L0053_L0272_DM: Modified chroma DM

source/Lib/CommonLib/TypeDef.h

@@ -51,6 +51,7 @@
 #include <cassert>
 
 #define JVET_L0553_FIX_INITQP                             1
+#define JVET_L0053_L0272_DM                               1 // use center position of luma block to derive DM
 
 #define JVET_L0147_ALF_SUBSAMPLED_LAPLACIAN               1 // Subsampled Laplacian calculation
 

source/Lib/CommonLib/UnitTools.cpp

@@ -390,7 +390,13 @@ void PU::getIntraChromaCandModes( const PredictionUnit &pu, unsigned modeList[NU
     modeList[4] = LM_CHROMA_IDX;
     modeList[5] = DM_CHROMA_IDX;
 
+#if JVET_L0053_L0272_DM
+    Position topLeftPos = pu.blocks[pu.chType].lumaPos();
+    Position refPos = topLeftPos.offset( pu.blocks[pu.chType].width, pu.blocks[pu.chType].height );
+    const PredictionUnit *lumaPU = CS::isDualITree( *pu.cs ) ? pu.cs->picture->cs->getPU( refPos, CHANNEL_TYPE_LUMA ) : &pu;
+#else
     const PredictionUnit *lumaPU = CS::isDualITree( *pu.cs ) ? pu.cs->picture->cs->getPU( pu.blocks[pu.chType].lumaPos(), CHANNEL_TYPE_LUMA ) : &pu;
+#endif
     const uint32_t lumaMode = lumaPU->intraDir[CHANNEL_TYPE_LUMA];
     for( int i = 0; i < 4; i++ )
     {
@@ -484,7 +490,13 @@ uint32_t PU::getFinalIntraMode( const PredictionUnit &pu, const ChannelType &chT
 
   if( uiIntraMode == DM_CHROMA_IDX && !isLuma( chType ) )
   {
+#if JVET_L0053_L0272_DM
+    Position topLeftPos = pu.blocks[pu.chType].lumaPos();
+    Position refPos = topLeftPos.offset( pu.blocks[pu.chType].width, pu.blocks[pu.chType].height );
+    const PredictionUnit &lumaPU = CS::isDualITree( *pu.cs ) ? *pu.cs->picture->cs->getPU( refPos, CHANNEL_TYPE_LUMA ) : *pu.cs->getPU( topLeftPos, CHANNEL_TYPE_LUMA );
+#else
     const PredictionUnit &lumaPU = CS::isDualITree( *pu.cs ) ? *pu.cs->picture->cs->getPU( pu.blocks[chType].lumaPos(), CHANNEL_TYPE_LUMA ) : *pu.cs->getPU( pu.blocks[chType].lumaPos(), CHANNEL_TYPE_LUMA );
+#endif
     uiIntraMode = lumaPU.intraDir[0];
   }
   if( pu.chromaFormat == CHROMA_422 && !isLuma( chType ) )