AVI and AAC explained
AVI is a Microsoft container from 1992. It predates modern video compression and lacks features taken for granted today, such as proper support for variable frame rates and modern codec metadata.
AAC is the successor to MP3 and is the default audio codec for MP4 video, Apple Music and YouTube. At the same bitrate it generally sounds noticeably better than MP3.
- Where AVI files come from
- Old camcorders, legacy Windows software and archived downloads.
- Where AAC is used
- Streaming services, video soundtracks and Apple devices.