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/audioengine.h"
  32 #include "ardour/auditioner.h"
  33 #include "ardour/butler.h"
  34 #include "ardour/debug.h"
  35 #include "ardour/process_thread.h"
  36 #include "ardour/session.h"
  37 #include "ardour/slave.h"
  38 #include "ardour/timestamps.h"
  39 #include "ardour/graph.h"
  40 #include "ardour/audio_port.h"
  41 #include "ardour/tempo.h"
  42 #include "ardour/ticker.h"
  43 #include "ardour/cycle_timer.h"
  44
  45 #include "midi++/manager.h"
  46 #include "midi++/mmc.h"
  47
  48 #include "i18n.h"
  49
  50 using namespace ARDOUR;
  51 using namespace PBD;
  52 using namespace std;
  53
  54 /** Called by the audio engine when there is work to be done with JACK.
  55  * @param nframes Number of frames to process.
  56  */
  57
  58 void
  59 Session::process (pframes_t nframes)
  60 {
  61         framepos_t transport_at_start = _transport_frame;
  62
  63         MIDI::Manager::instance()->cycle_start(nframes);
  64
  65         _silent = false;
  66
  67         if (processing_blocked()) {
  68                 _silent = true;
  69                 return;
  70         }
  71
  72         if (non_realtime_work_pending()) {
  73                 if (!_butler->transport_work_requested ()) {
  74                         post_transport ();
  75                 }
  76         }
  77
  78         _engine.main_thread()->get_buffers ();
  79
  80         (this->*process_function) (nframes);
  81
  82         _engine.main_thread()->drop_buffers ();
  83
  84         /* deliver MIDI clock. Note that we need to use the transport frame
  85          * position at the start of process(), not the value at the end of
  86          * it. We may already have ticked() because of a transport state
  87          * change, for example.
  88          */
  89
  90         try {
  91                 if (!_engine.freewheeling() && Config->get_send_midi_clock() && transport_speed() == 1.0f && midi_clock->has_midi_port()) {
  92                         midi_clock->tick (transport_at_start);
  93                 }
  94         } catch (...) {
  95                 /* don't bother with a message */
  96         }
  97
  98         SendFeedback (); /* EMIT SIGNAL */
  99
 100         MIDI::Manager::instance()->cycle_end();
 101 }
 102
 103 int
 104 Session::fail_roll (pframes_t nframes)
 105 {
 106         return no_roll (nframes);
 107 }
 108
 109 int
 110 Session::no_roll (pframes_t nframes)
 111 {
 112         PT_TIMING_CHECK (4);
 113
 114         framepos_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
 115         int ret = 0;
 116         bool declick = get_transport_declick_required();
 117         boost::shared_ptr<RouteList> r = routes.reader ();
 118
 119         if (_click_io) {
 120                 _click_io->silence (nframes);
 121         }
 122
 123         if (_process_graph) {
 124                 DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/no-roll\n");
 125                 _process_graph->routes_no_roll( nframes, _transport_frame, end_frame, non_realtime_work_pending(), declick);
 126         } else {
 127                 PT_TIMING_CHECK (10);
 128                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 129
 130                         if ((*i)->is_hidden()) {
 131                                 continue;
 132                         }
 133
 134                         (*i)->set_pending_declick (declick);
 135
 136                         if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending())) {
 137                                 error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
 138                                 ret = -1;
 139                                 break;
 140                         }
 141                 }
 142                 PT_TIMING_CHECK (11);
 143         }
 144
 145         PT_TIMING_CHECK (5);
 146         return ret;
 147 }
 148
 149 /** @param need_butler to be set to true by this method if it needs the butler,
 150  *  otherwise it must be left alone.
 151  */
 152 int
 153 Session::process_routes (pframes_t nframes, bool& need_butler)
 154 {
 155         int  declick = get_transport_declick_required();
 156         boost::shared_ptr<RouteList> r = routes.reader ();
 157
 158         if (transport_sub_state & StopPendingCapture) {
 159                 /* force a declick out */
 160                 declick = -1;
 161         }
 162
 163         const framepos_t start_frame = _transport_frame;
 164         const framepos_t end_frame = _transport_frame + floor (nframes * _transport_speed);
 165
 166         if (_process_graph) {
 167                 DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/process-routes\n");
 168                 _process_graph->process_routes (nframes, start_frame, end_frame, declick, need_butler);
 169         } else {
 170
 171                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 172
 173                         int ret;
 174
 175                         if ((*i)->is_hidden()) {
 176                                 continue;
 177                         }
 178
 179                         (*i)->set_pending_declick (declick);
 180
 181                         bool b = false;
 182
 183                         if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, b)) < 0) {
 184                                 stop_transport ();
 185                                 return -1;
 186                         }
 187
 188                         if (b) {
 189                                 need_butler = true;
 190                         }
 191                 }
 192         }
 193
 194         return 0;
 195 }
 196
 197 /** @param need_butler to be set to true by this method if it needs the butler,
 198  *  otherwise it must be left alone.
