xIntraCodingTUBlock函数主要是进行帧内编码并计算相应的失真，用于上层函数对最佳预测模式和最佳变换模式的选择。
xIntraCodingTUBlock函数流程如下：
- 初始化使用模式
- 进行预测并保存预测信号
- 由预测信号和原始信号获得残差信号
- 进行变换和量化
- 进行反变换
- 重建
- 更新失真distortion
代码如下所示：
//帧内编码TU block
void IntraSearch::xIntraCodingTUBlock(TransformUnit &tu, const ComponentID &compID, const bool &checkCrossCPrediction, Distortion& ruiDist, const int &default0Save1Load2, uint32_t* numSig, std::vector<TrMode>* trModes, const bool loadTr)
{
if (!tu.blocks[compID].valid())
{
return;
}
CodingStructure &cs = *tu.cs;
m_pcRdCost->setChromaFormat(cs.sps->getChromaFormatIdc());
const CompArea &area = tu.blocks[compID];
const SPS &sps = *cs.sps;
const PPS &pps = *cs.pps;
const ChannelType chType = toChannelType(compID);
const int bitDepth = sps.getBitDepth(chType);
PelBuf piOrg = cs.getOrgBuf (area);
PelBuf piPred = cs.getPredBuf (area);
PelBuf piResi = cs.getResiBuf (area);
PelBuf piOrgResi = cs.getOrgResiBuf(area);
PelBuf piReco = cs.getRecoBuf (area);
const PredictionUnit &pu = *cs.getPU(area.pos(), chType);
const uint32_t uiChFinalMode = PU::getFinalIntraMode(pu, chType);
const bool bUseCrossCPrediction = pps.getPpsRangeExtension().getCrossComponentPredictionEnabledFlag() && isChroma( compID ) && PU::isChromaIntraModeCrossCheckMode( pu ) && checkCrossCPrediction;
const bool ccUseRecoResi = m_pcEncCfg->getUseReconBasedCrossCPredictionEstimate();
#if !JVET_O0502_ISP_CLEANUP
const bool ispSplitIsAllowed = sps.getUseISP() && CU::canUseISP( *tu.cu, compID );
#endif
//===== init availability pattern =====
#if JVET_O0105_ICT
CHECK( tu.jointCbCr && compID == COMPONENT_Cr, "wrong combination of compID and jointCbCr" );
#endif
bool jointCbCr = tu.jointCbCr && compID == COMPONENT_Cb;
if ( compID == COMPONENT_Y )
{
PelBuf sharedPredTS( m_pSharedPredTransformSkip[compID], area );
if( default0Save1Load2 != 2 )
{
#if JVET_O0502_ISP_CLEANUP
#if JVET_O0106_ISP_4xN_PREDREG_FOR_1xN_2xN
bool predRegDiffFromTB = CU::isPredRegDiffFromTB(*tu.cu, compID);
bool firstTBInPredReg = CU::isFirstTBInPredReg(*tu.cu, compID, area);
CompArea areaPredReg(COMPONENT_Y, tu.chromaFormat, area);
#endif
if (tu.cu->ispMode && isLuma(compID))
{
#if JVET_O0106_ISP_4xN_PREDREG_FOR_1xN_2xN
if (predRegDiffFromTB)
{
if (firstTBInPredReg)
{
CU::adjustPredArea(areaPredReg);
initIntraPatternChTypeISP(*tu.cu, areaPredReg, piReco);
}
}
else
#endif
initIntraPatternChTypeISP(*tu.cu, area, piReco);
}
else
{
initIntraPatternChType(*tu.cu, area);
}
#else
#if JVET_O0106_ISP_4xN_PREDREG_FOR_1xN_2xN
bool predRegDiffFromTB = CU::isPredRegDiffFromTB(*tu.cu, compID);
bool firstTBInPredReg = CU::isFirstTBInPredReg(*tu.cu, compID, area);
CompArea areaPredReg(COMPONENT_Y, tu.chromaFormat, area);
if (predRegDiffFromTB)
{
if (firstTBInPredReg)
{
CU::adjustPredArea(areaPredReg);
initIntraPatternChType(*tu.cu, areaPredReg);
}
}
else
#endif
initIntraPatternChType(*tu.cu, area);
