Using the Video Switcher Compound

Introduction

Video_Switcher is a software-native production video switcher compound for live broadcasting and streaming workflows. It runs entirely inside Aximmetry and brings together the operations of a hardware mixer: routing a selected input to the program output, cueing the next input on preview, performing cuts and named transitions between them, layering up to three picture-in-picture windows, mixing program audio from the on-air video plus four standalone audio inputs, generating a multiview monitor, and driving the built-in streamer and recorder.

Each of the twelve inputs can be sourced from a live capture device, an external/test feed, or a video file. The first four inputs additionally come with their own CROP, KEYER (chroma/luma/external/clean-plate), and ADJUSTER stages, so they can be conditioned in place before going on air. Four extra standalone audio inputs let you bring in microphones, music beds, or remote audio that is not bound to any video.

Setup

Adding the Compound

Add Video_Switcher from [Common_Studio]:Compounds\Switcher onto the root level of your scene.

Typical Wiring

Each of the twelve input lines can be sourced from a live capture device, a video file, or the matching Ext N input pin — so once the compound is added, no extra wiring is strictly required. Connect only what you actually need on top.

• In Startup Configuration the recommended output setup is the following:
  
  • Output #1 goes to the secondary monitor of your PC for previewing.
    NOTE: This is only applicable if you have a secondary monitor; otherwise, you can skip Output #1 and view the preview picture in a Preview panel of the Composer.
  • Output #2 is the final program output. It can be either a direct streaming output for live productions or an SDI output that feeds your studio system. For details on setting up streaming, see this documentation.
  • If you only plan to record the production locally, you can omit setting up Output #2; Video_Switcher handles the recording internally.
• Output side — wire out Multi, On Air, On Air Audio, and Preview (optional) to the right side of your compound, in this order:
  
  With the recommended output setup, this will result in:
  • Multi goes to the preview monitor.
  • On Air and On Air Audio together go to the program output (streaming or SDI).
  • Preview can be viewed in a Preview panel of the Composer on Channel 3.
    NOTE: This is optional, since the Preview is also visible in the Multi-output.
• External video/audio per input line (optional) — connect a non-device source (rendered video and audio, test pattern, etc.) into the matching Ext N / Audio N input pins, then switch that input to EXT on the INPUTS board.
• Standalone audio inputs — feed microphones, music beds, or remote audio into your PC's sound card, and select the corresponding device on the AUDIO N panels of the INPUTS board.
• Custom transitions (optional) — wire Trans Video 1, Trans Video 2, and Trans Fade to your transition renderer compound and return its output to Trans A Out, Trans B Out, or Trans C Out (see Custom Transitions).
• Multiview status overlay (optional) — add [Common_Studio]:Compounds\Switcher\Video_Switcher_Status.xcomp next to the switcher and wire it into one of the Ext N pins, typically Ext 8 (see Multiview Status Summary).

Typical Settings

Most projects only need to touch a handful of properties before going on air:

• INPUTS board, for each input you intend to use — on the INPUT panel, pick the Live Device (or Video File), set the Label that will appear on the multiview tile, and choose LIVE, EXT, or video thumbnail as the active source. Inputs 1–4 additionally expose CROP, KEYER, and ADJUSTER stages — leave them off unless you actually need them.
• SWITCHER board, ON AIR panel — set the On Air Label, Preview Label, and Multi Label so the multiview reads cleanly, and use Size, Align, and Offset to position the program composite where your output renderer expects it.
• SWITCHER board, SWITCH TO PREVIEW panel — set the default Transition Time, and if you wired custom transitions, pick which one is bound to Trans A, B, or C.
• SWITCHER board, RECORDER panel — set the Output Folder, Output File, the encoder, and choose which streams to record before arming.
• Streaming is configured at the project level — the switcher only toggles it on or off.

For a step-by-step pre-show and on-show routine, see Typical Operator Workflow at the end of this document.

