I can successfully record and write files but every now and then (around 10% of the times) it fails and the file ends up with 0 seconds length. It doesn't throw an error anywhere, just the file is empty.

I'm happy to help and even submit a PR but I'm a bit stuck and I don't really know where to move on.

Hello sir,

I am getting below error while recording audio in foreground

Error: required condition is false: [AVAudioIONodeImpl.mm:1064:SetOutputFormat: (format.sampleRate == hwFormat.sampleRate)]

Xcode :11.4.1 Language swift 4.2 MacOS: Catalina version 10.15.5 Iphone : 8plus iphone Os: 13.3.1

Below is my code:

File name: RecorderViewContrlloer

let settings = [AVFormatIDKey: kAudioFormatLinearPCM, AVLinearPCMBitDepthKey: 16, AVLinearPCMIsFloatKey: true, AVSampleRateKey: Float(16000.0), AVNumberOfChannelsKey: 1] as [String : Any]

    self.recordingTs = NSDate().timeIntervalSince1970
    self.silenceTs = 0
    do {
        let session = AVAudioSession.sharedInstance()
        try session.setCategory(.playAndRecord, mode: .default)
        try session.setActive(true)
    } catch let error as NSError {
        print(error.localizedDescription)
        return
    }
    let inputNode = self.audioEngine.inputNode
    guard let format = self.format() else {
        return
    }

// let format = inputNode.inputFormat(forBus: 0)

    inputNode.installTap(onBus: 0, bufferSize: 512, format: format) { (buffer, time) in
        
        let level: Float = -50
        let length: UInt32 = 1024
        buffer.frameLength = length
        let channels = UnsafeBufferPointer(start: buffer.floatChannelData, count: Int(buffer.format.channelCount))
        var value: Float = 0
        vDSP_meamgv(channels[0], 1, &value, vDSP_Length(length))
        var average: Float = ((value == 0) ? -100 : 20.0 * log10f(value))
        if average > 0 {
            average = 0
        } else if average < -100 {
            average = -100
        }
        let silent = average < level
        print(self.audioEngine.manualRenderingSampleTime)
        let ts = NSDate().timeIntervalSince1970
        self.totLTs = ts
        if ts - self.renderTs > 0.1 {
            let floats = UnsafeBufferPointer(start: channels[0], count: Int(buffer.frameLength))
            let frame = floats.map({ (f) -> Int in
                return Int(f * Float(Int16.max))
            })
            DispatchQueue.main.async
                {
                    self.renderTs = ts
                    let len = self.audioView.waveforms.count
                    for i in 0 ..< len {
                        let idx = ((frame.count - 1) * i) / len
                        let f: Float = sqrt(1.5 * abs(Float(frame[idx])) / Float(Int16.max))
                        self.audioView.waveforms[i] = min(49, Int(f * 50))
                    }
                    self.audioView.active = !silent
                    self.audioView.setNeedsDisplay()
            }
        }
        
        let write = true
        if write {
            if self.audioFile == nil {
                self.audioFile = self.createAudioRecordFile()
            }
            if let f = self.audioFile {
                do {
                    try f.write(from: buffer)
                } catch let error as NSError {
                    print(error.localizedDescription)
                }
            }
        }
    }
    do {
        recorder = try AVAudioRecorder(url: self.fileUrl(), settings: settings)
        recorder?.delegate = self
        recorder?.isMeteringEnabled = true
        recorder?.prepareToRecord()
        self.audioEngine.prepare()
        try self.audioEngine.start()
    } catch let error as NSError {
        print(error.localizedDescription)
        return
    }
    self.updateUI(.recording)
}

Above is my code of recording. Application is crash on inputNode.installTap(onBus: 0, bufferSize: 512, format: format) { (buffer, time) in

And give error like above mention

We have to deploy the application so please suggest and guide us for this issue

Look forward to hearing from you soon.. Regards Akash

Does it work only if AVFormatIDKey = kAudioFormatLinearPCM and file format ".wav" ? I tried changing to kAudioFormatAppleLossless and ".m4a" format and its not working.

While recording I'm able to see the waves, but there is no change in the waves according to voice. Its static always. Please correct me if I'm wrong anywhere.