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mikeschinkel/module.audio.mp3.php

Created March 16, 2020 01:35
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module.audio.mp3.php from WordPress where decodeMPEGaudioHeader() is partially refactored from over 600 lines to ~200 lines.
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module.audio.mp3.php
<?php
/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org> //
// available at https://github.com/JamesHeinrich/getID3 //
// or https://www.getid3.org //
// or http://getid3.sourceforge.net //
// 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 extends getid3_handler
{
/**
* 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-unusable files.
*
* @var bool
*/
public $allow_bruteforce = false;
/**
* @return bool
*/
public function Analyze() {
$info = &$this->getid3->info;
$initialOffset = $info['avdataoffset'];
if (!$this->getOnlyMPEGaudioInfo($info['avdataoffset'])) {
if ($this->allow_bruteforce) {
$this->error('Rescanning file in BruteForce mode');
$this->getOnlyMPEGaudioInfoBruteForce();
}
}
if (isset($info['mpeg']['audio']['bitrate_mode'])) {
$info['audio']['bitrate_mode'] = strtolower($info['mpeg']['audio']['bitrate_mode']);
}
if (((isset($info['id3v2']['headerlength']) && ($info['avdataoffset'] > $info['id3v2']['headerlength'])) || (!isset($info['id3v2']) && ($info['avdataoffset'] > 0) && ($info['avdataoffset'] != $initialOffset)))) {
$synchoffsetwarning = 'Unknown data before synch ';
if (isset($info['id3v2']['headerlength'])) {
$synchoffsetwarning .= '(ID3v2 header ends at '.$info['id3v2']['headerlength'].', then '.($info['avdataoffset'] - $info['id3v2']['headerlength']).' bytes garbage, ';
} elseif ($initialOffset > 0) {
$synchoffsetwarning .= '(should be at '.$initialOffset.', ';
} else {
$synchoffsetwarning .= '(should be at beginning of file, ';
}
$synchoffsetwarning .= 'synch detected at '.$info['avdataoffset'].')';
if (isset($info['audio']['bitrate_mode']) && ($info['audio']['bitrate_mode'] == 'cbr')) {
if (!empty($info['id3v2']['headerlength']) && (($info['avdataoffset'] - $info['id3v2']['headerlength']) == $info['mpeg']['audio']['framelength'])) {
$synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90-3.92) DLL in CBR mode.';
$info['audio']['codec'] = 'LAME';
$CurrentDataLAMEversionString = 'LAME3.';
} elseif (empty($info['id3v2']['headerlength']) && ($info['avdataoffset'] == $info['mpeg']['audio']['framelength'])) {
$synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90 - 3.92) DLL in CBR mode.';
$info['audio']['codec'] = 'LAME';
$CurrentDataLAMEversionString = 'LAME3.';
}
}
$this->warning($synchoffsetwarning);
}
if (isset($info['mpeg']['audio']['LAME'])) {
$info['audio']['codec'] = 'LAME';
if (!empty($info['mpeg']['audio']['LAME']['long_version'])) {
$info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['long_version'], "\x00");
} elseif (!empty($info['mpeg']['audio']['LAME']['short_version'])) {
$info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['short_version'], "\x00");
}
}
$CurrentDataLAMEversionString = (!empty($CurrentDataLAMEversionString) ? $CurrentDataLAMEversionString : (isset($info['audio']['encoder']) ? $info['audio']['encoder'] : ''));
if (!empty($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 = $info['avdataend'] - $PossiblyLongerLAMEversion_FrameLength;
$this->fseek($PossibleLAMEversionStringOffset);
$PossiblyLongerLAMEversion_Data = $this->fread($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($PossiblyLongerLAMEversion_String, 'LAME0123456789., (abcdefghijklmnopqrstuvwxyzJFSOND)')); //"LAME3.90.3" "LAME3.87 (beta 1, Sep 27 2000)" "LAME3.88 (beta)"
if (empty($info['audio']['encoder']) || (strlen($PossiblyLongerLAMEversion_NewString) > strlen($info['audio']['encoder']))) {
$info['audio']['encoder'] = $PossiblyLongerLAMEversion_NewString;
}
}
}
}
if (!empty($info['audio']['encoder'])) {
$info['audio']['encoder'] = rtrim($info['audio']['encoder'], "\x00 ");
}
switch (isset($info['mpeg']['audio']['layer']) ? $info['mpeg']['audio']['layer'] : '') {
case 1:
case 2:
$info['audio']['dataformat'] = 'mp'.$info['mpeg']['audio']['layer'];
break;
}
if (isset($info['fileformat']) && ($info['fileformat'] == 'mp3')) {
switch ($info['audio']['dataformat']) {
case 'mp1':
case 'mp2':
case 'mp3':
$info['fileformat'] = $info['audio']['dataformat'];
break;
default:
$this->warning('Expecting [audio][dataformat] to be mp1/mp2/mp3 when fileformat == mp3, [audio][dataformat] actually "'.$info['audio']['dataformat'].'"');
break;
}
}
if (empty($info['fileformat'])) {
unset($info['fileformat']);
unset($info['audio']['bitrate_mode']);
unset($info['avdataoffset']);
unset($info['avdataend']);
return false;
}
$info['mime_type'] = 'audio/mpeg';
$info['audio']['lossless'] = false;
// Calculate playtime
if (!isset($info['playtime_seconds']) && isset($info['audio']['bitrate']) && ($info['audio']['bitrate'] > 0)) {
// https://github.com/JamesHeinrich/getID3/issues/161
// VBR header frame contains ~0.026s of silent audio data, but is not actually part of the original encoding and should be ignored
$xingVBRheaderFrameLength = ((isset($info['mpeg']['audio']['VBR_frames']) && isset($info['mpeg']['audio']['framelength'])) ? $info['mpeg']['audio']['framelength'] : 0);
$info['playtime_seconds'] = ($info['avdataend'] - $info['avdataoffset'] - $xingVBRheaderFrameLength) * 8 / $info['audio']['bitrate'];
}
$info['audio']['encoder_options'] = $this->GuessEncoderOptions();
return true;
}
/**
* @return string
*/
public function GuessEncoderOptions() {
// shortcuts
$info = &$this->getid3->info;
$thisfile_mpeg_audio = array();
$thisfile_mpeg_audio_lame = array();
if (!empty($info['mpeg']['audio'])) {
$thisfile_mpeg_audio = &$info['mpeg']['audio'];
if (!empty($thisfile_mpeg_audio['LAME'])) {
$thisfile_mpeg_audio_lame = &$thisfile_mpeg_audio['LAME'];
}
}
$encoder_options = '';
static $NamedPresetBitrates = array(16, 24, 40, 56, 112, 128, 160, 192, 256);
if (isset($thisfile_mpeg_audio['VBR_method']) && ($thisfile_mpeg_audio['VBR_method'] == 'Fraunhofer') && !empty($thisfile_mpeg_audio['VBR_quality'])) {
