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         _silent = false;
  49
  50         if (processing_blocked()) {
  51                 _silent = true;
  52                 return;
  53         }
  54
  55         if (non_realtime_work_pending()) {
  56                 if (!transport_work_requested ()) {
  57                         post_transport ();
  58                 }
  59         }
  60
  61         (this->*process_function) (nframes);
  62
  63         {
  64                 Glib::Mutex::Lock lm (midi_lock, Glib::TRY_LOCK);
  65                 SendFeedback (); /* EMIT SIGNAL */
  66         }
  67 }
  68
  69 void
  70 Session::prepare_diskstreams ()
  71 {
  72         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
  73         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
  74                 (*i)->prepare ();
  75         }
  76 }
  77
  78 int
  79 Session::fail_roll (nframes_t nframes)
  80 {
  81         Port::set_port_offset (0);
  82         return no_roll (nframes);
  83
  84 }
  85
  86 int
  87 Session::no_roll (nframes_t nframes)
  88 {
  89         nframes_t end_frame = _transport_frame + nframes;
  90         int ret = 0;
  91         bool declick = get_transport_declick_required();
  92         boost::shared_ptr<RouteList> r = routes.reader ();
  93
  94         if (_click_io) {
  95                 _click_io->silence (nframes);
  96         }
  97
  98         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
  99
 100                 if ((*i)->hidden()) {
 101                         continue;
 102                 }
 103
 104                 (*i)->set_pending_declick (declick);
 105
 106                 if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending(),
 107                                    actively_recording(), declick)) {
 108                         error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
 109                         ret = -1;
 110                         break;
 111                 }
 112         }
 113
 114         return ret;
 115 }
 116
 117 int
 118 Session::process_routes (nframes_t nframes)
 119 {
 120         bool record_active;
 121         int  declick = get_transport_declick_required();
 122         bool rec_monitors = get_rec_monitors_input();
 123         boost::shared_ptr<RouteList> r = routes.reader ();
 124
 125         if (transport_sub_state & StopPendingCapture) {
 126                 /* force a declick out */
 127                 declick = -1;
 128         }
 129
 130         record_active = actively_recording(); // || (get_record_enabled() && get_punch_in());
 131
 132         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 133
 134                 int ret;
 135
 136                 if ((*i)->hidden()) {
 137                         continue;
 138                 }
 139
 140                 (*i)->set_pending_declick (declick);
 141
 142                 if ((ret = (*i)->roll (nframes, _transport_frame, _transport_frame + nframes, declick, record_active, rec_monitors)) < 0) {
 143
 144                         /* we have to do this here. Route::roll() for an AudioTrack will have called AudioDiskstream::process(),
 145                            and the DS will expect AudioDiskstream::commit() to be called. but we're aborting from that
 146                            call path, so make sure we release any outstanding locks here before we return failure.
 147                         */
 148
 149                         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 150                         for (DiskstreamList::iterator ids = dsl->begin(); ids != dsl->end(); ++ids) {
 151                                 (*ids)->recover ();
 152                         }
 153
 154                         stop_transport ();
 155                         return -1;
 156                 }
 157         }
 158
 159         return 0;
 160 }
 161
 162 int
 163 Session::silent_process_routes (nframes_t nframes)
 164 {
 165         bool record_active = actively_recording();
 166         int  declick = get_transport_declick_required();
 167         bool rec_monitors = get_rec_monitors_input();
 168         boost::shared_ptr<RouteList> r = routes.reader ();
 169
 170         if (transport_sub_state & StopPendingCapture) {
 171                 /* force a declick out */
 172                 declick = -1;
 173         }
 174
 175         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 176
 177                 int ret;
 178
 179                 if ((*i)->hidden()) {
 180                         continue;
 181                 }
 182
 183                 if ((ret = (*i)->silent_roll (nframes, _transport_frame, _transport_frame + nframes, record_active, rec_monitors)) < 0) {
 184
 185                         /* we have to do this here. Route::roll() for an AudioTrack will have called AudioDiskstream::process(),
 186                            and the DS will expect AudioDiskstream::commit() to be called. but we're aborting from that
 187                            call path, so make sure we release any outstanding locks here before we return failure.
