Xvid Codec
Xvid codec is an open source video compression/decompression software developed under the Xvid video compression project. Codecs are used to store and use video in digital form. In the old days, this was accomplished by using analog signal on magnetic tape. As digitized media formats like MPEG started to emerge, software that can compress and extract video files were created.

Compressed video files take much less space than their uncompressed counterparts and considerably cuts file transfer time. According to its website, the XviD codec compresses DVD films to CD-sized files without sacrificing image and audio quality.
Xvid itself is not a video format; it is a program for compressing and decompressing movie files into the MPEG-4 ASP format. Xvid encoded files are called “MPEG-4 ASP video” and can be opened using media players that support MPEG-4 ASP formats like VLC, Perian and MPlayer.
The Xvid codec is similar to DivX Pro Codec, a video file compressor software developed by DivX, Inc. But while DivX is proprietary, Xvid is freeware and under the GNU General Public License. Xvid codec was originally developed for Windows and Linux, but due to its open-source nature, Xvid can be used on all operating systems and platforms. Xvid uses many proprietary technologies, however, and use of Xvid may be restricted by local laws.
Xvid encoded files can also be burned or copied to CDs/DVDs and played in compatible DVD and media players. Xvid is capable of encoding files with advanced MPEG-4 features like MPEG quantization and multiple B frames, but these files may not be supported by DivX players.
Using the Xvid Codec
Now that you know what is Xvid codec, let’s talk about how you can start using the Xvid codec. Many sites host videos that can only be played using an Xvid codec. An error message will usually appear if you don’t have the codec, saying “A plug-in is required to play this video. Install plug-in.” Xvid codec download links are available on our website. This site contains the stable and latest version (1.3.2), which fixes bugs from previous releases and includes the Xvidcore library, interface changes, updated IDCT/FDCT implementation and other updates.
Xvid download codec from here and save it to your computer. Install the file by following the on-screen prompts. You don’t need to run the codec manually; once it is installed, your media player will be automatically updated with the Xvid codec. Open your video using Windows Media Player or VLC and watch the video.
Sometimes you would want to convert other video formats (like MPEG-2) to Xvid-supported MPEG-4 ASP files. To do this, you will need to download video conversion programs like the AVS video converter or Xvid Xilisoft Converter. Download the file converter from Xilisoft or AVS website and install it in your computer.
Xvid Codec Xilisoft Converter
Launch Xvid Xilisoft Converter by double clicking the desktop icon. Click “File” at the top of the window, and then go to “Add Folder.” Look for the files you want to convert and double click them to add to the folder. Once you have the files, click “Browse” and select “Destination.” Double-click the folder where you want to save your converted files. Next, go back to the main program window and check the box next to files you want to convert. Click “Target” and select the output format. Xilisoft can convert Xvid encoded files to MPEG, AVI, MOV and MP3. Finally, click “Convert” on the Xilisoft toolbar to start file conversion.
AVS Video Converter
Launch AVS video converter from the “Start” menu. Click “Browse” to look for files you want to convert and double-click them to add to the file conversion list. Next, click the drop down menu next to “Profile” and select “XviD codec.” Finally, click the “Convert Now” button to start the conversion process. AVS can convert XviD files to MPEG, MOV, FLV and WMV.