Bifrost

Use a phone as an OBS webcam source without a native phone app or a media relay.

The phone opens a browser camera page. The computer opens a receiver page, or the clean OBS page in an OBS Browser Source. OBS Virtual Camera can then expose that source to video-call apps.

OBS setup

1. Open / in a normal desktop browser.
2. Add a new Browser Source in OBS.
3. Copy the OBS URL from the receiver page into the Browser Source URL field.
4. Set the Browser Source size to the OBS canvas size you want, for example 1920x1080 for Full HD or 3840x2160 for 4K.
5. Scan the QR code with the phone and allow camera access.
6. Once OBS is connected, the normal receiver page will say that OBS is handling the camera stream. You can close that receiver page; keep the phone page and OBS Browser Source open.
7. Start OBS Virtual Camera and select it as the webcam in your video-call app.

The /obs page renders only the incoming video. It does not show controls, debug UI, QR codes, or links, so it is safe to capture directly in OBS.

Goals

• Stream phone camera video to a computer with WebRTC.
• Keep media local and peer-to-peer over the LAN or USB-tethered network.
• Use Cloudflare Workers only for hosting, room creation, and WebRTC signaling.
• Provide an OBS-friendly /obs mode that renders only the video.
• Show actual camera and receiver properties instead of assuming fixed limits.
• Make direct-path verification visible through ICE candidate and WebRTC stats.
• Fail rather than use STUN, TURN, a relay, SFU, media server, Cloudflare Realtime, or Cloudflare Stream.

Non-goals

• No native iOS or Android app.
• No DroidCam, Iriun, Camo, or other webcam app dependency.
• No multi-viewer broadcast mode.
• No remote internet streaming of camera media.
• No fallback to relay infrastructure when direct local WebRTC cannot connect.

Usage

Create a local .env with a private signing secret:

printf 'ROOM_SIGNING_SECRET=%s\n' "$(openssl rand -base64 32)" > .env

pnpm run build
pnpm run dev

Open:

• / on the computer to create a room, show the phone QR code, and preview the stream while OBS is absent.
• /camera?room=... on the phone browser.
• /obs?room=... in OBS Browser Source for the clean video-only receiver. When OBS connects, it becomes the active receiver without requiring the / page to close.

For deployment, configure the same required secret in Cloudflare before deploying:

pnpm exec wrangler secret put ROOM_SIGNING_SECRET
pnpm exec wrangler deploy

Quality

pnpm run check
pnpm run lint
pnpm run format
pnpm run format:check