new transport option, "loop-is-mode" which optionally changes the role of the "play...
[ardour.git] / libs / ardour / session_transport.cc
index 5fef402d9fc9597a50f0691d1a1a9e62652da98c..ea9f5d28dd6ee97e2beebb8e8cf65f8a95920c43 100644 (file)
 #include "pbd/enumwriter.h"
 #include "pbd/pthread_utils.h"
 #include "pbd/memento_command.h"
+#include "pbd/stacktrace.h"
 
 #include "midi++/mmc.h"
 #include "midi++/port.h"
-#include "midi++/manager.h"
 
 #include "ardour/audioengine.h"
 #include "ardour/auditioner.h"
@@ -41,6 +41,7 @@
 #include "ardour/click.h"
 #include "ardour/debug.h"
 #include "ardour/location.h"
+#include "ardour/profile.h"
 #include "ardour/session.h"
 #include "ardour/slave.h"
 #include "ardour/operations.h"
@@ -87,7 +88,7 @@ Session::request_sync_source (Slave* new_slave)
 
        seamless = Config->get_seamless_loop ();
 
-       if (dynamic_cast<JACK_Slave*>(new_slave)) {
+       if (dynamic_cast<Engine_Slave*>(new_slave)) {
                /* JACK cannot support seamless looping at present */
                Config->set_seamless_loop (false);
        } else {
@@ -99,14 +100,16 @@ Session::request_sync_source (Slave* new_slave)
        _was_seamless = seamless;
 
        ev->slave = new_slave;
+       DEBUG_TRACE (DEBUG::Slave, "sent request for new slave\n");
        queue_event (ev);
 }
 
 void
-Session::request_transport_speed (double speed)
+Session::request_transport_speed (double speed, bool as_default)
 {
        SessionEvent* ev = new SessionEvent (SessionEvent::SetTransportSpeed, SessionEvent::Add, SessionEvent::Immediate, 0, speed);
-       DEBUG_TRACE (DEBUG::Transport, string_compose ("Request transport speed = %1\n", speed));
+       ev->third_yes_or_no = true;
+       DEBUG_TRACE (DEBUG::Transport, string_compose ("Request transport speed = %1 as default = %2\n", speed, as_default));
        queue_event (ev);
 }
 
@@ -115,13 +118,13 @@ Session::request_transport_speed (double speed)
  *  be used by callers who are varying transport speed but don't ever want to stop it.
  */
 void
-Session::request_transport_speed_nonzero (double speed)
+Session::request_transport_speed_nonzero (double speed, bool as_default)
 {
        if (speed == 0) {
                speed = DBL_EPSILON;
        }
 
-       request_transport_speed (speed);
+       request_transport_speed (speed, as_default);
 }
 
 void
@@ -157,10 +160,11 @@ Session::force_locate (framepos_t target_frame, bool with_roll)
 }
 
 void
-Session::request_play_loop (bool yn, bool leave_rolling)
+Session::request_play_loop (bool yn, bool change_transport_roll)
 {
        SessionEvent* ev;
        Location *location = _locations->auto_loop_location();
+       double target_speed;
 
        if (location == 0 && yn) {
                error << _("Cannot loop - no loop range defined")
@@ -168,14 +172,44 @@ Session::request_play_loop (bool yn, bool leave_rolling)
                return;
        }
 
-       ev = new SessionEvent (SessionEvent::SetLoop, SessionEvent::Add, SessionEvent::Immediate, 0, (leave_rolling ? 1.0 : 0.0), yn);
-       DEBUG_TRACE (DEBUG::Transport, string_compose ("Request set loop = %1, leave rolling ? %2\n", yn, leave_rolling));
+       if (change_transport_roll) {
+               if (transport_rolling()) {
+                       /* start looping at current speed */
+                       target_speed = transport_speed ();
+               } else {
+                       /* currently stopped */
+                       if (yn) {
+                               /* start looping at normal speed */
+                               target_speed = 1.0;
+                       } else {
+                               target_speed = 0.0;
+                       }
+               }
+       } else {
+               /* leave the speed alone */
+               target_speed = transport_speed ();
+       }
+
+       ev = new SessionEvent (SessionEvent::SetLoop, SessionEvent::Add, SessionEvent::Immediate, 0, target_speed, yn);
+       DEBUG_TRACE (DEBUG::Transport, string_compose ("Request set loop = %1, change roll state ? %2\n", yn, change_transport_roll));
        queue_event (ev);
 
