Rename Subtitle -> Text
[dcpomatic.git] / 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 "text_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 template <class T>
73 optional<T>
74 get_optional_enum (cxml::ConstNodePtr node, string name)
75 {
76         optional<int> const v = node->optional_number_child<int>(name);
77         if (!v) {
78                 return optional<T>();
79         }
80         return static_cast<T>(*v);
81 }
82
83 FFmpegContent::FFmpegContent (shared_ptr<const Film> film, cxml::ConstNodePtr node, int version, list<string>& notes)
84         : Content (film, node)
85 {
86         video = VideoContent::from_xml (this, node, version);
87         audio = AudioContent::from_xml (this, node, version);
88         subtitle = TextContent::from_xml (this, node, version);
89
90         list<cxml::NodePtr> c = node->node_children ("SubtitleStream");
91         for (list<cxml::NodePtr>::const_iterator i = c.begin(); i != c.end(); ++i) {
92                 _subtitle_streams.push_back (shared_ptr<FFmpegSubtitleStream> (new FFmpegSubtitleStream (*i, version)));
93                 if ((*i)->optional_number_child<int> ("Selected")) {
94                         _subtitle_stream = _subtitle_streams.back ();
95                 }
96         }
97
98         c = node->node_children ("AudioStream");
99         for (list<cxml::NodePtr>::const_iterator i = c.begin(); i != c.end(); ++i) {
100                 shared_ptr<FFmpegAudioStream> as (new FFmpegAudioStream (*i, version));
101                 audio->add_stream (as);
102                 if (version < 11 && !(*i)->optional_node_child ("Selected")) {
103                         /* This is an old file and this stream is not selected, so un-map it */
104                         as->set_mapping (AudioMapping (as->channels (), MAX_DCP_AUDIO_CHANNELS));
105                 }
106         }
107
108         c = node->node_children ("Filter");
109         for (list<cxml::NodePtr>::iterator i = c.begin(); i != c.end(); ++i) {
110                 Filter const * f = Filter::from_id ((*i)->content ());
111                 if (f) {
112                         _filters.push_back (f);
113                 } else {
114                         notes.push_back (String::compose (_("DCP-o-matic no longer supports the `%1' filter, so it has been turned off."), (*i)->content()));
115                 }
116         }
117
118         optional<ContentTime::Type> const f = node->optional_number_child<ContentTime::Type> ("FirstVideo");
119         if (f) {
120                 _first_video = ContentTime (f.get ());
121         }
122
123         _color_range = get_optional_enum<AVColorRange>(node, "ColorRange");
124         _color_primaries = get_optional_enum<AVColorPrimaries>(node, "ColorPrimaries");
125         _color_trc = get_optional_enum<AVColorTransferCharacteristic>(node, "ColorTransferCharacteristic");
126         _colorspace = get_optional_enum<AVColorSpace>(node, "Colorspace");
127         _bits_per_pixel = node->optional_number_child<int> ("BitsPerPixel");
128
129 }
130
131 FFmpegContent::FFmpegContent (shared_ptr<const Film> film, vector<shared_ptr<Content> > c)
132         : Content (film, c)
133 {
134         vector<shared_ptr<Content> >::const_iterator i = c.begin ();
135
136         bool need_video = false;
137         bool need_audio = false;
138         bool need_subtitle = false;
139
140         if (i != c.end ()) {
141                 need_video = static_cast<bool> ((*i)->video);
142                 need_audio = static_cast<bool> ((*i)->audio);
143                 need_subtitle = static_cast<bool> ((*i)->subtitle);
144         }
145
146         while (i != c.end ()) {
147                 if (need_video != static_cast<bool> ((*i)->video)) {
148                         throw JoinError (_("Content to be joined must all have or not have video"));
149                 }
150                 if (need_audio != static_cast<bool> ((*i)->audio)) {
151                         throw JoinError (_("Content to be joined must all have or not have audio"));
152                 }
153                 if (need_subtitle != static_cast<bool> ((*i)->subtitle)) {
154                         throw JoinError (_("Content to be joined must all have or not have subtitles"));
155                 }
156                 ++i;
157         }
158
159         if (need_video) {
160                 video.reset (new VideoContent (this, c));
161         }
162         if (need_audio) {
163                 audio.reset (new AudioContent (this, c));
164         }
165         if (need_subtitle) {
166                 subtitle.reset (new TextContent (this, c));
167         }
168
169         shared_ptr<FFmpegContent> ref = dynamic_pointer_cast<FFmpegContent> (c[0]);
170         DCPOMATIC_ASSERT (ref);
171
172         for (size_t i = 0; i < c.size(); ++i) {
173                 shared_ptr<FFmpegContent> fc = dynamic_pointer_cast<FFmpegContent> (c[i]);
