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

[Reimar Döffinger]

On Sun, Dec 08, 2013 at 03:49:12PM +0100, wm4 wrote:
> On Sun, 8 Dec 2013 14:52:43 +0100
> Reimar Döffinger <Reimar.Doeffinger at gmx.de> wrote:
> 
> > My best explanation is that this is a NVidia driver bug, there is no
> > reason the decoder should care about aspect changes.
> 
> Of what nature would this bug be? I can see no problems on mpeg2 vdpau
> decoding with nvidia drivers on non-mplayer. Is it triggered by
> libavcodec threading? (I think I heard something about threading.)

The driver claims that there is a size mismatch even though no size
anywhere changed, only aspect.
More specifically, reinitializing the decoder _with exactly identical
settings_ fixes a VDP_STATUS_INVALID_SIZE error, which doesn't make any
sense.
You probably see no issues anywhere because everyone else uses the same
overkill approach of doing a complete reinitialization for no good
reason on an aspect change.
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 do not consider that relevant though, since as said doing a full
reinit is idiotic and wasteful anyway.