UnitTools.cpp

  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
#if JVET_L0646_GBI
    mrgCtx.GBiIdx[ui] = GBI_DEFAULT;
#endif
    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;
  const Position posLT = pu.Y().topLeft();
  const Position posRT = pu.Y().topRight();
  const Position posLB = pu.Y().bottomLeft();

  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;
#if JVET_L0646_GBI
    mrgCtx.GBiIdx[cnt] = (mrgCtx.interDirNeighbours[cnt] == 3) ? puLeft->cu->GBiIdx : GBI_DEFAULT;
#endif
    // 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
#if JVET_L0646_GBI
      mrgCtx.GBiIdx[cnt] = (mrgCtx.interDirNeighbours[cnt] == 3) ? puAbove->cu->GBiIdx : GBI_DEFAULT;
#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( mrgCandIdx == cnt && canFastExit )
      {
        return;
      }

      cnt++;
    }
  }

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

  // 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
#if JVET_L0646_GBI
      mrgCtx.GBiIdx[cnt] = (mrgCtx.interDirNeighbours[cnt] == 3) ? puAboveRight->cu->GBiIdx : GBI_DEFAULT;
#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( 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;
#if JVET_L0646_GBI
      mrgCtx.GBiIdx[cnt] = (mrgCtx.interDirNeighbours[cnt] == 3) ? puLeftBottom->cu->GBiIdx : GBI_DEFAULT;
#endif
      // 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;
  }

#if !JVET_L0369_SUBBLOCK_MERGE
  bool enableSubPuMvp = slice.getSPS()->getSpsNext().getUseSubPuMvp();
  bool isAvailableSubPu = false;
  unsigned subPuMvpPos = 0;

  if( enableSubPuMvp )
  {
    CHECK( mrgCtx.subPuMvpMiBuf   .area() == 0 || !mrgCtx.subPuMvpMiBuf   .buf, "Buffer not initialized" );

    mrgCtx.subPuMvpMiBuf   .fill( MotionInfo() );
  }

  if( enableSubPuMvp && slice.getEnableTMVPFlag() )
  {
    bool bMrgIdxMatchATMVPCan = ( mrgCandIdx == cnt );
    bool tmpLICFlag           = false;

    isAvailableSubPu = cs.sps->getSpsNext().getUseATMVP() &&     
      getInterMergeSubPuMvpCand( pu, mrgCtx, tmpLICFlag, cnt 
#if JVET_L0054_MMVD
        , mmvdList
#endif
    );

    if( isAvailableSubPu )
    {
#if !JVET_L0090_PAIR_AVG
      isCandInter[cnt] = true;
#endif

      mrgCtx.mrgTypeNeighbours[cnt] = MRG_TYPE_SUBPU_ATMVP;

      if( bMrgIdxMatchATMVPCan )
      {
        return;
      }
      subPuMvpPos = cnt;
      cnt++;

      if( cnt == maxNumMergeCand )
      {
        return;
      }
    }

  }
#endif

  // above left
#if JVET_L0369_SUBBLOCK_MERGE
  if ( cnt < 4 )
#else
  if( cnt < ( enableSubPuMvp ? 6 : 4 ) )
#endif
  {
    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;
#if JVET_L0646_GBI
        mrgCtx.GBiIdx[cnt] = (mrgCtx.interDirNeighbours[cnt] == 3) ? puAboveLeft->cu->GBiIdx : GBI_DEFAULT;
#endif
        // 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 (slice.getEnableTMVPFlag())
  {
    //>> MTK colocated-RightBottom
    // offset the pos to be sure to "point" to the same position the uiAbsPartIdx would've pointed to
    Position posRB = pu.Y().bottomRight().offset(-3, -3);

    const PreCalcValues& pcv = *cs.pcv;

    Position posC0;
    Position posC1 = pu.Y().center();
    bool C0Avail = false;

    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 ) )
                                      || getColocatedMVP(pu, REF_PIC_LIST_0, posC1, cColMv, iRefIdx );

    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 ) )
                           || getColocatedMVP(pu, REF_PIC_LIST_1, posC1, cColMv, iRefIdx );
      if (bExistMV)
      {
        dir     |= 2;
        mrgCtx.mvFieldNeighbours[2 * uiArrayAddr + 1].setMvField(cColMv, iRefIdx);
      }
    }

