AAF (Advanced Authoring Format)

A picture editor works in one program and the sound editor in another, usually Pro Tools. What needs to travel is not a finished audio file but the whole timeline: which clips sit where, how long they are, where they fade in and out. Avid's OMF did this first in the early 1990s. AAF came around 2000 from an industry group led by Avid and Microsoft, and is built on Microsoft's Structured Storage, the same container as the old Office files.

In practice AAF is dependable for the basics and temperamental for everything else. Clips and fades make it across; volume automation and plugin settings sometimes do, depending on which two programs are trying to understand each other. That is why stems and a reference mix usually get sent along as a lifeline.