Automatically trimming an mp3 in PHP

I used PHP MP3 for my project.

<?php
//Extract 30 seconds starting after 10 seconds.
$path = 'path.mp3';
$mp3 = new PHPMP3($path);
$mp3_1 = $mp3->extract(10,30);
$mp3_1->save('newpath.mp3');
?>

For your case you can use extract(0,30) or extract(30,60).

I put together a script that outputs a 30 second clip of an MP3 file on the fly. If you're looking to save the file, one of the other options using a class/library will probably be best. But, if you just want to play/download the preview, on the fly might be better. It will definitely save you hard drive space.

Check it out at http://www.stephenwalcher.com/2013/06/17/how-to-extract-and-play-part-of-an-mp3-in-php/.

Here's the code, but a deeper explanation can be found on my blog.

$getID3 = new getID3();

$id3_info = $getID3->analyze($filename);

list($t_min, $t_sec) = explode(':', $id3_info['playtime_string']);
$time = ($t_min * 60) + $t_sec;

$preview = $time / 30; // Preview time of 30 seconds

$handle = fopen($filename, 'r');
$content = fread($handle, filesize($filename));

$length = strlen($content);

if (!$session->IsLoggedIn()) {
    $length = round(strlen($content) / $preview);
    $content = substr($content, $length / 3 /* Start extraction ~10 seconds in */, $length);
}

header("Content-Type: {$id3_info['mime_type']}");
header("Content-Length: {$length}");
print $content;

You could try the MP3 Class on PHPClasses. It features the following example:

require_once './class.mp3.php';
$mp3 = new mp3;
$mp3->cut_mp3('input.mp3', 'output.mp3', 0, -1, 'frame', false);

In this case, the 'frame' can be substituted with 'second' to base the cut on a time-frame.