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