JVET-L0428: Delta QP and Chroma QP Offset for Separate Tree

source/Lib/CommonLib/TypeDef.h

@@ -187,6 +187,7 @@
 #define JVET_L0198_L0468_L0104_ATMVP_8x8SUB_BLOCK         1  // Fix sub-block size to 8x8 in ATMVP as proposed in L0198, L0468 and L0104
 #define JVET_L0198_ATMVP_SCAN_SIMP                        1  // Simplification for scan process in ATMVP cTMv derivation
 #define JVET_L0696_CONSTRAINT_SYNTAX                      1 // Starting point for interoperability point syntax
+#define JVET_L0428_DQP_SEP_TREE                           1  // Delta QP for Separate Tree
 // ====================================================================================================================
 // NEXT software switches
 // ====================================================================================================================

source/Lib/DecoderLib/CABACReader.cpp

@@ -579,7 +579,18 @@ bool CABACReader::coding_tree( CodingStructure& cs, Partitioner& partitioner, CU
     cuCtx.qp = CU::predictQP( cu, cuCtx.qp );
   }
 
-  cu.qp          = cuCtx.qp;        //NOTE: CU QP can be changed by deltaQP signaling at TU level
+#if JVET_L0428_DQP_SEP_TREE
+  const Position chromaCentral(cu.chromaPos().offset(cu.chromaSize().width >> 1, cu.chromaSize().height >> 1));
+  const Position lumaRefPos(chromaCentral.x << getComponentScaleX(COMPONENT_Cb, cu.chromaFormat), chromaCentral.y << getComponentScaleY(COMPONENT_Cb, cu.chromaFormat));
+  const CodingUnit* colLumaCu = cs.getCU(lumaRefPos, CHANNEL_TYPE_LUMA);
+
+  if (cu.cs->pps->getUseDQP() && CS::isDualITree(cs) && isChroma(cu.chType))
+  {
+    cuCtx.qp = colLumaCu->qp;
+  }
+#endif
+
+  cu.qp = cuCtx.qp;                 //NOTE: CU QP can be changed by deltaQP signaling at TU level
   cu.chromaQpAdj = cs.chromaQpAdj;  //NOTE: CU chroma QP adjustment can be changed by adjustment signaling at TU level
 
   // coding unit
@@ -2127,15 +2138,18 @@ void CABACReader::transform_unit( TransformUnit& tu, CUCtx& cuCtx, ChromaCbfs& c
   bool        cbfLuma    = ( tu.cbf[ COMPONENT_Y ] != 0 );
   bool        cbfChroma  = ( cu.chromaFormat == CHROMA_400 ? false : ( chromaCbfs.Cb || chromaCbfs.Cr ) );
 
-
-
   if( cbfLuma || cbfChroma )
   {
     if( cu.cs->pps->getUseDQP() && !cuCtx.isDQPCoded )
     {
-      cu_qp_delta( cu, cuCtx.qp, cu.qp );
-      cuCtx.qp         = cu.qp;
-      cuCtx.isDQPCoded = true;
+#if JVET_L0428_DQP_SEP_TREE
+      if (!CS::isDualITree(*tu.cs) || isLuma(tu.chType))
+#endif
+      {
+        cu_qp_delta(cu, cuCtx.qp, cu.qp);
+        cuCtx.qp = cu.qp;
+        cuCtx.isDQPCoded = true;
+      }
     }
     if( cu.cs->slice->getUseChromaQpAdj() && cbfChroma && !cu.transQuantBypass && !cuCtx.isChromaQpAdjCoded )
     {

source/Lib/EncoderLib/CABACWriter.cpp

@@ -2049,7 +2049,6 @@ void CABACWriter::transform_unit( const TransformUnit& tu, CUCtx& cuCtx, ChromaC
   bool        cbfLuma   = ( cbf[ COMPONENT_Y ] != 0 );
   bool        cbfChroma = false;
 
