最后重播 AVQueuePlayer 中的项目

Question

I need to create something like an infinite loop in my AVQueuePlayer . Especially, I want to replay the whole NSArray of AVPlayerItem s once the last component finishes playing.

I must admit that I actually do not have any idea how to achieve this and hope you can give me some clues.

Answer 1

best way to loop a sequence of videos in AVQueuePlayer.

observe for each playeritem in AVQueuePlayer.

queuePlayer.actionAtItemEnd = AVPlayerActionAtItemEndNone;
for(AVPlayerItem *item in items) {
    [[NSNotificationCenter defaultCenter] addObserver:self 
            selector:@selector(nextVideo:) 
            name:AVPlayerItemDidPlayToEndTimeNotification 
            object:item ];
}

on each nextVideo insert the currentItem again to queue it for playback. make sure to seek to zero for each item. after advanceToNextItem the AVQueuePlayer will remove the currentItem from queue.

-(void) nextVideo:(NSNotification*)notif {
    AVPlayerItem *currItem = notif.userInfo[@"object"];
    [currItem seekToTime:kCMTimeZero];
    [queuePlayer advanceToNextItem];
    [queuePlayer insertItem:currItem afterItem:nil];
}

Answer 2

This is it pretty much from scratch. The components are:

1. Create a queue that is an NSArray of AVPlayerItems.
2. As each item is added to the queue, set up a NSNotificationCenter observer to wake up when the video reaches the end.
3. In the observer's selector, tell the AVPlayerItem that you want to loop to go back the the beginning, then tell the player to play.

(NOTE: The AVPlayerDemoPlaybackView comes from the Apple "AVPlayerDemo" sample. Simply a subclass of UIView with a setter)

BOOL videoShouldLoop = YES;
NSFileManager *fileManager = [NSFileManager defaultManager];
NSMutableArray *videoQueue = [[NSMutableArray alloc] init];
AVQueuePlayer *mPlayer;
AVPlayerDemoPlaybackView *mPlaybackView;

// You'll need to get an array of the files you want to queue as NSARrray *fileList:
for (NSString *videoPath in fileList) {
    // Add all files to the queue as AVPlayerItems
    if ([fileManager fileExistsAtPath: videoPath]) {
        NSURL *videoURL = [NSURL fileURLWithPath: videoPath];
        AVPlayerItem *playerItem = [AVPlayerItem playerItemWithURL: videoURL];
        // Setup the observer
        [[NSNotificationCenter defaultCenter] addObserver: self
                                                 selector: @selector(playerItemDidReachEnd:)
                                                     name: AVPlayerItemDidPlayToEndTimeNotification
                                                   object: playerItem];
        // Add the playerItem to the queue
        [videoQueue addObject: playerItem];
    }
}
// Add the queue array to the AVQueuePlayer
mPlayer = [AVQueuePlayer queuePlayerWithItems: videoQueue];
// Add the player to the view
[mPlaybackView setPlayer: mPlayer];
// If you should only have one video, this allows it to stop at the end instead of blanking the display
if ([[mPlayer items] count] == 1) {
    mPlayer.actionAtItemEnd = AVPlayerActionAtItemEndNone;
}
// Start playing
[mPlayer play];


- (void) playerItemDidReachEnd: (NSNotification *)notification
{
    // Loop the video
    if (videoShouldLoop) {
        // Get the current item
        AVPlayerItem *playerItem = [mPlayer currentItem];
        // Set it back to the beginning
        [playerItem seekToTime: kCMTimeZero];
        // Tell the player to do nothing when it reaches the end of the video
        //  -- It will come back to this method when it's done
        mPlayer.actionAtItemEnd = AVPlayerActionAtItemEndNone;
        // Play it again, Sam
        [mPlayer play];
    } else {
        mPlayer.actionAtItemEnd = AVPlayerActionAtItemEndAdvance;
    }
}

That's it! Let me know of something needs further explanation.

