src/wx/film_viewer.cc

   1 /*
   2     Copyright (C) 2012-2019 Carl Hetherington <cth@carlh.net>
   3
   4     This file is part of DCP-o-matic.
   5
   6     DCP-o-matic is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     DCP-o-matic is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 */
  20
  21 /** @file  src/film_viewer.cc
  22  *  @brief A wx widget to view a preview of a Film.
  23  */
  24
  25 #include "film_viewer.h"
  26 #include "playhead_to_timecode_dialog.h"
  27 #include "playhead_to_frame_dialog.h"
  28 #include "wx_util.h"
  29 #include "closed_captions_dialog.h"
  30 #include "lib/film.h"
  31 #include "lib/ratio.h"
  32 #include "lib/util.h"
  33 #include "lib/job_manager.h"
  34 #include "lib/image.h"
  35 #include "lib/exceptions.h"
  36 #include "lib/examine_content_job.h"
  37 #include "lib/filter.h"
  38 #include "lib/player.h"
  39 #include "lib/player_video.h"
  40 #include "lib/video_content.h"
  41 #include "lib/video_decoder.h"
  42 #include "lib/timer.h"
  43 #include "lib/butler.h"
  44 #include "lib/log.h"
  45 #include "lib/config.h"
  46 #include "lib/compose.hpp"
  47 #include "lib/dcpomatic_log.h"
  48 #include "lib/text_content.h"
  49 extern "C" {
  50 #include <libavutil/pixfmt.h>
  51 }
  52 #include <dcp/exceptions.h>
  53 #include <wx/tglbtn.h>
  54 #include <iostream>
  55 #include <iomanip>
  56
  57 using std::string;
  58 using std::pair;
  59 using std::min;
  60 using std::max;
  61 using std::cout;
  62 using std::list;
  63 using std::bad_alloc;
  64 using std::make_pair;
  65 using std::exception;
  66 using boost::shared_ptr;
  67 using boost::dynamic_pointer_cast;
  68 using boost::weak_ptr;
  69 using boost::optional;
  70 using dcp::Size;
  71
  72 static
  73 int
  74 rtaudio_callback (void* out, void *, unsigned int frames, double, RtAudioStreamStatus, void* data)
  75 {
  76         return reinterpret_cast<FilmViewer*>(data)->audio_callback (out, frames);
  77 }
  78
  79 FilmViewer::FilmViewer (wxWindow* p)
  80         : _panel (new wxPanel (p))
  81         , _coalesce_player_changes (false)
  82         , _audio (DCPOMATIC_RTAUDIO_API)
  83         , _audio_channels (0)
  84         , _audio_block_size (1024)
  85         , _playing (false)
  86         , _latency_history_count (0)
  87         , _dropped (0)
  88         , _closed_captions_dialog (new ClosedCaptionsDialog(p, this))
  89         , _outline_content (false)
  90         , _eyes (EYES_LEFT)
  91         , _pad_black (false)
  92 #ifdef DCPOMATIC_VARIANT_SWAROOP
  93         , _in_watermark (false)
  94         , _background_image (false)
  95 #endif
  96 {
  97 #ifndef __WXOSX__
  98         _panel->SetDoubleBuffered (true);
  99 #endif
 100
 101         _panel->SetBackgroundStyle (wxBG_STYLE_PAINT);
 102         _panel->SetBackgroundColour (*wxBLACK);
 103
 104         _panel->Bind (wxEVT_PAINT, boost::bind (&FilmViewer::paint_panel, this));
 105         _panel->Bind (wxEVT_SIZE,  boost::bind (&FilmViewer::panel_sized, this, _1));
 106         _timer.Bind  (wxEVT_TIMER, boost::bind (&FilmViewer::timer, this));
 107
 108         set_film (shared_ptr<Film> ());
 109
 110         _config_changed_connection = Config::instance()->Changed.connect (bind (&FilmViewer::config_changed, this, _1));
 111         config_changed (Config::SOUND_OUTPUT);
 112 }
 113
 114 FilmViewer::~FilmViewer ()
 115 {
 116         stop ();
 117 }
 118
 119 void
 120 FilmViewer::set_film (shared_ptr<Film> film)
 121 {
 122         if (_film == film) {
 123                 return;
 124         }
 125
 126         _film = film;
 127         _video_position = DCPTime ();
 128         _player_video.first.reset ();
 129         _player_video.second = DCPTime ();
 130
 131         _frame.reset ();
 132         _closed_captions_dialog->clear ();
 133
 134         if (!_film) {
 135                 _player.reset ();
 136                 recreate_butler ();
 137                 _frame.reset ();
 138                 refresh_panel ();
 139                 return;
 140         }
 141
 142         try {
