integrate Session::remove_routes() from Tracks and replace Session::remove_route...
[ardour.git] / libs / ardour / session.cc
index 2d26cb73b45a803e9e918c484077dcb1aee31064..9df9f1940730ea15a9e300a5b9b9097b3b66dfc4 100644 (file)
 
 #include <boost/algorithm/string/erase.hpp>
 
+#include "pbd/basename.h"
+#include "pbd/boost_debug.h"
+#include "pbd/convert.h"
 #include "pbd/convert.h"
 #include "pbd/error.h"
-#include "pbd/boost_debug.h"
-#include "pbd/pathscanner.h"
-#include "pbd/stl_delete.h"
-#include "pbd/basename.h"
-#include "pbd/stacktrace.h"
 #include "pbd/file_utils.h"
-#include "pbd/convert.h"
-#include "pbd/strsplit.h"
+#include "pbd/md5.h"
+#include "pbd/search_path.h"
+#include "pbd/stacktrace.h"
+#include "pbd/stl_delete.h"
 #include "pbd/unwind.h"
 
 #include "ardour/amp.h"
 #include "ardour/control_protocol_manager.h"
 #include "ardour/data_type.h"
 #include "ardour/debug.h"
+#include "ardour/directory_names.h"
 #include "ardour/filename_extensions.h"
 #include "ardour/graph.h"
 #include "ardour/midiport_manager.h"
+#include "ardour/scene_changer.h"
 #include "ardour/midi_track.h"
 #include "ardour/midi_ui.h"
 #include "ardour/operations.h"
 #include "ardour/plugin.h"
 #include "ardour/plugin_insert.h"
 #include "ardour/process_thread.h"
+#include "ardour/profile.h"
 #include "ardour/rc_configuration.h"
 #include "ardour/recent_sessions.h"
 #include "ardour/region.h"
 #include "ardour/region_factory.h"
 #include "ardour/route_graph.h"
 #include "ardour/route_group.h"
+#include "ardour/route_sorters.h"
 #include "ardour/send.h"
 #include "ardour/session.h"
 #include "ardour/session_directory.h"
@@ -89,7 +93,9 @@
 #include "ardour/smf_source.h"
 #include "ardour/source_factory.h"
 #include "ardour/speakers.h"
+#include "ardour/tempo.h"
 #include "ardour/track.h"
+#include "ardour/user_bundle.h"
 #include "ardour/utils.h"
 
 #include "midi++/port.h"
@@ -125,6 +131,7 @@ PBD::Signal0<void> Session::FeedbackDetected;
 PBD::Signal0<void> Session::SuccessfulGraphSort;
 PBD::Signal2<void,std::string,std::string> Session::VersionMismatch;
 
+const framecnt_t Session::bounce_chunk_size = 65536;
 static void clean_up_session_event (SessionEvent* ev) { delete ev; }
 const SessionEvent::RTeventCallback Session::rt_cleanup (clean_up_session_event);
 
@@ -137,6 +144,7 @@ Session::Session (AudioEngine &eng,
        : playlists (new SessionPlaylists)
        , _engine (eng)
        , process_function (&Session::process_with_events)
+       , _bounce_processing_active (false)
        , waiting_for_sync_offset (false)
        , _base_frame_rate (0)
        , _current_frame_rate (0)
@@ -160,14 +168,13 @@ Session::Session (AudioEngine &eng,
        , _worst_input_latency (0)
        , _worst_track_latency (0)
        , _have_captured (false)
-       , _meter_hold (0)
-       , _meter_falloff (0)
        , _non_soloed_outs_muted (false)
        , _listen_cnt (0)
        , _solo_isolated_cnt (0)
        , _writable (false)
        , _was_seamless (Config->get_seamless_loop ())
        , _under_nsm_control (false)
+       , _xrun_count (0)
        , delta_accumulator_cnt (0)
        , average_slave_delta (1800) // !!! why 1800 ???
        , average_dir (0)
@@ -192,6 +199,8 @@ Session::Session (AudioEngine &eng,
        , state_tree (0)
        , state_was_pending (false)
        , _state_of_the_state (StateOfTheState(CannotSave|InitialConnecting|Loading))
+       , _suspend_save (0)
+       , _save_queued (false)
        , _last_roll_location (0)
        , _last_roll_or_reversal_location (0)
        , _last_record_location (0)
@@ -205,6 +214,9 @@ Session::Session (AudioEngine &eng,
        ,  cumulative_rf_motion (0)
        , rf_scale (1.0)
        , _locations (new Locations (*this))
+       , _ignore_skips_updates (false)
+       , _rt_thread_active (false)
+       , _rt_emit_pending (false)
        , step_speed (0)
        , outbound_mtc_timecode_frame (0)
        , next_quarter_frame_to_send (-1)
@@ -232,7 +244,9 @@ Session::Session (AudioEngine &eng,
        , _all_route_group (new RouteGroup (*this, "all"))
        , routes (new RouteList)
        , _adding_routes_in_progress (false)
+       , _route_deletion_in_progress (false)
        , destructive_index (0)
+       , _track_number_decimals(1)
        , solo_update_disabled (false)
        , default_fade_steepness (0)
        , default_fade_msecs (0)
@@ -256,16 +270,21 @@ Session::Session (AudioEngine &eng,
        , first_file_header_format_reset (true)
        , have_looped (false)
        , _have_rec_enabled_track (false)
+    , _have_rec_disabled_track (true)
        , _step_editors (0)
        , _suspend_timecode_transmission (0)
        ,  _speakers (new Speakers)
-       , _order_hint (0)
+       , _order_hint (-1)
        , ignore_route_processor_changes (false)
+       , _scene_changer (0)
        , _midi_ports (0)
        , _mmc (0)
 {
        uint32_t sr = 0;
 
+       pthread_mutex_init (&_rt_emit_mutex, 0);
+       pthread_cond_init (&_rt_emit_cond, 0);
+
        pre_engine_init (fullpath);
        
        if (_is_new) {
@@ -290,10 +309,16 @@ Session::Session (AudioEngine &eng,
                 * of a template.
                 */
 
-               if (!mix_template.empty() && load_state (_current_snapshot_name)) {
-                       throw failed_constructor ();
+               if (!mix_template.empty()) { 
+                       if (load_state (_current_snapshot_name)) {
+                               throw failed_constructor ();
+                       }
+                       store_recent_templates (mix_template);
                }
 
+               /* load default session properties - if any */
+               config.load_state();
+
        } else {
 
                if (load_state (_current_snapshot_name)) {
@@ -341,6 +366,8 @@ Session::Session (AudioEngine &eng,
 
        _is_new = false;
 
+       emit_thread_start ();
+
        /* hook us up to the engine since we are now completely constructed */
 
        BootMessage (_("Connect to engine"));
@@ -432,6 +459,10 @@ Session::immediately_post_engine ()
                return -1;
        }
 
+       /* TODO, connect in different thread. (PortRegisteredOrUnregistered may be in RT context)
+        * can we do that? */
+        _engine.PortRegisteredOrUnregistered.connect_same_thread (*this, boost::bind (&Session::setup_bundles, this));
+
        return 0;
 }
 
@@ -469,6 +500,7 @@ Session::destroy ()
        /* clear state tree so that no references to objects are held any more */
 
        delete state_tree;
+       state_tree = 0;
 
        /* reset dynamic state version back to default */
 
@@ -478,9 +510,13 @@ Session::destroy ()
        delete _butler;
        _butler = 0;
        
-       delete midi_control_ui;
        delete _all_route_group;
 
+       DEBUG_TRACE (DEBUG::Destruction, "delete route groups\n");
+       for (list<RouteGroup *>::iterator i = _route_groups.begin(); i != _route_groups.end(); ++i) {
+               delete *i;
+       }
+
        if (click_data != default_click) {
                delete [] click_data;
        }
@@ -491,6 +527,14 @@ Session::destroy ()
 
        clear_clicks ();
 
+       /* need to remove auditioner before monitoring section
+        * otherwise it is re-connected */
+       auditioner.reset ();
+
+       /* drop references to routes held by the monitoring section
+        * specifically _monitor_out aux/listen references */
+       remove_monitor_section();
+
        /* clear out any pending dead wood from RCU managed objects */
 
        routes.flush ();
@@ -510,7 +554,6 @@ Session::destroy ()
 
        /* reset these three references to special routes before we do the usual route delete thing */
 
-       auditioner.reset ();
        _master_out.reset ();
        _monitor_out.reset ();
 
@@ -539,19 +582,23 @@ Session::destroy ()
                sources.clear ();
        }
 
-       DEBUG_TRACE (DEBUG::Destruction, "delete route groups\n");
-       for (list<RouteGroup *>::iterator i = _route_groups.begin(); i != _route_groups.end(); ++i) {
-
-               delete *i;
-       }
-
        /* not strictly necessary, but doing it here allows the shared_ptr debugging to work */
        playlists.reset ();
 
+       emit_thread_terminate ();
+
+       pthread_cond_destroy (&_rt_emit_cond);
+       pthread_mutex_destroy (&_rt_emit_mutex);
+
+       delete _scene_changer; _scene_changer = 0;
+       delete midi_control_ui; midi_control_ui = 0;
+
        delete _mmc; _mmc = 0;
        delete _midi_ports; _midi_ports = 0;
        delete _locations; _locations = 0;
 
+       delete _tempo_map;
+       
        DEBUG_TRACE (DEBUG::Destruction, "Session::destroy() done\n");
 