-       if (!leave_rolling && !yn && Config->get_seamless_loop() && transport_rolling()) {
-               // request an immediate locate to refresh the tracks
-               // after disabling looping
-               request_locate (_transport_frame-1, false);
+       if (yn) {
+               if (!change_transport_roll) {
+                       if (!transport_rolling()) {
+                               /* we're not changing transport state, but we do want
+                                  to set up position for the new loop. Don't
+                                  do this if we're rolling already.
+                               */
+                               request_locate (location->start(), false);
+                       }
+               }
+       } else {
+               if (!change_transport_roll && Config->get_seamless_loop() && transport_rolling()) {
+                       // request an immediate locate to refresh the tracks
+                       // after disabling looping
+                       request_locate (_transport_frame-1, false);
+               }
        }
 }
 
@@ -202,6 +236,7 @@ Session::realtime_stop (bool abort, bool clear_state)
 
        if (_transport_speed < 0.0f) {
                todo = (PostTransportWork (todo | PostTransportStop | PostTransportReverse));
+               _default_transport_speed = 1.0;
        } else {
                todo = PostTransportWork (todo | PostTransportStop);
        }
@@ -298,8 +333,8 @@ Session::butler_transport_work ()
                        if (tr) {
                                tr->adjust_playback_buffering ();
                                /* and refill those buffers ... */
-                               tr->non_realtime_locate (_transport_frame);
                        }
+                       (*i)->non_realtime_locate (_transport_frame);
                }
 
        }
@@ -343,10 +378,8 @@ Session::butler_transport_work ()
                if (!(ptw & PostTransportLocate)) {
 
                        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-                               boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
-                               if (tr && !tr->hidden()) {
-                                       tr->non_realtime_locate (_transport_frame);
-                               }
+                               (*i)->non_realtime_locate (_transport_frame);
+
                                if (on_entry != g_atomic_int_get (&_butler->should_do_transport_work)) {
                                        /* new request, stop seeking, and start again */
                                        g_atomic_int_dec_and_test (&_butler->should_do_transport_work);
@@ -383,6 +416,7 @@ Session::butler_transport_work ()
        g_atomic_int_dec_and_test (&_butler->should_do_transport_work);
 
        DEBUG_TRACE (DEBUG::Transport, X_("Butler transport work all done\n"));
+       DEBUG_TRACE (DEBUG::Transport, X_(string_compose ("Frame %1\n", _transport_frame)));
 }
 
 void
@@ -419,10 +453,7 @@ Session::non_realtime_locate ()
 {
        boost::shared_ptr<RouteList> rl = routes.reader();
        for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
-               boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
-               if (tr) {
-                       tr->non_realtime_locate (_transport_frame);
-               }
+               (*i)->non_realtime_locate (_transport_frame);
        }
 
        /* XXX: it would be nice to generate the new clicks here (in the non-RT thread)
@@ -493,7 +524,7 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
        boost::shared_ptr<RouteList> r = routes.reader ();
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               if (!(*i)->is_hidden()) {
+               if (!(*i)->is_auditioner()) {
                        (*i)->set_pending_declick (0);
                }
        }
@@ -516,13 +547,13 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
        if (auto_return_enabled ||
            (ptw & PostTransportLocate) ||
            (_requested_return_frame >= 0) ||
-           synced_to_jack()) {
+           synced_to_engine()) {
 
                if (pending_locate_flush) {
                        flush_all_inserts ();
                }
 
-               if ((auto_return_enabled || synced_to_jack() || _requested_return_frame >= 0) &&
+               if ((auto_return_enabled || synced_to_engine() || _requested_return_frame >= 0) &&
                    !(ptw & PostTransportLocate)) {
 
                        /* no explicit locate queued */
@@ -533,8 +564,6 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 
                                /* explicit return request pre-queued in event list. overrides everything else */
 
-                               cerr << "explicit auto-return to " << _requested_return_frame << endl;
-
                                _transport_frame = _requested_return_frame;
                                do_locate = true;
 
