offset( -1, -1 ), pu, pu.chType );

    bool isAvailableB2 = puAboveLeft && isDiffMER( pu, *puAboveLeft ) && CU::isInter( *puAboveLeft->cu );

    if( isAvailableB2 )
    {
      miAboveLeft = puAboveLeft->getMotionInfo( posLT.offset( -1, -1 ) );

#if HM_JEM_MERGE_CANDS
      if( ( !isAvailableA1 || ( miLeft != miAboveLeft ) ) && ( !isAvailableB1 || ( miAbove != miAboveLeft ) ) && ( !isAvailableA0 || ( miBelowLeft != miAboveLeft ) ) && ( !isAvailableB0 || ( miAboveRight != miAboveLeft ) ) )
#else
      if( ( !isAvailableA1 || ( miLeft != miAboveLeft ) ) && ( !isAvailableB1 || ( miAbove != miAboveLeft ) ) )
#endif
      {
#if !JVET_L0090_PAIR_AVG
        isCandInter[cnt] = true;
#endif

        // get Inter Dir
        mrgCtx.interDirNeighbours[cnt] = miAboveLeft.interDir;
        mrgCtx.GBiIdx[cnt] = (mrgCtx.interDirNeighbours[cnt] == 3) ? puAboveLeft->cu->GBiIdx : GBI_DEFAULT;
        // get Mv from Above-Left
#if JVET_M0483_IBC==0
        if (puAboveLeft->cu->ibc)
        {
          mrgCtx.mrgTypeNeighbours[cnt] = MRG_TYPE_IBC;
          if (mmvdList != 0 && mrgCandIdx != -1)
            mrgCandIdxIBC++;
        }
#endif
        mrgCtx.mvFieldNeighbours[cnt << 1].setMvField( miAboveLeft.mv[0], miAboveLeft.refIdx[0] );

        if( slice.isInterB() )
        {
          mrgCtx.mvFieldNeighbours[( cnt << 1 ) + 1].setMvField( miAboveLeft.mv[1], miAboveLeft.refIdx[1] );
        }

#if JVET_M0483_IBC==0
        if (mrgCandIdxIBC == cnt && canFastExit)
#else
        if (mrgCandIdx == cnt && canFastExit)
#endif
        {
          return;
        }

        cnt++;
      }
    }
  }
  // early termination
  if (cnt == maxNumMergeCand)
  {
    return;
  }

  if (slice.getEnableTMVPFlag())
  {
    //>> MTK colocated-RightBottom
    // offset the pos to be sure to "point" to the same position the uiAbsPartIdx would've pointed to
#if JVET_M0170_MRG_SHARELIST
    Position posRB = pu.shareParentPos.offset(pu.shareParentSize.width-3, pu.shareParentSize.height - 3);
#else
    Position posRB = pu.Y().bottomRight().offset(-3, -3);
#endif
    const PreCalcValues& pcv = *cs.pcv;

    Position posC0;
#if JVET_M0170_MRG_SHARELIST
    Position posC1 = pu.shareParentPos.offset((pu.shareParentSize.width/2), (pu.shareParentSize.height/2));
#else
    Position posC1 = pu.Y().center();
#endif

    bool C0Avail = false;
#if JVET_M0170_MRG_SHARELIST
    bool C1Avail = (posC1.x < pcv.lumaWidth) && (posC1.y  < pcv.lumaHeight);
#endif

    if (((posRB.x + pcv.minCUWidth) < pcv.lumaWidth) && ((posRB.y + pcv.minCUHeight) < pcv.lumaHeight))
    {
      {
        Position posInCtu( posRB.x & pcv.maxCUWidthMask, posRB.y & pcv.maxCUHeightMask );

        if( ( posInCtu.x + 4 < pcv.maxCUWidth ) &&           // is not at the last column of CTU
            ( posInCtu.y + 4 < pcv.maxCUHeight ) )           // is not at the last row    of CTU
        {
          posC0 = posRB.offset( 4, 4 );
          C0Avail = true;
        }
        else if( posInCtu.x + 4 < pcv.maxCUWidth )           // is not at the last column of CTU But is last row of CTU
        {
          posC0 = posRB.offset( 4, 4 );
          // in the reference the CTU address is not set - thus probably resulting in no using this C0 possibility
        }
        else if( posInCtu.y + 4 < pcv.maxCUHeight )          // is not at the last row of CTU But is last column of CTU
        {
          posC0 = posRB.offset( 4, 4 );
          C0Avail = true;
        }
        else //is the right bottom corner of CTU
        {
          posC0 = posRB.offset( 4, 4 );
          // same as for last column but not last row
        }
      }
    }

