Opened 4 weeks ago

Closed 4 weeks ago

#684 closed defect (invalid)

Misalignment between VTM and VVC draft for PDPC

Reported by: hongbin Owned by:
Priority: minor Milestone: VVC D7 vC
Component: spec Version: VVC D7 vC
Keywords: Cc: ksuehring, bbross, XiangLi, fbossen, jvet@…

Description

In 8.4.5.2.14 Position-dependent intra prediction sample filtering process, nScale is calculated and is used.
In SW, PDPC is disabled when nScale is less than 0. However, in Spec, there is no such constraint, which is incorrect.

The variable nScale is derived as follows:
– If predModeIntra is greater than INTRA_ANGULAR50, nScale is set equal to Min( 2, Log2( nTbH ) − Floor( Log2( 3 * invAngle − 2 ) ) + 8 ), using invAngle as specified in clause 8.4.5.2.12.
– Otherwise, if predModeIntra is less than INTRA_ANGULAR18, nScale is set equal to Min( 2, Log2( nTbW ) − Floor( Log2( 3 * invAngle − 2 ) ) + 8 ), using invAngle as specified in clause 8.4.5.2.12.
– Otherwise, nSacle is set to ( ( Log2( nTbW ) + Log2( nTbH ) − 2 ) >> 2 ).

shall be changed to

The variable nScale is derived as follows:
– If predModeIntra is greater than INTRA_ANGULAR50, nScale is set equal to Min( 2, Log2( nTbH ) − Floor( Log2( 3 * invAngle − 2 ) ) + 8 ), using invAngle as specified in clause 8.4.5.2.12.
– Otherwise, if predModeIntra is less than INTRA_ANGULAR18, nScale is set equal to Min( 2, Log2( nTbW ) − Floor( Log2( 3 * invAngle − 2 ) ) + 8 ), using invAngle as specified in clause 8.4.5.2.12.
– Otherwise, nSacle is set to ( ( Log2( nTbW ) + Log2( nTbH ) − 2 ) >> 2 ).
If nScale is less than zero, this process is terminated.

Change history (3)

comment:1 Changed 4 weeks ago by bbross

  • Version set to VVC D7 vC

comment:2 Changed 4 weeks ago by fbossen

I don't see a mismatch here. Both SW and text yield the same result when nScale is less than zero: the prediction array predSamples is not modified.

comment:3 Changed 4 weeks ago by bbross

  • Resolution set to invalid
  • Status changed from new to closed
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