JVET-AP0165 AHG9: On temporal resampling information in EOI SEI message [J. Chen, Y. Ye (Alibaba)]

The EOI SEI message was extended in TuC by introducing temporal resampling information in last meeting. This contribution raised several issues in the current design of the temporal resampling information, and the following items are proposed to address them.

1. Aspect 1: either impose a constraint on the value of eoi_temporal_extrapolation_flag and eoi_temporal_exrapolation_dir_flag such that both flags remain constant within one CLVS, or revise the current semantics to clarify the suggested decoder behaviour when these two flags change value.
2. Aspect 2: signal eoi_temporal_clvs_flag only when eoi_temporal_extrapolation_flag is equal to 1, and infer eoi_temporal_clvs_flag to be equal to 1 when eoi_temporal_extrapolation_flag is equal to 0.
3. Aspect 3: Remove four constraints
4. Aspect 4: Allow the signalling of temporal resampling information when eoi_num_int_pics is equal to 0.

For aspect 1, it was suggested that the proposed constraint is already effectively imposed by other constraints.

It was noted that there is a current constraint that two pictures are required for extrapolation which may not be appropriate. JVET-A0173 is related.

It was suggested that the proposed constraint in aspect 2 seems overlay strict, and could either be made less strict or not imposed.

Aspects 1, 2 were discussed in JVET-AP0292. See notes there.

Agreed to aspect 3 remove the four constraints.

For aspect 4, refer to notes in JVET-AP0152.

JVET-AP0165 AHG9: AHG9: On temporal resampling information in EOI SEI message