    if( dir != 0 )
    {
#if JVET_L0369_SUBBLOCK_MERGE
      bool addTMvp = true;
#else
      bool addTMvp = !( cs.sps->getSpsNext().getUseSubPuMvp() && isAvailableSubPu );
      if( !addTMvp )
      {
        if ( dir != mrgCtx.interDirNeighbours[subPuMvpPos] )
        {
          addTMvp = true;
        }
        else
        {
          for( unsigned refList = 0; refList < NUM_REF_PIC_LIST_01; refList++ )
          {
            if( dir & ( 1 << refList ) )
            {
              if( mrgCtx.mvFieldNeighbours[( cnt << 1 ) + refList] != mrgCtx.mvFieldNeighbours[(subPuMvpPos << 1) + refList] )
              {
                addTMvp = true;
                break;
              }
            }
          }
        }
      }
#endif
#if HM_JEM_MERGE_CANDS
#if JVET_L0369_SUBBLOCK_MERGE
      int iSpanCand = cnt;
#else
      int iSpanCand = isAvailableSubPu ? cnt - 1 : cnt;
#endif
      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
#if JVET_L0646_GBI
        mrgCtx.GBiIdx[uiArrayAddr] = GBI_DEFAULT;
#endif
        if( mrgCandIdx == cnt && canFastExit )
        {
          return;
        }

        cnt++;
      }
    }
  }

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

#if JVET_L0266_HMVP
  int maxNumMergeCandMin1 = maxNumMergeCand - 1;
  if (cnt != maxNumMergeCandMin1)
  {
#if JVET_L0369_SUBBLOCK_MERGE
    bool isAvailableSubPu = false;
    unsigned subPuMvpPos = 0;
#endif
#if JVET_L0090_PAIR_AVG
    bool bFound = addMergeHMVPCand(slice, mrgCtx, canFastExit, mrgCandIdx, maxNumMergeCandMin1, cnt, cnt, isAvailableSubPu, subPuMvpPos);
#else
    bool bFound = addMergeHMVPCand(slice, mrgCtx, isCandInter, canFastExit, mrgCandIdx, maxNumMergeCandMin1, cnt, cnt, isAvailableSubPu, subPuMvpPos);
#endif
    if (bFound)
    {
      return;
    }
  }
#endif

#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 < (slice.isInterB() ? 2 : 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;
#if !REMOVE_MV_ADAPT_PREC
          if( pu.cs->sps->getSpsNext().getUseHighPrecMv() )
          {
            avgMv.setHighPrec();
          }
#endif
          avgMv += MvJ;
          avgMv.setHor( avgMv.getHor() / 2 );
          avgMv.setVer( avgMv.getVer() / 2 );

          mrgCtx.mvFieldNeighbours[cnt * 2 + refListId].setMvField( avgMv, refIdxI );
        }
        // only one MV is valid, take the only one MV
        else if( refIdxI != NOT_VALID )
        {
          Mv singleMv = mrgCtx.mvFieldNeighbours[i * 2 + refListId].mv;
#if !REMOVE_MV_ADAPT_PREC
          if( pu.cs->sps->getSpsNext().getUseHighPrecMv() )
          {
            singleMv.setHighPrec();
          }
#endif
          mrgCtx.mvFieldNeighbours[cnt * 2 + refListId].setMvField( singleMv, refIdxI );
        }
        else if( refIdxJ != NOT_VALID )
        {
          Mv singleMv = mrgCtx.mvFieldNeighbours[j * 2 + refListId].mv;
#if !REMOVE_MV_ADAPT_PREC
          if( pu.cs->sps->getSpsNext().getUseHighPrecMv() )
          {
            singleMv.setHighPrec();
          }
#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
#if JVET_L0266_HMVP
  uint32_t uiCutoff    = std::min( uiArrayAddr, 3u );
#else
  uint32_t uiCutoff    = std::min( uiArrayAddr, 4u );
#endif
  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;
#if JVET_L0646_GBI
        mrgCtx.GBiIdx[uiArrayAddr] = ((mrgCtx.interDirNeighbours[uiArrayAddr] == 3)) ? CU::deriveGbiIdx(mrgCtx.GBiIdx[i], mrgCtx.GBiIdx[j]) : GBI_DEFAULT;
#endif

        // 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;
#if JVET_L0646_GBI
    mrgCtx.GBiIdx             [uiArrayAddr     ] = GBI_DEFAULT;
#endif
    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);
    }

    uiArrayAddr++;

    if (refcnt == iNumRefIdx - 1)
    {
      r = 0;
    }
    else
    {
      ++r;
      ++refcnt;
    }
  }
  mrgCtx.numValidMergeCand = uiArrayAddr;
}


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_L0054_MMVD
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;

