Opened 4 years ago

Closed 4 years ago

#955 closed defect (fixed)

Redundant condition on DBF maxFilterLength derivation

Reported by: abe.kiyo Owned by:
Priority: minor Milestone: VVC D10
Component: spec Version: VVC D9 vB
Keywords: Cc: ksuehring, bbross, XiangLi, fbossen, jvet@…


In Derivation process of coding subblock boundary, there is the following description.

– Otherwise, if one or more of the following conditions are true:

– ( x + 4 ) is greater than or equal to nCbW,
– edgeTbFlags[ x − 4 ][ y ] is equal to 1,
– edgeTbFlags[ x + 4 ][ y ] is equal to 1,

the following applies:

maxFilterLengthPs[ x ][ y ] = 1 (1253)
maxFilterLengthQs[ x ][ y ] = 1 (1254)

x is always 8 grid potion inside the current coding block. The coding block size of subblock mode is always a multiple of 8. Therefore, it will never meet the first condition. I suggest the first condition should be removed. It is same for horizontal edges.

Change history (4)

comment:1 Changed 4 years ago by bbross

  • Milestone set to VVC D10
  • Version set to VVC D9 vB

comment:2 Changed 4 years ago by ZhipinDeng

The condition "( y + 4 ) is greater than or equal to nCbH" for deblocking EDGE_HOR in section is also redundant and should be deleted. Same reason, i.e., deblocking is applied at 8x8 grid for subblock boundaries thereby this condition would never hit.

comment:3 Changed 4 years ago by Kenneth

That’s correct. Those checks are redundant. Same applies to VTM.

comment:4 Changed 4 years ago by bbross

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

Will be fixed in JVET-S2001-vA.

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