audiofilemerge.sh

for mfile in $ifiles
do
    outfile=${mfile%.*}
    ext=${mfile##*.}

    if [ $ext != 'mp3' ]
    then
        _ffmpegcmd1="ffmpeg -nostats -loglevel panic -y -i $mfile -codec:a libmp3lame -qscale:a 3 "$outfile".mp3"
        $_ffmpegcmd1
    fi
    afile="$afile""$outfile"".mp3""$seperator"
done

ffmpeg -nostats -loglevel panic -y -i concat:$afile -acodec copy $ofile"_m.mp3"
ffmpeg -nostats -loglevel panic -y -i $ofile"_m.mp3" -vn -ar 44100 -ac 2 -ab 128k -f mp3 $ofile