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
comment:2 Changed 5 years ago by XiangLi
- Milestone set to VTM-7.0
- Resolution set to fixed
- Status changed from new to closed
Potential fixes for this issue are available in the following merge request:
https://vcgit.hhi.fraunhofer.de/jvet/VVCSoftware_VTM/merge_requests/997