CaffGeek/MBACNationals

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Web.Admin/2014/wordpress/wp-includes/ID3/module.audio.ogg.php

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<?php
/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org>               //
//  available at http://getid3.sourceforge.net                 //
//            or http://www.getid3.org                         //
/////////////////////////////////////////////////////////////////
// See readme.txt for more details                             //
/////////////////////////////////////////////////////////////////
//                                                             //
// module.audio.ogg.php                                        //
// module for analyzing Ogg Vorbis, OggFLAC and Speex files    //
// dependencies: module.audio.flac.php                         //
//                                                            ///
/////////////////////////////////////////////////////////////////

getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio.flac.php', __FILE__, true);

class getid3_ogg extends getid3_handler
{
    // http://xiph.org/vorbis/doc/Vorbis_I_spec.html
    public function Analyze() {
        $info = &$this->getid3->info;

        $info['fileformat'] = 'ogg';

        // Warn about illegal tags - only vorbiscomments are allowed
        if (isset($info['id3v2'])) {
            $info['warning'][] = 'Illegal ID3v2 tag present.';
        }
        if (isset($info['id3v1'])) {
            $info['warning'][] = 'Illegal ID3v1 tag present.';
        }
        if (isset($info['ape'])) {
            $info['warning'][] = 'Illegal APE tag present.';
        }


        // Page 1 - Stream Header

        $this->fseek($info['avdataoffset']);

        $oggpageinfo = $this->ParseOggPageHeader();
        $info['ogg']['pageheader'][$oggpageinfo['page_seqno']] = $oggpageinfo;

        if ($this->ftell() >= $this->getid3->fread_buffer_size()) {
            $info['error'][] = 'Could not find start of Ogg page in the first '.$this->getid3->fread_buffer_size().' bytes (this might not be an Ogg-Vorbis file?)';
            unset($info['fileformat']);
            unset($info['ogg']);
            return false;
        }

        $filedata = $this->fread($oggpageinfo['page_length']);
        $filedataoffset = 0;

        if (substr($filedata, 0, 4) == 'fLaC') {

            $info['audio']['dataformat']   = 'flac';
            $info['audio']['bitrate_mode'] = 'vbr';
            $info['audio']['lossless']     = true;

        } elseif (substr($filedata, 1, 6) == 'vorbis') {

            $this->ParseVorbisPageHeader($filedata, $filedataoffset, $oggpageinfo);

        } elseif (substr($filedata, 0, 8) == 'Speex   ') {

            // http://www.speex.org/manual/node10.html

            $info['audio']['dataformat']   = 'speex';
            $info['mime_type']             = 'audio/speex';
            $info['audio']['bitrate_mode'] = 'abr';
            $info['audio']['lossless']     = false;

            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['speex_string']           =                              substr($filedata, $filedataoffset, 8); // hard-coded to 'Speex   '
            $filedataoffset += 8;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['speex_version']          =                              substr($filedata, $filedataoffset, 20);
            $filedataoffset += 20;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['speex_version_id']       = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['header_size']            = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['rate']                   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['mode']                   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['mode_bitstream_version'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['nb_channels']            = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['bitrate']                = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['framesize']              = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['vbr']                    = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['frames_per_packet']      = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['extra_headers']          = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['reserved1']              = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;
            $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['reserved2']              = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
            $filedataoffset += 4;

            $info['speex']['speex_version'] = trim($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['speex_version']);
            $info['speex']['sample_rate']   = $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['rate'];
            $info['speex']['channels']      = $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['nb_channels'];
            $info['speex']['vbr']           = (bool) $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['vbr'];
            $info['speex']['band_type']     = $this->SpeexBandModeLookup($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['mode']);

            $info['audio']['sample_rate']   = $info['speex']['sample_rate'];
            $info['audio']['channels']      = $info['speex']['channels'];
            if ($info['speex']['vbr']) {
                $info['audio']['bitrate_mode'] = 'vbr';
            }


