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/thread.h>
  29
  30 #include "ardour/ardour.h"
  31 #include "ardour/audioengine.h"
  32 #include "ardour/auditioner.h"
  33 #include "ardour/butler.h"
  34 #include "ardour/debug.h"
  35 #include "ardour/process_thread.h"
  36 #include "ardour/session.h"
  37 #include "ardour/slave.h"
  38 #include "ardour/timestamps.h"
  39 #include "ardour/port.h"
  40
  41 #include "midi++/manager.h"
  42
  43 #include "i18n.h"
  44
  45 using namespace ARDOUR;
  46 using namespace PBD;
  47 using namespace std;
  48
  49 /** Called by the audio engine when there is work to be done with JACK.
  50  * @param nframes Number of frames to process.
  51  */
  52 void
  53 Session::process (nframes_t nframes)
  54 {
  55         MIDI::Manager::instance()->cycle_start(nframes);
  56
  57         _silent = false;
  58
  59         if (processing_blocked()) {
  60                 _silent = true;
  61                 return;
  62         }
  63
  64         if (non_realtime_work_pending()) {
  65                 if (!_butler->transport_work_requested ()) {
  66                         post_transport ();
  67                 }
  68         }
  69
  70         _engine.main_thread()->get_buffers ();
  71
  72         (this->*process_function) (nframes);
  73
  74         _engine.main_thread()->drop_buffers ();
  75
  76         // the ticker is for sending time information like MidiClock
  77         nframes_t transport_frames = transport_frame();
  78         BBT_Time  transport_bbt;
  79         bbt_time(transport_frames, transport_bbt);
  80         Timecode::Time transport_timecode;
  81         timecode_time(transport_frames, transport_timecode);
  82         tick (transport_frames, transport_bbt, transport_timecode); /* EMIT SIGNAL */
  83
  84         SendFeedback (); /* EMIT SIGNAL */
  85
  86         MIDI::Manager::instance()->cycle_end();
  87 }
  88
  89 int
  90 Session::fail_roll (nframes_t nframes)
  91 {
  92         return no_roll (nframes);
  93 }
  94
  95 int
  96 Session::no_roll (nframes_t nframes)
  97 {
  98         nframes_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
  99         int ret = 0;
 100         bool declick = get_transport_declick_required();
 101         boost::shared_ptr<RouteList> r = routes.reader ();
 102
 103         if (_click_io) {
 104                 _click_io->silence (nframes);
 105         }
 106
 107         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 108
 109                 if ((*i)->is_hidden()) {
 110                         continue;
 111                 }
 112
 113                 (*i)->set_pending_declick (declick);
 114
 115                 if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending(),
 116                                    actively_recording(), declick)) {
 117                         error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
 118                         ret = -1;
 119                         break;
 120                 }
 121         }
 122
 123         return ret;
 124 }
 125
 126 int
 127 Session::process_routes (nframes_t nframes, bool& need_butler)
 128 {
 129         bool record_active;
 130         int  declick = get_transport_declick_required();
 131         bool rec_monitors = get_rec_monitors_input();
 132         boost::shared_ptr<RouteList> r = routes.reader ();
 133
 134         if (transport_sub_state & StopPendingCapture) {
 135                 /* force a declick out */
 136                 declick = -1;
 137         }
 138
 139         record_active = actively_recording(); // || (get_record_enabled() && get_punch_in());
 140
 141         const nframes_t start_frame = _transport_frame;
 142         const nframes_t end_frame = _transport_frame + (nframes_t)floor(nframes * _transport_speed);
 143
 144         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 145
 146                 int ret;
 147
 148                 if ((*i)->is_hidden()) {
 149                         continue;
 150                 }
 151
 152                 (*i)->set_pending_declick (declick);
 153
 154                 if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, record_active, rec_monitors, need_butler)) < 0) {
 155                         stop_transport ();
 156                         return -1;
 157                 }
 158         }
 159
 160         return 0;
 161 }
 162
 163 int
 164 Session::silent_process_routes (nframes_t nframes, bool& need_butler)
 165 {
 166         bool record_active = actively_recording();
 167         int  declick = get_transport_declick_required();
 168         bool rec_monitors = get_rec_monitors_input();
 169         boost::shared_ptr<RouteList> r = routes.reader ();
 170
 171         if (transport_sub_state & StopPendingCapture) {
 172                 /* force a declick out */
 173                 declick = -1;
 174         }
 175
 176         const nframes_t start_frame = _transport_frame;
 177         const nframes_t end_frame = _transport_frame + lrintf(nframes * _transport_speed);
 178
 179         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 180
 181                 int ret;
 182
 183                 if ((*i)->is_hidden()) {
 184                         continue;
 185                 }
 186
 187                 if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, record_active, rec_monitors, need_butler)) < 0) {
