WebRTC H265 / HEVC should now be supported on firefox

[fxzzi]

Which version are you using?

v1.14.0

Which operating system are you using?

Linux amd64 standard

Describe how to replicate the issue

1. start the server
2. publish with obs, using and sort of h265 / hevc encoder
3. read with a modern firefox version like 142
4. observe that the stream doesn't load with error "codec not supported by client"
5. navigate to https://lf-tk-sg.ibytedtos.com/obj/tcs-client-sg/resources/video_demo_hevc.html and see that hevc in fact works fine.

Server logs

No response

Network dump

No response

[bp0]

Are you trying to view it in the browser with WebRTC or HLS?
Assuming WebRTC, Firefox does not support H265 via WebRTC.
From the (new?) MediaMTX docs, You can check what codecs your browser can publish or read with WebRTC by using this tool.

edit:
A little extra, related, info, WebRTC with H264 is only supported in Firefox if media.webrtc.hw.h264.enabled is manually set to true in about:config.
Firefox likes VP9 and AV1 for WebRTC.

[fxzzi]

Thanks, I'd love to do VP9 or AV1 however my GPU doesn't support either of them for encoding with nvenc.

[aler9]

I checked and yes, it seems that Firefox now supports decoding H265 when there's a hardware decoder available. For now, things are limited to MSE / WebCodecs, therefore HLS works without issues. WebRTC probably still needs some flag.

[fxzzi]

thanks for your reply. Yeah I guess webrtc h265 isn't supported just yet.