A powershell script that uses VLC's audio codecs to convert multiple file in different audio formats to .mp3

audio-convert.ps1

function ConvertToMp3([switch] $inputObject, [string] $vlc = 'C:\Program Files\VideoLAN\VLC\vlc.exe') {
	process {
		Write-Host $_
		$codec = 'mp3'
		$newFile = $_.FullName.Replace("'", "\'").Replace($_.Extension, ".$codec")
		&"$vlc" -I dummy "$_" ":sout=#transcode{acodec=$codec,vcodec=dummy}:standard{access=file,mux=raw,dst=`'$newFile`'}" vlc://quit | out-null
		# Uncomment the next line when you're sure everything is working right
		#Remove-Item $_.FullName.Replace('[', '`[').Replace(']', '`]')
  }
}
 
function ConvertAllToMp3([string] $sourcePath) {
	Get-ChildItem "$sourcePath\*" -recurse -include *.wma,*.aac,*.ogg,*.m4a | ConvertToMp3
}