ILIAS  release_5-1 Revision 5.0.0-5477-g43f3e3fab5f
Public Member Functions
getid3_mpc Class Reference

getID3() by James Heinrich info@.nosp@m.geti.nosp@m.d3.or.nosp@m.g // More...

+ Inheritance diagram for getid3_mpc:
+ Collaboration diagram for getid3_mpc:

Public Member Functions

 getid3_mpc (&$fd, &$ThisFileInfo)
 
 MPCprofileNameLookup ($profileid)
 
 MPCfrequencyLookup ($frequencyid)
 
 MPCpeakDBLookup ($intvalue)
 
 MPCencoderVersionLookup ($encoderversion)
 
 Analyze ()
 
 ParseMPCsv8 ()
 
 ParseMPCsv7 ()
 
 ParseMPCsv6 ()
 
 MPCprofileNameLookup ($profileid)
 
 MPCfrequencyLookup ($frequencyid)
 
 MPCpeakDBLookup ($intvalue)
 
 MPCencoderVersionLookup ($encoderversion)
 
 SV8variableLengthInteger ($data, &$packetLength, $maxHandledPacketLength=9)
 
 MPCsv8PacketName ($packetKey)
 
- Public Member Functions inherited from getid3_handler
 __construct (getID3 $getid3, $call_module=null)
 
 Analyze ()
 
 AnalyzeString ($string)
 
 setStringMode ($string)
 
 saveAttachment ($name, $offset, $length, $image_mime=null)
 

Additional Inherited Members

- Protected Member Functions inherited from getid3_handler
 ftell ()
 
 fread ($bytes)
 
 fseek ($bytes, $whence=SEEK_SET)
 
 feof ()
 
 isDependencyFor ($module)
 
 error ($text)
 
 warning ($text)
 
 notice ($text)
 
- Protected Attributes inherited from getid3_handler
 $getid3
 
 $data_string_flag = false
 
 $data_string = ''
 
 $data_string_position = 0
 
 $data_string_length = 0
 

Detailed Description

getID3() by James Heinrich info@.nosp@m.geti.nosp@m.d3.or.nosp@m.g //

Definition at line 17 of file module.audio.mpc.php.

Member Function Documentation

◆ Analyze()

getid3_mpc::Analyze ( )

Reimplemented from getid3_handler.

Definition at line 21 of file module.audio.mpc.php.

21 {
22 $info = &$this->getid3->info;
23
24 $info['mpc']['header'] = array();
25 $thisfile_mpc_header = &$info['mpc']['header'];
26
27 $info['fileformat'] = 'mpc';
28 $info['audio']['dataformat'] = 'mpc';
29 $info['audio']['bitrate_mode'] = 'vbr';
30 $info['audio']['channels'] = 2; // up to SV7 the format appears to have been hardcoded for stereo only
31 $info['audio']['lossless'] = false;
32
33 $this->fseek($info['avdataoffset']);
34 $MPCheaderData = $this->fread(4);
35 $info['mpc']['header']['preamble'] = substr($MPCheaderData, 0, 4); // should be 'MPCK' (SV8) or 'MP+' (SV7), otherwise possible stream data (SV4-SV6)
36 if (preg_match('#^MPCK#', $info['mpc']['header']['preamble'])) {
37
38 // this is SV8
39 return $this->ParseMPCsv8();
40
41 } elseif (preg_match('#^MP\+#', $info['mpc']['header']['preamble'])) {
42
43 // this is SV7
44 return $this->ParseMPCsv7();
45
46 } 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)) {
47
48 // this is SV4 - SV6, handle seperately
49 return $this->ParseMPCsv6();
50
51 } else {
52
53 $info['error'][] = 'Expecting "MP+" or "MPCK" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes(substr($MPCheaderData, 0, 4)).'"';
54 unset($info['fileformat']);
55 unset($info['mpc']);
56 return false;
57
58 }
59 return false;
60 }
getid3_handler\fseek
fseek($bytes, $whence=SEEK_SET)
Definition: getid3.php:1697
getid3_handler\fread
fread($bytes)
Definition: getid3.php:1685
getid3_lib\PrintHexBytes
PrintHexBytes($string, $hex=true, $spaces=true, $htmlsafe=true)
Definition: getid3.lib.php:17
getid3_mpc\ParseMPCsv8
ParseMPCsv8()
Definition: module.audio.mpc.php:63
getid3_mpc\ParseMPCsv7
ParseMPCsv7()
Definition: module.audio.mpc.php:211
getid3_mpc\ParseMPCsv6
ParseMPCsv6()
Definition: module.audio.mpc.php:325
$info
$info
Definition: example_052.php:80

