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