 #ifdef BOOST_SP_ENABLE_DEBUG_HOOKS
@@ -666,6 +713,19 @@ Session::setup_click_state (const XMLNode* node)
 void
 Session::setup_bundles ()
 {
+
+       {
+               RCUWriter<BundleList> writer (_bundles);
+               boost::shared_ptr<BundleList> b = writer.get_copy ();
+               for (BundleList::iterator i = b->begin(); i != b->end();) {
+                       if (boost::dynamic_pointer_cast<UserBundle>(*i)) {
+                               ++i;
+                               continue;
+                       }
+                       i = b->erase(i);
+               }
+       }
+
        vector<string> inputs[DataType::num_types];
        vector<string> outputs[DataType::num_types];
        for (uint32_t i = 0; i < DataType::num_types; ++i) {
@@ -685,13 +745,18 @@ Session::setup_bundles ()
 
        for (uint32_t np = 0; np < outputs[DataType::AUDIO].size(); ++np) {
                char buf[32];
-               snprintf (buf, sizeof (buf), _("out %" PRIu32), np+1);
+               std::string pn = _engine.get_pretty_name_by_name (outputs[DataType::AUDIO][np]);
+               if (!pn.empty()) {
+                       snprintf (buf, sizeof (buf), _("out %s"), pn.substr(0,12).c_str());
+               } else {
+                       snprintf (buf, sizeof (buf), _("out %" PRIu32), np+1);
+               }
 
                boost::shared_ptr<Bundle> c (new Bundle (buf, true));
                c->add_channel (_("mono"), DataType::AUDIO);
                c->set_port (0, outputs[DataType::AUDIO][np]);
 
-               add_bundle (c);
+               add_bundle (c, false);
        }
 
        /* stereo output bundles */
@@ -706,7 +771,7 @@ Session::setup_bundles ()
                        c->add_channel (_("R"), DataType::AUDIO);
                        c->set_port (1, outputs[DataType::AUDIO][np + 1]);
 
-                       add_bundle (c);
+                       add_bundle (c, false);
                }
        }
 
@@ -714,13 +779,18 @@ Session::setup_bundles ()
 
        for (uint32_t np = 0; np < inputs[DataType::AUDIO].size(); ++np) {
                char buf[32];
-               snprintf (buf, sizeof (buf), _("in %" PRIu32), np+1);
+               std::string pn = _engine.get_pretty_name_by_name (inputs[DataType::AUDIO][np]);
+               if (!pn.empty()) {
+                       snprintf (buf, sizeof (buf), _("in %s"), pn.substr(0,12).c_str());
+               } else {
+                       snprintf (buf, sizeof (buf), _("in %" PRIu32), np+1);
+               }
 
                boost::shared_ptr<Bundle> c (new Bundle (buf, false));
                c->add_channel (_("mono"), DataType::AUDIO);
                c->set_port (0, inputs[DataType::AUDIO][np]);
 
-               add_bundle (c);
+               add_bundle (c, false);
        }
 
        /* stereo input bundles */
@@ -736,7 +806,7 @@ Session::setup_bundles ()
                        c->add_channel (_("R"), DataType::AUDIO);
                        c->set_port (1, inputs[DataType::AUDIO][np + 1]);
 
-                       add_bundle (c);
+                       add_bundle (c, false);
                }
        }
 
@@ -744,26 +814,36 @@ Session::setup_bundles ()
 
        for (uint32_t np = 0; np < inputs[DataType::MIDI].size(); ++np) {
                string n = inputs[DataType::MIDI][np];
-               boost::erase_first (n, X_("alsa_pcm:"));
-
+               std::string pn = _engine.get_pretty_name_by_name (n);
+               if (!pn.empty()) {
+                       n = pn;
+               } else {
+                       boost::erase_first (n, X_("alsa_pcm:"));
+               }
                boost::shared_ptr<Bundle> c (new Bundle (n, false));
                c->add_channel ("", DataType::MIDI);
                c->set_port (0, inputs[DataType::MIDI][np]);
-               add_bundle (c);
+               add_bundle (c, false);
        }
 
        /* MIDI output bundles */
 
        for (uint32_t np = 0; np < outputs[DataType::MIDI].size(); ++np) {
                string n = outputs[DataType::MIDI][np];
-               boost::erase_first (n, X_("alsa_pcm:"));
-
+               std::string pn = _engine.get_pretty_name_by_name (n);
+               if (!pn.empty()) {
+                       n = pn;
+               } else {
+                       boost::erase_first (n, X_("alsa_pcm:"));
+               }
                boost::shared_ptr<Bundle> c (new Bundle (n, true));
                c->add_channel ("", DataType::MIDI);
                c->set_port (0, outputs[DataType::MIDI][np]);
-               add_bundle (c);
+               add_bundle (c, false);
        }
 
+       // we trust the backend to only calls us if there's a change
+       BundleAddedOrRemoved (); /* EMIT SIGNAL */
 }
 
 void
@@ -861,7 +941,7 @@ Session::add_monitor_section ()
                return;
        }
 
-       boost::shared_ptr<Route> r (new Route (*this, _("monitor"), Route::MonitorOut, DataType::AUDIO));
+       boost::shared_ptr<Route> r (new Route (*this, _("Monitor"), Route::MonitorOut, DataType::AUDIO));
 
        if (r->init ()) {
                return;
@@ -1000,6 +1080,121 @@ Session::add_monitor_section ()
        }
 }
 
+void
+Session::reset_monitor_section ()
+{
+       /* Process lock should be held by the caller.*/
+
+       if (!_monitor_out) {
+               return;
+       }
+
+       uint32_t limit = _master_out->n_outputs().n_audio();
+
+       /* connect the inputs to the master bus outputs. this
+        * represents a separate data feed from the internal sends from
+        * each route. as of jan 2011, it allows the monitor section to
+        * conditionally ignore either the internal sends or the normal
+        * input feed, but we should really find a better way to do
+        * this, i think.
+        */
+
+       _master_out->output()->disconnect (this);
+       _monitor_out->output()->disconnect (this);
+
+       _monitor_out->input()->ensure_io (_master_out->output()->n_ports(), false, this);
+       _monitor_out->output()->ensure_io (_master_out->output()->n_ports(), false, this);
+
+       for (uint32_t n = 0; n < limit; ++n) {
+               boost::shared_ptr<AudioPort> p = _monitor_out->input()->ports().nth_audio_port (n);
+               boost::shared_ptr<AudioPort> o = _master_out->output()->ports().nth_audio_port (n);
+
+               if (o) {
+                       string connect_to = o->name();
+                       if (_monitor_out->input()->connect (p, connect_to, this)) {
+                               error << string_compose (_("cannot connect control input %1 to %2"), n, connect_to)
+                                     << endmsg;
+                               break;
+                       }
+               }
+       }
+
+       /* connect monitor section to physical outs
+        */
+
+       if (Config->get_auto_connect_standard_busses()) {
+
+               if (!Config->get_monitor_bus_preferred_bundle().empty()) {
+
+                       boost::shared_ptr<Bundle> b = bundle_by_name (Config->get_monitor_bus_preferred_bundle());
+
+                       if (b) {
+                               _monitor_out->output()->connect_ports_to_bundle (b, true, this);
+                       } else {
+                               warning << string_compose (_("The preferred I/O for the monitor bus (%1) cannot be found"),
+                                                          Config->get_monitor_bus_preferred_bundle())
+                                       << endmsg;
+                       }
+
+               } else {
+
+                       /* Monitor bus is audio only */
+
+                       vector<string> outputs[DataType::num_types];
+
+                       for (uint32_t i = 0; i < DataType::num_types; ++i) {
+                               _engine.get_physical_outputs (DataType (DataType::Symbol (i)), outputs[i]);
+                       }
+
+                       uint32_t mod = outputs[DataType::AUDIO].size();
+                       uint32_t limit = _monitor_out->n_outputs().get (DataType::AUDIO);
+
+                       if (mod != 0) {
+
+                               for (uint32_t n = 0; n < limit; ++n) {
+
+                                       boost::shared_ptr<Port> p = _monitor_out->output()->ports().port(DataType::AUDIO, n);
+                                       string connect_to;
+                                       if (outputs[DataType::AUDIO].size() > (n % mod)) {
+                                               connect_to = outputs[DataType::AUDIO][n % mod];
+                                       }
+
+                                       if (!connect_to.empty()) {
+                                               if (_monitor_out->output()->connect (p, connect_to, this)) {
+                                                       error << string_compose (
+                                                               _("cannot connect control output %1 to %2"),
+                                                               n, connect_to)
+                                                             << endmsg;
+                                                       break;
+                                               }
+                                       }
+                               }
+                       }
+               }
+       }
+
+       /* Connect tracks to monitor section. Note that in an
+          existing session, the internal sends will already exist, but we want the
+          routes to notice that they connect to the control out specifically.
+       */
+
+
+       boost::shared_ptr<RouteList> rls = routes.reader ();
+
+       PBD::Unwinder<bool> uw (ignore_route_processor_changes, true);
+
+       for (RouteList::iterator x = rls->begin(); x != rls->end(); ++x) {
+
+               if ((*x)->is_monitor()) {
+                       /* relax */
+               } else if ((*x)->is_master()) {
+                       /* relax */
+               } else {
+                       (*x)->enable_monitor_send ();
+               }
+       }
+}
+
 void
 Session::hookup_io ()
 {
@@ -1157,10 +1352,10 @@ Session::auto_loop_changed (Location* location)
        framepos_t dcp;
        framecnt_t dcl;
        auto_loop_declick_range (location, dcp, dcl);
-       replace_event (SessionEvent::AutoLoopDeclick, dcp, dcl);
 
        if (transport_rolling() && play_loop) {
 
+               replace_event (SessionEvent::AutoLoopDeclick, dcp, dcl);
 
