diff options
Diffstat (limited to 'modules/getid3/module.audio.mpc_old.php')
| -rw-r--r-- | modules/getid3/module.audio.mpc_old.php | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/modules/getid3/module.audio.mpc_old.php b/modules/getid3/module.audio.mpc_old.php new file mode 100644 index 00000000..15971789 --- /dev/null +++ b/modules/getid3/module.audio.mpc_old.php @@ -0,0 +1,107 @@ +<?php +// +----------------------------------------------------------------------+
+// | PHP version 5 |
+// +----------------------------------------------------------------------+
+// | Copyright (c) 2002-2006 James Heinrich, Allan Hansen |
+// +----------------------------------------------------------------------+
+// | This source file is subject to version 2 of the GPL license, |
+// | that is bundled with this package in the file license.txt and is |
+// | available through the world-wide-web at the following url: |
+// | http://www.gnu.org/copyleft/gpl.html | +// +----------------------------------------------------------------------+ +// | getID3() - http://getid3.sourceforge.net or http://www.getid3.org | +// +----------------------------------------------------------------------+
+// | Authors: James Heinrich <infoØgetid3*org> |
+// | Allan Hansen <ahØartemis*dk> |
+// +----------------------------------------------------------------------+ +// | module.audio.mpc_old.php | +// | Module for analyzing Musepack/MPEG+ Audio files - SV4-SV6 | +// | dependencies: NONE | +// +----------------------------------------------------------------------+
+//
+// $Id: module.audio.mpc_old.php,v 1.2 2006/11/02 10:48:01 ah Exp $ + + + +class getid3_mpc_old extends getid3_handler +{ + + public function Analyze() { + + $getid3 = $this->getid3; + + // http://www.uni-jena.de/~pfk/mpp/sv8/header.html + + $getid3->info['mpc']['header'] = array (); + $info_mpc_header = &$getid3->info['mpc']['header']; + + $getid3->info['fileformat'] = 'mpc'; + $getid3->info['audio']['dataformat'] = 'mpc'; + $getid3->info['audio']['bitrate_mode'] = 'vbr'; + $getid3->info['audio']['channels'] = 2; // the format appears to be hardcoded for stereo only + $getid3->info['audio']['lossless'] = false; + + fseek($getid3->fp, $getid3->info['avdataoffset'], SEEK_SET); + + $info_mpc_header['size'] = 8; + $getid3->info['avdataoffset'] += $info_mpc_header['size']; + + $mpc_header_data = fread($getid3->fp, $info_mpc_header['size']); + + + // Most of this code adapted from Jurgen Faul's MPEGplus source code - thanks Jurgen! :) + $header_dword[0] = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 0, 4)); + $header_dword[1] = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 4, 4)); + + + // DDDD DDDD CCCC CCCC BBBB BBBB AAAA AAAA + // aaaa aaaa abcd dddd dddd deee eeff ffff + // + // a = bitrate = anything + // b = IS = anything + // c = MS = anything + // d = streamversion = 0000000004 or 0000000005 or 0000000006 + // e = maxband = anything + // f = blocksize = 000001 for SV5+, anything(?) for SV4 + + $info_mpc_header['target_bitrate'] = (($header_dword[0] & 0xFF800000) >> 23); + $info_mpc_header['intensity_stereo'] = (bool)(($header_dword[0] & 0x00400000) >> 22); + $info_mpc_header['mid-side_stereo'] = (bool)(($header_dword[0] & 0x00200000) >> 21); + $info_mpc_header['stream_major_version'] = ($header_dword[0] & 0x001FF800) >> 11; + $info_mpc_header['stream_minor_version'] = 0; + $info_mpc_header['max_band'] = ($header_dword[0] & 0x000007C0) >> 6; // related to lowpass frequency, not sure how it translates exactly + $info_mpc_header['block_size'] = ($header_dword[0] & 0x0000003F); + + switch ($info_mpc_header['stream_major_version']) { + case 4: + $info_mpc_header['frame_count'] = ($header_dword[1] >> 16); + break; + case 5: + case 6: + $info_mpc_header['frame_count'] = $header_dword[1]; + break; + + default: + throw new getid3_exception('Expecting 4, 5 or 6 in version field, found '.$info_mpc_header['stream_major_version'].' instead'); + } + + if (($info_mpc_header['stream_major_version'] > 4) && ($info_mpc_header['block_size'] != 1)) { + $getid3->warning('Block size expected to be 1, actual value found: '.$info_mpc_header['block_size']); + } + + $info_mpc_header['sample_rate'] = $getid3->info['audio']['sample_rate'] = 44100; // AB: used by all files up to SV7 + $info_mpc_header['samples'] = $info_mpc_header['frame_count'] * 1152 * $getid3->info['audio']['channels']; + + $getid3->info['audio']['bitrate_mode'] = $info_mpc_header['target_bitrate'] == 0 ? 'vbr' : 'cbr'; + + $getid3->info['mpc']['bitrate'] = ($getid3->info['avdataend'] - $getid3->info['avdataoffset']) * 8 * 44100 / $info_mpc_header['frame_count'] / 1152; + $getid3->info['audio']['bitrate'] = $getid3->info['mpc']['bitrate']; + $getid3->info['audio']['encoder'] = 'SV'.$info_mpc_header['stream_major_version']; + + return true; + } + +} + + +?>
\ No newline at end of file |