Re: Channel Maps and HALOutputUnit
Re: Channel Maps and HALOutputUnit
- Subject: Re: Channel Maps and HALOutputUnit
- From: Aaron Eppolito <email@hidden>
- Date: Tue, 10 Feb 2004 11:06:25 -0800
On Feb 10, 2004, at 10:05 AM, Robert Grant wrote:
If I've got a 6 input - 2 output audio device that I want to bring
into my app as 3 stereo input busses can I do that? Bill's example
focusses on a single stereo bus into a multi-channel device.
You can get all 6 channels in the same call to AudioUnitRender(). Feel
free to interpret them as any pairing that you like.
And if I can - how does it affect the input RenderCallback?
It doesn't change the render callback itself, but you will get more
channels in your call to AudioUnitRender().
And I guess the same goes for output too. If I have a 2 input - 6
output device can I configure the output unit so that I can feed it 3
stereo busses?
For input, you'd want to create a SInt32 array something like:
SInt32 inputChannelsAllSixInputs[] = {0, 1, 2, 3, 4, 5};
or SInt32 inputChannelsFourOfTheSixInputs[] = {0, 1, 4, 5};
For output, you'd create the same:
SInt32 outputChannelsOneTwoFiveAndSix[] = {0, 1, -1, -1, 2, 3}
(this would give you four channels, sourced with channels 1, 2, 5 & 6)
Your audio buffer list will need to contain as many buffers of mono
channels as you ask for channels from the device. In your
AudioUnitRender() callback, you will end up with N deinterleaved
buffers, where N is the number of channels specified in the ChannelMap.
Same goes for the callback for output too.
-Aaron
_______________________________________________
coreaudio-api mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/coreaudio-api
Do not post admin requests to the list. They will be ignored.