A device for processing media data is configured to receive media data including virtual reality (VR) video data; determine, based at least in part on data signaled at an adaptation set level of a media presentation description for a media presentation, a projection mapping used in the media presentation; process segments of a video representation of the media presentation based on the projection mapping used in the media presentation. A device for processing media data is configured to generate media data that includes VR video data; include in the media data, data signaled at an adaptation set level of a media presentation description that identifies a projection mapping used in media presentation included in the media data; and send segments of a video representation of the media presentation based on the projection mapping used in the media presentation.