[ios] How to play a local video with Swift?

these code is converted code from gbk answer in swift 4

1.in your main controllview :

 if let filePath = Bundle.main.path(forResource: "clip", ofType: "mp4") {
            let fileURL = NSURL(fileURLWithPath: filePath)
            videoPlayer = VideoPlayer(urlAsset: fileURL, view: playerView)
            if let player = videoPlayer {
                player.playerRate = 1.00
            }
        }

2. you need VideoPlayer class

   import AVFoundation
   
   import Foundation
   
   protocol VideoPlayerDelegate {
       func downloadedProgress(progress:Double)
       func readyToPlay()
       func didUpdateProgress(progress:Double)
       func didFinishPlayItem()
       func didFailPlayToEnd()
   }
   
   let videoContext:UnsafeMutablePointer<Void>? = nil
   class VideoPlayer : NSObject {
       private var assetPlayer:AVPlayer?
       private var playerItem:AVPlayerItem?
       private var urlAsset:AVURLAsset?
       private var videoOutput:AVPlayerItemVideoOutput?
   
       private var assetDuration:Double = 0
       private var playerView:PlayerView?
   
       private var autoRepeatPlay:Bool = true
       private var autoPlay:Bool = true
   
       var delegate:VideoPlayerDelegate?
   
       var playerRate:Float = 1 {
           didSet {
               if let player = assetPlayer {
                   player.rate = playerRate > 0 ? playerRate : 0.0
               }
           }
       }
   
       var volume:Float = 0 {
           didSet {
               if let player = assetPlayer {
                   player.volume = 50
               }
           }
       }
   
       // MARK: - Init
   
       convenience init(urlAsset:NSURL, view:PlayerView, startAutoPlay:Bool = true, repeatAfterEnd:Bool = true) {
           self.init()
   
           playerView = view
           autoPlay = startAutoPlay
           autoRepeatPlay = repeatAfterEnd
   
           if let playView = playerView{
               if let playerLayer = playView.layer as? AVPlayerLayer {
                   playerLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
               }
           }
   
           initialSetupWithURL(url: urlAsset)
           prepareToPlay()
       }
   
       override init() {
           super.init()
       }
   
       // MARK: - Public
   
       func isPlaying() -> Bool {
           if let player = assetPlayer {
               return player.rate > 0
           } else {
               return false
           }
       }
   
       func seekToPosition(seconds:Float64) {
           if let player = assetPlayer {
               pause()
               if let timeScale = player.currentItem?.asset.duration.timescale {
                   player.seek(to: CMTimeMakeWithSeconds(seconds, timeScale), completionHandler: { (complete) in
                       self.play()
                   })
               }
           }
       }
   
       func pause() {
           if let player = assetPlayer {
               player.pause()
           }
       }
   
       func play() {
           if let player = assetPlayer {
               if (player.currentItem?.status == .readyToPlay) {
                   player.play()
                   player.rate = playerRate
               }
           }
       }
   
       func cleanUp() {
           if let item = playerItem {
               item.removeObserver(self, forKeyPath: "status")
               item.removeObserver(self, forKeyPath: "loadedTimeRanges")
           }
           NotificationCenter.default.removeObserver(self)
           assetPlayer = nil
           playerItem = nil
           urlAsset = nil
       }
   
       // MARK: - Private
   
       private func prepareToPlay() {
           let keys = ["tracks"]
           if let asset = urlAsset {
   
   
   
               asset.loadValuesAsynchronously(forKeys: keys, completionHandler: {
                   DispatchQueue.global(qos: .userInitiated).async {
                       // Bounce back to the main thread to update the UI
                       DispatchQueue.main.async {
                           self.startLoading()
                       }
                   }
               })
   
           }
       }
   
       private func startLoading(){
           var error:NSError?
   
           guard let asset = urlAsset else {return}
   
   
   //         let status:AVKeyValueStatus = asset.statusOfValueForKey("tracks", error: &error)
      let status:AVKeyValueStatus = asset.statusOfValue(forKey: "tracks", error: nil)
   
   
           if status == AVKeyValueStatus.loaded {
               assetDuration = CMTimeGetSeconds(asset.duration)
   
               let videoOutputOptions = [kCVPixelBufferPixelFormatTypeKey as String : Int(kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange)]
               videoOutput = AVPlayerItemVideoOutput(pixelBufferAttributes: videoOutputOptions)
               playerItem = AVPlayerItem(asset: asset)
   
               if let item = playerItem {
                   item.addObserver(self, forKeyPath: "status", options: .initial, context: videoContext)
                   item.addObserver(self, forKeyPath: "loadedTimeRanges", options: [.new, .old], context: videoContext)
   
