Swift 5 loading multiple AVAudioPlayers causes too many open files error - ios

Question

I have an app with around 10 ViewControllers all connected to a single tab bar. In most of the ViewControllers, there are multiple buttons which cause a different local sound file to be played. Everything in all of the ViewControllers work fine independently. Sound files play fine. There are around 20 to 70 sound files initalised and loaded for each of the ViewControllers, so if the user cycles through all 10 controllers, the app could potentially load around 500 sound files and never unload them. I am thinking of added more tabs, so this is proving to be a problem.
My code (simplified) is as follows, for each ViewControllers:
class TrickyWordsViewController: UIViewController {
var musicEffect_hello: AVAudioPlayer = AVAudioPlayer()
// another 50 lines ...
var musicEffect_bye: AVAudioPlayer = AVAudioPlayer()
override func viewDidLoad() {
let musicFile_she = Bundle.main.path(forResource: "hello", ofType: ".m4a")
do {
try musicEffect_hello = AVAudioPlayer(contentsOf: URL (fileURLWithPath: musicFile_hello!))
}
catch { print(error) }
}
#IBAction func playSound(_ sender: Any) {
musicEffect_hello.play()
}
}
However, as the user clicks through many ViewControllers, the app usually crashes on the
try musicEffect_sound = AVAudioPlayer(...
line, with the following messages:
Error Domain=NSOSStatusErrorDomain Code=-42 "(null)"
Failed to open audio settings path fd. Error: (24) Too many open files
It looks like the app has loaded too many files.
a) Should I move the initialisation of all the sound files from viewDidLoad() into the playSound()? Sound files would only get initialised and loaded when the button is pressed. The theory is, every sound file is created on demand, within the IBAction function, played, and then destroyed when the IBAction function goes out of scope. I have between 20 and 70 sound files in each ViewControllers. Each sound file is only a few seconds long, and between 10KB and 150KB in size. Would this impact performance, and lag on playing each sound?
b) Should I count the number of sound files I load in the app, as the user clicks through the tab bar into each ViewControllers, and if the number of sound files exceeds a specific number, which seems to be 300-ish sound files, I would start to unload previous sound files? If so, how do I un-load sound files loaded in another ViewControllers?
c) Should I un-load sound files after the user navigates to another ViewControllers? If so, is there a function I can override when a user presses on another tab bar icon? viewDidDisappear() and viewWillDisappear() doesn't seem to be called when using tab bar.
d) Should I handle the memory warning called? I did try:
override func didReceiveMemoryWarning() {
print("didReceiveMemoryWarning...")
super.didReceiveMemoryWarning()
}
but that didn't seem to be called, or do anything.
Any ideas?

Answer 1

Maybe you don't setting the bundle properly.
If you set Bundle, you shouldn't set url path. Because its in your bundle. Simple
May you should try something like this:
func playSound() {
guard let url = Bundle.main.url(forResource: "hello", withExtension: "m4a") else { return }
do {
try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default)
try AVAudioSession.sharedInstance().setActive(true)
/* iOS 11. */
player = try AVAudioPlayer(contentsOf: url, fileTypeHint: AVFileType.mp3.rawValue)
/* iOS 10 :
player = try AVAudioPlayer(contentsOf: url, fileTypeHint: AVFileTypeMPEGLayer3) */
guard let player = player else { return }
player.play()
} catch let error {
print(error.localizedDescription)
}
}
I really hope I helped you =D