src/wx/film_viewer.cc

   1 /*
   2     Copyright (C) 2012-2018 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 extern "C" {
  48 #include <libavutil/pixfmt.h>
  49 }
  50 #include <dcp/exceptions.h>
  51 #include <wx/tglbtn.h>
  52 #include <iostream>
  53 #include <iomanip>
  54
  55 using std::string;
  56 using std::pair;
  57 using std::min;
  58 using std::max;
  59 using std::cout;
  60 using std::list;
  61 using std::bad_alloc;
  62 using std::make_pair;
  63 using std::exception;
  64 using boost::shared_ptr;
  65 using boost::dynamic_pointer_cast;
  66 using boost::weak_ptr;
  67 using boost::optional;
  68 using dcp::Size;
  69
  70 static
  71 int
  72 rtaudio_callback (void* out, void *, unsigned int frames, double, RtAudioStreamStatus, void* data)
  73 {
  74         return reinterpret_cast<FilmViewer*>(data)->audio_callback (out, frames);
  75 }
  76
  77 FilmViewer::FilmViewer (wxWindow* p)
  78         : _panel (new wxPanel (p))
  79         , _coalesce_player_changes (false)
  80         , _audio (DCPOMATIC_RTAUDIO_API)
  81         , _audio_channels (0)
  82         , _audio_block_size (1024)
  83         , _playing (false)
  84         , _latency_history_count (0)
  85         , _dropped (0)
  86         , _closed_captions_dialog (new ClosedCaptionsDialog(p))
  87         , _outline_content (false)
  88         , _eyes (EYES_LEFT)
  89 #ifdef DCPOMATIC_VARIANT_SWAROOP
  90         , _in_watermark (false)
  91 #endif
  92 {
  93 #ifndef __WXOSX__
  94         _panel->SetDoubleBuffered (true);
  95 #endif
  96
  97         _panel->SetBackgroundStyle (wxBG_STYLE_PAINT);
  98         _panel->SetBackgroundColour (*wxBLACK);
  99
 100         _panel->Bind (wxEVT_PAINT, boost::bind (&FilmViewer::paint_panel, this));
 101         _panel->Bind (wxEVT_SIZE,  boost::bind (&FilmViewer::panel_sized, this, _1));
 102         _timer.Bind  (wxEVT_TIMER, boost::bind (&FilmViewer::timer, this));
 103
 104         set_film (shared_ptr<Film> ());
 105
 106         _config_changed_connection = Config::instance()->Changed.connect (bind (&FilmViewer::config_changed, this, _1));
 107         config_changed (Config::SOUND_OUTPUT);
 108 }
 109
 110 FilmViewer::~FilmViewer ()
 111 {
 112         stop ();
 113 }
 114
 115 void
 116 FilmViewer::set_film (shared_ptr<Film> film)
 117 {
 118         if (_film == film) {
 119                 return;
 120         }
 121
 122         _film = film;
 123
 124         FilmChanged ();
 125
 126         _frame.reset ();
 127         _closed_captions_dialog->clear ();
 128
 129         if (!_film) {
 130                 _player.reset ();
 131                 recreate_butler ();
 132                 _frame.reset ();
 133                 refresh_panel ();
 134                 return;
 135         }
 136
 137         try {
 138                 _player.reset (new Player (_film, _film->playlist ()));
 139                 _player->set_fast ();
 140                 if (_dcp_decode_reduction) {
 141                         _player->set_dcp_decode_reduction (_dcp_decode_reduction);
 142                 }
 143         } catch (bad_alloc) {
 144                 error_dialog (_panel, _("There is not enough free memory to do that."));
 145                 _film.reset ();
 146                 return;
 147         }
 148
 149         _player->set_always_burn_open_subtitles ();
 150         _player->set_play_referenced ();
 151
 152         _film->Change.connect (boost::bind (&FilmViewer::film_change, this, _1, _2));
 153         _player->Change.connect (boost::bind (&FilmViewer::player_change, this, _1, _2, _3));
 154
 155         /* Keep about 1 second's worth of history samples */
 156         _latency_history_count = _film->audio_frame_rate() / _audio_block_size;
 157
 158         recreate_butler ();
 159
 160         calculate_sizes ();
 161         slow_refresh ();
 162 }
 163
 164 void
 165 FilmViewer::recreate_butler ()
 166 {
 167         bool const was_running = stop ();
 168         _butler.reset ();
 169
 170         if (!_film) {
 171                 return;
 172         }
 173
 174         AudioMapping map = AudioMapping (_film->audio_channels(), _audio_channels);
 175
 176         if (_audio_channels != 2 || _film->audio_channels() < 3) {
 177                 for (int i = 0; i < min (_film->audio_channels(), _audio_channels); ++i) {
 178                         map.set (i, i, 1);
 179                 }
 180         } else {
 181                 /* Special case: stereo output, at least 3 channel input.
