rationalize (a bit) engine start/stop/restart so that it is possible to start up...
[ardour.git] / libs / ardour / session_process.cc
1 /*
2     Copyright (C) 1999-2002 Paul Davis
3
4     This program is free software; you can redistribute it and/or modify
5     it under the terms of the GNU General Public License as published by
6     the Free Software Foundation; either version 2 of the License, or
7     (at your option) any later version.
8
9     This program is distributed in the hope that it will be useful,
10     but WITHOUT ANY WARRANTY; without even the implied warranty of
11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12     GNU General Public License for more details.
13
14     You should have received a copy of the GNU General Public License
15     along with this program; if not, write to the Free Software
16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17
18 */
19
20 #include <cmath>
21 #include <cerrno>
22 #include <algorithm>
23 #include <unistd.h>
24
25 #include "pbd/error.h"
26 #include "pbd/enumwriter.h"
27
28 #include <glibmm/threads.h>
29
30 #include "ardour/audioengine.h"
31 #include "ardour/auditioner.h"
32 #include "ardour/butler.h"
33 #include "ardour/cycle_timer.h"
34 #include "ardour/debug.h"
35 #include "ardour/graph.h"
36 #include "ardour/port.h"
37 #include "ardour/process_thread.h"
38 #include "ardour/session.h"
39 #include "ardour/slave.h"
40 #include "ardour/ticker.h"
41 #include "ardour/types.h"
42
43 #include "midi++/mmc.h"
44
45 #include "i18n.h"
46
47 using namespace ARDOUR;
48 using namespace PBD;
49 using namespace std;
50
51 /** Called by the audio engine when there is work to be done with JACK.
52  * @param nframes Number of frames to process.
53  */
54
55 void
56 Session::process (pframes_t nframes)
57 {
58         framepos_t transport_at_start = _transport_frame;
59
60         _silent = false;
61
62         if (processing_blocked()) {
63                 _silent = true;
64                 return;
65         }
66
67         if (non_realtime_work_pending()) {
68                 if (!_butler->transport_work_requested ()) {
69                         post_transport ();
70                 }
71         }
72
73         _engine.main_thread()->get_buffers ();
74
75         (this->*process_function) (nframes);
76
77         _engine.main_thread()->drop_buffers ();
78
79         /* deliver MIDI clock. Note that we need to use the transport frame
80          * position at the start of process(), not the value at the end of
81          * it. We may already have ticked() because of a transport state
82          * change, for example.
83          */
84
85         try {
86                 if (!_engine.freewheeling() && Config->get_send_midi_clock() && transport_speed() == 1.0f && midi_clock->has_midi_port()) {
87                         midi_clock->tick (transport_at_start, nframes);
88                 }
89         } catch (...) {
90                 /* don't bother with a message */
91         }
92
93         SendFeedback (); /* EMIT SIGNAL */
94 }
95
96 int
97 Session::fail_roll (pframes_t nframes)
98 {
99         return no_roll (nframes);
100 }
101
102 int
103 Session::no_roll (pframes_t nframes)
104 {
105         PT_TIMING_CHECK (4);
106         
107         framepos_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
108         int ret = 0;
109         int declick = get_transport_declick_required();
110         boost::shared_ptr<RouteList> r = routes.reader ();
111
112         if (_click_io) {
113                 _click_io->silence (nframes);
114         }
115
116         ltc_tx_send_time_code_for_cycle (_transport_frame, end_frame, _target_transport_speed, _transport_speed, nframes);
117
118         if (_process_graph) {
119                 DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/no-roll\n");
120                 _process_graph->routes_no_roll( nframes, _transport_frame, end_frame, non_realtime_work_pending(), declick);
121         } else {
122                 PT_TIMING_CHECK (10);
123                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
124
125                         if ((*i)->is_auditioner()) {
126                                 continue;
127                         }
128
129                         (*i)->set_pending_declick (declick);
130
131                         if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending())) {
132                                 error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
133                                 ret = -1;
134                                 break;
135                         }
136                 }
137                 PT_TIMING_CHECK (11);
138         }
139
140         PT_TIMING_CHECK (5);
141         return ret;
142 }
143
144 /** @param need_butler to be set to true by this method if it needs the butler,
145  *  otherwise it must be left alone.
