I'm trying to record audio, then save offline with AudioKit.renderToFile, then use AKPlayer to play the original recorded audio file.
import UIKit
import AudioKit
class ViewController: UIViewController {
private var recordUrl:URL!
private var isRecording:Bool = false
public var player:AKPlayer!
private let format = AVAudioFormat(commonFormat: .pcmFormatFloat64, sampleRate: 44100, channels: 2, interleaved: true)!
private var amplitudeTracker:AKAmplitudeTracker!
private var boostedMic:AKBooster!
private var mic:AKMicrophone!
private var micMixer:AKMixer!
private var silence:AKBooster!
public var recorder: AKNodeRecorder!
@IBOutlet weak var recordButton: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
//self.recordUrl = Bundle.main.url(forResource: "sound", withExtension: "caf")
//self.startAudioPlayback(url: self.recordUrl!)
self.recordUrl = self.urlForDocument("record.caf")
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func requestMic(completion: @escaping () -> Void) {
AVAudioSession.sharedInstance().requestRecordPermission({ (granted: Bool) in
if granted { completion()}
})
}
public func switchToMicrophone() {
stopEngine()
do {
try AKSettings.setSession(category: .playAndRecord, with: .allowBluetoothA2DP)
} catch {
AKLog("Could not set session category.")
}
mic = AKMicrophone()
micMixer = AKMixer(mic)
boostedMic = AKBooster(micMixer, gain: 5)
amplitudeTracker = AKAmplitudeTracker(boostedMic)
silence = AKBooster(amplitudeTracker, gain: 0)
AudioKit.output = silence
startEngine()
}
@IBAction func startStopRecording(_ sender: Any) {
self.isRecording = !self.isRecording
if self.isRecording {
self.startRecording()
self.recordButton.setTitle("Stop Recording", for: .normal)
} else {
self.stopRecording()
self.recordButton.setTitle("Start Recording", for: .normal)
}
}
func startRecording() {
self.requestMic() {
self.switchToMicrophone()
if let url = self.recordUrl {
do {
let audioFile = try AKAudioFile(forWriting: url, settings: self.format.settings, commonFormat: .pcmFormatFloat64, interleaved: true)
self.recorder = try AKNodeRecorder(node: self.micMixer, file: audioFile)
try self.recorder.reset()
try self.recorder.record()
} catch {
print("error setting up recording", error)
}
}
}
}
func stopRecording() {
recorder.stop()
startAudioPlayback(url: self.recordUrl)
}
@IBAction func saveToDisk(_ sender: Any) {
if let source = self.player, let saveUrl = self.urlForDocument("pitchAudio.caf") {
do {
source.stop()
let audioFile = try AKAudioFile(forWriting: saveUrl, settings: self.format.settings, commonFormat: .pcmFormatFloat64, interleaved: true)
try AudioKit.renderToFile(audioFile, duration: source.duration, prerender: {
source.play()
})
print("audio file rendered")
} catch {
print("error rendering", error)
}
// PROBLEM STARTS HERE //
self.startAudioPlayback(url: self.recordUrl)
}
}
public func startAudioPlayback(url:URL) {
print("loading playback audio", url)
self.stopEngine()
do {
try AKSettings.setSession(category: .playback)
player = AKPlayer.init()
try player.load(url: url)
}
catch {
print("error setting up audio playback", error)
return
}
player.prepare()
player.isLooping = true
self.setPitch(pitch: self.getPitch(), saveValue: false)
AudioKit.output = player
startEngine()
startPlayer()
}
public func startPlayer() {
if AudioKit.engine.isRunning { self.player.play() }
else { print("audio engine not running, can't play") }
}
public func startEngine() {
if !AudioKit.engine.isRunning {
print("starting engine")
do { try AudioKit.start() }
catch {
print("error starting audio", error)
}
}
}
public func stopEngine(){
if AudioKit.engine.isRunning {
print("stopping engine")
do {
try AudioKit.stop()
}
catch {
print("error stopping audio", error)
}
}
//playback doesn't work without this?
mic = nil
}
@IBAction func changePitch(_ sender: UISlider) {
self.setPitch(pitch:Double(sender.value))
}
public func getPitch() -> Double {
return UserDefaults.standard.double(forKey: "pitchFactor")
}
public func setPitch(pitch:Double, saveValue:Bool = true) {
player.pitch = pitch * 1000.0
if saveValue {
UserDefaults.standard.set(pitch, forKey: "pitchFactor")
UserDefaults.standard.synchronize()
}
}
func urlForDocument(_ named:String) -> URL? {
let path = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as String
let url = NSURL(fileURLWithPath: path)
if let pathComponent = url.appendingPathComponent(named) {
return pathComponent
}
return nil
}
}
The order of calls is switchToMicrophone, startRecording, stopRecording, startAudioPlayback, saveToDisk, and again, startAudioPlayback
Please see the github repo for full code in ViewController.swift
After the renderToFile function, when restarting AudioKit for the player, the following errors occur:
[mcmx] 338: input bus 0 sample rate is 0
[avae] AVAEInternal.h:103:_AVAE_CheckNoErr: [AVAudioEngineGraph.mm:1265:Initialize: (err = AUGraphParser::InitializeActiveNodesInOutputChain(ThisGraph, kOutputChainOptimizedTraversal, *GetOutputNode(), isOutputChainActive)): error -10875
[avae] AVAudioEngine.mm:149:-[AVAudioEngine prepare]: Engine@0x1c4008ae0: could not initialize, error = -10875
[mcmx] 338: input bus 0 sample rate is 0
[avae] AVAEInternal.h:103:_AVAE_CheckNoErr: [AVAudioEngineGraph.mm:1265:Initialize: (err = AUGraphParser::InitializeActiveNodesInOutputChain(ThisGraph, kOutputChainOptimizedTraversal, *GetOutputNode(), isOutputChainActive)): error -10875
error starting audio Error Domain=com.apple.coreaudio.avfaudio Code=-10875 "(null)" UserInfo={failed call=err = AUGraphParser::InitializeActiveNodesInOutputChain(ThisGraph, kOutputChainOptimizedTraversal, *GetOutputNode(), isOutputChainActive)} ***
This all works flawlessly if I take the recording piece out, or the offline render out, but not with both included.
