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