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 "midi++/manager.h"
  40
  41 #include "i18n.h"
  42
  43 using namespace ARDOUR;
  44 using namespace PBD;
  45 using namespace std;
  46
  47 /** Called by the audio engine when there is work to be done with JACK.
  48  * @param nframes Number of frames to process.
  49  */
  50 void
  51 Session::process (nframes_t nframes)
  52 {
  53         // This is no more the appropriate place to call cycle
  54         // start. cycle_start needs to be called at the Route::roll()
  55         // where the signals which we want to mixdown have been calculated.
  56         //
  57         MIDI::Manager::instance()->cycle_start(nframes);
  58
  59         _silent = false;
  60
  61         if (non_realtime_work_pending()) {
  62                 if (!transport_work_requested ()) {
  63                         post_transport ();
  64                 }
  65         }
  66
  67         (this->*process_function) (nframes);
  68
  69         // the ticker is for sending time information like MidiClock
  70         nframes_t transport_frames = transport_frame();
  71         BBT_Time  transport_bbt;
  72         bbt_time(transport_frames, transport_bbt);
  73         SMPTE::Time transport_smpte;
  74         smpte_time(transport_frames, transport_smpte);
  75         tick (transport_frames, transport_bbt, transport_smpte); /* EMIT SIGNAL */
  76
  77         SendFeedback (); /* EMIT SIGNAL */
  78
  79         MIDI::Manager::instance()->cycle_end();
  80 }
  81
  82 void
  83 Session::prepare_diskstreams ()
  84 {
  85         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
  86         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
  87                 (*i)->prepare ();
  88         }
  89 }
  90
  91 int
  92 Session::no_roll (nframes_t nframes, nframes_t offset)
  93 {
  94         nframes_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
  95         int ret = 0;
  96         bool declick = get_transport_declick_required();
  97         boost::shared_ptr<RouteList> r = routes.reader ();
  98
  99         if (_click_io) {
 100                 _click_io->silence (nframes, offset);
 101         }
 102
 103         if (g_atomic_int_get (&processing_prohibited)) {
 104                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 105                         (*i)->silence (nframes, offset);
 106                 }
 107                 return 0;
 108         }
 109
 110         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 111
 112                 if ((*i)->is_hidden()) {
 113                         continue;
 114                 }
 115
 116                 (*i)->set_pending_declick (declick);
 117
 118                 if ((*i)->no_roll (nframes, _transport_frame, end_frame, offset, non_realtime_work_pending(),
 119                                    actively_recording(), declick)) {
 120                         error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
 121                         ret = -1;
 122                         break;
 123                 }
 124         }
 125
 126         return ret;
 127 }
 128
 129 int
 130 Session::process_routes (nframes_t nframes, nframes_t offset)
 131 {
 132         bool record_active;
 133         int  declick = get_transport_declick_required();
 134         bool rec_monitors = get_rec_monitors_input();
 135         boost::shared_ptr<RouteList> r = routes.reader ();
 136
 137         if (transport_sub_state & StopPendingCapture) {
 138                 /* force a declick out */
 139                 declick = -1;
 140         }
 141
 142         record_active = actively_recording(); // || (get_record_enabled() && get_punch_in());
 143
 144         const nframes_t start_frame = _transport_frame;
 145         const nframes_t end_frame = _transport_frame + (nframes_t)floor(nframes * _transport_speed);
 146
 147         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 148
 149                 int ret;
 150
 151                 if ((*i)->is_hidden()) {
 152                         continue;
 153                 }
 154
 155                 (*i)->set_pending_declick (declick);
 156
 157                 if ((ret = (*i)->roll (nframes, start_frame, end_frame, offset, declick, record_active, rec_monitors)) < 0) {
 158
 159                         /* we have to do this here. Route::roll() for an AudioTrack will have called AudioDiskstream::process(),
 160                            and the DS will expect AudioDiskstream::commit() to be called. but we're aborting from that
 161                            call path, so make sure we release any outstanding locks here before we return failure.