#endif
//===== get prediction signal =====
if( compID != COMPONENT_Y && PU::isLMCMode( uiChFinalMode ) )
{
{
xGetLumaRecPixels( pu, area );
}
predIntraChromaLM( compID, piPred, pu, area, uiChFinalMode );
}
else
{
if( PU::isMIP( pu, chType ) )
{
predIntraMip( compID, piPred, pu );
}
else
{
#if JVET_O0106_ISP_4xN_PREDREG_FOR_1xN_2xN
if (predRegDiffFromTB)
{
if (firstTBInPredReg)
{
PelBuf piPredReg = cs.getPredBuf(areaPredReg);
predIntraAng(compID, piPredReg, pu);
}
}
else
#endif
predIntraAng(compID, piPred, pu);
}
}
// save prediction
if( default0Save1Load2 == 1 )
{
sharedPredTS.copyFrom( piPred );
}
}
else
{
// load prediction
piPred.copyFrom( sharedPredTS );
}
}
DTRACE( g_trace_ctx, D_PRED, "@(%4d,%4d) [%2dx%2d] IMode=%d\n", tu.lx(), tu.ly(), tu.lwidth(), tu.lheight(), uiChFinalMode );
//DTRACE_PEL_BUF( D_PRED, piPred, tu, tu.cu->predMode, COMPONENT_Y );
const Slice &slice = *cs.slice;
bool flag = slice.getLmcsEnabledFlag() && (slice.isIntra() || (!slice.isIntra() && m_pcReshape->getCTUFlag()));
#if JVET_O0105_ICT
if (isLuma(compID))
{
#else
if (flag && slice.getLmcsChromaResidualScaleFlag() && isChroma(compID))
{
const Area area = tu.Y().valid() ? tu.Y() : Area(recalcPosition(tu.chromaFormat, tu.chType, CHANNEL_TYPE_LUMA, tu.blocks[tu.chType].pos()), recalcSize(tu.chromaFormat, tu.chType, CHANNEL_TYPE_LUMA, tu.blocks[tu.chType].size()));
const CompArea &areaY = CompArea(COMPONENT_Y, tu.chromaFormat, area );
#if JVET_O1109_UNFIY_CRS
int adj = m_pcReshape->calculateChromaAdjVpduNei(tu, areaY);
#else
PelBuf piPredY;
piPredY = cs.picture->getPredBuf(areaY);
const Pel avgLuma = piPredY.computeAvg();
int adj = m_pcReshape->calculateChromaAdj(avgLuma);
#endif
tu.setChromaAdj(adj);
}
#endif
//===== get residual signal =====
piResi.copyFrom( piOrg );
if (slice.getLmcsEnabledFlag() && m_pcReshape->getCTUFlag() && compID == COMPONENT_Y)
{
CompArea tmpArea(COMPONENT_Y, area.chromaFormat, Position(0, 0), area.size());
PelBuf tmpPred = m_tmpStorageLCU.getBuf(tmpArea);
tmpPred.copyFrom(piPred);
piResi.rspSignal(m_pcReshape->getFwdLUT());
piResi.subtract(tmpPred);
}
else
piResi.subtract( piPred );
if (pps.getPpsRangeExtension().getCrossComponentPredictionEnabledFlag() && isLuma(compID))
{
piOrgResi.copyFrom (piResi);
}
if (bUseCrossCPrediction)
{
if (xCalcCrossComponentPredictionAlpha(tu, compID, ccUseRecoResi) == 0)
{
return;
}
CrossComponentPrediction::crossComponentPrediction(tu, compID, cs.getResiBuf(tu.Y()), piResi, piResi, false);
}
#if JVET_O0105_ICT
}
#endif
//===== transform and quantization =====
//变换和量化
//--- init rate estimation arrays for RDOQ ---
//初始化RDOQ的速率估计数组
//--- transform and quantization ---
TCoeff uiAbsSum = 0;
const QpParam cQP(tu, compID);
#if RDOQ_CHROMA_LAMBDA
m_pcTrQuant->selectLambda(compID);
#endif
flag =flag && (tu.blocks[compID].width*tu.blocks[compID].height > 4);
//获得色度残差伸缩系数
