Opened 5 years ago

Closed 4 years ago

#761 closed defect (fixed)

Incorrect conditions for checking different CTUs between the positions (xQg-1, yQg) and (xCb, yCb) in section 8.7.1

Reported by: moonmo.koo Owned by:
Priority: minor Milestone:
Component: spec Version: VVC D7 vE
Keywords: Cc: ksuehring, bbross, XiangLi, fbossen, jvet@…

Description

In the section 8.7.1 (Derivation process for quantization parameters) in the current VVC spec text, the following conditions can be found, which check whether or not two positions, (xQg-1, yQg) and (xCb, yCb), lie in different CTUs:

......

The CTB containing the luma coding block covering the luma location ( xQg − 1, yQg ) is not equal to the CTB containing the current luma coding block at ( xCb, yCb ), i.e. '''all of the following conditions are true''':
– ( xQg − 1 )  >>  CtbLog2SizeY is not equal to ( xCb )  >>  CtbLog2SizeY
– ( yQg )  >>  CtbLog2SizeY is not equal to ( yCb )  >>  CtbLog2SizeY

......

The CTB containing the luma coding block covering the luma location ( xQg, yQg − 1 ) is not equal to the CTB containing the current luma coding block at ( xCb, yCb ), i.e. '''all of the following conditions are true''':
– ( xQg )  >>  CtbLog2SizeY is not equal to ( xCb )  >>  CtbLog2SizeY
– ( yQg − 1 )  >>  CtbLog2SizeY is not equal to ( yCb )  >>  CtbLog2SizeY

......

It seems that "all of the following conditions" should be replaced by "any of the following conditions" for correct checking.

Change history (2)

comment:1 Changed 5 years ago by delagrangep

Good catch. Agreed.

comment:2 Changed 4 years ago by bbross

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

Thanks for reporting!

This is fixed in JVET-Q2001-v3.

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