1<?php
2
3/////////////////////////////////////////////////////////////////
4/// getID3() by James Heinrich <info@getid3.org>               //
5//  available at https://github.com/JamesHeinrich/getID3       //
6//            or https://www.getid3.org                        //
7//            or http://getid3.sourceforge.net                 //
8//  see readme.txt for more details                            //
9/////////////////////////////////////////////////////////////////
10//                                                             //
11// module.audio.mp3.php                                        //
12// module for analyzing MP3 files                              //
13// dependencies: NONE                                          //
14//                                                            ///
15/////////////////////////////////////////////////////////////////
16
17if (!defined('GETID3_INCLUDEPATH')) { // prevent path-exposing attacks that access modules directly on public webservers
18	exit;
19}
20
21// number of frames to scan to determine if MPEG-audio sequence is valid
22// Lower this number to 5-20 for faster scanning
23// Increase this number to 50+ for most accurate detection of valid VBR/CBR
24// mpeg-audio streams
25define('GETID3_MP3_VALID_CHECK_FRAMES', 35);
26
27
28class getid3_mp3 extends getid3_handler
29{
30	/**
31	 * Forces getID3() to scan the file byte-by-byte and log all the valid audio frame headers - extremely slow,
32	 * unrecommended, but may provide data from otherwise-unusable files.
33	 *
34	 * @var bool
35	 */
36	public $allow_bruteforce = false;
37
38	/**
39	 * @return bool
40	 */
41	public function Analyze() {
42		$info = &$this->getid3->info;
43
44		$initialOffset = $info['avdataoffset'];
45
46		if (!$this->getOnlyMPEGaudioInfo($info['avdataoffset'])) {
47			if ($this->allow_bruteforce) {
48				$this->error('Rescanning file in BruteForce mode');
49				$this->getOnlyMPEGaudioInfoBruteForce();
50			}
51		}
52
53
54		if (isset($info['mpeg']['audio']['bitrate_mode'])) {
55			$info['audio']['bitrate_mode'] = strtolower($info['mpeg']['audio']['bitrate_mode']);
56		}
57
58		if (((isset($info['id3v2']['headerlength']) && ($info['avdataoffset'] > $info['id3v2']['headerlength'])) || (!isset($info['id3v2']) && ($info['avdataoffset'] > 0) && ($info['avdataoffset'] != $initialOffset)))) {
59
60			$synchoffsetwarning = 'Unknown data before synch ';
61			if (isset($info['id3v2']['headerlength'])) {
62				$synchoffsetwarning .= '(ID3v2 header ends at '.$info['id3v2']['headerlength'].', then '.($info['avdataoffset'] - $info['id3v2']['headerlength']).' bytes garbage, ';
63			} elseif ($initialOffset > 0) {
64				$synchoffsetwarning .= '(should be at '.$initialOffset.', ';
65			} else {
66				$synchoffsetwarning .= '(should be at beginning of file, ';
67			}
68			$synchoffsetwarning .= 'synch detected at '.$info['avdataoffset'].')';
69			if (isset($info['audio']['bitrate_mode']) && ($info['audio']['bitrate_mode'] == 'cbr')) {
70
71				if (!empty($info['id3v2']['headerlength']) && (($info['avdataoffset'] - $info['id3v2']['headerlength']) == $info['mpeg']['audio']['framelength'])) {
72
73					$synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90-3.92) DLL in CBR mode.';
74					$info['audio']['codec'] = 'LAME';
75					$CurrentDataLAMEversionString = 'LAME3.';
76
77				} elseif (empty($info['id3v2']['headerlength']) && ($info['avdataoffset'] == $info['mpeg']['audio']['framelength'])) {
78
79					$synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90 - 3.92) DLL in CBR mode.';
80					$info['audio']['codec'] = 'LAME';
81					$CurrentDataLAMEversionString = 'LAME3.';
82
83				}
84
85			}
86			$this->warning($synchoffsetwarning);
87
88		}
89
90		if (isset($info['mpeg']['audio']['LAME'])) {
91			$info['audio']['codec'] = 'LAME';
92			if (!empty($info['mpeg']['audio']['LAME']['long_version'])) {
93				$info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['long_version'], "\x00");
94			} elseif (!empty($info['mpeg']['audio']['LAME']['short_version'])) {
95				$info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['short_version'], "\x00");
96			}
97		}
98
99		$CurrentDataLAMEversionString = (!empty($CurrentDataLAMEversionString) ? $CurrentDataLAMEversionString : (isset($info['audio']['encoder']) ? $info['audio']['encoder'] : ''));
100		if (!empty($CurrentDataLAMEversionString) && (substr($CurrentDataLAMEversionString, 0, 6) == 'LAME3.') && !preg_match('[0-9\)]', substr($CurrentDataLAMEversionString, -1))) {
101			// a version number of LAME that does not end with a number like "LAME3.92"
102			// or with a closing parenthesis like "LAME3.88 (alpha)"
103			// or a version of LAME with the LAMEtag-not-filled-in-DLL-mode bug (3.90-3.92)
104
105			// not sure what the actual last frame length will be, but will be less than or equal to 1441
106			$PossiblyLongerLAMEversion_FrameLength = 1441;
107
108			// Not sure what version of LAME this is - look in padding of last frame for longer version string
109			$PossibleLAMEversionStringOffset = $info['avdataend'] - $PossiblyLongerLAMEversion_FrameLength;
110			$this->fseek($PossibleLAMEversionStringOffset);
111			$PossiblyLongerLAMEversion_Data = $this->fread($PossiblyLongerLAMEversion_FrameLength);
112			switch (substr($CurrentDataLAMEversionString, -1)) {
113				case 'a':
114				case 'b':
115					// "LAME3.94a" will have a longer version string of "LAME3.94 (alpha)" for example
116					// need to trim off "a" to match longer string
117					$CurrentDataLAMEversionString = substr($CurrentDataLAMEversionString, 0, -1);
118					break;
119			}
120			if (($PossiblyLongerLAMEversion_String = strstr($PossiblyLongerLAMEversion_Data, $CurrentDataLAMEversionString)) !== false) {
121				if (substr($PossiblyLongerLAMEversion_String, 0, strlen($CurrentDataLAMEversionString)) == $CurrentDataLAMEversionString) {
122					$PossiblyLongerLAMEversion_NewString = substr($PossiblyLongerLAMEversion_String, 0, strspn($PossiblyLongerLAMEversion_String, 'LAME0123456789., (abcdefghijklmnopqrstuvwxyzJFSOND)')); //"LAME3.90.3"  "LAME3.87 (beta 1, Sep 27 2000)" "LAME3.88 (beta)"
123					if (empty($info['audio']['encoder']) || (strlen($PossiblyLongerLAMEversion_NewString) > strlen($info['audio']['encoder']))) {
124						$info['audio']['encoder'] = $PossiblyLongerLAMEversion_NewString;
125					}
126				}
127			}
128		}
129		if (!empty($info['audio']['encoder'])) {
130			$info['audio']['encoder'] = rtrim($info['audio']['encoder'], "\x00 ");
131		}
132
133		switch (isset($info['mpeg']['audio']['layer']) ? $info['mpeg']['audio']['layer'] : '') {
134			case 1:
135			case 2:
136				$info['audio']['dataformat'] = 'mp'.$info['mpeg']['audio']['layer'];
137				break;
138		}
139		if (isset($info['fileformat']) && ($info['fileformat'] == 'mp3')) {
140			switch ($info['audio']['dataformat']) {
141				case 'mp1':
142				case 'mp2':
143				case 'mp3':
144					$info['fileformat'] = $info['audio']['dataformat'];
145					break;
146
147				default:
148					$this->warning('Expecting [audio][dataformat] to be mp1/mp2/mp3 when fileformat == mp3, [audio][dataformat] actually "'.$info['audio']['dataformat'].'"');
149					break;
150			}
151		}
152
153		if (empty($info['fileformat'])) {
154			unset($info['fileformat']);
155			unset($info['audio']['bitrate_mode']);
156			unset($info['avdataoffset']);
157			unset($info['avdataend']);
158			return false;
159		}
160
161		$info['mime_type']         = 'audio/mpeg';
162		$info['audio']['lossless'] = false;
163
164		// Calculate playtime
165		if (!isset($info['playtime_seconds']) && isset($info['audio']['bitrate']) && ($info['audio']['bitrate'] > 0)) {
166			// https://github.com/JamesHeinrich/getID3/issues/161
167			// VBR header frame contains ~0.026s of silent audio data, but is not actually part of the original encoding and should be ignored
168			$xingVBRheaderFrameLength = ((isset($info['mpeg']['audio']['VBR_frames']) && isset($info['mpeg']['audio']['framelength'])) ? $info['mpeg']['audio']['framelength'] : 0);
169
170			$info['playtime_seconds'] = ($info['avdataend'] - $info['avdataoffset'] - $xingVBRheaderFrameLength) * 8 / $info['audio']['bitrate'];
171		}
172
173		$info['audio']['encoder_options'] = $this->GuessEncoderOptions();
174
175		return true;
176	}
177
178	/**
179	 * @return string
180	 */
181	public function GuessEncoderOptions() {
182		// shortcuts
183		$info = &$this->getid3->info;
184		$thisfile_mpeg_audio = array();
185		$thisfile_mpeg_audio_lame = array();
186		if (!empty($info['mpeg']['audio'])) {
187			$thisfile_mpeg_audio = &$info['mpeg']['audio'];
188			if (!empty($thisfile_mpeg_audio['LAME'])) {
189				$thisfile_mpeg_audio_lame = &$thisfile_mpeg_audio['LAME'];
190			}
191		}
192
193		$encoder_options = '';
194		static $NamedPresetBitrates = array(16, 24, 40, 56, 112, 128, 160, 192, 256);
195
196		if (isset($thisfile_mpeg_audio['VBR_method']) && ($thisfile_mpeg_audio['VBR_method'] == 'Fraunhofer') && !empty($thisfile_mpeg_audio['VBR_quality'])) {
197
198			$encoder_options = 'VBR q'.$thisfile_mpeg_audio['VBR_quality'];
199
200		} elseif (!empty($thisfile_mpeg_audio_lame['preset_used']) && isset($thisfile_mpeg_audio_lame['preset_used_id']) && (!in_array($thisfile_mpeg_audio_lame['preset_used_id'], $NamedPresetBitrates))) {
201
202			$encoder_options = $thisfile_mpeg_audio_lame['preset_used'];
203
204		} elseif (!empty($thisfile_mpeg_audio_lame['vbr_quality'])) {
205
206			static $KnownEncoderValues = array();
207			if (empty($KnownEncoderValues)) {
208
209				//$KnownEncoderValues[abrbitrate_minbitrate][vbr_quality][raw_vbr_method][raw_noise_shaping][raw_stereo_mode][ath_type][lowpass_frequency] = 'preset name';
210				$KnownEncoderValues[0xFF][58][1][1][3][2][20500] = '--alt-preset insane';        // 3.90,   3.90.1, 3.92
211				$KnownEncoderValues[0xFF][58][1][1][3][2][20600] = '--alt-preset insane';        // 3.90.2, 3.90.3, 3.91
212				$KnownEncoderValues[0xFF][57][1][1][3][4][20500] = '--alt-preset insane';        // 3.94,   3.95
213				$KnownEncoderValues['**'][78][3][2][3][2][19500] = '--alt-preset extreme';       // 3.90,   3.90.1, 3.92
214				$KnownEncoderValues['**'][78][3][2][3][2][19600] = '--alt-preset extreme';       // 3.90.2, 3.91
215				$KnownEncoderValues['**'][78][3][1][3][2][19600] = '--alt-preset extreme';       // 3.90.3
216				$KnownEncoderValues['**'][78][4][2][3][2][19500] = '--alt-preset fast extreme';  // 3.90,   3.90.1, 3.92
217				$KnownEncoderValues['**'][78][4][2][3][2][19600] = '--alt-preset fast extreme';  // 3.90.2, 3.90.3, 3.91
218				$KnownEncoderValues['**'][78][3][2][3][4][19000] = '--alt-preset standard';      // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
219				$KnownEncoderValues['**'][78][3][1][3][4][19000] = '--alt-preset standard';      // 3.90.3
220				$KnownEncoderValues['**'][78][4][2][3][4][19000] = '--alt-preset fast standard'; // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
221				$KnownEncoderValues['**'][78][4][1][3][4][19000] = '--alt-preset fast standard'; // 3.90.3
222				$KnownEncoderValues['**'][88][4][1][3][3][19500] = '--r3mix';                    // 3.90,   3.90.1, 3.92
223				$KnownEncoderValues['**'][88][4][1][3][3][19600] = '--r3mix';                    // 3.90.2, 3.90.3, 3.91
224				$KnownEncoderValues['**'][67][4][1][3][4][18000] = '--r3mix';                    // 3.94,   3.95
225				$KnownEncoderValues['**'][68][3][2][3][4][18000] = '--alt-preset medium';        // 3.90.3
226				$KnownEncoderValues['**'][68][4][2][3][4][18000] = '--alt-preset fast medium';   // 3.90.3
227
228				$KnownEncoderValues[0xFF][99][1][1][1][2][0]     = '--preset studio';            // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
229				$KnownEncoderValues[0xFF][58][2][1][3][2][20600] = '--preset studio';            // 3.90.3, 3.93.1
230				$KnownEncoderValues[0xFF][58][2][1][3][2][20500] = '--preset studio';            // 3.93
231				$KnownEncoderValues[0xFF][57][2][1][3][4][20500] = '--preset studio';            // 3.94,   3.95
232				$KnownEncoderValues[0xC0][88][1][1][1][2][0]     = '--preset cd';                // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
233				$KnownEncoderValues[0xC0][58][2][2][3][2][19600] = '--preset cd';                // 3.90.3, 3.93.1
234				$KnownEncoderValues[0xC0][58][2][2][3][2][19500] = '--preset cd';                // 3.93
235				$KnownEncoderValues[0xC0][57][2][1][3][4][19500] = '--preset cd';                // 3.94,   3.95
236				$KnownEncoderValues[0xA0][78][1][1][3][2][18000] = '--preset hifi';              // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
237				$KnownEncoderValues[0xA0][58][2][2][3][2][18000] = '--preset hifi';              // 3.90.3, 3.93,   3.93.1
238				$KnownEncoderValues[0xA0][57][2][1][3][4][18000] = '--preset hifi';              // 3.94,   3.95
239				$KnownEncoderValues[0x80][67][1][1][3][2][18000] = '--preset tape';              // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
240				$KnownEncoderValues[0x80][67][1][1][3][2][15000] = '--preset radio';             // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
241				$KnownEncoderValues[0x70][67][1][1][3][2][15000] = '--preset fm';                // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
242				$KnownEncoderValues[0x70][58][2][2][3][2][16000] = '--preset tape/radio/fm';     // 3.90.3, 3.93,   3.93.1
243				$KnownEncoderValues[0x70][57][2][1][3][4][16000] = '--preset tape/radio/fm';     // 3.94,   3.95