Compound Output Pins

Pins exposed on the right side of the Video_Switcher compound — these are the signals the switcher delivers to the rest of your project (output renderers, broadcast outs, additional processing, etc.):

• On Air: Final program video: the selected on-air input combined with the active picture-in-picture overlays and the active transition.
• On Air Audio: Mixed program audio bus produced from the on-air video player's audio and the four standalone audio inputs.
• Preview: Preview video showing the input currently cued for the next take.
• Multi: Multiview output: all input thumbnails plus dedicated program and preview tiles, with status decorations (recording, on-air, etc.).
• Trans Video 1: Outgoing program-side video feed sent to an external transition renderer.
• Trans Video 2: Incoming preview-side video feed sent to an external transition renderer.
• Trans Fade: Current fade ratio of the active transition between the outgoing and incoming sides (use this to drive the timing of any externally rendered transition).

The external transition path (Trans Video 1, Trans Video 2, Trans Fade, and the matching Trans A/B/C Out input pins below) lets you implement custom-rendered transitions (DVE, stingers, wipe shaders, etc.) outside the switcher and route them back in. See Custom Transitions for the full wiring.

Compound Input Pins

Pins exposed on the left side of the Video_Switcher compound — these are the signals the switcher accepts from the rest of your project, beyond the live device feeds that each input picks up by itself:

• Ext 1 … Ext 12: Optional external/test video signals routed into the matching input line when its source is switched to EXT.
• Audio 1 … Audio 12: External/test audio signals routed alongside each input line when its source is switched to EXT.
• Ext Audio 1 … Ext Audio 4: External audio signals routed into the four standalone audio inputs when their source is switched to EXT.
• Trans A Out, Trans B Out, Trans C Out: Return paths: the externally rendered Trans A / Trans B / Trans C transition video is fed back into the switcher's transition stage here.

Control Boards

Video_Switcher provides two control boards:

• SWITCHER — the operator board for live show running: program/preview selection, PIPs (Picture-in-Pictures), transitions, audio mix, recording, and streaming.
• INPUTS — the engineer / pre-show board for configuring each video and audio input (source, color processing, cropping, keying).

SWITCHER Control Board

ON AIR Panel

Selects the input that is sent to the program output and configures program-output placement and on-screen status labels.

Buttons — 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12: send the corresponding input to the program output.

Properties

• Horiz Align, Vert Align: Horizontal and vertical alignment of the program composite within the output frame.
• Horiz Offset, Vert Offset: Offsets of the program composite relative to its alignment anchor.
• Size: Uniform scale factor applied to the program composite.
• On Air Label: Label drawn on the on-air tile of the multiview.
• Preview Label: Label drawn on the preview tile of the multiview.
• Multi Label: Label drawn on the multiview header area.

PREVIEW Panel

Selects which input is shown in the preview slot for cueing the next take.

Buttons — 1 … 12: cue the corresponding input to the preview slot. OFF: clears the preview slot so no input is cued.

By default, the multiview shows only inputs 1–8 (together with the program and preview tiles). To see all twelve inputs at once on the multiview, switch PREVIEW to OFF: the multiview then drops the dedicated preview tile and lays out all 12 inputs instead.

NOTE: In this mode, neither Take nor any Trans A / B / C transition can be triggered — without a PREVIEW selection, there is no incoming input to swap to. The only way to change the program output in 12-input mode is directly on the ON AIR panel.

SWITCH TO PREVIEW Panel

This panel triggers the program ↔ preview swap. Five swap modes are offered:

• Take: Performs the swap immediately as a hard cut.
• Trans A: Performs the swap as an automatic transition driven by the Trans A renderer over the configured Transition Time.
• Trans B: Same as Trans A, using the Trans B renderer.
• Trans C: Same as Trans A, using the Trans C renderer.
• FTB: Fades the program output to black over the configured Transition Time.

After a Take or any Trans A / B / C transition completes, the selected ON AIR and PREVIEW inputs are exchanged: the previously cued PREVIEW input becomes the new program, and the input that was on air drops back into the PREVIEW slot, ready to be cued again.

Properties

• Transition Time — duration in seconds used by the automatic transitions on this panel.
• Manual Trans Type — selects which named transition (Trans A, Trans B, or Trans C) is driven by the manual slider.
• Manual Transition — manual transition position: 0 = fully on the current program, 1 = fully swapped to preview. Drives the selected named transition with operator-controlled timing. Typically, this property is assigned to an external controller, usually a T-bar, so the operator can ride the transition by hand.

