Blue Ray Disc Information

Blu-ray Disc recordable

saad2992 — Tue, 18 Mar 2008 02:42:16 +0000

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 January 2008, BD-R/RE drives up to 6x speed are available from retailers for about US$450,and 4x single-layer BD-R discs, with a capacity of 25 GB, can be found for around US$12. The theoretical maximum speed 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.Since September 2007, BD-RE was also available in the smaller 8 cm Mini Blu-ray Disc diameter size.

Variants

saad2992 — Tue, 18 Mar 2008 02:41:40 +0000

Mini Blu-ray Disc:-
The Mini Blu-ray Disc (also, Mini-BD and Mini Blu-ray) is a compact 8cm (~3in) diameter variant of the Blu-ray Disc that can store approximately 7.5GB of data. It is similar in concept to the MiniDVD.Recordable (BD-R) and rewriteable (BD-RE) versions of Mini Blu-ray Disc have been developed specifically for compact camcorders and other compact recording devices.
BD9 / BD5 Blu-ray Disc:-
BD9 and BD5 are lower capacity variants of the Blu-ray Disc that contain Blu-ray compatible video and audio streams contained on a conventional DVD (650 nm wavelength / red laser) optical disc. Such discs offer the use of the same advanced compression technologies available to Blu-ray discs (including MPEG4-AVC/H.264, SMPTE-421M/VC-1 and MPEG2) while utilizing lower cost legacy media. BD9 utilizes a standard 8152MB DVD9 dual-layer disc while BD5 utilizes a standard 4489MB DVD5 single-layer disc.Given that Blu-ray Discs are assumed to have a minimum transfer rate of 30.24 Mbit/s, BD9/BD5 discs must be spun at a high rate of speed, equivalent to a 3× DVD drive speed or greater.BD9 and BD5 discs can be authored using home computers for private showing using standard DVD±R recorders. AACS digital rights management is optional.The BD9 format was originally proposed by Warner Home Video, as a cost-effective alternative to regular Blu-ray Discs.It was adopted as part of the BD-ROM basic format, file system and AV specifications.BD9 is similar to HD DVD’s 3x DVD.
AVCREC:-
AVCREC is an official lower capacity variant of the Blu-ray Disc used for storing Blu-ray Disc compatible content on conventional DVD discs. It is being promoted for use in camcorders, distribution of short HD broadcast content and other cost-sensitive distribution needs. It is similar to HD REC for HD DVD.Note that AVCREC is not the same as AVCHD content stored on DVD. The latter is a media independent format that originated prior to the release of Blu-ray Disc.

Ongoing development

saad2992 — Fri, 07 Mar 2008 11:04:14 +0000

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 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.

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 150 GB 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.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. This hybrid disc does not appear to be ready for production and no titles have been announced that would utilize this disc structure.In January 2007, Hitachi showcased a 100 GB Blu-ray Disc, which consists of four layers containing 25 GB each.Unlike TDK and Panasonic’s 100 GB discs, they claim 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.

Digital rights management (DRM)

saad2992 — Fri, 07 Mar 2008 11:02:25 +0000

The Blu-ray Disc format employs several layers of Digital rights management.Advanced Access Content System (AACS) is a standard for content distribution and digital rights management. It is developed by AS 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 key.BD+ was developed by Cryptography Research Inc. and is based on their concept of Self-Protecting Digital Content.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:

* 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.The first titles using BD+ were released in October the same year. Players from Samsung and LG had problems playing back those titles until the manufacturers updated their firmware, but this problem was later identified as being related to BD-Java use, not BD+.BD+ was reported to have been circumvented by the developers of the program AnyDVD as of version 6.1.9.6 beta. However, such claims were found to be erroneous.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.

Java software support

saad2992 — Fri, 07 Mar 2008 08:59:32 +0000

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.

Codecs

saad2992 — Fri, 07 Mar 2008 08:58:38 +0000

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 the mandatory schemes for the primary soundtrack. A secondary audiotrack, if present, may use any of the mandatory or optional codecs.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 30.24 Mbit/s in HD DVD movies for audio and video data.

Hard-coating technology

saad2992 — Fri, 07 Mar 2008 08:44:08 +0000

Because the Blu-ray data layer is closer to the surface of the disc, 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 cartridges 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’s recordable and rewritable Blu-ray Disc discs use their own proprietary hard-coat technology called ScratchGuard.

Ending of the format war

saad2992 — Fri, 07 Mar 2008 08:37:43 +0000

In January 2008, a day before CES 2008, Warner Brothers, the only major studio who was releasing movies in both HDDVD and BluRay format, announced they will only release in BluRay after May 2008. This effectively included other studios which come under the Warner umbrella, i.e New Line Cinema and HBO as well. This led to a chain reaction in the industry, including major US retailers such as WalMart dropping HDDVD in their stores. A major European retailer Woolworths dropped HDDVD from their inventory. Netflix, the major online DVD rental site said they will no longer stock new HDDVDs. Following these new developments, on 19 February 2008, Toshiba announced it was ending production of HD DVD devices , allowing Blu-ray Disc to become the industry standard for high-density optical disks. Universal Studios, the sole major movie studio to back HD-DVD since inception, shortly after Toshiba’s announcement said, “while Universal values the close partnership we have shared with Toshiba, it is time to turn our focus to releasing new and catalog titles on Blu-ray.”Paramount Studios, which started releasing movies only in HDDVD format during late 2007, also said they will start releasing in BluRay. With this, all major Hollywood studios are now supporting BluRay.”

Launch and Sales developments

saad2992 — Fri, 07 Mar 2008 08:36:46 +0000

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.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.The first movies using dual layer discs (50 GB) were introduced in October 2006.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.This changed when PlayStation 3 launched, since every PS3 unit also functioned as a Blu-ray player. By January 2007, Blu-ray discs had outsold HD DVDs,and during the first three quarters of 2007, BD outsold HD DVDs by about two to one.

Blu-ray Disc format finalized

saad2992 — Fri, 07 Mar 2008 08:26:23 +0000

The Blu-ray Disc physical specifications were finished in 2004.In January 2005, TDK announced that they had developed a hard coating polymer for Blu-ray Discs.The cartridges, no longer necessary, were scrapped. The BD-ROM specifications were finalized in early 2006.AACS LA, a consortium founded in 2004,had been developing the DRM platform that could be used to securely distribute movies to consumers. However, the final AACS standard was delayed, and then delayed again when an important member of the Blu-ray Disc group voiced concerns.[At the request of the initial hardware manufacturers, including Toshiba, Pioneer and Samsung, an interim standard was published which did not include some features, like managed copy.