MediaStreamTrack: enabled property
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2017.
The enabled
property of the
MediaStreamTrack
interface is a Boolean value which is
true
if the track is allowed to render the source stream or
false
if it is not. This can be used to intentionally mute a
track.
When enabled, a track's data is output from the source to the destination; otherwise, empty frames are output.
In the case of audio, a disabled track generates frames of silence (that is, frames in which every sample's value is 0). For video tracks, every frame is filled entirely with black pixels.
The value of enabled
, in essence, represents what a typical user would
consider the muting state for a track, whereas the muted
property indicates a state in which the track is temporarily unable to output
data, such as a scenario in which frames have been lost in transit.
Note: If the track has been disconnected, the value of this property can be changed, but has no effect.
Value
When true
, enabled
indicates that the track is permitted to
render its actual media to the output. When enabled
is set to
false
, the track only generates empty frames.
Empty audio frames have every sample's value set to 0. Empty video frames have every pixel set to black.
Note: When implementing a mute/unmute feature, you should use the
enabled
property.
Usage notes
If the MediaStreamTrack
represents the video input from a camera,
disabling the track by setting enabled
to false
also updates
device activity indicators to show that the camera is not currently recording or
streaming. For example, the green "in use" light next to the camera in iMac and MacBook
computers turns off while the track is muted in this way.
Example
This example demonstrates a click
event handler for a pause button.
pauseButton.onclick = (evt) => {
const newState = !myAudioTrack.enabled;
pauseButton.innerHTML = newState ? "▶️" : "⏸️";
myAudioTrack.enabled = newState;
};
This creates a variable, newState
, which is the opposite of the current
value of enabled
, then uses that to select either the Emoji character for
the "play" icon or the character for the "pause" icon as the new
innerHTML
of the pause button's element.
Finally, the new value of enabled
is saved, making the change take effect.
Specifications
Specification |
---|
Media Capture and Streams # dom-mediastreamtrack-enabled |
Browser compatibility
BCD tables only load in the browser