                   NotificationCenter.default.addObserver(self, selector: #selector(playerItemDidReachEnd), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: nil)
                   NotificationCenter.default.addObserver(self, selector: #selector(didFailedToPlayToEnd), name:NSNotification.Name.AVPlayerItemFailedToPlayToEndTime, object: nil)
   
   
                   if let output = videoOutput {
                       item.add(output)
   
                       item.audioTimePitchAlgorithm = AVAudioTimePitchAlgorithm.varispeed
                       assetPlayer = AVPlayer(playerItem: item)
   
                       if let player = assetPlayer {
                           player.rate = playerRate
                       }
   
                       addPeriodicalObserver()
                       if let playView = playerView, let layer = playView.layer as? AVPlayerLayer {
                           layer.player = assetPlayer
                       }
                   }
               }
           }
       }
   
       private func addPeriodicalObserver() {
           let timeInterval = CMTimeMake(1, 1)
   
   
   
   
           if let player = assetPlayer {
               player.addPeriodicTimeObserver(forInterval: timeInterval, queue:
                  DispatchQueue.main
                   , using: { (time) in
                   self.playerDidChangeTime(time: time)
               })
           }
   
   
       }
   
       private func playerDidChangeTime(time:CMTime) {
           if let player = assetPlayer {
               let timeNow = CMTimeGetSeconds(player.currentTime())
               let progress = timeNow / assetDuration
   
               delegate?.didUpdateProgress(progress: progress)
           }
       }
   
       @objc private func playerItemDidReachEnd() {
           delegate?.didFinishPlayItem()
   
           if let player = assetPlayer {
               player.seek(to: kCMTimeZero)
               if autoRepeatPlay == true {
                   play()
               }
           }
       }
   
       @objc private func didFailedToPlayToEnd() {
           delegate?.didFailPlayToEnd()
       }
   
       private func playerDidChangeStatus(status:AVPlayerStatus) {
           if status == .failed {
               print("Failed to load video")
           } else if status == .readyToPlay, let player = assetPlayer {
               volume = player.volume
               delegate?.readyToPlay()
   
               if autoPlay == true && player.rate == 0.0 {
                   play()
               }
           }
       }
   
       private func moviewPlayerLoadedTimeRangeDidUpdated(ranges:Array<NSValue>) {
           var maximum:TimeInterval = 0
           for value in ranges {
               let range:CMTimeRange = value.timeRangeValue
               let currentLoadedTimeRange = CMTimeGetSeconds(range.start) + CMTimeGetSeconds(range.duration)
               if currentLoadedTimeRange > maximum {
                   maximum = currentLoadedTimeRange
               }
           }
           let progress:Double = assetDuration == 0 ? 0.0 : Double(maximum) / assetDuration
   
           delegate?.downloadedProgress(progress: progress)
       }
   
       deinit {
           cleanUp()
       }
   
       private func initialSetupWithURL(url:NSURL) {
           let options = [AVURLAssetPreferPreciseDurationAndTimingKey : true]
   
   
   //        urlAsset = AVURLAsset(URL: url, options: options)
           urlAsset = AVURLAsset(url: url as URL, options: options)
   
       }
   
       // MARK: - Observations
   
   
   
   
       override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?){
           if (context as? UnsafeMutablePointer<Void> ) == videoContext {
               if let key = keyPath {
                   if key == "status", let player = assetPlayer {
                       playerDidChangeStatus(status: player.status)
                   } else if key == "loadedTimeRanges", let item = playerItem {
                       moviewPlayerLoadedTimeRangeDidUpdated(ranges: item.loadedTimeRanges)
                   }
               }
           }
       }
   
   
   }
   

3. and a PlayerView class to create a videoview:

     import AVFoundation
   
     import UIKit
   
     class PlayerView: UIView {
   
   
   override class var layerClass: AnyClass {
       get {
         return AVPlayerLayer.self
       }
   }
   
   
   var player:AVPlayer? {
       set {
           if let layer = layer as? AVPlayerLayer {
               layer.player = player
           }
       }
       get {
           if let layer = layer as? AVPlayerLayer {
               return layer.player
           } else {
               return nil
           }
       }
   }
   }