PROBLEM TO BE SOLVED: To provide a design technique for a parameter set in video coding.SOLUTION: A video coder performs the steps of: receiving, in a video parameter set, one or more syntax elements including information related to a hypothetical reference decoder (HRD) parameter; receiving, in video data, a first sequence parameter set including the first syntax element for identifying a video parameter set; receiving, in the video data, a second sequence parameter set including the second syntax element for identifying the video parameter set; and coding, on the basis of the one or more syntax elements, a first set of a video block related to a first parameter set and a second set of a video block related to a second parameter set.SELECTED DRAWING: Figure 12