I am using an AVPlayerLayer to play video in the background of my UIViewController instance. When I launched my app on the iPhone I noticed that magnifying glass appearing in a wrong way. Video specifications: H.264, AAC, 640x360, MOV.
The background inside magnifying glass drawing without my video sublayer. Only subviews (buttons, text fields, etc.) are drawing inside my magnifying glass.
- (void)viewDidLoad
{
[super viewDidLoad];
self.view.backgroundColor = [UIColor yellowColor];
NSURL *videoURL = [[NSBundle mainBundle] URLForResource:@"bf4" withExtension:@"mov"];
AVAsset *asset = [AVAsset assetWithURL:videoURL];
AVPlayerItem *item = [AVPlayerItem playerItemWithAsset:asset];
AVPlayer *player = [AVPlayer playerWithPlayerItem:item];
player.actionAtItemEnd = AVPlayerActionAtItemEndNone;
UIView *container = [[UIView alloc] initWithFrame:self.view.bounds];
container.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
[self.view addSubview:container];
AVPlayerLayer *layer = [AVPlayerLayer playerLayerWithPlayer:player];
[container.layer addSublayer:layer];
layer.frame = container.bounds;
layer.videoGravity = AVLayerVideoGravityResizeAspectFill;
[self.view bringSubviewToFront:self.textField];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2.0f * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[player play];
});
}
Does anyone know how to prevent this?
The only one solution I figured out is to:
Put UIImageView
below container
view:
self.containerThumbnail = [[UIImageView alloc] initWithFrame:self.view.bounds];
self.containerThumbnail.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
self.containerThumbnail.backgroundColor = [UIColor clearColor];
[self.view insertSubview:self.containerThumbnail belowSubview:container];
Become a time observer to the media player:
CMTime bgInterval = CMTimeMake(1, 10);
__weak __typeof(self)weakSelf = self;
[player addPeriodicTimeObserverForInterval:bgInterval
queue:dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0)
usingBlock:^(CMTime time)
{
[weakSelf locateThumbnail:time];
}];
Put snapshots inside your UIImageView
:
- (void)locateThumbnail:(CMTime)time
{
__weak __typeof(self)weakSelf = self;
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^(void) {
CGImageRef imageRef = [weakSelf.imageGenerator copyCGImageAtTime:time actualTime:NULL error:NULL];
UIImage *image = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
__strong __typeof(weakSelf)strongSelf = weakSelf;
dispatch_async(dispatch_get_main_queue(), ^(void) {
strongSelf.containerThumbnail.image = image;
});
});
}
The property imageGenerator
is of type AVAssetImageGenerator
:
imageGenerator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
imageGenerator.appliesPreferredTrackTransform = YES;
N.B. Snapshots updates in the background and because of this frames lag behind the video. But this is better than nothing.