Learn about the Audio Video Interleave (AVI) format, its key features and characteristics, pros and cons, and comparison with MP4. Discover when to choose AVI over MP4. What is AVI Format? AVI, which stands for Audio Video Interleave, is a video file format developed by Microsoft in 1992. It was designed to store both video and audio data within a single file, ensuring synchronized playback of audio and video. AVI files use the Resource Interchange File Format (RIFF), a general container format for multimedia data.