AudioTimeStamp's mHostTime & playatTime function

[lilzz]

I am trying to find the equivalent PlayatTime function of AVAudioplayer,
which would start to play at certain timeframe of the prerecorded audio.

I thought AudioTimeStamp's mHostTime would does it, but AudioTimeStamp.mHostTime=
CAHostTimeBase::GetCurrentTime() + theNumberOfSecondsInTheFuture * hostTimeFreq;


However, all it does is just adding a delay to prerecorded message.
if theNumberOfSecondsInTheFuture=1, the audio would play after 1 s, if =2, audio would play after 2s.

So, it's not quite what I am doing for. How do I implement the function of PlayatTime, which is only available if the latter OS.