I can't play any video content.  

I keep getting errors about missing plugins. I installed the 3rd party codecs at install.

I am getting the following error

```
No packages with the requested plugins found

```

The requested plugins are:

```
GStreamer element ffmux_dvd
GStreamer element ffdeinterlace

```

When I look in Ubuntu Software centre all of the Gstreamer plugins appear to be installed and the only option is to remove them.