I reinstalled my machine (formerly running Ubuntu trusty), and rygel no longer admits to the existence of mp4 files. I have restarted it twice and it will serve any file other than mp4, which are all missing when listed over upnp/dlna. The version on trusty (and earlier) had no such problem. In possibly related news, it throws the following error multiple times : libmediaart-CRITICAL **: media_art_get_file: assertion 'artist != NULL || title != NULL' failed Andrew Gallagher