if (flag && isChroma(compID) && slice.getLmcsChromaResidualScaleFlag() )
{
int cResScaleInv = tu.getChromaAdj();
#if JVET_O0429_CRS_LAMBDA_FIX
double cResScale = (double)(1 << CSCALE_FP_PREC) / (double)cResScaleInv;
#else
double cResScale = round((double)(1 << CSCALE_FP_PREC) / (double)cResScaleInv);
#endif
m_pcTrQuant->setLambda(m_pcTrQuant->getLambda() / (cResScale*cResScale));
#if !JVET_O0105_ICT
if ( !jointCbCr ) // Joint CbCr signal is to be scaled in the case of joint chroma
piResi.scaleSignal(cResScaleInv, 1, tu.cu->cs->slice->clpRng(compID));
#endif
}
const CompArea &crArea = tu.blocks [ COMPONENT_Cr ];
PelBuf crOrg = cs.getOrgBuf ( crArea );
PelBuf crPred = cs.getPredBuf ( crArea );
PelBuf crResi = cs.getResiBuf ( crArea );
PelBuf crReco = cs.getRecoBuf ( crArea );
if ( jointCbCr )
{
#if !JVET_O0105_ICT
// Get Cr prediction and residual
crResi.copyFrom( crOrg );
crResi.subtract( crPred );
// Create joint residual and store it for Cb component: jointResi = (cbResi - crResi)/2
piResi.subtractAndHalve( crResi );
// Scale the joint signal
if ( flag && slice.getLmcsChromaResidualScaleFlag() )
piResi.scaleSignal(tu.getChromaAdj(), 1, tu.cu->cs->slice->clpRng(compID));
#endif
// Lambda is loosened for the joint mode with respect to single modes as the same residual is used for both chroma blocks
//由于两个色块使用了相同的残差，因此相对于单个模式，对联合模式的Lambda是松散的
#if JVET_O0105_ICT
const int absIct = abs( TU::getICTMode(tu) );
const double lfact = ( absIct == 1 || absIct == 3 ? 0.8 : 0.5 );
m_pcTrQuant->setLambda( lfact * m_pcTrQuant->getLambda() );
#else
m_pcTrQuant->setLambda( 0.60 * m_pcTrQuant->getLambda() );
#endif
}
#if JVET_O0105_ICT
#if JVET_O0376_SPS_JOINTCBCR_FLAG
if ( sps.getJointCbCrEnabledFlag() && isChroma(compID) && (tu.cu->cs->slice->getSliceQp() > 18) )
{
m_pcTrQuant->setLambda( 1.3 * m_pcTrQuant->getLambda() );
}
#else
if( isChroma(compID) && tu.cu->cs->slice->getSliceQp() > 18 )
{
m_pcTrQuant->setLambda( 1.3 * m_pcTrQuant->getLambda() );
}
#endif
#else
#if JVET_O0376_SPS_JOINTCBCR_FLAG
else if ( sps.getJointCbCrEnabledFlag() && isChroma(compID) && (tu.cu->cs->slice->getSliceQp() > 18) )
#else
else if ( isChroma(compID) && tu.cu->cs->slice->getSliceQp() > 18 )
#endif
m_pcTrQuant->setLambda( 1.10 * m_pcTrQuant->getLambda() );
#endif
#if JVET_O0105_ICT
if( isLuma(compID) )//亮度块变换和量化
{
#endif
#if JVET_O0502_ISP_CLEANUP
if (trModes)
{
m_pcTrQuant->transformNxN(tu, compID, cQP, trModes, CU::isIntra(*tu.cu) ? m_pcEncCfg->getIntraMTSMaxCand() : m_pcEncCfg->getInterMTSMaxCand());
tu.mtsIdx = trModes->at(0).first;
}
m_pcTrQuant->transformNxN(tu, compID, cQP, uiAbsSum, m_CABACEstimator->getCtx(), loadTr);
#else
double diagRatio = 0, horVerRatio = 0;
if( trModes )
{
m_pcTrQuant->transformNxN( tu, compID, cQP, trModes, CU::isIntra( *tu.cu ) ? m_pcEncCfg->getIntraMTSMaxCand() : m_pcEncCfg->getInterMTSMaxCand(), ispSplitIsAllowed ? &diagRatio : nullptr, ispSplitIsAllowed ? &horVerRatio : nullptr );
