* first implementation of MIDI Clock Slave support

git-svn-id: svn://localhost/ardour2/branches/3.0@3652 d708f5d6-7413-0410-9779-e7cbd77b26cf

12 files changed, 894 insertions, 715 deletions

diff --git a/libs/ardour/SConscript b/libs/ardour/SConscript
index b50aecbcb3..44f4718384 100644
--- a/libs/ardour/SConscript
+++ b/libs/ardour/SConscript
@@ -92,6 +92,7 @@ midi_stretch.cc
 midi_track.cc
 mix.cc
 mtc_slave.cc
+midi_clock_slave.cc
 named_selection.cc
 note.cc
 panner.cc
diff --git a/libs/ardour/ardour/ardour.h b/libs/ardour/ardour/ardour.h
index 6f653f10bf..fecd0fcf4e 100644
--- a/libs/ardour/ardour/ardour.h
+++ b/libs/ardour/ardour/ardour.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 1999 Paul Davis 
+    Copyright (C) 1999 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -51,9 +51,9 @@ namespace ARDOUR {
 	int cleanup ();
 
 	std::string get_ardour_revision ();
-	
+
 	void find_bindings_files (std::map<std::string,std::string>&);
-	
+
 	const layer_t max_layer = UCHAR_MAX;
 
 	microseconds_t get_microseconds ();
@@ -82,6 +82,7 @@ namespace ARDOUR {
 extern MIDI::Port* default_mmc_port;
 extern MIDI::Port* default_mtc_port;
 extern MIDI::Port* default_midi_port;
+extern MIDI::Port *default_midi_clock_port;
 
 #endif /* __ardour_ardour_h__ */
 
diff --git a/libs/ardour/ardour/configuration_vars.h b/libs/ardour/ardour/configuration_vars.h
index 4e2a14c07b..7a7a2ce419 100644
--- a/libs/ardour/ardour/configuration_vars.h
+++ b/libs/ardour/ardour/configuration_vars.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2000-2007 Paul Davis 
+    Copyright (C) 2000-2007 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -30,11 +30,13 @@ CONFIG_VARIABLE (std::string, auditioner_output_right, "auditioner-output-right"
 CONFIG_VARIABLE (std::string, mtc_port_name, "mtc-port-name", "default")
 CONFIG_VARIABLE (std::string, mmc_port_name, "mmc-port-name", "default")
 CONFIG_VARIABLE (std::string, midi_port_name, "midi-port-name", "default")
+CONFIG_VARIABLE (std::string, midi_clock_port_name, "midi-clock-port-name", "default")
 CONFIG_VARIABLE (bool, trace_midi_input, "trace-midi-input", false)
 CONFIG_VARIABLE (bool, trace_midi_output, "trace-midi-output", false)
 CONFIG_VARIABLE (bool, send_mtc, "send-mtc", false)
 CONFIG_VARIABLE (bool, send_mmc, "send-mmc", true)
 CONFIG_VARIABLE (bool, mmc_control, "mmc-control", true)
+CONFIG_VARIABLE (bool, midi_clock_control, "midi-clock-control", false)
 CONFIG_VARIABLE (bool, midi_feedback, "midi-feedback", false)
 CONFIG_VARIABLE (uint8_t, mmc_receive_device_id, "mmc-receive-device-id", 0)
 CONFIG_VARIABLE (uint8_t, mmc_send_device_id, "mmc-send-device-id", 0)
@@ -139,7 +141,7 @@ CONFIG_VARIABLE (nframes_t, over_length_short, "over-length-short", 2)
 CONFIG_VARIABLE (nframes_t, over_length_long, "over-length-long", 10)
 
 /* miscellany */
-	
+
 CONFIG_VARIABLE (bool, hiding_groups_deactivates_groups, "hiding-groups-deactivates-groups", true)
 CONFIG_VARIABLE (bool, verify_remove_last_capture, "verify-remove-last-capture", true)
 CONFIG_VARIABLE (bool, no_new_session_dialog, "no-new-session-dialog", false)
diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index b718d751b4..00cbc9922e 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2000 Paul Davis 
+    Copyright (C) 2000 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -46,8 +46,8 @@
 #include <midi++/types.h>
 #include <midi++/mmc.h>
 
-#include <pbd/stateful.h> 
-#include <pbd/destructible.h> 
+#include <pbd/stateful.h>
+#include <pbd/destructible.h>
 
 #include <ardour/ardour.h>
 #include <ardour/configuration.h>
@@ -150,7 +150,7 @@ class Session : public PBD::StatefulDestructible
 		    InputConfigurationChange,
 		    SetAudioRange,
 		    SetPlayRange,
-		    
+
 		    /* only one of each of these events
 		       can be queued at any one time
 		    */
@@ -165,7 +165,7 @@ class Session : public PBD::StatefulDestructible
 		    Replace,
 		    Clear
 	    };
-		
+
 		Type           type;
 	    Action         action;
 	    nframes_t action_frame;
@@ -186,14 +186,14 @@ class Session : public PBD::StatefulDestructible
 	    list<MusicRange>     music_range;
 
 	    Event(Type t, Action a, nframes_t when, nframes_t where, float spd, bool yn = false)
-		    : type (t), 
+		    : type (t),
 		      action (a),
 		      action_frame (when),
 		      target_frame (where),
 		      speed (spd),
 		      yes_or_no (yn) {}
 
-	    void set_ptr (void* p) { 
+	    void set_ptr (void* p) {
 		    ptr = p;
 	    }
 
@@ -242,7 +242,7 @@ class Session : public PBD::StatefulDestructible
 		 uint32_t n_physical_in,
 		 uint32_t n_physical_out,
 		 nframes_t initial_length);
-	
+
 	virtual ~Session ();
 
 	string path() const { return _path; }
@@ -265,20 +265,20 @@ class Session : public PBD::StatefulDestructible
 	static sigc::signal<void> AutoBindingOff;
 
 	static sigc::signal<void,std::string> Dialog;
-	
+
 	std::string sound_dir (bool with_path = true) const;
 	std::string peak_dir () const;
 	std::string dead_sound_dir () const;
 	std::string automation_dir () const;
 	std::string analysis_dir() const;
-	
+
 	int ensure_subdirs ();
 
 	Glib::ustring peak_path (Glib::ustring) const;
 
 	static string change_audio_path_by_name (string oldpath, string oldname, string newname, bool destructive);
 	static string change_midi_path_by_name (string oldpath, string oldname, string newname, bool destructive);
-	
+
 	string peak_path_from_audio_path (string) const;
 	string audio_path_from_name (string, uint32_t nchans, uint32_t chan, bool destructive);
 	string midi_path_from_name (string);
@@ -288,7 +288,7 @@ class Session : public PBD::StatefulDestructible
 	BufferSet& get_silent_buffers (ChanCount count = ChanCount::ZERO);
 	BufferSet& get_scratch_buffers (ChanCount count = ChanCount::ZERO);
 	BufferSet& get_mix_buffers (ChanCount count = ChanCount::ZERO);
-	
+
 	void add_diskstream (boost::shared_ptr<Diskstream>);
 	boost::shared_ptr<Diskstream> diskstream_by_id (const PBD::ID& id);
 	boost::shared_ptr<Diskstream> diskstream_by_name (string name);
@@ -298,17 +298,17 @@ class Session : public PBD::StatefulDestructible
 	void refill_all_diskstream_buffers ();
 	uint32_t audio_diskstream_buffer_size() const { return audio_dstream_buffer_size; }
 	uint32_t midi_diskstream_buffer_size() const { return midi_dstream_buffer_size; }
-	
+
 	uint32_t get_next_diskstream_id() const { return n_diskstreams(); }
 	uint32_t n_diskstreams() const;
-	
+
 	typedef std::list<boost::shared_ptr<Diskstream> > DiskstreamList;
-	typedef std::list<boost::shared_ptr<Route> >      RouteList; 
-	
+	typedef std::list<boost::shared_ptr<Route> >      RouteList;
+
 	boost::shared_ptr<RouteList> get_routes() const {
 		return routes.reader ();
 	}
-	
+
 	uint32_t nroutes() const { return routes.reader()->size(); }
 	uint32_t ntracks () const;
 	uint32_t nbusses () const;
@@ -316,7 +316,7 @@ class Session : public PBD::StatefulDestructible
 	struct RoutePublicOrderSorter {
 	    bool operator() (boost::shared_ptr<Route>, boost::shared_ptr<Route> b);
 	};
-	
+
 	template<class T> void foreach_route (T *obj, void (T::*func)(Route&));
 	template<class T> void foreach_route (T *obj, void (T::*func)(boost::shared_ptr<Route>));
 	template<class T, class A> void foreach_route (T *obj, void (T::*func)(Route&, A), A arg);
@@ -327,7 +327,7 @@ class Session : public PBD::StatefulDestructible
 
 	bool route_name_unique (string) const;
 
-	bool get_record_enabled() const { 
+	bool get_record_enabled() const {
 		return (record_status () >= Enabled);
 	}
 
@@ -343,7 +343,7 @@ class Session : public PBD::StatefulDestructible
 	void maybe_enable_record ();
 	void disable_record (bool rt_context, bool force = false);
 	void step_back_from_record ();
-	
+
 	void maybe_write_autosave ();
 
 	/* Proxy signal for region hidden changes */
@@ -351,9 +351,9 @@ class Session : public PBD::StatefulDestructible
 	sigc::signal<void,boost::shared_ptr<Region> > RegionHiddenChange;
 
 	/* Emitted when all i/o connections are complete */
-	
+
 	sigc::signal<void> IOConnectionsComplete;
-	
+
 	/* Record status signals */
 
 	sigc::signal<void> RecordStateChanged;
@@ -442,10 +442,10 @@ class Session : public PBD::StatefulDestructible
 	void remove_state (string snapshot_name);
 	void rename_state (string old_name, string new_name);
 	void remove_pending_capture_state ();
-	
+
 	sigc::signal<void,string> StateSaved;
 	sigc::signal<void> StateReady;
-	
+
 	vector<string*>* possible_states() const;
 	static vector<string*>* possible_states(string path);
 
@@ -499,14 +499,14 @@ class Session : public PBD::StatefulDestructible
 
 	std::list<boost::shared_ptr<AudioTrack> > new_audio_track (int input_channels, int output_channels, TrackMode mode = Normal, uint32_t how_many = 1);
 	RouteList new_audio_route (int input_channels, int output_channels, uint32_t how_many);
-	
+
 	std::list<boost::shared_ptr<MidiTrack> > new_midi_track (TrackMode mode = Normal, uint32_t how_many = 1);
 	//boost::shared_ptr<Route>     new_midi_route (uint32_t how_many = 1);
 
 	void   remove_route (boost::shared_ptr<Route>);
 	void   resort_routes ();
 	void   resort_routes_using (boost::shared_ptr<RouteList>);
-	
+
 	void   set_remote_control_ids();
 
 	AudioEngine & engine() { return _engine; }
@@ -563,18 +563,18 @@ class Session : public PBD::StatefulDestructible
 	float       transport_speed() const { return _transport_speed; }
 	bool        transport_stopped() const { return _transport_speed == 0.0f; }
 	bool        transport_rolling() const { return _transport_speed != 0.0f; }
-	
+
 	void set_silent (bool yn);
 	bool silent () { return _silent; }
 
 	int jack_slave_sync (nframes_t);
 
 	TempoMap& tempo_map() { return *_tempo_map; }
-	
+
 	/* region info  */
 
 	void add_regions (std::vector<boost::shared_ptr<Region> >&);
-	
+
 	sigc::signal<void,boost::weak_ptr<Region> > RegionAdded;
 	sigc::signal<void,std::vector<boost::weak_ptr<Region> >& > RegionsAdded;
 	sigc::signal<void,boost::weak_ptr<Region> > RegionRemoved;
@@ -584,7 +584,7 @@ class Session : public PBD::StatefulDestructible
 	string path_from_region_name (DataType type, string name, string identifier);
 
 	boost::shared_ptr<Region> find_whole_file_parent (boost::shared_ptr<Region const>);
-	
+
 	void find_equivalent_playlist_regions (boost::shared_ptr<Region>, std::vector<boost::shared_ptr<Region> >& result);
 
 	boost::shared_ptr<Region>      XMLRegionFactory (const XMLNode&, bool full);
@@ -597,16 +597,16 @@ class Session : public PBD::StatefulDestructible
 
 	struct import_status : public InterThreadInfo {
 	    string doing_what;
-	    
+
 	    /* control info */
 	    SrcQuality quality;
 	    volatile bool freeze;
 	    std::vector<Glib::ustring> paths;
 	    bool replace_existing_source;
-	    
+
 	    /* result */
 	    SourceList sources;
-	    
+
 	};
 
 	void import_audiofiles (import_status&);
@@ -640,7 +640,7 @@ class Session : public PBD::StatefulDestructible
 	   "yes, delete this playlist" and 1 for "no, don't delete
 	   this playlist.
 	*/
-	
+
 	sigc::signal<int,boost::shared_ptr<ARDOUR::Playlist> > AskAboutPlaylistDeletion;
 
 	/* handlers should return 0 for "ignore the rate mismatch"
@@ -654,7 +654,7 @@ class Session : public PBD::StatefulDestructible
 	*/
 
 	static sigc::signal<int> AskAboutPendingState;
-	
+
 	boost::shared_ptr<AudioFileSource> create_audio_source_for_session (ARDOUR::AudioDiskstream&, uint32_t which_channel, bool destructive);
 
 	boost::shared_ptr<MidiSource> create_midi_source_for_session (ARDOUR::MidiDiskstream&);
@@ -687,7 +687,7 @@ class Session : public PBD::StatefulDestructible
 	/* Curves and AutomationLists (TODO when they go away) */
 	void add_curve(Curve*);
 	void add_automation_list(AutomationList*);
-	
+
 	/* fade curves */
 
 	float get_default_fade_length () const { return default_fade_msecs; }
@@ -701,7 +701,7 @@ class Session : public PBD::StatefulDestructible
 	void audition_region (boost::shared_ptr<Region>);
 	void cancel_audition ();
 	bool is_auditioning () const;
-	
+
 	sigc::signal<void,bool> AuditionActive;
 
 	/* flattening stuff */
@@ -712,7 +712,7 @@ class Session : public PBD::StatefulDestructible
 	int freeze (InterThreadInfo&);
 
 	/* session-wide solo/mute/rec-enable */
-	
+
 	bool soloing() const { return currently_soloing; }
 
 	void set_all_solo (bool);
@@ -720,7 +720,7 @@ class Session : public PBD::StatefulDestructible
 
 	sigc::signal<void,bool> SoloActive;
 	sigc::signal<void> SoloChanged;
-	
+
 	void record_disenable_all ();
 	void record_enable_all ();
 
@@ -730,15 +730,15 @@ class Session : public PBD::StatefulDestructible
 	boost::shared_ptr<IO> master_out() const { return _master_out; }
 
 	/* insert/send management */
-	
+
 	uint32_t n_port_inserts() const { return _port_inserts.size(); }
 	uint32_t n_plugin_inserts() const { return _plugin_inserts.size(); }
 	uint32_t n_sends() const { return _sends.size(); }
-	
-	static void set_disable_all_loaded_plugins (bool yn) { 
+
+	static void set_disable_all_loaded_plugins (bool yn) {
 		_disable_all_loaded_plugins = yn;
 	}
-	static bool get_disable_all_loaded_plugins() { 
+	static bool get_disable_all_loaded_plugins() {
 		return _disable_all_loaded_plugins;
 	}
 
@@ -748,7 +748,7 @@ class Session : public PBD::StatefulDestructible
 	void mark_insert_id (uint32_t);
 
 	/* s/w "RAID" management */
-	
+
 	nframes_t available_capture_duration();
 
 	/* I/O bundles */
@@ -767,23 +767,26 @@ class Session : public PBD::StatefulDestructible
 	int set_mtc_port (string port_tag);
 	int set_mmc_port (string port_tag);
 	int set_midi_port (string port_tag);
+	int set_midi_clock_port (string port_tag);
 	MIDI::Port *mtc_port() const { return _mtc_port; }
 	MIDI::Port *mmc_port() const { return _mmc_port; }
 	MIDI::Port *midi_port() const { return _midi_port; }
+	MIDI::Port *midi_clock_port() const { return _midi_clock_port; }
 
 	sigc::signal<void> MTC_PortChanged;
 	sigc::signal<void> MMC_PortChanged;
 	sigc::signal<void> MIDI_PortChanged;
+	sigc::signal<void> MIDIClock_PortChanged;
 
 	void set_trace_midi_input (bool, MIDI::Port* port = 0);
 	void set_trace_midi_output (bool, MIDI::Port* port = 0);
 
 	bool get_trace_midi_input(MIDI::Port *port = 0);
 	bool get_trace_midi_output(MIDI::Port *port = 0);
-	
+
 	void set_mmc_receive_device_id (uint32_t id);
 	void set_mmc_send_device_id (uint32_t id);
-	
+
 	/* Scrubbing */
 
 	void start_scrub (nframes_t where);
@@ -806,7 +809,7 @@ class Session : public PBD::StatefulDestructible
 	}
 
 	UndoHistory& history() { return _history; }
-	
+
 	uint32_t undo_depth() const { return _history.undo_depth(); }
 	uint32_t redo_depth() const { return _history.redo_depth(); }
 	string next_undo() const { return _history.next_undo(); }
@@ -839,7 +842,7 @@ class Session : public PBD::StatefulDestructible
 		GlobalRouteBooleanState before, after;
 		Session& sess;
 		void* src;
-		
+
 	};
 
 	class GlobalSoloStateCommand : public GlobalRouteStateCommand
@@ -896,7 +899,7 @@ class Session : public PBD::StatefulDestructible
 	/* clicking */
 
 	boost::shared_ptr<IO>  click_io() { return _click_io; }
-		
+
 	/* disk, buffer loads */
 
 	uint32_t playback_load ();
@@ -906,7 +909,7 @@ class Session : public PBD::StatefulDestructible
 
 	void reset_playback_load_min ();
 	void reset_capture_load_min ();
-	
+
 	float read_data_rate () const;
 	float write_data_rate () const;
 
@@ -929,7 +932,7 @@ class Session : public PBD::StatefulDestructible
 		TransportContext,
 		ExportContext
 	};
-	
+
 	/* VST support */
 
 	static long vst_callback (AEffect* effect,
@@ -938,7 +941,7 @@ class Session : public PBD::StatefulDestructible
 				  long value,
 				  void* ptr,
 				  float opt);
-	
+
 	typedef float (*compute_peak_t)          (Sample *, nframes_t, float);
 	typedef void  (*find_peaks_t)            (Sample *, nframes_t, float *, float*);
 	typedef void  (*apply_gain_to_buffer_t)  (Sample *, nframes_t, float);
@@ -974,11 +977,11 @@ class Session : public PBD::StatefulDestructible
 	friend class Route;
 	void schedule_curve_reallocation ();
 	void update_latency_compensation (bool, bool);
-	
+
   private:
 	int  create (bool& new_session, const string& mix_template, nframes_t initial_length);
 	void destroy ();
-	
+
 	nframes_t compute_initial_length ();
 
 	enum SubState {
@@ -995,7 +998,7 @@ class Session : public PBD::StatefulDestructible
 	*/
 
 	typedef void (Session::*process_function_type)(nframes_t);
-	
+
 	AudioEngine&            _engine;
 	mutable gint             processing_prohibited;
 	process_function_type    process_function;
@@ -1039,13 +1042,13 @@ class Session : public PBD::StatefulDestructible
 	void update_latency_compensation_proxy (void* ignored);
 
 	void ensure_buffers (ChanCount howmany);
-	
+
 	void process_scrub          (nframes_t);
 	void process_without_events (nframes_t);
 	void process_with_events    (nframes_t);
 	void process_audition       (nframes_t);
 	int  process_export         (nframes_t, ARDOUR::ExportSpecification*);
-	
+
 	/* slave tracking */
 
 	static const int delta_accumulator_size = 25;
@@ -1054,13 +1057,13 @@ class Session : public PBD::StatefulDestructible
 	long average_slave_delta;
 	int  average_dir;
 	bool have_first_delta_accumulator;
-	
+
 	enum SlaveState {
 		Stopped,
 		Waiting,
 		Running
 	};
-	
+
 	SlaveState slave_state;
 	nframes_t slave_wait_end;
 
