UnitTools.cpp

    bool bFound = addMergeHMVPCand(slice, mrgCtx, canFastExit
      , mrgCandIdx
      , maxNumMergeCandMin1, cnt, cnt, isAvailableSubPu, subPuMvpPos
#if JVET_M0483_IBC
      , true
#endif
#if JVET_M0170_MRG_SHARELIST
      , false
#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
  {
    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];

      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;

      for (int refListId = 0; refListId < 1; refListId++)
      {
        const short refIdxI = mrgCtx.mvFieldNeighbours[i * 2 + refListId].refIdx;
        const short refIdxJ = mrgCtx.mvFieldNeighbours[j * 2 + refListId].refIdx;

        // 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))
        {
          const Mv& MvI = mrgCtx.mvFieldNeighbours[i * 2 + refListId].mv;
          const Mv& MvJ = mrgCtx.mvFieldNeighbours[j * 2 + refListId].mv;

          // average two MVs
          Mv avgMv = MvI;

          avgMv += MvJ;
          mrgCtx.mrgTypeNeighbours[cnt] = MRG_TYPE_IBC;
          avgMv.setHor(avgMv.getHor() / 2);
          avgMv.setVer(avgMv.getVer() / 2);
          avgMv.setHor((avgMv.getHor() / 16) << 4);
          avgMv.setVer((avgMv.getVer() / 16) << 4);
          mrgCtx.mvFieldNeighbours[cnt * 2 + refListId].setMvField(avgMv, refIdxI);
        }
      }
      mrgCtx.interDirNeighbours[cnt] = interDir;
      if (interDir > 0)
      {
        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 );

#if JVET_M0483_IBC
  const bool isAvailableA1 = puLeft && isDiffMER(pu, *puLeft) && pu.cu != puLeft->cu && (puLeft->cu->predMode == pu.cu->predMode);
#else
  const bool isAvailableA1 = puLeft && isDiffMER( pu, *puLeft ) && pu.cu != puLeft->cu && CU::isInter( *puLeft->cu );
#endif

  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 );

#if JVET_M0483_IBC
  bool isAvailableB1 = puAbove && isDiffMER(pu, *puAbove) && pu.cu != puAbove->cu && puAbove->cu->predMode == pu.cu->predMode;
#else
  bool isAvailableB1 = puAbove && isDiffMER( pu, *puAbove ) && pu.cu != puAbove->cu && CU::isInter( *puAbove->cu );
#endif

  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;
  }

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

#if JVET_M0483_IBC
  bool isAvailableB0 = puAboveRight && isDiffMER(pu, *puAboveRight) && (puAboveRight->cu->predMode == pu.cu->predMode);
#else
  bool isAvailableB0 = puAboveRight && isDiffMER( pu, *puAboveRight ) && CU::isInter( *puAboveRight->cu );
#endif

  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 );

#if JVET_M0483_IBC
  bool isAvailableA0 = puLeftBottom && isDiffMER(pu, *puLeftBottom) && (puLeftBottom->cu->predMode == pu.cu->predMode);
#else
  bool isAvailableA0 = puLeftBottom && isDiffMER( pu, *puLeftBottom ) && CU::isInter( *puLeftBottom->cu );
#endif

  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 );

#if JVET_M0483_IBC
    bool isAvailableB2 = puAboveLeft && isDiffMER(pu, *puAboveLeft) && (puAboveLeft->cu->predMode == pu.cu->predMode);
#else
    bool isAvailableB2 = puAboveLeft && isDiffMER( pu, *puAboveLeft ) && CU::isInter( *puAboveLeft->cu );
#endif

    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 )
    {
#if JVET_M0483_IBC
      bool addTMvp = !CU::isIBC(*pu.cu);
#else
      bool addTMvp = true;
#endif
#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, cnt, 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
    // 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->getSpsNext().getIBCMode()))
#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
      // skip when one is BV and one is MV
      if (mrgCtx.mrgTypeNeighbours[i] != mrgCtx.mrgTypeNeighbours[j] && pu.cs->sps->getSpsNext().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_M0193_PAIR_AVG_REDUCTION
          if (mrgCtx.mrgTypeNeighbours[0] == MRG_TYPE_IBC && mrgCtx.mrgTypeNeighbours[1] == MRG_TYPE_IBC && pu.cs->sps->getSpsNext().getIBCMode())
#else
          if (mrgCtx.mrgTypeNeighbours[i] == MRG_TYPE_IBC && mrgCtx.mrgTypeNeighbours[j] == MRG_TYPE_IBC && pu.cs->sps->getSpsNext().getIBCMode())
#endif
          {
             mrgCtx.mrgTypeNeighbours[cnt] = MRG_TYPE_IBC;
             avgMv.setHor((avgMv.getHor() / 16) << 4);
             avgMv.setVer((avgMv.getVer() / 16) << 4);
          }

