Guide to Cataloging DVD and Blu-ray Discs Using AACR2r ... - OLAC

Nomenclature (DVD-5, DVD-10, etc.) is based on an approximation of capacity in
gigabytes. The examples used are currently the most common sizes.
Single-sided, single-layered — Also known as DVD-5, it holds 4.7 gigabytes of digital
data. The "5" in "DVD-5" signifies the nearly 5 gigabytes worth of data capacity. It can
store approximately two hours of digital video and audio for DVD-Video, or 74 minutes
of high resolution music for DVD-Audio.
Single-sided, double-layered — The DVD-9 construction holds about 8.5 gigabytes
and does not require manual flipping -- the DVD player automatically switches to the
second layer in a fraction of a second, by re-focusing the laser pickup on the deeper
second layer. This capability allows for uninterrupted playback of long movies up to four
hours. DVD-9 is often used to put a movie and bonus materials on the same DVD-Video
disc.
Double-sided, single-layered — Known as DVD-10, this construction features a
capacity of 9.4 gigabytes of data. DVD-10s are commonly used to put a widescreen
version of the movie on one side, and a full frame version of the same movie on the
other side. Almost all DVD players require you to manually flip the DVD, although there
are a few DVD players that can perform the side flipping automatically.
Double-sided, double-layered — The DVD-18 construction can hold approximately 17
gigabytes, or about 8 hours of video and audio as a DVD-Video. Four hours of
uninterrupted video and audio can be stored on one side. To access the content on the
other side of a DVD-18, you have to manually flip the DVD. Content providers (e.g.,
movie studios) usually choose to go with two DVD-9s rather than a single DVD-18
because DVD-18s cost far more to produce.
Pre-Recorded Application Data Formats
• DVD-ROM — a commercially produced read-only disc containing computer
programs, data or both. Can hold anywhere between 4.7 and 17 gigabytes of
information. For the most part, the DVD-ROM application format can only be
played back by computer DVD drives.
• DVD-V (DVD-Video) — a standard for storing and reproducing audio and video
based on MPEG video, Dolby Digital and MPEG audio, and other proprietary
data formats.
• DVD-A (DVD-Audio) — equivalent to a standard audio CD which uses Pulse
Code Modulation (PCM) for recording sound, except that it holds some seven
times the information of a regular CD.
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