NO-OP; whitespace
[ardour.git] / libs / ardour / session_process.cc
index 662da4db9114be5c5edc55f9cefc4cea051961fd..766ce395e51fc16edc60afbd46ba93526bcaf6e3 100644 (file)
 #include "pbd/error.h"
 #include "pbd/enumwriter.h"
 
-#include <glibmm/thread.h>
+#include <glibmm/threads.h>
 
-#include "ardour/ardour.h"
 #include "ardour/audioengine.h"
 #include "ardour/auditioner.h"
 #include "ardour/butler.h"
+#include "ardour/cycle_timer.h"
 #include "ardour/debug.h"
+#include "ardour/graph.h"
+#include "ardour/port.h"
 #include "ardour/process_thread.h"
+#include "ardour/scene_changer.h"
 #include "ardour/session.h"
 #include "ardour/slave.h"
-#include "ardour/timestamps.h"
-#include "ardour/graph.h"
-#include "ardour/audio_port.h"
+#include "ardour/ticker.h"
+#include "ardour/types.h"
 
-#include "midi++/manager.h"
 #include "midi++/mmc.h"
 
-#include "i18n.h"
+#include "pbd/i18n.h"
 
 using namespace ARDOUR;
 using namespace PBD;
@@ -51,10 +52,11 @@ using namespace std;
 /** Called by the audio engine when there is work to be done with JACK.
  * @param nframes Number of frames to process.
  */
+
 void
 Session::process (pframes_t nframes)
 {
-       MIDI::Manager::instance()->cycle_start(nframes);
+       framepos_t transport_at_start = _transport_frame;
 
        _silent = false;
 
@@ -73,19 +75,49 @@ Session::process (pframes_t nframes)
 
        (this->*process_function) (nframes);
 
+       /* realtime-safe meter-position and processor-order changes
+        *
+        * ideally this would be done in
+        * Route::process_output_buffers() but various functions
+        * callig it hold a _processor_lock reader-lock
+        */
+       boost::shared_ptr<RouteList> r = routes.reader ();
+       for (RouteList::const_iterator i = r->begin(); i != r->end(); ++i) {
+               if ((*i)->apply_processor_changes_rt()) {
+                       _rt_emit_pending = true;
+               }
+       }
+       if (_rt_emit_pending) {
+               if (!_rt_thread_active) {
+                       emit_route_signals ();
+               }
+               if (pthread_mutex_trylock (&_rt_emit_mutex) == 0) {
+                       pthread_cond_signal (&_rt_emit_cond);
+                       pthread_mutex_unlock (&_rt_emit_mutex);
+                       _rt_emit_pending = false;
+               }
+       }
+
        _engine.main_thread()->drop_buffers ();
 
-       // the ticker is for sending time information like MidiClock
-       framepos_t transport_frames = transport_frame();
-       Timecode::BBT_Time transport_bbt;
-       bbt_time(transport_frames, transport_bbt);
-       Timecode::Time transport_timecode;
-       timecode_time(transport_frames, transport_timecode);
-       tick (transport_frames, transport_bbt, transport_timecode); /* EMIT SIGNAL */
+       /* deliver MIDI clock. Note that we need to use the transport frame
+        * position at the start of process(), not the value at the end of
+        * it. We may already have ticked() because of a transport state
+        * change, for example.
+        */
 
-       SendFeedback (); /* EMIT SIGNAL */
+       try {
+               if (!_silent && !_engine.freewheeling() && Config->get_send_midi_clock() && (transport_speed() == 1.0f || transport_speed() == 0.0f) && midi_clock->has_midi_port()) {
+                       midi_clock->tick (transport_at_start, nframes);
+               }
 
