1 | <?php |
---|
2 | ///////////////////////////////////////////////////////////////// |
---|
3 | /// getID3() by James Heinrich <info@getid3.org> // |
---|
4 | // available at http://getid3.sourceforge.net // |
---|
5 | // or http://www.getid3.org // |
---|
6 | ///////////////////////////////////////////////////////////////// |
---|
7 | // See readme.txt for more details // |
---|
8 | ///////////////////////////////////////////////////////////////// |
---|
9 | // // |
---|
10 | // module.audio.lpac.php // |
---|
11 | // module for analyzing LPAC Audio files // |
---|
12 | // dependencies: module.audio-video.riff.php // |
---|
13 | // /// |
---|
14 | ///////////////////////////////////////////////////////////////// |
---|
15 | |
---|
16 | getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio-video.riff.php', __FILE__, true); |
---|
17 | |
---|
18 | class getid3_lpac |
---|
19 | { |
---|
20 | |
---|
21 | function getid3_lpac(&$fd, &$ThisFileInfo) { |
---|
22 | |
---|
23 | fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET); |
---|
24 | $LPACheader = fread($fd, 14); |
---|
25 | if (substr($LPACheader, 0, 4) != 'LPAC') { |
---|
26 | $ThisFileInfo['error'][] = 'Expected "LPAC" at offset '.$ThisFileInfo['avdataoffset'].', found "'.$StreamMarker.'"'; |
---|
27 | return false; |
---|
28 | } |
---|
29 | $ThisFileInfo['avdataoffset'] += 14; |
---|
30 | |
---|
31 | $ThisFileInfo['fileformat'] = 'lpac'; |
---|
32 | $ThisFileInfo['audio']['dataformat'] = 'lpac'; |
---|
33 | $ThisFileInfo['audio']['lossless'] = true; |
---|
34 | $ThisFileInfo['audio']['bitrate_mode'] = 'vbr'; |
---|
35 | |
---|
36 | $ThisFileInfo['lpac']['file_version'] = getid3_lib::BigEndian2Int(substr($LPACheader, 4, 1)); |
---|
37 | $flags['audio_type'] = getid3_lib::BigEndian2Int(substr($LPACheader, 5, 1)); |
---|
38 | $ThisFileInfo['lpac']['total_samples']= getid3_lib::BigEndian2Int(substr($LPACheader, 6, 4)); |
---|
39 | $flags['parameters'] = getid3_lib::BigEndian2Int(substr($LPACheader, 10, 4)); |
---|
40 | |
---|
41 | $ThisFileInfo['lpac']['flags']['is_wave'] = (bool) ($flags['audio_type'] & 0x40); |
---|
42 | $ThisFileInfo['lpac']['flags']['stereo'] = (bool) ($flags['audio_type'] & 0x04); |
---|
43 | $ThisFileInfo['lpac']['flags']['24_bit'] = (bool) ($flags['audio_type'] & 0x02); |
---|
44 | $ThisFileInfo['lpac']['flags']['16_bit'] = (bool) ($flags['audio_type'] & 0x01); |
---|
45 | |
---|
46 | if ($ThisFileInfo['lpac']['flags']['24_bit'] && $ThisFileInfo['lpac']['flags']['16_bit']) { |
---|
47 | $ThisFileInfo['warning'][] = '24-bit and 16-bit flags cannot both be set'; |
---|
48 | } |
---|
49 | |
---|
50 | $ThisFileInfo['lpac']['flags']['fast_compress'] = (bool) ($flags['parameters'] & 0x40000000); |
---|
51 | $ThisFileInfo['lpac']['flags']['random_access'] = (bool) ($flags['parameters'] & 0x08000000); |
---|
52 | $ThisFileInfo['lpac']['block_length'] = pow(2, (($flags['parameters'] & 0x07000000) >> 24)) * 256; |
---|
53 | $ThisFileInfo['lpac']['flags']['adaptive_prediction_order'] = (bool) ($flags['parameters'] & 0x00800000); |
---|
54 | $ThisFileInfo['lpac']['flags']['adaptive_quantization'] = (bool) ($flags['parameters'] & 0x00400000); |
---|
55 | $ThisFileInfo['lpac']['flags']['joint_stereo'] = (bool) ($flags['parameters'] & 0x00040000); |
---|
56 | $ThisFileInfo['lpac']['quantization'] = ($flags['parameters'] & 0x00001F00) >> 8; |
---|
