90% done with external sync design changes (GUI now has toggle switch for ext/int sync; source chosen separately, currently in ardour prefs dialog ; fix libmidi++ and compilation scripts to correctly build JACK+ALSA support; minor contiuing tweaks on transport stuff

git-svn-id: svn://localhost/ardour2/branches/3.0@6048 d708f5d6-7413-0410-9779-e7cbd77b26cf

19 files changed, 140 insertions, 113 deletions

diff --git a/libs/ardour/ardour/rc_configuration_vars.h b/libs/ardour/ardour/rc_configuration_vars.h
index 5b0be5cccf..f8e61bff79 100644
--- a/libs/ardour/ardour/rc_configuration_vars.h
+++ b/libs/ardour/ardour/rc_configuration_vars.h
@@ -108,7 +108,6 @@ CONFIG_VARIABLE (nframes_t, postroll, "postroll", 0)
 CONFIG_VARIABLE (float, rf_speed, "rf-speed", 2.0f)
 CONFIG_VARIABLE (float, shuttle_speed_factor, "shuttle-speed-factor", 1.0f)
 CONFIG_VARIABLE (float, shuttle_speed_threshold, "shuttle-speed-threshold", 5.0f)
-CONFIG_VARIABLE (SlaveSource, slave_source, "slave-source", None)
 CONFIG_VARIABLE (ShuttleBehaviour, shuttle_behaviour, "shuttle-behaviour", Sprung)
 CONFIG_VARIABLE (ShuttleUnits, shuttle_units, "shuttle-units", Percentage)
 CONFIG_VARIABLE (bool, primary_clock_delta_edit_cursor, "primary-clock-delta-edit-cursor", false)
diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 6ac36f98b6..d36bc51079 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -145,7 +145,7 @@ class Session : public PBD::StatefulDestructible, public boost::noncopyable
 			RangeStop,
 			RangeLocate,
 			Overwrite,
-			SetSlaveSource,
+			SetSyncSource,
 			Audition,
 			InputConfigurationChange,
 			SetPlayAudioRange,
@@ -173,7 +173,7 @@ class Session : public PBD::StatefulDestructible, public boost::noncopyable
 		void*        ptr;
 		bool         yes_or_no;
 		nframes64_t  target2_frame;
-		SlaveSource  slave;
+		SyncSource   sync_source;
 		Route*       route;
 	    };
 
@@ -576,8 +576,9 @@ class Session : public PBD::StatefulDestructible, public boost::noncopyable
 	static sigc::signal<void> EndTimeChanged;
 	static sigc::signal<void> TimecodeOffsetChanged;
 
-	void   request_slave_source (SlaveSource);
-	bool   synced_to_jack() const { return Config->get_slave_source() == JACK; }
+        std::vector<SyncSource> get_available_sync_options() const;
+	void   request_sync_source (SyncSource);
+        bool   synced_to_jack() const { return config.get_external_sync() && config.get_sync_source() == JACK; }
 
 	double transport_speed() const { return _transport_speed; }
 	bool   transport_stopped() const { return _transport_speed == 0.0f; }
@@ -1074,9 +1075,10 @@ class Session : public PBD::StatefulDestructible, public boost::noncopyable
 	                       nframes_t this_delta, bool starting);
 	void follow_slave_silently(nframes_t nframes, float slave_speed);
 
-	void set_slave_source (SlaveSource);
+        void use_sync_source (SyncSource);
+        void drop_sync_source ();
 
-	SlaveSource post_export_slave;
+        bool post_export_sync;
 	nframes_t post_export_position;
 
 	bool _exporting;
diff --git a/libs/ardour/ardour/session_configuration_vars.h b/libs/ardour/ardour/session_configuration_vars.h
index fd85993a29..2776787271 100644
--- a/libs/ardour/ardour/session_configuration_vars.h
+++ b/libs/ardour/ardour/session_configuration_vars.h
@@ -47,3 +47,5 @@ CONFIG_VARIABLE (bool, use_video_sync, "use-video-sync", false)
 CONFIG_VARIABLE (float, video_pullup, "video-pullup", 0.0f)
 CONFIG_VARIABLE (bool, show_summary, "show-summary", true)
 CONFIG_VARIABLE (bool, show_group_tabs, "show-group-tabs", true)
+CONFIG_VARIABLE (bool, external_sync, "external-sync", false)
+CONFIG_VARIABLE (SyncSource, sync_source, "sync-source", JACK)
diff --git a/libs/ardour/ardour/types.h b/libs/ardour/ardour/types.h
index dd2c8861be..7e09417409 100644
--- a/libs/ardour/ardour/types.h
+++ b/libs/ardour/ardour/types.h
@@ -360,10 +360,9 @@ namespace ARDOUR {
 		ExportContext
 	};
 
