The MediaTrackConstraints dictionary's suppressLocalAudioPlayback property is a ConstrainBoolean describing the requested or mandatory constraints placed upon the value of the suppressLocalAudioPlayback constrainable property. This property controls whether the audio playing in a tab will continue to be played out of a user's local speakers when the tab is captured.

If needed, you can determine whether or not this constraint is supported by checking the value of MediaTrackSupportedConstraints.suppressLocalAudioPlayback as returned by a call to MediaDevices.getSupportedConstraints(). However, typically this is unnecessary since browsers will ignore any constraints they're unfamiliar with.

A ConstrainBoolean value.

If this value is a simple true or false, the user agent will attempt to obtain media with local audio playback enabled or disabled as specified, if possible, but will not fail if this can't be done.

If the value is given as ideal, that field's boolean value indicates an ideal setting for the local audio playback suppression feature; if it can't be met, then the request will result in an error.

let isLocalAudioSuppressed = displayStream
  .getVideoTracks()[0]
  .getSettings().suppressLocalAudioPlayback;

The Constraint exerciser example shows how to use media track constraints.

• Media Capture and Streams API
• Capabilities, constraints, and settings
• MediaTrackConstraints
• MediaDevices.getSupportedConstraints()
• MediaTrackSupportedConstraints
• MediaStreamTrack