by John H. Doyle
What is DVD?
DVD stands for either Digital Video Disc, Digital Versatile Disc, or nothing, depending on what interest group you are asking. DVD is a storage mechanism for digital data that uses the same basic technology as a CD-ROM, but it is capable of holding much more data. You have probably heard of DVD through the home movie market because it is currently most popular, and available, in that market. Ironically, DVD will most likely not last in the Television market that has made it popular because it does not support the resolution of High Definition Television(HDTV), but that is an entirely different discussion.
DVD has relevance in the field of information systems as a secondary storage type with the potential to hold massive amounts of data. To this point, DVD has been used mostly for data-warehousing. In other words, companies have used specialty write once only hardware and discs to save massive amounts of information that most likely never be accessed but needs to be kept on hand for legal purposes.
More and more, the trend in personal and industry computing is moving towards multimedia applications with complex graphics. Games have become amazingly lifelike and, even on standard desktop applications, we have gone from the DOS prompt to GUI's with animated paper clip heads flying around the screen. All of this is great for the end user, but these programs take a ton of memory, and necessitate massive amounts of secondary storage.
With the recent release of rewritable DVD, it is likely that this new technology, with its huge storage capabilities, will replace floppy drives, CD-ROM's, zip drives and hard drives with a single storage standard. Currently, though, not only is there not a unified standard for rewritable DVD, but there are two contentious parties, both pouring millions of dollars into incompatible technologies--and this is only one of the problems with DVD.
In this paper, I will look at how DVD technology works, who owns it, DVD-ROM, the rewritable DVD market , what Divx is, and what the future holds for DVD.
How does DVD work?
DVD is really no more than a beefed up version of CD-ROM. Like a CD-ROM, DVD uses a single spiraling track on a reflective metal surface packaged in plastic. The spiraling track contains pits that are read by a drive laser as values of one or zero(bits). DVD simply increases the data capacity of the disc by packing as many pits on it as possible.
As the pits become smaller and more densely packed, a smaller laser is required to read the disc. DVD uses a 635-nm or 650-nm laser, compared with a 780-nm laser on a standard CD-ROM. Current lasers support double the pits per track, and double the tracks per surface area available on a CD-ROM. DVD further increases capacity by using a more efficient sector format. The basic capacity of todays DVD discs is 4.7 GB, compared with 650 MB offered by CD ROM.
High end DVD's go one step further, using two separate types of technology to achieve even higher data capacity levels. The first technique bonds two .6 mm discs together back-to-back, resulting in 9.4 GB of storage space on a single disk. The second technique creates a dual layer on both sides, the top layer being a semi-transparent layer that a second laser can punch through to read the layer beneath. The dual layer discs bonded together result in a single disc with 17 GB of storage capacity, more than 26X a single CD.(1) Below is a side cut picture of both a single layered and double layered side of a DVD.
Source:http://www.imation.com/dsp/optical/dvd/techbull.html
Who Owns DVD?
Fortunately, DVD is not owned by a single company, so we will be able to able to avoid monopolistic pricing on the product in the future. Initially, there were two standards for DVD technology, but a group of computer companies led by IBM said that they would not support DVD until there was a single industry standard.
As a result, a single standard was developed by a consortium of 10 companies: Hitachi, JVC, Matsushita, Mitsubishi, Philips, Pioneer, Sony, Thomson, Time Warner, and Toshiba. As it turns out, the IBM group's efforts only served to prolong the inevitable, as the DVD consortium companies have split again on standards for rewritable DVD.(2)
DVD-ROM
DVD-ROM is a tested and proven technology. The high-end discs that hold 26X the data as a CD-ROM are less than twice the cost. Still, the disks have not achieved mainstream popularity for a number of reasons.
First of all, the majority of DVD marketing has been focused on the movie player market and has failed miserably. Some reasons for its lack of success are that the product cannot record, Divx(an alternative DVD product) was released and split the customer base, and the slight increase in picture quality is simply not worth the inconvenience and high price. Thus, DVD never reached a level that it could make a marketing push into the Computer market.(3)
The second problem, as is the case with most new computer technologies, is that there is minimal software available that to support DVD. Many analysts and market research firms have concluded that, while there is huge interest in DVD right now, it will not be reflected in purchases until there is more software support. Mary Bourbon, principle analyst for DataQuest, feels that all DVD needs to make a push in the computer market is one "killer app". DataQuest predicts that DVD-ROM drive sales will top 132 million in the year 2002.(4)
The final issue that has really held DVD-ROM back is the lack of an industry standard for rewritable DVD. If the consumer could purchase a DVD-ROM drive today that would be guaranteed to run tomorrow's rewritable discs, sales would be higher. As we will see in the next section, this is not the case.