174                 if (fc->subtitle && fc->subtitle->use() && *(fc->_subtitle_stream.get()) != *(ref->_subtitle_stream.get())) {
175                         throw JoinError (_("Content to be joined must use the same subtitle stream."));
176                 }
177         }
178
179         /* XXX: should probably check that more of the stuff below is the same in *this and ref */
180
181         _subtitle_streams = ref->subtitle_streams ();
182         _subtitle_stream = ref->subtitle_stream ();
183         _first_video = ref->_first_video;
184         _filters = ref->_filters;
185         _color_range = ref->_color_range;
186         _color_primaries = ref->_color_primaries;
187         _color_trc = ref->_color_trc;
188         _colorspace = ref->_colorspace;
189         _bits_per_pixel = ref->_bits_per_pixel;
190 }
191
192 void
193 FFmpegContent::as_xml (xmlpp::Node* node, bool with_paths) const
194 {
195         node->add_child("Type")->add_child_text ("FFmpeg");
196         Content::as_xml (node, with_paths);
197
198         if (video) {
199                 video->as_xml (node);
200         }
201
202         if (audio) {
203                 audio->as_xml (node);
204
205                 BOOST_FOREACH (AudioStreamPtr i, audio->streams ()) {
206                         shared_ptr<FFmpegAudioStream> f = dynamic_pointer_cast<FFmpegAudioStream> (i);
207                         DCPOMATIC_ASSERT (f);
208                         f->as_xml (node->add_child("AudioStream"));
209                 }
210         }
211
212         if (subtitle) {
213                 subtitle->as_xml (node);
214         }
215
216         boost::mutex::scoped_lock lm (_mutex);
217
218         for (vector<shared_ptr<FFmpegSubtitleStream> >::const_iterator i = _subtitle_streams.begin(); i != _subtitle_streams.end(); ++i) {
219                 xmlpp::Node* t = node->add_child("SubtitleStream");
220                 if (_subtitle_stream && *i == _subtitle_stream) {
221                         t->add_child("Selected")->add_child_text("1");
222                 }
223                 (*i)->as_xml (t);
224         }
225
226         for (vector<Filter const *>::const_iterator i = _filters.begin(); i != _filters.end(); ++i) {
227                 node->add_child("Filter")->add_child_text ((*i)->id ());
228         }
229
230         if (_first_video) {
231                 node->add_child("FirstVideo")->add_child_text (raw_convert<string> (_first_video.get().get()));
232         }
233
234         if (_color_range) {
235                 node->add_child("ColorRange")->add_child_text (raw_convert<string> (static_cast<int> (*_color_range)));
236         }
237         if (_color_primaries) {
238                 node->add_child("ColorPrimaries")->add_child_text (raw_convert<string> (static_cast<int> (*_color_primaries)));
239         }
240         if (_color_trc) {
241                 node->add_child("ColorTransferCharacteristic")->add_child_text (raw_convert<string> (static_cast<int> (*_color_trc)));
242         }
243         if (_colorspace) {
244                 node->add_child("Colorspace")->add_child_text (raw_convert<string> (static_cast<int> (*_colorspace)));
245         }
246         if (_bits_per_pixel) {
247                 node->add_child("BitsPerPixel")->add_child_text (raw_convert<string> (*_bits_per_pixel));
248         }
249 }
250
251 void
252 FFmpegContent::examine (shared_ptr<Job> job)
253 {
254         job->set_progress_unknown ();
255
256         Content::examine (job);
257
258         shared_ptr<FFmpegExaminer> examiner (new FFmpegExaminer (shared_from_this (), job));
259
260         if (examiner->has_video ()) {
261                 video.reset (new VideoContent (this));
262                 video->take_from_examiner (examiner);
263         }
264
265         boost::filesystem::path first_path = path (0);
266
267         {
268                 boost::mutex::scoped_lock lm (_mutex);
269
270                 if (examiner->has_video ()) {
271                         _first_video = examiner->first_video ();
272                         _color_range = examiner->color_range ();
273                         _color_primaries = examiner->color_primaries ();
274                         _color_trc = examiner->color_trc ();
275                         _colorspace = examiner->colorspace ();
276                         _bits_per_pixel = examiner->bits_per_pixel ();
277
278                         if (examiner->rotation()) {
279                                 double rot = *examiner->rotation ();
280                                 if (fabs (rot - 180) < 1.0) {
281                                         _filters.push_back (Filter::from_id ("vflip"));
282                                         _filters.push_back (Filter::from_id ("hflip"));
283                                 } else if (fabs (rot - 90) < 1.0) {
284                                         _filters.push_back (Filter::from_id ("90clock"));
