Apps that make use of mutagen such as quodlibet currently do not support Ogg Opus audio on Fedora. The fix would be easy: mutagen >= 1.21 is needed (1.24 is the latest release and it seems to work fine). For more information, see https://code.google.com/p/quodlibet/issues/detail?id=1012
*** This bug has been marked as a duplicate of bug 1048817 ***