/// <inheritdoc />
public void Start()
{
if (DeviceHandle != IntPtr.Zero || IsDisposed)
{
throw new InvalidOperationException($"{nameof(LegacyAudioPlayer)} was already started");
}
var bufferSize = Renderer.WaveFormat.ConvertMillisToByteSize((DesiredLatency + NumberOfBuffers - 1) / NumberOfBuffers);
// Acquire a device handle
DeviceHandle = WaveInterop.OpenAudioDevice(
DeviceNumber,
Renderer.WaveFormat,
DriverCallbackEvent.SafeWaitHandle,
IntPtr.Zero,
WaveInterop.WaveInOutOpenFlags.CallbackEvent);
// Create the buffers
Buffers = new WaveOutBuffer[NumberOfBuffers];
for (var n = 0; n < NumberOfBuffers; n++)
{
Buffers[n] = new WaveOutBuffer(DeviceHandle, bufferSize, Renderer);
}
// Start the playback thread
DriverCallbackEvent.Set(); // give the thread an initial kick
PlaybackState = PlaybackState.Playing;
StartAsync();
}
/// <summary>
/// Initializes the specified wave provider.
/// </summary>
/// <param name="waveProvider">The wave provider.</param>
/// <exception cref="System.InvalidOperationException">Can't re-initialize during playback</exception>
public void Init(IWaveProvider waveProvider)
{
if (m_PlaybackState != PlaybackState.Stopped)
{
throw new InvalidOperationException("Can't re-initialize during playback");
}
if (DeviceHandle != IntPtr.Zero)
{
// normally we don't allow calling Init twice, but as experiment, see if we can clean up and go again
// try to allow reuse of this waveOut device
// n.b. risky if Playback thread has not exited
DisposeBuffers();
CloseWaveOut();
}
CallbackEvent = new AutoResetEvent(false);
WaveStream = waveProvider;
var bufferSize = waveProvider.WaveFormat.ConvertLatencyToByteSize((DesiredLatency + NumberOfBuffers - 1) / NumberOfBuffers);
MmResult result;
lock (WaveOutLock)
{
result = WaveInterop.NativeMethods.waveOutOpenWindow(
out DeviceHandle,
DeviceNumber,
WaveStream.WaveFormat,
CallbackEvent.SafeWaitHandle.DangerousGetHandle(),
IntPtr.Zero,
WaveInterop.WaveInOutOpenFlags.CallbackEvent);
}
MmException.Try(result, nameof(WaveInterop.NativeMethods.waveOutOpen));
Buffers = new WaveOutBuffer[NumberOfBuffers];
m_PlaybackState = PlaybackState.Stopped;
for (var n = 0; n < NumberOfBuffers; n++)
{
Buffers[n] = new WaveOutBuffer(DeviceHandle, bufferSize, WaveStream, WaveOutLock);
}
}
/// <summary>
/// Begin playback
/// </summary>
public void Start()
{
if (DeviceHandle != IntPtr.Zero || IsDisposed)
{
throw new InvalidOperationException($"{nameof(AudioPlaybackThread)} was already started");
}
PlaybackFinished.Begin();
var bufferSize = Renderer.WaveFormat.ConvertMillisToByteSize((DesiredLatency + NumberOfBuffers - 1) / NumberOfBuffers);
// Acquire a device handle
DeviceHandle = WaveInterop.OpenAudioDevice(
DeviceNumber,
Renderer.WaveFormat,
DriverCallbackEvent.SafeWaitHandle.DangerousGetHandle(),
IntPtr.Zero,
WaveInterop.WaveInOutOpenFlags.CallbackEvent);
// Create the buffers
Buffers = new WaveOutBuffer[NumberOfBuffers];
for (var n = 0; n < NumberOfBuffers; n++)
{
Buffers[n] = new WaveOutBuffer(DeviceHandle, bufferSize, Renderer);
}
// Start the playback thread
DriverCallbackEvent.Set(); // give the thread an initial kick
AudioPlaybackThread = new Thread(PerformContinuousPlayback)
{
IsBackground = true,
Name = nameof(AudioPlaybackThread),
Priority = ThreadPriority.AboveNormal
};
// Begin the thread
AudioPlaybackThread.Start();
}