src/wx/film_viewer.cc

   1 /*
   2     Copyright (C) 2012-2021 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
  22 /** @file  src/film_viewer.cc
  23  *  @brief A wx widget to view a preview of a Film.
  24  */
  25
  26
  27 #include "closed_captions_dialog.h"
  28 #include "film_viewer.h"
  29 #include "gl_video_view.h"
  30 #include "nag_dialog.h"
  31 #include "playhead_to_frame_dialog.h"
  32 #include "playhead_to_timecode_dialog.h"
  33 #include "simple_video_view.h"
  34 #include "wx_util.h"
  35 #include "lib/butler.h"
  36 #include "lib/compose.hpp"
  37 #include "lib/config.h"
  38 #include "lib/dcpomatic_log.h"
  39 #include "lib/examine_content_job.h"
  40 #include "lib/exceptions.h"
  41 #include "lib/film.h"
  42 #include "lib/filter.h"
  43 #include "lib/image.h"
  44 #include "lib/job_manager.h"
  45 #include "lib/log.h"
  46 #include "lib/player.h"
  47 #include "lib/player_video.h"
  48 #include "lib/ratio.h"
  49 #include "lib/text_content.h"
  50 #include "lib/timer.h"
  51 #include "lib/util.h"
  52 #include "lib/video_content.h"
  53 #include "lib/video_decoder.h"
  54 #include <dcp/exceptions.h>
  55 #include <dcp/warnings.h>
  56 extern "C" {
  57 #include <libavutil/pixfmt.h>
  58 }
  59 LIBDCP_DISABLE_WARNINGS
  60 #include <wx/tglbtn.h>
  61 LIBDCP_ENABLE_WARNINGS
  62 #include <iomanip>
  63
  64
  65 using std::bad_alloc;
  66 using std::dynamic_pointer_cast;
  67 using std::make_shared;
  68 using std::max;
  69 using std::shared_ptr;
  70 using std::string;
  71 using std::vector;
  72 using boost::optional;
  73 #if BOOST_VERSION >= 106100
  74 using namespace boost::placeholders;
  75 #endif
  76 using dcp::Size;
  77 using namespace dcpomatic;
  78
  79
  80 static
  81 int
  82 rtaudio_callback (void* out, void *, unsigned int frames, double, RtAudioStreamStatus, void* data)
  83 {
  84         return reinterpret_cast<FilmViewer*>(data)->audio_callback (out, frames);
  85 }
  86
  87
  88 FilmViewer::FilmViewer (wxWindow* p)
  89         : _audio (DCPOMATIC_RTAUDIO_API)
  90         , _closed_captions_dialog (new ClosedCaptionsDialog(p, this))
  91 {
  92 #if wxCHECK_VERSION(3, 1, 0)
  93         switch (Config::instance()->video_view_type()) {
  94         case Config::VIDEO_VIEW_OPENGL:
  95                 _video_view = std::make_shared<GLVideoView>(this, p);
  96                 break;
  97         case Config::VIDEO_VIEW_SIMPLE:
  98                 _video_view = std::make_shared<SimpleVideoView>(this, p);
  99                 break;
 100         }
 101 #else
 102         _video_view = std::make_shared<SimpleVideoView>(this, p);
 103 #endif
 104
 105         _video_view->Sized.connect (boost::bind(&FilmViewer::video_view_sized, this));
 106         _video_view->TooManyDropped.connect (boost::bind(boost::ref(TooManyDropped)));
 107
 108         set_film (shared_ptr<Film>());
 109
 110         _config_changed_connection = Config::instance()->Changed.connect(bind(&FilmViewer::config_changed, this, _1));
 111         config_changed (Config::SOUND_OUTPUT);
 112 }
 113
 114
 115 FilmViewer::~FilmViewer ()
 116 {
 117         stop ();
 118 }
 119
 120
 121 /** Ask for ::idle_handler() to be called next time we are idle */
 122 void
 123 FilmViewer::request_idle_display_next_frame ()
 124 {
 125         if (_idle_get) {
 126                 return;
 127         }
 128
 129         _idle_get = true;
 130         DCPOMATIC_ASSERT (signal_manager);
 131         signal_manager->when_idle (boost::bind(&FilmViewer::idle_handler, this));
 132 }
 133
 134
 135 void
 136 FilmViewer::idle_handler ()
 137 {
 138         if (!_idle_get) {
 139                 return;
 140         }
 141
 142         if (_video_view->display_next_frame(true) == VideoView::AGAIN) {
 143                 /* get() could not complete quickly so we'll try again later */
 144                 signal_manager->when_idle (boost::bind(&FilmViewer::idle_handler, this));
 145         } else {
 146                 _idle_get = false;
