Common movie, computer video file format. Audio Video Interleave (AVI) is a special case of Resource Interchange File Format (RIFF). AVI is defined by Microsoft. The .avi file format is the most common format for audio and video data on a computer. Audio content or video content that is compressed with a wide variety of codecs can be stored in an .avi file and played in Windows Media Player, if the appropriate codecs are installed on the computer.