view e2gallerypro/e2upload/Backend/Assets/getid3/module.audio.mpc_old.php @ 28:118cb614cf18 judyates tip

judy bio.
author Robert McIntyre <rlm@mit.edu>
date Tue, 29 Dec 2015 16:26:18 -0800
parents 3f6b44aa6b35
children
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1 <?php
2 // +----------------------------------------------------------------------+
3 // | PHP version 5 |
4 // +----------------------------------------------------------------------+
5 // | Copyright (c) 2002-2006 James Heinrich, Allan Hansen |
6 // +----------------------------------------------------------------------+
7 // | This source file is subject to version 2 of the GPL license, |
8 // | that is bundled with this package in the file license.txt and is |
9 // | available through the world-wide-web at the following url: |
10 // | http://www.gnu.org/copyleft/gpl.html |
11 // +----------------------------------------------------------------------+
12 // | getID3() - http://getid3.sourceforge.net or http://www.getid3.org |
13 // +----------------------------------------------------------------------+
14 // | Authors: James Heinrich <infoØgetid3*org> |
15 // | Allan Hansen <ahØartemis*dk> |
16 // +----------------------------------------------------------------------+
17 // | module.audio.mpc_old.php |
18 // | Module for analyzing Musepack/MPEG+ Audio files - SV4-SV6 |
19 // | dependencies: NONE |
20 // +----------------------------------------------------------------------+
21 //
22 // $Id: module.audio.mpc_old.php,v 1.2 2006/11/02 10:48:01 ah Exp $
26 class getid3_mpc_old extends getid3_handler
27 {
29 public function Analyze() {
31 $getid3 = $this->getid3;
33 // http://www.uni-jena.de/~pfk/mpp/sv8/header.html
35 $getid3->info['mpc']['header'] = array ();
36 $info_mpc_header = &$getid3->info['mpc']['header'];
38 $getid3->info['fileformat'] = 'mpc';
39 $getid3->info['audio']['dataformat'] = 'mpc';
40 $getid3->info['audio']['bitrate_mode'] = 'vbr';
41 $getid3->info['audio']['channels'] = 2; // the format appears to be hardcoded for stereo only
42 $getid3->info['audio']['lossless'] = false;
44 fseek($getid3->fp, $getid3->info['avdataoffset'], SEEK_SET);
46 $info_mpc_header['size'] = 8;
47 $getid3->info['avdataoffset'] += $info_mpc_header['size'];
49 $mpc_header_data = fread($getid3->fp, $info_mpc_header['size']);
52 // Most of this code adapted from Jurgen Faul's MPEGplus source code - thanks Jurgen! :)
53 $header_dword[0] = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 0, 4));
54 $header_dword[1] = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 4, 4));
57 // DDDD DDDD CCCC CCCC BBBB BBBB AAAA AAAA
58 // aaaa aaaa abcd dddd dddd deee eeff ffff
59 //
60 // a = bitrate = anything
61 // b = IS = anything
62 // c = MS = anything
63 // d = streamversion = 0000000004 or 0000000005 or 0000000006
64 // e = maxband = anything
65 // f = blocksize = 000001 for SV5+, anything(?) for SV4
67 $info_mpc_header['target_bitrate'] = (($header_dword[0] & 0xFF800000) >> 23);
68 $info_mpc_header['intensity_stereo'] = (bool)(($header_dword[0] & 0x00400000) >> 22);
69 $info_mpc_header['mid-side_stereo'] = (bool)(($header_dword[0] & 0x00200000) >> 21);
70 $info_mpc_header['stream_major_version'] = ($header_dword[0] & 0x001FF800) >> 11;
71 $info_mpc_header['stream_minor_version'] = 0;
72 $info_mpc_header['max_band'] = ($header_dword[0] & 0x000007C0) >> 6; // related to lowpass frequency, not sure how it translates exactly
73 $info_mpc_header['block_size'] = ($header_dword[0] & 0x0000003F);
75 switch ($info_mpc_header['stream_major_version']) {
76 case 4:
77 $info_mpc_header['frame_count'] = ($header_dword[1] >> 16);
78 break;
79 case 5:
80 case 6:
81 $info_mpc_header['frame_count'] = $header_dword[1];
82 break;
84 default:
85 throw new getid3_exception('Expecting 4, 5 or 6 in version field, found '.$info_mpc_header['stream_major_version'].' instead');
86 }
88 if (($info_mpc_header['stream_major_version'] > 4) && ($info_mpc_header['block_size'] != 1)) {
89 $getid3->warning('Block size expected to be 1, actual value found: '.$info_mpc_header['block_size']);
90 }
92 $info_mpc_header['sample_rate'] = $getid3->info['audio']['sample_rate'] = 44100; // AB: used by all files up to SV7
93 $info_mpc_header['samples'] = $info_mpc_header['frame_count'] * 1152 * $getid3->info['audio']['channels'];
95 $getid3->info['audio']['bitrate_mode'] = $info_mpc_header['target_bitrate'] == 0 ? 'vbr' : 'cbr';
97 $getid3->info['mpc']['bitrate'] = ($getid3->info['avdataend'] - $getid3->info['avdataoffset']) * 8 * 44100 / $info_mpc_header['frame_count'] / 1152;
98 $getid3->info['audio']['bitrate'] = $getid3->info['mpc']['bitrate'];
99 $getid3->info['audio']['encoder'] = 'SV'.$info_mpc_header['stream_major_version'];
101 return true;
102 }
104 }
107 ?>