ecommun / owncloud_ynh

Blame view

sources/3rdparty/getid3/module.audio.mpc.php 22.7 KB
edit raw normal view history
03e52840d   Kload   Init 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
 
  <?php
  /////////////////////////////////////////////////////////////////
  /// getID3() by James Heinrich <info@getid3.org>               //
  //  available at http://getid3.sourceforge.net                 //
  //            or http://www.getid3.org                         //
  /////////////////////////////////////////////////////////////////
  // See readme.txt for more details                             //
  /////////////////////////////////////////////////////////////////
  //                                                             //
  // module.audio.mpc.php                                        //
  // module for analyzing Musepack/MPEG+ Audio files             //
  // dependencies: NONE                                          //
  //                                                            ///
  /////////////////////////////////////////////////////////////////
  
  
  class getid3_mpc extends getid3_handler
  {
31b7f2792   Kload   Upgrade to ownclo... 
19
 
  	public function Analyze() {
03e52840d   Kload   Init 
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
 
  		$info = &$this->getid3->info;
  
  		$info['mpc']['header'] = array();
  		$thisfile_mpc_header   = &$info['mpc']['header'];
  
  		$info['fileformat']               = 'mpc';
  		$info['audio']['dataformat']      = 'mpc';
  		$info['audio']['bitrate_mode']    = 'vbr';
  		$info['audio']['channels']        = 2;  // up to SV7 the format appears to have been hardcoded for stereo only
  		$info['audio']['lossless']        = false;
  
  		fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
  		$MPCheaderData = fread($this->getid3->fp, 4);
  		$info['mpc']['header']['preamble'] = substr($MPCheaderData, 0, 4); // should be 'MPCK' (SV8) or 'MP+' (SV7), otherwise possible stream data (SV4-SV6)
  		if (preg_match('#^MPCK#', $info['mpc']['header']['preamble'])) {
  
  			// this is SV8
  			return $this->ParseMPCsv8();
  
  		} elseif (preg_match('#^MP\+#', $info['mpc']['header']['preamble'])) {
  
  			// this is SV7
  			return $this->ParseMPCsv7();
  
  		} 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', $MPCheaderData)) {
  
  			// this is SV4 - SV6, handle seperately
  			return $this->ParseMPCsv6();
  
  		} else {
  
  			$info['error'][] = 'Expecting "MP+" or "MPCK" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes(substr($MPCheaderData, 0, 4)).'"';
  			unset($info['fileformat']);
  			unset($info['mpc']);
  			return false;
  
  		}
  		return false;
  	}
31b7f2792   Kload   Upgrade to ownclo... 
59
 
  	public function ParseMPCsv8() {
03e52840d   Kload   Init 
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
 
  		// this is SV8
  		// http://trac.musepack.net/trac/wiki/SV8Specification
  
  		$info = &$this->getid3->info;
  		$thisfile_mpc_header = &$info['mpc']['header'];
  
  		$keyNameSize            = 2;
  		$maxHandledPacketLength = 9; // specs say: "n*8; 0 < n < 10"
  
  		$offset = ftell($this->getid3->fp);
  		while ($offset < $info['avdataend']) {
  			$thisPacket = array();
  			$thisPacket['offset'] = $offset;
  			$packet_offset = 0;
  
  			// Size is a variable-size field, could be 1-4 bytes (possibly more?)
  			// read enough data in and figure out the exact size later
  			$MPCheaderData = fread($this->getid3->fp, $keyNameSize + $maxHandledPacketLength);
  			$packet_offset += $keyNameSize;
  			$thisPacket['key']      = substr($MPCheaderData, 0, $keyNameSize);
  			$thisPacket['key_name'] = $this->MPCsv8PacketName($thisPacket['key']);
  			if ($thisPacket['key'] == $thisPacket['key_name']) {
  				$info['error'][] = 'Found unexpected key value "'.$thisPacket['key'].'" at offset '.$thisPacket['offset'];
  				return false;
  			}
  			$packetLength = 0;
  			$thisPacket['packet_size'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $keyNameSize), $packetLength); // includes keyname and packet_size field
  			if ($thisPacket['packet_size'] === false) {
  				$info['error'][] = 'Did not find expected packet length within '.$maxHandledPacketLength.' bytes at offset '.($thisPacket['offset'] + $keyNameSize);
  				return false;
  			}
  			$packet_offset += $packetLength;
  			$offset += $thisPacket['packet_size'];
  
  			switch ($thisPacket['key']) {
  				case 'SH': // Stream Header
  					$moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength;
  					if ($moreBytesToRead > 0) {
  						$MPCheaderData .= fread($this->getid3->fp, $moreBytesToRead);
  					}
  					$thisPacket['crc']               =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 4));
  					$packet_offset += 4;
  					$thisPacket['stream_version']    =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
  					$packet_offset += 1;
  
