correction. For example, if you increase the red gamma
correction to the part of the video signal that has no red
component you will add red to those areas while having
little effect on areas that already contain a significant
amount of red. This allows you to add a red tint to the
image while minimizing the amount of red-clipping that
occurs.
General Purpose Interface
A simple high/low signal that is used to trigger an action
either on an external device or on the switcher. A GPI
can be an input or an output to the switcher.
High Definition
A high definition (720p, 1080i, or 1080p/3G) video
signal.
Hue
The characteristic of a color signal that determines
whether the color is red, yellow, green, blue, purple, etc.
(the three characteristics of a TV color signal are
chrominance, luminance, and hue). White, black, and
gray are not considered hues.
Hue Rotation
Hue rotate affects the color of the entire video signal by
rotating the input video hues. This produces an output
video signal with colors that are shifted from their
original hues. By rotating colors around the wheel, hue
values will shift. For example, a clockwise rotation where
yellows become orange, reds become magenta, blues
become green. The more rotation applied, the further
around the wheel colors are shifted.
Key
An effect produced by cutting a hole in the background
video, then filling the hole with video or matte from
another source. Key source video cuts the hole, key fill
video fills the hole. The video signal used for cut and fill
can come from the same, or separate, sources.
Key Alpha
The video signal which cuts a hole in the background
video to make a key effect possible. Also called Key
Video or Source. In practice, this signal controls when
a video mixer circuit will switch from background to key
fill video.
Key Invert
An effect that reverses the polarity of the key source so
that the holes in the background are cut by dark areas of
the key source instead of bright areas.
Key Mask
A keying technique in which a shape is combined with
the key source to block out unwanted portions of the key
source.
Key Video
A video input which is timed to fill the hole provided by
the key source video. An example of key video is the
video output of a character generator.
Linear Key
Linear keys make it possible to fully specify the
transparency of a key from opaque, through transparent,
to fully off. The transparency is specified by the key
alpha that is associated with the key video. A keyer
capable of a linear key converts the key signal voltage
directly to the transparency effect on the screen.
Mnemonics
A green, orange, or yellow display used to show the
names of a source above or below the source button or
used as a custom command or pattern button.
Offsets
Offsets shift the video signal by a set amount. Depending
on the offset applied, different parts or all of the video
signal may be affected. Clipping occurs if applied offsets
cause output signal values to fall outside the allowable
range.
Pre-Delay
A pre-delay is a delay that is inserted into a transition
between the triggering of a GPI output and performing
the transition. The length of the pre-delay is usually the
length of time your video server requires to start playing
a clip or your character generator required to load a page.
RossTalk
An ethernet based protocol that allows the control over
Ross devices using plain english commands.
Standard-Definition
A standard definition (480i or 576i) video signal.
Self Key
A key effect in which the same video signal serves as
both the key signal and key fill.
Shaped Key
An additive key where the Key Alpha cuts a hole based
on the monochrome value of the alpha. Shades of gray
are translated into either white or black, giving the key
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• Glossary — Carbonite Operation Manual (v13.0)