 199  */
 200 int
 201 Session::silent_process_routes (pframes_t nframes, bool& need_butler)
 202 {
 203         boost::shared_ptr<RouteList> r = routes.reader ();
 204
 205         const framepos_t start_frame = _transport_frame;
 206         const framepos_t end_frame = _transport_frame + lrintf(nframes * _transport_speed);
 207
 208         if (_process_graph) {
 209                 _process_graph->silent_process_routes (nframes, start_frame, end_frame, need_butler);
 210         } else {
 211                 for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 212
 213                         int ret;
 214
 215                         if ((*i)->is_hidden()) {
 216                                 continue;
 217                         }
 218
 219                         bool b = false;
 220
 221                         if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, b)) < 0) {
 222                                 stop_transport ();
 223                                 return -1;
 224                         }
 225
 226                         if (b) {
 227                                 need_butler = true;
 228                         }
 229                 }
 230         }
 231
 232         return 0;
 233 }
 234
 235 void
 236 Session::get_track_statistics ()
 237 {
 238         float pworst = 1.0f;
 239         float cworst = 1.0f;
 240
 241         boost::shared_ptr<RouteList> rl = routes.reader();
 242         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 243
 244                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 245
 246                 if (!tr || tr->hidden()) {
 247                         continue;
 248                 }
 249
 250                 pworst = min (pworst, tr->playback_buffer_load());
 251                 cworst = min (cworst, tr->capture_buffer_load());
 252         }
 253
 254         g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 255         g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
 256
 257         if (actively_recording()) {
 258                 set_dirty();
 259         }
 260 }
 261
 262 /** Process callback used when the auditioner is not active */
 263 void
 264 Session::process_with_events (pframes_t nframes)
 265 {
 266         PT_TIMING_CHECK (3);
 267
 268         SessionEvent*  ev;
 269         pframes_t      this_nframes;
 270         framepos_t     end_frame;
 271         bool           session_needs_butler = false;
 272         framecnt_t     frames_moved;
 273
 274         /* make sure the auditioner is silent */
 275
 276         if (auditioner) {
 277                 auditioner->silence (nframes);
 278         }
 279
 280         /* handle any pending events */
 281
 282         while (pending_events.read (&ev, 1) == 1) {
 283                 merge_event (ev);
 284         }
 285
 286         /* if we are not in the middle of a state change,
 287            and there are immediate events queued up,
 288            process them.
 289         */
 290
 291         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 292                 SessionEvent *ev = immediate_events.front ();
 293                 immediate_events.pop_front ();
 294                 process_event (ev);
 295         }
 296
 297         /* Decide on what to do with quarter-frame MTC during this cycle */
 298
 299         bool const was_sending_qf_mtc = _send_qf_mtc;
 300         double const tolerance = Config->get_mtc_qf_speed_tolerance() / 100.0;
 301
 302         if (_transport_speed != 0) {
 303                 _send_qf_mtc = (
 304                         Config->get_send_mtc () &&
 305                         _transport_speed >= (1 - tolerance) &&
 306                         _transport_speed <= (1 + tolerance)
 307                         );
 308
 309                 if (_send_qf_mtc && !was_sending_qf_mtc) {
 310                         /* we will re-start quarter-frame MTC this cycle, so send a full update to set things up */
 311                         _send_timecode_update = true;
 312                 }
 313
 314                 if (Config->get_send_mtc() && !_send_qf_mtc && _pframes_since_last_mtc > (frame_rate () / 4)) {
 315                         /* we're sending MTC, but we're not sending QF MTC at the moment, and it's been
 316                            a quarter of a second since we sent anything at all, so send a full MTC update
 317                            this cycle.
 318                         */
 319                         _send_timecode_update = true;
 320                 }
 321
 322                 _pframes_since_last_mtc += nframes;
 323         }
 324
 325         /* Events caused a transport change (or we re-started sending
 326          * MTC), so send an MTC Full Frame (Timecode) message.  This
 327          * is sent whether rolling or not, to give slaves an idea of
 328          * ardour time on locates (and allow slow slaves to position
 329          * and prepare for rolling)
 330          */
 331         if (_send_timecode_update) {
 332                 send_full_time_code (_transport_frame);
 333         }
 334
 335         if (!process_can_proceed()) {
 336                 _silent = true;
 337                 return;
 338         }
 339
 340         if (events.empty() || next_event == events.end()) {
 341                 process_without_events (nframes);
 342                 return;
 343         }
 344
 345         if (_transport_speed == 1.0) {
 346                 frames_moved = (framecnt_t) nframes;
 347         } else {
 348                 interpolation.set_target_speed (fabs(_target_transport_speed));
 349                 interpolation.set_speed (fabs(_transport_speed));
 350                 frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 351         }
 352
 353         end_frame = _transport_frame + frames_moved;
 354
 355         {
 356                 SessionEvent* this_event;
 357                 Events::iterator the_next_one;
 358
 359                 if (!process_can_proceed()) {
 360                         _silent = true;
 361                         return;
 362                 }
 363
 364                 if (!_exporting && _slave) {
 365                         if (!follow_slave (nframes)) {
 366                                 return;
 367                         }
 368                 }
 369
 370                 if (_transport_speed == 0) {
 371                         no_roll (nframes);
 372                         return;
 373                 }
 374
 375                 if (!_exporting && !timecode_transmission_suspended()) {
 376                         send_midi_time_code_for_cycle (_transport_frame, end_frame, nframes);
 377                 }
 378
 379                 framepos_t stop_limit = compute_stop_limit ();
 380
 381                 if (maybe_stop (stop_limit)) {
 382                         no_roll (nframes);
 383                         return;
 384                 }
 385
 386                 this_event = *next_event;
 387                 the_next_one = next_event;
 388                 ++the_next_one;
 389
 390                 /* yes folks, here it is, the actual loop where we really truly
 391                    process some audio
 392                 */
 393
 394                 while (nframes) {
 395
 396                         this_nframes = nframes; /* real (jack) time relative */
 397                         frames_moved = (framecnt_t) floor (_transport_speed * nframes); /* transport relative */
 398
 399                         /* running an event, position transport precisely to its time */
 400                         if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
 401                                 /* this isn't quite right for reverse play */
 402                                 frames_moved = (framecnt_t) (this_event->action_frame - _transport_frame);
 403                                 this_nframes = abs (floor(frames_moved / _transport_speed));
 404                         }
 405
 406                         if (this_nframes) {
 407
 408                                 click (_transport_frame, this_nframes);
 409
 410                                 if (process_routes (this_nframes, session_needs_butler)) {
 411                                         fail_roll (nframes);
 412                                         return;
 413                                 }
 414
 415                                 get_track_statistics ();
 416
 417                                 nframes -= this_nframes;
 418
 419                                 if (frames_moved < 0) {
 420                                         decrement_transport_position (-frames_moved);
 421                                 } else {
 422                                         increment_transport_position (frames_moved);
 423                                 }
 424
 425                                 maybe_stop (stop_limit);
 426                                 check_declick_out ();
 427                         }
 428
 429                         _engine.split_cycle (this_nframes);
 430
 431                         /* now handle this event and all others scheduled for the same time */
 432
 433                         while (this_event && this_event->action_frame == _transport_frame) {
 434                                 process_event (this_event);
 435
 436                                 if (the_next_one == events.end()) {
 437                                         this_event = 0;
 438                                 } else {
 439                                         this_event = *the_next_one;
 440                                         ++the_next_one;
 441                                 }
 442                         }
 443
 444                         /* if an event left our state changing, do the right thing */
 445
 446                         if (nframes && non_realtime_work_pending()) {
 447                                 no_roll (nframes);
 448                                 break;
 449                         }
 450
 451                         /* this is necessary to handle the case of seamless looping */
 452                         end_frame = _transport_frame + floor (nframes * _transport_speed);
 453                 }
 454
 455                 set_next_event ();
 456
 457         } /* implicit release of route lock */
 458
 459         if (session_needs_butler) {
 460                 _butler->summon ();
 461         }
 462 }
 463
 464 void
