Ifølge en tråd på itsvar.dk kan det ikke svare sig at konvertere fra mp3 til m4a:
"How best to convert audio files from MP3 to M4A/MP4 format?
Don't do it using MP3s! Transcoding is the process of converting audio files from one format to another. Since many people have their audio files stored as MP3 files, this is a very common question. MP3 is a lossy compression codec (algorithm) that "tosses away" some of the original audio information when a MP3 file is created (encoded). MPEG 4 Audio is a much better encoder than MP3 is (quality-wise and resulting file size-wise). The problem is that going from one lossy audio format to another introduces even more loss in the conversion process (transcoding process). It is the advice of audio experts to never transcode from MP3 to M4A. The loss and distortion is not recommended. Instead, use your .WAV master audio files, re-rip the master audios from your audio CDs or use your audio files that are stored in a lossless audio file format such as FLAC or APE. There are many programs available that can convert from a lossless audio file (or audio CD) to a pristine sounding MPEG 4 Audio file (M4A or MP4). "
Hvis du alligevel vil konverteresådan, vil jeg stærkt anbefale programmet dbpoweramp (
http://www.dbpoweramp.com/dmc.htm ) , som kan konvertere mellem de fleste kendte formater - et super værktøj!
