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         _video_position = DCPTime ();
 125         _player_video.first.reset ();
 126         _player_video.second = DCPTime ();
 127
 128         _frame.reset ();
 129         _closed_captions_dialog->clear ();
 130
 131         if (!_film) {
 132                 _player.reset ();
 133                 recreate_butler ();
 134                 _frame.reset ();
 135                 refresh_panel ();
 136                 return;
 137         }
 138
 139         try {
 140                 _player.reset (new Player (_film, _film->playlist ()));
 141                 _player->set_fast ();
 142                 if (_dcp_decode_reduction) {
 143                         _player->set_dcp_decode_reduction (_dcp_decode_reduction);
 144                 }
 145         } catch (bad_alloc) {
 146                 error_dialog (_panel, _("There is not enough free memory to do that."));
 147                 _film.reset ();
 148                 return;
 149         }
 150
 151         _player->set_always_burn_open_subtitles ();
 152         _player->set_play_referenced ();
 153
 154         _film->Change.connect (boost::bind (&FilmViewer::film_change, this, _1, _2));
 155         _player->Change.connect (boost::bind (&FilmViewer::player_change, this, _1, _2, _3));
 156
 157         /* Keep about 1 second's worth of history samples */
 158         _latency_history_count = _film->audio_frame_rate() / _audio_block_size;
 159
 160         recreate_butler ();
 161
 162         calculate_sizes ();
 163         slow_refresh ();
 164 }
 165
 166 void
 167 FilmViewer::recreate_butler ()
 168 {
 169         bool const was_running = stop ();
 170         _butler.reset ();
 171
 172         if (!_film) {
 173                 return;
 174         }
 175
 176         AudioMapping map = AudioMapping (_film->audio_channels(), _audio_channels);
 177
 178         if (_audio_channels != 2 || _film->audio_channels() < 3) {
 179                 for (int i = 0; i < min (_film->audio_channels(), _audio_channels); ++i) {
 180                         map.set (i, i, 1);
 181                 }
 182         } else {
 183                 /* Special case: stereo output, at least 3 channel input.
 184                    Map so that Lt = L(-3dB) + Ls(-3dB) + C(-6dB) + Lfe(-10dB)
 185                                Rt = R(-3dB) + Rs(-3dB) + C(-6dB) + Lfe(-10dB)
 186                 */
 187                 map.set (dcp::LEFT,   0, 1 / sqrt(2)); // L -> Lt
 188                 map.set (dcp::RIGHT,  1, 1 / sqrt(2)); // R -> Rt
 189                 map.set (dcp::CENTRE, 0, 1 / 2.0); // C -> Lt
 190                 map.set (dcp::CENTRE, 1, 1 / 2.0); // C -> Rt
 191                 map.set (dcp::LFE,    0, 1 / sqrt(10)); // Lfe -> Lt
 192                 map.set (dcp::LFE,    1, 1 / sqrt(10)); // Lfe -> Rt
 193                 map.set (dcp::LS,     0, 1 / sqrt(2)); // Ls -> Lt
 194                 map.set (dcp::RS,     1, 1 / sqrt(2)); // Rs -> Rt
 195         }
 196
 197         _butler.reset (new Butler(_player, map, _audio_channels, bind(&PlayerVideo::force, _1, AV_PIX_FMT_RGB24), false, true));
 198         if (!Config::instance()->sound() && !_audio.isStreamOpen()) {
 199                 _butler->disable_audio ();
 200         }
 201
 202         _closed_captions_dialog->set_butler (_butler);
 203
 204         if (was_running) {
 205                 start ();
 206         }
 207 }
 208
 209 void
 210 FilmViewer::refresh_panel ()
 211 {
 212         _panel->Refresh ();
 213         _panel->Update ();
 214 }
 215
 216 void
 217 FilmViewer::get ()
 218 {
 219         DCPOMATIC_ASSERT (_butler);
 220
 221         do {
 222                 Butler::Error e;
 223                 _player_video = _butler->get_video (&e);
 224                 if (!_player_video.first && e == Butler::AGAIN) {
 225                         signal_manager->when_idle (boost::bind(&FilmViewer::get, this));
 226                         return;
 227                 }
 228         } while (
 229                 _player_video.first &&
 230                 _film->three_d() &&
 231                 (_eyes != _player_video.first->eyes())
 232                 );
 233
 234         _butler->rethrow ();
 235
 236         display_player_video ();
 237 }
 238
 239 void
 240 FilmViewer::display_player_video ()
 241 {
 242         if (!_player_video.first) {
 243                 _frame.reset ();
 244                 refresh_panel ();
 245                 return;
 246         }
 247
 248         if (_playing && (time() - _player_video.second) > one_video_frame()) {
 249                 /* Too late; just drop this frame before we try to get its image (which will be the time-consuming
 250                    part if this frame is J2K).
