private AudioTrack GetAudioTrack()
{
ChannelOut channelOut = _channels == 2 ? ChannelOut.Stereo : ChannelOut.Mono;
Encoding encoding = Encoding.Pcm16bit;;
int bufferSize = AudioTrack.GetMinBufferSize(_sampleRate, channelOut, encoding) * 2;
AudioTrack audioTrack;
AudioAttributes.Builder attributesBuilder = new AudioAttributes.Builder()
.SetUsage(AudioUsageKind.Game);
AudioFormat format = new AudioFormat.Builder()
.SetEncoding(encoding)
.SetSampleRate(_sampleRate)
.SetChannelMask(channelOut)
.Build();
if (Build.VERSION.SdkInt < BuildVersionCodes.O)
{
attributesBuilder.SetFlags(AudioFlags.LowLatency);
}
if (Build.VERSION.SdkInt >= BuildVersionCodes.O)
{
AudioTrack.Builder trackBuilder = new AudioTrack.Builder()
.SetAudioFormat(format)
.SetAudioAttributes(attributesBuilder.Build())
.SetTransferMode(AudioTrackMode.Stream)
.SetBufferSizeInBytes(bufferSize);
trackBuilder.SetPerformanceMode(AudioTrackPerformanceMode.LowLatency);
audioTrack = trackBuilder.Build();
}
else
{
audioTrack = new AudioTrack(attributesBuilder.Build(),
format,
bufferSize,
AudioTrackMode.Stream,
AudioManager.AudioSessionIdGenerate);
}
return(audioTrack);
}
/// <summary>
/// Replays recorded audio by microphone.
/// </summary>
/// <param name="UIDispatcher">UIDispatcher needed for UWP platform.</param>
public async void ReplayRecording(CoreDispatcher UIDispatcher)
{
#region UWP
#if NETFX_CORE
// Do nothign without buffer
if (buffer == null)
{
return;
}
MediaElement playback = new MediaElement();
IRandomAccessStream audioBuffer;
lock (bufferLock)
{
audioBuffer = buffer.CloneStream();
}
if (audioBuffer == null)
{
throw new ArgumentNullException("buffer");
}
// Replay async
await UIDispatcher.RunAsync(CoreDispatcherPriority.Normal, async() =>
{
playback.SetSource(audioBuffer, "");
playback.Play();
});
#endif
#endregion
#region ANDROID
#if __ANDROID__
// Setup AudioTrack
ChannelOut channels = Parameters.Channels == 1 ? ChannelOut.Mono : ChannelOut.Stereo;
AudioTrack audioTrack = new AudioTrack.Builder()
.SetAudioAttributes(new AudioAttributes.Builder()
.SetUsage(AudioUsageKind.Media)
.SetContentType(AudioContentType.Music)
.Build())
.SetAudioFormat(new AudioFormat.Builder()
.SetEncoding(Encoding.Pcm16bit)
.SetSampleRate((int)Parameters.SamplingRate)
.SetChannelMask(channels)
.Build())
.SetBufferSizeInBytes(buffer.Length)
.Build();
int totalBytesReplayed = 0;
// Replay audio in lock until whole buffer is replayed
lock (bufferLock)
{
audioTrack.Play();
while (totalBytesReplayed < bufferLimit)
{
try
{
totalBytesReplayed = audioTrack.Write(buffer, 0, bufferLimit);
System.Diagnostics.Debug.WriteLine($"Read: {totalBytesReplayed}");
if (totalBytesReplayed < 0)
{
throw new Exception(String.Format("Exception code: {0}", totalBytesReplayed));
}
}
catch (Exception e)
{
// Invalidate audio buffer
buffer = null;
break;
}
}
}
#endif
#endregion
}
