Blu-ray Disc

Un article de Vev.

Modèle:Pp-dispute Modèle:Infobox media

Blu-ray Disc is a high-density optical disc format for the storage of digital information, including high-definition video.

Overview

The name Blu-ray Disc is derived from the blue-violet laser used to read and write this type of disc. Because of its shorter wavelength (405 nm), substantially more data can be stored on a Blu-ray Disc than on the DVD format, which uses a red (650 nm) laser. A single layer Blu-ray Disc can store 25 gigabytes (GB), over five times the size of a single layer DVD at 4.7 GB. A dual layer Blu-ray Disc can store 50 GB, almost six times the size of a dual layer DVD at 8.5 GB.

Blu-ray was developed by the Blu-ray Disc Association, a group of leading companies representing consumer electronics, computer hardware, and motion picture production. The standard is covered by several patents belonging to different companies. As of March 2007, a joint licensing agreement for all the relevant patents has not yet been finalized.<ref>{{cite web www.cdfreaks.com/news/Significant-progress-made-toward-creation-of-joint-Blu-ray-Disc-patent-license-Press-Release.html//www.cdfreaks.com/news/Significant-progress-made-toward-creation-of-joint-Blu-ray-Disc-patent-license-Press-Release.html |title = Significant progress made toward creation of joint Blu-ray Disc™ patent license (Press Release) |accessdate = 2007-10-17 |author = Seán Byrne |date= 2007-02-23 |work = cdrfreaks.com }}</ref>

www.blu-ray.com/movies/movies.php?show=nowavailable | title=Total available United States releases }}</ref> titles have been released on Blu-ray Disc in the United States (32 of those titles have since been discontinued). As of October 9 2007, 179 titles have been released in Japan, with 55 titles planned for release.<ref> Japanese BD/HD DVD releases

.//www.blu-ray.com/movies/movies.php?show=nowavailable | title=Total available United States releases }}</ref> titles have been released on Blu-ray Disc in the United States (32 of those titles have since been discontinued). As of October 9 2007, 179 titles have been released in Japan, with 55 titles planned for release.<ref> Japanese BD/HD DVD releases

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The Blu-ray standard is currently in a format war with its rival HD DVD, to determine which (if either) of the two formats will become the leading carrier for high-definition content to consumers.

History

Modèle:Optical disc authoring

online.wsj.com/article/SB891992681208651500.html?mod=googlewsj |title= In HDTV Age, Successor to VCR Still Seems to Be a Long Way Off |accessdate=2007-10-18 |author=Evan Ramstad |date=1998-04-08 |work=online.wsj.com}}</ref> However, it was well known that using lasers with shorter wavelengths would enable optical storage with higher density. When Shuji Nakamura invented practical blue laser diodes, it was a sensation, although a lengthy patent lawsuit delayed commercial introduction.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.pcworld.com/article/id,103862-page,1/article.html</ref>//online.wsj.com/article/SB891992681208651500.html?mod=googlewsj |title= In HDTV Age, Successor to VCR Still Seems to Be a Long Way Off |accessdate=2007-10-18 |author=Evan Ramstad |date=1998-04-08 |work=online.wsj.com}}</ref> However, it was well known that using lasers with shorter wavelengths would enable optical storage with higher density. When Shuji Nakamura invented practical blue laser diodes, it was a sensation, although a lengthy patent lawsuit delayed commercial introduction.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.pcworld.com/article/id,103862-page,1/article.html</ref>

Origins

www.planetanalog.com/features/OEG20010615S0046 |title=Blue laser bolsters DTV storage, features |accessdate=2007-10-19 |author=S.B. Luitjens |date=2001-06-15 |work=planetanalog.com |publisher=}}</ref> The core technologies of the formats are essentially similar.//www.planetanalog.com/features/OEG20010615S0046 |title=Blue laser bolsters DTV storage, features |accessdate=2007-10-19 |author=S.B. Luitjens |date=2001-06-15 |work=planetanalog.com |publisher=}}</ref> The core technologies of the formats are essentially similar.

The first DVR Blue prototypes were unveiled at the CEATEC exhibition in October 2000.<ref>{{cite web www.cdfreaks.com/news/Significant-progress-made-toward-creation-of-joint-Blu-ray-Disc-patent-license-Press-Release.html//www.pcworld.com/article/id,105534-page,1/article.html |title = Sony Shows 'DVR-Blue' Prototype |accessdate = 2007-10-17 |date= 2000-10-11 |work = cdrinfo.com }}</ref> Because the Blu-ray Disc standard places the data recording layer close to the surface of the disc, early discs were susceptible to contamination and scratches and had to be enclosed in plastic cartridges for protection. In February 2002, the project was officially announced as Blu-ray,<ref> {{cite web www.cdfreaks.com/news/Significant-progress-made-toward-creation-of-joint-Blu-ray-Disc-patent-license-Press-Release.html//www.newscientist.com/article/dn1952.html |title = Replacement for DVD unveiled |accessdate = 2007-10-17 |author = Barry Fox |date= 2002-02-19 |work = newscientist.com }}</ref> and the Blu-ray Disc Association was founded by the nine initial members.

www.digit-life.com/articles2/blu-ray/ |title=SONY BDZ-S77 Recorder Review |accessdate=2007-10-19 |author=Maxim Liadov |date= |work=digit-life.com}}</ref> However, there was no standard for pre-recorded video (BD-ROM) and no movies were released for this player. The Blu-ray standard was still years away, since a new and secure DRM system was needed before Hollywood studios would accept it. Nobody wanted to repeat the failure of the Content Scramble System for DVDs.//www.digit-life.com/articles2/blu-ray/ |title=SONY BDZ-S77 Recorder Review |accessdate=2007-10-19 |author=Maxim Liadov |date= |work=digit-life.com}}</ref> However, there was no standard for pre-recorded video (BD-ROM) and no movies were released for this player. The Blu-ray standard was still years away, since a new and secure DRM system was needed before Hollywood studios would accept it. Nobody wanted to repeat the failure of the Content Scramble System for DVDs.

