/common/libraries/plugin/getid3/module.audio.mp3.php

<?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.mp3.php                                        //
// module for analyzing MP3 files                              //
// dependencies: NONE                                          //
//                                                            ///
/////////////////////////////////////////////////////////////////




// number of frames to scan to determine if MPEG-audio sequence is valid
// Lower this number to 5-20 for faster scanning
// Increase this number to 50+ for most accurate detection of valid VBR/CBR
// mpeg-audio streams
define('GETID3_MP3_VALID_CHECK_FRAMES', 35);



class getid3_mp3

{

    

    var $allow_bruteforce = false; // forces getID3() to scan the file byte-by-byte and log all the valid audio frame headers - extremely slow, unrecommended, but may provide data from otherwise-unusuable files


    

    function __construct(&$fd, &$ThisFileInfo)

    {

        

        if (! $this->getOnlyMPEGaudioInfo($fd, $ThisFileInfo, $ThisFileInfo['avdataoffset']))

        {

            if ($this->allow_bruteforce)

            {

                $ThisFileInfo['error'][] = 'Rescanning file in BruteForce mode';

                $this->getOnlyMPEGaudioInfoBruteForce($fd, $ThisFileInfo);

            }

        }

        

        if (isset($ThisFileInfo['mpeg']['audio']['bitrate_mode']))

        {

            $ThisFileInfo['audio']['bitrate_mode'] = strtolower($ThisFileInfo['mpeg']['audio']['bitrate_mode']);

        }

        

        if (((isset($ThisFileInfo['id3v2']['headerlength']) && ($ThisFileInfo['avdataoffset'] > $ThisFileInfo['id3v2']['headerlength'])) || (! isset($ThisFileInfo['id3v2']) && ($ThisFileInfo['avdataoffset'] > 0))))

        {

            

            $synchoffsetwarning = 'Unknown data before synch ';

            if (isset($ThisFileInfo['id3v2']['headerlength']))

            {

                $synchoffsetwarning .= '(ID3v2 header ends at ' . $ThisFileInfo['id3v2']['headerlength'] . ', then ' . ($ThisFileInfo['avdataoffset'] - $ThisFileInfo['id3v2']['headerlength']) . ' bytes garbage, ';

            }

            else

            {

                $synchoffsetwarning .= '(should be at beginning of file, ';

            }

            $synchoffsetwarning .= 'synch detected at ' . $ThisFileInfo['avdataoffset'] . ')';

            if (@$ThisFileInfo['audio']['bitrate_mode'] == 'cbr')

            {

                

                if (! empty($ThisFileInfo['id3v2']['headerlength']) && (($ThisFileInfo['avdataoffset'] - $ThisFileInfo['id3v2']['headerlength']) == $ThisFileInfo['mpeg']['audio']['framelength']))

                {

                    

                    $synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90-3.92) DLL in CBR mode.';

                    $ThisFileInfo['audio']['codec'] = 'LAME';

                    $CurrentDataLAMEversionString = 'LAME3.';

                

                }

                elseif (empty($ThisFileInfo['id3v2']['headerlength']) && ($ThisFileInfo['avdataoffset'] == $ThisFileInfo['mpeg']['audio']['framelength']))

                {

                    

                    $synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90 - 3.92) DLL in CBR mode.';

                    $ThisFileInfo['audio']['codec'] = 'LAME';

                    $CurrentDataLAMEversionString = 'LAME3.';

                

                }

            

            }

            $ThisFileInfo['warning'][] = $synchoffsetwarning;

        

        }

        

        if (isset($ThisFileInfo['mpeg']['audio']['LAME']))

        {

            $ThisFileInfo['audio']['codec'] = 'LAME';

            if (! empty($ThisFileInfo['mpeg']['audio']['LAME']['long_version']))

            {

                $ThisFileInfo['audio']['encoder'] = rtrim($ThisFileInfo['mpeg']['audio']['LAME']['long_version'], "\x00");

            }

            elseif (! empty($ThisFileInfo['mpeg']['audio']['LAME']['short_version']))

            {

                $ThisFileInfo['audio']['encoder'] = rtrim($ThisFileInfo['mpeg']['audio']['LAME']['short_version'], "\x00");

            }

        }

        

        $CurrentDataLAMEversionString = (! empty($CurrentDataLAMEversionString) ? $CurrentDataLAMEversionString : @$ThisFileInfo['audio']['encoder']);

        if (! empty($CurrentDataLAMEversionString) && (substr($CurrentDataLAMEversionString, 0, 6) == 'LAME3.') && ! preg_match('[0-9\)]', substr($CurrentDataLAMEversionString, - 1)))

        {

            // a version number of LAME that does not end with a number like "LAME3.92"
            // or with a closing parenthesis like "LAME3.88 (alpha)"
            // or a version of LAME with the LAMEtag-not-filled-in-DLL-mode bug (3.90-3.92)
            



            // not sure what the actual last frame length will be, but will be less than or equal to 1441
            $PossiblyLongerLAMEversion_FrameLength = 1441;

            

            // Not sure what version of LAME this is - look in padding of last frame for longer version string
            $PossibleLAMEversionStringOffset = $ThisFileInfo['avdataend'] - $PossiblyLongerLAMEversion_FrameLength;

            fseek($fd, $PossibleLAMEversionStringOffset);

            $PossiblyLongerLAMEversion_Data = fread($fd, $PossiblyLongerLAMEversion_FrameLength);

            switch (substr($CurrentDataLAMEversionString, - 1))

            {

                case 'a' :

                case 'b' :

                    // "LAME3.94a" will have a longer version string of "LAME3.94 (alpha)" for example
                    // need to trim off "a" to match longer string
                    $CurrentDataLAMEversionString = substr($CurrentDataLAMEversionString, 0, - 1);

                    break;

            }

            if (($PossiblyLongerLAMEversion_String = strstr($PossiblyLongerLAMEversion_Data, $CurrentDataLAMEversionString)) !== false)

            {

                if (substr($PossiblyLongerLAMEversion_String, 0, strlen($CurrentDataLAMEversionString)) == $CurrentDataLAMEversionString)

                {

                    $PossiblyLongerLAMEversion_NewString = substr($PossiblyLongerLAMEversion_String, 0, strspn($PossiblyLongerLAMEversion_String, 'LAME0123456789., (abcdefghijklmnopqrstuvwxyzJFSOND)')); //"LAME3.90.3"  "LAME3.87 (beta 1, Sep 27 2000)" "LAME3.88 (beta)"
                    if (strlen($PossiblyLongerLAMEversion_NewString) > strlen(@$ThisFileInfo['audio']['encoder']))

                    {

                        $ThisFileInfo['audio']['encoder'] = $PossiblyLongerLAMEversion_NewString;

                    }

                }

            }

        }

        if (! empty($ThisFileInfo['audio']['encoder']))

        {

            $ThisFileInfo['audio']['encoder'] = rtrim($ThisFileInfo['audio']['encoder'], "\x00 ");

        }

        

        switch (@$ThisFileInfo['mpeg']['audio']['layer'])

        {

            case 1 :

            case 2 :

                $ThisFileInfo['audio']['dataformat'] = 'mp' . $ThisFileInfo['mpeg']['audio']['layer'];

                break;

        }

        if (@$ThisFileInfo['fileformat'] == 'mp3')

        {

            switch ($ThisFileInfo['audio']['dataformat'])

            {

                case 'mp1' :

                case 'mp2' :

                case 'mp3' :

                    $ThisFileInfo['fileformat'] = $ThisFileInfo['audio']['dataformat'];

                    break;

                

                default :

                    $ThisFileInfo['warning'][] = 'Expecting [audio][dataformat] to be mp1/mp2/mp3 when fileformat == mp3, [audio][dataformat] actually "' . $ThisFileInfo['audio']['dataformat'] . '"';

                    break;

            }

        }

        

        if (empty($ThisFileInfo['fileformat']))

        {

            unset($ThisFileInfo['fileformat']);

            unset($ThisFileInfo['audio']['bitrate_mode']);

            unset($ThisFileInfo['avdataoffset']);

            unset($ThisFileInfo['avdataend']);

            return false;

        }

        

        $ThisFileInfo['mime_type'] = 'audio/mpeg';

        $ThisFileInfo['audio']['lossless'] = false;

        

        // Calculate playtime
        if (! isset($ThisFileInfo['playtime_seconds']) && isset($ThisFileInfo['audio']['bitrate']) && ($ThisFileInfo['audio']['bitrate'] > 0))

        {

            $ThisFileInfo['playtime_seconds'] = ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8 / $ThisFileInfo['audio']['bitrate'];

        }

        

        $ThisFileInfo['audio']['encoder_options'] = $this->GuessEncoderOptions($ThisFileInfo);

        

        return true;

    }



    function GuessEncoderOptions(&$ThisFileInfo)

    {

        // shortcuts
        if (! empty($ThisFileInfo['mpeg']['audio']))

        {

            $thisfile_mpeg_audio = &$ThisFileInfo['mpeg']['audio'];

            if (! empty($thisfile_mpeg_audio['LAME']))

            {

                $thisfile_mpeg_audio_lame = &$thisfile_mpeg_audio['LAME'];

            }

        }

        

        $encoder_options = '';

        static $NamedPresetBitrates = array(16, 24, 40, 56, 112, 128, 160, 192, 256);

        

        if ((@$thisfile_mpeg_audio['VBR_method'] == 'Fraunhofer') && ! empty($thisfile_mpeg_audio['VBR_quality']))

        {

            

            $encoder_options = 'VBR q' . $thisfile_mpeg_audio['VBR_quality'];

        

        }

        elseif (! empty($thisfile_mpeg_audio_lame['preset_used']) && (! in_array($thisfile_mpeg_audio_lame['preset_used_id'], $NamedPresetBitrates)))

        {

            

            $encoder_options = $thisfile_mpeg_audio_lame['preset_used'];

        

        }

        elseif (! empty($thisfile_mpeg_audio_lame['vbr_quality']))

        {

            

            static $KnownEncoderValues = array();

            if (empty($KnownEncoderValues))

            {

                

                //$KnownEncoderValues[abrbitrate_minbitrate][vbr_quality][raw_vbr_method][raw_noise_shaping][raw_stereo_mode][ath_type][lowpass_frequency] = 'preset name';
                $KnownEncoderValues[0xFF][58][1][1][3][2][20500] = '--alt-preset insane'; // 3.90,   3.90.1, 3.92
                $KnownEncoderValues[0xFF][58][1][1][3][2][20600] = '--alt-preset insane'; // 3.90.2, 3.90.3, 3.91
                $KnownEncoderValues[0xFF][57][1][1][3][4][20500] = '--alt-preset insane'; // 3.94,   3.95
                $KnownEncoderValues['**'][78][3][2][3][2][19500] = '--alt-preset extreme'; // 3.90,   3.90.1, 3.92
                $KnownEncoderValues['**'][78][3][2][3][2][19600] = '--alt-preset extreme'; // 3.90.2, 3.91
                $KnownEncoderValues['**'][78][3][1][3][2][19600] = '--alt-preset extreme'; // 3.90.3
                $KnownEncoderValues['**'][78][4][2][3][2][19500] = '--alt-preset fast extreme'; // 3.90,   3.90.1, 3.92
                $KnownEncoderValues['**'][78][4][2][3][2][19600] = '--alt-preset fast extreme'; // 3.90.2, 3.90.3, 3.91
                $KnownEncoderValues['**'][78][3][2][3][4][19000] = '--alt-preset standard'; // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
                $KnownEncoderValues['**'][78][3][1][3][4][19000] = '--alt-preset standard'; // 3.90.3
                $KnownEncoderValues['**'][78][4][2][3][4][19000] = '--alt-preset fast standard'; // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
                $KnownEncoderValues['**'][78][4][1][3][4][19000] = '--alt-preset fast standard'; // 3.90.3
                $KnownEncoderValues['**'][88][4][1][3][3][19500] = '--r3mix'; // 3.90,   3.90.1, 3.92
                $KnownEncoderValues['**'][88][4][1][3][3][19600] = '--r3mix'; // 3.90.2, 3.90.3, 3.91
                $KnownEncoderValues['**'][67][4][1][3][4][18000] = '--r3mix'; // 3.94,   3.95
                $KnownEncoderValues['**'][68][3][2][3][4][18000] = '--alt-preset medium'; // 3.90.3
                $KnownEncoderValues['**'][68][4][2][3][4][18000] = '--alt-preset fast medium'; // 3.90.3
                



                $KnownEncoderValues[0xFF][99][1][1][1][2][0] = '--preset studio'; // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
                $KnownEncoderValues[0xFF][58][2][1][3][2][20600] = '--preset studio'; // 3.90.3, 3.93.1
                $KnownEncoderValues[0xFF][58][2][1][3][2][20500] = '--preset studio'; // 3.93
                $KnownEncoderValues[0xFF][57][2][1][3][4][20500] = '--preset studio'; // 3.94,   3.95
                $KnownEncoderValues[0xC0][88][1][1][1][2][0] = '--preset cd'; // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
                $KnownEncoderValues[0xC0][58][2][2][3][2][19600] = '--preset cd'; // 3.90.3, 3.93.1
                $KnownEncoderValues[0xC0][58][2][2][3][2][19500] = '--preset cd'; // 3.93
                $KnownEncoderValues[0xC0][57][2][1][3][4][19500] = '--preset cd'; // 3.94,   3.95
                $KnownEncoderValues[0xA0][78][1][1][3][2][18000] = '--preset hifi'; // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
                $KnownEncoderValues[0xA0][58][2][2][3][2][18000] = '--preset hifi'; // 3.90.3, 3.93,   3.93.1
                $KnownEncoderValues[0xA0][57][2][1][3][4][18000] = '--preset hifi'; // 3.94,   3.95
                $KnownEncoderValues[0x80][67][1][1][3][2][18000] = '--preset tape'; // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
                $KnownEncoderValues[0x80][67][1][1][3][2][15000] = '--preset radio'; // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
                $KnownEncoderValues[0x70][67][1][1][3][2][15000] = '--preset fm'; // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
                $KnownEncoderValues[0x70][58][2][2][3][2][16000] = '--preset tape/radio/fm'; // 3.90.3, 3.93,   3.93.1
                $KnownEncoderValues[0x70][57][2][1][3][4][16000] = '--preset tape/radio/fm'; // 3.94,   3.95
                $KnownEncoderValues[0x38][58][2][2][0][2][10000] = '--preset voice'; // 3.90.3, 3.93,   3.93.1
                $KnownEncoderValues[0x38][57][2][1][0][4][15000] = '--preset voice'; // 3.94,   3.95
                $KnownEncoderValues[0x38][57][2][1][0][4][16000] = '--preset voice'; // 3.94a14
                $KnownEncoderValues[0x28][65][1][1][0][2][7500] = '--preset mw-us'; // 3.90,   3.90.1, 3.92
                $KnownEncoderValues[0x28][65][1][1][0][2][7600] = '--preset mw-us'; // 3.90.2, 3.91
                $KnownEncoderValues[0x28][58][2][2][0][2][7000] = '--preset mw-us'; // 3.90.3, 3.93,   3.93.1
                $KnownEncoderValues[0x28][57][2][1][0][4][10500] = '--preset mw-us'; // 3.94,   3.95
                $KnownEncoderValues[0x28][57][2][1][0][4][11200] = '--preset mw-us'; // 3.94a14
                $KnownEncoderValues[0x28][57][2][1][0][4][8800] = '--preset mw-us'; // 3.94a15
                $KnownEncoderValues[0x18][58][2][2][0][2][4000] = '--preset phon+/lw/mw-eu/sw'; // 3.90.3, 3.93.1
                $KnownEncoderValues[0x18][58][2][2][0][2][3900] = '--preset phon+/lw/mw-eu/sw'; // 3.93
                $KnownEncoderValues[0x18][57][2][1][0][4][5900] = '--preset phon+/lw/mw-eu/sw'; // 3.94,   3.95
                $KnownEncoderValues[0x18][57][2][1][0][4][6200] = '--preset phon+/lw/mw-eu/sw'; // 3.94a14
                $KnownEncoderValues[0x18][57][2][1][0][4][3200] = '--preset phon+/lw/mw-eu/sw'; // 3.94a15
                $KnownEncoderValues[0x10][58][2][2][0][2][3800] = '--preset phone'; // 3.90.3, 3.93.1
                $KnownEncoderValues[0x10][58][2][2][0][2][3700] = '--preset phone'; // 3.93
                $KnownEncoderValues[0x10][57][2][1][0][4][5600] = '--preset phone'; // 3.94,   3.95
            }

            

            if (isset($KnownEncoderValues[$thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate']][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']]))

            {

                

                $encoder_options = $KnownEncoderValues[$thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate']][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']];

            

            }

            elseif (isset($KnownEncoderValues['**'][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']]))

            {

                

                $encoder_options = $KnownEncoderValues['**'][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']];

            

            }

            elseif ($ThisFileInfo['audio']['bitrate_mode'] == 'vbr')

            {

                

                // http://gabriel.mp3-tech.org/mp3infotag.html
                // int    Quality = (100 - 10 * gfp->VBR_q - gfp->quality)h
                



                $LAME_V_value = 10 - ceil($thisfile_mpeg_audio_lame['vbr_quality'] / 10);

                $LAME_q_value = 100 - $thisfile_mpeg_audio_lame['vbr_quality'] - ($LAME_V_value * 10);

                $encoder_options = '-V' . $LAME_V_value . ' -q' . $LAME_q_value;

            

            }

            elseif ($ThisFileInfo['audio']['bitrate_mode'] == 'cbr')

            {

                

                $encoder_options = strtoupper($ThisFileInfo['audio']['bitrate_mode']) . ceil($ThisFileInfo['audio']['bitrate'] / 1000);

            

            }

            else

            {

                

                $encoder_options = strtoupper($ThisFileInfo['audio']['bitrate_mode']);

            

            }

        

        }

        elseif (! empty($thisfile_mpeg_audio_lame['bitrate_abr']))

        {

            

            $encoder_options = 'ABR' . $thisfile_mpeg_audio_lame['bitrate_abr'];

        

        }

        elseif (! empty($ThisFileInfo['audio']['bitrate']))

        {

            

            if ($ThisFileInfo['audio']['bitrate_mode'] == 'cbr')

            {

                $encoder_options = strtoupper($ThisFileInfo['audio']['bitrate_mode']) . ceil($ThisFileInfo['audio']['bitrate'] / 1000);

            }

            else

            {

                $encoder_options = strtoupper($ThisFileInfo['audio']['bitrate_mode']);

            }

        

        }

        if (! empty($thisfile_mpeg_audio_lame['bitrate_min']))

        {

            $encoder_options .= ' -b' . $thisfile_mpeg_audio_lame['bitrate_min'];

        }

        

        if (@$thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev'] || @$thisfile_mpeg_audio_lame['encoding_flags']['nogap_next'])

        {

            $encoder_options .= ' --nogap';

        }

        

        if (! empty($thisfile_mpeg_audio_lame['lowpass_frequency']))

        {

            $ExplodedOptions = explode(' ', $encoder_options, 4);

            if ($ExplodedOptions[0] == '--r3mix')

            {

                $ExplodedOptions[1] = 'r3mix';

            }

            switch ($ExplodedOptions[0])

            {

                case '--preset' :

                case '--alt-preset' :

                case '--r3mix' :

                    if ($ExplodedOptions[1] == 'fast')

                    {

                        $ExplodedOptions[1] .= ' ' . $ExplodedOptions[2];

                    }

                    switch ($ExplodedOptions[1])

                    {

                        case 'portable' :

                        case 'medium' :

                        case 'standard' :

                        case 'extreme' :

                        case 'insane' :

                        case 'fast portable' :

                        case 'fast medium' :

                        case 'fast standard' :

                        case 'fast extreme' :

                        case 'fast insane' :

                        case 'r3mix' :

                            static $ExpectedLowpass = array('insane|20500' => 20500, 'insane|20600' => 20600,  // 3.90.2, 3.90.3, 3.91
                                    'medium|18000' => 18000, 

                                    'fast medium|18000' => 18000, 'extreme|19500' => 19500,  // 3.90,   3.90.1, 3.92, 3.95
                                    'extreme|19600' => 19600,  // 3.90.2, 3.90.3, 3.91, 3.93.1
                                    'fast extreme|19500' => 19500,  // 3.90,   3.90.1, 3.92, 3.95
                                    'fast extreme|19600' => 19600,  // 3.90.2, 3.90.3, 3.91, 3.93.1
                                    'standard|19000' => 19000, 

                                    'fast standard|19000' => 19000, 'r3mix|19500' => 19500,  // 3.90,   3.90.1, 3.92
                                    'r3mix|19600' => 19600,  // 3.90.2, 3.90.3, 3.91
                                    'r3mix|18000' => 18000)// 3.94,   3.95
;

                            if (! isset($ExpectedLowpass[$ExplodedOptions[1] . '|' . $thisfile_mpeg_audio_lame['lowpass_frequency']]) && ($thisfile_mpeg_audio_lame['lowpass_frequency'] < 22050) && (round($thisfile_mpeg_audio_lame['lowpass_frequency'] / 1000) < round($thisfile_mpeg_audio['sample_rate'] / 2000)))

                            {

                                $encoder_options .= ' --lowpass ' . $thisfile_mpeg_audio_lame['lowpass_frequency'];

                            }

                            break;

                        

                        default :

                            break;

                    }

                    break;

            }

        }

        

        if (isset($thisfile_mpeg_audio_lame['raw']['source_sample_freq']))

        {

            if (($thisfile_mpeg_audio['sample_rate'] == 44100) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 1))

            {

                $encoder_options .= ' --resample 44100';

            }

            elseif (($thisfile_mpeg_audio['sample_rate'] == 48000) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 2))

            {

                $encoder_options .= ' --resample 48000';

            }

            elseif ($thisfile_mpeg_audio['sample_rate'] < 44100)

            {

                switch ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'])

                {

                    case 0 : // <= 32000
                        // may or may not be same as source frequency - ignore
                        break;

                    case 1 : // 44100
                    case 2 : // 48000
                    case 3 : // 48000+
                        $ExplodedOptions = explode(' ', $encoder_options, 4);

                        switch ($ExplodedOptions[0])

                        {

                            case '--preset' :

                            case '--alt-preset' :

                                switch ($ExplodedOptions[1])

                                {

                                    case 'fast' :

                                    case 'portable' :

                                    case 'medium' :

                                    case 'standard' :

                                    case 'extreme' :

                                    case 'insane' :

                                        $encoder_options .= ' --resample ' . $thisfile_mpeg_audio['sample_rate'];

                                        break;

                                    

                                    default :

                                        static $ExpectedResampledRate = array('phon+/lw/mw-eu/sw|16000' => 16000, 

                                                'mw-us|24000' => 24000, // 3.95
'mw-us|32000' => 32000,  // 3.93
                                                'mw-us|16000' => 16000,  // 3.92
                                                'phone|16000' => 16000, 

                                                'phone|11025' => 11025, // 3.94a15
'radio|32000' => 32000,  // 3.94a15
                                                'fm/radio|32000' => 32000,  // 3.92
                                                'fm|32000' => 32000,  // 3.90
                                                'voice|32000' => 32000);

                                        if (! isset($ExpectedResampledRate[$ExplodedOptions[1] . '|' . $thisfile_mpeg_audio['sample_rate']]))

                                        {

                                            $encoder_options .= ' --resample ' . $thisfile_mpeg_audio['sample_rate'];

                                        }

                                        break;

                                }

                                break;

                            

                            case '--r3mix' :

                            default :

                                $encoder_options .= ' --resample ' . $thisfile_mpeg_audio['sample_rate'];

                                break;

                        }

                        break;

                }

            }

        }

        if (empty($encoder_options) && ! empty($ThisFileInfo['audio']['bitrate']) && ! empty($ThisFileInfo['audio']['bitrate_mode']))

        {

            //$encoder_options = strtoupper($ThisFileInfo['audio']['bitrate_mode']).ceil($ThisFileInfo['audio']['bitrate'] / 1000);
            $encoder_options = strtoupper($ThisFileInfo['audio']['bitrate_mode']);

        }

        

        return $encoder_options;

    }



    function decodeMPEGaudioHeader($fd, $offset, &$ThisFileInfo, $recursivesearch = true, $ScanAsCBR = false, $FastMPEGheaderScan = false)

    {

        

        static $MPEGaudioVersionLookup;

        static $MPEGaudioLayerLookup;

        static $MPEGaudioBitrateLookup;

        static $MPEGaudioFrequencyLookup;

        static $MPEGaudioChannelModeLookup;

        static $MPEGaudioModeExtensionLookup;

        static $MPEGaudioEmphasisLookup;

        if (empty($MPEGaudioVersionLookup))

        {

            $MPEGaudioVersionLookup = getid3_mp3 :: MPEGaudioVersionArray();

            $MPEGaudioLayerLookup = getid3_mp3 :: MPEGaudioLayerArray();

            $MPEGaudioBitrateLookup = getid3_mp3 :: MPEGaudioBitrateArray();

            $MPEGaudioFrequencyLookup = getid3_mp3 :: MPEGaudioFrequencyArray();

            $MPEGaudioChannelModeLookup = getid3_mp3 :: MPEGaudioChannelModeArray();

            $MPEGaudioModeExtensionLookup = getid3_mp3 :: MPEGaudioModeExtensionArray();

            $MPEGaudioEmphasisLookup = getid3_mp3 :: MPEGaudioEmphasisArray();

        }

        

        if ($offset >= $ThisFileInfo['avdataend'])

        {

            $ThisFileInfo['error'][] = 'end of file encounter looking for MPEG synch';

            return false;

        }

        fseek($fd, $offset, SEEK_SET);

        //$headerstring = fread($fd, 1441); // worst-case max length = 32kHz @ 320kbps layer 3 = 1441 bytes/frame
        $headerstring = fread($fd, 226); // LAME header at offset 36 + 190 bytes of Xing/LAME data
        



        // MP3 audio frame structure:
        // $aa $aa $aa $aa [$bb $bb] $cc...
        // where $aa..$aa is the four-byte mpeg-audio header (below)
        // $bb $bb is the optional 2-byte CRC
        // and $cc... is the audio data
        



        $head4 = substr($headerstring, 0, 4);

        

        static $MPEGaudioHeaderDecodeCache = array();

        if (isset($MPEGaudioHeaderDecodeCache[$head4]))

        {

            $MPEGheaderRawArray = $MPEGaudioHeaderDecodeCache[$head4];

        }

        else

        {

            $MPEGheaderRawArray = getid3_mp3 :: MPEGaudioHeaderDecode($head4);

            $MPEGaudioHeaderDecodeCache[$head4] = $MPEGheaderRawArray;

        }

        

        static $MPEGaudioHeaderValidCache = array();

        

        // Not in cache
        if (! isset($MPEGaudioHeaderValidCache[$head4]))

        {

            //$MPEGaudioHeaderValidCache[$head4] = getid3_mp3::MPEGaudioHeaderValid($MPEGheaderRawArray, false, true);  // allow badly-formatted freeformat (from LAME 3.90 - 3.93.1)
            $MPEGaudioHeaderValidCache[$head4] = getid3_mp3 :: MPEGaudioHeaderValid($MPEGheaderRawArray, false, false);

        }

        

        // shortcut
        if (! isset($ThisFileInfo['mpeg']['audio']))

        {

            $ThisFileInfo['mpeg']['audio'] = array();

        }

        $thisfile_mpeg_audio = &$ThisFileInfo['mpeg']['audio'];

        

        if ($MPEGaudioHeaderValidCache[$head4])

        {

            $thisfile_mpeg_audio['raw'] = $MPEGheaderRawArray;

        }

        else

        {

            $ThisFileInfo['error'][] = 'Invalid MPEG audio header at offset ' . $offset;

            return false;

        }

        

        if (! $FastMPEGheaderScan)

        {

            

            $thisfile_mpeg_audio['version'] = $MPEGaudioVersionLookup[$thisfile_mpeg_audio['raw']['version']];

            $thisfile_mpeg_audio['layer'] = $MPEGaudioLayerLookup[$thisfile_mpeg_audio['raw']['layer']];

            

            $thisfile_mpeg_audio['channelmode'] = $MPEGaudioChannelModeLookup[$thisfile_mpeg_audio['raw']['channelmode']];

            $thisfile_mpeg_audio['channels'] = (($thisfile_mpeg_audio['channelmode'] == 'mono') ? 1 : 2);

            $thisfile_mpeg_audio['sample_rate'] = $MPEGaudioFrequencyLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['raw']['sample_rate']];

            $thisfile_mpeg_audio['protection'] = ! $thisfile_mpeg_audio['raw']['protection'];

            $thisfile_mpeg_audio['private'] = (bool) $thisfile_mpeg_audio['raw']['private'];