 251                 */
 252                 _video_position = _player_video.second;
 253                 ++_dropped;
 254                 return;
 255         }
 256
 257         /* In an ideal world, what we would do here is:
 258          *
 259          * 1. convert to XYZ exactly as we do in the DCP creation path.
 260          * 2. convert back to RGB for the preview display, compensating
 261          *    for the monitor etc. etc.
 262          *
 263          * but this is inefficient if the source is RGB.  Since we don't
 264          * (currently) care too much about the precise accuracy of the preview's
 265          * colour mapping (and we care more about its speed) we try to short-
 266          * circuit this "ideal" situation in some cases.
 267          *
 268          * The content's specified colour conversion indicates the colourspace
 269          * which the content is in (according to the user).
 270          *
 271          * PlayerVideo::image (bound to PlayerVideo::force) will take the source
 272          * image and convert it (from whatever the user has said it is) to RGB.
 273          */
 274
 275         _frame = _player_video.first->image (bind(&PlayerVideo::force, _1, AV_PIX_FMT_RGB24), false, true);
 276
 277         ImageChanged (_player_video.first);
 278
 279         _video_position = _player_video.second;
 280         _inter_position = _player_video.first->inter_position ();
 281         _inter_size = _player_video.first->inter_size ();
 282
 283         refresh_panel ();
 284
 285         _closed_captions_dialog->update (time());
 286 }
 287
 288 void
 289 FilmViewer::timer ()
 290 {
 291         if (!_film || !_playing) {
 292                 return;
 293         }
 294
 295         get ();
 296         PositionChanged ();
 297         DCPTime const next = _video_position + one_video_frame();
 298
 299         if (next >= _film->length()) {
 300                 stop ();
 301                 Finished ();
 302                 return;
 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 bool
 313 FilmViewer::maybe_draw_background_image (wxPaintDC& dc)
 314 {
 315 #ifdef DCPOMATIC_VARIANT_SWAROOP
 316         optional<boost::filesystem::path> bg = Config::instance()->player_background_image();
 317         if (bg) {
 318                 wxImage image (std_to_wx(bg->string()));
 319                 wxBitmap bitmap (image);
 320                 dc.DrawBitmap (bitmap, max(0, (_panel_size.width - image.GetSize().GetWidth()) / 2), max(0, (_panel_size.height - image.GetSize().GetHeight()) / 2));
 321                 return true;
 322         }
 323 #endif
 324
 325         return false;
 326 }
 327
 328 void
 329 FilmViewer::paint_panel ()
 330 {
 331         wxPaintDC dc (_panel);
 332
 333         if (!_out_size.width || !_out_size.height || (_frame && _out_size != _frame->size())) {
 334                 dc.Clear ();
 335                 return;
 336         }
 337
 338         if (!_frame || !_film) {
 339                 dc.Clear ();
 340                 maybe_draw_background_image (dc);
 341                 return;
 342         }
 343
 344         if (_video_position == DCPTime() && maybe_draw_background_image (dc)) {
 345                 return;
 346         }
 347
 348         wxImage frame (_out_size.width, _out_size.height, _frame->data()[0], true);
 349         wxBitmap frame_bitmap (frame);
 350         dc.DrawBitmap (frame_bitmap, 0, max(0, (_panel_size.height - _out_size.height) / 2));
 351
 352 #ifdef DCPOMATIC_VARIANT_SWAROOP
 353         DCPTime const period = DCPTime::from_seconds(Config::instance()->player_watermark_period() * 60);
 354         int64_t n = _video_position.get() / period.get();
 355         DCPTime from(n * period.get());
 356         DCPTime to = from + DCPTime::from_seconds(Config::instance()->player_watermark_duration() / 1000.0);
 357         if (from <= _video_position && _video_position <= to) {
 358                 if (!_in_watermark) {
 359                         _in_watermark = true;
 360                         _watermark_x = rand() % _panel_size.width;
 361                         _watermark_y = rand() % _panel_size.height;
 362                 }
 363                 dc.SetTextForeground(*wxWHITE);
 364                 string wm = Config::instance()->player_watermark_theatre();
 365                 boost::posix_time::ptime t = boost::posix_time::second_clock::local_time();
