Тормозит скраббер в AVPlayer?

Question

[deleted-mezhevikin]

По примеру от apple делаю плеер на основе AVPlayer. ( AVPlayerDemo )
AVPlayer умеет воспроизводить удаленные файлы, но если включить видео с сервера и начать перематывать скраббер(UISlider) начинает глючить.

При этом в MPMoviePlayerViewController все перематывается плавно.
Есть ли идеи как это поправить?

Код моего тестового проекта - https://github.com/nullproduction/Player

Так реализована перемотка:

[scrubberSlider addTarget:self action:@selector(beginScrubbing:) forControlEvents:UIControlEventTouchDown];
    [scrubberSlider addTarget:self action:@selector(endScrubbing:) forControlEvents:UIControlEventTouchUpInside];
    [scrubberSlider addTarget:self action:@selector(endScrubbing:) forControlEvents:UIControlEventTouchUpOutside];
    [scrubberSlider addTarget:self action:@selector(scrub:) forControlEvents:UIControlEventValueChanged];

- (void)initScrubberTimer
{
	double interval = .1f;
	
	CMTime playerDuration = [self playerItemDuration];
	if (CMTIME_IS_INVALID(playerDuration))
	{
		return;
	}
	double duration = CMTimeGetSeconds(playerDuration);
	if (isfinite(duration))
	{
		CGFloat width = CGRectGetWidth([scrubberSlider bounds]);
		interval = 0.5f * duration / width;
	}
    
    __weak id weakSelf = self;
    CMTime intervalSeconds = CMTimeMakeWithSeconds(interval, NSEC_PER_SEC);
    mTimeObserver = [self.player addPeriodicTimeObserverForInterval:intervalSeconds
                                                              queue:dispatch_get_main_queue()
                                                         usingBlock:^(CMTime time) {
                                                             [weakSelf syncScrubber];
                                                         }];
    
}


- (void)syncScrubber
{
	CMTime playerDuration = [self playerItemDuration];
	if (CMTIME_IS_INVALID(playerDuration))
	{
		scrubberSlider.minimumValue = 0.0;
		return;
	}
    
	double duration = CMTimeGetSeconds(playerDuration);
	if (isfinite(duration))
	{
		float minValue = [scrubberSlider minimumValue];
		float maxValue = [scrubberSlider maximumValue];
		double time = CMTimeGetSeconds([self.player currentTime]);
		
		[scrubberSlider setValue:(maxValue - minValue) * time / duration + minValue];
	}
}

- (IBAction)beginScrubbing:(id)sender
{
    mRestoreAfterScrubbingRate = [self.player rate];
	[self.player setRate:0.f];
	
	[self removePlayerTimeObserver];
}


- (IBAction)scrub:(id)sender
{
	if ([sender isKindOfClass:[UISlider class]])
	{
		UISlider* slider = sender;
		
		CMTime playerDuration = [self playerItemDuration];
		if (CMTIME_IS_INVALID(playerDuration))
        {
			return;
		}
		
		double duration = CMTimeGetSeconds(playerDuration);
		if (isfinite(duration))
		{
			float minValue = [slider minimumValue];
			float maxValue = [slider maximumValue];
			float value = [slider value];
			
			double time = duration * (value - minValue) / (maxValue - minValue);
			
			[self.player seekToTime:CMTimeMakeWithSeconds(time, NSEC_PER_SEC)];
		}
	}
}

- (IBAction)endScrubbing:(id)sender
{
    if (!mTimeObserver)
	{
		CMTime playerDuration = [self playerItemDuration];
		if (CMTIME_IS_INVALID(playerDuration))
		{
			return;
		}
		
		double duration = CMTimeGetSeconds(playerDuration);
		if (isfinite(duration))
		{
			CGFloat width = CGRectGetWidth([scrubberSlider bounds]);
			double tolerance = 0.5f * duration / width;
            
            __weak id weakSelf = self;
            CMTime intervalSeconds = CMTimeMakeWithSeconds(tolerance, NSEC_PER_SEC);
            mTimeObserver = [self.player addPeriodicTimeObserverForInterval:intervalSeconds
                                                                      queue:dispatch_get_main_queue()
                                                                 usingBlock: ^(CMTime time) {
                                                                     [weakSelf syncScrubber];
                                                                 }];
		}
	}
    
    if (mRestoreAfterScrubbingRate)
	{
		[self.player setRate:mRestoreAfterScrubbingRate];
		mRestoreAfterScrubbingRate = 0.f;
	}
}