UnitTools.cpp

void PU::getIntraChromaCandModes( const PredictionUnit &pu, unsigned modeList[NUM_CHROMA_MODE] )
{
  {
    modeList[  0 ] = PLANAR_IDX;
    modeList[  1 ] = VER_IDX;
    modeList[  2 ] = HOR_IDX;
    modeList[  3 ] = DC_IDX;
    modeList[4] = LM_CHROMA_IDX;
    modeList[5] = MDLM_L_IDX;
    modeList[6] = MDLM_T_IDX;
    modeList[7] = DM_CHROMA_IDX;

    Position topLeftPos = pu.blocks[pu.chType].lumaPos();
    Position refPos = topLeftPos.offset( pu.blocks[pu.chType].lumaSize().width >> 1, pu.blocks[pu.chType].lumaSize().height >> 1 );
    const PredictionUnit *lumaPU = CS::isDualITree( *pu.cs ) ? pu.cs->picture->cs->getPU( refPos, CHANNEL_TYPE_LUMA ) : &pu;
#if JVET_N0217_MATRIX_INTRAPRED
    const uint32_t lumaMode = PU::getIntraDirLuma( *lumaPU );
#else
    const uint32_t lumaMode = lumaPU->intraDir[CHANNEL_TYPE_LUMA];
#endif
    for( int i = 0; i < 4; i++ )
    {
      if( lumaMode == modeList[i] )
      {
        modeList[i] = VDIA_IDX;
        break;
      }
    }
  }
}


bool PU::isLMCMode(unsigned mode)
{
  return (mode >= LM_CHROMA_IDX && mode <= MDLM_T_IDX);
}
bool PU::isLMCModeEnabled(const PredictionUnit &pu, unsigned mode)
{
  if ( pu.cs->sps->getUseLMChroma() )
  {
    return true;
  }
  return false;
}

int PU::getLMSymbolList(const PredictionUnit &pu, int *pModeList)
{
  int iIdx = 0;

  pModeList[ iIdx++ ] = LM_CHROMA_IDX;
    pModeList[ iIdx++ ] = -1;
  pModeList[iIdx++] = MDLM_L_IDX;
  pModeList[iIdx++] = MDLM_T_IDX;
  return iIdx;
}



bool PU::isChromaIntraModeCrossCheckMode( const PredictionUnit &pu )
{
  return pu.intraDir[CHANNEL_TYPE_CHROMA] == DM_CHROMA_IDX;
}

#if !JVET_N0302_SIMPLFIED_CIIP
int PU::getMHIntraMPMs(const PredictionUnit &pu, unsigned* mpm, const ChannelType &channelType /*= CHANNEL_TYPE_LUMA*/, const bool isChromaMDMS /*= false*/, const unsigned startIdx /*= 0*/)
{
  const int numMPMs = 3; // Multi-hypothesis intra uses only 3 MPM
  {
    int numCand = -1;
    uint32_t leftIntraDir = DC_IDX, aboveIntraDir = DC_IDX;

    const CompArea& area = pu.block(getFirstComponentOfChannel(channelType));
    const Position& pos = area.pos();

    // Get intra direction of left PU
    const PredictionUnit *puLeft = pu.cs->getPURestricted(pos.offset(-1, 0), pu, channelType);

    if (puLeft && (CU::isIntra(*puLeft->cu) || puLeft->mhIntraFlag))
    {
      leftIntraDir = puLeft->intraDir[channelType];

      if (isChroma(channelType) && leftIntraDir == DM_CHROMA_IDX)
      {
        leftIntraDir = puLeft->intraDir[0];
      }
    }

