Wordpress 3.6
[autoinstalls/wordpress.git] / wp-includes / ID3 / module.audio.mp3.php
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
21 define('GETID3_MP3_VALID_CHECK_FRAMES', 35);
22
23
24 class getid3_mp3 extends getid3_handler
25 {
26
27         public $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         public function Analyze() {
30                 $info = &$this->getid3->info;
31
32                 $initialOffset = $info['avdataoffset'];
33
34                 if (!$this->getOnlyMPEGaudioInfo($info['avdataoffset'])) {
35                         if ($this->allow_bruteforce) {
36                                 $info['error'][] = 'Rescanning file in BruteForce mode';
37                                 $this->getOnlyMPEGaudioInfoBruteForce($this->getid3->fp, $info);
38                         }
39                 }
40
41
42                 if (isset($info['mpeg']['audio']['bitrate_mode'])) {
43                         $info['audio']['bitrate_mode'] = strtolower($info['mpeg']['audio']['bitrate_mode']);
44                 }
45
46                 if (((isset($info['id3v2']['headerlength']) && ($info['avdataoffset'] > $info['id3v2']['headerlength'])) || (!isset($info['id3v2']) && ($info['avdataoffset'] > 0) && ($info['avdataoffset'] != $initialOffset)))) {
47
48                         $synchoffsetwarning = 'Unknown data before synch ';
49                         if (isset($info['id3v2']['headerlength'])) {
50                                 $synchoffsetwarning .= '(ID3v2 header ends at '.$info['id3v2']['headerlength'].', then '.($info['avdataoffset'] - $info['id3v2']['headerlength']).' bytes garbage, ';
51                         } elseif ($initialOffset > 0) {
52                                 $synchoffsetwarning .= '(should be at '.$initialOffset.', ';
53                         } else {
54                                 $synchoffsetwarning .= '(should be at beginning of file, ';
55                         }
56                         $synchoffsetwarning .= 'synch detected at '.$info['avdataoffset'].')';
57                         if (isset($info['audio']['bitrate_mode']) && ($info['audio']['bitrate_mode'] == 'cbr')) {
58
59                                 if (!empty($info['id3v2']['headerlength']) && (($info['avdataoffset'] - $info['id3v2']['headerlength']) == $info['mpeg']['audio']['framelength'])) {
60
61                                         $synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90-3.92) DLL in CBR mode.';
62                                         $info['audio']['codec'] = 'LAME';
63                                         $CurrentDataLAMEversionString = 'LAME3.';
64
65                                 } elseif (empty($info['id3v2']['headerlength']) && ($info['avdataoffset'] == $info['mpeg']['audio']['framelength'])) {
66
67                                         $synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90 - 3.92) DLL in CBR mode.';
68                                         $info['audio']['codec'] = 'LAME';
69                                         $CurrentDataLAMEversionString = 'LAME3.';
70
71                                 }
72
73                         }
74                         $info['warning'][] = $synchoffsetwarning;
75
76                 }
77
78                 if (isset($info['mpeg']['audio']['LAME'])) {
79                         $info['audio']['codec'] = 'LAME';
80                         if (!empty($info['mpeg']['audio']['LAME']['long_version'])) {
81                                 $info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['long_version'], "\x00");
82                         } elseif (!empty($info['mpeg']['audio']['LAME']['short_version'])) {
83                                 $info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['short_version'], "\x00");
84                         }
85                 }
86
87                 $CurrentDataLAMEversionString = (!empty($CurrentDataLAMEversionString) ? $CurrentDataLAMEversionString : (isset($info['audio']['encoder']) ? $info['audio']['encoder'] : ''));
88                 if (!empty($CurrentDataLAMEversionString) && (substr($CurrentDataLAMEversionString, 0, 6) == 'LAME3.') && !preg_match('[0-9\)]', substr($CurrentDataLAMEversionString, -1))) {
89                         // a version number of LAME that does not end with a number like "LAME3.92"
90                         // or with a closing parenthesis like "LAME3.88 (alpha)"
91                         // or a version of LAME with the LAMEtag-not-filled-in-DLL-mode bug (3.90-3.92)
92
93                         // not sure what the actual last frame length will be, but will be less than or equal to 1441
94                         $PossiblyLongerLAMEversion_FrameLength = 1441;
95
96                         // Not sure what version of LAME this is - look in padding of last frame for longer version string
97                         $PossibleLAMEversionStringOffset = $info['avdataend'] - $PossiblyLongerLAMEversion_FrameLength;
98                         fseek($this->getid3->fp, $PossibleLAMEversionStringOffset);
99                         $PossiblyLongerLAMEversion_Data = fread($this->getid3->fp, $PossiblyLongerLAMEversion_FrameLength);
100                         switch (substr($CurrentDataLAMEversionString, -1)) {
101                                 case 'a':
102                                 case 'b':
103                                         // "LAME3.94a" will have a longer version string of "LAME3.94 (alpha)" for example
104                                         // need to trim off "a" to match longer string
105                                         $CurrentDataLAMEversionString = substr($CurrentDataLAMEversionString, 0, -1);
106                                         break;
107                         }
108                         if (($PossiblyLongerLAMEversion_String = strstr($PossiblyLongerLAMEversion_Data, $CurrentDataLAMEversionString)) !== false) {
109                                 if (substr($PossiblyLongerLAMEversion_String, 0, strlen($CurrentDataLAMEversionString)) == $CurrentDataLAMEversionString) {
110                                         $PossiblyLongerLAMEversion_NewString = substr($PossiblyLongerLAMEversion_String, 0, strspn($PossiblyLongerLAMEversion_String, 'LAME0123456789., (abcdefghijklmnopqrstuvwxyzJFSOND)')); //"LAME3.90.3"  "LAME3.87 (beta 1, Sep 27 2000)" "LAME3.88 (beta)"
111                                         if (empty($info['audio']['encoder']) || (strlen($PossiblyLongerLAMEversion_NewString) > strlen($info['audio']['encoder']))) {
112                                                 $info['audio']['encoder'] = $PossiblyLongerLAMEversion_NewString;
113                                         }
114                                 }
115                         }
116                 }
117                 if (!empty($info['audio']['encoder'])) {
118                         $info['audio']['encoder'] = rtrim($info['audio']['encoder'], "\x00 ");
119                 }
120
121                 switch (isset($info['mpeg']['audio']['layer']) ? $info['mpeg']['audio']['layer'] : '') {
122                         case 1:
123                         case 2:
124                                 $info['audio']['dataformat'] = 'mp'.$info['mpeg']['audio']['layer'];
125                                 break;
126                 }
127                 if (isset($info['fileformat']) && ($info['fileformat'] == 'mp3')) {
128                         switch ($info['audio']['dataformat']) {
129                                 case 'mp1':
130                                 case 'mp2':
131                                 case 'mp3':
132                                         $info['fileformat'] = $info['audio']['dataformat'];
133                                         break;
134
135                                 default:
136                                         $info['warning'][] = 'Expecting [audio][dataformat] to be mp1/mp2/mp3 when fileformat == mp3, [audio][dataformat] actually "'.$info['audio']['dataformat'].'"';
137                                         break;
138                         }
139                 }
140
141                 if (empty($info['fileformat'])) {
142                         unset($info['fileformat']);
143                         unset($info['audio']['bitrate_mode']);
144                         unset($info['avdataoffset']);
145                         unset($info['avdataend']);
146                         return false;
147                 }
148
149                 $info['mime_type']         = 'audio/mpeg';
150                 $info['audio']['lossless'] = false;
151
152                 // Calculate playtime
153                 if (!isset($info['playtime_seconds']) && isset($info['audio']['bitrate']) && ($info['audio']['bitrate'] > 0)) {
154                         $info['playtime_seconds'] = ($info['avdataend'] - $info['avdataoffset']) * 8 / $info['audio']['bitrate'];
155                 }
156
157                 $info['audio']['encoder_options'] = $this->GuessEncoderOptions();
158
159                 return true;
160         }
161
162
163         public function GuessEncoderOptions() {
164                 // shortcuts
165                 $info = &$this->getid3->info;
166                 if (!empty($info['mpeg']['audio'])) {
167                         $thisfile_mpeg_audio = &$info['mpeg']['audio'];
168                         if (!empty($thisfile_mpeg_audio['LAME'])) {
169                                 $thisfile_mpeg_audio_lame = &$thisfile_mpeg_audio['LAME'];
170                         }
171                 }
172
173                 $encoder_options = '';
174                 static $NamedPresetBitrates = array(16, 24, 40, 56, 112, 128, 160, 192, 256);
175
176                 if (isset($thisfile_mpeg_audio['VBR_method']) && ($thisfile_mpeg_audio['VBR_method'] == 'Fraunhofer') && !empty($thisfile_mpeg_audio['VBR_quality'])) {
177
178                         $encoder_options = 'VBR q'.$thisfile_mpeg_audio['VBR_quality'];
179
180                 } elseif (!empty($thisfile_mpeg_audio_lame['preset_used']) && (!in_array($thisfile_mpeg_audio_lame['preset_used_id'], $NamedPresetBitrates))) {
181
182                         $encoder_options = $thisfile_mpeg_audio_lame['preset_used'];
183
184                 } elseif (!empty($thisfile_mpeg_audio_lame['vbr_quality'])) {
185
186                         static $KnownEncoderValues = array();
187                         if (empty($KnownEncoderValues)) {
188
189                                 //$KnownEncoderValues[abrbitrate_minbitrate][vbr_quality][raw_vbr_method][raw_noise_shaping][raw_stereo_mode][ath_type][lowpass_frequency] = 'preset name';
190                                 $KnownEncoderValues[0xFF][58][1][1][3][2][20500] = '--alt-preset insane';        // 3.90,   3.90.1, 3.92
191                                 $KnownEncoderValues[0xFF][58][1][1][3][2][20600] = '--alt-preset insane';        // 3.90.2, 3.90.3, 3.91
192                                 $KnownEncoderValues[0xFF][57][1][1][3][4][20500] = '--alt-preset insane';        // 3.94,   3.95
193                                 $KnownEncoderValues['**'][78][3][2][3][2][19500] = '--alt-preset extreme';       // 3.90,   3.90.1, 3.92
194                                 $KnownEncoderValues['**'][78][3][2][3][2][19600] = '--alt-preset extreme';       // 3.90.2, 3.91
195                                 $KnownEncoderValues['**'][78][3][1][3][2][19600] = '--alt-preset extreme';       // 3.90.3
196                                 $KnownEncoderValues['**'][78][4][2][3][2][19500] = '--alt-preset fast extreme';  // 3.90,   3.90.1, 3.92
197                                 $KnownEncoderValues['**'][78][4][2][3][2][19600] = '--alt-preset fast extreme';  // 3.90.2, 3.90.3, 3.91
198                                 $KnownEncoderValues['**'][78][3][2][3][4][19000] = '--alt-preset standard';      // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
199                                 $KnownEncoderValues['**'][78][3][1][3][4][19000] = '--alt-preset standard';      // 3.90.3
200                                 $KnownEncoderValues['**'][78][4][2][3][4][19000] = '--alt-preset fast standard'; // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
201                                 $KnownEncoderValues['**'][78][4][1][3][4][19000] = '--alt-preset fast standard'; // 3.90.3
202                                 $KnownEncoderValues['**'][88][4][1][3][3][19500] = '--r3mix';                    // 3.90,   3.90.1, 3.92
203                                 $KnownEncoderValues['**'][88][4][1][3][3][19600] = '--r3mix';                    // 3.90.2, 3.90.3, 3.91
204                                 $KnownEncoderValues['**'][67][4][1][3][4][18000] = '--r3mix';                    // 3.94,   3.95
205                                 $KnownEncoderValues['**'][68][3][2][3][4][18000] = '--alt-preset medium';        // 3.90.3
206                                 $KnownEncoderValues['**'][68][4][2][3][4][18000] = '--alt-preset fast medium';   // 3.90.3
207
208                                 $KnownEncoderValues[0xFF][99][1][1][1][2][0]     = '--preset studio';            // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
209                                 $KnownEncoderValues[0xFF][58][2][1][3][2][20600] = '--preset studio';            // 3.90.3, 3.93.1
210                                 $KnownEncoderValues[0xFF][58][2][1][3][2][20500] = '--preset studio';            // 3.93
211                                 $KnownEncoderValues[0xFF][57][2][1][3][4][20500] = '--preset studio';            // 3.94,   3.95
212                                 $KnownEncoderValues[0xC0][88][1][1][1][2][0]     = '--preset cd';                // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
213                                 $KnownEncoderValues[0xC0][58][2][2][3][2][19600] = '--preset cd';                // 3.90.3, 3.93.1
214                                 $KnownEncoderValues[0xC0][58][2][2][3][2][19500] = '--preset cd';                // 3.93
215                                 $KnownEncoderValues[0xC0][57][2][1][3][4][19500] = '--preset cd';                // 3.94,   3.95
216                                 $KnownEncoderValues[0xA0][78][1][1][3][2][18000] = '--preset hifi';              // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
217                                 $KnownEncoderValues[0xA0][58][2][2][3][2][18000] = '--preset hifi';              // 3.90.3, 3.93,   3.93.1
218                                 $KnownEncoderValues[0xA0][57][2][1][3][4][18000] = '--preset hifi';              // 3.94,   3.95
219                                 $KnownEncoderValues[0x80][67][1][1][3][2][18000] = '--preset tape';              // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
220                                 $KnownEncoderValues[0x80][67][1][1][3][2][15000] = '--preset radio';             // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
221                                 $KnownEncoderValues[0x70][67][1][1][3][2][15000] = '--preset fm';                // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
222                                 $KnownEncoderValues[0x70][58][2][2][3][2][16000] = '--preset tape/radio/fm';     // 3.90.3, 3.93,   3.93.1
223                                 $KnownEncoderValues[0x70][57][2][1][3][4][16000] = '--preset tape/radio/fm';     // 3.94,   3.95
224                                 $KnownEncoderValues[0x38][58][2][2][0][2][10000] = '--preset voice';             // 3.90.3, 3.93,   3.93.1
225                                 $KnownEncoderValues[0x38][57][2][1][0][4][15000] = '--preset voice';             // 3.94,   3.95
226                                 $KnownEncoderValues[0x38][57][2][1][0][4][16000] = '--preset voice';             // 3.94a14
227                                 $KnownEncoderValues[0x28][65][1][1][0][2][7500]  = '--preset mw-us';             // 3.90,   3.90.1, 3.92
228                                 $KnownEncoderValues[0x28][65][1][1][0][2][7600]  = '--preset mw-us';             // 3.90.2, 3.91
229                                 $KnownEncoderValues[0x28][58][2][2][0][2][7000]  = '--preset mw-us';             // 3.90.3, 3.93,   3.93.1
230                                 $KnownEncoderValues[0x28][57][2][1][0][4][10500] = '--preset mw-us';             // 3.94,   3.95
231                                 $KnownEncoderValues[0x28][57][2][1][0][4][11200] = '--preset mw-us';             // 3.94a14
232                                 $KnownEncoderValues[0x28][57][2][1][0][4][8800]  = '--preset mw-us';             // 3.94a15
233                                 $KnownEncoderValues[0x18][58][2][2][0][2][4000]  = '--preset phon+/lw/mw-eu/sw'; // 3.90.3, 3.93.1
234                                 $KnownEncoderValues[0x18][58][2][2][0][2][3900]  = '--preset phon+/lw/mw-eu/sw'; // 3.93
235                                 $KnownEncoderValues[0x18][57][2][1][0][4][5900]  = '--preset phon+/lw/mw-eu/sw'; // 3.94,   3.95
236                                 $KnownEncoderValues[0x18][57][2][1][0][4][6200]  = '--preset phon+/lw/mw-eu/sw'; // 3.94a14
237                                 $KnownEncoderValues[0x18][57][2][1][0][4][3200]  = '--preset phon+/lw/mw-eu/sw'; // 3.94a15
238                                 $KnownEncoderValues[0x10][58][2][2][0][2][3800]  = '--preset phone';             // 3.90.3, 3.93.1
239                                 $KnownEncoderValues[0x10][58][2][2][0][2][3700]  = '--preset phone';             // 3.93
240                                 $KnownEncoderValues[0x10][57][2][1][0][4][5600]  = '--preset phone';             // 3.94,   3.95
241                         }
242
243                         if (isset($KnownEncoderValues[$thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate']][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']])) {
244
245                                 $encoder_options = $KnownEncoderValues[$thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate']][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']];
246
247                         } elseif (isset($KnownEncoderValues['**'][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']])) {
248
249                                 $encoder_options = $KnownEncoderValues['**'][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']];
250
251                         } elseif ($info['audio']['bitrate_mode'] == 'vbr') {
252
253                                 // http://gabriel.mp3-tech.org/mp3infotag.html
