Opened 3 years ago

Last modified 3 years ago

#1312 new defect

H.265 official spec, 8.5.3.2.8 "Derivation process for collocated motion vectors", currPb instead of colPb.

Reported by: vlad Owned by:
Priority: major Milestone:
Component: Text Version: WD5 (G1103) d9
Keywords: Cc: bbross, wjhan, jct-vc@…

Description

Dear experts,

I think that there might be a bug in official H265 spec:
http://www.itu.int/rec/T-REC-H.265-201304-I
T-REC-H.265-201304-I!!PDF-E.pdf

Current wording is as follows:


Otherwise, the variable availableFlagLXCol is set equal to 1, refPicListCol[ refIdxCol ] is set to be the picture
with reference index refIdxCol in the reference picture list listCol of the slice containing prediction block
currPb in the picture colPic, and the following applies:

colPocDiff = DiffPicOrderCnt( colPic, refPicListCol[ refIdxCol ] ) (8-177)


In my opinion it should be:


Otherwise, the variable availableFlagLXCol is set equal to 1, refPicListCol[ refIdxCol ] is set to be the picture
with reference index refIdxCol in the reference picture list listCol of the slice containing prediction block
colPb in the picture colPic, and the following applies:

colPocDiff = DiffPicOrderCnt( colPic, refPicListCol[ refIdxCol ] ) (8-177)


Justification:
If Reference Picture List (refPicListCol[refIdxCol]) from colPic to be extracted from slice to which currPb belongs (slice which covers corresponding unit) it should be assured that given slice in colPic is not INTRA and it was only assured that slice to which colPb belongs is not INTRA by:

If colPb is coded in an intra prediction mode, both components of mvLXCol are set equal to 0 and
availableFlagLXCol is set equal to 0.
Otherwise Reference Picture List could be empty (in INTRA slice).

Wlodzimierz Lipert.

Change History (2)

comment:1 Changed 3 years ago by DefaultCC Plugin

  • Cc bbross wjhan jct-vc@… added

comment:2 Changed 3 years ago by vlad

JCTVC-R1013-v3
http://phenix.int-evry.fr/jct/doc_end_user/documents/18_Sapporo/wg11/JCTVC-R1013-v3.zip
8.5.3.2.9 "Derivation process for collocated motion vectors".
Same wording.

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