Competition from HD DVD

news.bbc.co.uk/2/hi/entertainment/1829241.stm |title=Next Generation DVD Born |accessdate=2007-11-4 |date=2002-02-21 |work=bbc.co.uk}}</ref> In March 2002, the forum voted to approve a proposal endorsed by Warner Bros. and other motion picture studios that involved compressing HD content onto dual-layer DVD-9 discs.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.eetimes.com/story/OEG20020301S0091</ref><ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.eetimes.com/story/OEG20011212S0060</ref> However, in spite of this decision, the DVD Forum's Steering Committee announced in April that it was pursuing its own blue-laser high-definition solution.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.emedialive.com/Articles/ReadArticle.aspx?ArticleID=5266&PageNum=2</ref> In August, Toshiba and NEC announced their competing standard Advanced Optical Disc.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.pcworld.com/article/id,104570-page,1/article.html</ref> It was finally adopted by the DVD forum and renamed HD DVD the next year,<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.theinquirer.net/en/inquirer/news/2003/11/28/dvd-forum-backs-toshiba-nec-format</ref> after being voted down twice by Blu-ray Disc Association members, prompting the U.S. Department of Justice to make preliminary investigations into the situation.<ref>Modèle:Cite webwww.foxnews.com/story/0,2933,189960,00.html//www.videobusiness.com/article/CA6458096.html</ref><ref>{{cite webwww.foxnews.com/story/0,2933,189960,00.html//www.videobusiness.com/article/CA6258560.html?q=DVD+Forum+Blu%2Dray|title=Lieberfarb lobs charges at Blu-ray}}</ref> Three new members had to be invited and the voting rules changed before the vote finally passed.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.my-esm.com/story/OEG20031114S0024</ref><ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.techweb.com/wire/story/TWB20031126S0005</ref>//news.bbc.co.uk/2/hi/entertainment/1829241.stm |title=Next Generation DVD Born |accessdate=2007-11-4 |date=2002-02-21 |work=bbc.co.uk}}</ref> In March 2002, the forum voted to approve a proposal endorsed by Warner Bros. and other motion picture studios that involved compressing HD content onto dual-layer DVD-9 discs.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.eetimes.com/story/OEG20020301S0091</ref><ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.eetimes.com/story/OEG20011212S0060</ref> However, in spite of this decision, the DVD Forum's Steering Committee announced in April that it was pursuing its own blue-laser high-definition solution.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.emedialive.com/Articles/ReadArticle.aspx?ArticleID=5266&PageNum=2</ref> In August, Toshiba and NEC announced their competing standard Advanced Optical Disc.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.pcworld.com/article/id,104570-page,1/article.html</ref> It was finally adopted by the DVD forum and renamed HD DVD the next year,<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.theinquirer.net/en/inquirer/news/2003/11/28/dvd-forum-backs-toshiba-nec-format</ref> after being voted down twice by Blu-ray Disc Association members, prompting the U.S. Department of Justice to make preliminary investigations into the situation.<ref>Modèle:Cite webwww.foxnews.com/story/0,2933,189960,00.html//www.videobusiness.com/article/CA6458096.html</ref><ref>{{cite webwww.foxnews.com/story/0,2933,189960,00.html//www.videobusiness.com/article/CA6258560.html?q=DVD+Forum+Blu%2Dray|title=Lieberfarb lobs charges at Blu-ray}}</ref> Three new members had to be invited and the voting rules changed before the vote finally passed.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.my-esm.com/story/OEG20031114S0024</ref><ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.techweb.com/wire/story/TWB20031126S0005</ref>

www.dvd-recordable.org/Article890-mode=thread-order0-threshold0.phtml |title=Sony to Launch 23GB Optical Disc |accessdate=2007-10-18 |author= |date=2003-10-21 |work=dvd-recordable.org }}</ref><ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.theregister.com/2003/12/02/sony ships bluray 23gb storage/</ref>//www.dvd-recordable.org/Article890-mode=thread-order0-threshold0.phtml |title=Sony to Launch 23GB Optical Disc |accessdate=2007-10-18 |author= |date=2003-10-21 |work=dvd-recordable.org }}</ref><ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.theregister.com/2003/12/02/sony ships bluray 23gb storage/</ref>

Attempts to avoid a format war

www.eetasia.com/ART_8800364355_499495_f3313299.HTM |title=Sides close to deal on HD disk format |accessdate=2007-10-19 |author=Junko Yoshida |date=2005-04-19 |work=eetasia.com |publisher=}}</ref> A much larger issue, though, was the physical formats of the discs themselves; the Blu-ray member companies did not want to risk losing billions of dollars in royalties as they had done with standard DVD.<ref name="stalemate">Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.internetnews.com/storage/article.php/3671091</ref> An agreement seemed close, but negotiations proceeded slowly.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.ft.com/cms/s/0/8e6df286-c670-11d9-b69b-00000e2511c8.html</ref>//www.eetasia.com/ART_8800364355_499495_f3313299.HTM |title=Sides close to deal on HD disk format |accessdate=2007-10-19 |author=Junko Yoshida |date=2005-04-19 |work=eetasia.com |publisher=}}</ref> A much larger issue, though, was the physical formats of the discs themselves; the Blu-ray member companies did not want to risk losing billions of dollars in royalties as they had done with standard DVD.<ref name="stalemate">Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.internetnews.com/storage/article.php/3671091</ref> An agreement seemed close, but negotiations proceeded slowly.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.ft.com/cms/s/0/8e6df286-c670-11d9-b69b-00000e2511c8.html</ref>

www.videobusiness.com/article/CA6281492.html|title=Micro-managed copies}}</ref> At the same time, Microsoft and Toshiba jointly announced that they would cooperate in developing high-definition DVD players.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.wired.com/techbiz/media/news/2005/06/68009</ref> In a top-level meeting in July, Microsoft's Bill Gates argued that the Blu-ray standard had to change to "work more smoothly with personal computers". The Blu-ray Disc Association's representatives defended the technology.<ref name="DaggersDrawn">Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.businessweek.com/magazine/content/05 42/b3955113.htm</ref>//www.videobusiness.com/article/CA6281492.html|title=Micro-managed copies}}</ref> At the same time, Microsoft and Toshiba jointly announced that they would cooperate in developing high-definition DVD players.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.wired.com/techbiz/media/news/2005/06/68009</ref> In a top-level meeting in July, Microsoft's Bill Gates argued that the Blu-ray standard had to change to "work more smoothly with personal computers". The Blu-ray Disc Association's representatives defended the technology.<ref name="DaggersDrawn">Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.businessweek.com/magazine/content/05 42/b3955113.htm</ref>

www.forbes.com/home/feeds/afx/2005/08/22/afx2188394.html |title=Sony, Toshiba fail to unify DVD format - report |accessdate=2007-10-19 |author= |date=2005-08-22 |work=forbes.com |publisher=}}</ref> Rumours surfaced that an "unnamed partner" had pressured Toshiba to stick with HD DVD—in spite of Blu-ray's strong support among Hollywood studios and some analysts saying that HD DVD's days were numbered—but these rumours were denied by the parties involved; instead, the same reasons of physical format incompatibility were cited.<ref name="stalemate"/><ref name="DaggersDrawn"/> At the end of September, Microsoft and Intel jointly announced their support for HD DVD.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.ecommercetimes.com/story/n6BNgaGjf2Pdrz/Microsoft-Intel-Back-Toshibas-HD-DVD.xhtml</ref>//www.forbes.com/home/feeds/afx/2005/08/22/afx2188394.html |title=Sony, Toshiba fail to unify DVD format - report |accessdate=2007-10-19 |author= |date=2005-08-22 |work=forbes.com |publisher=}}</ref> Rumours surfaced that an "unnamed partner" had pressured Toshiba to stick with HD DVD—in spite of Blu-ray's strong support among Hollywood studios and some analysts saying that HD DVD's days were numbered—but these rumours were denied by the parties involved; instead, the same reasons of physical format incompatibility were cited.<ref name="stalemate"/><ref name="DaggersDrawn"/> At the end of September, Microsoft and Intel jointly announced their support for HD DVD.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.ecommercetimes.com/story/n6BNgaGjf2Pdrz/Microsoft-Intel-Back-Toshibas-HD-DVD.xhtml</ref>

www.vnunet.com/vnunet/news/2144325/hp-calls-changes-blu-ray |title=HP calls for changes to Blu-ray |accessdate=2007-10-19 |author=Ken Young |date=2005-10-20 |work=vnunet.com}}</ref> In a research report, Gartner analysts Van Baker, Laura Behrens and Mike McGuire wrote that if HP's proposal was accepted, Blu-ray would become the winner of the format war.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.vnunet.com/vnunet/news/2144595/hp-blu-ray-move-spells-doom-hd</ref> However, the Blu-ray disc group did not accept HP's proposal.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.foxnews.com/story/0,2933,175904,00.html</ref>//www.vnunet.com/vnunet/news/2144325/hp-calls-changes-blu-ray |title=HP calls for changes to Blu-ray |accessdate=2007-10-19 |author=Ken Young |date=2005-10-20 |work=vnunet.com}}</ref> In a research report, Gartner analysts Van Baker, Laura Behrens and Mike McGuire wrote that if HP's proposal was accepted, Blu-ray would become the winner of the format war.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.vnunet.com/vnunet/news/2144595/hp-blu-ray-move-spells-doom-hd</ref> However, the Blu-ray disc group did not accept HP's proposal.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.foxnews.com/story/0,2933,175904,00.html</ref>

