The frame number of an animation to use as a thumbnail image.
- iOS 10.0+
- tvOS 10.0+
- watchOS 3.0+
For animated images, the value of this key is an
NSNumber containing the frame number to use as the thumbnail. For movies, the value of this key is the time (in seconds) into the movie from which to grab the thumbnail image; you may also specify the value as a
CMTime structure encoded using the