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/getid3/module.audio.mp3.php

https://bitbucket.org/holyfield/getid3
PHP | 2010 lines | 1430 code | 284 blank | 296 comment | 399 complexity | 4dfcc43a135d5600a396526410f4d65d MD5 | raw file
   1<?php
   2/////////////////////////////////////////////////////////////////
   3/// getID3() by James Heinrich <info@getid3.org>               //
   4//  available at http://getid3.sourceforge.net                 //
   5//            or http://www.getid3.org                         //
   6/////////////////////////////////////////////////////////////////
   7// See readme.txt for more details                             //
   8/////////////////////////////////////////////////////////////////
   9//                                                             //
  10// module.audio.mp3.php                                        //
  11// module for analyzing MP3 files                              //
  12// dependencies: NONE                                          //
  13//                                                            ///
  14/////////////////////////////////////////////////////////////////
  15
  16
  17// number of frames to scan to determine if MPEG-audio sequence is valid
  18// Lower this number to 5-20 for faster scanning
  19// Increase this number to 50+ for most accurate detection of valid VBR/CBR
  20// mpeg-audio streams
  21define('GETID3_MP3_VALID_CHECK_FRAMES', 35);
  22
  23
  24class getid3_mp3 extends getid3_handler
  25{
  26
  27	var $allow_bruteforce = false; // forces getID3() to scan the file byte-by-byte and log all the valid audio frame headers - extremely slow, unrecommended, but may provide data from otherwise-unusuable files
  28
  29	function Analyze() {
  30		$info = &$this->getid3->info;
  31
  32		$initialOffset = $info['avdataoffset'];
  33
  34		if (!$this->getOnlyMPEGaudioInfo($info['avdataoffset'])) {
  35			if ($this->allow_bruteforce) {
  36				$info['error'][] = 'Rescanning file in BruteForce mode';
  37				$this->getOnlyMPEGaudioInfoBruteForce($this->getid3->fp, $info);
  38			}
  39		}
  40
  41
  42		if (isset($info['mpeg']['audio']['bitrate_mode'])) {
  43			$info['audio']['bitrate_mode'] = strtolower($info['mpeg']['audio']['bitrate_mode']);
  44		}
  45
  46		if (((isset($info['id3v2']['headerlength']) && ($info['avdataoffset'] > $info['id3v2']['headerlength'])) || (!isset($info['id3v2']) && ($info['avdataoffset'] > 0) && ($info['avdataoffset'] != $initialOffset)))) {
  47
  48			$synchoffsetwarning = 'Unknown data before synch ';
  49			if (isset($info['id3v2']['headerlength'])) {
  50				$synchoffsetwarning .= '(ID3v2 header ends at '.$info['id3v2']['headerlength'].', then '.($info['avdataoffset'] - $info['id3v2']['headerlength']).' bytes garbage, ';
  51			} elseif ($initialOffset > 0) {
  52				$synchoffsetwarning .= '(should be at '.$initialOffset.', ';
  53			} else {
  54				$synchoffsetwarning .= '(should be at beginning of file, ';
  55			}
  56			$synchoffsetwarning .= 'synch detected at '.$info['avdataoffset'].')';
  57			if (isset($info['audio']['bitrate_mode']) && ($info['audio']['bitrate_mode'] == 'cbr')) {
  58
  59				if (!empty($info['id3v2']['headerlength']) && (($info['avdataoffset'] - $info['id3v2']['headerlength']) == $info['mpeg']['audio']['framelength'])) {
  60
  61					$synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90-3.92) DLL in CBR mode.';
  62					$info['audio']['codec'] = 'LAME';
  63					$CurrentDataLAMEversionString = 'LAME3.';
  64
  65				} elseif (empty($info['id3v2']['headerlength']) && ($info['avdataoffset'] == $info['mpeg']['audio']['framelength'])) {
  66
  67					$synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90 - 3.92) DLL in CBR mode.';
  68					$info['audio']['codec'] = 'LAME';
  69					$CurrentDataLAMEversionString = 'LAME3.';
  70
  71				}
  72
  73			}
  74			$info['warning'][] = $synchoffsetwarning;
  75
  76		}
  77
  78		if (isset($info['mpeg']['audio']['LAME'])) {
  79			$info['audio']['codec'] = 'LAME';
  80			if (!empty($info['mpeg']['audio']['LAME']['long_version'])) {
  81				$info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['long_version'], "\x00");
  82			} elseif (!empty($info['mpeg']['audio']['LAME']['short_version'])) {
  83				$info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['short_version'], "\x00");
  84			}
  85		}
  86
  87		$CurrentDataLAMEversionString = (!empty($CurrentDataLAMEversionString) ? $CurrentDataLAMEversionString : (isset($info['audio']['encoder']) ? $info['audio']['encoder'] : ''));
  88		if (!empty($CurrentDataLAMEversionString) && (substr($CurrentDataLAMEversionString, 0, 6) == 'LAME3.') && !preg_match('[0-9\)]', substr($CurrentDataLAMEversionString, -1))) {
  89			// a version number of LAME that does not end with a number like "LAME3.92"
  90			// or with a closing parenthesis like "LAME3.88 (alpha)"
  91			// or a version of LAME with the LAMEtag-not-filled-in-DLL-mode bug (3.90-3.92)
  92
  93			// not sure what the actual last frame length will be, but will be less than or equal to 1441
  94			$PossiblyLongerLAMEversion_FrameLength = 1441;
  95
  96			// Not sure what version of LAME this is - look in padding of last frame for longer version string
  97			$PossibleLAMEversionStringOffset = $info['avdataend'] - $PossiblyLongerLAMEversion_FrameLength;
  98			fseek($this->getid3->fp, $PossibleLAMEversionStringOffset);
  99			$PossiblyLongerLAMEversion_Data = fread($this->getid3->fp, $PossiblyLongerLAMEversion_FrameLength);
 100			switch (substr($CurrentDataLAMEversionString, -1)) {
 101				case 'a':
 102				case 'b':
 103					// "LAME3.94a" will have a longer version string of "LAME3.94 (alpha)" for example
 104					// need to trim off "a" to match longer string
 105					$CurrentDataLAMEversionString = substr($CurrentDataLAMEversionString, 0, -1);
 106					break;
 107			}
 108			if (($PossiblyLongerLAMEversion_String = strstr($PossiblyLongerLAMEversion_Data, $CurrentDataLAMEversionString)) !== false) {
 109				if (substr($PossiblyLongerLAMEversion_String, 0, strlen($CurrentDataLAMEversionString)) == $CurrentDataLAMEversionString) {
 110					$PossiblyLongerLAMEversion_NewString = substr($PossiblyLongerLAMEversion_String, 0, strspn($PossiblyLongerLAMEversion_String, 'LAME0123456789., (abcdefghijklmnopqrstuvwxyzJFSOND)')); //"LAME3.90.3"  "LAME3.87 (beta 1, Sep 27 2000)" "LAME3.88 (beta)"
 111					if (empty($info['audio']['encoder']) || (strlen($PossiblyLongerLAMEversion_NewString) > strlen($info['audio']['encoder']))) {
 112						$info['audio']['encoder'] = $PossiblyLongerLAMEversion_NewString;
 113					}
 114				}
 115			}
 116		}
 117		if (!empty($info['audio']['encoder'])) {
 118			$info['audio']['encoder'] = rtrim($info['audio']['encoder'], "\x00 ");
 119		}
 120
 121		switch (isset($info['mpeg']['audio']['layer']) ? $info['mpeg']['audio']['layer'] : '') {
 122			case 1:
 123			case 2:
 124				$info['audio']['dataformat'] = 'mp'.$info['mpeg']['audio']['layer'];
 125				break;
 126		}
 127		if (isset($info['fileformat']) && ($info['fileformat'] == 'mp3')) {
 128			switch ($info['audio']['dataformat']) {
 129				case 'mp1':
 130				case 'mp2':
 131				case 'mp3':
 132					$info['fileformat'] = $info['audio']['dataformat'];
 133					break;
 134
 135				default:
 136					$info['warning'][] = 'Expecting [audio][dataformat] to be mp1/mp2/mp3 when fileformat == mp3, [audio][dataformat] actually "'.$info['audio']['dataformat'].'"';
 137					break;
 138			}
 139		}
 140
 141		if (empty($info['fileformat'])) {
 142			unset($info['fileformat']);
 143			unset($info['audio']['bitrate_mode']);
 144			unset($info['avdataoffset']);
 145			unset($info['avdataend']);
 146			return false;
 147		}
 148
 149		$info['mime_type']         = 'audio/mpeg';
 150		$info['audio']['lossless'] = false;
 151
 152		// Calculate playtime
 153		if (!isset($info['playtime_seconds']) && isset($info['audio']['bitrate']) && ($info['audio']['bitrate'] > 0)) {
 154			$info['playtime_seconds'] = ($info['avdataend'] - $info['avdataoffset']) * 8 / $info['audio']['bitrate'];
 155		}
 156
 157		$info['audio']['encoder_options'] = $this->GuessEncoderOptions();
 158
 159		return true;
 160	}
 161
 162
 163	function GuessEncoderOptions() {
 164		// shortcuts
 165		$info = &$this->getid3->info;
 166		if (!empty($info['mpeg']['audio'])) {
 167			$thisfile_mpeg_audio = &$info['mpeg']['audio'];
 168			if (!empty($thisfile_mpeg_audio['LAME'])) {
 169				$thisfile_mpeg_audio_lame = &$thisfile_mpeg_audio['LAME'];
 170			}
 171		}
 172
 173		$encoder_options = '';
 174		static $NamedPresetBitrates = array(16, 24, 40, 56, 112, 128, 160, 192, 256);
 175
 176		if (isset($thisfile_mpeg_audio['VBR_method']) && ($thisfile_mpeg_audio['VBR_method'] == 'Fraunhofer') && !empty($thisfile_mpeg_audio['VBR_quality'])) {
 177
 178			$encoder_options = 'VBR q'.$thisfile_mpeg_audio['VBR_quality'];
 179
 180		} elseif (!empty($thisfile_mpeg_audio_lame['preset_used']) && (!in_array($thisfile_mpeg_audio_lame['preset_used_id'], $NamedPresetBitrates))) {
 181
 182			$encoder_options = $thisfile_mpeg_audio_lame['preset_used'];
 183
 184		} elseif (!empty($thisfile_mpeg_audio_lame['vbr_quality'])) {
 185
 186			static $KnownEncoderValues = array();
 187			if (empty($KnownEncoderValues)) {
 188
 189				//$KnownEncoderValues[abrbitrate_minbitrate][vbr_quality][raw_vbr_method][raw_noise_shaping][raw_stereo_mode][ath_type][lowpass_frequency] = 'preset name';
 190				$KnownEncoderValues[0xFF][58][1][1][3][2][20500] = '--alt-preset insane';        // 3.90,   3.90.1, 3.92
 191				$KnownEncoderValues[0xFF][58][1][1][3][2][20600] = '--alt-preset insane';        // 3.90.2, 3.90.3, 3.91
 192				$KnownEncoderValues[0xFF][57][1][1][3][4][20500] = '--alt-preset insane';        // 3.94,   3.95
 193				$KnownEncoderValues['**'][78][3][2][3][2][19500] = '--alt-preset extreme';       // 3.90,   3.90.1, 3.92
 194				$KnownEncoderValues['**'][78][3][2][3][2][19600] = '--alt-preset extreme';       // 3.90.2, 3.91
 195				$KnownEncoderValues['**'][78][3][1][3][2][19600] = '--alt-preset extreme';       // 3.90.3
 196				$KnownEncoderValues['**'][78][4][2][3][2][19500] = '--alt-preset fast extreme';  // 3.90,   3.90.1, 3.92
 197				$KnownEncoderValues['**'][78][4][2][3][2][19600] = '--alt-preset fast extreme';  // 3.90.2, 3.90.3, 3.91
 198				$KnownEncoderValues['**'][78][3][2][3][4][19000] = '--alt-preset standard';      // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
 199				$KnownEncoderValues['**'][78][3][1][3][4][19000] = '--alt-preset standard';      // 3.90.3
 200				$KnownEncoderValues['**'][78][4][2][3][4][19000] = '--alt-preset fast standard'; // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
 201				$KnownEncoderValues['**'][78][4][1][3][4][19000] = '--alt-preset fast standard'; // 3.90.3
 202				$KnownEncoderValues['**'][88][4][1][3][3][19500] = '--r3mix';                    // 3.90,   3.90.1, 3.92
 203				$KnownEncoderValues['**'][88][4][1][3][3][19600] = '--r3mix';                    // 3.90.2, 3.90.3, 3.91
 204				$KnownEncoderValues['**'][67][4][1][3][4][18000] = '--r3mix';                    // 3.94,   3.95
 205				$KnownEncoderValues['**'][68][3][2][3][4][18000] = '--alt-preset medium';        // 3.90.3
 206				$KnownEncoderValues['**'][68][4][2][3][4][18000] = '--alt-preset fast medium';   // 3.90.3
 207
 208				$KnownEncoderValues[0xFF][99][1][1][1][2][0]     = '--preset studio';            // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
 209				$KnownEncoderValues[0xFF][58][2][1][3][2][20600] = '--preset studio';            // 3.90.3, 3.93.1
 210				$KnownEncoderValues[0xFF][58][2][1][3][2][20500] = '--preset studio';            // 3.93