 143                 _player.reset (new Player (_film, _film->playlist ()));
 144                 _player->set_fast ();
 145                 if (_dcp_decode_reduction) {
 146                         _player->set_dcp_decode_reduction (_dcp_decode_reduction);
 147                 }
 148         } catch (bad_alloc &) {
 149                 error_dialog (_panel, _("There is not enough free memory to do that."));
 150                 _film.reset ();
 151                 return;
 152         }
 153
 154         _player->set_always_burn_open_subtitles ();
 155         _player->set_play_referenced ();
 156
 157         _film->Change.connect (boost::bind (&FilmViewer::film_change, this, _1, _2));
 158         _film->ContentChange.connect (boost::bind(&FilmViewer::content_change, this, _1, _3));
 159         _player->Change.connect (boost::bind (&FilmViewer::player_change, this, _1, _2, _3));
 160
 161         /* Keep about 1 second's worth of history samples */
 162         _latency_history_count = _film->audio_frame_rate() / _audio_block_size;
 163
 164         recreate_butler ();
 165
 166         calculate_sizes ();
 167         slow_refresh ();
 168 }
 169
 170 void
 171 FilmViewer::recreate_butler ()
 172 {
 173         bool const was_running = stop ();
 174         _butler.reset ();
 175
 176         if (!_film) {
 177                 return;
 178         }
 179
 180         AudioMapping map = AudioMapping (_film->audio_channels(), _audio_channels);
 181
 182         if (_audio_channels != 2 || _film->audio_channels() < 3) {
 183                 for (int i = 0; i < min (_film->audio_channels(), _audio_channels); ++i) {
 184                         map.set (i, i, 1);
 185                 }
 186         } else {
 187                 /* Special case: stereo output, at least 3 channel input.
 188                    Map so that Lt = L(-3dB) + Ls(-3dB) + C(-6dB) + Lfe(-10dB)
 189                                Rt = R(-3dB) + Rs(-3dB) + C(-6dB) + Lfe(-10dB)
 190                 */
 191                 if (_film->audio_channels() > 0) {
 192                         map.set (dcp::LEFT,   0, 1 / sqrt(2)); // L -> Lt
 193                 }
 194                 if (_film->audio_channels() > 1) {
 195                         map.set (dcp::RIGHT,  1, 1 / sqrt(2)); // R -> Rt
 196                 }
 197                 if (_film->audio_channels() > 2) {
 198                         map.set (dcp::CENTRE, 0, 1 / 2.0); // C -> Lt
 199                         map.set (dcp::CENTRE, 1, 1 / 2.0); // C -> Rt
 200                 }
 201                 if (_film->audio_channels() > 3) {
 202                         map.set (dcp::LFE,    0, 1 / sqrt(10)); // Lfe -> Lt
 203                         map.set (dcp::LFE,    1, 1 / sqrt(10)); // Lfe -> Rt
 204                 }
 205                 if (_film->audio_channels() > 4) {
 206                         map.set (dcp::LS,     0, 1 / sqrt(2)); // Ls -> Lt
 207                 }
 208                 if (_film->audio_channels() > 5) {
 209                         map.set (dcp::RS,     1, 1 / sqrt(2)); // Rs -> Rt
 210                 }
 211         }
 212
 213         _butler.reset (new Butler(_player, map, _audio_channels, bind(&PlayerVideo::force, _1, AV_PIX_FMT_RGB24), false, true));
 214         if (!Config::instance()->sound() && !_audio.isStreamOpen()) {
 215                 _butler->disable_audio ();
 216         }
 217
 218         _closed_captions_dialog->set_butler (_butler);
 219
 220         if (was_running) {
 221                 start ();
 222         }
 223 }
 224
 225 void
 226 FilmViewer::refresh_panel ()
 227 {
 228         _panel->Refresh ();
 229         _panel->Update ();
 230 }
 231
 232 void
 233 FilmViewer::get ()
 234 {
 235         DCPOMATIC_ASSERT (_butler);
 236
 237         do {
 238                 Butler::Error e;
 239                 _player_video = _butler->get_video (&e);
 240                 if (!_player_video.first && e == Butler::AGAIN) {
 241                         signal_manager->when_idle (boost::bind(&FilmViewer::get, this));
