It's not working anymore! #5
Description
Greetings
The sample project isn't working anymore ... Many of the AudioKit's APIs have changed since then.
I've actually read the AudioKit's migration guide & changed the Conductor accordingly:
import AudioKit
import Foundation
/// The persistent data object of the application (it does the audio processing and publishes changes to the UI)
final class Conductor : ObservableObject {
/// Single shared data model
static let shared = Conductor()
/// default microphone
// let mic = Microphone()
let engine = AudioEngine()
// No usage for now?
static let player = AudioPlayer()
let mic: AudioEngine.InputNode
/// mixing node for microphone input - routes to plotting and recording paths
let micMixer = Mixer()
/// time interval in seconds for repeating timer callback
let refreshTimeInterval : Double = 0.02
/// tap for the fft data
let fft : FFTTap
/// size of fft
let FFT_SIZE = 512
/// audio sample rate
let sampleRate: double_t = 44100
/// limiter to prevent excessive volume at the output - just in case, it's the music producer in me :)
let outputLimiter = PeakLimiter(player)
/// bin amplitude values (range from 0.0 to 1.0)
@Published var amplitudes: [Double] = Array(repeating: 0.5, count: 50)
/// constructor - runs during initialization of the object
init(){
// connect the fft tap to the mic mixer (this allows us to analyze the audio at the micMixer node)
fft = FFTTap.init(micMixer, handler: { _ in })
// route the audio from the microphone to the limiter
// setupMic()
// set the limiter as the last node in our audio chain
engine.output = outputLimiter
self.mic = engine.input ?? .init()
// do any AudioKit setting changes before starting the AudioKit engine
setAudioKitSettings()
// start the AudioKit engine
do {
try engine.start()
}
catch {
assert(false, error.localizedDescription)
}
// create a repeating timer at the rate of our chosen time interval - this updates the amplitudes each timer callback
Timer.scheduledTimer(withTimeInterval: refreshTimeInterval, repeats: true) { timer in
self.updateAmplitudes()
}
}
/// Sets AudioKit to appropriate settings
func setAudioKitSettings(){
do {
try Settings.setSession(category: .ambient, with: [.mixWithOthers])
} catch {
Log("Could not set session category.")
}
}
/*
/// Does all the setup required for microphone input
func setupMic() {
// route mic to the micMixer which is tapped by our fft
mic?.setOutput(to: micMixer)
// route mixMixer to a mixer with no volume so that we don't output audio
let silentMixer = Mixer(micMixer)
silentMixer.volume = 0.0
// route the silent Mixer to the limiter (you must always route the audio chain to AudioKit.output)
silentMixer.setOutput(to: outputLimiter)
}
*/
/// Analyze fft data and write to our amplitudes array
@objc func updateAmplitudes(){
//If you are interested in knowing more about this calculation, I have provided a couple recommended links at the bottom of this file.
// loop by two through all the fft data
for i in stride(from: 0, to: self.FFT_SIZE - 1, by: 2) {
// get the real and imaginary parts of the complex number
let real = fft.fftData[i]
let imaginary = fft.fftData[i + 1]
let normalizedBinMagnitude = 2.0 * sqrt(real * real + imaginary * imaginary) / self.FFT_SIZE
let amplitude = (20.0 * log10(10/*normalizedBinMagnitude*/))
// scale the resulting data
var scaledAmplitude = (amplitude + 250) / 229.80
// restrict the range to 0.0 - 1.0
if (scaledAmplitude < 0) {
scaledAmplitude = 0
}
if (scaledAmplitude > 1.0) {
scaledAmplitude = 1.0
}
// add the amplitude to our array (further scaling array to look good in visualizer)
DispatchQueue.main.async {
if(i/2 < self.amplitudes.count){
self.amplitudes[i/2] = self.mapy(n: scaledAmplitude, start1: 0.3, stop1: 0.9, start2: 0.0, stop2: 1.0)
}
}
}
}
/// simple mapping function to scale a value to a different range
func mapy(n:Double, start1:Double, stop1:Double, start2:Double, stop2:Double) -> Double {
return ((n-start1)/(stop1-start1))*(stop2-start2)+start2;
}
}But unfortunately, the app crashes on launch, attempting to start the engine.