ILIAS  eassessment Revision 61809
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module.audio.tta.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.tta.php //
11 // module for analyzing TTA Audio files //
12 // dependencies: NONE //
13 // ///
15 
16 
17 class getid3_tta
18 {
19 
20  function getid3_tta(&$fd, &$ThisFileInfo) {
21 
22  $ThisFileInfo['fileformat'] = 'tta';
23  $ThisFileInfo['audio']['dataformat'] = 'tta';
24  $ThisFileInfo['audio']['lossless'] = true;
25  $ThisFileInfo['audio']['bitrate_mode'] = 'vbr';
26 
27  fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);
28  $ttaheader = fread($fd, 26);
29 
30  $ThisFileInfo['tta']['magic'] = substr($ttaheader, 0, 3);
31  if ($ThisFileInfo['tta']['magic'] != 'TTA') {
32  $ThisFileInfo['error'][] = 'Expecting "TTA" at offset '.$ThisFileInfo['avdataoffset'].', found "'.$ThisFileInfo['tta']['magic'].'"';
33  unset($ThisFileInfo['fileformat']);
34  unset($ThisFileInfo['audio']);
35  unset($ThisFileInfo['tta']);
36  return false;
37  }
38 
39  switch ($ttaheader{3}) {
40  case "\x01": // TTA v1.x
41  case "\x02": // TTA v1.x
42  case "\x03": // TTA v1.x
43  // "It was the demo-version of the TTA encoder. There is no released format with such header. TTA encoder v1 is not supported about a year."
44  $ThisFileInfo['tta']['major_version'] = 1;
45  $ThisFileInfo['avdataoffset'] += 16;
46 
47  $ThisFileInfo['tta']['compression_level'] = ord($ttaheader{3});
48  $ThisFileInfo['tta']['channels'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 4, 2));
49  $ThisFileInfo['tta']['bits_per_sample'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 6, 2));
50  $ThisFileInfo['tta']['sample_rate'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 8, 4));
51  $ThisFileInfo['tta']['samples_per_channel'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 12, 4));
52 
53  $ThisFileInfo['audio']['encoder_options'] = '-e'.$ThisFileInfo['tta']['compression_level'];
54  $ThisFileInfo['playtime_seconds'] = $ThisFileInfo['tta']['samples_per_channel'] / $ThisFileInfo['tta']['sample_rate'];
55  break;
56 
57  case '2': // TTA v2.x
58  // "I have hurried to release the TTA 2.0 encoder. Format documentation is removed from our site. This format still in development. Please wait the TTA2 format, encoder v4."
59  $ThisFileInfo['tta']['major_version'] = 2;
60  $ThisFileInfo['avdataoffset'] += 20;
61 
62  $ThisFileInfo['tta']['compression_level'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 4, 2));
63  $ThisFileInfo['tta']['audio_format'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 6, 2));
64  $ThisFileInfo['tta']['channels'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 8, 2));
65  $ThisFileInfo['tta']['bits_per_sample'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 10, 2));
66  $ThisFileInfo['tta']['sample_rate'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 12, 4));
67  $ThisFileInfo['tta']['data_length'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 16, 4));
68 
69  $ThisFileInfo['audio']['encoder_options'] = '-e'.$ThisFileInfo['tta']['compression_level'];
70  $ThisFileInfo['playtime_seconds'] = $ThisFileInfo['tta']['data_length'] / $ThisFileInfo['tta']['sample_rate'];
71  break;
72 
73  case '1': // TTA v3.x
74  // "This is a first stable release of the TTA format. It will be supported by the encoders v3 or higher."
75  $ThisFileInfo['tta']['major_version'] = 3;
76  $ThisFileInfo['avdataoffset'] += 26;
77 
78  $ThisFileInfo['tta']['audio_format'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 4, 2)); // getid3_riff::RIFFwFormatTagLookup()
79  $ThisFileInfo['tta']['channels'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 6, 2));
80  $ThisFileInfo['tta']['bits_per_sample'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 8, 2));
81  $ThisFileInfo['tta']['sample_rate'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 10, 4));
82  $ThisFileInfo['tta']['data_length'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 14, 4));
83  $ThisFileInfo['tta']['crc32_footer'] = substr($ttaheader, 18, 4);
84  $ThisFileInfo['tta']['seek_point'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 22, 4));
85 
86  $ThisFileInfo['playtime_seconds'] = $ThisFileInfo['tta']['data_length'] / $ThisFileInfo['tta']['sample_rate'];
87  break;
88 
89  default:
90  $ThisFileInfo['error'][] = 'This version of getID3() only knows how to handle TTA v1 and v2 - it may not work correctly with this file which appears to be TTA v'.$ttaheader{3};
91  return false;
92  break;
93  }
94 
95  $ThisFileInfo['audio']['encoder'] = 'TTA v'.$ThisFileInfo['tta']['major_version'];
96  $ThisFileInfo['audio']['bits_per_sample'] = $ThisFileInfo['tta']['bits_per_sample'];
97  $ThisFileInfo['audio']['sample_rate'] = $ThisFileInfo['tta']['sample_rate'];
98  $ThisFileInfo['audio']['channels'] = $ThisFileInfo['tta']['channels'];
99  $ThisFileInfo['audio']['bitrate'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / $ThisFileInfo['playtime_seconds'];
100 
101  return true;
102  }
103 
104 }
105 
106 
107 ?>