Handling of coded video in sub-bitstream extraction process

An apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:

• perform a conversion between a video comprising one or more video pictures in a video layer and a bitstream of the video according to a rule,
• wherein the rule specifies that, in a process of subpicture sub-bitstream extraction to output a sub-bitstream, removal of (i) a video coding layer (VCL) network abstraction layer (NAL) unit, (ii) filler data NAL units associated with the VCL NAL unit, and (iii) filler payload supplemental enhancement information (SEI) messages associated with the VCL NAL unit is performed regardless of an availability of an external means used to replace a parameter set that is removed during the subpicture sub-bitstream extraction.

A non-transitory computer-readable storage medium storing instructions that cause a processor to:

• perform a conversion between a video comprising one or more video pictures in a video layer and a bitstream of the video according to a rule,
• wherein the rule specifies that, in a process of subpicture sub-bitstream extraction to output a sub-bitstream, removal of (i) a video coding layer (VCL) network abstraction layer (NAL) unit, (ii) filler data NAL units associated with the VCL NAL unit, and (iii) filler payload supplemental enhancement information (SEI) messages associated with the VCL NAL unit is performed regardless of an availability of an external means used to replace a parameter set that is removed during the subpicture sub-bitstream extraction.