 182                    Map so that Lt = L(-3dB) + Ls(-3dB) + C(-6dB) + Lfe(-10dB)
 183                                Rt = R(-3dB) + Rs(-3dB) + C(-6dB) + Lfe(-10dB)
 184                 */
 185                 map.set (dcp::LEFT,   0, 1 / sqrt(2)); // L -> Lt
 186                 map.set (dcp::RIGHT,  1, 1 / sqrt(2)); // R -> Rt
 187                 map.set (dcp::CENTRE, 0, 1 / 2.0); // C -> Lt
 188                 map.set (dcp::CENTRE, 1, 1 / 2.0); // C -> Rt
 189                 map.set (dcp::LFE,    0, 1 / sqrt(10)); // Lfe -> Lt
 190                 map.set (dcp::LFE,    1, 1 / sqrt(10)); // Lfe -> Rt
 191                 map.set (dcp::LS,     0, 1 / sqrt(2)); // Ls -> Lt
 192                 map.set (dcp::RS,     1, 1 / sqrt(2)); // Rs -> Rt
 193         }
 194
 195         _butler.reset (new Butler (_player, _film->log(), map, _audio_channels));
 196         if (!Config::instance()->sound() && !_audio.isStreamOpen()) {
 197                 _butler->disable_audio ();
 198         }
 199
 200         _closed_captions_dialog->set_butler (_butler);
 201
 202         if (was_running) {
 203                 start ();
 204         }
 205 }
 206
 207 void
 208 FilmViewer::refresh_panel ()
 209 {
 210         _panel->Refresh ();
 211         _panel->Update ();
 212 }
 213
 214 void
 215 FilmViewer::get ()
 216 {
 217         DCPOMATIC_ASSERT (_butler);
 218
 219         do {
 220                 Butler::Error e;
 221                 _player_video = _butler->get_video (&e);
 222                 if (!_player_video.first && e == Butler::AGAIN) {
 223                         signal_manager->when_idle (boost::bind(&FilmViewer::get, this));
 224                         return;
 225                 }
 226         } while (
 227                 _player_video.first &&
 228                 _film->three_d() &&
 229                 (_eyes != _player_video.first->eyes())
 230                 );
 231
 232         _butler->rethrow ();
 233
 234         display_player_video ();
 235 }
 236
 237 void
 238 FilmViewer::display_player_video ()
 239 {
 240         if (!_player_video.first) {
 241                 _frame.reset ();
 242                 refresh_panel ();
 243                 return;
 244         }
 245
 246         if (_playing && (time() - _player_video.second) > one_video_frame()) {
 247                 /* Too late; just drop this frame before we try to get its image (which will be the time-consuming
 248                    part if this frame is J2K).
 249                 */
 250                 _video_position = _player_video.second;
 251                 ++_dropped;
 252                 return;
 253         }
 254
 255         /* In an ideal world, what we would do here is:
 256          *
 257          * 1. convert to XYZ exactly as we do in the DCP creation path.
 258          * 2. convert back to RGB for the preview display, compensating
 259          *    for the monitor etc. etc.
 260          *
 261          * but this is inefficient if the source is RGB.  Since we don't
 262          * (currently) care too much about the precise accuracy of the preview's
 263          * colour mapping (and we care more about its speed) we try to short-
 264          * circuit this "ideal" situation in some cases.
