Red5 iOS SDK — Native WebRTC Streaming for iOS

Red5WebRTCKit is the native iOS SDK for publishing and subscribing to live streams over WebRTC. It handles ICE negotiation, codec selection, camera and microphone capture, and license validation so you can focus on building your app. The SDK works with both Red5 Cloud (Stream Manager) deployments and standalone Red5 Pro servers, and is compatible with SwiftUI and UIKit.

Requirements

iOS 13.0 or later
Xcode 14.0 or later
Swift 5.5 or later
A valid Red5 Pro SDK license key

Installation

Add the SDK to your Xcode project using Swift Package Manager. Package URL: https://github.com/red5pro/red5pro-ios-sdk Or declare it in your Package.swift:

dependencies: [
    .package(url: "https://github.com/red5pro/red5pro-ios-sdk", from: "latest")
]

Permissions

Add the following keys to your Info.plist before publishing. Camera permission is not required for audio-only sessions.

<key>NSCameraUsageDescription</key>
<string>This app needs camera access to stream video</string>
<key>NSMicrophoneUsageDescription</key>
<string>This app needs microphone access to stream audio</string>

License key setup

Pass your license key to the builder with .setLicenseKey(). The SDK validates the key asynchronously when the client is built, and fires onLicenseValidated on your delegate before any streaming can begin.

let client = Red5WebrtcClientBuilder()
    .setLicenseKey("XXXX-XXXX-XXXX-XXXX")
    // ... other configuration
    .build()

Your license key is available on the Dev Resources page in the Red5 Cloud dashboard.

Minimal publish

Publishing requires three steps after the license validates: start a camera preview, then call publish().

Build the client

Configure the client with your server details and media settings. Use setStreamManagerHost() for Red5 Cloud or setServerIp() for a standalone server.

import WebRTC
import Red5WebRTCKit

var client: Red5WebrtcClient?
let renderer = RTCMTLVideoView()

client = Red5WebrtcClientBuilder()
    .setStreamManagerHost("userid-xxx.cloud.red5.net") // Red5 Cloud
    // .setServerIp("192.168.1.100")                  // Standalone
    .setPort(443)
    .setAppName("live")
    .setStreamName("myStream")
    .setLicenseKey("XXXX-XXXX-XXXX-XXXX")
    .setVideoEnabled(true)
    .setAudioEnabled(true)
    .setEventListener(self)
    .build()

client?.setVideoRenderer(renderer)

Wait for license validation

The SDK fires onLicenseValidated before any other callback. Start the camera preview only after validation succeeds.

extension YourClass: Red5ProWebrtcEventDelegate {
    func onLicenseValidated(validated: Bool, message: String) {
        if validated {
            client?.startPreview()
        } else {
            print("License invalid: \(message)")
        }
    }
}

Publish when preview is ready

Enable your publish button in onPreviewStarted, then call publish() when the user taps it.

func onPreviewStarted() {
    // Unlock your UI
    isReady = true
}

// Called from a button tap:
client?.publish()

Stop the session

client?.stopPublish()
client?.stopPreview()

Publish lifecycle:

Red5WebrtcClientBuilder.build()
        ↓
onLicenseValidated(validated: true)
        ↓
client.startPreview()
        ↓
onPreviewStarted()          ← enable Publish button here
        ↓
client.publish()
        ↓
onPublishStarted()          ← stream is live

Subscribing does not require a preview step. Build the client, attach a renderer for the incoming video, and call subscribe().

client = Red5WebrtcClientBuilder()
    .setStreamManagerHost("userid-xxx.cloud.red5.net")
    .setPort(443)
    .setAppName("live")
    .setStreamName("myStream")
    .setLicenseKey("XXXX-XXXX-XXXX-XXXX")
    .setEventListener(self)
    .build()

client?.setVideoRenderer(renderer)
client?.subscribe()

Show the video renderer once the stream arrives:

func onSubscribeStarted() {
    hasVideo = true  // show RTCMTLVideoView in your UI
}

Audio-only streaming

Set .setVideoEnabled(false) to publish or subscribe without video. No camera permission is required, and no RTCMTLVideoView renderer is needed.

client = Red5WebrtcClientBuilder()
    .setServerIp(Config.serverIP)
    .setPort(Config.port)
    .setAppName(Config.appName)
    .setStreamName(Config.streamName)
    .setLicenseKey(Config.licenseKey)
    .setVideoEnabled(false)  // disable video track
    .setAudioEnabled(true)
    .setEventListener(self)
    .build()

// No setVideoRenderer() call needed

For audio-only publishing, call publish() directly from onLicenseValidated — no preview step is needed:

func onLicenseValidated(validated: Bool, message: String) {
    if validated {
        client?.publish()  // no startPreview() needed
    }
}

Custom video settings

Configure resolution, frame rate, and bitrate on the builder before calling .build(). These settings cannot be changed after the client is created.

