The MediaTrackConstraints
dictionary's groupId
property is a ConstrainDOMString
describing the requested or mandatory constraints placed upon the value of the groupId
constrainable property.
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.
Syntax
var constraintsObject = { groupId: constraint }; constraintsObject.groupId = constraint;
Value
An object based on ConstrainDOMString
specifying one or more acceptable, ideal, and/or exact (mandatory) group IDs which are acceptable as the source of media content.
Group IDs are unique for a given origin for the duration of a single browsing session, and are shared by all media sources that come from the same physical device. For example, the microphone and speaker on the same headset would share a group ID. This makes it possible to use the group ID to ensure that the audio and input devices are on the same headset by retrieving the group ID of the input device and specifying it when asking for an output device, perhaps.
However, the value of the groupId
is determined by the source of the track's content, and there's no particular format mandated by the specification (although some kind of GUID is recommended). That means that a given track will only return one value for the groupId
when you call getCapabilities()
, and keep in mind that this value will change for each browsing session.
Because of this, there's no use for the group ID when calling MediaStreamTrack.applyConstraints()
, since there is only one possible value, and you can't use it to ensure the same group is used across multiple browsing sessions when calling getUserMedia()
.
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 59 |
Edge
Full support ≤79 |
Firefox
Full support 70 |
IE
No support No |
Opera
Full support Yes |
Safari
? |
WebView Android
Full support 59 |
Chrome Android
Full support 59 |
Firefox Android
No support No |
Opera Android
? |
Safari iOS
? |
Samsung Internet Android
Full support 7.0 |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
See also
- Media Capture and Streams API
- Capabilities, constraints, and settings
MediaTrackConstraints
MediaDevices.getSupportedConstraints()
MediaTrackSupportedConstraints
MediaStreamTrack
MediaTrackConstraints.groupId by Mozilla Contributors is licensed under CC-BY-SA 2.5.