DivX
DivX is a container format developed by DivXNetworks for compressed video streams, based on MPEG-4. The patented video compression works very efficiently and reduces video files to about one tenth of the uncompressed file format. DivX uses only compressed video files; audio must be compressed using audio compression, such as MP3.
Since DivX can be transmitted at transfer rates of about 600 kbit/s, it is also suitable for playing video from the Internet.
DivX is based on optimization of human psychovisual perception. As with MP3 audio compression, DivX incorporates certain algorithms into video compression that allow for increased data reduction. These include, for example, the Rate Distortion algorithm or Peak Signal to Noise Rejection( PSNR). The improvement in compression is also due to an internal architectural change inthe decoder, which processes multiple blocks of data simultaneously.
DivX files must always be played with the version they were compressed with, as newer DivX versions are not compatible with older versions.