285                                 } else if (fabs (rot - 270) < 1.0) {
286                                         _filters.push_back (Filter::from_id ("90anticlock"));
287                                 }
288                         }
289                 }
290
291                 if (!examiner->audio_streams().empty ()) {
292                         audio.reset (new AudioContent (this));
293
294                         BOOST_FOREACH (shared_ptr<FFmpegAudioStream> i, examiner->audio_streams ()) {
295                                 audio->add_stream (i);
296                         }
297
298                         AudioStreamPtr as = audio->streams().front();
299                         AudioMapping m = as->mapping ();
300                         film()->make_audio_mapping_default (m, first_path);
301                         as->set_mapping (m);
302                 }
303
304                 _subtitle_streams = examiner->subtitle_streams ();
305                 if (!_subtitle_streams.empty ()) {
306                         subtitle.reset (new TextContent (this));
307                         _subtitle_stream = _subtitle_streams.front ();
308                 }
309
310         }
311
312         if (examiner->has_video ()) {
313                 set_default_colour_conversion ();
314         }
315
316         signal_changed (FFmpegContentProperty::SUBTITLE_STREAMS);
317         signal_changed (FFmpegContentProperty::SUBTITLE_STREAM);
318 }
319
320 string
321 FFmpegContent::summary () const
322 {
323         if (video && audio) {
324                 return String::compose (_("%1 [movie]"), path_summary ());
325         } else if (video) {
326                 return String::compose (_("%1 [video]"), path_summary ());
327         } else if (audio) {
328                 return String::compose (_("%1 [audio]"), path_summary ());
329         }
330
331         return path_summary ();
332 }
333
334 string
335 FFmpegContent::technical_summary () const
336 {
337         string as = "";
338         BOOST_FOREACH (shared_ptr<FFmpegAudioStream> i, ffmpeg_audio_streams ()) {
339                 as += i->technical_summary () + " " ;
340         }
341
342         if (as.empty ()) {
343                 as = "none";
344         }
345
346         string ss = "none";
347         if (_subtitle_stream) {
348                 ss = _subtitle_stream->technical_summary ();
349         }
350
351         string filt = Filter::ffmpeg_string (_filters);
352
353         string s = Content::technical_summary ();
354
355         if (video) {
356                 s += " - " + video->technical_summary ();
357         }
358
359         if (audio) {
360                 s += " - " + audio->technical_summary ();
361         }
362
363         return s + String::compose (
364                 "ffmpeg: audio %1 subtitle %2 filters %3", as, ss, filt
365                 );
366 }
367
368 void
369 FFmpegContent::set_subtitle_stream (shared_ptr<FFmpegSubtitleStream> s)
370 {
371         {
372                 boost::mutex::scoped_lock lm (_mutex);
373                 _subtitle_stream = s;
374         }
375
376         signal_changed (FFmpegContentProperty::SUBTITLE_STREAM);
377 }
378
379 bool
380 operator== (FFmpegStream const & a, FFmpegStream const & b)
381 {
382         return a._id == b._id;
383 }
384
385 bool
386 operator!= (FFmpegStream const & a, FFmpegStream const & b)
387 {
388         return a._id != b._id;
389 }
390
391 DCPTime
392 FFmpegContent::full_length () const
393 {
394         FrameRateChange const frc (active_video_frame_rate (), film()->video_frame_rate ());
395         if (video) {
396                 return DCPTime::from_frames (llrint (video->length_after_3d_combine() * frc.factor()), film()->video_frame_rate());
397         }
398
399         DCPOMATIC_ASSERT (audio);
400
401         DCPTime longest;
402         BOOST_FOREACH (AudioStreamPtr i, audio->streams ()) {
403                 longest = max (longest, DCPTime::from_frames (llrint (i->length() / frc.speed_up), i->frame_rate()));
404         }
405
406         return longest;
407 }
408
409 void
410 FFmpegContent::set_filters (vector<Filter const *> const & filters)
411 {
412         {
413                 boost::mutex::scoped_lock lm (_mutex);
414                 _filters = filters;
415         }
416
417         signal_changed (FFmpegContentProperty::FILTERS);
418 }
419
420 string
421 FFmpegContent::identifier () const
422 {
423         string s = Content::identifier();
424
425         if (video) {
426                 s += "_" + video->identifier();
427         }
428
429         if (subtitle && subtitle->use() && subtitle->burn()) {
430                 s += "_" + subtitle->identifier();
431         }
432
433         boost::mutex::scoped_lock lm (_mutex);
434
435         if (_subtitle_stream) {
436                 s += "_" + _subtitle_stream->identifier ();
437         }
438
439         for (vector<Filter const *>::const_iterator i = _filters.begin(); i != _filters.end(); ++i) {
