Worked for me. Thanks!
Works for me
I tried to run the command susggested by Olivier and the program output is: MEncoder...
On the RPMFusion bug report for this, someone found out the program eventually starts...
mplayer version: mplayer-1.1-16.20131125svn.fc20.x86_64
So, it seems the Fedora package in RPMFusion is affected as well, see https://bugzilla.rpmfusion.org/show_bug.cgi?id=3124...