tu.mtsIdx = trModes->at(0).first;
}
m_pcTrQuant->transformNxN( tu, compID, cQP, uiAbsSum, m_CABACEstimator->getCtx(), loadTr, &diagRatio, &horVerRatio );
if ( !tu.cu->ispMode && isLuma(compID) && ispSplitIsAllowed && tu.mtsIdx == MTS_DCT2_DCT2 && ispSplitIsAllowed )
{
m_intraModeDiagRatio .push_back(diagRatio);
m_intraModeHorVerRatio .push_back(horVerRatio);
m_intraModeTestedNormalIntra.push_back((int)uiChFinalMode);
}
#endif
DTRACE( g_trace_ctx, D_TU_ABS_SUM, "%d: comp=%d, abssum=%d\n", DTRACE_GET_COUNTER( g_trace_ctx, D_TU_ABS_SUM ), compID, uiAbsSum );
#if JVET_O0502_ISP_CLEANUP
if (tu.cu->ispMode && isLuma(compID) && CU::isISPLast(*tu.cu, area, area.compID) && CU::allLumaCBFsAreZero(*tu.cu))
{
// ISP has to have at least one non-zero CBF
ruiDist = MAX_INT;
return;
}
#endif
//--- inverse transform ---
//反变换
if (uiAbsSum > 0)
{
m_pcTrQuant->invTransformNxN(tu, compID, piResi, cQP);
}
else
{
piResi.fill(0);
}
#if JVET_O0105_ICT
} // isLuma(compID)
else // 色度块
{
int codedCbfMask = 0;
ComponentID codeCompId = (tu.jointCbCr ? (tu.jointCbCr >> 1 ? COMPONENT_Cb : COMPONENT_Cr) : compID);
const QpParam qpCbCr(tu, codeCompId);
if( tu.jointCbCr )
{
ComponentID otherCompId = ( codeCompId==COMPONENT_Cr ? COMPONENT_Cb : COMPONENT_Cr );
tu.getCoeffs( otherCompId ).fill(0); // do we need that?
TU::setCbfAtDepth (tu, otherCompId, tu.depth, false );
}
PelBuf& codeResi = ( codeCompId == COMPONENT_Cr ? crResi : piResi );
uiAbsSum = 0;
m_pcTrQuant->transformNxN(tu, codeCompId, qpCbCr, uiAbsSum, m_CABACEstimator->getCtx());
DTRACE( g_trace_ctx, D_TU_ABS_SUM, "%d: comp=%d, abssum=%d\n", DTRACE_GET_COUNTER( g_trace_ctx, D_TU_ABS_SUM ), codeCompId, uiAbsSum );
if( uiAbsSum > 0 )
{
m_pcTrQuant->invTransformNxN(tu, codeCompId, codeResi, qpCbCr);
codedCbfMask += ( codeCompId == COMPONENT_Cb ? 2 : 1 );
}
else
{
codeResi.fill(0);
}
if( tu.jointCbCr )
{
if( tu.jointCbCr == 3 && codedCbfMask == 2 )
{
codedCbfMask = 3;
TU::setCbfAtDepth (tu, COMPONENT_Cr, tu.depth, true );
}
if( tu.jointCbCr != codedCbfMask )
{
ruiDist = std::numeric_limits<Distortion>::max();
return;
}
m_pcTrQuant->invTransformICT( tu, piResi, crResi );
uiAbsSum = codedCbfMask;
}
} //色度块
#endif
//===== reconstruction =====
if ( flag && uiAbsSum > 0 && isChroma(compID) && slice.getLmcsChromaResidualScaleFlag() )
{
piResi.scaleSignal(tu.getChromaAdj(), 0, tu.cu->cs->slice->clpRng(compID));
#if JVET_O0105_ICT
if( jointCbCr )
{
crResi.scaleSignal(tu.getChromaAdj(), 0, tu.cu->cs->slice->clpRng(COMPONENT_Cr));
}
#endif
}
if (bUseCrossCPrediction)
{
CrossComponentPrediction::crossComponentPrediction(tu, compID, cs.getResiBuf(tu.Y()), piResi, piResi, true);
#if JVET_O0105_ICT
if( jointCbCr )
{
CrossComponentPrediction::crossComponentPrediction(tu, COMPONENT_Cr, cs.getResiBuf(tu.Y()), crResi, crResi, true);
