public void StopPlaying()
        {
            if (playing == false)
            {
                return;
            }

            if (avPlayer != null)
            {
                avPlayer.Stop();
                avPlayer = null;
            }

            if (otherPlayer != null)
            {
                otherPlayer.Stop();
                otherPlayer = null;
            }

            if (this.perfCounter != null)
            {
                perfCounter.Dispose();
            }

            lock (this)
            {
                if (rtpSession != null)
                {
                    rtpSession.Dispose();
                    rtpSession = null;
                }

                playing = false;
            }
        }