private void _startCaptureInternal(GraphicsCaptureItem item)
{
_captureVideoFilePath = System.IO.Path.Combine(_captureFolder.Path, "ouput.wmv");
_mediaEncoder.OpenVideoWriter(_captureVideoFilePath, item.Size.Width, item.Size.Height);
_framePool = Direct3D11CaptureFramePool.Create(CanvasDevice.GetSharedDevice(), DirectXPixelFormat.B8G8R8A8UIntNormalized, 1, item.Size);
_seesion = _framePool.CreateCaptureSession(item);
_seesion.StartCapture();
_capturing = true;
QueryPerformanceCounter(out long counter);
_startTime = TimeSpan.FromTicks(counter);
Task.Run(_onFrameArraved);
}