}
#endif
}
if (slice.getLmcsEnabledFlag() && m_pcReshape->getCTUFlag() && compID == COMPONENT_Y)
{
CompArea tmpArea(COMPONENT_Y, area.chromaFormat, Position(0,0), area.size());
PelBuf tmpPred = m_tmpStorageLCU.getBuf(tmpArea);
tmpPred.copyFrom(piPred);
piReco.reconstruct(tmpPred, piResi, cs.slice->clpRng(compID));
}
else
#if JVET_O0105_ICT
{
piReco.reconstruct(piPred, piResi, cs.slice->clpRng( compID ));
if( jointCbCr )
{
crReco.reconstruct(crPred, crResi, cs.slice->clpRng( COMPONENT_Cr ));
}
}
#else
piReco.reconstruct(piPred, piResi, cs.slice->clpRng( compID ));
#endif
#if !JVET_O0105_ICT
if ( jointCbCr )
{
// Cr uses negative of the signalled Cb residual
if (uiAbsSum > 0)
crResi.copyAndNegate( piResi );
else
crResi.fill(0);
tu.getCoeffs(COMPONENT_Cr).fill(0);
// Set cbf also for Cr
TU::setCbfAtDepth (tu, COMPONENT_Cr, tu.depth, uiAbsSum > 0 ? true : false);
// Cr reconstruction and its contribution to the total error
crReco.reconstruct(crPred, crResi, cs.slice->clpRng( COMPONENT_Cr ));
#if WCG_EXT
if ( m_pcEncCfg->getLumaLevelToDeltaQPMapping().isEnabled() ||
(m_pcEncCfg->getReshaper()
&& slice.getLmcsEnabledFlag()
&& (m_pcReshape->getCTUFlag() || (isChroma(compID) && m_pcEncCfg->getReshapeIntraCMD()))))
{
const CPelBuf orgLuma = cs.getOrgBuf( cs.area.blocks[COMPONENT_Y] );
ruiDist += m_pcRdCost->getDistPart( crOrg, crReco, bitDepth, COMPONENT_Cr, DF_SSE_WTD, &orgLuma );
}
else
#endif
{
ruiDist += m_pcRdCost->getDistPart( crOrg, crReco, bitDepth, COMPONENT_Cr, DF_SSE );
}
}
#endif
//===== update distortion =====
#if WCG_EXT
if (m_pcEncCfg->getLumaLevelToDeltaQPMapping().isEnabled() || (m_pcEncCfg->getReshaper()
&& slice.getLmcsEnabledFlag() && (m_pcReshape->getCTUFlag() || (isChroma(compID) && m_pcEncCfg->getReshapeIntraCMD()))))
{
const CPelBuf orgLuma = cs.getOrgBuf( cs.area.blocks[COMPONENT_Y] );
if (compID == COMPONENT_Y && !(m_pcEncCfg->getLumaLevelToDeltaQPMapping().isEnabled()))
{
CompArea tmpArea1(COMPONENT_Y, area.chromaFormat, Position(0, 0), area.size());
PelBuf tmpRecLuma = m_tmpStorageLCU.getBuf(tmpArea1);
tmpRecLuma.copyFrom(piReco);
tmpRecLuma.rspSignal(m_pcReshape->getInvLUT());
ruiDist += m_pcRdCost->getDistPart(piOrg, tmpRecLuma, sps.getBitDepth(toChannelType(compID)), compID, DF_SSE_WTD, &orgLuma);
}
else
#if JVET_O0105_ICT
{
ruiDist += m_pcRdCost->getDistPart(piOrg, piReco, bitDepth, compID, DF_SSE_WTD, &orgLuma);
if( jointCbCr )
{
ruiDist += m_pcRdCost->getDistPart(crOrg, crReco, bitDepth, COMPONENT_Cr, DF_SSE_WTD, &orgLuma);
}
}
#else
ruiDist += m_pcRdCost->getDistPart(piOrg, piReco, bitDepth, compID, DF_SSE_WTD, &orgLuma);
#endif
}
else
#endif
{
ruiDist += m_pcRdCost->getDistPart( piOrg, piReco, bitDepth, compID, DF_SSE );
#if JVET_O0105_ICT
if( jointCbCr )
{
ruiDist += m_pcRdCost->getDistPart( crOrg, crReco, bitDepth, COMPONENT_Cr, DF_SSE );
}
#endif
}
}
