M0192 modifications - affine chroma MV is average of two luma sub-block MVs...

M0192 modifications - affine chroma MV is average of two luma sub-block MVs instead of four; MV rounding is unified

source/Lib/CommonLib/InterPrediction.cpp

@@ -755,11 +755,23 @@ void InterPrediction::xPredAffineBlk( const ComponentID& compID, const Predictio
       else
       {
 #if JVET_M0265_MV_ROUNDING_CLEANUP
+#if JVET_M0192_AFF_CHROMA_SIMPL
+        Mv curMv = m_storedMv[((h << iScaleY) / AFFINE_MIN_BLOCK_SIZE) * MVBUFFER_SIZE + ((w << iScaleX) / AFFINE_MIN_BLOCK_SIZE)] +
+          m_storedMv[((h << iScaleY) / AFFINE_MIN_BLOCK_SIZE + 1)* MVBUFFER_SIZE + ((w << iScaleX) / AFFINE_MIN_BLOCK_SIZE + 1)];
+        roundAffineMv(curMv.hor, curMv.ver, 1);
+#else
         Mv curMv = m_storedMv[((h << iScaleY) / AFFINE_MIN_BLOCK_SIZE) * MVBUFFER_SIZE + ((w << iScaleX) / AFFINE_MIN_BLOCK_SIZE)] +
           m_storedMv[((h << iScaleY) / AFFINE_MIN_BLOCK_SIZE + 1)* MVBUFFER_SIZE + ((w << iScaleX) / AFFINE_MIN_BLOCK_SIZE)] +
           m_storedMv[((h << iScaleY) / AFFINE_MIN_BLOCK_SIZE)* MVBUFFER_SIZE + ((w << iScaleX) / AFFINE_MIN_BLOCK_SIZE + 1)] +
           m_storedMv[((h << iScaleY) / AFFINE_MIN_BLOCK_SIZE + 1)* MVBUFFER_SIZE + ((w << iScaleX) / AFFINE_MIN_BLOCK_SIZE + 1)];
         roundAffineMv(curMv.hor, curMv.ver, 2);
+#endif
+#else
+#if JVET_M0192_AFF_CHROMA_SIMPL
+        Mv curMv = m_storedMv[((h << iScaleY) / AFFINE_MIN_BLOCK_SIZE) * MVBUFFER_SIZE + ((w << iScaleX) / AFFINE_MIN_BLOCK_SIZE)] +
+          m_storedMv[((h << iScaleY) / AFFINE_MIN_BLOCK_SIZE + 1)* MVBUFFER_SIZE + ((w << iScaleX) / AFFINE_MIN_BLOCK_SIZE + 1)];
+        curMv.setHor(curMv.getHor() >= 0 ? ((curMv.getHor() + 1) >> 1) : -((-curMv.getHor() + 1) >> 1));
+        curMv.setVer(curMv.getVer() >= 0 ? ((curMv.getVer() + 1) >> 1) : -((-curMv.getVer() + 1) >> 1));
 #else
         Mv curMv = (m_storedMv[((h << iScaleY) / AFFINE_MIN_BLOCK_SIZE) * MVBUFFER_SIZE + ((w << iScaleX) / AFFINE_MIN_BLOCK_SIZE)] +
           m_storedMv[((h << iScaleY) / AFFINE_MIN_BLOCK_SIZE + 1)* MVBUFFER_SIZE + ((w << iScaleX) / AFFINE_MIN_BLOCK_SIZE)] +
@@ -767,6 +779,7 @@ void InterPrediction::xPredAffineBlk( const ComponentID& compID, const Predictio
           m_storedMv[((h << iScaleY) / AFFINE_MIN_BLOCK_SIZE + 1)* MVBUFFER_SIZE + ((w << iScaleX) / AFFINE_MIN_BLOCK_SIZE + 1)] +
           Mv(2, 2));
         curMv.set(curMv.getHor() >> 2, curMv.getVer() >> 2);   
+#endif
 #endif
         if (sps.getWrapAroundEnabledFlag())
         {

source/Lib/CommonLib/TypeDef.h

@@ -50,6 +50,8 @@
 #include <assert.h>
 #include <cassert>
 
+#define JVET_M0192_AFF_CHROMA_SIMPL                       1 // Affine chroma MV derivation simplification and rounding unification
+
 #define JVET_M0116_ATMVP_LEFT_NB_FOR_OFFSET               1 // Only use left neighbor for ATMVP offset derivation, from M0273, M0240, M0116, M0338, M0204
 
 #define JVET_M0063_BDOF_FIX                               1 // BDOF bitdepth bugfix
@@ -79,7 +81,6 @@
 
 #define JVET_M0142_CCLM_COLLOCATED_CHROMA                 1 // Adding support for chroma sample location type 2 in CCLM
 
-
 #define JVET_M0479_18BITS_MV_CLIP                         1
 
 #define JVET_M0497_FAST_DST7                              1