Switching & Signal Routing — Advanced
Introduction
A small show runs on one row of buttons: cameras on preview, a take, a lower third. A large show runs on several switchers inside one panel, a router feeding them hundreds of sources, and a stack of looks built and stored before the doors opened. The technical director, the TD, presses the buttons, but the show was won or lost in the preparation.
This book picks up where Video Switching Fundamentals stops. It covers switchers with several mix/effects banks and how they feed each other; boxes, picture-in-picture and DVE; macros and memories; matrix routers and how large systems are named, protected and tied together; and how a TD prepares so that the live show is muscle memory.
It draws on the operating manuals of Blackmagic Design's ATEM switchers and Videohub routers, Ross Video's Carbonite switchers and NK routers, Grass Valley's router configuration notes, Ron Whittaker's television production text, and an NBC technical director's account of cutting live sport.
How to Use This Book
Read Video Switching Fundamentals first. The examples here use real switchers and routers, because the ideas are the same across makers and the names are not. Learn the ideas, then learn the names your own equipment uses.
Advanced Switching & Routing
Complex shows and large systems.
Beyond basic switching
Video Switching Fundamentals covered the basics — selecting and transitioning between sources on a switcher. Advanced switching handles complex, demanding productions: big shows with many sources, layered effects and composites (multiple images combined), macros and memories (pre-built complex looks recalled instantly), and large multi-ME switchers (with multiple mix/effects banks for complex layering). And signal routing scales up to matrix routers and large routing systems that route many signals around big productions. The advanced level is about complexity, scale, and flawless execution. Advanced work means complex shows and large systems.
This matters because major productions (big broadcasts, large live shows, complex events) require advanced switching and routing — many sources, complex looks, and large signal systems, all switched and routed flawlessly live. The advanced operator handles this complexity under pressure. Advanced switching and routing power major productions.
Whittaker notes that the programme bus handles more than 90 percent of all switching. The advanced switcher exists for the other 10 percent, the composites and effects that would be impossible to build live, and for shows that need several different outputs at once.
Its building block is the mix/effects bank, the M/E: a complete switcher row with its own programme and preview buses, its own transition and its own keyers. Blackmagic's ATEM Constellation range runs from 1 to 4 M/Es, each with four upstream keyers, plus downstream keyers on the final output. Ross's Carbonite gives each M/E four keyers and adds a smaller MiniME for simple cuts and dissolves.
Switching and routing together
At the advanced level, switching and routing work together in large systems. Routing (via matrix routers) gets all the many signals to where they're needed (including to the switcher's inputs); switching (on powerful switchers) selects, layers, and composes them into the programme output. In a big production, the routing system distributes the many sources, and the switcher (or switchers) builds the show from them. Routing distributes the signals; switching builds the show.
This systems view matters at scale: big productions have complex signal infrastructures (many sources, routers, switchers, processing, destinations), and the advanced operator understands and works within this. The advanced operator works within large switching-and-routing systems.
A switcher chooses among the sources it can see. A router decides which sources it can see in the first place, and where everything else goes: recorders, monitors, IMAG, the stream. Most large systems put a router in front of the switcher, so any of hundreds of sources can be brought to a switcher input when needed.
Switchers have small routers built in too. Blackmagic's manual describes the ATEM's outputs as working much like router outputs: each can carry any input, the programme, the preview, a clean feed without graphics, or any M/E's output, and every change is a clean switch.
Advanced Switcher Features
Keys, DVE, composites, macros, multi-ME.
Layering and effects
Advanced switchers do more than cut between sources — they layer and combine them. Keying combines images (e.g., a chroma key/green screen, or a luma/linear key for graphics over video — putting a logo, lower-third, or keyed element over the picture). DVE (Digital Video Effects) manipulates images (resizing, moving, picture-in-picture, transitions, multi-box layouts). Composites combine multiple layers into one complex picture. These layering and effects capabilities let the operator build rich, complex looks (a presenter keyed over a background with graphics and a PIP). Understanding layering and effects is central to advanced switching. The switcher composes layered, complex images.
