<?php
/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org>               //
//  available at http://getid3.sourceforge.net                 //
//            or http://www.getid3.org                         //
/////////////////////////////////////////////////////////////////
//                                                             //
// /demo/demo.joinmp3.php - part of getID3()                   //
// Sample script for splicing two or more MP3s together into   //
// one file. Does not attempt to fix VBR header frames.        //
// See readme.txt for more details                             //
//                                                            ///
/////////////////////////////////////////////////////////////////


// sample usage:
// $FilenameOut   = 'combined.mp3';
// $FilenamesIn[] = 'file1.mp3';
// $FilenamesIn[] = 'file2.mp3';
// $FilenamesIn[] = 'file3.mp3';
//
// if (CombineMultipleMP3sTo($FilenameOut, $FilenamesIn)) {
//     echo 'Successfully copied '.implode(' + ', $FilenamesIn).' to '.$FilenameOut;
// } else {
//     echo 'Failed to copy '.implode(' + ', $FilenamesIn).' to '.$FilenameOut;
// }

function CombineMultipleMP3sTo($FilenameOut, $FilenamesIn) {

    foreach ($FilenamesIn as $nextinputfilename) {
        if (!is_readable($nextinputfilename)) {
            echo 'Cannot read "'.$nextinputfilename.'"<BR>';
            return false;
        }
    }
    if (!is_writeable($FilenameOut)) {
        echo 'Cannot write "'.$FilenameOut.'"<BR>';
        return false;
    }

    require_once('../getid3/getid3.php');
    if ($fp_output = @fopen($FilenameOut, 'wb')) {

        // Initialize getID3 engine
        $getID3 = new getID3;
        foreach ($FilenamesIn as $nextinputfilename) {

            $CurrentFileInfo = $getID3->analyze($nextinputfilename);
            if ($CurrentFileInfo['fileformat'] == 'mp3') {

                if ($fp_source = @fopen($nextinputfilename, 'rb')) {

                    $CurrentOutputPosition = ftell($fp_output);

                    // copy audio data from first file
                    fseek($fp_source, $CurrentFileInfo['avdataoffset'], SEEK_SET);
                    while (!feof($fp_source) && (ftell($fp_source) < $CurrentFileInfo['avdataend'])) {
                        fwrite($fp_output, fread($fp_source, 32768));
                    }
                    fclose($fp_source);

                    // trim post-audio data (if any) copied from first file that we don't need or want
                    $EndOfFileOffset = $CurrentOutputPosition + ($CurrentFileInfo['avdataend'] - $CurrentFileInfo['avdataoffset']);
                    fseek($fp_output, $EndOfFileOffset, SEEK_SET);
                    ftruncate($fp_output, $EndOfFileOffset);

                } else {

                    echo 'failed to open '.$nextinputfilename.' for reading';
                    fclose($fp_output);
                    return false;

                }

            } else {

                echo $nextinputfilename.' is not MP3 format';
                fclose($fp_output);
                return false;

            }

        }

    } else {

        echo 'failed to open '.$FilenameOut.' for writing';
        return false;

    }

    fclose($fp_output);
    return true;
}

?>