How to Integrate RTMP Live Stream in Flutter Video Call App?

Introduction

Integrate real-time messaging protocol (RTMP) livestream functionality seamlessly into your Flutter video call application for a dynamic and engaging user experience. With RTMP support, users can effortlessly stream live video content, fostering interactive communication within your app. Enable users to broadcast their video feeds in real-time, creating vibrant and immersive virtual gatherings. Implementing RTMP in your Flutter app ensures smooth and efficient live streaming, enhancing the overall quality of video calls.

Benefits of RTMP Livestream:

Improved Communication: RTMP enhances communication by allowing users to share live video content, fostering collaboration and information sharing.
High-Quality Streaming: RTMP ensures high-quality video streaming with minimal latency, providing users with a seamless viewing experience.
Scalability: With RTMP support, your app can accommodate a large number of simultaneous viewers, making it suitable for hosting virtual events of varying sizes.
Enhanced User Engagement: RTMP livestreaming facilitates real-time interaction, keeping users engaged and connected during video calls.

Use Cases of RTMP Livestream:

Virtual Events: Host virtual conferences, concerts, or seminars where participants can stream live video content to engage with the audience in real-time.
Educational Platforms: Enable teachers to conduct live lectures and interactive sessions, allowing students to stream video content and ask questions in real-time.
Remote Work: Facilitate remote meetings and conferences where participants can share live video presentations and collaborate effectively

This tutorial VideoSDK provides clear instructions and code examples to help you seamlessly integrate RTMP live streaming into your Flutter video-calling app.

Getting Started with VideoSDK

To integrate RTMP, we must use the capabilities of VideoSDK and what it offers. Before diving into the implementation steps, let's ensure you complete the necessary prerequisites.

Create a VideoSDK Account

Go to your VideoSDK dashboard and sign up if you don't have an account. This account gives you access to the required Video SDK token, which acts as an authentication key that allows your application to interact with VideoSDK functionality.

Generate your Auth Token

Visit your VideoSDK dashboard and navigate to the "API Key" section to generate your auth token. This token is crucial in authorizing your application to use VideoSDK features.

For a more visual understanding of the account creation and token generation process, consider referring to the provided tutorial.

Prerequisites

Before proceeding, ensure that your development environment meets the following requirements:

Video SDK Developer Account (if you do not have one, follow VideoSDK Dashboard)
The basic understanding of Flutter.
Flutter VideoSDK
Have Flutter installed on your device.

Install VideoSDK

Install the VideoSDK using the below-mentioned flutter command. Make sure you are in your Flutter app directory before you run this command.

$ flutter pub add videosdk

//run this command to add http library to perform network call to generate roomId
$ flutter pub add http

VideoSDK Compatibility

Android and iOS app	Web	Desktop app	Safari browser
✅	✅	✅	❌

Structure of the project

Your project structure should look like this.

    root
    ├── android
    ├── ios
    ├── lib
         ├── api_call.dart
         ├── join_screen.dart
         ├── main.dart
         ├── meeting_controls.dart
         ├── meeting_screen.dart
         ├── participant_tile.dart

We are going to create flutter widgets (JoinScreen, MeetingScreen, MeetingControls, and ParticipantTile).

App Structure

The app widget will contain JoinScreen and MeetingScreen widget. MeetingScreen will have MeetingControls and ParticipantTile widget.

Configure Project

For Android

Update /android/app/src/main/AndroidManifest.xml for the permissions we will be using to implement the audio and video features.

<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
<uses-permission android:name="android.permission.WAKE_LOCK" />

AndroidManifest.xml

Also, you will need to set your build settings to Java 8 because the official WebRTC jar now uses static methods in EglBase the interface. Just add this to your app-level /android/app/build.gradle.

android {
    //...
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

If necessary, in the same build.gradle you will need to increase minSdkVersion of defaultConfig up to 23 (currently default Flutter generator set to 16).
If necessary, in the same build.gradle you will need to increase compileSdkVersion and targetSdkVersion up to 33 (currently, the default Flutter generator set to 30).

