How to select specific alternate interface setting of connected USB Audio device in iOS?

Hi,


I am using a USBAudio device connected to the iPhone for recording audio. This USB audio device has two alternate settings. I want to be able to choose between either of the alternate setting 1 or 2 depending upon some recording requirements in the app. But, currently iOS is always selecting alternate setting 1.


So my query is,


1. Is there any way to choose between USB alternate settings from app side in iOS? (I am using AVAudioSession and AudioUnit for recording).


2. If this control is not possible in the app, what is the creiteria on which iOS decides which alternate setting to be used?


Thanks,

Up vote post of vinayak_tymtix Down vote post of vinayak_tymtix
1.8k views
Posted by
vinayak_tymtix
Reply
Add a Comment

Replies

hi , I have the same problem as yours


And I can't find any related solution , so I send a Apple TSI request


Because it is difficult for us develop on USB audio device


ie. I'm using Apogee Quartet , It require connect the lightninh cable , so I can't see the log or real time event ...


And it need two steps to setting the input


1.Select the device you prefer -> ie. Build in microphone or external audio device

2.Select specific inputs / outputs -> ie. If external device has more than one input , you need to select the specific one


If I have any reply , I will let you know

Posted by
WebberLai
Up vote reply of WebberLai Down vote reply of WebberLai
Add a Comment

Did you check the routing through the USB drivers with notifications? or for an interrupt? register for notifications and see if you get an interrupt or a change notice.


You might need to add a function/delegate to check the equivalent of AVAudioEngineConfigurationChangeNotification.

Posted by
iPad_dev
Up vote reply of iPad_dev Down vote reply of iPad_dev
Add a Comment

Has anyone ever figured this out?

I have tried to find info everywhere about multichannel audio with USB interfaces. more specifically, how (using an APogee quartet) would I select specific pair of stereo outs and make that the device's default output?

Posted by
shahasad78
Up vote reply of shahasad78 Down vote reply of shahasad78
Add a Comment