ios - 下载文件导致在 ios 中流式传输的问题

Question

我在我的应用程序中使用 AVPlayer 进行实时流式传输并且工作正常。

但是当我尝试使用 Alamofire.downlaod 方法 下载一些文件时，流停止工作。

AVPlayer 的rate 属性自动为零。

我认为线程可能存在一些问题，但我不明白。

我的代码如下

override func viewDidLoad() {

    play_Live_Stream()
}


override func viewWillAppear() {

    Download_favourite_files()
}

func Download_favourite_files() {
    for int i in arr_favourites{
        Alamofire.download(urlString, to: destination).response { response in
            print(response)
        }
    }
    
}

func play_Live_Stream(){
    myplayerItem = AVPlayerItem(url: url as! URL)
    myPlayer = AVPlayer(playerItem: myplayerItem)
    myPlayer.volume = volume_slider.value
    PlayerObserving = true
    NotificationCenter.default.addObserver(self, selector: #selector(playInstalled(noti:)), name: NSNotification.Name.AVPlayerItemPlaybackStalled, object: myPlayer.currentItem)
    NotificationCenter.default.addObserver(self, selector: #selector(playfailed(noti:)), name: NSNotification.Name.AVPlayerItemFailedToPlayToEndTime, object: myPlayer.currentItem)
    myPlayer.currentItem?.addObserver(self, forKeyPath: "status", options: NSKeyValueObservingOptions.new, context: nil)
    myPlayer.currentItem?.addObserver(self, forKeyPath: "timedMetadata", options: [.new,.old,.initial], context: nil)
    myPlayer.currentItem?.addObserver(self, forKeyPath: "playbackLikelyToKeepUp", options: .new, context: nil)

}

override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
        
    if ((object! as AnyObject).isEqual(myPlayer.currentItem) && keyPath=="status"){
        if myPlayer.status == AVPlayerStatus.readyToPlay{
            print("ReadyToPlay")
          
            myPlayer.play()
        }
    }
}

尝试 2(默认 NSURLSession)

func load_downloads(){
    for track in arr_tracks{
                
        let urlString = BASE_URL + "/track/download/" + "\(track.id)"
        print("downloaded url",urlString)
        let url = NSURL(string: urlString)
        let downloadTask = backgroundSession.downloadTask(with: url as! URL)
        downloadTask.resume()
    }
}


func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
        
    let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
    let destinationURLForFile = documentsURL.appendingPathComponent((downloadTask.originalRequest?.url?.lastPathComponent)! + "_" + (downloadTask.response?.suggestedFilename)!)
    
    let fileManager = FileManager()
    
    if fileManager.fileExists(atPath: destinationURLForFile.path){
    }
    else{
        do {
            try fileManager.moveItem(at: location as URL, to: destinationURLForFile as URL)
        }catch{
            print("An error occurred while moving file to destination url")
        }
    }
    
}

但它没有给我任何关于为什么流停止的信息。如果有的话，我还会观察 Stalled & failed 信息。

Answer 1

尝试在主线程上播放流。

DispatchQueue.main.async { [unowned self]
 self.play_Live_Stream()
}