[mediacapture-main] deviceId not available on MediaStreamTrack

mhofman has just created a new issue for 
https://github.com/w3c/mediacapture-main:

== deviceId not available on MediaStreamTrack ==
It is currently impossible for an app to reliably identify the device 
corresponding to a track to which it was granted access to using 
`getUserMedia()`.
The only unique identifier is `MediaDeviceInfo`'s `deviceId` 
attribute, which doesn't exist on `MediaStreamTrack` objects. The 
`label` attribute is present on both objects but is not guaranteed to 
be unique (e.g. if 2 webcams of the same make/model are available). 

There are multiple use cases where this is needed, including:
- Application requests device access using `getUserMedia()` then shows
 a custom UI to the user to confirm selection of the device (aka 
"preview" feature). That UI might have an option to change the chosen 
devices based on results from device enumeration, where "highlighting"
 the currently active device is necessary.
- Application requests device access using `getUserMedia()` and 
directly uses whatever device was selected by the user in the User 
Agent's UI (or is the default if the UA doesn't ask the user to select
 a specific device). However, the application wants to "remember" the 
choice of the user so that it can request this specific device in 
subsequent visits.

Exposing a `deviceId` attribute on `MediaStreamTrack` objects would 
solve these use cases.

See https://github.com/w3c/mediacapture-main/issues/205

Received on Monday, 29 June 2015 22:45:30 UTC