Application tracks in audio/video containers

Techniques for providing application tracks in a media data container are described. An application descriptor may be extracted from a coded bitstream. The coded bitstream comprises media data to be played by a media presentation system. The application descriptor identifies an application archive (i) that is retrievable by the media presentation system from one or more sources and (ii) that is required by the media presentation system at a set media time associated with the media data. While playing the media data, the media presentation system causes retrieving all of the application archive from the one or more sources before the set media time.