function decodeMPEGaudioHeader($fd, $offset, &$ThisFileInfo, $recursivesearch = true, $ScanAsCBR = false, $FastMPEGheaderScan = false)
{
static $MPEGaudioVersionLookup;
static $MPEGaudioLayerLookup;
static $MPEGaudioBitrateLookup;
static $MPEGaudioFrequencyLookup;
static $MPEGaudioChannelModeLookup;
static $MPEGaudioModeExtensionLookup;
static $MPEGaudioEmphasisLookup;
if (empty($MPEGaudioVersionLookup)) {
$MPEGaudioVersionLookup = 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';
$ThisFileInfo['mpeg']['audio']['raw']['bitrate'] = 0;
}
$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'], $ThisFileInfo['audio']['sample_rate']);
}
if ($ThisFileInfo['mpeg']['audio']['bitrate'] != 'free') {
$ThisFileInfo['audio']['bitrate'] = 1000 * $ThisFileInfo['mpeg']['audio']['bitrate'];
if (isset($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;
}
}
$ExpectedNumberOfAudioBytes = 0;
////////////////////////////////////////////////////////////////////////////////////
// Variable-bitrate headers
if (substr($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'] & 0x1);
$ThisFileInfo['mpeg']['audio']['xing_flags']['bytes'] = (bool) ($ThisFileInfo['mpeg']['audio']['xing_flags_raw'] & 0x2);
$ThisFileInfo['mpeg']['audio']['xing_flags']['toc'] = (bool) ($ThisFileInfo['mpeg']['audio']['xing_flags_raw'] & 0x4);
$ThisFileInfo['mpeg']['audio']['xing_flags']['vbr_scale'] = (bool) ($ThisFileInfo['mpeg']['audio']['xing_flags_raw'] & 0x8);
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'], "Uª");
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 & 0xf;
$ThisFileInfo['mpeg']['audio']['LAME']['vbr_method'] = LAMEvbrMethodLookup($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'] & 0x200) >> 9;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['raw']['gain_adjust'] = $ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_radio'] & 0x1ff;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['radio']['name'] = RGADnameLookup($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'] & 0x200) >> 9;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['raw']['gain_adjust'] = $ThisFileInfo['mpeg']['audio']['LAME']['raw']['RGAD_audiophile'] & 0x1ff;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['audiophile']['name'] = RGADnameLookup($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 & 0xf;
// 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 & 0xfff;
// byte $B4 Misc
$MiscByte = BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xb4, 1));
$ThisFileInfo['mpeg']['audio']['LAME']['raw']['noise_shaping'] = $MiscByte & 0x3;
$ThisFileInfo['mpeg']['audio']['LAME']['raw']['stereo_mode'] = ($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 & 0x7ff;
// 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);
// $SideInfoOffset += 1;
// }
// }
//}
return true;
}
function decodeMPEGaudioHeader($fd, $offset, &$ThisFileInfo, $recursivesearch = true, $ScanAsCBR = false, $FastMPEGheaderScan = false)
{
static $MPEGaudioVersionLookup;
static $MPEGaudioLayerLookup;
static $MPEGaudioBitrateLookup;
static $MPEGaudioFrequencyLookup;
static $MPEGaudioChannelModeLookup;
static $MPEGaudioModeExtensionLookup;
static $MPEGaudioEmphasisLookup;
if (empty($MPEGaudioVersionLookup)) {
$MPEGaudioVersionLookup = 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, 192);
// 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));
}
}
$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']];
// For Layer II there are some combinations of bitrate and mode which are not allowed.
if (!$FastMPEGheaderScan && $ThisFileInfo['mpeg']['audio']['layer'] == 'II') {
//$ThisFileInfo['fileformat'] = 'mp2';
$ThisFileInfo['audio']['dataformat'] = 'mp2';
switch ($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['mpeg']['audio']['bitrate'] != 'free') {
if ($ThisFileInfo['mpeg']['audio']['version'] == '1') {
if ($ThisFileInfo['mpeg']['audio']['layer'] == 'I') {
$FrameLengthCoefficient = 48;
$FrameLengthPadding = $ThisFileInfo['mpeg']['audio']['padding'] ? 4 : 0;
// For Layer I slot is 32 bits long, for Layer II and Layer III slot is 8 bits long.
} else {
// Layer II / III
$FrameLengthCoefficient = 144;
$FrameLengthPadding = $ThisFileInfo['mpeg']['audio']['padding'] ? 1 : 0;
// For Layer I slot is 32 bits long, for Layer II and Layer III slot is 8 bits long.
}
} else {
// MPEG-2 / MPEG-2.5
if ($ThisFileInfo['mpeg']['audio']['layer'] == 'I') {
$FrameLengthCoefficient = 24;
$FrameLengthPadding = $ThisFileInfo['mpeg']['audio']['padding'] ? 4 : 0;
// For Layer I slot is 32 bits long, for Layer II and Layer III slot is 8 bits long.
