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, bind(&PlayerVideo::force, _1, AV_PIX_FMT_RGB24), false, true));
 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::force) 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 (bind(&PlayerVideo::force, _1, AV_PIX_FMT_RGB24), false, true);
 275
 276         ImageChanged (_player_video.first);
 277
 278         _video_position = _player_video.second;
 279         _inter_position = _player_video.first->inter_position ();
 280         _inter_size = _player_video.first->inter_size ();
 281
 282         refresh_panel ();
 283
 284         _closed_captions_dialog->update (time());
 285 }
 286
 287 void
 288 FilmViewer::timer ()
 289 {
 290         if (!_film || !_playing) {
 291                 return;
 292         }
 293
 294         get ();
 295         PositionChanged ();
 296         DCPTime const next = _video_position + one_video_frame();
 297
 298         if (next >= _film->length()) {
 299                 stop ();
 300         }
 301
 302         _timer.Start (max ((next.seconds() - time().seconds()) * 1000, 1.0), wxTIMER_ONE_SHOT);
 303
 304         if (_butler) {
 305                 _butler->rethrow ();
 306         }
 307 }
 308
 309 bool
 310 FilmViewer::maybe_draw_background_image (wxPaintDC& dc)
 311 {
 312 #ifdef DCPOMATIC_VARIANT_SWAROOP
 313         optional<boost::filesystem::path> bg = Config::instance()->player_background_image();
 314         if (bg) {
 315                 wxImage image (std_to_wx(bg->string()));
 316                 wxBitmap bitmap (image);
 317                 dc.DrawBitmap (bitmap, max(0, (_panel_size.width - image.GetSize().GetWidth()) / 2), max(0, (_panel_size.height - image.GetSize().GetHeight()) / 2));
 318                 return true;
 319         }
 320 #endif
 321
 322         return false;
 323 }
 324
 325 void
 326 FilmViewer::paint_panel ()
 327 {
 328         wxPaintDC dc (_panel);
 329
 330         if (!_frame || !_film || !_out_size.width || !_out_size.height || _out_size != _frame->size()) {
 331                 dc.Clear ();
 332                 maybe_draw_background_image (dc);
 333                 return;
 334         }
 335
 336         if (_video_position == DCPTime() && maybe_draw_background_image (dc)) {
 337                 return;
 338         }
 339
 340         wxImage frame (_out_size.width, _out_size.height, _frame->data()[0], true);
 341         wxBitmap frame_bitmap (frame);
 342         dc.DrawBitmap (frame_bitmap, 0, max(0, (_panel_size.height - _out_size.height) / 2));
 343
 344 #ifdef DCPOMATIC_VARIANT_SWAROOP
 345         DCPTime const period = DCPTime::from_seconds(Config::instance()->player_watermark_period() * 60);
 346         int64_t n = _video_position.get() / period.get();
 347         DCPTime from(n * period.get());
 348         DCPTime to = from + DCPTime::from_seconds(Config::instance()->player_watermark_duration() / 1000.0);
 349         if (from <= _video_position && _video_position <= to) {
 350                 if (!_in_watermark) {
 351                         _in_watermark = true;
 352                         _watermark_x = rand() % _panel_size.width;
 353                         _watermark_y = rand() % _panel_size.height;
 354                 }
 355                 dc.SetTextForeground(*wxWHITE);
 356                 string wm = Config::instance()->player_watermark_theatre();
 357                 boost::posix_time::ptime t = boost::posix_time::second_clock::local_time();
 358                 wm += "\n" + boost::posix_time::to_iso_extended_string(t);
 359                 dc.DrawText(std_to_wx(wm), _watermark_x, _watermark_y);
 360         } else {
 361                 _in_watermark = false;
 362         }
 363 #endif
 364
 365         if (_out_size.width < _panel_size.width) {
 366                 /* XXX: these colours are right for GNOME; may need adjusting for other OS */
 367                 wxPen   p (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 368                 wxBrush b (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 369                 dc.SetPen (p);
 370                 dc.SetBrush (b);
 371                 dc.DrawRectangle (_out_size.width, 0, _panel_size.width - _out_size.width, _panel_size.height);
 372         }
 373
 374         if (_out_size.height < _panel_size.height) {
 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                 int const gap = (_panel_size.height - _out_size.height) / 2;
 380                 dc.DrawRectangle (0, 0, _panel_size.width, gap);
 381                 dc.DrawRectangle (0, gap + _out_size.height + 1, _panel_size.width, gap);
 382         }
 383
 384         if (_outline_content) {