                // if (_transport_frame > location->end()) {
 
@@ -1184,9 +1379,13 @@ Session::auto_loop_changed (Location* location)
                        }
 
                }
+       } else {
+               clear_events (SessionEvent::AutoLoopDeclick);
+               clear_events (SessionEvent::AutoLoop);
        }
 
        last_loopend = location->end();
+       set_dirty ();
 }
 
 void
@@ -1215,9 +1414,9 @@ Session::set_auto_punch_location (Location* location)
 
        punch_connections.drop_connections ();
 
-       location->start_changed.connect_same_thread (punch_connections, boost::bind (&Session::auto_punch_start_changed, this, _1));
-       location->end_changed.connect_same_thread (punch_connections, boost::bind (&Session::auto_punch_end_changed, this, _1));
-       location->changed.connect_same_thread (punch_connections, boost::bind (&Session::auto_punch_changed, this, _1));
+       location->StartChanged.connect_same_thread (punch_connections, boost::bind (&Session::auto_punch_start_changed, this, location));
+       location->EndChanged.connect_same_thread (punch_connections, boost::bind (&Session::auto_punch_end_changed, this, location));
+       location->Changed.connect_same_thread (punch_connections, boost::bind (&Session::auto_punch_changed, this, location));
 
        location->set_auto_punch (true, this);
 
@@ -1226,6 +1425,25 @@ Session::set_auto_punch_location (Location* location)
        auto_punch_location_changed (location);
 }
 
+void
+Session::set_session_extents (framepos_t start, framepos_t end)
+{
+       Location* existing;
+       if ((existing = _locations->session_range_location()) == 0) {
+               //if there is no existing session, we need to make a new session location  (should never happen)
+               existing = new Location (*this, 0, 0, _("session"), Location::IsSessionRange);
+       }
+       
+       if (end <= start) {
+               error << _("Session: you can't use that location for session start/end)") << endmsg;
+               return;
+       }
+
+       existing->set( start, end );
+       
+       set_dirty();
+}
+
 void
 Session::set_auto_loop_location (Location* location)
 {
@@ -1257,9 +1475,9 @@ Session::set_auto_loop_location (Location* location)
 
        loop_connections.drop_connections ();
 
-       location->start_changed.connect_same_thread (loop_connections, boost::bind (&Session::auto_loop_changed, this, _1));
-       location->end_changed.connect_same_thread (loop_connections, boost::bind (&Session::auto_loop_changed, this, _1));
-       location->changed.connect_same_thread (loop_connections, boost::bind (&Session::auto_loop_changed, this, _1));
+       location->StartChanged.connect_same_thread (loop_connections, boost::bind (&Session::auto_loop_changed, this, location));
+       location->EndChanged.connect_same_thread (loop_connections, boost::bind (&Session::auto_loop_changed, this, location));
+       location->Changed.connect_same_thread (loop_connections, boost::bind (&Session::auto_loop_changed, this, location));
 
        location->set_auto_loop (true, this);
 
@@ -1273,51 +1491,188 @@ Session::set_auto_loop_location (Location* location)
 }
 
 void
-Session::locations_added (Location *)
+Session::update_loop (Location*)
 {
        set_dirty ();
 }
 
 void
-Session::locations_changed ()
+Session::update_marks (Location*)
 {
-       _locations->apply (*this, &Session::handle_locations_changed);
+       set_dirty ();
 }
 
 void
-Session::handle_locations_changed (Locations::LocationList& locations)
+Session::update_skips (Location* loc, bool consolidate)
 {
-       Locations::LocationList::iterator i;
-       Location* location;
-       bool set_loop = false;
-       bool set_punch = false;
+    if (_ignore_skips_updates) {
+        return;
+    }
+    
+       Locations::LocationList skips;
 
-       for (i = locations.begin(); i != locations.end(); ++i) {
+        if (consolidate) {
+               PBD::Unwinder<bool> uw (_ignore_skips_updates, true);
+               consolidate_skips (loc);
+        }
 
-               location =* i;
+       sync_locations_to_skips ();
+        
+       set_dirty ();
+}
 
-               if (location->is_auto_punch()) {
-                       set_auto_punch_location (location);
-                       set_punch = true;
-               }
-               if (location->is_auto_loop()) {
-                       set_auto_loop_location (location);
-                       set_loop = true;
-               }
+void
+Session::consolidate_skips (Location* loc)
+{
+        Locations::LocationList all_locations = _locations->list ();
 
-               if (location->is_session_range()) {
-                       _session_range_location = location;
+        for (Locations::LocationList::iterator l = all_locations.begin(); l != all_locations.end(); ) {
+
+                if (!(*l)->is_skip ()) {
+                        ++l;
+                        continue;
+                }
+
+                /* don't test against self */
+
+                if (*l == loc) {
+                        ++l;
+                        continue;
+                }
+                        
+                switch (Evoral::coverage ((*l)->start(), (*l)->end(), loc->start(), loc->end())) {
+                case Evoral::OverlapInternal:
+                case Evoral::OverlapExternal:
+                case Evoral::OverlapStart:
+                case Evoral::OverlapEnd:
+                        /* adjust new location to cover existing one */
+                        loc->set_start (min (loc->start(), (*l)->start()));
+                        loc->set_end (max (loc->end(), (*l)->end()));
+                        /* we don't need this one any more */
+                        _locations->remove (*l);
+                        /* the location has been deleted, so remove reference to it in our local list */
+                        l = all_locations.erase (l);
+                        break;
+
+                case Evoral::OverlapNone:
+                        ++l;
+                        break;
+                }
+        }
+}
+
+void
+Session::sync_locations_to_skips ()
+{
+       /* This happens asynchronously (in the audioengine thread). After the clear is done, we will call
+        * Session::_sync_locations_to_skips() from the audioengine thread.
+        */
+       clear_events (SessionEvent::Skip, boost::bind (&Session::_sync_locations_to_skips, this));
+}
+
+void
+Session::_sync_locations_to_skips ()
+{
+       /* called as a callback after existing Skip events have been cleared from a realtime audioengine thread */
+
+       Locations::LocationList const & locs (_locations->list());
+
+       for (Locations::LocationList::const_iterator i = locs.begin(); i != locs.end(); ++i) {
+               
+               Location* location = *i;
+               
+               if (location->is_skip() && location->is_skipping()) {
+                       SessionEvent* ev = new SessionEvent (SessionEvent::Skip, SessionEvent::Add, location->start(), location->end(), 1.0);
+                       queue_event (ev);
                }
        }
+}
 
-       if (!set_loop) {
-               set_auto_loop_location (0);
-       }
-       if (!set_punch) {
-               set_auto_punch_location (0);
-       }
 
-       set_dirty();
+void
+Session::location_added (Location *location)
+{
+        if (location->is_auto_punch()) {
+                set_auto_punch_location (location);
+        }
+
+        if (location->is_auto_loop()) {
+                set_auto_loop_location (location);
+        }
+        
+        if (location->is_session_range()) {
+                /* no need for any signal handling or event setting with the session range,
+                   because we keep a direct reference to it and use its start/end directly.
+                */
+                _session_range_location = location;
+        }
+
+        if (location->is_mark()) {
+                /* listen for per-location signals that require us to do any * global updates for marks */
+
+                location->StartChanged.connect_same_thread (skip_update_connections, boost::bind (&Session::update_marks, this, location));
+                location->EndChanged.connect_same_thread (skip_update_connections, boost::bind (&Session::update_marks, this, location));
+                location->Changed.connect_same_thread (skip_update_connections, boost::bind (&Session::update_marks, this, location));
+                location->FlagsChanged.connect_same_thread (skip_update_connections, boost::bind (&Session::update_marks, this, location));
+        }
+
+        if (location->is_skip()) {
+                /* listen for per-location signals that require us to update skip-locate events */
+
+                location->StartChanged.connect_same_thread (skip_update_connections, boost::bind (&Session::update_skips, this, location, true));
+                location->EndChanged.connect_same_thread (skip_update_connections, boost::bind (&Session::update_skips, this, location, true));
+                location->Changed.connect_same_thread (skip_update_connections, boost::bind (&Session::update_skips, this, location, true));
+                location->FlagsChanged.connect_same_thread (skip_update_connections, boost::bind (&Session::update_skips, this, location, false));
+
+                update_skips (location, true);
+        }
+        
+       set_dirty ();
+}
+
+void
+Session::location_removed (Location *location)
+{
+        if (location->is_auto_loop()) {
+               set_auto_loop_location (0);
+               set_track_loop (false);
+        }
+        
+        if (location->is_auto_punch()) {
+                set_auto_punch_location (0);
+        }
+
+        if (location->is_session_range()) {
+                /* this is never supposed to happen */
+                error << _("programming error: session range removed!") << endl;
+        }
+
+        if (location->is_skip()) {
+                
+                update_skips (location, false);
+        }
+
+       set_dirty ();
+}
+
+void
+Session::locations_changed ()
+{
+        _locations->apply (*this, &Session::_locations_changed);
+}
+
+void
+Session::_locations_changed (const Locations::LocationList& locations)
+{
+        /* There was some mass-change in the Locations object. 
+
+           We might be re-adding a location here but it doesn't actually matter
+           for all the locations that the Session takes an interest in.
+        */
+
+       for (Locations::LocationList::const_iterator i = locations.begin(); i != locations.end(); ++i) {
+                location_added (*i);
+        }
 }
 
 void
@@ -1338,7 +1693,7 @@ Session::enable_record ()
                if (g_atomic_int_compare_and_exchange (&_record_status, rs, Recording)) {
 
