未使用AVPLayer播放视频

Question

我使用AVPlayer从URL播放视频。下面我使用的代码：

@implementation VideoPlayerController  {
    IBOutlet UIWebView* webView;
}

-(void)viewDidLoad {
    [super viewDidLoad];

    self.navigationController.navigationBar.tintColor = [UIColor whiteColor];

    NSString* urlString = [NSString stringWithFormat:@"%@", self.videoUrl];
    NSURL *videoURL = [NSURL URLWithString:urlString];
    [self startPlaybackForItemWithURL:videoURL];

}

-(void)startPlaybackForItemWithURL:(NSURL*)url {

    // First create an AVPlayer
    AVPlayer *player = [AVPlayer playerWithURL:url];
    self.player = player;
    // Begin playback
    [player play];

}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:YES];

    [[UIDevice currentDevice] setValue:
     [NSNumber numberWithInteger: UIInterfaceOrientationPortrait]
                                forKey:@"orientation"];
    [self.player pause];

}

@end

因此，在iOS 12设备上，视频加载时间很长，但是在播放之后……但是在某些设备上（在iOS 11.4，iPhone 7 32 Gb上）则存在一些错误：

Task <7813A625-BBCF-4486-BC48-D6B066129F41>.<2> finished with error - code: -999
Task <37ED66A3-0404-414D-969E-CB5E118BDE4B>.<1> finished with error - code: -999
TIC Read Status [40:0x0]: 1:57
Task <37ED66A3-0404-414D-969E-CB5E118BDE4B>.<1> HTTP load failed (error code: 12 [1:12])

我必须使用媒体服务器播放视频的示例为here

我需要代码帮助，或者视频播放不好。

谢谢！