#if !REMOVE_MV_ADAPT_PREC
  if (pu.cu->slice->getSPS()->getSpsNext().getUseHighPrecMv())
  {
    for (k = 0; k < maxNumMergeCand; k++)
    {
      if (mrgCtx.mrgTypeNeighbours[k] == MRG_TYPE_DEFAULT_N)
      {
        if ((mrgCtx.mvFieldNeighbours[(k << 1)].mv.highPrec == false) && (mrgCtx.mvFieldNeighbours[(k << 1)].refIdx >= 0))
        {
          mrgCtx.mvFieldNeighbours[(k << 1)].mv.setHighPrec();
        }
        if ((mrgCtx.mvFieldNeighbours[(k << 1) + 1].mv.highPrec == false) && (mrgCtx.mvFieldNeighbours[(k << 1) + 1].refIdx >= 0))
        {
          mrgCtx.mvFieldNeighbours[(k << 1) + 1].mv.setHighPrec();
        }
      }
    }
  }
#endif
  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;
    }
  }

  if (currBaseNum < MMVD_BASE_MV_NUM)
  {
    for (k = currBaseNum; k < MMVD_BASE_MV_NUM; k++)
    {
      mrgCtx.mmvdBaseMv[k][0] = MvField(Mv(0, 0), 0);
      mrgCtx.mmvdBaseMv[k][0] = MvField(Mv(0, 0), 0);
    }
  }
}
#endif
bool PU::getColocatedMVP(const PredictionUnit &pu, const RefPicList &eRefPicList, const Position &_pos, Mv& rcMv, const int &refIdx )
{
  // don't perform MV compression when generally disabled or subPuMvp is used
  const unsigned scale = ( pu.cs->pcv->noMotComp ? 1 : 4 * std::max<int>(1, 4 * AMVP_DECIMATION_FACTOR / 4) );
  const unsigned mask  = ~( scale - 1 );

  const Position pos = Position{ PosType( _pos.x & mask ), PosType( _pos.y & mask ) };

  const Slice &slice = *pu.cs->slice;

  // use coldir.
  const Picture* const pColPic = slice.getRefPic(RefPicList(slice.isInterB() ? 1 - slice.getColFromL0Flag() : 0), slice.getColRefIdx());

  if( !pColPic )
  {
    return false;
  }

  RefPicList eColRefPicList = slice.getCheckLDC() ? eRefPicList : RefPicList(slice.getColFromL0Flag());

  const MotionInfo& mi = pColPic->cs->getMotionInfo( pos );

  if( !mi.isInter )
  {
    return false;
  }
  int iColRefIdx = mi.refIdx[eColRefPicList];

  if (iColRefIdx < 0)
  {
    eColRefPicList = RefPicList(1 - eColRefPicList);
    iColRefIdx = mi.refIdx[eColRefPicList];

    if (iColRefIdx < 0)
    {
      return false;
    }
  }

  const Slice *pColSlice = nullptr;

  for( const auto s : pColPic->slices )
  {
    if( s->getIndependentSliceIdx() == mi.sliceIdx )
    {
      pColSlice = s;
      break;
    }
  }

  CHECK( pColSlice == nullptr, "Slice segment not found" );

  const Slice &colSlice = *pColSlice;

  const bool bIsCurrRefLongTerm = slice.getRefPic(eRefPicList, refIdx)->longTerm;
  const bool bIsColRefLongTerm  = colSlice.getIsUsedAsLongTerm(eColRefPicList, iColRefIdx);

  if (bIsCurrRefLongTerm != bIsColRefLongTerm)
  {
    return false;
  }


  // Scale the vector.
  Mv cColMv = mi.mv[eColRefPicList];

  if (bIsCurrRefLongTerm /*|| bIsColRefLongTerm*/)
  {
    rcMv = cColMv;
  }
  else
  {
    const int currPOC    = slice.getPOC();
    const int colPOC     = colSlice.getPOC();
    const int colRefPOC  = colSlice.getRefPOC(eColRefPicList, iColRefIdx);
    const int currRefPOC = slice.getRefPic(eRefPicList, refIdx)->getPOC();
    const int distscale  = xGetDistScaleFactor(currPOC, currRefPOC, colPOC, colRefPOC);

    if (distscale == 4096)
    {
      rcMv = cColMv;
    }
    else
    {
#if !REMOVE_MV_ADAPT_PREC
      if( pu.cs->sps->getSpsNext().getUseHighPrecMv() )
      {
        // allow extended precision for temporal scaling
        cColMv.setHighPrec();
      }
#endif
      rcMv = cColMv.scaleMv(distscale);
    }
  }

  return true;
}

bool PU::isDiffMER(const PredictionUnit &pu1, const PredictionUnit &pu2)
{
  const unsigned xN = pu1.lumaPos().x;
  const unsigned yN = pu1.lumaPos().y;
  const unsigned xP = pu2.lumaPos().x;
  const unsigned yP = pu2.lumaPos().y;

  unsigned plevel = pu1.cs->pps->getLog2ParallelMergeLevelMinus2() + 2;

  if ((xN >> plevel) != (xP >> plevel))
  {
    return true;
  }

  if ((yN >> plevel) != (yP >> plevel))
  {
    return true;
  }

  return false;
}

/** Constructs a list of candidates for AMVP (See specification, section "Derivation process for motion vector predictor candidates")
* \param uiPartIdx
* \param uiPartAddr
* \param eRefPicList
* \param iRefIdx
* \param pInfo
*/
void PU::fillMvpCand(PredictionUnit &pu, const RefPicList &eRefPicList, const int &refIdx, AMVPInfo &amvpInfo)
{
  CodingStructure &cs = *pu.cs;