                        _last_record_location = _transport_frame;
-                       _mmc->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdRecordStrobe));
+                       send_immediate_mmc (MIDI::MachineControlCommand (MIDI::MachineControl::cmdRecordStrobe));
 
                        if (Config->get_monitoring_model() == HardwareMonitoring && config.get_auto_input()) {
                                set_track_monitor_input_status (true);
@@ -1359,7 +1714,7 @@ Session::disable_record (bool rt_context, bool force)
 
                if ((!Config->get_latched_record_enable () && !play_loop) || force) {
                        g_atomic_int_set (&_record_status, Disabled);
-                       _mmc->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdRecordExit));
+                       send_immediate_mmc (MIDI::MachineControlCommand (MIDI::MachineControl::cmdRecordExit));
                } else {
                        if (rs == Recording) {
                                g_atomic_int_set (&_record_status, Enabled);
@@ -1413,7 +1768,7 @@ Session::maybe_enable_record ()
                        enable_record ();
                }
        } else {
-               _mmc->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdRecordPause));
+               send_immediate_mmc (MIDI::MachineControlCommand (MIDI::MachineControl::cmdRecordPause));
                RecordStateChanged (); /* EMIT SIGNAL */
        }
 
@@ -1427,30 +1782,10 @@ Session::audible_frame () const
        framepos_t tf;
        framecnt_t offset;
 
-       /* the first of these two possible settings for "offset"
-          mean that the audible frame is stationary until
-          audio emerges from the latency compensation
-          "pseudo-pipeline".
-
-          the second means that the audible frame is stationary
-          until audio would emerge from a physical port
-          in the absence of any plugin latency compensation
-       */
-
        offset = worst_playback_latency ();
 
-       if (offset > current_block_size) {
-               offset -= current_block_size;
-       } else {
-               /* XXX is this correct? if we have no external
-                  physical connections and everything is internal
-                  then surely this is zero? still, how
-                  likely is that anyway?
-               */
-               offset = current_block_size;
-       }
-
        if (synced_to_engine()) {
+               /* Note: this is basically just sync-to-JACK */
                tf = _engine.transport_frame();
        } else {
                tf = _transport_frame;
@@ -1874,7 +2209,12 @@ Session::new_midi_track (const ChanCount& input, const ChanCount& output, boost:
 
   failed:
        if (!new_routes.empty()) {
-               add_routes (new_routes, true, true, true);
+               StateProtector sp (this);
+               if (Profile->get_trx()) {
+                       add_routes (new_routes, false, false, false);
+               } else {
+                       add_routes (new_routes, true, true, false);
+               }
 
                if (instrument) {
                        for (RouteList::iterator r = new_routes.begin(); r != new_routes.end(); ++r) {
@@ -2029,6 +2369,51 @@ Session::auto_connect_route (boost::shared_ptr<Route> route, ChanCount& existing
        }
 }
 
+void
+Session::reconnect_existing_routes (bool withLock, bool reconnect_master, bool reconnect_inputs, bool reconnect_outputs)
+{
+        /* TRX does stuff here, ardour does not (but probably should). This is called after an engine reset (in particular).
+         */
+}
+
+#ifdef USE_TRACKS_CODE_FEATURES
+
+void
+Session::reconnect_midi_scene_ports(bool inputs)
+{
+       if (inputs) {
+               scene_in()->disconnect_all ();
+        
+               std::vector<EngineStateController::MidiPortState> midi_port_states;
+               EngineStateController::instance()->get_physical_midi_input_states (midi_port_states);
+        
+               std::vector<EngineStateController::MidiPortState>::iterator state_iter = midi_port_states.begin();
+        
+               for (; state_iter != midi_port_states.end(); ++state_iter) {
+                       if (state_iter->active && state_iter->available && state_iter->connected) {
+                               scene_in()->connect (state_iter->name);
+                       }
+               }
+
+       } else {
+               scene_out()->disconnect_all ();
+
+               std::vector<EngineStateController::MidiPortState> midi_port_states;
+               EngineStateController::instance()->get_physical_midi_output_states (midi_port_states);
+        
+               std::vector<EngineStateController::MidiPortState>::iterator state_iter = midi_port_states.begin();
+        
+               for (; state_iter != midi_port_states.end(); ++state_iter) {
+                       if (state_iter->active && state_iter->available && state_iter->connected) {
+                               scene_out()->connect (state_iter->name);
+                       }
+               }
+
+       }
+}
+
+#endif
+
 /** Caller must not hold process lock
  *  @param name_template string to use for the start of the name, or "" to use "Audio".
  */
@@ -2042,10 +2427,19 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
        RouteList new_routes;
        list<boost::shared_ptr<AudioTrack> > ret;
 
-       bool const use_number = (how_many != 1) || name_template.empty () || name_template == _("Audio");
+       string name_pattern;
 
+       if (Profile->get_trx() ) {
+               name_pattern = "Track ";
+       } else {
+               name_pattern = "Audio ";
+       }
+    
+       bool const use_number = (how_many != 1) || name_template.empty () || name_template == _(name_pattern.c_str() );
+       
        while (how_many) {
-               if (!find_route_name (name_template.empty() ? _("Audio") : name_template, ++track_id, track_name, sizeof(track_name), use_number)) {
+
+               if (!find_route_name (name_template.empty() ? _(name_pattern.c_str()) : name_template, ++track_id, track_name, sizeof(track_name), use_number)) {
                        error << "cannot find name for new audio track" << endmsg;
                        goto failed;
                }
@@ -2115,7 +2509,12 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
 
   failed:
        if (!new_routes.empty()) {
-               add_routes (new_routes, true, true, true);
+               StateProtector sp (this);
+               if (Profile->get_trx()) {
+                       add_routes (new_routes, false, false, false);
+               } else {
+                       add_routes (new_routes, true, true, false);
+               }
        }
 
        return ret;
@@ -2200,7 +2599,12 @@ Session::new_audio_route (int input_channels, int output_channels, RouteGroup* r
 
   failure:
        if (!ret.empty()) {
-               add_routes (ret, false, true, true); // autoconnect outputs only
+               StateProtector sp (this);
+               if (Profile->get_trx()) {
+                       add_routes (ret, false, false, false);
+               } else {
+                       add_routes (ret, false, true, true); // autoconnect // outputs only
+               }
        }
 
        return ret;
@@ -2255,7 +2659,7 @@ Session::new_route_from_template (uint32_t how_many, const std::string& template
                                /* generate a new name by adding a number to the end of the template name */
                                if (!find_route_name (route_name.c_str(), ++number, name, sizeof(name), true)) {
                                        fatal << _("Session: UINT_MAX routes? impossible!") << endmsg;
-                                       /*NOTREACHED*/
+                                       abort(); /*NOTREACHED*/
                                }
                        }
 
@@ -2316,7 +2720,12 @@ Session::new_route_from_template (uint32_t how_many, const std::string& template
 
   out:
        if (!ret.empty()) {
-               add_routes (ret, true, true, true);
+               StateProtector sp (this);
+               if (Profile->get_trx()) {
+                       add_routes (ret, false, false, false);
+               } else {
+                       add_routes (ret, true, true, false);
+               }
                IO::enable_connecting ();
        }
 
@@ -2345,6 +2754,10 @@ Session::add_routes (RouteList& new_routes, bool input_auto_connect, bool output
                save_state (_current_snapshot_name);
        }
        
+       reassign_track_numbers();
+
+       update_route_record_state ();
+    
        RouteAdded (new_routes); /* EMIT SIGNAL */
 }
 
@@ -2355,9 +2768,9 @@ Session::add_routes_inner (RouteList& new_routes, bool input_auto_connect, bool
         ChanCount existing_outputs;
        uint32_t order = next_control_id();
 
-       if (_order_hint != 0) {
+       if (_order_hint > -1) {
                order = _order_hint;
-               _order_hint = 0;
+               _order_hint = -1;
        }
 
         count_existing_track_channels (existing_inputs, existing_outputs);
@@ -2402,7 +2815,7 @@ Session::add_routes_inner (RouteList& new_routes, bool input_auto_connect, bool
                if (tr) {
                        tr->PlaylistChanged.connect_same_thread (*this, boost::bind (&Session::track_playlist_changed, this, boost::weak_ptr<Track> (tr)));
                        track_playlist_changed (boost::weak_ptr<Track> (tr));
-                       tr->RecordEnableChanged.connect_same_thread (*this, boost::bind (&Session::update_have_rec_enabled_track, this));
+                       tr->RecordEnableChanged.connect_same_thread (*this, boost::bind (&Session::update_route_record_state, this));
 
                        boost::shared_ptr<MidiTrack> mt = boost::dynamic_pointer_cast<MidiTrack> (tr);
                        if (mt) {
@@ -2458,7 +2871,7 @@ Session::globally_set_send_gains_to_zero (boost::shared_ptr<Route> dest)
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
                if ((s = (*i)->internal_send_for (dest)) != 0) {
-                       s->amp()->gain_control()->set_value (0.0);
+                       s->amp()->gain_control()->set_value (GAIN_COEFF_ZERO);
                }
        }
 }
@@ -2471,7 +2884,7 @@ Session::globally_set_send_gains_to_unity (boost::shared_ptr<Route> dest)
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
                if ((s = (*i)->internal_send_for (dest)) != 0) {
-                       s->amp()->gain_control()->set_value (1.0);
+                       s->amp()->gain_control()->set_value (GAIN_COEFF_UNITY);
                }
        }
 }
@@ -2536,92 +2949,128 @@ Session::add_internal_send (boost::shared_ptr<Route> dest, boost::shared_ptr<Pro
        graph_reordered ();
 }
 