244				$KnownEncoderValues[0x38][58][2][2][0][2][10000] = '--preset voice';             // 3.90.3, 3.93,   3.93.1
245				$KnownEncoderValues[0x38][57][2][1][0][4][15000] = '--preset voice';             // 3.94,   3.95
246				$KnownEncoderValues[0x38][57][2][1][0][4][16000] = '--preset voice';             // 3.94a14
247				$KnownEncoderValues[0x28][65][1][1][0][2][7500]  = '--preset mw-us';             // 3.90,   3.90.1, 3.92
248				$KnownEncoderValues[0x28][65][1][1][0][2][7600]  = '--preset mw-us';             // 3.90.2, 3.91
249				$KnownEncoderValues[0x28][58][2][2][0][2][7000]  = '--preset mw-us';             // 3.90.3, 3.93,   3.93.1
250				$KnownEncoderValues[0x28][57][2][1][0][4][10500] = '--preset mw-us';             // 3.94,   3.95
251				$KnownEncoderValues[0x28][57][2][1][0][4][11200] = '--preset mw-us';             // 3.94a14
252				$KnownEncoderValues[0x28][57][2][1][0][4][8800]  = '--preset mw-us';             // 3.94a15
253				$KnownEncoderValues[0x18][58][2][2][0][2][4000]  = '--preset phon+/lw/mw-eu/sw'; // 3.90.3, 3.93.1
254				$KnownEncoderValues[0x18][58][2][2][0][2][3900]  = '--preset phon+/lw/mw-eu/sw'; // 3.93
255				$KnownEncoderValues[0x18][57][2][1][0][4][5900]  = '--preset phon+/lw/mw-eu/sw'; // 3.94,   3.95
256				$KnownEncoderValues[0x18][57][2][1][0][4][6200]  = '--preset phon+/lw/mw-eu/sw'; // 3.94a14
257				$KnownEncoderValues[0x18][57][2][1][0][4][3200]  = '--preset phon+/lw/mw-eu/sw'; // 3.94a15
258				$KnownEncoderValues[0x10][58][2][2][0][2][3800]  = '--preset phone';             // 3.90.3, 3.93.1
259				$KnownEncoderValues[0x10][58][2][2][0][2][3700]  = '--preset phone';             // 3.93
260				$KnownEncoderValues[0x10][57][2][1][0][4][5600]  = '--preset phone';             // 3.94,   3.95
261			}
262
263			if (isset($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']])) {
264
265				$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']];
266
267			} 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']])) {
268
269				$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']][$thisfile_mpeg_audio_lame['lowpass_frequency']];
270
271			} elseif ($info['audio']['bitrate_mode'] == 'vbr') {
272
273				// http://gabriel.mp3-tech.org/mp3infotag.html
274				// int    Quality = (100 - 10 * gfp->VBR_q - gfp->quality)h
275
276
277				$LAME_V_value = 10 - ceil($thisfile_mpeg_audio_lame['vbr_quality'] / 10);
278				$LAME_q_value = 100 - $thisfile_mpeg_audio_lame['vbr_quality'] - ($LAME_V_value * 10);
279				$encoder_options = '-V'.$LAME_V_value.' -q'.$LAME_q_value;
280
281			} elseif ($info['audio']['bitrate_mode'] == 'cbr') {
282
283				$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
284
285			} else {
286
287				$encoder_options = strtoupper($info['audio']['bitrate_mode']);
288
289			}
290
291		} elseif (!empty($thisfile_mpeg_audio_lame['bitrate_abr'])) {
292
293			$encoder_options = 'ABR'.$thisfile_mpeg_audio_lame['bitrate_abr'];
294
295		} elseif (!empty($info['audio']['bitrate'])) {
296
297			if ($info['audio']['bitrate_mode'] == 'cbr') {
298				$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
299			} else {
300				$encoder_options = strtoupper($info['audio']['bitrate_mode']);
301			}
302
303		}
304		if (!empty($thisfile_mpeg_audio_lame['bitrate_min'])) {
305			$encoder_options .= ' -b'.$thisfile_mpeg_audio_lame['bitrate_min'];
306		}
307
308		if (!empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev']) || !empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_next'])) {
309			$encoder_options .= ' --nogap';
310		}
311
312		if (!empty($thisfile_mpeg_audio_lame['lowpass_frequency'])) {
313			$ExplodedOptions = explode(' ', $encoder_options, 4);
314			if ($ExplodedOptions[0] == '--r3mix') {
315				$ExplodedOptions[1] = 'r3mix';
316			}
317			switch ($ExplodedOptions[0]) {
318				case '--preset':
319				case '--alt-preset':
320				case '--r3mix':
321					if ($ExplodedOptions[1] == 'fast') {
322						$ExplodedOptions[1] .= ' '.$ExplodedOptions[2];
323					}
324					switch ($ExplodedOptions[1]) {
325						case 'portable':
326						case 'medium':
327						case 'standard':
328						case 'extreme':
329						case 'insane':
330						case 'fast portable':
331						case 'fast medium':
332						case 'fast standard':
333						case 'fast extreme':
334						case 'fast insane':
335						case 'r3mix':
336							static $ExpectedLowpass = array(
337									'insane|20500'        => 20500,
338									'insane|20600'        => 20600,  // 3.90.2, 3.90.3, 3.91
339									'medium|18000'        => 18000,
340									'fast medium|18000'   => 18000,
341									'extreme|19500'       => 19500,  // 3.90,   3.90.1, 3.92, 3.95
342									'extreme|19600'       => 19600,  // 3.90.2, 3.90.3, 3.91, 3.93.1
343									'fast extreme|19500'  => 19500,  // 3.90,   3.90.1, 3.92, 3.95
344									'fast extreme|19600'  => 19600,  // 3.90.2, 3.90.3, 3.91, 3.93.1
345									'standard|19000'      => 19000,
346									'fast standard|19000' => 19000,
347									'r3mix|19500'         => 19500,  // 3.90,   3.90.1, 3.92
348									'r3mix|19600'         => 19600,  // 3.90.2, 3.90.3, 3.91
349									'r3mix|18000'         => 18000,  // 3.94,   3.95
350								);
351							if (!isset($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))) {
352								$encoder_options .= ' --lowpass '.$thisfile_mpeg_audio_lame['lowpass_frequency'];
353							}
354							break;
355
356						default:
357							break;
358					}
359					break;
360			}
361		}
362
363		if (isset($thisfile_mpeg_audio_lame['raw']['source_sample_freq'])) {
364			if (($thisfile_mpeg_audio['sample_rate'] == 44100) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 1)) {
365				$encoder_options .= ' --resample 44100';
366			} elseif (($thisfile_mpeg_audio['sample_rate'] == 48000) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 2)) {
367				$encoder_options .= ' --resample 48000';
368			} elseif ($thisfile_mpeg_audio['sample_rate'] < 44100) {
369				switch ($thisfile_mpeg_audio_lame['raw']['source_sample_freq']) {
370					case 0: // <= 32000
371						// may or may not be same as source frequency - ignore
372						break;
373					case 1: // 44100
374					case 2: // 48000
375					case 3: // 48000+
376						$ExplodedOptions = explode(' ', $encoder_options, 4);
377						switch ($ExplodedOptions[0]) {
378							case '--preset':
379							case '--alt-preset':
380								switch ($ExplodedOptions[1]) {
381									case 'fast':
382									case 'portable':
383									case 'medium':
384									case 'standard':
385									case 'extreme':
386									case 'insane':
387										$encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
388										break;
389
390									default:
391										static $ExpectedResampledRate = array(
392												'phon+/lw/mw-eu/sw|16000' => 16000,
393												'mw-us|24000'             => 24000, // 3.95
394												'mw-us|32000'             => 32000, // 3.93
395												'mw-us|16000'             => 16000, // 3.92
396												'phone|16000'             => 16000,
397												'phone|11025'             => 11025, // 3.94a15
398												'radio|32000'             => 32000, // 3.94a15
399												'fm/radio|32000'          => 32000, // 3.92
400												'fm|32000'                => 32000, // 3.90
401												'voice|32000'             => 32000);
402										if (!isset($ExpectedResampledRate[$ExplodedOptions[1].'|'.$thisfile_mpeg_audio['sample_rate']])) {
403											$encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
404										}
405										break;
406								}
407								break;
408
409							case '--r3mix':
410							default:
411								$encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
412								break;
413						}
414						break;
415				}
416			}
417		}
418		if (empty($encoder_options) && !empty($info['audio']['bitrate']) && !empty($info['audio']['bitrate_mode'])) {
419			//$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
420			$encoder_options = strtoupper($info['audio']['bitrate_mode']);
421		}
422
423		return $encoder_options;
424	}
425
426	/**
427	 * @param int   $offset
428	 * @param array $info
429	 * @param bool  $recursivesearch
430	 * @param bool  $ScanAsCBR
431	 * @param bool  $FastMPEGheaderScan
432	 *
433	 * @return bool
434	 */
435	public function decodeMPEGaudioHeader($offset, &$info, $recursivesearch=true, $ScanAsCBR=false, $FastMPEGheaderScan=false) {
436		static $MPEGaudioVersionLookup;
437		static $MPEGaudioLayerLookup;
438		static $MPEGaudioBitrateLookup;
439		static $MPEGaudioFrequencyLookup;
440		static $MPEGaudioChannelModeLookup;
441		static $MPEGaudioModeExtensionLookup;
442		static $MPEGaudioEmphasisLookup;
443		if (empty($MPEGaudioVersionLookup)) {
444			$MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();
445			$MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();
446			$MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();
447			$MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();
448			$MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();
449			$MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
450			$MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();
451		}
452
453		if ($this->fseek($offset) != 0) {
454			$this->error('decodeMPEGaudioHeader() failed to seek to next offset at '.$offset);
455			return false;
456		}
457		//$headerstring = $this->fread(1441); // worst-case max length = 32kHz @ 320kbps layer 3 = 1441 bytes/frame
458		$headerstring = $this->fread(226); // LAME header at offset 36 + 190 bytes of Xing/LAME data
459
460		// MP3 audio frame structure:
461		// $aa $aa $aa $aa [$bb $bb] $cc...
462		// where $aa..$aa is the four-byte mpeg-audio header (below)
463		// $bb $bb is the optional 2-byte CRC
464		// and $cc... is the audio data
465
466		$head4 = substr($headerstring, 0, 4);
467		$head4_key = getid3_lib::PrintHexBytes($head4, true, false, false);
468		static $MPEGaudioHeaderDecodeCache = array();
469		if (isset($MPEGaudioHeaderDecodeCache[$head4_key])) {
470			$MPEGheaderRawArray = $MPEGaudioHeaderDecodeCache[$head4_key];
471		} else {
472			$MPEGheaderRawArray = self::MPEGaudioHeaderDecode($head4);
473			$MPEGaudioHeaderDecodeCache[$head4_key] = $MPEGheaderRawArray;
474		}
475
476		static $MPEGaudioHeaderValidCache = array();
477		if (!isset($MPEGaudioHeaderValidCache[$head4_key])) { // Not in cache
478			//$MPEGaudioHeaderValidCache[$head4_key] = self::MPEGaudioHeaderValid($MPEGheaderRawArray, false, true);  // allow badly-formatted freeformat (from LAME 3.90 - 3.93.1)
479			$MPEGaudioHeaderValidCache[$head4_key] = self::MPEGaudioHeaderValid($MPEGheaderRawArray, false, false);
480		}
481
482		// shortcut
483		if (!isset($info['mpeg']['audio'])) {
484			$info['mpeg']['audio'] = array();
485		}
486		$thisfile_mpeg_audio = &$info['mpeg']['audio'];
487
488		if ($MPEGaudioHeaderValidCache[$head4_key]) {
489			$thisfile_mpeg_audio['raw'] = $MPEGheaderRawArray;
490		} else {
491			$this->error('Invalid MPEG audio header ('.getid3_lib::PrintHexBytes($head4).') at offset '.$offset);
492			return false;
493		}
494
495		if (!$FastMPEGheaderScan) {
496			$thisfile_mpeg_audio['version']       = $MPEGaudioVersionLookup[$thisfile_mpeg_audio['raw']['version']];
497			$thisfile_mpeg_audio['layer']         = $MPEGaudioLayerLookup[$thisfile_mpeg_audio['raw']['layer']];
498
499			$thisfile_mpeg_audio['channelmode']   = $MPEGaudioChannelModeLookup[$thisfile_mpeg_audio['raw']['channelmode']];
500			$thisfile_mpeg_audio['channels']      = (($thisfile_mpeg_audio['channelmode'] == 'mono') ? 1 : 2);
501			$thisfile_mpeg_audio['sample_rate']   = $MPEGaudioFrequencyLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['raw']['sample_rate']];
502			$thisfile_mpeg_audio['protection']    = !$thisfile_mpeg_audio['raw']['protection'];
503			$thisfile_mpeg_audio['private']       = (bool) $thisfile_mpeg_audio['raw']['private'];
504			$thisfile_mpeg_audio['modeextension'] = $MPEGaudioModeExtensionLookup[$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['modeextension']];
505			$thisfile_mpeg_audio['copyright']     = (bool) $thisfile_mpeg_audio['raw']['copyright'];
506			$thisfile_mpeg_audio['original']      = (bool) $thisfile_mpeg_audio['raw']['original'];
507			$thisfile_mpeg_audio['emphasis']      = $MPEGaudioEmphasisLookup[$thisfile_mpeg_audio['raw']['emphasis']];
508
509			$info['audio']['channels']    = $thisfile_mpeg_audio['channels'];
510			$info['audio']['sample_rate'] = $thisfile_mpeg_audio['sample_rate'];
511
512			if ($thisfile_mpeg_audio['protection']) {
513				$thisfile_mpeg_audio['crc'] = getid3_lib::BigEndian2Int(substr($headerstring, 4, 2));
514			}
515		}
516
517		if ($thisfile_mpeg_audio['raw']['bitrate'] == 15) {
518			// http://www.hydrogenaudio.org/?act=ST&f=16&t=9682&st=0
519			$this->warning('Invalid bitrate index (15), this is a known bug in free-format MP3s encoded by LAME v3.90 - 3.93.1');
520			$thisfile_mpeg_audio['raw']['bitrate'] = 0;
521		}
522		$thisfile_mpeg_audio['padding'] = (bool) $thisfile_mpeg_audio['raw']['padding'];
523		$thisfile_mpeg_audio['bitrate'] = $MPEGaudioBitrateLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['bitrate']];
524
525		if (($thisfile_mpeg_audio['bitrate'] == 'free') && ($offset == $info['avdataoffset'])) {
526			// only skip multiple frame check if free-format bitstream found at beginning of file
527			// otherwise is quite possibly simply corrupted data
528			$recursivesearch = false;
529		}
530
531		// For Layer 2 there are some combinations of bitrate and mode which are not allowed.
