The currently active minimum frame duration.
- iOS 7.0+
- macOS 10.7+
A device’s minimum frame duration is the reciprocal of its maximum frame rate. You can set the value of this property to limit the maximum frame rate during a capture session. The capture device automatically chooses a default minimum frame duration based on its active format. After changing the value of this property, you can return to the default minimum frame duration by setting this property’s value to
invalid. Choosing a new preset for the capture session also resets this property to its default value.
Before changing the value of this property, you must call
lock to acquire exclusive access to the device’s configuration properties. Otherwise, setting the value of this property raises an exception. When you are done configuring the device, call
unlock to release the lock and allow other devices to configure the settings.
You can observe changes to the value of this property using Key-value observing.