OVERLAY / PIP Panels

There are three identical picture-in-picture overlay layers, stacked PIP 1 (bottom) → PIP 2 → PIP 3 (top) on top of the program composite.

For each PIP layer:

Buttons — 1 … 12: show the corresponding input in this picture-in-picture window. OFF: hides this picture-in-picture window.

Properties

• Horiz Align, Vert Align: Alignment of the PIP window inside the program frame.
• Horiz Offset, Vert Offset: Offsets of the PIP window relative to its alignment anchor.
• Size: Uniform scale factor of the PIP window.
• Show Border: Switches the outlined frame around the PIP window on or off.
• Border Color: Color of the optional outlined frame.
• Border Width: Width of the optional outlined frame.

STREAMING Panel

Button — On: switches live streaming of the program output on or off.

VIDEO Transport Panel

Global transport that controls every input video player at once.

• Stop: Stops every input video player.
• Pause: Pauses every input video player.
• Play: Plays every input video player.
• Restart: Restarts every input video player from the beginning.

RECORDER Panel

Configures and runs the video recorders for the program output, the first four inputs (ISO recordings), and the multiview.

Buttons

• On Air: Switches recording of the program output on or off.
• 1, 2, 3, 4: Switches isolated recording of input 1 / 2 / 3 / 4 on or off.
• Multi: Switches recording of the multiview output on or off.
• Record: Starts or stops all enabled recordings together.

Properties

• Output Folder: Destination folder for the recorded files.
• Output File: Base file name used for the recorded files.
• Downscale: Switches scaling the recorded video down to a fixed size on or off.
• Downscale Size: Target frame size used when Downscale is on.
• Video Format: Codec/container used to encode the recorded video.
• Cine Form Quality: Quality preset used when the video format is a CineForm variant.
• Video Mbps: Target video bitrate of the encoder, in megabits per second.
• Keyframe Dist: Distance in frames between keyframes in the encoded stream.
• Audio Format: Codec used to encode the recorded audio.
• Audio Channels: Channel layout of the recorded audio.
• Audio Kbps: Target audio bitrate of the encoder, in kilobits per second.

AUDIO Panel

Mixes the program audio bus from the on-air video player's audio and the four standalone audio inputs, and provides global audio-player transport.

Source on/off buttons

• V: Switches the on-air video player's audio into the program audio mix on or off.
• 1, 2, 3, 4: Switches standalone audio input 1 / 2 / 3 / 4 into the program audio mix on or off.

Transport buttons — Stop, Pause, Play, Restart: control playback of every input video player providing audio.

Properties

• Video Level: Level of the on-air video player's audio in the program mix.
• Audio 1 Level … Audio 4 Level: Levels of standalone audio inputs 1–4 in the program mix.
• Show Indicator: Switches the on-screen audio level indicator on or off.

INPUTS Control Board

The INPUTS board gives engineering-level access to every input. Inputs 1–4 are full-featured: each one carries an INPUT panel, plus its own CROP, KEYER, and ADJUSTER. Inputs 5–12 are simpler: only the INPUT panel (source / playback) is exposed. There are also four AUDIO panels for the standalone audio inputs.

Video INPUT Panel (Per Input)

Each input panel configures the input line as either a live device feed or a video file.

Source buttons

• LIVE: Uses the live device feed as the input.
• EXT: Uses the matching external Ext N feed as the input.
• Play: Triggers playback of the configured video file.

Properties

• Live Device: Live device name supplying the LIVE feed.
• Live Mode: Video mode requested from the live device.
• Video File: Path of the video file played on this input.
• Label: Custom label shown on the multiview tile of this input.
• Continuous Playing: Keeps the video file playing even while the input is not on air.
• Looping: Loops playback of the video file.
• Position: Playback position in seconds within the video file.
• Audio Level: Output level of the audio carried by this input.

CROP Panel (Inputs 1–4)

Crops and reorients an input before keying.

• Active: When on, cropping is applied; when off, the input passes through uncropped.
• Left, Right, Top, Bottom: Amount cropped from each edge of the input.
• Portrait: When on, treats the input as a portrait-oriented source (rotates the cropped frame 90 degrees).
• CCW: When the source is a portrait, it rotates counterclockwise instead of clockwise.

