For providing hardware accelerated codec support there is the Codec Engine for modern Texas Instruments ARM platforms. "Codec Engine (CE) is a framework that enables applications to easily instantiate and work with XDM codecs and algorithms using a common API."
Exposing this TI accelerated interface is "libdce", which is an open-source library maintained by Texas Instruments, and is currently supported by a few multi-media sample applications like omapfbplay and gst-ducati.
However, setting up libdce & co isn't quite as easy as if looking to use VDPAU or VA-API under Linux. Details on this project for those wanting to investigate more about the codec possibilities can find useful details from the GitHub project page.
There's also more information on the codec engine itself from the Texas Instruments Wiki.
I'll have more ARM Linux desktop benchmarking news when returning to the office on Thursday. There's also a NVIDIA TEGRA-2 system waiting to be tested too.