private void initRecorder()
{
Encoding encoding = Encoding.Pcm16bit;
shortsBuffer = new short[bufferSize];
buffer = new byte[bufferSize];
audioRecorder = new AudioRecord(
// Hardware source of recording.
AudioSource.VoiceCommunication,
// Frequency
sampleRate,
// Mono or stereo
ChannelIn.Mono,
// Audio encoding
encoding,
// Length of the audio clip.
bufferSize * 5
);
audioRecorder.StartRecording();
if (AcousticEchoCanceler.IsAvailable)
{
echoCanceller = AcousticEchoCanceler.Create(audioRecorder.AudioSessionId);
}
if (NoiseSuppressor.IsAvailable)
{
noiseSuppressor = NoiseSuppressor.Create(audioRecorder.AudioSessionId);
}
}
/// <summary>
/// Constructs an instance of the WebRtcFilter.
/// </summary>
/// <param name="expectedAudioLatency">The expected audio latency in milliseconds</param>
/// <param name="filterLength">The length of the echo cancellation filter in milliseconds</param>
/// <param name="recordedAudioFormat">The audio format into which the recorded audio has been transformed prior to encoding (e.g., not the raw audio)</param>
/// <param name="playedAudioFormat">The audio format which the audio must be transformed after decoding and before playing</param>
/// <param name="enableAec">Whether to enable acoustic echo cancellation</param>
/// <param name="enableDenoise">Whether to enable denoising</param>
/// <param name="enableAgc">Whether to enable automatic gain control</param>
/// <param name="playedResampler">The resampler which should be used on played audio</param>
/// <param name="recordedResampler">The resampler which should be used on recorded audio</param>
public WebRtcFilter(int expectedAudioLatency, int filterLength,
AudioFormat recordedAudioFormat, AudioFormat playedAudioFormat,
bool enableAec, bool enableDenoise, bool enableAgc,
IAudioFilter playedResampler = null, IAudioFilter recordedResampler = null) :
base(expectedAudioLatency, filterLength, recordedAudioFormat, playedAudioFormat, playedResampler, recordedResampler)
{
// Default settings.
var aecConfig = new AecConfig(FilterLength, recordedAudioFormat.SamplesPerFrame, recordedAudioFormat.SamplesPerSecond)
{
NlpMode = AecNlpMode.KAecNlpModerate,
SkewMode = false,
MetricsMode = false
};
_ns = new NoiseSuppressor(recordedAudioFormat);
_aec = new AecCore(aecConfig);
if (aecConfig.NlpMode != AecNlpMode.KAecNlpConservative &&
aecConfig.NlpMode != AecNlpMode.KAecNlpModerate &&
aecConfig.NlpMode != AecNlpMode.KAecNlpAggressive)
{
throw new ArgumentException();
}
_aec.targetSupp = WebRtcConstants.targetSupp[(int)aecConfig.NlpMode];
_aec.minOverDrive = WebRtcConstants.minOverDrive[(int)aecConfig.NlpMode];
if (aecConfig.MetricsMode && aecConfig.MetricsMode != true)
{
throw new ArgumentException();
}
_aec.metricsMode = aecConfig.MetricsMode;
if (_aec.metricsMode)
{
_aec.InitMetrics();
}
_enableAec = enableAec;
_enableDenoise = enableDenoise;
_enableAgc = enableAgc;
_agc = new Agc(0, 255, Agc.AgcMode.AgcModeAdaptiveDigital, (uint)recordedAudioFormat.SamplesPerSecond);
}
public void stop()
{
if (!running)
{
return;
}
running = false;
if (echoCanceller != null)
{
try
{
echoCanceller.Release();
echoCanceller.Dispose();
}
catch (Exception)
{
}
echoCanceller = null;
}
if (noiseSuppressor != null)
{
try
{
noiseSuppressor.Release();
noiseSuppressor.Dispose();
}
catch (Exception)
{
}
noiseSuppressor = null;
}
if (audioRecorder != null)
{
try
{
audioRecorder.Stop();
audioRecorder.Release();
}
catch (Exception)
{
}
audioRecorder.Dispose();
audioRecorder = null;
}
if (audioEncoder != null)
{
audioEncoder.stop();
audioEncoder.Dispose();
audioEncoder = null;
}
buffer = null;
shortsBuffer = null;
bufferSize = 0;
lock (outputBuffers)
{
outputBuffers.Clear();
}
AudioManager am = (AudioManager)MainActivity.Instance.GetSystemService(Context.AudioService);
if (Build.VERSION.SdkInt < BuildVersionCodes.O)
{
if (focusListener != null)
{
#pragma warning disable CS0618 // Type or member is obsolete
am.AbandonAudioFocus(focusListener);
#pragma warning restore CS0618 // Type or member is obsolete
focusListener.Dispose();
focusListener = null;
}
}
else
{
if (focusListener != null)
{
if (focusRequest != null)
{
am.AbandonAudioFocusRequest(focusRequest);
focusRequest.Dispose();
focusRequest = null;
}
focusListener.Dispose();
focusListener = null;
}
}
}
