WASAPI音频捕获上的C＃NAudio FFT

Question

这是我到目前为止所拥有的：

private void capture()
    {
        var capture = new WasapiLoopbackCapture();
        capture.DataAvailable += (s, a) =>
        {
            if (stop)
            {
                capture.StopRecording();
            }
        };
        capture.RecordingStopped += (s, a) =>
        {
            capture.Dispose();
        };
        capture.StartRecording();
        while (capture.CaptureState != NAudio.CoreAudioApi.CaptureState.Stopped)
        {
            Thread.Sleep(500);
        }
    }

我想对WASAPI音频捕获进行FFT，然后获取某个频带的幅度。