Grass Valley Karrera Video Production Center v.4.0 - Manual (Page 353)

KARRERA — User Manual 353
Glossary
Auto Transition
A transition having a predefined duration
generally initiated by pressing a control pan-
el button.
Aspect
The ratio of a picture’s horizontal and verti-
cal dimensions when correctly displayed
(4:3, 16:9).
Background Bus
A row of buttons on an ME used to select
background video signals. Typically labeled
A and B, with A representing the current out-
put, and B representing the next output.
Background Transition
A transition between the background video
signals selected on an ME.
Background Video
Video that forms a background scene into
which a key may be inserted.
Backing Color
The color in a chroma key scene that will be
replaced with another video signal.
Bit Rate
The number of bits per second passed from
one point to another.
Black
A black video signal generated within the
switcher.
Box Wipe
A rectangular wipe pattern. For masking, the
Karrera system provides a special box wipe
pattern generator allowing independent con-
trol of the placement of each side of the box.
Chroma
The depth or saturation of color. Chroma,
hue, and luminance make up the three char-
acteristics of television color.
Chroma Key
A video key effect in which one video signal
is inserted in place of areas of a particular
color in another video signal. Blue and green
are the chroma key colors most frequently
used.
Clean Feed
A final output of the switcher that does not
include downstream key effects or fade to
black. Also see
Programmable Clean Feed .
Clip
A threshold level adjustment to which the
keying attribute (luminance, chrominance) is
compared for generating the internal key
control signal. Clip, in conjunction with gain,
sets the switching point between the back-
ground and the key fill. Also see
Gain .
Clip High, Clip Low
An alternative to Clip and gain keying, pro-
viding independent control of the points
where the background video and the key fill
video are each fully visible.
Complex Wipe Pattern Generator
A wipe pattern generator with additional ca-
pabilities (for example, matrix wipes).
Component Video
A video signal that keeps color and lumi-
nance information separate. RGB; Y, R-Y, B-Y;
and Y, Cr, Cb are examples of component
video.