JVET-AE0063 [AHG9] On operations for multiple NNPFs [L. Chen, O. Chubach, Y.-W. Huang, S. Lei (MediaTek)]

This was discussed in JVET on Friday July 14.

This contribution proposes an SEI message indicating multiple NNPFs as a group/list and related operations for a picture in response to the four questions on item 1)c in JVET-AD0362. The related operations for the indicated multiple NNPFs consist of four types of cascade, alternate, coherence and optional.

(coherence=parallel)

Conceptually this is similar to JVET-AE0052. Parallel is not explicitly in JVET-AE0052. Another aspect is that the encoder can take provision that only a single filter is activated at one time. No specific group activation SEI is needed in JVET-AE0063

Parallel operation might, for example, be useful to generate attention mechanism input for a subsequent network. This is something that would not appear in other SEI messages.

Use cases for parallel operation need more study, including the question how many could be operated in parallel.

Further study required if it is possible to bring those aspects into the SEI processing order SEI message (in VVC), or if this is so specific to NNPF that it would be a burden for implementers who only want to use SEI processing order for simpler cases of SEI messages.

It was agreed to produce an output document “Technology under consideration for future extensions of VSEI”. Proponents of JVET-AE0052 and JVET-AE0063 should combine the aspects from both contributions, and propose a text part.

It was also commented that a software implementation demonstrating different options would be desirable.