Reprinted from the April 2009 issue of Church Production Magazine
Video switchers are essential whenever you want to change from one video source to another in the middle of a worship service. For any church that wants to use the same projector to display IMAG coverage of the pastor as well as DVD content or song lyrics, a switcher will come into play. Switchers are the traffic cops that route inputs (video sources) to outputs (display, recording and playout devices). They also can layer video or graphics on top of other video, and generate and apply transitions that range from simple wipes to complex three-dimensional effects.
Any all-in-one live production system that you might consider is based around a production switcher. You’re probably familiar with the general functionality and, at least in the abstract, the operation of a switcher. It’s used to switch between video sources such as cameras, DVD players, and computer video sources. Often a switcher generates and/or plays out graphics and transitions between different video sources. There are several rows of colored, backlit buttons, often a joystick and a T-bar controller, and at least a couple of monitors nearby for previewing your sources before executing a switch.
A production switcher is a video switcher that is designed to output a video program signal that’s appropriate for television broadcast. Other terms you might encounter include “routing switcher,” “scaling switcher,” and “seamless switcher.” (Another term, “A/V switcher,” has traditionally referred to any switcher with integrated audio mixing. Today the term refers to a variety of different production switchers that aren’t primarily intended for broadcast applications.) At this point, the biggest difference between seamless/scaling switchers and production switchers might be their pedigree. Seamless switchers were originally designed for switching events for live display to a screen, and not necessarily for broadcasting or recording. Today they often facilitate video and computer graphics that are displayed in non-standard dimensions, such as matrices of projectors that are edge-blended to generate a single image.
Although a professional systems integrator would certainly be able to devise a system that’s appropriate for broadcast around a seamless switcher, this article focuses on production switchers that are designed around a live-television paradigm.
So Many Questions
Whether you’re looking to integrate professional-level graphics and broadcast your services on cable for the first time or simply devising a way to switch between a single camera, a DVD player and song lyrics on a laptop, your church is in the market for a production switcher. It’s time to figure out your goals and needs. What are the right questions to ask?
“What do you want to put into the system, and what do you want the output to do?” asks John Stapsy, managing director of Datavideo, a company that manufactures switchers that are particularly popular with smaller churches. “Do you want to record it, cable-cast it, project it, have large monitors in the same room, monitors in a different room?” According to Stapsy, a holistic approach to your video system is best. A switcher has a finite number of video inputs and outputs, and might or might not include conversion gear that converts a widescreen aspect ratio to a 4:3 window (or vice versa), or allows it to input a DVI signal from a computer. The type of switcher your church needs will be determined by the rest of the video system—How many cameras do you need? What formats can they output? What are you doing with the video? Do you need separate programs for IMAG (a clean feed of the pastor and song lyrics) and for webcast or broadcast (a feed with overlaid graphics and shots of the congregation)? What level of graphics do you want to produce? Do you want to do high-definition switching now, or in the near future?
This is just a start, of course. It’s difficult to put production switchers into the types of classes that cameras fit into more easily—there are highly sophisticated $100,000 switchers that do little else, and very basic $10,000 switchers with integrated multi-viewers and character generators. Then, of course, there are very basic switchers that do little else but switch video.
There are high-definition switchers that can integrate standard-def signals and ones that cannot (at least, not without some outboard conversion). Without the room to discuss every option, what concludes the article are descriptions of a few representative switchers at various price levels. Before that, I’ll address a few common terms and concepts that you’ll encounter as you research production switchers.
Graphics and Effects
Once you start considering your live graphics needs, you’ll come across terms like 1 M/E and key and fill graphics. M/E means mix/effects busses. M/E busses or banks are areas in a switcher where effects can be programmed offline.
Key and fill graphics are the means by which graphics are composited over a live video signal: the key is a layer that cuts out a portion of the main video signal so that graphics—or another video signal—can be filled in (using a fill layer). Each M/E bank of a switcher traditionally has offered two key layers, but more recent digital switchers offer three or four per M/E.
Typically, only productions that are extremely graphically complicated will require 2 M/E (or more) and the attendant higher price tags. But some churches use 2 M/E switchers to create two different programs simultaneously—perhaps a clean (graphics-free) feed for IMAG in the sanctuary, and a feed for broadcast with graphics overlaid.
Video Delay
A video switcher is a device that allows an operator to select among two or more video sources to send a signal to a display instantaneously—or almost instantaneously. Depending on the video format used and the path of the signal, there might be some noticeable latency. In IMAG situations, this latency might manifest itself as lag time between the moment a pastor raises his arms and when the projection screen reflects his action.
If the video system in your church is strictly for recording, broadcast or webcast, or even transmission to an overflow room, video delay need not be a problem. But for IMAG—when the congregation can see the pastor and his video likeness simultaneously—latency is distracting.
This potential latency is one of the downsides to the digital A/V world that most of us now inhabit. “There’s just delay all over the place when you have to assemble a studio,” says Ken Swanton, president of Broadcast Pix. With analog video sources, technicians had to match the horizontal phases of the cameras to avoid generating a visible “rollover” at the moment of a switch. (Latency was still a challenge at other points in the system.) Now digital switchers have an “autophase range” that adds latency to the video system. The larger this autophase range, the greater the tolerance for matching the phases—but the greater the latency as well.