} else {
// Layer II / III
$FrameLengthCoefficient = 72;
$FrameLengthPadding = $ThisFileInfo['mpeg']['audio']['padding'] ? 1 : 0;
// For Layer I slot is 32 bits long, for Layer II and Layer III slot is 8 bits long.
}
}
// FrameLengthInBytes = ((Coefficient * BitRate) / SampleRate) + Padding
// http://66.96.216.160/cgi-bin/YaBB.pl?board=c&action=display&num=1018474068
// -> [Finding the next frame synch] on www.r3mix.net forums if the above link goes dead
if ($ThisFileInfo['audio']['sample_rate'] > 0) {
$ThisFileInfo['mpeg']['audio']['framelength'] = (int) floor($FrameLengthCoefficient * 1000 * $ThisFileInfo['mpeg']['audio']['bitrate'] / $ThisFileInfo['audio']['sample_rate']) + $FrameLengthPadding;
}
}
$ThisFileInfo['audio']['bitrate'] = 1000 * $ThisFileInfo['mpeg']['audio']['bitrate'];
if (isset($ThisFileInfo['mpeg']['audio']['framelength'])) {
$nextframetestoffset = $offset + $ThisFileInfo['mpeg']['audio']['framelength'];
} else {
$ThisFileInfo['error'] .= "\n" . 'Frame at offset(' . $offset . ') is has an invalid frame length.';
return false;
}
////////////////////////////////////////////////////////////////////////////////////
// Variable-bitrate headers
if (substr($headerstring, 4 + 32, 4) == 'VBRI') {
// Fraunhofer VBR header is hardcoded 'VBRI' at offset 0x24 (36)
// specs taken from http://minnie.tuhs.org/pipermail/mp3encoder/2001-January/001800.html
$ThisFileInfo['mpeg']['audio']['bitrate_mode'] = 'vbr';
$ThisFileInfo['mpeg']['audio']['VBR_method'] = 'Fraunhofer';
$ThisFileInfo['audio']['codec'] = 'Fraunhofer';
$SideInfoData = substr($headerstring, 4 + 2, 32);
$FraunhoferVBROffset = 4 + 32 + strlen('VBRI');
$Fraunhofer_EncoderVersion = substr($headerstring, $FraunhoferVBROffset, 2);
$FraunhoferVBROffset += 2;
$ThisFileInfo['mpeg']['audio']['VBR_encoder_version'] = BigEndian2Int($Fraunhofer_EncoderVersion);
$Fraunhofer_EncoderDelay = substr($headerstring, $FraunhoferVBROffset, 2);
$FraunhoferVBROffset += 2;
$ThisFileInfo['mpeg']['audio']['VBR_encoder_delay'] = BigEndian2Int($Fraunhofer_EncoderDelay);
$Fraunhofer_quality = substr($headerstring, $FraunhoferVBROffset, 2);
$FraunhoferVBROffset += 2;
$ThisFileInfo['mpeg']['audio']['VBR_quality'] = BigEndian2Int($Fraunhofer_quality);
$Fraunhofer_Bytes = substr($headerstring, $FraunhoferVBROffset, 4);
$FraunhoferVBROffset += 4;
$ThisFileInfo['mpeg']['audio']['VBR_bytes'] = BigEndian2Int($Fraunhofer_Bytes);
$Fraunhofer_Frames = substr($headerstring, $FraunhoferVBROffset, 4);
$FraunhoferVBROffset += 4;
$ThisFileInfo['mpeg']['audio']['VBR_frames'] = BigEndian2Int($Fraunhofer_Frames);
$Fraunhofer_SeekOffsets = substr($headerstring, $FraunhoferVBROffset, 2);
$FraunhoferVBROffset += 2;
$ThisFileInfo['mpeg']['audio']['VBR_seek_offsets'] = BigEndian2Int($Fraunhofer_SeekOffsets);
$FraunhoferVBROffset += 4;
// hardcoded $00 $01 $00 $02 - purpose unknown
$Fraunhofer_OffsetStride = substr($headerstring, $FraunhoferVBROffset, 2);
$FraunhoferVBROffset += 2;
$ThisFileInfo['mpeg']['audio']['VBR_seek_offsets_stride'] = BigEndian2Int($Fraunhofer_OffsetStride);
$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';
$XingVBROffset = $VBRidOffset + strlen('Xing');
$ThisFileInfo['mpeg']['audio']['xing_flags_raw'] = substr($headerstring, $XingVBROffset, 4);
$XingVBROffset += 4;
$XingHeader_byte4 = BigEndian2Bin(substr($ThisFileInfo['mpeg']['audio']['xing_flags_raw'], 3, 1));
$ThisFileInfo['mpeg']['audio']['xing_flags']['frames'] = (bool) $XingHeader_byte4[4];
$ThisFileInfo['mpeg']['audio']['xing_flags']['bytes'] = (bool) $XingHeader_byte4[5];
$ThisFileInfo['mpeg']['audio']['xing_flags']['toc'] = (bool) $XingHeader_byte4[6];
