Re: Built-in audio controller - kAudioHardwareIllegalOperationError
Re: Built-in audio controller - kAudioHardwareIllegalOperationError
- Subject: Re: Built-in audio controller - kAudioHardwareIllegalOperationError
- From: Jeff Moore <email@hidden>
- Date: Tue, 05 Mar 2002 11:44:00 -0800
on 3/5/02 7:32 AM, Andreas Doerr <email@hidden> wrote:
>
Later the application tries to add two IO procedures through the
>
"AudioDeviceAddIOProc()". One for the output device and one for the
>
input device. Adding the output IO procedure succeeds. Adding the input,
>
i.e. second, IO procedure (using the same device id) fails. The error is
>
"kAudioHardwareIllegalOperationError".
This is most likely because you attempting to add the same IOProc twice.
This is, as the error indicates, illegal in the 10.1.x HAL.
The good news is that you don't need the second IOProc since the built-in
hardware delivers the input data and the output data at the same time in the
same IOProc. In fact, having the second IOProc is _very_ wasteful of system
resources since the HAL has to allocate a bunch of wired memory for each
IOProc that is registered. In this case, the extra memory allocated is going
to be totally unused. This is not a good thing.
It is recommended practice with the HAL to have as few IOProcs as you can.
--
Jeff Moore
Core Audio
Apple
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