code: public void setMediaPlayer(final GVRVideoSceneObjectPlayer mediaPlayer) {
          if (mVideo == null) {
              getGVRContext().runOnGlThread(new Runnable() {
                  @Override
                  public void run() {
                      mVideo.setMediaPlayer(mediaPlayer);
                  }});
          } else {
              mVideo.setMediaPlayer(mediaPlayer);
          }
      }
docs: Sets the current {@link MediaPlayer}
  
  @param mediaPlayer
  An Android {@link MediaPlayer}