 188                         */
 189
 190                         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 191                         for (DiskstreamList::iterator ids = dsl->begin(); ids != dsl->end(); ++ids) {
 192                                 (*ids)->recover ();
 193                         }
 194
 195                         stop_transport ();
 196                         return -1;
 197                 }
 198         }
 199
 200         return 0;
 201 }
 202
 203 void
 204 Session::commit_diskstreams (nframes_t nframes, bool &needs_butler)
 205 {
 206         int dret;
 207         float pworst = 1.0f;
 208         float cworst = 1.0f;
 209
 210         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 211         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 212
 213                 if ((*i)->hidden()) {
 214                         continue;
 215                 }
 216
 217                 /* force all diskstreams not handled by a Route to call do their stuff.
 218                    Note: the diskstreams that were handled by a route will just return zero
 219                    from this call, because they know they were processed. So in fact, this
 220                    also runs commit() for every diskstream.
 221                  */
 222
 223                 if ((dret = (*i)->process (_transport_frame, nframes, actively_recording(), get_rec_monitors_input())) == 0) {
 224                         if ((*i)->commit (nframes)) {
 225                                 needs_butler = true;
 226                         }
 227
 228                 } else if (dret < 0) {
 229                         (*i)->recover();
 230                 }
 231
 232                 pworst = min (pworst, (*i)->playback_buffer_load());
 233                 cworst = min (cworst, (*i)->capture_buffer_load());
 234         }
 235
 236         uint32_t pmin = g_atomic_int_get (&_playback_load);
 237         uint32_t pminold = g_atomic_int_get (&_playback_load_min);
 238         uint32_t cmin = g_atomic_int_get (&_capture_load);
 239         uint32_t cminold = g_atomic_int_get (&_capture_load_min);
 240
 241         g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 242         g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
 243         g_atomic_int_set (&_playback_load_min, min (pmin, pminold));
 244         g_atomic_int_set (&_capture_load_min, min (cmin, cminold));
 245
 246         if (actively_recording()) {
 247                 set_dirty();
 248         }
 249 }
 250
 251 void
 252 Session::process_with_events (nframes_t nframes)
 253 {
 254         Event* ev;
 255         nframes_t this_nframes;
 256         nframes_t end_frame;
 257
 258         bool session_needs_butler = false;
 259         nframes_t stop_limit;
 260         long           frames_moved;
 261
 262         /* make sure the auditioner is silent */
 263
 264         if (auditioner) {
 265                 auditioner->silence (nframes);
 266         }
 267
 268         /* handle any pending events */
 269
 270         while (pending_events.read (&ev, 1) == 1) {
 271                 merge_event (ev);
 272         }
 273
 274         /* if we are not in the middle of a state change,
 275            and there are immediate events queued up,
 276            process them.
 277         */
 278
 279         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 280                 Event *ev = immediate_events.front ();
 281                 immediate_events.pop_front ();
 282                 process_event (ev);
 283         }
 284
 285         /* Events caused a transport change, send an MTC Full Frame (SMPTE) message.
