当我从互联网上加载视频（10-40MB大）时，无法提供流畅的播放体验。

我的AVPlayer要么加载整个视频然后播放，要么播放1s，缓冲然后停止播放。

我尝试了无尽的库，缓冲区观察者方法和教程。似乎没有任何帮助。

    .
    .
    .

    self.makeLoaderVisible()

    let playerItem = AVPlayerItem(url: url)
    playerItem.addObserver(self, forKeyPath: "playbackBufferEmpty", options: .new, context: nil)
    playerItem.addObserver(self, forKeyPath: "playbackLikelyToKeepUp", options: .new, context: nil)
    playerItem.addObserver(self, forKeyPath: "playbackBufferFull", options: .new, context: nil)

    avPlayer?.replaceCurrentItem(with: playerItem)
    avPlayer?.automaticallyWaitsToMinimizeStalling = false
    avPlayer?.playImmediately(atRate: 0)
//  avPlayer?.play()

    }


override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
    if object is AVPlayerItem {
        switch keyPath! {
        case "playbackBufferEmpty":
            // Show loader
            makeLoaderVisible()

        case "playbackLikelyToKeepUp":
            // Hide loader
            hideLoader()

        case "playbackBufferFull":
            // Hide loader
            hideLoader()

        default:
            return
        }
    }
}