[Libva] Opengl surface to VaSurface

[Oliver Seitz]

>> Planned scheme: h.264 stream ->vaapi decoder ->  VaSurface ->  OpenGl Surface
>> ->  Opengl postprocessing ->  VaSurface ->  vaapi encoder ->  h.264 stream.
>
> There is work in progress for this use case, through EGL extensions.

Using this scheme, would this add a possibility to adjust image contrast 
and brightness for VAAPI accelerated playback through OpenGL controls?

Greets,
Kiste