For iOS

Add the following entries which allow your app to access the camera and microphone of your /ios/Runner/Info.plist file :
Uncomment the following line to define a global platform for your project in /ios/Podfile :

<key>NSCameraUsageDescription</key>
<string>$(PRODUCT_NAME) Camera Usage!</string>
<key>NSMicrophoneUsageDescription</key>
<string>$(PRODUCT_NAME) Microphone Usage!</string>

# platform :ios, '12.0'

For MacOS

Add the following entries to your /macos/Runner/Info.plist file that allows your app to access the camera and microphone:

<key>NSCameraUsageDescription</key>
<string>$(PRODUCT_NAME) Camera Usage!</string>
<key>NSMicrophoneUsageDescription</key>
<string>$(PRODUCT_NAME) Microphone Usage!</string>

Add the following entries to your /macos/Runner/DebugProfile.entitlements file that allows your app to access the camera, microphone, and open outgoing network connections:

<key>com.apple.security.network.client</key>
<true/>
<key>com.apple.security.device.camera</key>
<true/>
<key>com.apple.security.device.microphone</key>
<true/>

Add the following entries to your /macos/Runner/Release.entitlements file that allows your app to access the camera, microphone, and open outgoing network connections:

<key>com.apple.security.network.server</key>
<true/>
<key>com.apple.security.network.client</key>
<true/>
<key>com.apple.security.device.camera</key>
<true/>
<key>com.apple.security.device.microphone</key>
<true/>

Essential Steps to Implement Video Calling Functionality

Before diving into the specifics of screen sharing implementation, it's crucial to ensure you have VideoSDK properly installed and configured within your Flutter project. Refer to VideoSDK's documentation for detailed installation instructions. Once you have a functional video calling setup, you can proceed with adding the screen-sharing feature.

Step 1: Get started with `api_call.dart`

Before jumping to anything else, you will write a function to generate a unique meetingId. You will require an authentication token, you can generate it either by using videosdk-rtc-api-server-examples or by generating it from the VideoSDK Dashboard for development.

import 'dart:convert';
import 'package:http/http.dart' as http;

//Auth token we will use to generate a meeting and connect to it
String token = "<Generated-from-dashboard>";

// API call to create meeting
Future<String> createMeeting() async {
  final http.Response httpResponse = await http.post(
    Uri.parse("https://api.videosdk.live/v2/rooms"),
    headers: {'Authorization': token},
  );

//Destructuring the roomId from the response
  return json.decode(httpResponse.body)['roomId'];
}

api_call.dart

Step 2: Creating the JoinScreen

Let's create join_screen.dart file in lib directory and create JoinScreen StatelessWidget.

The JoinScreen will consist of:

Create Meeting Button: This button will create a new meeting for you.
Meeting ID TextField: This text field will contain the meeting ID, you want to join.
Join Meeting Button: This button will join the meeting, which you have provided.
Update the home screen of the app in the main.dart

import 'package:flutter/material.dart';
import 'api_call.dart';
import 'meeting_screen.dart';

class JoinScreen extends StatelessWidget {
  final _meetingIdController = TextEditingController();

  JoinScreen({super.key});

  void onCreateButtonPressed(BuildContext context) async {
    // call api to create meeting and then navigate to MeetingScreen with meetingId,token
    await createMeeting().then((meetingId) {
      if (!context.mounted) return;
      Navigator.of(context).push(
        MaterialPageRoute(
          builder: (context) => MeetingScreen(
            meetingId: meetingId,
            token: token,
          ),
        ),
      );
    });
  }

  void onJoinButtonPressed(BuildContext context) {
    String meetingId = _meetingIdController.text;
    var re = RegExp("\\w{4}\\-\\w{4}\\-\\w{4}");
    // check meeting id is not null or invaild
    // if meeting id is vaild then navigate to MeetingScreen with meetingId,token
    if (meetingId.isNotEmpty && re.hasMatch(meetingId)) {
      _meetingIdController.clear();
      Navigator.of(context).push(
        MaterialPageRoute(
          builder: (context) => MeetingScreen(
            meetingId: meetingId,
            token: token,
          ),
        ),
      );
    } else {
      ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
        content: Text("Please enter valid meeting id"),
      ));
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('VideoSDK QuickStart'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(12.0),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            ElevatedButton(
              onPressed: () => onCreateButtonPressed(context),
              child: const Text('Create Meeting'),
            ),
            Container(
              margin: const EdgeInsets.fromLTRB(0, 8.0, 0, 8.0),
              child: TextField(
                decoration: const InputDecoration(
                  hintText: 'Meeting Id',
                  border: OutlineInputBorder(),
                ),
                controller: _meetingIdController,
              ),
            ),
            ElevatedButton(
              onPressed: () => onJoinButtonPressed(context),
              child: const Text('Join Meeting'),
            ),
          ],
        ),
      ),
    );
  }
}

join_screen.dart

import 'package:flutter/material.dart';
import 'join_screen.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'VideoSDK QuickStart',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: JoinScreen(),
    );
  }
}

main.dart

Step 3: Creating the MeetingControls

Let's create meeting_controls.dart file and create MeetingControls StatelessWidget.

