DivX

This article is about the video codec DivX. For the pay-per-view DVD system, see DIVX.

DivX® [daɪvˈeks] is a video codec created by DivX, Inc. (formerly DivXNetworks, Inc.), known for its ability to compress lengthy video segments into small sizes and has been the center of controversy because of its use in the replication and distribution of copyrighted DVDs. Many newer DVD players are able to play DivX movies.

DivX is not to be confused with DIVX, an unrelated attempt at a new DVD rental system employed by the US retailer Circuit City. Early versions of the DivX codec were named "DivX ;-)", where the winking emoticon was a tongue-in-cheek reference to the failed DIVX system.

A typical feature-length movie on DVD is around 7 gigabytes in size; with DivX this can be compressed to around 700 megabytes which fits on a CD-ROM with minimal loss in quality. Various programs are available which can produce a DivX file from a normal video DVD (this process is known as "ripping"). The resulting file can then be stored on hard disk, burned on optical media, or be shared on peer-to-peer networks.

DivX ;-) 3.11 Alpha and earlier versions generally refer to a hacked version of the Microsoft MPEG-4 Version 2 video codec, extracted around 1999 by French hacker Jerome Rota (also known as Gej). The Microsoft codec, originally created for the compression of *.asf files, was altered to allow compression to *.avi files. From 1998 through 2002, independent enthusiasts within the DVD-ripping community created software tools that dramatically enhanced the quality of video files that the DivX ;-) 3.11 Alpha codec can produce. One notable tool is Nandub, a modification of the open-source VirtualDub, which features two-pass encoding (termed "Smart Bitrate Control" or SBC) as well as access to internal codec features.

Rota's company DivX, Inc. eventually produced a clean room version of the codec, thus avoiding potential copyright problems with Microsoft. This codec was named DivX 4 (dropping the smiley), and released in July 2001. DivX, Inc. has applied for patents on parts of the latest DivX codec, which is fully MPEG-4-Advanced Simple Profile compliant. DivX 5, the next major version of the technology, was released in March 2002.

Current situation

The current version of the DivX codec (version 5.2.1) is available through their web site for Windows and Macintosh operating systems. It is neither free software nor open source, but an open source version of the codec—called OpenDivX®—was released by DivX in early 2001, and this version served as the basis for the open source XviD codec, the specification of which is maintained by an independent group. The codec's main competitors in the for-license video compression software market are Microsoft's Windows Media Video series, Apple Computer's Quicktime, and the RealNetworks RealVideo series.

See also

• XviD

External links

• DivX.com
• DivX, Inc. (formerly DivXNetworks, Inc.)
• AfterDawn
• Doom9
• DivX Digest
• DivX Movies
• Open Directory Project: DivX