ILIAS  release_5-3 Revision v5.3.23-19-g915713cf615
module.audio.dss.php
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1 <?php
4 // available at http://getid3.sourceforge.net //
5 // or http://www.getid3.org //
6 // also https://github.com/JamesHeinrich/getID3 //
8 // See readme.txt for more details //
10 // //
11 // module.audio.dss.php //
12 // module for analyzing Digital Speech Standard (DSS) files //
13 // dependencies: NONE //
14 // ///
16 
17 
19 {
20 
21  public function Analyze() {
22  $info = &$this->getid3->info;
23 
24  $this->fseek($info['avdataoffset']);
25  $DSSheader = $this->fread(1540);
26 
27  if (!preg_match('#^[\\x02-\\x06]ds[s2]#', $DSSheader)) {
28  $this->error('Expecting "[02-06] 64 73 [73|32]" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes(substr($DSSheader, 0, 4)).'"');
29  return false;
30  }
31 
32  // some structure information taken from http://cpansearch.perl.org/src/RGIBSON/Audio-DSS-0.02/lib/Audio/DSS.pm
33  $info['encoding'] = 'ISO-8859-1'; // not certain, but assumed
34  $info['dss'] = array();
35 
36  $info['fileformat'] = 'dss';
37  $info['mime_type'] = 'audio/x-'.substr($DSSheader, 1, 3); // "audio/x-dss" or "audio/x-ds2"
38  $info['audio']['dataformat'] = substr($DSSheader, 1, 3); // "dss" or "ds2"
39  $info['audio']['bitrate_mode'] = 'cbr';
40 
41  $info['dss']['version'] = ord(substr($DSSheader, 0, 1));
42  $info['dss']['hardware'] = trim(substr($DSSheader, 12, 16)); // identification string for hardware used to create the file, e.g. "DPM 9600", "DS2400"
43  $info['dss']['unknown1'] = getid3_lib::LittleEndian2Int(substr($DSSheader, 28, 4));
44  // 32-37 = "FE FF FE FF F7 FF" in all the sample files I've seen
45  $info['dss']['date_create_unix'] = $this->DSSdateStringToUnixDate(substr($DSSheader, 38, 12));
46  $info['dss']['date_complete_unix'] = $this->DSSdateStringToUnixDate(substr($DSSheader, 50, 12));
47  $info['dss']['playtime_sec'] = intval((substr($DSSheader, 62, 2) * 3600) + (substr($DSSheader, 64, 2) * 60) + substr($DSSheader, 66, 2)); // approximate file playtime in HHMMSS
48  if ($info['dss']['version'] <= 3) {
49  $info['dss']['playtime_ms'] = getid3_lib::LittleEndian2Int(substr($DSSheader, 512, 4)); // exact file playtime in milliseconds. Has also been observed at offset 530 in one sample file, with something else (unknown) at offset 512
50  $info['dss']['priority'] = ord(substr($DSSheader, 793, 1));
51  $info['dss']['comments'] = trim(substr($DSSheader, 798, 100));
52  $info['dss']['sample_rate_index'] = ord(substr($DSSheader, 1538, 1)); // this isn't certain, this may or may not be where the sample rate info is stored, but it seems consistent on my small selection of sample files
53  $info['audio']['sample_rate'] = $this->DSSsampleRateLookup($info['dss']['sample_rate_index']);
54  } else {
55  $this->getid3->warning('DSS above version 3 not fully supported in this version of getID3. Any additional documentation or format specifications would be welcome. This file is version '.$info['dss']['version']);
56  }
57 
58  $info['audio']['bits_per_sample'] = 16; // maybe, maybe not -- most compressed audio formats don't have a fixed bits-per-sample value, but this is a reasonable approximation
59  $info['audio']['channels'] = 1;
60 
61  if (!empty($info['dss']['playtime_ms']) && (floor($info['dss']['playtime_ms'] / 1000) == $info['dss']['playtime_sec'])) { // *should* just be playtime_ms / 1000 but at least one sample file has playtime_ms at offset 530 instead of offset 512, so safety check
62  $info['playtime_seconds'] = $info['dss']['playtime_ms'] / 1000;
63  } else {
64  $info['playtime_seconds'] = $info['dss']['playtime_sec'];
65  if (!empty($info['dss']['playtime_ms'])) {
66  $this->getid3->warning('playtime_ms ('.number_format($info['dss']['playtime_ms'] / 1000, 3).') does not match playtime_sec ('.number_format($info['dss']['playtime_sec']).') - using playtime_sec value');
67  }
68  }
69  $info['audio']['bitrate'] = ($info['filesize'] * 8) / $info['playtime_seconds'];
70 
71  return true;
72  }
73 
74  public function DSSdateStringToUnixDate($datestring) {
75  $y = substr($datestring, 0, 2);
76  $m = substr($datestring, 2, 2);
77  $d = substr($datestring, 4, 2);
78  $h = substr($datestring, 6, 2);
79  $i = substr($datestring, 8, 2);
80  $s = substr($datestring, 10, 2);
81  $y += (($y < 95) ? 2000 : 1900);
82  return mktime($h, $i, $s, $m, $d, $y);
83  }
84 
85  public function DSSsampleRateLookup($sample_rate_index) {
86  static $dssSampleRateLookup = array(
87  0x0A => 16000,
88  0x0C => 11025,
89  0x0D => 12000,
90  0x15 => 8000,
91  );
92  if (!array_key_exists($sample_rate_index, $dssSampleRateLookup)) {
93  $this->getid3->warning('unknown sample_rate_index: 0x'.strtoupper(dechex($sample_rate_index)));
94  return false;
95  }
96  return $dssSampleRateLookup[$sample_rate_index];
97  }
98 
99 }
$h
error($text)
Definition: getid3.php:1752
$s
Definition: pwgen.php:45
static LittleEndian2Int($byteword, $signed=false)
Definition: getid3.lib.php:292
$y
Definition: example_007.php:83
getID3() by James Heinrich info@getid3.org //
static PrintHexBytes($string, $hex=true, $spaces=true, $htmlencoding='UTF-8')
Definition: getid3.lib.php:18
fread($bytes)
Definition: getid3.php:1683
Create styles array
The data for the language used.
DSSdateStringToUnixDate($datestring)
$i
Definition: disco.tpl.php:19
fseek($bytes, $whence=SEEK_SET)
Definition: getid3.php:1711
$info
Definition: index.php:5
DSSsampleRateLookup($sample_rate_index)
for($i=6; $i< 13; $i++) for($i=1; $i< 13; $i++) $d
Definition: date.php:296