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 and a bitstream of the video according to a rule, wherein the bitstream includes network abstraction layer (NAL) units for multiple video layers according to a rule; wherein the rule defines that a sub-bitstream extraction process to generate an output bitstream comprising an output layer set (OLS) includes one or more operations that are selectively performed responsive to the following conditions: (1) a list of NAL unit header layer identifier values in the OLS does not includes all values of NAL unit header layer identifiers in all video coding layer (VCL) NAL units in the bitstream, and (2) the output bitstream containing a supplemental enhancement information (SEI) NAL unit that contains a scalable-nesting SEI message.
