All About Blu-ray

The winner of the high definition format has been announced. Wouldn't you want to know it better?


The format war is over, and Blu-ray has won. During the war the Sony camp was referred to as the Boys in Blue, while HD DVD were the Boys in Red. Slowly and steadily the latter became less and less of a contender, and then it happened: one of the biggest Reds (Warner) upped and left. After that HD DVD came crashing down, and the lights finally went out late last week.

So Blu-ray is our next form of optical storage, and it will become popular in India soon. Demand has to be created for the product – and this time let's please not dilly-dally, we always lag behind when it comes to tech stuff (whiny tone). We enjoyed some HD content through our PS3, and it looks insane. So it's about time.

Tech2 spoke to leading Blu-ray brands in India, like Samsung, Sharp, Sony, and asked them to send us their latest players and discs, so we can start having some high-def fun. But before that let's consider some basics, pointers, and trivia about our new friend...

Image sourced from www.blu-raydimensions.com

Why Blu
Before explaining why and how Blu-ray functions, one must know that an optical disc stores digital info (1s and 0s) in the form of bumps burnt in on the aluminum layer, in the form of concentric rings. The laser scans outwards, reflects off these bumps and flat part sequentially. The reflected rays obviously are different, and thus an optical sensor records a ‘1’ for bump and ‘0’ for no bump. (Here 1 means a higher signal level and not the number 1!). A bitstream is created and sent to the DAC (digital-analog converter).

So how does this relate to Blu-rays having more info? The answer is in the type of laser used, the numerical aperture of the lens, the distance between bumps (track pitch), its thickness etc. They are all lessened or increased accordingly. E.g. while DVDs use a red laser of 635-650nm wavelength to read information on discs, the amount of data that can be stored and read is only 4.7 GB for single layer discs.

Back in around 2003, when terrestrial digital broadcasting started, the great minds in the heads of great companies (now known as the BDA) figured out that recording about two hours of HD media on to a disc would need 22GB, something that a DVD cannot provide. Thus Blu-ray discs were born (and also HD DVD, then known as AOD).

The abbreviation is BD, and the cause for having such a name is due to the type of laser used: a blue violet laser of lesser wavelength, 405 nm. This facilitates a more accurate focus, and thus more info can be written and read from the same space. Another point is that the numerical aperture is made larger: 0.85 from 0.60 in DVDs. This facilitates a smaller diameter of the laser point (more accurate), allowing more info to be assimilated on the discs. That explains why BD discs are of the same diameter and thickness (120mm and 1.2 mm respectively) as normal discs, though the storage capacity is 25GB for single layer and 50GB for dual layer.

One cool thing of BDs is that they have a harder coating; the data is read off this itself, and thus they claim to be very resistant to dirt and other stuff. But this we will have to look at more closely before we commit ourselves...

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What Blu
BDs store full HD movies, in the form of BD-ROMs, just like DVD-ROMs. There are BD-Rs and BD-REs (rewritable) too, for burning data and stuff. The video formats read by players and stored on BDs are MPEG-2, MPEG-4 AVC (H.264). For audio there are quite a few formats: Linear PCM, Dolby Digital, Dolby Digital Plus, Dolby TrueHD, DTS Digital Surround, DTS-HD. Data transfer rate is 36 Mbps at 1x speed; this is specified by the BDA.


Image sourced from amazon.com

Interactivity has also been improved, with the addition of BD-J, or Blu-ray Disc Java, which has killer stuff like picture in picture, access to the net and more! On a serious note, copy protection standards included in BD are AACS (Advanced Access Content System), BD+, ROM-Mark and the familiar HDCP. But There are claims that AACS and BD+ have already been cracked... maybe that’s why so many high def movie are already available on the net.

Allow me to add a note on Blu-ray player profiles, as when you buy your player this will become important. There is BD 1.0, BD 1.1 and BD live 2.0. Currently profile 1.1 is being released, which requires 256 Mb of local sorage, extra audio and video decoders, but no guarantee for web-enhanced content. BD 2.0, on the other hand, has this.

Remember regions? BD has them too, though only three this time: A (green), B (orange) and C (red). India is in region C.

image sourced from www.blu-raydisc.com

Who Blu
Enough technical stuff; lets see what movies are coming our way, and who is supporting and producing Blu-ray. Sony is naturally one of the pioneers, and most Hollywood studios supported it all along: Warner, Paramount, Fox, Disney, Sony, MGM, and Lionsgate. Universal was in the HD DVD camp, though now it had better switch!

When it comes to hardware, the list is long. These are a few of the major names: Sony, Panasonic, Philips, Samsung, Pioneer, Sharp, JVC, Hitachi, Mitsubishi, TDK, Thomson, LG, Apple, HP, and Dell. Microsoft supported HD DVD, though now it had better switch as well!

Famous players available in India include the PS3 (duh), apart from Sony's BDP-S300 and BDP-S1E. Then we have LG’s BD100, Samsung’s BD-P1400 and BD-P1000 (manufacturing has stopped already, I don’t think they sold any here).


Conclusion
I guess its time for us to accept the format and enjoy HD content. Prices of individual discs have not been decided, but will initially tend to be a bit pricey. Though we can be sure that prices will fall sooner or later, as it always does in the case of any kind of electronic devices.


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