-
   if( cu.chromaFormat != CHROMA_400 )
   {
     if( tu.blocks[COMPONENT_Cb].valid() )
@@ -2063,9 +2062,14 @@ void CABACWriter::transform_unit( const TransformUnit& tu, CUCtx& cuCtx, ChromaC
   {
     if( cu.cs->pps->getUseDQP() && !cuCtx.isDQPCoded )
     {
-      cu_qp_delta( cu, cuCtx.qp, cu.qp );
-      cuCtx.qp         = cu.qp;
-      cuCtx.isDQPCoded = true;
+#if JVET_L0428_DQP_SEP_TREE
+      if ((!CS::isDualITree(*tu.cs) || isLuma(tu.chType)))
+#endif
+      {
+        cu_qp_delta(cu, cuCtx.qp, cu.qp);
+        cuCtx.qp = cu.qp;
+        cuCtx.isDQPCoded = true;
+      }
     }
     if( cu.cs->slice->getUseChromaQpAdj() && cbfChroma && !cu.transQuantBypass && !cuCtx.isChromaQpAdjCoded )
     {

source/Lib/EncoderLib/EncCu.cpp

@@ -401,7 +401,6 @@ void EncCu::compressCtu( CodingStructure& cs, const UnitArea& area, const unsign
 #endif
   );
 
-
   // all signals were already copied during compression if the CTU was split - at this point only the structures are copied to the top level CS
   const bool copyUnsplitCTUSignals = bestCS->cus.size() == 1 && KEEP_PRED_AND_RESI_SIGNALS;
   cs.useSubStructure( *bestCS, partitioner->chType, CS::getArea( *bestCS, area, partitioner->chType ), copyUnsplitCTUSignals, false, false, copyUnsplitCTUSignals );
@@ -703,7 +702,24 @@ void EncCu::xCompressCU( CodingStructure *&tempCS, CodingStructure *&bestCS, Par
 
   do
   {
-    const EncTestMode currTestMode = m_modeCtrl->currTestMode();
+    EncTestMode currTestMode = m_modeCtrl->currTestMode();
+
+#if JVET_L0428_DQP_SEP_TREE
+    if (tempCS->pps->getUseDQP() && partitioner.chType == CHANNEL_TYPE_CHROMA)
+    {
+      const Position chromaCentral(tempCS->area.Cb().chromaPos().offset(tempCS->area.Cb().chromaSize().width >> 1, tempCS->area.Cb().chromaSize().height >> 1));
+      const Position lumaRefPos(chromaCentral.x << getComponentScaleX(COMPONENT_Cb, tempCS->area.chromaFormat), chromaCentral.y << getComponentScaleY(COMPONENT_Cb, tempCS->area.chromaFormat));
+      const CodingStructure* baseCS = bestCS->picture->cs;
+      const CodingUnit* colLumaCu = baseCS->getCU(lumaRefPos, CHANNEL_TYPE_LUMA);
+      const TransformUnit*  tu = baseCS->getTU(lumaRefPos, CHANNEL_TYPE_LUMA);
+
+      if (tu)
+      {
+        currTestMode.qp = colLumaCu->qp;
+      }
+
+    }
+#endif
 
 #if SHARP_LUMA_DELTA_QP
     if( m_pcEncCfg->getLumaLevelToDeltaQPMapping().isEnabled() && partitioner.currDepth <= pps.getMaxCuDQPDepth() )
@@ -1586,6 +1602,13 @@ void EncCu::xCheckDQP( CodingStructure& cs, Partitioner& partitioner, bool bKeep
     return;
   }
 
+#if JVET_L0428_DQP_SEP_TREE
+  if (partitioner.chType == CHANNEL_TYPE_CHROMA)
+  {
+    return;
+  }
+#endif
+
   if( bKeepCtx && partitioner.currDepth != cs.pps->getMaxCuDQPDepth() )
   {
     return;

source/Lib/EncoderLib/EncModeCtrl.cpp

@@ -948,8 +948,14 @@ void EncModeCtrlMTnoRQT::initCULevel( Partitioner &partitioner, const CodingStru
   int baseQP = cs.baseQP;
   if( m_pcEncCfg->getUseAdaptiveQP() )
   {
-    baseQP = Clip3( -cs.sps->getQpBDOffset( CHANNEL_TYPE_LUMA ), MAX_QP, baseQP + xComputeDQP( cs, partitioner ) );
+#if JVET_L0428_DQP_SEP_TREE
+    if (partitioner.chType == CHANNEL_TYPE_LUMA || !cs.slice->isIRAP())
+    {
+      baseQP = Clip3(-cs.sps->getQpBDOffset(CHANNEL_TYPE_LUMA), MAX_QP, baseQP + xComputeDQP(cs, partitioner));
+    }
+#endif
   }
+  
   int minQP = baseQP;
   int maxQP = baseQP;