Hardware Reference
In-Depth Information
meeting these specifications.
You can obtain the MultiRead specification (revision 1.11, October 23, 1997) and MultiRead 2
specification (revision 1.0, December 6, 1999) from the OSTA website.
MultiPlay and MultiAudio
The MultiPlay specification was developed in 2000-2001 by OSTA to ensure that CD-R and CD-
RW discs created on a personal computer could also be played back on consumer CD and DVD
players. Supported content types include Red Book Audio, CD-Text, Slideshow (JPEG photos), and
Video CD. Players that also meet the MultiAudio standard from OSTA can play MP3, WMA, and
other compressed audio formats and read information stored for each track such as track name; year
recorded; names of composer, songwriter, performer and arranger; album name; genre.
DVD
DVD in simplest terms is a high-capacity CD. In fact, every DVD-ROM drive
is
a CD-ROM drive;
that is, it can read CDs as well as DVDs. (Some older standalone DVD players can't read CD-R or
CD-RW discs, however.) DVD uses the same optical technology as CD, with the main difference
being higher density. The DVD standard dramatically increases the storage capacity of, and therefore
the useful applications for, CD-sized discs. A CD can hold a maximum of about 737MB (80-minute
disc) of data, which might sound like a lot but is simply not enough for many applications, especially
where the use of video is concerned. DVDs, on the other hand, can hold up to 4.7GB (single layer) or
8.5GB (dual layer) on a single side of the disc, which is more than 11 1/2 times greater than a CD.
Double-sided DVDs can hold up to twice that amount, although you currently must manually flip the
disc over to read the other side.
Up to two layers of information can be recorded to DVDs, with an initial storage capacity of 4.7GB
of digital information on a single-sided, single-layer disc—a disc that is the same overall diameter
and thickness of a current CD. With Moving Picture Experts Group standard 2 (MPEG-2)
compression, that's enough to contain approximately 133 minutes of video, which is enough for a full-
length, full-screen, full-motion feature film—including three channels of CD-quality audio and four
channels of subtitles. Using both layers, a single-sided disc could easily hold 240 minutes of video or
more. This initial capacity is no coincidence; the creation of DVD was driven by the film industry,
which has long sought a storage medium cheaper and more durable than videotape.
Note
It is important to know the difference between the DVD-Video and DVD-ROM standards.
DVD-Video discs contain only video programs and are intended to be played in a DVD player
connected to a television and possibly an audio system. DVD-ROM is a data-storage medium
intended for use by PCs and other types of computers. The distinction is similar to that between
an audio CD and a CD-ROM. Computers might be capable of playing audio CDs as well as
CD-ROMs, but dedicated audio CD players can't use a CD-ROM's data tracks. Likewise,
computer DVD drives can play DVD-Video discs (with MPEG-2 decoding in either hardware
or software), but DVD-Video players can't access data on a DVD-ROM. This is the reason
you must select the type of DVD you are trying to create when you make a writable or
rewritable DVD.
