MPEG-4 Structured Audio (MP4 Structured Audio)

SAOL, SASBF, SASL, Audio BIFS, and more

Machine Listening Group
MIT Media Laboratory

Welcome! This page is the jumping-off point for visitors who want to read about, learn about, use, or build tools based on the MPEG-4 Structured Audio standard. MPEG-4 Structured Audio is the collective name for a set of tools which allow powerful and flexible description of sound in a variety of ways. Tools based on the MPEG-4 standard will be the future platform for computer music, audio for gaming, streaming Internet radio, and other multimedia applications. MPEG-4 Structured Audio and AudioBIFS are free standards created through the open standardization process and released into the public domain. They are completely free for anyone to us. This site is the best place to learn about these new developments in computer sound processing.

Latest news
10 May 2000: Added hypermail archives of the saol-dev and saol-users mailing lists.
23 Aug 1999: The SA Links Page is now available.
23 Aug 1999: John Lazzaro of the University of California has written a new implemention of the SA tools, called sfront , and an online book to help you learn SAOL. Click here to check them out.
29 Apr 1999: The Final Draft of the software and standard are now available!
Click here to download the standard as a PDF file (703 KB).
Click here to download the reference software and release notes.

26 Oct 1998: A new press release announces the harmonization of DLS, SoundFonts, and MPEG-4 SASBF.

28 Sept 1998: The ASI AudioBIFS software is now available (6 KB)

23 Aug 1998: A SAOL profiling tool written by Giorgio Zoia is available for download. (188 KB)

16 May 1998: The Final Committee Draft is now available!
Click here to download (244 KB zipped Word 97 file).
Click here to view it on the WWW (662 KB).
Click here to download as Word 6.0 (206 KB Word 6 file).
Click here to download as a PDF file (775 KB). Thanks to Joe Geigel at Kodek for providing the PDF version.

The main MPEG Audio home page is here.

The rest of the MPEG-4 FCD (5 parts, totaling about 2500 pages) is available here .

Guide to the Site


Read about Structured Audio history and concepts.

Press Release

Resources for following up the 1998 press releases.


Read about the Structured Audio tools we've developed.

Technical Overview

How does Structured Audio work? Why does it work so well?

Musician resources

The 'saolc' implementation; example instruments; documentation.

Developer resources

Source code, draft standard, pointers to other developers.

Other links

Links inside and outside the Media Lab related to Structured Audio.

Who we are

About the Machine Listening Group and our MPEG participation.

These pages are still under development, so not everything is done yet. If you find a broken link, please let me know.

Quick index

| Alpha tools | BIFS page | Draft standard | Example instruments | Linux tools | Mailing lists | Machine Listening Group | Media Laboratory | MPEG-4 Tools | NetSound | SAOL FAQ | SAOL page | saolc implementation | SGI tools | Source code | Sun tools | Windows tools |

Comments or Questions: email to

Keywords: MPEG-4, MP4, SAOL, Structured Audio