Sarasota PC Monitor
Tech Talk (9/05)
Adding to the DVD Confusion: Blu-Ray, HD-DVD
by Brian K. Lewis, Ph.D.*
Member of the Sarasota Personal Computer Users Group, Inc.For several years our recordable DVD media choices have been DVD-RAM, DVD+ and DVD-
These all have a capacity of 4.7 GB of storage on a single sided disc. Recorders are now available that can write double-sided discs with 9.4 GB capacity. By this time next year, you should be able to buy DVD discs that have a capacity of 15 GB of storage. Toshiba plans to have HD-DVD write-once discs and recorders on the market in the U.S. sometime during the first half of 2006. This will add to the already confusing array of DVD disc types. The worst part being that none of these discs are compatible with each other. Only in the last couple of years have the computer optical drive manufacturers managed to produce drives that will read and write both the DVD+ and DVD- formats. Now with two new new formats emerging in the DVD marketplace the degree of confusion is escalating. In addition, the commercial stereo TV players/recorders are further behind and generally are fully compatible with only the + or - version discs.
So let's take a closer look at what is happening in the DVD format arena. First, the television broadcast market is converting to high-definition TV. In order to record these broadcasts using DVD recorders, the discs need a greater capacity. Secondly, the Hollywood movie studios want to produce DVDs in the high-definition format. Both of these recording formats require discs that have 15 GB of storage or more. Unfortunately, the studios, the disc makers and the drive manufacturers are split between two competing formats. In fact, they have been at odds over these formats for at least two years and have been unable to reach any compromise. It now appears that each group is going to go its own way in producing discs and recorder/players for the consumer market.
The two competing high-definition formats are Blu-Ray and HD-DVD. The principle backers of HD-DVD are Toshiba and NEC. This format is also backed by the DVD-Forum which is the industry association that created the DVD format. Don't forget, however, that the DVD format also includes the incompatible DVD+ and DVD- specifications. Only after months of consumer confusion did the optical drive manufacturers finally start producing recorders that could read/write both of the competing formats. Not every DVD player can read both formats so some care and testing is needed to determine which format your player can handle best.
HD-DVDs are similar in structure to current DVDs and can be manufactured without a change in equipment. This helps keep manufacturing costs low. The increase in storage capacity is due to the use of a blue laser instead of the red laser used in current DVDs. The shorter wave length of the blue laser allows the pits and plateaus, or "lands", on the disc to be smaller and closer together. So you can pack more information onto the discs without any change in its size. The net result is a disc that can store 15 GB on one side or 30 GB on a dual sided DVD. Interestingly, a 135 minute movie will consume about 12-13 GB of storage. Now add to this the space required for sound tracks (about 5 GB), including Dolby Digital and DTS, multiple language tracks and extras. At that point you have probably come very close to or exceeded the 30 GB capacity of the two sides of the HD-DVD disc. However, with a TV set-top recording device you could record up to 8 hours of high-definition television on a dual-sided HD-DVD disc. Unfortunately, it may be several more years before dual-sided discs are available and at least that long before HD-DVD recorder/players are available for your HD-TV recording. All of this also depends on the outcome of the competing format wars. The Blu-ray Disc Association includes most of the major consumer electronic companies plus a large number of the movie studios. For example, Sony has announced it will support Blu-ray in its Play Station 3. As you might guess from the name, the Blu-ray Disc uses a blue laser just as does the HD-DVD. However, the disc capacity is much greater than that of the HD-DVD disc. Blu-ray can store 25 GB on a single side or 50 GB on a dual sided disc. The Blu-ray laser also produces smaller pits and "lands". Thus the data is packed closer together and that produces an increase in storage capacity. Additionally, they have indicated that they expect to eventually increase the capacity to 100 GB per disc within the foreseeable future. In order to produce these discs manufacturers must install new manufacturing and replication equipment and processes. At least initially, this will increase the cost of Blu-ray discs and therefore, the cost of any movies released on them. One other aspect of the Blu-ray disc that may be important is that the recording layer is much closer to the surface of the disc. This might make it more sensitive to scratches than current DVD media. The Blu-ray discs and recorders may not make it to the market until mid-2006 or later.
