STONES SOUND STUDIO
THE BLU-RAY LASER
Russell Storey
- 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
Parameters
BD BD DVD DVD
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
VC-1
MPEG-2
MPEG-4 AVC
VC-1
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
Parameters
BD BD HD-DVD HD-DVD
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
VC-1
MPEG-2
MPEG-4 AVC
VC-1
MPEG-2
MPEG-4 AVC
VC-1
MPEG-2
MPEG-4 AVC
VC-1