/// <summary>
/// Initializes the capture device. Must be called on the UI (STA) thread.
/// If not called manually then StartRecording() will call it internally.
/// </summary>
public async Task InitAsync()
{
if (captureState == WasapiCaptureState.Disposed)
{
throw new ObjectDisposedException(nameof(WasapiCaptureRT));
}
if (captureState != WasapiCaptureState.Uninitialized)
{
throw new InvalidOperationException("Already initialized");
}
/* var icbh = new ActivateAudioInterfaceCompletionHandler(ac2 => InitializeCaptureDevice((IAudioClient)ac2));
* IActivateAudioInterfaceAsyncOperation activationOperation;
* // must be called on UI thread
* NativeMethods.ActivateAudioInterfaceAsync(device, IID_IAudioClient2, IntPtr.Zero, icbh, out activationOperation);
*
* audioClient = new AudioClient((IAudioClient)(await icbh));
*
* hEvent = NativeMethods.CreateEventExW(IntPtr.Zero, IntPtr.Zero, 0, EventAccess.EVENT_ALL_ACCESS);
* audioClient.SetEventHandle(hEvent);*/
var icbh = new ActivateAudioInterfaceCompletionHandler(ac2 =>
{
if (this.audioClientProperties != null)
{
IntPtr p = Marshal.AllocHGlobal(Marshal.SizeOf(this.audioClientProperties.Value));
Marshal.StructureToPtr(this.audioClientProperties.Value, p, false);
ac2.SetClientProperties(p);
Marshal.FreeHGlobal(p);
// TODO: consider whether we can marshal this without the need for AllocHGlobal
}
InitializeCaptureDevice((IAudioClient2)ac2);
audioClient = new AudioClient((IAudioClient2)ac2);
hEvent = NativeMethods.CreateEventExW(IntPtr.Zero, IntPtr.Zero, 0, EventAccess.EVENT_ALL_ACCESS);
audioClient.SetEventHandle(hEvent);
});
IActivateAudioInterfaceAsyncOperation activationOperation;
// must be called on UI thread
NativeMethods.ActivateAudioInterfaceAsync(device, IID_IAudioClient2, IntPtr.Zero, icbh, out activationOperation);
await icbh;
captureState = WasapiCaptureState.Stopped;
}
/// <summary>
/// Dispose
/// </summary>
public void Dispose()
{
if (captureState == WasapiCaptureState.Disposed)
{
return;
}
try
{
StopRecording();
NativeMethods.CloseHandle(hEvent);
audioClient?.Dispose();
}
catch (Exception ex)
{
Debug.WriteLine("Exception disposing WasapiCaptureRT: " + ex.ToString());
}
hEvent = IntPtr.Zero;
audioClient = null;
captureState = WasapiCaptureState.Disposed;
}
private void DoRecording()
{
Debug.WriteLine("Recording buffer size: " + audioClient.BufferSize);
var buf = new Byte[audioClient.BufferSize * bytesPerFrame];
int bufLength = 0;
int minPacketSize = waveFormat.AverageBytesPerSecond / 100; //100ms
try
{
AudioCaptureClient capture = audioClient.AudioCaptureClient;
audioClient.Start();
int packetSize = capture.GetNextPacketSize();
while (captureState == WasapiCaptureState.Recording)
{
IntPtr pData = IntPtr.Zero;
int numFramesToRead = 0;
AudioClientBufferFlags dwFlags = 0;
if (packetSize == 0)
{
if (NativeMethods.WaitForSingleObjectEx(hEvent, 100, true) != 0)
{
throw new Exception("Capture event timeout");
}
}
pData = capture.GetBuffer(out numFramesToRead, out dwFlags);
if ((int)(dwFlags & AudioClientBufferFlags.Silent) > 0)
{
pData = IntPtr.Zero;
}
if (numFramesToRead == 0)
{
continue;
}
int capturedBytes = numFramesToRead * bytesPerFrame;
if (pData == IntPtr.Zero)
{
Array.Clear(buf, bufLength, capturedBytes);
}
else
{
Marshal.Copy(pData, buf, bufLength, capturedBytes);
}
bufLength += capturedBytes;
capture.ReleaseBuffer(numFramesToRead);
if (bufLength >= minPacketSize)
{
if (DataAvailable != null)
{
DataAvailable(this, new WaveInEventArgs(buf, bufLength));
}
bufLength = 0;
}
packetSize = capture.GetNextPacketSize();
}
}
catch (Exception ex)
{
RaiseRecordingStopped(ex);
Debug.WriteLine("stop wasapi");
}
finally
{
RaiseRecordingStopped(null);
audioClient.Stop();
}
Debug.WriteLine("stop wasapi");
}