Blu-ray Disc format finalized and launched

The Blu-ray physical specifications were finished in 2004.<ref>{{cite web www.cdfreaks.com/news/Significant-progress-made-toward-creation-of-joint-Blu-ray-Disc-patent-license-Press-Release.html//www.pcworld.com/article/id,117242-page,1/article.html |title = New Blu-ray Details Emerge |accessyear = 2007-10-17 |author = Martyn Williams |date= 2004-08-05 |work = pcworld.com www.physorg.com/news2615.html |title=Exclusive TDK Durabis Coating Technology Makes Cartridge-Free, Ultra-Durable Blu-Ray Discs a Reality |accessdate=2007-10-18 |author= |date=2005-01-09 |work=physorg.com |publisher=}}</ref> The cartridges, no longer necessary, were scrapped.//www.physorg.com/news2615.html |title=Exclusive TDK Durabis Coating Technology Makes Cartridge-Free, Ultra-Durable Blu-Ray Discs a Reality |accessdate=2007-10-18 |author= |date=2005-01-09 |work=physorg.com |publisher=}}</ref> The cartridges, no longer necessary, were scrapped. The BD-ROM specifications were finalized in early 2006.<ref>{{cite web www.cdfreaks.com/news/Significant-progress-made-toward-creation-of-joint-Blu-ray-Disc-patent-license-Press-Release.html//www.theregister.co.uk/2006/01/06/blu-ray_spec_done/ |title = Blu-ray Disc developers complete specification |accessdate = 2007-10-17 |author = Tony Smith |date= 2006-01-06 |work = theregister.co.uk www.wired.com/entertainment/music/news/2004/07/64212 |title=Can Odd Alliance Beat Pirates? |accessdate=2007-10-19 |author=Katie Dean |date=2004-07-15 |work=wired.com}}</ref> had been developing the DRM platform that could be used to securely distribute movies to consumers. However, the final AACS standard was delayed,<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.pcworld.com/article/id,123924-page,1/article.html</ref> and then delayed again when an important member of the Blu-ray group voiced concerns.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.heise.de/english/newsticker/news/69559</ref> At the request of Toshiba, an interim standard was published which did not include some features, like managed copy.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.pcworld.com/article/id,124961-page,1/article.html</ref>//www.wired.com/entertainment/music/news/2004/07/64212 |title=Can Odd Alliance Beat Pirates? |accessdate=2007-10-19 |author=Katie Dean |date=2004-07-15 |work=wired.com}}</ref> had been developing the DRM platform that could be used to securely distribute movies to consumers. However, the final AACS standard was delayed,<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.pcworld.com/article/id,123924-page,1/article.html</ref> and then delayed again when an important member of the Blu-ray group voiced concerns.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.heise.de/english/newsticker/news/69559</ref> At the request of Toshiba, an interim standard was published which did not include some features, like managed copy.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.pcworld.com/article/id,124961-page,1/article.html</ref>

The first BD-ROM players were shipped in the middle of June 2006, though HD DVD players beat them in the race to the market by a few months.<ref>{{cite web www.foxnews.com/story/0,2933,189960,00.html//www.foxnews.com/story/0,2933,189960,00.html |title= Toshiba Starts Selling HD DVD Players in Japan |accessdate=2007-10-17 |author= |date= 2006-03-31 |work= foxnews.com }}</ref><ref>{{cite web www.foxnews.com/story/0,2933,189960,00.html//www.pcmag.com/article2/0,2704,1977327,00.asp |title= Samsung Ships the First Blu-Ray Player |accessdate=2007-10-17 |author= Dan Costa |date= 2006-06-15 |work= pcmag.com }}</ref>

bluray.highdefdigest.com/news/show/Warner/Disc_Announcements/Full_Specs_in_for_Warners_Sept_26_Lineup_Studio_to_Go_VC-1_for_Blu-ray/209 Full Specs in for Warner's Sept 26 Lineup; Studio to Go VC-1 for Blu-ray?], BLU-RAY NEWS, High-Def Digest, 30 August 2006</ref> The first movies using dual layer discs (50 GB) were introduced in October 2006.<ref> {{cite web//bluray.highdefdigest.com/news/show/Warner/Disc_Announcements/Full_Specs_in_for_Warners_Sept_26_Lineup_Studio_to_Go_VC-1_for_Blu-ray/209 Full Specs in for Warner's Sept 26 Lineup; Studio to Go VC-1 for Blu-ray?], BLU-RAY NEWS, High-Def Digest, 30 August 2006</ref> The first movies using dual layer discs (50 GB) were introduced in October 2006.<ref> {{cite web bluray.highdefdigest.com/click.html//bluray.highdefdigest.com/click.html | title = Click: Blu-ray Disc review | accessdate = 2007-09-15 | date= 2006-10-10 | last = Bracke | first = Peter M. | work = HighDefDigest.com }}</ref>

The first mass-market Blu-ray rewritable drive for the PC was the BWU-100A, released by Sony on July 18 2006. It recorded both single and dual layer BD-R as well as BD-RE discs and had a suggested retail price of US$699.

HD DVD had a head start in the high definition video market and Blu-ray sales were slow at first. The first Blu-ray player was perceived as expensive and buggy, and there were few titles available.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//reviews.cnet.com/video-players-and-recorders/samsung-bd-p1000/4505-6463 7-31799185.html</ref> This changed when PlayStation 3 launched, since every PS3 unit also functioned as a Blu-ray player. By February 2007, Blu-ray discs had outsold HD DVDs,<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.homemediamagazine.com/news/html/breaking article.cfm?article id=10323</ref> and during the first three quarters of 2007, BD discs outsold HD DVDs by about two to one.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.charleston.net/news/2007/sep/30/dvd formats blu ray hd square off17561/</ref>

Disc structure

Laser and optics

Like its rival format HD DVD, Blu-ray uses a "blue" (technically violet) laser operating at a wavelength of 405 nm to read and write data. Conventional DVDs and CDs use red and near infrared lasers at 650 nm and 780 nm respectively.

The blue-violet laser's shorter wavelength makes it possible to store more information on a 12 cm CD/DVD sized disc. The minimum "spot size" on which a laser can be focused is limited by diffraction, and depends on the wavelength of the light and the numerical aperture of the lens used to focus it. By decreasing the wavelength, increasing the numerical aperture from 0.60 to 0.85 and making the cover layer thinner to avoid unwanted optical effects, the laser beam can be focused to a smaller spot. This allows more information to be stored in the same area. In addition to the optical improvements, Blu-ray Discs feature improvements in data encoding that further increase the capacity. (See Compact disc for information on optical discs' physical structure.)

