81 is three weeks old & is the first release that will have Linux video gpu support enabled by default. source: https://9to5linux.com/firefox-81-enters-beta-gpu-acceleratio...
note that this is firefox at large. no idea whether the pi supports the standard va-api acceleration interface or what other potential blockers the pi has.
Whether that translates to actual video decoding acceleration on any platform depends on availability of libva backends. And performance (or power consumption) may still suck, if you can't use the frame buffers directly for output to some HW overlay.
Linux kernel APIs are fairly straightforward, and easy to use, if you use them directly from some simple app. But making it work across all the abstractions from browser, to compositor, to display server, via ffmpeg, via libva, etc. is not easy at all.
Question-- how exactly does one check that gpu-acceleration is on in FF? I'm running nightly on a NUC with Intel Iris GPU and it seems to be faster than LTS from Debian Bullseye, but I'd like to be sure...
More info here:
https://wiki.archlinux.org/index.php/firefox#Hardware_video_...
Maybe firefox whitelisted only h264 for hw decode?
[Child 78229: Main Thread]: D/PlatformDecoderModule VA-API FFmpeg is disabled by platform [Child 78229: Main Thread]: D/PlatformDecoderModule Sandbox decoder rejects requested type
Same in Nightly 82.0b9.
This is on a Dell XPS 13 amd64 with Mesa Intel® UHD Graphics (ICL GT1) running Ubuntu running Wayland.
I haven't tested my RPI4 yet. But if Intel graphics aren't a "supported platform," it's difficult to imagine any graphics under Linux that would be.
Didn't test trying to force-enable because we're talking about supported platforms.