            $thisfile_mpeg_audio['modeextension'] = $MPEGaudioModeExtensionLookup[$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['modeextension']];

            $thisfile_mpeg_audio['copyright'] = (bool) $thisfile_mpeg_audio['raw']['copyright'];

            $thisfile_mpeg_audio['original'] = (bool) $thisfile_mpeg_audio['raw']['original'];

            $thisfile_mpeg_audio['emphasis'] = $MPEGaudioEmphasisLookup[$thisfile_mpeg_audio['raw']['emphasis']];

            

            $ThisFileInfo['audio']['channels'] = $thisfile_mpeg_audio['channels'];

            $ThisFileInfo['audio']['sample_rate'] = $thisfile_mpeg_audio['sample_rate'];

            

            if ($thisfile_mpeg_audio['protection'])

            {

                $thisfile_mpeg_audio['crc'] = getid3_lib :: BigEndian2Int(substr($headerstring, 4, 2));

            }

        

        }

        

        if ($thisfile_mpeg_audio['raw']['bitrate'] == 15)

        {

            // http://www.hydrogenaudio.org/?act=ST&f=16&t=9682&st=0
            $ThisFileInfo['warning'][] = 'Invalid bitrate index (15), this is a known bug in free-format MP3s encoded by LAME v3.90 - 3.93.1';

            $thisfile_mpeg_audio['raw']['bitrate'] = 0;

        }

        $thisfile_mpeg_audio['padding'] = (bool) $thisfile_mpeg_audio['raw']['padding'];

        $thisfile_mpeg_audio['bitrate'] = $MPEGaudioBitrateLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['bitrate']];

        

        if (($thisfile_mpeg_audio['bitrate'] == 'free') && ($offset == $ThisFileInfo['avdataoffset']))

        {

            // only skip multiple frame check if free-format bitstream found at beginning of file
            // otherwise is quite possibly simply corrupted data
            $recursivesearch = false;

        }

        

        // For Layer 2 there are some combinations of bitrate and mode which are not allowed.
        if (! $FastMPEGheaderScan && ($thisfile_mpeg_audio['layer'] == '2'))

        {

            

            $ThisFileInfo['audio']['dataformat'] = 'mp2';

            switch ($thisfile_mpeg_audio['channelmode'])

            {

                

                case 'mono' :

                    if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] <= 192000))

                    {

                        // these are ok
                    }

                    else

                    {

                        $ThisFileInfo['error'][] = $thisfile_mpeg_audio['bitrate'] . 'kbps not allowed in Layer 2, ' . $thisfile_mpeg_audio['channelmode'] . '.';

                        return false;

                    }

                    break;

                

                case 'stereo' :

                case 'joint stereo' :

                case 'dual channel' :

                    if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] == 64000) || ($thisfile_mpeg_audio['bitrate'] >= 96000))

                    {

                        // these are ok
                    }

                    else

                    {

                        $ThisFileInfo['error'][] = intval(round($thisfile_mpeg_audio['bitrate'] / 1000)) . 'kbps not allowed in Layer 2, ' . $thisfile_mpeg_audio['channelmode'] . '.';

                        return false;

                    }

                    break;

            

            }

        

        }

        

        if ($ThisFileInfo['audio']['sample_rate'] > 0)

        {

            $thisfile_mpeg_audio['framelength'] = getid3_mp3 :: MPEGaudioFrameLength($thisfile_mpeg_audio['bitrate'], $thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['layer'], (int) $thisfile_mpeg_audio['padding'], $ThisFileInfo['audio']['sample_rate']);

        }

        

        $nextframetestoffset = $offset + 1;

        if ($thisfile_mpeg_audio['bitrate'] != 'free')

        {

            

            $ThisFileInfo['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];

            

            if (isset($thisfile_mpeg_audio['framelength']))

            {

                $nextframetestoffset = $offset + $thisfile_mpeg_audio['framelength'];

            }

            else

            {

                $ThisFileInfo['error'][] = 'Frame at offset(' . $offset . ') is has an invalid frame length.';

                return false;

            }

        

        }

        

        $ExpectedNumberOfAudioBytes = 0;

        

        ////////////////////////////////////////////////////////////////////////////////////
        // Variable-bitrate headers
        



        if (substr($headerstring, 4 + 32, 4) == 'VBRI')

        {

            // Fraunhofer VBR header is hardcoded 'VBRI' at offset 0x24 (36)
            // specs taken from http://minnie.tuhs.org/pipermail/mp3encoder/2001-January/001800.html
            



            $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';

            $thisfile_mpeg_audio['VBR_method'] = 'Fraunhofer';

            $ThisFileInfo['audio']['codec'] = 'Fraunhofer';

            

            $SideInfoData = substr($headerstring, 4 + 2, 32);

            

            $FraunhoferVBROffset = 36;

            

            $thisfile_mpeg_audio['VBR_encoder_version'] = getid3_lib :: BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 4, 2)); // VbriVersion
            $thisfile_mpeg_audio['VBR_encoder_delay'] = getid3_lib :: BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 6, 2)); // VbriDelay
            $thisfile_mpeg_audio['VBR_quality'] = getid3_lib :: BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 8, 2)); // VbriQuality
            $thisfile_mpeg_audio['VBR_bytes'] = getid3_lib :: BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 10, 4)); // VbriStreamBytes
            $thisfile_mpeg_audio['VBR_frames'] = getid3_lib :: BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 14, 4)); // VbriStreamFrames
            $thisfile_mpeg_audio['VBR_seek_offsets'] = getid3_lib :: BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 18, 2)); // VbriTableSize
            $thisfile_mpeg_audio['VBR_seek_scale'] = getid3_lib :: BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 20, 2)); // VbriTableScale
            $thisfile_mpeg_audio['VBR_entry_bytes'] = getid3_lib :: BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 22, 2)); // VbriEntryBytes
            $thisfile_mpeg_audio['VBR_entry_frames'] = getid3_lib :: BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 24, 2)); // VbriEntryFrames
            



            $ExpectedNumberOfAudioBytes = $thisfile_mpeg_audio['VBR_bytes'];

            

            $previousbyteoffset = $offset;

            for($i = 0; $i < $thisfile_mpeg_audio['VBR_seek_offsets']; $i ++)

            {

                $Fraunhofer_OffsetN = getid3_lib :: BigEndian2Int(substr($headerstring, $FraunhoferVBROffset, $thisfile_mpeg_audio['VBR_entry_bytes']));

                $FraunhoferVBROffset += $thisfile_mpeg_audio['VBR_entry_bytes'];

                $thisfile_mpeg_audio['VBR_offsets_relative'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']);

                $thisfile_mpeg_audio['VBR_offsets_absolute'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']) + $previousbyteoffset;

                $previousbyteoffset += $Fraunhofer_OffsetN;

            }

        

        }

        else

        {

            

            // Xing VBR header is hardcoded 'Xing' at a offset 0x0D (13), 0x15 (21) or 0x24 (36)
            // depending on MPEG layer and number of channels
            



            $VBRidOffset = getid3_mp3 :: XingVBRidOffset($thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['channelmode']);

            $SideInfoData = substr($headerstring, 4 + 2, $VBRidOffset - 4);

            

            if ((substr($headerstring, $VBRidOffset, strlen('Xing')) == 'Xing') || (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Info'))

            {

                // 'Xing' is traditional Xing VBR frame
                // 'Info' is LAME-encoded CBR (This was done to avoid CBR files to be recognized as traditional Xing VBR files by some decoders.)
                // 'Info' *can* legally be used to specify a VBR file as well, however.
                



                // http://www.multiweb.cz/twoinches/MP3inside.htm
                //00..03 = "Xing" or "Info"
                //04..07 = Flags:
                //  0x01  Frames Flag     set if value for number of frames in file is stored
                //  0x02  Bytes Flag      set if value for filesize in bytes is stored
                //  0x04  TOC Flag        set if values for TOC are stored
                //  0x08  VBR Scale Flag  set if values for VBR scale is stored
                //08..11  Frames: Number of frames in file (including the first Xing/Info one)
                //12..15  Bytes:  File length in Bytes
                //16..115  TOC (Table of Contents):
                //  Contains of 100 indexes (one Byte length) for easier lookup in file. Approximately solves problem with moving inside file.
                //  Each Byte has a value according this formula:
                //  (TOC[i] / 256) * fileLenInBytes
                //  So if song lasts eg. 240 sec. and you want to jump to 60. sec. (and file is 5 000 000 Bytes length) you can use:
                //  TOC[(60/240)*100] = TOC[25]
                //  and corresponding Byte in file is then approximately at:
                //  (TOC[25]/256) * 5000000
                //116..119  VBR Scale
                



                // should be safe to leave this at 'vbr' and let it be overriden to 'cbr' if a CBR preset/mode is used by LAME
                //				if (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Xing') {
                $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';

                $thisfile_mpeg_audio['VBR_method'] = 'Xing';

                //				} else {
                //					$ScanAsCBR = true;
                //					$thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
                //				}
                



                $thisfile_mpeg_audio['xing_flags_raw'] = getid3_lib :: BigEndian2Int(substr($headerstring, $VBRidOffset + 4, 4));

                

                $thisfile_mpeg_audio['xing_flags']['frames'] = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000001);

                $thisfile_mpeg_audio['xing_flags']['bytes'] = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000002);

                $thisfile_mpeg_audio['xing_flags']['toc'] = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000004);

                $thisfile_mpeg_audio['xing_flags']['vbr_scale'] = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000008);

                

                if ($thisfile_mpeg_audio['xing_flags']['frames'])

                {

                    $thisfile_mpeg_audio['VBR_frames'] = getid3_lib :: BigEndian2Int(substr($headerstring, $VBRidOffset + 8, 4));

                

     //$thisfile_mpeg_audio['VBR_frames']--; // don't count header Xing/Info frame
                }

                if ($thisfile_mpeg_audio['xing_flags']['bytes'])

                {

                    $thisfile_mpeg_audio['VBR_bytes'] = getid3_lib :: BigEndian2Int(substr($headerstring, $VBRidOffset + 12, 4));

                }

                

                //if (($thisfile_mpeg_audio['bitrate'] == 'free') && !empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {
                if (! empty($thisfile_mpeg_audio['VBR_frames']) && ! empty($thisfile_mpeg_audio['VBR_bytes']))

                {

                    

                    $framelengthfloat = $thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames'];

                    

                    if ($thisfile_mpeg_audio['layer'] == '1')

                    {

                        // BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
                        //$ThisFileInfo['audio']['bitrate'] = ((($framelengthfloat / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
                        $ThisFileInfo['audio']['bitrate'] = ($framelengthfloat / 4) * $thisfile_mpeg_audio['sample_rate'] * (2 / $ThisFileInfo['audio']['channels']) / 12;

                    }

                    else

                    {

                        // Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
                        //$ThisFileInfo['audio']['bitrate'] = (($framelengthfloat - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
                        $ThisFileInfo['audio']['bitrate'] = $framelengthfloat * $thisfile_mpeg_audio['sample_rate'] * (2 / $ThisFileInfo['audio']['channels']) / 144;

                    }

                    $thisfile_mpeg_audio['framelength'] = floor($framelengthfloat);

                }

                

                if ($thisfile_mpeg_audio['xing_flags']['toc'])

                {

                    $LAMEtocData = substr($headerstring, $VBRidOffset + 16, 100);

                    for($i = 0; $i < 100; $i ++)

                    {

                        $thisfile_mpeg_audio['toc'][$i] = ord($LAMEtocData{$i});

                    }

                }

                if ($thisfile_mpeg_audio['xing_flags']['vbr_scale'])

                {

                    $thisfile_mpeg_audio['VBR_scale'] = getid3_lib :: BigEndian2Int(substr($headerstring, $VBRidOffset + 116, 4));

                }

                

                // http://gabriel.mp3-tech.org/mp3infotag.html
                if (substr($headerstring, $VBRidOffset + 120, 4) == 'LAME')

                {

                    

                    // shortcut
                    $thisfile_mpeg_audio['LAME'] = array();

                    $thisfile_mpeg_audio_lame = &$thisfile_mpeg_audio['LAME'];

                    

                    $thisfile_mpeg_audio_lame['long_version'] = substr($headerstring, $VBRidOffset + 120, 20);

                    $thisfile_mpeg_audio_lame['short_version'] = substr($thisfile_mpeg_audio_lame['long_version'], 0, 9);

                    

                    if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.90')

                    {

                        

                        // extra 11 chars are not part of version string when LAMEtag present
                        unset($thisfile_mpeg_audio_lame['long_version']);

                        

                        // It the LAME tag was only introduced in LAME v3.90
                        // http://www.hydrogenaudio.org/?act=ST&f=15&t=9933
                        



                        // Offsets of various bytes in http://gabriel.mp3-tech.org/mp3infotag.html
                        // are assuming a 'Xing' identifier offset of 0x24, which is the case for
                        // MPEG-1 non-mono, but not for other combinations
                        $LAMEtagOffsetContant = $VBRidOffset - 0x24;

                        

                        // shortcuts
                        $thisfile_mpeg_audio_lame['RGAD'] = array('track' => array(), 

                                'album' => array());

                        $thisfile_mpeg_audio_lame_RGAD = &$thisfile_mpeg_audio_lame['RGAD'];

                        $thisfile_mpeg_audio_lame_RGAD_track = &$thisfile_mpeg_audio_lame_RGAD['track'];

                        $thisfile_mpeg_audio_lame_RGAD_album = &$thisfile_mpeg_audio_lame_RGAD['album'];

                        $thisfile_mpeg_audio_lame['raw'] = array();

                        $thisfile_mpeg_audio_lame_raw = &$thisfile_mpeg_audio_lame['raw'];

                        

                        // byte $9B  VBR Quality
                        // This field is there to indicate a quality level, although the scale was not precised in the original Xing specifications.
                        // Actually overwrites original Xing bytes
                        unset($thisfile_mpeg_audio['VBR_scale']);

                        $thisfile_mpeg_audio_lame['vbr_quality'] = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0x9B, 1));

                        

                        // bytes $9C-$A4  Encoder short VersionString
                        $thisfile_mpeg_audio_lame['short_version'] = substr($headerstring, $LAMEtagOffsetContant + 0x9C, 9);

                        

                        // byte $A5  Info Tag revision + VBR method
                        $LAMEtagRevisionVBRmethod = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA5, 1));

                        

                        $thisfile_mpeg_audio_lame['tag_revision'] = ($LAMEtagRevisionVBRmethod & 0xF0) >> 4;

                        $thisfile_mpeg_audio_lame_raw['vbr_method'] = $LAMEtagRevisionVBRmethod & 0x0F;

                        $thisfile_mpeg_audio_lame['vbr_method'] = getid3_mp3 :: LAMEvbrMethodLookup($thisfile_mpeg_audio_lame_raw['vbr_method']);

                        $thisfile_mpeg_audio['bitrate_mode'] = substr($thisfile_mpeg_audio_lame['vbr_method'], 0, 3); // usually either 'cbr' or 'vbr', but truncates 'vbr-old / vbr-rh' to 'vbr'
                        



                        // byte $A6  Lowpass filter value
                        $thisfile_mpeg_audio_lame['lowpass_frequency'] = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA6, 1)) * 100;

                        

                        // bytes $A7-$AE  Replay Gain
                        // http://privatewww.essex.ac.uk/~djmrob/replaygain/rg_data_format.html
                        // bytes $A7-$AA : 32 bit floating point "Peak signal amplitude"
                        if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.94b')

                        {

                            // LAME 3.94a16 and later - 9.23 fixed point
                            // ie 0x0059E2EE / (2^23) = 5890798 / 8388608 = 0.7022378444671630859375
                            $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = (float) ((getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4))) / 8388608);

                        }

                        else

                        {

                            // LAME 3.94a15 and earlier - 32-bit floating point
                            // Actually 3.94a16 will fall in here too and be WRONG, but is hard to detect 3.94a16 vs 3.94a15
                            $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = getid3_lib :: LittleEndian2Float(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4));

                        }

                        if ($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] == 0)

                        {

                            unset($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);

                        }

                        else

                        {

                            $thisfile_mpeg_audio_lame_RGAD['peak_db'] = getid3_lib :: RGADamplitude2dB($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);

                        }

                        

                        $thisfile_mpeg_audio_lame_raw['RGAD_track'] = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAB, 2));

                        $thisfile_mpeg_audio_lame_raw['RGAD_album'] = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAD, 2));

                        

                        if ($thisfile_mpeg_audio_lame_raw['RGAD_track'] != 0)

                        {

                            

                            $thisfile_mpeg_audio_lame_RGAD_track['raw']['name'] = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0xE000) >> 13;

                            $thisfile_mpeg_audio_lame_RGAD_track['raw']['originator'] = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x1C00) >> 10;

                            $thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit'] = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x0200) >> 9;

                            $thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'] = $thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x01FF;

                            $thisfile_mpeg_audio_lame_RGAD_track['name'] = getid3_lib :: RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['name']);

                            $thisfile_mpeg_audio_lame_RGAD_track['originator'] = getid3_lib :: RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['originator']);

                            $thisfile_mpeg_audio_lame_RGAD_track['gain_db'] = getid3_lib :: RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit']);

                            

                            if (! empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']))

                            {

                                $ThisFileInfo['replay_gain']['track']['peak'] = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];

                            }

                            $ThisFileInfo['replay_gain']['track']['originator'] = $thisfile_mpeg_audio_lame_RGAD_track['originator'];

                            $ThisFileInfo['replay_gain']['track']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_track['gain_db'];

                        }

                        else

                        {

                            unset($thisfile_mpeg_audio_lame_RGAD['track']);

                        }

                        if ($thisfile_mpeg_audio_lame_raw['RGAD_album'] != 0)

                        {

                            

                            $thisfile_mpeg_audio_lame_RGAD_album['raw']['name'] = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0xE000) >> 13;

                            $thisfile_mpeg_audio_lame_RGAD_album['raw']['originator'] = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x1C00) >> 10;

                            $thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit'] = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x0200) >> 9;

                            $thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'] = $thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x01FF;

                            $thisfile_mpeg_audio_lame_RGAD_album['name'] = getid3_lib :: RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['name']);

                            $thisfile_mpeg_audio_lame_RGAD_album['originator'] = getid3_lib :: RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['originator']);

                            $thisfile_mpeg_audio_lame_RGAD_album['gain_db'] = getid3_lib :: RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit']);

                            

                            if (! empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']))

                            {

                                $ThisFileInfo['replay_gain']['album']['peak'] = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];

                            }

                            $ThisFileInfo['replay_gain']['album']['originator'] = $thisfile_mpeg_audio_lame_RGAD_album['originator'];

                            $ThisFileInfo['replay_gain']['album']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_album['gain_db'];

                        }

                        else

                        {

                            unset($thisfile_mpeg_audio_lame_RGAD['album']);

                        }

                        if (empty($thisfile_mpeg_audio_lame_RGAD))

                        {

                            unset($thisfile_mpeg_audio_lame['RGAD']);

                        }

                        

                        // byte $AF  Encoding flags + ATH Type
                        $EncodingFlagsATHtype = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAF, 1));

                        $thisfile_mpeg_audio_lame['encoding_flags']['nspsytune'] = (bool) ($EncodingFlagsATHtype & 0x10);

                        $thisfile_mpeg_audio_lame['encoding_flags']['nssafejoint'] = (bool) ($EncodingFlagsATHtype & 0x20);

                        $thisfile_mpeg_audio_lame['encoding_flags']['nogap_next'] = (bool) ($EncodingFlagsATHtype & 0x40);

                        $thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev'] = (bool) ($EncodingFlagsATHtype & 0x80);

                        $thisfile_mpeg_audio_lame['ath_type'] = $EncodingFlagsATHtype & 0x0F;

                        

                        // byte $B0  if ABR {specified bitrate} else {minimal bitrate}
                        $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB0, 1));

                        if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 2)

                        { // Average BitRate (ABR)
                            $thisfile_mpeg_audio_lame['bitrate_abr'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];

                        }

                        elseif ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1)

                        { // Constant BitRate (CBR)
                        // ignore
                        }

                        elseif ($thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] > 0)

                        { // Variable BitRate (VBR) - minimum bitrate
                            $thisfile_mpeg_audio_lame['bitrate_min'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];

                        }

                        

                        // bytes $B1-$B3  Encoder delays
                        $EncoderDelays = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB1, 3));

                        $thisfile_mpeg_audio_lame['encoder_delay'] = ($EncoderDelays & 0xFFF000) >> 12;

                        $thisfile_mpeg_audio_lame['end_padding'] = $EncoderDelays & 0x000FFF;

                        

                        // byte $B4  Misc
                        $MiscByte = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB4, 1));

                        $thisfile_mpeg_audio_lame_raw['noise_shaping'] = ($MiscByte & 0x03);

                        $thisfile_mpeg_audio_lame_raw['stereo_mode'] = ($MiscByte & 0x1C) >> 2;

                        $thisfile_mpeg_audio_lame_raw['not_optimal_quality'] = ($MiscByte & 0x20) >> 5;

                        $thisfile_mpeg_audio_lame_raw['source_sample_freq'] = ($MiscByte & 0xC0) >> 6;

                        $thisfile_mpeg_audio_lame['noise_shaping'] = $thisfile_mpeg_audio_lame_raw['noise_shaping'];

                        $thisfile_mpeg_audio_lame['stereo_mode'] = getid3_mp3 :: LAMEmiscStereoModeLookup($thisfile_mpeg_audio_lame_raw['stereo_mode']);

                        $thisfile_mpeg_audio_lame['not_optimal_quality'] = (bool) $thisfile_mpeg_audio_lame_raw['not_optimal_quality'];

                        $thisfile_mpeg_audio_lame['source_sample_freq'] = getid3_mp3 :: LAMEmiscSourceSampleFrequencyLookup($thisfile_mpeg_audio_lame_raw['source_sample_freq']);

                        

                        // byte $B5  MP3 Gain
                        $thisfile_mpeg_audio_lame_raw['mp3_gain'] = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB5, 1), false, true);

                        $thisfile_mpeg_audio_lame['mp3_gain_db'] = (getid3_lib :: RGADamplitude2dB(2) / 4) * $thisfile_mpeg_audio_lame_raw['mp3_gain'];

                        $thisfile_mpeg_audio_lame['mp3_gain_factor'] = pow(2, ($thisfile_mpeg_audio_lame['mp3_gain_db'] / 6));

                        

                        // bytes $B6-$B7  Preset and surround info
                        $PresetSurroundBytes = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB6, 2));

                        // Reserved                                                    = ($PresetSurroundBytes & 0xC000);
                        $thisfile_mpeg_audio_lame_raw['surround_info'] = ($PresetSurroundBytes & 0x3800);

                        $thisfile_mpeg_audio_lame['surround_info'] = getid3_mp3 :: LAMEsurroundInfoLookup($thisfile_mpeg_audio_lame_raw['surround_info']);

                        $thisfile_mpeg_audio_lame['preset_used_id'] = ($PresetSurroundBytes & 0x07FF);

                        $thisfile_mpeg_audio_lame['preset_used'] = getid3_mp3 :: LAMEpresetUsedLookup($thisfile_mpeg_audio_lame);

                        if (! empty($thisfile_mpeg_audio_lame['preset_used_id']) && empty($thisfile_mpeg_audio_lame['preset_used']))

                        {

                            $ThisFileInfo['warning'][] = 'Unknown LAME preset used (' . $thisfile_mpeg_audio_lame['preset_used_id'] . ') - please report to info@getid3.org';

                        }

                        if (($thisfile_mpeg_audio_lame['short_version'] == 'LAME3.90.') && ! empty($thisfile_mpeg_audio_lame['preset_used_id']))

                        {

                            // this may change if 3.90.4 ever comes out
                            $thisfile_mpeg_audio_lame['short_version'] = 'LAME3.90.3';

                        }

                        

                        // bytes $B8-$BB  MusicLength
                        $thisfile_mpeg_audio_lame['audio_bytes'] = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB8, 4));

                        $ExpectedNumberOfAudioBytes = (($thisfile_mpeg_audio_lame['audio_bytes'] > 0) ? $thisfile_mpeg_audio_lame['audio_bytes'] : $thisfile_mpeg_audio['VBR_bytes']);

                        

                        // bytes $BC-$BD  MusicCRC
                        $thisfile_mpeg_audio_lame['music_crc'] = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBC, 2));

                        

                        // bytes $BE-$BF  CRC-16 of Info Tag
                        $thisfile_mpeg_audio_lame['lame_tag_crc'] = getid3_lib :: BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBE, 2));

                        

                        // LAME CBR
                        if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1)

                        {

                            

                            $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';

                            $thisfile_mpeg_audio['bitrate'] = getid3_mp3 :: ClosestStandardMP3Bitrate($thisfile_mpeg_audio['bitrate']);

                            $ThisFileInfo['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];

                        

     //if (empty($thisfile_mpeg_audio['bitrate']) || (!empty($thisfile_mpeg_audio_lame['bitrate_min']) && ($thisfile_mpeg_audio_lame['bitrate_min'] != 255))) {
                        //	$thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio_lame['bitrate_min'];
                        //}
                        



                        }

                    

                    }

                }

            

            }

            else

            {

                

                // not Fraunhofer or Xing VBR methods, most likely CBR (but could be VBR with no header)
                $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';

                if ($recursivesearch)

                {

                    $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';

                    if (getid3_mp3 :: RecursiveFrameScanning($fd, $ThisFileInfo, $offset, $nextframetestoffset, true))

                    {

                        $recursivesearch = false;

                        $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';

                    }

                    if ($thisfile_mpeg_audio['bitrate_mode'] == 'vbr')

                    {

                        $ThisFileInfo['warning'][] = 'VBR file with no VBR header. Bitrate values calculated from actual frame bitrates.';

                    }

                }

            

            }

        

        }

        

        if (($ExpectedNumberOfAudioBytes > 0) && ($ExpectedNumberOfAudioBytes != ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset'])))

        {

            if ($ExpectedNumberOfAudioBytes > ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']))

            {

                if (@$ThisFileInfo['fileformat'] == 'riff')

                {

                    // ignore, audio data is broken into chunks so will always be data "missing"
                }

                elseif (($ExpectedNumberOfAudioBytes - ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset'])) == 1)

                {

                    $ThisFileInfo['warning'][] = 'Last byte of data truncated (this is a known bug in Meracl ID3 Tag Writer before v1.3.5)';

                }

                else

                {

                    $ThisFileInfo['warning'][] = 'Probable truncated file: expecting ' . $ExpectedNumberOfAudioBytes . ' bytes of audio data, only found ' . ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) . ' (short by ' . ($ExpectedNumberOfAudioBytes - ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset'])) . ' bytes)';

                }

            }

            else

            {

                if ((($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) - $ExpectedNumberOfAudioBytes) == 1)

                {

                    //	$prenullbytefileoffset = ftell($fd);
                    //	fseek($fd, $ThisFileInfo['avdataend'], SEEK_SET);
                    //	$PossibleNullByte = fread($fd, 1);
                    //	fseek($fd, $prenullbytefileoffset, SEEK_SET);
                    //	if ($PossibleNullByte === "\x00") {
                    $ThisFileInfo['avdataend'] --;

                

     //		$ThisFileInfo['warning'][] = 'Extra null byte at end of MP3 data assumed to be RIFF padding and therefore ignored';
                //	} else {
                //		$ThisFileInfo['warning'][] = 'Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']).' ('.(($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)';
                //	}
                }

                else

                {

                    $ThisFileInfo['warning'][] = 'Too much data in file: expecting ' . $ExpectedNumberOfAudioBytes . ' bytes of audio data, found ' . ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) . ' (' . (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) - $ExpectedNumberOfAudioBytes) . ' bytes too many)';

                }

            }

        }

        

        if (($thisfile_mpeg_audio['bitrate'] == 'free') && empty($ThisFileInfo['audio']['bitrate']))

        {

            if (($offset == $ThisFileInfo['avdataoffset']) && empty($thisfile_mpeg_audio['VBR_frames']))

            {

                $framebytelength = getid3_mp3 :: FreeFormatFrameLength($fd, $offset, $ThisFileInfo, true);

                if ($framebytelength > 0)

                {

                    $thisfile_mpeg_audio['framelength'] = $framebytelength;

                    if ($thisfile_mpeg_audio['layer'] == '1')

                    {

                        // BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
                        $ThisFileInfo['audio']['bitrate'] = ((($framebytelength / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;

                    }

                    else

                    {

                        // Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
                        $ThisFileInfo['audio']['bitrate'] = (($framebytelength - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;

                    }

                }

                else

                {

                    $ThisFileInfo['error'][] = 'Error calculating frame length of free-format MP3 without Xing/LAME header';

                }

            }

        }

        

        if (@$thisfile_mpeg_audio['VBR_frames'])

