[Retr0id]

The short answer is, it's for an exploit. It involves some slightly less-well-trodden boxes, and adding specially crafted metadata to live-generated videos in real-time, which existing libraries couldn't help me with much (and I did spend some time fighting a few libraries, but couldn't make them do precisely what I wanted).

"Library" is perhaps an overstatement, it does the things I need and not much more.

[der_rod]

A hah, that sounds cool, looking forward to the writeup!