kerbcast

A from-scratch, high-performance oriented successor to OCISLY for streaming camera feeds to a browser. Hardware-accelerated H.264 over WebRTC, with full Hullcam VDS camera-type fidelity. Designed with Linux in mind, Windows and MacOS support is a little experimental.

What it does

• Streams HullcamVDS camera sources to a browser via the bundled kerbcast web UI or through @jonpepler/kerbcast, a TypeScript SDK
• Supports performance tweak options to keep fps reasonable through degrading resolution, framerate, and shedding render layers. By default, performance should feel vastly improved over the original OCISLY mod
• Introduces optional shaders for wind and re-entry FX (sorry, no Firefly support yet)
• HullcamVDS implementation enhancements:
• Honours each camera's cameraMode so B&W / CRT / night-vision variants look like they do in the in-game Hullcam GUI
• Introduces planned but never fully implemented panning options for turret cam and launch cam
• Supports a data channel for sending control data from clients (eg pan/zoom)
• Fixes and patches long term issues on Linux

How it does it

• Captures KSP Hullcam VDS camera feeds inside the game via AsyncGPUReadback, with zero stall on the game's main thread
• Encodes them in an out-of-process 'sidecar': software H.264 (OpenH264) as the fallback, with hardware H.264 on Linux / Steam Deck (libva), and NVENC (Windows). VideoToolbox (macOS) is stubbed pending implementation
• Streams them out as WebRTC media tracks, with adaptive bitrate, congestion control, and packet loss recovery for free
• Renders cameras only when a peer is subscribed, so no idle CPU work and no in-game UI required

Status: Initial Release - expect bugs

Kerbcast is just becoming ready for general consumption. It supports Linux, with limited testing on Windows and MacOS.

Issues and PRs are welcome, particularly if you'd like to 'adopt' macOS or Windows support.

Installing kerbcast

Each GitHub Release also carries these steps in its notes - if anything here disagrees with the notes on the release you downloaded, the release notes win.

Requirements

• Kerbal Space Program 1.12.x
• Hullcam VDS Continued (required - kerbcast streams Hullcam camera parts)
• Harmony 2 (required - kerbcast uses Harmony to patch into KSP at runtime)
• A WebRTC-capable browser on the viewing device (any current Firefox, Chrome, Safari, or Edge)

Steps

1. Use CKAN and skip to step 4, or: Download kerbcast-vX.Y.Z.zip from the releases page or from SpaceDock.
2. Extract it into your KSP install so that GameData/Kerbcast/ exists (the zip already contains the GameData/ folder - extract at the KSP root).
3. Install Hullcam VDS Continued if you haven't already.
4. Start KSP and launch a flight with one or more Hullcam camera parts on the vessel.
5. On the same machine, open http://127.0.0.1:8088 in a browser. The bundled web page lists the vessel's cameras and starts streams when you click them.

Windows: the first time the sidecar launches, Windows may warn about running it. It's safe to approve; you'll only see this on first run.

To watch from another device, create GameData/Kerbcast/PluginData/settings.cfg containing:

Settings
{
  BindAddress = 0.0.0.0   // or your LAN IP
}

then browse to http://<ksp-machine-ip>:8088 from the other device.

There is no authentication. Anyone who can reach that address can watch the camera feeds. Only bind beyond localhost on a network you trust.

Configuration

Edit GameData/Kerbcast/settings.cfg like any other KSP mod config. Every field is commented inline: bind address/port, capture resolution, stream bitrate, adaptive-performance ceilings, Hullcam filter and atmospheric-FX toggles, and per-camera overrides.

Updates re-extract GameData/Kerbcast/, so direct edits to that file are lost on the next version. To keep changes across updates, put only the keys you're changing in GameData/Kerbcast/PluginData/settings.cfg instead.