        {

            switch ($thisfile_mpeg_audio['bitrate_mode'])

            {

                case 'vbr' :

                case 'abr' :

                    if (($thisfile_mpeg_audio['version'] == '1') && ($thisfile_mpeg_audio['layer'] == 1))

                    {

                        $thisfile_mpeg_audio['VBR_bitrate'] = ((@$thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames']) * 8) * ($ThisFileInfo['audio']['sample_rate'] / 384);

                    }

                    elseif ((($thisfile_mpeg_audio['version'] == '2') || ($thisfile_mpeg_audio['version'] == '2.5')) && ($thisfile_mpeg_audio['layer'] == 3))

                    {

                        $thisfile_mpeg_audio['VBR_bitrate'] = ((@$thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames']) * 8) * ($ThisFileInfo['audio']['sample_rate'] / 576);

                    }

                    else

                    {

                        $thisfile_mpeg_audio['VBR_bitrate'] = ((@$thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames']) * 8) * ($ThisFileInfo['audio']['sample_rate'] / 1152);

                    }

                    if ($thisfile_mpeg_audio['VBR_bitrate'] > 0)

                    {

                        $ThisFileInfo['audio']['bitrate'] = $thisfile_mpeg_audio['VBR_bitrate'];

                        $thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio['VBR_bitrate']; // to avoid confusion
                    }

                    break;

            }

        }

        

        // End variable-bitrate headers
        ////////////////////////////////////////////////////////////////////////////////////
        



        if ($recursivesearch)

        {

            

            if (! getid3_mp3 :: RecursiveFrameScanning($fd, $ThisFileInfo, $offset, $nextframetestoffset, $ScanAsCBR))

            {

                return false;

            }

        

        }

        

        //if (false) {
        //    // experimental side info parsing section - not returning anything useful yet
        //
        //    $SideInfoBitstream = getid3_lib::BigEndian2Bin($SideInfoData);
        //    $SideInfoOffset = 0;
        //
        //    if ($thisfile_mpeg_audio['version'] == '1') {
        //        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
        //            // MPEG-1 (mono)
        //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
        //            $SideInfoOffset += 9;
        //            $SideInfoOffset += 5;
        //        } else {
        //            // MPEG-1 (stereo, joint-stereo, dual-channel)
        //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
        //            $SideInfoOffset += 9;
        //            $SideInfoOffset += 3;
        //        }
        //    } else { // 2 or 2.5
        //        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
        //            // MPEG-2, MPEG-2.5 (mono)
        //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
        //            $SideInfoOffset += 8;
        //            $SideInfoOffset += 1;
        //        } else {
        //            // MPEG-2, MPEG-2.5 (stereo, joint-stereo, dual-channel)
        //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
        //            $SideInfoOffset += 8;
        //            $SideInfoOffset += 2;
        //        }
        //    }
        //
        //    if ($thisfile_mpeg_audio['version'] == '1') {
        //        for ($channel = 0; $channel < $ThisFileInfo['audio']['channels']; $channel++) {
        //            for ($scfsi_band = 0; $scfsi_band < 4; $scfsi_band++) {
        //                $thisfile_mpeg_audio['scfsi'][$channel][$scfsi_band] = substr($SideInfoBitstream, $SideInfoOffset, 1);
        //                $SideInfoOffset += 2;
        //            }
        //        }
        //    }
        //    for ($granule = 0; $granule < (($thisfile_mpeg_audio['version'] == '1') ? 2 : 1); $granule++) {
        //        for ($channel = 0; $channel < $ThisFileInfo['audio']['channels']; $channel++) {
        //            $thisfile_mpeg_audio['part2_3_length'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 12);
        //            $SideInfoOffset += 12;
        //            $thisfile_mpeg_audio['big_values'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
        //            $SideInfoOffset += 9;
        //            $thisfile_mpeg_audio['global_gain'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 8);
        //            $SideInfoOffset += 8;
        //            if ($thisfile_mpeg_audio['version'] == '1') {
        //                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
        //                $SideInfoOffset += 4;
        //            } else {
        //                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
        //                $SideInfoOffset += 9;
        //            }
        //            $thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
        //            $SideInfoOffset += 1;
        //
        //            if ($thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] == '1') {
        //
        //                $thisfile_mpeg_audio['block_type'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 2);
        //                $SideInfoOffset += 2;
        //                $thisfile_mpeg_audio['mixed_block_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
        //                $SideInfoOffset += 1;
        //
        //                for ($region = 0; $region < 2; $region++) {
        //                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
        //                    $SideInfoOffset += 5;
        //                }
        //                $thisfile_mpeg_audio['table_select'][$granule][$channel][2] = 0;
        //
        //                for ($window = 0; $window < 3; $window++) {
        //                    $thisfile_mpeg_audio['subblock_gain'][$granule][$channel][$window] = substr($SideInfoBitstream, $SideInfoOffset, 3);
        //                    $SideInfoOffset += 3;
        //                }
        //
        //            } else {
        //
        //                for ($region = 0; $region < 3; $region++) {
        //                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
        //                    $SideInfoOffset += 5;
        //                }
        //
        //                $thisfile_mpeg_audio['region0_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
        //                $SideInfoOffset += 4;
        //                $thisfile_mpeg_audio['region1_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 3);
        //                $SideInfoOffset += 3;
        //                $thisfile_mpeg_audio['block_type'][$granule][$channel] = 0;
        //            }
        //
        //            if ($thisfile_mpeg_audio['version'] == '1') {
        //                $thisfile_mpeg_audio['preflag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
        //                $SideInfoOffset += 1;
        //            }
        //            $thisfile_mpeg_audio['scalefac_scale'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
        //            $SideInfoOffset += 1;
        //            $thisfile_mpeg_audio['count1table_select'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
        //            $SideInfoOffset += 1;
        //        }
        //    }
        //}
        



        return true;

    }



    function RecursiveFrameScanning(&$fd, &$ThisFileInfo, &$offset, &$nextframetestoffset, $ScanAsCBR)

    {

        for($i = 0; $i < GETID3_MP3_VALID_CHECK_FRAMES; $i ++)

        {

            // check next GETID3_MP3_VALID_CHECK_FRAMES frames for validity, to make sure we haven't run across a false synch
            if (($nextframetestoffset + 4) >= $ThisFileInfo['avdataend'])

            {

                // end of file
                return true;

            }

            

            $nextframetestarray = array('error' => '', 'warning' => '', 'avdataend' => $ThisFileInfo['avdataend'], 

                    'avdataoffset' => $ThisFileInfo['avdataoffset']);

            if (getid3_mp3 :: decodeMPEGaudioHeader($fd, $nextframetestoffset, $nextframetestarray, false))

            {

                if ($ScanAsCBR)

                {

                    // force CBR mode, used for trying to pick out invalid audio streams with
                    // valid(?) VBR headers, or VBR streams with no VBR header
                    if (! isset($nextframetestarray['mpeg']['audio']['bitrate']) || ! isset($ThisFileInfo['mpeg']['audio']['bitrate']) || ($nextframetestarray['mpeg']['audio']['bitrate'] != $ThisFileInfo['mpeg']['audio']['bitrate']))

                    {

                        return false;

                    }

                }

                

                // next frame is OK, get ready to check the one after that
                if (isset($nextframetestarray['mpeg']['audio']['framelength']) && ($nextframetestarray['mpeg']['audio']['framelength'] > 0))

                {

                    $nextframetestoffset += $nextframetestarray['mpeg']['audio']['framelength'];

                }

                else

                {

                    $ThisFileInfo['error'][] = 'Frame at offset (' . $offset . ') is has an invalid frame length.';

                    return false;

                }

            

            }

            else

            {

                

                // next frame is not valid, note the error and fail, so scanning can contiue for a valid frame sequence
                $ThisFileInfo['error'][] = 'Frame at offset (' . $offset . ') is valid, but the next one at (' . $nextframetestoffset . ') is not.';

                

                return false;

            }

        }

        return true;

    }



    function FreeFormatFrameLength($fd, $offset, &$ThisFileInfo, $deepscan = false)

    {

        fseek($fd, $offset, SEEK_SET);

        $MPEGaudioData = fread($fd, 32768);

        

        $SyncPattern1 = substr($MPEGaudioData, 0, 4);

        // may be different pattern due to padding
        $SyncPattern2 = $SyncPattern1{0} . $SyncPattern1{1} . chr(ord($SyncPattern1{2}) | 0x02) . $SyncPattern1{3};

        if ($SyncPattern2 === $SyncPattern1)

        {

            $SyncPattern2 = $SyncPattern1{0} . $SyncPattern1{1} . chr(ord($SyncPattern1{2}) & 0xFD) . $SyncPattern1{3};

        }

        

        $framelength = false;

        $framelength1 = strpos($MPEGaudioData, $SyncPattern1, 4);

        $framelength2 = strpos($MPEGaudioData, $SyncPattern2, 4);

        if ($framelength1 > 4)

        {

            $framelength = $framelength1;

        }

        if (($framelength2 > 4) && ($framelength2 < $framelength1))

        {

            $framelength = $framelength2;

        }

        if (! $framelength)

        {

            

            // LAME 3.88 has a different value for modeextension on the first frame vs the rest
            $framelength1 = strpos($MPEGaudioData, substr($SyncPattern1, 0, 3), 4);

            $framelength2 = strpos($MPEGaudioData, substr($SyncPattern2, 0, 3), 4);

            

            if ($framelength1 > 4)

            {

                $framelength = $framelength1;

            }

            if (($framelength2 > 4) && ($framelength2 < $framelength1))

            {

                $framelength = $framelength2;

            }

            if (! $framelength)

            {

                $ThisFileInfo['error'][] = 'Cannot find next free-format synch pattern (' . getid3_lib :: PrintHexBytes($SyncPattern1) . ' or ' . getid3_lib :: PrintHexBytes($SyncPattern2) . ') after offset ' . $offset;

                return false;

            }

            else

            {

                $ThisFileInfo['warning'][] = 'ModeExtension varies between first frame and other frames (known free-format issue in LAME 3.88)';

                $ThisFileInfo['audio']['codec'] = 'LAME';

                $ThisFileInfo['audio']['encoder'] = 'LAME3.88';

                $SyncPattern1 = substr($SyncPattern1, 0, 3);

                $SyncPattern2 = substr($SyncPattern2, 0, 3);

            }

        }

        

        if ($deepscan)

        {

            

            $ActualFrameLengthValues = array();

            $nextoffset = $offset + $framelength;

            while ($nextoffset < ($ThisFileInfo['avdataend'] - 6))

            {

                fseek($fd, $nextoffset - 1, SEEK_SET);

                $NextSyncPattern = fread($fd, 6);

                if ((substr($NextSyncPattern, 1, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 1, strlen($SyncPattern2)) == $SyncPattern2))

                {

                    // good - found where expected
                    $ActualFrameLengthValues[] = $framelength;

                }

                elseif ((substr($NextSyncPattern, 0, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 0, strlen($SyncPattern2)) == $SyncPattern2))

                {

                    // ok - found one byte earlier than expected (last frame wasn't padded, first frame was)
                    $ActualFrameLengthValues[] = ($framelength - 1);

                    $nextoffset --;

                }

                elseif ((substr($NextSyncPattern, 2, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 2, strlen($SyncPattern2)) == $SyncPattern2))

                {

                    // ok - found one byte later than expected (last frame was padded, first frame wasn't)
                    $ActualFrameLengthValues[] = ($framelength + 1);

                    $nextoffset ++;

                }

                else

                {

                    $ThisFileInfo['error'][] = 'Did not find expected free-format sync pattern at offset ' . $nextoffset;

                    return false;

                }

                $nextoffset += $framelength;

            }

            if (count($ActualFrameLengthValues) > 0)

            {

                $framelength = intval(round(array_sum($ActualFrameLengthValues) / count($ActualFrameLengthValues)));

            }

        }

        return $framelength;

    }



    function getOnlyMPEGaudioInfoBruteForce($fd, &$ThisFileInfo)

    {

        

        $MPEGaudioHeaderDecodeCache = array();

        $MPEGaudioHeaderValidCache = array();

        $MPEGaudioHeaderLengthCache = array();

        $MPEGaudioVersionLookup = getid3_mp3 :: MPEGaudioVersionArray();

        $MPEGaudioLayerLookup = getid3_mp3 :: MPEGaudioLayerArray();

        $MPEGaudioBitrateLookup = getid3_mp3 :: MPEGaudioBitrateArray();

        $MPEGaudioFrequencyLookup = getid3_mp3 :: MPEGaudioFrequencyArray();

        $MPEGaudioChannelModeLookup = getid3_mp3 :: MPEGaudioChannelModeArray();

        $MPEGaudioModeExtensionLookup = getid3_mp3 :: MPEGaudioModeExtensionArray();

        $MPEGaudioEmphasisLookup = getid3_mp3 :: MPEGaudioEmphasisArray();

        $LongMPEGversionLookup = array();

        $LongMPEGlayerLookup = array();

        $LongMPEGbitrateLookup = array();

        $LongMPEGpaddingLookup = array();

        $LongMPEGfrequencyLookup = array();

        

        $Distribution['bitrate'] = array();

        $Distribution['frequency'] = array();

        $Distribution['layer'] = array();

        $Distribution['version'] = array();

        $Distribution['padding'] = array();

        

        fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);

        

        $max_frames_scan = 5000;

        $frames_scanned = 0;

        

        $previousvalidframe = $ThisFileInfo['avdataoffset'];

        while (ftell($fd) < $ThisFileInfo['avdataend'])

        {

            set_time_limit(30);

            $head4 = fread($fd, 4);

            if (strlen($head4) < 4)

            {

                break;

            }

            if ($head4{0} != "\xFF")

            {

                for($i = 1; $i < 4; $i ++)

                {

                    if ($head4{$i} == "\xFF")

                    {

                        fseek($fd, $i - 4, SEEK_CUR);

                        continue 2;

                    }

                }

                continue;

            }

            if (! isset($MPEGaudioHeaderDecodeCache[$head4]))

            {

                $MPEGaudioHeaderDecodeCache[$head4] = getid3_mp3 :: MPEGaudioHeaderDecode($head4);

            }

            if (! isset($MPEGaudioHeaderValidCache[$head4]))

            {

                $MPEGaudioHeaderValidCache[$head4] = getid3_mp3 :: MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$head4], false, false);

            }

            if ($MPEGaudioHeaderValidCache[$head4])

            {

                

                if (! isset($MPEGaudioHeaderLengthCache[$head4]))