 385                 wxPen p (wxColour (255, 0, 0), 2);
 386                 dc.SetPen (p);
 387                 dc.SetBrush (*wxTRANSPARENT_BRUSH);
 388                 dc.DrawRectangle (_inter_position.x, _inter_position.y + (_panel_size.height - _out_size.height) / 2, _inter_size.width, _inter_size.height);
 389         }
 390 }
 391
 392 void
 393 FilmViewer::set_outline_content (bool o)
 394 {
 395         _outline_content = o;
 396         refresh_panel ();
 397 }
 398
 399 void
 400 FilmViewer::set_eyes (Eyes e)
 401 {
 402         _eyes = e;
 403         slow_refresh ();
 404 }
 405
 406 void
 407 FilmViewer::panel_sized (wxSizeEvent& ev)
 408 {
 409         _panel_size.width = ev.GetSize().GetWidth();
 410         _panel_size.height = ev.GetSize().GetHeight();
 411
 412         calculate_sizes ();
 413         if (!quick_refresh()) {
 414                 slow_refresh ();
 415         }
 416         PositionChanged ();
 417 }
 418
 419 void
 420 FilmViewer::calculate_sizes ()
 421 {
 422         if (!_film || !_player) {
 423                 return;
 424         }
 425
 426         Ratio const * container = _film->container ();
 427
 428         float const panel_ratio = _panel_size.ratio ();
 429         float const film_ratio = container ? container->ratio () : 1.78;
 430
 431         if (panel_ratio < film_ratio) {
 432                 /* panel is less widscreen than the film; clamp width */
 433                 _out_size.width = _panel_size.width;
 434                 _out_size.height = lrintf (_out_size.width / film_ratio);
 435         } else {
 436                 /* panel is more widescreen than the film; clamp height */
 437                 _out_size.height = _panel_size.height;
 438                 _out_size.width = lrintf (_out_size.height * film_ratio);
 439         }
 440
 441         /* Catch silly values */
 442         _out_size.width = max (64, _out_size.width);
 443         _out_size.height = max (64, _out_size.height);
 444
 445         _player->set_video_container_size (_out_size);
 446 }
 447
 448 void
 449 FilmViewer::start ()
 450 {
 451         if (!_film) {
 452                 return;
 453         }
 454
 455         optional<bool> v = PlaybackPermitted ();
 456         if (v && !*v) {
 457                 /* Computer says no */
 458                 return;
 459         }
 460
 461         if (_audio.isStreamOpen()) {
 462                 _audio.setStreamTime (_video_position.seconds());
 463                 _audio.startStream ();
 464         }
 465
 466         _playing = true;
 467         _dropped = 0;
 468         timer ();
 469         Started (position());
 470 }
 471
 472 bool
 473 FilmViewer::stop ()
 474 {
 475         if (_audio.isStreamRunning()) {
 476                 /* stop stream and discard any remaining queued samples */
 477                 _audio.abortStream ();
 478         }
 479
 480         if (!_playing) {
 481                 return false;
 482         }
 483
 484         _playing = false;
 485         Stopped (position());
 486         return true;
 487 }
 488
 489 void
 490 FilmViewer::player_change (ChangeType type, int property, bool frequent)
 491 {
 492         if (type != CHANGE_TYPE_DONE || frequent) {
 493                 return;
 494         }
 495
 496         if (_coalesce_player_changes) {
 497                 _pending_player_changes.push_back (property);
 498                 return;
 499         }
 500
 501         calculate_sizes ();
 502         bool refreshed = false;
 503         if (
 504                 property == VideoContentProperty::CROP ||
 505                 property == VideoContentProperty::SCALE ||
 506                 property == VideoContentProperty::FADE_IN ||
 507                 property == VideoContentProperty::FADE_OUT ||
 508                 property == VideoContentProperty::COLOUR_CONVERSION ||
 509                 property == PlayerProperty::VIDEO_CONTAINER_SIZE ||
 510                 property == PlayerProperty::FILM_CONTAINER
 511                 ) {
 512                 refreshed = quick_refresh ();
 513         }
 514
 515         if (!refreshed) {
 516                 slow_refresh ();
 517         }
 518         PositionChanged ();
 519 }
 520
 521 void
 522 FilmViewer::film_change (ChangeType type, Film::Property p)
 523 {
 524         if (type == CHANGE_TYPE_DONE && p == Film::AUDIO_CHANNELS) {
 525                 recreate_butler ();
 526         }
 527 }
 528
 529 /** Re-get the current frame slowly by seeking */
 530 void
 531 FilmViewer::slow_refresh ()
 532 {
 533         seek (_video_position, true);
 534 }
 535
 536 /** Try to re-get the current frame quickly by resetting the metadata
 537  *  in the PlayerVideo that we used last time.