Answer 3

I figured out a solution to loop over all the videos in my video queue, not just one. First I initialized my AVQueuePlayer :

- (void)viewDidLoad
{
    NSMutableArray *vidItems = [[NSMutableArray alloc] init];
    for (int i = 0; i < 5; i++)
    {
        // create file name and make path
        NSString *fileName = [NSString stringWithFormat:@"intro%i", i];
        NSString *path = [[NSBundle mainBundle] pathForResource:fileName ofType:@"mov"];
        NSURL *movieUrl = [NSURL fileURLWithPath:path];
        // load url as player item
        AVPlayerItem *item = [AVPlayerItem playerItemWithURL:movieUrl];
        // observe when this item ends
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(playerItemDidReachEnd:)
                                                     name:AVPlayerItemDidPlayToEndTimeNotification
                                                   object:item];
        // add to array
        [vidItems addObject:item];


    }
    // initialize avqueueplayer
    _moviePlayer = [AVQueuePlayer queuePlayerWithItems:vidItems];
    _moviePlayer.actionAtItemEnd = AVPlayerActionAtItemEndNone;

    // create layer for viewing
    AVPlayerLayer *layer = [AVPlayerLayer playerLayerWithPlayer:_moviePlayer];

    layer.frame = self.view.bounds;
    layer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    // add layer to uiview container
    [_movieViewContainer.layer addSublayer:layer];
}

When the notification is posted

- (void)playerItemDidReachEnd:(NSNotification *)notification {
    AVPlayerItem *p = [notification object];

    // keep playing the queue
    [_moviePlayer advanceToNextItem];
    // if this is the last item in the queue, add the videos back in
    if (_moviePlayer.items.count == 1)
    {
        // it'd be more efficient to make this a method being we're using it a second time
        for (int i = 0; i < 5; i++)
        {
            NSString *fileName = [NSString stringWithFormat:@"intro%i", i];
            NSString *path = [[NSBundle mainBundle] pathForResource:fileName ofType:@"mov"];
            NSURL *movieUrl = [NSURL fileURLWithPath:path];

            AVPlayerItem *item = [AVPlayerItem playerItemWithURL:movieUrl];

            [[NSNotificationCenter defaultCenter] addObserver:self
                                                     selector:@selector(playerItemDidReachEnd:)
                                                         name:AVPlayerItemDidPlayToEndTimeNotification
                                                       object:item];

             // the difference from last time, we're adding the new item after the last item in our player to maintain the order
            [_moviePlayer insertItem:item afterItem:[[_moviePlayer items] lastObject]];
        }
    }
}

Answer 4

In Swift 4, you can use something like the following:

        NotificationCenter.default.addObserver(forName: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: nil, queue: nil) {

            notification in

            print("A PlayerItem just finished playing !")

            currentVideo += 1

            if(currentVideo >= videoPaths.count) {

               currentVideo = 0
            }

            let url = URL(fileURLWithPath:videoPaths[currentVideo])
            let playerItem = AVPlayerItem.init(url: url)

            player.insert(playerItem, after: nil)
        }

From what I understand the AVQueuePlayer will remove the last item played, so you need to keep adding the video just played to the queue, otherwise it will actually run out of videos to play! You can't just .seek to 0 and .play() again, that doesn't work.

Answer 5

working on iOS 14 as of March 2021

Just wanted to post my solution as a new coder this took me a while to figure out. my solution loops a avqueuplayer inside of a UIView without using AVLooper. The idea came from raywenderlich . You can ignore the UIView wrapper ect. The idea is to use the NSKeyValeObservation and not the notification center as everyone else suggests.

class QueuePlayerUIView: UIView {
private var playerLayer = AVPlayerLayer()
private var playerLooper: AVPlayerLooper?

@objc let queuePlayer = AVQueuePlayer()

var token: NSKeyValueObservation?

var clips = [URL]()

func addAllVideosToPlayer() {
    for video in clips {
        let asset = AVURLAsset(url: video)
        let item = AVPlayerItem(asset: asset)
        queuePlayer.insert(item, after: queuePlayer.items().last)
      }
}

init(videosArr: [URL]) {
    super.init(frame: .zero)
    
    self.clips = videosArr

    addAllVideosToPlayer()
    playerLayer.player = queuePlayer
    playerLayer.videoGravity = .resizeAspectFill
    layer.addSublayer(playerLayer)
    queuePlayer.play()

    token = queuePlayer.observe(\.currentItem) { [weak self] player, _ in
      if player.items().count == 1 {
        self?.addAllVideosToPlayer()
      }
    }
}

override func layoutSubviews() {
    super.layoutSubviews()
    playerLayer.frame = bounds
}

required init?(coder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}

}