The full form of DVX is Divx Video

DivX is a brand of video codec products developed by DivX, LLC. There are three DivX codecs: the original MPEG-4 Part 2 DivX codec, the H.264/MPEG-4 AVC DivX Plus HD codec and the High Efficiency Video Coding DivX HEVC Ultra HD codec. The most recent version of the codec itself is version 6.9.2, which is several years old. New version numbers on the packages now reflect updates to the media player, converter, etc.

The “DivX” brand is distinct from “DIVX”, which is an obsolete video rental system developed by Circuit City Stores that used custom DVD-like discs and players. The winking emoticon in the early “DivX 😉” codec name was a tongue-in-cheek reference to the DIVX system. Although not created by them, the DivX company adopted the name of the popular DivX 😉 codec. The company dropped the smiley and released DivX 4.0, which was actually the first DivX version, trademarking the word, DivX