Opened 4 years ago

Closed 4 years ago

Unused filter in CCLM

Reported by: Owned by: lingli0 minor spec ksuehring, bbross, XiangLi, fbossen, jvet@…

Description

In VVC Draft8 vE, down-sample F4 is defined when either SubWidthC or SubHeightC is equal to 2. However, F4 is only used when both SubWidthC and SubHeightC are equal to 2. It is suggested to remove equation 369. Note that, this aspect is also pointed out in JVET-R0471.

– The one-dimensional filter coefficients array F1 and F2, and the 2-dimensional filter coefficients arrays F3 and F4 are specified as follows.
F1[ 0 ] = 2, F1[ 1 ] = 0 (361)
F2[ 0 ] = 1, F2[ 1 ] = 2, F2[ 2 ] = 1 (362)
F3[ i ][ j ] = F4[ i ][ j ] = 0, with i = 0..2, j = 0..2 (363)
– If both SubWidthC and SubHeightC are equal to 2, the following applies:
F1[ 0 ] = 1, F1[ 1 ] = 1 (364)
F3[ 0 ][ 1 ] = 1, F3[ 1 ][ 1 ] = 4, F3[ 2 ][ 1 ] = 1, F3[ 1 ][ 0 ] = 1, F3[ 1 ][ 2 ] = 1 (365)
F4[ 0 ][ 1 ] = 1, F4[ 1 ][ 1 ] = 2, F4[ 2 ][ 1 ] = 1 (366)
F4[ 0 ][ 2 ] = 1, F4[ 1 ][ 2 ] = 2, F4[ 2 ][ 2 ] = 1 (367)
– Otherwise, the following applies:
F3[ 1 ][ 1 ] = 8 (368)
-F4[ 0 ][ 1 ] = 2, F4[ 1 ][ 1 ] = 4, F4[ 2 ][ 1 ] = 2, (369)

comment:1 Changed 4 years ago by bbross

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

Good catch, thanks!

This is fixed in vB of D9, ie. JVET-R2001-v11.

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