1724127 - Video and audio are not properly loading during first seconds in Facebook videocalls

Status: NEW

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

Description

[Jeronimo Torti (Please send NI request to Brindusa Tot)]

Attachment: 20210804_FB.mp4

Affected versions

• Firefox Release 90.0.2

Affected platforms

• Windows 10 (x64)
• Ubuntu 20 (x64)
• Windows 7 (x64)
• MacOS 11

Steps to reproduce:
. Join a call on https://www.facebook.com/ with 2 participants.
. Allow audio and camera to start videochat.
. Once the Videocall begins, audio & video are randomly delayed. It can take about 20-30 seconds to start working.

Expected Result:
Once the Videocall begins, audio&video work properly and flow without issues.

Actual Result:
Randomly, audio & video are not loading after 20-30 seconds. Sometimes only video is delayed.

This issue was reproducible on Win10 and Ubuntu20, using Firefox Release 90.0.2 (64bit) version. Please, refer to video for further details.

Comment 1

[Jim Mathies [:jimm]]

Jerónimo, could we ask that you help us diagnose this by taking the following steps -

1. open facebook and get ready to connect
2. open about:webrtc, save the page out
3. connect / reproduce
4. save about:webrtc out again

post both logs to this bug.

Thanks!

Comment 2

[Jeronimo Torti (Please send NI request to Brindusa Tot)]

Attachment: aboutWebrtc first log before bug.html

Comment 3

[Jeronimo Torti (Please send NI request to Brindusa Tot)]

Attachment: aboutWebrtc after bug.html

Comment 4

[Jeronimo Torti (Please send NI request to Brindusa Tot)]

Hi Jim,
Sorry for the delay, we could reproduce this issue between two users, both using Win10 and Firefox Release 90.0.2, and now I attach both logs from that call. Any other suggestion or help, please, let us know.

Regards,
Jerónimo.

Comment 5

[Clara Guerrero ( Need Info Brindusa Tot Please)]

HI Jim,
When testing this issue using release 93.0 (64-bit) and beta 94.0b2 I didn't experience this lag in the camera.
Best,
Clara

Comment 6

[Clara Guerrero ( Need Info Brindusa Tot Please)]

Hi Jim,
When testing 4 participants call, macOS 10.15 is displaying a black screen and it won't load properly at all. MacOS participant sees other participants black as well (the camera image is not loading) and no audio at all is heard.
Ubuntu and Windows are not experiencing this problem.

Comment 7

[Jim Mathies [:jimm]]

Jib, mind taking look at the logs here and see if you can spot something?

Comment 8

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

The about:webrtc dump from the original issue show all packets being lost, so this is definitely a networking issue:

Decoder: Avg. bitrate: 1.59 (1.12 SD)Avg. framerate: 0.00 (0.00 SD)
Local: 14:41:13 GMT-0300 (Argentina Standard Time) inbound-rtp SSRC: 433335276Received 56,770 packets (64780.71 Kb , 0.0 Kbps)Lost 56,770 packetsJitter 0.094

Encoder: Avg. bitrate: 2.35 (0.39 SD)Avg. framerate: 0.00 (0.00 SD)Dropped frames: 90
Local: 14:41:13 GMT-0300 (Argentina Standard Time) outbound-rtp SSRC: 28711403Sent 87,528 packets (99367.87 Kb, 0.0 Kbps)
Remote: 14:41:13 GMT-0300 (Argentina Standard Time) remote-inbound-rtp SSRC: 28711403Received 87,100 packets (96887.22 Kb)Lost 87,100 packetsJitter 0.018 RTT: 167 ms

But that was a while ago and we shipped a major WebRTC update in 95, so I would ask Jeronimo: are you still able to reproduce the original issue with the lastest Firefox (96)?

Comment 9

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

(In reply to Clara Guerrero from comment #6)

Hi Clara, comment 6 sounds different enough from comment 0, only affecting mac and audio/video never appears instead of being delayed. So I've opened a separate issue bug 1751247 to track it. I'll follow up there.

Comment 10

[Jeronimo Torti (Please send NI request to Brindusa Tot)]

Hi,
I was not able to reproduce this issue again on Release 97.0.1 (64-bit) and Nightly 99.0a1 (2022-02-18) (64-bit). Since I will be out of Mozilla, please consider assign this one to other collegue if another testing is needed.

Thanks.

Comment 11

[Ardelean Oana, Desktop Test Engineering [:oardelean]]

We can still reproduce this issue on Nightly 110.0a1 on Ubuntu 22. Sometimes one of the call participants has to disable and re-enable the camera for the video to appear. This only happens intermitently and we're not 100% sure if it's FF related or not, but I'll return with an update once I have more information.

Comment 12

[Daniel Bodea [:danibodea]]

A similar issue is still observed reproducing intermittently. When making a 4 person call, some of the participants' webcam streams or audio streams might not work unless they leave and re-enter the group call. This issue also occurs on other browsers, like Chrome.
We believe that the original issue is the same as the one in our observations, or at least related.

Comment 13

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

... This issue also occurs on other browsers, like Chrome.

Hi Daniel, are you saying this issue reproduces in Chrome? In that case it is unlikely to be a Firefox specific bug.

Comment 14

[Daniel Bodea [:danibodea]]

Yes, as far as I can tell, this issue or a similar one was observed in Chrome browser as well.
Considering the intermittent nature, and unclear reproduction, we can't determine whether it is a Fx issue or a Facebook one.
We believed we should report findings in this report for posterity.

Will information from about:webrtc page help determine the cause? A Performance Profile or any other specific information?
If yes, I'll make sure to include them the next time I encounter this issue. Thanks!

Comment 15

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

If it happens in Chrome as well then this is something Facebook needs to address. It stops being a webcompat issue.

This bug is too old and contains conflicting info (2 vs 4 participants, groups etc). If it only happens with 3+ participants, the chances of this being a browser bug is extremely low. WebRTC operates at a much lower level than that.

I recommend closing this issue as inactionable. If it can be reasonably reliably reproduced in simple two-way call, I suggest opening a fresh issue with narrow steps to reproduce, and a Firefox profile capturing the problem.

Comment 16

[Daniel Bodea [:danibodea]]

We've just retested this scenario for recurrent WebRTC testing: 4 person video call on Facebook, for the first time.

We've definitely encountered it again in Nightly v147.0a1:

• initially audio and video would not connect for at least 30-60s causing confusion in the call, each participant was forced to close the call and rejoin;
• the second time they joined tha call, each participant showed a considerable delay in either displaying the video streaming or audio streaming of other participants;
• eventually (after 30-60s), the call was connected and usable.

We were focused on determining whether this issue also occurs in Chrome:

• initially, each participant showed a considerable delay in either displaying the video streaming or audio streaming of other participants;
• SOME participants were forced close and rejoin the call so that their wencam streams can be seen by the other participants;
• eventually (after 30-60s), the call was connected and usable.

Note: We've discovered that this issue is more likely to occur and it is more obvious if the user used a fresh user account (fresh FL login).
We could attempt further investigation if clear instructions are provided.

Conclusion: Our testing results show that a similar issue is also reproducible in Chrome, but it is considerably less severe there.

Considering your recommandation to closing this issue as inactionable, feel free to address this report however you see fit. Thank you!