first pass (ok, third really) at internal send+return - audio routing inside ardour without JACK. lots still to do, but at least the obvious works

git-svn-id: svn://localhost/ardour2/branches/3.0@5202 d708f5d6-7413-0410-9779-e7cbd77b26cf

38 files changed, 972 insertions, 351 deletions

diff --git a/libs/ardour/ardour/ardour.h b/libs/ardour/ardour/ardour.h
index 630bde675c..892df2eb50 100644
--- a/libs/ardour/ardour/ardour.h
+++ b/libs/ardour/ardour/ardour.h
@@ -47,6 +47,7 @@ namespace ARDOUR {
 
 	int init (bool with_vst, bool try_optimization);
 	int cleanup ();
+	bool no_auto_connect ();
 
 	std::string get_ardour_revision ();
 
diff --git a/libs/ardour/ardour/audio_buffer.h b/libs/ardour/ardour/audio_buffer.h
index ca1b36e0b1..be1af03061 100644
--- a/libs/ardour/ardour/audio_buffer.h
+++ b/libs/ardour/ardour/audio_buffer.h
@@ -56,6 +56,13 @@ public:
 		}
 		_written = true;
 	}
+
+	/** Acumulate (add) @a len frames @a src starting at @a src_offset into self starting at @ dst_offset*/
+	void merge_from (const Buffer& src, nframes_t len, nframes_t dst_offset = 0, nframes_t src_offset = 0) {
+		const AudioBuffer* ab = dynamic_cast<const AudioBuffer*>(&src);
+		assert (ab);
+		accumulate_from (*ab, len, dst_offset, src_offset);
+	}
 	
 	/** Acumulate (add) @a len frames @a src starting at @a src_offset into self starting at @ dst_offset*/
 	void accumulate_from (const AudioBuffer& src, nframes_t len, nframes_t dst_offset = 0, nframes_t src_offset = 0) {
diff --git a/libs/ardour/ardour/buffer.h b/libs/ardour/ardour/buffer.h
index da75556877..8ed054923b 100644
--- a/libs/ardour/ardour/buffer.h
+++ b/libs/ardour/ardour/buffer.h
@@ -76,6 +76,7 @@ public:
 	virtual void clear() { silence(_capacity, 0); }
 	
 	virtual void read_from (const Buffer& src, nframes_t len, nframes_t dst_offset = 0, nframes_t src_offset = 0) = 0;
+	virtual void merge_from (const Buffer& src, nframes_t len, nframes_t dst_offset = 0, nframes_t src_offset = 0) = 0;
 
   protected:
 	Buffer(DataType type, size_t capacity)
diff --git a/libs/ardour/ardour/buffer_set.h b/libs/ardour/ardour/buffer_set.h
index 3f10929fe8..ecd4e4ab72 100644
--- a/libs/ardour/ardour/buffer_set.h
+++ b/libs/ardour/ardour/buffer_set.h
@@ -68,6 +68,7 @@ public:
 
 	void is_silent(bool yn) { _is_silent = yn; }
 	bool is_silent() const  { return _is_silent; }
+	void silence (nframes_t nframes, nframes_t offset);
 
 	void set_count(const ChanCount& count) { assert(count <= _available); _count = count; }
 	
@@ -94,6 +95,7 @@ public:
 #endif
 
 	void read_from(BufferSet& in, nframes_t nframes);
+	void merge_from(BufferSet& in, nframes_t nframes);
 
 	// ITERATORS
 	// FIXME: possible to combine these?  templates?
diff --git a/libs/ardour/ardour/delivery.h b/libs/ardour/ardour/delivery.h
index c875f23fcc..32ecc98215 100644
--- a/libs/ardour/ardour/delivery.h
+++ b/libs/ardour/ardour/delivery.h
@@ -40,7 +40,13 @@ public:
 		Main   = 0x8
 	};
 
+	/* Delivery to an existing output */
+
 	Delivery (Session& s, boost::shared_ptr<IO> io, boost::shared_ptr<MuteMaster> mm, const std::string& name, Role);
+	Delivery (Session& s, boost::shared_ptr<IO> io, boost::shared_ptr<MuteMaster> mm, const XMLNode&);
+
+	/* Delivery to a new output owned by this object */
+
 	Delivery (Session& s, boost::shared_ptr<MuteMaster> mm, const std::string& name, Role);
 	Delivery (Session&, boost::shared_ptr<MuteMaster> mm, const XMLNode&);
 
diff --git a/libs/ardour/ardour/internal_return.h b/libs/ardour/ardour/internal_return.h
new file mode 100644
index 0000000000..6aa8bfe7b4
--- /dev/null
+++ b/libs/ardour/ardour/internal_return.h
@@ -0,0 +1,60 @@
+/*
+    Copyright (C) 2009 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
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef __ardour_internal_return_h__
+#define __ardour_internal_return_h__
+
+#include <sigc++/signal.h>
+
+#include "ardour/ardour.h"
+#include "ardour/return.h"
+#include "ardour/buffer_set.h"
+
+namespace ARDOUR {
+
+class InternalReturn : public Return
+{
+  public:	
+	InternalReturn (Session&);
+	InternalReturn (Session&, const XMLNode&);
+
+	XMLNode& state(bool full);
+	XMLNode& get_state(void);
+	int set_state(const XMLNode& node);
+
+	void run (BufferSet& bufs, sframes_t start_frame, sframes_t end_frame, nframes_t nframes);
+	bool configure_io (ChanCount in, ChanCount out);
+	bool can_support_io_configuration (const ChanCount& in, ChanCount& out) const;
+	void set_block_size (nframes_t);
+
+	BufferSet* get_buffers();
+	void release_buffers();
+
+	static sigc::signal<void,nframes_t> CycleStart;
+
+  private:
+	BufferSet buffers;
+	uint32_t  user_count;
+	void allocate_buffers (nframes_t);
+	void cycle_start (nframes_t);
+};
+
+} // namespace ARDOUR
+
+#endif /* __ardour_internal_return_h__ */
diff --git a/libs/ardour/ardour/internal_send.h b/libs/ardour/ardour/internal_send.h
new file mode 100644
index 0000000000..0bbb75d685
--- /dev/null
+++ b/libs/ardour/ardour/internal_send.h
@@ -0,0 +1,57 @@
+/*
+    Copyright (C) 2009 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
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef __ardour_internal_send_h__
+#define __ardour_internal_send_h__
+
+#include "ardour/ardour.h"
+#include "ardour/send.h"
+
+namespace ARDOUR {
+
+class InternalSend : public Send
+{
+  public:	
+	InternalSend (Session&, boost::shared_ptr<MuteMaster>, boost::shared_ptr<Route> send_to);
+	InternalSend (Session&, boost::shared_ptr<MuteMaster>, const XMLNode&);
+	virtual ~InternalSend ();
+
+	XMLNode& state(bool full);
+	XMLNode& get_state(void);
+	int set_state(const XMLNode& node);
+	
+	void run (BufferSet& bufs, sframes_t start_frame, sframes_t end_frame, nframes_t nframes);
+	bool feeds (boost::shared_ptr<Route> other) const;
+	bool can_support_io_configuration (const ChanCount& in, ChanCount& out) const;
+
+	boost::shared_ptr<Route> target_route() const { return _send_to; }
+
+  private:
+	BufferSet* target;
+	boost::shared_ptr<Route> _send_to;
+	PBD::ID _send_to_id;
+	sigc::connection connect_c;
+
+	void send_to_going_away ();
+	int  connect_when_legal ();
+};
+
+} // namespace ARDOUR
+
+#endif /* __ardour_send_h__ */
diff --git a/libs/ardour/ardour/io_processor.h b/libs/ardour/ardour/io_processor.h
index 14d88d6b44..430f54d46d 100644
--- a/libs/ardour/ardour/io_processor.h
+++ b/libs/ardour/ardour/io_processor.h
@@ -37,6 +37,7 @@ namespace ARDOUR {
 
 class Session;
 class IO;
+class Route;
 
 /** A mixer strip element (Processor) with 1 or 2 IO elements.
  */
@@ -66,6 +67,8 @@ class IOProcessor : public Processor
 	
 	void silence (nframes_t nframes);
 
+	virtual bool feeds (boost::shared_ptr<Route> other) const;
+
 	sigc::signal<void,IOProcessor*,bool>     AutomationPlaybackChanged;
 	sigc::signal<void,IOProcessor*,uint32_t> AutomationChanged;
 	
diff --git a/libs/ardour/ardour/meter.h b/libs/ardour/ardour/meter.h
index 57afcc39ca..414b559de0 100644
--- a/libs/ardour/ardour/meter.h
+++ b/libs/ardour/ardour/meter.h
@@ -51,6 +51,7 @@ class Metering {
 class PeakMeter : public Processor {
 public:
 	PeakMeter(Session& s) : Processor(s, "Meter") {}
+	PeakMeter(Session&s, const XMLNode& node);
 
 	void meter();
 
diff --git a/libs/ardour/ardour/midi_buffer.h b/libs/ardour/ardour/midi_buffer.h
index 64417cae26..4e27e33235 100644
--- a/libs/ardour/ardour/midi_buffer.h
+++ b/libs/ardour/ardour/midi_buffer.h
@@ -39,6 +39,7 @@ public:
 
 	void silence (nframes_t nframes, nframes_t offset = 0);
 	void read_from (const Buffer& src, nframes_t nframes, nframes_t dst_offset = 0, nframes_t src_offset = 0);
+	void merge_from (const Buffer& src, nframes_t nframes, nframes_t dst_offset = 0, nframes_t src_offset = 0);
 	
 	void copy(const MidiBuffer& copy);
 
diff --git a/libs/ardour/ardour/processor.h b/libs/ardour/ardour/processor.h
index 06fcb81ce7..f91e9a6863 100644
--- a/libs/ardour/ardour/processor.h
+++ b/libs/ardour/ardour/processor.h
@@ -50,7 +50,8 @@ class Processor : public SessionObject, public AutomatableControls, public Laten
 	static const std::string state_node_name;
 
 	Processor(Session&, const std::string& name);
-	
+	Processor(Session&, const XMLNode& node);
+
 	virtual ~Processor() { }
 	
 	virtual bool visible() const { return true; }
diff --git a/libs/ardour/ardour/rc_configuration_vars.h b/libs/ardour/ardour/rc_configuration_vars.h
index 7387e5d001..3f063f4692 100644
--- a/libs/ardour/ardour/rc_configuration_vars.h
+++ b/libs/ardour/ardour/rc_configuration_vars.h
@@ -19,7 +19,7 @@
 
