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/session.h"
  37 #include "ardour/slave.h"
  38 #include "ardour/timestamps.h"
  39
  40 #include "midi++/manager.h"
  41
  42 #include "i18n.h"
  43
  44 using namespace ARDOUR;
  45 using namespace PBD;
  46 using namespace std;
  47
  48 /** Called by the audio engine when there is work to be done with JACK.
  49  * @param nframes Number of frames to process.
  50  */
  51 void
  52 Session::process (nframes_t nframes)
  53 {
  54         // This is no more the appropriate place to call cycle
  55         // start. cycle_start needs to be called at the Route::roll()
  56         // where the signals which we want to mixdown have been calculated.
  57         //
  58         MIDI::Manager::instance()->cycle_start(nframes);
  59
  60         _silent = false;
  61
  62         if (processing_blocked()) {
  63                 _silent = true;
  64                 return;
  65         }
  66
  67         if (non_realtime_work_pending()) {
  68                 if (!_butler->transport_work_requested ()) {
  69                         post_transport ();
  70                 }
  71         }
  72
  73         (this->*process_function) (nframes);
  74
  75         // the ticker is for sending time information like MidiClock
  76         nframes_t transport_frames = transport_frame();
  77         BBT_Time  transport_bbt;
  78         bbt_time(transport_frames, transport_bbt);
  79         Timecode::Time transport_timecode;
  80         timecode_time(transport_frames, transport_timecode);
  81         tick (transport_frames, transport_bbt, transport_timecode); /* EMIT SIGNAL */
  82
  83         SendFeedback (); /* EMIT SIGNAL */
  84
  85         MIDI::Manager::instance()->cycle_end();
  86 }
  87
  88 void
  89 Session::prepare_diskstreams ()
  90 {
  91         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
  92         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
  93                 (*i)->prepare ();
  94         }
  95 }
  96
  97 int
  98 Session::fail_roll (nframes_t nframes)
  99 {
 100         return no_roll (nframes);
 101 }
 102
 103 int
 104 Session::no_roll (nframes_t nframes)
 105 {
 106         nframes_t end_frame = _transport_frame + nframes; // FIXME: varispeed + no_roll ??
 107         int ret = 0;
 108         bool declick = get_transport_declick_required();
 109         boost::shared_ptr<RouteList> r = routes.reader ();
 110
 111         if (_click_io) {
 112                 _click_io->silence (nframes);
 113         }
 114
 115         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 116
 117                 if ((*i)->is_hidden()) {
 118                         continue;
 119                 }
 120
 121                 (*i)->set_pending_declick (declick);
 122
 123                 if ((*i)->no_roll (nframes, _transport_frame, end_frame, non_realtime_work_pending(),
 124                                    actively_recording(), declick)) {
 125                         error << string_compose(_("Session: error in no roll for %1"), (*i)->name()) << endmsg;
 126                         ret = -1;
 127                         break;
 128                 }
 129         }
 130
 131         return ret;
 132 }
 133
 134 int
 135 Session::process_routes (nframes_t nframes)
 136 {
 137         bool record_active;
 138         int  declick = get_transport_declick_required();
 139         bool rec_monitors = get_rec_monitors_input();
 140         boost::shared_ptr<RouteList> r = routes.reader ();
 141
 142         if (transport_sub_state & StopPendingCapture) {
 143                 /* force a declick out */
 144                 declick = -1;
 145         }
 146
 147         record_active = actively_recording(); // || (get_record_enabled() && get_punch_in());
 148
 149         const nframes_t start_frame = _transport_frame;
 150         const nframes_t end_frame = _transport_frame + (nframes_t)floor(nframes * _transport_speed);
 151
 152         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 153
 154                 int ret;
 155
 156                 if ((*i)->is_hidden()) {
 157                         continue;
 158                 }
 159
 160                 (*i)->set_pending_declick (declick);
 161
 162                 if ((ret = (*i)->roll (nframes, start_frame, end_frame, declick, record_active, rec_monitors)) < 0) {
 163
 164                         /* we have to do this here. Route::roll() for an AudioTrack will have called AudioDiskstream::process(),
 165                            and the DS will expect AudioDiskstream::commit() to be called. but we're aborting from that
 166                            call path, so make sure we release any outstanding locks here before we return failure.
