Opened 4 months ago

Last modified 4 months ago

#342 new defect

CTU boundary position not computed correctly for Chroma deblocking

Reported by: AnandMeher Owned by:
Priority: minor Milestone:
Component: VTM Version: VTM-5.0
Keywords: Longer tap deblocking for Chroma Cc: ksuehring, XiangLi, fbossen, jvet@…

Description

For the Chroma longer tap deblocking, longer tap filter is currently switched off at the horizontal CTU boundaries to reduce line buffer.

In the VTM-5.0 code, in function xEdgeFilterChroma, the position for the horizontal CTU boundary seems to be computed incorrectly, which is as follows:
pos.y % cuP.slice->getSPS()->getCTUSize() == 0
which does not take into account the Chroma re-scaling based on the Chroma format.

A possible fix could be as follows:
(pos.y % (cuP.slice->getSPS()->getCTUSize() >> ::getComponentScaleX(COMPONENT_Cb, nChromaFormat)) == 0)

Change history (1)

comment:1 Changed 4 months ago by AnandMeher

After further investigation, it seems the implementation of VTM-5.0 is correct as "pos.y" variable is already re-scaled. Therefore this ticket can be closed.

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