 538  *  @return true if this was possible, false if not.
 539  */
 540 bool
 541 FilmViewer::quick_refresh ()
 542 {
 543         if (!_player_video.first) {
 544                 return false;
 545         }
 546
 547         if (!_player_video.first->reset_metadata (_film, _player->video_container_size(), _film->frame_size())) {
 548                 return false;
 549         }
 550
 551         display_player_video ();
 552         return true;
 553 }
 554
 555 void
 556 FilmViewer::seek (shared_ptr<Content> content, ContentTime t, bool accurate)
 557 {
 558         optional<DCPTime> dt = _player->content_time_to_dcp (content, t);
 559         if (dt) {
 560                 seek (*dt, accurate);
 561         }
 562 }
 563
 564 void
 565 FilmViewer::set_coalesce_player_changes (bool c)
 566 {
 567         _coalesce_player_changes = c;
 568
 569         if (!c) {
 570                 BOOST_FOREACH (int i, _pending_player_changes) {
 571                         player_change (CHANGE_TYPE_DONE, i, false);
 572                 }
 573                 _pending_player_changes.clear ();
 574         }
 575 }
 576
 577 void
 578 FilmViewer::seek (DCPTime t, bool accurate)
 579 {
 580         if (!_butler) {
 581                 return;
 582         }
 583
 584         if (t < DCPTime ()) {
 585                 t = DCPTime ();
 586         }
 587
 588         if (t >= _film->length ()) {
 589                 t = _film->length ();
 590         }
 591
 592         bool const was_running = stop ();
 593
 594         _closed_captions_dialog->clear ();
 595         _butler->seek (t, accurate);
 596         get ();
 597
 598         if (was_running) {
 599                 start ();
 600         }
 601
 602         PositionChanged ();
 603         Seeked (position());
 604 }
 605
 606 void
 607 FilmViewer::config_changed (Config::Property p)
 608 {
 609 #ifdef DCPOMATIC_VARIANT_SWAROOP
 610         if (p == Config::PLAYER_BACKGROUND_IMAGE) {
 611                 refresh_panel ();
 612                 return;
 613         }
 614 #endif
 615
 616         if (p != Config::SOUND && p != Config::SOUND_OUTPUT) {
 617                 return;
 618         }
 619
 620         if (_audio.isStreamOpen ()) {
 621                 _audio.closeStream ();
 622         }
 623
 624         if (Config::instance()->sound() && _audio.getDeviceCount() > 0) {
 625                 unsigned int st = 0;
 626                 if (Config::instance()->sound_output()) {
 627                         while (st < _audio.getDeviceCount()) {
 628                                 if (_audio.getDeviceInfo(st).name == Config::instance()->sound_output().get()) {
 629                                         break;
 630                                 }
 631                                 ++st;
 632                         }
 633                         if (st == _audio.getDeviceCount()) {
 634                                 st = _audio.getDefaultOutputDevice();
 635                         }
 636                 } else {
 637                         st = _audio.getDefaultOutputDevice();
 638                 }
 639
 640                 _audio_channels = _audio.getDeviceInfo(st).outputChannels;
 641
 642                 RtAudio::StreamParameters sp;
 643                 sp.deviceId = st;
 644                 sp.nChannels = _audio_channels;
 645                 sp.firstChannel = 0;
 646                 try {
 647                         _audio.openStream (&sp, 0, RTAUDIO_FLOAT32, 48000, &_audio_block_size, &rtaudio_callback, this);
 648 #ifdef DCPOMATIC_USE_RTERROR
