libs/ardour/diskstream.cc

   1 /*
   2     Copyright (C) 2000-2006 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 <fstream>
  21 #include <cassert>
  22 #include <cstdio>
  23 #include <unistd.h>
  24 #include <cmath>
  25 #include <cerrno>
  26 #include <string>
  27 #include <climits>
  28 #include <fcntl.h>
  29 #include <cstdlib>
  30 #include <ctime>
  31 #include <sys/stat.h>
  32 #include <sys/mman.h>
  33
  34
  35 #include <glibmm/thread.h>
  36
  37 #include "pbd/error.h"
  38 #include "pbd/basename.h"
  39 #include "pbd/memento_command.h"
  40 #include "pbd/xml++.h"
  41 #include "pbd/stacktrace.h"
  42
  43 #include "ardour/ardour.h"
  44 #include "ardour/audioengine.h"
  45 #include "ardour/debug.h"
  46 #include "ardour/diskstream.h"
  47 #include "ardour/utils.h"
  48 #include "ardour/configuration.h"
  49 #include "ardour/audiofilesource.h"
  50 #include "ardour/send.h"
  51 #include "ardour/pannable.h"
  52 #include "ardour/panner_shell.h"
  53 #include "ardour/playlist.h"
  54 #include "ardour/cycle_timer.h"
  55 #include "ardour/region.h"
  56 #include "ardour/panner.h"
  57 #include "ardour/session.h"
  58 #include "ardour/io.h"
  59 #include "ardour/track.h"
  60
  61 #include "i18n.h"
  62 #include <locale.h>
  63
  64 using namespace std;
  65 using namespace ARDOUR;
  66 using namespace PBD;
  67
  68 /* XXX This goes uninitialized when there is no ~/.config/ardour3 directory.
  69  * I can't figure out why, so this will do for now (just stole the
  70  * default from configuration_vars.h).  0 is not a good value for
  71  * allocating buffer sizes..
  72  */
  73 ARDOUR::framecnt_t Diskstream::disk_io_chunk_frames = 1024 * 256 / sizeof (Sample);
  74
  75 PBD::Signal0<void>                Diskstream::DiskOverrun;
  76 PBD::Signal0<void>                Diskstream::DiskUnderrun;
  77
  78 Diskstream::Diskstream (Session &sess, const string &name, Flag flag)
  79         : SessionObject(sess, name)
  80         , i_am_the_modifier (0)
  81         , _track (0)
  82         , _record_enabled (0)
  83         , _visible_speed (1.0f)
  84         , _actual_speed (1.0f)
  85         , _buffer_reallocation_required (false)
  86         , _seek_required (false)
  87         , force_refill (false)
  88         , capture_start_frame (0)
  89         , capture_captured (0)
  90         , was_recording (false)
  91         , adjust_capture_position (0)
  92         , _capture_offset (0)
  93         , _roll_delay (0)
  94         , first_recordable_frame (max_framepos)
  95         , last_recordable_frame (max_framepos)
  96         , last_possibly_recording (0)
  97         , _alignment_style (ExistingMaterial)
  98         , _alignment_choice (Automatic)
  99         , _scrubbing (false)
 100         , _slaved (false)
 101         , loop_location (0)
 102         , overwrite_frame (0)
 103         , overwrite_offset (0)
 104         , _pending_overwrite (false)
 105         , overwrite_queued (false)
 106         , wrap_buffer_size (0)
 107         , speed_buffer_size (0)
 108         , _speed (1.0)
 109         , _target_speed (_speed)
 110         , file_frame (0)
 111         , playback_sample (0)
 112         , in_set_state (false)
 113         , _flags (flag)
 114         , deprecated_io_node (0)
 115 {
 116 }
 117
 118 Diskstream::Diskstream (Session& sess, const XMLNode& /*node*/)
 119         : SessionObject(sess, "unnamed diskstream")
 120         , i_am_the_modifier (0)
 121         , _track (0)
 122         , _record_enabled (0)
 123         , _visible_speed (1.0f)
 124         , _actual_speed (1.0f)
 125         , _buffer_reallocation_required (false)
 126         , _seek_required (false)
 127         , force_refill (false)
 128         , capture_start_frame (0)
 129         , capture_captured (0)
 130         , was_recording (false)
 131         , adjust_capture_position (0)
 132         , _capture_offset (0)
 133         , _roll_delay (0)
 134         , first_recordable_frame (max_framepos)
 135         , last_recordable_frame (max_framepos)
 136         , last_possibly_recording (0)
 137         , _alignment_style (ExistingMaterial)
 138         , _alignment_choice (Automatic)
 139         , _scrubbing (false)
 140         , _slaved (false)
 141         , loop_location (0)
 142         , overwrite_frame (0)
 143         , overwrite_offset (0)
 144         , _pending_overwrite (false)
 145         , overwrite_queued (false)
