/// <summary>
/// Updates the signal quality
/// </summary>
public void UpdateSignalQuality()
{
_tunerLocked = false;
_signalLevel = 0;
_signalQuality = 0;
try
{
AMTunerSignalStrength signalStrength;
_tuner.SignalPresent(out signalStrength);
// Some tuners (in particular, cards based on the Philips/NXP
// SAA713x and SAA716x PCI-e bridge chipsets such as the Hauppauge
// HVR2200) report values outside the range specified by the DirectShow
// interface when they are locked. This means it is best to assume the
// tuner is locked unless the tuner reports no signal.
// See Mantis #0002445.
_tunerLocked = (signalStrength != AMTunerSignalStrength.NoSignal);
}
catch (TvExceptionSWEncoderMissing)
{
Log.Log.Error("UpdateSignalQuality: unable to perform the check because of a missing audio/video encoder!");
}
if (_tunerLocked)
{
_signalLevel = 100;
_signalQuality = 100;
}
else
{
_signalLevel = 0;
_signalQuality = 0;
}
}
public void TestSignalPresent()
{
int hr = 0;
AMTunerSignalStrength sig;
hr = tuner.SignalPresent(out sig);
DsError.ThrowExceptionForHR(hr);
Debug.Assert(hr == 0, "IAMTVTuner.SignalPresent");
}
/// <summary>
/// Returns the AMTunerSignalStrength for the currently tuned channel
/// </summary>
protected override int GetSignalStrength()
{
if (_amTvTuner != null)
{
int hr;
AMTunerSignalStrength signalStrength;
hr = _amTvTuner.SignalPresent(out signalStrength);
DsError.ThrowExceptionForHR(hr);
return((int)signalStrength);
}
else
{
return((int)AMTunerSignalStrength.HasNoSignalStrength);
}
}