 162                         */
 163
 164                         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 165                         for (DiskstreamList::iterator ids = dsl->begin(); ids != dsl->end(); ++ids) {
 166                                 (*ids)->recover ();
 167                         }
 168
 169                         stop_transport ();
 170                         return -1;
 171                 }
 172         }
 173
 174         return 0;
 175 }
 176
 177 int
 178 Session::silent_process_routes (nframes_t nframes, nframes_t offset)
 179 {
 180         bool record_active = actively_recording();
 181         int  declick = get_transport_declick_required();
 182         bool rec_monitors = get_rec_monitors_input();
 183         boost::shared_ptr<RouteList> r = routes.reader ();
 184
 185         if (transport_sub_state & StopPendingCapture) {
 186                 /* force a declick out */
 187                 declick = -1;
 188         }
 189
 190         const nframes_t start_frame = _transport_frame;
 191         const nframes_t end_frame = _transport_frame + lrintf(nframes * _transport_speed);
 192
 193         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 194
 195                 int ret;
 196
 197                 if ((*i)->is_hidden()) {
 198                         continue;
 199                 }
 200
 201                 if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, offset, record_active, rec_monitors)) < 0) {
 202
 203                         /* we have to do this here. Route::roll() for an AudioTrack will have called AudioDiskstream::process(),
 204                            and the DS will expect AudioDiskstream::commit() to be called. but we're aborting from that
 205                            call path, so make sure we release any outstanding locks here before we return failure.
 206                         */
 207
 208                         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 209                         for (DiskstreamList::iterator ids = dsl->begin(); ids != dsl->end(); ++ids) {
 210                                 (*ids)->recover ();
 211                         }
 212
 213                         stop_transport ();
 214                         return -1;
 215                 }
 216         }
 217
 218         return 0;
 219 }
 220
 221 void
 222 Session::commit_diskstreams (nframes_t nframes, bool &needs_butler)
 223 {
 224         int dret;
 225         float pworst = 1.0f;
 226         float cworst = 1.0f;
 227
 228         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 229         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 230
 231                 if ((*i)->hidden()) {
 232                         continue;
 233                 }
 234
 235                 /* force all diskstreams not handled by a Route to call do their stuff.
 236                    Note: the diskstreams that were handled by a route will just return zero
 237                    from this call, because they know they were processed. So in fact, this
 238                    also runs commit() for every diskstream.
 239                  */
 240
 241                 if ((dret = (*i)->process (_transport_frame, nframes, 0, actively_recording(), get_rec_monitors_input())) == 0) {
 242                         if ((*i)->commit (nframes)) {
 243                                 needs_butler = true;
 244                         }
 245
 246                 } else if (dret < 0) {
 247                         (*i)->recover();
 248                 }
 249
 250                 pworst = min (pworst, (*i)->playback_buffer_load());
 251                 cworst = min (cworst, (*i)->capture_buffer_load());
 252         }
 253
 254         uint32_t pmin = g_atomic_int_get (&_playback_load);
 255         uint32_t pminold = g_atomic_int_get (&_playback_load_min);
 256         uint32_t cmin = g_atomic_int_get (&_capture_load);
 257         uint32_t cminold = g_atomic_int_get (&_capture_load_min);
 258
 259         g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 260         g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
 261         g_atomic_int_set (&_playback_load_min, min (pmin, pminold));
 262         g_atomic_int_set (&_capture_load_min, min (cmin, cminold));
 263
 264         if (actively_recording()) {
 265                 set_dirty();
 266         }
 267 }
 268
 269 /** Process callback used when the auditioner is not active */
 270 void
 271 Session::process_with_events (nframes_t nframes)
 272 {
 273         Event*         ev;
 274         nframes_t      this_nframes;
 275         nframes_t      end_frame;
 276         nframes_t      offset;
 277         bool           session_needs_butler = false;
 278         nframes_t      stop_limit;
 279         long           frames_moved;
 280
 281         /* make sure the auditioner is silent */
 282
 283         if (auditioner) {
 284                 auditioner->silence (nframes, 0);
 285         }
 286
 287         /* handle any pending events */
 288
 289         while (pending_events.read (&ev, 1) == 1) {
 290                 merge_event (ev);
 291         }
 292
 293         /* if we are not in the middle of a state change,
 294            and there are immediate events queued up,
 295            process them.
