Audio Video Interleave (also Audio Video Interleaved and known by its initials and filename extension AVI, usually pronounced /ˌeɪ.viːˈaɪ/) is a proprietary multimedia container format and Windows standard introduced by Microsoft in November 1992 as part of its Video for Windows software. AVI files can contain both audio and video data in an uncompressed file container that allows synchronous audio-with-video playback.
Like the DVD video format, AVI files support multiple streaming audio and video, although these features are seldom used. Codecs popularly used for AVI include DivX and Xvid, although many other codecs can also be contained in an AVI file.
Many AVI files use the file format extensions developed by the Matrox OpenDML group in February 1996. These files are supported by Microsoft, and are unofficially called AVI 2.0. In 2010 the US government's National Archives and Records Administration defined AVI as the official wrapper for preserving digital video.