 146         , wrap_buffer_size (0)
 147         , speed_buffer_size (0)
 148         , _speed (1.0)
 149         , _target_speed (_speed)
 150         , file_frame (0)
 151         , playback_sample (0)
 152         , in_set_state (false)
 153         , _flags (Recordable)
 154         , deprecated_io_node (0)
 155 {
 156 }
 157
 158 Diskstream::~Diskstream ()
 159 {
 160         DEBUG_TRACE (DEBUG::Destruction, string_compose ("Diskstream %1 deleted\n", _name));
 161
 162         if (_playlist) {
 163                 _playlist->release ();
 164         }
 165
 166         delete deprecated_io_node;
 167 }
 168
 169 void
 170 Diskstream::set_track (Track* t)
 171 {
 172         _track = t;
 173         _io = _track->input();
 174
 175         ic_connection.disconnect();
 176         _io->changed.connect_same_thread (ic_connection, boost::bind (&Diskstream::handle_input_change, this, _1, _2));
 177
 178         if (_io->n_ports() != ChanCount::ZERO) {
 179                 input_change_pending.type = IOChange::Type (IOChange::ConfigurationChanged|IOChange::ConnectionsChanged);
 180                 non_realtime_input_change ();
 181         }
 182
 183         _track->Destroyed.connect_same_thread (*this, boost::bind (&Diskstream::route_going_away, this));
 184 }
 185
 186 void
 187 Diskstream::handle_input_change (IOChange change, void * /*src*/)
 188 {
 189         Glib::Mutex::Lock lm (state_lock);
 190
 191         if (change.type & (IOChange::ConfigurationChanged|IOChange::ConnectionsChanged)) {
 192
 193                 /* rather than handle this here on a DS-by-DS basis we defer to the
 194                    session transport/butler thread, and let it tackle
 195                    as many diskstreams as need it in one shot. this avoids many repeated
 196                    takings of the audioengine process lock.
 197                 */
 198
 199                 if (!(input_change_pending.type & change.type)) {
 200                         input_change_pending.type = IOChange::Type (input_change_pending.type | change.type);
 201                         _session.request_input_change_handling ();
 202                 }
 203         }
 204 }
 205
 206 void
 207 Diskstream::non_realtime_set_speed ()
 208 {
 209         if (_buffer_reallocation_required)
 210         {
 211                 Glib::Mutex::Lock lm (state_lock);
 212                 allocate_temporary_buffers ();
 213
 214                 _buffer_reallocation_required = false;
 215         }
 216
 217         if (_seek_required) {
 218                 if (speed() != 1.0f || speed() != -1.0f) {
 219                         seek ((framepos_t) (_session.transport_frame() * (double) speed()), true);
 220                 }
 221                 else {
 222                         seek (_session.transport_frame(), true);
 223                 }
 224
 225                 _seek_required = false;
 226         }
 227 }
 228
 229 bool
 230 Diskstream::realtime_set_speed (double sp, bool global)
 231 {
 232         bool changed = false;
 233         double new_speed = sp * _session.transport_speed();
 234
 235         if (_visible_speed != sp) {
 236                 _visible_speed = sp;
 237                 changed = true;
 238         }
 239
 240         if (new_speed != _actual_speed) {
 241
 242                 framecnt_t required_wrap_size = (framecnt_t) floor (_session.get_block_size() *
 243                                                                   fabs (new_speed)) + 1;
 244
 245                 if (required_wrap_size > wrap_buffer_size) {
 246                         _buffer_reallocation_required = true;
 247                 }
 248
 249                 _actual_speed = new_speed;
 250                 _target_speed = fabs(_actual_speed);
 251         }
 252
 253         if (changed) {
 254                 if (!global) {
 255                         _seek_required = true;
 256                 }
 257                 SpeedChanged (); /* EMIT SIGNAL */
 258         }
 259
 260         return _buffer_reallocation_required || _seek_required;
 261 }
 262
 263 void
 264 Diskstream::set_capture_offset ()
 265 {
 266         if (_io == 0) {
 267                 /* can't capture, so forget it */
 268                 return;
 269         }
 270
 271         _capture_offset = _io->latency();
 272         DEBUG_TRACE (DEBUG::CaptureAlignment, string_compose ("%1: using IO latency, capture offset set to %2\n", name(), _capture_offset));
