Multiviewer

A Multiviewer displays multiple video sources side by side on a single screen, functioning as a command centre for monitoring inputs and scenes during a live show. It is a feature of the Switcher input, which hosts and renders it. Composer's Multiviewer can show up to 13 sources at once, supports up to 4 overlays per multiviewer, indicates Program / Preview state with tally lights, and is fully drivable from Connectors, the Script Engine, the HTTP API, or the Companion app + Stream Deck.

Setup

1. Add a Switcher input from the Inputs & Scenes tab.
2. Add the Switcher input to a scene as a layer.
3. In the layer's Input Layer dropdown, choose Multiview (one of the Switcher's four outputs — see below).

Switcher outputs

A Switcher isn't a single image — it produces four separate outputs, and the layer's Input Layer dropdown picks which one that layer renders:

Because the selection is per layer, one Switcher can feed several layers at once, each tapping a different output — for example route Output to a layer going to your program target while a Multiview layer drives a confidence monitor, all from the same Switcher.

Configuration

The Multiviewer's properties expose:

• Create Multiview — toggles the multiviewer on the chosen Switcher input.
• Multiview Layout — choose 4 inputs (1×4), 8 inputs (2×4), or 13 inputs (5+4+1×4). All layouts show the large Program / Preview pair at the top; the 4-input layout adds a single row of 4 monitors, the 8-input layout a 2×4 block of 8, and the 13-input layout adds a third row for 13.
• Activate tally — colours each tile red for Program and green for Preview.
• Activate VU-meters — overlays per-tile VU meters. In the 13-input layout only cells 1–9 show meters; cells 10–13 are too small to draw them.
• PGM Vu-meter source — names which channel feeds the Program VU.
• Input 1 … Input 13 — assign sources to tiles. The pipe character | lets you set a display alias separate from the input name (Camera1|CAM 1).

The 8-input layout:

The 13-input layout:

Overlays

Up to four overlays can be configured on each multiviewer with fade transitions of 0–5000 ms. Each overlay exposes three commands:

• Fade in/out — toggles the overlay: fades it in if hidden, out if visible, using the configured fade duration.
• Show — instant on.
• Hide — instant off.

Important — overlay resolution

Overlays must match the resolution of the Switcher input feeding the multiviewer; mismatched resolutions cause scaling artefacts and visible alignment problems.

Using the Multiviewer

Once configured, the Multiviewer is driven from four places:

• Connectors — the recommended path for external automation, control surfaces, and broadcast-board integration.
• Script Engine — programmatic control inside the project.
• HTTP API — every Multiviewer property is exposed over the generic HTTP API. Read a value with /api/getproperty, change one with /api/setproperty (e.g. MultiViewLayout, UseTally, or a tile source MvInput1…MvInput13), and trigger the overlay commands with /api/invokecommand. Target the Switcher input by targetname or its object target GUID.
• Manual control — direct UI interaction in Composer Desktop.

Tip — Stream Deck

The Companion app, paired with a virtual or physical Stream Deck, gives you a hardware-button surface for triggering Multiviewer actions over the API or via Connectors. Useful for live operators driving a show without keyboard / mouse.

Latency note

When a multiviewer source is itself a scene (rather than a raw input), expect a one-frame processing delay through that source. Composer's audio / video sync tools can compensate when this matters for downstream targets.