 188                         stop_transport ();
 189                         return -1;
 190                 }
 191         }
 192
 193         return 0;
 194 }
 195
 196 void
 197 Session::get_track_statistics ()
 198 {
 199         float pworst = 1.0f;
 200         float cworst = 1.0f;
 201
 202         boost::shared_ptr<RouteList> rl = routes.reader();
 203         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 204
 205                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 206
 207                 if (!tr || tr->hidden()) {
 208                         continue;
 209                 }
 210
 211                 pworst = min (pworst, tr->playback_buffer_load());
 212                 cworst = min (cworst, tr->capture_buffer_load());
 213         }
 214
 215         g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 216         g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
 217
 218         if (actively_recording()) {
 219                 set_dirty();
 220         }
 221 }
 222
 223 /** Process callback used when the auditioner is not active */
 224 void
 225 Session::process_with_events (nframes_t nframes)
 226 {
 227         SessionEvent*         ev;
 228         nframes_t      this_nframes;
 229         nframes_t      end_frame;
 230         bool           session_needs_butler = false;
 231         nframes_t      stop_limit;
 232         long           frames_moved;
 233
 234         /* make sure the auditioner is silent */
 235
 236         if (auditioner) {
 237                 auditioner->silence (nframes);
 238         }
 239
 240         /* handle any pending events */
 241
 242         while (pending_events.read (&ev, 1) == 1) {
 243                 merge_event (ev);
 244         }
 245
 246         /* if we are not in the middle of a state change,
 247            and there are immediate events queued up,
 248            process them.
 249         */
 250
 251         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 252                 SessionEvent *ev = immediate_events.front ();
 253                 immediate_events.pop_front ();
 254                 process_event (ev);
 255         }
 256
 257         /* Events caused a transport change, send an MTC Full Frame (Timecode) message.
 258          * This is sent whether rolling or not, to give slaves an idea of ardour time
 259          * on locates (and allow slow slaves to position and prepare for rolling)
 260          */
 261         if (_send_timecode_update) {
 262                 send_full_time_code(nframes);
 263                 deliver_mmc (MIDI::MachineControl::cmdLocate, _transport_frame);
 264         }
 265
 266         if (!process_can_proceed()) {
 267                 _silent = true;
 268                 return;
 269         }
 270
 271         if (events.empty() || next_event == events.end()) {
 272                 process_without_events (nframes);
 273                 return;
 274         }
 275
 276         if (_transport_speed == 1.0) {
 277                 frames_moved = (long) nframes;
 278         } else {
 279                 interpolation.set_target_speed (fabs(_target_transport_speed));
 280                 interpolation.set_speed (fabs(_transport_speed));
 281                 frames_moved = (long) interpolation.interpolate (0, nframes, 0, 0);
 282         }
 283
 284         end_frame = _transport_frame + (nframes_t)frames_moved;
 285
 286         {
 287                 SessionEvent* this_event;
 288                 Events::iterator the_next_one;
 289
 290                 if (!process_can_proceed()) {
 291                         _silent = true;
 292                         return;
 293                 }
 294
 295                 if (!_exporting && _slave) {
 296                         if (!follow_slave (nframes)) {
 297                                 return;
 298                         }
 299                 }
 300
 301                 if (_transport_speed == 0) {
 302                         no_roll (nframes);
 303                         return;
 304                 }
 305
 306                 if (!_exporting) {
 307                         send_midi_time_code_for_cycle (nframes);
 308                 }
 309
 310                 if (actively_recording()) {
 311                         stop_limit = max_frames;
 312                 } else {
 313
 314                         if (Config->get_stop_at_session_end()) {
 315                                 stop_limit = current_end_frame();
 316                         } else {
 317                                 stop_limit = max_frames;
 318                         }
 319                 }
 320
 321                 if (maybe_stop (stop_limit)) {
 322                         no_roll (nframes);
 323                         return;
 324                 }
 325
 326                 this_event = *next_event;
 327                 the_next_one = next_event;
 328                 ++the_next_one;
 329
 330                 /* yes folks, here it is, the actual loop where we really truly
 331                    process some audio
 332                 */
 333
 334                 while (nframes) {
 335
 336                         this_nframes = nframes; /* real (jack) time relative */
 337                         frames_moved = (long) floor (_transport_speed * nframes); /* transport relative */
