VLCJ playmedia() stops play after about 1 second of playback

Question

I've used the code from Caprica's old Tutorial2B.java to play the whole file:

public class Tutorial2B {

private final EmbeddedMediaPlayerComponent mediaPlayerComponent;

public static void main(final String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
        @Override
        public void run() {
            new Tutorial2B(args);
        }
    });
}

private Tutorial2B(String[] args) {
    JFrame frame = new JFrame("vlcj Tutorial");

    mediaPlayerComponent = new EmbeddedMediaPlayerComponent();

    frame.setContentPane(mediaPlayerComponent);

    frame.setLocation(100, 100);
    frame.setSize(1050, 600);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);

    mediaPlayerComponent.getMediaPlayer().playMedia("/home/me/sample.MP3");
    }
}

However, I cannot get the following code to play my audio file for more than a split second:

public class Tutorial2B {

private final AudioMediaPlayerComponent mediaPlayerComponent;

public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
   @Override
   public void run() {
      new Tutorial2B();
      }
   });
}

private Tutorial2B() {
    mediaPlayerComponent = new AudioMediaPlayerComponent();
    MediaPlayer  mediaPlayer = mediaPlayerComponent.getMediaPlayer();
    mediaPlayer.playMedia("/home/me/sample.mp3")
}

Any clues as to why this isn't working?

current code Dec 21st:

public class Tutorial2B {

static AudioMediaPlayerComponent mediaPlayerComponent = null;

public static void main(String[] args) {

    mediaPlayerComponent = new AudioMediaPlayerComponent();
    mediaPlayerComponent.getMediaPlayer().playMedia("/home/sss.mp3");

    }
}

Answer 1

The reason the tutorial application works and your modified audio player application doesn't is because of garbage collection.

In both examples, when you do SwingUtilities.invokeLater() and the run() method terminates, your entire application goes out of scope and becomes eligible for garbage collection. You are not keeping a reference to the application class.

In the case of the example application this OK because creating a Swing UI (the JFrame) is enough to prevent the application from being garbage collected.

In the case of your modified application, there is no Swing UI created and consequently nothing that will prevent the application being garbage collected. In fact, in this case your application will simply exit.

I am actually surprised you say removing the use of SwingUtilities fixes your problem as there is still nothing I can see that will keep your application from being garbage collected. When I see an application like this, I have seen on Linux it will exit just about immediately, and on Windows it will exit some unpredictable time later after a garbage collection has been executed.

The more robust solution is to use something like join() on the current thread to prevent the application from exiting, or somehow otherwise keep a reference to your application class pinned, and then for example to wait for a media player event of "finished" or "error" before terminating your application.

In "real" applications this sort of thing is generally not a concern since there are other things keeping your application from being garbage collected (like a UI, or some other application framework).

Answer 2

Removed the call SwingUtilities. Plays fine now.