 167                         */
 168
 169                         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 170                         for (DiskstreamList::iterator ids = dsl->begin(); ids != dsl->end(); ++ids) {
 171                                 (*ids)->recover ();
 172                         }
 173
 174                         stop_transport ();
 175                         return -1;
 176                 }
 177         }
 178
 179         return 0;
 180 }
 181
 182 int
 183 Session::silent_process_routes (nframes_t nframes)
 184 {
 185         bool record_active = actively_recording();
 186         int  declick = get_transport_declick_required();
 187         bool rec_monitors = get_rec_monitors_input();
 188         boost::shared_ptr<RouteList> r = routes.reader ();
 189
 190         if (transport_sub_state & StopPendingCapture) {
 191                 /* force a declick out */
 192                 declick = -1;
 193         }
 194
 195         const nframes_t start_frame = _transport_frame;
 196         const nframes_t end_frame = _transport_frame + lrintf(nframes * _transport_speed);
 197
 198         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 199
 200                 int ret;
 201
 202                 if ((*i)->is_hidden()) {
 203                         continue;
 204                 }
 205
 206                 if ((ret = (*i)->silent_roll (nframes, start_frame, end_frame, record_active, rec_monitors)) < 0) {
 207
 208                         /* we have to do this here. Route::roll() for an AudioTrack will have called AudioDiskstream::process(),
 209                            and the DS will expect AudioDiskstream::commit() to be called. but we're aborting from that
 210                            call path, so make sure we release any outstanding locks here before we return failure.
 211                         */
 212
 213                         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 214                         for (DiskstreamList::iterator ids = dsl->begin(); ids != dsl->end(); ++ids) {
 215                                 (*ids)->recover ();
 216                         }
 217
 218                         stop_transport ();
 219                         return -1;
 220                 }
 221         }
 222
 223         return 0;
 224 }
 225
 226 void
 227 Session::commit_diskstreams (nframes_t nframes, bool &needs_butler)
 228 {
 229         int dret;
 230         float pworst = 1.0f;
 231         float cworst = 1.0f;
 232
 233         boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 234         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 235
 236                 if ((*i)->hidden()) {
 237                         continue;
 238                 }
 239
 240                 /* force all diskstreams not handled by a Route to call do their stuff.
 241                    Note: the diskstreams that were handled by a route will just return zero
 242                    from this call, because they know they were processed. So in fact, this
 243                    also runs commit() for every diskstream.
 244                  */
 245
 246                 if ((dret = (*i)->process (_transport_frame, nframes, actively_recording(), get_rec_monitors_input())) == 0) {
 247                         if ((*i)->commit (nframes)) {
 248                                 needs_butler = true;
 249                         }
 250
 251                 } else if (dret < 0) {
 252                         (*i)->recover();
 253                 }
 254
 255                 pworst = min (pworst, (*i)->playback_buffer_load());
 256                 cworst = min (cworst, (*i)->capture_buffer_load());
 257         }
 258
 259         uint32_t pmin = g_atomic_int_get (&_playback_load);
 260         uint32_t pminold = g_atomic_int_get (&_playback_load_min);
 261         uint32_t cmin = g_atomic_int_get (&_capture_load);
 262         uint32_t cminold = g_atomic_int_get (&_capture_load_min);
 263
 264         g_atomic_int_set (&_playback_load, (uint32_t) floor (pworst * 100.0f));
 265         g_atomic_int_set (&_capture_load, (uint32_t) floor (cworst * 100.0f));
 266         g_atomic_int_set (&_playback_load_min, min (pmin, pminold));
 267         g_atomic_int_set (&_capture_load_min, min (cmin, cminold));
 268
 269         if (actively_recording()) {
 270                 set_dirty();
 271         }
 272 }
 273
 274 /** Process callback used when the auditioner is not active */
 275 void
 276 Session::process_with_events (nframes_t nframes)
 277 {
 278         SessionEvent*         ev;
 279         nframes_t      this_nframes;
 280         nframes_t      end_frame;
 281         bool           session_needs_butler = false;
 282         nframes_t      stop_limit;
 283         long           frames_moved;
 284
 285         /* make sure the auditioner is silent */
 286
 287         if (auditioner) {
 288                 auditioner->silence (nframes);
 289         }
 290
 291         /* handle any pending events */
 292
 293         while (pending_events.read (&ev, 1) == 1) {
 294                 merge_event (ev);
 295         }
 296
 297         /* if we are not in the middle of a state change,
 298            and there are immediate events queued up,
 299            process them.
 300         */
 301
 302         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 303                 SessionEvent *ev = immediate_events.front ();
 304                 immediate_events.pop_front ();
 305                 process_event (ev);
 306         }
 307
 308         /* Events caused a transport change, send an MTC Full Frame (Timecode) message.
 309          * This is sent whether rolling or not, to give slaves an idea of ardour time
 310          * on locates (and allow slow slaves to position and prepare for rolling)
 311          */
 312         if (_send_timecode_update) {
 313                 send_full_time_code(nframes);
 314                 deliver_mmc (MIDI::MachineControl::cmdLocate, _transport_frame);
 315         }
 316
 317         if (!process_can_proceed()) {
 318                 _silent = true;
 319                 return;
 320         }
 321
 322         if (events.empty() || next_event == events.end()) {
 323                 process_without_events (nframes);
 324                 return;
 325         }
 326
 327         if (_transport_speed == 1.0) {
 328                 frames_moved = (long) nframes;
 329         } else {
 330                 interpolation.set_target_speed (fabs(_target_transport_speed));
 331                 interpolation.set_speed (fabs(_transport_speed));
 332                 frames_moved = (long) interpolation.interpolate (0, nframes, 0, 0);
 333         }
 334
 335         end_frame = _transport_frame + (nframes_t)frames_moved;
 336
 337         {
 338                 SessionEvent* this_event;
 339                 Events::iterator the_next_one;
 340
 341                 if (!process_can_proceed()) {
 342                         _silent = true;
 343                         return;
 344                 }
 345
 346                 if (!_exporting && _slave) {
 347                         if (!follow_slave (nframes)) {
 348                                 return;
 349                         }
 350                 }
 351
 352                 if (_transport_speed == 0) {
 353                         no_roll (nframes);
 354                         return;
 355                 }
 356
 357                 if (!_exporting) {
 358                         send_midi_time_code_for_cycle (nframes);
 359                 }
 360
 361                 if (actively_recording()) {
 362                         stop_limit = max_frames;
 363                 } else {
 364
 365                         if (Config->get_stop_at_session_end()) {
 366                                 stop_limit = current_end_frame();
 367                         } else {
 368                                 stop_limit = max_frames;
 369                         }
 370                 }
 371
 372                 if (maybe_stop (stop_limit)) {
 373                         no_roll (nframes);
 374                         return;
 375                 }
 376
 377                 this_event = *next_event;
 378                 the_next_one = next_event;
 379                 ++the_next_one;
 380
 381                 /* yes folks, here it is, the actual loop where we really truly
 382                    process some audio
 383                 */
 384
 385                 while (nframes) {
 386
 387                         this_nframes = nframes; /* real (jack) time relative */
 388                         frames_moved = (long) floor (_transport_speed * nframes); /* transport relative */
 389
 390                         /* running an event, position transport precisely to its time */
 391                         if (this_event && this_event->action_frame <= end_frame && this_event->action_frame >= _transport_frame) {
 392                                 /* this isn't quite right for reverse play */
 393                                 frames_moved = (long) (this_event->action_frame - _transport_frame);
 394                                 this_nframes = (nframes_t) abs( floor(frames_moved / _transport_speed) );
 395                         }
 396
 397                         if (this_nframes) {
 398
 399                                 click (_transport_frame, this_nframes);
 400
 401                                 /* now process frames between now and the first event in this block */
 402                                 prepare_diskstreams ();
 403
 404                                 if (process_routes (this_nframes)) {
 405                                         fail_roll (nframes);
 406                                         return;
 407                                 }
 408
 409                                 commit_diskstreams (this_nframes, session_needs_butler);
 410
 411                                 nframes -= this_nframes;
 412
 413                                 if (frames_moved < 0) {
 414                                         decrement_transport_position (-frames_moved);
 415                                 } else {
 416                                         increment_transport_position (frames_moved);
 417                                 }
 418
 419                                 maybe_stop (stop_limit);
 420                                 check_declick_out ();
 421                         }
 422
 423                         _engine.split_cycle (this_nframes);
 424
 425                         /* now handle this event and all others scheduled for the same time */
 426
 427                         while (this_event && this_event->action_frame == _transport_frame) {
 428                                 process_event (this_event);
 429
 430                                 if (the_next_one == events.end()) {
 431                                         this_event = 0;
 432                                 } else {
 433                                         this_event = *the_next_one;
 434                                         ++the_next_one;
 435                                 }
 436                         }
 437
 438                         /* if an event left our state changing, do the right thing */
 439
 440                         if (nframes && non_realtime_work_pending()) {
 441                                 no_roll (nframes);
 442                                 break;
 443                         }
 444
 445                         /* this is necessary to handle the case of seamless looping */
 446                         end_frame = _transport_frame + (nframes_t) floor (nframes * _transport_speed);
 447
 448                 }
 449
 450                 set_next_event ();
 451
 452         } /* implicit release of route lock */
 453
 454         if (session_needs_butler) {
 455                 _butler->summon ();
 456         }
 457 }
 458
 459 void
 460 Session::reset_slave_state ()
 461 {
 462         average_slave_delta = 1800;
 463         delta_accumulator_cnt = 0;
 464         have_first_delta_accumulator = false;
 465         _slave_state = Stopped;
 466 }
 467
 468 bool
 469 Session::transport_locked () const
 470 {
 471         Slave* sl = _slave;
 472
 473         if (!locate_pending() && (!config.get_external_sync() || (sl && sl->ok() && sl->locked()))) {
 474                 return true;
 475         }
 476
 477         return false;
 478 }
 479
 480 bool
 481 Session::follow_slave (nframes_t nframes)
 482 {
 483         double slave_speed;
 484         nframes64_t slave_transport_frame;
 485         nframes_t this_delta;
 486         int dir;
 487
 488         if (!_slave->ok()) {
 489                 stop_transport ();
 490                 config.set_external_sync (false);
 491                 goto noroll;
 492         }
 493
 494         _slave->speed_and_position (slave_speed, slave_transport_frame);
 495
 496         DEBUG_TRACE (DEBUG::Slave, string_compose ("Slave position %1 speed %2\n", slave_transport_frame, slave_speed));
 497
 498         if (!_slave->locked()) {
 499                 DEBUG_TRACE (DEBUG::Slave, "slave not locked\n");
 500                 goto noroll;
 501         }
 502
 503         if (slave_transport_frame > _transport_frame) {
 504                 this_delta = slave_transport_frame - _transport_frame;
 505                 dir = 1;
 506         } else {
 507                 this_delta = _transport_frame - slave_transport_frame;
 508                 dir = -1;
 509         }
 510
 511         if (_slave->starting()) {
 512                 slave_speed = 0.0f;
 513         }
 514
 515         if (_slave->is_always_synced() || config.get_timecode_source_is_synced()) {
 516
 517                 /* if the TC source is synced, then we assume that its
 518                    speed is binary: 0.0 or 1.0
 519                 */
 520
 521                 if (slave_speed != 0.0f) {
 522                         slave_speed = 1.0f;
 523                 }
 524
 525         } else {
 526
 527                 /* if we are chasing and the average delta between us and the
 528                    master gets too big, we want to switch to silent
 529                    motion. so keep track of that here.
 530                 */
 531
 532                 if (_slave_state == Running) {
 533                         calculate_moving_average_of_slave_delta(dir, this_delta);
 534                 }
 535         }
 536
 537         track_slave_state (slave_speed, slave_transport_frame, this_delta);
 538
 539         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave state %1 @ %2 speed %3 cur delta %4 avg delta %5\n",
 540                                                    _slave_state, slave_transport_frame, slave_speed, this_delta, average_slave_delta));
 541
 542
 543         if (_slave_state == Running && !_slave->is_always_synced() && !config.get_timecode_source_is_synced()) {
 544
 545                 if (_transport_speed != 0.0f) {
 546
 547                         /*
 548                            note that average_dir is +1 or -1
 549                         */
 550
 551                         float delta;
 552
 553                         if (average_slave_delta == 0) {
 554                                 delta = this_delta;
 555                                 delta *= dir;
 556                         } else {
 557                                 delta = average_slave_delta;
 558                                 delta *= average_dir;
 559                         }
 560
 561 #ifndef NDEBUG
 562                         if (slave_speed != 0.0) {
 563                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("delta = %1 speed = %2 ts = %3 M@%4 S@%5 avgdelta %6\n",
 564                                                                            (int) (dir * this_delta),
 565                                                                            slave_speed,
 566                                                                            _transport_speed,
 567                                                                            _transport_frame,
 568                                                                            slave_transport_frame,
 569                                                                            average_slave_delta));
