avi The AVI file format is one of the most widely used multimedia containers ever devised. AVI, which stands for audio video interleaved, was first introduced to the public by Microsoft in 1992 as part of their 'video for windows' multimedia framework. Being a container format, an AVI file with the .avi filename extension can exist with both video and audio content synchronized for playback. The format can thus be used by authors to edit and encode audio video sequences or just video sequences. The Digital video AVI format exists in two forms, Type 1 and Type 2.