<?php
/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org> //
// available at http://getid3.sourceforge.net ///
// or http://www.getid3.org ///
/////////////////////////////////////////////////////////////////
// //
// getid3.mp3.php - part of getID3() //
// See getid3.readme.txt for more details //
// //
/////////////////////////////////////////////////////////////////
// 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('MPEG_VALID_CHECK_FRAMES', 35);
function getMP3headerFilepointer(&$fd, &$ThisFileInfo) {
getOnlyMPEGaudioInfo($fd, $ThisFileInfo, $ThisFileInfo['avdataoffset']);
if (isset($ThisFileInfo['mpeg']['audio']['bitrate_mode'])) {
$ThisFileInfo['audio']['bitrate_mode'] = strtolower($ThisFileInfo['mpeg']['audio']['bitrate_mode']);
}
if (((isset($ThisFileInfo['id3v2']) && ($ThisFileInfo['avdataoffset'] > $ThisFileInfo['id3v2']['headerlength'])) || (!isset($ThisFileInfo['id3v2']) && ($ThisFileInfo['avdataoffset'] > 0)))) {
$ThisFileInfo['warning'] .= "\n".'Unknown data before synch ';
if (isset($ThisFileInfo['id3v2']['headerlength'])) {
$ThisFileInfo['warning'] .= '(ID3v2 header ends at '.$ThisFileInfo['id3v2']['headerlength'].', then '.($ThisFileInfo['avdataoffset'] - $ThisFileInfo['id3v2']['headerlength']).' bytes garbage, ';
} else {
$ThisFileInfo['warning'] .= '(should be at beginning of file, ';
}
$ThisFileInfo['warning'] .= 'synch detected at '.$ThisFileInfo['avdataoffset'].')';
if ($ThisFileInfo['audio']['bitrate_mode'] == 'cbr') {
if (!empty($ThisFileInfo['id3v2']['headerlength']) && (($ThisFileInfo['avdataoffset'] - $ThisFileInfo['id3v2']['headerlength']) == $ThisFileInfo['mpeg']['audio']['framelength'])) {
$ThisFileInfo['warning'] .= '. This is a known problem with some versions of LAME (3.91, 3.92) DLL in CBR mode.';
$ThisFileInfo['audio']['codec'] = 'LAME';
} elseif (empty($ThisFileInfo['id3v2']['headerlength']) && ($ThisFileInfo['avdataoffset'] == $ThisFileInfo['mpeg']['audio']['framelength'])) {
$ThisFileInfo['warning'] .= '. This is a known problem with some versions of LAME (3.91, 3.92) DLL in CBR mode.';
$ThisFileInfo['audio']['codec'] = 'LAME';
}
}
}
if (isset($ThisFileInfo['mpeg']['audio']['layer']) && ($ThisFileInfo['mpeg']['audio']['layer'] == 'II')) {
$ThisFileInfo['audio']['dataformat'] = 'mp2';
} elseif (isset($ThisFileInfo['mpeg']['audio']['layer']) && ($ThisFileInfo['mpeg']['audio']['layer'] == 'I')) {
$ThisFileInfo['audio']['dataformat'] = 'mp1';
}
if ($ThisFileInfo['fileformat'] == 'mp3') {
switch ($ThisFileInfo['audio']['dataformat']) {
case 'mp1':
case 'mp2':
case 'mp3':
$ThisFileInfo['fileformat'] = $ThisFileInfo['audio']['dataformat'];
break;
default:
$ThisFileInfo['warning'] .= "\n".'Expecting [audio][dataformat] to be mp1/mp2/mp3 when fileformat == mp3, [audio][dataformat] actually "'.$ThisFileInfo['audio']['dataformat'].'"';
break;
}
}
if (empty($ThisFileInfo['fileformat'])) {
$ThisFileInfo['error'] .= "\n".'Synch not found';
unset($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 / $ThisFileInfo['audio']['bitrate'];
}
if (isset($ThisFileInfo['mpeg']['audio']['LAME'])) {
$ThisFileInfo['audio']['codec'] = 'LAME';
if (!empty($ThisFileInfo['mpeg']['audio']['LAME']['long_version'])) {
$ThisFileInfo['audio']['encoder'] = trim($ThisFileInfo['mpeg']['audio']['LAME']['long_version']);
}
}
return true;
}
function decodeMPEGaudioHeader($fd, $offset, &$ThisFileInfo, $recursivesearch=true, $ScanAsCBR=false, $FastMPEGheaderScan=false, $allowBitrateMode15=false) {
static $MPEGaudioVersionLookup;
static $MPEGaudioLayerLookup;
static $MPEGaudioBitrateLookup;
static $MPEGaudioFrequencyLookup;
static $MPEGaudioChannelModeLookup;
static $MPEGaudioModeExtensionLookup;
static $MPEGaudioEmphasisLookup;
if (empty($MPEGaudioVersionLookup)) {
$MPEGaudioVersionLookup = MPEGaudioVersionArray();
$MPEGaudioLayerLookup = MPEGaudioLayerArray();
$MPEGaudioBitrateLookup = MPEGaudioBitrateArray();
$MPEGaudioFrequencyLookup = MPEGaudioFrequencyArray();
$MPEGaudioChannelModeLookup = MPEGaudioChannelModeArray();
$MPEGaudioModeExtensionLookup = MPEGaudioModeExtensionArray();
$MPEGaudioEmphasisLookup = MPEGaudioEmphasisArray();
}
if ($offset >= $ThisFileInfo['avdataend']) {
$ThisFileInfo['error'] .= "\n".'end of file encounter looking for MPEG synch';
return false;
}
fseek($fd, $offset, SEEK_SET);
$headerstring = fread($fd, 1441); // worse-case max length = 32kHz @ 320kbps layer 3 = 1441 bytes/frame
// 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 {
$MPEGheaderRawArray = MPEGaudioHeaderDecode($head4);
$MPEGaudioHeaderDecodeCache[$head4] = $MPEGheaderRawArray;
}
static $MPEGaudioHeaderValidCache = array();
// Not in cache
if (!isset($MPEGaudioHeaderValidCache[$head4])) {
$MPEGaudioHeaderValidCache[$head4] = MPEGaudioHeaderValid($MPEGheaderRawArray);
}
if ($MPEGaudioHeaderValidCache[$head4]) {
$ThisFileInfo['mpeg']['audio']['raw'] = $MPEGheaderRawArray;
} else {
$ThisFileInfo['error'] .= "\n".'Invalid MPEG audio header at offset '.$offset;
return false;
}
if (!$FastMPEGheaderScan) {
$ThisFileInfo['mpeg']['audio']['version'] = $MPEGaudioVersionLookup[$ThisFileInfo['mpeg']['audio']['raw']['version']];
$ThisFileInfo['mpeg']['audio']['layer'] = $MPEGaudioLayerLookup[$ThisFileInfo['mpeg']['audio']['raw']['layer']];
$ThisFileInfo['mpeg']['audio']['channelmode'] = $MPEGaudioChannelModeLookup[$ThisFileInfo['mpeg']['audio']['raw']['channelmode']];
$ThisFileInfo['mpeg']['audio']['channels'] = (($ThisFileInfo['mpeg']['audio']['channelmode'] == 'mono') ? 1 : 2);
$ThisFileInfo['mpeg']['audio']['sample_rate'] = $MPEGaudioFrequencyLookup[$ThisFileInfo['mpeg']['audio']['version']][$ThisFileInfo['mpeg']['audio']['raw']['sample_rate']];
$ThisFileInfo['mpeg']['audio']['protection'] = !$ThisFileInfo['mpeg']['audio']['raw']['protection'];
$ThisFileInfo['mpeg']['audio']['private'] = (bool) $ThisFileInfo['mpeg']['audio']['raw']['private'];
$ThisFileInfo['mpeg']['audio']['modeextension'] = $MPEGaudioModeExtensionLookup[$ThisFileInfo['mpeg']['audio']['layer']][$ThisFileInfo['mpeg']['audio']['raw']['modeextension']];
$ThisFileInfo['mpeg']['audio']['copyright'] = (bool) $ThisFileInfo['mpeg']['audio']['raw']['copyright'];
