private void OnDestroy()
 {
     if (instance == this)
     {
         instance = null;
     }
 }
    private void Awake()
    {
        if (instance != null)
        {
            Debug.LogError("Cannot create two instances of CamStreamManager.");
            return;
        }

        instance = this;
        VideoCapture.CreateAync(OnVideoCaptureInstanceCreated);
    }