Gist trying to answer a Swift Korea (Facebook Group) question.

PlayerViewController.swift

import UIKit
import PlaygroundSupport
import AVFoundation

class PlayerViewController: UIViewController {

    enum Settings {
        static let screenW: CGFloat = 375 // For playground use only
        static let playerHeight: CGFloat = Settings.screenW * (9/16)
        static let videoUrl = URL(string: "https://clips.vorwaerts-gmbh.de/big_buck_bunny.mp4")!
    }

    let playerView: UIView = {
        let view = UIView()
        view.translatesAutoresizingMaskIntoConstraints = false
        view.backgroundColor = .green
        return view
    }()

    let playerLayer: AVPlayerLayer = {
        let layer = AVPlayerLayer()
        layer.videoGravity = .resizeAspect
        return layer
    }()

    let button: UIButton = {
        let button = UIButton()
        button.translatesAutoresizingMaskIntoConstraints = false
        button.backgroundColor = .lightGray
        button.addTarget(self,
                         action: #selector(onButton),
                         for: .touchUpInside)
        return button
    }()

    let player = AVPlayer(url: Settings.videoUrl)

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .red

        view.addSubview(playerView)
        view.addSubview(button)

        setupPlayerView()

        NSLayoutConstraint.activate([
            button.bottomAnchor.constraint(equalTo: view.bottomAnchor),
            button.rightAnchor.constraint(equalTo: view.rightAnchor),
            button.leftAnchor.constraint(equalTo: view.leftAnchor),
            button.heightAnchor.constraint(equalToConstant: 50),
        ])

        player.play()
    }

    private func setupPlayerView() {
        NSLayoutConstraint.activate([
            playerView.topAnchor.constraint(equalTo: view.topAnchor),
            playerView.leftAnchor.constraint(equalTo: view.leftAnchor),
            playerView.rightAnchor.constraint(equalTo: view.rightAnchor),
            playerView.heightAnchor.constraint(equalToConstant: Settings.playerHeight),
        ])
        playerView.layer.addSublayer(playerLayer)
        playerLayer.player = player
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        playerLayer.frame = playerView.bounds
    }

    @objc
    private func onButton() {
        print("onButton()")
    }
}

let viewController = PlayerViewController()
PlaygroundPage.current.liveView = viewController