$ThisFileInfo['mpeg']['audio']['original'] = (bool) $ThisFileInfo['mpeg']['audio']['raw']['original'];
$ThisFileInfo['mpeg']['audio']['emphasis'] = $MPEGaudioEmphasisLookup[$ThisFileInfo['mpeg']['audio']['raw']['emphasis']];
$ThisFileInfo['audio']['channels'] = $ThisFileInfo['mpeg']['audio']['channels'];
$ThisFileInfo['audio']['sample_rate'] = $ThisFileInfo['mpeg']['audio']['sample_rate'];
if ($ThisFileInfo['mpeg']['audio']['protection']) {
$ThisFileInfo['mpeg']['audio']['crc'] = BigEndian2Int(substr($headerstring, 4, 2));
}
}
if ($ThisFileInfo['mpeg']['audio']['raw']['bitrate'] == 15) {
// http://www.hydrogenaudio.org/?act=ST&f=16&t=9682&st=0
$ThisFileInfo['warning'] .= "\n".'Invalid bitrate index (15), this is a known bug in free-format MP3s encoded by LAME v3.90 - 3.93.1';
if ($allowBitrateMode15) {
$ThisFileInfo['mpeg']['audio']['raw']['bitrate'] = 0;
} else {
return false;
}
}
$ThisFileInfo['mpeg']['audio']['padding'] = (bool) $ThisFileInfo['mpeg']['audio']['raw']['padding'];
$ThisFileInfo['mpeg']['audio']['bitrate'] = $MPEGaudioBitrateLookup[$ThisFileInfo['mpeg']['audio']['version']][$ThisFileInfo['mpeg']['audio']['layer']][$ThisFileInfo['mpeg']['audio']['raw']['bitrate']];
if (($ThisFileInfo['mpeg']['audio']['bitrate'] == 'free') && ($offset == $ThisFileInfo['avdataoffset'])) {
// only skip multiple frame check if free-format bitstream found at beginning of file
// otherwise is quite possibly simply corrupted data
$recursivesearch = false;
}
// For Layer II there are some combinations of bitrate and mode which are not allowed.
if (!$FastMPEGheaderScan && ($ThisFileInfo['mpeg']['audio']['layer'] == 'II')) {
$ThisFileInfo['audio']['dataformat'] = 'mp2';
switch ($ThisFileInfo['mpeg']['audio']['channelmode']) {
case 'mono':
if (($ThisFileInfo['mpeg']['audio']['bitrate'] == 'free') || ($ThisFileInfo['mpeg']['audio']['bitrate'] <= 192)) {
// these are ok
} else {
$ThisFileInfo['error'] .= "\n".$ThisFileInfo['mpeg']['audio']['bitrate'].'kbps not allowed in Layer II, '.$ThisFileInfo['mpeg']['audio']['channelmode'].'.';
return false;
}
break;
case 'stereo':
case 'joint stereo':
case 'dual channel':
if (($ThisFileInfo['mpeg']['audio']['bitrate'] == 'free') || ($ThisFileInfo['mpeg']['audio']['bitrate'] == 64) || ($ThisFileInfo['mpeg']['audio']['bitrate'] >= 96)) {
// these are ok
} else {
$ThisFileInfo['error'] .= "\n".$ThisFileInfo['mpeg']['audio']['bitrate'].'kbps not allowed in Layer II, '.$ThisFileInfo['mpeg']['audio']['channelmode'].'.';
return false;
}
break;
}
}
if ($ThisFileInfo['audio']['sample_rate'] > 0) {
$ThisFileInfo['mpeg']['audio']['framelength'] = MPEGaudioFrameLength($ThisFileInfo['mpeg']['audio']['bitrate'], $ThisFileInfo['mpeg']['audio']['version'], $ThisFileInfo['mpeg']['audio']['layer'], (int) $ThisFileInfo['mpeg']['audio']['padding'], $ThisFileInfo['audio']['sample_rate']);
}
$nextframetestoffset = $offset + 1;
if ($ThisFileInfo['mpeg']['audio']['bitrate'] != 'free') {
$ThisFileInfo['audio']['bitrate'] = 1000 * $ThisFileInfo['mpeg']['audio']['bitrate'];
if (!empty($ThisFileInfo['mpeg']['audio']['framelength'])) {
$nextframetestoffset = $offset + $ThisFileInfo['mpeg']['audio']['framelength'];
} else {
$ThisFileInfo['error'] .= "\n".'Frame at offset('.$offset.') is has an invalid frame length.';
return false;
}
}
$ExpectedNumberOfAudioBytes = 0;
////////////////////////////////////////////////////////////////////////////////////
// Variable-bitrate headers
if (!$FastMPEGheaderScan) {
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
$ThisFileInfo['mpeg']['audio']['bitrate_mode'] = 'vbr';
$ThisFileInfo['mpeg']['audio']['VBR_method'] = 'Fraunhofer';
$ThisFileInfo['audio']['codec'] = 'Fraunhofer';
$SideInfoData = substr($headerstring, 4 + 2, 32);
$FraunhoferVBROffset = 36;
$ThisFileInfo['mpeg']['audio']['VBR_encoder_version'] = BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 4, 2));
$ThisFileInfo['mpeg']['audio']['VBR_encoder_delay'] = BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 6, 2));
$ThisFileInfo['mpeg']['audio']['VBR_quality'] = BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 8, 2));
$ThisFileInfo['mpeg']['audio']['VBR_bytes'] = BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 10, 4));
$ThisFileInfo['mpeg']['audio']['VBR_frames'] = BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 14, 4));
$ThisFileInfo['mpeg']['audio']['VBR_seek_offsets'] = BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 18, 2));
//$ThisFileInfo['mpeg']['audio']['reserved'] = BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 20, 4)); // hardcoded $00 $01 $00 $02 - purpose unknown
$ThisFileInfo['mpeg']['audio']['VBR_seek_offsets_stride'] = BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 24, 2));
$ExpectedNumberOfAudioBytes = $ThisFileInfo['mpeg']['audio']['VBR_bytes'];
$previousbyteoffset = $offset;
for ($i = 0; $i < $ThisFileInfo['mpeg']['audio']['VBR_seek_offsets']; $i++) {
$Fraunhofer_OffsetN = BigEndian2Int(substr($headerstring, $FraunhoferVBROffset, 2));
$FraunhoferVBROffset += 2;
$ThisFileInfo['mpeg']['audio']['VBR_offsets_relative'][$i] = $Fraunhofer_OffsetN;
$ThisFileInfo['mpeg']['audio']['VBR_offsets_absolute'][$i] = $Fraunhofer_OffsetN + $previousbyteoffset;
$previousbyteoffset += $Fraunhofer_OffsetN;
}
} else {
// Xing VBR header is hardcoded 'Xing' at a offset 0x0D (13), 0x15 (21) or 0x24 (36)
// depending on MPEG layer and number of channels
if ($ThisFileInfo['mpeg']['audio']['version'] == '1') {
if ($ThisFileInfo['mpeg']['audio']['channelmode'] == 'mono') {
// MPEG-1 (mono)
$VBRidOffset = 4 + 17; // 0x15
$SideInfoData = substr($headerstring, 4 + 2, 17);
} else {
// MPEG-1 (stereo, joint-stereo, dual-channel)
$VBRidOffset = 4 + 32; // 0x24
$SideInfoData = substr($headerstring, 4 + 2, 32);
}
} else { // 2 or 2.5
if ($ThisFileInfo['mpeg']['audio']['channelmode'] == 'mono') {
// MPEG-2, MPEG-2.5 (mono)
$VBRidOffset = 4 + 9; // 0x0D
$SideInfoData = substr($headerstring, 4 + 2, 9);
} else {
// MPEG-2, MPEG-2.5 (stereo, joint-stereo, dual-channel)
$VBRidOffset = 4 + 17; // 0x15
$SideInfoData = substr($headerstring, 4 + 2, 17);
}
}
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.)