@@ -1116,6 +1119,7 @@ class Session : public PBD::StatefulDestructible
 	MIDI::Port*             _mmc_port;
 	MIDI::Port*             _mtc_port;
 	MIDI::Port*             _midi_port;
+	MIDI::Port*             _midi_clock_port;
 	string                  _path;
 	string                  _name;
 	bool                     session_send_mmc;
@@ -1153,7 +1157,7 @@ class Session : public PBD::StatefulDestructible
 	bool              pending_locate_flush;
 	bool              pending_abort;
 	bool              pending_auto_loop;
-	
+
 	Sample*           butler_mixdown_buffer;
 	float*            butler_gain_buffer;
 	pthread_t         butler_thread;
@@ -1164,7 +1168,7 @@ class Session : public PBD::StatefulDestructible
 	int               butler_request_pipe[2];
 
 	inline bool transport_work_requested() const { return g_atomic_int_get(&butler_should_do_transport_work); }
-	
+
 	struct ButlerRequest {
 	    enum Type {
 		    Wake,
@@ -1191,8 +1195,8 @@ class Session : public PBD::StatefulDestructible
 		PostTransportInputChange        = 0x20000,
 		PostTransportCurveRealloc       = 0x40000
 	};
-	
-	static const PostTransportWork ProcessCannotProceedMask = 
+
+	static const PostTransportWork ProcessCannotProceedMask =
 		PostTransportWork (PostTransportInputChange|
 				   PostTransportSpeed|
 				   PostTransportReverse|
@@ -1201,7 +1205,7 @@ class Session : public PBD::StatefulDestructible
 				   PostTransportAudition|
 				   PostTransportLocate|
 				   PostTransportStop);
-	
+
 	PostTransportWork post_transport_work;
 
 	void             summon_butler ();
@@ -1264,7 +1268,7 @@ class Session : public PBD::StatefulDestructible
 	int  midi_read (MIDI::Port *);
 
 	void enable_record ();
-	
+
 	void increment_transport_position (uint32_t val) {
 		if (max_frames - val < _transport_frame) {
 			_transport_frame = max_frames;
@@ -1297,6 +1301,10 @@ class Session : public PBD::StatefulDestructible
 	void spp_continue (MIDI::Parser&);
 	void spp_stop (MIDI::Parser&);
 
+	void midi_clock_start (MIDI::Parser&);
+	void midi_clock_continue (MIDI::Parser&);
+	void midi_clock_stop (MIDI::Parser&);
+
 	void mmc_deferred_play (MIDI::MachineControl &);
 	void mmc_stop (MIDI::MachineControl &);
 	void mmc_step (MIDI::MachineControl &, int);
@@ -1327,7 +1335,7 @@ class Session : public PBD::StatefulDestructible
 	nframes_t  outbound_mtc_smpte_frame;
 	SMPTE::Time transmitting_smpte_time;
 	int next_quarter_frame_to_send;
-	
+
 	double _frames_per_smpte_frame; /* has to be floating point because of drop frame */
 	nframes_t _frames_per_hour;
 	nframes_t _smpte_frames_per_hour;
@@ -1339,28 +1347,28 @@ class Session : public PBD::StatefulDestructible
 	bool           last_smpte_valid;
 	nframes_t last_smpte_when;
 	SMPTE::Time    last_smpte;
-	
+
 	bool _send_smpte_update; ///< Flag to send a full frame (SMPTE) MTC message this cycle
 
 	int send_full_time_code(nframes_t nframes);
 	int send_midi_time_code_for_cycle(nframes_t nframes);
 
 	nframes_t adjust_apparent_position (nframes_t frames);
-	
+
 	void reset_record_status ();
-	
+
 	int no_roll (nframes_t nframes, nframes_t offset);
-	
+
 	bool non_realtime_work_pending() const { return static_cast<bool>(post_transport_work); }
 	bool process_can_proceed() const { return !(post_transport_work & ProcessCannotProceedMask); }
 
 	struct MIDIRequest {
-	    
+
 	    enum Type {
 		    PortChange,
 		    Quit
 	    };
-	    
+
 	    Type type;
 
 	    MIDIRequest () {}
@@ -1419,7 +1427,7 @@ class Session : public PBD::StatefulDestructible
 
 	/* disk-streams */
 
-	SerializedRCUManager<DiskstreamList>  diskstreams; 
+	SerializedRCUManager<DiskstreamList>  diskstreams;
 
 	uint32_t audio_dstream_buffer_size;
 	uint32_t midi_dstream_buffer_size;
@@ -1439,7 +1447,7 @@ class Session : public PBD::StatefulDestructible
 
 	bool       solo_update_disabled;
 	bool       currently_soloing;
-	
+
 	void route_mute_changed (void *src);
 	void route_solo_changed (void *src, boost::weak_ptr<Route>);
 	void catch_up_on_solo ();
@@ -1452,7 +1460,7 @@ class Session : public PBD::StatefulDestructible
 	mutable Glib::Mutex region_lock;
 	typedef map<PBD::ID,boost::shared_ptr<Region> > RegionList;
 	RegionList regions;
-	
+
 	void add_region (boost::shared_ptr<Region>);
 	void region_changed (Change, boost::weak_ptr<Region>);
 	void remove_region (boost::weak_ptr<Region>);
@@ -1460,7 +1468,7 @@ class Session : public PBD::StatefulDestructible
 	int load_regions (const XMLNode& node);
 
 	/* SOURCES */
-	
+
 	mutable Glib::Mutex source_lock;
 	typedef std::map<PBD::ID,boost::shared_ptr<Source> > SourceMap;
 
@@ -1468,7 +1476,7 @@ class Session : public PBD::StatefulDestructible
 
   public:
 	SourceMap get_sources() { return sources; }
-    
+
   private:
 
 
@@ -1478,7 +1486,7 @@ class Session : public PBD::StatefulDestructible
 	boost::shared_ptr<Source> XMLSourceFactory (const XMLNode&);
 
 	/* PLAYLISTS */
-	
+
 	mutable Glib::Mutex playlist_lock;
 	typedef set<boost::shared_ptr<Playlist> > PlaylistList;
 	PlaylistList playlists;
@@ -1529,7 +1537,7 @@ class Session : public PBD::StatefulDestructible
 	int flatten_one_track (AudioTrack&, nframes_t start, nframes_t cnt);
 
 	/* INSERT AND SEND MANAGEMENT */
-	
+
 	list<PortInsert *>              _port_inserts;
 	list<PluginInsert *>            _plugin_inserts;
 	list<Send *>                    _sends;
@@ -1547,8 +1555,8 @@ class Session : public PBD::StatefulDestructible
 	struct space_and_path {
 	    uint32_t blocks; /* 4kB blocks */
 	    string path;
-	    
-	    space_and_path() { 
+
+	    space_and_path() {
 		    blocks = 0;
 	    }
 	};
@@ -1558,14 +1566,14 @@ class Session : public PBD::StatefulDestructible
 		    return a.blocks > b.blocks;
 	    }
 	};
-	
+
 	void setup_raid_path (string path);
 
 	vector<space_and_path> session_dirs;
 	vector<space_and_path>::iterator last_rr_session_dir;
 	uint32_t _total_free_4k_blocks;
 	Glib::Mutex space_lock;
-	
+
 	string get_best_session_directory_for_new_source ();
 	void refresh_disk_space ();
 
@@ -1612,9 +1620,9 @@ class Session : public PBD::StatefulDestructible
 	    nframes_t offset;
 	    const Sample *data;
 
-	    Click (nframes_t s, nframes_t d, const Sample *b) 
+	    Click (nframes_t s, nframes_t d, const Sample *b)
 		    : start (s), duration (d), data (b) { offset = 0; }
-	    
+
 	    void *operator new(size_t ignored) {
 		    return pool.alloc ();
 	    };
@@ -1626,7 +1634,7 @@ class Session : public PBD::StatefulDestructible
 	  private:
 	    static Pool pool;
 	};
- 
+
 	typedef list<Click*> Clicks;
 
 	Clicks          clicks;
@@ -1649,7 +1657,7 @@ class Session : public PBD::StatefulDestructible
 	void   click (nframes_t start, nframes_t nframes, nframes_t offset);
 
 	vector<Route*> master_outs;
-	
+
 	/* range playback */
 
 	list<AudioRange> current_audio_range;
@@ -1659,7 +1667,7 @@ class Session : public PBD::StatefulDestructible
 
 	/* main outs */
 	uint32_t main_outs;
-	
+
 	boost::shared_ptr<IO> _master_out;
 	boost::shared_ptr<IO> _control_out;
 
@@ -1702,10 +1710,10 @@ class Session : public PBD::StatefulDestructible
 	void config_changed (const char*);
 
 	XMLNode& get_control_protocol_state ();
-	
+
 	void set_history_depth (uint32_t depth);
 	void sync_order_keys ();
-	
+
 	static bool _disable_all_loaded_plugins;
 };
 
diff --git a/libs/ardour/ardour/slave.h b/libs/ardour/ardour/slave.h
index 509f8fa9d2..9df8574430 100644
--- a/libs/ardour/ardour/slave.h
+++ b/libs/ardour/ardour/slave.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2002 Paul Davis 
+    Copyright (C) 2002 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -50,6 +50,18 @@ class Slave {
 	virtual bool is_always_synced() const { return false; }
 };
 
+struct SafeTime {
+    int guard1;
+    nframes_t   position;
+    nframes_t   timestamp;
+    int guard2;
+
+    SafeTime() {
+	    guard1 = 0;
+	    guard2 = 0;
+	    timestamp = 0;
+    }
+};
 
 class MTC_Slave : public Slave, public sigc::trackable {
   public:
@@ -59,9 +71,9 @@ class MTC_Slave : public Slave, public sigc::trackable {
 	void rebind (MIDI::Port&);
 	bool speed_and_position (float&, nframes_t&);
 
-	bool      locked() const;
-	bool      ok() const;
-	void      handle_locate (const MIDI::byte*);
+	bool locked() const;
+	bool ok() const;
+	void handle_locate (const MIDI::byte*);
 
 	nframes_t resolution() const;
 	bool requires_seekahead () const { return true; }
@@ -72,27 +84,11 @@ class MTC_Slave : public Slave, public sigc::trackable {
 	std::vector<sigc::connection> connections;
 	bool        can_notify_on_unknown_rate;
 
-	struct SafeTime {
-
-
-	    int guard1;
-	    //SMPTE_Time  mtc;
-	    nframes_t   position;
-	    nframes_t   timestamp;
-	    int guard2;
-
-	    SafeTime() {
-		    guard1 = 0;
-		    guard2 = 0;
-		    timestamp = 0;
-	    }
-	};
-
-	SafeTime         current;
+	SafeTime    current;
 	nframes_t   mtc_frame;               /* current time */
 	nframes_t   last_inbound_frame;      /* when we got it; audio clocked */
 
-	float            mtc_speed;
+	float       mtc_speed;
 	nframes_t   first_mtc_frame;
 	nframes_t   first_mtc_time;
 
@@ -108,12 +104,56 @@ class MTC_Slave : public Slave, public sigc::trackable {
 	void read_current (SafeTime *) const;
 };
 
-class ADAT_Slave : public Slave 
+class MIDIClock_Slave : public Slave, public sigc::trackable {
+  public:
+	MIDIClock_Slave (Session&, MIDI::Port&, int ppqn = 24);
+	~MIDIClock_Slave ();
+
+	void rebind (MIDI::Port&);
+	bool speed_and_position (float&, nframes_t&);
+
+	bool locked() const;
+	bool ok() const;
+	bool starting() const { return _starting; }
+
+	nframes_t resolution() const;
+	bool requires_seekahead () const { return true; }
+
+  private:
+	Session&    session;
+	MIDI::Port* port;
+	std::vector<sigc::connection> connections;
+
+	int         ppqn;
+	double      one_ppqn_in_frames;
+
+	SafeTime    current;
+	nframes_t   midi_clock_frame;               /* current time */
+	nframes_t   last_inbound_frame;             /* when we got it; audio clocked */
+
+	float       midi_clock_speed;
+	nframes_t   first_midi_clock_frame;
+	nframes_t   first_midi_clock_time;
+
+	static const int32_t accumulator_size = 128;
+	float   accumulator[accumulator_size];
+	int32_t accumulator_index;
+	bool    have_first_accumulated_speed;
+
+	void reset ();
+	void start (MIDI::Parser& parser);
+	void stop (MIDI::Parser& parser);
+	void update_midi_clock (MIDI::Parser& parser);
+	void read_current (SafeTime *) const;
+	bool _starting;
+};
+
+class ADAT_Slave : public Slave
 {
   public:
 	ADAT_Slave () {}
 	~ADAT_Slave () {}
-	
+
 	bool speed_and_position (float& speed, nframes_t& pos) {
 		speed = 0;
 		pos = 0;
@@ -126,12 +166,12 @@ class ADAT_Slave : public Slave
 	bool requires_seekahead () const { return true; }
 };
 
-class JACK_Slave : public Slave 
+class JACK_Slave : public Slave
 {
   public:
 	JACK_Slave (jack_client_t*);
 	~JACK_Slave ();
-	
+
 	bool speed_and_position (float& speed, nframes_t& pos);
 
 	bool starting() const { return _starting; }
diff --git a/libs/ardour/ardour/types.h b/libs/ardour/ardour/types.h
index 9bfd93cdbf..d94683f427 100644
--- a/libs/ardour/ardour/types.h
+++ b/libs/ardour/ardour/types.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2002 Paul Davis 
+    Copyright (C) 2002 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -41,7 +41,7 @@
 typedef int intptr_t;
 #endif
 
-/* eventually, we'd like everything (including JACK) to 
+/* eventually, we'd like everything (including JACK) to
    move to this. for now, its a dedicated type.
 */
 
@@ -69,7 +69,7 @@ namespace ARDOUR {
 		OverlapNone,      // no overlap
 		OverlapInternal,  // the overlap is 100% with the object
 		OverlapStart,     // overlap covers start, but ends within
-		OverlapEnd,       // overlap begins within and covers end 
+		OverlapEnd,       // overlap begins within and covers end
 		OverlapExternal   // overlap extends to (at least) begin+end
 	};
 
@@ -128,12 +128,12 @@ namespace ARDOUR {
 		Normal,
 		Destructive
 	};
-	
+
 	enum NoteMode {
 		Sustained,
 		Percussive
 	};
-	
+
 	enum ChannelMode {
 		AllChannels = 0, ///< Pass through all channel information unmodified
 		FilterChannels,  ///< Ignore events on certain channels
@@ -144,7 +144,7 @@ namespace ARDOUR {
 		Frames,
 		Beats
 	};
-	
+
 	struct BBT_Time {
 	    uint32_t bars;
 	    uint32_t beats;
@@ -157,12 +157,12 @@ namespace ARDOUR {
 	    }
 
 	    /* we can't define arithmetic operators for BBT_Time, because
-	       the results depend on a TempoMap, but we can define 
+	       the results depend on a TempoMap, but we can define
 	       a useful check on the less-than condition.
 	    */
 
 	    bool operator< (const BBT_Time& other) const {
-		    return bars < other.bars || 
+		    return bars < other.bars ||
 			    (bars == other.bars && beats < other.beats) ||
 			    (bars == other.bars && beats == other.beats && ticks < other.ticks);
 	    }
@@ -170,7 +170,7 @@ namespace ARDOUR {
 	    bool operator== (const BBT_Time& other) const {
 		    return bars == other.bars && beats == other.beats && ticks == other.ticks;
 	    }
-	    
+
 	};
 	enum SmpteFormat {
 		smpte_23976,
@@ -198,7 +198,7 @@ namespace ARDOUR {
 	    SMPTE::Time    smpte;
 	    BBT_Time       bbt;
 
-	    union { 
+	    union {
 		nframes_t frames;
 		double         seconds;
 	    };
@@ -210,10 +210,10 @@ namespace ARDOUR {
 	    nframes_t start;
 	    nframes_t end;
 	    uint32_t id;
-	    
+
 	    AudioRange (nframes_t s, nframes_t e, uint32_t i) : start (s), end (e) , id (i) {}
-	    
-	    nframes_t length() { return end - start + 1; } 
+
+	    nframes_t length() { return end - start + 1; }
 
 	    bool operator== (const AudioRange& other) const {
 		    return start == other.start && end == other.end && id == other.id;
@@ -227,12 +227,12 @@ namespace ARDOUR {
 		    return ARDOUR::coverage (start, end, s, e);
 	    }
 	};
-	
+
 	struct MusicRange {
 	    BBT_Time start;
 	    BBT_Time end;
 	    uint32_t id;
-	    
+
 	    MusicRange (BBT_Time& s, BBT_Time& e, uint32_t i)
 		    : start (s), end (e), id (i) {}
 
@@ -273,7 +273,7 @@ namespace ARDOUR {
 		Lock
 	};
 
-	enum RegionPoint { 
+	enum RegionPoint {
 	    Start,
 	    End,
 	    SyncPoint
@@ -312,7 +312,7 @@ namespace ARDOUR {
 		FullCrossfade,
 		ShortCrossfade
 	};
-	
+
 	enum LayerModel {
 		LaterHigher,
 		MoveAddHigher,
@@ -355,11 +355,11 @@ namespace ARDOUR {
 
 	struct PeakData {
 	    typedef Sample PeakDatum;
-	    
+
 	    PeakDatum min;
 	    PeakDatum max;
 	};
-	
+
 	enum PluginType {
 		AudioUnit,
 		LADSPA,
@@ -370,7 +370,8 @@ namespace ARDOUR {
 	enum SlaveSource {
 		None = 0,
 		MTC,
-		JACK
+		JACK,
+		MIDIClock
 	};
 
 	enum ShuttleBehaviour {
@@ -399,8 +400,8 @@ namespace ARDOUR {
 	    float time_fraction;
 	    float pitch_fraction;
 	    /* SoundTouch */
-	    bool  quick_seek; 
-	    bool  antialias;  
+	    bool  quick_seek;
+	    bool  antialias;
 	    /* RubberBand */
 	    int   opts; // really RubberBandStretcher::Options
 	};
diff --git a/libs/ardour/enums.cc b/libs/ardour/enums.cc
index 71b699396b..0781f8c8e1 100644
--- a/libs/ardour/enums.cc
+++ b/libs/ardour/enums.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2000-2007 Paul Davis 
+    Copyright (C) 2000-2007 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -103,7 +103,7 @@ setup_enum_writer ()
 	REGISTER_ENUM (OverlapEnd);
 	REGISTER_ENUM (OverlapExternal);
 	REGISTER (_OverlapType);
-	
+
 	REGISTER_ENUM (GainAutomation);
 	REGISTER_ENUM (PanAutomation);
 	REGISTER_ENUM (PluginAutomation);
@@ -126,22 +126,22 @@ setup_enum_writer ()
 	REGISTER_BITS (_AutoStyle);
 
 	REGISTER_ENUM (CaptureTime);
-	REGISTER_ENUM (ExistingMaterial);	
+	REGISTER_ENUM (ExistingMaterial);
 	REGISTER (_AlignStyle);
 
 	REGISTER_ENUM (MeterInput);
 	REGISTER_ENUM (MeterPreFader);
-	REGISTER_ENUM (MeterPostFader);	
+	REGISTER_ENUM (MeterPostFader);
 	REGISTER (_MeterPoint);
 
 	REGISTER_ENUM (Normal);
 	REGISTER_ENUM (Destructive);
 	REGISTER (_TrackMode);
-	
+
 	REGISTER_ENUM (Sustained);
 	REGISTER_ENUM (Percussive);
 	REGISTER (_NoteMode);
-	
+
 	REGISTER_ENUM (AllChannels);
 	REGISTER_ENUM (FilterChannels);
 	REGISTER_ENUM (ForceChannel);
@@ -155,7 +155,7 @@ setup_enum_writer ()
 	REGISTER_ENUM (MeterFalloffFaster);
 	REGISTER_ENUM (MeterFalloffFastest);
 	REGISTER (_MeterFalloff);
-	
+
 	REGISTER_ENUM (MeterHoldOff);
 	REGISTER_ENUM (MeterHoldShort);
 	REGISTER_ENUM (MeterHoldMedium);
@@ -163,12 +163,12 @@ setup_enum_writer ()
 	REGISTER (_MeterHold);
 
 	REGISTER_ENUM (Slide);
-	REGISTER_ENUM (Splice);	
+	REGISTER_ENUM (Splice);
 	REGISTER (_EditMode);
 
 	REGISTER_ENUM (Start);
 	REGISTER_ENUM (End);
-	REGISTER_ENUM (SyncPoint);	
+	REGISTER_ENUM (SyncPoint);
 	REGISTER (_RegionPoint);
 
 	REGISTER_ENUM (PreFader);
@@ -197,11 +197,11 @@ setup_enum_writer ()
 