 570                         }
 571 #endif
 572
 573                         if (_slave->give_slave_full_control_over_transport_speed()) {
 574                                 set_transport_speed (slave_speed, false, false);
 575                         } else {
 576                                 float adjusted_speed = slave_speed + (1.5 * (delta /  float(_current_frame_rate)));
 577                                 request_transport_speed (adjusted_speed);
 578                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("adjust using %1 towards %2 ratio %3 current %4 slave @ %5\n",
 579                                                                            delta, adjusted_speed, adjusted_speed/slave_speed, _transport_speed,
 580                                                                            slave_speed));
 581                         }
 582
 583                         if (abs(average_slave_delta) > _slave->resolution()) {
 584                                 cerr << "average slave delta greater than slave resolution (" << _slave->resolution() << "), going to silent motion\n";
 585                                 goto silent_motion;
 586                         }
 587                 }
 588         }
 589
 590
 591         if (_slave_state == Running && !non_realtime_work_pending()) {
 592                 /* speed is set, we're locked, and good to go */
 593                 return true;
 594         }
 595
 596   silent_motion:
 597         DEBUG_TRACE (DEBUG::Slave, "silent motion\n")
 598         follow_slave_silently (nframes, slave_speed);
 599
 600   noroll:
 601         /* don't move at all */
 602         DEBUG_TRACE (DEBUG::Slave, "no roll\n")
 603         no_roll (nframes);
 604         return false;
 605 }
 606
 607 void
 608 Session::calculate_moving_average_of_slave_delta(int dir, nframes_t this_delta)
 609 {
 610         if (delta_accumulator_cnt >= delta_accumulator_size) {
 611                 have_first_delta_accumulator = true;
 612                 delta_accumulator_cnt = 0;
 613         }
 614
 615         if (delta_accumulator_cnt != 0 || this_delta < _current_frame_rate) {
 616                 delta_accumulator[delta_accumulator_cnt++] = long(dir) * long(this_delta);
 617         }
 618
 619         if (have_first_delta_accumulator) {
 620                 average_slave_delta = 0L;
 621                 for (int i = 0; i < delta_accumulator_size; ++i) {
 622                         average_slave_delta += delta_accumulator[i];
 623                 }
 624                 average_slave_delta /= long(delta_accumulator_size);
 625                 if (average_slave_delta < 0L) {
 626                         average_dir = -1;
 627                         average_slave_delta = abs(average_slave_delta);
 628                 } else {
 629                         average_dir = 1;
 630                 }
 631         }
 632 }
 633
 634 void
 635 Session::track_slave_state (float slave_speed, nframes_t slave_transport_frame, nframes_t this_delta)
 636 {
 637         if (slave_speed != 0.0f) {
 638
 639                 /* slave is running */
 640
 641                 switch (_slave_state) {
 642                 case Stopped:
 643                         if (_slave->requires_seekahead()) {
 644                                 slave_wait_end = slave_transport_frame + _slave->seekahead_distance ();
 645                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, but running, requires seekahead to %1\n", slave_wait_end));
 646                                 /* we can call locate() here because we are in process context */
 647                                 locate (slave_wait_end, false, false);
 648                                 _slave_state = Waiting;
 649
 650                         } else {
 651
 652                                 _slave_state = Running;
 653
 654                                 Location* al = _locations.auto_loop_location();
 655
 656                                 if (al && play_loop && (slave_transport_frame < al->start() || slave_transport_frame > al->end())) {
 657                                         // cancel looping
 658                                         request_play_loop(false);
 659                                 }
 660
 661                                 if (slave_transport_frame != _transport_frame) {
 662                                         locate (slave_transport_frame, false, false);
 663                                 }
 664                         }
 665                         break;
 666
 667                 case Waiting:
 668                 default:
 669                         break;
 670                 }
 671
 672                 if (_slave_state == Waiting) {
 673
 674                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave waiting at %1\n", slave_transport_frame));
 675
 676                         if (slave_transport_frame >= slave_wait_end) {
 677
 678                                 DEBUG_TRACE (DEBUG::Slave, string_compose ("slave start at %1 vs %2\n", slave_transport_frame, _transport_frame));
 679
 680                                 _slave_state = Running;
 681
 682                                 /* now perform a "micro-seek" within the disk buffers to realign ourselves
 683                                    precisely with the master.
