Subject: Re: [bug#77827] Video playback still fails with 4fd529d

From: Ian Eure <[email-masked]>
Date: Sat, 19 Apr 2025 11:17:19 -0700

Hi Julian, Jakob,

Julian Flake <[email-masked]> writes:

> Hi Ian,
>
> thank you for the latest patches. Unfortunately video playback 
> still
> does not work for me on 4fd529dce953572551e299c0c604a645f0cbeed0 
> /
> 137.0.2-1.

Yep, I pushed the patch even though it didn’t fully fix the issue. 
Are you using non-free video drivers?  I am, and my symptoms don’t 
match what Jakob mentioned: video playback doesn’t work at all for 
me, but Jakob said video playback works, but poorly.

Jakob, can you confirm your symptoms and whether you’re using 
non-free drivers or not?

In the mean time you can go into about:config and set 
media.hardware-video-decoding.enabled to false, then restart the 
browser.  This restores the 136.x status quo of video playback 
working, but without hardware acceleration.  I’ll do some testing, 
but will likely push a patch making this the default.

Hardware video decoding is an issue in Guix for *all* 
Firefox-derived browsers, has been for some time[2], and I think 
the issue has to be something with the underlying libraries on 
Guix, though I don’t know what it is.  I don’t see these issues on 
Debian.  If anyone has ideas or patches, I’d love to hear.

Thanks,
  -- Ian

[1]: 
https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/137
[2]: See #72265, this also affects mullvad, torbrowser, icecat, 
and Firefox in nonguix.