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 #include "pbd/enumwriter.h"
  27
  28 #include <glibmm/thread.h>
  29
  30 #include "ardour/ardour.h"
  31 #include "ardour/audio_diskstream.h"
  32 #include "ardour/audioengine.h"
  33 #include "ardour/auditioner.h"
  34 #include "ardour/butler.h"
  35 #include "ardour/debug.h"
  36 #include "ardour/process_thread.h"
  37 #include "ardour/session.h"
  38 #include "ardour/slave.h"
  39 #include "ardour/timestamps.h"
  40
  41 #include "midi++/manager.h"
  42
  43 #include "i18n.h"
  44
  45 using namespace ARDOUR;
  46 using namespace PBD;
  47 using namespace std;
  48
  49 /** Called by the audio engine when there is work to be done with JACK.
  50  * @param nframes Number of frames to process.
  51  */
  52 void
  53 Session::process (nframes_t nframes)
  54 {
  55         MIDI::Manager::instance()->cycle_start(nframes);
  56
  57         _silent = false;
  58
  59         if (processing_blocked()) {
  60                 _silent = true;
  61                 return;
  62         }
  63
  64         if (non_realtime_work_pending()) {
  65                 if (!_butler->transport_work_requested ()) {
  66                         post_transport ();
  67                 }
  68         }
  69
  70         _engine.main_thread()->get_buffers ();
  71
  72         (this->*process_function) (nframes);
  73
  74         _engine.main_thread()->drop_buffers ();
  75
  76         // the ticker is for sending time information like MidiClock
  77         nframes_t transport_frames = transport_frame();
  78         BBT_Time  transport_bbt;
  79         bbt_time(transport_frames, transport_bbt);
  80         Timecode::Time transport_timecode;
  81         timecode_time(transport_frames, transport_timecode);
  82         tick (transport_frames, transport_bbt, transport_timecode); /* EMIT SIGNAL */
  83
  84         SendFeedback (); /* EMIT SIGNAL */
  85
  86         MIDI::Manager::instance()->cycle_end();
  87 }
  88
  89 int
  90 Session::fail_roll (nframes_t nframes)
  91 {
  92         return no_roll (nframes);
  93 }
  94
  95 int
  96 Session::no_roll (nframes_t nframes)
  97 {
  98         nframes_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
  99         int ret = 0;
 100         bool declick = get_transport_declick_required();
 101         boost::shared_ptr<RouteList> r = routes.reader ();
 102
 103         if (_click_io) {
 104                 _click_io->silence (nframes);
 105         }
 106
 107         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 108
 109                 if ((*i)->is_hidden()) {
 110                         continue;
 111                 }
 112
 113                 (*i)->set_pending_declick (declick);
 114
 115                 if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending(),
 116                                    actively_recording(), declick)) {
 117                         error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
 118                         ret = -1;
 119                         break;
 120                 }
 121         }
 122
 123         return ret;
 124 }
 125
 126 int
 127 Session::process_routes (nframes_t nframes, bool& need_butler)
 128 {
 129         bool record_active;
 130         int  declick = get_transport_declick_required();
 131         bool rec_monitors = get_rec_monitors_input();
 132         boost::shared_ptr<RouteList> r = routes.reader ();
 133
 134         if (transport_sub_state & StopPendingCapture) {
 135                 /* force a declick out */
 136                 declick = -1;
 137         }
 138
 139         record_active = actively_recording(); // || (get_record_enabled() && get_punch_in());
 140
 141         const nframes_t start_frame = _transport_frame;
 142         const nframes_t end_frame = _transport_frame + (nframes_t)floor(nframes * _transport_speed);
 143
 144         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 145
 146                 int ret;
 147
 148                 if ((*i)->is_hidden()) {