 465 Session::reset_slave_state ()
 466 {
 467         average_slave_delta = 1800;
 468         delta_accumulator_cnt = 0;
 469         have_first_delta_accumulator = false;
 470         _slave_state = Stopped;
 471 }
 472
 473 bool
 474 Session::transport_locked () const
 475 {
 476         Slave* sl = _slave;
 477
 478         if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
 479                 return true;
 480         }
 481
 482         return false;
 483 }
 484
 485 bool
 486 Session::follow_slave (pframes_t nframes)
 487 {
 488         double slave_speed;
 489         framepos_t slave_transport_frame;
 490         framecnt_t this_delta;
 491         int dir;
 492
 493         if (!_slave->ok()) {
 494                 stop_transport ();
 495                 config.set_external_sync (false);
 496                 goto noroll;
 497         }
 498
 499         _slave->speed_and_position (slave_speed, slave_transport_frame);
 500
 501         DEBUG_TRACE (DEBUG::Slave, string_compose ("Slave position %1 speed %2\n", slave_transport_frame, slave_speed));
 502
 503         if (!_slave->locked()) {
 504                 DEBUG_TRACE (DEBUG::Slave, "slave not locked\n");
 505                 goto noroll;
 506         }
 507
 508         if (slave_transport_frame > _transport_frame) {
 509                 this_delta = slave_transport_frame - _transport_frame;
 510                 dir = 1;
 511         } else {
 512                 this_delta = _transport_frame - slave_transport_frame;
 513                 dir = -1;
 514         }
 515
 516         if (_slave->starting()) {
 517                 slave_speed = 0.0f;
 518         }
 519
 520         if (_slave->is_always_synced() || config.get_timecode_source_is_synced()) {
 521
 522                 /* if the TC source is synced, then we assume that its
 523                    speed is binary: 0.0 or 1.0
 524                 */
 525
 526                 if (slave_speed != 0.0f) {
 527                         slave_speed = 1.0f;
 528                 }
 529
 530         } else {
 531
 532                 /* if we are chasing and the average delta between us and the
 533                    master gets too big, we want to switch to silent
 534                    motion. so keep track of that here.
 535                 */
 536
 537                 if (_slave_state == Running) {
 538                         calculate_moving_average_of_slave_delta(dir, this_delta);
 539                 }
 540         }
 541
 542         track_slave_state (slave_speed, slave_transport_frame, this_delta);
 543
 544         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
 545                                                    _slave_state, slave_transport_frame, slave_speed, this_delta, average_slave_delta));
 546
 547
 548         if (_slave_state == Running && !_slave->is_always_synced() && !config.get_timecode_source_is_synced()) {
 549
 550                 if (_transport_speed != 0.0f) {
 551
 552                         /*
 553                            note that average_dir is +1 or -1
 554                         */
 555
 556                         float delta;
 557
 558                         if (average_slave_delta == 0) {
 559                                 delta = this_delta;
 560                                 delta *= dir;
 561                         } else {
 562                                 delta = average_slave_delta;
 563                                 delta *= average_dir;
 564                         }
 565
 566 #ifndef NDEBUG
 567                         if (slave_speed != 0.0) {
 568                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("delta = %1 speed = %2 ts = %3 M@%4 S@%5 avgdelta %6\n",
 569                                                                            (int) (dir * this_delta),
 570                                                                            slave_speed,
 571                                                                            _transport_speed,
 572                                                                            _transport_frame,
 573                                                                            slave_transport_frame,
 574                                                                            average_slave_delta));
 575                         }
 576 #endif
 577
 578                         if (_slave->give_slave_full_control_over_transport_speed()) {
 579                                 set_transport_speed (slave_speed, false, false);
 580                                 //std::cout << "set speed = " << slave_speed << "\n";
 581                         } else {
 582                                 float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_frame_rate)));
 583                                 request_transport_speed (adjusted_speed);
 584                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("adjust using %1 towards %2 ratio %3 current %4 slave @ %5\n",
 585                                                                            delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
 586                                                                            slave_speed));
 587                         }
 588
 589 #if 1
 590                         if ((framecnt_t) abs(average_slave_delta) > _slave->resolution()) {
 591                                 cerr << "average slave delta greater than slave resolution (" << _slave->resolution() << "), going to silent motion\n";
 592                                 goto silent_motion;
 593                         }
 594 #endif
 595                 }
 596         }
 597
 598
 599         if (_slave_state == Running && !non_realtime_work_pending()) {
 600                 /* speed is set, we're locked, and good to go */
 601                 return true;
 602         }
 603
 604   silent_motion:
 605         DEBUG_TRACE (DEBUG::Slave, "silent motion\n")
 606         follow_slave_silently (nframes, slave_speed);
 607
 608   noroll:
 609         /* don't move at all */
 610         DEBUG_TRACE (DEBUG::Slave, "no roll\n")
 611         no_roll (nframes);
 612         return false;
 613 }
 614
 615 void
 616 Session::calculate_moving_average_of_slave_delta (int dir, framecnt_t this_delta)
 617 {
 618         if (delta_accumulator_cnt >= delta_accumulator_size) {
 619                 have_first_delta_accumulator = true;
 620                 delta_accumulator_cnt = 0;
 621         }
 622
 623         if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 624                 delta_accumulator[delta_accumulator_cnt++] = (framecnt_t) dir *  (framecnt_t) this_delta;
 625         }
 626
 627         if (have_first_delta_accumulator) {
 628                 average_slave_delta = 0L;
 629                 for (int i = 0; i < delta_accumulator_size; ++i) {
 630                         average_slave_delta += delta_accumulator[i];
 631                 }
 632                 average_slave_delta /= (int32_t) delta_accumulator_size;
 633                 if (average_slave_delta < 0L) {
 634                         average_dir = -1;
 635                         average_slave_delta = abs(average_slave_delta);
 636                 } else {
 637                         average_dir = 1;
 638                 }
 639         }
 640 }
 641
 642 void
 643 Session::track_slave_state (float slave_speed, framepos_t slave_transport_frame, framecnt_t /*this_delta*/)
 644 {
 645         if (slave_speed != 0.0f) {
 646
 647                 /* slave is running */
 648
 649                 switch (_slave_state) {
 650                 case Stopped:
 651                         if (_slave->requires_seekahead()) {
 652                                 slave_wait_end = slave_transport_frame + _slave->seekahead_distance ();
 653                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, but running, requires seekahead to %1\n", slave_wait_end));
 654                                 /* we can call locate() here because we are in process context */
 655                                 locate (slave_wait_end, false, false);
 656                                 _slave_state = Waiting;
 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                 default:
 677                         break;
 678                 }
 679
 680                 if (_slave_state == Waiting) {
 681
 682                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave waiting at %1\n", slave_transport_frame));
 683
 684                         if (slave_transport_frame >= slave_wait_end) {
 685
 686                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave start at %1 vs %2\n", slave_transport_frame, _transport_frame));
 687
 688                                 _slave_state = Running;
 689
 690                                 /* now perform a "micro-seek" within the disk buffers to realign ourselves
 691                                    precisely with the master.
 692                                 */
 693
 694
 695                                 bool ok = true;
 696                                 framecnt_t frame_delta = slave_transport_frame - _transport_frame;
 697
 698                                 boost::shared_ptr<RouteList> rl = routes.reader();
 699                                 for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 700                                         boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 701                                         if (tr && !tr->can_internal_playback_seek (frame_delta)) {
 702                                                 ok = false;
 703                                                 break;
 704                                         }
 705                                 }
 706
 707                                 if (ok) {
 708                                         for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
 709                                                 boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
 710                                                 if (tr) {
 711                                                         tr->internal_playback_seek (frame_delta);
 712                                                 }
 713                                         }
 714                                         _transport_frame += frame_delta;
 715
 716                                 } else {
 717                                         cerr << "cannot micro-seek\n";
 718                                         /* XXX what? */
 719                                 }
 720
 721                                 memset (delta_accumulator, 0, sizeof (int32_t) * delta_accumulator_size);
 722                                 average_slave_delta = 0L;
 723                         }
 724                 }
 725
 726                 if (_slave_state == Running && _transport_speed == 0.0f) {
 727                         DEBUG_TRACE (DEBUG::Slave, "slave starts transport\n");
 728                         start_transport ();
 729                 }
 730
 731         } else { // slave_speed is 0
 732
 733                 /* slave has stopped */
 734
 735                 if (_transport_speed != 0.0f) {
 736                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 frame %2 tf %3\n", slave_speed, slave_transport_frame, _transport_frame));
 737                         stop_transport ();
 738                 }
 739
 740                 if (slave_transport_frame != _transport_frame) {
 741                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, move to %1\n", slave_transport_frame));
 742                         force_locate (slave_transport_frame, false);
 743                 }
 744
 745                 _slave_state = Stopped;
 746         }
 747 }
 748
 749 void
 750 Session::follow_slave_silently (pframes_t nframes, float slave_speed)
 751 {
 752         if (slave_speed && _transport_speed) {
 753
 754                 /* something isn't right, but we should move with the master
 755                    for now.