KEYER Panel (Inputs 1–4)

Chroma keys the input. The KEYER is itself a multi-stage chooser: switch the keyer on or off, optionally route its monitor view to the multiview for matte inspection, freeze its input frame while tuning the key, and pick which keying algorithm is in use.

The keyers are intended primarily for picture-in-picture use, where one of the keyed inputs is placed on top of the program via an OVERLAY / PIP layer — for example, a vlogger or commentator shot against a green/blue screen, keyed out and dropped into the corner over the main content.

Buttons

• On: When on, the keyer is processing the input; when off, the line passes through unkeyed.
• Show: Routes the keyer's monitor view of this input to the multiview for matte inspection.

Top-level properties

• Freeze Input: Freezes the keyer's input frame while the operator tunes the key.
• KEYER TYPE: Selects which keyer algorithm is used. ADVANCED B is the recommended default; the controls and behavior of each algorithm are the same as Aximmetry's general-purpose keyers — see the Aximmetry keying documentation for a full reference.

ADJUSTER Panel (Inputs 1–4)

Color, level, and sharpening correction are applied to the input.

• Active: When on, the adjuster modifies the input; when off, it passes through unchanged.
• Brightness: Brightness offset.
• Contrast: Contrast multiplier.
• Saturation: Color saturation.
• Hue: Hue rotation.
• Red, Green, Blue: Per-channel gain.
• In Black, In White: Input black and white levels of the levels curve.
• Gamma: Gamma of the levels curve.
• Out Black, Out White: Output black and white levels of the levels curve.
• Luminosity: Luminosity weight that scales the keyed result of this input in the final composite.
• Ambient: Ambient-light contribution of this input in the final composite.
• Diffuse: Diffuse-light contribution of this input in the final composite.
• Sharpen: Extra sharpening applied to the input.

Standalone AUDIO Panel (Audio Inputs 1–4)

Configures a standalone audio input as either a live device, an external feed, or an audio file.

Source buttons

• LIVE: Uses the live audio device as the audio input.
• EXT: Uses the matching external Ext Audio N feed.
• FILE: Uses the configured audio file.
• Play: Triggers playback of the configured audio file.

Properties

• Live Device: Live device name supplying the LIVE feed of this audio input.
• Audio File: Path of the audio file played on this audio input.
• Continuous Playing: Keeps the audio file playing even while this input is not in the program mix.
• Looping: Loops playback of the audio file.
• Position: Playback position in seconds within the audio file.

Custom Transitions

The named transitions Trans A, Trans B, and Trans C offered by the SWITCH TO PREVIEW panel are not rendered by the switcher itself — Video_Switcher only exposes the three feeds needed to run an external transition renderer and re-imports its result. This lets you build any transition you like (DVE wipes, stinger overlays, displacement/blur effects, custom shaders) as a separate compound and plug it into one of the three slots.

The wiring is the same for all three slots — only the slot-specific return pin changes:

From the switcher	Connect to the transition compound's	Purpose
Trans Video 1 (output)	Video 1 (input)	Outgoing program-side video.
Trans Video 2 (output)	Video 2 (input)	Incoming preview-side video.
Trans Fade (output)	Fade (input)	Fade ratio 0 → 1 produced by the switcher, drives the transition timeline.
Out of the transition compound	Trans A Out / Trans B Out / Trans C Out (input)	Returns the rendered transition video into the chosen slot.

The slot you wire the Out into determines which button on the SWITCH TO PREVIEW panel runs your custom transition: route the result back to Trans A Out to take over the Trans A button, Trans B Out for Trans B, Trans C Out for Trans C. The slots are fully independent, so you can assign up to three different custom transitions at once. If a slot's Trans … Out input is left unconnected, the corresponding button runs the switcher's built-in simple cross-fade.

Stock transitions — a library of ready-made transition compounds is shipped in [Common]:Compounds\Transitions. Drop any of them onto the flow next to Video_Switcher and wire it as described above.

