download_ustream_live.pl

#!/usr/bin/perl
# this script is an implementation of http://textt.net/mapi/20101018201937

use strict;
use warnings;

use LWP::Simple;

my ($ustream_url, $file, $stop) = @ARGV;

my $usage = <<USAGE;
usage: sudo ./ustream_download.pl USTREAM_URL TARGET_DIRECTORY [rtmpdump stop option]
e.g. sudo ./ustream_download.pl http://www.ustream.tv/channel/naf-libe-events 600
USAGE

die $usage unless $ustream_url;
die $usage unless $file;

my ($amf_url, $title) = get_amf_data($ustream_url);

$file .= '/'.($title || 'stream').'_'.time.'.flv';
$stop ||= 600;

my ($video_url, $video_id) = get_video_url($amf_url);

if ($video_url && (`ps ax | grep '$video_url' | grep -v perl | wc -l` + 0) == 0) {
    my $command = 'rtmpdump -q -v -r "'.$video_url.'" -a "ustreamVideo/'.$video_id.'" -f "LNX 10,0,45,2" -y "streams/live" --stop '.$stop.' -o "'.$file.'"';
    print $command."\n";
    system($command);
}
else {
    die "no video url";
}

sub get_video_url {
    my $url = shift;
    my $amf_bin = get($url);

    if ($amf_bin =~ m|(rtmp://[^/]+/ustreamVideo/(\d+))|m) {
        return ($1, $2);
    }

    return;
}

sub get_amf_data {
    my $url = shift;    
    
    my $text = get($url);
    my $channel_id;
    if ($text =~ /Channel\s+ID\:\s+(\d+)/m) {
        $channel_id = $1;
    }
    else {
        return;
    }
    my $title = $channel_id;
    if ($text =~ /property\=\"og\:url\"\s+content\=\"http\:\/\/www.ustream.tv\/channel\/([^\"]+)\"/m) {
        $title = $1;
    }
    
    return (
        'http://cdngw.ustream.tv/Viewer/getStream/1/'.$channel_id.'.amf',
        $title
    );
}