532		if (!$FastMPEGheaderScan && ($thisfile_mpeg_audio['layer'] == '2')) {
533
534			$info['audio']['dataformat'] = 'mp2';
535			switch ($thisfile_mpeg_audio['channelmode']) {
536
537				case 'mono':
538					if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] <= 192000)) {
539						// these are ok
540					} else {
541						$this->error($thisfile_mpeg_audio['bitrate'].'kbps not allowed in Layer 2, '.$thisfile_mpeg_audio['channelmode'].'.');
542						return false;
543					}
544					break;
545
546				case 'stereo':
547				case 'joint stereo':
548				case 'dual channel':
549					if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] == 64000) || ($thisfile_mpeg_audio['bitrate'] >= 96000)) {
550						// these are ok
551					} else {
552						$this->error(intval(round($thisfile_mpeg_audio['bitrate'] / 1000)).'kbps not allowed in Layer 2, '.$thisfile_mpeg_audio['channelmode'].'.');
553						return false;
554					}
555					break;
556
557			}
558
559		}
560
561
562		if ($info['audio']['sample_rate'] > 0) {
563			$thisfile_mpeg_audio['framelength'] = self::MPEGaudioFrameLength($thisfile_mpeg_audio['bitrate'], $thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['layer'], (int) $thisfile_mpeg_audio['padding'], $info['audio']['sample_rate']);
564		}
565
566		$nextframetestoffset = $offset + 1;
567		if ($thisfile_mpeg_audio['bitrate'] != 'free') {
568
569			$info['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];
570
571			if (isset($thisfile_mpeg_audio['framelength'])) {
572				$nextframetestoffset = $offset + $thisfile_mpeg_audio['framelength'];
573			} else {
574				$this->error('Frame at offset('.$offset.') is has an invalid frame length.');
575				return false;
576			}
577
578		}
579
580		$ExpectedNumberOfAudioBytes = 0;
581
582		////////////////////////////////////////////////////////////////////////////////////
583		// Variable-bitrate headers
584
585		if (substr($headerstring, 4 + 32, 4) == 'VBRI') {
586			// Fraunhofer VBR header is hardcoded 'VBRI' at offset 0x24 (36)
587			// specs taken from http://minnie.tuhs.org/pipermail/mp3encoder/2001-January/001800.html
588
589			$thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
590			$thisfile_mpeg_audio['VBR_method']   = 'Fraunhofer';
591			$info['audio']['codec']              = 'Fraunhofer';
592
593			$SideInfoData = substr($headerstring, 4 + 2, 32);
594
595			$FraunhoferVBROffset = 36;
596
597			$thisfile_mpeg_audio['VBR_encoder_version']     = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  4, 2)); // VbriVersion
598			$thisfile_mpeg_audio['VBR_encoder_delay']       = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  6, 2)); // VbriDelay
599			$thisfile_mpeg_audio['VBR_quality']             = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  8, 2)); // VbriQuality
600			$thisfile_mpeg_audio['VBR_bytes']               = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 10, 4)); // VbriStreamBytes
601			$thisfile_mpeg_audio['VBR_frames']              = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 14, 4)); // VbriStreamFrames
602			$thisfile_mpeg_audio['VBR_seek_offsets']        = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 18, 2)); // VbriTableSize
603			$thisfile_mpeg_audio['VBR_seek_scale']          = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 20, 2)); // VbriTableScale
604			$thisfile_mpeg_audio['VBR_entry_bytes']         = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 22, 2)); // VbriEntryBytes
605			$thisfile_mpeg_audio['VBR_entry_frames']        = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 24, 2)); // VbriEntryFrames
606
607			$ExpectedNumberOfAudioBytes = $thisfile_mpeg_audio['VBR_bytes'];
608
609			$previousbyteoffset = $offset;
610			for ($i = 0; $i < $thisfile_mpeg_audio['VBR_seek_offsets']; $i++) {
611				$Fraunhofer_OffsetN = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset, $thisfile_mpeg_audio['VBR_entry_bytes']));
612				$FraunhoferVBROffset += $thisfile_mpeg_audio['VBR_entry_bytes'];
613				$thisfile_mpeg_audio['VBR_offsets_relative'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']);
614				$thisfile_mpeg_audio['VBR_offsets_absolute'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']) + $previousbyteoffset;
615				$previousbyteoffset += $Fraunhofer_OffsetN;
616			}
617
618
619		} else {
620
621			// Xing VBR header is hardcoded 'Xing' at a offset 0x0D (13), 0x15 (21) or 0x24 (36)
622			// depending on MPEG layer and number of channels
623
624			$VBRidOffset = self::XingVBRidOffset($thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['channelmode']);
625			$SideInfoData = substr($headerstring, 4 + 2, $VBRidOffset - 4);
626
627			if ((substr($headerstring, $VBRidOffset, strlen('Xing')) == 'Xing') || (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Info')) {
628				// 'Xing' is traditional Xing VBR frame
629				// 'Info' is LAME-encoded CBR (This was done to avoid CBR files to be recognized as traditional Xing VBR files by some decoders.)
630				// 'Info' *can* legally be used to specify a VBR file as well, however.
631
632				// http://www.multiweb.cz/twoinches/MP3inside.htm
633				//00..03 = "Xing" or "Info"
634				//04..07 = Flags:
635				//  0x01  Frames Flag     set if value for number of frames in file is stored
636				//  0x02  Bytes Flag      set if value for filesize in bytes is stored
637				//  0x04  TOC Flag        set if values for TOC are stored
638				//  0x08  VBR Scale Flag  set if values for VBR scale is stored
639				//08..11  Frames: Number of frames in file (including the first Xing/Info one)
640				//12..15  Bytes:  File length in Bytes
641				//16..115  TOC (Table of Contents):
642				//  Contains of 100 indexes (one Byte length) for easier lookup in file. Approximately solves problem with moving inside file.
643				//  Each Byte has a value according this formula:
644				//  (TOC[i] / 256) * fileLenInBytes
645				//  So if song lasts eg. 240 sec. and you want to jump to 60. sec. (and file is 5 000 000 Bytes length) you can use:
646				//  TOC[(60/240)*100] = TOC[25]
647				//  and corresponding Byte in file is then approximately at:
648				//  (TOC[25]/256) * 5000000
649				//116..119  VBR Scale
650
651
652				// should be safe to leave this at 'vbr' and let it be overriden to 'cbr' if a CBR preset/mode is used by LAME
653//				if (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Xing') {
654					$thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
655					$thisfile_mpeg_audio['VBR_method']   = 'Xing';
656//				} else {
657//					$ScanAsCBR = true;
658//					$thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
659//				}
660
661				$thisfile_mpeg_audio['xing_flags_raw'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 4, 4));
662
663				$thisfile_mpeg_audio['xing_flags']['frames']    = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000001);
664				$thisfile_mpeg_audio['xing_flags']['bytes']     = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000002);
665				$thisfile_mpeg_audio['xing_flags']['toc']       = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000004);
666				$thisfile_mpeg_audio['xing_flags']['vbr_scale'] = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000008);
667
668				if ($thisfile_mpeg_audio['xing_flags']['frames']) {
669					$thisfile_mpeg_audio['VBR_frames'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset +  8, 4));
670					//$thisfile_mpeg_audio['VBR_frames']--; // don't count header Xing/Info frame
671				}
672				if ($thisfile_mpeg_audio['xing_flags']['bytes']) {
673					$thisfile_mpeg_audio['VBR_bytes']  = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 12, 4));
674				}
675
676				//if (($thisfile_mpeg_audio['bitrate'] == 'free') && !empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {
677				//if (!empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {
678				if (!empty($thisfile_mpeg_audio['VBR_frames'])) {
679					$used_filesize  = 0;
680					if (!empty($thisfile_mpeg_audio['VBR_bytes'])) {
681						$used_filesize = $thisfile_mpeg_audio['VBR_bytes'];
682					} elseif (!empty($info['filesize'])) {
683						$used_filesize  = $info['filesize'];
684						$used_filesize -= (isset($info['id3v2']['headerlength']) ? intval($info['id3v2']['headerlength']) : 0);
685						$used_filesize -= (isset($info['id3v1']) ? 128 : 0);
686						$used_filesize -= (isset($info['tag_offset_end']) ? $info['tag_offset_end'] - $info['tag_offset_start'] : 0);
687						$this->warning('MP3.Xing header missing VBR_bytes, assuming MPEG audio portion of file is '.number_format($used_filesize).' bytes');
688					}
689
690					$framelengthfloat = $used_filesize / $thisfile_mpeg_audio['VBR_frames'];
691
692					if ($thisfile_mpeg_audio['layer'] == '1') {
693						// BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
694						//$info['audio']['bitrate'] = ((($framelengthfloat / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
695						$info['audio']['bitrate'] = ($framelengthfloat / 4) * $thisfile_mpeg_audio['sample_rate'] * (2 / $info['audio']['channels']) / 12;
696					} else {
697						// Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
698						//$info['audio']['bitrate'] = (($framelengthfloat - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
699						$info['audio']['bitrate'] = $framelengthfloat * $thisfile_mpeg_audio['sample_rate'] * (2 / $info['audio']['channels']) / 144;
700					}
701					$thisfile_mpeg_audio['framelength'] = floor($framelengthfloat);
702				}
703
704				if ($thisfile_mpeg_audio['xing_flags']['toc']) {
705					$LAMEtocData = substr($headerstring, $VBRidOffset + 16, 100);
706					for ($i = 0; $i < 100; $i++) {
707						$thisfile_mpeg_audio['toc'][$i] = ord($LAMEtocData[$i]);
708					}
709				}
710				if ($thisfile_mpeg_audio['xing_flags']['vbr_scale']) {
711					$thisfile_mpeg_audio['VBR_scale'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 116, 4));
712				}
713
714
715				// http://gabriel.mp3-tech.org/mp3infotag.html
716				if (substr($headerstring, $VBRidOffset + 120, 4) == 'LAME') {
717
718					// shortcut
719					$thisfile_mpeg_audio['LAME'] = array();
720					$thisfile_mpeg_audio_lame    = &$thisfile_mpeg_audio['LAME'];
721
722
723					$thisfile_mpeg_audio_lame['long_version']  = substr($headerstring, $VBRidOffset + 120, 20);
724					$thisfile_mpeg_audio_lame['short_version'] = substr($thisfile_mpeg_audio_lame['long_version'], 0, 9);
725					$thisfile_mpeg_audio_lame['numeric_version'] = str_replace('LAME', '', $thisfile_mpeg_audio_lame['short_version']);
726					if (preg_match('#^LAME([0-9\\.a-z]+)#', $thisfile_mpeg_audio_lame['long_version'], $matches)) {
727						$thisfile_mpeg_audio_lame['short_version']   = $matches[0];
728						$thisfile_mpeg_audio_lame['numeric_version'] = $matches[1];
729					}
730					foreach (explode('.', $thisfile_mpeg_audio_lame['numeric_version']) as $key => $number) {
731						$thisfile_mpeg_audio_lame['integer_version'][$key] = intval($number);
732					}
733
734					//if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.90') {
735					if ((($thisfile_mpeg_audio_lame['integer_version'][0] * 1000) + $thisfile_mpeg_audio_lame['integer_version'][1]) >= 3090) { // cannot use string version compare, may have "LAME3.90" or "LAME3.100" -- see https://github.com/JamesHeinrich/getID3/issues/207
736
737						// extra 11 chars are not part of version string when LAMEtag present
738						unset($thisfile_mpeg_audio_lame['long_version']);
739
740						// It the LAME tag was only introduced in LAME v3.90
741						// http://www.hydrogenaudio.org/?act=ST&f=15&t=9933
742
743						// Offsets of various bytes in http://gabriel.mp3-tech.org/mp3infotag.html
744						// are assuming a 'Xing' identifier offset of 0x24, which is the case for
745						// MPEG-1 non-mono, but not for other combinations
746						$LAMEtagOffsetContant = $VBRidOffset - 0x24;
747
748						// shortcuts
749						$thisfile_mpeg_audio_lame['RGAD']    = array('track'=>array(), 'album'=>array());
750						$thisfile_mpeg_audio_lame_RGAD       = &$thisfile_mpeg_audio_lame['RGAD'];
751						$thisfile_mpeg_audio_lame_RGAD_track = &$thisfile_mpeg_audio_lame_RGAD['track'];
752						$thisfile_mpeg_audio_lame_RGAD_album = &$thisfile_mpeg_audio_lame_RGAD['album'];
753						$thisfile_mpeg_audio_lame['raw'] = array();
754						$thisfile_mpeg_audio_lame_raw    = &$thisfile_mpeg_audio_lame['raw'];
755
756						// byte $9B  VBR Quality
757						// This field is there to indicate a quality level, although the scale was not precised in the original Xing specifications.