@@ -545,7 +574,7 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 
                                                /* don't try to handle loop play when synced to JACK */
 
-                                               if (!synced_to_jack()) {
+                                               if (!synced_to_engine()) {
 
                                                        Location *location = _locations->auto_loop_location();
 
@@ -591,8 +620,10 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
        */
 
        if (ptw & PostTransportClearSubstate) {
-               _play_range = false;
-               unset_play_loop ();
+               unset_play_range ();
+               if (!Config->get_loop_is_mode()) {
+                       unset_play_loop ();
+               }
        }
 
        /* this for() block can be put inside the previous if() and has the effect of ... ??? what */
@@ -600,10 +631,7 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
        DEBUG_TRACE (DEBUG::Transport, X_("Butler PTW: locate\n"));
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
                DEBUG_TRACE (DEBUG::Transport, string_compose ("Butler PTW: locate on %1\n", (*i)->name()));
-               boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
-               if (tr && !tr->hidden()) {
-                       tr->non_realtime_locate (_transport_frame);
-               }
+               (*i)->non_realtime_locate (_transport_frame);
 
                if (on_entry != g_atomic_int_get (&_butler->should_do_transport_work)) {
                        finished = false;
@@ -614,19 +642,41 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 
        have_looped = false;
 
-       if (!_engine.freewheeling()) {
-               send_full_time_code (_transport_frame);
+       /* don't bother with this stuff if we're disconnected from the engine,
+          because there will be no process callbacks to deliver stuff from
+       */
+
+       if (_engine.connected() && !_engine.freewheeling()) {
+               // need to queue this in the next RT cycle
+               _send_timecode_update = true;
                
                if (!dynamic_cast<MTC_Slave*>(_slave)) {
-                       MIDI::Manager::instance()->mmc()->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdStop));
+                       _mmc->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdStop));
+
+                       /* This (::non_realtime_stop()) gets called by main
+                          process thread, which will lead to confusion
+                          when calling AsyncMIDIPort::write().
+                          
+                          Something must be done. XXX
+                       */
                        send_mmc_locate (_transport_frame);
                }
        }
 
        if ((ptw & PostTransportLocate) && get_record_enabled()) {
-               /* capture start has been changed, so save pending state */
-               save_state ("", true);
-               saved = true;
+               /* This is scheduled by realtime_stop(), which is also done
+                * when a slave requests /locate/ for an initial sync.
+                * We can't hold up the slave for long with a save() here,
+                * without breaking its initial sync cycle.
+                *
+                * save state only if there's no slave or if it's not yet locked.
+                */
+               if (!_slave || !_slave->locked()) {
+                       DEBUG_TRACE (DEBUG::Transport, X_("Butler PTW: pending save\n"));
+                       /* capture start has been changed, so save pending state */
+                       save_state ("", true);
+                       saved = true;
+               }
        }
 
        /* always try to get rid of this */
@@ -640,19 +690,26 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
        }
 
        if (ptw & PostTransportStop) {
-               _play_range = false;
-               play_loop = false;
+               unset_play_range ();
+               if (!Config->get_loop_is_mode()) {
+                       unset_play_loop ();
+               }
        }
 
        PositionChanged (_transport_frame); /* EMIT SIGNAL */
+       DEBUG_TRACE (DEBUG::Transport, string_compose ("send TSC with speed = %1\n", _transport_speed));
        TransportStateChange (); /* EMIT SIGNAL */
 
        /* and start it up again if relevant */
 
        if ((ptw & PostTransportLocate) && !config.get_external_sync() && pending_locate_roll) {
                request_transport_speed (1.0);
-               pending_locate_roll = false;
        }
+
+       /* Even if we didn't do a pending locate roll this time, we don't want it hanging
+          around for next time.
+       */
+       pending_locate_roll = false;
 }
 
 void
@@ -662,7 +719,7 @@ Session::check_declick_out ()
 
        /* this is called after a process() iteration. if PendingDeclickOut was set,
           it means that we were waiting to declick the output (which has just been
-          done) before doing something else. this is where we do that "something else".
+          done) before maybe doing something else. this is where we do that "something else".
 