 149                         continue;
 150                 }
 151
 152                 (*i)->set_pending_declick (declick);
 153
 154                 if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, record_active, rec_monitors, need_butler)) < 0) {
 155                         stop_transport ();
 156                         return -1;
 157                 }
 158         }
 159
 160         return 0;
 161 }
 162
 163 int
 164 Session::silent_process_routes (nframes_t nframes, bool& need_butler)
 165 {
 166         bool record_active = actively_recording();
 167         int  declick = get_transport_declick_required();
 168         bool rec_monitors = get_rec_monitors_input();
 169         boost::shared_ptr<RouteList> r = routes.reader ();
 170
 171         if (transport_sub_state & StopPendingCapture) {
 172                 /* force a declick out */
 173                 declick = -1;
 174         }
 175
 176         const nframes_t start_frame = _transport_frame;
 177         const nframes_t end_frame = _transport_frame + lrintf(nframes * _transport_speed);
 178
 179         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 180
 181                 int ret;
 182
 183                 if ((*i)->is_hidden()) {
 184                         continue;
 185                 }
 186
 187                 if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, record_active, rec_monitors, need_butler)) < 0) {
 188                         stop_transport ();
 189                         return -1;
 190                 }
 191         }
 192
 193         return 0;
 194 }
 195
 196 void
 197 Session::get_diskstream_statistics ()
 198 {
 199         float pworst = 1.0f;
 200         float cworst = 1.0f;
 201
 202         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 203         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 204
 205                 if ((*i)->hidden()) {
 206                         continue;
 207                 }
 208
 209                 pworst = min (pworst, (*i)->playback_buffer_load());
 210                 cworst = min (cworst, (*i)->capture_buffer_load());
 211         }
 212
 213         uint32_t pmin = g_atomic_int_get (&_playback_load);
 214         uint32_t pminold = g_atomic_int_get (&_playback_load_min);
 215         uint32_t cmin = g_atomic_int_get (&_capture_load);
 216         uint32_t cminold = g_atomic_int_get (&_capture_load_min);
 217
 218         g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 219         g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
 220         g_atomic_int_set (&_playback_load_min, min (pmin, pminold));
 221         g_atomic_int_set (&_capture_load_min, min (cmin, cminold));
 222
 223         if (actively_recording()) {
 224                 set_dirty();
 225         }
 226 }
 227
 228 /** Process callback used when the auditioner is not active */
 229 void
 230 Session::process_with_events (nframes_t nframes)
 231 {
 232         SessionEvent*         ev;
 233         nframes_t      this_nframes;
 234         nframes_t      end_frame;
 235         bool           session_needs_butler = false;
 236         nframes_t      stop_limit;
 237         long           frames_moved;
 238
 239         /* make sure the auditioner is silent */
 240
 241         if (auditioner) {
 242                 auditioner->silence (nframes);
 243         }
 244
 245         /* handle any pending events */
 246
 247         while (pending_events.read (&ev, 1) == 1) {
 248                 merge_event (ev);
 249         }
 250
 251         /* if we are not in the middle of a state change,
 252            and there are immediate events queued up,
 253            process them.
 254         */
 255
 256         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 257                 SessionEvent *ev = immediate_events.front ();
 258                 immediate_events.pop_front ();
 259                 process_event (ev);
 260         }
 261
 262         /* Events caused a transport change, send an MTC Full Frame (Timecode) message.
