Re: [mediacapture-main] Should applyConstraints reject when track is muted? (#1029)

I agree this would be undesirable. Firstly, muted tracks aren't special.

The [spec](https://w3c.github.io/mediacapture-main/getusermedia.html#life-cycle) says UAs _"SHOULD relinquish"_ a device when all tracks are _"either [muted](https://w3c.github.io/mediacapture-main/getusermedia.html#track-muted) or [disabled](https://w3c.github.io/mediacapture-main/getusermedia.html#track-enabled)"_.

But it's optional, and reads like an optimization UAs are expected to undertake without disturbing the model, which is to apply constraints to the track, whether the device is acquired or not.

I'd expect when the track is re-enabled, the device comes back online with the track's constraints applied.

This is what Firefox does when it [relinquishes camera](https://blog.mozilla.org/webrtc/better-privacy-on-camera-mute-in-firefox-60/) on `track.muted` OR `track.enabled = false`.
- We don't currently do it on android or for microphone, but we have [prefs](https://searchfox.org/mozilla-central/rev/0f5273b9b232a3daa0a710e851cbb24393d62845/modules/libpref/init/all.js#277-278) to enable it
- We also have a `privacy.webrtc.globalMuteToggles` pref that adds UX to UA-mute our tracks.


> Also, it is unclear to me whether a UA can easily validate that the constraints will be respected when it does not have access to the device.

We do so in `getUserMedia` already.


-- 
GitHub Notification of comment by jan-ivar
Please view or discuss this issue at https://github.com/w3c/mediacapture-main/issues/1029#issuecomment-2734722161 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Tuesday, 18 March 2025 21:02:07 UTC