 	REGISTER_ENUM (LaterHigher);
 	REGISTER_ENUM (MoveAddHigher);
-	REGISTER_ENUM (AddHigher);	
+	REGISTER_ENUM (AddHigher);
 	REGISTER (_LayerModel);
 
 	REGISTER_ENUM (InverseMute);
-	REGISTER_ENUM (SoloBus);	
+	REGISTER_ENUM (SoloBus);
 	REGISTER (_SoloModel);
 
 	REGISTER_ENUM (AutoConnectPhysical);
@@ -219,7 +219,7 @@ setup_enum_writer ()
 	REGISTER_ENUM (CAF);
 	REGISTER_ENUM (AIFF);
 	REGISTER_ENUM (iXML);
-	REGISTER_ENUM (RF64);	
+	REGISTER_ENUM (RF64);
 	REGISTER (_HeaderFormat);
 
 	REGISTER_ENUM (AudioUnit);
@@ -229,15 +229,16 @@ setup_enum_writer ()
 
 	REGISTER_ENUM (None);
 	REGISTER_ENUM (MTC);
-	REGISTER_ENUM (JACK);	
+	REGISTER_ENUM (JACK);
+	REGISTER_ENUM (MIDIClock);
 	REGISTER (_SlaveSource);
 
 	REGISTER_ENUM (Sprung);
-	REGISTER_ENUM (Wheel);	
+	REGISTER_ENUM (Wheel);
 	REGISTER (_ShuttleBehaviour);
 
 	REGISTER_ENUM (Percentage);
-	REGISTER_ENUM (Semitones);	
+	REGISTER_ENUM (Semitones);
 	REGISTER (_ShuttleUnits);
 
 	REGISTER_CLASS_ENUM (Session, Disabled);
@@ -379,10 +380,10 @@ setup_enum_writer ()
 	REGISTER_CLASS_ENUM (Track, Frozen);
 	REGISTER_CLASS_ENUM (Track, UnFrozen);
 	REGISTER (_Track_FreezeState);
-	
+
 	REGISTER_CLASS_ENUM (AutomationList, Discrete);
 	REGISTER_CLASS_ENUM (AutomationList, Linear);
 	REGISTER_CLASS_ENUM (AutomationList, Curved);
 	REGISTER (_AutomationList_InterpolationStyle);
-	
+
 }
diff --git a/libs/ardour/globals.cc b/libs/ardour/globals.cc
index 02c4a5ced6..1397a7d959 100644
--- a/libs/ardour/globals.cc
+++ b/libs/ardour/globals.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2000 Paul Davis 
+    Copyright (C) 2000 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -73,7 +73,7 @@
 #if defined (__APPLE__)
        #include <Carbon/Carbon.h> // For Gestalt
 #endif
-       
+
 #include "i18n.h"
 
 ARDOUR::Configuration* ARDOUR::Config = 0;
@@ -91,6 +91,7 @@ using namespace PBD;
 MIDI::Port *default_mmc_port = 0;
 MIDI::Port *default_mtc_port = 0;
 MIDI::Port *default_midi_port = 0;
+MIDI::Port *default_midi_clock_port = 0;
 
 Change ARDOUR::StartChanged = ARDOUR::new_change ();
 Change ARDOUR::LengthChanged = ARDOUR::new_change ();
@@ -111,11 +112,11 @@ static int
 setup_osc ()
 {
 	/* no real cost to creating this object, and it avoids
-	   conditionals anywhere that uses it 
+	   conditionals anywhere that uses it
 	*/
-	
+
 	osc = new OSC (Config->get_osc_port());
-	
+
 	if (Config->get_use_osc ()) {
 		BootMessage (_("Starting OSC"));
 		return osc->start ();
@@ -125,7 +126,7 @@ setup_osc ()
 }
 #endif
 
-int 
+int
 setup_midi ()
 {
 	if (Config->midi_ports.size() == 0) {
@@ -150,16 +151,20 @@ setup_midi ()
 
 		if (Config->get_mmc_port_name() != N_("default")) {
 			default_mmc_port =  MIDI::Manager::instance()->port (Config->get_mmc_port_name());
-		} 
+		}
 
 		if (Config->get_mtc_port_name() != N_("default")) {
 			default_mtc_port =  MIDI::Manager::instance()->port (Config->get_mtc_port_name());
-		} 
+		}
 
 		if (Config->get_midi_port_name() != N_("default")) {
 			default_midi_port =  MIDI::Manager::instance()->port (Config->get_midi_port_name());
-		} 
-		
+		}
+
+		if (Config->get_midi_clock_port_name() != N_("default")) {
+			default_midi_port =  MIDI::Manager::instance()->port (Config->get_midi_clock_port_name());
+		}
+
 		/* If that didn't work, just use the first listed port */
 
 		if (default_mmc_port == 0) {
@@ -173,7 +178,11 @@ setup_midi ()
 		if (default_midi_port == 0) {
 			default_midi_port = first;
 		}
-		
+
+		if (default_midi_clock_port == 0) {
+			default_midi_clock_port = first;
+		}
+
 	} else if (ports.size() == 1) {
 
 		first = ports.begin()->second;
@@ -183,21 +192,27 @@ setup_midi ()
 		default_mmc_port = first;
 		default_mtc_port = default_mmc_port;
 		default_midi_port = default_mmc_port;
+		default_midi_clock_port = default_mmc_port;
 	}
 
 	if (default_mmc_port == 0) {
-		warning << string_compose (_("No MMC control (MIDI port \"%1\" not available)"), Config->get_mmc_port_name()) 
+		warning << string_compose (_("No MMC control (MIDI port \"%1\" not available)"), Config->get_mmc_port_name())
 			<< endmsg;
 		return 0;
-	} 
+	}
 
 	if (default_mtc_port == 0) {
-		warning << string_compose (_("No MTC support (MIDI port \"%1\" not available)"), Config->get_mtc_port_name()) 
+		warning << string_compose (_("No MTC support (MIDI port \"%1\" not available)"), Config->get_mtc_port_name())
 			<< endmsg;
 	}
 
 	if (default_midi_port == 0) {
-		warning << string_compose (_("No MIDI parameter support (MIDI port \"%1\" not available)"), Config->get_midi_port_name()) 
+		warning << string_compose (_("No MIDI parameter support (MIDI port \"%1\" not available)"), Config->get_midi_port_name())
+			<< endmsg;
+	}
+
+	if (default_midi_clock_port == 0) {
+		warning << string_compose (_("No MIDI Clock support (MIDI port \"%1\" not available)"), Config->get_midi_clock_port_name())
 			<< endmsg;
 	}
 
@@ -331,7 +346,7 @@ ARDOUR::init (bool use_vst, bool try_optimization)
 		return -1;
 	}
 #endif
-	
+
 	/* Make VAMP look in our library ahead of anything else */
 
 	char *p = getenv ("VAMP_PATH");
@@ -339,7 +354,7 @@ ARDOUR::init (bool use_vst, bool try_optimization)
 	if (p) {
 		vamppath += ':';
 		vamppath += p;
-	} 
+	}
 	setenv ("VAMP_PATH", vamppath.c_str(), 1);
 
 
@@ -350,7 +365,7 @@ ARDOUR::init (bool use_vst, bool try_optimization)
 
 	/* singleton - first object is "it" */
 	new PluginManager ();
-	
+
 	/* singleton - first object is "it" */
 	new ControlProtocolManager ();
 	ControlProtocolManager::instance().discover_control_protocols ();
@@ -359,7 +374,7 @@ ARDOUR::init (bool use_vst, bool try_optimization)
 	if ((node = Config->control_protocol_state()) != 0) {
 		ControlProtocolManager::instance().set_state (*node);
 	}
-	
+
 	BoundsChanged = Change (StartChanged|PositionChanged|LengthChanged);
 
 	return 0;
@@ -430,7 +445,7 @@ ARDOUR::find_bindings_files (map<string,string>& files)
 	if (found.empty()) {
 		return;
 	}
-	
+
 	for (vector<sys::path>::iterator x = found.begin(); x != found.end(); ++x) {
 		sys::path path = *x;
 		pair<string,string> namepath;
@@ -445,7 +460,7 @@ ARDOUR::LocaleGuard::LocaleGuard (const char* str)
 	old = strdup (setlocale (LC_NUMERIC, NULL));
 	if (strcmp (old, str)) {
 		setlocale (LC_NUMERIC, str);
-	} 
+	}
 }
 
 ARDOUR::LocaleGuard::~LocaleGuard ()
@@ -472,7 +487,7 @@ ARDOUR::setup_fpu ()
 	/* XXX use real code to determine if the processor supports
 	   DenormalsAreZero and FlushToZero
 	*/
-	
+
 	if (!fpu.has_flush_to_zero() && !fpu.has_denormals_are_zero()) {
 		return;
 	}
@@ -496,7 +511,7 @@ ARDOUR::setup_fpu ()
 			MXCSR |= 0x8000;
 		}
 		break;
-		
+
 	case DenormalFTZDAZ:
 		if (fpu.has_flush_to_zero()) {
 			if (fpu.has_denormals_are_zero()) {
@@ -514,7 +529,7 @@ ARDOUR::setup_fpu ()
 }
 
 ARDOUR::OverlapType
-ARDOUR::coverage (nframes_t sa, nframes_t ea, 
+ARDOUR::coverage (nframes_t sa, nframes_t ea,
 		  nframes_t sb, nframes_t eb)
 {
 	/* OverlapType returned reflects how the second (B)
@@ -539,7 +554,7 @@ ARDOUR::coverage (nframes_t sa, nframes_t ea,
 	        |-----------------|   B
 
 
-             "B is internal to A"		
+             "B is internal to A"
 
 	*/
 #ifdef OLD_COVERAGE
@@ -555,7 +570,7 @@ ARDOUR::coverage (nframes_t sa, nframes_t ea,
 	   ----|                      B
            -----------------------|   B
 	   --|                        B
-	   
+
 	     "B overlaps the start of A"
 
 	*/
@@ -563,13 +578,13 @@ ARDOUR::coverage (nframes_t sa, nframes_t ea,
 	if ((eb >= sa) && (eb <= ea)) {
 		return OverlapStart;
 	}
-	/* 
+	/*
 	     |---------------------|  A
                    |----------------- B
- 	     |----------------------- B	   
+ 	     |----------------------- B
                                    |- B
 
-            "B overlaps the end of A"				   
+            "B overlaps the end of A"
 
 	*/
 	if ((sb > sa) && (sb <= ea)) {
@@ -577,7 +592,7 @@ ARDOUR::coverage (nframes_t sa, nframes_t ea,
 	}
 	/*
 	     |--------------------|     A
-	   --------------------------  B   
+	   --------------------------  B
 	     |-----------------------  B
 	    ----------------------|    B
              |--------------------|    B
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index ff269cc931..1124b8960f 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 1999-2004 Paul Davis 
+    Copyright (C) 1999-2004 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -131,11 +131,12 @@ Session::Session (AudioEngine &eng,
 	  _mmc_port (default_mmc_port),
 	  _mtc_port (default_mtc_port),
 	  _midi_port (default_midi_port),
+	  _midi_clock_port (default_midi_clock_port),
 	  _session_dir (new SessionDirectory(fullpath)),
 	  pending_events (2048),
 	  post_transport_work((PostTransportWork)0),
 	  _send_smpte_update (false),
-	  midi_requests (128), 
+	  midi_requests (128),
 	  diskstreams (new DiskstreamList),
 	  routes (new RouteList),
 	  auditioner ((Auditioner*) 0),
@@ -148,7 +149,7 @@ Session::Session (AudioEngine &eng,
 	if (!eng.connected()) {
 		throw failed_constructor();
 	}
-	
+
 	cerr << "Loading session " << fullpath << " using snapshot " << snapshot_name << " (1)" << endl;
 
 	n_physical_outputs = _engine.n_physical_outputs();
@@ -164,14 +165,14 @@ Session::Session (AudioEngine &eng,
 			throw failed_constructor ();
 		}
 	}
-	
+
 	if (second_stage_init (new_session)) {
 		destroy ();
 		throw failed_constructor ();
 	}
-	
+
 	store_recent_sessions(_name, _path);
-	
+
 	bool was_dirty = dirty();
 
 	_state_of_the_state = StateOfTheState (_state_of_the_state & ~Dirty);
@@ -201,6 +202,7 @@ Session::Session (AudioEngine &eng,
 	  _mmc_port (default_mmc_port),
 	  _mtc_port (default_mtc_port),
 	  _midi_port (default_midi_port),
+	  _midi_clock_port (default_midi_clock_port),
 	  _session_dir ( new SessionDirectory(fullpath)),
 	  pending_events (2048),
 	  post_transport_work((PostTransportWork)0),
@@ -244,31 +246,31 @@ Session::Session (AudioEngine &eng,
 
 	{
 		/* set up Master Out and Control Out if necessary */
-		
+
 		RouteList rl;
 		int control_id = 1;
-		
+
 		if (control_out_channels) {
 			shared_ptr<Route> r (new Route (*this, _("monitor"), -1, control_out_channels, -1, control_out_channels, Route::ControlOut));
 			r->set_remote_control_id (control_id++);
-			
+
 			rl.push_back (r);
 		}
-		
+
 		if (master_out_channels) {
 			shared_ptr<Route> r (new Route (*this, _("master"), -1, master_out_channels, -1, master_out_channels, Route::MasterOut));
 			r->set_remote_control_id (control_id);
-			 
+
 			rl.push_back (r);
 		} else {
 			/* prohibit auto-connect to master, because there isn't one */
 			output_ac = AutoConnectOption (output_ac & ~AutoConnectMaster);
 		}
-		
+
 		if (!rl.empty()) {
 			add_routes (rl, false);
 		}
-		
+
 	}
 
 	Config->set_input_auto_connect (input_ac);
@@ -278,9 +280,9 @@ Session::Session (AudioEngine &eng,
 		destroy ();
 		throw failed_constructor ();
 	}
-	
+
 	store_recent_sessions (_name, _path);
-	
+
 	_state_of_the_state = StateOfTheState (_state_of_the_state & ~Dirty);
 
 	Config->ParameterChanged.connect (mem_fun (*this, &Session::config_changed));
@@ -305,7 +307,7 @@ Session::destroy ()
 	_engine.remove_session ();
 
 	GoingAway (); /* EMIT SIGNAL */
-	
+
 	/* do this */
 
 	notify_callbacks ();
@@ -315,14 +317,14 @@ Session::destroy ()
 	_history.clear ();
 
 	/* clear state tree so that no references to objects are held any more */
-	
+
 	if (state_tree) {
 		delete state_tree;
 	}
 
 	terminate_butler_thread ();
 	//terminate_midi_thread ();
-	
+
 	if (click_data && click_data != default_click) {
 		delete [] click_data;
 	}
@@ -338,9 +340,9 @@ Session::destroy ()
 	delete _mix_buffers;
 
 	AudioDiskstream::free_working_buffers();
-	
+
 	Route::SyncOrderKeys.clear();
-	
+
 #undef TRACK_DESTRUCTION
 #ifdef TRACK_DESTRUCTION
 	cerr << "delete named selections\n";
@@ -365,10 +367,10 @@ Session::destroy ()
 		++tmp;
 
 		(*i)->drop_references ();
-		
+
 		i = tmp;
 	}
-	
+
 	for (PlaylistList::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ) {
 		PlaylistList::iterator tmp;
 
@@ -376,17 +378,17 @@ Session::destroy ()
 		++tmp;
 
 		(*i)->drop_references ();
-		
+
 		i = tmp;
 	}
-	
+
 	playlists.clear ();
 	unused_playlists.clear ();
 
 #ifdef TRACK_DESTRUCTION
 	cerr << "delete regions\n";
 #endif /* TRACK_DESTRUCTION */
-	
+
 	for (RegionList::iterator i = regions.begin(); i != regions.end(); ) {
 		RegionList::iterator tmp;
 
@@ -436,13 +438,13 @@ Session::destroy ()
 
 		tmp = i;
 		++tmp;
-		
+
 		i->second->drop_references ();
-		
+
 		i = tmp;
 	}
 	sources.clear ();
-	
+
 #ifdef TRACK_DESTRUCTION
 	cerr << "delete mix groups\n";
 #endif /* TRACK_DESTRUCTION */
@@ -462,7 +464,7 @@ Session::destroy ()
 #endif /* TRACK_DESTRUCTION */
 	for (list<RouteGroup *>::iterator i = edit_groups.begin(); i != edit_groups.end(); ) {
 		list<RouteGroup*>::iterator tmp;
-		
+
 		tmp = i;
 		++tmp;
 
@@ -470,7 +472,7 @@ Session::destroy ()
 
 		i = tmp;
 	}
-	
+
 	if (butler_mixdown_buffer) {
 		delete [] butler_mixdown_buffer;
 	}
@@ -497,7 +499,7 @@ Session::set_worst_io_latencies ()
 	}
 
 	boost::shared_ptr<RouteList> r = routes.reader ();
-	
+
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 		_worst_output_latency = max (_worst_output_latency, (*i)->output_latency());
 		_worst_input_latency = max (_worst_input_latency, (*i)->input_latency());
@@ -536,15 +538,15 @@ Session::when_engine_running ()
 
 	try {
 		XMLNode* child = 0;
-		
+
 		_click_io.reset (new ClickIO (*this, "click", 0, 0, -1, -1));
 
 		if (state_tree && (child = find_named_node (*state_tree->root(), "Click")) != 0) {
 
 			/* existing state for Click */
-			
+
 			if (_click_io->set_state (*child->children().front()) == 0) {
-				
+
 				_clicking = Config->get_clicking ();
 
 			} else {
@@ -554,7 +556,7 @@ Session::when_engine_running ()
 			}
 
 		} else {
-			
+
 			/* default state for Click */
 
 			first_physical_output = _engine.get_nth_physical_output (DataType::AUDIO, 0);
@@ -642,24 +644,24 @@ Session::when_engine_running ()
 	if (_master_out) {
 
 		/* create master/control ports */
-		
+
 		if (_master_out) {
 			uint32_t n;
 
 			/* force the master to ignore any later call to this */
-			
+
 			if (_master_out->pending_state_node) {
 				_master_out->ports_became_legal();
 			}
 
 			/* no panner resets till we are through */
-			
+
 			_master_out->defer_pan_reset ();
-			
+
 			while (_master_out->n_inputs().n_audio()
 					< _master_out->input_maximum().n_audio()) {
 				if (_master_out->add_input_port ("", this, DataType::AUDIO)) {
-					error << _("cannot setup master inputs") 
+					error << _("cannot setup master inputs")
 					      << endmsg;
 					break;
 				}
@@ -676,7 +678,7 @@ Session::when_engine_running ()
 			}
 
 			_master_out->allow_pan_reset ();
-			
+
 		}
 
  		shared_ptr<AutoBundle> c (new AutoBundle (_("Master Out"), true));
@@ -686,8 +688,8 @@ Session::when_engine_running ()
  			c->set_port (n, _master_out->input(n)->name());
  		}
  		add_bundle (c);
-	} 
-	
+	}
+
 	BootMessage (_("Setup signal flow and plugins"));
 
 	hookup_io ();
@@ -697,7 +699,7 @@ Session::when_engine_running ()
 	BootMessage (_("Catch up with send/insert state"));
 
 	insert_cnt = 0;
-	
+
 	for (list<PortInsert*>::iterator i = _port_inserts.begin(); i != _port_inserts.end(); ++i) {
 		uint32_t id;
 
@@ -712,7 +714,7 @@ Session::when_engine_running ()
 
 	for (list<Send*>::iterator i = _sends.begin(); i != _sends.end(); ++i) {
 		uint32_t id;
-		
+
 		if (sscanf ((*i)->name().c_str(), "%*s %u", &id) == 1) {
 			if (id > send_cnt) {
 				send_cnt = id;
@@ -720,7 +722,7 @@ Session::when_engine_running ()
 		}
 	}
 
-	
+
 	_state_of_the_state = StateOfTheState (_state_of_the_state & ~(CannotSave|Dirty));
 
 	/* hook us up to the engine */
@@ -736,7 +738,7 @@ Session::when_engine_running ()
 
 	osc->set_session (*this);
 #endif
-    
+
 }
 
 void
@@ -750,16 +752,16 @@ Session::hookup_io ()
 
 
 	if (auditioner == 0) {
-		
+
 		/* we delay creating the auditioner till now because
 		   it makes its own connections to ports.
 		   the engine has to be running for this to work.
 		*/
-		
+
 		try {
 			auditioner.reset (new Auditioner (*this));
 		}
-		
+
 		catch (failed_constructor& err) {
 			warning << _("cannot create Auditioner: no auditioning of regions possible") << endmsg;
 		}
@@ -797,7 +799,7 @@ Session::hookup_io ()
 			cports.push_back (_control_out->input(n)->name());
 		}
 
