AVPlayer keeps adding streams instead of replacing - ios

Question

I am triggering a video play from a URL. It's just a button, opening the AVPlayerController full screen. If people close it, the can go back to the another item, with possibly a video. There they can click that video to start, however, when they do so, I can hear the audio of the previous player, of the other VC playing in the together with this one. This keeps layering up. How can I avoid this?
This is my class for the videoplayer
import UIKit
import AVFoundation
import AVKit
class simpleVideoPlayer: UIViewController {
var playerController = AVPlayerViewController()
var player:AVPlayer?
var inputVideoUrl: String? = nil
func setupVideo() {
self.player = AVPlayer()
self.playerController.player = self.player
}
func playNext(url: URL) {
let playerItem = AVPlayerItem.init(url: url)
self.playerController.player?.replaceCurrentItem(with: playerItem)
self.playerController.player?.play()
}
func setupVideoUrl(url: String) {
inputVideoUrl = url
}
}
This is in my viewcontroller. It's first getting a URL of a possible advert from my server, if that failed, then it wil just load the "default" video.
let SimpleVideo = simpleVideoPlayer()
#objc func handleTap(gestureRecognizer: UIGestureRecognizer)
{
ApiVideoAdvertService.sharedInstance.fetchVideoAdvert { (completion: VideoAdvert) in
let advertUrl = URL(string: completion.video_adverts_url)
var url = URL(string: (self.article?.video_link?.files[0].link_secure)!)
var showAdvert: Bool = false
if (advertUrl != nil && UIApplication.shared.canOpenURL(advertUrl!)) {
url = advertUrl
showAdvert = true
}
let appDelegate = UIApplication.shared.delegate as! AppDelegate
if (showAdvert) {
NotificationCenter.default.addObserver(self, selector: #selector(self.finishVideo),
name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: self.SimpleVideo.playerController.player?.currentItem)
}
appDelegate.window?.rootViewController?.present(self.SimpleVideo.playerController, animated: true, completion: {
self.SimpleVideo.setupVideo()
if (showAdvert) {
self.SimpleVideo.playerController.setValue(true, forKey: "requiresLinearPlayback")
}
self.SimpleVideo.playNext(url: url!)
})
}
#objc func finishVideo() {
let url = URL(string: (article?.video_link?.files[0].link_secure)!)
SimpleVideo.playerController.setValue(false, forKey: "requiresLinearPlayback")
SimpleVideo.playNext(url: url!)
}

Answer 1

Removing the observer inside finishVideo did it.
#objc func finishVideo() {
NotificationCenter.default.removeObserver(self)
let url = URL(string: (article?.video_link?.files[0].link_secure)!)
SimpleVideo.playerController.setValue(false, forKey: "requiresLinearPlayback")
SimpleVideo.playNext(url: url!)
}