References $info, getid3_handler\fread(), getid3_handler\fseek(), ParseMPCsv6(), ParseMPCsv7(), ParseMPCsv8(), and getid3_lib\PrintHexBytes().

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◆ getid3_mpc()

getid3_mpc::getid3_mpc ( &  $fd,
&  $ThisFileInfo 
)

Definition at line 20 of file module.audio.mpc.php.

20 {
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'] = $thisfile_mpc_header['profile'];
223
224 return true;
225 }
getid3_lib\LittleEndian2Int
LittleEndian2Int($byteword, $signed=false)
Definition: getid3.lib.php:266
getid3_lib\CastAsInt
CastAsInt($floatnum)
Definition: getid3.lib.php:60
getid3_mpc\MPCpeakDBLookup
MPCpeakDBLookup($intvalue)
Definition: module.audio.mpc.php:259
getid3_mpc\MPCencoderVersionLookup
MPCencoderVersionLookup($encoderversion)
Definition: module.audio.mpc.php:266
getid3_mpc\MPCprofileNameLookup
MPCprofileNameLookup($profileid)
Definition: module.audio.mpc.php:227
getid3_mpc\MPCfrequencyLookup
MPCfrequencyLookup($frequencyid)
Definition: module.audio.mpc.php:249

References getid3_lib\CastAsInt(), getid3_handler\fread(), getid3_handler\fseek(), getid3_lib\LittleEndian2Int(), MPCencoderVersionLookup(), MPCfrequencyLookup(), MPCpeakDBLookup(), and MPCprofileNameLookup().

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◆ MPCencoderVersionLookup() [1/2]

getid3_mpc::MPCencoderVersionLookup (   $encoderversion)

Definition at line 266 of file module.audio.mpc.php.

266 {
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 }

Referenced by getid3_mpc(), and ParseMPCsv7().

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◆ MPCencoderVersionLookup() [2/2]

getid3_mpc::MPCencoderVersionLookup (   $encoderversion)

Definition at line 440 of file module.audio.mpc.php.

440 {
441 //Encoder version * 100 (106 = 1.06)
442 //EncoderVersion % 10 == 0 Release (1.0)
443 //EncoderVersion % 2 == 0 Beta (1.06)
444 //EncoderVersion % 2 == 1 Alpha (1.05a...z)
445
446 if ($encoderversion == 0) {
447 // very old version, not known exactly which
448 return 'Buschmann v1.7.0-v1.7.9 or Klemm v0.90-v1.05';
449 }
450
451 if (($encoderversion % 10) == 0) {
452
453 // release version
454 return number_format($encoderversion / 100, 2);
455
456 } elseif (($encoderversion % 2) == 0) {
457
458 // beta version
459 return number_format($encoderversion / 100, 2).' beta';
460
461 }
462
463 // alpha version
464 return number_format($encoderversion / 100, 2).' alpha';
465 }

◆ MPCfrequencyLookup() [1/2]

getid3_mpc::MPCfrequencyLookup (   $frequencyid)

Definition at line 249 of file module.audio.mpc.php.

249 {
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 }

Referenced by getid3_mpc(), ParseMPCsv7(), and ParseMPCsv8().

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◆ MPCfrequencyLookup() [2/2]

getid3_mpc::MPCfrequencyLookup (   $frequencyid)

Definition at line 423 of file module.audio.mpc.php.

