1. Adding the video file - Add the video (lets call it video.m4v) to your Xcode project

2. Checking your video is into the Bundle
   - Open the Project Navigator cmd + 1

Then select your project root > your Target > Build Phases > Copy Bundle Resources.

Your video MUST be here. If it's not, then you should add it using the plus button

1. Code - Open your View Controller and write this code.

import UIKit
import AVKit
import AVFoundation

class ViewController: UIViewController {

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        playVideo()
    }

    private func playVideo() {
        guard let path = Bundle.main.path(forResource: "video", ofType:"m4v") else {
            debugPrint("video.m4v not found")
            return
        }
        let player = AVPlayer(url: URL(fileURLWithPath: path))
        let playerController = AVPlayerViewController()
        playerController.player = player
        present(playerController, animated: true) {
            player.play()
        }
    }
}

Original By: appzYourLife

Reference: StackOverflow: how-to-play-a-local-video-with-swift