Blu-ray Disc

Un article de Vev.

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

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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> Seán Byrne

     (2007-02-23)
   
.    Significant progress made toward creation of joint Blu-ray Disc™ patent license (Press Release) 
. cdrfreaks.com

. Retrieved on 2007-10-17. </ref>

As of November 25 2007, 415<ref> 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

. </ref>

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.

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History

Modèle:Optical disc authoring

Image:Blu-ray disc (BD-RE).JPG

A blank rewritable Blu-ray disc (BD-RE)

In the mid 1990s, commercial HDTV sets were finally starting to enter a larger market. However, there was no good, cheap way to record or play back HD content. Indeed, there was no media that could store that amount of data, except JVC's Digital VHS and Sony's HD Betacam.<ref> Evan Ramstad

     (1998-04-08)
   
.    In HDTV Age, Successor to VCR Still Seems to Be a Long Way Off 
. online.wsj.com

. Retrieved on 2007-10-18. </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> Martyn Williams

     (2002-08-12)
   
.    Opening the Door for New Storage Options 
. pcworld.com

. Retrieved on 2007-10-18. </ref>

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Origins

Sony started two projects applying the new diodes: UDO (Ultra Density Optical) and DVR Blue (together with Pioneer), a format of rewritable discs which would eventually become Blu-ray (more specifically, BD-RE).<ref> S.B. Luitjens

     (2001-06-15)
   
.    Blue laser bolsters DTV storage, features 
. planetanalog.com

. Retrieved on 2007-10-19. </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> Sony Shows 'DVR-Blue' Prototype

. cdrinfo.com
 (2000-10-11)

. Retrieved on 2007-10-17. </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> Barry Fox

     (2002-02-19)
   
.    Replacement for DVD unveiled 
. newscientist.com

. Retrieved on 2007-10-17. </ref> and the Blu-ray Disc Association was founded by the nine initial members.

The first consumer devices were in stores on April 10, 2001. This device was the Sony BDZ-S77; a BD-RE recorder that was only made available in Japan. The recommended price was US$3800.<ref> Maxim Liadov

.    SONY BDZ-S77 Recorder Review 
. digit-life.com

. Retrieved on 2007-10-19. </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.

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Competition from HD DVD

The DVD Forum (which was chaired by Toshiba) was deeply split over whether to go with the more expensive blue lasers or not. In addition, the proposed Blu-ray disc with its protective caddy was both expensive and physically different from DVD, posing several problems.<ref> Next Generation DVD Born

. bbc.co.uk
 (2002-02-21)

. Retrieved on 2007-11-4. </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> Junko Yoshida

     (2002-03-01)
   
.    Picture's fuzzy for DVD 
. eetimes.com

. Retrieved on 2007-10-19. </ref><ref> Junko Yoshida

     (2001-12-12)
   
.    Forum to weigh Microsoft's Corona as DVD encoder 
. eetimes.com

. Retrieved on 2007-10-19. </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> Philip De Lancie

     (2002-06-01)
   
.    HD on DVD 
. emedialive.com

. Retrieved on 2007-10-19. </ref> In August, Toshiba and NEC announced their competing standard Advanced Optical Disc.<ref> Toshiba, NEC Share Details of Blue-Laser Storage

. pcworld.com
 (2002-08-29)

. Retrieved on 2007-10-18. </ref> It was finally adopted by the DVD forum and renamed HD DVD the next year,<ref> DVD Forum backs Toshiba-NEC format

. theinquirer.net
 (2003-11-28)

. Retrieved on 2007-10-18. </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> Opinion: Trust's worth

.</ref><ref> 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> Junko Yoshida and Yoshiko Hara

     (2003-11-14)
   
.    High-definition DVD format divides industry into rival camps 
. my-esm.com

. Retrieved on 2007-10-19. </ref><ref> Yoshiko Hara

     (2003-11-26)
   