-       MIDI::Manager::instance()->cycle_end();
+               _scene_changer->run (transport_at_start, transport_at_start + nframes);
+
+       } catch (...) {
+               /* don't bother with a message */
+       }
+
+       SendFeedback (); /* EMIT SIGNAL */
 }
 
 int
@@ -97,110 +129,126 @@ Session::fail_roll (pframes_t nframes)
 int
 Session::no_roll (pframes_t nframes)
 {
+       PT_TIMING_CHECK (4);
+
        framepos_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
        int ret = 0;
-       bool declick = get_transport_declick_required();
+       int declick = (config.get_use_transport_fades() ? get_transport_declick_required() : false);
        boost::shared_ptr<RouteList> r = routes.reader ();
 
        if (_click_io) {
                _click_io->silence (nframes);
        }
 
-       DEBUG_TRACE(DEBUG::Graph,"calling graph/no-roll\n");
-       route_graph->routes_no_roll( nframes, _transport_frame, end_frame, non_realtime_work_pending(), actively_recording(), declick);
-        /*
-       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+       ltc_tx_send_time_code_for_cycle (_transport_frame, end_frame, _target_transport_speed, _transport_speed, nframes);
 
-               if ((*i)->is_hidden()) {
-                       continue;
-               }
+       if (_process_graph) {
+               DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/no-roll\n");
+               _process_graph->routes_no_roll( nframes, _transport_frame, end_frame, non_realtime_work_pending(), declick);
+       } else {
+               PT_TIMING_CHECK (10);
+               for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 
-               (*i)->set_pending_declick (declick);
+                       if ((*i)->is_auditioner()) {
+                               continue;
+                       }
 
-               if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending(),
-                                  actively_recording(), declick)) {
-                       error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
-                       ret = -1;
-                       break;
+                       (*i)->set_pending_declick (declick);
+
+                       if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending())) {
+                               error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
+                               ret = -1;
+                               break;
+                       }
                }
+               PT_TIMING_CHECK (11);
        }
-        */
 
+       PT_TIMING_CHECK (5);
        return ret;
 }
 
+/** @param need_butler to be set to true by this method if it needs the butler,
+ *  otherwise it must be left alone.
+ */
 int
 Session::process_routes (pframes_t nframes, bool& need_butler)
 {
-       bool record_active;
-       int  declick = get_transport_declick_required();
-       bool rec_monitors = get_rec_monitors_input();
+       int declick = (config.get_use_transport_fades() ? get_transport_declick_required() : false);
        boost::shared_ptr<RouteList> r = routes.reader ();
 
-       if (transport_sub_state & StopPendingCapture) {
-               /* force a declick out */
-               declick = -1;
-       }
-
-       record_active = actively_recording(); // || (get_record_enabled() && get_punch_in());
-
        const framepos_t start_frame = _transport_frame;
        const framepos_t end_frame = _transport_frame + floor (nframes * _transport_speed);
 
-       DEBUG_TRACE(DEBUG::Graph,"calling graph/process-routes\n");
-       route_graph->process_routes( nframes, start_frame, end_frame, declick, record_active, rec_monitors, need_butler);
-/*
-       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+       if (_process_graph) {
+               DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/process-routes\n");
+               if (_process_graph->process_routes (nframes, start_frame, end_frame, declick, need_butler) < 0) {
+                       stop_transport ();
+                       return -1;
+               }
+       } else {
 
-               int ret;
+               for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 
-               if ((*i)->is_hidden()) {
-                       continue;
-               }
+                       int ret;
 
-               (*i)->set_pending_declick (declick);
+                       if ((*i)->is_auditioner()) {
+                               continue;
+                       }
 
-               if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, record_active, rec_monitors, need_butler)) < 0) {
-                       stop_transport ();
-                       return -1;
+                       (*i)->set_pending_declick (declick);
+
+                       bool b = false;
+
+                       if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, b)) < 0) {
+                               stop_transport ();
+                               return -1;
+                       }
+
+                       if (b) {
+                               need_butler = true;
+                       }
                }
        }
-*/
+
        return 0;
 }
 
+/** @param need_butler to be set to true by this method if it needs the butler,
+ *  otherwise it must be left alone.
+ */
 int
 Session::silent_process_routes (pframes_t nframes, bool& need_butler)
 {
-       bool record_active = actively_recording();
-       int  declick = get_transport_declick_required();
-       bool rec_monitors = get_rec_monitors_input();
        boost::shared_ptr<RouteList> r = routes.reader ();
 