 263          * This is sent whether rolling or not, to give slaves an idea of ardour time
 264          * on locates (and allow slow slaves to position and prepare for rolling)
 265          */
 266         if (_send_timecode_update) {
 267                 send_full_time_code(nframes);
 268                 deliver_mmc (MIDI::MachineControl::cmdLocate, _transport_frame);
 269         }
 270
 271         if (!process_can_proceed()) {
 272                 _silent = true;
 273                 return;
 274         }
 275
 276         if (events.empty() || next_event == events.end()) {
 277                 process_without_events (nframes);
 278                 return;
 279         }
 280
 281         if (_transport_speed == 1.0) {
 282                 frames_moved = (long) nframes;
 283         } else {
 284                 interpolation.set_target_speed (fabs(_target_transport_speed));
 285                 interpolation.set_speed (fabs(_transport_speed));
 286                 frames_moved = (long) interpolation.interpolate (0, nframes, 0, 0);
 287         }
 288
 289         end_frame = _transport_frame + (nframes_t)frames_moved;
 290
 291         {
 292                 SessionEvent* this_event;
 293                 Events::iterator the_next_one;
 294
 295                 if (!process_can_proceed()) {
 296                         _silent = true;
 297                         return;
 298                 }
 299
 300                 if (!_exporting && _slave) {
 301                         if (!follow_slave (nframes)) {
 302                                 return;
 303                         }
 304                 }
 305
 306                 if (_transport_speed == 0) {
 307                         no_roll (nframes);
 308                         return;
 309                 }
 310
 311                 if (!_exporting) {
 312                         send_midi_time_code_for_cycle (nframes);
 313                 }
 314
 315                 if (actively_recording()) {
 316                         stop_limit = max_frames;
 317                 } else {
 318
 319                         if (Config->get_stop_at_session_end()) {
 320                                 stop_limit = current_end_frame();
 321                         } else {
 322                                 stop_limit = max_frames;
 323                         }
 324                 }
 325
 326                 if (maybe_stop (stop_limit)) {
 327                         no_roll (nframes);
 328                         return;
 329                 }
 330
 331                 this_event = *next_event;
 332                 the_next_one = next_event;
 333                 ++the_next_one;
 334
 335                 /* yes folks, here it is, the actual loop where we really truly
 336                    process some audio
 337                 */
 338
 339                 while (nframes) {
 340
 341                         this_nframes = nframes; /* real (jack) time relative */
 342                         frames_moved = (long) floor (_transport_speed * nframes); /* transport relative */
 343
 344                         /* running an event, position transport precisely to its time */
 345                         if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
 346                                 /* this isn't quite right for reverse play */
 347                                 frames_moved = (long) (this_event->action_frame - _transport_frame);
 348                                 this_nframes = (nframes_t) abs( floor(frames_moved / _transport_speed) );
 349                         }
 350
 351                         if (this_nframes) {
 352
 353                                 click (_transport_frame, this_nframes);
 354
 355                                 if (process_routes (this_nframes, session_needs_butler)) {
 356                                         fail_roll (nframes);
 357                                         return;
 358                                 }
 359
 360                                 nframes -= this_nframes;
 361
 362                                 if (frames_moved < 0) {
 363                                         decrement_transport_position (-frames_moved);
 364                                 } else {
 365                                         increment_transport_position (frames_moved);
 366                                 }
 367
 368                                 maybe_stop (stop_limit);
 369                                 check_declick_out ();
 370                         }
 371
 372                         _engine.split_cycle (this_nframes);
 373
 374                         /* now handle this event and all others scheduled for the same time */
 375
 376                         while (this_event && this_event->action_frame == _transport_frame) {
 377                                 process_event (this_event);
 378
 379                                 if (the_next_one == events.end()) {
 380                                         this_event = 0;
 381                                 } else {
 382                                         this_event = *the_next_one;
 383                                         ++the_next_one;
 384                                 }
 385                         }
 386
 387                         /* if an event left our state changing, do the right thing */
 388
 389                         if (nframes && non_realtime_work_pending()) {
 390                                 no_roll (nframes);
 391                                 break;
 392                         }
 393
 394                         /* this is necessary to handle the case of seamless looping */
 395                         end_frame = _transport_frame + (nframes_t) floor (nframes * _transport_speed);
 396
 397                 }
 398
 399                 set_next_event ();
 400
 401         } /* implicit release of route lock */
 402
 403         if (session_needs_butler) {
 404                 _butler->summon ();
 405         }
 406 }
 407
 408 void
 409 Session::reset_slave_state ()
 410 {
 411         average_slave_delta = 1800;
 412         delta_accumulator_cnt = 0;
 413         have_first_delta_accumulator = false;
