For a WebRTC stream, how can I get the devices that streams it?
For each stream there's getAudio/VideoTracks() and for each track there's getCapabilities().deviceId, but getCapabilities() doesn't seem to be implemented.
I tested in Firefox and Chrome.
You are right,
getCapabilities has not been implemented yet.
In the meantime use
track.kind and compare it against the device label and kind you get from
enumerateDevices. Works in Chrome and Firefox 46 (Firefox Developer Edition).