WAV is a digital audio format that stores waveform data. You can easily reformat a WAV file into an M4A file, which is an audio file created as part of the multimedia MPEG-4 format. Some examples of ...

What you want is BarbaBatch but it's not free. It does handle the format you require. Might be a free trial. Audacity (freeware, google for it) will export to A.law encoded wav. Don't know whether it ...