Opened 12 years ago

Closed 12 years ago

#928 closed defect (fixed)

Wrong picture marking information usage in derivation of motion vector components

Reported by: mcoban Owned by:
Priority: minor Milestone: HM-9.2
Component: HM Version: HM-9.1
Keywords: Cc: fbossen, ksuehring, davidf, jct-vc@…

Description

In HM during the motion information derivation process, wrong picture marking information is for collocated partition's reference frame. HM uses collocated partition's current picture marking information (short term or long term) instead of its picture marking information at the time of its usage as a reference frame as specified in section 8.5.3.1 of the latest specification draft. The issue shows up when TMVP is enabled with long term reference pictures. Attached patch addresses this problem.

In High Efficiency Video Coding (HEVC) text specification draft 9 section 8.5.3.1

8.5.3.1 Derivation process for motion vector components and reference indices
...
The function LongTermRefPic( nPic, nPb, refIdx, LX ), with X being either 0 or 1, is defined as follows. If the picture with index refIdx from reference picture list LX of the slice containing prediction block nPb in the picture nPic was marked as "used for long term reference" at the time when nPic was the current picture, LongTermRefPic( nPic, nPb, refIdx, LX ) is equal to 1; otherwise LongTermRefPic( nPic, nPb, refIdx, LX ) is equal to 0.
...

Attachments (2)

colref_fix.patch​ (5.8 KB) - added by mcoban 12 years ago.
colref_fix_v2.patch​ (6.1 KB) - added by mcoban 12 years ago.

Download all attachments as: .zip

Change History (7)

comment:1 Changed 12 years ago by DefaultCC Plugin

  • Cc fbossen ksuehring davidf jct-vc@… added

Changed 12 years ago by mcoban

comment:2 Changed 12 years ago by fbossen

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

Fixed in r3169

comment:3 Changed 12 years ago by fbossen

  • Resolution fixed deleted
  • Status changed from closed to reopened

Provided patch seems to introduce encoder/decoder mismatches in the absence of long-term reference pictures
r3169 undone in r3197

comment:4 Changed 12 years ago by mcoban

Missing picture marking info update in copySliceInfo() was causing the encoder/decoder mistmatches under multiple slice configuration condition with the previous patch. This issue is addressed in the attached patch.

Changed 12 years ago by mcoban

comment:5 Changed 12 years ago by fbossen

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

Fixed in r3204

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  • David Flynn(Subscriber)
  • Frank Bossen(Subscriber, Participant)
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  • Karsten Suehring(Subscriber, Always)
  • Muhammed Coban(Reporter, Participant)