 296         */
 297
 298         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 299                 Event *ev = immediate_events.front ();
 300                 immediate_events.pop_front ();
 301                 process_event (ev);
 302         }
 303
 304         /* Events caused a transport change, send an MTC Full Frame (SMPTE) message.
 305          * This is sent whether rolling or not, to give slaves an idea of ardour time
 306          * on locates (and allow slow slaves to position and prepare for rolling)
 307          */
 308         if (_send_smpte_update) {
 309                 send_full_time_code(nframes);
 310         }
 311
 312         if (!process_can_proceed()) {
 313                 _silent = true;
 314                 return;
 315         }
 316
 317         if (events.empty() || next_event == events.end()) {
 318                 process_without_events (nframes);
 319                 return;
 320         }
 321
 322         /// TODO: Figure out what happens to phi and phase, if transport speed momentarily becomes
 323         /// 1.0 eg. during the adjustments of a slave. If that is a bug, then AudioDiskstream::process
 324         /// is very likely broken too
 325         if (_transport_speed == 1.0) {
 326                 frames_moved = (long) nframes;
 327         } else {
 328                 frames_moved = (long) AudioDiskstream::
 329                         calculate_varispeed_playback_distance(nframes, phase, phi, target_phi);
 330         }
 331
 332         end_frame = _transport_frame + (nframes_t)frames_moved;
 333
 334         {
 335                 Event* this_event;
 336                 Events::iterator the_next_one;
 337
 338                 if (!process_can_proceed()) {
 339                         _silent = true;
 340                         return;
 341                 }
 342
 343                 if (!_exporting && _slave) {
 344                         if (!follow_slave (nframes, 0)) {
 345                                 return;
 346                         }
 347                 }
 348
 349                 if (_transport_speed == 0) {
 350                         no_roll (nframes, 0);
 351                         return;
 352                 }
 353
 354                 if (!_exporting) {
 355                         send_midi_time_code_for_cycle (nframes);
 356                 }
 357
 358                 if (actively_recording()) {
 359                         stop_limit = max_frames;
 360                 } else {
 361
 362                         if (Config->get_stop_at_session_end()) {
 363                                 stop_limit = current_end_frame();
 364                         } else {
 365                                 stop_limit = max_frames;
 366                         }
 367                 }
 368
 369                 if (maybe_stop (stop_limit)) {
 370                         no_roll (nframes, 0);
 371                         return;
 372                 }
 373
 374                 this_event = *next_event;
 375                 the_next_one = next_event;
 376                 ++the_next_one;
 377
 378                 offset = 0;
 379
 380                 /* yes folks, here it is, the actual loop where we really truly
 381                    process some audio */
 382                 while (nframes) {
 383
 384                         this_nframes = nframes; /* real (jack) time relative */
 385
 386                         /* running an event, position transport precisely to its time */
 387                         if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
 388                                 /* this isn't quite right for reverse play */
 389                                 frames_moved = (long) (this_event->action_frame - _transport_frame);
 390                                 this_nframes = (nframes_t) abs( floor(frames_moved / _transport_speed) );
 391                         }
 392
 393                         if (this_nframes) {
 394
 395                                 click (_transport_frame, nframes, offset);
 396
 397                                 /* now process frames between now and the first event in this block */
 398                                 prepare_diskstreams ();
 399
 400                                 if (process_routes (this_nframes, offset)) {
 401                                         no_roll (nframes, 0);
 402                                         return;
 403                                 }
 404
 405                                 commit_diskstreams (this_nframes, session_needs_butler);
 406
 407                                 nframes -= this_nframes;
 408                                 offset += this_nframes;
 409
 410                                 if (frames_moved < 0) {
 411                                         decrement_transport_position (-frames_moved);
 412                                 } else {
 413                                         increment_transport_position (frames_moved);
 414                                 }
 415
 416                                 maybe_stop (stop_limit);
 417                                 check_declick_out ();
