/// <summary>
        /// Called when MainForm is closed.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void MainForm_FormClosed(object sender, FormClosedEventArgs e)
        {
            videoPlayer.Stop();

            // dispose dlib resources
            if (faceDetector != null)
            {
                faceDetector.Dispose();
                faceDetector = null;
            }
            if (shapePredictor != null)
            {
                shapePredictor.Dispose();
                shapePredictor = null;
            }
        }
 public void Dispose()
 {
     dnn.Dispose();
     predictor.Dispose();
     detector.Dispose();
 }