A method of processing SHVC multi-layer video data, the method comprising: generating a file that comprises a media data box for each track of media data and a movie box, each media data box containing samples of the respective track, each of the samples being a video access unit of the multi-layer video data, and the movie box including a track box for each track of the media data, wherein each track box includes a media box that contains metadata for the samples of the track of media data, wherein: generating the file comprises generating, in the file, a sub-sample information box in a sample table box of a media information box of the media box, where the sub-sample information box contains flags that specify a type of sub-sample information given in the sub-sample information box, and wherein the value of the flags specify the type of sub-sample information as follows: 0 NAL-unit-based sub-samples containing one or more contiguous NAL units; 1 decoding-unit-based sub-samples containing exactly one decoding unit; 2 tile-based sub-samples containing either one tile and any associated non-VCL NAL units, or one or more non-VCL NAL units; 3 CTU-row-based sub-samples containing one CTU row within a slice and any associated non-VCL NAL units of the VCL NAL unit(s) containing the CTU row or one or more non-VCL NAL units; 4 Slice-based sub-samples containing one slice and any associated non-VCL NAL units, or one or more non-VCL NAL units; and 5 Picture-based sub-samples containing exactly one coded picture and zero or more non-Video Coding Layer Network Abstraction Layer units associated with the coded picture. generating the file comprises generating, in the file, a sub-sample information box in a sample table box of a media information box of the media box, where the sub-sample information box contains flags that specify a type of sub-sample information given in the sub-sample information box, and wherein the value of the flags specify the type of sub-sample information as follows: 0 NAL-unit-based sub-samples containing one or more contiguous NAL units; 1 decoding-unit-based sub-samples containing exactly one decoding unit; 2 tile-based sub-samples containing either one tile and any associated non-VCL NAL units, or one or more non-VCL NAL units; 3 CTU-row-based sub-samples containing one CTU row within a slice and any associated non-VCL NAL units of the VCL NAL unit(s) containing the CTU row or one or more non-VCL NAL units; 4 Slice-based sub-samples containing one slice and any associated non-VCL NAL units, or one or more non-VCL NAL units; and 5 Picture-based sub-samples containing exactly one coded picture and zero or more non-Video Coding Layer Network Abstraction Layer units associated with the coded picture. 0 NAL-unit-based sub-samples containing one or more contiguous NAL units; 1 decoding-unit-based sub-samples containing exactly one decoding unit; 2 tile-based sub-samples containing either one tile and any associated non-VCL NAL units, or one or more non-VCL NAL units; 3 CTU-row-based sub-samples containing one CTU row within a slice and any associated non-VCL NAL units of the VCL NAL unit(s) containing the CTU row or one or more non-VCL NAL units; 4 Slice-based sub-samples containing one slice and any associated non-VCL NAL units, or one or more non-VCL NAL units; and 5 Picture-based sub-samples containing exactly one coded picture and zero or more non-Video Coding Layer Network Abstraction Layer units associated with the coded picture.