client = Red5WebrtcClientBuilder()
    // ... connection config ...
    .setVideoWidth(1280)    // pixels
    .setVideoHeight(720)    // pixels
    .setVideoFps(30)        // frames per second
    .setVideoBitrate(1500)  // kilobits per second
    .build()

Recommended presets:

Quality	Width	Height	FPS	Bitrate
360p	640	360	30	400 kbps
480p	854	480	30	750 kbps
720p	1280	720	30	1500 kbps
720p 60fps	1280	720	60	2500 kbps
1080p	1920	1080	30	3000 kbps

Bitrate is a target, not a guarantee. WebRTC’s congestion control may lower it dynamically if network conditions degrade. To change settings after a session starts, stop and release the client, then rebuild with new parameters.

Camera controls

Call these methods on the client instance any time after startPreview() completes. Switch between front and back camera:

client?.switchCamera()

Mute and unmute video:

client?.setVideoEnabled(false) // viewer sees a black/frozen frame
client?.setVideoEnabled(true)  // live camera resumes

Mute and unmute audio:

client?.setAudioEnabled(false) // viewer hears silence
client?.setAudioEnabled(true)  // microphone resumes

SwiftUI pattern:

@State private var videoMuted = false
@State private var audioMuted = false

Button("Mute Video") {
    videoMuted.toggle()
    client?.setVideoEnabled(!videoMuted)
}

Button("Flip Camera") {
    client?.switchCamera()
}

Event reference

Implement Red5ProWebrtcEventDelegate in your class to receive SDK lifecycle events. All methods have default no-op implementations, so you only need to override the callbacks you care about.

Publish events

Callback	Description
`onPublishStarted()`	Publish session started successfully
`onPublishStopped()`	Publish session ended
`onPublishFailed(error: String)`	Publish session failed

Subscribe events

Callback	Description
`onSubscribeStarted()`	Subscribe session started successfully
`onSubscribeStopped()`	Subscribe session ended
`onSubscribeFailed(error: String)`	Subscribe session failed

Connection and lifecycle events

Callback	Description
`onPreviewStarted()`	Local camera preview is running
`onPreviewStopped()`	Local camera preview stopped
`onLicenseValidated(validated: Bool, message: String)`	License check completed — always fires first
`onIceConnectionStateChanged(state: IceConnectionState)`	ICE connection state changed
`onConnectionStateChanged(state: PeerConnectionState)`	Peer connection state changed
`onError(error: String)`	An unrecoverable error occurred

Chat events

Callback	Description
`onChatConnected()`	Connected to the PubNub chat service
`onChatDisconnected()`	Disconnected from the PubNub chat service
`onChatMessageReceived(channel: String, message: Any)`	Message received on the subscribed channel
`onChatSendSuccess(channel: String, timetoken: NSNumber)`	Message sent successfully
`onChatSendError(channel: String, errorMessage: String)`	Message failed to send

Configuration reference

Key Red5WebrtcClientBuilder methods:

Method	Default	Description
`setStreamManagerHost(_ host: String)`	—	Stream Manager host for Red5 Cloud
`setServerIp(_ ip: String)`	—	Standalone server IP address
`setPort(_ port: Int)`	`443`	Server port
`setAppName(_ name: String)`	`"live"`	Application scope name
`setStreamName(_ name: String)`	—	Stream name
`setLicenseKey(_ key: String)`	—	Red5 Pro license key
`setVideoEnabled(_ enabled: Bool)`	`true`	Enable or disable video
`setAudioEnabled(_ enabled: Bool)`	`true`	Enable or disable audio
`setVideoWidth(_ width: Int)`	`640`	Capture width in pixels
`setVideoHeight(_ height: Int)`	`480`	Capture height in pixels
`setVideoFps(_ fps: Int)`	`30`	Frame rate
`setVideoBitrate(_ bitrate: Int)`	`500`	Bitrate in kbps
`setEventListener(_ delegate)`	—	SDK event delegate

Example apps

Each example is a self-contained Xcode project. Copy Config.swift and the example file into a fresh project, fill in your server details, and run.

01-MinimalPublish — fewest lines needed to go live
02-MinimalSubscribe — fewest lines needed to receive a stream
03-AudioOnly — publish or subscribe with video disabled
04-CustomVideoSettings — configure resolution, frame rate, and bitrate
05-CameraControls — flip camera, mute/unmute video and audio while live

Browse all examples on GitHub

​Requirements

​Installation

​Permissions

​License key setup

​Minimal publish

​Minimal subscribe

​Audio-only streaming

​Custom video settings

​Camera controls

​Event reference

​Configuration reference

​Example apps

Requirements

Installation

Permissions

License key setup

Minimal publish

Minimal subscribe

Audio-only streaming

Custom video settings

Camera controls

Event reference

Configuration reference

Example apps