 649                 } catch (RtError& e) {
 650 #else
 651                 } catch (RtAudioError& e) {
 652 #endif
 653                         error_dialog (
 654                                 _panel,
 655                                 _("Could not set up audio output.  There will be no audio during the preview."), std_to_wx(e.what())
 656                                 );
 657                 }
 658                 recreate_butler ();
 659
 660         } else {
 661                 _audio_channels = 0;
 662                 recreate_butler ();
 663         }
 664 }
 665
 666 DCPTime
 667 FilmViewer::uncorrected_time () const
 668 {
 669         if (_audio.isStreamRunning ()) {
 670                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime());
 671         }
 672
 673         return _video_position;
 674 }
 675
 676 DCPTime
 677 FilmViewer::time () const
 678 {
 679         if (_audio.isStreamRunning ()) {
 680                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime ()) -
 681                         DCPTime::from_frames (average_latency(), _film->audio_frame_rate());
 682         }
 683
 684         return _video_position;
 685 }
 686
 687 int
 688 FilmViewer::audio_callback (void* out_p, unsigned int frames)
 689 {
 690         while (true) {
 691                 optional<DCPTime> t = _butler->get_audio (reinterpret_cast<float*> (out_p), frames);
 692                 if (!t || DCPTime(uncorrected_time() - *t) < one_video_frame()) {
 693                         /* There was an underrun or this audio is on time; carry on */
 694                         break;
 695                 }
 696                 /* The audio we just got was (very) late; drop it and get some more. */
 697         }
 698
 699         boost::mutex::scoped_lock lm (_latency_history_mutex, boost::try_to_lock);
 700         if (lm) {
 701                 _latency_history.push_back (_audio.getStreamLatency ());
 702                 if (_latency_history.size() > static_cast<size_t> (_latency_history_count)) {
 703                         _latency_history.pop_front ();
 704                 }
 705         }
 706
 707         return 0;
 708 }
 709
 710 Frame
 711 FilmViewer::average_latency () const
 712 {
 713         boost::mutex::scoped_lock lm (_latency_history_mutex);
 714         if (_latency_history.empty()) {
 715                 return 0;
 716         }
 717
 718         Frame total = 0;
 719         BOOST_FOREACH (Frame i, _latency_history) {
 720                 total += i;
 721         }
 722
 723         return total / _latency_history.size();
 724 }
 725
 726 void
 727 FilmViewer::set_dcp_decode_reduction (optional<int> reduction)
 728 {
 729         _dcp_decode_reduction = reduction;
 730         if (_player) {
 731                 _player->set_dcp_decode_reduction (reduction);
 732         }
 733 }
 734
 735 optional<int>
 736 FilmViewer::dcp_decode_reduction () const
 737 {
 738         return _dcp_decode_reduction;
 739 }
 740
 741 DCPTime
 742 FilmViewer::one_video_frame () const
 743 {
 744         return DCPTime::from_frames (1, _film->video_frame_rate());
 745 }
 746
 747 /** Open a dialog box showing our film's closed captions */
 748 void
 749 FilmViewer::show_closed_captions ()
 750 {
 751         _closed_captions_dialog->Show();
 752 }
 753
 754 void
 755 FilmViewer::seek_by (DCPTime by, bool accurate)
 756 {
 757         seek (_video_position + by, accurate);
 758 }
 759
 760 void
 761 FilmViewer::set_pad_black (bool p)
 762 {
 763         _pad_black = p;
 764 }