public Windows.Foundation.IAsyncOperationWithProgress <uint, uint> WriteAsync(IBuffer buffer)
{
return(System.Runtime.InteropServices.WindowsRuntime.AsyncInfo.Run <uint, uint>((token, progress) =>
{
return Task.Run(() =>
{
// If it's the first WriteAsync in the stream
// the buffer should contains the WAV Header
if ((internalStream.Size == 0) && (wavHeaderLength == 0))
{
WriteDataIndex = 0;
// Check header
byte[] array = buffer.ToArray();
wavHeaderLength = ParseAndGetWAVHeaderLength(array);
internalStream.WriteAsync(buffer).AsTask().Wait();
WriteDataIndex += buffer.Length;
progress.Report((uint)(buffer.Length));
return (uint)(buffer.Length);
}
else
{
if (internalStream.Position != internalStream.Size)
{
System.Diagnostics.Debug.WriteLine("Warning WriteAsync: " + internalStream.Position.ToString() + "/" + internalStream.Size.ToString());
}
ulong index = internalStream.Size;
uint byteToWrite = buffer.Length;
// System.Diagnostics.Debug.WriteLine("WriteAsync: " + buffer.Length.ToString() + " at position: " + internalStream.Position);
internalStream.WriteAsync(buffer.ToArray(0, (int)byteToWrite).AsBuffer()).AsTask().Wait();
WriteDataIndex += buffer.Length;
var byteArray = buffer.ToArray();
if (byteArray.Length >= 2)
{
var amplitude = Decode(byteArray).Select(Math.Abs).Average(x => x);
if (AudioLevel != null)
{
this.AudioLevel(this, amplitude);
}
// Currently the level is too low
if (thresholdDurationInBytes > 0)
{
if (audioStream == null)
{
if (internalStream.Size > thresholdDurationInBytes)
{
var readStream = internalStream.GetInputStreamAt(internalStream.Size - thresholdDurationInBytes);
byte[] readBuffer = new byte[thresholdDurationInBytes];
readStream.ReadAsync(readBuffer.AsBuffer(), (uint)thresholdDurationInBytes, InputStreamOptions.None).AsTask().Wait();
var level = Decode(readBuffer).Select(Math.Abs).Average(x => x);
if (level > thresholdLevel)
{
System.Diagnostics.Debug.WriteLine("Audio Level sufficient to start recording");
thresholdStart = WriteDataIndex - thresholdDurationInBytes;
audioStream = SpeechToTextAudioStream.Create(nChannels, nSamplesPerSec, nAvgBytesPerSec, nBlockAlign, wBitsPerSample, thresholdStart);
var headerBuffer = CreateWAVHeaderBuffer(0);
if ((audioStream != null) && (headerBuffer != null))
{
audioStream.WriteAsync(headerBuffer.AsBuffer()).AsTask().Wait();
audioStream.WriteAsync(readBuffer.AsBuffer()).AsTask().Wait();
}
}
}
}
else
{
audioStream.WriteAsync(buffer.ToArray(0, (int)byteToWrite).AsBuffer()).AsTask().Wait();
var readStream = internalStream.GetInputStreamAt(internalStream.Size - thresholdDurationInBytes);
byte[] readBuffer = new byte[thresholdDurationInBytes];
readStream.ReadAsync(readBuffer.AsBuffer(), (uint)thresholdDurationInBytes, InputStreamOptions.None).AsTask().Wait();
var level = Decode(readBuffer).Select(Math.Abs).Average(x => x);
if (level < thresholdLevel)
{
System.Diagnostics.Debug.WriteLine("Audio Level lower enough to stop recording");
thresholdEnd = WriteDataIndex;
audioStream.Seek(0);
var headerBuffer = CreateWAVHeaderBuffer((uint)(thresholdEnd - thresholdStart));
if (headerBuffer != null)
{
audioStream.WriteAsync(headerBuffer.AsBuffer()).AsTask().Wait();
}
if (audioQueue != null)
{
audioStream.endIndex = thresholdEnd;
audioQueue.Enqueue(audioStream);
}
if (BufferReady != null)
{
this.BufferReady(this);
if (audioStream != null)
{
audioStream = null;
}
thresholdStart = 0;
thresholdEnd = 0;
}
}
}
}
}
if (maxSize > 0)
{
// check maxSize
if ((internalStream.Size > maxSize) && (audioStream == null))
{
lock (maxSizeLock)
{
byte[] headerBuffer = null;
if (wavHeaderLength > 0)
{
// WAV header present
headerBuffer = new byte[wavHeaderLength];
inputStream = internalStream.GetInputStreamAt(0);
inputStream.ReadAsync(headerBuffer.AsBuffer(), (uint)wavHeaderLength, InputStreamOptions.None).AsTask().Wait();
}
seekOffset += (internalStream.Size - wavHeaderLength);
internalStream.Dispose();
inputStream.Dispose();
internalStream = new Windows.Storage.Streams.InMemoryRandomAccessStream();
if (headerBuffer != null)
{
internalStream.WriteAsync(headerBuffer.AsBuffer()).AsTask().Wait();
}
inputStream = internalStream.GetInputStreamAt(0);
}
}
}
if (internalStream.Position == internalStream.Size)
{
WriteDataIndex += buffer.Length;
}
progress.Report((uint)buffer.Length);
return (uint)buffer.Length;
}
});
}));
}