How to play multiple Audio Files simultaneously using AVPlayer?

Question

I am trying to play multiple audio files using 2 AVPlayer instances, but one of the player stops for a fraction of a second rather than playing all audio files simultaneousl

Answer 1

You would be better off using AVAudioPlayerNode, AVAudioMixerNode, AVAudioEngine. Using these classes you won't have problems like you have right now. It's also not that difficult to set up.

You can check out my gist, in order to play the sounds in your Playgrounds you would need to put audio files into Resources folder in Project Navigator: https://gist.github.com/standinga/24342d23acfe70dc08cbcc994895f32b

The code works without stopping background audio when top sounds are triggered.

Here's also the same code:

import AVFoundation
import PlaygroundSupport

PlaygroundPage.current.needsIndefiniteExecution = true

class AudioPlayer {
var backgroundAudioFile:AVAudioFile
var topAudioFiles: [AVAudioFile] = []
var engine:AVAudioEngine
var backgroundAudioNode: AVAudioPlayerNode
var topAudioAudioNodes = [AVAudioPlayerNode]()
var mixer: AVAudioMixerNode
var timer: Timer!
var urls: [URL] = []

init (_ url: URL, urls: [URL] = []) {
    backgroundAudioFile = try! AVAudioFile(forReading: url)
    topAudioFiles = urls.map { try! AVAudioFile(forReading: $0) }

    engine = AVAudioEngine()
    mixer = AVAudioMixerNode()

    engine.attach(mixer)
    engine.connect(mixer, to: engine.outputNode, format: nil)
    self.urls = urls
    backgroundAudioNode = AVAudioPlayerNode()
    for _ in topAudioFiles {
        topAudioAudioNodes += [AVAudioPlayerNode()]
    }
}

func start() {
    engine.attach(backgroundAudioNode)
    engine.connect(backgroundAudioNode, to: mixer, format: nil)
    backgroundAudioNode.scheduleFile(backgroundAudioFile, at: nil, completionHandler: nil)

    try! engine.start()
    backgroundAudioNode.play()

    for node in topAudioAudioNodes {
        engine.attach(node)
        engine.connect(node, to: mixer, format: nil)
        try! engine.start()
    }
// simulate rescheduling files played on top of background audio
    DispatchQueue.global().async { [unowned self] in
        for i in 0..<1000 {
        sleep(2)
        let index = i % self.topAudioAudioNodes.count
        let node = self.topAudioAudioNodes[index]
        node.scheduleFile(self.topAudioFiles[index], at: nil, completionHandler: nil)
        node.play()
        }
    }
    }
}

let bundle = Bundle.main
let beepLow = bundle.url(forResource: "beeplow", withExtension: "wav")!
let beepMid = bundle.url(forResource: "beepmid", withExtension: "wav")!
let backgroundAudio = bundle.url(forResource: "backgroundAudio", withExtension: "wav")!
let audioPlayer = AudioPlayer(backgroundAudio, urls: [beepLow, beepMid])
audioPlayer.start()