Russell Storey

some information updates from  sept2004
  1. Introduction

    1.1 What is Blu-ray?

    Blu-ray, also known as Blu-ray Disc (BD) is the name of a next-generation optical disc format. The format was developed to enable recording, rewriting and playback of high-definition television (HDTV). The format is also likely to become a standard for PC data storage and high-definition movies in the future.

    1.2 Why the name Blu-ray?

    The name Blu-ray is derived from the underlying technology, which utilizes a blue-violet laser to read and write data. The name is a combination of "Blue" and optical ray "Ray". According to the Blu-ray Disc Association, the spelling of "Blu-ray" is not a mistake. The character "e" is intentionally left out because a daily-used term can't be registered as a trademark.

    1.3 Who developed Blu-ray? UPDATED

    The format was developed by the Blu-ray Disc Founders (BDF), a group of eleven leading consumer electronics companies:

    Hitachi, Ltd.
    LG Electronics Inc.
    Matsushita Electric Industrial Co., Ltd.
    Mitsubishi Electric Corporation
    Pioneer Corporation
    Royal Philips Electronics
    Samsung Electronics Co., Ltd.
    Sharp Corporation
    Sony Corporation
    TDK Corporation
    Thomson Multimedia

    In January 2004, the world's two largest PC manufacturers, HP and Dell, were accepted into the group to help further develop the format for PC data storage. The group is currently re-incorporating itself into the Blu-ray Disc Association (BDA), which will be open to companies that wish to help develop, promote and establish Blu-ray as an industry standard for high-definition optical storage.

    1.4 What Blu-ray formats are planned?

    As with conventional CDs and DVDs, Blu-ray plans to provide a wide range of formats including ROM/R/RW. The following formats are part of the Blu-ray Disc specification v1.0:

    BD-ROM, which is a read-only format developed for pre-recorded content.
    BD-R, which is a recordable format developed for PC data storage.
    BD-RW, which is a rewritable format developed for PC data storage.
    BD-RE, which is a rewritable format developed for HDTV recording.

    1.5 How much data can you fit on a Blu-ray Disc?

    A single-layer disc can fit 23.3GB, 25GB or 27GB.
    A dual-layer disc can fit 46.6GB, 50GB or 54GB.

    There's also research going on to develop 100GB quad-layer discs (25GB per layer).

    1.6 How much video can you record on a Blu-ray Disc?

    Over 2 hours of high-definition television (HDTV) on a 25GB disc.
    About 13 hours of standard-definition television (SDTV) on a 25GB disc.

    1.7 How fast can you record a Blu-ray Disc?

    According to the Blu-ray Disc v1.0 specification, 1x speed will require a 36Mbps data transfer rate, which means it will take about 1 hour and 33 minutes to record 25GB. The Blu-ray Disc Association are currently working on the v2.0 specification, which will support 2x speed to cut the time it takes to copy content from one disc to another in half. In the future, the data transfer rate is expected to be raised to 8x or more.

    1.8 What video codecs will Blu-ray support? UPDATED

    The Blu-ray Disc Association (BDA) is still in the process of finalizing the BD-ROM specification, but they have stated that MPEG-4 AVC High Profile (previously called FRExt) and Microsoft's VC-1 video codec (the proposed SMPTE standard based on WMV9) will be mandatory. They will also include MPEG-2 support for playback of recorded HDTV content and DVDs. The BDA expects the BD-ROM specification to be finished by the end of the year. Please note that this simply means that all Blu-ray players and recorders will have to support playback of these video codecs, it will still be up to the movie studios to decide which video codec(s) they use for their releases.

    1.9 What audio codecs will Blu-ray support? UPDATED

    The Blu-ray Disc Association (BDA) still hasn't made a final decision about what audio codecs will be included in the specification, but according to the BDF technical spokesman Richard Doherty, the included audio codecs should offer a significant improvement over the audio formats supported by the current DVD spec. They are currently looking into advanced audio codecs, including lossless codecs.

    1.10 Will Blu-ray Discs require a cartridge?

    No, the Blu-ray Disc Association (BDA) has successfully developed a new hard-coating technology that should make the discs even more resistant to scratches and fingerprints than existing DVDs (without requiring a cartridge). By making the cartridge optional manufacturers will be able to downsize drives for PC usage and lower their media production costs.

    1.11 When will I be able to buy a Blu-ray Disc recorder?

    You'll probably have to wait until 2005-2006 for Blu-ray recorders to become commonly available. The driving force behind the development of Blu-ray Disc recorders is the need to record HDTV programming and currently the only country where HDTV is well established is Japan. There's still only two different Blu-ray Disc recorders available to consumers in Japan (the Sony BDZ-S77 and Panasonic DMR-E700BD), but as you can see in our Blu-ray Recorders section, most well-known consumer electronics companies have their own prototype Blu-ray Disc recorder in development, so we expect to see more Blu-ray recorders on the Japanese market during 2004.

    According to Sony of America's senior vice president Mike Fidler, products based on the Blu-ray Disc format are not likely to be available in the United States until late 2005 or early 2006. However, LG Electronics has stated that they have plans to introduce a Blu-ray Disc recorder in the United States in the third quarter of 2004.