    Mv        cColMv;
    int       iRefIdx     = 0;
    int       dir         = 0;
    unsigned  uiArrayAddr = cnt;
    bool      bExistMV    = ( C0Avail && getColocatedMVP(pu, REF_PIC_LIST_0, posC0, cColMv, iRefIdx ) )
#if JVET_M0170_MRG_SHARELIST
                                      || ( C1Avail && getColocatedMVP(pu, REF_PIC_LIST_0, posC1, cColMv, iRefIdx ));
#else
                                      || getColocatedMVP(pu, REF_PIC_LIST_0, posC1, cColMv, iRefIdx );
#endif

    if (bExistMV)
    {
      dir     |= 1;
      mrgCtx.mvFieldNeighbours[2 * uiArrayAddr].setMvField(cColMv, iRefIdx);
    }

    if (slice.isInterB())
    {
      bExistMV = ( C0Avail && getColocatedMVP(pu, REF_PIC_LIST_1, posC0, cColMv, iRefIdx ) )
#if JVET_M0170_MRG_SHARELIST
                           || (C1Avail &&  getColocatedMVP(pu, REF_PIC_LIST_1, posC1, cColMv, iRefIdx ) );
#else
                           || getColocatedMVP(pu, REF_PIC_LIST_1, posC1, cColMv, iRefIdx );
#endif
      if (bExistMV)
      {
        dir     |= 2;
        mrgCtx.mvFieldNeighbours[2 * uiArrayAddr + 1].setMvField(cColMv, iRefIdx);
      }
    }

    if( dir != 0 )
    {
      bool addTMvp = true;
#if HM_JEM_MERGE_CANDS
      int iSpanCand = cnt;
      for( int i = 0; i < iSpanCand; i++ )
      {
        if( mrgCtx.interDirNeighbours[  i           ] == dir &&
            mrgCtx.mvFieldNeighbours [  i << 1      ] == mrgCtx.mvFieldNeighbours[  uiArrayAddr << 1      ] &&
            mrgCtx.mvFieldNeighbours [( i << 1 ) + 1] == mrgCtx.mvFieldNeighbours[( uiArrayAddr << 1 ) + 1] )
        {
          addTMvp = false;
        }
      }
#endif
      if( addTMvp )
      {
        mrgCtx.interDirNeighbours[uiArrayAddr] = dir;
#if !JVET_L0090_PAIR_AVG
        isCandInter              [uiArrayAddr] = true;
#endif
        mrgCtx.GBiIdx[uiArrayAddr] = GBI_DEFAULT;
#if JVET_M0483_IBC==0
        if (mrgCandIdxIBC == cnt && canFastExit)
#else
        if (mrgCandIdx == cnt && canFastExit)
#endif
        {
          return;
        }

        cnt++;
      }
    }
  }

  // early termination
  if (cnt == maxNumMergeCand)
  {
    return;
  }

  int maxNumMergeCandMin1 = maxNumMergeCand - 1;
  if (cnt != maxNumMergeCandMin1)
  {
    bool isAvailableSubPu = false;
    unsigned subPuMvpPos = 0;
#if JVET_L0090_PAIR_AVG
#if JVET_M0170_MRG_SHARELIST
    bool  isShared = ((pu.Y().lumaSize().width != pu.shareParentSize.width) || (pu.Y().lumaSize().height != pu.shareParentSize.height));
#endif
    bool bFound = addMergeHMVPCand(slice, mrgCtx, canFastExit
#if JVET_M0483_IBC==0
      , (mmvdList != 0 && mrgCandIdx != -1) ? (const int) mrgCandIdxIBC : mrgCandIdx
#else
      , mrgCandIdx
#endif
      , maxNumMergeCandMin1, cnt
#if JVET_M0126_HMVP_MRG_PRUNING
      , spatialCandPos
#else
      , cnt
#endif
      , isAvailableSubPu, subPuMvpPos
#if JVET_M0483_IBC==0
      , mmvdList
#endif
#if JVET_M0483_IBC
      , CU::isIBC(*pu.cu)
#endif
#if JVET_M0170_MRG_SHARELIST
      , isShared
#endif
    );
#else
    bool bFound = addMergeHMVPCand(slice, mrgCtx, isCandInter, canFastExit
      , (mmvdList != 0 && mrgCandIdx != -1) ? (const int)mrgCandIdxIBC : mrgCandIdx
      , maxNumMergeCandMin1, cnt, cnt, isAvailableSubPu, subPuMvpPos
      , mmvdList
    );
#endif
    if (bFound)
    {
      return;
    }
  }

#if JVET_L0090_PAIR_AVG
  // pairwise-average candidates
  {
#if !JVET_M0193_PAIR_AVG_REDUCTION
    const int cutoff = std::min( cnt, 4 );
    const int end = cutoff * (cutoff - 1) / 2;
    constexpr int PRIORITY_LIST0[] = { 0, 0, 1, 0, 1, 2 };
    constexpr int PRIORITY_LIST1[] = { 1, 2, 2, 3, 3, 3 };
#endif

