<?php

require_once H . 'sys/classes/PEAR.class.php';

define('PEAR_MP3_ID_FNO', 1);
define('PEAR_MP3_ID_RE ', 2);
define('PEAR_MP3_ID_TNF ', 3);
define('PEAR_MP3_ID_NOMP3 ', 4);

class MP3_Id {

    var $file = false;
    var $id3v1 = false;
    var $id3v11 = false;
    var $id3v2 = false;
    var $name = '';
    var $artists = '';
    var $album = '';
    var $year = '';
    var $comment = '';
    var $track = 0;
    var $genre = '';
    var $genreno = 255;
    var $studied = false;
    var $mpeg_ver = 0;
    var $layer = 0;
    var $bitrate = 0;
    var $crc = false;
    var $frequency = 0;
    var $encoding_type = 0;
    var $samples_per_frame = 0;
    var $samples = 0;
    var $musicsize = -1;
    var $frames = 0;
    var $quality = 0;
    var $padding = false;
    var $private = false;
    var $mode = '';
    var $copyright = false;
    var $original = false;
    var $emphasis = '';
    var $filesize = -1;
    var $frameoffset = -1;
    var $lengthh = false;
    var $length = false;
    var $lengths = false;
    var $error = false;
    var $debug = false;
    var $debugbeg = '<DIV STYLE="margin: 0.5 em; padding: 0.5 em; border-width: thin; border-color: black; border-style: solid">';
    var $debugend = '</DIV>';

    function MP3_Id($study = false) {
        if (defined('ID3_SHOW_DEBUG'))
            $this->debug = true;
        $this->study = ($study || defined('ID3_AUTO_STUDY'));
    }

    function read($file = "") {
        if ($this->debug)
            print($this->debugbeg . "id3('$file')<HR>\n");

        if (!empty($file))
            $this->file = $file;
        if ($this->debug)
            print($this->debugend);

        return $this->_read_v1();
    }

    function setTag($name, $value) {
        if (is_array($name)) {
            foreach ($name as $n => $v) {
                $this->$n = $v;
            }
        } else {
            $this->$name = $value;
        }
    }

    function getTag($name, $default = 0) {
        if (empty($this->$name)) {
            return $default;
        } else {
            return $this->$name;
        }
    }

    function write($v1 = true) {
        if ($this->debug)
            print($this->debugbeg . "write()<HR>\n");
        if ($v1) {
            $this->_write_v1();
        }
        if ($this->debug)
            print($this->debugend);
    }

    function study() {
        $this->studied = true;
        $this->_readframe();
    }

    function copy($from) {
        if ($this->debug)
            print($this->debugbeg . "copy(\$from)<HR>\n");
        $this->name = $from->name;
        $this->artists = $from->artists;
        $this->album = $from->album;
        $this->year = $from->year;
        $this->comment = $from->comment;
        $this->track = $from->track;
        $this->genre = $from->genre;
        $this->genreno = $from->genreno;
        if ($this->debug)
            print($this->debugend);
    }

    function remove($id3v1 = true, $id3v2 = true) {
        if ($this->debug)
            print($this->debugbeg . "remove()<HR>\n");

        if ($id3v1) {
            $this->_remove_v1();
        }

        if ($id3v2) {
            // TODO: write ID3v2 code
        }

        if ($this->debug)
            print($this->debugend);
    }

    function _read_v1() {
        if ($this->debug) {
            print($this->debugbeg . "_read_v1()<HR>\n");
        }

        if (!($f = @fopen($this->file, 'rb'))) {
            return PEAR::raiseError("Unable to open " . $this->file, PEAR_MP3_ID_FNO);
        }

        if (fseek($f, -128, SEEK_END) == -1) {
            return PEAR::raiseError('Unable to see to end - 128 of ' . $this->file, PEAR_MP3_ID_RE);
        }

        $r = fread($f, 128);
        fclose($f);

        if ($this->debug) {
            $unp = unpack('H*raw', $r);
            print_r($unp);
        }

        $id3tag = $this->_decode_v1($r);

        if (!PEAR::isError($id3tag)) {
            $this->id3v1 = true;