 286          * This is sent whether rolling or not, to give slaves an idea of ardour time
 287          * on locates (and allow slow slaves to position and prepare for rolling)
 288          */
 289         if (_send_smpte_update) {
 290                 send_full_time_code ();
 291         }
 292
 293         if (!process_can_proceed()) {
 294                 _silent = true;
 295                 return;
 296         }
 297
 298         if (events.empty() || next_event == events.end()) {
 299                 process_without_events (nframes);
 300                 return;
 301         }
 302
 303         end_frame = _transport_frame + (nframes_t)abs(floor(nframes * _transport_speed));
 304
 305         {
 306                 Event* this_event;
 307                 Events::iterator the_next_one;
 308
 309                 if (!process_can_proceed()) {
 310                         _silent = true;
 311                         return;
 312                 }
 313
 314                 if (!_exporting && _slave) {
 315                         if (!follow_slave (nframes)) {
 316                                 return;
 317                         }
 318                 }
 319
 320                 if (_transport_speed == 0) {
 321                         no_roll (nframes);
 322                         return;
 323                 }
 324
 325                 if (actively_recording()) {
 326                         stop_limit = max_frames;
 327                 } else {
 328
 329                         if (Config->get_stop_at_session_end()) {
 330                                 stop_limit = current_end_frame();
 331                         } else {
 332                                 stop_limit = max_frames;
 333                         }
 334                 }
 335
 336                 if (maybe_stop (stop_limit)) {
 337                         no_roll (nframes);
 338                         return;
 339                 }
 340
 341                 this_event = *next_event;
 342                 the_next_one = next_event;
 343                 ++the_next_one;
 344
 345
 346                 while (nframes) {
 347
 348                         this_nframes = nframes; /* real (jack) time relative */
 349                         frames_moved = (long) floor (_transport_speed * nframes); /* transport relative */
 350
 351                         /* running an event, position transport precisely to its time */
 352                         if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
 353                                 /* this isn't quite right for reverse play */
 354                                 frames_moved = (long) (this_event->action_frame - _transport_frame);
 355                                 this_nframes = (nframes_t) abs( floor(frames_moved / _transport_speed) );
 356                         }
 357
 358                         if (this_nframes) {
 359
 360                                 click (_transport_frame, nframes);
 361
 362                                 /* now process frames between now and the first event in this block */
 363                                 prepare_diskstreams ();
 364
 365                                 if (process_routes (this_nframes)) {
 366                                         fail_roll (nframes);
 367                                         return;
 368                                 }
 369
 370                                 commit_diskstreams (this_nframes, session_needs_butler);
 371
 372                                 nframes -= this_nframes;
 373
 374                                 if (frames_moved < 0) {
 375                                         decrement_transport_position (-frames_moved);
 376                                 } else {
 377                                         increment_transport_position (frames_moved);
 378                                 }
 379
 380                                 maybe_stop (stop_limit);
 381                                 check_declick_out ();
 382                         }
 383
 384                         /* reset port offsets so that Port::get_buffer() will fetch the correct data */
 385
 386                         Port::increment_port_offset (this_nframes);
 387
 388                         /* now handle this event and all others scheduled for the same time */
 389
 390                         while (this_event && this_event->action_frame == _transport_frame) {
 391                                 process_event (this_event);
 392
 393                                 if (the_next_one == events.end()) {
 394                                         this_event = 0;
 395                                 } else {
 396                                         this_event = *the_next_one;
 397                                         ++the_next_one;
 398                                 }
 399                         }
 400
 401                         /* if an event left our state changing, do the right thing */
 402
 403                         if (nframes && non_realtime_work_pending()) {
 404                                 no_roll (nframes);
 405                                 break;
 406                         }
 407
 408                         /* this is necessary to handle the case of seamless looping */
 409                         end_frame = _transport_frame + (nframes_t) floor (nframes * _transport_speed);
 410                 }
 411
 412                 set_next_event ();
