title: ffmpeg fix not divisible by 2 (401x480) using -filter_complex
body: <p>I need to fix not divisible by 2 using <code>-filter_complex</code> parameter.</p>
  
  <p>Most solutions to fix divisable by 2 use <code>-vf</code> but I cant use both in the same command.</p>
  
  <pre><code>os.system("/tmp/ffmpeg -f lavfi -i color=black -i /tmp/2.gif -filter_complex  '[0][1]scale2ref[bg][gif];[bg]setsar=1[bg];[bg][gif]overlay=shortest=1'  /tmp/outBlack2.mp4")
  </code></pre>