        } elseif (substr($filedata, 0, 8) == "fishead\x00") {

            // Ogg Skeleton version 3.0 Format Specification
            // http://xiph.org/ogg/doc/skeleton.html
            $filedataoffset += 8;
            $info['ogg']['skeleton']['fishead']['raw']['version_major']                = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  2));
            $filedataoffset += 2;
            $info['ogg']['skeleton']['fishead']['raw']['version_minor']                = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  2));
            $filedataoffset += 2;
            $info['ogg']['skeleton']['fishead']['raw']['presentationtime_numerator']   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
            $filedataoffset += 8;
            $info['ogg']['skeleton']['fishead']['raw']['presentationtime_denominator'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
            $filedataoffset += 8;
            $info['ogg']['skeleton']['fishead']['raw']['basetime_numerator']           = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
            $filedataoffset += 8;
            $info['ogg']['skeleton']['fishead']['raw']['basetime_denominator']         = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
            $filedataoffset += 8;
            $info['ogg']['skeleton']['fishead']['raw']['utc']                          = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 20));
            $filedataoffset += 20;

            $info['ogg']['skeleton']['fishead']['version']          = $info['ogg']['skeleton']['fishead']['raw']['version_major'].'.'.$info['ogg']['skeleton']['fishead']['raw']['version_minor'];
            $info['ogg']['skeleton']['fishead']['presentationtime'] = $info['ogg']['skeleton']['fishead']['raw']['presentationtime_numerator'] / $info['ogg']['skeleton']['fishead']['raw']['presentationtime_denominator'];
            $info['ogg']['skeleton']['fishead']['basetime']         = $info['ogg']['skeleton']['fishead']['raw']['basetime_numerator']         / $info['ogg']['skeleton']['fishead']['raw']['basetime_denominator'];
            $info['ogg']['skeleton']['fishead']['utc']              = $info['ogg']['skeleton']['fishead']['raw']['utc'];


            $counter = 0;
            do {
                $oggpageinfo = $this->ParseOggPageHeader();
                $info['ogg']['pageheader'][$oggpageinfo['page_seqno'].'.'.$counter++] = $oggpageinfo;
                $filedata = $this->fread($oggpageinfo['page_length']);
                $this->fseek($oggpageinfo['page_end_offset']);

                if (substr($filedata, 0, 8) == "fisbone\x00") {

                    $filedataoffset = 8;
                    $info['ogg']['skeleton']['fisbone']['raw']['message_header_offset']   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  4));
                    $filedataoffset += 4;
                    $info['ogg']['skeleton']['fisbone']['raw']['serial_number']           = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  4));
                    $filedataoffset += 4;
                    $info['ogg']['skeleton']['fisbone']['raw']['number_header_packets']   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  4));
                    $filedataoffset += 4;
                    $info['ogg']['skeleton']['fisbone']['raw']['granulerate_numerator']   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
                    $filedataoffset += 8;
                    $info['ogg']['skeleton']['fisbone']['raw']['granulerate_denominator'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
                    $filedataoffset += 8;
                    $info['ogg']['skeleton']['fisbone']['raw']['basegranule']             = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
                    $filedataoffset += 8;
                    $info['ogg']['skeleton']['fisbone']['raw']['preroll']                 = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  4));
                    $filedataoffset += 4;
                    $info['ogg']['skeleton']['fisbone']['raw']['granuleshift']            = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  1));
                    $filedataoffset += 1;
                    $info['ogg']['skeleton']['fisbone']['raw']['padding']                 =                              substr($filedata, $filedataoffset,  3);
                    $filedataoffset += 3;

                } elseif (substr($filedata, 1, 6) == 'theora') {

                    $info['video']['dataformat'] = 'theora';
                    $info['error'][] = 'Ogg Theora not correctly handled in this version of getID3 ['.$this->getid3->version().']';
                    //break;

                } elseif (substr($filedata, 1, 6) == 'vorbis') {

                    $this->ParseVorbisPageHeader($filedata, $filedataoffset, $oggpageinfo);

                } else {
                    $info['error'][] = 'unexpected';
                    //break;
                }
            //} while ($oggpageinfo['page_seqno'] == 0);
            } while (($oggpageinfo['page_seqno'] == 0) && (substr($filedata, 0, 8) != "fisbone\x00"));

            $this->fseek($oggpageinfo['page_start_offset']);

            $info['error'][] = 'Ogg Skeleton not correctly handled in this version of getID3 ['.$this->getid3->version().']';
            //return false;

        } else {

            $info['error'][] = 'Expecting either "Speex   " or "vorbis" identifier strings, found "'.substr($filedata, 0, 8).'"';
            unset($info['ogg']);
            unset($info['mime_type']);
            return false;