 338
 339                         /* running an event, position transport precisely to its time */
 340                         if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
 341                                 /* this isn't quite right for reverse play */
 342                                 frames_moved = (long) (this_event->action_frame - _transport_frame);
 343                                 this_nframes = (nframes_t) abs( floor(frames_moved / _transport_speed) );
 344                         }
 345
 346                         if (this_nframes) {
 347
 348                                 click (_transport_frame, this_nframes);
 349
 350                                 if (process_routes (this_nframes, session_needs_butler)) {
 351                                         fail_roll (nframes);
 352                                         return;
 353                                 }
 354
 355                                 get_track_statistics ();
 356
 357                                 nframes -= this_nframes;
 358
 359                                 if (frames_moved < 0) {
 360                                         decrement_transport_position (-frames_moved);
 361                                 } else {
 362                                         increment_transport_position (frames_moved);
 363                                 }
 364
 365                                 maybe_stop (stop_limit);
 366                                 check_declick_out ();
 367                         }
 368
 369                         _engine.split_cycle (this_nframes);
 370
 371                         /* now handle this event and all others scheduled for the same time */
 372
 373                         while (this_event && this_event->action_frame == _transport_frame) {
 374                                 process_event (this_event);
 375
 376                                 if (the_next_one == events.end()) {
 377                                         this_event = 0;
 378                                 } else {
 379                                         this_event = *the_next_one;
 380                                         ++the_next_one;
 381                                 }
 382                         }
 383
 384                         /* if an event left our state changing, do the right thing */
 385
 386                         if (nframes && non_realtime_work_pending()) {
 387                                 no_roll (nframes);
 388                                 break;
 389                         }
 390
 391                         /* this is necessary to handle the case of seamless looping */
 392                         end_frame = _transport_frame + (nframes_t) floor (nframes * _transport_speed);
 393
 394                 }
 395
 396                 set_next_event ();
 397
 398         } /* implicit release of route lock */
 399
 400         if (session_needs_butler) {
 401                 _butler->summon ();
 402         }
 403 }
 404
 405 void
 406 Session::reset_slave_state ()
 407 {
 408         average_slave_delta = 1800;
 409         delta_accumulator_cnt = 0;
 410         have_first_delta_accumulator = false;
 411         _slave_state = Stopped;
 412 }
 413
 414 bool
 415 Session::transport_locked () const
 416 {
 417         Slave* sl = _slave;
 418
 419         if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
 420                 return true;
 421         }
 422
 423         return false;
 424 }
 425
 426 bool
 427 Session::follow_slave (nframes_t nframes)
 428 {
 429         double slave_speed;
 430         nframes64_t slave_transport_frame;
 431         nframes_t this_delta;
 432         int dir;
 433
 434         if (!_slave->ok()) {
 435                 stop_transport ();
 436                 config.set_external_sync (false);
 437                 goto noroll;
 438         }
 439
 440         _slave->speed_and_position (slave_speed, slave_transport_frame);
 441
 442         DEBUG_TRACE (DEBUG::Slave, string_compose ("Slave position %1 speed %2\n", slave_transport_frame, slave_speed));
 443
 444         if (!_slave->locked()) {
 445                 DEBUG_TRACE (DEBUG::Slave, "slave not locked\n");
 446                 goto noroll;
 447         }
 448
 449         if (slave_transport_frame > _transport_frame) {
 450                 this_delta = slave_transport_frame - _transport_frame;
 451                 dir = 1;
 452         } else {
 453                 this_delta = _transport_frame - slave_transport_frame;
 454                 dir = -1;
 455         }
 456
 457         if (_slave->starting()) {
 458                 slave_speed = 0.0f;
 459         }
 460
 461         if (_slave->is_always_synced() || config.get_timecode_source_is_synced()) {
 462
 463                 /* if the TC source is synced, then we assume that its
 464                    speed is binary: 0.0 or 1.0
 465                 */
 466
 467                 if (slave_speed != 0.0f) {
 468                         slave_speed = 1.0f;
 469                 }
 470
 471         } else {
 472
 473                 /* if we are chasing and the average delta between us and the
 474                    master gets too big, we want to switch to silent
 475                    motion. so keep track of that here.
