Comment # 4 on bug 1204074 from Callum Farmer

(In reply to Wolfgang Rosenauer from comment #3)
> Firefox always selects the "latest" support libavcodec.
> If you have libavcodec59 it will be used. Firefox has no idea that the
> installed library does not support all codecs.
> The solution would be to install the "correct" libavcodec59 package (I've
> got the one from packman).
> 
> So this is either a bad dependency in Chromium or no bug (local repo setup).
> 
> Firefox recommends libavcodec-full >= 0.10.16 to fetch a useful libavcodec
> package if available.

Chromium gets these deps automatically as they are linked libraries. 

Do:
sudo zypper lr -P