$encoder_options = 'VBR q'.$thisfile_mpeg_audio['VBR_quality'];
} elseif (!empty($thisfile_mpeg_audio_lame['preset_used']) && isset($thisfile_mpeg_audio_lame['preset_used_id']) && (!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']][$thisfile_mpeg_audio_lame['lowpass_frequency']];
} elseif ($info['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'.$LAME_q_value;
} elseif ($info['audio']['bitrate_mode'] == 'cbr') {
$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
} else {
$encoder_options = strtoupper($info['audio']['bitrate_mode']);
}
} elseif (!empty($thisfile_mpeg_audio_lame['bitrate_abr'])) {
$encoder_options = 'ABR'.$thisfile_mpeg_audio_lame['bitrate_abr'];
} elseif (!empty($info['audio']['bitrate'])) {
if ($info['audio']['bitrate_mode'] == 'cbr') {
$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
} else {
$encoder_options = strtoupper($info['audio']['bitrate_mode']);
}
}
if (!empty($thisfile_mpeg_audio_lame['bitrate_min'])) {
$encoder_options .= ' -b'.$thisfile_mpeg_audio_lame['bitrate_min'];
}
if (!empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev']) || !empty($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($encoder_options) && !empty($info['audio']['bitrate']) && !empty($info['audio']['bitrate_mode'])) {
//$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
$encoder_options = strtoupper($info['audio']['bitrate_mode']);
}
return $encoder_options;
}
private static $MPEGaudio;
private function getMPEGaudio() {
return array(
'VersionLookup' => self::MPEGaudioVersionArray(),
'LayerLookup' => self::MPEGaudioLayerArray(),
'BitrateLookup' => self::MPEGaudioBitrateArray(),
'FrequencyLookup' => self::MPEGaudioFrequencyArray(),
'ChannelModeLookup' => self::MPEGaudioChannelModeArray(),
'ModeExtensionLookup' => self::MPEGaudioModeExtensionArray(),
'EmphasisLookup' => self::MPEGaudioEmphasisArray(),
'HeaderDecodeCache' => array(),
'HeaderValidCache' => array(),
);
}
private function annotateHeader(array &$audio, string $header) {
$audio = array_merge( $audio, array(
'version' => self::$MPEGaudio['VersionLookup'][$audio['raw']['version']],
'layer' => self::$MPEGaudio['LayerLookup'][$audio['raw']['layer']],
'channelmode' => self::$MPEGaudio['ChannelModeLookup'][$audio['raw']['channelmode']],
'channels' => (($audio['channelmode'] == 'mono') ? 1 : 2),
'sample_rate' => self::$MPEGaudio['FrequencyLookup'][$audio['version']][$audio['raw']['sample_rate']],
'modeextension' => self::$MPEGaudio['ModeExtensionLookup'][$audio['layer']][$audio['raw']['modeextension']],
'emphasis' => self::$MPEGaudio['EmphasisLookup'][$audio['raw']['emphasis']],
'protection' => !$audio['raw']['protection'],
'private' => (bool) $audio['raw']['private'],
'copyright' => (bool) $audio['raw']['copyright'],
'original' => (bool) $audio['raw']['original'],
));
if ($audio['protection']) {
$audio['crc'] = getid3_lib::BigEndian2Int(substr($header, 4, 2));
}
}
private function isValidBitrate(array $audio){
$is_valid = false;
switch ($audio['channelmode']) {
case 'mono':
if (($audio['bitrate'] == 'free') || ($audio['bitrate'] <= 192000)) {
$is_valid = true;
} else {
$this->error($audio['bitrate'].'kbps not allowed in Layer 2, '.$audio['channelmode'].'.');
}
break;
case 'stereo':
case 'joint stereo':
case 'dual channel':
if (($audio['bitrate'] == 'free') || ($audio['bitrate'] == 64000) || ($audio['bitrate'] >= 96000)) {
$is_valid = true;
} else {
$this->error(intval(round($audio['bitrate'] / 1000)).'kbps not allowed in Layer 2, '.$audio['channelmode'].'.');
}
break;
default:
$is_valid = true;
}
return $is_valid;
}
private function annotate_Fraunhofer_VBR(array &$audio, string $header, int $offset ) {
$audio['bitrate_mode'] = 'vbr';
$audio['VBR_method'] = 'Fraunhofer';
$SideInfoData = substr($header, 4 + 2, 32);
$FraunhoferVBROffset = 36;
$properties = array(
4 => 'VBR_encoder_version' , // VbriVersion
6 => 'VBR_encoder_delay' , // VbriDelay
8 => 'VBR_quality' , // VbriQuality
10 => 'VBR_bytes' , // VbriStreamBytes
14 => 'VBR_frames' , // VbriStreamFrames
18 => 'VBR_seek_offsets' , // VbriTableSize
20 => 'VBR_seek_scale' , // VbriTableScale
22 => 'VBR_entry_bytes' , // VbriEntryBytes
24 => 'VBR_entry_frames' , // VbriEntryFrames
);
foreach( $properties as $pos => $property_name ) {
$audio[ $property_name ] = getid3_lib::BigEndian2Int(substr($header, $FraunhoferVBROffset + $pos, 2));
}
$previousbyteoffset = $offset;
for ($i = 0; $i < $audio['VBR_seek_offsets']; $i++) {
$Fraunhofer_OffsetN = getid3_lib::BigEndian2Int(substr($header, $FraunhoferVBROffset, $audio['VBR_entry_bytes']));
$FraunhoferVBROffset += $audio['VBR_entry_bytes'];
$audio['VBR_offsets_relative'][$i] = ($Fraunhofer_OffsetN * $audio['VBR_seek_scale']);
$audio['VBR_offsets_absolute'][$i] = ($Fraunhofer_OffsetN * $audio['VBR_seek_scale']) + $previousbyteoffset;
$previousbyteoffset += $Fraunhofer_OffsetN;
}
}
private function annnotate_Xing_VBR( array &$audio, string $header, int $offset, bool &$recursivesearch ) {
do {
// 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 = self::XingVBRidOffset( $audio[ 'version' ], $audio[ 'channelmode' ] );
$SideInfoData = substr( $header, 4 + 2, $VBRidOffset - 4 );
// 'Xing' is traditional Xing VBR frame
// 'Info' is LAME-encoded CBR (This was done to avoid CBR files to be recognized as traditional Xing VBR files by some decoders.)
// 'Info' *can* legally be used to specify a VBR file as well, however.
// http://www.multiweb.cz/twoinches/MP3inside.htm
//00..03 = "Xing" or "Info"
//04..07 = Flags:
// 0x01 Frames Flag set if value for number of frames in file is stored
// 0x02 Bytes Flag set if value for filesize in bytes is stored
// 0x04 TOC Flag set if values for TOC are stored
// 0x08 VBR Scale Flag set if values for VBR scale is stored
//08..11 Frames: Number of frames in file (including the first Xing/Info one)
//12..15 Bytes: File length in Bytes
//16..115 TOC (Table of Contents):
// Contains of 100 indexes (one Byte length) for easier lookup in file. Approximately solves problem with moving inside file.
