public AudioCapture()
{
SampleFormat = ALFormat.Mono16;
BufferLength = 10;
SampleRate = 44100;
source = Observable.Create <Mat>((observer, cancellationToken) =>
{
return(Task.Factory.StartNew(() =>
{
var sampleRate = SampleRate;
var bufferLength = BufferLength;
var sampleFormat = SampleFormat;
var channelCount = SampleFormat == ALFormat.Stereo16 ? 2 : 1;
var bufferSize = (int)Math.Ceiling(sampleRate * bufferLength / 1000);
var readBuffer = sampleFormat == ALFormat.Stereo16 ? new Mat(bufferSize, channelCount, Depth.S16, 1) : null;
var captureInterval = TimeSpan.FromMilliseconds((int)(bufferLength / 2 + 0.5));
var captureBufferSize = bufferSize * 4;
lock (captureLock)
{
using (var capture = new OpenTK.Audio.AudioCapture(DeviceName, sampleRate, sampleFormat, captureBufferSize))
using (var captureSignal = new ManualResetEvent(false))
{
capture.Start();
while (!cancellationToken.IsCancellationRequested)
{
while (capture.AvailableSamples >= bufferSize)
{
var buffer = new Mat(channelCount, bufferSize, Depth.S16, 1);
if (readBuffer != null)
{
capture.ReadSamples(readBuffer.Data, bufferSize);
CV.Transpose(readBuffer, buffer);
}
else
{
capture.ReadSamples(buffer.Data, bufferSize);
}
observer.OnNext(buffer);
}
captureSignal.WaitOne(captureInterval);
}
capture.Stop();
}
}
},
cancellationToken,
TaskCreationOptions.LongRunning,
TaskScheduler.Default));
})
.PublishReconnectable()
.RefCount();
}
public void ReadSamples(int offset, int count, float[] buffer)
{
AssertNotDisposed();
if (count < 0)
{
throw new ArgumentOutOfRangeException("count", "count must be >= 0.");
}
if (offset < 0)
{
throw new ArgumentOutOfRangeException("offset");
}
if (offset + count > buffer.Length)
{
throw new ArgumentOutOfRangeException("count", "offset + count must be <= buffer.Length.");
}
count = Math.Min(count, (int)(TotalSamples - Position));
switch (NativeFormat)
{
case AudioFormat.Byte8:
{
var arr = new byte[count];
handle.ReadSamples(arr, count);
Parallel.For(0, arr.Length, (i) => buffer[offset + i] = (float)(arr[i] / (float)byte.MaxValue * 2) - 1);
break;
}
case AudioFormat.Short16:
{
var arr = new short[count];
handle.ReadSamples(arr, count);
Parallel.For(0, arr.Length, (i) => buffer[offset + i] = arr[i] / (float)short.MaxValue - 1);
break;
}
}
}
