Caution! Vibe Coded

Multi-M/E — Multiple Mix/Effects for OBS

An OBS plugin that adds extra mixing layers (M/E banks) to OBS — like a hardware video switcher (ATEM / TriCaster / Ross / Sony). Each bank has its own program/preview bus with cut/auto transitions and is operated through a control-surface dock.

Status: Beta / work in progress. Video mixing only (no separate audio mix — audio keeps running through the normal OBS mixer). Developed/tested with OBS 31 / Qt 6.8 (requires OBS 30+).

OBS' main canvas + Studio Mode is effectively M/E 1 — this plugin provides M/E 2 … n.

Features

• M/E bank as a source ("Multi-M/E — Mix/Effects (Re-entry)"): each instance is its own mixing layer; its output can be placed in main scenes like any other source ("re-entry").
• Program/preview bus from OBS scenes, CUT (immediate) and AUTO (transition); on a take PGM/PVW swap (ping-pong like at a switcher).
• Transitions: Fade / Swipe / Slide with adjustable duration.
• Control-surface dock: bank selection, PGM/PVW tally (red/green), preview-bus buttons, CUT/AUTO, transition type + duration, and a REC button. The bank/scene list updates automatically; the last selected bank is remembered.
• Multiview per bank: a dedicated PGM/PVW projector (window or fullscreen) via Tools → Multi-M/E Multiview, with 8 scene previews (click = preview, double-click = auto, Esc closes) — like the native OBS multiview.
• Own file recording per bank: record a bank's mixed output to its own file (separate encoder/bitrate), with the OBS main audio track for easy sync with the main recording.
• Remote control via obs-websocket (vendor multi-me): set preview/program, trigger CUT and AUTO, start/stop recording — e.g. with Bitfocus Companion. Bank by name or UUID.
• Hotkeys per bank (Settings → Hotkeys: "Multi-M/E: Cut" / "Multi-M/E: Auto/Take" and "Preview Input 1…12").
• Multiple banks = simply add more source instances.

Installation (beta)

Windows

1. Unzip the plugin archive.
2. Copy the multi-me folder into the OBS plugin directory so the structure looks like:

   %APPDATA%\obs-studio\plugins\multi-me\bin\64bit\multi-me.dll
   %APPDATA%\obs-studio\plugins\multi-me\data\...
   

   Tip: type %APPDATA% into the Explorer address bar → it lands in C:\Users\<name>\AppData\Roaming. (No administrator needed.)
3. Start OBS. Show the dock via Docks → Multi-M/E.

macOS

Copy multi-me.plugin to ~/Library/Application Support/obs-studio/plugins/, start OBS.

Linux

Unpack the package contents into ~/.config/obs-studio/plugins/multi-me/ (bin/64bit/multi-me.so + data/), start OBS. See limitations below.

Usage

1. In a scene, Add source → "Multi-M/E — Mix/Effects (Re-entry)".
2. Open Docks → Multi-M/E and select the bank in the dock.
3. Click a scene in the preview bus (= PVW), then CUT or AUTO — the bank output (the re-entry source in your main scene) switches accordingly.

Control via obs-websocket / Bitfocus Companion

Enable obs-websocket (Tools → WebSocket Server Settings). The banks are controlled through the vendor multi-me via CallVendorRequest (bank = source name or UUID):

Request	Data	Effect
set_preview	{ bank, scene }	scene into the bank's preview
set_program	{ bank, scene }	scene straight to program (hard cut)
cut	{ bank }	Cut (PVW → PGM)
auto	{ bank }	Auto-Take (transition)
start_record / stop_record	{ bank }	start/stop the bank's file recording
get_banks	{ }	list of all banks (incl. ready-made hotkey IDs)
get_state	{ bank }	{ program, preview, in_transition, kind, duration, recording, rec_file }

In Bitfocus Companion (OBS Studio module): action Custom Vendor Request → vendor multi-me, request type e.g. cut, request data {"bank":"My M/E"}. Alternatively, per bank via Trigger Hotkey by ID (CUT/AUTO/"Preview Input 1…12").

📖 Full Companion guide (requests, hotkey IDs, feedback/tally): docs/companion.md.

Known limitations

• Linux: the multiview projector needs X11 or XWayland. It renders on X11 and XWayland sessions; under a native Wayland session the multiview window stays blank (a warning is logged). Everything else (dock, bus, CUT/AUTO, hotkeys, recording, WebSocket) works regardless. Workaround on native Wayland: place the bank source in a scene and use a normal OBS projector, or start OBS under XWayland.
• No separate audio mix (by design): audio keeps running through the normal OBS mixer. (The per-bank file recording does include the OBS main audio track.)
• Tested primarily on macOS; Windows/Linux are built but exercised less thoroughly.

In my Testing it could handle: 1080p Project 25fps Project

• 8 1080p Videos Playing
• 5 M/E (4x The Plugin)
• All Recording with the HEVC Hardware Encoder at 6000mpbs CBR.
• Companion triggering Auto every 2 Seconds with Different effects and Inputs on all Channels.
• It couldn't quite handle 50p with all 5 Channels on my M1 Pro Macbook Pro

Building from source

The project is based on the OBS Plugin Template.

• Windows / macOS / Linux (official): via GitHub Actions (.github/workflows) or locally with the template build (CMake; Windows: Visual Studio 2022, macOS: Xcode).
• macOS quick, without full Xcode: ./dev/build.sh (isolated Ninja dev build) — see dev/README.md.

Project goals, architecture and progress: see PROJEKT.md (in German).

License

GPL v2 or later — see LICENSE.