  					$packetLength = 0;
  					$thisPacket['sample_count']      = $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength);
  					$packet_offset += $packetLength;
  
  					$packetLength = 0;
  					$thisPacket['beginning_silence'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength);
  					$packet_offset += $packetLength;
  
  					$otherUsefulData                 =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
  					$packet_offset += 2;
  					$thisPacket['sample_frequency_raw'] =        (($otherUsefulData & 0xE000) >> 13);
  					$thisPacket['max_bands_used']       =        (($otherUsefulData & 0x1F00) >>  8);
  					$thisPacket['channels']             =        (($otherUsefulData & 0x00F0) >>  4) + 1;
  					$thisPacket['ms_used']              = (bool) (($otherUsefulData & 0x0008) >>  3);
  					$thisPacket['audio_block_frames']   =        (($otherUsefulData & 0x0007) >>  0);
  					$thisPacket['sample_frequency']     = $this->MPCfrequencyLookup($thisPacket['sample_frequency_raw']);
  
  					$thisfile_mpc_header['mid_side_stereo']      = $thisPacket['ms_used'];
  					$thisfile_mpc_header['sample_rate']          = $thisPacket['sample_frequency'];
  					$thisfile_mpc_header['samples']              = $thisPacket['sample_count'];
  					$thisfile_mpc_header['stream_version_major'] = $thisPacket['stream_version'];
  
  					$info['audio']['channels']    = $thisPacket['channels'];
  					$info['audio']['sample_rate'] = $thisPacket['sample_frequency'];
  					$info['playtime_seconds'] = $thisPacket['sample_count'] / $thisPacket['sample_frequency'];
  					$info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
  					break;
  
  				case 'RG': // Replay Gain
  					$moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength;
  					if ($moreBytesToRead > 0) {
  						$MPCheaderData .= fread($this->getid3->fp, $moreBytesToRead);
  					}
  					$thisPacket['replaygain_version']     =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
  					$packet_offset += 1;
  					$thisPacket['replaygain_title_gain']  =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
  					$packet_offset += 2;
  					$thisPacket['replaygain_title_peak']  =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
  					$packet_offset += 2;
  					$thisPacket['replaygain_album_gain']  =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
  					$packet_offset += 2;
  					$thisPacket['replaygain_album_peak']  =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
  					$packet_offset += 2;
  
  					if ($thisPacket['replaygain_title_gain']) { $info['replay_gain']['title']['gain'] = $thisPacket['replaygain_title_gain']; }
  					if ($thisPacket['replaygain_title_peak']) { $info['replay_gain']['title']['peak'] = $thisPacket['replaygain_title_peak']; }
  					if ($thisPacket['replaygain_album_gain']) { $info['replay_gain']['album']['gain'] = $thisPacket['replaygain_album_gain']; }
  					if ($thisPacket['replaygain_album_peak']) { $info['replay_gain']['album']['peak'] = $thisPacket['replaygain_album_peak']; }
  					break;
  
  				case 'EI': // Encoder Info
  					$moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength;
  					if ($moreBytesToRead > 0) {
  						$MPCheaderData .= fread($this->getid3->fp, $moreBytesToRead);
  					}
  					$profile_pns                 = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
  					$packet_offset += 1;
  					$quality_int =                   (($profile_pns & 0xF0) >> 4);
  					$quality_dec =                   (($profile_pns & 0x0E) >> 3);
  					$thisPacket['quality'] = (float) $quality_int + ($quality_dec / 8);
  					$thisPacket['pns_tool'] = (bool) (($profile_pns & 0x01) >> 0);
  					$thisPacket['version_major'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
  					$packet_offset += 1;
  					$thisPacket['version_minor'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
  					$packet_offset += 1;
  					$thisPacket['version_build'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
  					$packet_offset += 1;
  					$thisPacket['version'] = $thisPacket['version_major'].'.'.$thisPacket['version_minor'].'.'.$thisPacket['version_build'];
  
