Meh Virtual Webcam

Architectural Summary

The project is a cross-platform virtual webcam that allows you to use your phone's camera as a high-quality video source on your computer. It is implemented through a client-server architecture consisting of a native mobile app (client) and a lightweight desktop app (server), designed to operate exclusively on a local network for maximum performance and privacy.

1. Desktop Application (Server)

This lightweight server application runs on the user's computer. Its purpose is to receive the video stream and create the virtual webcam device.

• Framework: Electron
• UI: HTML, CSS, JavaScript/TypeScript
• Core Logic: A Native Node.js Addon (in C++) will be created to handle all high-performance media tasks.

2. Mobile Application (Client)

This app runs on the user's phone, acting as the video source.

• Framework: Kotlin/Compose Multiplatform
• Function: Captures video from the phone's camera and streams it via WebRTC to the desktop server.

3. Video Streaming & Virtual Camera (The Native Addon)

This is the high-performance engine inside the desktop application. It's a single, unified native module that handles the entire video pipeline.

• Core Technology: GStreamer (embedded within the C++ addon).
• Architecture: A GStreamer pipeline will be constructed in the C++ code to manage the WebRTC stream and output to the virtual camera.
• Local Network Constraint: The WebRTC connection is strictly confined to the local network. This eliminates the need for external STUN or TURN servers, simplifying the configuration and guaranteeing that video data never leaves the user's LAN.

4. Signaling and Discovery

This subsystem enables the desktop server and mobile client to find each other automatically and negotiate the local video connection.

• Discovery Technology: mDNS (Bonjour/Zeroconf).
• Signaling Technology: WebSockets.
• Workflow:
  1. The apps use mDNS to automatically discover each other's local IP address and port.
  2. A WebSocket connection is established directly between the two local IPs.
  3. The WebRTC session negotiation occurs over this WebSocket. Crucially, only local network IP addresses (e.g., 192.168.x.x) are exchanged as ICE candidates, forcing the video stream to stay on the high-speed local network.
• Libraries:
  • Desktop: bonjour-service and ws npm packages.
  • Android: Native NsdManager API.
  • iOS: Native Network framework (Bonjour).