A callback to the host for transport state information.
- iOS 10.0+
- macOS 10.12+
- Mac Catalyst 13.0+
- tvOS 10.0+
An audio unit accessing this property should cache it in realtime-safe storage before beginning to render.
This version 3 property is bridged to the version 2
Host callback members in the kAudioUnitProperty_HostCallbacks API.