423 {
424 static $MPCfrequencyLookup = array(
425 0 => 44100,
426 1 => 48000,
427 2 => 37800,
428 3 => 32000
429 );
430 return (isset($MPCfrequencyLookup[$frequencyid]) ? $MPCfrequencyLookup[$frequencyid] : 'invalid');
431 }

◆ MPCpeakDBLookup() [1/2]

getid3_mpc::MPCpeakDBLookup (   $intvalue)

Definition at line 259 of file module.audio.mpc.php.

259 {
260 if ($intvalue > 0) {
261 return ((log10($intvalue) / log10(2)) - 15) * 6;
262 }
263 return false;
264 }

Referenced by getid3_mpc(), and ParseMPCsv7().

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◆ MPCpeakDBLookup() [2/2]

getid3_mpc::MPCpeakDBLookup (   $intvalue)

Definition at line 433 of file module.audio.mpc.php.

433 {
434 if ($intvalue > 0) {
435 return ((log10($intvalue) / log10(2)) - 15) * 6;
436 }
437 return false;
438 }

◆ MPCprofileNameLookup() [1/2]

getid3_mpc::MPCprofileNameLookup (   $profileid)

Definition at line 227 of file module.audio.mpc.php.

227 {
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 }

Referenced by getid3_mpc(), and ParseMPCsv7().

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◆ MPCprofileNameLookup() [2/2]

getid3_mpc::MPCprofileNameLookup (   $profileid)

Definition at line 401 of file module.audio.mpc.php.

401 {
402 static $MPCprofileNameLookup = array(
403 0 => 'no profile',
404 1 => 'Experimental',
405 2 => 'unused',
406 3 => 'unused',
407 4 => 'unused',
408 5 => 'below Telephone (q = 0.0)',
409 6 => 'below Telephone (q = 1.0)',
410 7 => 'Telephone (q = 2.0)',
411 8 => 'Thumb (q = 3.0)',
412 9 => 'Radio (q = 4.0)',
413 10 => 'Standard (q = 5.0)',
414 11 => 'Extreme (q = 6.0)',
415 12 => 'Insane (q = 7.0)',
416 13 => 'BrainDead (q = 8.0)',
417 14 => 'above BrainDead (q = 9.0)',
418 15 => 'above BrainDead (q = 10.0)'
419 );
420 return (isset($MPCprofileNameLookup[$profileid]) ? $MPCprofileNameLookup[$profileid] : 'invalid');
421 }

◆ MPCsv8PacketName()

getid3_mpc::MPCsv8PacketName (   $packetKey)

Definition at line 491 of file module.audio.mpc.php.

491 {
492 static $MPCsv8PacketName = array();
493 if (empty($MPCsv8PacketName)) {
494 $MPCsv8PacketName = array(
495 'AP' => 'Audio Packet',
496 'CT' => 'Chapter Tag',
497 'EI' => 'Encoder Info',
498 'RG' => 'Replay Gain',
499 'SE' => 'Stream End',
500 'SH' => 'Stream Header',
501 'SO' => 'Seek Table Offset',
502 'ST' => 'Seek Table',
503 );
504 }
505 return (isset($MPCsv8PacketName[$packetKey]) ? $MPCsv8PacketName[$packetKey] : $packetKey);
506 }

Referenced by ParseMPCsv8().

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◆ ParseMPCsv6()

getid3_mpc::ParseMPCsv6 ( )

Definition at line 325 of file module.audio.mpc.php.

