src/lib/ffmpeg_content.cc

   1 /*
   2     Copyright (C) 2013-2016 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 #include "ffmpeg_content.h"
  22 #include "video_content.h"
  23 #include "audio_content.h"
  24 #include "ffmpeg_examiner.h"
  25 #include "ffmpeg_subtitle_stream.h"
  26 #include "ffmpeg_audio_stream.h"
  27 #include "compose.hpp"
  28 #include "job.h"
  29 #include "util.h"
  30 #include "filter.h"
  31 #include "film.h"
  32 #include "log.h"
  33 #include "exceptions.h"
  34 #include "frame_rate_change.h"
  35 #include "subtitle_content.h"
  36 #include <dcp/raw_convert.h>
  37 #include <libcxml/cxml.h>
  38 extern "C" {
  39 #include <libavformat/avformat.h>
  40 #include <libavutil/pixdesc.h>
  41 }
  42 #include <libxml++/libxml++.h>
  43 #include <boost/foreach.hpp>
  44 #include <iostream>
  45
  46 #include "i18n.h"
  47
  48 #define LOG_GENERAL(...) film->log()->log (String::compose (__VA_ARGS__), LogEntry::TYPE_GENERAL);
  49
  50 using std::string;
  51 using std::vector;
  52 using std::list;
  53 using std::cout;
  54 using std::pair;
  55 using std::make_pair;
  56 using std::max;
  57 using boost::shared_ptr;
  58 using boost::dynamic_pointer_cast;
  59 using boost::optional;
  60 using dcp::raw_convert;
  61
  62 int const FFmpegContentProperty::SUBTITLE_STREAMS = 100;
  63 int const FFmpegContentProperty::SUBTITLE_STREAM = 101;
  64 int const FFmpegContentProperty::FILTERS = 102;
  65
  66 FFmpegContent::FFmpegContent (shared_ptr<const Film> film, boost::filesystem::path p)
  67         : Content (film, p)
  68 {
  69
  70 }
  71
  72 FFmpegContent::FFmpegContent (shared_ptr<const Film> film, cxml::ConstNodePtr node, int version, list<string>& notes)
  73         : Content (film, node)
  74 {
  75         video = VideoContent::from_xml (this, node, version);
  76         audio = AudioContent::from_xml (this, node, version);
  77         subtitle = SubtitleContent::from_xml (this, node, version);
  78
  79         list<cxml::NodePtr> c = node->node_children ("SubtitleStream");
  80         for (list<cxml::NodePtr>::const_iterator i = c.begin(); i != c.end(); ++i) {
  81                 _subtitle_streams.push_back (shared_ptr<FFmpegSubtitleStream> (new FFmpegSubtitleStream (*i, version)));
  82                 if ((*i)->optional_number_child<int> ("Selected")) {
  83                         _subtitle_stream = _subtitle_streams.back ();
  84                 }
  85         }
  86
  87         c = node->node_children ("AudioStream");
  88         for (list<cxml::NodePtr>::const_iterator i = c.begin(); i != c.end(); ++i) {
  89                 shared_ptr<FFmpegAudioStream> as (new FFmpegAudioStream (*i, version));
  90                 audio->add_stream (as);
  91                 if (version < 11 && !(*i)->optional_node_child ("Selected")) {
  92                         /* This is an old file and this stream is not selected, so un-map it */
  93                         as->set_mapping (AudioMapping (as->channels (), MAX_DCP_AUDIO_CHANNELS));
  94                 }
  95         }
  96
  97         c = node->node_children ("Filter");
  98         for (list<cxml::NodePtr>::iterator i = c.begin(); i != c.end(); ++i) {
  99                 Filter const * f = Filter::from_id ((*i)->content ());
 100                 if (f) {
 101                         _filters.push_back (f);
 102                 } else {
 103                         notes.push_back (String::compose (_("DCP-o-matic no longer supports the `%1' filter, so it has been turned off."), (*i)->content()));
 104                 }
 105         }
 106
 107         optional<ContentTime::Type> const f = node->optional_number_child<ContentTime::Type> ("FirstVideo");
 108         if (f) {
 109                 _first_video = ContentTime (f.get ());
 110         }
 111
 112         _color_range = static_cast<AVColorRange> (node->optional_number_child<int>("ColorRange").get_value_or (AVCOL_RANGE_UNSPECIFIED));
 113         _color_primaries = static_cast<AVColorPrimaries> (node->optional_number_child<int>("ColorPrimaries").get_value_or (AVCOL_PRI_UNSPECIFIED));