Hard-coating technology

Since the Blu-ray data layer is closer to the surface of the disk, compared to the DVD standard, it was at first more vulnerable to scratches. The first discs were housed in cartridges for protection. Advances in polymer technology eventually made the caddies unnecessary.

TDK was the first company to develop a working scratch protection coating for Blu-ray discs. It was named Durabis. In addition, both Sony and Panasonic's replication methods include proprietary hard-coat technologies. Sony's rewritable media are sprayed with a scratch-resistant and antistatic coating. Verbatim recordable and rewritable Blu-ray Disc discs use their own proprietary hard-coat technology called ScratchGuard.

Software standards

Codecs

Codecs are compression schemes that store audio and video more efficiently, either giving longer play time or higher quality per megabyte. There are both lossy and lossless compression techniques.

The BD-ROM specification mandates certain codec compatibilities for both hardware decoders (players) and the movie-software (content). For video, all players are required to support MPEG-2, H.264/AVC, and SMPTE VC-1. MPEG-2 is the codec used on regular DVDs, which allows backwards compatibility. H.264/AVC was developed by MPEG and VCEG as a modern successor of MPEG-2. VC-1 is another MPEG-4 derivative codec mostly developed by Microsoft. BD-ROM titles with video must store video using one of the three mandatory codecs. Multiple codecs on a single title are allowed.

The choice of codecs affects the producer's licensing/royalty costs, as well as the title's maximum runtime, due to differences in compression efficiency. Discs encoded in MPEG-2 video typically limit content producers to around two hours of high-definition content on a single-layer (25 GB) BD-ROM. The more advanced video codecs (VC-1 and H.264) typically achieve a video runtime twice that of MPEG-2, with comparable quality.

www.dolby.com/assets/pdf/tech_library/DPlus_TrueHD_whitepaper.pdf Dolby Audio Coding for Future Entertainment Formats](PDF)</ref>//www.dolby.com/assets/pdf/tech_library/DPlus_TrueHD_whitepaper.pdf Dolby Audio Coding for Future Entertainment Formats](PDF)</ref>

For users recording digital television programming, the recordable Blu-ray Disc standard's datarate of 54 Mbit/s is more than adequate to record high-definition broadcasts from any source (IPTV, cable/satellite, or terrestrial). For Blu-ray Disc movies the maximum transfer rate is 48 Mbit/s (1.5x) (both audio and video payloads together), of which a maximum of 40 Mbit/s can be dedicated to video data. This compares favorably to the maximum of 36.55 Mbit/s in HD DVD movies for audio and video data.<ref>Modèle:Cite webwww.foxnews.com/story/0,2933,189960,00.html//www.blu-ray.com/faq/</ref>

Java software support

Main article: BD-J

At the 2005 JavaOne trade show, it was announced that Sun Microsystems' Java cross-platform software environment would be included in all Blu-ray Disc players as a mandatory part of the standard. Java is used to implement interactive menus on Blu-ray Discs, as opposed to the method used on DVD video discs, which uses pre-rendered MPEG segments and selectable subtitle pictures, which is considerably more primitive and less seamless. Java creator James Gosling, at the conference, suggested that the inclusion of a Java Virtual Machine as well as network connectivity in BD devices will allow updates to Blu-ray Discs via the Internet, adding content such as additional subtitle languages and promotional features that are not included on the disc at pressing time. This Java Version is called BD-J and is a subset of the Globally Executable MHP (GEM) standard. GEM is the world-wide version of the Multimedia Home Platform standard.

Region codes

Blu-ray discs may be encoded with a region code, intended to restrict the area of the world in which they can be played; similar to the DVD region codes. Blu-ray players sold in a certain region should only be able to play discs encoded for that region. The purpose of this system is to allow motion picture studios to control the various aspects of a release (including content, date, and, in particular, price) according to the region. Discs may also be produced without region coding, so they can be played on all devices.

bluray.highdefdigest.com/click.html//www.emedialive.com/Articles/ReadArticle.aspx?ArticleID=11392

This arrangement places the countries of the major Blu-ray manufacturers (Japan, Korea, Malaysia) in the same region as the U.S., thus ensuring early releases of U.S. content to those markets. Reportedly, early BD releases (including Casino Royale) are "ALL" region and therefore compatible in various BD players around the globe.

Digital rights management (DRM)

The Blu-ray Disc format employs several layers of Digital rights management.<ref name="dellbd-romprotection">Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.dell.com/downloads/global/vectors/brcp.pdf</ref><ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.blu-raydisc.com/assets/downloadablefile/5th japan 05-13343.pdf</ref> They have been at least partially circumvented.

Advanced Access Content System (AACS) is a standard for content distribution and digital rights management. It is developed by AACS Licensing Administrator, LLC (AACS LA), a consortium that includes Disney, Intel, Microsoft, Matsushita (Panasonic), Warner Bros., IBM, Toshiba and Sony.

Since appearing in devices in 2006, several successful attacks have been made on the format. The first known attack relied on the trusted client problem. In addition, decryption keys have been extracted from a weakly protected player (WinDVD). However, even though some AACS cryptographic keys have been compromised, new releases will use new, uncompromised keys.^{[citation needed]}

www.cryptography.com/technology/spdc/bluray.html</ref> BD+ is effectively a small virtual machine embedded in authorized players. It allows content providers to include executable programs on Blu-ray Discs. Such programs can:<ref name="dellbd-romprotection"/>//www.cryptography.com/technology/spdc/bluray.html</ref> BD+ is effectively a small virtual machine embedded in authorized players. It allows content providers to include executable programs on Blu-ray Discs. Such programs can:<ref name="dellbd-romprotection"/>

• examine the host environment, to see if the player has been tampered with. Every licensed playback device manufacturer must provide the BD+ licensing authority with memory footprints that identify their devices.

• verify that the player's keys have not been changed.
• execute native code, possibly to patch an otherwise insecure system.
• transform the audio and video output. Parts of the content will not be viewable without letting the BD+-program unscramble it.

If a playback device manufacturer finds that its devices have been hacked, it can potentially release BD+-code that detects and circumvents the vulnerability. These programs can then be included in all new content releases.

www.bdplusllc.com/home/list_of_adopters_content_participants_and_eligible_code_developers BD+ website].//www.bdplusllc.com/home/list_of_adopters_content_participants_and_eligible_code_developers BD+ website].

BD+ was made available for content publishers in June 2007.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.blu-ray.com/news/?id=268</ref> The first titles using BD+ were released in October the same year. Several players had problems playing back those titles.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//arstechnica.com/news.ars/post/20071007-new-blu-ray-discs-with-bd-drm-failing-to-play-on-some-devices.html</ref> BD+ has been circumvented by the developers of the program AnyDVD as of version 6.1.9.6 beta.<ref>Modèle:Cite webwww.foxnews.com/story/0,2933,189960,00.html//www.engadgethd.com/2007/11/07/slysofts-latest-anydvd-beta-cracks-bd/</ref>

BD-ROM Mark is a small amount of cryptographical data that is stored physically differently from normal Blu-ray Disc data. Bit-by-bit copies that do not replicate the BD-ROM Mark are impossible to decode. A specially licensed piece of hardware is required to insert the ROM-mark into the media during replication. Through licensing of the special hardware element, the BDA believes that it can eliminate the possibility of mass producing BD-ROMs without authorization.

