1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
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
59
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
|
<?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.lpac.php //
// module for analyzing LPAC Audio files //
// dependencies: module.audio-video.riff.php //
// ///
/////////////////////////////////////////////////////////////////
getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio-video.riff.php', __FILE__, true);
class getid3_lpac extends getid3_handler
{
function Analyze() {
$info = &$this->getid3->info;
fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
$LPACheader = fread($this->getid3->fp, 14);
if (substr($LPACheader, 0, 4) != 'LPAC') {
$info['error'][] = 'Expected "LPAC" at offset '.$info['avdataoffset'].', found "'.$StreamMarker.'"';
return false;
}
$info['avdataoffset'] += 14;
$info['fileformat'] = 'lpac';
$info['audio']['dataformat'] = 'lpac';
$info['audio']['lossless'] = true;
$info['audio']['bitrate_mode'] = 'vbr';
$info['lpac']['file_version'] = getid3_lib::BigEndian2Int(substr($LPACheader, 4, 1));
$flags['audio_type'] = getid3_lib::BigEndian2Int(substr($LPACheader, 5, 1));
$info['lpac']['total_samples']= getid3_lib::BigEndian2Int(substr($LPACheader, 6, 4));
$flags['parameters'] = getid3_lib::BigEndian2Int(substr($LPACheader, 10, 4));
$info['lpac']['flags']['is_wave'] = (bool) ($flags['audio_type'] & 0x40);
$info['lpac']['flags']['stereo'] = (bool) ($flags['audio_type'] & 0x04);
$info['lpac']['flags']['24_bit'] = (bool) ($flags['audio_type'] & 0x02);
$info['lpac']['flags']['16_bit'] = (bool) ($flags['audio_type'] & 0x01);
if ($info['lpac']['flags']['24_bit'] && $info['lpac']['flags']['16_bit']) {
$info['warning'][] = '24-bit and 16-bit flags cannot both be set';
}
$info['lpac']['flags']['fast_compress'] = (bool) ($flags['parameters'] & 0x40000000);
$info['lpac']['flags']['random_access'] = (bool) ($flags['parameters'] & 0x08000000);
$info['lpac']['block_length'] = pow(2, (($flags['parameters'] & 0x07000000) >> 24)) * 256;
$info['lpac']['flags']['adaptive_prediction_order'] = (bool) ($flags['parameters'] & 0x00800000);
$info['lpac']['flags']['adaptive_quantization'] = (bool) ($flags['parameters'] & 0x00400000);
$info['lpac']['flags']['joint_stereo'] = (bool) ($flags['parameters'] & 0x00040000);
$info['lpac']['quantization'] = ($flags['parameters'] & 0x00001F00) >> 8;
$info['lpac']['max_prediction_order'] = ($flags['parameters'] & 0x0000003F);
if ($info['lpac']['flags']['fast_compress'] && ($info['lpac']['max_prediction_order'] != 3)) {
$info['warning'][] = 'max_prediction_order expected to be "3" if fast_compress is true, actual value is "'.$info['lpac']['max_prediction_order'].'"';
}
switch ($info['lpac']['file_version']) {
case 6:
if ($info['lpac']['flags']['adaptive_quantization']) {
$info['warning'][] = 'adaptive_quantization expected to be false in LPAC file stucture v6, actually true';
}
if ($info['lpac']['quantization'] != 20) {
$info['warning'][] = 'Quantization expected to be 20 in LPAC file stucture v6, actually '.$info['lpac']['flags']['Q'];
}
break;
default:
//$info['warning'][] = 'This version of getID3() ['.$this->getid3->version().'] only supports LPAC file format version 6, this file is version '.$info['lpac']['file_version'].' - please report to info@getid3.org';
break;
}
$getid3_temp = new getID3();
$getid3_temp->openfile($this->getid3->filename);
$getid3_temp->info = $info;
$getid3_riff = new getid3_riff($getid3_temp);
$getid3_riff->Analyze();
$info['avdataoffset'] = $getid3_temp->info['avdataoffset'];
$info['riff'] = $getid3_temp->info['riff'];
$info['error'] = $getid3_temp->info['error'];
$info['warning'] = $getid3_temp->info['warning'];
$info['lpac']['comments']['comment'] = $getid3_temp->info['comments'];
$info['audio']['sample_rate'] = $getid3_temp->info['audio']['sample_rate'];
unset($getid3_temp, $getid3_riff);
$info['audio']['channels'] = ($info['lpac']['flags']['stereo'] ? 2 : 1);
if ($info['lpac']['flags']['24_bit']) {
$info['audio']['bits_per_sample'] = $info['riff']['audio'][0]['bits_per_sample'];
} elseif ($info['lpac']['flags']['16_bit']) {
$info['audio']['bits_per_sample'] = 16;
} else {
$info['audio']['bits_per_sample'] = 8;
}
if ($info['lpac']['flags']['fast_compress']) {
// fast
$info['audio']['encoder_options'] = '-1';
} else {
switch ($info['lpac']['max_prediction_order']) {
case 20: // simple
$info['audio']['encoder_options'] = '-2';
break;
case 30: // medium
$info['audio']['encoder_options'] = '-3';
break;
case 40: // high
$info['audio']['encoder_options'] = '-4';
break;
case 60: // extrahigh
$info['audio']['encoder_options'] = '-5';
break;
}
}
$info['playtime_seconds'] = $info['lpac']['total_samples'] / $info['audio']['sample_rate'];
$info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
return true;
}
}
?>
|