-       if (transport_sub_state & StopPendingCapture) {
-               /* force a declick out */
-               declick = -1;
-       }
-
        const framepos_t start_frame = _transport_frame;
        const framepos_t end_frame = _transport_frame + lrintf(nframes * _transport_speed);
 
-       route_graph->silent_process_routes( nframes, start_frame, end_frame, record_active, rec_monitors, need_butler);
-/*
-       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+       if (_process_graph) {
+               _process_graph->silent_process_routes (nframes, start_frame, end_frame, need_butler);
+       } else {
+               for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 
-               int ret;
+                       int ret;
 
-               if ((*i)->is_hidden()) {
-                       continue;
-               }
+                       if ((*i)->is_auditioner()) {
+                               continue;
+                       }
 
-               if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, record_active, rec_monitors, need_butler)) < 0) {
-                       stop_transport ();
-                       return -1;
+                       bool b = false;
+
+                       if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, b)) < 0) {
+                               stop_transport ();
+                               return -1;
+                       }
+
+                       if (b) {
+                               need_butler = true;
+                       }
                }
        }
-*/
+
        return 0;
 }
 
@@ -235,11 +283,12 @@ Session::get_track_statistics ()
 void
 Session::process_with_events (pframes_t nframes)
 {
+       PT_TIMING_CHECK (3);
+
        SessionEvent*  ev;
        pframes_t      this_nframes;
        framepos_t     end_frame;
        bool           session_needs_butler = false;
-       framepos_t     stop_limit;
        framecnt_t     frames_moved;
 
        /* make sure the auditioner is silent */
@@ -265,12 +314,83 @@ Session::process_with_events (pframes_t nframes)
                process_event (ev);
        }
 
-       /* Events caused a transport change, send an MTC Full Frame (Timecode) message.
-        * This is sent whether rolling or not, to give slaves an idea of ardour time
-        * on locates (and allow slow slaves to position and prepare for rolling)
+       /* count in */
+       if (_transport_speed != 1.0 && _count_in_samples > 0) {
+               _count_in_samples = 0;
+       }
+
+       if (_count_in_samples > 0) {
+               framecnt_t ns = std::min ((framecnt_t)nframes, _count_in_samples);
+
+               no_roll (ns);
+               run_click (_transport_frame - _count_in_samples, ns);
+
+               _count_in_samples -= ns;
+               nframes -= ns;
+
+               /* process events.. */
+               if (!events.empty() && next_event != events.end()) {
+                       SessionEvent* this_event = *next_event;
+                       Events::iterator the_next_one = next_event;
+                       ++the_next_one;
+
+                       while (this_event && this_event->action_frame == _transport_frame) {
+                               process_event (this_event);
+                               if (the_next_one == events.end()) {
+                                       this_event = 0;
+                               } else {
+                                       this_event = *the_next_one;
+                                       ++the_next_one;
+                               }
+                       }
+                       set_next_event ();
+               }
+
+               check_declick_out ();
+
+               if (nframes == 0) {
+                       return;
+               } else {
+                       _engine.split_cycle (ns);
+               }
+       }
+
+       /* Decide on what to do with quarter-frame MTC during this cycle */
+
+       bool const was_sending_qf_mtc = _send_qf_mtc;
+       double const tolerance = Config->get_mtc_qf_speed_tolerance() / 100.0;
+
+       if (_transport_speed != 0) {
+               _send_qf_mtc = (
+                       Config->get_send_mtc () &&
+                       _transport_speed >= (1 - tolerance) &&
+                       _transport_speed <= (1 + tolerance)
+                       );
+
+               if (_send_qf_mtc && !was_sending_qf_mtc) {
+                       /* we will re-start quarter-frame MTC this cycle, so send a full update to set things up */
+                       _send_timecode_update = true;
+               }
+
+               if (Config->get_send_mtc() && !_send_qf_mtc && _pframes_since_last_mtc > (frame_rate () / 4)) {
+                       /* we're sending MTC, but we're not sending QF MTC at the moment, and it's been
+                          a quarter of a second since we sent anything at all, so send a full MTC update
+                          this cycle.
+                       */
+                       _send_timecode_update = true;
+               }
+
+               _pframes_since_last_mtc += nframes;
+       }
+
+       /* Events caused a transport change (or we re-started sending
+        * MTC), so send an MTC Full Frame (Timecode) message.  This
+        * is sent whether rolling or not, to give slaves an idea of
+        * ardour time on locates (and allow slow slaves to position
+        * and prepare for rolling)
         */
        if (_send_timecode_update) {
-               send_full_time_code (_transport_frame);
+               send_full_time_code (_transport_frame, nframes);
        }
 
