User Profile

Hi, I'm trying to create a multitrack audio Player with AVAudioEngine in SwiftUI. It's basically 4 individual tracks (drums, bass, keys, click) playing at the same time. I've tried to build it using documentation I've found on google, but I'm running into the following error: "Terminating app due to uncaught exception 'com.apple.coreaudio.avfaudio', reason: 'required condition is false: [_nodes containsObject: node1] && [_nodes containsObject: node2]'" - can you please help me?As I'm new to coding, don't hesitate to let me know would be able to play sound.import SwiftUI import AVFoundation class AudioMixer { let engine = AVAudioEngine() let player = AVAudioPlayer() let drumPlayer = AVAudioPlayerNode() let bassPlayer = AVAudioPlayerNode() let keysPlayer = AVAudioPlayerNode() let clickPlayer = AVAudioPlayerNode() let mixer = AVAudioMixerNode() init() { let audioSession = AVAudioSession.sharedInstance() do { try audioSession.setCategory(AVAudioSession.Category.playback, options: .mixWithOthers) try audioSession.setActive(true) } catch { print(error.localizedDescription) } if let drumAudioPath = Bundle.main.path(forResource: "Drums1", ofType: "mp3") { let drumsAudioUrl = URL(fileURLWithPath: drumAudioPath) let drumsAudioFile = try? AVAudioFile(forReading: drumsAudioUrl) engine.connect(drumPlayer, to: mixer, format: drumsAudioFile?.processingFormat) drumPlayer.scheduleFile(drumsAudioFile!, at: nil, completionHandler: nil) } drumPlayer.play() engine.attach(drumPlayer) if let bassAudioPath = Bundle.main.path(forResource: "Bass1", ofType: "mp3") { let bassAudioUrl = URL(fileURLWithPath: bassAudioPath) let bassAudioFile = try? AVAudioFile(forReading: bassAudioUrl) engine.connect(bassPlayer, to: mixer, format: bassAudioFile?.processingFormat) bassPlayer.scheduleFile(bassAudioFile!, at: nil, completionHandler: nil) } bassPlayer.play() engine.attach(bassPlayer) if let keysAudioPath = Bundle.main.path(forResource: "Keys1", ofType: "mp3") { let keysAudioUrl = URL(fileURLWithPath: keysAudioPath) let keysAudioFile = try? AVAudioFile(forReading: keysAudioUrl) engine.connect(keysPlayer, to: mixer, format: keysAudioFile?.processingFormat) keysPlayer.scheduleFile(keysAudioFile!, at: nil, completionHandler: nil) } keysPlayer.play() engine.attach(keysPlayer) if let clickAudioPath = Bundle.main.path(forResource: "Click1", ofType: "mp3") { let clickAudioUrl = URL(fileURLWithPath: clickAudioPath) let clickAudioFile = try? AVAudioFile(forReading: clickAudioUrl) engine.connect(clickPlayer, to: mixer, format: clickAudioFile?.processingFormat) clickPlayer.scheduleFile(clickAudioFile!, at: nil, completionHandler: nil) } clickPlayer.play() engine.attach(clickPlayer) engine.attach(mixer) engine.prepare() do { try engine.start() } catch { print(error.localizedDescription) } }