 476                 */
 477
 478                 if (_slave_state == Running) {
 479                         calculate_moving_average_of_slave_delta(dir, this_delta);
 480                 }
 481         }
 482
 483         track_slave_state (slave_speed, slave_transport_frame, this_delta);
 484
 485         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
 486                                                    _slave_state, slave_transport_frame, slave_speed, this_delta, average_slave_delta));
 487
 488
 489         if (_slave_state == Running && !_slave->is_always_synced() && !config.get_timecode_source_is_synced()) {
 490
 491                 if (_transport_speed != 0.0f) {
 492
 493                         /*
 494                            note that average_dir is +1 or -1
 495                         */
 496
 497                         float delta;
 498
 499                         if (average_slave_delta == 0) {
 500                                 delta = this_delta;
 501                                 delta *= dir;
 502                         } else {
 503                                 delta = average_slave_delta;
 504                                 delta *= average_dir;
 505                         }
 506
 507 #ifndef NDEBUG
 508                         if (slave_speed != 0.0) {
 509                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("delta = %1 speed = %2 ts = %3 M@%4 S@%5 avgdelta %6\n",
 510                                                                            (int) (dir * this_delta),
 511                                                                            slave_speed,
 512                                                                            _transport_speed,
 513                                                                            _transport_frame,
 514                                                                            slave_transport_frame,
 515                                                                            average_slave_delta));
 516                         }
 517 #endif
 518
 519                         if (_slave->give_slave_full_control_over_transport_speed()) {
 520                                 set_transport_speed (slave_speed, false, false);
 521                                 //std::cout << "set speed = " << slave_speed << "\n";
 522                         } else {
 523                                 float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_frame_rate)));
 524                                 request_transport_speed (adjusted_speed);
 525                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("adjust using %1 towards %2 ratio %3 current %4 slave @ %5\n",
 526                                                                            delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
 527                                                                            slave_speed));
 528                         }
 529
 530 #if 1
 531                         if ((nframes_t) abs(average_slave_delta) > _slave->resolution()) {
 532                                 cerr << "average slave delta greater than slave resolution (" << _slave->resolution() << "), going to silent motion\n";
 533                                 goto silent_motion;
 534                         }
 535 #endif
 536                 }
 537         }
 538
 539
 540         if (_slave_state == Running && !non_realtime_work_pending()) {
 541                 /* speed is set, we're locked, and good to go */
 542                 return true;
 543         }
 544
 545   silent_motion:
 546         DEBUG_TRACE (DEBUG::Slave, "silent motion\n")
 547         follow_slave_silently (nframes, slave_speed);
 548
 549   noroll:
 550         /* don't move at all */
 551         DEBUG_TRACE (DEBUG::Slave, "no roll\n")
 552         no_roll (nframes);
 553         return false;
 554 }
 555
 556 void
 557 Session::calculate_moving_average_of_slave_delta(int dir, nframes_t this_delta)
 558 {
 559         if (delta_accumulator_cnt >= delta_accumulator_size) {
 560                 have_first_delta_accumulator = true;
 561                 delta_accumulator_cnt = 0;
 562         }
 563
 564         if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 565                 delta_accumulator[delta_accumulator_cnt++] = long(dir) * long(this_delta);
 566         }
 567
 568         if (have_first_delta_accumulator) {
 569                 average_slave_delta = 0L;
 570                 for (int i = 0; i < delta_accumulator_size; ++i) {
 571                         average_slave_delta += delta_accumulator[i];
 572                 }
 573                 average_slave_delta /= long(delta_accumulator_size);
 574                 if (average_slave_delta < 0L) {
 575                         average_dir = -1;
 576                         average_slave_delta = abs(average_slave_delta);
 577                 } else {
 578                         average_dir = 1;
 579                 }
 580         }
 581 }
 582
 583 void
 584 Session::track_slave_state (float slave_speed, nframes_t slave_transport_frame, nframes_t this_delta)
 585 {
 586         if (slave_speed != 0.0f) {
 587
 588                 /* slave is running */
 589
 590                 switch (_slave_state) {
