How to use live sports graphics with a hardware switcher

Plenty of school and league productions run on a hardware video switcher instead of OBS: several cameras go into a box with buttons, and the director cuts between them. The question is how to get live scoreboard graphics on top of those cameras. The answer most crews use is a computer showing the graphics on a green background, fed into the switcher like another camera, then keyed out. This guide covers that signal chain from end to end.

How the green-screen method works

A switcher can't load a web page, but it can take any HDMI signal. So you turn the graphics into a video signal:

1. A computer opens the scoreboard output page, which shows the graphics on a solid green background.
2. The computer's HDMI output goes into one of the switcher's inputs.
3. The switcher's keyer treats that input as a graphics layer and removes the green, leaving only the scorebug and other graphics over whatever camera is on air.

ScoreCastr has a green-screen version of the output built for exactly this. On the match, use the HDMI Output button to open it. The scorekeeper runs the dashboard on a separate phone, tablet or laptop, and the graphics computer just displays the output. ScoreCastr doesn't connect to the switcher directly; the HDMI cable is the whole connection.

What you need

• A dedicated graphics computer. Any laptop or desktop with an HDMI output and a modern browser. It does one job: show the output page. Don't use it for scoring, email or anything else.
• An HDMI cable to a free switcher input. If the switcher is far from the computer, use a good active cable or an HDMI extender. Long passive HDMI runs are a common source of dropouts.
• A switcher with a chroma keyer. Check your switcher's manual. Chroma key (keying on a color) is what removes green. A luma key works on brightness and is meant for black or white backgrounds, so it won't give a clean result on green.
• Internet on the graphics computer. The output is a web page that updates live.

Set up the graphics computer

1. Match the switcher's video format. Most switchers run at one resolution and frame rate for the whole show, often 1080p at 29.97, 30, 59.94 or 60. Set the computer's HDMI display to 1920×1080 and the same frame rate. Some switchers scale mismatched inputs, many don't, and a mismatch usually shows up as a black input.
2. Use extended display. Set the switcher feed as a second display, not a mirror. That way the laptop screen is free for you, and the HDMI display shows only the graphics.
3. Open the output full screen. Drag the browser window onto the HDMI display and go full screen (F11 on Windows, the green window button or Control-Command-F on Mac). Check that no address bar, tabs or taskbar are visible.
4. Hide the cursor. Move the mouse back to the laptop screen. A cursor parked on the green display will end up on air.
5. Silence the computer. Turn on Do Not Disturb or Focus mode, close chat apps, and turn off system sounds. A notification pop-up keys over the game just like a graphic.
6. Stop sleep and screen savers. Set the display and computer never to sleep while on power, and keep it plugged in.

Key the graphics in the switcher

Every switcher's menus are different, but the steps are the same idea:

1. Choose a keyer. Many switchers have upstream keys (part of the program, affected by transitions) and downstream keys (on top of everything, after transitions). A scorebug usually belongs on a downstream key so it stays put while you cut and dissolve between cameras.
2. Set the key type to chroma. Set the fill source (and key source, if asked) to the input with the graphics computer.
3. Pick the green. Use the switcher's color picker or sample tool on the background. Because the green is a flat computer color, not a lit green screen, it should key cleanly with little adjustment.
4. Tune the edges. Adjust the key's gain, clip or similar controls until the green is gone and the text edges are clean. Turn spill suppression down if it starts tinting your graphics.
5. Turn the key on. Put it on air and check it on the program monitor over a few different camera shots.

Leave the key on all game and control what's visible from the scoreboard dashboard instead. The scorekeeper can show or hide any graphic from the Overlay Visibility panel, or go to break in one tap. When nothing is showing, the graphics input is pure green and the key shows nothing.

Watch out for green in the graphics

A chroma key removes a color everywhere it appears. If a team's colors are close to the key green, parts of their scorebug panel can turn see-through.

• Check each team's colors on the program output before the game, not just the scorekeeper's preview.
• If a team's green is being keyed, tighten the key so it removes a narrower range of color.
• If that doesn't fix it, pick a darker or lighter shade of the team color in their settings for broadcast use.

Team colors and logos are set once per team and carry into every graphic on the Starter plan and up, so a fix you make once holds for the season.

Test the whole chain

Rehearse with the real switcher, cables and computer, not a substitute:

• Have the scorekeeper change the score, run the clock and show a full-screen graphic while you watch the program output.
• Cut and dissolve between cameras. The scorebug shouldn't flash or disappear.
• Unplug and replug the HDMI cable. Note how long the switcher takes to see the signal again, so you know what a cable bump costs you.
• Watch the actual stream or recording, not only the switcher's monitor. Fine edges can look different after encoding.

If you stream school games, confirm the streaming rights with your athletic director or state association first. If you run OBS on another production, the same graphics work there as a browser source; see adding a scoreboard overlay to OBS. To put score buttons on physical keys for your scorekeeper, see controlling graphics with a Stream Deck.

Switcher graphics checklist

• Graphics computer used for graphics only, on power, with internet.
• HDMI display at 1920×1080 and the switcher's frame rate, set to extended.
• Green-screen output open full screen, cursor moved off, no browser bars.
• Notifications, system sounds and sleep turned off.
• Chroma key set on the graphics input, ideally a downstream key.
• Edges tuned and team colors checked on the program output.
• Score changes, cuts and a cable unplug tested in rehearsal.