 273 }
 274
 275
 276 void
 277 Diskstream::set_align_style (AlignStyle a, bool force)
 278 {
 279         if (record_enabled() && _session.actively_recording()) {
 280                 return;
 281         }
 282
 283         if ((a != _alignment_style) || force) {
 284                 _alignment_style = a;
 285                 AlignmentStyleChanged ();
 286         }
 287 }
 288
 289 void
 290 Diskstream::set_align_choice (AlignChoice a, bool force)
 291 {
 292         if (record_enabled() && _session.actively_recording()) {
 293                 return;
 294         }
 295
 296         if ((a != _alignment_choice) || force) {
 297                 _alignment_choice = a;
 298
 299                 switch (_alignment_choice) {
 300                 case Automatic:
 301                         set_align_style_from_io ();
 302                         break;
 303                 case UseExistingMaterial:
 304                         set_align_style (ExistingMaterial);
 305                         break;
 306                 case UseCaptureTime:
 307                         set_align_style (CaptureTime);
 308                         break;
 309                 }
 310         }
 311 }
 312
 313 int
 314 Diskstream::set_loop (Location *location)
 315 {
 316         if (location) {
 317                 if (location->start() >= location->end()) {
 318                         error << string_compose(_("Location \"%1\" not valid for track loop (start >= end)"), location->name()) << endl;
 319                         return -1;
 320                 }
 321         }
 322
 323         loop_location = location;
 324
 325         LoopSet (location); /* EMIT SIGNAL */
 326         return 0;
 327 }
 328
 329 /** Get the start position (in session frames) of the nth capture in the current pass */
 330 ARDOUR::framepos_t
 331 Diskstream::get_capture_start_frame (uint32_t n) const
 332 {
 333         Glib::Mutex::Lock lm (capture_info_lock);
 334
 335         if (capture_info.size() > n) {
 336                 /* this is a completed capture */
 337                 return capture_info[n]->start;
 338         } else {
 339                 /* this is the currently in-progress capture */
 340                 return capture_start_frame;
 341         }
 342 }
 343
 344 ARDOUR::framecnt_t
 345 Diskstream::get_captured_frames (uint32_t n) const
 346 {
 347         Glib::Mutex::Lock lm (capture_info_lock);
 348
 349         if (capture_info.size() > n) {
 350                 /* this is a completed capture */
 351                 return capture_info[n]->frames;
 352         } else {
 353                 /* this is the currently in-progress capture */
 354                 return capture_captured;
 355         }
 356 }
 357
 358 void
 359 Diskstream::set_roll_delay (ARDOUR::framecnt_t nframes)
 360 {
 361         _roll_delay = nframes;
 362 }
 363
 364 int
 365 Diskstream::use_playlist (boost::shared_ptr<Playlist> playlist)
 366 {
 367         if (!playlist) {
 368                 return 0;
 369         }
 370
 371         bool prior_playlist = false;
 372
 373         {
 374                 Glib::Mutex::Lock lm (state_lock);
 375
 376                 if (playlist == _playlist) {
 377                         return 0;
 378                 }
 379
 380                 playlist_connections.drop_connections ();
 381
 382                 if (_playlist) {
 383                         _playlist->release();
 384                         prior_playlist = true;
 385                 }
 386
 387                 _playlist = playlist;
 388                 _playlist->use();
 389
 390                 if (!in_set_state && recordable()) {
 391                         reset_write_sources (false);
 392                 }
 393
 394                 _playlist->ContentsChanged.connect_same_thread (playlist_connections, boost::bind (&Diskstream::playlist_modified, this));
 395                 _playlist->DropReferences.connect_same_thread (playlist_connections, boost::bind (&Diskstream::playlist_deleted, this, boost::weak_ptr<Playlist>(_playlist)));
 396                 _playlist->RangesMoved.connect_same_thread (playlist_connections, boost::bind (&Diskstream::playlist_ranges_moved, this, _1, _2));
 397         }
 398
 399         /* don't do this if we've already asked for it *or* if we are setting up
 400            the diskstream for the very first time - the input changed handling will
 401            take care of the buffer refill.
