/** starts the audio if this is an audio stream. */
public void startAudio(MediaDevice mediaDevice) {
if( mediaStream instanceof AudioMediaStream ) {
AudioMediaStream ams = ((AudioMediaStream) mediaStream);
ams.setDevice(mediaDevice);
ams.start();
}
}
/** returns a visual component for this stream or null if this is not a video stream. */
public JPanel getVisualComponent() {