  					$info['audio']['encoder'] = 'MPC v'.$thisPacket['version'].' ('.(($thisPacket['version_minor'] % 2) ? 'unstable' : 'stable').')';
  					$thisfile_mpc_header['encoder_version'] = $info['audio']['encoder'];
  					//$thisfile_mpc_header['quality']         = (float) ($thisPacket['quality'] / 1.5875); // values can range from 0.000 to 15.875, mapped to qualities of 0.0 to 10.0
  					$thisfile_mpc_header['quality']         = (float) ($thisPacket['quality'] - 5); // values can range from 0.000 to 15.875, of which 0..4 are "reserved/experimental", and 5..15 are mapped to qualities of 0.0 to 10.0
  					break;
  
  				case 'SO': // Seek Table Offset
  					$packetLength = 0;
  					$thisPacket['seek_table_offset'] = $thisPacket['offset'] + $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength);
  					$packet_offset += $packetLength;
  					break;
  
  				case 'ST': // Seek Table
  				case 'SE': // Stream End
  				case 'AP': // Audio Data
  					// nothing useful here, just skip this packet
  					$thisPacket = array();
  					break;
  
  				default:
  					$info['error'][] = 'Found unhandled key type "'.$thisPacket['key'].'" at offset '.$thisPacket['offset'];
  					return false;
  					break;
  			}
  			if (!empty($thisPacket)) {
  				$info['mpc']['packets'][] = $thisPacket;
  			}
  			fseek($this->getid3->fp, $offset);
  		}
  		$thisfile_mpc_header['size'] = $offset;
  		return true;
  	}
31b7f2792   Kload   Upgrade to ownclo... 
206
 
  	public function ParseMPCsv7() {
03e52840d   Kload   Init 
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
 
  		// this is SV7
  		// http://www.uni-jena.de/~pfk/mpp/sv8/header.html
  
  		$info = &$this->getid3->info;
  		$thisfile_mpc_header = &$info['mpc']['header'];
  		$offset = 0;
  
  		$thisfile_mpc_header['size'] = 28;
  		$MPCheaderData  = $info['mpc']['header']['preamble'];
  		$MPCheaderData .= fread($this->getid3->fp, $thisfile_mpc_header['size'] - strlen($info['mpc']['header']['preamble']));
  		$offset = strlen('MP+');
  
  		$StreamVersionByte                           = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1));
  		$offset += 1;
  		$thisfile_mpc_header['stream_version_major'] = ($StreamVersionByte & 0x0F) >> 0;
  		$thisfile_mpc_header['stream_version_minor'] = ($StreamVersionByte & 0xF0) >> 4; // should always be 0, subversions no longer exist in SV8
  		$thisfile_mpc_header['frame_count']          = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
  		$offset += 4;
  
  		if ($thisfile_mpc_header['stream_version_major'] != 7) {
  			$info['error'][] = 'Only Musepack SV7 supported (this file claims to be v'.$thisfile_mpc_header['stream_version_major'].')';
  			return false;
  		}
  
  		$FlagsDWORD1                                   = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
  		$offset += 4;
  		$thisfile_mpc_header['intensity_stereo']       = (bool) (($FlagsDWORD1 & 0x80000000) >> 31);
  		$thisfile_mpc_header['mid_side_stereo']        = (bool) (($FlagsDWORD1 & 0x40000000) >> 30);
  		$thisfile_mpc_header['max_subband']            =         ($FlagsDWORD1 & 0x3F000000) >> 24;
  		$thisfile_mpc_header['raw']['profile']         =         ($FlagsDWORD1 & 0x00F00000) >> 20;
  		$thisfile_mpc_header['begin_loud']             = (bool) (($FlagsDWORD1 & 0x00080000) >> 19);
  		$thisfile_mpc_header['end_loud']               = (bool) (($FlagsDWORD1 & 0x00040000) >> 18);
  		$thisfile_mpc_header['raw']['sample_rate']     =         ($FlagsDWORD1 & 0x00030000) >> 16;
  		$thisfile_mpc_header['max_level']              =         ($FlagsDWORD1 & 0x0000FFFF);
  
  		$thisfile_mpc_header['raw']['title_peak']      = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2));
  		$offset += 2;
  		$thisfile_mpc_header['raw']['title_gain']      = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true);
  		$offset += 2;
  
  		$thisfile_mpc_header['raw']['album_peak']      = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2));
  		$offset += 2;
  		$thisfile_mpc_header['raw']['album_gain']      = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true);
  		$offset += 2;
  