 402         */
 403
 404         if (!overwrite_queued && prior_playlist) {
 405                 _session.request_overwrite_buffer (_track);
 406                 overwrite_queued = true;
 407         }
 408
 409         PlaylistChanged (); /* EMIT SIGNAL */
 410         _session.set_dirty ();
 411
 412         return 0;
 413 }
 414
 415 void
 416 Diskstream::playlist_changed (const PropertyChange&)
 417 {
 418         playlist_modified ();
 419 }
 420
 421 void
 422 Diskstream::playlist_modified ()
 423 {
 424         if (!i_am_the_modifier && !overwrite_queued) {
 425                 _session.request_overwrite_buffer (_track);
 426                 overwrite_queued = true;
 427         }
 428 }
 429
 430 void
 431 Diskstream::playlist_deleted (boost::weak_ptr<Playlist> wpl)
 432 {
 433         boost::shared_ptr<Playlist> pl (wpl.lock());
 434
 435         if (pl == _playlist) {
 436
 437                 /* this catches an ordering issue with session destruction. playlists
 438                    are destroyed before diskstreams. we have to invalidate any handles
 439                    we have to the playlist.
 440                 */
 441
 442                 if (_playlist) {
 443                         _playlist.reset ();
 444                 }
 445         }
 446 }
 447
 448 bool
 449 Diskstream::set_name (const string& str)
 450 {
 451         if (_name != str) {
 452                 assert(playlist());
 453                 playlist()->set_name (str);
 454                 SessionObject::set_name(str);
 455         }
 456         return true;
 457 }
 458
 459 XMLNode&
 460 Diskstream::get_state ()
 461 {
 462         XMLNode* node = new XMLNode ("Diskstream");
 463         char buf[64];
 464         LocaleGuard lg (X_("POSIX"));
 465
 466         node->add_property ("flags", enum_2_string (_flags));
 467         node->add_property ("playlist", _playlist->name());
 468         node->add_property("name", _name);
 469         id().print (buf, sizeof (buf));
 470         node->add_property("id", buf);
 471         snprintf (buf, sizeof(buf), "%f", _visible_speed);
 472         node->add_property ("speed", buf);
 473         node->add_property ("capture-alignment", enum_2_string (_alignment_choice));
 474
 475         if (_extra_xml) {
 476                 node->add_child_copy (*_extra_xml);
 477         }
 478
 479         return *node;
 480 }
 481
 482 int
 483 Diskstream::set_state (const XMLNode& node, int /*version*/)
 484 {
 485         const XMLProperty* prop;
 486
 487         if ((prop = node.property ("name")) != 0) {
 488                 _name = prop->value();
 489         }
 490
 491         if (deprecated_io_node) {
 492                 set_id (*deprecated_io_node);
 493         } else {
 494                 set_id (node);
 495         }
 496
 497         if ((prop = node.property ("flags")) != 0) {
 498                 _flags = Flag (string_2_enum (prop->value(), _flags));
 499         }
 500
 501         if ((prop = node.property (X_("capture-alignment"))) != 0) {
 502                 set_align_choice (AlignChoice (string_2_enum (prop->value(), _alignment_choice)), true);
 503         } else {
 504                 set_align_choice (Automatic, true);
 505         }
 506
 507         if ((prop = node.property ("playlist")) == 0) {
 508                 return -1;
 509         }
 510
 511         {
 512                 bool had_playlist = (_playlist != 0);
 513
 514                 if (find_and_use_playlist (prop->value())) {
 515                         return -1;
 516                 }
 517
 518                 if (!had_playlist) {
 519                         _playlist->set_orig_diskstream_id (id());
 520                 }
 521         }
 522
 523         if ((prop = node.property ("speed")) != 0) {
 524                 double sp = atof (prop->value().c_str());
 525
 526                 if (realtime_set_speed (sp, false)) {
 527                         non_realtime_set_speed ();
 528                 }
 529         }
 530
 531         return 0;
 532 }
 533
 534 void
 535 Diskstream::playlist_ranges_moved (list< Evoral::RangeMove<framepos_t> > const & movements_frames, bool from_undo)
 536 {
 537         /* If we're coming from an undo, it will have handled
 538            automation undo (it must, since automation-follows-regions
 539            can lose automation data).  Hence we can do nothing here.