325 {
326 // this is SV4 - SV6
327
328 $info = &$this->getid3->info;
329 $thisfile_mpc_header = &$info['mpc']['header'];
330 $offset = 0;
331
332 $thisfile_mpc_header['size'] = 8;
333 $this->fseek($info['avdataoffset']);
334 $MPCheaderData = $this->fread($thisfile_mpc_header['size']);
335
336 // add size of file header to avdataoffset - calc bitrate correctly + MD5 data
337 $info['avdataoffset'] += $thisfile_mpc_header['size'];
338
339 // Most of this code adapted from Jurgen Faul's MPEGplus source code - thanks Jurgen! :)
340 $HeaderDWORD[0] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 0, 4));
341 $HeaderDWORD[1] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 4, 4));
342
343
344 // DDDD DDDD CCCC CCCC BBBB BBBB AAAA AAAA
345 // aaaa aaaa abcd dddd dddd deee eeff ffff
346 //
347 // a = bitrate = anything
348 // b = IS = anything
349 // c = MS = anything
350 // d = streamversion = 0000000004 or 0000000005 or 0000000006
351 // e = maxband = anything
352 // f = blocksize = 000001 for SV5+, anything(?) for SV4
353
354 $thisfile_mpc_header['target_bitrate'] = (($HeaderDWORD[0] & 0xFF800000) >> 23);
355 $thisfile_mpc_header['intensity_stereo'] = (bool) (($HeaderDWORD[0] & 0x00400000) >> 22);
356 $thisfile_mpc_header['mid_side_stereo'] = (bool) (($HeaderDWORD[0] & 0x00200000) >> 21);
357 $thisfile_mpc_header['stream_version_major'] = ($HeaderDWORD[0] & 0x001FF800) >> 11;
358 $thisfile_mpc_header['stream_version_minor'] = 0; // no sub-version numbers before SV7
359 $thisfile_mpc_header['max_band'] = ($HeaderDWORD[0] & 0x000007C0) >> 6; // related to lowpass frequency, not sure how it translates exactly
360 $thisfile_mpc_header['block_size'] = ($HeaderDWORD[0] & 0x0000003F);
361
362 switch ($thisfile_mpc_header['stream_version_major']) {
363 case 4:
364 $thisfile_mpc_header['frame_count'] = ($HeaderDWORD[1] >> 16);
365 break;
366
367 case 5:
368 case 6:
369 $thisfile_mpc_header['frame_count'] = $HeaderDWORD[1];
370 break;
371
372 default:
373 $info['error'] = 'Expecting 4, 5 or 6 in version field, found '.$thisfile_mpc_header['stream_version_major'].' instead';
374 unset($info['mpc']);
375 return false;
376 break;
377 }
378
379 if (($thisfile_mpc_header['stream_version_major'] > 4) && ($thisfile_mpc_header['block_size'] != 1)) {
380 $info['warning'][] = 'Block size expected to be 1, actual value found: '.$thisfile_mpc_header['block_size'];
381 }
382
383 $thisfile_mpc_header['sample_rate'] = 44100; // AB: used by all files up to SV7
384 $info['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate'];
385 $thisfile_mpc_header['samples'] = $thisfile_mpc_header['frame_count'] * 1152 * $info['audio']['channels'];
386
387 if ($thisfile_mpc_header['target_bitrate'] == 0) {
388 $info['audio']['bitrate_mode'] = 'vbr';
389 } else {
390 $info['audio']['bitrate_mode'] = 'cbr';
391 }
392
393 $info['mpc']['bitrate'] = ($info['avdataend'] - $info['avdataoffset']) * 8 * 44100 / $thisfile_mpc_header['frame_count'] / 1152;
394 $info['audio']['bitrate'] = $info['mpc']['bitrate'];
395 $info['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_version_major'];
396
397 return true;
398 }

References $info, getid3_handler\fread(), getid3_handler\fseek(), and getid3_lib\LittleEndian2Int().

Referenced by Analyze().

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◆ ParseMPCsv7()

getid3_mpc::ParseMPCsv7 ( )

Definition at line 211 of file module.audio.mpc.php.

