Opened 5 years ago

Closed 5 weeks ago

#1067 closed defect (wontfix)

mismatch between HEVC text and HM reference software

Reported by: sier Owned by:
Priority: minor Milestone: HM-10.1
Component: Text Version: D10 (L1003) v33
Keywords: Cc: bbross, wjhan, jct-vc@…

Description

Low-delay checking process is required for TMVP derivation. The process is carried out by comparing the POC values of current picture and its reference pictures.

In HEVC text, the low-delay checking process is specified in the section of TMVP derivation (i.e. 8.5.3.2.8 Derivation process for collocated motion vectors), which means the low-delay checking process is done at block-level.

However the low-delay checking process is performed at slice-level in HM reference software, where a low-delay flag is firstly determined at slice-level and then used in TMVP derivation.

It seems the low-delay checking at block-level specified in HEVC text is not reasonable for practical design, since the low-delay checking process is only based on POC values, instead of any block-level information, and meanwhile the block-level low-delay checking increase complexity. Hence alignment with HM reference software is suggested for consideration.

Change History (2)

comment:1 Changed 5 years ago by DefaultCC Plugin

  • Cc bbross wjhan jct-vc@… added

comment:2 Changed 5 weeks ago by bbross

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

Although the derivation process for collocated motion vectors is specified at the block level, performing aspects of this process at the picture level is also possible without altering the output of this process.

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  • Benjamin Bross(Subscriber, Participant)
  • David Flynn(Always)
  • jct-vc@…(Subscriber)
  • Karl Sharman(Always)
  • Karsten Suehring(Always)
  • sier(Reporter)
  • Woo-Jin Han(Subscriber)