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         _frame.reset ();
 126         _closed_captions_dialog->clear ();
 127
 128         if (!_film) {
 129                 _player.reset ();
 130                 recreate_butler ();
 131                 _frame.reset ();
 132                 refresh_panel ();
 133                 return;
 134         }
 135
 136         try {
 137                 _player.reset (new Player (_film, _film->playlist ()));
 138                 _player->set_fast ();
 139                 if (_dcp_decode_reduction) {
 140                         _player->set_dcp_decode_reduction (_dcp_decode_reduction);
 141                 }
 142         } catch (bad_alloc) {
 143                 error_dialog (_panel, _("There is not enough free memory to do that."));
 144                 _film.reset ();
 145                 return;
 146         }
 147
 148         _player->set_always_burn_open_subtitles ();
 149         _player->set_play_referenced ();
 150
 151         _film->Change.connect (boost::bind (&FilmViewer::film_change, this, _1, _2));
 152         _player->Change.connect (boost::bind (&FilmViewer::player_change, this, _1, _2, _3));
 153
 154         /* Keep about 1 second's worth of history samples */
 155         _latency_history_count = _film->audio_frame_rate() / _audio_block_size;
 156
 157         recreate_butler ();
 158
 159         calculate_sizes ();
 160         slow_refresh ();
 161 }
 162
 163 void
 164 FilmViewer::recreate_butler ()
 165 {
 166         bool const was_running = stop ();
 167         _butler.reset ();
 168
 169         if (!_film) {
 170                 return;
 171         }
 172
 173         AudioMapping map = AudioMapping (_film->audio_channels(), _audio_channels);
 174
 175         if (_audio_channels != 2 || _film->audio_channels() < 3) {
 176                 for (int i = 0; i < min (_film->audio_channels(), _audio_channels); ++i) {
 177                         map.set (i, i, 1);
 178                 }
 179         } else {
 180                 /* Special case: stereo output, at least 3 channel input.
 181                    Map so that Lt = L(-3dB) + Ls(-3dB) + C(-6dB) + Lfe(-10dB)
 182                                Rt = R(-3dB) + Rs(-3dB) + C(-6dB) + Lfe(-10dB)
 183                 */
 184                 map.set (dcp::LEFT,   0, 1 / sqrt(2)); // L -> Lt
 185                 map.set (dcp::RIGHT,  1, 1 / sqrt(2)); // R -> Rt
 186                 map.set (dcp::CENTRE, 0, 1 / 2.0); // C -> Lt
 187                 map.set (dcp::CENTRE, 1, 1 / 2.0); // C -> Rt
 188                 map.set (dcp::LFE,    0, 1 / sqrt(10)); // Lfe -> Lt
 189                 map.set (dcp::LFE,    1, 1 / sqrt(10)); // Lfe -> Rt
 190                 map.set (dcp::LS,     0, 1 / sqrt(2)); // Ls -> Lt
 191                 map.set (dcp::RS,     1, 1 / sqrt(2)); // Rs -> Rt
 192         }
 193
 194         _butler.reset (new Butler(_player, map, _audio_channels, bind(&PlayerVideo::force, _1, AV_PIX_FMT_RGB24), false, true));
 195         if (!Config::instance()->sound() && !_audio.isStreamOpen()) {
 196                 _butler->disable_audio ();
 197         }
 198
 199         _closed_captions_dialog->set_butler (_butler);
 200
 201         if (was_running) {
 202                 start ();
 203         }
 204 }
 205
 206 void
 207 FilmViewer::refresh_panel ()
 208 {
 209         _panel->Refresh ();
 210         _panel->Update ();
 211 }
 212
 213 void
 214 FilmViewer::get ()
 215 {
 216         DCPOMATIC_ASSERT (_butler);
 217
 218         do {
 219                 Butler::Error e;
 220                 _player_video = _butler->get_video (&e);
 221                 if (!_player_video.first && e == Butler::AGAIN) {
 222                         signal_manager->when_idle (boost::bind(&FilmViewer::get, this));
 223                         return;
 224                 }
 225         } while (
 226                 _player_video.first &&
 227                 _film->three_d() &&
 228                 (_eyes != _player_video.first->eyes())
 229                 );
 230
 231         _butler->rethrow ();
 232
 233         display_player_video ();
 234 }
 235
 236 void
 237 FilmViewer::display_player_video ()
 238 {
 239         if (!_player_video.first) {
 240                 _frame.reset ();
 241                 refresh_panel ();
 242                 return;
 243         }
 244
 245         if (_playing && (time() - _player_video.second) > one_video_frame()) {
 246                 /* Too late; just drop this frame before we try to get its image (which will be the time-consuming
 247                    part if this frame is J2K).