// Each Byte has a value according this formula:
// (TOC[i] / 256) * fileLenInBytes
// So if song lasts eg. 240 sec. and you want to jump to 60. sec. (and file is 5 000 000 Bytes length) you can use:
// TOC[(60/240)*100] = TOC[25]
// and corresponding Byte in file is then approximately at:
// (TOC[25]/256) * 5000000
//116..119 VBR Scale
if ( ! preg_match( '#^(Xing|Info)$#', substr( $header, $VBRidOffset, 4 ) ) ) {
// not Fraunhofer or Xing VBR methods, most likely CBR (but could be VBR with no header)
$audio[ 'bitrate_mode' ] = 'cbr';
if ( ! $recursivesearch ) {
break;
}
$audio[ 'bitrate_mode' ] = 'vbr';
if ( ! $this->RecursiveFrameScanning( $offset, $nextframetestoffset, true ) ) {
$this->warning( 'VBR file with no VBR header. Bitrate values calculated from actual frame bitrates.' );
}
$recursivesearch = false;
$audio[ 'bitrate_mode' ] = 'cbr';
break;
}
// should be safe to leave this at 'vbr' and let it be overriden to 'cbr' if a CBR preset/mode is used by LAME
// if (substr($header, $VBRidOffset, strlen('Info')) == 'Xing') {
$audio[ 'bitrate_mode' ] = 'vbr';
$audio[ 'VBR_method' ] = 'Xing';
// } else {
// $ScanAsCBR = true;
// $audio['bitrate_mode'] = 'cbr';
// }
$audio[ 'xing_flags_raw' ] = getid3_lib::BigEndian2Int( substr( $header, $VBRidOffset + 4, 4 ) );
$audio[ 'xing_flags' ][ 'frames' ] = (bool) ( $audio[ 'xing_flags_raw' ] & 0x00000001 );
$audio[ 'xing_flags' ][ 'bytes' ] = (bool) ( $audio[ 'xing_flags_raw' ] & 0x00000002 );
$audio[ 'xing_flags' ][ 'toc' ] = (bool) ( $audio[ 'xing_flags_raw' ] & 0x00000004 );
$audio[ 'xing_flags' ][ 'vbr_scale' ] = (bool) ( $audio[ 'xing_flags_raw' ] & 0x00000008 );
if ( $audio[ 'xing_flags' ][ 'frames' ] ) {
$audio[ 'VBR_frames' ] = getid3_lib::BigEndian2Int( substr( $header, $VBRidOffset + 8, 4 ) );
//$audio['VBR_frames']--; // don't count header Xing/Info frame
}
if ( $audio[ 'xing_flags' ][ 'bytes' ] ) {
$audio[ 'VBR_bytes' ] = getid3_lib::BigEndian2Int( substr( $header, $VBRidOffset + 12, 4 ) );
}
//if (($audio['bitrate'] == 'free') && !empty($audio['VBR_frames']) && !empty($audio['VBR_bytes'])) {
//if (!empty($audio['VBR_frames']) && !empty($audio['VBR_bytes'])) {
if ( ! empty( $audio[ 'VBR_frames' ] ) ) {
$used_filesize = 0;
if ( ! empty( $audio[ 'VBR_bytes' ] ) ) {
$used_filesize = $audio[ 'VBR_bytes' ];
} elseif ( ! empty( $info[ 'filesize' ] ) ) {
$used_filesize = $info[ 'filesize' ];
$used_filesize -= ( isset( $info[ 'id3v2' ][ 'headerlength' ] ) ? intval( $info[ 'id3v2' ][ 'headerlength' ] ) : 0 );
$used_filesize -= ( isset( $info[ 'id3v1' ] ) ? 128 : 0 );
$used_filesize -= ( isset( $info[ 'tag_offset_end' ] ) ? $info[ 'tag_offset_end' ] - $info[ 'tag_offset_start' ] : 0 );
$this->warning( 'MP3.Xing header missing VBR_bytes, assuming MPEG audio portion of file is ' . number_format( $used_filesize ) . ' bytes' );
}
$framelengthfloat = $used_filesize / $audio[ 'VBR_frames' ];
if ( $audio[ 'layer' ] == '1' ) {
// BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
//$info['audio']['bitrate'] = ((($framelengthfloat / 4) - intval($audio['padding'])) * $audio['sample_rate']) / 12;
$info[ 'audio' ][ 'bitrate' ] = ( $framelengthfloat / 4 ) * $audio[ 'sample_rate' ] * ( 2 / $info[ 'audio' ][ 'channels' ] ) / 12;
} else {
// Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
//$info['audio']['bitrate'] = (($framelengthfloat - intval($audio['padding'])) * $audio['sample_rate']) / 144;
$info[ 'audio' ][ 'bitrate' ] = $framelengthfloat * $audio[ 'sample_rate' ] * ( 2 / $info[ 'audio' ][ 'channels' ] ) / 144;
}
$audio[ 'framelength' ] = floor( $framelengthfloat );
}
if ( $audio[ 'xing_flags' ][ 'toc' ] ) {
$LAMEtocData = substr( $header, $VBRidOffset + 16, 100 );
for ( $i = 0; $i < 100; $i ++ ) {
$audio[ 'toc' ][ $i ] = ord( $LAMEtocData[ $i ] );
}
}
if ( $audio[ 'xing_flags' ][ 'vbr_scale' ] ) {
$audio[ 'VBR_scale' ] = getid3_lib::BigEndian2Int( substr( $header, $VBRidOffset + 116, 4 ) );
}
// http://gabriel.mp3-tech.org/mp3infotag.html
if ( substr( $header, $VBRidOffset + 120, 4 ) == 'LAME' ) {
// shortcut
$audio[ 'LAME' ] = $this->getLAME($info, $audio, $header, $VBRidOffset);
}
} while ( false );
}
private function getLAME(array &$info, array &$audio, string $header, int $offset) {
$lame = &$audio[ 'LAME' ];
$lame[ 'long_version' ] = substr( $header, $offset + 120, 20 );
$lame[ 'short_version' ] = substr( $lame[ 'long_version' ], 0, 9 );
if ( $lame[ 'short_version' ] >= 'LAME3.90' ) {
// extra 11 chars are not part of version string when LAMEtag present
unset( $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 = $offset - 0x24;
// shortcuts
$lame[ 'RGAD' ] = array( 'track' => array(), 'album' => array() );
$RGAD = &$lame[ 'RGAD' ];
$RGAD_track = &$RGAD[ 'track' ];
$RGAD_album = &$RGAD[ 'album' ];
$lame[ 'raw' ] = array();
$lame_raw = &$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( $audio[ 'VBR_scale' ] );
$lame[ 'vbr_quality' ] = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0x9B, 1 ) );
// bytes $9C-$A4 Encoder short VersionString
$lame[ 'short_version' ] = substr( $header, $LAMEtagOffsetContant + 0x9C, 9 );
// byte $A5 Info Tag revision + VBR method
$LAMEtagRevisionVBRmethod = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0xA5, 1 ) );
$lame[ 'tag_revision' ] = ( $LAMEtagRevisionVBRmethod & 0xF0 ) >> 4;
$lame_raw[ 'vbr_method' ] = $LAMEtagRevisionVBRmethod & 0x0F;
$lame[ 'vbr_method' ] = self::LAMEvbrMethodLookup( $lame_raw[ 'vbr_method' ] );
$audio[ 'bitrate_mode' ] = substr( $lame[ 'vbr_method' ], 0, 3 ); // usually either 'cbr' or 'vbr', but truncates 'vbr-old / vbr-rh' to 'vbr'
// byte $A6 Lowpass filter value
$lame[ 'lowpass_frequency' ] = getid3_lib::BigEndian2Int( substr( $header, $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 ( $lame[ 'short_version' ] >= 'LAME3.94b' ) {
// LAME 3.94a16 and later - 9.23 fixed point
// ie 0x0059E2EE / (2^23) = 5890798 / 8388608 = 0.7022378444671630859375
$RGAD[ 'peak_amplitude' ] = (float) ( ( getid3_lib::BigEndian2Int( substr( $header, $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
$RGAD[ 'peak_amplitude' ] = getid3_lib::LittleEndian2Float( substr( $header, $LAMEtagOffsetContant + 0xA7, 4 ) );
}
if ( $RGAD[ 'peak_amplitude' ] == 0 ) {
unset( $RGAD[ 'peak_amplitude' ] );
} else {
$RGAD[ 'peak_db' ] = getid3_lib::RGADamplitude2dB( $RGAD[ 'peak_amplitude' ] );
}
$lame_raw[ 'RGAD_track' ] = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0xAB, 2 ) );
$lame_raw[ 'RGAD_album' ] = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0xAD, 2 ) );
if ( $lame_raw[ 'RGAD_track' ] != 0 ) {
$RGAD_track[ 'raw' ][ 'name' ] = ( $lame_raw[ 'RGAD_track' ] & 0xE000 ) >> 13;
$RGAD_track[ 'raw' ][ 'originator' ] = ( $lame_raw[ 'RGAD_track' ] & 0x1C00 ) >> 10;
$RGAD_track[ 'raw' ][ 'sign_bit' ] = ( $lame_raw[ 'RGAD_track' ] & 0x0200 ) >> 9;
$RGAD_track[ 'raw' ][ 'gain_adjust' ] = $lame_raw[ 'RGAD_track' ] & 0x01FF;
$RGAD_track[ 'name' ] = getid3_lib::RGADnameLookup( $RGAD_track[ 'raw' ][ 'name' ] );
