As identified when working on https://github.com/AOMediaCodec/av1-hdr10plus/, the grouping_type_parameter field is 32 bits but for AV1 metadata, 8 bits are used for identifying the type of metadata. In the case of ITU-T T.35 metadata, this means the grouping_type_parameter field only has 24 bits for discriminating against various T.35 metadata. This is not sufficient. For example for HDR10+, at least 40 bits would be needed (country code (assuming no extension), terminal provider code and extension, possibly application code).
cconcolato
commented
3 years ago
As identified when working on https://github.com/AOMediaCodec/av1-hdr10plus/, the
grouping_type_parameterfield is 32 bits but for AV1 metadata, 8 bits are used for identifying the type of metadata. In the case of ITU-T T.35 metadata, this means thegrouping_type_parameterfield only has 24 bits for discriminating against various T.35 metadata. This is not sufficient. For example for HDR10+, at least 40 bits would be needed (country code (assuming no extension), terminal provider code and extension, possibly application code).