146  */
147 int
148 Session::process_routes (pframes_t nframes, bool& need_butler)
149 {
150         int  declick = get_transport_declick_required();
151         boost::shared_ptr<RouteList> r = routes.reader ();
152
153         if (transport_sub_state & StopPendingCapture) {
154                 /* force a declick out */
155                 declick = -1;
156         }
157
158         const framepos_t start_frame = _transport_frame;
159         const framepos_t end_frame = _transport_frame + floor (nframes * _transport_speed);
160         
161         if (_process_graph) {
162                 DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/process-routes\n");
163                 _process_graph->process_routes (nframes, start_frame, end_frame, declick, need_butler);
164         } else {
165
166                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
167
168                         int ret;
169
170                         if ((*i)->is_auditioner()) {
171                                 continue;
172                         }
173
174                         (*i)->set_pending_declick (declick);
175
176                         bool b = false;
177
178                         if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, b)) < 0) {
179                                 stop_transport ();
180                                 return -1;
181                         }
182
183                         if (b) {
184                                 need_butler = true;
185                         }
186                 }
187         }
188
189         return 0;
190 }
191
192 /** @param need_butler to be set to true by this method if it needs the butler,
193  *  otherwise it must be left alone.
194  */
195 int
196 Session::silent_process_routes (pframes_t nframes, bool& need_butler)
197 {
198         boost::shared_ptr<RouteList> r = routes.reader ();
199
200         const framepos_t start_frame = _transport_frame;
201         const framepos_t end_frame = _transport_frame + lrintf(nframes * _transport_speed);
202
203         if (_process_graph) {
204                 _process_graph->silent_process_routes (nframes, start_frame, end_frame, need_butler);
205         } else {
206                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
207
208                         int ret;
209
210                         if ((*i)->is_auditioner()) {
211                                 continue;
212                         }
213
214                         bool b = false;
215
216                         if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, b)) < 0) {
217                                 stop_transport ();
218                                 return -1;
219                         }
220
221                         if (b) {
222                                 need_butler = true;
223                         }
224                 }
225         }
226
227         return 0;
228 }
229
230 void
231 Session::get_track_statistics ()
232 {
233         float pworst = 1.0f;
234         float cworst = 1.0f;
235
236         boost::shared_ptr<RouteList> rl = routes.reader();
237         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
238
239                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
240
241                 if (!tr || tr->hidden()) {
242                         continue;
243                 }
244
245                 pworst = min (pworst, tr->playback_buffer_load());
246                 cworst = min (cworst, tr->capture_buffer_load());
247         }
248
249         g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
250         g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
251
252         if (actively_recording()) {
253                 set_dirty();
254         }
255 }
256
257 /** Process callback used when the auditioner is not active */
258 void
259 Session::process_with_events (pframes_t nframes)
260 {
261         PT_TIMING_CHECK (3);
262         
263         SessionEvent*  ev;
264         pframes_t      this_nframes;
265         framepos_t     end_frame;
266         bool           session_needs_butler = false;
267         framecnt_t     frames_moved;
268
269         /* make sure the auditioner is silent */
270
271         if (auditioner) {
272                 auditioner->silence (nframes);
273         }
274
275         /* handle any pending events */
276
277         while (pending_events.read (&ev, 1) == 1) {
278                 merge_event (ev);
279         }
280
281         /* if we are not in the middle of a state change,
282            and there are immediate events queued up,
283            process them.
284         */
285
286         while (!non_realtime_work_pending() && !immediate_events.empty()) {
287                 SessionEvent *ev = immediate_events.front ();
288                 immediate_events.pop_front ();
289                 process_event (ev);
290         }
291
292         /* Decide on what to do with quarter-frame MTC during this cycle */
293
294         bool const was_sending_qf_mtc = _send_qf_mtc;
295         double const tolerance = Config->get_mtc_qf_speed_tolerance() / 100.0;
296
297         if (_transport_speed != 0) {
298                 _send_qf_mtc = (
299                         Config->get_send_mtc () &&
300                         _transport_speed >= (1 - tolerance) &&
301                         _transport_speed <= (1 + tolerance)
302                         );
303
304                 if (_send_qf_mtc && !was_sending_qf_mtc) {
305                         /* we will re-start quarter-frame MTC this cycle, so send a full update to set things up */
306                         _send_timecode_update = true;
307                 }
308
309                 if (Config->get_send_mtc() && !_send_qf_mtc && _pframes_since_last_mtc > (frame_rate () / 4)) {
310                         /* we're sending MTC, but we're not sending QF MTC at the moment, and it's been
311                            a quarter of a second since we sent anything at all, so send a full MTC update
312                            this cycle.