+
 void
-Session::remove_route (boost::shared_ptr<Route> route)
+Session::remove_routes (boost::shared_ptr<RouteList> routes_to_remove)
 {
-       if (route == _master_out) {
-               return;
-       }
-
-       route->set_solo (false, this);
-
-       {
+       { // RCU Writer scope
                RCUWriter<RouteList> writer (routes);
                boost::shared_ptr<RouteList> rs = writer.get_copy ();
+        
+        
+               for (RouteList::iterator iter = routes_to_remove->begin(); iter != routes_to_remove->end(); ++iter) {
+            
+                       if (*iter == _master_out) {
+                               continue;
+                       }
+            
+                       (*iter)->set_solo (false, this);
+            
+                       rs->remove (*iter);
+            
+                       /* deleting the master out seems like a dumb
+                          idea, but its more of a UI policy issue
+                          than our concern.
+                       */
+            
+                       if (*iter == _master_out) {
+                               _master_out = boost::shared_ptr<Route> ();
+                       }
+            
+                       if (*iter == _monitor_out) {
+                               _monitor_out.reset ();
+                       }
 
-               rs->remove (route);
-
-               /* deleting the master out seems like a dumb
-                  idea, but its more of a UI policy issue
-                  than our concern.
-               */
-
-               if (route == _master_out) {
-                       _master_out = boost::shared_ptr<Route> ();
-               }
-
-               if (route == _monitor_out) {
-                       _monitor_out.reset ();
-               }
-
-               /* writer goes out of scope, forces route list update */
-       }
-
-       update_route_solo_state ();
-
-       // We need to disconnect the route's inputs and outputs
-
-       route->input()->disconnect (0);
-       route->output()->disconnect (0);
-
-       /* if the route had internal sends sending to it, remove them */
-       if (route->internal_return()) {
-
-               boost::shared_ptr<RouteList> r = routes.reader ();
-               for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-                       boost::shared_ptr<Send> s = (*i)->internal_send_for (route);
-                       if (s) {
-                               (*i)->remove_processor (s);
+                       update_route_solo_state ();
+            
+                       // We need to disconnect the route's inputs and outputs
+            
+                       (*iter)->input()->disconnect (0);
+                       (*iter)->output()->disconnect (0);
+            
+                       /* if the route had internal sends sending to it, remove them */
+                       if ((*iter)->internal_return()) {
+                
+                               boost::shared_ptr<RouteList> r = routes.reader ();
+                               for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+                                       boost::shared_ptr<Send> s = (*i)->internal_send_for (*iter);
+                                       if (s) {
+                                               (*i)->remove_processor (s);
+                                       }
+                               }
+                       }
+            
+                       /* if the monitoring section had a pointer to this route, remove it */
+                       if (_monitor_out && !(*iter)->is_master() && !(*iter)->is_monitor()) {
+                               Glib::Threads::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
+                               PBD::Unwinder<bool> uw (ignore_route_processor_changes, true);
+                               (*iter)->remove_aux_or_listen (_monitor_out);
+                       }
+            
+                       boost::shared_ptr<MidiTrack> mt = boost::dynamic_pointer_cast<MidiTrack> (*iter);
+                       if (mt && mt->step_editing()) {
+                               if (_step_editors > 0) {
+                                       _step_editors--;
+                               }
                        }
-               }
-       }
 
-       boost::shared_ptr<MidiTrack> mt = boost::dynamic_pointer_cast<MidiTrack> (route);
-       if (mt && mt->step_editing()) {
-               if (_step_editors > 0) {
-                       _step_editors--;
+                       RouteAddedOrRemoved (false); /* EMIT SIGNAL */
                }
-       }
+    
+               /* writer goes out of scope, forces route list update */
 
+       } // end of RCU Writer scope
+    
        update_latency_compensation ();
        set_dirty();
-
+    
        /* Re-sort routes to remove the graph's current references to the one that is
         * going away, then flush old references out of the graph.
+        * Wave Tracks: reconnect routes
         */
 
-       resort_routes ();
+       if (ARDOUR::Profile->get_trx () ) {
+               reconnect_existing_routes(true, false);
+       } else {
+               resort_routes ();
+       }
+    
        if (_process_graph) {
                _process_graph->clear_other_chain ();
        }
-
+    
        /* get rid of it from the dead wood collection in the route list manager */
-
        /* XXX i think this is unsafe as it currently stands, but i am not sure. (pd, october 2nd, 2006) */
-
+    
        routes.flush ();
+    
+       /* try to cause everyone to drop their references
+        * and unregister ports from the backend
+        */
+       PBD::Unwinder<bool> uw_flag (_route_deletion_in_progress, true);
 
-       /* try to cause everyone to drop their references */
-
-       route->drop_references ();
-
+       for (RouteList::iterator iter = routes_to_remove->begin(); iter != routes_to_remove->end(); ++iter) {
+               (*iter)->drop_references ();
+       }
+    
        Route::RemoteControlIDChange(); /* EMIT SIGNAL */
-
+    
        /* save the new state of the world */
-
+    
        if (save_state (_current_snapshot_name)) {
                save_history (_current_snapshot_name);
        }
+
+       reassign_track_numbers();
+       update_route_record_state ();
+}
+
+void
+Session::remove_route (boost::shared_ptr<Route> route)
+{
+       boost::shared_ptr<RouteList> rl (new RouteList);
+       rl->push_back (route);
+       remove_routes (rl);
 }
 
 void
@@ -2815,6 +3264,7 @@ Session::route_solo_changed (bool self_solo_change, void* /*src*/, boost::weak_p
 
        for (RouteList::iterator i = uninvolved.begin(); i != uninvolved.end(); ++i) {
                DEBUG_TRACE (DEBUG::Solo, string_compose ("mute change for %1, which neither feeds or is fed by %2\n", (*i)->name(), route->name()));
+               (*i)->act_on_mute ();
                (*i)->mute_changed (this);
        }
 
@@ -3038,6 +3488,42 @@ Session::route_by_remote_id (uint32_t id)
        return boost::shared_ptr<Route> ((Route*) 0);
 }
 
+
+void
+Session::reassign_track_numbers ()
+{
+       int64_t tn = 0;
+       int64_t bn = 0;
+       RouteList r (*(routes.reader ()));
+       SignalOrderRouteSorter sorter;
+       r.sort (sorter);
+
+       StateProtector sp (this);
+
+       for (RouteList::iterator i = r.begin(); i != r.end(); ++i) {
+               if (boost::dynamic_pointer_cast<Track> (*i)) {
+                       (*i)->set_track_number(++tn);
+               }
+               else if (!(*i)->is_master() && !(*i)->is_monitor() && !(*i)->is_auditioner()) {
+                       (*i)->set_track_number(--bn);
+               }
+       }
+       const uint32_t decimals = ceilf (log10f (tn + 1));
+       const bool decimals_changed = _track_number_decimals != decimals;
+       _track_number_decimals = decimals;
+
+       if (decimals_changed && config.get_track_name_number ()) {
+               for (RouteList::iterator i = r.begin(); i != r.end(); ++i) {
+                       boost::shared_ptr<Track> t = boost::dynamic_pointer_cast<Track> (*i);
+                       if (t) {
+                               t->resync_track_name();
+                       }
+               }
+               // trigger GUI re-layout
+               config.ParameterChanged("track-name-number");
+       }
+}
+
 void
 Session::playlist_region_added (boost::weak_ptr<Region> w)
 {
@@ -3281,7 +3767,7 @@ Session::remove_source (boost::weak_ptr<Source> src)
                }
        }
 
-       if (!(_state_of_the_state & InCleanup)) {
+       if (!(_state_of_the_state & StateOfTheState (InCleanup|Loading))) {
 
                /* save state so we don't end up with a session file
                   referring to non-existent sources.
@@ -3370,96 +3856,221 @@ Session::count_sources_by_origin (const string& path)
 string
 Session::peak_path (string base) const
 {
+       if (Glib::path_is_absolute (base)) {
+
+               /* rip the session dir from the audiofile source */
+
+               string session_path;
+               string interchange_dir_string = string (interchange_dir_name) + G_DIR_SEPARATOR;
+               bool in_another_session = true;
+               
+               if (base.find (interchange_dir_string) != string::npos) {
+               
+                       session_path = Glib::path_get_dirname (base); /* now ends in audiofiles */
+                       session_path = Glib::path_get_dirname (session_path); /* now ends in session name */
+                       session_path = Glib::path_get_dirname (session_path); /* now ends in interchange */
+                       session_path = Glib::path_get_dirname (session_path); /* now has session path */
+
+                       /* see if it is within our session */
+
+                       for (vector<space_and_path>::const_iterator i = session_dirs.begin(); i != session_dirs.end(); ++i) {
+                               if (i->path == session_path) {
+                                       in_another_session = false;
+                                       break;
+                               }
+                       }
+               } else {
+                       in_another_session = false;
+               }
+               
+
+               if (in_another_session) {
+                       SessionDirectory sd (session_path);
+                       return Glib::build_filename (sd.peak_path(), Glib::path_get_basename (base) + peakfile_suffix);
+               }
+       }
+
+       base = Glib::path_get_basename (base);
        return Glib::build_filename (_session_dir->peak_path(), base + peakfile_suffix);
 }
 