.    HD DVD Format Wins Key Nod From DVD Forum 
. techweb.com

. Retrieved on 2007-10-19. </ref>

In the mean time, Sony spun off Professional Disc for DATA from the Blu-ray project. It was essentially Blu-ray with higher-quality media and components. The devices were too expensive for the consumer mass market. Instead, it was aimed at the professional data storage space market as a replacement for their line of 5.25" MO drives. It was announced in October 2003, with the first devices shipping in December of the same year.<ref> Sony to Launch 23GB Optical Disc

. dvd-recordable.org
 (2003-10-21)

. Retrieved on 2007-10-18. </ref><ref> Tony Smith

     (2003-12-02)
   
.    Sony ships blu-ray 23GB storage system 
. theregister.co.uk

. Retrieved on 2007-10-18. </ref>

[modifier]

Attempts to avoid a format war

The costs of a format war are large, both for consumers and for the industry. In an attempt to avoid starting one, the Blu-ray Disc Association and the DVD Forum attempted to negotiate a compromise in early 2005. One of the issues was that the Blu-ray camp wanted to use a Java-based platform for interactivity (BD-J), while the DVD Forum was promoting Microsoft's "iHD" (which became HDi).<ref> Junko Yoshida

     (2005-04-19)
   
.    Sides close to deal on HD disk format 
. eetasia.com

. Retrieved on 2007-10-19. </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"> Andy Patrizio

     (2007-04-12)
   
.    Who Is Drawing Out The High-Def DVD Stalemate? 
. internetnews.com

. Retrieved on 2007-10-19. </ref> An agreement seemed close, but negotiations proceeded slowly.<ref> Michiyo Nakamoto

     (2005-05-17)
   
.    Sony-Toshiba DVD format talks stall 
. ft.com

. Retrieved on 2007-10-19. </ref>

At the end of June 2005, Sun announced that the Blu-ray Association had chosen the Java-based BD-J interactivity layer instead of Microsoft's HDi. This was based on a BDA board vote favouring BD-J 10 to 4, despite a technical committee previously favouring HDi by a vote of 7 to 5.<ref> Micro-managed copies

.</ref> At the same time, Microsoft and Toshiba jointly announced that they would cooperate in developing high-definition DVD players.<ref> David Cohn

     (2005-06-27)
   
.    Microsoft, Toshiba Gear Up 
. wired.com

. Retrieved on 2007-10-19. </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"> Cliff Edwards, Peter Burrows, Ronald Grover, Tom Lowry and Kenji Hall

     (2005-10-17)
   
.    Daggers Drawn Over DVDs 
. businessweek.com

. Retrieved on 2007-10-19. </ref>

On August 22, 2005, the Blu-ray Disc Association and DVD Forum announced that the negotiations to unify their standards had failed.<ref> Sony, Toshiba fail to unify DVD format - report

. forbes.com
 (2005-08-22)

. Retrieved on 2007-10-19. </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> Susan B. Shor

     (2005-09-27)
   
.    Microsoft, Intel Back Toshiba's HD-DVD 
. ecommercetimes.com

. Retrieved on 2007-10-19. </ref>

Hewlett-Packard (HP) made a last attempt to broker a peace between with Blu-ray Disc Association and Microsoft. The company demanded that the Blu-ray association adopted Microsoft's HDi instead of its own Java solution, and that Blu-ray adopt a mandatory managed copy feature. If the demands weren't met, HP threatened to support HD DVD instead.<ref> Ken Young

     (2005-10-20)
   
.    HP calls for changes to Blu-ray 
. vnunet.com

. Retrieved on 2007-10-19. </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> Robert Jaques

     (2005-10-25)
   
.    HP's Blu-ray move spells doom for HD-DVD 
. vnunet.com

. Retrieved on 2007-10-19. </ref> However, the Blu-ray disc group did not accept HP's proposal.<ref> Blu-Ray Won't Bow to HP's Demands

. foxnews.com
 (2005-11-17)

. Retrieved on 2007-10-19. </ref>

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Blu-ray Disc format finalized and launched

The Blu-ray physical specifications were finished in 2004.<ref> Martyn Williams

     (2004-08-05)
   
