function covtime($youtube_time) {
    preg_match_all('/(\d+)/',$youtube_time,$parts);
    if (count($parts[0]) == 1) {
        array_unshift($parts[0], "0", "0");
    } elseif (count($parts[0]) == 2) {
        array_unshift($parts[0], "0");
    }
    $sec_init = $parts[0][2];
    $seconds = $sec_init%60;
    $seconds_overflow = floor($sec_init/60);
    $min_init = $parts[0][1] + $seconds_overflow;
    $minutes = ($min_init)%60;
    $minutes_overflow = floor(($min_init)/60);
    $hours = $parts[0][0] + $minutes_overflow;
    if($hours != 0)
        return $hours.':'.$minutes.':'.$seconds;
    else
        return $minutes.':'.$seconds;
}