Swift AVPlayer无法播放没有扩展名的视频url

我从服务器上得到一个视频URL，如下所示：

这是我的代码：

        let mimeType = "video/mp4; codecs=\"avc1.42E01E, mp4a.40.2\""
        let asset = AVURLAsset(url: url, options:["AVURLAssetOutOfBandMIMETypeKey": mimeType])
        let playerItem = AVPlayerItem(asset: asset)
        avPlayer = AVPlayer(playerItem: playerItem)
        avPlayerViewConroller.player = avPlayer
        avPlayerViewConroller.view.frame = cell.qualityImgView.frame
        
        cell.qualityImgView.addSubview(avPlayerViewConroller.view)
        self.addChild(avPlayerViewConroller)
        
        playerItem.addObserver(self, forKeyPath: "status", options: NSKeyValueObservingOptions(), context: nil)


        override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?)
        {
           if(avPlayer.currentItem?.status == AVPlayerItem.Status.readyToPlay) {
             avPlayerViewConroller.player!.play()
           }
        }

通过浏览器，我可以下载视频，但无法播放视频或获取拇指：

        func getThumbnailImage(forUrl url: URL) -> UIImage? {
                let asset: AVAsset = AVAsset(url: url)
                let imageGenerator = AVAssetImageGenerator(asset: asset)

                do {
                    let thumbnailImage = try imageGenerator.copyCGImage(at: CMTimeMake(value: 1, timescale: 60) , actualTime: nil)
                    return UIImage(cgImage: thumbnailImage)
                } catch let error {
                    print(error)
                }

                return nil
            }

有什么解决办法吗

谢谢