Updates the srcpad caps and send the caps downstream. This function
can be used by subclasses when they have already negotiated their caps
but found a change in them (or computed new informations). This way,
they can notify downstream about that change without loosing any
buffer.
Updates the srcpad caps and send the caps downstream. This function can be used by subclasses when they have already negotiated their caps but found a change in them (or computed new informations). This way, they can notify downstream about that change without loosing any buffer.