JVET-AO0096 AHG9: On interface text for SEI messages in TuC [J. Nam, H. Tan, J. Lee, C. Kim, J. Lim, S. Kim (LGE)]

This contribution proposes modification to some aspects in the interface text of VVC for SEI messages in TuC. The proposed modifications are as follows:

1. On updating interface text for DOI SEI

2. On updating interface text for CR SEI

3. On specifying interface text for BRI SEI

4. On specifying interface text for CMI SEI

For item 1, suggests to use doi_nuh_layer_id[ i ] as a variable index rather than i

It was suggested to also indicate what the value of i should be described in the interface. It is currently described in the SEI message.

It is also noted there is also an array index of j for some of the interface variables.

Some modification is seen to be necessary.

A key question is what should be done in the codec interface vs. in the SEI message itself. Should the interface provide information about all layers present in the bitstream or just those layers used by the SEI message? Where should index vs layer ID be used?

If information of all layers present in the bitstream is included in the interface, it would allow identical text for multiple SEI messages and simpler interface text.

It was suggested that the PRI SEI message includes information only for the layers used. This might be considered editorial and possible to change in an errata.

Offline activity was suggested.

Further discussion was requested.

This was further discussed 0000 on Thursday 22 Jan 2026.

All items in the -v2 version were agreed.

JVET-AO0096 AHG9: On interface text for SEI messages in TuC