 756                 */
 757
 758                 bool need_butler;
 759
 760                 silent_process_routes (nframes, need_butler);
 761
 762                 get_track_statistics ();
 763
 764                 if (need_butler) {
 765                         _butler->summon ();
 766                 }
 767
 768                 int32_t frames_moved = (int32_t) floor (_transport_speed * nframes);
 769
 770                 if (frames_moved < 0) {
 771                         decrement_transport_position (-frames_moved);
 772                 } else {
 773                         increment_transport_position (frames_moved);
 774                 }
 775
 776                 framepos_t const stop_limit = compute_stop_limit ();
 777                 maybe_stop (stop_limit);
 778         }
 779 }
 780
 781 void
 782 Session::process_without_events (pframes_t nframes)
 783 {
 784         bool session_needs_butler = false;
 785         framecnt_t frames_moved;
 786
 787         if (!process_can_proceed()) {
 788                 _silent = true;
 789                 return;
 790         }
 791
 792         if (!_exporting && _slave) {
 793                 if (!follow_slave (nframes)) {
 794                         return;
 795                 }
 796         }
 797
 798         if (_transport_speed == 0) {
 799                 fail_roll (nframes);
 800                 return;
 801         }
 802
 803         if (_transport_speed == 1.0) {
 804                 frames_moved = (framecnt_t) nframes;
 805         } else {
 806                 interpolation.set_target_speed (fabs(_target_transport_speed));
 807                 interpolation.set_speed (fabs(_transport_speed));
 808                 frames_moved = (framecnt_t) interpolation.interpolate (0, nframes, 0, 0);
 809         }
 810
 811         if (!_exporting && !timecode_transmission_suspended()) {
 812                 send_midi_time_code_for_cycle (_transport_frame, _transport_frame + frames_moved, nframes);
 813         }
 814
 815         framepos_t const stop_limit = compute_stop_limit ();
 816
 817         if (maybe_stop (stop_limit)) {
 818                 fail_roll (nframes);
 819                 return;
 820         }
 821
 822         if (maybe_sync_start (nframes)) {
 823                 return;
 824         }
 825
 826         click (_transport_frame, nframes);
 827
 828         if (process_routes (nframes, session_needs_butler)) {
 829                 fail_roll (nframes);
 830                 return;
 831         }
 832
 833         get_track_statistics ();
 834
 835         /* XXX: I'm not sure whether this is correct, but at least it
 836            matches process_with_events, so that this new frames_moved
 837            is -ve when transport speed is -ve.  This means that the
 838            transport position is updated correctly when we are in
 839            reverse.  It seems a bit wrong that we're not using the
 840            interpolator to compute this.
 841         */
 842
 843         frames_moved = (framecnt_t) floor (_transport_speed * nframes);
 844
 845         if (frames_moved < 0) {
 846                 decrement_transport_position (-frames_moved);
 847         } else {
 848                 increment_transport_position (frames_moved);
 849         }
 850
 851         maybe_stop (stop_limit);
 852         check_declick_out ();
 853
 854         if (session_needs_butler) {
 855                 _butler->summon ();
 856         }
 857 }
 858
 859 /** Process callback used when the auditioner is active.
 860  * @param nframes number of frames to process.
 861  */
 862 void
 863 Session::process_audition (pframes_t nframes)
 864 {
 865         SessionEvent* ev;
 866         boost::shared_ptr<RouteList> r = routes.reader ();
 867
 868         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 869                 if (!(*i)->is_hidden()) {
 870                         (*i)->silence (nframes);
 871                 }
 872         }
 873
 874         /* run the auditioner, and if it says we need butler service, ask for it */
 875
 876         if (auditioner->play_audition (nframes) > 0) {
 877                 _butler->summon ();
 878         }
 879
 880         /* if using a monitor section, run it because otherwise we don't hear anything */
 881
 882         if (auditioner->needs_monitor()) {
 883                 _monitor_out->passthru (_transport_frame, _transport_frame + nframes, nframes, false);
 884         }
 885
 886         /* handle pending events */
 887
 888         while (pending_events.read (&ev, 1) == 1) {
 889                 merge_event (ev);
 890         }
 891
 892         /* if we are not in the middle of a state change,
 893            and there are immediate events queued up,
 894            process them.
