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<?php
/* vim:set tabstop=8 softtabstop=8 shiftwidth=8 noexpandtab: */
// +----------------------------------------------------------------------+
// | 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 <info�getid3*org> |
// | Allan Hansen <ah�artemis*dk> |
// +----------------------------------------------------------------------+
// | module.audio.la.php |
// | Module for analyzing LA udio files |
// | dependencies: module.audio-video.riff.php |
// +----------------------------------------------------------------------+
//
// $Id: module.audio.la.php,v 1.2 2006/11/02 10:48:01 ah Exp $
class getid3_la extends getid3_handler
{
public function Analyze() {
$getid3 = $this->getid3;
$getid3->include_module('audio-video.riff');
fseek($getid3->fp, $getid3->info['avdataoffset'], SEEK_SET);
$raw_data = fread($getid3->fp, getid3::FREAD_BUFFER_SIZE);
$getid3->info['fileformat'] = 'la';
$getid3->info['audio']['dataformat'] = 'la';
$getid3->info['audio']['lossless'] = true;
$getid3->info['la']['version_major'] = (int)$raw_data{2};
$getid3->info['la']['version_minor'] = (int)$raw_data{3};
$getid3->info['la']['version'] = (float)$getid3->info['la']['version_major'] + ($getid3->info['la']['version_minor'] / 10);
$getid3->info['la']['uncompressed_size'] = getid3_lib::LittleEndian2Int(substr($raw_data, 4, 4));
$wave_chunk = substr($raw_data, 8, 4);
if ($wave_chunk !== 'WAVE') {
throw new getid3_exception('Expected "WAVE" ('.getid3_lib::PrintHexBytes('WAVE').') at offset 8, found "'.$wave_chunk.'" ('.getid3_lib::PrintHexBytes($wave_chunk).') instead.');
}
$offset = 12;
$getid3->info['la']['fmt_size'] = 24;
if ($getid3->info['la']['version'] >= 0.3) {
$getid3->info['la']['fmt_size'] = getid3_lib::LittleEndian2Int(substr($raw_data, $offset, 4));
$getid3->info['la']['header_size'] = 49 + $getid3->info['la']['fmt_size'] - 24;
$offset += 4;
} else {
// version 0.2 didn't support additional data blocks
$getid3->info['la']['header_size'] = 41;
}
$fmt_chunk = substr($raw_data, $offset, 4);
if ($fmt_chunk !== 'fmt ') {
throw new getid3_exception('Expected "fmt " ('.getid3_lib::PrintHexBytes('fmt ').') at offset '.$offset.', found "'.$fmt_chunk.'" ('.getid3_lib::PrintHexBytes($fmt_chunk).') instead.');
}
$offset += 4;
$fmt_size = getid3_lib::LittleEndian2Int(substr($raw_data, $offset, 4));
$offset += 4;
$getid3->info['la']['raw']['format'] = getid3_lib::LittleEndian2Int(substr($raw_data, $offset, 2));
$offset += 2;
getid3_lib::ReadSequence('LittleEndian2Int', $getid3->info['la'], $raw_data, $offset,
array (
'channels' => 2,
'sample_rate' => 4,
'bytes_per_second' => 4,
'bytes_per_sample' => 2,
'bits_per_sample' => 2,
'samples' => 4
)
);
$offset += 18;
$getid3->info['la']['raw']['flags'] = getid3_lib::LittleEndian2Int($raw_data{$offset++});
$getid3->info['la']['flags']['seekable'] = (bool)($getid3->info['la']['raw']['flags'] & 0x01);
if ($getid3->info['la']['version'] >= 0.4) {
$getid3->info['la']['flags']['high_compression'] = (bool)($getid3->info['la']['raw']['flags'] & 0x02);
}
$getid3->info['la']['original_crc'] = getid3_lib::LittleEndian2Int(substr($raw_data, $offset, 4));
$offset += 4;
// mike�bevin*de
// Basically, the blocksize/seekevery are 61440/19 in La0.4 and 73728/16
// in earlier versions. A seekpoint is added every blocksize * seekevery
// samples, so 4 * int(totalSamples / (blockSize * seekEvery)) should
// give the number of bytes used for the seekpoints. Of course, if seeking
// is disabled, there are no seekpoints stored.
