Ok, this is something that i had in mind since some time ago but i didn't had the time to actually do it. But now i finished it.
The situation is like this, there is a radio show that i love, but the problem is that this radio show starts at 12 AM and finishes at 2 AM, and usually, I'm doing any other thing at that time in the night.
So, i decided to create some simple script to record the audio in one of my servers (by using the Radio station internet broadcast).
For all this to work, you will need the following things:
- PHP 5.1.6 or newer
- MPlayer
- the GPAC utilitles
- the Nero Digital AAC Encoder
The idea for the bash script to record the audio stream is based on a nice tutorial by Phil Salkie, but honestly, i think i improved it a lot, specially because it uses a FIFO as temporary storage, and because it compresses the audio to a more recent audio format like HE-AAC.
Basically, the following bash script will record any audio stream of your choice and will convert it to a HE-AAC file inside an m4a container compatible with any audio player out there AND iTunes / iPod of course 
After the audio file is done, the second script will generate a podcast feed (RSS) compatible with iTunes or any podcast client out there, like for example Juice.
Here is the script to capture the radio show and convert it to a M4A file (AAC Plus inside an MP4 container).
#!/bin/bash
TERM="linux"
# RANDOM GUID GENERATION
SUM=`date`
SUM2=`echo $SUM | md5sum | cut -c 1-8`
# INITIALIZATION VARIABLES
DATE=`date +%F` # Save the date as YYYY-MM-DD
FILE=/home/plusmedia/public_html/media/$DATE---$SUM2.mp4 # WHERE TO SAVE THE STREAM ?
STREAM=mms://200.43.193.143/radio10 # The URL of the stream to save.
FIFO=/tmp/stream.wav # We create a FIFO as intermediate storage for the encoding.
ARTWORK=/home/plusmedia/public_html/lvst.jpg # Path to some artwork file for iTunes, can be JPG or PNG.
DURATION=122m # How many minutes should we record ?
# MP4 TAGS
AUTHOR="Some Author"
ALBUM="Some Radio Show"
TITLE="Some Radio Program - $DATE"
# We use mplayer to capture the stream to a wav file being stored into a FIFO.
mkfifo $FIFO
/usr/bin/mplayer $STREAM -af resample=44100:0:2,volume=0:1,pan=1:0.5:0.5,comp -ao pcm:file="$FIFO" -vo null -vc dummy < /dev/null 2>&1 >/dev/null & pA=$!
# Encoding the fifo to AAC with the Nero Digital Encoder for Linux.
/usr/bin/neroAacEnc -br 24000 -he -if $FIFO -of $FILE & pB=$!
sleep $DURATION # wait for the show to be over
kill $pA # end the mplayer process
sleep 2s # IMPORTANT! wait a while for the Nero encoder to finish and close the opened files.
echo "CREATING M4A AND APPLYING TAGS..."
/usr/bin/MP4Box -add "$FILE#audio" -itags cover="$ARTWORK":artist="$AUTHOR":comment="$DATE":album_artist="$AUTHOR" -lang english -new "${FILE%.*}.m4a"
sleep 1s
echo "Generating Podcast Item..."
# We have a new episode recorded, so it is time to call the podcast generation script to update the RSS feed.
/home/plusmedia/podcast
echo "Deleting FIFO and temporary files..."
rm $FIFO -f
rm $FILE -f
echo "done!"