 591                 case Stopped:
 592                         if (_slave->requires_seekahead()) {
 593                                 slave_wait_end = slave_transport_frame + _slave->seekahead_distance ();
 594                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, but running, requires seekahead to %1\n", slave_wait_end));
 595                                 /* we can call locate() here because we are in process context */
 596                                 locate (slave_wait_end, false, false);
 597                                 _slave_state = Waiting;
 598
 599                         } else {
 600
 601                                 _slave_state = Running;
 602
 603                                 Location* al = _locations.auto_loop_location();
 604
 605                                 if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 606                                         // cancel looping
 607                                         request_play_loop(false);
 608                                 }
 609
 610                                 if (slave_transport_frame != _transport_frame) {
 611                                         locate (slave_transport_frame, false, false);
 612                                 }
 613                         }
 614                         break;
 615
 616                 case Waiting:
 617                 default:
 618                         break;
 619                 }
 620
 621                 if (_slave_state == Waiting) {
 622
 623                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave waiting at %1\n", slave_transport_frame));
 624
 625                         if (slave_transport_frame >= slave_wait_end) {
 626
 627                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave start at %1 vs %2\n", slave_transport_frame, _transport_frame));
 628
 629                                 _slave_state = Running;
 630
 631                                 /* now perform a "micro-seek" within the disk buffers to realign ourselves
 632                                    precisely with the master.
 633                                 */
 634
 635
 636                                 bool ok = true;
 637                                 nframes_t frame_delta = slave_transport_frame - _transport_frame;
 638
 639                                 boost::shared_ptr<RouteList> rl = routes.reader();
 640                                 for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 641                                         boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 642                                         if (tr && !tr->can_internal_playback_seek (frame_delta)) {
 643                                                 ok = false;
 644                                                 break;
 645                                         }
 646                                 }
 647
 648                                 if (ok) {
 649                                         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 650                                                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 651                                                 if (tr) {
 652                                                         tr->internal_playback_seek (frame_delta);
 653                                                 }
 654                                         }
 655                                         _transport_frame += frame_delta;
 656
 657                                 } else {
 658                                         cerr << "cannot micro-seek\n";
 659                                         /* XXX what? */
 660                                 }
 661
 662                                 memset (delta_accumulator, 0, sizeof (long) * delta_accumulator_size);
 663                                 average_slave_delta = 0L;
 664                                 this_delta = 0;
 665                         }
 666                 }
 667
 668                 if (_slave_state == Running && _transport_speed == 0.0f) {
 669                         DEBUG_TRACE (DEBUG::Slave, "slave starts transport\n");
 670                         start_transport ();
 671                 }
 672
 673         } else { // slave_speed is 0
 674
 675                 /* slave has stopped */
 676
 677                 if (_transport_speed != 0.0f) {
 678                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 frame %2 tf %3\n", slave_speed, slave_transport_frame, _transport_frame));
 679                         stop_transport();
 680                 }
 681
 682                 if (slave_transport_frame != _transport_frame) {
 683                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, move to %1\n", slave_transport_frame));
 684                         force_locate (slave_transport_frame, false);
 685                 }
 686
 687                 _slave_state = Stopped;
 688         }
 689 }
 690
 691 void
 692 Session::follow_slave_silently (nframes_t nframes, float slave_speed)
 693 {
 694         if (slave_speed && _transport_speed) {
 695
 696                 /* something isn't right, but we should move with the master
 697                    for now.