           note: called from the audio thread.
        */
@@ -676,6 +733,10 @@ Session::check_declick_out ()
                        stop_transport (pending_abort);
                        transport_sub_state &= ~(PendingDeclickOut|PendingLocate);
                }
+
+       } else if (transport_sub_state & PendingLoopDeclickOut) {
+               /* Nothing else to do here; we've declicked, and the loop event will be along shortly */
+               transport_sub_state &= ~PendingLoopDeclickOut;
        }
 }
 
@@ -684,6 +745,7 @@ Session::unset_play_loop ()
 {
        play_loop = false;
        clear_events (SessionEvent::AutoLoop);
+       clear_events (SessionEvent::AutoLoopDeclick);
 
        // set all tracks to NOT use internal looping
        boost::shared_ptr<RouteList> rl = routes.reader ();
@@ -696,7 +758,7 @@ Session::unset_play_loop ()
 }
 
 void
-Session::set_play_loop (bool yn)
+Session::set_play_loop (bool yn, double speed)
 {
        /* Called from event-handling context */
 
@@ -707,7 +769,7 @@ Session::set_play_loop (bool yn)
                return;
        }
 
-       if (yn && Config->get_seamless_loop() && synced_to_jack()) {
+       if (yn && Config->get_seamless_loop() && synced_to_engine()) {
                warning << string_compose (
                        _("Seamless looping cannot be supported while %1 is using JACK transport.\n"
                          "Recommend changing the configured options"), PROGRAM_NAME)
@@ -744,16 +806,35 @@ Session::set_play_loop (bool yn)
                                }
                        }
 
-                       /* put the loop event into the event list */
+                       /* Put the delick and loop events in into the event list.  The declick event will
+                          cause a de-clicking fade-out just before the end of the loop, and it will also result
+                          in a fade-in when the loop restarts.  The AutoLoop event will peform the actual loop.
+                       */
+
+                       framepos_t dcp;
+                       framecnt_t dcl;
+                       auto_loop_declick_range (loc, dcp, dcl);
+                       merge_event (new SessionEvent (SessionEvent::AutoLoopDeclick, SessionEvent::Replace, dcp, dcl, 0.0f));
+                       merge_event (new SessionEvent (SessionEvent::AutoLoop, SessionEvent::Replace, loc->end(), loc->start(), 0.0f));
 
-                       SessionEvent* event = new SessionEvent (SessionEvent::AutoLoop, SessionEvent::Replace, loc->end(), loc->start(), 0.0f);
-                       merge_event (event);
+                       /* if requested to roll, locate to start of loop and
+                        * roll but ONLY if we're not already rolling.
 
-                       /* locate to start of loop and roll. If doing seamless loop, force a
-                          locate+buffer refill even if we are positioned there already.
+                          args: positition, roll=true, flush=true, with_loop=false, force buffer refill if seamless looping
                        */
 
-                       start_locate (loc->start(), true, true, false, Config->get_seamless_loop());
+                       if (Config->get_loop_is_mode()) {
+                               /* loop IS a transport mode: if already
+                                  rolling, do not locate to loop start.
+                               */
+                               if (!transport_rolling() && (speed != 0.0)) {
+                                       start_locate (loc->start(), true, true, false, Config->get_seamless_loop());
+                               }
+                       } else {
+                               if (speed != 0.0) {
+                                       start_locate (loc->start(), true, true, false, Config->get_seamless_loop());
+                               }
+                       }
                }
 
        } else {
@@ -761,6 +842,7 @@ Session::set_play_loop (bool yn)
                unset_play_loop ();
        }
 
+       DEBUG_TRACE (DEBUG::Transport, string_compose ("send TSC2 with speed = %1\n", _transport_speed));
        TransportStateChange ();
 }
 void
@@ -776,7 +858,7 @@ Session::flush_all_inserts ()
 void
 Session::start_locate (framepos_t target_frame, bool with_roll, bool with_flush, bool with_loop, bool force)
 {
-       if (synced_to_jack()) {
+       if (synced_to_engine()) {
 
                double sp;
                framepos_t pos;
@@ -785,6 +867,14 @@ Session::start_locate (framepos_t target_frame, bool with_roll, bool with_flush,
 
                if (target_frame != pos) {
 
+                       if (config.get_jack_time_master()) {
+                               /* actually locate now, since otherwise jack_timebase_callback
+                                  will use the incorrect _transport_frame and report an old
+                                  and incorrect time to Jack transport
+                               */
+                               locate (target_frame, with_roll, with_flush, with_loop, force);
+                       }
+
                        /* tell JACK to change transport position, and we will
                           follow along later in ::follow_slave()
                        */
@@ -826,13 +916,21 @@ Session::micro_locate (framecnt_t distance)
 