-	enum SlaveSource {
-		None = 0,
-		MTC,
+	enum SyncSource {
 		JACK,
+		MTC,
 		MIDIClock
 	};
 
@@ -444,7 +443,7 @@ std::istream& operator>>(std::istream& o, ARDOUR::RemoteModel& sf);
 std::istream& operator>>(std::istream& o, ARDOUR::ListenPosition& sf);
 std::istream& operator>>(std::istream& o, ARDOUR::LayerModel& sf);
 std::istream& operator>>(std::istream& o, ARDOUR::CrossfadeModel& sf);
-std::istream& operator>>(std::istream& o, ARDOUR::SlaveSource& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::SyncSource& sf);
 std::istream& operator>>(std::istream& o, ARDOUR::ShuttleBehaviour& sf);
 std::istream& operator>>(std::istream& o, ARDOUR::ShuttleUnits& sf);
 std::istream& operator>>(std::istream& o, ARDOUR::TimecodeFormat& sf);
@@ -461,7 +460,7 @@ std::ostream& operator<<(std::ostream& o, const ARDOUR::RemoteModel& sf);
 std::ostream& operator<<(std::ostream& o, const ARDOUR::ListenPosition& sf);
 std::ostream& operator<<(std::ostream& o, const ARDOUR::LayerModel& sf);
 std::ostream& operator<<(std::ostream& o, const ARDOUR::CrossfadeModel& sf);
-std::ostream& operator<<(std::ostream& o, const ARDOUR::SlaveSource& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::SyncSource& sf);
 std::ostream& operator<<(std::ostream& o, const ARDOUR::ShuttleBehaviour& sf);
 std::ostream& operator<<(std::ostream& o, const ARDOUR::ShuttleUnits& sf);
 std::ostream& operator<<(std::ostream& o, const ARDOUR::TimecodeFormat& sf);
diff --git a/libs/ardour/ardour/utils.h b/libs/ardour/ardour/utils.h
index c43b7ed37e..6c6f754cf9 100644
--- a/libs/ardour/ardour/utils.h
+++ b/libs/ardour/ardour/utils.h
@@ -62,8 +62,8 @@ bool path_is_paired (Glib::ustring path, Glib::ustring& pair_base);
 
 void compute_equal_power_fades (ARDOUR::nframes_t nframes, float* in, float* out);
 
-const char* slave_source_to_string (ARDOUR::SlaveSource src);
-ARDOUR::SlaveSource string_to_slave_source (std::string str);
+const char* sync_source_to_string (ARDOUR::SyncSource src);
+ARDOUR::SyncSource string_to_sync_source (std::string str);
 
 const char* edit_mode_to_string (ARDOUR::EditMode);
 ARDOUR::EditMode string_to_edit_mode (std::string);
diff --git a/libs/ardour/enums.cc b/libs/ardour/enums.cc
index 885ebeb27a..ed7ba88d8e 100644
--- a/libs/ardour/enums.cc
+++ b/libs/ardour/enums.cc
@@ -70,7 +70,7 @@ setup_enum_writer ()
 	CDMarkerFormat _CDMarkerFormat;
 	HeaderFormat _HeaderFormat;
 	PluginType _PluginType;
-	SlaveSource _SlaveSource;
+	SyncSource _SyncSource;
 	ShuttleBehaviour _ShuttleBehaviour;
 	ShuttleUnits _ShuttleUnits;
 	Session::RecordState _Session_RecordState;
@@ -266,11 +266,10 @@ setup_enum_writer ()
 	REGISTER_ENUM (VST);
 	REGISTER (_PluginType);
 
-	REGISTER_ENUM (None);
 	REGISTER_ENUM (MTC);
 	REGISTER_ENUM (JACK);
 	REGISTER_ENUM (MIDIClock);
-	REGISTER (_SlaveSource);
+	REGISTER (_SyncSource);
 