 147         }
 148 }
 149
 150
 151 void
 152 FilmViewer::set_film (shared_ptr<Film> film)
 153 {
 154         if (_film == film) {
 155                 return;
 156         }
 157
 158         _film = film;
 159
 160         _video_view->clear ();
 161         _closed_captions_dialog->clear ();
 162
 163         if (!_film) {
 164                 _player.reset ();
 165                 recreate_butler ();
 166                 _video_view->update ();
 167                 return;
 168         }
 169
 170         try {
 171                 _player = make_shared<Player>(_film, _optimise_for_j2k ? Image::Alignment::COMPACT : Image::Alignment::PADDED);
 172                 _player->set_fast ();
 173                 if (_dcp_decode_reduction) {
 174                         _player->set_dcp_decode_reduction (_dcp_decode_reduction);
 175                 }
 176         } catch (bad_alloc &) {
 177                 error_dialog (_video_view->get(), _("There is not enough free memory to do that."));
 178                 _film.reset ();
 179                 return;
 180         }
 181
 182         _player->set_always_burn_open_subtitles ();
 183         _player->set_play_referenced ();
 184
 185         _film->Change.connect (boost::bind (&FilmViewer::film_change, this, _1, _2));
 186         _film->LengthChange.connect (boost::bind(&FilmViewer::film_length_change, this));
 187         _player->Change.connect (boost::bind (&FilmViewer::player_change, this, _1, _2, _3));
 188
 189         film_change (ChangeType::DONE, Film::Property::VIDEO_FRAME_RATE);
 190         film_change (ChangeType::DONE, Film::Property::THREE_D);
 191         film_length_change ();
 192
 193         /* Keep about 1 second's worth of history samples */
 194         _latency_history_count = _film->audio_frame_rate() / _audio_block_size;
 195
 196         _closed_captions_dialog->update_tracks (_film);
 197
 198         recreate_butler ();
 199
 200         calculate_sizes ();
 201         slow_refresh ();
 202 }
 203
 204
 205 void
 206 FilmViewer::recreate_butler ()
 207 {
 208         suspend ();
 209         _butler.reset ();
 210
 211         if (!_film) {
 212                 resume ();
 213                 return;
 214         }
 215
 216 #if wxCHECK_VERSION(3, 1, 0)
 217         auto const j2k_gl_optimised = dynamic_pointer_cast<GLVideoView>(_video_view) && _optimise_for_j2k;
 218 #else
 219         auto const j2k_gl_optimised = false;
 220 #endif
 221
 222         _butler = std::make_shared<Butler>(
 223                 _film,
 224                 _player,
 225                 Config::instance()->audio_mapping(_audio_channels),
 226                 _audio_channels,
 227                 boost::bind(&PlayerVideo::force, AV_PIX_FMT_RGB24),
 228                 VideoRange::FULL,
 229                 j2k_gl_optimised ? Image::Alignment::COMPACT : Image::Alignment::PADDED,
 230                 true,
 231                 j2k_gl_optimised,
 232                 (Config::instance()->sound() && _audio.isStreamOpen()) ? Butler::Audio::ENABLED : Butler::Audio::DISABLED
 233                 );
 234
 235         _closed_captions_dialog->set_butler (_butler);
 236
 237         resume ();
 238 }
 239
 240
 241 void
 242 FilmViewer::set_outline_content (bool o)
 243 {
 244         _outline_content = o;
 245         _video_view->update ();
 246 }
 247
 248
 249 void
 250 FilmViewer::set_outline_subtitles (optional<dcpomatic::Rect<double>> rect)
 251 {
 252         _outline_subtitles = rect;
 253         _video_view->update ();
 254 }
 255
 256
 257 void
 258 FilmViewer::set_eyes (Eyes e)
 259 {
 260         _video_view->set_eyes (e);
 261         slow_refresh ();
 262 }
 263
 264
 265 void
 266 FilmViewer::video_view_sized ()
 267 {
 268         calculate_sizes ();
 269         if (!quick_refresh()) {
 270                 slow_refresh ();
 271         }
 272 }
 273
 274
 275 void
 276 FilmViewer::calculate_sizes ()
 277 {
 278         if (!_film || !_player) {