The MeetingControls will consist of:

Leave Button: This button will leave the meeting.
Toggle Mic Button: This button will unmute or mute the mic.
Toggle Camera Button: This button will enable or disable the camera.

MeetingControls will accept 3 functions in the constructor

onLeaveButtonPressed: invoked when the Leave button is pressed.
onToggleMicButtonPressed: invoked when the toggle mic button is pressed.
onToggleCameraButtonPressed: invoked when the toggle Camera button is pressed.

import 'package:flutter/material.dart';

class MeetingControls extends StatelessWidget {
  final void Function() onToggleMicButtonPressed;
  final void Function() onToggleCameraButtonPressed;
  final void Function() onLeaveButtonPressed;

  const MeetingControls(
      {super.key,
      required this.onToggleMicButtonPressed,
      required this.onToggleCameraButtonPressed,
      required this.onLeaveButtonPressed});

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
      children: [
        ElevatedButton(
            onPressed: onLeaveButtonPressed, child: const Text('Leave')),
        ElevatedButton(
            onPressed: onToggleMicButtonPressed, child: const Text('Toggle Mic')),
        ElevatedButton(
            onPressed: onToggleCameraButtonPressed,
            child: const Text('Toggle WebCam')),
      ],
    );
  }
}

meeting_controls.dart

Step 4: Creating ParticipantTile

Let's create participant_tile.dart file and create ParticipantTile StatefulWidget.

The ParticipantTile will consist of:

RTCVideoView: This will show the participant's video stream.

ParticipantTile will accept Participant in constructor

participant: participant of the meeting.

import 'package:flutter/material.dart';
import 'package:videosdk/videosdk.dart';

class ParticipantTile extends StatefulWidget {
  final Participant participant;
  const ParticipantTile({super.key, required this.participant});

  @override
  State<ParticipantTile> createState() => _ParticipantTileState();
}

class _ParticipantTileState extends State<ParticipantTile> {
  Stream? videoStream;

  @override
  void initState() {
    // initial video stream for the participant
    widget.participant.streams.forEach((key, Stream stream) {
      setState(() {
        if (stream.kind == 'video') {
          videoStream = stream;
        }
      });
    });
    _initStreamListeners();
    super.initState();
  }

  _initStreamListeners() {
    widget.participant.on(Events.streamEnabled, (Stream stream) {
      if (stream.kind == 'video') {
        setState(() => videoStream = stream);
      }
    });

    widget.participant.on(Events.streamDisabled, (Stream stream) {
      if (stream.kind == 'video') {
        setState(() => videoStream = null);
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(8.0),
      child: videoStream != null
          ? RTCVideoView(
              videoStream?.renderer as RTCVideoRenderer,
              objectFit: RTCVideoViewObjectFit.RTCVideoViewObjectFitCover,
            )
          : Container(
              color: Colors.grey.shade800,
              child: const Center(
                child: Icon(
                  Icons.person,
                  size: 100,
                ),
              ),
            ),
    );
  }
}

participant_tile.dart

Step 5: Creating the MeetingScreen

Let's create meeting_screen.dart file and create MeetingScreen StatefulWidget.

MeetingScreen will accept meetingId and token in the constructor.

meetingID: meetingId, you want to join
token: VideoSDK Auth token.

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:videosdk/videosdk.dart';
import './participant_tile.dart';

class MeetingScreen extends StatefulWidget {
  final String meetingId;
  final String token;

  const MeetingScreen(
      {super.key, required this.meetingId, required this.token});

  @override
  State<MeetingScreen> createState() => _MeetingScreenState();
}

class _MeetingScreenState extends State<MeetingScreen> {
  late Room _room;
  var micEnabled = true;
  var camEnabled = true;

  Map<String, Participant> participants = {};

  @override
  void initState() {
    // create room
    _room = VideoSDK.createRoom(
      roomId: widget.meetingId,
      token: widget.token,
      displayName: "John Doe",
      micEnabled: micEnabled,
      camEnabled: camEnabled
    );

    setMeetingEventListener();

    // Join room
    _room.join();

    super.initState();
  }

  // listening to meeting events
  void setMeetingEventListener() {
    _room.on(Events.roomJoined, () {
      setState(() {
        participants.putIfAbsent(
            _room.localParticipant.id, () => _room.localParticipant);
      });
    });