211 {
212 // this is SV7
213 // http://www.uni-jena.de/~pfk/mpp/sv8/header.html
214
215 $info = &$this->getid3->info;
216 $thisfile_mpc_header = &$info['mpc']['header'];
217 $offset = 0;
218
219 $thisfile_mpc_header['size'] = 28;
220 $MPCheaderData = $info['mpc']['header']['preamble'];
221 $MPCheaderData .= $this->fread($thisfile_mpc_header['size'] - strlen($info['mpc']['header']['preamble']));
222 $offset = strlen('MP+');
223
224 $StreamVersionByte = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1));
225 $offset += 1;
226 $thisfile_mpc_header['stream_version_major'] = ($StreamVersionByte & 0x0F) >> 0;
227 $thisfile_mpc_header['stream_version_minor'] = ($StreamVersionByte & 0xF0) >> 4; // should always be 0, subversions no longer exist in SV8
228 $thisfile_mpc_header['frame_count'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
229 $offset += 4;
230
231 if ($thisfile_mpc_header['stream_version_major'] != 7) {
232 $info['error'][] = 'Only Musepack SV7 supported (this file claims to be v'.$thisfile_mpc_header['stream_version_major'].')';
233 return false;
234 }
235
236 $FlagsDWORD1 = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
237 $offset += 4;
238 $thisfile_mpc_header['intensity_stereo'] = (bool) (($FlagsDWORD1 & 0x80000000) >> 31);
239 $thisfile_mpc_header['mid_side_stereo'] = (bool) (($FlagsDWORD1 & 0x40000000) >> 30);
240 $thisfile_mpc_header['max_subband'] = ($FlagsDWORD1 & 0x3F000000) >> 24;
241 $thisfile_mpc_header['raw']['profile'] = ($FlagsDWORD1 & 0x00F00000) >> 20;
242 $thisfile_mpc_header['begin_loud'] = (bool) (($FlagsDWORD1 & 0x00080000) >> 19);
243 $thisfile_mpc_header['end_loud'] = (bool) (($FlagsDWORD1 & 0x00040000) >> 18);
244 $thisfile_mpc_header['raw']['sample_rate'] = ($FlagsDWORD1 & 0x00030000) >> 16;
245 $thisfile_mpc_header['max_level'] = ($FlagsDWORD1 & 0x0000FFFF);
246
247 $thisfile_mpc_header['raw']['title_peak'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2));
248 $offset += 2;
249 $thisfile_mpc_header['raw']['title_gain'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true);
250 $offset += 2;
251
252 $thisfile_mpc_header['raw']['album_peak'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2));
253 $offset += 2;
254 $thisfile_mpc_header['raw']['album_gain'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true);
255 $offset += 2;
256
257 $FlagsDWORD2 = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
258 $offset += 4;
259 $thisfile_mpc_header['true_gapless'] = (bool) (($FlagsDWORD2 & 0x80000000) >> 31);
260 $thisfile_mpc_header['last_frame_length'] = ($FlagsDWORD2 & 0x7FF00000) >> 20;
261
262
263 $thisfile_mpc_header['raw']['not_sure_what'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 3));
264 $offset += 3;
265 $thisfile_mpc_header['raw']['encoder_version'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1));
266 $offset += 1;
267
268 $thisfile_mpc_header['profile'] = $this->MPCprofileNameLookup($thisfile_mpc_header['raw']['profile']);
269 $thisfile_mpc_header['sample_rate'] = $this->MPCfrequencyLookup($thisfile_mpc_header['raw']['sample_rate']);
270 if ($thisfile_mpc_header['sample_rate'] == 0) {
271 $info['error'][] = 'Corrupt MPC file: frequency == zero';
272 return false;
273 }
274 $info['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate'];
275 $thisfile_mpc_header['samples'] = ((($thisfile_mpc_header['frame_count'] - 1) * 1152) + $thisfile_mpc_header['last_frame_length']) * $info['audio']['channels'];
276
277 $info['playtime_seconds'] = ($thisfile_mpc_header['samples'] / $info['audio']['channels']) / $info['audio']['sample_rate'];
278 if ($info['playtime_seconds'] == 0) {
279 $info['error'][] = 'Corrupt MPC file: playtime_seconds == zero';
280 return false;
281 }
282
283 // add size of file header to avdataoffset - calc bitrate correctly + MD5 data
284 $info['avdataoffset'] += $thisfile_mpc_header['size'];
285
286 $info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
287
288 $thisfile_mpc_header['title_peak'] = $thisfile_mpc_header['raw']['title_peak'];
289 $thisfile_mpc_header['title_peak_db'] = $this->MPCpeakDBLookup($thisfile_mpc_header['title_peak']);
290 if ($thisfile_mpc_header['raw']['title_gain'] < 0) {
291 $thisfile_mpc_header['title_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['title_gain']) / -100;
292 } else {
293 $thisfile_mpc_header['title_gain_db'] = (float) $thisfile_mpc_header['raw']['title_gain'] / 100;
294 }
295
296 $thisfile_mpc_header['album_peak'] = $thisfile_mpc_header['raw']['album_peak'];
297 $thisfile_mpc_header['album_peak_db'] = $this->MPCpeakDBLookup($thisfile_mpc_header['album_peak']);
298 if ($thisfile_mpc_header['raw']['album_gain'] < 0) {
299 $thisfile_mpc_header['album_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['album_gain']) / -100;
300 } else {
301 $thisfile_mpc_header['album_gain_db'] = (float) $thisfile_mpc_header['raw']['album_gain'] / 100;;
302 }
303 $thisfile_mpc_header['encoder_version'] = $this->MPCencoderVersionLookup($thisfile_mpc_header['raw']['encoder_version']);
304
305 $info['replay_gain']['track']['adjustment'] = $thisfile_mpc_header['title_gain_db'];
306 $info['replay_gain']['album']['adjustment'] = $thisfile_mpc_header['album_gain_db'];
307
308 if ($thisfile_mpc_header['title_peak'] > 0) {
309 $info['replay_gain']['track']['peak'] = $thisfile_mpc_header['title_peak'];
310 } elseif (round($thisfile_mpc_header['max_level'] * 1.18) > 0) {
311 $info['replay_gain']['track']['peak'] = getid3_lib::CastAsInt(round($thisfile_mpc_header['max_level'] * 1.18)); // why? I don't know - see mppdec.c
312 }
313 if ($thisfile_mpc_header['album_peak'] > 0) {
314 $info['replay_gain']['album']['peak'] = $thisfile_mpc_header['album_peak'];
315 }
316
317 //$info['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_version_major'].'.'.$thisfile_mpc_header['stream_version_minor'].', '.$thisfile_mpc_header['encoder_version'];
318 $info['audio']['encoder'] = $thisfile_mpc_header['encoder_version'];
319 $info['audio']['encoder_options'] = $thisfile_mpc_header['profile'];
320 $thisfile_mpc_header['quality'] = (float) ($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
321
322 return true;
323 }

