The trick here is that you connect Traktor to a local Icecast2 install, turn on audio broadcast (with no listeners) in Traktor, and then read XML off the Icecast2 install to extract which song is playing from Traktor. Traktor is very smart about the current song as well. It looks at the decks and crossfader to determine the current, live song, and forwards that to Icecast.

We can extract this and use it for our digital display!

The source for this dumb trick follows below…

(Sorry for the bad layout of this code; I have to fix our CSS file after the recent site upgrade)

#!/usr/bin/perl -w
#
#
# Pull the current song from my local icecast server and forward the
# song data to the snarkatron.
#
# Whatever you set the server name to in Traktor, it will be used as
# the ‘dj subtitle’ on the 2nd line of the display.
#
# J. Adams
#
#

use strict;
use LWP;
use XML::Simple;
use HTTP::Request::Common;

my $lastartist = “”;
my $lasttitle = “”;

while (1) {
# fetch icecast stats.
my $browser = LWP::UserAgent->new;

$browser->credentials(
‘localhost:8000′,
‘Icecast2 Server’,
‘admin’ => ‘XXXXXXXXXXX’
);

my $url = “http://XXXXXXXXXX:8000/admin/stats.xml”;

my $response = $browser->get($url);

die “Error: “, $response->header(‘WWW-Authenticate’) ||
‘Error accessing’,
“\n “, $response->status_line, “\n at $url\n Aborting”
unless $response->is_success;

# parse it
my $xs = new XML::Simple;
my $data = $xs->XMLin( $response->content );

# no source, means no connection to icecast!

if (defined($data->{source})) {

if (($lastartist ne $data->{source}->{artist}) &&
($lasttitle ne $data->{source}->{title}) ) {
print “Update…\n”;
print $data->{source}->{server_name} . “\n”;
print $data->{source}->{artist} . “\n”;
print $data->{source}->{title} . “\n”;

# update snarkatron
my $ua = LWP::UserAgent->new;
my $req = (POST ‘http://XXXXXXXXXXXX/addsong.cgi’,
["djname" => $data->{source}->{server_name},
"band" => $data->{source}->{artist},
"sngtitle" => $data->{source}->{title},
"Add" => "Add"
]);

my $postrequest = $ua->request($req);
my $postcontent = $postrequest->content;
}

$lastartist = $data->{source}->{artist};
$lasttitle = $data->{source}->{title};
} else {
print “WARNING: Traktor is not transmitting to Icecast! Enable the Broadcast! (sleeping for retry…)\n”;
}

# increase for production
sleep(5);

}

Here’s my perl code that makes this work, which may be of interested to anyone using java application servers.

# Find all running DRPs and request a thread dump, pulling the
# thread dump out of ATG’s log and making a private copy for ourselves.
#

my $ATGLOGDIR=”/gl/atg/ATG7.1/home/logs”;
my $ATGOUTDIR=”/gl/atg/threaddump_logs”;

open(P,”ps -auxwww –forest|”);

# prep output
my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) =
localtime(time);

my $tm = sprintf(“%d%02d%02d-%02d:%02d:%02d”,$year+1900,$mon,$mday,$hour,$min,$sec);

open (W,”>$ATGOUTDIR/$tm-threaddump.log”) || die “cannot open log output file”;

while(

) {
if (/startDynamo/) {
# we know that next line will be java
$_ =

;

# ps regexp
if (/\w+[ ]+([0-9]+).* .*\/servers\/(.*)\/logs/) {
print W “Java PPID = $1 name = $2\n”;
$SVR{$1}->{pid} = $1;
$SVR{$1}->{name} = $2;

}

}
}

close(P);

foreach $k (sort keys %SVR) {
# before we do this, we need to open the other file
my $CMD=”ls -lat /gl/atg/ATG7.1/home/logs/ | grep ” . $SVR{$k}->{name} . “_threadDump | awk ‘{ print \$NF }’”;
my $LOGFILE=`$CMD`;

open (R,”<$ATGLOGDIR/$LOGFILE");
seek(R,0,2); # seek EOF

system("kill -3 $k");

# wait for buffer to accumulate
sleep 1;

while() {
print W localtime(time) . ” [" . $SVR{$k}->{name} . "]: ” . $_;
}

close(R);
}
close(W);