 211				$KnownEncoderValues[0xFF][57][2][1][3][4][20500] = '--preset studio';            // 3.94,   3.95
 212				$KnownEncoderValues[0xC0][88][1][1][1][2][0]     = '--preset cd';                // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
 213				$KnownEncoderValues[0xC0][58][2][2][3][2][19600] = '--preset cd';                // 3.90.3, 3.93.1
 214				$KnownEncoderValues[0xC0][58][2][2][3][2][19500] = '--preset cd';                // 3.93
 215				$KnownEncoderValues[0xC0][57][2][1][3][4][19500] = '--preset cd';                // 3.94,   3.95
 216				$KnownEncoderValues[0xA0][78][1][1][3][2][18000] = '--preset hifi';              // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
 217				$KnownEncoderValues[0xA0][58][2][2][3][2][18000] = '--preset hifi';              // 3.90.3, 3.93,   3.93.1
 218				$KnownEncoderValues[0xA0][57][2][1][3][4][18000] = '--preset hifi';              // 3.94,   3.95
 219				$KnownEncoderValues[0x80][67][1][1][3][2][18000] = '--preset tape';              // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
 220				$KnownEncoderValues[0x80][67][1][1][3][2][15000] = '--preset radio';             // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
 221				$KnownEncoderValues[0x70][67][1][1][3][2][15000] = '--preset fm';                // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
 222				$KnownEncoderValues[0x70][58][2][2][3][2][16000] = '--preset tape/radio/fm';     // 3.90.3, 3.93,   3.93.1
 223				$KnownEncoderValues[0x70][57][2][1][3][4][16000] = '--preset tape/radio/fm';     // 3.94,   3.95
 224				$KnownEncoderValues[0x38][58][2][2][0][2][10000] = '--preset voice';             // 3.90.3, 3.93,   3.93.1
 225				$KnownEncoderValues[0x38][57][2][1][0][4][15000] = '--preset voice';             // 3.94,   3.95
 226				$KnownEncoderValues[0x38][57][2][1][0][4][16000] = '--preset voice';             // 3.94a14
 227				$KnownEncoderValues[0x28][65][1][1][0][2][7500]  = '--preset mw-us';             // 3.90,   3.90.1, 3.92
 228				$KnownEncoderValues[0x28][65][1][1][0][2][7600]  = '--preset mw-us';             // 3.90.2, 3.91
 229				$KnownEncoderValues[0x28][58][2][2][0][2][7000]  = '--preset mw-us';             // 3.90.3, 3.93,   3.93.1
 230				$KnownEncoderValues[0x28][57][2][1][0][4][10500] = '--preset mw-us';             // 3.94,   3.95
 231				$KnownEncoderValues[0x28][57][2][1][0][4][11200] = '--preset mw-us';             // 3.94a14
 232				$KnownEncoderValues[0x28][57][2][1][0][4][8800]  = '--preset mw-us';             // 3.94a15
 233				$KnownEncoderValues[0x18][58][2][2][0][2][4000]  = '--preset phon+/lw/mw-eu/sw'; // 3.90.3, 3.93.1
 234				$KnownEncoderValues[0x18][58][2][2][0][2][3900]  = '--preset phon+/lw/mw-eu/sw'; // 3.93
 235				$KnownEncoderValues[0x18][57][2][1][0][4][5900]  = '--preset phon+/lw/mw-eu/sw'; // 3.94,   3.95
 236				$KnownEncoderValues[0x18][57][2][1][0][4][6200]  = '--preset phon+/lw/mw-eu/sw'; // 3.94a14
 237				$KnownEncoderValues[0x18][57][2][1][0][4][3200]  = '--preset phon+/lw/mw-eu/sw'; // 3.94a15
 238				$KnownEncoderValues[0x10][58][2][2][0][2][3800]  = '--preset phone';             // 3.90.3, 3.93.1
 239				$KnownEncoderValues[0x10][58][2][2][0][2][3700]  = '--preset phone';             // 3.93
 240				$KnownEncoderValues[0x10][57][2][1][0][4][5600]  = '--preset phone';             // 3.94,   3.95
 241			}
 242
 243			if (isset($KnownEncoderValues[$thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate']][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']])) {
 244
 245				$encoder_options = $KnownEncoderValues[$thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate']][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']];
 246
 247			} elseif (isset($KnownEncoderValues['**'][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']])) {
 248
 249				$encoder_options = $KnownEncoderValues['**'][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']];
 250
 251			} elseif ($info['audio']['bitrate_mode'] == 'vbr') {
 252
 253				// http://gabriel.mp3-tech.org/mp3infotag.html
 254				// int    Quality = (100 - 10 * gfp->VBR_q - gfp->quality)h
 255
 256
 257				$LAME_V_value = 10 - ceil($thisfile_mpeg_audio_lame['vbr_quality'] / 10);
 258				$LAME_q_value = 100 - $thisfile_mpeg_audio_lame['vbr_quality'] - ($LAME_V_value * 10);
 259				$encoder_options = '-V'.$LAME_V_value.' -q'.$LAME_q_value;
 260
 261			} elseif ($info['audio']['bitrate_mode'] == 'cbr') {
 262
 263				$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
 264
 265			} else {
 266
 267				$encoder_options = strtoupper($info['audio']['bitrate_mode']);
 268
 269			}
 270
 271		} elseif (!empty($thisfile_mpeg_audio_lame['bitrate_abr'])) {
 272
 273			$encoder_options = 'ABR'.$thisfile_mpeg_audio_lame['bitrate_abr'];
 274
 275		} elseif (!empty($info['audio']['bitrate'])) {
 276
 277			if ($info['audio']['bitrate_mode'] == 'cbr') {
 278				$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
 279			} else {
 280				$encoder_options = strtoupper($info['audio']['bitrate_mode']);
 281			}
 282
 283		}
 284		if (!empty($thisfile_mpeg_audio_lame['bitrate_min'])) {
 285			$encoder_options .= ' -b'.$thisfile_mpeg_audio_lame['bitrate_min'];
 286		}
 287
 288		if (!empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev']) || !empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_next'])) {
 289			$encoder_options .= ' --nogap';
 290		}
 291
 292		if (!empty($thisfile_mpeg_audio_lame['lowpass_frequency'])) {
 293			$ExplodedOptions = explode(' ', $encoder_options, 4);
 294			if ($ExplodedOptions[0] == '--r3mix') {
 295				$ExplodedOptions[1] = 'r3mix';
 296			}
 297			switch ($ExplodedOptions[0]) {
 298				case '--preset':
 299				case '--alt-preset':
 300				case '--r3mix':
 301					if ($ExplodedOptions[1] == 'fast') {
 302						$ExplodedOptions[1] .= ' '.$ExplodedOptions[2];
 303					}
 304					switch ($ExplodedOptions[1]) {
 305						case 'portable':
 306						case 'medium':
 307						case 'standard':
 308						case 'extreme':
 309						case 'insane':
 310						case 'fast portable':
 311						case 'fast medium':
 312						case 'fast standard':
 313						case 'fast extreme':
 314						case 'fast insane':
 315						case 'r3mix':
 316							static $ExpectedLowpass = array(
 317									'insane|20500'        => 20500,
 318									'insane|20600'        => 20600,  // 3.90.2, 3.90.3, 3.91
 319									'medium|18000'        => 18000,
 320									'fast medium|18000'   => 18000,
 321									'extreme|19500'       => 19500,  // 3.90,   3.90.1, 3.92, 3.95
 322									'extreme|19600'       => 19600,  // 3.90.2, 3.90.3, 3.91, 3.93.1
 323									'fast extreme|19500'  => 19500,  // 3.90,   3.90.1, 3.92, 3.95
 324									'fast extreme|19600'  => 19600,  // 3.90.2, 3.90.3, 3.91, 3.93.1
 325									'standard|19000'      => 19000,
 326									'fast standard|19000' => 19000,
 327									'r3mix|19500'         => 19500,  // 3.90,   3.90.1, 3.92
 328									'r3mix|19600'         => 19600,  // 3.90.2, 3.90.3, 3.91
 329									'r3mix|18000'         => 18000,  // 3.94,   3.95
 330								);
 331							if (!isset($ExpectedLowpass[$ExplodedOptions[1].'|'.$thisfile_mpeg_audio_lame['lowpass_frequency']]) && ($thisfile_mpeg_audio_lame['lowpass_frequency'] < 22050) && (round($thisfile_mpeg_audio_lame['lowpass_frequency'] / 1000) < round($thisfile_mpeg_audio['sample_rate'] / 2000))) {
 332								$encoder_options .= ' --lowpass '.$thisfile_mpeg_audio_lame['lowpass_frequency'];
 333							}
 334							break;
 335
 336						default:
 337							break;
 338					}
 339					break;
 340			}
 341		}
 342
 343		if (isset($thisfile_mpeg_audio_lame['raw']['source_sample_freq'])) {
 344			if (($thisfile_mpeg_audio['sample_rate'] == 44100) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 1)) {
 345				$encoder_options .= ' --resample 44100';
 346			} elseif (($thisfile_mpeg_audio['sample_rate'] == 48000) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 2)) {
 347				$encoder_options .= ' --resample 48000';
 348			} elseif ($thisfile_mpeg_audio['sample_rate'] < 44100) {
 349				switch ($thisfile_mpeg_audio_lame['raw']['source_sample_freq']) {
 350					case 0: // <= 32000
 351						// may or may not be same as source frequency - ignore
 352						break;
 353					case 1: // 44100
 354					case 2: // 48000
 355					case 3: // 48000+
 356						$ExplodedOptions = explode(' ', $encoder_options, 4);
 357						switch ($ExplodedOptions[0]) {
 358							case '--preset':
 359							case '--alt-preset':
 360								switch ($ExplodedOptions[1]) {
 361									case 'fast':
 362									case 'portable':
 363									case 'medium':
 364									case 'standard':
 365									case 'extreme':
 366									case 'insane':
 367										$encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
 368										break;
 369
 370									default:
 371										static $ExpectedResampledRate = array(
 372												'phon+/lw/mw-eu/sw|16000' => 16000,
 373												'mw-us|24000'             => 24000, // 3.95
 374												'mw-us|32000'             => 32000, // 3.93
 375												'mw-us|16000'             => 16000, // 3.92
 376												'phone|16000'             => 16000,
 377												'phone|11025'             => 11025, // 3.94a15
 378												'radio|32000'             => 32000, // 3.94a15
 379												'fm/radio|32000'          => 32000, // 3.92
 380												'fm|32000'                => 32000, // 3.90
 381												'voice|32000'             => 32000);
 382										if (!isset($ExpectedResampledRate[$ExplodedOptions[1].'|'.$thisfile_mpeg_audio['sample_rate']])) {
 383											$encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
 384										}
 385										break;
 386								}
 387								break;
 388
 389							case '--r3mix':
 390							default:
 391								$encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
 392								break;
 393						}
 394						break;
 395				}
 396			}
 397		}
 398		if (empty($encoder_options) && !empty($info['audio']['bitrate']) && !empty($info['audio']['bitrate_mode'])) {
 399			//$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
 400			$encoder_options = strtoupper($info['audio']['bitrate_mode']);
 401		}
 402
 403		return $encoder_options;
 404	}
 405
 406
 407	function decodeMPEGaudioHeader($offset, &$info, $recursivesearch=true, $ScanAsCBR=false, $FastMPEGheaderScan=false) {
 408		static $MPEGaudioVersionLookup;
 409		static $MPEGaudioLayerLookup;
 410		static $MPEGaudioBitrateLookup;
 411		static $MPEGaudioFrequencyLookup;
 412		static $MPEGaudioChannelModeLookup;
 413		static $MPEGaudioModeExtensionLookup;
 414		static $MPEGaudioEmphasisLookup;
 415		if (empty($MPEGaudioVersionLookup)) {
 416			$MPEGaudioVersionLookup       = getid3_mp3::MPEGaudioVersionArray();
 417			$MPEGaudioLayerLookup         = getid3_mp3::MPEGaudioLayerArray();
 418			$MPEGaudioBitrateLookup       = getid3_mp3::MPEGaudioBitrateArray();
 419			$MPEGaudioFrequencyLookup     = getid3_mp3::MPEGaudioFrequencyArray();
 420			$MPEGaudioChannelModeLookup   = getid3_mp3::MPEGaudioChannelModeArray();
 421			$MPEGaudioModeExtensionLookup = getid3_mp3::MPEGaudioModeExtensionArray();
 422			$MPEGaudioEmphasisLookup      = getid3_mp3::MPEGaudioEmphasisArray();
 423		}
 424
 425		if (fseek($this->getid3->fp, $offset, SEEK_SET) != 0) {
 426			$info['error'][] = 'decodeMPEGaudioHeader() failed to seek to next offset at '.$offset;
 427			return false;
 428		}
 429		//$headerstring = fread($this->getid3->fp, 1441); // worst-case max length = 32kHz @ 320kbps layer 3 = 1441 bytes/frame
 430		$headerstring = fread($this->getid3->fp, 226); // LAME header at offset 36 + 190 bytes of Xing/LAME data
 431
 432		// MP3 audio frame structure:
 433		// $aa $aa $aa $aa [$bb $bb] $cc...