 895         */
 896
 897         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 898                 SessionEvent *ev = immediate_events.front ();
 899                 immediate_events.pop_front ();
 900                 process_event (ev);
 901         }
 902
 903         if (!auditioner->auditioning()) {
 904                 /* auditioner no longer active, so go back to the normal process callback */
 905                 process_function = &Session::process_with_events;
 906         }
 907 }
 908
 909 bool
 910 Session::maybe_sync_start (pframes_t & nframes)
 911 {
 912         pframes_t sync_offset;
 913
 914         if (!waiting_for_sync_offset) {
 915                 return false;
 916         }
 917
 918         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
 919
 920                 /* generate silence up to the sync point, then
 921                    adjust nframes + offset to reflect whatever
 922                    is left to do.
 923                 */
 924
 925                 no_roll (sync_offset);
 926                 nframes -= sync_offset;
 927                 Port::increment_global_port_buffer_offset (sync_offset);
 928                 waiting_for_sync_offset = false;
 929
 930                 if (nframes == 0) {
 931                         return true; // done, nothing left to process
 932                 }
 933
 934         } else {
 935
 936                 /* sync offset point is not within this process()
 937                    cycle, so just generate silence. and don't bother
 938                    with any fancy stuff here, just the minimal silence.
 939                 */
 940
 941                 _silent = true;
 942
 943                 if (Config->get_locate_while_waiting_for_sync()) {
 944                         if (micro_locate (nframes)) {
 945                                 /* XXX ERROR !!! XXX */
 946                         }
 947                 }
 948
 949                 return true; // done, nothing left to process
 950         }
 951
 952         return false;
 953 }
 954
 955 void
 956 Session::queue_event (SessionEvent* ev)
 957 {
 958         if (_state_of_the_state & Deletion) {
 959                 return;
 960         } else if (_state_of_the_state & Loading) {
 961                 merge_event (ev);
 962         } else {
 963                 pending_events.write (&ev, 1);
 964         }
 965 }
 966
 967 void
 968 Session::set_next_event ()
 969 {
 970         if (events.empty()) {
 971                 next_event = events.end();
 972                 return;
 973         }
 974
 975         if (next_event == events.end()) {
 976                 next_event = events.begin();
 977         }
 978
 979         if ((*next_event)->action_frame > _transport_frame) {
 980                 next_event = events.begin();
 981         }
 982
 983         for (; next_event != events.end(); ++next_event) {
 984                 if ((*next_event)->action_frame >= _transport_frame) {
 985                         break;
 986                 }
 987         }
 988 }
 989
 990 void
 991 Session::process_event (SessionEvent* ev)
 992 {
 993         bool remove = true;
 994         bool del = true;
 995
 996         /* if we're in the middle of a state change (i.e. waiting
 997            for the butler thread to complete the non-realtime
 998            part of the change), we'll just have to queue this
 999            event for a time when the change is complete.
1000         */
1001
1002         if (non_realtime_work_pending()) {
1003
1004                 /* except locates, which we have the capability to handle */
1005
1006                 if (ev->type != SessionEvent::Locate) {
1007                         immediate_events.insert (immediate_events.end(), ev);
1008                         _remove_event (ev);
1009                         return;
1010                 }
1011         }
1012
1013         DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("Processing event: %1 @ %2\n", enum_2_string (ev->type), _transport_frame));
1014
1015         switch (ev->type) {
1016         case SessionEvent::SetLoop:
1017                 set_play_loop (ev->yes_or_no);
1018                 break;
1019
1020         case SessionEvent::AutoLoop:
1021                 if (play_loop) {
1022                         start_locate (ev->target_frame, true, false, Config->get_seamless_loop());
1023                 }
1024                 remove = false;
1025                 del = false;
1026                 break;
1027
1028         case SessionEvent::Locate:
1029                 if (ev->yes_or_no) {
1030                         // cerr << "forced locate to " << ev->target_frame << endl;
1031                         locate (ev->target_frame, false, true, false);
1032                 } else {
1033                         // cerr << "soft locate to " << ev->target_frame << endl;
1034                         start_locate (ev->target_frame, false, true, false);
1035                 }
1036                 _send_timecode_update = true;
1037                 break;
1038
1039         case SessionEvent::LocateRoll:
1040                 if (ev->yes_or_no) {
1041                         // cerr << "forced locate to+roll " << ev->target_frame << endl;
1042                         locate (ev->target_frame, true, true, false);
1043                 } else {