758						// Actually overwrites original Xing bytes
759						unset($thisfile_mpeg_audio['VBR_scale']);
760						$thisfile_mpeg_audio_lame['vbr_quality'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0x9B, 1));
761
762						// bytes $9C-$A4  Encoder short VersionString
763						$thisfile_mpeg_audio_lame['short_version'] = substr($headerstring, $LAMEtagOffsetContant + 0x9C, 9);
764
765						// byte $A5  Info Tag revision + VBR method
766						$LAMEtagRevisionVBRmethod = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA5, 1));
767
768						$thisfile_mpeg_audio_lame['tag_revision']   = ($LAMEtagRevisionVBRmethod & 0xF0) >> 4;
769						$thisfile_mpeg_audio_lame_raw['vbr_method'] =  $LAMEtagRevisionVBRmethod & 0x0F;
770						$thisfile_mpeg_audio_lame['vbr_method']     = self::LAMEvbrMethodLookup($thisfile_mpeg_audio_lame_raw['vbr_method']);
771						$thisfile_mpeg_audio['bitrate_mode']        = substr($thisfile_mpeg_audio_lame['vbr_method'], 0, 3); // usually either 'cbr' or 'vbr', but truncates 'vbr-old / vbr-rh' to 'vbr'
772
773						// byte $A6  Lowpass filter value
774						$thisfile_mpeg_audio_lame['lowpass_frequency'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA6, 1)) * 100;
775
776						// bytes $A7-$AE  Replay Gain
777						// http://privatewww.essex.ac.uk/~djmrob/replaygain/rg_data_format.html
778						// bytes $A7-$AA : 32 bit floating point "Peak signal amplitude"
779						if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.94b') {
780							// LAME 3.94a16 and later - 9.23 fixed point
781							// ie 0x0059E2EE / (2^23) = 5890798 / 8388608 = 0.7022378444671630859375
782							$thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = (float) ((getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4))) / 8388608);
783						} else {
784							// LAME 3.94a15 and earlier - 32-bit floating point
785							// Actually 3.94a16 will fall in here too and be WRONG, but is hard to detect 3.94a16 vs 3.94a15
786							$thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = getid3_lib::LittleEndian2Float(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4));
787						}
788						if ($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] == 0) {
789							unset($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);
790						} else {
791							$thisfile_mpeg_audio_lame_RGAD['peak_db'] = getid3_lib::RGADamplitude2dB($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);
792						}
793
794						$thisfile_mpeg_audio_lame_raw['RGAD_track']      =   getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAB, 2));
795						$thisfile_mpeg_audio_lame_raw['RGAD_album']      =   getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAD, 2));
796
797
798						if ($thisfile_mpeg_audio_lame_raw['RGAD_track'] != 0) {
799
800							$thisfile_mpeg_audio_lame_RGAD_track['raw']['name']        = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0xE000) >> 13;
801							$thisfile_mpeg_audio_lame_RGAD_track['raw']['originator']  = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x1C00) >> 10;
802							$thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit']    = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x0200) >> 9;
803							$thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'] =  $thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x01FF;
804							$thisfile_mpeg_audio_lame_RGAD_track['name']       = getid3_lib::RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['name']);
805							$thisfile_mpeg_audio_lame_RGAD_track['originator'] = getid3_lib::RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['originator']);
806							$thisfile_mpeg_audio_lame_RGAD_track['gain_db']    = getid3_lib::RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit']);
807
808							if (!empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'])) {
809								$info['replay_gain']['track']['peak']   = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];
810							}
811							$info['replay_gain']['track']['originator'] = $thisfile_mpeg_audio_lame_RGAD_track['originator'];
812							$info['replay_gain']['track']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_track['gain_db'];
813						} else {
814							unset($thisfile_mpeg_audio_lame_RGAD['track']);
815						}
816						if ($thisfile_mpeg_audio_lame_raw['RGAD_album'] != 0) {
817
818							$thisfile_mpeg_audio_lame_RGAD_album['raw']['name']        = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0xE000) >> 13;
819							$thisfile_mpeg_audio_lame_RGAD_album['raw']['originator']  = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x1C00) >> 10;
820							$thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit']    = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x0200) >> 9;
821							$thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'] = $thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x01FF;
822							$thisfile_mpeg_audio_lame_RGAD_album['name']       = getid3_lib::RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['name']);
823							$thisfile_mpeg_audio_lame_RGAD_album['originator'] = getid3_lib::RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['originator']);
824							$thisfile_mpeg_audio_lame_RGAD_album['gain_db']    = getid3_lib::RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit']);
825
826							if (!empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'])) {
827								$info['replay_gain']['album']['peak']   = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];
828							}
829							$info['replay_gain']['album']['originator'] = $thisfile_mpeg_audio_lame_RGAD_album['originator'];
830							$info['replay_gain']['album']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_album['gain_db'];
831						} else {
832							unset($thisfile_mpeg_audio_lame_RGAD['album']);
833						}
834						if (empty($thisfile_mpeg_audio_lame_RGAD)) {
835							unset($thisfile_mpeg_audio_lame['RGAD']);
836						}
837
838
839						// byte $AF  Encoding flags + ATH Type
840						$EncodingFlagsATHtype = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAF, 1));
841						$thisfile_mpeg_audio_lame['encoding_flags']['nspsytune']   = (bool) ($EncodingFlagsATHtype & 0x10);
842						$thisfile_mpeg_audio_lame['encoding_flags']['nssafejoint'] = (bool) ($EncodingFlagsATHtype & 0x20);
843						$thisfile_mpeg_audio_lame['encoding_flags']['nogap_next']  = (bool) ($EncodingFlagsATHtype & 0x40);
844						$thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev']  = (bool) ($EncodingFlagsATHtype & 0x80);
845						$thisfile_mpeg_audio_lame['ath_type']                      =         $EncodingFlagsATHtype & 0x0F;
846
847						// byte $B0  if ABR {specified bitrate} else {minimal bitrate}
848						$thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB0, 1));
849						if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 2) { // Average BitRate (ABR)
850							$thisfile_mpeg_audio_lame['bitrate_abr'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];
851						} elseif ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1) { // Constant BitRate (CBR)
852							// ignore
853						} elseif ($thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] > 0) { // Variable BitRate (VBR) - minimum bitrate
854							$thisfile_mpeg_audio_lame['bitrate_min'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];
855						}
856
857						// bytes $B1-$B3  Encoder delays
858						$EncoderDelays = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB1, 3));
859						$thisfile_mpeg_audio_lame['encoder_delay'] = ($EncoderDelays & 0xFFF000) >> 12;
860						$thisfile_mpeg_audio_lame['end_padding']   =  $EncoderDelays & 0x000FFF;
861
862						// byte $B4  Misc
863						$MiscByte = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB4, 1));
864						$thisfile_mpeg_audio_lame_raw['noise_shaping']       = ($MiscByte & 0x03);
865						$thisfile_mpeg_audio_lame_raw['stereo_mode']         = ($MiscByte & 0x1C) >> 2;
866						$thisfile_mpeg_audio_lame_raw['not_optimal_quality'] = ($MiscByte & 0x20) >> 5;
867						$thisfile_mpeg_audio_lame_raw['source_sample_freq']  = ($MiscByte & 0xC0) >> 6;
868						$thisfile_mpeg_audio_lame['noise_shaping']       = $thisfile_mpeg_audio_lame_raw['noise_shaping'];
869						$thisfile_mpeg_audio_lame['stereo_mode']         = self::LAMEmiscStereoModeLookup($thisfile_mpeg_audio_lame_raw['stereo_mode']);
870						$thisfile_mpeg_audio_lame['not_optimal_quality'] = (bool) $thisfile_mpeg_audio_lame_raw['not_optimal_quality'];
871						$thisfile_mpeg_audio_lame['source_sample_freq']  = self::LAMEmiscSourceSampleFrequencyLookup($thisfile_mpeg_audio_lame_raw['source_sample_freq']);
872
873						// byte $B5  MP3 Gain
874						$thisfile_mpeg_audio_lame_raw['mp3_gain'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB5, 1), false, true);
875						$thisfile_mpeg_audio_lame['mp3_gain_db']     = (getid3_lib::RGADamplitude2dB(2) / 4) * $thisfile_mpeg_audio_lame_raw['mp3_gain'];
876						$thisfile_mpeg_audio_lame['mp3_gain_factor'] = pow(2, ($thisfile_mpeg_audio_lame['mp3_gain_db'] / 6));
877
878						// bytes $B6-$B7  Preset and surround info
879						$PresetSurroundBytes = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB6, 2));
880						// Reserved                                                    = ($PresetSurroundBytes & 0xC000);
881						$thisfile_mpeg_audio_lame_raw['surround_info'] = ($PresetSurroundBytes & 0x3800);
882						$thisfile_mpeg_audio_lame['surround_info']     = self::LAMEsurroundInfoLookup($thisfile_mpeg_audio_lame_raw['surround_info']);
883						$thisfile_mpeg_audio_lame['preset_used_id']    = ($PresetSurroundBytes & 0x07FF);
884						$thisfile_mpeg_audio_lame['preset_used']       = self::LAMEpresetUsedLookup($thisfile_mpeg_audio_lame);
885						if (!empty($thisfile_mpeg_audio_lame['preset_used_id']) && empty($thisfile_mpeg_audio_lame['preset_used'])) {
886							$this->warning('Unknown LAME preset used ('.$thisfile_mpeg_audio_lame['preset_used_id'].') - please report to info@getid3.org');
887						}
888						if (($thisfile_mpeg_audio_lame['short_version'] == 'LAME3.90.') && !empty($thisfile_mpeg_audio_lame['preset_used_id'])) {
889							// this may change if 3.90.4 ever comes out
890							$thisfile_mpeg_audio_lame['short_version'] = 'LAME3.90.3';
891						}
892
893						// bytes $B8-$BB  MusicLength
894						$thisfile_mpeg_audio_lame['audio_bytes'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB8, 4));
895						$ExpectedNumberOfAudioBytes = (($thisfile_mpeg_audio_lame['audio_bytes'] > 0) ? $thisfile_mpeg_audio_lame['audio_bytes'] : $thisfile_mpeg_audio['VBR_bytes']);
896
897						// bytes $BC-$BD  MusicCRC
898						$thisfile_mpeg_audio_lame['music_crc']    = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBC, 2));
899
900						// bytes $BE-$BF  CRC-16 of Info Tag
901						$thisfile_mpeg_audio_lame['lame_tag_crc'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBE, 2));
902
903
904						// LAME CBR
905						if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1) {
906
907							$thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
908							$thisfile_mpeg_audio['bitrate'] = self::ClosestStandardMP3Bitrate($thisfile_mpeg_audio['bitrate']);
909							$info['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];
910							//if (empty($thisfile_mpeg_audio['bitrate']) || (!empty($thisfile_mpeg_audio_lame['bitrate_min']) && ($thisfile_mpeg_audio_lame['bitrate_min'] != 255))) {
911							//	$thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio_lame['bitrate_min'];
912							//}
913
914						}
915
916					}
917				}
918
919			} else {
920
921				// not Fraunhofer or Xing VBR methods, most likely CBR (but could be VBR with no header)
922				$thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
923				if ($recursivesearch) {
924					$thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
925					if ($this->RecursiveFrameScanning($offset, $nextframetestoffset, true)) {
926						$recursivesearch = false;
927						$thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
928					}
929					if ($thisfile_mpeg_audio['bitrate_mode'] == 'vbr') {
930						$this->warning('VBR file with no VBR header. Bitrate values calculated from actual frame bitrates.');
931					}
932				}
933
934			}
935
936		}
937
938		if (($ExpectedNumberOfAudioBytes > 0) && ($ExpectedNumberOfAudioBytes != ($info['avdataend'] - $info['avdataoffset']))) {
939			if ($ExpectedNumberOfAudioBytes > ($info['avdataend'] - $info['avdataoffset'])) {
940				if ($this->isDependencyFor('matroska') || $this->isDependencyFor('riff')) {
941					// ignore, audio data is broken into chunks so will always be data "missing"
942				}
943				elseif (($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])) == 1) {
944					$this->warning('Last byte of data truncated (this is a known bug in Meracl ID3 Tag Writer before v1.3.5)');
945				}
946				else {
947					$this->warning('Probable truncated file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, only found '.($info['avdataend'] - $info['avdataoffset']).' (short by '.($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])).' bytes)');
948				}
949			} else {
950				if ((($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes) == 1) {
951				//	$prenullbytefileoffset = $this->ftell();
952				//	$this->fseek($info['avdataend']);