$RGAD_track[ 'originator' ] = getid3_lib::RGADoriginatorLookup( $RGAD_track[ 'raw' ][ 'originator' ] );
$RGAD_track[ 'gain_db' ] = getid3_lib::RGADadjustmentLookup( $RGAD_track[ 'raw' ][ 'gain_adjust' ], $RGAD_track[ 'raw' ][ 'sign_bit' ] );
if ( ! empty( $RGAD[ 'peak_amplitude' ] ) ) {
$info[ 'replay_gain' ][ 'track' ][ 'peak' ] = $RGAD[ 'peak_amplitude' ];
}
$info[ 'replay_gain' ][ 'track' ][ 'originator' ] = $RGAD_track[ 'originator' ];
$info[ 'replay_gain' ][ 'track' ][ 'adjustment' ] = $RGAD_track[ 'gain_db' ];
} else {
unset( $RGAD[ 'track' ] );
}
if ( $lame_raw[ 'RGAD_album' ] != 0 ) {
$RGAD_album[ 'raw' ][ 'name' ] = ( $lame_raw[ 'RGAD_album' ] & 0xE000 ) >> 13;
$RGAD_album[ 'raw' ][ 'originator' ] = ( $lame_raw[ 'RGAD_album' ] & 0x1C00 ) >> 10;
$RGAD_album[ 'raw' ][ 'sign_bit' ] = ( $lame_raw[ 'RGAD_album' ] & 0x0200 ) >> 9;
$RGAD_album[ 'raw' ][ 'gain_adjust' ] = $lame_raw[ 'RGAD_album' ] & 0x01FF;
$RGAD_album[ 'name' ] = getid3_lib::RGADnameLookup( $RGAD_album[ 'raw' ][ 'name' ] );
$RGAD_album[ 'originator' ] = getid3_lib::RGADoriginatorLookup( $RGAD_album[ 'raw' ][ 'originator' ] );
$RGAD_album[ 'gain_db' ] = getid3_lib::RGADadjustmentLookup( $RGAD_album[ 'raw' ][ 'gain_adjust' ], $RGAD_album[ 'raw' ][ 'sign_bit' ] );
if ( ! empty( $RGAD[ 'peak_amplitude' ] ) ) {
$info[ 'replay_gain' ][ 'album' ][ 'peak' ] = $RGAD[ 'peak_amplitude' ];
}
$info[ 'replay_gain' ][ 'album' ][ 'originator' ] = $RGAD_album[ 'originator' ];
$info[ 'replay_gain' ][ 'album' ][ 'adjustment' ] = $RGAD_album[ 'gain_db' ];
} else {
unset( $RGAD[ 'album' ] );
}
if ( empty( $RGAD ) ) {
unset( $lame[ 'RGAD' ] );
}
// byte $AF Encoding flags + ATH Type
$EncodingFlagsATHtype = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0xAF, 1 ) );
$lame[ 'encoding_flags' ][ 'nspsytune' ] = (bool) ( $EncodingFlagsATHtype & 0x10 );
$lame[ 'encoding_flags' ][ 'nssafejoint' ] = (bool) ( $EncodingFlagsATHtype & 0x20 );
$lame[ 'encoding_flags' ][ 'nogap_next' ] = (bool) ( $EncodingFlagsATHtype & 0x40 );
$lame[ 'encoding_flags' ][ 'nogap_prev' ] = (bool) ( $EncodingFlagsATHtype & 0x80 );
$lame[ 'ath_type' ] = $EncodingFlagsATHtype & 0x0F;
// byte $B0 if ABR {specified bitrate} else {minimal bitrate}
$lame[ 'raw' ][ 'abrbitrate_minbitrate' ] = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0xB0, 1 ) );
if ( $lame_raw[ 'vbr_method' ] == 2 ) { // Average BitRate (ABR)
$lame[ 'bitrate_abr' ] = $lame[ 'raw' ][ 'abrbitrate_minbitrate' ];
} elseif ( $lame_raw[ 'vbr_method' ] == 1 ) { // Constant BitRate (CBR)
// ignore
} elseif ( $lame[ 'raw' ][ 'abrbitrate_minbitrate' ] > 0 ) { // Variable BitRate (VBR) - minimum bitrate
$lame[ 'bitrate_min' ] = $lame[ 'raw' ][ 'abrbitrate_minbitrate' ];
}
// bytes $B1-$B3 Encoder delays
$EncoderDelays = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0xB1, 3 ) );
$lame[ 'encoder_delay' ] = ( $EncoderDelays & 0xFFF000 ) >> 12;
$lame[ 'end_padding' ] = $EncoderDelays & 0x000FFF;
// byte $B4 Misc
$MiscByte = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0xB4, 1 ) );
$lame_raw[ 'noise_shaping' ] = ( $MiscByte & 0x03 );
$lame_raw[ 'stereo_mode' ] = ( $MiscByte & 0x1C ) >> 2;
$lame_raw[ 'not_optimal_quality' ] = ( $MiscByte & 0x20 ) >> 5;
$lame_raw[ 'source_sample_freq' ] = ( $MiscByte & 0xC0 ) >> 6;
$lame[ 'noise_shaping' ] = $lame_raw[ 'noise_shaping' ];
$lame[ 'stereo_mode' ] = self::LAMEmiscStereoModeLookup( $lame_raw[ 'stereo_mode' ] );
$lame[ 'not_optimal_quality' ] = (bool) $lame_raw[ 'not_optimal_quality' ];
$lame[ 'source_sample_freq' ] = self::LAMEmiscSourceSampleFrequencyLookup( $lame_raw[ 'source_sample_freq' ] );
// byte $B5 MP3 Gain
$lame_raw[ 'mp3_gain' ] = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0xB5, 1 ), false, true );
$lame[ 'mp3_gain_db' ] = ( getid3_lib::RGADamplitude2dB( 2 ) / 4 ) * $lame_raw[ 'mp3_gain' ];
$lame[ 'mp3_gain_factor' ] = pow( 2, ( $lame[ 'mp3_gain_db' ] / 6 ) );
// bytes $B6-$B7 Preset and surround info
$PresetSurroundBytes = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0xB6, 2 ) );
// Reserved = ($PresetSurroundBytes & 0xC000);
$lame_raw[ 'surround_info' ] = ( $PresetSurroundBytes & 0x3800 );
$lame[ 'surround_info' ] = self::LAMEsurroundInfoLookup( $lame_raw[ 'surround_info' ] );
$lame[ 'preset_used_id' ] = ( $PresetSurroundBytes & 0x07FF );
$lame[ 'preset_used' ] = self::LAMEpresetUsedLookup( $lame );
if ( ! empty( $lame[ 'preset_used_id' ] ) && empty( $lame[ 'preset_used' ] ) ) {
$this->warning( 'Unknown LAME preset used (' . $lame[ 'preset_used_id' ] . ') - please report to info@getid3.org' );
}
if ( ( $lame[ 'short_version' ] == 'LAME3.90.' ) && ! empty( $lame[ 'preset_used_id' ] ) ) {
// this may change if 3.90.4 ever comes out
$lame[ 'short_version' ] = 'LAME3.90.3';
}
// bytes $B8-$BB MusicLength
$lame[ 'audio_bytes' ] = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0xB8, 4 ) );
$ExpectedNumberOfAudioBytes = ( ( $lame[ 'audio_bytes' ] > 0 ) ? $lame[ 'audio_bytes' ] : $audio[ 'VBR_bytes' ] );
// bytes $BC-$BD MusicCRC
$lame[ 'music_crc' ] = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0xBC, 2 ) );
// bytes $BE-$BF CRC-16 of Info Tag
$lame[ 'lame_tag_crc' ] = getid3_lib::BigEndian2Int( substr( $header, $LAMEtagOffsetContant + 0xBE, 2 ) );
// LAME CBR
if ( $lame_raw[ 'vbr_method' ] == 1 ) {
$audio[ 'bitrate_mode' ] = 'cbr';
$audio[ 'bitrate' ] = self::ClosestStandardMP3Bitrate( $audio[ 'bitrate' ] );
$info[ 'audio' ][ 'bitrate' ] = $audio[ 'bitrate' ];
//if (empty($audio['bitrate']) || (!empty($lame['bitrate_min']) && ($lame['bitrate_min'] != 255))) {
// $audio['bitrate'] = $lame['bitrate_min'];
//}
}
}
return $lame;
}
/**
* @param int $offset
* @param array $info
* @param bool $recursivesearch
* @param bool $ScanAsCBR
* @param bool $FastMPEGheaderScan
*
* @return bool
* @throws getid3_exception
*/
public function decodeMPEGaudioHeader($offset, &$info, $recursivesearch=true, $ScanAsCBR=false, $FastMPEGheaderScan=false) {
do {
$result = false;
if (empty(self::$MPEGaudio)) {
self::$MPEGaudio = $this->getMPEGaudio();
}
if ($this->fseek($offset) != 0) {
$this->error('decodeMPEGaudioHeader() failed to seek to next offset at '.$offset);
break;
}
//$header = $this->fread(1441); // worst-case max length = 32kHz @ 320kbps layer 3 = 1441 bytes/frame
$header = $this->fread(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
$head4 = substr($header, 0, 4);
$head4_key = getid3_lib::PrintHexBytes($head4, true, false, false);
if (isset(self::$MPEGaudio['HeaderDecodeCache'][$head4_key])) {
$MPEGheaderRawArray = self::$MPEGaudio['HeaderDecodeCache'][$head4_key];
} else {
$MPEGheaderRawArray = self::MPEGaudioHeaderDecode($head4);
self::$MPEGaudio['HeaderDecodeCache'][$head4_key] = $MPEGheaderRawArray;
}
if (!isset(self::$MPEGaudio['HeaderValidCache'][$head4_key])) { // Not in cache
//self::$MPEGaudio['HeaderValidCache'][$head4_key] = self::MPEGaudioHeaderValid($MPEGheaderRawArray, false, true); // allow badly-formatted freeformat (from LAME 3.90 - 3.93.1)