 242                         return;
 243                 }
 244         } while (
 245                 _player_video.first &&
 246                 _film->three_d() &&
 247                 _eyes != _player_video.first->eyes() &&
 248                 _player_video.first->eyes() != EYES_BOTH
 249                 );
 250
 251         try {
 252                 _butler->rethrow ();
 253         } catch (DecodeError& e) {
 254                 error_dialog (_panel, e.what());
 255         }
 256
 257         display_player_video ();
 258 }
 259
 260 void
 261 FilmViewer::display_player_video ()
 262 {
 263         if (!_player_video.first) {
 264                 _frame.reset ();
 265                 refresh_panel ();
 266                 return;
 267         }
 268
 269         if (_playing && (time() - _player_video.second) > one_video_frame()) {
 270                 /* Too late; just drop this frame before we try to get its image (which will be the time-consuming
 271                    part if this frame is J2K).
 272                 */
 273                 _video_position = _player_video.second;
 274                 ++_dropped;
 275                 return;
 276         }
 277
 278         /* In an ideal world, what we would do here is:
 279          *
 280          * 1. convert to XYZ exactly as we do in the DCP creation path.
 281          * 2. convert back to RGB for the preview display, compensating
 282          *    for the monitor etc. etc.
 283          *
 284          * but this is inefficient if the source is RGB.  Since we don't
 285          * (currently) care too much about the precise accuracy of the preview's
 286          * colour mapping (and we care more about its speed) we try to short-
 287          * circuit this "ideal" situation in some cases.
 288          *
 289          * The content's specified colour conversion indicates the colourspace
 290          * which the content is in (according to the user).
 291          *
 292          * PlayerVideo::image (bound to PlayerVideo::force) will take the source
 293          * image and convert it (from whatever the user has said it is) to RGB.
 294          */
 295
 296         _frame = _player_video.first->image (bind(&PlayerVideo::force, _1, AV_PIX_FMT_RGB24), false, true);
 297
 298         ImageChanged (_player_video.first);
 299
 300         _video_position = _player_video.second;
 301         _inter_position = _player_video.first->inter_position ();
 302         _inter_size = _player_video.first->inter_size ();
 303
 304         refresh_panel ();
 305
 306         _closed_captions_dialog->update (time());
 307 }
 308
 309 void
 310 FilmViewer::timer ()
 311 {
 312         if (!_film || !_playing) {
 313                 return;
 314         }
 315
 316         get ();
 317         PositionChanged ();
 318         DCPTime const next = _video_position + one_video_frame();
 319
 320         if (next >= _film->length()) {
 321                 stop ();
 322                 Finished ();
 323                 return;
 324         }
 325
 326         LOG_DEBUG_PLAYER("%1 -> %2; delay %3", next.seconds(), time().seconds(), max((next.seconds() - time().seconds()) * 1000, 1.0));
 327         _timer.Start (max ((next.seconds() - time().seconds()) * 1000, 1.0), wxTIMER_ONE_SHOT);
 328
 329         if (_butler) {
 330                 _butler->rethrow ();
 331         }
 332 }
 333
 334 bool
 335 #ifdef DCPOMATIC_VARIANT_SWAROOP
 336 FilmViewer::maybe_draw_background_image (wxPaintDC& dc)
 337 {
 338         optional<boost::filesystem::path> bg = Config::instance()->player_background_image();
 339         if (bg) {
 340                 wxImage image (std_to_wx(bg->string()));
 341                 wxBitmap bitmap (image);
 342                 dc.DrawBitmap (bitmap, max(0, (_panel_size.width - image.GetSize().GetWidth()) / 2), max(0, (_panel_size.height - image.GetSize().GetHeight()) / 2));
 343                 return true;
 344         }
 345
 346         return false;
 347 }
 348 #else
 349 FilmViewer::maybe_draw_background_image (wxPaintDC &)
 350 {
