Blu-RayTechnology review

Blu-Sky or Blu-Ray, you decide!

What is Blu-Ray?

The Blu-Ray disc (BD) has been developed to meet the demands of media rich entertainment applications and High Definition Video recording and movie distribution. BD will also likely be used for data backup, archiving and retrieval.  The BD disc looks, physically, just like a DVD or CD, however whereby a DVD can contain 9GB (dual layer) max, a dual layer BD can contain up to 50GB. The reason so much more data can be stored in this same physical space is due to the narrow wave length offered by the blue laser type used in recording Blu-Ray and HD-DVD discs. The benefits afforded by the Blu-Ray technology will allow for the development of rich media applications, interactive environments, HD movies and the birth of a wide range of further applications.

What BD formats are available?

Like a CD or DVD-ROM a BD-Rom will be a manufactured disc that is moulded and pressed and will be the distribution method of choice for HD movies, games, software etc. In addition for in-house requirements the BD-R - recordable format will be adopted for HD video recording and PC data storage and BD-RE is a re-writable format for data and video. It is also expected that a HYBRID disc featuring both Blu-Ray and DVD or CD playback will be available. At this time it is not known if a hybrid disc will be cost effective. 

What audio codecs will Blu-Ray support?

01/ Linear PCM (LPCM) - offers up to 8 channels of uncompressed audio. 02/ Dolby Digital (DD) - format used for DVDs also known as AC3, offers 5.1-channel surround sound. 03/ Dolby Digital Plus (DD+) - extension of DD, offers increased bitrates and 7.1-channel surround sound. 04/ Dolby TrueHD - extension of MLP Lossless, offers lossless encoding of up to 8 channels of audio. 05/ DTS Digital Surround - format used for DVDs, offers 5.1-channel surround sound. 06/ DTS-HD - extension of DTS, offers increased bitrates and up to 8 channels of audio. 

What is HDMI?

The High-Definition Multimedia Interface (HDMI) is a high bandwidth digital interface. HDMI will allow the connection of media devices like HD DVD players, games consoles and projectors.  

How much data can you fit on a Blu-Ray disc?

A single-layer disc can hold 25GB. A dual-layer disc can hold 50GB.To ensure that the Blu-Ray Disc format is easily extendable (future-proof) it also includes support for multi-layer discs, which should allow the storage capacity to be increased to 100GB-200GB (25GB per layer) in the future simply by adding more layers to the discs. Over 9 hours of high-definition (HD) video can be stored on a 50GB disc. About 23 hours of standard-definition (SD) video can fit on a 50GB disc. 

What is the BD-R/RE AV format?

BD-R/RE Audio Visual (BD-R/RE AV) is a format designed to record and play back full quality high (HD) and standard (SD) definition digital television broadcasts on BD-R (recordable) and BD-RE (rewritable). The BD-AV will allow consumers for example to use HD (or SD) video content in order to “author” a BD disc that will be playable in a standalone BD-player. SD material can be captured from analog sources and direct transfers from DV camcorders, allowing up to 2 hours of HD material to be stored on a 25 GB single-layer. 

What is the BD-ROM AV format?

BD-ROM Audio Visual (BD-ROM AV) is an application format designed to meet the requirements of the film industry for distributing high definition (HD) commercial movies on BD-ROM (prerecorded). It combines the features offered by DVD in addition to support for HD video, multi channel audio and enhanced interactive and network features. 

What video codecs will Blu-Ray support?

01/ MPEG-2 - enhanced for HD, also used for playback of DVDs and HDTV recordings. 02/ MPEG-4 AVC - part of the MPEG-4 standard also known as H.264 (High Profile and Main Profile). 03/ SMPTE VC-1 - standard based on Microsoft’s Windows Media Video (WMV) technology. 

Will Blu-Ray support mandatory managed copy?

Mandatory managed copy (MMC) will be part of the Blu-Ray format, allowing consumers to make legal copies of their Blu-Ray movies for local use. This function is subject to hardware support from manufacturers. 

How effective is the BD Copy Protection?

BD movie discs use Advanced Access Content System (AACS) to help prevent un-authorised copying, however the effectiveness is jeopardised since most TV’s or monitors do not support HDCP. Since there is no high bandwidth copyright protection in place copies can be made via analog connections. 

Is Blu-Ray the same thing as HD-DVD?

HD-DVD is a competing next-generation optical disc format developed by Toshiba and NEC. Although the format uses the same principle of blue laser technology it is quite different from Blu-Ray. 

Are BD devices compatible with CDs and DVDs?

The BD specifications do not dictate backwards compatability. It is up to manufacturers to consider this requirement and build in compatability as required.

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