A method of encoding video characterized by comprising: writing a plurality of predetermined buffer descriptions into a sequence parameter set of a coded video bitstream; writing into a picture parameter set a flag to indicate whether or not a selected buffer description is modified; writing a plurality of updating parameters into a slice header of said coded video bitstream; and encoding a slice into said coded video bitstream using said slice header; wherein when said flag indicates that a selected buffer description is modified, said updating parameters comprise: a buffer description identifier for selecting a buffer description; a buffer element identifier for selecting a buffer element within said selected buffer description, wherein a buffer element corresponds to a unique reference picture; and a picture identifier for reassigning a unique reference picture to be associated with said selected buffer element within said selected buffer description; and a slice is encoded into said coded video bitstream using said modified buffer description; and wherein, when said flag indicates that a selected buffer description is not modified, said updating parameter selects one buffer description out of said plurality of buffer descriptions but does not modify said selected buffer description, and a slice is encoded into said coded video bitstream using said slice header and said selected buffer description. writing a plurality of predetermined buffer descriptions into a sequence parameter set of a coded video bitstream; writing into a picture parameter set a flag to indicate whether or not a selected buffer description is modified; writing a plurality of updating parameters into a slice header of said coded video bitstream; and encoding a slice into said coded video bitstream using said slice header; wherein when said flag indicates that a selected buffer description is modified, said updating parameters comprise: a buffer description identifier for selecting a buffer description; a buffer element identifier for selecting a buffer element within said selected buffer description, wherein a buffer element corresponds to a unique reference picture; and a picture identifier for reassigning a unique reference picture to be associated with said selected buffer element within said selected buffer description; and a slice is encoded into said coded video bitstream using said modified buffer description; and wherein, when said flag indicates that a selected buffer description is not modified, said updating parameter selects one buffer description out of said plurality of buffer descriptions but does not modify said selected buffer description, and a slice is encoded into said coded video bitstream using said slice header and said selected buffer description. a buffer description identifier for selecting a buffer description; a buffer element identifier for selecting a buffer element within said selected buffer description, wherein a buffer element corresponds to a unique reference picture; and a picture identifier for reassigning a unique reference picture to be associated with said selected buffer element within said selected buffer description; and a slice is encoded into said coded video bitstream using said modified buffer description; and wherein, when said flag indicates that a selected buffer description is not modified, said updating parameter selects one buffer description out of said plurality of buffer descriptions but does not modify said selected buffer description, and a slice is encoded into said coded video bitstream using said slice header and said selected buffer description.