CODEWITHSUNDEEP
swiftavfoundation
Satsuki
Satsuki

Reputation: 2196

detect db using avfoundation

Hello I am trying to monitor the db. Recording is not my main purpose.I am using avfoundation to do this. Below is the code in which I am trying to print the db. However I am only getting -160dbfs. Is there something that I am missing? Thank you! 

   override func viewDidLoad() {
        super.viewDidLoad()
        recordingSession = AVAudioSession.sharedInstance()
        AVAudioSession.sharedInstance().requestRecordPermission { (hasPermission) in
            if hasPermission{
                print("Accpeted")
            }
        }
        let filename = getDocumentsDirectory().appendingPathComponent("recording.m4a")
        let settings = [AVFormatIDKey: Int(kAudioFormatMPEG4AAC), AVSampleRateKey:12000,AVNumberOfChannelsKey:1,AVEncoderAudioQualityKey:AVAudioQuality.high.rawValue]
        do{
            audioRecorder = try AVAudioRecorder(url: filename,settings:settings)
            audioRecorder.delegate = self
            audioRecorder.isMeteringEnabled = true
            timerOne()
        }catch{
            print("failed to initialize")
        }
        audioRecorder.record()
        print(audioRecorder.isRecording)
    }

    func timerOne() {
        timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(self.updateMonitorDb), userInfo: nil, repeats: true)
    }

    @objc func updateMonitorDb(){
        audioRecorder.updateMeters()
        let monitorDb = audioRecorder.averagePower(forChannel: 1)
        print(monitorDb)
    }

    func getDocumentsDirectory() -> URL {
        let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
        let documentsDirectory = paths[0]
        return documentsDirectory
    }

Upvotes: 1

Views: 243

Answers (1)

Valérian
Valérian

Reputation: 1118

You record only 1 channel and averagePower(forChannel:) is 0-based.

@objc func updateMonitorDb(){
    audioRecorder.updateMeters()
    let monitorDb = audioRecorder.averagePower(forChannel: 0)
    print(monitorDb)
}

Upvotes: 0

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