The MediaTrackSettings
dictionary's groupId
property is a browsing-session unique DOMString
which identifies the group of devices which includes the source for the MediaStreamTrack
. This lets you determine what value was selected to comply with your specified constraints for this property's value as described in the MediaTrackConstraints.groupId
property you provided when calling either getUserMedia()
.
If needed, you can determine whether or not this constraint is supported by checking the value of MediaTrackSupportedConstraints.groupId
as returned by a call to MediaDevices.getSupportedConstraints()
. However, typically this is unnecessary since browsers will simply ignore any constraints they're unfamiliar with.
Because RTP doesn't include this information, tracks associated with a WebRTC RTCPeerConnection
will never include this property.
Syntax
var groupId = MediaTrackSettings.groupId;
Value
A DOMString
whose value is a browsing-session unique identifier for a group of devices which includes the source of the track's contents. Two devices share the same group ID if they belong to the same physical hardware device. For example, a headset has two devices on it: a microphone which can serve as a source for audio tracks and a speaker which can serve as an output for audio.
The group ID is not usable across multiple browsing sessions. However, it can be used to ensure that audio input and output are both being performed on the same headset, for example, or to ensure that the built-in camera and microphone on a phone are being used for video conferencing purposes.
The actual value of the string, however, is determined by the source of the track, and there is no guarantee what form it will take, although the specification does recommend it be a GUID.
Since this property isn't stable across browsing sessions, its usefulness when calling getUserMedia()
is generally limited to ensuring that tasks performed during the same browsing session use devices from the same group (or that they don't use devices from the same group). There is no situation in which the groupId is useful when calling applyConstraints()
, since the value can't be changed.
Example
See Example: Constraint exerciser in Capabilities, constraints, and settings for an example.
Specifications
Specification | Status | Comment |
---|---|---|
Media Capture and StreamsThe definition of 'groupId' in that specification. | Candidate Recommendation | Initial specification. |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Update compatibility data on GitHub
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
groupId
|
Chrome
Full support Yes |
Edge
Full support ≤79 |
Firefox
Full support 69 |
IE
No support No |
Opera
Full support Yes |
Safari
? |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
No support No |
Opera Android
Full support Yes |
Safari iOS
? |
Samsung Internet Android
Full support Yes |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
See also
- Media Capture and Streams API
- Capabilities, constraints, and settings
MediaTrackSettings.deviceId
MediaTrackConstraints.groupId
MediaTrackSettings
MediaTrackSettings.groupId by Mozilla Contributors is licensed under CC-BY-SA 2.5.