 434		// where $aa..$aa is the four-byte mpeg-audio header (below)
 435		// $bb $bb is the optional 2-byte CRC
 436		// and $cc... is the audio data
 437
 438		$head4 = substr($headerstring, 0, 4);
 439
 440		static $MPEGaudioHeaderDecodeCache = array();
 441		if (isset($MPEGaudioHeaderDecodeCache[$head4])) {
 442			$MPEGheaderRawArray = $MPEGaudioHeaderDecodeCache[$head4];
 443		} else {
 444			$MPEGheaderRawArray = getid3_mp3::MPEGaudioHeaderDecode($head4);
 445			$MPEGaudioHeaderDecodeCache[$head4] = $MPEGheaderRawArray;
 446		}
 447
 448		static $MPEGaudioHeaderValidCache = array();
 449		if (!isset($MPEGaudioHeaderValidCache[$head4])) { // Not in cache
 450			//$MPEGaudioHeaderValidCache[$head4] = getid3_mp3::MPEGaudioHeaderValid($MPEGheaderRawArray, false, true);  // allow badly-formatted freeformat (from LAME 3.90 - 3.93.1)
 451			$MPEGaudioHeaderValidCache[$head4] = getid3_mp3::MPEGaudioHeaderValid($MPEGheaderRawArray, false, false);
 452		}
 453
 454		// shortcut
 455		if (!isset($info['mpeg']['audio'])) {
 456			$info['mpeg']['audio'] = array();
 457		}
 458		$thisfile_mpeg_audio = &$info['mpeg']['audio'];
 459
 460
 461		if ($MPEGaudioHeaderValidCache[$head4]) {
 462			$thisfile_mpeg_audio['raw'] = $MPEGheaderRawArray;
 463		} else {
 464			$info['error'][] = 'Invalid MPEG audio header ('.getid3_lib::PrintHexBytes($head4).') at offset '.$offset;
 465			return false;
 466		}
 467
 468		if (!$FastMPEGheaderScan) {
 469			$thisfile_mpeg_audio['version']       = $MPEGaudioVersionLookup[$thisfile_mpeg_audio['raw']['version']];
 470			$thisfile_mpeg_audio['layer']         = $MPEGaudioLayerLookup[$thisfile_mpeg_audio['raw']['layer']];
 471
 472			$thisfile_mpeg_audio['channelmode']   = $MPEGaudioChannelModeLookup[$thisfile_mpeg_audio['raw']['channelmode']];
 473			$thisfile_mpeg_audio['channels']      = (($thisfile_mpeg_audio['channelmode'] == 'mono') ? 1 : 2);
 474			$thisfile_mpeg_audio['sample_rate']   = $MPEGaudioFrequencyLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['raw']['sample_rate']];
 475			$thisfile_mpeg_audio['protection']    = !$thisfile_mpeg_audio['raw']['protection'];
 476			$thisfile_mpeg_audio['private']       = (bool) $thisfile_mpeg_audio['raw']['private'];
 477			$thisfile_mpeg_audio['modeextension'] = $MPEGaudioModeExtensionLookup[$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['modeextension']];
 478			$thisfile_mpeg_audio['copyright']     = (bool) $thisfile_mpeg_audio['raw']['copyright'];
 479			$thisfile_mpeg_audio['original']      = (bool) $thisfile_mpeg_audio['raw']['original'];
 480			$thisfile_mpeg_audio['emphasis']      = $MPEGaudioEmphasisLookup[$thisfile_mpeg_audio['raw']['emphasis']];
 481
 482			$info['audio']['channels']    = $thisfile_mpeg_audio['channels'];
 483			$info['audio']['sample_rate'] = $thisfile_mpeg_audio['sample_rate'];
 484
 485			if ($thisfile_mpeg_audio['protection']) {
 486				$thisfile_mpeg_audio['crc'] = getid3_lib::BigEndian2Int(substr($headerstring, 4, 2));
 487			}
 488		}
 489
 490		if ($thisfile_mpeg_audio['raw']['bitrate'] == 15) {
 491			// http://www.hydrogenaudio.org/?act=ST&f=16&t=9682&st=0
 492			$info['warning'][] = 'Invalid bitrate index (15), this is a known bug in free-format MP3s encoded by LAME v3.90 - 3.93.1';
 493			$thisfile_mpeg_audio['raw']['bitrate'] = 0;
 494		}
 495		$thisfile_mpeg_audio['padding'] = (bool) $thisfile_mpeg_audio['raw']['padding'];
 496		$thisfile_mpeg_audio['bitrate'] = $MPEGaudioBitrateLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['bitrate']];
 497
 498		if (($thisfile_mpeg_audio['bitrate'] == 'free') && ($offset == $info['avdataoffset'])) {
 499			// only skip multiple frame check if free-format bitstream found at beginning of file
 500			// otherwise is quite possibly simply corrupted data
 501			$recursivesearch = false;
 502		}
 503
 504		// For Layer 2 there are some combinations of bitrate and mode which are not allowed.
 505		if (!$FastMPEGheaderScan && ($thisfile_mpeg_audio['layer'] == '2')) {
 506
 507			$info['audio']['dataformat'] = 'mp2';
 508			switch ($thisfile_mpeg_audio['channelmode']) {
 509
 510				case 'mono':
 511					if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] <= 192000)) {
 512						// these are ok
 513					} else {
 514						$info['error'][] = $thisfile_mpeg_audio['bitrate'].'kbps not allowed in Layer 2, '.$thisfile_mpeg_audio['channelmode'].'.';
 515						return false;
 516					}
 517					break;
 518
 519				case 'stereo':
 520				case 'joint stereo':
 521				case 'dual channel':
 522					if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] == 64000) || ($thisfile_mpeg_audio['bitrate'] >= 96000)) {
 523						// these are ok
 524					} else {
 525						$info['error'][] = intval(round($thisfile_mpeg_audio['bitrate'] / 1000)).'kbps not allowed in Layer 2, '.$thisfile_mpeg_audio['channelmode'].'.';
 526						return false;
 527					}
 528					break;
 529
 530			}
 531
 532		}
 533
 534
 535		if ($info['audio']['sample_rate'] > 0) {
 536			$thisfile_mpeg_audio['framelength'] = getid3_mp3::MPEGaudioFrameLength($thisfile_mpeg_audio['bitrate'], $thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['layer'], (int) $thisfile_mpeg_audio['padding'], $info['audio']['sample_rate']);
 537		}
 538
 539		$nextframetestoffset = $offset + 1;
 540		if ($thisfile_mpeg_audio['bitrate'] != 'free') {
 541
 542			$info['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];
 543
 544			if (isset($thisfile_mpeg_audio['framelength'])) {
 545				$nextframetestoffset = $offset + $thisfile_mpeg_audio['framelength'];
 546			} else {
 547				$info['error'][] = 'Frame at offset('.$offset.') is has an invalid frame length.';
 548				return false;
 549			}
 550
 551		}
 552
 553		$ExpectedNumberOfAudioBytes = 0;
 554
 555		////////////////////////////////////////////////////////////////////////////////////
 556		// Variable-bitrate headers
 557
 558		if (substr($headerstring, 4 + 32, 4) == 'VBRI') {
 559			// Fraunhofer VBR header is hardcoded 'VBRI' at offset 0x24 (36)
 560			// specs taken from http://minnie.tuhs.org/pipermail/mp3encoder/2001-January/001800.html
 561
 562			$thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
 563			$thisfile_mpeg_audio['VBR_method']   = 'Fraunhofer';
 564			$info['audio']['codec']                = 'Fraunhofer';
 565
 566			$SideInfoData = substr($headerstring, 4 + 2, 32);
 567
 568			$FraunhoferVBROffset = 36;
 569
 570			$thisfile_mpeg_audio['VBR_encoder_version']     = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  4, 2)); // VbriVersion
 571			$thisfile_mpeg_audio['VBR_encoder_delay']       = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  6, 2)); // VbriDelay
 572			$thisfile_mpeg_audio['VBR_quality']             = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  8, 2)); // VbriQuality
 573			$thisfile_mpeg_audio['VBR_bytes']               = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 10, 4)); // VbriStreamBytes
 574			$thisfile_mpeg_audio['VBR_frames']              = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 14, 4)); // VbriStreamFrames
 575			$thisfile_mpeg_audio['VBR_seek_offsets']        = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 18, 2)); // VbriTableSize
 576			$thisfile_mpeg_audio['VBR_seek_scale']          = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 20, 2)); // VbriTableScale
 577			$thisfile_mpeg_audio['VBR_entry_bytes']         = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 22, 2)); // VbriEntryBytes
 578			$thisfile_mpeg_audio['VBR_entry_frames']        = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 24, 2)); // VbriEntryFrames
 579
 580			$ExpectedNumberOfAudioBytes = $thisfile_mpeg_audio['VBR_bytes'];
 581
 582			$previousbyteoffset = $offset;
 583			for ($i = 0; $i < $thisfile_mpeg_audio['VBR_seek_offsets']; $i++) {
 584				$Fraunhofer_OffsetN = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset, $thisfile_mpeg_audio['VBR_entry_bytes']));
 585				$FraunhoferVBROffset += $thisfile_mpeg_audio['VBR_entry_bytes'];
 586				$thisfile_mpeg_audio['VBR_offsets_relative'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']);
 587				$thisfile_mpeg_audio['VBR_offsets_absolute'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']) + $previousbyteoffset;
 588				$previousbyteoffset += $Fraunhofer_OffsetN;
 589			}
 590
 591
 592		} else {
 593
 594			// Xing VBR header is hardcoded 'Xing' at a offset 0x0D (13), 0x15 (21) or 0x24 (36)
 595			// depending on MPEG layer and number of channels
 596
 597			$VBRidOffset = getid3_mp3::XingVBRidOffset($thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['channelmode']);
 598			$SideInfoData = substr($headerstring, 4 + 2, $VBRidOffset - 4);
 599
 600			if ((substr($headerstring, $VBRidOffset, strlen('Xing')) == 'Xing') || (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Info')) {
 601				// 'Xing' is traditional Xing VBR frame
 602				// 'Info' is LAME-encoded CBR (This was done to avoid CBR files to be recognized as traditional Xing VBR files by some decoders.)
 603				// 'Info' *can* legally be used to specify a VBR file as well, however.
 604
 605				// http://www.multiweb.cz/twoinches/MP3inside.htm
 606				//00..03 = "Xing" or "Info"
 607				//04..07 = Flags:
 608				//  0x01  Frames Flag     set if value for number of frames in file is stored
 609				//  0x02  Bytes Flag      set if value for filesize in bytes is stored
 610				//  0x04  TOC Flag        set if values for TOC are stored
 611				//  0x08  VBR Scale Flag  set if values for VBR scale is stored
 612				//08..11  Frames: Number of frames in file (including the first Xing/Info one)
 613				//12..15  Bytes:  File length in Bytes
 614				//16..115  TOC (Table of Contents):
 615				//  Contains of 100 indexes (one Byte length) for easier lookup in file. Approximately solves problem with moving inside file.
 616				//  Each Byte has a value according this formula:
 617				//  (TOC[i] / 256) * fileLenInBytes
 618				//  So if song lasts eg. 240 sec. and you want to jump to 60. sec. (and file is 5 000 000 Bytes length) you can use:
 619				//  TOC[(60/240)*100] = TOC[25]
 620				//  and corresponding Byte in file is then approximately at:
 621				//  (TOC[25]/256) * 5000000
 622				//116..119  VBR Scale
 623
 624
 625				// should be safe to leave this at 'vbr' and let it be overriden to 'cbr' if a CBR preset/mode is used by LAME
 626//				if (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Xing') {
 627					$thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
 628					$thisfile_mpeg_audio['VBR_method']   = 'Xing';
 629//				} else {
 630//					$ScanAsCBR = true;
 631//					$thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
 632//				}
 633
 634				$thisfile_mpeg_audio['xing_flags_raw'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 4, 4));
 635
 636				$thisfile_mpeg_audio['xing_flags']['frames']    = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000001);
 637				$thisfile_mpeg_audio['xing_flags']['bytes']     = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000002);
 638				$thisfile_mpeg_audio['xing_flags']['toc']       = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000004);
 639				$thisfile_mpeg_audio['xing_flags']['vbr_scale'] = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000008);
 640
 641				if ($thisfile_mpeg_audio['xing_flags']['frames']) {
 642					$thisfile_mpeg_audio['VBR_frames'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset +  8, 4));
 643					//$thisfile_mpeg_audio['VBR_frames']--; // don't count header Xing/Info frame
 644				}
 645				if ($thisfile_mpeg_audio['xing_flags']['bytes']) {
 646					$thisfile_mpeg_audio['VBR_bytes']  = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 12, 4));
 647				}
 648
 649				//if (($thisfile_mpeg_audio['bitrate'] == 'free') && !empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {
 650				if (!empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {
 651
 652					$framelengthfloat = $thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames'];
 653
 654					if ($thisfile_mpeg_audio['layer'] == '1') {
 655						// BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
 656						//$info['audio']['bitrate'] = ((($framelengthfloat / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
 657						$info['audio']['bitrate'] = ($framelengthfloat / 4) * $thisfile_mpeg_audio['sample_rate'] * (2 / $info['audio']['channels']) / 12;
 658					} else {
 659						// Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
 660						//$info['audio']['bitrate'] = (($framelengthfloat - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
 661						$info['audio']['bitrate'] = $framelengthfloat * $thisfile_mpeg_audio['sample_rate'] * (2 / $info['audio']['channels']) / 144;
 662					}
 663					$thisfile_mpeg_audio['framelength'] = floor($framelengthfloat);
 664				}
 665
 666				if ($thisfile_mpeg_audio['xing_flags']['toc']) {
 667					$LAMEtocData = substr($headerstring, $VBRidOffset + 16, 100);
 668					for ($i = 0; $i < 100; $i++) {
 669						$thisfile_mpeg_audio['toc'][$i] = ord($LAMEtocData{$i});
 670					}
 671				}
 672				if ($thisfile_mpeg_audio['xing_flags']['vbr_scale']) {
 673					$thisfile_mpeg_audio['VBR_scale'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 116, 4));
 674				}
 675
 676
 677				// http://gabriel.mp3-tech.org/mp3infotag.html
 678				if (substr($headerstring, $VBRidOffset + 120, 4) == 'LAME') {
 679
 680					// shortcut
 681					$thisfile_mpeg_audio['LAME'] = array();
 682					$thisfile_mpeg_audio_lame    = &$thisfile_mpeg_audio['LAME'];
 683
 684
 685					$thisfile_mpeg_audio_lame['long_version']  = substr($headerstring, $VBRidOffset + 120, 20);
 686					$thisfile_mpeg_audio_lame['short_version'] = substr($thisfile_mpeg_audio_lame['long_version'], 0, 9);
 687
 688					if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.90') {
 689
 690						// extra 11 chars are not part of version string when LAMEtag present
 691						unset($thisfile_mpeg_audio_lame['long_version']);
 692
 693						// It the LAME tag was only introduced in LAME v3.90
 694						// http://www.hydrogenaudio.org/?act=ST&f=15&t=9933
 695
 696						// Offsets of various bytes in http://gabriel.mp3-tech.org/mp3infotag.html
 697						// are assuming a 'Xing' identifier offset of 0x24, which is the case for
 698						// MPEG-1 non-mono, but not for other combinations
 699						$LAMEtagOffsetContant = $VBRidOffset - 0x24;
 700
 701						// shortcuts
 702						$thisfile_mpeg_audio_lame['RGAD']    = array('track'=>array(), 'album'=>array());
 703						$thisfile_mpeg_audio_lame_RGAD       = &$thisfile_mpeg_audio_lame['RGAD'];
 704						$thisfile_mpeg_audio_lame_RGAD_track = &$thisfile_mpeg_audio_lame_RGAD['track'];
 705						$thisfile_mpeg_audio_lame_RGAD_album = &$thisfile_mpeg_audio_lame_RGAD['album'];
 706						$thisfile_mpeg_audio_lame['raw'] = array();
 707						$thisfile_mpeg_audio_lame_raw    = &$thisfile_mpeg_audio_lame['raw'];
 708
 709						// byte $9B  VBR Quality
 710						// This field is there to indicate a quality level, although the scale was not precised in the original Xing specifications.
