Jan Stary wrote (2025-01-11 16:12 CET): > > Yes, chromium has h264 enabled by default, (our) firefox does not. > > Toggle the mentioned about:config key on, and webex will work. > > Here is a h264 support test page: > > https://mozilla.github.io/webrtc-landing/pc_test_no_h264.html > > Setting media.webrtc.hw.h264.enabled to true > makes the above page report YES. > > But what does it actualy do? FF plays e.g. > https://www.youtube.com/watch?v=u5ph_r3btss > both with that setting "true" and "false" > > Also, why would you disable (or enable, for that matter) > one specific video format? > > "Play the video on this page" > "No I won't: it's H264"
This thread is about WebRTC, not general video playback. Try a webex test meeting: https://www.webex.com/test-meeting.html According to the WebRTC RFC, h264 support is mandatory: https://datatracker.ietf.org/doc/html/rfc7742#section-6.2 I tested jitsi, zoom, webex, ms teams, bbb, google meet. Only webex fails without h264 support. All others support other codecs, or prefer more modern codecs anyway (like av1, vp9). However h264 _is the fallback_ for most of those solutions, because it is the most widely supported codec. It is also common in the IoT area, where cheap hardware streams video via webrtc. And cheap hardware can encode h264, but not the other formats. For example the raspberry pi KVM solution: https://pikvm.org > > We spend quite some time to get the openh264 plugin to run when > > Johannes figured out that it's not needed and toggling > > "media.webrtc.hw.h264.enabled" to "true" is sufficient. > > Setting it to false is also sufficient, apparently. You didn't test webrtc. > > (Can someone test if media.webrtc.hw.h264.enabled works on a system > > without libva / hardware h264 decoding support?) [..snip..] > How do you tell if FF offloads the decoding > to the H264-capable HW? It doesn't. Landry explained it in <z3_moztwkruol...@phoenix.rhaalovely.net>. On AMD, you can use graphics/radeontop to see if the GPU is used. Best regards, Stefan
