JVET-AK0188 AHG9: On NNPF filtering control strength value adjustment [J. Xu, Y.-K. Wang (Bytedance)]

In the current design of NNPF, filtering control strength values can be passed to the NNPF but cannot be adjusted. In this contribution, it is asserted that such a design has various limitations. A new syntax element is proposed to be added to the NNPFA SEI message so that adjustment of the filtering control strength values is enabled.

It was noted that NNPFA is signalled at most once per picture, so the proposed signalling of an adjustment would apply to an entire picture and not be adjusted per slice.

A -v3 bitstream would not include the proposed new syntax element, nnpfa_delta_strength_control_val.

A -v3 decoder would not make the signalled QP adjustment, but a -v4 decoder would make the adjustment.

The QpBdOffset variable is referred to in the proposed text, but is defined in VVC not in VSEI.

There were some questions regarding the usefulness of the proposal.

No action was taken on this.