 	REGISTER_ENUM (Sprung);
 	REGISTER_ENUM (Wheel);
@@ -296,7 +295,7 @@ setup_enum_writer ()
 	REGISTER_CLASS_ENUM (Session::Event, RangeStop);
 	REGISTER_CLASS_ENUM (Session::Event, RangeLocate);
 	REGISTER_CLASS_ENUM (Session::Event, Overwrite);
-	REGISTER_CLASS_ENUM (Session::Event, SetSlaveSource);
+	REGISTER_CLASS_ENUM (Session::Event, SetSyncSource);
 	REGISTER_CLASS_ENUM (Session::Event, Audition);
 	REGISTER_CLASS_ENUM (Session::Event, InputConfigurationChange);
 	REGISTER_CLASS_ENUM (Session::Event, SetPlayAudioRange);
@@ -669,15 +668,15 @@ std::ostream& operator<<(std::ostream& o, const CrossfadeModel& var)
 	std::string s = enum_2_string (var);
 	return o << s;
 }
-std::istream& operator>>(std::istream& o, SlaveSource& var) 
+std::istream& operator>>(std::istream& o, SyncSource& var) 
 { 
 	std::string s;
 	o >> s;
-	var = (SlaveSource) string_2_enum (s, var);
+	var = (SyncSource) string_2_enum (s, var);
 	return o;
 }
 
-std::ostream& operator<<(std::ostream& o, const SlaveSource& var) 
+std::ostream& operator<<(std::ostream& o, const SyncSource& var) 
 { 
 	std::string s = enum_2_string (var);
 	return o << s;
diff --git a/libs/ardour/globals.cc b/libs/ardour/globals.cc
index 4d75c30a0d..8efb72cc8c 100644
--- a/libs/ardour/globals.cc
+++ b/libs/ardour/globals.cc
@@ -126,7 +126,6 @@ int
 ARDOUR::setup_midi ()
 {
 	if (Config->midi_ports.size() == 0) {
-		//warning << _("no MIDI ports specified: no MMC or MTC control possible") << endmsg;
 		return 0;
 	}
 
@@ -139,27 +138,17 @@ ARDOUR::setup_midi ()
 	MIDI::Port* first;
 	const MIDI::Manager::PortMap& ports = MIDI::Manager::instance()->get_midi_ports();
 
+
 	if (ports.size() > 1) {
 
 		first = ports.begin()->second;
 
 		/* More than one port, so try using specific names for each port */
 
-		if (Config->get_mmc_port_name() != N_("control")) {
-			default_mmc_port =  MIDI::Manager::instance()->port (Config->get_mmc_port_name());
-		}
-
-		if (Config->get_mtc_port_name() != N_("control")) {
-			default_mtc_port =  MIDI::Manager::instance()->port (Config->get_mtc_port_name());
-		}
-
-		if (Config->get_midi_port_name() != N_("control")) {
-			default_midi_port =  MIDI::Manager::instance()->port (Config->get_midi_port_name());
-		}
-
-		if (Config->get_midi_clock_port_name() != N_("control")) {
-			default_midi_port =  MIDI::Manager::instance()->port (Config->get_midi_clock_port_name());
-		}
+		default_mmc_port =  MIDI::Manager::instance()->port (Config->get_mmc_port_name());
+		default_mtc_port =  MIDI::Manager::instance()->port (Config->get_mtc_port_name());
+		default_midi_port =  MIDI::Manager::instance()->port (Config->get_midi_port_name());
+		default_midi_clock_port =  MIDI::Manager::instance()->port (Config->get_midi_clock_port_name());
 
 		/* If that didn't work, just use the first listed port */
 
@@ -194,7 +183,6 @@ ARDOUR::setup_midi ()
 	if (default_mmc_port == 0) {
 		warning << string_compose (_("No MMC control (MIDI port \"%1\" not available)"), Config->get_mmc_port_name())
 			<< endmsg;
-		return 0;
 	}
 
 
@@ -339,8 +327,11 @@ ARDOUR::init (bool use_vst, bool try_optimization)
 		return -1;
 	}
 
+	
 	Config->set_use_vst (use_vst);
 