  AMVPInfo *pInfo = &amvpInfo;

  pInfo->numCand = 0;

  if (refIdx < 0)
  {
    return;
  }

  //-- Get Spatial MV
  Position posLT = pu.Y().topLeft();
  Position posRT = pu.Y().topRight();
  Position posLB = pu.Y().bottomLeft();

  bool isScaledFlagLX = false; /// variable name from specification; true when the PUs below left or left are available (availableA0 || availableA1).

  {
    const PredictionUnit* tmpPU = cs.getPURestricted( posLB.offset( -1, 1 ), pu, pu.chType ); // getPUBelowLeft(idx, partIdxLB);
    isScaledFlagLX = tmpPU != NULL && CU::isInter( *tmpPU->cu );

    if( !isScaledFlagLX )
    {
      tmpPU = cs.getPURestricted( posLB.offset( -1, 0 ), pu, pu.chType );
      isScaledFlagLX = tmpPU != NULL && CU::isInter( *tmpPU->cu );
    }
  }

  // Left predictor search
  if( isScaledFlagLX )
  {
    bool bAdded = addMVPCandUnscaled( pu, eRefPicList, refIdx, posLB, MD_BELOW_LEFT, *pInfo );

    if( !bAdded )
    {
      bAdded = addMVPCandUnscaled( pu, eRefPicList, refIdx, posLB, MD_LEFT, *pInfo );

      if( !bAdded )
      {
        bAdded = addMVPCandWithScaling( pu, eRefPicList, refIdx, posLB, MD_BELOW_LEFT, *pInfo );

        if( !bAdded )
        {
          addMVPCandWithScaling( pu, eRefPicList, refIdx, posLB, MD_LEFT, *pInfo );
        }
      }
    }
  }

  // Above predictor search
  {
    bool bAdded = addMVPCandUnscaled( pu, eRefPicList, refIdx, posRT, MD_ABOVE_RIGHT, *pInfo );

    if( !bAdded )
    {
      bAdded = addMVPCandUnscaled( pu, eRefPicList, refIdx, posRT, MD_ABOVE, *pInfo );

      if( !bAdded )
      {
        addMVPCandUnscaled( pu, eRefPicList, refIdx, posLT, MD_ABOVE_LEFT, *pInfo );
      }
    }
  }

  if( !isScaledFlagLX )
  {
    bool bAdded = addMVPCandWithScaling( pu, eRefPicList, refIdx, posRT, MD_ABOVE_RIGHT, *pInfo );

    if( !bAdded )
    {
      bAdded = addMVPCandWithScaling( pu, eRefPicList, refIdx, posRT, MD_ABOVE, *pInfo );

      if( !bAdded )
      {
        addMVPCandWithScaling( pu, eRefPicList, refIdx, posLT, MD_ABOVE_LEFT, *pInfo );
      }
    }
  }

  if( pu.cu->imv != 0)
  {
    unsigned imvShift = pu.cu->imv << 1;
#if REMOVE_MV_ADAPT_PREC
    imvShift += VCEG_AZ07_MV_ADD_PRECISION_BIT_FOR_STORE;
#endif
    for( int i = 0; i < pInfo->numCand; i++ )
    {
      roundMV( pInfo->mvCand[i], imvShift );
    }
  }

  if( pInfo->numCand == 2 )
  {
    if( pInfo->mvCand[0] == pInfo->mvCand[1] )
    {
      pInfo->numCand = 1;
    }
  }

  if( cs.slice->getEnableTMVPFlag() )
  {
    // Get Temporal Motion Predictor
    const int refIdx_Col = refIdx;

    Position posRB = pu.Y().bottomRight().offset(-3, -3);

    const PreCalcValues& pcv = *cs.pcv;

    Position posC0;
    bool C0Avail = false;
    Position posC1 = pu.Y().center();

    Mv cColMv;

    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
      {
        // in the reference the CTU address is not set - thus probably resulting in no using this C0 possibility
        posC0 = posRB.offset(4, 4);
      }
      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
      {
        // same as for last column but not last row
        posC0 = posRB.offset(4, 4);
      }
    }