Opened 10 years ago

Closed 5 years ago

# Undefined variable in Derivation process for collocated motion vectors

Reported by: Owned by: laurent.birtz@… minor D10 Text D10 (L1003) v33 bbross, wjhan, jct-vc@…

### Description

In "Derivation process for collocated motion vectors":

Inputs to this process are:

• a reference index refIdxLX, with X being 0 or 1.

The arrays predFlagLXCol[ x ][ y ], mvLXCol[ x ][ y ], and refIdxLXCol[ x ][ y ] are set equal to the corresponding arrays of the collocated picture specified by colPic, PredFlagLX[ x ][ y ], MvLX[ x ][ y ], and RefIdxLX[ x ][ y ], respectively, with X being the value of X this process is invoked for.

If predFlagL0Col[ xColPb ][ yColPb ] is equal to 0, ...

Problem:

If the process is invoked with refIdxL1, then X=1 and predFlagL0Col isn't defined since predFlagLXCol is assigned only for "X being the value of X this process is invoked for".

Is my understanding correct?

### comment:1 Changed 10 years ago by DefaultCC Plugin

• Cc bbross wjhan jct-vc@… added

### comment:2 Changed 10 years ago by yk

I think you are right and changing

The arrays predFlagLXCol[ x ][ y ], mvLXCol[ x ][ y ], and refIdxLXCol[ x ][ y ] are set equal to the corresponding arrays of the collocated picture specified by colPic, PredFlagLX[ x ][ y ], MvLX[ x ][ y ], and RefIdxLX[ x ][ y ], respectively, with X being the value of X this process is invoked for.

to

The arrays predFlagL0Col[ x ][ y ], mvL0Col[ x ][ y ], and refIdxL0Col[ x ][ y ] are set equal to PredFlagL0[ x ][ y ], MvL0[ x ][ y ], and RefIdxL0[ x ][ y ], respectively, of the collocated picture specified by colPic, and the arrays predFlagL1Col[ x ][ y ], mvL1Col[ x ][ y ], and refIdxL1Col[ x ][ y ] are set equal to PredFlagL1[ x ][ y ], MvL1[ x ][ y ], and RefIdxL1[ x ][ y ], respectively, of the collocated picture specified by colPic..

should resolve this issue.

BR, YK

### comment:3 Changed 5 years ago by bbross

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

Fixed in the 2016/12 release of the HEVC specification.

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