public static extern void SetReadDataCallback([In, MarshalAs(UnmanagedType.FunctionPtr)] ReadDataCallback readDataCallback);
/// <summary>
/// Create a PortAudioDevicePump for an output device
/// Note: This MUST be disposed, or you risk breaking audio on the host until the next reboot
/// </summary>
/// <param name="device">The output device to create a pump for</param>
/// <param name="channelCount">The number of channels in the input PCM data</param>
/// <param name="sampleFormat">The sample format of the input PCM data</param>
/// <param name="suggestedLatency">The latency the device will attempt to achieve</param>
/// <param name="sampleRate">The sample rate of playback</param>
/// <param name="callback">The callback that will supply data to the output device</param>
/// <exception cref="ArgumentNullException">Thrown in the case that the device or callback are null</exception>
public unsafe PortAudioDevicePump(PortAudioDevice device, int channelCount, PortAudioSampleFormat sampleFormat,
TimeSpan suggestedLatency, double sampleRate, ReadDataCallback callback)
{
if (device == null)
{
throw new ArgumentNullException(nameof(device));
}
if (callback == null)
{
throw new ArgumentNullException(nameof(callback));
}
PortAudioLifetimeRegistry.Register(this);
SampleFormat = sampleFormat;
Channels = channelCount;
SampleRate = sampleRate;
SuggestedLatency = suggestedLatency;
_handle = GCHandle.Alloc(this);
_isOutput = true;
_readDataCallback = callback;
var outputParams = new PaStreamParameters
{
ChannelCount = channelCount,
DeviceIndex = device.DeviceIndex,
HostApiSpecificStreamInfo = IntPtr.Zero,
SampleFormats = sampleFormat.SampleFormat,
SuggestedLatency = new PaTime(suggestedLatency)
};
var err = Native.PortAudio.Pa_OpenStream(out _stream, null, &outputParams, sampleRate, FRAMES_TO_BUFFER, PaStreamFlags.NoFlag,
StreamCallback, GCHandle.ToIntPtr(_handle));
if (err < PaErrorCode.NoError)
{
throw PortAudioException.GetException(err);
}
err = Native.PortAudio.Pa_SetStreamFinishedCallback(_stream, StreamFinishedCallback);
if (err < PaErrorCode.NoError)
{
throw PortAudioException.GetException(err);
}
_dataQueue = new ConcurrentQueue <BufferContainer>();
_bufferPool = new ConcurrentBag <BufferContainer>();
for (var i = 0; i < BUFFER_CHAIN_LENGTH; i++)
{
var buffer = new byte[FRAMES_TO_BUFFER * (ulong)channelCount * (ulong)sampleFormat.FormatSize];
var readLength = WriteAudioFrame(buffer, buffer.Length);
_dataQueue.Enqueue(new BufferContainer(buffer)
{
ReadLength = readLength
});
}
_queueCount = new SemaphoreSlim(BUFFER_CHAIN_LENGTH);
_poolCount = new SemaphoreSlim(0);
_threadEndEvent = new ManualResetEventSlim(false);
_processingThreadCancel = new CancellationTokenSource();
Task.Run(() => DataTask(_processingThreadCancel.Token));
}
