On 28 Sep 2022, at 19:40, Neal Gompa <ngompa13@gmail.com> wrote:

On Wed, Sep 28, 2022 at 7:48 PM Simon Farnsworth via devel
<devel@lists.fedoraproject.org> wrote:

On 28 Sep 2022, at 14:27, Neal Gompa <ngompa13@gmail.com> wrote:

On Wed, Sep 28, 2022 at 3:22 PM Ian Pilcher <arequipeno@gmail.com> 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