BlueRay

Blueray is a format initially championed and developed by Sony, but now through the Blue Ray Disc Association, is widely supported through it's consortium of partners. BlueRay is similar to HD-DVD in the fact it uses a similar 405nm blue-light laser. Blueray however uses a larger numerical aperture of .85 and a higher data transfer rate of 54.0 Mbit/s which allows the media to achieve higher data densities. In it's current standard guise, this is 25GB per layer, for 50GB capacity for a standard dual layer BD-ROM disc. Because of this however, BlueRay discs store their information a little closer to the surface of media, and are thus more prone to degradation from dirt, fingerprints,  and scratches. Because of this BD-ROM discs are mandated to have a much tougher (and more expensive to manufacture) outer coating to ward off disc damage.

When you get past the physical media differences, it's as we indicated before in the HD-DVD section with much of the remaining technical details quite similar. Blueray supports MPEG2, the old standard video codec used in DVD movies as well as the newer MPEG4 derivatives, AVC, VC-1, and h.264. Currently most Blueray content is encoded with the VC-1 implementation of MPEG4 as is the case with HD-DVD. Also, audio codec choices are significantly varied, with support for Linear PCM, DTS HD, Dolby Digital, Dolby Digital Plus, and MPEG Layer 3 audio, again like HD-DVD.

Actual playback times at standard definition (480p) resolutions are much higher than HD-DVD due to the greater amount of physical storage space, 23 hours. Likewise for high definition (1080p) you can store up to 9 hours of content. Though BlueRay has no specific support for playing back HD encoded DVD-ROM like HD-DVD does, it does at least mandate backwards compatibility for reading standard DVD's. One area unique to BlueRay is it's inclusion of the Java language for the creation of interactive menu and navigation systems for BD discs and players, a much more elegant solution than merely relying on pre-rendered video sequences, as is the case with HD-DVD and standard DVD.

BlueRay relies on AACS or Advanced Access Content System copy protection, the same as HD-DVD. The BlueRay spec though goes one step further with a system known as BD+, which allows for reassigning new sets of encryption keys over time as older ones become known. BlueRay also uses a similar media watermarking system, known as ROM-Mark, for detection of copied media. Things are also more or less identical in BlueRay's implementation of the Image Constraint Token or ICT Flag when it comes to punishing users for not having HDCP compliant displays. Currently most of the studio's releasing BlueRay discs are not widely using the ICT Flag, which would otherwise force down sampling of  high definition content to 960x540 on non HDCP compliant displays. At least for now.

Industry support for BlueRay is quite broad with Sony championing the format. Sony, Apple, Dell, Hitachi, HP and others on the hardware side of the equation are members of the BlueRay Consortium. Similarly big studios like Universal, Warner, Paramount, MGM, and Disney are supporters of the format. It's no shock that the first available BD-ROM player came from Sony, in the guise of their Sony BDP-S1. Currently, the cheapest way to get into BlueRay is via Sony's new PS3 console, which comes with a BD-ROM drive built in. Since the PS3's launch, it appears BlueRay has caught up to HD-DVD significantly in players available and sold, as well as "attach rate" (the number of discs sold per player).

Now that we have an idea of most of the technical issues involved, it's time to delve into a little bit of speculation and guesswork when it comes to evaluating the potential "success" of the formats themselves.