 /* IO connection */
 
-CONFIG_VARIABLE (bool, auto_connect_master, "auto-connect-master", true)
+CONFIG_VARIABLE (bool, auto_connect_standard_busses, "auto-connect-standard-busses", true)
 CONFIG_VARIABLE (AutoConnectOption, output_auto_connect, "output-auto-connect", AutoConnectOption (0))
 CONFIG_VARIABLE (AutoConnectOption, input_auto_connect, "input-auto-connect", AutoConnectOption (0))
 
diff --git a/libs/ardour/ardour/region.h b/libs/ardour/ardour/region.h
index aa768e269f..d2cc252d61 100644
--- a/libs/ardour/ardour/region.h
+++ b/libs/ardour/ardour/region.h
@@ -74,7 +74,7 @@ class Region
 		LeftOfSplit = 0x4000,
 		RightOfSplit = 0x8000,
 		Hidden = 0x10000,
-		DoNotSaveState = 0x20000,
+		DoNotSendPropertyChanges = 0x20000,
 		PositionLocked = 0x40000,
 		//
 		range_guarantoor = USHRT_MAX
@@ -97,6 +97,8 @@ class Region
 
 	sigc::signal<void,Change> StateChanged;
 	static sigc::signal<void,boost::shared_ptr<ARDOUR::Region> > RegionPropertyChanged;
+	void unlock_property_changes () { _flags = Flag (_flags & ~DoNotSendPropertyChanges); }
+	void block_property_changes () { _flags = Flag (_flags | DoNotSendPropertyChanges); }
 
 	virtual ~Region();
 
@@ -160,8 +162,6 @@ class Region
 	void set_position_lock_style (PositionLockStyle ps);
 	void recompute_position_from_lock_style ();
 
-	virtual bool should_save_state () const { return !(_flags & DoNotSaveState); };
-
 	void freeze ();
 	void thaw (const std::string& why);
 
diff --git a/libs/ardour/ardour/return.h b/libs/ardour/ardour/return.h
index 3f75cc57b7..8f8a84f321 100644
--- a/libs/ardour/ardour/return.h
+++ b/libs/ardour/ardour/return.h
@@ -38,8 +38,8 @@ class PeakMeter;
 class Return : public IOProcessor 
 {
 public:	
-	Return (Session&);
-	Return (Session&, const XMLNode&);
+	Return (Session&, bool internal = false);
+	Return (Session&, const XMLNode&, bool internal = false);
 	virtual ~Return ();
 	
 	uint32_t bit_slot() const { return _bitslot; }
diff --git a/libs/ardour/ardour/route.h b/libs/ardour/ardour/route.h
index 2a3580b187..339f18ef3f 100644
--- a/libs/ardour/ardour/route.h
+++ b/libs/ardour/ardour/route.h
@@ -52,6 +52,7 @@ class Panner;
 class Processor;
 class RouteGroup;
 class Send;
+class InternalReturn;
 
 class Route : public SessionObject, public AutomatableControls
 {
@@ -183,18 +184,17 @@ class Route : public SessionObject, public AutomatableControls
 		}
 	}
 
-	ProcessorList::iterator prefader_iterator();
-	
 	ChanCount max_processor_streams () const { return processor_max_streams; }
-	ChanCount pre_fader_streams() const;
 
 	/* special processors */
 
-	boost::shared_ptr<Delivery> control_outs() const { return _control_outs; }
-	boost::shared_ptr<Delivery> main_outs() const { return _main_outs; }
-	
-	boost::shared_ptr<Send> send_for (boost::shared_ptr<const IO> target) const;
-	
+	boost::shared_ptr<Delivery>       control_outs() const { return _control_outs; }
+	boost::shared_ptr<Delivery>       main_outs() const { return _main_outs; }
+	boost::shared_ptr<InternalReturn> internal_return() const { return _intreturn; }
+	boost::shared_ptr<Send>           internal_send_for (boost::shared_ptr<const Route> target) const;
+	BufferSet* get_return_buffer () const;
+	void release_return_buffer () const;
+
 	/** A record of the stream configuration at some point in the processor list.
 	 * Used to return where and why an processor list configuration request failed.
 	 */
@@ -262,10 +262,10 @@ class Route : public SessionObject, public AutomatableControls
 
 	sigc::signal<void,void*> SelectedChanged;
 	
-	int listen_via (boost::shared_ptr<IO>, const std::string& name);
-	void drop_listen (boost::shared_ptr<IO>);
+	int listen_via (boost::shared_ptr<Route>, const std::string& name);
+	void drop_listen (boost::shared_ptr<Route>);
 
-	bool feeds (boost::shared_ptr<IO>);
+	bool feeds (boost::shared_ptr<Route>);
 	std::set<boost::shared_ptr<Route> > fed_by;
 
 	/* Controls (not all directly owned by the Route */
@@ -341,6 +341,7 @@ class Route : public SessionObject, public AutomatableControls
 	mutable Glib::RWLock   _processor_lock;
 	boost::shared_ptr<Delivery> _main_outs;
 	boost::shared_ptr<Delivery> _control_outs; // XXX to be removed/generalized by listen points
+	boost::shared_ptr<InternalReturn> _intreturn;
 
 	Flag           _flags;
 	int            _pending_declick;
@@ -381,8 +382,6 @@ class Route : public SessionObject, public AutomatableControls
 	
 	virtual int  _set_state (const XMLNode&, bool call_base);
 
-	boost::shared_ptr<Delivery> add_listener (boost::shared_ptr<IO>, const std::string&);
-
 	boost::shared_ptr<Amp>       _amp;
 	boost::shared_ptr<PeakMeter> _meter;
 	sigc::connection _meter_connection;
diff --git a/libs/ardour/ardour/send.h b/libs/ardour/ardour/send.h
index 3a0eae21e5..37d56e2abd 100644
--- a/libs/ardour/ardour/send.h
+++ b/libs/ardour/ardour/send.h
@@ -37,8 +37,8 @@ class Amp;
 class Send : public Delivery
 {
   public:	
-	Send (Session&, boost::shared_ptr<MuteMaster>);
-	Send (Session&, boost::shared_ptr<MuteMaster>, const XMLNode&);
+	Send (Session&, boost::shared_ptr<MuteMaster>, bool internal = false);
+	Send (Session&, boost::shared_ptr<MuteMaster>, const XMLNode&, bool internal = false);
 	virtual ~Send ();
 
 	uint32_t bit_slot() const { return _bitslot; }
diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 2e161ff776..e970d6e9e4 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -747,12 +747,6 @@ class Session : public PBD::StatefulDestructible, public boost::noncopyable
 	boost::shared_ptr<Route> control_out() const { return _control_out; }
 	boost::shared_ptr<Route> 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) {
 		_disable_all_loaded_plugins = yn;
 	}
@@ -1558,16 +1552,9 @@ class Session : public PBD::StatefulDestructible, public boost::noncopyable
 
 	/* INSERT AND SEND MANAGEMENT */
 
-	std::list<PortInsert *>              _port_inserts;
-	std::list<PluginInsert *>            _plugin_inserts;
-	std::list<Send *>                    _sends;
-	std::list<Return *>                  _returns;
 	boost::dynamic_bitset<uint32_t> send_bitset;
 	boost::dynamic_bitset<uint32_t> return_bitset;
 	boost::dynamic_bitset<uint32_t> insert_bitset;
-	uint32_t                        send_cnt;
-	uint32_t                        insert_cnt;
-
 
 	void add_processor (Processor *);
 	void remove_processor (Processor *);
diff --git a/libs/ardour/audioengine.cc b/libs/ardour/audioengine.cc
index 4e2d97f718..4143cb109a 100644
--- a/libs/ardour/audioengine.cc
+++ b/libs/ardour/audioengine.cc
@@ -31,23 +31,23 @@
 
 #include "midi++/jack.h"
 
+#include "ardour/amp.h"
+#include "ardour/audio_port.h"
 #include "ardour/audioengine.h"
 #include "ardour/buffer.h"
-#include "ardour/delivery.h"
-#include "ardour/port.h"
-#include "ardour/audio_port.h"
-#include "ardour/midi_port.h"
-#include "ardour/meter.h"
-#include "ardour/session.h"
+#include "ardour/buffer_set.h"
 #include "ardour/cycle_timer.h"
-#include "ardour/utils.h"
+#include "ardour/delivery.h"
 #include "ardour/event_type_map.h"
+#include "ardour/internal_return.h"
 #include "ardour/io.h"
-#include "ardour/amp.h"
+#include "ardour/meter.h"
+#include "ardour/midi_port.h"
+#include "ardour/port.h"
 #include "ardour/port_set.h"
-#include "ardour/buffer_set.h"
-
+#include "ardour/session.h"
 #include "ardour/timestamps.h"
+#include "ardour/utils.h"
 
 #include "i18n.h"
 
@@ -364,6 +364,7 @@ AudioEngine::process_callback (nframes_t nframes)
 
 	Delivery::CycleStart (nframes);
 	Port::set_port_offset (0);
+	InternalReturn::CycleStart (nframes);
 
 	/* tell all Ports that we're starting a new cycle */
 
@@ -822,10 +823,15 @@ AudioEngine::frames_per_cycle ()
 Port *
 AudioEngine::get_port_by_name (const string& portname)
 {
-	assert (portname.find_first_of (':') != string::npos);
+	string s;
+	if (portname.find_first_of (':') == string::npos) {
+		s = make_port_name_non_relative (portname);
+	} else {
+		s = portname;
+	}
 	
 	Glib::Mutex::Lock lm (_process_lock);
-	return get_port_by_name_locked (portname);
+	return get_port_by_name_locked (s);
 }
 
 Port *
diff --git a/libs/ardour/audioregion.cc b/libs/ardour/audioregion.cc
index 25948e595c..5743bae935 100644
--- a/libs/ardour/audioregion.cc
+++ b/libs/ardour/audioregion.cc
@@ -655,6 +655,14 @@ AudioRegion::set_live_state (const XMLNode& node, Change& what_changed, bool sen
 		_flags = Flag (_flags & ~Region::RightOfSplit);
 	}
 
+	/* leave this flag setting in place, no matter what */
+
+	if ((old_flags & DoNotSendPropertyChanges)) {
+		_flags = Flag (_flags | DoNotSendPropertyChanges);
+	}
+
+	/* find out if any flags changed that we signal about */
+
 	if ((old_flags ^ _flags) & Muted) {
 		what_changed = Change (what_changed|MuteChanged);
 	}
diff --git a/libs/ardour/buffer_set.cc b/libs/ardour/buffer_set.cc
index 005a4dae65..319444e1b9 100644
--- a/libs/ardour/buffer_set.cc
+++ b/libs/ardour/buffer_set.cc
@@ -225,5 +225,32 @@ BufferSet::read_from (BufferSet& in, nframes_t nframes)
 	set_count(in.count());
 }
 
+// FIXME: make 'in' const
+void
+BufferSet::merge_from (BufferSet& in, nframes_t nframes)
+{
+	assert(available() >= in.count());
+
+	/* merge all input buffers into out existing buffers */
+	for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
+		BufferSet::iterator o = begin(*t);
+		for (BufferSet::iterator i = in.begin(*t); i != in.end(*t); ++i, ++o) {
+			o->merge_from (*i, nframes);
+		}
+	}
+
+	set_count (in.count());
+}
+
+void
+BufferSet::silence (nframes_t nframes, nframes_t offset)
+{
+	for (std::vector<BufferVec>::iterator i = _buffers.begin(); i != _buffers.end(); ++i) {
+		for (BufferVec::iterator b = i->begin(); b != i->end(); ++b) {
+			(*b)->silence (nframes, offset);
+		}
+	}
+}
+
 } // namespace ARDOUR
 
diff --git a/libs/ardour/delivery.cc b/libs/ardour/delivery.cc
index 0a49a47a7f..a4a76c37ae 100644
--- a/libs/ardour/delivery.cc
+++ b/libs/ardour/delivery.cc
@@ -47,7 +47,7 @@ bool                         Delivery::panners_legal = false;
 /* deliver to an existing IO object */
 
