The invention claims a sequence layer flag used for sub picture layer decoded image buffer parameter such as video coder or video decoder equal video coding device may by arranged to decode sequence level flag to determine the exist for one or more of a sub picture layer decoding unit DU and the access unit AU through coding image buffer CPB parameter on image time series and the DU with relevant supplemental enhancement information is SEI information or sub image SEI time series information. The coding device also can base on the sequence level flag from the time series image SEI information or the sub picture SEI time series information decoding the one or more sub picture level of CPB parameter.

A video coding device such as a video encoder or a video decoder may be configured to decode a sequence level flag to determine the presence of one or more sub-picture level coded picture buffer (CPB) parameters for a decoding unit (DU) of an access unit (AU) in either in a picture timing supplemental enhancement information (SEI) message or a sub-picture timing SEI message associated with the DU. The coding device may also decode the one or more sub-picture level CPB parameters from the picture timing SEI message or the sub-picture timing SEI message based on the sequence level flag.