.    New Blu-ray Details Emerge 
. pcworld.com

.</ref> In January 2005, TDK announced that they had developed a hard coating polymer for Blu-ray discs.<ref> Exclusive TDK Durabis Coating Technology Makes Cartridge-Free, Ultra-Durable Blu-Ray Discs a Reality

. physorg.com
 (2005-01-09)

. Retrieved on 2007-10-18. </ref> The cartridges, no longer necessary, were scrapped. The BD-ROM specifications were finalized in early 2006.<ref> Tony Smith

     (2006-01-06)
   
.    Blu-ray Disc developers complete specification 
. theregister.co.uk

. Retrieved on 2007-10-17. </ref> AACS LA, a consortium founded in 2004,<ref> Katie Dean

     (2004-07-15)
   
.    Can Odd Alliance Beat Pirates? 
. wired.com

. Retrieved on 2007-10-19. </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> Martyn Williams

     (2005-12-14)
   
.    Toshiba Hints at HD-DVD Delay 
. pcworld.com

. Retrieved on 2007-10-19. </ref> and then delayed again when an important member of the Blu-ray group voiced concerns.<ref> Craig Morris

     (2006-02-14)
   
.    AACS copy protection for Blu-ray disc and HD DVD delayed again 
. heise.de

. Retrieved on 2007-10-19. </ref> At the request of Toshiba, an interim standard was published which did not include some features, like managed copy.<ref> Melissa J. Perenson

     (2006-03-21)
   
.    Burning Questions: No Copying From First High-Def Players 
. pcworld.com

. Retrieved on 2007-10-19. </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> Toshiba Starts Selling HD DVD Players in Japan

. foxnews.com
 (2006-03-31)

. Retrieved on 2007-10-17. </ref><ref> Dan Costa

     (2006-06-15)
   
.    Samsung Ships the First Blu-Ray Player 
. pcmag.com

. Retrieved on 2007-10-17. </ref>

The first Blu-ray Disc titles were released on June 20 2006. The earliest releases used MPEG-2 video compression, the same method used on DVDs. The first releases using the newer VC-1 and AVC codecs were introduced in September 2006.<ref>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> Bracke , Peter M.

     (2006-10-10)
   
.    Click: Blu-ray Disc review 
. HighDefDigest.com

. Retrieved on 2007-09-15. </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> David Katzmaier

     (2006-06-30)
   
.    Samsung BD-P1000 Review 
. cnet.com

. Retrieved on 2007-10-18. </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> Stephanie Prange

     (2007-02-23)
   
.    Blu-ray Tips Scales 
. homemediamagazine.com

. Retrieved on 2007-10-18. </ref> and during the first three quarters of 2007, BD discs outsold HD DVDs by about two to one.<ref> Sarah McBride

     (2007-09-30)
   
.    DVD formats Blu-ray, HD square off 
. charleston.net

. Retrieved on 2007-10-18. </ref>

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Disc structure

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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.)

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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.

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Software standards

[modifier]

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.

For audio, BD-ROM players are required to support Dolby Digital AC-3, DTS, and linear PCM. Players may optionally support Dolby Digital Plus, and lossless formats Dolby TrueHD and DTS HD. BD-ROM titles must use one of mandatory schemes for the primary soundtrack. A secondary audiotrack, if present, may use any of the mandatory or optional codecs.<ref>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> Blu-ray FAQ

. Retrieved on 2007-07-07. </ref>

[modifier]

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.

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Region codes

Image:Blu-ray regions with key.png

Regions for Blu-ray standard<ref> Blu-ray Disc for Video (2006) . Retrieved on 2007-01-14. </ref>

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.

Region code	Area<ref> The Authoritative Blu-ray Disc (BD) FAQ: What is Regional Playback Control? (2006) . Retrieved on 2006-08-29. </ref>
A	North America, Central America, South America, Japan, Taiwan, North Korea, South Korea, Hong Kong, and Southeast Asia.
B	Europe, Greenland, French territories, Middle East, Africa, Australia, and New Zealand.
C	India, Bangladesh, Nepal, Mainland China, Pakistan, Russia, Central, and South Asia.

