x265,帧内预测代码分析

  1 void Analysis::compressIntraCU(const CUData& parentCTU, const CUGeom& cuGeom, uint32_t& zOrder)
  2 {
  3     uint32_t depth = cuGeom.depth;//geometric  CU几何结构
  4     ModeDepth& md = m_modeDepth[depth];
  5     md.bestMode = NULL;
  6
  7     bool mightSplit = !(cuGeom.flags & CUGeom::LEAF);//为ture非叶子节点，还需继续分裂
  8     bool mightNotSplit = !(cuGeom.flags & CUGeom::SPLIT_MANDATORY);//
  9
 10     if (m_param->analysisMode == X265_ANALYSIS_LOAD)
 11     {
 12         uint8_t* reuseDepth  = &m_reuseIntraDataCTU->depth[parentCTU.m_cuAddr * parentCTU.m_numPartitions];
 13         uint8_t* reuseModes  = &m_reuseIntraDataCTU->modes[parentCTU.m_cuAddr * parentCTU.m_numPartitions];
 14         char* reusePartSizes = &m_reuseIntraDataCTU->partSizes[parentCTU.m_cuAddr * parentCTU.m_numPartitions];
 15
 16         if (mightNotSplit && depth == reuseDepth[zOrder] && zOrder == cuGeom.encodeIdx)
 17         {
 18             m_quant.setQPforQuant(parentCTU);
 19
 20             PartSize size = (PartSize)reusePartSizes[zOrder];
 21             Mode& mode = size == SIZE_2Nx2N ? md.pred[PRED_INTRA] : md.pred[PRED_INTRA_NxN];
 22             mode.cu.initSubCU(parentCTU, cuGeom);
 23             checkIntra(mode, cuGeom, size, &reuseModes[zOrder]);
 24             checkBestMode(mode, depth);
 25
 26             if (m_bTryLossless)
 27                 tryLossless(cuGeom);
 28
 29             if (mightSplit)
 30                 addSplitFlagCost(*md.bestMode, cuGeom.depth);
 31
 32             // increment zOrder offset to point to next best depth in sharedDepth buffer
 33             zOrder += g_depthInc[g_maxCUDepth - 1][reuseDepth[zOrder]];
 34             mightSplit = false;
 35         }
 36     }
 37     else if (mightNotSplit)
 38     {
 39         m_quant.setQPforQuant(parentCTU);
 40
 41         md.pred[PRED_INTRA].cu.initSubCU(parentCTU, cuGeom);
 42         checkIntra(md.pred[PRED_INTRA], cuGeom, SIZE_2Nx2N, NULL);//intra2Nx2N  模式
 43         checkBestMode(md.pred[PRED_INTRA], depth);
 44
 45         if (depth == g_maxCUDepth)
 46         {
 47             md.pred[PRED_INTRA_NxN].cu.initSubCU(parentCTU, cuGeom);
 48             checkIntra(md.pred[PRED_INTRA_NxN], cuGeom, SIZE_NxN, NULL);//INTRA_NxN  模式
 49             checkBestMode(md.pred[PRED_INTRA_NxN], depth);
 50         }
 51
 52         if (m_bTryLossless)
 53             tryLossless(cuGeom);
 54
 55         if (mightSplit)
 56             addSplitFlagCost(*md.bestMode, cuGeom.depth);
 57     }
 58
 59     if (mightSplit)
 60     {
 61         Mode* splitPred = &md.pred[PRED_SPLIT];
 62         splitPred->initCosts();
 63         CUData* splitCU = &splitPred->cu;
 64         splitCU->initSubCU(parentCTU, cuGeom);//分裂成4四subCU
 65
 66         uint32_t nextDepth = depth + 1;
 67         ModeDepth& nd = m_modeDepth[nextDepth];
 68         invalidateContexts(nextDepth);
 69         Entropy* nextContext = &m_rqt[depth].cur;
 70
 71         for (uint32_t subPartIdx = 0; subPartIdx < 4; subPartIdx++)
 72         {
 73             const CUGeom& childGeom = *(&cuGeom + cuGeom.childOffset + subPartIdx);
 74             if (childGeom.flags & CUGeom::PRESENT)
 75             {
 76                 m_modeDepth[0].fencYuv.copyPartToYuv(nd.fencYuv, childGeom.encodeIdx);
 77                 m_rqt[nextDepth].cur.load(*nextContext);
 78                 compressIntraCU(parentCTU, childGeom, zOrder);//递归
 79
 80                 // Save best CU and pred data for this sub CU
 81                 splitCU->copyPartFrom(nd.bestMode->cu, childGeom, subPartIdx);
 82                 splitPred->addSubCosts(*nd.bestMode);
 83                 nd.bestMode->reconYuv.copyToPartYuv(splitPred->reconYuv, childGeom.numPartitions * subPartIdx);
 84                 nextContext = &nd.bestMode->contexts;
 85             }
 86             else
 87             {
 88                 /* record the depth of this non-present sub-CU */
 89                 splitCU->setEmptyPart(childGeom, subPartIdx);
 90                 zOrder += g_depthInc[g_maxCUDepth - 1][nextDepth];
 91             }
 92         }
 93         nextContext->store(splitPred->contexts);
 94         if (mightNotSplit)
 95             addSplitFlagCost(*splitPred, cuGeom.depth);
 96         else
 97             updateModeCost(*splitPred);
 98         checkBestMode(*splitPred, depth);
 99     }
100
101     checkDQP(md.bestMode->cu, cuGeom);
102
103     /* Copy best data to encData CTU and recon */
104     md.bestMode->cu.copyToPic(depth);
105     if (md.bestMode != &md.pred[PRED_SPLIT])
106         md.bestMode->reconYuv.copyToPicYuv(*m_frame->m_reconPic, parentCTU.m_cuAddr, cuGeom.encodeIdx);
107 }