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
  27 #include <glibmm/thread.h>
  28
  29 #include <ardour/ardour.h>
  30 #include <ardour/session.h>
  31 #include <ardour/timestamps.h>
  32 #include <ardour/audio_diskstream.h>
  33 #include <ardour/audioengine.h>
  34 #include <ardour/slave.h>
  35 #include <ardour/auditioner.h>
  36 #include <ardour/cycles.h>
  37 #include <ardour/cycle_timer.h>
  38
  39 #include "i18n.h"
  40
  41 using namespace ARDOUR;
  42 using namespace PBD;
  43 using namespace std;
  44
  45 void
  46 Session::process (nframes_t nframes)
  47 {
  48         if (synced_to_jack() && waiting_to_start) {
  49                 if ( _engine.transport_state() == AudioEngine::TransportRolling) {
  50                         actually_start_transport ();
  51                 }
  52         }
  53
  54         if (non_realtime_work_pending()) {
  55                 if (!transport_work_requested ()) {
  56                         post_transport ();
  57                 }
  58         }
  59
  60         (this->*process_function) (nframes);
  61
  62         SendFeedback (); /* EMIT SIGNAL */
  63 }
  64
  65 void
  66 Session::prepare_diskstreams ()
  67 {
  68         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
  69         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
  70                 (*i)->prepare ();
  71         }
  72 }
  73
  74 int
  75 Session::no_roll (nframes_t nframes, nframes_t offset)
  76 {
  77         nframes_t end_frame = _transport_frame + nframes;
  78         int ret = 0;
  79         bool declick = get_transport_declick_required();
  80         boost::shared_ptr<RouteList> r = routes.reader ();
  81
  82         if (_click_io) {
  83                 _click_io->silence (nframes, offset);
  84         }
  85
  86         if (g_atomic_int_get (&processing_prohibited)) {
  87                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
  88                         (*i)->silence (nframes, offset);
  89                 }
  90                 return 0;
  91         }
  92
  93         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
  94
  95                 if ((*i)->hidden()) {
  96                         continue;
  97                 }
  98
  99                 (*i)->set_pending_declick (declick);
 100
 101                 if ((*i)->no_roll (nframes, _transport_frame, end_frame, offset, non_realtime_work_pending(),
 102                                    actively_recording(), declick)) {
 103                         error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
 104                         ret = -1;
 105                         break;
 106                 }
 107         }
 108
 109         return ret;
 110 }
 111
 112 int
 113 Session::process_routes (nframes_t nframes, nframes_t offset)
 114 {
 115         bool record_active;
 116         int  declick = get_transport_declick_required();
 117         bool rec_monitors = get_rec_monitors_input();
 118         boost::shared_ptr<RouteList> r = routes.reader ();
 119
 120         if (transport_sub_state & StopPendingCapture) {
 121                 /* force a declick out */
 122                 declick = -1;
 123         }
 124
 125         record_active = actively_recording(); // || (get_record_enabled() && get_punch_in());
 126
 127         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 128
 129                 int ret;
 130
 131                 if ((*i)->hidden()) {
 132                         continue;
 133                 }
 134
 135                 (*i)->set_pending_declick (declick);
 136
 137                 if ((ret = (*i)->roll (nframes, _transport_frame, _transport_frame + nframes, offset, declick, record_active, rec_monitors)) < 0) {
 138
 139                         /* we have to do this here. Route::roll() for an AudioTrack will have called AudioDiskstream::process(),
 140                            and the DS will expect AudioDiskstream::commit() to be called. but we're aborting from that
 141                            call path, so make sure we release any outstanding locks here before we return failure.