          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 )
        {
#if JVET_M0193_PAIR_AVG_REDUCTION
          Mv singleMv = mrgCtx.mvFieldNeighbours[1 * 2 + refListId].mv;
#else
          Mv singleMv = mrgCtx.mvFieldNeighbours[j * 2 + refListId].mv;
#endif
          mrgCtx.mvFieldNeighbours[cnt * 2 + refListId].setMvField( singleMv, refIdxJ );
        }
      }

      mrgCtx.interDirNeighbours[cnt] = interDir;
      if( interDir > 0 )
      {
        cnt++;
      }
    }

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

  uint32_t uiArrayAddr = cnt;
#if !JVET_L0090_PAIR_AVG
  uint32_t uiCutoff    = std::min( uiArrayAddr, 3u );
  if (slice.isInterB())
  {
    static const uint32_t NUM_PRIORITY_LIST = 12;
    static const uint32_t uiPriorityList0[NUM_PRIORITY_LIST] = { 0 , 1, 0, 2, 1, 2, 0, 3, 1, 3, 2, 3 };
    static const uint32_t uiPriorityList1[NUM_PRIORITY_LIST] = { 1 , 0, 2, 0, 2, 1, 3, 0, 3, 1, 3, 2 };

    for (int idx = 0; idx < uiCutoff * (uiCutoff - 1) && uiArrayAddr != maxNumMergeCand; idx++)
    {
      CHECK( idx >= NUM_PRIORITY_LIST, "Invalid priority list number" );
      int i = uiPriorityList0[idx];
      int j = uiPriorityList1[idx];
      if (isCandInter[i] && isCandInter[j] && (mrgCtx.interDirNeighbours[i] & 0x1) && (mrgCtx.interDirNeighbours[j] & 0x2))
      {
        isCandInter[uiArrayAddr] = true;
        mrgCtx.interDirNeighbours[uiArrayAddr] = 3;
        mrgCtx.GBiIdx[uiArrayAddr] = ((mrgCtx.interDirNeighbours[uiArrayAddr] == 3)) ? CU::deriveGbiIdx(mrgCtx.GBiIdx[i], mrgCtx.GBiIdx[j]) : GBI_DEFAULT;

        // get Mv from cand[i] and cand[j]
        mrgCtx.mvFieldNeighbours[ uiArrayAddr << 1     ].setMvField(mrgCtx.mvFieldNeighbours[ i << 1     ].mv, mrgCtx.mvFieldNeighbours[ i << 1     ].refIdx);
        mrgCtx.mvFieldNeighbours[(uiArrayAddr << 1) + 1].setMvField(mrgCtx.mvFieldNeighbours[(j << 1) + 1].mv, mrgCtx.mvFieldNeighbours[(j << 1) + 1].refIdx);

        int iRefPOCL0 = slice.getRefPOC(REF_PIC_LIST_0, mrgCtx.mvFieldNeighbours[(uiArrayAddr << 1)    ].refIdx);
        int iRefPOCL1 = slice.getRefPOC(REF_PIC_LIST_1, mrgCtx.mvFieldNeighbours[(uiArrayAddr << 1) + 1].refIdx);

        if( iRefPOCL0 == iRefPOCL1 && mrgCtx.mvFieldNeighbours[( uiArrayAddr << 1 )].mv == mrgCtx.mvFieldNeighbours[( uiArrayAddr << 1 ) + 1].mv )
        {
          isCandInter[uiArrayAddr] = false;
        }
        else
        {
          uiArrayAddr++;
        }
      }
    }
  }