 698                 */
 699
 700                 bool need_butler;
 701
 702                 silent_process_routes (nframes, need_butler);
 703
 704                 get_track_statistics ();
 705
 706                 if (need_butler) {
 707                         _butler->summon ();
 708                 }
 709
 710                 int32_t frames_moved = (int32_t) floor (_transport_speed * nframes);
 711
 712                 if (frames_moved < 0) {
 713                         decrement_transport_position (-frames_moved);
 714                 } else {
 715                         increment_transport_position (frames_moved);
 716                 }
 717
 718                 nframes_t stop_limit;
 719
 720                 if (actively_recording()) {
 721                         stop_limit = max_frames;
 722                 } else {
 723                         if (Config->get_stop_at_session_end()) {
 724                                 stop_limit = current_end_frame();
 725                         } else {
 726                                 stop_limit = max_frames;
 727                         }
 728                 }
 729
 730                 maybe_stop (stop_limit);
 731         }
 732 }
 733
 734 void
 735 Session::process_without_events (nframes_t nframes)
 736 {
 737         bool session_needs_butler = false;
 738         nframes_t stop_limit;
 739         long frames_moved;
 740
 741         if (!process_can_proceed()) {
 742                 _silent = true;
 743                 return;
 744         }
 745
 746         if (!_exporting && _slave) {
 747                 if (!follow_slave (nframes)) {
 748                         return;
 749                 }
 750         }
 751
 752         if (_transport_speed == 0) {
 753                 fail_roll (nframes);
 754                 return;
 755         }
 756
 757         if (!_exporting) {
 758                 send_midi_time_code_for_cycle (nframes);
 759         }
 760
 761         if (actively_recording()) {
 762                 stop_limit = max_frames;
 763         } else {
 764                 if (Config->get_stop_at_session_end()) {
 765                         stop_limit = current_end_frame();
 766                 } else {
 767                         stop_limit = max_frames;
 768                 }
 769         }
 770
 771         if (maybe_stop (stop_limit)) {
 772                 fail_roll (nframes);
 773                 return;
 774         }
 775
 776         if (maybe_sync_start (nframes)) {
 777                 return;
 778         }
 779
 780         click (_transport_frame, nframes);
 781
 782         if (_transport_speed == 1.0) {
 783                 frames_moved = (long) nframes;
 784         } else {
 785                 interpolation.set_target_speed (fabs(_target_transport_speed));
 786                 interpolation.set_speed (fabs(_transport_speed));
 787                 frames_moved = (long) interpolation.interpolate (0, nframes, 0, 0);
 788         }
 789
 790         if (process_routes (nframes, session_needs_butler)) {
 791                 fail_roll (nframes);
 792                 return;
 793         }
 794
 795         get_track_statistics ();
 796
 797         if (frames_moved < 0) {
 798                 decrement_transport_position (-frames_moved);
 799         } else {
 800                 increment_transport_position (frames_moved);
 801         }
 802
 803         maybe_stop (stop_limit);
 804         check_declick_out ();
 805
 806         if (session_needs_butler) {
 807                 _butler->summon ();
 808         }
 809 }
 810
 811 /** Process callback used when the auditioner is active.
 812  * @param nframes number of frames to process.
 813  */
 814 void
 815 Session::process_audition (nframes_t nframes)
 816 {
 817         SessionEvent* ev;
 818         boost::shared_ptr<RouteList> r = routes.reader ();
 819
 820         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 821                 if (!(*i)->is_hidden()) {
 822                         (*i)->silence (nframes);
 823                 }
 824         }
 825
 826         /* run the auditioner, and if it says we need butler service, ask for it */
 827
 828         if (auditioner->play_audition (nframes) > 0) {
 829                 _butler->summon ();
 830         }
 831
 832         /* if using a monitor section, run it because otherwise we don't hear anything */
 833
 834         if (auditioner->needs_monitor()) {
 835                 _monitor_out->passthru (_transport_frame, _transport_frame + nframes, nframes, false);
 836         }
 837
 838         /* handle pending events */
 839
 840         while (pending_events.read (&ev, 1) == 1) {
 841                 merge_event (ev);
 842         }
 843
 844         /* if we are not in the middle of a state change,
 845            and there are immediate events queued up,
 846            process them.
