use strict;
use warnings;

sub process_files {
    my $path = shift;
    opendir (DIR, $path) or die "Unable to open $path: $!";
    my @files = map { $path . '/' . $_ } grep { !/^\.{1,2}$/ } readdir (DIR); closedir (DIR);
    for (@files) {
        if (-d $_) {
            push @files, process_files ($_);
        } else {
           system "ffmpeg -i \"".$_."\" -ab 262144 \"".$_."\".mp3";
        }
    }
    return @files;
}

process_files("D:/torrent/Boards Of Canada - The Campfire Headphase");