On Ubuntu, I use avconv on the command line:
avconv -i input.m4a output.wav
You can also use FFmpeg with the same syntax, simply replacing avconv
with ffmpeg
.
This can do every M4A in a directory, combined with a for loop:
Linux:
for f in *.m4a; do avconv -i "$f" "$"; done
Windows (directly in the command prompt):
FOR %G IN (*.m4a) DO avconv -i "%G" "%~nG.wav"
Windows (in a batch file):
FOR %%G IN (*.m4a) DO avconv -i "%%G" "%%~nG.wav"
If you want a GUI, you may consider WinFF, which is a GUI for FFmpeg.