public InputStream(Device deviceToOwn)
{
_self = GCHandle.Alloc(this);
_device = deviceToOwn;
_stream = InStream.Create(_device);
try
{
if (_stream.IsInvalid)
{
throw new InvalidOp("Stream allocation error");
}
if (_device.Layouts.Length == 0)
{
throw new InvalidOp("No channel layout");
}
// Calculate the best latency.
// TODO: Should we use the target frame rate instead of 1/60?
var bestLatency = Math.Max(1.0 / 60, _device.SoftwareLatencyMin);
// Stream properties
_stream.Format = Format.Float32LE;
_stream.Layout = _device.Layouts[0];
_stream.SoftwareLatency = bestLatency;
_stream.ReadCallback = _readCallback;
_stream.OverflowCallback = _overflowCallback;
_stream.ErrorCallback = _errorCallback;
_stream.UserData = GCHandle.ToIntPtr(_self);
var err = _stream.Open();
if (err != Error.None)
{
throw new InvalidOp($"Stream initialization error ({err})");
}
// We want the buffers to meet the following requirements:
// - Doesn't overflow if the main thread pauses for 4 frames.
// - Doesn't overflow if the callback is invoked 4 times a frame.
var latency = Math.Max(_stream.SoftwareLatency, bestLatency);
var bufferSize = CalculateBufferSize((float)(latency * 4));
// Ring/window buffer allocation
_ring = new RingBuffer(bufferSize);
_window = new byte[bufferSize];
// Start streaming.
_stream.Start();
}
catch
{
// Dispose the resources on an exception.
_stream.Dispose();
_device.Dispose();
_stream = null;
_device = null;
throw;
}
}
