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         if (!process_can_proceed()) {
 286                 _silent = true;
 287                 return;
 288         }
 289
 290         if (events.empty() || next_event == events.end()) {
 291                 process_without_events (nframes);
 292                 return;
 293         }
 294
 295         end_frame = _transport_frame + (nframes_t)abs(floor(nframes * _transport_speed));
 296
 297         {
 298                 Event* this_event;
 299                 Events::iterator the_next_one;
 300
 301                 if (!process_can_proceed()) {
 302                         _silent = true;
 303                         return;
 304                 }
 305
 306                 if (!_exporting && _slave) {
 307                         if (!follow_slave (nframes)) {
 308                                 return;
 309                         }
 310                 }
 311
 312                 if (_transport_speed == 0) {
 313                         no_roll (nframes);
 314                         return;
 315                 }
 316
 317                 if (actively_recording()) {
 318                         stop_limit = max_frames;
 319                 } else {
 320
 321                         if (Config->get_stop_at_session_end()) {
 322                                 stop_limit = current_end_frame();
 323                         } else {
 324                                 stop_limit = max_frames;
 325                         }
 326                 }
 327
 328                 if (maybe_stop (stop_limit)) {
 329                         no_roll (nframes);
 330                         return;
 331                 }
 332
 333                 this_event = *next_event;
 334                 the_next_one = next_event;
 335                 ++the_next_one;
 336
 337
 338                 while (nframes) {
 339
 340                         this_nframes = nframes; /* real (jack) time relative */
 341                         frames_moved = (long) floor (_transport_speed * nframes); /* transport relative */
 342
 343                         /* running an event, position transport precisely to its time */
 344                         if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
 345                                 /* this isn't quite right for reverse play */
 346                                 frames_moved = (long) (this_event->action_frame - _transport_frame);
 347                                 this_nframes = (nframes_t) abs( floor(frames_moved / _transport_speed) );
 348                         }
 349
 350                         if (this_nframes) {
 351
 352                                 click (_transport_frame, nframes);
 353
 354                                 /* now process frames between now and the first event in this block */
 355                                 prepare_diskstreams ();
 356
 357                                 if (process_routes (this_nframes)) {
 358                                         fail_roll (nframes);
 359                                         return;
 360                                 }
 361
 362                                 commit_diskstreams (this_nframes, session_needs_butler);
 363
 364                                 nframes -= this_nframes;
 365
 366                                 if (frames_moved < 0) {
 367                                         decrement_transport_position (-frames_moved);
 368                                 } else {
 369                                         increment_transport_position (frames_moved);
 370                                 }
 371
 372                                 maybe_stop (stop_limit);
 373                                 check_declick_out ();
 374                         }
 375
 376                         /* reset port offsets so that Port::get_buffer() will fetch the correct data */
 377
 378                         Port::increment_port_offset (this_nframes);
 379
 380                         /* now handle this event and all others scheduled for the same time */
 381
 382                         while (this_event && this_event->action_frame == _transport_frame) {
 383                                 process_event (this_event);
 384
 385                                 if (the_next_one == events.end()) {
 386                                         this_event = 0;
 387                                 } else {
 388                                         this_event = *the_next_one;
 389                                         ++the_next_one;
 390                                 }
 391                         }
 392
 393                         /* if an event left our state changing, do the right thing */
 394
 395                         if (nframes && non_realtime_work_pending()) {
 396                                 no_roll (nframes);
 397                                 break;
 398                         }
 399
 400                         /* this is necessary to handle the case of seamless looping */
 401                         end_frame = _transport_frame + (nframes_t) floor (nframes * _transport_speed);
 402                 }
 403
 404                 set_next_event ();
 405
 406         } /* implicit release of route lock */
 407
 408
 409         if (session_needs_butler) {
 410                 summon_butler ();
 411         }
 412
