Powershell: Convert MP4's to Wav Files

#script requires VLC to be installed
#does not like apostrophes in filename

$outputExtension = ".wav"
$bitrate = 1411
$channels = 2

foreach($inputFile in get-childitem -recurse -Filter *.mp4)
{
 $outputFileName = [System.IO.Path]::GetFileNameWithoutExtension($inputFile.FullName) + $outputExtension;
 $outputFileName = [System.IO.Path]::Combine($inputFile.DirectoryName, $outputFileName);
 $outputFileName = $outputFileName.Replace("'", "`'");

 $programFiles = ${env:ProgramFiles(x86)};
 if($programFiles -eq $null) { $programFiles = $env:ProgramFiles; }

 $processName = $programFiles + "\VideoLAN\VLC\vlc.exe"

 $fn = $($inputFile.FullName).Replace("'", "`'");

 $processArgs = "-I dummy -vvv `"$fn`" --sout=#transcode{acodec=`"mp3`",ab=`"$bitrate`",`"channels=$channels`"}:standard{access=`"file`",mux=`"wav`",dst=`"$outputFileName`"} vlc://quit"

 #echo $processArgs
 start-process $processName $processArgs -wait
}