References $info, getid3_lib\CastAsInt(), getid3_handler\fread(), getid3_lib\LittleEndian2Int(), MPCencoderVersionLookup(), MPCfrequencyLookup(), MPCpeakDBLookup(), and MPCprofileNameLookup().

Referenced by Analyze().

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◆ ParseMPCsv8()

getid3_mpc::ParseMPCsv8 ( )

Definition at line 63 of file module.audio.mpc.php.

63 {
64 // this is SV8
65 // http://trac.musepack.net/trac/wiki/SV8Specification
66
67 $info = &$this->getid3->info;
68 $thisfile_mpc_header = &$info['mpc']['header'];
69
70 $keyNameSize = 2;
71 $maxHandledPacketLength = 9; // specs say: "n*8; 0 < n < 10"
72
73 $offset = $this->ftell();
74 while ($offset < $info['avdataend']) {
75 $thisPacket = array();
76 $thisPacket['offset'] = $offset;
77 $packet_offset = 0;
78
79 // Size is a variable-size field, could be 1-4 bytes (possibly more?)
80 // read enough data in and figure out the exact size later
81 $MPCheaderData = $this->fread($keyNameSize + $maxHandledPacketLength);
82 $packet_offset += $keyNameSize;
83 $thisPacket['key'] = substr($MPCheaderData, 0, $keyNameSize);
84 $thisPacket['key_name'] = $this->MPCsv8PacketName($thisPacket['key']);
85 if ($thisPacket['key'] == $thisPacket['key_name']) {
86 $info['error'][] = 'Found unexpected key value "'.$thisPacket['key'].'" at offset '.$thisPacket['offset'];
87 return false;
88 }
89 $packetLength = 0;
90 $thisPacket['packet_size'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $keyNameSize), $packetLength); // includes keyname and packet_size field
91 if ($thisPacket['packet_size'] === false) {
92 $info['error'][] = 'Did not find expected packet length within '.$maxHandledPacketLength.' bytes at offset '.($thisPacket['offset'] + $keyNameSize);
93 return false;
94 }
95 $packet_offset += $packetLength;
96 $offset += $thisPacket['packet_size'];
97
98 switch ($thisPacket['key']) {
99 case 'SH': // Stream Header
100 $moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength;
101 if ($moreBytesToRead > 0) {
102 $MPCheaderData .= $this->fread($moreBytesToRead);
103 }
104 $thisPacket['crc'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 4));
105 $packet_offset += 4;
106 $thisPacket['stream_version'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
107 $packet_offset += 1;
108
109 $packetLength = 0;
110 $thisPacket['sample_count'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength);
111 $packet_offset += $packetLength;
112
113 $packetLength = 0;
114 $thisPacket['beginning_silence'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength);
115 $packet_offset += $packetLength;
116
117 $otherUsefulData = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
118 $packet_offset += 2;
119 $thisPacket['sample_frequency_raw'] = (($otherUsefulData & 0xE000) >> 13);
120 $thisPacket['max_bands_used'] = (($otherUsefulData & 0x1F00) >> 8);
121 $thisPacket['channels'] = (($otherUsefulData & 0x00F0) >> 4) + 1;
122 $thisPacket['ms_used'] = (bool) (($otherUsefulData & 0x0008) >> 3);
123 $thisPacket['audio_block_frames'] = (($otherUsefulData & 0x0007) >> 0);
124 $thisPacket['sample_frequency'] = $this->MPCfrequencyLookup($thisPacket['sample_frequency_raw']);
125
126 $thisfile_mpc_header['mid_side_stereo'] = $thisPacket['ms_used'];
127 $thisfile_mpc_header['sample_rate'] = $thisPacket['sample_frequency'];
128 $thisfile_mpc_header['samples'] = $thisPacket['sample_count'];
129 $thisfile_mpc_header['stream_version_major'] = $thisPacket['stream_version'];
130
131 $info['audio']['channels'] = $thisPacket['channels'];
132 $info['audio']['sample_rate'] = $thisPacket['sample_frequency'];
133 $info['playtime_seconds'] = $thisPacket['sample_count'] / $thisPacket['sample_frequency'];
134 $info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
135 break;
136
137 case 'RG': // Replay Gain