    // Get intra direction of above PU
    const PredictionUnit* puAbove = pu.cs->getPURestricted(pos.offset(0, -1), pu, channelType);

    if (puAbove && (CU::isIntra(*puAbove->cu) || puAbove->mhIntraFlag) && CU::isSameCtu(*pu.cu, *puAbove->cu))
    {
      aboveIntraDir = puAbove->intraDir[channelType];

      if (isChroma(channelType) && aboveIntraDir == DM_CHROMA_IDX)
      {
        aboveIntraDir = puAbove->intraDir[0];
      }
    }

    CHECK(2 >= numMPMs, "Invalid number of most probable modes");

    uint32_t leftIntraDir2 = leftIntraDir;
    uint32_t aboveIntraDir2 = aboveIntraDir;

    leftIntraDir2 = (leftIntraDir2 > DC_IDX) ? ((leftIntraDir2 <= DIA_IDX) ? HOR_IDX : VER_IDX) : leftIntraDir2;
    aboveIntraDir2 = (aboveIntraDir2 > DC_IDX) ? ((aboveIntraDir2 <= DIA_IDX) ? HOR_IDX : VER_IDX) : aboveIntraDir2;

    if (leftIntraDir2 == aboveIntraDir2)
    {
      numCand = 1;

      if (leftIntraDir2 > DC_IDX) // angular modes
      {
        mpm[0] = leftIntraDir2;
        mpm[1] = PLANAR_IDX;
        mpm[2] = DC_IDX;
      }
      else //non-angular
      {
        mpm[0] = PLANAR_IDX;
        mpm[1] = DC_IDX;
        mpm[2] = VER_IDX;
      }
    }
    else
    {
      numCand = 2;

      mpm[0] = leftIntraDir2;
      mpm[1] = aboveIntraDir2;

      if (leftIntraDir2 && aboveIntraDir2) //both modes are non-planar
      {
        mpm[2] = PLANAR_IDX;
      }
      else
      {
        mpm[2] = (leftIntraDir2 + aboveIntraDir2) < 2 ? VER_IDX : DC_IDX;
      }
    }
    int narrowCase = getNarrowShape(pu.lwidth(), pu.lheight());
    if (narrowCase > 0)
    {
      bool isMPM[NUM_LUMA_MODE];
      for (int idx = 0; idx < NUM_LUMA_MODE; idx++)
      {
        isMPM[idx] = false;
      }
      for (int idx = 0; idx < numMPMs; idx++)
      {
        isMPM[mpm[idx]] = true;
      }
      if (narrowCase == 1 && isMPM[HOR_IDX])
      {
        for (int idx = 0; idx < numMPMs; idx++)
        {
          if (mpm[idx] == HOR_IDX)
          {
            if (!isMPM[PLANAR_IDX])
              mpm[idx] = PLANAR_IDX;
            else if (!isMPM[DC_IDX])
              mpm[idx] = DC_IDX;
            else if (!isMPM[VER_IDX])
              mpm[idx] = VER_IDX;
            break;
          }
        }
      }
      if (narrowCase == 2 && isMPM[VER_IDX])
      {
        for (int idx = 0; idx < numMPMs; idx++)
        {
          if (mpm[idx] == VER_IDX)
          {
            if (!isMPM[PLANAR_IDX])
              mpm[idx] = PLANAR_IDX;
            else if (!isMPM[DC_IDX])
              mpm[idx] = DC_IDX;
            else if (!isMPM[HOR_IDX])
              mpm[idx] = HOR_IDX;
            break;
          }
        }
      }
    }
    CHECK(numCand == 0, "No candidates found");
    CHECK(mpm[0] == mpm[1] || mpm[0] == mpm[2] || mpm[2] == mpm[1], "redundant MPM");
    return numCand;
  }
}
#endif
int PU::getNarrowShape(const int width, const int height)
{
  int longSide = (width > height) ? width : height;
  int shortSide = (width > height) ? height : width;
  if (longSide > (2 * shortSide))
  {
    if (longSide == width)
      return 1;
    else
      return 2;
  }
  else
  {
    return 0;
  }
}