                {

                    $LongMPEGversionLookup[$head4] = $MPEGaudioVersionLookup[$MPEGaudioHeaderDecodeCache[$head4]['version']];

                    $LongMPEGlayerLookup[$head4] = $MPEGaudioLayerLookup[$MPEGaudioHeaderDecodeCache[$head4]['layer']];

                    $LongMPEGbitrateLookup[$head4] = $MPEGaudioBitrateLookup[$LongMPEGversionLookup[$head4]][$LongMPEGlayerLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['bitrate']];

                    $LongMPEGpaddingLookup[$head4] = (bool) $MPEGaudioHeaderDecodeCache[$head4]['padding'];

                    $LongMPEGfrequencyLookup[$head4] = $MPEGaudioFrequencyLookup[$LongMPEGversionLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['sample_rate']];

                    $MPEGaudioHeaderLengthCache[$head4] = getid3_mp3 :: MPEGaudioFrameLength($LongMPEGbitrateLookup[$head4], $LongMPEGversionLookup[$head4], $LongMPEGlayerLookup[$head4], $LongMPEGpaddingLookup[$head4], $LongMPEGfrequencyLookup[$head4]);

                }

                if ($MPEGaudioHeaderLengthCache[$head4] > 4)

                {

                    $WhereWeWere = ftell($fd);

                    fseek($fd, $MPEGaudioHeaderLengthCache[$head4] - 4, SEEK_CUR);

                    $next4 = fread($fd, 4);

                    if ($next4{0} == "\xFF")

                    {

                        if (! isset($MPEGaudioHeaderDecodeCache[$next4]))

                        {

                            $MPEGaudioHeaderDecodeCache[$next4] = getid3_mp3 :: MPEGaudioHeaderDecode($next4);

                        }

                        if (! isset($MPEGaudioHeaderValidCache[$next4]))

                        {

                            $MPEGaudioHeaderValidCache[$next4] = getid3_mp3 :: MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$next4], false, false);

                        }

                        if ($MPEGaudioHeaderValidCache[$next4])

                        {

                            fseek($fd, - 4, SEEK_CUR);

                            

                            @$Distribution['bitrate'][$LongMPEGbitrateLookup[$head4]] ++;

                            @$Distribution['layer'][$LongMPEGlayerLookup[$head4]] ++;

                            @$Distribution['version'][$LongMPEGversionLookup[$head4]] ++;

                            @$Distribution['padding'][intval($LongMPEGpaddingLookup[$head4])] ++;

                            @$Distribution['frequency'][$LongMPEGfrequencyLookup[$head4]] ++;

                            if ($max_frames_scan && (++ $frames_scanned >= $max_frames_scan))

                            {

                                $pct_data_scanned = (ftell($fd) - $ThisFileInfo['avdataoffset']) / ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']);

                                $ThisFileInfo['warning'][] = 'too many MPEG audio frames to scan, only scanned first ' . $max_frames_scan . ' frames (' . number_format($pct_data_scanned * 100, 1) . '% of file) and extrapolated distribution, playtime and bitrate may be incorrect.';

                                foreach ($Distribution as $key1 => $value1)

                                {

                                    foreach ($value1 as $key2 => $value2)

                                    {

                                        $Distribution[$key1][$key2] = round($value2 / $pct_data_scanned);

                                    }

                                }

                                break;

                            }

                            continue;

                        }

                    }

                    unset($next4);

                    fseek($fd, $WhereWeWere - 3, SEEK_SET);

                }

            

            }

        }

        foreach ($Distribution as $key => $value)

        {

            ksort($Distribution[$key], SORT_NUMERIC);

        }

        ksort($Distribution['version'], SORT_STRING);

        $ThisFileInfo['mpeg']['audio']['bitrate_distribution'] = $Distribution['bitrate'];

        $ThisFileInfo['mpeg']['audio']['frequency_distribution'] = $Distribution['frequency'];

        $ThisFileInfo['mpeg']['audio']['layer_distribution'] = $Distribution['layer'];

        $ThisFileInfo['mpeg']['audio']['version_distribution'] = $Distribution['version'];

        $ThisFileInfo['mpeg']['audio']['padding_distribution'] = $Distribution['padding'];

        if (count($Distribution['version']) > 1)

        {

            $ThisFileInfo['error'][] = 'Corrupt file - more than one MPEG version detected';

        }

        if (count($Distribution['layer']) > 1)

        {

            $ThisFileInfo['error'][] = 'Corrupt file - more than one MPEG layer detected';

        }

        if (count($Distribution['frequency']) > 1)

        {

            $ThisFileInfo['error'][] = 'Corrupt file - more than one MPEG sample rate detected';

        }

        

        $bittotal = 0;

        foreach ($Distribution['bitrate'] as $bitratevalue => $bitratecount)

        {

            if ($bitratevalue != 'free')

            {

                $bittotal += ($bitratevalue * $bitratecount);

            }

        }

        $ThisFileInfo['mpeg']['audio']['frame_count'] = array_sum($Distribution['bitrate']);

        if ($ThisFileInfo['mpeg']['audio']['frame_count'] == 0)

        {

            $ThisFileInfo['error'][] = 'no MPEG audio frames found';

            return false;

        }

        $ThisFileInfo['mpeg']['audio']['bitrate'] = ($bittotal / $ThisFileInfo['mpeg']['audio']['frame_count']);

        $ThisFileInfo['mpeg']['audio']['bitrate_mode'] = ((count($Distribution['bitrate']) > 0) ? 'vbr' : 'cbr');

        $ThisFileInfo['mpeg']['audio']['sample_rate'] = getid3_lib :: array_max($Distribution['frequency'], true);

        

        $ThisFileInfo['audio']['bitrate'] = $ThisFileInfo['mpeg']['audio']['bitrate'];

        $ThisFileInfo['audio']['bitrate_mode'] = $ThisFileInfo['mpeg']['audio']['bitrate_mode'];

        $ThisFileInfo['audio']['sample_rate'] = $ThisFileInfo['mpeg']['audio']['sample_rate'];

        $ThisFileInfo['audio']['dataformat'] = 'mp' . getid3_lib :: array_max($Distribution['layer'], true);

        $ThisFileInfo['fileformat'] = $ThisFileInfo['audio']['dataformat'];

        

        return true;

    }



    function getOnlyMPEGaudioInfo($fd, &$ThisFileInfo, $avdataoffset, $BitrateHistogram = false)

    {

        

        // looks for synch, decodes MPEG audio header
        



        static $MPEGaudioVersionLookup;

        static $MPEGaudioLayerLookup;

        static $MPEGaudioBitrateLookup;

        if (empty($MPEGaudioVersionLookup))

        {

            $MPEGaudioVersionLookup = getid3_mp3 :: MPEGaudioVersionArray();

            $MPEGaudioLayerLookup = getid3_mp3 :: MPEGaudioLayerArray();

            $MPEGaudioBitrateLookup = getid3_mp3 :: MPEGaudioBitrateArray();

        

        }

        

        fseek($fd, $avdataoffset, SEEK_SET);

        $sync_seek_buffer_size = min(128 * 1024, $ThisFileInfo['avdataend'] - $avdataoffset);

        if ($sync_seek_buffer_size <= 0)

        {

            $ThisFileInfo['error'][] = 'Invalid $sync_seek_buffer_size at offset ' . $avdataoffset;

            return false;

        }

        $header = fread($fd, $sync_seek_buffer_size);

        $sync_seek_buffer_size = strlen($header);

        $SynchSeekOffset = 0;

        while ($SynchSeekOffset < $sync_seek_buffer_size)

        {

            

            if ((($avdataoffset + $SynchSeekOffset) < $ThisFileInfo['avdataend']) && ! feof($fd))

            {

                

                if ($SynchSeekOffset > $sync_seek_buffer_size)

                {

                    // if a synch's not found within the first 128k bytes, then give up
                    $ThisFileInfo['error'][] = 'Could not find valid MPEG audio synch within the first ' . round($sync_seek_buffer_size / 1024) . 'kB';

                    if (isset($ThisFileInfo['audio']['bitrate']))

                    {

                        unset($ThisFileInfo['audio']['bitrate']);

                    }

                    if (isset($ThisFileInfo['mpeg']['audio']))

                    {

                        unset($ThisFileInfo['mpeg']['audio']);

                    }

                    if (empty($ThisFileInfo['mpeg']))

                    {

                        unset($ThisFileInfo['mpeg']);

                    }

                    return false;

                

                }

                elseif (feof($fd))

                {

                    

                    $ThisFileInfo['error'][] = 'Could not find valid MPEG audio synch before end of file';

                    if (isset($ThisFileInfo['audio']['bitrate']))

                    {

                        unset($ThisFileInfo['audio']['bitrate']);

                    }

                    if (isset($ThisFileInfo['mpeg']['audio']))

                    {

                        unset($ThisFileInfo['mpeg']['audio']);

                    }

                    if (isset($ThisFileInfo['mpeg']) && (! is_array($ThisFileInfo['mpeg']) || (count($ThisFileInfo['mpeg']) == 0)))

                    {

                        unset($ThisFileInfo['mpeg']);

                    }

                    return false;

                }

            }

            

            if (($SynchSeekOffset + 1) >= strlen($header))

            {

                $ThisFileInfo['error'][] = 'Could not find valid MPEG synch before end of file';

                return false;

            }

            

            if (($header{$SynchSeekOffset} == "\xFF") && ($header{($SynchSeekOffset + 1)} > "\xE0"))

            { // synch detected
                



                if (! isset($FirstFrameThisfileInfo) && ! isset($ThisFileInfo['mpeg']['audio']))

                {

                    $FirstFrameThisfileInfo = $ThisFileInfo;

                    $FirstFrameAVDataOffset = $avdataoffset + $SynchSeekOffset;

                    if (! getid3_mp3 :: decodeMPEGaudioHeader($fd, $avdataoffset + $SynchSeekOffset, $FirstFrameThisfileInfo, false))

                    {

                        // if this is the first valid MPEG-audio frame, save it in case it's a VBR header frame and there's
                        // garbage between this frame and a valid sequence of MPEG-audio frames, to be restored below
                        unset($FirstFrameThisfileInfo);

                    }

                }

                

                $dummy = $ThisFileInfo; // only overwrite real data if valid header found
                if (getid3_mp3 :: decodeMPEGaudioHeader($fd, $avdataoffset + $SynchSeekOffset, $dummy, true))

                {

                    $ThisFileInfo = $dummy;

                    $ThisFileInfo['avdataoffset'] = $avdataoffset + $SynchSeekOffset;

                    switch (@$ThisFileInfo['fileformat'])

                    {

                        case '' :

                        case 'id3' :

                        case 'ape' :

                        case 'mp3' :

                            $ThisFileInfo['fileformat'] = 'mp3';

                            $ThisFileInfo['audio']['dataformat'] = 'mp3';

                            break;

                    }

                    if (isset($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode']) && ($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode'] == 'vbr'))

                    {

                        if (! (abs($ThisFileInfo['audio']['bitrate'] - $FirstFrameThisfileInfo['audio']['bitrate']) <= 1))

                        {

                            // If there is garbage data between a valid VBR header frame and a sequence
                            // of valid MPEG-audio frames the VBR data is no longer discarded.
                            $ThisFileInfo = $FirstFrameThisfileInfo;

                            $ThisFileInfo['avdataoffset'] = $FirstFrameAVDataOffset;

                            $ThisFileInfo['fileformat'] = 'mp3';

                            $ThisFileInfo['audio']['dataformat'] = 'mp3';

                            $dummy = $ThisFileInfo;

                            unset($dummy['mpeg']['audio']);

                            $GarbageOffsetStart = $FirstFrameAVDataOffset + $FirstFrameThisfileInfo['mpeg']['audio']['framelength'];

                            $GarbageOffsetEnd = $avdataoffset + $SynchSeekOffset;

                            if (getid3_mp3 :: decodeMPEGaudioHeader($fd, $GarbageOffsetEnd, $dummy, true, true))

                            {

                                

                                $ThisFileInfo = $dummy;

                                $ThisFileInfo['avdataoffset'] = $GarbageOffsetEnd;

                                $ThisFileInfo['warning'][] = 'apparently-valid VBR header not used because could not find ' . GETID3_MP3_VALID_CHECK_FRAMES . ' consecutive MPEG-audio frames immediately after VBR header (garbage data for ' . ($GarbageOffsetEnd - $GarbageOffsetStart) . ' bytes between ' . $GarbageOffsetStart . ' and ' . $GarbageOffsetEnd . '), but did find valid CBR stream starting at ' . $GarbageOffsetEnd;

                            

                            }

                            else

                            {

                                

                                $ThisFileInfo['warning'][] = 'using data from VBR header even though could not find ' . GETID3_MP3_VALID_CHECK_FRAMES . ' consecutive MPEG-audio frames immediately after VBR header (garbage data for ' . ($GarbageOffsetEnd - $GarbageOffsetStart) . ' bytes between ' . $GarbageOffsetStart . ' and ' . $GarbageOffsetEnd . ')';

                            

                            }

                        }

                    }

                    if (isset($ThisFileInfo['mpeg']['audio']['bitrate_mode']) && ($ThisFileInfo['mpeg']['audio']['bitrate_mode'] == 'vbr') && ! isset($ThisFileInfo['mpeg']['audio']['VBR_method']))

                    {

                        // VBR file with no VBR header
                        $BitrateHistogram = true;

                    }

                    

                    if ($BitrateHistogram)

                    {

                        

                        $ThisFileInfo['mpeg']['audio']['stereo_distribution'] = array('stereo' => 0, 'joint stereo' => 0, 

                                'dual channel' => 0, 'mono' => 0);

                        $ThisFileInfo['mpeg']['audio']['version_distribution'] = array('1' => 0, '2' => 0, '2.5' => 0);

                        

                        if ($ThisFileInfo['mpeg']['audio']['version'] == '1')

                        {

                            if ($ThisFileInfo['mpeg']['audio']['layer'] == 3)

                            {

                                $ThisFileInfo['mpeg']['audio']['bitrate_distribution'] = array('free' => 0, 32000 => 0, 

                                        40000 => 0, 48000 => 0, 56000 => 0, 64000 => 0, 80000 => 0, 96000 => 0, 

                                        112000 => 0, 128000 => 0, 160000 => 0, 192000 => 0, 224000 => 0, 256000 => 0, 

                                        320000 => 0);

                            }

                            elseif ($ThisFileInfo['mpeg']['audio']['layer'] == 2)

