How do I install the ffmpeg that works with Serviio 1.5.2?

NAS: zyxel nsa325v2
I have followed the guide that installs Serviio on Zyxel nsa325.
And during that guide I installed:
install mz:lame-3.99.5-arm-1.txz
install uli:ffmpeg-1.2.1-arm-1.txz
But how do I install and update to the best working ffmpeg?
I tried to read about it in the serviio wiki but don't understand how to update the "mz" and "uli" packages?
I get "stream can't be played" error in Mediabrowser.
I have followed the guide that installs Serviio on Zyxel nsa325.
And during that guide I installed:
install mz:lame-3.99.5-arm-1.txz
install uli:ffmpeg-1.2.1-arm-1.txz
But how do I install and update to the best working ffmpeg?
I tried to read about it in the serviio wiki but don't understand how to update the "mz" and "uli" packages?
I get "stream can't be played" error in Mediabrowser.