313                         */
314                         _send_timecode_update = true;
315                 }
316
317                 _pframes_since_last_mtc += nframes;
318         }
319
320         /* Events caused a transport change (or we re-started sending
321          * MTC), so send an MTC Full Frame (Timecode) message.  This
322          * is sent whether rolling or not, to give slaves an idea of
323          * ardour time on locates (and allow slow slaves to position
324          * and prepare for rolling)
325          */
326         if (_send_timecode_update) {
327                 send_full_time_code (_transport_frame, nframes);
328         }
329
330         if (!process_can_proceed()) {
331                 _silent = true;
332                 return;
333         }
334
335         if (events.empty() || next_event == events.end()) {
336                 process_without_events (nframes);
337                 return;
338         }
339
340         if (_transport_speed == 1.0) {
341                 frames_moved = (framecnt_t) nframes;
342         } else {
343                 interpolation.set_target_speed (_target_transport_speed);
344                 interpolation.set_speed (_transport_speed);
345                 frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
346         }
347
348         end_frame = _transport_frame + frames_moved;
349
350         {
351                 SessionEvent* this_event;
352                 Events::iterator the_next_one;
353
354                 if (!process_can_proceed()) {
355                         _silent = true;
356                         return;
357                 }
358
359                 if (!_exporting && _slave) {
360                         if (!follow_slave (nframes)) {
361                                 return;
362                         }
363                 }
364
365                 if (_transport_speed == 0) {
366                         no_roll (nframes);
367                         return;
368                 }
369
370                 if (!_exporting && !timecode_transmission_suspended()) {
371                         send_midi_time_code_for_cycle (_transport_frame, end_frame, nframes);
372                 }
373
374                 framepos_t stop_limit = compute_stop_limit ();
375
376                 if (maybe_stop (stop_limit)) {
377                         no_roll (nframes);
378                         return;
379                 }
380
381                 this_event = *next_event;
382                 the_next_one = next_event;
383                 ++the_next_one;
384
385                 /* yes folks, here it is, the actual loop where we really truly
386                    process some audio
387                 */
388
389                 while (nframes) {
390
391                         this_nframes = nframes; /* real (jack) time relative */
392                         frames_moved = (framecnt_t) floor (_transport_speed * nframes); /* transport relative */
393
394                         /* running an event, position transport precisely to its time */
395                         if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
396                                 /* this isn't quite right for reverse play */
397                                 frames_moved = (framecnt_t) (this_event->action_frame - _transport_frame);
398                                 this_nframes = abs (floor(frames_moved / _transport_speed));
399                         }
400
401                         if (this_nframes) {
402
403                                 click (_transport_frame, this_nframes);
404
405                                 if (process_routes (this_nframes, session_needs_butler)) {
406                                         fail_roll (nframes);
407                                         return;
408                                 }
409
410                                 get_track_statistics ();
411
412                                 nframes -= this_nframes;
413
414                                 if (frames_moved < 0) {
415                                         decrement_transport_position (-frames_moved);
416                                 } else {
417                                         increment_transport_position (frames_moved);
418                                 }
419
420                                 maybe_stop (stop_limit);
421                                 check_declick_out ();
422                         }
423
424                         _engine.split_cycle (this_nframes);
425
426                         /* now handle this event and all others scheduled for the same time */
427
428                         while (this_event && this_event->action_frame == _transport_frame) {
429                                 process_event (this_event);
430
431                                 if (the_next_one == events.end()) {
432                                         this_event = 0;
433                                 } else {
434                                         this_event = *the_next_one;
435                                         ++the_next_one;
436                                 }
437                         }
438
439                         /* if an event left our state changing, do the right thing */
440
441                         if (nframes && non_realtime_work_pending()) {
442                                 no_roll (nframes);
443                                 break;
444                         }
445
446                         /* this is necessary to handle the case of seamless looping */
447                         end_frame = _transport_frame + floor (nframes * _transport_speed);
448                 }
449
450                 set_next_event ();
451
452         } /* implicit release of route lock */
453
454         if (session_needs_butler) {
455                 _butler->summon ();
456         }
457 }
458
459 void
460 Session::reset_slave_state ()
461 {
462         average_slave_delta = 1800;
463         delta_accumulator_cnt = 0;
464         have_first_delta_accumulator = false;
465         _slave_state = Stopped;
466 }
467
468 bool
469 Session::transport_locked () const
470 {
471         Slave* sl = _slave;
472
473         if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
474                 return true;
475         }
476
