ILIAS  release_5-2 Revision v5.2.25-18-g3f80b82851
Rkau.php
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1 <?php
2 
3 namespace GetId3\Module\Audio;
4 
7 
10 // available at http://getid3.sourceforge.net //
11 // or http://www.getid3.org //
13 // See readme.txt for more details //
15 // //
16 // module.audio.shorten.php //
17 // module for analyzing Shorten Audio files //
18 // dependencies: NONE //
19 // ///
21 
29 class Rkau extends BaseHandler
30 {
31 
36  public function analyze()
37  {
38  $info = &$this->getid3->info;
39 
40  fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
41  $RKAUHeader = fread($this->getid3->fp, 20);
42  $magic = 'RKA';
43  if (substr($RKAUHeader, 0, 3) != $magic) {
44  $info['error'][] = 'Expecting "'.Helper::PrintHexBytes($magic).'" at offset '.$info['avdataoffset'].', found "'.Helper::PrintHexBytes(substr($RKAUHeader, 0, 3)).'"';
45 
46  return false;
47  }
48 
49  $info['fileformat'] = 'rkau';
50  $info['audio']['dataformat'] = 'rkau';
51  $info['audio']['bitrate_mode'] = 'vbr';
52 
53  $info['rkau']['raw']['version'] = Helper::LittleEndian2Int(substr($RKAUHeader, 3, 1));
54  $info['rkau']['version'] = '1.'.str_pad($info['rkau']['raw']['version'] & 0x0F, 2, '0', STR_PAD_LEFT);
55  if (($info['rkau']['version'] > 1.07) || ($info['rkau']['version'] < 1.06)) {
56  $info['error'][] = 'This version of GetId3Core() ['.$this->getid3->version().'] can only parse RKAU files v1.06 and 1.07 (this file is v'.$info['rkau']['version'].')';
57  unset($info['rkau']);
58 
59  return false;
60  }
61 
62  $info['rkau']['source_bytes'] = Helper::LittleEndian2Int(substr($RKAUHeader, 4, 4));
63  $info['rkau']['sample_rate'] = Helper::LittleEndian2Int(substr($RKAUHeader, 8, 4));
64  $info['rkau']['channels'] = Helper::LittleEndian2Int(substr($RKAUHeader, 12, 1));
65  $info['rkau']['bits_per_sample'] = Helper::LittleEndian2Int(substr($RKAUHeader, 13, 1));
66 
67  $info['rkau']['raw']['quality'] = Helper::LittleEndian2Int(substr($RKAUHeader, 14, 1));
68  $this->RKAUqualityLookup($info['rkau']);
69 
70  $info['rkau']['raw']['flags'] = Helper::LittleEndian2Int(substr($RKAUHeader, 15, 1));
71  $info['rkau']['flags']['joint_stereo'] = (bool) (!($info['rkau']['raw']['flags'] & 0x01));
72  $info['rkau']['flags']['streaming'] = (bool) ($info['rkau']['raw']['flags'] & 0x02);
73  $info['rkau']['flags']['vrq_lossy_mode'] = (bool) ($info['rkau']['raw']['flags'] & 0x04);
74 
75  if ($info['rkau']['flags']['streaming']) {
76  $info['avdataoffset'] += 20;
77  $info['rkau']['compressed_bytes'] = Helper::LittleEndian2Int(substr($RKAUHeader, 16, 4));
78  } else {
79  $info['avdataoffset'] += 16;
80  $info['rkau']['compressed_bytes'] = $info['avdataend'] - $info['avdataoffset'] - 1;
81  }
82  // Note: compressed_bytes does not always equal what appears to be the actual number of compressed bytes,
83  // sometimes it's more, sometimes less. No idea why(?)
84 
85  $info['audio']['lossless'] = $info['rkau']['lossless'];
86  $info['audio']['channels'] = $info['rkau']['channels'];
87  $info['audio']['bits_per_sample'] = $info['rkau']['bits_per_sample'];
88  $info['audio']['sample_rate'] = $info['rkau']['sample_rate'];
89 
90  $info['playtime_seconds'] = $info['rkau']['source_bytes'] / ($info['rkau']['sample_rate'] * $info['rkau']['channels'] * ($info['rkau']['bits_per_sample'] / 8));
91  $info['audio']['bitrate'] = ($info['rkau']['compressed_bytes'] * 8) / $info['playtime_seconds'];
92 
93  return true;
94 
95  }
96 
102  public function RKAUqualityLookup(&$RKAUdata)
103  {
104  $level = ($RKAUdata['raw']['quality'] & 0xF0) >> 4;
105  $quality = $RKAUdata['raw']['quality'] & 0x0F;
106 
107  $RKAUdata['lossless'] = (($quality == 0) ? true : false);
108  $RKAUdata['compression_level'] = $level + 1;
109  if (!$RKAUdata['lossless']) {
110  $RKAUdata['quality_setting'] = $quality;
111  }
112 
113  return true;
114  }
115 
116 }
static PrintHexBytes($string, $hex=true, $spaces=true, $htmlencoding='UTF-8')
Definition: Helper.php:36
GetId3() by James Heinrich info@getid3.org //.
Definition: BaseHandler.php:25
fseek($bytes, $whence=SEEK_SET)
$info
Definition: example_052.php:80
GetId3() by James Heinrich info@getid3.org //.
Definition: Rkau.php:29
RKAUqualityLookup(&$RKAUdata)
Definition: Rkau.php:102
static LittleEndian2Int($byteword, $signed=false)
Definition: Helper.php:413