Comment # 4 on bug 1002441 from Wolfgang Bauer

(In reply to Episteme PROMENEUR from comment #3)
> i installed bad,ugly,origin from packman repo
> 
> problem still there

Again, can you play them with dragon player?

You may need gstreamer-plugins-bad-orig-addon,
gstreamer-plugins-ugly-orig-addon, and gstreamer-plugins-libav too.

And again, ffmpeg (and *all* libav* packages) should come from Packman as well.

I just tried and it works fine here with both phonon4qt5-backend-gstreamer and
phonon4qt5-backend-vlc.