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RE: SampleTime
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RE: SampleTime


  • Subject: RE: SampleTime
  • From: Jim Dolan <email@hidden>
  • Date: Thu, 13 Dec 2001 11:04:38 -0500

Jeff -

I tried to look at the archives but I don't know what they username should
be to log on... I tried my email address and it did not work...

Could someone please give me a good description of how an AudioTimeStamp is
used.
I am trying calculate sample position in my media using the timestamps. If
I can not rely on the initial sample to be zero how do I create the offsets?
What is mHostTime in relation to mSampleTime. What is mRateScalar? and how
is it used?

I understand that I should be taking the difference between the IOprocs and
not rely on absolute values, but how do I calculate sample position between
the time I start and the first IOproc?

If I ask the device for the current time before I start it will give me some
large number for mSampleTime. (Even if the device is not started yet - No
other applications running etc). Way is this not zero? If I ask again after
I call AudioDeviceStart and before the first IOProc I get a completely
different number - something close to zero.
If the device is really already going then why do I get this change in
mSampleTime once I tell it to start?

Jim Dolan



-----Original Message-----

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