A Boolean value that indicates the total duration of fragments that either exist now or may be appended in the future in order to extend the duration of the asset.
- iOS 10.2+
- macOS 10.12.2+
- tvOS 10.2+
For QuickTime movie files and MPEG-4 files, the value of this property is obtained from the
mehd box of the
mvex box, if present. If no total fragment duration hint is available, the value of this property is