 114         _color_trc = static_cast<AVColorTransferCharacteristic> (
 115                 node->optional_number_child<int>("ColorTransferCharacteristic").get_value_or (AVCOL_TRC_UNSPECIFIED)
 116                 );
 117         _colorspace = static_cast<AVColorSpace> (node->optional_number_child<int>("Colorspace").get_value_or (AVCOL_SPC_UNSPECIFIED));
 118         _bits_per_pixel = node->optional_number_child<int> ("BitsPerPixel");
 119
 120 }
 121
 122 FFmpegContent::FFmpegContent (shared_ptr<const Film> film, vector<shared_ptr<Content> > c)
 123         : Content (film, c)
 124 {
 125         vector<shared_ptr<Content> >::const_iterator i = c.begin ();
 126
 127         bool need_video = false;
 128         bool need_audio = false;
 129         bool need_subtitle = false;
 130
 131         if (i != c.end ()) {
 132                 need_video = static_cast<bool> ((*i)->video);
 133                 need_audio = static_cast<bool> ((*i)->audio);
 134                 need_subtitle = static_cast<bool> ((*i)->subtitle);
 135         }
 136
 137         while (i != c.end ()) {
 138                 if (need_video != static_cast<bool> ((*i)->video)) {
 139                         throw JoinError (_("Content to be joined must all have or not have video"));
 140                 }
 141                 if (need_audio != static_cast<bool> ((*i)->audio)) {
 142                         throw JoinError (_("Content to be joined must all have or not have audio"));
 143                 }
 144                 if (need_subtitle != static_cast<bool> ((*i)->subtitle)) {
 145                         throw JoinError (_("Content to be joined must all have or not have subtitles"));
 146                 }
 147                 ++i;
 148         }
 149
 150         if (need_video) {
 151                 video.reset (new VideoContent (this, c));
 152         }
 153         if (need_audio) {
 154                 audio.reset (new AudioContent (this, c));
 155         }
 156         if (need_subtitle) {
 157                 subtitle.reset (new SubtitleContent (this, c));
 158         }
 159
 160         shared_ptr<FFmpegContent> ref = dynamic_pointer_cast<FFmpegContent> (c[0]);
 161         DCPOMATIC_ASSERT (ref);
 162
 163         for (size_t i = 0; i < c.size(); ++i) {
 164                 shared_ptr<FFmpegContent> fc = dynamic_pointer_cast<FFmpegContent> (c[i]);
 165                 if (fc->subtitle && fc->subtitle->use() && *(fc->_subtitle_stream.get()) != *(ref->_subtitle_stream.get())) {
 166                         throw JoinError (_("Content to be joined must use the same subtitle stream."));
 167                 }
 168         }
 169
 170         /* XXX: should probably check that more of the stuff below is the same in *this and ref */
 171
 172         _subtitle_streams = ref->subtitle_streams ();
 173         _subtitle_stream = ref->subtitle_stream ();
 174         _first_video = ref->_first_video;
 175         _filters = ref->_filters;
 176         _color_range = ref->_color_range;
 177         _color_primaries = ref->_color_primaries;
 178         _color_trc = ref->_color_trc;
 179         _colorspace = ref->_colorspace;
 180         _bits_per_pixel = ref->_bits_per_pixel;
 181 }
 182
 183 void
 184 FFmpegContent::as_xml (xmlpp::Node* node, bool with_paths) const
 185 {
 186         node->add_child("Type")->add_child_text ("FFmpeg");
 187         Content::as_xml (node, with_paths);
 188
 189         if (video) {
 190                 video->as_xml (node);
 191         }
 192
 193         if (audio) {
 194                 audio->as_xml (node);
 195
 196                 BOOST_FOREACH (AudioStreamPtr i, audio->streams ()) {
 197                         shared_ptr<FFmpegAudioStream> f = dynamic_pointer_cast<FFmpegAudioStream> (i);
 198                         DCPOMATIC_ASSERT (f);
 199                         f->as_xml (node->add_child("AudioStream"));
 200                 }
 201         }
 202
 203         if (subtitle) {
 204                 subtitle->as_xml (node);
 205         }
 206
 207         boost::mutex::scoped_lock lm (_mutex);
 208
