element has no clock or its base time has not been set.
Element.getCurrentRunningTime
gst.types.ClockTime getCurrentRunningTime()Returns the running time of the element. The running time is the element's clock time minus its base time. Will return GST_CLOCK_TIME_NONE if the element has no clock, or if its base time has not been set.
Returns
the running time of the element, or GST_CLOCK_TIME_NONE if the