Sorry for the delay, I have build a dozen or so dependencies but then got stuck on libvalhalla.
From what I remember it fails to see the ffmpeg libraries.
I think the problem is that the ffmpeg package is quite old. Because it's rather unstandard I haven't got around packaging it yet, plus I had some stuff to take care of around the house.
So if anyone wants to give this one a try, tell me and I'll upload all the dependencies that I have build so far.
I'll get back to it as soon as I'll have some free time on my hands.