Opened 5 years ago

Closed 5 years ago

#568 closed defect (fixed)

RPR - Sub-PU Grouping

Reported by: bheng Owned by:
Priority: minor Milestone: VTM-7.0
Component: VTM Version: VTM-6.1
Keywords: Cc: ksuehring, XiangLi, fbossen, jvet@…

Description

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.

Change history (2)

comment:1 Changed 5 years ago by bheng

Potential fixes for this issue are available in the following merge request:

https://vcgit.hhi.fraunhofer.de/jvet/VVCSoftware_VTM/merge_requests/997

comment:2 Changed 5 years ago by XiangLi

  • Milestone set to VTM-7.0
  • Resolution set to fixed
  • Status changed from new to closed
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