            $tmp = explode(Chr(0), $id3tag['NAME']);
            $this->name = $tmp[0];

            $tmp = explode(Chr(0), $id3tag['ARTISTS']);
            $this->artists = $tmp[0];

            $tmp = explode(Chr(0), $id3tag['ALBUM']);
            $this->album = $tmp[0];

            $tmp = explode(Chr(0), $id3tag['YEAR']);
            $this->year = $tmp[0];

            $tmp = explode(Chr(0), $id3tag['COMMENT']);
            $this->comment = $tmp[0];

            if (isset($id3tag['TRACK'])) {
                $this->id3v11 = true;
                $this->track = $id3tag['TRACK'];
            }

            $this->genreno = $id3tag['GENRENO'];
            $this->genre = $id3tag['GENRE'];
        } else {
            return $id3tag;
        }

        if ($this->debug)
            print($this->debugend);
    }

    function _decode_v1($rawtag) {
        if ($this->debug)
            print($this->debugbeg . "_decode_v1(\$rawtag)<HR>\n");

        if ($rawtag[125] == Chr(0) and $rawtag[126] != Chr(0)) {
            // ID3 v1.1
            $format = 'a3TAG/a30NAME/a30ARTISTS/a30ALBUM/a4YEAR/a28COMMENT/x1/C1TRACK/C1GENRENO';
        } else {
            // ID3 v1
            $format = 'a3TAG/a30NAME/a30ARTISTS/a30ALBUM/a4YEAR/a30COMMENT/C1GENRENO';
        }

        $id3tag = unpack($format, $rawtag);
        if ($this->debug)
            print_r($id3tag);

        if ($id3tag['TAG'] == 'TAG') {
            $id3tag['GENRE'] = $this->getgenre($id3tag['GENRENO']);
        } else {
            $id3tag = PEAR::raiseError('TAG not found', PEAR_MP3_ID_TNF);
        }
        if ($this->debug)
            print($this->debugend);
        return $id3tag;
    }

    function _write_v1() {
        if ($this->debug)
            print($this->debugbeg . "_write_v1()<HR>\n");

        $file = $this->file;

        if (!($f = @fopen($file, 'r+b'))) {
            return PEAR::raiseError("Unable to open " . $file, PEAR_MP3_ID_FNO);
        }

        if (fseek($f, -128, SEEK_END) == -1) {
//        $this->error = 'Unable to see to end - 128 of ' . $file;
            return PEAR::raiseError("Unable to see to end - 128 of " . $file, PEAR_MP3_ID_RE);
        }

        $this->genreno = $this->getgenreno($this->genre, $this->genreno);

        $newtag = $this->_encode_v1();

        $r = fread($f, 128);

        if (!PEAR::isError($this->_decode_v1($r))) {
            if (fseek($f, -128, SEEK_END) == -1) {
//        $this->error = 'Unable to see to end - 128 of ' . $file;
                return PEAR::raiseError("Unable to see to end - 128 of " . $file, PEAR_MP3_ID_RE);
            }
            fwrite($f, $newtag);
        } else {
            if (fseek($f, 0, SEEK_END) == -1) {
//        $this->error = 'Unable to see to end of ' . $file;
                return PEAR::raiseError("Unable to see to end of " . $file, PEAR_MP3_ID_RE);
            }
            fwrite($f, $newtag);
        }
        fclose($f);

        if ($this->debug)
            print($this->debugend);
    }

    function _encode_v1() {
        if ($this->debug)
            print($this->debugbeg . "_encode_v1()<HR>\n");

        if ($this->track) {
            // ID3 v1.1
            $id3pack = 'a3a30a30a30a4a28x1C1C1';
            $newtag = pack($id3pack, 'TAG', $this->name, $this->artists, $this->album, $this->year, $this->comment, $this->track, $this->genreno
            );
        } else {
            // ID3 v1
            $id3pack = 'a3a30a30a30a4a30C1';
            $newtag = pack($id3pack, 'TAG', $this->name, $this->artists, $this->album, $this->year, $this->comment, $this->genreno
            );
        }

        if ($this->debug) {
            print('id3pack: ' . $id3pack . "\n");
            $unp = unpack('H*new', $newtag);
            print_r($unp);
        }

        if ($this->debug)
            print($this->debugend);
        return $newtag;
    }

    function _remove_v1() {
        if ($this->debug)
            print($this->debugbeg . "_remove_v1()<HR>\n");

