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