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Glossary O-T
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Off-Line Editor
A low resolution, usually computer and disk based edit system in which the creative editing decisions can be made at lower cost and often with greater flexibility than in an expensive fully equipped on-line suite. See also Non-Linear Editor
On-Line Editor
An editing system where the actual video master is created. An on-line bay usually consists of an editing computer, video switcher, audio mixer, 1 or more channels of DVE, character generator, and several video tape machines.
Oxide tape
Magnetic tape coated with microscopic particles of ferric oxide dispersed in a liquid binder.
PAL
Phase Alternate Line. The television and video standard in use in most of Europe, Hong Kond and the Middle East. Consists of 625 horizontal lines at a field rate of 50 fields per second. (Two fields equals one complete Frame). Only 576 of these lines are used for picture. The rest are used for sync or extra information such as VITC and Closed Captioning.
PALplus
A widescreen (16x9) television standard in use in Europe that is compatible with existing 4x3 TV sets. Non-16x9 TVs show the picture in a letterboxed form.
Perfect Pause
This refers to a perfect picture in pause mode. I.e. no noise bars across the screen. It was a feature of the more up-market machines.
PCM
Stands for Pulse Code Modulation and is a way of digitally encoding data. Specifically it is a system used to record high quality digital audio on to the Betamax video format. The picture if viewed on a television would show black and white dancing around in an almost static interference type pattern. When connected to a PCM unit, this image is converted to a digital audio stream. A number of Betamax units came with a switch at the rear to allow the unit to work more efficiently when recording a digital audio "picture", the switch is used to remove the drop out compensator circuitry on playback to allow the PCM unit to carry out its own error correction on the signal without the player altering the signal. For normal video playback, the should not be switched on. See also the PCM feature for further information.
Phono Connector
Also known as an RCA connector this is the standard audio connector on most Betamax VCRs.
Piano Key
This refers to VCRs where the deck operations are carried out by old fashioned mechanical buttons and levers.
Pinch Roller
The is the rubber roller which pulls the tape through the VCR. It operates in a similar fashion to an audio deck. For reliable operation the Pinch Roller must be clean and free from oxide build up. See also the pinch roller page.
Pixel
Short for Picture Element. The basic unit from which a video or computer picture is made. Essentially a dot with a given colour and brightness value. D1 images are 720 pixels wide by 486 high. NTSC images are 640 by 480 pixels.
Portable
A portable VCR is one which could be used outdoors from an internal battery source and connected to a camera. E.g. SL-F1.
Pre-recorded Tapes
These are tapes which come ready to watch. Usually sell-through films or ex-rental tapes. See also the for sale page.
Pre-Roll
This refers to the sequence of events before and edit begins during which the plyer and recording VTRs are synchronised.
R-Y signal
A chrominance signal determined by subtracting the Y (luminance) signal from the R (red) signal. One of the component signals.
Reference video signal
A video signal consisting of a sync signal or sync and burst signals, used as a reference.
Resolution
The amount of detail in an image. Higher resolution equals more detail. Generally expressed in "lines". It is the number of VERTICAL line pairs that the system can distinguish, and has no relationship to the number of horizontal scan lines. Also used to describe the size of a computer image, usually in pixels.
Resolution Independent
A term to describe equipment that can work in more than resolution. For example, most equipment can do film resolution or video resolution, but not both. Resolution independent equipment can work in both.
RGB
Red, Green, Blue. The primary colours of light. Computers and some analogue component devices use separate red, green, and blue colour channels to keep the full bandwidth and therefore the highest quality picture.
Reels
These are the two teethed gears that turn the spools of the cassette.
Remote Control
The ability to operate the VCR from afar. Usually using a infra-red handset, although early models employed a wired system. See also the remote control gallery.
Remote connector
This is either the 36-pin parallel or 9-pin serial connector on the back of a U-matic VTR through which the machine is controlled by an external device. See also the U-matic RX-707 the RM-440 and the RX-303.
Reverse Play
The ability to play the tape backwards. See also speed controls.
RS-422C
Standard serial data transmission format. It uses a 9 pin serial control port superceeding the older 36-pin interface.