These capabilities are what make advanced switching powerful: instead of just one full-screen source at a time, the operator composes sophisticated images from multiple layers. Mastering keys, DVE, and composites lets the operator create the complex looks modern productions need. The advanced operator builds complex composited looks.
Advanced work stacks keys. A look might be a camera background, a picture-in-picture of a slide from one keyer, a logo from another, and a name strap from a downstream keyer. Build it in layers, check each layer on preview, and remember which keyer holds what.
The DVE, digital video effects, moves and resizes a picture. ATEM keyers can each be a DVE key, but Blackmagic notes that DVE channels are shared between DVE keys and DVE transitions: if a key is using the DVE, a DVE transition is unavailable until it is freed. Ross's Carbonite DVE is likewise a limited number of channels. Count the DVEs a look needs before promising it.
For several boxes at once, such as a panel of remote guests, ATEM switchers have SuperSource: a single source built from several boxes, each with its own position, size and crop, over a background or under foreground art, chosen from preset layouts. It appears on the switcher as one more input.
Macros, memories, and multi-ME
To manage complexity, advanced switchers offer macros, memories, and multiple ME banks. Memories/snapshots store complex looks (a whole configured composite) to recall instantly. Macros record sequences of actions to execute with one button (automating complex moves). Multiple ME (mix/effects) banks let the operator build and layer multiple effects stages (one ME builds a composite that feeds another). These tools let the operator handle very complex shows reliably — pre-building looks and sequences and recalling them precisely live. Understanding macros, memories, and multi-ME is central to advanced switching. These tools manage complexity and enable precision.
On a complex show, the operator pre-builds looks (memories) and sequences (macros) in preparation, then executes them flawlessly live (recalling the right look or running the right macro on cue), using the multi-ME capability to layer it all. This preparation-plus-execution is how advanced shows are switched reliably. The advanced operator uses memories, macros, and multi-ME to handle complex shows.
An M/E's output can be fed into another M/E as a source, called re-entry. Ross's manual describes the method: build a composite on one M/E, then select that M/E on the background bus of another, which adds its own keys on top. Ross notes the limits: an M/E cannot be re-entered into itself, and on Carbonite M/E 2 cannot be re-entered into M/E 1. Blackmagic's equivalent is an M/E 2 button that brings a look built on M/E 2 to air or preview on M/E 1.
Several M/Es also make several programmes. Blackmagic's bus mapping lets a follower M/E copy every cut and transition of the main one while substituting different sources, giving up to four distinct programmes, one for a stream and one for the venue screen, for example.
Memories store a whole look. Ross's Carbonite stores up to 100 memories per M/E, each a snapshot of keyer settings, transition rates, patterns and sources, and recalls them without touching what is on air: the recalled look waits on preview. Macros record a sequence of actions. ATEM switchers hold 100 macros, which record only the settings that change, so a value already set must be changed and set back while recording. Blackmagic's advice is to build big macros from small ones, so a mistake means re-recording one small piece.
Save the switcher's state. ATEM switchers save to a file with the media pool, and Blackmagic recommends a copy on an external drive. Ross's memories can be saved to USB for every operator and every show.
Signal Routing
Matrix routers and large systems.
Matrix routing
Signal routing at the advanced level centres on the matrix router (or router) — a device that can connect any of many input signals to any of many outputs, on command. A matrix router lets a production route any source to any destination (any camera, playback, or feed to any switcher input, monitor, recorder, or output), flexibly and instantly. In large productions, the router is the central signal hub, distributing all the signals where they're needed. Understanding matrix routing is central to advanced signal routing. The router connects any source to any destination in the system.
This is essential in big systems: with many sources and destinations, the router provides flexible, centralised control over what goes where (rather than fixed wiring). The operator/engineer configures and controls the routing to get the right signals to the right places. The matrix router is the flexible signal hub of a large production.
A matrix router connects any input to any output. Each connection is a crosspoint. On a router panel, the order is destination first, then source. Blackmagic's Videohub manual describes it: press the output, then the input, then take. The take button is a safety step, confirming the route before it switches; smaller Videohubs switch as soon as the source is pressed, and take can be turned off per output.
