Xvid is a free implementation of the MPEG -4 video codec, originally based on the OpenDivX source code. The underlying source of OpenDivX came again from the MPEG-4 reference implementation of the EU project MoMuSys. The Xvid project was started by several volunteer programmers after the source code of OpenDivX was closed. The project name is an anagram of the name DivX. Through the unencrypted source code published by OpenDivX the programmers were given the opportunity to change the codec in the basic characteristics and to optimize. Together with DivX Xvid is the best-known MPEG -4 codec.
Account of patent difficulties no official compiled versions of the source code provided by the Xvid team. A commercial distribution of Xvid is possible as long as you stick to the GPL terms. In some countries such as the USA or Japan in addition fees for the patents listed above apply.
Since version 1.1.3 of 29 June 2007, the MPEG -4 Visual Advanced Simple Profile is supported. That is, Xvid support Advanced Simple Profile features such as b-frames, Quarter Pixel Motion Compensation ( QPel ), Global Motion Compensation (GMC ) and custom quantizer matrices. Since December 2005, the beta code Xvid AVC to be published. The new codec supports the efficient H.264/AVC standard.
In January 2001 DivX Networks OpenDivX founded as part of Project Mayo, which should accommodate open source multimedia projects. OpenDivX was an open-source MPEG -4 video codec, written from scratch; However, the code has been placed under a limited license, and only members of the DivX Advanced Research Centre ( DARC ) had write access to the CVS. In spring 2001, DARC member Sparky wrote an improved version of the encoder core, called encore2, which was then removed from CVS without warning. The Declaration of Sparky was: "We (our supervisor ) decided that we are not yet ready to show it to the public " ( translated).
In July 2001, developers started to complain about a lack of activity in the project since the last code change was already months ago, improvements of program errors were ignored and the promised documentation had not appeared. Shortly thereafter DARC published a beta version of their closed source and commercial DivX MPEG-4 codec, which was based on encore2, with the statement " What the community really wants is a Winamp, not a Linux" ( translated). Some accused DivXNetworks to have OpenDivX only started to collect other people's ideas and they then use in their DivX 4 codec; some were disappointed that the code development had stagnated, but wanted to work on it further, while others were angry about how DivXNetworks handles a so-called open- source project. After a fork of OpenDivX was created that uses the latest version of encore2 that a few people had downloaded itself before it was removed. Since then, the entire OpenDivX code was replaced and Xvid published under the GPL.
Sigma Designs controversy
In July 2002, published a Sigma Designs MPEG -4 video codec, called Real Magic MPEG -4 video codec. After a short time it was discovered that it contained a portion of the Xvid code. Sigma Designs has been notified and confirmed that a programmer Real Magic had built on Xvid - but also assured to replace the GPL code in order to avoid copyright infringement.
As a Sigma Designs released the allegedly rewritten Real Magic codec, Xvid him the developers have decompiled and found that it still contained Xvid code again; only converted, in an attempt to disguise the origin. The Xvid developers decided then to expose their work to Xvid and to go public in order to force Sigma Designs to comply with the provisions of the GPL. After Slashdot and The Inquirer reported on Sigma Designs agreed to open the source code for their Real Magic MPEG -4 video codec.
When installing the Xvid encoder is a package installed, which allows easy to convert files into the MPEG-4 standard.
They support almost all popular formats (except for some proprietary formats), they also offer a vast number of settings.