Opened 8 years ago

Closed 8 years ago

#69 closed defect (fixed)

Missing of DcVal process and unclear DcOffset usage

Reported by: Tomohiro Ikai Owned by: tech
Priority: minor Component: 3D-HEVC text
Version: 3D-HEVC Draft Text 4 Keywords: DLT, SDC
Cc: tech, jct-3v@…

Description

In I.8.4.4.3 (I.8.4.4.3 Segmental depth intra coding process) in 3D-HEVC Draft Text 4 (H1001_v2), dcPred is derived but not used. It seems dcPred related process for recSamples is missing.

The fix is not clear but the attached H1001_v2_opt1 may help.

To me, the DcOffset usage is not clear in the following points. So the editorial improvement and some fix is to be desired.

(1) In SDC, DcOffset is not added to predSamples in I.8.4.4.2.9 but it is added in I.8.4.4.3. The reason why we should have two DcOffset related subclause is not clear to me. If we uses I.8.4.4.2.9 in both cases, the text can be much clear (See H1001_v2_opt2)

(2) In SDC, the variable DcVal is derived and used. But the derivation of DcVal is not clear. Specifically, When SDC is on, dcOffsetAvailFlag is false. Then DcOffset is not used both in DLT on case and in DLT off case. But when DLT is on, possibly we should add DcOffset before Idx2DepthValue[] (dcOffsetAvail should be true in this part?).

(3) DLT handling is separately specified in I.8.4.4.2.9 and I.8.4.4.3. That is difficult to understand so it should be specified either in I.8.4.4.3 or in I.8.4.4.2.9.

(4) If predModeIntra is not equal to INTRA_DMM_WFULL or INTRA_DMM_CPREDTEX, dcPred[0] is derived. But it is unclear whther DcOffset should be added in this case.

Attachments (1)

TK69.zip (181.2 KB) - added by Tomohiro Ikai 8 years ago.

Download all attachments as: .zip

Change history (4)

comment:1 Changed 8 years ago by DefaultCC Plugin

  • Cc tech jct-3v@… added

Changed 8 years ago by Tomohiro Ikai

comment:2 Changed 8 years ago by tech

  • Version set to 3D-HEVC Draft Text 4

comment:3 Changed 8 years ago by tech

  • Resolution set to fixed
  • Status changed from new to closed
Note: See TracTickets for help on using tickets.

This list contains all users that will be notified about changes made to this ticket.

These roles will be notified: Reporter, Owner, Subscriber, Participant

  • Gerhard Tech(Owner, Subscriber, Participant, Always)
  • jct-3v@…(Subscriber)
  • Karsten Suehring(Always)
  • Tomohiro Ikai(Reporter)