How to create a live broadcasting app in Objective C using Xcode

This guide is based on Xcode 12.5.

This guide focuses on the bare minimum required to start broadcasting. Make sure to familiarize yourself with the example apps in the SDK bundles for a more complete overview.

Create a new Application

• Open Xcode.

• Select File -> New -> Project...

• Choose the App template.

• Enter a suitable product name and add your team and your organization identifier

• Ensure Objective-C is the selected language. Or see the Swift guide if you prefer Swift.

Add dependencies

Install dependencies using CocoaPods

If your development environment is set up for it, you can use CocoaPods (opens new window) to install the Bambuser SDK:s.

• Prepare the newly created project for CocoaPods use with pod init.

• Add pod 'libbambuser-ios', '1.0.4' to your Podfile.

• Run pod install to fetch the SDK and configure the project.

Install dependencies manually

The Bambuser broadcasting library has the following dependencies:

• libz.tbd, libc++.tbd
• AudioToolbox, AVFoundation, CoreGraphics, CoreLocation, CoreMedia, CoreTelephony, CoreVideo, Foundation, QuartzCore, SystemConfiguration, UIKit, VideoToolbox

Add the broadcast SDK

• Log in to the Bambuser site and download the latest iOS SDK bundle from the Developer (opens new window) page.

• Open up Finder and navigate to the download folder, then double click the SDK bundle to unzip it.

• Go to the Frameworks directory in the SDK bundle and drag BambuserBroadcaster.xcframework into the Frameworks section of your Xcode project's file tree navigator.

• Check Copy items if needed to ensure that your project folder gets its own copy of the files.

• The act of adding BambuserBroadcaster.xcframework into Frameworks should also have added BambuserBroadcaster.xcframework to Frameworks, Libraries and Embedded Content under General.

Enable camera and microphone access

Your app will not be allowed to access the camera or microphone unless its Info.plist file contains entries for Privacy - Camera Usage Description and Privacy - Microphone Usage Description.

Double-click Info.plist to bring up the editor and add them to the bottom of the list.

Bootstrap the SDK

Now that you have installed the dependencies it's time to start using the SDK.

In ViewController.h import BambuserBroadcaster/BambuserBroadcaster.h and add BambuserView (opens new window) to the interface.

#import <UIKit/UIKit.h>
#import <BambuserBroadcaster/BambuserBroadcaster.h>

@interface ViewController : UIViewController {
	BambuserView *bambuserView;
}

@end

In ViewController.m extend the viewDidLoad method to create an instance of BambuserView (opens new window) when the viewcontroller is loaded.

BambuserView (opens new window) requires a preset, kSessionPresetAuto is optimal for most apps.

- (void) viewDidLoad {
	[super viewDidLoad];

	bambuserView = [[BambuserView alloc] initWithPreparePreset: kSessionPresetAuto];
}

Add the viewfinder

In ViewController.m in the viewDidLoad method, add the viewfinder to the view hierarchy and ensure it is rotated correctly.

[bambuserView setOrientation: [UIApplication sharedApplication].statusBarOrientation];
[self.view addSubview:bambuserView.view];

In ViewController.m add a viewWillLayoutSubviews method, then add some code to ensure the viewfinder is assigned the desired dimensions.

- (void) viewWillLayoutSubviews {
	float statusBarOffset = self.topLayoutGuide.length;
	[bambuserView setPreviewFrame: CGRectMake(0, 0 + statusBarOffset, self.view.bounds.size.width, self.view.bounds.size.height - statusBarOffset)];
}

Start capturing frames

After all settings to BambuserView has been done, add a call to to startCapture in the viewDidLoad method.

[bambuserView startCapture];

Authentication

To be able to broadcast, your app needs to identify itself to Bambuser. Head over to the Developer (opens new window) page on the Bambuser site again and get the Sandbox applicationId, then assign it to BambuserView (opens new window) in ViewController.m directly after initialization.

WARNING

Remember to replace the Sandbox id with a Production applicationId before you release your app!

bambuserView.applicationId = @"GFZalqkR5iyZcIgaolQmA";

Add a broadcasting button

Let's add a simple button to be able to control the broadcast start and stop triggers.

In ViewController.h, declare a button:

@interface ViewController : UIViewController {
	BambuserView *bambuserView;
	UIButton *broadcastButton;
}

In ViewController.m, in the viewDidLoad method, initialize the button and add it to the view hierarchy:

broadcastButton = [UIButton buttonWithType: UIButtonTypeSystem];
[broadcastButton addTarget:self action:@selector(broadcast) forControlEvents:UIControlEventTouchUpInside];
[broadcastButton setTitle:@"Broadcast" forState: UIControlStateNormal];
[self.view addSubview:broadcastButton];

In ViewController.m, in the viewWillLayoutSubviews method, position the button to taste

broadcastButton.frame = CGRectMake(20, 20 + statusBarOffset, 100, 40);

Also add a new method to handle button taps

- (void) broadcast {
	NSLog(@"Starting broadcast");
	[broadcastButton setTitle:@"Connecting" forState:UIControlStateNormal];
	[broadcastButton removeTarget:nil action:NULL forControlEvents:UIControlEventTouchUpInside];
	[broadcastButton addTarget:bambuserView action:@selector(stopBroadcasting) forControlEvents:UIControlEventTouchUpInside];
	[bambuserView startBroadcasting];
}

Subscribe to events

To know what's going on inside BambuserView (opens new window), we should hook up ourself as its delegate. In ViewController.m, assign self to bambuserView.delegate directly after initialization:

bambuserView.delegate = self;