        $file = $this->file;

        if (!($f = fopen($file, 'r+b'))) {
            return PEAR::raiseError("Unable to open " . $file, PEAR_MP3_ID_FNO);
        }

        if (fseek($f, -128, SEEK_END) == -1) {
            return PEAR::raiseError('Unable to see to end - 128 of ' . $file, PEAR_MP3_ID_RE);
        }

        $r = fread($f, 128);

        $success = false;
        if (!PEAR::isError($this->_decode_v1($r))) {
            $size = filesize($this->file) - 128;
            if ($this->debug)
                print('size: old: ' . filesize($this->file));
            $success = ftruncate($f, $size);
            clearstatcache();
            if ($this->debug)
                print(' new: ' . filesize($this->file));
        }
        fclose($f);

        if ($this->debug)
            print($this->debugend);
        return $success;
    }

    function _readframe() {
        if ($this->debug)
            print($this->debugbeg . "_readframe()<HR>\n");

        $file = $this->file;

        if (!($f = fopen($file, 'rb'))) {
            if ($this->debug)
                print($this->debugend);
            return PEAR::raiseError("Unable to open " . $file, PEAR_MP3_ID_FNO);
        }

        $this->filesize = filesize($file);

        do {
            while (fread($f, 1) != Chr(255)) { // Find the first frame
                if ($this->debug)
                    echo "Find...\n";
                if (feof($f)) {
                    if ($this->debug)
                        print($this->debugend);
                    return PEAR::raiseError("No mpeg frame found", PEAR_MP3_ID_NOMP3);
                }
            }
            fseek($f, ftell($f) - 1); // back up one byte

            $frameoffset = ftell($f);

            $r = fread($f, 4);
            // Binary to Hex to a binary sting. ugly but best I can think of.
            // $bits = unpack('H*bits', $r);
            // $bits =  base_convert($bits['bits'],16,2);
            $bits = sprintf("%'08b%'08b%'08b%'08b", ord($r{0}), ord($r{1}), ord($r{2}), ord($r{3}));
        } while (!$bits[8] and ! $bits[9] and ! $bits[10]); // 1st 8 bits true from the while
        if ($this->debug)
            print('Bits: ' . $bits . "\n");

        $this->frameoffset = $frameoffset;

        // Detect VBR header
        if ($bits[11] == 0) {
            if (($bits[24] == 1) && ($bits[25] == 1)) {
                $vbroffset = 9; // MPEG 2.5 Mono
            } else {
                $vbroffset = 17; // MPEG 2.5 Stereo
            }
        } else if ($bits[12] == 0) {
            if (($bits[24] == 1) && ($bits[25] == 1)) {
                $vbroffset = 9; // MPEG 2 Mono
            } else {
                $vbroffset = 17; // MPEG 2 Stereo
            }
        } else {
            if (($bits[24] == 1) && ($bits[25] == 1)) {
                $vbroffset = 17; // MPEG 1 Mono
            } else {
                $vbroffset = 32; // MPEG 1 Stereo
            }
        }

        fseek($f, ftell($f) + $vbroffset);
        $r = fread($f, 4);

        switch ($r) {
            case 'Xing':
                $this->encoding_type = 'VBR';
            case 'Info':
                // Extract info from Xing header

                if ($this->debug)
                    print('Encoding Header: ' . $r . "\n");