 279                 return;
 280         }
 281
 282         auto const container = _film->container ();
 283
 284         auto const scale = dpi_scale_factor (_video_view->get());
 285         int const video_view_width = std::round(_video_view->get()->GetSize().x * scale);
 286         int const video_view_height = std::round(_video_view->get()->GetSize().y * scale);
 287
 288         auto const view_ratio = float(video_view_width) / video_view_height;
 289         auto const film_ratio = container ? container->ratio () : 1.78;
 290
 291         dcp::Size out_size;
 292         if (view_ratio < film_ratio) {
 293                 /* panel is less widscreen than the film; clamp width */
 294                 out_size.width = video_view_width;
 295                 out_size.height = lrintf (out_size.width / film_ratio);
 296         } else {
 297                 /* panel is more widescreen than the film; clamp height */
 298                 out_size.height = video_view_height;
 299                 out_size.width = lrintf (out_size.height * film_ratio);
 300         }
 301
 302         /* Catch silly values */
 303         out_size.width = max (64, out_size.width);
 304         out_size.height = max (64, out_size.height);
 305
 306         /* Make sure the video container sizes are always a multiple of 2 so that
 307          * we don't get gaps with subsampled sources (e.g. YUV420)
 308          */
 309         if (out_size.width % 2) {
 310                 out_size.width++;
 311         }
 312         if (out_size.height % 2) {
 313                 out_size.height++;
 314         }
 315
 316         _player->set_video_container_size (out_size);
 317 }
 318
 319
 320 void
 321 FilmViewer::suspend ()
 322 {
 323         ++_suspended;
 324         if (_audio.isStreamRunning()) {
 325                 _audio.abortStream();
 326         }
 327 }
 328
 329
 330 void
 331 FilmViewer::start_audio_stream_if_open ()
 332 {
 333         if (_audio.isStreamOpen()) {
 334                 _audio.setStreamTime (_video_view->position().seconds());
 335                 try {
 336                         _audio.startStream ();
 337                 } catch (RtAudioError& e) {
 338                         _audio_channels = 0;
 339                         error_dialog (
 340                                 _video_view->get(),
 341                                 _("There was a problem starting audio playback.  Please try another audio output device in Preferences."), std_to_wx(e.what())
 342                                 );
 343                 }
 344         }
 345 }
 346
 347
 348 void
 349 FilmViewer::resume ()
 350 {
 351         DCPOMATIC_ASSERT (_suspended > 0);
 352         --_suspended;
 353         if (_playing && !_suspended) {
 354                 start_audio_stream_if_open ();
 355                 _video_view->start ();
 356         }
 357 }
 358
 359
 360 void
 361 FilmViewer::start ()
 362 {
 363         if (!_film) {
 364                 return;
 365         }
 366
 367         auto v = PlaybackPermitted ();
 368         if (v && !*v) {
 369                 /* Computer says no */
 370                 return;
 371         }
 372
 373         /* We are about to set up the audio stream from the position of the video view.
 374            If there is `lazy' seek in progress we need to wait for it to go through so that
 375            _video_view->position() gives us a sensible answer.
 376          */
 377         while (_idle_get) {
 378                 idle_handler ();
 379         }
 380
 381         /* Take the video view's idea of position as our `playhead' and start the
 382            audio stream (which is the timing reference) there.
 383          */
 384         start_audio_stream_if_open ();
 385
 386         _playing = true;
 387         /* Calling start() below may directly result in Stopped being emitted, and if that
 388          * happens we want it to come after the Started signal, so do that first.
