In this tutorial, we'll use Stream Chat and Dolby.io's Client SDK to build an app that lets you create a room that streams the contents of your screen and your voice for a large number of viewers and allows them to interact with each other via chat. It will be as simple as possible for the sake of keeping this tutorial as short as possible, but it will function enough to have fun with your friends.
That animation shows an iPhone accessing a channel created by an iPad user who is playing Minecraft. The iPhone user can hear the streamer's voice, see the gameplay, and interact with other watchers via chat.
If you get lost during this tutorial, you can check the completed project in this GitHub repo.
What is Stream Chat?
Build real-time chat in less time. Rapidly ship in-app messaging with our highly reliable chat infrastructure. Drive in-app conversion, engagement, and retention with the Stream Chat messaging platform API & SDKs.
What is Dolby.io's Client SDK?
Dolby Interactivity APIs provide a platform for unified communications and collaboration. In-flow communications refers to the combination of voice, video, and messaging integrated into your application in a way that is cohesive for your end-users. This is in contrast to out-of-app communications where users must stop using your application and instead turn to third-party tools.
Requirements
Set up project
Create the Xcode project
First, we open Xcode and create a Single View App project.
And make sure to select 'UIKit' for the User Interface.
Install dependencies
To install the Stream Chat and Dolby.io's Client SDK dependencies, we'll use CocoaPods. If you prefer Carthage, both frameworks support it as well.
In the folder where you saved the project, run pod init and add StreamChat, VoxeetSDK, and VoxeetScreenShareKit to the Podfile. It should look similar to this:
# Uncomment the next line to define a global platform for your project
# platform :ios, '9.0'
target 'Smitch' do
# Comment the next line if you don't want to use dynamic frameworks
use_frameworks!
# Pods for Smitch
pod 'StreamChat', '~> 2.1'
pod 'VoxeetSDK', '~> 2.3'
pod 'VoxeetScreenShareKit', '~> 1.0'
endAfter you do that, run pod install, wait a bit for it to finish, and open the project via the .xcworkspace that was created.
Configure the Stream Chat dashboard
Sign up at GetStream.io, create the application, and make sure to select development instead of production.
To make things simple for now, let's disable both auth checks and permission checks. Make sure to hit save. When your app is in production, you should keep these enabled.
You can see the documentation about authentication here and permissions here.
Now, save your Stream credentials, as we'll need them to power the chat in the app. Since we disabled auth and permissions, we'll only really need the key for now, but in production, you'll use the secret in your backend to create JWTs to allow users to interact with your app securely.
As you can see, I've blacked out my keys. You should make sure to keep your credentials safe.
Configure the Dolby.io dashboard
Configuring the Dolby.io dashboard is simpler. Just create an account there, and it should already set up an initial application for you.
Now, save your credentials, as we'll need them to power the audio and video streaming in the app. As with the Stream credentials, you use these for development. In production, you'll need to set up proper authentication. It's described in detail here.
Configure Stream Chat and Dolby's SDKs
The first step with code is to configure the Stream and Dolby SDK with the credentials from the dashboards. Open the AppDelegate.swift file and modify it, so it looks similar to this:
import UIKit
import VoxeetSDK
import StreamChatClient
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
VoxeetSDK.shared.initialize(consumerKey: "ZTBib3I3NzkzMmt0aA==", consumerSecret: "NDUyM2kzMTc0ZHNvZWxjaHRucG41dmpidnE=")
VoxeetSDK.shared.appGroup = "group.so.cardo.Smitch.Group"
VoxeetSDK.shared.preferredExtension = "so.cardo.Smitch.Broadcast"
Client.configureShared(.init(apiKey: "74e5enp33qj2", logOptions: .info))
Client.shared.set(user: .init(id: generateUserId()), token: .development)
return true
}
}That code initializes the Dolby.io and Stream Chat SDKs with credentials you got in the previous two steps.
Create the Join Screen
Let's start building the "Join" screen. This screen consists of two elements: a UITextField for determining the channel's name and a UIButton to join or create the channel depending on whether it was already created. If you're creating it, you're automatically its admin, and you may share the code with other users to join as watchers. It will look similar to the screenshot below.
Go to the Storyboard, select the default view controller, and click Editor > Embed In > Navigation Controller. That will place it under a navigation controller, which we'll use to navigate to the channel screen.
Make sure to rename ViewController to JoinViewController so you don't get confused later on. You can do this easily by right-clicking on ViewController in ViewController.swift and selecting refactor.
