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2003-2004
DVD-Video
is the best thing to come along since the digital audio CD
format. DVD provides a stunningly detailed picture and surround sound audio. With
the DVD-Video format’s breakthrough in digital video and audio
technology, home theater enthusiasts and movie collectors have
a format that finally meets their needs. And with
DVD-Video player prices low, DVD-Video is now affordable
to most everyday consumers. The DVD-Video format is
seeing phenomenal success world wide, with an adoption rate
unequalled by previous technology introductions.
The next best thing to come along ... DVD recorders. The ability to record TV
programs and home videos onto a recordable DVD disc would allow DVD
technology to fully supplant the home video (VHS)
format. If you
are interested in using DVD recorders to time shift TV
programs, to transfer home videos from camcorder video tapes
to more durable recordable DVD discs, to archive and share
home videos on the robust recordable DVD discs, keep
reading...
Three Recordable
DVD Formats
One big factor playing into the phenomenal
success of the DVD-Video format is its single unified format. With the success of the DVD-Video
format, you would think that the consumer electronics industry
learned something about launching a new product with a single
format. No, unfortunately not. To our dismay,
there are no less than three DVD recordable
formats! Equally appalling is that each format is
not compatible with the other two. The formats are DVD-R/RW,
DVD+R/RW,
and DVD-RAM.
If you want to invest in a DVD recorder today, you will need
to know what you’re getting into.
DVD-R/RW Format
 The DVD-R/RW format consists of
the write-once DVD-R and the rewritable DVD-RW formats.
“DVD-R/RW” is shorthand for “DVD-R
and DVD-RW”.
Write-once means you can only record to
the disc segment once, like CD-R discs. You can never erase the
recording, and you can never record over an area that has
already been recorded. Rewritable means new
information can be re-recorded over a previously recorded
segment, making the entire disc reusable for repeated
recordings (much like a VHS tape). Of course, the
previous recorded segment is erased when you re-record over
it.
The DVD-R variant of the DVD-R/RW format was
the first to be defined. Making its debut in late 1997,
it quickly followed the DVD-Video format’s introduction in the
second quarter of 1997. DVD-R is backwards compatible
with most existing DVD-Video players and computer DVD-ROM
drives, perhaps partly due to its early definition.
Backwards
compatibility ensures that the DVD-R disc will be
readable by existing DVD-Video players and computer DVD-ROM
drives. This allows you to record content to a DVD-R
disc and playback on any ordinary DVD-Video player or a
computer DVD-ROM drive, whether the unit belongs to you, a
family member, or a friend.
 DVD-R comes in two
flavors: DVD-R for Authoring (a.k.a. “DVD-R Authoring”)
and DVD-R for General (a.k.a. “DVD-R General”).
DVD-R for Authoring is for the commercial world, where its
primary application is DVD authoring (or content
generation). DVD-R for General, as the name implies, is
for consumer and home use. When you buy a DVD-R disc, be
sure to buy the DVD-R General format. DVD-R for
Authoring discs will not work, as they are designed for DVD-R
Authoring devices which employ slightly shorter 625-nm
wavelength lasers. Early DVD-R discs have two
capacities, 3.95 GB or 4.7 GB. Nowadays, all DVD-R discs
are made with 4.7 GB capacity.
Recording works on the principle of a red
laser permanently transforming a dye-recording layer on the
DVD-R disc, similar to how CD-R recording (or “burning”)
works. This permanent transformation of the media is
characteristic of a write-once format. DVD-R has an
expected lifespan of about 100 years. Like the DVD-Video
format, the video information is written as a single track,
starting from the inner-most portion of the disc and spiraling
out to the outer edge.
Since it achieves a reported better than 90%
backwards compatibility with existing DVD-Video players and
computer DVD-ROM drives, DVD-R is ideal for archiving and
distributing home videos. There’s a high likelihood that
the DVD-R you make would be viewable on any DVD-Video player
and computer DVD-ROM drive, but there is no 100%
guarantee. Obviously 100% compatibility would be
expected by everyday consumers, but it is not possible in
today’s world of recordable DVD formats.