 248                 */
 249                 _video_position = _player_video.second;
 250                 ++_dropped;
 251                 return;
 252         }
 253
 254         /* In an ideal world, what we would do here is:
 255          *
 256          * 1. convert to XYZ exactly as we do in the DCP creation path.
 257          * 2. convert back to RGB for the preview display, compensating
 258          *    for the monitor etc. etc.
 259          *
 260          * but this is inefficient if the source is RGB.  Since we don't
 261          * (currently) care too much about the precise accuracy of the preview's
 262          * colour mapping (and we care more about its speed) we try to short-
 263          * circuit this "ideal" situation in some cases.
 264          *
 265          * The content's specified colour conversion indicates the colourspace
 266          * which the content is in (according to the user).
 267          *
 268          * PlayerVideo::image (bound to PlayerVideo::force) will take the source
 269          * image and convert it (from whatever the user has said it is) to RGB.
 270          */
 271
 272         _frame = _player_video.first->image (bind(&PlayerVideo::force, _1, AV_PIX_FMT_RGB24), false, true);
 273
 274         ImageChanged (_player_video.first);
 275
 276         _video_position = _player_video.second;
 277         _inter_position = _player_video.first->inter_position ();
 278         _inter_size = _player_video.first->inter_size ();
 279
 280         refresh_panel ();
 281
 282         _closed_captions_dialog->update (time());
 283 }
 284
 285 void
 286 FilmViewer::timer ()
 287 {
 288         if (!_film || !_playing) {
 289                 return;
 290         }
 291
 292         get ();
 293         PositionChanged ();
 294         DCPTime const next = _video_position + one_video_frame();
 295
 296         if (next >= _film->length()) {
 297                 stop ();
 298         }
 299
 300         _timer.Start (max ((next.seconds() - time().seconds()) * 1000, 1.0), wxTIMER_ONE_SHOT);
 301
 302         if (_butler) {
 303                 _butler->rethrow ();
 304         }
 305 }
 306
 307 bool
 308 FilmViewer::maybe_draw_background_image (wxPaintDC& dc)
 309 {
 310 #ifdef DCPOMATIC_VARIANT_SWAROOP
 311         optional<boost::filesystem::path> bg = Config::instance()->player_background_image();
 312         if (bg) {
 313                 wxImage image (std_to_wx(bg->string()));
 314                 wxBitmap bitmap (image);
 315                 dc.DrawBitmap (bitmap, max(0, (_panel_size.width - image.GetSize().GetWidth()) / 2), max(0, (_panel_size.height - image.GetSize().GetHeight()) / 2));
 316                 return true;
 317         }
 318 #endif
 319
 320         return false;
 321 }
 322
 323 void
 324 FilmViewer::paint_panel ()
 325 {
 326         wxPaintDC dc (_panel);
 327
 328         if (!_frame || !_film || !_out_size.width || !_out_size.height || _out_size != _frame->size()) {
 329                 dc.Clear ();
 330                 maybe_draw_background_image (dc);
 331                 return;
 332         }
 333
 334         if (_video_position == DCPTime() && maybe_draw_background_image (dc)) {
 335                 return;
 336         }
 337
 338         wxImage frame (_out_size.width, _out_size.height, _frame->data()[0], true);
 339         wxBitmap frame_bitmap (frame);
 340         dc.DrawBitmap (frame_bitmap, 0, max(0, (_panel_size.height - _out_size.height) / 2));
 341
 342 #ifdef DCPOMATIC_VARIANT_SWAROOP
 343         DCPTime const period = DCPTime::from_seconds(Config::instance()->player_watermark_period() * 60);
 344         int64_t n = _video_position.get() / period.get();
 345         DCPTime from(n * period.get());
 346         DCPTime to = from + DCPTime::from_seconds(Config::instance()->player_watermark_duration() / 1000.0);
 347         if (from <= _video_position && _video_position <= to) {
 348                 if (!_in_watermark) {
 349                         _in_watermark = true;
 350                         _watermark_x = rand() % _panel_size.width;
 351                         _watermark_y = rand() % _panel_size.height;
 352                 }
 353                 dc.SetTextForeground(*wxWHITE);
 354                 string wm = Config::instance()->player_watermark_theatre();
 355                 boost::posix_time::ptime t = boost::posix_time::second_clock::local_time();
