A method of decoding an encoded video bitstream using at least one processor, including: obtaining from the encoded video bitstream a coded video sequence including a picture unit corresponding to a coded picture; obtaining a picture header (PH) network abstraction layer (NAL) unit included in the picture unit; obtaining at least one video coding layer (VCL) network abstraction layer (NAL) unit included in the picture unit; decoding the coded picture based on the PH NAL unit, the at least one VCL NAL unit, and an adaptation parameter set (APS) included in an APS NAL unit obtained from the coded video sequence; and outputting the decoded picture, wherein the APS NAL unit is available to the at least one processor before the at least one VCL NAL unit.