But alas, the audio biz is just a small slice of the technological pie. That’s why we are at the mercy of our favorite pasticceria: consumer electronics. This means that professionals — specifically in the audio field — reap the benefits of consumer technology as it trickles up, rather than the other way round. Take DAT, for example. A failed consumer-oriented product — it survived the battle of lawyers, record companies and government. (The acronym SCMS — that annoying copy protection scheme pronounced "scums," seems more than appropriate here.) Had DAT penetrated the consumer market, the machines that we use would cost about half as much. (Think about the price of a VCR!) For this reason, it is in our best interests that DVD succeed because as a market success story, it can deliver more sonic gain with less financial pain. (Projected prices for initial DVD players for computer use will be $1000.)
There is one more point I can only touch on briefly. Because Dolby and DTS and Sony are all vying for a slice of the DVD pie, it's the format wars that are holding back the format are about licensing. Everyone wants to be the default format because, for example, every audio and video tape with the Dolby Logo and every piece of hardware with Dolby decoding chips returns a royalty to Dolby.
MORE THAN JUST "SLEIGHT-OF-HAND"
Advances beyond the current state of digital recording — improved bandwidth and real time signal processing, for example — have been hampered by the simple fact that the most available and affordable DSP chips are also those used for consumer electronic tasks like Surround Sound. For both shear enjoyment and as a mixing tool, Surround is a personal favorite. But if you didn’t know, it is also just an audio card trick.
In its most basic form, Surround requires four identical monitors that can be connected to any stereo system with a simple wiring variation (visit http://www.tangible-technology.com). All of the brand-name accoutrement are no more than sleight-of-hand stereo with "steering/logic" (computer-assisted panning) and delay, not four discrete channels. Why DSP is involved I’ll never know. Do consumers really add reverb to their tapes and CDs?
WHAT’S IN A NAME?
What started as the Digital Video Disk is now known as the Digital Versatile Disk. I’ve seen the "video" and it was pixelated. Why demo a system with obvious flaws? Could it be that double-sided, multiple layer DVDs are not yet ready? Why else would manufacturers try to fit 133 minutes on the single side of a disk? Too much data compression looks about as fab as recording at SLP.
FYI, the laser disc is analog technology that has much more resolution (detail) than VHS. I don’t currently own a laser disc player, but I certainly won’t be investing in DVD if the video is so obviously compromised. At present, DVD is much better suited as the designated replacement for the CD-ROM. (Players and new titles appear should be appearing soon.) Data compression is appropriate in applications such as the internet where speed and data-thriftiness is more important than accuracy.
Another failed consumer format, the Minidisc, found a place in the radio industry as a replacement for "carts," the endless loop tape cartridge used for commercials. Even with digital compression, the Minidisc will be a welcome improvement over the flaws of analog cassette tape currently used in "personal" multitrack recorders.
LET’S TALK ABOUT SEX, BAY-BEE
All right, so maybe sex is the only way I could lure you into a paragraph
loaded with numbers. Table One lists the data rates for technologies past,
present and future. There are four DVD options from single-sided, single
layer to double-sided, double-layered. One side of a digital versatile
disk holds about six times the storage capacity of a standard compact disk.
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28.8k, 33.3k
& 56k /sec
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128 kbits / sec
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73 min / 771 MB
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10.575 MBytes / min |
1.41 Mbits / sec
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146 min / 1.54 gig
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21.15 Mbytes / min
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2.82 Mbits / sec
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146 min / 3.08 gig
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42.3 MBytes / min
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5.64 Mbits / sec
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133 min / 3.78 gig
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35.17 MBytes / min
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4.69 Mbits / sec
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133 min / 8.50 gig
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63.9 MBytes / min
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8.52 Mbits / sec
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133 min / 9.40 gig
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70.67 Mbytes / min
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9.42 Mbits / sec
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133 min / 17.0 gig
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127.8 MBytes / min
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17 Mbits / sec
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uncompressed composite video |
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133 min / 598.5 gig |
450 Mbytes / min
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120 Mbits / sec
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Please note that the "average" throughput for DVD — 4.69 Mbits/sec — will allow 133 minutes on a single-sided disk. Using Variable Bit Rate (VBR) technology and MPEG-2 compression, DVD mastering engineers will decide (in conjunction with software) to raise the bit rate to accommodate detail (fast moving images) and lower it for nearly still images. At this rate, 133 minutes of video — with three channels of audio and four sub-title channels — will fit on less than 4 gigabytes.
NOTE:
From the four standard disc capacities, I extrapolated data rates that would accommodate video projects that demand greater detail using less compression.
When DVD does become available to the audio industry, it will have no problem storing digital audio. Based on the data rate for a standard 44.1 kHz CD (1.41 Mbits/sec), doubling the sample rate to 88.2 kHz will do the same to the data rate (2.82 Mbits/sec). A 73 minute classical recording will take up a mere 1.51 gigabyte of space. With a little imagination, why not 90 minutes of discrete four channel audio (3.08 gigabytes)?
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Part 1:The Phonograph | Part 2:Magnetic Tape | Part 3:The Mastering Process | Part 4:CD |
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