$ThisFileInfo['mpeg']['audio']['xing_flags']['vbr_scale'] = (bool) $XingHeader_byte4[7];
if ($ThisFileInfo['mpeg']['audio']['xing_flags']['frames']) {
$ThisFileInfo['mpeg']['audio']['VBR_frames'] = BigEndian2Int(substr($headerstring, $XingVBROffset, 4));
$XingVBROffset += 4;
}
if ($ThisFileInfo['mpeg']['audio']['xing_flags']['bytes']) {
$ThisFileInfo['mpeg']['audio']['VBR_bytes'] = BigEndian2Int(substr($headerstring, $XingVBROffset, 4));
$XingVBROffset += 4;
}
if ($ThisFileInfo['mpeg']['audio']['xing_flags']['toc']) {
$LAMEtocData = substr($headerstring, $XingVBROffset, 100);
$XingVBROffset += 100;
for ($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, $XingVBROffset, 4));
$XingVBROffset += 4;
}
if (substr($headerstring, $XingVBROffset, 4) == 'LAME') {
$ThisFileInfo['mpeg']['audio']['LAME']['short_version'] = substr($headerstring, $XingVBROffset, 9);
$XingVBROffset += 9;
$LAMEtagRevisionVBRmethod = BigEndian2Int(substr($headerstring, $XingVBROffset, 1));
$XingVBROffset += 1;
$ThisFileInfo['mpeg']['audio']['LAME']['tag_revision'] = ($LAMEtagRevisionVBRmethod & 0xf0) >> 4;
$ThisFileInfo['mpeg']['audio']['LAME']['vbr_method_raw'] = $LAMEtagRevisionVBRmethod & 0xf;
$ThisFileInfo['mpeg']['audio']['LAME']['vbr_method'] = LAMEvbrMethodLookup($ThisFileInfo['mpeg']['audio']['LAME']['vbr_method_raw']);
$ThisFileInfo['mpeg']['audio']['LAME']['lowpass_frequency'] = 100 * BigEndian2Int(substr($headerstring, $XingVBROffset, 1));
$XingVBROffset += 1;
// http://privatewww.essex.ac.uk/~djmrob/replaygain/rg_data_format.html
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['peak_amplitude'] = BigEndian2Float(substr($headerstring, $XingVBROffset, 4));
$XingVBROffset += 4;
$RadioReplayGainRaw = BigEndian2Int(substr($headerstring, $XingVBROffset, 2));
$XingVBROffset += 4;
$ReplayGainID = ($RadioReplayGainRaw & 0xe000) >> 13;
$ReplayGainNameKey = '';
switch ($ReplayGainID) {
case 1:
$ReplayGainNameKey = 'radio';
break;
case 2:
$ReplayGainNameKey = 'audiophile';
break;
case 0:
// replay gain not set
// replay gain not set
default:
// reserved
break;
}
if ($ReplayGainNameKey) {
require_once GETID3_INCLUDEPATH . 'getid3.rgad.php';
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['raw']['name'] = ($RadioReplayGainRaw & 0xe000) >> 13;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['raw']['originator'] = ($RadioReplayGainRaw & 0x1c00) >> 10;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['raw']['sign_bit'] = ($RadioReplayGainRaw & 0x200) >> 9;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['raw']['gain_adjust'] = $RadioReplayGainRaw & 0x1ff;
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['name'] = RGADnameLookup($ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['raw']['name']);
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['originator'] = RGADoriginatorLookup($ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['raw']['originator']);
$ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['gain_db'] = RGADadjustmentLookup($ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['raw']['gain_adjust'], $ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['raw']['sign_bit']);
$ThisFileInfo['replay_gain']["{$ReplayGainNameKey}"]['peak'] = $ThisFileInfo['mpeg']['audio']['LAME']['RGAD']['peak_amplitude'];
$ThisFileInfo['replay_gain']["{$ReplayGainNameKey}"]['originator'] = $ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['originator'];
$ThisFileInfo['replay_gain']["{$ReplayGainNameKey}"]['adjustment'] = $ThisFileInfo['mpeg']['audio']['LAME']['RGAD']["{$ReplayGainNameKey}"]['gain_db'];
}
