Can't install plugins to play h.264/mp3

Since I acquired a new computer I have been unable to play any MP3 or H.264 files. (expect in an external VLC installation)
Loading a H.264 video in totem or firefox instructs me to install gstreamer-plugins-bad-1.0.10-2.5.4.x86_64, gstreamer-plugins-bad-1.0.10-2.1.4.x86_64,
gstreamer-plugins-good-1.0.10-2.1.4.x86_64 and gstreamer-plugins-good-1.0.10-2.1.4.x86_64. Clicking accepts returns a generic error message that promises “more information is available in the detailed report,” but fails to provide any such report, though the YAST logs note “No installation candidate for missing plugins found.” Attempting to install these plugins (albeit different versions) from packman by downloading them manually returns a similar error. Nor can I install ffmpeg or fluendo plugins.

You’ll need to install the Restricted Codecs from Packman, take a peek here;

When it asks to switch Vendor to Packman, please choose to do so - you can use the red “One Click” installer on the page.

That does help, I can now play mp3s in Clementine and h.264 videos in Firefox. Totem still won’t play h.264, but I can just use VLC.