Well, further reading the question, I found sudo add-apt-repository ppa:mc3man/trusty-media sudo apt-get update sudo apt-get install ffmpeg gstreamer0.10-ffmpeg
and that made arista working again (well, restarting arista was needed).
Well, further reading the question, I found trusty- media 10-ffmpeg
sudo add-apt-repository ppa:mc3man/
sudo apt-get update
sudo apt-get install ffmpeg gstreamer0.
and that made arista working again (well, restarting arista was needed).