953				//	$PossibleNullByte = $this->fread(1);
954				//	$this->fseek($prenullbytefileoffset);
955				//	if ($PossibleNullByte === "\x00") {
956						$info['avdataend']--;
957				//		$this->warning('Extra null byte at end of MP3 data assumed to be RIFF padding and therefore ignored');
958				//	} else {
959				//		$this->warning('Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']).' ('.(($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)');
960				//	}
961				} else {
962					$this->warning('Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']).' ('.(($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)');
963				}
964			}
965		}
966
967		if (($thisfile_mpeg_audio['bitrate'] == 'free') && empty($info['audio']['bitrate'])) {
968			if (($offset == $info['avdataoffset']) && empty($thisfile_mpeg_audio['VBR_frames'])) {
969				$framebytelength = $this->FreeFormatFrameLength($offset, true);
970				if ($framebytelength > 0) {
971					$thisfile_mpeg_audio['framelength'] = $framebytelength;
972					if ($thisfile_mpeg_audio['layer'] == '1') {
973						// BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
974						$info['audio']['bitrate'] = ((($framebytelength / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
975					} else {
976						// Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
977						$info['audio']['bitrate'] = (($framebytelength - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
978					}
979				} else {
980					$this->error('Error calculating frame length of free-format MP3 without Xing/LAME header');
981				}
982			}
983		}
984
985		if (isset($thisfile_mpeg_audio['VBR_frames']) ? $thisfile_mpeg_audio['VBR_frames'] : '') {
986			switch ($thisfile_mpeg_audio['bitrate_mode']) {
987				case 'vbr':
988				case 'abr':
989					$bytes_per_frame = 1152;
990					if (($thisfile_mpeg_audio['version'] == '1') && ($thisfile_mpeg_audio['layer'] == 1)) {
991						$bytes_per_frame = 384;
992					} elseif ((($thisfile_mpeg_audio['version'] == '2') || ($thisfile_mpeg_audio['version'] == '2.5')) && ($thisfile_mpeg_audio['layer'] == 3)) {
993						$bytes_per_frame = 576;
994					}
995					$thisfile_mpeg_audio['VBR_bitrate'] = (isset($thisfile_mpeg_audio['VBR_bytes']) ? (($thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames']) * 8) * ($info['audio']['sample_rate'] / $bytes_per_frame) : 0);
996					if ($thisfile_mpeg_audio['VBR_bitrate'] > 0) {
997						$info['audio']['bitrate']       = $thisfile_mpeg_audio['VBR_bitrate'];
998						$thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio['VBR_bitrate']; // to avoid confusion
999					}
1000					break;
1001			}
1002		}
1003
1004		// End variable-bitrate headers
1005		////////////////////////////////////////////////////////////////////////////////////
1006
1007		if ($recursivesearch) {
1008
1009			if (!$this->RecursiveFrameScanning($offset, $nextframetestoffset, $ScanAsCBR)) {
1010				return false;
1011			}
1012
1013		}
1014
1015
1016		//if (false) {
1017		//    // experimental side info parsing section - not returning anything useful yet
1018		//
1019		//    $SideInfoBitstream = getid3_lib::BigEndian2Bin($SideInfoData);
1020		//    $SideInfoOffset = 0;
1021		//
1022		//    if ($thisfile_mpeg_audio['version'] == '1') {
1023		//        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
1024		//            // MPEG-1 (mono)
1025		//            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1026		//            $SideInfoOffset += 9;
1027		//            $SideInfoOffset += 5;
1028		//        } else {
1029		//            // MPEG-1 (stereo, joint-stereo, dual-channel)
1030		//            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1031		//            $SideInfoOffset += 9;
1032		//            $SideInfoOffset += 3;
1033		//        }
1034		//    } else { // 2 or 2.5
1035		//        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
1036		//            // MPEG-2, MPEG-2.5 (mono)
1037		//            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
1038		//            $SideInfoOffset += 8;
1039		//            $SideInfoOffset += 1;
1040		//        } else {
1041		//            // MPEG-2, MPEG-2.5 (stereo, joint-stereo, dual-channel)
1042		//            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
1043		//            $SideInfoOffset += 8;
1044		//            $SideInfoOffset += 2;
1045		//        }
1046		//    }
1047		//
1048		//    if ($thisfile_mpeg_audio['version'] == '1') {
1049		//        for ($channel = 0; $channel < $info['audio']['channels']; $channel++) {
1050		//            for ($scfsi_band = 0; $scfsi_band < 4; $scfsi_band++) {
1051		//                $thisfile_mpeg_audio['scfsi'][$channel][$scfsi_band] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1052		//                $SideInfoOffset += 2;
1053		//            }
1054		//        }
1055		//    }
1056		//    for ($granule = 0; $granule < (($thisfile_mpeg_audio['version'] == '1') ? 2 : 1); $granule++) {
1057		//        for ($channel = 0; $channel < $info['audio']['channels']; $channel++) {
1058		//            $thisfile_mpeg_audio['part2_3_length'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 12);
1059		//            $SideInfoOffset += 12;
1060		//            $thisfile_mpeg_audio['big_values'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1061		//            $SideInfoOffset += 9;
1062		//            $thisfile_mpeg_audio['global_gain'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 8);
1063		//            $SideInfoOffset += 8;
1064		//            if ($thisfile_mpeg_audio['version'] == '1') {
1065		//                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
1066		//                $SideInfoOffset += 4;
1067		//            } else {
1068		//                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1069		//                $SideInfoOffset += 9;
1070		//            }
1071		//            $thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1072		//            $SideInfoOffset += 1;
1073		//
1074		//            if ($thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] == '1') {
1075		//
1076		//                $thisfile_mpeg_audio['block_type'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 2);
1077		//                $SideInfoOffset += 2;
1078		//                $thisfile_mpeg_audio['mixed_block_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1079		//                $SideInfoOffset += 1;
1080		//
1081		//                for ($region = 0; $region < 2; $region++) {
1082		//                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
1083		//                    $SideInfoOffset += 5;
1084		//                }
1085		//                $thisfile_mpeg_audio['table_select'][$granule][$channel][2] = 0;
1086		//
1087		//                for ($window = 0; $window < 3; $window++) {
1088		//                    $thisfile_mpeg_audio['subblock_gain'][$granule][$channel][$window] = substr($SideInfoBitstream, $SideInfoOffset, 3);
1089		//                    $SideInfoOffset += 3;
1090		//                }
1091		//
1092		//            } else {
1093		//
1094		//                for ($region = 0; $region < 3; $region++) {
1095		//                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
1096		//                    $SideInfoOffset += 5;
1097		//                }
1098		//
1099		//                $thisfile_mpeg_audio['region0_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
1100		//                $SideInfoOffset += 4;
1101		//                $thisfile_mpeg_audio['region1_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 3);
1102		//                $SideInfoOffset += 3;
1103		//                $thisfile_mpeg_audio['block_type'][$granule][$channel] = 0;
1104		//            }
1105		//
1106		//            if ($thisfile_mpeg_audio['version'] == '1') {
1107		//                $thisfile_mpeg_audio['preflag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1108		//                $SideInfoOffset += 1;
1109		//            }
1110		//            $thisfile_mpeg_audio['scalefac_scale'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1111		//            $SideInfoOffset += 1;
1112		//            $thisfile_mpeg_audio['count1table_select'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1113		//            $SideInfoOffset += 1;
1114		//        }
1115		//    }
1116		//}
1117
1118		return true;
1119	}
1120
1121	/**
1122	 * @param int $offset
1123	 * @param int $nextframetestoffset
1124	 * @param bool $ScanAsCBR
1125	 *
1126	 * @return bool
1127	 */
1128	public function RecursiveFrameScanning(&$offset, &$nextframetestoffset, $ScanAsCBR) {
1129		$info = &$this->getid3->info;
1130		$firstframetestarray = array('error' => array(), 'warning'=> array(), 'avdataend' => $info['avdataend'], 'avdataoffset' => $info['avdataoffset']);
1131		$this->decodeMPEGaudioHeader($offset, $firstframetestarray, false);
1132
1133		for ($i = 0; $i < GETID3_MP3_VALID_CHECK_FRAMES; $i++) {
1134			// check next GETID3_MP3_VALID_CHECK_FRAMES frames for validity, to make sure we haven't run across a false synch
1135			if (($nextframetestoffset + 4) >= $info['avdataend']) {
1136				// end of file
1137				return true;
1138			}
1139
1140			$nextframetestarray = array('error' => array(), 'warning' => array(), 'avdataend' => $info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1141			if ($this->decodeMPEGaudioHeader($nextframetestoffset, $nextframetestarray, false)) {
1142				if ($ScanAsCBR) {
1143					// force CBR mode, used for trying to pick out invalid audio streams with valid(?) VBR headers, or VBR streams with no VBR header
1144					if (!isset($nextframetestarray['mpeg']['audio']['bitrate']) || !isset($firstframetestarray['mpeg']['audio']['bitrate']) || ($nextframetestarray['mpeg']['audio']['bitrate'] != $firstframetestarray['mpeg']['audio']['bitrate'])) {
1145						return false;
1146					}
1147				}
1148
1149
1150				// next frame is OK, get ready to check the one after that
1151				if (isset($nextframetestarray['mpeg']['audio']['framelength']) && ($nextframetestarray['mpeg']['audio']['framelength'] > 0)) {
1152					$nextframetestoffset += $nextframetestarray['mpeg']['audio']['framelength'];
1153				} else {
1154					$this->error('Frame at offset ('.$offset.') is has an invalid frame length.');
1155					return false;
1156				}
1157
1158			} elseif (!empty($firstframetestarray['mpeg']['audio']['framelength']) && (($nextframetestoffset + $firstframetestarray['mpeg']['audio']['framelength']) > $info['avdataend'])) {
1159
1160				// 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
1161				return true;
1162
1163			} else {
1164
1165				// next frame is not valid, note the error and fail, so scanning can contiue for a valid frame sequence
1166				$this->warning('Frame at offset ('.$offset.') is valid, but the next one at ('.$nextframetestoffset.') is not.');
1167
1168				return false;
1169			}
1170		}
1171		return true;
1172	}
1173
1174	/**
1175	 * @param int  $offset
1176	 * @param bool $deepscan
1177	 *
1178	 * @return int|false
1179	 */
1180	public function FreeFormatFrameLength($offset, $deepscan=false) {
1181		$info = &$this->getid3->info;
1182
1183		$this->fseek($offset);
1184		$MPEGaudioData = $this->fread(32768);
1185
1186		$SyncPattern1 = substr($MPEGaudioData, 0, 4);
1187		// may be different pattern due to padding
1188		$SyncPattern2 = $SyncPattern1[0].$SyncPattern1[1].chr(ord($SyncPattern1[2]) | 0x02).$SyncPattern1[3];
1189		if ($SyncPattern2 === $SyncPattern1) {
1190			$SyncPattern2 = $SyncPattern1[0].$SyncPattern1[1].chr(ord($SyncPattern1[2]) & 0xFD).$SyncPattern1[3];
1191		}
1192
1193		$framelength = false;
1194		$framelength1 = strpos($MPEGaudioData, $SyncPattern1, 4);
1195		$framelength2 = strpos($MPEGaudioData, $SyncPattern2, 4);
1196		if ($framelength1 > 4) {
1197			$framelength = $framelength1;
1198		}
1199		if (($framelength2 > 4) && ($framelength2 < $framelength1)) {
1200			$framelength = $framelength2;
1201		}
1202		if (!$framelength) {
1203
1204			// LAME 3.88 has a different value for modeextension on the first frame vs the rest
1205			$framelength1 = strpos($MPEGaudioData, substr($SyncPattern1, 0, 3), 4);
1206			$framelength2 = strpos($MPEGaudioData, substr($SyncPattern2, 0, 3), 4);
1207
1208			if ($framelength1 > 4) {
1209				$framelength = $framelength1;
1210			}
1211			if (($framelength2 > 4) && ($framelength2 < $framelength1)) {
1212				$framelength = $framelength2;
1213			}
1214			if (!$framelength) {
1215				$this->error('Cannot find next free-format synch pattern ('.getid3_lib::PrintHexBytes($SyncPattern1).' or '.getid3_lib::PrintHexBytes($SyncPattern2).') after offset '.$offset);
1216				return false;
1217			} else {
1218				$this->warning('ModeExtension varies between first frame and other frames (known free-format issue in LAME 3.88)');
1219				$info['audio']['codec']   = 'LAME';
1220				$info['audio']['encoder'] = 'LAME3.88';
1221				$SyncPattern1 = substr($SyncPattern1, 0, 3);
1222				$SyncPattern2 = substr($SyncPattern2, 0, 3);
1223			}
1224		}
1225
1226		if ($deepscan) {
1227
1228			$ActualFrameLengthValues = array();
1229			$nextoffset = $offset + $framelength;
1230			while ($nextoffset < ($info['avdataend'] - 6)) {
1231				$this->fseek($nextoffset - 1);
1232				$NextSyncPattern = $this->fread(6);