 684                                 */
 685
 686
 687                                 bool ok = true;
 688                                 nframes_t frame_delta = slave_transport_frame - _transport_frame;
 689
 690                                 boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 691
 692                                 for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 693                                         if (!(*i)->can_internal_playback_seek (frame_delta)) {
 694                                                 ok = false;
 695                                                 break;
 696                                         }
 697                                 }
 698
 699                                 if (ok) {
 700                                         for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
 701                                                 (*i)->internal_playback_seek (frame_delta);
 702                                         }
 703                                         _transport_frame += frame_delta;
 704
 705                                 } else {
 706                                         cerr << "cannot micro-seek\n";
 707                                         /* XXX what? */
 708                                 }
 709
 710                                 memset (delta_accumulator, 0, sizeof (long) * delta_accumulator_size);
 711                                 average_slave_delta = 0L;
 712                                 this_delta = 0;
 713                         }
 714                 }
 715
 716                 if (_slave_state == Running && _transport_speed == 0.0f) {
 717                         DEBUG_TRACE (DEBUG::Slave, "slave starts transport\n");
 718                         start_transport ();
 719                 }
 720
 721         } else { // slave_speed is 0
 722
 723                 /* slave has stopped */
 724
 725                 if (_transport_speed != 0.0f) {
 726                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stops transport: %1 frame %2 tf %3\n", slave_speed, slave_transport_frame, _transport_frame));
 727                         stop_transport();
 728                 }
 729
 730                 if (slave_transport_frame != _transport_frame) {
 731                         DEBUG_TRACE (DEBUG::Slave, string_compose ("slave stopped, move to %1\n", slave_transport_frame));
 732                         force_locate (slave_transport_frame, false);
 733                 }
 734
 735                 _slave_state = Stopped;
 736         }
 737 }
 738
 739 void
 740 Session::follow_slave_silently (nframes_t nframes, float slave_speed)
 741 {
 742         if (slave_speed && _transport_speed) {
 743
 744                 /* something isn't right, but we should move with the master
 745                    for now.
 746                 */
 747
 748                 bool need_butler;
 749
 750                 prepare_diskstreams ();
 751                 silent_process_routes (nframes);
 752                 commit_diskstreams (nframes, need_butler);
 753
 754                 if (need_butler) {
 755                         _butler->summon ();
 756                 }
 757
 758                 int32_t frames_moved = (int32_t) floor (_transport_speed * nframes);
 759
 760                 if (frames_moved < 0) {
 761                         decrement_transport_position (-frames_moved);
 762                 } else {
 763                         increment_transport_position (frames_moved);
 764                 }
 765
 766                 nframes_t stop_limit;
 767
 768                 if (actively_recording()) {
 769                         stop_limit = max_frames;
 770                 } else {
 771                         if (Config->get_stop_at_session_end()) {
 772                                 stop_limit = current_end_frame();
 773                         } else {
 774                                 stop_limit = max_frames;
 775                         }
 776                 }
 777
 778                 maybe_stop (stop_limit);
 779         }
 780 }
 781
 782 void
 783 Session::process_without_events (nframes_t nframes)
 784 {
 785         bool session_needs_butler = false;
 786         nframes_t stop_limit;
 787         long frames_moved;
 788
 789         if (!process_can_proceed()) {
 790                 _silent = true;
 791                 return;
 792         }
 793
 794         if (!_exporting && _slave) {
 795                 if (!follow_slave (nframes)) {
 796                         return;
 797                 }
 798         }
 799
 800         if (_transport_speed == 0) {
 801                 fail_roll (nframes);
 802                 return;
 803         }
 804
 805         if (!_exporting) {
 806                 send_midi_time_code_for_cycle (nframes);
 807         }
 808
 809         if (actively_recording()) {
 810                 stop_limit = max_frames;
 811         } else {
 812                 if (Config->get_stop_at_session_end()) {
 813                         stop_limit = current_end_frame();
 814                 } else {
 815                         stop_limit = max_frames;
 816                 }
 817         }
 818
 819         if (maybe_stop (stop_limit)) {
 820                 fail_roll (nframes);
 821                 return;
 822         }
 823
 824         if (maybe_sync_start (nframes)) {
 825                 return;
 826         }
 827
 828         click (_transport_frame, nframes);
 829
 830         prepare_diskstreams ();
 831
 832         if (_transport_speed == 1.0) {
 833                 frames_moved = (long) nframes;
 834         } else {
 835                 interpolation.set_target_speed (fabs(_target_transport_speed));
 836                 interpolation.set_speed (fabs(_transport_speed));
 837                 frames_moved = (long) interpolation.interpolate (0, nframes, 0, 0);
 838         }
 839
 840         if (process_routes (nframes)) {
 841                 fail_roll (nframes);
 842                 return;
 843         }
 844
 845         commit_diskstreams (nframes, session_needs_butler);
 846
 847         if (frames_moved < 0) {
 848                 decrement_transport_position (-frames_moved);
 849         } else {
 850                 increment_transport_position (frames_moved);
 851         }
 852
 853         maybe_stop (stop_limit);
 854         check_declick_out ();
 855
 856         if (session_needs_butler) {
 857                 _butler->summon ();
 858         }
 859 }
 860
 861 /** Process callback used when the auditioner is active.
