THOMSON GRASS VALLEY KayakDD-1, User Manual

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KayakDD - Digital Production Switcher
2.6.4 Key Memory
Key parameters can be saved to a separate key memory for every KayakDD system
source. These parameters can be applied automatically whenever that source is
selected.
2.6.5 Buses and Crosspoints
A bus is technically defined as a signal path where one of several available inputs can
be selected to feed a single output. A crosspoint is an electronic switch that allows a
signal to pass when the switch is closed. On video switchers, a bus can be constructed
containing a series of crosspoints, which permits selecting which one of several
incoming signals will be sent out the bus. In
Figure 3 , source 2 has been selected on
the background A bus. This signal can now be called background video and is
available for further processing.
Figure 3 Buses with Crosspoints
Buttons on a control panel can be used to control the switching of crosspoints. The
buttons are usually arranged horizontally, making it easy to imagine the available
signals coming in from the top, and the single bus output signal going out the right
side. In earlier generation switchers, the terms
crosspoint button and crosspoint bus
have been used in reference to control panel source selection.
For a KayakDD system, the terms
source button and source bus will be used.
These terms better reflect a system operating philosophy that is source rather than
crosspoint based.
The KayakDD system does not directly associate a source select button with a
physical crosspoint. The association goes first through source to button mapping, then
through source definition to find the physical inputs.
On the KayakDD system, a single source button can control crosspoints on different
buses simultaneously. For example, during keying, both the video and key signals of a
source can be selected with a single button press.
In this case two different crosspoints on separate buses (key fill bus and key cut bus)
are actually switched when the button is pressed.
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