don't know, if i'm missing something (manpage at least reports no changes) or not...
i always used to encode mp3 -> mp4 using a command like:
mpg123 -r 44100 -s --wav - xxx.mp3 | neroAacEnc -br 65535 -ignorelength -if - -of xxx.mp4
but starting with 14.0 '--wav' isn't working anymore, it gives me an error like:
[audio.c:630] error: failed to open audio device
[mpg123.c:542] error: failed to reset audio device: Illegal seek