[Xine-vdpau] software equalizer (Gamma correction) not working with vdpau

[Christophe Thommeret]

Le vendredi 26 mars 2010 13:51:21, Christian Neumair a écrit :
> 2010/3/24 Christophe Thommeret <hftom at free.fr>:
> > Le mercredi 24 mars 2010 18:10:38, Christian Neumair a écrit :
> >> Dear xine-vdpau developers,
> >>
> >> using the Ubuntu Karmic the-vdr-team svn build based on xine-vdpau svn
> >> revision 284, I was unable to get xine's software equalizer to work.
> >> (...)
> >>
> >> My use case involves vdr-sxfe which is based on xineliboutput, for
> >> applying Gamma correction for a presentation beamer that was not made
> >> for movies and TV. I'd also be happy if the xgamma setting was applied
> >> on the vdpau window, but this does not seem to be the case. Any ideas?
> >
> > This works here with xine-lib-1.2
> 
> Does that mean that the xgamma setting is applied to the xine vdpau
> window on your machine? Because in my case it isn't :(. What nvidia
> driver and xine build do you use exactly? vlc+ffmpeg-vaapi seems to
> respect the xgamma setting, though.

Yes, xgamma is applied to the vdpau window as well.
nvidia 195.36.15
hg xine-lib-1.2
Note that this is on the blit path, dunno if it works on overlay.

> I feel a bit dumb now, because I think one would have to understand
> the internals of X11, X11 gamma correction, vdpau and the entire Linux
> video hardware stack to understand how gamma correction works in
> detail [i.e. whether it is applied in hardware or software], and why
> it doesn't work for my vdpau xine. All I can say is that gamma
> correction of xv output seems to work for myself.

In the case of xine's post filters, the corrections are done in software, on 
the yuv planes. That's why it doesn't work with hardware decoding, since then 
yuv planes are stored in video mem; a solution would be to get yuv data back 
to sysmem, apply filters, then reload in videomem for display, but most of 
hardware decoding gain would be lost.

> > Note that the post filters won't work with hardware decoding, so if your
> > avi file contains mpeg1/2, vc1, or h264 video, no post filter!
> 
> Thanks for the comment, it looks like in my mplayer test, post
> filtering only worked because I did not use vdpau for decoding, but
> just the vdpau output display driver. mplayer probably is supposed to
> use a vaapi-patched ffmpeg for decoding, and something in my tool /
> lib chain seems to be seriously broken so that mplayer doesn't pick up
> the ffmpeg codec.
> 
> best regards,
>  Christian Neumair
> 

-- 
Christophe Thommeret