 Delivery::Delivery (Session& s, boost::shared_ptr<IO> io, boost::shared_ptr<MuteMaster> mm, const string& name, Role r)
-	: IOProcessor(s, boost::shared_ptr<IO>(), io, name)
+	: IOProcessor(s, boost::shared_ptr<IO>(), (r == Listen ? boost::shared_ptr<IO>() : io), name)
 	, _role (r)
 	, _output_buffers (new BufferSet())
 	, _solo_level (0)
@@ -58,13 +58,15 @@ Delivery::Delivery (Session& s, boost::shared_ptr<IO> io, boost::shared_ptr<Mute
 	_current_gain = 1.0;
 	_panner = boost::shared_ptr<Panner>(new Panner (_name, _session));
 	
-	_output->changed.connect (mem_fun (*this, &Delivery::output_changed));
+	if (_output) {
+		_output->changed.connect (mem_fun (*this, &Delivery::output_changed));
+	}
 }
 
 /* deliver to a new IO object */
 
 Delivery::Delivery (Session& s, boost::shared_ptr<MuteMaster> mm, const string& name, Role r)
-	: IOProcessor(s, false, true, name)
+	: IOProcessor(s, false, (r == Listen ? false : true), name)
 	, _role (r)
 	, _output_buffers (new BufferSet())
 	, _solo_level (0)
@@ -75,7 +77,9 @@ Delivery::Delivery (Session& s, boost::shared_ptr<MuteMaster> mm, const string&
 	_current_gain = 1.0;
 	_panner = boost::shared_ptr<Panner>(new Panner (_name, _session));
 
-	_output->changed.connect (mem_fun (*this, &Delivery::output_changed));
+	if (_output) {
+		_output->changed.connect (mem_fun (*this, &Delivery::output_changed));
+	}
 }
 
 /* deliver to a new IO object, reconstruct from XML */
@@ -96,7 +100,32 @@ Delivery::Delivery (Session& s, boost::shared_ptr<MuteMaster> mm, const XMLNode&
 		throw failed_constructor ();
 	}
 
-	_output->changed.connect (mem_fun (*this, &Delivery::output_changed));
+	if (_output) {
+		_output->changed.connect (mem_fun (*this, &Delivery::output_changed));
+	}
+}
+
+/* deliver to an existing IO object, reconstruct from XML */
+
+Delivery::Delivery (Session& s, boost::shared_ptr<IO> out, boost::shared_ptr<MuteMaster> mm, const XMLNode& node)
+	: IOProcessor (s, boost::shared_ptr<IO>(), out, "reset")
+	, _role (Role (0))
+	, _output_buffers (new BufferSet())
+	, _solo_level (0)
+	, _solo_isolated (false)
+	, _mute_master (mm)
+{
+	_output_offset = 0;
+	_current_gain = 1.0;
+	_panner = boost::shared_ptr<Panner>(new Panner (_name, _session));
+
+	if (set_state (node)) {
+		throw failed_constructor ();
+	}
+
+	if (_output) {
+		_output->changed.connect (mem_fun (*this, &Delivery::output_changed));
+	}
 }
 
 void
@@ -265,7 +294,16 @@ Delivery::reset_panner ()
 {
 	if (panners_legal) {
 		if (!no_panner_reset) {
-			_panner->reset (_output->n_ports().n_audio(), pans_required());
+
+			uint32_t ntargets;
+			
+			if (_output) {
+				ntargets = _output->n_ports().n_audio();
+			} else {
+				ntargets = _configured_output.n_audio();
+			}
+
+			_panner->reset (ntargets, pans_required());
 		}
 	} else {
 		panner_legal_c.disconnect ();
@@ -276,7 +314,15 @@ Delivery::reset_panner ()
 int
 Delivery::panners_became_legal ()
 {
-	_panner->reset (_output->n_ports().n_audio(), pans_required());
+	uint32_t ntargets;
+
+	if (_output) {
+		ntargets = _output->n_ports().n_audio();
+	} else {
+		ntargets = _configured_output.n_audio();
+	}
+
+	_panner->reset (ntargets, pans_required());
 	_panner->load (); // automation
 	panner_legal_c.disconnect ();
 	return 0;
@@ -441,3 +487,4 @@ Delivery::output_changed (IOChange change, void* src)
 		reset_panner ();
 	}
 }
+
diff --git a/libs/ardour/enums.cc b/libs/ardour/enums.cc
index 6e98fdf5a7..43fb4e4014 100644
--- a/libs/ardour/enums.cc
+++ b/libs/ardour/enums.cc
@@ -396,7 +396,7 @@ setup_enum_writer ()
 	REGISTER_CLASS_ENUM (Region, LeftOfSplit);
 	REGISTER_CLASS_ENUM (Region, RightOfSplit);
 	REGISTER_CLASS_ENUM (Region, Hidden);
-	REGISTER_CLASS_ENUM (Region, DoNotSaveState);
+	REGISTER_CLASS_ENUM (Region, DoNotSendPropertyChanges);
 	REGISTER_BITS (_Region_Flag);
 
 	REGISTER_CLASS_ENUM (Region, AudioTime);
diff --git a/libs/ardour/globals.cc b/libs/ardour/globals.cc
index a501e65931..0ce024c31e 100644
--- a/libs/ardour/globals.cc
+++ b/libs/ardour/globals.cc
@@ -430,6 +430,12 @@ ARDOUR::find_bindings_files (map<string,string>& files)
 	}
 }
 
+bool
+ARDOUR::no_auto_connect() 
+{
+	return getenv ("ARDOUR_NO_AUTOCONNECT") != 0;
+}
+
 ARDOUR::LocaleGuard::LocaleGuard (const char* str)
 {
 	old = strdup (setlocale (LC_NUMERIC, NULL));
diff --git a/libs/ardour/internal_return.cc b/libs/ardour/internal_return.cc
new file mode 100644
index 0000000000..409c87d93c
--- /dev/null
+++ b/libs/ardour/internal_return.cc
@@ -0,0 +1,136 @@
+/*
+    Copyright (C) 2009 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
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include <glibmm/thread.h>
+
+#include "pbd/failed_constructor.h"
+
+#include "ardour/internal_return.h"
+#include "ardour/mute_master.h"
+#include "ardour/session.h"
+
+using namespace std;
+using namespace ARDOUR;
+
+sigc::signal<void,nframes_t> InternalReturn::CycleStart;
+
+InternalReturn::InternalReturn (Session& s)
+	: Return (s, true)
+	, user_count (0)
+{
+	CycleStart.connect (mem_fun (*this, &InternalReturn::cycle_start));
+}
+
+InternalReturn::InternalReturn (Session& s, const XMLNode& node)
+	: Return (s, node, true)
+	, user_count (0)
+{
+	CycleStart.connect (mem_fun (*this, &InternalReturn::cycle_start));
+}
+
+void
+InternalReturn::run (BufferSet& bufs, sframes_t start_frame, sframes_t end_frame, nframes_t nframes)
+{
+	if (user_count == 0) {
+		/* nothing to do - nobody is feeding us anything */
+		return;
+	}
+
+	/* XXX this should be merge() */
+
+	bufs.merge_from (buffers, nframes);
+}
+
+bool
+InternalReturn::configure_io (ChanCount in, ChanCount out)
+{
+	IOProcessor::configure_io (in, out);
+	allocate_buffers (_session.get_block_size());
+	return true;
+}
+
+void 
+InternalReturn::set_block_size (nframes_t nframes)
+{
+	allocate_buffers (nframes);
+}
+
+void
+InternalReturn::allocate_buffers (nframes_t nframes)
+{
+	buffers.ensure_buffers (DataType::AUDIO, _configured_input.n_audio(), nframes);
+	buffers.ensure_buffers (DataType::MIDI, _configured_input.n_midi(), nframes);
+}
+
+BufferSet*
+InternalReturn::get_buffers ()
+{
+	Glib::Mutex::Lock lm (_session.engine().process_lock());
+	user_count++;
+	return &buffers;
+}
+
+void
+InternalReturn::release_buffers ()
+{
+	Glib::Mutex::Lock lm (_session.engine().process_lock());
+	if (user_count) {
+		user_count--;
+	}
+}
+
+void
+InternalReturn::cycle_start (nframes_t nframes)
+{
+	/* called from process cycle - no lock necessary */
+	if (user_count) {
+		/* don't bother with this if nobody is going to feed us anything */
+		buffers.silence (nframes, 0);
+	}
+}
+
+XMLNode&
+InternalReturn::state (bool full)
+{
+	XMLNode& node (Return::state (full));
+	/* override type */
+	node.add_property("type", "intreturn");
+	return node;
+}
+
+XMLNode&
+InternalReturn::get_state()
+{
+	return state (true);
+}
+
+int
+InternalReturn::set_state (const XMLNode& node)
+{
+	return Return::set_state (node);
+}
+
+bool 
+InternalReturn::can_support_io_configuration (const ChanCount& in, ChanCount& out) const
+{
+	out = in;
+	return true;
+}
+
+
+
diff --git a/libs/ardour/internal_send.cc b/libs/ardour/internal_send.cc
new file mode 100644
index 0000000000..398dbca08d
--- /dev/null
+++ b/libs/ardour/internal_send.cc
@@ -0,0 +1,192 @@
+/*
+    Copyright (C) 2009 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
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include <iostream>
+
+#include "pbd/error.h"
+#include "pbd/failed_constructor.h"
+
+#include "ardour/amp.h"
+#include "ardour/internal_send.h"
+#include "ardour/meter.h"
+#include "ardour/route.h"
+#include "ardour/session.h"
+
+#include "i18n.h"
+
+using namespace PBD;
+using namespace ARDOUR;
+
+InternalSend::InternalSend (Session& s, boost::shared_ptr<MuteMaster> mm, boost::shared_ptr<Route> sendto)
+	: Send (s, mm, true)
+	, _send_to (sendto)
+{
+	if ((target = _send_to->get_return_buffer ()) == 0) {
+		throw failed_constructor();
+	}
+
+	_send_to->GoingAway.connect (mem_fun (*this, &InternalSend::send_to_going_away));
+}
+
+InternalSend::InternalSend (Session& s, boost::shared_ptr<MuteMaster> mm, const XMLNode& node)
+	: Send (s, mm, node, true)
+{
+	set_state (node);
+}
+
+InternalSend::~InternalSend ()
+{
+	if (_send_to) {
+		_send_to->release_return_buffer ();
+	}
+
+	connect_c.disconnect ();
+}
+
+void
+InternalSend::send_to_going_away ()
+{
+	target = 0;
+	_send_to.reset ();
+	_send_to_id = "0";
+}
+
+void
+InternalSend::run (BufferSet& bufs, sframes_t start_frame, sframes_t end_frame, nframes_t nframes)
+{
+	if (!_active || !target || !_send_to) {
+		_meter->reset ();
+		return;
+	}
+
+	// we have to copy the input, because we may alter the buffers with the amp
+	// in-place, which a send must never do.
+	
+	BufferSet& sendbufs = _session.get_mix_buffers (bufs.count());
+	sendbufs.read_from (bufs, nframes);
+	assert(sendbufs.count() == bufs.count());
+
+	/* gain control */
+
+	// Can't automate gain for sends or returns yet because we need different buffers
+	// so that we don't overwrite the main automation data for the route amp
+	// _amp->setup_gain_automation (start_frame, end_frame, nframes);
+	_amp->run (sendbufs, start_frame, end_frame, nframes);
+
+	/* consider metering */
+	
+	if (_metering) {
+		if (_amp->gain_control()->get_value() == 0) {
+			_meter->reset();
+		} else {
+			_meter->run (sendbufs, start_frame, end_frame, nframes);
+		}
+	}
+
+	/* deliver to target */
+
+	target->merge_from (sendbufs, nframes);
+}
+
+bool
+InternalSend::feeds (boost::shared_ptr<Route> other) const
+{
+	return _send_to == other;
+}
+
+XMLNode&
+InternalSend::state (bool full)
+{
+	XMLNode& node (Send::state (full));
+
+	/* this replaces any existing property */
+
+	node.add_property ("type", "intsend");
+
+	if (_send_to) {
+		node.add_property ("target", _send_to->id().to_s());
+	}
+	
+	return node;
+}
+
+XMLNode&
+InternalSend::get_state()
+{
+	return state (true);
+}
+
+int
+InternalSend::set_state (const XMLNode& node)
+{
+	const XMLProperty* prop;
+
+	if ((prop = node.property ("target")) != 0) {
+
+		_send_to_id = prop->value();
+
+		/* if we're loading a session, the target route may not have been
+		   create yet. make sure we defer till we are sure that it should
+		   exist.
+		*/
+
+		if (!IO::connecting_legal) {
+			connect_c = IO::ConnectingLegal.connect (mem_fun (*this, &InternalSend::connect_when_legal));
+			std::cerr << "connect later!\n";
+		} else {
+			std::cerr << "connect NOW!\n";
+			connect_when_legal ();
+		}
+	}
+	
+	return 0;
+}
+
+int
+InternalSend::connect_when_legal ()
+{
+	std::cerr << "IOP/send connecting now that its legal\n";
+	
+	connect_c.disconnect ();
+
+	if (_send_to_id == "0") {
+		/* it vanished before we could connect */
+		return 0;
+	}
+
+	if ((_send_to = _session.route_by_id (_send_to_id)) == 0) {
+		error << X_("cannot find route to connect to") << endmsg;
+		std::cerr << "cannot find route with ID " << _send_to_id << std::endl;
+	} else {
+		std::cerr << "got target send as " << _send_to << std::endl;
+	}
+	
+	if ((target = _send_to->get_return_buffer ()) == 0) {
+		error << X_("target for internal send has no return buffer") << endmsg;
+	}
+
+	return 0;
+}
+
+bool 
+InternalSend::can_support_io_configuration (const ChanCount& in, ChanCount& out) const
+{
+	out = in;
+	return true;
+}
diff --git a/libs/ardour/io_processor.cc b/libs/ardour/io_processor.cc
index 7e0d4a771c..cfa2b4c689 100644
--- a/libs/ardour/io_processor.cc
+++ b/libs/ardour/io_processor.cc
@@ -64,6 +64,8 @@ IOProcessor::IOProcessor (Session& s, bool with_input, bool with_output,
 	if (with_output) {
 		_output.reset (new IO(s, io_name.empty() ? proc_name : io_name, IO::Output, dtype));
 	}
+
+	cerr << "fresh create IOP name = " << proc_name << " in = " << _input << " out = " << _output << endl;
 }
 