Router panels come in two layouts. A single-destination panel has a button for every source and controls one output, such as a monitor. An XY panel has destination buttons as well, so one panel can route many outputs; Blackmagic's manual is firm that on an XY panel you always choose the destination first.
Routers can switch several routes at once. Videohub panels store routing macros of up to 16 crosspoints switched together, and its control protocol can queue several routes as a salvo to execute at once. Ross's NK panels call partial routes breakaways, and allow up to eight.
Managing routing in large systems
In large productions, signal routing must be managed — organised, controlled, and reliable. This means configuring the router (setting up sources and destinations, naming/labelling them clearly), controlling the routing live (changing what's routed where as the production needs, via control panels or software), and keeping it organised and reliable (so the right signals are always where they should be, and changes are clean). Managing routing well keeps a complex production's signals under control; poorly managed routing causes confusion and wrong feeds. Managing signal routing is central to advanced work. The operator/engineer keeps the routing organised, controlled, and reliable.
This is part of the technical operation/engineering of large productions: the routing system must be set up and run so all the signals flow correctly throughout the show. A well-managed routing system is invisible and reliable; a poorly managed one is a source of errors. The professional manages the routing so the right signals always reach the right places.
Names make a large router usable. Every input and output should have a clear, consistent label, which then appears on every panel and multiviewer. Videohub panels can filter by label text, showing every output containing DECK or every input containing CAM, but only if the labels were set up first. ATEM switchers allow a long name of 20 characters and a 4-character short name for each source.
Protect what matters. A locked destination on a Videohub refuses any new route until it is unlocked, which keeps the transmission feed or a recorder from being changed by mistake. In Blackmagic's software, a lock set from one computer blocks everyone else, and shows them a different padlock so they know who holds it.
Large facilities join routers together with tie lines: an output of one router wired to an input of another, so a source in one area can reach a destination in another. Grass Valley's configuration notes stress that all the routers must share the same virtual level structure, since tie lines bind them together, and that a pair of ports is given up for each tie line.
Practice it
A conference has 60 sources on a router feeding a 2 M/E switcher, a recorder and a stream.
Flawless Live Execution
Operate complex shows perfectly under pressure.
Preparation and execution
Advanced switching demands flawless live execution, which comes from preparation plus skilled execution. Preparation — building the show in advance (memories, macros, the routing, the looks), knowing the show and the plan, and being ready for every cue — sets up success. Execution — operating the switcher (and routing) live, recalling looks, running macros, cutting and composing, all flawlessly on cue through a complex show — delivers it. The advanced operator prepares thoroughly and executes precisely, so a complex show runs perfectly. Preparation plus execution is how advanced shows are switched flawlessly. Prepare thoroughly, then execute precisely.
Complex shows can't be improvised — they require building the looks and sequences in advance and then executing them accurately live. The advanced operator's preparation makes flawless execution possible, and their skill makes it happen. The advanced operator prepares and then executes complex shows flawlessly.
The NBC Sunday Night Football technical director John Howard, writing for Grass Valley, describes the TD's part as running through the whole planning process, and the live work as mostly muscle memory, with no searching and no hesitation, which only works if the show was built properly beforehand. He adds a warning: it is easy to overbuild, and complexity comes back in the moment. If something does not need to be complicated, it should not be.
Prepare in this order: name every source, build and store every look as a memory or macro, rehearse every transition with the director, save the switcher's state, and write the show's sources, looks and their buttons into the script. Whittaker adds the backup plan: plan B, and perhaps plan C, and a working spare intercom line.
Under pressure
Advanced switching happens live, under pressure — complex shows, high stakes, no second chances, fast-moving, with the programme output going out live. The advanced operator executes flawlessly under this pressure: staying calm and precise, hitting every cue, handling the complexity, and recovering instantly from anything that goes wrong, all while the show is live. This composure and precision under pressure is what separates an advanced operator — the ability to execute complex switching perfectly when it counts. Flawless execution under pressure is the mark of advanced switching. The advanced operator stays precise and calm under live pressure.