if ($getid3->info['la']['version'] >= 0.4) {
$getid3->info['la']['blocksize'] = 61440;
$getid3->info['la']['seekevery'] = 19;
} else {
$getid3->info['la']['blocksize'] = 73728;
$getid3->info['la']['seekevery'] = 16;
}
$getid3->info['la']['seekpoint_count'] = 0;
if ($getid3->info['la']['flags']['seekable']) {
$getid3->info['la']['seekpoint_count'] = floor($getid3->info['la']['samples'] / ($getid3->info['la']['blocksize'] * $getid3->info['la']['seekevery']));
for ($i = 0; $i < $getid3->info['la']['seekpoint_count']; $i++) {
$getid3->info['la']['seekpoints'][] = getid3_lib::LittleEndian2Int(substr($raw_data, $offset, 4));
$offset += 4;
}
}
if ($getid3->info['la']['version'] >= 0.3) {
// Following the main header information, the program outputs all of the
// seekpoints. Following these is what I called the 'footer start',
// i.e. the position immediately after the La audio data is finished.
$getid3->info['la']['footerstart'] = getid3_lib::LittleEndian2Int(substr($raw_data, $offset, 4));
$offset += 4;
if ($getid3->info['la']['footerstart'] > $getid3->info['filesize']) {
$getid3->warning('FooterStart value points to offset '.$getid3->info['la']['footerstart'].' which is beyond end-of-file ('.$getid3->info['filesize'].')');
$getid3->info['la']['footerstart'] = $getid3->info['filesize'];
}
} else {
// La v0.2 didn't have FooterStart value
$getid3->info['la']['footerstart'] = $getid3->info['avdataend'];
}
if ($getid3->info['la']['footerstart'] < $getid3->info['avdataend']) {
// Create riff header
$riff_data = 'WAVE';
if ($getid3->info['la']['version'] == 0.2) {
$riff_data .= substr($raw_data, 12, 24);
} else {
$riff_data .= substr($raw_data, 16, 24);
}
if ($getid3->info['la']['footerstart'] < $getid3->info['avdataend']) {
fseek($getid3->fp, $getid3->info['la']['footerstart'], SEEK_SET);
$riff_data .= fread($getid3->fp, $getid3->info['avdataend'] - $getid3->info['la']['footerstart']);
}
$riff_data = 'RIFF'.getid3_lib::LittleEndian2String(strlen($riff_data), 4, false).$riff_data;
// Clone getid3 - messing with offsets - better safe than sorry
$clone = clone $getid3;
// Analyze clone by string
$riff = new getid3_riff($clone);
$riff->AnalyzeString($riff_data);
// Import from clone and destroy
$getid3->info['riff'] = $clone->info['riff'];
$getid3->warnings($clone->warnings());
unset($clone);
}
// $getid3->info['avdataoffset'] should be zero to begin with, but just in case it's not, include the addition anyway
$getid3->info['avdataend'] = $getid3->info['avdataoffset'] + $getid3->info['la']['footerstart'];
$getid3->info['avdataoffset'] = $getid3->info['avdataoffset'] + $offset;
$getid3->info['la']['compression_ratio'] = (float)(($getid3->info['avdataend'] - $getid3->info['avdataoffset']) / $getid3->info['la']['uncompressed_size']);
$getid3->info['playtime_seconds'] = (float)($getid3->info['la']['samples'] / $getid3->info['la']['sample_rate']) / $getid3->info['la']['channels'];
$getid3->info['audio']['bitrate'] = ($getid3->info['avdataend'] - $getid3->info['avdataoffset']) * 8 / $getid3->info['playtime_seconds'];
$getid3->info['audio']['bits_per_sample'] = $getid3->info['la']['bits_per_sample'];
$getid3->info['audio']['channels'] = $getid3->info['la']['channels'];
$getid3->info['audio']['sample_rate'] = (int)$getid3->info['la']['sample_rate'];
$getid3->info['audio']['encoder'] = 'LA v'.$getid3->info['la']['version'];
return true;
}
}
?>
|