 414         _slave_state = Stopped;
 415 }
 416
 417 bool
 418 Session::transport_locked () const
 419 {
 420         Slave* sl = _slave;
 421
 422         if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
 423                 return true;
 424         }
 425
 426         return false;
 427 }
 428
 429 bool
 430 Session::follow_slave (nframes_t nframes)
 431 {
 432         double slave_speed;
 433         nframes64_t slave_transport_frame;
 434         nframes_t this_delta;
 435         int dir;
 436
 437         if (!_slave->ok()) {
 438                 stop_transport ();
 439                 config.set_external_sync (false);
 440                 goto noroll;
 441         }
 442
 443         _slave->speed_and_position (slave_speed, slave_transport_frame);
 444
 445         DEBUG_TRACE (DEBUG::Slave, string_compose ("Slave position %1 speed %2\n", slave_transport_frame, slave_speed));
 446
 447         if (!_slave->locked()) {
 448                 DEBUG_TRACE (DEBUG::Slave, "slave not locked\n");
 449                 goto noroll;
 450         }
 451
 452         if (slave_transport_frame > _transport_frame) {
 453                 this_delta = slave_transport_frame - _transport_frame;
 454                 dir = 1;
 455         } else {
 456                 this_delta = _transport_frame - slave_transport_frame;
 457                 dir = -1;
 458         }
 459
 460         if (_slave->starting()) {
 461                 slave_speed = 0.0f;
 462         }
 463
 464         if (_slave->is_always_synced() || config.get_timecode_source_is_synced()) {
 465
 466                 /* if the TC source is synced, then we assume that its
 467                    speed is binary: 0.0 or 1.0
 468                 */
 469
 470                 if (slave_speed != 0.0f) {
 471                         slave_speed = 1.0f;
 472                 }
 473
 474         } else {
 475
 476                 /* if we are chasing and the average delta between us and the
 477                    master gets too big, we want to switch to silent
 478                    motion. so keep track of that here.
 479                 */
 480
 481                 if (_slave_state == Running) {
 482                         calculate_moving_average_of_slave_delta(dir, this_delta);
 483                 }
 484         }
 485
 486         track_slave_state (slave_speed, slave_transport_frame, this_delta);
 487
 488         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
 489                                                    _slave_state, slave_transport_frame, slave_speed, this_delta, average_slave_delta));
 490
 491
 492         if (_slave_state == Running && !_slave->is_always_synced() && !config.get_timecode_source_is_synced()) {
 493
 494                 if (_transport_speed != 0.0f) {
 495
 496                         /*
 497                            note that average_dir is +1 or -1
 498                         */
 499
 500                         float delta;
 501
 502                         if (average_slave_delta == 0) {
 503                                 delta = this_delta;
 504                                 delta *= dir;
 505                         } else {
 506                                 delta = average_slave_delta;
 507                                 delta *= average_dir;
 508                         }
 509
 510 #ifndef NDEBUG
 511                         if (slave_speed != 0.0) {
 512                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("delta = %1 speed = %2 ts = %3 M@%4 S@%5 avgdelta %6\n",
 513                                                                            (int) (dir * this_delta),
 514                                                                            slave_speed,
 515                                                                            _transport_speed,
 516                                                                            _transport_frame,
 517                                                                            slave_transport_frame,
 518                                                                            average_slave_delta));
 519                         }
 520 #endif
 521
 522                         if (_slave->give_slave_full_control_over_transport_speed()) {
 523                                 set_transport_speed (slave_speed, false, false);
 524                                 //std::cout << "set speed = " << slave_speed << "\n";
 525                         } else {
 526                                 float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_frame_rate)));
 527                                 request_transport_speed (adjusted_speed);
 528                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("adjust using %1 towards %2 ratio %3 current %4 slave @ %5\n",
 529                                                                            delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
 530                                                                            slave_speed));
 531                         }
 532
 533 #if 1
 534                         if ((nframes_t) abs(average_slave_delta) > _slave->resolution()) {
 535                                 cerr << "average slave delta greater than slave resolution (" << _slave->resolution() << "), going to silent motion\n";
 536                                 goto silent_motion;
 537                         }
 538 #endif
 539                 }
 540         }
 541
 542
 543         if (_slave_state == Running && !non_realtime_work_pending()) {
 544                 /* speed is set, we're locked, and good to go */
 545                 return true;
 546         }
 547
 548   silent_motion:
 549         DEBUG_TRACE (DEBUG::Slave, "silent motion\n")
 550         follow_slave_silently (nframes, slave_speed);
 551
 552   noroll:
 553         /* don't move at all */
 554         DEBUG_TRACE (DEBUG::Slave, "no roll\n")
 555         no_roll (nframes);
 556         return false;
 557 }
 558
 559 void
 560 Session::calculate_moving_average_of_slave_delta(int dir, nframes_t this_delta)
 561 {
 562         if (delta_accumulator_cnt >= delta_accumulator_size) {
