Animate AVPlayerLayer videoGravity property

Question

I\'m trying to copy Apple\'s behavior in video playback that allows the user to stretch the video image to fill the bounds.

@interface FHVideoPlayerView : UI         


        

Answer 1

It was a bug in iOS 5.0 and iOS 5.0.1.

After updating to iOS 5.1 the video gravity changing animation begun to work again.

Answer 2

As voromax pointed out, this is a bug in iOS 5.0. I reverse engineered -[AVPlayerLayer setVideoGravity:] implementation in iOS 5.1 in order to understand how the animation was supposed to work. Here is how to workaround the bug and have a nice animation on iOS 5.0.

@implementation VideoPlayerView

+ (Class) layerClass
{
    return [AVPlayerLayer class];
}

- (AVPlayerLayer *) playerLayer
{
    return (AVPlayerLayer *)[self layer];
}

- (NSString *) videoGravity
{
    return self.playerLayer.videoGravity;
}

- (void) setVideoGravity:(NSString *)videoGravity
{
    self.playerLayer.videoGravity = videoGravity;

    // Workaround a bug in iOS 5.0
    float avFoundationVersion = [[[NSBundle bundleForClass:[AVPlayerLayer class]] objectForInfoDictionaryKey:(NSString *)kCFBundleVersionKey] floatValue];
    if (avFoundationVersion < 292.24f)
    {
        @try
        {
            NSString *contentLayerKeyPath = [NSString stringWithFormat:@"%1$@%2$@.%3$@%2$@", @"player", [@"layer" capitalizedString], @"content"]; // playerLayer.contentLayer
            CALayer *contentLayer = [self.playerLayer valueForKeyPath:contentLayerKeyPath];
            if ([contentLayer isKindOfClass:[CALayer class]])
                [contentLayer addAnimation:[CABasicAnimation animation] forKey:@"sublayerTransform"];
        }
        @catch (NSException *exception)
        {
        }
        self.bounds = self.bounds;
    }
}

@end