-/** Return a unique name based on \a base for a new internal audio source */
 string
-Session::new_audio_source_path (const string& base, uint32_t nchan, uint32_t chan, bool destructive, bool take_required)
+Session::new_audio_source_path_for_embedded (const std::string& path)
 {
-       uint32_t cnt;
-       string possible_name;
-       const uint32_t limit = 9999; // arbitrary limit on number of files with the same basic name
-       string legalized;
-       string ext = native_header_format_extension (config.get_native_file_header_format(), DataType::AUDIO);
-       bool some_related_source_name_exists = false;
+       /* embedded source: 
+        *
+        * we know that the filename is already unique because it exists
+        * out in the filesystem. 
+        *
+        * However, when we bring it into the session, we could get a
+        * collision.
+        *
+        * Eg. two embedded files:
+        * 
+        *          /foo/bar/baz.wav
+        *          /frob/nic/baz.wav
+        *
+        * When merged into session, these collide. 
+        *
+        * There will not be a conflict with in-memory sources
+        * because when the source was created we already picked
+        * a unique name for it.
+        *
+        * This collision is not likely to be common, but we have to guard
+        * against it.  So, if there is a collision, take the md5 hash of the
+        * the path, and use that as the filename instead.
+        */
 
-       possible_name[0] = '\0';
-       legalized = legalize_for_path (base);
+       SessionDirectory sdir (get_best_session_directory_for_new_audio());
+       string base = Glib::path_get_basename (path);
+       string newpath = Glib::build_filename (sdir.sound_path(), base);
+       
+       if (Glib::file_test (newpath, Glib::FILE_TEST_EXISTS)) {
 
-       // Find a "version" of the base name that doesn't exist in any of the possible directories.
+               MD5 md5;
 
-       for (cnt = (destructive ? ++destructive_index : 1); cnt <= limit; ++cnt) {
+               md5.digestString (path.c_str());
+               md5.writeToString ();
+               base = md5.digestChars;
+               
+               string ext = get_suffix (path);
 
-               vector<space_and_path>::iterator i;
-               uint32_t existing = 0;
+               if (!ext.empty()) {
+                       base += '.';
+                       base += ext;
+               }
+               
+               newpath = Glib::build_filename (sdir.sound_path(), base);
 
-               for (i = session_dirs.begin(); i != session_dirs.end(); ++i) {
+               /* if this collides, we're screwed */
 
-                       ostringstream sstr;
+               if (Glib::file_test (newpath, Glib::FILE_TEST_EXISTS)) {
+                       error << string_compose (_("Merging embedded file %1: name collision AND md5 hash collision!"), path) << endmsg;
+                       return string();
+               }
 
-                       if (destructive) {
-                               sstr << 'T';
-                               sstr << setfill ('0') << setw (4) << cnt;
-                               sstr << legalized;
-                       } else {
-                               sstr << legalized;
-                               
-                               if (take_required || some_related_source_name_exists) {
-                                       sstr << '-';
-                                       sstr << cnt;
-                               }
-                       }
-                       
-                       if (nchan == 2) {
-                               if (chan == 0) {
-                                       sstr << "%L";
-                               } else {
-                                       sstr << "%R";
-                               }
-                       } else if (nchan > 2 && nchan < 26) {
-                               sstr << '%';
-                               sstr << 'a' + chan;
-                       } 
+       }
 
-                       sstr << ext;
+       return newpath;
+}
 
-                       possible_name = sstr.str();
-                       SessionDirectory sdir((*i).path);
-                       const string spath = sdir.sound_path();
+/** Return true if there are no audio file sources that use @param name as 
+ * the filename component of their path. 
+ *
+ * Return false otherwise.
+ *
+ * This method MUST ONLY be used to check in-session, mono files since it 
+ * hard-codes the channel of the audio file source we are looking for as zero.
+ * 
+ * If/when Ardour supports native files in non-mono formats, the logic here
+ * will need to be revisited.
+ */
+bool
+Session::audio_source_name_is_unique (const string& name)
+{
+       std::vector<string> sdirs = source_search_path (DataType::AUDIO);
+       vector<space_and_path>::iterator i;
+       uint32_t existing = 0;
 
-                       /* note that we search *without* the extension so that
-                          we don't end up both "Audio 1-1.wav" and "Audio 1-1.caf"
-                          in the event that this new name is required for
-                          a file format change.
-                       */
+       for (vector<string>::const_iterator i = sdirs.begin(); i != sdirs.end(); ++i) {
+               
+               /* note that we search *without* the extension so that
+                  we don't end up both "Audio 1-1.wav" and "Audio 1-1.caf"
+                  in the event that this new name is required for
+                  a file format change.
+               */
 
-                       if (matching_unsuffixed_filename_exists_in (spath, possible_name)) {
-                               existing++;
-                               break;
-                       }
+               const string spath = *i;
+               
+               if (matching_unsuffixed_filename_exists_in (spath, name)) {
+                       existing++;
+                       break;
+               }
+               
+               /* it is possible that we have the path already
+                * assigned to a source that has not yet been written
+                * (ie. the write source for a diskstream). we have to
+                * check this in order to make sure that our candidate
+                * path isn't used again, because that can lead to
+                * two Sources point to the same file with different
+                * notions of their removability.
+                */
+               
+               
+               string possible_path = Glib::build_filename (spath, name);
 
-                       /* it is possible that we have the path already
-                        * assigned to a source that has not yet been written
-                        * (ie. the write source for a diskstream). we have to
-                        * check this in order to make sure that our candidate
-                        * path isn't used again, because that can lead to
-                        * two Sources point to the same file with different
-                        * notions of their removability.
-                        */
+               if (audio_source_by_path_and_channel (possible_path, 0)) {
+                       existing++;
+                       break;
+               }
+       }
 
-                       string possible_path = Glib::build_filename (spath, possible_name);
+       return (existing == 0);
+}
 
-                       if (audio_source_by_path_and_channel (possible_path, chan)) {
-                               existing++;
-                               break;
-                       }
+string
+Session::format_audio_source_name (const string& legalized_base, uint32_t nchan, uint32_t chan, bool destructive, bool take_required, uint32_t cnt, bool related_exists)
+{
+       ostringstream sstr;
+       const string ext = native_header_format_extension (config.get_native_file_header_format(), DataType::AUDIO);
+       
+       if (destructive) {
+               sstr << 'T';
+               sstr << setfill ('0') << setw (4) << cnt;
+               sstr << legalized_base;
+       } else {
+               sstr << legalized_base;
+               
+               if (take_required || related_exists) {
+                       sstr << '-';
+                       sstr << cnt;
+               }
+       }
+       
+       if (nchan == 2) {
+               if (chan == 0) {
+                       sstr << "%L";
+               } else {
+                       sstr << "%R";
+               }
+       } else if (nchan > 2) {
+               if (nchan < 26) {
+                       sstr << '%';
+                       sstr << 'a' + chan;
+               } else {
+                       /* XXX what? more than 26 channels! */
+                       sstr << '%';
+                       sstr << chan+1;
                }
+       }
+       
+       sstr << ext;
 
-               if (existing == 0) {
+       return sstr.str();
+}
+
+/** Return a unique name based on \a base for a new internal audio source */
+string
+Session::new_audio_source_path (const string& base, uint32_t nchan, uint32_t chan, bool destructive, bool take_required)
+{
+       uint32_t cnt;
+       string possible_name;
+       const uint32_t limit = 9999; // arbitrary limit on number of files with the same basic name
+       string legalized;
+       bool some_related_source_name_exists = false;
+
+       legalized = legalize_for_path (base);
+
+       // Find a "version" of the base name that doesn't exist in any of the possible directories.
+
+       for (cnt = (destructive ? ++destructive_index : 1); cnt <= limit; ++cnt) {
+
+               possible_name = format_audio_source_name (legalized, nchan, chan, destructive, take_required, cnt, some_related_source_name_exists);
+               
+               if (audio_source_name_is_unique (possible_name)) {
                        break;
                }
-
+               
                some_related_source_name_exists = true;
 
                if (cnt > limit) {
@@ -3483,7 +4094,7 @@ Session::new_audio_source_path (const string& base, uint32_t nchan, uint32_t cha
        return s;
 }
 
-/** Return a unique name based on \a owner_name for a new internal MIDI source */
+/** Return a unique name based on `base` for a new internal MIDI source */
 string
 Session::new_midi_source_path (const string& base)
 {
@@ -3498,20 +4109,29 @@ Session::new_midi_source_path (const string& base)
        legalized = legalize_for_path (base);
 
        // Find a "version" of the file name that doesn't exist in any of the possible directories.
+       std::vector<string> sdirs = source_search_path(DataType::MIDI);
+
+       /* - the main session folder is the first in the vector.
+        * - after checking all locations for file-name uniqueness,
+        *   we keep the one from the last iteration as new file name
+        * - midi files are small and should just be kept in the main session-folder
+        *
+        * -> reverse the array, check main session folder last and use that as location
+        *    for MIDI files.
+        */
+       std::reverse(sdirs.begin(), sdirs.end());
 
        for (cnt = 1; cnt <= limit; ++cnt) {
 
                vector<space_and_path>::iterator i;
                uint32_t existing = 0;
                
-               for (i = session_dirs.begin(); i != session_dirs.end(); ++i) {
+               for (vector<string>::const_iterator i = sdirs.begin(); i != sdirs.end(); ++i) {
 
-                       SessionDirectory sdir((*i).path);
-                       
                        snprintf (buf, sizeof(buf), "%s-%u.mid", legalized.c_str(), cnt);
                        possible_name = buf;
 
-                       possible_path = Glib::build_filename (sdir.midi_path(), possible_name);
+                       possible_path = Glib::build_filename (*i, possible_name);
                        
