/// <summary>
/// Writes a data event into the adapter. The given event's buffer is not copied, but stored as reference.
/// <see cref="Read(byte[], int, int)"/> must be called immediately to consume this event. Otherwise the event's buffer might become invalid.
/// </summary>
/// <param name="dataEvent"></param>
public void Write(StreamAudioSourceDataEvent dataEvent)
{
this.Data = dataEvent;
DataOffset = 0;
}
/// <summary>
/// Called when <see cref="WrappedAudioSource"/> raises <see cref="IStreamAudioSource.DataAvailable"/>.
/// Processing is happening here: checks on the volume of the received samples and passes the event on to <see cref="DataAvailable"/> if appropriate.
/// </summary>
/// <param name="data"></param>
protected void OnSourceDataAvailable(StreamAudioSourceDataEvent data)
{
var options = this.Options;
var samples = data.Samples;
bool logStatistics = AnalyticsLoggingEnabled && (!AnalyticsLoggedOnce || SamplesToTime(AnalyticsSampleCount, data.Format) > TimeSpan.FromMinutes(10));
float statisticsMax = float.MinValue, statisticsMin = float.MaxValue;
//evaluate the received samples
bool overThreshold = false;
foreach (var sample in samples)
{
var amplitude = GetNormalizedSampleValue(sample, data.Format);
if (amplitude > options.VolumeThreshold)
{
overThreshold = true;
if (!logStatistics)
{
break;
}
}
if (amplitude > statisticsMax)
{
statisticsMax = amplitude;
}
if (amplitude < statisticsMin)
{
statisticsMin = amplitude;
}
}
//print analytics every now and then
if (logStatistics && samples.Count > 0)
{
Logger.LogTrace($"NoiseGate min|max levels: {statisticsMin}|{statisticsMax}");
AnalyticsLoggedOnce = true;
AnalyticsSampleCount = 0;
}
AnalyticsSampleCount += samples.Count;
//pass through or mute
if (overThreshold)
{
//pass through
SamplesUnderThreshold = 0;
StopRequested = false;
Muted = false;
DataAvailable?.Invoke(this, data);
}
else
{
SamplesUnderThreshold += samples.Count;
bool mute = Muted;
if (!mute)
{
//check on the time since we were above the threshold
var thresholdTime = options.Delay;
if (StopRequested && options.DelayStopDetection.TotalMilliseconds >= 0)
{
//reduce our threshold time
thresholdTime = options.DelayStopDetection;
}
if (TimeUnderThreshold >= thresholdTime)
{
mute = true;
}
}
if (mute)
{
Muted = true;
StopRequested = false;
if (!options.ModeCutOff)
{
//return a zeroed buffer
if (ZeroBuffer == null || ZeroBuffer.Length < data.Buffer.Count)
{
ZeroBuffer = new byte[data.Buffer.Count];
}
DataAvailable?.Invoke(this, new StreamAudioSourceDataEvent()
{
Buffer = new ArraySegment <byte>(ZeroBuffer, 0, data.Buffer.Count),
Format = data.Format
});
}
//else: simply do nothing
}
else
{
//pass through
DataAvailable?.Invoke(this, data);
}
}
}
