MediaTrackSettings.volume - Web APIs 编辑

Obsolete

This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

The MediaTrackSettings dictionary's volume property is a double-precision floating-point number indicating the volume of the MediaStreamTrack as currently configured, as a value from 0.0 (silence) to 1.0 (maximum supported volume for the device). This lets you determine what value was selected to comply with your specified constraints for this property's value as described in the MediaTrackConstraints.volume property you provided when calling either getUserMedia() or MediaStreamTrack.applyConstraints().

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

Syntax

var volume = MediaTrackSettings.volume;

Value

A double-precision floating-point number indicating the volume, from 0.0 to 1.0, of the audio track as currently configured.

Example

See Example: Constraint exerciser in Capabilities, constraints, and settings for an example.

Browser compatibility

BCD tables only load in the browser

See also

• Media Capture and Streams API
• Capabilities, constraints, and settings
• MediaTrackConstraints.volume
• MediaTrackSettings