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ziltoid

Member

Registered: 2020-10-15

Posts: 26

[Solved] Firefox: problem enabling hardware video acceleration

Hello everyone

I wanted to lower cpu utilization (and heat production) while watching twitch/youtube streams, so I tried to enable the VA-API on firefox following the wiki Hardware video acceleration. Here is what I did:

1. I installed libva-mesa-driver and verified the output with vainfo:

vainfo: VA-API version: 1.9 (libva 2.9.1)
vainfo: Driver version: Mesa Gallium driver 20.2.1 for Radeon RX 570 Series (POLARIS10, DRM 3.39.0, 5.9.1-arch1-1, LLVM 10.0.1)
vainfo: Supported profile and entrypoints
      VAProfileMPEG2Simple            : VAEntrypointVLD
      VAProfileMPEG2Main              : VAEntrypointVLD
      VAProfileVC1Simple              : VAEntrypointVLD
      VAProfileVC1Main                : VAEntrypointVLD
      VAProfileVC1Advanced            : VAEntrypointVLD
      VAProfileH264ConstrainedBaseline: VAEntrypointVLD
      VAProfileH264ConstrainedBaseline: VAEntrypointEncSlice
      VAProfileH264Main               : VAEntrypointVLD
      VAProfileH264Main               : VAEntrypointEncSlice
      VAProfileH264High               : VAEntrypointVLD
      VAProfileH264High               : VAEntrypointEncSlice
      VAProfileHEVCMain               : VAEntrypointVLD
      VAProfileHEVCMain               : VAEntrypointEncSlice
      VAProfileHEVCMain10             : VAEntrypointVLD
      VAProfileJPEGBaseline           : VAEntrypointVLD
      VAProfileNone                   : VAEntrypointVideoProc

2. I configured the VA-API settings creating the file ~/.xprofile (there wasn't one before) with the environment variable

 LIBVA_DRIVER_NAME=radeonsi 

3. I tried to set the compositor as written in Enable WebRender compositor and here I found the first problem. In the firefox menu about:support > Graphics > Decision Log > WEBRENDER there are enabled two options which should be mutually exclusive:

• "available by user: Force enabled by pref"

• "opt-in by default: WebRender is an opt-in feature"

4. I finished the configuration setting the flags in about:config

• media.ffmpeg.vaapi.enabled = true

• media.ffvpx.enabled = false

To verify if VA is enabled I run in the terminal the command

MOZ_LOG="PlatformDecoderModule:5" MOZ_X11_EGL=1 firefox

but there is no output to read, though firefox starts and works normally, so I am not sure if the procedure was successful or not (given the problem in passage 3 I think not).

Any ideas to debug this mess?

P.S. I use KDE Plasma and Zsh

Last edited by ziltoid (2020-10-27 18:47:16)

xerxes_

Member

Registered: 2018-04-29

Posts: 676

Re: [Solved] Firefox: problem enabling hardware video acceleration

I think you should also enable in Firefox in about:config these options:

gfx.webrender.all - true
gfx.webrender.enabled - true
layers.acceleration.force-enabled - true

and restart Firefox, than see in about:support if it change what is displayed about WebRender.

ziltoid

Member

Registered: 2020-10-15

Posts: 26

Re: [Solved] Firefox: problem enabling hardware video acceleration

Hello xerxes_

I applied the changes you suggested (the last two options were set to false) and based on the temperatures I see while watching streams it probably works. Unfortunately I still cannot see the output of the command

MOZ_LOG="PlatformDecoderModule:5" MOZ_X11_EGL=1 firefox

and the Webrender section in about:support still have the two options present:

For now I thank you for the help because it probably solved the problem. Now I just have to understand how to have an output to check when starting FF.

xerxes_

Member

Registered: 2018-04-29

Posts: 676

Re: [Solved] Firefox: problem enabling hardware video acceleration

I don't know how to check the difference in output from Firefox in terminal, but in about:support > WebRender you have 'available by user: Force enabled by pref' and you should see the difference in speed between hardware acceleration on and off on some more demanding sites like google maps and some benchmarks like this and for sure while playing videos, especially hi res videos.

Last edited by xerxes_ (2020-10-27 16:41:24)

ziltoid

Member

Registered: 2020-10-15

Posts: 26

Re: [Solved] Firefox: problem enabling hardware video acceleration

Using twitch and youtube I can see that cpu temperatures are lower and using google maps I can see the gpu temperature increasing, so I'm happy with the result.

Thank you for help