                            {

                                $ThisFileInfo['mpeg']['audio']['bitrate_distribution'] = array('free' => 0, 32000 => 0, 

                                        48000 => 0, 56000 => 0, 64000 => 0, 80000 => 0, 96000 => 0, 112000 => 0, 

                                        128000 => 0, 160000 => 0, 192000 => 0, 224000 => 0, 256000 => 0, 320000 => 0, 

                                        384000 => 0);

                            }

                            elseif ($ThisFileInfo['mpeg']['audio']['layer'] == 1)

                            {

                                $ThisFileInfo['mpeg']['audio']['bitrate_distribution'] = array('free' => 0, 32000 => 0, 

                                        64000 => 0, 96000 => 0, 128000 => 0, 160000 => 0, 192000 => 0, 224000 => 0, 

                                        256000 => 0, 288000 => 0, 320000 => 0, 352000 => 0, 384000 => 0, 416000 => 0, 

                                        448000 => 0);

                            }

                        }

                        elseif ($ThisFileInfo['mpeg']['audio']['layer'] == 1)

                        {

                            $ThisFileInfo['mpeg']['audio']['bitrate_distribution'] = array('free' => 0, 32000 => 0, 

                                    48000 => 0, 56000 => 0, 64000 => 0, 80000 => 0, 96000 => 0, 112000 => 0, 128000 => 0, 

                                    144000 => 0, 160000 => 0, 176000 => 0, 192000 => 0, 224000 => 0, 256000 => 0);

                        }

                        else

                        {

                            $ThisFileInfo['mpeg']['audio']['bitrate_distribution'] = array('free' => 0, 8000 => 0, 

                                    16000 => 0, 24000 => 0, 32000 => 0, 40000 => 0, 48000 => 0, 56000 => 0, 64000 => 0, 

                                    80000 => 0, 96000 => 0, 112000 => 0, 128000 => 0, 144000 => 0, 160000 => 0);

                        }

                        

                        $dummy = array('error' => $ThisFileInfo['error'], 'warning' => $ThisFileInfo['warning'], 

                                'avdataend' => $ThisFileInfo['avdataend'], 'avdataoffset' => $ThisFileInfo['avdataoffset']);

                        $synchstartoffset = $ThisFileInfo['avdataoffset'];

                        fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);

                        

                        // you can play with these numbers:
                        $max_frames_scan = 50000;

                        $max_scan_segments = 10;

                        

                        // don't play with these numbers:
                        $FastMode = false;

                        $SynchErrorsFound = 0;

                        $frames_scanned = 0;

                        $this_scan_segment = 0;

                        $frames_scan_per_segment = ceil($max_frames_scan / $max_scan_segments);

                        $pct_data_scanned = 0;

                        for($current_segment = 0; $current_segment < $max_scan_segments; $current_segment ++)

                        {

                            //echo 'was at '.ftell($fd).'<br>';
                            $frames_scanned_this_segment = 0;

                            if (ftell($fd) >= $ThisFileInfo['avdataend'])

                            {

                                //echo 'breaking because current position ('.ftell($fd).') is >= $ThisFileInfo[avdataend] ('.$ThisFileInfo['avdataend'].')<br>';
                                break;

                            }

                            $scan_start_offset[$current_segment] = max(ftell($fd), $ThisFileInfo['avdataoffset'] + round($current_segment * (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) / $max_scan_segments)));

                            //echo 'start at '.$scan_start_offset[$current_segment].'<br>';
                            if ($current_segment > 0)

                            {

                                fseek($fd, $scan_start_offset[$current_segment], SEEK_SET);

                                $buffer_4k = fread($fd, 4096);

                                for($j = 0; $j < (strlen($buffer_4k) - 4); $j ++)

                                {

                                    if (($buffer_4k{$j} == "\xFF") && ($buffer_4k{($j + 1)} > "\xE0"))

                                    { // synch detected
                                        if (getid3_mp3 :: decodeMPEGaudioHeader($fd, $scan_start_offset[$current_segment] + $j, $dummy, false, false, $FastMode))

                                        {

                                            $calculated_next_offset = $scan_start_offset[$current_segment] + $j + $dummy['mpeg']['audio']['framelength'];

                                            if (getid3_mp3 :: decodeMPEGaudioHeader($fd, $calculated_next_offset, $dummy, false, false, $FastMode))

                                            {

                                                $scan_start_offset[$current_segment] += $j;

                                                break;

                                            }

                                            else

                                            {

                                                //echo 'header['.__LINE__.'] at '.($calculated_next_offset).' invalid<br>';
                                            }

                                        }

                                        else

                                        {

                                            //echo 'header['.__LINE__.'] at '.($scan_start_offset[$current_segment] + $j).' invalid<br>';
                                        }

                                    }

                                }

                            }

                            //echo 'actually start at '.$scan_start_offset[$current_segment].'<br>';
                            $synchstartoffset = $scan_start_offset[$current_segment];

                            while (getid3_mp3 :: decodeMPEGaudioHeader($fd, $synchstartoffset, $dummy, false, false, $FastMode))

                            {

                                $FastMode = true;

                                $thisframebitrate = $MPEGaudioBitrateLookup[$MPEGaudioVersionLookup[$dummy['mpeg']['audio']['raw']['version']]][$MPEGaudioLayerLookup[$dummy['mpeg']['audio']['raw']['layer']]][$dummy['mpeg']['audio']['raw']['bitrate']];

                                

                                if (empty($dummy['mpeg']['audio']['framelength']))

                                {

                                    $SynchErrorsFound ++;

                                    $synchstartoffset ++;

                                

     //echo ' [ďż˝] ';
                                }

                                else

                                {

                                    //echo ' . ';
                                    @$ThisFileInfo['mpeg']['audio']['bitrate_distribution'][$thisframebitrate] ++;

                                    @$ThisFileInfo['mpeg']['audio']['stereo_distribution'][$dummy['mpeg']['audio']['channelmode']] ++;

                                    @$ThisFileInfo['mpeg']['audio']['version_distribution'][$dummy['mpeg']['audio']['version']] ++;

                                    

                                    $synchstartoffset += $dummy['mpeg']['audio']['framelength'];

                                }

                                $frames_scanned ++;

                                if ($frames_scan_per_segment && (++ $frames_scanned_this_segment >= $frames_scan_per_segment))

                                {

                                    $this_pct_scanned = (ftell($fd) - $scan_start_offset[$current_segment]) / ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']);

                                    if (($current_segment == 0) && (($this_pct_scanned * $max_scan_segments) >= 1))

                                    {

                                        // file likely contains < $max_frames_scan, just scan as one segment
                                        $max_scan_segments = 1;

                                        $frames_scan_per_segment = $max_frames_scan;

                                    }

                                    else

                                    {

                                        $pct_data_scanned += $this_pct_scanned;

                                        //var_dump($pct_data_scanned);
                                        //exit;
                                        break;

                                    }

                                }

                            }

                        

     //echo '<hr>';
                        }

                        if ($pct_data_scanned > 0)

                        {

                            $ThisFileInfo['warning'][] = 'too many MPEG audio frames to scan, only scanned ' . $frames_scanned . ' frames in ' . $max_scan_segments . ' segments (' . number_format($pct_data_scanned * 100, 1) . '% of file) and extrapolated distribution, playtime and bitrate may be incorrect.';

                            foreach ($ThisFileInfo['mpeg']['audio'] as $key1 => $value1)

                            {

                                if (! eregi('_distribution$', $key1))

                                {

                                    continue;

                                }

                                foreach ($value1 as $key2 => $value2)

                                {

                                    $ThisFileInfo['mpeg']['audio'][$key1][$key2] = round($value2 / $pct_data_scanned);

                                }

                            }

                        }

                        

                        if ($SynchErrorsFound > 0)

                        {

                            $ThisFileInfo['warning'][] = 'Found ' . $SynchErrorsFound . ' synch errors in histogram analysis';

                        

     //return false;
                        }

                        

                        $bittotal = 0;

                        $framecounter = 0;

                        foreach ($ThisFileInfo['mpeg']['audio']['bitrate_distribution'] as $bitratevalue => $bitratecount)

                        {

                            $framecounter += $bitratecount;

                            if ($bitratevalue != 'free')

                            {

                                $bittotal += ($bitratevalue * $bitratecount);

                            }

                        }

                        if ($framecounter == 0)

                        {

                            $ThisFileInfo['error'][] = 'Corrupt MP3 file: framecounter == zero';

                            return false;

                        }

                        $ThisFileInfo['mpeg']['audio']['frame_count'] = getid3_lib :: CastAsInt($framecounter);

                        $ThisFileInfo['mpeg']['audio']['bitrate'] = ($bittotal / $framecounter);

                        

                        $ThisFileInfo['audio']['bitrate'] = $ThisFileInfo['mpeg']['audio']['bitrate'];

                        

                        // Definitively set VBR vs CBR, even if the Xing/LAME/VBRI header says differently
                        $distinct_bitrates = 0;

                        foreach ($ThisFileInfo['mpeg']['audio']['bitrate_distribution'] as $bitrate_value => $bitrate_count)

                        {

                            if ($bitrate_count > 0)

                            {

                                $distinct_bitrates ++;

                            }

                        }

                        if ($distinct_bitrates > 1)

                        {

                            $ThisFileInfo['mpeg']['audio']['bitrate_mode'] = 'vbr';

                        }

                        else

                        {

                            $ThisFileInfo['mpeg']['audio']['bitrate_mode'] = 'cbr';

                        }

                        $ThisFileInfo['audio']['bitrate_mode'] = $ThisFileInfo['mpeg']['audio']['bitrate_mode'];

                    

                    }

                    

                    break; // exit while()
                }

            }

            

            $SynchSeekOffset ++;

            if (($avdataoffset + $SynchSeekOffset) >= $ThisFileInfo['avdataend'])

            {

                // end of file/data
                



                if (empty($ThisFileInfo['mpeg']['audio']))

                {

                    

                    $ThisFileInfo['error'][] = 'could not find valid MPEG synch before end of file';

                    if (isset($ThisFileInfo['audio']['bitrate']))

                    {

                        unset($ThisFileInfo['audio']['bitrate']);

                    }

                    if (isset($ThisFileInfo['mpeg']['audio']))

                    {

                        unset($ThisFileInfo['mpeg']['audio']);

                    }

                    if (isset($ThisFileInfo['mpeg']) && (! is_array($ThisFileInfo['mpeg']) || empty($ThisFileInfo['mpeg'])))

                    {

                        unset($ThisFileInfo['mpeg']);

                    }

                    return false;

                

                }

                break;

            }

        

        }

        $ThisFileInfo['audio']['channels'] = $ThisFileInfo['mpeg']['audio']['channels'];

        $ThisFileInfo['audio']['channelmode'] = $ThisFileInfo['mpeg']['audio']['channelmode'];

        $ThisFileInfo['audio']['sample_rate'] = $ThisFileInfo['mpeg']['audio']['sample_rate'];

        return true;

    }



    function MPEGaudioVersionArray()

    {

        static $MPEGaudioVersion = array('2.5', false, '2', '1');

        return $MPEGaudioVersion;

    }



    function MPEGaudioLayerArray()

    {

        static $MPEGaudioLayer = array(false, 3, 2, 1);

        return $MPEGaudioLayer;

    }



    function MPEGaudioBitrateArray()

    {

        static $MPEGaudioBitrate;

        if (empty($MPEGaudioBitrate))

        {

            $MPEGaudioBitrate = array(

                    '1' => array(

                            1 => array('free', 32000, 64000, 96000, 128000, 160000, 192000, 224000, 256000, 288000, 

                                    320000, 352000, 384000, 416000, 448000), 

                            2 => array('free', 32000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 160000, 192000, 

                                    224000, 256000, 320000, 384000), 

                            3 => array('free', 32000, 40000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 160000, 

                                    192000, 224000, 256000, 320000)), 

                    

                    '2' => array(

                            1 => array('free', 32000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 144000, 160000, 

                                    176000, 192000, 224000, 256000), 

                            2 => array('free', 8000, 16000, 24000, 32000, 40000, 48000, 56000, 64000, 80000, 96000, 

                                    112000, 128000, 144000, 160000)));

            $MPEGaudioBitrate['2'][3] = $MPEGaudioBitrate['2'][2];

            $MPEGaudioBitrate['2.5'] = $MPEGaudioBitrate['2'];

        }

        return $MPEGaudioBitrate;

    }



    function MPEGaudioFrequencyArray()

    {

        static $MPEGaudioFrequency;

        if (empty($MPEGaudioFrequency))

        {

            $MPEGaudioFrequency = array('1' => array(44100, 48000, 32000), '2' => array(22050, 24000, 16000), 

                    '2.5' => array(11025, 12000, 8000));

        }

        return $MPEGaudioFrequency;

    }



    function MPEGaudioChannelModeArray()

    {

        static $MPEGaudioChannelMode = array('stereo', 'joint stereo', 'dual channel', 'mono');

        return $MPEGaudioChannelMode;

    }



    function MPEGaudioModeExtensionArray()

    {

        static $MPEGaudioModeExtension;

        if (empty($MPEGaudioModeExtension))

        {

            $MPEGaudioModeExtension = array(1 => array('4-31', '8-31', '12-31', '16-31'), 

                    2 => array('4-31', '8-31', '12-31', '16-31'), 3 => array('', 'IS', 'MS', 'IS+MS'));

        }

        return $MPEGaudioModeExtension;

    }



    function MPEGaudioEmphasisArray()

    {

        static $MPEGaudioEmphasis = array('none', '50/15ms', false, 'CCIT J.17');

        return $MPEGaudioEmphasis;

    }



    function MPEGaudioHeaderBytesValid($head4, $allowBitrate15 = false)

    {

        return getid3_mp3 :: MPEGaudioHeaderValid(getid3_mp3 :: MPEGaudioHeaderDecode($head4), false, $allowBitrate15);

    }



    function MPEGaudioHeaderValid($rawarray, $echoerrors = false, $allowBitrate15 = false)

    {

        if (($rawarray['synch'] & 0x0FFE) != 0x0FFE)

        {

            return false;

        }

        

        static $MPEGaudioVersionLookup;

        static $MPEGaudioLayerLookup;

        static $MPEGaudioBitrateLookup;

        static $MPEGaudioFrequencyLookup;

        static $MPEGaudioChannelModeLookup;

        static $MPEGaudioModeExtensionLookup;

        static $MPEGaudioEmphasisLookup;

        if (empty($MPEGaudioVersionLookup))

