WordPress 4.3
[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 //          also https://github.com/JamesHeinrich/getID3       //
7 /////////////////////////////////////////////////////////////////
8 // See readme.txt for more details                             //
9 /////////////////////////////////////////////////////////////////
10 //                                                             //
11 // module.audio.mp3.php                                        //
12 // module for analyzing MP3 files                              //
13 // dependencies: NONE                                          //
14 //                                                            ///
15 /////////////////////////////////////////////////////////////////
16
17
18 // number of frames to scan to determine if MPEG-audio sequence is valid
19 // Lower this number to 5-20 for faster scanning
20 // Increase this number to 50+ for most accurate detection of valid VBR/CBR
21 // mpeg-audio streams
22 define('GETID3_MP3_VALID_CHECK_FRAMES', 35);
23
24
25 class getid3_mp3 extends getid3_handler
26 {
27
28         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
29
30         public function Analyze() {
31                 $info = &$this->getid3->info;
32
33                 $initialOffset = $info['avdataoffset'];
34
35                 if (!$this->getOnlyMPEGaudioInfo($info['avdataoffset'])) {
36                         if ($this->allow_bruteforce) {
37                                 $info['error'][] = 'Rescanning file in BruteForce mode';
38                                 $this->getOnlyMPEGaudioInfoBruteForce($this->getid3->fp, $info);
39                         }
40                 }
41
42
43                 if (isset($info['mpeg']['audio']['bitrate_mode'])) {
44                         $info['audio']['bitrate_mode'] = strtolower($info['mpeg']['audio']['bitrate_mode']);
45                 }
46
47                 if (((isset($info['id3v2']['headerlength']) && ($info['avdataoffset'] > $info['id3v2']['headerlength'])) || (!isset($info['id3v2']) && ($info['avdataoffset'] > 0) && ($info['avdataoffset'] != $initialOffset)))) {
48
49                         $synchoffsetwarning = 'Unknown data before synch ';
50                         if (isset($info['id3v2']['headerlength'])) {
51                                 $synchoffsetwarning .= '(ID3v2 header ends at '.$info['id3v2']['headerlength'].', then '.($info['avdataoffset'] - $info['id3v2']['headerlength']).' bytes garbage, ';
52                         } elseif ($initialOffset > 0) {
53                                 $synchoffsetwarning .= '(should be at '.$initialOffset.', ';
54                         } else {
55                                 $synchoffsetwarning .= '(should be at beginning of file, ';
56                         }
57                         $synchoffsetwarning .= 'synch detected at '.$info['avdataoffset'].')';
58                         if (isset($info['audio']['bitrate_mode']) && ($info['audio']['bitrate_mode'] == 'cbr')) {
59
60                                 if (!empty($info['id3v2']['headerlength']) && (($info['avdataoffset'] - $info['id3v2']['headerlength']) == $info['mpeg']['audio']['framelength'])) {
61
62                                         $synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90-3.92) DLL in CBR mode.';
63                                         $info['audio']['codec'] = 'LAME';
64                                         $CurrentDataLAMEversionString = 'LAME3.';
65
66                                 } elseif (empty($info['id3v2']['headerlength']) && ($info['avdataoffset'] == $info['mpeg']['audio']['framelength'])) {
67
68                                         $synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90 - 3.92) DLL in CBR mode.';
69                                         $info['audio']['codec'] = 'LAME';
70                                         $CurrentDataLAMEversionString = 'LAME3.';
71
72                                 }
73
74                         }
75                         $info['warning'][] = $synchoffsetwarning;
76
77                 }
78
79                 if (isset($info['mpeg']['audio']['LAME'])) {
80                         $info['audio']['codec'] = 'LAME';
81                         if (!empty($info['mpeg']['audio']['LAME']['long_version'])) {
82                                 $info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['long_version'], "\x00");
83                         } elseif (!empty($info['mpeg']['audio']['LAME']['short_version'])) {
84                                 $info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['short_version'], "\x00");
85                         }
86                 }
87
88                 $CurrentDataLAMEversionString = (!empty($CurrentDataLAMEversionString) ? $CurrentDataLAMEversionString : (isset($info['audio']['encoder']) ? $info['audio']['encoder'] : ''));
89                 if (!empty($CurrentDataLAMEversionString) && (substr($CurrentDataLAMEversionString, 0, 6) == 'LAME3.') && !preg_match('[0-9\)]', substr($CurrentDataLAMEversionString, -1))) {
90                         // a version number of LAME that does not end with a number like "LAME3.92"
91                         // or with a closing parenthesis like "LAME3.88 (alpha)"
92                         // or a version of LAME with the LAMEtag-not-filled-in-DLL-mode bug (3.90-3.92)
93
94                         // not sure what the actual last frame length will be, but will be less than or equal to 1441
95                         $PossiblyLongerLAMEversion_FrameLength = 1441;
96
97                         // Not sure what version of LAME this is - look in padding of last frame for longer version string
98                         $PossibleLAMEversionStringOffset = $info['avdataend'] - $PossiblyLongerLAMEversion_FrameLength;
99                         $this->fseek($PossibleLAMEversionStringOffset);
100                         $PossiblyLongerLAMEversion_Data = $this->fread($PossiblyLongerLAMEversion_FrameLength);
101                         switch (substr($CurrentDataLAMEversionString, -1)) {
102                                 case 'a':
103                                 case 'b':
104                                         // "LAME3.94a" will have a longer version string of "LAME3.94 (alpha)" for example
105                                         // need to trim off "a" to match longer string
106                                         $CurrentDataLAMEversionString = substr($CurrentDataLAMEversionString, 0, -1);
107                                         break;
108                         }
109                         if (($PossiblyLongerLAMEversion_String = strstr($PossiblyLongerLAMEversion_Data, $CurrentDataLAMEversionString)) !== false) {
110                                 if (substr($PossiblyLongerLAMEversion_String, 0, strlen($CurrentDataLAMEversionString)) == $CurrentDataLAMEversionString) {
111                                         $PossiblyLongerLAMEversion_NewString = substr($PossiblyLongerLAMEversion_String, 0, strspn($PossiblyLongerLAMEversion_String, 'LAME0123456789., (abcdefghijklmnopqrstuvwxyzJFSOND)')); //"LAME3.90.3"  "LAME3.87 (beta 1, Sep 27 2000)" "LAME3.88 (beta)"
112                                         if (empty($info['audio']['encoder']) || (strlen($PossiblyLongerLAMEversion_NewString) > strlen($info['audio']['encoder']))) {
113                                                 $info['audio']['encoder'] = $PossiblyLongerLAMEversion_NewString;
114                                         }
115                                 }
116                         }
117                 }
118                 if (!empty($info['audio']['encoder'])) {
119                         $info['audio']['encoder'] = rtrim($info['audio']['encoder'], "\x00 ");
120                 }
121
122                 switch (isset($info['mpeg']['audio']['layer']) ? $info['mpeg']['audio']['layer'] : '') {
123                         case 1:
124                         case 2:
125                                 $info['audio']['dataformat'] = 'mp'.$info['mpeg']['audio']['layer'];
126                                 break;
127                 }
128                 if (isset($info['fileformat']) && ($info['fileformat'] == 'mp3')) {
129                         switch ($info['audio']['dataformat']) {
130                                 case 'mp1':
131                                 case 'mp2':
132                                 case 'mp3':
133                                         $info['fileformat'] = $info['audio']['dataformat'];
134                                         break;
135
136                                 default:
137                                         $info['warning'][] = 'Expecting [audio][dataformat] to be mp1/mp2/mp3 when fileformat == mp3, [audio][dataformat] actually "'.$info['audio']['dataformat'].'"';
138                                         break;
139                         }
140                 }
141
142                 if (empty($info['fileformat'])) {
143                         unset($info['fileformat']);
144                         unset($info['audio']['bitrate_mode']);
145                         unset($info['avdataoffset']);
146                         unset($info['avdataend']);
147                         return false;
148                 }
149
150                 $info['mime_type']         = 'audio/mpeg';
151                 $info['audio']['lossless'] = false;
152
153                 // Calculate playtime
154                 if (!isset($info['playtime_seconds']) && isset($info['audio']['bitrate']) && ($info['audio']['bitrate'] > 0)) {
155                         $info['playtime_seconds'] = ($info['avdataend'] - $info['avdataoffset']) * 8 / $info['audio']['bitrate'];
156                 }
157
158                 $info['audio']['encoder_options'] = $this->GuessEncoderOptions();
159
160                 return true;
161         }
162
163
164         public function GuessEncoderOptions() {
165                 // shortcuts
166                 $info = &$this->getid3->info;
167                 if (!empty($info['mpeg']['audio'])) {
168                         $thisfile_mpeg_audio = &$info['mpeg']['audio'];
169                         if (!empty($thisfile_mpeg_audio['LAME'])) {
170                                 $thisfile_mpeg_audio_lame = &$thisfile_mpeg_audio['LAME'];
171                         }
172                 }
173
174                 $encoder_options = '';
175                 static $NamedPresetBitrates = array(16, 24, 40, 56, 112, 128, 160, 192, 256);
176
177                 if (isset($thisfile_mpeg_audio['VBR_method']) && ($thisfile_mpeg_audio['VBR_method'] == 'Fraunhofer') && !empty($thisfile_mpeg_audio['VBR_quality'])) {
178
179                         $encoder_options = 'VBR q'.$thisfile_mpeg_audio['VBR_quality'];
180
181                 } elseif (!empty($thisfile_mpeg_audio_lame['preset_used']) && (!in_array($thisfile_mpeg_audio_lame['preset_used_id'], $NamedPresetBitrates))) {
182
183                         $encoder_options = $thisfile_mpeg_audio_lame['preset_used'];
184
185                 } elseif (!empty($thisfile_mpeg_audio_lame['vbr_quality'])) {
186
187                         static $KnownEncoderValues = array();
188                         if (empty($KnownEncoderValues)) {
189
190                                 //$KnownEncoderValues[abrbitrate_minbitrate][vbr_quality][raw_vbr_method][raw_noise_shaping][raw_stereo_mode][ath_type][lowpass_frequency] = 'preset name';
191                                 $KnownEncoderValues[0xFF][58][1][1][3][2][20500] = '--alt-preset insane';        // 3.90,   3.90.1, 3.92
192                                 $KnownEncoderValues[0xFF][58][1][1][3][2][20600] = '--alt-preset insane';        // 3.90.2, 3.90.3, 3.91
193                                 $KnownEncoderValues[0xFF][57][1][1][3][4][20500] = '--alt-preset insane';        // 3.94,   3.95
194                                 $KnownEncoderValues['**'][78][3][2][3][2][19500] = '--alt-preset extreme';       // 3.90,   3.90.1, 3.92
195                                 $KnownEncoderValues['**'][78][3][2][3][2][19600] = '--alt-preset extreme';       // 3.90.2, 3.91
196                                 $KnownEncoderValues['**'][78][3][1][3][2][19600] = '--alt-preset extreme';       // 3.90.3
197                                 $KnownEncoderValues['**'][78][4][2][3][2][19500] = '--alt-preset fast extreme';  // 3.90,   3.90.1, 3.92
198                                 $KnownEncoderValues['**'][78][4][2][3][2][19600] = '--alt-preset fast extreme';  // 3.90.2, 3.90.3, 3.91
199                                 $KnownEncoderValues['**'][78][3][2][3][4][19000] = '--alt-preset standard';      // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
200                                 $KnownEncoderValues['**'][78][3][1][3][4][19000] = '--alt-preset standard';      // 3.90.3
201                                 $KnownEncoderValues['**'][78][4][2][3][4][19000] = '--alt-preset fast standard'; // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
202                                 $KnownEncoderValues['**'][78][4][1][3][4][19000] = '--alt-preset fast standard'; // 3.90.3
203                                 $KnownEncoderValues['**'][88][4][1][3][3][19500] = '--r3mix';                    // 3.90,   3.90.1, 3.92
204                                 $KnownEncoderValues['**'][88][4][1][3][3][19600] = '--r3mix';                    // 3.90.2, 3.90.3, 3.91
205                                 $KnownEncoderValues['**'][67][4][1][3][4][18000] = '--r3mix';                    // 3.94,   3.95
206                                 $KnownEncoderValues['**'][68][3][2][3][4][18000] = '--alt-preset medium';        // 3.90.3
207                                 $KnownEncoderValues['**'][68][4][2][3][4][18000] = '--alt-preset fast medium';   // 3.90.3
208
209                                 $KnownEncoderValues[0xFF][99][1][1][1][2][0]     = '--preset studio';            // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
210                                 $KnownEncoderValues[0xFF][58][2][1][3][2][20600] = '--preset studio';            // 3.90.3, 3.93.1
211                                 $KnownEncoderValues[0xFF][58][2][1][3][2][20500] = '--preset studio';            // 3.93
212                                 $KnownEncoderValues[0xFF][57][2][1][3][4][20500] = '--preset studio';            // 3.94,   3.95
213                                 $KnownEncoderValues[0xC0][88][1][1][1][2][0]     = '--preset cd';                // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
214                                 $KnownEncoderValues[0xC0][58][2][2][3][2][19600] = '--preset cd';                // 3.90.3, 3.93.1
215                                 $KnownEncoderValues[0xC0][58][2][2][3][2][19500] = '--preset cd';                // 3.93
216                                 $KnownEncoderValues[0xC0][57][2][1][3][4][19500] = '--preset cd';                // 3.94,   3.95
217                                 $KnownEncoderValues[0xA0][78][1][1][3][2][18000] = '--preset hifi';              // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
218                                 $KnownEncoderValues[0xA0][58][2][2][3][2][18000] = '--preset hifi';              // 3.90.3, 3.93,   3.93.1
219                                 $KnownEncoderValues[0xA0][57][2][1][3][4][18000] = '--preset hifi';              // 3.94,   3.95
220                                 $KnownEncoderValues[0x80][67][1][1][3][2][18000] = '--preset tape';              // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
221                                 $KnownEncoderValues[0x80][67][1][1][3][2][15000] = '--preset radio';             // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
222                                 $KnownEncoderValues[0x70][67][1][1][3][2][15000] = '--preset fm';                // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
223                                 $KnownEncoderValues[0x70][58][2][2][3][2][16000] = '--preset tape/radio/fm';     // 3.90.3, 3.93,   3.93.1
224                                 $KnownEncoderValues[0x70][57][2][1][3][4][16000] = '--preset tape/radio/fm';     // 3.94,   3.95
225                                 $KnownEncoderValues[0x38][58][2][2][0][2][10000] = '--preset voice';             // 3.90.3, 3.93,   3.93.1
226                                 $KnownEncoderValues[0x38][57][2][1][0][4][15000] = '--preset voice';             // 3.94,   3.95
227                                 $KnownEncoderValues[0x38][57][2][1][0][4][16000] = '--preset voice';             // 3.94a14
228                                 $KnownEncoderValues[0x28][65][1][1][0][2][7500]  = '--preset mw-us';             // 3.90,   3.90.1, 3.92
229                                 $KnownEncoderValues[0x28][65][1][1][0][2][7600]  = '--preset mw-us';             // 3.90.2, 3.91
230                                 $KnownEncoderValues[0x28][58][2][2][0][2][7000]  = '--preset mw-us';             // 3.90.3, 3.93,   3.93.1
231                                 $KnownEncoderValues[0x28][57][2][1][0][4][10500] = '--preset mw-us';             // 3.94,   3.95
232                                 $KnownEncoderValues[0x28][57][2][1][0][4][11200] = '--preset mw-us';             // 3.94a14
233                                 $KnownEncoderValues[0x28][57][2][1][0][4][8800]  = '--preset mw-us';             // 3.94a15
234                                 $KnownEncoderValues[0x18][58][2][2][0][2][4000]  = '--preset phon+/lw/mw-eu/sw'; // 3.90.3, 3.93.1
235                                 $KnownEncoderValues[0x18][58][2][2][0][2][3900]  = '--preset phon+/lw/mw-eu/sw'; // 3.93
236                                 $KnownEncoderValues[0x18][57][2][1][0][4][5900]  = '--preset phon+/lw/mw-eu/sw'; // 3.94,   3.95
237                                 $KnownEncoderValues[0x18][57][2][1][0][4][6200]  = '--preset phon+/lw/mw-eu/sw'; // 3.94a14
238                                 $KnownEncoderValues[0x18][57][2][1][0][4][3200]  = '--preset phon+/lw/mw-eu/sw'; // 3.94a15
239                                 $KnownEncoderValues[0x10][58][2][2][0][2][3800]  = '--preset phone';             // 3.90.3, 3.93.1
240                                 $KnownEncoderValues[0x10][58][2][2][0][2][3700]  = '--preset phone';             // 3.93
241                                 $KnownEncoderValues[0x10][57][2][1][0][4][5600]  = '--preset phone';             // 3.94,   3.95
242                         }
243
244                         if (isset($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']])) {
245
246                                 $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']];
247
248                         } 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']])) {
249
250                                 $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']][$thisfile_mpeg_audio_lame['lowpass_frequency']];
251
252                         } elseif ($info['audio']['bitrate_mode'] == 'vbr') {
253
254                                 // http://gabriel.mp3-tech.org/mp3infotag.html
255                                 // int    Quality = (100 - 10 * gfp->VBR_q - gfp->quality)h
256
257
258                                 $LAME_V_value = 10 - ceil($thisfile_mpeg_audio_lame['vbr_quality'] / 10);
259                                 $LAME_q_value = 100 - $thisfile_mpeg_audio_lame['vbr_quality'] - ($LAME_V_value * 10);
260                                 $encoder_options = '-V'.$LAME_V_value.' -q'.$LAME_q_value;
261
262                         } elseif ($info['audio']['bitrate_mode'] == 'cbr') {
263
264                                 $encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
265
266                         } else {
267
268                                 $encoder_options = strtoupper($info['audio']['bitrate_mode']);
269
270                         }
271
272                 } elseif (!empty($thisfile_mpeg_audio_lame['bitrate_abr'])) {
273
274                         $encoder_options = 'ABR'.$thisfile_mpeg_audio_lame['bitrate_abr'];
275
276                 } elseif (!empty($info['audio']['bitrate'])) {
277
278                         if ($info['audio']['bitrate_mode'] == 'cbr') {
279                                 $encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
280                         } else {
281                                 $encoder_options = strtoupper($info['audio']['bitrate_mode']);
282                         }
283
284                 }
285                 if (!empty($thisfile_mpeg_audio_lame['bitrate_min'])) {
286                         $encoder_options .= ' -b'.$thisfile_mpeg_audio_lame['bitrate_min'];
287                 }
288
289                 if (!empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev']) || !empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_next'])) {
290                         $encoder_options .= ' --nogap';
291                 }
292
293                 if (!empty($thisfile_mpeg_audio_lame['lowpass_frequency'])) {
294                         $ExplodedOptions = explode(' ', $encoder_options, 4);
295                         if ($ExplodedOptions[0] == '--r3mix') {
296                                 $ExplodedOptions[1] = 'r3mix';
297                         }
298                         switch ($ExplodedOptions[0]) {
299                                 case '--preset':
300                                 case '--alt-preset':
301                                 case '--r3mix':
302                                         if ($ExplodedOptions[1] == 'fast') {
303                                                 $ExplodedOptions[1] .= ' '.$ExplodedOptions[2];
304                                         }
305                                         switch ($ExplodedOptions[1]) {
306                                                 case 'portable':
307                                                 case 'medium':
308                                                 case 'standard':
309                                                 case 'extreme':
310                                                 case 'insane':
311                                                 case 'fast portable':
312                                                 case 'fast medium':
313                                                 case 'fast standard':
314                                                 case 'fast extreme':
315                                                 case 'fast insane':
316                                                 case 'r3mix':
317                                                         static $ExpectedLowpass = array(
318                                                                         'insane|20500'        => 20500,
319                                                                         'insane|20600'        => 20600,  // 3.90.2, 3.90.3, 3.91
320                                                                         'medium|18000'        => 18000,
321                                                                         'fast medium|18000'   => 18000,
322                                                                         'extreme|19500'       => 19500,  // 3.90,   3.90.1, 3.92, 3.95
323                                                                         'extreme|19600'       => 19600,  // 3.90.2, 3.90.3, 3.91, 3.93.1
324                                                                         'fast extreme|19500'  => 19500,  // 3.90,   3.90.1, 3.92, 3.95
325                                                                         'fast extreme|19600'  => 19600,  // 3.90.2, 3.90.3, 3.91, 3.93.1
326                                                                         'standard|19000'      => 19000,
327                                                                         'fast standard|19000' => 19000,
328                                                                         'r3mix|19500'         => 19500,  // 3.90,   3.90.1, 3.92
329                                                                         'r3mix|19600'         => 19600,  // 3.90.2, 3.90.3, 3.91
330                                                                         'r3mix|18000'         => 18000,  // 3.94,   3.95
331                                                                 );
332                                                         if (!isset($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))) {
333                                                                 $encoder_options .= ' --lowpass '.$thisfile_mpeg_audio_lame['lowpass_frequency'];
334                                                         }
335                                                         break;
336
337                                                 default:
338                                                         break;
339                                         }
340                                         break;
341                         }
342                 }
343
344                 if (isset($thisfile_mpeg_audio_lame['raw']['source_sample_freq'])) {
345                         if (($thisfile_mpeg_audio['sample_rate'] == 44100) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 1)) {
346                                 $encoder_options .= ' --resample 44100';
347                         } elseif (($thisfile_mpeg_audio['sample_rate'] == 48000) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 2)) {
348                                 $encoder_options .= ' --resample 48000';
349                         } elseif ($thisfile_mpeg_audio['sample_rate'] < 44100) {
350                                 switch ($thisfile_mpeg_audio_lame['raw']['source_sample_freq']) {
351                                         case 0: // <= 32000
352                                                 // may or may not be same as source frequency - ignore
353                                                 break;
354                                         case 1: // 44100
355                                         case 2: // 48000
356                                         case 3: // 48000+
357                                                 $ExplodedOptions = explode(' ', $encoder_options, 4);
358                                                 switch ($ExplodedOptions[0]) {
359                                                         case '--preset':
360                                                         case '--alt-preset':
361                                                                 switch ($ExplodedOptions[1]) {
362                                                                         case 'fast':
363                                                                         case 'portable':
364                                                                         case 'medium':
365                                                                         case 'standard':
366                                                                         case 'extreme':
367                                                                         case 'insane':
368                                                                                 $encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
369                                                                                 break;
370
371                                                                         default:
372                                                                                 static $ExpectedResampledRate = array(
373                                                                                                 'phon+/lw/mw-eu/sw|16000' => 16000,
374                                                                                                 'mw-us|24000'             => 24000, // 3.95
375                                                                                                 'mw-us|32000'             => 32000, // 3.93
376                                                                                                 'mw-us|16000'             => 16000, // 3.92
377                                                                                                 'phone|16000'             => 16000,
378                                                                                                 'phone|11025'             => 11025, // 3.94a15
379                                                                                                 'radio|32000'             => 32000, // 3.94a15
380                                                                                                 'fm/radio|32000'          => 32000, // 3.92
381                                                                                                 'fm|32000'                => 32000, // 3.90
382                                                                                                 'voice|32000'             => 32000);
383                                                                                 if (!isset($ExpectedResampledRate[$ExplodedOptions[1].'|'.$thisfile_mpeg_audio['sample_rate']])) {
384                                                                                         $encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
385                                                                                 }
386                                                                                 break;
387                                                                 }
388                                                                 break;
389
390                                                         case '--r3mix':
391                                                         default:
392                                                                 $encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
393                                                                 break;
394                                                 }
395                                                 break;
396                                 }
397                         }
398                 }
399                 if (empty($encoder_options) && !empty($info['audio']['bitrate']) && !empty($info['audio']['bitrate_mode'])) {
400                         //$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
401                         $encoder_options = strtoupper($info['audio']['bitrate_mode']);
402                 }
403
404                 return $encoder_options;
405         }
406
407
408         public function decodeMPEGaudioHeader($offset, &$info, $recursivesearch=true, $ScanAsCBR=false, $FastMPEGheaderScan=false) {
409                 static $MPEGaudioVersionLookup;
410                 static $MPEGaudioLayerLookup;
411                 static $MPEGaudioBitrateLookup;
412                 static $MPEGaudioFrequencyLookup;
413                 static $MPEGaudioChannelModeLookup;
414                 static $MPEGaudioModeExtensionLookup;
415                 static $MPEGaudioEmphasisLookup;
416                 if (empty($MPEGaudioVersionLookup)) {
417                         $MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();
418                         $MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();
419                         $MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();
420                         $MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();
421                         $MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();
422                         $MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
423                         $MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();
424                 }
425
426                 if ($this->fseek($offset) != 0) {
427                         $info['error'][] = 'decodeMPEGaudioHeader() failed to seek to next offset at '.$offset;
428                         return false;
429                 }
430                 //$headerstring = $this->fread(1441); // worst-case max length = 32kHz @ 320kbps layer 3 = 1441 bytes/frame
431                 $headerstring = $this->fread(226); // LAME header at offset 36 + 190 bytes of Xing/LAME data
432
433                 // MP3 audio frame structure:
434                 // $aa $aa $aa $aa [$bb $bb] $cc...
435                 // where $aa..$aa is the four-byte mpeg-audio header (below)
436                 // $bb $bb is the optional 2-byte CRC
437                 // and $cc... is the audio data
438
439                 $head4 = substr($headerstring, 0, 4);
440
441                 static $MPEGaudioHeaderDecodeCache = array();
442                 if (isset($MPEGaudioHeaderDecodeCache[$head4])) {
443                         $MPEGheaderRawArray = $MPEGaudioHeaderDecodeCache[$head4];
444                 } else {
445                         $MPEGheaderRawArray = self::MPEGaudioHeaderDecode($head4);
446                         $MPEGaudioHeaderDecodeCache[$head4] = $MPEGheaderRawArray;
447                 }
448
449                 static $MPEGaudioHeaderValidCache = array();
450                 if (!isset($MPEGaudioHeaderValidCache[$head4])) { // Not in cache
451                         //$MPEGaudioHeaderValidCache[$head4] = self::MPEGaudioHeaderValid($MPEGheaderRawArray, false, true);  // allow badly-formatted freeformat (from LAME 3.90 - 3.93.1)
452                         $MPEGaudioHeaderValidCache[$head4] = self::MPEGaudioHeaderValid($MPEGheaderRawArray, false, false);
453                 }
454
455                 // shortcut
456                 if (!isset($info['mpeg']['audio'])) {
457                         $info['mpeg']['audio'] = array();
458                 }
459                 $thisfile_mpeg_audio = &$info['mpeg']['audio'];
460
461
462                 if ($MPEGaudioHeaderValidCache[$head4]) {
463                         $thisfile_mpeg_audio['raw'] = $MPEGheaderRawArray;
464                 } else {
465                         $info['error'][] = 'Invalid MPEG audio header ('.getid3_lib::PrintHexBytes($head4).') at offset '.$offset;
466                         return false;
467                 }
468
469                 if (!$FastMPEGheaderScan) {
470                         $thisfile_mpeg_audio['version']       = $MPEGaudioVersionLookup[$thisfile_mpeg_audio['raw']['version']];
471                         $thisfile_mpeg_audio['layer']         = $MPEGaudioLayerLookup[$thisfile_mpeg_audio['raw']['layer']];
472
473                         $thisfile_mpeg_audio['channelmode']   = $MPEGaudioChannelModeLookup[$thisfile_mpeg_audio['raw']['channelmode']];
474                         $thisfile_mpeg_audio['channels']      = (($thisfile_mpeg_audio['channelmode'] == 'mono') ? 1 : 2);
475                         $thisfile_mpeg_audio['sample_rate']   = $MPEGaudioFrequencyLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['raw']['sample_rate']];
476                         $thisfile_mpeg_audio['protection']    = !$thisfile_mpeg_audio['raw']['protection'];
477                         $thisfile_mpeg_audio['private']       = (bool) $thisfile_mpeg_audio['raw']['private'];
478                         $thisfile_mpeg_audio['modeextension'] = $MPEGaudioModeExtensionLookup[$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['modeextension']];
479                         $thisfile_mpeg_audio['copyright']     = (bool) $thisfile_mpeg_audio['raw']['copyright'];
480                         $thisfile_mpeg_audio['original']      = (bool) $thisfile_mpeg_audio['raw']['original'];
481                         $thisfile_mpeg_audio['emphasis']      = $MPEGaudioEmphasisLookup[$thisfile_mpeg_audio['raw']['emphasis']];
482
483                         $info['audio']['channels']    = $thisfile_mpeg_audio['channels'];
484                         $info['audio']['sample_rate'] = $thisfile_mpeg_audio['sample_rate'];
485
486                         if ($thisfile_mpeg_audio['protection']) {
487                                 $thisfile_mpeg_audio['crc'] = getid3_lib::BigEndian2Int(substr($headerstring, 4, 2));
488                         }
489                 }
490
491                 if ($thisfile_mpeg_audio['raw']['bitrate'] == 15) {
492                         // http://www.hydrogenaudio.org/?act=ST&f=16&t=9682&st=0
493                         $info['warning'][] = 'Invalid bitrate index (15), this is a known bug in free-format MP3s encoded by LAME v3.90 - 3.93.1';
494                         $thisfile_mpeg_audio['raw']['bitrate'] = 0;
495                 }
496                 $thisfile_mpeg_audio['padding'] = (bool) $thisfile_mpeg_audio['raw']['padding'];
497                 $thisfile_mpeg_audio['bitrate'] = $MPEGaudioBitrateLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['bitrate']];
498
499                 if (($thisfile_mpeg_audio['bitrate'] == 'free') && ($offset == $info['avdataoffset'])) {
500                         // only skip multiple frame check if free-format bitstream found at beginning of file
501                         // otherwise is quite possibly simply corrupted data
502                         $recursivesearch = false;
503                 }
504
505                 // For Layer 2 there are some combinations of bitrate and mode which are not allowed.
506                 if (!$FastMPEGheaderScan && ($thisfile_mpeg_audio['layer'] == '2')) {
507
508                         $info['audio']['dataformat'] = 'mp2';
509                         switch ($thisfile_mpeg_audio['channelmode']) {
510
511                                 case 'mono':
512                                         if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] <= 192000)) {
513                                                 // these are ok
514                                         } else {
515                                                 $info['error'][] = $thisfile_mpeg_audio['bitrate'].'kbps not allowed in Layer 2, '.$thisfile_mpeg_audio['channelmode'].'.';
516                                                 return false;
517                                         }
518                                         break;
519
520                                 case 'stereo':
521                                 case 'joint stereo':
522                                 case 'dual channel':
523                                         if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] == 64000) || ($thisfile_mpeg_audio['bitrate'] >= 96000)) {
524                                                 // these are ok
525                                         } else {
526                                                 $info['error'][] = intval(round($thisfile_mpeg_audio['bitrate'] / 1000)).'kbps not allowed in Layer 2, '.$thisfile_mpeg_audio['channelmode'].'.';
527                                                 return false;
528                                         }
529                                         break;
530
531                         }
532
533                 }
534
535
536                 if ($info['audio']['sample_rate'] > 0) {
537                         $thisfile_mpeg_audio['framelength'] = self::MPEGaudioFrameLength($thisfile_mpeg_audio['bitrate'], $thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['layer'], (int) $thisfile_mpeg_audio['padding'], $info['audio']['sample_rate']);
538                 }
539
540                 $nextframetestoffset = $offset + 1;
541                 if ($thisfile_mpeg_audio['bitrate'] != 'free') {
542
543                         $info['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];
544
545                         if (isset($thisfile_mpeg_audio['framelength'])) {
546                                 $nextframetestoffset = $offset + $thisfile_mpeg_audio['framelength'];
547                         } else {
548                                 $info['error'][] = 'Frame at offset('.$offset.') is has an invalid frame length.';
549                                 return false;
550                         }
551
552                 }
553
554                 $ExpectedNumberOfAudioBytes = 0;
555
556                 ////////////////////////////////////////////////////////////////////////////////////
557                 // Variable-bitrate headers
558
559                 if (substr($headerstring, 4 + 32, 4) == 'VBRI') {
560                         // Fraunhofer VBR header is hardcoded 'VBRI' at offset 0x24 (36)
561                         // specs taken from http://minnie.tuhs.org/pipermail/mp3encoder/2001-January/001800.html
562
563                         $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
564                         $thisfile_mpeg_audio['VBR_method']   = 'Fraunhofer';
565                         $info['audio']['codec']                = 'Fraunhofer';
566
567                         $SideInfoData = substr($headerstring, 4 + 2, 32);
568
569                         $FraunhoferVBROffset = 36;
570
571                         $thisfile_mpeg_audio['VBR_encoder_version']     = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  4, 2)); // VbriVersion
572                         $thisfile_mpeg_audio['VBR_encoder_delay']       = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  6, 2)); // VbriDelay
573                         $thisfile_mpeg_audio['VBR_quality']             = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  8, 2)); // VbriQuality
574                         $thisfile_mpeg_audio['VBR_bytes']               = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 10, 4)); // VbriStreamBytes
575                         $thisfile_mpeg_audio['VBR_frames']              = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 14, 4)); // VbriStreamFrames
576                         $thisfile_mpeg_audio['VBR_seek_offsets']        = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 18, 2)); // VbriTableSize
577                         $thisfile_mpeg_audio['VBR_seek_scale']          = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 20, 2)); // VbriTableScale
578                         $thisfile_mpeg_audio['VBR_entry_bytes']         = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 22, 2)); // VbriEntryBytes
579                         $thisfile_mpeg_audio['VBR_entry_frames']        = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 24, 2)); // VbriEntryFrames
580
581                         $ExpectedNumberOfAudioBytes = $thisfile_mpeg_audio['VBR_bytes'];
582
583                         $previousbyteoffset = $offset;
584                         for ($i = 0; $i < $thisfile_mpeg_audio['VBR_seek_offsets']; $i++) {
585                                 $Fraunhofer_OffsetN = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset, $thisfile_mpeg_audio['VBR_entry_bytes']));
586                                 $FraunhoferVBROffset += $thisfile_mpeg_audio['VBR_entry_bytes'];
587                                 $thisfile_mpeg_audio['VBR_offsets_relative'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']);
588                                 $thisfile_mpeg_audio['VBR_offsets_absolute'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']) + $previousbyteoffset;
589                                 $previousbyteoffset += $Fraunhofer_OffsetN;
590                         }
591
592
593                 } else {
594
595                         // Xing VBR header is hardcoded 'Xing' at a offset 0x0D (13), 0x15 (21) or 0x24 (36)
596                         // depending on MPEG layer and number of channels
597
598                         $VBRidOffset = self::XingVBRidOffset($thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['channelmode']);
599                         $SideInfoData = substr($headerstring, 4 + 2, $VBRidOffset - 4);
600
601                         if ((substr($headerstring, $VBRidOffset, strlen('Xing')) == 'Xing') || (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Info')) {
602                                 // 'Xing' is traditional Xing VBR frame
603                                 // 'Info' is LAME-encoded CBR (This was done to avoid CBR files to be recognized as traditional Xing VBR files by some decoders.)
604                                 // 'Info' *can* legally be used to specify a VBR file as well, however.
605
606                                 // http://www.multiweb.cz/twoinches/MP3inside.htm
607                                 //00..03 = "Xing" or "Info"
608                                 //04..07 = Flags:
609                                 //  0x01  Frames Flag     set if value for number of frames in file is stored
610                                 //  0x02  Bytes Flag      set if value for filesize in bytes is stored
611                                 //  0x04  TOC Flag        set if values for TOC are stored
612                                 //  0x08  VBR Scale Flag  set if values for VBR scale is stored
613                                 //08..11  Frames: Number of frames in file (including the first Xing/Info one)
614                                 //12..15  Bytes:  File length in Bytes
615                                 //16..115  TOC (Table of Contents):
616                                 //  Contains of 100 indexes (one Byte length) for easier lookup in file. Approximately solves problem with moving inside file.
617                                 //  Each Byte has a value according this formula:
618                                 //  (TOC[i] / 256) * fileLenInBytes
619                                 //  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:
620                                 //  TOC[(60/240)*100] = TOC[25]
621                                 //  and corresponding Byte in file is then approximately at:
622                                 //  (TOC[25]/256) * 5000000
623                                 //116..119  VBR Scale
624
625
626                                 // should be safe to leave this at 'vbr' and let it be overriden to 'cbr' if a CBR preset/mode is used by LAME
627 //                              if (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Xing') {
628                                         $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
629                                         $thisfile_mpeg_audio['VBR_method']   = 'Xing';
630 //                              } else {
631 //                                      $ScanAsCBR = true;
632 //                                      $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
633 //                              }
634
635                                 $thisfile_mpeg_audio['xing_flags_raw'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 4, 4));
636
637                                 $thisfile_mpeg_audio['xing_flags']['frames']    = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000001);
638                                 $thisfile_mpeg_audio['xing_flags']['bytes']     = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000002);
639                                 $thisfile_mpeg_audio['xing_flags']['toc']       = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000004);
640                                 $thisfile_mpeg_audio['xing_flags']['vbr_scale'] = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000008);
641
642                                 if ($thisfile_mpeg_audio['xing_flags']['frames']) {
643                                         $thisfile_mpeg_audio['VBR_frames'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset +  8, 4));
644                                         //$thisfile_mpeg_audio['VBR_frames']--; // don't count header Xing/Info frame
645                                 }
646                                 if ($thisfile_mpeg_audio['xing_flags']['bytes']) {
647                                         $thisfile_mpeg_audio['VBR_bytes']  = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 12, 4));
648                                 }
649
650                                 //if (($thisfile_mpeg_audio['bitrate'] == 'free') && !empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {
651                                 if (!empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {
652
653                                         $framelengthfloat = $thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames'];
654
655                                         if ($thisfile_mpeg_audio['layer'] == '1') {
656                                                 // BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
657                                                 //$info['audio']['bitrate'] = ((($framelengthfloat / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
658                                                 $info['audio']['bitrate'] = ($framelengthfloat / 4) * $thisfile_mpeg_audio['sample_rate'] * (2 / $info['audio']['channels']) / 12;
659                                         } else {
660                                                 // Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
661                                                 //$info['audio']['bitrate'] = (($framelengthfloat - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
662                                                 $info['audio']['bitrate'] = $framelengthfloat * $thisfile_mpeg_audio['sample_rate'] * (2 / $info['audio']['channels']) / 144;
663                                         }
664                                         $thisfile_mpeg_audio['framelength'] = floor($framelengthfloat);
665                                 }
666
667                                 if ($thisfile_mpeg_audio['xing_flags']['toc']) {
668                                         $LAMEtocData = substr($headerstring, $VBRidOffset + 16, 100);
669                                         for ($i = 0; $i < 100; $i++) {
670                                                 $thisfile_mpeg_audio['toc'][$i] = ord($LAMEtocData{$i});
671                                         }
672                                 }
673                                 if ($thisfile_mpeg_audio['xing_flags']['vbr_scale']) {
674                                         $thisfile_mpeg_audio['VBR_scale'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 116, 4));
675                                 }
676
677
678                                 // http://gabriel.mp3-tech.org/mp3infotag.html
679                                 if (substr($headerstring, $VBRidOffset + 120, 4) == 'LAME') {
680
681                                         // shortcut
682                                         $thisfile_mpeg_audio['LAME'] = array();
683                                         $thisfile_mpeg_audio_lame    = &$thisfile_mpeg_audio['LAME'];
684
685
686                                         $thisfile_mpeg_audio_lame['long_version']  = substr($headerstring, $VBRidOffset + 120, 20);
687                                         $thisfile_mpeg_audio_lame['short_version'] = substr($thisfile_mpeg_audio_lame['long_version'], 0, 9);
688
689                                         if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.90') {
690
691                                                 // extra 11 chars are not part of version string when LAMEtag present
692                                                 unset($thisfile_mpeg_audio_lame['long_version']);
693
694                                                 // It the LAME tag was only introduced in LAME v3.90
695                                                 // http://www.hydrogenaudio.org/?act=ST&f=15&t=9933
696
697                                                 // Offsets of various bytes in http://gabriel.mp3-tech.org/mp3infotag.html
698                                                 // are assuming a 'Xing' identifier offset of 0x24, which is the case for
699                                                 // MPEG-1 non-mono, but not for other combinations
700                                                 $LAMEtagOffsetContant = $VBRidOffset - 0x24;
701
702                                                 // shortcuts
703                                                 $thisfile_mpeg_audio_lame['RGAD']    = array('track'=>array(), 'album'=>array());
704                                                 $thisfile_mpeg_audio_lame_RGAD       = &$thisfile_mpeg_audio_lame['RGAD'];
705                                                 $thisfile_mpeg_audio_lame_RGAD_track = &$thisfile_mpeg_audio_lame_RGAD['track'];
706                                                 $thisfile_mpeg_audio_lame_RGAD_album = &$thisfile_mpeg_audio_lame_RGAD['album'];
707                                                 $thisfile_mpeg_audio_lame['raw'] = array();
708                                                 $thisfile_mpeg_audio_lame_raw    = &$thisfile_mpeg_audio_lame['raw'];
709
710                                                 // byte $9B  VBR Quality
711                                                 // This field is there to indicate a quality level, although the scale was not precised in the original Xing specifications.
712                                                 // Actually overwrites original Xing bytes
713                                                 unset($thisfile_mpeg_audio['VBR_scale']);
714                                                 $thisfile_mpeg_audio_lame['vbr_quality'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0x9B, 1));
715
716                                                 // bytes $9C-$A4  Encoder short VersionString
717                                                 $thisfile_mpeg_audio_lame['short_version'] = substr($headerstring, $LAMEtagOffsetContant + 0x9C, 9);
718
719                                                 // byte $A5  Info Tag revision + VBR method
720                                                 $LAMEtagRevisionVBRmethod = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA5, 1));
721
722                                                 $thisfile_mpeg_audio_lame['tag_revision']   = ($LAMEtagRevisionVBRmethod & 0xF0) >> 4;
723                                                 $thisfile_mpeg_audio_lame_raw['vbr_method'] =  $LAMEtagRevisionVBRmethod & 0x0F;
724                                                 $thisfile_mpeg_audio_lame['vbr_method']     = self::LAMEvbrMethodLookup($thisfile_mpeg_audio_lame_raw['vbr_method']);
725                                                 $thisfile_mpeg_audio['bitrate_mode']        = substr($thisfile_mpeg_audio_lame['vbr_method'], 0, 3); // usually either 'cbr' or 'vbr', but truncates 'vbr-old / vbr-rh' to 'vbr'
726
727                                                 // byte $A6  Lowpass filter value
728                                                 $thisfile_mpeg_audio_lame['lowpass_frequency'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA6, 1)) * 100;
729
730                                                 // bytes $A7-$AE  Replay Gain
731                                                 // http://privatewww.essex.ac.uk/~djmrob/replaygain/rg_data_format.html
732                                                 // bytes $A7-$AA : 32 bit floating point "Peak signal amplitude"
733                                                 if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.94b') {
734                                                         // LAME 3.94a16 and later - 9.23 fixed point
735                                                         // ie 0x0059E2EE / (2^23) = 5890798 / 8388608 = 0.7022378444671630859375
736                                                         $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = (float) ((getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4))) / 8388608);
737                                                 } else {
738                                                         // LAME 3.94a15 and earlier - 32-bit floating point
739                                                         // Actually 3.94a16 will fall in here too and be WRONG, but is hard to detect 3.94a16 vs 3.94a15
740                                                         $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = getid3_lib::LittleEndian2Float(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4));
741                                                 }
742                                                 if ($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] == 0) {
743                                                         unset($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);
744                                                 } else {
745                                                         $thisfile_mpeg_audio_lame_RGAD['peak_db'] = getid3_lib::RGADamplitude2dB($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);
746                                                 }
747
748                                                 $thisfile_mpeg_audio_lame_raw['RGAD_track']      =   getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAB, 2));
749                                                 $thisfile_mpeg_audio_lame_raw['RGAD_album']      =   getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAD, 2));
750
751
752                                                 if ($thisfile_mpeg_audio_lame_raw['RGAD_track'] != 0) {
753
754                                                         $thisfile_mpeg_audio_lame_RGAD_track['raw']['name']        = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0xE000) >> 13;
755                                                         $thisfile_mpeg_audio_lame_RGAD_track['raw']['originator']  = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x1C00) >> 10;
756                                                         $thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit']    = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x0200) >> 9;
757                                                         $thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'] =  $thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x01FF;
758                                                         $thisfile_mpeg_audio_lame_RGAD_track['name']       = getid3_lib::RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['name']);
759                                                         $thisfile_mpeg_audio_lame_RGAD_track['originator'] = getid3_lib::RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['originator']);
760                                                         $thisfile_mpeg_audio_lame_RGAD_track['gain_db']    = getid3_lib::RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit']);
761
762                                                         if (!empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'])) {
763                                                                 $info['replay_gain']['track']['peak']   = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];
764                                                         }
765                                                         $info['replay_gain']['track']['originator'] = $thisfile_mpeg_audio_lame_RGAD_track['originator'];
766                                                         $info['replay_gain']['track']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_track['gain_db'];
767                                                 } else {
768                                                         unset($thisfile_mpeg_audio_lame_RGAD['track']);
769                                                 }
770                                                 if ($thisfile_mpeg_audio_lame_raw['RGAD_album'] != 0) {
771
772                                                         $thisfile_mpeg_audio_lame_RGAD_album['raw']['name']        = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0xE000) >> 13;
773                                                         $thisfile_mpeg_audio_lame_RGAD_album['raw']['originator']  = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x1C00) >> 10;
774                                                         $thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit']    = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x0200) >> 9;
775                                                         $thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'] = $thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x01FF;
776                                                         $thisfile_mpeg_audio_lame_RGAD_album['name']       = getid3_lib::RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['name']);
777                                                         $thisfile_mpeg_audio_lame_RGAD_album['originator'] = getid3_lib::RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['originator']);
778                                                         $thisfile_mpeg_audio_lame_RGAD_album['gain_db']    = getid3_lib::RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit']);
779
780                                                         if (!empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'])) {
781                                                                 $info['replay_gain']['album']['peak']   = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];
782                                                         }
783                                                         $info['replay_gain']['album']['originator'] = $thisfile_mpeg_audio_lame_RGAD_album['originator'];
784                                                         $info['replay_gain']['album']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_album['gain_db'];
785                                                 } else {
786                                                         unset($thisfile_mpeg_audio_lame_RGAD['album']);
787                                                 }
788                                                 if (empty($thisfile_mpeg_audio_lame_RGAD)) {
789                                                         unset($thisfile_mpeg_audio_lame['RGAD']);
790                                                 }
791
792
793                                                 // byte $AF  Encoding flags + ATH Type
794                                                 $EncodingFlagsATHtype = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAF, 1));
795                                                 $thisfile_mpeg_audio_lame['encoding_flags']['nspsytune']   = (bool) ($EncodingFlagsATHtype & 0x10);
796                                                 $thisfile_mpeg_audio_lame['encoding_flags']['nssafejoint'] = (bool) ($EncodingFlagsATHtype & 0x20);
797                                                 $thisfile_mpeg_audio_lame['encoding_flags']['nogap_next']  = (bool) ($EncodingFlagsATHtype & 0x40);
798                                                 $thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev']  = (bool) ($EncodingFlagsATHtype & 0x80);
799                                                 $thisfile_mpeg_audio_lame['ath_type']                      =         $EncodingFlagsATHtype & 0x0F;
800
801                                                 // byte $B0  if ABR {specified bitrate} else {minimal bitrate}
802                                                 $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB0, 1));
803                                                 if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 2) { // Average BitRate (ABR)
804                                                         $thisfile_mpeg_audio_lame['bitrate_abr'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];
805                                                 } elseif ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1) { // Constant BitRate (CBR)
806                                                         // ignore
807                                                 } elseif ($thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] > 0) { // Variable BitRate (VBR) - minimum bitrate
808                                                         $thisfile_mpeg_audio_lame['bitrate_min'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];
809                                                 }
810
811                                                 // bytes $B1-$B3  Encoder delays
812                                                 $EncoderDelays = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB1, 3));
813                                                 $thisfile_mpeg_audio_lame['encoder_delay'] = ($EncoderDelays & 0xFFF000) >> 12;
814                                                 $thisfile_mpeg_audio_lame['end_padding']   =  $EncoderDelays & 0x000FFF;
815
816                                                 // byte $B4  Misc
817                                                 $MiscByte = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB4, 1));
818                                                 $thisfile_mpeg_audio_lame_raw['noise_shaping']       = ($MiscByte & 0x03);
819                                                 $thisfile_mpeg_audio_lame_raw['stereo_mode']         = ($MiscByte & 0x1C) >> 2;
820                                                 $thisfile_mpeg_audio_lame_raw['not_optimal_quality'] = ($MiscByte & 0x20) >> 5;
821                                                 $thisfile_mpeg_audio_lame_raw['source_sample_freq']  = ($MiscByte & 0xC0) >> 6;
822                                                 $thisfile_mpeg_audio_lame['noise_shaping']       = $thisfile_mpeg_audio_lame_raw['noise_shaping'];
823                                                 $thisfile_mpeg_audio_lame['stereo_mode']         = self::LAMEmiscStereoModeLookup($thisfile_mpeg_audio_lame_raw['stereo_mode']);
824                                                 $thisfile_mpeg_audio_lame['not_optimal_quality'] = (bool) $thisfile_mpeg_audio_lame_raw['not_optimal_quality'];
825                                                 $thisfile_mpeg_audio_lame['source_sample_freq']  = self::LAMEmiscSourceSampleFrequencyLookup($thisfile_mpeg_audio_lame_raw['source_sample_freq']);
826
827                                                 // byte $B5  MP3 Gain
828                                                 $thisfile_mpeg_audio_lame_raw['mp3_gain'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB5, 1), false, true);
829                                                 $thisfile_mpeg_audio_lame['mp3_gain_db']     = (getid3_lib::RGADamplitude2dB(2) / 4) * $thisfile_mpeg_audio_lame_raw['mp3_gain'];
830                                                 $thisfile_mpeg_audio_lame['mp3_gain_factor'] = pow(2, ($thisfile_mpeg_audio_lame['mp3_gain_db'] / 6));
831
832                                                 // bytes $B6-$B7  Preset and surround info
833                                                 $PresetSurroundBytes = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB6, 2));
834                                                 // Reserved                                                    = ($PresetSurroundBytes & 0xC000);
835                                                 $thisfile_mpeg_audio_lame_raw['surround_info'] = ($PresetSurroundBytes & 0x3800);
836                                                 $thisfile_mpeg_audio_lame['surround_info']     = self::LAMEsurroundInfoLookup($thisfile_mpeg_audio_lame_raw['surround_info']);
837                                                 $thisfile_mpeg_audio_lame['preset_used_id']    = ($PresetSurroundBytes & 0x07FF);
838                                                 $thisfile_mpeg_audio_lame['preset_used']       = self::LAMEpresetUsedLookup($thisfile_mpeg_audio_lame);
839                                                 if (!empty($thisfile_mpeg_audio_lame['preset_used_id']) && empty($thisfile_mpeg_audio_lame['preset_used'])) {
840                                                         $info['warning'][] = 'Unknown LAME preset used ('.$thisfile_mpeg_audio_lame['preset_used_id'].') - please report to info@getid3.org';
841                                                 }
842                                                 if (($thisfile_mpeg_audio_lame['short_version'] == 'LAME3.90.') && !empty($thisfile_mpeg_audio_lame['preset_used_id'])) {
843                                                         // this may change if 3.90.4 ever comes out
844                                                         $thisfile_mpeg_audio_lame['short_version'] = 'LAME3.90.3';
845                                                 }
846
847                                                 // bytes $B8-$BB  MusicLength
848                                                 $thisfile_mpeg_audio_lame['audio_bytes'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB8, 4));
849                                                 $ExpectedNumberOfAudioBytes = (($thisfile_mpeg_audio_lame['audio_bytes'] > 0) ? $thisfile_mpeg_audio_lame['audio_bytes'] : $thisfile_mpeg_audio['VBR_bytes']);
850
851                                                 // bytes $BC-$BD  MusicCRC
852                                                 $thisfile_mpeg_audio_lame['music_crc']    = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBC, 2));
853
854                                                 // bytes $BE-$BF  CRC-16 of Info Tag
855                                                 $thisfile_mpeg_audio_lame['lame_tag_crc'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBE, 2));
856
857
858                                                 // LAME CBR
859                                                 if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1) {
860
861                                                         $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
862                                                         $thisfile_mpeg_audio['bitrate'] = self::ClosestStandardMP3Bitrate($thisfile_mpeg_audio['bitrate']);
863                                                         $info['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];
864                                                         //if (empty($thisfile_mpeg_audio['bitrate']) || (!empty($thisfile_mpeg_audio_lame['bitrate_min']) && ($thisfile_mpeg_audio_lame['bitrate_min'] != 255))) {
865                                                         //      $thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio_lame['bitrate_min'];
866                                                         //}
867
868                                                 }
869
870                                         }
871                                 }
872
873                         } else {
874
875                                 // not Fraunhofer or Xing VBR methods, most likely CBR (but could be VBR with no header)
876                                 $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
877                                 if ($recursivesearch) {
878                                         $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
879                                         if ($this->RecursiveFrameScanning($offset, $nextframetestoffset, true)) {
880                                                 $recursivesearch = false;
881                                                 $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
882                                         }
883                                         if ($thisfile_mpeg_audio['bitrate_mode'] == 'vbr') {
884                                                 $info['warning'][] = 'VBR file with no VBR header. Bitrate values calculated from actual frame bitrates.';
885                                         }
886                                 }
887
888                         }
889
890                 }
891
892                 if (($ExpectedNumberOfAudioBytes > 0) && ($ExpectedNumberOfAudioBytes != ($info['avdataend'] - $info['avdataoffset']))) {
893                         if ($ExpectedNumberOfAudioBytes > ($info['avdataend'] - $info['avdataoffset'])) {
894                                 if ($this->isDependencyFor('matroska') || $this->isDependencyFor('riff')) {
895                                         // ignore, audio data is broken into chunks so will always be data "missing"
896                                 }
897                                 elseif (($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])) == 1) {
898                                         $this->warning('Last byte of data truncated (this is a known bug in Meracl ID3 Tag Writer before v1.3.5)');
899                                 }
900                                 else {
901                                         $this->warning('Probable truncated file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, only found '.($info['avdataend'] - $info['avdataoffset']).' (short by '.($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])).' bytes)');
902                                 }
903                         } else {
904                                 if ((($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes) == 1) {
905                                 //      $prenullbytefileoffset = $this->ftell();
906                                 //      $this->fseek($info['avdataend']);
907                                 //      $PossibleNullByte = $this->fread(1);
908                                 //      $this->fseek($prenullbytefileoffset);
909                                 //      if ($PossibleNullByte === "\x00") {
910                                                 $info['avdataend']--;
911                                 //              $info['warning'][] = 'Extra null byte at end of MP3 data assumed to be RIFF padding and therefore ignored';
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                                 } else {
916                                         $info['warning'][] = 'Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']).' ('.(($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)';
917                                 }
918                         }
919                 }
920
921                 if (($thisfile_mpeg_audio['bitrate'] == 'free') && empty($info['audio']['bitrate'])) {
922                         if (($offset == $info['avdataoffset']) && empty($thisfile_mpeg_audio['VBR_frames'])) {
923                                 $framebytelength = $this->FreeFormatFrameLength($offset, true);
924                                 if ($framebytelength > 0) {
925                                         $thisfile_mpeg_audio['framelength'] = $framebytelength;
926                                         if ($thisfile_mpeg_audio['layer'] == '1') {
927                                                 // BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
928                                                 $info['audio']['bitrate'] = ((($framebytelength / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
929                                         } else {
930                                                 // Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
931                                                 $info['audio']['bitrate'] = (($framebytelength - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
932                                         }
933                                 } else {
934                                         $info['error'][] = 'Error calculating frame length of free-format MP3 without Xing/LAME header';
935                                 }
936                         }
937                 }
938
939                 if (isset($thisfile_mpeg_audio['VBR_frames']) ? $thisfile_mpeg_audio['VBR_frames'] : '') {
940                         switch ($thisfile_mpeg_audio['bitrate_mode']) {
941                                 case 'vbr':
942                                 case 'abr':
943                                         $bytes_per_frame = 1152;
944                                         if (($thisfile_mpeg_audio['version'] == '1') && ($thisfile_mpeg_audio['layer'] == 1)) {
945                                                 $bytes_per_frame = 384;
946                                         } elseif ((($thisfile_mpeg_audio['version'] == '2') || ($thisfile_mpeg_audio['version'] == '2.5')) && ($thisfile_mpeg_audio['layer'] == 3)) {
947                                                 $bytes_per_frame = 576;
948                                         }
949                                         $thisfile_mpeg_audio['VBR_bitrate'] = (isset($thisfile_mpeg_audio['VBR_bytes']) ? (($thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames']) * 8) * ($info['audio']['sample_rate'] / $bytes_per_frame) : 0);
950                                         if ($thisfile_mpeg_audio['VBR_bitrate'] > 0) {
951                                                 $info['audio']['bitrate']         = $thisfile_mpeg_audio['VBR_bitrate'];
952                                                 $thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio['VBR_bitrate']; // to avoid confusion
953                                         }
954                                         break;
955                         }
956                 }
957
958                 // End variable-bitrate headers
959                 ////////////////////////////////////////////////////////////////////////////////////
960
961                 if ($recursivesearch) {
962
963                         if (!$this->RecursiveFrameScanning($offset, $nextframetestoffset, $ScanAsCBR)) {
964                                 return false;
965                         }
966
967                 }
968
969
970                 //if (false) {
971                 //    // experimental side info parsing section - not returning anything useful yet
972                 //
973                 //    $SideInfoBitstream = getid3_lib::BigEndian2Bin($SideInfoData);
974                 //    $SideInfoOffset = 0;
975                 //
976                 //    if ($thisfile_mpeg_audio['version'] == '1') {
977                 //        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
978                 //            // MPEG-1 (mono)
979                 //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
980                 //            $SideInfoOffset += 9;
981                 //            $SideInfoOffset += 5;
982                 //        } else {
983                 //            // MPEG-1 (stereo, joint-stereo, dual-channel)
984                 //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
985                 //            $SideInfoOffset += 9;
986                 //            $SideInfoOffset += 3;
987                 //        }
988                 //    } else { // 2 or 2.5
989                 //        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
990                 //            // MPEG-2, MPEG-2.5 (mono)
991                 //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
992                 //            $SideInfoOffset += 8;
993                 //            $SideInfoOffset += 1;
994                 //        } else {
995                 //            // MPEG-2, MPEG-2.5 (stereo, joint-stereo, dual-channel)
996                 //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
997                 //            $SideInfoOffset += 8;
998                 //            $SideInfoOffset += 2;
999                 //        }
1000                 //    }
1001                 //
1002                 //    if ($thisfile_mpeg_audio['version'] == '1') {
1003                 //        for ($channel = 0; $channel < $info['audio']['channels']; $channel++) {
1004                 //            for ($scfsi_band = 0; $scfsi_band < 4; $scfsi_band++) {
1005                 //                $thisfile_mpeg_audio['scfsi'][$channel][$scfsi_band] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1006                 //                $SideInfoOffset += 2;
1007                 //            }
1008                 //        }
1009                 //    }
1010                 //    for ($granule = 0; $granule < (($thisfile_mpeg_audio['version'] == '1') ? 2 : 1); $granule++) {
1011                 //        for ($channel = 0; $channel < $info['audio']['channels']; $channel++) {
1012                 //            $thisfile_mpeg_audio['part2_3_length'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 12);
1013                 //            $SideInfoOffset += 12;
1014                 //            $thisfile_mpeg_audio['big_values'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1015                 //            $SideInfoOffset += 9;
1016                 //            $thisfile_mpeg_audio['global_gain'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 8);
1017                 //            $SideInfoOffset += 8;
1018                 //            if ($thisfile_mpeg_audio['version'] == '1') {
1019                 //                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
1020                 //                $SideInfoOffset += 4;
1021                 //            } else {
1022                 //                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1023                 //                $SideInfoOffset += 9;
1024                 //            }
1025                 //            $thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1026                 //            $SideInfoOffset += 1;
1027                 //
1028                 //            if ($thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] == '1') {
1029                 //
1030                 //                $thisfile_mpeg_audio['block_type'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 2);
1031                 //                $SideInfoOffset += 2;
1032                 //                $thisfile_mpeg_audio['mixed_block_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1033                 //                $SideInfoOffset += 1;
1034                 //
1035                 //                for ($region = 0; $region < 2; $region++) {
1036                 //                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
1037                 //                    $SideInfoOffset += 5;
1038                 //                }
1039                 //                $thisfile_mpeg_audio['table_select'][$granule][$channel][2] = 0;
1040                 //
1041                 //                for ($window = 0; $window < 3; $window++) {
1042                 //                    $thisfile_mpeg_audio['subblock_gain'][$granule][$channel][$window] = substr($SideInfoBitstream, $SideInfoOffset, 3);
1043                 //                    $SideInfoOffset += 3;
1044                 //                }
1045                 //
1046                 //            } else {
1047                 //
1048                 //                for ($region = 0; $region < 3; $region++) {
1049                 //                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
1050                 //                    $SideInfoOffset += 5;
1051                 //                }
1052                 //
1053                 //                $thisfile_mpeg_audio['region0_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
1054                 //                $SideInfoOffset += 4;
1055                 //                $thisfile_mpeg_audio['region1_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 3);
1056                 //                $SideInfoOffset += 3;
1057                 //                $thisfile_mpeg_audio['block_type'][$granule][$channel] = 0;
1058                 //            }
1059                 //
1060                 //            if ($thisfile_mpeg_audio['version'] == '1') {
1061                 //                $thisfile_mpeg_audio['preflag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1062                 //                $SideInfoOffset += 1;
1063                 //            }
1064                 //            $thisfile_mpeg_audio['scalefac_scale'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1065                 //            $SideInfoOffset += 1;
1066                 //            $thisfile_mpeg_audio['count1table_select'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1067                 //            $SideInfoOffset += 1;
1068                 //        }
1069                 //    }
1070                 //}
1071
1072                 return true;
1073         }
1074
1075         public function RecursiveFrameScanning(&$offset, &$nextframetestoffset, $ScanAsCBR) {
1076                 $info = &$this->getid3->info;
1077                 $firstframetestarray = array('error'=>'', 'warning'=>'', 'avdataend'=>$info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1078                 $this->decodeMPEGaudioHeader($offset, $firstframetestarray, false);
1079
1080                 for ($i = 0; $i < GETID3_MP3_VALID_CHECK_FRAMES; $i++) {
1081                         // check next GETID3_MP3_VALID_CHECK_FRAMES frames for validity, to make sure we haven't run across a false synch
1082                         if (($nextframetestoffset + 4) >= $info['avdataend']) {
1083                                 // end of file
1084                                 return true;
1085                         }
1086
1087                         $nextframetestarray = array('error'=>'', 'warning'=>'', 'avdataend'=>$info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1088                         if ($this->decodeMPEGaudioHeader($nextframetestoffset, $nextframetestarray, false)) {
1089                                 if ($ScanAsCBR) {
1090                                         // force CBR mode, used for trying to pick out invalid audio streams with valid(?) VBR headers, or VBR streams with no VBR header
1091                                         if (!isset($nextframetestarray['mpeg']['audio']['bitrate']) || !isset($firstframetestarray['mpeg']['audio']['bitrate']) || ($nextframetestarray['mpeg']['audio']['bitrate'] != $firstframetestarray['mpeg']['audio']['bitrate'])) {
1092                                                 return false;
1093                                         }
1094                                 }
1095
1096
1097                                 // next frame is OK, get ready to check the one after that
1098                                 if (isset($nextframetestarray['mpeg']['audio']['framelength']) && ($nextframetestarray['mpeg']['audio']['framelength'] > 0)) {
1099                                         $nextframetestoffset += $nextframetestarray['mpeg']['audio']['framelength'];
1100                                 } else {
1101                                         $info['error'][] = 'Frame at offset ('.$offset.') is has an invalid frame length.';
1102                                         return false;
1103                                 }
1104
1105                         } elseif (!empty($firstframetestarray['mpeg']['audio']['framelength']) && (($nextframetestoffset + $firstframetestarray['mpeg']['audio']['framelength']) > $info['avdataend'])) {
1106
1107                                 // 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
1108                                 return true;
1109
1110                         } else {
1111
1112                                 // next frame is not valid, note the error and fail, so scanning can contiue for a valid frame sequence
1113                                 $info['warning'][] = 'Frame at offset ('.$offset.') is valid, but the next one at ('.$nextframetestoffset.') is not.';
1114
1115                                 return false;
1116                         }
1117                 }
1118                 return true;
1119         }
1120
1121         public function FreeFormatFrameLength($offset, $deepscan=false) {
1122                 $info = &$this->getid3->info;
1123
1124                 $this->fseek($offset);
1125                 $MPEGaudioData = $this->fread(32768);
1126
1127                 $SyncPattern1 = substr($MPEGaudioData, 0, 4);
1128                 // may be different pattern due to padding
1129                 $SyncPattern2 = $SyncPattern1{0}.$SyncPattern1{1}.chr(ord($SyncPattern1{2}) | 0x02).$SyncPattern1{3};
1130                 if ($SyncPattern2 === $SyncPattern1) {
1131                         $SyncPattern2 = $SyncPattern1{0}.$SyncPattern1{1}.chr(ord($SyncPattern1{2}) & 0xFD).$SyncPattern1{3};
1132                 }
1133
1134                 $framelength = false;
1135                 $framelength1 = strpos($MPEGaudioData, $SyncPattern1, 4);
1136                 $framelength2 = strpos($MPEGaudioData, $SyncPattern2, 4);
1137                 if ($framelength1 > 4) {
1138                         $framelength = $framelength1;
1139                 }
1140                 if (($framelength2 > 4) && ($framelength2 < $framelength1)) {
1141                         $framelength = $framelength2;
1142                 }
1143                 if (!$framelength) {
1144
1145                         // LAME 3.88 has a different value for modeextension on the first frame vs the rest
1146                         $framelength1 = strpos($MPEGaudioData, substr($SyncPattern1, 0, 3), 4);
1147                         $framelength2 = strpos($MPEGaudioData, substr($SyncPattern2, 0, 3), 4);
1148
1149                         if ($framelength1 > 4) {
1150                                 $framelength = $framelength1;
1151                         }
1152                         if (($framelength2 > 4) && ($framelength2 < $framelength1)) {
1153                                 $framelength = $framelength2;
1154                         }
1155                         if (!$framelength) {
1156                                 $info['error'][] = 'Cannot find next free-format synch pattern ('.getid3_lib::PrintHexBytes($SyncPattern1).' or '.getid3_lib::PrintHexBytes($SyncPattern2).') after offset '.$offset;
1157                                 return false;
1158                         } else {
1159                                 $info['warning'][] = 'ModeExtension varies between first frame and other frames (known free-format issue in LAME 3.88)';
1160                                 $info['audio']['codec']   = 'LAME';
1161                                 $info['audio']['encoder'] = 'LAME3.88';
1162                                 $SyncPattern1 = substr($SyncPattern1, 0, 3);
1163                                 $SyncPattern2 = substr($SyncPattern2, 0, 3);
1164                         }
1165                 }
1166
1167                 if ($deepscan) {
1168
1169                         $ActualFrameLengthValues = array();
1170                         $nextoffset = $offset + $framelength;
1171                         while ($nextoffset < ($info['avdataend'] - 6)) {
1172                                 $this->fseek($nextoffset - 1);
1173                                 $NextSyncPattern = $this->fread(6);
1174                                 if ((substr($NextSyncPattern, 1, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 1, strlen($SyncPattern2)) == $SyncPattern2)) {
1175                                         // good - found where expected
1176                                         $ActualFrameLengthValues[] = $framelength;
1177                                 } elseif ((substr($NextSyncPattern, 0, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 0, strlen($SyncPattern2)) == $SyncPattern2)) {
1178                                         // ok - found one byte earlier than expected (last frame wasn't padded, first frame was)
1179                                         $ActualFrameLengthValues[] = ($framelength - 1);
1180                                         $nextoffset--;
1181                                 } elseif ((substr($NextSyncPattern, 2, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 2, strlen($SyncPattern2)) == $SyncPattern2)) {
1182                                         // ok - found one byte later than expected (last frame was padded, first frame wasn't)
1183                                         $ActualFrameLengthValues[] = ($framelength + 1);
1184                                         $nextoffset++;
1185                                 } else {
1186                                         $info['error'][] = 'Did not find expected free-format sync pattern at offset '.$nextoffset;
1187                                         return false;
1188                                 }
1189                                 $nextoffset += $framelength;
1190                         }
1191                         if (count($ActualFrameLengthValues) > 0) {
1192                                 $framelength = intval(round(array_sum($ActualFrameLengthValues) / count($ActualFrameLengthValues)));
1193                         }
1194                 }
1195                 return $framelength;
1196         }
1197
1198         public function getOnlyMPEGaudioInfoBruteForce() {
1199                 $MPEGaudioHeaderDecodeCache   = array();
1200                 $MPEGaudioHeaderValidCache    = array();
1201                 $MPEGaudioHeaderLengthCache   = array();
1202                 $MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();
1203                 $MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();
1204                 $MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();
1205                 $MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();
1206                 $MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();
1207                 $MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
1208                 $MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();
1209                 $LongMPEGversionLookup        = array();
1210                 $LongMPEGlayerLookup          = array();
1211                 $LongMPEGbitrateLookup        = array();
1212                 $LongMPEGpaddingLookup        = array();
1213                 $LongMPEGfrequencyLookup      = array();
1214                 $Distribution['bitrate']      = array();
1215                 $Distribution['frequency']    = array();
1216                 $Distribution['layer']        = array();
1217                 $Distribution['version']      = array();
1218                 $Distribution['padding']      = array();
1219
1220                 $info = &$this->getid3->info;
1221                 $this->fseek($info['avdataoffset']);
1222
1223                 $max_frames_scan = 5000;
1224                 $frames_scanned  = 0;
1225
1226                 $previousvalidframe = $info['avdataoffset'];
1227                 while ($this->ftell() < $info['avdataend']) {
1228                         set_time_limit(30);
1229                         $head4 = $this->fread(4);
1230                         if (strlen($head4) < 4) {
1231                                 break;
1232                         }
1233                         if ($head4{0} != "\xFF") {
1234                                 for ($i = 1; $i < 4; $i++) {
1235                                         if ($head4{$i} == "\xFF") {
1236                                                 $this->fseek($i - 4, SEEK_CUR);
1237                                                 continue 2;
1238                                         }
1239                                 }
1240                                 continue;
1241                         }
1242                         if (!isset($MPEGaudioHeaderDecodeCache[$head4])) {
1243                                 $MPEGaudioHeaderDecodeCache[$head4] = self::MPEGaudioHeaderDecode($head4);
1244                         }
1245                         if (!isset($MPEGaudioHeaderValidCache[$head4])) {
1246                                 $MPEGaudioHeaderValidCache[$head4] = self::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$head4], false, false);
1247                         }
1248                         if ($MPEGaudioHeaderValidCache[$head4]) {
1249
1250                                 if (!isset($MPEGaudioHeaderLengthCache[$head4])) {
1251                                         $LongMPEGversionLookup[$head4]   = $MPEGaudioVersionLookup[$MPEGaudioHeaderDecodeCache[$head4]['version']];
1252                                         $LongMPEGlayerLookup[$head4]     = $MPEGaudioLayerLookup[$MPEGaudioHeaderDecodeCache[$head4]['layer']];
1253                                         $LongMPEGbitrateLookup[$head4]   = $MPEGaudioBitrateLookup[$LongMPEGversionLookup[$head4]][$LongMPEGlayerLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['bitrate']];
1254                                         $LongMPEGpaddingLookup[$head4]   = (bool) $MPEGaudioHeaderDecodeCache[$head4]['padding'];
1255                                         $LongMPEGfrequencyLookup[$head4] = $MPEGaudioFrequencyLookup[$LongMPEGversionLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['sample_rate']];
1256                                         $MPEGaudioHeaderLengthCache[$head4] = self::MPEGaudioFrameLength(
1257                                                 $LongMPEGbitrateLookup[$head4],
1258                                                 $LongMPEGversionLookup[$head4],
1259                                                 $LongMPEGlayerLookup[$head4],
1260                                                 $LongMPEGpaddingLookup[$head4],
1261                                                 $LongMPEGfrequencyLookup[$head4]);
1262                                 }
1263                                 if ($MPEGaudioHeaderLengthCache[$head4] > 4) {
1264                                         $WhereWeWere = $this->ftell();
1265                                         $this->fseek($MPEGaudioHeaderLengthCache[$head4] - 4, SEEK_CUR);
1266                                         $next4 = $this->fread(4);
1267                                         if ($next4{0} == "\xFF") {
1268                                                 if (!isset($MPEGaudioHeaderDecodeCache[$next4])) {
1269                                                         $MPEGaudioHeaderDecodeCache[$next4] = self::MPEGaudioHeaderDecode($next4);
1270                                                 }
1271                                                 if (!isset($MPEGaudioHeaderValidCache[$next4])) {
1272                                                         $MPEGaudioHeaderValidCache[$next4] = self::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$next4], false, false);
1273                                                 }
1274                                                 if ($MPEGaudioHeaderValidCache[$next4]) {
1275                                                         $this->fseek(-4, SEEK_CUR);
1276
1277                                                         getid3_lib::safe_inc($Distribution['bitrate'][$LongMPEGbitrateLookup[$head4]]);
1278                                                         getid3_lib::safe_inc($Distribution['layer'][$LongMPEGlayerLookup[$head4]]);
1279                                                         getid3_lib::safe_inc($Distribution['version'][$LongMPEGversionLookup[$head4]]);
1280                                                         getid3_lib::safe_inc($Distribution['padding'][intval($LongMPEGpaddingLookup[$head4])]);
1281                                                         getid3_lib::safe_inc($Distribution['frequency'][$LongMPEGfrequencyLookup[$head4]]);
1282                                                         if ($max_frames_scan && (++$frames_scanned >= $max_frames_scan)) {
1283                                                                 $pct_data_scanned = ($this->ftell() - $info['avdataoffset']) / ($info['avdataend'] - $info['avdataoffset']);
1284                                                                 $info['warning'][] = 'too many MPEG audio frames to scan, only scanned first '.$max_frames_scan.' frames ('.number_format($pct_data_scanned * 100, 1).'% of file) and extrapolated distribution, playtime and bitrate may be incorrect.';
1285                                                                 foreach ($Distribution as $key1 => $value1) {
1286                                                                         foreach ($value1 as $key2 => $value2) {
1287                                                                                 $Distribution[$key1][$key2] = round($value2 / $pct_data_scanned);
1288                                                                         }
1289                                                                 }
1290                                                                 break;
1291                                                         }
1292                                                         continue;
1293                                                 }
1294                                         }
1295                                         unset($next4);
1296                                         $this->fseek($WhereWeWere - 3);
1297                                 }
1298
1299                         }
1300                 }
1301                 foreach ($Distribution as $key => $value) {
1302                         ksort($Distribution[$key], SORT_NUMERIC);
1303                 }
1304                 ksort($Distribution['version'], SORT_STRING);
1305                 $info['mpeg']['audio']['bitrate_distribution']   = $Distribution['bitrate'];
1306                 $info['mpeg']['audio']['frequency_distribution'] = $Distribution['frequency'];
1307                 $info['mpeg']['audio']['layer_distribution']     = $Distribution['layer'];
1308                 $info['mpeg']['audio']['version_distribution']   = $Distribution['version'];
1309                 $info['mpeg']['audio']['padding_distribution']   = $Distribution['padding'];
1310                 if (count($Distribution['version']) > 1) {
1311                         $info['error'][] = 'Corrupt file - more than one MPEG version detected';
1312                 }
1313                 if (count($Distribution['layer']) > 1) {
1314                         $info['error'][] = 'Corrupt file - more than one MPEG layer detected';
1315                 }
1316                 if (count($Distribution['frequency']) > 1) {
1317                         $info['error'][] = 'Corrupt file - more than one MPEG sample rate detected';
1318                 }
1319
1320
1321                 $bittotal = 0;
1322                 foreach ($Distribution['bitrate'] as $bitratevalue => $bitratecount) {
1323                         if ($bitratevalue != 'free') {
1324                                 $bittotal += ($bitratevalue * $bitratecount);
1325                         }
1326                 }
1327                 $info['mpeg']['audio']['frame_count']  = array_sum($Distribution['bitrate']);
1328                 if ($info['mpeg']['audio']['frame_count'] == 0) {
1329                         $info['error'][] = 'no MPEG audio frames found';
1330                         return false;
1331                 }
1332                 $info['mpeg']['audio']['bitrate']      = ($bittotal / $info['mpeg']['audio']['frame_count']);
1333                 $info['mpeg']['audio']['bitrate_mode'] = ((count($Distribution['bitrate']) > 0) ? 'vbr' : 'cbr');
1334                 $info['mpeg']['audio']['sample_rate']  = getid3_lib::array_max($Distribution['frequency'], true);
1335
1336                 $info['audio']['bitrate']      = $info['mpeg']['audio']['bitrate'];
1337                 $info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
1338                 $info['audio']['sample_rate']  = $info['mpeg']['audio']['sample_rate'];
1339                 $info['audio']['dataformat']   = 'mp'.getid3_lib::array_max($Distribution['layer'], true);
1340                 $info['fileformat']            = $info['audio']['dataformat'];
1341
1342                 return true;
1343         }
1344
1345
1346         public function getOnlyMPEGaudioInfo($avdataoffset, $BitrateHistogram=false) {
1347                 // looks for synch, decodes MPEG audio header
1348
1349                 $info = &$this->getid3->info;
1350
1351                 static $MPEGaudioVersionLookup;
1352                 static $MPEGaudioLayerLookup;
1353                 static $MPEGaudioBitrateLookup;
1354                 if (empty($MPEGaudioVersionLookup)) {
1355                    $MPEGaudioVersionLookup = self::MPEGaudioVersionArray();
1356                    $MPEGaudioLayerLookup   = self::MPEGaudioLayerArray();
1357                    $MPEGaudioBitrateLookup = self::MPEGaudioBitrateArray();
1358
1359                 }
1360
1361                 $this->fseek($avdataoffset);
1362                 $sync_seek_buffer_size = min(128 * 1024, $info['avdataend'] - $avdataoffset);
1363                 if ($sync_seek_buffer_size <= 0) {
1364                         $info['error'][] = 'Invalid $sync_seek_buffer_size at offset '.$avdataoffset;
1365                         return false;
1366                 }
1367                 $header = $this->fread($sync_seek_buffer_size);
1368                 $sync_seek_buffer_size = strlen($header);
1369                 $SynchSeekOffset = 0;
1370                 while ($SynchSeekOffset < $sync_seek_buffer_size) {
1371                         if ((($avdataoffset + $SynchSeekOffset)  < $info['avdataend']) && !feof($this->getid3->fp)) {
1372
1373                                 if ($SynchSeekOffset > $sync_seek_buffer_size) {
1374                                         // if a synch's not found within the first 128k bytes, then give up
1375                                         $info['error'][] = 'Could not find valid MPEG audio synch within the first '.round($sync_seek_buffer_size / 1024).'kB';
1376                                         if (isset($info['audio']['bitrate'])) {
1377                                                 unset($info['audio']['bitrate']);
1378                                         }
1379                                         if (isset($info['mpeg']['audio'])) {
1380                                                 unset($info['mpeg']['audio']);
1381                                         }
1382                                         if (empty($info['mpeg'])) {
1383                                                 unset($info['mpeg']);
1384                                         }
1385                                         return false;
1386
1387                                 } elseif (feof($this->getid3->fp)) {
1388
1389                                         $info['error'][] = 'Could not find valid MPEG audio synch before end of file';
1390                                         if (isset($info['audio']['bitrate'])) {
1391                                                 unset($info['audio']['bitrate']);
1392                                         }
1393                                         if (isset($info['mpeg']['audio'])) {
1394                                                 unset($info['mpeg']['audio']);
1395                                         }
1396                                         if (isset($info['mpeg']) && (!is_array($info['mpeg']) || (count($info['mpeg']) == 0))) {
1397                                                 unset($info['mpeg']);
1398                                         }
1399                                         return false;
1400                                 }
1401                         }
1402
1403                         if (($SynchSeekOffset + 1) >= strlen($header)) {
1404                                 $info['error'][] = 'Could not find valid MPEG synch before end of file';
1405                                 return false;
1406                         }
1407
1408                         if (($header{$SynchSeekOffset} == "\xFF") && ($header{($SynchSeekOffset + 1)} > "\xE0")) { // synch detected
1409                                 if (!isset($FirstFrameThisfileInfo) && !isset($info['mpeg']['audio'])) {
1410                                         $FirstFrameThisfileInfo = $info;
1411                                         $FirstFrameAVDataOffset = $avdataoffset + $SynchSeekOffset;
1412                                         if (!$this->decodeMPEGaudioHeader($FirstFrameAVDataOffset, $FirstFrameThisfileInfo, false)) {
1413                                                 // if this is the first valid MPEG-audio frame, save it in case it's a VBR header frame and there's
1414                                                 // garbage between this frame and a valid sequence of MPEG-audio frames, to be restored below
1415                                                 unset($FirstFrameThisfileInfo);
1416                                         }
1417                                 }
1418
1419                                 $dummy = $info; // only overwrite real data if valid header found
1420                                 if ($this->decodeMPEGaudioHeader($avdataoffset + $SynchSeekOffset, $dummy, true)) {
1421                                         $info = $dummy;
1422                                         $info['avdataoffset'] = $avdataoffset + $SynchSeekOffset;
1423                                         switch (isset($info['fileformat']) ? $info['fileformat'] : '') {
1424                                                 case '':
1425                                                 case 'id3':
1426                                                 case 'ape':
1427                                                 case 'mp3':
1428                                                         $info['fileformat']          = 'mp3';
1429                                                         $info['audio']['dataformat'] = 'mp3';
1430                                                         break;
1431                                         }
1432                                         if (isset($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode']) && ($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode'] == 'vbr')) {
1433                                                 if (!(abs($info['audio']['bitrate'] - $FirstFrameThisfileInfo['audio']['bitrate']) <= 1)) {
1434                                                         // If there is garbage data between a valid VBR header frame and a sequence
1435                                                         // of valid MPEG-audio frames the VBR data is no longer discarded.
1436                                                         $info = $FirstFrameThisfileInfo;
1437                                                         $info['avdataoffset']        = $FirstFrameAVDataOffset;
1438                                                         $info['fileformat']          = 'mp3';
1439                                                         $info['audio']['dataformat'] = 'mp3';
1440                                                         $dummy                       = $info;
1441                                                         unset($dummy['mpeg']['audio']);
1442                                                         $GarbageOffsetStart = $FirstFrameAVDataOffset + $FirstFrameThisfileInfo['mpeg']['audio']['framelength'];
1443                                                         $GarbageOffsetEnd   = $avdataoffset + $SynchSeekOffset;
1444                                                         if ($this->decodeMPEGaudioHeader($GarbageOffsetEnd, $dummy, true, true)) {
1445                                                                 $info = $dummy;
1446                                                                 $info['avdataoffset'] = $GarbageOffsetEnd;
1447                                                                 $info['warning'][] = 'apparently-valid VBR header not used because could not find '.GETID3_MP3_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.'), but did find valid CBR stream starting at '.$GarbageOffsetEnd;
1448                                                         } else {
1449                                                                 $info['warning'][] = 'using data from VBR header even though could not find '.GETID3_MP3_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.')';
1450                                                         }
1451                                                 }
1452                                         }
1453                                         if (isset($info['mpeg']['audio']['bitrate_mode']) && ($info['mpeg']['audio']['bitrate_mode'] == 'vbr') && !isset($info['mpeg']['audio']['VBR_method'])) {
1454                                                 // VBR file with no VBR header
1455                                                 $BitrateHistogram = true;
1456                                         }
1457
1458                                         if ($BitrateHistogram) {
1459
1460                                                 $info['mpeg']['audio']['stereo_distribution']  = array('stereo'=>0, 'joint stereo'=>0, 'dual channel'=>0, 'mono'=>0);
1461                                                 $info['mpeg']['audio']['version_distribution'] = array('1'=>0, '2'=>0, '2.5'=>0);
1462
1463                                                 if ($info['mpeg']['audio']['version'] == '1') {
1464                                                         if ($info['mpeg']['audio']['layer'] == 3) {
1465                                                                 $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 40000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 320000=>0);
1466                                                         } elseif ($info['mpeg']['audio']['layer'] == 2) {
1467                                                                 $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 320000=>0, 384000=>0);
1468                                                         } elseif ($info['mpeg']['audio']['layer'] == 1) {
1469                                                                 $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 64000=>0, 96000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 288000=>0, 320000=>0, 352000=>0, 384000=>0, 416000=>0, 448000=>0);
1470                                                         }
1471                                                 } elseif ($info['mpeg']['audio']['layer'] == 1) {
1472                                                         $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);
1473                                                 } else {
1474                                                         $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);
1475                                                 }
1476
1477                                                 $dummy = array('error'=>$info['error'], 'warning'=>$info['warning'], 'avdataend'=>$info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1478                                                 $synchstartoffset = $info['avdataoffset'];
1479                                                 $this->fseek($info['avdataoffset']);
1480
1481                                                 // you can play with these numbers:
1482                                                 $max_frames_scan  = 50000;
1483                                                 $max_scan_segments = 10;
1484
1485                                                 // don't play with these numbers:
1486                                                 $FastMode = false;
1487                                                 $SynchErrorsFound = 0;
1488                                                 $frames_scanned   = 0;
1489                                                 $this_scan_segment = 0;
1490                                                 $frames_scan_per_segment = ceil($max_frames_scan / $max_scan_segments);
1491                                                 $pct_data_scanned = 0;
1492                                                 for ($current_segment = 0; $current_segment < $max_scan_segments; $current_segment++) {
1493                                                         $frames_scanned_this_segment = 0;
1494                                                         if ($this->ftell() >= $info['avdataend']) {
1495                                                                 break;
1496                                                         }
1497                                                         $scan_start_offset[$current_segment] = max($this->ftell(), $info['avdataoffset'] + round($current_segment * (($info['avdataend'] - $info['avdataoffset']) / $max_scan_segments)));
1498                                                         if ($current_segment > 0) {
1499                                                                 $this->fseek($scan_start_offset[$current_segment]);
1500                                                                 $buffer_4k = $this->fread(4096);
1501                                                                 for ($j = 0; $j < (strlen($buffer_4k) - 4); $j++) {
1502                                                                         if (($buffer_4k{$j} == "\xFF") && ($buffer_4k{($j + 1)} > "\xE0")) { // synch detected
1503                                                                                 if ($this->decodeMPEGaudioHeader($scan_start_offset[$current_segment] + $j, $dummy, false, false, $FastMode)) {
1504                                                                                         $calculated_next_offset = $scan_start_offset[$current_segment] + $j + $dummy['mpeg']['audio']['framelength'];
1505                                                                                         if ($this->decodeMPEGaudioHeader($calculated_next_offset, $dummy, false, false, $FastMode)) {
1506                                                                                                 $scan_start_offset[$current_segment] += $j;
1507                                                                                                 break;
1508                                                                                         }
1509                                                                                 }
1510                                                                         }
1511                                                                 }
1512                                                         }
1513                                                         $synchstartoffset = $scan_start_offset[$current_segment];
1514                                                         while ($this->decodeMPEGaudioHeader($synchstartoffset, $dummy, false, false, $FastMode)) {
1515                                                                 $FastMode = true;
1516                                                                 $thisframebitrate = $MPEGaudioBitrateLookup[$MPEGaudioVersionLookup[$dummy['mpeg']['audio']['raw']['version']]][$MPEGaudioLayerLookup[$dummy['mpeg']['audio']['raw']['layer']]][$dummy['mpeg']['audio']['raw']['bitrate']];
1517
1518                                                                 if (empty($dummy['mpeg']['audio']['framelength'])) {
1519                                                                         $SynchErrorsFound++;
1520                                                                         $synchstartoffset++;
1521                                                                 } else {
1522                                                                         getid3_lib::safe_inc($info['mpeg']['audio']['bitrate_distribution'][$thisframebitrate]);
1523                                                                         getid3_lib::safe_inc($info['mpeg']['audio']['stereo_distribution'][$dummy['mpeg']['audio']['channelmode']]);
1524                                                                         getid3_lib::safe_inc($info['mpeg']['audio']['version_distribution'][$dummy['mpeg']['audio']['version']]);
1525                                                                         $synchstartoffset += $dummy['mpeg']['audio']['framelength'];
1526                                                                 }
1527                                                                 $frames_scanned++;
1528                                                                 if ($frames_scan_per_segment && (++$frames_scanned_this_segment >= $frames_scan_per_segment)) {
1529                                                                         $this_pct_scanned = ($this->ftell() - $scan_start_offset[$current_segment]) / ($info['avdataend'] - $info['avdataoffset']);
1530                                                                         if (($current_segment == 0) && (($this_pct_scanned * $max_scan_segments) >= 1)) {
1531                                                                                 // file likely contains < $max_frames_scan, just scan as one segment
1532                                                                                 $max_scan_segments = 1;
1533                                                                                 $frames_scan_per_segment = $max_frames_scan;
1534                                                                         } else {
1535                                                                                 $pct_data_scanned += $this_pct_scanned;
1536                                                                                 break;
1537                                                                         }
1538                                                                 }
1539                                                         }
1540                                                 }
1541                                                 if ($pct_data_scanned > 0) {
1542                                                         $info['warning'][] = 'too many MPEG audio frames to scan, only scanned '.$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.';
1543                                                         foreach ($info['mpeg']['audio'] as $key1 => $value1) {
1544                                                                 if (!preg_match('#_distribution$#i', $key1)) {
1545                                                                         continue;
1546                                                                 }
1547                                                                 foreach ($value1 as $key2 => $value2) {
1548                                                                         $info['mpeg']['audio'][$key1][$key2] = round($value2 / $pct_data_scanned);
1549                                                                 }
1550                                                         }
1551                                                 }
1552
1553                                                 if ($SynchErrorsFound > 0) {
1554                                                         $info['warning'][] = 'Found '.$SynchErrorsFound.' synch errors in histogram analysis';
1555                                                         //return false;
1556                                                 }
1557
1558                                                 $bittotal     = 0;
1559                                                 $framecounter = 0;
1560                                                 foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitratevalue => $bitratecount) {
1561                                                         $framecounter += $bitratecount;
1562                                                         if ($bitratevalue != 'free') {
1563                                                                 $bittotal += ($bitratevalue * $bitratecount);
1564                                                         }
1565                                                 }
1566                                                 if ($framecounter == 0) {
1567                                                         $info['error'][] = 'Corrupt MP3 file: framecounter == zero';
1568                                                         return false;
1569                                                 }
1570                                                 $info['mpeg']['audio']['frame_count'] = getid3_lib::CastAsInt($framecounter);
1571                                                 $info['mpeg']['audio']['bitrate']     = ($bittotal / $framecounter);
1572
1573                                                 $info['audio']['bitrate'] = $info['mpeg']['audio']['bitrate'];
1574
1575
1576                                                 // Definitively set VBR vs CBR, even if the Xing/LAME/VBRI header says differently
1577                                                 $distinct_bitrates = 0;
1578                                                 foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitrate_value => $bitrate_count) {
1579                                                         if ($bitrate_count > 0) {
1580                                                                 $distinct_bitrates++;
1581                                                         }
1582                                                 }
1583                                                 if ($distinct_bitrates > 1) {
1584                                                         $info['mpeg']['audio']['bitrate_mode'] = 'vbr';
1585                                                 } else {
1586                                                         $info['mpeg']['audio']['bitrate_mode'] = 'cbr';
1587                                                 }
1588                                                 $info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
1589
1590                                         }
1591
1592                                         break; // exit while()
1593                                 }
1594                         }
1595
1596                         $SynchSeekOffset++;
1597                         if (($avdataoffset + $SynchSeekOffset) >= $info['avdataend']) {
1598                                 // end of file/data
1599
1600                                 if (empty($info['mpeg']['audio'])) {
1601
1602                                         $info['error'][] = 'could not find valid MPEG synch before end of file';
1603                                         if (isset($info['audio']['bitrate'])) {
1604                                                 unset($info['audio']['bitrate']);
1605                                         }
1606                                         if (isset($info['mpeg']['audio'])) {
1607                                                 unset($info['mpeg']['audio']);
1608                                         }
1609                                         if (isset($info['mpeg']) && (!is_array($info['mpeg']) || empty($info['mpeg']))) {
1610                                                 unset($info['mpeg']);
1611                                         }
1612                                         return false;
1613
1614                                 }
1615                                 break;
1616                         }
1617
1618                 }
1619                 $info['audio']['channels']        = $info['mpeg']['audio']['channels'];
1620                 $info['audio']['channelmode']     = $info['mpeg']['audio']['channelmode'];
1621                 $info['audio']['sample_rate']     = $info['mpeg']['audio']['sample_rate'];
1622                 return true;
1623         }
1624
1625
1626         public static function MPEGaudioVersionArray() {
1627                 static $MPEGaudioVersion = array('2.5', false, '2', '1');
1628                 return $MPEGaudioVersion;
1629         }
1630
1631         public static function MPEGaudioLayerArray() {
1632                 static $MPEGaudioLayer = array(false, 3, 2, 1);
1633                 return $MPEGaudioLayer;
1634         }
1635
1636         public static function MPEGaudioBitrateArray() {
1637                 static $MPEGaudioBitrate;
1638                 if (empty($MPEGaudioBitrate)) {
1639                         $MPEGaudioBitrate = array (
1640                                 '1'  =>  array (1 => array('free', 32000, 64000, 96000, 128000, 160000, 192000, 224000, 256000, 288000, 320000, 352000, 384000, 416000, 448000),
1641                                                                 2 => array('free', 32000, 48000, 56000,  64000,  80000,  96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000, 384000),
1642                                                                 3 => array('free', 32000, 40000, 48000,  56000,  64000,  80000,  96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000)
1643                                                            ),
1644
1645                                 '2'  =>  array (1 => array('free', 32000, 48000, 56000,  64000,  80000,  96000, 112000, 128000, 144000, 160000, 176000, 192000, 224000, 256000),
1646                                                                 2 => array('free',  8000, 16000, 24000,  32000,  40000,  48000,  56000,  64000,  80000,  96000, 112000, 128000, 144000, 160000),
1647                                                            )
1648                         );
1649                         $MPEGaudioBitrate['2'][3] = $MPEGaudioBitrate['2'][2];
1650                         $MPEGaudioBitrate['2.5']  = $MPEGaudioBitrate['2'];
1651                 }
1652                 return $MPEGaudioBitrate;
1653         }
1654
1655         public static function MPEGaudioFrequencyArray() {
1656                 static $MPEGaudioFrequency;
1657                 if (empty($MPEGaudioFrequency)) {
1658                         $MPEGaudioFrequency = array (
1659                                 '1'   => array(44100, 48000, 32000),
1660                                 '2'   => array(22050, 24000, 16000),
1661                                 '2.5' => array(11025, 12000,  8000)
1662                         );
1663                 }
1664                 return $MPEGaudioFrequency;
1665         }
1666
1667         public static function MPEGaudioChannelModeArray() {
1668                 static $MPEGaudioChannelMode = array('stereo', 'joint stereo', 'dual channel', 'mono');
1669                 return $MPEGaudioChannelMode;
1670         }
1671
1672         public static function MPEGaudioModeExtensionArray() {
1673                 static $MPEGaudioModeExtension;
1674                 if (empty($MPEGaudioModeExtension)) {
1675                         $MPEGaudioModeExtension = array (
1676                                 1 => array('4-31', '8-31', '12-31', '16-31'),
1677                                 2 => array('4-31', '8-31', '12-31', '16-31'),
1678                                 3 => array('', 'IS', 'MS', 'IS+MS')
1679                         );
1680                 }
1681                 return $MPEGaudioModeExtension;
1682         }
1683
1684         public static function MPEGaudioEmphasisArray() {
1685                 static $MPEGaudioEmphasis = array('none', '50/15ms', false, 'CCIT J.17');
1686                 return $MPEGaudioEmphasis;
1687         }
1688
1689         public static function MPEGaudioHeaderBytesValid($head4, $allowBitrate15=false) {
1690                 return self::MPEGaudioHeaderValid(self::MPEGaudioHeaderDecode($head4), false, $allowBitrate15);
1691         }
1692
1693         public static function MPEGaudioHeaderValid($rawarray, $echoerrors=false, $allowBitrate15=false) {
1694                 if (($rawarray['synch'] & 0x0FFE) != 0x0FFE) {
1695                         return false;
1696                 }
1697
1698                 static $MPEGaudioVersionLookup;
1699                 static $MPEGaudioLayerLookup;
1700                 static $MPEGaudioBitrateLookup;
1701                 static $MPEGaudioFrequencyLookup;
1702                 static $MPEGaudioChannelModeLookup;
1703                 static $MPEGaudioModeExtensionLookup;
1704                 static $MPEGaudioEmphasisLookup;
1705                 if (empty($MPEGaudioVersionLookup)) {
1706                         $MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();
1707                         $MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();
1708                         $MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();
1709                         $MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();
1710                         $MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();
1711                         $MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
1712                         $MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();
1713                 }
1714
1715                 if (isset($MPEGaudioVersionLookup[$rawarray['version']])) {
1716                         $decodedVersion = $MPEGaudioVersionLookup[$rawarray['version']];
1717                 } else {
1718                         echo ($echoerrors ? "\n".'invalid Version ('.$rawarray['version'].')' : '');
1719                         return false;
1720                 }
1721                 if (isset($MPEGaudioLayerLookup[$rawarray['layer']])) {
1722                         $decodedLayer = $MPEGaudioLayerLookup[$rawarray['layer']];
1723                 } else {
1724                         echo ($echoerrors ? "\n".'invalid Layer ('.$rawarray['layer'].')' : '');
1725                         return false;
1726                 }
1727                 if (!isset($MPEGaudioBitrateLookup[$decodedVersion][$decodedLayer][$rawarray['bitrate']])) {
1728                         echo ($echoerrors ? "\n".'invalid Bitrate ('.$rawarray['bitrate'].')' : '');
1729                         if ($rawarray['bitrate'] == 15) {
1730                                 // known issue in LAME 3.90 - 3.93.1 where free-format has bitrate ID of 15 instead of 0
1731                                 // let it go through here otherwise file will not be identified
1732                                 if (!$allowBitrate15) {
1733                                         return false;
1734                                 }
1735                         } else {
1736                                 return false;
1737                         }
1738                 }
1739                 if (!isset($MPEGaudioFrequencyLookup[$decodedVersion][$rawarray['sample_rate']])) {
1740                         echo ($echoerrors ? "\n".'invalid Frequency ('.$rawarray['sample_rate'].')' : '');
1741                         return false;
1742                 }
1743                 if (!isset($MPEGaudioChannelModeLookup[$rawarray['channelmode']])) {
1744                         echo ($echoerrors ? "\n".'invalid ChannelMode ('.$rawarray['channelmode'].')' : '');
1745                         return false;
1746                 }
1747                 if (!isset($MPEGaudioModeExtensionLookup[$decodedLayer][$rawarray['modeextension']])) {
1748                         echo ($echoerrors ? "\n".'invalid Mode Extension ('.$rawarray['modeextension'].')' : '');
1749                         return false;
1750                 }
1751                 if (!isset($MPEGaudioEmphasisLookup[$rawarray['emphasis']])) {
1752                         echo ($echoerrors ? "\n".'invalid Emphasis ('.$rawarray['emphasis'].')' : '');
1753                         return false;
1754                 }
1755                 // These are just either set or not set, you can't mess that up :)
1756                 // $rawarray['protection'];
1757                 // $rawarray['padding'];
1758                 // $rawarray['private'];
1759                 // $rawarray['copyright'];
1760                 // $rawarray['original'];
1761
1762                 return true;
1763         }
1764
1765         public static function MPEGaudioHeaderDecode($Header4Bytes) {
1766                 // AAAA AAAA  AAAB BCCD  EEEE FFGH  IIJJ KLMM
1767                 // A - Frame sync (all bits set)
1768                 // B - MPEG Audio version ID
1769                 // C - Layer description
1770                 // D - Protection bit
1771                 // E - Bitrate index
1772                 // F - Sampling rate frequency index
1773                 // G - Padding bit
1774                 // H - Private bit
1775                 // I - Channel Mode
1776                 // J - Mode extension (Only if Joint stereo)
1777                 // K - Copyright
1778                 // L - Original
1779                 // M - Emphasis
1780
1781                 if (strlen($Header4Bytes) != 4) {
1782                         return false;
1783                 }
1784
1785                 $MPEGrawHeader['synch']         = (getid3_lib::BigEndian2Int(substr($Header4Bytes, 0, 2)) & 0xFFE0) >> 4;
1786                 $MPEGrawHeader['version']       = (ord($Header4Bytes{1}) & 0x18) >> 3; //    BB
1787                 $MPEGrawHeader['layer']         = (ord($Header4Bytes{1}) & 0x06) >> 1; //      CC
1788                 $MPEGrawHeader['protection']    = (ord($Header4Bytes{1}) & 0x01);      //        D
1789                 $MPEGrawHeader['bitrate']       = (ord($Header4Bytes{2}) & 0xF0) >> 4; // EEEE
1790                 $MPEGrawHeader['sample_rate']   = (ord($Header4Bytes{2}) & 0x0C) >> 2; //     FF
1791                 $MPEGrawHeader['padding']       = (ord($Header4Bytes{2}) & 0x02) >> 1; //       G
1792                 $MPEGrawHeader['private']       = (ord($Header4Bytes{2}) & 0x01);      //        H
1793                 $MPEGrawHeader['channelmode']   = (ord($Header4Bytes{3}) & 0xC0) >> 6; // II
1794                 $MPEGrawHeader['modeextension'] = (ord($Header4Bytes{3}) & 0x30) >> 4; //   JJ
1795                 $MPEGrawHeader['copyright']     = (ord($Header4Bytes{3}) & 0x08) >> 3; //     K
1796                 $MPEGrawHeader['original']      = (ord($Header4Bytes{3}) & 0x04) >> 2; //      L
1797                 $MPEGrawHeader['emphasis']      = (ord($Header4Bytes{3}) & 0x03);      //       MM
1798
1799                 return $MPEGrawHeader;
1800         }
1801
1802         public static function MPEGaudioFrameLength(&$bitrate, &$version, &$layer, $padding, &$samplerate) {
1803                 static $AudioFrameLengthCache = array();
1804
1805                 if (!isset($AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate])) {
1806                         $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = false;
1807                         if ($bitrate != 'free') {
1808
1809                                 if ($version == '1') {
1810
1811                                         if ($layer == '1') {
1812
1813                                                 // For Layer I slot is 32 bits long
1814                                                 $FrameLengthCoefficient = 48;
1815                                                 $SlotLength = 4;
1816
1817                                         } else { // Layer 2 / 3
1818
1819                                                 // for Layer 2 and Layer 3 slot is 8 bits long.
1820                                                 $FrameLengthCoefficient = 144;
1821                                                 $SlotLength = 1;
1822
1823                                         }
1824
1825                                 } else { // MPEG-2 / MPEG-2.5
1826
1827                                         if ($layer == '1') {
1828
1829                                                 // For Layer I slot is 32 bits long
1830                                                 $FrameLengthCoefficient = 24;
1831                                                 $SlotLength = 4;
1832
1833                                         } elseif ($layer == '2') {
1834
1835                                                 // for Layer 2 and Layer 3 slot is 8 bits long.
1836                                                 $FrameLengthCoefficient = 144;
1837                                                 $SlotLength = 1;
1838
1839                                         } else { // layer 3
1840
1841                                                 // for Layer 2 and Layer 3 slot is 8 bits long.
1842                                                 $FrameLengthCoefficient = 72;
1843                                                 $SlotLength = 1;
1844
1845                                         }
1846
1847                                 }
1848
1849                                 // FrameLengthInBytes = ((Coefficient * BitRate) / SampleRate) + Padding
1850                                 if ($samplerate > 0) {
1851                                         $NewFramelength  = ($FrameLengthCoefficient * $bitrate) / $samplerate;
1852                                         $NewFramelength  = floor($NewFramelength / $SlotLength) * $SlotLength; // round to next-lower multiple of SlotLength (1 byte for Layer 2/3, 4 bytes for Layer I)
1853                                         if ($padding) {
1854                                                 $NewFramelength += $SlotLength;
1855                                         }
1856                                         $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = (int) $NewFramelength;
1857                                 }
1858                         }
1859                 }
1860                 return $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate];
1861         }
1862
1863         public static function ClosestStandardMP3Bitrate($bit_rate) {
1864                 static $standard_bit_rates = array (320000, 256000, 224000, 192000, 160000, 128000, 112000, 96000, 80000, 64000, 56000, 48000, 40000, 32000, 24000, 16000, 8000);
1865                 static $bit_rate_table = array (0=>'-');
1866                 $round_bit_rate = intval(round($bit_rate, -3));
1867                 if (!isset($bit_rate_table[$round_bit_rate])) {
1868                         if ($round_bit_rate > max($standard_bit_rates)) {
1869                                 $bit_rate_table[$round_bit_rate] = round($bit_rate, 2 - strlen($bit_rate));
1870                         } else {
1871                                 $bit_rate_table[$round_bit_rate] = max($standard_bit_rates);
1872                                 foreach ($standard_bit_rates as $standard_bit_rate) {
1873                                         if ($round_bit_rate >= $standard_bit_rate + (($bit_rate_table[$round_bit_rate] - $standard_bit_rate) / 2)) {
1874                                                 break;
1875                                         }
1876                                         $bit_rate_table[$round_bit_rate] = $standard_bit_rate;
1877                                 }
1878                         }
1879                 }
1880                 return $bit_rate_table[$round_bit_rate];
1881         }
1882
1883         public static function XingVBRidOffset($version, $channelmode) {
1884                 static $XingVBRidOffsetCache = array();
1885                 if (empty($XingVBRidOffset)) {
1886                         $XingVBRidOffset = array (
1887                                 '1'   => array ('mono'          => 0x15, // 4 + 17 = 21
1888                                                                 'stereo'        => 0x24, // 4 + 32 = 36
1889                                                                 'joint stereo'  => 0x24,
1890                                                                 'dual channel'  => 0x24
1891                                                            ),
1892
1893                                 '2'   => array ('mono'          => 0x0D, // 4 +  9 = 13
1894                                                                 'stereo'        => 0x15, // 4 + 17 = 21
1895                                                                 'joint stereo'  => 0x15,
1896                                                                 'dual channel'  => 0x15
1897                                                            ),
1898
1899                                 '2.5' => array ('mono'          => 0x15,
1900                                                                 'stereo'        => 0x15,
1901                                                                 'joint stereo'  => 0x15,
1902                                                                 'dual channel'  => 0x15
1903                                                            )
1904                         );
1905                 }
1906                 return $XingVBRidOffset[$version][$channelmode];
1907         }
1908
1909         public static function LAMEvbrMethodLookup($VBRmethodID) {
1910                 static $LAMEvbrMethodLookup = array(
1911                         0x00 => 'unknown',
1912                         0x01 => 'cbr',
1913                         0x02 => 'abr',
1914                         0x03 => 'vbr-old / vbr-rh',
1915                         0x04 => 'vbr-new / vbr-mtrh',
1916                         0x05 => 'vbr-mt',
1917                         0x06 => 'vbr (full vbr method 4)',
1918                         0x08 => 'cbr (constant bitrate 2 pass)',
1919                         0x09 => 'abr (2 pass)',
1920                         0x0F => 'reserved'
1921                 );
1922                 return (isset($LAMEvbrMethodLookup[$VBRmethodID]) ? $LAMEvbrMethodLookup[$VBRmethodID] : '');
1923         }
1924
1925         public static function LAMEmiscStereoModeLookup($StereoModeID) {
1926                 static $LAMEmiscStereoModeLookup = array(
1927                         0 => 'mono',
1928                         1 => 'stereo',
1929                         2 => 'dual mono',
1930                         3 => 'joint stereo',
1931                         4 => 'forced stereo',
1932                         5 => 'auto',
1933                         6 => 'intensity stereo',
1934                         7 => 'other'
1935                 );
1936                 return (isset($LAMEmiscStereoModeLookup[$StereoModeID]) ? $LAMEmiscStereoModeLookup[$StereoModeID] : '');
1937         }
1938
1939         public static function LAMEmiscSourceSampleFrequencyLookup($SourceSampleFrequencyID) {
1940                 static $LAMEmiscSourceSampleFrequencyLookup = array(
1941                         0 => '<= 32 kHz',
1942                         1 => '44.1 kHz',
1943                         2 => '48 kHz',
1944                         3 => '> 48kHz'
1945                 );
1946                 return (isset($LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID]) ? $LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID] : '');
1947         }
1948
1949         public static function LAMEsurroundInfoLookup($SurroundInfoID) {
1950                 static $LAMEsurroundInfoLookup = array(
1951                         0 => 'no surround info',
1952                         1 => 'DPL encoding',
1953                         2 => 'DPL2 encoding',
1954                         3 => 'Ambisonic encoding'
1955                 );
1956                 return (isset($LAMEsurroundInfoLookup[$SurroundInfoID]) ? $LAMEsurroundInfoLookup[$SurroundInfoID] : 'reserved');
1957         }
1958
1959         public static function LAMEpresetUsedLookup($LAMEtag) {
1960
1961                 if ($LAMEtag['preset_used_id'] == 0) {
1962                         // no preset used (LAME >=3.93)
1963                         // no preset recorded (LAME <3.93)
1964                         return '';
1965                 }
1966                 $LAMEpresetUsedLookup = array();
1967
1968                 /////  THIS PART CANNOT BE STATIC .
1969                 for ($i = 8; $i <= 320; $i++) {
1970                         switch ($LAMEtag['vbr_method']) {
1971                                 case 'cbr':
1972                                         $LAMEpresetUsedLookup[$i] = '--alt-preset '.$LAMEtag['vbr_method'].' '.$i;
1973                                         break;
1974                                 case 'abr':
1975                                 default: // other VBR modes shouldn't be here(?)
1976                                         $LAMEpresetUsedLookup[$i] = '--alt-preset '.$i;
1977                                         break;
1978                         }
1979                 }
1980
1981                 // named old-style presets (studio, phone, voice, etc) are handled in GuessEncoderOptions()
1982
1983                 // named alt-presets
1984                 $LAMEpresetUsedLookup[1000] = '--r3mix';
1985                 $LAMEpresetUsedLookup[1001] = '--alt-preset standard';
1986                 $LAMEpresetUsedLookup[1002] = '--alt-preset extreme';
1987                 $LAMEpresetUsedLookup[1003] = '--alt-preset insane';
1988                 $LAMEpresetUsedLookup[1004] = '--alt-preset fast standard';
1989                 $LAMEpresetUsedLookup[1005] = '--alt-preset fast extreme';
1990                 $LAMEpresetUsedLookup[1006] = '--alt-preset medium';
1991                 $LAMEpresetUsedLookup[1007] = '--alt-preset fast medium';
1992
1993                 // LAME 3.94 additions/changes
1994                 $LAMEpresetUsedLookup[1010] = '--preset portable';                                                           // 3.94a15 Oct 21 2003
1995                 $LAMEpresetUsedLookup[1015] = '--preset radio';                                                              // 3.94a15 Oct 21 2003
1996
1997                 $LAMEpresetUsedLookup[320]  = '--preset insane';                                                             // 3.94a15 Nov 12 2003
1998                 $LAMEpresetUsedLookup[410]  = '-V9';
1999                 $LAMEpresetUsedLookup[420]  = '-V8';
2000                 $LAMEpresetUsedLookup[440]  = '-V6';
2001                 $LAMEpresetUsedLookup[430]  = '--preset radio';                                                              // 3.94a15 Nov 12 2003
2002                 $LAMEpresetUsedLookup[450]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'portable';  // 3.94a15 Nov 12 2003
2003                 $LAMEpresetUsedLookup[460]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'medium';    // 3.94a15 Nov 12 2003
2004                 $LAMEpresetUsedLookup[470]  = '--r3mix';                                                                     // 3.94b1  Dec 18 2003
2005                 $LAMEpresetUsedLookup[480]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'standard';  // 3.94a15 Nov 12 2003
2006                 $LAMEpresetUsedLookup[490]  = '-V1';
2007                 $LAMEpresetUsedLookup[500]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'extreme';   // 3.94a15 Nov 12 2003
2008
2009                 return (isset($LAMEpresetUsedLookup[$LAMEtag['preset_used_id']]) ? $LAMEpresetUsedLookup[$LAMEtag['preset_used_id']] : 'new/unknown preset: '.$LAMEtag['preset_used_id'].' - report to info@getid3.org');
2010         }
2011
2012 }