VA-API VP9 decoding not working (video is black and won't play)

[Eloston]

Version: 73.0.3683.103-1.buster1

VA-API VP9 decoding does not seem to be working under X11. A black area appears where the video should be shown, and it won't play. No errors are printed out to stdout/stderr.

Here's a test site: https://base-n.de/webm/VP9%20Sample.html
YouTube videos also have the same problem.

The workaround is to disable chrome://flags/#disable-accelerated-video-decode so that software rendering is used.

Wayland works, but I don't think hardware acceleration is being used because it logs an error from vaapi_wrapper.cc that vaInitialize failed: unknown libva error.

Hardware: Intel HD 620 and UHD 630

@riyad Do you have this issue in your Ubuntu Cosmic build?

@xsmile Does VA-API acceleration work for you under Arch Linux?

[xsmile]

No issues here with an Intel HD 4000, however it doesn't accelerate VP9 decoding.

I found similar reports for Arch Linux and Fedora:
https://aur.archlinux.org/packages/chromium-vaapi/
https://bugzilla.redhat.com/show_bug.cgi?id=1694651

It might be better to reintroduce the old behavior and keep VA-API available, but disabled by default.

[riyad]

Tested on Ubuntu 18.10 (cosmic) with Intel HD 620 integrated graphics.

• In a Gnome-Wayland session both videos work.
• In a Gnome X11 session the VP8 video works, but the VP9 video is broken as described above. Disabling the "Hardware-accelerated video decode" flag indeed makes it work again.

[Eloston]

@riyad Thanks for testing.

@xsmile

It might be better to reintroduce the old behavior and keep VA-API available, but disabled by default.

Could you clarify what you mean by "old behavior"?

[xsmile]

@Eloston The current patch [1] enables hardware acceleration by default, whereas the previous variant [2] - which isn't compatible to the current Chromium version anymore - requires users to explicitly enable several flags first.

1: https://salsa.debian.org/chromium-team/chromium/blob/master/debian/patches/fixes/vaapi.patch
2: https://chromium-review.googlesource.com/c/chromium/src/+/532294

[Eloston]

@xsmile I see. In that case, we can just set chrome://flags/#disable-accelerated-video-decode to be enabled disabled by default. Once VP9 decoding is fixed, we can disable enable it by default again.

[riyad]

I just tested a prebuild of mine on Ubuntu 19.04 (disco):

• In a Gnome-Wayland session both videos work with both settings.
• In a Gnome X11 session disabling the "Hardware-accelerated video decode" breaks the VP9 video. When enabled both videos play fine. 🙃

[Eloston]

I decided not to implement a fix for this issue in 74 since a good solution would be more involved than I thought it would be, and I'm hoping Debian will come up with a fix for this. Instead, please just set chrome://flags/#disable-accelerated-video-decode to Disabled manually.