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

  int iNumRefIdx = slice.isInterB() ? std::min(slice.getNumRefIdx(REF_PIC_LIST_0), slice.getNumRefIdx(REF_PIC_LIST_1)) : slice.getNumRefIdx(REF_PIC_LIST_0);

  int r = 0;
  int refcnt = 0;
  while (uiArrayAddr < maxNumMergeCand)
  {
#if !JVET_L0090_PAIR_AVG
    isCandInter               [uiArrayAddr     ] = true;
#endif
    mrgCtx.interDirNeighbours [uiArrayAddr     ] = 1;
    mrgCtx.GBiIdx             [uiArrayAddr     ] = GBI_DEFAULT;
    mrgCtx.mvFieldNeighbours  [uiArrayAddr << 1].setMvField(Mv(0, 0), r);

    if (slice.isInterB())
    {
      mrgCtx.interDirNeighbours [ uiArrayAddr          ] = 3;
      mrgCtx.mvFieldNeighbours  [(uiArrayAddr << 1) + 1].setMvField(Mv(0, 0), r);
    }

    if ( mrgCtx.interDirNeighbours[uiArrayAddr] == 1 && pu.cs->slice->getRefPic(REF_PIC_LIST_0, mrgCtx.mvFieldNeighbours[uiArrayAddr << 1].refIdx)->getPOC() == pu.cs->slice->getPOC())
    {
      mrgCtx.mrgTypeNeighbours[uiArrayAddr] = MRG_TYPE_IBC;
    }

    uiArrayAddr++;

    if (refcnt == iNumRefIdx - 1)
    {
      r = 0;
    }
    else
    {
      ++r;
      ++refcnt;
    }
  }
  mrgCtx.numValidMergeCand = uiArrayAddr;
}
// for ibc pu validation
bool PU::isBlockVectorValid(PredictionUnit& pu, int xPos, int yPos, int width, int height, int picWidth, int picHeight, int xStartInCU, int yStartInCU, int xBv, int yBv, int ctuSize)
{
  const int ctuSizeLog2 = g_aucLog2[ctuSize];

  int refRightX = xPos + xBv + width - 1;
  int refBottomY = yPos + yBv + height - 1;

  int refLeftX = xPos + xBv;
  int refTopY = yPos + yBv;

  if ((xPos + xBv) < 0)
  {
    return false;
  }
  if (refRightX >= picWidth)
  {
    return false;
  }

  if ((yPos + yBv) < 0)
  {
    return false;
  }
  if (refBottomY >= picHeight)
  {
    return false;
  }
  if ((xBv + width) > 0 && (yBv + height) > 0)
  {
    return false;
  }

  // cannot be in the above CTU row
  if (refTopY >> ctuSizeLog2 < yPos >> ctuSizeLog2)
    return false;

  // cannot be in the below CTU row
  if (refBottomY >> ctuSizeLog2 > yPos >> ctuSizeLog2)
  {
    return false;
  }

  // in the same CTU line
#if JVET_M0407_IBC_RANGE
  if ((refRightX >> ctuSizeLog2 <= xPos >> ctuSizeLog2) && (refLeftX >> ctuSizeLog2 >= (xPos >> ctuSizeLog2) - 1))
#else
  if ((refRightX >> ctuSizeLog2 <= xPos >> ctuSizeLog2) && (refLeftX >> ctuSizeLog2 >= (xPos >> ctuSizeLog2)))
#endif
  {

#if JVET_M0407_IBC_RANGE
    // in the same CTU, or left CTU
    // if part of ref block is in the left CTU, some area can be referred from the not-yet updated local CTU buffer
    if ((refLeftX >> ctuSizeLog2) == ((xPos >> ctuSizeLog2) - 1))
    {
      // ref block's collocated block in current CTU
      const Position refPosCol = pu.Y().topLeft().offset(xBv + ctuSize, yBv);
      int offset64x = (refPosCol.x >> (ctuSizeLog2 - 1)) << (ctuSizeLog2 - 1);
      int offset64y = (refPosCol.y >> (ctuSizeLog2 - 1)) << (ctuSizeLog2 - 1);
      const Position refPosCol64x64 = {offset64x, offset64y};
      if (pu.cs->isDecomp(refPosCol64x64, toChannelType(COMPONENT_Y)))
        return false;
    }
#endif
#if !JVET_M0407_IBC_RANGE
    // in the same CTU, check if the reference block is already coded
    const Position refPosLT = pu.Y().topLeft().offset(xBv, yBv);
    const Position refPosBR = pu.Y().bottomRight().offset(xBv, yBv);
    const ChannelType      chType = toChannelType(COMPONENT_Y);
    {
      if (!pu.cs->isDecomp(refPosBR, chType))
        return false;
      if (!pu.cs->isDecomp(refPosLT, chType))
        return false;
    }
    return true;
#endif
  }
  else
    return false;

