Bug 312281 – Audio issues observed when joining Cisco Meeting Server meetings using Safari

• Component: WebRTC
• Status: RESOLVED FIXED

[Sheela]

Users joining Cisco Meeting Server meetings via Safari browser experience audio problems that impacts the reliability of audio communication.

Steps to reproduce:
1. Join a Cisco Meeting Server meeting from Safari
2. Stay connected for several minutes
3. Observe intermittent audio disruptions

Safari version - 26.3.1
macOS - Tahoe 26.3.1

[Radar WebKit Bug Importer]

<rdar://problem/175260977>

[youenn fablet]

*** Bug 312908 has been marked as a duplicate of this bug. ***

[youenn fablet]

@Sheela, do you have repro steps that we could use?
Is it reproducible using Webex Safari client ?
If you can share a sysdiagnose privately ([e-mail]), with the time where the issue reproduced, that would be useful too.

[youenn fablet]

Looking at the sysdiagnose in https://bugs.webkit.org/attachment.cgi?id=478546 comment 8, I see that we constantly add/remove the same audio source via IncomingAudioMediaStreamTrackRendererUnit::addSource/removeSource.
This is quite unexpected and might trigger some audio issues.

@Sheela, can you characterise the audio issues? Is it that audio gets choppy?

[youenn fablet]

I tried reproducing with Webex but could not so far. I did not see all the IncomingAudioMediaStreamTrackRendererUnit logging that I saw in the sysdiagnose.

[youenn fablet]

I can reproduce the IncomingAudioMediaStreamTrackRendererUnit logging when changing of audio speakers.
In the sysdiagnose I mentioned, it is as if the page is sometimes trying several times per second to change of audio speaker.

[Sheela]

(In reply to youenn fablet from comment #4)
> Looking at the sysdiagnose in
> https://bugs.webkit.org/attachment.cgi?id=478546 comment 8, I see that we
> constantly add/remove the same audio source via
> IncomingAudioMediaStreamTrackRendererUnit::addSource/removeSource.
> This is quite unexpected and might trigger some audio issues.
> 
> @Sheela, can you characterise the audio issues? Is it that audio gets choppy?

Yes, the audio is choppy and disruptive, making it difficult to hear clearly.

[Sheela]

Bumping up the priority to P1, as this issue is being observed by VIPs and executives from multiple customers who are escalating it to Cisco Executives. Therefore, we need a quick fix.

[youenn fablet]

@Sheela, can you provide more info on how to reproduce and/or provide a sysdiagnose?

[youenn fablet]

IncomingAudioMediaStreamTrackRendererUnit logs can happen when adding/removing tracks of the rendered audio.
I'll work on a fix to prevent this case.
@Sheela, it would be good if you can send me another sysdiagnose that converts this is the root cause.

[youenn fablet]

Pull request: https://github.com/WebKit/WebKit/pull/65094

[EWS]

Committed 313415@main (0ea009b4f3b9): <https://commits.webkit.org/313415@main>

Reviewed commits have been landed. Closing PR #65094 and removing active labels.