mAirList uses the BASS Audio Library for all handling of audio files, streams, sound playback and recording.

BASS supports a number of audio formats out of the box, including WAV, MP3 and Ogg Vorbis.

Additional codecs may be provided by your operating system. For example, Windows 7 and above provide an AAC codec for playback of M4A files (e.g. from iTunes).

Note: The codecs provided by Windows will usually only allow playback of the respective file; for metadata import (reading file tags from e.g. M4A files), you must install the appropriate BASS add-on. Also some Windows codecs are known to have issues with some files, so it's a good idea to install the separate add-on and not rely on the Windows codec.

BASS add-ons for various formats can be downloaded free of charge from this page:

http://www.un4seen.com/bass.html#addons

To install an add-on, download and extract the ZIP file, then copy only the single DLL file (e.g. bass_aac.dll for AAC) to the mAirList plugin folder:

C:\Program Files (x86)\mAirList <version>\plugins\bass

After you restart mAirList, the plugin should be listed in the configuration app under Audio Settings → General → Info: