If the GstBaseSinkClas.render|GstBaseSinkClas.renders method performs its own synchronisation
against the clock it must unblock when going from PLAYING to the PAUSED state
and call this method before continuing to render the remaining data.
This function will block until a state change to PLAYING happens (in which
case this function returns GST_FLOW_OK) or the processing must be stopped due
to a state change to READY or a FLUSH event (in which case this function
returns GST_FLOW_FLUSHING).
This function should only be called with the PREROLL_LOCK held, like in the
render function.
If the GstBaseSinkClas.render|GstBaseSinkClas.renders method performs its own synchronisation against the clock it must unblock when going from PLAYING to the PAUSED state and call this method before continuing to render the remaining data.
If the GstBaseSinkClas.render|GstBaseSinkClas.renders method can block on something else than the clock, it must also be ready to unblock immediately on the GstBaseSinkClas.unlock|GstBaseSinkClas.unlocks method and cause the GstBaseSinkClas.render|GstBaseSinkClas.renders method to immediately call this function. In this case, the subclass must be prepared to continue rendering where it left off if this function returns GST_FLOW_OK.
This function will block until a state change to PLAYING happens (in which case this function returns GST_FLOW_OK) or the processing must be stopped due to a state change to READY or a FLUSH event (in which case this function returns GST_FLOW_FLUSHING).
This function should only be called with the PREROLL_LOCK held, like in the render function.