Multiview Status Summary

   

If you want a status summary (recording state, on-air/preview labels, transition info, etc.) to appear inside one of the multiview tiles, load [Common_Studio]:Compounds\Switcher\Video_Switcher_Status.xcomp and wire its output into one of the Ext N input pins of Video_Switcher. Then switch the matching input line to EXT on the INPUTS board so the multiview tile of that line picks up the status overlay.

Typically, you wire it into Ext 8, which puts the status summary in the bottom-right corner of the multiview.

External Controllers

A typical setup is to assign the most important buttons (on the ON AIR, PREVIEW, and SWITCH TO PREVIEW panels) to a physical controller such as Stream Deck, Loupedeck, or X-Keys.

One controller that can cover almost all functions of Video_Switcher is the X-keys XKE-124 T-Bar pre-assembled with video switcher key set. For that specific controller, a ready-made assignment preset is provided at [Common_Studio]:Compounds\Switcher\Video_Switcher_XKeys.xctrs.

To use it, after adding the Video_Switcher compound to your scene, go to File / Properties / Game Assignments, click Load..., select the file above, then click OK — and you are done.

NOTE: these assignments only work if the compound is named exactly Video_Switcher and resides at the root level of the scene.

Using a 3D Virtual Scene as an Input

A common case is to route a rendered virtual scene into one of the Ext N inputs:

1. Connect the Out pin of the Cam compound to one of the Ext N input pins of Video_Switcher:
   • 
2. On the corresponding INPUT panel, set the source to EXT so the switcher picks up the virtual-scene feed:
   • 

One thing is missing here, however: if you need to modify the setup of the virtual scene itself, you'll need Cam's Preview output as a full-screen view. You can follow two approaches:

• Use the same secondary monitor that displays Multi: temporarily connect Cam's Preview to the Multi output. Now you can view/edit the virtual scene setup on the secondary monitor. Upon finishing the setup, you can restore the original wiring to see Multi again.
• 
• Or: wire out Cam's Preview as a separate output channel and view/edit it in one of the Composer's Preview panels.
• 

Typical Operator Workflow

A typical live-show session with Video_Switcher looks like this:

1. Engineering pass (INPUTS board). For each input you intend to use:
   • On the input's INPUT panel, point it at the right Live Device / Video File and choose LIVE, EXT, or Play as the active source. Set the Label that will appear on the multiview tile.
   • On inputs 1–4, optionally enable CROP, configure KEYER TYPE and tune the matte, and tweak the ADJUSTER for color matching.
   • For the four standalone audio inputs, set up sources and files on the AUDIO N panels.
   • Optionally, set up a physical controller to drive the most important buttons (see External Controllers above).
2. Multiview & program setup (ON AIR panel). Set On Air Label, Preview Label, and Multi Label so the multiview reads cleanly on air. Use Size, Horiz/Vert Align, and Horiz/Vert Offset to place the program composite where the broadcast graphics expect it.
3. Show start. Click the input number on ON AIR to take it directly to the program; click the next intended input on PREVIEW to cue it.
4. Switching. Use SWITCH TO PREVIEW:
   • Take for hard cuts.
   • Trans A / B / C for automatic named transitions (set Transition Time first; see Custom Transitions for how each slot is wired to an external transition renderer).
   • FTB to fade to black.
   • Manual Transition + Manual Trans Type to ride a transition by hand.
5. Overlays. Bring in OVERLAY / PIP 1, 2, 3 to add picture-in-picture windows on top of the program. OFF hides a PIP. Tune Size, Align, Offset, and optionally Show Border / Border Color / Border Width.
6. Audio mixing. On the AUDIO panel, toggle V, 1, 2, 3, 4 to choose which sources feed the program bus, then ride Video Level and Audio 1 Level … Audio 4 Level.
7. Recording. On the RECORDER panel, pick Output Folder / Output File and the encoder settings, choose which streams to record (On Air, ISO inputs 1 … 4, Multi), then arm them and hit Record.
8. Streaming. Toggle STREAMING / On to go live (the streaming endpoint must already be configured at the project level).
9. Playback transport. The VIDEO panel offers global Stop / Pause / Play / Restart across every input video player; the AUDIO panel offers the same for audio playback.