 /* create an IOProcessor that proxies to an existing IO object */
@@ -74,8 +76,18 @@ IOProcessor::IOProcessor (Session& s, boost::shared_ptr<IO> in, boost::shared_pt
 	, _input (in)
 	, _output (out)
 {
-	_own_input = false;
-	_own_output = false;
+	cerr << "XML create IOP name = " << proc_name << " in = " << in << " out = " << out << endl;
+	if (in) {
+		_own_input = false;
+	} else {
+		_own_input = true;
+	}
+
+	if (out) {
+		_own_output = false;
+	} else {
+		_own_output = true;
+	}
 }
 
 IOProcessor::~IOProcessor ()
@@ -107,10 +119,12 @@ IOProcessor::state (bool full_state)
 	XMLNode& node (Processor::state (full_state));
 	
 	if (_own_input) {
-		XMLNode& i (_input->state (full_state));
-		// i.name() = X_("output");
-		node.add_child_nocopy (i);
 		node.add_property ("own-input", "yes");
+		if (_input) {
+			XMLNode& i (_input->state (full_state));
+			// i.name() = X_("output");
+			node.add_child_nocopy (i);
+		}
 	} else {
 		node.add_property ("own-input", "no");
 		if (_input) {
@@ -119,10 +133,12 @@ IOProcessor::state (bool full_state)
 	}
 	
 	if (_own_output) {
-		XMLNode& o (_output->state (full_state));
-		// o.name() = X_("output");
-		node.add_child_nocopy (o);
 		node.add_property ("own-output", "yes");
+		if (_output) {
+			XMLNode& o (_output->state (full_state));
+			// o.name() = X_("output");
+			node.add_child_nocopy (o);
+		}
 	} else {
 		node.add_property ("own-output", "no");
 		if (_output) {
@@ -173,9 +189,9 @@ IOProcessor::set_state (const XMLNode& node)
 			}
 			
 		} else {
-			error << _("XML node describing an IOProcessor is missing an IO node") << endmsg;
-			return -1;
+			/* no input */
 		}
+
 	}
 	
 	if (_own_output) {
@@ -193,7 +209,9 @@ IOProcessor::set_state (const XMLNode& node)
 			if ((prop = node.property ("name")) == 0) {
 				set_name (_output->name());
 			}
-		} 
+		} else {
+			/* no output */
+		}
 	}
 
 	return 0;
@@ -246,3 +264,9 @@ IOProcessor::set_name (const std::string& name)
 
 	return ret;
 }
+
+bool
+IOProcessor::feeds (boost::shared_ptr<Route> other) const
+{
+	return _output && _output->connected_to (other->input());
+}
diff --git a/libs/ardour/meter.cc b/libs/ardour/meter.cc
index 0675e14cef..50bd290754 100644
--- a/libs/ardour/meter.cc
+++ b/libs/ardour/meter.cc
@@ -109,6 +109,11 @@ PeakMeter::run (BufferSet& bufs, sframes_t start_frame, sframes_t end_frame, nfr
 	}
 }
 
+PeakMeter::PeakMeter (Session& s, const XMLNode& node)
+	: Processor (s, node)
+{
+}
+
 void
 PeakMeter::reset ()
 {
diff --git a/libs/ardour/midi_buffer.cc b/libs/ardour/midi_buffer.cc
index bce47411cd..887545c662 100644
--- a/libs/ardour/midi_buffer.cc
+++ b/libs/ardour/midi_buffer.cc
@@ -99,6 +99,17 @@ MidiBuffer::read_from (const Buffer& src, nframes_t nframes, nframes_t dst_offse
 	_silent = src.silent();
 }
 
+void
+MidiBuffer::merge_from (const Buffer& src, nframes_t nframes, nframes_t dst_offset, nframes_t src_offset)
+{
+	const MidiBuffer* mbuf = dynamic_cast<const MidiBuffer*>(&src);
+	assert (mbuf);
+	assert (mbuf != this);
+
+	/* XXX use nframes, and possible offsets */
+	merge_in_place (*mbuf);
+}
+
 /** Push an event into the buffer.
  *
  * Note that the raw MIDI pointed to by ev will be COPIED and unmodified.
diff --git a/libs/ardour/panner.cc b/libs/ardour/panner.cc
index bd6d05a0b4..be72f65593 100644
--- a/libs/ardour/panner.cc
+++ b/libs/ardour/panner.cc
@@ -1379,7 +1379,7 @@ Panner::distribute_no_automation (BufferSet& inbufs, BufferSet& outbufs, nframes
 			if (inbufs.count().n_audio() > 0) {
 				BufferSet::audio_iterator i = inbufs.audio_begin();
 				for (++i; i != inbufs.audio_end(); ++i) {
-					dst.accumulate_from(*i, nframes);
+					dst.merge_from(*i, nframes);
 				}
 			}
 
@@ -1456,7 +1456,7 @@ Panner::run (BufferSet& inbufs, BufferSet& outbufs, sframes_t start_frame, sfram
 		// accumulate starting with the second
 		BufferSet::audio_iterator i = inbufs.audio_begin();
 		for (++i; i != inbufs.audio_end(); ++i) {
-			dst.accumulate_from(*i, nframes);
+			dst.merge_from(*i, nframes);
 		}
 
 		return;
diff --git a/libs/ardour/processor.cc b/libs/ardour/processor.cc
index 2e39c52d67..ab5902efa5 100644
--- a/libs/ardour/processor.cc
+++ b/libs/ardour/processor.cc
@@ -68,6 +68,17 @@ Processor::Processor(Session& session, const string& name)
 {
 }
 
+Processor::Processor (Session& session, const XMLNode& node)
+	: SessionObject(session, "renameMe")
+	, AutomatableControls(session)
+	, _active(false)
+	, _next_ab_is_active(false)
+	, _configured(false)
+	, _gui(0)
+{
+	set_state (node);
+}
+
 XMLNode&
 Processor::get_state (void)
 {
@@ -141,6 +152,9 @@ Processor::set_state (const XMLNode& node)
 	// may not exist for legacy 3.0 sessions
 	if ((prop = node.property ("id")) != 0) {
 		_id = prop->value();
+		cerr << "---------------- ID for processor " << name() << " = " << _id << endl;
+	} else {
+		cerr << "---------------- NO ID for processor " << name() << endl;
 	}
 
 	XMLNodeList nlist = node.children();
diff --git a/libs/ardour/region.cc b/libs/ardour/region.cc
index fb662beca3..1754e24b5e 100644
--- a/libs/ardour/region.cc
+++ b/libs/ardour/region.cc
@@ -61,7 +61,7 @@ sigc::signal<void,boost::shared_ptr<ARDOUR::Region> > Region::RegionPropertyChan
 Region::Region (Session& s, nframes_t start, nframes_t length, const string& name, DataType type, layer_t layer, Region::Flag flags)
 	: SessionObject(s, name)
 	, _type(type)
-	, _flags(flags)
+	, _flags(Flag (flags|DoNotSendPropertyChanges))
 	, _start(start) 
 	, _length(length) 
 	, _position(0) 
@@ -86,7 +86,7 @@ Region::Region (Session& s, nframes_t start, nframes_t length, const string& nam
 Region::Region (boost::shared_ptr<Source> src, nframes_t start, nframes_t length, const string& name, DataType type, layer_t layer, Region::Flag flags)
 	: SessionObject(src->session(), name)
 	, _type(type)
-	, _flags(flags)
+	, _flags(Flag (flags|DoNotSendPropertyChanges))
 	, _start(start) 
 	, _length(length) 
 	, _position(0) 
@@ -119,7 +119,7 @@ Region::Region (boost::shared_ptr<Source> src, nframes_t start, nframes_t length
 Region::Region (const SourceList& srcs, nframes_t start, nframes_t length, const string& name, DataType type, layer_t layer, Region::Flag flags)
 	: SessionObject(srcs.front()->session(), name)
 	, _type(type)
-	, _flags(flags)
+	, _flags(Flag (flags|DoNotSendPropertyChanges))
 	, _start(start) 
 	, _length(length) 
 	, _position(0) 
@@ -150,6 +150,8 @@ Region::Region (boost::shared_ptr<const Region> other, nframes_t offset, nframes
 	_start = other->_start + offset;
 	copy_stuff (other, offset, length, name, layer, flags);
 
