youssefelhnaoui
11-27-2007, 02:08 PM
Blu-ray Disc
http://cache.kotaku.com/images/2006/04/bluray.jpg
Blu-ray, also known as Blu-ray Disc (BD), is the name of a next-generation optical disc format jointly developed by the Blu-ray Disc Association (BDA), a group of the world's leading consumer electronics, personal computer and media manufacturers (including Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson). The format was developed to enable recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. The format offers more than five times the storage capacity of traditional DVDs and can hold up to 25GB on a single-layer disc and 50GB on a dual-layer disc. This extra capacity combined with the use of advanced video and audio codecs will offer consumers an unprecedented HD experience.
http://content.answers.com/main/content/wp/en/1/14/Blu-ray_Disc.svg.png
While current optical disc technologies such as DVD, DVD±R, DVD±RW, and DVD-RAM rely on a red laser to read and write data, the new format uses a blue-violet laser instead, hence the name Blu-ray. Despite the different type of lasers used, Blu-ray products can easily be made backwards compatible with CDs and DVDs through the use of a BD/DVD/CD compatible optical pickup unit. The benefit of using a blue-violet laser (405nm) is that it has a shorter wavelength than a red laser (650nm), which makes it possible to focus the laser spot with even greater precision. This allows data to be packed more tightly and stored in less space, so it's possible to fit more data on the disc even though it's the same size as a CD/DVD. This together with the change of numerical aperture to 0.85 is what enables Blu-ray Discs to hold 25GB/50GB.
HD DVD
http://cache.gizmodo.com/assets/resources/2007/05/hd_dvd_bluray_copies.jpg
http://www.blorge.com/images/567452a793a8_61D5/hd_dvd.jpg
(High Definition DVD) A high-capacity optical disk that holds four hours of high-definition video on a single-sided, single-layer 15GB disk. Sanctioned by the DVD Forum in 2003 and based on the Advanced Optical Disc (AOD) technology from Toshiba and NEC, HD DVD uses a blue-violet laser that reads pits half the size of a DVD on tracks that are packed tighter together. HD DVD supports the more advanced H.264 and VC-1 video encoding algorithms (codecs) as well as MPEG-2, which is used for DVD. See H.264 and VC-1.
A distinct advantage of HD DVD for the media manufacturer is that HD DVDs are an evolution of the standard DVD. Unlike the competing Blu-ray format, which requires new machinery to make the disks, traditional DVD stamping machines need only minor modifications to make HD DVDs.
The first HD DVD drives were introduced in the U.S. in 2006, and Microsoft offered an HD DVD drive option for its Xbox 360 video game console in that same year.
HD DVD-ROM, HD DVD-R and HD DVD-RW
Like CD, DVD and Blu-ray media, there are read-only, write-once and rewritable options. Used for HD movies, HD DVD-ROMs are pre-recorded discs that cannot be changed. HD DVD-R media can be "burned" once by the user, and HD DVD-RW disks can be rewritten over and over.
HD DVD Hybrids
Hybrid HD DVD disks are read-only media that store a movie in both HD DVD and standard DVD. There are two types: combination hybrids use both sides, each side containing a different format, and Twin Format hybrids use only one side of a dual or triple layer disk, storing the different formats in separate layers.
In late 2006, Warner Home Video announced a hybrid disc that holds HD DVD and Blu-ray on one side and DVD on the other. In 2007, LG introduced the Super Blu, the first dual-format player, supporting both HD DVD and Blu-ray media. It is expected that between dual-format media and dual-format players, the problem of competing HD DVD and Blu-ray formats will be solved. Stay tuned! See high-def DVD formats, Blu-Ray, DVD and DTV. See also HD DVR.
