Set up IMA SDK

#import "ViewController.h"
#import <AVKit/AVKit.h>

@import GoogleInteractiveMediaAds;
ViewController.m

import AVFoundation
import GoogleInteractiveMediaAds
import UIKit
ViewController.swift

NSString *const kContentURLString =
    @"https://storage.googleapis.com/interactive-media-ads/media/stock.mp4";
NSString *const kAdTagURLString =
    @"https://pubads.g.doubleclick.net/gampad/ads?"
    @"iu=/21775744923/external/vmap_ad_samples&sz=640x480&"
    @"cust_params=sample_ar%3Dpremidpostlongpod&ciu_szs=300x250&gdfp_req=1&ad_rule=1&"
    @"output=vmap&unviewed_position_start=1&env=vp&cmsid=496&vid=short_onecue&correlator=";

@interface ViewController () <IMAAdsLoaderDelegate, IMAAdsManagerDelegate>
@property(nonatomic) IMAAdsLoader *adsLoader;
@property(nonatomic) IMAAdDisplayContainer *adDisplayContainer;
@property(nonatomic) IMAAdsManager *adsManager;
@property(nonatomic) IMAAVPlayerContentPlayhead *contentPlayhead;
@property(nonatomic) AVPlayerViewController *contentPlayerViewController;
@property(nonatomic, getter=isAdBreakActive) BOOL adBreakActive;
@end

@implementation ViewController

- (void)viewDidLoad {
  [super viewDidLoad];
  self.view.backgroundColor = [UIColor blackColor];
  [self setupAdsLoader];
  [self setupContentPlayer];
}

- (void)viewDidAppear:(BOOL)animated {
  [super viewDidAppear:animated];
  [self requestAds];
}

// Add the content video player as a child view controller.
- (void)showContentPlayer {
  [self addChildViewController:self.contentPlayerViewController];
  self.contentPlayerViewController.view.frame = self.view.bounds;
  [self.view insertSubview:self.contentPlayerViewController.view atIndex:0];
  [self.contentPlayerViewController didMoveToParentViewController:self];
}

// Remove and detach the content video player.
- (void)hideContentPlayer {
  // The whole controller needs to be detached so that it doesn't capture resume events from the
  // remote and play content underneath the ad.
  [self.contentPlayerViewController willMoveToParentViewController:nil];
  [self.contentPlayerViewController.view removeFromSuperview];
  [self.contentPlayerViewController removeFromParentViewController];
}
ViewController.m

class ViewController: UIViewController, IMAAdsLoaderDelegate, IMAAdsManagerDelegate {
  static let contentURLString =
    "https://devstreaming-cdn.apple.com/videos/streaming/examples/"
    + "img_bipbop_adv_example_fmp4/master.m3u8"
  static let adTagURLString =
    "https://pubads.g.doubleclick.net/gampad/ads?iu=/21775744923/external/single_ad_samples&"
    + "sz=640x480&cust_params=sample_ct%3Dlinear&ciu_szs=300x250%2C728x90&gdfp_req=1&output=vast&"
    + "unviewed_position_start=1&env=vp&correlator="

  var adsLoader: IMAAdsLoader!
  var adDisplayContainer: IMAAdDisplayContainer!
  var adsManager: IMAAdsManager!
  var contentPlayhead: IMAAVPlayerContentPlayhead?
  var playerViewController: AVPlayerViewController!
  var adBreakActive = false

  deinit {
    NotificationCenter.default.removeObserver(self)
  }

  override func viewDidLoad() {
    super.viewDidLoad()
    self.view.backgroundColor = UIColor.black
    setUpContentPlayer()
    setUpAdsLoader()
  }

  override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    requestAds()
  }
ViewController.swift

- (void)setupContentPlayer {
  // Create a content video player. Create a playhead to track content progress so the SDK knows
  // when to play ads in a VMAP playlist.
  NSURL *contentURL = [NSURL URLWithString:kContentURLString];
  AVPlayer *player = [AVPlayer playerWithURL:contentURL];
  self.contentPlayerViewController = [[AVPlayerViewController alloc] init];
  self.contentPlayerViewController.player = player;
  self.contentPlayerViewController.view.frame = self.view.bounds;
  self.contentPlayhead =
      [[IMAAVPlayerContentPlayhead alloc] initWithAVPlayer:self.contentPlayerViewController.player];

  // Track end of content.
  AVPlayerItem *contentPlayerItem = self.contentPlayerViewController.player.currentItem;
  [[NSNotificationCenter defaultCenter] addObserver:self
                                           selector:@selector(contentDidFinishPlaying:)
                                               name:AVPlayerItemDidPlayToEndTimeNotification
                                             object:contentPlayerItem];

  // Attach content video player to view hierarchy.
  [self showContentPlayer];
}
ViewController.m

func setUpContentPlayer() {
  // Load AVPlayer with path to our content.
  let contentURL = URL(string: ViewController.contentURLString)!
  let player = AVPlayer(url: contentURL)
  playerViewController = AVPlayerViewController()
  playerViewController.player = player

  // Set up our content playhead and contentComplete callback.
  contentPlayhead = IMAAVPlayerContentPlayhead(avPlayer: player)
  NotificationCenter.default.addObserver(
    self,
    selector: #selector(ViewController.contentDidFinishPlaying(_:)),
    name: NSNotification.Name.AVPlayerItemDidPlayToEndTime,
    object: player.currentItem)

  showContentPlayer()
}
ViewController.swift

- (void)contentDidFinishPlaying:(NSNotification *)notification {
  // Notify the SDK that the postrolls should be played.
  [self.adsLoader contentComplete];
}

- (void)dealloc {
  [[NSNotificationCenter defaultCenter] removeObserver:self];
}
ViewController.m