 265          *
 266          * The content's specified colour conversion indicates the colourspace
 267          * which the content is in (according to the user).
 268          *
 269          * PlayerVideo::image (bound to PlayerVideo::always_rgb) will take the source
 270          * image and convert it (from whatever the user has said it is) to RGB.
 271          */
 272
 273         _frame = _player_video.first->image (
 274                 bind (&Log::dcp_log, _film->log().get(), _1, _2),
 275                 bind (&PlayerVideo::always_rgb, _1),
 276                 false, true
 277                 );
 278
 279         ImageChanged (_player_video.first);
 280
 281         _video_position = _player_video.second;
 282         _inter_position = _player_video.first->inter_position ();
 283         _inter_size = _player_video.first->inter_size ();
 284
 285         refresh_panel ();
 286
 287         _closed_captions_dialog->update (time());
 288 }
 289
 290 void
 291 FilmViewer::timer ()
 292 {
 293         if (!_film || !_playing) {
 294                 return;
 295         }
 296
 297         get ();
 298         PositionChanged ();
 299         DCPTime const next = _video_position + one_video_frame();
 300
 301         if (next >= _film->length()) {
 302                 stop ();
 303         }
 304
 305         _timer.Start (max ((next.seconds() - time().seconds()) * 1000, 1.0), wxTIMER_ONE_SHOT);
 306
 307         if (_butler) {
 308                 _butler->rethrow ();
 309         }
 310 }
 311
 312 void
 313 FilmViewer::paint_panel ()
 314 {
 315         wxPaintDC dc (_panel);
 316
 317         if (!_frame || !_film || !_out_size.width || !_out_size.height || _out_size != _frame->size()) {
 318                 dc.Clear ();
 319 #ifdef DCPOMATIC_VARIANT_SWAROOP
 320                 optional<boost::filesystem::path> bg = Config::instance()->player_background_image();
 321                 if (bg) {
 322                         wxImage image (std_to_wx(bg->string()));
 323                         wxBitmap bitmap (image);
 324                         dc.DrawBitmap (bitmap, max(0, (_panel_size.width - image.GetSize().GetWidth()) / 2), max(0, (_panel_size.height - image.GetSize().GetHeight()) / 2));
 325                 }
 326 #endif
 327                 return;
 328         }
 329
 330         wxImage frame (_out_size.width, _out_size.height, _frame->data()[0], true);
 331         wxBitmap frame_bitmap (frame);
 332         dc.DrawBitmap (frame_bitmap, 0, max(0, (_panel_size.height - _out_size.height) / 2));
 333
 334 #ifdef DCPOMATIC_VARIANT_SWAROOP
 335         DCPTime const period = DCPTime::from_seconds(Config::instance()->player_watermark_period() * 60);
 336         int64_t n = _video_position.get() / period.get();
 337         DCPTime from(n * period.get());
 338         DCPTime to = from + DCPTime::from_seconds(Config::instance()->player_watermark_duration() / 1000.0);
 339         if (from <= _video_position && _video_position <= to) {
 340                 if (!_in_watermark) {
 341                         _in_watermark = true;
 342                         _watermark_x = rand() % _panel_size.width;
 343                         _watermark_y = rand() % _panel_size.height;
 344                 }
 345                 dc.SetTextForeground(*wxWHITE);
 346                 string wm = Config::instance()->player_watermark_theatre();
 347                 boost::posix_time::ptime t = boost::posix_time::second_clock::local_time();
 348                 wm += "\n" + boost::posix_time::to_iso_extended_string(t);
 349                 dc.DrawText(std_to_wx(wm), _watermark_x, _watermark_y);
 350         } else {
 351                 _in_watermark = false;
 352         }
 353 #endif
 354
 355         if (_out_size.width < _panel_size.width) {
 356                 wxPen p (_panel->GetParent()->GetBackgroundColour());
 357                 wxBrush b (_panel->GetParent()->GetBackgroundColour());
 358                 dc.SetPen (p);
 359                 dc.SetBrush (b);
 360                 dc.DrawRectangle (_out_size.width, 0, _panel_size.width - _out_size.width, _panel_size.height);
