Spec should make use of https://w3c.github.io/mediacapture-main/#dfn-create-a-mediastreamtrack to create MediaStreamTrack

[youennf]

This would make sure that source is registered on the document that created it.

[alvestrand]

I assume that "mediaDevicesToTieSourceTo" is null here. So the operation is calling "MediaStreamTrack source-specific constructions steps", which is null unless otherwise specified. Do they need specification?

The call(s) to "create a mediastreamtrack" would be part of what happens in "Prompt the user to choose", which retuns "options", but the caller in createDisplayMedia() assumes that what's returned is either tracks or "denied".

[youennf]

I assume that "mediaDevicesToTieSourceTo" is null here

No, it would be the mediaDevices object used when calling mediaDevices.getDisplayMedia.

[youennf]

Following on today's editor meeting, the way MediaStreamTrack transfer is defined was discussed in 2021 and ended up in a successful CfC on 09/30/2021.
That led to the current addition to media capture-extensions, which is clear about the lifetime of capture tracks, in particular:

When originalContext goes away, trackSource gets ended, thus transferredTrack gets ended.

We can of course revisit this once we have more use cases (for instance we are also discussing in parallel whether to restrict transfer to same agent cluster).
In the meantime, I think this issue and the related PR are just editorial.

@eladalon1983, wdyt?