 711						// Actually overwrites original Xing bytes
 712						unset($thisfile_mpeg_audio['VBR_scale']);
 713						$thisfile_mpeg_audio_lame['vbr_quality'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0x9B, 1));
 714
 715						// bytes $9C-$A4  Encoder short VersionString
 716						$thisfile_mpeg_audio_lame['short_version'] = substr($headerstring, $LAMEtagOffsetContant + 0x9C, 9);
 717
 718						// byte $A5  Info Tag revision + VBR method
 719						$LAMEtagRevisionVBRmethod = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA5, 1));
 720
 721						$thisfile_mpeg_audio_lame['tag_revision']   = ($LAMEtagRevisionVBRmethod & 0xF0) >> 4;
 722						$thisfile_mpeg_audio_lame_raw['vbr_method'] =  $LAMEtagRevisionVBRmethod & 0x0F;
 723						$thisfile_mpeg_audio_lame['vbr_method']     = getid3_mp3::LAMEvbrMethodLookup($thisfile_mpeg_audio_lame_raw['vbr_method']);
 724						$thisfile_mpeg_audio['bitrate_mode']        = substr($thisfile_mpeg_audio_lame['vbr_method'], 0, 3); // usually either 'cbr' or 'vbr', but truncates 'vbr-old / vbr-rh' to 'vbr'
 725
 726						// byte $A6  Lowpass filter value
 727						$thisfile_mpeg_audio_lame['lowpass_frequency'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA6, 1)) * 100;
 728
 729						// bytes $A7-$AE  Replay Gain
 730						// http://privatewww.essex.ac.uk/~djmrob/replaygain/rg_data_format.html
 731						// bytes $A7-$AA : 32 bit floating point "Peak signal amplitude"
 732						if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.94b') {
 733							// LAME 3.94a16 and later - 9.23 fixed point
 734							// ie 0x0059E2EE / (2^23) = 5890798 / 8388608 = 0.7022378444671630859375
 735							$thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = (float) ((getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4))) / 8388608);
 736						} else {
 737							// LAME 3.94a15 and earlier - 32-bit floating point
 738							// Actually 3.94a16 will fall in here too and be WRONG, but is hard to detect 3.94a16 vs 3.94a15
 739							$thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = getid3_lib::LittleEndian2Float(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4));
 740						}
 741						if ($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] == 0) {
 742							unset($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);
 743						} else {
 744							$thisfile_mpeg_audio_lame_RGAD['peak_db'] = getid3_lib::RGADamplitude2dB($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);
 745						}
 746
 747						$thisfile_mpeg_audio_lame_raw['RGAD_track']      =   getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAB, 2));
 748						$thisfile_mpeg_audio_lame_raw['RGAD_album']      =   getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAD, 2));
 749
 750
 751						if ($thisfile_mpeg_audio_lame_raw['RGAD_track'] != 0) {
 752
 753							$thisfile_mpeg_audio_lame_RGAD_track['raw']['name']        = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0xE000) >> 13;
 754							$thisfile_mpeg_audio_lame_RGAD_track['raw']['originator']  = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x1C00) >> 10;
 755							$thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit']    = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x0200) >> 9;
 756							$thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'] =  $thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x01FF;
 757							$thisfile_mpeg_audio_lame_RGAD_track['name']       = getid3_lib::RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['name']);
 758							$thisfile_mpeg_audio_lame_RGAD_track['originator'] = getid3_lib::RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['originator']);
 759							$thisfile_mpeg_audio_lame_RGAD_track['gain_db']    = getid3_lib::RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit']);
 760
 761							if (!empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'])) {
 762								$info['replay_gain']['track']['peak']   = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];
 763							}
 764							$info['replay_gain']['track']['originator'] = $thisfile_mpeg_audio_lame_RGAD_track['originator'];
 765							$info['replay_gain']['track']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_track['gain_db'];
 766						} else {
 767							unset($thisfile_mpeg_audio_lame_RGAD['track']);
 768						}
 769						if ($thisfile_mpeg_audio_lame_raw['RGAD_album'] != 0) {
 770
 771							$thisfile_mpeg_audio_lame_RGAD_album['raw']['name']        = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0xE000) >> 13;
 772							$thisfile_mpeg_audio_lame_RGAD_album['raw']['originator']  = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x1C00) >> 10;
 773							$thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit']    = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x0200) >> 9;
 774							$thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'] = $thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x01FF;
 775							$thisfile_mpeg_audio_lame_RGAD_album['name']       = getid3_lib::RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['name']);
 776							$thisfile_mpeg_audio_lame_RGAD_album['originator'] = getid3_lib::RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['originator']);
 777							$thisfile_mpeg_audio_lame_RGAD_album['gain_db']    = getid3_lib::RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit']);
 778
 779							if (!empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'])) {
 780								$info['replay_gain']['album']['peak']   = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];
 781							}
 782							$info['replay_gain']['album']['originator'] = $thisfile_mpeg_audio_lame_RGAD_album['originator'];
 783							$info['replay_gain']['album']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_album['gain_db'];
 784						} else {
 785							unset($thisfile_mpeg_audio_lame_RGAD['album']);
 786						}
 787						if (empty($thisfile_mpeg_audio_lame_RGAD)) {
 788							unset($thisfile_mpeg_audio_lame['RGAD']);
 789						}
 790
 791
 792						// byte $AF  Encoding flags + ATH Type
 793						$EncodingFlagsATHtype = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAF, 1));
 794						$thisfile_mpeg_audio_lame['encoding_flags']['nspsytune']   = (bool) ($EncodingFlagsATHtype & 0x10);
 795						$thisfile_mpeg_audio_lame['encoding_flags']['nssafejoint'] = (bool) ($EncodingFlagsATHtype & 0x20);
 796						$thisfile_mpeg_audio_lame['encoding_flags']['nogap_next']  = (bool) ($EncodingFlagsATHtype & 0x40);
 797						$thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev']  = (bool) ($EncodingFlagsATHtype & 0x80);
 798						$thisfile_mpeg_audio_lame['ath_type']                      =         $EncodingFlagsATHtype & 0x0F;
 799
 800						// byte $B0  if ABR {specified bitrate} else {minimal bitrate}
 801						$thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB0, 1));
 802						if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 2) { // Average BitRate (ABR)
 803							$thisfile_mpeg_audio_lame['bitrate_abr'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];
 804						} elseif ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1) { // Constant BitRate (CBR)
 805							// ignore
 806						} elseif ($thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] > 0) { // Variable BitRate (VBR) - minimum bitrate
 807							$thisfile_mpeg_audio_lame['bitrate_min'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];
 808						}
 809
 810						// bytes $B1-$B3  Encoder delays
 811						$EncoderDelays = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB1, 3));
 812						$thisfile_mpeg_audio_lame['encoder_delay'] = ($EncoderDelays & 0xFFF000) >> 12;
 813						$thisfile_mpeg_audio_lame['end_padding']   =  $EncoderDelays & 0x000FFF;
 814
 815						// byte $B4  Misc
 816						$MiscByte = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB4, 1));
 817						$thisfile_mpeg_audio_lame_raw['noise_shaping']       = ($MiscByte & 0x03);
 818						$thisfile_mpeg_audio_lame_raw['stereo_mode']         = ($MiscByte & 0x1C) >> 2;
 819						$thisfile_mpeg_audio_lame_raw['not_optimal_quality'] = ($MiscByte & 0x20) >> 5;
 820						$thisfile_mpeg_audio_lame_raw['source_sample_freq']  = ($MiscByte & 0xC0) >> 6;
 821						$thisfile_mpeg_audio_lame['noise_shaping']       = $thisfile_mpeg_audio_lame_raw['noise_shaping'];
 822						$thisfile_mpeg_audio_lame['stereo_mode']         = getid3_mp3::LAMEmiscStereoModeLookup($thisfile_mpeg_audio_lame_raw['stereo_mode']);
 823						$thisfile_mpeg_audio_lame['not_optimal_quality'] = (bool) $thisfile_mpeg_audio_lame_raw['not_optimal_quality'];
 824						$thisfile_mpeg_audio_lame['source_sample_freq']  = getid3_mp3::LAMEmiscSourceSampleFrequencyLookup($thisfile_mpeg_audio_lame_raw['source_sample_freq']);
 825
 826						// byte $B5  MP3 Gain
 827						$thisfile_mpeg_audio_lame_raw['mp3_gain'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB5, 1), false, true);
 828						$thisfile_mpeg_audio_lame['mp3_gain_db']     = (getid3_lib::RGADamplitude2dB(2) / 4) * $thisfile_mpeg_audio_lame_raw['mp3_gain'];
 829						$thisfile_mpeg_audio_lame['mp3_gain_factor'] = pow(2, ($thisfile_mpeg_audio_lame['mp3_gain_db'] / 6));
 830
 831						// bytes $B6-$B7  Preset and surround info
 832						$PresetSurroundBytes = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB6, 2));
 833						// Reserved                                                    = ($PresetSurroundBytes & 0xC000);
 834						$thisfile_mpeg_audio_lame_raw['surround_info'] = ($PresetSurroundBytes & 0x3800);
 835						$thisfile_mpeg_audio_lame['surround_info']     = getid3_mp3::LAMEsurroundInfoLookup($thisfile_mpeg_audio_lame_raw['surround_info']);
 836						$thisfile_mpeg_audio_lame['preset_used_id']    = ($PresetSurroundBytes & 0x07FF);
 837						$thisfile_mpeg_audio_lame['preset_used']       = getid3_mp3::LAMEpresetUsedLookup($thisfile_mpeg_audio_lame);
 838						if (!empty($thisfile_mpeg_audio_lame['preset_used_id']) && empty($thisfile_mpeg_audio_lame['preset_used'])) {
 839							$info['warning'][] = 'Unknown LAME preset used ('.$thisfile_mpeg_audio_lame['preset_used_id'].') - please report to info@getid3.org';
 840						}
 841						if (($thisfile_mpeg_audio_lame['short_version'] == 'LAME3.90.') && !empty($thisfile_mpeg_audio_lame['preset_used_id'])) {
 842							// this may change if 3.90.4 ever comes out
 843							$thisfile_mpeg_audio_lame['short_version'] = 'LAME3.90.3';
 844						}
 845
 846						// bytes $B8-$BB  MusicLength
 847						$thisfile_mpeg_audio_lame['audio_bytes'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB8, 4));
 848						$ExpectedNumberOfAudioBytes = (($thisfile_mpeg_audio_lame['audio_bytes'] > 0) ? $thisfile_mpeg_audio_lame['audio_bytes'] : $thisfile_mpeg_audio['VBR_bytes']);
 849
 850						// bytes $BC-$BD  MusicCRC
 851						$thisfile_mpeg_audio_lame['music_crc']    = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBC, 2));
 852
 853						// bytes $BE-$BF  CRC-16 of Info Tag
 854						$thisfile_mpeg_audio_lame['lame_tag_crc'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBE, 2));
 855
 856
 857						// LAME CBR
 858						if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1) {
 859
 860							$thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
 861							$thisfile_mpeg_audio['bitrate'] = getid3_mp3::ClosestStandardMP3Bitrate($thisfile_mpeg_audio['bitrate']);
 862							$info['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];
 863							//if (empty($thisfile_mpeg_audio['bitrate']) || (!empty($thisfile_mpeg_audio_lame['bitrate_min']) && ($thisfile_mpeg_audio_lame['bitrate_min'] != 255))) {
 864							//	$thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio_lame['bitrate_min'];
 865							//}
 866
 867						}
 868
 869					}
 870				}
 871
 872			} else {
 873
 874				// not Fraunhofer or Xing VBR methods, most likely CBR (but could be VBR with no header)
 875				$thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
 876				if ($recursivesearch) {
 877					$thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
 878					if ($this->RecursiveFrameScanning($offset, $nextframetestoffset, true)) {
 879						$recursivesearch = false;
 880						$thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
 881					}
 882					if ($thisfile_mpeg_audio['bitrate_mode'] == 'vbr') {
 883						$info['warning'][] = 'VBR file with no VBR header. Bitrate values calculated from actual frame bitrates.';
 884					}
 885				}
 886
 887			}
 888
 889		}
 890
 891		if (($ExpectedNumberOfAudioBytes > 0) && ($ExpectedNumberOfAudioBytes != ($info['avdataend'] - $info['avdataoffset']))) {
 892			if ($ExpectedNumberOfAudioBytes > ($info['avdataend'] - $info['avdataoffset'])) {
 893				if (isset($info['fileformat']) && ($info['fileformat'] == 'riff')) {
 894					// ignore, audio data is broken into chunks so will always be data "missing"
 895				} elseif (($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])) == 1) {
 896					$info['warning'][] = 'Last byte of data truncated (this is a known bug in Meracl ID3 Tag Writer before v1.3.5)';
 897				} else {
 898					$info['warning'][] = 'Probable truncated file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, only found '.($info['avdataend'] - $info['avdataoffset']).' (short by '.($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])).' bytes)';