    _room.on(
      Events.participantJoined,
      (Participant participant) {
        setState(
          () => participants.putIfAbsent(participant.id, () => participant),
        );
      },
    );

    _room.on(Events.participantLeft, (String participantId) {
      if (participants.containsKey(participantId)) {
        setState(
          () => participants.remove(participantId),
        );
      }
    });

    _room.on(Events.roomLeft, () {
      participants.clear();
      Navigator.popUntil(context, ModalRoute.withName('/'));
    });
  }

  // onbackButton pressed leave the room
  Future<bool> _onWillPop() async {
    _room.leave();
    return true;
  }

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () => _onWillPop(),
      child: Scaffold(
        appBar: AppBar(
          title: const Text('VideoSDK QuickStart'),
        ),
        body: Padding(
          padding: const EdgeInsets.all(8.0),
          child: Column(
            children: [
              Text(widget.meetingId),
              //render all participant
              Expanded(
                child: Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: GridView.builder(
                    gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
                      crossAxisCount: 2,
                      crossAxisSpacing: 10,
                      mainAxisSpacing: 10,
                      mainAxisExtent: 300,
                    ),
                    itemBuilder: (context, index) {
                      return ParticipantTile(
                        key: Key(participants.values.elementAt(index).id),
                          participant: participants.values.elementAt(index));
                    },
                    itemCount: participants.length,
                  ),
                ),
              ),
              MeetingControls(
                onToggleMicButtonPressed: () {
                  micEnabled ? _room.muteMic() : _room.unmuteMic();
                  micEnabled = !micEnabled;
                },
                onToggleCameraButtonPressed: () {
                  camEnabled ? _room.disableCam() : _room.enableCam();
                  camEnabled = !camEnabled;
                },
                onLeaveButtonPressed: () {
                  _room.leave()
                },
              ),
            ],
          ),
        ),
      ),
      home: JoinScreen(),
    );
  }
}

meeting_screen.dart

CAUTION
If you get webrtc/webrtc.h file not found error at a runtime in iOS, then check the solution here.

TIP:
You can checkout the complete quick start example here.

Integrate RTMP Livestream Feature

RTMP is a popular protocol for live streaming video content from a VideoSDK to platforms such as YouTube, Twitch, Facebook, and others.

By providing the platform-specific stream key and stream URL, the VideoSDK can connect to the platform's RTMP server and transmit the live video stream.

VideoSDK allows you to live stream your meeting to a platform that supports RTMP ingestion just by providing the platform-specific stream key and stream URL, we can connect to the platform's RTMP server and transmit the live video stream.

VideoSDK also allows you to configure the livestream layouts in numerous ways, like by simply setting different prebuilt layouts in the configuration or by providing your own custom template to do the live stream according to your layout choice.

After installing videoSDK, you can unlock the power of live streaming by following these steps:

Start Livestream

startLivestream() can be used to start an RTMP live stream of the meeting, which can be accessed from the Room object. This method accepts two parameters:

1. outputs: This parameter accepts an array of objects that contains the RTMP url and streamKey of the platforms, you want to start the live stream.
2. config (optional): This parameter will define what the live stream layout should look like.

var outputs = [
  {
    url: "rtmp://a.rtmp.youtube.com/live2",
    streamKey: "<STREAM_KEY>",
  },
  {
    url: "rtmps://",
    streamKey: "<STREAM_KEY>",
  },
];
Map<String, dynamic> config = {
  // Layout Configuration
  layout: {
    type: "GRID", // "SPOTLIGHT" | "SIDEBAR",  Default : "GRID"
    priority: "SPEAKER", // "PIN", Default : "SPEAKER"
    gridSize: 4, // MAX : 4
  },

  // Theme of livestream
  theme: "DARK", //  "LIGHT" | "DEFAULT"
};

room.startLivestream(outputs,config:config);

Stop Live Stream

stopLivestream() is used to stop the meeting live stream which can be accessed from the Room object.