+	_flags = Flag (_flags | DoNotSendPropertyChanges);
+
 	/* if the other region had a distinct sync point
 	   set, then continue to use it as best we can.
 	   otherwise, reset sync point back to start.
@@ -188,6 +190,8 @@ Region::Region (boost::shared_ptr<const Region> other, nframes_t length, const s
 	_start = 0;
 	copy_stuff (other, 0, length, name, layer, flags);
 
+	_flags = Flag (_flags | DoNotSendPropertyChanges);
+
 	/* sync pos is relative to start of file. our start-in-file is now zero,
 	   so set our sync position to whatever the the difference between
 	   _start and _sync_pos was in the other region. 
@@ -253,6 +257,8 @@ Region::Region (boost::shared_ptr<const Region> other)
 	, _pending_changed(Change(0))
 	, _last_layer_op(other->_last_layer_op)
 {
+	_flags = Flag (_flags | DoNotSendPropertyChanges);
+
 	other->_first_edit = EditChangesName;
 
 	if (other->_extra_xml) {
@@ -268,7 +274,7 @@ Region::Region (boost::shared_ptr<const Region> other)
 Region::Region (const SourceList& srcs, const XMLNode& node)
 	: SessionObject(srcs.front()->session(), X_("error: XML did not reset this"))
 	, _type(DataType::NIL) // to be loaded from XML
-	, _flags(Flag(0))
+	, _flags(DoNotSendPropertyChanges)
 	, _start(0) 
 	, _length(0) 
 	, _position(0) 
@@ -297,7 +303,7 @@ Region::Region (const SourceList& srcs, const XMLNode& node)
 Region::Region (boost::shared_ptr<Source> src, const XMLNode& node)
 	: SessionObject(src->session(), X_("error: XML did not reset this"))
 	, _type(DataType::NIL)
-	, _flags(Flag(0))
+	, _flags(DoNotSendPropertyChanges)
 	, _start(0) 
 	, _length(0) 
 	, _position(0) 
@@ -1400,7 +1406,7 @@ Region::send_change (Change what_changed)
 
 	StateChanged (what_changed);
 	
-	if (!(_flags & DoNotSaveState)) {
+	if (!(_flags & DoNotSendPropertyChanges)) {
 		
 		/* Try and send a shared_pointer unless this is part of the constructor.
 		   If so, do nothing.
diff --git a/libs/ardour/region_factory.cc b/libs/ardour/region_factory.cc
index a6bf4e0870..004321fa9e 100644
--- a/libs/ardour/region_factory.cc
+++ b/libs/ardour/region_factory.cc
@@ -47,6 +47,7 @@ RegionFactory::create (boost::shared_ptr<Region> region, nframes_t start,
 		AudioRegion* ar = new AudioRegion (other_a, start, length, name, layer, flags);
 		boost::shared_ptr<AudioRegion> arp (ar);
 		boost::shared_ptr<Region> ret (boost::static_pointer_cast<Region> (arp));
+		ret->unlock_property_changes ();
 		if (announce) {
 			CheckNewRegion (ret);
 		}
@@ -55,6 +56,7 @@ RegionFactory::create (boost::shared_ptr<Region> region, nframes_t start,
 		MidiRegion* ar = new MidiRegion (other_m, start, length, name, layer, flags);
 		boost::shared_ptr<MidiRegion> arp (ar);
 		boost::shared_ptr<Region> ret (boost::static_pointer_cast<Region> (arp));
+		ret->unlock_property_changes ();
 		if (announce) {
 			CheckNewRegion (ret);
 		}
@@ -75,10 +77,12 @@ RegionFactory::create (boost::shared_ptr<const Region> region)
 
 	if ((ar = boost::dynamic_pointer_cast<const AudioRegion>(region)) != 0) {
 		boost::shared_ptr<Region> ret (new AudioRegion (ar));
+		ret->unlock_property_changes ();
 		/* pure copy constructor - no CheckNewRegion emitted */
 		return ret;
 	} else if ((mr = boost::dynamic_pointer_cast<const MidiRegion>(region)) != 0) {
 		boost::shared_ptr<Region> ret (new MidiRegion (mr));
+		ret->unlock_property_changes ();
 		/* pure copy constructor - no CheckNewRegion emitted */
 		return ret;
 	} else {
@@ -112,6 +116,7 @@ RegionFactory::create (boost::shared_ptr<Region> region, const SourceList& srcs,
 		AudioRegion* ar = new AudioRegion (other, srcs, srcs.front()->length(srcs.front()->timeline_position()), name, layer, flags);
 		boost::shared_ptr<AudioRegion> arp (ar);
 		boost::shared_ptr<Region> ret (boost::static_pointer_cast<Region> (arp));
+		ret->unlock_property_changes ();
 		if (announce) {
 			CheckNewRegion (ret);
 		}
@@ -128,6 +133,7 @@ boost::shared_ptr<Region>
 RegionFactory::create (Session& session, XMLNode& node, bool yn)
 {
 	boost::shared_ptr<Region> r = session.XMLRegionFactory (node, yn);
+	r->unlock_property_changes ();
 
 	if (r) {
 		CheckNewRegion (r);
@@ -148,6 +154,7 @@ RegionFactory::create (const SourceList& srcs, nframes_t start, nframes_t length
 		AudioRegion* ar = new AudioRegion (srcs, start, length, name, layer, flags);
 		boost::shared_ptr<AudioRegion> arp (ar);
 		boost::shared_ptr<Region> ret (boost::static_pointer_cast<Region> (arp));
+		ret->unlock_property_changes ();
 		if (announce) {
 			CheckNewRegion (ret);
 		}
@@ -158,6 +165,7 @@ RegionFactory::create (const SourceList& srcs, nframes_t start, nframes_t length
 		MidiRegion* ar = new MidiRegion (srcs, start, length, name, layer, flags);
 		boost::shared_ptr<MidiRegion> mrp (ar);
 		boost::shared_ptr<Region> ret (boost::static_pointer_cast<Region> (mrp));
+		ret->unlock_property_changes ();
 		if (announce) {
 			CheckNewRegion (ret);
 		}
@@ -177,10 +185,12 @@ RegionFactory::create (SourceList& srcs, const XMLNode& node)
 
 	if (srcs[0]->type() == DataType::AUDIO) {
 		boost::shared_ptr<Region> ret (new AudioRegion (srcs, node));
+		ret->unlock_property_changes ();
 		CheckNewRegion (ret);
 		return ret;
 	} else if (srcs[0]->type() == DataType::MIDI) {
 		boost::shared_ptr<Region> ret (new MidiRegion (srcs, node));
+		ret->unlock_property_changes ();
 		CheckNewRegion (ret);
 		return ret;
 	}
@@ -196,12 +206,14 @@ RegionFactory::create (boost::shared_ptr<Source> src, nframes_t start, nframes_t
 
 	if ((as = boost::dynamic_pointer_cast<AudioSource>(src)) != 0) {
 		boost::shared_ptr<Region> ret (new AudioRegion (as, start, length, name, layer, flags));
+		ret->unlock_property_changes ();
 		if (announce) {
 			CheckNewRegion (ret);
 		}
 		return ret;
 	} else if ((ms = boost::dynamic_pointer_cast<MidiSource>(src)) != 0) {
 		boost::shared_ptr<Region> ret (new MidiRegion (ms, start, length, name, layer, flags));
+		ret->unlock_property_changes ();
 		if (announce) {
 			CheckNewRegion (ret);
 		}
diff --git a/libs/ardour/return.cc b/libs/ardour/return.cc
index 574b6736a0..5a44d3f6e6 100644
--- a/libs/ardour/return.cc
+++ b/libs/ardour/return.cc
@@ -36,8 +36,9 @@
 using namespace ARDOUR;
 using namespace PBD;
 
-Return::Return (Session& s)
-	: IOProcessor (s, true, false, string_compose (_("return %1"), (_bitslot = s.next_return_id()) + 1))
+Return::Return (Session& s, bool internal)
+	: IOProcessor (s, (internal ? false : true), false, 
+		       string_compose (_("return %1"), (_bitslot = s.next_return_id()) + 1))
 	, _metering (false)
 {
 	/* never muted */
@@ -48,8 +49,8 @@ Return::Return (Session& s)
 	ProcessorCreated (this); /* EMIT SIGNAL */
 }
 
-Return::Return (Session& s, const XMLNode& node)
-	: IOProcessor (s, true, false, "return")
+Return::Return (Session& s, const XMLNode& node, bool internal)
+	: IOProcessor (s, (internal ? false : true), false, "return")
 	, _metering (false)
 {
 	/* never muted */
diff --git a/libs/ardour/route.cc b/libs/ardour/route.cc
index 36b0a6bf68..0b6c3c48ca 100644
--- a/libs/ardour/route.cc
+++ b/libs/ardour/route.cc
@@ -38,6 +38,8 @@
 #include "ardour/configuration.h"
 #include "ardour/cycle_timer.h"
 #include "ardour/dB.h"
+#include "ardour/internal_send.h"
+#include "ardour/internal_return.h"
 #include "ardour/ladspa_plugin.h"
 #include "ardour/meter.h"
 #include "ardour/mix.h"
@@ -73,6 +75,24 @@ Route::Route (Session& sess, string name, Flag flg, DataType default_type)
 	  
 {
 	init ();
+	
+	/* add standard processors other than amp (added by ::init()) */
+	
+	_meter.reset (new PeakMeter (_session));
+	add_processor (_meter, PreFader);
+
+	if (_flags & ControlOut) {
+		/* where we listen to tracks */
+		_intreturn.reset (new InternalReturn (_session));
+		add_processor (_intreturn, PreFader);
+	}
+	
+	_main_outs.reset (new Delivery (_session, _output, _mute_master, _name, Delivery::Main));
+	add_processor (_main_outs, PostFader);
+
+	/* now that we have _meter, its safe to connect to this */
+
+	_meter_connection = Metering::connect (mem_fun (*this, &Route::meter));
 }
 
 Route::Route (Session& sess, const XMLNode& node, DataType default_type)
@@ -83,7 +103,12 @@ Route::Route (Session& sess, const XMLNode& node, DataType default_type)
 	, _default_type (default_type)
 {
 	init ();
+
 	_set_state (node, false);
+
+	/* now that we have _meter, its safe to connect to this */
+	
+	_meter_connection = Metering::connect (mem_fun (*this, &Route::meter));
 }
 
 void
@@ -123,20 +148,10 @@ Route::init ()
 	_input->changed.connect (mem_fun (this, &Route::input_change_handler));
 	_output->changed.connect (mem_fun (this, &Route::output_change_handler));
 