477         return false;
478 }
479
480 bool
481 Session::follow_slave (pframes_t nframes)
482 {
483         double slave_speed;
484         framepos_t slave_transport_frame;
485         framecnt_t this_delta;
486         int dir;
487
488         if (!_slave->ok()) {
489                 stop_transport ();
490                 config.set_external_sync (false);
491                 goto noroll;
492         }
493
494         _slave->process (nframes);
495         _slave->speed_and_position (slave_speed, slave_transport_frame);
496
497         DEBUG_TRACE (DEBUG::Slave, string_compose ("Slave position %1 speed %2\n", slave_transport_frame, slave_speed));
498
499         if (!_slave->locked()) {
500                 DEBUG_TRACE (DEBUG::Slave, "slave not locked\n");
501                 goto noroll;
502         }
503
504         if (slave_transport_frame > _transport_frame) {
505                 this_delta = slave_transport_frame - _transport_frame;
506                 dir = 1;
507         } else {
508                 this_delta = _transport_frame - slave_transport_frame;
509                 dir = -1;
510         }
511
512         if (_slave->starting()) {
513                 slave_speed = 0.0f;
514         }
515
516         if (_slave->is_always_synced() ||
517                         (Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
518                         ) {
519
520                 /* if the TC source is synced, then we assume that its
521                    speed is binary: 0.0 or 1.0
522                 */
523
524                 if (slave_speed != 0.0f) {
525                         slave_speed = 1.0f;
526                 }
527
528         } else {
529
530                 /* if we are chasing and the average delta between us and the
531                    master gets too big, we want to switch to silent
532                    motion. so keep track of that here.
533                 */
534
535                 if (_slave_state == Running) {
536                         calculate_moving_average_of_slave_delta(dir, this_delta);
537                 }
538         }
539
540         track_slave_state (slave_speed, slave_transport_frame, this_delta);
541
542         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
543                                                    _slave_state, slave_transport_frame, slave_speed, this_delta, average_slave_delta));
544
545
546         if (_slave_state == Running && !_slave->is_always_synced() &&
547                         !(Config->get_timecode_source_is_synced() && (dynamic_cast<TimecodeSlave*>(_slave)) != 0)
548                         ) {
549
550                 if (_transport_speed != 0.0f) {
551
552                         /*
553                            note that average_dir is +1 or -1
554                         */
555
556                         float delta;
557
558                         if (average_slave_delta == 0) {
559                                 delta = this_delta;
560                                 delta *= dir;
561                         } else {
562                                 delta = average_slave_delta;
563                                 delta *= average_dir;
564                         }
565
566 #ifndef NDEBUG
567                         if (slave_speed != 0.0) {
568                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("delta = %1 speed = %2 ts = %3 M@%4 S@%5 avgdelta %6\n",
569                                                                            (int) (dir * this_delta),
570                                                                            slave_speed,
571                                                                            _transport_speed,
572                                                                            _transport_frame,
573                                                                            slave_transport_frame,
574                                                                            average_slave_delta));
575                         }
576 #endif
577
578                         if (_slave->give_slave_full_control_over_transport_speed()) {
579                                 set_transport_speed (slave_speed, false, false);
580                                 //std::cout << "set speed = " << slave_speed << "\n";
581                         } else {
582                                 float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_frame_rate)));
583                                 request_transport_speed (adjusted_speed);
584                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("adjust using %1 towards %2 ratio %3 current %4 slave @ %5\n",
585                                                                            delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
586                                                                            slave_speed));
587                         }
588
589 #if 1
590                         if (!actively_recording() && (framecnt_t) abs(average_slave_delta) > _slave->resolution()) {
591                                 cerr << "average slave delta greater than slave resolution (" << _slave->resolution() << "), going to silent motion\n";
592                                 goto silent_motion;
593                         }
594 #endif
595                 }
596         }
597
598
599         if (_slave_state == Running && !non_realtime_work_pending()) {
600                 /* speed is set, we're locked, and good to go */
601                 return true;
602         }
603
604   silent_motion:
605         DEBUG_TRACE (DEBUG::Slave, "silent motion\n")
606         follow_slave_silently (nframes, slave_speed);
607
608   noroll:
609         /* don't move at all */
610         DEBUG_TRACE (DEBUG::Slave, "no roll\n")
611         no_roll (nframes);
612         return false;
613 }
614
615 void
616 Session::calculate_moving_average_of_slave_delta (int dir, framecnt_t this_delta)
617 {
618         if (delta_accumulator_cnt >= delta_accumulator_size) {
619                 have_first_delta_accumulator = true;
620                 delta_accumulator_cnt = 0;
621         }
622
623         if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
624                 delta_accumulator[delta_accumulator_cnt++] = (framecnt_t) dir *  (framecnt_t) this_delta;
