Last Updated: 8th Jan 2007

Blu-ray: Some FACTS

I see a lot of people getting very confused about issues relating to HD-DVD and Blu-Ray and thus i'd like to introduce a few facts (with citations) which should clear a few things up.

Firstly on the Origins of Blu-Ray.

Yes it started as a Research and Development project by Sony called Ultra Density Optical - UDO (see wikipedia and citations) which then became DVR Blue when Pioneer got involved. In 2002 it became Blu-ray and the BDA (Blu-ray Disc Association) was formed by nine initial members ([1] [2]). It is this Association which decides on the specification, it is unclear on how the specification is formed (by vote etc) however we can judge a few things from the evidence on the market.

Secondly on the Blu-ray Specification

At no point in the specification does it say that Region Encoding on Blu-ray is compulsary (yes players have to support it but the discs don't have to have it). If this was a Sony thing then how come all the Sony Pictures movies I have looked at are region free (A, B and C) ([3] [4]). So it is entirely the movie studios choice on weather they region encode or not. Note that some companies are printing a region on the box but the discs are region free, for a guide see here.
Having the specification ever changing is a bad thing but unlike HD-DVD not as many items in the specification are compulsary which is good for the lower end studios who just want to put video on a disc however this causes problems for the player manufacturers. BD-Live (Profile 2) is now making a lot more things mandatory which is clearing up the specfication but essentially this is just a push towards all players having the same functionality as a PS3 (internet connection etc). I'm sure it will all settle down and the best thing to do is either buy a PS3 to play blu-ray titles on or wait a little longer for specific players to conform to the BD-Live specification.

Storage Capacity

Both formats are still experimenting on how much they can fit on a single disk. HD-DVD is currently at 30Gb with Blu-Ray at 50Gb. HD-DVD spec 2 is now at 51Gb triple layer and Tosiba declined to comment on if the first gen players could read these disks ([5]. Blu-ray on the other hand has already successfully tested a 200Gb disk, it's 8 layers so same problem exists as with HD-DVD but if Blu-ray is already moving this fast how big can it get? ([6] [7])

Codecs (Video and Audio Quality)

It is set in stone that Full HD 1080 is 1920x1080 (1:1 pixels) in resolution and this cannot change between the formats, what does change is the number of bits which can be used to encode each picture, more bits equals more detail. The max Blu-ray transfer rate is 48Mbit/s (1.5x) for both Video and Audio, a max of 40 for video. This compare to HD DVD's 36.55Mbit/s for both. So technically the picture quality should be better on Blu-ray however if you have an HD-Ready TV and not a Full HD one then you are at the mercy or the TV's built in scaler. In most TV's i've seen the scalers are rubbish with the exception of SONY,LG and Phillips (just), also Benq are a surprise with their HD-Ready projectors which are excellent in my opinion .
Due to its lacking size the recent transformers release on HD-DVD lost its Dolby True-HD soundtrack as there wasn't space for it, rather you only get the lossy soundtrack. No such problems with Blu-Ray (we hope when it comes out - 12/3/08) ([8])

Sony vs. Sony

No I am not a Sony fan boy but Blu-ray is clearly the best format. Sony have struggled over the years and I have spent a lot of years hating their Entertainment Department (responsible for PS,PS2,PSP,PS3) over the fact that they produce a machine with a lot of power and then lock the user out from accessing this power. However the PS3 sees an almost compleate turn arround. The trouble with allowing access for the users to the lower levels of the system is that the user runs the risk of turning their machine into a brick by overwriting some of the code which keeps it running and allows games to run (the OS if you like). With the PS3 Sony have spent a lot of R&D time writing a Layer which sits between the system/hardware and the game/user layer. This means that a user can now run linux on a PS3 and make use of all the power the PS3 has to offer. The only limitation of this Hypervisor is that a user cannot gain access to the graphics card, and this was not Sony's choice but rather that of the game manufacturers who think that if everyone runs linux on a PS3 they will run the free games rather than their own. Maybe if Sony reduced the price of a development licience for the PS3 then they might be able to open the hypervisor to allow users access to the graphics card like they want to (lost citation), I predict even more sales if this happens. [9].
So the hypervisor is a good thing, thank you Sony. Pity there isn't one on the PSP so i won't be buying one of them any time soon.

Apple should learn from Sony?

Now i far prefer Apple to Sony but what did they do with the iPhone/iPod Touch? Develop a great handheld PC and then lock you out of it. OK so I have a jailboken iPod Touch and now can't live without it as a PC more than an iPod, developing your own appications is easy and with a mic input I intend to get a skype varient on it somehow and make it work with my address book. However if apple had put some form of hypervisor on the device they could have probably allowed homebrewers access to the device from day one. With it jailbroken i run a small risk that i could brick it but thankfully there is a recovery mode you can put the device in which mean iTunes will reflash the device like it was at the factory (yes you loose all your music and other data on the device but that is no big deal for me).

Concluding comments

I am glad blu-ray is winning the battle and hope that the BDA can now take steps forward which don't upset the consumer. My advice would be to wait until Universal make the transition to blu-ray and then buy your players BD-Live compliant. At that point i also believe that MS will release a blu-ray drive for the XBox-360. Also Jan 15 for the possible announcement about Blu-Ray drives in the next gen iMacs and Mac-Book Pros.

David Tarrant
School of Electronics and Computer Science
University of Southampton