 418                         }
 419
 420                         /* now handle this event and all others scheduled for the same time */
 421
 422                         while (this_event && this_event->action_frame == _transport_frame) {
 423                                 process_event (this_event);
 424
 425                                 if (the_next_one == events.end()) {
 426                                         this_event = 0;
 427                                 } else {
 428                                         this_event = *the_next_one;
 429                                         ++the_next_one;
 430                                 }
 431                         }
 432
 433                         /* if an event left our state changing, do the right thing */
 434
 435                         if (non_realtime_work_pending()) {
 436                                 no_roll (nframes, offset);
 437                                 break;
 438                         }
 439
 440                         /* this is necessary to handle the case of seamless looping */
 441                         end_frame = _transport_frame + (nframes_t) floor (nframes * _transport_speed);
 442
 443                 }
 444
 445                 set_next_event ();
 446
 447         } /* implicit release of route lock */
 448
 449         if (session_needs_butler)
 450                 summon_butler ();
 451 }
 452
 453 void
 454 Session::reset_slave_state ()
 455 {
 456         average_slave_delta = 1800;
 457         delta_accumulator_cnt = 0;
 458         have_first_delta_accumulator = false;
 459         slave_state = Stopped;
 460 }
 461
 462 bool
 463 Session::transport_locked () const
 464 {
 465         Slave* sl = _slave;
 466
 467         if (!locate_pending() && ((Config->get_slave_source() == None) || (sl && sl->ok() && sl->locked()))) {
 468                 return true;
 469         }
 470
 471         return false;
 472 }
 473
 474 bool
 475 Session::follow_slave (nframes_t nframes, nframes_t offset)
 476 {
 477         double slave_speed;
 478         nframes_t slave_transport_frame;
 479         nframes_t this_delta;
 480         int dir;
 481         bool starting;
 482
 483         if (!_slave->ok()) {
 484                 stop_transport ();
 485                 Config->set_slave_source (None);
 486                 goto noroll;
 487         }
 488
 489         _slave->speed_and_position (slave_speed, slave_transport_frame);
 490
 491         if (!_slave->locked()) {
 492                 goto noroll;
 493         }
 494
 495         if (slave_transport_frame > _transport_frame) {
 496                 this_delta = slave_transport_frame - _transport_frame;
 497                 dir = 1;
 498         } else {
 499                 this_delta = _transport_frame - slave_transport_frame;
 500                 dir = -1;
 501         }
 502
 503         if ((starting = _slave->starting())) {
 504                 slave_speed = 0.0f;
 505         }
 506
 507         if (_slave->is_always_synced() || Config->get_timecode_source_is_synced()) {
 508
 509                 /* if the TC source is synced, then we assume that its
 510                    speed is binary: 0.0 or 1.0
 511                 */
 512
 513                 if (slave_speed != 0.0f) {
 514                         slave_speed = 1.0f;
 515                 }
 516
 517         } else {
 518
 519                 /* TC source is able to drift relative to us (slave)
 520                    so we need to keep track of the drift and adjust
 521                    our speed to remain locked.
 522                 */
 523
 524                 calculate_moving_average_of_slave_delta(dir, this_delta);
 525         }
 526
 527         track_slave_state(slave_speed, slave_transport_frame, this_delta, starting);
 528
 529         if (slave_state == Running && !_slave->is_always_synced() && !Config->get_timecode_source_is_synced()) {
 530
 531                 if (_transport_speed != 0.0f) {
 532
 533                         /*
 534                            note that average_dir is +1 or -1
 535                         */
 536
 537                         float delta;
 538
 539                         #ifdef USE_MOVING_AVERAGE_OF_SLAVE
 540                                 if (average_slave_delta == 0) {
 541                                         delta = this_delta;
 542                                         delta *= dir;
 543                                 } else {
 544                                         delta = average_slave_delta;
 545                                         delta *= average_dir;
 546                                 }
 547                         #else
 548                                 delta = this_delta;
 549                                 delta *= dir;
 550                         #endif
 551
 552                         float adjusted_speed = slave_speed + (delta /  float(_current_frame_rate));
 553
 554                         if (_slave->give_slave_full_control_over_transport_speed()) {
 555                                 request_transport_speed(slave_speed);
