The {{domxref("MediaTrackConstraints")}} dictionary's frameRate
property is a {{domxref("ConstrainDouble")}} describing the requested or mandatory constraints placed upon the value of the {{domxref("MediaTrackSettings.frameRate", "frameRate")}} constrainable property.
If needed, you can determine whether or not this constraint is supported by checking the value of {{domxref("MediaTrackSupportedConstraints.frameRate")}} 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 constraintsObject = { frameRate: constraint }; constraintsObject.frameRate = constraint;
Value
A {{domxref("ConstrainDouble")}} describing the acceptable or required value(s) for a video track's frame rate, in frames per second.
If this value is a number, the user agent will attempt to obtain media whose frame rate is as close as possible to this number given the capabilities of the hardware and the other constraints specified. Otherwise, the value of this {{domxref("ConstrainDouble")}} will guide the user agent in its efforts to provide an exact match to the required frame rate (if exact
is specified or both min
and max
are provided and have the same value) or to a best-possible value.
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-MediaTrackConstraints-frameRate', 'frameRate') }} | {{ Spec2('Media Capture') }} | Initial specification. |
Browser compatibility
{{CompatibilityTable}}
Feature | Chrome | Firefox (Gecko) | Microsoft Edge | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | {{CompatVersionUnknown}} | {{CompatGeckoDesktop(50)}} | {{CompatUnknown}} | {{CompatNo}} | {{CompatVersionUnknown}} | {{CompatUnknown}} |
Feature | Android | Android Webview | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|
Basic support | {{CompatUnknown}} | {{CompatVersionUnknown}} | {{CompatGeckoMobile(50)}} | {{CompatNo}} | {{CompatUnknown}} | {{CompatUnknown}} | {{CompatVersionUnknown}} |
See also
- Media Capture and Streams API
- Capabilities, constraints, and settings
- {{domxref("MediaTrackConstraints")}}
- {{domxref("MediaDevices.getSupportedConstraints()")}}
- {{domxref("MediaTrackSupportedConstraints")}}
- {{domxref("MediaStreamTrack")}}