Tearing problem at bigger overlay sizes
Christiaan van Dijk
dvbmail at xs4all.nl
Wed Jan 14 12:27:30 PST 2009
>>> take 2s to draw ...
>>> I must have missed something, it looks way too slow.
>> Well for one, 1920 * 1080 is about two million pixels, not two
>> billion. :)
> Ahem *blushes* ... so we're down to .002s to draw an HD screen, 1/10th
> of a frame at 50Hz. I don't know what's the duration of a vblank with an
> LCD using reduced blanking, but it should fit in.
in the mean time I did some more experiments with trying waiting for V
blanking and rendering in multiple segments but whatever I'm trying the
tearing is still present :-(. Not sure how to continue with this, if the
numbers in the wiki are right a full screen should be rendered in
1.24ms, the vertical blanking in my setup is 0.8ms so here is a problem,
already assuming maximum rendering speed. Best results upto now are
waiting for a V blank by stalling the processor and using 24Hz refresh
rate for more rendering time.
How about the AVIVO part?? This should offer specific functions for
these kind of operations, any support or details on this?? Or can the
system handle a shadow frame?? Render the frame off-screen and switch
screen in the V-blanking, this should be fast enough.
More information about the xorg-driver-ati