iOS 7 AVPlayer AVPlayerItem duration incorrect in iOS 7 - ios

Question

I have the following code in my app:
NSURL *url = [NSURL fileURLWithPath: [self.DocDir stringByAppendingPathComponent: self.FileName] isDirectory: NO];
self.avPlayer = [AVPlayer playerWithURL: url];
Float64 duration = CMTimeGetSeconds(self.avPlayer.currentItem.duration);
This worked fine with iOS 6 but with iOS 7 for some reason it returns NaN. When inspecting self.avPlayer.currentItem.duration the CMTime object has 0's with a flag of 17.
Interestingly the player works fine, just the duration is wrong.
Has anyone else experienced the same issues? I am importing the following:
#import <Foundation/Foundation.h>
#import <AVFoundation/AVFoundation.h>
#import <MediaPlayer/MediaPlayer.h>
#import <CoreMedia/CoreMedia.h>
#import <AVFoundation/AVAsset.h>

Answer 1

After playing around with different ways of initializing the objects I arrived at a working solution:
AVURLAsset *asset = [AVURLAsset assetWithURL: url];
Float64 duration = CMTimeGetSeconds(asset.duration);
AVPlayerItem *item = [AVPlayerItem playerItemWithAsset: asset];
self.avPlayer = [[AVPlayer alloc] initWithPlayerItem: item];
It appears the duration value isn't always immediately available from an AVPlayerItem but it seems to work fine with an AVAsset immediately.

Answer 2

In iOS 7, for AVPlayerItem already created, you can also get duration from the underlaying asset:
CMTimeGetSeconds([[[[self player] currentItem] asset] duration]);
Instead of get it directly from AVPlayerItem, which gives you a NaN:
CMTimeGetSeconds([[[self player] currentItem] duration]);

Answer 3

The recommended way of doing this, as described in the manual is by observing the player item status:
[self.avPlayer.currentItem addObserver:self forKeyPath:#"status" options:NSKeyValueObservingOptionNew|NSKeyValueObservingOptionInitial context:nil];
Then, inside observeValueForKeyPath:ofObject:change:context:
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
// TODO: use either keyPath or context to differentiate between value changes
if (self.avPlayer.currentItem.status == AVPlayerStatusReadyToPlay) {
Float64 duration = CMTimeGetSeconds(self.avPlayer.currentItem.duration);
// ...
}
}
Also, make sure that you remove the observer when you change the player item:
if (self.avPlayer.currentItem) {
[self.avPlayer.currentItem removeObserver:self forKeyPath:#"status"];
}
Btw, you can also observe the duration property directly; however, it's been my personal experience that the results aren't as reliable as they should be ;-)

Answer 4

Swift version
You can get the duration using AVAsset which is AVPlayerItem property:
func getVideoDuration(from player: AVPlayer) -> Double? {
guard let duration = player.currentItem?.asset.duration else { return nil }
let durationSeconds = CMTimeGetSeconds(duration)
return durationSeconds
}
or by creating AVAsset from the scratch:
func getVideoDuration(for videoUrl: URL) -> Double {
let asset = AVAsset(url: videoUrl)
let duration = asset.duration
let durationSeconds = CMTimeGetSeconds(duration)
return durationSeconds
}