QuantRDOQ.cpp

    int lastCG = -1;
    int absSum = 0 ;
    int n ;

    for( int subSet = (uiWidth*uiHeight-1) >> cctx.log2CGSize(); subSet >= 0; subSet-- )
    {
      int  subPos         = subSet << cctx.log2CGSize();
      int  firstNZPosInCG = iCGSizeM1 + 1, lastNZPosInCG = -1;
      absSum = 0 ;

      for( n = iCGSizeM1; n >= 0; --n )
      {
        if( piDstCoeff[ cctx.blockPos( n + subPos )] )
        {
          lastNZPosInCG = n;
          break;
        }
      }

      for( n = 0; n <= iCGSizeM1; n++ )
      {
        if( piDstCoeff[ cctx.blockPos( n + subPos )] )
        {
          firstNZPosInCG = n;
          break;
        }
      }

      for( n = firstNZPosInCG; n <= lastNZPosInCG; n++ )
      {
        absSum += int(piDstCoeff[ cctx.blockPos( n + subPos )]);
      }

      if(lastNZPosInCG>=0 && lastCG==-1)
      {
        lastCG = 1;
      }

      if( lastNZPosInCG-firstNZPosInCG>=SBH_THRESHOLD )
      {
        uint32_t signbit = (piDstCoeff[cctx.blockPos(subPos+firstNZPosInCG)]>0?0:1);
        if( signbit!=(absSum&0x1) )  // hide but need tune
        {
          // calculate the cost
          int64_t minCostInc = std::numeric_limits<int64_t>::max(), curCost = std::numeric_limits<int64_t>::max();
          int minPos = -1, finalChange = 0, curChange = 0;

          for( n = (lastCG == 1 ? lastNZPosInCG : iCGSizeM1); n >= 0; --n )
          {
            uint32_t uiBlkPos   = cctx.blockPos( n + subPos );
            if(piDstCoeff[ uiBlkPos ] != 0 )
            {
              int64_t costUp   = rdFactor * ( - deltaU[uiBlkPos] ) + rateIncUp[uiBlkPos];
              int64_t costDown = rdFactor * (   deltaU[uiBlkPos] ) + rateIncDown[uiBlkPos]
                -   ((abs(piDstCoeff[uiBlkPos]) == 1) ? sigRateDelta[uiBlkPos] : 0);

              if(lastCG==1 && lastNZPosInCG==n && abs(piDstCoeff[uiBlkPos])==1)
              {
                costDown -= (4<<SCALE_BITS);
              }

              if(costUp<costDown)
              {
                curCost = costUp;
                curChange =  1;
              }
              else
              {
                curChange = -1;
                if(n==firstNZPosInCG && abs(piDstCoeff[uiBlkPos])==1)
                {
                  curCost = std::numeric_limits<int64_t>::max();
                }
                else
                {
                  curCost = costDown;
                }
              }
            }
            else
            {
              curCost = rdFactor * ( - (abs(deltaU[uiBlkPos])) ) + (1<<SCALE_BITS) + rateIncUp[uiBlkPos] + sigRateDelta[uiBlkPos] ;
              curChange = 1 ;

              if(n<firstNZPosInCG)
              {
                uint32_t thissignbit = (plSrcCoeff[uiBlkPos]>=0?0:1);
                if(thissignbit != signbit )
                {
                  curCost = std::numeric_limits<int64_t>::max();
                }
              }
            }

            if( curCost<minCostInc)
            {
              minCostInc = curCost;
              finalChange = curChange;
              minPos = uiBlkPos;
            }
          }

          if(piDstCoeff[minPos] == entropyCodingMaximum || piDstCoeff[minPos] == entropyCodingMinimum)
          {
            finalChange = -1;
          }

          if(plSrcCoeff[minPos]>=0)
          {
            piDstCoeff[minPos] += finalChange ;
          }
          else
          {
            piDstCoeff[minPos] -= finalChange ;
          }
        }
      }

      if(lastCG==1)
      {
        lastCG=0 ;
      }
    }
  }
#endif
}

//! \}