The MP4v2 library provides an API to create and modify mp4 files as defined by ISO-IEC:14496-1:2001 MPEG-4 Systems. This file format is derived from Apple's QuickTime file format that has been used as a multimedia file format in a variety of platforms and applications. It is a very powerful and extensible format that can accommodate practically any type of media.

MP4v2 was originally bundled with mpeg4ip library, but has been moved into its own maintained library due to a combination of the cessation of support of mpeg4ip and the usefulness of this library on its own.