        {

            $MPEGaudioVersionLookup = getid3_mp3 :: MPEGaudioVersionArray();

            $MPEGaudioLayerLookup = getid3_mp3 :: MPEGaudioLayerArray();

            $MPEGaudioBitrateLookup = getid3_mp3 :: MPEGaudioBitrateArray();

            $MPEGaudioFrequencyLookup = getid3_mp3 :: MPEGaudioFrequencyArray();

            $MPEGaudioChannelModeLookup = getid3_mp3 :: MPEGaudioChannelModeArray();

            $MPEGaudioModeExtensionLookup = getid3_mp3 :: MPEGaudioModeExtensionArray();

            $MPEGaudioEmphasisLookup = getid3_mp3 :: MPEGaudioEmphasisArray();

        }

        

        if (isset($MPEGaudioVersionLookup[$rawarray['version']]))

        {

            $decodedVersion = $MPEGaudioVersionLookup[$rawarray['version']];

        }

        else

        {

            echo ($echoerrors ? "\n" . 'invalid Version (' . $rawarray['version'] . ')' : '');

            return false;

        }

        if (isset($MPEGaudioLayerLookup[$rawarray['layer']]))

        {

            $decodedLayer = $MPEGaudioLayerLookup[$rawarray['layer']];

        }

        else

        {

            echo ($echoerrors ? "\n" . 'invalid Layer (' . $rawarray['layer'] . ')' : '');

            return false;

        }

        if (! isset($MPEGaudioBitrateLookup[$decodedVersion][$decodedLayer][$rawarray['bitrate']]))

        {

            echo ($echoerrors ? "\n" . 'invalid Bitrate (' . $rawarray['bitrate'] . ')' : '');

            if ($rawarray['bitrate'] == 15)

            {

                // known issue in LAME 3.90 - 3.93.1 where free-format has bitrate ID of 15 instead of 0
                // let it go through here otherwise file will not be identified
                if (! $allowBitrate15)

                {

                    return false;

                }

            }

            else

            {

                return false;

            }

        }

        if (! isset($MPEGaudioFrequencyLookup[$decodedVersion][$rawarray['sample_rate']]))

        {

            echo ($echoerrors ? "\n" . 'invalid Frequency (' . $rawarray['sample_rate'] . ')' : '');

            return false;

        }

        if (! isset($MPEGaudioChannelModeLookup[$rawarray['channelmode']]))

        {

            echo ($echoerrors ? "\n" . 'invalid ChannelMode (' . $rawarray['channelmode'] . ')' : '');

            return false;

        }

        if (! isset($MPEGaudioModeExtensionLookup[$decodedLayer][$rawarray['modeextension']]))

        {

            echo ($echoerrors ? "\n" . 'invalid Mode Extension (' . $rawarray['modeextension'] . ')' : '');

            return false;

        }

        if (! isset($MPEGaudioEmphasisLookup[$rawarray['emphasis']]))

        {

            echo ($echoerrors ? "\n" . 'invalid Emphasis (' . $rawarray['emphasis'] . ')' : '');

            return false;

        }

        // These are just either set or not set, you can't mess that up :)
        // $rawarray['protection'];
        // $rawarray['padding'];
        // $rawarray['private'];
        // $rawarray['copyright'];
        // $rawarray['original'];
        



        return true;

    }



    function MPEGaudioHeaderDecode($Header4Bytes)

    {

        // AAAA AAAA  AAAB BCCD  EEEE FFGH  IIJJ KLMM
        // A - Frame sync (all bits set)
        // B - MPEG Audio version ID
        // C - Layer description
        // D - Protection bit
        // E - Bitrate index
        // F - Sampling rate frequency index
        // G - Padding bit
        // H - Private bit
        // I - Channel Mode
        // J - Mode extension (Only if Joint stereo)
        // K - Copyright
        // L - Original
        // M - Emphasis
        



        if (strlen($Header4Bytes) != 4)

        {

            return false;

        }

        

        $MPEGrawHeader['synch'] = (getid3_lib :: BigEndian2Int(substr($Header4Bytes, 0, 2)) & 0xFFE0) >> 4;

        $MPEGrawHeader['version'] = (ord($Header4Bytes{1}) & 0x18) >> 3; //    BB
        $MPEGrawHeader['layer'] = (ord($Header4Bytes{1}) & 0x06) >> 1; //      CC
        $MPEGrawHeader['protection'] = (ord($Header4Bytes{1}) & 0x01); //        D
        $MPEGrawHeader['bitrate'] = (ord($Header4Bytes{2}) & 0xF0) >> 4; // EEEE
        $MPEGrawHeader['sample_rate'] = (ord($Header4Bytes{2}) & 0x0C) >> 2; //     FF
        $MPEGrawHeader['padding'] = (ord($Header4Bytes{2}) & 0x02) >> 1; //       G
        $MPEGrawHeader['private'] = (ord($Header4Bytes{2}) & 0x01); //        H
        $MPEGrawHeader['channelmode'] = (ord($Header4Bytes{3}) & 0xC0) >> 6; // II
        $MPEGrawHeader['modeextension'] = (ord($Header4Bytes{3}) & 0x30) >> 4; //   JJ
        $MPEGrawHeader['copyright'] = (ord($Header4Bytes{3}) & 0x08) >> 3; //     K
        $MPEGrawHeader['original'] = (ord($Header4Bytes{3}) & 0x04) >> 2; //      L
        $MPEGrawHeader['emphasis'] = (ord($Header4Bytes{3}) & 0x03); //       MM
        



        return $MPEGrawHeader;

    }



    function MPEGaudioFrameLength(&$bitrate, &$version, &$layer, $padding, &$samplerate)

    {

        static $AudioFrameLengthCache = array();

        

        if (! isset($AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate]))

        {

            $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = false;

            if ($bitrate != 'free')

            {

                

                if ($version == '1')

                {

                    

                    if ($layer == '1')

                    {

                        

                        // For Layer I slot is 32 bits long
                        $FrameLengthCoefficient = 48;

                        $SlotLength = 4;

                    

                    }

                    else

                    { // Layer 2 / 3
                        



                        // for Layer 2 and Layer 3 slot is 8 bits long.
                        $FrameLengthCoefficient = 144;

                        $SlotLength = 1;

                    

                    }

                

                }

                else

                { // MPEG-2 / MPEG-2.5
                    



                    if ($layer == '1')

                    {

                        

                        // For Layer I slot is 32 bits long
                        $FrameLengthCoefficient = 24;

                        $SlotLength = 4;

                    

                    }

                    elseif ($layer == '2')

                    {

                        

                        // for Layer 2 and Layer 3 slot is 8 bits long.
                        $FrameLengthCoefficient = 144;

                        $SlotLength = 1;

                    

                    }

                    else

                    { // layer 3
                        



                        // for Layer 2 and Layer 3 slot is 8 bits long.
                        $FrameLengthCoefficient = 72;

                        $SlotLength = 1;

                    

                    }

                

                }

                

                // FrameLengthInBytes = ((Coefficient * BitRate) / SampleRate) + Padding
                if ($samplerate > 0)

                {

                    $NewFramelength = ($FrameLengthCoefficient * $bitrate) / $samplerate;

                    $NewFramelength = floor($NewFramelength / $SlotLength) * $SlotLength; // round to next-lower multiple of SlotLength (1 byte for Layer 2/3, 4 bytes for Layer I)
                    if ($padding)

                    {

                        $NewFramelength += $SlotLength;

                    }

                    $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = (int) $NewFramelength;

                }

            }

        }

        return $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate];

    }



    function ClosestStandardMP3Bitrate($bitrate)

    {

        static $StandardBitrates = array(320000, 256000, 224000, 192000, 160000, 128000, 112000, 96000, 80000, 64000, 

                56000, 48000, 40000, 32000, 24000, 16000, 8000);

        static $BitrateTable = array(0 => '-');

        $roundbitrate = intval(round($bitrate, - 3));

        if (! isset($BitrateTable[$roundbitrate]))

        {

            if ($roundbitrate > 320000)

            {

                $BitrateTable[$roundbitrate] = round($bitrate, - 4);

            }

            else

            {

                $LastBitrate = 320000;

                foreach ($StandardBitrates as $StandardBitrate)

                {

                    $BitrateTable[$roundbitrate] = $StandardBitrate;

                    if ($roundbitrate >= $StandardBitrate - (($LastBitrate - $StandardBitrate) / 2))

                    {

                        break;

                    }

                    $LastBitrate = $StandardBitrate;

                }

            }

        }

        return $BitrateTable[$roundbitrate];

    }



    function XingVBRidOffset($version, $channelmode)

    {

        static $XingVBRidOffsetCache = array();

        if (empty($XingVBRidOffset))

        {

            $XingVBRidOffset = array(

                    '1' => array('mono' => 0x15, // 4 + 17 = 21
'stereo' => 0x24, // 4 + 32 = 36
'joint stereo' => 0x24, 'dual channel' => 0x24), 

                    

                    '2' => array('mono' => 0x0D, // 4 +  9 = 13
'stereo' => 0x15, // 4 + 17 = 21
'joint stereo' => 0x15, 'dual channel' => 0x15), 

                    

                    '2.5' => array('mono' => 0x15, 'stereo' => 0x15, 'joint stereo' => 0x15, 'dual channel' => 0x15));

        }

        return $XingVBRidOffset[$version][$channelmode];

    }



    function LAMEvbrMethodLookup($VBRmethodID)

    {

        static $LAMEvbrMethodLookup = array(0x00 => 'unknown', 0x01 => 'cbr', 0x02 => 'abr', 0x03 => 'vbr-old / vbr-rh', 

                0x04 => 'vbr-new / vbr-mtrh', 0x05 => 'vbr-mt', 0x06 => 'vbr (full vbr method 4)', 

                0x08 => 'cbr (constant bitrate 2 pass)', 0x09 => 'abr (2 pass)', 0x0F => 'reserved');

        return (isset($LAMEvbrMethodLookup[$VBRmethodID]) ? $LAMEvbrMethodLookup[$VBRmethodID] : '');

    }



    function LAMEmiscStereoModeLookup($StereoModeID)

    {

        static $LAMEmiscStereoModeLookup = array(0 => 'mono', 1 => 'stereo', 2 => 'dual mono', 3 => 'joint stereo', 

                4 => 'forced stereo', 5 => 'auto', 6 => 'intensity stereo', 7 => 'other');

        return (isset($LAMEmiscStereoModeLookup[$StereoModeID]) ? $LAMEmiscStereoModeLookup[$StereoModeID] : '');

    }



    function LAMEmiscSourceSampleFrequencyLookup($SourceSampleFrequencyID)

    {

        static $LAMEmiscSourceSampleFrequencyLookup = array(0 => '<= 32 kHz', 1 => '44.1 kHz', 2 => '48 kHz', 

                3 => '> 48kHz');

        return (isset($LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID]) ? $LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID] : '');

    }



    function LAMEsurroundInfoLookup($SurroundInfoID)

    {

        static $LAMEsurroundInfoLookup = array(0 => 'no surround info', 1 => 'DPL encoding', 2 => 'DPL2 encoding', 

                3 => 'Ambisonic encoding');

        return (isset($LAMEsurroundInfoLookup[$SurroundInfoID]) ? $LAMEsurroundInfoLookup[$SurroundInfoID] : 'reserved');

    }



    function LAMEpresetUsedLookup($LAMEtag)

    {

        

        if ($LAMEtag['preset_used_id'] == 0)

        {

            // no preset used (LAME >=3.93)
            // no preset recorded (LAME <3.93)
            return '';

        }

        $LAMEpresetUsedLookup = array();

        

        /////  THIS PART CANNOT BE STATIC .
        for($i = 8; $i <= 320; $i ++)

        {

            switch ($LAMEtag['vbr_method'])

            {

                case 'cbr' :

                    $LAMEpresetUsedLookup[$i] = '--alt-preset ' . $LAMEtag['vbr_method'] . ' ' . $i;

                    break;

                case 'abr' :

                default : // other VBR modes shouldn't be here(?)
                    $LAMEpresetUsedLookup[$i] = '--alt-preset ' . $i;

                    break;

            }

        }

        

        // named old-style presets (studio, phone, voice, etc) are handled in GuessEncoderOptions()
        



        // named alt-presets
        $LAMEpresetUsedLookup[1000] = '--r3mix';

        $LAMEpresetUsedLookup[1001] = '--alt-preset standard';

        $LAMEpresetUsedLookup[1002] = '--alt-preset extreme';

        $LAMEpresetUsedLookup[1003] = '--alt-preset insane';

        $LAMEpresetUsedLookup[1004] = '--alt-preset fast standard';

        $LAMEpresetUsedLookup[1005] = '--alt-preset fast extreme';

        $LAMEpresetUsedLookup[1006] = '--alt-preset medium';

        $LAMEpresetUsedLookup[1007] = '--alt-preset fast medium';

        

        // LAME 3.94 additions/changes
        $LAMEpresetUsedLookup[1010] = '--preset portable'; // 3.94a15 Oct 21 2003
        $LAMEpresetUsedLookup[1015] = '--preset radio'; // 3.94a15 Oct 21 2003
        



        $LAMEpresetUsedLookup[320] = '--preset insane'; // 3.94a15 Nov 12 2003
        $LAMEpresetUsedLookup[410] = '-V9';

        $LAMEpresetUsedLookup[420] = '-V8';

        $LAMEpresetUsedLookup[440] = '-V6';

        $LAMEpresetUsedLookup[430] = '--preset radio'; // 3.94a15 Nov 12 2003
        $LAMEpresetUsedLookup[450] = '--preset ' . (($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '') . 'portable'; // 3.94a15 Nov 12 2003
        $LAMEpresetUsedLookup[460] = '--preset ' . (($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '') . 'medium'; // 3.94a15 Nov 12 2003
        $LAMEpresetUsedLookup[470] = '--r3mix'; // 3.94b1  Dec 18 2003
        $LAMEpresetUsedLookup[480] = '--preset ' . (($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '') . 'standard'; // 3.94a15 Nov 12 2003
        $LAMEpresetUsedLookup[490] = '-V1';

        $LAMEpresetUsedLookup[500] = '--preset ' . (($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '') . 'extreme'; // 3.94a15 Nov 12 2003
        



        return (isset($LAMEpresetUsedLookup[$LAMEtag['preset_used_id']]) ? $LAMEpresetUsedLookup[$LAMEtag['preset_used_id']] : 'new/unknown preset: ' . $LAMEtag['preset_used_id'] . ' - report to info@getid3.org');

    }



}



?>