Programming Manual
PHYTEC Messtechnik GmbH 2008 L-720e_0
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De/Activation of the AGC
void Set_AGC(WORD nDevNo,WORD nCAGC, WORD nAGC,
WORD nChrush);
nCAGC: 0 = chroma AGC off
1 = chroma AGC on
nAGC:
0 = AGC on
1 = AGC off
nCrush: 0 = none-adaptive AGC
1 = adaptive AGC
The pciGrabber-4x4 contains two AGCs. The common AGC controls
the signal level of the composite- or Y signal and controls correspond-
ingly the input amplitude. In addition the chroma AGC controls the
adaptation of the amplitude of the color signal. For the AGC the mo-
dus
Adaptive AGC
is available. In this case the overflow bit of the
A/D converter is monitored. If an overflow occurs, automatically the
A/D reference voltage is increased, which causes an increase of the
input voltage range.
In general, operating the pciGrabber-4x4 with a non-adaptive gain
control will suffice.
In some applications the adaptive AGC might cause disturbances (e.g.
this is the case when working with absolute brightness values). Then
the non-adaptive AGC should be used.
When using applications that switch between multiple cameras
(i.e. video monitoring), the switch time between cameras can be
reduced, under certain circumstances, by using adaptive AGC.
Note:
The standard AGC may
not
be switched off.
