Hardware Reference
In-Depth Information
If you are unable to read DVD-R DL media with a DVD drive, try using the Layer Jump
Recording (LJR) recording method in your DVD mastering software if your drive and software
support it. LJR alternates between recording layers during the writing process, rather than
filling one layer before writing to the other layer. This permits a disc to support multisession
recording and is intended to make it easier for DVD drives to read dual-layer media.
DVD-R DL media is currently available in 4x speed from a relatively small number of suppliers,
although some rewritable DVD drives support faster write speeds.
DVD-RW
The DVD Forum introduced DVD-RW in November 1999. Created and endorsed originally by
Pioneer, DVD-RW is basically an extension to DVD-R, just as CD-RW is an extension to CD-R.
DVD-RW uses a phase-change technology and is somewhat more compatible with standard DVD
drives than DVD-RAM. Drives based on this technology began shipping in late 1999, but early
models achieved only moderate popularity because Pioneer was the only source for the drives and
because of limitations in their performance.
The most common types of DVD-RW media support 2x speeds, although 4x and 6x media are also
available. Drives supporting 2x/4x and faster media have several advantages over original 1x/2x
DVD-RW drives, including these:
•
Quick formatting
—1x/2x drives require that the entire DVD-RW disc be formatted before the
media can be used, a process that can take about an hour. 2x/4x and faster drives can use DVD-
RW media in a few seconds after insertion, formatting the media in the background as
necessary. This is similar to the way in which DVD+RW drives work.
•
Quick finalizing
—2x/4x DVD-RW drives close media containing small amounts of data (under
1GB) more quickly than 1x/2x drives.
•
Quick grow
—Instead of erasing the media to add files, as with 1x/2x DVD-RW drives, 2x/4x
and faster DVD-RW drives can unfinalize the media and add more files without deleting
existing files.
However, most DVD-RW drives still don't support lossless linking, Mount Rainier, or selective
deletion of files—all of which are major features of DVD+RW.
Note
Plextor's Zero Link technology does support selective file erasure on DVD-RW media.
Essentially, Zero Link provides an equivalent to DVD+RW's lossless link feature, enabling
DVD-Video players that support DVD-RW media to play edited disks.
DVD+RW and DVD+R
DVD+RW, also called DVD Phase Change Rewritable, has been the premier DVD recordable
standard because it is the least expensive, easiest to use, fastest, and most compatible with existing
formats. It was developed and is supported by Philips, Sony, Hewlett-Packard, Mitsubishi Chemical
(MCC/Verbatim), Ricoh, Yamaha, and Thomson, who are all part of an industry standard group
called the DVD+RW Alliance (
www.dvdservices.org
). Microsoft joined the alliance in February
2003. DVD+RW is also supported by major DVD/CD-creation software vendors and many drive
