1<?php
2
3/////////////////////////////////////////////////////////////////
4/// getID3() by James Heinrich <info@getid3.org>               //
5//  available at https://github.com/JamesHeinrich/getID3       //
6//            or https://www.getid3.org                        //
7//            or http://getid3.sourceforge.net                 //
8//  see readme.txt for more details                            //
9/////////////////////////////////////////////////////////////////
10//                                                             //
11// module.audio.tta.php                                        //
12// module for analyzing TTA Audio files                        //
13// dependencies: NONE                                          //
14//                                                            ///
15/////////////////////////////////////////////////////////////////
16
17if (!defined('GETID3_INCLUDEPATH')) { // prevent path-exposing attacks that access modules directly on public webservers
18	exit;
19}
20
21class getid3_tta extends getid3_handler
22{
23	/**
24	 * @return bool
25	 */
26	public function Analyze() {
27		$info = &$this->getid3->info;
28
29		$info['fileformat']            = 'tta';
30		$info['audio']['dataformat']   = 'tta';
31		$info['audio']['lossless']     = true;
32		$info['audio']['bitrate_mode'] = 'vbr';
33
34		$this->fseek($info['avdataoffset']);
35		$ttaheader = $this->fread(26);
36
37		$info['tta']['magic'] = substr($ttaheader, 0, 3);
38		$magic = 'TTA';
39		if ($info['tta']['magic'] != $magic) {
40			$this->error('Expecting "'.getid3_lib::PrintHexBytes($magic).'" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes($info['tta']['magic']).'"');
41			unset($info['fileformat']);
42			unset($info['audio']);
43			unset($info['tta']);
44			return false;
45		}
46
47		switch ($ttaheader[3]) {
48			case "\x01": // TTA v1.x
49			case "\x02": // TTA v1.x
50			case "\x03": // TTA v1.x
51				// "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."
52				$info['tta']['major_version'] = 1;
53				$info['avdataoffset'] += 16;
54
55				$info['tta']['compression_level']   = ord($ttaheader[3]);
56				$info['tta']['channels']            = getid3_lib::LittleEndian2Int(substr($ttaheader,  4,  2));
57				$info['tta']['bits_per_sample']     = getid3_lib::LittleEndian2Int(substr($ttaheader,  6,  2));
58				$info['tta']['sample_rate']         = getid3_lib::LittleEndian2Int(substr($ttaheader,  8,  4));
59				$info['tta']['samples_per_channel'] = getid3_lib::LittleEndian2Int(substr($ttaheader, 12,  4));
60
61				$info['audio']['encoder_options']   = '-e'.$info['tta']['compression_level'];
62				$info['playtime_seconds']           = $info['tta']['samples_per_channel'] / $info['tta']['sample_rate'];
63				break;
64
65			case '2': // TTA v2.x
66				// "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."
67				$info['tta']['major_version'] = 2;
68				$info['avdataoffset'] += 20;
69
70				$info['tta']['compression_level']   = getid3_lib::LittleEndian2Int(substr($ttaheader,  4,  2));
71				$info['tta']['audio_format']        = getid3_lib::LittleEndian2Int(substr($ttaheader,  6,  2));
72				$info['tta']['channels']            = getid3_lib::LittleEndian2Int(substr($ttaheader,  8,  2));
73				$info['tta']['bits_per_sample']     = getid3_lib::LittleEndian2Int(substr($ttaheader, 10,  2));
74				$info['tta']['sample_rate']         = getid3_lib::LittleEndian2Int(substr($ttaheader, 12,  4));
75				$info['tta']['data_length']         = getid3_lib::LittleEndian2Int(substr($ttaheader, 16,  4));
76
77				$info['audio']['encoder_options']   = '-e'.$info['tta']['compression_level'];
78				$info['playtime_seconds']           = $info['tta']['data_length'] / $info['tta']['sample_rate'];
79				break;
80
81			case '1': // TTA v3.x
82				// "This is a first stable release of the TTA format. It will be supported by the encoders v3 or higher."
83				$info['tta']['major_version'] = 3;
84				$info['avdataoffset'] += 26;
85
86				$info['tta']['audio_format']        = getid3_lib::LittleEndian2Int(substr($ttaheader,  4,  2)); // getid3_riff::wFormatTagLookup()
87				$info['tta']['channels']            = getid3_lib::LittleEndian2Int(substr($ttaheader,  6,  2));
88				$info['tta']['bits_per_sample']     = getid3_lib::LittleEndian2Int(substr($ttaheader,  8,  2));
89				$info['tta']['sample_rate']         = getid3_lib::LittleEndian2Int(substr($ttaheader, 10,  4));
90				$info['tta']['data_length']         = getid3_lib::LittleEndian2Int(substr($ttaheader, 14,  4));
91				$info['tta']['crc32_footer']        =                              substr($ttaheader, 18,  4);
92				$info['tta']['seek_point']          = getid3_lib::LittleEndian2Int(substr($ttaheader, 22,  4));
93
94				$info['playtime_seconds']           = $info['tta']['data_length'] / $info['tta']['sample_rate'];
95				break;
96
97			default:
98				$this->error('This version of getID3() ['.$this->getid3->version().'] 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]);
99				return false;
100		}
101
102		$info['audio']['encoder']         = 'TTA v'.$info['tta']['major_version'];
103		$info['audio']['bits_per_sample'] = $info['tta']['bits_per_sample'];
104		$info['audio']['sample_rate']     = $info['tta']['sample_rate'];
105		$info['audio']['channels']        = $info['tta']['channels'];
106		$info['audio']['bitrate']         = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
107
108		return true;
109	}
110
111}
112