AES31 is a standard developed by the

Audio Engineering Society The Audio Engineering Society (AES) is a professional body for engineers, scientists, other individuals with an interest or involvement in the professional audio industry. The membership largely comprises engineers developing devices or product ...

for the interchange of

digital audio Digital audio is a representation of sound recorded in, or converted into, digital form. In digital audio, the sound wave of the audio signal is typically encoded as numerical samples in a continuous sequence. For example, in CD audio, samp ...

projects between different systems. The primary purpose of the standard is to allow exchange of audio editing projects between

digital audio workstation A digital audio workstation (DAW) is an electronic device or application software used for recording, editing and producing audio files. DAWs come in a wide variety of configurations from a single software program on a laptop, to an integr ...

s (DAWs). The standard is divided into three parts, the most critical of which is the project interchange format, which defines a standard for

edit decision list An edit decision list or EDL is used in the post-production process of film editing and video editing. The list contains an ordered list of reel and timecode data representing where each video clip can be obtained in order to conform the final cu ...

Parts

;Part 1 - Disk format :Ensures the ability to read files across platforms. ;Part 2 - File format :Specifies use of monaural

Broadcast Wave Format Broadcast Wave Format (BWF) is an extension of the popular Microsoft WAV audio format and is the recording format of most file-based non-linear digital recorders used for motion picture, radio and television production. It was first specified b ...

files ;Part 3 - Project interchange :Provides a method of exchanging edit data in a text format. This allows an audio edit in one DAW to be opened in another, with little or no difference in the mix. The standard focuses on simple and accurate parsing, and human readability.

Timecode

The standard describes a ''time-code character format'' (TCF), which is used to express

time code A timecode (alternatively, time code) is a sequence of numeric codes generated at regular intervals by a timing synchronization system. Timecode is used in video production, show control and other applications which require temporal coordinatio ...

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 In signal processing, sampling is the reduction of a continuous-time signal to a discrete-time signal. A common example is the conversion of a sound wave to a sequence of "samples". A sample is a value of the signal at a point in time and/or spa ...

, respectfully.

Formatting

The project interchange standard uses

plain text In computing, plain text is a loose term for data (e.g. file contents) that represent only characters of readable material but not its graphical representation nor other objects (floating-point numbers, images, etc.). It may also include a limit ...

files with a custom

markup language Markup language refers to a text-encoding system consisting of a set of symbols inserted in a text document to control its structure, formatting, or the relationship between its parts. Markup is often used to control the display of the document ...

called ''edit decision markup language'' (EDML). A file is divided into sections using

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. T ...

-style tags, each of which can contain different keywords which are surrounded by

parenthesis A bracket is either of two tall fore- or back-facing punctuation marks commonly used to isolate a segment of text or data from its surroundings. Typically deployed in symmetric pairs, an individual bracket may be identified as a 'left' or 'r ...

. An example of the language can be seen below: (ADL_ID) "" (ADL_UID) e5135ed0-5bc7-4087-8674-5a97cf4534e2 (VER_ADL_VERSION) 01.01.00 (VER_CREATOR) "SADiE" (VER_CRTR) 05.06.02

References

AES31-1-2001 (r2006)
''AES standard for network and file transfer of audio - Audio-file transfer and exchange Part 1: Disk format'' by the Audio Engineering Society. Published 2001, Reaffirmed 2006.
AES31-2-2006
''AES standard on network and file transfer of audio – Audio-file transfer and exchange – File format for transferring digital audio data between systems of different type and manufacture'' by the Audio Engineering Society. Published 2006.
AES31-3-2008
''AES standard for network and file transfer of audio - Audio-file transfer and exchange - Part 3: Simple project interchange'' by the Audio Engineering Society. Published 1999, Reaffirmed 2008. * * * {{cite book , title=Modern Recording Techniques , author1=David Miles Huber , author2=Robert E. Runstein , publisher=CRC Press , year=2012 , page=273 , isbn=9781136117732

External links

Audio Engineering Society
Audio codecs Metadata Audio Engineering Society standards