Looping Avplayer Seamlessly

AVPlayerLoop not seamlessly looping - Swift 4

One thing to to keep in mind when looping assets is that audio and video tracks can have different offsets and different durations, resulting in 'blips' when looping. Such small differences are quite common in recorded assets.

Iterating over the tracks and printing the time ranges can help to detect such situations: for track in asset.tracks { print( track.mediaType); CMTimeRangeShow( track.timeRange); }

To trim audio and video tracks to equal start times and equal durations, get the common time range of the tracks, and then insert this time range from the original asset into a new AVMutableComposition. Normally, you also want to preserve properties like the orientation of the video track:

let asset: AVAsset = (your asset initialization here)

let videoTrack: AVAssetTrack = asset.tracks(withMediaType: .video).first!
let audioTrack: AVAssetTrack = asset.tracks(withMediaType: .audio).first!

// calculate common time range of audio and video track
let timeRange: CMTimeRange = CMTimeRangeGetIntersection( (videoTrack.timeRange), (audioTrack.timeRange))

let composition: AVMutableComposition = AVMutableComposition()

try composition.insertTimeRange(timeRange, of: asset, at: kCMTimeZero)

// preserve orientation
composition.tracks(withMediaType: .video).first!.preferredTransform = videoTrack.preferredTransform

Since AVMutableComposition is a subclass of AVAsset, it can be used for AVPlayerLooper-based looping playback, or exporting with AVAssetExportSession.

I've put a more complete trimming implementation on github: https://github.com/fluthaus/NHBAVAssetTrimming. It's more robust, handles multiple tracks, preserves more properties and can either be easily integrated in projects or be build as a standalone macOS command line movie trimming utility.

Problem when attempting to loop AVPlayer (userCapturedVideo) seamlessly

I did the same thing a few years back using this piece of code:

var player: AVPlayer!
var playerLayer: AVPlayerLayer!

private func playVideo(name: String) {
    guard let path = Bundle.main.path(forResource: name, ofType:"mp4") else { return }
    player = AVPlayer(url: NSURL(fileURLWithPath: path) as URL)
    playerLayer = AVPlayerLayer(player: player)
    self.playerLayer.frame = SOME_BOUNDS
    self.player!.play()
    NotificationCenter.default.addObserver(self, selector: #selector(playerDidFinishPlaying(note:)), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: player.currentItem)
}

@objc func playerDidFinishPlaying(note: NSNotification) {
    print("Video Finished")
    self.playerLayer.removeFromSuperlayer()
    playVideo(name: "SOME_NAME")
}

Hope this points you to your desired functionality

Seamless Loop Video

I was able to get this to loop seamless with avlooper.

#import "VideoWindow.h"
#import <AVFoundation/AVFoundation.h>
#import <AVKit/AVKit.h>

@interface VideoWindow ()

@property (strong) IBOutlet AVPlayerView *playerView;
@property (strong) IBOutlet NSWindow *aspectView;

@end

@implementation VideoWindow

{
    AVPlayerItem *_playerItem;
    AVQueuePlayer *_player;
    AVPlayerLooper *_playerLooper;
    AVPlayerLayer *_playerLayer;
}


- (void)windowDidLoad {
    [super windowDidLoad];
    NSString *videoFile = [[NSBundle mainBundle] pathForResource:@"Video2" ofType:@"mp4"];
    NSURL *videoURL = [NSURL fileURLWithPath:videoFile];
    _playerItem = [AVPlayerItem playerItemWithURL:videoURL];
    _player = [AVQueuePlayer queuePlayerWithItems:@[_playerItem]];
    _playerLooper = [AVPlayerLooper playerLooperWithPlayer:_player templateItem:_playerItem];
    _playerLayer = [AVPlayerLayer playerLayerWithPlayer:_player];
    _playerLayer.frame = self.playerView.bounds;
    _playerLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    [self.playerView.layer addSublayer:_playerLayer];
    [_aspectView setAspectRatio:NSMakeSize(16, 9)];
    [_player play];
}



- (void)windowWillClose:(NSNotification *)aNotification {
    [_player pause];
    [_player seekToTime:kCMTimeZero];
}

@end

Looping a video with AVFoundation AVPlayer?

You can get a Notification when the player ends. Check AVPlayerItemDidPlayToEndTimeNotification

When setting up the player:

ObjC

  avPlayer.actionAtItemEnd = AVPlayerActionAtItemEndNone; 

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

this will prevent the player to pause at the end.

in the notification:

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

this will rewind the movie.

Don't forget un unregister the notification when releasing the player.

Swift

avPlayer?.actionAtItemEnd = .none

NotificationCenter.default.addObserver(self,
                                       selector: #selector(playerItemDidReachEnd(notification:)),
                                       name: .AVPlayerItemDidPlayToEndTime,
                                       object: avPlayer?.currentItem)

@objc func playerItemDidReachEnd(notification: Notification) {
    if let playerItem = notification.object as? AVPlayerItem {
        playerItem.seek(to: kCMTimeZero)
    }
}

Swift 4+

@objc func playerItemDidReachEnd(notification: Notification) {
    if let playerItem = notification.object as? AVPlayerItem {
        playerItem.seek(to: CMTime.zero, completionHandler: nil)
    }
}

AVAudioPlayer loops are not seamless

Using AVAudioEngine will give you a lot of flexibility but it's overhead if you don't need anything else but sync your tracks.

In this case you can try to use a single player with AVComposition containing all your tracks, something like this:

func generateComposition(urls: [URL]) throws -> AVComposition {
    let composition = AVMutableComposition()
    let audioTracks = urls
        .map(AVAsset.init(url:))
        .flatMap { $0.tracks(withMediaType: .audio) }
    
    for audioTrack in audioTracks {
        guard
            let compositionTrack = composition.addMutableTrack(withMediaType: .audio, preferredTrackID: kCMPersistentTrackID_Invalid)
        else { continue }
        
        try compositionTrack.insertTimeRange(
            audioTrack.timeRange,
            of: audioTrack,
            at: .zero
        )
    }
    return composition
}

And play it using AVPlayer:

AVPlayer(playerItem: AVPlayerItem(asset: composition))

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