Muting audio no longer turns off audio capture.

[ara4n]

Steps to reproduce

1. Press the mute button
2. See that the webapp is still capturing audio - e.g. on macOS/iOS:
   
3. Worry whether the mute button is actually working or not.
4. I /think/ we used to stop capturing audio while muted, to be more reassuring?

This is fairly low priority, but am flagging it more because it's slightly surprising me.

Outcome

What did you expect?

Audio should not be captured when you are muted.

What happened instead?

App keeps capturing audio despite being muted.

Operating system

macOS

Browser information

Chrome 127

URL for webapp

call.element.io

Will you send logs?

No

[robintown]

There probably was a point back in the full mesh era when this behavior was different, but I believe we've been forcing the microphone track on for about a year now. The reason is here in this comment:

element-call/src/livekit/useECConnectionState.ts

Lines 68 to 71 in 69b762b

	// livekit (by default) keeps the mic track open when you mute, but if you start muted,
	// doesn't publish it until you unmute. We want to publish it from the start so we're
	// always capturing audio: it helps keep bluetooth headsets in the right mode and
	// mobile browsers to know we're doing a call.

For example I think I remember that keeping the microphone track is what enables iOS to keep the call going when the browser is backgrounded. As a sanity check I just went through Zoom, Teams, Discord, and Jitsi, and it appears that all of them but Jitsi exhibit this same behavior when you mute. The Web platform just doesn't give us a better way to separate the intent to potentially share audio from whether audio actually gets captured, at the moment.