138 $moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength;
139 if ($moreBytesToRead > 0) {
140 $MPCheaderData .= $this->fread($moreBytesToRead);
141 }
142 $thisPacket['replaygain_version'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
143 $packet_offset += 1;
144 $thisPacket['replaygain_title_gain'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
145 $packet_offset += 2;
146 $thisPacket['replaygain_title_peak'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
147 $packet_offset += 2;
148 $thisPacket['replaygain_album_gain'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
149 $packet_offset += 2;
150 $thisPacket['replaygain_album_peak'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
151 $packet_offset += 2;
152
153 if ($thisPacket['replaygain_title_gain']) { $info['replay_gain']['title']['gain'] = $thisPacket['replaygain_title_gain']; }
154 if ($thisPacket['replaygain_title_peak']) { $info['replay_gain']['title']['peak'] = $thisPacket['replaygain_title_peak']; }
155 if ($thisPacket['replaygain_album_gain']) { $info['replay_gain']['album']['gain'] = $thisPacket['replaygain_album_gain']; }
156 if ($thisPacket['replaygain_album_peak']) { $info['replay_gain']['album']['peak'] = $thisPacket['replaygain_album_peak']; }
157 break;
158
159 case 'EI': // Encoder Info
160 $moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength;
161 if ($moreBytesToRead > 0) {
162 $MPCheaderData .= $this->fread($moreBytesToRead);
163 }
164 $profile_pns = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
165 $packet_offset += 1;
166 $quality_int = (($profile_pns & 0xF0) >> 4);
167 $quality_dec = (($profile_pns & 0x0E) >> 3);
168 $thisPacket['quality'] = (float) $quality_int + ($quality_dec / 8);
169 $thisPacket['pns_tool'] = (bool) (($profile_pns & 0x01) >> 0);
170 $thisPacket['version_major'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
171 $packet_offset += 1;
172 $thisPacket['version_minor'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
173 $packet_offset += 1;
174 $thisPacket['version_build'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
175 $packet_offset += 1;
176 $thisPacket['version'] = $thisPacket['version_major'].'.'.$thisPacket['version_minor'].'.'.$thisPacket['version_build'];
177
178 $info['audio']['encoder'] = 'MPC v'.$thisPacket['version'].' ('.(($thisPacket['version_minor'] % 2) ? 'unstable' : 'stable').')';
179 $thisfile_mpc_header['encoder_version'] = $info['audio']['encoder'];
180 //$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
181 $thisfile_mpc_header['quality'] = (float) ($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
182 break;
183
184 case 'SO': // Seek Table Offset
185 $packetLength = 0;
186 $thisPacket['seek_table_offset'] = $thisPacket['offset'] + $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength);
187 $packet_offset += $packetLength;
188 break;
189
190 case 'ST': // Seek Table
191 case 'SE': // Stream End
192 case 'AP': // Audio Data
193 // nothing useful here, just skip this packet
194 $thisPacket = array();
195 break;
196
197 default:
198 $info['error'][] = 'Found unhandled key type "'.$thisPacket['key'].'" at offset '.$thisPacket['offset'];
199 return false;
200 break;
201 }
202 if (!empty($thisPacket)) {
203 $info['mpc']['packets'][] = $thisPacket;
204 }
205 $this->fseek($offset);
206 }
207 $thisfile_mpc_header['size'] = $offset;
208 return true;
209 }
getid3_handler\ftell
ftell()
Definition: getid3.php:1678
getid3_lib\BigEndian2Int
BigEndian2Int($byteword, $synchsafe=false, $signed=false)
Definition: getid3.lib.php:234
getid3_mpc\SV8variableLengthInteger
SV8variableLengthInteger($data, &$packetLength, $maxHandledPacketLength=9)
Definition: module.audio.mpc.php:467
getid3_mpc\MPCsv8PacketName
MPCsv8PacketName($packetKey)
Definition: module.audio.mpc.php:491