self::$MPEGaudio['HeaderValidCache'][$head4_key] = self::MPEGaudioHeaderValid($MPEGheaderRawArray, false, false);
}
// shortcut
if (!isset($info['mpeg']['audio'])) {
$info['mpeg']['audio'] = array();
}
$audio = &$info['mpeg']['audio'];
if (!self::$MPEGaudio['HeaderValidCache'][$head4_key]) {
$this->error('Invalid MPEG audio header ('.getid3_lib::PrintHexBytes($head4).') at offset '.$offset);
break;
}
$audio['raw'] = $MPEGheaderRawArray;
if (!$FastMPEGheaderScan) {
$this->annotateHeader($audio, $header);
$info['audio']['channels'] = $audio['channels'];
$info['audio']['sample_rate'] = $audio['sample_rate'];
}
if ($audio['raw']['bitrate'] == 15) {
// http://www.hydrogenaudio.org/?act=ST&f=16&t=9682&st=0
$this->warning('Invalid bitrate index (15), this is a known bug in free-format MP3s encoded by LAME v3.90 - 3.93.1');
$audio['raw']['bitrate'] = 0;
}
$audio['padding'] = (bool) $audio['raw']['padding'];
$audio['bitrate'] = self::$MPEGaudio['BitrateLookup'][$audio['version']][$audio['layer']][$audio['raw']['bitrate']];
if (($audio['bitrate'] == 'free') && ($offset == $info['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 && ($audio['layer'] == '2')) {
$info['audio']['dataformat'] = 'mp2';
if ( ! $this->isValidBitrate($audio) ) {
break;
}
}
if ($info['audio']['sample_rate'] > 0) {
$audio['framelength'] = self::MPEGaudioFrameLength(
$audio['bitrate'],
$audio['version'],
$audio['layer'],
(int) $audio['padding'],
$info['audio']['sample_rate']
);
}
$nextframetestoffset = $offset + 1;
if ($audio['bitrate'] != 'free') {
$info['audio']['bitrate'] = $audio['bitrate'];
if (! isset($audio['framelength'])) {
$this->error('Frame at offset('.$offset.') is has an invalid frame length.');
break;
}
$nextframetestoffset = $offset + $audio['framelength'];
}
$ExpectedNumberOfAudioBytes = 0;
////////////////////////////////////////////////////////////////////////////////////
// Variable-bitrate headers
if (substr($header, 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
$info['audio']['codec'] = 'Fraunhofer';
$this->annotate_Fraunhofer_VBR($audio,$header,$offset);
$ExpectedNumberOfAudioBytes = $audio['VBR_bytes'];
} else {
$this->annnotate_Xing_VBR($audio,$header,$offset,$recursivesearch);
}
if (($ExpectedNumberOfAudioBytes > 0) && ($ExpectedNumberOfAudioBytes != ($info['avdataend'] - $info['avdataoffset']))) {
if ($ExpectedNumberOfAudioBytes > ($info['avdataend'] - $info['avdataoffset'])) {
if ($this->isDependencyFor('matroska') || $this->isDependencyFor('riff')) {
// ignore, audio data is broken into chunks so will always be data "missing"
}
elseif (($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])) == 1) {
$this->warning('Last byte of data truncated (this is a known bug in Meracl ID3 Tag Writer before v1.3.5)');
}
else {
$this->warning('Probable truncated file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, only found '.($info['avdataend'] - $info['avdataoffset']).' (short by '.($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])).' bytes)');
}
} else {
if ((($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes) == 1) {
// $prenullbytefileoffset = $this->ftell();
// $this->fseek($info['avdataend']);
// $PossibleNullByte = $this->fread(1);
// $this->fseek($prenullbytefileoffset);
// if ($PossibleNullByte === "\x00") {
$info['avdataend']--;
// $this->warning('Extra null byte at end of MP3 data assumed to be RIFF padding and therefore ignored');
// } else {
// $this->warning('Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']).' ('.(($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)');
// }
} else {
$this->warning('Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']).' ('.(($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)');
}
}
}
if (($audio['bitrate'] == 'free') && empty($info['audio']['bitrate'])) {
if (($offset == $info['avdataoffset']) && empty($audio['VBR_frames'])) {
$framebytelength = $this->FreeFormatFrameLength($offset, true);
if ($framebytelength > 0) {
$audio['framelength'] = $framebytelength;
if ($audio['layer'] == '1') {
// BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
$info['audio']['bitrate'] = ((($framebytelength / 4) - intval($audio['padding'])) * $audio['sample_rate']) / 12;
} else {
// Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
$info['audio']['bitrate'] = (($framebytelength - intval($audio['padding'])) * $audio['sample_rate']) / 144;
}
} else {
$this->error('Error calculating frame length of free-format MP3 without Xing/LAME header');
}
}
}
if (isset($audio['VBR_frames']) ? $audio['VBR_frames'] : '') {
switch ($audio['bitrate_mode']) {
case 'vbr':
case 'abr':
$bytes_per_frame = 1152;
if (($audio['version'] == '1') && ($audio['layer'] == 1)) {
$bytes_per_frame = 384;
} elseif ((($audio['version'] == '2') || ($audio['version'] == '2.5')) && ($audio['layer'] == 3)) {
$bytes_per_frame = 576;
}
$audio['VBR_bitrate'] = (isset($audio['VBR_bytes']) ? (($audio['VBR_bytes'] / $audio['VBR_frames']) * 8) * ($info['audio']['sample_rate'] / $bytes_per_frame) : 0);
if ($audio['VBR_bitrate'] > 0) {
$info['audio']['bitrate'] = $audio['VBR_bitrate'];
$audio['bitrate'] = $audio['VBR_bitrate']; // to avoid confusion
}
break;
}
}
// End variable-bitrate headers
////////////////////////////////////////////////////////////////////////////////////
if ($recursivesearch) {
if (!$this->RecursiveFrameScanning($offset, $nextframetestoffset, $ScanAsCBR)) {
return false;
}
}
$result = true;
} while ( false );
return $result;
}
/**
* @param int $offset
* @param int $nextframetestoffset
* @param bool $ScanAsCBR
*
* @return bool
*/
public function RecursiveFrameScanning(&$offset, &$nextframetestoffset, $ScanAsCBR) {
$info = &$this->getid3->info;
$firstframetestarray = array('error' => array(), 'warning'=> array(), 'avdataend' => $info['avdataend'], 'avdataoffset' => $info['avdataoffset']);
$this->decodeMPEGaudioHeader($offset, $firstframetestarray, false);
for ($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) >= $info['avdataend']) {
// end of file
return true;
}
$nextframetestarray = array('error' => array(), 'warning' => array(), 'avdataend' => $info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
if ($this->decodeMPEGaudioHeader($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($nextframetestarray['mpeg']['audio']['bitrate']) || !isset($firstframetestarray['mpeg']['audio']['bitrate']) || ($nextframetestarray['mpeg']['audio']['bitrate'] != $firstframetestarray['mpeg']['audio']['bitrate'])) {
return false;
}
}
// next frame is OK, get ready to check the one after that
if (isset($nextframetestarray['mpeg']['audio']['framelength']) && ($nextframetestarray['mpeg']['audio']['framelength'] > 0)) {
$nextframetestoffset += $nextframetestarray['mpeg']['audio']['framelength'];
} else {
$this->error('Frame at offset ('.$offset.') is has an invalid frame length.');
return false;
}
} elseif (!empty($firstframetestarray['mpeg']['audio']['framelength']) && (($nextframetestoffset + $firstframetestarray['mpeg']['audio']['framelength']) > $info['avdataend'])) {