 389          */
 390         Started ();
 391         _video_view->start ();
 392 }
 393
 394
 395 bool
 396 FilmViewer::stop ()
 397 {
 398         if (_audio.isStreamRunning()) {
 399                 /* stop stream and discard any remaining queued samples */
 400                 _audio.abortStream ();
 401         }
 402
 403         if (!_playing) {
 404                 return false;
 405         }
 406
 407         _playing = false;
 408         _video_view->stop ();
 409         Stopped ();
 410
 411         _video_view->rethrow ();
 412         return true;
 413 }
 414
 415
 416 void
 417 FilmViewer::player_change (ChangeType type, int property, bool frequent)
 418 {
 419         if (type != ChangeType::DONE || frequent) {
 420                 return;
 421         }
 422
 423         if (_coalesce_player_changes) {
 424                 _pending_player_changes.push_back (property);
 425                 return;
 426         }
 427
 428         player_change ({property});
 429 }
 430
 431
 432 void
 433 FilmViewer::player_change (vector<int> properties)
 434 {
 435         calculate_sizes ();
 436
 437         bool try_quick_refresh = false;
 438         bool update_ccap_tracks = false;
 439
 440         for (auto i: properties) {
 441                 if (
 442                         i == VideoContentProperty::CROP ||
 443                         i == VideoContentProperty::CUSTOM_RATIO ||
 444                         i == VideoContentProperty::CUSTOM_SIZE ||
 445                         i == VideoContentProperty::FADE_IN ||
 446                         i == VideoContentProperty::FADE_OUT ||
 447                         i == VideoContentProperty::COLOUR_CONVERSION ||
 448                         i == PlayerProperty::VIDEO_CONTAINER_SIZE ||
 449                         i == PlayerProperty::FILM_CONTAINER
 450                    ) {
 451                         try_quick_refresh = true;
 452                 }
 453
 454                 if (i == TextContentProperty::USE || i == TextContentProperty::TYPE || i == TextContentProperty::DCP_TRACK) {
 455                         update_ccap_tracks = true;
 456                 }
 457         }
 458
 459         if (!try_quick_refresh || !quick_refresh()) {
 460                 slow_refresh ();
 461         }
 462
 463         if (update_ccap_tracks) {
 464                 _closed_captions_dialog->update_tracks (_film);
 465         }
 466 }
 467
 468
 469 void
 470 FilmViewer::film_change (ChangeType type, Film::Property p)
 471 {
 472         if (type != ChangeType::DONE) {
 473                 return;
 474         }
 475
 476         if (p == Film::Property::AUDIO_CHANNELS) {
 477                 recreate_butler ();
 478         } else if (p == Film::Property::VIDEO_FRAME_RATE) {
 479                 _video_view->set_video_frame_rate (_film->video_frame_rate());
 480         } else if (p == Film::Property::THREE_D) {
 481                 _video_view->set_three_d (_film->three_d());
 482         } else if (p == Film::Property::CONTENT) {
 483                 _closed_captions_dialog->update_tracks (_film);
 484         }
 485 }
 486
 487
 488 void
 489 FilmViewer::film_length_change ()
 490 {
 491         _video_view->set_length (_film->length());
 492 }
 493
 494
 495 /** Re-get the current frame slowly by seeking */
 496 void
 497 FilmViewer::slow_refresh ()
 498 {
 499         seek (_video_view->position(), true);
 500 }
 501
 502
 503 /** Try to re-get the current frame quickly by resetting the metadata
 504  *  in the PlayerVideo that we used last time.
 505  *  @return true if this was possible, false if not.
 506  */
 507 bool
 508 FilmViewer::quick_refresh ()
 509 {
 510         if (!_video_view || !_film || !_player) {
 511                 return true;
 512         }
 513         return _video_view->reset_metadata (_film, _player->video_container_size());
 514 }
 515
 516
 517 void
 518 FilmViewer::seek (shared_ptr<Content> content, ContentTime t, bool accurate)
 519 {
 520         auto dt = _player->content_time_to_dcp (content, t);
 521         if (dt) {
 522                 seek (*dt, accurate);
 523         }
 524 }
 525
 526
 527 void
 528 FilmViewer::set_coalesce_player_changes (bool c)
 529 {
 530         _coalesce_player_changes = c;
 531
 532         if (!c) {
 533                 player_change (_pending_player_changes);
 534                 _pending_player_changes.clear ();
 535         }
 536 }
 537
 538
 539 void
 540 FilmViewer::seek (DCPTime t, bool accurate)
 541 {
 542         if (!_butler) {
 543                 return;
 544         }
 545
 546         if (t < DCPTime()) {
 547                 t = DCPTime ();
 548         }
 549
 550         if (t >= _film->length()) {
 551                 t = _film->length() - one_video_frame();
 552         }
 553
 554         suspend ();
 555
 556         _closed_captions_dialog->clear ();
 557         _butler->seek (t, accurate);
 558
 559         if (!_playing) {
 560                 /* We're not playing, so let the GUI thread get on and
 561                    come back later to get the next frame after the seek.
