25-06-2012, 12:11 PM
Blu-ray Disc
Blu-ray Disc.pdf (Size: 378.74 KB / Downloads: 64)
Blu-ray Disc (official abbreviation BD) is an optical disc
storage medium designed to supersede the DVD format.
The plastic disc is 120 mm in diameter and 1.2 mm thick,
the same size as DVDs and CDs. Blu-ray Discs contain 25
GB per layer, with dual layer discs (50 GB) being the
norm for feature-length video discs. Triple layer discs
(100 GB) and quadruple layers (128 GB) are available for
BD-XL re-writer drives.[2]
The major application of Blu-ray Discs is as a medium for
video material such as feature films. Besides the hardware
specifications, Blu-ray Disc is associated with a set of
multimedia formats. Generally these formats allow for the
video and audio to be stored with greater definition than
on DVD.
History
Origins
The information density of the DVD format was limited
by the wavelength of the laser diodes used. Following
protracted development, blue laser diodes operating
around 400 nanometers became available on a production
basis. Sony started two projects in collaboration with
Philips[7] applying the new diodes: UDO (Ultra Density
Optical),[8] and DVR Blue (together with Pioneer),[9] a
format of rewritable discs that would eventually become
Blu-ray Disc (more specifically, BD-RE). The core
technologies of the formats are similar.
Competition from HD DVD
The DVD Forum, chaired by Toshiba, was split over whether to develop the more expensive blue laser
technology. In March 2002, the forum approved a proposal endorsed by Warner Bros. and other motion
picture studios that involved compressing HD content onto dual-layer standard DVD-9 discs.[31][32] In spite
of this decision, however, the DVD Forum's Steering Committee announced in April that it was pursuing its
own blue-laser high-definition video solution. In August, Toshiba and NEC announced their competing
standard, Advanced Optical Disc.[33] It was finally adopted by the DVD Forum and renamed HD DVD the
next year,[34] after being voted down twice by DVD Forum members who were also Blu-ray Disc
Association members—a situation that drew preliminary investigations by the U.S. Department of Justice.
[35][36]
Future prospects and market trends
According to Adams Media Research, high-definition software sales in the US were slower in the first two
years than DVD software sales.[47] 16.3 million DVD software units were sold in the first two years
(1997–98) compared to 8.3 million high-definition software units (2006–07).[47][48] One reason given for
this difference was the smaller marketplace (26.5 million HDTVs in 2007 compared to 100 million SDTVs in
1998).[47][48] Former HD DVD supporter Microsoft has stated that they are not planning to make a Blu-ray
Disc drive for the Xbox 360.[49]
Blu-ray Disc began making serious strides as soon as the format war ended. Nielsen VideoScan sales
numbers showed that with some titles, such as 20th Century Fox's Hitman, up to 14% of total disc sales were
from Blu-ray, although the average for the first half of the year was around 5%. Shortly after the format war
ended, a study by The NPD Group found that awareness of Blu-ray Disc had reached 60% of U.S.
households. In December 2008, the Blu-ray Disc of The Dark Knight sold 600,000 copies on the first day of
its launch in the United States, Canada, and the United Kingdom.[50] A week after launch, The Dark Knight
BD had sold over 1.7 million copies worldwide, making it the first Blu-ray Disc title to sell over a million
copies in the first week of release.
Blu-ray Disc.pdf (Size: 378.74 KB / Downloads: 64)
Blu-ray Disc (official abbreviation BD) is an optical disc
storage medium designed to supersede the DVD format.
The plastic disc is 120 mm in diameter and 1.2 mm thick,
the same size as DVDs and CDs. Blu-ray Discs contain 25
GB per layer, with dual layer discs (50 GB) being the
norm for feature-length video discs. Triple layer discs
(100 GB) and quadruple layers (128 GB) are available for
BD-XL re-writer drives.[2]
The major application of Blu-ray Discs is as a medium for
video material such as feature films. Besides the hardware
specifications, Blu-ray Disc is associated with a set of
multimedia formats. Generally these formats allow for the
video and audio to be stored with greater definition than
on DVD.
History
Origins
The information density of the DVD format was limited
by the wavelength of the laser diodes used. Following
protracted development, blue laser diodes operating
around 400 nanometers became available on a production
basis. Sony started two projects in collaboration with
Philips[7] applying the new diodes: UDO (Ultra Density
Optical),[8] and DVR Blue (together with Pioneer),[9] a
format of rewritable discs that would eventually become
Blu-ray Disc (more specifically, BD-RE). The core
technologies of the formats are similar.
Competition from HD DVD
The DVD Forum, chaired by Toshiba, was split over whether to develop the more expensive blue laser
technology. In March 2002, the forum approved a proposal endorsed by Warner Bros. and other motion
picture studios that involved compressing HD content onto dual-layer standard DVD-9 discs.[31][32] In spite
of this decision, however, the DVD Forum's Steering Committee announced in April that it was pursuing its
own blue-laser high-definition video solution. In August, Toshiba and NEC announced their competing
standard, Advanced Optical Disc.[33] It was finally adopted by the DVD Forum and renamed HD DVD the
next year,[34] after being voted down twice by DVD Forum members who were also Blu-ray Disc
Association members—a situation that drew preliminary investigations by the U.S. Department of Justice.
[35][36]
Future prospects and market trends
According to Adams Media Research, high-definition software sales in the US were slower in the first two
years than DVD software sales.[47] 16.3 million DVD software units were sold in the first two years
(1997–98) compared to 8.3 million high-definition software units (2006–07).[47][48] One reason given for
this difference was the smaller marketplace (26.5 million HDTVs in 2007 compared to 100 million SDTVs in
1998).[47][48] Former HD DVD supporter Microsoft has stated that they are not planning to make a Blu-ray
Disc drive for the Xbox 360.[49]
Blu-ray Disc began making serious strides as soon as the format war ended. Nielsen VideoScan sales
numbers showed that with some titles, such as 20th Century Fox's Hitman, up to 14% of total disc sales were
from Blu-ray, although the average for the first half of the year was around 5%. Shortly after the format war
ended, a study by The NPD Group found that awareness of Blu-ray Disc had reached 60% of U.S.
households. In December 2008, the Blu-ray Disc of The Dark Knight sold 600,000 copies on the first day of
its launch in the United States, Canada, and the United Kingdom.[50] A week after launch, The Dark Knight
BD had sold over 1.7 million copies worldwide, making it the first Blu-ray Disc title to sell over a million
copies in the first week of release.