 142                         */
 143
 144                         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 145                         for (DiskstreamList::iterator ids = dsl->begin(); ids != dsl->end(); ++ids) {
 146                                 (*ids)->recover ();
 147                         }
 148
 149                         stop_transport ();
 150                         return -1;
 151                 }
 152         }
 153
 154         return 0;
 155 }
 156
 157 int
 158 Session::silent_process_routes (nframes_t nframes, nframes_t offset)
 159 {
 160         bool record_active = actively_recording();
 161         int  declick = get_transport_declick_required();
 162         bool rec_monitors = get_rec_monitors_input();
 163         boost::shared_ptr<RouteList> r = routes.reader ();
 164
 165         if (transport_sub_state & StopPendingCapture) {
 166                 /* force a declick out */
 167                 declick = -1;
 168         }
 169
 170         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 171
 172                 int ret;
 173
 174                 if ((*i)->hidden()) {
 175                         continue;
 176                 }
 177
 178                 if ((ret = (*i)->silent_roll (nframes, _transport_frame, _transport_frame + nframes, offset, record_active, rec_monitors)) < 0) {
 179
 180                         /* we have to do this here. Route::roll() for an AudioTrack will have called AudioDiskstream::process(),
 181                            and the DS will expect AudioDiskstream::commit() to be called. but we're aborting from that
 182                            call path, so make sure we release any outstanding locks here before we return failure.
 183                         */
 184
 185                         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 186                         for (DiskstreamList::iterator ids = dsl->begin(); ids != dsl->end(); ++ids) {
 187                                 (*ids)->recover ();
 188                         }
 189
 190                         stop_transport ();
 191                         return -1;
 192                 }
 193         }
 194
 195         return 0;
 196 }
 197
 198 void
 199 Session::commit_diskstreams (nframes_t nframes, bool &needs_butler)
 200 {
 201         int dret;
 202         float pworst = 1.0f;
 203         float cworst = 1.0f;
 204
 205         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 206         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 207
 208                 if ((*i)->hidden()) {
 209                         continue;
 210                 }
 211
 212                 /* force all diskstreams not handled by a Route to call do their stuff.
 213                    Note: the diskstreams that were handled by a route will just return zero
 214                    from this call, because they know they were processed. So in fact, this
 215                    also runs commit() for every diskstream.
 216                  */
 217
 218                 if ((dret = (*i)->process (_transport_frame, nframes, 0, actively_recording(), get_rec_monitors_input())) == 0) {
 219                         if ((*i)->commit (nframes)) {
 220                                 needs_butler = true;
 221                         }
 222
 223                 } else if (dret < 0) {
 224                         (*i)->recover();
 225                 }
 226
 227                 pworst = min (pworst, (*i)->playback_buffer_load());
 228                 cworst = min (cworst, (*i)->capture_buffer_load());
 229         }
 230
 231         uint32_t pmin = g_atomic_int_get (&_playback_load);
 232         uint32_t pminold = g_atomic_int_get (&_playback_load_min);
 233         uint32_t cmin = g_atomic_int_get (&_capture_load);
 234         uint32_t cminold = g_atomic_int_get (&_capture_load_min);
 235
 236         g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 237         g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
 238         g_atomic_int_set (&_playback_load_min, min (pmin, pminold));
 239         g_atomic_int_set (&_capture_load_min, min (cmin, cminold));
 240
 241         if (actively_recording()) {
 242                 set_dirty();
 243         }
 244 }
 245
 246 void
 247 Session::process_with_events (nframes_t nframes)
 248 {
 249         Event* ev;
 250         nframes_t this_nframes;
 251         nframes_t end_frame;
 252         nframes_t offset;
 253         bool session_needs_butler = false;
 254         nframes_t stop_limit;
 255         long           frames_moved;
 256
 257         /* make sure the auditioner is silent */
 258
 259         if (auditioner) {
 260                 auditioner->silence (nframes, 0);
 261         }
 262
 263         /* handle any pending events */
 264
 265         while (pending_events.read (&ev, 1) == 1) {
 266                 merge_event (ev);
 267         }
 268
 269         /* if we are not in the middle of a state change,
 270            and there are immediate events queued up,
 271            process them.
