Aha, ok I see. My bad. So what is the difference from the user perspective provided that the back-end implementation works?
AFAIK it would mean that with the Galluim3D/Mesa based drivers and the open-source Intel and ATI drivers directly supporting VA-API and a sort of wrapper/layer/translator for fglrx and nvidia you would just need to implement VA-API support in your player to GPU enabled decoding on all (major) cards.
Maybe someone who has a fancy tag like AMD Linux Guy or X.org Dev could confirm is this might be a/the possible outcome.
Well unoffical specs for XvBA do not really help to get direct support. The wrapper is no bad idea, comes a bit late maybe, because vdpau implementations are already done and getting better so this wrapper is primary for fglrx. Using vdpau it is possible to have osd and subtitles displayed already (with mplayer+xinelib). I guess lots of work is done in the finetuning, so when the Intel implementaion works just a tiny bit differnet to the wrapper things can get worse than direct support. Did somebody try it with ati?