// it's not the end of the file, but there's not enough data left for another frame, so assume it's garbage/padding and return OK
return true;
} else {
// next frame is not valid, note the error and fail, so scanning can contiue for a valid frame sequence
$this->warning('Frame at offset ('.$offset.') is valid, but the next one at ('.$nextframetestoffset.') is not.');
return false;
}
}
return true;
}
/**
* @param int $offset
* @param bool $deepscan
*
* @return int|false
*/
public function FreeFormatFrameLength($offset, $deepscan=false) {
$info = &$this->getid3->info;
$this->fseek($offset);
$MPEGaudioData = $this->fread(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) {
$this->error('Cannot find next free-format synch pattern ('.getid3_lib::PrintHexBytes($SyncPattern1).' or '.getid3_lib::PrintHexBytes($SyncPattern2).') after offset '.$offset);
return false;
} else {
$this->warning('ModeExtension varies between first frame and other frames (known free-format issue in LAME 3.88)');
$info['audio']['codec'] = 'LAME';
$info['audio']['encoder'] = 'LAME3.88';
$SyncPattern1 = substr($SyncPattern1, 0, 3);
$SyncPattern2 = substr($SyncPattern2, 0, 3);
}
}
if ($deepscan) {
$ActualFrameLengthValues = array();
$nextoffset = $offset + $framelength;
while ($nextoffset < ($info['avdataend'] - 6)) {
$this->fseek($nextoffset - 1);
$NextSyncPattern = $this->fread(6);
if ((substr($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 {
$this->error('Did not find expected free-format sync pattern at offset '.$nextoffset);
return false;
}
$nextoffset += $framelength;
}
if (count($ActualFrameLengthValues) > 0) {
$framelength = intval(round(array_sum($ActualFrameLengthValues) / count($ActualFrameLengthValues)));
}
}
return $framelength;
}
/**
* @return bool
*/
public function getOnlyMPEGaudioInfoBruteForce() {
$MPEGaudioHeaderDecodeCache = array();
$MPEGaudioHeaderValidCache = array();
$MPEGaudioHeaderLengthCache = array();
$MPEGaudioVersionLookup = self::MPEGaudioVersionArray();
$MPEGaudioLayerLookup = self::MPEGaudioLayerArray();
$MPEGaudioBitrateLookup = self::MPEGaudioBitrateArray();
$MPEGaudioFrequencyLookup = self::MPEGaudioFrequencyArray();
$MPEGaudioChannelModeLookup = self::MPEGaudioChannelModeArray();
$MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
$MPEGaudioEmphasisLookup = self::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();
$info = &$this->getid3->info;
$this->fseek($info['avdataoffset']);
$max_frames_scan = 5000;
$frames_scanned = 0;
$previousvalidframe = $info['avdataoffset'];
while ($this->ftell() < $info['avdataend']) {
set_time_limit(30);
$head4 = $this->fread(4);
if (strlen($head4) < 4) {
break;
}
if ($head4[0] != "\xFF") {
for ($i = 1; $i < 4; $i++) {
if ($head4[$i] == "\xFF") {
$this->fseek($i - 4, SEEK_CUR);
continue 2;
}
}
continue;
}
if (!isset($MPEGaudioHeaderDecodeCache[$head4])) {
$MPEGaudioHeaderDecodeCache[$head4] = self::MPEGaudioHeaderDecode($head4);
}
if (!isset($MPEGaudioHeaderValidCache[$head4])) {
$MPEGaudioHeaderValidCache[$head4] = self::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] = self::MPEGaudioFrameLength(
$LongMPEGbitrateLookup[$head4],
$LongMPEGversionLookup[$head4],
$LongMPEGlayerLookup[$head4],
$LongMPEGpaddingLookup[$head4],
$LongMPEGfrequencyLookup[$head4]);
}
if ($MPEGaudioHeaderLengthCache[$head4] > 4) {
$WhereWeWere = $this->ftell();
$this->fseek($MPEGaudioHeaderLengthCache[$head4] - 4, SEEK_CUR);
$next4 = $this->fread(4);
if ($next4[0] == "\xFF") {
if (!isset($MPEGaudioHeaderDecodeCache[$next4])) {
$MPEGaudioHeaderDecodeCache[$next4] = self::MPEGaudioHeaderDecode($next4);
}
if (!isset($MPEGaudioHeaderValidCache[$next4])) {
$MPEGaudioHeaderValidCache[$next4] = self::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$next4], false, false);
}
if ($MPEGaudioHeaderValidCache[$next4]) {
$this->fseek(-4, SEEK_CUR);
getid3_lib::safe_inc($Distribution['bitrate'][$LongMPEGbitrateLookup[$head4]]);
getid3_lib::safe_inc($Distribution['layer'][$LongMPEGlayerLookup[$head4]]);
getid3_lib::safe_inc($Distribution['version'][$LongMPEGversionLookup[$head4]]);
getid3_lib::safe_inc($Distribution['padding'][intval($LongMPEGpaddingLookup[$head4])]);
getid3_lib::safe_inc($Distribution['frequency'][$LongMPEGfrequencyLookup[$head4]]);
if ($max_frames_scan && (++$frames_scanned >= $max_frames_scan)) {
$pct_data_scanned = ($this->ftell() - $info['avdataoffset']) / ($info['avdataend'] - $info['avdataoffset']);
$this->warning('too many MPEG audio frames to scan, only scanned first '.$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);
$this->fseek($WhereWeWere - 3);
}
}
}
foreach ($Distribution as $key => $value) {
ksort($Distribution[$key], SORT_NUMERIC);
}
ksort($Distribution['version'], SORT_STRING);
$info['mpeg']['audio']['bitrate_distribution'] = $Distribution['bitrate'];
$info['mpeg']['audio']['frequency_distribution'] = $Distribution['frequency'];
$info['mpeg']['audio']['layer_distribution'] = $Distribution['layer'];
$info['mpeg']['audio']['version_distribution'] = $Distribution['version'];
$info['mpeg']['audio']['padding_distribution'] = $Distribution['padding'];
if (count($Distribution['version']) > 1) {
$this->error('Corrupt file - more than one MPEG version detected');
}
if (count($Distribution['layer']) > 1) {
$this->error('Corrupt file - more than one MPEG layer detected');
}
if (count($Distribution['frequency']) > 1) {
$this->error('Corrupt file - more than one MPEG sample rate detected');
}
$bittotal = 0;
foreach ($Distribution['bitrate'] as $bitratevalue => $bitratecount) {
if ($bitratevalue != 'free') {
$bittotal += ($bitratevalue * $bitratecount);
}
}
$info['mpeg']['audio']['frame_count'] = array_sum($Distribution['bitrate']);
if ($info['mpeg']['audio']['frame_count'] == 0) {
$this->error('no MPEG audio frames found');
return false;
}
$info['mpeg']['audio']['bitrate'] = ($bittotal / $info['mpeg']['audio']['frame_count']);
$info['mpeg']['audio']['bitrate_mode'] = ((count($Distribution['bitrate']) > 0) ? 'vbr' : 'cbr');
$info['mpeg']['audio']['sample_rate'] = getid3_lib::array_max($Distribution['frequency'], true);
$info['audio']['bitrate'] = $info['mpeg']['audio']['bitrate'];
$info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
$info['audio']['sample_rate'] = $info['mpeg']['audio']['sample_rate'];
$info['audio']['dataformat'] = 'mp'.getid3_lib::array_max($Distribution['layer'], true);
$info['fileformat'] = $info['audio']['dataformat'];
return true;
}
/**
* @param int $avdataoffset
* @param bool $BitrateHistogram
*
* @return bool
*/
public function getOnlyMPEGaudioInfo($avdataoffset, $BitrateHistogram=false) {
// looks for synch, decodes MPEG audio header
$info = &$this->getid3->info;
static $MPEGaudioVersionLookup;
static $MPEGaudioLayerLookup;
static $MPEGaudioBitrateLookup;
if (empty($MPEGaudioVersionLookup)) {
$MPEGaudioVersionLookup = self::MPEGaudioVersionArray();
$MPEGaudioLayerLookup = self::MPEGaudioLayerArray();