uint32_t PU::getFinalIntraMode( const PredictionUnit &pu, const ChannelType &chType )
{
  uint32_t uiIntraMode = pu.intraDir[chType];

  if( uiIntraMode == DM_CHROMA_IDX && !isLuma( chType ) )
  {
    Position topLeftPos = pu.blocks[pu.chType].lumaPos();
    Position refPos = topLeftPos.offset( pu.blocks[pu.chType].lumaSize().width >> 1, pu.blocks[pu.chType].lumaSize().height >> 1 );
    const PredictionUnit &lumaPU = CS::isDualITree( *pu.cs ) ? *pu.cs->picture->cs->getPU( refPos, CHANNEL_TYPE_LUMA ) : *pu.cs->getPU( topLeftPos, CHANNEL_TYPE_LUMA );

#if JVET_N0217_MATRIX_INTRAPRED
    uiIntraMode = PU::getIntraDirLuma( lumaPU );
#else
    uiIntraMode = lumaPU.intraDir[0];
#endif
  }
#if JVET_N0671_CHROMA_FORMAT_422
  if( pu.chromaFormat == CHROMA_422 && !isLuma( chType ) && uiIntraMode < NUM_LUMA_MODE ) // map directional, planar and dc
#else
  if( pu.chromaFormat == CHROMA_422 && !isLuma( chType ) )
#endif //JVET_N0671_CHROMA_FORMAT_422
  {
    uiIntraMode = g_chroma422IntraAngleMappingTable[uiIntraMode];
  }
  return uiIntraMode;
}

#if JVET_N0193_LFNST
int PU::getWideAngIntraMode( const TransformUnit &tu, const uint32_t dirMode, const ComponentID compID )
{
  if( dirMode < 2 )
  {
    return ( int ) dirMode;
  }

  CodingStructure& cs           = *tu.cs;
  const CompArea&  area         = tu.blocks[ compID ];
  PelBuf           pred         = cs.getPredBuf( area );
  int              width        = int( pred.width );
  int              height       = int( pred.height );
  int              modeShift[ ] = { 0, 6, 10, 12, 14, 15 };
  int              deltaSize    = abs( g_aucLog2[ width ] - g_aucLog2[ height ] );
  int              predMode     = dirMode;

  if( width > height && dirMode < 2 + modeShift[ deltaSize ] )
  {
    predMode += ( VDIA_IDX - 1 );
  }
  else if( height > width && predMode > VDIA_IDX - modeShift[ deltaSize ] )
  {
    predMode -= ( VDIA_IDX + 1 );
  }

  return predMode;
}
#endif

bool PU::xCheckSimilarMotion(const int mergeCandIndex, const int prevCnt, const MergeCtx mergeCandList, bool hasPruned[MRG_MAX_NUM_CANDS])
{
  for (uint32_t ui = 0; ui < prevCnt; ui++)
  {
    if (hasPruned[ui])
    {
      continue;
    }
    if (mergeCandList.interDirNeighbours[ui] == mergeCandList.interDirNeighbours[mergeCandIndex])
    {
      if (mergeCandList.interDirNeighbours[ui] == 3)
      {
        int offset0 = (ui * 2);
        int offset1 = (mergeCandIndex * 2);
        if (mergeCandList.mvFieldNeighbours[offset0].refIdx == mergeCandList.mvFieldNeighbours[offset1].refIdx &&
            mergeCandList.mvFieldNeighbours[offset0 + 1].refIdx == mergeCandList.mvFieldNeighbours[offset1 + 1].refIdx &&
            mergeCandList.mvFieldNeighbours[offset0].mv == mergeCandList.mvFieldNeighbours[offset1].mv &&
            mergeCandList.mvFieldNeighbours[offset0 + 1].mv == mergeCandList.mvFieldNeighbours[offset1 + 1].mv
          )
        {
          hasPruned[ui] = true;
          return true;
        }
      }
      else
      {
        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 CodingStructure &cs, MergeCtx& mrgCtx, bool canFastExit, const int& mrgCandIdx, const uint32_t maxNumMergeCandMin1, int &cnt, const int prevCnt, bool isAvailableSubPu, unsigned subPuMvpPos
  , bool ibcFlag
  , bool isShared
)
#else