 351         return false;
 352 }
 353 #endif
 354
 355 void
 356 FilmViewer::paint_panel ()
 357 {
 358         wxPaintDC dc (_panel);
 359
 360 #ifdef DCPOMATIC_VARIANT_SWAROOP
 361         if (_background_image) {
 362                 dc.Clear ();
 363                 maybe_draw_background_image (dc);
 364                 return;
 365         }
 366 #endif
 367
 368         if (!_out_size.width || !_out_size.height || !_film || !_frame || _out_size != _frame->size()) {
 369                 dc.Clear ();
 370         } else {
 371
 372                 wxImage frame (_out_size.width, _out_size.height, _frame->data()[0], true);
 373                 wxBitmap frame_bitmap (frame);
 374                 dc.DrawBitmap (frame_bitmap, 0, max(0, (_panel_size.height - _out_size.height) / 2));
 375
 376 #ifdef DCPOMATIC_VARIANT_SWAROOP
 377                 DCPTime const period = DCPTime::from_seconds(Config::instance()->player_watermark_period() * 60);
 378                 int64_t n = _video_position.get() / period.get();
 379                 DCPTime from(n * period.get());
 380                 DCPTime to = from + DCPTime::from_seconds(Config::instance()->player_watermark_duration() / 1000.0);
 381                 if (from <= _video_position && _video_position <= to) {
 382                         if (!_in_watermark) {
 383                                 _in_watermark = true;
 384                                 _watermark_x = rand() % _panel_size.width;
 385                                 _watermark_y = rand() % _panel_size.height;
 386                         }
 387                         dc.SetTextForeground(*wxWHITE);
 388                         string wm = Config::instance()->player_watermark_theatre();
 389                         boost::posix_time::ptime t = boost::posix_time::second_clock::local_time();
 390                         wm += "\n" + boost::posix_time::to_iso_extended_string(t);
 391                         dc.DrawText(std_to_wx(wm), _watermark_x, _watermark_y);
 392                 } else {
 393                         _in_watermark = false;
 394                 }
 395 #endif
 396         }
 397
 398         if (_out_size.width < _panel_size.width) {
 399                 /* XXX: these colours are right for GNOME; may need adjusting for other OS */
 400                 wxPen   p (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 401                 wxBrush b (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 402                 dc.SetPen (p);
 403                 dc.SetBrush (b);
 404                 dc.DrawRectangle (_out_size.width, 0, _panel_size.width - _out_size.width, _panel_size.height);
 405         }
 406
 407         if (_out_size.height < _panel_size.height) {
 408                 wxPen   p (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 409                 wxBrush b (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 410                 dc.SetPen (p);
 411                 dc.SetBrush (b);
 412                 int const gap = (_panel_size.height - _out_size.height) / 2;
 413                 dc.DrawRectangle (0, 0, _panel_size.width, gap);
 414                 dc.DrawRectangle (0, gap + _out_size.height + 1, _panel_size.width, gap + 1);
 415         }
 416
 417         if (_outline_content) {
 418                 wxPen p (wxColour (255, 0, 0), 2);
 419                 dc.SetPen (p);
 420                 dc.SetBrush (*wxTRANSPARENT_BRUSH);
 421                 dc.DrawRectangle (_inter_position.x, _inter_position.y + (_panel_size.height - _out_size.height) / 2, _inter_size.width, _inter_size.height);
 422         }
 423 }
 424
 425 void
 426 FilmViewer::set_outline_content (bool o)
 427 {
 428         _outline_content = o;
 429         refresh_panel ();
 430 }
 431
 432 void
 433 FilmViewer::set_eyes (Eyes e)
 434 {
 435         _eyes = e;
 436         slow_refresh ();
 437 }
 438
 439 void
 440 FilmViewer::panel_sized (wxSizeEvent& ev)
 441 {
 442         _panel_size.width = ev.GetSize().GetWidth();
 443         _panel_size.height = ev.GetSize().GetHeight();
