[FFmpeg-devel] [PATCH] hwcontext_vaapi: Only accept a render node when deriving from DRM device

[Anton Khirnov]

Quoting Mark Thompson (2020-02-16 21:59:54)
> If we are given a non-render node, try to find the matching render node and
> fail if that isn't possible.
> 
> libva will not accept a non-render device which is not DRM master, because
> it requires legacy DRM authentication to succeed in that case:
> <https://github.com/intel/libva/blob/master/va/drm/va_drm.c#L68-L75>.  This
> is annoying for kmsgrab because in most recording situations DRM master is
> already held by something else (such as a windowing system), leading to
> device derivation not working and forcing the user to create the target
> VAAPI device separately.
> ---
> Fixes a longstanding annoyance with -vf hwmap=derive_device=vaapi.
> 
> (E.g. <http://ffmpeg.org/pipermail/ffmpeg-user/2020-February/046660.html>.)

Looks reasonable.

-- 
Anton Khirnov