I wrote this about a year ago while trying to compile FFmpeg for Cygwin/Windows, based on the claims made in the FFmpeg wiki:
The Fraunhofer FDK AAC codec library. This is currently the highest-quality AAC encoder available with ffmpeg. Requires ffmpeg to be configured with --enable-libfdk-aac (and additionally --enable-nonfree if you're also using --enable-gpl).
However, recently attempting to build FFmpeg with the media-autobuild_suite showed the following when presented with the FDK-AAC build option:
Build FDK-AAC library and binary? [AAC-LC/HE/HEv2 codec]
1 = Yes
2 = No
Note: FFmpeg's aac encoder is no longer experimental and considered equal or
better in quality from 96kbps and above. It still doesn't support AAC-HE/HEv2
so if you need that or want better quality at lower bitrates than 96kbps,
use FDK-AAC.
However, this third-party tool is the only reference I can find to the claim that FFmpeg's default AAC encoder is now superior to FDK-AAC, and the relevant FFmpeg wiki page itself remains unchanged. Is this true, and if so, what was the source for this information?