When the first AACS keys were leaked, some Blu-ray titles became available on file-sharing networks. There is also a commercial PC software player (AnyDVD HD) that allowed users to watch Blu-ray Disc movies on non-HDCP compliant PC hardware or copy them.

Player profiles

The BD-ROM specification defines four profiles of Blu-ray Disc players; in addition to the three listed in the table below, there is a fourth audio-only profile that does not require video decoding or BD-J.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.gizmorepublic.com/media/blu-ray-profiles-everything-you-wanted-know-1270</ref> All the video-based profiles are required to have a full implementation of BD-J, but with varying levels of hardware support.

^ a This is used for storing audio/video and title updates. It can either be built in memory or removable media, such as a memory card or a USB flash memory.

^ b A secondary audio decoder is typically used for interactive audio and commentary

On November 1 2007, the Grace Period Profile was superseded by "Bonus View" as the minimum profile for new players released to the market.<ref name="BonusView">Modèle:Cite webwww.foxnews.com/story/0,2933,189960,00.html//www.videobusiness.com/article/CA6495668.html</ref> With the exception of the PlayStation 3, profile 1.0 players cannot be upgraded to be Bonus View compliant.<ref>Does Blu-ray Profile 1.1 make past players obsolete?</ref> On December 17, 2007, the PlayStation 3 became Bonus View 1.1 compliant through PlayStation 3 System Software version 2.10.<ref>Modèle:Cite webwww.foxnews.com/story/0,2933,189960,00.html//blog.us.playstation.com/2007/12/17/firmware-update-v210/</ref>

www.highdefdigest.com/news/show/Joshua_Zyber/High-Def_FAQ:_Blu-ray_Profiles_Explained/1186| title=High-Def FAQ: Blu-ray Profiles Explained| first=Joshua| last=Zyber| publisher=highdefdigest.com| date=2007-11-23| accessdate=2007-12-18}}</ref>//www.highdefdigest.com/news/show/Joshua_Zyber/High-Def_FAQ:_Blu-ray_Profiles_Explained/1186| title=High-Def FAQ: Blu-ray Profiles Explained| first=Joshua| last=Zyber| publisher=highdefdigest.com| date=2007-11-23| accessdate=2007-12-18}}</ref>

Backward compatibility

While it is not compulsory for manufacturers; the Blu-ray Disc Association recommends that Blu-ray Disc drives should be capable of reading standard DVDs for backward compatibility. For instance, Samsung's first Blu-ray Disc drive can read CDs, regular DVDs, and Blu-ray Discs. All other Blu-ray Disc players released are also capable of DVD playback, though not all support CD playback. This includes Sony, Panasonic, Philips, LG, Pioneer and PC-based players from Alienware, Sony, and Dell.

List of Blu-ray devices

See List of Blu-ray devices

Corporate support

Main article: List of corporations supporting Blu-ray

Blu-ray Disc has gained a large amount of support in the corporate world,<ref>Modèle:Cite webwww.foxnews.com/story/0,2933,189960,00.html//www.blu-raydisc.com/general information/Section-14009/Index.html</ref> with companies such as Apple, Dell, and Panasonic backing it. Blu-ray Disc was started by Hitachi, LG, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, and Thomson in February 19, 2002, with Panasonic, Sony, Pioneer, and Philips as the back-bone of the foundation.<ref>{{cite web

bluray.highdefdigest.com/click.html//www.sony.net/SonyInfo/News/Press_Archive/200202/02-0219E/
| title = Large Capacity Optical Disc Video Recording Format "Blu-ray Disc" Established
| publisher=SONY Press Release
| language =
| date=  February 19, 2002
| accessdate = 2007-08-31

}}</ref> Several members of the Blu-ray organization's Board of Directors who had originally pledged to support Blu-ray Disc later also supported HD DVD, such as Hewlett-Packard, Samsung, and LG.

Among the movie studios, Blu-ray Disc is currently exclusively supported in the United States by Sony Pictures Entertainment and MGM (20% of MGM's stake is owned by Sony) as well as Disney, 20th Century Fox, and Lionsgate. Outside of the United States, movies from these studios are often distributed by different companies, such as StudioCanal in Europe. Thus many of these Blu-ray exclusive titles are available outside the U.S. on HD DVD.<ref name="HDOutsideUS">Modèle:Cite webwww.foxnews.com/story/0,2933,189960,00.html//www.audioholics.com/news/editorials/blu-rays-dirty-little-secret</ref> Likewise, movies that are exclusive to HD DVD in the United States have Blu-ray releases in other regions. An example of this is the Universal Studios film Bruce Almighty, which has been released exclusively on HD DVD in the U.S., but has been released as a Blu-ray exclusive in Europe due to the distribution rights held by Buena Vista.^{[citation needed]} Many Blu-ray discs are multi-region, making import of these titles easier.<ref>Region Coded/Region Free compatibility list</ref>

It is non-exclusively supported by Warner Bros., and New Line Cinema. Warner Bros. has several HD DVD exclusive titles at the moment that are scheduled for release on Blu-ray in the near future. It should be noted that some of New Line Cinema's titles, the first being Hairspray, were originally announced as limited time Blu-ray exclusives due to lack of region coding with HD DVD.<ref>{{cite webwww.foxnews.com/story/0,2933,189960,00.html//www.hddvd.com/go.php/region-coding-delays-the-hd-dvd-release-of-new-line%e2%80%99s-hairspray/|title=hddvd.com - New line titles delayed for HD DVD due to lack of region coding}}</ref><ref>Modèle:Cite webwww.foxnews.com/story/0,2933,189960,00.html//www.highdefdigest.com/news/show/New Line/Disc Announcements/New Line Jumps Into High-Def with Hairspray on Blu-ray HD DVD to Follow in 2008/958</ref> All future catalog titles will be released simultaneously in both formats.

It had been reported by various sources (PC World, Ars Technica, CNN, et al) that pornography had been disallowed on Blu-ray Disc, which may have had an effect on the success of the format.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//arstechnica.com/news.ars/post/20070112-8602.html</ref> However, this is inaccurate, as both formats have said they fully support all material, including porn, and have no control over what companies release with their license.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.informationweek.com/news/showArticle.jhtml?articleID=196903070</ref> Blu-ray is currently exclusively backed by several adult-movie studios/publishers,<ref>Modèle:Cite webwww.foxnews.com/story/0,2933,189960,00.html//www.pcworld.com/article/id,135222/article.html</ref> including Taisei Co. Ltd. and Total Media Agency Inc. Contrary to many internet blogs, it has been reported by ABC News that the porn industry will not be a factor in the current format war.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//abcnews.go.com/Technology/story?id=2835806&page=1</ref> The main reason is that many pornographic websites have movie downloads as an option, thus making the disc format less important.