                $r = fread($f, 4);
                $vbrbits = sprintf("%'08b", ord($r{3}));

                if ($this->debug)
                    print('XING Header Bits: ' . $vbrbits . "\n");

                if ($vbrbits[7] == 1) {
                    // Next 4 bytes contain number of frames
                    $r = fread($f, 4);
                    $this->frames = unpack('N', $r);
                    $this->frames = $this->frames[1];
                }

                if ($vbrbits[6] == 1) {
                    // Next 4 bytes contain number of bytes
                    $r = fread($f, 4);
                    $this->musicsize = unpack('N', $r);
                    $this->musicsize = $this->musicsize[1];
                }

                if ($vbrbits[5] == 1) {
                    // Next 100 bytes contain TOC entries, skip
                    fseek($f, ftell($f) + 100);
                }

                if ($vbrbits[4] == 1) {
                    // Next 4 bytes contain Quality Indicator
                    $r = fread($f, 4);
                    $this->quality = unpack('N', $r);
                    $this->quality = $this->quality[1];
                }

                break;

            case 'VBRI':
            default:
                if ($vbroffset != 32) {
                    // VBRI Header is fixed after 32 bytes, so maybe we are looking at the wrong place.
                    fseek($f, ftell($f) + 32 - $vbroffset);
                    $r = fread($f, 4);

                    if ($r != 'VBRI') {
                        $this->encoding_type = 'CBR';
                        break;
                    }
                } else {
                    $this->encoding_type = 'CBR';
                    break;
                }

                if ($this->debug)
                    print('Encoding Header: ' . $r . "\n");

                $this->encoding_type = 'VBR';

                // Next 2 bytes contain Version ID, skip
                fseek($f, ftell($f) + 2);

                // Next 2 bytes contain Delay, skip
                fseek($f, ftell($f) + 2);

                // Next 2 bytes contain Quality Indicator
                $r = fread($f, 2);
                $this->quality = unpack('n', $r);
                $this->quality = $this->quality[1];

                // Next 4 bytes contain number of bytes
                $r = fread($f, 4);
                $this->musicsize = unpack('N', $r);
                $this->musicsize = $this->musicsize[1];

                // Next 4 bytes contain number of frames
                $r = fread($f, 4);
                $this->frames = unpack('N', $r);
                $this->frames = $this->frames[1];
        }

        fclose($f);

        if ($bits[11] == 0) {
            $this->mpeg_ver = "2.5";
            $bitrates = array(
                '1' => array(0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0),
                '2' => array(0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0),
                '3' => array(0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0),
            );
        } else if ($bits[12] == 0) {
            $this->mpeg_ver = "2";
            $bitrates = array(
                '1' => array(0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0),
                '2' => array(0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0),
                '3' => array(0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0),
            );
        } else {
            $this->mpeg_ver = "1";
            $bitrates = array(
                '1' => array(0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 0),
                '2' => array(0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 0),
                '3' => array(0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0),
            );
        }
        if ($this->debug)
            print('MPEG' . $this->mpeg_ver . "\n");

        $layer = array(
            array(0, 3),
            array(2, 1),
        );
        $this->layer = $layer[$bits[13]][$bits[14]];
        if ($this->debug)
            print('layer: ' . $this->layer . "\n");

        if ($bits[15] == 0) {
            // It's backwards, if the bit is not set then it is protected.
            if ($this->debug)
                print("protected (crc)\n");
            $this->crc = true;
        }

        $bitrate = 0;
        if ($bits[16] == 1)
            $bitrate += 8;
        if ($bits[17] == 1)
            $bitrate += 4;
        if ($bits[18] == 1)
            $bitrate += 2;
        if ($bits[19] == 1)
            $bitrate += 1;
        $this->bitrate = $bitrates[$this->layer][$bitrate];

        $frequency = array(
            '1' => array(
                '0' => array(44100, 48000),
                '1' => array(32000, 0),
            ),
            '2' => array(
                '0' => array(22050, 24000),
                '1' => array(16000, 0),
            ),
            '2.5' => array(
                '0' => array(11025, 12000),
                '1' => array(8000, 0),
            ),
        );
        $this->frequency = $frequency[$this->mpeg_ver][$bits[20]][$bits[21]];

        $this->padding = $bits[22];
        $this->private = $bits[23];

