[MPlayer-dev-eng] [PATCH] reduce flashing on resize with VDPAU

[Dan Oscarsson]

On 2009-03-18 at 10:34 +0100 Reimar Döffinger wrote:

> > I can do my patch for just the vsync handling, but if there is a better
> > one I can try it. Which patches are you thinking of?
> 
> You can try attached patch. There are some issues though: I only tested
> with the blit engine, which behaves a bit weirdly, it should be possible
> to disable it, and it should be possible to adjust the number of output
> surfaces used.
> It might also be nicer to allow skipping in the draw_image part for
> cases where the GPU usage is the issue, but that has higher jitter.

I have tested in the difficult case when fps is same (nearly) as vsyncs
per second.

Using 4 output surfaces I get, after a while, frames being display
nearly 2 vsyncs late (in my case running at 23,976hz, 70-80 ms).
Using 3 surfaces it works like my patch (which is expected as it is more
or less done in the same way), giving a delay up to about 40 ms.

Your patch, just like mine, will drop many frames when mplayer calls
flip_page just when the vsync occurs.

> 
> > Note: the moment you allow several frames to be queued, audio easily
> > gets slightly out of sync without mplayer noticing it as frames may be
> > shown long after they were queued by flip_page.
> 
> Which some people may still prefer over frame-dropping.

Well, I prefer to not have any frame dropping and audio in sync.
Currently, if I have no frame dropping, I can easily get audio out of
sync by 100-200 ms or even more which makes the movie unwatchable.
The way mplayer syncs video to audio does not work well when fps is same
as vsyncs per second.