libGDX/Android: How to loop background music without the dreaded gap?

Question

I'm using libGDX and face the problem that background music does not flawlessly loop on various Android devices (Nexus 7 running Lollipop for example). Whenever the track loops (i.e. jumps from the end to the start) a clearly noticeable gap is hearable. Now I wonder how the background music can be played in a loop without the disturbing gap?

I've already tried various approaches like:

• Ensuring the number of Samples in the track are an exact multiple of the tracks sample rate (as mentioned somewhere here on SO).
• Various audio formats like .ogg, .m4a, .mp3 and .wav (.ogg seems to be the solution of choice here at SO, but unfortunately it does not work in my case).
• Used Androids MediaPlayer with setLooping(true) instead of libGDX Music class.

• Used Androids MediaPlayer.setNextMediaPlayer(). The code looks like the following, and it plays the two tracks without a gap in between, but unfortunately, as soon as the second MediaPlayer finishes, the first does not start again!

      /* initialization */
      afd = context.getAssets().openFd(filename);
      firstBackgroundMusic.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
      firstBackgroundMusic.prepare();
      firstBackgroundMusic.setOnCompletionListener(this);
  
      secondBackgroundMusic.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
      secondBackgroundMusic.prepare();
      secondBackgroundMusic.setOnCompletionListener(this);
  
      firstBackgroundMusic.setNextMediaPlayer(secondBackgroundMusic);
      secondBackgroundMusic.setNextMediaPlayer(firstBackgroundMusic);
  
      firstBackgroundMusic.start();
  
  
  
      @Override
      public void onCompletion(MediaPlayer mp) {
          mp.stop();
          try {
              mp.prepare();
          } catch (IOException e) { e.printStackTrace(); }
      }
  

Any ideas what's wrong with the code snippet?

Answer 1

Just for the records: It tuned out to be unsolvable. At the end, we looped the background music various times inside the file. This way the gap appears less frequently. It's no real solution to the problem, but the best workaround we could find.