And this is the PHP script to generate the "iTunes Compliant" podcast feed:
#!/usr/bin/php
setIndent = true;
$xmlObject->openMemory();
$xmlObject->startDocument('1.0','UTF-8');
$xmlObject->startElement ('rss'); //
$xmlObject->writeAttribute( 'xmlns:itunes', 'http://www.itunes.com/dtds/podcast-1.0.dtd');
$xmlObject->writeAttribute( 'version', '2.0');
$xmlObject->startElement ('channel');
$xmlObject->writeElement ('title', $title);
$xmlObject->writeElement ('link', $link);
$xmlObject->writeElement ('language', $language);
$xmlObject->writeElement ('copyright', $copyright);
$xmlObject->writeElement ('itunes:subtitle', $itunesSubtitle);
$xmlObject->writeElement ('itunes:author', $itunesAuthor);
$xmlObject->writeElement ('itunes:summary', $itunesSummary);
$xmlObject->writeElement ('itunes:explicit', $itunesExplicit);
$xmlObject->writeElement ('description', $description);
$xmlObject->startElement ('itunes:owner');
$xmlObject->writeElement ('itunes:name', $ownerName);
$xmlObject->writeElement ('itunes:email', $ownerEmail);
$xmlObject->endElement();
$xmlObject->startElement ('itunes:image');
$xmlObject->writeAttribute ('href', $baseURL.$image);
$xmlObject->endElement();
$xmlObject->startElement ('itunes:category');
$xmlObject->writeAttribute ('text', $mainCategory);
$xmlObject->startElement ('itunes:category');
$xmlObject->writeAttribute ('text', $childCategory);
$xmlObject->endElement();
$xmlObject->endElement();
// ITEMS
$files = scandir($mediaDIR);
$sortedFiles = array();
foreach ($files as $filePath) {
$fileItem = array( 'modified' => filemtime($mediaDIR.$filePath),
'path' => $filePath
);
array_push ($sortedFiles, $fileItem);
}
usort($sortedFiles, "cmp");
foreach ($sortedFiles as $value) {
$extension = substr($value['path'], strrpos($value['path'], "."));
if ($extension == $fileExtension) {
$nameParts = explode("---", parseFileName($value['path']));
$xmlObject->startElement ('item');
$dateComponent = strtotime($nameParts[0]);
$xmlObject->writeElement ('title', $itemTitle.strftime('%A, %B %d, %Y', $dateComponent));
$xmlObject->writeElement ('itunes:author', $itunesAuthor);
$xmlObject->writeElement ('itunes:subtitle', $itunesSubtitle);
$xmlObject->writeElement ('itunes:image', $baseURL.$image);
$xmlObject->writeElement ('pubDate', date('r', $dateComponent));
$xmlObject->startElement ('enclosure');
$xmlObject->writeAttribute( 'url', $baseURL.$mediaURL.$value['path']);
$xmlObject->writeAttribute( 'length', filesize($mediaDIR.$value['path']));
$xmlObject->writeAttribute( 'type', 'audio/x-m4a');
$xmlObject->endElement(); //
$xmlObject->writeElement ('guid', $baseURL.$mediaURL.$value['path']);
$xmlObject->endElement(); //
}
}
$xmlObject->endElement(); //
$xmlObject->endElement(); //
// Write XML data to file...
writeXmlFile($xmlObject->outputMemory(true), $XML);
function writeXmlFile($contents, $file) {
$fh = fopen($file, 'w') or die("can't open file");
fwrite($fh, $contents);
}
function parseFileName($fileName) {
$input = explode(".",$fileName);
$noExt = $input[0];
return $noExt;
}
// Custom array ordering function for usort
// orders by REVERSE order (Biggest timestamp goes FIRST).
function cmp($a, $b)
{
return strcmp($b["modified"], $a["modified"]);
}
?>
The PHP script will scan a given directory for files with the extension "m4a" (or any other extension configured in the $fileExtension variable), it will order the files by their created date (in reverse order) and will generate a file called "podcast.xml" that you can access with iTunes on mac or PC, or you could use any other podcast client like Juice.
You should for example call the bash script "recorder" and call the php script "podcast", then chmod +x both files to make them executables, and then just run the bash script by typing:
./recorder
Obviously, the idea behind all this is that you should create a crontab entry to run the process automatically, in my case, it runs everyday at 12:00 AM and i did set the duration variable to 121 minutes (2 hours and a bit).
All the rest should be smooth and automatic if you configured correctly the initialization variables in both scripts.
![[Click here to see screenshot]](http://massanti.com/wp-content/uploads/2008/04/picture-7.png){kind=link}
![[Click here to see screenshot]](http://massanti.com/wp-content/uploads/2008/04/picture-6.png){kind=link}