 563                 have_first_delta_accumulator = true;
 564                 delta_accumulator_cnt = 0;
 565         }
 566
 567         if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 568                 delta_accumulator[delta_accumulator_cnt++] = long(dir) * long(this_delta);
 569         }
 570
 571         if (have_first_delta_accumulator) {
 572                 average_slave_delta = 0L;
 573                 for (int i = 0; i < delta_accumulator_size; ++i) {
 574                         average_slave_delta += delta_accumulator[i];
 575                 }
 576                 average_slave_delta /= long(delta_accumulator_size);
 577                 if (average_slave_delta < 0L) {
 578                         average_dir = -1;
 579                         average_slave_delta = abs(average_slave_delta);
 580                 } else {
 581                         average_dir = 1;
 582                 }
 583         }
 584 }
 585
 586 void
 587 Session::track_slave_state (float slave_speed, nframes_t slave_transport_frame, nframes_t this_delta)
 588 {
 589         if (slave_speed != 0.0f) {
 590
 591                 /* slave is running */
 592
 593                 switch (_slave_state) {
 594                 case Stopped:
 595                         if (_slave->requires_seekahead()) {
 596                                 slave_wait_end = slave_transport_frame + _slave->seekahead_distance ();
 597                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, but running, requires seekahead to %1\n", slave_wait_end));
 598                                 /* we can call locate() here because we are in process context */
 599                                 locate (slave_wait_end, false, false);
 600                                 _slave_state = Waiting;
 601
 602                         } else {
 603
 604                                 _slave_state = Running;
 605
 606                                 Location* al = _locations.auto_loop_location();
 607
 608                                 if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 609                                         // cancel looping
 610                                         request_play_loop(false);
 611                                 }
 612
 613                                 if (slave_transport_frame != _transport_frame) {
 614                                         locate (slave_transport_frame, false, false);
 615                                 }
 616                         }
 617                         break;
 618
 619                 case Waiting:
 620                 default:
 621                         break;
 622                 }
 623
 624                 if (_slave_state == Waiting) {
 625
 626                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave waiting at %1\n", slave_transport_frame));
 627
 628                         if (slave_transport_frame >= slave_wait_end) {
 629
 630                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave start at %1 vs %2\n", slave_transport_frame, _transport_frame));
 631
 632                                 _slave_state = Running;
 633
 634                                 /* now perform a "micro-seek" within the disk buffers to realign ourselves
 635                                    precisely with the master.
 636                                 */
 637
 638
 639                                 bool ok = true;
 640                                 nframes_t frame_delta = slave_transport_frame - _transport_frame;
 641
 642                                 boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 643
 644                                 for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 645                                         if (!(*i)->can_internal_playback_seek (frame_delta)) {
 646                                                 ok = false;
 647                                                 break;
 648                                         }
 649                                 }
 650
 651                                 if (ok) {
 652                                         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 653                                                 (*i)->internal_playback_seek (frame_delta);
 654                                         }
 655                                         _transport_frame += frame_delta;
 656
 657                                 } else {
 658                                         cerr << "cannot micro-seek\n";
 659                                         /* XXX what? */
 660                                 }
 661
 662                                 memset (delta_accumulator, 0, sizeof (long) * delta_accumulator_size);
 663                                 average_slave_delta = 0L;
 664                                 this_delta = 0;
 665                         }
 666                 }
 667
 668                 if (_slave_state == Running && _transport_speed == 0.0f) {
 669                         DEBUG_TRACE (DEBUG::Slave, "slave starts transport\n");
 670                         start_transport ();
 671                 }
 672
 673         } else { // slave_speed is 0
 674
 675                 /* slave has stopped */
 676
 677                 if (_transport_speed != 0.0f) {
 678                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 frame %2 tf %3\n", slave_speed, slave_transport_frame, _transport_frame));
 679                         stop_transport();
 680                 }
 681
 682                 if (slave_transport_frame != _transport_frame) {
 683                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, move to %1\n", slave_transport_frame));
 684                         force_locate (slave_transport_frame, false);
 685                 }
 686
 687                 _slave_state = Stopped;
 688         }
 689 }
 690
 691 void
 692 Session::follow_slave_silently (nframes_t nframes, float slave_speed)
 693 {
 694         if (slave_speed && _transport_speed) {
 695
 696                 /* something isn't right, but we should move with the master
 697                    for now.