 209         for (vector<shared_ptr<FFmpegSubtitleStream> >::const_iterator i = _subtitle_streams.begin(); i != _subtitle_streams.end(); ++i) {
 210                 xmlpp::Node* t = node->add_child("SubtitleStream");
 211                 if (_subtitle_stream && *i == _subtitle_stream) {
 212                         t->add_child("Selected")->add_child_text("1");
 213                 }
 214                 (*i)->as_xml (t);
 215         }
 216
 217         for (vector<Filter const *>::const_iterator i = _filters.begin(); i != _filters.end(); ++i) {
 218                 node->add_child("Filter")->add_child_text ((*i)->id ());
 219         }
 220
 221         if (_first_video) {
 222                 node->add_child("FirstVideo")->add_child_text (raw_convert<string> (_first_video.get().get()));
 223         }
 224
 225         node->add_child("ColorRange")->add_child_text (raw_convert<string> (static_cast<int> (_color_range)));
 226         node->add_child("ColorPrimaries")->add_child_text (raw_convert<string> (static_cast<int> (_color_primaries)));
 227         node->add_child("ColorTransferCharacteristic")->add_child_text (raw_convert<string> (static_cast<int> (_color_trc)));
 228         node->add_child("Colorspace")->add_child_text (raw_convert<string> (static_cast<int> (_colorspace)));
 229         if (_bits_per_pixel) {
 230                 node->add_child("BitsPerPixel")->add_child_text (raw_convert<string> (_bits_per_pixel.get ()));
 231         }
 232 }
 233
 234 void
 235 FFmpegContent::examine (shared_ptr<Job> job)
 236 {
 237         job->set_progress_unknown ();
 238
 239         Content::examine (job);
 240
 241         shared_ptr<FFmpegExaminer> examiner (new FFmpegExaminer (shared_from_this (), job));
 242
 243         if (examiner->has_video ()) {
 244                 video.reset (new VideoContent (this));
 245                 video->take_from_examiner (examiner);
 246         }
 247
 248         boost::filesystem::path first_path = path (0);
 249
 250         {
 251                 boost::mutex::scoped_lock lm (_mutex);
 252
 253                 if (examiner->has_video ()) {
 254                         _first_video = examiner->first_video ();
 255                         _color_range = examiner->color_range ();
 256                         _color_primaries = examiner->color_primaries ();
 257                         _color_trc = examiner->color_trc ();
 258                         _colorspace = examiner->colorspace ();
 259                         _bits_per_pixel = examiner->bits_per_pixel ();
 260                 }
 261
 262                 if (!examiner->audio_streams().empty ()) {
 263                         audio.reset (new AudioContent (this));
 264
 265                         BOOST_FOREACH (shared_ptr<FFmpegAudioStream> i, examiner->audio_streams ()) {
 266                                 audio->add_stream (i);
 267                         }
 268
 269                         AudioStreamPtr as = audio->streams().front();
 270                         AudioMapping m = as->mapping ();
 271                         film()->make_audio_mapping_default (m, first_path);
 272                         as->set_mapping (m);
 273                 }
 274
 275                 _subtitle_streams = examiner->subtitle_streams ();
 276                 if (!_subtitle_streams.empty ()) {
 277                         subtitle.reset (new SubtitleContent (this));
 278                         _subtitle_stream = _subtitle_streams.front ();
 279                 }
 280
 281         }
 282
 283         if (examiner->has_video ()) {
 284                 set_default_colour_conversion ();
 285         }
 286
 287         signal_changed (FFmpegContentProperty::SUBTITLE_STREAMS);
 288         signal_changed (FFmpegContentProperty::SUBTITLE_STREAM);
 289 }
 290
 291 string
 292 FFmpegContent::summary () const
 293 {
 294         if (video && audio) {
 295                 return String::compose (_("%1 [movie]"), path_summary ());
 296         } else if (video) {
 297                 return String::compose (_("%1 [video]"), path_summary ());
 298         } else if (audio) {