What is rewritable DVD and when will it be available?
Rewritable DVD refers to the format that allows data to be erased and rewritten in the disc. It is possible through Magneto-Optical technology, a process which uses a laser to heat the inner surface of the disc and magnetically change its charge. Data on the disc can be rewritten millions of times through this process. The technology is currently used by Sony MD audio discs. 1998 was supposed to have been a break through year for rewritable DVD but a combination of performance issues and lack of an industry standard resulted in a virtual no show of the product in the retail market.
In a fine example of marketing running R and D, many of the big DVD companies have been concentrating on speeding up DVD-ROM spin speeds, when there are hardly any applications available to support the current speeds. The biggest performance problem with DVD, where R and D efforts should be focusing, is slow access time in rewritable DVD. Specifications call for average access times of 120ms for DVD-RAM, compared with 85ms for DVD-ROM and CD-ROM formats(5). However, the slow access issue is minor compared with the problems presented by the lack of a common standard.
In April of 1997, the DVD Forum resplit(you will recall that the initial forum was split) into two camps producing two incompatible DVD technologies. The DVD+RW camp is led by Sony, HP and Philips, and the DVD-RAM camp by Toshiba, Matsushita, and Hitachi.
DVD-RAM, the first rewritable technology to reach the consumer market, was released in the third quarter of 1998. The hardware costs $750-$1000, and records onto single-sided 2.6 GB discs that cost about $30, and two-sided 5.2 GB discs, that cost about $50. One drawback to DVD-RAM technology is that the discs require caddies, the same disc holders that can be found on older CD-ROM drives.
DVD+RW is expected to hit the market by the end of this year. It should cost about the same as DVD-RAM but its vendors claim that it will be up to 50% faster. Also, the discs will have slightly more storage capacity(3 GB per side) and will not require caddies.
To further complicate matters, two other high end rewritable formats are expected to be released within the year. The first, called DVD-R/W, is produced by Pioneer. Its discs hold 4.5 GB per side and are guaranteed to run on any DVD-ROM player but will cost between $3000 and $5000. The second, called MultiMedia Video Format(MMVD), is produced by NEC. Its discs will 5.2 GB per side, enough for 2 hours of video, but the product will be marketed to and priced for professional video editors.(6)
Rewritable DVD formats |
|||
Name | Capacity | Companies | Shipping |
DVD-RAM | 2.6GB | Toshiba, Panasonic, Hitachi | Yes |
DVD+RW | 3GB | Sony, Philips, HP | No |
ASMO | 6GB per side | Fujitsu, Hitachi, Sharp | No |
MMVF | 5.2GB per side | NEC | No |
Source: Dataquest |
Web Source:http://www.news.com/News/Item/0,4,27720,00.html
The problem with all of this, in addition to giving you a headache, is that there is no compatibility. The only product that guarantees universal DVD-ROM drive compatibility is DVD-R/W, and none of the formats guarantee compatibility with each other. Based on high end pricing, the average consumer will choose between DVD-RAM and DVD+RW, but the market will not tolerate two incompatible formats. Market analysts believe that , unless the two camps can agree to a common standard, which seems unlikely, a VHS vs. Beta type battle is inevitable, with one format emerging as the market standard. Unfortunately, all that we can do, as the responsible consumer, is sit back and wait.
What is Divx?
Divx is a technology that was produced with financial backing from Circuit City. Thomson Consumer Electronics and Zenith announced in September that their players will support the Divx format. Divx allows the consumer to take home a disk for about $5 and view it as many times as they would like over the next 48 hours. The trick to Divx is that the machine is connected to a modem, and after the initial 48 hours, the owner is charged for each additional viewing. Divx can be thought of as a type of pay-per-view, but without the limitations of pay-per-view scheduling.
Divx has received quite a bit of criticism. Some claim that it is an intentional attempt to prevent the success of DVD while others, including this writer, just think it is a silly idea. Supposedly the rational for Divx is that it will lower the number pirated copies of new releases by offering a less expensive alternative to DVD. Divx also offers "Gold" discs that allow for unlimited viewing which sure sounds like a direct competition effort. Divx does not currently have any computer applications but it is significant in that it brings the Television and the PC one step closer to becoming a single machine. It will not be long until we can "download" digital film data to our television sets. Whether or not Divx will be the technology to do so remains to be seen.
Divx might have some application in the computer gaming market as people could rent a game for 48 hours much like they do on the current gaming systems. This does not seem likely though, because the only advantage over downloading the game is that it may take less time. With current internet connection and CPU transfer speeds, though, this becoming a non-issue.(7)
Why is DVD really cool?
