A lossy digital audio compression format, Advanced Audio Coding (AAC) was developed by a consortium of companies including Apple, Dolby, Fraunhofer IIS, Nokia, and Sony. It was designed to replace the older MP3 format as part of the MPEG-2 and MPEG-4 audio standards. AAC provides better sound quality at the same bit rate or comparable audio quality at lower bit rates, making it a more efficient audio format.
Industry Adoption
AAC is widely supported across various platforms and devices. Apple uses it as the default audio format for iTunes and iOS devices. Android smartphones, digital radio broadcasting services like DAB+ and Digital Radio Mondiale, and internet streaming services such as Spotify and YouTube also support AAC.
Variants and Extensions
- HE-AAC: An extension that provides further improvements in audio quality and compression efficiency.
- LC-AAC: The basic profile of AAC (both MPEG-4 and MPEG-2) known as Low Complexity.
File Packaging
AAC encoded audio files are typically packaged in an MP4 container, most commonly using the filename extension .m4a.