 444
 445         calculate_sizes ();
 446         if (!quick_refresh()) {
 447                 slow_refresh ();
 448         }
 449         PositionChanged ();
 450 }
 451
 452 void
 453 FilmViewer::calculate_sizes ()
 454 {
 455         if (!_film || !_player) {
 456                 return;
 457         }
 458
 459         Ratio const * container = _film->container ();
 460
 461         float const panel_ratio = _panel_size.ratio ();
 462         float const film_ratio = container ? container->ratio () : 1.78;
 463
 464         if (panel_ratio < film_ratio) {
 465                 /* panel is less widscreen than the film; clamp width */
 466                 _out_size.width = _panel_size.width;
 467                 _out_size.height = lrintf (_out_size.width / film_ratio);
 468         } else {
 469                 /* panel is more widescreen than the film; clamp height */
 470                 _out_size.height = _panel_size.height;
 471                 _out_size.width = lrintf (_out_size.height * film_ratio);
 472         }
 473
 474         /* Catch silly values */
 475         _out_size.width = max (64, _out_size.width);
 476         _out_size.height = max (64, _out_size.height);
 477
 478         _player->set_video_container_size (_out_size);
 479 }
 480
 481 void
 482 FilmViewer::start ()
 483 {
 484         if (!_film) {
 485                 return;
 486         }
 487
 488         optional<bool> v = PlaybackPermitted ();
 489         if (v && !*v) {
 490                 /* Computer says no */
 491                 return;
 492         }
 493
 494         if (_audio.isStreamOpen()) {
 495                 _audio.setStreamTime (_video_position.seconds());
 496                 _audio.startStream ();
 497         }
 498
 499         _playing = true;
 500         _dropped = 0;
 501         timer ();
 502         Started (position());
 503 }
 504
 505 bool
 506 FilmViewer::stop ()
 507 {
 508         if (_audio.isStreamRunning()) {
 509                 /* stop stream and discard any remaining queued samples */
 510                 _audio.abortStream ();
 511         }
 512
 513         if (!_playing) {
 514                 return false;
 515         }
 516
 517         _playing = false;
 518         Stopped (position());
 519         return true;
 520 }
 521
 522 void
 523 FilmViewer::player_change (ChangeType type, int property, bool frequent)
 524 {
 525         if (type != CHANGE_TYPE_DONE || frequent) {
 526                 return;
 527         }
 528
 529         if (_coalesce_player_changes) {
 530                 _pending_player_changes.push_back (property);
 531                 return;
 532         }
 533
 534         calculate_sizes ();
 535         bool refreshed = false;
 536         if (
 537                 property == VideoContentProperty::CROP ||
 538                 property == VideoContentProperty::SCALE ||
 539                 property == VideoContentProperty::FADE_IN ||
 540                 property == VideoContentProperty::FADE_OUT ||
 541                 property == VideoContentProperty::COLOUR_CONVERSION ||
 542                 property == PlayerProperty::VIDEO_CONTAINER_SIZE ||
 543                 property == PlayerProperty::FILM_CONTAINER
 544                 ) {
 545                 refreshed = quick_refresh ();
 546         }
 547
 548         if (!refreshed) {
 549                 slow_refresh ();
 550         }
 551         PositionChanged ();
 552 }
 553
 554 void
 555 FilmViewer::film_change (ChangeType type, Film::Property p)
 556 {
 557         if (type == CHANGE_TYPE_DONE && p == Film::AUDIO_CHANNELS) {
 558                 recreate_butler ();
 559         } else if (p == Film::CONTENT) {
 560                 _closed_captions_dialog->update_tracks (_film);
 561         }
 562 }
 563
 564 /** Re-get the current frame slowly by seeking */
 565 void
 566 FilmViewer::slow_refresh ()
 567 {
 568         seek (_video_position, true);
 569 }
 570
 571 /** Try to re-get the current frame quickly by resetting the metadata
 572  *  in the PlayerVideo that we used last time.