 847         */
 848
 849         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 850                 SessionEvent *ev = immediate_events.front ();
 851                 immediate_events.pop_front ();
 852                 process_event (ev);
 853         }
 854
 855         if (!auditioner->auditioning()) {
 856                 /* auditioner no longer active, so go back to the normal process callback */
 857                 process_function = &Session::process_with_events;
 858         }
 859 }
 860
 861 bool
 862 Session::maybe_sync_start (nframes_t& nframes)
 863 {
 864         nframes_t sync_offset;
 865
 866         if (!waiting_for_sync_offset) {
 867                 return false;
 868         }
 869
 870         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
 871
 872                 /* generate silence up to the sync point, then
 873                    adjust nframes + offset to reflect whatever
 874                    is left to do.
 875                 */
 876
 877                 no_roll (sync_offset);
 878                 nframes -= sync_offset;
 879                 Port::increment_port_offset (sync_offset);
 880                 waiting_for_sync_offset = false;
 881
 882                 if (nframes == 0) {
 883                         return true; // done, nothing left to process
 884                 }
 885
 886         } else {
 887
 888                 /* sync offset point is not within this process()
 889                    cycle, so just generate silence. and don't bother
 890                    with any fancy stuff here, just the minimal silence.
 891                 */
 892
 893                 _silent = true;
 894
 895                 if (Config->get_locate_while_waiting_for_sync()) {
 896                         if (micro_locate (nframes)) {
 897                                 /* XXX ERROR !!! XXX */
 898                         }
 899                 }
 900
 901                 return true; // done, nothing left to process
 902         }
 903
 904         return false;
 905 }
 906
 907 void
 908 Session::queue_event (SessionEvent* ev)
 909 {
 910         if (_state_of_the_state & Deletion) {
 911                 return;
 912         } else if (_state_of_the_state & Loading) {
 913                 merge_event (ev);
 914         } else {
 915                 pending_events.write (&ev, 1);
 916         }
 917 }
 918
 919 void
 920 Session::set_next_event ()
 921 {
 922         if (events.empty()) {
 923                 next_event = events.end();
 924                 return;
 925         }
 926
 927         if (next_event == events.end()) {
 928                 next_event = events.begin();
 929         }
 930
 931         if ((*next_event)->action_frame > _transport_frame) {
 932                 next_event = events.begin();
 933         }
 934
 935         for (; next_event != events.end(); ++next_event) {
 936                 if ((*next_event)->action_frame >= _transport_frame) {
 937                         break;
 938                 }
 939         }
 940 }
 941
 942 void
 943 Session::process_event (SessionEvent* ev)
 944 {
 945         bool remove = true;
 946         bool del = true;
 947
 948         /* if we're in the middle of a state change (i.e. waiting
 949            for the butler thread to complete the non-realtime
 950            part of the change), we'll just have to queue this
 951            event for a time when the change is complete.
