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SuperVisor LX
SECTION 4
FGAX3249400MANAA
100701
Version 1 Issue 2
4.19
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Keying
Keying
Keying ON/off
Key Mode...
Col Temp...
Key Color...
Calibrate...
Contrast
Keying Overview
Displaying a VGA (PC) signal
The Supervisor LX is equipped to display not only
a video signal but also a VGA signal. A VGA signal
is input via the 15 pin D-Type connector marked
‘Computer Video Input’. There is one important
limitation on displaying a VGA signal – it cannot be
resized.
The simplest way to display a VGA signal is to
select the VGA thru option from the Passthru
menu. When this is selected, the Supervisor LX
outputs the VGA signal in preference to the video
signal. The VGA signal has DC Restoration applied
to it and (optionally) sync inversion. Other than this,
there is no further processing of the VGA signal.
When you switch to VGA thru there is a
momentary loss of output (display will go black).
Likewise when you switch back to video.
There is an alternative way of switching between
video and VGA and that is to take advantage of the
Supervisor LX’s key mode options. But to do this
the unit needs to have keying turned on.
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Keying ON/off
To enable keying, select ‘keying on’ from the
keying menu. This has two important
consequences. Firstly, the output rate of the video
signal is now determined by the rate of the VGA
signal. Thus if the VGA signal is 1024x768 at
72 Hz then the video output rate will be 1024x768
at 72 Hz. (Note that this overrides whatever is
currently selected in the output rate menu).
Secondly (if the key mode is PC + Video), the
video signal will now be chroma keyed with the
VGA signal. This means that wherever the ‘key
color’ appears in the VGA signal, it will be replaced
with video. The default key color is 96, 32, 96 in
RGB terms.
In order to optimise keying it is necessary to run
the Supervisor LX keying setup program. This
must be installed and run on the PC that is
providing the VGA signal. This enables proper
calibration of the video signal with respect to the
VGA signal and it also enables fine-tuning of the
chroma keying. It is also possible to select a
different color as the key color.
Once this has been done, it is possible to properly
view video and VGA simultaneously. The VGA
signal can have its color temperature adjusted as
well as its contrast level (not possible in VGA pass
thru). The video signal can have its full range of
adjustments including resizing.
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Key Mode…
This allows three different keying modes to be
selected.
Key Mode
PC Only
Video Only
PC + Video
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PC Only
In this mode the unit displays only
the VGA signal.
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Video Only
In this mode the unit displays only
the video signal.
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PC + Video This mode enables chroma keying
and hence both video and VGA
can be output simultaneously.
Switching between Key Modes is synchronous
which means that there is no temporary loss of
output.