        }

        // Page 2 - Comment Header
        $oggpageinfo = $this->ParseOggPageHeader();
        $info['ogg']['pageheader'][$oggpageinfo['page_seqno']] = $oggpageinfo;

        switch ($info['audio']['dataformat']) {
            case 'vorbis':
                $filedata = $this->fread($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_length']);
                $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['packet_type'] = getid3_lib::LittleEndian2Int(substr($filedata, 0, 1));
                $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['stream_type'] =                              substr($filedata, 1, 6); // hard-coded to 'vorbis'

                $this->ParseVorbisComments();
                break;

            case 'flac':
                $flac = new getid3_flac($this->getid3);
                if (!$flac->parseMETAdata()) {
                    $info['error'][] = 'Failed to parse FLAC headers';
                    return false;
                }
                unset($flac);
                break;

            case 'speex':
                $this->fseek($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_length'], SEEK_CUR);
                $this->ParseVorbisComments();
                break;
        }


        // Last Page - Number of Samples
        if (!getid3_lib::intValueSupported($info['avdataend'])) {

            $info['warning'][] = 'Unable to parse Ogg end chunk file (PHP does not support file operations beyond '.round(PHP_INT_MAX / 1073741824).'GB)';

        } else {

            $this->fseek(max($info['avdataend'] - $this->getid3->fread_buffer_size(), 0));
            $LastChunkOfOgg = strrev($this->fread($this->getid3->fread_buffer_size()));
            if ($LastOggSpostion = strpos($LastChunkOfOgg, 'SggO')) {
                $this->fseek($info['avdataend'] - ($LastOggSpostion + strlen('SggO')));
                $info['avdataend'] = $this->ftell();
                $info['ogg']['pageheader']['eos'] = $this->ParseOggPageHeader();
                $info['ogg']['samples']   = $info['ogg']['pageheader']['eos']['pcm_abs_position'];
                if ($info['ogg']['samples'] == 0) {
                    $info['error'][] = 'Corrupt Ogg file: eos.number of samples == zero';
                    return false;
                }
                if (!empty($info['audio']['sample_rate'])) {
                    $info['ogg']['bitrate_average'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / ($info['ogg']['samples'] / $info['audio']['sample_rate']);
                }
            }

        }

        if (!empty($info['ogg']['bitrate_average'])) {
            $info['audio']['bitrate'] = $info['ogg']['bitrate_average'];
        } elseif (!empty($info['ogg']['bitrate_nominal'])) {
            $info['audio']['bitrate'] = $info['ogg']['bitrate_nominal'];
        } elseif (!empty($info['ogg']['bitrate_min']) && !empty($info['ogg']['bitrate_max'])) {
            $info['audio']['bitrate'] = ($info['ogg']['bitrate_min'] + $info['ogg']['bitrate_max']) / 2;
        }
        if (isset($info['audio']['bitrate']) && !isset($info['playtime_seconds'])) {
            if ($info['audio']['bitrate'] == 0) {
                $info['error'][] = 'Corrupt Ogg file: bitrate_audio == zero';
                return false;
            }
            $info['playtime_seconds'] = (float) ((($info['avdataend'] - $info['avdataoffset']) * 8) / $info['audio']['bitrate']);
        }

        if (isset($info['ogg']['vendor'])) {
            $info['audio']['encoder'] = preg_replace('/^Encoded with /', '', $info['ogg']['vendor']);

            // Vorbis only
            if ($info['audio']['dataformat'] == 'vorbis') {

                // Vorbis 1.0 starts with Xiph.Org
                if  (preg_match('/^Xiph.Org/', $info['audio']['encoder'])) {

                    if ($info['audio']['bitrate_mode'] == 'abr') {

                        // Set -b 128 on abr files
                        $info['audio']['encoder_options'] = '-b '.round($info['ogg']['bitrate_nominal'] / 1000);

                    } elseif (($info['audio']['bitrate_mode'] == 'vbr') && ($info['audio']['channels'] == 2) && ($info['audio']['sample_rate'] >= 44100) && ($info['audio']['sample_rate'] <= 48000)) {
                        // Set -q N on vbr files
                        $info['audio']['encoder_options'] = '-q '.$this->get_quality_from_nominal_bitrate($info['ogg']['bitrate_nominal']);