-		boost::shared_ptr<RouteList> r = routes.reader ();		
+		boost::shared_ptr<RouteList> r = routes.reader ();
 
 		for (RouteList::iterator x = r->begin(); x != r->end(); ++x) {
 			(*x)->set_control_outs (cports);
@@ -808,7 +810,7 @@ Session::hookup_io ()
 	if (_bundle_xml_node) {
 		load_bundles (*_bundle_xml_node);
 		delete _bundle_xml_node;
-	}	
+	}
 
 	/* Tell all IO objects to connect themselves together */
 
@@ -839,10 +841,10 @@ Session::hookup_io ()
 void
 Session::playlist_length_changed ()
 {
-	/* we can't just increase end_location->end() if pl->get_maximum_extent() 
+	/* we can't just increase end_location->end() if pl->get_maximum_extent()
 	   if larger. if the playlist used to be the longest playlist,
 	   and its now shorter, we have to decrease end_location->end(). hence,
-	   we have to iterate over all diskstreams and check the 
+	   we have to iterate over all diskstreams and check the
 	   playlists currently in use.
 	*/
 	find_current_end ();
@@ -856,7 +858,7 @@ Session::diskstream_playlist_changed (boost::shared_ptr<Diskstream> dstream)
 	if ((playlist = dstream->playlist()) != 0) {
 		playlist->LengthChanged.connect (mem_fun (this, &Session::playlist_length_changed));
 	}
-	
+
 	/* see comment in playlist_length_changed () */
 	find_current_end ();
 }
@@ -909,7 +911,7 @@ Session::auto_punch_start_changed (Location* location)
 		/* capture start has been changed, so save new pending state */
 		save_state ("", true);
 	}
-}	
+}
 
 void
 Session::auto_punch_end_changed (Location* location)
@@ -917,7 +919,7 @@ Session::auto_punch_end_changed (Location* location)
 	nframes_t when_to_stop = location->end();
 	// when_to_stop += _worst_output_latency + _worst_input_latency;
 	replace_event (Event::PunchOut, when_to_stop);
-}	
+}
 
 void
 Session::auto_punch_changed (Location* location)
@@ -927,7 +929,7 @@ Session::auto_punch_changed (Location* location)
 	replace_event (Event::PunchIn, location->start());
 	//when_to_stop += _worst_output_latency + _worst_input_latency;
 	replace_event (Event::PunchOut, when_to_stop);
-}	
+}
 
 void
 Session::auto_loop_changed (Location* location)
@@ -941,12 +943,12 @@ Session::auto_loop_changed (Location* location)
 		if (_transport_frame > location->end()) {
 			// relocate to beginning of loop
 			clear_events (Event::LocateRoll);
-			
+
 			request_locate (location->start(), true);
 
 		}
 		else if (Config->get_seamless_loop() && !loop_changing) {
-			
+
 			// schedule a locate-roll to refill the diskstreams at the
 			// previous loop end
 			loop_changing = true;
@@ -958,7 +960,7 @@ Session::auto_loop_changed (Location* location)
 			}
 
 		}
-	}	
+	}
 
 	last_loopend = location->end();
 }
@@ -983,7 +985,7 @@ Session::set_auto_punch_location (Location* location)
 	if (location == 0) {
 		return;
 	}
-	
+
 	if (location->end() <= location->start()) {
 		error << _("Session: you can't use that location for auto punch (start <= end)") << endmsg;
 		return;
@@ -992,7 +994,7 @@ Session::set_auto_punch_location (Location* location)
 	auto_punch_start_changed_connection.disconnect();
 	auto_punch_end_changed_connection.disconnect();
 	auto_punch_changed_connection.disconnect();
-		
+
 	auto_punch_start_changed_connection = location->start_changed.connect (mem_fun (this, &Session::auto_punch_start_changed));
 	auto_punch_end_changed_connection = location->end_changed.connect (mem_fun (this, &Session::auto_punch_end_changed));
 	auto_punch_changed_connection = location->changed.connect (mem_fun (this, &Session::auto_punch_changed));
@@ -1018,7 +1020,7 @@ Session::set_auto_loop_location (Location* location)
 		remove_event (existing->end(), Event::AutoLoop);
 		auto_loop_location_changed (0);
 	}
-	
+
 	set_dirty();
 
 	if (location == 0) {
@@ -1031,11 +1033,11 @@ Session::set_auto_loop_location (Location* location)
 	}
 
 	last_loopend = location->end();
-	
+
 	auto_loop_start_changed_connection.disconnect();
 	auto_loop_end_changed_connection.disconnect();
 	auto_loop_changed_connection.disconnect();
-	
+
 	auto_loop_start_changed_connection = location->start_changed.connect (mem_fun (this, &Session::auto_loop_changed));
 	auto_loop_end_changed_connection = location->end_changed.connect (mem_fun (this, &Session::auto_loop_changed));
 	auto_loop_changed_connection = location->changed.connect (mem_fun (this, &Session::auto_loop_changed));
@@ -1083,7 +1085,7 @@ Session::handle_locations_changed (Locations::LocationList& locations)
 			set_auto_loop_location (location);
 			set_loop = true;
 		}
-		
+
 	}
 
 	if (!set_loop) {
@@ -1094,7 +1096,7 @@ Session::handle_locations_changed (Locations::LocationList& locations)
 	}
 
 	set_dirty();
-}						     
+}
 
 void
 Session::enable_record ()
@@ -1109,7 +1111,7 @@ Session::enable_record ()
 			boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 			for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 				if ((*i)->record_enabled ()) {
-					(*i)->monitor_input (true);   
+					(*i)->monitor_input (true);
 				}
 			}
 		}
@@ -1141,14 +1143,14 @@ Session::disable_record (bool rt_context, bool force)
 
 		if (Config->get_monitoring_model() == HardwareMonitoring && Config->get_auto_input()) {
 			boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
-			
+
 			for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 				if ((*i)->record_enabled ()) {
-					(*i)->monitor_input (false);   
+					(*i)->monitor_input (false);
 				}
 			}
 		}
-		
+
 		RecordStateChanged (); /* emit signal */
 
 		if (!rt_context) {
@@ -1166,11 +1168,11 @@ Session::step_back_from_record ()
 
 		if (Config->get_monitoring_model() == HardwareMonitoring && Config->get_auto_input()) {
 			boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
-			
+
 			for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 				if ((*i)->record_enabled ()) {
 					//cerr << "switching from input" << __FILE__ << __LINE__ << endl << endl;
-					(*i)->monitor_input (false);   
+					(*i)->monitor_input (false);
 				}
 			}
 		}
@@ -1191,7 +1193,7 @@ Session::maybe_enable_record ()
 	if (_transport_speed) {
 		if (!Config->get_punch_in()) {
 			enable_record ();
-		} 
+		}
 	} else {
 		deliver_mmc (MIDI::MachineControl::cmdRecordPause, _transport_frame);
 		RecordStateChanged (); /* EMIT SIGNAL */
@@ -1208,7 +1210,7 @@ Session::audible_frame () const
 	nframes_t tf;
 
 	/* the first of these two possible settings for "offset"
-	   mean that the audible frame is stationary until 
+	   mean that the audible frame is stationary until
 	   audio emerges from the latency compensation
 	   "pseudo-pipeline".
 
@@ -1221,7 +1223,7 @@ Session::audible_frame () const
 
 	if (offset > current_block_size) {
 		offset -= current_block_size;
-	} else { 
+	} else {
 		/* XXX is this correct? if we have no external
 		   physical connections and everything is internal
 		   then surely this is zero? still, how
@@ -1251,7 +1253,7 @@ Session::audible_frame () const
 		/* MOVING */
 
 		/* take latency into account */
-		
+
 		ret -= offset;
 	}
 
@@ -1262,7 +1264,7 @@ void
 Session::set_frame_rate (nframes_t frames_per_second)
 {
 	/** \fn void Session::set_frame_size(nframes_t)
-		the AudioEngine object that calls this guarantees 
+		the AudioEngine object that calls this guarantees
 		that it will not be called while we are also in
 		::process(). Its fine to do things that block
 		here.
@@ -1275,7 +1277,7 @@ Session::set_frame_rate (nframes_t frames_per_second)
 	Automatable::set_automation_interval ((jack_nframes_t) ceil ((double) frames_per_second * (0.001 * Config->get_automation_interval())));
 
 	clear_clicks ();
-	
+
 	// XXX we need some equivalent to this, somehow
 	// SndFileSource::setup_standard_crossfades (frames_per_second);
 
@@ -1287,14 +1289,14 @@ Session::set_frame_rate (nframes_t frames_per_second)
 void
 Session::set_block_size (nframes_t nframes)
 {
-	/* the AudioEngine guarantees 
+	/* the AudioEngine guarantees
 	   that it will not be called while we are also in
 	   ::process(). It is therefore fine to do things that block
 	   here.
 	*/
 
-	{ 
-			
+	{
+
 		current_block_size = nframes;
 
 		ensure_buffers(_scratch_buffers->available());
@@ -1311,7 +1313,7 @@ Session::set_block_size (nframes_t nframes)
 		for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 			(*i)->set_block_size (nframes);
 		}
-		
+
 		boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 		for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 			(*i)->set_block_size (nframes);
@@ -1326,18 +1328,18 @@ Session::set_default_fade (float steepness, float fade_msecs)
 {
 #if 0
 	nframes_t fade_frames;
-	
+
 	/* Don't allow fade of less 1 frame */
-	
+
 	if (fade_msecs < (1000.0 * (1.0/_current_frame_rate))) {
 
 		fade_msecs = 0;
 		fade_frames = 0;
 
 	} else {
-		
+
 		fade_frames = (nframes_t) floor (fade_msecs * _current_frame_rate * 0.001);
-		
+
 	}
 
 	default_fade_msecs = fade_msecs;
@@ -1352,7 +1354,7 @@ Session::set_default_fade (float steepness, float fade_msecs)
 	set_dirty();
 
 	/* XXX have to do this at some point */
-	/* foreach region using default fade, reset, then 
+	/* foreach region using default fade, reset, then
 	   refill_all_diskstream_buffers ();
 	*/
 #endif
@@ -1388,7 +1390,7 @@ trace_terminal (shared_ptr<Route> r1, shared_ptr<Route> rbase)
 	if ((r1->fed_by.find (rbase) != r1->fed_by.end()) && (rbase->fed_by.find (r1) != rbase->fed_by.end())) {
 		info << string_compose(_("feedback loop setup between %1 and %2"), r1->name(), rbase->name()) << endmsg;
 		return;
-	} 
+	}
 
 	/* make a copy of the existing list of routes that feed r1 */
 
@@ -1452,45 +1454,45 @@ void
 Session::resort_routes_using (shared_ptr<RouteList> r)
 {
 	RouteList::iterator i, j;
-	
+
 	for (i = r->begin(); i != r->end(); ++i) {
-		
+
 		(*i)->fed_by.clear ();
-		
+
 		for (j = r->begin(); j != r->end(); ++j) {
-			
+
 			/* although routes can feed themselves, it will
 			   cause an endless recursive descent if we
 			   detect it. so don't bother checking for
 			   self-feeding.
 			*/
-			
+
 			if (*j == *i) {
 				continue;
 			}
-			
+
 			if ((*j)->feeds (*i)) {
 				(*i)->fed_by.insert (*j);
-			} 
+			}
 		}
 	}
-	
+
 	for (i = r->begin(); i != r->end(); ++i) {
 		trace_terminal (*i, *i);
 	}
-	
+
 	RouteSorter cmp;
 	r->sort (cmp);
-	
+
 #if 0
 	cerr << "finished route resort\n";
-	
+
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 		cerr << " " << (*i)->name() << " signal order = " << (*i)->order_key ("signal") << endl;
 	}
 	cerr << endl;
 #endif
-	
+
 }
 
 list<boost::shared_ptr<MidiTrack> >
@@ -1505,7 +1507,7 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
 	//uint32_t control_id;
 
 	// FIXME: need physical I/O and autoconnect stuff for MIDI
-	
+
 	/* count existing midi tracks */
 
 	{
@@ -1539,7 +1541,7 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
 		   save, close,restart,add new route - first named route is now
 		   Audio2)
 		*/
-		
+
 
 		do {
 			++track_id;
@@ -1549,7 +1551,7 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
 			if (route_by_name (track_name) == 0) {
 				break;
 			}
-			
+
 		} while (track_id < (UINT_MAX-1));
 
 		/*
@@ -1558,7 +1560,7 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
 		} else {
 			nphysical_in = 0;
 		}
-		
+
 		if (Config->get_output_auto_connect() & AutoConnectPhysical) {
 			nphysical_out = min (n_physical_outputs, (uint32_t) physinputs.size());
 		} else {
@@ -1567,10 +1569,10 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
 		*/
 
 		shared_ptr<MidiTrack> track;
-		
+
 		try {
 			track = boost::shared_ptr<MidiTrack>((new MidiTrack (*this, track_name, Route::Flag (0), mode)));
-			
+
 			if (track->ensure_io (ChanCount(DataType::MIDI, 1), ChanCount(DataType::AUDIO, 1), false, this)) {
 				error << "cannot configure 1 in/1 out configuration for new midi track" << endmsg;
 				goto failed;
@@ -1579,23 +1581,23 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
 			/*
 			if (nphysical_in) {
 				for (uint32_t x = 0; x < track->n_inputs().n_midi() && x < nphysical_in; ++x) {
-					
+
 					port = "";
-					
+
 					if (Config->get_input_auto_connect() & AutoConnectPhysical) {
 						port = physinputs[(channels_used+x)%nphysical_in];
-					} 
-					
+					}
+
 					if (port.length() && track->connect_input (track->input (x), port, this)) {
 						break;
 					}
 				}
 			}
-			
+
 			for (uint32_t x = 0; x < track->n_outputs().n_midi(); ++x) {
-				
+
 				port = "";
-				
+
 				if (nphysical_out && (Config->get_output_auto_connect() & AutoConnectPhysical)) {
 					port = physoutputs[(channels_used+x)%nphysical_out];
 				} else if (Config->get_output_auto_connect() & AutoConnectMaster) {
@@ -1603,18 +1605,18 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
 						port = _master_out->input (x%_master_out->n_inputs().n_midi())->name();
 					}
 				}
-				
+
 				if (port.length() && track->connect_output (track->output (x), port, this)) {
 					break;
 				}
 			}
-			
+
 			channels_used += track->n_inputs ().n_midi();
 
 			*/
 
 			track->midi_diskstream()->non_realtime_input_change();
-			
+
 			track->DiskstreamChanged.connect (mem_fun (this, &Session::resort_routes));
 			//track->set_remote_control_id (control_id);
 
@@ -1629,7 +1631,7 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
 				/* we need to get rid of this, since the track failed to be created */
 				/* XXX arguably, AudioTrack::AudioTrack should not do the Session::add_diskstream() */
 
-				{ 
+				{
 					RCUWriter<DiskstreamList> writer (diskstreams);
 					boost::shared_ptr<DiskstreamList> ds = writer.get_copy();
 					ds->remove (track->midi_diskstream());
@@ -1647,7 +1649,7 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
 				/* we need to get rid of this, since the track failed to be created */
 				/* XXX arguably, MidiTrack::MidiTrack should not do the Session::add_diskstream() */
 
-				{ 
+				{
 					RCUWriter<DiskstreamList> writer (diskstreams);
 					boost::shared_ptr<DiskstreamList> ds = writer.get_copy();
 					ds->remove (track->midi_diskstream());
@@ -1712,7 +1714,7 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
 		   save, close,restart,add new route - first named route is now
 		   Audio2)
 		*/
-		
+
 
 		do {
 			++track_id;
@@ -1722,7 +1724,7 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
 			if (route_by_name (track_name) == 0) {
 				break;
 			}
-			
+
 		} while (track_id < (UINT_MAX-1));
 
 		if (Config->get_input_auto_connect() & AutoConnectPhysical) {
@@ -1730,7 +1732,7 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
 		} else {
 			nphysical_in = 0;
 		}
-		
+
 		if (Config->get_output_auto_connect() & AutoConnectPhysical) {
 			nphysical_out = min (n_physical_outputs, (uint32_t) physinputs.size());
 		} else {
@@ -1738,10 +1740,10 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
 		}
 
 		shared_ptr<AudioTrack> track;
-		
+
 		try {
 			track = boost::shared_ptr<AudioTrack>((new AudioTrack (*this, track_name, Route::Flag (0), mode)));
-			
+
 			if (track->ensure_io (ChanCount(DataType::AUDIO, input_channels), ChanCount(DataType::AUDIO, output_channels), false, this)) {
 				error << string_compose (_("cannot configure %1 in/%2 out configuration for new audio track"),
 							 input_channels, output_channels)
@@ -1751,23 +1753,23 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
 
 			if (nphysical_in) {
 				for (uint32_t x = 0; x < track->n_inputs().n_audio() && x < nphysical_in; ++x) {
-					
+
 					port = "";
-					
+
 					if (Config->get_input_auto_connect() & AutoConnectPhysical) {
 						port = physinputs[(channels_used+x)%nphysical_in];
-					} 
-					
+					}
+
 					if (port.length() && track->connect_input (track->input (x), port, this)) {
 						break;
 					}
 				}
 			}
-			
+
 			for (uint32_t x = 0; x < track->n_outputs().n_midi(); ++x) {
-				
+
 				port = "";
-				
+
 				if (nphysical_out && (Config->get_output_auto_connect() & AutoConnectPhysical)) {
 					port = physoutputs[(channels_used+x)%nphysical_out];
 				} else if (Config->get_output_auto_connect() & AutoConnectMaster) {
@@ -1775,16 +1777,16 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
 						port = _master_out->input (x%_master_out->n_inputs().n_audio())->name();
 					}
 				}
-				
+
 				if (port.length() && track->connect_output (track->output (x), port, this)) {
 					break;
 				}
 			}
-			
+
 			channels_used += track->n_inputs ().n_audio();
 
 			track->audio_diskstream()->non_realtime_input_change();
-			
+
 			track->DiskstreamChanged.connect (mem_fun (this, &Session::resort_routes));
 			track->set_remote_control_id (control_id);
 			++control_id;
@@ -1800,7 +1802,7 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
 				/* we need to get rid of this, since the track failed to be created */
 				/* XXX arguably, AudioTrack::AudioTrack should not do the Session::add_diskstream() */
 
-				{ 
+				{
 					RCUWriter<DiskstreamList> writer (diskstreams);
 					boost::shared_ptr<DiskstreamList> ds = writer.get_copy();
 					ds->remove (track->audio_diskstream());
@@ -1818,7 +1820,7 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
 				/* we need to get rid of this, since the track failed to be created */
 				/* XXX arguably, AudioTrack::AudioTrack should not do the Session::add_diskstream() */
 
-				{ 
+				{
 					RCUWriter<DiskstreamList> writer (diskstreams);
 					boost::shared_ptr<DiskstreamList> ds = writer.get_copy();
 					ds->remove (track->audio_diskstream());
@@ -1847,14 +1849,14 @@ Session::set_remote_control_ids ()
 	shared_ptr<RouteList> r = routes.reader ();
 
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-		if ( MixerOrdered == m) {			
+		if ( MixerOrdered == m) {
 			long order = (*i)->order_key(N_("signal"));
 			(*i)->set_remote_control_id( order+1 );
 		} else if ( EditorOrdered == m) {
 			long order = (*i)->order_key(N_("editor"));
 			(*i)->set_remote_control_id( order+1 );
 		} else if ( UserOrdered == m) {
-			//do nothing ... only changes to remote id's are initiated by user 
+			//do nothing ... only changes to remote id's are initiated by user
 		}
 	}
 }
@@ -1906,31 +1908,31 @@ Session::new_audio_route (int input_channels, int output_channels, uint32_t how_
 
 		try {
 			shared_ptr<Route> bus (new Route (*this, bus_name, -1, -1, -1, -1, Route::Flag(0), DataType::AUDIO));
-			
+
 			if (bus->ensure_io (ChanCount(DataType::AUDIO, input_channels), ChanCount(DataType::AUDIO, output_channels), false, this)) {
 				error << string_compose (_("cannot configure %1 in/%2 out configuration for new audio track"),
 							 input_channels, output_channels)
 				      << endmsg;
 				goto failure;
 			}
-			
+
 			for (uint32_t x = 0; n_physical_inputs && x < bus->n_inputs().n_audio(); ++x) {
-				
+
 				port = "";
 
 				if (Config->get_input_auto_connect() & AutoConnectPhysical) {
 						port = physinputs[((n+x)%n_physical_inputs)];
-				} 
-				
+				}
+
 				if (port.length() && bus->connect_input (bus->input (x), port, this)) {
 					break;
 				}
 			}
-			
+
 			for (uint32_t x = 0; n_physical_outputs && x < bus->n_outputs().n_audio(); ++x) {
-				
+
 				port = "";
-				
+
 				if (Config->get_output_auto_connect() & AutoConnectPhysical) {
 					port = physoutputs[((n+x)%n_physical_outputs)];
 				} else if (Config->get_output_auto_connect() & AutoConnectMaster) {
@@ -1938,18 +1940,18 @@ Session::new_audio_route (int input_channels, int output_channels, uint32_t how_
 						port = _master_out->input (x%_master_out->n_inputs().n_audio())->name();
 					}
 				}
-				
+
 				if (port.length() && bus->connect_output (bus->output (x), port, this)) {
 					break;
 				}
 			}
-			
+
 			bus->set_remote_control_id (control_id);
 			++control_id;
 
 			ret.push_back (bus);
 		}
-	
+
 
 		catch (failed_constructor &err) {
 			error << _("Session: could not create new audio route.") << endmsg;
@@ -1977,7 +1979,7 @@ Session::new_audio_route (int input_channels, int output_channels, uint32_t how_
 void
 Session::add_routes (RouteList& new_routes, bool save)
 {
-	{ 
+	{
 		RCUWriter<RouteList> writer (routes);
 		shared_ptr<RouteList> r = writer.get_copy ();
 		r->insert (r->end(), new_routes.begin(), new_routes.end());
@@ -1985,18 +1987,18 @@ Session::add_routes (RouteList& new_routes, bool save)
 	}
 
 	for (RouteList::iterator x = new_routes.begin(); x != new_routes.end(); ++x) {
-		
+
 		boost::weak_ptr<Route> wpr (*x);
 
 		(*x)->solo_changed.connect (sigc::bind (mem_fun (*this, &Session::route_solo_changed), wpr));
 		(*x)->mute_changed.connect (mem_fun (*this, &Session::route_mute_changed));
 		(*x)->output_changed.connect (mem_fun (*this, &Session::set_worst_io_latencies_x));
 		(*x)->processors_changed.connect (bind (mem_fun (*this, &Session::update_latency_compensation), false, false));
-		
+
 		if ((*x)->is_master()) {
 			_master_out = (*x);
 		}
-		
+
 		if ((*x)->is_control()) {
 			_control_out = (*x);
 		}
@@ -2017,7 +2019,7 @@ Session::add_routes (RouteList& new_routes, bool save)
 		for (RouteList::iterator x = new_routes.begin(); x != new_routes.end(); ++x) {
 			(*x)->set_control_outs (cports);
 		}
-	} 
+	}
 
 	set_dirty();
 
@@ -2033,7 +2035,7 @@ Session::add_diskstream (boost::shared_ptr<Diskstream> dstream)
 {
 	/* need to do this in case we're rolling at the time, to prevent false underruns */
 	dstream->do_refill_with_alloc ();
-	
+
 	dstream->set_block_size (current_block_size);
 
 	{
@@ -2041,7 +2043,7 @@ Session::add_diskstream (boost::shared_ptr<Diskstream> dstream)
 		boost::shared_ptr<DiskstreamList> ds = writer.get_copy();
 		ds->push_back (dstream);
 		/* writer goes out of scope, copies ds back to main */
-	} 
+	}
 
 	dstream->PlaylistChanged.connect (sigc::bind (mem_fun (*this, &Session::diskstream_playlist_changed), dstream));
 	/* this will connect to future changes, and check the current length */
@@ -2054,10 +2056,10 @@ Session::add_diskstream (boost::shared_ptr<Diskstream> dstream)
 void
 Session::remove_route (shared_ptr<Route> route)
 {
-	{ 	
+	{
 		RCUWriter<RouteList> writer (routes);
 		shared_ptr<RouteList> rs = writer.get_copy ();
-		
+
 		rs->remove (route);
 
 		/* deleting the master out seems like a dumb
@@ -2082,17 +2084,17 @@ Session::remove_route (shared_ptr<Route> route)
 		}
 
 		update_route_solo_state ();
-		
+
 		/* writer goes out of scope, forces route list update */
 	}
 
 	Track* t;
 	boost::shared_ptr<Diskstream> ds;
-	
+
 	if ((t = dynamic_cast<Track*>(route.get())) != 0) {
 		ds = t->diskstream();
 	}
-	
+
 	if (ds) {
 
 		{
@@ -2103,12 +2105,12 @@ Session::remove_route (shared_ptr<Route> route)
 	}
 
 	find_current_end ();
-	
-	// We need to disconnect the routes inputs and outputs 
+
+	// We need to disconnect the routes inputs and outputs
 
 	route->disconnect_inputs (0);
 	route->disconnect_outputs (0);
-	
+
 	update_latency_compensation (false, false);
 	set_dirty();
 
@@ -2127,7 +2129,7 @@ Session::remove_route (shared_ptr<Route> route)
 	if (save_state (_current_snapshot_name)) {
 		save_history (_current_snapshot_name);
 	}
-}	
+}
 
 void
 Session::route_mute_changed (void* src)
@@ -2137,12 +2139,12 @@ Session::route_mute_changed (void* src)
 
 void
 Session::route_solo_changed (void* src, boost::weak_ptr<Route> wpr)
-{      
+{
 	if (solo_update_disabled) {
 		// We know already
 		return;
 	}
-	
+
 	bool is_track;
 	boost::shared_ptr<Route> route = wpr.lock ();
 
@@ -2153,46 +2155,46 @@ Session::route_solo_changed (void* src, boost::weak_ptr<Route> wpr)
 	}
 
 	is_track = (boost::dynamic_pointer_cast<AudioTrack>(route) != 0);
-	
+
 	shared_ptr<RouteList> r = routes.reader ();
 
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-		
+
 		/* soloing a track mutes all other tracks, soloing a bus mutes all other busses */
-		
+
 		if (is_track) {
-			
+
 			/* don't mess with busses */
-			
+
 			if (dynamic_cast<Track*>((*i).get()) == 0) {
 				continue;
 			}
-			
+
 		} else {
-			
+
 			/* don't mess with tracks */
-			
+
 			if (dynamic_cast<Track*>((*i).get()) != 0) {
 				continue;
 			}
 		}
-		
+
 		if ((*i) != route &&
 		    ((*i)->mix_group () == 0 ||
 		     (*i)->mix_group () != route->mix_group () ||
 		     !route->mix_group ()->is_active())) {
-			
+
 			if ((*i)->soloed()) {
-				
+
 				/* if its already soloed, and solo latching is enabled,
 				   then leave it as it is.
 				*/
-				
+
 				if (Config->get_solo_latched()) {
 					continue;
-				} 
+				}
 			}
-			
+
 			/* do it */
 
 			solo_update_disabled = true;
@@ -2200,7 +2202,7 @@ Session::route_solo_changed (void* src, boost::weak_ptr<Route> wpr)
 			solo_update_disabled = false;
 		}
 	}
-	
+
 	bool something_soloed = false;
 	bool same_thing_soloed = false;
 	bool signal = false;
@@ -2222,12 +2224,12 @@ Session::route_solo_changed (void* src, boost::weak_ptr<Route> wpr)
 			break;
 		}
 	}
-	
+
 	if (something_soloed != currently_soloing) {
 		signal = true;
 		currently_soloing = something_soloed;
 	}
-	
+
 	modify_solo_mute (is_track, same_thing_soloed);
 
 	if (signal) {
@@ -2251,7 +2253,7 @@ Session::update_route_solo_state ()
 	/* this is where we actually implement solo by changing
 	   the solo mute setting of each track.
 	*/
-	
+
 	shared_ptr<RouteList> r = routes.reader ();
 
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
@@ -2276,7 +2278,7 @@ Session::update_route_solo_state ()
 		for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 			(*i)->set_solo_mute (false);
 		}
-		
+
 		if (signal) {
 			SoloActive (false);
 		}
@@ -2297,11 +2299,11 @@ Session::modify_solo_mute (bool is_track, bool mute)
 	shared_ptr<RouteList> r = routes.reader ();
 
         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-		
+
 		if (is_track) {
-			
+
 			/* only alter track solo mute */
-			
+
 			if (dynamic_cast<Track*>((*i).get())) {
 				if ((*i)->soloed()) {
 					(*i)->set_solo_mute (!mute);
@@ -2325,7 +2327,7 @@ Session::modify_solo_mute (bool is_track, bool mute)
 					/* don't mute master or control outs
 					   in response to another bus solo
 					*/
-					
+
 					if ((*i) != _master_out &&
 					    (*i) != _control_out) {
 						(*i)->set_solo_mute (mute);
@@ -2335,7 +2337,7 @@ Session::modify_solo_mute (bool is_track, bool mute)
 
 		}
 	}
-}	
+}
 
 
 void
@@ -2347,8 +2349,8 @@ Session::catch_up_on_solo ()
 	   has.
 	*/
 	update_route_solo_state();
-}	
-		
+}
+
 shared_ptr<Route>
 Session::route_by_name (string name)
 {
@@ -2411,7 +2413,7 @@ nframes_t
 Session::get_maximum_extent () const
 {
 	nframes_t max = 0;
-	nframes_t me; 
+	nframes_t me;
 
 	boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 
@@ -2464,7 +2466,7 @@ Session::new_region_name (string old)
 	char buf[len];
 
 	if ((last_period = old.find_last_of ('.')) == string::npos) {
-		
+
 		/* no period present - add one explicitly */
 
 		old += '.';
@@ -2492,7 +2494,7 @@ Session::new_region_name (string old)
 				break;
 			}
 		}
-		
+
 		if (i == regions.end()) {
 			break;
 		}
@@ -2500,7 +2502,7 @@ Session::new_region_name (string old)
 
 	if (number != (UINT_MAX-1)) {
 		return buf;
-	} 
+	}
 
 	error << string_compose (_("cannot create new name for region \"%1\""), old) << endmsg;
 	return old;
@@ -2515,19 +2517,19 @@ Session::region_name (string& result, string base, bool newlevel) const
 	assert(base.find("/") == string::npos);
 
 	if (base == "") {
-		
+
 		Glib::Mutex::Lock lm (region_lock);
 
 		snprintf (buf, sizeof (buf), "%d", (int)regions.size() + 1);
 
-		
+
 		result = "region.";
 		result += buf;
 
 	} else {
 
 		/* XXX this is going to be slow. optimize me later */
-		
+
 		if (newlevel) {
 			subbase = base;
 		} else {
@@ -2542,38 +2544,38 @@ Session::region_name (string& result, string base, bool newlevel) const
 		}
 
 		bool name_taken = true;
-		
+
 		{
 			Glib::Mutex::Lock lm (region_lock);
-			
+
 			for (int n = 1; n < 5000; ++n) {
-				
+
 				result = subbase;
 				snprintf (buf, sizeof (buf), ".%d", n);
 				result += buf;
-				
+
 				name_taken = false;
-				
+
 				for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
 					if (i->second->name() == result) {
 						name_taken = true;
 						break;
 					}
 				}
-				
+
 				if (!name_taken) {
 					break;
 				}
 			}
 		}
-			
+
 		if (name_taken) {
 			fatal << string_compose(_("too many regions with names like %1"), base) << endmsg;
 			/*NOTREACHED*/
 		}
 	}
 	return 0;
-}	
+}
 
 void
 Session::add_region (boost::shared_ptr<Region> region)
@@ -2582,49 +2584,49 @@ Session::add_region (boost::shared_ptr<Region> region)
 	v.push_back (region);
 	add_regions (v);
 }
-		
+
 void
 Session::add_regions (vector<boost::shared_ptr<Region> >& new_regions)
 {
 	bool added = false;
 
-	{ 
+	{
 		Glib::Mutex::Lock lm (region_lock);
 
 		for (vector<boost::shared_ptr<Region> >::iterator ii = new_regions.begin(); ii != new_regions.end(); ++ii) {
-		
+
 			boost::shared_ptr<Region> region = *ii;
-			
+
 			if (region == 0) {
 
 				error << _("Session::add_region() ignored a null region. Warning: you might have lost a region.") << endmsg;
 
 			} else {
-				
+
 				RegionList::iterator x;
-				
+
 				for (x = regions.begin(); x != regions.end(); ++x) {
-					
+
 					if (region->region_list_equivalent (x->second)) {
 						break;
 					}
 				}
-				
+
 				if (x == regions.end()) {
-					
+
 					pair<RegionList::key_type,RegionList::mapped_type> entry;
-					
+
 					entry.first = region->id();
 					entry.second = region;
-					
+
 					pair<RegionList::iterator,bool> x = regions.insert (entry);
-					
+
 					if (!x.second) {
 						return;
 					}
-					
+
 					added = true;
-				} 
+				}
 			}
 		}
 	}
@@ -2632,9 +2634,9 @@ Session::add_regions (vector<boost::shared_ptr<Region> >& new_regions)
 	/* mark dirty because something has changed even if we didn't
 	   add the region to the region list.
 	*/
-	
+
 	set_dirty();
-	
+
 	if (added) {
 
 		vector<boost::weak_ptr<Region> > v;
@@ -2659,7 +2661,7 @@ Session::add_regions (vector<boost::shared_ptr<Region> >& new_regions)
 			region->StateChanged.connect (sigc::bind (mem_fun (*this, &Session::region_changed), boost::weak_ptr<Region>(region)));
 			region->GoingAway.connect (sigc::bind (mem_fun (*this, &Session::remove_region), boost::weak_ptr<Region>(region)));
 		}
-		
+
 		if (!v.empty()) {
 			RegionsAdded (v); /* EMIT SIGNAL */
 		}
@@ -2693,7 +2695,7 @@ Session::remove_region (boost::weak_ptr<Region> weak_region)
 
 	bool removed = false;
 
-	{ 
+	{
 		Glib::Mutex::Lock lm (region_lock);
 
 		if ((i = regions.find (region->id())) != regions.end()) {
@@ -2718,7 +2720,7 @@ Session::find_whole_file_parent (boost::shared_ptr<Region const> child)
 {
 	RegionList::iterator i;
 	boost::shared_ptr<Region> region;
-	
+
 	Glib::Mutex::Lock lm (region_lock);
 
 	for (i = regions.begin(); i != regions.end(); ++i) {
@@ -2731,10 +2733,10 @@ Session::find_whole_file_parent (boost::shared_ptr<Region const> child)
 				return region;
 			}
 		}
-	} 
+	}
 
 	return boost::shared_ptr<Region> ();
-}	
+}
 
 void
 Session::find_equivalent_playlist_regions (boost::shared_ptr<Region> region, vector<boost::shared_ptr<Region> >& result)
@@ -2747,12 +2749,12 @@ int
 Session::destroy_region (boost::shared_ptr<Region> region)
 {
 	vector<boost::shared_ptr<Source> > srcs;
-		
+
 	{
 		if (region->playlist()) {
 			region->playlist()->destroy_region (region);
 		}
-		
+
 		for (uint32_t n = 0; n < region->n_channels(); ++n) {
 			srcs.push_back (region->source (n));
 		}
@@ -2764,7 +2766,7 @@ Session::destroy_region (boost::shared_ptr<Region> region)
 
 			(*i)->mark_for_remove ();
 			(*i)->drop_references ();
-			
+
 			cerr << "source was not used by any playlist\n";
 	}
 
@@ -2784,12 +2786,12 @@ int
 Session::remove_last_capture ()
 {
 	list<boost::shared_ptr<Region> > r;
-	
+
 	boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
-	
+
 	for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 		list<boost::shared_ptr<Region> >& l = (*i)->last_capture_regions();
-		
+
 		if (!l.empty()) {
 			r.insert (r.end(), l.begin(), l.end());
 			l.clear ();
@@ -2819,7 +2821,7 @@ Session::add_source (boost::shared_ptr<Source> source)
 
 	entry.first = source->id();
 	entry.second = source;
-	
+
 	{
 		Glib::Mutex::Lock lm (source_lock);
 		result = sources.insert (entry);
@@ -2829,14 +2831,14 @@ Session::add_source (boost::shared_ptr<Source> source)
 		source->GoingAway.connect (sigc::bind (mem_fun (this, &Session::remove_source), boost::weak_ptr<Source> (source)));
 		set_dirty();
 	}
-	
+
 	boost::shared_ptr<AudioFileSource> afs;
 
 	if ((afs = boost::dynamic_pointer_cast<AudioFileSource>(source)) != 0) {
 		if (Config->get_auto_analyse_audio()) {
 			Analyser::queue_source_for_analysis (source, false);
 		}
-	} 
+	}
 }
 
 void
@@ -2847,22 +2849,22 @@ Session::remove_source (boost::weak_ptr<Source> src)
 
 	if (!source) {
 		return;
-	} 
+	}
 
-	{ 
+	{
 		Glib::Mutex::Lock lm (source_lock);
 
 		if ((i = sources.find (source->id())) != sources.end()) {
 			sources.erase (i);
-		} 
+		}
 	}
-	
+
 	if (!_state_of_the_state & InCleanup) {
-		
+
 		/* save state so we don't end up with a session file
 		   referring to non-existent sources.
 		*/
-		
+
 		save_state (_current_snapshot_name);
 	}
 }
@@ -2893,8 +2895,8 @@ Session::source_by_path_and_channel (const Glib::ustring& path, uint16_t chn)
 
 		if (afs && afs->path() == path && chn == afs->channel()) {
 			return afs;
-		} 
-		       
+		}
+
 	}
 	return boost::shared_ptr<Source>();
 }
@@ -2917,14 +2919,14 @@ Session::change_audio_path_by_name (string path, string oldname, string newname,
 	/* note: we know (or assume) the old path is already valid */
 
 	if (destructive) {
-		
+
 		/* destructive file sources have a name of the form:
 
 		    /path/to/Tnnnn-NAME(%[LR])?.wav
-		  
+
 		    the task here is to replace NAME with the new name.
 		*/
-		
+
 		/* find last slash */
 
 		string dir;
@@ -2951,16 +2953,16 @@ Session::change_audio_path_by_name (string path, string oldname, string newname,
 		path += '-';
 		path += new_legalized;
 		path += ".wav";  /* XXX gag me with a spoon */
-		
+
 	} else {
-		
+
 		/* non-destructive file sources have a name of the form:
 
 		    /path/to/NAME-nnnnn(%[LR])?.wav
-		  
+
 		    the task here is to replace NAME with the new name.
 		*/
-		
+
 		string dir;
 		string suffix;
 		string::size_type slash;
@@ -2982,7 +2984,7 @@ Session::change_audio_path_by_name (string path, string oldname, string newname,
 		}
 
 		suffix = path.substr (dash+1);
-		
+
 		// Suffix is now everything after the dash. Now we need to eliminate
 		// the nnnnn part, which is done by either finding a '%' or a '.'
 
@@ -3085,7 +3087,7 @@ Session::audio_path_from_name (string name, uint32_t nchan, uint32_t chan, bool
 
 			if (sys::exists(buf)) {
 				existing++;
-			} 
+			}
 
 		}
 
@@ -3112,7 +3114,7 @@ Session::audio_path_from_name (string name, uint32_t nchan, uint32_t chan, bool
 	spath += '/';
 
 	string::size_type pos = foo.find_last_of ('/');
-	
+
 	if (pos == string::npos) {
 		spath += foo;
 	} else {
@@ -3141,14 +3143,14 @@ Session::change_midi_path_by_name (string path, string oldname, string newname,
 	/* note: we know (or assume) the old path is already valid */
 
 	if (destructive) {
-		
+
 		/* destructive file sources have a name of the form:
 
 		    /path/to/Tnnnn-NAME(%[LR])?.wav
-		  
+
 		    the task here is to replace NAME with the new name.
 		*/
-		
+
 		/* find last slash */
 
 		string dir;
@@ -3175,16 +3177,16 @@ Session::change_midi_path_by_name (string path, string oldname, string newname,
 		path += '-';
 		path += new_legalized;
 		path += ".mid";  /* XXX gag me with a spoon */
-		
+
 	} else {
-		
+
 		/* non-destructive file sources have a name of the form:
 
 		    /path/to/NAME-nnnnn(%[LR])?.wav
-		  
+
 		    the task here is to replace NAME with the new name.
 		*/
-		
+
 		string dir;
 		string suffix;
 		string::size_type slash;
@@ -3206,7 +3208,7 @@ Session::change_midi_path_by_name (string path, string oldname, string newname,
 		}
 
 		suffix = path.substr (dash+1);
-		
+
 		// Suffix is now everything after the dash. Now we need to eliminate
 		// the nnnnn part, which is done by either finding a '%' or a '.'
 
