Opened 5 years ago

Closed 5 years ago

#626 closed defect (fixed)

Wrong derivation condition of modified qP, rectNonTsFlag, bdShift in 8.7.3 Scaling process for transform coefficients

Reported by: tsukuba.takeshi Owned by:
Priority: minor Milestone:
Component: spec Version:
Keywords: Cc: ksuehring, bbross, XiangLi, fbossen, jvet@…

Description

In current spec text D7 v10, the modified qP, rectNonTsFlag,and bdShift are derived as follows:

The quantization parameter qP is modified and the variables rectNonTsFlag, and bdShift are derived as follows:
–If transform_skip_flag[ xTbY ][ yTbY ][ cIdx ] is equal to 0, the following applies:

qP = qP − ( cu_act_enabled_flag[ xTbY ][ yTbY ] ? 5 : 0 ) (8-938)
rectNonTsFlag = 0 (8-939)
bdShift = 10 (8-940)

–Otherwise, if transform_skip_flag[ xTbY ][ yTbY ][ cIdx ] is equal to 1, the following applies:

qP = Max( QpPrimeTsMin, qP ) − ( cu_act_enabled_flag[ xTbY ][ yTbY ] ? 5 : 0 ) (8-941)
rectNonTsFlag = ( ( ( Log2( nTbW ) + Log2( nTbH ) ) & 1 ) = = 1 (8-942)
bdShift = BitDepth + ( rectNonTsFlag ? 1 : 0 ) + ( ( Log2( nTbW ) + Log2( nTbH ) ) / 2 ) − 5 + pic_dep_quant_enabled_flag (8-943)

However, as implemented in VTM SW, it should be as bellow:
The quantization parameter qP is modified and the variables rectNonTsFlag, and bdShift are derived as follows:
–If transform_skip_flag[ xTbY ][ yTbY ][ cIdx ] is equal to 10, the following applies:

qP = Max(QpPrimeTsMin, qP )− ( cu_act_enabled_flag[ xTbY ][ yTbY ] ? 5 : 0 ) (8-938)
rectNonTsFlag = 0 (8-939)
bdShift = 10 (8-940)

–Otherwise, if transform_skip_flag[ xTbY ][ yTbY ][ cIdx ] is equal to 01, the following applies:

qP = Max( QpPrimeTsMin, qP ) qP − ( cu_act_enabled_flag[ xTbY ][ yTbY ] ? 5 : 0 ) (8-941)
rectNonTsFlag = ( ( ( Log2( nTbW ) + Log2( nTbH ) ) & 1 ) = = 1 (8-942)
bdShift = BitDepth + ( rectNonTsFlag ? 1 : 0 ) + ( ( Log2( nTbW ) + Log2( nTbH ) ) / 2 ) − 5 + pic_dep_quant_enabled_flag (8-943)

Change history (1)

comment:1 Changed 5 years ago by bbross

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

Thanks for reporting.

This will be fixed JVET-P2001-vB.

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