Screen sharing doesn't work properly with Firefox 80

[ovari]

Description:

Steps to reproduce:

1. Open Firefox
2. Open LibreOffice Impress presentation
3. Menu Bar → Slide Show → Start from First Slide F5
4. Alt+Tab to switch to Firefox, open a room on Jitsi Meet and share the screen Presenting: …
5. When the presentation slides are changed, the other person with Firefox 80.0 (64-bit) only sees one slide, the slides do not change.

Expected behavior:

Screen share should work with Firefox.

Actual behavior:

Screen share does not show slide changes.

Server information:

• Jitsi Meet version: Jitsi Meet
• Operating System: 5th September 2020

Client information:

• Screen share program: LibreOffice 7.0.1.2 Linux (64-bit) (deb)
• Browser / app version: Firefox 80.0 (64-bit)
• Operating System: Linux Mint 20 Cinnamon

Additional information:

• All the participants in the Jitsi Meet Room were hidden, i.e. their video was turned off. Does this help to reproduce?
• Is this a bug introduced with the updated Jitsi Meet program?
• Is this a feature missing in Firefox 80 which the updated Jitsi Meet program requires? 100% support for Firefox (and other non-Chrome browsers) #4758
• Also didn't work when we shared a screen from a different program.
• Worked when Chrome was used by the presenter and the view was using Firefox. However, the sound was not good for the Firefox viewers when their microphones were muted. When the viewer unmuted their microphones, then the sound from the presenter (on Chrome) was fine.

Thank you

[damencho]

I believe there is nothing we can do for this issue, as this is entirely on the browser side. Search their bugzilla for a similar report and report it there.
Does it work with Firefox 79 or any other version?

[ovari]

Yes, Jitsi Meet worked with Firefox 79 and lower when we last used Jitsi Meet.

Since the last time we used Jitsi Meet:

• Firefox updated to 80.0
• Jitsi Meet now:
  a) has the Settings → More → Enable pre meeting screen
  b) no longer has the Tile view when You are the only one in the meeting

With Chrome, there was a delay of about 5 seconds from when the slide was changed by the presenter to the change being seen by the viewer.

[ovari]

Search their bugzilla for a similar report and report it there.

https://bugzilla.mozilla.org/show_bug.cgi?id=1663286

[saghul]

* Jitsi Meet now:
  a) has the Settings → More → Enable pre meeting screen
  b) no longer has the `Tile view` when `You are the only one in the meeting`

This is not related to screen-sharing.

[ovari]

Bug https://bugzilla.mozilla.org/show_bug.cgi?id=1663286 has also been confirmed on Windows 10 with Firefox Release 80.0 (64-bit) and Firefox Nightly 82.0a1 (2020-09-10) (64-bit). Thank you

[ovari]

Tried again today with 6 people (including us) in a Jitsi Meet room. They couldn't see our screen share. We were using Linux Mint 20 Cinnamon 64-bit with Firefox 80.0.1 64-bit. The Jitsi Meet room in our Firefox browser showed the screen share.

A person using Firefox 32-bit on Windows 7 (32-bit) could only see the screen share once we stopped sharing the screen. It showed them the screen which was shared after we stopped screen sharing!?

There was a person on our local area network (Linux Mint 19.3 Cinnamon 64-bit with Firefox 80.0.1 64-bit) that also couldn't see the screen share. Perhaps Firefox no longer works when there a someone in the Jitsi Meet room on the local area network?

https://bugzilla.mozilla.org/show_bug.cgi?id=1663286#c20

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[awlx]

Firefox 84.0.2 seems not to fix this issue as it happened again on https://meet.ffmuc.net ... we had to remove the following stanza to make it work again:

#4758 (comment)

Edit:// Ok seems not to fix it

[awlx]

Ok, I tried to reproduce it and on Firefox 84 it immediately fails with 78 it's working just fine. Here are the screenshots. Everytime I just share the screen from one window and have a look with 5 others.

working FF78:

Not working ff84.0.2:

As you can see the screensharing window appears but no video is transmitted

What is even more interesting if a Chrome user joins this session ... Screensharing magically starts to work for some of the Firefox users.

But not for the newly joined Chrome user:

And when the Chrome user starts to screenshare ... it is seen by everyone.

Also when the Firefox user stops to screenshare, everyone who received the picture sees a freeze of the last frame for ever.

When I start screensharing on Firefox the following shows in the browser console:

[awlx]

It seems the disableRTX Patch was missing on our plattform and now it works ...
jitsi/lib-jitsi-meet@0cffc06

Even tho Firefox says it's resolved:
https://bugzilla.mozilla.org/show_bug.cgi?id=1668028

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[pierreozoux]

I think it will be improved/fix by #7369 (comment)

[saghul]

Oops, looks like we forgot to close this one.