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

Here a solution for Swift 5.2

PlayerView.swift:

import AVFoundation
import UIKit

class PlayerView: UIView {

    var player: AVPlayer? {
        get {
            return playerLayer.player
        }
        set {
            playerLayer.player = newValue
        }
    }

    var playerLayer: AVPlayerLayer {
        return layer as! AVPlayerLayer
    }

    // Override UIView property
    override static var layerClass: AnyClass {
        return AVPlayerLayer.self
    }
}

VideoPlayer.swift

import AVFoundation
import Foundation

protocol VideoPlayerDelegate {
    func downloadedProgress(progress:Double)
    func readyToPlay()
    func didUpdateProgress(progress:Double)
    func didFinishPlayItem()
    func didFailPlayToEnd()
}

let videoContext: UnsafeMutableRawPointer? = 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 = 1.0 {
        didSet {
            if let player = assetPlayer {
                player.volume = volume > 0 ? volume : 0.0
            }
        }
    }

    // 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, 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, preferredTimescale: 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.main.async {
                    self.startLoading()
                }
            })
        }
    }

    private func startLoading(){
        var error:NSError?
        guard let asset = urlAsset else {return}
        let status:AVKeyValueStatus = asset.statusOfValue(forKey: "tracks", error: &error)

        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
                        print("player created")
                    }
                }
            }
        }
    }

    private func addPeriodicalObserver() {
        let timeInterval = CMTimeMake(value: 1, timescale: 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: CMTime.zero)
            if autoRepeatPlay == true {
                play()
            }
        }
    }

    @objc private func didFailedToPlayToEnd() {
        delegate?.didFailPlayToEnd()
    }

    private func playerDidChangeStatus(status:AVPlayer.Status) {
        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 as URL, options: options)
    }

    // MARK: - Observations
    override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {

        if context == 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)
                }
            }
        }
    }
}

Usage:

private var playerView: PlayerView = PlayerView()
private var videoPlayer:VideoPlayer?

and inside viewDidLoad():

view.addSubview(playerView)
preparePlayer()

// set Constraints (if you do it purely in code)
playerView.translatesAutoresizingMaskIntoConstraints = false
playerView.topAnchor.constraint(equalTo: view.topAnchor, constant: 10.0).isActive = true
playerView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 10.0).isActive = true
playerView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -10.0).isActive = true
playerView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 10.0).isActive = true

private func preparePlayer() {
    if let filePath = Bundle.main.path(forResource: "my video", ofType: "mp4") {
        let fileURL = NSURL(fileURLWithPath: filePath)
        videoPlayer = VideoPlayer(urlAsset: fileURL, view: playerView)
        if let player = videoPlayer {
            player.playerRate = 0.67
        }
    }
}