blockbuster.mediaroom.com/index.php?s=press_releases&item=727 Blockbuster to Expand Blu-Ray to 1,700 Stores], Blockbuster Inc. Press Releases 2007-06-18.</ref><ref>{{cite web//blockbuster.mediaroom.com/index.php?s=press_releases&item=727 Blockbuster to Expand Blu-Ray to 1,700 Stores], Blockbuster Inc. Press Releases 2007-06-18.</ref><ref>{{cite web

bluray.highdefdigest.com/click.html//www.pittsburghlive.com/x/pittsburghtrib/news/s_513097.html
| title = Blockbuster to favor Blu-ray high-definition discs over rival HD DVD format
| accessdate = 2007-06-17
| year = 2007

}}</ref><ref>{{cite web

bluray.highdefdigest.com/click.html//www.b2i.us/profiles/investor/ResLibraryView.asp?BzID=553&ResLibraryID=20345&Category=1027
| title = Blockbuster to Expand Blu-Ray to 1,700 Stores
| accessdate = 2007-06-17
| year = 2007

}}</ref>

Netflix, the world's largest online movie rental service<ref>{{cite web

bluray.highdefdigest.com/click.html//www.netflix.com/MediaCenter?id=5379#about 
| title = About Netflix 
| accessdate = 2007-12-13
| year = 2007}}</ref>, offers titles in both HD-DVD and Blu-Ray formats. According to a new Internet tracking report, although Netflix's Blu-ray pages receive more hits, users are more likely to set HD DVD as their preferred format.<ref>{{cite web  
bluray.highdefdigest.com/click.html//www.tgdaily.com/content/view/34235/113/
| title = Netflix sees stronger loyalty for HD DVD than Blu-ray 
| accessdate = 2007-12-13
| year = 2007}}</ref>

www.reuters.com/article/businessNews/idUSN2643741920070726</ref> While Target will not carry HD DVD stand alone players on its shelves, the chain will continue to sell both Blu-ray Disc and HD DVD movies in all stores and HD DVD players online.<ref>{{cite web//www.reuters.com/article/businessNews/idUSN2643741920070726</ref> While Target will not carry HD DVD stand alone players on its shelves, the chain will continue to sell both Blu-ray Disc and HD DVD movies in all stores and HD DVD players online.<ref>{{cite web

bluray.highdefdigest.com/click.html//www.forbes.com/feeds/ap/2007/07/25/ap3952696.html
| title = Target to Promote Blu-Ray DVD Format
| accessdate = 2007-07-29
| year = 2007

}}</ref> The LA Times reports that the deal to promote Sony Blu-ray Disc stand alone players was the result of a bidding war, in which Sony and three studios reportedly paid a "jaw-dropping" sum for the end cap displays.<ref>{{cite web

bluray.highdefdigest.com/click.html//www.latimes.com/entertainment/news/business/la-fi-dvdwar10sep10,1,5792818.story?coll=la-headlines-business-enter&ctrack=5&cset=true
| title = A high-definition fight scene in slow motion
| accessdate = 2007-09-10
| year = 2007

}}</ref>

www.the-numbers.com/market/2007.php Paramount is box office leader in 2007]</ref><ref>{{cite web//www.the-numbers.com/market/2007.php Paramount is box office leader in 2007]</ref><ref>{{cite web

bluray.highdefdigest.com/click.html//money.cnn.com/news/newsfeeds/articles/newstex/AFX-0013-19015486.htm
| title = Paramount to drop Blu-ray high-def DVDs
| accessdate = 2007-08-20
| year = 2007

}}</ref> Movies directed by Steven Spielberg are not included in this announcement, as Spielberg controls his films.<ref>{{cite web

bluray.highdefdigest.com/click.html//www.smh.com.au/news/Technology/Paramount-to-Drop-BluRay-HighDef-DVDs/2007/08/21/1187462196364.html
| title = Paramount to drop Blu-ray high-def DVDs {Spielberg)
| accessdate = 2007-08-20
| year = 2007

}}</ref> In an interview with PC World, Alan Bell, the Executive Vice President and Chief Technology Officer for Paramount Pictures, stated the exclusive support for HD DVD is currently indefinite.<ref>{{cite web

bluray.highdefdigest.com/click.html//www.pcworld.com/article/id,136253-c,dvdtechnology/article.html
| title = Interview with Executive Vice President of Paramount Pictures on HD DVD and Blu-Ray
| accessdate = 2007-08-21
| year = 2007

}}</ref> However, two Viacom executives who spoke to the New York Times disclosed that the terms of the agreement were for $150 million in incentives in exchange for an exclusivity period of at least 18 months, or through the next two holiday seasons.<ref>{{cite web

bluray.highdefdigest.com/click.html//www.nytimes.com/2007/08/21/technology/21disney.html?ex=1345435200&en=fe619b851abc0231&ei=5124&partner=permalink&exprod=permalink 
| title = Two Studios to Support HD DVD Over Rival 
| accessdate = 2007-08-21
| year = 2007}}</ref>

In response to these reports of a $150 million deal, DreamWorks Animation CEO Jeffrey Katzenberg stated that it was disingenuous for other companies to suggest that they were not compensated for endorsing Blu-ray.<ref>{{cite web

bluray.highdefdigest.com/click.html//www.variety.com/article/VR1117972267.html?categoryid=13&cs=1 
| title = Katzenberg stands behind Spielberg 
| accessdate = 2007-09-19
| year = 2007}}</ref>

www.blu-ray.com/news/index.php?id=532 Blu-ray.com - HTSA to Support Blu-ray Exclusively]</ref>//www.blu-ray.com/news/index.php?id=532 Blu-ray.com - HTSA to Support Blu-ray Exclusively]</ref>

Blu-ray Disc / HD DVD comparison

Main article: Comparison of high definition optical disc formats

Modèle:Cleanup-jargon The primary rival to Blu-ray Disc is HD DVD. As of November 2007, HD DVD has the advantage in maximum disc capacity (51 GB triple-layer versus 50 GB dual-layer). However, no movies are currently scheduled to be released on the triple-layer disc; thus, Blu-ray has the advantage in currently available capacity.<ref name="tripleApproved">Modèle:Cite webwww.foxnews.com/story/0,2933,189960,00.html//www.dvdforum.org/40scmtg-resolution.htm</ref> It is unknown at this time whether the final triple-layer HD DVD specification will be compatible with current players.<ref>{{cite web bluray.highdefdigest.com/click.html//www.betanews.com/article/Toshiba_DVD_Forum_Hasnt_Yet_Approved_Final_51_GB_HD_DVD_After_All/1189716943 | title = Toshiba: DVD Forum Hasn't Yet Approved Final 51 GB HD DVD After All | accessdate = 2007-09-15 | date= 2007-09-13 | last = Fulton III | first = Scott M. | work = BetaNews | language = English www.blu-raystats.com/index.php Blu-ray stats]</ref> while almost all HD DVD movies are in the 30 GB dual layer format.<ref>Frequently updated list of historical release dates and disc capacities, HD DVD NEWS, High-Def Digest, 15 April 2007</ref>//www.blu-raystats.com/index.php Blu-ray stats]</ref> while almost all HD DVD movies are in the 30 GB dual layer format.<ref>Frequently updated list of historical release dates and disc capacities, HD DVD NEWS, High-Def Digest, 15 April 2007</ref>