$ThisFileInfo['mpeg']['audio']['bitrate_mode'] = 'vbr';
$ThisFileInfo['mpeg']['audio']['VBR_method'] = 'Xing';
$ThisFileInfo['mpeg']['audio']['xing_flags_raw'] = BigEndian2Int(substr($headerstring, $VBRidOffset + 4, 4));
$ThisFileInfo['mpeg']['audio']['xing_flags']['frames'] = (bool) ($ThisFileInfo['mpeg']['audio']['xing_flags_raw'] & 0x00000001);
$ThisFileInfo['mpeg']['audio']['xing_flags']['bytes'] = (bool) ($ThisFileInfo['mpeg']['audio']['xing_flags_raw'] & 0x00000002);
$ThisFileInfo['mpeg']['audio']['xing_flags']['toc'] = (bool) ($ThisFileInfo['mpeg']['audio']['xing_flags_raw'] & 0x00000004);
$ThisFileInfo['mpeg']['audio']['xing_flags']['vbr_scale'] = (bool) ($ThisFileInfo['mpeg']['audio']['xing_flags_raw'] & 0x00000008);
if ($ThisFileInfo['mpeg']['audio']['xing_flags']['frames']) {
$ThisFileInfo['mpeg']['audio']['VBR_frames'] = BigEndian2Int(substr($headerstring, $VBRidOffset + 8, 4));
}
if ($ThisFileInfo['mpeg']['audio']['xing_flags']['bytes']) {
$ThisFileInfo['mpeg']['audio']['VBR_bytes'] = BigEndian2Int(substr($headerstring, $VBRidOffset + 12, 4));
}
if (($ThisFileInfo['mpeg']['audio']['bitrate'] == 'free') && !empty($ThisFileInfo['mpeg']['audio']['VBR_frames']) && !empty($ThisFileInfo['mpeg']['audio']['VBR_bytes'])) {
$framelengthfloat = $ThisFileInfo['mpeg']['audio']['VBR_bytes'] / $ThisFileInfo['mpeg']['audio']['VBR_frames'];
if ($ThisFileInfo['mpeg']['audio']['layer'] == 'I') {
// BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
$ThisFileInfo['audio']['bitrate'] = ((($framelengthfloat / 4) - intval($ThisFileInfo['mpeg']['audio']['padding'])) * $ThisFileInfo['mpeg']['audio']['sample_rate']) / 12;
} else {
// Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
$ThisFileInfo['audio']['bitrate'] = (($framelengthfloat - intval($ThisFileInfo['mpeg']['audio']['padding'])) * $ThisFileInfo['mpeg']['audio']['sample_rate']) / 144;
}
$ThisFileInfo['mpeg']['audio']['framelength'] = floor($framelengthfloat);
}
if ($ThisFileInfo['mpeg']['audio']['xing_flags']['toc']) {
$LAMEtocData = substr($headerstring, $VBRidOffset + 16, 100);
for ($i = 0; $i < 100; $i++) {
$ThisFileInfo['mpeg']['audio']['toc'][$i] = ord($LAMEtocData{$i});
}
}
if ($ThisFileInfo['mpeg']['audio']['xing_flags']['vbr_scale']) {
$ThisFileInfo['mpeg']['audio']['VBR_scale'] = BigEndian2Int(substr($headerstring, $VBRidOffset + 116, 4));
}
// http://gabriel.mp3-tech.org/mp3infotag.html
if (substr($headerstring, $VBRidOffset + 120, 4) == 'LAME') {
$ThisFileInfo['mpeg']['audio']['LAME']['long_version'] = substr($headerstring, $VBRidOffset + 120, 20);
$ThisFileInfo['mpeg']['audio']['LAME']['short_version'] = substr($ThisFileInfo['mpeg']['audio']['LAME']['long_version'], 0, 9);
$ThisFileInfo['mpeg']['audio']['LAME']['long_version'] = rtrim($ThisFileInfo['mpeg']['audio']['LAME']['long_version'], "\x55\xAA");
if ($ThisFileInfo['mpeg']['audio']['LAME']['short_version'] >= 'LAME3.90.') {
// 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;
// byte $9B VBR Quality
// This field is there to indicate a quality level, although the scale was not precised in the original Xing specifications.
