/// <summary>
        /// Starts recording.
        /// </summary>
        /// <param name="sender">RecordImage</param>
        /// <param name="e">Event arguments</param>
        private void Record_Tap(object sender, RoutedEventArgs e)
        {
            if (m_isRecording)
            {
                RecordImage.Source = new BitmapImage(new Uri("/Assets/record.png", UriKind.Relative));
                m_d3dInterop.StopRecordingOrPlayback();
                m_recordingTime = DateTime.Now - m_recordingStartTime;
            }
            else
            {
                RecordImage.Source   = new BitmapImage(new Uri("/Assets/record_active.png", UriKind.Relative));
                m_recordingStartTime = DateTime.Now;
                m_d3dInterop.StartRecording();
            }

            PlayImage.IsHitTestVisible = m_isRecording;
            PlayImage.Opacity          = m_isRecording ? 1.0 : 0.5;
            m_isRecording = !m_isRecording;
        }