$EncodingFlagsATHtype = BigEndian2Int(substr($headerstring, $XingVBROffset, 1));
$XingVBROffset += 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 & 0xf;
$ABRbitrateMinBitrate = BigEndian2Int(substr($headerstring, $XingVBROffset, 1));
$XingVBROffset += 1;
if ($ThisFileInfo['mpeg']['audio']['LAME']['vbr_method_raw'] == 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;
}
$EncoderDelays = BigEndian2Int(substr($headerstring, $XingVBROffset, 3));
$XingVBROffset += 3;
$ThisFileInfo['mpeg']['audio']['LAME']['encoder_delay'] = ($EncoderDelays & 0xfff000) >> 12;
$ThisFileInfo['mpeg']['audio']['LAME']['end_padding'] = $EncoderDelays & 0xfff;
$MiscByte = BigEndian2Int(substr($headerstring, $XingVBROffset, 1));
$XingVBROffset += 1;
$ThisFileInfo['mpeg']['audio']['LAME']['noise_shaping_raw'] = $EncodingFlagsATHtype & 0x3;
$ThisFileInfo['mpeg']['audio']['LAME']['stereo_mode_raw'] = ($EncodingFlagsATHtype & 0x1c) >> 2;
$ThisFileInfo['mpeg']['audio']['LAME']['not_optimal_quality_raw'] = ($EncodingFlagsATHtype & 0x20) >> 5;
$ThisFileInfo['mpeg']['audio']['LAME']['source_sample_freq_raw'] = ($EncodingFlagsATHtype & 0xc0) >> 6;
$ThisFileInfo['mpeg']['audio']['LAME']['noise_shaping'] = $ThisFileInfo['mpeg']['audio']['LAME']['noise_shaping_raw'];
$ThisFileInfo['mpeg']['audio']['LAME']['stereo_mode'] = LAMEmiscStereoModeLookup($ThisFileInfo['mpeg']['audio']['LAME']['stereo_mode_raw']);
$ThisFileInfo['mpeg']['audio']['LAME']['not_optimal_quality'] = (bool) $ThisFileInfo['mpeg']['audio']['LAME']['not_optimal_quality_raw'];
$ThisFileInfo['mpeg']['audio']['LAME']['source_sample_freq'] = LAMEmiscSourceSampleFrequencyLookup($ThisFileInfo['mpeg']['audio']['LAME']['source_sample_freq_raw']);
$ThisFileInfo['mpeg']['audio']['LAME']['mp3_gain_raw'] = BigEndian2Int(substr($headerstring, $XingVBROffset, 1), false, true);
$XingVBROffset += 1;
$ThisFileInfo['mpeg']['audio']['LAME']['mp3_gain_db'] = 1.5 * $ThisFileInfo['mpeg']['audio']['LAME']['mp3_gain_raw'];
$ThisFileInfo['mpeg']['audio']['LAME']['mp3_gain_factor'] = pow(2, $ThisFileInfo['mpeg']['audio']['LAME']['mp3_gain_db'] / 6);
$PresetSurroundBytes = BigEndian2Int(substr($headerstring, $XingVBROffset, 2));
//$Reserved = ($PresetSurroundBytes & 0xC000);
$ThisFileInfo['mpeg']['audio']['LAME']['surround_info_id'] = $PresetSurroundBytes & 0x3800;
$ThisFileInfo['mpeg']['audio']['LAME']['surround_info'] = LAMEsurroundInfoLookup($ThisFileInfo['mpeg']['audio']['LAME']['surround_info_id']);
$ThisFileInfo['mpeg']['audio']['LAME']['preset_used_id'] = $PresetSurroundBytes & 0x7ff;
$XingVBROffset += 2;
$ThisFileInfo['mpeg']['audio']['LAME']['audio_bytes'] = BigEndian2Int(substr($headerstring, $XingVBROffset, 4));
$XingVBROffset += 4;
if ($ThisFileInfo['mpeg']['audio']['LAME']['audio_bytes'] > $ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) {
$ThisFileInfo['warning'] .= "\n" . 'Probable truncated file: expecting ' . $ThisFileInfo['mpeg']['audio']['LAME']['audio_bytes'] . ' bytes of audio data, only found ' . ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']);
}
$ThisFileInfo['mpeg']['audio']['LAME']['music_crc'] = BigEndian2Int(substr($headerstring, $XingVBROffset, 2));
$XingVBROffset += 2;
$ThisFileInfo['mpeg']['audio']['LAME']['lame_tag_crc'] = BigEndian2Int(substr($headerstring, $XingVBROffset, 2));
$XingVBROffset += 2;
// LAME CBR
if ($ThisFileInfo['mpeg']['audio']['LAME']['vbr_method_raw'] == 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') {
$ThisFileInfo['warning'] .= "\n" . 'VBR file with no VBR header. Bitrate values calculated from actual frame bitrates.';
}
}
}
}
if ($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;
}