                    }
                }

                if (empty($info['audio']['encoder_options']) && !empty($info['ogg']['bitrate_nominal'])) {
                    $info['audio']['encoder_options'] = 'Nominal bitrate: '.intval(round($info['ogg']['bitrate_nominal'] / 1000)).'kbps';
                }
            }
        }

        return true;
    }

    public function ParseVorbisPageHeader(&$filedata, &$filedataoffset, &$oggpageinfo) {
        $info = &$this->getid3->info;
        $info['audio']['dataformat'] = 'vorbis';
        $info['audio']['lossless']   = false;

        $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['packet_type'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
        $filedataoffset += 1;
        $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['stream_type'] = substr($filedata, $filedataoffset, 6); // hard-coded to 'vorbis'
        $filedataoffset += 6;
        $info['ogg']['bitstreamversion'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
        $filedataoffset += 4;
        $info['ogg']['numberofchannels'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
        $filedataoffset += 1;
        $info['audio']['channels']       = $info['ogg']['numberofchannels'];
        $info['ogg']['samplerate']       = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
        $filedataoffset += 4;
        if ($info['ogg']['samplerate'] == 0) {
            $info['error'][] = 'Corrupt Ogg file: sample rate == zero';
            return false;
        }
        $info['audio']['sample_rate']    = $info['ogg']['samplerate'];
        $info['ogg']['samples']          = 0; // filled in later
        $info['ogg']['bitrate_average']  = 0; // filled in later
        $info['ogg']['bitrate_max']      = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
        $filedataoffset += 4;
        $info['ogg']['bitrate_nominal']  = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
        $filedataoffset += 4;
        $info['ogg']['bitrate_min']      = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
        $filedataoffset += 4;
        $info['ogg']['blocksize_small']  = pow(2,  getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1)) & 0x0F);
        $info['ogg']['blocksize_large']  = pow(2, (getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1)) & 0xF0) >> 4);
        $info['ogg']['stop_bit']         = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1)); // must be 1, marks end of packet

        $info['audio']['bitrate_mode'] = 'vbr'; // overridden if actually abr
        if ($info['ogg']['bitrate_max'] == 0xFFFFFFFF) {
            unset($info['ogg']['bitrate_max']);
            $info['audio']['bitrate_mode'] = 'abr';
        }
        if ($info['ogg']['bitrate_nominal'] == 0xFFFFFFFF) {
            unset($info['ogg']['bitrate_nominal']);
        }
        if ($info['ogg']['bitrate_min'] == 0xFFFFFFFF) {
            unset($info['ogg']['bitrate_min']);
            $info['audio']['bitrate_mode'] = 'abr';
        }
        return true;
    }

    public function ParseOggPageHeader() {
        // http://xiph.org/ogg/vorbis/doc/framing.html
        $oggheader['page_start_offset'] = $this->ftell(); // where we started from in the file

        $filedata = $this->fread($this->getid3->fread_buffer_size());
        $filedataoffset = 0;
        while ((substr($filedata, $filedataoffset++, 4) != 'OggS')) {
            if (($this->ftell() - $oggheader['page_start_offset']) >= $this->getid3->fread_buffer_size()) {
                // should be found before here
                return false;
            }
            if ((($filedataoffset + 28) > strlen($filedata)) || (strlen($filedata) < 28)) {
                if ($this->feof() || (($filedata .= $this->fread($this->getid3->fread_buffer_size())) === false)) {
                    // get some more data, unless eof, in which case fail
                    return false;
                }
            }
        }
        $filedataoffset += strlen('OggS') - 1; // page, delimited by 'OggS'

        $oggheader['stream_structver']  = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
        $filedataoffset += 1;
        $oggheader['flags_raw']         = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
        $filedataoffset += 1;
        $oggheader['flags']['fresh']    = (bool) ($oggheader['flags_raw'] & 0x01); // fresh packet
        $oggheader['flags']['bos']      = (bool) ($oggheader['flags_raw'] & 0x02); // first page of logical bitstream (bos)
        $oggheader['flags']['eos']      = (bool) ($oggheader['flags_raw'] & 0x04); // last page of logical bitstream (eos)