 361         }
 362
 363         if (_out_size.height < _panel_size.height) {
 364                 wxPen p (_panel->GetParent()->GetBackgroundColour());
 365                 wxBrush b (_panel->GetParent()->GetBackgroundColour());
 366                 dc.SetPen (p);
 367                 dc.SetBrush (b);
 368                 int const gap = (_panel_size.height - _out_size.height) / 2;
 369                 dc.DrawRectangle (0, 0, _panel_size.width, gap);
 370                 dc.DrawRectangle (0, gap + _out_size.height, _panel_size.width, gap);
 371         }
 372
 373         if (_outline_content) {
 374                 wxPen p (wxColour (255, 0, 0), 2);
 375                 dc.SetPen (p);
 376                 dc.SetBrush (*wxTRANSPARENT_BRUSH);
 377                 dc.DrawRectangle (_inter_position.x, _inter_position.y, _inter_size.width, _inter_size.height);
 378         }
 379 }
 380
 381 void
 382 FilmViewer::set_outline_content (bool o)
 383 {
 384         _outline_content = o;
 385         refresh_panel ();
 386 }
 387
 388 void
 389 FilmViewer::set_eyes (Eyes e)
 390 {
 391         _eyes = e;
 392         slow_refresh ();
 393 }
 394
 395 void
 396 FilmViewer::panel_sized (wxSizeEvent& ev)
 397 {
 398         _panel_size.width = ev.GetSize().GetWidth();
 399         _panel_size.height = ev.GetSize().GetHeight();
 400
 401         calculate_sizes ();
 402         if (!quick_refresh()) {
 403                 slow_refresh ();
 404         }
 405         PositionChanged ();
 406 }
 407
 408 void
 409 FilmViewer::calculate_sizes ()
 410 {
 411         if (!_film || !_player) {
 412                 return;
 413         }
 414
 415         Ratio const * container = _film->container ();
 416
 417         float const panel_ratio = _panel_size.ratio ();
 418         float const film_ratio = container ? container->ratio () : 1.78;
 419
 420         if (panel_ratio < film_ratio) {
 421                 /* panel is less widscreen than the film; clamp width */
 422                 _out_size.width = _panel_size.width;
 423                 _out_size.height = lrintf (_out_size.width / film_ratio);
 424         } else {
 425                 /* panel is more widescreen than the film; clamp height */
 426                 _out_size.height = _panel_size.height;
 427                 _out_size.width = lrintf (_out_size.height * film_ratio);
 428         }
 429
 430         /* Catch silly values */
 431         _out_size.width = max (64, _out_size.width);
 432         _out_size.height = max (64, _out_size.height);
 433
 434         _player->set_video_container_size (_out_size);
 435 }
 436
 437 void
 438 FilmViewer::start ()
 439 {
 440         if (!_film) {
 441                 return;
 442         }
 443
 444         optional<bool> v = PlaybackPermitted ();
 445         if (v && !*v) {
 446                 /* Computer says no */
 447                 return;
 448         }
 449
 450         if (_audio.isStreamOpen()) {
 451                 _audio.setStreamTime (_video_position.seconds());
 452                 _audio.startStream ();
 453         }
 454
 455         _playing = true;
 456         _dropped = 0;
 457         timer ();
 458         Started (position());
 459 }
 460
 461 bool
 462 FilmViewer::stop ()
 463 {
 464         if (_audio.isStreamRunning()) {
 465                 /* stop stream and discard any remaining queued samples */
 466                 _audio.abortStream ();
 467         }
 468
 469         if (!_playing) {
 470                 return false;
 471         }
 472
 473         _playing = false;
 474         Stopped (position());
 475         return true;
 476 }
 477
 478 void
 479 FilmViewer::player_change (ChangeType type, int property, bool frequent)
 480 {
 481         if (type != CHANGE_TYPE_DONE || frequent) {
 482                 return;
 483         }
 484
 485         if (_coalesce_player_changes) {
 486                 _pending_player_changes.push_back (property);
 487                 return;
 488         }
 489
 490         calculate_sizes ();
 491         bool refreshed = false;
 492         if (
