DivX
File:DivX logo color.png | |
| Developer(s) | DivX, Inc. |
|---|---|
| Stable release | 6.1
/ December 13, 2005 |
| Operating system | Cross-platform |
| Type | Media player / Codec / Media format |
| Website | www.divx.com |
- 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.), regarded for its ability to compress lengthy video segments into small sizes while maintaining relatively high visual quality. DivX uses lossy MPEG-4 Part 2 compression, where quality is balanced against file size for utility. It is one of several codecs commonly associated with ripping, where audio and video multimedia are transferred to a hard disk and transcoded. As a result, DivX has been a center of controversy because of its use in the replication and distribution of copyrighted DVDs.
Many newer "DivX Certified" DVD players are able to play DivX encoded movies, however, "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 DivX included only a codec, and were named "DivX ;-)", where the winking emoticon was a tongue-in-cheek reference to the failed DIVX system.
History
DivX ;-) 3.11 Alpha and earlier versions generally refer to a hacked version of the Microsoft MPEG-4 Version 2 video codec, extracted around 1998 by French hacker Jerome Rota (also known as Gej). The Microsoft codec, which originally required that the compressed output be put in an ASF file, was altered to allow other containers such as AVI. From 1998 through 2002, independent enthusiasts within the DVD-ripping community created software tools which dramatically enhanced the quality of video files that the DivX ;-) 3.11 Alpha codec could 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.
In early 2000, Rota created a company (originally called DivXNetworks, Inc., renamed to DivX, Inc. in 2005) to improve DivX and steward its development. The company released a clean room version of the codec as DivX 4.0 in July 2001. It is worth noting, however, that DivX 4.0 did not come from scratch. It was actually the result of the work many open-source developers put into it back when it was known as the "OpenDivx" project. However when the page was pulled and the source was closed to become the commercial DivX 4.0, many of the unpaid and unacknowledged developers saved the last CVS snapshot of the OpenDivx code and from there worked to create XviD, rivaling DivXNetworks' commercial efforts. Regardless, DivX, Inc. has been granted patents on parts of the DivX codec, which is fully MPEG-4-Advanced Simple Profile compliant. The next major version, DivX 5.0, was released in March 2002.
The latest generation, DivX 6, was released on 15 June 2005 and expands the scope of DivX beyond "just a codec" to include a full media container format. DivX 6 introduces a new file format called "DivX Media Format" (with a .divx extension) that includes support for the following DVD-like features:
- Interactive video menus
- Multiple subtitles
- Multiple audio tracks
- Chapter points
- Other metadata
- Multiple format
While in previous generations, video encoded with DivX was analogous to video formats such as MPEG-2, in its 6.0 generation, the new DivX Media Format is analogous to media container formats such as Apple's QuickTime. Much in the way that media formats such as DVD specify MPEG-2 video as a part of their specification, the DivX Media Format specifies MPEG-4-compatible video as a part of its specification. However, despite the use of the ".divx" extension, this format is simply an AVI file renamed. The methods of including multiple audio and even subtitle tracks involve storing the data in RIFF headers and other such AVI hacks that have been around for quite a while, such that even VirtualDubMod supports them. Of course, the traditional method of creating standard AVI files is still supported.
Current situation
The current version of DivX (version 6.1) is available from DivX.com for Windows 2000/XP. The latest version of DivX for Mac OS X is version 6.0.0, released December 8th, 2005. A DivX decoder and player is available for free at the DivX website. DivX offers enhancements over the basic DivX player to paying customers.
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 source code of which is maintained by an independent group.
The 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
External links
- DivX.com The official DivX website
- AfterDawn is a good source of tutorials, guides created by experts
- Doom9 is a good source of tutorials, guides created by experts
- Free-Codecs.com A resource site providing codec news, divx-related tools and forum.
- DivX Digest
- DivX Movies
- The XviD Codec XviD, an MPEG-4 codec based on the OpenDivX project
- Vidomi can make/encode and also play/decode DivX & XviD MPEG-4 videos