625         }
626
627         if (have_first_delta_accumulator) {
628                 average_slave_delta = 0L;
629                 for (int i = 0; i < delta_accumulator_size; ++i) {
630                         average_slave_delta += delta_accumulator[i];
631                 }
632                 average_slave_delta /= (int32_t) delta_accumulator_size;
633                 if (average_slave_delta < 0L) {
634                         average_dir = -1;
635                         average_slave_delta = abs(average_slave_delta);
636                 } else {
637                         average_dir = 1;
638                 }
639         }
640 }
641
642 void
643 Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame, framecnt_t /*this_delta*/)
644 {
645         if (slave_speed != 0.0f) {
646
647                 /* slave is running */
648
649                 switch (_slave_state) {
650                 case Stopped:
651                         if (_slave->requires_seekahead()) {
652                                 slave_wait_end = slave_transport_frame + _slave->seekahead_distance ();
653                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, but running, requires seekahead to %1\n", slave_wait_end));
654                                 /* we can call locate() here because we are in process context */
655                                 locate (slave_wait_end, false, false);
656                                 _slave_state = Waiting;
657
658                         } else {
659
660                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped -> running at %1\n", slave_transport_frame));
661
662                                 memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
663                                 average_slave_delta = 0L;
664
665                                 Location* al = _locations->auto_loop_location();
666
667                                 if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
668                                         // cancel looping
669                                         request_play_loop(false);
670                                 }
671
672                                 if (slave_transport_frame != _transport_frame) {
673                                         DEBUG_TRACE (DEBUG::Slave, string_compose ("require locate to run. eng: %1 -> sl: %2\n", _transport_frame, slave_transport_frame));
674                                         locate (slave_transport_frame, false, false);
675                                 }
676                                 _slave_state = Running;
677                         }
678                         break;
679
680                 case Waiting:
681                 default:
682                         break;
683                 }
684
685                 if (_slave_state == Waiting) {
686
687                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave waiting at %1\n", slave_transport_frame));
688
689                         if (slave_transport_frame >= slave_wait_end) {
690
691                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave start at %1 vs %2\n", slave_transport_frame, _transport_frame));
692
693                                 _slave_state = Running;
694
695                                 /* now perform a "micro-seek" within the disk buffers to realign ourselves
696                                    precisely with the master.
697                                 */
698
699
700                                 bool ok = true;
701                                 framecnt_t frame_delta = slave_transport_frame - _transport_frame;
702
703                                 boost::shared_ptr<RouteList> rl = routes.reader();
704                                 for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
705                                         boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
706                                         if (tr && !tr->can_internal_playback_seek (frame_delta)) {
707                                                 ok = false;
708                                                 break;
709                                         }
710                                 }
711
712                                 if (ok) {
713                                         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
714                                                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
715                                                 if (tr) {
716                                                         tr->internal_playback_seek (frame_delta);
717                                                 }
718                                         }
719                                         _transport_frame += frame_delta;
720
721                                 } else {
722                                         cerr << "cannot micro-seek\n";
723                                         /* XXX what? */
724                                 }
725                         }
726                 }
727
728                 if (_slave_state == Running && _transport_speed == 0.0f) {
729                         DEBUG_TRACE (DEBUG::Slave, "slave starts transport\n");
730                         start_transport ();
731                 }
732
733         } else { // slave_speed is 0
734
735                 /* slave has stopped */
736
737                 if (_transport_speed != 0.0f) {
738                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 frame %2 tf %3\n", slave_speed, slave_transport_frame, _transport_frame));
739                         stop_transport ();
740                 }
741
742                 if (slave_transport_frame != _transport_frame) {
743                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, move to %1\n", slave_transport_frame));
744                         force_locate (slave_transport_frame, false);
745                 }
746
747                 reset_slave_state();
748         }
749 }
750
751 void
752 Session::follow_slave_silently (pframes_t nframes, float slave_speed)
753 {
754         if (slave_speed && _transport_speed) {
755
756                 /* something isn't right, but we should move with the master
757                    for now.
