title: FFMPEG Fade in and Fade out for Overlay
body: <p>I'm trying to add Overlay-Pictures to my video via FFMPEG (on Android). For know I managed to display the Image between a certain time span. But now, additionally, I want to add a fade in and fade out animation.
  Here is what I have so far:</p>
  
  <pre><code>ArrayList&lt;String&gt; cmd = new ArrayList&lt;String&gt;(); cmd.add("-i"); 
  cmd.add("video.mp4");
  cmd.add("-i");
  cmd.add("../image.png");
  cmd.add("-filter_complex");
  cmd.add("overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2:enable='between(n,1,12)'"); 
  cmd.add("out.mp4");
  </code></pre>
  
  <p>How do I need to add the Fade in and Fade Out options.</p>