ios - check valid url to play in avplayercontroller? -

i have 3 urls , have check if these urls have video link play or not. have esc link if not contain video in url , play video next url. following code track playing state.

let playerav = avplayerviewcontroller()   var player = avplayer()   playerav.player = player   playerav.view.frame = cgrectmake(0, 0,  self.videoview.frame.width,  self.videoview.frame.height)   self.addchildviewcontroller(playerav)   self.videoview.addsubview(playerav.view)   playerav.didmovetoparentviewcontroller(self)   playerav.player?.play()   addobserverofmovieplayer()   nsnotificationcenter.defaultcenter().addobserver(self, selector: #selector(channeldetailviewcontroller.notificationobserver(_:)), name:avplayeritemdidplaytoendtimenotification , object: player.currentitem)     _ = uidevice.begingeneratingdeviceorientationnotifications     nsnotificationcenter.defaultcenter().addobserver(self, selector: #selector(channeldetailviewcontroller.deviceorientationdidchange(_:)) , name:       uideviceorientationdidchangenotification, object: nil)     playerav.player!.addobserver(self, forkeypath: "rate", options: nskeyvalueobservingoptions.new, context: nil)     playerav.player!.currentitem!.addobserver(self, forkeypath: "playbackbufferempty", options: nskeyvalueobservingoptions.new, context: nil)     playerav.player!.currentitem!.addobserver(self, forkeypath: "playbacklikelytokeepup", options: nskeyvalueobservingoptions.new, context: nil)  override func observevalueforkeypath(keypath: string?, ofobject object: anyobject?, change: [string : anyobject]?, context: unsafemutablepointer<void>) {      if keypath == "rate"   {        if let rate = change?[nskeyvaluechangenewkey] as? float {         if playerav.player!.currentitem!.status == avplayeritemstatus.readytoplay{           if rate != 0 && playerav.player!.error == nil {              print("normal playback")             timer = nstimer.scheduledtimerwithtimeinterval(1, target: self, selector: #selector(channeldetailviewcontroller.somaction), userinfo: nil, repeats: true)            }           else{             timer?.invalidate()             print("movie player stopped")           }          }else if playerav.player!.currentitem?.status == avplayeritemstatus.unknown{           timer?.invalidate()           print("not ready play")         }       }     }     if keypath == "playbackbufferempty"{        if playerav.player?.currentitem?.playbackbufferempty == true{         timer?.invalidate()         print("movie player stopped due no buffer")       }     }      if keypath == "playbacklikelytokeepup" {        if playerav.player?.currentitem?.playbacklikelytokeepup == true{          print("movie player playing after enough data in buffer")         playerav.player?.play()        }     }   } 

just check length of video if it's invalid length return 0 code :

let assets = avasset(url: nsurl(fileurlwithpath: filepath)) let length=float(assets.duration.value)/float(assets.duration.timescale) if length != 0.0  { // play } 

if have still problem can ask me anytime.