 272         */
 273
 274         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 275                 Event *ev = immediate_events.front ();
 276                 immediate_events.pop_front ();
 277                 process_event (ev);
 278         }
 279
 280         if (!process_can_proceed()) {
 281                 no_roll (nframes, 0);
 282                 return;
 283         }
 284
 285         if (events.empty() || next_event == events.end()) {
 286                 process_without_events (nframes);
 287                 return;
 288         }
 289
 290         end_frame = _transport_frame + (nframes_t)abs(floor(nframes * _transport_speed));
 291
 292         {
 293                 Event* this_event;
 294                 Events::iterator the_next_one;
 295
 296                 if (post_transport_work & (PostTransportLocate|PostTransportStop)) {
 297                         no_roll (nframes, 0);
 298                         return;
 299                 }
 300
 301                 if (!_exporting && _slave) {
 302                         if (!follow_slave (nframes, 0)) {
 303                                 return;
 304                         }
 305                 }
 306
 307                 if (_transport_speed == 0) {
 308                         no_roll (nframes, 0);
 309                         return;
 310                 }
 311
 312                 if (actively_recording()) {
 313                         stop_limit = max_frames;
 314                 } else {
 315
 316                         if (Config->get_stop_at_session_end()) {
 317                                 stop_limit = current_end_frame();
 318                         } else {
 319                                 stop_limit = max_frames;
 320                         }
 321                 }
 322
 323                 if (maybe_stop (stop_limit)) {
 324                         no_roll (nframes, 0);
 325                         return;
 326                 }
 327
 328                 this_event = *next_event;
 329                 the_next_one = next_event;
 330                 ++the_next_one;
 331
 332                 offset = 0;
 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, nframes, offset);
 349
 350                                 /* now process frames between now and the first event in this block */
 351                                 prepare_diskstreams ();
 352
 353                                 if (process_routes (this_nframes, offset)) {
 354                                         no_roll (nframes, 0);
 355                                         return;
 356                                 }
 357
 358                                 commit_diskstreams (this_nframes, session_needs_butler);
 359
 360                                 nframes -= this_nframes;
 361                                 offset += this_nframes;
 362
 363                                 if (frames_moved < 0) {
 364                                         decrement_transport_position (-frames_moved);
 365                                 } else {
 366                                         increment_transport_position (frames_moved);
 367                                 }
 368
 369                                 maybe_stop (stop_limit);
 370                                 check_declick_out ();
 371                         }
 372
 373                         /* now handle this event and all others scheduled for the same time */
 374
 375                         while (this_event && this_event->action_frame == _transport_frame) {
 376                                 process_event (this_event);
 377
 378                                 if (the_next_one == events.end()) {
 379                                         this_event = 0;
 380                                 } else {
 381                                         this_event = *the_next_one;
 382                                         ++the_next_one;
 383                                 }
 384                         }
 385
 386                         /* if an event left our state changing, do the right thing */
 387
 388                         if (non_realtime_work_pending()) {
 389                                 no_roll (nframes, offset);
 390                                 break;
 391                         }
 392
 393                         /* this is necessary to handle the case of seamless looping */
 394                         end_frame = _transport_frame + (nframes_t) floor (nframes * _transport_speed);
 395
 396                 }
 397
 398                 set_next_event ();
 399
 400         } /* implicit release of route lock */
 401
 402
 403         if (session_needs_butler) {
 404                 summon_butler ();
 405         }
 406
 407         if (!_engine.freewheeling() && session_send_mtc) {
 408                 send_midi_time_code_in_another_thread ();
 409         }
 410
 411         return;
 412 }
 413
 414 void
 415 Session::reset_slave_state ()
 416 {
 417         average_slave_delta = 1800;
 418         delta_accumulator_cnt = 0;
 419         have_first_delta_accumulator = false;
