Tektronix Grass Valley 3000 - Manual (Page 274)

G-12
Glossary
Shadow (Dropshadow): A title
enhancement consisting of a shadow effect
along one edge of the title key or along one
edge and the bottom of the key.
Signal-to-Noise Ratio: A measurement
of the relative amount of noise present in
an audio or video signal.
SMPTE: Society of Motion Picture and
Television Engineers.
SMPTE Component Standard: A color
difference video standard outlined by
SMPTE, expressed in terms of Y, R-Y, and
B-Y.
Soft Edge: A wipe pattern edge between
two video signals in which the signals
dissolve into each other for a soft
transition effect.
Software: Computer programs. (Also
see Hardware and Firmware.)
Split Key: A key mode in which the key
signal and the key video are from different
sources.
Spotlight: A highlight effect produced
by superimposing a full-strength video
signal shaped by a wipe pattern over an
attenuated (darkened) signal from the
same video source.
Subcarrier: A sine wave signal which is
imposed on a video signal as a color
reference. Subcarrier also forms color
burst. The frequency of subcarrier is 3.58
MHz in NTSC and 4.43 MHz in PAL.
Switcher (Vision Mixer): An electronic
device that takes video signals from any of
several sources (such as cameras, VTRs,
character generators, etc.) to combine
video signals and produce video effects.
(Also see Audio Mixer.)
Sync: The portion of an encoded video
signal which occurs during blanking and
is used to synchronize the operation of the
equipment. Horizontal sync occurs during
the blanking period in each horizontal
scanning line, and vertical sync occurs
during the vertical blanking period.
Synchronous: A mode of computer
operation where all tasks, regardless of the
time they take for execution, are allotted
specified time cycles. (Also see
Asynchronous.)
System: A grouping of assemblies which
perform multiple related tasks. (Also see
Assembly and Component.)
T
Terminate, Termination: To complete a
circuit by connecting a resistive load to it.
A video termination is typically a male
BNC connector which contains a 50-ohm
or 75-ohm resistive load. Any unused
looping inputs must be terminated to
ensure proper signal levels.
Time Base Corrector: An electronic
device used to correct video signal
instability.
Title, Caption, Title Key: A key derived
from a title signal generated by a character