All serious business uses and responsible hardware considerations aside, there is one really cool reason to by DVD. It allows you watch full length DVD films on your laptop. Just think-you have boarded a five hour flight to New York only to find that the feature presentation will be "Ishtar". Assuming that you forgot to bring any stimulating reading material, you would normally be forced to read one of those awful travel magazines. Not so with your nifty new DVD enabled laptop gizmo. Just grab one of your many DVD selections, kick back, and enjoy the flight.
DVD upgrade kits cost from $350 to $500. The drives require a system with at least a Pentium 133 CPU or faster, Windows 95, at least 16 MB of RAM(32 is better), a graphics card that displays at least 800 by 600 DPI with 16-bit color, a PCI slot, a Sound Blaster or compatible sound card, a 5.25 inch drive bay and an IEDE connector(8). Installation is relatively straight forward. If you're interested, there are simple directions in the article "Be First on Your Block With DVD" in the July, 1998 issue of PC World. If your a MAC user, check out "CoolDVD" in the September, 1998 issue of Macworld.
Should I buy DVD?
Let me start by saying that, if your existing system works well, it does not make sense to put a DVD drive in. The current combination of floppy drive and CD-ROM is probably sufficient technology. However, if you are doing a ton of back-up or data-warehousing, you might want to do a price and efficiency comparison with DVD. Below is a comparison of various secondary storage costs per MB.
Removable Storage Products |
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DVD-RAM | CD-RW | Zip | |
Drive Cost | $750 | $400 | $150 |
Cost per disc | $25 for 2.6 GB disc | $20 for 650 MB disc | $16 for 100 MB disc |
Cost per MB | $.01 | $.03 | $.16 |
Other formats it can read | DVD-ROM(some),DVD-R, CD-RW, CD-R, CD-ROM | DVD-ROM(some),CD-R, CD-ROM | Zip disks only |
*Source:
www.computerworld.com/home/features.nsf
For data-warehousing, DVD offers "Jukebox" technology similar to that currently offered with CD-ROM's. Pioneer recently debuted it 100-disc DVD-2 jukebox, a storage system that contains two removable disc magazines and has a total disc capacity of up to 470 GB. The machine can accomplish disc changes in less than 6 seconds and can transfer data at 3.5 MB per second. Such technology can be used either to replace the hard-drive, or for back-up and warehousing. On this system, data is more readily accessible than on current tape systems and, in the long run, costs less per MB of storage.
As cool as they are, rewritable DVD drives are not a smart purchase decision at this point. The biggest reason is the lack of an industry standard. The technology definitely has a lot to offer, but the possibility of betting on the wrong technology is just too risky right now. As one article put it, investing in the wrong technology now might leave you with the computing equivalent of a Beta Machine. If you must be the first on your block with rewritable DVD, go with the DVD-R/W format. It will cost significantly more, but you are guaranteed compatibility with any DVD-ROM format.
What is the future of DVD?
Even with all of its current faults and lack of a common standard, the PC DVD market will most likely grow rapidly over the next five years. Most analysts agree that DVD-ROM will eventually replace CD-ROM. The only disagreement is when it will happen. Mary Bourdon of DataQuest believes that it will depend largely on whether or not DVD-ROM vendors drop royalty fees in an effort to take over the market. Right now, DVD-ROM drives cost $40-$50 more than CD-ROM, but this figure would drop to about $10 without royalty fees.(9)
Another major factor for both DVD-ROM and rewritable DVD, is how quickly a rewritable standard is established. Floppy drives are already becoming a thing of the past and zip drives, while they were a great intermediary solution, will not keep up with rewritable CD and DVD. As with DVD-ROM vs. CD-ROM, rewritable DVD will most likely win out in the end, but it will take significantly longer because of the standards battle. The following is an estimation of future rewritable drive sales from International Data Corp.
Projected worldwide shipments of recordable drives |
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Year | Recordable CD | Recordable DVD |
1998 | 5.2 M | 300,000 |
1999 | 8.9 M | 700,000 |
2000 | 15.6 M | 1.8 M |
2001 | 23.6 M | 4.2 M |
*Source: International Data Corp., Framingham, Mass.
Sources And Links
(2) www.videodiscovery.com/vdyweb/dvd
(3) www.computerworld.com/home/features
(4) Computer Reseller News, July 27, 1998, n800 p107(n)
(5) PC Magazine, Oct. 6, 1998 v17 n17 p68(1)
(6)
www.dvddigital.com/dvdram(7)www.dvddigital.com/articles
(8)PC World, July 1998 v16 n7 p310(1)
(9) PC World, August 1998 v16 n8 p 66(1)