254                                 // int    Quality = (100 - 10 * gfp->VBR_q - gfp->quality)h
255
256
257                                 $LAME_V_value = 10 - ceil($thisfile_mpeg_audio_lame['vbr_quality'] / 10);
258                                 $LAME_q_value = 100 - $thisfile_mpeg_audio_lame['vbr_quality'] - ($LAME_V_value * 10);
259                                 $encoder_options = '-V'.$LAME_V_value.' -q'.$LAME_q_value;
260
261                         } elseif ($info['audio']['bitrate_mode'] == 'cbr') {
262
263                                 $encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
264
265                         } else {
266
267                                 $encoder_options = strtoupper($info['audio']['bitrate_mode']);
268
269                         }
270
271                 } elseif (!empty($thisfile_mpeg_audio_lame['bitrate_abr'])) {
272
273                         $encoder_options = 'ABR'.$thisfile_mpeg_audio_lame['bitrate_abr'];
274
275                 } elseif (!empty($info['audio']['bitrate'])) {
276
277                         if ($info['audio']['bitrate_mode'] == 'cbr') {
278                                 $encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
279                         } else {
280                                 $encoder_options = strtoupper($info['audio']['bitrate_mode']);
281                         }
282
283                 }
284                 if (!empty($thisfile_mpeg_audio_lame['bitrate_min'])) {
285                         $encoder_options .= ' -b'.$thisfile_mpeg_audio_lame['bitrate_min'];
286                 }
287
288                 if (!empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev']) || !empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_next'])) {
289                         $encoder_options .= ' --nogap';
290                 }
291
292                 if (!empty($thisfile_mpeg_audio_lame['lowpass_frequency'])) {
293                         $ExplodedOptions = explode(' ', $encoder_options, 4);
294                         if ($ExplodedOptions[0] == '--r3mix') {
295                                 $ExplodedOptions[1] = 'r3mix';
296                         }
297                         switch ($ExplodedOptions[0]) {
298                                 case '--preset':
299                                 case '--alt-preset':
300                                 case '--r3mix':
301                                         if ($ExplodedOptions[1] == 'fast') {
302                                                 $ExplodedOptions[1] .= ' '.$ExplodedOptions[2];
303                                         }
304                                         switch ($ExplodedOptions[1]) {
305                                                 case 'portable':
306                                                 case 'medium':
307                                                 case 'standard':
308                                                 case 'extreme':
309                                                 case 'insane':
310                                                 case 'fast portable':
311                                                 case 'fast medium':
312                                                 case 'fast standard':
313                                                 case 'fast extreme':
314                                                 case 'fast insane':
315                                                 case 'r3mix':
316                                                         static $ExpectedLowpass = array(
317                                                                         'insane|20500'        => 20500,
318                                                                         'insane|20600'        => 20600,  // 3.90.2, 3.90.3, 3.91
319                                                                         'medium|18000'        => 18000,
320                                                                         'fast medium|18000'   => 18000,
321                                                                         'extreme|19500'       => 19500,  // 3.90,   3.90.1, 3.92, 3.95
322                                                                         'extreme|19600'       => 19600,  // 3.90.2, 3.90.3, 3.91, 3.93.1
323                                                                         'fast extreme|19500'  => 19500,  // 3.90,   3.90.1, 3.92, 3.95
324                                                                         'fast extreme|19600'  => 19600,  // 3.90.2, 3.90.3, 3.91, 3.93.1
325                                                                         'standard|19000'      => 19000,
326                                                                         'fast standard|19000' => 19000,
327                                                                         'r3mix|19500'         => 19500,  // 3.90,   3.90.1, 3.92
328                                                                         'r3mix|19600'         => 19600,  // 3.90.2, 3.90.3, 3.91
329                                                                         'r3mix|18000'         => 18000,  // 3.94,   3.95
330                                                                 );
331                                                         if (!isset($ExpectedLowpass[$ExplodedOptions[1].'|'.$thisfile_mpeg_audio_lame['lowpass_frequency']]) && ($thisfile_mpeg_audio_lame['lowpass_frequency'] < 22050) && (round($thisfile_mpeg_audio_lame['lowpass_frequency'] / 1000) < round($thisfile_mpeg_audio['sample_rate'] / 2000))) {
332                                                                 $encoder_options .= ' --lowpass '.$thisfile_mpeg_audio_lame['lowpass_frequency'];
333                                                         }
334                                                         break;
335
336                                                 default:
337                                                         break;
338                                         }
339                                         break;
340                         }
341                 }
342
343                 if (isset($thisfile_mpeg_audio_lame['raw']['source_sample_freq'])) {
344                         if (($thisfile_mpeg_audio['sample_rate'] == 44100) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 1)) {
345                                 $encoder_options .= ' --resample 44100';
346                         } elseif (($thisfile_mpeg_audio['sample_rate'] == 48000) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 2)) {
347                                 $encoder_options .= ' --resample 48000';
348                         } elseif ($thisfile_mpeg_audio['sample_rate'] < 44100) {
349                                 switch ($thisfile_mpeg_audio_lame['raw']['source_sample_freq']) {
350                                         case 0: // <= 32000
351                                                 // may or may not be same as source frequency - ignore
352                                                 break;
353                                         case 1: // 44100
354                                         case 2: // 48000
355                                         case 3: // 48000+
356                                                 $ExplodedOptions = explode(' ', $encoder_options, 4);
357                                                 switch ($ExplodedOptions[0]) {
358                                                         case '--preset':
359                                                         case '--alt-preset':
360                                                                 switch ($ExplodedOptions[1]) {
361                                                                         case 'fast':
362                                                                         case 'portable':
363                                                                         case 'medium':
364                                                                         case 'standard':
365                                                                         case 'extreme':
366                                                                         case 'insane':
367                                                                                 $encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
368                                                                                 break;
369
370                                                                         default:
371                                                                                 static $ExpectedResampledRate = array(
372                                                                                                 'phon+/lw/mw-eu/sw|16000' => 16000,
373                                                                                                 'mw-us|24000'             => 24000, // 3.95
374                                                                                                 'mw-us|32000'             => 32000, // 3.93
375                                                                                                 'mw-us|16000'             => 16000, // 3.92
376                                                                                                 'phone|16000'             => 16000,
377                                                                                                 'phone|11025'             => 11025, // 3.94a15
378                                                                                                 'radio|32000'             => 32000, // 3.94a15
379                                                                                                 'fm/radio|32000'          => 32000, // 3.92
380                                                                                                 'fm|32000'                => 32000, // 3.90
381                                                                                                 'voice|32000'             => 32000);
382                                                                                 if (!isset($ExpectedResampledRate[$ExplodedOptions[1].'|'.$thisfile_mpeg_audio['sample_rate']])) {
383                                                                                         $encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
384                                                                                 }
385                                                                                 break;
386                                                                 }
387                                                                 break;
388
389                                                         case '--r3mix':
390                                                         default:
391                                                                 $encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
392                                                                 break;
393                                                 }
394                                                 break;
395                                 }
396                         }
397                 }
398                 if (empty($encoder_options) && !empty($info['audio']['bitrate']) && !empty($info['audio']['bitrate_mode'])) {
399                         //$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
400                         $encoder_options = strtoupper($info['audio']['bitrate_mode']);
401                 }
402
403                 return $encoder_options;
404         }
405
406
407         public function decodeMPEGaudioHeader($offset, &$info, $recursivesearch=true, $ScanAsCBR=false, $FastMPEGheaderScan=false) {
408                 static $MPEGaudioVersionLookup;
409                 static $MPEGaudioLayerLookup;
410                 static $MPEGaudioBitrateLookup;
411                 static $MPEGaudioFrequencyLookup;
412                 static $MPEGaudioChannelModeLookup;
413                 static $MPEGaudioModeExtensionLookup;
414                 static $MPEGaudioEmphasisLookup;
415                 if (empty($MPEGaudioVersionLookup)) {
416                         $MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();
417                         $MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();
418                         $MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();
419                         $MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();
420                         $MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();
421                         $MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
422                         $MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();
423                 }
424
425                 if (fseek($this->getid3->fp, $offset, SEEK_SET) != 0) {
426                         $info['error'][] = 'decodeMPEGaudioHeader() failed to seek to next offset at '.$offset;
427                         return false;
428                 }
429                 //$headerstring = fread($this->getid3->fp, 1441); // worst-case max length = 32kHz @ 320kbps layer 3 = 1441 bytes/frame
430                 $headerstring = fread($this->getid3->fp, 226); // LAME header at offset 36 + 190 bytes of Xing/LAME data
431
432                 // MP3 audio frame structure:
433                 // $aa $aa $aa $aa [$bb $bb] $cc...
434                 // where $aa..$aa is the four-byte mpeg-audio header (below)
435                 // $bb $bb is the optional 2-byte CRC
436                 // and $cc... is the audio data
437
438                 $head4 = substr($headerstring, 0, 4);
439
440                 static $MPEGaudioHeaderDecodeCache = array();
441                 if (isset($MPEGaudioHeaderDecodeCache[$head4])) {
442                         $MPEGheaderRawArray = $MPEGaudioHeaderDecodeCache[$head4];
443                 } else {
444                         $MPEGheaderRawArray = self::MPEGaudioHeaderDecode($head4);
445                         $MPEGaudioHeaderDecodeCache[$head4] = $MPEGheaderRawArray;
446                 }
447
448                 static $MPEGaudioHeaderValidCache = array();
449                 if (!isset($MPEGaudioHeaderValidCache[$head4])) { // Not in cache
450                         //$MPEGaudioHeaderValidCache[$head4] = self::MPEGaudioHeaderValid($MPEGheaderRawArray, false, true);  // allow badly-formatted freeformat (from LAME 3.90 - 3.93.1)
451                         $MPEGaudioHeaderValidCache[$head4] = self::MPEGaudioHeaderValid($MPEGheaderRawArray, false, false);
452                 }
453
454                 // shortcut
455                 if (!isset($info['mpeg']['audio'])) {
456                         $info['mpeg']['audio'] = array();
457                 }
458                 $thisfile_mpeg_audio = &$info['mpeg']['audio'];
459
460
461                 if ($MPEGaudioHeaderValidCache[$head4]) {
462                         $thisfile_mpeg_audio['raw'] = $MPEGheaderRawArray;
463                 } else {
464                         $info['error'][] = 'Invalid MPEG audio header ('.getid3_lib::PrintHexBytes($head4).') at offset '.$offset;
465                         return false;
466                 }
467
468                 if (!$FastMPEGheaderScan) {
469                         $thisfile_mpeg_audio['version']       = $MPEGaudioVersionLookup[$thisfile_mpeg_audio['raw']['version']];
470                         $thisfile_mpeg_audio['layer']         = $MPEGaudioLayerLookup[$thisfile_mpeg_audio['raw']['layer']];
471
472                         $thisfile_mpeg_audio['channelmode']   = $MPEGaudioChannelModeLookup[$thisfile_mpeg_audio['raw']['channelmode']];
473                         $thisfile_mpeg_audio['channels']      = (($thisfile_mpeg_audio['channelmode'] == 'mono') ? 1 : 2);
474                         $thisfile_mpeg_audio['sample_rate']   = $MPEGaudioFrequencyLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['raw']['sample_rate']];
475                         $thisfile_mpeg_audio['protection']    = !$thisfile_mpeg_audio['raw']['protection'];
476                         $thisfile_mpeg_audio['private']       = (bool) $thisfile_mpeg_audio['raw']['private'];
477                         $thisfile_mpeg_audio['modeextension'] = $MPEGaudioModeExtensionLookup[$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['modeextension']];
478                         $thisfile_mpeg_audio['copyright']     = (bool) $thisfile_mpeg_audio['raw']['copyright'];
479                         $thisfile_mpeg_audio['original']      = (bool) $thisfile_mpeg_audio['raw']['original'];
480                         $thisfile_mpeg_audio['emphasis']      = $MPEGaudioEmphasisLookup[$thisfile_mpeg_audio['raw']['emphasis']];
481
482                         $info['audio']['channels']    = $thisfile_mpeg_audio['channels'];
483                         $info['audio']['sample_rate'] = $thisfile_mpeg_audio['sample_rate'];
484
485                         if ($thisfile_mpeg_audio['protection']) {
486                                 $thisfile_mpeg_audio['crc'] = getid3_lib::BigEndian2Int(substr($headerstring, 4, 2));
487                         }
488                 }
489
490                 if ($thisfile_mpeg_audio['raw']['bitrate'] == 15) {
491                         // http://www.hydrogenaudio.org/?act=ST&f=16&t=9682&st=0
492                         $info['warning'][] = 'Invalid bitrate index (15), this is a known bug in free-format MP3s encoded by LAME v3.90 - 3.93.1';
493                         $thisfile_mpeg_audio['raw']['bitrate'] = 0;
494                 }
495                 $thisfile_mpeg_audio['padding'] = (bool) $thisfile_mpeg_audio['raw']['padding'];
496                 $thisfile_mpeg_audio['bitrate'] = $MPEGaudioBitrateLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['bitrate']];
497
498                 if (($thisfile_mpeg_audio['bitrate'] == 'free') && ($offset == $info['avdataoffset'])) {
499                         // only skip multiple frame check if free-format bitstream found at beginning of file
500                         // otherwise is quite possibly simply corrupted data
501                         $recursivesearch = false;
502                 }
503
504                 // For Layer 2 there are some combinations of bitrate and mode which are not allowed.
505                 if (!$FastMPEGheaderScan && ($thisfile_mpeg_audio['layer'] == '2')) {
506
507                         $info['audio']['dataformat'] = 'mp2';
508                         switch ($thisfile_mpeg_audio['channelmode']) {
509
510                                 case 'mono':
511                                         if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] <= 192000)) {
512                                                 // these are ok
513                                         } else {
514                                                 $info['error'][] = $thisfile_mpeg_audio['bitrate'].'kbps not allowed in Layer 2, '.$thisfile_mpeg_audio['channelmode'].'.';
515                                                 return false;
516                                         }
517                                         break;
518
519                                 case 'stereo':
520                                 case 'joint stereo':
521                                 case 'dual channel':
522                                         if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] == 64000) || ($thisfile_mpeg_audio['bitrate'] >= 96000)) {
523                                                 // these are ok
524                                         } else {
525                                                 $info['error'][] = intval(round($thisfile_mpeg_audio['bitrate'] / 1000)).'kbps not allowed in Layer 2, '.$thisfile_mpeg_audio['channelmode'].'.';
526                                                 return false;
527                                         }
528                                         break;
529
530                         }
531
532                 }
533
534
535                 if ($info['audio']['sample_rate'] > 0) {
536                         $thisfile_mpeg_audio['framelength'] = self::MPEGaudioFrameLength($thisfile_mpeg_audio['bitrate'], $thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['layer'], (int) $thisfile_mpeg_audio['padding'], $info['audio']['sample_rate']);
537                 }
538
539                 $nextframetestoffset = $offset + 1;
540                 if ($thisfile_mpeg_audio['bitrate'] != 'free') {
541
542                         $info['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];
543
544                         if (isset($thisfile_mpeg_audio['framelength'])) {
545                                 $nextframetestoffset = $offset + $thisfile_mpeg_audio['framelength'];
546                         } else {
547                                 $info['error'][] = 'Frame at offset('.$offset.') is has an invalid frame length.';
548                                 return false;
549                         }
550
551                 }
552
553                 $ExpectedNumberOfAudioBytes = 0;
554
555                 ////////////////////////////////////////////////////////////////////////////////////
556                 // Variable-bitrate headers
557
558                 if (substr($headerstring, 4 + 32, 4) == 'VBRI') {
559                         // Fraunhofer VBR header is hardcoded 'VBRI' at offset 0x24 (36)
560                         // specs taken from http://minnie.tuhs.org/pipermail/mp3encoder/2001-January/001800.html
561
562                         $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
563                         $thisfile_mpeg_audio['VBR_method']   = 'Fraunhofer';
564                         $info['audio']['codec']                = 'Fraunhofer';
565
566                         $SideInfoData = substr($headerstring, 4 + 2, 32);
567
568                         $FraunhoferVBROffset = 36;
569
570                         $thisfile_mpeg_audio['VBR_encoder_version']     = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  4, 2)); // VbriVersion
571                         $thisfile_mpeg_audio['VBR_encoder_delay']       = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  6, 2)); // VbriDelay
572                         $thisfile_mpeg_audio['VBR_quality']             = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  8, 2)); // VbriQuality
573                         $thisfile_mpeg_audio['VBR_bytes']               = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 10, 4)); // VbriStreamBytes
574                         $thisfile_mpeg_audio['VBR_frames']              = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 14, 4)); // VbriStreamFrames
575                         $thisfile_mpeg_audio['VBR_seek_offsets']        = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 18, 2)); // VbriTableSize
576                         $thisfile_mpeg_audio['VBR_seek_scale']          = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 20, 2)); // VbriTableScale
577                         $thisfile_mpeg_audio['VBR_entry_bytes']         = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 22, 2)); // VbriEntryBytes
578                         $thisfile_mpeg_audio['VBR_entry_frames']        = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 24, 2)); // VbriEntryFrames
579
580                         $ExpectedNumberOfAudioBytes = $thisfile_mpeg_audio['VBR_bytes'];
581
582                         $previousbyteoffset = $offset;
583                         for ($i = 0; $i < $thisfile_mpeg_audio['VBR_seek_offsets']; $i++) {
584                                 $Fraunhofer_OffsetN = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset, $thisfile_mpeg_audio['VBR_entry_bytes']));
585                                 $FraunhoferVBROffset += $thisfile_mpeg_audio['VBR_entry_bytes'];
586                                 $thisfile_mpeg_audio['VBR_offsets_relative'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']);
587                                 $thisfile_mpeg_audio['VBR_offsets_absolute'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']) + $previousbyteoffset;
588                                 $previousbyteoffset += $Fraunhofer_OffsetN;
589                         }
590
591
592                 } else {
593
594                         // Xing VBR header is hardcoded 'Xing' at a offset 0x0D (13), 0x15 (21) or 0x24 (36)
595                         // depending on MPEG layer and number of channels
596
597                         $VBRidOffset = self::XingVBRidOffset($thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['channelmode']);
598                         $SideInfoData = substr($headerstring, 4 + 2, $VBRidOffset - 4);
599
600                         if ((substr($headerstring, $VBRidOffset, strlen('Xing')) == 'Xing') || (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Info')) {
601                                 // 'Xing' is traditional Xing VBR frame
602                                 // 'Info' is LAME-encoded CBR (This was done to avoid CBR files to be recognized as traditional Xing VBR files by some decoders.)
603                                 // 'Info' *can* legally be used to specify a VBR file as well, however.
604
605                                 // http://www.multiweb.cz/twoinches/MP3inside.htm
606                                 //00..03 = "Xing" or "Info"
607                                 //04..07 = Flags:
608                                 //  0x01  Frames Flag     set if value for number of frames in file is stored
609                                 //  0x02  Bytes Flag      set if value for filesize in bytes is stored
610                                 //  0x04  TOC Flag        set if values for TOC are stored
611                                 //  0x08  VBR Scale Flag  set if values for VBR scale is stored
612                                 //08..11  Frames: Number of frames in file (including the first Xing/Info one)
613                                 //12..15  Bytes:  File length in Bytes
614                                 //16..115  TOC (Table of Contents):
615                                 //  Contains of 100 indexes (one Byte length) for easier lookup in file. Approximately solves problem with moving inside file.
616                                 //  Each Byte has a value according this formula:
617                                 //  (TOC[i] / 256) * fileLenInBytes
618                                 //  So if song lasts eg. 240 sec. and you want to jump to 60. sec. (and file is 5 000 000 Bytes length) you can use:
619                                 //  TOC[(60/240)*100] = TOC[25]
620                                 //  and corresponding Byte in file is then approximately at:
621                                 //  (TOC[25]/256) * 5000000
622                                 //116..119  VBR Scale
623
624
625                                 // should be safe to leave this at 'vbr' and let it be overriden to 'cbr' if a CBR preset/mode is used by LAME
626 //                              if (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Xing') {
627                                         $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
628                                         $thisfile_mpeg_audio['VBR_method']   = 'Xing';
629 //                              } else {
630 //                                      $ScanAsCBR = true;
631 //                                      $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
632 //                              }
633
634                                 $thisfile_mpeg_audio['xing_flags_raw'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 4, 4));
635
636                                 $thisfile_mpeg_audio['xing_flags']['frames']    = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000001);
637                                 $thisfile_mpeg_audio['xing_flags']['bytes']     = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000002);
638                                 $thisfile_mpeg_audio['xing_flags']['toc']       = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000004);
639                                 $thisfile_mpeg_audio['xing_flags']['vbr_scale'] = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000008);
640
641                                 if ($thisfile_mpeg_audio['xing_flags']['frames']) {
642                                         $thisfile_mpeg_audio['VBR_frames'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset +  8, 4));
643                                         //$thisfile_mpeg_audio['VBR_frames']--; // don't count header Xing/Info frame
644                                 }
645                                 if ($thisfile_mpeg_audio['xing_flags']['bytes']) {
646                                         $thisfile_mpeg_audio['VBR_bytes']  = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 12, 4));
647                                 }
648
649                                 //if (($thisfile_mpeg_audio['bitrate'] == 'free') && !empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {
650                                 if (!empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {
651
652                                         $framelengthfloat = $thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames'];
653
654                                         if ($thisfile_mpeg_audio['layer'] == '1') {
655                                                 // BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
656                                                 //$info['audio']['bitrate'] = ((($framelengthfloat / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
657                                                 $info['audio']['bitrate'] = ($framelengthfloat / 4) * $thisfile_mpeg_audio['sample_rate'] * (2 / $info['audio']['channels']) / 12;
658                                         } else {
659                                                 // Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
660                                                 //$info['audio']['bitrate'] = (($framelengthfloat - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
661                                                 $info['audio']['bitrate'] = $framelengthfloat * $thisfile_mpeg_audio['sample_rate'] * (2 / $info['audio']['channels']) / 144;
662                                         }
663                                         $thisfile_mpeg_audio['framelength'] = floor($framelengthfloat);
664                                 }
665
666                                 if ($thisfile_mpeg_audio['xing_flags']['toc']) {
667                                         $LAMEtocData = substr($headerstring, $VBRidOffset + 16, 100);
668                                         for ($i = 0; $i < 100; $i++) {
669                                                 $thisfile_mpeg_audio['toc'][$i] = ord($LAMEtocData{$i});
670                                         }
671                                 }
672                                 if ($thisfile_mpeg_audio['xing_flags']['vbr_scale']) {
673                                         $thisfile_mpeg_audio['VBR_scale'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 116, 4));
674                                 }
675
676
677                                 // http://gabriel.mp3-tech.org/mp3infotag.html
678                                 if (substr($headerstring, $VBRidOffset + 120, 4) == 'LAME') {
679
680                                         // shortcut
681                                         $thisfile_mpeg_audio['LAME'] = array();
682                                         $thisfile_mpeg_audio_lame    = &$thisfile_mpeg_audio['LAME'];
683
684
685                                         $thisfile_mpeg_audio_lame['long_version']  = substr($headerstring, $VBRidOffset + 120, 20);
686                                         $thisfile_mpeg_audio_lame['short_version'] = substr($thisfile_mpeg_audio_lame['long_version'], 0, 9);
687
688                                         if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.90') {
689
690                                                 // extra 11 chars are not part of version string when LAMEtag present
691                                                 unset($thisfile_mpeg_audio_lame['long_version']);
692
693                                                 // It the LAME tag was only introduced in LAME v3.90
694                                                 // http://www.hydrogenaudio.org/?act=ST&f=15&t=9933
695
696                                                 // Offsets of various bytes in http://gabriel.mp3-tech.org/mp3infotag.html
697                                                 // are assuming a 'Xing' identifier offset of 0x24, which is the case for
698                                                 // MPEG-1 non-mono, but not for other combinations
699                                                 $LAMEtagOffsetContant = $VBRidOffset - 0x24;
700
701                                                 // shortcuts
702                                                 $thisfile_mpeg_audio_lame['RGAD']    = array('track'=>array(), 'album'=>array());
703                                                 $thisfile_mpeg_audio_lame_RGAD       = &$thisfile_mpeg_audio_lame['RGAD'];
704                                                 $thisfile_mpeg_audio_lame_RGAD_track = &$thisfile_mpeg_audio_lame_RGAD['track'];
705                                                 $thisfile_mpeg_audio_lame_RGAD_album = &$thisfile_mpeg_audio_lame_RGAD['album'];
706                                                 $thisfile_mpeg_audio_lame['raw'] = array();
707                                                 $thisfile_mpeg_audio_lame_raw    = &$thisfile_mpeg_audio_lame['raw'];
708
709                                                 // byte $9B  VBR Quality
710                                                 // This field is there to indicate a quality level, although the scale was not precised in the original Xing specifications.
