Re: ChannelMap and SampleRate change weirdness
Re: ChannelMap and SampleRate change weirdness
- Subject: Re: ChannelMap and SampleRate change weirdness
- From: Robert Grant <email@hidden>
- Date: Thu, 17 Jun 2004 15:40:46 -0400
Hi Doug - thanks for responding.
On Jun 17, 2004, at 2:37 PM, Doug Wyatt wrote:
No matter how many channels I ask for when configuring my input AUHAL
AudioUnitRender tells me that it has just two channels (this used to
work before I'm sure of it.??? !!!)
How many channels does the device have?
Airy has 4 channels of input on his Tascam device.
Are you speaking of the number of buffers in the buffer list returned
by AudioUnitRender?
Yeah - because in de-interleaved format buffers = channels no?
What are the input and output stream descriptions for bus 1?
Unsure but as I want everything to be canonical I haven't messed with
them. Doesn't the AUHAL present input in canonical form by default?
After changing the sample rate from 44.1 to something else (and
reinitializing everything) AudioUnitRender tells me -10863
CannotDoInCurrentContext.
What are the possible reasons an AUHAL would return this error? The
only thing I can think of is that it is being asked to do a sample
rate conversion - but I've set the device to be the new sample rate
before initializing the AUHAL Or perhaps it thinks it's being called
from the wrong thread? But it's on the main graph render thread.
It has to be getting called on the device's IOProc thread for the
exact same number of samples that were supplied by the IOProc. If
element 1's input and output sample rates do not match, you will get a
sample rate conversion and this will result in the -10863 error.
So you're saying that I should pass the inNumberFrames from the
callback to the AudioUnitRender? I'm doing that already.
What steps would you take to change the SampleRate of a device when
using AUHAL?
I stop and tear down the old AUHAL. Set the sample rate on the device.
Build a new AUHAL and start it - where upon I get the -10863 error. I
don't see where the mismatch could come in?
Thanks,
Robert.
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