 562                 */
 563                 request_idle_display_next_frame ();
 564         } else {
 565                 /* We're going to start playing again straight away
 566                    so wait for the seek to finish.
 567                 */
 568                 while (_video_view->display_next_frame(false) == VideoView::AGAIN) {}
 569         }
 570
 571         resume ();
 572 }
 573
 574
 575 void
 576 FilmViewer::config_changed (Config::Property p)
 577 {
 578         if (p == Config::AUDIO_MAPPING) {
 579                 recreate_butler ();
 580                 return;
 581         }
 582
 583         if (p != Config::SOUND && p != Config::SOUND_OUTPUT) {
 584                 return;
 585         }
 586
 587         if (_audio.isStreamOpen ()) {
 588                 _audio.closeStream ();
 589         }
 590
 591         if (Config::instance()->sound() && _audio.getDeviceCount() > 0) {
 592                 unsigned int st = 0;
 593                 if (Config::instance()->sound_output()) {
 594                         while (st < _audio.getDeviceCount()) {
 595                                 try {
 596                                         if (_audio.getDeviceInfo(st).name == Config::instance()->sound_output().get()) {
 597                                                 break;
 598                                         }
 599                                 } catch (RtAudioError&) {
 600                                         /* Something went wrong with that device so we don't want to use it anyway */
 601                                 }
 602                                 ++st;
 603                         }
 604                         if (st == _audio.getDeviceCount()) {
 605                                 st = _audio.getDefaultOutputDevice();
 606                         }
 607                 } else {
 608                         st = _audio.getDefaultOutputDevice();
 609                 }
 610
 611                 try {
 612                         _audio_channels = _audio.getDeviceInfo(st).outputChannels;
 613                         RtAudio::StreamParameters sp;
 614                         sp.deviceId = st;
 615                         sp.nChannels = _audio_channels;
 616                         sp.firstChannel = 0;
 617                         _audio.openStream (&sp, 0, RTAUDIO_FLOAT32, 48000, &_audio_block_size, &rtaudio_callback, this);
 618                 } catch (RtAudioError& e) {
 619                         _audio_channels = 0;
 620                         error_dialog (
 621                                 _video_view->get(),
 622                                 _("Could not set up audio output.  There will be no audio during the preview."), std_to_wx(e.what())
 623                                 );
 624                 }
 625                 recreate_butler ();
 626
 627         } else {
 628                 _audio_channels = 0;
 629                 recreate_butler ();
 630         }
 631 }
 632
 633
 634 DCPTime
 635 FilmViewer::uncorrected_time () const
 636 {
 637         if (_audio.isStreamRunning()) {
 638                 return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime());
 639         }
 640
 641         return _video_view->position();
 642 }
 643
 644
 645 optional<DCPTime>
 646 FilmViewer::audio_time () const
 647 {
 648         if (!_audio.isStreamRunning()) {
 649                 return {};
 650         }
 651
 652         return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime ()) -
 653                 DCPTime::from_frames (average_latency(), _film->audio_frame_rate());
 654 }
 655
 656
 657 DCPTime
 658 FilmViewer::time () const
 659 {
 660         return audio_time().get_value_or(_video_view->position());
 661 }
 662
 663
 664 int
 665 FilmViewer::audio_callback (void* out_p, unsigned int frames)
 666 {
 667         while (true) {