        if (!process_can_proceed()) {
@@ -279,15 +399,22 @@ Session::process_with_events (pframes_t nframes)
        }
 
        if (events.empty() || next_event == events.end()) {
-               process_without_events (nframes);
-               return;
+               try_run_lua (nframes); // also during export ?? ->move to process_without_events()
+               /* lua scripts may inject events */
+               while (_n_lua_scripts > 0 && pending_events.read (&ev, 1) == 1) {
+                       merge_event (ev);
+               }
+               if (events.empty() || next_event == events.end()) {
+                       process_without_events (nframes);
+                       return;
+               }
        }
 
        if (_transport_speed == 1.0) {
                frames_moved = (framecnt_t) nframes;
        } else {
-               interpolation.set_target_speed (fabs(_target_transport_speed));
-               interpolation.set_speed (fabs(_transport_speed));
+               interpolation.set_target_speed (_target_transport_speed);
+               interpolation.set_speed (_transport_speed);
                frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
        }
 
@@ -314,19 +441,12 @@ Session::process_with_events (pframes_t nframes)
                }
 
                if (!_exporting && !timecode_transmission_suspended()) {
-                       send_midi_time_code_for_cycle (nframes);
+                       send_midi_time_code_for_cycle (_transport_frame, end_frame, nframes);
                }
 
-               if (actively_recording()) {
-                       stop_limit = max_framepos;
-               } else {
+               ltc_tx_send_time_code_for_cycle (_transport_frame, end_frame, _target_transport_speed, _transport_speed, nframes);
 
-                       if (Config->get_stop_at_session_end()) {
-                               stop_limit = current_end_frame();
-                       } else {
-                               stop_limit = max_framepos;
-                       }
-               }
+               framepos_t stop_limit = compute_stop_limit ();
 
                if (maybe_stop (stop_limit)) {
                        no_roll (nframes);
@@ -353,6 +473,8 @@ Session::process_with_events (pframes_t nframes)
                                this_nframes = abs (floor(frames_moved / _transport_speed));
                        }
 
+                       try_run_lua (this_nframes);
+
                        if (this_nframes) {
 
                                click (_transport_frame, this_nframes);
@@ -376,7 +498,9 @@ Session::process_with_events (pframes_t nframes)
                                check_declick_out ();
                        }
 
-                       _engine.split_cycle (this_nframes);
+                       if (nframes > 0) {
+                               _engine.split_cycle (this_nframes);
+                       }
 
                        /* now handle this event and all others scheduled for the same time */
 
@@ -400,7 +524,6 @@ Session::process_with_events (pframes_t nframes)
 
                        /* this is necessary to handle the case of seamless looping */
                        end_frame = _transport_frame + floor (nframes * _transport_speed);
-
                }
 
                set_next_event ();
@@ -468,7 +591,9 @@ Session::follow_slave (pframes_t nframes)
                slave_speed = 0.0f;
        }
 
-       if (_slave->is_always_synced() || config.get_timecode_source_is_synced()) {
+       if (_slave->is_always_synced() ||
+                       (Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
+                       ) {
 
                /* if the TC source is synced, then we assume that its
                   speed is binary: 0.0 or 1.0
@@ -494,9 +619,11 @@ Session::follow_slave (pframes_t nframes)
 
        DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
                                                   _slave_state, slave_transport_frame, slave_speed, this_delta, average_slave_delta));
-                    
 
