Blu-ray Vs HD-DVD
Posted by CD Team
Do we really need more capacity?
Cynics amongst us may say that it's just another way for the
computer and consumer electronics industry to sell us all
something new. While there is an element of truth in this, as
not everyone needs the additional capacity but computers,
software and applications do continue to be increasingly data
hungry.
Many users will welcome the additional amount of storage that
both formats offer, as they are getting to full capacity with
DVD and are starting to need multi-disc sets. The new formats
will be the equivalent to five and ten times the size of a DVD.
In addition to this, faster broadband speeds are allowing users
to download increasingly larger amounts of data.
High definition television will begin broadcasting throughout
Europe in 2006 and will allow consumers the best possible
television experience in both watching and recording. In the
United States over seven million digital televisions have
already been sold and Europe is not far behind. In Europe, it is
expected that broadcasting the World Cup in 2006 in high
definition and will be a major factor for many to make their
first purchase of a high definition digital television.
The fast transfer rate of blue laser disc - coupled with the
larger capacity on a disc - also makes it ideal for archive
applications, medical records and high resolution assets that
need instant access or retrieval.
First of all, let's take a quick look at the differences between
the two formats that both utilise blue laser disc recording:
Blu-ray
Blu-ray is backed by over 100 companies who are members of the
Blu-ray Disc Association (http://www.blu-raydisc.com). The key
members include; Sony, Pioneer, HP, Dell, Philips, Mitsubishi
Chemical, Walt Disney, TDK, Hitachi, 20th Century Fox and Apple.
Initial storage capacity of a Blu-ray disc will be 25GB (or 135
minutes of high definition film and two hours of bonus features
in standard definition quality) for a single layer and 50GB with
dual layer (or three hours of film and nine hours of bonus
materials). Prototypes have already been developed by TDK that
will take this to 100GB on a single side. The Blu-ray group
estimate the technology will be viable as a format standard for
10-15 years.
Similar to CD and DVD, Blu-ray discs will be available as once
only recordable (BD-R), re-writable (BD-E) and in a pre-recorded
disc format (BD-ROM). There will also be two other types of
Blu-ray disc that are contained in cartridges for specific use
in the broadcast and data archiving industries. These are called
PD and PDD respectively.
Blu-ray disc products will be launched to cover three major
application areas: 1. Desktop computer use and home video
applications. 2. Professional broadcasting. 3. Professional data
backup applications.
Blu-ray discs are manufactured using a single disc substrate,
with the recording layer very close to the disc surface. This
should result in less potential distortion, higher precision and
shorter production times and costs.
In terms of backward compatibility, it is likely that Blu-ray
disc products will play both DVD and CD formats. It is also
expected that Blu-ray PC and Mac recorders will also be able to
record onto CD and DVD discs. Sony have recently announced that
their next generation Playstation 3 console will have Blu-ray
capability.
High Density DVD
There are fewer companies in the HD-DVD Promotion Group
(http://www.hddvdprg.com), but still some significant ones none
the less. Companies include; NEC, Toshiba, Sanyo, Thomson and
Universal Pictures. The format is also supported by the DVD
Forum.
Initial storage capacity is around 15/20GB, 30/32GB and 45 GB as
a maximum with dual layer. In its present shape, the capacity is
unable to go beyond that due to the position of the recording
layer, which is further away from the disc surface.
Disc manufacturers will be able to transition over to HD-DVD
more easily as it is a similar disc structure to DVD. However,
the limited capacity could see it end up as an interim solution
and manufacturers will inevitably need to invest in Blu-ray
production lines.
Like DVD, HD-DVD disc is manufactured by bonding two surfaces
(substrates) together. It is likely that HD-DVD devices will
also be able to play DVD and CD content. Discs will be available
in a recordable (HD-DVD-R), re-writable (HD-DVD-RW) and
pre-recorded version (HD-DVD-ROM).
89 film titles will be introduced in late 2005.
Why can blue laser expand capacity?
With the same disc surface size as both CD and DVD a blue laser
disc can record and store more information by using a laser beam
with a much smaller focus than CD or DVD. This laser can record
smaller and higher density pits, enabling more data storage.
