Media Player example cannot play any video on Ubuntu 14.04

The post says it all.
It seems the gstreamer plugins are not loaded properly so when playing any video it will say "no codec found for ...".
Tested with H.264 and XVid.

Even if all the gstreamer 0.10 packages are installed and players like VLC or mplayer works perfectly.

A complete log with GST_DEBUG=3 is here: http://pastebin.com/sBMCtnTP

I've already done some preliminary tests as discussed in my OP on the Qt Forums: http://qt-project.org/forums/viewthread/44757/