gsttuner interface for elements that provide tuner operations @klass: @list_channels: @set_channel: @get_channel: @list_norms: @set_norm: @get_norm: @set_frequency: @get_frequency: @signal_strength: @channel_changed: @norm_changed: @frequency_changed: @signal_changed: @_gst_reserved: @tuner: @Returns: @tuner: @Returns: @tuner: @channel: @tuner: @Returns: @tuner: @Returns: @tuner: @norm: @tuner: @channel: @frequency: @tuner: @channel: @Returns: @tuner: @norm: @Returns: @tuner: @channel: @Returns: @tuner: @channel: @tuner: @norm: @tuner: @channel: @frequency: @tuner: @channel: @signal: