When called by the system, provides audio transport state and timeline information to an audio unit from a host application.
- iOS 10.0+
- macOS 10.12+
- Mac Catalyst 13.0+
- tvOS 10.0+
Custom data that you provided when registering your callback with the audio unit.
TRUEif audio is playing, or
TRUEif the transport state changed since the last time the callback was invoked, or
On output, the sample number, indexed from zero from the beginning of the timeline.
TRUEif cycling, or
If you named your callback function
My, you would declare it like this: