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HIGH DEFINITION OPTICAL DISC TECHNOLOGY
Current Media Format
CD’s
Consist of pits and lands stamped out in a spiral pattern on the disc.
A laser then reads the pits and lands.
The change from a pit to a land or a land to a pit indicates a one while no change indicates a zero.
Current Media Format (Cont.)
CD-RW’s
Consist of a metal phase change alloy which when heated can be to change to reflectivity
CD-R’s
Consist of a dye that is applied to the disc.
When a writing laser is shined it changes the reflectivity.
Current Media Format (Cont.)
DVD’s
Also contain pits and lands.
Are more highly compact than a CD.
Less Overhead, More Space
Multi-Layer Storage is possible.
DVDs
Multi-Layer Storage
To increase the storage capacity even more, a DVD can have up to four layers
When a disc is made with two layers, the pits have to be a little longer, on both layers, than when a single layer is used.
This helps to avoid interference between the layers, which would cause errors when the disc is played.
High Definition
To better understand the need for media formats with greater storage lets briefly describe what High Definition is.
Your regular TV signal has about 480 pixel lines, but HD has about 1280 pixel lines that go across your TV
Because of this difference the space required for HD is about 5 times greater than standard video.
Currently a standard definition movie takes up almost an entire DVD so we need something that’s almost 5 times that.
Blu-ray Technology
Name
Derived from the blue-violet laser used to read and write data.
Developed by the Blu-ray Disc Association founded by Sony, Panasonic, Pioneer, Philips, Thomson, LG, Hitachi, Sharp and Samsung now has more than 180 members.
Blu-Ray Technology
Because Blu-ray uses a blue laser(405 nanometers produced by GaN diodes directly) instead of a red laser(650 nanometers) this allows the data tracks on the disc to be very compact.
This allows for more than twice as small pits as on a DVD.
Blu-ray Technology (Cont.)
Because of the greatly compact data Blu-ray can hold almost 5 times more data than a single layer DVD. Close to 25 GB!
Just like a DVD Blu-ray can also be recorded in Dual-Layer format. This allows the disk to hold up to 50 GB!!
Because the polycarbonate layer of the Blu-ray disc is so much larger than a DVD because the recording layer is so much smaller it can have even more than two layers.
Blu-ray Technology (Cont.)
Blu-ray uses a combination of two lenses to greatly shrink the laser to read the data.
This also allows for higher data rate transfer close to 36 mbps.
It could record 25 GB of data in an hour an a half.
Blu-ray Technology (Cont.)
The Blu-ray disc overcomes DVD-reading issues by placing the data on top of a 1.1-mm-thick polycarbonate layer
Data on top prevents birefringence
With the recording layer sitting closer to the objective lens of the reading mechanism, the problem of disc tilt is virtually eliminated.
Blu-ray Technology (Cont.)
Design of the Blu-ray discs saves on manufacturing costs. Traditional DVDs are built by injection molding the two 0.6-mm discs between which the recording layer is sandwiched. The process must be done very carefully to prevent birefringence.
Blu-ray discs only do the injection-molding process on a single 1.1-mm disc, which reduces cost.
Blu-ray Technology
BD-ROM (read-only) - for pre-recorded content
BD-R (recordable) - for PC data storage
BD-RW (rewritable) - for PC data storage
BD-RE (rewritable) - for HDTV recording
Blu-ray Integration
Blu-ray discs are able to record HD without any signal loss.
Single layer up to 2 hours of HD video
Dual layer up to 4.5 hours of HD video
Blu-ray Integration Cont.
Security
Blu-ray discs are better armed than current DVDs. They come equipped with a secure encryption system -- a unique ID that protects against video piracy and copyright infringement.
HD DVD Technology
Name
Comes from the term High Definition
Envisioned to be the successor to the standard DVD format
Developed by Toshiba and NEC
HD DVD Technology
Data Capacity
HD DVD uses close to the same blue laser that the Blu-ray disc does. It is also 405 nanometers wide.
Thus allows for data to be greatly compressed.
HD DVD Technology (Cont.)
Data Capacity Cont.
Single Layer Disc
15 GB
Dual Layer Disc
30 GB
HD DVD Technology
HD DVD (read-only) - for pre-recorded content
HD DVD-R (recordable) - for PC data storage
HD DVD-RAM (rewritable) - for HDTV recording and PC Storage
HD DVD Integration
Compatibility
Because a lot of home-users don’t yet have a high definition Television the makers of the HD DVD disc made it backwards compatible by using the twin format scheme.
HD DVD Integration
But what about dual layer??
In order to accommodate for the needs of the storage capacity of the dual layer format the makers designed the combination format.
HD DVD Integration
Security
Uses the same security feature as Blu-ray.
Both Blu-ray and HD DVD makers said would be extremely hard to pirate with this security feature.
Eight days after HD DVD discs hit the market a hacker called muslix64 reportedly cracked the security feature.
vs
Both formats use blue lasers rather than red.
Both have the same options for video and audio compression.
Blu-ray offers significantly more storage space -- 50 GB on a dual-layer disc versus HD-DVD's 30 GB.
The DVD Forum, which creates DVD standards, has approved HD-DVD and has not approved Blu-ray.
HD-DVD is less expensive than Blu-ray.
HD-DVDs can be produced on existing equipment, and Blu-ray discs can't.
HD-DVD players were selling for $499 (Toshiba HD-A1) to $799 (HD-XA1), and Blu-ray players were selling for around $1,000 (Samsung DB-P1000).
HD-DVD players hit the market on April 18, 2006, two months before the first Blu-ray player hit the U.S. market in June, 2006.
vs
Supporters of HD-DVD included Toshiba, NEC, Sanyo, and Microsoft, in addition to New Line Cinema, Paramount, Universal, Time-Warner were the official approval of the DVD Forum.
Supporters for Blu-Ray includes PC makers Apple, Dell, Hewlett-Packard, and Sony, and electronics giants Hitachi, LG, Mitsubishi Electric, Matsushita/Panasonic, Pioneer, Philips, Samsung, Sharp, TDK, and Thomson. Add to this the support by movie studios such as Columbia TriStar, Sony Pictures and MGM (all three owned by Sony), 20th Century Fox, Lions Gate Entertainment, and Disney, as well as video game makers Electronic Arts and Vivendi Universal Games, and the bastion of support for Blu-Ray looks formidable indeed
WAR!!
Blu-ray and HD-DVD had gone to war, and companies began to side with one format or the other. A few movie studios hedged their bets and produced content for both formats. But that wasn't very efficient or cost-effective.
It was hard to tell which media format will win this format war.
It all depended on which format consumers can get more cheaply, more quickly, with more movies available for it. Blu-Ray is technologically superior