    1.12 What will a Blu-ray Disc recorder cost?

    As with any new technology, the first generation of Blu-ray Disc recorders will be very expensive, but the prices have already begun falling. The Sony BDZ-S77 is currently priced at 224,000 yen ($2,049), while the Panasonic DMR-E700BD is priced at 214,000 yen ($1,957). The discs required to record high-definition video are priced at about 2,700 yen ($25) per disc. The explanation for the high retail price is that the recorder is targetted for businesses and enthusiasts rather than consumers.

    According to the Blu-ray Disc Association, the overall cost of manufacturing a Blu-ray Disc will in the end be no more expensive than producing a DVD. The reduced injection molding costs offset the additional cost of applying the cover layer and hard coat, while the techniques used for applying the recording layer remain the same. As soon as manufacturers start mass production of blue-laser components, which is expected to begin in 2004, the production costs should fall and eventually be within 10% of DVDs.

    Current technology

    2.1 Will Blu-ray replace VHS?

    Yes, that's the expectation. The Blu-ray Disc recorder represents a major leap forward in video recording technology as it enables recording of high-definition television (HDTV). It also offers a lot of new innovative features not possible with a traditional VCR:

    Random access, instantly jump to any spot on the disc

    Searching, quickly browse and preview recorded programs in real-time

    Create playlists, change the order of recorded programs and edit recorded video

    Automatically find an empty space to avoid recording over programs

    Simultaneous recording and playback of video (enables Time slip/Chasing playback)

    Enhanced interactivity, enables more advanced programs and games

    Broadband enabled, access web content, download subtitles and extras

    Improved picture, ability to record high-definition television (HDTV)

    Improved sound, ability to record surround sound (Dolby Digital, DTS, etc)

    2.2 Will Blu-ray replace DVD?

    It's still too early to say. In the end it's up to the movie studios to decide in what format they release their movies, so they will play a big part in the decision of which format becomes the standard for high-definition movies and the successor to DVD. However, they are still earning good money from sales of DVDs, so they aren't in a hurry to adopt a new format for movies. They will probably hold off on introducing movies in high-definition until 2006-2007, as they speculate that the DVD market will continue to grow until then. The only movie studio to publically support any blue-laser based format so far is Columbia TriStar, who has stated that they will release movies in the Blu-ray format.

    2.3 What's the difference between Blu-ray and DVD? UPDATED

    Recording capacity 25GB 50GB 4.7GB 9.4GB
    Number of layers single-layer dual-layer single-layer dual-layer
    Laser wavelength 405nm 405nm 650nm 650nm
    Numerical aperture (NA) 0.85 0.85 0.60 0.60
    Protection layer 0.1mm 0.1mm 0.6mm 0.6mm
    Data transfer rate 36Mbps 36Mbps 11.08Mbps 11.08Mbps
    Video compression MPEG-2
    MPEG-4 AVC
    MPEG-4 AVC
    MPEG-2 MPEG-2

    2.4 Will Blu-ray support playback of DVDs?

    Yes, several leading drive manufacturers have already demonstrated drives for consumer products such as video recorders that can read and write DVD and Blu-ray Discs, so you don't have to worry about your existing DVD collection becoming obsolete. Although there is no requirement for Blu-ray recorders to be backwards compatible with DVD, the format is far too popular to not be supported. With the vast amount of Blu-ray recorders that will be coming out, this will be an important feature for consumers.

    2.5 What about Blu-ray for PCs?

    There are plans for BD-ROM (read-only), BD-R (recordable) and BD-RW (rewritable) drives for PCs, and with the support of the worlds two largest PC manufacturers, HP and Dell, it's very likely that the technology will be adopted as the next-generation optical disc format for PC data storage and replace technologies such as DVD-R, DVD+R, DVD-RW, DVD+RW and DVD-RAM.

    Next-generation technology

    3.1 Is Blu-ray the same thing as HD-DVD?

    No, HD-DVD, also known as AOD (Advanced Optical Disc) is the name of a competing next-generation optical disc format developed by Toshiba and NEC. The format is similar to Blu-ray and also utilizes blue-laser technology to achieve a higher storage capacity. The rewritable versions of the discs will be able to hold 20GB on a single-layer disc and 32GB on a dual-layer disc, while the read-only discs only will be able to hold 15GB on a single-layer disc and 30GB on a dual-layer disc. The read-only version of the format has been approved by the DVD Forum as the successor to the current DVD technology.

    3.2 What's the difference between Blu-ray and HD-DVD? UPDATED

    Recording capacity 25GB 50GB 20GB 32GB
    Number of layers single-layer dual-layer single-layer dual-layer
    Laser wavelength 405nm 405nm 405nm 405nm
    Numerical aperture (NA) 0.85 0.85 0.65 0.65
    Protection layer 0.1mm 0.1mm 0.6mm 0.6mm
    Data transfer rate 36Mbps 36Mbps 36Mbps 36Mbps
    Video compression MPEG-2
    MPEG-4 AVC
    MPEG-4 AVC
    MPEG-4 AVC
    MPEG-4 AVC