 493                 property == VideoContentProperty::CROP ||
 494                 property == VideoContentProperty::SCALE ||
 495                 property == VideoContentProperty::FADE_IN ||
 496                 property == VideoContentProperty::FADE_OUT ||
 497                 property == VideoContentProperty::COLOUR_CONVERSION ||
 498                 property == PlayerProperty::VIDEO_CONTAINER_SIZE ||
 499                 property == PlayerProperty::FILM_CONTAINER
 500                 ) {
 501                 refreshed = quick_refresh ();
 502         }
 503
 504         if (!refreshed) {
 505                 slow_refresh ();
 506         }
 507         PositionChanged ();
 508 }
 509
 510 void
 511 FilmViewer::film_change (ChangeType type, Film::Property p)
 512 {
 513         if (type == CHANGE_TYPE_DONE && p == Film::AUDIO_CHANNELS) {
 514                 recreate_butler ();
 515         }
 516 }
 517
 518 /** Re-get the current frame slowly by seeking */
 519 void
 520 FilmViewer::slow_refresh ()
 521 {
 522         seek (_video_position, true);
 523 }
 524
 525 /** Try to re-get the current frame quickly by resetting the metadata
 526  *  in the PlayerVideo that we used last time.
 527  *  @return true if this was possible, false if not.
 528  */
 529 bool
 530 FilmViewer::quick_refresh ()
 531 {
 532         if (!_player_video.first) {
 533                 return false;
 534         }
 535
 536         if (!_player_video.first->reset_metadata (_player->video_container_size(), _film->frame_size())) {
 537                 return false;
 538         }
 539
 540         display_player_video ();
 541         return true;
 542 }
 543
 544 void
 545 FilmViewer::seek (shared_ptr<Content> content, ContentTime t, bool accurate)
 546 {
 547         optional<DCPTime> dt = _player->content_time_to_dcp (content, t);
 548         if (dt) {
 549                 seek (*dt, accurate);
 550         }
 551 }
 552
 553 void
 554 FilmViewer::set_coalesce_player_changes (bool c)
 555 {
 556         _coalesce_player_changes = c;
 557
 558         if (!c) {
 559                 BOOST_FOREACH (int i, _pending_player_changes) {
 560                         player_change (CHANGE_TYPE_DONE, i, false);
 561                 }
 562                 _pending_player_changes.clear ();
 563         }
 564 }
 565
 566 void
 567 FilmViewer::seek (DCPTime t, bool accurate)
 568 {
 569         if (!_butler) {
 570                 return;
 571         }
 572
 573         if (t < DCPTime ()) {
 574                 t = DCPTime ();
 575         }
 576
 577         if (t >= _film->length ()) {
 578                 t = _film->length ();
 579         }
 580
 581         bool const was_running = stop ();
 582
 583         _closed_captions_dialog->clear ();
 584         _butler->seek (t, accurate);
 585         get ();
 586
 587         if (was_running) {
 588                 start ();
 589         }
 590
 591         PositionChanged ();
 592         Seeked (position());
 593 }
 594
 595 void
 596 FilmViewer::config_changed (Config::Property p)
 597 {
 598 #ifdef DCPOMATIC_VARIANT_SWAROOP
 599         if (p == Config::PLAYER_BACKGROUND_IMAGE) {
 600                 refresh_panel ();
 601                 return;
 602         }
 603 #endif
 604
 605         if (p != Config::SOUND && p != Config::SOUND_OUTPUT) {
 606                 return;
 607         }
 608
 609         if (_audio.isStreamOpen ()) {
 610                 _audio.closeStream ();
 611         }
 612
 613         if (Config::instance()->sound() && _audio.getDeviceCount() > 0) {
 614                 unsigned int st = 0;
 615                 if (Config::instance()->sound_output()) {
 616                         while (st < _audio.getDeviceCount()) {
 617                                 if (_audio.getDeviceInfo(st).name == Config::instance()->sound_output().get()) {
 618                                         break;
 619                                 }
 620                                 ++st;
 621                         }
 622                         if (st == _audio.getDeviceCount()) {
