title: Swift AVPlayer seekToTime issue
body: <p>i have this code :</p>
  
  <pre><code>let punto = sender.locationInView(self.barraVideo).x
          let larghezzaImg : Double = Double((self.barraVideoInvisTocco?.frame.width)!)
  
          let percTocco : Double = (100 / larghezzaImg) * Double(punto)
  
          let lunghezzaVideo : Double = Double(CGFloat((avPlayer?.currentItem?.asset.duration.value)!) / CGFloat(1000.0));
          let frameRate : Int32 = (avPlayer?.currentItem?.currentTime().timescale)!
  
          let secondo : Float64 = Float64((lunghezzaVideo/100)*percTocco)
          print("Val : \(secondo)");
  
          avPlayer?.currentItem?.seekToTime(CMTimeMakeWithSeconds(secondo, frameRate))
  
          avPlayer?.play()
          videoInPlay = true;
          playPauseBtn!.image = UIImage(named: "iconaPausa.png")!;
  </code></pre>
  
  <p>That recive a x cordinate of a tap on the seekBar and seek the video.
  The code works with logs video but work very bad with short videos.
  When i tap on the short video the AVPlayer seek only near the begining or near the end of the video, not in the middle</p>
  
  <p>print :</p>
  
  <pre><code>Val : 3.36008475976495
  Val : 7.14189817632069
  Val : 13.3303201306846
  Val : 3.70388597945183
  Val : 3.93308679257642
  Val : 3.24548435320265
  Val : 3.70388597945183
  Val : 18.8311396456748
  Val : 27.0823689181601
  Val : 40.1468152662618
  Val : 51.3776551093667
  Val : 17.2267339538027
  Val : 9.54850671412889
  Val : 23.4151559081666
  Val : 37.6256063218913
  </code></pre>
  
  <p>The val rappresents the right value of seconds where i wont to seek.
  Sorry for bad english, i'm italian</p>