<?php
$tempo_total= "4:44";
sscanf($tempo_total, "%d:%d:%d", $horas, $minutos, $segundos);
$tempo_segundos = isset($segundos) ?
$horas * 3600 + $minutos * 60 + $segundos : $horas * 60 + $minutos;
echo $tempo_segundos;
PD9waHAKCiR0ZW1wb190b3RhbD0gIjQ6NDQiOwoKc3NjYW5mKCR0ZW1wb190b3RhbCwgIiVkOiVkOiVkIiwgJGhvcmFzLCAkbWludXRvcywgJHNlZ3VuZG9zKTsKCiR0ZW1wb19zZWd1bmRvcyA9IGlzc2V0KCRzZWd1bmRvcykgPyAkaG9yYXMgKiAzNjAwICsgJG1pbnV0b3MgKiA2MCArICRzZWd1bmRvcyA6ICRob3JhcyAqIDYwICsgJG1pbnV0b3M7CgplY2hvICR0ZW1wb19zZWd1bmRvczsK