#if JVET_M0193_PAIR_AVG_REDUCTION
#if JVET_M0483_IBC
    if (cnt > 1 && cnt < maxNumMergeCand)
#else
    // skip when only 1 candidate is added so far or one is BV and one is MV
    if( cnt > 1 && cnt < maxNumMergeCand && !(mrgCtx.mrgTypeNeighbours[0] != mrgCtx.mrgTypeNeighbours[1] && pu.cs->sps->getIBCMode()))
#endif
#else
    for( int idx = 0; idx < end && cnt != maxNumMergeCand; idx++ )
#endif
    {
#if !JVET_M0193_PAIR_AVG_REDUCTION
      const int i = PRIORITY_LIST0[idx];
      const int j = PRIORITY_LIST1[idx];
#endif

      mrgCtx.mvFieldNeighbours[cnt * 2].setMvField( Mv( 0, 0 ), NOT_VALID );
      mrgCtx.mvFieldNeighbours[cnt * 2 + 1].setMvField( Mv( 0, 0 ), NOT_VALID );
      // calculate average MV for L0 and L1 seperately
      unsigned char interDir = 0;


#if !JVET_M0193_PAIR_AVG_REDUCTION && JVET_M0483_IBC==0
      // skip when one is BV and one is MV
      if (mrgCtx.mrgTypeNeighbours[i] != mrgCtx.mrgTypeNeighbours[j] && pu.cs->sps->getIBCMode())
      {
        continue;
      }
#endif
      for( int refListId = 0; refListId < (slice.isInterB() ? 2 : 1); refListId++ )
      {
#if JVET_M0193_PAIR_AVG_REDUCTION
        const short refIdxI = mrgCtx.mvFieldNeighbours[0 * 2 + refListId].refIdx;
        const short refIdxJ = mrgCtx.mvFieldNeighbours[1 * 2 + refListId].refIdx;
#else
        const short refIdxI = mrgCtx.mvFieldNeighbours[i * 2 + refListId].refIdx;
        const short refIdxJ = mrgCtx.mvFieldNeighbours[j * 2 + refListId].refIdx;
#endif

        // both MVs are invalid, skip
        if( (refIdxI == NOT_VALID) && (refIdxJ == NOT_VALID) )
        {
          continue;
        }

        interDir += 1 << refListId;
        // both MVs are valid, average these two MVs
        if( (refIdxI != NOT_VALID) && (refIdxJ != NOT_VALID) )
        {
#if JVET_M0193_PAIR_AVG_REDUCTION
          const Mv& MvI = mrgCtx.mvFieldNeighbours[0 * 2 + refListId].mv;
          const Mv& MvJ = mrgCtx.mvFieldNeighbours[1 * 2 + refListId].mv;
#else
          const Mv& MvI = mrgCtx.mvFieldNeighbours[i * 2 + refListId].mv;
          const Mv& MvJ = mrgCtx.mvFieldNeighbours[j * 2 + refListId].mv;
#endif

          // average two MVs
          Mv avgMv = MvI;
          avgMv += MvJ;
#if JVET_M0265_MV_ROUNDING_CLEANUP
          roundAffineMv(avgMv.hor, avgMv.ver, 1);
#else
          avgMv.setHor( avgMv.getHor() / 2 );
          avgMv.setVer( avgMv.getVer() / 2 );
#endif

#if JVET_M0483_IBC==0
#if JVET_M0193_PAIR_AVG_REDUCTION
          if (mrgCtx.mrgTypeNeighbours[0] == MRG_TYPE_IBC && mrgCtx.mrgTypeNeighbours[1] == MRG_TYPE_IBC && pu.cs->sps->getIBCMode())
#else
          if (mrgCtx.mrgTypeNeighbours[i] == MRG_TYPE_IBC && mrgCtx.mrgTypeNeighbours[j] == MRG_TYPE_IBC && pu.cs->sps->getIBCMode())
#endif
          {
             mrgCtx.mrgTypeNeighbours[cnt] = MRG_TYPE_IBC;
             avgMv.setHor((avgMv.getHor() / 16) << 4);
             avgMv.setVer((avgMv.getVer() / 16) << 4);
          }
#endif
          mrgCtx.mvFieldNeighbours[cnt * 2 + refListId].setMvField( avgMv, refIdxI );
        }
        // only one MV is valid, take the only one MV
        else if( refIdxI != NOT_VALID )
        {
#if JVET_M0193_PAIR_AVG_REDUCTION
          Mv singleMv = mrgCtx.mvFieldNeighbours[0 * 2 + refListId].mv;
#else
          Mv singleMv = mrgCtx.mvFieldNeighbours[i * 2 + refListId].mv;
#endif
          mrgCtx.mvFieldNeighbours[cnt * 2 + refListId].setMvField( singleMv, refIdxI );
        }
        else if( refIdxJ != NOT_VALID )
        {