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[directfb-dev] Re: Seeing "tearing" using mplayer dfbmga
On Mon, 2002-12-09 at 18:25, Denis Oliver Kropp wrote: > Quoting Antonino Daplas (email@example.com): > > Some possibilites that can be considered: > > > > 1. Direct rendering implies writing to the video memory directly, which > > is not just slow, but can be cached. In some hardware, you actually need > > to do a read of the video memory (even just one byte, just to flush the > > contents) to ensure that everything is in sync. Especially true with > > MTRR. MTRR accumulates all those little writes and after a certain > > threshhold, burst write everything at once. > > Writing to the video memory is even faster than writing to system > memory on my P3 800 system with a G400 AGP. However, reading from video > takes ten times as long as reading from system memory. > Also I don't think that caching is the cause as the amount of data is > fairly big. > You're right, I just mentioned it because I just cleaned up rivafb (for linux-2.5) using an old riva128 pci card. And everything is slow, had some weird problems such as disappearing cursors and what-not :-). > > 4. Which is why we really need an AGP surface in DirectFB for things > > like video :) > > Yes, we really need that, but I'm too lazy to refactor the surface manager > stuff for such an extension. > Attempted it once too, but it will need someone who knows the ins and outs of DirectFB :-) Tony -- Info: To unsubscribe send a mail to firstname.lastname@example.org with "unsubscribe directfb-dev" as subject.