MPEG-4

AES Publications
All available articles and documents from the Journal of Audio Engineering Society with search tool including a CD about coding artifacts.
http://www.aes.org/publications/

Apple
Overview of their implementation and contribution to the MPEG-4 standard.
http://www.apple.com/quicktime/technologies/mpeg4/

Applications of Digital Signal Processing to Audio and Acoustics
Book by Mark Kahrs and Karlheinz Brandenburg.
http://www.amazon.com/exec/obidos/ASIN/0792381300

Audio Research Labs
ARL is a commercial laboratory involved in subjective quality assessment methods like preparing and analyzing codec comparisons for 3GPP.
http://www.audioresearchlabs.com/

Coding Technologies
Company that invented Spectral Band Replication (SBR) and combined it with MP3 (mp3PRO) and AAC (aacPlus or HE AAC).
http://www.codingtechnologies.com/

Digital Radio Mondiale
DRM is a world-wide initiative to use analog AM radio for digital sound and services implementing aacPlus at very low bitrates, often mixed up with Digital Rights Management for copy protection.
http://www.drm.org/

Doom9
Besides this forum for audio codecs there are others for container formats and video encoding in general with FAQs.
http://forum.doom9.org/forumdisplay.php?forumid=11

EE Times
"Meeting MPEG-4 advanced audio coding requirements", knowledgeable article summarizing the most important properties of AAC for hardware playback.
http://www.eet.com/story/OEG20011218S0048/

Facial Animation
AT&T Labs develops a computer human interface using 2D and 3D talking head-and-shoulder models driven by a Text-To-Speech synthesizer (TTS).
http://www.research.att.com/projects/AnimatedHead/

Fraunhofer IIS
Information about the different parts of MPEG-4 Natural or General Audio (GA) from one of the inventors of these formats, see also their page about MPEG-2 AAC.
http://www.iis.fraunhofer.de/amm/techinf/mpeg4/audio.html

3GPP SA4
This working group of the standardization organization deals with codecs like enhanced aacPlus or AMR-WB+ used in mobile telecommunication.
http://www.3gpp.org/TB/SA/SA4/SA4.htm

Hydrogen Audio
Forum about audio coding in general with two separate boards for AAC.
http://www.hydrogenaudio.org/

IBM Composite Media Group
Overview of their implementation and contribution to the MPEG-4 standard, especially for the Systems part.
http://researchweb.watson.ibm.com/mpeg4/Projects/

Introduction to Digital Audio Coding and Standards
Book by Marina Bosi and Richard E. Goldberg.
http://www.springer.com/east/home?SGWID=5-40109-22-33356358-0

ISO/IEC
Publicly available standards from the International Organization for Standardization including MPEG-4 with 14496-5 containing the Audio, Visual and Systems parts.
http://standards.iso.org/ittf/PubliclyAvailableStandards/

Machine Listening
Reading list for an MIT seminar, most of the mentioned publications are directly available on their web server or linked to Amazon's book section.
http://web.media.mit.edu/~tristan/Classes/MAS.945/technical.html

Mayah
Hard- and software company for professional broadcasting products with AAC/MP4 support.
http://www.mayah.com/

Mobiledia
Reviews, articles and forum discussions about cell phones capable of AAC/MP4/3GP playback (also called "iTunes" format sometimes, use the site search).
http://www.mobiledia.com/

MPEG LA
Patent pool administrator for the MPEG-4 Systems part of the standard including the MP4 file format.
http://www.mpegla.com/m4s/

MPEG-4 Structured Audio
Technical information and developer resources from the Machine Listening Group at the MIT Media Laboratory, the official homepage for this format maintained by Eric Scheirer.
http://sound.media.mit.edu/mpeg4/

MPEG4.net
Resource for news, information and products about MPEG-4, H.264, Windows Media, High-Definition, Streaming Media and related technologies.
http://www.mpeg4.net/

MP4-SA Developer Tools
John Lazarro and John Wawrzynek from the CS Division, UC Berkeley provide tutorials, downloads, manuals and links related to the Structured Audio format.
http://www.cs.berkeley.edu/~lazzaro/sa/

Mp4-tech
The web archive of the public MPEG Industry Forum mailing list with many knowledgeable participants from companies like FhG, Apple and Microsoft.
http://lists.mpegif.org/pipermail/mp4-tech/

Nokia developer forum
Platform to support the implementation of their software SDKs including AAC/MP4.
http://discussion.forum.nokia.com/forum/

Principles of digital audio
Book by Ken C. Pohlmann.
http://www.amazon.com/exec/obidos/ASIN/0071348190

QuickTime development
Apple offers technical FAQs, knowledge base and publicly available documentation files including the MOV file format.
http://developer.apple.com/quicktime/

Roberto's listening tests
Provides public group comparisons of several AAC codecs and other formats at different bitrates.
http://www.rjamorim.com/test/

Speech Synthesis Examples
Many TTS demos in several languages from different systems with links to their homepages.
http://www.ims.uni-stuttgart.de/~moehler/synthspeech/

Structured Audio Open Group
The main goal of the SAOG was to implement Structured Audio (SA) in open source applications offering a portal for their users with forum and downloads of samples and software.
http://lsiwww.epfl.ch/saog/

Telos Systems
Hardware manufacturer of the Zephyr ISDN codecs for radio and television broadcasters providing articles and brochures about different AAC implementations.
http://www.telos-systems.com/techtalk/

Text-To-Speech Synthesis
Bell Labs' / Lucent Technologies multi-lingual TTS demos and introduction to this coding method.
http://www.bell-labs.com/project/tts/

Tuner2
List of internet radio stations using aacPlus for their low bitrate streams, among them SomaFM.com and Boomer Radio.
http://www.tuner2.com/

Via Licensing
Patent pool administrator for AAC with FAQs and overviews of royalty fees for commercial implementations.
http://www.vialicensing.com/

Hydrogen Audio
Active forum topics in AAC - General and AAC - Tech as well as in MPEG4 Discussion. [RSS]
http://www.hydrogenaudio.org/forums/ssi.php?a=out&f=13,14,44&show=20&type=rss

MPEG4.net Events
Upcoming MPEG-4 and Streaming Media related calendar of events. [RSS]
http://www.mpeg4.net/rss/mp4events.xml

MPEG4.net News
The latest headlines about MPEG-4, Windows Media, Streaming Media and related technologies. [RSS]
http://www.mpeg4.net/rss/mp4news.xml

MPEG4.net Press releases
Announcements of new products from companies or events from organizations related to MPEG-4 and other technologies. [RSS]
http://www.mpeg4.net/rss/mp4press.xml

MPEG4.net Resources
New sources of information like web sites, documentation or tests for MPEG-4 and related technologies. [RSS]
http://www.mpeg4.net/rss/mp4resource.xml