Castline

Send a phone camera, webcam or screen to OBS with one link, and run a whole team's feeds from one clean control panel. Status: built and in private testing. Public release coming soon (maybe).

Why I built it

For tournament broadcasts and scrims I've relied on VDO.Ninja for years. It's free, open source and peer to peer, so a player's camera or screen reaches the stream with almost no delay. It's also easy to get lost in: on a phone, switching cameras or changing the mic means digging through menus, and running a room of players means remembering URL parameters.

I wanted the same engine behind an app my players could open without a tutorial. I also wanted a backup plan in case the public service ever goes away.

What it does

Go live in one tap. Check your camera and mic first, then share your camera, screen or mic only. You get a link to paste into OBS as a Browser Source.
Phone-first controls. One button flips between the front and back cameras without dropping the stream. A Sources sheet shows every camera, screen, mic and quality option as a big button.
Host a room. Players join from an invite link or QR code. The host sees every feed and can mute a player, turn their camera off, set their volume, message them, remove them, or copy a solo link for OBS.
On-air switching. Mark who is on air. OBS gets two scene links: one with everyone, and one with on-air players only.
Works across borders. Each room picks a signaling network, including a China-friendly one, and the invite link carries that choice. Players in mainland China connect to the same server as everyone else without any setup.
Installs like an app. It works on iPhone, Android, Mac and Windows, with dark and light themes.

Castline on a phone: the home screen, a live camera with the control dock, and the Sources sheet with camera, screen, microphone and quality choices — On a phone: home, live with the control dock, and the Sources sheet.

Castline host control panel: a grid preview of four player feeds, invite and OBS scene links, and a guest list with mic, camera, on-air, solo link and volume controls — The host panel: the OBS preview on the left, and every player's controls on the right.

How it works

Castline is a new interface, not a new video engine. The video still runs on VDO.Ninja's open-source WebRTC engine, embedded in the page and controlled through its documented iframe API. Video goes straight between browsers and never passes through my server. I also keep a self-hosted copy of the engine and its signaling server as a backup.

Status

Castline is finished and in private testing with a small group. It isn't open to the public yet. When it is, it'll be linked here. Coming soon (maybe).

Castline is an independent project and isn't affiliated with or endorsed by VDO.Ninja. VDO.Ninja is by Steve Seguin and licensed under AGPL-3.0.