[eluser]Colin Williams[/eluser]
[url="http://ffmpeg.mplayerhq.hu/ffmpeg-doc.html#SEC5"]It runs on the server.[/url] You run it from the command line.
Code:
exec('ffmpeg -y -i /path/to/avi/12.avi -acodec mp3 -ar 22050 -f flv /path/to/flv/14.flv')
Don't know it in and out, but it's sort of the defacto standard for video sites, so far as I know.
It would be nice if someone wrote a CI Lib for ffmpeg, exposing its most common features. Actually, I'd imagine there's already a PHP class out there for it, so it might already be done.