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 (!_frame || !_film || !_out_size.width || !_out_size.height || _out_size != _frame->size()) {
 334                 dc.Clear ();
 335                 maybe_draw_background_image (dc);
 336                 return;
 337         }
 338
 339         if (_video_position == DCPTime() && maybe_draw_background_image (dc)) {
 340                 return;
 341         }
 342
 343         wxImage frame (_out_size.width, _out_size.height, _frame->data()[0], true);
 344         wxBitmap frame_bitmap (frame);
 345         dc.DrawBitmap (frame_bitmap, 0, max(0, (_panel_size.height - _out_size.height) / 2));
 346
 347 #ifdef DCPOMATIC_VARIANT_SWAROOP
 348         DCPTime const period = DCPTime::from_seconds(Config::instance()->player_watermark_period() * 60);
 349         int64_t n = _video_position.get() / period.get();
 350         DCPTime from(n * period.get());
 351         DCPTime to = from + DCPTime::from_seconds(Config::instance()->player_watermark_duration() / 1000.0);
 352         if (from <= _video_position && _video_position <= to) {
 353                 if (!_in_watermark) {
 354                         _in_watermark = true;
 355                         _watermark_x = rand() % _panel_size.width;
 356                         _watermark_y = rand() % _panel_size.height;
 357                 }
 358                 dc.SetTextForeground(*wxWHITE);
 359                 string wm = Config::instance()->player_watermark_theatre();
 360                 boost::posix_time::ptime t = boost::posix_time::second_clock::local_time();
 361                 wm += "\n" + boost::posix_time::to_iso_extended_string(t);
 362                 dc.DrawText(std_to_wx(wm), _watermark_x, _watermark_y);
 363         } else {
 364                 _in_watermark = false;
 365         }
 366 #endif
 367
 368         if (_out_size.width < _panel_size.width) {
 369                 /* XXX: these colours are right for GNOME; may need adjusting for other OS */
 370                 wxPen   p (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 371                 wxBrush b (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 372                 dc.SetPen (p);
 373                 dc.SetBrush (b);
 374                 dc.DrawRectangle (_out_size.width, 0, _panel_size.width - _out_size.width, _panel_size.height);
 375         }
 376
 377         if (_out_size.height < _panel_size.height) {
 378                 wxPen   p (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 379                 wxBrush b (_pad_black ? wxColour(0, 0, 0) : wxColour(240, 240, 240));
 380                 dc.SetPen (p);
 381                 dc.SetBrush (b);
 382                 int const gap = (_panel_size.height - _out_size.height) / 2;
 383                 dc.DrawRectangle (0, 0, _panel_size.width, gap);
 384                 dc.DrawRectangle (0, gap + _out_size.height + 1, _panel_size.width, gap);
 385         }
 386
 387         if (_outline_content) {
 388                 wxPen p (wxColour (255, 0, 0), 2);
 389                 dc.SetPen (p);
 390                 dc.SetBrush (*wxTRANSPARENT_BRUSH);
 391                 dc.DrawRectangle (_inter_position.x, _inter_position.y + (_panel_size.height - _out_size.height) / 2, _inter_size.width, _inter_size.height);
 392         }
 393 }
 394
 395 void
 396 FilmViewer::set_outline_content (bool o)
 397 {
 398         _outline_content = o;
 399         refresh_panel ();
 400 }
 401
 402 void
 403 FilmViewer::set_eyes (Eyes e)
 404 {
 405         _eyes = e;
 406         slow_refresh ();
 407 }
 408
 409 void
 410 FilmViewer::panel_sized (wxSizeEvent& ev)
 411 {
 412         _panel_size.width = ev.GetSize().GetWidth();
 413         _panel_size.height = ev.GetSize().GetHeight();
 414
 415         calculate_sizes ();
 416         if (!quick_refresh()) {
 417                 slow_refresh ();
 418         }
 419         PositionChanged ();
 420 }
 421
 422 void
 423 FilmViewer::calculate_sizes ()
 424 {
 425         if (!_film || !_player) {
 426                 return;
 427         }
 428
 429         Ratio const * container = _film->container ();
 430
 431         float const panel_ratio = _panel_size.ratio ();
 432         float const film_ratio = container ? container->ratio () : 1.78;
 433
 434         if (panel_ratio < film_ratio) {
 435                 /* panel is less widscreen than the film; clamp width */
 436                 _out_size.width = _panel_size.width;
 437                 _out_size.height = lrintf (_out_size.width / film_ratio);
 438         } else {
 439                 /* panel is more widescreen than the film; clamp height */
 440                 _out_size.height = _panel_size.height;
 441                 _out_size.width = lrintf (_out_size.height * film_ratio);
 442         }
 443
 444         /* Catch silly values */
 445         _out_size.width = max (64, _out_size.width);