  		$FlagsDWORD2                                   = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
  		$offset += 4;
  		$thisfile_mpc_header['true_gapless']           = (bool) (($FlagsDWORD2 & 0x80000000) >> 31);
  		$thisfile_mpc_header['last_frame_length']      =         ($FlagsDWORD2 & 0x7FF00000) >> 20;
  
  
  		$thisfile_mpc_header['raw']['not_sure_what']   = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 3));
  		$offset += 3;
  		$thisfile_mpc_header['raw']['encoder_version'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1));
  		$offset += 1;
  
  		$thisfile_mpc_header['profile']     = $this->MPCprofileNameLookup($thisfile_mpc_header['raw']['profile']);
  		$thisfile_mpc_header['sample_rate'] = $this->MPCfrequencyLookup($thisfile_mpc_header['raw']['sample_rate']);
  		if ($thisfile_mpc_header['sample_rate'] == 0) {
  			$info['error'][] = 'Corrupt MPC file: frequency == zero';
  			return false;
  		}
  		$info['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate'];
  		$thisfile_mpc_header['samples']       = ((($thisfile_mpc_header['frame_count'] - 1) * 1152) + $thisfile_mpc_header['last_frame_length']) * $info['audio']['channels'];
  
  		$info['playtime_seconds']     = ($thisfile_mpc_header['samples'] / $info['audio']['channels']) / $info['audio']['sample_rate'];
  		if ($info['playtime_seconds'] == 0) {
  			$info['error'][] = 'Corrupt MPC file: playtime_seconds == zero';
  			return false;
  		}
  
  		// add size of file header to avdataoffset - calc bitrate correctly + MD5 data
  		$info['avdataoffset'] += $thisfile_mpc_header['size'];
  
  		$info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
  
  		$thisfile_mpc_header['title_peak']        = $thisfile_mpc_header['raw']['title_peak'];
  		$thisfile_mpc_header['title_peak_db']     = $this->MPCpeakDBLookup($thisfile_mpc_header['title_peak']);
  		if ($thisfile_mpc_header['raw']['title_gain'] < 0) {
  			$thisfile_mpc_header['title_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['title_gain']) / -100;
  		} else {
  			$thisfile_mpc_header['title_gain_db'] = (float) $thisfile_mpc_header['raw']['title_gain'] / 100;
  		}
  
  		$thisfile_mpc_header['album_peak']        = $thisfile_mpc_header['raw']['album_peak'];
  		$thisfile_mpc_header['album_peak_db']     = $this->MPCpeakDBLookup($thisfile_mpc_header['album_peak']);
  		if ($thisfile_mpc_header['raw']['album_gain'] < 0) {
  			$thisfile_mpc_header['album_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['album_gain']) / -100;
  		} else {
  			$thisfile_mpc_header['album_gain_db'] = (float) $thisfile_mpc_header['raw']['album_gain'] / 100;;
  		}
  		$thisfile_mpc_header['encoder_version']   = $this->MPCencoderVersionLookup($thisfile_mpc_header['raw']['encoder_version']);
  
  		$info['replay_gain']['track']['adjustment'] = $thisfile_mpc_header['title_gain_db'];
  		$info['replay_gain']['album']['adjustment'] = $thisfile_mpc_header['album_gain_db'];
  
  		if ($thisfile_mpc_header['title_peak'] > 0) {
  			$info['replay_gain']['track']['peak'] = $thisfile_mpc_header['title_peak'];
  		} elseif (round($thisfile_mpc_header['max_level'] * 1.18) > 0) {
  			$info['replay_gain']['track']['peak'] = getid3_lib::CastAsInt(round($thisfile_mpc_header['max_level'] * 1.18)); // why? I don't know - see mppdec.c
  		}
  		if ($thisfile_mpc_header['album_peak'] > 0) {
  			$info['replay_gain']['album']['peak'] = $thisfile_mpc_header['album_peak'];
  		}
  
  		//$info['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_version_major'].'.'.$thisfile_mpc_header['stream_version_minor'].', '.$thisfile_mpc_header['encoder_version'];
  		$info['audio']['encoder'] = $thisfile_mpc_header['encoder_version'];
  		$info['audio']['encoder_options'] = $thisfile_mpc_header['profile'];
  		$thisfile_mpc_header['quality'] = (float) ($thisfile_mpc_header['raw']['profile'] - 5); // values can range from 0 to 15, of which 0..4 are "reserved/experimental", and 5..15 are mapped to qualities of 0.0 to 10.0
  
  		return true;
  	}
31b7f2792   Kload   Upgrade to ownclo... 
319
 
  	public function ParseMPCsv6() {
03e52840d   Kload   Init 
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
 
