
PhantomJS is an headless browser based on an embedded webkit, suitable for testing of web applications involving JavaScript usage where simpler tools do not cut it.
I have found a pretty helpful article for ffmpeg recompile: //fozzolog.fozzilinymoo.org/tech/2009/11/recompiling-ffmpeg-for-fedora-12-to-add-faac-support.html . However, it looks like the instructions were incomplete.