-	/* add standard processors */
+	/* add amp processor  */
 
 	_amp.reset (new Amp (_session, _mute_master));
 	add_processor (_amp, PostFader);
-
-	_meter.reset (new PeakMeter (_session));
-	add_processor (_meter, PreFader);
-	
-	_main_outs.reset (new Delivery (_session, _output, _mute_master, _name, Delivery::Main));
-	add_processor (_main_outs, PostFader);
-
-	/* now we can meter */
-	
-	_meter_connection = Metering::connect (mem_fun (*this, &Route::meter));
 }
 
 Route::~Route ()
@@ -316,7 +331,7 @@ Route::process_output_buffers (BufferSet& bufs,
 	switch (Config->get_monitoring_model()) {
 	case HardwareMonitoring:
 	case ExternalMonitoring:
-		monitor = record_enabled() && (_session.config.get_auto_input() || _session.actively_recording());
+		monitor = !record_enabled() || (_session.config.get_auto_input() && !_session.actively_recording());
 		break;
 	default:
 		monitor = true;
@@ -327,13 +342,13 @@ Route::process_output_buffers (BufferSet& bufs,
 	}
 
 	/* figure out if we're going to use gain automation */
-
 	_amp->setup_gain_automation (start_frame, end_frame, nframes);
 	
-	/* tell main outs what to do about monitoring */
 
+	/* tell main outs what to do about monitoring */
 	_main_outs->no_outs_cuz_we_no_monitor (!monitor);
 
+
 	/* -------------------------------------------------------------------------------------------
 	   GLOBAL DECLICK (for transport changes etc.)
 	   ----------------------------------------------------------------------------------------- */
@@ -520,25 +535,16 @@ Route::muted() const
 	return _mute_master->muted ();
 }
 
-#if DEFINE_IF_YOU_NEED_THIS
 static void
 dump_processors(const string& name, const list<boost::shared_ptr<Processor> >& procs)
 {
 	cerr << name << " {" << endl;
 	for (list<boost::shared_ptr<Processor> >::const_iterator p = procs.begin();
 			p != procs.end(); ++p) {
-		cerr << "\t" << (*p)->name() << endl;
+		cerr << "\t" << (*p)->name() << " ID = " << (*p)->id() << endl;
 	}
 	cerr << "}" << endl;
 }
-#endif
-
-Route::ProcessorList::iterator
-Route::prefader_iterator() 
-{
-	Glib::RWLock::ReaderLock lm (_processor_lock);
-	return find (_processors.begin(), _processors.end(), _amp);
-}
 
 int
 Route::add_processor (boost::shared_ptr<Processor> processor, Placement placement, ProcessorStreams* err)
@@ -615,6 +621,8 @@ Route::add_processor (boost::shared_ptr<Processor> processor, ProcessorList::ite
 			loc = iter;
 		}
 
+		cerr << "Adding " << processor->name() << " @ " << processor << endl;
+
 		_processors.insert (loc, processor);
 
 		// Set up processor list channels.  This will set processor->[input|output]_streams(),
@@ -626,6 +634,7 @@ Route::add_processor (boost::shared_ptr<Processor> processor, ProcessorList::ite
 			--ploc;
 			_processors.erase(ploc);
 			configure_processors_unlocked (0); // it worked before we tried to add it ...
+			cerr << "configure failed\n";
 			return -1;
 		}
 	
@@ -660,6 +669,7 @@ bool
 Route::add_processor_from_xml (const XMLNode& node, Placement placement)
 {
 	ProcessorList::iterator loc;
+
 	if (placement == PreFader) {
 		/* generic pre-fader: insert immediately before the amp */
 		loc = find(_processors.begin(), _processors.end(), _amp);
@@ -699,7 +709,6 @@ Route::add_processor_from_xml (const XMLNode& node, ProcessorList::iterator iter
 				cerr << _name << " : got processor type " << prop->value() << endl;
 
 				boost::shared_ptr<Processor> processor;
-				bool have_insert = false;
 
 				if (prop->value() == "ladspa" || prop->value() == "Ladspa" || 
 				    prop->value() == "lv2" ||
@@ -707,7 +716,6 @@ Route::add_processor_from_xml (const XMLNode& node, ProcessorList::iterator iter
 				    prop->value() == "audiounit") {
 					
 					processor.reset (new PluginInsert(_session, node));
-					have_insert = true;
 					
 				} else if (prop->value() == "port") {
 
@@ -716,32 +724,66 @@ Route::add_processor_from_xml (const XMLNode& node, ProcessorList::iterator iter
 				} else if (prop->value() == "send") {
 
 					processor.reset (new Send (_session, _mute_master, node));
-					have_insert = true;
-				
+
 				} else if (prop->value() == "meter") {
 
+					if (_meter) {
+						if (_meter->set_state (node)) {
+							return false;
+						} else {
+							return true;
+						}
+					}
+
+					_meter.reset (new PeakMeter (_session, node));						
 					processor = _meter;
-					processor->set_state (node);
 				
 				} else if (prop->value() == "amp") {
+
+					/* amp always exists */
 					
 					processor = _amp;
-					processor->set_state (node);
+					if (processor->set_state (node)) {
+						return false;
+					} else {
+						/* never any reason to add it */
+						return true;
+					}
 					
 				} else if (prop->value() == "listen" || prop->value() == "deliver") {
 
 					/* XXX need to generalize */
 
-					processor = _control_outs;
-					processor->set_state (node);
+				} else if (prop->value() == "intsend") {
+
+					processor.reset (new InternalSend (_session, _mute_master, node));
+				
+				} else if (prop->value() == "intreturn") {
 					
+					if (_intreturn) {
+						if (_intreturn->set_state (node)) {
+							return false;
+						} else {
+							return true;
+						}
+					}
+					_intreturn.reset (new InternalReturn (_session, node));
+					processor = _intreturn;
+
 				} else if (prop->value() == "main-outs") {
 					
+					if (_main_outs) {
+						if (_main_outs->set_state (node)) {
+							return false;
+						} else {
+							return true;
+						}
+					}
+
+					_main_outs.reset (new Delivery (_session, _output, _mute_master, node));
 					processor = _main_outs;
-					processor->set_state (node);
 
 				} else {
-
 					error << string_compose(_("unknown Processor type \"%1\"; ignored"), prop->value()) << endmsg;
 				}
 				
@@ -997,31 +1039,6 @@ Route::ab_plugins (bool forward)
 }
 	
 	
-/* Figure out the streams that will feed into PreFader */
-ChanCount
-Route::pre_fader_streams() const
-{
-	boost::shared_ptr<Processor> processor;
-
-	/* Find the last pre-fader redirect that isn't a send; sends don't affect the number
-	 * of streams. */
-	for (ProcessorList::const_iterator i = _processors.begin(); i != _processors.end(); ++i) {
-		if ((*i) == _amp) {
-			break;
-		}
-		if (boost::dynamic_pointer_cast<Send> (*i) == 0) {
-			processor = *i;
-		}
-	}
-	
-	if (processor) {
-		return processor->output_streams();
-	} else {
-		return _input->n_ports ();
-	}
-}
-
-
 /** Remove processors with a given placement.
  * @param p Placement of processors to remove.
  */
@@ -1195,7 +1212,11 @@ Route::configure_processors_unlocked (ProcessorStreams* err)
 	ChanCount out;
 	list< pair<ChanCount,ChanCount> > configuration;
 	uint32_t index = 0;
+	
+	cerr << "Processor check with " << _processors.size() << endl;
+
 	for (ProcessorList::iterator p = _processors.begin(); p != _processors.end(); ++p, ++index) {
+		cerr << "Checking out " << (*p)->name() << " type = " << endl;
 		if ((*p)->can_support_io_configuration(in, out)) {
 			configuration.push_back(make_pair(in, out));
 			in = out;
@@ -1488,6 +1509,34 @@ Route::_set_state (const XMLNode& node, bool call_base)
 	} else {
 		_flags = Flag (0);
 	}
+
+	/* add all processors (except amp, which is always present) */
+
+	nlist = node.children();
+	XMLNode processor_state (X_("processor_state"));
+
+	for (niter = nlist.begin(); niter != nlist.end(); ++niter){
+		
+		child = *niter;
+
+		if (child->name() == IO::state_node_name) {
+			if ((prop = child->property (X_("direction"))) == 0) {
+				continue;
+			}
+			
+			if (prop->value() == "Input") {
+				_input->set_state (*child);
+			} else if (prop->value() == "Output") {
+				_output->set_state (*child);
+			}
+		}
+			
+		if (child->name() == X_("Processor")) {
+			processor_state.add_child_copy (*child);
+		}
+	}
+
+	set_processor_state (processor_state);
 	
 	if ((prop = node.property (X_("phase-invert"))) != 0) {
 		set_phase_invert (prop->value()=="yes"?true:false);
@@ -1555,32 +1604,6 @@ Route::_set_state (const XMLNode& node, bool call_base)
 		}
 	}
 
-	nlist = node.children();
-	XMLNode processor_state (X_("processor_state"));
-
-	for (niter = nlist.begin(); niter != nlist.end(); ++niter){
-		
-		child = *niter;
-
-		if (child->name() == IO::state_node_name) {
-			if ((prop = child->property (X_("direction"))) == 0) {
-				continue;
-			}
-			
-			if (prop->value() == "Input") {
-				_input->set_state (*child);
-			} else if (prop->value() == "Output") {
-				_output->set_state (*child);
-			}
-		}
-			
-		if (child->name() == X_("Processor")) {
-			processor_state.add_child_copy (*child);
-		}
-	}
-
-	set_processor_state (processor_state);
-	
 	for (niter = nlist.begin(); niter != nlist.end(); ++niter){
 		child = *niter;
 
@@ -1642,21 +1665,30 @@ Route::set_processor_state (const XMLNode& node)
 {
 	const XMLNodeList &nlist = node.children();
 	XMLNodeConstIterator niter;
-	bool has_meter_processor = false; // legacy sessions don't
 	ProcessorList::iterator i, o;
 
-	cerr << _name << " _set_processor_states\n";
+	dump_processors ("set processor states", _processors);
 
 	// Iterate through existing processors, remove those which are not in the state list
+
 	for (i = _processors.begin(); i != _processors.end(); ) {
+
+		/* leave amp alone, always */
+
+		if ((*i) == _amp) {
+			++i;
+			continue;
+		}
+
 		ProcessorList::iterator tmp = i;
 		++tmp;
 
 		bool processorInStateList = false;
-	
+
 		for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
 
 			XMLProperty* id_prop = (*niter)->property(X_("id"));
+			cerr << "\tchecking " << id_prop->value() << endl;
 			if (id_prop && (*i)->id() == id_prop->value()) {
 				processorInStateList = true;
 				break;
@@ -1672,26 +1704,24 @@ Route::set_processor_state (const XMLNode& node)
 
