VBI
Vertical blanking interval. The scan lines in a television signal that do not contain picture information. These lines are present to allow the electron scanning beam to return to the top and are used to contain auxiliary information such as closed captions.

VBR
Variable bit rate. Data that can be read and processed at a volume that varies over time. A data compression technique that produces a data stream between a fixed minimum and maximum rate. A constant level of compression is generally maintained, with the required bandwidth increasing or decreasing depending on the complexity (the amount of spatial and temporal energy) of the data being encoded. In other words, data rate is held constant while quality is allowed to vary. Compare to CBR.

VBScript
A proprietary Visual Basic-based programming language defined by Microsoft for use in their Internet Explorer Web browser. (See also, JavaScript and JScript, above.)

VBV
Video buffering verifier. A hypothetical decoder that is conceptually connected to the output of an MPEG video encoder. Provides a constraint on the variability of the data rate that an encoder can produce.

VCAP (Video Capable Audio Player)
An audio player which can read the limited subset of video features defined for the DVD-Audio format. (Contrast with universal DVD player.)

VCD
Video Compact Disc. Near-VHS-quality MPEG-1 video on CD. Used primarily in Asia.

VfW
See Video for Windows.

VGA (Video Graphics Array)
A standard analog monitor interface for computers. Also a video graphics resolution of 640x480 pixels.

VHS
Video Home System. The most popular system of videotape for home use. Developed by JCV.

Video CD
An extension of CD based on MPEG-1 video and audio. Allows playback of near-VHS-quality video on a Video CD player, CD-i player, or computer with MPEG decoding capability.

Video for Windows
The system software additions used for motion video playback in Microsoft Windows. Replaced in newer versions of Windows by DirectShow (formerly called ActiveMovie).

Video Manager (VMG)
In DVD-Video, the information and data to control one or more Video Title Sets (VTS) and Video Manager Menu (VMGM). It is composed of the Video Manager Information (VMGI), the Video Object Set for Video Manager Menu (VMGM_VOBS), and a backup of the VMGI (VMGI_BUP).

Video Title Set (VTS)
In DVD-Video, a collection of Titles and Video Title Set Menu (VTSM) to control 1 to 99 Titles. It is composed of the Video Title Set Information (VTSI), the Video Object Set for the Menu (VTSM_VOBS), the Video Object Set for the Title (VTST_VOBS), and a backup of the VTSI (VTSI_BUP).

VIDEO_TS
UDF file name used for video directory on disc volume. Files under this directory name contain pointers to the sectors on the disc which hold the program streams.

videophile
Someone with an avid interest in watching videos or in making video recordings. Videophiles are often very particular about audio quality, picture quality, and aspect ratio to the point of snobbishness.

VLC (Variable Length Coding)
See Huffman coding.

VMGI (Video Manager Information)
Information required to manage one or more Video Title Sets and Video Manager Menu areas. This is non real time data located at the start of the Video Manager area.

VOB (Video Object)
A single, complete file composed of multiplexed Video, Audio, Sub-picture, PCI and DSI elementary streams, and consisting of an integer number of VOBUs.

VOBS (Video Object Set)
A collection of one or more VOBs. There are three types: 1) VMGM_VOBS for the Video Manager Menu (VMGM) area, 2) VTSM_VOBS for the Video Titles Set Menu (VTSM) area, and 3) VTST_VOBS for the Video Title Set Title (VTST) area.

VOBU (Video Object Unit)
A small (between 0.4 and 1.0 seconds) physical unit of DVD-Video data storage, usually the length of one GOP, that begins with a Navigation pack (NV_PCK) and usually includes an integer number of GOPs.

Volume Management Information
Identifies disc side and content type.

Volume Space
Collection of sectors that make the volume. Not all sectors on the disc comprise the volume. Some near the inner and out spiral are used as leader.

volume
A logical unit representing all the data on one side of a disc.

VSDA
Video Software Dealers Association.

VTSI (Video Title Set Information)
Information required to manage one or more Titles and Video Title Set Menus. This is non real time data located at the start of the Video Title Set.