 862  * @param nframes number of frames to process.
 863  */
 864 void
 865 Session::process_audition (nframes_t nframes)
 866 {
 867         SessionEvent* ev;
 868         boost::shared_ptr<RouteList> r = routes.reader ();
 869
 870         for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 871                 if (!(*i)->is_hidden()) {
 872                         (*i)->silence (nframes);
 873                 }
 874         }
 875
 876         /* run the auditioner, and if it says we need butler service, ask for it */
 877
 878         if (auditioner->play_audition (nframes) > 0) {
 879                 _butler->summon ();
 880         }
 881
 882         /* handle pending events */
 883
 884         while (pending_events.read (&ev, 1) == 1) {
 885                 merge_event (ev);
 886         }
 887
 888         /* if we are not in the middle of a state change,
 889            and there are immediate events queued up,
 890            process them.
 891         */
 892
 893         while (!non_realtime_work_pending() && !immediate_events.empty()) {
 894                 SessionEvent *ev = immediate_events.front ();
 895                 immediate_events.pop_front ();
 896                 process_event (ev);
 897         }
 898
 899         if (!auditioner->active()) {
 900                 /* auditioner no longer active, so go back to the normal process callback */
 901                 process_function = &Session::process_with_events;
 902         }
 903 }
 904
 905 bool
 906 Session::maybe_sync_start (nframes_t& nframes)
 907 {
 908         nframes_t sync_offset;
 909
 910         if (!waiting_for_sync_offset) {
 911                 return false;
 912         }
 913
 914         if (_engine.get_sync_offset (sync_offset) && sync_offset < nframes) {
 915
 916                 /* generate silence up to the sync point, then
 917                    adjust nframes + offset to reflect whatever
 918                    is left to do.
 919                 */
 920
 921                 no_roll (sync_offset);
 922                 nframes -= sync_offset;
 923                 Port::increment_port_offset (sync_offset);
 924                 waiting_for_sync_offset = false;
 925
 926                 if (nframes == 0) {
 927                         return true; // done, nothing left to process
 928                 }
 929
 930         } else {
 931
 932                 /* sync offset point is not within this process()
 933                    cycle, so just generate silence. and don't bother
 934                    with any fancy stuff here, just the minimal silence.
 935                 */
 936
 937                 _silent = true;
 938
 939                 if (Config->get_locate_while_waiting_for_sync()) {
 940                         if (micro_locate (nframes)) {
 941                                 /* XXX ERROR !!! XXX */
 942                         }
 943                 }
 944
 945                 return true; // done, nothing left to process
 946         }
 947
 948         return false;
 949 }
 950
 951 void
 952 Session::queue_event (SessionEvent* ev)
 953 {
 954         if (_state_of_the_state & Deletion) {
 955                 return;
 956         } else if (_state_of_the_state & Loading) {
 957                 merge_event (ev);
 958         } else {
 959                 pending_events.write (&ev, 1);
 960         }
 961 }
 962
 963 void
 964 Session::set_next_event ()
 965 {
 966         if (events.empty()) {
 967                 next_event = events.end();
 968                 return;
 969         }
 970
 971         if (next_event == events.end()) {
 972                 next_event = events.begin();
 973         }
 974
 975         if ((*next_event)->action_frame > _transport_frame) {
 976                 next_event = events.begin();
 977         }
 978
 979         for (; next_event != events.end(); ++next_event) {
 980                 if ((*next_event)->action_frame >= _transport_frame) {
 981                         break;
 982                 }
 983         }
 984 }
 985
 986 void
 987 Session::process_event (SessionEvent* ev)
 988 {
 989         bool remove = true;
 990         bool del = true;
 991
 992         /* if we're in the middle of a state change (i.e. waiting
 993            for the butler thread to complete the non-realtime
 994            part of the change), we'll just have to queue this
 995            event for a time when the change is complete.