 573  *  @return true if this was possible, false if not.
 574  */
 575 bool
 576 FilmViewer::quick_refresh ()
 577 {
 578         if (!_player_video.first) {
 579                 return false;
 580         }
 581
 582         if (!_player_video.first->reset_metadata (_film, _player->video_container_size(), _film->frame_size())) {
 583                 return false;
 584         }
 585
 586         display_player_video ();
 587         return true;
 588 }
 589
 590 void
 591 FilmViewer::seek (shared_ptr<Content> content, ContentTime t, bool accurate)
 592 {
 593         optional<DCPTime> dt = _player->content_time_to_dcp (content, t);
 594         if (dt) {
 595                 seek (*dt, accurate);
 596         }
 597 }
 598
 599 void
 600 FilmViewer::set_coalesce_player_changes (bool c)
 601 {
 602         _coalesce_player_changes = c;
 603
 604         if (!c) {
 605                 BOOST_FOREACH (int i, _pending_player_changes) {
 606                         player_change (CHANGE_TYPE_DONE, i, false);
 607                 }
 608                 _pending_player_changes.clear ();
 609         }
 610 }
 611
 612 void
 613 FilmViewer::seek (DCPTime t, bool accurate)
 614 {
 615         if (!_butler) {
 616                 return;
 617         }
 618
 619         if (t < DCPTime ()) {
 620                 t = DCPTime ();
 621         }
 622
 623         if (t >= _film->length ()) {
 624                 t = _film->length ();
 625         }
 626
 627         bool const was_running = stop ();
 628
 629         _closed_captions_dialog->clear ();
 630         _butler->seek (t, accurate);
 631         get ();
 632
 633         if (was_running) {
 634                 start ();
 635         }
 636
 637         PositionChanged ();
 638 }
 639
 640 void
 641 FilmViewer::config_changed (Config::Property p)
 642 {
 643 #ifdef DCPOMATIC_VARIANT_SWAROOP
 644         if (p == Config::PLAYER_BACKGROUND_IMAGE) {
 645                 refresh_panel ();
 646                 return;
 647         }
 648 #endif
 649
 650         if (p != Config::SOUND && p != Config::SOUND_OUTPUT) {
 651                 return;
 652         }
 653
 654         if (_audio.isStreamOpen ()) {
 655                 _audio.closeStream ();
 656         }
 657
 658         if (Config::instance()->sound() && _audio.getDeviceCount() > 0) {
 659                 unsigned int st = 0;
 660                 if (Config::instance()->sound_output()) {
 661                         while (st < _audio.getDeviceCount()) {
 662                                 if (_audio.getDeviceInfo(st).name == Config::instance()->sound_output().get()) {
 663                                         break;
 664                                 }
 665                                 ++st;
 666                         }
 667                         if (st == _audio.getDeviceCount()) {
 668                                 st = _audio.getDefaultOutputDevice();
 669                         }
 670                 } else {
 671                         st = _audio.getDefaultOutputDevice();
 672                 }
 673
 674                 _audio_channels = _audio.getDeviceInfo(st).outputChannels;
 675
 676                 RtAudio::StreamParameters sp;
 677                 sp.deviceId = st;
 678                 sp.nChannels = _audio_channels;
 679                 sp.firstChannel = 0;
 680                 try {
 681                         _audio.openStream (&sp, 0, RTAUDIO_FLOAT32, 48000, &_audio_block_size, &rtaudio_callback, this);
 682 #ifdef DCPOMATIC_USE_RTERROR
 683                 } catch (RtError& e) {
 684 #else
 685                 } catch (RtAudioError& e) {
 686 #endif
 687                         error_dialog (
 688                                 _panel,