 299                 return String::compose (_("%1 [audio]"), path_summary ());
 300         }
 301
 302         return path_summary ();
 303 }
 304
 305 string
 306 FFmpegContent::technical_summary () const
 307 {
 308         string as = "";
 309         BOOST_FOREACH (shared_ptr<FFmpegAudioStream> i, ffmpeg_audio_streams ()) {
 310                 as += i->technical_summary () + " " ;
 311         }
 312
 313         if (as.empty ()) {
 314                 as = "none";
 315         }
 316
 317         string ss = "none";
 318         if (_subtitle_stream) {
 319                 ss = _subtitle_stream->technical_summary ();
 320         }
 321
 322         string filt = Filter::ffmpeg_string (_filters);
 323
 324         string s = Content::technical_summary ();
 325
 326         if (video) {
 327                 s += " - " + video->technical_summary ();
 328         }
 329
 330         if (audio) {
 331                 s += " - " + audio->technical_summary ();
 332         }
 333
 334         return s + String::compose (
 335                 "ffmpeg: audio %1 subtitle %2 filters %3", as, ss, filt
 336                 );
 337 }
 338
 339 void
 340 FFmpegContent::set_subtitle_stream (shared_ptr<FFmpegSubtitleStream> s)
 341 {
 342         {
 343                 boost::mutex::scoped_lock lm (_mutex);
 344                 _subtitle_stream = s;
 345         }
 346
 347         signal_changed (FFmpegContentProperty::SUBTITLE_STREAM);
 348 }
 349
 350 bool
 351 operator== (FFmpegStream const & a, FFmpegStream const & b)
 352 {
 353         return a._id == b._id;
 354 }
 355
 356 bool
 357 operator!= (FFmpegStream const & a, FFmpegStream const & b)
 358 {
 359         return a._id != b._id;
 360 }
 361
 362 DCPTime
 363 FFmpegContent::full_length () const
 364 {
 365         FrameRateChange const frc (active_video_frame_rate (), film()->video_frame_rate ());
 366         if (video) {
 367                 return DCPTime::from_frames (llrint (video->length_after_3d_combine() * frc.factor()), film()->video_frame_rate());
 368         }
 369
 370         DCPOMATIC_ASSERT (audio);
 371
 372         DCPTime longest;
 373         BOOST_FOREACH (AudioStreamPtr i, audio->streams ()) {
 374                 longest = max (longest, DCPTime::from_frames (llrint (i->length() / frc.speed_up), i->frame_rate()));
 375         }
 376
 377         return longest;
 378 }
 379
 380 void
 381 FFmpegContent::set_filters (vector<Filter const *> const & filters)
 382 {
 383         {
 384                 boost::mutex::scoped_lock lm (_mutex);
 385                 _filters = filters;
 386         }
 387
 388         signal_changed (FFmpegContentProperty::FILTERS);
 389 }
 390
 391 string
 392 FFmpegContent::identifier () const
 393 {
 394         string s = Content::identifier();
 395
 396         if (video) {
 397                 s += "_" + video->identifier();
 398         }
 399
 400         if (subtitle && subtitle->use() && subtitle->burn()) {
 401                 s += "_" + subtitle->identifier();
 402         }
 403
 404         boost::mutex::scoped_lock lm (_mutex);
 405
 406         if (_subtitle_stream) {
 407                 s += "_" + _subtitle_stream->identifier ();
 408         }
 409
 410         for (vector<Filter const *>::const_iterator i = _filters.begin(); i != _filters.end(); ++i) {
 411                 s += "_" + (*i)->id ();
 412         }
 413
 414         return s;
 415 }
 416
 417 void
 418 FFmpegContent::set_default_colour_conversion ()
 419 {
 420         DCPOMATIC_ASSERT (video);
 421
 422         dcp::Size const s = video->size ();
 423
 424         boost::mutex::scoped_lock lm (_mutex);
 425
 426         switch (_colorspace) {
 427         case AVCOL_SPC_RGB:
 428                 video->set_colour_conversion (PresetColourConversion::from_id ("srgb").conversion);
 429                 break;
 430         case AVCOL_SPC_BT709:
 431                 video->set_colour_conversion (PresetColourConversion::from_id ("rec709").conversion);
 432                 break;
 433         case AVCOL_SPC_BT470BG:
 434         case AVCOL_SPC_SMPTE170M:
 435         case AVCOL_SPC_SMPTE240M:
 436                 video->set_colour_conversion (PresetColourConversion::from_id ("rec601").conversion);
 437                 break;
 438         case AVCOL_SPC_BT2020_CL:
 439         case AVCOL_SPC_BT2020_NCL:
 440                 video->set_colour_conversion (PresetColourConversion::from_id ("rec2020").conversion);
 441                 break;
 442         default:
 443                 if (s.width < 1080) {
 444                         video->set_colour_conversion (PresetColourConversion::from_id ("rec601").conversion);
 445                 } else {
 446                         video->set_colour_conversion (PresetColourConversion::from_id ("rec709").conversion);
 447                 }
 448                 break;
 449         }
 450 }
 451
 452 void
 453 FFmpegContent::add_properties (list<UserProperty>& p) const
 454 {
 455         Content::add_properties (p);
 456
 457         if (video) {
 458                 video->add_properties (p);
 459
 460                 if (_bits_per_pixel) {
 461                         int const sub = 219 * pow (2, _bits_per_pixel.get() - 8);
 462                         int const total = pow (2, _bits_per_pixel.get());
 463
 464                         switch (_color_range) {
 465                         case AVCOL_RANGE_UNSPECIFIED:
 466                                 /// TRANSLATORS: this means that the range of pixel values used in this
 467                                 /// file is unknown (not specified in the file).
 468                                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour range"), _("Unspecified")));
 469                                 break;
 470                         case AVCOL_RANGE_MPEG:
 471                                 /// TRANSLATORS: this means that the range of pixel values used in this
 472                                 /// file is limited, so that not all possible values are valid.
 473                                 p.push_back (
 474                                         UserProperty (
 475                                                 UserProperty::VIDEO, _("Colour range"), String::compose (_("Limited (%1-%2)"), (total - sub) / 2, (total + sub) / 2)
 476                                                 )
 477                                         );
 478                                 break;
 479                         case AVCOL_RANGE_JPEG:
 480                                 /// TRANSLATORS: this means that the range of pixel values used in this
 481                                 /// file is full, so that all possible pixel values are valid.
 482                                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour range"), String::compose (_("Full (0-%1)"), total)));
 483                                 break;
 484                         default:
 485                                 DCPOMATIC_ASSERT (false);
 486                         }
 487                 } else {
 488                         switch (_color_range) {
 489                         case AVCOL_RANGE_UNSPECIFIED:
 490                                 /// TRANSLATORS: this means that the range of pixel values used in this
 491                                 /// file is unknown (not specified in the file).
 492                                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour range"), _("Unspecified")));
 493                                 break;
 494                         case AVCOL_RANGE_MPEG:
 495                                 /// TRANSLATORS: this means that the range of pixel values used in this
 496                                 /// file is limited, so that not all possible values are valid.
 497                                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour range"), _("Limited")));
 498                                 break;
 499                         case AVCOL_RANGE_JPEG:
 500                                 /// TRANSLATORS: this means that the range of pixel values used in this
 501                                 /// file is full, so that all possible pixel values are valid.