 899				}
 900			} else {
 901				if ((($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes) == 1) {
 902				//	$prenullbytefileoffset = ftell($this->getid3->fp);
 903				//	fseek($this->getid3->fp, $info['avdataend'], SEEK_SET);
 904				//	$PossibleNullByte = fread($this->getid3->fp, 1);
 905				//	fseek($this->getid3->fp, $prenullbytefileoffset, SEEK_SET);
 906				//	if ($PossibleNullByte === "\x00") {
 907						$info['avdataend']--;
 908				//		$info['warning'][] = 'Extra null byte at end of MP3 data assumed to be RIFF padding and therefore ignored';
 909				//	} else {
 910				//		$info['warning'][] = 'Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']).' ('.(($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)';
 911				//	}
 912				} else {
 913					$info['warning'][] = 'Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']).' ('.(($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)';
 914				}
 915			}
 916		}
 917
 918		if (($thisfile_mpeg_audio['bitrate'] == 'free') && empty($info['audio']['bitrate'])) {
 919			if (($offset == $info['avdataoffset']) && empty($thisfile_mpeg_audio['VBR_frames'])) {
 920				$framebytelength = $this->FreeFormatFrameLength($offset, true);
 921				if ($framebytelength > 0) {
 922					$thisfile_mpeg_audio['framelength'] = $framebytelength;
 923					if ($thisfile_mpeg_audio['layer'] == '1') {
 924						// BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
 925						$info['audio']['bitrate'] = ((($framebytelength / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
 926					} else {
 927						// Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
 928						$info['audio']['bitrate'] = (($framebytelength - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
 929					}
 930				} else {
 931					$info['error'][] = 'Error calculating frame length of free-format MP3 without Xing/LAME header';
 932				}
 933			}
 934		}
 935
 936		if (isset($thisfile_mpeg_audio['VBR_frames']) ? $thisfile_mpeg_audio['VBR_frames'] : '') {
 937			switch ($thisfile_mpeg_audio['bitrate_mode']) {
 938				case 'vbr':
 939				case 'abr':
 940					$bytes_per_frame = 1152;
 941					if (($thisfile_mpeg_audio['version'] == '1') && ($thisfile_mpeg_audio['layer'] == 1)) {
 942						$bytes_per_frame = 384;
 943					} elseif ((($thisfile_mpeg_audio['version'] == '2') || ($thisfile_mpeg_audio['version'] == '2.5')) && ($thisfile_mpeg_audio['layer'] == 3)) {
 944						$bytes_per_frame = 576;
 945					}
 946					$thisfile_mpeg_audio['VBR_bitrate'] = (isset($thisfile_mpeg_audio['VBR_bytes']) ? (($thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames']) * 8) * ($info['audio']['sample_rate'] / $bytes_per_frame) : 0);
 947					if ($thisfile_mpeg_audio['VBR_bitrate'] > 0) {
 948						$info['audio']['bitrate']         = $thisfile_mpeg_audio['VBR_bitrate'];
 949						$thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio['VBR_bitrate']; // to avoid confusion
 950					}
 951					break;
 952			}
 953		}
 954
 955		// End variable-bitrate headers
 956		////////////////////////////////////////////////////////////////////////////////////
 957
 958		if ($recursivesearch) {
 959
 960			if (!$this->RecursiveFrameScanning($offset, $nextframetestoffset, $ScanAsCBR)) {
 961				return false;
 962			}
 963
 964		}
 965
 966
 967		//if (false) {
 968		//    // experimental side info parsing section - not returning anything useful yet
 969		//
 970		//    $SideInfoBitstream = getid3_lib::BigEndian2Bin($SideInfoData);
 971		//    $SideInfoOffset = 0;
 972		//
 973		//    if ($thisfile_mpeg_audio['version'] == '1') {
 974		//        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
 975		//            // MPEG-1 (mono)
 976		//            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
 977		//            $SideInfoOffset += 9;
 978		//            $SideInfoOffset += 5;
 979		//        } else {
 980		//            // MPEG-1 (stereo, joint-stereo, dual-channel)
 981		//            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
 982		//            $SideInfoOffset += 9;
 983		//            $SideInfoOffset += 3;
 984		//        }
 985		//    } else { // 2 or 2.5
 986		//        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
 987		//            // MPEG-2, MPEG-2.5 (mono)
 988		//            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
 989		//            $SideInfoOffset += 8;
 990		//            $SideInfoOffset += 1;
 991		//        } else {
 992		//            // MPEG-2, MPEG-2.5 (stereo, joint-stereo, dual-channel)
 993		//            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
 994		//            $SideInfoOffset += 8;
 995		//            $SideInfoOffset += 2;
 996		//        }
 997		//    }
 998		//
 999		//    if ($thisfile_mpeg_audio['version'] == '1') {
1000		//        for ($channel = 0; $channel < $info['audio']['channels']; $channel++) {
1001		//            for ($scfsi_band = 0; $scfsi_band < 4; $scfsi_band++) {
1002		//                $thisfile_mpeg_audio['scfsi'][$channel][$scfsi_band] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1003		//                $SideInfoOffset += 2;
1004		//            }
1005		//        }
1006		//    }
1007		//    for ($granule = 0; $granule < (($thisfile_mpeg_audio['version'] == '1') ? 2 : 1); $granule++) {
1008		//        for ($channel = 0; $channel < $info['audio']['channels']; $channel++) {
1009		//            $thisfile_mpeg_audio['part2_3_length'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 12);
1010		//            $SideInfoOffset += 12;
1011		//            $thisfile_mpeg_audio['big_values'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1012		//            $SideInfoOffset += 9;
1013		//            $thisfile_mpeg_audio['global_gain'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 8);
1014		//            $SideInfoOffset += 8;
1015		//            if ($thisfile_mpeg_audio['version'] == '1') {
1016		//                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
1017		//                $SideInfoOffset += 4;
1018		//            } else {
1019		//                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1020		//                $SideInfoOffset += 9;
1021		//            }
1022		//            $thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1023		//            $SideInfoOffset += 1;
1024		//
1025		//            if ($thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] == '1') {
1026		//
1027		//                $thisfile_mpeg_audio['block_type'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 2);
1028		//                $SideInfoOffset += 2;
1029		//                $thisfile_mpeg_audio['mixed_block_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1030		//                $SideInfoOffset += 1;
1031		//
1032		//                for ($region = 0; $region < 2; $region++) {
1033		//                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
1034		//                    $SideInfoOffset += 5;
1035		//                }
1036		//                $thisfile_mpeg_audio['table_select'][$granule][$channel][2] = 0;
1037		//
1038		//                for ($window = 0; $window < 3; $window++) {
1039		//                    $thisfile_mpeg_audio['subblock_gain'][$granule][$channel][$window] = substr($SideInfoBitstream, $SideInfoOffset, 3);
1040		//                    $SideInfoOffset += 3;
1041		//                }
1042		//
1043		//            } else {
1044		//
1045		//                for ($region = 0; $region < 3; $region++) {
1046		//                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
1047		//                    $SideInfoOffset += 5;
1048		//                }
1049		//
1050		//                $thisfile_mpeg_audio['region0_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
1051		//                $SideInfoOffset += 4;
1052		//                $thisfile_mpeg_audio['region1_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 3);
1053		//                $SideInfoOffset += 3;
1054		//                $thisfile_mpeg_audio['block_type'][$granule][$channel] = 0;
1055		//            }
1056		//
1057		//            if ($thisfile_mpeg_audio['version'] == '1') {
1058		//                $thisfile_mpeg_audio['preflag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1059		//                $SideInfoOffset += 1;
1060		//            }
1061		//            $thisfile_mpeg_audio['scalefac_scale'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1062		//            $SideInfoOffset += 1;
1063		//            $thisfile_mpeg_audio['count1table_select'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1064		//            $SideInfoOffset += 1;
1065		//        }
1066		//    }
1067		//}
1068
1069		return true;
1070	}
1071
1072	function RecursiveFrameScanning(&$offset, &$nextframetestoffset, $ScanAsCBR) {
1073		$info = &$this->getid3->info;
1074		$firstframetestarray = array('error'=>'', 'warning'=>'', 'avdataend'=>$info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1075		$this->decodeMPEGaudioHeader($offset, $firstframetestarray, false);
1076
1077		for ($i = 0; $i < GETID3_MP3_VALID_CHECK_FRAMES; $i++) {
1078			// check next GETID3_MP3_VALID_CHECK_FRAMES frames for validity, to make sure we haven't run across a false synch
1079			if (($nextframetestoffset + 4) >= $info['avdataend']) {
1080				// end of file
1081				return true;
1082			}
1083
1084			$nextframetestarray = array('error'=>'', 'warning'=>'', 'avdataend'=>$info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1085			if ($this->decodeMPEGaudioHeader($nextframetestoffset, $nextframetestarray, false)) {
1086				if ($ScanAsCBR) {
1087					// force CBR mode, used for trying to pick out invalid audio streams with valid(?) VBR headers, or VBR streams with no VBR header
1088					if (!isset($nextframetestarray['mpeg']['audio']['bitrate']) || !isset($firstframetestarray['mpeg']['audio']['bitrate']) || ($nextframetestarray['mpeg']['audio']['bitrate'] != $firstframetestarray['mpeg']['audio']['bitrate'])) {
1089						return false;
1090					}
1091				}
1092
1093
1094				// next frame is OK, get ready to check the one after that
1095				if (isset($nextframetestarray['mpeg']['audio']['framelength']) && ($nextframetestarray['mpeg']['audio']['framelength'] > 0)) {
1096					$nextframetestoffset += $nextframetestarray['mpeg']['audio']['framelength'];
1097				} else {
1098					$info['error'][] = 'Frame at offset ('.$offset.') is has an invalid frame length.';
1099					return false;
1100				}
1101
1102			} elseif (!empty($firstframetestarray['mpeg']['audio']['framelength']) && (($nextframetestoffset + $firstframetestarray['mpeg']['audio']['framelength']) > $info['avdataend'])) {
1103
1104				// it's not the end of the file, but there's not enough data left for another frame, so assume it's garbage/padding and return OK
1105				return true;
1106
1107			} else {
1108
1109				// next frame is not valid, note the error and fail, so scanning can contiue for a valid frame sequence
1110				$info['warning'][] = 'Frame at offset ('.$offset.') is valid, but the next one at ('.$nextframetestoffset.') is not.';
1111
1112				return false;
1113			}
1114		}
1115		return true;
1116	}
1117
1118	function FreeFormatFrameLength($offset, $deepscan=false) {
1119		$info = &$this->getid3->info;
1120
1121		fseek($this->getid3->fp, $offset, SEEK_SET);
1122		$MPEGaudioData = fread($this->getid3->fp, 32768);
1123
1124		$SyncPattern1 = substr($MPEGaudioData, 0, 4);
1125		// may be different pattern due to padding
1126		$SyncPattern2 = $SyncPattern1{0}.$SyncPattern1{1}.chr(ord($SyncPattern1{2}) | 0x02).$SyncPattern1{3};
1127		if ($SyncPattern2 === $SyncPattern1) {
1128			$SyncPattern2 = $SyncPattern1{0}.$SyncPattern1{1}.chr(ord($SyncPattern1{2}) & 0xFD).$SyncPattern1{3};
1129		}
1130
1131		$framelength = false;
1132		$framelength1 = strpos($MPEGaudioData, $SyncPattern1, 4);
1133		$framelength2 = strpos($MPEGaudioData, $SyncPattern2, 4);
1134		if ($framelength1 > 4) {
1135			$framelength = $framelength1;
1136		}
1137		if (($framelength2 > 4) && ($framelength2 < $framelength1)) {
1138			$framelength = $framelength2;
1139		}
1140		if (!$framelength) {
1141
1142			// LAME 3.88 has a different value for modeextension on the first frame vs the rest
1143			$framelength1 = strpos($MPEGaudioData, substr($SyncPattern1, 0, 3), 4);
1144			$framelength2 = strpos($MPEGaudioData, substr($SyncPattern2, 0, 3), 4);
1145
1146			if ($framelength1 > 4) {
1147				$framelength = $framelength1;
1148			}
1149			if (($framelength2 > 4) && ($framelength2 < $framelength1)) {
1150				$framelength = $framelength2;
1151			}
1152			if (!$framelength) {
1153				$info['error'][] = 'Cannot find next free-format synch pattern ('.getid3_lib::PrintHexBytes($SyncPattern1).' or '.getid3_lib::PrintHexBytes($SyncPattern2).') after offset '.$offset;
1154				return false;
1155			} else {
1156				$info['warning'][] = 'ModeExtension varies between first frame and other frames (known free-format issue in LAME 3.88)';
1157				$info['audio']['codec']   = 'LAME';
1158				$info['audio']['encoder'] = 'LAME3.88';
1159				$SyncPattern1 = substr($SyncPattern1, 0, 3);
1160				$SyncPattern2 = substr($SyncPattern2, 0, 3);
