Typos of filter coefficients array for CCLM

[chiaming]

In "8.4.5.2.13 Specification of INTRA_LT_CCLM, INTRA_L_CCLM and INTRA_T_CCLM intra prediction mode", filter coefficients arrays are defined as:

– The one-dimensional filter coefficients array F1 and F2, and the 2-dimensional filter coefficients arrays F3 and F4 are specified as follows.

F1[ i ] with i = 0..2 (8-160)
F2[ 0 ] = 1, F2[ 1 ] = 2, F2[ 2 ] = 1 (8 161)
F3[ i ][ j ] = F4[ i ][ j ] = 0, with i = 0..2, j = 0..2 (8-162)

– If both SubWidthC and SubHeightC are equal to 2, the following applies:

F1[ 0 ] = 1, F1[ 1 ] = 1 (8-163)
F3[ 0 ][ 1 ] = 1, F3[ 1 ][ 1 ] = 4, F2[ 2 ][ 1 ] = 1, F3[ 1 ][ 0 ] = 1, F3[ 1 ][ 2 ] = 1 (8-164)
F4[ 0 ][ 1 ] = 1, F4[ 1 ][ 1 ] = 2, F4[ 2 ][ 1 ] = 1 (8-165)
F4[ 0 ][ 2 ] = 1, F4[ 1 ][ 2 ] = 2, F4[ 2 ][ 2 ] = 1 (8-166)

– Otherwise, the following applies:

F1[ 0 ] = 2, F1[ 1 ] = 0 (8-167)
F3[ 1 ][ 1 ] = 8 (8-168)
F4[ 0 ][ 1 ] = 2, F4[ 1 ][ 1 ] = 4, F4[ 2 ][ 1 ] = 2, (8-169)

However, F1[ 2 ] is nowhere used in the current spec, and there is also a typo for F3[ 2 ][ 1 ].
The issue could be fixed by:

– 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 (8-160)
F2[ 0 ] = 1, F2[ 1 ] = 2, F2[ 2 ] = 1 (8-161)
F3[ i ][ j ] = F4[ i ][ j ] = 0, with i = 0..2, j = 0..2 (8-162)

– If both SubWidthC and SubHeightC are equal to 2, the following applies:

F1[ 0 ] = 1, F1[ 1 ] = 1 (8-163)
F3[ 0 ][ 1 ] = 1, F3[ 1 ][ 1 ] = 4, F3[ 2 ][ 1 ] = 1, F3[ 1 ][ 0 ] = 1, F3[ 1 ][ 2 ] = 1 (8-164)
F4[ 0 ][ 1 ] = 1, F4[ 1 ][ 1 ] = 2, F4[ 2 ][ 1 ] = 1 (8-165)
F4[ 0 ][ 2 ] = 1, F4[ 1 ][ 2 ] = 2, F4[ 2 ][ 2 ] = 1 (8-166)

– Otherwise, the following applies:

F1[ 0 ] = 2, F1[ 1 ] = 0 (8-167)
F3[ 1 ][ 1 ] = 8 (8-168)
F4[ 0 ][ 1 ] = 2, F4[ 1 ][ 1 ] = 4, F4[ 2 ][ 1 ] = 2, (8-169)

[bbross]

Thanks for reporting.

This will be fixed JVET-P2001-vC.