(For example, in terms of marketshare, MP3 and AAC dominate the personal audio market, though many other formats are comparably well suited to fill this role from a purely technical standpoint.) First public release date is first of either specification publishing or source releasing, or in the case of closed-specification, closed-source codecs ...

Advanced Audio Coding (AAC) is an audio coding standard for lossy digital audio compression.Designed to be the successor of the MP3 format, AAC generally achieves higher sound quality than MP3 encoders at the same bit rate.. AAC has been standardized by ISO and IEC as part of the MPEG-2 and MPEG-4 specifications. Part of AAC, HE-AAC ("AAC+"), is part of …