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.

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Digital rights management (DRM)

The Blu-ray Disc format employs several layers of Digital rights management.<ref name="dellbd-romprotection"> Blu-ray Disc™ Next-Generation Optical Storage: Protecting Content on the BD-ROM

 (PDF)
. DELL

. Retrieved on 2007-05-03. </ref><ref> AJIMA, Kosuke

     (2006-03-29)
   
.    Overview of BD-ROM security 
. Blu-ray Disc Association Content Protection Group

. Retrieved on 2007-05-03. </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]}

[[BD+]] was developed by Cryptography Research Inc. and is based on their concept of Self-Protecting Digital Content.<ref>http://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.

The specifications of the BD+ virtual machine are only available to licensed device manufacturers. A list of licensed adopters is available from the BD+ website.

BD+ was made available for content publishers in June 2007.<ref> Josh

     (2007-06-19)
   
.    BD+ Goes Live 
. blu-ray.com

. Retrieved on 2007-11-02. </ref> The first titles using BD+ were released in October the same year. Several players had problems playing back those titles.<ref> Jeremy Reimer

     (2007-10-07)
   
.    New Blu-ray discs with BD+ DRM failing to play on some devices 
. arstechnica.com

. Retrieved on 2007-11-02. </ref> BD+ has been circumvented by the developers of the program AnyDVD as of version 6.1.9.6 beta.<ref> Darren Murph

     (2007-11-07)
   
.    SlySoft's latest AnyDVD beta cracks BD+ 
. engadgethd.com

. Retrieved on 2007-11-07. </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.

[modifier]

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> Blu-ray profiles, everything you wanted to know

 (2007-12-17)

. Retrieved on 2007-12-19. </ref> All the video-based profiles are required to have a full implementation of BD-J, but with varying levels of hardware support.

Feature<ref> Hugh Bennett (2006-06-01) . The Authoritative BD FAQ: II. Physical, Logical, and Application Specifications . emedialive.com . Retrieved on 2007-10-19. </ref>	BD-Video (Grace Period Profile – Profile 1.0)	Bonus View (Final Standard Profile – Profile 1.1)	BD-Live (Profile 2)
Built-in persistent memory	64 KB	64 KB	64 KB
Local storage capability^[a]	–	256 MB	1 GB
Secondary video decoder (PiP)	Optional	Mandatory	Mandatory
Secondary audio decoder^[b]	Optional	Mandatory	Mandatory
Virtual file system	Optional	Mandatory	Mandatory
Internet connection capability	No	No	Mandatory

^ 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"> Blu-ray Disc Assn. promotes new Bonus View

.</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> Lempel , Eric

     (2007-12-17)
   
.    Firmware Update (v2.10) 
. Sony

. Retrieved on 2007-12-18. </ref>

When software authored with interactive features dependent on "Bonus View" hardware capabilities are played on profile 1.0 players some features may not be available or may offer limited capability. Profile 1.0 players will still be able to play the main feature of the disc, however.<ref> Zyber , Joshua

     (2007-11-23)
   
.    High-Def FAQ: Blu-ray Profiles Explained 
. highdefdigest.com

. Retrieved on 2007-12-18. </ref>

[modifier]

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.

[modifier]

List of Blu-ray devices

See List of Blu-ray devices

[modifier]

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> Companies supporting Blu-ray

. Retrieved on 2007-07-07. </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> Large Capacity Optical Disc Video Recording Format "Blu-ray Disc" Established

. SONY Press Release 
 
 (February 19, 2002)

. Retrieved on 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"> Blu-ray exclusive movies on HD DVD

.</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> hddvd.com - New line titles delayed for HD DVD due to lack of region coding

.</ref><ref> New Line Jumps Into High-Def with 'Hairspray' on Blu-ray; HD DVD to Follow in 2008

.</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> Adult film industry embracing HD DVD

. ars technica 
 
 (January 12, 2007)

. Retrieved on 2007-08-24. </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> Sony Denies Preventing Adult Content On Blu-Ray

. InformationWeek 
 
 (January 23, 2007)

. Retrieved on 2007-08-23. </ref> Blu-ray is currently exclusively backed by several adult-movie studios/publishers,<ref> PCworld.com - Japanese Porn Industry Embraces Blu-ray

.</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> Porn Factor: Why Erotic Movies Won't Decide Next Gen DVD War

 (January 31, 2007)

. Retrieved on 2007-09-10. </ref> The main reason is that many pornographic websites have movie downloads as an option, thus making the disc format less important.