-       if (_slave_state == Running && !_slave->is_always_synced() && !config.get_timecode_source_is_synced()) {
+
+       if (_slave_state == Running && !_slave->is_always_synced() &&
+                       !(Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
+                       ) {
 
                if (_transport_speed != 0.0f) {
 
@@ -521,13 +648,13 @@ Session::follow_slave (pframes_t nframes)
                                                                           slave_speed,
                                                                           _transport_speed,
                                                                           _transport_frame,
-                                                                          slave_transport_frame, 
+                                                                          slave_transport_frame,
                                                                           average_slave_delta));
                        }
 #endif
-                       
+
                        if (_slave->give_slave_full_control_over_transport_speed()) {
-                               set_transport_speed (slave_speed, false, false);
+                               set_transport_speed (slave_speed, 0, false, false);
                                //std::cout << "set speed = " << slave_speed << "\n";
                        } else {
                                float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_frame_rate)));
@@ -536,9 +663,9 @@ Session::follow_slave (pframes_t nframes)
                                                                           delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
                                                                           slave_speed));
                        }
-                       
+
 #if 1
-                       if ((framecnt_t) abs(average_slave_delta) > _slave->resolution()) {
+                       if (!actively_recording() && (framecnt_t) abs(average_slave_delta) > _slave->resolution()) {
                                cerr << "average slave delta greater than slave resolution (" << _slave->resolution() << "), going to silent motion\n";
                                goto silent_motion;
                        }
@@ -591,7 +718,7 @@ Session::calculate_moving_average_of_slave_delta (int dir, framecnt_t this_delta
 }
 
 void
-Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame, framecnt_t this_delta)
+Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame, framecnt_t /*this_delta*/)
 {
        if (slave_speed != 0.0f) {
 
@@ -608,7 +735,10 @@ Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame,
 
                        } else {
 
-                               _slave_state = Running;
+                               DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped -> running at %1\n", slave_transport_frame));
+
+                               memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
+                               average_slave_delta = 0L;
 
                                Location* al = _locations->auto_loop_location();
 
@@ -618,8 +748,10 @@ Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame,
                                }
 
                                if (slave_transport_frame != _transport_frame) {
+                                       DEBUG_TRACE (DEBUG::Slave, string_compose ("require locate to run. eng: %1 -> sl: %2\n", _transport_frame, slave_transport_frame));
                                        locate (slave_transport_frame, false, false);
                                }
+                               _slave_state = Running;
                        }
                        break;
 
@@ -668,10 +800,6 @@ Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame,
                                        cerr << "cannot micro-seek\n";
                                        /* XXX what? */
                                }
-
-                               memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
-                               average_slave_delta = 0L;
-                               this_delta = 0;
                        }
                }
 
@@ -686,7 +814,7 @@ Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame,
 
                if (_transport_speed != 0.0f) {
                        DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 frame %2 tf %3\n", slave_speed, slave_transport_frame, _transport_frame));
-                       stop_transport();
+                       stop_transport ();
                }
 
                if (slave_transport_frame != _transport_frame) {
@@ -694,7 +822,7 @@ Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame,
                        force_locate (slave_transport_frame, false);
                }
 
-               _slave_state = Stopped;
+               reset_slave_state();
        }
 }
 
@@ -707,7 +835,7 @@ Session::follow_slave_silently (pframes_t nframes, float slave_speed)
                   for now.
                */
 
-               bool need_butler;
+               bool need_butler = false;
 
                silent_process_routes (nframes, need_butler);
 
@@ -724,19 +852,8 @@ Session::follow_slave_silently (pframes_t nframes, float slave_speed)
                } else {
                        increment_transport_position (frames_moved);
                }
-                
-               framepos_t stop_limit;
-
-               if (actively_recording()) {
-                       stop_limit = max_framepos;
-               } else {
-                       if (Config->get_stop_at_session_end()) {
-                               stop_limit = current_end_frame();
-                       } else {
-                               stop_limit = max_framepos;
-                       }
-               }
 