$MPEGaudioBitrateLookup = self::MPEGaudioBitrateArray();
}
$this->fseek($avdataoffset);
$sync_seek_buffer_size = min(128 * 1024, $info['avdataend'] - $avdataoffset);
if ($sync_seek_buffer_size <= 0) {
$this->error('Invalid $sync_seek_buffer_size at offset '.$avdataoffset);
return false;
}
$header = $this->fread($sync_seek_buffer_size);
$sync_seek_buffer_size = strlen($header);
$SynchSeekOffset = 0;
while ($SynchSeekOffset < $sync_seek_buffer_size) {
if ((($avdataoffset + $SynchSeekOffset) < $info['avdataend']) && !feof($this->getid3->fp)) {
if ($SynchSeekOffset > $sync_seek_buffer_size) {
// if a synch's not found within the first 128k bytes, then give up
$this->error('Could not find valid MPEG audio synch within the first '.round($sync_seek_buffer_size / 1024).'kB');
if (isset($info['audio']['bitrate'])) {
unset($info['audio']['bitrate']);
}
if (isset($info['mpeg']['audio'])) {
unset($info['mpeg']['audio']);
}
if (empty($info['mpeg'])) {
unset($info['mpeg']);
}
return false;
} elseif (feof($this->getid3->fp)) {
$this->error('Could not find valid MPEG audio synch before end of file');
if (isset($info['audio']['bitrate'])) {
unset($info['audio']['bitrate']);
}
if (isset($info['mpeg']['audio'])) {
unset($info['mpeg']['audio']);
}
if (isset($info['mpeg']) && (!is_array($info['mpeg']) || (count($info['mpeg']) == 0))) {
unset($info['mpeg']);
}
return false;
}
}
if (($SynchSeekOffset + 1) >= strlen($header)) {
$this->error('Could not find valid MPEG synch before end of file');
return false;
}
if (($header[$SynchSeekOffset] == "\xFF") && ($header[($SynchSeekOffset + 1)] > "\xE0")) { // synch detected
$FirstFrameAVDataOffset = null;
if (!isset($FirstFrameThisfileInfo) && !isset($info['mpeg']['audio'])) {
$FirstFrameThisfileInfo = $info;
$FirstFrameAVDataOffset = $avdataoffset + $SynchSeekOffset;
if (!$this->decodeMPEGaudioHeader($FirstFrameAVDataOffset, $FirstFrameThisfileInfo, false)) {
// if this is the first valid MPEG-audio frame, save it in case it's a VBR header frame and there's
// garbage between this frame and a valid sequence of MPEG-audio frames, to be restored below
unset($FirstFrameThisfileInfo);
}
}
$dummy = $info; // only overwrite real data if valid header found
if ($this->decodeMPEGaudioHeader($avdataoffset + $SynchSeekOffset, $dummy, true)) {
$info = $dummy;
$info['avdataoffset'] = $avdataoffset + $SynchSeekOffset;
switch (isset($info['fileformat']) ? $info['fileformat'] : '') {
case '':
case 'id3':
case 'ape':
case 'mp3':
$info['fileformat'] = 'mp3';
$info['audio']['dataformat'] = 'mp3';
break;
}
if (isset($FirstFrameThisfileInfo) && isset($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode']) && ($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode'] == 'vbr')) {
if (!(abs($info['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.
$info = $FirstFrameThisfileInfo;
$info['avdataoffset'] = $FirstFrameAVDataOffset;
$info['fileformat'] = 'mp3';
$info['audio']['dataformat'] = 'mp3';
$dummy = $info;
unset($dummy['mpeg']['audio']);
$GarbageOffsetStart = $FirstFrameAVDataOffset + $FirstFrameThisfileInfo['mpeg']['audio']['framelength'];
$GarbageOffsetEnd = $avdataoffset + $SynchSeekOffset;
if ($this->decodeMPEGaudioHeader($GarbageOffsetEnd, $dummy, true, true)) {
$info = $dummy;
$info['avdataoffset'] = $GarbageOffsetEnd;
$this->warning('apparently-valid VBR header not used because could not find '.GETID3_MP3_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.'), but did find valid CBR stream starting at '.$GarbageOffsetEnd);
} else {
$this->warning('using data from VBR header even though could not find '.GETID3_MP3_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.')');
}
}
}
if (isset($info['mpeg']['audio']['bitrate_mode']) && ($info['mpeg']['audio']['bitrate_mode'] == 'vbr') && !isset($info['mpeg']['audio']['VBR_method'])) {
// VBR file with no VBR header
$BitrateHistogram = true;
}
if ($BitrateHistogram) {
$info['mpeg']['audio']['stereo_distribution'] = array('stereo'=>0, 'joint stereo'=>0, 'dual channel'=>0, 'mono'=>0);
$info['mpeg']['audio']['version_distribution'] = array('1'=>0, '2'=>0, '2.5'=>0);
if ($info['mpeg']['audio']['version'] == '1') {
if ($info['mpeg']['audio']['layer'] == 3) {
$info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 40000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 320000=>0);
} elseif ($info['mpeg']['audio']['layer'] == 2) {
$info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 320000=>0, 384000=>0);
} elseif ($info['mpeg']['audio']['layer'] == 1) {
$info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 64000=>0, 96000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 288000=>0, 320000=>0, 352000=>0, 384000=>0, 416000=>0, 448000=>0);
}
} elseif ($info['mpeg']['audio']['layer'] == 1) {
$info['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 {
$info['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);
}
$dummy = array('error'=>$info['error'], 'warning'=>$info['warning'], 'avdataend'=>$info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
$synchstartoffset = $info['avdataoffset'];
$this->fseek($info['avdataoffset']);
// 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++) {
$frames_scanned_this_segment = 0;
if ($this->ftell() >= $info['avdataend']) {
break;
}
$scan_start_offset[$current_segment] = max($this->ftell(), $info['avdataoffset'] + round($current_segment * (($info['avdataend'] - $info['avdataoffset']) / $max_scan_segments)));
if ($current_segment > 0) {
$this->fseek($scan_start_offset[$current_segment]);
$buffer_4k = $this->fread(4096);
for ($j = 0; $j < (strlen($buffer_4k) - 4); $j++) {
if (($buffer_4k[$j] == "\xFF") && ($buffer_4k[($j + 1)] > "\xE0")) { // synch detected
if ($this->decodeMPEGaudioHeader($scan_start_offset[$current_segment] + $j, $dummy, false, false, $FastMode)) {
$calculated_next_offset = $scan_start_offset[$current_segment] + $j + $dummy['mpeg']['audio']['framelength'];
if ($this->decodeMPEGaudioHeader($calculated_next_offset, $dummy, false, false, $FastMode)) {
$scan_start_offset[$current_segment] += $j;
break;
}
}
}
}
}
$synchstartoffset = $scan_start_offset[$current_segment];
while (($synchstartoffset < $info['avdataend']) && $this->decodeMPEGaudioHeader($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++;
$synchstartoffset++;
} else {
getid3_lib::safe_inc($info['mpeg']['audio']['bitrate_distribution'][$thisframebitrate]);
getid3_lib::safe_inc($info['mpeg']['audio']['stereo_distribution'][$dummy['mpeg']['audio']['channelmode']]);
getid3_lib::safe_inc($info['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)) {
$this_pct_scanned = ($this->ftell() - $scan_start_offset[$current_segment]) / ($info['avdataend'] - $info['avdataoffset']);
if (($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 += $this_pct_scanned;
break;
}
}
}
}
if ($pct_data_scanned > 0) {
$this->warning('too many MPEG audio frames to scan, only scanned '.$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 ($info['mpeg']['audio'] as $key1 => $value1) {