@@ -3269,7 +3271,7 @@ Session::midi_path_from_name (string name)
 		for (i = session_dirs.begin(); i != session_dirs.end(); ++i) {
 
 			SessionDirectory sdir((*i).path);
-		
+
 			sys::path p = sdir.midi_path();
 
 			p /= legalized;
@@ -3280,7 +3282,7 @@ Session::midi_path_from_name (string name)
 
 			if (sys::exists (buf)) {
 				existing++;
-			} 
+			}
 		}
 
 		if (existing == 0) {
@@ -3305,7 +3307,7 @@ Session::midi_path_from_name (string name)
 	spath += '/';
 
 	string::size_type pos = foo.find_last_of ('/');
-	
+
 	if (pos == string::npos) {
 		spath += foo;
 	} else {
@@ -3314,12 +3316,12 @@ Session::midi_path_from_name (string name)
 
 	return spath;
 }
-	
+
 boost::shared_ptr<MidiSource>
 Session::create_midi_source_for_session (MidiDiskstream& ds)
 {
 	string mpath = midi_path_from_name (ds.name());
-	
+
 	return boost::dynamic_pointer_cast<SMFSource> (SourceFactory::createWritable (DataType::MIDI, *this, mpath, false, frame_rate()));
 }
 
@@ -3351,7 +3353,7 @@ Session::add_playlist (boost::shared_ptr<Playlist> playlist)
 		return;
 	}
 
-	{ 
+	{
 		Glib::Mutex::Lock lm (playlist_lock);
 		if (find (playlists.begin(), playlists.end(), playlist) == playlists.end()) {
 			playlists.insert (playlists.begin(), playlist);
@@ -3368,7 +3370,7 @@ Session::add_playlist (boost::shared_ptr<Playlist> playlist)
 void
 Session::get_playlists (vector<boost::shared_ptr<Playlist> >& s)
 {
-	{ 
+	{
 		Glib::Mutex::Lock lm (playlist_lock);
 		for (PlaylistList::iterator i = playlists.begin(); i != playlists.end(); ++i) {
 			s.push_back (*i);
@@ -3395,22 +3397,22 @@ Session::track_playlist (bool inuse, boost::weak_ptr<Playlist> wpl)
 		return;
 	}
 
-	{ 
+	{
 		Glib::Mutex::Lock lm (playlist_lock);
 
 		if (!inuse) {
 
 			unused_playlists.insert (pl);
-			
+
 			if ((x = playlists.find (pl)) != playlists.end()) {
 				playlists.erase (x);
 			}
 
-			
+
 		} else {
 
 			playlists.insert (pl);
-			
+
 			if ((x = unused_playlists.find (pl)) != unused_playlists.end()) {
 				unused_playlists.erase (x);
 			}
@@ -3431,7 +3433,7 @@ Session::remove_playlist (boost::weak_ptr<Playlist> weak_playlist)
 		return;
 	}
 
-	{ 
+	{
 		Glib::Mutex::Lock lm (playlist_lock);
 
 		PlaylistList::iterator i;
@@ -3445,7 +3447,7 @@ Session::remove_playlist (boost::weak_ptr<Playlist> weak_playlist)
 		if (i != unused_playlists.end()) {
 			unused_playlists.erase (i);
 		}
-		
+
 	}
 
 	set_dirty();
@@ -3453,7 +3455,7 @@ Session::remove_playlist (boost::weak_ptr<Playlist> weak_playlist)
 	PlaylistRemoved (playlist); /* EMIT SIGNAL */
 }
 
-void 
+void
 Session::set_audition (boost::shared_ptr<Region> r)
 {
 	pending_audition_region = r;
@@ -3510,7 +3512,7 @@ Session::remove_empty_sounds ()
 	vector<string> audio_filenames;
 
 	get_files_in_directory (_session_dir->sound_path(), audio_filenames);
-	
+
 	Glib::Mutex::Lock lm (source_lock);
 
 	TapeFileMatcher tape_file_matcher;
@@ -3523,7 +3525,7 @@ Session::remove_empty_sounds ()
 		sys::path audio_file_path (_session_dir->sound_path());
 
 		audio_file_path /= *i;
-			
+
 		if (AudioFileSource::is_empty (*this, audio_file_path.to_string())) {
 
 			try
@@ -3534,7 +3536,7 @@ Session::remove_empty_sounds ()
 			}
 			catch (const sys::filesystem_error& err)
 			{
-				error << err.what() << endmsg; 
+				error << err.what() << endmsg;
 			}
 		}
 	}
@@ -3555,7 +3557,7 @@ void
 Session::set_all_solo (bool yn)
 {
 	shared_ptr<RouteList> r = routes.reader ();
-	
+
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 		if (!(*i)->is_hidden()) {
 			(*i)->set_solo (yn, this);
@@ -3564,12 +3566,12 @@ Session::set_all_solo (bool yn)
 
 	set_dirty();
 }
-		
+
 void
 Session::set_all_mute (bool yn)
 {
 	shared_ptr<RouteList> r = routes.reader ();
-	
+
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 		if (!(*i)->is_hidden()) {
 			(*i)->set_mute (yn, this);
@@ -3578,7 +3580,7 @@ Session::set_all_mute (bool yn)
 
 	set_dirty();
 }
-		
+
 uint32_t
 Session::n_diskstreams () const
 {
@@ -3604,7 +3606,7 @@ Session::graph_reordered ()
 	if (_state_of_the_state & InitialConnecting) {
 		return;
 	}
-	
+
 	/* every track/bus asked for this to be handled but it was deferred because
 	   we were connecting. do it now.
 	*/
@@ -3613,10 +3615,10 @@ Session::graph_reordered ()
 
 	resort_routes ();
 
-	/* force all diskstreams to update their capture offset values to 
+	/* force all diskstreams to update their capture offset values to
 	   reflect any changes in latencies within the graph.
 	*/
-	
+
 	boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 
 	for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
@@ -3640,7 +3642,7 @@ void
 Session::record_enable_change_all (bool yn)
 {
 	shared_ptr<RouteList> r = routes.reader ();
-	
+
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 		Track* at;
 
@@ -3648,7 +3650,7 @@ Session::record_enable_change_all (bool yn)
 			at->set_record_enable (yn, this);
 		}
 	}
-	
+
 	/* since we don't keep rec-enable state, don't mark session dirty */
 }
 
@@ -3681,7 +3683,7 @@ Session::remove_processor (Processor* processor)
 	Send* send;
 	PortInsert* port_insert;
 	PluginInsert* plugin_insert;
-	
+
 	if ((port_insert = dynamic_cast<PortInsert *> (processor)) != 0) {
 		list<PortInsert*>::iterator x = find (_port_inserts.begin(), _port_inserts.end(), port_insert);
 		if (x != _port_inserts.end()) {
@@ -3722,7 +3724,7 @@ Session::available_capture_duration ()
 		sample_bytes_on_disk = 2.0;
 		break;
 
-	default: 
+	default:
 		/* impossible, but keep some gcc versions happy */
 		fatal << string_compose (_("programming error: %1"),
 					 X_("illegal native file data format"))
@@ -3735,7 +3737,7 @@ Session::available_capture_duration ()
 	if (_total_free_4k_blocks * scale > (double) max_frames) {
 		return max_frames;
 	}
-	
+
 	return (nframes_t) floor (_total_free_4k_blocks * scale);
 }
 
@@ -3746,7 +3748,7 @@ Session::add_bundle (shared_ptr<Bundle> bundle)
 		Glib::Mutex::Lock guard (bundle_lock);
 		_bundles.push_back (bundle);
 	}
-	
+
 	BundleAdded (bundle); /* EMIT SIGNAL */
 
 	set_dirty();
@@ -3760,7 +3762,7 @@ Session::remove_bundle (shared_ptr<Bundle> bundle)
 	{
 		Glib::Mutex::Lock guard (bundle_lock);
 		BundleList::iterator i = find (_bundles.begin(), _bundles.end(), bundle);
-		
+
 		if (i != _bundles.end()) {
 			_bundles.erase (i);
 			removed = true;
@@ -3792,7 +3794,7 @@ void
 Session::tempo_map_changed (Change ignored)
 {
 	clear_clicks ();
-	
+
 	for (PlaylistList::iterator i = playlists.begin(); i != playlists.end(); ++i) {
 		(*i)->update_after_tempo_map_change ();
 	}
@@ -3812,7 +3814,7 @@ Session::ensure_buffers (ChanCount howmany)
 {
 	if (current_block_size == 0)
 		return; // too early? (is this ok?)
-	
+
 	// We need at least 2 MIDI scratch buffers to mix/merge
 	if (howmany.n_midi() < 2)
 		howmany.set_midi(2);
@@ -3822,7 +3824,7 @@ Session::ensure_buffers (ChanCount howmany)
 	_scratch_buffers->ensure_buffers(howmany, current_block_size);
 	_mix_buffers->ensure_buffers(howmany, current_block_size);
 	_silent_buffers->ensure_buffers(howmany, current_block_size);
-	
+
 	allocate_pan_automation_buffers (current_block_size, howmany.n_audio(), false);
 }
 
@@ -3836,10 +3838,10 @@ Session::next_insert_id ()
 			if (!insert_bitset[n]) {
 				insert_bitset[n] = true;
 				return n;
-				
+
 			}
 		}
-		
+
 		/* none available, so resize and try again */
 
 		insert_bitset.resize (insert_bitset.size() + 16, false);
@@ -3856,10 +3858,10 @@ Session::next_send_id ()
 			if (!send_bitset[n]) {
 				send_bitset[n] = true;
 				return n;
-				
+
 			}
 		}
-		
+
 		/* none available, so resize and try again */
 
 		send_bitset.resize (send_bitset.size() + 16, false);
@@ -3907,7 +3909,7 @@ Session::named_selection_by_name (string name)
 void
 Session::add_named_selection (NamedSelection* named_selection)
 {
-	{ 
+	{
 		Glib::Mutex::Lock lm (named_selection_lock);
 		named_selections.insert (named_selections.begin(), named_selection);
 	}
@@ -3926,7 +3928,7 @@ Session::remove_named_selection (NamedSelection* named_selection)
 {
 	bool removed = false;
 
-	{ 
+	{
 		Glib::Mutex::Lock lm (named_selection_lock);
 
 		NamedSelectionList::iterator i = find (named_selections.begin(), named_selections.end(), named_selection);
@@ -3958,13 +3960,13 @@ bool
 Session::route_name_unique (string n) const
 {
 	shared_ptr<RouteList> r = routes.reader ();
-	
+
 	for (RouteList::const_iterator i = r->begin(); i != r->end(); ++i) {
 		if ((*i)->name() == n) {
 			return false;
 		}
 	}
-	
+
 	return true;
 }
 
@@ -3992,7 +3994,7 @@ Session::allocate_pan_automation_buffers (nframes_t nframes, uint32_t howmany, b
 	}
 
 	_pan_automation_buffer = new pan_t*[howmany];
-	
+
 	for (uint32_t i = 0; i < howmany; ++i) {
 		_pan_automation_buffer[i] = new pan_t[nframes];
 	}
@@ -4021,7 +4023,7 @@ Session::freeze (InterThreadInfo& itt)
 }
 
 int
-Session::write_one_audio_track (AudioTrack& track, nframes_t start, nframes_t len, 	
+Session::write_one_audio_track (AudioTrack& track, nframes_t start, nframes_t len,
 			       bool overwrite, vector<boost::shared_ptr<Source> >& srcs, InterThreadInfo& itt)
 {
 	int ret = -1;
@@ -4041,9 +4043,9 @@ Session::write_one_audio_track (AudioTrack& track, nframes_t start, nframes_t le
 	const nframes_t chunk_size = (128 * 1024)/4;
 
 	g_atomic_int_set (&processing_prohibited, 1);
-	
+
 	/* call tree *MUST* hold route_lock */
-	
+
 	if ((playlist = track.diskstream()->playlist()) == 0) {
 		goto out;
 	}
@@ -4062,17 +4064,17 @@ Session::write_one_audio_track (AudioTrack& track, nframes_t start, nframes_t le
 				break;
 			}
 		}
-		
+
 		if (x == 99999) {
 			error << string_compose (_("too many bounced versions of playlist \"%1\""), playlist->name()) << endmsg;
 			goto out;
 		}
-		
+
 		try {
 			fsource = boost::dynamic_pointer_cast<AudioFileSource> (
 				SourceFactory::createWritable (DataType::AUDIO, *this, buf, false, frame_rate()));
 		}
-		
+
 		catch (failed_constructor& err) {
 			error << string_compose (_("cannot create new audio file \"%1\" for %2"), buf, track.name()) << endmsg;
 			goto out;
@@ -4082,7 +4084,7 @@ Session::write_one_audio_track (AudioTrack& track, nframes_t start, nframes_t le
 	}
 
 	/* XXX need to flush all redirects */
-	
+
 	position = start;
 	to_do = len;
 
@@ -4095,11 +4097,11 @@ Session::write_one_audio_track (AudioTrack& track, nframes_t start, nframes_t le
 		if (afs)
 			afs->prepare_for_peakfile_writes ();
 	}
-			
+
 	while (to_do && !itt.cancel) {
-		
+
 		this_chunk = min (to_do, chunk_size);
-		
+
 		if (track.export_stuff (buffers, start, this_chunk)) {
 			goto out;
 		}
@@ -4107,45 +4109,45 @@ Session::write_one_audio_track (AudioTrack& track, nframes_t start, nframes_t le
 		uint32_t n = 0;
 		for (vector<boost::shared_ptr<Source> >::iterator src=srcs.begin(); src != srcs.end(); ++src, ++n) {
 			boost::shared_ptr<AudioFileSource> afs = boost::dynamic_pointer_cast<AudioFileSource>(*src);
-			
+
 			if (afs) {
 				if (afs->write (buffers.get_audio(n).data(), this_chunk) != this_chunk) {
 					goto out;
 				}
 			}
 		}
-		
+
 		start += this_chunk;
 		to_do -= this_chunk;
-		
+
 		itt.progress = (float) (1.0 - ((double) to_do / len));
 
 	}
 
 	if (!itt.cancel) {
-		
+
 		time_t now;
 		struct tm* xnow;
 		time (&now);
 		xnow = localtime (&now);
-		
+
 		for (vector<boost::shared_ptr<Source> >::iterator src=srcs.begin(); src != srcs.end(); ++src) {
 			boost::shared_ptr<AudioFileSource> afs = boost::dynamic_pointer_cast<AudioFileSource>(*src);
-			
+
 			if (afs) {
 				afs->update_header (position, *xnow, now);
 				afs->flush_header ();
 			}
 		}
-		
+
 		/* construct a region to represent the bounced material */
 
-		boost::shared_ptr<Region> aregion = RegionFactory::create (srcs, 0, srcs.front()->length(), 
+		boost::shared_ptr<Region> aregion = RegionFactory::create (srcs, 0, srcs.front()->length(),
 									   region_name_from_path (srcs.front()->name(), true));
 
 		ret = 0;
 	}
-		
+
   out:
 	if (ret) {
 		for (vector<boost::shared_ptr<Source> >::iterator src = srcs.begin(); src != srcs.end(); ++src) {
@@ -4161,7 +4163,7 @@ Session::write_one_audio_track (AudioTrack& track, nframes_t start, nframes_t le
 	} else {
 		for (vector<boost::shared_ptr<Source> >::iterator src = srcs.begin(); src != srcs.end(); ++src) {
 			boost::shared_ptr<AudioFileSource> afs = boost::dynamic_pointer_cast<AudioFileSource>(*src);
-			
+
 			if (afs)
 				afs->done_with_peakfile_writes ();
 		}
@@ -4183,7 +4185,7 @@ Session::get_silent_buffers (ChanCount count)
 			_silent_buffers->get(*t, i).clear();
 		}
 	}
-	
+
 	return *_silent_buffers;
 }
 
@@ -4203,7 +4205,7 @@ Session::get_mix_buffers (ChanCount count)
 	return *_mix_buffers;
 }
 
-uint32_t 
+uint32_t
 Session::ntracks () const
 {
 	uint32_t n = 0;
@@ -4218,7 +4220,7 @@ Session::ntracks () const
 	return n;
 }
 
-uint32_t 
+uint32_t
 Session::nbusses () const
 {
 	uint32_t n = 0;
diff --git a/libs/ardour/session_midi.cc b/libs/ardour/session_midi.cc
index b4938636a2..a807c5e98b 100644
--- a/libs/ardour/session_midi.cc
+++ b/libs/ardour/session_midi.cc
@@ -1,6 +1,6 @@
 
 /*
-  Copyright (C) 1999-2002 Paul Davis 
+  Copyright (C) 1999-2002 Paul Davis
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -94,8 +94,14 @@ Session::use_config_midi_ports ()
 		set_midi_port ("");
 	}
 
+	if (default_midi_clock_port) {
+		set_midi_clock_port (default_midi_clock_port->name());
+	} else {
+		set_midi_clock_port ("");
+	}
+
 	return 0;
-}	
+}
 
 
 /***********************************************************************
@@ -190,7 +196,7 @@ Session::set_mmc_port (string port_tag)
 		delete mmc;
 	}
 
-	mmc = new MIDI::MachineControl (*_mmc_port, 1.0, 
+	mmc = new MIDI::MachineControl (*_mmc_port, 1.0,
 					MMC_CommandSignature,
 					MMC_ResponseSignature);
 
@@ -199,29 +205,29 @@ Session::set_mmc_port (string port_tag)
 		mmc->set_send_device_id (old_send_device_id);
 	}
 
-	mmc->Play.connect 
+	mmc->Play.connect
 		(mem_fun (*this, &Session::mmc_deferred_play));
-	mmc->DeferredPlay.connect 
+	mmc->DeferredPlay.connect
 		(mem_fun (*this, &Session::mmc_deferred_play));
-	mmc->Stop.connect 
+	mmc->Stop.connect
 		(mem_fun (*this, &Session::mmc_stop));
-	mmc->FastForward.connect 
+	mmc->FastForward.connect
 		(mem_fun (*this, &Session::mmc_fast_forward));
-	mmc->Rewind.connect 
+	mmc->Rewind.connect
 		(mem_fun (*this, &Session::mmc_rewind));
-	mmc->Pause.connect 
+	mmc->Pause.connect
 		(mem_fun (*this, &Session::mmc_pause));
-	mmc->RecordPause.connect 
+	mmc->RecordPause.connect
 		(mem_fun (*this, &Session::mmc_record_pause));
-	mmc->RecordStrobe.connect 
+	mmc->RecordStrobe.connect
 		(mem_fun (*this, &Session::mmc_record_strobe));
-	mmc->RecordExit.connect 
+	mmc->RecordExit.connect
 		(mem_fun (*this, &Session::mmc_record_exit));
-	mmc->Locate.connect 
+	mmc->Locate.connect
 		(mem_fun (*this, &Session::mmc_locate));
-	mmc->Step.connect 
+	mmc->Step.connect
 		(mem_fun (*this, &Session::mmc_step));
-	mmc->Shuttle.connect 
+	mmc->Shuttle.connect
 		(mem_fun (*this, &Session::mmc_shuttle));
 	mmc->TrackRecordStatusChange.connect
 		(mem_fun (*this, &Session::mmc_record_enable));
@@ -232,7 +238,7 @@ Session::set_mmc_port (string port_tag)
 	_mmc_port->input()->start.connect (mem_fun (*this, &Session::spp_start));
 	_mmc_port->input()->contineu.connect (mem_fun (*this, &Session::spp_continue));
 	_mmc_port->input()->stop.connect (mem_fun (*this, &Session::spp_stop));
-	
+
 	Config->set_mmc_port_name (port_tag);
 
   out:
@@ -261,9 +267,9 @@ Session::set_midi_port (string port_tag)
 	}
 
 	_midi_port = port;
-	
+
 	/* XXX need something to forward this to control protocols ? or just
-	   use the signal below 
+	   use the signal below
 	*/
 
 	Config->set_midi_port_name (port_tag);
@@ -276,6 +282,52 @@ Session::set_midi_port (string port_tag)
 	return 0;
 }
 
