objectiveC/CMTime - convert AVPlayer.duration to milliseconds

Question

I'm creating an app for playing a ringtone and I'd want to know the current time in milliseconds of the played ringtone every time.

CMTime cTime = player_.currentTime; float currentTime = cTime.value / cTime.timescale;

That currentTime here gets the value in seconds. How can I get the exact currentTime value but in milliseconds?