JVET-AP0095 AHG9: On the modality information SEI message extension [J. Xu, Y.-K. Wang (Bytedance)]

This document proposes the following items to the modality information SEI message extension:

1. Specify a constraint to disallow signalling multiple spectrum information when the associated picture is of the 4:0:0 colour format.
2. Add syntax elements specifying a separate colour description to describe the colour domain where multispectral pictures are generated.

For item 1, it was suggested to use an interface variable to determine the colour format.

Agreed to the constraint in item 1, with the interface variable.

For item 2, it isn’t clear that the proposed information is useful.

JVET-AP0095 AHG9: On the modality information SEI message extension