+               framepos_t const stop_limit = compute_stop_limit ();
                maybe_stop (stop_limit);
        }
 }
@@ -745,7 +862,6 @@ void
 Session::process_without_events (pframes_t nframes)
 {
        bool session_needs_butler = false;
-       framepos_t stop_limit;
        framecnt_t frames_moved;
 
        if (!process_can_proceed()) {
@@ -755,6 +871,7 @@ Session::process_without_events (pframes_t nframes)
 
        if (!_exporting && _slave) {
                if (!follow_slave (nframes)) {
+                       ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame, 0, 0 , nframes);
                        return;
                }
        }
@@ -764,20 +881,22 @@ Session::process_without_events (pframes_t nframes)
                return;
        }
 
-       if (!_exporting && !timecode_transmission_suspended()) {
-               send_midi_time_code_for_cycle (nframes);
+       if (_transport_speed == 1.0) {
+               frames_moved = (framecnt_t) nframes;
+       } else {
+               interpolation.set_target_speed (_target_transport_speed);
+               interpolation.set_speed (_transport_speed);
+               frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
        }
 
-       if (actively_recording()) {
-               stop_limit = max_framepos;
-       } else {
-               if (Config->get_stop_at_session_end()) {
-                       stop_limit = current_end_frame();
-               } else {
-                       stop_limit = max_framepos;
-               }
+       if (!_exporting && !timecode_transmission_suspended()) {
+               send_midi_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, nframes);
        }
 
+       ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, _target_transport_speed, _transport_speed, nframes);
+
+       framepos_t const stop_limit = compute_stop_limit ();
+
        if (maybe_stop (stop_limit)) {
                fail_roll (nframes);
                return;
@@ -789,14 +908,6 @@ Session::process_without_events (pframes_t nframes)
 
        click (_transport_frame, nframes);
 
-       if (_transport_speed == 1.0) {
-               frames_moved = (framecnt_t) nframes;
-       } else {
-               interpolation.set_target_speed (fabs(_target_transport_speed));
-               interpolation.set_speed (fabs(_transport_speed));
-               frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
-       }
-
        if (process_routes (nframes, session_needs_butler)) {
                fail_roll (nframes);
                return;
@@ -828,7 +939,7 @@ Session::process_audition (pframes_t nframes)
        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)->silence (nframes);
                }
        }
@@ -839,12 +950,12 @@ Session::process_audition (pframes_t nframes)
                _butler->summon ();
        }
 
-        /* if using a monitor section, run it because otherwise we don't hear anything */
+       /* if using a monitor section, run it because otherwise we don't hear anything */
+
+       if (_monitor_out && auditioner->needs_monitor()) {
+               _monitor_out->monitor_run (_transport_frame, _transport_frame + nframes, nframes, false);
+       }
 
-        if (auditioner->needs_monitor()) {
-                _monitor_out->passthru (_transport_frame, _transport_frame + nframes, nframes, false);
-        }
-        
        /* handle pending events */
 
        while (pending_events.read (&ev, 1) == 1) {
@@ -886,7 +997,7 @@ Session::maybe_sync_start (pframes_t & nframes)
 
                no_roll (sync_offset);
                nframes -= sync_offset;
-               AudioPort::increment_port_offset (sync_offset);
+               Port::increment_global_port_buffer_offset (sync_offset);
                waiting_for_sync_offset = false;
 
                if (nframes == 0) {
@@ -976,23 +1087,37 @@ Session::process_event (SessionEvent* ev)
 
        switch (ev->type) {
        case SessionEvent::SetLoop:
-               set_play_loop (ev->yes_or_no);
+               set_play_loop (ev->yes_or_no, ev->speed);
                break;
 
        case SessionEvent::AutoLoop:
                if (play_loop) {
+                       /* roll after locate, do not flush, set "with loop"
+                          true only if we are seamless looping
+                       */
                        start_locate (ev->target_frame, true, false, Config->get_seamless_loop());
                }
                remove = false;
                del = false;
                break;
 
