Affected versions

• 84.0a1(2020-10-21); 83.0b2;

Affected platforms

• macOS 11.0, macOS 10.15;

Steps to reproduce

1. Launch Firefox on 2 instances;
2. Connect with 1 valid Facebook account in each;
3. Perform a call between the 2;
4. From any call window enable PIP;
5. Close the PIP window;

Expected result

• call is working ok;

Actual result

• audio-video feed stop;

Regression range

• will check and provide one asap;

Additional notes

• S3 as suggested severity since the call needs to be re-set in order to work;
• calls between Windows10 - macOS have the same issue only when closing the PIP on macOS.

ni? myself to have a look

Hello! I have managed to find the regression range of this issue with the STR provided in the description. The calls have been made between MacOS 10.15 and Windows 10.
Here is the regression pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=9f3fcb6752b4e36779e395abef8362f0b0d14e7b&tochange=cad2c16785936bd362cc7f19ad521d2a1db1bb79

(In reply to Negritas Sergiu from comment #2)

Here is the regression pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=9f3fcb6752b4e36779e395abef8362f0b0d14e7b&tochange=cad2c16785936bd362cc7f19ad521d2a1db1bb79

Well that includes bug 1653496 which enabled PiP for MediaStream playback in the first place, so not the real regressor. This is something latent I guess, probably timing related since it's mac only.

Simpler STR (reproduces on both mac and linux):
1 Load https://mozilla.github.io/webrtc-landing/gum_test.html
2 Click Camera
3 Approve permission prompt, if any
4 Once video is live, right click video element and click picture-in-picture
5 Close the pip window with the X in the top right corner

Expected: video is still live
Actual: video is frozen

Doing this for Camera+Microphone shows that audio playback freezes too.

https://pernos.co/debug/tzq_Rigjp9gQrVsaMekarA/index.html

So PictureInPictureChild calls pause() on the media element when closing the pip-window. See my notes in the notebook in the pernosco recording.

Pausing on close is one of the things that doesn't translate well from playback (youtube et al) to realtime (video conf). Mike, FYI.

Hey Chris, perhaps you could look at this? I think we'd want to change the behaviour of this message here: https://searchfox.org/mozilla-central/rev/96e2c6e14998f38e419850d55d8a3d32a3fc244a/toolkit/components/pictureinpicture/content/player.js#298

Instead of pausing unilaterally, let's pass an object along with it to say that we want to pause specifically because the user has closed the player window. In the receiving side of that message, we should check to see if the associated video has a non-null srcObject property, and if so, skip pausing.

Note that by spec srcObject is not necessarily a MediaStream. It happens to be in Firefox at the moment, but expect that to change at some point. For non-MediaStream srcObjects we should maintain current behavior.

Thanks, pehrsons!

https://hg.mozilla.org/mozilla-central/rev/775b72d2e46453999d85384dadca776c89189c21

The patch landed in nightly and beta is affected.
:jack1391, is this bug important enough to require an uplift?
If not please set status_beta to wontfix.

For more information, please visit auto_nag documentation.

Comment on attachment 9187019 [details]
Bug 1672623 - Closing PiP window pauses the cloned video element for video conferences. r?mconley,gijs

Beta/Release Uplift Approval Request

• User impact if declined: When using PiP with video calling/conferencing tools, closing the PiP window breaks things in ways users can likely not recover from without ending and re-establishing the call
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: Yes
• If yes, steps to reproduce: See comment #1 / comment 4
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): We're making an exception to pausing-when-closing PiP just for video call situations. The code change is pretty small and has good test coverage.
• String changes made/needed: nope

Verified as fixed on Firefox Nightly 85.0a1 (2020-11-24) on Windows 10 x64, Ubuntu 20.04 and on MacOS 10.15 following the steps from comment #1 / comment 4.

Comment on attachment 9187019 [details]
Bug 1672623 - Closing PiP window pauses the cloned video element for video conferences. r?mconley,gijs

approved for 84.0b5

https://hg.mozilla.org/releases/mozilla-beta/rev/170db6291411

Verified as fixed on Firefox 84.0b5 on Windows 10 x64, Ubuntu 20.04 and on MacOS 10.15 following the steps from comment 1 / comment 4.