 413         if (!_engine.freewheeling() && session_send_mtc) {
 414                 send_midi_time_code_in_another_thread ();
 415         }
 416
 417         return;
 418 }
 419
 420 void
 421 Session::reset_slave_state ()
 422 {
 423         average_slave_delta = 1800;
 424         delta_accumulator_cnt = 0;
 425         have_first_delta_accumulator = false;
 426         slave_state = Stopped;
 427 }
 428
 429 bool
 430 Session::transport_locked () const
 431 {
 432         Slave* sl = _slave;
 433
 434         if (!locate_pending() && ((Config->get_slave_source() == None) || (sl && sl->ok() && sl->locked()))) {
 435                 return true;
 436         }
 437
 438         return false;
 439 }
 440
 441 bool
 442 Session::follow_slave (nframes_t nframes)
 443 {
 444         float slave_speed;
 445         nframes_t slave_transport_frame;
 446         nframes_t this_delta;
 447         int dir;
 448         bool starting;
 449
 450         if (!_slave->ok()) {
 451                 stop_transport ();
 452                 Config->set_slave_source (None);
 453                 goto noroll;
 454         }
 455
 456         _slave->speed_and_position (slave_speed, slave_transport_frame);
 457
 458         if (!_slave->locked()) {
 459                 // cerr << "Slave not locked, not rolling\n";
 460                 goto noroll;
 461         }
 462
 463         if (slave_transport_frame > _transport_frame) {
 464                 this_delta = slave_transport_frame - _transport_frame;
 465                 dir = 1;
 466         } else {
 467                 this_delta = _transport_frame - slave_transport_frame;
 468                 dir = -1;
 469         }
 470
 471         if ((starting = _slave->starting())) {
 472                 slave_speed = 0.0f;
 473         }
 474
 475 #if 0
 476         cerr << "delta = " << (int) (dir * this_delta)
 477              << " speed = " << slave_speed
 478              << " ts = " << _transport_speed
 479              << " M@ "<< slave_transport_frame << " S@ " << _transport_frame
 480              << " avgdelta = " << average_slave_delta
 481              << endl;
 482 #endif
 483
 484         if (_slave->is_always_synced() || Config->get_timecode_source_is_synced()) {
 485
 486                 /* if the TC source is synced, then we assume that its
 487                    speed is binary: 0.0 or 1.0
 488                 */
 489
 490                 if (slave_speed != 0.0f) {
 491                         slave_speed = 1.0f;
 492                 }
 493
 494         } else {
 495
 496                 /* TC source is able to drift relative to us (slave)
 497                    so we need to keep track of the drift and adjust
 498                    our speed to remain locked.
 499                 */
 500
 501                 if (delta_accumulator_cnt >= delta_accumulator_size) {
 502                         have_first_delta_accumulator = true;
 503                         delta_accumulator_cnt = 0;
 504                 }
 505
 506                 if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 507                         delta_accumulator[delta_accumulator_cnt++] = dir*this_delta;
 508                 }
 509
 510                 if (have_first_delta_accumulator) {
 511                         average_slave_delta = 0;
 512                         for (int i = 0; i < delta_accumulator_size; ++i) {
 513                                 average_slave_delta += delta_accumulator[i];
 514                         }
 515                         average_slave_delta /= delta_accumulator_size;
 516                         if (average_slave_delta < 0) {
 517                                 average_dir = -1;
 518                                 average_slave_delta = -average_slave_delta;
 519                         } else {
 520                                 average_dir = 1;
 521                         }
 522                         // cerr << "avgdelta = " << average_slave_delta*average_dir << endl;
 523                 }
 524         }
 525
 526         if (slave_speed != 0.0f) {
 527
 528                 /* slave is running */
 529
 530                 switch (slave_state) {
 531                 case Stopped:
 532                         if (_slave->requires_seekahead()) {
 533                                 slave_wait_end = slave_transport_frame + _current_frame_rate;
 534                                 locate (slave_wait_end, false, false);
 535                                 slave_state = Waiting;
 536                                 starting = true;
 537
 538                         } else {
 539
 540                                 slave_state = Running;
 541
 542                                 Location* al = _locations.auto_loop_location();
 543
 544                                 if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 545                                         // cancel looping
 546                                         request_play_loop(false);
 547                                 }
 548
 549                                 if (slave_transport_frame != _transport_frame) {
 550                                         locate (slave_transport_frame, false, false);
 551                                 }
 552                         }
 553                         break;
 554
 555                 case Waiting:
 556                         break;