  		// this is SV4 - SV6
  
  		$info = &$this->getid3->info;
  		$thisfile_mpc_header = &$info['mpc']['header'];
  		$offset = 0;
  
  		$thisfile_mpc_header['size'] = 8;
  		fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
  		$MPCheaderData = fread($this->getid3->fp, $thisfile_mpc_header['size']);
  
  		// add size of file header to avdataoffset - calc bitrate correctly + MD5 data
  		$info['avdataoffset'] += $thisfile_mpc_header['size'];
  
  		// Most of this code adapted from Jurgen Faul's MPEGplus source code - thanks Jurgen! :)
  		$HeaderDWORD[0] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 0, 4));
  		$HeaderDWORD[1] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 4, 4));
  
  
  		// DDDD DDDD  CCCC CCCC  BBBB BBBB  AAAA AAAA
  		// aaaa aaaa  abcd dddd  dddd deee  eeff ffff
  		//
  		// a = bitrate       = anything
  		// b = IS            = anything
  		// c = MS            = anything
  		// d = streamversion = 0000000004 or 0000000005 or 0000000006
  		// e = maxband       = anything
  		// f = blocksize     = 000001 for SV5+, anything(?) for SV4
  
  		$thisfile_mpc_header['target_bitrate']       =        (($HeaderDWORD[0] & 0xFF800000) >> 23);
  		$thisfile_mpc_header['intensity_stereo']     = (bool) (($HeaderDWORD[0] & 0x00400000) >> 22);
  		$thisfile_mpc_header['mid_side_stereo']      = (bool) (($HeaderDWORD[0] & 0x00200000) >> 21);
  		$thisfile_mpc_header['stream_version_major'] =         ($HeaderDWORD[0] & 0x001FF800) >> 11;
  		$thisfile_mpc_header['stream_version_minor'] = 0; // no sub-version numbers before SV7
  		$thisfile_mpc_header['max_band']             =         ($HeaderDWORD[0] & 0x000007C0) >>  6;  // related to lowpass frequency, not sure how it translates exactly
  		$thisfile_mpc_header['block_size']           =         ($HeaderDWORD[0] & 0x0000003F);
  
  		switch ($thisfile_mpc_header['stream_version_major']) {
  			case 4:
  				$thisfile_mpc_header['frame_count'] = ($HeaderDWORD[1] >> 16);
  				break;
  
  			case 5:
  			case 6:
  				$thisfile_mpc_header['frame_count'] =  $HeaderDWORD[1];
  				break;
  
  			default:
  				$info['error'] = 'Expecting 4, 5 or 6 in version field, found '.$thisfile_mpc_header['stream_version_major'].' instead';
  				unset($info['mpc']);
  				return false;
  				break;
  		}
  
  		if (($thisfile_mpc_header['stream_version_major'] > 4) && ($thisfile_mpc_header['block_size'] != 1)) {
  			$info['warning'][] = 'Block size expected to be 1, actual value found: '.$thisfile_mpc_header['block_size'];
  		}
  
  		$thisfile_mpc_header['sample_rate']   = 44100; // AB: used by all files up to SV7
  		$info['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate'];
  		$thisfile_mpc_header['samples']       = $thisfile_mpc_header['frame_count'] * 1152 * $info['audio']['channels'];
  
  		if ($thisfile_mpc_header['target_bitrate'] == 0) {
  			$info['audio']['bitrate_mode'] = 'vbr';
  		} else {
  			$info['audio']['bitrate_mode'] = 'cbr';
  		}
  
  		$info['mpc']['bitrate']   = ($info['avdataend'] - $info['avdataoffset']) * 8 * 44100 / $thisfile_mpc_header['frame_count'] / 1152;
  		$info['audio']['bitrate'] = $info['mpc']['bitrate'];
  		$info['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_version_major'];
  
  		return true;
  	}
31b7f2792   Kload   Upgrade to ownclo... 
393
 
  	public function MPCprofileNameLookup($profileid) {
03e52840d   Kload   Init 
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
 