 556                         } else {
 557                                 request_transport_speed(adjusted_speed);
 558                                 #ifdef DEBUG_SLAVES
 559                                 cerr << "adjust using " << delta
 560                                          << " towards " << adjusted_speed
 561                                          << " ratio = " << adjusted_speed / slave_speed
 562                                          << " current = " << _transport_speed
 563                                          << " slave @ " << slave_speed
 564                                          << endl;
 565                                 #endif
 566                         }
 567
 568                         if (abs(average_slave_delta) > (long) _slave->resolution()) {
 569                                 cerr << "average slave delta greater than slave resolution, going to silent motion\n";
 570                                 goto silent_motion;
 571                         }
 572                 }
 573         }
 574
 575         #ifdef DEBUG_SLAVES
 576         if (slave_speed != 0.0)
 577         cerr << "delta = " << (int) (dir * this_delta)
 578                  << " speed = " << slave_speed
 579                  << " ts = " << _transport_speed
 580                  << " M@ "<< slave_transport_frame << " S@ " << _transport_frame
 581                  << " avgdelta = " << average_slave_delta
 582                  << endl;
 583         #endif
 584
 585         if (!starting && !non_realtime_work_pending()) {
 586                 /* speed is set, we're locked, and good to go */
 587                 return true;
 588         }
 589
 590   silent_motion:
 591         #ifdef DEBUG_SLAVES
 592         cerr << "reached silent_motion:" <<endl;
 593         #endif
 594
 595         follow_slave_silently(nframes, offset, slave_speed);
 596
 597   noroll:
 598         /* don't move at all */
 599         #ifdef DEBUG_SLAVES
 600         cerr << "reached no_roll:" <<endl;
 601         #endif
 602         no_roll (nframes, 0);
 603         return false;
 604 }
 605
 606 void
 607 Session::calculate_moving_average_of_slave_delta(int dir, nframes_t this_delta)
 608 {
 609         if (delta_accumulator_cnt >= delta_accumulator_size) {
 610                 have_first_delta_accumulator = true;
 611                 delta_accumulator_cnt = 0;
 612         }
 613
 614         if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 615                 delta_accumulator[delta_accumulator_cnt++] = long(dir) * long(this_delta);
 616         }
 617
 618         if (have_first_delta_accumulator) {
 619                 average_slave_delta = 0L;
 620                 for (int i = 0; i < delta_accumulator_size; ++i) {
 621                         average_slave_delta += delta_accumulator[i];
 622                 }
 623                 average_slave_delta /= long(delta_accumulator_size);
 624                 if (average_slave_delta < 0L) {
 625                         average_dir = -1;
 626                         average_slave_delta = abs(average_slave_delta);
 627                 } else {
 628                         average_dir = 1;
 629                 }
 630         }
 631 }
 632
 633 void
 634 Session::track_slave_state(
 635                 float slave_speed,
 636                 nframes_t slave_transport_frame,
 637                 nframes_t this_delta,
 638                 bool starting)
 639 {
 640         if (slave_speed != 0.0f) {
 641
 642                 /* slave is running */
 643
 644                 switch (slave_state) {
 645                 case Stopped:
 646                         if (_slave->requires_seekahead()) {
 647                                 slave_wait_end = slave_transport_frame + _current_frame_rate;
 648                                 locate (slave_wait_end, false, false);
 649                                 slave_state = Waiting;
 650                                 starting = true;
 651
 652                         } else {
 653
 654                                 slave_state = Running;
 655
 656                                 Location* al = _locations.auto_loop_location();
 657
 658                                 if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 659                                         // cancel looping
 660                                         request_play_loop(false);
 661                                 }
 662
 663                                 if (slave_transport_frame != _transport_frame) {
 664                                         locate (slave_transport_frame, false, false);
 665                                 }
 666                         }
 667                         break;
 668
 669                 case Waiting:
 670                         break;
 671
 672                 default:
 673                         break;
 674
 675                 }
 676
 677                 if (slave_state == Waiting) {
 678
 679                 #ifdef DEBUG_SLAVES
 680                         cerr << "waiting at " << slave_transport_frame << endl;
 681                 #endif
 682                         if (slave_transport_frame >= slave_wait_end) {
