Linear HD Editing: The Line Starts Here

Don't discard those linear editors yet

AMES, IOWA: I thought I'd start this journal out preaching a little heresy and talk about linear editing and HD. We are constantly bombarded by statements that digital is better. Digital is faster. Digital makes things easier. I generally hear these statements from the same people that use Moore's law to extrapolate how the cost and speed of digital technology will be cheaper and faster in just 18 months. Gordon Moore's original paper ( was published in 1965, and it focused on the trend for increasing numbers of transistors on silicon. In addition to being a brilliant look ahead at a very new industry, it was also one of the catalysts for Intel's departure from being a memory chip manufacturer to focusing on microprocessor production. The commoditization of memory meant lots of competition and low profits.


So, is digital better? The answer is, "It depends." If we face the fact that life is analog, then we have to accept that when we create a digital sample, we are losing data. No matter how fast the sample rate or how many bits are in the sample, there is always a gap in time and resolution between samples. So in the purest sense, digital is a compromise in quality by its nature. On the other hand, if the compromise is imperceptible, then the sample can be copied and manipulated over and over with no further degradation. That certainly is better than what happens in the analog world when we try to manipulate our samples. So I would postulate that digital and, for that manner, analog are by their natures neither good nor bad. The question then becomes, are they appropriate? Are they the right tools for the job?

Early in my television career, I was working for a small TV station in Honolulu. While installing a microwave antenna at our transmitter site, a coworker of mine who had been in the Navy asked me to hand him the "crescent hammer." After laughing for a few moments, he explained that on a Navy ship, virtually every tool becomes a hammer at some point in its use and when you're trying to get the job done, you use the tools at hand. Now, the crescent wrench may work but it may not be the appropriate tool for the job.

Let's look at digital nonlinear editing as an example. IPTV has a number of nonlinear editors. We have an Avid DS/HD and a Final Cut Pro HD. We also have three Avid SD systems and a Final Cut SD system. The beauty of nonlinear editing in the digital domain is that the editor can instantly jump to any point without having to scan through all the material. This is a great feature, but to get to that point, all the material that is being accessed must be digitized, and this process takes time and space. The material still has to be scanned to find the segments that are going to be used. In most cases, this means that virtually every piece of material that was shot ends up being scanned, even if we know it's not going to be used because it is inconvenient to stop the ingest process unless, of course, the material was pre-scanned, which takes time.

I am not crusading against nonlinear editing; I am trying to prevent the "crescent hammer" syndrome from being applied. There are times when either for sake of expediency or personal choice that a linear editor might be preferred. IPTV continues to run a linear editing suite but, because we have started producing virtually all our local content in HD, it gets very little use. We have actually been at a crossroads of sorts trying to decide if we should even look at linear as we continue our DTV transition at the studios. Our linear suite is based on a Grass Valley 141 editor, GVG 110 switcher and a fairly typical assortment of tools. When we first looked into HD editing, our initial plan was to convert this suite to HD while maintaining its current analog/SD functionality. I made a trip up to Milwaukee Public Television to take a look at a linear suite they had online that used their Sony editor and a Snell and Wilcox switcher/effects system. By using the configuration options in the Sony editor, they were able to switch between the two operations fairly easily. An added advantage was that the editors were very familiar with the operation of the linear editing system so there was very little in the way of a learning curve. On comparing their Sony editor with our GVG, we realized we could essentially do the same type of operation and begin creating local HD content immediately. Unfortunately, this was also about the time that the bottom fell out of the economy and money became tight so we were forced to put the project on hold.


Recently we began working on converting our studio to HD. We have had on-site demonstrations of HD cameras, graphics and production switchers. The most recent switcher we've looked at is the Sony 8000 HD model. It can be configured with up to four full function M/E banks. If you've looked at switchers in the digital era, you realize that what is incorporated in a new M/E bank will include multiple levels of keying, stillstores, DVE and such. Given that we're looking at replacing an analog system based on the GVG 250 switcher, one could argue that a single M/E 8000 or the like could replace our 250 and still supply added capabilities. Of course technical directors always want one more M/E and the demos always involve a fully loaded model--so somewhere in the middle is what we probably need. But while talking with the Sony reps about the switcher they mentioned that the same frame could have multiple control panels and that individual M/Es could be assigned, so I started thinking about the linear suite again. I mentioned the availability of control via the GVG 141 editor for a linear suite and was pleased to find out that not only can it be accomplished, but that a software editing package is available for the 8000 that integrates editing and machine control.

This really added an interesting spin to our thinking. Despite the fact that IPTV produces a great deal of local content, much of the time our online production room sits idle. The same is now true of our linear suite because of its inability to work with HD. It appears that with a little advanced planning and workflow analysis, we may be able to convert both our online production and linear editing facilities to HD and meet the needs of all segments of our production community.

Bill Hayes, director of engineering and technology for Iowa PBS, has been at the forefront of broadcast TV technology for 40 years, 23 of them at Iowa PBS. He’s served as president of IEEE’s Broadcast Technology Society, is a Partnership Board Member of the International Broadcasting Convention (IBC) and has contributed extensively to SMPTE and ATSC.  He is a recipient of Future's 2021 Tech Leadership Award.