liblinphone_flutter/README.md

liblinphone_flutter

A Flutter plugin that provides integration with the Linphone library for VoIP calls (audio and video) on Android and iOS platforms.

Third-Party Licenses

This project depends on the Linphone SDK, developed by Belledonne Communications, which is dual-licensed under the GNU Affero General Public License v3 (AGPLv3) and a proprietary commercial license.

This wrapper library itself is licensed under the MIT License. However, it is designed to work with the Linphone SDK, and therefore does not remove or replace the licensing requirements of Linphone.

Important

Any application using this plugin and linking against the Linphone SDK is subject to the terms of the AGPLv3, unless a commercial license for Linphone is obtained.

In practice, this means that applications using this plugin must comply with AGPLv3 requirements, which may include releasing the application's source code under a compatible license.

For proprietary or closed-source applications, you must obtain a commercial license for the Linphone SDK from Belledonne Communications.

Description

This plugin wraps the native Linphone SDK (liblinphone) and exposes a Dart API for making SIP-based voice and video calls in Flutter applications.

Features

• SIP account registration
• Audio and video calls
• Video streaming with local preview and remote view
• Call management (answer, hangup, toggle video/microphone)
• Registration and call state event streams

Platform Support

Platform	Status
Android	Supported
iOS	Supported

Requirements

• Flutter SDK >= 3.3.0
• Dart SDK >= 3.9.0-333.2.beta
• Linphone SDK (native dependency)

Installation

Add this to your pubspec.yaml:

dependencies:
    liblinphone_flutter: ^0.0.3

Or if you want to go with git:

dependencies:
    liblinphone_flutter:
        git:
            url: https://git.nuark.xyz/nuark/liblinphone_flutter.git
            ref: commit-hash

Then run:

flutter pub get

Platform-Specific Setup

Android

Ensure you have the necessary permissions in your AndroidManifest.xml:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />

iOS

The plugin requires access to the camera and microphone. Add the following to your Info.plist:

<key>NSCameraUsageDescription</key>
<string>Camera access is required for video calls</string>
<key>NSMicrophoneUsageDescription</key>
<string>Microphone access is required for audio and video calls</string>

Usage

Basic Example

import 'package:liblinphone_flutter/liblinphone_flutter.dart';

final liblinphone = LiblinphoneFlutter();

// Initialize
await liblinphone.checkPermissions();
await liblinphone.initialize();

// Register to SIP server
await liblinphone.register(
  'username',
  'password',
  'sip.server.com',
  5060,
);

// Listen to registration events
liblinphone.registrationEvents.listen((state) {
  print('Registration state: $state');
});

// Listen to call events
liblinphone.callEvents.listen((state) {
  print('Call state: $state');
});

// Make a video call
await liblinphone.makeCall('sip:recipient@sip.server.com', true);

// Answer incoming call
await liblinphone.answerCall();

// Toggle video during call
await liblinphone.toggleVideo();

// Toggle microphone
await liblinphone.toggleMicrophone();

// Hangup
await liblinphone.hangupCall();

// Send DTMF tone during a call
await liblinphone.sendDtmf('5'); // Send tone '5'
await liblinphone.sendDtmf('#'); // Send tone '#'
await liblinphone.sendDtmf('*'); // Send tone '*'

// Unregister and cleanup
await liblinphone.unregister();
await liblinphone.stop();

Video Views

For video calls, use the provided widgets to display local and remote video streams:

import 'package:liblinphone_flutter/widgets/local_view.dart';
import 'package:liblinphone_flutter/widgets/remote_view.dart';

// In your widget tree
Column(
  children: [
    // Remote video (full screen or large area)
    Expanded(
      child: RemoteView(),
    ),
    // Local video preview (picture-in-picture)
    SizedBox(
      height: 150,
      width: 100,
      child: LocalView(),
    ),
  ],
)

API Reference

Main Class: LiblinphoneFlutter

Methods

Method	Description
Future<bool> checkPermissions()	Checks and requests camera/microphone permissions
Future<bool> initialize()	Initializes the Linphone core
Future<bool> register(username, password, serverIp, serverPort)	Registers to a SIP server
Future<bool> unregister()	Unregisters from the SIP server
Future<bool> makeCall(callTo, isVideoEnabled)	Makes an outgoing call
Future<bool> answerCall()	Answers an incoming call
Future<bool> hangupCall()	Hangs up the current call
Future<bool> inCall()	Returns true if there is an active call
Future<CallType> callType()	Returns the type of the current call (audio/video)
Future<bool> toggleVideo()	Toggles video enabled state during a call
Future<bool> toggleMicrophone()	Toggles microphone muted state
Future<bool> sendDtmf(tone)	Sends a DTMF tone during a call (0-9, *, #, A-D)
Future<bool> stop()	Stops the Linphone core
Future<void> syncCurrentState()	Forces synchronization of current state

Event Streams

Stream	Type	Description
registrationEvents	Stream<RegistrationState>	Emits registration state changes
callEvents	Stream<CallState>	Emits call state changes

Enums

RegistrationState

• None - Not registered
• Progress - Registration in progress
• Ok - Successfully registered
• Cleared - Registration cleared
• Failed - Registration failed

CallState

• Idle - No active call
• IncomingReceived - Incoming call received
• OutgoingInit - Outgoing call initialized
• OutgoingProgress - Outgoing call in progress
• OutgoingRinging - Remote party ringing
• Connected - Call connected
• StreamsRunning - Media streams running
• Pausing - Call pausing
• Paused - Call paused
• Resuming - Call resuming
• Error - Call error
• End - Call ended
• And other states...

CallType

• Audio - Audio-only call
• Video - Video call
• Unknown - Call type unknown

License

This project is licensed under the MIT License.

Links

• Homepage
• Linphone Project