 683 #ifdef DEBUG_SLAVES
 684                                 cerr << "\tstart at " << _transport_frame << endl;
 685 #endif
 686                                 slave_state = Running;
 687
 688                                 bool ok = true;
 689                                 nframes_t frame_delta = slave_transport_frame - _transport_frame;
 690
 691                                 boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 692
 693                                 for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 694                                         if (!(*i)->can_internal_playback_seek (frame_delta)) {
 695                                                 ok = false;
 696                                                 break;
 697                                         }
 698                                 }
 699
 700                                 if (ok) {
 701                                         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 702                                                 (*i)->internal_playback_seek (frame_delta);
 703                                         }
 704                                         _transport_frame += frame_delta;
 705
 706                                 } else {
 707                                         cerr << "cannot micro-seek\n";
 708                                         /* XXX what? */
 709                                 }
 710
 711                                 memset (delta_accumulator, 0, sizeof (long) * delta_accumulator_size);
 712                                 average_slave_delta = 0L;
 713                                 this_delta = 0;
 714                         }
 715                 }
 716
 717                 if (slave_state == Running && _transport_speed == 0.0f) {
 718
 719         #ifdef DEBUG_SLAVES
 720                         cerr << "slave starts transport\n";
 721         #endif
 722                         start_transport ();
 723                 }
 724
 725         } else { // slave_speed is 0
 726
 727                 /* slave has stopped */
 728
 729                 if (_transport_speed != 0.0f) {
 730
 731          #ifdef DEBUG_SLAVES
 732                         cerr << "slave stops transport: " << slave_speed << " frame: " << slave_transport_frame
 733                              << " tf = " << _transport_frame << endl;
 734          #endif
 735
 736                         stop_transport();
 737                 }
 738
 739                 if (slave_transport_frame != _transport_frame) {
 740         #ifdef DEBUG_SLAVES
 741                         cerr << "slave stopped, move to " << slave_transport_frame << endl;
 742         #endif
 743                         force_locate (slave_transport_frame, false);
 744                 }
 745
 746                 slave_state = Stopped;
 747         }
 748 }
 749
 750 void
 751 Session::follow_slave_silently(nframes_t nframes, nframes_t offset, float slave_speed)
 752 {
 753         if (slave_speed && _transport_speed) {
 754
 755                 /* something isn't right, but we should move with the master
 756                    for now.
 757                 */
 758
 759                 bool need_butler;
 760
 761                 prepare_diskstreams ();
 762                 silent_process_routes (nframes, offset);
 763                 commit_diskstreams (nframes, need_butler);
 764
 765                 if (need_butler) {
 766                         summon_butler ();
 767                 }
 768
 769                 int32_t frames_moved = (int32_t) floor (_transport_speed * nframes);
 770
 771                 if (frames_moved < 0) {
 772                         decrement_transport_position (-frames_moved);
 773                 } else {
 774                         increment_transport_position (frames_moved);
 775                 }
 776
 777                 nframes_t stop_limit;
 778
 779                 if (actively_recording()) {
 780                         stop_limit = max_frames;
 781                 } else {
 782                         if (Config->get_stop_at_session_end()) {
 783                                 stop_limit = current_end_frame();
 784                         } else {
 785                                 stop_limit = max_frames;
 786                         }
 787                 }
 788
 789                 maybe_stop (stop_limit);
 790         }
 791 }
 792
 793 void
 794 Session::process_without_events (nframes_t nframes)
 795 {
 796         bool session_needs_butler = false;
 797         nframes_t stop_limit;
 798         long frames_moved;
 799         nframes_t offset = 0;
 800
 801         if (!process_can_proceed()) {
 802                 _silent = true;
 803                 return;
 804         }
 805
 806         if (!_exporting && _slave) {
 807                 if (!follow_slave (nframes, 0)) {
 808                         return;
 809                 }
 810         }
 811
 812         if (_transport_speed == 0) {
 813                 no_roll (nframes, 0);
 814                 return;
 815         }
 816
 817         if (!_exporting) {