 502                                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour range"), _("Full")));
 503                                 break;
 504                         default:
 505                                 DCPOMATIC_ASSERT (false);
 506                         }
 507                 }
 508
 509                 char const * primaries[] = {
 510                         _("Unspecified"),
 511                         _("BT709"),
 512                         _("Unspecified"),
 513                         _("Unspecified"),
 514                         _("BT470M"),
 515                         _("BT470BG"),
 516                         _("SMPTE 170M (BT601)"),
 517                         _("SMPTE 240M"),
 518                         _("Film"),
 519                         _("BT2020"),
 520                         _("SMPTE ST 428-1 (CIE 1931 XYZ)"),
 521                         _("SMPTE ST 431-2 (2011)"),
 522                         _("SMPTE ST 432-1 D65 (2010)")
 523                 };
 524
 525                 DCPOMATIC_ASSERT (AVCOL_PRI_NB <= 13);
 526                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour primaries"), primaries[_color_primaries]));
 527
 528                 char const * transfers[] = {
 529                         _("Unspecified"),
 530                         _("BT709"),
 531                         _("Unspecified"),
 532                         _("Unspecified"),
 533                         _("Gamma 22 (BT470M)"),
 534                         _("Gamma 28 (BT470BG)"),
 535                         _("SMPTE 170M (BT601)"),
 536                         _("SMPTE 240M"),
 537                         _("Linear"),
 538                         _("Logarithmic (100:1 range)"),
 539                         _("Logarithmic (316:1 range)"),
 540                         _("IEC61966-2-4"),
 541                         _("BT1361 extended colour gamut"),
 542                         _("IEC61966-2-1 (sRGB or sYCC)"),
 543                         _("BT2020 for a 10-bit system"),
 544                         _("BT2020 for a 12-bit system"),
 545                         _("SMPTE ST 2084 for 10, 12, 14 and 16 bit systems"),
 546                         _("SMPTE ST 428-1"),
 547                         _("ARIB STD-B67 ('Hybrid log-gamma')")
 548                 };
 549
 550                 DCPOMATIC_ASSERT (AVCOL_TRC_NB <= 19);
 551                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour transfer characteristic"), transfers[_color_trc]));
 552
 553                 char const * spaces[] = {
 554                         _("RGB / sRGB (IEC61966-2-1)"),
 555                         _("BT709"),
 556                         _("Unspecified"),
 557                         _("Unspecified"),
 558                         _("FCC"),
 559                         _("BT470BG (BT601-6)"),
 560                         _("SMPTE 170M (BT601-6)"),
 561                         _("SMPTE 240M"),
 562                         _("YCOCG"),
 563                         _("BT2020 non-constant luminance"),
 564                         _("BT2020 constant luminance"),
 565                         _("SMPTE 2085, Y'D'zD'x"),
 566                 };
 567
 568                 DCPOMATIC_ASSERT (AVCOL_SPC_NB == 12);
 569                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colourspace"), spaces[_colorspace]));
 570
 571                 if (_bits_per_pixel) {
 572                         p.push_back (UserProperty (UserProperty::VIDEO, _("Bits per pixel"), _bits_per_pixel.get ()));
 573                 }
 574         }
 575
 576         if (audio) {
 577                 audio->add_properties (p);
 578         }
 579 }
 580
 581 /** Our subtitle streams have colour maps, which can be changed, but
 582  *  they have no way of signalling that change.  As a hack, we have this
 583  *  method which callers can use when they've modified one of our subtitle
 584  *  streams.
 585  */
 586 void
 587 FFmpegContent::signal_subtitle_stream_changed ()
 588 {
 589         signal_changed (FFmpegContentProperty::SUBTITLE_STREAM);
 590 }
 591
 592 vector<shared_ptr<FFmpegAudioStream> >
 593 FFmpegContent::ffmpeg_audio_streams () const
 594 {
 595         vector<shared_ptr<FFmpegAudioStream> > fa;
 596
 597         if (audio) {
 598                 BOOST_FOREACH (AudioStreamPtr i, audio->streams()) {
 599                         fa.push_back (dynamic_pointer_cast<FFmpegAudioStream> (i));
 600                 }
 601         }
 602
 603         return fa;
 604 }
 605
 606 void
 607 FFmpegContent::take_settings_from (shared_ptr<const Content> c)
 608 {
 609         Content::take_settings_from (c);
 610
 611         shared_ptr<const FFmpegContent> fc = dynamic_pointer_cast<const FFmpegContent> (c);
 612         _filters = fc->_filters;
 613 }