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Video Can Learn From Audio - AvNetwork.com

Video Can Learn From Audio

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If you count playing in a '60s rock and roll band, I've been in the pro audio business for 40 years as of this summer. Actually, I've tried to escape a couple of times and failed. Audio always seems to drag me back. With this kind of history, I surprised myself recently by taking up pro video, at least in a small way. I've even designed a couple of video projection systems. No, it's not another attempt to escape from the audio world. I've given that up. Instead, I'm simply doing my best to catch up with our customers, most of whom have been operating (and buying) audio plus video installations for some time.

You may interpret this discussion so far as a sort of disclaimer. I'm about to discuss video engineering as if I knew something about it. I don't, or at least not very much. But, some of what I've learned about video surprised me, so I'm going to take the risk of writing about it and even making a suggestion or two.

Video Is Less Advanced Than I Had Believed
Video is a newer discipline, unburdened by audio's 70 or 80 years of history, and has a growing consumer market to support its research. With a few exceptions like satellite radio, consumer audio seems to be in decline. Video is moving towards high definition. Audio is moving towards iPods. You can understand why I assumed that video engineering was more advanced than audio.

However, I've found that pro video has at least as many incompatible and legacy formats, connections, and wiring schemes as pro audio. Some of them, like NTSC video, are arguably as old and tired as anything in pro audio. Because they won't go away, video engineers have invented special circuits to convert among all of these video formats. There are "upscalers" to convert composite video to component video and "down scalers" to convert in the other direction.

This reminds me of the old days of pro audio where we would put a matching transformer, terminating resistor and passive volume control between the output of a mixer and the input of a graphic equalizer. Why? Just to make sure the two would work together. I'm glad that's over in audio. I don't see any end to this kind of thing, however, in video.

Video Engineering Is Often 'Rule Of Thumb'
I was surprised to learn that video projection systems are often designed without actually measuring the room lighting conditions. For an audio engineer, that would be like designing a voice-paging system without measuring the ambient noise. Will the projected image be bright enough to satisfy the customer? Or, will the projector be brighter (and more expensive) than necessary? If you don't measure the ambient lighting conditions, you're depending completely on engineering judgment.

Yet, of the several designers I talked to, only one carries a light meter. That was consultant Lonnie Theer in Omaha. So, if a professional consultant carries a light meter, I figure I ought to get one. If you're designing projection systems, maybe you should get one, too. I found simple, digital light meters on the internet for $50 to $100.

Video 'Room Combining' Is Not Easy
A hotel customer recently asked me to propose new projectors for the hotel's ballroom. Like many such spaces, this one can be subdivided, and my customer wanted a projector and screen for each half. That way, when the hotel hosts two simultaneous meetings, each would have its own projector and screen.

But, what about a single large meeting that uses the entire ballroom? The typical solution is to install a larger, third projector and screen to serve the combined space. But my customer, who wanted to save money, had a better idea. For the combined space system he asked, "Why not just display the same source through both of the smaller projectors?"

"Good idea," I replied. Then, I started researching how to accomplish this in a cost-effective and easy-to-use way. What a hassle! You're back to the problem of multiple video formats (computer VGA, composite, and even S-Video). Add the problem of transmitting these over distance. Now, figure out a way to switch and control them and make it easy enough that the garden club and PTA can figure out which button to push.

You can do all of this with a video matrix switcher and touchpanel control system, but the cost of these items will easily exceed the cost of the projectors and screens. What we need is something akin to the standard audio room combining products. I realize that a video room combining system would be more complex (and more expensive) than audio, but I think this is a product that would sell.

Video's Path To The Future Will Be Bumpy
Audio is rapidly moving towards digital, but we may have an easier transition than video. We don't have to worry about the Blu-ray versus HD-DVD wars. We'll be glad to record multichannel, high-definition audio on either one. It looks like 1080p will be the ultimate high-definition video standard but wait a minute, isn't that an analog specification? Will 16:9 be the final video aspect ratio? What do we do with all of that left-to-right real estate in a church when all we need is "image mag" for the preacher? And, finally, if DRM (digital rights management) is a hassle for audio, I have to believe it will be a serious problem for video engineers.

Video Needs A 'Boot Camp' School
Yes, there are plenty of good video classes from InfoComm and NSCA, but I'd love to attend the video equivalent of Syn-Aud-Con (Pat and Brenda, are you listening?). I can't study a subject like video engineering without understanding basics like the difference between luminence and illumence and the right way to apply measuring units like foot candles and foot lamberts.

Finally, here's a piece of advice for any audio systems engineer who is still dragging his feet. Video systems integrators won't be out of a job anytime soon. Maybe you should join them.

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Live and Learn

In 2012, the New Trier Township High School, in Winnetka, IL, set out to overhaul the EPI Center, a collaborative meeting space on the third floor of its Winnetka Campus.