 698                 */
 699
 700                 bool need_butler;
 701
 702                 silent_process_routes (nframes, need_butler);
 703
 704                 if (need_butler) {
 705                         _butler->summon ();
 706                 }
 707
 708                 int32_t frames_moved = (int32_t) floor (_transport_speed * nframes);
 709
 710                 if (frames_moved < 0) {
 711                         decrement_transport_position (-frames_moved);
 712                 } else {
 713                         increment_transport_position (frames_moved);
 714                 }
 715
 716                 nframes_t stop_limit;
 717
 718                 if (actively_recording()) {
 719                         stop_limit = max_frames;
 720                 } else {
 721                         if (Config->get_stop_at_session_end()) {
 722                                 stop_limit = current_end_frame();
 723                         } else {
 724                                 stop_limit = max_frames;
 725                         }
 726                 }
 727
 728                 maybe_stop (stop_limit);
 729         }
 730 }
 731
 732 void
 733 Session::process_without_events (nframes_t nframes)
 734 {
 735         bool session_needs_butler = false;
 736         nframes_t stop_limit;
 737         long frames_moved;
 738
 739         if (!process_can_proceed()) {
 740                 _silent = true;
 741                 return;
 742         }
 743
 744         if (!_exporting && _slave) {
 745                 if (!follow_slave (nframes)) {
 746                         return;
 747                 }
 748         }
 749
 750         if (_transport_speed == 0) {
 751                 fail_roll (nframes);
 752                 return;
 753         }
 754
 755         if (!_exporting) {
 756                 send_midi_time_code_for_cycle (nframes);
 757         }
 758
 759         if (actively_recording()) {
 760                 stop_limit = max_frames;
 761         } else {
 762                 if (Config->get_stop_at_session_end()) {
 763                         stop_limit = current_end_frame();
 764                 } else {
 765                         stop_limit = max_frames;
 766                 }
 767         }
 768
 769         if (maybe_stop (stop_limit)) {
 770                 fail_roll (nframes);
 771                 return;
 772         }
 773
 774         if (maybe_sync_start (nframes)) {
 775                 return;
 776         }
 777
 778         click (_transport_frame, nframes);
 779
 780         if (_transport_speed == 1.0) {
 781                 frames_moved = (long) nframes;
 782         } else {
 783                 interpolation.set_target_speed (fabs(_target_transport_speed));
 784                 interpolation.set_speed (fabs(_transport_speed));
 785                 frames_moved = (long) interpolation.interpolate (0, nframes, 0, 0);
 786         }
 787
 788         if (process_routes (nframes, session_needs_butler)) {
 789                 fail_roll (nframes);
 790                 return;
 791         }
 792
 793         if (frames_moved < 0) {
 794                 decrement_transport_position (-frames_moved);
 795         } else {
 796                 increment_transport_position (frames_moved);
 797         }
 798
 799         maybe_stop (stop_limit);
 800         check_declick_out ();
 801
 802         if (session_needs_butler) {
 803                 _butler->summon ();
 804         }
 805 }
 806
 807 /** Process callback used when the auditioner is active.
 808  * @param nframes number of frames to process.
 809  */
 810 void
 811 Session::process_audition (nframes_t nframes)
 812 {
 813         SessionEvent* ev;
 814         boost::shared_ptr<RouteList> r = routes.reader ();
 815
 816         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 817                 if (!(*i)->is_hidden()) {
 818                         (*i)->silence (nframes);
 819                 }
 820         }
 821
 822         /* run the auditioner, and if it says we need butler service, ask for it */
 823
 824         if (auditioner->play_audition (nframes) > 0) {
 825                 _butler->summon ();
 826         }
 827
 828         /* if using a monitor section, run it because otherwise we don't hear anything */
 829
 830         if (auditioner->needs_monitor()) {
 831                 _monitor_out->passthru (_transport_frame, _transport_frame + nframes, nframes, false);
 832         }
 833
 834         /* handle pending events */
 835
 836         while (pending_events.read (&ev, 1) == 1) {
 837                 merge_event (ev);
 838         }
 839
 840         /* if we are not in the middle of a state change,
 841            and there are immediate events queued up,
 842            process them.