In terms of audio/video compression, Blu-ray Disc and HD DVD are similar on the surface: both support MPEG-2, VC-1, and H.264 for video compression; and Dolby Digital, PCM, and DTS for audio compression. The first generation of Blu-ray Disc movies released used MPEG-2 (the standard currently used in DVDs, although encoded at a much higher video resolution and a much higher bit rate than those used on conventional DVDs), while initial HD DVDs releases used the VC-1 codec. Due to greater total disc capacity, the Blu-ray Disc producers may choose in the future to utilize a higher maximum video bit rate, as well as potentially higher average bit rates. As of November 2007, 41% of Blu-ray Discs are encoded in MPEG-2 while AVC is used on 33% of discs and VC-1 on 26%.<ref name="bluraystats"/>

www.dolby.com/assets/pdf/tech_library/DPlus_TrueHD_whitepaper.pdf Dolby Digital plus True HD whitepaper] at www.dolby.com</ref> Both formats optionally support DTS-HD High Resolution Audio, a lossy compression scheme that extends the core DTS audio for better fidelity but yet is still not lossless.//www.dolby.com/assets/pdf/tech_library/DPlus_TrueHD_whitepaper.pdf Dolby Digital plus True HD whitepaper] at www.dolby.com</ref> Both formats optionally support DTS-HD High Resolution Audio, a lossy compression scheme that extends the core DTS audio for better fidelity but yet is still not lossless.

www.blu-ray.com/faq/#bluray_audio_codecs Blu-Ray audio codecs FAQs] at blu-ray.com</ref> As of November 2007, 7% of Blu-ray Discs are encoded in Dolby TrueHD while DTS-HD Master Audio is used on 12% on discs.<ref name="bluraystats"/> In total, 60% of Blu-ray Discs have either uncompressed or lossless audio. HD DVD also supports LPCM, but unlike Blu-ray, it has mandatory support for Dolby TrueHD, although only 20% of HD DVD movies have lossless audio.^{[citation needed]}//www.blu-ray.com/faq/#bluray_audio_codecs Blu-Ray audio codecs FAQs] at blu-ray.com</ref> As of November 2007, 7% of Blu-ray Discs are encoded in Dolby TrueHD while DTS-HD Master Audio is used on 12% on discs.<ref name="bluraystats"/> In total, 60% of Blu-ray Discs have either uncompressed or lossless audio. HD DVD also supports LPCM, but unlike Blu-ray, it has mandatory support for Dolby TrueHD, although only 20% of HD DVD movies have lossless audio.^{[citation needed]}

blogs.msdn.com/ptorr/archive/2006/03/15/HDFacts.aspx|title=High Definition Facts | accessdate=2006-12-01}}</ref> There is no impact on picture resolution and minimal impact on storage space as a result of this, as the HD DVD format often uses the same encoded video—it simply adds notational overhead.Modèle:Huh//blogs.msdn.com/ptorr/archive/2006/03/15/HDFacts.aspx|title=High Definition Facts | accessdate=2006-12-01}}</ref> There is no impact on picture resolution and minimal impact on storage space as a result of this, as the HD DVD format often uses the same encoded video—it simply adds notational overhead.Modèle:Huh

There is no Region Coding in the existing HD DVD specification, which means that titles from any country can be played in players in any other country. However, a significant percentage of Blu-ray disks have Region Coding and will only play in players sold in the corresponding geographic region.

www.news.com/Blu-ray-outsells-HD-DVD-in-U.S.-for-first-nine-months/2100-1041_3-6214944.html | title=Blu-ray outsells HD DVD in US for First nine months of 2007 - Reuters - Cnet news}}</ref> However, those figures are dwarfed by the sales of regular DVDs. Combined, the two high-def disc formats accounted for only 2.5 % of overall disc sales during the first half of 2007.<ref> Disc Sales: Hard Numbers in for First Half of 2007

. highdefdigest.com
 (2007-08-15)
   

. Retrieved on 2007-10-25. </ref>//www.news.com/Blu-ray-outsells-HD-DVD-in-U.S.-for-first-nine-months/2100-1041_3-6214944.html | title=Blu-ray outsells HD DVD in US for First nine months of 2007 - Reuters - Cnet news}}</ref> However, those figures are dwarfed by the sales of regular DVDs. Combined, the two high-def disc formats accounted for only 2.5 % of overall disc sales during the first half of 2007.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.highdefdigest.com/news/show/Industry Trends/Disc Sales/Disc Sales: Hard Numbers in for First Half of 2007/862</ref>

Ongoing development

Although the Blu-ray Disc specification has been finalized, engineers continue working to advance the technology. Quad-layer (100 GB) discs have been demonstrated on a drive with modified optics (TDK version) and standard unaltered optics ("Hitachi used a standard drive.").<ref>{{cite web

bluray.highdefdigest.com/click.html//www.tdk.com/procommon/press/article.asp?site=con&recid=3
| title = TDK ANNOUNCES 100GB BLUE LASER DISC TECHNOLOGY
| language =
| accessdate = 2007-09-27
| year = 2005

}}</ref><ref>{{cite web

bluray.highdefdigest.com/click.html//www.cdrinfo.com/Sections/News/Details.aspx?NewsId=19493
| title =  Hitachi Demos Four-Layer Blu-Ray Disc Playback

}}</ref> Hitachi stated that such a disc could be used to store 7 hours of 32 Mbit/s video (HDTV) or 3.5 hours of 64 Mbit/s video (Cinema 4K). Furthermore TDK announced in August 2006 that they have created a working experimental Blu-ray Disc capable of holding 200 GB of data on a single side, using six 33 GB data layers.<ref name="TDK200GB_announcement">{{cite web

bluray.highdefdigest.com/click.html//www.tdk.com/procommon/press/article.asp?site=con&recid=127
| title = TDK ANNOUNCES BLUE LASER DISC TECHNOLOGY TO SUPPORT 200 GB CAPACITY
| publisher = TDK
| accessdate = 2006-11-27
| date = August 31 2006

}}</ref>

Also behind closed doors at CES 2007, Ritek has revealed that they had successfully developed a High Definition optical disc process that extends the disc capacity of both competing formats to 10 layers. That increases the capacity of the discs to 250 GB for Blu-ray compared to 170 GB (HD DVD now permits 17GB per layer^{[citation needed]}) for HD DVD using the same process. However, they noted that the major obstacle is that current reader and writer technology does not support the additional layers.<ref> {{cite web bluray.highdefdigest.com/click.html//www.dailytech.com/article.aspx?newsid=5656 | title = Three HD Layers Today, Ten Tomorrow | accessdate = 2007-04-24 | date= 2007-01-10 | last = Yam | first = Marcus | work = DailyTech | language = English }}</ref>

JVC has developed a three layer technology that allows putting both standard-definition DVD data and HD data on a BD/DVD combo. If successfully commercialized, this would enable the consumer to purchase a disc which could be played on current DVD players, and reveal its HD version when played on a new BD player.<ref>{{cite web

bluray.highdefdigest.com/click.html//www.jvc-victor.co.jp/english/press/2004/bd-dvd.html
| title = Blu-ray/ DVD Combo ROM Disc Technology
| accessdate = 2006-05-30
| year = 2006

}}</ref> This hybrid disc does not appear to be ready for production and no titles have been announced that would utilize this disc structure.

www.blu-ray.com/news/?id=559 Hitachi Develops 100GB Blu-ray disc]</ref> TDK has also produced a 200 GB six-layer prototype.<ref name="TDK200GB_announcement"/>//www.blu-ray.com/news/?id=559 Hitachi Develops 100GB Blu-ray disc]</ref> TDK has also produced a 200 GB six-layer prototype.<ref name="TDK200GB_announcement"/>

