Part 1: What is "DVD" Media, and How Is It Different From CDs?
Answer: DVD, which was originally named for Digital Video Disc, now means Digital Versatile Disc. It is a special recording format for computers, audio, and TV/movies.
Superficially, a DVD disc looks just like a CD. It is 120mm in diameter, and 1.2mm in thickness(comprised of two polycarbonate substrates, 0.6mm each). Unlike CDs, however, DVD discs can be single or double sided. Furthermore, each DVD side may contain a second invisible "layer" to increase the disc's storage capacity.
On just one side, a DVD media disc can hold up to 13 times the information of a standard CD (13 x 700 megabytes).
Common DVD storage capacities are:
4.7GB (single sided/single layer)
9.4GB (double sided/1 layer)
8.5GB (single sided/dual layer)
17.1GB (double sided/dual layer)
Trivia: DVD discs are very data-sturdy, and do not wear out through repeated use. And unlike VHS cassettes and floppy diskettes, DVD discs are unaffected by magnetic fields. A DVD movie you buy, even after 10,000 playings, will have video reproduction identical to the day you bought it.
Part 2: Choosing a DVD Player-Burner For Yourself: DVD "dash" R versus DVD "plus" R
If you simply need a DVD player for your PC or your TV, then the choices are relatively straightforward. Outside of the bells and whistles of "progressive scan", bookmarking, and other enhancements, every DVD player is effectively the same for the basic functions.
If you are shopping for a DVD player-burner (that plays AND records DVDs), then you have two major format choices to evaluate, and they can be confusing:
Burner Choice 1) DVD-R or DVD-RW Format
Burner Choice 2) DVD+R or DVD+RW Format
Overview of DVD Recordable: +R Versus -R
As of June 2006, there is no physical difference between a DVD-R/-RW disc and a DVD+R/+RW disc.
There is, however, a series of technical differences between DVD-R/-RW DVD+R/+RW recorder format. The DVD+R/+RW format offers subtle extra functionality for people who record their own movies and audio.
The Standards Differences
1) The DVD-R (pronounced "DVD dash R") and -RW media formats are officially approved by the standards group DVD Forum. The DVD Forum was founded by Mitsubishi, Sony, Hitachi, and Time Warner, so it has tremendous industry support for its technical standards.
2) DVD+R ("DVD plus” R) and +RW formats are not approved by the DVD Forum standards group, but are instead supported by the DVD+RW Alliance. The DVD+RW Alliance is supported by Sony, Yamaha, Philips, Dell, and JP, so it also has tremendous industry support for its technical standards. Note that Sony supports both organizations.
3) Trivia "DVD Slim" format is not approved by any standards body.
4) Trivia: DVD RAM is a late 1990's format that has lost popularity, and is effectively a non-choice for consumers today, since most movies in 2004 will not play on DVD RAM.
The Functional Differences
The main functional differences between DVD-R and DVD+R are:
1) the DVD recorder's built-in defects management,
2) the way the recorders format and rewrite DVDs,
3) the price.
According to the claims of the DVD Alliance, using a DVD+R/+RW recorder will let you do the following:
1. Instantly eject without having to wait for finalized formatting.
2. Ability to record one DVD disc partially on PC and partially on television.
3. Background formatting: while the disc is being formatted, you can simultaneously record on already-formatted portions of the same disc.
4. Enhanced ability to edit filenames, movie and song titles, and playlists.
5. 100% compatibility with all other DVD players, while still enjoying these extra recording features.
by Paul Gil
No comments:
Post a Comment