2 Copyright (C) 2013-2015 Carl Hetherington <cth@carlh.net>
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #include "subtitle_decoder.h"
21 #include "subtitle_content.h"
22 #include <boost/shared_ptr.hpp>
23 #include <boost/foreach.hpp>
27 using boost::shared_ptr;
28 using boost::optional;
30 SubtitleDecoder::SubtitleDecoder (shared_ptr<const SubtitleContent> c)
31 : _subtitle_content (c)
36 /** Called by subclasses when an image subtitle is ready.
37 * @param period Period of the subtitle.
38 * @param image Subtitle image.
39 * @param rect Area expressed as a fraction of the video frame that this subtitle
40 * is for (e.g. a width of 0.5 means the width of the subtitle is half the width
44 SubtitleDecoder::image_subtitle (ContentTimePeriod period, shared_ptr<Image> image, dcpomatic::Rect<double> rect)
46 _decoded_image_subtitles.push_back (ContentImageSubtitle (period, image, rect));
50 SubtitleDecoder::text_subtitle (ContentTimePeriod period, list<dcp::SubtitleString> s)
52 _decoded_text_subtitles.push_back (ContentTextSubtitle (period, s));
55 /** @param sp Full periods of subtitles that are showing or starting during the specified period */
58 SubtitleDecoder::get (list<T> const & subs, list<ContentTimePeriod> const & sp, ContentTimePeriod period, bool starting)
61 /* Nothing in this period */
65 /* Seek if what we want is before what we have, or a more than a little bit after.
66 Be careful with the length of this `little bit'; consider the case where the last
67 subs were just less than this little bit B ago. Then we will not seek, but instead
68 pass() for nearly B seconds; if we are a FFmpegDecoder then this will generate B's
69 worth of video which will stack up. If B + the pre-roll is bigger than the maximum
70 number of frames that the VideoDecoder will keep then we will get an assertion
71 failure in VideoDecoder.
73 if (subs.empty() || sp.back().to < subs.front().period().from || sp.front().from > (subs.back().period().to + ContentTime::from_seconds (1))) {
74 seek (sp.front().from, true);
77 /* Now enough pass() calls will either:
78 * (a) give us what we want, or
79 * (b) hit the end of the decoder.
81 while (!pass () && (subs.empty() || (subs.back().period().to < sp.back().to))) {}
83 /* Now look for what we wanted in the data we have collected */
84 /* XXX: inefficient */
87 for (typename list<T>::const_iterator i = subs.begin(); i != subs.end(); ++i) {
88 if ((starting && period.contains (i->period().from)) || (!starting && period.overlaps (i->period ()))) {
93 /* Discard anything in _decoded_image_subtitles that is outside 5 seconds either side of period */
95 list<ContentImageSubtitle>::iterator i = _decoded_image_subtitles.begin();
96 while (i != _decoded_image_subtitles.end()) {
97 list<ContentImageSubtitle>::iterator tmp = i;
101 i->period().to < (period.from - ContentTime::from_seconds (5)) ||
102 i->period().from > (period.to + ContentTime::from_seconds (5))
104 _decoded_image_subtitles.erase (i);
113 list<ContentTextSubtitle>
114 SubtitleDecoder::get_text_subtitles (ContentTimePeriod period, bool starting)
116 return get<ContentTextSubtitle> (_decoded_text_subtitles, text_subtitles_during (period, starting), period, starting);
119 list<ContentImageSubtitle>
120 SubtitleDecoder::get_image_subtitles (ContentTimePeriod period, bool starting)
122 return get<ContentImageSubtitle> (_decoded_image_subtitles, image_subtitles_during (period, starting), period, starting);
126 SubtitleDecoder::seek (ContentTime, bool)
128 _decoded_text_subtitles.clear ();
129 _decoded_image_subtitles.clear ();