// Actually overwrites original Xing bytes
unset($ThisFileInfo['mpeg']['audio']['VBR_scale']);
$ThisFileInfo['mpeg']['audio']['LAME']['vbr_quality'] = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0x9B, 1));
// bytes $9C-$A4 Encoder short VersionString
$ThisFileInfo['mpeg']['audio']['LAME']['short_version'] = substr($headerstring, $LAMEtagOffsetContant + 0x9C, 9);
$ThisFileInfo['mpeg']['audio']['LAME']['long_version'] = $ThisFileInfo['mpeg']['audio']['LAME']['short_version'];
// byte $A5 Info Tag revision + VBR method
$LAMEtagRevisionVBRmethod = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA5, 1));
$ThisFileInfo['mpeg']['audio']['LAME']['tag_revision'] = ($LAMEtagRevisionVBRmethod & 0xF0) >> 4;
$ThisFileInfo['mpeg']['audio']['LAME']['raw']['vbr_method'] = $LAMEtagRevisionVBRmethod & 0x0F;
$ThisFileInfo['mpeg']['audio']['LAME']['vbr_method'] = LAMEvbrMethodLookup($ThisFileInfo['mpeg']['audio']['LAME']['raw']['vbr_method']);
// byte $A6 Lowpass filter value
$ThisFileInfo['mpeg']['audio']['LAME']['lowpass_frequency'] = BigEndian2Int(substr($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"
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['peak_amplitude'] = BigEndian2Float(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4));
$ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_radio'] = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAB, 2));
$ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_audiophile'] = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAD, 2));
if ($ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['peak_amplitude'] == 0) {
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['peak_amplitude'] = false;
}
if ($ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_radio'] != 0) {
require_once(GETID3_INCLUDEPATH.'getid3.rgad.php');
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['raw']['name'] = ($ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_radio'] & 0xE000) >> 13;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['raw']['originator'] = ($ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_radio'] & 0x1C00) >> 10;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['raw']['sign_bit'] = ($ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_radio'] & 0x0200) >> 9;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['raw']['gain_adjust'] = $ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_radio'] & 0x01FF;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['name'] = RGADnameLookup($ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['raw']['name']);
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['originator'] = RGADoriginatorLookup($ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['raw']['originator']);
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['gain_db'] = RGADadjustmentLookup($ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['raw']['gain_adjust'], $ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['raw']['sign_bit']);
if ($ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['peak_amplitude'] !== false) {
$ThisFileInfo['replay_gain']['radio']['peak'] = $ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['peak_amplitude'];
}
$ThisFileInfo['replay_gain']['radio']['originator'] = $ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['originator'];
$ThisFileInfo['replay_gain']['radio']['adjustment'] = $ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['gain_db'];
}
if ($ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_audiophile'] != 0) {
require_once(GETID3_INCLUDEPATH.'getid3.rgad.php');
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['raw']['name'] = ($ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_audiophile'] & 0xE000) >> 13;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['raw']['originator'] = ($ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_audiophile'] & 0x1C00) >> 10;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['raw']['sign_bit'] = ($ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_audiophile'] & 0x0200) >> 9;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['raw']['gain_adjust'] = $ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_audiophile'] & 0x01FF;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['name'] = RGADnameLookup($ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['raw']['name']);
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['originator'] = RGADoriginatorLookup($ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['raw']['originator']);
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['gain_db'] = RGADadjustmentLookup($ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['raw']['gain_adjust'], $ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['raw']['sign_bit']);
if ($ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['peak_amplitude'] !== false) {
$ThisFileInfo['replay_gain']['audiophile']['peak'] = $ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['peak_amplitude'];
}
$ThisFileInfo['replay_gain']['audiophile']['originator'] = $ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['originator'];
$ThisFileInfo['replay_gain']['audiophile']['adjustment'] = $ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['gain_db'];
}
// byte $AF Encoding flags + ATH Type
$EncodingFlagsATHtype = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAF, 1));
$ThisFileInfo['mpeg']['audio']['LAME']['encoding_flags']['nspsytune'] = (bool) ($EncodingFlagsATHtype & 0x10);
$ThisFileInfo['mpeg']['audio']['LAME']['encoding_flags']['nssafejoint'] = (bool) ($EncodingFlagsATHtype & 0x20);
$ThisFileInfo['mpeg']['audio']['LAME']['encoding_flags']['nogap_next'] = (bool) ($EncodingFlagsATHtype & 0x40);
$ThisFileInfo['mpeg']['audio']['LAME']['encoding_flags']['nogap_prev'] = (bool) ($EncodingFlagsATHtype & 0x80);
$ThisFileInfo['mpeg']['audio']['LAME']['ath_type'] = $EncodingFlagsATHtype & 0x0F;
// byte $B0 if ABR {specified bitrate} else {minimal bitrate}
$ABRbitrateMinBitrate = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB0, 1));
if ($ThisFileInfo['mpeg']['audio']['LAME']['raw']['vbr_method'] == 2) { // Average BitRate (ABR)
$ThisFileInfo['mpeg']['audio']['LAME']['bitrate_abr'] = $ABRbitrateMinBitrate;
} elseif ($ABRbitrateMinBitrate > 0) { // Variable BitRate (VBR) - minimum bitrate
$ThisFileInfo['mpeg']['audio']['LAME']['bitrate_min'] = $ABRbitrateMinBitrate;
}
// bytes $B1-$B3 Encoder delays
$EncoderDelays = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB1, 3));
$ThisFileInfo['mpeg']['audio']['LAME']['encoder_delay'] = ($EncoderDelays & 0xFFF000) >> 12;
$ThisFileInfo['mpeg']['audio']['LAME']['end_padding'] = $EncoderDelays & 0x000FFF;
