Audiokit: AKMicrophone and Red Bar Forever

[trevor-sonic]

Hi, I have some issue with red bar which is appearing with recording.

My steps are;

Record Step:

• Setting Session .playAndRecord
• Initializing AKMicrophone
• AudioKit.Start
  (switch the app background mode _Red Bar is shown as expected, OK._)
  So I continue...

Playback Step:

• Stop AudioKit
• Stop connections (mixer, instruments etc.)
  microphone?.stop()
microphone?.detach()
microphone = nil
• Change Session to .playback
• Reconnect the Nodes (mixer etc)
• AudioKit.Start
  (switch the app background mode _Red Bar is still there!_)

After my research in framework I noticed that;
In Record Step; when we set the mic. device
...
microphone?.setDevice(frontMicrophone)
...
It is setting AVAudioSession.sharedInstance().setPreferredInput(device) and this connection is persisting even after; AudioKit.disconnectAllInputs() and Stop|Start AudioKit. That's why Red Bar Forever

My expectation:
I think, AudioKit.disconnectAllInputs() should remove this connection.
Or restarting AudioKit should set it to initial/nil value

If non of these suppose to accomplish this, Can we add a new method like; resetPreferredInput() ?

[aure]

I think both of your expectations should be put into place and maybe the method too. Do you want to add this and make a PR?

[mglodack]

@trevor-sonic I was also experiencing this issue when trying to switch between recording and a simple playback mode. I do agree with your expectation that AudioKit should handle this.

To get around the issue for now, I decided to always breakdown the nodes and reset AudioKit when transitioning between recording and playback. I came up with these steps that seemed to work...stop all the nodes and AudioKit followed by calling shutdown on AudioKit and resetting the AudioKit output to nil. I couldn't find any information whether creating and breaking down nodes causes any sort of memory problems. 🤷‍♂️

do {
   mic?.stop()
   <another_node>?.stop()

   try AudioKit.stop()
   try AudioKit.shutdown()
   AudioKit.output = nil

   mic = nil
} catch {
// TODO: Handle error
}

[trevor-sonic]

Hi @mglodack, AudioKit.output = nil is changing the Red Bar Forever issue but it is so expensive for me because all the connected nodes, mixer... must be reinitialized ( I actually just use .stop() when I restart AudioKit for session changes.

@aure I'll dig into it but I'm not sure, it looks like it's beyond my knowledge.

Thank you all, at least now I know about the issue more precisely.

[trevor-sonic]

I've tried many work around creating a function for testing to reset/forget the input already set.
Something like;
func resetInputDevice(){ do{ try AVAudioSession.sharedInstance().setPreferredInput(nil) }catch{ print(error) } }

But it is not unset the mic.
Apple says (in the var definition) "Setting a nil value will clear the preference." but it doesn't work in the way that I expect.
Anyway only way to remove this Red Bar Forever is @mglodack 's method.
I just wanted to let the others know, if they struggle with the same problem.

[aure]

https://github.com/AudioKit/AudioKit/issues/1271

[ryangenz]

Did this issue happen to get addressed in the 5.0 beta for future release?