Most effective method for video as background in iOS

Question

Perhaps you have noticed one of the latest trend in iOS-apps: Using videos as backgrounds - mainly at login- or "first launch" screens. Yesterday I attempted to mimic this with a very simple test project (only one view controller) and I am pleased with the results except for the performance. When trying it out in the iOS Simulator (on a simulated iPhone 6) the CPU usage fluctuates between 70-110%. This seems very unreasonable for a simple login-screen.

This is what it looks like in action: http://oi57.tinypic.com/nqqntv.jpg

The question is then: Is there a more CPU-effective way to achieve this? How are the apps like Vine, Spotify and Instagram doing this?

Before you answer; the method I used was a full-HD video played back using MPMoviePlayerController:

- (void)viewDidLoad {
    [super viewDidLoad];

    // find movie file
    NSString *moviePath = [[NSBundle mainBundle] pathForResource:@"arenaVideo" ofType:@"mp4"];
    NSURL *movieURL = [NSURL fileURLWithPath:moviePath];

    // load movie
    self.moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:movieURL];
    self.moviePlayer.controlStyle = MPMovieControlStyleNone;
    self.moviePlayer.view.frame = self.view.frame;
    self.moviePlayer.scalingMode = MPMovieScalingModeAspectFill;
    [self.view addSubview:self.moviePlayer.view];
    [self.view sendSubviewToBack:self.moviePlayer.view];
    [self.moviePlayer play];

    // loop movie
    [[NSNotificationCenter defaultCenter] addObserver: self
                                             selector: @selector(replayMovie:)
                                                 name: MPMoviePlayerPlaybackDidFinishNotification
                                               object: self.moviePlayer];
}

#pragma mark - Helper methods

-(void)replayMovie:(NSNotification *)notification
{
    [self.moviePlayer play];
}

Of course the edges of the video could have been trimmed so that the resolution would be something more along the lines of say 700x1080 instead of 1920x1080 but would that have made a huge difference in performance? Or should I compress the video with a certain format and settings to achieve optimal performance? Maybe there is an entirely alternate approach to this?

Actually I tried using GIFs as described in this article: https://medium.com/swift-programming/ios-make-an-awesome-video-background-view-objective-c-swift-318e1d71d0a2

The problem with that is:

• Creating GIFs out of videos takes a lot of time and effort
• I saw no significant decrease of CPU usage when I tried it
• Supporting multiple screen sizes is a total pain with this approach (at least when I tried - with Autolayout and Size Classes enabled - I couldn't get the GIF to scale correctly across devices)
• Quality of video is poor

Answer 1

Best way is to use AVFoundation then you control the video layer itself

In header file declare @property (nonatomic, strong) AVPlayerLayer *playerLayer;

- (void)viewDidLoad {
      [super viewDidLoad];


      [self.view.layer addSublayer:self.playerLayer];

      // loop movie
      [[NSNotificationCenter defaultCenter] addObserver: self
                                             selector: @selector(replayMovie:)
                                             name: AVPlayerItemDidPlayToEndTimeNotification 
                                             object:nil];
}
-(AVPlayerLayer*)playerLayer{
      if(!_playerLayer){

         // find movie file
         NSString *moviePath = [[NSBundle mainBundle] pathForResource:@"arenaVideo" ofType:@"mp4"];
         NSURL *movieURL = [NSURL fileURLWithPath:moviePath];
         _playerLayer = [AVPlayerLayer playerLayerWithPlayer:[[AVPlayer alloc]initWithURL:movieURL]];
         _playerLayer.frame = CGRectMake(0,0,self.view.frame.size.width, self.view.frame.size.height);
         [_playerLayer.player play];

      }
    return _playerLayer
}
-(void)replayMovie:(NSNotification *)notification
{
    [self.playerLayer.player play];
}

Swift 2.0

lazy var playerLayer:AVPlayerLayer = {

    let player = AVPlayer(URL:  NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("LaunchMovie", ofType: "mov")!))
    player.muted = true
    player.allowsExternalPlayback = false
    player.appliesMediaSelectionCriteriaAutomatically = false
    var error:NSError?

    // This is needed so it would not cut off users audio (if listening to music etc.
    do {
        try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryAmbient)
    } catch var error1 as NSError {
        error = error1
    } catch {
        fatalError()
    }
    if error != nil {
        print(error)
    }

    var playerLayer = AVPlayerLayer(player: player)
    playerLayer.frame = self.view.frame
    playerLayer.videoGravity = "AVLayerVideoGravityResizeAspectFill"
    playerLayer.backgroundColor = UIColor.blackColor().CGColor
    player.play()
    NSNotificationCenter.defaultCenter().addObserver(self, selector:"playerDidReachEnd", name:AVPlayerItemDidPlayToEndTimeNotification, object:nil)
    return playerLayer
    }()

override func viewDidLoad() {
    super.viewDidLoad()
    self.view.layer.addSublayer(self.playerLayer)
}
override func viewWillDisappear(animated: Bool) {
    NSNotificationCenter.defaultCenter().removeObserver(self)
}
// If orientation changes
override func willAnimateRotationToInterfaceOrientation(toInterfaceOrientation: UIInterfaceOrientation, duration: NSTimeInterval) {
    playerLayer.frame = self.view.frame
}
func playerDidReachEnd(){
    self.playerLayer.player!.seekToTime(kCMTimeZero)
    self.playerLayer.player!.play()

}

Tested on iOS7 - iOS9

Answer 2

I realize that this is an old post but being that I have had some experience bringing down the CPU usage in my iOS app, I'll respond.

first place to look is use AVFoundationFramework

Implementing AVPlayer should help bring down the CPU a little

but the best solution is to use Brad Larson's GPUImage library which utilizes OpenGl and will reduce the CPU usage greatly. Download the library and there are examples of how to use. I recommend using GPUImageMovieWriter