 366                 wm += "\n" + boost::posix_time::to_iso_extended_string(t);
 367                 dc.DrawText(std_to_wx(wm), _watermark_x, _watermark_y);
 368         } else {
 369                 _in_watermark = false;
 370         }
 371 #endif
 372
 373         if (_out_size.width < _panel_size.width) {
 374                 /* XXX: these colours are right for GNOME; may need adjusting for other OS */
 375                 wxPen   p (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 376                 wxBrush b (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 377                 dc.SetPen (p);
 378                 dc.SetBrush (b);
 379                 dc.DrawRectangle (_out_size.width, 0, _panel_size.width - _out_size.width, _panel_size.height);
 380         }
 381
 382         if (_out_size.height < _panel_size.height) {
 383                 wxPen   p (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 384                 wxBrush b (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 385                 dc.SetPen (p);
 386                 dc.SetBrush (b);
 387                 int const gap = (_panel_size.height - _out_size.height) / 2;
 388                 dc.DrawRectangle (0, 0, _panel_size.width, gap);
 389                 dc.DrawRectangle (0, gap + _out_size.height + 1, _panel_size.width, gap);
 390         }
 391
 392         if (_outline_content) {
 393                 wxPen p (wxColour (255, 0, 0), 2);
 394                 dc.SetPen (p);
 395                 dc.SetBrush (*wxTRANSPARENT_BRUSH);
 396                 dc.DrawRectangle (_inter_position.x, _inter_position.y + (_panel_size.height - _out_size.height) / 2, _inter_size.width, _inter_size.height);
 397         }
 398 }
 399
 400 void
 401 FilmViewer::set_outline_content (bool o)
 402 {
 403         _outline_content = o;
 404         refresh_panel ();
 405 }
 406
 407 void
 408 FilmViewer::set_eyes (Eyes e)
 409 {
 410         _eyes = e;
 411         slow_refresh ();
 412 }
 413
 414 void
 415 FilmViewer::panel_sized (wxSizeEvent& ev)
 416 {
 417         _panel_size.width = ev.GetSize().GetWidth();
 418         _panel_size.height = ev.GetSize().GetHeight();
 419
 420         calculate_sizes ();
 421         if (!quick_refresh()) {
 422                 slow_refresh ();
 423         }
 424         PositionChanged ();
 425 }
 426
 427 void
 428 FilmViewer::calculate_sizes ()
 429 {
 430         if (!_film || !_player) {
 431                 return;
 432         }
 433
 434         Ratio const * container = _film->container ();
 435
 436         float const panel_ratio = _panel_size.ratio ();
 437         float const film_ratio = container ? container->ratio () : 1.78;
 438
 439         if (panel_ratio < film_ratio) {
 440                 /* panel is less widscreen than the film; clamp width */
 441                 _out_size.width = _panel_size.width;
 442                 _out_size.height = lrintf (_out_size.width / film_ratio);
 443         } else {
 444                 /* panel is more widescreen than the film; clamp height */
 445                 _out_size.height = _panel_size.height;
 446                 _out_size.width = lrintf (_out_size.height * film_ratio);
 447         }
 448
 449         /* Catch silly values */
 450         _out_size.width = max (64, _out_size.width);
 451         _out_size.height = max (64, _out_size.height);
 452
 453         _player->set_video_container_size (_out_size);
 454 }
 455
 456 void
 457 FilmViewer::start ()
 458 {
 459         if (!_film) {
 460                 return;
 461         }
 462
 463         optional<bool> v = PlaybackPermitted ();
 464         if (v && !*v) {
 465                 /* Computer says no */
 466                 return;
 467         }
 468
 469         if (_audio.isStreamOpen()) {
 470                 _audio.setStreamTime (_video_position.seconds());
 471                 _audio.startStream ();
 472         }
 473
 474         _playing = true;
 475         _dropped = 0;
 476         timer ();
 477         Started (position());
 478 }
 479
 480 bool
 481 FilmViewer::stop ()
 482 {
 483         if (_audio.isStreamRunning()) {
 484                 /* stop stream and discard any remaining queued samples */
 485                 _audio.abortStream ();
 486         }
 487
 488         if (!_playing) {
 489                 return false;
 490         }
 491
 492         _playing = false;