A closer look at Blu-ray
Within the Blu-ray family there are three types of discs
available, which are optimised for specific applications. The
main demand and usage will be for the standard Blu-ray product,
but there are also two other types of Blu-ray discs available
that have been specifically developed for the broadcast and data
storage market:
Professional Disc (PD)
PD has been developed specifically for the news gathering and
broadcast markets. Products are already being introduced by
Sony. These include; a recording and editing system - ENG
(Electronic News Gathering) - as well as the XDCAM series of
professional camcorders.
PD has a faster data transfer rate, 72 Mpbs as opposed to
36Mbps, than the standard Blu-ray product and is seen as a
replacement for traditional tape loaded broadcast cameras. The
disc is re-writable and contained in a cartridge for added
protection in field use. PD disc media is being manufactured by
both Sony and TDK.
Professional Disc for Data (PDD)
PDD has been developed as a replacement for traditional magneto
optical (MO) applications, such as data juke boxes for online or
archive access and storage. PDD is physically almost identical
to Professional disc (PD) and is available as re-writable and
recordable. The disc is contained in a cartridge for protection
and ease of use by the robotics in any juke box or library
system. Typical users will be medical, banking, government and
telecom businesses who need fast network access to large amounts
of data or information.
Standard Blu-ray
Standard Blu-ray will be the main Blu-ray product for mass use
in consumer recorders and players, PC drives and games consoles,
such as PlayStation 3. The disc media can be supplied 'naked'
and is not contained in a cartridge due to the application at
manufacture of a hard coat protective layer. The first
manufacturer to introduce this is TDK with their 'Durabis'
coating technology.
Dell and HP have committed to begin shipment of their high end
PC's with Blu-ray by the end of 2005. Blu-ray will have built-in
encryption and copy protection within the hardware and at the
media manufacturing level to minimise piracy and illegal copying.
Why the need for a protective layer?
One immediate reason for the protective layer is that by packing
more and more data onto the same size disc surface the recorded
data can be more susceptible to playback problems caused by
damage from handling, scratches and static. Also, in order to
obtain the highest capacity from the Blu-ray disc format and to
ensure higher precision, the recording layer in a Blu-ray disc
is manufactured closer to the disc surface than both DVD and
HD-DVD. This means that the Blu-ray disc has a far higher
capacity than other blue laser discs such as HD-DVD, but this
does mean that the disc needs to be encased in a caddy like PD
and PDD or protected by an additional coating layer. By being
able to manufacture a disc that can be used in its 'naked' form
without a caddy it will ensure a more widespread use and uptake
of the Blu-ray format. This is because the disc will be used in
a number of different drives and consumer electronic products.
Disposing of the caddy will also dramatically reduce the
manufacturing and end user unit costs.
Disc Structure Comparison
With the need to have a protective coating on a 'naked' Blu-ray
disc, TDK were the first media manufacturer to introduce a
'scratchproof' coating. This has been available for some time as
an option on their DVD product range, but recently they have
taken this technology even further with the latest version of
coating technology called 'Urbis'. The advantages of the 'Urbis'
coating mean that discs can be used without a caddy and are far
less likely to be damaged by scratches, UV light, fingerprints
and dust attracted by static.
And finally....When will it all become available?
Toshiba Corp. has announced a March 2006 commercial launch date
for the first HD-DVD player in the United States.
Blu-ray disc recorders were first launched in Japan in 2003.
Blu-ray is available in Japan in caddy format and it is expected
to be available in the US by summer 2006.
Professional Disc (PD) for broadcasting has limited availability
already. It is mainly being tested and trialled in high
definition TV projects by the major broadcast companies and
authorities.
Professional Disc for Data (PDD), which is used for archiving
and back up also has limited availability.
Both the Blu-ray group and HD-DVD group are talking together
about a single format to avoid a format clash. However, as each
party's proposal appears to be that the other one drops their
format, it seems unlikely it will lead to 'peace in our time'.
Ref: CT230106-2
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