1233				if ((substr($NextSyncPattern, 1, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 1, strlen($SyncPattern2)) == $SyncPattern2)) {
1234					// good - found where expected
1235					$ActualFrameLengthValues[] = $framelength;
1236				} elseif ((substr($NextSyncPattern, 0, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 0, strlen($SyncPattern2)) == $SyncPattern2)) {
1237					// ok - found one byte earlier than expected (last frame wasn't padded, first frame was)
1238					$ActualFrameLengthValues[] = ($framelength - 1);
1239					$nextoffset--;
1240				} elseif ((substr($NextSyncPattern, 2, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 2, strlen($SyncPattern2)) == $SyncPattern2)) {
1241					// ok - found one byte later than expected (last frame was padded, first frame wasn't)
1242					$ActualFrameLengthValues[] = ($framelength + 1);
1243					$nextoffset++;
1244				} else {
1245					$this->error('Did not find expected free-format sync pattern at offset '.$nextoffset);
1246					return false;
1247				}
1248				$nextoffset += $framelength;
1249			}
1250			if (count($ActualFrameLengthValues) > 0) {
1251				$framelength = intval(round(array_sum($ActualFrameLengthValues) / count($ActualFrameLengthValues)));
1252			}
1253		}
1254		return $framelength;
1255	}
1256
1257	/**
1258	 * @return bool
1259	 */
1260	public function getOnlyMPEGaudioInfoBruteForce() {
1261		$MPEGaudioHeaderDecodeCache   = array();
1262		$MPEGaudioHeaderValidCache    = array();
1263		$MPEGaudioHeaderLengthCache   = array();
1264		$MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();
1265		$MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();
1266		$MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();
1267		$MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();
1268		$MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();
1269		$MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
1270		$MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();
1271		$LongMPEGversionLookup        = array();
1272		$LongMPEGlayerLookup          = array();
1273		$LongMPEGbitrateLookup        = array();
1274		$LongMPEGpaddingLookup        = array();
1275		$LongMPEGfrequencyLookup      = array();
1276		$Distribution['bitrate']      = array();
1277		$Distribution['frequency']    = array();
1278		$Distribution['layer']        = array();
1279		$Distribution['version']      = array();
1280		$Distribution['padding']      = array();
1281
1282		$info = &$this->getid3->info;
1283		$this->fseek($info['avdataoffset']);
1284
1285		$max_frames_scan = 5000;
1286		$frames_scanned  = 0;
1287
1288		$previousvalidframe = $info['avdataoffset'];
1289		while ($this->ftell() < $info['avdataend']) {
1290			set_time_limit(30);
1291			$head4 = $this->fread(4);
1292			if (strlen($head4) < 4) {
1293				break;
1294			}
1295			if ($head4[0] != "\xFF") {
1296				for ($i = 1; $i < 4; $i++) {
1297					if ($head4[$i] == "\xFF") {
1298						$this->fseek($i - 4, SEEK_CUR);
1299						continue 2;
1300					}
1301				}
1302				continue;
1303			}
1304			if (!isset($MPEGaudioHeaderDecodeCache[$head4])) {
1305				$MPEGaudioHeaderDecodeCache[$head4] = self::MPEGaudioHeaderDecode($head4);
1306			}
1307			if (!isset($MPEGaudioHeaderValidCache[$head4])) {
1308				$MPEGaudioHeaderValidCache[$head4] = self::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$head4], false, false);
1309			}
1310			if ($MPEGaudioHeaderValidCache[$head4]) {
1311
1312				if (!isset($MPEGaudioHeaderLengthCache[$head4])) {
1313					$LongMPEGversionLookup[$head4]   = $MPEGaudioVersionLookup[$MPEGaudioHeaderDecodeCache[$head4]['version']];
1314					$LongMPEGlayerLookup[$head4]     = $MPEGaudioLayerLookup[$MPEGaudioHeaderDecodeCache[$head4]['layer']];
1315					$LongMPEGbitrateLookup[$head4]   = $MPEGaudioBitrateLookup[$LongMPEGversionLookup[$head4]][$LongMPEGlayerLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['bitrate']];
1316					$LongMPEGpaddingLookup[$head4]   = (bool) $MPEGaudioHeaderDecodeCache[$head4]['padding'];
1317					$LongMPEGfrequencyLookup[$head4] = $MPEGaudioFrequencyLookup[$LongMPEGversionLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['sample_rate']];
1318					$MPEGaudioHeaderLengthCache[$head4] = self::MPEGaudioFrameLength(
1319						$LongMPEGbitrateLookup[$head4],
1320						$LongMPEGversionLookup[$head4],
1321						$LongMPEGlayerLookup[$head4],
1322						$LongMPEGpaddingLookup[$head4],
1323						$LongMPEGfrequencyLookup[$head4]);
1324				}
1325				if ($MPEGaudioHeaderLengthCache[$head4] > 4) {
1326					$WhereWeWere = $this->ftell();
1327					$this->fseek($MPEGaudioHeaderLengthCache[$head4] - 4, SEEK_CUR);
1328					$next4 = $this->fread(4);
1329					if ($next4[0] == "\xFF") {
1330						if (!isset($MPEGaudioHeaderDecodeCache[$next4])) {
1331							$MPEGaudioHeaderDecodeCache[$next4] = self::MPEGaudioHeaderDecode($next4);
1332						}
1333						if (!isset($MPEGaudioHeaderValidCache[$next4])) {
1334							$MPEGaudioHeaderValidCache[$next4] = self::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$next4], false, false);
1335						}
1336						if ($MPEGaudioHeaderValidCache[$next4]) {
1337							$this->fseek(-4, SEEK_CUR);
1338
1339							$Distribution['bitrate'][$LongMPEGbitrateLookup[$head4]] = isset($Distribution['bitrate'][$LongMPEGbitrateLookup[$head4]]) ? ++$Distribution['bitrate'][$LongMPEGbitrateLookup[$head4]] : 1;
1340							$Distribution['layer'][$LongMPEGlayerLookup[$head4]] = isset($Distribution['layer'][$LongMPEGlayerLookup[$head4]]) ? ++$Distribution['layer'][$LongMPEGlayerLookup[$head4]] : 1;
1341							$Distribution['version'][$LongMPEGversionLookup[$head4]] = isset($Distribution['version'][$LongMPEGversionLookup[$head4]]) ? ++$Distribution['version'][$LongMPEGversionLookup[$head4]] : 1;
1342							$Distribution['padding'][intval($LongMPEGpaddingLookup[$head4])] = isset($Distribution['padding'][intval($LongMPEGpaddingLookup[$head4])]) ? ++$Distribution['padding'][intval($LongMPEGpaddingLookup[$head4])] : 1;
1343							$Distribution['frequency'][$LongMPEGfrequencyLookup[$head4]] = isset($Distribution['frequency'][$LongMPEGfrequencyLookup[$head4]]) ? ++$Distribution['frequency'][$LongMPEGfrequencyLookup[$head4]] : 1;
1344							if (++$frames_scanned >= $max_frames_scan) {
1345								$pct_data_scanned = ($this->ftell() - $info['avdataoffset']) / ($info['avdataend'] - $info['avdataoffset']);
1346								$this->warning('too many MPEG audio frames to scan, only scanned first '.$max_frames_scan.' frames ('.number_format($pct_data_scanned * 100, 1).'% of file) and extrapolated distribution, playtime and bitrate may be incorrect.');
1347								foreach ($Distribution as $key1 => $value1) {
1348									foreach ($value1 as $key2 => $value2) {
1349										$Distribution[$key1][$key2] = round($value2 / $pct_data_scanned);
1350									}
1351								}
1352								break;
1353							}
1354							continue;
1355						}
1356					}
1357					unset($next4);
1358					$this->fseek($WhereWeWere - 3);
1359				}
1360
1361			}
1362		}
1363		foreach ($Distribution as $key => $value) {
1364			ksort($Distribution[$key], SORT_NUMERIC);
1365		}
1366		ksort($Distribution['version'], SORT_STRING);
1367		$info['mpeg']['audio']['bitrate_distribution']   = $Distribution['bitrate'];
1368		$info['mpeg']['audio']['frequency_distribution'] = $Distribution['frequency'];
1369		$info['mpeg']['audio']['layer_distribution']     = $Distribution['layer'];
1370		$info['mpeg']['audio']['version_distribution']   = $Distribution['version'];
1371		$info['mpeg']['audio']['padding_distribution']   = $Distribution['padding'];
1372		if (count($Distribution['version']) > 1) {
1373			$this->error('Corrupt file - more than one MPEG version detected');
1374		}
1375		if (count($Distribution['layer']) > 1) {
1376			$this->error('Corrupt file - more than one MPEG layer detected');
1377		}
1378		if (count($Distribution['frequency']) > 1) {
1379			$this->error('Corrupt file - more than one MPEG sample rate detected');
1380		}
1381
1382
1383		$bittotal = 0;
1384		foreach ($Distribution['bitrate'] as $bitratevalue => $bitratecount) {
1385			if ($bitratevalue != 'free') {
1386				$bittotal += ($bitratevalue * $bitratecount);
1387			}
1388		}
1389		$info['mpeg']['audio']['frame_count']  = array_sum($Distribution['bitrate']);
1390		if ($info['mpeg']['audio']['frame_count'] == 0) {
1391			$this->error('no MPEG audio frames found');
1392			return false;
1393		}
1394		$info['mpeg']['audio']['bitrate']      = ($bittotal / $info['mpeg']['audio']['frame_count']);
1395		$info['mpeg']['audio']['bitrate_mode'] = ((count($Distribution['bitrate']) > 0) ? 'vbr' : 'cbr');
1396		$info['mpeg']['audio']['sample_rate']  = getid3_lib::array_max($Distribution['frequency'], true);
1397
1398		$info['audio']['bitrate']      = $info['mpeg']['audio']['bitrate'];
1399		$info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
1400		$info['audio']['sample_rate']  = $info['mpeg']['audio']['sample_rate'];
1401		$info['audio']['dataformat']   = 'mp'.getid3_lib::array_max($Distribution['layer'], true);
1402		$info['fileformat']            = $info['audio']['dataformat'];
1403
1404		return true;
1405	}
1406
1407	/**
1408	 * @param int  $avdataoffset
1409	 * @param bool $BitrateHistogram
1410	 *
1411	 * @return bool
1412	 */
1413	public function getOnlyMPEGaudioInfo($avdataoffset, $BitrateHistogram=false) {
1414		// looks for synch, decodes MPEG audio header
1415
1416		$info = &$this->getid3->info;
1417
1418		static $MPEGaudioVersionLookup;
1419		static $MPEGaudioLayerLookup;
1420		static $MPEGaudioBitrateLookup;
1421		if (empty($MPEGaudioVersionLookup)) {
1422			$MPEGaudioVersionLookup = self::MPEGaudioVersionArray();
1423			$MPEGaudioLayerLookup   = self::MPEGaudioLayerArray();
1424			$MPEGaudioBitrateLookup = self::MPEGaudioBitrateArray();
1425		}
1426
1427		$this->fseek($avdataoffset);
1428		$sync_seek_buffer_size = min(128 * 1024, $info['avdataend'] - $avdataoffset);
1429		if ($sync_seek_buffer_size <= 0) {
1430			$this->error('Invalid $sync_seek_buffer_size at offset '.$avdataoffset);
1431			return false;
1432		}
1433		$header = $this->fread($sync_seek_buffer_size);
1434		$sync_seek_buffer_size = strlen($header);
1435		$SynchSeekOffset = 0;
1436		while ($SynchSeekOffset < $sync_seek_buffer_size) {
1437			if ((($avdataoffset + $SynchSeekOffset)  < $info['avdataend']) && !feof($this->getid3->fp)) {
1438
1439				if ($SynchSeekOffset > $sync_seek_buffer_size) {
1440					// if a synch's not found within the first 128k bytes, then give up
1441					$this->error('Could not find valid MPEG audio synch within the first '.round($sync_seek_buffer_size / 1024).'kB');
1442					if (isset($info['audio']['bitrate'])) {
1443						unset($info['audio']['bitrate']);
1444					}
1445					if (isset($info['mpeg']['audio'])) {
1446						unset($info['mpeg']['audio']);
1447					}
1448					if (empty($info['mpeg'])) {
1449						unset($info['mpeg']);
1450					}
1451					return false;
1452
1453				} elseif (feof($this->getid3->fp)) {
1454
1455					$this->error('Could not find valid MPEG audio synch before end of file');
1456					if (isset($info['audio']['bitrate'])) {
1457						unset($info['audio']['bitrate']);
1458					}
1459					if (isset($info['mpeg']['audio'])) {
1460						unset($info['mpeg']['audio']);
1461					}
1462					if (isset($info['mpeg']) && (!is_array($info['mpeg']) || (count($info['mpeg']) == 0))) {
1463						unset($info['mpeg']);
1464					}
1465					return false;
1466				}
1467			}
1468
1469			if (($SynchSeekOffset + 1) >= strlen($header)) {
1470				$this->error('Could not find valid MPEG synch before end of file');
1471				return false;
1472			}
1473
1474			if (($header[$SynchSeekOffset] == "\xFF") && ($header[($SynchSeekOffset + 1)] > "\xE0")) { // synch detected
1475				$FirstFrameAVDataOffset = null;
1476				if (!isset($FirstFrameThisfileInfo) && !isset($info['mpeg']['audio'])) {
1477					$FirstFrameThisfileInfo = $info;
1478					$FirstFrameAVDataOffset = $avdataoffset + $SynchSeekOffset;
1479					if (!$this->decodeMPEGaudioHeader($FirstFrameAVDataOffset, $FirstFrameThisfileInfo, false)) {
1480						// if this is the first valid MPEG-audio frame, save it in case it's a VBR header frame and there's
1481						// garbage between this frame and a valid sequence of MPEG-audio frames, to be restored below
1482						unset($FirstFrameThisfileInfo);
1483					}
1484				}
1485
1486				$dummy = $info; // only overwrite real data if valid header found
1487				if ($this->decodeMPEGaudioHeader($avdataoffset + $SynchSeekOffset, $dummy, true)) {
1488					$info = $dummy;
1489					$info['avdataoffset'] = $avdataoffset + $SynchSeekOffset;
1490					switch (isset($info['fileformat']) ? $info['fileformat'] : '') {
1491						case '':
1492						case 'id3':
1493						case 'ape':
1494						case 'mp3':
1495							$info['fileformat']          = 'mp3';
1496							$info['audio']['dataformat'] = 'mp3';
1497							break;
1498					}
1499					if (isset($FirstFrameThisfileInfo) && isset($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode']) && ($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode'] == 'vbr')) {
1500						if (!(abs($info['audio']['bitrate'] - $FirstFrameThisfileInfo['audio']['bitrate']) <= 1)) {
1501							// If there is garbage data between a valid VBR header frame and a sequence
1502							// of valid MPEG-audio frames the VBR data is no longer discarded.