+	cerr << "After config loaded, MTC port name = " << Config->get_mtc_port_name() << endl;
+
 	Profile = new RuntimeProfile;
 
 
diff --git a/libs/ardour/rc_configuration.cc b/libs/ardour/rc_configuration.cc
index f04c148ab7..b34a6fd1ee 100644
--- a/libs/ardour/rc_configuration.cc
+++ b/libs/ardour/rc_configuration.cc
@@ -203,6 +203,8 @@ RCConfiguration::get_state ()
 	MIDI::Manager::PortMap::const_iterator i;
 	const MIDI::Manager::PortMap& ports = MIDI::Manager::instance()->get_midi_ports();
 
+	cerr << "Saving " << ports.size() << " MIDI ports\n";
+
 	for (i = ports.begin(); i != ports.end(); ++i) {
 		root->add_child_nocopy(i->second->get_state());
 	}
@@ -260,8 +262,11 @@ RCConfiguration::set_state (const XMLNode& root, int /*version*/)
 
 				MIDI::Port::Descriptor desc (*node);
 				map<string,XMLNode>::iterator x;
+				
 				if ((x = midi_ports.find (desc.tag)) != midi_ports.end()) {
-					midi_ports.erase (x);
+					warning << string_compose (_("Duplicate MIDI port definition found (tag=\"%1\") - ignored"),
+								   desc.tag) << endmsg;
+					continue;
 				}
 				midi_ports.insert (pair<string,XMLNode>(desc.tag,*node));
 			}
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 509fb0a999..9d7d32d17e 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -4444,3 +4444,21 @@ Session::route_group_changed ()
 {
 	RouteGroupChanged (); /* EMIT SIGNAL */
 }
+
+vector<SyncSource>
+Session::get_available_sync_options () const
+{
+	vector<SyncSource> ret;
+	
+	ret.push_back (JACK);
+
+	if (mtc_port()) {
+		ret.push_back (MTC);
+	} 
+
+	if (midi_clock_port()) {
+		ret.push_back (MIDIClock);
+	} 
+
+	return ret;
+}
diff --git a/libs/ardour/session_events.cc b/libs/ardour/session_events.cc
index fb993faa68..7304991948 100644
--- a/libs/ardour/session_events.cc
+++ b/libs/ardour/session_events.cc
@@ -393,8 +393,8 @@ Session::process_event (Event* ev)
 		set_diskstream_speed (static_cast<Diskstream*> (ev->ptr), ev->speed);
 		break;
 
-	case Event::SetSlaveSource:
-		set_slave_source (ev->slave);
+	case Event::SetSyncSource:
+		use_sync_source (ev->sync_source);
 		break;
 
 	case Event::Audition:
diff --git a/libs/ardour/session_export.cc b/libs/ardour/session_export.cc
index 0bf87591cd..da18ceb3cb 100644
--- a/libs/ardour/session_export.cc
+++ b/libs/ardour/session_export.cc
@@ -85,10 +85,10 @@ Session::pre_export ()
 
 	/* no slaving */
 
-	post_export_slave = Config->get_slave_source ();
+	post_export_sync = config.get_external_sync ();
 	post_export_position = _transport_frame;
 
-	Config->set_slave_source (None);
+	config.set_external_sync (false);
 
 	_exporting = true;
 	export_status->running = true;
@@ -244,8 +244,8 @@ Session::finalize_audio_export ()
 
 	/* restart slaving */
 
-	if (post_export_slave != None) {
-		Config->set_slave_source (post_export_slave);
+	if (post_export_sync) {
+		config.set_external_sync (true);
 	} else {
 		locate (post_export_position, false, false, false);
 	}
diff --git a/libs/ardour/session_midi.cc b/libs/ardour/session_midi.cc
index f7ee8ef3c9..34d9b470f5 100644
--- a/libs/ardour/session_midi.cc
+++ b/libs/ardour/session_midi.cc
@@ -141,6 +141,8 @@ Session::set_mtc_port (string port_tag)
 		ms->rebind (*port);
 	}
 