// byte $B4 Misc
$MiscByte = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB4, 1));
$ThisFileInfo['mpeg']['audio']['LAME']['raw']['noise_shaping'] = ($MiscByte & 0x03);
$ThisFileInfo['mpeg']['audio']['LAME']['raw']['stereo_mode'] = ($MiscByte & 0x1C) >> 2;
$ThisFileInfo['mpeg']['audio']['LAME']['raw']['not_optimal_quality'] = ($MiscByte & 0x20) >> 5;
$ThisFileInfo['mpeg']['audio']['LAME']['raw']['source_sample_freq'] = ($MiscByte & 0xC0) >> 6;
$ThisFileInfo['mpeg']['audio']['LAME']['noise_shaping'] = $ThisFileInfo['mpeg']['audio']['LAME']['raw']['noise_shaping'];
$ThisFileInfo['mpeg']['audio']['LAME']['stereo_mode'] = LAMEmiscStereoModeLookup($ThisFileInfo['mpeg']['audio']['LAME']['raw']['stereo_mode']);
$ThisFileInfo['mpeg']['audio']['LAME']['not_optimal_quality'] = (bool) $ThisFileInfo['mpeg']['audio']['LAME']['raw']['not_optimal_quality'];
$ThisFileInfo['mpeg']['audio']['LAME']['source_sample_freq'] = LAMEmiscSourceSampleFrequencyLookup($ThisFileInfo['mpeg']['audio']['LAME']['raw']['source_sample_freq']);
// byte $B5 MP3 Gain
$ThisFileInfo['mpeg']['audio']['LAME']['raw']['mp3_gain'] = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB5, 1), false, true);
$ThisFileInfo['mpeg']['audio']['LAME']['mp3_gain_db'] = 1.5 * $ThisFileInfo['mpeg']['audio']['LAME']['raw']['mp3_gain'];
$ThisFileInfo['mpeg']['audio']['LAME']['mp3_gain_factor'] = pow(2, ($ThisFileInfo['mpeg']['audio']['LAME']['mp3_gain_db'] / 6));
// bytes $B6-$B7 Preset and surround info
$PresetSurroundBytes = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB6, 2));
// Reserved = ($PresetSurroundBytes & 0xC000);
$ThisFileInfo['mpeg']['audio']['LAME']['raw']['surround_info'] = ($PresetSurroundBytes & 0x3800);
$ThisFileInfo['mpeg']['audio']['LAME']['surround_info'] = LAMEsurroundInfoLookup($ThisFileInfo['mpeg']['audio']['LAME']['raw']['surround_info']);
$ThisFileInfo['mpeg']['audio']['LAME']['preset_used_id'] = ($PresetSurroundBytes & 0x07FF);
// bytes $B8-$BB MusicLength
$ThisFileInfo['mpeg']['audio']['LAME']['audio_bytes'] = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB8, 4));
$ExpectedNumberOfAudioBytes = (($ThisFileInfo['mpeg']['audio']['LAME']['audio_bytes'] > 0) ? $ThisFileInfo['mpeg']['audio']['LAME']['audio_bytes'] : $ThisFileInfo['mpeg']['audio']['VBR_bytes']);
// bytes $BC-$BD MusicCRC
$ThisFileInfo['mpeg']['audio']['LAME']['music_crc'] = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBC, 2));
// bytes $BE-$BF CRC-16 of Info Tag
$ThisFileInfo['mpeg']['audio']['LAME']['lame_tag_crc'] = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBE, 2));
// LAME CBR
if ($ThisFileInfo['mpeg']['audio']['LAME']['raw']['vbr_method'] == 1) {
$ThisFileInfo['mpeg']['audio']['bitrate_mode'] = 'cbr';
if (empty($ThisFileInfo['mpeg']['audio']['bitrate']) || ($ThisFileInfo['mpeg']['audio']['LAME']['bitrate_min'] != 255)) {
$ThisFileInfo['mpeg']['audio']['bitrate'] = $ThisFileInfo['mpeg']['audio']['LAME']['bitrate_min'];
}
}
}
}
} else {
// not Fraunhofer or Xing VBR methods, most likely CBR (but could be VBR with no header)
$ThisFileInfo['mpeg']['audio']['bitrate_mode'] = 'cbr';
if ($recursivesearch) {
$ThisFileInfo['mpeg']['audio']['bitrate_mode'] = 'vbr';
if (RecursiveFrameScanning($fd, $ThisFileInfo, $offset, $nextframetestoffset, true)) {
$recursivesearch = false;
$ThisFileInfo['mpeg']['audio']['bitrate_mode'] = 'cbr';
}
if ($ThisFileInfo['mpeg']['audio']['bitrate_mode'] == 'vbr') {
$ThisFileInfo['warning'] .= "\n".'VBR file with no VBR header. Bitrate values calculated from actual frame bitrates.';
}
}
}
}
}
if (($ExpectedNumberOfAudioBytes > 0) && ($ExpectedNumberOfAudioBytes != ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']))) {
if (($ExpectedNumberOfAudioBytes - ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset'])) == 1) {
$ThisFileInfo['warning'] .= "\n".'Last byte of data truncated (this is a known bug in Meracl ID3 Tag Writer before v1.3.5)';
} elseif ($ExpectedNumberOfAudioBytes > ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset'])) {
$ThisFileInfo['warning'] .= "\n".'Probable truncated file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, only found '.($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']).' (short by '.($ExpectedNumberOfAudioBytes - ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset'])).' bytes)';
} else {
$ThisFileInfo['warning'] .= "\n".'Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']).' ('.(($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)';
}
}
if (($ThisFileInfo['mpeg']['audio']['bitrate'] == 'free') && empty($ThisFileInfo['audio']['bitrate'])) {
if (($offset == $ThisFileInfo['avdataoffset']) && empty($ThisFileInfo['mpeg']['audio']['VBR_frames'])) {
$framebytelength = FreeFormatFrameLength($fd, $offset, $ThisFileInfo, true);
if ($framebytelength > 0) {
$ThisFileInfo['mpeg']['audio']['framelength'] = $framebytelength;
if ($ThisFileInfo['mpeg']['audio']['layer'] == 'I') {
// BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
$ThisFileInfo['audio']['bitrate'] = ((($framebytelength / 4) - intval($ThisFileInfo['mpeg']['audio']['padding'])) * $ThisFileInfo['mpeg']['audio']['sample_rate']) / 12;
} else {
// Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
$ThisFileInfo['audio']['bitrate'] = (($framebytelength - intval($ThisFileInfo['mpeg']['audio']['padding'])) * $ThisFileInfo['mpeg']['audio']['sample_rate']) / 144;
}
} else {
$ThisFileInfo['error'] .= "\n".'Error calculating frame length of free-format MP3 without Xing/LAME header';
}
}
}
if (($ThisFileInfo['mpeg']['audio']['bitrate_mode'] == 'vbr') && isset($ThisFileInfo['mpeg']['audio']['VBR_frames']) && ($ThisFileInfo['mpeg']['audio']['VBR_frames'] > 1)) {
$ThisFileInfo['mpeg']['audio']['VBR_frames']--; // don't count the Xing / VBRI frame
if (($ThisFileInfo['mpeg']['audio']['version'] == '1') && ($ThisFileInfo['mpeg']['audio']['layer'] == 'I')) {
$ThisFileInfo['mpeg']['audio']['VBR_bitrate'] = ((($ThisFileInfo['mpeg']['audio']['VBR_bytes'] / $ThisFileInfo['mpeg']['audio']['VBR_frames']) * 8) * ($ThisFileInfo['audio']['sample_rate'] / 384)) / 1000;
} elseif ((($ThisFileInfo['mpeg']['audio']['version'] == '2') || ($ThisFileInfo['mpeg']['audio']['version'] == '2.5')) && ($ThisFileInfo['mpeg']['audio']['layer'] == 'III')) {
$ThisFileInfo['mpeg']['audio']['VBR_bitrate'] = ((($ThisFileInfo['mpeg']['audio']['VBR_bytes'] / $ThisFileInfo['mpeg']['audio']['VBR_frames']) * 8) * ($ThisFileInfo['audio']['sample_rate'] / 576)) / 1000;
} else {
$ThisFileInfo['mpeg']['audio']['VBR_bitrate'] = ((($ThisFileInfo['mpeg']['audio']['VBR_bytes'] / $ThisFileInfo['mpeg']['audio']['VBR_frames']) * 8) * ($ThisFileInfo['audio']['sample_rate'] / 1152)) / 1000;
}
if ($ThisFileInfo['mpeg']['audio']['VBR_bitrate'] > 0) {