  		static $MPCprofileNameLookup = array(
  			0  => 'no profile',
  			1  => 'Experimental',
  			2  => 'unused',
  			3  => 'unused',
  			4  => 'unused',
  			5  => 'below Telephone (q = 0.0)',
  			6  => 'below Telephone (q = 1.0)',
  			7  => 'Telephone (q = 2.0)',
  			8  => 'Thumb (q = 3.0)',
  			9  => 'Radio (q = 4.0)',
  			10 => 'Standard (q = 5.0)',
  			11 => 'Extreme (q = 6.0)',
  			12 => 'Insane (q = 7.0)',
  			13 => 'BrainDead (q = 8.0)',
  			14 => 'above BrainDead (q = 9.0)',
  			15 => 'above BrainDead (q = 10.0)'
  		);
  		return (isset($MPCprofileNameLookup[$profileid]) ? $MPCprofileNameLookup[$profileid] : 'invalid');
  	}
31b7f2792   Kload   Upgrade to ownclo... 
414
 
  	public function MPCfrequencyLookup($frequencyid) {
03e52840d   Kload   Init 
415
416
417
418
419
420
421
422
 
  		static $MPCfrequencyLookup = array(
  			0 => 44100,
  			1 => 48000,
  			2 => 37800,
  			3 => 32000
  		);
  		return (isset($MPCfrequencyLookup[$frequencyid]) ? $MPCfrequencyLookup[$frequencyid] : 'invalid');
  	}
31b7f2792   Kload   Upgrade to ownclo... 
423
 
  	public function MPCpeakDBLookup($intvalue) {
03e52840d   Kload   Init 
424
425
426
427
428
 
  		if ($intvalue > 0) {
  			return ((log10($intvalue) / log10(2)) - 15) * 6;
  		}
  		return false;
  	}
31b7f2792   Kload   Upgrade to ownclo... 
429
 
  	public function MPCencoderVersionLookup($encoderversion) {
03e52840d   Kload   Init 
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
 
  		//Encoder version * 100  (106 = 1.06)
  		//EncoderVersion % 10 == 0        Release (1.0)
  		//EncoderVersion %  2 == 0        Beta (1.06)
  		//EncoderVersion %  2 == 1        Alpha (1.05a...z)
  
  		if ($encoderversion == 0) {
  			// very old version, not known exactly which
  			return 'Buschmann v1.7.0-v1.7.9 or Klemm v0.90-v1.05';
  		}
  
  		if (($encoderversion % 10) == 0) {
  
  			// release version
  			return number_format($encoderversion / 100, 2);
  
  		} elseif (($encoderversion % 2) == 0) {
  
  			// beta version
  			return number_format($encoderversion / 100, 2).' beta';
  
  		}
  
  		// alpha version
  		return number_format($encoderversion / 100, 2).' alpha';
  	}
31b7f2792   Kload   Upgrade to ownclo... 
455
 
  	public function SV8variableLengthInteger($data, &$packetLength, $maxHandledPacketLength=9) {
03e52840d   Kload   Init 
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
 
  		$packet_size = 0;
  		for ($packetLength = 1; $packetLength <= $maxHandledPacketLength; $packetLength++) {
  			// variable-length size field:
  			//  bits, big-endian
  			//  0xxx xxxx                                           - value 0 to  2^7-1
  			//  1xxx xxxx  0xxx xxxx                                - value 0 to 2^14-1
  			//  1xxx xxxx  1xxx xxxx  0xxx xxxx                     - value 0 to 2^21-1
  			//  1xxx xxxx  1xxx xxxx  1xxx xxxx  0xxx xxxx          - value 0 to 2^28-1
  			//  ...
  			$thisbyte = ord(substr($data, ($packetLength - 1), 1));
  			// look through bytes until find a byte with MSB==0
  			$packet_size = ($packet_size << 7);
  			$packet_size = ($packet_size | ($thisbyte & 0x7F));
  			if (($thisbyte & 0x80) === 0) {
  				break;
  			}
  			if ($packetLength >= $maxHandledPacketLength) {
  				return false;
  			}
  		}
  		return $packet_size;
  	}
31b7f2792   Kload   Upgrade to ownclo... 
478
 
  	public function MPCsv8PacketName($packetKey) {
03e52840d   Kload   Init 
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
 
  		static $MPCsv8PacketName = array();
  		if (empty($MPCsv8PacketName)) {
  			$MPCsv8PacketName = array(
  				'AP' => 'Audio Packet',
  				'CT' => 'Chapter Tag',
  				'EI' => 'Encoder Info',
  				'RG' => 'Replay Gain',
  				'SE' => 'Stream End',
  				'SH' => 'Stream Header',
  				'SO' => 'Seek Table Offset',
  				'ST' => 'Seek Table',
  			);
  		}
  		return (isset($MPCsv8PacketName[$packetKey]) ? $MPCsv8PacketName[$packetKey] : $packetKey);
  	}
  }