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.

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!

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.

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

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.

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

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)?

(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.

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.

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.