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VANC- Vertical Ancillary data.

VBR – Variable Bit Rate. An economical way to compress and encode video source material based on the algorithms’ ability to detect changes in the amount of data most appropriate for a particular scene. For video, this saves space by using fewer bits for simple content, and more for complex material that contains lots of changing detail or motion. A method for compressing audio which does not always use the same number of bits to record the same duration of sound.

VC-1 – a video compression format originally developed by microsoft for the now defunct HD DVD standard, which was dropped in favor of Blu-Ray. VC-1 is one of the three mandated formats for use on Blu-Ray. It is an efficient codec, which can deliver very high quality.

VCA – Voltage-Controlled Amplifier. a device that responds to a change in voltage at its control input by altering the gain of a signal being passed through it. also, the digital equivalent of a VCA.

VCF – Voltage-Controlled Filter. A filter whose cutoff frequency can be changed by altering the amount of voltage being sent to its control input; modifies its cutoff frequency by shifting how much voltage is transmitted. Also, the digital equivalent of a VCF.

VCO – Voltage Controlled Oscillator. 1. An oscillating circuit controlled by an alternating analog voltage. This creates the sound in the synthesizer using basic waveform shapes like sine, sawtooth, square, triangle and PWM. Tuning can be unstable, synths can overheat and are often very heavy. 2. Oscillator that alters its frequency by how much voltage is transmitted to its control input. 3. Frequency modulation is a form of analog angle modulation in which the baseband information-carrying signal, typically called the message or information signal m(t), varies the frequency of a carrier wave.  Audio signals transmitted by FM radio communications are the most common. However, FM radio can also transmit digital data with the low bandwidth digital information known as Radio Data System (RDS)in Europe and Radio Broadcast Data System (RBDS) in the U.S. The simplest approach to generating FM signals is to apply the message signal directly to a voltage-controlled oscillator (VCO).

VHF – Very High Frequency. Radio frequencies from 30 to 300 megahertz.

VHS – a half inch videocassette format developed in 1976 by Matsushita and licensed by JVC, using the “m” wrap tape path. Not compatible with the Beta format. See Super-VHS.

VHS-C – VHS Compact. Scaled-down version of vhs using miniature cassettes compatible with full-size VHS equipment through use of adapter. See Super-VHS.

VIR – Vertical Interval Reference. Reference signal inserted into the vertical interval of source video. This signal is used further down the video chain to verify parameters and to automatically adjust gains and phase.

v.i.t.c. – also VITC, Vertical Interval Time Code, pronounced “vitsee”. This type of time code is recorded in the vertical blanking interval above the active picture area. A time code recorded on videotape in two horizontal lines during each vertical blanking period of a video signal. Unlike LTC, VITC is recorded in the same tracks as the video information, so they can be read even while the tape is not moving, in the “still mode”. It is a popular method for recording for recording timecode. a timecode-address for reach frame of video is inserted in the vertical interval of the video signal where it is invisible on-screen yet easy to retrieve. Professional videotape machines can read vitc in either the play or the jog (manual) mode, making it ideal for editing. See also time code, LTC.

VOB – Video Object File. The primary video container on DVDs and SVCDs. Can contain audio, video, subtitles, etc. all MUXed in.

voc – a file extension specifying the creative labs sound blaster audio format. Typically encountered as filename.voc.

VR – Vibration Reduction, a technology found in some lenses and cameras used to reduce blur and produce sharp images at slower shutter speeds. VR is also found in binoculars to reduce hand-held image shakiness.

VRML – Virtual Reality Modeling Language. Used to create navigable 3-D environments on InterNet. A VRML plug-in must be downloaded for a web browser to view VRML files.

VTR – Video Tape Recorder.