 540         */
 541
 542         if (from_undo) {
 543                 return;
 544         }
 545
 546         if (!_track || Config->get_automation_follows_regions () == false) {
 547                 return;
 548         }
 549
 550         list< Evoral::RangeMove<double> > movements;
 551
 552         for (list< Evoral::RangeMove<framepos_t> >::const_iterator i = movements_frames.begin();
 553              i != movements_frames.end();
 554              ++i) {
 555
 556                 movements.push_back(Evoral::RangeMove<double>(i->from, i->length, i->to));
 557         }
 558
 559         /* move panner automation */
 560         boost::shared_ptr<Pannable> pannable = _track->pannable();
 561         Evoral::ControlSet::Controls& c (pannable->controls());
 562
 563         for (Evoral::ControlSet::Controls::iterator ci = c.begin(); ci != c.end(); ++ci) {
 564                 boost::shared_ptr<AutomationControl> ac = boost::dynamic_pointer_cast<AutomationControl>(ci->second);
 565                 if (!ac) {
 566                         continue;
 567                 }
 568                 boost::shared_ptr<AutomationList> alist = ac->alist();
 569
 570                 XMLNode & before = alist->get_state ();
 571                 bool const things_moved = alist->move_ranges (movements);
 572                 if (things_moved) {
 573                         _session.add_command (new MementoCommand<AutomationList> (
 574                                                       *alist.get(), &before, &alist->get_state ()));
 575                 }
 576         }
 577
 578         /* move processor automation */
 579         _track->foreach_processor (boost::bind (&Diskstream::move_processor_automation, this, _1, movements_frames));
 580 }
 581
 582 void
 583 Diskstream::move_processor_automation (boost::weak_ptr<Processor> p, list< Evoral::RangeMove<framepos_t> > const & movements_frames)
 584 {
 585         boost::shared_ptr<Processor> processor (p.lock ());
 586         if (!processor) {
 587                 return;
 588         }
 589
 590         list< Evoral::RangeMove<double> > movements;
 591         for (list< Evoral::RangeMove<framepos_t> >::const_iterator i = movements_frames.begin(); i != movements_frames.end(); ++i) {
 592                 movements.push_back(Evoral::RangeMove<double>(i->from, i->length, i->to));
 593         }
 594
 595         set<Evoral::Parameter> const a = processor->what_can_be_automated ();
 596
 597         for (set<Evoral::Parameter>::iterator i = a.begin (); i != a.end (); ++i) {
 598                 boost::shared_ptr<AutomationList> al = processor->automation_control(*i)->alist();
 599                 XMLNode & before = al->get_state ();
 600                 bool const things_moved = al->move_ranges (movements);
 601                 if (things_moved) {
 602                         _session.add_command (
 603                                 new MementoCommand<AutomationList> (
 604                                         *al.get(), &before, &al->get_state ()
 605                                         )
 606                                 );
 607                 }
 608         }
 609 }
 610
 611 void
 612 Diskstream::check_record_status (framepos_t transport_frame, bool can_record)
 613 {
 614         int possibly_recording;
 615         int rolling;
 616         int change;
 617         const int transport_rolling = 0x4;
 618         const int track_rec_enabled = 0x2;
 619         const int global_rec_enabled = 0x1;
 620         const int fully_rec_enabled = (transport_rolling|track_rec_enabled|global_rec_enabled);
 621
 622         /* merge together the 3 factors that affect record status, and compute
 623            what has changed.
