lsl_bindings 0.0.1

A plugin for interacting with the Lab Streeming Layer

LSL Bindings

Low-level Dart bindings to the Lab Streaming Layer (LSL) C API.

This package provides direct access to the native LSL interface via Dart FFI and is intended for advanced users who require fine-grained control over streaming or receiving LSL data in Dart or Flutter applications.

If you're looking for a higher-level, idiomatic Flutter API for working with LSL, consider using lsl_flutter, which builds on top of this package.

Features

• Direct Dart FFI bindings to the LSL C API
• Cross-platform support: macOS, iOS (via .xcframework), Windows, and Android

Getting started

1. Add dart:ffi as a dependency, as it is needed for memory management and type conversion.

2. Add the plugin to your pubspec.yaml (or flutter pub add lsl_bindings):

dev_dependencies:
  ffi: ^2.1.3
dependencies:
  lsl_bindings: ^1.0.0

Usage

import 'package:lsl_bindings/lsl_bindings.dart';

final streamInfo = lslBindings.lsl_create_streaminfo(
  "Test stream".toNativeUtf8().cast<Char>(),
  "EEG".toNativeUtf8().cast<Char>(),
  4,
  256,
  lsl_channel_format_t.cft_double64,
  "Source id".toNativeUtf8().cast<Char>());

Android

The minimum SDK version must be set to 26 in app/build.gradle. This is due to the logging library used by LSL, Loguru.

// app/build.gradle
minSdk = 26

Although not due to this plugin, users may encounter the problem mentioned here when creating a new project for Android. To avoid, make the following change in your settings.gradle file:

- includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")
+ includeBuild(file("$flutterSdkPath/packages/flutter_tools/gradle").toPath().toRealPath().toAbsolutePath().toString())

The AndroidManifest.xml must contain

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />

iOS

Minimum deployment target must be set to at least 14

# Uncomment this line to define a global platform for your project
platform :ios, '14.0'

The Info.plist for applications using the plugin must specify a reason for accessing the local network

<key>NSLocalNetworkUsageDescription</key>
<string>This app needs local network access to discover data streams.</string>

macOS

To develop an application that utilises UDP multicast, special permission is required from Apple. Therefore, when developing within a sandbox for macOS applications LSL will not be able to discovers streams on the network. So it is best to simply remove the sandbox from the app.