Variants

BD9 / Mini-Blu-ray Disc

BD9 is a red laser DVD with BD contents on it. This disc should be rotated at 3x speed or more to satisfy the minimum transfer rate of 30.24 Mbit/s. These disks can be used for private storing and can be authored even without implementing AACS.<ref>{{cite web bluray.highdefdigest.com/click.html//www.hdtvtotal.com/module-pagesetter-viewpub-tid-1-pid-1051.html | title = Mini Blu-ray Disc: Guide for mini-Blu-ray-Disc Authoring | accessdate = 2007-08-19 | format = HTML | work = | language = English }} </ref> BD9 was originally proposed by Warner Home Video, as a cost-effective alternative to regular Blu-ray discs.<ref>Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.cdrinfo.com/Sections/News/Details.aspx?NewsId=16769</ref> It is similar to HD DVD's 3x DVD

AVCREC

AVCREC is a standard for storing BD content on red laser DVDs using H.264/MPEG-4 AVC compression.<ref> Modèle:Cite web www.foxnews.com/story/0,2933,189960,00.html//www.pcworld.com/article/id,138121-page,1/article.html</ref> It is similar to HD REC for HD DVD.

Blu-ray Disc recordable

Main article: Blu-ray Disc recordable

Blu-ray Disc recordable refers to two optical disc formats that can be recorded with an optical disc recorder. BD-R discs can be written to once, whereas BD-RE can be erased and re-recorded multiple times. As of March 2007, BD-R/RE drives up to 4x retail are sold for about US$600 and 2x single-layer BD-R discs, with a capacity of 25 GB, can be found for around US$12. The theoretical maximum for Blu-ray Discs is about 12x as the speed of rotation (10,000 rpm) causes too much wobble for the discs to be read properly, similar to the 20x and 52x respective maximum speeds of DVDs and CDs.

HD DVD / Blu-Ray hybrid discs

Warner Bros. officially announced Total Hi Def (THD) at CES 2007. Total Hi Def (Total HD) hybrid discs supports both HD DVD and Blu-ray, HD DVD on one side (up to two layers) and Blu-ray on the other side (up to two layers). Despite initially announcing that Total HD would be ready by the second half of 2007, on June 27 2007, Warner Bros. issued a press release stating that they would be delaying the launch of Total HD discs until early 2008. As of September 2007, no specific titles have yet been announced.

See also

• List of Blu-ray Movies
• Blu-ray Disc Association
• Format war
• Professional Disc for DATA (PDD or ProDATA)
• Comparison of high definition optical disc formats
• MUSE LD – an earlier optical disc which contained analog HDTV signals
• D-VHS – a tape-based format that allows recording of 720 or 1080 high-def DTV, while remaining compatible with older VHS libraries
• Blu-ray Disc recordable

Alternative disc technologies

• HD DVD
• AVCHD
• Digital Multilayer Disk – the successor technology to Fluorescent Multilayer Disc
• Enhanced Versatile Disc (EVD)

www.boser.com.tw/news/20041227.htm Taiwanese backed] red laser format//www.boser.com.tw/news/20041227.htm Taiwanese backed] red laser format

• Fluorescent Multilayer Disc
• Holographic Versatile Disc – standards with 200 and 300 GB storage are under development and prototypes expected in 2008
• 3D optical data storage – a next-generation technology expected to provide TB-capacity discs
• PH-DVD
• Protein-coated disc
• Tapestry Media
• Ultra Density Optical
• Versatile Multilayer Disc
• LS-R – a "layer selection" technology allowing the stacking of very large numbers of DVD-like data layers in a single disc.

References

External links

Modèle:Portal www.blu-raydisc.com/ Blu-ray Disc Association]//www.blu-raydisc.com/ Blu-ray Disc Association] www.blu-raydisc.com/ Blu-ray Disc Association]//www.blu-raydisc.info/ Blu-ray Disc License Web Site] www.blu-raydisc.com/ Blu-ray Disc Association]//www.aacsla.com/home AACS LA] www.blu-raydisc.com/ Blu-ray Disc Association]//panasonic.net/blu-ray/index.html Panasonic Blu-ray Portal Site] www.blu-raydisc.com/ Blu-ray Disc Association]//www.us.playstation.com/PS3/About/BluRay PlayStation.com: Blu-ray Disc Technology] www.blu-raydisc.com/ Blu-ray Disc Association]//www.dolby.com/ Dolby Laboratories] www.blu-raydisc.com/ Blu-ray Disc Association]//www.dtsonline.com/ DTS] www.blu-raydisc.com/ Blu-ray Disc Association]//www.hdmi.org/ HDMI Licensing] www.blu-raydisc.com/ Blu-ray Disc Association]//www.emedialive.com/Articles/ReadArticle.aspx?ArticleID=11392 The Authoritative Blu-ray Disc FAQ] by Hugh Bennett www.blu-raydisc.com/ Blu-ray Disc Association]//www.digital-digest.com/highdefdvd/faq.html The High Definition DVD FAQ] – FAQ for Blu-ray, HD DVD, EVD, FVD... www.blu-raydisc.com/ Blu-ray Disc Association]//www.hidefdvd.com/browse-studio-bluray.htm Studios Currently Supporting Blu-ray]

News

www.blu-raydisc.com/ Blu-ray Disc Association]//pro.jvc.com/pro/pr/2004/victor/041224BDDVD_combo_ROM_Disc.pdf JVC Develops World's First Blu-ray/DVD Combo ROM Disc Technology] – JVC Press Releases 2004-12-24. www.blu-raydisc.com/ Blu-ray Disc Association]//news.bbc.co.uk/1/hi/technology/4921784.stm Next-generation DVD battle begins] – BBC News Online 2006-04-19. www.blu-raydisc.com/ Blu-ray Disc Association]//techon.nikkeibp.co.jp/english/NEWS_EN/20060427/116681/?ST=english TDK Prototypes 200 GB Recordable Blu-ray Disc with Six Layers] – Nikkei Business Publications 2006-04-27. www.blu-raydisc.com/ Blu-ray Disc Association]//techon.nikkeibp.co.jp/english/NEWS_EN/20070111/126348/ Hitachi Demonstrates 4 Layer BD Playback Using 'Standard Drive'] – Nikkei Business Publications 2007-01-11. www.blu-raydisc.com/ Blu-ray Disc Association]//www.sony.net/SonyInfo/News/Press/200704/07-037E/index.html Establishment of Industry-leading Monthly Capacity of 1.7 million Blue-violet Diodes(lower costs)] – SONY Press Releases 2007-04-07. www.blu-raydisc.com/ Blu-ray Disc Association]//www.ultimateavmag.com/news/61407hddvd/ Mixed Messages From HD DVD Camp] – Ultimate AV News Desk 2007-06-14. www.blu-raydisc.com/ Blu-ray Disc Association]//www.videostoremag.com/news/html/breaking_article.cfm?sec_id=2&&article_ID=10786 Starz to go Blu] – Home Media Magazine Top Story 2007-06-19. www.blu-raydisc.com/ Blu-ray Disc Association]//forum.doom9.org/showthread.php?t=120988 Volume Unique Keys for released Blu-ray titles] Modèle:Home video

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