        $oggheader['pcm_abs_position']  = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 8));
        $filedataoffset += 8;
        $oggheader['stream_serialno']   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
        $filedataoffset += 4;
        $oggheader['page_seqno']        = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
        $filedataoffset += 4;
        $oggheader['page_checksum']     = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
        $filedataoffset += 4;
        $oggheader['page_segments']     = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
        $filedataoffset += 1;
        $oggheader['page_length'] = 0;
        for ($i = 0; $i < $oggheader['page_segments']; $i++) {
            $oggheader['segment_table'][$i] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
            $filedataoffset += 1;
            $oggheader['page_length'] += $oggheader['segment_table'][$i];
        }
        $oggheader['header_end_offset'] = $oggheader['page_start_offset'] + $filedataoffset;
        $oggheader['page_end_offset']   = $oggheader['header_end_offset'] + $oggheader['page_length'];
        $this->fseek($oggheader['header_end_offset']);

        return $oggheader;
    }

    // http://xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-810005
    public function ParseVorbisComments() {
        $info = &$this->getid3->info;

        $OriginalOffset = $this->ftell();
        $commentdataoffset = 0;
        $VorbisCommentPage = 1;

        switch ($info['audio']['dataformat']) {
            case 'vorbis':
            case 'speex':
                $CommentStartOffset = $info['ogg']['pageheader'][$VorbisCommentPage]['page_start_offset'];  // Second Ogg page, after header block
                $this->fseek($CommentStartOffset);
                $commentdataoffset = 27 + $info['ogg']['pageheader'][$VorbisCommentPage]['page_segments'];
                $commentdata = $this->fread(self::OggPageSegmentLength($info['ogg']['pageheader'][$VorbisCommentPage], 1) + $commentdataoffset);

                if ($info['audio']['dataformat'] == 'vorbis') {
                    $commentdataoffset += (strlen('vorbis') + 1);
                }
                break;

            case 'flac':
                $CommentStartOffset = $info['flac']['VORBIS_COMMENT']['raw']['offset'] + 4;
                $this->fseek($CommentStartOffset);
                $commentdata = $this->fread($info['flac']['VORBIS_COMMENT']['raw']['block_length']);
                break;

            default:
                return false;
        }

        $VendorSize = getid3_lib::LittleEndian2Int(substr($commentdata, $commentdataoffset, 4));
        $commentdataoffset += 4;

        $info['ogg']['vendor'] = substr($commentdata, $commentdataoffset, $VendorSize);
        $commentdataoffset += $VendorSize;

        $CommentsCount = getid3_lib::LittleEndian2Int(substr($commentdata, $commentdataoffset, 4));
        $commentdataoffset += 4;
        $info['avdataoffset'] = $CommentStartOffset + $commentdataoffset;

        $basicfields = array('TITLE', 'ARTIST', 'ALBUM', 'TRACKNUMBER', 'GENRE', 'DATE', 'DESCRIPTION', 'COMMENT');
        $ThisFileInfo_ogg_comments_raw = &$info['ogg']['comments_raw'];
        for ($i = 0; $i < $CommentsCount; $i++) {

            $ThisFileInfo_ogg_comments_raw[$i]['dataoffset'] = $CommentStartOffset + $commentdataoffset;

            if ($this->ftell() < ($ThisFileInfo_ogg_comments_raw[$i]['dataoffset'] + 4)) {
                if ($oggpageinfo = $this->ParseOggPageHeader()) {
                    $info['ogg']['pageheader'][$oggpageinfo['page_seqno']] = $oggpageinfo;

                    $VorbisCommentPage++;

                    // First, save what we haven't read yet
                    $AsYetUnusedData = substr($commentdata, $commentdataoffset);

                    // Then take that data off the end
                    $commentdata     = substr($commentdata, 0, $commentdataoffset);

                    // Add [headerlength] bytes of dummy data for the Ogg Page Header, just to keep absolute offsets correct
                    $commentdata .= str_repeat("\x00", 27 + $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_segments']);
                    $commentdataoffset += (27 + $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_segments']);

                    // Finally, stick the unused data back on the end
                    $commentdata .= $AsYetUnusedData;

                    //$commentdata .= $this->fread($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_length']);
                    $commentdata .= $this->fread($this->OggPageSegmentLength($info['ogg']['pageheader'][$VorbisCommentPage], 1));
                }

            }
            $ThisFileInfo_ogg_comments_raw[$i]['size'] = getid3_lib::LittleEndian2Int(substr($commentdata, $commentdataoffset, 4));

