📻 chanson.live

⚠ Extremely Alpha

This is something I threw together over an idle weekend. There's a bunch of improvements I'd like to make:

• improve the hacky ffmpeg subprocess to convert the audio to an RTP stream
• useContext for the actual wss connection via Remix
• add a queue on the website
• ability to request music on the website

You can find a live example here: https://radio.obviy.us/

If nobody's playing music via the Telegram bot, it'll play from a list of previously played songs. There are plans to make a functional web UI someday™.

Architectural Overview

sequenceDiagram
    Client->>Mediasoup Server: wss://
    Client->>Telegram Bot: Play Song
    Telegram Bot->>Command Server: Download, Queue and Stream
    Command Server->>ffmpeg subprocess: -acodec libopus -f tee [rtp]
    ffmpeg subprocess->>Mediasoup Server: RTP Stream
    Mediasoup Server->>Client: RTC Stream

• All music queue logic and commands are encapsulated within the Telegram bot
• The Telegram script downloads the requested song off of YouTube and queues a ffmpeg process
• Mediasoup client-server communication happens over WebSockets

Orchestration Flow

sequenceDiagram
    autonumber
    Mediasoup Client->>+Mediasoup Server: SocketMessages.CONNECTION
    Mediasoup Server->>Mediasoup Client: SocketMessages.WELCOME
    Mediasoup Server->>-Mediasoup Client: SocketMessages.METADATA
    Note over Mediasoup Client,Mediasoup Server: Initial Handshake Complete
    loop every song
        Mediasoup Server->>Mediasoup Client: SocketMessages.PRODUCER_STARTED
        Mediasoup Client->>Mediasoup Server: SocketMessages.CONSUME
        Mediasoup Client->>Mediasoup Server: SocketMessages.GET_ROUTER_RTP_CAPABILITIES
        Mediasoup Server->>Mediasoup Client: SocketMessages.GET_ROUTER_RTP_CAPABILITIES
        Mediasoup Client->>Mediasoup Client: Load Device
        Mediasoup Client->>Mediasoup Server: SocketMessages.CREATE_CONSUMER_TRANSPORT
        Mediasoup Server->>Mediasoup Server: Create WebRTC Transport
        Mediasoup Server->>+Mediasoup Client: SocketMessages.CREATE_CONSUMER_TRANSPORT
        Mediasoup Server->>Mediasoup Client: SocketMessages.CONNECT
        Mediasoup Client->>Mediasoup Server: SocketMessages.CONNECT_CONSUMER_TRANSPORT
        Mediasoup Client->>-Mediasoup Client: Play Audio
    end

History

I previously used Liquisoup + Icecast for this project but everyone complained about the 2 minute long wait to listen to the song they had just queued up. I attempted another solution with nginx + HLS chunks but that could only get me as close as < 15s.

This WebRTC certainly will not scale for a high number of users. If your intent is to scale to millions of concurrent listeners I can highly recommend what radiofrance uses (Liquidsoap + Icecast).

Why?

Why not? For fun! Though the inspiration for this project came about when a friend wanted to listen to the new Taylor Swift album together, in real time.