vlc: Setting brightness

[Chris Worley]

Shane Harper wrote:
> There's some code for setting the brightness and contrast in the XVideo
> plugin (see the vout_Create function in plugins/x11/vout_xvideo.c). It's
> commented out in the source available from the VideoLAN site. Just uncomment
> it and the function it calls (XVideoSetAttribute). I find on my system that
> the useful range for the brightness value is 0.4 to 0.6.
> 
> It'd be good if you can come up with some way to set the brightness which
> will work with all the possible video output modules.

In the xvideo plugin code, there's a comment:

 "The brightness and contrast values should be read from environment"

It looks like it sets, rather than gets, the environment:

  XVideoSetAttribute( p_vout, "XV_BRIGHTNESS", 0.5 );

So, xv might have an easy work around, but, I think I'm screwed (I can't
use xv).  I've twiddled with palettes and colors anywhere I could find
them in the sdl and yuv plugins, and I can't effect the brightness (and
the folks who know this code don't give hints).

Chris