758                 */
759
760                 bool need_butler;
761
762                 silent_process_routes (nframes, need_butler);
763
764                 get_track_statistics ();
765
766                 if (need_butler) {
767                         _butler->summon ();
768                 }
769
770                 int32_t frames_moved = (int32_t) floor (_transport_speed * nframes);
771
772                 if (frames_moved < 0) {
773                         decrement_transport_position (-frames_moved);
774                 } else {
775                         increment_transport_position (frames_moved);
776                 }
777
778                 framepos_t const stop_limit = compute_stop_limit ();
779                 maybe_stop (stop_limit);
780         }
781 }
782
783 void
784 Session::process_without_events (pframes_t nframes)
785 {
786         bool session_needs_butler = false;
787         framecnt_t frames_moved;
788
789         if (!process_can_proceed()) {
790                 _silent = true;
791                 return;
792         }
793
794         if (!_exporting && _slave) {
795                 if (!follow_slave (nframes)) {
796                         ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame, 0, 0 , nframes);
797                         return;
798                 }
799         }
800
801         if (_transport_speed == 0) {
802                 fail_roll (nframes);
803                 return;
804         }
805
806         if (_transport_speed == 1.0) {
807                 frames_moved = (framecnt_t) nframes;
808         } else {
809                 interpolation.set_target_speed (_target_transport_speed);
810                 interpolation.set_speed (_transport_speed);
811                 frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
812         }
813
814         if (!_exporting && !timecode_transmission_suspended()) {
815                 send_midi_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, nframes);
816         }
817
818         ltc_tx_send_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, _target_transport_speed, _transport_speed, nframes);
819
820         framepos_t const stop_limit = compute_stop_limit ();
821
822         if (maybe_stop (stop_limit)) {
823                 fail_roll (nframes);
824                 return;
825         }
826
827         if (maybe_sync_start (nframes)) {
828                 return;
829         }
830
831         click (_transport_frame, nframes);
832
833         if (process_routes (nframes, session_needs_butler)) {
834                 fail_roll (nframes);
835                 return;
836         }
837
838         get_track_statistics ();
839
840         if (frames_moved < 0) {
841                 decrement_transport_position (-frames_moved);
842         } else {
843                 increment_transport_position (frames_moved);
844         }
845
846         maybe_stop (stop_limit);
847         check_declick_out ();
848
849         if (session_needs_butler) {
850                 _butler->summon ();
851         }
852 }
853
854 /** Process callback used when the auditioner is active.
855  * @param nframes number of frames to process.
856  */
857 void
858 Session::process_audition (pframes_t nframes)
859 {
860         SessionEvent* ev;
861         boost::shared_ptr<RouteList> r = routes.reader ();
862
863         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
864                 if (!(*i)->is_auditioner()) {
865                         (*i)->silence (nframes);
866                 }
867         }
868
869         /* run the auditioner, and if it says we need butler service, ask for it */
870
871         if (auditioner->play_audition (nframes) > 0) {
872                 _butler->summon ();
873         }
874
875         /* if using a monitor section, run it because otherwise we don't hear anything */
876
877         if (auditioner->needs_monitor()) {
878                 _monitor_out->monitor_run (_transport_frame, _transport_frame + nframes, nframes, false);
879         }
880
881         /* handle pending events */
882
883         while (pending_events.read (&ev, 1) == 1) {
884                 merge_event (ev);
885         }
886
887         /* if we are not in the middle of a state change,
888            and there are immediate events queued up,
889            process them.
890         */
891
892         while (!non_realtime_work_pending() && !immediate_events.empty()) {
893                 SessionEvent *ev = immediate_events.front ();
894                 immediate_events.pop_front ();
895                 process_event (ev);
896         }
897
898         if (!auditioner->auditioning()) {
899                 /* auditioner no longer active, so go back to the normal process callback */
900                 process_function = &Session::process_with_events;
901         }
902 }
903
904 bool
905 Session::maybe_sync_start (pframes_t & nframes)
906 {
907         pframes_t sync_offset;
908
909         if (!waiting_for_sync_offset) {
910                 return false;
911         }
912
913         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
914
915                 /* generate silence up to the sync point, then
916                    adjust nframes + offset to reflect whatever
917                    is left to do.