 557
 558                 default:
 559                         break;
 560
 561                 }
 562
 563                 if (slave_state == Waiting) {
 564
 565                         // cerr << "waiting at " << slave_transport_frame << endl;
 566
 567                         if (slave_transport_frame >= slave_wait_end) {
 568                                 // cerr << "\tstart at " << _transport_frame << endl;
 569
 570                                 slave_state = Running;
 571
 572                                 bool ok = true;
 573                                 nframes_t frame_delta = slave_transport_frame - _transport_frame;
 574
 575                                 boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 576
 577                                 for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 578                                         if (!(*i)->can_internal_playback_seek (frame_delta)) {
 579                                                 ok = false;
 580                                                 break;
 581                                         }
 582                                 }
 583
 584                                 if (ok) {
 585                                         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 586                                                 (*i)->internal_playback_seek (frame_delta);
 587                                         }
 588                                         _transport_frame += frame_delta;
 589
 590                                 } else {
 591                                         // cerr << "cannot micro-seek\n";
 592                                         /* XXX what? */
 593                                 }
 594
 595                                 memset (delta_accumulator, 0, sizeof (nframes_t) * delta_accumulator_size);
 596                                 average_slave_delta = 0;
 597                                 this_delta = 0;
 598                         }
 599                 }
 600
 601                 if (slave_state == Running && _transport_speed == 0.0f) {
 602
 603                         // cerr << "slave starts transport\n";
 604
 605                         start_transport ();
 606                 }
 607
 608         } else {
 609
 610                 /* slave has stopped */
 611
 612                 if (_transport_speed != 0.0f) {
 613
 614                         // cerr << "slave stops transport: " << slave_speed << " frame: " << slave_transport_frame
 615                         // << " tf = " << _transport_frame
 616                         // << endl;
 617
 618                         if (Config->get_slave_source() == JACK) {
 619                                 last_stop_frame = _transport_frame;
 620                         }
 621
 622                         stop_transport();
 623                 }
 624
 625                 if (slave_transport_frame != _transport_frame) {
 626                         // cerr << "slave stopped, move to " << slave_transport_frame << endl;
 627                         force_locate (slave_transport_frame, false);
 628                 }
 629
 630                 slave_state = Stopped;
 631         }
 632
 633         if (slave_state == Running && !_slave->is_always_synced() && !Config->get_timecode_source_is_synced()) {
 634
 635
 636                 if (_transport_speed != 0.0f) {
 637
 638                         /*
 639                            note that average_dir is +1 or -1
 640                         */
 641
 642                         const float adjust_seconds = 1.0f;
 643                         float delta;
 644
 645                         //if (average_slave_delta == 0) {
 646                                 delta = this_delta;
 647                                 delta *= dir;
 648 //                      } else {
 649 //                              delta = average_slave_delta;
 650 //                              delta *= average_dir;
 651 //                      }
 652
 653                         float adjusted_speed = slave_speed +
 654                                 (delta / (adjust_seconds * _current_frame_rate));
 655
 656 #if 0
 657                         cerr << "adjust using " << delta
 658                              << " towards " << adjusted_speed
 659                              << " ratio = " << adjusted_speed / slave_speed
 660                              << " current = " << _transport_speed
 661                              << " slave @ " << slave_speed
 662                              << endl;
 663 #endif
 664
 665                         request_transport_speed (adjusted_speed);
 666
 667 #if 1
 668                         if ((nframes_t) average_slave_delta > _slave->resolution()) {
 669                                 // cerr << "not locked\n";
 670                                 goto silent_motion;
 671                         }
 672 #endif
 673                 }
 674         }
 675
 676         if (!starting && !non_realtime_work_pending()) {
 677                 /* speed is set, we're locked, and good to go */
 678                 return true;
 679         }
 680
 681   silent_motion:
 682
 683         if (slave_speed && _transport_speed) {
 684
 685                 /* something isn't right, but we should move with the master
 686                    for now.
