Indicates whether a TV signal is present on the current channel (horizontal lock).
SignalPresent provides a more rigorous test for a valid channel than ChannelAvailable. As a result, SignalPresent may return false for some channels that are still viewable.
For TV tuning there are 2 "stages" to locking on to a channel. The first stage is a frequency lock and the second is horizontal lock. A frequency lock occurs when the tuner has detected a correctly modulated data signal that may or may not be a TV signal. A horizontal lock occurs when the decoder has detected a valid TV signal.
The SignalPresent method checks for a horizontal lock on the current channel. The ChannelAvailable method checks for only a frequency lock.
If the signal strength cannot be determined, a NotSupportedException is thrown.
Tuner Class | Tuner Members | DirectX.Capture Namespace