In MR 1361, intra chroma minQT size are configured in chroma samples and...

In MR 1361, intra chroma minQT size are configured in chroma samples and converted in luma samle units in software, change the equation to align with the change; Added notes about the MinQTChromaISlice setting in software manual

doc/software-manual.tex

@@ -1204,6 +1204,11 @@ Defines the initial maximum depth of the multi-type tree in dual tree for luma c
 %\ShortOption{\None} &
 \Default{4} &
 Defines the initial minimum size of the quad tree in dual tree for chroma components.
+
+Note: this size is defined in chroma sample unit in configuration, and it is converted
+into luma sample unit according to the horizontal chroma subsampling ratio when applied
+in the software. In chroma format 4:2:2 case, this value shall be set to the value of
+the height of minimum chroma QT node in chroma samples.
 \\
 
 \Option{MinQTISlice} &

source/Lib/CommonLib/UnitPartitioner.cpp

@@ -391,12 +391,9 @@ void QTBTPartitioner::canSplit( const CodingStructure &cs, bool& canNo, bool& ca
   // don't allow QT-splitting below a BT split
   if( lastSplit != CTU_LEVEL && lastSplit != CU_QUAD_SPLIT ) canQt = false;
 #if JVET_Q0471_CHROMA_QT_SPLIT_ON_HEIGHT
-#if JVET_Q0438_MONOCHROME_BUGFIXES
-  SizeType side = (chType == CHANNEL_TYPE_CHROMA) ? areaC->height : area.height;
-#else
-  SizeType side = chType == CHANNEL_TYPE_CHROMA ? areaC.height : area.height;
-#endif
-  if (side <= minQtSize)                                     canQt = false;
+  // minQtSize is in luma samples unit
+  const unsigned minQTThreshold = minQtSize >> ((int) getChannelTypeScaleX(CHANNEL_TYPE_CHROMA, area.chromaFormat) - (int) getChannelTypeScaleY(CHANNEL_TYPE_CHROMA, area.chromaFormat));
+  if( area.width <= minQTThreshold )                         canQt = false;
 #else
   if( area.width <= minQtSize )                              canQt = false;
 #endif
@@ -574,8 +571,9 @@ PartSplit QTBTPartitioner::getImplicitSplit( const CodingStructure &cs )
 #endif
     const unsigned minQtSize  = cs.pcv->getMinQtSize( *cs.slice, chType );
 #if JVET_Q0471_CHROMA_QT_SPLIT_ON_HEIGHT
-    SizeType   side           = chType == CHANNEL_TYPE_CHROMA ? currArea().Cb().height : area.height;
-    const bool isQtAllowed    = side > minQtSize && currBtDepth == 0;
+    // minQtSize is in luma samples unit
+    const unsigned minQTThreshold = minQtSize >> ((int) getChannelTypeScaleX(CHANNEL_TYPE_CHROMA, area.chromaFormat) - (int) getChannelTypeScaleY(CHANNEL_TYPE_CHROMA, area.chromaFormat));
+    const bool isQtAllowed    = area.width > minQTThreshold && currBtDepth == 0;
 #else
     const bool isQtAllowed    = area.width >  minQtSize && area.height >  minQtSize && currBtDepth == 0;
 #endif