by Steve Church
Munching on bratwurst and sipping a thick German
beer, I first heard about something supposedly new and exciting called NBC. Now this was weird for two reasons:
1) NBC has been around since Mr. Sarnoff created it many decades ago, and 2) I
was sitting in a biergarten near N?nberg and talking with guys from Fraunhofer, the
outfit that invented MP3 ? not people particularly likely to be
familiar with American television networks. Turned out this NBC stood for Non-Backward
Compatible and referred to next-generation MPEG stuff ? 'nother thing
altogether. And what it meant more specifically was that the clever Fraunhofer
engineers had been turned loose to make the best audio codec possible.
This was 1995, two years after Telos intro-ed the Zephyr, transforming the broadcast remotes with its combination of MPEG Layer 3 and ISDN. ?MP3? was first getting noticed on the Internet at this time, too. So, naturally, this was potentially interesting news. What could be better, I asked, than MP3? Already, it seemed to me, we had what we needed. MP3 was a perfect partner to ISDN, offering plenty good fidelity on widely available Telco lines. Will users notice anything? Yes, they said, ?just wait and see, this new stuff will be really something?? Already, they told me, they had lined up cooperation with Sony, Dolby, and AT&T ? so it was pretty clear they were onto something.
Before, with MP3, they had been constrained by a number of things. Part of the filter bank had to be the same as MPEG Layer 2. The bit stream had to be more-or-less compatible with older formats. DSP power had been expensive. But now it was clear that the price of processing was coming down swiftly according to Moore?s Law, and that it would soon be possible to do much more sophisticated calculations in real time than was feasible early in the decade. And more was being learned about audio coding every day as people working with the technology experimented, learned, and progressed to more sophistication.
Before the stein was downed, I agreed that we should work together to get this new coding method into our next-generation Zephyrs. It took some time, but the payoff has finally arrived with the new Zephyr Xstream family ? here, now. Not only does the new Zephyr have the ?NBC? codec ? now called MPEG4 AAC (for Advanced Audio Coding), but the very interesting and useful offshoot, AAC-LD. The LD stands for Low Delay ? and it lives up to the promise, enabling smooth interaction like never before possible.
High fidelity from and to most of the world over cheap and generally available ISDN lines has been a dream realized. Maybe you remember what is used to be like. Remotes used to mean special ?broadcast loops? that were installed only from one fixed point to another, having months long lead times and high cost. Two Telco technicians were usually occupied for hours manually equalizing the circuits. Long distance remotes were a near impossibility: The only vendor was AT&T, and only for very expensive circuits that connected only to a single fixed point, had crazy lead times, and marginal quality. Because of the cost, links with bandwidth reaching above 5 kHz were rare. For a short time, rented satellite uplinks mounted to trucks were being driven around the country in order to get around the Ma Bell confines. This was better, but still expensive, with long lead times, and the sometimes difficult requirement to find a place to situate the truck for an unobscured shot to the bird. (I remember a Rockline remote out of Cleveland where we couldn?t get a shot from the studio and had to get a phone loop to the transmitter site fast ? or lose the John Mellencamp guest appearance that had been promoted heavily. We got the line going about 45 minutes before show time. Talk about a nail biter! One of the inspirations for the creation of the Zephyr...)
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