1044                         // cerr << "soft locate to+roll " << ev->target_frame << endl;
1045                         start_locate (ev->target_frame, true, true, false);
1046                 }
1047                 _send_timecode_update = true;
1048                 break;
1049
1050         case SessionEvent::LocateRollLocate:
1051                 // locate is handled by ::request_roll_at_and_return()
1052                 _requested_return_frame = ev->target_frame;
1053                 request_locate (ev->target2_frame, true);
1054                 break;
1055
1056
1057         case SessionEvent::SetTransportSpeed:
1058                 set_transport_speed (ev->speed, ev->yes_or_no, ev->second_yes_or_no);
1059                 break;
1060
1061         case SessionEvent::PunchIn:
1062                 // cerr << "PunchIN at " << transport_frame() << endl;
1063                 if (config.get_punch_in() && record_status() == Enabled) {
1064                         enable_record ();
1065                 }
1066                 remove = false;
1067                 del = false;
1068                 break;
1069
1070         case SessionEvent::PunchOut:
1071                 // cerr << "PunchOUT at " << transport_frame() << endl;
1072                 if (config.get_punch_out()) {
1073                         step_back_from_record ();
1074                 }
1075                 remove = false;
1076                 del = false;
1077                 break;
1078
1079         case SessionEvent::StopOnce:
1080                 if (!non_realtime_work_pending()) {
1081                         stop_transport (ev->yes_or_no);
1082                         _clear_event_type (SessionEvent::StopOnce);
1083                 }
1084                 remove = false;
1085                 del = false;
1086                 break;
1087
1088         case SessionEvent::RangeStop:
1089                 if (!non_realtime_work_pending()) {
1090                         stop_transport (ev->yes_or_no);
1091                 }
1092                 remove = false;
1093                 del = false;
1094                 break;
1095
1096         case SessionEvent::RangeLocate:
1097                 start_locate (ev->target_frame, true, true, false);
1098                 remove = false;
1099                 del = false;
1100                 break;
1101
1102         case SessionEvent::Overwrite:
1103                 overwrite_some_buffers (static_cast<Track*>(ev->ptr));
1104                 break;
1105
1106         case SessionEvent::SetTrackSpeed:
1107                 set_track_speed (static_cast<Track*> (ev->ptr), ev->speed);
1108                 break;
1109
1110         case SessionEvent::SetSyncSource:
1111                 use_sync_source (ev->slave);
1112                 break;
1113
1114         case SessionEvent::Audition:
1115                 set_audition (ev->region);
1116                 // drop reference to region
1117                 ev->region.reset ();
1118                 break;
1119
1120         case SessionEvent::InputConfigurationChange:
1121                 add_post_transport_work (PostTransportInputChange);
1122                 _butler->schedule_transport_work ();
1123                 break;
1124
1125         case SessionEvent::SetPlayAudioRange:
1126                 set_play_range (ev->audio_range, (ev->speed == 1.0f));
1127                 break;
1128
1129         case SessionEvent::RealTimeOperation:
1130                 process_rtop (ev);
1131                 del = false; // other side of RT request needs to clean up
1132                 break;
1133
1134         case SessionEvent::AdjustPlaybackBuffering:
1135                 schedule_playback_buffering_adjustment ();
1136                 break;
1137
1138         case SessionEvent::AdjustCaptureBuffering:
1139                 schedule_capture_buffering_adjustment ();
1140                 break;
1141
1142         case SessionEvent::SetTimecodeTransmission:
1143                 g_atomic_int_set (&_suspend_timecode_transmission, ev->yes_or_no ? 0 : 1);
1144                 break;
1145
1146         default:
1147           fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
1148                 /*NOTREACHED*/
1149                 break;
1150         };
1151
1152         if (remove) {
1153                 del = del && !_remove_event (ev);
1154         }
1155
1156         if (del) {
1157                 delete ev;
1158         }
1159 }
1160
1161 framepos_t
1162 Session::compute_stop_limit () const
1163 {
1164         if (!Config->get_stop_at_session_end ()) {
1165                 return max_framepos;
1166         }
1167
1168         bool const punching_in = (config.get_punch_in () && _locations->auto_punch_location());
1169         bool const punching_out = (config.get_punch_out () && _locations->auto_punch_location());
1170
1171         if (actively_recording ()) {
1172                 /* permanently recording */
1173                 return max_framepos;
1174         } else if (punching_in && !punching_out) {
1175                 /* punching in but never out */
1176                 return max_framepos;
1177         } else if (punching_in && punching_out && _locations->auto_punch_location()->end() > current_end_frame()) {
1178                 /* punching in and punching out after session end */
1179                 return max_framepos;
1180         }
1181
1182         return current_end_frame ();
1183 }