+	cerr << "!!SPT to " << port_tag << endl;
+
 	Config->set_mtc_port_name (port_tag);
 
   out:
@@ -494,7 +496,7 @@ Session::setup_midi_control ()
 void
 Session::spp_start (Parser &, nframes_t /*timestamp*/)
 {
-	if (Config->get_mmc_control() && (Config->get_slave_source() != MTC)) {
+	if (Config->get_mmc_control() && (config.get_external_sync() && config.get_sync_source() != MTC)) {
 		request_transport_speed (1.0);
 	}
 }
@@ -516,7 +518,7 @@ Session::spp_stop (Parser&, nframes_t /*timestamp*/)
 void
 Session::midi_clock_start (Parser& ignored, nframes_t timestamp)
 {
-	if (Config->get_slave_source() == MIDIClock) {
+        if (config.get_external_sync() && (config.get_sync_source() == MIDIClock)) {
 		request_transport_speed (1.0);
 	}
 }
@@ -530,7 +532,7 @@ Session::midi_clock_continue (Parser& parser, nframes_t timestamp)
 void
 Session::midi_clock_stop (Parser& ignored, nframes_t timestamp)
 {
-	if (Config->get_slave_source() == MIDIClock) {
+	if (config.get_external_sync() && (config.get_slave_source() == MIDIClock)) {
 		request_stop ();
 	}
 }
@@ -539,7 +541,7 @@ Session::midi_clock_stop (Parser& ignored, nframes_t timestamp)
 void
 Session::mmc_deferred_play (MIDI::MachineControl &/*mmc*/)
 {
-	if (Config->get_mmc_control() && (Config->get_slave_source() != MTC)) {
+	if (Config->get_mmc_control() && (config.get_external_sync() && (config.get_sync_source() != MTC))) {
 		request_transport_speed (1.0);
 	}
 }
diff --git a/libs/ardour/session_process.cc b/libs/ardour/session_process.cc
index 4bbe852687..a79a2e4cd8 100644
--- a/libs/ardour/session_process.cc
+++ b/libs/ardour/session_process.cc
@@ -469,7 +469,7 @@ Session::transport_locked () const
 {
 	Slave* sl = _slave;
 
-	if (!locate_pending() && ((Config->get_slave_source() == None) || (sl && sl->ok() && sl->locked()))) {
+	if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
 		return true;
 	}
 
@@ -487,7 +487,7 @@ Session::follow_slave (nframes_t nframes)
 
 	if (!_slave->ok()) {
 		stop_transport ();
-		Config->set_slave_source (None);
+		config.set_external_sync (false);
 		goto noroll;
 	}
 
diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index 1a4758186e..2e564b7eee 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -215,6 +215,7 @@ Session::first_stage_init (string fullpath, string snapshot_name)
 	destructive_index = 0;
 	first_file_data_format_reset = true;
 	first_file_header_format_reset = true;
+	post_export_sync = false;
 	//midi_thread = (pthread_t) 0;
 
 	AudioDiskstream::allocate_working_buffers();
@@ -869,15 +870,7 @@ int
 Session::load_options (const XMLNode& node)
 {
 	LocaleGuard lg (X_("POSIX"));
-
 	config.set_variables (node);
-
-	/* now reset MIDI ports because the session can have its own
-	   MIDI configuration.
-	*/
-
-	setup_midi ();
-
 	return 0;
 }
 
@@ -3200,8 +3193,12 @@ Session::config_changed (std::string p, bool ours)
 
 		first_file_data_format_reset = false;
 
-	} else if (p == "slave-source") {
-				set_slave_source (Config->get_slave_source());
+	} else if (p == "external-sync") {
+		if (!config.get_external_sync()) {
+			drop_sync_source ();
+		} else {
+			use_sync_source (config.get_sync_source());
+		}
 	} else if (p == "remote-model") {
 		set_remote_control_ids ();
 	}  else if (p == "denormal-model") {
diff --git a/libs/ardour/session_transport.cc b/libs/ardour/session_transport.cc
index 10429e9639..b7377d7dc6 100644
--- a/libs/ardour/session_transport.cc
+++ b/libs/ardour/session_transport.cc
@@ -79,9 +79,9 @@ Session::request_input_change_handling ()
 }
 
 void
-Session::request_slave_source (SlaveSource src)
+Session::request_sync_source (SyncSource src)
 {
-	Event* ev = new Event (Event::SetSlaveSource, Event::Add, Event::Immediate, 0, 0.0);
+	Event* ev = new Event (Event::SetSyncSource, Event::Add, Event::Immediate, 0, 0.0);
 	bool seamless;
 
 	seamless = Config->get_seamless_loop ();
@@ -97,7 +97,7 @@ Session::request_slave_source (SlaveSource src)
 	/* save value of seamless from before the switch */
 	_was_seamless = seamless;
 
-	ev->slave = src;
+	ev->sync_source = src;
 	queue_event (ev);
 }
 
@@ -230,7 +230,7 @@ Session::realtime_stop (bool abort, bool clear_state)
 		waiting_for_sync_offset = true;
 	}
 
