Dictionary of Technical Terms - T
time base correctorDevice used to correct for time base errors and stabilize the timing of the video output from a tape machine.
time base errorHorizontal rate flutter of a video signal caused by tape stretch and inherent imperfections in the tape transport mechanism of a videotape recorder.
time codeTiming code laid down on video-tape to give each frame a unique number so as to ensure exact transitions during editing.
time delayThe time required for a signal to travel through a circuit.
timedThe devices or signals in question are synchronized with one another.
timeline1. An effects control feature that enables the operator of a switcher or digital picture manipulator to preprogram a series of timed events, such as auto transitions, E-MEM recalls, and GPI triggers, and then replay them. 2. A window within a video editing application where clips and other production elements can be graphically arranged to create a fully edited production. The horizontal axis of the timeline window represents a timeline of the show.
time-multiplexIn the case of ITU-R BT.601-2 (CCIR-601), a technique for transmitting three signals at the same time on a group of parallel wires (parallel cable).
timing pulseSee sync pulse.
timing scatterRouting switcher term describing varying electrical lengths.
title inserterSee title key.
title keyA key effect which imposes a caption over a background scene. The source of the title key signal may be a character generator or a graphics camera.
toggleTo change back and forth between two states (for instance: on, off, on, off, etc.) by alternately opening and closing an electric circuit.
toneTypically refers to a single-frequency audio signal used as a level setting reference.
total harmonic distortion (THD)The ratio of the sum of the ampli-tudes of all signals harmonically re-lated to the fundamental and the amplitude of the fundamental signal.
T-pulseA sine-squared pulse used as an indication of frequency and phase response.
T-pulse to barA specification term relating to frequency response of video equipment. A video signal containing equal amplitude T-pulse and bar portions is passed through the equipment and the relative amplitudes of the T-pulse and bar are measured at the output. A loss of response is indicated when one portion of the signal is lower in amplitude than the other.
traceIn telecommunications, an MML command to trace designated ports.
TRACEA GVG trademarked editor program that reads the EDLs from several generations of edits to a show and constructs a final EDL with references back to the original source back to the original source show will be recorded from the original source material, ensuring against multigenerational degradation.
track1. The section of a videotape where a particular signal is recorded. There are separate tracks for video, audio, time code, etc. 2. Levels in the timeline window of an editing application where video and audio elements can be placed to insert them into the production.
trailA digital picture manipulator effect in which an image repeats on screen as it moves so that it appears to leave a trail of duplicate images behind it. If the trail is set to decay mode, the trailing images gradually fade away.
trailing edgeThe transition of a pulse that occurs last, such as the high-to-low transition of a high clock pulse.
transcoderA device that converts one form of encoded video to another, e.g., to convert NTSC video to PAL. Sometimes mistakenly used to mean translator.
transducerA device that converts one form of energy into another. For example, in fiber optics, a device that converts light signals into electrical signals.
transform, transformationIn digital picture manipulators, to digitally change a picture in some way that alters the appearance or location of the picture, such as applying translation, rotation, perspective changes, size changes, aspect and skew manipulations, etc.
transformation pathIn digital picture manipulators, the path or direction and speed that a transformed image follows as it moves from one key frame to the next.
transformerAn electrical device that inductively transfers electrical energy from one circuit to another circuit at the same frequency but usually at a different impedance, voltage, and current.
transientA momentary surge on a signal or power line.
transistorA semiconductor electronic device having three electrodes and used for signal buffering, amplification, etc.
transitionA change from one picture to another. A transition can be a wipe, mix, or cut.
transition interruptSelection of a new preset source with a transition in progress. The switcher removes the old program video in time and remains (if necessary) in black/silent until a newly selected source is ready and placed on-air.
transition status displayA patented GVG device that keys MASTER-21 status into an external television monitor.
translate1. In digital picture manipulators, movement of the image or screen along its X,Y, or Z axis. 2. Changing a video signal from one format to another.
translatorA device used to convert from one component set to another, e.g., to convert Y, R-Y, B-Y signals to RGB signals.
transmitterEquipment used to generate and amplify an RF carrier signal, modulate this carrier with information, and radiate the modulated RF carrier into space.
tray (frame)The metal cabinet that holds circuit boards.
triaxialA special form of coaxial cable containing three conductors.
triggerA pulse that starts an action or function.
trim1. To make a fine adjustment in a circuit or a circuit element. 2. In video editing systems, to add or subtract time code to adjust edit points.
TrompeterBrand of connector. Also a brand of tool for plugging and unplugging BNC connectors.
troughAlso called cable trough. A slot underneath the flooring of a television facility where cables are laid for running from room to room.
TRSTiming reference signals in composite digital systems (four words long).
TRS-IDTiming reference signal identifica-tion. A four-word reference signal used to maintain timing in composite digital systems.
truncationDeletion of lower significant bits on a digital system. Usually results in digital noise.
T-SpanA telephone circuit.
tumbleA transformation in which the picture appears to turn around its X (horizontal) axis. See also flip.
tuned-circuit equalizerA circuit that is adjusted to be resonant at a particular frequency. Equalizer that employs circuits consisting of inductance and capacitance that can be adjusted for resonance at the desired frequency.
twisted pairA cable composed of two small insulated conductors twisted together. Since both wires have nearly equal exposure to any interference, the differential noise is slight.
TWXTeletypewriter exchange service.
TypeDekoA GVG broadcast quality character generator running under Windows NT on the DEC Alpha workstation.