If you're thinking about using this, you might also consider Gordon (https://github.com/tobeytailor/gordon) or Smokescreen (https://github.com/cesmoak/smokescreen). Gordon's simpler -- very easy to follow code. Whereas Smokescreen, like Swiffy, offers support for audio and AS2. I integrated Gordon into my HTML5 game yesterday to render a walk cycle SWF and the framerate didn't drop. I'm going to do the same thing with Smokescreen next.