References $info, getid3_lib\BigEndian2Int(), getid3_handler\fread(), getid3_handler\fseek(), getid3_handler\ftell(), MPCfrequencyLookup(), MPCsv8PacketName(), and SV8variableLengthInteger().

Referenced by Analyze().

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◆ SV8variableLengthInteger()

getid3_mpc::SV8variableLengthInteger (   $data,
&  $packetLength,
  $maxHandledPacketLength = 9 
)

Definition at line 467 of file module.audio.mpc.php.

467 {
468 $packet_size = 0;
469 for ($packetLength = 1; $packetLength <= $maxHandledPacketLength; $packetLength++) {
470 // variable-length size field:
471 // bits, big-endian
472 // 0xxx xxxx - value 0 to 2^7-1
473 // 1xxx xxxx 0xxx xxxx - value 0 to 2^14-1
474 // 1xxx xxxx 1xxx xxxx 0xxx xxxx - value 0 to 2^21-1
475 // 1xxx xxxx 1xxx xxxx 1xxx xxxx 0xxx xxxx - value 0 to 2^28-1
476 // ...
477 $thisbyte = ord(substr($data, ($packetLength - 1), 1));
478 // look through bytes until find a byte with MSB==0
479 $packet_size = ($packet_size << 7);
480 $packet_size = ($packet_size | ($thisbyte & 0x7F));
481 if (($thisbyte & 0x80) === 0) {
482 break;
483 }
484 if ($packetLength >= $maxHandledPacketLength) {
485 return false;
486 }
487 }
488 return $packet_size;
489 }
$data
$data
Definition: example_011.php:126

References $data.

Referenced by ParseMPCsv8().

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The documentation for this class was generated from the following files: