JVET-AK0278 AHG9: Constituent Rectangles / Enhanced Colour Format Information SEI extension to support 4:2:2 source content coded in bitstream with 4:2:0 chroma format [S. Keating, M. Ikeda (Sony)] [late]

Consideration of this was chaired by S. Deshpande on 16 January 2025 at 18:00 PM

It is proposed to extend the Constituent Rectangles (CR) SEI message and/or the Enhanced Colour Format Information (ECFI) SEI message to support coding of 4:2:2 chroma format source content in a bitstream coded with 4:2:0 or monochrome chroma format.

It was asked if chroma location information is signalled.

It is agreed that currently it is not signalled in the proposal but needs to be signalled.

For ECFI change is not needed as it is already supported.

Also, for CR only the 2.1.1 unequal rectangle sizes need to be considered.

There currently exists a 4:4:4 flag in CR which would need some change. Some size requirement adjustment would be needed.

The idea was supported by the group for CR based on 2.1.1 section of the proposal.

Further discussion was needed to review the exact text, which needed to be developed.

See notes for JVET-AK0332.