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Video Mix/Effects
M/Es and Keyers
An M/E is a subsystem of a video production switcher that can create a composite of two or
more pictures. An M/E includes multiple source selection buses and provides transition
(mix and wipe) and keying capabilities on the selected signals. K-Frame systems come in
six-keyer (K-Frame Standard and Compact, and GV K-Frame X) and four-keyer (S-series and
V-series) systems.
Six Keyer System Example
Keyers are used to insert part of one picture into another to create a composite picture.
Keying involves three signals:
• background,
• key cut, used to specify where to cut a hole in the background, and
• key fill, used to fill the hole in the background. The fill can be an incoming video signal
or it can be an internally generated matte.
A separate key cut input signal is not necessarily required for keying. For example, a self key
(also called a video key) uses the same input signal for both key cut and key fill.
The GV Switcher system supports the following types of keys:
• Linear Key (fixed and adjustable)
• Luminance Key