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