Audio quality degrades as call goes on

I’ve been trying out meet.jit.si, I’d really like to migrate to a FOSS videocalling solution.

Sadly there’s a problem with my audio. From my end the calls seem to work fine but people I talk to always complain about my audio getting distorted. It’s not a continuous problem apparently. It usually starts out fine and then gradually gets worse. Then it magically resolves itself occasionally.

I’ve asked someone to record a sample and I have to say it’s a dealbreaker. I would like to share the recording but the upload button complains that new users can’t upload files.

I need some help troubleshooting this issue. How do I figure out why this is happening? Should I look at Firefox settings, System Preferences’ Sound section didn’t seem to have anything interesting (I’m on macOS).

This is most likely noise suppression kicking in. JItsi probably detected some noisiness from your mic and then tried to regulate it. To confirm (or rule this out), you can try a meeting with noise suppression disabled by passing a URL param e.g.

https://meet.jit.si/YourMeetingName#config.disableNS=true

Maybe AGC too?

Neither of these seem to help. Though I’m not sure I’m managing to set them. When I add one of these to the URL and press enter, the page doesn’t reload or anything. Is there a way to check whether the change has taken effect?

I did find a checkbox for noise suppression in the settings menu though and I suspect it’s off by default?

You ned to add them to the URL before joining.

I added #config.disableAGC=true&config.disableNS=true to the URL, opened in a new tab. And it seemed to be working fine until I plugged in my USB DAC to use my headphones.

I’m not sure why changing the sound output method would affect the input audio though?

Bluetooth devices may switch the profile if they are not being used for input and output at the same time, for example.

Since we don’t really process the audio (all those toggles are knobs for the browser APIs) not sure what else you can do.

There was no Bluetooth involved. Was on internal speakers and plugged in the USB DAC.

Is there any other service I can test that uses the browser APIs in a similar way to see if the distortion reproduces?

The Bluetooth case was an example. I don’t know if a similar thing can happen with other types of devices.

Try with this sample: Select audio and video sources

The distortion, or at least similar distortion does show up when using that WebRTC sample. If I understand correctly this means the problem has nothing to do with Jitsi and everything with either WebRTC or Firefox, right?

Yep. The interaction between the browser and your device seems to create the problem.

Any advice for next troubleshooting steps would be welcome. Should I open an issue on the Firefox bug tracker?

Yeah I’d say that’s a logical next step.

I use to have distorted audio-calls with my last computer and now, with the new computer and gettiing it with Fedora preinstalled audio is not a problem; your sound-card doesn’t work with the OS you’ve chosen; replace the sound-card with one that does work with your computer’s operating system. That will fix your audio problem.

Unfortunately that’s not an option. There’s no discrete soundcard in the system and I can’t change the OS.

There is always an option! If you can’t find one yourself, take your computer to the shop and tell them that your soundcard doesn’t work.

Are you using Windows or a version of Linux?

No, I’m on macOS, it’s in the OP. So it’s really not that easy.

Go to a mac store and get them to install a new soundcard; how hard can that be? Tell them that your mic is muffled when people get your audio an the other end of a call?

Apple doesn’t do sound card upgrades. Kindly stop suggesting unhelpful steps that distract from the issue at hand.

Hardware issues aren’t as likely an explanation as software issues for an intermittent problem like this one.