57 | $ThisFileInfo['lpac']['max_prediction_order'] = ($flags['parameters'] & 0x0000003F); |
---|
58 | |
---|
59 | if ($ThisFileInfo['lpac']['flags']['fast_compress'] && ($ThisFileInfo['lpac']['max_prediction_order'] != 3)) { |
---|
60 | $ThisFileInfo['warning'][] = 'max_prediction_order expected to be "3" if fast_compress is true, actual value is "'.$ThisFileInfo['lpac']['max_prediction_order'].'"'; |
---|
61 | } |
---|
62 | switch ($ThisFileInfo['lpac']['file_version']) { |
---|
63 | case 6: |
---|
64 | if ($ThisFileInfo['lpac']['flags']['adaptive_quantization']) { |
---|
65 | $ThisFileInfo['warning'][] = 'adaptive_quantization expected to be false in LPAC file stucture v6, actually true'; |
---|
66 | } |
---|
67 | if ($ThisFileInfo['lpac']['quantization'] != 20) { |
---|
68 | $ThisFileInfo['warning'][] = 'Quantization expected to be 20 in LPAC file stucture v6, actually '.$ThisFileInfo['lpac']['flags']['Q']; |
---|
69 | } |
---|
70 | break; |
---|
71 | |
---|
72 | default: |
---|
73 | //$ThisFileInfo['warning'][] = 'This version of getID3() only supports LPAC file format version 6, this file is version '.$ThisFileInfo['lpac']['file_version'].' - please report to info@getid3.org'; |
---|
74 | break; |
---|
75 | } |
---|
76 | |
---|
77 | $dummy = $ThisFileInfo; |
---|
78 | $riff = new getid3_riff($fd, $dummy); |
---|
79 | unset($riff); |
---|
80 | $ThisFileInfo['avdataoffset'] = $dummy['avdataoffset']; |
---|
81 | $ThisFileInfo['riff'] = $dummy['riff']; |
---|
82 | $ThisFileInfo['error'] = $dummy['error']; |
---|
83 | $ThisFileInfo['warning'] = $dummy['warning']; |
---|
84 | $ThisFileInfo['lpac']['comments']['comment'] = $dummy['comments']; |
---|
85 | $ThisFileInfo['audio']['sample_rate'] = $dummy['audio']['sample_rate']; |
---|
86 | |
---|
87 | $ThisFileInfo['audio']['channels'] = ($ThisFileInfo['lpac']['flags']['stereo'] ? 2 : 1); |
---|
88 | |
---|
89 | if ($ThisFileInfo['lpac']['flags']['24_bit']) { |
---|
90 | $ThisFileInfo['audio']['bits_per_sample'] = $ThisFileInfo['riff']['audio'][0]['bits_per_sample']; |
---|
91 | } elseif ($ThisFileInfo['lpac']['flags']['16_bit']) { |
---|
92 | $ThisFileInfo['audio']['bits_per_sample'] = 16; |
---|
93 | } else { |
---|
94 | $ThisFileInfo['audio']['bits_per_sample'] = 8; |
---|
95 | } |
---|
96 | |
---|
97 | if ($ThisFileInfo['lpac']['flags']['fast_compress']) { |
---|
98 | // fast |
---|
99 | $ThisFileInfo['audio']['encoder_options'] = '-1'; |
---|
100 | } else { |
---|
101 | switch ($ThisFileInfo['lpac']['max_prediction_order']) { |
---|
102 | case 20: // simple |
---|
103 | $ThisFileInfo['audio']['encoder_options'] = '-2'; |
---|
104 | break; |
---|
105 | case 30: // medium |
---|
106 | $ThisFileInfo['audio']['encoder_options'] = '-3'; |
---|
107 | break; |
---|
108 | case 40: // high |
---|
109 | $ThisFileInfo['audio']['encoder_options'] = '-4'; |
---|
110 | break; |
---|
111 | case 60: // extrahigh |
---|
112 | $ThisFileInfo['audio']['encoder_options'] = '-5'; |
---|
113 | break; |
---|
114 | } |
---|
115 | } |
---|
116 | |
---|
117 | $ThisFileInfo['playtime_seconds'] = $ThisFileInfo['lpac']['total_samples'] / $ThisFileInfo['audio']['sample_rate']; |
---|
118 | $ThisFileInfo['audio']['bitrate'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / $ThisFileInfo['playtime_seconds']; |
---|
119 | |
---|
120 | return true; |
---|
121 | } |
---|
122 | |
---|
123 | } |
---|
124 | |
---|
125 | |
---|
126 | ?> |
---|