H.265中针对scc的工具 -- transformskip

       transformskip和intra block copy, palatte mode 一样，是针对screen content 的编码工具，该工具的提出是因为对于screen content，其经常包含尖锐边缘或者跳变，相关性极差，这种情况下进行正常的transform反而会带来负面影响，还不如跳过变换环节，直接对残差进行量化。下面来直接看代码：

 if (pcCU->getTransformSkip(uiAbsPartIdx, compID) != 0)//开启transformskip
      {
        xTransformSkip(pcResidual, uiStride, m_plTempCoeff, rTu, compID);
      }
      else.  //执行正常的transform
      {
        const Int channelBitDepth = pcCU->getSlice()->getSPS()->getBitDepth(toChannelType(compID));
        xT(channelBitDepth, rTu.useDST(compID), pcResidual, uiStride, m_plTempCoeff, uiWidth, uiHeight, pcCU->getSlice()->getSPS()->getMaxLog2TrDynamicRange(toChannelType(compID)));
      }

#if DEBUG_TRANSFORM_AND_QUANTISE
      std::cout << g_debugCounter << ": " << uiWidth << "x" << uiHeight << " channel " << compID << " TU between transform and quantiser\n";
      printBlock(m_plTempCoeff, uiWidth, u