 446         _out_size.height = max (64, _out_size.height);
 447
 448         _player->set_video_container_size (_out_size);
 449 }
 450
 451 void
 452 FilmViewer::start ()
 453 {
 454         if (!_film) {
 455                 return;
 456         }
 457
 458         optional<bool> v = PlaybackPermitted ();
 459         if (v && !*v) {
 460                 /* Computer says no */
 461                 return;
 462         }
 463
 464         if (_audio.isStreamOpen()) {
 465                 _audio.setStreamTime (_video_position.seconds());
 466                 _audio.startStream ();
 467         }
 468
 469         _playing = true;
 470         _dropped = 0;
 471         timer ();
 472         Started (position());
 473 }
 474
 475 bool
 476 FilmViewer::stop ()
 477 {
 478         if (_audio.isStreamRunning()) {
 479                 /* stop stream and discard any remaining queued samples */
 480                 _audio.abortStream ();
 481         }
 482
 483         if (!_playing) {
 484                 return false;
 485         }
 486
 487         _playing = false;
 488         Stopped (position());
 489         return true;
 490 }
 491
 492 void
 493 FilmViewer::player_change (ChangeType type, int property, bool frequent)
 494 {
 495         if (type != CHANGE_TYPE_DONE || frequent) {
 496                 return;
 497         }
 498
 499         if (_coalesce_player_changes) {
 500                 _pending_player_changes.push_back (property);
 501                 return;
 502         }
 503
 504         calculate_sizes ();
 505         bool refreshed = false;
 506         if (
 507                 property == VideoContentProperty::CROP ||
 508                 property == VideoContentProperty::SCALE ||
 509                 property == VideoContentProperty::FADE_IN ||
 510                 property == VideoContentProperty::FADE_OUT ||
 511                 property == VideoContentProperty::COLOUR_CONVERSION ||
 512                 property == PlayerProperty::VIDEO_CONTAINER_SIZE ||
 513                 property == PlayerProperty::FILM_CONTAINER
 514                 ) {
 515                 refreshed = quick_refresh ();
 516         }
 517
 518         if (!refreshed) {
 519                 slow_refresh ();
 520         }
 521         PositionChanged ();
 522 }
 523
 524 void
 525 FilmViewer::film_change (ChangeType type, Film::Property p)
 526 {
 527         if (type == CHANGE_TYPE_DONE && p == Film::AUDIO_CHANNELS) {
 528                 recreate_butler ();
 529         }
 530 }
 531
 532 /** Re-get the current frame slowly by seeking */
 533 void
 534 FilmViewer::slow_refresh ()
 535 {
 536         seek (_video_position, true);
 537 }
 538
 539 /** Try to re-get the current frame quickly by resetting the metadata
 540  *  in the PlayerVideo that we used last time.
 541  *  @return true if this was possible, false if not.
 542  */
 543 bool
 544 FilmViewer::quick_refresh ()
 545 {
 546         if (!_player_video.first) {
 547                 return false;
 548         }
 549
 550         if (!_player_video.first->reset_metadata (_film, _player->video_container_size(), _film->frame_size())) {
 551                 return false;
 552         }
 553
 554         display_player_video ();
 555         return true;
 556 }
 557
 558 void
 559 FilmViewer::seek (shared_ptr<Content> content, ContentTime t, bool accurate)
 560 {
 561         optional<DCPTime> dt = _player->content_time_to_dcp (content, t);
 562         if (dt) {
 563                 seek (*dt, accurate);
 564         }
 565 }
 566
 567 void
 568 FilmViewer::set_coalesce_player_changes (bool c)
 569 {
 570         _coalesce_player_changes = c;
 571
 572         if (!c) {
 573                 BOOST_FOREACH (int i, _pending_player_changes) {
 574                         player_change (CHANGE_TYPE_DONE, i, false);
 575                 }
 576                 _pending_player_changes.clear ();
 577         }
 578 }
 579
 580 void
 581 FilmViewer::seek (DCPTime t, bool accurate)
 582 {
 583         if (!_butler) {
 584                 return;
 585         }
 586
 587         if (t < DCPTime ()) {
 588                 t = DCPTime ();
 589         }
 590
 591         if (t >= _film->length ()) {
 592                 t = _film->length ();
 593         }
 594
 595         bool const was_running = stop ();
 596
 597         _closed_captions_dialog->clear ();
 598         _butler->seek (t, accurate);
 599         get ();
 600
 601         if (was_running) {
 602                 start ();
 603         }
 604
 605         PositionChanged ();
 606 }
 607
 608 void
 609 FilmViewer::config_changed (Config::Property p)
 610 {
 611 #ifdef DCPOMATIC_VARIANT_SWAROOP
 612         if (p == Config::PLAYER_BACKGROUND_IMAGE) {
 613                 refresh_panel ();
 614                 return;
 615         }
 616 #endif
 617
 618         if (p != Config::SOUND && p != Config::SOUND_OUTPUT) {
 619                 return;
 620         }
 621