In ViewController.h, we now need to declare that we support the BambuserViewDelegate (opens new window) protocol:

@interface ViewController : UIViewController <BambuserViewDelegate> {

Finally, we add a few callback methods in ViewController.m:

- (void) broadcastStarted {
	NSLog(@"Received broadcastStarted signal");
	[broadcastButton setTitle:@"Stop" forState:UIControlStateNormal];
	[broadcastButton removeTarget:nil action:NULL forControlEvents:UIControlEventTouchUpInside];
	[broadcastButton addTarget:bambuserView action:@selector(stopBroadcasting) forControlEvents:UIControlEventTouchUpInside];
}

- (void) broadcastStopped {
	NSLog(@"Received broadcastStopped signal");
	[broadcastButton setTitle:@"Broadcast" forState:UIControlStateNormal];
	[broadcastButton removeTarget:nil action:NULL forControlEvents:UIControlEventTouchUpInside];
	[broadcastButton addTarget:self action:@selector(broadcast) forControlEvents:UIControlEventTouchUpInside];
}

Configuring AVAudioSession

Since iOS 14.5 there is an option to prevent the system from interrupting the audio session at an incoming call notification (and thereby interrupting the broadcast), by setting [[AVAudioSession sharedInstance] setPrefersNoInterruptionsFromSystemAlerts: error:] to YES. Note! This is only effective if the user has selected Banner notification display style (Settings - Phone - Incoming calls).

Putting it all together

The above steps should lead to a main view source somewhat along these lines:

ViewController.h

#import <UIKit/UIKit.h>
#import <BambuserBroadcaster/BambuserBroadcaster.h>

@interface ViewController : UIViewController <BambuserViewDelegate> {
	BambuserView *bambuserView;
	UIButton *broadcastButton;
}

@end

ViewController.m

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
	[super viewDidLoad];

	if (@available(iOS 14.5, *)) {
		[[AVAudioSession sharedInstance] setPrefersNoInterruptionsFromSystemAlerts: YES error: nil];
	}

	bambuserView = [[BambuserView alloc] initWithPreparePreset: kSessionPresetAuto];
	bambuserView.delegate = self;
	bambuserView.applicationId = @"GFZalqkR5iyZcIgaolQmA";
	[bambuserView setOrientation: [UIApplication sharedApplication].statusBarOrientation];
	[self.view addSubview:bambuserView.view];
	[bambuserView startCapture];

	broadcastButton = [UIButton buttonWithType: UIButtonTypeSystem];
	[broadcastButton addTarget:self action:@selector(broadcast) forControlEvents:UIControlEventTouchUpInside];
	[broadcastButton setTitle:@"Broadcast" forState: UIControlStateNormal];
	[self.view addSubview:broadcastButton];
}

- (void) viewWillLayoutSubviews {
	float statusBarOffset = self.topLayoutGuide.length;
	[bambuserView setPreviewFrame: CGRectMake(0, 0 + statusBarOffset, self.view.bounds.size.width, self.view.bounds.size.height - statusBarOffset)];
	broadcastButton.frame = CGRectMake(20, 20 + statusBarOffset, 100, 40);
}

- (void) broadcast {
	NSLog(@"Starting broadcast");
	[broadcastButton setTitle:@"Connecting" forState:UIControlStateNormal];
	[broadcastButton removeTarget:nil action:NULL forControlEvents:UIControlEventTouchUpInside];
	[broadcastButton addTarget:bambuserView action:@selector(stopBroadcasting) forControlEvents:UIControlEventTouchUpInside];
	[bambuserView startBroadcasting];
}

- (void) broadcastStarted {
	NSLog(@"Received broadcastStarted signal");
	[broadcastButton setTitle:@"Stop" forState:UIControlStateNormal];
	[broadcastButton removeTarget:nil action:NULL forControlEvents:UIControlEventTouchUpInside];
	[broadcastButton addTarget:bambuserView action:@selector(stopBroadcasting) forControlEvents:UIControlEventTouchUpInside];
}

- (void) broadcastStopped {
	NSLog(@"Received broadcastStopped signal");
	[broadcastButton setTitle:@"Broadcast" forState:UIControlStateNormal];
	[broadcastButton removeTarget:nil action:NULL forControlEvents:UIControlEventTouchUpInside];
	[broadcastButton addTarget:self action:@selector(broadcast) forControlEvents:UIControlEventTouchUpInside];
}

- (void)didReceiveMemoryWarning {
	[super didReceiveMemoryWarning];
	// Dispose of any resources that can be recreated.
}

@end

Testing in the simulator

Since the iOS Simulator does not feature a camera, what you can do there is limited.

Testing on a device

How to configure Xcode for ad-hoc development is out of scope for this guide. Assuming you have all the required privileges, you should be able to tether your iOS device to Xcode and click run.

If everything is set up correctly, you should be able to start your first broadcast by tapping the button we added earlier.

Check the Bambuser site when logged in for a notification and web preview when you go live in Sandbox mode.

This is how it looks on the phone

Tap the button to start a broadcast.

Screenshot 1-2: The first time, iOS asks the user for camera and microphone access.

Screenshot 3: Then the broadcast is running and the button turns into a stop button.

Screnshot 4: Finally, we tap the button again and return to the non-broadcasting state.

What's next

• Be sure to experience a few of your live broadcasts via the Sandbox player on the Bambuser website.

• Consider whether you also need a player in your app and / or on your website.

• Study the REST APIs (opens new window) and Webhooks, which can be used to make your backend broadcast-aware.