$ThisFileInfo['audio']['bitrate'] = 1000 * $ThisFileInfo['mpeg']['audio']['VBR_bitrate'];
$ThisFileInfo['mpeg']['audio']['bitrate'] = $ThisFileInfo['mpeg']['audio']['VBR_bitrate']; // to avoid confusion
}
}
// End variable-bitrate headers
////////////////////////////////////////////////////////////////////////////////////
if ($recursivesearch) {
if (!RecursiveFrameScanning($fd, $ThisFileInfo, $offset, $nextframetestoffset, $ScanAsCBR)) {
return false;
}
}
//if (false) {
// // experimental side info parsing section - not returning anything useful yet
//
// $SideInfoBitstream = BigEndian2Bin($SideInfoData);
// $SideInfoOffset = 0;
//
// if ($ThisFileInfo['mpeg']['audio']['version'] == '1') {
// if ($ThisFileInfo['mpeg']['audio']['channelmode'] == 'mono') {
// // MPEG-1 (mono)
// $ThisFileInfo['mpeg']['audio']['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
// $SideInfoOffset += 9;
// $SideInfoOffset += 5;
// } else {
// // MPEG-1 (stereo, joint-stereo, dual-channel)
// $ThisFileInfo['mpeg']['audio']['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
// $SideInfoOffset += 9;
// $SideInfoOffset += 3;
// }
// } else { // 2 or 2.5
// if ($ThisFileInfo['mpeg']['audio']['channelmode'] == 'mono') {
// // MPEG-2, MPEG-2.5 (mono)
// $ThisFileInfo['mpeg']['audio']['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
// $SideInfoOffset += 8;
// $SideInfoOffset += 1;
// } else {
// // MPEG-2, MPEG-2.5 (stereo, joint-stereo, dual-channel)
// $ThisFileInfo['mpeg']['audio']['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
// $SideInfoOffset += 8;
// $SideInfoOffset += 2;
// }
// }
//
// if ($ThisFileInfo['mpeg']['audio']['version'] == '1') {
// for ($channel = 0; $channel < $ThisFileInfo['audio']['channels']; $channel++) {
// for ($scfsi_band = 0; $scfsi_band < 4; $scfsi_band++) {
// $ThisFileInfo['mpeg']['audio']['scfsi'][$channel][$scfsi_band] = substr($SideInfoBitstream, $SideInfoOffset, 1);
// $SideInfoOffset += 2;
// }
// }
// }
// for ($granule = 0; $granule < (($ThisFileInfo['mpeg']['audio']['version'] == '1') ? 2 : 1); $granule++) {
// for ($channel = 0; $channel < $ThisFileInfo['audio']['channels']; $channel++) {
// $ThisFileInfo['mpeg']['audio']['part2_3_length'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 12);
// $SideInfoOffset += 12;
// $ThisFileInfo['mpeg']['audio']['big_values'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
// $SideInfoOffset += 9;
// $ThisFileInfo['mpeg']['audio']['global_gain'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 8);
// $SideInfoOffset += 8;
// if ($ThisFileInfo['mpeg']['audio']['version'] == '1') {
// $ThisFileInfo['mpeg']['audio']['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
// $SideInfoOffset += 4;
// } else {
// $ThisFileInfo['mpeg']['audio']['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
// $SideInfoOffset += 9;
// }
// $ThisFileInfo['mpeg']['audio']['window_switching_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
// $SideInfoOffset += 1;
//
// if ($ThisFileInfo['mpeg']['audio']['window_switching_flag'][$granule][$channel] == '1') {
//
// $ThisFileInfo['mpeg']['audio']['block_type'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 2);
// $SideInfoOffset += 2;
// $ThisFileInfo['mpeg']['audio']['mixed_block_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
// $SideInfoOffset += 1;
//
// for ($region = 0; $region < 2; $region++) {
// $ThisFileInfo['mpeg']['audio']['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
// $SideInfoOffset += 5;
// }
// $ThisFileInfo['mpeg']['audio']['table_select'][$granule][$channel][2] = 0;
//
// for ($window = 0; $window < 3; $window++) {
// $ThisFileInfo['mpeg']['audio']['subblock_gain'][$granule][$channel][$window] = substr($SideInfoBitstream, $SideInfoOffset, 3);
// $SideInfoOffset += 3;
// }
//
// } else {
//
// for ($region = 0; $region < 3; $region++) {
// $ThisFileInfo['mpeg']['audio']['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
// $SideInfoOffset += 5;
// }
//
// $ThisFileInfo['mpeg']['audio']['region0_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
// $SideInfoOffset += 4;
// $ThisFileInfo['mpeg']['audio']['region1_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 3);
// $SideInfoOffset += 3;
// $ThisFileInfo['mpeg']['audio']['block_type'][$granule][$channel] = 0;
// }
//
// if ($ThisFileInfo['mpeg']['audio']['version'] == '1') {
// $ThisFileInfo['mpeg']['audio']['preflag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
// $SideInfoOffset += 1;
// }
// $ThisFileInfo['mpeg']['audio']['scalefac_scale'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
// $SideInfoOffset += 1;
// $ThisFileInfo['mpeg']['audio']['count1table_select'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
// $SideInfoOffset += 1;
// }
// }
//}
return true;
}
function RecursiveFrameScanning(&$fd, &$ThisFileInfo, &$offset, &$nextframetestoffset, $ScanAsCBR) {
for ($i = 0; $i < MPEG_VALID_CHECK_FRAMES; $i++) {
// check next MPEG_VALID_CHECK_FRAMES frames for validity, to make sure we haven't run across a false synch
if (($nextframetestoffset + 4) >= $ThisFileInfo['avdataend']) {
// end of file
return true;
}
$nextframetestarray = array('error'=>'', 'warning'=>'', 'avdataend'=>$ThisFileInfo['avdataend'], 'avdataoffset'=>$ThisFileInfo['avdataoffset']);
if (decodeMPEGaudioHeader($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 {
$ThisFileInfo['error'] .= "\n".'Frame at offset ('.$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
$ThisFileInfo['error'] .= "\n".'Frame at offset ('.$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) {
$ThisFileInfo['error'] .= "\n".'Cannot find next free-format synch pattern ('.PrintHexBytes($SyncPattern1).' or '.PrintHexBytes($SyncPattern2).') after offset '.$offset;
return false;
} else {
$ThisFileInfo['warning'] .= "\n".'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 {
$ThisFileInfo['error'] .= "\n".'Did not find expected free-format sync pattern at offset '.$nextoffset;
return false;
}
$nextoffset += $framelength;
}
if (count($ActualFrameLengthValues) > 0) {
$framelength = round(array_sum($ActualFrameLengthValues) / count($ActualFrameLengthValues));
}
}
return $framelength;
}
function getOnlyMPEGaudioInfo($fd, &$ThisFileInfo, $avdataoffset, $BitrateHistogram=false) {
// looks for synch, decodes MPEG audio header
fseek($fd, $avdataoffset, SEEK_SET);
$header = '';
$SynchSeekOffset = 0;
if (!defined('CONST_FF')) {
define('CONST_FF', chr(0xFF));
define('CONST_E0', chr(0xE0));
}
static $MPEGaudioVersionLookup;
static $MPEGaudioLayerLookup;
static $MPEGaudioBitrateLookup;
if (empty($MPEGaudioVersionLookup)) {
$MPEGaudioVersionLookup = MPEGaudioVersionArray();