            // replace avdataoffset with position just after the last vorbiscomment
            $info['avdataoffset'] = $ThisFileInfo_ogg_comments_raw[$i]['dataoffset'] + $ThisFileInfo_ogg_comments_raw[$i]['size'] + 4;

            $commentdataoffset += 4;
            while ((strlen($commentdata) - $commentdataoffset) < $ThisFileInfo_ogg_comments_raw[$i]['size']) {
                if (($ThisFileInfo_ogg_comments_raw[$i]['size'] > $info['avdataend']) || ($ThisFileInfo_ogg_comments_raw[$i]['size'] < 0)) {
                    $info['warning'][] = 'Invalid Ogg comment size (comment #'.$i.', claims to be '.number_format($ThisFileInfo_ogg_comments_raw[$i]['size']).' bytes) - aborting reading comments';
                    break 2;
                }

                $VorbisCommentPage++;

                $oggpageinfo = $this->ParseOggPageHeader();
                $info['ogg']['pageheader'][$oggpageinfo['page_seqno']] = $oggpageinfo;

                // First, save what we haven't read yet
                $AsYetUnusedData = substr($commentdata, $commentdataoffset);

                // Then take that data off the end
                $commentdata     = substr($commentdata, 0, $commentdataoffset);

                // Add [headerlength] bytes of dummy data for the Ogg Page Header, just to keep absolute offsets correct
                $commentdata .= str_repeat("\x00", 27 + $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_segments']);
                $commentdataoffset += (27 + $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_segments']);

                // Finally, stick the unused data back on the end
                $commentdata .= $AsYetUnusedData;

                //$commentdata .= $this->fread($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_length']);
                if (!isset($info['ogg']['pageheader'][$VorbisCommentPage])) {
                    $info['warning'][] = 'undefined Vorbis Comment page "'.$VorbisCommentPage.'" at offset '.$this->ftell();
                    break;
                }
                $readlength = self::OggPageSegmentLength($info['ogg']['pageheader'][$VorbisCommentPage], 1);
                if ($readlength <= 0) {
                    $info['warning'][] = 'invalid length Vorbis Comment page "'.$VorbisCommentPage.'" at offset '.$this->ftell();
                    break;
                }
                $commentdata .= $this->fread($readlength);

                //$filebaseoffset += $oggpageinfo['header_end_offset'] - $oggpageinfo['page_start_offset'];
            }
            $ThisFileInfo_ogg_comments_raw[$i]['offset'] = $commentdataoffset;
            $commentstring = substr($commentdata, $commentdataoffset, $ThisFileInfo_ogg_comments_raw[$i]['size']);
            $commentdataoffset += $ThisFileInfo_ogg_comments_raw[$i]['size'];

            if (!$commentstring) {

                // no comment?
                $info['warning'][] = 'Blank Ogg comment ['.$i.']';

            } elseif (strstr($commentstring, '=')) {

                $commentexploded = explode('=', $commentstring, 2);
                $ThisFileInfo_ogg_comments_raw[$i]['key']   = strtoupper($commentexploded[0]);
                $ThisFileInfo_ogg_comments_raw[$i]['value'] = (isset($commentexploded[1]) ? $commentexploded[1] : '');

                if ($ThisFileInfo_ogg_comments_raw[$i]['key'] == 'METADATA_BLOCK_PICTURE') {

                    // http://wiki.xiph.org/VorbisComment#METADATA_BLOCK_PICTURE
                    // The unencoded format is that of the FLAC picture block. The fields are stored in big endian order as in FLAC, picture data is stored according to the relevant standard.
                    // http://flac.sourceforge.net/format.html#metadata_block_picture
                    $flac = new getid3_flac($this->getid3);
                    $flac->setStringMode(base64_decode($ThisFileInfo_ogg_comments_raw[$i]['value']));
                    $flac->parsePICTURE();
                    $info['ogg']['comments']['picture'][] = $flac->getid3->info['flac']['PICTURE'][0];
                    unset($flac);

                } elseif ($ThisFileInfo_ogg_comments_raw[$i]['key'] == 'COVERART') {

                    $data = base64_decode($ThisFileInfo_ogg_comments_raw[$i]['value']);
                    $this->notice('Found deprecated COVERART tag, it should be replaced in honor of METADATA_BLOCK_PICTURE structure');
                    /** @todo use 'coverartmime' where available */
                    $imageinfo = getid3_lib::GetDataImageSize($data);
                    if ($imageinfo === false || !isset($imageinfo['mime'])) {
                        $this->warning('COVERART vorbiscomment tag contains invalid image');
                        continue;
                    }

