Hey everyone,

I'm running KDE Plasma Wayland with an RTX 3060 Laptop GPU and I'm trying to get hardware video decoding working in browsers.

What works:

• vainfo succeeds and reports VA-API NVDEC driver [direct backend]

• libva-nvidia-driver is installed

• mpv successfully uses NVDEC hardware decoding

• Firefox is running under Wayland (MOZ_ENABLE_WAYLAND=1)

• WebRender is enabled

Installed packages:

nvidia-open 610.43.02-2
nvidia-utils 610.43.02-2
libva 2.23.0-1
libva-nvidia-driver 0.0.17-1
ffmpeg 8.1.1-2

However, both Firefox and Chromium refuse to use hardware video decoding.

Firefox about:support shows:

HARDWARE_VIDEO_DECODING:
FEATURE_FAILURE_VIDEO_DECODING_TEST_FAILED

and under codec support:

H264: Supported, Unsupported
VP9: Supported, Unsupported
AV1: Supported, Unsupported

Firefox logging (firefox --MOZ_LOG="PlatformDecoderModule:5") contains:

Hw codec disabled by gfxVars for AV_CODEC_ID_AV1
Hw codec disabled by gfxVars for AV_CODEC_ID_VP9
Hw codec disabled by gfxVars for AV_CODEC_ID_VP8
Hw codec disabled by gfxVars for AV_CODEC_ID_HEVC
Hw codec disabled by gfxVars for AV_CODEC_ID_H264

vainfo reports the NVIDIA VAAPI driver correctly:

Driver version: VA-API NVDEC driver [direct backend]

Since mpv is able to use NVDEC without any issues, but both Firefox and Chromium fail to use hardware video decoding, I'm not sure where the problem is. As vainfo succeeds and hardware decoding works correctly in mpv, I would have expected browser hardware decoding to work as well.

I'm not sure what else to check at this point, so I'd appreciate any suggestions.