When something unexpected happens (a source fails, a cue changes, an error), the advanced operator handles it instantly and keeps the show going flawlessly. Their preparation, skill, and composure deliver a perfect show under pressure. Combining advanced features, routing, preparation, execution, and composure under pressure is advanced switching. The advanced operator executes complex live shows flawlessly. This is the craft at full demand. The advanced operator delivers perfect switching under pressure.
Keep your eyes on preview. Whittaker's reason for the preview bus is to set up and check before switching, or end up with unpleasant surprises. A Carbonite memory recall waits on preview rather than going straight to air, for the same reason.
When the wrong thing goes to air, fix it with one action, not three. Cut back to the last good source, then find out what went wrong. Tell the director plainly. And listen for the standby, so the next take is already waiting on preview when the call comes.
Practice it
A look with a picture-in-picture, a logo and a name strap needs to go on air six times in a keynote.
Mastering Advanced Switching
A senior video-operation skill and engineering path.
The advanced operator
Pulling it together, advanced switching and routing is operating complex live productions — using advanced switcher features (keys, DVE, composites), macros and memories, multi-ME switchers, and matrix routing, with flawless execution under pressure. The advanced operator combines deep switcher and routing knowledge, preparation, precise live execution, and composure. This makes them capable of switching major, complex productions, and it is a senior, valued video-operation skill and a path towards video engineering. Advanced switching mastered is executing complex live productions flawlessly.
Advanced switching and routing are needed for the biggest productions (major broadcasts, large live shows, complex events), and skilled advanced operators are valued and well-compensated. It also leads towards broader technical roles (video engineering, technical direction). Understanding advanced switching and routing is a senior video capability. This book has built that understanding. The advanced operator powers major live productions.
Developing advanced switching
Developing advanced switching means mastering the fundamentals first (Video Switching, Video Intermediate), getting hands-on with advanced switchers and routers (learning the features, macros, memories, multi-ME, routing), operating increasingly complex shows, and building the preparation and composure that flawless live execution requires. It connects to Video Engineering and broadcast/live production. The best advanced operators have total command of their switcher and routing, thorough preparation, flawless live execution, and unshakeable composure, built over many complex shows. Deliberately developing these is the path forward.
From here, growing means switching bigger and more complex productions, building towards technical direction and video engineering, and reaching the top of video operation. It is a senior, valued, in-demand video skill at the heart of major productions. The skills this book brings together — advanced features, routing, preparation, execution, composure — are the foundation; mastery comes from operating many complex shows. Keep switching more complex shows, keep building your command and composure, and you grow into an advanced switching and routing operator.
Glossary
| Composite | An image combining multiple layers |
| DVE | Digital Video Effects (resize, move, PIP) |
| Keying | Combining images (chroma/luma key) |
| Macro | A recorded sequence of actions on one button |
| Matrix router | Connects any input to any output |
| ME | Mix/Effects bank on a switcher |
| Memory/snapshot | A stored look recalled instantly |
| PIP | Picture-in-picture |
| Re-entry | Feeding one M/E's output into another as a source |
| Crosspoint | One connection from a router input to an output |
| Take | Confirming a route or transition before it happens |
| XY panel | A router panel that chooses both destination and source |
| Salvo | Several routes switched together |
| Tie line | A link between two routers |
| Lock | Protecting a router destination from changes |
| SuperSource | An ATEM source built from several boxes |
| Technical director | The person operating the switcher |
Where to Go Next
Video Engineering covers the system the switcher and router sit in, Camera Directing the calls the TD answers, and Video Intermediate the signals they carry.
The first ninety days
Three things. Learn every memory and macro function of the switcher you use most. Label one router completely. And rehearse one show's looks until you can recall them without looking down.
What the gear actually looks like
Every device named in this book, in one place. Recognition is the whole point of Chapter 4 — use this page to attach a picture to each name before you meet it on a dock at six in the morning.
Find the destination.
Work along the path between them.