title: How do I use single input generating several resolution streams and output ll-hls?
body: <p>I use gpac transform rtmp to ll-hls without transcode:</p>
  <pre><code>gpac -i 'rtmp://:1935/live/abc:gpac:rtmp_listen=1' reframer:rt=on -o http://:80/live.mpd:gpac:segdur=10:cdur=1:profile=live:dmode=dynamic:llhls=sf
  </code></pre>
  <p>Now I want to transcode rtmp into several streams and serve them by ll-hls. How can I do this by <code>gpac</code> or <code>Mp4Box</code>?</p>