📹🎙️🦀 Rust Client SDK for LiveKit

Use this SDK to add real-time video, audio and data features to your Rust app. By connecting to a self- or cloud-hosted LiveKit server, you can quickly build applications like interactive live streaming or video calls with just a few lines of code.

Features

• Receiving tracks
• Publishing tracks
• Data channels
• Simulcast
• SVC codecs (AV1/VP9)
• Adaptive Streaming
• Dynacast
• Hardware video enc/dec
  • VideoToolbox for MacOS/iOS
• Supported Platforms
  • Windows
  • MacOS
  • Linux
  • iOS
  • Android

Crates

• livekit-api: Server APIs and auth token generation
• livekit: LiveKit real-time SDK
• livekit-ffi: Internal crate, used to generate bindings for other languages

When adding the SDK as a dependency to your project, make sure to add the necessary rustflags to your cargo config, otherwise linking may fail.

Also, please refer to the list of the supported platform toolkits.

Getting started

Currently, Tokio is required to use this SDK, however we plan to make the async executor runtime agnostic.

Using Server API

Generating an access token

use livekit_api::access_token;
use std::env;

fn create_token() -> Result<String, access_token::AccessTokenError> {
    let api_key = env::var("LIVEKIT_API_KEY").expect("LIVEKIT_API_KEY is not set");
    let api_secret = env::var("LIVEKIT_API_SECRET").expect("LIVEKIT_API_SECRET is not set");

    let token = access_token::AccessToken::with_api_key(&api_key, &api_secret)
        .with_identity("rust-bot")
        .with_name("Rust Bot")
        .with_grants(access_token::VideoGrants {
             room_join: true,
             room: "my-room".to_string(),
             ..Default::default()
        })
        .to_jwt();
    return token
}

Creating a room with RoomService API

use livekit_api::services::room::{CreateRoomOptions, RoomClient};

#[tokio::main]
async fn main() {
    let room_service = RoomClient::new("http://localhost:7880").unwrap();

    let room = room_service
        .create_room("my_room", CreateRoomOptions::default())
        .await
        .unwrap();

    println!("Created room: {:?}", room);
}

Using Real-time SDK

Connect to a Room and listen for events:

use livekit::prelude::*;

#[tokio::main]
async fn main() -> Result<()> {
    let (room, mut room_events) = Room::connect(&url, &token).await?;

    while let Some(event) = room_events.recv().await {
        match event {
            RoomEvent::TrackSubscribed { track, publication, participant } => {
                // ...
            }
            _ => {}
        }
    }

    Ok(())
}

Receive video frames of a subscribed track

...
use futures::StreamExt; // this trait is required for iterating on audio & video frames
use livekit::prelude::*;

match event {
    RoomEvent::TrackSubscribed { track, publication, participant } => {
        match track {
            RemoteTrack::Audio(audio_track) => {
                let rtc_track = audio_track.rtc_track();
                let mut audio_stream = NativeAudioStream::new(rtc_track);
                tokio::spawn(async move {
                    // Receive the audio frames in a new task 
                    while let Some(audio_frame) = audio_stream.next().await {
                        log::info!("received audio frame - {audio_frame:#?}");
                    }
                });
            },
            RemoteTrack::Video(video_track) => {
                let rtc_track = video_track.rtc_track();
                let mut video_stream = NativeVideoStream::new(rtc_track);
                tokio::spawn(async move {
                    // Receive the video frames in a new task 
                    while let Some(video_frame) = video_stream.next().await {
                        log::info!("received video frame - {video_frame:#?}");
                    }
                });
            },
        }
    },
    _ => {}
}

Examples

• basic room: simple example connecting to a room.
• wgpu_room: complete example app with video rendering using wgpu and egui.
• mobile: mobile app targeting iOS and Android
• play_from_disk: publish audio from a wav file
• save_to_disk: save received audio to a wav file

Motivation and Design Goals

LiveKit aims to provide an open source, end-to-end WebRTC stack that works everywhere. We have two goals in mind with this SDK:

1. Build a standalone, cross-platform LiveKit client SDK for Rustaceans.
2. Build a common core for other platform-specific SDKs (e.g. Unity, Unreal, iOS, Android)

Regarding (2), we've already developed a number of client SDKs for several platforms and encountered a few challenges in the process:

• There's a significant amount of business/control logic in our signaling protocol and WebRTC. Currently, this logic needs to be implemented in every new platform we support.
• Interactions with media devices and encoding/decoding are specific to each platform and framework.
• For multi-platform frameworks (e.g. Unity, Flutter, React Native), the aforementioned tasks proved to be extremely painful.

Thus, we posited a Rust SDK, something we wanted build anyway, encapsulating all our business logic and platform-specific APIs into a clean set of abstractions, could also serve as the foundation for our other SDKs!

We'll first use it as a basis for our Unity SDK (under development), but over time, it will power our other SDKs, as well.