Sampling Frequency
The number of sample measurements taken from an analogue signal in a second, generally expressed in megahertz. These samples are then converted into digital numeric values to create the digital signal.
SECAM
French T.V. Standard (Sequentiel Couleur a Memoire). Compare with NTSC and PAL.
Servo
This is a term used to describe the electronic control systems of the VCR which keep the head and capstan motors running in correct synchronisation.
Shell
This is the plastic case which comprises the housing of a video cassette. See also the tapes page.
SIN ratio
Abbreviation of Signal-to-Noise ratio. The higher the S/N ratio, the less noise and higher the picture quality.
Search mode
A VTR mode used when searching for specific scenes, by viewing the video output or time codes while playing back the tape at various speeds in forward or reverse direction.
Servo lock
Synchronising the drum rotation phase and tape transport phase with a reference signal during playback and recording so that the video heads scan the tape in the same pattern during playback and recording.
Skew
This refers to a tape tracking adjustment. If the playback pictures suffers from 'hooking' then the SKEW setting is incorrect will need to be adjusted.
Slave
The VTR used as a player in an edit suite. Usually a play only (VO series) machine.
Slow Speed Playback
The ability to playback pictures at slow speeds. See also speed controls.
SMPTE
Society of Motion Picture and Television Engineer. A major standards-setting organisation for the motion picture and television industries. Established the standards for time code and for all the major video tape formats.
Sub-carrier
The signal on which the video colour information is carried. Equal to 6.85991MHz Lo-Band/9.83803MHz Hi-Band.
Super Betamax
This was an improved Betamax format. Both chromiance and luminance of the format were improved by extending the dynamic range. The mode required special formulation Pro-X tapes. An example of a super betamax is the SL-HF950.
Superimpose
To put a picture (or a set of characters) onto another so that both can be seen at the same time.
SP
Superior Performance. U-matic format variant using chrome tape offering improved colour and black and white detail (resolution) and better separation of colours.
Standard U-matic
Recording in which the luminance FM deviation is from 3.8 to 5.4 MHz and the colour under frequency is 685 kHz. Also known as Low band. See also PALsite's U-matic site.
S-video Input connector
A connector that inputs Y (luminance) and C (chrominance) signals separately to reduce interference between Y and C signals, and to help reproduce noiseless images.
Sync signal
A reference signal consisting of vertical and horizontal sync signals used for synchronising the scanning patterns of the video camera and the monitor.
Tape Guides
This refers to the rollers and other items which guide the tape through its way inside the VCR. See also the shuttle block assembly.
Tape Path
This is the path the takes as it passes through the VCR. Typically the tape will pass the full-track erase head, video drum, audio head and pinch roller. Because the tape passes over many components there is potential for wear and tear. This is especially true when inserting and ejecting the tape. Beta tape path, U-matic tape path, Betacam tape path.
TBC
Abbreviation of Time Base Corrector. Electronic circuits to electrically stabilise the playback signals by removing colour variation and roll in the playback picture caused by irregularity in drum rotation and tape movement. Time base correction reduces deterioration of picture quality when transmitting or copying playback signals.
Telecine
A device that creates video from motion picture film.
Terabyte
1 trillion bytes.
Time Base Corrector
A device for removing jitter (time base errors) from the signal played back by a VTR (essential if using a special effects generator/vision mixer).
Time Code
A time reference recorded on tape to identify each frame. Longitudinal Time Code (LTC). Absolute address for each frame in hours, minutes, seconds and frames recorded on a dedicated (address) track used by BVU. Vertical Interval Time Code (VITC). The same as above but recorded in the vertical interval on lines 17 and 18 by the video heads.
Timer
This is the clock unit inside the VCR which is used to make recodrings automatically. A multi-event timer is simply a timer which can be set for several occasions.
Tracking
Electrically controlling the video head so that the playback phase matches the recording phase of the tape. Especially when playing back the tape with a VTR other than the one used for recording, adjusting the tracking prevents noise from appearing on the picture.
Trick Modes
This is a generic name for the variable speed playback modes on a VCR. See also speed controls.
Tuner
This is the receiver part of the video which decodes off-air broadcast signals.

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