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Re: A number of simple questions (still a few unanswered)
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Re: A number of simple questions (still a few unanswered)

  • Subject: Re: A number of simple questions (still a few unanswered)
  • From: Paul Davis <email@hidden>
  • Date: Wed, 06 Feb 2013 18:58:14 -0500
i'll use <incorrect><humor> tags next time


On Wed, Feb 6, 2013 at 4:45 PM, James McCartney <email@hidden> wrote:

On Dec 5, 2012, at 12:11 PM, Paul Davis <email@hidden> wrote:



On Wed, Dec 5, 2012 at 2:14 PM, Seth Willits <email@hidden> wrote:

Still a few I'm unsure about. :)


- Why is AudioTimeStamp.mSampleTime a float if it's an integer number of samples?

because apple don't want accurate timestamps beyond 12 (or even 6 hours).</sarcasm>

Answering an old question, but this is wrong. 

mSampleTime is a Float64.

Float64s have 52 bits of mantissa. With the implicit one bit, that gives 2^53 representable nonnegative integers.

Let's say you are running at 192000 samples per second.
   3600 seconds per hour
   24 hours per day
   365.25 days per year

pow(2,53) / 192000 / 3600 / 24 / 365.25 = 1486.57 years before loss of sample accuracy.



James McCartney
Apple CoreAudio
email@hidden




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 >Re: A number of simple questions (still a few unanswered) (From: James McCartney <email@hidden>)

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