if (!preg_match('#_distribution$#i', $key1)) {
continue;
}
foreach ($value1 as $key2 => $value2) {
$info['mpeg']['audio'][$key1][$key2] = round($value2 / $pct_data_scanned);
}
}
}
if ($SynchErrorsFound > 0) {
$this->warning('Found '.$SynchErrorsFound.' synch errors in histogram analysis');
//return false;
}
$bittotal = 0;
$framecounter = 0;
foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitratevalue => $bitratecount) {
$framecounter += $bitratecount;
if ($bitratevalue != 'free') {
$bittotal += ($bitratevalue * $bitratecount);
}
}
if ($framecounter == 0) {
$this->error('Corrupt MP3 file: framecounter == zero');
return false;
}
$info['mpeg']['audio']['frame_count'] = getid3_lib::CastAsInt($framecounter);
$info['mpeg']['audio']['bitrate'] = ($bittotal / $framecounter);
$info['audio']['bitrate'] = $info['mpeg']['audio']['bitrate'];
// Definitively set VBR vs CBR, even if the Xing/LAME/VBRI header says differently
$distinct_bitrates = 0;
foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitrate_value => $bitrate_count) {
if ($bitrate_count > 0) {
$distinct_bitrates++;
}
}
if ($distinct_bitrates > 1) {
$info['mpeg']['audio']['bitrate_mode'] = 'vbr';
} else {
$info['mpeg']['audio']['bitrate_mode'] = 'cbr';
}
$info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
}
break; // exit while()
}
}
$SynchSeekOffset++;
if (($avdataoffset + $SynchSeekOffset) >= $info['avdataend']) {
// end of file/data
if (empty($info['mpeg']['audio'])) {
$this->error('could not find valid MPEG synch before end of file');
if (isset($info['audio']['bitrate'])) {
unset($info['audio']['bitrate']);
}
if (isset($info['mpeg']['audio'])) {
unset($info['mpeg']['audio']);
}
if (isset($info['mpeg']) && (!is_array($info['mpeg']) || empty($info['mpeg']))) {
unset($info['mpeg']);
}
return false;
}
break;
}
}
$info['audio']['channels'] = $info['mpeg']['audio']['channels'];
$info['audio']['channelmode'] = $info['mpeg']['audio']['channelmode'];
$info['audio']['sample_rate'] = $info['mpeg']['audio']['sample_rate'];
return true;
}
/**
* @return array
*/
public static function MPEGaudioVersionArray() {
static $MPEGaudioVersion = array('2.5', false, '2', '1');
return $MPEGaudioVersion;
}
/**
* @return array
*/
public static function MPEGaudioLayerArray() {
static $MPEGaudioLayer = array(false, 3, 2, 1);
return $MPEGaudioLayer;
}
/**
* @return array
*/
public static 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;
}
/**
* @return array
*/
public static 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;
}
/**
* @return array
*/
public static function MPEGaudioChannelModeArray() {
static $MPEGaudioChannelMode = array('stereo', 'joint stereo', 'dual channel', 'mono');
return $MPEGaudioChannelMode;
}
/**
* @return array
*/
public static 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;
}
/**
* @return array
*/
public static function MPEGaudioEmphasisArray() {
static $MPEGaudioEmphasis = array('none', '50/15ms', false, 'CCIT J.17');
return $MPEGaudioEmphasis;
}
/**
* @param string $head4
* @param bool $allowBitrate15
*
* @return bool
*/
public static function MPEGaudioHeaderBytesValid($head4, $allowBitrate15=false) {
return self::MPEGaudioHeaderValid(self::MPEGaudioHeaderDecode($head4), false, $allowBitrate15);
}
/**
* @param array $rawarray
* @param bool $echoerrors
* @param bool $allowBitrate15
*
* @return bool
*/
public static function MPEGaudioHeaderValid($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 = self::MPEGaudioVersionArray();
$MPEGaudioLayerLookup = self::MPEGaudioLayerArray();
$MPEGaudioBitrateLookup = self::MPEGaudioBitrateArray();
$MPEGaudioFrequencyLookup = self::MPEGaudioFrequencyArray();
$MPEGaudioChannelModeLookup = self::MPEGaudioChannelModeArray();
$MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
$MPEGaudioEmphasisLookup = self::MPEGaudioEmphasisArray();
}
if (isset($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;
}
/**
* @param string $Header4Bytes
*
* @return array|false
*/
public static function MPEGaudioHeaderDecode($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;
}
/**
* @param int|string $bitrate
* @param string $version
* @param string $layer
* @param bool $padding
* @param int $samplerate
*
* @return int|false
*/
public static function MPEGaudioFrameLength(&$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];
}
/**
* @param float|int $bit_rate
*
* @return int|float|string
*/
public static function ClosestStandardMP3Bitrate($bit_rate) {
static $standard_bit_rates = array (320000, 256000, 224000, 192000, 160000, 128000, 112000, 96000, 80000, 64000, 56000, 48000, 40000, 32000, 24000, 16000, 8000);
static $bit_rate_table = array (0=>'-');
$round_bit_rate = intval(round($bit_rate, -3));
if (!isset($bit_rate_table[$round_bit_rate])) {
if ($round_bit_rate > max($standard_bit_rates)) {
$bit_rate_table[$round_bit_rate] = round($bit_rate, 2 - strlen($bit_rate));
} else {
$bit_rate_table[$round_bit_rate] = max($standard_bit_rates);
foreach ($standard_bit_rates as $standard_bit_rate) {
if ($round_bit_rate >= $standard_bit_rate + (($bit_rate_table[$round_bit_rate] - $standard_bit_rate) / 2)) {
break;
}
$bit_rate_table[$round_bit_rate] = $standard_bit_rate;
}
}
}
return $bit_rate_table[$round_bit_rate];
}
/**
* @param string $version
* @param string $channelmode
*
* @return int
*/
public static function XingVBRidOffset($version, $channelmode) {
static $XingVBRidOffsetCache = array();
if (empty($XingVBRidOffsetCache)) {
$XingVBRidOffsetCache = 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 $XingVBRidOffsetCache[$version][$channelmode];
}
/**
* @param int $VBRmethodID
*
* @return string
*/
public static function LAMEvbrMethodLookup($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] : '');
}
/**
* @param int $StereoModeID
*
* @return string
*/
public static function LAMEmiscStereoModeLookup($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] : '');
}
/**
* @param int $SourceSampleFrequencyID
*
* @return string
*/
public static function LAMEmiscSourceSampleFrequencyLookup($SourceSampleFrequencyID) {
static $LAMEmiscSourceSampleFrequencyLookup = array(
0 => '<= 32 kHz',
1 => '44.1 kHz',
2 => '48 kHz',
3 => '> 48kHz'
);
return (isset($LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID]) ? $LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID] : '');
}
/**
* @param int $SurroundInfoID
*
* @return string
*/
public static function LAMEsurroundInfoLookup($SurroundInfoID) {
static $LAMEsurroundInfoLookup = array(
0 => 'no surround info',
1 => 'DPL encoding',
2 => 'DPL2 encoding',
3 => 'Ambisonic encoding'
);
return (isset($LAMEsurroundInfoLookup[$SurroundInfoID]) ? $LAMEsurroundInfoLookup[$SurroundInfoID] : 'reserved');
}
/**
* @param array $LAMEtag
*
* @return string
*/
public static function LAMEpresetUsedLookup($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');
}
}
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