VU – Volume Units. a unit of measure for complex audio signals, usually in decibels (dB). The reference level of -20 dB is 0 VU.

v/oct – 1 volt per octave. A form of control voltage (cv) typically used in Roland, Arp, Oberheim, Sequential and Moog synthesizers.

v-trig – voltage trigger. Positive (+) gate trigger used in Roland, Arp, Oberheim and Sequential synthesizers.

variable contrast paper – photographic paper of differing grades of contrast when exposed through special contrast filters.

variable focus lens – a zoom lens, one in which focal length is variable. Elements inside a variable focus lens shift their positions, enabling the lens to change its focal length, in effect, providing one lens that has many focal lengths.

variable media glossary – this glossary does not pretend to provide an exhaustive overview of the jargon used in new media preservation, but simply an explanation for the technical terms used in this publication. All of the terms apply most directly to at least one of the following categories – 1. variable media behavior, one of several medium-independent traits an artwork can possess.  2. variable media strategy- one of several philosophical approaches to solving a particular preservation issue.  3. hardware,  pertaining primarily to physical material or equipment.  4. software, pertaining primarily to computer programs or electronic signals.  5. format, pertaining primarily to a standard for storing electronic signals or data in a physical medium.

vectorscope- 1. a specialized oscilloscope designed to display the saturation and hue of chroma signals in a polar pattern, which demodulates the video signal and presents a display of r-y versus b-y. It allows for the accurate evaluation of the chrominance portion of a signal, plotting qualities in a compass-like graphic display. This device is essential in the evaluation of color signals when aligning color picture sources or matching and timing color sources in a television system. 2. A trademarked name that has become the generic description for a vector display unit which allows visual checking of the phase and amplitude of the color components of a video signal.

velocity- a type of midi data (range 1 to 127) that transmits or responds to the initial key attack, usually used to indicate how quickly a key was pushed down (attack velocity) or allowed to rise (release velocity), typically used to control the volume for a sound. A “note-on” message with a velocity value of 0 is equivalent to a “note-off” message.

velocity curve- a map that translates incoming velocity values into other velocities in order to alter the feel or response of a keyboard or tone module.

velocity sensitivity- a type of touch sensitivity in which the keyboard measures how fast each key is descending. Compare with pressure sensitivity.

versioning- also known as “version control” and “revision control”. The management of different versions of a set of data. In digital video it can stand for a comparison of multiple revisions of an image or clip sequence.

vertex shader – a real-time shader application. Graphics processing function used to add special effects to objects in a 3D environment by performing mathematical operations on the objects’ vertex data. Vertex shaders are applied for each vertex and run on a programmable vertex processor.

vertical blanking – the action of turning off the trace on an analog crt during vertical retrace.

vertical interval- 1. the vertical interval signals the picture monitor to go back to the top of the screen to begin another vertical scan. It is the portion of the video signal that occurs between the end of one field and the beginning of the next. During this time, the electron beams in the cameras and monitors are turned off (invisible) so that they can return from the bottom of the screen to the top to begin another scan. 2. indicates the vertical blanking period between each video field. Contains additional scan lines above the active picture area into which non-picture information (captioning, copy protection and other control signals) may be embedded.

vertical sync – the synchronizing pulses used to define the end of one television field and the start of the next occurring at a rate of approximately 59.94hz (color), and 60hz (black & white).

vertical sync pulse – the synchronizing pulse at the end of each field which signals the start of vertical retrace. See flyback.

vertigo effect – a camera technique created by Alfred Hitchcock during his film Vertigo that involves tracking backwards while simultaneously zooming in, making the person or object in the center of the image seem stationary while their surroundings change.

vibration reduction – often referred to as VR, an image stabilization feature in Nikon lenses that minimizes the effect of camera shake at slow shutter speeds, helping to prevent image blur.

vibrato- an effect created by small and fast changes in sound, a periodic change in frequency, often controlled by an LFO, with a period of less than 20hz. The sound ocillates between a high not and a low note. Compare with tremolo.

video – 1. in the context of podcasting, a video is a digital movie. This is a bit confusing because real video is not digital at all but analogue carried on a tape (video tape). For some reason we started to adopt the word ‘video’ from the moment is became possible to play moving images on a computer in the 90s. 2. An electrical signal that carries television picture information.

Video Assist – motion picture cameras often include a video camera that allows instant review of a scene to monitor framing, focus, and performance. Both this system and the person operating it are referred to as Video Assist.

