title: mediaplayer getduration returns 0 only in my server files
body: <p>i'm trying to get the audio file duration from my server 
  using media player </p>
  
  <pre><code>MediaPlayer mp = new MediaPlayer();
      try {
          mp.reset();
          mp.setDataSource("link here");
          mp.prepare();
  
      }catch (IOException e){
          e.printStackTrace();
      }
  
  
      mp.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
          @Override
          public void onPrepared(MediaPlayer mediaPlayer) {
              Log.e("time",mp.getDuration()+" ..");
          }
      });
  </code></pre>
  
  <p>when i put my server file link , it always return 0 
  but when i use another link from the web it gives me the right duration </p>
  
  <p>do i need to do some configuration for that ? </p>