+int
+Session::set_midi_clock_port (string port_tag)
+{
+	MIDIClock_Slave *ms;
+
+	if (port_tag.length() == 0) {
+
+		if (_slave && ((ms = dynamic_cast<MIDIClock_Slave*> (_slave)) != 0)) {
+			error << _("Ardour is slaved to MIDI Clock - port cannot be reset") << endmsg;
+			return -1;
+		}
+
+		if (_midi_clock_port == 0) {
+			return 0;
+		}
+
+		_midi_clock_port = 0;
+		goto out;
+	}
+
+	MIDI::Port* port;
+
+	if ((port = MIDI::Manager::instance()->port (port_tag)) == 0) {
+		error << string_compose (_("unknown port %1 requested for MIDI Clock"), port_tag) << endl;
+		return -1;
+	}
+
+	_midi_clock_port = port;
+
+	if (_slave && ((ms = dynamic_cast<MIDIClock_Slave*> (_slave)) != 0)) {
+		ms->rebind (*port);
+	}
+
+	Config->set_midi_clock_port_name (port_tag);
+
+	_midi_clock_port->input()->start.connect (mem_fun (*this, &Session::midi_clock_start));
+	_midi_clock_port->input()->contineu.connect (mem_fun (*this, &Session::midi_clock_continue));
+	_midi_clock_port->input()->stop.connect (mem_fun (*this, &Session::midi_clock_stop));
+
+  out:
+	MIDIClock_PortChanged(); /* EMIT SIGNAL */
+	change_midi_ports ();
+	set_dirty();
+	return 0;
+}
+
 void
 Session::set_trace_midi_input (bool yn, MIDI::Port* port)
 {
@@ -292,7 +344,7 @@ Session::set_trace_midi_input (bool yn, MIDI::Port* port)
 				input_parser->trace (yn, &cout, "input: ");
 			}
 		}
-		
+
 		if (_mtc_port && _mtc_port != _mmc_port) {
 			if ((input_parser = _mtc_port->input()) != 0) {
 				input_parser->trace (yn, &cout, "input: ");
@@ -324,7 +376,7 @@ Session::set_trace_midi_output (bool yn, MIDI::Port* port)
 				output_parser->trace (yn, &cout, "output: ");
 			}
 		}
-		
+
 		if (_mtc_port && _mtc_port != _mmc_port) {
 			if ((output_parser = _mtc_port->output()) != 0) {
 				output_parser->trace (yn, &cout, "output: ");
@@ -357,7 +409,7 @@ Session::get_trace_midi_input(MIDI::Port *port)
 				return input_parser->tracing();
 			}
 		}
-		
+
 		if (_mtc_port) {
 			if ((input_parser = _mtc_port->input()) != 0) {
 				return input_parser->tracing();
@@ -389,7 +441,7 @@ Session::get_trace_midi_output(MIDI::Port *port)
 				return output_parser->tracing();
 			}
 		}
-		
+
 		if (_mtc_port) {
 			if ((output_parser = _mtc_port->output()) != 0) {
 				return output_parser->tracing();
@@ -414,14 +466,14 @@ Session::setup_midi_control ()
 	next_quarter_frame_to_send = 0;
 
 	/* setup the MMC buffer */
-	
+
 	mmc_buffer[0] = 0xf0; // SysEx
 	mmc_buffer[1] = 0x7f; // Real Time SysEx ID for MMC
 	mmc_buffer[2] = (mmc ? mmc->send_device_id() : 0x7f);
 	mmc_buffer[3] = 0x6;  // MCC
 
 	/* Set up the qtr frame message */
-	
+
 	mtc_msg[0] = 0xf1;
 	mtc_msg[2] = 0xf1;
 	mtc_msg[4] = 0xf1;
@@ -455,6 +507,28 @@ Session::spp_stop (Parser& ignored)
 }
 
 void
+Session::midi_clock_start (Parser& ignored)
+{
+	if (Config->get_midi_clock_control() && (Config->get_slave_source() == MIDIClock)) {
+		request_transport_speed (1.0);
+	}
+}
+
+void
+Session::midi_clock_continue (Parser& ignored)
+{
+	midi_clock_start (ignored);
+}
+
+void
+Session::midi_clock_stop (Parser& ignored)
+{
+	if (Config->get_midi_clock_control()) {
+		request_stop ();
+	}
+}
+
+void
 Session::mmc_deferred_play (MIDI::MachineControl &mmc)
 {
 	if (Config->get_mmc_control() && (Config->get_slave_source() != MTC)) {
@@ -473,7 +547,7 @@ Session::mmc_record_pause (MIDI::MachineControl &mmc)
 void
 Session::mmc_record_strobe (MIDI::MachineControl &mmc)
 {
-	if (!Config->get_mmc_control()) 
+	if (!Config->get_mmc_control())
 		return;
 
 	/* record strobe does an implicit "Play" command */
@@ -485,11 +559,11 @@ Session::mmc_record_strobe (MIDI::MachineControl &mmc)
 		   its not the same as maybe_enable_record() though, because
 		   that *can* switch to Recording, which we do not want.
 		*/
-		
+
 		save_state ("", true);
 		g_atomic_int_set (&_record_status, Enabled);
 		RecordStateChanged (); /* EMIT SIGNAL */
-		
+
 		request_transport_speed (1.0);
 
 	} else {
@@ -545,7 +619,7 @@ Session::mmc_step (MIDI::MachineControl &mmc, int steps)
 	struct timeval diff = { 0, 0 };
 
 	gettimeofday (&now, 0);
-	
+
 	timersub (&now, &last_mmc_step, &diff);
 
 	gettimeofday (&now, 0);
@@ -554,10 +628,10 @@ Session::mmc_step (MIDI::MachineControl &mmc, int steps)
 	if (last_mmc_step.tv_sec != 0 && (diff.tv_usec + (diff.tv_sec * 1000000)) < _engine.usecs_per_cycle()) {
 		return;
 	}
-	
+
 	double diff_secs = diff.tv_sec + (diff.tv_usec / 1000000.0);
 	double cur_speed = (((steps * 0.5) * smpte_frames_per_second()) / diff_secs) / smpte_frames_per_second();
-	
+
 	if (_transport_speed == 0 || cur_speed * _transport_speed < 0) {
 		/* change direction */
 		step_speed = cur_speed;
@@ -568,13 +642,13 @@ Session::mmc_step (MIDI::MachineControl &mmc, int steps)
 	step_speed *= 0.25;
 
 #if 0
-	cerr << "delta = " << diff_secs 
+	cerr << "delta = " << diff_secs
 	     << " ct = " << _transport_speed
 	     << " steps = " << steps
-	     << " new speed = " << cur_speed 
+	     << " new speed = " << cur_speed
 	     << " speed = " << step_speed
 	     << endl;
-#endif	
+#endif
 
 	request_transport_speed (step_speed);
 	last_mmc_step = now;
@@ -617,10 +691,10 @@ Session::mmc_locate (MIDI::MachineControl &mmc, const MIDI::byte* mmc_tc)
 	smpte.frames = mmc_tc[3];
 	smpte.rate = smpte_frames_per_second();
 	smpte.drop = smpte_drop_frames();
-  
+
 	// Also takes smpte offset into account:
 	smpte_to_sample( smpte, target_frame, true /* use_offset */, false /* use_subframes */ );
-	
+
 	if (target_frame > max_frames) {
 		target_frame = max_frames;
 	}
@@ -667,7 +741,7 @@ Session::mmc_record_enable (MIDI::MachineControl &mmc, size_t trk, bool enabled)
 
 		RouteList::iterator i;
 		boost::shared_ptr<RouteList> r = routes.reader();
-		
+
 		for (i = r->begin(); i != r->end(); ++i) {
 			AudioTrack *at;
 
@@ -710,7 +784,7 @@ Session::send_full_time_code(nframes_t nframes)
 	if (_mtc_port == 0 || !session_send_mtc) {
 		return 0;
 	}
-	
+
 	// Get smpte time for this transport frame
 	sample_to_smpte(_transport_frame, smpte, true /* use_offset */, false /* no subframes */);
 
@@ -763,31 +837,31 @@ Session::send_full_time_code(nframes_t nframes)
  */
 int
 Session::send_midi_time_code_for_cycle(nframes_t nframes)
-{	
+{
 	assert (next_quarter_frame_to_send >= 0);
 	assert (next_quarter_frame_to_send <= 7);
-	
+
 	if (_mtc_port == 0 || !session_send_mtc || transmitting_smpte_time.negative
 	    /*|| (next_quarter_frame_to_send < 0)*/ ) {
 		// cerr << "(MTC) Not sending MTC\n";
 		return 0;
 	}
-	
+
 	/* Duration of one quarter frame */
 	nframes_t quarter_frame_duration = ((long) _frames_per_smpte_frame) >> 2;
-	
+
 	// cerr << "(MTC) TR: " << _transport_frame << " - SF: " << outbound_mtc_smpte_frame
 	// << " - NQ: " << next_quarter_frame_to_send << " - FD" << quarter_frame_duration << endl;
-		
+
 	// FIXME: this should always be true
 	//assert((outbound_mtc_smpte_frame + (next_quarter_frame_to_send * quarter_frame_duration))
 	//		> _transport_frame);
 
-	
+
 	// Send quarter frames for this cycle
 	while (_transport_frame + nframes > (outbound_mtc_smpte_frame +
 				(next_quarter_frame_to_send * quarter_frame_duration))) {
-		
+
 		// cerr << "(MTC) Next frame to send: " << next_quarter_frame_to_send << endl;
 
 		switch (next_quarter_frame_to_send) {
@@ -815,11 +889,11 @@ Session::send_midi_time_code_for_cycle(nframes_t nframes)
 			case 7:
 				mtc_msg[1] = 0x70 | (((mtc_smpte_bits|transmitting_smpte_time.hours) & 0xf0) >> 4);
 				break;
-		}			
-		
+		}
+
 		const nframes_t msg_time = (outbound_mtc_smpte_frame
 			+ (quarter_frame_duration * next_quarter_frame_to_send));
-	
+
 		// This message must fall within this block or something is broken
 		assert(msg_time >= _transport_frame);
 		assert(msg_time < _transport_frame + nframes);
@@ -828,7 +902,7 @@ Session::send_midi_time_code_for_cycle(nframes_t nframes)
 		assert(out_stamp < nframes);
 
 		if (_mtc_port->midimsg (mtc_msg, 2, out_stamp)) {
-			error << string_compose(_("Session: cannot send quarter-frame MTC message (%1)"), strerror (errno)) 
+			error << string_compose(_("Session: cannot send quarter-frame MTC message (%1)"), strerror (errno))
 			      << endmsg;
 			return -1;
 		}
@@ -840,7 +914,7 @@ Session::send_midi_time_code_for_cycle(nframes_t nframes)
 			<< ", qfm = " << next_quarter_frame_to_send
 			<< ", stamp = " << out_stamp
 			<< ", delta = " << _transport_frame + out_stamp - last_time << endl;*/
-		
+
 		// Increment quarter frame counter
 		next_quarter_frame_to_send++;
 
@@ -849,7 +923,7 @@ Session::send_midi_time_code_for_cycle(nframes_t nframes)
 			next_quarter_frame_to_send = 0;
 			// Increment smpte time twice
 			SMPTE::increment( transmitting_smpte_time );
-			SMPTE::increment( transmitting_smpte_time );        
+			SMPTE::increment( transmitting_smpte_time );
 			// Re-calculate timing of first quarter frame
 			//smpte_to_sample( transmitting_smpte_time, outbound_mtc_smpte_frame, true /* use_offset */, false );
 			outbound_mtc_smpte_frame += 8 * quarter_frame_duration;
@@ -880,7 +954,7 @@ Session::deliver_mmc (MIDI::MachineControl::Command cmd, nframes_t where)
 	mmc_buffer[nbytes++] = cmd;
 
 	// cerr << "delivering MMC, cmd = " << hex << (int) cmd << dec << endl;
-	
+
 	switch (cmd) {
 	case MachineControl::cmdLocate:
 		smpte_time_subframes (where, smpte);
@@ -925,7 +999,7 @@ Session::deliver_mmc (MIDI::MachineControl::Command cmd, nframes_t where)
 
 		if (_mmc_port->midimsg (mmc_buffer, nbytes, 0)) {
 			error << string_compose(_("MMC: cannot send command %1%2%3"), &hex, cmd, &dec) << endmsg;
-		} 
+		}
 	}
 }
 
@@ -959,7 +1033,7 @@ Session::mmc_step_timeout ()
 }
 
 /*---------------------------------------------------------------------------
-  MIDI THREAD 
+  MIDI THREAD
   ---------------------------------------------------------------------------*/
 
 int
@@ -995,9 +1069,9 @@ Session::terminate_midi_thread ()
 
 		MIDIRequest* request = new MIDIRequest;
 		void* status;
-		
+
 		request->type = MIDIRequest::Quit;
-		
+
 		midi_requests.write (&request, 1);
 		poke_midi_thread ();
 
@@ -1042,14 +1116,14 @@ Session::midi_thread_work ()
 
 	memset (&rtparam, 0, sizeof (rtparam));
 	rtparam.sched_priority = 9; /* XXX should be relative to audio (JACK) thread */
-	
+
 	if ((x = pthread_setschedparam (pthread_self(), SCHED_FIFO, &rtparam)) != 0) {
 		// do we care? not particularly.
-	} 
+	}
 
-	/* set up the port vector; 4 is the largest possible size for now */
+	/* set up the port vector; 5 is the largest possible size for now */
 
-	ports.assign (4, (MIDI::Port*) 0);
+	ports.assign (5, (MIDI::Port*) 0);
 
 	while (1) {
 
@@ -1078,6 +1152,15 @@ Session::midi_thread_work ()
 			nfds++;
 		}
 
+		cerr << "before handling midi clock port" << endl;
+		if (_midi_clock_port && (_midi_clock_port != _mmc_port || !Config->get_mmc_control()) && _midi_clock_port->selectable() >= 0) {
+			cerr << "inside handling midi clock port" << endl;
+			pfd[nfds].fd = _midi_clock_port->selectable();
+			pfd[nfds].events = POLLIN|POLLHUP|POLLERR;
+			ports[nfds] = _midi_clock_port;
+			nfds++;
+		}
+
 		/* if we are using MMC control, we obviously have to listen
 		   the relevant port.
 		*/
@@ -1088,7 +1171,7 @@ Session::midi_thread_work ()
 			ports[nfds] = _midi_port;
 			nfds++;
 		}
-		
+
 		if (!midi_timeouts.empty()) {
 			timeout = 100; /* 10msecs */
 		} else {
@@ -1121,7 +1204,7 @@ Session::midi_thread_work ()
 		if (pfd[0].revents & POLLIN) {
 
 			char foo[16];
-			
+
 			// cerr << "MIDI request FIFO ready\n";
 			fds_ready++;
 
@@ -1154,13 +1237,13 @@ Session::midi_thread_work ()
 					// cerr << "rebind\n";
 					restart = true;
 					break;
-						
+
 				case MIDIRequest::Quit:
 					delete request;
 					pthread_exit_pbd (0);
 					/*NOTREACHED*/
 					break;
-					
+
 				default:
 					break;
 				}
@@ -1169,7 +1252,7 @@ Session::midi_thread_work ()
 				delete request;
 			}
 
-		} 
+		}
 
 		if (restart) {
 			continue;
@@ -1182,7 +1265,7 @@ Session::midi_thread_work ()
 				// error << string_compose(_("Transport: error polling MIDI port %1 (revents =%2%3%4"), p, &hex, pfd[p].revents, &dec) << endmsg;
 				break;
 			}
-			
+
 			if (pfd[p].revents & POLLIN) {
 				fds_ready++;
 				ports[p]->parse ();
@@ -1190,19 +1273,19 @@ Session::midi_thread_work ()
 		}
 
 		/* timeout driven */
-		
+
 		if (fds_ready < 2 && timeout != -1) {
 
 			for (MidiTimeoutList::iterator i = midi_timeouts.begin(); i != midi_timeouts.end(); ) {
-				
+
 				MidiTimeoutList::iterator tmp;
 				tmp = i;
 				++tmp;
-				
+
 				if (!(*i)()) {
 					midi_timeouts.erase (i);
 				}
-				
+
 				i = tmp;
 			}
 		}
diff --git a/libs/ardour/session_transport.cc b/libs/ardour/session_transport.cc
index c86a868e56..61a741d0fb 100644
--- a/libs/ardour/session_transport.cc
+++ b/libs/ardour/session_transport.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 1999-2003 Paul Davis 
+    Copyright (C) 1999-2003 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -55,7 +55,7 @@ Session::request_input_change_handling ()
 	if (!(_state_of_the_state & (InitialConnecting|Deletion))) {
 		Event* ev = new Event (Event::InputConfigurationChange, Event::Add, Event::Immediate, 0, 0.0);
 		queue_event (ev);
-	} 
+	}
 }
 
 void
@@ -112,7 +112,7 @@ Session::force_locate (nframes_t target_frame, bool with_roll)
 void
 Session::request_play_loop (bool yn)
 {
-	Event* ev;	
+	Event* ev;
 	Location *location = _locations.auto_loop_location();
 
 	if (location == 0 && yn) {
@@ -135,7 +135,7 @@ void
 Session::realtime_stop (bool abort)
 {
 	/* assume that when we start, we'll be moving forwards */
-	
+
 	// FIXME: where should this really be? [DR]
 	//send_full_time_code();
 	deliver_mmc (MIDI::MachineControl::cmdStop, _transport_frame);
@@ -174,7 +174,7 @@ Session::realtime_stop (bool abort)
 	disable_record (true);
 
 	reset_slave_state ();
-		
+
 	_transport_speed = 0;
 
 	if (Config->get_use_video_sync()) {
@@ -221,7 +221,7 @@ Session::butler_transport_work ()
 		/* don't seek if locate will take care of that in non_realtime_stop() */
 
 		if (!(post_transport_work & PostTransportLocate)) {
-			
+
 			for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 				if (!(*i)->hidden()) {
 					if ((*i)->speed() != 1.0f || (*i)->speed() != -1.0f) {
@@ -239,7 +239,7 @@ Session::butler_transport_work ()
 			}
 		}
 	}
-	
+
 	if (post_transport_work & PostTransportLocate) {
 		non_realtime_locate ();
 	}
@@ -263,7 +263,7 @@ Session::butler_transport_work ()
 	if (post_transport_work & PostTransportAudition) {
 		non_realtime_set_audition ();
 	}
-	
+
 	g_atomic_int_dec_and_test (&butler_should_do_transport_work);
 }
 
@@ -293,7 +293,7 @@ Session::non_realtime_overwrite (int on_entry, bool& finished)
 	}
 }
 
-	
+
 void
 Session::non_realtime_locate ()
 {
@@ -317,7 +317,7 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 	saved = false;
 
 	boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
-	
+
 	for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 		if ((*i)->get_captured_frames () != 0) {
 			did_record = true;
@@ -326,7 +326,7 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 	}
 
 	/* stop and locate are merged here because they share a lot of common stuff */
-	
+
 	time (&xnow);
 	now = localtime (&xnow);
 
@@ -340,10 +340,10 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 
 	if (did_record) {
 		begin_reversible_command ("capture");
-		
+
 		Location* loc = _locations.end_location();
 		bool change_end = false;
-		
+
 		if (_transport_frame < loc->end()) {
 
 			/* stopped recording before current end */
@@ -353,15 +353,15 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 				/* first capture for this session, move end back to where we are */
 
 				change_end = true;
-			} 
+			}
 
 		} else if (_transport_frame > loc->end()) {
-			
+
 			/* stopped recording after the current end, extend it */
 
 			change_end = true;
 		}
-		
+
 		if (change_end) {
                         XMLNode &before = loc->get_state();
                         loc->set_end(_transport_frame);
@@ -376,7 +376,7 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 	for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 		(*i)->transport_stopped (*now, xnow, abort);
 	}
-	
+
 	boost::shared_ptr<RouteList> r = routes.reader ();
 
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
@@ -384,25 +384,25 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 			(*i)->set_pending_declick (0);
 		}
 	}
-	
+
 	if (did_record) {
 		commit_reversible_command ();
-	}	
-	
+	}
+
 	if (_engine.running()) {
 		update_latency_compensation (true, abort);
 	}
 
-	if ((Config->get_slave_source() == None && Config->get_auto_return()) || 
-	    (post_transport_work & PostTransportLocate) || 
+	if ((Config->get_slave_source() == None && Config->get_auto_return()) ||
+	    (post_transport_work & PostTransportLocate) ||
 	    (_requested_return_frame >= 0) ||
 	    synced_to_jack()) {
-		
+
 		if (pending_locate_flush) {
 			flush_all_inserts ();
 		}
-		
-		if (((Config->get_slave_source() == None && Config->get_auto_return()) || 
+
+		if (((Config->get_slave_source() == None && Config->get_auto_return()) ||
 		     synced_to_jack() ||
 		     _requested_return_frame >= 0) &&
 		    !(post_transport_work & PostTransportLocate)) {
@@ -421,12 +421,12 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 			if (synced_to_jack() && !play_loop) {
 				do_locate = true;
 			}
-			
+
 			if (do_locate) {
 				// cerr << "non-realtimestop: transport locate to " << _transport_frame << endl;
 				_engine.transport_locate (_transport_frame);
 			}
-		} 
+		}
 
