Sets the provided pad's last flow return to provided value and computes
the combined flow return for the pads in it.
The GstFlowReturn parameter should be the last flow return update for a pad
in this gst.FlowCombiner.FlowCombiner It will use this value to be able to shortcut some
combinations and avoid looking over all pads again. e.g. The last combined
return is the same as the latest obtained GstFlowReturn
Sets the provided pad's last flow return to provided value and computes the combined flow return for the pads in it.
The GstFlowReturn parameter should be the last flow return update for a pad in this gst.FlowCombiner.FlowCombiner It will use this value to be able to shortcut some combinations and avoid looking over all pads again. e.g. The last combined return is the same as the latest obtained GstFlowReturn