Patent attributes
Examples of video encoding methods and apparatus and video decoding methods and apparatus are described. An example method of video processing includes performing a conversion between a video including one or more layers and a bitstream of the video according to a rule, wherein the rule specifies, in a process of sub-bitstream extraction to output an output sub-bitstream, whether to generate non-scalable nested supplementary enhancement information (SEI) messages by extracting scalable-nested SEI messages from a scalable nesting SEI message based on a first flag indicating whether the SEI message applies to specific output layer sets (OLSs) and a second flag indicating whether the SEI message applies to all subpictures or only to specific subpictures.
