Berlin university seems to switch off the server running the atrpms repo. That is not official but after 10 days down it is easy to think it.
I have read some post in the CentOS list about this issue. In some answers, people recommends to choose alternative repos. That is a crap. The recommendations are pointed to choose ffmpeg v0.10.x or similar.... oh come on! the last ffmpeg version today is 2.8.x ... is that serious?
In our infrastructure ffmpeg 2.2.x is valid for us, it is the atrmps version. So I have cloned, in the ENETRES Centos 6.x repo, the necessary packages (from atrmps) to install ffmpeg 2.2.x and mediainfo tool (with dependencies).
It you are in troubles, you can use our repo for that version install (note1: remember we have strong dependency from EPEL repo, note2: these packages are not official and they don't have any support).
Good luck! :)