Batch convert music/video files from one format to another using Perl (Mojo) and vlc. See also https://wiki.videolan.org/VLC_command-line_help

convert.pl

#!/usr/bin/env perl
use Mojo -strict;
use Mojo::File qw(path);
# cd to the directory where your files are
# and run this program
# $0 $format_in $format_out
my ($format_in, $format_out) = @ARGV;
say qq|Converting from "$format_in" to "$format_out"|;
for my $file ( path('./')->list->each ) {

#vlc -I dummy 0.$format_in --sout=#transcode{acodec=$format_out,channels=2,samplerate=44100}:standard{access=file,mux=raw,dst=0.$format_out} vlc://quit
    if ( $file =~ /\.$format_in$/ ) {
        my $out = $file;
        $out =~ s/\.$format_in$/.$format_out/;
        $out =~ s/\s+/_/g; #spaces to _
        $out =~ s/(\D)(\d)\./${1}0${2}./;# trak1 to track01
        say "converting $file to $out";
        system(
            "vlc",
            "-I",
            "dummy",
            $file,
"--sout=#transcode{acodec=$format_out,channels=2,samplerate=44100}:standard{access=file,mux=raw,dst=$out}",
            "vlc://quit"
        );
    }
    #last
}