 493         Stopped (position());
 494         return true;
 495 }
 496
 497 void
 498 FilmViewer::player_change (ChangeType type, int property, bool frequent)
 499 {
 500         if (type != CHANGE_TYPE_DONE || frequent) {
 501                 return;
 502         }
 503
 504         if (_coalesce_player_changes) {
 505                 _pending_player_changes.push_back (property);
 506                 return;
 507         }
 508
 509         calculate_sizes ();
 510         bool refreshed = false;
 511         if (
 512                 property == VideoContentProperty::CROP ||
 513                 property == VideoContentProperty::SCALE ||
 514                 property == VideoContentProperty::FADE_IN ||
 515                 property == VideoContentProperty::FADE_OUT ||
 516                 property == VideoContentProperty::COLOUR_CONVERSION ||
 517                 property == PlayerProperty::VIDEO_CONTAINER_SIZE ||
 518                 property == PlayerProperty::FILM_CONTAINER
 519                 ) {
 520                 refreshed = quick_refresh ();
 521         }
 522
 523         if (!refreshed) {
 524                 slow_refresh ();
 525         }
 526         PositionChanged ();
 527 }
 528
 529 void
 530 FilmViewer::film_change (ChangeType type, Film::Property p)
 531 {
 532         if (type == CHANGE_TYPE_DONE && p == Film::AUDIO_CHANNELS) {
 533                 recreate_butler ();
 534         }
 535 }
 536
 537 /** Re-get the current frame slowly by seeking */
 538 void
 539 FilmViewer::slow_refresh ()
 540 {
 541         seek (_video_position, true);
 542 }
 543
 544 /** Try to re-get the current frame quickly by resetting the metadata
 545  *  in the PlayerVideo that we used last time.
 546  *  @return true if this was possible, false if not.
 547  */
 548 bool
 549 FilmViewer::quick_refresh ()
 550 {
 551         if (!_player_video.first) {
 552                 return false;
 553         }
 554
 555         if (!_player_video.first->reset_metadata (_film, _player->video_container_size(), _film->frame_size())) {
 556                 return false;
 557         }
 558
 559         display_player_video ();
 560         return true;
 561 }
 562
 563 void
 564 FilmViewer::seek (shared_ptr<Content> content, ContentTime t, bool accurate)
 565 {
 566         optional<DCPTime> dt = _player->content_time_to_dcp (content, t);
 567         if (dt) {
 568                 seek (*dt, accurate);
 569         }
 570 }
 571
 572 void
 573 FilmViewer::set_coalesce_player_changes (bool c)
 574 {
 575         _coalesce_player_changes = c;
 576
 577         if (!c) {
 578                 BOOST_FOREACH (int i, _pending_player_changes) {
 579                         player_change (CHANGE_TYPE_DONE, i, false);
 580                 }
 581                 _pending_player_changes.clear ();
 582         }
 583 }
 584
 585 void
 586 FilmViewer::seek (DCPTime t, bool accurate)
 587 {
 588         if (!_butler) {
 589                 return;
 590         }
 591
 592         if (t < DCPTime ()) {
 593                 t = DCPTime ();
 594         }
 595
 596         if (t >= _film->length ()) {
 597                 t = _film->length ();
 598         }
 599
 600         bool const was_running = stop ();
 601
 602         _closed_captions_dialog->clear ();
 603         _butler->seek (t, accurate);
 604         get ();
 605
 606         if (was_running) {
 607                 start ();
 608         }
 609
 610         PositionChanged ();
 611 }
 612
 613 void
 614 FilmViewer::config_changed (Config::Property p)
 615 {
 616 #ifdef DCPOMATIC_VARIANT_SWAROOP
 617         if (p == Config::PLAYER_BACKGROUND_IMAGE) {
 618                 refresh_panel ();
 619                 return;
 620         }
 621 #endif
 622
 623         if (p != Config::SOUND && p != Config::SOUND_OUTPUT) {
 624                 return;
 625         }
 626
 627         if (_audio.isStreamOpen ()) {
 628                 _audio.closeStream ();
 629         }
 630
 631         if (Config::instance()->sound() && _audio.getDeviceCount() > 0) {
 632                 unsigned int st = 0;
 633                 if (Config::instance()->sound_output()) {
 634                         while (st < _audio.getDeviceCount()) {
 635                                 if (_audio.getDeviceInfo(st).name == Config::instance()->sound_output().get()) {
 636                                         break;