 413
 414         } /* implicit release of route lock */
 415
 416
 417         if (session_needs_butler) {
 418                 summon_butler ();
 419         }
 420
 421         if (!_engine.freewheeling() && session_send_mtc) {
 422                 send_midi_time_code_in_another_thread ();
 423         }
 424
 425         return;
 426 }
 427
 428 void
 429 Session::reset_slave_state ()
 430 {
 431         average_slave_delta = 1800;
 432         delta_accumulator_cnt = 0;
 433         have_first_delta_accumulator = false;
 434         slave_state = Stopped;
 435 }
 436
 437 bool
 438 Session::transport_locked () const
 439 {
 440         Slave* sl = _slave;
 441
 442         if (!locate_pending() && ((Config->get_slave_source() == None) || (sl && sl->ok() && sl->locked()))) {
 443                 return true;
 444         }
 445
 446         return false;
 447 }
 448
 449 bool
 450 Session::follow_slave (nframes_t nframes)
 451 {
 452         float slave_speed;
 453         nframes_t slave_transport_frame;
 454         nframes_t this_delta;
 455         int dir;
 456         bool starting;
 457
 458         if (!_slave->ok()) {
 459                 stop_transport ();
 460                 Config->set_slave_source (None);
 461                 goto noroll;
 462         }
 463
 464         _slave->speed_and_position (slave_speed, slave_transport_frame);
 465
 466         if (!_slave->locked()) {
 467                 // cerr << "Slave not locked, not rolling\n";
 468                 goto noroll;
 469         }
 470
 471         if (slave_transport_frame > _transport_frame) {
 472                 this_delta = slave_transport_frame - _transport_frame;
 473                 dir = 1;
 474         } else {
 475                 this_delta = _transport_frame - slave_transport_frame;
 476                 dir = -1;
 477         }
 478
 479         if ((starting = _slave->starting())) {
 480                 slave_speed = 0.0f;
 481         }
 482
 483 #if 0
 484         cerr << "delta = " << (int) (dir * this_delta)
 485              << " speed = " << slave_speed
 486              << " ts = " << _transport_speed
 487              << " M@ "<< slave_transport_frame << " S@ " << _transport_frame
 488              << " avgdelta = " << average_slave_delta
 489              << endl;
 490 #endif
 491
 492         if (_slave->is_always_synced() || Config->get_timecode_source_is_synced()) {
 493
 494                 /* if the TC source is synced, then we assume that its
 495                    speed is binary: 0.0 or 1.0
 496                 */
 497
 498                 if (slave_speed != 0.0f) {
 499                         slave_speed = 1.0f;
 500                 }
 501
 502         } else {
 503
 504                 /* TC source is able to drift relative to us (slave)
 505                    so we need to keep track of the drift and adjust
 506                    our speed to remain locked.
 507                 */
 508
 509                 if (delta_accumulator_cnt >= delta_accumulator_size) {
 510                         have_first_delta_accumulator = true;
 511                         delta_accumulator_cnt = 0;
 512                 }
 513
 514                 if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 515                         delta_accumulator[delta_accumulator_cnt++] = dir*this_delta;
 516                 }
 517
 518                 if (have_first_delta_accumulator) {
 519                         average_slave_delta = 0;
 520                         for (int i = 0; i < delta_accumulator_size; ++i) {
 521                                 average_slave_delta += delta_accumulator[i];
 522                         }
 523                         average_slave_delta /= delta_accumulator_size;
 524                         if (average_slave_delta < 0) {
 525                                 average_dir = -1;
 526                                 average_slave_delta = -average_slave_delta;
 527                         } else {
 528                                 average_dir = 1;
 529                         }
 530                         // cerr << "avgdelta = " << average_slave_delta*average_dir << endl;
 531                 }
 532         }
 533
 534         if (slave_speed != 0.0f) {
 535
 536                 /* slave is running */
 537
 538                 switch (slave_state) {
 539                 case Stopped:
 540                         if (_slave->requires_seekahead()) {
 541                                 slave_wait_end = slave_transport_frame + _current_frame_rate;
 542                                 locate (slave_wait_end, false, false);
 543                                 slave_state = Waiting;
 544                                 starting = true;
 545
 546                         } else {
 547
 548                                 slave_state = Running;
 549
 550                                 Location* al = _locations.auto_loop_location();
 551
 552                                 if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 553                                         // cancel looping
 554                                         request_play_loop(false);
 555                                 }
 556
 557                                 if (slave_transport_frame != _transport_frame) {
 558                                         locate (slave_transport_frame, false, false);
 559                                 }
 560                         }