        $mode = array(
            array('Stereo', 'Joint Stereo'),
            array('Dual Channel', 'Mono'),
        );
        $this->mode = $mode[$bits[24]][$bits[25]];

        // XXX: I dunno what the mode extension is for bits 26,27

        $this->copyright = $bits[28];
        $this->original = $bits[29];

        $emphasis = array(
            array('none', '50/15ms'),
            array('', 'CCITT j.17'),
        );
        $this->emphasis = $emphasis[$bits[30]][$bits[31]];

        $samplesperframe = array(
            '1' => array(
                '1' => 384,
                '2' => 1152,
                '3' => 1152
            ),
            '2' => array(
                '1' => 384,
                '2' => 1152,
                '3' => 576
            ),
            '2.5' => array(
                '1' => 384,
                '2' => 1152,
                '3' => 576
            ),
        );
        $this->samples_per_frame = $samplesperframe[$this->mpeg_ver][$this->layer];

        if ($this->encoding_type != 'VBR') {
            if ($this->bitrate == 0) {
                $s = -1;
            } else {
                $s = ((8 * filesize($this->file)) / 1000) / $this->bitrate;
            }
            $this->length = sprintf('%02d:%02d', floor($s / 60), floor($s - (floor($s / 60) * 60)));
            $this->lengthh = sprintf('%02d:%02d:%02d', floor($s / 3600), floor($s / 60), floor($s - (floor($s / 60) * 60)));
            $this->lengths = (int) $s;

            $this->samples = ceil($this->lengths * $this->frequency);
            if (0 != $this->samples_per_frame) {
                $this->frames = ceil($this->samples / $this->samples_per_frame);
            } else {
                $this->frames = 0;
            }
            $this->musicsize = ceil($this->lengths * $this->bitrate * 1000 / 8);
        } else {
            $this->samples = $this->samples_per_frame * $this->frames;
            $s = $this->samples / $this->frequency;

            $this->length = sprintf('%02d:%02d', floor($s / 60), floor($s - (floor($s / 60) * 60)));
            $this->lengthh = sprintf('%02d:%02d:%02d', floor($s / 3600), floor($s / 60), floor($s - (floor($s / 60) * 60)));
            $this->lengths = (int) $s;

            $this->bitrate = (int) (($this->musicsize / $s) * 8 / 1000);
        }

        if ($this->debug)
            print($this->debugend);
    }

    function getGenre($genreno) {
        if ($this->debug)
            print($this->debugbeg . "getgenre($genreno)<HR>\n");

        $genres = $this->genres();
        if (isset($genres[$genreno])) {
            $genre = $genres[$genreno];
            if ($this->debug)
                print($genre . "\n");
        } else {
            $genre = '';
        }

        if ($this->debug)
            print($this->debugend);
        return $genre;
    }

    function getGenreNo($genre, $default = 0xff) {
        if ($this->debug)
            print($this->debugbeg . "getgenreno('$genre',$default)<HR>\n");

        $genres = $this->genres();
        $genreno = false;
        if ($genre) {
            foreach ($genres as $no => $name) {
                if (strtolower($genre) == strtolower($name)) {
                    if ($this->debug)
                        print("$no:'$name' == '$genre'");
                    $genreno = $no;
                }
            }
        }
        if ($genreno === false)
            $genreno = $default;
        if ($this->debug)
            print($this->debugend);
        return $genreno;
    }