 	// Iterate through state list and make sure all processors are on the track and in the correct order,
 	// set the state of existing processors according to the new state on the same go
+
 	i = _processors.begin();
 
 	for (niter = nlist.begin(); niter != nlist.end(); ++niter, ++i) {
 		
 		XMLProperty* prop = (*niter)->property ("type");
 
-		if (prop && prop->value() == "meter")  {
-			has_meter_processor = true;
-		}
-
 		o = i;
 
-		if (prop->value() != "meter" && prop->value() != "amp" && prop->value() != "main-outs") {
-
-			// Check whether the next processor in the list 
-			
+		// Check whether the next processor in the list is the right one,
+		// except for "amp" which is always there and may not have the
+		// old ID since it is always created anew in every Route
+		
+		if (prop->value() != "amp") {
 			while (o != _processors.end()) {
 				XMLProperty* id_prop = (*niter)->property(X_("id"));
 				if (id_prop && (*o)->id() == id_prop->value()) {
-					break;
+				break;
 				}
 				
 				++o;
@@ -1700,6 +1730,7 @@ Route::set_processor_state (const XMLNode& node)
 
 		// If the processor (*niter) is not on the route,
 		// create it and move it to the correct location
+
 		if (o == _processors.end()) {
 
 			if (add_processor_from_xml (**niter, i)) {
@@ -1708,10 +1739,11 @@ Route::set_processor_state (const XMLNode& node)
 				cerr << "Error restoring route: unable to restore processor" << endl;
 			}
 
-		// Otherwise, the processor already exists; just
-		// ensure it is at the location provided in the XML state
 		} else {
 
+			// Otherwise, the processor already exists; just
+			// ensure it is at the location provided in the XML state
+
 			if (i != o) {
 				boost::shared_ptr<Processor> tmp = (*o);
 				_processors.erase (o); // remove the old copy
@@ -1719,6 +1751,8 @@ Route::set_processor_state (const XMLNode& node)
 				--i; // move iterator to the correct processor
 			}
 
+			// and make it (just) so
+
 			(*i)->set_state (**niter);
 		}
 	}
@@ -1727,10 +1761,6 @@ Route::set_processor_state (const XMLNode& node)
 	   the XML state represents a working signal route.
 	*/
 
-	if (!has_meter_processor) {
-		set_meter_point (_meter_point, NULL);
-	}
-
 	processors_changed ();
 }
 
@@ -1772,33 +1802,38 @@ Route::silence (nframes_t nframes)
 	}
 }	
 
-boost::shared_ptr<Delivery>
-Route::add_listener (boost::shared_ptr<IO> io, const string& listen_name)
+BufferSet*
+Route::get_return_buffer () const
 {
- 	string name = _name;
-	name += '[';
- 	name += listen_name;
-	name += ']';
- 	
-	boost::shared_ptr<Delivery> listener (new Delivery (_session, _mute_master, name, Delivery::Listen)); 
-
-	/* As an IO, our control outs need as many IO outputs as we have outputs
-	 *   (we track the changes in ::output_change_handler()).
-	 * As a processor, the listener is an identity processor
-	 *   (i.e. it does not modify its input buffers whatsoever)
-	 */
-
-	if (listener->output()->ensure_io (n_outputs(), true, this)) {
-		return boost::shared_ptr<Delivery>();
+	Glib::RWLock::ReaderLock rm (_processor_lock);
+	
+	for (ProcessorList::const_iterator x = _processors.begin(); x != _processors.end(); ++x) {
+		boost::shared_ptr<InternalReturn> d = boost::dynamic_pointer_cast<InternalReturn>(*x);
+		
+		if (d) {
+			return d->get_buffers ();
+		}
 	}
 	
-	add_processor (listener, PostFader);
+	return 0;
+}
 
-	return listener;
+void
+Route::release_return_buffer () const
+{
+	Glib::RWLock::ReaderLock rm (_processor_lock);
+	
+	for (ProcessorList::const_iterator x = _processors.begin(); x != _processors.end(); ++x) {
+		boost::shared_ptr<InternalReturn> d = boost::dynamic_pointer_cast<InternalReturn>(*x);
+		
+		if (d) {
+			return d->release_buffers ();
+		}
+	}
 }
 
 int
-Route::listen_via (boost::shared_ptr<IO> io, const string& listen_name)
+Route::listen_via (boost::shared_ptr<Route> route, const string& listen_name)
 {
 	vector<string> ports;
 	vector<string>::const_iterator i;
@@ -1807,71 +1842,58 @@ Route::listen_via (boost::shared_ptr<IO> io, const string& listen_name)
 		Glib::RWLock::ReaderLock rm (_processor_lock);
 		
 		for (ProcessorList::const_iterator x = _processors.begin(); x != _processors.end(); ++x) {
-			boost::shared_ptr<const Delivery> d = boost::dynamic_pointer_cast<const Delivery>(*x);
+			boost::shared_ptr<const InternalSend> d = boost::dynamic_pointer_cast<const InternalSend>(*x);
 
-			if (d && d->output() == io) {
+			if (d && d->target_route() == route) {
 				/* already listening via the specified IO: do nothing */
 				return 0;
 			}
 		}
 	}
-
-	uint32_t ni = io->n_ports().n_total();
-
-	for (uint32_t n = 0; n < ni; ++n) {
-		ports.push_back (io->nth (n)->name());
-	}
-
- 	if (ports.empty()) {
- 		return 0;
- 	}
 	
-	boost::shared_ptr<Delivery> listen_point = add_listener (io, listen_name);
-	
-	/* XXX hack for now .... until we can generalize listen points */
+	boost::shared_ptr<InternalSend> listener;
 
-	_control_outs = listen_point;
+	try {
+		listener.reset (new InternalSend (_session, _mute_master, route));
 
-	/* now connect to the named ports */
-	
-	ni = listen_point->output()->n_ports().n_total();
-	size_t psize = ports.size();
+	} catch (failed_constructor& err) {
 
-	for (size_t n = 0; n < ni; ++n) {
-		if (listen_point->output()->connect (listen_point->output()->nth (n), ports[n % psize], this)) {
-			error << string_compose (_("could not connect %1 to %2"),
-						 listen_point->output()->nth (n)->name(), ports[n % psize]) << endmsg;
-			return -1;
-		}
+		return -1;
 	}
 
+	add_processor (listener, PreFader);
 	
  	return 0;
 }	
 
 void
-Route::drop_listen (boost::shared_ptr<IO> io)
+Route::drop_listen (boost::shared_ptr<Route> route)
 {
 	ProcessorStreams err;
 	ProcessorList::iterator tmp;
 
-	Glib::RWLock::ReaderLock rm (_processor_lock);
+	Glib::RWLock::ReaderLock rl(_processor_lock);
+	rl.acquire ();
 	
+  again:
 	for (ProcessorList::iterator x = _processors.begin(); x != _processors.end(); ) {
 		
-		tmp = x;
-		++tmp;
-		
-		boost::shared_ptr<Delivery> d = boost::dynamic_pointer_cast<Delivery>(*x);
+		boost::shared_ptr<InternalSend> d = boost::dynamic_pointer_cast<InternalSend>(*x);
 		
-		if (d && d->output() == io) {
-			/* already listening via the specified IO: do nothing */
+		if (d && d->target_route() == route) {
+			rl.release ();
 			remove_processor (*x, &err);
-			
+			rl.acquire ();
+
+                        /* list could have been demolished while we dropped the lock
+			   so start over.
+			*/
+
+			goto again; 
 		} 
-		
-		x = tmp;
 	}
+
+	rl.release ();
 }
 
 void
@@ -1939,25 +1961,30 @@ Route::set_comment (string cmt, void *src)
 }
 
 bool
-Route::feeds (boost::shared_ptr<IO> other)
+Route::feeds (boost::shared_ptr<Route> other)
 {
-	if (_output->connected_to (other)) {
+	// cerr << _name << endl;
+
+	if (_output->connected_to (other->input())) {
+		// cerr << "\tdirect FEEDS " << other->name() << endl;
 		return true;
 	}
 
-	/* check IOProcessors which may also interconnect Routes */
-
 	for (ProcessorList::iterator r = _processors.begin(); r != _processors.end(); r++) {
-
+		
 		boost::shared_ptr<IOProcessor> iop;
 		
 		if ((iop = boost::dynamic_pointer_cast<IOProcessor>(*r)) != 0) {
-			if (iop->output() && iop->output()->connected_to (other)) {
+			if (iop->feeds (other)) {
+				// cerr << "\tIOP " << iop->name() << " feeds " << other->name() << endl;
 				return true;
+			} else {
+				// cerr << "\tIOP " << iop->name() << " does NOT feeds " << other->name() << endl;
 			}
 		}
 	}
 
+	// cerr << "\tdoes NOT FEED " << other->name() << endl;
 	return false;
 }
 
@@ -2418,15 +2445,15 @@ Route::set_name (const string& str)
 }
 
 boost::shared_ptr<Send>
-Route::send_for (boost::shared_ptr<const IO> target) const
+Route::internal_send_for (boost::shared_ptr<const Route> target) const
 {
 	Glib::RWLock::ReaderLock lm (_processor_lock);
 
 	for (ProcessorList::const_iterator i = _processors.begin(); i != _processors.end(); ++i) {
-		boost::shared_ptr<Send> send;
+		boost::shared_ptr<InternalSend> send;
 		
-		if ((send = boost::dynamic_pointer_cast<Send>(*i)) != 0) {
-			if (send->output()->connected_to (target)) {
+		if ((send = boost::dynamic_pointer_cast<InternalSend>(*i)) != 0) {
+			if (send->target_route() == target) {
 				return send;
 			}
 		}
diff --git a/libs/ardour/send.cc b/libs/ardour/send.cc
index ad66f73796..71685e1b88 100644
--- a/libs/ardour/send.cc
+++ b/libs/ardour/send.cc
@@ -36,8 +36,9 @@
 using namespace ARDOUR;
 using namespace PBD;
 
-Send::Send (Session& s, boost::shared_ptr<MuteMaster> mm)
-	: Delivery (s, mm, string_compose (_("send %1"), (_bitslot = s.next_send_id()) + 1), Delivery::Send)
+Send::Send (Session& s, boost::shared_ptr<MuteMaster> mm, bool internal)
+	: Delivery (s, mm, string_compose (_("send %1"), (_bitslot = s.next_send_id()) + 1), 
+		    (internal ? Delivery::Listen : Delivery::Send))
 	, _metering (false)
 {
 	_amp.reset (new Amp (_session, _mute_master));
@@ -46,8 +47,8 @@ Send::Send (Session& s, boost::shared_ptr<MuteMaster> mm)
 	ProcessorCreated (this); /* EMIT SIGNAL */
 }
 
-Send::Send (Session& s, boost::shared_ptr<MuteMaster> mm, const XMLNode& node)
-	: Delivery (s, mm, "send", Delivery::Send)
+Send::Send (Session& s, boost::shared_ptr<MuteMaster> mm, const XMLNode& node, bool internal)
+        : Delivery (s, mm, "send", (internal ? Delivery::Listen : Delivery::Send))
 	, _metering (false)
 {
 	_amp.reset (new Amp (_session, _mute_master));
@@ -113,6 +114,7 @@ Send::state(bool full)
 {
 	XMLNode& node = IOProcessor::state(full);
 	char buf[32];
+
 	node.add_property ("type", "send");
 	snprintf (buf, sizeof (buf), "%" PRIu32, _bitslot);
 	node.add_property ("bitslot", buf);
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 394193e8b2..db30fea021 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -294,6 +294,11 @@ Session::Session (AudioEngine &eng,
 
