Syntax Syntax
Parameters Parameters
- $offset
-
(Required)
- $nextframetestoffset
-
(Required)
- $ScanAsCBR
-
(Required)
Return Return
(bool)
Source Source
File: wp-includes/ID3/module.audio.mp3.php
//}
return true;
}
/**
* @param int $offset
* @param int $nextframetestoffset
* @param bool $ScanAsCBR
*
* @return bool
*/
public function RecursiveFrameScanning(&$offset, &$nextframetestoffset, $ScanAsCBR) {
$info = &$this->getid3->info;
$firstframetestarray = array('error' => array(), 'warning'=> array(), 'avdataend' => $info['avdataend'], 'avdataoffset' => $info['avdataoffset']);
$this->decodeMPEGaudioHeader($offset, $firstframetestarray, false);
for ($i = 0; $i < GETID3_MP3_VALID_CHECK_FRAMES; $i++) {
// check next GETID3_MP3_VALID_CHECK_FRAMES frames for validity, to make sure we haven't run across a false synch
if (($nextframetestoffset + 4) >= $info['avdataend']) {
// end of file
return true;
}
$nextframetestarray = array('error' => array(), 'warning' => array(), 'avdataend' => $info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
if ($this->decodeMPEGaudioHeader($nextframetestoffset, $nextframetestarray, false)) {
if ($ScanAsCBR) {
// force CBR mode, used for trying to pick out invalid audio streams with valid(?) VBR headers, or VBR streams with no VBR header
if (!isset($nextframetestarray['mpeg']['audio']['bitrate']) || !isset($firstframetestarray['mpeg']['audio']['bitrate']) || ($nextframetestarray['mpeg']['audio']['bitrate'] != $firstframetestarray['mpeg']['audio']['bitrate'])) {
return false;
}
}
// next frame is OK, get ready to check the one after that
if (isset($nextframetestarray['mpeg']['audio']['framelength']) && ($nextframetestarray['mpeg']['audio']['framelength'] > 0)) {
$nextframetestoffset += $nextframetestarray['mpeg']['audio']['framelength'];
} else {
$this->error('Frame at offset ('.$offset.') is has an invalid frame length.');
return false;
}
} elseif (!empty($firstframetestarray['mpeg']['audio']['framelength']) && (($nextframetestoffset + $firstframetestarray['mpeg']['audio']['framelength']) > $info['avdataend'])) {
// it's not the end of the file, but there's not enough data left for another frame, so assume it's garbage/padding and return OK