918                 */
919
920                 no_roll (sync_offset);
921                 nframes -= sync_offset;
922                 Port::increment_global_port_buffer_offset (sync_offset);
923                 waiting_for_sync_offset = false;
924
925                 if (nframes == 0) {
926                         return true; // done, nothing left to process
927                 }
928
929         } else {
930
931                 /* sync offset point is not within this process()
932                    cycle, so just generate silence. and don't bother
933                    with any fancy stuff here, just the minimal silence.
934                 */
935
936                 _silent = true;
937
938                 if (Config->get_locate_while_waiting_for_sync()) {
939                         if (micro_locate (nframes)) {
940                                 /* XXX ERROR !!! XXX */
941                         }
942                 }
943
944                 return true; // done, nothing left to process
945         }
946
947         return false;
948 }
949
950 void
951 Session::queue_event (SessionEvent* ev)
952 {
953         if (_state_of_the_state & Deletion) {
954                 return;
955         } else if (_state_of_the_state & Loading) {
956                 merge_event (ev);
957         } else {
958                 pending_events.write (&ev, 1);
959         }
960 }
961
962 void
963 Session::set_next_event ()
964 {
965         if (events.empty()) {
966                 next_event = events.end();
967                 return;
968         }
969
970         if (next_event == events.end()) {
971                 next_event = events.begin();
972         }
973
974         if ((*next_event)->action_frame > _transport_frame) {
975                 next_event = events.begin();
976         }
977
978         for (; next_event != events.end(); ++next_event) {
979                 if ((*next_event)->action_frame >= _transport_frame) {
980                         break;
981                 }
982         }
983 }
984
985 void
986 Session::process_event (SessionEvent* ev)
987 {
988         bool remove = true;
989         bool del = true;
990
991         /* if we're in the middle of a state change (i.e. waiting
992            for the butler thread to complete the non-realtime
993            part of the change), we'll just have to queue this
994            event for a time when the change is complete.
995         */
996
997         if (non_realtime_work_pending()) {
998
999                 /* except locates, which we have the capability to handle */
1000
1001                 if (ev->type != SessionEvent::Locate) {
1002                         immediate_events.insert (immediate_events.end(), ev);
1003                         _remove_event (ev);
1004                         return;
1005                 }
1006         }
1007
1008         DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("Processing event: %1 @ %2\n", enum_2_string (ev->type), _transport_frame));
1009
1010         switch (ev->type) {
1011         case SessionEvent::SetLoop:
1012                 set_play_loop (ev->yes_or_no);
1013                 break;
1014
1015         case SessionEvent::AutoLoop:
1016                 if (play_loop) {
1017                         /* roll after locate, do not flush, set "with loop"
1018                            true only if we are seamless looping
1019                         */
1020                         start_locate (ev->target_frame, true, false, Config->get_seamless_loop());
1021                 }
1022                 remove = false;
1023                 del = false;
1024                 break;
1025
1026         case SessionEvent::AutoLoopDeclick:
1027                 if (play_loop) {
1028                         /* Request a declick fade-out and a fade-in; the fade-out will happen
1029                            at the end of the loop, and the fade-in at the start.
1030                         */
1031                         transport_sub_state |= (PendingLoopDeclickOut | PendingLoopDeclickIn);
1032                 }
1033                 remove = false;
1034                 del = false;
1035                 break;
1036
1037         case SessionEvent::Locate:
1038                 if (ev->yes_or_no) {
1039                         /* args: do not roll after locate, do flush, not with loop */
1040                         locate (ev->target_frame, false, true, false);
1041                 } else {
1042                         /* args: do not roll after locate, do flush, not with loop */
1043                         start_locate (ev->target_frame, false, true, false);
1044                 }
1045                 _send_timecode_update = true;
1046                 break;
1047
1048         case SessionEvent::LocateRoll:
1049                 if (ev->yes_or_no) {
1050                         /* args: roll after locate, do flush, not with loop */
1051                         locate (ev->target_frame, true, true, false);
1052                 } else {
1053                         /* args: roll after locate, do flush, not with loop */
1054                         start_locate (ev->target_frame, true, true, false);
1055                 }
1056                 _send_timecode_update = true;
1057                 break;
1058
1059         case SessionEvent::LocateRollLocate:
1060                 // locate is handled by ::request_roll_at_and_return()
1061                 _requested_return_frame = ev->target_frame;
1062                 request_locate (ev->target2_frame, true);
1063                 break;
1064
1065
1066         case SessionEvent::SetTransportSpeed:
1067                 set_transport_speed (ev->speed, ev->yes_or_no, ev->second_yes_or_no, ev->third_yes_or_no);
1068                 break;
1069
1070         case SessionEvent::PunchIn:
1071                 // cerr << "PunchIN at " << transport_frame() << endl;
1072                 if (config.get_punch_in() && record_status() == Enabled) {
1073                         enable_record ();
1074                 }
1075                 remove = false;
1076                 del = false;
1077                 break;
1078
1079         case SessionEvent::PunchOut:
1080                 // cerr << "PunchOUT at " << transport_frame() << endl;
1081                 if (config.get_punch_out()) {
1082                         step_back_from_record ();
1083                 }
1084                 remove = false;
1085                 del = false;
1086                 break;
1087
1088         case SessionEvent::StopOnce:
1089                 if (!non_realtime_work_pending()) {
1090                         stop_transport (ev->yes_or_no);
1091                         _clear_event_type (SessionEvent::StopOnce);
1092                 }
1093                 remove = false;
1094                 del = false;
1095                 break;
1096
1097         case SessionEvent::RangeStop:
1098                 if (!non_realtime_work_pending()) {
1099                         stop_transport (ev->yes_or_no);
1100                 }
1101                 remove = false;
1102                 del = false;
1103                 break;
1104
1105         case SessionEvent::RangeLocate:
1106                 /* args: roll after locate, do flush, not with loop */
1107                 start_locate (ev->target_frame, true, true, false);
1108                 remove = false;
1109                 del = false;
1110                 break;
1111
1112         case SessionEvent::Overwrite:
1113                 overwrite_some_buffers (static_cast<Track*>(ev->ptr));
1114                 break;
1115
1116         case SessionEvent::SetTrackSpeed:
1117                 set_track_speed (static_cast<Track*> (ev->ptr), ev->speed);
1118                 break;
1119
1120         case SessionEvent::SetSyncSource:
1121                 DEBUG_TRACE (DEBUG::Slave, "seen request for new slave\n");
1122                 use_sync_source (ev->slave);
1123                 break;
1124
1125         case SessionEvent::Audition:
1126                 set_audition (ev->region);
1127                 // drop reference to region
1128                 ev->region.reset ();
1129                 break;
1130
1131         case SessionEvent::InputConfigurationChange:
1132                 add_post_transport_work (PostTransportInputChange);
1133                 _butler->schedule_transport_work ();
1134                 break;
1135
1136         case SessionEvent::SetPlayAudioRange:
1137                 set_play_range (ev->audio_range, (ev->speed == 1.0f));
1138                 break;
1139
1140         case SessionEvent::RealTimeOperation:
1141                 process_rtop (ev);
1142                 del = false; // other side of RT request needs to clean up
1143                 break;
1144
1145         case SessionEvent::AdjustPlaybackBuffering:
1146                 schedule_playback_buffering_adjustment ();
1147                 break;
1148
1149         case SessionEvent::AdjustCaptureBuffering:
1150                 schedule_capture_buffering_adjustment ();
1151                 break;
1152
1153         case SessionEvent::SetTimecodeTransmission:
1154                 g_atomic_int_set (&_suspend_timecode_transmission, ev->yes_or_no ? 0 : 1);
1155                 break;
1156
1157         default:
1158           fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
1159                 /*NOTREACHED*/
1160                 break;
1161         };
1162
1163         if (remove) {
1164                 del = del && !_remove_event (ev);
1165         }
1166
1167         if (del) {
1168                 delete ev;
1169         }
1170 }
1171
1172 framepos_t
1173 Session::compute_stop_limit () const
1174 {
1175         if (!Config->get_stop_at_session_end ()) {
1176                 return max_framepos;
1177         }
1178
1179         if (_slave) {
1180                 return max_framepos;
1181         }
1182
1183         
1184         bool const punching_in = (config.get_punch_in () && _locations->auto_punch_location());
1185         bool const punching_out = (config.get_punch_out () && _locations->auto_punch_location());
1186
1187         if (actively_recording ()) {
1188                 /* permanently recording */
1189                 return max_framepos;
1190         } else if (punching_in && !punching_out) {
1191                 /* punching in but never out */
1192                 return max_framepos;
1193         } else if (punching_in && punching_out && _locations->auto_punch_location()->end() > current_end_frame()) {
1194                 /* punching in and punching out after session end */
1195                 return max_framepos;
1196         }
1197
1198         return current_end_frame ();
1199 }