AAC support was broken due to ffmpeg deprecating the currently-used libfaac transcoder. Reworked to test for the new one.
Review Request #130142 - Created May 26, 2017 and submitted
Working AAC format detection and transcoding option. I have to admit that most of this work was done by a helpful user on the Ubuntu forums, but I have tested the patch. See https://ubuntuforums.org/showthread.php?t=2348624&page=2&p=13642704#post13642704 for the original discovery of the bug. It is also on the Amarok bug list at https://bugs.kde.org/show_bug.cgi?id=374670#c11
I patched Amarok 2.8.4 and then compiled Amarok. I then tested to see if AAC transcoding worked. The option appeared and it did indeed transcode to AAC format. I also updated the patch to work with the latest version from Git here at KDE (however the patch had been created, it was not in git format).
Hm, what is Amarok 2.8.4? That is not a release version number I am familar with.
Are you the same person who comments on the bug? Did you test this patch, e.g. does Amarok build and does it pass all the unit tests?