A video file may include movie fragments divided into sub-track fragments that store all pictures of common hierarchical levels for the respective hierarchical levels. In one example, an apparatus includes an interface configured to output data according to a streaming protocol, and a control unit configured to assemble encoded video data into a plurality of sub-track fragments, each of the sub-track fragments comprising a plurality of hierarchically related video pictures of the encoded video data, wherein the plurality of hierarchically related video pictures each correspond to a common hierarchical layer receiving a request in accordance with the streaming protocol, wherein the request specifies at least one of the plurality of sub-track fragments, and, in response to the request, cause the interface to output the plurality of hierarchically related video pictures of the at least one of the plurality of sub-track fragments.