Switcher

Introduction

The Switcher is a virtual input that does the job of a small video-mixing console — it picks two sources (PGM "on air" and Preview "next"), switches between them on cue with either a hard cut or a timed crossfade, and offers a fade-to-black for clean show transitions. It also doubles as the host for Composer's Multiviewer, a side-by-side monitor grid showing PGM, Preview, and up to 13 input thumbnails with tally lights, VU meters, and overlay graphics.

Drop a Switcher input on a layer in any scene and target it like any other input. The same Switcher can drive both a clean PGM output (to a streaming target) and a separately-rendered multiviewer (to a confidence monitor) at the same time.

PGM / Preview switching

The classic two-bus broadcast switcher pattern:

• Pick any input or scene as the foreground (PGM) — what's currently on air.
• Pick another as the background (Preview) — what's queued up next.
• Hit Cut for an instant change, or Crossfade for a timed dissolve over a configurable duration (0–5000 ms).
• The blend slider exposes the same transition manually, so an operator can drive the dissolve by hand if needed.
• A separate Fade to black command takes the whole output to (or back from) black, useful for show-open / show-close transitions and emergency-cover situations where the PGM source can't be cut to cleanly.

Because the PGM and Preview sources can be scenes as well as raw inputs, you can pre-build complex compositions on the Preview bus (graphics + camera + lower-third + audio mix) and cut to the whole package as one move.

Multiviewer

When Create Multi View is on, the Switcher renders a separate side-by-side monitor grid in addition to its PGM output — useful as a producer / director surface for keeping every source in eye-line during a show. Briefly:

• Choose a layout — 4-input, 8-input (2 + 8 grid with prominent PGM / Preview tiles), or 13-input (adds a third row).
• Tally indicators — color each tile red for Program and green for Preview.
• VU meters — overlay per-tile audio levels; a configurable PGM VU source feeds the master meter.
• Tile aliases — the Camera1|CAM 1 syntax lets a tile show a friendly label different from the source name.
• Up to 4 overlays — bug logos, lower thirds, count-down timers — each with independent fade-in / fade-out timing.

For the full Multiviewer authoring workflow (tile assignment, overlay rules, latency note when a tile sources a scene rather than an input), see User Guide → Multiviewer.

Common use cases

• Two-source live show — a single Switcher drives a clean PGM target plus a Multiviewer monitor; the operator cuts between cameras and pre-built graphics scenes.
• Studio in a box — pair the Switcher's PGM bus with an SRT Target or RTMP Target for a contribution feed; the Multiviewer goes to a confidence monitor.
• Show-open / show-close — fade to black covers the seam between the start of a feed and the first cued shot, and the seam at end of show.
• Multi-camera production with a director surface — the Multiviewer tile labels and tally indicators give a non-Composer-trained director a familiar visual layout.
• Remote producer review — render the Multiviewer to a separate streaming target so a producer at a distant location sees every source the local operator does.

Driving the Switcher from outside

Every command (Cut, Crossfade, Fade to black, Show / Hide / Fade for each overlay) is invokable from:

• The property panel.
• The HTTP API — /api/invokecommand?targetname=Switcher&command=CutCommand etc.
• A Connector — bundle a Cut + an audio-bus change + a graphics-trigger into a single named endpoint.
• The Script Engine via ExecuteCommand / ExecuteCommandById.
• The Companion app + Stream Deck — see User Guide → Multiviewer for the operator-surface workflow.

Switcher - Settings

Layers

Layers — pick the foreground (PGM) and background (Preview) sources and switch between them.

Fade to black (FTB)

Fade to black (FTB) — fade the output to or from black.

MultiViewer inputs (optional)

MultiViewer inputs — produce a separate multiviewer image with PGM, Preview, and up to 13 thumbnails.

MultiViewer overlays (optional)

MultiViewer overlays — up to four overlay layers composited on top of the main output.

Overlay - Actions

Overlay actions — fade in, fade out, or toggle each overlay.

Inherits from: AbstractInput, AbstractAudioProcessing, AbstractAudioMetering.

See also: Switcher in Script Engine Objects.

Shared input properties

Every input — regardless of source type — exposes the following property groups. They are surfaced in the property panel only when Show advanced options is enabled on the input.

Icon

• Icon text — short text shown on the input's icon in the Inputs list. Useful as a quick visual label (channel number, mic name, camera position) to tell otherwise-similar inputs apart at a glance. Empty by default; has no effect on rendering or routing.

Audio mixer

• Hide in audio mixer — when on, hides the input from the audio mixer view without disabling its audio. Useful for de-cluttering the mixer while keeping the audio routed (e.g. fixed background music, ambient beds, pre-aligned playout). [default=false]

Render Options

• Invisible (Do not render in scene) — when on, the input is skipped during rendering and produces no picture on any layer or scene. Audio routing is unaffected. Toggle from a script for cued-in / cued-out behaviour during a show. [default=false]
• Do not render input — disables the input's internal render entirely (no decode or capture work is done). Stronger than Invisible: that one renders but doesn't display; this one stops the input from doing any work at all. Useful for reducing CPU / network load on heavy sources (e.g. high-bitrate RTMP / SRT streams, large media files) when the input is temporarily not needed. Audio meters are cleared while disabled. [default=false]
• Do not render input controller — chooses what drives the Do not render input flag. Let Composer decide (the default) hands control to the project-level Render Tuning optimiser, which automatically pauses inputs that aren't used by any active scene. Manual Configuration ignores Render Tuning and lets the Do not render input toggle control the flag directly — use this to keep a network source warm even when it's currently off-air, or to take a heavy input down by hand regardless of scene activity. [default=Let Composer decide]

Optional TAGS

• TAGS — one or more free-form tag words used to classify this input (typically space- or comma-separated). Picked up by Composer's Smart Search to filter or find inputs by category — e.g. camera, music, interview, sponsor. Has no effect on rendering.

Audio configuration and processing options

For inputs capable of processing audio, additional audio configuration and processing options are available through the audio mixer and the Channel Strip Inspector.

• Audio mixer — monitor levels, adjust gain and pan, mute / solo inputs, and configure auxiliary sends to Audio Channel Strip submix buses, all from a centralised mixer-style interface.
• Channel Strip Inspector — advanced per-strip audio processing for the selected input:
  • Input trim, stereo remapping, and audio delay
  • Channel mapping (8-channel mode unlocks the full MAPPING tab)
  • Gate
  • Low-cut filter
  • Equaliser (5-band parametric)
  • Compressor
  • Sidechain ducking (a second compressor whose gain reduction is driven by another input's level — e.g. dipping music under a voice-over)
  • Limiter

For the full audio signal flow, see Audio processing workflow.