+       case SessionEvent::AutoLoopDeclick:
+               if (play_loop) {
+                       /* Request a declick fade-out and a fade-in; the fade-out will happen
+                          at the end of the loop, and the fade-in at the start.
+                       */
+                       transport_sub_state |= (PendingLoopDeclickOut | PendingLoopDeclickIn);
+               }
+               remove = false;
+               del = false;
+               break;
+
        case SessionEvent::Locate:
                if (ev->yes_or_no) {
-                       // cerr << "forced locate to " << ev->target_frame << endl;
+                       /* args: do not roll after locate, do flush, not with loop */
                        locate (ev->target_frame, false, true, false);
                } else {
-                       // cerr << "soft locate to " << ev->target_frame << endl;
+                       /* args: do not roll after locate, do flush, not with loop */
                        start_locate (ev->target_frame, false, true, false);
                }
                _send_timecode_update = true;
@@ -1000,15 +1125,24 @@ Session::process_event (SessionEvent* ev)
 
        case SessionEvent::LocateRoll:
                if (ev->yes_or_no) {
-                       // cerr << "forced locate to+roll " << ev->target_frame << endl;
+                       /* args: roll after locate, do flush, not with loop */
                        locate (ev->target_frame, true, true, false);
                } else {
-                       // cerr << "soft locate to+roll " << ev->target_frame << endl;
+                       /* args: roll after locate, do flush, not with loop */
                        start_locate (ev->target_frame, true, true, false);
                }
                _send_timecode_update = true;
                break;
 
+       case SessionEvent::Skip:
+               if (Config->get_skip_playback()) {
+                       start_locate (ev->target_frame, true, true, false);
+                       _send_timecode_update = true;
+               }
+               remove = false;
+               del = false;
+               break;
+
        case SessionEvent::LocateRollLocate:
                // locate is handled by ::request_roll_at_and_return()
                _requested_return_frame = ev->target_frame;
@@ -1017,12 +1151,12 @@ Session::process_event (SessionEvent* ev)
 
 
        case SessionEvent::SetTransportSpeed:
-               set_transport_speed (ev->speed, ev->yes_or_no, ev->second_yes_or_no);
+               set_transport_speed (ev->speed, ev->target_frame, ev->yes_or_no, ev->second_yes_or_no, ev->third_yes_or_no);
                break;
 
        case SessionEvent::PunchIn:
                // cerr << "PunchIN at " << transport_frame() << endl;
-               if (config.get_punch_in() && record_status() == Enabled) {
+               if (config.get_punch_in() && record_status() == Enabled && !preroll_record_punch_enabled()) {
                        enable_record ();
                }
                remove = false;
@@ -1031,17 +1165,25 @@ Session::process_event (SessionEvent* ev)
 
        case SessionEvent::PunchOut:
                // cerr << "PunchOUT at " << transport_frame() << endl;
-               if (config.get_punch_out()) {
+               if (config.get_punch_out() && !preroll_record_punch_enabled()) {
                        step_back_from_record ();
                }
                remove = false;
                del = false;
                break;
 
+       case SessionEvent::RecordStart:
+               if (preroll_record_punch_enabled() && record_status() == Enabled) {
+                       enable_record ();
+               }
+               remove = false;
+               del = false;
+               break;
+
        case SessionEvent::StopOnce:
                if (!non_realtime_work_pending()) {
-                       stop_transport (ev->yes_or_no);
                        _clear_event_type (SessionEvent::StopOnce);
+                       stop_transport (ev->yes_or_no);
                }
                remove = false;
                del = false;
@@ -1056,6 +1198,7 @@ Session::process_event (SessionEvent* ev)
                break;
 
        case SessionEvent::RangeLocate:
+               /* args: roll after locate, do flush, not with loop */
                start_locate (ev->target_frame, true, true, false);
                remove = false;
                del = false;
@@ -1070,6 +1213,7 @@ Session::process_event (SessionEvent* ev)
                break;
 
        case SessionEvent::SetSyncSource:
+               DEBUG_TRACE (DEBUG::Slave, "seen request for new slave\n");
                use_sync_source (ev->slave);
                break;
 
@@ -1088,18 +1232,22 @@ Session::process_event (SessionEvent* ev)
                set_play_range (ev->audio_range, (ev->speed == 1.0f));
                break;
 
+       case SessionEvent::CancelPlayAudioRange:
+               unset_play_range();
+               break;
+
        case SessionEvent::RealTimeOperation:
                process_rtop (ev);
                del = false; // other side of RT request needs to clean up
                break;
 
