Chapter 1

210 Everything You Ever Wanted to Know About DVD
(4.5 gigabytes) from a computer will not fit on a 4.7-GB disc (4.7 billion
bytes), since the file contains 4.8 billion bytes.
To make things worse, data transfer rates when measured in bits per
second are almost always multiples of 1000, but when measured in bytes
per second are sometimes multiples of 1024. For example, a 1x DVD drive
transfers data at 11.08 million bits per second (Mbps), which is 1.385 million
bytes per second, but only 1.321 megabytes per second. The 150 KB/s
1x data rate commonly listed for CD-ROM drives is “true” kilobytes per second,
since the data rate is actually 153.6 thousand bytes per second. This
book uses kbps for thousands of bits/sec and Mbps for millions of bits/sec
(note the small “k” and big “M”).
In December 1998, the IEC produced new prefixes for binary multiples:
kibibytes (KiB), mebibytes (MiB), gibibytes (GiB), tebibytes (TiB), and so on.
These prefixes may never catch on, or they may cause even more confusion,
but they are a valiant effort to solve the problem. The big strike against
them is that they sound rather silly.
Acknowledgments
This book and the online FAQ has been written and is maintained by Jim
Taylor. The following people contributed to early versions of the DVD FAQ.
Their contributions are deeply appreciated. Information has also been taken
from material distributed at the April 1996 DVD Forum, May 1997
DVD-R/DVD-RAM Conference, and October 1998 DVD Forum Conference.
Robert Lundemo Aas
Adam Barratt
David Boulet
Espen Braathen
Wayne Bundrick
Irek Defee
Roger Dressler
Chad Fogg
Dwayne Fujima
Robert “Obi” George
Henrik “Leopold” Herranen
Kilroy Hughes
Mark Johnson
Ralph LaBarge