                        if (Glib::file_test (possible_path, Glib::FILE_TEST_EXISTS)) {
                                existing++;
@@ -3685,6 +4305,9 @@ Session::audition_region (boost::shared_ptr<Region> r)
 void
 Session::cancel_audition ()
 {
+       if (!auditioner) {
+               return;
+       }
        if (auditioner->auditioning()) {
                auditioner->cancel_audition ();
                AuditionActive (false); /* EMIT SIGNAL */
@@ -3778,7 +4401,7 @@ Session::available_capture_duration ()
                fatal << string_compose (_("programming error: %1"),
                                         X_("illegal native file data format"))
                      << endmsg;
-               /*NOTREACHED*/
+               abort(); /*NOTREACHED*/
        }
 
        double scale = 4096.0 / sample_bytes_on_disk;
@@ -3791,7 +4414,7 @@ Session::available_capture_duration ()
 }
 
 void
-Session::add_bundle (boost::shared_ptr<Bundle> bundle)
+Session::add_bundle (boost::shared_ptr<Bundle> bundle, bool emit_signal)
 {
        {
                RCUWriter<BundleList> writer (_bundles);
@@ -3799,7 +4422,9 @@ Session::add_bundle (boost::shared_ptr<Bundle> bundle)
                b->push_back (bundle);
        }
 
-       BundleAdded (bundle); /* EMIT SIGNAL */
+       if (emit_signal) {
+               BundleAddedOrRemoved (); /* EMIT SIGNAL */
+       }
 
        set_dirty();
 }
@@ -3821,7 +4446,7 @@ Session::remove_bundle (boost::shared_ptr<Bundle> bundle)
        }
 
        if (removed) {
-                BundleRemoved (bundle); /* EMIT SIGNAL */
+                BundleAddedOrRemoved (); /* EMIT SIGNAL */
        }
 
        set_dirty();
@@ -3854,9 +4479,9 @@ Session::tempo_map_changed (const PropertyChange&)
 }
 
 void
-Session::update_locations_after_tempo_map_change (Locations::LocationList& loc)
+Session::update_locations_after_tempo_map_change (const Locations::LocationList& loc)
 {
-       for (Locations::LocationList::iterator i = loc.begin(); i != loc.end(); ++i) {
+       for (Locations::LocationList::const_iterator i = loc.begin(); i != loc.end(); ++i) {
                (*i)->recompute_frames_from_bbt ();
        }
 }
@@ -3867,7 +4492,7 @@ Session::update_locations_after_tempo_map_change (Locations::LocationList& loc)
 void
 Session::ensure_buffers (ChanCount howmany)
 {
-       BufferManager::ensure_buffers (howmany);
+       BufferManager::ensure_buffers (howmany, bounce_processing() ? bounce_chunk_size : 0);
 }
 
 void
@@ -4104,23 +4729,26 @@ Session::freeze_all (InterThreadInfo& itt)
 }
 
 boost::shared_ptr<Region>
-Session::write_one_track (AudioTrack& track, framepos_t start, framepos_t end,
+Session::write_one_track (Track& track, framepos_t start, framepos_t end,
                          bool /*overwrite*/, vector<boost::shared_ptr<Source> >& srcs,
                          InterThreadInfo& itt, 
                          boost::shared_ptr<Processor> endpoint, bool include_endpoint,
-                         bool for_export)
+                         bool for_export, bool for_freeze)
 {
        boost::shared_ptr<Region> result;
        boost::shared_ptr<Playlist> playlist;
-       boost::shared_ptr<AudioFileSource> fsource;
+       boost::shared_ptr<Source> source;
        ChanCount diskstream_channels (track.n_channels());
        framepos_t position;
        framecnt_t this_chunk;
        framepos_t to_do;
+       framepos_t latency_skip;
        BufferSet buffers;
        framepos_t len = end - start;
        bool need_block_size_reset = false;
        ChanCount const max_proc = track.max_processor_streams ();
+       string legal_playlist_name;
+       string possible_path;
 
        if (end <= start) {
                error << string_compose (_("Cannot write a range where end <= start (e.g. %1 <= %2)"),
@@ -4128,38 +4756,57 @@ Session::write_one_track (AudioTrack& track, framepos_t start, framepos_t end,
                return result;
        }
 
-       const framecnt_t chunk_size = (256 * 1024)/4;
+       diskstream_channels = track.bounce_get_output_streams (diskstream_channels, endpoint,
+                       include_endpoint, for_export, for_freeze);
+
+       if (diskstream_channels.n(track.data_type()) < 1) {
+               error << _("Cannot write a range with no data.") << endmsg;
+               return result;
+       }
 
        // block all process callback handling
 
        block_processing ();
 
+       {
+               // synchronize with AudioEngine::process_callback()
+               // make sure processing is not currently running
+               // and processing_blocked() is honored before
+               // acquiring thread buffers
+               Glib::Threads::Mutex::Lock lm (_engine.process_lock());
+       }
+
+       _bounce_processing_active = true;
+
        /* call tree *MUST* hold route_lock */
 
        if ((playlist = track.playlist()) == 0) {
                goto out;
        }
 
-       for (uint32_t chan_n = 0; chan_n < diskstream_channels.n_audio(); ++chan_n) {
+       legal_playlist_name = legalize_for_path (playlist->name());
+
+       for (uint32_t chan_n = 0; chan_n < diskstream_channels.n(track.data_type()); ++chan_n) {
 
                string base_name = string_compose ("%1-%2-bounce", playlist->name(), chan_n);
-               string path = new_audio_source_path (base_name, diskstream_channels.n_audio(), chan_n, false, true);
+               string path = ((track.data_type() == DataType::AUDIO)
+                              ? new_audio_source_path (legal_playlist_name, diskstream_channels.n_audio(), chan_n, false, true)
+                              : new_midi_source_path (legal_playlist_name));
                
                if (path.empty()) {
                        goto out;
                }
 
                try {
-                       fsource = boost::dynamic_pointer_cast<AudioFileSource> (
-                               SourceFactory::createWritable (DataType::AUDIO, *this, path, false, frame_rate()));
+                       source = SourceFactory::createWritable (track.data_type(), *this, path, false, frame_rate());
                }
 
                catch (failed_constructor& err) {
-                       error << string_compose (_("cannot create new audio file \"%1\" for %2"), path, track.name()) << endmsg;
+                       error << string_compose (_("cannot create new file \"%1\" for %2"), path, track.name()) << endmsg;
                        goto out;
                }
 
-               srcs.push_back (fsource);
+               srcs.push_back (source);
        }
 
        /* tell redirects that care that we are about to use a much larger
@@ -4168,45 +4815,92 @@ Session::write_one_track (AudioTrack& track, framepos_t start, framepos_t end,
         */
 
        need_block_size_reset = true;
-       track.set_block_size (chunk_size);
+       track.set_block_size (bounce_chunk_size);
+       _engine.main_thread()->get_buffers ();
 
        position = start;
        to_do = len;
+       latency_skip = track.bounce_get_latency (endpoint, include_endpoint, for_export, for_freeze);
 
        /* create a set of reasonably-sized buffers */
-       buffers.ensure_buffers (DataType::AUDIO, max_proc.n_audio(), chunk_size);
+       for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
+               buffers.ensure_buffers(*t, max_proc.get(*t), bounce_chunk_size);
+       }
        buffers.set_count (max_proc);
 
        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)
+               boost::shared_ptr<MidiSource> ms;
+               if (afs) {
                        afs->prepare_for_peakfile_writes ();
+               } else if ((ms = boost::dynamic_pointer_cast<MidiSource>(*src))) {
+                       Source::Lock lock(ms->mutex());
+                       ms->mark_streaming_write_started(lock);
+               }
        }
 
        while (to_do && !itt.cancel) {
 
-               this_chunk = min (to_do, chunk_size);
+               this_chunk = min (to_do, bounce_chunk_size);
 
-               if (track.export_stuff (buffers, start, this_chunk, endpoint, include_endpoint, for_export)) {
+               if (track.export_stuff (buffers, start, this_chunk, endpoint, include_endpoint, for_export, for_freeze)) {
                        goto out;
                }
 
+               start += this_chunk;
+               to_do -= this_chunk;
+               itt.progress = (float) (1.0 - ((double) to_do / len));
+
+               if (latency_skip >= bounce_chunk_size) {
+                       latency_skip -= bounce_chunk_size;
+                       continue;
+               }
+
+               const framecnt_t current_chunk = this_chunk - latency_skip;
+
                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);
+                       boost::shared_ptr<MidiSource> ms;
 
                        if (afs) {
-                               if (afs->write (buffers.get_audio(n).data(), this_chunk) != this_chunk) {
+                               if (afs->write (buffers.get_audio(n).data(latency_skip), current_chunk) != current_chunk) {
                                        goto out;
                                }
+                       } else if ((ms = boost::dynamic_pointer_cast<MidiSource>(*src))) {
+                               Source::Lock lock(ms->mutex());
+
+                               const MidiBuffer& buf = buffers.get_midi(0);
+                               for (MidiBuffer::const_iterator i = buf.begin(); i != buf.end(); ++i) {
+                                       Evoral::Event<framepos_t> ev = *i;
+                                       ev.set_time(ev.time() - position);
+                                       ms->append_event_frames(lock, ev, ms->timeline_position());
+                               }
                        }
                }
+               latency_skip = 0;
+       }
 
-               start += this_chunk;
-               to_do -= this_chunk;
+       /* post-roll, pick up delayed processor output */
+       latency_skip = track.bounce_get_latency (endpoint, include_endpoint, for_export, for_freeze);
 
