Department of Computer Science Engineering

SRK Institute of Technology

Vijayawada

Blu-ray Disc

Media type High-density optical disc

Encoding MPEG-2, H.264/MPEG-4 AVC, and VC-1

Capacity 25 GB (single layer)50 GB (dual layer)

Read mechanism 405 nm laser:1× at 36 Mbit/s2× at 72 Mbit/s4× at 144 Mbit/s6× at 216 Mbit/s12× at 432 Mbit/s

Developed byBlu-ray Disc Association

Usage Data storage,High-definition videoHigh-definition audioand PlayStation 3 games

Blu-ray Disc (also known as Blu-ray or BD) is an optical disc storage media format. Its main uses are high-definition video and data storage. The disc has the same dimensions as a standard DVD or CD

The name Blu-ray Disc is derived from the blue laser (violet coloured) 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 dual layer Blu-ray Disc can store 50 GB, almost six times the capacity of a dual layer DVD

Contents 1 History

o 1.1 Origins o 1.2 Competition from HD D

VD

2 Technical specifications o 2.1 Laser and optics o 2.2 Hard-coating technology o 2.3 Recording speed

3 Software standards o 3.1 Codecs o 3.2 Java software support

4 Player profiles 5 Backward compatibility 6 Variants

o 6.1 Mini Blu-ray Disc

Optical disc authoring v • d • e

Optical disc Optical disc image Optical disc drive Optical disc authoring Authoring software Recording technologies

oRecording modes oPacket writing

Optical media types

Laserdisc (LD), Video Single Disc (VSD) Compact Disc (CD): Red Book, 5.1 Music Disc, SACD, Photo CD, CD-R, CD-ROM, CD-RW, CD Video (CDV), Video CD (VCD), SVCD, CD+G, CD-Text, CD-ROM XA, CD-i Mini Disc (MD) (Hi-MD) DVD: DVD-R, DVD+R, DVD-R DL, DVD+R DL, DVD-RW, DVD+RW, DVD-RW DL, DVD+RW DL, DVD-RAM, DVD-D Ultra Density Optical (UDO) Universal Media Disc (UMD) HD DVD: HD DVD-R, HD DVD-RW, HD DVD-RAM, HD DVD-ROM Blu-ray Disc (BD): BD-R, BD-RE

Standards

Rainbow Books File systems

oISO 9660 Joliet Rock Ridge El Torito Apple ISO 9660 Extensions

oUniversal Disk Format (ISO 9660) (UDF) Mount Rainier

Further reading

History of optical storage media High definition optical disc format war

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

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 Disc (more specifically, BD-RE).

The first consumer devices were in stores on April 10, 2003. This device was the Sony BDZ-S77; a BD-RE recorder that was made available only in Japan. The recommended price was US$3800

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 . 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.

HD DVD had a head start in the high definition video market and Blu-ray Disc sales were slow at first. The first Blu-ray Disc 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 Disc player. At CES 2007 Warner proposed Total Hi Def which was a hybrid disc containing Blu-ray on one side and HD DVD on the other but it was never released. 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. Finally, by February 2008, Toshiba announced it was pulling its support for the HD DVD format, leaving Blu Ray as the victor in the video wars.

Physical size Single layer power Dual layer capacity

12 cm, single sided 25 GB (23.28 GiB) 50 GB (46.56 GiB)

 8 cm, single sided 7.8 GB (7.26 GiB) 15.6 GB (14.53 GiB)

Blu-ray Disc 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.

Because the Blu-ray Disc data layer is closer to the surface of the disc, compared to the DVD standard, it was at first more vulnerable to scratches . 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 spin-coated with a scratch-resistant and antistatic coating.

Drive speed

Data rateWrite time for Blu - ray Disc

(minutes)

Mbit/s

MB/s

Single Layer Dual Layer

1× 36 4.5 90 180

2× 72 9 45 90

4× 144 18 23 45

6× 216 27 15 30

8× 288 36 12 23

12×* 432 54 8 15

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.

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. . 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.

At the 2005 Java one 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.

The BD-ROM specification defines four Blu-ray Disc player profiles which includes an audio only player profile (BD-Audio) that does not require video decoding or BD-J.All three of the video based player profiles (BD-Video) are required to have a full implementation of BD-J, but with varying levels of hardware support.

Feature

BD-Audio

BD-Video

Grace Period Bonus View BD-Live

Profile 3.0 Profile 1.0 Profile 1.1 Profile 2.0

Built-in persistent memory

No 64 KB 64 KB 64 KB

Local storage capability No Optional 256 MB 1 GB

Secondary video decoder (PiP)

No Optional Mandatory Mandatory

Secondary audio decoder

No Optional Mandatory Mandatory

Virtual file system No Optional Mandatory Mandatory

Internet connection capability

No No No Mandatory

Though not compulsory the Blu-ray Disc Association recommends that Blu-ray Disc drives should be capable of reading standard DVDs and CDs for backward compatibility A few early Blu-ray Disc players released in 2006 could play DVDs but not CDs (the LG BH100, Pioneer BDP-HD1, and Sony BDP-S1) but all current Blu-ray Disc players are capable of both DVD and CD playback.

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 7.5 GB of data. It is similar in concept to the MiniDVD.Recordable (BD-R) and rewritable (BD-RE) versions of Mini Blu-ray Disc have been developed specifically for compact camcorders and other compact recording devices.