Re: Mesa in F37- vaapi support disabled for h264/h265/vc1

[Simon Farnsworth]

>  On 28 Sep 2022, at 19:40, Neal Gompa <ngompa13(a)gmail.com&gt;
> wrote:
>  
>  On Wed, Sep 28, 2022 at 7:48 PM Simon Farnsworth via devel
>  <devel(a)lists.fedoraproject.org <mailto:[e-mail]>>
> wrote:
> > 
> >> On 28 Sep 2022, at 14:27, Neal Gompa <ngompa13(a)gmail.com&gt; wrote:
> >> 
> >> On Wed, Sep 28, 2022 at 3:22 PM Ian Pilcher <arequipeno(a)gmail.com&gt; wrote:
> >>> 
> >>> On 9/28/22 03:50, Tommy Nguyen wrote:
> >>>> This change will only affect AMD, as the intel non-free drivers do not
> >>>> depend on the changes. It is also unclear how this would affect nvidia.
> >>>> There is barely any hardware video acceleration support for nouveau
> >>>> anyway, for which you would install the proprietary driver. Further, as
> >>>> NVIDIA does not expose a vaapi interface, you need to install third
> >>>> party packages to get it to work with Firefox. So AFAICT this will
> >>>> primarily (if not only) affect AMD users.
> >>> 
> >>> So only everybody who specifically purchased a discrete GPU that works
> >>> "out of the box" with Fedora?
> >> 
> >> Well, we don't ship any userspace software that provides the necessary
> >> support code to use those codecs anyway.
> >> 
> > Firefox was able to use VA-API on Intel (at least - I don’t have Radeon hardware to
> hand) to accelerate H.264 decode.
> > 
>  
>  Intel doesn't use Gallium (Mesa) for VA-API. You need a separate
>  driver package for it, which we currently don't ship and the version
>  being reviewed will not have these codecs enabled.
>   
To be clear - I wasn’t saying that Intel used Mesa for VA-API; I was saying that
with Mesa drivers and Radeon hardware, I would expect Firefox’s VA-API support to work as
well as it does for Intel, but I have not been able to test this.

> > And we ship gstreamer1-vaapi which lets any GStreamer using
> application (Totem, for example) use hardware acceleration.
>  
>  Hmm, I forgot about that. FFmpeg doesn't have it because ffmpeg does
>  stupid things when the codec is available but doesn't work. GStreamer
>  is probably more intelligent about failing over.
>   
GStreamer elements run code to determine what codecs are supported - the VA-API
elements use this to avoid claiming to support a codec unless it will work.

I’m not familiar with the current state of FFmpeg - in the dim and distant past, it relied
on data tables to determine what codecs a given plugin supported, rather than running code
(hence the VA-API plugins can’t claim no codec support when VA-API is unavailable).

— 
Simon Farnsworth