 /** @param with_mmc true to send a MMC locate command when the locate is done */
 void
-Session::locate (framepos_t target_frame, bool with_roll, bool with_flush, bool with_loop, bool force, bool with_mmc)
+Session::locate (framepos_t target_frame, bool with_roll, bool with_flush, bool for_seamless_loop, bool force, bool with_mmc)
 {
-       if (actively_recording() && !with_loop) {
+       /* Locates for seamless looping are fairly different from other
+        * locates. They assume that the diskstream buffers for each track
+        * already have the correct data in them, and thus there is no need to
+        * actually tell the tracks to locate. What does need to be done,
+        * though, is all the housekeeping that is associated with non-linear
+        * changes in the value of _transport_frame. 
+        */
+
+       if (actively_recording() && !for_seamless_loop) {
                return;
        }
 
-       if (!force && _transport_frame == target_frame && !loop_changing && !with_loop) {
+       if (!force && _transport_frame == target_frame && !loop_changing && !for_seamless_loop) {
                if (with_roll) {
                        set_transport_speed (1.0, false);
                }
@@ -841,8 +939,11 @@ Session::locate (framepos_t target_frame, bool with_roll, bool with_flush, bool
                return;
        }
 
-       if (_transport_speed) {
-               /* schedule a declick. we'll be called again when its done */
+       if (_transport_speed && !for_seamless_loop) {
+               /* Schedule a declick.  We'll be called again when its done.
+                  We only do it this way for ordinary locates, not those
+                  due to **seamless** loops.
+               */
 
                if (!(transport_sub_state & PendingDeclickOut)) {
                        transport_sub_state |= (PendingDeclickOut|PendingLocate);
@@ -856,6 +957,7 @@ Session::locate (framepos_t target_frame, bool with_roll, bool with_flush, bool
        // Update Timecode time
        // [DR] FIXME: find out exactly where this should go below
        _transport_frame = target_frame;
+       _last_roll_or_reversal_location = target_frame;
        timecode_time(_transport_frame, transmitting_timecode_time);
        outbound_mtc_timecode_frame = _transport_frame;
        next_quarter_frame_to_send = 0;
@@ -869,18 +971,21 @@ Session::locate (framepos_t target_frame, bool with_roll, bool with_flush, bool
          *
         */
 
-       if (transport_rolling() && (!auto_play_legal || !config.get_auto_play()) && !with_roll && !(synced_to_jack() && play_loop)) {
+       bool transport_was_stopped = !transport_rolling();
+
+       if (transport_was_stopped && (!auto_play_legal || !config.get_auto_play()) && !with_roll && !(synced_to_engine() && play_loop)) {
                realtime_stop (false, true); // XXX paul - check if the 2nd arg is really correct
+               transport_was_stopped = true;
        } else {
                /* otherwise tell the world that we located */
                realtime_locate ();
        }
 
-       if (force || !with_loop || loop_changing) {
+       if (force || !for_seamless_loop || loop_changing) {
 
                PostTransportWork todo = PostTransportLocate;
 
-               if (with_roll) {
+               if (with_roll && transport_was_stopped) {
                        todo = PostTransportWork (todo | PostTransportRoll);
                }
 
@@ -891,7 +996,7 @@ Session::locate (framepos_t target_frame, bool with_roll, bool with_flush, bool
 
                /* this is functionally what clear_clicks() does but with a tentative lock */
 
-               Glib::RWLock::WriterLock clickm (click_lock, Glib::TRY_LOCK);
+               Glib::Threads::RWLock::WriterLock clickm (click_lock, Glib::Threads::TRY_LOCK);
 
                if (clickm.locked()) {
 
@@ -917,27 +1022,41 @@ Session::locate (framepos_t target_frame, bool with_roll, bool with_flush, bool
 