1161			}
1162		}
1163
1164		if ($deepscan) {
1165
1166			$ActualFrameLengthValues = array();
1167			$nextoffset = $offset + $framelength;
1168			while ($nextoffset < ($info['avdataend'] - 6)) {
1169				fseek($this->getid3->fp, $nextoffset - 1, SEEK_SET);
1170				$NextSyncPattern = fread($this->getid3->fp, 6);
1171				if ((substr($NextSyncPattern, 1, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 1, strlen($SyncPattern2)) == $SyncPattern2)) {
1172					// good - found where expected
1173					$ActualFrameLengthValues[] = $framelength;
1174				} elseif ((substr($NextSyncPattern, 0, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 0, strlen($SyncPattern2)) == $SyncPattern2)) {
1175					// ok - found one byte earlier than expected (last frame wasn't padded, first frame was)
1176					$ActualFrameLengthValues[] = ($framelength - 1);
1177					$nextoffset--;
1178				} elseif ((substr($NextSyncPattern, 2, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 2, strlen($SyncPattern2)) == $SyncPattern2)) {
1179					// ok - found one byte later than expected (last frame was padded, first frame wasn't)
1180					$ActualFrameLengthValues[] = ($framelength + 1);
1181					$nextoffset++;
1182				} else {
1183					$info['error'][] = 'Did not find expected free-format sync pattern at offset '.$nextoffset;
1184					return false;
1185				}
1186				$nextoffset += $framelength;
1187			}
1188			if (count($ActualFrameLengthValues) > 0) {
1189				$framelength = intval(round(array_sum($ActualFrameLengthValues) / count($ActualFrameLengthValues)));
1190			}
1191		}
1192		return $framelength;
1193	}
1194
1195	function getOnlyMPEGaudioInfoBruteForce() {
1196		$MPEGaudioHeaderDecodeCache   = array();
1197		$MPEGaudioHeaderValidCache    = array();
1198		$MPEGaudioHeaderLengthCache   = array();
1199		$MPEGaudioVersionLookup       = getid3_mp3::MPEGaudioVersionArray();
1200		$MPEGaudioLayerLookup         = getid3_mp3::MPEGaudioLayerArray();
1201		$MPEGaudioBitrateLookup       = getid3_mp3::MPEGaudioBitrateArray();
1202		$MPEGaudioFrequencyLookup     = getid3_mp3::MPEGaudioFrequencyArray();
1203		$MPEGaudioChannelModeLookup   = getid3_mp3::MPEGaudioChannelModeArray();
1204		$MPEGaudioModeExtensionLookup = getid3_mp3::MPEGaudioModeExtensionArray();
1205		$MPEGaudioEmphasisLookup      = getid3_mp3::MPEGaudioEmphasisArray();
1206		$LongMPEGversionLookup        = array();
1207		$LongMPEGlayerLookup          = array();
1208		$LongMPEGbitrateLookup        = array();
1209		$LongMPEGpaddingLookup        = array();
1210		$LongMPEGfrequencyLookup      = array();
1211		$Distribution['bitrate']      = array();
1212		$Distribution['frequency']    = array();
1213		$Distribution['layer']        = array();
1214		$Distribution['version']      = array();
1215		$Distribution['padding']      = array();
1216
1217		$info = &$this->getid3->info;
1218		fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
1219
1220		$max_frames_scan = 5000;
1221		$frames_scanned  = 0;
1222
1223		$previousvalidframe = $info['avdataoffset'];
1224		while (ftell($this->getid3->fp) < $info['avdataend']) {
1225			set_time_limit(30);
1226			$head4 = fread($this->getid3->fp, 4);
1227			if (strlen($head4) < 4) {
1228				break;
1229			}
1230			if ($head4{0} != "\xFF") {
1231				for ($i = 1; $i < 4; $i++) {
1232					if ($head4{$i} == "\xFF") {
1233						fseek($this->getid3->fp, $i - 4, SEEK_CUR);
1234						continue 2;
1235					}
1236				}
1237				continue;
1238			}
1239			if (!isset($MPEGaudioHeaderDecodeCache[$head4])) {
1240				$MPEGaudioHeaderDecodeCache[$head4] = getid3_mp3::MPEGaudioHeaderDecode($head4);
1241			}
1242			if (!isset($MPEGaudioHeaderValidCache[$head4])) {
1243				$MPEGaudioHeaderValidCache[$head4] = getid3_mp3::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$head4], false, false);
1244			}
1245			if ($MPEGaudioHeaderValidCache[$head4]) {
1246
1247				if (!isset($MPEGaudioHeaderLengthCache[$head4])) {
1248					$LongMPEGversionLookup[$head4]   = $MPEGaudioVersionLookup[$MPEGaudioHeaderDecodeCache[$head4]['version']];
1249					$LongMPEGlayerLookup[$head4]     = $MPEGaudioLayerLookup[$MPEGaudioHeaderDecodeCache[$head4]['layer']];
1250					$LongMPEGbitrateLookup[$head4]   = $MPEGaudioBitrateLookup[$LongMPEGversionLookup[$head4]][$LongMPEGlayerLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['bitrate']];
1251					$LongMPEGpaddingLookup[$head4]   = (bool) $MPEGaudioHeaderDecodeCache[$head4]['padding'];
1252					$LongMPEGfrequencyLookup[$head4] = $MPEGaudioFrequencyLookup[$LongMPEGversionLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['sample_rate']];
1253					$MPEGaudioHeaderLengthCache[$head4] = getid3_mp3::MPEGaudioFrameLength(
1254						$LongMPEGbitrateLookup[$head4],
1255						$LongMPEGversionLookup[$head4],
1256						$LongMPEGlayerLookup[$head4],
1257						$LongMPEGpaddingLookup[$head4],
1258						$LongMPEGfrequencyLookup[$head4]);
1259				}
1260				if ($MPEGaudioHeaderLengthCache[$head4] > 4) {
1261					$WhereWeWere = ftell($this->getid3->fp);
1262					fseek($this->getid3->fp, $MPEGaudioHeaderLengthCache[$head4] - 4, SEEK_CUR);
1263					$next4 = fread($this->getid3->fp, 4);
1264					if ($next4{0} == "\xFF") {
1265						if (!isset($MPEGaudioHeaderDecodeCache[$next4])) {
1266							$MPEGaudioHeaderDecodeCache[$next4] = getid3_mp3::MPEGaudioHeaderDecode($next4);
1267						}
1268						if (!isset($MPEGaudioHeaderValidCache[$next4])) {
1269							$MPEGaudioHeaderValidCache[$next4] = getid3_mp3::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$next4], false, false);
1270						}
1271						if ($MPEGaudioHeaderValidCache[$next4]) {
1272							fseek($this->getid3->fp, -4, SEEK_CUR);
1273
1274							getid3_lib::safe_inc($Distribution['bitrate'][$LongMPEGbitrateLookup[$head4]]);
1275							getid3_lib::safe_inc($Distribution['layer'][$LongMPEGlayerLookup[$head4]]);
1276							getid3_lib::safe_inc($Distribution['version'][$LongMPEGversionLookup[$head4]]);
1277							getid3_lib::safe_inc($Distribution['padding'][intval($LongMPEGpaddingLookup[$head4])]);
1278							getid3_lib::safe_inc($Distribution['frequency'][$LongMPEGfrequencyLookup[$head4]]);
1279							if ($max_frames_scan && (++$frames_scanned >= $max_frames_scan)) {
1280								$pct_data_scanned = (ftell($this->getid3->fp) - $info['avdataoffset']) / ($info['avdataend'] - $info['avdataoffset']);
1281								$info['warning'][] = 'too many MPEG audio frames to scan, only scanned first '.$max_frames_scan.' frames ('.number_format($pct_data_scanned * 100, 1).'% of file) and extrapolated distribution, playtime and bitrate may be incorrect.';
1282								foreach ($Distribution as $key1 => $value1) {
1283									foreach ($value1 as $key2 => $value2) {
1284										$Distribution[$key1][$key2] = round($value2 / $pct_data_scanned);
1285									}
1286								}
1287								break;
1288							}
1289							continue;
1290						}
1291					}
1292					unset($next4);
1293					fseek($this->getid3->fp, $WhereWeWere - 3, SEEK_SET);
1294				}
1295
1296			}
1297		}
1298		foreach ($Distribution as $key => $value) {
1299			ksort($Distribution[$key], SORT_NUMERIC);
1300		}
1301		ksort($Distribution['version'], SORT_STRING);
1302		$info['mpeg']['audio']['bitrate_distribution']   = $Distribution['bitrate'];
1303		$info['mpeg']['audio']['frequency_distribution'] = $Distribution['frequency'];
1304		$info['mpeg']['audio']['layer_distribution']     = $Distribution['layer'];
1305		$info['mpeg']['audio']['version_distribution']   = $Distribution['version'];
1306		$info['mpeg']['audio']['padding_distribution']   = $Distribution['padding'];
1307		if (count($Distribution['version']) > 1) {
1308			$info['error'][] = 'Corrupt file - more than one MPEG version detected';
1309		}
1310		if (count($Distribution['layer']) > 1) {
1311			$info['error'][] = 'Corrupt file - more than one MPEG layer detected';
1312		}
1313		if (count($Distribution['frequency']) > 1) {
1314			$info['error'][] = 'Corrupt file - more than one MPEG sample rate detected';
1315		}
1316
1317
1318		$bittotal = 0;
1319		foreach ($Distribution['bitrate'] as $bitratevalue => $bitratecount) {
1320			if ($bitratevalue != 'free') {
1321				$bittotal += ($bitratevalue * $bitratecount);
1322			}
1323		}
1324		$info['mpeg']['audio']['frame_count']  = array_sum($Distribution['bitrate']);
1325		if ($info['mpeg']['audio']['frame_count'] == 0) {
1326			$info['error'][] = 'no MPEG audio frames found';
1327			return false;
1328		}
1329		$info['mpeg']['audio']['bitrate']      = ($bittotal / $info['mpeg']['audio']['frame_count']);
1330		$info['mpeg']['audio']['bitrate_mode'] = ((count($Distribution['bitrate']) > 0) ? 'vbr' : 'cbr');
1331		$info['mpeg']['audio']['sample_rate']  = getid3_lib::array_max($Distribution['frequency'], true);
1332
1333		$info['audio']['bitrate']      = $info['mpeg']['audio']['bitrate'];
1334		$info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
1335		$info['audio']['sample_rate']  = $info['mpeg']['audio']['sample_rate'];
1336		$info['audio']['dataformat']   = 'mp'.getid3_lib::array_max($Distribution['layer'], true);
1337		$info['fileformat']            = $info['audio']['dataformat'];
1338
1339		return true;
1340	}
1341
1342
1343	function getOnlyMPEGaudioInfo($avdataoffset, $BitrateHistogram=false) {
1344		// looks for synch, decodes MPEG audio header
1345
1346		$info = &$this->getid3->info;
1347
1348		static $MPEGaudioVersionLookup;
1349		static $MPEGaudioLayerLookup;
1350		static $MPEGaudioBitrateLookup;
1351		if (empty($MPEGaudioVersionLookup)) {
1352		   $MPEGaudioVersionLookup = getid3_mp3::MPEGaudioVersionArray();
1353		   $MPEGaudioLayerLookup   = getid3_mp3::MPEGaudioLayerArray();
1354		   $MPEGaudioBitrateLookup = getid3_mp3::MPEGaudioBitrateArray();
1355
1356		}
1357
1358		fseek($this->getid3->fp, $avdataoffset, SEEK_SET);
1359		$sync_seek_buffer_size = min(128 * 1024, $info['avdataend'] - $avdataoffset);
1360		if ($sync_seek_buffer_size <= 0) {
1361			$info['error'][] = 'Invalid $sync_seek_buffer_size at offset '.$avdataoffset;
1362			return false;
1363		}
1364		$header = fread($this->getid3->fp, $sync_seek_buffer_size);
1365		$sync_seek_buffer_size = strlen($header);
1366		$SynchSeekOffset = 0;
1367		while ($SynchSeekOffset < $sync_seek_buffer_size) {
1368			if ((($avdataoffset + $SynchSeekOffset)  < $info['avdataend']) && !feof($this->getid3->fp)) {
1369
1370				if ($SynchSeekOffset > $sync_seek_buffer_size) {
1371					// if a synch's not found within the first 128k bytes, then give up
1372					$info['error'][] = 'Could not find valid MPEG audio synch within the first '.round($sync_seek_buffer_size / 1024).'kB';
1373					if (isset($info['audio']['bitrate'])) {
1374						unset($info['audio']['bitrate']);
1375					}
1376					if (isset($info['mpeg']['audio'])) {
1377						unset($info['mpeg']['audio']);
1378					}
1379					if (empty($info['mpeg'])) {
1380						unset($info['mpeg']);
1381					}
1382					return false;
1383
1384				} elseif (feof($this->getid3->fp)) {
1385
1386					$info['error'][] = 'Could not find valid MPEG audio synch before end of file';
1387					if (isset($info['audio']['bitrate'])) {
1388						unset($info['audio']['bitrate']);
1389					}
1390					if (isset($info['mpeg']['audio'])) {
1391						unset($info['mpeg']['audio']);
1392					}
1393					if (isset($info['mpeg']) && (!is_array($info['mpeg']) || (count($info['mpeg']) == 0))) {
1394						unset($info['mpeg']);
1395					}
1396					return false;
1397				}
1398			}
1399
1400			if (($SynchSeekOffset + 1) >= strlen($header)) {
1401				$info['error'][] = 'Could not find valid MPEG synch before end of file';
1402				return false;
1403			}
1404
1405			if (($header{$SynchSeekOffset} == "\xFF") && ($header{($SynchSeekOffset + 1)} > "\xE0")) { // synch detected
1406				if (!isset($FirstFrameThisfileInfo) && !isset($info['mpeg']['audio'])) {
1407					$FirstFrameThisfileInfo = $info;
1408					$FirstFrameAVDataOffset = $avdataoffset + $SynchSeekOffset;
1409					if (!$this->decodeMPEGaudioHeader($FirstFrameAVDataOffset, $FirstFrameThisfileInfo, false)) {
1410						// if this is the first valid MPEG-audio frame, save it in case it's a VBR header frame and there's
1411						// garbage between this frame and a valid sequence of MPEG-audio frames, to be restored below
1412						unset($FirstFrameThisfileInfo);
1413					}
1414				}
1415
1416				$dummy = $info; // only overwrite real data if valid header found
1417				if ($this->decodeMPEGaudioHeader($avdataoffset + $SynchSeekOffset, $dummy, true)) {
1418					$info = $dummy;
1419					$info['avdataoffset'] = $avdataoffset + $SynchSeekOffset;
1420					switch (isset($info['fileformat']) ? $info['fileformat'] : '') {
1421						case '':
1422						case 'id3':
1423						case 'ape':
1424						case 'mp3':
1425							$info['fileformat']          = 'mp3';
1426							$info['audio']['dataformat'] = 'mp3';
1427							break;
1428					}
1429					if (isset($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode']) && ($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode'] == 'vbr')) {
1430						if (!(abs($info['audio']['bitrate'] - $FirstFrameThisfileInfo['audio']['bitrate']) <= 1)) {
1431							// If there is garbage data between a valid VBR header frame and a sequence
1432							// of valid MPEG-audio frames the VBR data is no longer discarded.