 #ifndef LEAVE_TRANSPORT_UNADJUSTED
 	}
@@ -475,7 +475,7 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 		RecordStateChanged (); /* emit signal */
 #endif
 	}
-	
+
 	if ((post_transport_work & PostTransportLocate) && get_record_enabled()) {
 		/* capture start has been changed, so save pending state */
 		save_state ("", true);
@@ -485,7 +485,7 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
         /* always try to get rid of this */
 
         remove_pending_capture_state ();
-	
+
 	/* save the current state of things if appropriate */
 
 	if (did_record && !saved) {
@@ -496,11 +496,11 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 		DurationChanged (); /* EMIT SIGNAL */
 	}
 
-	if (post_transport_work & PostTransportStop) { 
+	if (post_transport_work & PostTransportStop) {
 		_play_range = false;
 
 		/* do not turn off autoloop on stop */
-		
+
 	}
 
         nframes_t tf = _transport_frame;
@@ -524,7 +524,7 @@ Session::check_declick_out ()
 	/* this is called after a process() iteration. if PendingDeclickOut was set,
 	   it means that we were waiting to declick the output (which has just been
 	   done) before doing something else. this is where we do that "something else".
-	   
+
 	   note: called from the audio thread.
 	*/
 
@@ -544,11 +544,11 @@ void
 Session::set_play_loop (bool yn)
 {
 	/* Called from event-handling context */
-	
+
 	if ((actively_recording() && yn) || _locations.auto_loop_location() == 0) {
 		return;
 	}
-	
+
 	set_dirty();
 
 	if (yn && Config->get_seamless_loop() && synced_to_jack()) {
@@ -558,12 +558,12 @@ Session::set_play_loop (bool yn)
 		return;
 	}
 
-	
+
 	if ((play_loop = yn)) {
 
 		Location *loc;
 
-		
+
 		if ((loc = _locations.auto_loop_location()) != 0) {
 
 			if (Config->get_seamless_loop()) {
@@ -584,9 +584,9 @@ Session::set_play_loop (bool yn)
 					}
 				}
 			}
-			
+
 			/* stick in the loop event */
-			
+
 			Event* event = new Event (Event::AutoLoop, Event::Replace, loc->end(), loc->start(), 0.0f);
 			merge_event (event);
 
@@ -614,7 +614,7 @@ Session::set_play_loop (bool yn)
 				(*i)->set_loop (0);
 			}
 		}
-		
+
 	}
 }
 
@@ -689,17 +689,17 @@ Session::locate (nframes_t target_frame, bool with_roll, bool with_flush, bool w
 			pending_locate_roll = with_roll;
 			pending_locate_flush = with_flush;
 			return;
-		} 
+		}
 	}
 
 	if (transport_rolling() && (!auto_play_legal || !Config->get_auto_play()) && !with_roll && !(synced_to_jack() && play_loop)) {
 		realtime_stop (false);
-	} 
+	}
 
 	if ( !with_loop || loop_changing) {
 
 		post_transport_work = PostTransportWork (post_transport_work | PostTransportLocate);
-		
+
 		if (with_roll) {
 			post_transport_work = PostTransportWork (post_transport_work | PostTransportRoll);
 		}
@@ -711,13 +711,13 @@ Session::locate (nframes_t target_frame, bool with_roll, bool with_flush, bool w
 		/* this is functionally what clear_clicks() does but with a tentative lock */
 
 		Glib::RWLock::WriterLock clickm (click_lock, Glib::TRY_LOCK);
-	
+
 		if (clickm.locked()) {
-			
+
 			for (Clicks::iterator i = clicks.begin(); i != clicks.end(); ++i) {
 				delete *i;
 			}
-		
+
 			clicks.clear ();
 		}
 	}
@@ -752,7 +752,7 @@ Session::locate (nframes_t target_frame, bool with_roll, bool with_flush, bool w
 	/* cancel looped playback if transport pos outside of loop range */
 	if (play_loop) {
 		Location* al = _locations.auto_loop_location();
-		
+
 		if (al && (_transport_frame < al->start() || _transport_frame > al->end())) {
 			// cancel looping directly, this is called from event handling context
 			set_play_loop (false);
@@ -762,7 +762,7 @@ Session::locate (nframes_t target_frame, bool with_roll, bool with_flush, bool w
 				// this is only necessary for seamless looping
 
 				boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
-				
+
 				for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 					if ((*i)->record_enabled ()) {
 						// tell it we've looped, so it can deal with the record state
@@ -774,7 +774,7 @@ Session::locate (nframes_t target_frame, bool with_roll, bool with_flush, bool w
 			TransportLooped(); // EMIT SIGNAL
 		}
 	}
-	
+
 	loop_changing = false;
 
 	_send_smpte_update = true;
@@ -808,7 +808,7 @@ Session::set_transport_speed (float speed, bool abort)
 			for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 				if ((*i)->record_enabled ()) {
 					//cerr << "switching to input" << __FILE__ << __LINE__ << endl << endl;
-					(*i)->monitor_input (true);	
+					(*i)->monitor_input (true);
 				}
 			}
 		}
@@ -818,7 +818,7 @@ Session::set_transport_speed (float speed, bool abort)
 		} else {
 			stop_transport (abort);
 		}
-		
+
 	} else if (transport_stopped() && speed == 1.0) {
 
 		/* we are stopped and we want to start rolling at speed 1 */
@@ -834,7 +834,7 @@ Session::set_transport_speed (float speed, bool abort)
 			for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 				if (Config->get_auto_input() && (*i)->record_enabled ()) {
 					//cerr << "switching from input" << __FILE__ << __LINE__ << endl << endl;
-					(*i)->monitor_input (false);	
+					(*i)->monitor_input (false);
 				}
 			}
 		}
@@ -868,7 +868,7 @@ Session::set_transport_speed (float speed, bool abort)
 		if (speed < 0.0f && _transport_frame == 0) {
 			return;
 		}
-		
+
 		clear_clicks ();
 
 		/* if we are reversing relative to the current speed, or relative to the speed
@@ -878,17 +878,17 @@ Session::set_transport_speed (float speed, bool abort)
 		if ((_transport_speed && speed * _transport_speed < 0.0f) || (_last_transport_speed * speed < 0.0f) || (_last_transport_speed == 0.0f && speed < 0.0f)) {
 			post_transport_work = PostTransportWork (post_transport_work | PostTransportReverse);
 		}
-		
+
 		_last_transport_speed = _transport_speed;
 		_transport_speed = speed;
-		
+
 		boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 		for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 			if ((*i)->realtime_set_speed ((*i)->speed(), true)) {
 				post_transport_work = PostTransportWork (post_transport_work | PostTransportSpeed);
 			}
 		}
-		
+
 		if (post_transport_work & (PostTransportSpeed|PostTransportReverse)) {
 			schedule_butler_transport_work ();
 		}
@@ -903,11 +903,11 @@ Session::stop_transport (bool abort)
 	if (_transport_speed == 0.0f) {
 		return;
 	}
-	
-	if (actively_recording() && !(transport_sub_state & StopPendingCapture) && 
-	    _worst_output_latency > current_block_size) 
+
+	if (actively_recording() && !(transport_sub_state & StopPendingCapture) &&
+	    _worst_output_latency > current_block_size)
 	{
-		
+
 		/* we need to capture the audio that has still not yet been received by the system
 		   at the time the stop is requested, so we have to roll past that time.
 
@@ -915,16 +915,16 @@ Session::stop_transport (bool abort)
 		   block before the actual end. we'll declick in the subsequent block,
 		   and then we'll really be stopped.
 		*/
-		
-		Event *ev = new Event (Event::StopOnce, Event::Replace, 
+
+		Event *ev = new Event (Event::StopOnce, Event::Replace,
 				       _transport_frame + _worst_output_latency - current_block_size,
 				       0, 0, abort);
-		
+
 		merge_event (ev);
 		transport_sub_state |= StopPendingCapture;
 		pending_abort = abort;
 		return;
-	} 
+	}
 
 
 	if ((transport_sub_state & PendingDeclickOut) == 0) {
@@ -944,7 +944,7 @@ Session::start_transport ()
 	_last_roll_location = _transport_frame;
 
 	/* if record status is Enabled, move it to Recording. if its
-	   already Recording, move it to Disabled. 
+	   already Recording, move it to Disabled.
 	*/
 
 	switch (record_status()) {
@@ -978,7 +978,7 @@ Session::actually_start_transport ()
 
 	transport_sub_state |= PendingDeclickIn;
 	_transport_speed = 1.0;
-	
+
 	boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 	for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 		(*i)->realtime_set_speed ((*i)->speed(), true);
@@ -1012,7 +1012,7 @@ Session::post_transport ()
 
 		if (((Config->get_slave_source() == None && (auto_play_legal && Config->get_auto_play())) && !_exporting) || (post_transport_work & PostTransportRoll)) {
 			start_transport ();
-			
+
 		} else {
 			transport_sub_state = 0;
 		}
@@ -1057,7 +1057,7 @@ Session::set_slave_source (SlaveSource src)
 // 	if (src == JACK && Config->get_jack_time_master()) {
 // 		return;
 // 	}
-	
+
 	if (_slave) {
 		delete _slave;
 		_slave = 0;
@@ -1071,7 +1071,7 @@ Session::set_slave_source (SlaveSource src)
 	case None:
 		stop_transport ();
 		break;
-		
+
 	case MTC:
 		if (_mtc_port) {
 			try {
@@ -1088,15 +1088,33 @@ Session::set_slave_source (SlaveSource src)
 		}
 		_desired_transport_speed = _transport_speed;
 		break;
-		
+
+	case MIDIClock:
+		if (_midi_clock_port) {
+			try {
+				_slave = new MIDIClock_Slave (*this, *_midi_clock_port, 24);
+			}
+
+			catch (failed_constructor& err) {
+				return;
+			}
+
+		} else {
+			error << _("No MIDI Clock port defined: MIDI Clock slaving is impossible.") << endmsg;
+			return;
+		}
+		_desired_transport_speed = _transport_speed;
+		break;
+
 	case JACK:
 		_slave = new JACK_Slave (_engine.jack());
 		_desired_transport_speed = _transport_speed;
 		break;
+
 	};
 
 	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()) {
@@ -1174,7 +1192,7 @@ Session::setup_auto_play ()
 	/* Called from event-processing context */
 
 	Event* ev;
-	
+
 	_clear_event_type (Event::RangeStop);
 	_clear_event_type (Event::RangeLocate);
 
@@ -1183,48 +1201,48 @@ Session::setup_auto_play ()
 	}
 
 	list<AudioRange>::size_type sz = current_audio_range.size();
-	
+
 	if (sz > 1) {
-		
-		list<AudioRange>::iterator i = current_audio_range.begin(); 
+
+		list<AudioRange>::iterator i = current_audio_range.begin();
 		list<AudioRange>::iterator next;
-		
+
 		while (i != current_audio_range.end()) {
-			
+
 			next = i;
 			++next;
-			
+
 			/* locating/stopping is subject to delays for declicking.
 			 */
-			
+
 			nframes_t requested_frame = (*i).end;
-			
+
 			if (requested_frame > current_block_size) {
 				requested_frame -= current_block_size;
 			} else {
 				requested_frame = 0;
 			}
-			
+
 			if (next == current_audio_range.end()) {
 				ev = new Event (Event::RangeStop, Event::Add, requested_frame, 0, 0.0f);
 			} else {
 				ev = new Event (Event::RangeLocate, Event::Add, requested_frame, (*next).start, 0.0f);
 			}
-			
+
 			merge_event (ev);
-			
+
 			i = next;
 		}
-		
+
 	} else if (sz == 1) {
-		
+
 		ev = new Event (Event::RangeStop, Event::Add, current_audio_range.front().end, 0, 0.0f);
 		merge_event (ev);
-		
-	} 
+
+	}
 
 	/* now start rolling at the right place */
-	
+
 	ev = new Event (Event::LocateRoll, Event::Add, Event::Immediate, current_audio_range.front().start, 0.0f, false);
 	merge_event (ev);
 }
@@ -1254,14 +1272,14 @@ Session::engine_halted ()
 	/* there will be no more calls to process(), so
 	   we'd better clean up for ourselves, right now.
 
-	   but first, make sure the butler is out of 
+	   but first, make sure the butler is out of
 	   the picture.
 	*/
 
 	g_atomic_int_set (&butler_should_do_transport_work, 0);
 	post_transport_work = PostTransportWork (0);
 	stop_butler ();
-	
+
 	realtime_stop (false);
 	non_realtime_stop (false, 0, ignored);
 	transport_sub_state = 0;
@@ -1282,7 +1300,7 @@ Session::xrun_recovery ()
 		*/
 
 		engine_halted();
-	} 
+	}
 }
 
 void
@@ -1299,15 +1317,15 @@ Session::update_latency_compensation (bool with_stop, bool abort)
 	boost::shared_ptr<RouteList> r = routes.reader ();
 
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-		
+
 		if (with_stop) {
-			(*i)->handle_transport_stopped (abort, (post_transport_work & PostTransportLocate), 
+			(*i)->handle_transport_stopped (abort, (post_transport_work & PostTransportLocate),
 							(!(post_transport_work & PostTransportLocate) || pending_locate_flush));
 		}
-		
+
 		nframes_t old_latency = (*i)->signal_latency ();
 		nframes_t track_latency = (*i)->update_total_latency ();
-		
+
 		if (old_latency != track_latency) {
 			(*i)->update_port_total_latencies ();
 			update_jack = true;
@@ -1316,7 +1334,7 @@ Session::update_latency_compensation (bool with_stop, bool abort)
  		if (!(*i)->is_hidden() && ((*i)->active())) {
 			_worst_track_latency = max (_worst_track_latency, track_latency);
 		}
-	} 
+	}
 
 	if (update_jack) {
 		_engine.update_total_latencies ();
@@ -1330,7 +1348,7 @@ Session::update_latency_compensation (bool with_stop, bool abort)
 
 	/* reflect any changes in latencies into capture offsets
 	*/
-	
+
 	boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 
 	for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
diff --git a/libs/ardour/utils.cc b/libs/ardour/utils.cc
index f30f568f9d..58443bd005 100644
--- a/libs/ardour/utils.cc
+++ b/libs/ardour/utils.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2000-2003 Paul Davis 
+    Copyright (C) 2000-2003 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -50,7 +50,7 @@ using namespace std;
 using namespace PBD;
 using Glib::ustring;
 
-ustring 
+ustring
 legalize_for_path (ustring str)
 {
 	ustring::size_type pos;
@@ -97,7 +97,7 @@ string bump_name_once(std::string name)
 			char buf[32];
 
 			snprintf (buf, sizeof(buf), "%ld", version+1);
-		
+
 			newname  = name.substr (0, period+1);
 			newname += buf;
 		}
@@ -140,7 +140,7 @@ cmp_nocase (const string& s, const string& s2)
 {
 	string::const_iterator p = s.begin();
 	string::const_iterator p2 = s2.begin();
-	
+
 	while (p != s.end() && p2 != s2.end()) {
 		if (toupper(*p) != toupper(*p2)) {
 			return (toupper(*p) < toupper(*p2)) ? -1 : 1;
@@ -148,7 +148,7 @@ cmp_nocase (const string& s, const string& s2)
 		++p;
 		++p2;
 	}
-	
+
 	return (s2.size() == s.size()) ? 0 : (s.size() < s2.size()) ? -1 : 1;
 }
 
@@ -171,12 +171,12 @@ region_name_from_path (ustring path, bool strip_channels, bool add_channel_suffi
 	if (strip_channels) {
 
 		/* remove any "?R", "?L" or "?[a-z]" channel identifier */
-		
+
 		ustring::size_type len = path.length();
-		
-		if (len > 3 && (path[len-2] == '%' || path[len-2] == '?' || path[len-2] == '.') && 
+
+		if (len > 3 && (path[len-2] == '%' || path[len-2] == '?' || path[len-2] == '.') &&
 		    (path[len-1] == 'R' || path[len-1] == 'L' || (islower (path[len-1])))) {
-			
+
 			path = path.substr (0, path.length() - 2);
 		}
 	}
@@ -184,7 +184,7 @@ region_name_from_path (ustring path, bool strip_channels, bool add_channel_suffi
 	if (add_channel_suffix) {
 
 		path += '%';
-		
+
 		if (total > 2) {
 			path += (char) ('a' + this_one);
 		} else {
@@ -193,7 +193,7 @@ region_name_from_path (ustring path, bool strip_channels, bool add_channel_suffi
 	}
 
 	return path;
-}	
+}
 
 bool
 path_is_paired (ustring path, ustring& pair_base)
@@ -207,7 +207,7 @@ path_is_paired (ustring path, ustring& pair_base)
 	}
 
  	/* remove filename suffixes etc. */
-	
+
 	if ((pos = path.find_last_of ('.')) != string::npos) {
 		path = path.substr (0, pos);
 	}
@@ -216,13 +216,13 @@ path_is_paired (ustring path, ustring& pair_base)
 
 	/* look for possible channel identifier: "?R", "%R", ".L" etc. */
 
-	if (len > 3 && (path[len-2] == '%' || path[len-2] == '?' || path[len-2] == '.') && 
+	if (len > 3 && (path[len-2] == '%' || path[len-2] == '?' || path[len-2] == '.') &&
 	    (path[len-1] == 'R' || path[len-1] == 'L' || (islower (path[len-1])))) {
-		
+
 		pair_base = path.substr (0, len-2);
 		return true;
 
-	} 
+	}
 
 	return false;
 }
@@ -253,20 +253,20 @@ path_expand (ustring path)
 	wordfree (&expansion);
 	return ret;
 
-#else 
+#else
 	return path;
 #endif
 }
 
 #if defined(HAVE_COREAUDIO) || defined(HAVE_AUDIOUNITS)
-string 
+string
 CFStringRefToStdString(CFStringRef stringRef)
 {
-	CFIndex size = 
-		CFStringGetMaximumSizeForEncoding(CFStringGetLength(stringRef) , 
+	CFIndex size =
+		CFStringGetMaximumSizeForEncoding(CFStringGetLength(stringRef) ,
 		kCFStringEncodingUTF8);
 	    char *buf = new char[size];
-	
+
 	std::string result;
 
 	if(CFStringGetCString(stringRef, buf, size, kCFStringEncodingUTF8)) {
@@ -285,11 +285,11 @@ compute_equal_power_fades (nframes_t nframes, float* in, float* out)
 	step = 1.0/nframes;
 
 	in[0] = 0.0f;
-	
+
 	for (nframes_t i = 1; i < nframes - 1; ++i) {
 		in[i] = in[i-1] + step;
 	}
-	
+
 	in[nframes-1] = 1.0;
 
 	const float pan_law_attenuation = -3.0f;
@@ -340,11 +340,15 @@ string_to_slave_source (string str)
 	if (str == _("Internal")) {
 		return None;
 	}
-	
+
 	if (str == _("MTC")) {
 		return MTC;
 	}
 
+	if (str == _("MIDI Clock")) {
+		return MIDIClock;
+	}
+
 	if (str == _("JACK")) {
 		return JACK;
 	}
@@ -363,11 +367,14 @@ slave_source_to_string (SlaveSource src)
 
 	case MTC:
 		return _("MTC");
-		
+
+	case MIDIClock:
+		return _("MIDI Clock");
+
 	default:
 	case None:
 		return _("Internal");
-		
+
 	}
 }
 
@@ -449,7 +456,7 @@ meter_hold_to_float (MeterHold hold)
 	}
 }
 
-AutoState 
+AutoState
 ARDOUR::string_to_auto_state (std::string str)
 {
 	if (str == X_("Off")) {
@@ -467,7 +474,7 @@ ARDOUR::string_to_auto_state (std::string str)
 	return Touch;
 }
 
-string 
+string
 ARDOUR::auto_state_to_string (AutoState as)
 {
 	/* to be used only for XML serialization, no i18n done */
@@ -491,7 +498,7 @@ ARDOUR::auto_state_to_string (AutoState as)
 	return "";
 }
 
-AutoStyle 
+AutoStyle
 ARDOUR::string_to_auto_style (std::string str)
 {
 	if (str == X_("Absolute")) {
@@ -505,7 +512,7 @@ ARDOUR::string_to_auto_style (std::string str)
 	return Trim;
 }
 
-string 
+string
 ARDOUR::auto_style_to_string (AutoStyle as)
 {
 	/* to be used only for XML serialization, no i18n done */