1667814 - getDisplayMedia cursor capture not working under Fedora Linux

Status: NEW

(Core :: WebRTC: Audio/Video, defect, P3)

Description

[heavy]

User Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:81.0) Gecko/20100101 Firefox/81.0

Steps to reproduce:

navigator.mediaDevices.getDisplayMedia({
    audio: false,
    video: {
        cursor: "always"
    }
}).then(...)

Actual results:

The mouse cursor was not captured along with the screen capture in the resulting video stream.

Expected results:

The mouse cursor should have been captured in the resulting video stream.

This was tested under Fedora Linux when screen sharing from Linux. When I shared from Firefox on a Mac the mouse cursor was captured. I also tested under Chrome on Linux and that also worked as expected.

Comment 1

[Paul Adenot (:padenot)]

Thanks for the report. Would you mind attaching here a copy of about:support? "Copy raw data to clipboard", putting this into a file, and attaching it here would be best. Thanks!

This works for me on Ubuntu 20.04.1 LTS, running with X11.

Comment 2

[heavy]

Attachment: support-data.txt

Well, if I had a guess, I'd suppose it has something to do with using Wayland.

I was running the browser in "safe mode" for this example.

Comment 3

[Paul Adenot (:padenot)]

Yeah that would be plausible. Work is currently happening for Wayland / Pipewire, etc., I don't know of the current status or bugs. Dan, do you know ?

Comment 4

[Dan Minor [:dminor]]

Cursor capture is working for me in Nightly without Wayland, so I suspect this is Wayland related.

Wayland support in WebRTC is blocked by our build system, there are some details here: https://bugzilla.mozilla.org/show_bug.cgi?id=1430775. Once we update libwebrtc, we can fix up our build system to not rely on code generation based upon gn files, which should unblock us from better Wayland support.

In the mean time, distributions are patching their Firefox builds to support Wayland. It might make sense to report this bug to your distribution as well, in case they are able to fix it in their builds. Sorry!