All about DVD Part 3: Blu-Ray and HD-DVD
On the first glance, DVDs have just finished becoming common and
are the best option available. But developers do not agree,
trying to invent new needs for poor users. This time HDTV
(High Definition Television)is considered to be the new
technology that no video lover can live without. Compared with
common TV, HDVT has several times bigger screen
resolution and is technically able to display much more fine
details. Of course, all this is available on special HDTV-ready
TV sets only. Another problem is concerned with storage of
HDTV video, as even the DVD-18 standard with its largest
capacity among DVD swill not be able to store several hours of
HDTV quality video.
Fortunately, developers of DVD have mastered so-called "blue"
laser, which wavelength is only 405nm. By using this laser it
becomes possible to achieve much higher data density compared
with DVD disks that use "red" laser with wavelength of 650nm.
This new technology would allow to store up to 200 GB of data on
a multi-layered disk.
Unfortunately, the new formats war has sparked even before the
end of the development of actual devices, with the same old
players on the field: Sony and
Philips with Blue Ray
standard and Toshiba, NEC and Sanyo with HD-DVD format.
HD-DVD
HD-DVD (High Definition DVD), as clearly visible from its
name, is official heirto the DVD format, approved by DVDForum. This format is 100%
compatible with both CD and DVD, not only from home user
perspective but also on manufacturing level. Manufacturing
HD-DVD will not require huge investments in new
equipment, and this was the reason why such big companies as Inteland Microsoft decided to support
it. Microsoft, for
example, promised full support of HD-DVD in its new
Windows Vista that should be released next year.
One single layer of HD-DVD disk has the same thickness as
DVD layer (0.6mm) and can contain up to15 GB of data. This means
that HD-DVD won't have any troubles supporting
dual-layered and double-sided disks, besides; Toshiba announced
the development of triple-layer HD-DVD, where one side of
the disk would contain 45GB. The theoretical capacity limit for
HD-DVD is, therefore, 90GB.
Along with MPEG-2, compression technologies such as MPEG-4 and
Video Codec 1 (VC1, format based on Windows Media 9) will be
used. HD-DVD Video disk swill have more advanced
capabilities for interactivity than DVD-Videodisks. For example,
it would be possible to play several different video clips in
picture-in-picture mode, and it also would be possible to
connect more than one remote control to the HD-DVD player
in order to play videogames together. Internet access will also
be included in all HD-DVD devices, so it would be
possible to follow web-links straight from disk menu or to
download new soundtrack or subtitles from the net. And these are
only few of new features.
Internet connectivity is also demanded by the new encryption for
HD-DVD and Blue Ray disks - AACS(Advanced Access
Content System). Each disk is validated with online database
prior to playing. If the disk appears to be counterfeit, the
playing device will be locked. It is not clear, however, what to
do in countries where Internet is not available in every
household. There is certain possibility, though, that Blue Ray
and HD-DVD will become luxury, just as SACD and DVD-Audio
before them. Alternatively, it could become common only in
distant future, when Internet will be available even in African
deserts.
Despite stricter copy protection, manufacturers most probably
will not add regional codes to HD-DVD as it provides more
troubles than benefits, and although movie production companies
still insist on keeping regional protection, most of DVD-Forum
officials are against it.
Recordable HD-DVD are named in the same way as DVD:
HD-DVD-R (recordable) and HD-DVD-RW (rewritable).
Blue Ray Disc
Blue Ray Disc (BD) standard is promoted by Blue Ray Disc Association
(BDA), an organization formed for this particular
purpose. By throwing away the compatibility with CD and DVD it
became possible to achieve much higher capacity than HD-DVD. One
layer of BD can contain23.3GB, 25GB or 27GB of data. As
the layer thickness is much lower than the one of DVD and is
only 0.1 mm (compared to 0.6mm for HD-DVD), it ispossible to
manufacture multilayered disks with high number of layers.The
theoretical capacity of BlueRay disk is 200GB.
Unfortunately, manufacturing of these disks will require
purchase of brand new equipment.
Initially Blue Ray disks could only be used with
cartridges (same as DVD-RAM) because of poor protection from
physical damage, but now this issue seems to be solved and
plastic cartridges are not needed anymore. Codecs used to store
video in Blue Ray standard are the same as the ones used for
HD-DVD(Mpeg-2, Mpeg-4 and VC1). This is not surprising as Blue
Ray and HD-DVD were designed to store existing formats of video,
while in case with DVD new codecs were developed specifically to
cater for new type of disks.
Blue-Ray disks have more advanced menu compared to DVD-Video.
The menu offers more functionality and is generally written in
Java language. Blue Ray devices require Internet
connection just as HD-DVD ones do, and Blue-Ray disk menu
also supports integration with Internet. As it was said before,
Internet will be also required for AACS protection. Apart
from AACS, Blue Ray also implements two unique
protection measures - ROM-Mark and BD+Rom-Mark.
ROM-Mark is a special hidden label on the disk, similar
to watermark in DVD-Audio. It can not be copied and disks
couldn't be played without it. BD+ technology is designed
to check whether or not Blue Ray player was hacked, and
in case if it is true, it will download new firmware from
Internet in order to fix in appropriate modifications.
Blue Ray disks naming is slightly different from usual.
Read-only disks are called BD-ROM, recordable are called
BD-R and rewritable are named BD-RE (Rewritable).
Future Perspectives
Only time will tell if one particular format will prevail or if
there will be a complete mess with formats again. At the moment
both alliances are trying to do something to attract customers
and manufacturers. Blue Ray is leading at the moment. Due
to the more advanced copy protection and higher capacity Blue Ray Association
managed to attract most of film production companies. Another
plus for Blue Ray lies in the fact that PlayStation 3will use
Blue Ray disks and therefore will be able to play Blue
Ray Video disks too. Apple
Computersis also going to include Blue Ray drives in
its computer packages. Apart from all of this, Blue Ray
devices appeared on the market much earlier than the
competitors.
HD-DVD may attract users because of its back
compatibility with previous formats. Besides, manufacturers will
not have to spend much effort and money to make disks of this
type. HD-DVD is also supported by some major studios,
such as New Line
Cinema, Paramount
Pictures, Universal
Studios и Warner Bros
(however some of them support both formats) and IT giants such
as Intel and Microsoft.
Summary
Unfortunately, multi format drive that could support both
Blue Ray and HD-DVD will be very expensive and
difficult to manufacture due to large differences in technology
behind new standards. However, several companies already have
announced the development of such devices. If they succeed, we
can hope that new formats will be widely accepted very soon. If
not, there is a certain chance that HD-DVD and Blue
Ray will share the destiny of DVD-Audio and
SACD and only few chosen ones will use them. Besides, it
is still not clear whether or not consumers actually need high
definition image. And if you take into account that many people
often transform DVD into smaller AVI files and use them for
viewing at PC, it becomes possible to assume that HD-DVD
and Blue Ray manufacturers will have a hard time
promoting their formats. Video-on-Demand also does not add
popularity to them.
So, which format will prevail still remains a mystery.