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Letters | Audio Clinic | Tape Guide | Signals and Noise | Also see... FAST FORE-WORD (Dec. 1998) Ever have a relative so relentlessly annoying that you hated to see him coming? That’s the way I feel about DTS. I don’t have space to recount everything that has pushed me to this state of dyspeptitude, but I do want to talk about the most immediate cause, which is DTS’s stand with respect to DVD-Audio. I am about to leave for Japan to attend a technical seminar on the DVD-Audio specification, which is now essentially complete. The good news is that the DVD Forum’s Working Group 4 (WG-4) has polished away some of the flaws in its original proposal. Most important among the improvements is adoption of a lossless compression scheme, which is necessary to achieve adequate playing time and flexibility with five or six channels of high-data-rate PCM. (It seems likely that many producers will want to go with 96-kHz/24-bit coding on all channels.) WG-4 has chosen Meridian Lossless Packing (MLP) for this chore. And that’s where the plot thickens. I have in hand a copy of a letter dated September 10 from DTS CEO Dan Slusser to WG-4 chairman Bike Suzuki (of JVC). I can’t convey the full flavor of the letter without quoting all of it, but it contains phrases like “injunctive relief” and “appropriate treble”. The key sentence is near the end: “We have no desire to participate in litigation; however, if it becomes our only option, I would then have no other real choice.” Translation: Buy our kibble, or we’ll shoot your dog. My favorite part: The letter signs off with “Best personal regards?" Charmed, I’m sure. DTS wants to be part of the mandatory standard (like PCM and Dolby Digital are in DVD-Video), not an optional coding format (like it is in DVD-Video). In DVD-speak, the “mandatory standard” defines those things that all hardware for the format must support. For example, all DVD-Video players must be able to play PCM and Dolby Digital soundtracks, but they are not required to handle DTS soundtracks. Apparently DTS is desperate to avoid the same fate on DVD-Audio. The company has made a couple of arguments to support its position. The primary one is that unless its lossy compression system is used, there will not be room on a single-sided, single-layer DVD Audio disc for both a five- or six-channel version of the program and a dedicated two-channel version, forcing producers to rely on DVD-Audio’s automated mix-down feature for two-channel output. Of course, DTS has a distinguished history of questionable and even manifestly erroneous statements regarding matters in which it is hard to believe the company doesn’t have access to correct information (what studios plan to use its system on DVD-Video, for example). But this claim is particularly amazing, since the main point of adopting a lossless compression system like MLP is to make possible exactly what DTS is saying it rules out. These DTS guys are supposed to be data-compression experts. If I can figure out in five minutes on the back of an envelope that what they’re saying is wrong, why can’t they? The second argument is just brazenly preposterous: that DTS would afford DVD Audio full backward compatibility with the existing DVD-Video format. DTS is an optional audio coding system for DVD-Video. No current DVD-Video player (or any contemplated, as far as I know) can deliver analog audio output from a DTS soundtrack, many cannot even recognize a DTS data stream and deliver it to their digital outputs, and many surround processors and receivers lack DTS decoding capability. The irony is that there really is a way to ensure complete backward compatibility of DVD-Audio discs with DVD-Video players, which is to include a Dolby Digital version of the contents along with the PCM tracks. (Like DTS, Dolby Digital is an optional coding format for DVD-Audio.) With MLP lossless compression for the PCM, it usually would be possible to include three complete versions of the program on a single DVD Audio layer: multichannel PCM, two-channel PCM, and multichannel Dolby Digital. And as I noted in the October issue, Dolby Digital is capable of audio quality extremely close or identical to that of CD-standard PCM. As a consumer format, DTS has always suffered from providing too little compression for applications that need audio data reduction (such as DVD-Video) while doing more than is necessary for most applications that are less strapped for bandwidth (such as DVD-Audio). It’s clear from DTS’s strong-arm tactics on DVD Audio that audiophiles and manufacturers should stop putting up with the company’s guff. Earth to DTS: Get out of the way![TOP] Also see:1997 1998
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