                    $ogg = new self($this->getid3);
                    $ogg->setStringMode($data);
                    $info['ogg']['comments']['picture'][] = array(
                        'image_mime' => $imageinfo['mime'],
                        'data'       => $ogg->saveAttachment('coverart', 0, strlen($data), $imageinfo['mime']),
                    );
                    unset($ogg);

                } else {

                    $info['ogg']['comments'][strtolower($ThisFileInfo_ogg_comments_raw[$i]['key'])][] = $ThisFileInfo_ogg_comments_raw[$i]['value'];

                }

            } else {

                $info['warning'][] = '[known problem with CDex >= v1.40, < v1.50b7] Invalid Ogg comment name/value pair ['.$i.']: '.$commentstring;

            }
            unset($ThisFileInfo_ogg_comments_raw[$i]);
        }
        unset($ThisFileInfo_ogg_comments_raw);


        // Replay Gain Adjustment
        // http://privatewww.essex.ac.uk/~djmrob/replaygain/
        if (isset($info['ogg']['comments']) && is_array($info['ogg']['comments'])) {
            foreach ($info['ogg']['comments'] as $index => $commentvalue) {
                switch ($index) {
                    case 'rg_audiophile':
                    case 'replaygain_album_gain':
                        $info['replay_gain']['album']['adjustment'] = (double) $commentvalue[0];
                        unset($info['ogg']['comments'][$index]);
                        break;

                    case 'rg_radio':
                    case 'replaygain_track_gain':
                        $info['replay_gain']['track']['adjustment'] = (double) $commentvalue[0];
                        unset($info['ogg']['comments'][$index]);
                        break;

                    case 'replaygain_album_peak':
                        $info['replay_gain']['album']['peak'] = (double) $commentvalue[0];
                        unset($info['ogg']['comments'][$index]);
                        break;

                    case 'rg_peak':
                    case 'replaygain_track_peak':
                        $info['replay_gain']['track']['peak'] = (double) $commentvalue[0];
                        unset($info['ogg']['comments'][$index]);
                        break;

                    case 'replaygain_reference_loudness':
                        $info['replay_gain']['reference_volume'] = (double) $commentvalue[0];
                        unset($info['ogg']['comments'][$index]);
                        break;

                    default:
                        // do nothing
                        break;
                }
            }
        }

        $this->fseek($OriginalOffset);

        return true;
    }

    public static function SpeexBandModeLookup($mode) {
        static $SpeexBandModeLookup = array();
        if (empty($SpeexBandModeLookup)) {
            $SpeexBandModeLookup[0] = 'narrow';
            $SpeexBandModeLookup[1] = 'wide';
            $SpeexBandModeLookup[2] = 'ultra-wide';
        }
        return (isset($SpeexBandModeLookup[$mode]) ? $SpeexBandModeLookup[$mode] : null);
    }


    public static function OggPageSegmentLength($OggInfoArray, $SegmentNumber=1) {
        for ($i = 0; $i < $SegmentNumber; $i++) {
            $segmentlength = 0;
            foreach ($OggInfoArray['segment_table'] as $key => $value) {
                $segmentlength += $value;
                if ($value < 255) {
                    break;
                }
            }
        }
        return $segmentlength;
    }


    public static function get_quality_from_nominal_bitrate($nominal_bitrate) {

        // decrease precision
        $nominal_bitrate = $nominal_bitrate / 1000;

        if ($nominal_bitrate < 128) {
            // q-1 to q4
            $qval = ($nominal_bitrate - 64) / 16;
        } elseif ($nominal_bitrate < 256) {
            // q4 to q8
            $qval = $nominal_bitrate / 32;
        } elseif ($nominal_bitrate < 320) {
            // q8 to q9
            $qval = ($nominal_bitrate + 256) / 64;
        } else {
            // q9 to q10
            $qval = ($nominal_bitrate + 1300) / 180;
        }
        //return $qval; // 5.031324
        //return intval($qval); // 5
        return round($qval, 1); // 5 or 4.9
    }

}