On Feb 16, 2009, at 11:14 AM, Andrew Smith wrote: Thanks for the clarification.
One thing I am trying to understand, is if the input and output have different sample rates (I think this is possible on some devices),
They won't - there's only one sample rate being run at a given time at this point
Bill then which sample rate gets set / reported with the kAudioSessionProperty_PreferredHardwareSampleRate and kAudioSessionProperty_CurrentHardwareSampleRate commands?
Andrew On Feb 16, 2009, at 12:10 PM, William Stewart wrote: And just to be clear, if you have set preferred sample rates, etc, these only become active when the audio session is activated (which also asserts your category which may of course change the device from its present state as well)....
So: activate your audio session initialise the remote I/O
Then you will see on the device sides of this audio unit, the hardware sample rate - this should also be the same sample rate that is reported by the audio session property for the current hardware sample rate
Bill On Feb 14, 2009, at 9:40 AM, Doug Wyatt wrote: On Feb 13, 2009, at 19:22 , William Stewart wrote: On Feb 13, 2009, at 8:11 AM, Andrew Smith wrote:
I need to use audio units, and the only place that I could find to set a sample rate is in the stream format. But the device (framework?) seems to ignore this also. In fact, if I intercept a stream and check the format, the sample rate is set to 0.
That's on the remote I/O I think - the output side of bus 0 and the input side of bus 1 will be set to the sample rate of the hardware normally
the sample rates are zero before Initialize -- the AU isn't yet "connected" to the hardware and even if it were, the act of initialization can change the hardware sample rate
after Initialize, the sample rates are set to the hardware rate
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