440                 s += "_" + (*i)->id ();
441         }
442
443         return s;
444 }
445
446 void
447 FFmpegContent::set_default_colour_conversion ()
448 {
449         DCPOMATIC_ASSERT (video);
450
451         dcp::Size const s = video->size ();
452
453         boost::mutex::scoped_lock lm (_mutex);
454
455         switch (_colorspace.get_value_or(AVCOL_SPC_UNSPECIFIED)) {
456         case AVCOL_SPC_RGB:
457                 video->set_colour_conversion (PresetColourConversion::from_id ("srgb").conversion);
458                 break;
459         case AVCOL_SPC_BT709:
460                 video->set_colour_conversion (PresetColourConversion::from_id ("rec709").conversion);
461                 break;
462         case AVCOL_SPC_BT470BG:
463         case AVCOL_SPC_SMPTE170M:
464         case AVCOL_SPC_SMPTE240M:
465                 video->set_colour_conversion (PresetColourConversion::from_id ("rec601").conversion);
466                 break;
467         case AVCOL_SPC_BT2020_CL:
468         case AVCOL_SPC_BT2020_NCL:
469                 video->set_colour_conversion (PresetColourConversion::from_id ("rec2020").conversion);
470                 break;
471         default:
472                 if (s.width < 1080) {
473                         video->set_colour_conversion (PresetColourConversion::from_id ("rec601").conversion);
474                 } else {
475                         video->set_colour_conversion (PresetColourConversion::from_id ("rec709").conversion);
476                 }
477                 break;
478         }
479 }
480
481 void
482 FFmpegContent::add_properties (list<UserProperty>& p) const
483 {
484         Content::add_properties (p);
485
486         if (video) {
487                 video->add_properties (p);
488
489                 if (_bits_per_pixel) {
490                         int const sub = 219 * pow (2, _bits_per_pixel.get() - 8);
491                         int const total = pow (2, _bits_per_pixel.get());
492
493                         switch (_color_range.get_value_or(AVCOL_RANGE_UNSPECIFIED)) {
494                         case AVCOL_RANGE_UNSPECIFIED:
495                                 /// TRANSLATORS: this means that the range of pixel values used in this
496                                 /// file is unknown (not specified in the file).
497                                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour range"), _("Unspecified")));
498                                 break;
499                         case AVCOL_RANGE_MPEG:
500                                 /// TRANSLATORS: this means that the range of pixel values used in this
501                                 /// file is limited, so that not all possible values are valid.
502                                 p.push_back (
503                                         UserProperty (
504                                                 UserProperty::VIDEO, _("Colour range"), String::compose (_("Limited (%1-%2)"), (total - sub) / 2, (total + sub) / 2)
505                                                 )
506                                         );
507                                 break;
508                         case AVCOL_RANGE_JPEG:
509                                 /// TRANSLATORS: this means that the range of pixel values used in this
510                                 /// file is full, so that all possible pixel values are valid.
511                                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour range"), String::compose (_("Full (0-%1)"), total)));
512                                 break;
513                         default:
514                                 DCPOMATIC_ASSERT (false);
515                         }
516                 } else {
517                         switch (_color_range.get_value_or(AVCOL_RANGE_UNSPECIFIED)) {
518                         case AVCOL_RANGE_UNSPECIFIED:
519                                 /// TRANSLATORS: this means that the range of pixel values used in this
520                                 /// file is unknown (not specified in the file).
521                                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour range"), _("Unspecified")));
522                                 break;
523                         case AVCOL_RANGE_MPEG:
524                                 /// TRANSLATORS: this means that the range of pixel values used in this
525                                 /// file is limited, so that not all possible values are valid.
526                                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour range"), _("Limited")));
527                                 break;
528                         case AVCOL_RANGE_JPEG:
529                                 /// TRANSLATORS: this means that the range of pixel values used in this
530                                 /// file is full, so that all possible pixel values are valid.
