Multiple audio encodings are allowed including MPEG Audio, Dolby Digital (AC-3) and linear PCM. Directory and file structure VRO file format A DVD-VR recorded disc contains a 'DVD_RTAV' directory in the root of the filesystem, in which a single 'VR_MOVIE.VRO' file exists, containing the raw audio and video data for all video recordings on the disc. The recording metadata along with navigation data to represent playlist, programs, and so on are also stored in the 'VR_MANGR.IFO' file in the same directory. A backup copy of this file (VR_MANGR.BUP) typically is present as well to provide data redundancy. Unlike standard DVD-Video recordings, the aspect ratio (4:3 or 16:9) is contained in the file itself as part of the video stream. Thus DVD-VR supports mixed format presentations within a single file. Contrast DVD-Video where the aspect ratio is coded into the accompanying file and thus a single file can be in a single aspect ratio only. VRO is a container format for multiplexed audiovisual content. VRO file is an equivalent to a collection of DVD-Video VOB files. If one does not care about edits (e.g., deleting recorded videos), one can play the VRO directly as if it were a standard DVD-Video VOB file. Fragmented VRO files are not widely supported by software players and video editing software. File system The file system used on the media is UDF Revision 2.0. Packet writing technology is used to allow random access to, and incremental updating of the optical media. See also DVD+VR VR Mode VOB DVD formats Universal Disk Format DVD-RW, DVD-R, DVD-RAM, and DVD-R9 DVD-AR References External links DVD Format/Logo Licensing Corporation DVD Forum DVD