Video Cassette Recorder – VCR. A common household appliance for recording and/or playing prerecorded video tapes. See VHS, NTSC and PAL.

video clip – in a non-linear editing environment, a clip indicates data of either video or audio that has been clipped out (copied) from a larger environment such as a reel or a video tape. in essence a video clip is a snippet of video. video clips usually are folders/directories that contain a great number of individual images files (the frames) which combined form the video sequence. the image files can be stored in a wide variety of picture file formats (e.g. bmp or TIFF). however, video clips can also be stored in a single file in a container file format such as quicktime or windows media.

video crosspoint module – in video switchers, a circuit board containing video switching crosspoints.

video dailies- synched videotapes with burn-in used for editing and confirming a day’s shoot.

video format- determines the way video is transmitted or received. For example, for a record it determines how to receive a video signal at the inputs. Most notably the setting of a video format must detail the video raster (scanning pattern).

video gain – also white level, white bar, reference white. The range of light-to-dark values of the image which are proportional to the voltage difference between the black and white voltage levels of the video signal. Expressed on the waveform monitor by the voltage level of the whitest whites in the active picture signal. Video gain is related to the contrast of the video image. The amount of amplification for video signals, expressed in decibels (dB).

video home system – VHS. Video Home System is a popular format for VCR systems worldwide, devleoped by the Japan Victor Company (JVC) in the 1970s. It used helical scan, FM encoding on magnetic tape. See also DVD.

video mixer – european term for video production switcher.

video monitor – a high-quality television set (without RF circuits) that accepts video baseband inputs directly from a TV camera, videotape recorder, etc.

video path – the electronic path within the device that routes and processes the video signals. Video path length refers to the amount of time required for a signal to travel from input to output.

video processing amplifier – a device that stabilizes the composite video signal, regenerates the synchronizing signals, and allows other adjustments to the video signal parameters.

video prompter – a mechanical device that projects and advances text on a mirror directly in front of a camera lens, allowing talent to read lines while appearing to maintain eye contact with viewers.

video signal – an electrical signal that includes all of the information present in the television picture together with the necessary synchronizing signals.

video switcher – also production switcher, video mixer. Device that accepts inputs from a variety of video sources and allows the operator to select a particular source to be sent to the switcher’s outputs. May also include circuits for video mixing, wiping, keying, and other special effects; may contain special effects generators.

video to audio crosstalk – a measurement, typically in dB, of the amount of unwanted video signal energy present in an audio signal.

video toaster – software & hardware developed by Newtek for the Amiga computer. Made special effects affordable for the low budget producer. Note: The Amiga was a personal computer sold by Commodore in the 1980s and 1990s, based on the 68000 family of microprocessors – see also Apple MacIntosh.

videocassette – a container holding both the feed and take-up reels which is inserted into a videotape recorder and threaded automatically.

videocassette recorder – multifunction machine intended primarily for recording and playback of videotape stored in cassettes.

videocasting – a video cast is similar to a podcast but this indicates that it is video exclusively while a podcast is usually audio.

videographer – 1. a person who works in the video medium, recording moving images and sound onto linear analog or digital tape, non-linear digital disc, or any other digital recording media, such as memory cards. On a set, he or she may be responsible for the lighting as well as the audio and images captured by the video camera or camcorder. Videographers differ from cinematographers because they record using video cameras or camcorders while cinematographers use film cameras to shoot film footage onto motion picture film stock. The development of high definition digital cinematography, however, is quickly blurring this distinction.  2. a video photographer who specializes in social events.

videotape recorder – also video tape recorder, VTR. A device which permits audio and video signals to be recorded on magnetic tape.

view camera – a large format camera. Cameras that produce an individual image size of 5″ x 4″ or larger. It is most often found in a studio, and is sometimes called a “studio camera”, although the view camera can be transported and set up in the field. The view camera is the largest of the basic camera types.

viewfinder – 1. a video monitor attached directly to a video camera. 2. a viewing device on a camera used by the photographer to see the field of view taken in by the camera’s lens and the portion of the view that will be recorded on the image sensor or on film. Also known as a finder or projected frame. It may be a simple window that displays the actual image or an electronic view frame.

viewfinder camera – camera with a viewfinder that is separate from the lens used in taking the picture. A simple point-and-shoot disposable camera is an example of a viewfinder camera, but not all viewfinder cameras are simple. the viewfinder camera is the most popular type of camera.

viewfinder screen – the ground glass surface of some viewfinder cameras, such as a large-format field camera, on which the photographer views and composes the scene about to be photographed.

viewing angle – –  the viewing angle determines how far off the axis (screen centerline) a viewer can still sit and still see a quality image. This is no greater than 45 degrees off the projection axis.

viewing cone – –  the best viewing area for the audience. the term cone is used because there is width, height, and depth to the best viewing area, and this area emanates from the center of the screen.

