MediaStreamTrack: getCapabilities() method

The getCapabilities() method of the MediaStreamTrack interface returns a MediaTrackCapabilities object which specifies the values or range of values which each constrainable property, based upon the platform and user agent.

Once you know what the browser's capabilities are, your script can use applyConstraints() to ask for the track to be configured to match ideal or acceptable settings. See Capabilities, constraints, and settings for details on how to work with constrainable properties.

Syntax

js
getCapabilities()

Parameters

None.

Return value

A MediaTrackCapabilities object which specifies the value or range of values which are supported for each of the user agent's supported constrainable properties, containing the following members:

deviceId

A ConstrainDOMString object containing the device ID.

groupId

A ConstrainDOMString object containing a group ID.

autoGainControl

A ConstrainBoolean object reporting if the source can do auto gain control. If the feature can be controlled by a script the source will report both true and false as possible values.

channelCount

A ConstrainULong containing the channel count or range of channel counts.

echoCancellation

A ConstrainBoolean object reporting if the source can do echo cancellation. If the feature can be controlled by a script the source will report both true and false as possible values.

latency

A ConstrainDouble containing the latency or range of latencies.

noiseSuppression

A ConstrainBoolean object reporting if the source can do noise suppression. If the feature can be controlled by a script the source will report both true and false as possible values.

sampleRate

A ConstrainULong containing the sample rate or range of sample rates.

sampleSize

A ConstrainULong containing the sample size or range of sample sizes.

aspectRatio

A ConstrainDouble containing the video aspect ratio (width in pixels divided by height in pixels) or range of aspect ratios.

facingMode

A ConstrainDOMString object containing the camera facing mode. A camera may report multiple facings, for example "left" and "user".

frameRate

A ConstrainDouble containing the frame rate or range of frame rates which are acceptable.

height

A ConstrainULong containing the video height or range of heights in pixels.

width

A ConstrainULong containing the video width or range of widths in pixels.

resizeMode

A ConstrainDOMString object containing the mode or an array of modes the UA can use to derive the resolution of the video track.

Specifications

Specification
Media Capture and Streams
# dom-mediastreamtrack-getcapabilities

Browser compatibility

BCD tables only load in the browser

See also