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Comment by mattst88 | Hacker News Reader

> Firefox still has no support for hardware video decode on Linux.

That's not true at all. See:

https://www.omgubuntu.co.uk/2023/07/firefox-115-intel-gpu-vi... https://www.phoronix.com/news/Mozilla-Firefox-115 https://www.omglinux.com/firefox-hardware-acceleration-raspb...

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How can I confirm whether Firefox is actually using hardware decode for videos on my machine for a given codec? Is there a magic keyword I should search for within the about:support page, or is it recorded somewhere else? Mine shows for instance "VP9_HW_DECODE default available", does this means it's using hardware decode for VP9, or merely that it might be possible for my Firefox version?

We've put a dedicated section called Media in about:support, it has decoding capabilities and other things such as audio IO informations.

If you find that it is not accurate, e.g. by cross-checking via other means, please open a ticket at https://bugzilla.mozilla.org/enter_bug.cgi, component "Audio/Video".

> We've put a dedicated section called Media in about:support, it has decoding capabilities

I see, I hadn't found it when searching for the codec name because it only said something like "Information not available. Try again after playing a video." After opening a random YouTube video and refreshing about:support, it did show the hardware decoding information, and it was as I had expected given the hardware on this computer.

At least with AMD GPU, an easy way to do it is to check usage of VCN.

Something like this (assuming your GPU index is 0):

    watch -n 1 sudo cat /sys/kernel/debug/dri/0/amdgpu_pm_info

You should see there:

    VCN: Enabled

If GPU accelerated video is being played.

I think you might need to set this flag to true in Firefox's about:config (or it might be not needed anymore):

    media.ffmpeg.vaapi.enabled

On an Intel GPU, you can check the 'Video' percentage in `sudo intel_gpu_top` (from the igt-gpu-tools package) while playing a video.

Whilst Firefox may support hardware video decoding, Mesa since March 2022 disables patent encumbered codecs by default[1], and distributions such as Fedora and OpenSuse do not explicitly enable these patent encumbered codecs to avoid possible legal problems. Even Gentoo (built from source code by the user) requires the user to explicitly enable a USE flag (proprietary-codes) to use patent encumbered codecs.[2]

The thought process is that AMD, NVIDIA, Intel and the likes are not providing a patent license with their hardware.[3] They are instead just supplying part of an overall system that together with operating system kernel, display manager software, video player software, etc allows the decoding and encoding of patent encumbered video files. Open source software projects and distributions are concerned they'd be found to be infringing patents by enabling a complete solution out-of-the-box. Hence they put some hurdles in place so that a user has to go out of their way to separately piece together the various parts to form a complete system capable of encoding and decoding patent encumbered codecs.

edit: To clarify, if your Intel or AMD GPU/APU supports a patent-free codec such as AV1 (most GPUs/APUs available for sale?), Firefox on a standard Linux distribution will use hardware video decoding out of the box by default for the patent-free codec. The issue is really one of whether you're sourcing content from a provider that uses a good choice of codec like AV1. The good news is that patent trolls are doing a good job of pushing laggard content providers down this path.[4]

[1] https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15...

[2] https://github.com/gentoo/gentoo/commit/1265a159743d7f07185a...

[3] https://lists.fedoraproject.org/archives/list/devel@lists.fe...

[4] https://news.ycombinator.com/item?id=38249527

Which is of course a bullshit reason because Linux distributions don't ship the patented hardware decoders (because they are hardwared) so the user already has to assemble the complete system.

> a provider that uses a good choice of codec like AV1

Much more limited HW support and slow as molasses encoders. Not exactly a good choice for most.

I use the flatpak version of Firefox because my Linux machine is an immutable OS.

Hardware video decode is working for FF.

Not working for Chrome though, sadly.

My bad, that's what I get for commenting before bed. I meant to tack on an "on Nvidia" in there. AMD and Intel are well supported with VAAPI, but I've never managed to get any of the NV-to-VAAPI wrappers and shims working.

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