 996         */
 997
 998         if (non_realtime_work_pending()) {
 999
1000                 /* except locates, which we have the capability to handle */
1001
1002                 if (ev->type != SessionEvent::Locate) {
1003                         immediate_events.insert (immediate_events.end(), ev);
1004                         _remove_event (ev);
1005                         return;
1006                 }
1007         }
1008
1009         DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("Processing event: %1 @ %2\n", enum_2_string (ev->type), _transport_frame));
1010
1011         switch (ev->type) {
1012         case SessionEvent::SetLoop:
1013                 set_play_loop (ev->yes_or_no);
1014                 break;
1015
1016         case SessionEvent::AutoLoop:
1017                 if (play_loop) {
1018                         start_locate (ev->target_frame, true, false, Config->get_seamless_loop());
1019                 }
1020                 remove = false;
1021                 del = false;
1022                 break;
1023
1024         case SessionEvent::Locate:
1025                 if (ev->yes_or_no) {
1026                         // cerr << "forced locate to " << ev->target_frame << endl;
1027                         locate (ev->target_frame, false, true, false);
1028                 } else {
1029                         // cerr << "soft locate to " << ev->target_frame << endl;
1030                         start_locate (ev->target_frame, false, true, false);
1031                 }
1032                 _send_timecode_update = true;
1033                 break;
1034
1035         case SessionEvent::LocateRoll:
1036                 if (ev->yes_or_no) {
1037                         // cerr << "forced locate to+roll " << ev->target_frame << endl;
1038                         locate (ev->target_frame, true, true, false);
1039                 } else {
1040                         // cerr << "soft locate to+roll " << ev->target_frame << endl;
1041                         start_locate (ev->target_frame, true, true, false);
1042                 }
1043                 _send_timecode_update = true;
1044                 break;
1045
1046         case SessionEvent::LocateRollLocate:
1047                 // locate is handled by ::request_roll_at_and_return()
1048                 _requested_return_frame = ev->target_frame;
1049                 request_locate (ev->target2_frame, true);
1050                 break;
1051
1052
1053         case SessionEvent::SetTransportSpeed:
1054                 set_transport_speed (ev->speed, ev->yes_or_no, ev->second_yes_or_no);
1055                 break;
1056
1057         case SessionEvent::PunchIn:
1058                 // cerr << "PunchIN at " << transport_frame() << endl;
1059                 if (config.get_punch_in() && record_status() == Enabled) {
1060                         enable_record ();
1061                 }
1062                 remove = false;
1063                 del = false;
1064                 break;
1065
1066         case SessionEvent::PunchOut:
1067                 // cerr << "PunchOUT at " << transport_frame() << endl;
1068                 if (config.get_punch_out()) {
1069                         step_back_from_record ();
1070                 }
1071                 remove = false;
1072                 del = false;
1073                 break;
1074
1075         case SessionEvent::StopOnce:
1076                 if (!non_realtime_work_pending()) {
1077                         stop_transport (ev->yes_or_no);
1078                         _clear_event_type (SessionEvent::StopOnce);
1079                 }
1080                 remove = false;
1081                 del = false;
1082                 break;
1083
1084         case SessionEvent::RangeStop:
1085                 if (!non_realtime_work_pending()) {
1086                         stop_transport (ev->yes_or_no);
1087                 }
1088                 remove = false;
1089                 del = false;
1090                 break;
1091
1092         case SessionEvent::RangeLocate:
1093                 start_locate (ev->target_frame, true, true, false);
1094                 remove = false;
1095                 del = false;
1096                 break;
1097
1098         case SessionEvent::Overwrite:
1099                 overwrite_some_buffers (static_cast<Diskstream*>(ev->ptr));
1100                 break;
1101
1102         case SessionEvent::SetDiskstreamSpeed:
1103                 set_diskstream_speed (static_cast<Diskstream*> (ev->ptr), ev->speed);
1104                 break;
1105
1106         case SessionEvent::SetSyncSource:
1107                 use_sync_source (ev->slave);
1108                 break;
1109
1110         case SessionEvent::Audition:
1111                 set_audition (ev->region);
1112                 // drop reference to region
1113                 ev->region.reset ();
1114                 break;
1115
1116         case SessionEvent::InputConfigurationChange:
1117                 add_post_transport_work (PostTransportInputChange);
1118                 _butler->schedule_transport_work ();
1119                 break;
1120
1121         case SessionEvent::SetPlayAudioRange:
1122                 set_play_range (ev->audio_range, (ev->speed == 1.0f));
1123                 break;
1124
1125         case SessionEvent::RealTimeOperation:
1126                 process_rtop (ev);
1127                 del = false; // other side of RT request needs to clean up
1128                 break;
1129
1130         default:
1131           fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
1132                 /*NOTREACHED*/
1133                 break;
1134         };
1135
1136         if (remove) {
1137                 del = del && !_remove_event (ev);
1138         }
1139
1140         if (del) {
1141                 delete ev;
1142         }
1143 }
1144
1145 void
1146 Session::process_rtop (SessionEvent* ev)
1147 {
1148         ev->rt_slot ();
1149         ev->rt_return (ev);
1150 }