Blu-ray vs. HD-DVD

The pros and cons

 Supporting companies

Blu-ray is approved and promoted by the Blu-ray Disc (BDA) association which currently has more than 100 members around the world, the most important and board directors are: DELL, HP, Hitachi, LG-Electronics, Mitsubishi Electric, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK, Thomson, 20^th Century Fox, Walt Disney, Texas Instruments, Sun Microsystems, the game giants Electronic Arts, and Vivendi Universal Games.

HD-DVD is endorsed and approved by the DVD Forum, the international association of over 230 consumer electronics, entertainment, software, IT and other related companies around the world. DVD Forum even includes member companies of the Blu-ray association and companies that are backing both of the formats. The format is promoted by the HD-DVD Promotion Group, which currently counts 63 member companies. Some of the most important are: Toshiba, Sanyo, NEC, Paramount Pictures, Universal Pictures, New Line Cinema and the Warner Bros Studios.

So, when we take a look at the supporting companies, then it seems that everything is clear. Blu-ray appears to have an edge because most of the electronic giants are supporting the format. But if the key to acceptance is content, the HD-DVD supporting movie studios represent more than 40 percent of Hollywood’s films. The Blu-ray backing entertainment companies are, Sony, 20^th Century Fox (which includes MGM) and Disney-Buena Vista, which amounts to about 35 percent. It’s close enough at the moment to say that we will most likely have both in the end.

Another indication that we will have both formats, at least for a while, is the fact that some companies like Thomson Electronics have indicated they intend to support both.

Media production / Production costs

The advantage in this case goes to HD-DVD because of the similarity to the current DVD manufacturing processes. This makes it less expensive to adapt the current production lines for producing HD-DVD’s. Memory Tech has created a new production line, which can be adapted to produce HD-DVDs in 5 minutes, and this manufacturing line can make 1 HD-DVD in 2.8 seconds. Since the production of a HD-DVD media requires a higher technical precision and therefore a better quality control, we can also await a better quality of conventional DVD medias.

The production of Blu-ray disc will involve more cost, because the companies will have to add equipment for the cover layer portion and it’s not that easy to adapt current lines for BD production. Further, it will take about 4-5 seconds to manufacture one media. This is just slightly slower than for a HD-DVD, but multiply this difference by the millions of discs that will be produced and you can see that this becomes an important issue in the cost per unit.

Of course, one could argue that with future innovations it might be possible to reduce the production time for a single disc Blu-ray disc to match HD-DVD efficiencies. But there is still the burden for re-tooling and it seems that it is not possible to produce DVDs on BD adapted production lines. So the companies must have 2 different production lines when they want to produce DVD and BD discs.

Storage capacity 

This is a definite plus for Blu-ray. The single and dual layer discs will offer much more capacity than HD-DVDs. Some developments regarding multi-layer BD discs show us that a Blu-ray disc can hold 8 layers. This offers a potential to store up to 200 GB of data, considerably greater than the theoretical 60GB of a possible double-sided, dual layer, HD-DVD. Of course, who knows if the end user will see such medias in the near future, but we know that it is technically possible.

On the other hand, we have to add that the high storage capacities that BD offers are not really a must for recording high definition content. This is because of new compression technologies, such as MPEG-4 AVC, which makes it possible to produce high quality content at lower bit rates without a visible loss of quality. With this advanced codec technology, it is possible to store 8 hours of high definition video on a 30GB HD-DVD. For the moment, this is enough to store the movie and all the extras.

Transfer Rate/Recording Speed

Here is another advantage for Blu-ray resulting from the NA/Wavelength combination. Since this combination also affects the data density, Blu-ray requires a much lower rotation speed of the disc to reach the specified transfer rate of 36Mbps. A constant rotation speed of 10.000 RPM, which is the current upper limit for optical drives, will result in 12x BD but only 9x HD-DVD. This means that a HD-DVD must rotate faster to reach the same transfer rates.

Something similar applies to the BD-ROM format, compared to current DVDs, Blu-ray provides a five times higher data rate while only doubling the rotation speed of current DVD-ROMs.

Durability

If TDK’s hard coat can live up to it’s marketing claims, discs provided with the 0.1 mm coating will be even more resistant against damage then current DVDs. The coating is highly scratch resistant and fingerprints can be wiped off to a point where the disc can be read perfectly. This feature will help Blu-ray take an advantage. The negative point is that the coating makes the BD more expensive.

With the integral 0.6 mm protective layer, special coating on the HD-DVD disc is unnecessary. This seems more than logical, because we all know how to handle DVDs. On the other hand, it would be a nice improvement for HD-DVD.

Backward compatibility

Devices that are fully compatible with current red laser technologies (CD and DVD) will be available for both of the formats. NEC has come forward in the press recently with a half height, hybrid drive that is able to handle all three formats (HD-DVD, DVD and CD). Philips presented a drive capable of reading/writing CD/DVD and Blu-ray at this years CES show in Las Vegas.

Unfortunately, there is a problem with Blu-ray and HD-DVD compatibility. With the currently presented devices, we will not be able to playback content on HD-DVD media with a Blu-ray device and vice versa, be it data or games. But this will become essential for both of the formats, at least until one becomes dominant.

We have not seen any evidence of such a technology at the time of this writing. But let’s be optimistic, when there are ways to make devices DVD and CD compatible, then surely it is also possible that we will see drives which can handle all of these formats in the future. Of course, this will happen only on the condition that there is a will to produce such devices.

Hybrid Discs

Here we can find an advantage for Blu-ray, resulting from the new structure of the disc. Since the recording layer for Blu-ray data is only 0.1 mm away from the surface of the disc there is enough space below to integrate a complete 8.5 GB DVD DL disc. JVC has already managed to develop such a single-sided disc by using a for red laser transparent Blu-ray layer.

DVD9/HD-DVD is also possible, but not on a single-sided disc. Cinram, one of the HD-DVD backing companies has developed a hybrid disk with two sides. The first consists of a dual-layer DVD that can store up to 8.4GB of data, while the other side is a HD-DVD capable of storing up to 15GB. Memory-Tech and Toshiba has also developed single-sided hybrid discs that contain a 15GB HD-DVD layer and a 4.7GB DVD layer.