Then there’s also the issues of compression and conversion. If at any point between your camera and display there’s a conversion of the aspect ratio, there’s the potential to introduce latency into the video system. Likewise with any change from interlaced video to progressive video. Compression, such as that of HDV and DV video, is a particular killer when it comes to latency.
Luckily, many cameras today shoot in progressive mode to match the progressive video that projectors beam. And some switchers can keep the signal progressive as well, though not all can.
To avoid compression-induced latency, the simplest thing to do is avoid FireWire-based switching and any thoughts of using your HDV camera’s HDMI outputs. Instead, use the camera’s integrated component or S-Video outputs, which almost all switchers accept as inputs. HD-SDI is a great option if you’re planning to use HDV cameras, but only the higher-end HDV models have such outputs.
Synchronizing audio with the video is somewhat easier than eliminating video latency from the system. Most switchers have some sort of set-and-forget dial to delay audio to match it to the typical video delay. As a whole, video delay is something to consider at the beginning of your thought process: Can I afford the type of video-switching system that will make my IMAG video acceptably synchronized with reality?
High-Def Now or Later?
“Future-proofing” is a phrase that’s common to marketing literature. Essentially, future-proofing means buying more now so that you might not have to buy again later, when your church presumably adopts a new technology. For video switching, this means purchasing a switcher that can handle both HD and SD formats, whether both simultaneously or either/or after a reboot. Perhaps you need a new switcher now, and you’ll likely have money to buy high-def cameras a year or two down the road. In this specific case, buying a mixed-definition or switchable HD/SD switcher might be the right move.
But remember that as time marches on, you get more bang for your technology buck. Just think how much the prices of HD camcorders have dropped in the last decade, or how much a 1GHz computer processor once set you back. If an upgrade to high-def is little more than a vague plan for your church, it might be best to buy a standard-def now and acquire a high-def switcher when the time comes.
Simple to Complex
Once you’ve determined your church’s live switching needs, it’s a not-so-simple matter of finding a switcher—or all-in-one production system that includes a switcher—that fits the bill for your budget. Here are a few examples to sketch out the more affordable end of the market for production switchers.
The simplest video system requires the fewest inputs and outputs. For these production environments, the market offers gear that fits. Datavideo makes the SE-500 analog switcher, which retails for around $1,100 and handles four inputs and four outputs. Inputs for a 4x4 video switching system in a church would probably be two cameras, a DVD player, and, via a VGA-to-S-Video converter, a laptop or desktop computer with song lyric software. The switcher’s outputs would likely comprise a DVD or hard-drive recorder, a projector or other display, and perhaps an encoder for Web streaming. Composited graphics don’t come into play with that model. A (somewhat) comparable all-in-one production system, NewTek’s TriCaster Pro offers three video inputs, three VGA inputs, and component, composite, S-Video and DVI output. At $7,995, this costs a fair bit more.
According to John Rhodes, Panasonic’s product line business manager for switchers and system cameras, about 100 churches have adopted the Panasonic HS400/400A switcher, including Willow Creek in South Barrington, Ill., and Redemption World Outreach Center in Greenville, S.C. The high-def and/or standard-def HS400A starts (at about $10,000) as a four-input, four-output switcher, but its modular nature allows users to add cards to the unit to expand it to eight inputs and eight outputs. There’s also the option for a DVI input card, which integrates computer-based graphics into the switcher. DVI output, also an option, helps match the output to the native resolution of a projector.
The HS400A’s keyer has a 3D effects generator built in for either upstream or downstream effects. Another important feature that’s included is the built-in multiviewer, which allows control rooms to preview up to 10 sources on a single large screen. “We do recommend that people get a good-quality small monitor for program output for checking the color, etc.,” says Rhodes. Panasonic is introducing a 16-input version of the switcher at NAB this month; Datavideo is also introducing a 16-input HD-SDI switcher at NAB.
Ken Swanton says that though Broadcast Pix initially marketed its switcher/live-production systems to broadcasters, churches all over the world have bought its units. “We have lots of churches that go onto big screens, we have lots of churches that go onto cable TV, and we have lots of churches that go out to the Internet—or some combination of those,” he says.
The entry-level Broadcast Pix system, the Slate 100 (starting at $11,000 for SD, $14,400 for HD), does not have a hardware console. Instead, users get a specialized keyboard with overlaid functions. Because the system includes a multiviewer, users can also employ a mouse or a touchscreen monitor to drive the interface. The next step up in the line is the Slate 1000, essentially a Slate 100 with a traditional switcher panel, and after that it’s the Slate 5000, which has a 2 M/E switcher. Broadcast Pix believes in the all-in-one concept; that’s why the company integrates components such as aspect conversion, a clip store, a multiviewer and a format conversion into the units as standard.
Trevor Boyer is a freelance writer living in Brooklyn, New York. He likes to write professional A/V and video production stories (like this one) that can be reported via subway travel.