The {{domxref("MediaTrackSettings")}} dictionary's latency
property is a double-precision floating-point number indicating the estimated latency (specified in seconds) of the {{domxref("MediaStreamTrack")}} as currently configured. This lets you determine what value was selected to comply with your specified constraints for this property's value as described in the {{domxref("MediaTrackConstraints.latency")}} property you provided when calling either {{domxref("MediaDevices.getUserMedia", "getUserMedia()")}} or {{domxref("MediaStreamTrack.applyConstraints()")}}.
This is, of course, an approximation, since latency can vary for many reasons including CPU, transmission, and storage overhead.
If needed, you can determine whether or not this constraint is supported by checking the value of {{domxref("MediaTrackSupportedConstraints.latency")}} as returned by a call to {{domxref("MediaDevices.getSupportedConstraints()")}}. However, typically this is unnecessary since browsers will simply ignore any constraints they're unfamiliar with.
Syntax
var latency = MediaTrackSettings.latency;
Value
A double-precision floating-point number indicating the estimated latency, in seconds, of the audio track as currently configured.
Example
See {{SectionOnPage("/en-US/docs/Web/API/Media_Streams_API/Constraints", "Example: Constraint exerciser")}} for an example.
Specifications
Specification | Status | Comment |
---|---|---|
{{ SpecName('Media Capture', '#widl-MediaTrackSettings-latency', 'latency') }} | {{ Spec2('Media Capture') }} | Initial specification. |
Browser compatibility
{{CompatibilityTable}}
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | {{CompatVersionUnknown}} | {{CompatNo}} | {{CompatNo}} | {{CompatVersionUnknown}} | {{CompatUnknown}} |
Feature | Android | Android Webview | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|
Basic support | {{CompatUnknown}} | {{CompatVersionUnknown}} | {{CompatNo}} | {{CompatNo}} | {{CompatUnknown}} | {{CompatUnknown}} | {{CompatVersionUnknown}} |
See also
- Media Capture and Streams API
- Capabilities, constraints, and settings
- {{domxref("MediaTrackConstraints.latency")}}
- {{domxref("MediaTrackSettings")}}