 668                 auto t = _butler->get_audio (Butler::Behaviour::NON_BLOCKING, reinterpret_cast<float*> (out_p), frames);
 669                 if (!t || DCPTime(uncorrected_time() - *t) < one_video_frame()) {
 670                         /* There was an underrun or this audio is on time; carry on */
 671                         break;
 672                 }
 673                 /* The audio we just got was (very) late; drop it and get some more. */
 674         }
 675
 676         boost::mutex::scoped_lock lm (_latency_history_mutex, boost::try_to_lock);
 677         if (lm) {
 678                 _latency_history.push_back (_audio.getStreamLatency ());
 679                 if (_latency_history.size() > static_cast<size_t> (_latency_history_count)) {
 680                         _latency_history.pop_front ();
 681                 }
 682         }
 683
 684         return 0;
 685 }
 686
 687
 688 Frame
 689 FilmViewer::average_latency () const
 690 {
 691         boost::mutex::scoped_lock lm (_latency_history_mutex);
 692         if (_latency_history.empty()) {
 693                 return 0;
 694         }
 695
 696         Frame total = 0;
 697         for (auto i: _latency_history) {
 698                 total += i;
 699         }
 700
 701         return total / _latency_history.size();
 702 }
 703
 704
 705 void
 706 FilmViewer::set_dcp_decode_reduction (optional<int> reduction)
 707 {
 708         _dcp_decode_reduction = reduction;
 709         if (_player) {
 710                 _player->set_dcp_decode_reduction (reduction);
 711         }
 712 }
 713
 714
 715 optional<int>
 716 FilmViewer::dcp_decode_reduction () const
 717 {
 718         return _dcp_decode_reduction;
 719 }
 720
 721
 722 optional<ContentTime>
 723 FilmViewer::position_in_content (shared_ptr<const Content> content) const
 724 {
 725         return _player->dcp_to_content_time (content, position());
 726 }
 727
 728
 729 DCPTime
 730 FilmViewer::one_video_frame () const
 731 {
 732         return DCPTime::from_frames (1, _film ? _film->video_frame_rate() : 24);
 733 }
 734
 735
 736 /** Open a dialog box showing our film's closed captions */
 737 void
 738 FilmViewer::show_closed_captions ()
 739 {
 740         _closed_captions_dialog->Show();
 741 }
 742
 743
 744 void
 745 FilmViewer::seek_by (DCPTime by, bool accurate)
 746 {
 747         seek (_video_view->position() + by, accurate);
 748 }
 749
 750
 751 void
 752 FilmViewer::set_pad_black (bool p)
 753 {
 754         _pad_black = p;
 755 }
 756
 757
 758 /** Called when a player has finished the current film.
 759  *  May be called from a non-UI thread.
 760  */
 761 void
 762 FilmViewer::finished ()
 763 {
 764         emit (boost::bind(&FilmViewer::ui_finished, this));
 765 }
 766
 767
 768 /** Called by finished() in the UI thread */
 769 void
 770 FilmViewer::ui_finished ()
 771 {
 772         stop ();
 773         Finished ();
 774 }
 775
 776
 777 int
 778 FilmViewer::dropped () const
 779 {
 780         return _video_view->dropped ();
 781 }
 782
 783
 784 int
 785 FilmViewer::errored () const
 786 {
 787         return _video_view->errored ();
 788 }
 789
 790
 791 int
 792 FilmViewer::gets () const
 793 {
 794         return _video_view->gets ();
 795 }
 796
 797
 798 void
 799 FilmViewer::image_changed (shared_ptr<PlayerVideo> pv)
 800 {
 801         emit (boost::bind(boost::ref(ImageChanged), pv));
 802 }
 803
 804
 805 void
 806 FilmViewer::set_optimise_for_j2k (bool o)
 807 {
 808         _optimise_for_j2k = o;
 809         _video_view->set_optimise_for_j2k (o);
 810 }
 811
 812
 813 void
 814 FilmViewer::set_crop_guess (dcpomatic::Rect<float> crop)
 815 {
 816         if (crop != _crop_guess) {
 817                 _crop_guess = crop;
 818                 _video_view->update ();
 819         }
 820 }
 821
 822
 823 void
 824 FilmViewer::unset_crop_guess ()
 825 {
 826         _crop_guess = boost::none;
 827         _video_view->update ();
 828 }
 829