 356                 wm += "\n" + boost::posix_time::to_iso_extended_string(t);
 357                 dc.DrawText(std_to_wx(wm), _watermark_x, _watermark_y);
 358         } else {
 359                 _in_watermark = false;
 360         }
 361 #endif
 362
 363         if (_out_size.width < _panel_size.width) {
 364                 /* XXX: these colours are right for GNOME; may need adjusting for other OS */
 365                 wxPen   p (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 366                 wxBrush b (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 367                 dc.SetPen (p);
 368                 dc.SetBrush (b);
 369                 dc.DrawRectangle (_out_size.width, 0, _panel_size.width - _out_size.width, _panel_size.height);
 370         }
 371
 372         if (_out_size.height < _panel_size.height) {
 373                 wxPen   p (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 374                 wxBrush b (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 375                 dc.SetPen (p);
 376                 dc.SetBrush (b);
 377                 int const gap = (_panel_size.height - _out_size.height) / 2;
 378                 dc.DrawRectangle (0, 0, _panel_size.width, gap);
 379                 dc.DrawRectangle (0, gap + _out_size.height + 1, _panel_size.width, gap);
 380         }
 381
 382         if (_outline_content) {
 383                 wxPen p (wxColour (255, 0, 0), 2);
 384                 dc.SetPen (p);
 385                 dc.SetBrush (*wxTRANSPARENT_BRUSH);
 386                 dc.DrawRectangle (_inter_position.x, _inter_position.y + (_panel_size.height - _out_size.height) / 2, _inter_size.width, _inter_size.height);
 387         }
 388 }
 389
 390 void
 391 FilmViewer::set_outline_content (bool o)
 392 {
 393         _outline_content = o;
 394         refresh_panel ();
 395 }
 396
 397 void
 398 FilmViewer::set_eyes (Eyes e)
 399 {
 400         _eyes = e;
 401         slow_refresh ();
 402 }
 403
 404 void
 405 FilmViewer::panel_sized (wxSizeEvent& ev)
 406 {
 407         _panel_size.width = ev.GetSize().GetWidth();
 408         _panel_size.height = ev.GetSize().GetHeight();
 409
 410         calculate_sizes ();
 411         if (!quick_refresh()) {
 412                 slow_refresh ();
 413         }
 414         PositionChanged ();
 415 }
 416
 417 void
 418 FilmViewer::calculate_sizes ()
 419 {
 420         if (!_film || !_player) {
 421                 return;
 422         }
 423
 424         Ratio const * container = _film->container ();
 425
 426         float const panel_ratio = _panel_size.ratio ();
 427         float const film_ratio = container ? container->ratio () : 1.78;
 428
 429         if (panel_ratio < film_ratio) {
 430                 /* panel is less widscreen than the film; clamp width */
 431                 _out_size.width = _panel_size.width;
 432                 _out_size.height = lrintf (_out_size.width / film_ratio);
 433         } else {
 434                 /* panel is more widescreen than the film; clamp height */
 435                 _out_size.height = _panel_size.height;
 436                 _out_size.width = lrintf (_out_size.height * film_ratio);
 437         }
 438
 439         /* Catch silly values */
 440         _out_size.width = max (64, _out_size.width);
 441         _out_size.height = max (64, _out_size.height);
 442
 443         _player->set_video_container_size (_out_size);
 444 }
 445
 446 void
 447 FilmViewer::start ()
 448 {
 449         if (!_film) {
 450                 return;
 451         }
 452
 453         optional<bool> v = PlaybackPermitted ();
 454         if (v && !*v) {
 455                 /* Computer says no */
 456                 return;
 457         }
 458
 459         if (_audio.isStreamOpen()) {
 460                 _audio.setStreamTime (_video_position.seconds());
 461                 _audio.startStream ();
 462         }
 463
 464         _playing = true;
 465         _dropped = 0;
 466         timer ();
 467         Started (position());
 468 }
 469
 470 bool
 471 FilmViewer::stop ()
 472 {
 473         if (_audio.isStreamRunning()) {
 474                 /* stop stream and discard any remaining queued samples */
 475                 _audio.abortStream ();
 476         }
 477
 478         if (!_playing) {
 479                 return false;
 480         }
 481
 482         _playing = false;
 483         Stopped (position());
 484         return true;