Event associated with Livestream

livestreamStateChanged: Whenever the livestream state changes, then livestreamStateChanged the event will trigger.

import 'package:flutter/material.dart';
import 'package:videosdk/videosdk.dart';

class MeetingScreen extends StatefulWidget {
  ...
}

class _MeetingScreenState extends State<MeetingScreen> {
  late Room room;

  @override
  void initState() {
    ...

    setupRoomEventListener();
  }

  @override
  Widget build(BuildContext context) {
    return YourMeetingWidget();
  }

  void setupRoomEventListener() {
  	//...
    room.on(Events.livestreamStateChanged, (String status) {
      //Status can be :: LIVESTREAM_STARTING
      //Status can be :: LIVESTREAM_STARTED
      //Status can be :: LIVESTREAM_STOPPING
      //Status can be :: LIVESTREAM_STOPPED
      log("Meeting Livestream status : $status");
    });
  }
}

Example

Let's create LiveStreamControls widget which will help to toggle RTMP LiveStream.

import 'package:flutter/material.dart';

class LiveStreamControls extends StatelessWidget {
  final String liveStreamState;
  final void Function() onToggleLiveStreamButtonPressed;

  const LiveStreamControls({
    super.key,
    required this.liveStreamState,
    required this.onToggleLiveStreamButtonPressed,
  });

  @override
  Widget build(BuildContext context) {
    return Wrap(
      children: [
        ElevatedButton(
            onPressed: onToggleLiveStreamButtonPressed,
            child: Text(liveStreamState == "LIVESTREAM_STOPPED"
                ? 'Start LiveStream'
                : liveStreamState == "LIVESTREAM_STARTING"
                    ? "Starting LiveStream"
                    : liveStreamState == "LIVESTREAM_STARTED"
                        ? "Stop LiveStream"
                        : liveStreamState == "LIVESTREAM_STOPPING"
                            ? "Stopping LiveStream"
                            : "Start LiveStream")),
      ],
    );
  }
}

Now, we will add LiveStreamControls widget in MeetingScreen after MeetingControls widget.
Also, we will listen to liveStreamStateChanged event when the meeting's livestream status changed.

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:videosdk/videosdk.dart';
import './participant_tile.dart';
import './livestream_controls.dart';

class MeetingScreen extends StatefulWidget {
  //...
}

class _MeetingScreenState extends State<MeetingScreen> {
  late Room _room;
  var micEnabled = true;
  var camEnabled = true;
  String liveStreamState = "LIVESTREAM_STOPPED";

  Map<String, Participant> participants = {};

  @override
  void initState() {
    // create room
    //...
  }

  // listening to meeting events
  void setMeetingEventListener() {
    // ...
	widget.room.on(
      Events.liveStreamStateChanged,
      (String status) {
        setState(
          () => liveStreamState = status,
        );
      },
    );
  }

  // onbackButton pressed leave the room
  Future<bool> _onWillPop() async {
    _room.leave();
    return true;
  }

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () => _onWillPop(),
      child: Scaffold(
        appBar: AppBar(
          title: const Text('VideoSDK QuickStart'),
        ),
        body: Padding(
          padding: const EdgeInsets.all(8.0),
          child: Column(
            children: [
              // ...,
              LiveStreamControls(
                onToggleLiveStreamButtonPressed: () {
                  if (liveStreamState == "LIVESTREAM_STOPPED") {
                    var outputs = [
                      {
                        "url": "<URL>",
                        "streamKey": "<Stream-Key>",
                      }
                    ];
                    var liveStreamConfig = {
                      'layout': {
                        'type': 'GRID',
                        'priority': 'SPEAKER',
                        'gridSize': 4,
                      },
                      'theme': "LIGHT",
                    };
                    widget.room.startLivestream(outputs,config: liveStreamConfig);
                  } else if (liveStreamState == "LIVESTREAM_STARTED") {
                    widget.room.stopLivestream();
                  }
                },
                liveStreamState: liveStreamState,
                ),
            ],
          ),
        ),
      ),
      home: JoinScreen(),
    );
  }
}

Custom Template

With VideoSDK, you can also use your own custom designed layout template to live stream the meetings. To use the custom template, you need to create a template, for which you can follow this guide. Once you have set up the template, you can use the REST API to start the live stream with the templateURL parameter.

Conclusion

Integrating RTMP livestream functionality into your Flutter video call app offers numerous benefits and opens up a wide range of use cases. With seamless RTMP support, users can engage in high-quality, real-time video streaming, enhancing communication and collaboration within your application. Embrace the versatility and scalability of RTMP in your Flutter app to elevate user engagement, foster meaningful connections, and provide a platform for diverse multimedia experiences.

Unlock the full potential of VideoSDK and craft seamless video experiences effortlessly. Sign up with VideoSDK today and receive 10,000 free minutes to propel your video app to the next level.