#if JVET_M0407_IBC_RANGE
  // in the same CTU, or valid area from left CTU. Check if the reference block is already coded
  const Position refPosLT = pu.Y().topLeft().offset(xBv, yBv);
  const Position refPosBR = pu.Y().bottomRight().offset(xBv, yBv);
  const ChannelType      chType = toChannelType(COMPONENT_Y);
  if (!pu.cs->isDecomp(refPosBR, chType))
    return false;
  if (!pu.cs->isDecomp(refPosLT, chType))
    return false;
  return true;
#endif

}// for ibc pu validation

static int xGetDistScaleFactor(const int &iCurrPOC, const int &iCurrRefPOC, const int &iColPOC, const int &iColRefPOC)
{
  int iDiffPocD = iColPOC - iColRefPOC;
  int iDiffPocB = iCurrPOC - iCurrRefPOC;

  if (iDiffPocD == iDiffPocB)
  {
    return 4096;
  }
  else
  {
    int iTDB = Clip3(-128, 127, iDiffPocB);
    int iTDD = Clip3(-128, 127, iDiffPocD);
    int iX = (0x4000 + abs(iTDD / 2)) / iTDD;
    int iScale = Clip3(-4096, 4095, (iTDB * iX + 32) >> 6);
    return iScale;
  }
}

#if JVET_M0512_MOTION_BUFFER_COMPRESSION
int convertMvFixedToFloat(int32_t val)
{
  int sign  = val >> 31;
  int scale = floorLog2((val ^ sign) | MV_MANTISSA_UPPER_LIMIT) - (MV_MANTISSA_BITCOUNT - 1);

  int exponent;
  int mantissa;
  if (scale >= 0)
  {
    int round = (1 << scale) >> 1;
    int n     = (val + round) >> scale;
    exponent  = scale + ((n ^ sign) >> (MV_MANTISSA_BITCOUNT - 1));
    mantissa  = (n & MV_MANTISSA_UPPER_LIMIT) | (sign << (MV_MANTISSA_BITCOUNT - 1));
  }
  else
  {
    exponent = 0;
    mantissa = val;
  }

  return exponent | (mantissa << MV_EXPONENT_BITCOUNT);
}

int convertMvFloatToFixed(int val)
{
  int exponent = val & MV_EXPONENT_MASK;
  int mantissa = val >> MV_EXPONENT_BITCOUNT;
  return exponent == 0 ? mantissa : (mantissa ^ MV_MANTISSA_LIMIT) << (exponent - 1);
}

int roundMvComp(int x)
{
  return convertMvFloatToFixed(convertMvFixedToFloat(x));
}
#endif

int PU::getDistScaleFactor(const int &currPOC, const int &currRefPOC, const int &colPOC, const int &colRefPOC)
{
  return xGetDistScaleFactor(currPOC, currRefPOC, colPOC, colRefPOC);
}

void PU::getInterMMVDMergeCandidates(const PredictionUnit &pu, MergeCtx& mrgCtx, const int& mrgCandIdx)
{
  int refIdxList0, refIdxList1;
  int k;
  int currBaseNum = 0;
  const uint16_t maxNumMergeCand = mrgCtx.numValidMergeCand;

  for (k = 0; k < maxNumMergeCand; k++)
  {
    if (mrgCtx.mrgTypeNeighbours[k] == MRG_TYPE_DEFAULT_N)
    {
      refIdxList0 = mrgCtx.mvFieldNeighbours[(k << 1)].refIdx;
      refIdxList1 = mrgCtx.mvFieldNeighbours[(k << 1) + 1].refIdx;

      if ((refIdxList0 >= 0) && (refIdxList1 >= 0))
      {
        mrgCtx.mmvdBaseMv[currBaseNum][0] = mrgCtx.mvFieldNeighbours[(k << 1)];
        mrgCtx.mmvdBaseMv[currBaseNum][1] = mrgCtx.mvFieldNeighbours[(k << 1) + 1];
      }
      else if (refIdxList0 >= 0)
      {
        mrgCtx.mmvdBaseMv[currBaseNum][0] = mrgCtx.mvFieldNeighbours[(k << 1)];
        mrgCtx.mmvdBaseMv[currBaseNum][1] = MvField(Mv(0, 0), -1);
      }
      else if (refIdxList1 >= 0)
      {
        mrgCtx.mmvdBaseMv[currBaseNum][0] = MvField(Mv(0, 0), -1);
        mrgCtx.mmvdBaseMv[currBaseNum][1] = mrgCtx.mvFieldNeighbours[(k << 1) + 1];
      }

      currBaseNum++;

      if (currBaseNum == MMVD_BASE_MV_NUM)
        break;
    }
  }