 624         */
 625
 626         rolling = _session.transport_speed() != 0.0f;
 627         possibly_recording = (rolling << 2) | (record_enabled() << 1) | can_record;
 628         change = possibly_recording ^ last_possibly_recording;
 629
 630         if (possibly_recording == last_possibly_recording) {
 631                 return;
 632         }
 633
 634         framecnt_t existing_material_offset = _session.worst_playback_latency();
 635
 636         if (possibly_recording == fully_rec_enabled) {
 637
 638                 if (last_possibly_recording == fully_rec_enabled) {
 639                         return;
 640                 }
 641
 642                 capture_start_frame = _session.transport_frame();
 643                 first_recordable_frame = capture_start_frame + _capture_offset;
 644                 last_recordable_frame = max_framepos;
 645
 646                 DEBUG_TRACE (DEBUG::CaptureAlignment, string_compose ("%1: @ %7 (%9) FRF = %2 CSF = %4 CO = %5, EMO = %6 RD = %8 WOL %10 WTL %11\n",
 647                                                                       name(), first_recordable_frame, last_recordable_frame, capture_start_frame,
 648                                                                       _capture_offset,
 649                                                                       existing_material_offset,
 650                                                                       transport_frame,
 651                                                                       _roll_delay,
 652                                                                       _session.transport_frame(),
 653                                                                       _session.worst_output_latency(),
 654                                                                       _session.worst_track_latency()));
 655
 656
 657                 if (_alignment_style == ExistingMaterial) {
 658                         first_recordable_frame += existing_material_offset;
 659                         DEBUG_TRACE (DEBUG::CaptureAlignment, string_compose ("\tshift FRF by EMO %1\n",
 660                                                                               first_recordable_frame));
 661                 }
 662
 663                 prepare_record_status (capture_start_frame);
 664
 665         } else {
 666
 667                 if (last_possibly_recording == fully_rec_enabled) {
 668
 669                         /* we were recording last time */
 670
 671                         if (change & transport_rolling) {
 672
 673                                 /* transport-change (stopped rolling): last_recordable_frame was set in ::prepare_to_stop(). We
 674                                    had to set it there because we likely rolled past the stopping point to declick out,
 675                                    and then backed up.
 676                                  */
 677
 678                         } else {
 679                                 /* punch out */
 680
 681                                 last_recordable_frame = _session.transport_frame() + _capture_offset;
 682
 683                                 if (_alignment_style == ExistingMaterial) {
 684                                         last_recordable_frame += existing_material_offset;
 685                                 }
 686                         }
 687                 }
 688         }
 689
 690         last_possibly_recording = possibly_recording;
 691 }
 692
 693 void
 694 Diskstream::route_going_away ()
 695 {
 696         _io.reset ();
 697 }
 698
 699 void
 700 Diskstream::calculate_record_range(OverlapType ot, framepos_t transport_frame, framecnt_t nframes,
 701                                    framecnt_t & rec_nframes, framecnt_t & rec_offset)
 702 {
 703         switch (ot) {
 704         case OverlapNone:
 705                 rec_nframes = 0;
 706                 break;
 707
 708         case OverlapInternal:
 709                 /*     ----------    recrange
 710                          |---|       transrange
 711                 */
 712                 rec_nframes = nframes;
 713                 rec_offset = 0;
 714                 break;
 715
 716         case OverlapStart:
 717                 /*    |--------|    recrange
 718                 -----|          transrange
 719                 */
 720                 rec_nframes = transport_frame + nframes - first_recordable_frame;
 721                 if (rec_nframes) {
 722                         rec_offset = first_recordable_frame - transport_frame;
 723                 }
 724                 break;
 725
 726         case OverlapEnd:
 727                 /*    |--------|    recrange
 728                          |--------  transrange
 729                 */
 730                 rec_nframes = last_recordable_frame - transport_frame;
 731                 rec_offset = 0;
 732                 break;
 733
 734         case OverlapExternal:
 735                 /*    |--------|    recrange
 736                     --------------  transrange
 737                 */
 738                 rec_nframes = last_recordable_frame - first_recordable_frame;
 739                 rec_offset = first_recordable_frame - transport_frame;
 740                 break;
 741         }
 742
 743         DEBUG_TRACE (DEBUG::CaptureAlignment, string_compose ("%1 rec? %2 @ %3 (for %4) FRF %5 LRF %6 : rf %7 @ %8\n",
 744                                                               _name, enum_2_string (ot), transport_frame, nframes,
 745                                                               first_recordable_frame, last_recordable_frame, rec_nframes, rec_offset));
 746 }
 747
 748 void
 749 Diskstream::prepare_to_stop (framepos_t pos)
 750 {
 751         last_recordable_frame = pos + _capture_offset;
 752 }