bool PU::addMergeHMVPCand(const CodingStructure &cs, 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
{
  const Slice& slice = *cs.slice;
  MotionInfo miNeighbor;
  bool hasPruned[MRG_MAX_NUM_CANDS];
  memset(hasPruned, 0, MRG_MAX_NUM_CANDS * sizeof(bool));
  if (isAvailableSubPu)
  {
    hasPruned[subPuMvpPos] = true;
  }
#if JVET_N0266_SMALL_BLOCKS
  auto &lut = ibcFlag ? ( isShared ? cs.motionLut.lutShareIbc : cs.motionLut.lutIbc ) : cs.motionLut.lut;
#else
  auto &lut = ibcFlag ? ( isShared ? cs.motionLut.lutShareIbc : cs.motionLut.lutIbc ) : ( isShared ? cs.motionLut.lutShare : cs.motionLut.lut );
#endif
  int num_avai_candInLUT = (int) lut.size();

  for (int mrgIdx = 1; mrgIdx <= num_avai_candInLUT; mrgIdx++)
  {
    miNeighbor = lut[num_avai_candInLUT - mrgIdx];
    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_N0843_BVP_SIMPLIFICATION
    if (mrgIdx > 2 || (mrgIdx > 1 && ibcFlag) || !xCheckSimilarMotion(cnt, prevCnt, mrgCtx, hasPruned))
#else
    if (mrgIdx > 2 || !xCheckSimilarMotion(cnt, prevCnt, mrgCtx, hasPruned))
#endif
    {
#if !JVET_L0090_PAIR_AVG
      isCandInter[cnt] = true;
#endif
      mrgCtx.GBiIdx[cnt] = (mrgCtx.interDirNeighbours[cnt] == 3) ? miNeighbor.GBiIdx : GBI_DEFAULT;
      if (mrgCandIdx == cnt && canFastExit)
      {
        return true;
      }
      cnt ++;
      if (cnt  == maxNumMergeCandMin1)
      {
        break;
      }
    }
  }
  return false;
}

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_N0843_BVP_SIMPLIFICATION==0
  const Position posLT = pu.shareParentPos;
#endif
  const Position posRT = pu.shareParentPos.offset(pu.shareParentSize.width - 1, 0);
  const Position posLB = pu.shareParentPos.offset(0, pu.shareParentSize.height - 1);

  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;
  }

  int spatialCandPos = cnt;

#if JVET_N0843_BVP_SIMPLIFICATION==0
  // 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;
  }
#endif

#if JVET_N0843_BVP_SIMPLIFICATION
  int maxNumMergeCandMin1 = maxNumMergeCand;
#else
  int maxNumMergeCandMin1 = maxNumMergeCand - 1;
#endif
  if (cnt != maxNumMergeCandMin1)
  {
    bool isAvailableSubPu = false;
    unsigned subPuMvpPos = 0;

    bool  isShared = ((pu.Y().lumaSize().width != pu.shareParentSize.width) || (pu.Y().lumaSize().height != pu.shareParentSize.height));

