AES31 is a standard developed by the Audio Engineering Society for the interchange of digital audio projects between different systems. The primary purpose of the standard is to allow exchange of audio editing projects between digital audio workstations (DAWs). The standard is divided into three parts, the highlight of which is the project interchange format, which defines a standard for edit decision lists.
Contents
Parts
Timecode
The standard describes a 'time-code character format' (TCF), which is used to express time code information in character notation. It enables a sample-accurate time to be specified within a 24-hour period.
The format is defined as HHiMMiSSiFFissss, which is composed of hours (HH), minutes (MM), seconds (SS), frames (FF) and samples (ssss), separated by indicators (i). The character used for each indicator signifies the frame count/time base, film framing, video field/time code type, and sample rate, respectfully.
Formatting
The project interchange standard uses plain text files with a custom markup language called 'edit decision markup language' (EDML). A file is divided into sections using XML-style tags, each of which can contain different keywords which are surrounded by parenthesis. An example of the language can be seen below: