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module.audio.mpc.php
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1 <?php
4 // available at http://getid3.sourceforge.net //
5 // or http://www.getid3.org //
7 // See readme.txt for more details //
9 // //
10 // module.audio.mpc.php //
11 // module for analyzing Musepack/MPEG+ Audio files //
12 // dependencies: NONE //
13 // ///
15 
16 
17 class getid3_mpc
18 {
19 
20  function getid3_mpc(&$fd, &$ThisFileInfo) {
21  // http://www.uni-jena.de/~pfk/mpp/sv8/header.html
22 
23  $ThisFileInfo['mpc']['header'] = array();
24  $thisfile_mpc_header = &$ThisFileInfo['mpc']['header'];
25 
26  $ThisFileInfo['fileformat'] = 'mpc';
27  $ThisFileInfo['audio']['dataformat'] = 'mpc';
28  $ThisFileInfo['audio']['bitrate_mode'] = 'vbr';
29  $ThisFileInfo['audio']['channels'] = 2; // the format appears to be hardcoded for stereo only
30  $ThisFileInfo['audio']['lossless'] = false;
31 
32  fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);
33 
34  $thisfile_mpc_header['size'] = 28;
35  $MPCheaderData = fread($fd, $thisfile_mpc_header['size']);
36  $offset = 0;
37 
38  if (substr($MPCheaderData, $offset, 3) == 'MP+') {
39 
40  // great, this is SV7+
41  $thisfile_mpc_header['raw']['preamble'] = substr($MPCheaderData, $offset, 3); // should be 'MP+'
42  $offset += 3;
43 
44  } elseif (preg_match('/^[\x00\x01\x10\x11\x40\x41\x50\x51\x80\x81\x90\x91\xC0\xC1\xD0\xD1][\x20-37][\x00\x20\x40\x60\x80\xA0\xC0\xE0]/s', substr($MPCheaderData, 0, 4))) {
45 
46  // this is SV4 - SV6, handle seperately
47  $thisfile_mpc_header['size'] = 8;
48 
49  // add size of file header to avdataoffset - calc bitrate correctly + MD5 data
50  $ThisFileInfo['avdataoffset'] += $thisfile_mpc_header['size'];
51 
52  // Most of this code adapted from Jurgen Faul's MPEGplus source code - thanks Jurgen! :)
53  $HeaderDWORD[0] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 0, 4));
54  $HeaderDWORD[1] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 4, 4));
55 
56 
57  // DDDD DDDD CCCC CCCC BBBB BBBB AAAA AAAA
58  // aaaa aaaa abcd dddd dddd deee eeff ffff
59  //
60  // a = bitrate = anything
61  // b = IS = anything
62  // c = MS = anything
63  // d = streamversion = 0000000004 or 0000000005 or 0000000006
64  // e = maxband = anything
65  // f = blocksize = 000001 for SV5+, anything(?) for SV4
66 
67  $thisfile_mpc_header['target_bitrate'] = (($HeaderDWORD[0] & 0xFF800000) >> 23);
68  $thisfile_mpc_header['intensity_stereo'] = (bool) (($HeaderDWORD[0] & 0x00400000) >> 22);
69  $thisfile_mpc_header['mid-side_stereo'] = (bool) (($HeaderDWORD[0] & 0x00200000) >> 21);
70  $thisfile_mpc_header['stream_major_version'] = ($HeaderDWORD[0] & 0x001FF800) >> 11;
71  $thisfile_mpc_header['stream_minor_version'] = 0; // no sub-version numbers before SV7
72  $thisfile_mpc_header['max_band'] = ($HeaderDWORD[0] & 0x000007C0) >> 6; // related to lowpass frequency, not sure how it translates exactly
73  $thisfile_mpc_header['block_size'] = ($HeaderDWORD[0] & 0x0000003F);
74 
75  switch ($thisfile_mpc_header['stream_major_version']) {
76  case 4:
77  $thisfile_mpc_header['frame_count'] = ($HeaderDWORD[1] >> 16);
78  break;
79 
80  case 5:
81  case 6:
82  $thisfile_mpc_header['frame_count'] = $HeaderDWORD[1];
83  break;
84 
85  default:
86  $ThisFileInfo['error'] = 'Expecting 4, 5 or 6 in version field, found '.$thisfile_mpc_header['stream_major_version'].' instead';
87  unset($ThisFileInfo['mpc']);
88  return false;
89  break;
90  }
91 
92  if (($thisfile_mpc_header['stream_major_version'] > 4) && ($thisfile_mpc_header['block_size'] != 1)) {
93  $ThisFileInfo['warning'][] = 'Block size expected to be 1, actual value found: '.$thisfile_mpc_header['block_size'];
94  }
95 
96  $thisfile_mpc_header['sample_rate'] = 44100; // AB: used by all files up to SV7
97  $ThisFileInfo['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate'];
98  $thisfile_mpc_header['samples'] = $thisfile_mpc_header['frame_count'] * 1152 * $ThisFileInfo['audio']['channels'];
99 
100  if ($thisfile_mpc_header['target_bitrate'] == 0) {
101  $ThisFileInfo['audio']['bitrate_mode'] = 'vbr';
102  } else {
103  $ThisFileInfo['audio']['bitrate_mode'] = 'cbr';
104  }
105 
106  $ThisFileInfo['mpc']['bitrate'] = ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8 * 44100 / $thisfile_mpc_header['frame_count'] / 1152;
107  $ThisFileInfo['audio']['bitrate'] = $ThisFileInfo['mpc']['bitrate'];
108  $ThisFileInfo['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_major_version'];
109 
110  return true;
111 
112  } else {
113 
114  $ThisFileInfo['error'][] = 'Expecting "MP+" at offset '.$ThisFileInfo['avdataoffset'].', found "'.substr($MPCheaderData, $offset, 3).'"';
115  unset($ThisFileInfo['fileformat']);
116  unset($ThisFileInfo['mpc']);
117  return false;
118 
119  }
120 
121  // Continue with SV7+ handling
122  $StreamVersionByte = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1));
123  $offset += 1;
124  $thisfile_mpc_header['stream_major_version'] = ($StreamVersionByte & 0x0F);
125  $thisfile_mpc_header['stream_minor_version'] = ($StreamVersionByte & 0xF0) >> 4;
126  $thisfile_mpc_header['frame_count'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
127  $offset += 4;
128 
129  switch ($thisfile_mpc_header['stream_major_version']) {
130  case 7:
131  //$ThisFileInfo['fileformat'] = 'SV7';
132  break;
133 
134  default:
135  $ThisFileInfo['error'][] = 'Only Musepack SV7 supported';
136  return false;
137  }
138 
139  $FlagsDWORD1 = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
140  $offset += 4;
141  $thisfile_mpc_header['intensity_stereo'] = (bool) (($FlagsDWORD1 & 0x80000000) >> 31);
142  $thisfile_mpc_header['mid_side_stereo'] = (bool) (($FlagsDWORD1 & 0x40000000) >> 30);
143  $thisfile_mpc_header['max_subband'] = ($FlagsDWORD1 & 0x3F000000) >> 24;
144  $thisfile_mpc_header['raw']['profile'] = ($FlagsDWORD1 & 0x00F00000) >> 20;
145  $thisfile_mpc_header['begin_loud'] = (bool) (($FlagsDWORD1 & 0x00080000) >> 19);
146  $thisfile_mpc_header['end_loud'] = (bool) (($FlagsDWORD1 & 0x00040000) >> 18);
147  $thisfile_mpc_header['raw']['sample_rate'] = ($FlagsDWORD1 & 0x00030000) >> 16;
148  $thisfile_mpc_header['max_level'] = ($FlagsDWORD1 & 0x0000FFFF);
149 
150  $thisfile_mpc_header['raw']['title_peak'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2));
151  $offset += 2;
152  $thisfile_mpc_header['raw']['title_gain'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true);
153  $offset += 2;
154 
155  $thisfile_mpc_header['raw']['album_peak'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2));
156  $offset += 2;
157  $thisfile_mpc_header['raw']['album_gain'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true);
158  $offset += 2;
159 
160  $FlagsDWORD2 = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
161  $offset += 4;
162  $thisfile_mpc_header['true_gapless'] = (bool) (($FlagsDWORD2 & 0x80000000) >> 31);
163  $thisfile_mpc_header['last_frame_length'] = ($FlagsDWORD2 & 0x7FF00000) >> 20;
164 
165 
166  $thisfile_mpc_header['raw']['not_sure_what'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 3));
167  $offset += 3;
168  $thisfile_mpc_header['raw']['encoder_version'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1));
169  $offset += 1;
170 
171  $thisfile_mpc_header['profile'] = $this->MPCprofileNameLookup($thisfile_mpc_header['raw']['profile']);
172  $thisfile_mpc_header['sample_rate'] = $this->MPCfrequencyLookup($thisfile_mpc_header['raw']['sample_rate']);
173  if ($thisfile_mpc_header['sample_rate'] == 0) {
174  $ThisFileInfo['error'][] = 'Corrupt MPC file: frequency == zero';
175  return false;
176  }
177  $ThisFileInfo['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate'];
178  $thisfile_mpc_header['samples'] = ((($thisfile_mpc_header['frame_count'] - 1) * 1152) + $thisfile_mpc_header['last_frame_length']) * $ThisFileInfo['audio']['channels'];
179 
180  $ThisFileInfo['playtime_seconds'] = ($thisfile_mpc_header['samples'] / $ThisFileInfo['audio']['channels']) / $ThisFileInfo['audio']['sample_rate'];
181  if ($ThisFileInfo['playtime_seconds'] == 0) {
182  $ThisFileInfo['error'][] = 'Corrupt MPC file: playtime_seconds == zero';
183  return false;
184  }
185 
186  // add size of file header to avdataoffset - calc bitrate correctly + MD5 data
187  $ThisFileInfo['avdataoffset'] += $thisfile_mpc_header['size'];
188 
189  $ThisFileInfo['audio']['bitrate'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / $ThisFileInfo['playtime_seconds'];
190 
191  $thisfile_mpc_header['title_peak'] = $thisfile_mpc_header['raw']['title_peak'];
192  $thisfile_mpc_header['title_peak_db'] = $this->MPCpeakDBLookup($thisfile_mpc_header['title_peak']);
193  if ($thisfile_mpc_header['raw']['title_gain'] < 0) {
194  $thisfile_mpc_header['title_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['title_gain']) / -100;
195  } else {
196  $thisfile_mpc_header['title_gain_db'] = (float) $thisfile_mpc_header['raw']['title_gain'] / 100;
197  }
198 
199  $thisfile_mpc_header['album_peak'] = $thisfile_mpc_header['raw']['album_peak'];
200  $thisfile_mpc_header['album_peak_db'] = $this->MPCpeakDBLookup($thisfile_mpc_header['album_peak']);
201  if ($thisfile_mpc_header['raw']['album_gain'] < 0) {
202  $thisfile_mpc_header['album_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['album_gain']) / -100;
203  } else {
204  $thisfile_mpc_header['album_gain_db'] = (float) $thisfile_mpc_header['raw']['album_gain'] / 100;;
205  }
206  $thisfile_mpc_header['encoder_version'] = $this->MPCencoderVersionLookup($thisfile_mpc_header['raw']['encoder_version']);
207 
208  $ThisFileInfo['replay_gain']['track']['adjustment'] = $thisfile_mpc_header['title_gain_db'];
209  $ThisFileInfo['replay_gain']['album']['adjustment'] = $thisfile_mpc_header['album_gain_db'];
210 
211  if ($thisfile_mpc_header['title_peak'] > 0) {
212  $ThisFileInfo['replay_gain']['track']['peak'] = $thisfile_mpc_header['title_peak'];
213  } elseif (round($thisfile_mpc_header['max_level'] * 1.18) > 0) {
214  $ThisFileInfo['replay_gain']['track']['peak'] = getid3_lib::CastAsInt(round($thisfile_mpc_header['max_level'] * 1.18)); // why? I don't know - see mppdec.c
215  }
216  if ($thisfile_mpc_header['album_peak'] > 0) {
217  $ThisFileInfo['replay_gain']['album']['peak'] = $thisfile_mpc_header['album_peak'];
218  }
219 
220  //$ThisFileInfo['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_major_version'].'.'.$thisfile_mpc_header['stream_minor_version'].', '.$thisfile_mpc_header['encoder_version'];
221  $ThisFileInfo['audio']['encoder'] = $thisfile_mpc_header['encoder_version'];
222  $ThisFileInfo['audio']['encoder_options'] = $thisfile_mpc_header['profile'];
223 
224  return true;
225  }
226 
227  function MPCprofileNameLookup($profileid) {
228  static $MPCprofileNameLookup = array(
229  0 => 'no profile',
230  1 => 'Experimental',
231  2 => 'unused',
232  3 => 'unused',
233  4 => 'unused',
234  5 => 'below Telephone (q = 0.0)',
235  6 => 'below Telephone (q = 1.0)',
236  7 => 'Telephone (q = 2.0)',
237  8 => 'Thumb (q = 3.0)',
238  9 => 'Radio (q = 4.0)',
239  10 => 'Standard (q = 5.0)',
240  11 => 'Extreme (q = 6.0)',
241  12 => 'Insane (q = 7.0)',
242  13 => 'BrainDead (q = 8.0)',
243  14 => 'above BrainDead (q = 9.0)',
244  15 => 'above BrainDead (q = 10.0)'
245  );
246  return (isset($MPCprofileNameLookup[$profileid]) ? $MPCprofileNameLookup[$profileid] : 'invalid');
247  }
248 
249  function MPCfrequencyLookup($frequencyid) {
250  static $MPCfrequencyLookup = array(
251  0 => 44100,
252  1 => 48000,
253  2 => 37800,
254  3 => 32000
255  );
256  return (isset($MPCfrequencyLookup[$frequencyid]) ? $MPCfrequencyLookup[$frequencyid] : 'invalid');
257  }
258 
259  function MPCpeakDBLookup($intvalue) {
260  if ($intvalue > 0) {
261  return ((log10($intvalue) / log10(2)) - 15) * 6;
262  }
263  return false;
264  }
265 
266  function MPCencoderVersionLookup($encoderversion) {
267  //Encoder version * 100 (106 = 1.06)
268  //EncoderVersion % 10 == 0 Release (1.0)
269  //EncoderVersion % 2 == 0 Beta (1.06)
270  //EncoderVersion % 2 == 1 Alpha (1.05a...z)
271 
272  if ($encoderversion == 0) {
273  // very old version, not known exactly which
274  return 'Buschmann v1.7.0-v1.7.9 or Klemm v0.90-v1.05';
275  }
276 
277  if (($encoderversion % 10) == 0) {
278 
279  // release version
280  return number_format($encoderversion / 100, 2);
281 
282  } elseif (($encoderversion % 2) == 0) {
283 
284  // beta version
285  return number_format($encoderversion / 100, 2).' beta';
286 
287  }
288 
289  // alpha version
290  return number_format($encoderversion / 100, 2).' alpha';
291  }
292 
293 }
294 
295 
296 ?>