 843         */
 844
 845         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 846                 SessionEvent *ev = immediate_events.front ();
 847                 immediate_events.pop_front ();
 848                 process_event (ev);
 849         }
 850
 851         if (!auditioner->auditioning()) {
 852                 /* auditioner no longer active, so go back to the normal process callback */
 853                 process_function = &Session::process_with_events;
 854         }
 855 }
 856
 857 bool
 858 Session::maybe_sync_start (nframes_t& nframes)
 859 {
 860         nframes_t sync_offset;
 861
 862         if (!waiting_for_sync_offset) {
 863                 return false;
 864         }
 865
 866         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
 867
 868                 /* generate silence up to the sync point, then
 869                    adjust nframes + offset to reflect whatever
 870                    is left to do.
 871                 */
 872
 873                 no_roll (sync_offset);
 874                 nframes -= sync_offset;
 875                 Port::increment_port_offset (sync_offset);
 876                 waiting_for_sync_offset = false;
 877
 878                 if (nframes == 0) {
 879                         return true; // done, nothing left to process
 880                 }
 881
 882         } else {
 883
 884                 /* sync offset point is not within this process()
 885                    cycle, so just generate silence. and don't bother
 886                    with any fancy stuff here, just the minimal silence.
 887                 */
 888
 889                 _silent = true;
 890
 891                 if (Config->get_locate_while_waiting_for_sync()) {
 892                         if (micro_locate (nframes)) {
 893                                 /* XXX ERROR !!! XXX */
 894                         }
 895                 }
 896
 897                 return true; // done, nothing left to process
 898         }
 899
 900         return false;
 901 }
 902
 903 void
 904 Session::queue_event (SessionEvent* ev)
 905 {
 906         if (_state_of_the_state & Deletion) {
 907                 return;
 908         } else if (_state_of_the_state & Loading) {
 909                 merge_event (ev);
 910         } else {
 911                 pending_events.write (&ev, 1);
 912         }
 913 }
 914
 915 void
 916 Session::set_next_event ()
 917 {
 918         if (events.empty()) {
 919                 next_event = events.end();
 920                 return;
 921         }
 922
 923         if (next_event == events.end()) {
 924                 next_event = events.begin();
 925         }
 926
 927         if ((*next_event)->action_frame > _transport_frame) {
 928                 next_event = events.begin();
 929         }
 930
 931         for (; next_event != events.end(); ++next_event) {
 932                 if ((*next_event)->action_frame >= _transport_frame) {
 933                         break;
 934                 }
 935         }
 936 }
 937
 938 void
 939 Session::process_event (SessionEvent* ev)
 940 {
 941         bool remove = true;
 942         bool del = true;
 943
 944         /* if we're in the middle of a state change (i.e. waiting
 945            for the butler thread to complete the non-realtime
 946            part of the change), we'll just have to queue this
 947            event for a time when the change is complete.
