Why AVPlayer downloading first instead live streaming?

问题

First time I am working with AVPlayer and I want to play a mp3 file using HTTP request with live streaming. I use AVPlayer that is working fine to play mp3 files, but the problem is AVPlayer needs to download the mp3 first then play it. I don't know why AVPlayer downloads the file and then play it instead of live playing. My Xcode 8.2.1 and I am using Swift 3.

Here is my code snippet.

var audioPlayer = AVPlayer()
var avplayerItem : AVPlayerItem?

override func viewDidLoad() {
    super.viewDidLoad()

    let fileurl:URL = URL(string : "http://www.noiseaddicts.com/samples_1w72b820/2514.mp3")!
    avplayerItem = AVPlayerItem(url : fileurl)
    audioPlayer = AVPlayer(playerItem : avplayerItem)
    audioPlayer.rate = 1.0
    audioPlayer.play()
}

In case of AVPlayer requires to download the whole file before playing it, what should I do for audio live streaming?

Thanks.

来源：https://stackoverflow.com/questions/41542841/why-avplayer-downloading-first-instead-live-streaming