 420         slave_state = Stopped;
 421 }
 422
 423 bool
 424 Session::transport_locked () const
 425 {
 426         Slave* sl = _slave;
 427
 428         if (!locate_pending() && ((Config->get_slave_source() == None) || (sl && sl->ok() && sl->locked()))) {
 429                 return true;
 430         }
 431
 432         return false;
 433 }
 434
 435 bool
 436 Session::follow_slave (nframes_t nframes, nframes_t offset)
 437 {
 438         float slave_speed;
 439         nframes_t slave_transport_frame;
 440         nframes_t this_delta;
 441         int dir;
 442         bool starting;
 443
 444         if (!_slave->ok()) {
 445                 stop_transport ();
 446                 Config->set_slave_source (None);
 447                 goto noroll;
 448         }
 449
 450         _slave->speed_and_position (slave_speed, slave_transport_frame);
 451
 452         if (!_slave->locked()) {
 453                 goto noroll;
 454         }
 455
 456         if (slave_transport_frame > _transport_frame) {
 457                 this_delta = slave_transport_frame - _transport_frame;
 458                 dir = 1;
 459         } else {
 460                 this_delta = _transport_frame - slave_transport_frame;
 461                 dir = -1;
 462         }
 463
 464         if ((starting = _slave->starting())) {
 465                 slave_speed = 0.0f;
 466         }
 467
 468 #if 0
 469         cerr << "delta = " << (int) (dir * this_delta)
 470              << " speed = " << slave_speed
 471              << " ts = " << _transport_speed
 472              << " M@"<< slave_transport_frame << " S@" << _transport_frame
 473              << " avgdelta = " << average_slave_delta
 474              << endl;
 475 #endif
 476
 477         if (Config->get_timecode_source_is_synced()) {
 478
 479                 /* if the TC source is synced, then we assume that its
 480                    speed is binary: 0.0 or 1.0
 481                 */
 482
 483                 if (slave_speed != 0.0f) {
 484                         slave_speed = 1.0f;
 485                 }
 486
 487         } else {
 488
 489                 /* TC source is able to drift relative to us (slave)
 490                    so we need to keep track of the drift and adjust
 491                    our speed to remain locked.
 492                 */
 493
 494                 if (delta_accumulator_cnt >= delta_accumulator_size) {
 495                         have_first_delta_accumulator = true;
 496                         delta_accumulator_cnt = 0;
 497                 }
 498
 499                 if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 500                         delta_accumulator[delta_accumulator_cnt++] = dir*this_delta;
 501                 }
 502
 503                 if (have_first_delta_accumulator) {
 504                         average_slave_delta = 0;
 505                         for (int i = 0; i < delta_accumulator_size; ++i) {
 506                                 average_slave_delta += delta_accumulator[i];
 507                         }
 508                         average_slave_delta /= delta_accumulator_size;
 509                         if (average_slave_delta < 0) {
 510                                 average_dir = -1;
 511                                 average_slave_delta = -average_slave_delta;
 512                         } else {
 513                                 average_dir = 1;
 514                         }
 515                         // cerr << "avgdelta = " << average_slave_delta*average_dir << endl;
 516                 }
 517         }
 518
 519         if (slave_speed != 0.0f) {
 520
 521                 /* slave is running */
 522
 523                 switch (slave_state) {
 524                 case Stopped:
 525                         if (_slave->requires_seekahead()) {
 526                                 slave_wait_end = slave_transport_frame + _current_frame_rate;
 527                                 locate (slave_wait_end, false, false);
 528                                 slave_state = Waiting;
 529                                 starting = true;
 530
 531                         } else {
 532
 533                                 slave_state = Running;
 534
 535                                 Location* al = _locations.auto_loop_location();
 536
 537                                 if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 538                                         // cancel looping
 539                                         request_play_loop(false);
 540                                 }
 541
 542                                 if (slave_transport_frame != _transport_frame) {
 543                                         locate (slave_transport_frame, false, false);
 544                                 }
 545                         }
 546                         break;
 547
 548                 case Waiting:
 549                         break;
 550
 551                 default:
 552                         break;
 553
 554                 }
 555
 556                 if (slave_state == Waiting) {
 557
