Youtube downloader

#!/usr/bin/perl
use strict;
use warnings;
use LWP::Simple;
use LWP::UserAgent;

print "starting first page retrievaln";
my $urlin  = shift || "http://youtube.com/watch?v=vCsQLQ00hvs";
my $content = get( $urlin  ) or die "argh : $!n";
print "done first page retrieval : $urlinn";

my $infile     = ($content =~ m{<title>([^<]+)</title>})[0] . '.flv';
my ($video_id) = ($content =~ /watch_fullscreen?(?:.*?)video_id=([^&]+)/);
my ($t_id)     = ($content =~ /watch_fullscreen?(?:.*?)t=([^&]+)/);

my $get_url = "http://www.youtube.com/get_video?video_id=$video_id&t=$t_id";

print "gettin video file : $infilen";

$| = 1;
open(IN,"> $infile") or die "$_n";
my $ua = LWP::UserAgent->new();
my $received_size = 0;
my $url = $get_url;
print "Fetching $urln";
my $request_time = time;
my $last_update = 0;
my $response = $ua->get($url,
                        ':content_cb'     => &callback,
                        ':read_size_hint' => 8192,
                       );
print "n";
close IN;


sub callback {
  my ($data, $response, $protocol) = @_;

  my $total_size = $response->header('Content-Length') || 0;
  $received_size += length $data;
  print IN $data;
  my $time_now = time;
  return unless $time_now > $last_update or $received_size == $total_size;
  $last_update = $time_now;
  print "rReceived $received_size bytes";
  printf " (%i%%)", (100/$total_size)*$received_size if $total_size;
  printf " %6.1f/bps", $received_size/(($time_now-$request_time)||1)
  if $received_size;
}