Opened 10 years ago

Closed 10 years ago

#180 closed defect (fixed)

HM-3.1 bug: Previous QP is not correct

Reported by: hao Owned by:
Priority: critical Milestone:
Component: HM Version:
Keywords: Cc: fbossen, ksuehring, davidf, jct-vc@…

Description

According to the decision at the Geneva meeting, new QP predictor for WD3 is introduced into HM-3.1, with the macro SUB_LCU_DQP. The predictor is defined as follows.

  1. Use left negihbor (of upper-left corner of currentCU) if available
  2. Otherwise, use previous in scan order.

However, the current implementation fails to correctly get previous QP in scan order.
TComDataCU::m_hLastCodedQP representing the previous QP is not set to the real previous QP but set to the reference QP when encoding/decoding the current QP. As a result, correct predicted QP cannot be obtained at the first CU in the left-most LCU.
I believe the correct procedure is that TComDataCU::m_hLastCodedQP is set to the current QP when finishing encoding/decoding process of CU's whose depth is equal to or less than MaxCuDQPDepth.

In addition, QP of CU's coded as PCM is not correctly set.

Attachments (2)

source-Fix180.zip (35.0 KB) - added by hao 10 years ago.
Source code for fix of this issue (old version is not correct and therefore replaced)
fix180.patch (5.3 KB) - added by hao 10 years ago.
Same fix in patch format.

Download all attachments as: .zip

Change History (6)

Changed 10 years ago by hao

Source code for fix of this issue (old version is not correct and therefore replaced)

Changed 10 years ago by hao

Same fix in patch format.

comment:1 Changed 10 years ago by fbossen

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

fixed in r1018

comment:2 Changed 9 years ago by davidf

  • Component set to HM

Updating component after adding WD (Text) tickets

comment:3 Changed 9 years ago by davidf

  • Cc fbossen ksuehring davidf added

comment:4 Changed 9 years ago by davidf

  • Cc jct-vc@… added
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These roles will be notified: Reporter, Owner, Subscriber, Participant

  • David Flynn(Subscriber, Participant)
  • Frank Bossen(Subscriber, Participant)
  • Hirofumi Aoki(Reporter)
  • jct-vc@…(Subscriber)
  • karl.sharman@…(Always)
  • Karsten Suehring(Subscriber, Always)