public function scale($_baseTime, $_factor = 1)
{
if ($_factor == 1) {
return false;
}
$new_start = $_baseTime + ($this->getStartMS() - $_baseTime) * $_factor;
$new_stop = $_baseTime + ($this->getStopMS() - $_baseTime) * $_factor;
$this->setStartMS($new_start);
$this->setStopMS($new_stop);
return true;
}