Grass Valley Dictionary

Dictionary of Technical Terms - O

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Outside broadcast. A remote broadcast.

A mobile truck, van, or trailer that houses a remote broadcast switching and control center for broadcasting news and sports.

1. Signals that are not currently going out to broadcast or videotape recording. 2. Signals received "out of the air" from a transmitter. To record signals off the air.

Not in use. Inactive.

off-line editing

Editing that is done using inexpensive, non-broadcast-quality equipment to produce an edit decision list (EDL) which will be used later for assembling a broadcast-quality program using more expensive, high-quality equipment.

The unit of resistance. The electrical resistance between two points of a conductor where a constant difference of potential of 1 volt applied between these points produces in the conductor a current of 1 ampere, the conductor not being the source of any electromotive force.

Grass Valley Group trademarked name for the keying system used in the Model 300 switcher.

Open network architecture.

The video signal in question is being broadcasted or videotaped. In Kaleidoscope, a portion of a channel's picture is on screen or its output is being combined with another digital effects processor to create the final video output.

on-edge switching

A digital picture manipulator term meaning to switch input crosspoints (video sources) when the back (hidden) side of a double-sided transformed image rotates to the front and the front (visible) side rotates to the back. The switching occurs at the moment when only the edge of the image is visible.

In use. Active.

on-line editing

Final editing session in which the finished program master is assembled from the original production material.

one-shot (monostable multivibrator)

A circuit that produces an output signal of fixed duration when an input signal of any duration is applied.

Setting edit points while VTRs are rolling. A non-precision method of editing similar to live video switching.

open-ended edit

Edit that has a start time but no designated out-point. An edit that runs until stopped by the operator.

operating program

The program (software or firmware) that controls a computer's functions.

optical waveguide

An optical fiber with a high refractive index clad with a material having a lower index of refraction.

A coupling device consisting of a light emitter and a photodetector used to couple signals without any electrical connection. Used for voltage and noise isolation between input and output while transfer- ring the desired signal.

A transform which causes an object to move in a circle around a point on the X-Y grid.

Diodes arranged in such a way as to construct an OR gate.

orthogonal sampling

Sampling of a line of repetitive video signal in such a way that samples in each line are in the same horizontal position.

An electronic device that generates alternating-current at a frequency determined by the values of the components in its circuits.

Open systems interconnection.

Originating service office.

Optical time domain reflectometer. A device that tests losses in optical fiber.

An edit out-point. The first frame that is not recorded (after the end of an edit).

Edit out-point timing.

The current, voltage, power, or driving force delivered by a circuit or device.

output impedance

The impedance a device presents to its load. The impedance measured at the output terminals of a transducer with the load disconnected and all impressed driving forces taken as zero.

output return loss

See return loss.

In electronic equipment, the final stage that produces the finished output signal(s).

output to output isolation

The ratio of attenuation provided by the output stage to an interfering signal driving one output compared to a second output. The ratio is measured at the second output. A good specification protects output signals against incorrect cabling, such as accidental untermination or double termination.

outside broadcast

A remote broadcast, typically from a remote truck.

ovenized crystal oscillator (OXO)

A crystal oscillator that is surrounded by a temperature regulated heater (oven) to maintain a stable frequency in spite of external temperature variations.

1. In audio or video, a signal that is superimposed over a second signal. Also called voice over in audio. 2. In video switchers, a selection that determines which key layer appears on top of the other key layer in a mix/effects.

A video monitor condition in which the raster extends slightly beyond the physical edges of the CRT screen, cutting off the outer edges of the picture.

The first maximum excursion of a pulse beyond the 100% level. That portion of a pulse that exceeds its defined level temporarily before settling to the correct level. Overshoot amplitude is expressed as a percentage of the defined level. See also ringing.

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