[MPlayer-users] VDPAU errors, flickering black video display on aspect change in MPEG2 TS

[Reimar Döffinger]

On Sun, Dec 08, 2013 at 04:22:48PM +0100, wm4 wrote:
> What might be slightly inefficient with my code is that it doesn't try
> to create a h264 decoder with less than maximum reference frames, since
> that isn't possible with the new vdpau libavcodec API.

Actually, huh? MPlayer uses the new API, and it can do it...

> > The only thing related to threading is that the VPDAU decoder will
> > see the aspect change many frames before the aspect actually changes
> > in terms of displayed video, and this desync would cause us issues
> > if we'd try to do a full decoder reinit on aspect change.
> 
> I don't see this with MT enabled either...

I don't see how you could not see it.
The VDPAU decode function is called during slice decode, which with
n threads multithreading will happen n frames before a frame with the
new aspect is actually returned.
If you're using FFmpeg multithreading I see no way you couldn't see
that the frames with the new aspect are decoded long before you can
in any way see the new aspect from your application.