-	transport_sub_state = ((Config->get_slave_source() == None && config.get_auto_return()) ? AutoReturning : 0);
+	transport_sub_state = ((!config.get_external_sync()&& config.get_auto_return()) ? AutoReturning : 0);
 }
 
 void
@@ -439,7 +439,7 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 	}
 
 	bool const auto_return_enabled =
-		(Config->get_slave_source() == None && config.get_auto_return());
+		(!config.get_external_sync() && config.get_auto_return());
 
 	if (auto_return_enabled ||
 	    (ptw & PostTransportLocate) ||
@@ -571,7 +571,7 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 
 	/* and start it up again if relevant */
 
-	if ((ptw & PostTransportLocate) && Config->get_slave_source() == None && pending_locate_roll) {
+	if ((ptw & PostTransportLocate) && !config.get_external_sync() && pending_locate_roll) {
 		request_transport_speed (1.0);
 		pending_locate_roll = false;
 	}
@@ -1106,7 +1106,7 @@ Session::post_transport ()
 
 	if (ptw & PostTransportLocate) {
 
-		if (((Config->get_slave_source() == None && (auto_play_legal && config.get_auto_play())) && !_exporting) || (ptw & PostTransportRoll)) {
+		if (((!config.get_external_sync() && (auto_play_legal && config.get_auto_play())) && !_exporting) || (ptw & PostTransportRoll)) {
 			start_transport ();
 
 		} else {
@@ -1142,9 +1142,8 @@ Session::reset_rf_scale (nframes_t motion)
 }
 
 void
-Session::set_slave_source (SlaveSource src)
+Session::drop_sync_source ()
 {
-	bool reverse = false;
 	bool non_rt_required = false;
 
 	if (_transport_speed) {
@@ -1152,22 +1151,42 @@ Session::set_slave_source (SlaveSource src)
 		return;
 	}
 
-//	if (src == JACK && Config->get_jack_time_master()) {
-//		return;
-//	}
-
 	delete _slave;
 	_slave = 0;
 
-	if (_transport_speed < 0.0) {
-		reverse = true;
+	boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
+	for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
+		if (!(*i)->hidden()) {
+			if ((*i)->realtime_set_speed ((*i)->speed(), true)) {
+				non_rt_required = true;
+			}
+			(*i)->set_slaved (0);
+		}
 	}
 
-	switch (src) {
-	case None:
-		stop_transport ();
-		break;
+	if (non_rt_required) {
+		add_post_transport_work (PostTransportSpeed);
+		_butler->schedule_transport_work ();
+	}
 
+	set_dirty();
+}
+
+void
+Session::use_sync_source (SyncSource src)
+{
+	bool reverse = false;
+	bool non_rt_required = false;
+
+	if (_transport_speed) {
+		error << _("please stop the transport before adjusting slave settings") << endmsg;
+		return;
+	}
+
+	delete _slave;
+	_slave = 0;
+
+	switch (src) {
 	case MTC:
 		if (_mtc_port) {
 			try {
@@ -1206,8 +1225,6 @@ Session::set_slave_source (SlaveSource src)
 
 	};
 
-	Config->set_slave_source (src);
-
 	boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 	for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 		if (!(*i)->hidden()) {
diff --git a/libs/ardour/utils.cc b/libs/ardour/utils.cc
index abed926983..af90c935c9 100644
--- a/libs/ardour/utils.cc
+++ b/libs/ardour/utils.cc
@@ -331,14 +331,10 @@ edit_mode_to_string (EditMode mode)
 	}
 }
 
-SlaveSource
-string_to_slave_source (string str)
+SyncSource
+string_to_sync_source (string str)
 {
-	if (str == _("Internal")) {
-		return None;
-	}
-
-	if (str == _("MTC")) {
+	if (str == _("MIDI Timecode")) {
 		return MTC;
 	}
 