 637                                 }
 638                                 ++st;
 639                         }
 640                         if (st == _audio.getDeviceCount()) {
 641                                 st = _audio.getDefaultOutputDevice();
 642                         }
 643                 } else {
 644                         st = _audio.getDefaultOutputDevice();
 645                 }
 646
 647                 _audio_channels = _audio.getDeviceInfo(st).outputChannels;
 648
 649                 RtAudio::StreamParameters sp;
 650                 sp.deviceId = st;
 651                 sp.nChannels = _audio_channels;
 652                 sp.firstChannel = 0;
 653                 try {
 654                         _audio.openStream (&sp, 0, RTAUDIO_FLOAT32, 48000, &_audio_block_size, &rtaudio_callback, this);
 655 #ifdef DCPOMATIC_USE_RTERROR
 656                 } catch (RtError& e) {
 657 #else
 658                 } catch (RtAudioError& e) {
 659 #endif
 660                         error_dialog (
 661                                 _panel,
 662                                 _("Could not set up audio output.  There will be no audio during the preview."), std_to_wx(e.what())
 663                                 );
 664                 }
 665                 recreate_butler ();
 666
 667         } else {
 668                 _audio_channels = 0;
 669                 recreate_butler ();
 670         }
 671 }
 672
 673 DCPTime
 674 FilmViewer::uncorrected_time () const
 675 {
 676         if (_audio.isStreamRunning ()) {
 677                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime());
 678         }
 679
 680         return _video_position;
 681 }
 682
 683 DCPTime
 684 FilmViewer::time () const
 685 {
 686         if (_audio.isStreamRunning ()) {
 687                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime ()) -
 688                         DCPTime::from_frames (average_latency(), _film->audio_frame_rate());
 689         }
 690
 691         return _video_position;
 692 }
 693
 694 int
 695 FilmViewer::audio_callback (void* out_p, unsigned int frames)
 696 {
 697         while (true) {
 698                 optional<DCPTime> t = _butler->get_audio (reinterpret_cast<float*> (out_p), frames);
 699                 if (!t || DCPTime(uncorrected_time() - *t) < one_video_frame()) {
 700                         /* There was an underrun or this audio is on time; carry on */
 701                         break;
 702                 }
 703                 /* The audio we just got was (very) late; drop it and get some more. */
 704         }
 705
 706         boost::mutex::scoped_lock lm (_latency_history_mutex, boost::try_to_lock);
 707         if (lm) {
 708                 _latency_history.push_back (_audio.getStreamLatency ());
 709                 if (_latency_history.size() > static_cast<size_t> (_latency_history_count)) {
 710                         _latency_history.pop_front ();
 711                 }
 712         }
 713
 714         return 0;
 715 }
 716
 717 Frame
 718 FilmViewer::average_latency () const
 719 {
 720         boost::mutex::scoped_lock lm (_latency_history_mutex);
 721         if (_latency_history.empty()) {
 722                 return 0;
 723         }
 724
 725         Frame total = 0;
 726         BOOST_FOREACH (Frame i, _latency_history) {
 727                 total += i;
 728         }
 729
 730         return total / _latency_history.size();
 731 }
 732
 733 void
 734 FilmViewer::set_dcp_decode_reduction (optional<int> reduction)
 735 {
 736         _dcp_decode_reduction = reduction;
 737         if (_player) {
 738                 _player->set_dcp_decode_reduction (reduction);
 739         }
 740 }
 741
 742 optional<int>
 743 FilmViewer::dcp_decode_reduction () const
 744 {
 745         return _dcp_decode_reduction;
 746 }
 747
 748 DCPTime
 749 FilmViewer::one_video_frame () const
 750 {
 751         return DCPTime::from_frames (1, _film->video_frame_rate());
 752 }
 753
 754 /** Open a dialog box showing our film's closed captions */
 755 void
 756 FilmViewer::show_closed_captions ()
 757 {
 758         _closed_captions_dialog->Show();
 759 }
 760
 761 void
 762 FilmViewer::seek_by (DCPTime by, bool accurate)
 763 {
 764         seek (_video_position + by, accurate);
 765 }
 766
 767 void
 768 FilmViewer::set_pad_black (bool p)
 769 {
 770         _pad_black = p;
 771 }