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

#if JVET_L0090_PAIR_AVG && JVET_N0843_BVP_SIMPLIFICATION==0
  // pairwise-average candidates
    if (cnt>1 && cnt <maxNumMergeCand)
    {
       mrgCtx.mvFieldNeighbours[cnt * 2    ].setMvField(Mv(0, 0), NOT_VALID);
       mrgCtx.mvFieldNeighbours[cnt * 2 + 1].setMvField(Mv(0, 0), NOT_VALID);

       const Mv& MvI = mrgCtx.mvFieldNeighbours[0 * 2].mv;
       const Mv& MvJ = mrgCtx.mvFieldNeighbours[1 * 2].mv;
       // average two MVs
       Mv avgMv = MvI;

       avgMv += MvJ;
       mrgCtx.mrgTypeNeighbours[cnt] = MRG_TYPE_IBC;
       roundAffineMv(avgMv.hor, avgMv.ver, 1);
       avgMv.roundToPrecision(MV_PRECISION_INTERNAL, MV_PRECISION_INT);
      mrgCtx.mvFieldNeighbours[cnt * 2 ].setMvField(avgMv, MAX_NUM_REF);
      mrgCtx.interDirNeighbours[cnt] = 1;
      cnt++;
    }

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

#if JVET_N0317_ADD_ZERO_BV
    while (cnt < maxNumMergeCand)
    {
      mrgCtx.mvFieldNeighbours[cnt * 2].setMvField(Mv(0, 0), MAX_NUM_REF);
      mrgCtx.interDirNeighbours[cnt] = 1;
      cnt++;
      if (mrgCandIdx == cnt && canFastExit)
      {
        return;
      }
    }
#endif

  mrgCtx.numValidMergeCand = cnt;

}

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_N0266_SMALL_BLOCKS
  const Position posLT = pu.Y().topLeft();
  const Position posRT = pu.Y().topRight();
  const Position posLB = pu.Y().bottomLeft();
#else
  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);
#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
    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 (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::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;
      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 (mrgCandIdx == cnt && canFastExit)
      {
        return;
      }

      cnt++;
    }
  }

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

  int spatialCandPos = cnt;

  // 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;
      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 (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::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
      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 (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::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
        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 (mrgCandIdx == cnt && canFastExit)
        {
          return;
        }

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

#if JVET_N0213_TMVP_REMOVAL
  if (slice.getEnableTMVPFlag() && (pu.lumaSize().width + pu.lumaSize().height > 12))
#else
  if (slice.getEnableTMVPFlag())
#endif
  {
    //>> MTK colocated-RightBottom
    // offset the pos to be sure to "point" to the same position the uiAbsPartIdx would've pointed to
#if JVET_N0266_SMALL_BLOCKS
    Position posRB = pu.Y().bottomRight().offset( -3, -3 );
#else
    Position posRB = pu.shareParentPos.offset(pu.shareParentSize.width-3, pu.shareParentSize.height - 3);
#endif
    const PreCalcValues& pcv = *cs.pcv;

    Position posC0;
#if JVET_N0266_SMALL_BLOCKS
    Position posC1 = pu.Y().center();
#else
    Position posC1 = pu.shareParentPos.offset((pu.shareParentSize.width/2), (pu.shareParentSize.height/2));
#endif
    bool C0Avail = false;
#if !JVET_N0266_SMALL_BLOCKS
    bool C1Avail = (posC1.x < pcv.lumaWidth) && (posC1.y  < pcv.lumaHeight);
#endif
    if (((posRB.x + pcv.minCUWidth) < pcv.lumaWidth) && ((posRB.y + pcv.minCUHeight) < pcv.lumaHeight))
    {
      int posYInCtu = posRB.y & pcv.maxCUHeightMask;
      if (posYInCtu + 4 < pcv.maxCUHeight)
      {
        posC0 = posRB.offset(4, 4);
        C0Avail = true;
      }
    }

    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_N0266_SMALL_BLOCKS
                              || getColocatedMVP( pu, REF_PIC_LIST_0, posC1, cColMv, iRefIdx );
#else
                                      || ( C1Avail && 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_N0266_SMALL_BLOCKS
                   || getColocatedMVP( pu, REF_PIC_LIST_1, posC1, cColMv, iRefIdx );
#else
                           || (C1Avail &&  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 (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_L0090_PAIR_AVG
#if JVET_N0266_SMALL_BLOCKS
    bool isShared = false;
#else