1433							$info = $FirstFrameThisfileInfo;
1434							$info['avdataoffset']        = $FirstFrameAVDataOffset;
1435							$info['fileformat']          = 'mp3';
1436							$info['audio']['dataformat'] = 'mp3';
1437							$dummy                       = $info;
1438							unset($dummy['mpeg']['audio']);
1439							$GarbageOffsetStart = $FirstFrameAVDataOffset + $FirstFrameThisfileInfo['mpeg']['audio']['framelength'];
1440							$GarbageOffsetEnd   = $avdataoffset + $SynchSeekOffset;
1441							if ($this->decodeMPEGaudioHeader($GarbageOffsetEnd, $dummy, true, true)) {
1442								$info = $dummy;
1443								$info['avdataoffset'] = $GarbageOffsetEnd;
1444								$info['warning'][] = 'apparently-valid VBR header not used because could not find '.GETID3_MP3_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.'), but did find valid CBR stream starting at '.$GarbageOffsetEnd;
1445							} else {
1446								$info['warning'][] = 'using data from VBR header even though could not find '.GETID3_MP3_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.')';
1447							}
1448						}
1449					}
1450					if (isset($info['mpeg']['audio']['bitrate_mode']) && ($info['mpeg']['audio']['bitrate_mode'] == 'vbr') && !isset($info['mpeg']['audio']['VBR_method'])) {
1451						// VBR file with no VBR header
1452						$BitrateHistogram = true;
1453					}
1454
1455					if ($BitrateHistogram) {
1456
1457						$info['mpeg']['audio']['stereo_distribution']  = array('stereo'=>0, 'joint stereo'=>0, 'dual channel'=>0, 'mono'=>0);
1458						$info['mpeg']['audio']['version_distribution'] = array('1'=>0, '2'=>0, '2.5'=>0);
1459
1460						if ($info['mpeg']['audio']['version'] == '1') {
1461							if ($info['mpeg']['audio']['layer'] == 3) {
1462								$info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 40000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 320000=>0);
1463							} elseif ($info['mpeg']['audio']['layer'] == 2) {
1464								$info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 320000=>0, 384000=>0);
1465							} elseif ($info['mpeg']['audio']['layer'] == 1) {
1466								$info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 64000=>0, 96000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 288000=>0, 320000=>0, 352000=>0, 384000=>0, 416000=>0, 448000=>0);
1467							}
1468						} elseif ($info['mpeg']['audio']['layer'] == 1) {
1469							$info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 144000=>0, 160000=>0, 176000=>0, 192000=>0, 224000=>0, 256000=>0);
1470						} else {
1471							$info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 8000=>0, 16000=>0, 24000=>0, 32000=>0, 40000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 144000=>0, 160000=>0);
1472						}
1473
1474						$dummy = array('error'=>$info['error'], 'warning'=>$info['warning'], 'avdataend'=>$info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1475						$synchstartoffset = $info['avdataoffset'];
1476						fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
1477
1478						// you can play with these numbers:
1479						$max_frames_scan  = 50000;
1480						$max_scan_segments = 10;
1481
1482						// don't play with these numbers:
1483						$FastMode = false;
1484						$SynchErrorsFound = 0;
1485						$frames_scanned   = 0;
1486						$this_scan_segment = 0;
1487						$frames_scan_per_segment = ceil($max_frames_scan / $max_scan_segments);
1488						$pct_data_scanned = 0;
1489						for ($current_segment = 0; $current_segment < $max_scan_segments; $current_segment++) {
1490							$frames_scanned_this_segment = 0;
1491							if (ftell($this->getid3->fp) >= $info['avdataend']) {
1492								break;
1493							}
1494							$scan_start_offset[$current_segment] = max(ftell($this->getid3->fp), $info['avdataoffset'] + round($current_segment * (($info['avdataend'] - $info['avdataoffset']) / $max_scan_segments)));
1495							if ($current_segment > 0) {
1496								fseek($this->getid3->fp, $scan_start_offset[$current_segment], SEEK_SET);
1497								$buffer_4k = fread($this->getid3->fp, 4096);
1498								for ($j = 0; $j < (strlen($buffer_4k) - 4); $j++) {
1499									if (($buffer_4k{$j} == "\xFF") && ($buffer_4k{($j + 1)} > "\xE0")) { // synch detected
1500										if ($this->decodeMPEGaudioHeader($scan_start_offset[$current_segment] + $j, $dummy, false, false, $FastMode)) {
1501											$calculated_next_offset = $scan_start_offset[$current_segment] + $j + $dummy['mpeg']['audio']['framelength'];
1502											if ($this->decodeMPEGaudioHeader($calculated_next_offset, $dummy, false, false, $FastMode)) {
1503												$scan_start_offset[$current_segment] += $j;
1504												break;
1505											}
1506										}
1507									}
1508								}
1509							}
1510							$synchstartoffset = $scan_start_offset[$current_segment];
1511							while ($this->decodeMPEGaudioHeader($synchstartoffset, $dummy, false, false, $FastMode)) {
1512								$FastMode = true;
1513								$thisframebitrate = $MPEGaudioBitrateLookup[$MPEGaudioVersionLookup[$dummy['mpeg']['audio']['raw']['version']]][$MPEGaudioLayerLookup[$dummy['mpeg']['audio']['raw']['layer']]][$dummy['mpeg']['audio']['raw']['bitrate']];
1514
1515								if (empty($dummy['mpeg']['audio']['framelength'])) {
1516									$SynchErrorsFound++;
1517									$synchstartoffset++;
1518								} else {
1519									getid3_lib::safe_inc($info['mpeg']['audio']['bitrate_distribution'][$thisframebitrate]);
1520									getid3_lib::safe_inc($info['mpeg']['audio']['stereo_distribution'][$dummy['mpeg']['audio']['channelmode']]);
1521									getid3_lib::safe_inc($info['mpeg']['audio']['version_distribution'][$dummy['mpeg']['audio']['version']]);
1522									$synchstartoffset += $dummy['mpeg']['audio']['framelength'];
1523								}
1524								$frames_scanned++;
1525								if ($frames_scan_per_segment && (++$frames_scanned_this_segment >= $frames_scan_per_segment)) {
1526									$this_pct_scanned = (ftell($this->getid3->fp) - $scan_start_offset[$current_segment]) / ($info['avdataend'] - $info['avdataoffset']);
1527									if (($current_segment == 0) && (($this_pct_scanned * $max_scan_segments) >= 1)) {
1528										// file likely contains < $max_frames_scan, just scan as one segment
1529										$max_scan_segments = 1;
1530										$frames_scan_per_segment = $max_frames_scan;
1531									} else {
1532										$pct_data_scanned += $this_pct_scanned;
1533										break;
1534									}
1535								}
1536							}
1537						}
1538						if ($pct_data_scanned > 0) {
1539							$info['warning'][] = 'too many MPEG audio frames to scan, only scanned '.$frames_scanned.' frames in '.$max_scan_segments.' segments ('.number_format($pct_data_scanned * 100, 1).'% of file) and extrapolated distribution, playtime and bitrate may be incorrect.';
1540							foreach ($info['mpeg']['audio'] as $key1 => $value1) {
1541								if (!preg_match('#_distribution$#i', $key1)) {
1542									continue;
1543								}
1544								foreach ($value1 as $key2 => $value2) {
1545									$info['mpeg']['audio'][$key1][$key2] = round($value2 / $pct_data_scanned);
1546								}
1547							}
1548						}
1549
1550						if ($SynchErrorsFound > 0) {
1551							$info['warning'][] = 'Found '.$SynchErrorsFound.' synch errors in histogram analysis';
1552							//return false;
1553						}
1554
1555						$bittotal     = 0;
1556						$framecounter = 0;
1557						foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitratevalue => $bitratecount) {
1558							$framecounter += $bitratecount;
1559							if ($bitratevalue != 'free') {
1560								$bittotal += ($bitratevalue * $bitratecount);
1561							}
1562						}
1563						if ($framecounter == 0) {
1564							$info['error'][] = 'Corrupt MP3 file: framecounter == zero';
1565							return false;
1566						}
1567						$info['mpeg']['audio']['frame_count'] = getid3_lib::CastAsInt($framecounter);
1568						$info['mpeg']['audio']['bitrate']     = ($bittotal / $framecounter);
1569
1570						$info['audio']['bitrate'] = $info['mpeg']['audio']['bitrate'];
1571
1572
1573						// Definitively set VBR vs CBR, even if the Xing/LAME/VBRI header says differently
1574						$distinct_bitrates = 0;
1575						foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitrate_value => $bitrate_count) {
1576							if ($bitrate_count > 0) {
1577								$distinct_bitrates++;
1578							}
1579						}
1580						if ($distinct_bitrates > 1) {
1581							$info['mpeg']['audio']['bitrate_mode'] = 'vbr';
1582						} else {
1583							$info['mpeg']['audio']['bitrate_mode'] = 'cbr';
1584						}
1585						$info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
1586
1587					}
1588
1589					break; // exit while()
1590				}
1591			}
1592
1593			$SynchSeekOffset++;
1594			if (($avdataoffset + $SynchSeekOffset) >= $info['avdataend']) {
1595				// end of file/data
1596
1597				if (empty($info['mpeg']['audio'])) {
1598
1599					$info['error'][] = 'could not find valid MPEG synch before end of file';
1600					if (isset($info['audio']['bitrate'])) {
1601						unset($info['audio']['bitrate']);
1602					}
1603					if (isset($info['mpeg']['audio'])) {
1604						unset($info['mpeg']['audio']);
1605					}
1606					if (isset($info['mpeg']) && (!is_array($info['mpeg']) || empty($info['mpeg']))) {
1607						unset($info['mpeg']);
1608					}
1609					return false;
1610
1611				}
1612				break;
1613			}
1614
1615		}
1616		$info['audio']['channels']        = $info['mpeg']['audio']['channels'];
1617		$info['audio']['channelmode']     = $info['mpeg']['audio']['channelmode'];
1618		$info['audio']['sample_rate']     = $info['mpeg']['audio']['sample_rate'];
1619		return true;
1620	}
1621
1622
1623	static function MPEGaudioVersionArray() {
1624		static $MPEGaudioVersion = array('2.5', false, '2', '1');
1625		return $MPEGaudioVersion;
1626	}
1627
1628	static function MPEGaudioLayerArray() {
1629		static $MPEGaudioLayer = array(false, 3, 2, 1);
1630		return $MPEGaudioLayer;
1631	}
1632
1633	static function MPEGaudioBitrateArray() {
1634		static $MPEGaudioBitrate;
1635		if (empty($MPEGaudioBitrate)) {
1636			$MPEGaudioBitrate = array (
1637				'1'  =>  array (1 => array('free', 32000, 64000, 96000, 128000, 160000, 192000, 224000, 256000, 288000, 320000, 352000, 384000, 416000, 448000),
1638								2 => array('free', 32000, 48000, 56000,  64000,  80000,  96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000, 384000),
1639								3 => array('free', 32000, 40000, 48000,  56000,  64000,  80000,  96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000)
1640							   ),
1641
1642				'2'  =>  array (1 => array('free', 32000, 48000, 56000,  64000,  80000,  96000, 112000, 128000, 144000, 160000, 176000, 192000, 224000, 256000),
1643								2 => array('free',  8000, 16000, 24000,  32000,  40000,  48000,  56000,  64000,  80000,  96000, 112000, 128000, 144000, 160000),
1644							   )
1645			);
1646			$MPEGaudioBitrate['2'][3] = $MPEGaudioBitrate['2'][2];
1647			$MPEGaudioBitrate['2.5']  = $MPEGaudioBitrate['2'];
1648		}
1649		return $MPEGaudioBitrate;
1650	}
1651
1652	static function MPEGaudioFrequencyArray() {
1653		static $MPEGaudioFrequency;
1654		if (empty($MPEGaudioFrequency)) {
1655			$MPEGaudioFrequency = array (
1656				'1'   => array(44100, 48000, 32000),
1657				'2'   => array(22050, 24000, 16000),
1658				'2.5' => array(11025, 12000,  8000)
1659			);
1660		}
1661		return $MPEGaudioFrequency;
1662	}
1663
1664	static function MPEGaudioChannelModeArray() {
1665		static $MPEGaudioChannelMode = array('stereo', 'joint stereo', 'dual channel', 'mono');
1666		return $MPEGaudioChannelMode;
1667	}
1668
1669	static function MPEGaudioModeExtensionArray() {
1670		static $MPEGaudioModeExtension;
1671		if (empty($MPEGaudioModeExtension)) {
1672			$MPEGaudioModeExtension = array (
1673				1 => array('4-31', '8-31', '12-31', '16-31'),
1674				2 => array('4-31', '8-31', '12-31', '16-31'),
1675				3 => array('', 'IS', 'MS', 'IS+MS')
1676			);
1677		}
1678		return $MPEGaudioModeExtension;
1679	}
1680
1681	static function MPEGaudioEmphasisArray() {
1682		static $MPEGaudioEmphasis = array('none', '50/15ms', false, 'CCIT J.17');
1683		return $MPEGaudioEmphasis;
1684	}
1685
1686	static function MPEGaudioHeaderBytesValid($head4, $allowBitrate15=false) {
1687		return getid3_mp3::MPEGaudioHeaderValid(getid3_mp3::MPEGaudioHeaderDecode($head4), false, $allowBitrate15);
1688	}
1689
1690	static function MPEGaudioHeaderValid($rawarray, $echoerrors=false, $allowBitrate15=false) {
1691		if (($rawarray['synch'] & 0x0FFE) != 0x0FFE) {
1692			return false;
1693		}
1694
1695		static $MPEGaudioVersionLookup;
1696		static $MPEGaudioLayerLookup;
1697		static $MPEGaudioBitrateLookup;
1698		static $MPEGaudioFrequencyLookup;
1699		static $MPEGaudioChannelModeLookup;
1700		static $MPEGaudioModeExtensionLookup;
1701		static $MPEGaudioEmphasisLookup;
1702		if (empty($MPEGaudioVersionLookup)) {