-        case SessionEvent::AdjustPlaybackBuffering:
-                schedule_playback_buffering_adjustment ();
-                break;
+       case SessionEvent::AdjustPlaybackBuffering:
+               schedule_playback_buffering_adjustment ();
+               break;
 
-        case SessionEvent::AdjustCaptureBuffering:
-                schedule_capture_buffering_adjustment ();
-                break;
+       case SessionEvent::AdjustCaptureBuffering:
+               schedule_capture_buffering_adjustment ();
+               break;
 
        case SessionEvent::SetTimecodeTransmission:
                g_atomic_int_set (&_suspend_timecode_transmission, ev->yes_or_no ? 0 : 1);
@@ -1107,7 +1255,7 @@ Session::process_event (SessionEvent* ev)
 
        default:
          fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
-               /*NOTREACHED*/
+               abort(); /*NOTREACHED*/
                break;
        };
 
@@ -1120,3 +1268,110 @@ Session::process_event (SessionEvent* ev)
        }
 }
 
+framepos_t
+Session::compute_stop_limit () const
+{
+       if (!Config->get_stop_at_session_end ()) {
+               return max_framepos;
+       }
+
+       if (_slave) {
+               return max_framepos;
+       }
+
+       if (preroll_record_punch_enabled ()) {
+               return max_framepos;
+       }
+
+       bool const punching_in = (config.get_punch_in () && _locations->auto_punch_location());
+       bool const punching_out = (config.get_punch_out () && _locations->auto_punch_location());
+
+       if (actively_recording ()) {
+               /* permanently recording */
+               return max_framepos;
+       } else if (punching_in && !punching_out) {
+               /* punching in but never out */
+               return max_framepos;
+       } else if (punching_in && punching_out && _locations->auto_punch_location()->end() > current_end_frame()) {
+               /* punching in and punching out after session end */
+               return max_framepos;
+       }
+
+       return current_end_frame ();
+}
+
+
+
+/* dedicated thread for signal emission.
+ *
+ * while sending cross-thread signals from the process thread
+ * is fine in general, PBD::Signal's use of boost::function and
+ * boost:bind can produce a vast overhead which is not
+ * acceptable for low latency.
+ *
+ * This works around the issue by moving the boost overhead
+ * out of the RT thread. The overall load is probably higher but
+ * the realtime thread remains unaffected.
+ */
+
+void
+Session::emit_route_signals ()
+{
+       // TODO use RAII to allow using these signals in other places
+       BatchUpdateStart(); /* EMIT SIGNAL */
+       boost::shared_ptr<RouteList> r = routes.reader ();
+       for (RouteList::const_iterator ci = r->begin(); ci != r->end(); ++ci) {
+               (*ci)->emit_pending_signals ();
+       }
+       BatchUpdateEnd(); /* EMIT SIGNAL */
+}
+
+void
+Session::emit_thread_start ()
+{
+       if (_rt_thread_active) {
+               return;
+       }
+       _rt_thread_active = true;
+
+       if (pthread_create (&_rt_emit_thread, NULL, emit_thread, this)) {
+               _rt_thread_active = false;
+       }
+}
+
+void
+Session::emit_thread_terminate ()
+{
+       if (!_rt_thread_active) {
+               return;
+       }
+       _rt_thread_active = false;
+
+       if (pthread_mutex_lock (&_rt_emit_mutex) == 0) {
+               pthread_cond_signal (&_rt_emit_cond);
+               pthread_mutex_unlock (&_rt_emit_mutex);
+       }
+
+       void *status;
+       pthread_join (_rt_emit_thread, &status);
+}
+
+void *
+Session::emit_thread (void *arg)
+{
+       Session *s = static_cast<Session *>(arg);
+       s->emit_thread_run ();
+       pthread_exit (0);
+       return 0;
+}
+
+void
+Session::emit_thread_run ()
+{
+       pthread_mutex_lock (&_rt_emit_mutex);
+       while (_rt_thread_active) {
+               emit_route_signals();
+               pthread_cond_wait (&_rt_emit_cond, &_rt_emit_mutex);
+       }
+       pthread_mutex_unlock (&_rt_emit_mutex);
+}