A method of decoding implemented by a video decoder is provided. The method includes receiving a bitstream including a coded video sequence start (CVSS) access unit (AU), wherein the CVSS AU contains a picture unit (PU) for each layer, and wherein a coded picture in each PU is a coded layer video sequence start (CLVSS) picture; identifying the coded picture from one of the layers based on a picture order count (POC) value; and decoding the coded picture to obtain a decoded picture.