To make things simple, let's leave the storyboard like this and use only code from now on. To set up the UITextField and UIButton we need the following code in JoinViewController.swift:
import UIKit
class JoinViewController: UIViewController {
let channelTextField = UITextField()
let joinButton = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
title = "Join Channel"
setupViews()
setupConstraints()
setupHandlers()
}
}That code sets up the views, the constraints, and the handlers we need. Let's start by extending JoinViewController to define setupViews:
extension JoinViewController {
func setupViews() {
setupChannelTextField()
setupJoinButton()
}
func setupChannelTextField() {
channelTextField.translatesAutoresizingMaskIntoConstraints = false
channelTextField.becomeFirstResponder()
view.addSubview(channelTextField)
}
func setupJoinButton() {
joinButton.translatesAutoresizingMaskIntoConstraints = falseThat code will create the UITextField, UIButton, and add them to the controller's view. Next, we need to define constraints between those three. Let's do this by extending JoinViewController to define setupConstraints:
extension JoinViewController {
func setupConstraints() {
view.addConstraints([
channelTextField.widthAnchor.constraint(equalToConstant: 100),
channelTextField.centerXAnchor.constraint(equalTo: view.centerXAnchor),
channelTextField.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 10),
joinButton.centerXAnchor.constraint(equalTo: view.centerXAnchor),
joinButton.topAnchor.constraint(equalTo: channelTextField.bottomAnchor)
])
}
}That code will make sure the channelTextField stays on top and center of the screen and the joinButton right below it. Now we need to set up the handler for when the user presses the button. Let's do this again by extending the controller to define setupHandlers:
import Foundation
extension JoinViewController {
func setupHandlers() {
joinButton.addTarget(self, action: #selector(handleButtonPress), for: .touchUpInside)
}
@objc func handleButtonPress() {
let watchVC = WatchViewController()
watchVC.channelName = channelTextField.text!
navigationController?.pushViewController(watchVC, animated: true)
}
}That code will make it so when the user presses the button a WatchViewController is created with its .channelName property set to the contents of the UITextField. We'll create WatchViewController in the next step.
Create the Watch Screen
Now, let's create the screen where we can view or transmit a stream and chat. We'll start by defining WatchViewController. It will look similar to the animation below.
First step is to create a WatchViewController.swift file and paste the code below.
import UIKit
import VoxeetSDK
import StreamChat
class WatchViewController: UIViewController {
var channelName: String = "default"
let voxeet = VoxeetSDK.shared
let userId = generateUserId()
let videoView = VTVideoView()
let chatViewController = ChatViewController()
override var prefersStatusBarHidden: Bool { true }
override func viewDidLoad() {That code simply defines some variables that we'll need frequently and calls some functions to set everything up on viewDidLoad. We'll create those next. It also makes sure to leave the conference once the view is freed from memory in deinit and hides the status bar on viewDidAppear for presentation purposes.
Additionally, generateUserId() is a simple function that generates a random id for the user. You should define it in a generateUserId.swift file as below.
import Foundation
func generateUserId(length: Int = 10) -> String {
let letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
return String((0..<length).map{ _ in letters.randomElement()! })
}Next, let's define the functions to set up the views, chat, and stream. First, define setupViews as below.
extension WatchViewController {
func setupViews() {
setupVideoView()
setupChatView()
}
func setupVideoView() {
view.addSubview(videoView)
}
func setupChatView() {
addChild(chatViewController)
view.addSubview(chatViewController.view)
}
}That code just adds the video and chat views to the view hierarchy.
Next, let's define setupConstraints to specify the layout that those views should take.
extension WatchViewController {
func setupConstraints() {
setupVideoConstraints()
setupChatConstraints()
}
func setupVideoConstraints() {
videoView.translatesAutoresizingMaskIntoConstraints = false
view.addConstraints([
videoView.topAnchor.constraint(equalTo: view.topAnchor),
videoView.rightAnchor.constraint(equalTo: view.rightAnchor),
videoView.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 1/3),
videoView.leftAnchor.constraint(equalTo: view.leftAnchor)
])
}That code will make sure the video view sits on top of the chat view on a 1 to 3 ratio for the height.
Next, let's define the setupChat function.
https://gist.github.com/cardoso/dd6d16e39eae24812799cfd34983f741
That code simply tells the chatViewController to present a channel with id equal to the channelName property and with type livestream. There are several channel types with different behaviors, and more can be created. You can read about them here. Livestream is the one that fits our use case the most.
Next, we need the functions to configure the video portion.
import VoxeetSDK
import ReplayKit
extension WatchViewController {
func setupStream() {
let info = VTParticipantInfo(externalID: userId, name: userId, avatarURL: nil)
voxeet.conference.delegate = self
voxeet.session.open(info: info) { error in
self.joinOrCreateConference()
}
}
func joinOrCreateConference() {
let options = VTConferenceOptions()Those functions will set up a conference session. If the conference is new, the user's screen will be presented. If not, the user will watch the presentation by the user who created the channel.
Now, we need to conform WatchViewController to the VTConferenceDelegate protocol.
import VoxeetSDK
extension WatchViewController: VTConferenceDelegate {
func streamAdded(participant: VTParticipant, stream: MediaStream) {
switch stream.type {
case .ScreenShare:
videoView.alpha = 1
videoView.attach(participant: participant, stream: stream)
default:
break
}
}
func streamUpdated(participant: VTParticipant, stream: MediaStream) {
That code displays the video feed when a screen share is detected and hides the video when the screen share finishes.
Enable System-wide Screen Sharing
If you run the app now, and create a channel, when you put it in the background, the video stream remains in the app. Of course, this is not good, because we want to stream games and other apps. To fix this, you need to set up App Groups and a Broadcast Upload extension. This process is simple and well described in Dolby.io's documentation. Click this link to head over there.
At the time of writing this tutorial, ReplayKit doesn't work with the new UIScene lifecycle, so you need to rollback to the old AppDelegate approach.
Wrapping up
Congratulations! You've built the basis of a functioning game live streaming app with Stream Chat and Dolby.io. I encourage you to browse through Stream Chat's docs and gaming chat API as well as Dolby's docs, and experiment with the project you just built. For more, check out our UX best practices for livestream chat.