        /* cancel looped playback if transport pos outside of loop range */
        if (play_loop) {
+
                Location* al = _locations->auto_loop_location();
 
-               if (al && (_transport_frame < al->start() || _transport_frame > al->end())) {
-                       // cancel looping directly, this is called from event handling context
-                       set_play_loop (false);
-               }
-               else if (al && _transport_frame == al->start()) {
-                       if (with_loop) {
-                               // this is only necessary for seamless looping
+               if (al) {
+                       if (_transport_frame < al->start() || _transport_frame > al->end()) {
 
-                               boost::shared_ptr<RouteList> rl = routes.reader();
-                               for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
-                                       boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
-                                       if (tr && tr->record_enabled ()) {
-                                               // tell it we've looped, so it can deal with the record state
-                                               tr->transport_looped(_transport_frame);
+                               // located outside the loop: cancel looping directly, this is called from event handling context
+
+                               if (!Config->get_loop_is_mode()) {
+                                       set_play_loop (false, _transport_speed);
+                               }
+                               
+                       } else if (_transport_frame == al->start()) {
+
+                               // located to start of loop - this is looping, basically
+
+                               if (for_seamless_loop) {
+
+                                       // this is only necessary for seamless looping
+                                       
+                                       boost::shared_ptr<RouteList> rl = routes.reader();
+
+                                       for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
+                                               boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
+
+                                               if (tr && tr->record_enabled ()) {
+                                                       // tell it we've looped, so it can deal with the record state
+                                                       tr->transport_looped (_transport_frame);
+                                               }
                                        }
                                }
+
+                               have_looped = true;
+                               TransportLooped(); // EMIT SIGNAL
                        }
-                       have_looped = true;
-                       TransportLooped(); // EMIT SIGNAL
                }
        }
 
@@ -949,6 +1068,7 @@ Session::locate (framepos_t target_frame, bool with_roll, bool with_flush, bool
                send_mmc_locate (_transport_frame);
        }
 
+       _last_roll_location = _last_roll_or_reversal_location =  _transport_frame;
        Located (); /* EMIT SIGNAL */
 }
 
@@ -957,17 +1077,22 @@ Session::locate (framepos_t target_frame, bool with_roll, bool with_flush, bool
  *  @param speed New speed
  */
 void
-Session::set_transport_speed (double speed, bool abort, bool clear_state)
+Session::set_transport_speed (double speed, bool abort, bool clear_state, bool as_default)
 {
-       DEBUG_TRACE (DEBUG::Transport, string_compose ("@ %5 Set transport speed to %1, abort = %2 clear_state = %3, current = %4\n", 
-                                                      speed, abort, clear_state, _transport_speed, _transport_frame));
+       DEBUG_TRACE (DEBUG::Transport, string_compose ("@ %5 Set transport speed to %1, abort = %2 clear_state = %3, current = %4 as_default %6\n", 
+                                                      speed, abort, clear_state, _transport_speed, _transport_frame, as_default));
 
        if (_transport_speed == speed) {
+               if (as_default && speed == 0.0) { // => reset default transport speed. hacky or what?
+                       _default_transport_speed = 1.0;
+               }
                return;
        }
 
        if (actively_recording() && speed != 1.0 && speed != 0.0) {
                /* no varispeed during recording */
+               DEBUG_TRACE (DEBUG::Transport, string_compose ("No varispeed during recording cur_speed %1, frame %2\n", 
+                                                      _transport_speed, _transport_frame));
                return;
        }
 
@@ -991,7 +1116,7 @@ Session::set_transport_speed (double speed, bool abort, bool clear_state)
                        set_track_monitor_input_status (true);
                }
 
-               if (synced_to_jack ()) {
+               if (synced_to_engine ()) {
                        if (clear_state) {
                                /* do this here because our response to the slave won't
                                   take care of it.
@@ -1004,17 +1129,32 @@ Session::set_transport_speed (double speed, bool abort, bool clear_state)
                        stop_transport (abort);
                }
 
-               unset_play_loop ();
+               if (!Config->get_loop_is_mode()) {
+                       unset_play_loop ();
+               }
 