Blockbuster, the largest U.S. movie rental company, offers Blu-ray exclusively in 1450 stores. Previously, the company test-marketed both competing formats at 250 stores and found that more than 70% of high definition rentals were Blu-ray discs. They continue to offer both formats at those initial 250 stores, as well as on its online rental service.<ref>Blockbuster to Expand Blu-Ray to 1,700 Stores, Blockbuster Inc. Press Releases 2007-06-18.</ref><ref> Blockbuster to favor Blu-ray high-definition discs over rival HD DVD format

   (2007)

. Retrieved on 2007-06-17. </ref><ref> Blockbuster to Expand Blu-Ray to 1,700 Stores

   (2007)

. Retrieved on 2007-06-17. </ref>

Netflix, the world's largest online movie rental service<ref> About Netflix

   (2007)

. Retrieved on 2007-12-13. </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> Netflix sees stronger loyalty for HD DVD than Blu-ray

   (2007)

. Retrieved on 2007-12-13. </ref>

On July 25 2007, Target Corporation announced they will carry Sony Blu-ray Disc stand alone players in their stores and promote them with end cap displays including exclusive Blu-ray Disc movies from Sony and Walt Disney. Sony has publicly stated that the promotion will last at least through this holiday season.<ref>http://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> Target to Promote Blu-Ray DVD Format

   (2007)

. Retrieved on 2007-07-29. </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> A high-definition fight scene in slow motion

   (2007)

. Retrieved on 2007-09-10. </ref>

On August 20 2007, Paramount Pictures, DreamWorks Pictures and DreamWorks Animation, announced they would no longer be supporting the Blu-ray Disc format. Citing HD DVD's lower consumer equipment and disc replication costs (due to its similarities to the standard DVD format), all future Paramount/Dreamworks titles will be released exclusively on HD DVD. Together, Paramount and DreamWorks are currently the 2007 box office leaders, and their first two HD DVD-exclusive titles, Shrek the Third and Transformers, are both poised to be top sellers during the 2007 holiday season.<ref>Paramount is box office leader in 2007</ref><ref> Paramount to drop Blu-ray high-def DVDs

   (2007)

. Retrieved on 2007-08-20. </ref> Movies directed by Steven Spielberg are not included in this announcement, as Spielberg controls his films.<ref> Paramount to drop Blu-ray high-def DVDs {Spielberg)

   (2007)

. Retrieved on 2007-08-20. </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> Interview with Executive Vice President of Paramount Pictures on HD DVD and Blu-Ray

   (2007)

. Retrieved on 2007-08-21. </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> Two Studios to Support HD DVD Over Rival

   (2007)

. Retrieved on 2007-08-21. </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> Katzenberg stands behind Spielberg

   (2007)

. Retrieved on 2007-09-19. </ref>

On September 24 2007 the Home Theater Specialists of America, a national buying consortium of 62 dealers and 800 installers with combined annual revenue of more than a half-billion dollars, officially endorsed Blu-ray Disc as its next-generation format of choice.<ref>Blu-ray.com - HTSA to Support Blu-ray Exclusively</ref>

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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"> DVD Forum 40th Steering Committee Meeting (Nov. 15, 2007)

.</ref> It is unknown at this time whether the final triple-layer HD DVD specification will be compatible with current players.<ref> Fulton III , Scott M.

