Opened 5 years ago
Last modified 5 years ago
#152 closed defect
Sub-PU TMVP can generate an invalid inter candidate — at Initial Version
| Reported by: | bheng | Owned by: | |
|---|---|---|---|
| Priority: | minor | Milestone: | |
| Component: | VTM | Version: | VTM-3.0 |
| Keywords: | Cc: | ksuehring, XiangLi, fbossen, jvet@… |
Description
In UnitTools.cpp, in the function getInterMergeSubPuMvpCand():
if (colMi.isInter ... )
{
for (unsigned currRefListId = 0; currRefListId < (bBSlice ? 2 : 1); currRefListId++)
{
RefPicList currRefPicList = RefPicList(currRefListId);
if (deriveScaledMotionTemporal(…))
{
…
}
}
}
else
{
intra coded, in this case, no motion vector is available for list 0 or list 1, so use default
…
}
The code above can generate a inter motion vector with no valid reference frame (all refIdx = -1).
Assume the first if() condition passes (i.e. colMi.isInter) and the second if() condition fails. For example, if the current slice is a P-slice and deriveScaledMotionTemporal() returns false for List0 because colMi contains only List1 motion, getCheckLDC()=0, and bAllowMirrorMV=0.
In this situation, the code above will never run the else( ) condition that assigns the default motion instead. An inter motion vector will be assigned with no valid reference index (refIdxL0=-1 and refIdxL1=-1).
