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What is Live Switching?

Streaming Media Producer kicks off its "What Is...?" series tackling essential topics in the streaming media production world with a look at live switching, touching on the differences between switching and mixing, assembling the components and crew of a live switch, and the basics of "punching" a multi-camera show or event for live delivery.

With a one-man-shop, the director is also "punching" the show, so called because in larger productions, there is a dedicated person, called a Technical Director, who punches the physical buttons on a very complex-looking, very large video mixer.

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A Ross 3M video mixer

And don't forget the audio. Whether it be several corporate bigwigs on stage, a whole band, recorded music that needs to be played to the audience, or all of the above, there's audio mixing that needs to be performed live as well.

Very often, there are graphics to show on the screens, or presentations that need to appear on screen, as well as be recorded and streamed to other audiences—for example, in faith-based productions when scripture passages need to fill the screen, or corporate webcasts.

While many companies have designed hardware that can handle recording and playback out of one box, such as NewTek's TriCaster family of production and streaming appliances, soon one person simply cannot operate all the gear needed to run a live event. No matter how comprehensive they make the hardware or software interface, the nature of live events is that unexpected things happen. It's impossible to adjust audio levels while mixing video, and then make changes to the order of graphics that need to be played back, or lighting changes to the room to darken the stage during video playback.

For an annual Chamber of Commerce meeting I worked on, there was an audio operator, a lighting operator, the director of the video show, a person handling computer playback of slides, and a second video operator handling video clip playback and what appears on the IMAG screens in the hall. That's five people, not counting the camera operators, and the audio crew in the hall moving the microphones around.

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The video and audio crew switching the Chamber of Commerce awards

Then you also have to consider communication between all these disparate people so that the director can tell the camera operators what to do, or someone on stage can tell the director that Mr. CEO isn't there yet and the director of the show can run a video clip to fill time.

So live switching can be as simple as one person, on one computer, choosing between two or three sources, and scale all the way up to insane levels, like the Olympics broadcasts where multiple events happen in multiple venues at the same time, and footage from one "pool" of camera operators is fed to a "video village" where it's distributed to broadcasters from around the world who translate and comment on the activities going on for live, streaming, and taped audiences that could number in the billions.

Connecting the Live-Switching Production Pieces

Whether you're using a piece of software in a computer, or a hardware video mixer, the switching process is essentially the same for video and audio when it comes to connecting capture and mixing devices.

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Anthony Burokas switching an event

You attach the cameras and sources to your mixer. Let's just say you have two cameras, and an output from a computer with a slide presentation on it. The two cameras can be a wide shot and a close-up of the presenter. This way you do not need camera operators, but having someone operate the camera to change the shot, or even zoom in while the shot is live, certainly makes the production more interesting than two "locked off" shots that never move.

The audio could be a lavaliere microphone on the presenter, and the audio output of the laptop because the presenter has some testimonial audio clips in her presentation. These feed the audio mixer and, in this case, you would adjust the levels so they sound good and then, most likely, leave them both turned up for the whole production.

The video mixer would be used to select between the wide shot, so we see the whole presenter-including her hands, and a closer shot where we can more closely see her facial expressions. Then, when they refer to a chart or a graphic, you can mix or dissolve to the image of the chart that is coming from the computer.

If needed, you can also use "picture-in-picture" (PIP) to put a small box on the screen with the close-up image of the presenter over top of the background of the chart so the viewer can see both. Or, if a chart is simple, you can put a small PIP of the chart in a corner of the image over the speaker, just for reference to what the she's talking about. Alternatively, you can just mix full-screen between the three sources as you see fit.

This is where the director makes the choices and, with live streaming, or live events, there is no "do-over." If you push the wrong button, or cut to the wrong camera, it's done and you can't edit it out. You just need to keep your cool, and quickly (or smoothly) move the program to where you intended to go in the first place.

This is also where planning and preparation pay off.

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Switching the Texo Awards program at Cowboys Stadium in Dallas.

Do you have backups for your video playback? On the Texo Awards shoot shown above, I had two computers set up identically, both playing the same content at the same time. The operator had to hit the space bar on both, manually, through the whole show. Both computers were connected to the video mixer on two different inputs because if one computer crashed, or glitched (which they do when you least expect it), I could tap one button and switch to the other feed.

Do you have backups for your audio? Extra microphones? An audio mixer big enough to handle the sources you have, and then some more that always show up at the last minute? All are essential if you want to pull off a smooth, professional live-switched shoot.

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