[mythtv] YV12 problem

[Jean-Yves Avenard]

On Thu, 13 Dec 2018 at 04:49, David Engel <david at istwok.net> wrote:

> Have you looked at videoout_openglvaapi.cpp yet?  What Mark described
> mostly(*) made sense and seems like the way forward.  Something very
> similar to that seems like the way to go.  Configure vaapi to decode
> the frames into opengl memory.  If hardware deiterlacing is chosen, it
> gets done during decoding and simply display the resulting progressive
> frames.  If opengl deinterlacing is chosen, don't deinterlace during
> decoding and do so in opengl if needed.  The only loss is the ability
> to use the software deinterlacers which really isn't a loss in my
> opinion.
>
> (*)I don't think Mark fully grasped that the deinterlacing could be
> done automatically during decoding.  Either that or he knows about
> some other opengl relationship to vaapi of which I'm unaware.

No, it's just that vaapi provided no deinterlacing interface at the
time Mark wrote the code, it came much later.

vaapi only provided Bob deinterlacing originally, and it wasn't done
during the decoding but on display.

In any case, if you are using vaapi or any other HW decoding
interface, you certainly don't want to use any software deinterlacer,
the cost for readbacks is way too great.