Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
One solution is the VideoLAN project which runs on GNU/Linux/Unix,<br />
BeOS, Mac OS X, and other operating systems. It includes a player with<br />
built-in CSS decryption. Although the code is different from DeCSS, it’s an<br />
unlicensed implementation and is probably illegal in most countries (see<br />
“What is DeCSS?”).<br />
An alternative approach is to decode the video at the server and send it<br />
to individual stations via separate cables (usually RF). The advantage is that<br />
performance is very good, but the disadvantage is that DVD interactivity is<br />
usually limited, and every viewer connected to a single drive/decoder must<br />
watch the same thing at the same time.<br />
Many companies provide support for streaming video (MPEG-1,<br />
MPEG-2, MPEG-4, and so on) over LANs, but only from files or realtime<br />
encoders, not from DVD-Video discs.<br />
The Internet is a different matter. It takes over a week to download the<br />
contents of a single-layer DVD using a 56k modem. It takes about seven<br />
hours on a T1 line. Cable modems theoretically cut the time down to a few<br />
hours, but if other users in the same neighborhood have cable modems,<br />
bandwidth could drop significantly.<br />
Author’s prediction, made in 2001: The average DVD viewing<br />
household won’t have sufficiently fast Internet connections before<br />
2007 at the earliest. Around that time there will be a new highdefinition<br />
version of DVD with double the data rate, which will once<br />
again exceed the capacity of the typical Internet connection.<br />
What Is DeCSS?<br />
DVDs and Computers 133<br />
CSS (Content Scrambling System) is an encryption and authentication<br />
scheme intended to prevent DVD movies from being digitally copied. See<br />
“What are the Copy Protection Issues?” in <strong>Chapter</strong> 1 for details. DeCSS<br />
refers to the general process of defeating CSS, as well as to DeCSS source<br />
code and programs.<br />
Computer software to decrypt CSS was released to the Internet in October<br />
1999 (see Dana Parker’s article at www.emediapro.net/news99/<br />
news111.html), although other “ripping” methods were available before that<br />
(see “DVD Utilities and Region-free Information” in <strong>Chapter</strong> 6). The difference<br />
between circumventing CSS encryption with DeCSS and intercepting<br />
decrypted, decompressed video with a DVD ripper is that DeCSS can be<br />
considered illegal under the DMCA and the WIPO treaties. The DeCSS<br />
information can be used to “guess” at master keys, such that a standard
Change language