TheDVD-VR standard defines a logical format for video recording onDVD-R,DVD-RW, andDVD-RAM style media, including thedual layer versions of these media. As opposed to media recorded with theDVD+VR recording standard, the resulting media are notDVD-Video compliant, and do not play back in someDVD-Video players. Most DVD video recorders in the market that supportDVD-R,DVD-RW, orDVD-RAM media record to these media in DVD-VR mode, as well as in aDVD-Video compliant mode. It is possible to use the DVD-VR format with DVD+R and DVD+RW media, but no examples are known other than some PC based recording utilities.
The standard was introduced in 1999 by theDVD Forum, and licensing is managed by the DVD Format/Logo Licensing Corporation.[1] For each of the supported media, the full recording standard consists of three parts being: Physical Specifications (Part 1), File System Specifications (Part 2), and the Video Recording Specifications (Part 3).
The DVD-VR specification allows implementing the following main features:
DVD-VR recorded media are notDVD-Video compliant, and do not play back in allDVD players. Some more recent DVD players, and also theSonyPlayStation 2, can play discs recorded in the DVD-VR format.
The DVD-VR standard defines a logical format for recording and editing of video on aDVD disc. Instead of modifying theDVD-Video standard, a separate standard was created to allow for this.
Video is recorded as anMPEG program stream. Video resolution depends on the recording quality and thevideo format used. Multiple audio encodings are allowed including MPEG Audio,Dolby Digital (AC-3) andlinear PCM.
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 providedata redundancy.
Unlike standard DVD-Video recordings, the aspect ratio (4:3 or 16:9) is contained in the .VRO file itself as part of the video stream. Thus DVD-VR supports mixed format presentations within a single .VRO file. Contrast DVD-Video where the aspect ratio is coded into the accompanying .IFO file and thus a single .VOB file can be in a single aspect ratio only.
VRO is acontainer format for multiplexed audiovisual content.[2][3] 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.[4] Fragmented VRO files are not widely supported by software players and video editing software.[2]
Thefile system used on the media isUDF Revision 2.0.
Packet writing technology is used to allow random access to, and incremental updating of the optical media.