id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
568	RPR - Sub-PU Grouping	bheng		"In the function InterPrediction::xSubPuMC( ), the optimization used to group identical SBTMVP motion vector blocks together into larger blocks for interpolation cannot be used with RPR.

RPR generates different results when it is applied to a small (8x8) block versus a larger combined block.  Therefore, the optimization mentioned above will change the results.

Either the optimization needs to be removed, or the following code needs a check for scaled reference pictures, so that the grouping is not applied in this case.

        if (laterMi == curMi)
        {
          length += secStep;
        }
        else
        {
          break;
        }

Note that the PU::isRefPicSameSize( ) function doesn’t seem to work for this purpose, since I believe pu.refIdx[0/1] are set based on the default SBTMVP vector.  Even if this default vector doesn’t require scaling, one of the 8x8 sub-blocks might.
"	defect	closed	minor	VTM-7.0	VTM	VTM-6.1	fixed		ksuehring XiangLi fbossen jvet@…