Capture a radio stream into a podcast

I like the radio show "Morning Becomes Eclectic" on KCRW so I came up with a Perl script to capture the internet stream of the show, add tags to it, add bookmarks to it (so I can skip through songs I don't like by double-clicking my iPhone headphones), and making it a podcast so iTunes and my iPod and iPhone can download new "episodes" when they become available.

KCRW is a great radio station so if you do listen to them you should consider a donation.

Here is the Perl script. It requires one argument, the number of minutes you want to record. Change "username" to your user name. It also requires the programs mplayer, ffmpeg, and Apple's ChapterTool (which you can find on the internet or buried inside GarageBand). Start the built-in webserver and then subscribe to the RSS feed that gets created there using iTunes (/Users/username/Sites/ripper.xml).




#!/usr/bin/perl -w

use XML::Writer;
use IO::File;
use File::Copy;
use XML::RSS;


# get date
use POSIX qw(strftime);
$now = strftime "%b_%d_%Y", localtime;

# let's rock'n roll
my $duration = $ARGV[0];
my $tmp = "/tmp/";
#my $datestamp = `date +%s`;
my $fifo = $tmp."fifo_".$now."\.mp3";
print $fifo;
`mkfifo $fifo`;


# run mplayer and ffmpeg in the background
system("ffmpeg -i $fifo -acodec aac -b 1200 /tmp/eclectic_$now.m4a &");
my $pid = fork();
if (not defined $pid) {
warn "resources not avilable.\n";
} elsif ($pid == 0) {
exec("mplayer -quiet -playlist http://media.kcrw.com/live/kcrwlive.pls -ao pcm:file=$fifo -vc dummy -vo null -ac ffmp3");
exit(0);
print "right after exec gets called\n";
}

# wait the specified time and then kill mplayer
sleep($duration * 60);
kill 2, $pid;
waitpid($pid,0);

# get the length of the file
my $length = `mplayer -vo null -ao null -frames 0 -identify /tmp/eclectic_$now.m4a 2>/dev/null | grep -v "=0" | grep "^ID_LENGTH" | uniq | cut -d"=" -f2`;
chomp($length);
$length = $length / 60;
$length = sprintf("%d", $length);

my $output = new IO::File(">/tmp/output.xml");
my $writer = new XML::Writer(OUTPUT => $output, NEWLINES => 1);
$writer->xmlDecl("UTF-8");
$writer->startTag("chapters", "version" => "1");
$i = 0;
while ($i < ($length+1)){
$writer->startTag("chapter", "starttime" => $i.":00");
$writer->startTag("title");
my $chapter = $i+1;
$writer->characters("Chapter ".$chapter);
$writer->endTag("title");
$writer->endTag("chapter");
$i++;
}
$writer->endTag("chapters");
$writer->end();
$output->close();


# add chapters
print "adding chapters...\n";
`ChapterTool -x /tmp/output.xml -a /tmp/eclectic_$now.m4a -o /tmp/eclectic_$now.m4b`;

#rm -rf $FIFO
#rm /tmp/eclectic_$NOW.m4a

## add tags
print "adding tags...\n";
`AtomicParsley /tmp/eclectic_$now.m4b --overWrite --artist "Morning Becomes Eclectic" --title "MBE- $now" --album "Morning Becomes Eclectic" --artwork /Users/username/Sites/nic_harcourt.jpg`;

# move to web site
print "moving to website directory...\n";
move("/tmp/eclectic_$now.m4b","/Users/username/Sites/") or die "ERROR: $!\n";


## keep the file to a max of $ITEMS entries,
# insert an item into an RSS file and removes the oldest ones if
## there are already 5 items or more

my $rss = new XML::RSS;
$rss->parsefile("/Users/username/Sites/ripper.xml");
my $capture = "/Users/username/Sites/eclectic_$now.m4b";
my $popper = pop(@{$rss->{'items'}}) if (@{$rss->{'items'}} == 5);
if($popper){`rm $popper->{'guid'}`;}
my $date = `date "+%a, %d %h %Y %H:%M:%S %Z"`;
if ( -e $capture) { } else {die "$capture can't be found\n"};
$rss->add_item(
title => "Morning Becomes Eclectic - $date",
link => "http://legacy.kcrw.com/pl/NowPlayDayNew.html",
pubDate => $date,
guid => "$capture",
enclosure => { url=>"http://localhost/~username/eclectic_$now.m4b",
length => (stat($capture))[7],
type => 'audio/x-m4b'
},
mode => 'insert'
);
$rss->save("/Users/username/Sites/ripper.xml");

# cleanup after yourself
unlink "/tmp/eclectic_$now.m4a", "$fifo", "/tmp/output.xml" or die "couldn't delete: $!\n";