$MPEGaudioLayerLookup = MPEGaudioLayerArray();
$MPEGaudioBitrateLookup = MPEGaudioBitrateArray();
}
static $MPEGaudioHeaderValidCache = array();
$header_len = strlen($header) - round(FREAD_BUFFER_SIZE / 2);
while (true) {
if (($SynchSeekOffset > $header_len) && (($avdataoffset + $SynchSeekOffset) < $ThisFileInfo['avdataend']) && !feof($fd)) {
if ($SynchSeekOffset > 131072) {
// if a synch's not found within the first 128k bytes, then give up
$ThisFileInfo['error'] .= "\n".'could not find valid MPEG synch within the first 131072 bytes';
if (isset($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($ThisFileInfo['mpeg']);
}
return false;
} elseif ($header .= fread($fd, FREAD_BUFFER_SIZE)) {
// great
$header_len = strlen($header) - round(FREAD_BUFFER_SIZE / 2);
} else {
$ThisFileInfo['error'] .= "\n".'could not find valid MPEG synch before end of file';
if (isset($ThisFileInfo['audio']['bitrate'])) {
unset($ThisFileInfo['audio']['bitrate']);
}
if (isset($ThisFileInfo['mpeg']['audio'])) {
unset($ThisFileInfo['mpeg']['audio']);
}
if (isset($ThisFileInfo['mpeg']) && (!is_array($ThisFileInfo['mpeg']) || (count($ThisFileInfo['mpeg']) == 0))) {
unset($ThisFileInfo['mpeg']);
}
return false;
}
}
if (($SynchSeekOffset + 1) >= strlen($header)) {
$ThisFileInfo['error'] .= "\n".'could not find valid MPEG synch before end of file';
return false;
}
if ($header{$SynchSeekOffset} == CONST_FF) {
if ($header{($SynchSeekOffset + 1)} > CONST_E0) {
$head4 = substr($header, $SynchSeekOffset, 4);
if (!isset($MPEGaudioHeaderValidCache[$head4])) {
$MPEGaudioHeaderValidCache[$head4] = MPEGaudioHeaderBytesValid($head4);
}
if ($MPEGaudioHeaderValidCache[$head4]) { // synch detected
if (!isset($FirstFrameThisfileInfo) && !isset($ThisFileInfo['mpeg']['audio'])) {
$FirstFrameThisfileInfo = $ThisFileInfo;
$FirstFrameAVDataOffset = $avdataoffset + $SynchSeekOffset;
if (!decodeMPEGaudioHeader($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 = $ThisFileInfo; // only overwrite real data if valid header found
if (decodeMPEGaudioHeader($fd, $avdataoffset + $SynchSeekOffset, $dummy, true)) {
$ThisFileInfo = $dummy;
$ThisFileInfo['avdataoffset'] = $avdataoffset + $SynchSeekOffset;
switch ($ThisFileInfo['fileformat']) {
case '':
case 'id3':
case 'ape':
case 'mp3':
$ThisFileInfo['fileformat'] = 'mp3';
$ThisFileInfo['audio']['dataformat'] = 'mp3';
}
if (isset($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode']) && ($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode'] == 'vbr')) {
if (!CloseMatch($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 + $SynchSeekOffset;
if (decodeMPEGaudioHeader($fd, $GarbageOffsetEnd, $dummy, true, true)) {
$ThisFileInfo = $dummy;
$ThisFileInfo['avdataoffset'] = $GarbageOffsetEnd;
$ThisFileInfo['warning'] .= "\n".'apparently-valid VBR header not used because could not find '.MPEG_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.'), but did find valid CBR stream starting at '.$GarbageOffsetEnd;
} else {
$ThisFileInfo['warning'] .= "\n".'using data from VBR header even though could not find '.MPEG_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($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'] == 'III') {
$ThisFileInfo['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32=>0, 40=>0, 48=>0, 56=>0, 64=>0, 80=>0, 96=>0, 112=>0, 128=>0, 160=>0, 192=>0, 224=>0, 256=>0, 320=>0);
} elseif ($ThisFileInfo['mpeg']['audio']['layer'] == 'II') {
$ThisFileInfo['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32=>0, 48=>0, 56=>0, 64=>0, 80=>0, 96=>0, 112=>0, 128=>0, 160=>0, 192=>0, 224=>0, 256=>0, 320=>0, 384=>0);
} elseif ($ThisFileInfo['mpeg']['audio']['layer'] == 'I') {
$ThisFileInfo['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32=>0, 64=>0, 96=>0, 128=>0, 160=>0, 192=>0, 224=>0, 256=>0, 288=>0, 320=>0, 352=>0, 384=>0, 416=>0, 448=>0);
}
} elseif ($ThisFileInfo['mpeg']['audio']['layer'] == 'I') {
$ThisFileInfo['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32=>0, 48=>0, 56=>0, 64=>0, 80=>0, 96=>0, 112=>0, 128=>0, 144=>0, 160=>0, 176=>0, 192=>0, 224=>0, 256=>0);
} else {
$ThisFileInfo['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 8=>0, 16=>0, 24=>0, 32=>0, 40=>0, 48=>0, 56=>0, 64=>0, 80=>0, 96=>0, 112=>0, 128=>0, 144=>0, 160=>0);
}
$dummy = array('error'=>$ThisFileInfo['error'], 'warning'=>$ThisFileInfo['warning'], 'avdataend'=>$ThisFileInfo['avdataend'], 'avdataoffset'=>$ThisFileInfo['avdataoffset']);
$synchstartoffset = $ThisFileInfo['avdataoffset'];
$FastMode = false;
while ($synchstartoffset < ($ThisFileInfo['avdataend'] - 12)) {
if (decodeMPEGaudioHeader($fd, $synchstartoffset, $dummy, false, false, $FastMode, true)) {
$thisframebitrate = $MPEGaudioBitrateLookup[$MPEGaudioVersionLookup[$dummy['mpeg']['audio']['raw']['version']]][$MPEGaudioLayerLookup[$dummy['mpeg']['audio']['raw']['layer']]][$dummy['mpeg']['audio']['raw']['bitrate']];
safe_inc($ThisFileInfo['mpeg']['audio']['bitrate_distribution'][$thisframebitrate]);
$ThisFileInfo['mpeg']['audio']['stereo_distribution'][$dummy['mpeg']['audio']['channelmode']]++;
$ThisFileInfo['mpeg']['audio']['version_distribution'][$dummy['mpeg']['audio']['version']]++;
if (empty($dummy['mpeg']['audio']['framelength'])) {
$ThisFileInfo['warning'] .= "\n".'Invalid/missing framelength at '.$synchstartoffset.' in histogram analysis - aborting';
$synchstartoffset++;
$ThisFileInfo['avdataoffset'] = $synchstartoffset;
// return false;
} else {
$synchstartoffset += $dummy['mpeg']['audio']['framelength'];
}
} else {
//$ThisFileInfo['warning'] .= "\n".'Invalid frame header at '.$synchstartoffset;
$synchstartoffset++;
$ThisFileInfo['avdataoffset'] = $synchstartoffset;
}
$FastMode = true;
}
$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'] .= "\n".'Corrupt MP3 file: framecounter == zero';
return false;
}
$ThisFileInfo['mpeg']['audio']['frame_count'] = $framecounter;
$ThisFileInfo['mpeg']['audio']['bitrate'] = 1000 * ($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'])) {
$ThisFileInfo['error'] .= "\n".'could not find valid MPEG synch before end of file';
if (isset($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']['bits_per_sample'] = 16;
$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, 'III', 'II', 'I');
return $MPEGaudioLayer;
}
function MPEGaudioBitrateArray() {
static $MPEGaudioBitrate;
if (empty($MPEGaudioBitrate)) {
$MPEGaudioBitrate['1']['I'] = array('free', 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448);
$MPEGaudioBitrate['1']['II'] = array('free', 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384);
$MPEGaudioBitrate['1']['III'] = array('free', 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320);
