The only think to consider is that if bicubic filtering is enabled then these new attributes won't be available. Here's the latest I could find on turning bicubic off -- looks like it's controlled by *another* attribute :
"You can disable it on the fly using the XV_BICUBIC Xv attribute. You can use an app like xvattr to change Xv attributes."
Last I remember is that bicubic is enabled by default on 3xx-5xx hardware. I'm pretty sure about 5xx, less sure about 3xx-4xx.
yeah, XV_BICUBIC is only available on r3xx-r5xx. To disable it, run:
xvattr -a XV_BICUBIC -v 0 -p <port>
where <port> is the textured video port you want to disable bicubic on. You can see the ports with xvinfo or xvattr.
Can you really call Xv video acceleration? I don't think so.
You can't call it video *decode* acceleration (since it only covers the *render* portion of the playback stack) but as Zhick said Xv makes a huge difference in CPU utilization during video playback and can also improve video quality along the way (by doing processing which the CPU would not be able to handle).
And that's exactly why I think it's really irritating to call it "video acceleration", which nowadays is more or less synonymous with decode acceleration. I think I've never seen anyone call Xv "video acceleration" before.