 818                 send_midi_time_code_for_cycle (nframes);
 819         }
 820
 821         if (actively_recording()) {
 822                 stop_limit = max_frames;
 823         } else {
 824                 if (Config->get_stop_at_session_end()) {
 825                         stop_limit = current_end_frame();
 826                 } else {
 827                         stop_limit = max_frames;
 828                 }
 829         }
 830
 831         if (maybe_stop (stop_limit)) {
 832                 no_roll (nframes, 0);
 833                 return;
 834         }
 835
 836         if (maybe_sync_start (nframes, offset)) {
 837                 return;
 838         }
 839
 840         click (_transport_frame, nframes, offset);
 841
 842         prepare_diskstreams ();
 843
 844         /// TODO: Figure out what happens to phi and phase, if transport speed momentarily becomes
 845         /// 1.0 eg. during the adjustments of a slave. If that is a bug, then AudioDiskstream::process
 846         /// is very likely broken too
 847         if (_transport_speed == 1.0) {
 848                 frames_moved = (long) nframes;
 849         } else {
 850                 frames_moved = (long) AudioDiskstream::
 851                         calculate_varispeed_playback_distance(nframes, phase, phi, target_phi);
 852         }
 853
 854         if (process_routes (nframes, offset)) {
 855                 no_roll (nframes, offset);
 856                 return;
 857         }
 858
 859         commit_diskstreams (nframes, session_needs_butler);
 860
 861         if (frames_moved < 0) {
 862                 decrement_transport_position (-frames_moved);
 863         } else {
 864                 increment_transport_position (frames_moved);
 865         }
 866
 867         maybe_stop (stop_limit);
 868         check_declick_out ();
 869
 870         if (session_needs_butler)
 871                 summon_butler ();
 872 }
 873
 874 /** Process callback used when the auditioner is active.
 875  * @param nframes number of frames to process.
 876  */
 877 void
 878 Session::process_audition (nframes_t nframes)
 879 {
 880         Event* ev;
 881         boost::shared_ptr<RouteList> r = routes.reader ();
 882
 883         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 884                 if (!(*i)->is_hidden()) {
 885                         (*i)->silence (nframes, 0);
 886                 }
 887         }
 888
 889         /* run the auditioner, and if it says we need butler service, ask for it */
 890
 891         if (auditioner->play_audition (nframes) > 0) {
 892                 summon_butler ();
 893         }
 894
 895         /* handle pending events */
 896
 897         while (pending_events.read (&ev, 1) == 1) {
 898                 merge_event (ev);
 899         }
 900
 901         /* if we are not in the middle of a state change,
 902            and there are immediate events queued up,
 903            process them.
 904         */
 905
 906         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 907                 Event *ev = immediate_events.front ();
 908                 immediate_events.pop_front ();
 909                 process_event (ev);
 910         }
 911
 912         if (!auditioner->active()) {
 913                 /* auditioner no longer active, so go back to the normal process callback */
 914                 process_function = &Session::process_with_events;
 915         }
 916 }
 917
 918 bool
 919 Session::maybe_sync_start (nframes_t& nframes, nframes_t& offset)
 920 {
 921         nframes_t sync_offset;
 922
 923         if (!waiting_for_sync_offset) {
 924                 return false;
 925         }
 926
 927         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
 928
 929                 /* generate silence up to the sync point, then
 930                    adjust nframes + offset to reflect whatever
 931                    is left to do.
 932                 */
 933
 934                 no_roll (sync_offset, 0);
 935                 nframes -= sync_offset;
 936                 offset += sync_offset;
 937                 waiting_for_sync_offset = false;
 938
 939                 if (nframes == 0) {
 940                         return true; // done, nothing left to process
 941                 }
 942
 943         } else {
 944
 945                 /* sync offset point is not within this process()
 946                    cycle, so just generate silence. and don't bother
 947                    with any fancy stuff here, just the minimal silence.
 948                 */
 949
 950                 g_atomic_int_inc (&processing_prohibited);
 951                 no_roll (nframes, 0);
 952                 g_atomic_int_dec_and_test (&processing_prohibited);
 953
 954                 if (Config->get_locate_while_waiting_for_sync()) {
 955                         if (micro_locate (nframes)) {
 956                                 /* XXX ERROR !!! XXX */
 957                         }
 958                 }
 959
 960                 return true; // done, nothing left to process
 961         }
 962
 963         return false;
 964 }
 965