 561                         break;
 562
 563                 case Waiting:
 564                         break;
 565
 566                 default:
 567                         break;
 568
 569                 }
 570
 571                 if (slave_state == Waiting) {
 572
 573                         // cerr << "waiting at " << slave_transport_frame << endl;
 574
 575                         if (slave_transport_frame >= slave_wait_end) {
 576                                 // cerr << "\tstart at " << _transport_frame << endl;
 577
 578                                 slave_state = Running;
 579
 580                                 bool ok = true;
 581                                 nframes_t frame_delta = slave_transport_frame - _transport_frame;
 582
 583                                 boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 584
 585                                 for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 586                                         if (!(*i)->can_internal_playback_seek (frame_delta)) {
 587                                                 ok = false;
 588                                                 break;
 589                                         }
 590                                 }
 591
 592                                 if (ok) {
 593                                         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 594                                                 (*i)->internal_playback_seek (frame_delta);
 595                                         }
 596                                         _transport_frame += frame_delta;
 597
 598                                 } else {
 599                                         // cerr << "cannot micro-seek\n";
 600                                         /* XXX what? */
 601                                 }
 602
 603                                 memset (delta_accumulator, 0, sizeof (nframes_t) * delta_accumulator_size);
 604                                 average_slave_delta = 0;
 605                                 this_delta = 0;
 606                         }
 607                 }
 608
 609                 if (slave_state == Running && _transport_speed == 0.0f) {
 610
 611                         // cerr << "slave starts transport\n";
 612
 613                         start_transport ();
 614                 }
 615
 616         } else {
 617
 618                 /* slave has stopped */
 619
 620                 if (_transport_speed != 0.0f) {
 621
 622                         // cerr << "slave stops transport: " << slave_speed << " frame: " << slave_transport_frame
 623                         // << " tf = " << _transport_frame
 624                         // << endl;
 625
 626                         if (Config->get_slave_source() == JACK) {
 627                                 last_stop_frame = _transport_frame;
 628                         }
 629
 630                         stop_transport();
 631                 }
 632
 633                 if (slave_transport_frame != _transport_frame) {
 634                         // cerr << "slave stopped, move to " << slave_transport_frame << endl;
 635                         force_locate (slave_transport_frame, false);
 636                 }
 637
 638                 slave_state = Stopped;
 639         }
 640
 641         if (slave_state == Running && !_slave->is_always_synced() && !Config->get_timecode_source_is_synced()) {
 642
 643
 644                 if (_transport_speed != 0.0f) {
 645
 646                         /*
 647                            note that average_dir is +1 or -1
 648                         */
 649
 650                         const float adjust_seconds = 1.0f;
 651                         float delta;
 652
 653                         //if (average_slave_delta == 0) {
 654                                 delta = this_delta;
 655                                 delta *= dir;
 656 //                      } else {
 657 //                              delta = average_slave_delta;
 658 //                              delta *= average_dir;
 659 //                      }
 660
 661                         float adjusted_speed = slave_speed +
 662                                 (delta / (adjust_seconds * _current_frame_rate));
 663
 664 #if 0
 665                         cerr << "adjust using " << delta
 666                              << " towards " << adjusted_speed
 667                              << " ratio = " << adjusted_speed / slave_speed
 668                              << " current = " << _transport_speed
 669                              << " slave @ " << slave_speed
 670                              << endl;
 671 #endif
 672
 673                         request_transport_speed (adjusted_speed);
 674
 675 #if 1
 676                         if ((nframes_t) average_slave_delta > _slave->resolution()) {
 677                                 // cerr << "not locked\n";
 678                                 goto silent_motion;
 679                         }
 680 #endif
 681                 }
 682         }
 683
 684         if (!starting && !non_realtime_work_pending()) {
 685                 /* speed is set, we're locked, and good to go */
 686                 return true;
 687         }
 688
 689   silent_motion:
 690
 691         if (slave_speed && _transport_speed) {
 692
 693                 /* something isn't right, but we should move with the master
 694                    for now.
