[MPlayer-users] vsync not working

[Vladimir Mosgalin]

On Mon, 3 Nov 2003, D Richard Felker III wrote:

DRFI>> DRFI>Yes, video overlay only works on the _first_ head. It's a
DRFI>> DRFI>limitation of the hardware. The other head will use the video
DRFI>> DRFI>blitter for xv, which _will_ tear, and there's nothing you can do
DRFI>> DRFI>about it. So switch the primary head to the one you'll be watching
DRFI>> 
DRFI>> Can you please explain, what exactly 'video blitter' means? It still
DRFI>> does yuv conversion and scaling in hardware?
DRFI>
DRFI>nvidia driver provides 2 xv devices: one overlay, and one which
DRFI>just does scaling and yuv->rgb conversion directly into the
DRFI>framebuffer.  The latter sucks because it will necessarily tear.

How this works in hardware? Nvidia cards have two scalers? How come the
first one can scale only one image, and the second can process multiple
images?

Also, my friend has riva tnt2, he uses windows. When he chooses in his
player 'offscreen yuv' (that's how that video blitter is called in
windows), the quality significantly increases - image becomes much less
blurry.
The default overlay can be compared with fast bilinear scaler, later -
with quality bilinear or bicubic, but the difference between them is
more than between bilinear and bicubic ones, it's highly noticable. In
addition to better quality, he also gets ability to play multiple videos
and take screenshots.

-- 

Vladimir