Clarifications about Gstreamer

Solution 1:

Gstreamer 1.0 is installed by default on 14.04 (See the desktop image manifest)

But you need to install additional plugins to get VA-API support.

Install the following package in a Terminal:

sudo apt-get install gstreamer1.0-vaapi

For VDPAU, check this answer: How to enable VDPAU on GStreamer?