title: iOS - AVPlayer seekToTime restarts playback of currentItem
body: <p>I'm making an app that uses AVPlayer. In one of my views I have a UISlider with which the user should be able to scrub forward and backward. I'm having some trouble getting <code>seekToTime</code> to work as I want. When I try to change time the playback starts from 0, and I'm not sure how to solve this. My current implementation looks like this:</p>
  
  <pre><code>[self.progressSlider  addTarget:self action:@selector(sliderValueChanged) forControlEvents:UIControlEventValueChanged];
  
  [self.progressSlider  addTarget:self action:@selector(sliderReleased) forControlEvents:UIControlEventTouchUpInside];
  
  
  - (void)sliderValueChanged {
  
      [...]
      [player pause];
  
  }
  
  - (void)sliderReleased {
  
      float timeInSecond = self.progressSlider.value;
  
      timeInSecond *= 1000;
  
      // I have trie to hard code this value, but I get the same result.
      CMTime cmTime = CMTimeMake(timeInSecond, NSEC_PER_SEC);
  
      [player.currentItem seekToTime:cmTime toleranceBefore:kCMTimeZero toleranceAfter:kCMTimeZero completionHandler:^(BOOL finished) {
  
          if (finished) {
              [player play];
          }
      }];
  }
  </code></pre>
  
  <p>Any ideas on what I'm doing wrong?</p>
  
  <p>Can mention that I stream audio using AVPlayer's: <code>playerItemWithURL</code> if that makes any difference.</p>