1503							$info = $FirstFrameThisfileInfo;
1504							$info['avdataoffset']        = $FirstFrameAVDataOffset;
1505							$info['fileformat']          = 'mp3';
1506							$info['audio']['dataformat'] = 'mp3';
1507							$dummy                       = $info;
1508							unset($dummy['mpeg']['audio']);
1509							$GarbageOffsetStart = $FirstFrameAVDataOffset + $FirstFrameThisfileInfo['mpeg']['audio']['framelength'];
1510							$GarbageOffsetEnd   = $avdataoffset + $SynchSeekOffset;
1511							if ($this->decodeMPEGaudioHeader($GarbageOffsetEnd, $dummy, true, true)) {
1512								$info = $dummy;
1513								$info['avdataoffset'] = $GarbageOffsetEnd;
1514								$this->warning('apparently-valid VBR header not used because could not find '.GETID3_MP3_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.'), but did find valid CBR stream starting at '.$GarbageOffsetEnd);
1515							} else {
1516								$this->warning('using data from VBR header even though could not find '.GETID3_MP3_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.')');
1517							}
1518						}
1519					}
1520					if (isset($info['mpeg']['audio']['bitrate_mode']) && ($info['mpeg']['audio']['bitrate_mode'] == 'vbr') && !isset($info['mpeg']['audio']['VBR_method'])) {
1521						// VBR file with no VBR header
1522						$BitrateHistogram = true;
1523					}
1524
1525					if ($BitrateHistogram) {
1526
1527						$info['mpeg']['audio']['stereo_distribution']  = array('stereo'=>0, 'joint stereo'=>0, 'dual channel'=>0, 'mono'=>0);
1528						$info['mpeg']['audio']['version_distribution'] = array('1'=>0, '2'=>0, '2.5'=>0);
1529
1530						if ($info['mpeg']['audio']['version'] == '1') {
1531							if ($info['mpeg']['audio']['layer'] == 3) {
1532								$info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 40000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 320000=>0);
1533							} elseif ($info['mpeg']['audio']['layer'] == 2) {
1534								$info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 320000=>0, 384000=>0);
1535							} elseif ($info['mpeg']['audio']['layer'] == 1) {
1536								$info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 64000=>0, 96000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 288000=>0, 320000=>0, 352000=>0, 384000=>0, 416000=>0, 448000=>0);
1537							}
1538						} elseif ($info['mpeg']['audio']['layer'] == 1) {
1539							$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);
1540						} else {
1541							$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);
1542						}
1543
1544						$dummy = array('error'=>$info['error'], 'warning'=>$info['warning'], 'avdataend'=>$info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1545						$synchstartoffset = $info['avdataoffset'];
1546						$this->fseek($info['avdataoffset']);
1547
1548						// you can play with these numbers:
1549						$max_frames_scan  = 50000;
1550						$max_scan_segments = 10;
1551
1552						// don't play with these numbers:
1553						$FastMode = false;
1554						$SynchErrorsFound = 0;
1555						$frames_scanned   = 0;
1556						$this_scan_segment = 0;
1557						$frames_scan_per_segment = ceil($max_frames_scan / $max_scan_segments);
1558						$pct_data_scanned = 0;
1559						for ($current_segment = 0; $current_segment < $max_scan_segments; $current_segment++) {
1560							$frames_scanned_this_segment = 0;
1561							if ($this->ftell() >= $info['avdataend']) {
1562								break;
1563							}
1564							$scan_start_offset[$current_segment] = max($this->ftell(), $info['avdataoffset'] + round($current_segment * (($info['avdataend'] - $info['avdataoffset']) / $max_scan_segments)));
1565							if ($current_segment > 0) {
1566								$this->fseek($scan_start_offset[$current_segment]);
1567								$buffer_4k = $this->fread(4096);
1568								for ($j = 0; $j < (strlen($buffer_4k) - 4); $j++) {
1569									if (($buffer_4k[$j] == "\xFF") && ($buffer_4k[($j + 1)] > "\xE0")) { // synch detected
1570										if ($this->decodeMPEGaudioHeader($scan_start_offset[$current_segment] + $j, $dummy, false, false, $FastMode)) {
1571											$calculated_next_offset = $scan_start_offset[$current_segment] + $j + $dummy['mpeg']['audio']['framelength'];
1572											if ($this->decodeMPEGaudioHeader($calculated_next_offset, $dummy, false, false, $FastMode)) {
1573												$scan_start_offset[$current_segment] += $j;
1574												break;
1575											}
1576										}
1577									}
1578								}
1579							}
1580							$synchstartoffset = $scan_start_offset[$current_segment];
1581							while (($synchstartoffset < $info['avdataend']) && $this->decodeMPEGaudioHeader($synchstartoffset, $dummy, false, false, $FastMode)) {
1582								$FastMode = true;
1583								$thisframebitrate = $MPEGaudioBitrateLookup[$MPEGaudioVersionLookup[$dummy['mpeg']['audio']['raw']['version']]][$MPEGaudioLayerLookup[$dummy['mpeg']['audio']['raw']['layer']]][$dummy['mpeg']['audio']['raw']['bitrate']];
1584
1585								if (empty($dummy['mpeg']['audio']['framelength'])) {
1586									$SynchErrorsFound++;
1587									$synchstartoffset++;
1588								} else {
1589									getid3_lib::safe_inc($info['mpeg']['audio']['bitrate_distribution'][$thisframebitrate]);
1590									getid3_lib::safe_inc($info['mpeg']['audio']['stereo_distribution'][$dummy['mpeg']['audio']['channelmode']]);
1591									getid3_lib::safe_inc($info['mpeg']['audio']['version_distribution'][$dummy['mpeg']['audio']['version']]);
1592									$synchstartoffset += $dummy['mpeg']['audio']['framelength'];
1593								}
1594								$frames_scanned++;
1595								if ($frames_scan_per_segment && (++$frames_scanned_this_segment >= $frames_scan_per_segment)) {
1596									$this_pct_scanned = ($this->ftell() - $scan_start_offset[$current_segment]) / ($info['avdataend'] - $info['avdataoffset']);
1597									if (($current_segment == 0) && (($this_pct_scanned * $max_scan_segments) >= 1)) {
1598										// file likely contains < $max_frames_scan, just scan as one segment
1599										$max_scan_segments = 1;
1600										$frames_scan_per_segment = $max_frames_scan;
1601									} else {
1602										$pct_data_scanned += $this_pct_scanned;
1603										break;
1604									}
1605								}
1606							}
1607						}
1608						if ($pct_data_scanned > 0) {
1609							$this->warning('too many MPEG audio frames to scan, only scanned '.$frames_scanned.' frames in '.$max_scan_segments.' segments ('.number_format($pct_data_scanned * 100, 1).'% of file) and extrapolated distribution, playtime and bitrate may be incorrect.');
1610							foreach ($info['mpeg']['audio'] as $key1 => $value1) {
1611								if (!preg_match('#_distribution$#i', $key1)) {
1612									continue;
1613								}
1614								foreach ($value1 as $key2 => $value2) {
1615									$info['mpeg']['audio'][$key1][$key2] = round($value2 / $pct_data_scanned);
1616								}
1617							}
1618						}
1619
1620						if ($SynchErrorsFound > 0) {
1621							$this->warning('Found '.$SynchErrorsFound.' synch errors in histogram analysis');
1622							//return false;
1623						}
1624
1625						$bittotal     = 0;
1626						$framecounter = 0;
1627						foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitratevalue => $bitratecount) {
1628							$framecounter += $bitratecount;
1629							if ($bitratevalue != 'free') {
1630								$bittotal += ($bitratevalue * $bitratecount);
1631							}
1632						}
1633						if ($framecounter == 0) {
1634							$this->error('Corrupt MP3 file: framecounter == zero');
1635							return false;
1636						}
1637						$info['mpeg']['audio']['frame_count'] = getid3_lib::CastAsInt($framecounter);
1638						$info['mpeg']['audio']['bitrate']     = ($bittotal / $framecounter);
1639
1640						$info['audio']['bitrate'] = $info['mpeg']['audio']['bitrate'];
1641
1642
1643						// Definitively set VBR vs CBR, even if the Xing/LAME/VBRI header says differently
1644						$distinct_bitrates = 0;
1645						foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitrate_value => $bitrate_count) {
1646							if ($bitrate_count > 0) {
1647								$distinct_bitrates++;
1648							}
1649						}
1650						if ($distinct_bitrates > 1) {
1651							$info['mpeg']['audio']['bitrate_mode'] = 'vbr';
1652						} else {
1653							$info['mpeg']['audio']['bitrate_mode'] = 'cbr';
1654						}
1655						$info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
1656
1657					}
1658
1659					break; // exit while()
1660				}
1661			}
1662
1663			$SynchSeekOffset++;
1664			if (($avdataoffset + $SynchSeekOffset) >= $info['avdataend']) {
1665				// end of file/data
1666
1667				if (empty($info['mpeg']['audio'])) {
1668
1669					$this->error('could not find valid MPEG synch before end of file');
1670					if (isset($info['audio']['bitrate'])) {
1671						unset($info['audio']['bitrate']);
1672					}
1673					if (isset($info['mpeg']['audio'])) {
1674						unset($info['mpeg']['audio']);
1675					}
1676					if (isset($info['mpeg']) && (!is_array($info['mpeg']) || empty($info['mpeg']))) {
1677						unset($info['mpeg']);
1678					}
1679					return false;
1680
1681				}
1682				break;
1683			}
1684
1685		}
1686		$info['audio']['channels']        = $info['mpeg']['audio']['channels'];
1687		$info['audio']['channelmode']     = $info['mpeg']['audio']['channelmode'];
1688		$info['audio']['sample_rate']     = $info['mpeg']['audio']['sample_rate'];
1689		return true;
1690	}
1691
1692	/**
1693	 * @return array
1694	 */
1695	public static function MPEGaudioVersionArray() {
1696		static $MPEGaudioVersion = array('2.5', false, '2', '1');
1697		return $MPEGaudioVersion;
1698	}
1699
1700	/**
1701	 * @return array
1702	 */
1703	public static function MPEGaudioLayerArray() {
1704		static $MPEGaudioLayer = array(false, 3, 2, 1);
1705		return $MPEGaudioLayer;
1706	}
1707
1708	/**
1709	 * @return array
1710	 */
1711	public static function MPEGaudioBitrateArray() {
1712		static $MPEGaudioBitrate;
1713		if (empty($MPEGaudioBitrate)) {
1714			$MPEGaudioBitrate = array (
1715				'1'  =>  array (1 => array('free', 32000, 64000, 96000, 128000, 160000, 192000, 224000, 256000, 288000, 320000, 352000, 384000, 416000, 448000),
1716								2 => array('free', 32000, 48000, 56000,  64000,  80000,  96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000, 384000),
1717								3 => array('free', 32000, 40000, 48000,  56000,  64000,  80000,  96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000)
1718							   ),
1719
1720				'2'  =>  array (1 => array('free', 32000, 48000, 56000,  64000,  80000,  96000, 112000, 128000, 144000, 160000, 176000, 192000, 224000, 256000),
1721								2 => array('free',  8000, 16000, 24000,  32000,  40000,  48000,  56000,  64000,  80000,  96000, 112000, 128000, 144000, 160000),
1722							   )
1723			);
1724			$MPEGaudioBitrate['2'][3] = $MPEGaudioBitrate['2'][2];
1725			$MPEGaudioBitrate['2.5']  = $MPEGaudioBitrate['2'];
1726		}
1727		return $MPEGaudioBitrate;
1728	}
1729
1730	/**
1731	 * @return array
1732	 */
1733	public static function MPEGaudioFrequencyArray() {
1734		static $MPEGaudioFrequency;
1735		if (empty($MPEGaudioFrequency)) {
1736			$MPEGaudioFrequency = array (
1737				'1'   => array(44100, 48000, 32000),
1738				'2'   => array(22050, 24000, 16000),
1739				'2.5' => array(11025, 12000,  8000)
1740			);
1741		}
1742		return $MPEGaudioFrequency;
1743	}
1744
1745	/**
1746	 * @return array
1747	 */
1748	public static function MPEGaudioChannelModeArray() {
1749		static $MPEGaudioChannelMode = array('stereo', 'joint stereo', 'dual channel', 'mono');
1750		return $MPEGaudioChannelMode;
1751	}
1752
1753	/**
1754	 * @return array
1755	 */
1756	public static function MPEGaudioModeExtensionArray() {
1757		static $MPEGaudioModeExtension;
1758		if (empty($MPEGaudioModeExtension)) {
1759			$MPEGaudioModeExtension = array (
1760				1 => array('4-31', '8-31', '12-31', '16-31'),
1761				2 => array('4-31', '8-31', '12-31', '16-31'),
1762				3 => array('', 'IS', 'MS', 'IS+MS')
1763			);
1764		}
1765		return $MPEGaudioModeExtension;
1766	}
1767
1768	/**
1769	 * @return array
1770	 */
1771	public static function MPEGaudioEmphasisArray() {
1772		static $MPEGaudioEmphasis = array('none', '50/15ms', false, 'CCIT J.17');
1773		return $MPEGaudioEmphasis;
1774	}
1775
1776	/**
1777	 * @param string $head4
1778	 * @param bool   $allowBitrate15
1779	 *
1780	 * @return bool
1781	 */
1782	public static function MPEGaudioHeaderBytesValid($head4, $allowBitrate15=false) {
1783		return self::MPEGaudioHeaderValid(self::MPEGaudioHeaderDecode($head4), false, $allowBitrate15);
1784	}
1785
1786	/**
1787	 * @param array $rawarray
1788	 * @param bool  $echoerrors
1789	 * @param bool  $allowBitrate15
1790	 *
1791	 * @return bool
1792	 */
1793	public static function MPEGaudioHeaderValid($rawarray, $echoerrors=false, $allowBitrate15=false) {
1794		if (!isset($rawarray['synch']) || ($rawarray['synch'] & 0x0FFE) != 0x0FFE) {
1795			return false;
1796		}
1797
1798		static $MPEGaudioVersionLookup;
1799		static $MPEGaudioLayerLookup;
1800		static $MPEGaudioBitrateLookup;
1801		static $MPEGaudioFrequencyLookup;
1802		static $MPEGaudioChannelModeLookup;
1803		static $MPEGaudioModeExtensionLookup;
1804		static $MPEGaudioEmphasisLookup;
1805		if (empty($MPEGaudioVersionLookup)) {
1806			$MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();
1807			$MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();
1808			$MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();
1809			$MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();
1810			$MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();
1811			$MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
1812			$MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();
1813		}
1814
1815		if (isset($MPEGaudioVersionLookup[$rawarray['version']])) {
1816			$decodedVersion = $MPEGaudioVersionLookup[$rawarray['version']];
1817		} else {
1818			echo ($echoerrors ? "\n".'invalid Version ('.$rawarray['version'].')' : '');
1819			return false;
1820		}
1821		if (isset($MPEGaudioLayerLookup[$rawarray['layer']])) {
1822			$decodedLayer = $MPEGaudioLayerLookup[$rawarray['layer']];
1823		} else {
1824			echo ($echoerrors ? "\n".'invalid Layer ('.$rawarray['layer'].')' : '');
1825			return false;
1826		}
1827		if (!isset($MPEGaudioBitrateLookup[$decodedVersion][$decodedLayer][$rawarray['bitrate']])) {
1828			echo ($echoerrors ? "\n".'invalid Bitrate ('.$rawarray['bitrate'].')' : '');
1829			if ($rawarray['bitrate'] == 15) {
1830				// known issue in LAME 3.90 - 3.93.1 where free-format has bitrate ID of 15 instead of 0
1831				// let it go through here otherwise file will not be identified
1832				if (!$allowBitrate15) {
1833					return false;
1834				}
1835			} else {
1836				return false;
1837			}
1838		}
1839		if (!isset($MPEGaudioFrequencyLookup[$decodedVersion][$rawarray['sample_rate']])) {
1840			echo ($echoerrors ? "\n".'invalid Frequency ('.$rawarray['sample_rate'].')' : '');
1841			return false;
1842		}
1843		if (!isset($MPEGaudioChannelModeLookup[$rawarray['channelmode']])) {
1844			echo ($echoerrors ? "\n".'invalid ChannelMode ('.$rawarray['channelmode'].')' : '');
1845			return false;
1846		}
1847		if (!isset($MPEGaudioModeExtensionLookup[$decodedLayer][$rawarray['modeextension']])) {
1848			echo ($echoerrors ? "\n".'invalid Mode Extension ('.$rawarray['modeextension'].')' : '');
1849			return false;
1850		}
1851		if (!isset($MPEGaudioEmphasisLookup[$rawarray['emphasis']])) {
1852			echo ($echoerrors ? "\n".'invalid Emphasis ('.$rawarray['emphasis'].')' : '');
1853			return false;
1854		}
1855		// These are just either set or not set, you can't mess that up :)
1856		// $rawarray['protection'];
1857		// $rawarray['padding'];
1858		// $rawarray['private'];
1859		// $rawarray['copyright'];
1860		// $rawarray['original'];
1861
1862		return true;
1863	}
1864
1865	/**
1866	 * @param string $Header4Bytes
1867	 *
1868	 * @return array|false
1869	 */
1870	public static function MPEGaudioHeaderDecode($Header4Bytes) {
1871		// AAAA AAAA  AAAB BCCD  EEEE FFGH  IIJJ KLMM
1872		// A - Frame sync (all bits set)
1873		// B - MPEG Audio version ID
1874		// C - Layer description
1875		// D - Protection bit
1876		// E - Bitrate index
1877		// F - Sampling rate frequency index
1878		// G - Padding bit
1879		// H - Private bit
1880		// I - Channel Mode
1881		// J - Mode extension (Only if Joint stereo)
1882		// K - Copyright
1883		// L - Original
1884		// M - Emphasis
1885
1886		if (strlen($Header4Bytes) != 4) {
1887			return false;
1888		}
1889
1890		$MPEGrawHeader['synch']         = (getid3_lib::BigEndian2Int(substr($Header4Bytes, 0, 2)) & 0xFFE0) >> 4;
1891		$MPEGrawHeader['version']       = (ord($Header4Bytes[1]) & 0x18) >> 3; //    BB
1892		$MPEGrawHeader['layer']         = (ord($Header4Bytes[1]) & 0x06) >> 1; //      CC
1893		$MPEGrawHeader['protection']    = (ord($Header4Bytes[1]) & 0x01);      //        D
1894		$MPEGrawHeader['bitrate']       = (ord($Header4Bytes[2]) & 0xF0) >> 4; // EEEE
1895		$MPEGrawHeader['sample_rate']   = (ord($Header4Bytes[2]) & 0x0C) >> 2; //     FF
1896		$MPEGrawHeader['padding']       = (ord($Header4Bytes[2]) & 0x02) >> 1; //       G
1897		$MPEGrawHeader['private']       = (ord($Header4Bytes[2]) & 0x01);      //        H
1898		$MPEGrawHeader['channelmode']   = (ord($Header4Bytes[3]) & 0xC0) >> 6; // II
1899		$MPEGrawHeader['modeextension'] = (ord($Header4Bytes[3]) & 0x30) >> 4; //   JJ
1900		$MPEGrawHeader['copyright']     = (ord($Header4Bytes[3]) & 0x08) >> 3; //     K
1901		$MPEGrawHeader['original']      = (ord($Header4Bytes[3]) & 0x04) >> 2; //      L
1902		$MPEGrawHeader['emphasis']      = (ord($Header4Bytes[3]) & 0x03);      //       MM
1903
1904		return $MPEGrawHeader;
1905	}
1906
1907	/**
1908	 * @param int|string $bitrate
1909	 * @param string     $version
1910	 * @param string     $layer
1911	 * @param bool       $padding
1912	 * @param int        $samplerate
1913	 *
1914	 * @return int|false
1915	 */
1916	public static function MPEGaudioFrameLength(&$bitrate, &$version, &$layer, $padding, &$samplerate) {
1917		static $AudioFrameLengthCache = array();
1918
1919		if (!isset($AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate])) {
1920			$AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = false;
1921			if ($bitrate != 'free') {
1922
1923				if ($version == '1') {
1924
1925					if ($layer == '1') {
1926
1927						// For Layer I slot is 32 bits long
1928						$FrameLengthCoefficient = 48;
1929						$SlotLength = 4;
1930
1931					} else { // Layer 2 / 3
1932
1933						// for Layer 2 and Layer 3 slot is 8 bits long.
