Queries the relative rate of one timebase or clock relative to another timebase or clock.
- iOS 6.0+
- macOS 10.8+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 6.0+
- Core Media
If both have a common master, this calculation is performed purely based on the rates in the common tree rooted in that master.
If they have different master clocks (or are both clocks), this calculation takes into account the measured drift between the two clocks, using host time as a pivot. The rate of a moving timebase relative to a stopped timebase is a NaN. Calling
CMTimebaseis equivalent to calling