 558                         // cerr << "waiting at " << slave_transport_frame << endl;
 559
 560                         if (slave_transport_frame >= slave_wait_end) {
 561                                 // cerr << "\tstart at " << _transport_frame << endl;
 562
 563                                 slave_state = Running;
 564
 565                                 bool ok = true;
 566                                 nframes_t frame_delta = slave_transport_frame - _transport_frame;
 567
 568                                 boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 569
 570                                 for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 571                                         if (!(*i)->can_internal_playback_seek (frame_delta)) {
 572                                                 ok = false;
 573                                                 break;
 574                                         }
 575                                 }
 576
 577                                 if (ok) {
 578                                         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 579                                                 (*i)->internal_playback_seek (frame_delta);
 580                                         }
 581                                         _transport_frame += frame_delta;
 582
 583                                 } else {
 584                                         // cerr << "cannot micro-seek\n";
 585                                         /* XXX what? */
 586                                 }
 587
 588                                 memset (delta_accumulator, 0, sizeof (nframes_t) * delta_accumulator_size);
 589                                 average_slave_delta = 0;
 590                                 this_delta = 0;
 591                         }
 592                 }
 593
 594                 if (slave_state == Running && _transport_speed == 0.0f) {
 595
 596                         // cerr << "slave starts transport\n";
 597
 598                         start_transport ();
 599                 }
 600
 601         } else {
 602
 603                 /* slave has stopped */
 604
 605                 if (_transport_speed != 0.0f) {
 606
 607                         // cerr << "slave stops transport: " << slave_speed << " frame: " << slave_transport_frame
 608                         // << " tf = " << _transport_frame
 609                         // << endl;
 610
 611                         if (Config->get_slave_source() == JACK) {
 612                                 last_stop_frame = _transport_frame;
 613                         }
 614
 615                         stop_transport();
 616                 }
 617
 618                 if (slave_transport_frame != _transport_frame) {
 619                         // cerr << "slave stopped, move to " << slave_transport_frame << endl;
 620                         force_locate (slave_transport_frame, false);
 621                 }
 622
 623                 slave_state = Stopped;
 624         }
 625
 626         if (slave_state == Running && !Config->get_timecode_source_is_synced()) {
 627
 628
 629                 if (_transport_speed != 0.0f) {
 630
 631                         /*
 632                            note that average_dir is +1 or -1
 633                         */
 634
 635                         const float adjust_seconds = 1.0f;
 636                         float delta;
 637
 638                         //if (average_slave_delta == 0) {
 639                                 delta = this_delta;
 640                                 delta *= dir;
 641 //                      } else {
 642 //                              delta = average_slave_delta;
 643 //                              delta *= average_dir;
 644 //                      }
 645
 646                         float adjusted_speed = slave_speed +
 647                                 (delta / (adjust_seconds * _current_frame_rate));
 648
 649                         // cerr << "adjust using " << delta
 650                         // << " towards " << adjusted_speed
 651                         // << " ratio = " << adjusted_speed / slave_speed
 652                         // << " current = " << _transport_speed
 653                         // << " slave @ " << slave_speed
 654                         // << endl;
 655
 656                         request_transport_speed (adjusted_speed);
 657
 658 #if 1
 659                         if ((nframes_t) average_slave_delta > _slave->resolution()) {
 660                                 // cerr << "not locked\n";
 661                                 goto silent_motion;
 662                         }
 663 #endif
 664                 }
 665         }
 666
 667         if (!starting && !non_realtime_work_pending()) {
 668                 /* speed is set, we're locked, and good to go */
 669                 return true;
 670         }
 671
 672   silent_motion:
 673
 674         if (slave_speed && _transport_speed) {
 675
 676                 /* something isn't right, but we should move with the master
 677                    for now.