1934						$FrameLengthCoefficient = 144;
1935						$SlotLength = 1;
1936
1937					}
1938
1939				} else { // MPEG-2 / MPEG-2.5
1940
1941					if ($layer == '1') {
1942
1943						// For Layer I slot is 32 bits long
1944						$FrameLengthCoefficient = 24;
1945						$SlotLength = 4;
1946
1947					} elseif ($layer == '2') {
1948
1949						// for Layer 2 and Layer 3 slot is 8 bits long.
1950						$FrameLengthCoefficient = 144;
1951						$SlotLength = 1;
1952
1953					} else { // layer 3
1954
1955						// for Layer 2 and Layer 3 slot is 8 bits long.
1956						$FrameLengthCoefficient = 72;
1957						$SlotLength = 1;
1958
1959					}
1960
1961				}
1962
1963				// FrameLengthInBytes = ((Coefficient * BitRate) / SampleRate) + Padding
1964				if ($samplerate > 0) {
1965					$NewFramelength  = ($FrameLengthCoefficient * $bitrate) / $samplerate;
1966					$NewFramelength  = floor($NewFramelength / $SlotLength) * $SlotLength; // round to next-lower multiple of SlotLength (1 byte for Layer 2/3, 4 bytes for Layer I)
1967					if ($padding) {
1968						$NewFramelength += $SlotLength;
1969					}
1970					$AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = (int) $NewFramelength;
1971				}
1972			}
1973		}
1974		return $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate];
1975	}
1976
1977	/**
1978	 * @param float|int $bit_rate
1979	 *
1980	 * @return int|float|string
1981	 */
1982	public static function ClosestStandardMP3Bitrate($bit_rate) {
1983		static $standard_bit_rates = array (320000, 256000, 224000, 192000, 160000, 128000, 112000, 96000, 80000, 64000, 56000, 48000, 40000, 32000, 24000, 16000, 8000);
1984		static $bit_rate_table = array (0=>'-');
1985		$round_bit_rate = intval(round($bit_rate, -3));
1986		if (!isset($bit_rate_table[$round_bit_rate])) {
1987			if ($round_bit_rate > max($standard_bit_rates)) {
1988				$bit_rate_table[$round_bit_rate] = round($bit_rate, 2 - strlen($bit_rate));
1989			} else {
1990				$bit_rate_table[$round_bit_rate] = max($standard_bit_rates);
1991				foreach ($standard_bit_rates as $standard_bit_rate) {
1992					if ($round_bit_rate >= $standard_bit_rate + (($bit_rate_table[$round_bit_rate] - $standard_bit_rate) / 2)) {
1993						break;
1994					}
1995					$bit_rate_table[$round_bit_rate] = $standard_bit_rate;
1996				}
1997			}
1998		}
1999		return $bit_rate_table[$round_bit_rate];
2000	}
2001
2002	/**
2003	 * @param string $version
2004	 * @param string $channelmode
2005	 *
2006	 * @return int
2007	 */
2008	public static function XingVBRidOffset($version, $channelmode) {
2009		static $XingVBRidOffsetCache = array();
2010		if (empty($XingVBRidOffsetCache)) {
2011			$XingVBRidOffsetCache = array (
2012				'1'   => array ('mono'          => 0x15, // 4 + 17 = 21
2013								'stereo'        => 0x24, // 4 + 32 = 36
2014								'joint stereo'  => 0x24,
2015								'dual channel'  => 0x24
2016							   ),
2017
2018				'2'   => array ('mono'          => 0x0D, // 4 +  9 = 13
2019								'stereo'        => 0x15, // 4 + 17 = 21
2020								'joint stereo'  => 0x15,
2021								'dual channel'  => 0x15
2022							   ),
2023
2024				'2.5' => array ('mono'          => 0x15,
2025								'stereo'        => 0x15,
2026								'joint stereo'  => 0x15,
2027								'dual channel'  => 0x15
2028							   )
2029			);
2030		}
2031		return $XingVBRidOffsetCache[$version][$channelmode];
2032	}
2033
2034	/**
2035	 * @param int $VBRmethodID
2036	 *
2037	 * @return string
2038	 */
2039	public static function LAMEvbrMethodLookup($VBRmethodID) {
2040		static $LAMEvbrMethodLookup = array(
2041			0x00 => 'unknown',
2042			0x01 => 'cbr',
2043			0x02 => 'abr',
2044			0x03 => 'vbr-old / vbr-rh',
2045			0x04 => 'vbr-new / vbr-mtrh',
2046			0x05 => 'vbr-mt',
2047			0x06 => 'vbr (full vbr method 4)',
2048			0x08 => 'cbr (constant bitrate 2 pass)',
2049			0x09 => 'abr (2 pass)',
2050			0x0F => 'reserved'
2051		);
2052		return (isset($LAMEvbrMethodLookup[$VBRmethodID]) ? $LAMEvbrMethodLookup[$VBRmethodID] : '');
2053	}
2054
2055	/**
2056	 * @param int $StereoModeID
2057	 *
2058	 * @return string
2059	 */
2060	public static function LAMEmiscStereoModeLookup($StereoModeID) {
2061		static $LAMEmiscStereoModeLookup = array(
2062			0 => 'mono',
2063			1 => 'stereo',
2064			2 => 'dual mono',
2065			3 => 'joint stereo',
2066			4 => 'forced stereo',
2067			5 => 'auto',
2068			6 => 'intensity stereo',
2069			7 => 'other'
2070		);
2071		return (isset($LAMEmiscStereoModeLookup[$StereoModeID]) ? $LAMEmiscStereoModeLookup[$StereoModeID] : '');
2072	}
2073
2074	/**
2075	 * @param int $SourceSampleFrequencyID
2076	 *
2077	 * @return string
2078	 */
2079	public static function LAMEmiscSourceSampleFrequencyLookup($SourceSampleFrequencyID) {
2080		static $LAMEmiscSourceSampleFrequencyLookup = array(
2081			0 => '<= 32 kHz',
2082			1 => '44.1 kHz',
2083			2 => '48 kHz',
2084			3 => '> 48kHz'
2085		);
2086		return (isset($LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID]) ? $LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID] : '');
2087	}
2088
2089	/**
2090	 * @param int $SurroundInfoID
2091	 *
2092	 * @return string
2093	 */
2094	public static function LAMEsurroundInfoLookup($SurroundInfoID) {
2095		static $LAMEsurroundInfoLookup = array(
2096			0 => 'no surround info',
2097			1 => 'DPL encoding',
2098			2 => 'DPL2 encoding',
2099			3 => 'Ambisonic encoding'
2100		);
2101		return (isset($LAMEsurroundInfoLookup[$SurroundInfoID]) ? $LAMEsurroundInfoLookup[$SurroundInfoID] : 'reserved');
2102	}
2103
2104	/**
2105	 * @param array $LAMEtag
2106	 *
2107	 * @return string
2108	 */
2109	public static function LAMEpresetUsedLookup($LAMEtag) {
2110
2111		if ($LAMEtag['preset_used_id'] == 0) {
2112			// no preset used (LAME >=3.93)
2113			// no preset recorded (LAME <3.93)
2114			return '';
2115		}
2116		$LAMEpresetUsedLookup = array();
2117
2118		/////  THIS PART CANNOT BE STATIC .
2119		for ($i = 8; $i <= 320; $i++) {
2120			switch ($LAMEtag['vbr_method']) {
2121				case 'cbr':
2122					$LAMEpresetUsedLookup[$i] = '--alt-preset '.$LAMEtag['vbr_method'].' '.$i;
2123					break;
2124				case 'abr':
2125				default: // other VBR modes shouldn't be here(?)
2126					$LAMEpresetUsedLookup[$i] = '--alt-preset '.$i;
2127					break;
2128			}
2129		}
2130
2131		// named old-style presets (studio, phone, voice, etc) are handled in GuessEncoderOptions()
2132
2133		// named alt-presets
2134		$LAMEpresetUsedLookup[1000] = '--r3mix';
2135		$LAMEpresetUsedLookup[1001] = '--alt-preset standard';
2136		$LAMEpresetUsedLookup[1002] = '--alt-preset extreme';
2137		$LAMEpresetUsedLookup[1003] = '--alt-preset insane';
2138		$LAMEpresetUsedLookup[1004] = '--alt-preset fast standard';
2139		$LAMEpresetUsedLookup[1005] = '--alt-preset fast extreme';
2140		$LAMEpresetUsedLookup[1006] = '--alt-preset medium';
2141		$LAMEpresetUsedLookup[1007] = '--alt-preset fast medium';
2142
2143		// LAME 3.94 additions/changes
2144		$LAMEpresetUsedLookup[1010] = '--preset portable';                                                           // 3.94a15 Oct 21 2003
2145		$LAMEpresetUsedLookup[1015] = '--preset radio';                                                              // 3.94a15 Oct 21 2003
2146
2147		$LAMEpresetUsedLookup[320]  = '--preset insane';                                                             // 3.94a15 Nov 12 2003
2148		$LAMEpresetUsedLookup[410]  = '-V9';
2149		$LAMEpresetUsedLookup[420]  = '-V8';
2150		$LAMEpresetUsedLookup[440]  = '-V6';
2151		$LAMEpresetUsedLookup[430]  = '--preset radio';                                                              // 3.94a15 Nov 12 2003
2152		$LAMEpresetUsedLookup[450]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'portable';  // 3.94a15 Nov 12 2003
2153		$LAMEpresetUsedLookup[460]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'medium';    // 3.94a15 Nov 12 2003
2154		$LAMEpresetUsedLookup[470]  = '--r3mix';                                                                     // 3.94b1  Dec 18 2003
2155		$LAMEpresetUsedLookup[480]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'standard';  // 3.94a15 Nov 12 2003
2156		$LAMEpresetUsedLookup[490]  = '-V1';
2157		$LAMEpresetUsedLookup[500]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'extreme';   // 3.94a15 Nov 12 2003
2158
2159		return (isset($LAMEpresetUsedLookup[$LAMEtag['preset_used_id']]) ? $LAMEpresetUsedLookup[$LAMEtag['preset_used_id']] : 'new/unknown preset: '.$LAMEtag['preset_used_id'].' - report to info@getid3.org');
2160	}
2161
2162}
2163