 623                                 st = _audio.getDefaultOutputDevice();
 624                         }
 625                 } else {
 626                         st = _audio.getDefaultOutputDevice();
 627                 }
 628
 629                 _audio_channels = _audio.getDeviceInfo(st).outputChannels;
 630
 631                 RtAudio::StreamParameters sp;
 632                 sp.deviceId = st;
 633                 sp.nChannels = _audio_channels;
 634                 sp.firstChannel = 0;
 635                 try {
 636                         _audio.openStream (&sp, 0, RTAUDIO_FLOAT32, 48000, &_audio_block_size, &rtaudio_callback, this);
 637 #ifdef DCPOMATIC_USE_RTERROR
 638                 } catch (RtError& e) {
 639 #else
 640                 } catch (RtAudioError& e) {
 641 #endif
 642                         error_dialog (
 643                                 _panel,
 644                                 _("Could not set up audio output.  There will be no audio during the preview."), std_to_wx(e.what())
 645                                 );
 646                 }
 647                 recreate_butler ();
 648
 649         } else {
 650                 _audio_channels = 0;
 651                 recreate_butler ();
 652         }
 653 }
 654
 655 DCPTime
 656 FilmViewer::uncorrected_time () const
 657 {
 658         if (_audio.isStreamRunning ()) {
 659                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime());
 660         }
 661
 662         return _video_position;
 663 }
 664
 665 DCPTime
 666 FilmViewer::time () const
 667 {
 668         if (_audio.isStreamRunning ()) {
 669                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime ()) -
 670                         DCPTime::from_frames (average_latency(), _film->audio_frame_rate());
 671         }
 672
 673         return _video_position;
 674 }
 675
 676 int
 677 FilmViewer::audio_callback (void* out_p, unsigned int frames)
 678 {
 679         while (true) {
 680                 optional<DCPTime> t = _butler->get_audio (reinterpret_cast<float*> (out_p), frames);
 681                 if (!t || DCPTime(uncorrected_time() - *t) < one_video_frame()) {
 682                         /* There was an underrun or this audio is on time; carry on */
 683                         break;
 684                 }
 685                 /* The audio we just got was (very) late; drop it and get some more. */
 686         }
 687
 688         boost::mutex::scoped_lock lm (_latency_history_mutex, boost::try_to_lock);
 689         if (lm) {
 690                 _latency_history.push_back (_audio.getStreamLatency ());
 691                 if (_latency_history.size() > static_cast<size_t> (_latency_history_count)) {
 692                         _latency_history.pop_front ();
 693                 }
 694         }
 695
 696         return 0;
 697 }
 698
 699 Frame
 700 FilmViewer::average_latency () const
 701 {
 702         boost::mutex::scoped_lock lm (_latency_history_mutex);
 703         if (_latency_history.empty()) {
 704                 return 0;
 705         }
 706
 707         Frame total = 0;
 708         BOOST_FOREACH (Frame i, _latency_history) {
 709                 total += i;
 710         }
 711
 712         return total / _latency_history.size();
 713 }
 714
 715 void
 716 FilmViewer::set_dcp_decode_reduction (optional<int> reduction)
 717 {
 718         _dcp_decode_reduction = reduction;
 719         if (_player) {
 720                 _player->set_dcp_decode_reduction (reduction);
 721         }
 722 }
 723
 724 optional<int>
 725 FilmViewer::dcp_decode_reduction () const
 726 {
 727         return _dcp_decode_reduction;
 728 }
 729
 730 DCPTime
 731 FilmViewer::one_video_frame () const
 732 {
 733         return DCPTime::from_frames (1, _film->video_frame_rate());
 734 }
 735
 736 /** Open a dialog box showing our film's closed captions */
 737 void
 738 FilmViewer::show_closed_captions ()
 739 {
 740         _closed_captions_dialog->Show();
 741 }
 742
 743 void
 744 FilmViewer::seek_by (DCPTime by, bool accurate)
 745 {
 746         seek (_video_position + by, accurate);
 747 }