Building Real-Time Video with WebRTC

When building my Digital Whiteboard application, I needed a way for users to communicate while collaborating. WebRTC was the perfect solution for peer-to-peer video communication.

Why WebRTC?

• Real-time - No server bottleneck for media
• Peer-to-peer - Direct connection between users
• Free - No media server costs
• Built-in - Native browser support

WebRTC enables real-time communication directly between browsers without requiring a media server for streaming.

The Architecture

The basic flow is:

1. User A and B connect to a signaling server
2. They exchange connection information (SDP offers/answers)
3. ICE candidates are exchanged to find the best path
4. Direct WebRTC connection is established

Key Concepts

1. Signaling

Before peers can connect, they need to exchange connection information through a signaling server:

// Socket.io signaling
socket.emit('offer', {
  target: peerId,
  offer: peerConnection.localDescription
});

socket.on('answer', async (data) => {
  await peerConnection.setRemoteDescription(data.answer);
});

2. ICE Candidates

ICE (Interactive Connectivity Establishment) helps find the best path between peers:

peerConnection.onicecandidate = (event) => {
  if (event.candidate) {
    socket.emit('ice-candidate', {
      target: peerId,
      candidate: event.candidate
    });
  }
};

3. Media Streams

Accessing camera and microphone:

const stream = await navigator.mediaDevices.getUserMedia({
  video: true,
  audio: {
    echoCancellation: true,
    noiseSuppression: true
  }
});

// Add tracks to peer connection
stream.getTracks().forEach(track => {
  peerConnection.addTrack(track, stream);
});

Challenges Faced

| Challenge | Solution | |-----------|----------| | NAT Traversal | Used TURN servers for fallback | | Echo Cancellation | Enabled audio constraints | | Mobile Compatibility | Tested across devices | | Connection Drops | Implemented reconnection logic |

Result

The implementation allows seamless video chat while users collaborate on the whiteboard. Floating video feeds keep communication visible without blocking the canvas.

Conclusion

WebRTC is incredibly powerful for building real-time applications. While the initial setup has a learning curve, the result is a robust, low-latency communication system that works directly in the browser.