Desktop sharing FPS override

Description

I’m trying to get 30fps screen sharing working (in an embedded Jitsi Meet conference, using the external api). I’m using the configOverwrite flag as specified in config.js. According to the API docs it should work, but the value is not taking effect.

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

I’ve reported about this issue before in the community forum.

Current behavior

The desktop sharing fps will always be 5, regardless of the values set for desktopSharingFrameRate. With the only exception: presenter mode (desktop sharing and then turning on the webcam). The desktop sharing feed is 30fps in this mode, but my webcam is in the frame. Turning off the webcam drops the fps back to 5, so this isn’t a workaround. Clearly Jitsi Meet is capable of sending a 30fps desktop sharing stream. Quite amazing. Would be great if it would respect the values set for desktopSharingFrameRate.

Expected Behavior

I’d expect it to apply the fps specified in desktopSharingFrameRate, since it’s a documented config setting.

Possible Solution

Properly implement the code handling the desktopSharingFrameRate key in configOverwrite. I can currently work around it by capturing my desktop using OBS Studio, and presenting it as a virtual webcam. That way I could get a 30fps, desktop only, stream through Jitsi Meet. But clearly this is not ideal, and Windows only. Alternatively, perhaps it would be an option to increase the default FPS from 5 to 30 as temporary fix.

Steps to reproduce

Start sharing the desktop in one tab, open the same conference in another tab. Just observe the FPS isn’t 30.

Or check the FPS on the receiving end with: document.getElementById("largeVideo").srcObject.getVideoTracks()[0].getSettings().frameRate.

Environment details

Google Chrome on MacOS.

[jallamsetty1]

I’ve got this issue on my own deployment: the screen sharing frame rate doesn’t go above 5fps when using Chrome. Config:

desktopSharingFrameRate: {
     min: 30,
     max: 30
}

Deployment: DigitalOcean droplet running Ubuntu 18.04.3 LTS, with jitsi-meet stable installed. Happy to help if you need any more information.

Please make sure that capScreenSharingBitrate flag is disabled in config.js.

[jallamsetty1]

Update: tried again today, and fps climbed up until about 15fps using Chrome. As a side note, I’ve noticed different behaviors in different browsers with respect to frame dimensions and rate.

The desktop track fps is dependent on available resources like cpu and bandwidth and Chrome will bump it up based on those values. I am closing this issue since it is resolved.