Shared Concepts

Streaming with OBS, Twitch & YouTube

Send Beamtracer visuals to OBS Studio — chrome-less Browser Source, Stream to OBS (WebRTC), window capture fallback, and stream audio routing.

Beamtracer’s Output stage (Cast icon in the Visualizer and Oscilloscope headers) is the product path for live destinations. Window capture remains a solid fallback.

  1. Open Visualizer (/viz) or Oscilloscope (/scope) and start your audio.
  2. Click the Cast icon in the top header (title: “Output stage — Cast / send to OBS”).
  3. Choose a destination card:
DestinationWhat it does
Projector windowA chrome-less window mirroring the live stage on this computer — no encoding, no network, no added latency. The local projector / second-display path.
Send to OBSChrome-less stage URL for an OBS Browser source (?obs=1)
Stream to OBSEncodes the stage in Chrome and sends video to a private /obs page you open in OBS (best when CEF/WebGPU is flaky)
Send to EcammOperator guides for window capture or OBS → NDI → Ecamm
Send via WHIPRFC 9725 publish to your media server
Send via CastGoogle Cast when the destination is available; the card shows its current availability
Send via AirPlaySafari Remote Playback to Apple TV / AirPlay displays

Shared options for the encode destinations: Resolution (e.g. 1080p), FPS hint, Transparent background, Autostart audio. The Projector window has no encode options — it mirrors the stage at the canvas's own size.

Projector window (local second display)

The zero-latency path for a projector or DJ screen connected to the same computer. Click Open projector window: a chrome-less window opens showing only the live stage. With more than one display connected, Chrome asks once for window management permission and the window then opens directly on the other display; one click inside it goes fullscreen and even the hint text disappears. The window keeps running when you close the Output stage dialog, and closing the window ends the mirror. If it reads "WAITING FOR THE STAGE", keep the BeamTracer tab open and visible.

Send to OBS (Browser Source)

  1. In Output stage → Send to OBSCopy for OBS (URL + Custom CSS + checklist).
  2. In OBS: Sources → Add → Browser.
  3. Paste the URL. Set Width × Height to the same size as your OBS canvas (e.g. 1920×1080).
  4. Paste Custom CSS into the Browser source Custom CSS field.
  5. Prefer OBS 30+ with Browser Source hardware acceleration enabled.

The chrome-less URL looks like:

https://your-host/viz?obs=1&autostart=1&w=1920&h=1080&res=1920x1080&v=<visualizerId>

(?obs=1 hides the Beamtracer header and side panels.)

Audio: Autostart tries to play in the OBS Browser Source (CEF may still block until interaction). For stream audio, also add Desktop Audio in OBS, or use Stream to OBS for video-only while Desktop Audio carries the music.

Stream to OBS (WebRTC)

Use when the Browser Source is black or WebGPU fails inside OBS CEF:

  1. Sign in to BeamTracer, then choose Output stage → Stream to OBSCreate output linkCopy for OBS.
  2. Add the copied URL as an OBS Browser source. The receiver does not need to sign in.
  3. Press Start sending in Beamtracer.

You can have up to two active output links per account. If you reach the limit, stop an existing output before creating another link, or wait for its one-hour expiry. Keep each output link private.

Beamtracer sends video from Chrome; OBS plays the received stream.

Window capture fallback

If you prefer not to use Browser Source:

  1. Press F (fullscreen) so panels hide, or use Detached Controls in Performer mode.
  2. In OBS: Sources → Window Capture (macOS: “macOS Screen Capture”) and pick the Beamtracer window.

Performer companion window

Performer mode still offers a clean companion window at /viz/performer-output with dedicated pulse visuals. That path is not a full canvas mirror — for the real visualizer, use Output stage or fullscreen + window capture.

Stream audio

  • Desktop audio (easiest): whatever Beamtracer plays also plays through the system output; OBS Desktop Audio carries it.
  • Tab capture / DJ setups: see Audio Input Setup.

Tips

  • Match resolution to your stream canvas (1920×1080 is the default Output stage preset).
  • If an OBS source looks stale after a BeamTracer update, right-click the OBS Browser source → Refresh cache of current page.
  • Chrome or Edge with WebGPU gives the best performance (Browser Support).