 687                 */
 688
 689                 bool need_butler;
 690
 691                 prepare_diskstreams ();
 692                 silent_process_routes (nframes);
 693                 commit_diskstreams (nframes, need_butler);
 694
 695                 if (need_butler) {
 696                         summon_butler ();
 697                 }
 698
 699                 int32_t frames_moved = (int32_t) floor (_transport_speed * nframes);
 700
 701                 if (frames_moved < 0) {
 702                         decrement_transport_position (-frames_moved);
 703                 } else {
 704                         increment_transport_position (frames_moved);
 705                 }
 706
 707                 nframes_t stop_limit;
 708
 709                 if (actively_recording()) {
 710                         stop_limit = max_frames;
 711                 } else {
 712                         if (Config->get_stop_at_session_end()) {
 713                                 stop_limit = current_end_frame();
 714                         } else {
 715                                 stop_limit = max_frames;
 716                         }
 717                 }
 718
 719                 maybe_stop (stop_limit);
 720         }
 721
 722   noroll:
 723         /* don't move at all */
 724         no_roll (nframes);
 725         return false;
 726 }
 727
 728 void
 729 Session::process_without_events (nframes_t nframes)
 730 {
 731         bool session_needs_butler = false;
 732         nframes_t stop_limit;
 733         long frames_moved;
 734
 735         if (!process_can_proceed()) {
 736                 _silent = true;
 737                 return;
 738         }
 739
 740         if (!_exporting && _slave) {
 741                 if (!follow_slave (nframes)) {
 742                         return;
 743                 }
 744         }
 745
 746         if (_transport_speed == 0) {
 747                 fail_roll (nframes);
 748                 return;
 749         }
 750
 751         if (actively_recording()) {
 752                 stop_limit = max_frames;
 753         } else {
 754                 if (Config->get_stop_at_session_end()) {
 755                         stop_limit = current_end_frame();
 756                 } else {
 757                         stop_limit = max_frames;
 758                 }
 759         }
 760
 761         if (maybe_stop (stop_limit)) {
 762                 no_roll (nframes);
 763                 return;
 764         }
 765
 766         if (maybe_sync_start (nframes)) {
 767                 return;
 768         }
 769
 770         click (_transport_frame, nframes);
 771
 772         prepare_diskstreams ();
 773
 774         frames_moved = (long) floor (_transport_speed * nframes);
 775
 776         if (process_routes (nframes)) {
 777                 fail_roll (nframes);
 778                 return;
 779         }
 780
 781         commit_diskstreams (nframes, session_needs_butler);
 782
 783         if (frames_moved < 0) {
 784                 decrement_transport_position (-frames_moved);
 785         } else {
 786                 increment_transport_position (frames_moved);
 787         }
 788
 789         maybe_stop (stop_limit);
 790         check_declick_out ();
 791
 792         if (session_needs_butler) {
 793                 summon_butler ();
 794         }
 795
 796         if (!_engine.freewheeling() && session_send_mtc) {
 797                 send_midi_time_code_in_another_thread ();
 798         }
 799
 800         return;
 801 }
 802
 803 void
 804 Session::process_audition (nframes_t nframes)
 805 {
 806         Event* ev;
 807         boost::shared_ptr<RouteList> r = routes.reader ();
 808
 809         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 810                 if (!(*i)->hidden()) {
 811                         (*i)->silence (nframes);
 812                 }
 813         }
 814
 815         /* run the auditioner, and if it says we need butler service, ask for it */
 816
 817         if (auditioner->play_audition (nframes) > 0) {
 818                 summon_butler ();
 819         }
 820
 821         /* handle pending events */
 822
 823         while (pending_events.read (&ev, 1) == 1) {
 824                 merge_event (ev);
 825         }
 826
 827         /* if we are not in the middle of a state change,
 828            and there are immediate events queued up,
 829            process them.
 830         */
 831
 832         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 833                 Event *ev = immediate_events.front ();
 834                 immediate_events.pop_front ();
 835                 process_event (ev);
 836         }
 837
 838         if (!auditioner->active()) {
 839                 process_function = &Session::process_with_events;
 840         }
 841 }
 842
 843 bool
 844 Session::maybe_sync_start (nframes_t& nframes)
 845 {
 846         nframes_t sync_offset;
 847
 848         if (!waiting_for_sync_offset) {
 849                 return false;
 850         }
 851
 852         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
 853
 854                 /* generate silence up to the sync point, then
 855                    adjust nframes + offset to reflect whatever
 856                    is left to do.
 857                 */
 858
 859                 no_roll (sync_offset);
 860                 nframes -= sync_offset;
 861                 Port::increment_port_offset (sync_offset);
 862                 waiting_for_sync_offset = false;
 863
 864                 if (nframes == 0) {
 865                         return true; // done, nothing left to process
 866                 }
 867
 868         } else {
 869
 870                 /* sync offset point is not within this process()
 871                    cycle, so just generate silence. and don't bother
 872                    with any fancy stuff here, just the minimal silence.
 873                 */
 874
 875                 _silent = true;
 876
 877                 if (Config->get_locate_while_waiting_for_sync()) {
 878                         if (micro_locate (nframes)) {
 879                                 /* XXX ERROR !!! XXX */
 880                         }
 881                 }
 882
 883                 return true; // done, nothing left to process
 884         }
 885
 886         return false;
 887 }
 888