 952         */
 953
 954         if (non_realtime_work_pending()) {
 955
 956                 /* except locates, which we have the capability to handle */
 957
 958                 if (ev->type != SessionEvent::Locate) {
 959                         immediate_events.insert (immediate_events.end(), ev);
 960                         _remove_event (ev);
 961                         return;
 962                 }
 963         }
 964
 965         DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("Processing event: %1 @ %2\n", enum_2_string (ev->type), _transport_frame));
 966
 967         switch (ev->type) {
 968         case SessionEvent::SetLoop:
 969                 set_play_loop (ev->yes_or_no);
 970                 break;
 971
 972         case SessionEvent::AutoLoop:
 973                 if (play_loop) {
 974                         start_locate (ev->target_frame, true, false, Config->get_seamless_loop());
 975                 }
 976                 remove = false;
 977                 del = false;
 978                 break;
 979
 980         case SessionEvent::Locate:
 981                 if (ev->yes_or_no) {
 982                         // cerr << "forced locate to " << ev->target_frame << endl;
 983                         locate (ev->target_frame, false, true, false);
 984                 } else {
 985                         // cerr << "soft locate to " << ev->target_frame << endl;
 986                         start_locate (ev->target_frame, false, true, false);
 987                 }
 988                 _send_timecode_update = true;
 989                 break;
 990
 991         case SessionEvent::LocateRoll:
 992                 if (ev->yes_or_no) {
 993                         // cerr << "forced locate to+roll " << ev->target_frame << endl;
 994                         locate (ev->target_frame, true, true, false);
 995                 } else {
 996                         // cerr << "soft locate to+roll " << ev->target_frame << endl;
 997                         start_locate (ev->target_frame, true, true, false);
 998                 }
 999                 _send_timecode_update = true;
1000                 break;
1001
1002         case SessionEvent::LocateRollLocate:
1003                 // locate is handled by ::request_roll_at_and_return()
1004                 _requested_return_frame = ev->target_frame;
1005                 request_locate (ev->target2_frame, true);
1006                 break;
1007
1008
1009         case SessionEvent::SetTransportSpeed:
1010                 set_transport_speed (ev->speed, ev->yes_or_no, ev->second_yes_or_no);
1011                 break;
1012
1013         case SessionEvent::PunchIn:
1014                 // cerr << "PunchIN at " << transport_frame() << endl;
1015                 if (config.get_punch_in() && record_status() == Enabled) {
1016                         enable_record ();
1017                 }
1018                 remove = false;
1019                 del = false;
1020                 break;
1021
1022         case SessionEvent::PunchOut:
1023                 // cerr << "PunchOUT at " << transport_frame() << endl;
1024                 if (config.get_punch_out()) {
1025                         step_back_from_record ();
1026                 }
1027                 remove = false;
1028                 del = false;
1029                 break;
1030
1031         case SessionEvent::StopOnce:
1032                 if (!non_realtime_work_pending()) {
1033                         stop_transport (ev->yes_or_no);
1034                         _clear_event_type (SessionEvent::StopOnce);
1035                 }
1036                 remove = false;
1037                 del = false;
1038                 break;
1039
1040         case SessionEvent::RangeStop:
1041                 if (!non_realtime_work_pending()) {
1042                         stop_transport (ev->yes_or_no);
1043                 }
1044                 remove = false;
1045                 del = false;
1046                 break;
1047
1048         case SessionEvent::RangeLocate:
1049                 start_locate (ev->target_frame, true, true, false);
1050                 remove = false;
1051                 del = false;
1052                 break;
1053
1054         case SessionEvent::Overwrite:
1055                 overwrite_some_buffers (static_cast<Track*>(ev->ptr));
1056                 break;
1057
1058         case SessionEvent::SetTrackSpeed:
1059                 set_track_speed (static_cast<Track*> (ev->ptr), ev->speed);
1060                 break;
1061
1062         case SessionEvent::SetSyncSource:
1063                 use_sync_source (ev->slave);
1064                 break;
1065
1066         case SessionEvent::Audition:
1067                 set_audition (ev->region);
1068                 // drop reference to region
1069                 ev->region.reset ();
1070                 break;
1071
1072         case SessionEvent::InputConfigurationChange:
1073                 add_post_transport_work (PostTransportInputChange);
1074                 _butler->schedule_transport_work ();
1075                 break;
1076
1077         case SessionEvent::SetPlayAudioRange:
1078                 set_play_range (ev->audio_range, (ev->speed == 1.0f));
1079                 break;
1080
1081         case SessionEvent::RealTimeOperation:
1082                 process_rtop (ev);
1083                 del = false; // other side of RT request needs to clean up
1084                 break;
1085
1086         default:
1087           fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
1088                 /*NOTREACHED*/
1089                 break;
1090         };
1091
1092         if (remove) {
1093                 del = del && !_remove_event (ev);
1094         }
1095
1096         if (del) {
1097                 delete ev;
1098         }
1099 }
1100