Question

Apples documentation alludes to it, but how do you set up key-value observation for the loadedTimeRanges property of AVPlayerItem? That property is an NSArray that doesn’t change, so you can’t just use playerItem addObserver:self forKeyPath:@"loadedTimeRanges ...

Or is there another way to get notifications or updates whenever this changes?

Answer 1

Actually, I’m using KVO for loadedTimeRanges without any trouble. Maybe you’re just not setting the right options? The following is a very slight modification of some of the code in Apple’s AVPlayerDemo, and it’s working quite nicely for me.

//somewhere near the top of the file
NSString * const kLoadedTimeRangesKey   = @"loadedTimeRanges";
static void *AudioControllerBufferingObservationContext = &AudioControllerBufferingObservationContext;


- (void)someFunction
{  
    // ...

    //somewhere after somePlayerItem has been initialized
    [somePlayerItem addObserver:self
                       forKeyPath:kLoadedTimeRangesKey
                          options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
                          context:AudioControllerBufferingObservationContext];

    // ...
}

- (void)observeValueForKeyPath:(NSString*) path 
                  ofObject:(id)object 
                    change:(NSDictionary*)change 
                   context:(void*)context
{
    if (context == AudioControllerBufferingObservationContext)
    {
        NSLog(@"Buffering status: %@", [object loadedTimeRanges]);
    }
}