KMP iOS multiple audio engines

December 27, 2024

What's inside this article ⌄

Kotlin Multiplatform IOS audio engines
Multiple avaudioengine IOS KMP
Kotlin IOS audio engine conflict
KMP IOS audio implementation

It’s possible to have multiple instance of AVAudioEngine in the same app, for example one for mic recording, one for playing a sound.

private var recordEngine: AVAudioEngine = AVAudioEngine()
private var playbackEngine: AVAudioEngine = AVAudioEngine()

But we can find out that without proper configuration it won’t work. The thing is that we should setup an audio session:

init {
    setupAudioSession()
}

Respective method will look like this:

private fun setupAudioSession() {
    val audioSession = AVAudioSession.sharedInstance()
    try {
        audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord, null)
        audioSession.setActive(true, null)
    } catch (e: Exception) {
        println("Failed to set audio session category: ${e.message}")
    }
}

Audio play and record operations should work as expected from now on.