Blu-Ray and HD DVD – Which is DVD’s successor?
Both figures compete with one another first of all for the consideration of film studios. They are the ones who will resolve the dispute about whether which one will “be or not be” in the electronic consumables market.
Blu-ray was prepared by the Blu-Ray Disc Association. Already in 2002 the companies Sony and Phillips, the biggest supporters, and also beneficiaries of research and development, presented a new Blu-ray format based on blue laser technology. The whole project for this medium was created from the beginning other than in the case of the competing HD DVD, which is a modification of the DVD format. The name Blu-ray comes from the blue beam. The omission of the “e” is done on purpose to enable the registration of the name as a trademark.
The Blu-ray family consists of:
• BD-Rom, which is a type of disc for reading only, used for software, games and film distribution.
• BD-R, which is a type of disc for recording, used to store HDTV images and data.
• BD-RW, which is a type of disc for multiple recording, used to store HDTV images and data.
The competitive standard HD-DVD (High Definition DVD) was created by Toshiba, NEC and Memory-Tech, the companies which are affiliated with the organisation AOSRA. HD DVD, like Blu-ray, uses blue laser technology, and as is the case with the first format, thanks to this it has a greater capacity. HD DVD has more in common with DVD, thanks to which it is not necessary to invest in new production lines, merely to modify current pre-existing lines which are used to press DVD mediums.
The HD DVD family consists of:
• HD DVD-Rom, which is a type of disc for reading only
• 3x DVD Rom
• Mini HD DVD (8cm), the capacity of a single-layered disc is 4.7GB, however for a
double-layer disc 9.4GB;
• HD DVD-R, which is a type of disc for recording, with a capacity of 15GB per side, in
total 30GB;
• HD DVD-RW, which is a type of disc for multiple recording, with a capacity of 20GB
per side, in total 40GB;
Below is a comparison of the technical possibilities, but only as regards pressed discs (for reading), because the parameters of the R/RW versions are being developed very quickly.
|
|
DVD
|
Blu-ray
|
HD DVD
|
|
Type of disc
|
DVD-Rom
|
Blu-ray
|
HD DVD Rom
|
|
Size of disc
|
120mm
|
120mm
|
120mm
|
|
Disc structure
|
0.6mm x2 surfaces
|
0.85mm x2 surfaces
|
0.65mm x2 surfaces
|
|
Number of layers
|
1 or 2
|
1 or 2
|
1 or 2
|
|
Capacity
|
4.7 GB/8.5 GB
|
25GB/50GB
|
15GB/30GB/60GB
|
|
Wavelength of laser
|
650nm (red laser)
|
405nm (blue laser)
|
405nm (blue laser)
|
|
Compression technology
|
MPEG-2
|
MPEG-4 AVC / VC1 / MPEG-2
|
MPEG-4 AVC / VC1 / MPEG-2
|
|
Pressing time per unit
|
1.7 – 2.5 sec
|
3.8 sec
|
2.8 sec
|
|
Track width
|
0.74μm
|
0.32μm
|
0.40μm
|
The technical data, as we can see, is different as regards important issues of capacity and leading track, on which the possibility to further compress data depends. However, in connection with the battle for influence which DVD previously had, the parameters will not decide which wins, but the money and marketing activities.
Setting aside market battles between companies and multimedia corporations, it is worth paying attention to the fact: what advantages do new formats give the user. They certainly guarantee a better quality of playback but also recording for the new high definition standard (HD). The wavelength of the laser for both formats ensures a higher level of precision, and as a result a larger amount of data on the medium.
The interesting advantage is simultaneous reading and recording of data, which is enabled by a mechanism which guides this laser. However, the indisputable and most important features are the enormous possibilities for disc capacity, which refer to the DVD potential and advanced technologies of contents.
The situation in the market can be changed by other players, but is this for sure? Difficult to say. However, the organisation HVD Alliance joined the game with the format Holographic Versatile Disc (HVD) and D Data, with a multi-layer digital medium (DMD-Digital Multilayer Disc). In this situation we will carefully observe and follow the activities of giants in the optical medium market.