1703			$MPEGaudioVersionLookup       = getid3_mp3::MPEGaudioVersionArray();
1704			$MPEGaudioLayerLookup         = getid3_mp3::MPEGaudioLayerArray();
1705			$MPEGaudioBitrateLookup       = getid3_mp3::MPEGaudioBitrateArray();
1706			$MPEGaudioFrequencyLookup     = getid3_mp3::MPEGaudioFrequencyArray();
1707			$MPEGaudioChannelModeLookup   = getid3_mp3::MPEGaudioChannelModeArray();
1708			$MPEGaudioModeExtensionLookup = getid3_mp3::MPEGaudioModeExtensionArray();
1709			$MPEGaudioEmphasisLookup      = getid3_mp3::MPEGaudioEmphasisArray();
1710		}
1711
1712		if (isset($MPEGaudioVersionLookup[$rawarray['version']])) {
1713			$decodedVersion = $MPEGaudioVersionLookup[$rawarray['version']];
1714		} else {
1715			echo ($echoerrors ? "\n".'invalid Version ('.$rawarray['version'].')' : '');
1716			return false;
1717		}
1718		if (isset($MPEGaudioLayerLookup[$rawarray['layer']])) {
1719			$decodedLayer = $MPEGaudioLayerLookup[$rawarray['layer']];
1720		} else {
1721			echo ($echoerrors ? "\n".'invalid Layer ('.$rawarray['layer'].')' : '');
1722			return false;
1723		}
1724		if (!isset($MPEGaudioBitrateLookup[$decodedVersion][$decodedLayer][$rawarray['bitrate']])) {
1725			echo ($echoerrors ? "\n".'invalid Bitrate ('.$rawarray['bitrate'].')' : '');
1726			if ($rawarray['bitrate'] == 15) {
1727				// known issue in LAME 3.90 - 3.93.1 where free-format has bitrate ID of 15 instead of 0
1728				// let it go through here otherwise file will not be identified
1729				if (!$allowBitrate15) {
1730					return false;
1731				}
1732			} else {
1733				return false;
1734			}
1735		}
1736		if (!isset($MPEGaudioFrequencyLookup[$decodedVersion][$rawarray['sample_rate']])) {
1737			echo ($echoerrors ? "\n".'invalid Frequency ('.$rawarray['sample_rate'].')' : '');
1738			return false;
1739		}
1740		if (!isset($MPEGaudioChannelModeLookup[$rawarray['channelmode']])) {
1741			echo ($echoerrors ? "\n".'invalid ChannelMode ('.$rawarray['channelmode'].')' : '');
1742			return false;
1743		}
1744		if (!isset($MPEGaudioModeExtensionLookup[$decodedLayer][$rawarray['modeextension']])) {
1745			echo ($echoerrors ? "\n".'invalid Mode Extension ('.$rawarray['modeextension'].')' : '');
1746			return false;
1747		}
1748		if (!isset($MPEGaudioEmphasisLookup[$rawarray['emphasis']])) {
1749			echo ($echoerrors ? "\n".'invalid Emphasis ('.$rawarray['emphasis'].')' : '');
1750			return false;
1751		}
1752		// These are just either set or not set, you can't mess that up :)
1753		// $rawarray['protection'];
1754		// $rawarray['padding'];
1755		// $rawarray['private'];
1756		// $rawarray['copyright'];
1757		// $rawarray['original'];
1758
1759		return true;
1760	}
1761
1762	static function MPEGaudioHeaderDecode($Header4Bytes) {
1763		// AAAA AAAA  AAAB BCCD  EEEE FFGH  IIJJ KLMM
1764		// A - Frame sync (all bits set)
1765		// B - MPEG Audio version ID
1766		// C - Layer description
1767		// D - Protection bit
1768		// E - Bitrate index
1769		// F - Sampling rate frequency index
1770		// G - Padding bit
1771		// H - Private bit
1772		// I - Channel Mode
1773		// J - Mode extension (Only if Joint stereo)
1774		// K - Copyright
1775		// L - Original
1776		// M - Emphasis
1777
1778		if (strlen($Header4Bytes) != 4) {
1779			return false;
1780		}
1781
1782		$MPEGrawHeader['synch']         = (getid3_lib::BigEndian2Int(substr($Header4Bytes, 0, 2)) & 0xFFE0) >> 4;
1783		$MPEGrawHeader['version']       = (ord($Header4Bytes{1}) & 0x18) >> 3; //    BB
1784		$MPEGrawHeader['layer']         = (ord($Header4Bytes{1}) & 0x06) >> 1; //      CC
1785		$MPEGrawHeader['protection']    = (ord($Header4Bytes{1}) & 0x01);      //        D
1786		$MPEGrawHeader['bitrate']       = (ord($Header4Bytes{2}) & 0xF0) >> 4; // EEEE
1787		$MPEGrawHeader['sample_rate']   = (ord($Header4Bytes{2}) & 0x0C) >> 2; //     FF
1788		$MPEGrawHeader['padding']       = (ord($Header4Bytes{2}) & 0x02) >> 1; //       G
1789		$MPEGrawHeader['private']       = (ord($Header4Bytes{2}) & 0x01);      //        H
1790		$MPEGrawHeader['channelmode']   = (ord($Header4Bytes{3}) & 0xC0) >> 6; // II
1791		$MPEGrawHeader['modeextension'] = (ord($Header4Bytes{3}) & 0x30) >> 4; //   JJ
1792		$MPEGrawHeader['copyright']     = (ord($Header4Bytes{3}) & 0x08) >> 3; //     K
1793		$MPEGrawHeader['original']      = (ord($Header4Bytes{3}) & 0x04) >> 2; //      L
1794		$MPEGrawHeader['emphasis']      = (ord($Header4Bytes{3}) & 0x03);      //       MM
1795
1796		return $MPEGrawHeader;
1797	}
1798
1799	static function MPEGaudioFrameLength(&$bitrate, &$version, &$layer, $padding, &$samplerate) {
1800		static $AudioFrameLengthCache = array();
1801
1802		if (!isset($AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate])) {
1803			$AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = false;
1804			if ($bitrate != 'free') {
1805
1806				if ($version == '1') {
1807
1808					if ($layer == '1') {
1809
1810						// For Layer I slot is 32 bits long
1811						$FrameLengthCoefficient = 48;
1812						$SlotLength = 4;
1813
1814					} else { // Layer 2 / 3
1815
1816						// for Layer 2 and Layer 3 slot is 8 bits long.
1817						$FrameLengthCoefficient = 144;
1818						$SlotLength = 1;
1819
1820					}
1821
1822				} else { // MPEG-2 / MPEG-2.5
1823
1824					if ($layer == '1') {
1825
1826						// For Layer I slot is 32 bits long
1827						$FrameLengthCoefficient = 24;
1828						$SlotLength = 4;
1829
1830					} elseif ($layer == '2') {
1831
1832						// for Layer 2 and Layer 3 slot is 8 bits long.
1833						$FrameLengthCoefficient = 144;
1834						$SlotLength = 1;
1835
1836					} else { // layer 3
1837
1838						// for Layer 2 and Layer 3 slot is 8 bits long.
1839						$FrameLengthCoefficient = 72;
1840						$SlotLength = 1;
1841
1842					}
1843
1844				}
1845
1846				// FrameLengthInBytes = ((Coefficient * BitRate) / SampleRate) + Padding
1847				if ($samplerate > 0) {
1848					$NewFramelength  = ($FrameLengthCoefficient * $bitrate) / $samplerate;
1849					$NewFramelength  = floor($NewFramelength / $SlotLength) * $SlotLength; // round to next-lower multiple of SlotLength (1 byte for Layer 2/3, 4 bytes for Layer I)
1850					if ($padding) {
1851						$NewFramelength += $SlotLength;
1852					}
1853					$AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = (int) $NewFramelength;
1854				}
1855			}
1856		}
1857		return $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate];
1858	}
1859
1860	static function ClosestStandardMP3Bitrate($bit_rate) {
1861		static $standard_bit_rates = array (320000, 256000, 224000, 192000, 160000, 128000, 112000, 96000, 80000, 64000, 56000, 48000, 40000, 32000, 24000, 16000, 8000);
1862		static $bit_rate_table = array (0=>'-');
1863		$round_bit_rate = intval(round($bit_rate, -3));
1864		if (!isset($bit_rate_table[$round_bit_rate])) {
1865			if ($round_bit_rate > max($standard_bit_rates)) {
1866				$bit_rate_table[$round_bit_rate] = round($bit_rate, 2 - strlen($bit_rate));
1867			} else {
1868				$bit_rate_table[$round_bit_rate] = max($standard_bit_rates);
1869				foreach ($standard_bit_rates as $standard_bit_rate) {
1870					if ($round_bit_rate >= $standard_bit_rate + (($bit_rate_table[$round_bit_rate] - $standard_bit_rate) / 2)) {
1871						break;
1872					}
1873					$bit_rate_table[$round_bit_rate] = $standard_bit_rate;
1874				}
1875			}
1876		}
1877		return $bit_rate_table[$round_bit_rate];
1878	}
1879
1880	static function XingVBRidOffset($version, $channelmode) {
1881		static $XingVBRidOffsetCache = array();
1882		if (empty($XingVBRidOffset)) {
1883			$XingVBRidOffset = array (
1884				'1'   => array ('mono'          => 0x15, // 4 + 17 = 21
1885								'stereo'        => 0x24, // 4 + 32 = 36
1886								'joint stereo'  => 0x24,
1887								'dual channel'  => 0x24
1888							   ),
1889
1890				'2'   => array ('mono'          => 0x0D, // 4 +  9 = 13
1891								'stereo'        => 0x15, // 4 + 17 = 21
1892								'joint stereo'  => 0x15,
1893								'dual channel'  => 0x15
1894							   ),
1895
1896				'2.5' => array ('mono'          => 0x15,
1897								'stereo'        => 0x15,
1898								'joint stereo'  => 0x15,
1899								'dual channel'  => 0x15
1900							   )
1901			);
1902		}
1903		return $XingVBRidOffset[$version][$channelmode];
1904	}
1905
1906	static function LAMEvbrMethodLookup($VBRmethodID) {
1907		static $LAMEvbrMethodLookup = array(
1908			0x00 => 'unknown',
1909			0x01 => 'cbr',
1910			0x02 => 'abr',
1911			0x03 => 'vbr-old / vbr-rh',
1912			0x04 => 'vbr-new / vbr-mtrh',
1913			0x05 => 'vbr-mt',
1914			0x06 => 'vbr (full vbr method 4)',
1915			0x08 => 'cbr (constant bitrate 2 pass)',
1916			0x09 => 'abr (2 pass)',
1917			0x0F => 'reserved'
1918		);
1919		return (isset($LAMEvbrMethodLookup[$VBRmethodID]) ? $LAMEvbrMethodLookup[$VBRmethodID] : '');
1920	}
1921
1922	static function LAMEmiscStereoModeLookup($StereoModeID) {
1923		static $LAMEmiscStereoModeLookup = array(
1924			0 => 'mono',
1925			1 => 'stereo',
1926			2 => 'dual mono',
1927			3 => 'joint stereo',
1928			4 => 'forced stereo',
1929			5 => 'auto',
1930			6 => 'intensity stereo',
1931			7 => 'other'
1932		);
1933		return (isset($LAMEmiscStereoModeLookup[$StereoModeID]) ? $LAMEmiscStereoModeLookup[$StereoModeID] : '');
1934	}
1935
1936	static function LAMEmiscSourceSampleFrequencyLookup($SourceSampleFrequencyID) {
1937		static $LAMEmiscSourceSampleFrequencyLookup = array(
1938			0 => '<= 32 kHz',
1939			1 => '44.1 kHz',
1940			2 => '48 kHz',
1941			3 => '> 48kHz'
1942		);
1943		return (isset($LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID]) ? $LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID] : '');
1944	}
1945
1946	static function LAMEsurroundInfoLookup($SurroundInfoID) {
1947		static $LAMEsurroundInfoLookup = array(
1948			0 => 'no surround info',
1949			1 => 'DPL encoding',
1950			2 => 'DPL2 encoding',
1951			3 => 'Ambisonic encoding'
1952		);
1953		return (isset($LAMEsurroundInfoLookup[$SurroundInfoID]) ? $LAMEsurroundInfoLookup[$SurroundInfoID] : 'reserved');
1954	}
1955
1956	static function LAMEpresetUsedLookup($LAMEtag) {
1957
1958		if ($LAMEtag['preset_used_id'] == 0) {
1959			// no preset used (LAME >=3.93)
1960			// no preset recorded (LAME <3.93)
1961			return '';
1962		}
1963		$LAMEpresetUsedLookup = array();
1964
1965		/////  THIS PART CANNOT BE STATIC .
1966		for ($i = 8; $i <= 320; $i++) {
1967			switch ($LAMEtag['vbr_method']) {
1968				case 'cbr':
1969					$LAMEpresetUsedLookup[$i] = '--alt-preset '.$LAMEtag['vbr_method'].' '.$i;
1970					break;
1971				case 'abr':
1972				default: // other VBR modes shouldn't be here(?)
1973					$LAMEpresetUsedLookup[$i] = '--alt-preset '.$i;
1974					break;
1975			}
1976		}
1977
1978		// named old-style presets (studio, phone, voice, etc) are handled in GuessEncoderOptions()
1979
1980		// named alt-presets
1981		$LAMEpresetUsedLookup[1000] = '--r3mix';
1982		$LAMEpresetUsedLookup[1001] = '--alt-preset standard';
1983		$LAMEpresetUsedLookup[1002] = '--alt-preset extreme';
1984		$LAMEpresetUsedLookup[1003] = '--alt-preset insane';
1985		$LAMEpresetUsedLookup[1004] = '--alt-preset fast standard';
1986		$LAMEpresetUsedLookup[1005] = '--alt-preset fast extreme';
1987		$LAMEpresetUsedLookup[1006] = '--alt-preset medium';
1988		$LAMEpresetUsedLookup[1007] = '--alt-preset fast medium';
1989
1990		// LAME 3.94 additions/changes
1991		$LAMEpresetUsedLookup[1010] = '--preset portable';                                                           // 3.94a15 Oct 21 2003
1992		$LAMEpresetUsedLookup[1015] = '--preset radio';                                                              // 3.94a15 Oct 21 2003
1993
1994		$LAMEpresetUsedLookup[320]  = '--preset insane';                                                             // 3.94a15 Nov 12 2003
1995		$LAMEpresetUsedLookup[410]  = '-V9';
1996		$LAMEpresetUsedLookup[420]  = '-V8';
1997		$LAMEpresetUsedLookup[440]  = '-V6';
1998		$LAMEpresetUsedLookup[430]  = '--preset radio';                                                              // 3.94a15 Nov 12 2003
1999		$LAMEpresetUsedLookup[450]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'portable';  // 3.94a15 Nov 12 2003
2000		$LAMEpresetUsedLookup[460]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'medium';    // 3.94a15 Nov 12 2003
2001		$LAMEpresetUsedLookup[470]  = '--r3mix';                                                                     // 3.94b1  Dec 18 2003
2002		$LAMEpresetUsedLookup[480]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'standard';  // 3.94a15 Nov 12 2003
2003		$LAMEpresetUsedLookup[490]  = '-V1';
2004		$LAMEpresetUsedLookup[500]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'extreme';   // 3.94a15 Nov 12 2003
2005
2006		return (isset($LAMEpresetUsedLookup[$LAMEtag['preset_used_id']]) ? $LAMEpresetUsedLookup[$LAMEtag['preset_used_id']] : 'new/unknown preset: '.$LAMEtag['preset_used_id'].' - report to info@getid3.org');
2007	}
2008
2009}
2010