A method for decoding High Efficiency Video Coding, HEVC, video data, the method comprising: decoding, from a bitstream, a first video coding layer, VCL, network abstraction layer, NAL, unit in decoding order in an access unit, wherein the access unit includes the video data for reconstructing at least one picture; decoding, from the bitstream, a last VCL NAL unit in decoding order in the access unit; decoding, from the bitstream, a supplemental enhancement information, SEI, message of a particular type in the access unit prior to decoding the first VCL NAL unit, wherein the SEI message of the particular type defines a characteristic of the video data; and decoding, from the bitstream, a copy of the SEI message of the particular type in the access unit after decoding the first VCL NAL unit and prior to decoding the last VCL NAL unit, wherein content of the copy of the SEI message of the particular type in the bitstream is restricted to be identical to content of the decoded SEI message of the particular type, wherein the SEI message comprises one of: a pan-scan rectangle SEI message; a recovery point SEI message; a scene information SEI message; a full-frame snapshot SEI message; a progressive refinement segment start SEI message; a progressive refinement segment end SEI message; a film grain characteristics SEI message; a post-filter hint SEI message; a tone mapping information SEI message; a frame packing arrangement SEI message; a display orientation SEI message; or an active parameter sets SEI message. decoding, from a bitstream, a first video coding layer, VCL, network abstraction layer, NAL, unit in decoding order in an access unit, wherein the access unit includes the video data for reconstructing at least one picture; decoding, from the bitstream, a last VCL NAL unit in decoding order in the access unit; decoding, from the bitstream, a supplemental enhancement information, SEI, message of a particular type in the access unit prior to decoding the first VCL NAL unit, wherein the SEI message of the particular type defines a characteristic of the video data; and decoding, from the bitstream, a copy of the SEI message of the particular type in the access unit after decoding the first VCL NAL unit and prior to decoding the last VCL NAL unit, wherein content of the copy of the SEI message of the particular type in the bitstream is restricted to be identical to content of the decoded SEI message of the particular type, wherein the SEI message comprises one of: a pan-scan rectangle SEI message; a recovery point SEI message; a scene information SEI message; a full-frame snapshot SEI message; a progressive refinement segment start SEI message; a progressive refinement segment end SEI message; a film grain characteristics SEI message; a post-filter hint SEI message; a tone mapping information SEI message; a frame packing arrangement SEI message; a display orientation SEI message; or an active parameter sets SEI message. a pan-scan rectangle SEI message; a recovery point SEI message; a scene information SEI message; a full-frame snapshot SEI message; a progressive refinement segment start SEI message; a progressive refinement segment end SEI message; a film grain characteristics SEI message; a post-filter hint SEI message; a tone mapping information SEI message; a frame packing arrangement SEI message; a display orientation SEI message; or an active parameter sets SEI message.