-               itt.progress = (float) (1.0 - ((double) to_do / len));
+       while (latency_skip && !itt.cancel) {
+               this_chunk = min (latency_skip, bounce_chunk_size);
+               latency_skip -= this_chunk;
+
+               buffers.silence (this_chunk, 0);
+               track.bounce_process (buffers, start, this_chunk, endpoint, include_endpoint, for_export, for_freeze);
+
+               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;
+                               }
+                       }
+               }
        }
 
        if (!itt.cancel) {
@@ -4218,10 +4912,14 @@ Session::write_one_track (AudioTrack& track, framepos_t start, framepos_t end,
 
                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);
+                       boost::shared_ptr<MidiSource> ms;
 
                        if (afs) {
                                afs->update_header (position, *xnow, now);
                                afs->flush_header ();
+                       } else if ((ms = boost::dynamic_pointer_cast<MidiSource>(*src))) {
+                               Source::Lock lock(ms->mutex());
+                               ms->mark_streaming_write_completed(lock);
                        }
                }
 
@@ -4240,12 +4938,7 @@ Session::write_one_track (AudioTrack& track, framepos_t start, framepos_t end,
   out:
        if (!result) {
                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->mark_for_remove ();
-                       }
-
+                       (*src)->mark_for_remove ();
                        (*src)->drop_references ();
                }
 
@@ -4258,8 +4951,10 @@ Session::write_one_track (AudioTrack& track, framepos_t start, framepos_t end,
                }
        }
 
+       _bounce_processing_active = false;
 
        if (need_block_size_reset) {
+               _engine.main_thread()->drop_buffers ();
                track.set_block_size (get_block_size());
        }
 
@@ -4274,6 +4969,12 @@ Session::gain_automation_buffer() const
        return ProcessThread::gain_automation_buffer ();
 }
 
+gain_t*
+Session::trim_automation_buffer() const
+{
+       return ProcessThread::trim_automation_buffer ();
+}
+
 gain_t*
 Session::send_gain_automation_buffer() const
 {
@@ -4354,9 +5055,15 @@ Session::have_rec_enabled_track () const
        return g_atomic_int_get (const_cast<gint*>(&_have_rec_enabled_track)) == 1;
 }
 
+bool
+Session::have_rec_disabled_track () const
+{
+    return g_atomic_int_get (const_cast<gint*>(&_have_rec_disabled_track)) == 1;
+}
+
 /** Update the state of our rec-enabled tracks flag */
 void
-Session::update_have_rec_enabled_track ()
+Session::update_route_record_state ()
 {
        boost::shared_ptr<RouteList> rl = routes.reader ();
        RouteList::iterator i = rl->begin();
@@ -4377,6 +5084,20 @@ Session::update_have_rec_enabled_track ()
        if (g_atomic_int_get (&_have_rec_enabled_track) != old) {
                RecordStateChanged (); /* EMIT SIGNAL */
        }
+
+    
+    i = rl->begin();
+       while (i != rl->end ()) {
+        
+               boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
+               if (tr && !tr->record_enabled ()) {
+                       break;
+               }
+        
+               ++i;
+       }
+    
+    g_atomic_int_set (&_have_rec_disabled_track, i != rl->end () ? 1 : 0);
 }
 
 void
@@ -4419,7 +5140,24 @@ Session::route_added_to_route_group (RouteGroup* rg, boost::weak_ptr<Route> r)
 void
 Session::route_removed_from_route_group (RouteGroup* rg, boost::weak_ptr<Route> r)
 {
-       RouteRemovedFromRouteGroup (rg, r);
+       update_route_record_state ();
+       RouteRemovedFromRouteGroup (rg, r); /* EMIT SIGNAL */
+}
+
+boost::shared_ptr<RouteList>
+Session::get_tracks () const
+{
+       boost::shared_ptr<RouteList> rl = routes.reader ();
+       boost::shared_ptr<RouteList> tl (new RouteList);
+
+       for (RouteList::const_iterator r = rl->begin(); r != rl->end(); ++r) {
+               if (boost::dynamic_pointer_cast<Track> (*r)) {
+                       if (!(*r)->is_auditioner()) {
+                               tl->push_back (*r);
+                       }
+               }
+       }
+       return tl;
 }
 
 boost::shared_ptr<RouteList>
@@ -4550,18 +5288,18 @@ Session::end_time_changed (framepos_t old)
        }
 }
 
-string
+std::vector<std::string>
 Session::source_search_path (DataType type) const
 {
-       vector<string> s;
+       Searchpath sp;
 
        if (session_dirs.size() == 1) {
                switch (type) {
                case DataType::AUDIO:
-                       s.push_back (_session_dir->sound_path());
+                       sp.push_back (_session_dir->sound_path());
                        break;
                case DataType::MIDI:
-                       s.push_back (_session_dir->midi_path());
+                       sp.push_back (_session_dir->midi_path());
                        break;
                }
        } else {
@@ -4569,10 +5307,10 @@ Session::source_search_path (DataType type) const
                        SessionDirectory sdir (i->path);
                        switch (type) {
                        case DataType::AUDIO:
-                               s.push_back (sdir.sound_path());
+                               sp.push_back (sdir.sound_path());
                                break;
                        case DataType::MIDI:
-                               s.push_back (sdir.midi_path());
+                               sp.push_back (sdir.midi_path());
                                break;
                        }
                }
@@ -4581,49 +5319,30 @@ Session::source_search_path (DataType type) const
        if (type == DataType::AUDIO) {
                const string sound_path_2X = _session_dir->sound_path_2X();
                if (Glib::file_test (sound_path_2X, Glib::FILE_TEST_EXISTS|Glib::FILE_TEST_IS_DIR)) {
-                       if (find (s.begin(), s.end(), sound_path_2X) == s.end()) {
-                               s.push_back (sound_path_2X);
+                       if (find (sp.begin(), sp.end(), sound_path_2X) == sp.end()) {
+                               sp.push_back (sound_path_2X);
                        }
                }
        }
 
-       /* now check the explicit (possibly user-specified) search path
-        */
-
-       vector<string> dirs;
+       // now check the explicit (possibly user-specified) search path
 
        switch (type) {
        case DataType::AUDIO:
-               split (config.get_audio_search_path (), dirs, ':');
+               sp += Searchpath(config.get_audio_search_path ());
                break;
        case DataType::MIDI:
-               split (config.get_midi_search_path (), dirs, ':');
+               sp += Searchpath(config.get_midi_search_path ());
                break;
        }
 
-       for (vector<string>::iterator i = dirs.begin(); i != dirs.end(); ++i) {
-               if (find (s.begin(), s.end(), *i) == s.end()) {
-                       s.push_back (*i);
-               }
-       }
-       
-       string search_path;
-
-       for (vector<string>::iterator si = s.begin(); si != s.end(); ++si) {
-               if (!search_path.empty()) {
-                       search_path += ':';
-               }
-               search_path += *si;
-       }
-
-       return search_path;
+       return sp;
 }
 
 void
 Session::ensure_search_path_includes (const string& path, DataType type)
 {
-       string search_path;
-       vector<string> dirs;
+       Searchpath sp;
 
        if (path == ".") {
                return;
@@ -4631,16 +5350,14 @@ Session::ensure_search_path_includes (const string& path, DataType type)
 
        switch (type) {
        case DataType::AUDIO:
-               search_path = config.get_audio_search_path ();
+               sp += Searchpath(config.get_audio_search_path ());
                break;
        case DataType::MIDI:
-               search_path = config.get_midi_search_path ();
+               sp += Searchpath (config.get_midi_search_path ());
                break;
        }
 
-       split (search_path, dirs, ':');
-
-       for (vector<string>::iterator i = dirs.begin(); i != dirs.end(); ++i) {
+       for (vector<std::string>::iterator i = sp.begin(); i != sp.end(); ++i) {
                /* No need to add this new directory if it has the same inode as
                   an existing one; checking inode rather than name prevents duplicated
                   directories when we are using symlinks.
@@ -4652,20 +5369,43 @@ Session::ensure_search_path_includes (const string& path, DataType type)
                }
        }
 
-       if (!search_path.empty()) {
-               search_path += ':';
+       sp += path;
+
+       switch (type) {
+       case DataType::AUDIO:
+               config.set_audio_search_path (sp.to_string());
+               break;
+       case DataType::MIDI:
+               config.set_midi_search_path (sp.to_string());
+               break;
+       }
+}
+
+void
+Session::remove_dir_from_search_path (const string& dir, DataType type)
+{
+       Searchpath sp;
+
+       switch (type) {
+       case DataType::AUDIO:
+               sp = Searchpath(config.get_audio_search_path ());
+               break;
+       case DataType::MIDI:
+               sp = Searchpath (config.get_midi_search_path ());
+               break;
        }
 
-       search_path += path;
+       sp -= dir;
 
        switch (type) {
        case DataType::AUDIO:
-               config.set_audio_search_path (search_path);
+               config.set_audio_search_path (sp.to_string());
                break;
        case DataType::MIDI:
-               config.set_midi_search_path (search_path);
+               config.set_midi_search_path (sp.to_string());
                break;
        }
+
 }
 
 boost::shared_ptr<Speakers>
@@ -4948,6 +5688,8 @@ Session::sync_order_keys ()
 
        DEBUG_TRACE (DEBUG::OrderKeys, "Sync Order Keys.\n");
 
+       reassign_track_numbers();
+
        Route::SyncOrderKeys (); /* EMIT SIGNAL */
 
        DEBUG_TRACE (DEBUG::OrderKeys, "\tsync done\n");