// made non-static so that playing can be stopped here
private void Callback(IntPtr hWaveOut, WaveInterop.WaveMessage uMsg, IntPtr dwInstance, WaveHeader wavhdr, IntPtr dwReserved)
{
if (uMsg == WaveInterop.WaveMessage.WaveOutDone)
{
GCHandle hBuffer = (GCHandle)wavhdr.userData;
WaveOutBuffer buffer = (WaveOutBuffer)hBuffer.Target;
Interlocked.Decrement(ref queuedBuffers);
Exception exception = null;
// check that we're not here through pressing stop
if (PlaybackState == PlaybackState.Playing)
{
// to avoid deadlocks in Function callback mode,
// we lock round this whole thing, which will include the
// reading from the stream.
// this protects us from calling waveOutReset on another
// thread while a WaveOutWrite is in progress
lock (waveOutLock)
{
try
{
if (buffer.OnDone())
{
Interlocked.Increment(ref queuedBuffers);
}
}
catch (Exception e)
{
// one likely cause is soundcard being unplugged
exception = e;
}
}
}
if (queuedBuffers == 0)
{
if (callbackInfo.Strategy == WaveCallbackStrategy.FunctionCallback && playbackState == PlaybackState.Stopped)
{
// the user has pressed stop
// DO NOT raise the playback stopped event from here
// since on the main thread we are still in the waveOutReset function
// Playback stopped will be raised elsewhere
}
else
{
RaisePlaybackStoppedEvent(exception);
}
}
}
}
/// <summary>
/// Initialises the WaveOut device
/// </summary>
/// <param name="waveProvider">WaveProvider to play</param>
public void Init(IWaveProvider waveProvider)
{
waveStream = waveProvider;
int bufferSize = waveProvider.WaveFormat.ConvertLatencyToByteSize((DesiredLatency + NumberOfBuffers - 1) / NumberOfBuffers);
MmResult result;
lock (waveOutLock)
{
result = callbackInfo.WaveOutOpen(out hWaveOut, DeviceNumber, waveStream.WaveFormat, callback);
}
MmException.Try(result, "waveOutOpen");
buffers = new WaveOutBuffer[NumberOfBuffers];
playbackState = PlaybackState.Stopped;
for (int n = 0; n < NumberOfBuffers; n++)
{
buffers[n] = new WaveOutBuffer(hWaveOut, bufferSize, waveStream, waveOutLock);
}
}