        } else if (transport_stopped() && speed == 1.0) {
 
                /* we are stopped and we want to start rolling at speed 1 */
 
+               if (Config->get_loop_is_mode() && play_loop) {
+
+                       Location *location = _locations->auto_loop_location();
+                       
+                       if (location != 0) {
+                               if (_transport_frame != location->start()) {
+                                       /* jump to start and then roll from there */
+                                       request_locate (location->start(), true);
+                                       return;
+                               }
+                       }
+               }
+
                if (Config->get_monitoring_model() == HardwareMonitoring && config.get_auto_input()) {
                        set_track_monitor_input_status (false);
                }
 
-               if (synced_to_jack()) {
+               if (synced_to_engine()) {
                        _engine.transport_start ();
                } else {
                        start_transport ();
@@ -1024,7 +1164,7 @@ Session::set_transport_speed (double speed, bool abort, bool clear_state)
 
                /* not zero, not 1.0 ... varispeed */
 
-               if ((synced_to_jack()) && speed != 0.0 && speed != 1.0) {
+               if ((synced_to_engine()) && speed != 0.0 && speed != 1.0) {
                        warning << string_compose (
                                _("Global varispeed cannot be supported while %1 is connected to JACK transport control"),
                                PROGRAM_NAME)
@@ -1060,6 +1200,10 @@ Session::set_transport_speed (double speed, bool abort, bool clear_state)
                _last_transport_speed = _transport_speed;
                _transport_speed = speed;
 
+               if (as_default) {
+                       _default_transport_speed = speed;
+               }
+
                boost::shared_ptr<RouteList> rl = routes.reader();
                for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
                        boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
@@ -1073,6 +1217,7 @@ Session::set_transport_speed (double speed, bool abort, bool clear_state)
                        _butler->schedule_transport_work ();
                }
 
+               DEBUG_TRACE (DEBUG::Transport, string_compose ("send TSC3 with speed = %1\n", _transport_speed));
                TransportStateChange (); /* EMIT SIGNAL */
        }
 }
@@ -1175,8 +1320,8 @@ Session::start_transport ()
 
        transport_sub_state |= PendingDeclickIn;
 
-       _transport_speed = 1.0;
-       _target_transport_speed = 1.0;
+       _transport_speed = _default_transport_speed;
+       _target_transport_speed = _transport_speed;
 
        boost::shared_ptr<RouteList> rl = routes.reader();
        for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
@@ -1184,17 +1329,17 @@ Session::start_transport ()
                if (tr) {
                        tr->realtime_set_speed (tr->speed(), true);
                }
-               (*i)->automation_snapshot (_transport_frame, true);
        }
 
        if (!_engine.freewheeling()) {
                Timecode::Time time;
                timecode_time_subframes (_transport_frame, time);
                if (!dynamic_cast<MTC_Slave*>(_slave)) {
-                       MIDI::Manager::instance()->mmc()->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdDeferredPlay));
+                       _mmc->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdDeferredPlay));
                }
        }
 
+       DEBUG_TRACE (DEBUG::Transport, string_compose ("send TSC4 with speed = %1\n", _transport_speed));
        TransportStateChange (); /* EMIT SIGNAL */
 }
 
@@ -1223,7 +1368,6 @@ Session::post_transport ()
 
                if (((!config.get_external_sync() && (auto_play_legal && config.get_auto_play())) && !_exporting) || (ptw & PostTransportRoll)) {
                        start_transport ();
-
                } else {
                        transport_sub_state = 0;
                }
@@ -1268,7 +1412,10 @@ Session::use_sync_source (Slave* new_slave)
        delete _slave;
        _slave = new_slave;
 
