AVAudioengine play / loop audio , multiple buttons

Question

I have this button to play and loop a wav. But what if I have a second button with another loop? I want this second loop to start playing once pressed, however, the first loop must finish his 'round'. And vice versa (play and loop the second loop, press button first loop and it takes over)

 @IBAction func playButtonTapped(_ sender: Any) {



    guard let filePath: String = Bundle.main.path(forResource: "25loop110", ofType: "wav") else{ return }
          print("\(filePath)")
          let fileURL: URL = URL(fileURLWithPath: filePath)
          guard




              let audioFile = try? AVAudioFile(forReading: fileURL) else{ return }

          let audioFormat = audioFile.processingFormat
          let audioFrameCount = UInt32(audioFile.length)
          guard let audioFileBuffer = AVAudioPCMBuffer(pcmFormat: audioFormat, frameCapacity: audioFrameCount)  else{ return }
          do{
              try audioFile.read(into: audioFileBuffer)

              timeShift.rate = adjustedBpm/bpm
              playerNode.scheduleFile(audioFile, at: nil, completionHandler: nil)


          } catch{
              print("over")
          }

          try? audioEngine.start()
          playerNode.play()
          playerNode.scheduleBuffer(audioFileBuffer, at: nil, options:.loops,completionHandler: nil)

    }

Robin Schmidt · Accepted Answer · 2020-02-09T14:59:30.557

1

You can handle this behavior by using the completionHandler parameter of .scheduleBuffer.

For example, you could do something like this:

var nextAudioFilePath: String  
var isPlaying: Bool = false

@IBAction func playLoopA() {  
   guard let path = Bundle.main.path(forResource: "audioFileA", ofType: "wav") else { return }  
   nextAudioFilePath = path  
   guard !isPlaying else { return }  
   play()
}  

@IBAction func playLoopB() {  
   guard let path = Bundle.main.path(forResource: "audioFileB", ofType: "wav") else { return }  
   nextAudioFilePath = path  
   guard !isPlaying else { return }  
   play()
}  

private func play() {  
   let fileURL = URL(fileURLWithPath: nextAudioFilePath)  
   ...  
   playerNode.scheduleBuffer(audioFileBuffer, at: nil, options: [], completionHandler: { [weak self] in   
      self?.play()
   })
}

edited Feb 09 '20 at 14:59

answered Feb 09 '20 at 14:25

Robin Schmidt

1,153
8
15

Thx Robin, I will look into this!! – user1737746 Feb 09 '20 at 14:30
could you maybe explain where I can put different wav url's in this case? – user1737746 Feb 09 '20 at 14:57
Your welcome :-) keep in mind to accept the answer if it solved your problem ;-) – Robin Schmidt Feb 09 '20 at 15:08
I have one last question if you don't mind. This is wrong, but I don't know how to change it: – user1737746 Feb 09 '20 at 15:18
private func play() { guard let filePath: String = Bundle.main.path(forResource: "25loop110", ofType: "wav") else{ return } print("\(filePath)") let fileURL = URL(fileURLWithPath: nextAudioFilePath) guard let audioFile = try? AVAudioFile(forReading: fileURL) else{ return } – user1737746 Feb 09 '20 at 15:18
You need to remove first line `guard let filePath: String = Bundle.main.path(forResource: "25loop110", ofType: "wav") else{ return }`, because filePath is now set from outside. But what exactly is wrong? – Robin Schmidt Feb 09 '20 at 15:21
ah ok, I will check this and see what happens. – user1737746 Feb 09 '20 at 15:22
1

Ah, great!! You really saved my day. Thnx Robin!! – user1737746 Feb 09 '20 at 15:27

score 0 · Answer 2 · answered Feb 09 '20 at 18:58

0

I also found this solution:

playerNode.scheduleBuffer(audioFileBuffer, at: nil, options:[.interruptsAtLoop, .loops],completionHandler: nil)

answered Feb 09 '20 at 18:58

user1737746

101
10

AVAudioengine play / loop audio , multiple buttons

2 Answers2