There are other considerations in this whole format change. One of the most important to consumers is backward compatibility. In other words, you want your current DVD collection to play in any new high-definition recorder/player you might purchase. Both HD-DVD and Blu-ray use the same video and audio compression schemes as current DVDs. However, it is still up to the recorder/player manufacturers to produce equipment that is backward compatble.
According to a Blu-ray consumer survey, one request was for a disc that could be played either in existing equipment or in high-definition equipment. In other words, one side would have the current 4.7 GB capacity and the other would have the 25 GB high-definition capacity. This would be applicable only to pre-recorded discs (DVD-ROM). The Blu-ray disc specification already allows for a combo disc with a 25 GB BD-ROM on one side and a 8.5 GB dual-layer DVD-ROM on the other side. (Incidentally, Blu-ray refers to its high-definition discs as BD for Blu-ray disc; BD-R, BD-RW, etc.) Blu-ray also has a combo which includes a 700 MB CD-ROM instead of the DVD-ROM.
Another compatibility issue is the ability to play a high-definition disc in any device. That means you can use it in a set-top recorder, your PC or a gaming console. However it will be a real nightmare if both formats reach the market in the current state of incompatibility. Especially if the movie studios remain split as to the formats they find acceptable. That would probably delay consumer acceptance for sometime. That is something none of the consumer electronic companies or the entertainment companies want to see. Since they can not seem to agree on a compatible format, there may very well be a marketplace war next year.
There is also a copy protection scheme which is being developed. This is the Advanced Access Content System which will be used with read-only discs. HD-DVD has selected AACS for its digital rights management, while Blu-ray has not yet decided on its scheme. AACS was supposed to be completed in March 2005, but has not yet finalized. Part of the delay in releasing HD-DVD is attributed to the delay in the completion and acceptance of the AACS specifications.
There is another advance coming down the road which will probably replace both the HD-DVD and Blu-ray formats. That is Holographic Versatile Disc (HVD). This format uses two lasers, one red and the other a blue-green. These read information from two different layers of the disc. Without getting into the really technical end of this information, let's just say that this technology will increase the storage capacity of the standard optical disc to 3.9 terabytes(TB). That's eighty times the capacity of the Blu-ray disc. In addition, the data transfer rate is faster than today's SCSI or SATA drives. The HVD drive could transfer an entire movie in 4.7 seconds. Or you could fill an HVD disc with 213 DVD movies and burn the disc in about 16 minutes. So, you can see there are major changes coming in the optical drive arena. Let's just hope the manufacturers can get their act together so we don't have the old Betamax-VCR wars that we faced 20 years ago. Unfortunately, at this point in time, that seems to be what we are looking forward to in the next year or two.
So what is a consumer to do? My suggestion is to simply wait and see what happens. If the companies face enough consumer resistance, then maybe they will be forced to compromise. Only through a compromise in the competing formats will the consumer truly benefit. :
*Dr. Lewis is a former university & medical school professor. He has been working with personal computers for more than thirty years. He can be reached via e-mail at bwsail@yahoo.com.
Copyright 2005. This article is from the September 2005 issue of the Sarasota PC Monitor, the official monthly publication of the Sarasota Personal Computer Users Group, Inc., P.O. Box 15889, Sarasota, FL 34277-1889. Permission to reprint is granted only to other non-profit computer user groups, provided proper credit is given to the author and our publication. We would appreciate receiving a copy of the publication the reprint appears in, please send to above address, Attn: Editor. For further information about our group, email: admin@spcug.org/ Web: http://www.spcug.org/The Sarasota Personal Computer Users Group, Inc. has 1,100+ members and was established in 1982. We are members of the Assoc. of PC User Groups (APCUG), the Florida Assoc. of PC Users Groups, Inc., and we are members of the America Online Ambassador Program.
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