AVPlayer, notification for play/pause state?

AVPalyer as default observer to track the current duration of the video ,when you pause or resume the video you can get paused time by using one global variable (inside observer update that variable)

CMTime interval = CMTimeMake(1, 1);

//The capture of self here is coming in with your implicit property access of self.currentduration - you can't refer to self or properties on self from within a block that will be strongly retained by self.

//You can get around this by creating a weak reference to self before accessing timerDisp inside your block
__weak typeof(self) weakSelf = self;

self.timeObserverToken = [_player addPeriodicTimeObserverForInterval:interval queue:NULL usingBlock: ^(CMTime time)
{
    _currentDuration = (int)CMTimeGetSeconds (_player.currentTime);

    if(!_isPlaying)
    {
        _pausedDuration = _currentDuration;
    }
}

For iOS 10 onwards You can check new property of AVPlayer timeControlStatus.

if(avPlayerObject.timeControlStatus==AVPlayerTimeControlStatusPaused)
{
//Paused mode
}
else if(avPlayerObject.timeControlStatus==AVPlayerTimeControlStatusPlaying)
{
 //Play mode
}

Why do you say that "rate" is not KVO complaint? It works for me.

Here is what I did:

- (void)viewDidLoad
{
    ...

    [self.player addObserver:self forKeyPath:@"rate" options:0 context:nil];
}

And then:

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
if ([keyPath isEqualToString:@"rate"]) {
    if ([self.player rate]) {
        [self changeToPause];  // This changes the button to Pause
    }
    else {
        [self changeToPlay];   // This changes the button to Play
    }
}
}