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A B C D E F G H I J K L M N O P Q R S T U [V] W X Y Z

V

V.90
A standard for modems that send data at 33.6Kbits/s and receive it at 56Kbits/s. Combines earlier K56flex and x2 standards.
Variable Audio Output.
Low level audio output (usually in the form of a RCA connection) which varies in strength with the volume or level of the source component.
VCR (Video Cassette Recorder).
Audio/video playback device that accepts standard analog videocassette tapes (VHS, S-VHS, Hi-8), reads the data from them, and passes along the signals to the video display and audio system.
Vector Graphics.
Image stored as mathematical instructions, lines (vectors), points, and angles.
Two major advantages:
Small file size – vector objects can be described using very little data
Rescaling – any vector object can be resized without any loss of quality
Problems:
Lots of proprietary formats
Cannot achieve photorealism using vector graphics
Vector Line.
Imaginary line dividing the set (action area) in two; all camera angles must be taken from one side of this line to maintain unambiguous transitions from shot to shot.
Vectorscope.
Specialized oscilloscope that graphically displays the colour parts of a video signal, precisely showing the colours' strength and hue.
Vertical Blanking Interval.
Short span of time when the electron beam of a cathode ray tube is shut down after it has painted the last line of an image so the beam can be restarted at the top left corner to draw the next screen.
Vertical Interval Switching
Randomly switching from one video signal to another, will often result in a jump in the picture upon playback. The problem is compounded when the tape is copied. To avoid this problem, switching is best performed on synchronized signals during the vertical blanking retrace period, known also as the vertical interval. This allows complete replacement of one whole frame by a second whole frame resulting in a very smooth on-screen switch.
Vertical Resolution.
Number of horizontal lines that can be output by a video display.
VGA (Video Graphics Array).
1) 1987 standard for graphics cards in IBM compatible PCs, determining sweep frequencies, colours, resolution, and wire connections in monitor plugs.
2) A standard for displaying images at resolutions up to 640 x 480, in at least 16 colours.
VHF (Very High Frequency).
TV channels 2-13
VHS (Video Home System)
Half-inch magnetic videotape cartridge format developed for home use with the ability to record and playback analog video and audio signals.
VHS-C (VHS-Compact).
A miniature version of the VHS tape format utilizing smaller cassettes that may also be played on standard VHS machines by using an adapter cartridge.
VHS Hi-Fi.
An improved stereo audio recording/playback system found on some camcorders and VCRs. Because the audio tracks are mixed and recorded with the video signal, audio only dubbing of these tracks is not possible.
VIASS or VISS.
VHS Index-Address Search System. A way of bookmarking up to 8 places on a VHS or SVHS tape, making them easy for a VCR to "find" later.
Video Bandwidth.
The range between the lowest and highest signal frequency of a given video signal. In general, the higher the video bandwidth, the better the quality of the picture. Video bandwidths used in studio work typically vary between 3 and 12 MHz. Consumer VCRs are generally capable of 3-5.5 MHz.
Video Capture Card
Computer circuit capable of converting a video signal into a digital computer signal that can be stored on disk or manipulated.
Video Editing.
A procedure for combining selected portions of video footage in order to create a new, combined version. A variety of editing consoles are available. During video editing, special effects such as wipes, dissolves, inserts, etc. can be added. Professional editing is done using time code recorded on every frame of the magnetic tape allowing single frame accuracy. Audio editing is often carried out simultaneously with video editing.
Video Encoder.
A device that makes a composite colour video signal from component video signals.
Video Enhancer.
A general term used to describe a device used to correct video image problems.
Video Gain.
The nominal composite video signal level is 1 volt. At this level, a fully saturated image is transmitted and boosting the signal offers no advantage. Most video equipment is designed to output the same 1-volt level video signal. In cases where the signal level has been reduced, such as after a long cable run, an amplifier with video gain may be employed to restore the proper level.
Video Mixer.
A device used to combine video signals from two or more sources. Inputs are synchronized, then mixed along with various special effects patterns and shapes. A video mixer usually generates sync signals allowing genlocking of additional video sources to the first source.
Video Wall.
A large array of several monitors, placed close to one another in the shape of a video screen or "wall." Each monitor is fed only part of the original video image by using a video-wall generating unit. This device is a digitally-based processor which converts the original analog video signal to digital, rescans, resamples and generates several individual analog video outputs for driving each array monitor separately. When viewed from a distance, the effect can be very dramatic.
Video Output.
Connection point of a video or audio/video component that allows a video signal to move out to another component. Video/VGA projector Device designed to project images made from NTSC video or from a VGA computer output (640480 pixels scanned at 35,500 progressive sweeps per second).
Vignetting.
A condition where the picture's edges (usually the corners) show the dark edges of the lens, often because the lens format is too small for the pickup chip.
Virus
A malicious program written to adversely affect a computer's operation, without the user's knowledge.
VISCA (Sony Video System Control Architecture).
A two-way protocol from Sony that permits computers, through their RS-232 or RS-422 ports, to communicate with VCRs and other control-M or LANC enabled devices.
VITC (Vertical Interval Time Code).
A popular method for recording time code onto videotape. A time code address for each video frame is inserted in the vertical interval (the vertical blanking retrace period) of the video signal, where it is invisible on-screen yet easily retrieved, even when a helical scanning VCR is in pause mode. The most common form of VITC is SMPTE-VITC.
VRAM (Video random access memory).
Special type of memory used on video adaptors to speed up image display. Can be accessed simultaneously by two devices, so the digital-to-analogue converter (Randac) can provide screen updates while the video processor is supplying data.
Volume.
(Loudness is a perceived measurement in dbA or acoustic decibels while amplitude refers to the size or how high the sound wave is (peak to through) and volume refers to the amount of sound moved through vibration.

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