Am 09.02.2018 um 21:35 schrieb Philipp Kerling:
Hi,
resurrecting this thread again since there's been some progress on the
Kodi side.
For the EGL part, see <https://github.com/01org/libva/pull/125>
and <https://lists.freedesktop.org/archives/mesa-dev/2017-October/171246.html>.
We recently started testing vaExportSurfaceHandle support, so we will
have this covered soon.
I have been testing with mpv and ffmpeg; any thoughts from the
Kodi point of view would be most welcome.
It generally works quite well, but we still have the unresolved
vaSyncSurface problem.
To recap: vaExportSurfaceHandle requires calling vaSyncSurface to make
sure that the decode is actually finished and the buffer is usable
before rendering the frame. However, vaSyncSurface was largely
unimplemented on mesa back then and it was unclear how to proceed with
regard to decode (VAAPI)/present (EGL+GL) synchronization.
So on to the question: Is this still the case, or has there been
progress on implementing vaSyncSurface in mesa? In either case, do we
need that support or does this syncing work implicitly somehow on AMD?
I've noticed that mpv does not seem to call vaSyncSurface, although it
technically should.
Actually the mpv approach is correct.
Calling vaSyncSurface is unnecessary and undesired for AMD hardware
because it moves synchronization to the CPU while it should happen on
the GPU and/or GPU scheduler.
E.g. our 3D pipeline can wait for hardware video decoding to finish
before starting the rendering. We even have some implementations which
allow the 3D pipeline to start when only the first halve of the picture
is decoded etc..
If we don't do this the 3D pipeline runs dry between frame decoding
which leads to problems with power management.
We should probably add a flag or bit or feature or something like this
to note that the application explicitly should NOT call vaSyncSurface
before exporting the surface.
Regards,
Christian.
Best regards,
Philipp
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/mesa-dev
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/mesa-dev