 689                                 _("Could not set up audio output.  There will be no audio during the preview."), std_to_wx(e.what())
 690                                 );
 691                 }
 692                 recreate_butler ();
 693
 694         } else {
 695                 _audio_channels = 0;
 696                 recreate_butler ();
 697         }
 698 }
 699
 700 DCPTime
 701 FilmViewer::uncorrected_time () const
 702 {
 703         if (_audio.isStreamRunning ()) {
 704                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime());
 705         }
 706
 707         return _video_position;
 708 }
 709
 710 DCPTime
 711 FilmViewer::time () const
 712 {
 713         if (_audio.isStreamRunning ()) {
 714                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime ()) -
 715                         DCPTime::from_frames (average_latency(), _film->audio_frame_rate());
 716         }
 717
 718         return _video_position;
 719 }
 720
 721 int
 722 FilmViewer::audio_callback (void* out_p, unsigned int frames)
 723 {
 724         while (true) {
 725                 optional<DCPTime> t = _butler->get_audio (reinterpret_cast<float*> (out_p), frames);
 726                 if (!t || DCPTime(uncorrected_time() - *t) < one_video_frame()) {
 727                         /* There was an underrun or this audio is on time; carry on */
 728                         break;
 729                 }
 730                 /* The audio we just got was (very) late; drop it and get some more. */
 731         }
 732
 733         boost::mutex::scoped_lock lm (_latency_history_mutex, boost::try_to_lock);
 734         if (lm) {
 735                 _latency_history.push_back (_audio.getStreamLatency ());
 736                 if (_latency_history.size() > static_cast<size_t> (_latency_history_count)) {
 737                         _latency_history.pop_front ();
 738                 }
 739         }
 740
 741         return 0;
 742 }
 743
 744 Frame
 745 FilmViewer::average_latency () const
 746 {
 747         boost::mutex::scoped_lock lm (_latency_history_mutex);
 748         if (_latency_history.empty()) {
 749                 return 0;
 750         }
 751
 752         Frame total = 0;
 753         BOOST_FOREACH (Frame i, _latency_history) {
 754                 total += i;
 755         }
 756
 757         return total / _latency_history.size();
 758 }
 759
 760 void
 761 FilmViewer::set_dcp_decode_reduction (optional<int> reduction)
 762 {
 763         _dcp_decode_reduction = reduction;
 764         if (_player) {
 765                 _player->set_dcp_decode_reduction (reduction);
 766         }
 767 }
 768
 769 optional<int>
 770 FilmViewer::dcp_decode_reduction () const
 771 {
 772         return _dcp_decode_reduction;
 773 }
 774
 775 DCPTime
 776 FilmViewer::one_video_frame () const
 777 {
 778         return DCPTime::from_frames (1, _film->video_frame_rate());
 779 }
 780
 781 /** Open a dialog box showing our film's closed captions */
 782 void
 783 FilmViewer::show_closed_captions ()
 784 {
 785         _closed_captions_dialog->Show();
 786 }
 787
 788 void
 789 FilmViewer::seek_by (DCPTime by, bool accurate)
 790 {
 791         seek (_video_position + by, accurate);
 792 }
 793
 794 void
 795 FilmViewer::set_pad_black (bool p)
 796 {
 797         _pad_black = p;
 798 }
 799
 800 void
 801 FilmViewer::content_change (ChangeType type, int property)
 802 {
 803         if (type != CHANGE_TYPE_DONE) {
 804                 return;
 805         }
 806
 807         if (property == TextContentProperty::USE || property == TextContentProperty::TYPE || property == TextContentProperty::DCP_TRACK) {
 808                 _closed_captions_dialog->update_tracks (_film);
 809         }
 810 }