The rewritable version of DVD-R/RW format is
the DVD-RW variant, formally known as “DVD
Re-Recordable”. Introduced in late 1999, DVD-RW supports
1,000 rewrite cycles with a 4.7 GB data capacity. It
uses phase-change technology, allowing video and data to be
recorded incrementally as a series of sequential recording
sessions. The format also allows for a single
start-to-finish disc-at-once recording session, when the disc
is finalized at the end. Finalization is a
process that essentially "completes" the recording process and
makes the disc readable by playback-only devices. DVD-RW
has a backwards compatibility rate of roughly
65% with existing DVD-Video players and DVD-ROM
drives. Its expected shelf life is at least 30 years.
DVD-R is more appropriate for home video distribution and
archival purposes, while the rewritable DVD-RW format is
better suited for TV program time shifting, when you would
want to re-record over TV programs that you have viewed (just
like you would reuse a VHS tape by record over a previously
recorded program).
The DVD-R/RW format was initially championed
by Pioneer Electronics, and is supported by the DVD Forum (the
same body of industry representation that is behind the
successful DVD-Video format). Today, DVD-R/RW is
supported by the likes of Pioneer, Sony, Toshiba, Apple
Computer, and Compaq Computer. DVD-RW includes
provisions for content protection via the Content Protection
for Recordable Media (CPRM).
The current crop of standalone DVD-R/RW
recorders available today includes Pioneer, Sharp,
and Sony as well as others.
Pioneer
Elite DVR-7000 DVD-R/RW recorder
DVD-R/RW drives for computers are also
available. Together with a DVD authoring software
package, you can transfer the digital video footage from your
camcorder to your computer’s hard drive, edit in a non-linear
fashion (i.e., random cut and paste of video segments), and
record the final sequence to a DVD-R or DVD-RW disc for
playback on most any DVD-Video player and computer DVD-ROM
drive. You can even create professional looking DVD
menus and chapter selection, just like commercial DVD-Video
movie titles.
DVD+R/RW Format
Like the previous format, the
DVD+R/RW format consists of the write-once DVD+R and the rewritable
DVD+RW variants. DVD+RW officially stands for
“DVD+ReWritable Video”. Note the previous format had a
dash (“-”), while this format has a plus
(“+”). In comparison with the other formats, the
DVD+R/RW format was last to be introduced. The
rewritable DVD+RW variant was introduced in late 2001, before
its write-once variant was even conceived.
The
write-once DVD+R variant was later announced by Philips at the
2002 Consumer Electronics Show for introduction in
mid-2002. DVD+R/RW competes directly with the DVD-R/RW
format. Interestingly, DVD+R and DVD+RW formats are not
endorsed by the DVD Forum, nevertheless, the following
manufacturers have committed to this format: Sony (who also
supports the DVD-R/RW format), Yamaha, Thomson, Ricoh,
Mitsubishi Chemical, Hewlett-Packard, Dell, and
Microsoft. Together, they call themselves the DVD+RW
Alliance. Microsoft joined the DVD+RW Alliance late,
in May 2003.
So what does the DVD+R/RW format have going
for it? Well, technically the DVD+R variant allows
editing to be performed until the disc is finalized. And
finalizing a DVD+R disc takes about one minute, versus more for a DVD-R disc. Philips claims that
DVD+R/RW is backwards compatible with most existing
DVD-Video players and computer DVD-ROM drives.
Realistically, expect about
85% backwards compatibility for DVD+R and about
65% backwards compatibility for DVD+RW.
 DVD+R holds 4.7 GB for a
single-sided disc, or 9.4 GB for a double-sided disc.
Video can be recorded in High Quality (HQ) or standard play
(SP) recording mode for up to 500 lines of resolution, or in
Long Play (LP) or extended play (EP) recording mode for up to
250 lines of resolution. The DVD+R/RW formats use
“lossless linking” to maximize recording time. This
works by minimizing the large blank spots caused by multiple
recording sessions. Like DVD-R, DVD+R uses a red laser
to permanently transform a dye-recording layer on the DVD+R
disc for write-once recording. DVD+R has an expected
lifespan of about 30-100 years.
 DVD+RW uses phase-change
technology for multiple re-rewrites, up to 1,000 cycles.
It boasts a defect management feature and short formatting
time. DVD+R/RW writes data from the inside edge
spiraling out the outer edge, just like a DVD-Video
disc. The format supports recording in both constant
angular velocity (CAV) (constant rotation speed) and constant
linear velocity (CLV) (constant linear track speed, with disc
rotation faster when the track being written to/read from is
closer to the inner hub) modes. You should always use
the CLV mode, since CAV recordings cannot be read by DVD-Video
players and computer DVD-ROM drives.
