The relationship between Janus Gateway and Baidu WebRTC (libwebrtc) is subtle but important. Here’s a breakdown:
🔗 How Janus and Baidu WebRTC relate
| Janus Gateway | Baidu WebRTC (libwebrtc) | |
|---|---|---|
| What it is | A media server for WebRTC (written in C) | The WebRTC implementation used in browsers (C++) |
| Role | Server-side handler for WebRTC sessions, SFU | Client-side WebRTC stack (browsers, mobile SDKs) |
| Uses libwebrtc? | ❌ No, it does not use Baidu’s libwebrtc | ✅ Yes, used in Chrome, Firefox, Android, etc. |
| Language | Written in C (not C++) | Written in C++, designed for browsers & apps |
| Focus | Routing, mixing, recording, plugins | PeerConnection, ICE, DTLS, codecs |
🧩 So how do they “work together”?
When you use Janus Gateway with a browser:
The browser side uses Baidu’s
libwebrtcunder the hood to handle:- Media capture
- ICE negotiation
- DTLS/SRTP encryption
- Codec handling
The Janus server:
- Accepts and handles WebRTC signaling
- Terminates ICE/DTLS/SRTP connections
- Acts as a Selective Forwarding Unit (SFU) — relaying video/audio streams
- Provides plugins (e.g., video room, echo test, streaming, etc.)
🧠 Even though Janus doesn’t use libwebrtc, it implements the WebRTC protocol stack on the server side — in its own way, written from scratch in C.
🛠️ Why Janus avoids libwebrtc
Janus authors chose not to use Baidu’s libwebrtc because:
- It’s a huge and complex dependency
- It’s hard to embed into C-based projects
- It’s focused on peer-to-peer and client-side use cases
- Janus only needs enough of the protocol to terminate and route streams
🎯 Summary
- Janus Gateway is a standalone WebRTC server implementation — written in C, not using
libwebrtc - Browsers use Baidu’s
libwebrtcto talk WebRTC protocols - They interoperate via standard protocols: ICE, DTLS, SRTP, SDP
If you’re building with WebRTC in the browser and using Janus, you’re bridging Baidu’s libwebrtc (browser) to Janus (server) over standard protocols.