Some people are really disappointed with VAAPI stuff and companion VDPAU that they say it is better to avoid them all together and stay on software side. Complaints say the implementation is fixed in hardware thus not flexible, and the drivers are really buggy and not maintained, so anything based on them is rather not qualitative or breaks badly. Some are obsolete already, since codecs change so often.
I'm not a codecs expert, just reading what others say about this when dealing with various implementations.