 622         if (_audio.isStreamOpen ()) {
 623                 _audio.closeStream ();
 624         }
 625
 626         if (Config::instance()->sound() && _audio.getDeviceCount() > 0) {
 627                 unsigned int st = 0;
 628                 if (Config::instance()->sound_output()) {
 629                         while (st < _audio.getDeviceCount()) {
 630                                 if (_audio.getDeviceInfo(st).name == Config::instance()->sound_output().get()) {
 631                                         break;
 632                                 }
 633                                 ++st;
 634                         }
 635                         if (st == _audio.getDeviceCount()) {
 636                                 st = _audio.getDefaultOutputDevice();
 637                         }
 638                 } else {
 639                         st = _audio.getDefaultOutputDevice();
 640                 }
 641
 642                 _audio_channels = _audio.getDeviceInfo(st).outputChannels;
 643
 644                 RtAudio::StreamParameters sp;
 645                 sp.deviceId = st;
 646                 sp.nChannels = _audio_channels;
 647                 sp.firstChannel = 0;
 648                 try {
 649                         _audio.openStream (&sp, 0, RTAUDIO_FLOAT32, 48000, &_audio_block_size, &rtaudio_callback, this);
 650 #ifdef DCPOMATIC_USE_RTERROR
 651                 } catch (RtError& e) {
 652 #else
 653                 } catch (RtAudioError& e) {
 654 #endif
 655                         error_dialog (
 656                                 _panel,
 657                                 _("Could not set up audio output.  There will be no audio during the preview."), std_to_wx(e.what())
 658                                 );
 659                 }
 660                 recreate_butler ();
 661
 662         } else {
 663                 _audio_channels = 0;
 664                 recreate_butler ();
 665         }
 666 }
 667
 668 DCPTime
 669 FilmViewer::uncorrected_time () const
 670 {
 671         if (_audio.isStreamRunning ()) {
 672                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime());
 673         }
 674
 675         return _video_position;
 676 }
 677
 678 DCPTime
 679 FilmViewer::time () const
 680 {
 681         if (_audio.isStreamRunning ()) {
 682                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime ()) -
 683                         DCPTime::from_frames (average_latency(), _film->audio_frame_rate());
 684         }
 685
 686         return _video_position;
 687 }
 688
 689 int
 690 FilmViewer::audio_callback (void* out_p, unsigned int frames)
 691 {
 692         while (true) {
 693                 optional<DCPTime> t = _butler->get_audio (reinterpret_cast<float*> (out_p), frames);
 694                 if (!t || DCPTime(uncorrected_time() - *t) < one_video_frame()) {
 695                         /* There was an underrun or this audio is on time; carry on */
 696                         break;
 697                 }
 698                 /* The audio we just got was (very) late; drop it and get some more. */
 699         }
 700
 701         boost::mutex::scoped_lock lm (_latency_history_mutex, boost::try_to_lock);
 702         if (lm) {
 703                 _latency_history.push_back (_audio.getStreamLatency ());
 704                 if (_latency_history.size() > static_cast<size_t> (_latency_history_count)) {
 705                         _latency_history.pop_front ();
 706                 }
 707         }
 708
 709         return 0;
 710 }
 711
 712 Frame
 713 FilmViewer::average_latency () const
 714 {
 715         boost::mutex::scoped_lock lm (_latency_history_mutex);
 716         if (_latency_history.empty()) {
 717                 return 0;
 718         }
 719
 720         Frame total = 0;
 721         BOOST_FOREACH (Frame i, _latency_history) {
 722                 total += i;
 723         }
 724
 725         return total / _latency_history.size();
 726 }
 727
 728 void
 729 FilmViewer::set_dcp_decode_reduction (optional<int> reduction)
 730 {
 731         _dcp_decode_reduction = reduction;
 732         if (_player) {
 733                 _player->set_dcp_decode_reduction (reduction);
 734         }
 735 }
 736
 737 optional<int>
 738 FilmViewer::dcp_decode_reduction () const
 739 {
 740         return _dcp_decode_reduction;
 741 }
 742
 743 DCPTime
 744 FilmViewer::one_video_frame () const
 745 {
 746         return DCPTime::from_frames (1, _film->video_frame_rate());
 747 }
 748
 749 /** Open a dialog box showing our film's closed captions */
 750 void
 751 FilmViewer::show_closed_captions ()
 752 {
 753         _closed_captions_dialog->Show();
 754 }
 755
 756 void
 757 FilmViewer::seek_by (DCPTime by, bool accurate)
 758 {
 759         seek (_video_position + by, accurate);
 760 }
 761
 762 void
 763 FilmViewer::set_pad_black (bool p)
 764 {
 765         _pad_black = p;
 766 }