The current crop of DVD+R/RW recorders
available today includes Philips, Yamaha, and Sony. DVD+R/RW drives are
available for personal computers, and you can use it to burn
your DVD+R or DVD+RW disc when you’re done with your
non-linear editing and DVD authoring.
Philips
DVDR 985 DVD+R/RW recorder
DVD-RAM Format
 The third recordable DVD format
is DVD-RAM. It was invented
by Matsushita, the parent company of Panasonic and Technics,
and was introduced in summer of 1998. The DVD-RAM format
is supported by the DVD Forum. A DVD-RAM disc looks like
any other DVD, and the name DVD-RAM incorporates the letters
“DVD”. But make no mistake, DVD-RAM is in many ways not
a real DVD. As the second part of its name clearly
states, it is like random access memory (RAM). The
easiest way to explain the DVD-RAM format is to think of it as
a removable hard disk. DVD-RAM uses phase change dual
and magneto-optic technologies for up to 100,000 recording
cycles.
A single-sided 12-cm (4.75-inch) DVD-RAM disc
holds 4.7 GB, so a double-sided
12-cm DVD-RAM disc holds 9.4
GB. DVD-RAM discs also comes in a compact size of 8-cm
(3-inch). This smaller version is used in DVD-RAM
camcorders from Hitachi and Panasonic. A double sided
8-cm DVD-RAM disc has a capacity of 2.8 GB, enough
for 60 minutes of high resolution video. The early
version of the DVD-RAM format required a disc cartridge (or
caddy), while later models may or may not use the cartridge
design. The current design allows the disc to be removed
from the cartridge housing. DVD-RAM is expected to have
a lifespan of about 30 years.
DVD-RAM’s principal advantages are its
removable hard disk characteristic and robustness, making it
ideal for computer data storage. Data storage is random
and non-linear, meaning data can be stored in non-contiguous
blocks, much like a computer hard disk. In a video
editing application, as you perform cut and insert video
editing functions with a DVD-RAM recorder, the video streams
can be dynamically linked in the new order that they’re
edited, without having to re-record video streams on the disc
in physical sequential order. This is the random access
feature of DVD-RAM. Additionally, DVD-RAM incorporates a
defect management feature to ensure that the video stream is
recorded in a non-defective area of the disc, so content loss
is minimized.
Inherent in its design, a DVD-RAM disc is
incompatible with virtually all DVD players and computer
DVD-ROM drives. Only DVD-Video players made by Panasonic
since 2001 are playback-compatible with DVD-RAM discs.
Such players are designated by Panasonic as “DVD-RAM
compatible”. The backwards incompatibility issue puts
the DVD-RAM format at a huge disadvantage when it comes to
sharing home videos and other recordings with family and
friends.
Few other consumer electronics
manufacturers have embraced the DVD-RAM format. DVD-RAM drives are also
available for personal computers. For computer data
storage applications, DVD-RAM is a highly attractive format
for the reasons we previously discussed.
Panasonic
DMR-E50 DVD-RAM and DVD-R recorder Standalone DVD
recorder or a computer with recordable DVD drive
Since you can record DVDs using either a
standalone DVD recorder or a computer with a recordable DVD
drive, which is the better choice? The answer depends on
what you want to do.
-
 transfer, copy,
distribute/share, and archive home video collection on
recordable DVD media
-
time shift TV programs to view at a more
convenient time, using recordable DVD media
If this is all you want to do then a
standalone DVD recorder is the better choice. However,
if you want to:
-
edit home video footage from your camcorder
and author a professional-looking DVD, complete with
chapters/scene selections
-
archive video footage downloaded from the
web and play them back on your DVD-Video players and
computer DVD-ROM drives
Then you will need a personal computer with a
DVD recordable drive and a video editing and DVD authoring
software package. Standalone DVD recorders
are not up for these last two tasks. They are, however,
more adept at replacing the VCR in the role of time shifting
TV programs.
Nowadays, some DVD recorders are offering
multi-format record compatibility. For example, the
Panasonic DMR-E50 recorder offers rewritable DVD-RAM and write-once DVD-R
recording. The Sony RDR-GX7 recorder can record
to DVD-R/RW and DVD+RW. Now, that some DVD recorders
offer multiple format compatibility , it is better to choose
from these multi-format machines.
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