Type of syntax element slice_num_alf_aps_ids_luma

[ksuehring]

From the meeting notes:

Adopt APS types, and define APS types for ALF parameters and LMCS (reshaper) parameters, and signal the LMCS APS_ID in the tile group header when LMCS is enabled, from option 2 of JVET-N0805. Decision: Adopt (with a loop in the tile group header when multiple ALF APSs are used in the same tile, with the number of loop entries determined by a number minus 1 coded as ue(v))

The syntax element slice_num_alf_aps_ids_luma is coded as tb(v) in the draft, not ue(v) as decided with the adoption of JVET-N0805.

[ksuehring]

Note, this is primarily a specification issue, but also relevant to VTM implementation.

[nanhu]

tb(v) was used in the adopted JVET-N0415 implementation. So tb(v) was put in both draft and VTM-5.0.

[nanhu]

Regarding "minus 1", since we we can just use fixed filters which were also adopted in JVET-N0415 and don't use any APS, then slice_num_alf_aps_ids_luma will be 0. In this case, "minus 1" syntax doesn't fit the JVET-N0415 adoption.

[bbross]

Fixed in D6 vC