711                                                 // Actually overwrites original Xing bytes
712                                                 unset($thisfile_mpeg_audio['VBR_scale']);
713                                                 $thisfile_mpeg_audio_lame['vbr_quality'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0x9B, 1));
714
715                                                 // bytes $9C-$A4  Encoder short VersionString
716                                                 $thisfile_mpeg_audio_lame['short_version'] = substr($headerstring, $LAMEtagOffsetContant + 0x9C, 9);
717
718                                                 // byte $A5  Info Tag revision + VBR method
719                                                 $LAMEtagRevisionVBRmethod = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA5, 1));
720
721                                                 $thisfile_mpeg_audio_lame['tag_revision']   = ($LAMEtagRevisionVBRmethod & 0xF0) >> 4;
722                                                 $thisfile_mpeg_audio_lame_raw['vbr_method'] =  $LAMEtagRevisionVBRmethod & 0x0F;
723                                                 $thisfile_mpeg_audio_lame['vbr_method']     = self::LAMEvbrMethodLookup($thisfile_mpeg_audio_lame_raw['vbr_method']);
724                                                 $thisfile_mpeg_audio['bitrate_mode']        = substr($thisfile_mpeg_audio_lame['vbr_method'], 0, 3); // usually either 'cbr' or 'vbr', but truncates 'vbr-old / vbr-rh' to 'vbr'
725
726                                                 // byte $A6  Lowpass filter value
727                                                 $thisfile_mpeg_audio_lame['lowpass_frequency'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA6, 1)) * 100;
728
729                                                 // bytes $A7-$AE  Replay Gain
730                                                 // http://privatewww.essex.ac.uk/~djmrob/replaygain/rg_data_format.html
731                                                 // bytes $A7-$AA : 32 bit floating point "Peak signal amplitude"
732                                                 if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.94b') {
733                                                         // LAME 3.94a16 and later - 9.23 fixed point
734                                                         // ie 0x0059E2EE / (2^23) = 5890798 / 8388608 = 0.7022378444671630859375
735                                                         $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = (float) ((getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4))) / 8388608);
736                                                 } else {
737                                                         // LAME 3.94a15 and earlier - 32-bit floating point
738                                                         // Actually 3.94a16 will fall in here too and be WRONG, but is hard to detect 3.94a16 vs 3.94a15
739                                                         $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = getid3_lib::LittleEndian2Float(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4));
740                                                 }
741                                                 if ($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] == 0) {
742                                                         unset($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);
743                                                 } else {
744                                                         $thisfile_mpeg_audio_lame_RGAD['peak_db'] = getid3_lib::RGADamplitude2dB($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);
745                                                 }
746
747                                                 $thisfile_mpeg_audio_lame_raw['RGAD_track']      =   getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAB, 2));
748                                                 $thisfile_mpeg_audio_lame_raw['RGAD_album']      =   getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAD, 2));
749
750
751                                                 if ($thisfile_mpeg_audio_lame_raw['RGAD_track'] != 0) {
752
753                                                         $thisfile_mpeg_audio_lame_RGAD_track['raw']['name']        = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0xE000) >> 13;
754                                                         $thisfile_mpeg_audio_lame_RGAD_track['raw']['originator']  = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x1C00) >> 10;
755                                                         $thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit']    = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x0200) >> 9;
756                                                         $thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'] =  $thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x01FF;
757                                                         $thisfile_mpeg_audio_lame_RGAD_track['name']       = getid3_lib::RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['name']);
758                                                         $thisfile_mpeg_audio_lame_RGAD_track['originator'] = getid3_lib::RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['originator']);
759                                                         $thisfile_mpeg_audio_lame_RGAD_track['gain_db']    = getid3_lib::RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit']);
760
761                                                         if (!empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'])) {
762                                                                 $info['replay_gain']['track']['peak']   = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];
763                                                         }
764                                                         $info['replay_gain']['track']['originator'] = $thisfile_mpeg_audio_lame_RGAD_track['originator'];
765                                                         $info['replay_gain']['track']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_track['gain_db'];
766                                                 } else {
767                                                         unset($thisfile_mpeg_audio_lame_RGAD['track']);
768                                                 }
769                                                 if ($thisfile_mpeg_audio_lame_raw['RGAD_album'] != 0) {
770
771                                                         $thisfile_mpeg_audio_lame_RGAD_album['raw']['name']        = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0xE000) >> 13;
772                                                         $thisfile_mpeg_audio_lame_RGAD_album['raw']['originator']  = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x1C00) >> 10;
773                                                         $thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit']    = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x0200) >> 9;
774                                                         $thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'] = $thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x01FF;
775                                                         $thisfile_mpeg_audio_lame_RGAD_album['name']       = getid3_lib::RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['name']);
776                                                         $thisfile_mpeg_audio_lame_RGAD_album['originator'] = getid3_lib::RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['originator']);
777                                                         $thisfile_mpeg_audio_lame_RGAD_album['gain_db']    = getid3_lib::RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit']);
778
779                                                         if (!empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'])) {
780                                                                 $info['replay_gain']['album']['peak']   = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];
781                                                         }
782                                                         $info['replay_gain']['album']['originator'] = $thisfile_mpeg_audio_lame_RGAD_album['originator'];
783                                                         $info['replay_gain']['album']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_album['gain_db'];
784                                                 } else {
785                                                         unset($thisfile_mpeg_audio_lame_RGAD['album']);
786                                                 }
787                                                 if (empty($thisfile_mpeg_audio_lame_RGAD)) {
788                                                         unset($thisfile_mpeg_audio_lame['RGAD']);
789                                                 }
790
791
792                                                 // byte $AF  Encoding flags + ATH Type
793                                                 $EncodingFlagsATHtype = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAF, 1));
794                                                 $thisfile_mpeg_audio_lame['encoding_flags']['nspsytune']   = (bool) ($EncodingFlagsATHtype & 0x10);
795                                                 $thisfile_mpeg_audio_lame['encoding_flags']['nssafejoint'] = (bool) ($EncodingFlagsATHtype & 0x20);
796                                                 $thisfile_mpeg_audio_lame['encoding_flags']['nogap_next']  = (bool) ($EncodingFlagsATHtype & 0x40);
797                                                 $thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev']  = (bool) ($EncodingFlagsATHtype & 0x80);
798                                                 $thisfile_mpeg_audio_lame['ath_type']                      =         $EncodingFlagsATHtype & 0x0F;
799
800                                                 // byte $B0  if ABR {specified bitrate} else {minimal bitrate}
801                                                 $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB0, 1));
802                                                 if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 2) { // Average BitRate (ABR)
803                                                         $thisfile_mpeg_audio_lame['bitrate_abr'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];
804                                                 } elseif ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1) { // Constant BitRate (CBR)
805                                                         // ignore
806                                                 } elseif ($thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] > 0) { // Variable BitRate (VBR) - minimum bitrate
807                                                         $thisfile_mpeg_audio_lame['bitrate_min'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];
808                                                 }
809
810                                                 // bytes $B1-$B3  Encoder delays
811                                                 $EncoderDelays = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB1, 3));
812                                                 $thisfile_mpeg_audio_lame['encoder_delay'] = ($EncoderDelays & 0xFFF000) >> 12;
813                                                 $thisfile_mpeg_audio_lame['end_padding']   =  $EncoderDelays & 0x000FFF;
814
815                                                 // byte $B4  Misc
816                                                 $MiscByte = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB4, 1));
817                                                 $thisfile_mpeg_audio_lame_raw['noise_shaping']       = ($MiscByte & 0x03);
818                                                 $thisfile_mpeg_audio_lame_raw['stereo_mode']         = ($MiscByte & 0x1C) >> 2;
819                                                 $thisfile_mpeg_audio_lame_raw['not_optimal_quality'] = ($MiscByte & 0x20) >> 5;
820                                                 $thisfile_mpeg_audio_lame_raw['source_sample_freq']  = ($MiscByte & 0xC0) >> 6;
821                                                 $thisfile_mpeg_audio_lame['noise_shaping']       = $thisfile_mpeg_audio_lame_raw['noise_shaping'];
822                                                 $thisfile_mpeg_audio_lame['stereo_mode']         = self::LAMEmiscStereoModeLookup($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                                                 $thisfile_mpeg_audio_lame['source_sample_freq']  = self::LAMEmiscSourceSampleFrequencyLookup($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                                                 $thisfile_mpeg_audio_lame['surround_info']     = self::LAMEsurroundInfoLookup($thisfile_mpeg_audio_lame_raw['surround_info']);
836                                                 $thisfile_mpeg_audio_lame['preset_used_id']    = ($PresetSurroundBytes & 0x07FF);
837                                                 $thisfile_mpeg_audio_lame['preset_used']       = self::LAMEpresetUsedLookup($thisfile_mpeg_audio_lame);
838                                                 if (!empty($thisfile_mpeg_audio_lame['preset_used_id']) && empty($thisfile_mpeg_audio_lame['preset_used'])) {
839                                                         $info['warning'][] = 'Unknown LAME preset used ('.$thisfile_mpeg_audio_lame['preset_used_id'].') - please report to info@getid3.org';
840                                                 }
841                                                 if (($thisfile_mpeg_audio_lame['short_version'] == 'LAME3.90.') && !empty($thisfile_mpeg_audio_lame['preset_used_id'])) {
842                                                         // this may change if 3.90.4 ever comes out
843                                                         $thisfile_mpeg_audio_lame['short_version'] = 'LAME3.90.3';
844                                                 }
845
846                                                 // bytes $B8-$BB  MusicLength
847                                                 $thisfile_mpeg_audio_lame['audio_bytes'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB8, 4));
848                                                 $ExpectedNumberOfAudioBytes = (($thisfile_mpeg_audio_lame['audio_bytes'] > 0) ? $thisfile_mpeg_audio_lame['audio_bytes'] : $thisfile_mpeg_audio['VBR_bytes']);
849
850                                                 // bytes $BC-$BD  MusicCRC
851                                                 $thisfile_mpeg_audio_lame['music_crc']    = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBC, 2));
852
853                                                 // bytes $BE-$BF  CRC-16 of Info Tag
854                                                 $thisfile_mpeg_audio_lame['lame_tag_crc'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBE, 2));
855
856
857                                                 // LAME CBR
858                                                 if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1) {
859
860                                                         $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
861                                                         $thisfile_mpeg_audio['bitrate'] = self::ClosestStandardMP3Bitrate($thisfile_mpeg_audio['bitrate']);
862                                                         $info['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];
863                                                         //if (empty($thisfile_mpeg_audio['bitrate']) || (!empty($thisfile_mpeg_audio_lame['bitrate_min']) && ($thisfile_mpeg_audio_lame['bitrate_min'] != 255))) {
864                                                         //      $thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio_lame['bitrate_min'];
865                                                         //}
866
867                                                 }
868
869                                         }
870                                 }
871
872                         } else {
873
874                                 // not Fraunhofer or Xing VBR methods, most likely CBR (but could be VBR with no header)
875                                 $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
876                                 if ($recursivesearch) {
877                                         $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
878                                         if ($this->RecursiveFrameScanning($offset, $nextframetestoffset, true)) {
879                                                 $recursivesearch = false;
880                                                 $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
881                                         }
882                                         if ($thisfile_mpeg_audio['bitrate_mode'] == 'vbr') {
883                                                 $info['warning'][] = 'VBR file with no VBR header. Bitrate values calculated from actual frame bitrates.';
884                                         }
885                                 }
886
887                         }
888
889                 }
890
891                 if (($ExpectedNumberOfAudioBytes > 0) && ($ExpectedNumberOfAudioBytes != ($info['avdataend'] - $info['avdataoffset']))) {
892                         if ($ExpectedNumberOfAudioBytes > ($info['avdataend'] - $info['avdataoffset'])) {
893                                 if (isset($info['fileformat']) && ($info['fileformat'] == 'riff')) {
894                                         // ignore, audio data is broken into chunks so will always be data "missing"
895                                 } elseif (($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])) == 1) {
896                                         $info['warning'][] = 'Last byte of data truncated (this is a known bug in Meracl ID3 Tag Writer before v1.3.5)';
897                                 } else {
898                                         $info['warning'][] = 'Probable truncated file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, only found '.($info['avdataend'] - $info['avdataoffset']).' (short by '.($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])).' bytes)';
899                                 }
900                         } else {
901                                 if ((($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes) == 1) {
902                                 //      $prenullbytefileoffset = ftell($this->getid3->fp);
903                                 //      fseek($this->getid3->fp, $info['avdataend'], SEEK_SET);
904                                 //      $PossibleNullByte = fread($this->getid3->fp, 1);
905                                 //      fseek($this->getid3->fp, $prenullbytefileoffset, SEEK_SET);
906                                 //      if ($PossibleNullByte === "\x00") {
907                                                 $info['avdataend']--;
908                                 //              $info['warning'][] = 'Extra null byte at end of MP3 data assumed to be RIFF padding and therefore ignored';
909                                 //      } else {
910                                 //              $info['warning'][] = 'Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']).' ('.(($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)';
911                                 //      }
912                                 } else {
913                                         $info['warning'][] = 'Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']).' ('.(($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)';
914                                 }
915                         }
916                 }
917
918                 if (($thisfile_mpeg_audio['bitrate'] == 'free') && empty($info['audio']['bitrate'])) {
919                         if (($offset == $info['avdataoffset']) && empty($thisfile_mpeg_audio['VBR_frames'])) {
920                                 $framebytelength = $this->FreeFormatFrameLength($offset, true);
921                                 if ($framebytelength > 0) {
922                                         $thisfile_mpeg_audio['framelength'] = $framebytelength;
923                                         if ($thisfile_mpeg_audio['layer'] == '1') {
924                                                 // BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
925                                                 $info['audio']['bitrate'] = ((($framebytelength / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
926                                         } else {
927                                                 // Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
928                                                 $info['audio']['bitrate'] = (($framebytelength - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
929                                         }
930                                 } else {
931                                         $info['error'][] = 'Error calculating frame length of free-format MP3 without Xing/LAME header';
932                                 }
933                         }
934                 }
935
936                 if (isset($thisfile_mpeg_audio['VBR_frames']) ? $thisfile_mpeg_audio['VBR_frames'] : '') {
937                         switch ($thisfile_mpeg_audio['bitrate_mode']) {
938                                 case 'vbr':
939                                 case 'abr':
940                                         $bytes_per_frame = 1152;
941                                         if (($thisfile_mpeg_audio['version'] == '1') && ($thisfile_mpeg_audio['layer'] == 1)) {
942                                                 $bytes_per_frame = 384;
943                                         } elseif ((($thisfile_mpeg_audio['version'] == '2') || ($thisfile_mpeg_audio['version'] == '2.5')) && ($thisfile_mpeg_audio['layer'] == 3)) {
944                                                 $bytes_per_frame = 576;
945                                         }
946                                         $thisfile_mpeg_audio['VBR_bitrate'] = (isset($thisfile_mpeg_audio['VBR_bytes']) ? (($thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames']) * 8) * ($info['audio']['sample_rate'] / $bytes_per_frame) : 0);
947                                         if ($thisfile_mpeg_audio['VBR_bitrate'] > 0) {
948                                                 $info['audio']['bitrate']         = $thisfile_mpeg_audio['VBR_bitrate'];
949                                                 $thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio['VBR_bitrate']; // to avoid confusion
950                                         }
951                                         break;
952                         }
953                 }
954
955                 // End variable-bitrate headers
956                 ////////////////////////////////////////////////////////////////////////////////////
957
958                 if ($recursivesearch) {
959
960                         if (!$this->RecursiveFrameScanning($offset, $nextframetestoffset, $ScanAsCBR)) {
961                                 return false;
962                         }
963
964                 }
965
966
967                 //if (false) {
968                 //    // experimental side info parsing section - not returning anything useful yet
969                 //
970                 //    $SideInfoBitstream = getid3_lib::BigEndian2Bin($SideInfoData);
971                 //    $SideInfoOffset = 0;
972                 //
973                 //    if ($thisfile_mpeg_audio['version'] == '1') {
974                 //        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
975                 //            // MPEG-1 (mono)
976                 //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
977                 //            $SideInfoOffset += 9;
978                 //            $SideInfoOffset += 5;
979                 //        } else {
980                 //            // MPEG-1 (stereo, joint-stereo, dual-channel)
981                 //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
982                 //            $SideInfoOffset += 9;
983                 //            $SideInfoOffset += 3;
984                 //        }
985                 //    } else { // 2 or 2.5
986                 //        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
987                 //            // MPEG-2, MPEG-2.5 (mono)
988                 //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
989                 //            $SideInfoOffset += 8;
990                 //            $SideInfoOffset += 1;
991                 //        } else {
992                 //            // MPEG-2, MPEG-2.5 (stereo, joint-stereo, dual-channel)
993                 //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
994                 //            $SideInfoOffset += 8;
995                 //            $SideInfoOffset += 2;
996                 //        }
997                 //    }
998                 //
999                 //    if ($thisfile_mpeg_audio['version'] == '1') {
1000                 //        for ($channel = 0; $channel < $info['audio']['channels']; $channel++) {
1001                 //            for ($scfsi_band = 0; $scfsi_band < 4; $scfsi_band++) {
1002                 //                $thisfile_mpeg_audio['scfsi'][$channel][$scfsi_band] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1003                 //                $SideInfoOffset += 2;
1004                 //            }
1005                 //        }
1006                 //    }
1007                 //    for ($granule = 0; $granule < (($thisfile_mpeg_audio['version'] == '1') ? 2 : 1); $granule++) {
1008                 //        for ($channel = 0; $channel < $info['audio']['channels']; $channel++) {
1009                 //            $thisfile_mpeg_audio['part2_3_length'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 12);
1010                 //            $SideInfoOffset += 12;
1011                 //            $thisfile_mpeg_audio['big_values'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1012                 //            $SideInfoOffset += 9;
1013                 //            $thisfile_mpeg_audio['global_gain'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 8);
1014                 //            $SideInfoOffset += 8;
1015                 //            if ($thisfile_mpeg_audio['version'] == '1') {
1016                 //                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
1017                 //                $SideInfoOffset += 4;
1018                 //            } else {
1019                 //                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1020                 //                $SideInfoOffset += 9;
1021                 //            }
1022                 //            $thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1023                 //            $SideInfoOffset += 1;
1024                 //
1025                 //            if ($thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] == '1') {
1026                 //
1027                 //                $thisfile_mpeg_audio['block_type'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 2);
1028                 //                $SideInfoOffset += 2;
1029                 //                $thisfile_mpeg_audio['mixed_block_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1030                 //                $SideInfoOffset += 1;
1031                 //
1032                 //                for ($region = 0; $region < 2; $region++) {
1033                 //                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
1034                 //                    $SideInfoOffset += 5;
1035                 //                }
1036                 //                $thisfile_mpeg_audio['table_select'][$granule][$channel][2] = 0;
1037                 //
1038                 //                for ($window = 0; $window < 3; $window++) {
1039                 //                    $thisfile_mpeg_audio['subblock_gain'][$granule][$channel][$window] = substr($SideInfoBitstream, $SideInfoOffset, 3);
1040                 //                    $SideInfoOffset += 3;
1041                 //                }
1042                 //
1043                 //            } else {
1044                 //
1045                 //                for ($region = 0; $region < 3; $region++) {
1046                 //                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
1047                 //                    $SideInfoOffset += 5;
1048                 //                }
1049                 //
1050                 //                $thisfile_mpeg_audio['region0_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
1051                 //                $SideInfoOffset += 4;
1052                 //                $thisfile_mpeg_audio['region1_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 3);
1053                 //                $SideInfoOffset += 3;
1054                 //                $thisfile_mpeg_audio['block_type'][$granule][$channel] = 0;
1055                 //            }
1056                 //
1057                 //            if ($thisfile_mpeg_audio['version'] == '1') {
1058                 //                $thisfile_mpeg_audio['preflag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1059                 //                $SideInfoOffset += 1;
1060                 //            }
1061                 //            $thisfile_mpeg_audio['scalefac_scale'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1062                 //            $SideInfoOffset += 1;
1063                 //            $thisfile_mpeg_audio['count1table_select'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1064                 //            $SideInfoOffset += 1;
1065                 //        }
1066                 //    }
1067                 //}
1068
1069                 return true;
1070         }
1071
1072         public function RecursiveFrameScanning(&$offset, &$nextframetestoffset, $ScanAsCBR) {
1073                 $info = &$this->getid3->info;
1074                 $firstframetestarray = array('error'=>'', 'warning'=>'', 'avdataend'=>$info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1075                 $this->decodeMPEGaudioHeader($offset, $firstframetestarray, false);
1076
1077                 for ($i = 0; $i < GETID3_MP3_VALID_CHECK_FRAMES; $i++) {
1078                         // check next GETID3_MP3_VALID_CHECK_FRAMES frames for validity, to make sure we haven't run across a false synch
1079                         if (($nextframetestoffset + 4) >= $info['avdataend']) {
1080                                 // end of file
1081                                 return true;
1082                         }
1083
1084                         $nextframetestarray = array('error'=>'', 'warning'=>'', 'avdataend'=>$info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1085                         if ($this->decodeMPEGaudioHeader($nextframetestoffset, $nextframetestarray, false)) {
1086                                 if ($ScanAsCBR) {
1087                                         // force CBR mode, used for trying to pick out invalid audio streams with valid(?) VBR headers, or VBR streams with no VBR header
1088                                         if (!isset($nextframetestarray['mpeg']['audio']['bitrate']) || !isset($firstframetestarray['mpeg']['audio']['bitrate']) || ($nextframetestarray['mpeg']['audio']['bitrate'] != $firstframetestarray['mpeg']['audio']['bitrate'])) {
1089                                                 return false;
1090                                         }
1091                                 }
1092
1093
1094                                 // next frame is OK, get ready to check the one after that
1095                                 if (isset($nextframetestarray['mpeg']['audio']['framelength']) && ($nextframetestarray['mpeg']['audio']['framelength'] > 0)) {
1096                                         $nextframetestoffset += $nextframetestarray['mpeg']['audio']['framelength'];
1097                                 } else {
1098                                         $info['error'][] = 'Frame at offset ('.$offset.') is has an invalid frame length.';
1099                                         return false;
1100                                 }
1101
1102                         } elseif (!empty($firstframetestarray['mpeg']['audio']['framelength']) && (($nextframetestoffset + $firstframetestarray['mpeg']['audio']['framelength']) > $info['avdataend'])) {
1103
1104                                 // it's not the end of the file, but there's not enough data left for another frame, so assume it's garbage/padding and return OK
1105                                 return true;
1106
1107                         } else {
1108
1109                                 // next frame is not valid, note the error and fail, so scanning can contiue for a valid frame sequence
1110                                 $info['warning'][] = 'Frame at offset ('.$offset.') is valid, but the next one at ('.$nextframetestoffset.') is not.';
1111
1112                                 return false;
1113                         }
1114                 }
1115                 return true;
1116         }
1117
1118         public function FreeFormatFrameLength($offset, $deepscan=false) {
1119                 $info = &$this->getid3->info;
1120
1121                 fseek($this->getid3->fp, $offset, SEEK_SET);
1122                 $MPEGaudioData = fread($this->getid3->fp, 32768);
1123
1124                 $SyncPattern1 = substr($MPEGaudioData, 0, 4);
1125                 // may be different pattern due to padding
1126                 $SyncPattern2 = $SyncPattern1{0}.$SyncPattern1{1}.chr(ord($SyncPattern1{2}) | 0x02).$SyncPattern1{3};
1127                 if ($SyncPattern2 === $SyncPattern1) {
1128                         $SyncPattern2 = $SyncPattern1{0}.$SyncPattern1{1}.chr(ord($SyncPattern1{2}) & 0xFD).$SyncPattern1{3};
1129                 }
1130
1131                 $framelength = false;
1132                 $framelength1 = strpos($MPEGaudioData, $SyncPattern1, 4);
1133                 $framelength2 = strpos($MPEGaudioData, $SyncPattern2, 4);
1134                 if ($framelength1 > 4) {
1135                         $framelength = $framelength1;
1136                 }
1137                 if (($framelength2 > 4) && ($framelength2 < $framelength1)) {
1138                         $framelength = $framelength2;
1139                 }
1140                 if (!$framelength) {
1141
1142                         // LAME 3.88 has a different value for modeextension on the first frame vs the rest
1143                         $framelength1 = strpos($MPEGaudioData, substr($SyncPattern1, 0, 3), 4);
1144                         $framelength2 = strpos($MPEGaudioData, substr($SyncPattern2, 0, 3), 4);
1145
1146                         if ($framelength1 > 4) {
1147                                 $framelength = $framelength1;
1148                         }
1149                         if (($framelength2 > 4) && ($framelength2 < $framelength1)) {
1150                                 $framelength = $framelength2;
1151                         }
1152                         if (!$framelength) {
1153                                 $info['error'][] = 'Cannot find next free-format synch pattern ('.getid3_lib::PrintHexBytes($SyncPattern1).' or '.getid3_lib::PrintHexBytes($SyncPattern2).') after offset '.$offset;
1154                                 return false;
1155                         } else {
1156                                 $info['warning'][] = 'ModeExtension varies between first frame and other frames (known free-format issue in LAME 3.88)';
1157                                 $info['audio']['codec']   = 'LAME';
1158                                 $info['audio']['encoder'] = 'LAME3.88';
1159                                 $SyncPattern1 = substr($SyncPattern1, 0, 3);
1160                                 $SyncPattern2 = substr($SyncPattern2, 0, 3);
1161                         }
1162                 }
1163
1164                 if ($deepscan) {
1165
1166                         $ActualFrameLengthValues = array();
1167                         $nextoffset = $offset + $framelength;
1168                         while ($nextoffset < ($info['avdataend'] - 6)) {
1169                                 fseek($this->getid3->fp, $nextoffset - 1, SEEK_SET);
1170                                 $NextSyncPattern = fread($this->getid3->fp, 6);
1171                                 if ((substr($NextSyncPattern, 1, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 1, strlen($SyncPattern2)) == $SyncPattern2)) {
1172                                         // good - found where expected
1173                                         $ActualFrameLengthValues[] = $framelength;
1174                                 } elseif ((substr($NextSyncPattern, 0, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 0, strlen($SyncPattern2)) == $SyncPattern2)) {
1175                                         // ok - found one byte earlier than expected (last frame wasn't padded, first frame was)
1176                                         $ActualFrameLengthValues[] = ($framelength - 1);
1177                                         $nextoffset--;
1178                                 } elseif ((substr($NextSyncPattern, 2, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 2, strlen($SyncPattern2)) == $SyncPattern2)) {
1179                                         // ok - found one byte later than expected (last frame was padded, first frame wasn't)
1180                                         $ActualFrameLengthValues[] = ($framelength + 1);
1181                                         $nextoffset++;
1182                                 } else {
1183                                         $info['error'][] = 'Did not find expected free-format sync pattern at offset '.$nextoffset;
1184                                         return false;
1185                                 }
1186                                 $nextoffset += $framelength;
1187                         }
1188                         if (count($ActualFrameLengthValues) > 0) {
1189                                 $framelength = intval(round(array_sum($ActualFrameLengthValues) / count($ActualFrameLengthValues)));
1190                         }
1191                 }
1192                 return $framelength;
1193         }
1194
1195         public function getOnlyMPEGaudioInfoBruteForce() {
1196                 $MPEGaudioHeaderDecodeCache   = array();
1197                 $MPEGaudioHeaderValidCache    = array();
1198                 $MPEGaudioHeaderLengthCache   = array();
1199                 $MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();
1200                 $MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();
1201                 $MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();
1202                 $MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();
1203                 $MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();
1204                 $MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
1205                 $MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();
1206                 $LongMPEGversionLookup        = array();
1207                 $LongMPEGlayerLookup          = array();
1208                 $LongMPEGbitrateLookup        = array();
1209                 $LongMPEGpaddingLookup        = array();
1210                 $LongMPEGfrequencyLookup      = array();
1211                 $Distribution['bitrate']      = array();
1212                 $Distribution['frequency']    = array();
1213                 $Distribution['layer']        = array();
1214                 $Distribution['version']      = array();
1215                 $Distribution['padding']      = array();
1216
1217                 $info = &$this->getid3->info;
1218                 fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
1219
1220                 $max_frames_scan = 5000;
1221                 $frames_scanned  = 0;
1222
1223                 $previousvalidframe = $info['avdataoffset'];
1224                 while (ftell($this->getid3->fp) < $info['avdataend']) {
1225                         set_time_limit(30);
1226                         $head4 = fread($this->getid3->fp, 4);
1227                         if (strlen($head4) < 4) {
1228                                 break;
1229                         }
1230                         if ($head4{0} != "\xFF") {
1231                                 for ($i = 1; $i < 4; $i++) {
1232                                         if ($head4{$i} == "\xFF") {
1233                                                 fseek($this->getid3->fp, $i - 4, SEEK_CUR);
1234                                                 continue 2;
1235                                         }
1236                                 }
1237                                 continue;
1238                         }
1239                         if (!isset($MPEGaudioHeaderDecodeCache[$head4])) {
1240                                 $MPEGaudioHeaderDecodeCache[$head4] = self::MPEGaudioHeaderDecode($head4);
1241                         }
1242                         if (!isset($MPEGaudioHeaderValidCache[$head4])) {
1243                                 $MPEGaudioHeaderValidCache[$head4] = self::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$head4], false, false);
1244                         }
1245                         if ($MPEGaudioHeaderValidCache[$head4]) {
1246
1247                                 if (!isset($MPEGaudioHeaderLengthCache[$head4])) {
1248                                         $LongMPEGversionLookup[$head4]   = $MPEGaudioVersionLookup[$MPEGaudioHeaderDecodeCache[$head4]['version']];
1249                                         $LongMPEGlayerLookup[$head4]     = $MPEGaudioLayerLookup[$MPEGaudioHeaderDecodeCache[$head4]['layer']];
1250                                         $LongMPEGbitrateLookup[$head4]   = $MPEGaudioBitrateLookup[$LongMPEGversionLookup[$head4]][$LongMPEGlayerLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['bitrate']];
1251                                         $LongMPEGpaddingLookup[$head4]   = (bool) $MPEGaudioHeaderDecodeCache[$head4]['padding'];
1252                                         $LongMPEGfrequencyLookup[$head4] = $MPEGaudioFrequencyLookup[$LongMPEGversionLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['sample_rate']];
1253                                         $MPEGaudioHeaderLengthCache[$head4] = self::MPEGaudioFrameLength(
1254                                                 $LongMPEGbitrateLookup[$head4],
1255                                                 $LongMPEGversionLookup[$head4],
1256                                                 $LongMPEGlayerLookup[$head4],
1257                                                 $LongMPEGpaddingLookup[$head4],
1258                                                 $LongMPEGfrequencyLookup[$head4]);
1259                                 }
1260                                 if ($MPEGaudioHeaderLengthCache[$head4] > 4) {
1261                                         $WhereWeWere = ftell($this->getid3->fp);
1262                                         fseek($this->getid3->fp, $MPEGaudioHeaderLengthCache[$head4] - 4, SEEK_CUR);
1263                                         $next4 = fread($this->getid3->fp, 4);
1264                                         if ($next4{0} == "\xFF") {
1265                                                 if (!isset($MPEGaudioHeaderDecodeCache[$next4])) {
1266                                                         $MPEGaudioHeaderDecodeCache[$next4] = self::MPEGaudioHeaderDecode($next4);
1267                                                 }
1268                                                 if (!isset($MPEGaudioHeaderValidCache[$next4])) {
1269                                                         $MPEGaudioHeaderValidCache[$next4] = self::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$next4], false, false);
1270                                                 }
1271                                                 if ($MPEGaudioHeaderValidCache[$next4]) {
1272                                                         fseek($this->getid3->fp, -4, SEEK_CUR);
1273
1274                                                         getid3_lib::safe_inc($Distribution['bitrate'][$LongMPEGbitrateLookup[$head4]]);
1275                                                         getid3_lib::safe_inc($Distribution['layer'][$LongMPEGlayerLookup[$head4]]);
1276                                                         getid3_lib::safe_inc($Distribution['version'][$LongMPEGversionLookup[$head4]]);
1277                                                         getid3_lib::safe_inc($Distribution['padding'][intval($LongMPEGpaddingLookup[$head4])]);
1278                                                         getid3_lib::safe_inc($Distribution['frequency'][$LongMPEGfrequencyLookup[$head4]]);
1279                                                         if ($max_frames_scan && (++$frames_scanned >= $max_frames_scan)) {
1280                                                                 $pct_data_scanned = (ftell($this->getid3->fp) - $info['avdataoffset']) / ($info['avdataend'] - $info['avdataoffset']);
1281                                                                 $info['warning'][] = 'too many MPEG audio frames to scan, only scanned first '.$max_frames_scan.' frames ('.number_format($pct_data_scanned * 100, 1).'% of file) and extrapolated distribution, playtime and bitrate may be incorrect.';
1282                                                                 foreach ($Distribution as $key1 => $value1) {
1283                                                                         foreach ($value1 as $key2 => $value2) {
1284                                                                                 $Distribution[$key1][$key2] = round($value2 / $pct_data_scanned);
1285                                                                         }
1286                                                                 }
1287                                                                 break;
1288                                                         }
1289                                                         continue;
1290                                                 }
1291                                         }
1292                                         unset($next4);
1293                                         fseek($this->getid3->fp, $WhereWeWere - 3, SEEK_SET);
1294                                 }
1295
1296                         }
1297                 }
1298                 foreach ($Distribution as $key => $value) {
1299                         ksort($Distribution[$key], SORT_NUMERIC);
1300                 }
1301                 ksort($Distribution['version'], SORT_STRING);
1302                 $info['mpeg']['audio']['bitrate_distribution']   = $Distribution['bitrate'];
1303                 $info['mpeg']['audio']['frequency_distribution'] = $Distribution['frequency'];
1304                 $info['mpeg']['audio']['layer_distribution']     = $Distribution['layer'];
1305                 $info['mpeg']['audio']['version_distribution']   = $Distribution['version'];
1306                 $info['mpeg']['audio']['padding_distribution']   = $Distribution['padding'];
1307                 if (count($Distribution['version']) > 1) {
1308                         $info['error'][] = 'Corrupt file - more than one MPEG version detected';
1309                 }
1310                 if (count($Distribution['layer']) > 1) {
1311                         $info['error'][] = 'Corrupt file - more than one MPEG layer detected';
1312                 }
1313                 if (count($Distribution['frequency']) > 1) {
1314                         $info['error'][] = 'Corrupt file - more than one MPEG sample rate detected';
1315                 }
1316
1317
1318                 $bittotal = 0;
1319                 foreach ($Distribution['bitrate'] as $bitratevalue => $bitratecount) {
1320                         if ($bitratevalue != 'free') {
1321                                 $bittotal += ($bitratevalue * $bitratecount);
1322                         }
1323                 }
1324                 $info['mpeg']['audio']['frame_count']  = array_sum($Distribution['bitrate']);
1325                 if ($info['mpeg']['audio']['frame_count'] == 0) {
1326                         $info['error'][] = 'no MPEG audio frames found';
1327                         return false;
1328                 }
1329                 $info['mpeg']['audio']['bitrate']      = ($bittotal / $info['mpeg']['audio']['frame_count']);
1330                 $info['mpeg']['audio']['bitrate_mode'] = ((count($Distribution['bitrate']) > 0) ? 'vbr' : 'cbr');
1331                 $info['mpeg']['audio']['sample_rate']  = getid3_lib::array_max($Distribution['frequency'], true);
1332
1333                 $info['audio']['bitrate']      = $info['mpeg']['audio']['bitrate'];
1334                 $info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
1335                 $info['audio']['sample_rate']  = $info['mpeg']['audio']['sample_rate'];
1336                 $info['audio']['dataformat']   = 'mp'.getid3_lib::array_max($Distribution['layer'], true);
1337                 $info['fileformat']            = $info['audio']['dataformat'];
1338
1339                 return true;
1340         }
1341
1342
1343         public function getOnlyMPEGaudioInfo($avdataoffset, $BitrateHistogram=false) {
1344                 // looks for synch, decodes MPEG audio header
1345
1346                 $info = &$this->getid3->info;
1347
1348                 static $MPEGaudioVersionLookup;
1349                 static $MPEGaudioLayerLookup;
1350                 static $MPEGaudioBitrateLookup;
1351                 if (empty($MPEGaudioVersionLookup)) {
1352                    $MPEGaudioVersionLookup = self::MPEGaudioVersionArray();
1353                    $MPEGaudioLayerLookup   = self::MPEGaudioLayerArray();
1354                    $MPEGaudioBitrateLookup = self::MPEGaudioBitrateArray();
1355
1356                 }
1357
1358                 fseek($this->getid3->fp, $avdataoffset, SEEK_SET);
1359                 $sync_seek_buffer_size = min(128 * 1024, $info['avdataend'] - $avdataoffset);
1360                 if ($sync_seek_buffer_size <= 0) {
1361                         $info['error'][] = 'Invalid $sync_seek_buffer_size at offset '.$avdataoffset;
1362                         return false;
1363                 }
1364                 $header = fread($this->getid3->fp, $sync_seek_buffer_size);
1365                 $sync_seek_buffer_size = strlen($header);
1366                 $SynchSeekOffset = 0;
1367                 while ($SynchSeekOffset < $sync_seek_buffer_size) {
1368                         if ((($avdataoffset + $SynchSeekOffset)  < $info['avdataend']) && !feof($this->getid3->fp)) {
1369
1370                                 if ($SynchSeekOffset > $sync_seek_buffer_size) {
1371                                         // if a synch's not found within the first 128k bytes, then give up
1372                                         $info['error'][] = 'Could not find valid MPEG audio synch within the first '.round($sync_seek_buffer_size / 1024).'kB';
1373                                         if (isset($info['audio']['bitrate'])) {
1374                                                 unset($info['audio']['bitrate']);
1375                                         }
1376                                         if (isset($info['mpeg']['audio'])) {
1377                                                 unset($info['mpeg']['audio']);
1378                                         }
1379                                         if (empty($info['mpeg'])) {
1380                                                 unset($info['mpeg']);
1381                                         }
1382                                         return false;
1383
1384                                 } elseif (feof($this->getid3->fp)) {
1385
1386                                         $info['error'][] = 'Could not find valid MPEG audio synch before end of file';
1387                                         if (isset($info['audio']['bitrate'])) {
1388                                                 unset($info['audio']['bitrate']);
1389                                         }
1390                                         if (isset($info['mpeg']['audio'])) {
1391                                                 unset($info['mpeg']['audio']);
1392                                         }
1393                                         if (isset($info['mpeg']) && (!is_array($info['mpeg']) || (count($info['mpeg']) == 0))) {
1394                                                 unset($info['mpeg']);
1395                                         }
1396                                         return false;
1397                                 }
1398                         }
1399
1400                         if (($SynchSeekOffset + 1) >= strlen($header)) {
1401                                 $info['error'][] = 'Could not find valid MPEG synch before end of file';
1402                                 return false;
1403                         }
1404
1405                         if (($header{$SynchSeekOffset} == "\xFF") && ($header{($SynchSeekOffset + 1)} > "\xE0")) { // synch detected
1406                                 if (!isset($FirstFrameThisfileInfo) && !isset($info['mpeg']['audio'])) {
1407                                         $FirstFrameThisfileInfo = $info;
1408                                         $FirstFrameAVDataOffset = $avdataoffset + $SynchSeekOffset;
1409                                         if (!$this->decodeMPEGaudioHeader($FirstFrameAVDataOffset, $FirstFrameThisfileInfo, false)) {
1410                                                 // if this is the first valid MPEG-audio frame, save it in case it's a VBR header frame and there's
1411                                                 // garbage between this frame and a valid sequence of MPEG-audio frames, to be restored below
1412                                                 unset($FirstFrameThisfileInfo);
1413                                         }
1414                                 }
1415
1416                                 $dummy = $info; // only overwrite real data if valid header found
1417                                 if ($this->decodeMPEGaudioHeader($avdataoffset + $SynchSeekOffset, $dummy, true)) {
1418                                         $info = $dummy;
1419                                         $info['avdataoffset'] = $avdataoffset + $SynchSeekOffset;
1420                                         switch (isset($info['fileformat']) ? $info['fileformat'] : '') {
1421                                                 case '':
1422                                                 case 'id3':
1423                                                 case 'ape':
1424                                                 case 'mp3':
1425                                                         $info['fileformat']          = 'mp3';
1426                                                         $info['audio']['dataformat'] = 'mp3';
1427                                                         break;
1428                                         }
1429                                         if (isset($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode']) && ($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode'] == 'vbr')) {
1430                                                 if (!(abs($info['audio']['bitrate'] - $FirstFrameThisfileInfo['audio']['bitrate']) <= 1)) {
1431                                                         // If there is garbage data between a valid VBR header frame and a sequence
1432                                                         // of valid MPEG-audio frames the VBR data is no longer discarded.
1433                                                         $info = $FirstFrameThisfileInfo;
1434                                                         $info['avdataoffset']        = $FirstFrameAVDataOffset;
1435                                                         $info['fileformat']          = 'mp3';
1436                                                         $info['audio']['dataformat'] = 'mp3';
1437                                                         $dummy                       = $info;
1438                                                         unset($dummy['mpeg']['audio']);
1439                                                         $GarbageOffsetStart = $FirstFrameAVDataOffset + $FirstFrameThisfileInfo['mpeg']['audio']['framelength'];
1440                                                         $GarbageOffsetEnd   = $avdataoffset + $SynchSeekOffset;
1441                                                         if ($this->decodeMPEGaudioHeader($GarbageOffsetEnd, $dummy, true, true)) {
1442                                                                 $info = $dummy;
1443                                                                 $info['avdataoffset'] = $GarbageOffsetEnd;
1444                                                                 $info['warning'][] = 'apparently-valid VBR header not used because could not find '.GETID3_MP3_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.'), but did find valid CBR stream starting at '.$GarbageOffsetEnd;
1445                                                         } else {
1446                                                                 $info['warning'][] = 'using data from VBR header even though could not find '.GETID3_MP3_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.')';
1447                                                         }
1448                                                 }
1449                                         }
1450                                         if (isset($info['mpeg']['audio']['bitrate_mode']) && ($info['mpeg']['audio']['bitrate_mode'] == 'vbr') && !isset($info['mpeg']['audio']['VBR_method'])) {
1451                                                 // VBR file with no VBR header
1452                                                 $BitrateHistogram = true;
1453                                         }
1454
1455                                         if ($BitrateHistogram) {
1456
1457                                                 $info['mpeg']['audio']['stereo_distribution']  = array('stereo'=>0, 'joint stereo'=>0, 'dual channel'=>0, 'mono'=>0);
1458                                                 $info['mpeg']['audio']['version_distribution'] = array('1'=>0, '2'=>0, '2.5'=>0);
1459
1460                                                 if ($info['mpeg']['audio']['version'] == '1') {
1461                                                         if ($info['mpeg']['audio']['layer'] == 3) {
1462                                                                 $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 40000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 320000=>0);
1463                                                         } elseif ($info['mpeg']['audio']['layer'] == 2) {
1464                                                                 $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 320000=>0, 384000=>0);
1465                                                         } elseif ($info['mpeg']['audio']['layer'] == 1) {
1466                                                                 $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 64000=>0, 96000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 288000=>0, 320000=>0, 352000=>0, 384000=>0, 416000=>0, 448000=>0);
1467                                                         }
1468                                                 } elseif ($info['mpeg']['audio']['layer'] == 1) {
1469                                                         $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 144000=>0, 160000=>0, 176000=>0, 192000=>0, 224000=>0, 256000=>0);
1470                                                 } else {
1471                                                         $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 8000=>0, 16000=>0, 24000=>0, 32000=>0, 40000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 144000=>0, 160000=>0);
1472                                                 }
1473
1474                                                 $dummy = array('error'=>$info['error'], 'warning'=>$info['warning'], 'avdataend'=>$info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1475                                                 $synchstartoffset = $info['avdataoffset'];
1476                                                 fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
1477
1478                                                 // you can play with these numbers:
1479                                                 $max_frames_scan  = 50000;
1480                                                 $max_scan_segments = 10;
1481
1482                                                 // don't play with these numbers:
1483                                                 $FastMode = false;
1484                                                 $SynchErrorsFound = 0;
1485                                                 $frames_scanned   = 0;
1486                                                 $this_scan_segment = 0;
1487                                                 $frames_scan_per_segment = ceil($max_frames_scan / $max_scan_segments);
1488                                                 $pct_data_scanned = 0;
1489                                                 for ($current_segment = 0; $current_segment < $max_scan_segments; $current_segment++) {
1490                                                         $frames_scanned_this_segment = 0;
1491                                                         if (ftell($this->getid3->fp) >= $info['avdataend']) {
1492                                                                 break;
1493                                                         }
1494                                                         $scan_start_offset[$current_segment] = max(ftell($this->getid3->fp), $info['avdataoffset'] + round($current_segment * (($info['avdataend'] - $info['avdataoffset']) / $max_scan_segments)));
1495                                                         if ($current_segment > 0) {
1496                                                                 fseek($this->getid3->fp, $scan_start_offset[$current_segment], SEEK_SET);
1497                                                                 $buffer_4k = fread($this->getid3->fp, 4096);
1498                                                                 for ($j = 0; $j < (strlen($buffer_4k) - 4); $j++) {
1499                                                                         if (($buffer_4k{$j} == "\xFF") && ($buffer_4k{($j + 1)} > "\xE0")) { // synch detected
1500                                                                                 if ($this->decodeMPEGaudioHeader($scan_start_offset[$current_segment] + $j, $dummy, false, false, $FastMode)) {
1501                                                                                         $calculated_next_offset = $scan_start_offset[$current_segment] + $j + $dummy['mpeg']['audio']['framelength'];
1502                                                                                         if ($this->decodeMPEGaudioHeader($calculated_next_offset, $dummy, false, false, $FastMode)) {
1503                                                                                                 $scan_start_offset[$current_segment] += $j;
1504                                                                                                 break;
1505                                                                                         }
1506                                                                                 }
1507                                                                         }
1508                                                                 }
1509                                                         }
1510                                                         $synchstartoffset = $scan_start_offset[$current_segment];
1511                                                         while ($this->decodeMPEGaudioHeader($synchstartoffset, $dummy, false, false, $FastMode)) {
1512                                                                 $FastMode = true;
1513                                                                 $thisframebitrate = $MPEGaudioBitrateLookup[$MPEGaudioVersionLookup[$dummy['mpeg']['audio']['raw']['version']]][$MPEGaudioLayerLookup[$dummy['mpeg']['audio']['raw']['layer']]][$dummy['mpeg']['audio']['raw']['bitrate']];
1514
1515                                                                 if (empty($dummy['mpeg']['audio']['framelength'])) {
1516                                                                         $SynchErrorsFound++;
1517                                                                         $synchstartoffset++;
1518                                                                 } else {
1519                                                                         getid3_lib::safe_inc($info['mpeg']['audio']['bitrate_distribution'][$thisframebitrate]);
1520                                                                         getid3_lib::safe_inc($info['mpeg']['audio']['stereo_distribution'][$dummy['mpeg']['audio']['channelmode']]);
1521                                                                         getid3_lib::safe_inc($info['mpeg']['audio']['version_distribution'][$dummy['mpeg']['audio']['version']]);
1522                                                                         $synchstartoffset += $dummy['mpeg']['audio']['framelength'];
1523                                                                 }
1524                                                                 $frames_scanned++;
1525                                                                 if ($frames_scan_per_segment && (++$frames_scanned_this_segment >= $frames_scan_per_segment)) {
1526                                                                         $this_pct_scanned = (ftell($this->getid3->fp) - $scan_start_offset[$current_segment]) / ($info['avdataend'] - $info['avdataoffset']);
1527                                                                         if (($current_segment == 0) && (($this_pct_scanned * $max_scan_segments) >= 1)) {
1528                                                                                 // file likely contains < $max_frames_scan, just scan as one segment
1529                                                                                 $max_scan_segments = 1;
1530                                                                                 $frames_scan_per_segment = $max_frames_scan;
1531                                                                         } else {
1532                                                                                 $pct_data_scanned += $this_pct_scanned;
1533                                                                                 break;
1534                                                                         }
1535                                                                 }
1536                                                         }
1537                                                 }
1538                                                 if ($pct_data_scanned > 0) {
1539                                                         $info['warning'][] = 'too many MPEG audio frames to scan, only scanned '.$frames_scanned.' frames in '.$max_scan_segments.' segments ('.number_format($pct_data_scanned * 100, 1).'% of file) and extrapolated distribution, playtime and bitrate may be incorrect.';
1540                                                         foreach ($info['mpeg']['audio'] as $key1 => $value1) {
1541                                                                 if (!preg_match('#_distribution$#i', $key1)) {
1542                                                                         continue;
1543                                                                 }
1544                                                                 foreach ($value1 as $key2 => $value2) {
1545                                                                         $info['mpeg']['audio'][$key1][$key2] = round($value2 / $pct_data_scanned);
1546                                                                 }
1547                                                         }
1548                                                 }
1549
1550                                                 if ($SynchErrorsFound > 0) {
1551                                                         $info['warning'][] = 'Found '.$SynchErrorsFound.' synch errors in histogram analysis';
1552                                                         //return false;
1553                                                 }
1554
1555                                                 $bittotal     = 0;
1556                                                 $framecounter = 0;
1557                                                 foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitratevalue => $bitratecount) {
1558                                                         $framecounter += $bitratecount;
1559                                                         if ($bitratevalue != 'free') {
1560                                                                 $bittotal += ($bitratevalue * $bitratecount);
1561                                                         }
1562                                                 }
1563                                                 if ($framecounter == 0) {
1564                                                         $info['error'][] = 'Corrupt MP3 file: framecounter == zero';
1565                                                         return false;
1566                                                 }
1567                                                 $info['mpeg']['audio']['frame_count'] = getid3_lib::CastAsInt($framecounter);
1568                                                 $info['mpeg']['audio']['bitrate']     = ($bittotal / $framecounter);
1569
1570                                                 $info['audio']['bitrate'] = $info['mpeg']['audio']['bitrate'];
1571
1572
1573                                                 // Definitively set VBR vs CBR, even if the Xing/LAME/VBRI header says differently
1574                                                 $distinct_bitrates = 0;
1575                                                 foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitrate_value => $bitrate_count) {
1576                                                         if ($bitrate_count > 0) {
1577                                                                 $distinct_bitrates++;
1578                                                         }
1579                                                 }
1580                                                 if ($distinct_bitrates > 1) {
1581                                                         $info['mpeg']['audio']['bitrate_mode'] = 'vbr';
1582                                                 } else {
1583                                                         $info['mpeg']['audio']['bitrate_mode'] = 'cbr';
1584                                                 }
1585                                                 $info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
1586
1587                                         }
1588
1589                                         break; // exit while()
1590                                 }
1591                         }
1592
1593                         $SynchSeekOffset++;
1594                         if (($avdataoffset + $SynchSeekOffset) >= $info['avdataend']) {
1595                                 // end of file/data
1596
1597                                 if (empty($info['mpeg']['audio'])) {
1598
1599                                         $info['error'][] = 'could not find valid MPEG synch before end of file';
1600                                         if (isset($info['audio']['bitrate'])) {
1601                                                 unset($info['audio']['bitrate']);
1602                                         }
1603                                         if (isset($info['mpeg']['audio'])) {
1604                                                 unset($info['mpeg']['audio']);
1605                                         }
1606                                         if (isset($info['mpeg']) && (!is_array($info['mpeg']) || empty($info['mpeg']))) {
1607                                                 unset($info['mpeg']);
1608                                         }
1609                                         return false;
1610
1611                                 }
1612                                 break;
1613                         }
1614
1615                 }
1616                 $info['audio']['channels']        = $info['mpeg']['audio']['channels'];
1617                 $info['audio']['channelmode']     = $info['mpeg']['audio']['channelmode'];
1618                 $info['audio']['sample_rate']     = $info['mpeg']['audio']['sample_rate'];
1619                 return true;
1620         }
1621
1622
1623         public static function MPEGaudioVersionArray() {
1624                 static $MPEGaudioVersion = array('2.5', false, '2', '1');
1625                 return $MPEGaudioVersion;
1626         }
1627
1628         public static function MPEGaudioLayerArray() {
1629                 static $MPEGaudioLayer = array(false, 3, 2, 1);
1630                 return $MPEGaudioLayer;
1631         }
1632
1633         public static function MPEGaudioBitrateArray() {
1634                 static $MPEGaudioBitrate;
1635                 if (empty($MPEGaudioBitrate)) {
1636                         $MPEGaudioBitrate = array (
1637                                 '1'  =>  array (1 => array('free', 32000, 64000, 96000, 128000, 160000, 192000, 224000, 256000, 288000, 320000, 352000, 384000, 416000, 448000),
1638                                                                 2 => array('free', 32000, 48000, 56000,  64000,  80000,  96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000, 384000),
1639                                                                 3 => array('free', 32000, 40000, 48000,  56000,  64000,  80000,  96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000)
1640                                                            ),
1641
1642                                 '2'  =>  array (1 => array('free', 32000, 48000, 56000,  64000,  80000,  96000, 112000, 128000, 144000, 160000, 176000, 192000, 224000, 256000),
1643                                                                 2 => array('free',  8000, 16000, 24000,  32000,  40000,  48000,  56000,  64000,  80000,  96000, 112000, 128000, 144000, 160000),
1644                                                            )
1645                         );
1646                         $MPEGaudioBitrate['2'][3] = $MPEGaudioBitrate['2'][2];
1647                         $MPEGaudioBitrate['2.5']  = $MPEGaudioBitrate['2'];
1648                 }
1649                 return $MPEGaudioBitrate;
1650         }
1651
1652         public static function MPEGaudioFrequencyArray() {
1653                 static $MPEGaudioFrequency;
1654                 if (empty($MPEGaudioFrequency)) {
1655                         $MPEGaudioFrequency = array (
1656                                 '1'   => array(44100, 48000, 32000),
1657                                 '2'   => array(22050, 24000, 16000),
1658                                 '2.5' => array(11025, 12000,  8000)
1659                         );
1660                 }
1661                 return $MPEGaudioFrequency;
1662         }
1663
1664         public static function MPEGaudioChannelModeArray() {
1665                 static $MPEGaudioChannelMode = array('stereo', 'joint stereo', 'dual channel', 'mono');
1666                 return $MPEGaudioChannelMode;
1667         }
1668
1669         public static function MPEGaudioModeExtensionArray() {
1670                 static $MPEGaudioModeExtension;
1671                 if (empty($MPEGaudioModeExtension)) {
1672                         $MPEGaudioModeExtension = array (
1673                                 1 => array('4-31', '8-31', '12-31', '16-31'),
1674                                 2 => array('4-31', '8-31', '12-31', '16-31'),
1675                                 3 => array('', 'IS', 'MS', 'IS+MS')
1676                         );
1677                 }
1678                 return $MPEGaudioModeExtension;
1679         }
1680
1681         public static function MPEGaudioEmphasisArray() {
1682                 static $MPEGaudioEmphasis = array('none', '50/15ms', false, 'CCIT J.17');
1683                 return $MPEGaudioEmphasis;
1684         }
1685
1686         public static function MPEGaudioHeaderBytesValid($head4, $allowBitrate15=false) {
1687                 return self::MPEGaudioHeaderValid(self::MPEGaudioHeaderDecode($head4), false, $allowBitrate15);
1688         }
1689
1690         public static function MPEGaudioHeaderValid($rawarray, $echoerrors=false, $allowBitrate15=false) {
1691                 if (($rawarray['synch'] & 0x0FFE) != 0x0FFE) {
1692                         return false;
1693                 }
1694
1695                 static $MPEGaudioVersionLookup;
1696                 static $MPEGaudioLayerLookup;
1697                 static $MPEGaudioBitrateLookup;
1698                 static $MPEGaudioFrequencyLookup;
1699                 static $MPEGaudioChannelModeLookup;
1700                 static $MPEGaudioModeExtensionLookup;
1701                 static $MPEGaudioEmphasisLookup;
1702                 if (empty($MPEGaudioVersionLookup)) {
1703                         $MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();
1704                         $MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();
1705                         $MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();
1706                         $MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();
1707                         $MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();
1708                         $MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
1709                         $MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();
1710                 }
1711
1712                 if (isset($MPEGaudioVersionLookup[$rawarray['version']])) {
1713                         $decodedVersion = $MPEGaudioVersionLookup[$rawarray['version']];
1714                 } else {
1715                         echo ($echoerrors ? "\n".'invalid Version ('.$rawarray['version'].')' : '');
1716                         return false;
1717                 }
1718                 if (isset($MPEGaudioLayerLookup[$rawarray['layer']])) {
1719                         $decodedLayer = $MPEGaudioLayerLookup[$rawarray['layer']];
1720                 } else {
1721                         echo ($echoerrors ? "\n".'invalid Layer ('.$rawarray['layer'].')' : '');
1722                         return false;
1723                 }
1724                 if (!isset($MPEGaudioBitrateLookup[$decodedVersion][$decodedLayer][$rawarray['bitrate']])) {
1725                         echo ($echoerrors ? "\n".'invalid Bitrate ('.$rawarray['bitrate'].')' : '');
1726                         if ($rawarray['bitrate'] == 15) {
1727                                 // known issue in LAME 3.90 - 3.93.1 where free-format has bitrate ID of 15 instead of 0
1728                                 // let it go through here otherwise file will not be identified
1729                                 if (!$allowBitrate15) {
1730                                         return false;
1731                                 }
1732                         } else {
1733                                 return false;
1734                         }
1735                 }
1736                 if (!isset($MPEGaudioFrequencyLookup[$decodedVersion][$rawarray['sample_rate']])) {
1737                         echo ($echoerrors ? "\n".'invalid Frequency ('.$rawarray['sample_rate'].')' : '');
1738                         return false;
1739                 }
1740                 if (!isset($MPEGaudioChannelModeLookup[$rawarray['channelmode']])) {
1741                         echo ($echoerrors ? "\n".'invalid ChannelMode ('.$rawarray['channelmode'].')' : '');
1742                         return false;
1743                 }
1744                 if (!isset($MPEGaudioModeExtensionLookup[$decodedLayer][$rawarray['modeextension']])) {
1745                         echo ($echoerrors ? "\n".'invalid Mode Extension ('.$rawarray['modeextension'].')' : '');
1746                         return false;
1747                 }
1748                 if (!isset($MPEGaudioEmphasisLookup[$rawarray['emphasis']])) {
1749                         echo ($echoerrors ? "\n".'invalid Emphasis ('.$rawarray['emphasis'].')' : '');
1750                         return false;
1751                 }
1752                 // These are just either set or not set, you can't mess that up :)
1753                 // $rawarray['protection'];
1754                 // $rawarray['padding'];
1755                 // $rawarray['private'];
1756                 // $rawarray['copyright'];
1757                 // $rawarray['original'];
1758
1759                 return true;
1760         }
1761
1762         public static function MPEGaudioHeaderDecode($Header4Bytes) {
1763                 // AAAA AAAA  AAAB BCCD  EEEE FFGH  IIJJ KLMM
1764                 // A - Frame sync (all bits set)
1765                 // B - MPEG Audio version ID
1766                 // C - Layer description
1767                 // D - Protection bit
1768                 // E - Bitrate index
1769                 // F - Sampling rate frequency index
1770                 // G - Padding bit
1771                 // H - Private bit
1772                 // I - Channel Mode
1773                 // J - Mode extension (Only if Joint stereo)
1774                 // K - Copyright
1775                 // L - Original
1776                 // M - Emphasis
1777
1778                 if (strlen($Header4Bytes) != 4) {
1779                         return false;
1780                 }
1781
1782                 $MPEGrawHeader['synch']         = (getid3_lib::BigEndian2Int(substr($Header4Bytes, 0, 2)) & 0xFFE0) >> 4;
1783                 $MPEGrawHeader['version']       = (ord($Header4Bytes{1}) & 0x18) >> 3; //    BB
1784                 $MPEGrawHeader['layer']         = (ord($Header4Bytes{1}) & 0x06) >> 1; //      CC
1785                 $MPEGrawHeader['protection']    = (ord($Header4Bytes{1}) & 0x01);      //        D
1786                 $MPEGrawHeader['bitrate']       = (ord($Header4Bytes{2}) & 0xF0) >> 4; // EEEE
1787                 $MPEGrawHeader['sample_rate']   = (ord($Header4Bytes{2}) & 0x0C) >> 2; //     FF
1788                 $MPEGrawHeader['padding']       = (ord($Header4Bytes{2}) & 0x02) >> 1; //       G
1789                 $MPEGrawHeader['private']       = (ord($Header4Bytes{2}) & 0x01);      //        H
1790                 $MPEGrawHeader['channelmode']   = (ord($Header4Bytes{3}) & 0xC0) >> 6; // II
1791                 $MPEGrawHeader['modeextension'] = (ord($Header4Bytes{3}) & 0x30) >> 4; //   JJ
1792                 $MPEGrawHeader['copyright']     = (ord($Header4Bytes{3}) & 0x08) >> 3; //     K
1793                 $MPEGrawHeader['original']      = (ord($Header4Bytes{3}) & 0x04) >> 2; //      L
1794                 $MPEGrawHeader['emphasis']      = (ord($Header4Bytes{3}) & 0x03);      //       MM
1795
1796                 return $MPEGrawHeader;
1797         }
1798
1799         public static function MPEGaudioFrameLength(&$bitrate, &$version, &$layer, $padding, &$samplerate) {
1800                 static $AudioFrameLengthCache = array();
1801
1802                 if (!isset($AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate])) {
1803                         $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = false;
1804                         if ($bitrate != 'free') {
1805
1806                                 if ($version == '1') {
1807
1808                                         if ($layer == '1') {
1809
1810                                                 // For Layer I slot is 32 bits long
1811                                                 $FrameLengthCoefficient = 48;
1812                                                 $SlotLength = 4;
1813
1814                                         } else { // Layer 2 / 3
1815
1816                                                 // for Layer 2 and Layer 3 slot is 8 bits long.
1817                                                 $FrameLengthCoefficient = 144;
1818                                                 $SlotLength = 1;
1819
1820                                         }
1821
1822                                 } else { // MPEG-2 / MPEG-2.5
1823
1824                                         if ($layer == '1') {
1825
1826                                                 // For Layer I slot is 32 bits long
1827                                                 $FrameLengthCoefficient = 24;
1828                                                 $SlotLength = 4;
1829
1830                                         } elseif ($layer == '2') {
1831
1832                                                 // for Layer 2 and Layer 3 slot is 8 bits long.
1833                                                 $FrameLengthCoefficient = 144;
1834                                                 $SlotLength = 1;
1835
1836                                         } else { // layer 3
1837
1838                                                 // for Layer 2 and Layer 3 slot is 8 bits long.
1839                                                 $FrameLengthCoefficient = 72;
1840                                                 $SlotLength = 1;
1841
1842                                         }
1843
1844                                 }
1845
1846                                 // FrameLengthInBytes = ((Coefficient * BitRate) / SampleRate) + Padding
1847                                 if ($samplerate > 0) {
1848                                         $NewFramelength  = ($FrameLengthCoefficient * $bitrate) / $samplerate;
1849                                         $NewFramelength  = floor($NewFramelength / $SlotLength) * $SlotLength; // round to next-lower multiple of SlotLength (1 byte for Layer 2/3, 4 bytes for Layer I)
1850                                         if ($padding) {
1851                                                 $NewFramelength += $SlotLength;
1852                                         }
1853                                         $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = (int) $NewFramelength;
1854                                 }
1855                         }
1856                 }
1857                 return $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate];
1858         }
1859
1860         public static function ClosestStandardMP3Bitrate($bit_rate) {
1861                 static $standard_bit_rates = array (320000, 256000, 224000, 192000, 160000, 128000, 112000, 96000, 80000, 64000, 56000, 48000, 40000, 32000, 24000, 16000, 8000);
1862                 static $bit_rate_table = array (0=>'-');
1863                 $round_bit_rate = intval(round($bit_rate, -3));
1864                 if (!isset($bit_rate_table[$round_bit_rate])) {
1865                         if ($round_bit_rate > max($standard_bit_rates)) {
1866                                 $bit_rate_table[$round_bit_rate] = round($bit_rate, 2 - strlen($bit_rate));
1867                         } else {
1868                                 $bit_rate_table[$round_bit_rate] = max($standard_bit_rates);
1869                                 foreach ($standard_bit_rates as $standard_bit_rate) {
1870                                         if ($round_bit_rate >= $standard_bit_rate + (($bit_rate_table[$round_bit_rate] - $standard_bit_rate) / 2)) {
1871                                                 break;
1872                                         }
1873                                         $bit_rate_table[$round_bit_rate] = $standard_bit_rate;
1874                                 }
1875                         }
1876                 }
1877                 return $bit_rate_table[$round_bit_rate];
1878         }
1879
1880         public static function XingVBRidOffset($version, $channelmode) {
1881                 static $XingVBRidOffsetCache = array();
1882                 if (empty($XingVBRidOffset)) {
1883                         $XingVBRidOffset = array (
1884                                 '1'   => array ('mono'          => 0x15, // 4 + 17 = 21
1885                                                                 'stereo'        => 0x24, // 4 + 32 = 36
1886                                                                 'joint stereo'  => 0x24,
1887                                                                 'dual channel'  => 0x24
1888                                                            ),
1889
1890                                 '2'   => array ('mono'          => 0x0D, // 4 +  9 = 13
1891                                                                 'stereo'        => 0x15, // 4 + 17 = 21
1892                                                                 'joint stereo'  => 0x15,
1893                                                                 'dual channel'  => 0x15
1894                                                            ),
1895
1896                                 '2.5' => array ('mono'          => 0x15,
1897                                                                 'stereo'        => 0x15,
1898                                                                 'joint stereo'  => 0x15,
1899                                                                 'dual channel'  => 0x15
1900                                                            )
1901                         );
1902                 }
1903                 return $XingVBRidOffset[$version][$channelmode];
1904         }
1905
1906         public static function LAMEvbrMethodLookup($VBRmethodID) {
1907                 static $LAMEvbrMethodLookup = array(
1908                         0x00 => 'unknown',
1909                         0x01 => 'cbr',
1910                         0x02 => 'abr',
1911                         0x03 => 'vbr-old / vbr-rh',
1912                         0x04 => 'vbr-new / vbr-mtrh',
1913                         0x05 => 'vbr-mt',
1914                         0x06 => 'vbr (full vbr method 4)',
1915                         0x08 => 'cbr (constant bitrate 2 pass)',
1916                         0x09 => 'abr (2 pass)',
1917                         0x0F => 'reserved'
1918                 );
1919                 return (isset($LAMEvbrMethodLookup[$VBRmethodID]) ? $LAMEvbrMethodLookup[$VBRmethodID] : '');
1920         }
1921
1922         public static function LAMEmiscStereoModeLookup($StereoModeID) {
1923                 static $LAMEmiscStereoModeLookup = array(
1924                         0 => 'mono',
1925                         1 => 'stereo',
1926                         2 => 'dual mono',
1927                         3 => 'joint stereo',
1928                         4 => 'forced stereo',
1929                         5 => 'auto',
1930                         6 => 'intensity stereo',
1931                         7 => 'other'
1932                 );
1933                 return (isset($LAMEmiscStereoModeLookup[$StereoModeID]) ? $LAMEmiscStereoModeLookup[$StereoModeID] : '');
1934         }
1935
1936         public static function LAMEmiscSourceSampleFrequencyLookup($SourceSampleFrequencyID) {
1937                 static $LAMEmiscSourceSampleFrequencyLookup = array(
1938                         0 => '<= 32 kHz',
1939                         1 => '44.1 kHz',
1940                         2 => '48 kHz',
1941                         3 => '> 48kHz'
1942                 );
1943                 return (isset($LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID]) ? $LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID] : '');
1944         }
1945
1946         public static function LAMEsurroundInfoLookup($SurroundInfoID) {
1947                 static $LAMEsurroundInfoLookup = array(
1948                         0 => 'no surround info',
1949                         1 => 'DPL encoding',
1950                         2 => 'DPL2 encoding',
1951                         3 => 'Ambisonic encoding'
1952                 );
1953                 return (isset($LAMEsurroundInfoLookup[$SurroundInfoID]) ? $LAMEsurroundInfoLookup[$SurroundInfoID] : 'reserved');
1954         }
1955
1956         public static function LAMEpresetUsedLookup($LAMEtag) {
1957
1958                 if ($LAMEtag['preset_used_id'] == 0) {
1959                         // no preset used (LAME >=3.93)
1960                         // no preset recorded (LAME <3.93)
1961                         return '';
1962                 }
1963                 $LAMEpresetUsedLookup = array();
1964
1965                 /////  THIS PART CANNOT BE STATIC .
1966                 for ($i = 8; $i <= 320; $i++) {
1967                         switch ($LAMEtag['vbr_method']) {
1968                                 case 'cbr':
1969                                         $LAMEpresetUsedLookup[$i] = '--alt-preset '.$LAMEtag['vbr_method'].' '.$i;
1970                                         break;
1971                                 case 'abr':
1972                                 default: // other VBR modes shouldn't be here(?)
1973                                         $LAMEpresetUsedLookup[$i] = '--alt-preset '.$i;
1974                                         break;
1975                         }
1976                 }
1977
1978                 // named old-style presets (studio, phone, voice, etc) are handled in GuessEncoderOptions()
1979
1980                 // named alt-presets
1981                 $LAMEpresetUsedLookup[1000] = '--r3mix';
1982                 $LAMEpresetUsedLookup[1001] = '--alt-preset standard';
1983                 $LAMEpresetUsedLookup[1002] = '--alt-preset extreme';
1984                 $LAMEpresetUsedLookup[1003] = '--alt-preset insane';
1985                 $LAMEpresetUsedLookup[1004] = '--alt-preset fast standard';
1986                 $LAMEpresetUsedLookup[1005] = '--alt-preset fast extreme';
1987                 $LAMEpresetUsedLookup[1006] = '--alt-preset medium';
1988                 $LAMEpresetUsedLookup[1007] = '--alt-preset fast medium';
1989
1990                 // LAME 3.94 additions/changes
1991                 $LAMEpresetUsedLookup[1010] = '--preset portable';                                                           // 3.94a15 Oct 21 2003
1992                 $LAMEpresetUsedLookup[1015] = '--preset radio';                                                              // 3.94a15 Oct 21 2003
1993
1994                 $LAMEpresetUsedLookup[320]  = '--preset insane';                                                             // 3.94a15 Nov 12 2003
1995                 $LAMEpresetUsedLookup[410]  = '-V9';
1996                 $LAMEpresetUsedLookup[420]  = '-V8';
1997                 $LAMEpresetUsedLookup[440]  = '-V6';
1998                 $LAMEpresetUsedLookup[430]  = '--preset radio';                                                              // 3.94a15 Nov 12 2003
1999                 $LAMEpresetUsedLookup[450]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'portable';  // 3.94a15 Nov 12 2003
2000                 $LAMEpresetUsedLookup[460]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'medium';    // 3.94a15 Nov 12 2003
2001                 $LAMEpresetUsedLookup[470]  = '--r3mix';                                                                     // 3.94b1  Dec 18 2003
2002                 $LAMEpresetUsedLookup[480]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'standard';  // 3.94a15 Nov 12 2003
2003                 $LAMEpresetUsedLookup[490]  = '-V1';
2004                 $LAMEpresetUsedLookup[500]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'extreme';   // 3.94a15 Nov 12 2003
2005
2006                 return (isset($LAMEpresetUsedLookup[$LAMEtag['preset_used_id']]) ? $LAMEpresetUsedLookup[$LAMEtag['preset_used_id']] : 'new/unknown preset: '.$LAMEtag['preset_used_id'].' - report to info@getid3.org');
2007         }
2008
2009 }