Sunday, April 27, 2008

AMD : Bridgman clarifies "textured video" support

Another update from the #radeonhd channel. AMD's John Bridgman went over the state of textured video support across the drivers.
bridgman: coolix/Goga: for GPUs before R5xx there was enough video processing in the overlay block that you could support xv without using the 3d engine. Starting with R520 and RS6xx we removed the overlay video proc and do the colour space conversion and scaling using shaders. Adding textured video support will be more work for 6xx than for 5xx since the texture blocks don't support YUV format directly, so we'll need to do some more shader coding.

We did the initial 3xx-5xx textured video work in the -ati driver rather than radeonhd
since the DRI support was still being added to radeonhd, but the DRI work is making good progress so we should be able to do 6xx texvid support directly in radeonhd rather than developing in radeon and porting across to radeonhd like we did for 5xx.

dennisb: in the ati driver when I tried textured xv I got a lot of tearing lines (just a comment about it, not a complain really)

bridgman: the texvid code is pretty new so it's still being worked on. It's probably weakest on 5xx right now. The other remaining issue is that I don't think there is any mechanism to sync the video playback up to monitor vsync right now so you probably would see tearing when there is a lot of motion on the screen

bridgman: dennisb: if you are still seeing problems with recent git code pls let us know, since we'll be using essentially the same code in radeonhd as well. I haven't checked to see if there is a bugzilla ticket open. WIsh I had a better way to differentiate between "really bad tearing" (something we should fix) vs "mild tearing" (which will need vsync support and more buffering to address)

yes... I did edit the text lines some more to make it easier to read.
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