$MPEGaudioBitrate['2']['I'] = array('free', 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256);
$MPEGaudioBitrate['2']['II'] = array('free', 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160);
$MPEGaudioBitrate['2']['III'] = $MPEGaudioBitrate['2']['II'];
$MPEGaudioBitrate['2.5']['I'] = $MPEGaudioBitrate['2']['I'];
$MPEGaudioBitrate['2.5']['II'] = $MPEGaudioBitrate['2']['II'];
$MPEGaudioBitrate['2.5']['III'] = $MPEGaudioBitrate['2']['III'];
}
return $MPEGaudioBitrate;
}
function MPEGaudioFrequencyArray() {
static $MPEGaudioFrequency;
if (empty($MPEGaudioFrequency)) {
$MPEGaudioFrequency['1'] = array(44100, 48000, 32000);
$MPEGaudioFrequency['2'] = array(22050, 24000, 16000);
$MPEGaudioFrequency['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['I'] = array('4-31', '8-31', '12-31', '16-31');
$MPEGaudioModeExtension['II'] = array('4-31', '8-31', '12-31', '16-31');
$MPEGaudioModeExtension['III'] = array('', 'IS', 'MS', 'IS+MS');
}
return $MPEGaudioModeExtension;
}
function MPEGaudioEmphasisArray() {
static $MPEGaudioEmphasis = array('none', '50/15ms', false, 'CCIT J.17');
return $MPEGaudioEmphasis;
}
function MPEGaudioHeaderBytesValid($head4) {
return MPEGaudioHeaderValid(MPEGaudioHeaderDecode($head4));
}
function MPEGaudioHeaderValid($rawarray, $echoerrors=false) {
if (($rawarray['synch'] & 0x0FFE) != 0x0FFE) {
return false;
}
static $MPEGaudioVersionLookup;
static $MPEGaudioLayerLookup;
static $MPEGaudioBitrateLookup;
static $MPEGaudioFrequencyLookup;
static $MPEGaudioChannelModeLookup;
static $MPEGaudioModeExtensionLookup;
static $MPEGaudioEmphasisLookup;
if (empty($MPEGaudioVersionLookup)) {
$MPEGaudioVersionLookup = MPEGaudioVersionArray();
$MPEGaudioLayerLookup = MPEGaudioLayerArray();
$MPEGaudioBitrateLookup = MPEGaudioBitrateArray();
$MPEGaudioFrequencyLookup = MPEGaudioFrequencyArray();
$MPEGaudioChannelModeLookup = MPEGaudioChannelModeArray();
$MPEGaudioModeExtensionLookup = MPEGaudioModeExtensionArray();
$MPEGaudioEmphasisLookup = MPEGaudioEmphasisArray();
}
if (isset($MPEGaudioVersionLookup[$rawarray['version']])) {
$decodedVersion = $MPEGaudioVersionLookup[$rawarray['version']];
} else {
if ($echoerrors) {
echo "\n".'invalid Version ('.$rawarray['version'].')';
}
return false;
}
if (isset($MPEGaudioLayerLookup[$rawarray['layer']])) {
$decodedLayer = $MPEGaudioLayerLookup[$rawarray['layer']];
} else {
if ($echoerrors) {
echo "\n".'invalid Layer ('.$rawarray['layer'].')';
}
return false;
}
if (!isset($MPEGaudioBitrateLookup[$decodedVersion][$decodedLayer][$rawarray['bitrate']])) {
if ($echoerrors) {
echo "\n".'invalid Bitrate ('.$rawarray['bitrate'].')';
}
if ($rawarray['bitrate'] == 15) {
// known issue in LAME 3.90 - 3.93.1 where free-format has bitrate ID of 15 instead of 0
// let it go through here otherwise file will not be identified
} else {
return false;
}
}
if (!isset($MPEGaudioFrequencyLookup[$decodedVersion][$rawarray['sample_rate']])) {
if ($echoerrors) {
echo "\n".'invalid Frequency ('.$rawarray['sample_rate'].')';
}
return false;
}
if (!isset($MPEGaudioChannelModeLookup[$rawarray['channelmode']])) {
if ($echoerrors) {
echo "\n".'invalid ChannelMode ('.$rawarray['channelmode'].')';
}
return false;
}
if (!isset($MPEGaudioModeExtensionLookup[$decodedLayer][$rawarray['modeextension']])) {
if ($echoerrors) {
echo "\n".'invalid Mode Extension ('.$rawarray['modeextension'].')';
}
return false;
}
if (!isset($MPEGaudioEmphasisLookup[$rawarray['emphasis']])) {
if ($echoerrors) {
echo "\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;
}
$MPEGrawHeader['synch'] = (BigEndian2Int(substr($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 == 'I') {
// For Layer I slot is 32 bits long
$FrameLengthCoefficient = 48;
$FrameLengthPadding = ($padding ? 4 : 0);
} else { // Layer II / III
// for Layer II and Layer III slot is 8 bits long.
$FrameLengthCoefficient = 144;
$FrameLengthPadding = ($padding ? 1 : 0);
}
} else { // MPEG-2 / MPEG-2.5
if ($layer == 'I') {
// For Layer I slot is 32 bits long
$FrameLengthCoefficient = 24;
$FrameLengthPadding = ($padding ? 4 : 0);
} else { // Layer II / III
// for Layer II and Layer III slot is 8 bits long.
$FrameLengthCoefficient = 72;
$FrameLengthPadding = ($padding ? 1 : 0);
}
}
// FrameLengthInBytes = ((Coefficient * BitRate) / SampleRate) + Padding
// http://66.96.216.160/cgi-bin/YaBB.pl?board=c&action=display&num=1018474068
// -> [Finding the next frame synch] on www.r3mix.net forums if the above link goes dead
if ($samplerate > 0) {
$AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = (int) floor(($FrameLengthCoefficient * 1000 * $bitrate) / $samplerate) + $FrameLengthPadding;
}
}
}
return $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate];
}
function LAMEvbrMethodLookup($VBRmethodID) {
static $LAMEvbrMethodLookup = array();
if (empty($LAMEvbrMethodLookup)) {
$LAMEvbrMethodLookup[0x00] = 'unknown';
$LAMEvbrMethodLookup[0x01] = 'cbr';
$LAMEvbrMethodLookup[0x02] = 'abr';
$LAMEvbrMethodLookup[0x03] = 'vbr-old / vbr-rh';
$LAMEvbrMethodLookup[0x04] = 'vbr-mtrh';
$LAMEvbrMethodLookup[0x05] = 'vbr-new / vbr-mt';
}
return (isset($LAMEvbrMethodLookup[$VBRmethodID]) ? $LAMEvbrMethodLookup[$VBRmethodID] : '');
}
function LAMEmiscStereoModeLookup($StereoModeID) {
static $LAMEmiscStereoModeLookup = array();
if (empty($LAMEmiscStereoModeLookup)) {
$LAMEmiscStereoModeLookup[0] = 'mono';
$LAMEmiscStereoModeLookup[1] = 'stereo';
$LAMEmiscStereoModeLookup[2] = 'dual';
$LAMEmiscStereoModeLookup[3] = 'joint';
$LAMEmiscStereoModeLookup[4] = 'forced';
$LAMEmiscStereoModeLookup[5] = 'auto';
$LAMEmiscStereoModeLookup[6] = 'intensity';
$LAMEmiscStereoModeLookup[7] = 'other';
}
return (isset($LAMEmiscStereoModeLookup[$StereoModeID]) ? $LAMEmiscStereoModeLookup[$StereoModeID] : '');
}
function LAMEmiscSourceSampleFrequencyLookup($SourceSampleFrequencyID) {
static $LAMEmiscSourceSampleFrequencyLookup = array();
if (empty($LAMEmiscSourceSampleFrequencyLookup)) {
$LAMEmiscSourceSampleFrequencyLookup[0] = '<= 32 kHz';
$LAMEmiscSourceSampleFrequencyLookup[1] = '44.1 kHz';
$LAMEmiscSourceSampleFrequencyLookup[2] = '48 kHz';
$LAMEmiscSourceSampleFrequencyLookup[3] = '> 48kHz';
}
return (isset($LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID]) ? $LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID] : '');
}
function LAMEsurroundInfoLookup($SurroundInfoID) {
static $LAMEsurroundInfoLookup = array();
if (empty($LAMEsurroundInfoLookup)) {
$LAMEsurroundInfoLookup[0] = 'no surround info';
$LAMEsurroundInfoLookup[1] = 'DPL encoding';
$LAMEsurroundInfoLookup[2] = 'DPL2 encoding';
$LAMEsurroundInfoLookup[3] = 'Ambisonic encoding';
}
return (isset($LAMEsurroundInfoLookup[$SurroundInfoID]) ? $LAMEsurroundInfoLookup[$SurroundInfoID] : 'reserved');
}
?>