 948         */
 949
 950         if (non_realtime_work_pending()) {
 951
 952                 /* except locates, which we have the capability to handle */
 953
 954                 if (ev->type != SessionEvent::Locate) {
 955                         immediate_events.insert (immediate_events.end(), ev);
 956                         _remove_event (ev);
 957                         return;
 958                 }
 959         }
 960
 961         DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("Processing event: %1 @ %2\n", enum_2_string (ev->type), _transport_frame));
 962
 963         switch (ev->type) {
 964         case SessionEvent::SetLoop:
 965                 set_play_loop (ev->yes_or_no);
 966                 break;
 967
 968         case SessionEvent::AutoLoop:
 969                 if (play_loop) {
 970                         start_locate (ev->target_frame, true, false, Config->get_seamless_loop());
 971                 }
 972                 remove = false;
 973                 del = false;
 974                 break;
 975
 976         case SessionEvent::Locate:
 977                 if (ev->yes_or_no) {
 978                         // cerr << "forced locate to " << ev->target_frame << endl;
 979                         locate (ev->target_frame, false, true, false);
 980                 } else {
 981                         // cerr << "soft locate to " << ev->target_frame << endl;
 982                         start_locate (ev->target_frame, false, true, false);
 983                 }
 984                 _send_timecode_update = true;
 985                 break;
 986
 987         case SessionEvent::LocateRoll:
 988                 if (ev->yes_or_no) {
 989                         // cerr << "forced locate to+roll " << ev->target_frame << endl;
 990                         locate (ev->target_frame, true, true, false);
 991                 } else {
 992                         // cerr << "soft locate to+roll " << ev->target_frame << endl;
 993                         start_locate (ev->target_frame, true, true, false);
 994                 }
 995                 _send_timecode_update = true;
 996                 break;
 997
 998         case SessionEvent::LocateRollLocate:
 999                 // locate is handled by ::request_roll_at_and_return()
1000                 _requested_return_frame = ev->target_frame;
1001                 request_locate (ev->target2_frame, true);
1002                 break;
1003
1004
1005         case SessionEvent::SetTransportSpeed:
1006                 set_transport_speed (ev->speed, ev->yes_or_no, ev->second_yes_or_no);
1007                 break;
1008
1009         case SessionEvent::PunchIn:
1010                 // cerr << "PunchIN at " << transport_frame() << endl;
1011                 if (config.get_punch_in() && record_status() == Enabled) {
1012                         enable_record ();
1013                 }
1014                 remove = false;
1015                 del = false;
1016                 break;
1017
1018         case SessionEvent::PunchOut:
1019                 // cerr << "PunchOUT at " << transport_frame() << endl;
1020                 if (config.get_punch_out()) {
1021                         step_back_from_record ();
1022                 }
1023                 remove = false;
1024                 del = false;
1025                 break;
1026
1027         case SessionEvent::StopOnce:
1028                 if (!non_realtime_work_pending()) {
1029                         stop_transport (ev->yes_or_no);
1030                         _clear_event_type (SessionEvent::StopOnce);
1031                 }
1032                 remove = false;
1033                 del = false;
1034                 break;
1035
1036         case SessionEvent::RangeStop:
1037                 if (!non_realtime_work_pending()) {
1038                         stop_transport (ev->yes_or_no);
1039                 }
1040                 remove = false;
1041                 del = false;
1042                 break;
1043
1044         case SessionEvent::RangeLocate:
1045                 start_locate (ev->target_frame, true, true, false);
1046                 remove = false;
1047                 del = false;
1048                 break;
1049
1050         case SessionEvent::Overwrite:
1051                 overwrite_some_buffers (static_cast<Diskstream*>(ev->ptr));
1052                 break;
1053
1054         case SessionEvent::SetDiskstreamSpeed:
1055                 set_diskstream_speed (static_cast<Diskstream*> (ev->ptr), ev->speed);
1056                 break;
1057
1058         case SessionEvent::SetSyncSource:
1059                 use_sync_source (ev->slave);
1060                 break;
1061
1062         case SessionEvent::Audition:
1063                 set_audition (ev->region);
1064                 // drop reference to region
1065                 ev->region.reset ();
1066                 break;
1067
1068         case SessionEvent::InputConfigurationChange:
1069                 add_post_transport_work (PostTransportInputChange);
1070                 _butler->schedule_transport_work ();
1071                 break;
1072
1073         case SessionEvent::SetPlayAudioRange:
1074                 set_play_range (ev->audio_range, (ev->speed == 1.0f));
1075                 break;
1076
1077         case SessionEvent::RealTimeOperation:
1078                 process_rtop (ev);
1079                 del = false; // other side of RT request needs to clean up
1080                 break;
1081
1082         default:
1083           fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
1084                 /*NOTREACHED*/
1085                 break;
1086         };
1087
1088         if (remove) {
1089                 del = del && !_remove_event (ev);
1090         }
1091
1092         if (del) {
1093                 delete ev;
1094         }
1095 }
1096