JVET-O0106: 4xN prediction regions for 1xN/2xN subblocks of ISP

source/Lib/CommonLib/CommonDef.h

@@ -213,6 +213,10 @@ static const int MAX_REF_LINE_IDX =                                 3; //highest
 static const int MRL_NUM_REF_LINES =                                3; //number of candidates in the array
 static const int MULTI_REF_LINE_IDX[4] =               { 0, 1, 3, 0 };
 
+#if JVET_O0106_ISP_4xN_PREDREG_FOR_1xN_2xN
+static const int PRED_REG_MIN_WIDTH =                               4;  // Minimum prediction region width for ISP subblocks
+#endif
+
 static const int NUM_LUMA_MODE =                                   67; ///< Planar + DC + 65 directional mode (4*16 + 1)
 static const int NUM_LMC_MODE =                                    1 + 2; ///< LMC + MDLM_T + MDLM_L
 static const int NUM_INTRA_MODE = (NUM_LUMA_MODE + NUM_LMC_MODE);

source/Lib/CommonLib/TypeDef.h

@@ -50,6 +50,8 @@
 #include <assert.h>
 #include <cassert>
 
+#define JVET_O0106_ISP_4xN_PREDREG_FOR_1xN_2xN            0 // JVET-O0106: use 4xN prediction regions for 1xN and 2xN subblocks
+
 #define JVET_O0315_RDPCM_INTRAMODE_ALIGN                  1 // JVET-O0200/O0205/O0296/O0342/O0463/O0542: Intra prediction mode alignment for BDPCM
 
 #define JVET_O0284_CONDITION_SMVD_MVDL1ZEROFLAG           1 // JVET-O0284: condition sym_mvd_flag on mvd_l1_zero_flag

source/Lib/CommonLib/UnitTools.cpp

@@ -4318,6 +4318,28 @@ bool CU::isSameSbtSize( const uint8_t sbtInfo1, const uint8_t sbtInfo2 )
     return false;
 }
 
+#if JVET_O0106_ISP_4xN_PREDREG_FOR_1xN_2xN
+bool CU::isPredRegDiffFromTB(const CodingUnit &cu, const ComponentID compID)
+{
+  return (compID == COMPONENT_Y)
+    && (cu.ispMode == VER_INTRA_SUBPARTITIONS &&
+      CU::isMinWidthPredEnabledForBlkSize(cu.blocks[compID].width, cu.blocks[compID].height)
+      );
+}
+bool CU::isMinWidthPredEnabledForBlkSize(const int w, const int h)
+{
+  return ((w == 8 && h > 4) || w == 4);
+}
+bool CU::isFirstTBInPredReg(const CodingUnit& cu, const ComponentID compID, const CompArea &area)
+{
+  return (compID == COMPONENT_Y) && cu.ispMode && ((area.topLeft().x - cu.Y().topLeft().x) % PRED_REG_MIN_WIDTH == 0);
+}
+void CU::adjustPredArea(CompArea &area)
+{
+  area.width = std::max<int>(PRED_REG_MIN_WIDTH, area.width);
+}
+#endif
+
 bool CU::isGBiIdxCoded( const CodingUnit &cu )
 {
   if( cu.cs->sps->getUseGBi() == false )

source/Lib/CommonLib/UnitTools.h

@@ -80,7 +80,12 @@ namespace CU
   bool hasNonTsCodedBlock             (const CodingUnit& cu);
   uint32_t getNumNonZeroCoeffNonTs         ( const CodingUnit& cu, const bool lumaFlag = true, const bool chromaFlag = true );
   uint32_t getNumNonZeroCoeffNonTsCorner8x8( const CodingUnit& cu, const bool lumaFlag = true, const bool chromaFlag = true );
-
+#if JVET_O0106_ISP_4xN_PREDREG_FOR_1xN_2xN
+  bool  isPredRegDiffFromTB(const CodingUnit& cu, const ComponentID compID);
+  bool  isFirstTBInPredReg(const CodingUnit& cu, const ComponentID compID, const CompArea &area);
+  bool  isMinWidthPredEnabledForBlkSize(const int w, const int h);
+  void  adjustPredArea(CompArea &area);
+#endif
   bool  isGBiIdxCoded                 (const CodingUnit& cu);
   uint8_t getValidGbiIdx              (const CodingUnit& cu);
   void  setGbiIdx                     (CodingUnit& cu, uint8_t uh);

source/Lib/DecoderLib/DecCu.cpp

@@ -186,6 +186,20 @@ void DecCu::xIntraRecBlk( TransformUnit& tu, const ComponentID compID )
   const uint32_t uiChFinalMode  = PU::getFinalIntraMode( pu, chType );
 
   //===== init availability pattern =====
+#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);
+      m_pcIntraPred->initIntraPatternChType(*tu.cu, areaPredReg);
+    }
+  }
+  else
+#endif
   m_pcIntraPred->initIntraPatternChType( *tu.cu, area);
 
   //===== get prediction signal =====
@@ -204,7 +218,18 @@ void DecCu::xIntraRecBlk( TransformUnit& tu, const ComponentID compID )
     }
     else
     {
-    m_pcIntraPred->predIntraAng( compID, piPred, pu );
+#if JVET_O0106_ISP_4xN_PREDREG_FOR_1xN_2xN
+      if (predRegDiffFromTB)
+      {
+        if (firstTBInPredReg)
+        {
+          PelBuf piPredReg = cs.getPredBuf(areaPredReg);
+          m_pcIntraPred->predIntraAng(compID, piPredReg, pu);
+        }
+      }
+      else
+#endif
+        m_pcIntraPred->predIntraAng(compID, piPred, pu);
     }
   }
   const Slice           &slice = *cs.slice;

source/Lib/EncoderLib/IntraSearch.cpp

@@ -1841,7 +1841,21 @@ void IntraSearch::xIntraCodingTUBlock(TransformUnit &tu, const ComponentID &comp
   PelBuf sharedPredTS( m_pSharedPredTransformSkip[compID], area );
   if( default0Save1Load2 != 2 )
   {
-    initIntraPatternChType( *tu.cu, area );
+#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);
 
     //===== get prediction signal =====
     if( compID != COMPONENT_Y && PU::isLMCMode( uiChFinalMode ) )
@@ -1859,7 +1873,18 @@ void IntraSearch::xIntraCodingTUBlock(TransformUnit &tu, const ComponentID &comp
       }
       else
       {
-      predIntraAng( compID, piPred, pu );
+#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);
       }
     }