 695                 */
 696
 697                 bool need_butler;
 698
 699                 prepare_diskstreams ();
 700                 silent_process_routes (nframes);
 701                 commit_diskstreams (nframes, need_butler);
 702
 703                 if (need_butler) {
 704                         summon_butler ();
 705                 }
 706
 707                 int32_t frames_moved = (int32_t) floor (_transport_speed * nframes);
 708
 709                 if (frames_moved < 0) {
 710                         decrement_transport_position (-frames_moved);
 711                 } else {
 712                         increment_transport_position (frames_moved);
 713                 }
 714
 715                 nframes_t stop_limit;
 716
 717                 if (actively_recording()) {
 718                         stop_limit = max_frames;
 719                 } else {
 720                         if (Config->get_stop_at_session_end()) {
 721                                 stop_limit = current_end_frame();
 722                         } else {
 723                                 stop_limit = max_frames;
 724                         }
 725                 }
 726
 727                 maybe_stop (stop_limit);
 728         }
 729
 730   noroll:
 731         /* don't move at all */
 732         no_roll (nframes);
 733         return false;
 734 }
 735
 736 void
 737 Session::process_without_events (nframes_t nframes)
 738 {
 739         bool session_needs_butler = false;
 740         nframes_t stop_limit;
 741         long frames_moved;
 742
 743         if (!process_can_proceed()) {
 744                 _silent = true;
 745                 return;
 746         }
 747
 748         if (!_exporting && _slave) {
 749                 if (!follow_slave (nframes)) {
 750                         return;
 751                 }
 752         }
 753
 754         if (_transport_speed == 0) {
 755                 fail_roll (nframes);
 756                 return;
 757         }
 758
 759         if (actively_recording()) {
 760                 stop_limit = max_frames;
 761         } else {
 762                 if (Config->get_stop_at_session_end()) {
 763                         stop_limit = current_end_frame();
 764                 } else {
 765                         stop_limit = max_frames;
 766                 }
 767         }
 768
 769         if (maybe_stop (stop_limit)) {
 770                 no_roll (nframes);
 771                 return;
 772         }
 773
 774         if (maybe_sync_start (nframes)) {
 775                 return;
 776         }
 777
 778         click (_transport_frame, nframes);
 779
 780         prepare_diskstreams ();
 781
 782         frames_moved = (long) floor (_transport_speed * nframes);
 783
 784         if (process_routes (nframes)) {
 785                 fail_roll (nframes);
 786                 return;
 787         }
 788
 789         commit_diskstreams (nframes, session_needs_butler);
 790
 791         if (frames_moved < 0) {
 792                 decrement_transport_position (-frames_moved);
 793         } else {
 794                 increment_transport_position (frames_moved);
 795         }
 796
 797         maybe_stop (stop_limit);
 798         check_declick_out ();
 799
 800         if (session_needs_butler) {
 801                 summon_butler ();
 802         }
 803
 804         if (!_engine.freewheeling() && session_send_mtc) {
 805                 send_midi_time_code_in_another_thread ();
 806         }
 807
 808         return;
 809 }
 810
 811 void
 812 Session::process_audition (nframes_t nframes)
 813 {
 814         Event* ev;
 815         boost::shared_ptr<RouteList> r = routes.reader ();
 816
 817         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 818                 if (!(*i)->hidden()) {
 819                         (*i)->silence (nframes);
 820                 }
 821         }
 822
 823         /* run the auditioner, and if it says we need butler service, ask for it */
 824
 825         if (auditioner->play_audition (nframes) > 0) {
 826                 summon_butler ();
 827         }
 828
 829         /* handle pending events */
 830
 831         while (pending_events.read (&ev, 1) == 1) {
 832                 merge_event (ev);
 833         }
 834
 835         /* if we are not in the middle of a state change,
 836            and there are immediate events queued up,
 837            process them.
 838         */
 839
 840         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 841                 Event *ev = immediate_events.front ();
 842                 immediate_events.pop_front ();
 843                 process_event (ev);
 844         }
 845
 846         if (!auditioner->active()) {
 847                 process_function = &Session::process_with_events;
 848         }
 849 }
 850
 851 bool
 852 Session::maybe_sync_start (nframes_t& nframes)
 853 {
 854         nframes_t sync_offset;
 855
 856         if (!waiting_for_sync_offset) {
 857                 return false;
 858         }
 859
 860         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
 861
 862                 /* generate silence up to the sync point, then
 863                    adjust nframes + offset to reflect whatever
 864                    is left to do.
 865                 */
 866
 867                 no_roll (sync_offset);
 868                 nframes -= sync_offset;
 869                 Port::increment_port_offset (sync_offset);
 870                 waiting_for_sync_offset = false;
 871
 872                 if (nframes == 0) {
 873                         return true; // done, nothing left to process
 874                 }
 875
 876         } else {
 877
 878                 /* sync offset point is not within this process()
 879                    cycle, so just generate silence. and don't bother
 880                    with any fancy stuff here, just the minimal silence.
 881                 */
 882
 883                 _silent = true;
 884
 885                 if (Config->get_locate_while_waiting_for_sync()) {
 886                         if (micro_locate (nframes)) {
 887                                 /* XXX ERROR !!! XXX */
 888                         }
 889                 }
 890
 891                 return true; // done, nothing left to process
 892         }
 893
 894         return false;
 895 }
 896