Understanding MP3

Syntax, Semantics, Mathematics, and Algorithms
by Martin Ruckert

This web site provides supplemental information for the book Understanding MP3. It was previously available from Vieweg Verlag (ISBN 3-528-05905-2) but went out of print; it is now available again in a second edition (containing all known bug fixes) from Amazon

MPEG audio coding became popular under the name MP3. It is now the most important means of delivering high quality audio over the internet and will play the lead role in digital movie sound as well as in digital audio broadcast. The technology is complex and comprises a vast range of topics, from psychoacustics to digital signal processing, and from mathematics to sofware engineering.

The book explains the ideas, the concepts, and the implementation of MP3. Reading it requires no special prerequisites, but still, the book is detailed enough to include a fully executable highly efficient MP3 decoding engine. The book strives to explain the transformation of a bitstream into music in a way that is not only understandable but even enjoyable.

The information provided below is subject to change as the book develops to reach its final stage. Please direct any comments or suggestions for improvements or corrections of errors to the author.

Sample Pages

Software Download

The latest version of source code under LGPL and of binaries can be found on the download page.

Preliminary Table of Content

	Preface
	Table of Contents
1	Introduction
2	Digital Filters and Subband Synthesis
3	Standard Synthesis Subband Filter
4	Subbands, the Key to Audio Compression
5	How To Use `mp32pcm`
6	How `mp32pcm` Works
7	Unpacking the Frame
8	Reading the Bit Stream
9	Improving the Bit Packing: Layer II
10	The Mathematics of Analyzing Components
11	Some new Ideas: Layer III
12	Huffman Coding
13	Advanced Bit Packing: Layer III
14	Low Sample Frequencies
	Appendix
A	Tables and Special Code
B	Theory and Practice of CRC's
C	Equalization
D	Testing Compliance
	List of Figures, Tables, and Equations
	References
	Index
	Crossreference of Identifiers
	Crossreference of Code

Errata

Known errors in the book can be found on the errata page.

Links

LAME (open source mp3 encoder)

mp3-tech (technical information)

m3w (a mp3 streamer for the WWW)

Maintained by Martin Ruckert

Address	Prof. Dr. Martin Ruckert Munich University of Applied Sciences FB07 Mathematik and Computer Science Postfach 20 01 13 80323 München
Email	ruckert@cs.hm.edu