531                                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour range"), _("Full")));
532                                 break;
533                         default:
534                                 DCPOMATIC_ASSERT (false);
535                         }
536                 }
537
538                 char const * primaries[] = {
539                         _("Unspecified"),
540                         _("BT709"),
541                         _("Unspecified"),
542                         _("Unspecified"),
543                         _("BT470M"),
544                         _("BT470BG"),
545                         _("SMPTE 170M (BT601)"),
546                         _("SMPTE 240M"),
547                         _("Film"),
548                         _("BT2020"),
549                         _("SMPTE ST 428-1 (CIE 1931 XYZ)"),
550                         _("SMPTE ST 431-2 (2011)"),
551                         _("SMPTE ST 432-1 D65 (2010)"), // 12
552                         "", // 13
553                         "", // 14
554                         "", // 15
555                         "", // 16
556                         "", // 17
557                         "", // 18
558                         "", // 19
559                         "", // 20
560                         "", // 21
561                         _("JEDEC P22")
562                 };
563
564                 DCPOMATIC_ASSERT (AVCOL_PRI_NB <= 23);
565                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour primaries"), primaries[_color_primaries.get_value_or(AVCOL_PRI_UNSPECIFIED)]));
566
567                 char const * transfers[] = {
568                         _("Unspecified"),
569                         _("BT709"),
570                         _("Unspecified"),
571                         _("Unspecified"),
572                         _("Gamma 22 (BT470M)"),
573                         _("Gamma 28 (BT470BG)"),
574                         _("SMPTE 170M (BT601)"),
575                         _("SMPTE 240M"),
576                         _("Linear"),
577                         _("Logarithmic (100:1 range)"),
578                         _("Logarithmic (316:1 range)"),
579                         _("IEC61966-2-4"),
580                         _("BT1361 extended colour gamut"),
581                         _("IEC61966-2-1 (sRGB or sYCC)"),
582                         _("BT2020 for a 10-bit system"),
583                         _("BT2020 for a 12-bit system"),
584                         _("SMPTE ST 2084 for 10, 12, 14 and 16 bit systems"),
585                         _("SMPTE ST 428-1"),
586                         _("ARIB STD-B67 ('Hybrid log-gamma')")
587                 };
588
589                 DCPOMATIC_ASSERT (AVCOL_TRC_NB <= 19);
590                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colour transfer characteristic"), transfers[_color_trc.get_value_or(AVCOL_TRC_UNSPECIFIED)]));
591
592                 char const * spaces[] = {
593                         _("RGB / sRGB (IEC61966-2-1)"),
594                         _("BT709"),
595                         _("Unspecified"),
596                         _("Unspecified"),
597                         _("FCC"),
598                         _("BT470BG (BT601-6)"),
599                         _("SMPTE 170M (BT601-6)"),
600                         _("SMPTE 240M"),
601                         _("YCOCG"),
602                         _("BT2020 non-constant luminance"),
603                         _("BT2020 constant luminance"),
604                         _("SMPTE 2085, Y'D'zD'x"),
605                         _("Chroma-derived non-constant luminance"),
606                         _("Chroma-derived constant luminance"),
607                         _("BT2100")
608                 };
609
610                 DCPOMATIC_ASSERT (AVCOL_SPC_NB == 15);
611                 p.push_back (UserProperty (UserProperty::VIDEO, _("Colourspace"), spaces[_colorspace.get_value_or(AVCOL_SPC_UNSPECIFIED)]));
612
613                 if (_bits_per_pixel) {
614                         p.push_back (UserProperty (UserProperty::VIDEO, _("Bits per pixel"), *_bits_per_pixel));
615                 }
616         }
617
618         if (audio) {
619                 audio->add_properties (p);
620         }
621 }
622
623 /** Our subtitle streams have colour maps, which can be changed, but
624  *  they have no way of signalling that change.  As a hack, we have this
625  *  method which callers can use when they've modified one of our subtitle
626  *  streams.
627  */
628 void
629 FFmpegContent::signal_subtitle_stream_changed ()
630 {
631         signal_changed (FFmpegContentProperty::SUBTITLE_STREAM);
632 }
633
634 vector<shared_ptr<FFmpegAudioStream> >
635 FFmpegContent::ffmpeg_audio_streams () const
636 {
637         vector<shared_ptr<FFmpegAudioStream> > fa;
638
639         if (audio) {
640                 BOOST_FOREACH (AudioStreamPtr i, audio->streams()) {
641                         fa.push_back (dynamic_pointer_cast<FFmpegAudioStream> (i));
642                 }
643         }
644
645         return fa;
646 }
647
648 void
649 FFmpegContent::take_settings_from (shared_ptr<const Content> c)
650 {
651         shared_ptr<const FFmpegContent> fc = dynamic_pointer_cast<const FFmpegContent> (c);
652         if (!fc) {
653                 return;
654                 }
655
656         Content::take_settings_from (c);
657         _filters = fc->_filters;
658 }