When one firefox user joins to conference, screen sharing quality is bad

we have problems with screen sharing with firefox on our ADFC ( German National Cyclists Association) jitsi Meet.

When a meeting is only with chrome user, everything is okay. But if one user has a firefox, the quality is
instant down.

Version: Debian Bullseye:

ii  jitsi-meet            2.0.6826-1          all          WebRTC JavaScript video conferences
ii  jitsi-meet-prosody    1.0.5764-1          all          Prosody configuration for Jitsi Meet
ii  jitsi-meet-web        1.0.5764-1          all          WebRTC JavaScript video conferences
ii  jitsi-meet-web-config 1.0.5764-1          all          Configuration for web serving of Jitsi Meet
ii  jitsi-videobridge2    2.1-607-g153f7e4e-1 all          WebRTC compatible Selective Forwarding Unit (SFU)
ii  openjdk-11-jre-headless:amd64 11.0.14+9-1~deb11u1 amd64        OpenJDK Java runtime, using Hotspot JIT (headless)

This does not happen if we use https://meet.jitsi.si


  • config-js.txt (19.1 KB)
  • webrtc_internals_dump.txt (1.9 MB) WebRTC Dump from Google Chrome. Do not know how to read this. We made a meeting, share a screen, then at:
    • 9:57:02 a user with firefox join the meeting, the quality is bad
    • 9:57:30 the firefox user leaves the meeting, the quality is good again

Any help is appreciated.

Best Regards

if it works on meet.jit.si, how about making your share screen settings identical to the meet.jit.si’s ones ?

I think that the relevant settings

 // Desktop sharing
desktopSharing: 'ext',
chromeExtensionId: 'kglhbbefdnlheedjiejgomgmfplipfeb', 
 desktopSharingChromeMinExtVersion: '0.1',

    // Whether desktop sharing should be disabled on Firefox.
    desktopSharingFirefoxDisabled: false,
  videoQuality: {
        preferredCodec: "VP9",
        maxBitratesVideo: {
          VP8: {
            low: 200000,
            standard: 500000,
            high: 1500000
          VP9: {
            low: 100000,
            standard: 300000,
            high: 1200000

are identicily. Do you have a Idea what to change?

    // Optional desktop sharing frame rate options. Default value: min:5, max:5.
    desktopSharingFrameRate: {
         min: 15,
         max: 30

while meet.jit.si has default settings (it’s not present)

Okay, we found it. It was the Websocket, not the desktopSharingFrameRate