1. What is divx?

2. what is MPEG-4?

1. What is DivX Technology?

----DivX is a digital video compression format based on the MPEG-4 technology. DivX files can be downloaded over high-speed lines in a relatively short time without sacrificing the quality of the digital video.

DivX is a codec (short for compression/decompression) - a piece of software that compresses video from virtually any source down to a size that is transportable over the Internet without reducing the original video's visual quality.

With DivX? video technology, you can compress a DVD to a fraction of its original size. DivX video compression is so efficient you can fit the entire contents of a DVD on a regular data CD with virtually no loss in quality. Now you can take any digital video content, from home movies to your personal DVD collection¹ and save it on CDs to share with friends or store it on your computer's hard drive without spending huge amounts on extra storage.

Traditionally, video on the Internet was grainy, low resolution and postage stamp-sized. Today all that is changing. Since the introduction of DivX? video technology five years ago, video content providers finally have a real solution to deliver their creations to the world without sacrificing visual quality or shelling out major cash for extra bandwidth. Millions of people worldwide are already using their standard high speed connections to download feature-length movies from the Internet in less than the time it takes to watch them.

Not only has DivX? video technology enabled the fast and secure delivery of high-quality, highly compressed digital video, it also frees digital video content from the confines of the computer monitor by allowing viewers to easily transfer it to a certified device and enjoy it right on the living room TV. With the full range of DivX? Certified devices flooding the market this year, you can now easily take that DivX movie created on your computer, pop it into your DivX Certified DVD player and enjoy it on your big screen TV. The DivX codec even lets you make movies specifically for your favorite device, be it Portable (your personal video player for when you travel), High Definition (your fancy new HDTV), Handheld (your video-capable PDA, like Compaq's PocketPC) or Home Theater (your DivX Certified DVD player).

1.1 Who's using DivX??

DivX? is doing for video what MP3 did for music, and we don't call it the world's most popular video compression technology for nothing. DivX software has been downloaded over 200 million times to create or watch high-quality DivX movies. To get in on the action, just download the DivX codec and open any standard media player. The free DivX Player is included with the codec bundle, if you prefer to watch your videos on a player optimized for all versions of DivX content.

2. What is MPEG-4

MPEG-4 is an ISO/IEC standard developed by MPEG (Moving Picture Experts Group), the committee that also developed the Emmy Award winning standards known as MPEG-1 and MPEG-2. These standards made interactive video on CD-ROM, DVD and Digital Television possible. MPEG-4 is the result of another international effort involving hundreds of researchers and engineers from all over the world. MPEG-4, with formal as its ISO/IEC designation 'ISO/IEC 14496', was finalized in October 1998 and became an International Standard in the first months of 1999. The fully backward compatible extensions under the title of MPEG-4 Version 2 were frozen at the end of 1999, to acquire the formal International Standard Status early in 2000. Several extensions were added since and work on some specific work-items work is still in progress. 
MPEG-4 builds on the proven success of three fields: 

• Digital television;
• Interactive graphics applications (synthetic content);
• Interactive multimedia (World Wide Web, distribution of and access to content) 

MPEG-4 provides the standardized technological elements enabling the integration of the production, distribution and content access paradigms of the three fields.

More information about MPEG-4 can be found at MPEG home page (case sensitive): http://mpeg.telecomitalialab.com This web page contains links to a wealth of information about MPEG, including much about MPEG-4, many publicly available documents, several lists of frequently Asked Questions and links to other MPEG-4 web pages. 

The standard can be bought from ISO, send mail to sales@iso.ch. Notably, the complete software for MPEG-4 version 1 can be bought on a CD ROM, for 56 Swiss Francs. It can also be downloaded for free from ISO website: www.iso.ch/ittf - look under publicly available standards and then for ?4496-5? This software is free of copyright restrictions when used for implementing MPEG-4 compliant technology. (This does not mean that the software is free of patents).