@objc func contentDidFinishPlaying(_ notification: Notification) {
  adsLoader.contentComplete()
}
ViewController.swift

- (void)setupAdsLoader {
  self.adsLoader = [[IMAAdsLoader alloc] init];
  self.adsLoader.delegate = self;
}

- (void)requestAds {
  // Pass the main view as the container for ad display.
  self.adDisplayContainer = [[IMAAdDisplayContainer alloc] initWithAdContainer:self.view
                                                                viewController:self];
  IMAAdsRequest *request = [[IMAAdsRequest alloc] initWithAdTagUrl:kAdTagURLString
                                                adDisplayContainer:self.adDisplayContainer
                                                   contentPlayhead:self.contentPlayhead
                                                       userContext:nil];
  [self.adsLoader requestAdsWithRequest:request];
}
ViewController.m

func setUpAdsLoader() {
  adsLoader = IMAAdsLoader(settings: nil)
  adsLoader.delegate = self
}

func requestAds() {
  // Create ad display container for ad rendering.
  adDisplayContainer = IMAAdDisplayContainer(adContainer: self.view, viewController: self)
  // Create an ad request with our ad tag, display container, and optional user context.
  let request = IMAAdsRequest(
    adTagUrl: ViewController.adTagURLString,
    adDisplayContainer: adDisplayContainer,
    contentPlayhead: contentPlayhead,
    userContext: nil)

  adsLoader.requestAds(with: request)
}
ViewController.swift

#pragma mark - IMAAdsLoaderDelegate

- (void)adsLoader:(IMAAdsLoader *)loader adsLoadedWithData:(IMAAdsLoadedData *)adsLoadedData {
  // Initialize and listen to the ads manager loaded for this request.
  self.adsManager = adsLoadedData.adsManager;
  self.adsManager.delegate = self;
  [self.adsManager initializeWithAdsRenderingSettings:nil];
}

- (void)adsLoader:(IMAAdsLoader *)loader failedWithErrorData:(IMAAdLoadingErrorData *)adErrorData {
  // Fall back to playing content.
  NSLog(@"Error loading ads: %@", adErrorData.adError.message);
  [self.contentPlayerViewController.player play];
}
ViewController.m

func adsLoader(_ loader: IMAAdsLoader, adsLoadedWith adsLoadedData: IMAAdsLoadedData) {
  // Grab the instance of the IMAAdsManager and set ourselves as the delegate.
  adsManager = adsLoadedData.adsManager
  adsManager.delegate = self
  adsManager.initialize(with: nil)
}

func adsLoader(_ loader: IMAAdsLoader, failedWith adErrorData: IMAAdLoadingErrorData) {
  print("Error loading ads: \(adErrorData.adError.message ?? "No error message available.")")
  showContentPlayer()
  playerViewController.player?.play()
}
ViewController.swift

#pragma mark - IMAAdsManagerDelegate

- (void)adsManager:(IMAAdsManager *)adsManager didReceiveAdEvent:(IMAAdEvent *)event {
  switch (event.type) {
    case kIMAAdEvent_LOADED: {
      // Play each ad once it has loaded.
      [adsManager start];
      break;
    }
    case kIMAAdEvent_ICON_FALLBACK_IMAGE_CLOSED: {
      // Resume ad after user has closed dialog.
      [adsManager resume];
      break;
    }
    default:
      break;
  }
}
ViewController.m

func adsManager(_ adsManager: IMAAdsManager, didReceive event: IMAAdEvent) {
  switch event.type {
  case IMAAdEventType.LOADED:
    // Play each ad once it has been loaded.
    adsManager.start()
  case IMAAdEventType.ICON_FALLBACK_IMAGE_CLOSED:
    // Resume playback after the user has closed the dialog.
    adsManager.resume()
  default:
    break
  }
}
ViewController.swift

- (void)adsManager:(IMAAdsManager *)adsManager didReceiveAdError:(IMAAdError *)error {
  // Fall back to playing content.
  NSLog(@"AdsManager error: %@", error.message);
  [self showContentPlayer];
  [self.contentPlayerViewController.player play];
}
ViewController.m

func adsManager(_ adsManager: IMAAdsManager, didReceive error: IMAAdError) {
  // Fall back to playing content
  print("AdsManager error: \(error.message ?? "No error message available.")")
  showContentPlayer()
  playerViewController.player?.play()
}
ViewController.swift

- (void)adsManagerDidRequestContentPause:(IMAAdsManager *)adsManager {
  // Pause the content for the SDK to play ads.
  [self.contentPlayerViewController.player pause];
  [self hideContentPlayer];
  // Trigger an update to send focus to the ad display container.
  self.adBreakActive = YES;
  [self setNeedsFocusUpdate];
}

- (void)adsManagerDidRequestContentResume:(IMAAdsManager *)adsManager {
  // Resume the content since the SDK is done playing ads (at least for now).
  [self showContentPlayer];
  [self.contentPlayerViewController.player play];
  // Trigger an update to send focus to the content player.
  self.adBreakActive = NO;
  [self setNeedsFocusUpdate];
}
ViewController.m

func adsManagerDidRequestContentPause(_ adsManager: IMAAdsManager) {
  // Pause the content for the SDK to play ads.
  playerViewController.player?.pause()
  hideContentPlayer()
  // Trigger an update to send focus to the ad display container.
  adBreakActive = true
  setNeedsFocusUpdate()
}

func adsManagerDidRequestContentResume(_ adsManager: IMAAdsManager) {
  // Resume the content since the SDK is done playing ads (at least for now).
  showContentPlayer()
  playerViewController.player?.play()
  // Trigger an update to send focus to the content player.
  adBreakActive = false
  setNeedsFocusUpdate()
}
ViewController.swift