Can AudioKit play a sound while microphone is analyzing frequency? - audiokit

Question

I want to make an ear training app, so I want to make a sound while the microphone analyzes the frequency. I'm at the beginning to prove the concept, so for now, I just took AudioKit's sample app MicrophoneAnalisys and added some codes to make a sound.
import AudioKit
import AudioKitUI
import UIKit
class ViewController: UIViewController {
var oscillator1 = AKOscillator()
var oscillator2 = AKOscillator()
var mixer = AKMixer()
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
mixer = AKMixer(oscillator1, oscillator2)
mixer.volume = 0.5
AudioKit.output = mixer
do {
try AudioKit.start()
} catch {
AKLog("AudioKit did not start!")
}
}
var mic: AKMicrophone!
var tracker: AKFrequencyTracker!
var silence: AKBooster!
override func viewDidLoad() {
super.viewDidLoad()
AKSettings.audioInputEnabled = true
mic = AKMicrophone()
tracker = AKFrequencyTracker(mic)
silence = AKBooster(tracker, gain: 0)
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
AudioKit.output = silence
do {
try AudioKit.start()
} catch {
AKLog("AudioKit did not start!")
}
setupPlot()
Timer.scheduledTimer(timeInterval: 0.1,
target: self,
selector: #selector(ViewController.updateUI),
userInfo: nil,
repeats: true)
}
#objc func updateUI() {
if tracker.amplitude > 0.1 {
frequencyLabel.text = String(format: "%0.1f", tracker.frequency)
var frequency = Float(tracker.frequency)
while frequency > Float(noteFrequencies[noteFrequencies.count - 1]) {
frequency /= 2.0
}
while frequency < Float(noteFrequencies[0]) {
frequency *= 2.0
}
var minDistance: Float = 10_000.0
var index = 0
for i in 0..<noteFrequencies.count {
let distance = fabsf(Float(noteFrequencies[i]) - frequency)
if distance < minDistance {
index = i
minDistance = distance
}
}
let octave = Int(log2f(Float(tracker.frequency) / frequency))
noteNameWithSharpsLabel.text = "\(noteNamesWithSharps[index])\
(octave)"
noteNameWithFlatsLabel.text = "\(noteNamesWithFlats[index])\(octave)"
}
amplitudeLabel.text = String(format: "%0.2f", tracker.amplitude)
}
#IBAction func didTapASound(_ sender: Any) {
print("didTapASound")
mixer = AKMixer(oscillator1, oscillator2)
// Cut the volume in half since we have two oscillators
mixer.volume = 0.5
AudioKit.output = mixer
do {
try AudioKit.start()
} catch {
AKLog("AudioKit did not start!")
}
if oscillator1.isPlaying {
oscillator1.stop()
oscillator2.stop()
} else {
oscillator1.frequency = random(in: 220 ... 880)
oscillator1.start()
oscillator2.frequency = random(in: 220 ... 880)
// oscillator2.start()
}
}
I know I'm definitely doing wrong by trying to run
AudioKit.output = mixer
do {
try AudioKit.start()
} catch {
AKLog("AudioKit did not start!")
}
and
AudioKit.output = mixer
do {
try AudioKit.start()
} catch {
AKLog("AudioKit did not start!")
}
simultaneously.
I get the following errors.
[avae] AVAEInternal.h:70:_AVAE_Check: required condition is false: [AVAudioIONodeImpl.mm:910:SetOutputFormat: (IsFormatSampleRateAndChannelCountValid(hwFormat))]
*** Terminating app due to uncaught exception 'com.apple.coreaudio.avfaudio', reason: 'required condition is false: IsFormatSampleRateAndChannelCountValid(hwFormat)'
I read this article but couldn't understand whether the person asking the question was able to solve the problem. Can someone tell me if I can make a sound while putting the mic on with AudioKit and point me to the right direction where I can learn how I can do it? Thanks!

Answer 1

I'm answering my own question. Of course, it can make a sound and listen to a microphone simultaneously. All I had to do was to put them together with AKMixer.
var oscillator = AKOscillator()
var mic: AKMicrophone!
var tracker: AKFrequencyTracker!
var silence: AKBooster!
override func viewDidLoad() {
super.viewDidLoad()
AKSettings.audioInputEnabled = true
mic = AKMicrophone()
tracker = AKFrequencyTracker(mic)
silence = AKBooster(tracker, gain: 0)
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
AudioKit.output = AKMixer(silence,oscillator)
//AudioKit.output = silence
do {
try AudioKit.start()
} catch {
AKLog("AudioKit did not start!")
}
setupPlot()
Timer.scheduledTimer(timeInterval: 0.1,
target: self,
selector: #selector(ViewController.updateUI),
userInfo: nil,
repeats: true)
}
#IBAction func makeASound(_ sender: Any) {
if oscillator.isPlaying {
print("Stop A Sound")
oscillator.stop()
} else {
print("Make A Sound")
oscillator.amplitude = 1.0
oscillator.frequency = 440.0
oscillator.start()
}
}
Just in case someone has the same question..