viewpoint – location of the camera relative to the subject.

vignette mask – a special effects mask in front of the camera’s lens that blocks the light around the scene’s margins, producing a vignetted picture.

vignetting – 1. when unintentional, it is underexposure at the image’s edges or corners caused by an unsuitable lens hood, filter or other attachment that partially blocks the field of view.  2. when intentional, it is an image printing technique where the central area is fully printed but its edges gradually fade. Vignetting can also be achieved when taking the picture by placing a vignette mask in front of the lens.

vignette – visual special effect whereby viewers see images through a perceived keyhole, heart shape, diamond, or whatever. In low-budget form, achieved by aiming camera through cutout of desired vignette.

vignetting – 1. undesirable darkening at the corners of a picture, as if viewer’s peering through a telescope, due to improper matching of lens to camera; pickup’s scope exceeds lens size. 2. The partial masking, or blocking or peripheral light rays either by intent, or by accident. In theatrical projection, the blockage of peripheral light rays in a projection lens due to a lens barrel that is too long, or to a lamphouse optical system that is not correctly matched to the limiting aperture of the projection lens.

vinegar syndrome – film or magnetic media. A deterioration process that affects acetate film base, characteristic of the breakdown of the acetate tape binding or backing layer. Vinegar syndrome is identifiable by the vinegar smell that becomes evident as the acetate base breaks down and acetic acid gas is released. Films with vinegar syndrome will deteriorate physically, shrinking and losing flexibility; the tape may become brittle and difficult to handle. In final stages, films with vinegar syndrome can become fused and resemble a hockey puck.

virtual- existing only in software.

vision mixer – european term for video production switcher.

visual density – spectral sensitivity of the receptor which approximates that of the human eye.

visual effects – alterations to a film’s images during post-production. Contrast with special effects (except in UK television, where visual effects and special effects are sometimes the same).

Visual Effects Rigger – the person that prepares the miniature models, creature puppets, or whatever the camera subject is, to perform whatever the object is supposed to do during the shot.

Visual Effects Supervisor – also Visual Effects Director. The chief of a production’s visual effects crew.

VOCODER – Voice Operated enCODER. A type of effect typically used with vocals for its unique sound. Vocoding splits audio signals into multiple frequency bands, analyzes them, and applies the frequency and envelope characteristics of one sound (the modulator, usually a vocal) onto the other sound (the carrier, usually a synth pad or drum loop), making your instruments appear to speak.

voice- 1. an element of synthesizer circuitry capable of producing a note. The polyphonic capability of a synthesizer is defined by how many voices it has. 2. In yamaha synthesizers, a patch (sound). 3. Refers to a specific musical line for voice or instrument. See polyphony.

voice channel – a signal path consisting of at least one oscillator and a VCA or digital equivalent, that can create notes. On a typical synthesizer, two or more voice channels, each with its own waveform and parameter settings, can be combined to form a single note.

voice-over – also voice over, VO. Indicates that dialogue or narration will be heard on a movie’s soundtrack, above background sound or music, but the speaker will not be shown. The abbreviation is often used as an annotation in a script. Typically applied to edited visual during post-production.

voice-over artist – the unseen person who does the speaking necessary to create a voice-over.

voice stealing – when a synthesizer is programmed to play more sounds than the available voices, it shuts down some present voices so new tunes can be played, typically those that have been sounding longest or are at the lowest amplitude.

volt – the standard unit for measuring the difference of potential between two points in an electronic circuit. Also for measuring electromotive force; symbolized by an upper case V.

voltage – the electrical potential to create current flow in a circuit.

voltage regulator – a circuit used for controlling and maintaining a voltage at a constant level.

volume- an identifiable unit of data storage in computers or storage systems. it might be physically removable. In tape storage systems, a volume may be a tape cartridge (or in older systems, a tape reel). in mainframe storage systems, a volume may be a removable hard disk. each volume can be specified by the user via its system-unique name or number. In some systems, the physical unit may be divided into several separately identifiable volumes.

volumetric fog – in rendering, the simulation of light shining through fine particles (fog, smoke, or dust) in the air. Also known as light fog.

voxel – volume element. a cubic unit of 3D volume defined at a size appropriate to the required resolution, sometimes described as the 3D equivalent of a pixel.

vu meter – volume-unit meter, a type of meter used to indicate average audio amplitude.