-       send_full_time_code (_transport_frame);
+       DEBUG_TRACE (DEBUG::Slave, string_compose ("set new slave to %1\n", _slave));
+       
+       // need to queue this for next process() cycle
+       _send_timecode_update = true;
 
        boost::shared_ptr<RouteList> rl = routes.reader();
        for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
@@ -1309,12 +1456,27 @@ Session::switch_to_sync_source (SyncSource src)
                }
 
                try {
-                       new_slave = new MTC_Slave (*this, *MIDI::Manager::instance()->mtc_input_port());
+                       new_slave = new MTC_Slave (*this, *_midi_ports->mtc_input_port());
+               }
+
+               catch (failed_constructor& err) {
+                       return;
+               }
+               break;
+
+       case LTC:
+               if (_slave && dynamic_cast<LTC_Slave*>(_slave)) {
+                       return;
+               }
+
+               try {
+                       new_slave = new LTC_Slave (*this);
                }
 
                catch (failed_constructor& err) {
                        return;
                }
+
                break;
 
        case MIDIClock:
@@ -1323,7 +1485,7 @@ Session::switch_to_sync_source (SyncSource src)
                }
 
                try {
-                       new_slave = new MIDIClock_Slave (*this, *MIDI::Manager::instance()->midi_clock_input_port(), 24);
+                       new_slave = new MIDIClock_Slave (*this, *_midi_ports->midi_clock_input_port(), 24);
                }
 
                catch (failed_constructor& err) {
@@ -1331,8 +1493,8 @@ Session::switch_to_sync_source (SyncSource src)
                }
                break;
 
-       case JACK:
-               if (_slave && dynamic_cast<JACK_Slave*>(_slave)) {
+       case Engine:
+               if (_slave && dynamic_cast<Engine_Slave*>(_slave)) {
                        return;
                }
 
@@ -1340,7 +1502,7 @@ Session::switch_to_sync_source (SyncSource src)
                        return;
                }
 
-               new_slave = new JACK_Slave (_engine.jack());
+               new_slave = new Engine_Slave (*AudioEngine::instance());
                break;
 
        default:
@@ -1444,6 +1606,7 @@ Session::set_play_range (list<AudioRange>& range, bool leave_rolling)
        ev = new SessionEvent (SessionEvent::LocateRoll, SessionEvent::Add, SessionEvent::Immediate, range.front().start, 0.0f, false);
        merge_event (ev);
 
+       DEBUG_TRACE (DEBUG::Transport, string_compose ("send TSC5 with speed = %1\n", _transport_speed));
        TransportStateChange ();
 }
 
@@ -1476,14 +1639,17 @@ Session::engine_halted ()
           the picture.
        */
 
-       g_atomic_int_set (&_butler->should_do_transport_work, 0);
-       set_post_transport_work (PostTransportWork (0));
-       _butler->stop ();
+       if (_butler) {
+               g_atomic_int_set (&_butler->should_do_transport_work, 0);
+               set_post_transport_work (PostTransportWork (0));
+               _butler->stop ();
+       }
 
        realtime_stop (false, true);
        non_realtime_stop (false, 0, ignored);
        transport_sub_state = 0;
 
+       DEBUG_TRACE (DEBUG::Transport, string_compose ("send TSC6 with speed = %1\n", _transport_speed));
        TransportStateChange (); /* EMIT SIGNAL */
 }
 
@@ -1526,23 +1692,13 @@ Session::allow_auto_play (bool yn)
        auto_play_legal = yn;
 }
 
-void
-Session::reset_jack_connection (jack_client_t* jack)
-{
-       JACK_Slave* js;
-
-       if (_slave && ((js = dynamic_cast<JACK_Slave*> (_slave)) != 0)) {
-               js->reset_client (jack);
-       }
-}
-
 bool
 Session::maybe_stop (framepos_t limit)
 {
        if ((_transport_speed > 0.0f && _transport_frame >= limit) || (_transport_speed < 0.0f && _transport_frame == 0)) {
-               if (synced_to_jack () && config.get_jack_time_master ()) {
+               if (synced_to_engine () && config.get_jack_time_master ()) {
                        _engine.transport_stop ();
-               } else if (!synced_to_jack ()) {
+               } else if (!synced_to_engine ()) {
                        stop_transport ();
                }
                return true;
@@ -1556,7 +1712,7 @@ Session::send_mmc_locate (framepos_t t)
        if (!_engine.freewheeling()) {
                Timecode::Time time;
                timecode_time_subframes (t, time);
-               MIDI::Manager::instance()->mmc()->send (MIDI::MachineControlCommand (time));
+               _mmc->send (MIDI::MachineControlCommand (time));
        }
 }