History Blu-Ray Disc Working The Technology Advantages Disadvantages On Guard To Do More With
First Generation When the CD was introduced in the early 80s, it meant anenormous leap from traditional media. Not only did it offer a significant improvement in audio quality,its primary application, but its 650 MB storage capacity alsomeant a giant leap in data storage and retrieval. For the first time, there was a universal standard forprerecorded, recordable and rewritable media, offering thebest quality and features consumers could wish for themselves,at very low costs.
Second Generation Although the CD was a very useful medium for therecording and distribution of audio and somemodest data .applications, demand for a newmedium offering higher storage capacities rose inthe 90s. These demands lead to the evolution of the DVDspecification and a five to ten fold increase incapacity. This enabled high quality, standard definition videodistribution and recording. Furthermore, theincreased capacity accommodated more demandingdata applications.
HDTV (High Definition Video) : It is also possible to capture video using inexpensivewebcams. These normally connect to a computer viaUSB. While they are much cheaper than DV cameras,webcams offer lower quality and less flexibility forediting purposes, as they do not capture video in DVformat. Digital video is available on many portable devices fromdigital stills cameras to mobile phones. This is contributing to the emergence of digital video asa standard technology used and shared by people on adaily basis.
MPEG :MPEG, the Moving Picture Experts Group, overseen by theInternational Standards Organization (ISO), developsstandards for digital video and was designed specificallyfor Video . MPEG .1 audio player .3 (MP3) compression evolved fromearly MPEG work. MPEG1 is an established, medium qualityformat supported by all players and platforms. Althoughnot the best quality it will work well on older specificationmachines. MPEG .2 is an excellent format for distributing video, asit offers high quality and smaller file sizes .Despite this,MPEG2 is becoming more common as a capture format.
Blu-ray -also known as Blu-ray Disc (BD) is thename of a next-generation optical disc format. The format was developed to enable recording,rewriting and playback of high-definition video(HD), as well as storing large amounts of data. The format offers more than five times thestorage capacity of traditional DVDs and can holdup to 25GB on a single-layer disc and 50GB on adual-layer disc.
According to the Blu-ray Disc specification, 1xspeed is defined as 36Mbps. However, as BD-ROM movies will require a54Mbps data transfer rate the minimum speedwere expecting to see is 2x (72Mbps). Blu-ray also has the potential for much higherspeeds, as a result of the larger numericalaperture (NA) adopted by Blu-ray Disc. The large NA value effectively means that Blu-raywill require less recording power and lower discrotation speed than DVD and HD-DVD to achievethe same data transfer rate.
Unlike a DVD which uses a red laser the blu ray uses ablue laser. This blue laser has a shorter wave length.The beam is more precise and can read the grooves onthe blu ray disc which are made twice as small as theones on a regular DVD.This is why the blu ray disc can hold so much data andcontains so many new features.For these reasons, the blu-ray disc will probablybecome the medium of choice for the foreseeablefuture , until something better comes along.
THE TECHNOLOGYPits: spiral groves that runs from the centerof the disc to its edge.Track pitch: it is the distance between thetwo tracks (of pits) on the surface.----------------------------------------------------------Disc store digitally encoded data in PITS.----------------------------------------------------------
THE TECHNOLOGYSo, in blu-ray disc:Pit size-- 0.15 microns (more thantwice as small as the pits on DVD).Track pitch– 0.32 micronslaser needed:-- blue-violet laser (450nm)Data transfer rate: 36Mbps
Blu-ray DensityAdvantageHigher densityenables better dataseek times.Shorter to travel forsame amount ofdata results in thefaster data seek.Better for randomaccess of data.
Technology CapacityGBSpeed AccessTimeArchiveLifePowerConsumptionSpecialRequirementsCostGBBlu-ray 50 Good V Good 50 Low No HighPlasmonUDO30 Average Good 50 Low No HighestDVD 4.7/9.4 Poor Average 50 Low No LowTAPE >800 V Good V Poor 30 Medium No LowRAID >1TB ExcellentExcellent2 High NeedsbackingupLow
Format of BDIt comes in four different formats:1. BD-ROM (read only): for reading recordedcontent.2. BD-R (recordable): for PC data storage.3. BD-RW (rewritable): for PC data storage.4. BD-RE (rewritable): for HDTV (high definitiontelevision) recording.
TYPES OF BDSINGLE LAYER:can hold data up to 25/27 GB thatmeans 2hrs of HD video or about13hrs of standard video.DOUBLE LAYER:can hold data up to 50 GB thatmeans 4.5hrs of HD video or about20hrs of standard video.
Comparison in buildingBD AND DVDBDData is placed on top of a1.1 mm thickpolycarbonate layer.Doesn’t suffer fromBIREFRINGENCE.Doesn’t suffer from DiscTilt.Hard coating is placedoutside to protect fromscratches or fingerprints.DVDData is sandwiched b/wtwo polycarbonate layers,each 0.6 mm thick.Suffer fromBIREFRINGENCE.Suffer from Disc Tilt.No such hard coating isplaced.
Huge storage capacity seriesAlthough Blu-ray cant quite fit an entire of HD-quality material on one disc, it could potentially fitan entire series of standard DVD quality stuff onone. Thats pretty good, considering the storagesavings alone. Quality support :Sony and Philips might be thestrongest backers of Blu-ray, but other majorcorporations have announced future plans tosupport the technology. Some of these includeApple, Dell and Panasonic.
Backwards compatibility :The Blu-ray Disc Association is encouragingmanufacturers to make the players fullybackwards compatible.That will allow users to both read and writeon CDs, DVDs, and, obviously, Blu-raydiscs.
That cost Movie support, thus far The competition The cost of films.
On GuardBlu-ray discs are better armedthan current DVD’s. They comeequipped with a secureencryption system – a unique IDthat protected against videopiracy and copyrightinfringement.
Do More With…More capacity , Density andPerformance.More Industry Support/ConsumerReach.More Durable.More interactive user experience.More flexible content protection.