Opened 8 years ago

Closed 8 years ago

#903 closed enhancement (fixed)

Ambiguity in binarization of coeff_abs_level_remaining

Reported by: peterderivaz Owned by: bbross
Priority: minor Milestone: D10
Component: Text Version: D10 (L1003) v2
Keywords: Cc: bbross, wjhan, jct-vc@…

Description

In section 9.2.2.8 Binarization process for coeff_abs_level_remaining the text reads:

cLastAbsLevel is set equal to baseLevel + coeff_abs_level_remaining[ n + 1 ]

However, by the time coeff_abs_level_remaining[n] is being decoded, baseLevel has been reassigned a new value, so cLastAbsLevel is not necessarily the same as the absolute value of the last TransCoeffLevel.

The full text reads:

cLastAbsLevel is set equal to baseLevel + coeff_abs_level_remaining[ n + 1 ] and cLastRiceParam is set equal to the value of cRiceParam that has been derived during the invocation of the binarization process as specified in this subclause for the syntax element coeff_abs_level_remaining[ n + 1 ] of the same transform block.

so I assume that the intention is that the value for both cLastRiceParam and baseLevel should be taken from the previous invocation.

Perhaps the wording could be improved?


Change History (6)

comment:1 Changed 8 years ago by DefaultCC Plugin

  • Cc bbross wjhan jct-vc@… added

comment:2 Changed 8 years ago by bbross

  • Version changed from D9 (K1003) v11 to D10 (L1003) v1

comment:3 Changed 8 years ago by bbross

  • Milestone set to D10

comment:4 Changed 8 years ago by bbross

  • Version changed from D10 (L1003) v1 to D10 (L1003) v2

comment:5 Changed 8 years ago by bbross

Improved the wording as follows:

Input to this process is a request for a binarization for the syntax element coeff_abs_level_remaining[ n ], the current sub-block scan index i, and baseLevel.

Output of this process is the binarization of the syntax element.

The variables cLastAbsLevel and cLastRiceParam are derived as follows:

– If this process is invoked for the first time for the current sub-block scan index i, cLastAbsLevel and cLastRiceParam are set equal to 0.

– Otherwise (this process is not invoked for the first time for the current sub-block scan index i), cLastAbsLevel is set equal to the value of cAbsLevel and cLastRiceParam is set equal to the value of cRiceParam that have both been derived during the last invocation of the binarization process for the syntax element coeff_abs_level_remaining as specified in this subclause.

The variable cAbsLevel is set equal to baseLevel + coeff_abs_level_remaining[ n ].

comment:6 Changed 8 years ago by bbross

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

This is fixed in current version v28.

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  • Benjamin Bross(Owner, Subscriber, Participant)
  • jct-vc@…(Subscriber)
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  • Karsten Suehring(Always)
  • Peter de Rivaz(Reporter)
  • Woo-Jin Han(Subscriber)