 485 }
 486
 487 void
 488 FilmViewer::player_change (ChangeType type, int property, bool frequent)
 489 {
 490         if (type != CHANGE_TYPE_DONE || frequent) {
 491                 return;
 492         }
 493
 494         if (_coalesce_player_changes) {
 495                 _pending_player_changes.push_back (property);
 496                 return;
 497         }
 498
 499         calculate_sizes ();
 500         bool refreshed = false;
 501         if (
 502                 property == VideoContentProperty::CROP ||
 503                 property == VideoContentProperty::SCALE ||
 504                 property == VideoContentProperty::FADE_IN ||
 505                 property == VideoContentProperty::FADE_OUT ||
 506                 property == VideoContentProperty::COLOUR_CONVERSION ||
 507                 property == PlayerProperty::VIDEO_CONTAINER_SIZE ||
 508                 property == PlayerProperty::FILM_CONTAINER
 509                 ) {
 510                 refreshed = quick_refresh ();
 511         }
 512
 513         if (!refreshed) {
 514                 slow_refresh ();
 515         }
 516         PositionChanged ();
 517 }
 518
 519 void
 520 FilmViewer::film_change (ChangeType type, Film::Property p)
 521 {
 522         if (type == CHANGE_TYPE_DONE && p == Film::AUDIO_CHANNELS) {
 523                 recreate_butler ();
 524         }
 525 }
 526
 527 /** Re-get the current frame slowly by seeking */
 528 void
 529 FilmViewer::slow_refresh ()
 530 {
 531         seek (_video_position, true);
 532 }
 533
 534 /** Try to re-get the current frame quickly by resetting the metadata
 535  *  in the PlayerVideo that we used last time.
 536  *  @return true if this was possible, false if not.
 537  */
 538 bool
 539 FilmViewer::quick_refresh ()
 540 {
 541         if (!_player_video.first) {
 542                 return false;
 543         }
 544
 545         if (!_player_video.first->reset_metadata (_film, _player->video_container_size(), _film->frame_size())) {
 546                 return false;
 547         }
 548
 549         display_player_video ();
 550         return true;
 551 }
 552
 553 void
 554 FilmViewer::seek (shared_ptr<Content> content, ContentTime t, bool accurate)
 555 {
 556         optional<DCPTime> dt = _player->content_time_to_dcp (content, t);
 557         if (dt) {
 558                 seek (*dt, accurate);
 559         }
 560 }
 561
 562 void
 563 FilmViewer::set_coalesce_player_changes (bool c)
 564 {
 565         _coalesce_player_changes = c;
 566
 567         if (!c) {
 568                 BOOST_FOREACH (int i, _pending_player_changes) {
 569                         player_change (CHANGE_TYPE_DONE, i, false);
 570                 }
 571                 _pending_player_changes.clear ();
 572         }
 573 }
 574
 575 void
 576 FilmViewer::seek (DCPTime t, bool accurate)
 577 {
 578         if (!_butler) {
 579                 return;
 580         }
 581
 582         if (t < DCPTime ()) {
 583                 t = DCPTime ();
 584         }
 585
 586         if (t >= _film->length ()) {
 587                 t = _film->length ();
 588         }
 589
 590         bool const was_running = stop ();
 591
 592         _closed_captions_dialog->clear ();
 593         _butler->seek (t, accurate);
 594         get ();
 595
 596         if (was_running) {
 597                 start ();
 598         }
 599
 600         PositionChanged ();
 601         Seeked (position());
 602 }
 603
 604 void
 605 FilmViewer::config_changed (Config::Property p)
 606 {
 607 #ifdef DCPOMATIC_VARIANT_SWAROOP
 608         if (p == Config::PLAYER_BACKGROUND_IMAGE) {
 609                 refresh_panel ();
 610                 return;
 611         }
 612 #endif
 613
 614         if (p != Config::SOUND && p != Config::SOUND_OUTPUT) {
 615                 return;
 616         }
 617
 618         if (_audio.isStreamOpen ()) {
 619                 _audio.closeStream ();
 620         }
 621
 622         if (Config::instance()->sound() && _audio.getDeviceCount() > 0) {
 623                 unsigned int st = 0;
 624                 if (Config::instance()->sound_output()) {
 625                         while (st < _audio.getDeviceCount()) {
 626                                 if (_audio.getDeviceInfo(st).name == Config::instance()->sound_output().get()) {
 627                                         break;
 628                                 }