 678                 */
 679
 680                 bool need_butler;
 681
 682                 prepare_diskstreams ();
 683                 silent_process_routes (nframes, offset);
 684                 commit_diskstreams (nframes, need_butler);
 685
 686                 if (need_butler) {
 687                         summon_butler ();
 688                 }
 689
 690                 int32_t frames_moved = (int32_t) floor (_transport_speed * nframes);
 691
 692                 if (frames_moved < 0) {
 693                         decrement_transport_position (-frames_moved);
 694                 } else {
 695                         increment_transport_position (frames_moved);
 696                 }
 697
 698                 nframes_t stop_limit;
 699
 700                 if (actively_recording()) {
 701                         stop_limit = max_frames;
 702                 } else {
 703                         if (Config->get_stop_at_session_end()) {
 704                                 stop_limit = current_end_frame();
 705                         } else {
 706                                 stop_limit = max_frames;
 707                         }
 708                 }
 709
 710                 maybe_stop (stop_limit);
 711         }
 712
 713   noroll:
 714         /* don't move at all */
 715         no_roll (nframes, 0);
 716         return false;
 717 }
 718
 719 void
 720 Session::process_without_events (nframes_t nframes)
 721 {
 722         bool session_needs_butler = false;
 723         nframes_t stop_limit;
 724         long frames_moved;
 725         nframes_t offset = 0;
 726
 727         {
 728                 if (post_transport_work & (PostTransportLocate|PostTransportStop)) {
 729                         no_roll (nframes, 0);
 730                         return;
 731                 }
 732
 733                 if (!_exporting && _slave) {
 734                         if (!follow_slave (nframes, 0)) {
 735                                 return;
 736                         }
 737                 }
 738
 739                 if (_transport_speed == 0) {
 740                         no_roll (nframes, 0);
 741                         return;
 742                 }
 743
 744                 if (actively_recording()) {
 745                         stop_limit = max_frames;
 746                 } else {
 747                         if (Config->get_stop_at_session_end()) {
 748                                 stop_limit = current_end_frame();
 749                         } else {
 750                                 stop_limit = max_frames;
 751                         }
 752                 }
 753
 754                 if (maybe_stop (stop_limit)) {
 755                         no_roll (nframes, 0);
 756                         return;
 757                 }
 758
 759                 if (maybe_sync_start (nframes, offset)) {
 760                         return;
 761                 }
 762
 763                 click (_transport_frame, nframes, offset);
 764
 765                 prepare_diskstreams ();
 766
 767                 frames_moved = (long) floor (_transport_speed * nframes);
 768
 769                 if (process_routes (nframes, offset)) {
 770                         no_roll (nframes, offset);
 771                         return;
 772                 }
 773
 774                 commit_diskstreams (nframes, session_needs_butler);
 775
 776                 if (frames_moved < 0) {
 777                         decrement_transport_position (-frames_moved);
 778                 } else {
 779                         increment_transport_position (frames_moved);
 780                 }
 781
 782                 maybe_stop (stop_limit);
 783                 check_declick_out ();
 784
 785         } /* implicit release of route lock */
 786
 787         if (session_needs_butler) {
 788                 summon_butler ();
 789         }
 790
 791         if (!_engine.freewheeling() && session_send_mtc) {
 792                 send_midi_time_code_in_another_thread ();
 793         }
 794
 795         return;
 796 }
 797
 798 void
 799 Session::process_audition (nframes_t nframes)
 800 {
 801         Event* ev;
 802         boost::shared_ptr<RouteList> r = routes.reader ();
 803
 804         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 805                 if (!(*i)->hidden()) {
 806                         (*i)->silence (nframes, 0);
 807                 }
 808         }
 809
 810         /* run the auditioner, and if it says we need butler service, ask for it */
 811
 812         if (auditioner->play_audition (nframes) > 0) {
 813                 summon_butler ();
 814         }
 815
 816         /* handle pending events */
 817
 818         while (pending_events.read (&ev, 1) == 1) {
 819                 merge_event (ev);
 820         }
 821
 822         /* if we are not in the middle of a state change,
 823            and there are immediate events queued up,
 824            process them.
 825         */
 826
 827         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 828                 Event *ev = immediate_events.front ();
 829                 immediate_events.pop_front ();
 830                 process_event (ev);
 831         }
 832
 833         if (!auditioner->active()) {
 834                 process_function = &Session::process_with_events;
 835         }
 836 }
 837
 838 bool
 839 Session::maybe_sync_start (nframes_t& nframes, nframes_t& offset)
 840 {
 841         nframes_t sync_offset;
 842
 843         if (!waiting_for_sync_offset) {
 844                 return false;
 845         }
 846
 847         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
 848
 849                 no_roll (sync_offset, 0);
 850                 nframes -= sync_offset;
 851                 offset += sync_offset;
 852                 waiting_for_sync_offset = false;
 853
 854                 if (nframes == 0) {
 855                         return true; // done
 856                 }
 857
 858         } else {
 859                 no_roll (nframes, 0);
 860                 return true; // done
 861         }
 862
 863         return false;
 864 }
 865