     (2007-09-13)
   
.    Toshiba: DVD Forum Hasn't Yet Approved Final 51 GB HD DVD After All 
 (English) 
. BetaNews

. Retrieved on 2007-09-15. </ref> As of November 2007, 44% of Blu-ray titles use the 50 GB disc and 56% use the 25 GB disc<ref name="bluraystats">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"/>

In terms of audio, there are some differences. To ensure backwards compatibility with older receivers with Dolby Digital decoders, Blu-ray Disc allows conventional Dolby Digital audiotracks at 640 kbit/s and this is the primary audio track for 33% of Blu-ray titles, while it has gone unused for HD DVD titles. The newer Dolby Digital Plus is mandatory for HD DVD players at 3 Mbit/s (and is used in 90% of HD DVD titles)^{[citation needed]}, while optional for BD players with support at a bitrate of 1.736 Mbit/s for mixes that require more than 5.1 channels (has only been used on two titles).<ref name="DDplus_whitepaper">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.

As for lossless audio, 43% Blu-ray Discs have 5.1 LPCM uncompressed audio,<ref name="bluraystats"/> which is the only lossless format that is mandatory for Blu-ray players. Blu-ray Disc also has optional support for Dolby TrueHD lossless encoding of up to 8 channels of audio, and DTS-HD Master Audio, a lossless encoding of up to 8 channels of audio.<ref name="BDaudio_support">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]}

Both HD DVD and Blu-ray Disc support the 24p (traditional movie) frame rate, but technical implementations of this mode are different between the formats. Blu-ray Disc supports 24p with its native timing, while HD DVD uses 60i timing for 24p (encoded progressively, replacing missing fields with "repeat field flags"). Decoders can ignore the “flags” to output 24p.<ref> High Definition Facts

. Retrieved on 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.

Since both formats launched in the spring of 2006, an estimated 4.98 million high-definition discs have been sold, including 3.01 million in Blu-ray and 1.97 million in HD DVD through the end of September, 2007.<ref> 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>

[modifier]

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> TDK ANNOUNCES 100GB BLUE LASER DISC TECHNOLOGY

   (2005)

. Retrieved on 2007-09-27. </ref><ref> 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"> TDK ANNOUNCES BLUE LASER DISC TECHNOLOGY TO SUPPORT 200 GB CAPACITY

. TDK 
 
 (August 31 2006)

. Retrieved on 2006-11-27. </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> Yam , Marcus

     (2007-01-10)
   
.    Three HD Layers Today, Ten Tomorrow 
 (English) 
. DailyTech

. Retrieved on 2007-04-24. </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> Blu-ray/ DVD Combo ROM Disc Technology

   (2006)

. Retrieved on 2006-05-30. </ref> This hybrid disc does not appear to be ready for production and no titles have been announced that would utilize this disc structure.

Hitachi has recently Modèle:When showcased 100 GB Blu-ray Disc, which consists of four layers containing 25 GB each. Unlike TDK and Panasonic's 100 GB disc, this disc is readable on standard Blu-ray drives that are currently in circulation, and it is believed that a firmware update is the only requirement to make it readable to current players and drives.<ref>Hitachi Develops 100GB Blu-ray disc</ref> TDK has also produced a 200 GB six-layer prototype.<ref name="TDK200GB_announcement"/>

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Variants

[modifier]

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> Mini Blu-ray Disc: Guide for mini-Blu-ray-Disc Authoring

 (HTML)
 (English)

. Retrieved on 2007-08-19.

</ref> BD9 was originally proposed by Warner Home Video, as a cost-effective alternative to regular Blu-ray discs.<ref>   BD9 Licensing Further Delays The Launch of Blu-ray Burners 
. cdrinfo.com
 (2006-04-11)

. Retrieved on 2007-10-18. </ref> It is similar to HD DVD's 3x DVD

[modifier]

AVCREC

AVCREC is a standard for storing BD content on red laser DVDs using H.264/MPEG-4 AVC compression.<ref> Martyn Williams

     (2007-10-05)
   
.    New Chips Enable High-Def Recording on DVDs 
. pcworld.com

. Retrieved on 2007-10-18. </ref> It is similar to HD REC for HD DVD.

[modifier]

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.

[modifier]

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.

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