 629                                 ++st;
 630                         }
 631                         if (st == _audio.getDeviceCount()) {
 632                                 st = _audio.getDefaultOutputDevice();
 633                         }
 634                 } else {
 635                         st = _audio.getDefaultOutputDevice();
 636                 }
 637
 638                 _audio_channels = _audio.getDeviceInfo(st).outputChannels;
 639                 cout << "RtAudio reports " << _audio_channels << " channels.\n";
 640
 641                 RtAudio::StreamParameters sp;
 642                 sp.deviceId = st;
 643                 sp.nChannels = _audio_channels;
 644                 sp.firstChannel = 0;
 645                 try {
 646                         _audio.openStream (&sp, 0, RTAUDIO_FLOAT32, 48000, &_audio_block_size, &rtaudio_callback, this);
 647 #ifdef DCPOMATIC_USE_RTERROR
 648                 } catch (RtError& e) {
 649 #else
 650                 } catch (RtAudioError& e) {
 651 #endif
 652                         error_dialog (
 653                                 _panel,
 654                                 _("Could not set up audio output.  There will be no audio during the preview."), std_to_wx(e.what())
 655                                 );
 656                 }
 657                 recreate_butler ();
 658
 659         } else {
 660                 _audio_channels = 0;
 661                 recreate_butler ();
 662         }
 663 }
 664
 665 DCPTime
 666 FilmViewer::uncorrected_time () const
 667 {
 668         if (_audio.isStreamRunning ()) {
 669                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime());
 670         }
 671
 672         return _video_position;
 673 }
 674
 675 DCPTime
 676 FilmViewer::time () const
 677 {
 678         if (_audio.isStreamRunning ()) {
 679                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime ()) -
 680                         DCPTime::from_frames (average_latency(), _film->audio_frame_rate());
 681         }
 682
 683         return _video_position;
 684 }
 685
 686 int
 687 FilmViewer::audio_callback (void* out_p, unsigned int frames)
 688 {
 689         while (true) {
 690                 optional<DCPTime> t = _butler->get_audio (reinterpret_cast<float*> (out_p), frames);
 691                 if (!t || DCPTime(uncorrected_time() - *t) < one_video_frame()) {
 692                         /* There was an underrun or this audio is on time; carry on */
 693                         break;
 694                 }
 695                 /* The audio we just got was (very) late; drop it and get some more. */
 696         }
 697
 698         boost::mutex::scoped_lock lm (_latency_history_mutex, boost::try_to_lock);
 699         if (lm) {
 700                 _latency_history.push_back (_audio.getStreamLatency ());
 701                 if (_latency_history.size() > static_cast<size_t> (_latency_history_count)) {
 702                         _latency_history.pop_front ();
 703                 }
 704         }
 705
 706         return 0;
 707 }
 708
 709 Frame
 710 FilmViewer::average_latency () const
 711 {
 712         boost::mutex::scoped_lock lm (_latency_history_mutex);
 713         if (_latency_history.empty()) {
 714                 return 0;
 715         }
 716
 717         Frame total = 0;
 718         BOOST_FOREACH (Frame i, _latency_history) {
 719                 total += i;
 720         }
 721
 722         return total / _latency_history.size();
 723 }
 724
 725 void
 726 FilmViewer::set_dcp_decode_reduction (optional<int> reduction)
 727 {
 728         _dcp_decode_reduction = reduction;
 729         if (_player) {
 730                 _player->set_dcp_decode_reduction (reduction);
 731         }
 732 }
 733
 734 optional<int>
 735 FilmViewer::dcp_decode_reduction () const
 736 {
 737         return _dcp_decode_reduction;
 738 }
 739
 740 DCPTime
 741 FilmViewer::one_video_frame () const
 742 {
 743         return DCPTime::from_frames (1, _film->video_frame_rate());
 744 }
 745
 746 /** Open a dialog box showing our film's closed captions */
 747 void
 748 FilmViewer::show_closed_captions ()
 749 {
 750         _closed_captions_dialog->Show();
 751 }
 752
 753 void
 754 FilmViewer::seek_by (DCPTime by, bool accurate)
 755 {
 756         seek (_video_position + by, accurate);
 757 }
 758
 759 void
 760 FilmViewer::set_pad_black (bool p)
 761 {
 762         _pad_black = p;
 763 }