I have following the cookbook Miniapp/Recorder sample to create an audioKit recorder but can not record...

[moomoo]

macOS Version(s) Used to Build

macOS 13 Ventura

Xcode Version(s)

Xcode 14

Description

Xcode 15, IOS 17,
Development environment: Mac os 14.5.
I am trying to learn to use AudioKit and AudioKitUI, at first to make a small audio recorder and audio memo.
And I followed the Miniapp/Recorder to write a test app recorder, and save audio file. But the caf file is 4k and is empty!
Is there any issue with the AudioKit.NodeRecorder?
The following is part of the code:

struct RecorderData {
    var isRecording = false
//    var isPlaying = false
}

class RecorderConductor: ObservableObject, HasAudioEngine {
    let engine = AudioEngine()
    var recorder: NodeRecorder?
    let player = AudioPlayer()
    var silencer: Fader?
    var tappableNodeA : Fader
//    var tappableNodeB : Fader
    let mixer = Mixer()
    
    
    @Published var data = RecorderData() {
        didSet {
            if data.isRecording {
                do {
                    try recorder?.record()
                  
                } catch let err {
                    print(err)
                }
            } else {
                var file = recorder?.audioFile
                recorder?.stop()
                recorder?.closeFile(file: &file)
            }

//            if data.isPlaying {
//                if let file = recorder?.audioFile {
//                    try? player.load(file: file)
//                    player.play()
//                }
//            } else {
//                player.stop()
//            }
        }
    }

    init() {
#if os(iOS)
    do {
        
        AudioKit.Settings.bufferLength = .short
        try AVAudioSession.sharedInstance().setPreferredIOBufferDuration(AudioKit.Settings.bufferLength.duration)
        try AVAudioSession.sharedInstance().setCategory(.playAndRecord,
                                                        options: [.defaultToSpeaker, .mixWithOthers, .allowBluetoothA2DP])
        try AVAudioSession.sharedInstance().setActive(true)
    } catch let err {
        print(err)
    }
#endif
        
        print("RecorderConductor init")
        guard let input = engine.input else {
            fatalError()
        }

        
        do {
            recorder = try NodeRecorder(node: input, fileDirectoryURL: FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0], shouldCleanupRecordings: false)
        } catch let err {
            fatalError("\(err)")
        }

        tappableNodeA = Fader(input, gain: 10)
        silencer = Fader(tappableNodeA, gain: 0)
        engine.output = silencer
    }
    
    deinit {
        print("RecorderConductor deinit")
    }
}
struct AudioRecordView : View {
    @Environment(\.modelContext) private var modelContext
    @StateObject var recorderConductor = RecorderConductor()
    
    var body: some View {
        
        VStack {
           Text("Record Audio")
//            NodeRollingView(recorderConductor.tappableNodeA).clipped()
            NodeOutputView(recorderConductor.tappableNodeA).clipped()
            Spacer()
            
            HStack {
                Button(){
                    recorderConductor.data.isRecording.toggle()
                    if recorderConductor.data.isRecording {
                        print("Start recording")
                        let url = recorderConductor.recorder?.audioFile?.url
                        print("fileurl: \(url?.absoluteString ?? "no url") ")
                        let newItem = Item(url: url!, UUID: UUID())
                        
                        modelContext.insert(newItem)
                    } else {
                        print("Pause recording")
                    }
                } label: {
                    Image(
                        systemName: recorderConductor.data.isRecording ? "stop.circle.fill" : "record.circle.fill"   )
                        .resizable()
                       .aspectRatio(contentMode: .fit)
                       .frame(width: 50, height: 50)
                       .foregroundColor(Color.red)
                       
                }
                
                Button() {
                    print("Stop recording")
                } label: {
                    Image(systemName: "stop.circle.fill")
                        .resizable()
                       .aspectRatio(contentMode: .fit)
                       .frame(width: 50, height: 50)
                       .foregroundColor(Color.black)
                }
            }
            
        }
        .navigationTitle("Record Audio")
        .onAppear(){
            print("AudioRecordView appeared")
            recorderConductor.start()
        }
        .onDisappear(){
            print("AudioRecordView disappeared")
            recorderConductor.stop()
        }
    }
}

Crash Logs, Screenshots or Other Attachments (if applicable)

No response

[Nick Culbertson]

If you remove this code it executes properly:

if recorderConductor.data.isRecording {
                        print("Start recording")
                        let url = recorderConductor.recorder?.audioFile?.url
                        print("fileurl: \(url?.absoluteString ?? "no url") ")
                        let newItem = Item(url: url!, UUID: UUID())
                        
                        modelContext.insert(newItem)
                    } else {
                        print("Pause recording")
                    }

It looks like accessing recorderConductor.recorder?.audioFile?.url while you are recording is causing an issue.

[moomoo]

Thank you so much. The reason is that the NodeRecorder.audioFile explicitly close the file in the method.
The AudioKit.NodeRecorder has so limited features.
In NodeRecorder, I can not specify the AudioFormat for recording, can not specify the file extension...
it seems better to use AVaudioEngine, AVFundation directly, it is quite flexible

[Nick Culbertson]

Because of the limitations you described, I think NodeRecorder is best used as an example starting point to create your own Recorder class. That's how I use it.