All available articles and documents from the Journal of Audio Engineering Society with search tool including a CD about coding artifacts.

Book by Mark Kahrs and Karlheinz Brandenburg.

ARL is a commercial laboratory involved in subjective quality assessment methods like preparing and analyzing codec comparisons for 3GPP.

Company that invented Spectral Band Replication (SBR) and combined it with MP3 (mp3PRO) and AAC (aacPlus or HE AAC).

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.

"Meeting MPEG-4 advanced audio coding requirements", knowledgeable article summarizing the most important properties of AAC for hardware playback.

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.

Besides this forum for audio codecs there are others for container formats and video encoding in general with FAQs.

Publicly available standards from the International Organization for Standardization including MPEG-4 with 14496-5 containing the Audio, Visual and Systems parts.

Overview of their implementation and contribution to the MPEG-4 standard.