    function genres() {
        return array(
            0 => 'Blues',
            1 => 'Classic Rock',
            2 => 'Country',
            3 => 'Dance',
            4 => 'Disco',
            5 => 'Funk',
            6 => 'Grunge',
            7 => 'Hip-Hop',
            8 => 'Jazz',
            9 => 'Metal',
            10 => 'New Age',
            11 => 'Oldies',
            12 => 'Other',
            13 => 'Pop',
            14 => 'R&B',
            15 => 'Rap',
            16 => 'Reggae',
            17 => 'Rock',
            18 => 'Techno',
            19 => 'Industrial',
            20 => 'Alternative',
            21 => 'Ska',
            22 => 'Death Metal',
            23 => 'Pranks',
            24 => 'Soundtrack',
            25 => 'Euro-Techno',
            26 => 'Ambient',
            27 => 'Trip-Hop',
            28 => 'Vocal',
            29 => 'Jazz+Funk',
            30 => 'Fusion',
            31 => 'Trance',
            32 => 'Classical',
            33 => 'Instrumental',
            34 => 'Acid',
            35 => 'House',
            36 => 'Game',
            37 => 'Sound Clip',
            38 => 'Gospel',
            39 => 'Noise',
            40 => 'Alternative Rock',
            41 => 'Bass',
            42 => 'Soul',
            43 => 'Punk',
            44 => 'Space',
            45 => 'Meditative',
            46 => 'Instrumental Pop',
            47 => 'Instrumental Rock',
            48 => 'Ethnic',
            49 => 'Gothic',
            50 => 'Darkwave',
            51 => 'Techno-Industrial',
            52 => 'Electronic',
            53 => 'Pop-Folk',
            54 => 'Eurodance',
            55 => 'Dream',
            56 => 'Southern Rock',
            57 => 'Comedy',
            58 => 'Cult',
            59 => 'Gangsta',
            60 => 'Top 40',
            61 => 'Christian Rap',
            62 => 'Pop/Funk',
            63 => 'Jungle',
            64 => 'Native US',
            65 => 'Cabaret',
            66 => 'New Wave',
            67 => 'Psychadelic',
            68 => 'Rave',
            69 => 'Showtunes',
            70 => 'Trailer',
            71 => 'Lo-Fi',
            72 => 'Tribal',
            73 => 'Acid Punk',
            74 => 'Acid Jazz',
            75 => 'Polka',
            76 => 'Retro',
            77 => 'Musical',
            78 => 'Rock & Roll',
            79 => 'Hard Rock',
            80 => 'Folk',
            81 => 'Folk-Rock',
            82 => 'National Folk',
            83 => 'Swing',
            84 => 'Fast Fusion',
            85 => 'Bebob',
            86 => 'Latin',
            87 => 'Revival',
            88 => 'Celtic',
            89 => 'Bluegrass',
            90 => 'Avantgarde',
            91 => 'Gothic Rock',
            92 => 'Progressive Rock',
            93 => 'Psychedelic Rock',
            94 => 'Symphonic Rock',
            95 => 'Slow Rock',
            96 => 'Big Band',
            97 => 'Chorus',
            98 => 'Easy Listening',
            99 => 'Acoustic',
            100 => 'Humour',
            101 => 'Speech',
            102 => 'Chanson',
            103 => 'Opera',
            104 => 'Chamber Music',
            105 => 'Sonata',
            106 => 'Symphony',
            107 => 'Booty Bass',
            108 => 'Primus',
            109 => 'Porn Groove',
            110 => 'Satire',
            111 => 'Slow Jam',
            112 => 'Club',
            113 => 'Tango',
            114 => 'Samba',
            115 => 'Folklore',
            116 => 'Ballad',
            117 => 'Power Ballad',
            118 => 'Rhytmic Soul',
            119 => 'Freestyle',
            120 => 'Duet',
            121 => 'Punk Rock',
            122 => 'Drum Solo',
            123 => 'Acapella',
            124 => 'Euro-House',
            125 => 'Dance Hall',
            126 => 'Goa',
            127 => 'Drum & Bass',
            128 => 'Club-House',
            129 => 'Hardcore',
            130 => 'Terror',
            131 => 'Indie',
            132 => 'BritPop',
            133 => 'Negerpunk',
            134 => 'Polsk Punk',
            135 => 'Beat',
            136 => 'Christian Gangsta Rap',
            137 => 'Heavy Metal',
            138 => 'Black Metal',
            139 => 'Crossover',
            140 => 'Contemporary Christian',
            141 => 'Christian Rock',
            142 => 'Merengue',
            143 => 'Salsa',
            144 => 'Trash Metal',
            145 => 'Anime',
            146 => 'Jpop',
            147 => 'Synthpop'
        );
    }

}