 	}
 
+	if (no_auto_connect()) {
+		input_ac = AutoConnectOption (0);
+		output_ac = AutoConnectOption (0);
+	}
+
 	Config->set_input_auto_connect (input_ac);
 	Config->set_output_auto_connect (output_ac);
 
@@ -607,6 +612,8 @@ Session::when_engine_running ()
 	   it doesn't really scale that well to higher channel counts 
 	*/
 
+	/* mono output bundles */
+
 	for (uint32_t np = 0; np < n_physical_outputs; ++np) {
 		char buf[32];
 		snprintf (buf, sizeof (buf), _("out %" PRIu32), np+1);
@@ -618,6 +625,8 @@ Session::when_engine_running ()
  		add_bundle (c);
 	}
 
+	/* stereo output bundles */
+
 	for (uint32_t np = 0; np < n_physical_outputs; np += 2) {
 		if (np + 1 < n_physical_outputs) {
 			char buf[32];
@@ -632,6 +641,8 @@ Session::when_engine_running ()
 		}
 	}
 
+	/* mono input bundles */
+
 	for (uint32_t np = 0; np < n_physical_inputs; ++np) {
 		char buf[32];
 		snprintf (buf, sizeof (buf), _("in %" PRIu32), np+1);
@@ -643,6 +654,8 @@ Session::when_engine_running ()
  		add_bundle (c);
 	}
 
+	/* stereo input bundles */
+
 	for (uint32_t np = 0; np < n_physical_inputs; np += 2) {
 		if (np + 1 < n_physical_inputs) {
 			char buf[32];
@@ -658,16 +671,15 @@ Session::when_engine_running ()
 		}
 	}
 
-	/* create master/control ports */
-	
-	if (_master_out) {
+	if (Config->get_auto_connect_standard_busses() && !no_auto_connect()) {
 
-		/* if requested auto-connect the outputs to the first N physical ports.
-		*/
+		if (_master_out) {
+			
+			/* if requested auto-connect the outputs to the first N physical ports.
+			 */
 
-		if (Config->get_auto_connect_master()) {
 			uint32_t limit = _master_out->n_outputs().n_total();
-
+			
 			for (uint32_t n = 0; n < limit; ++n) {
 				Port* p = _master_out->output()->nth (n);
 				string connect_to = _engine.get_nth_physical_output (DataType (p->type()), n);
@@ -681,40 +693,31 @@ Session::when_engine_running ()
 				}
 			}
 		}
-	}
-
-	BootMessage (_("Setup signal flow and plugins"));
 
-	hookup_io ();
+		if (_control_out) {
 
-	/* catch up on send+insert cnts */
-
-	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;
-
-		if (sscanf ((*i)->name().c_str(), "%*s %u", &id) == 1) {
-			if (id > insert_cnt) {
-				insert_cnt = id;
+			uint32_t limit = _control_out->n_outputs().n_total();
+			
+			for (uint32_t n = 0; n < limit; ++n) {
+				Port* p = _control_out->output()->nth (n);
+				string connect_to = _engine.get_nth_physical_output (DataType (p->type()), n);
+				
+				if (!connect_to.empty()) {
+					if (_control_out->output()->connect (p, connect_to, this)) {
+						error << string_compose (_("cannot connect control output %1 to %2"), n, connect_to) 
+						      << endmsg;
+						break;
+					}
+				}
 			}
 		}
 	}
 
-	send_cnt = 0;
-
-	for (list<Send*>::iterator i = _sends.begin(); i != _sends.end(); ++i) {
-		uint32_t id;
+	BootMessage (_("Setup signal flow and plugins"));
 
-		if (sscanf ((*i)->name().c_str(), "%*s %u", &id) == 1) {
-			if (id > send_cnt) {
-				send_cnt = id;
-			}
-		}
-	}
+	hookup_io ();
 
+	/* catch up on send+insert cnts */
 
 	_state_of_the_state = StateOfTheState (_state_of_the_state & ~(CannotSave|Dirty));
 
@@ -751,24 +754,6 @@ Session::hookup_io ()
 		}
 	}
 
-	/* Connect track to listen/solo etc. busses XXX generalize this beyond control_out */
-
-	if (_control_out) {
-
-		// _control_out->ensure_io (_control_out->input_minimum(), _control_out->output_minimum(), false, this);
-
-		boost::shared_ptr<RouteList> r = routes.reader ();
-		
-		for (RouteList::iterator x = r->begin(); x != r->end(); ++x) {
-
-			boost::shared_ptr<Track> t = boost::dynamic_pointer_cast<Track> (*x);
-
-			if (t) {
-				t->listen_via (_control_out->input(), X_("listen"));
-			}
-		}
-	}
-
 	/* load bundles, which we may have postponed earlier on */
 	if (_bundle_xml_node) {
 		load_bundles (*_bundle_xml_node);
@@ -783,6 +768,22 @@ Session::hookup_io ()
 
 	Delivery::reset_panners ();
 
+	/* Connect tracks to listen/solo etc. busses XXX generalize this beyond control_out */
+
+	if (_control_out) {
+
+		boost::shared_ptr<RouteList> r = routes.reader ();
+		
+		for (RouteList::iterator x = r->begin(); x != r->end(); ++x) {
+
+			boost::shared_ptr<Track> t = boost::dynamic_pointer_cast<Track> (*x);
+
+			if (t) {
+				t->listen_via (_control_out, X_("listen"));
+			}
+		}
+	}
+
 	/* Anyone who cares about input state, wake up and do something */
 
 	IOConnectionsComplete (); /* EMIT SIGNAL */
@@ -1455,7 +1456,7 @@ Session::resort_routes_using (shared_ptr<RouteList> r)
 				continue;
 			}
 
-			if ((*j)->feeds ((*i)->input())) {
+			if ((*j)->feeds (*i)) {
 				(*i)->fed_by.insert (*j);
 			}
 		}
@@ -2064,7 +2065,10 @@ 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());
-		resort_routes_using (r);
+
+		if (!_control_out && IO::connecting_legal) {
+			resort_routes_using (r);
+		}
 	}
 
 	for (RouteList::iterator x = new_routes.begin(); x != new_routes.end(); ++x) {
@@ -2088,8 +2092,10 @@ Session::add_routes (RouteList& new_routes, bool save)
 	if (_control_out && IO::connecting_legal) {
 
 		for (RouteList::iterator x = new_routes.begin(); x != new_routes.end(); ++x) {
-			(*x)->listen_via (_control_out->input(), "control");
+			(*x)->listen_via (_control_out, "control");
 		}
+
+		resort_routes ();
 	}
 
 	set_dirty();
@@ -2145,13 +2151,14 @@ Session::remove_route (shared_ptr<Route> route)
 		}
 
 		if (route == _control_out) {
+
 			/* cancel control outs for all routes */
 
 			for (RouteList::iterator r = rs->begin(); r != rs->end(); ++r) {
-				(*r)->drop_listen (_control_out->input());
+				(*r)->drop_listen (_control_out);
 			}
 
-			_control_out = shared_ptr<Route> ();
+			_control_out.reset ();
 		}
 
 		update_route_solo_state ();
@@ -2238,7 +2245,7 @@ Session::route_solo_changed (void* src, boost::weak_ptr<Route> wpr)
 	solo_update_disabled = true;
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 
-		if ((*i)->feeds (route->input())) {
+		if ((*i)->feeds (route)) {
 			/* do it */
 			
 			(*i)->main_outs()->mod_solo_level (delta);
@@ -3533,26 +3540,7 @@ Session::record_enable_change_all (bool yn)
 void
 Session::add_processor (Processor* processor)
 {
-	Send* send;
-	Return* retrn;
-	PortInsert* port_insert;
-	PluginInsert* plugin_insert;
-
-	if ((port_insert = dynamic_cast<PortInsert *> (processor)) != 0) {
-		_port_inserts.insert (_port_inserts.begin(), port_insert);
-	} else if ((plugin_insert = dynamic_cast<PluginInsert *> (processor)) != 0) {
-		_plugin_inserts.insert (_plugin_inserts.begin(), plugin_insert);
-	} else if ((send = dynamic_cast<Send *> (processor)) != 0) {
-		_sends.insert (_sends.begin(), send);
-	} else if ((retrn = dynamic_cast<Return *> (processor)) != 0) {
-		_returns.insert (_returns.begin(), retrn);
-	} else {
-		fatal << _("programming error: unknown type of Insert created!") << endmsg;
-		/*NOTREACHED*/
-	}
-
 	processor->GoingAway.connect (sigc::bind (mem_fun (*this, &Session::remove_processor), processor));
-
 	set_dirty();
 }
 
@@ -3562,31 +3550,13 @@ Session::remove_processor (Processor* processor)
 	Send* send;
 	Return* retrn;
 	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()) {
-			insert_bitset[port_insert->bit_slot()] = false;
-			_port_inserts.erase (x);
-		}
-	} else if ((plugin_insert = dynamic_cast<PluginInsert *> (processor)) != 0) {
-		_plugin_inserts.remove (plugin_insert);
+		insert_bitset[port_insert->bit_slot()] = false;
 	} else if ((send = dynamic_cast<Send *> (processor)) != 0) {
-		list<Send*>::iterator x = find (_sends.begin(), _sends.end(), send);
-		if (x != _sends.end()) {
-			send_bitset[send->bit_slot()] = false;
-			_sends.erase (x);
-		}
+		send_bitset[send->bit_slot()] = false;
 	} else if ((retrn = dynamic_cast<Return *> (processor)) != 0) {
-		list<Return*>::iterator x = find (_returns.begin(), _returns.end(), retrn);
-		if (x != _returns.end()) {
-			return_bitset[send->bit_slot()] = false;
-			_returns.erase (x);
-		}
-	} else {
-		fatal << _("programming error: unknown type of Insert deleted!") << endmsg;
-		/*NOTREACHED*/
+		return_bitset[send->bit_slot()] = false;
 	}
 
 	set_dirty();
diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index 5d622f95a7..f11342a0fd 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -153,7 +153,6 @@ Session::first_stage_init (string fullpath, string snapshot_name)
 
 	_non_soloed_outs_muted = false;
 	g_atomic_int_set (&processing_prohibited, 0);
-	insert_cnt = 0;
 	_transport_speed = 0;
 	_last_transport_speed = 0;
 	_target_transport_speed = 0;
diff --git a/libs/ardour/wscript b/libs/ardour/wscript
index 89a7e06c04..fc08dfde0d 100644
--- a/libs/ardour/wscript
+++ b/libs/ardour/wscript
@@ -136,8 +136,10 @@ def build(bld):
 		gdither.cc
 		globals.cc
 		import.cc
+                internal_return.cc
+                internal_send.cc
 		interpolation.cc
-        io.cc
+                io.cc
 		io_processor.cc
 		jack_slave.cc
 		ladspa_plugin.cc