+
+framecnt_t
+Route::update_port_latencies (PortSet& from, PortSet& to, bool playback, framecnt_t our_latency) const
+{
+ /* we assume that all our input ports feed all our output ports. its not
+ universally true, but the alternative is way too corner-case to worry about.
+ */
+
+ jack_latency_range_t all_connections;
+
+ if (from.empty()) {
+ all_connections.min = 0;
+ all_connections.max = 0;
+ } else {
+ all_connections.min = ~((jack_nframes_t) 0);
+ all_connections.max = 0;
+
+ /* iterate over all "from" ports and determine the latency range for all of their
+ connections to the "outside" (outside of this Route).
+ */
+
+ for (PortSet::iterator p = from.begin(); p != from.end(); ++p) {
+
+ jack_latency_range_t range;
+
+ p->get_connected_latency_range (range, playback);
+
+ all_connections.min = min (all_connections.min, range.min);
+ all_connections.max = max (all_connections.max, range.max);
+ }
+ }
+
+ /* set the "from" port latencies to the max/min range of all their connections */
+
+ for (PortSet::iterator p = from.begin(); p != from.end(); ++p) {
+ p->set_private_latency_range (all_connections, playback);
+ }
+
+ /* set the ports "in the direction of the flow" to the same value as above plus our own signal latency */
+
+ all_connections.min += our_latency;
+ all_connections.max += our_latency;
+
+ for (PortSet::iterator p = to.begin(); p != to.end(); ++p) {
+ p->set_private_latency_range (all_connections, playback);
+ }
+
+ return all_connections.max;
+}
+
+framecnt_t
+Route::set_private_port_latencies (bool playback) const
+{
+ framecnt_t own_latency = 0;
+
+ /* Processor list not protected by lock: MUST BE CALLED FROM PROCESS THREAD
+ OR LATENCY CALLBACK.
+
+ This is called (early) from the latency callback. It computes the REAL
+ latency associated with each port and stores the result as the "private"
+ latency of the port. A later call to Route::set_public_port_latencies()
+ sets all ports to the same value to reflect the fact that we do latency
+ compensation and so all signals are delayed by the same amount as they
+ flow through ardour.
+ */
+
+ for (ProcessorList::const_iterator i = _processors.begin(); i != _processors.end(); ++i) {
+ if ((*i)->active ()) {
+ own_latency += (*i)->signal_latency ();
+ }
+ }
+
+ if (playback) {
+ /* playback: propagate latency from "outside the route" to outputs to inputs */
+ return update_port_latencies (_output->ports (), _input->ports (), true, own_latency);
+ } else {
+ /* capture: propagate latency from "outside the route" to inputs to outputs */
+ return update_port_latencies (_input->ports (), _output->ports (), false, own_latency);
+ }
+}
+