FULL-SIZE HD DVD DISK (120 mm) CAPACITIES
SINGLE SIDED DOUBLE SIDED
HD HD
Layers Storage Hours Storage Hours
Single 15GB 4
Dual 30GB 8 38.5GB 8HD/4SD
Triple 45GB 12
45GB 8HD/8SD
http://cache.kotaku.com/images/2006/04/bluray.jpg
Blu-ray, also known as Blu-ray Disc (BD), is the name of a next-generation optical disc format jointly developed by the Blu-ray Disc Association (BDA), a group of the world's leading consumer electronics, personal computer and media manufacturers (including Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson). The format was developed to enable recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. The format offers more than five times the storage capacity of traditional DVDs and can hold up to 25GB on a single-layer disc and 50GB on a dual-layer disc. This extra capacity combined with the use of advanced video and audio codecs will offer consumers an unprecedented HD experience.
http://content.answers.com/main/content/wp/en/1/14/Blu-ray_Disc.svg.png
While current optical disc technologies such as DVD, DVD±R, DVD±RW, and DVD-RAM rely on a red laser to read and write data, the new format uses a blue-violet laser instead, hence the name Blu-ray. Despite the different type of lasers used, Blu-ray products can easily be made backwards compatible with CDs and DVDs through the use of a BD/DVD/CD compatible optical pickup unit. The benefit of using a blue-violet laser (405nm) is that it has a shorter wavelength than a red laser (650nm), which makes it possible to focus the laser spot with even greater precision. This allows data to be packed more tightly and stored in less space, so it's possible to fit more data on the disc even though it's the same size as a CD/DVD. This together with the change of numerical aperture to 0.85 is what enables Blu-ray Discs to hold 25GB/50GB.
HD DVD
http://cache.gizmodo.com/assets/resources/2007/05/hd_dvd_bluray_copies.jpg
http://www.blorge.com/images/567452a793a8_61D5/hd_dvd.jpg
(High Definition DVD) A high-capacity optical disk that holds four hours of high-definition video on a single-sided, single-layer 15GB disk. Sanctioned by the DVD Forum in 2003 and based on the Advanced Optical Disc (AOD) technology from Toshiba and NEC, HD DVD uses a blue-violet laser that reads pits half the size of a DVD on tracks that are packed tighter together. HD DVD supports the more advanced H.264 and VC-1 video encoding algorithms (codecs) as well as MPEG-2, which is used for DVD. See H.264 and VC-1.
A distinct advantage of HD DVD for the media manufacturer is that HD DVDs are an evolution of the standard DVD. Unlike the competing Blu-ray format, which requires new machinery to make the disks, traditional DVD stamping machines need only minor modifications to make HD DVDs.
The first HD DVD drives were introduced in the U.S. in 2006, and Microsoft offered an HD DVD drive option for its Xbox 360 video game console in that same year.
HD DVD-ROM, HD DVD-R and HD DVD-RW
Like CD, DVD and Blu-ray media, there are read-only, write-once and rewritable options. Used for HD movies, HD DVD-ROMs are pre-recorded discs that cannot be changed. HD DVD-R media can be "burned" once by the user, and HD DVD-RW disks can be rewritten over and over.
HD DVD Hybrids
Hybrid HD DVD disks are read-only media that store a movie in both HD DVD and standard DVD. There are two types: combination hybrids use both sides, each side containing a different format, and Twin Format hybrids use only one side of a dual or triple layer disk, storing the different formats in separate layers.
In late 2006, Warner Home Video announced a hybrid disc that holds HD DVD and Blu-ray on one side and DVD on the other. In 2007, LG introduced the Super Blu, the first dual-format player, supporting both HD DVD and Blu-ray media. It is expected that between dual-format media and dual-format players, the problem of competing HD DVD and Blu-ray formats will be solved. Stay tuned! See high-def DVD formats, Blu-Ray, DVD and DTV. See also HD DVR.
FULL-SIZE HD DVD DISK (120 mm) CAPACITIES
SINGLE SIDED DOUBLE SIDED
HD HD
Layers Storage Hours Storage Hours
Single 15GB 4
Dual 30GB 8 38.5GB 8HD/4SD
Triple 45GB 12
45GB 8HD/8SD