Recording audio in Swift

Question

Does anyone know where I can find info on how to record audio in a Swift application? I've been looking at some of the audio playback examples but I can't seem to be able to find anything on implementing the audio recording. Thanks

Answer 1

In Swift 3

• Add framework AVFoundation
• **In info.plist add key value

Key = Privacy - Microphone Usage Description and Value = For using microphone

(the apps will crash if you don't provide the value - description why you are asking for the permission)**

• Import AVFoundation & AVAudioRecorderDelegate, AVAudioPlayerDelegate

  import AVFoundation   class RecordVC: UIViewController , AVAudioRecorderDelegate, AVAudioPlayerDelegate 

• Create button for record audio & play audio , and label for display recording timing & give outlets and action as start_recording , play_recording & declare some variables which we will use later

  @IBOutlet var recordingTimeLabel: UILabel! @IBOutlet var record_btn_ref: UIButton! @IBOutlet var play_btn_ref: UIButton!  var audioRecorder: AVAudioRecorder! var audioPlayer : AVAudioPlayer! var meterTimer:Timer! var isAudioRecordingGranted: Bool! var isRecording = false var isPlaying = false 

• In viewDidLoad check record permission

  override func viewDidLoad() {     super.viewDidLoad()     check_record_permission() }  func check_record_permission() {     switch AVAudioSession.sharedInstance().recordPermission() {     case AVAudioSessionRecordPermission.granted:         isAudioRecordingGranted = true         break     case AVAudioSessionRecordPermission.denied:         isAudioRecordingGranted = false         break     case AVAudioSessionRecordPermission.undetermined:         AVAudioSession.sharedInstance().requestRecordPermission({ (allowed) in                 if allowed {                     self.isAudioRecordingGranted = true                 } else {                     self.isAudioRecordingGranted = false                 }         })         break     default:         break     } } 

• generate path where you want to save that recording as myRecording.m4a

  func getDocumentsDirectory() -> URL {     let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)     let documentsDirectory = paths[0]     return documentsDirectory }  func getFileUrl() -> URL {     let filename = "myRecording.m4a"     let filePath = getDocumentsDirectory().appendingPathComponent(filename) return filePath } 

• Setup the recorder

  func setup_recorder() {     if isAudioRecordingGranted     {         let session = AVAudioSession.sharedInstance()         do         {             try session.setCategory(AVAudioSessionCategoryPlayAndRecord, with: .defaultToSpeaker)             try session.setActive(true)             let settings = [                 AVFormatIDKey: Int(kAudioFormatMPEG4AAC),                 AVSampleRateKey: 44100,                 AVNumberOfChannelsKey: 2,                 AVEncoderAudioQualityKey:AVAudioQuality.high.rawValue             ]             audioRecorder = try AVAudioRecorder(url: getFileUrl(), settings: settings)             audioRecorder.delegate = self             audioRecorder.isMeteringEnabled = true             audioRecorder.prepareToRecord()         }         catch let error {             display_alert(msg_title: "Error", msg_desc: error.localizedDescription, action_title: "OK")         }     }     else     {         display_alert(msg_title: "Error", msg_desc: "Don't have access to use your microphone.", action_title: "OK")     } } 

• Start recording when button start_recording press & display seconds using updateAudioMeter, & if recording is start then finish the recording

  @IBAction func start_recording(_ sender: UIButton) {     if(isRecording)     {         finishAudioRecording(success: true)         record_btn_ref.setTitle("Record", for: .normal)         play_btn_ref.isEnabled = true         isRecording = false     }     else     {         setup_recorder()          audioRecorder.record()         meterTimer = Timer.scheduledTimer(timeInterval: 0.1, target:self, selector:#selector(self.updateAudioMeter(timer:)), userInfo:nil, repeats:true)         record_btn_ref.setTitle("Stop", for: .normal)         play_btn_ref.isEnabled = false         isRecording = true     } }  func updateAudioMeter(timer: Timer) {     if audioRecorder.isRecording     {         let hr = Int((audioRecorder.currentTime / 60) / 60)         let min = Int(audioRecorder.currentTime / 60)         let sec = Int(audioRecorder.currentTime.truncatingRemainder(dividingBy: 60))         let totalTimeString = String(format: "%02d:%02d:%02d", hr, min, sec)         recordingTimeLabel.text = totalTimeString         audioRecorder.updateMeters()     } }  func finishAudioRecording(success: Bool) {     if success     {         audioRecorder.stop()         audioRecorder = nil         meterTimer.invalidate()         print("recorded successfully.")     }     else     {         display_alert(msg_title: "Error", msg_desc: "Recording failed.", action_title: "OK")     } } 

• Play the recording

  func prepare_play() {     do     {         audioPlayer = try AVAudioPlayer(contentsOf: getFileUrl())         audioPlayer.delegate = self         audioPlayer.prepareToPlay()     }     catch{         print("Error")     } }  @IBAction func play_recording(_ sender: Any) {     if(isPlaying)     {         audioPlayer.stop()         record_btn_ref.isEnabled = true         play_btn_ref.setTitle("Play", for: .normal)         isPlaying = false     }     else     {         if FileManager.default.fileExists(atPath: getFileUrl().path)         {             record_btn_ref.isEnabled = false             play_btn_ref.setTitle("pause", for: .normal)             prepare_play()             audioPlayer.play()             isPlaying = true         }         else         {             display_alert(msg_title: "Error", msg_desc: "Audio file is missing.", action_title: "OK")         }     } } 

• When recording is finish enable the play button & when play is finish enable the record button

  func audioRecorderDidFinishRecording(_ recorder: AVAudioRecorder, successfully flag: Bool) {     if !flag     {         finishAudioRecording(success: false)     }     play_btn_ref.isEnabled = true }  func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool) {     record_btn_ref.isEnabled = true } 

• Generalize function for display alert

  func display_alert(msg_title : String , msg_desc : String ,action_title : String) {     let ac = UIAlertController(title: msg_title, message: msg_desc, preferredStyle: .alert)     ac.addAction(UIAlertAction(title: action_title, style: .default)     {         (result : UIAlertAction) -> Void in     _ = self.navigationController?.popViewController(animated: true)     })     present(ac, animated: true) }