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Lightbridge

Live Input (Syphon)

On macOS, Lightbridge can receive live video from another running app — Resolume, OBS, TouchDesigner, MadMapper, VDMX, or anything that publishes a Syphon server — and treat it as a source in your chain. The incoming frames run through everything else: effects, transforms, blend modes, the palette, opacity, modulation.

This uses Syphon, the macOS standard for sharing GPU frames between apps with no copy to disk and no measurable latency. It is macOS only. (Windows Spout is not supported yet.)

Add a live input

  1. Add the Syphon / Spout source (in the Inputs category). Before you pick a server it shows a placeholder test card.
  2. In the source’s panel, open the server picker. It lists every Syphon server currently running on your Mac — shown as App — Server name (e.g. Resolume Arena — Composition).
  3. Pick one. The live feed appears immediately and composites like any other source.
  4. Nothing in the list? Click the refresh (↻) button — the other app has to be publishing for it to appear (see below). Use the × to disconnect.

The chosen server is saved with your show and reconnects automatically when you reopen the file or switch to a set that uses it — you don’t have to open the panel again.

Publishing a server from common apps

Lightbridge is the receiver. The other app has to publish a Syphon server first:

  • Resolume Arena / Avenue — Output → Syphon (or the Syphon output in preferences). Resolume publishes its program output.
  • OBS Studio — install the Syphon output plugin, then enable a Syphon server for the program or a specific source.
  • TouchDesigner — drop a Syphon Spout Out TOP and wire your network into it.
  • MadMapper — enable Syphon output in preferences.
  • VDMX, CoGe, Modul8, Isadora — each has a Syphon output option.
  • Another copy of Lightbridge — turn on Syphon output for an output window (see the Output guide) and receive it elsewhere.

What you can do with it

A live input is a normal source, so:

  • Stack it under or over other sources with any blend mode and opacity.
  • Run effects on it — feedback, kaleidoscope, bloom, glitch, anything in the chain.
  • Apply transforms (position, scale, rotation, zoom) at the chain level.
  • Drive its Brightness with an LFO, an audio band, MIDI, or a button.
  • Put several live inputs in one chain — each picks its own server.

The frame is aspect-fit into the viewport (letterboxed / pillarboxed to preserve the source’s shape) and composited with premultiplied alpha, matching the rest of the renderer.

Troubleshooting

The server isn’t in the list. The other app must be actively publishing a Syphon server. Confirm it’s running and its Syphon output is enabled, then click refresh (↻). Brand-new servers can take a moment to be announced.

I see the test card, not the feed. That means no server is selected (the placeholder), or the one you picked stopped publishing. If the publishing app quits normally or disables its Syphon output, the source falls back to the placeholder and reconnects on its own when the server comes back.

The feed froze on the last frame. If the publishing app crashed or was force-quit, macOS can’t always tell Lightbridge the server is gone, so the last received frame may stay frozen. Re-pick the server from the list (or toggle the source off and on) to recover once the app is running again.

The feed is there but I want it brighter/dimmer. Use Brightness in the source’s Display group — it’s bindable like any parameter.

Nothing shows up on Windows. Live input is macOS Syphon only for now. Windows Spout input is not implemented.

Can I send Lightbridge’s output back out the same way? Yes — that’s the other direction. See the Output guide for Syphon output per display.