@@ -350,29 +346,26 @@ string_to_slave_source (string str)
 		return JACK;
 	}
 
-	fatal << string_compose (_("programming error: unknown slave source string \"%1\""), str) << endmsg;
+	fatal << string_compose (_("programming error: unknown sync source string \"%1\""), str) << endmsg;
 	/*NOTREACHED*/
-	return None;
+	return JACK;
 }
 
 const char*
-slave_source_to_string (SlaveSource src)
+sync_source_to_string (SyncSource src)
 {
 	switch (src) {
 	case JACK:
 		return _("JACK");
 
 	case MTC:
-		return _("MTC");
+		return _("MIDI Timecode");
 
 	case MIDIClock:
 		return _("MIDI Clock");
-
-	default:
-	case None:
-		return _("Internal");
-
 	}
+	/* GRRRR .... stupid, stupid gcc - you can't get here from there, all enum values are handled */
+	return _("JACK");
 }
 
 float
diff --git a/libs/midi++2/factory.cc b/libs/midi++2/factory.cc
index 1980ac508b..40cadd2390 100644
--- a/libs/midi++2/factory.cc
+++ b/libs/midi++2/factory.cc
@@ -110,6 +110,12 @@ PortFactory::ignore_duplicate_devices (Port::Type type)
 		break;
 #endif // WITH_ALSA
 
+#ifdef WITH_JACK_MIDI
+	case Port::JACK_Midi:
+		ret = true;
+		break;
+#endif // WITH_JACK_MIDI
+
 #if WITH_COREMIDI
 	case Port::CoreMidi_MidiPort:
 		ret = true;
diff --git a/libs/midi++2/manager.cc b/libs/midi++2/manager.cc
index ab03688e49..ab37073afd 100644
--- a/libs/midi++2/manager.cc
+++ b/libs/midi++2/manager.cc
@@ -70,12 +70,6 @@ Manager::add_port (const XMLNode& node)
 	PortMap::iterator existing;
 	pair<string, Port *> newpair;
 
-	/* do not allow multiple ports with the same tag. if attempted, just return the existing
-	   port with the same tag. XXX this is really caused by the mess of setup_midi() being
-	   called twice in Ardour, once in the global init() function and once after the user RC file
-	   has been loaded (there may be extra ports in it). 
-	 */
-
 	if ((existing = ports_by_tag.find (desc.tag)) != ports_by_tag.end()) {
 
 		port = (*existing).second;
@@ -150,6 +144,7 @@ Manager::add_port (const XMLNode& node)
 	}
 	
 	port = factory.create_port (node, api_data);
+
 	
 	if (port == 0) {
 		return 0;
diff --git a/libs/midi++2/wscript b/libs/midi++2/wscript
index 14974581a9..735d513179 100644
--- a/libs/midi++2/wscript
+++ b/libs/midi++2/wscript
@@ -1,6 +1,7 @@
 #!/usr/bin/env python
 import autowaf
 import os
+import sys
 
 # Version of this package (even if built as a child)
 MAJOR = '2'
@@ -36,10 +37,6 @@ def configure(conf):
 	autowaf.check_pkg(conf, 'libxml-2.0', uselib_store='XML')
 	autowaf.check_pkg(conf, 'sigc++-2.0', uselib_store='SIGCPP', atleast_version='2.0')
 
-	# TODO
-	conf.env['SYSMIDI'] = 'JACK MIDI'
-	conf.env.append_value('CXXFLAGS', '-DWITH_JACK_MIDI')
-
 	# Boost headers
 	autowaf.check_header(conf, 'boost/shared_ptr.hpp')
 	autowaf.check_header(conf, 'boost/weak_ptr.hpp')
@@ -61,12 +58,17 @@ def build(bld):
 		mtc.cc
 		version.cc
 	'''
-	if bld.env['SYSMIDI'] == 'JACK MIDI':
-		obj.source += ' jack_midiport.cc '
-	elif bld.env['SYSMIDI'] == 'Alsa Sequencer':
-		obj.source += ' alsa_sequencer_midiport.cc '
-	elif bld.env['SYSMIDI'] == 'CoreMIDI':
+	# everybody loves JACK
+	obj.source += ' jack_midiport.cc '
+	obj.cxxflags = [ '-DWITH_JACK_MIDI' ]
+	if sys.platform == 'darwin':
+		# OS X
 		obj.source += ' coremidi_midiport.cc '
+		obj.cxxflags += [ '-DWITH_COREMIDI' ]
+	else :
+		# linux
+		obj.source += ' alsa_sequencer_midiport.cc '
+		obj.cxxflags += [ '-DWITH_ALSA' ]
 	obj.export_incdirs = ['.']
 	obj.includes     = ['.']
 	obj.name         = 'libmidipp'