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>
28 using boost::shared_ptr;
29 using boost::optional;
31 SubtitleDecoder::SubtitleDecoder (shared_ptr<const SubtitleContent> c)
32 : _subtitle_content (c)
37 /** Called by subclasses when an image subtitle is ready.
38 * @param period Period of the subtitle.
39 * @param image Subtitle image.
40 * @param rect Area expressed as a fraction of the video frame that this subtitle
41 * is for (e.g. a width of 0.5 means the width of the subtitle is half the width
45 SubtitleDecoder::image_subtitle (ContentTimePeriod period, shared_ptr<Image> image, dcpomatic::Rect<double> rect)
47 _decoded_image_subtitles.push_back (ContentImageSubtitle (period, image, rect));
51 SubtitleDecoder::text_subtitle (ContentTimePeriod period, list<dcp::SubtitleString> s)
53 _decoded_text_subtitles.push_back (ContentTextSubtitle (period, s));
56 /** @param sp Full periods of subtitles that are showing or starting during the specified period */
59 SubtitleDecoder::get (list<T> const & subs, list<ContentTimePeriod> const & sp, ContentTimePeriod period, bool starting)
62 /* Nothing in this period */
66 /* Seek if what we want is before what we have, or a more than a little bit after.
67 Be careful with the length of this `little bit'; consider the case where the last
68 subs were just less than this little bit B ago. Then we will not seek, but instead
69 pass() for nearly B seconds; if we are a FFmpegDecoder then this will generate B's
70 worth of video which will stack up. If B + the pre-roll is bigger than the maximum
71 number of frames that the VideoDecoder will keep then we will get an assertion
72 failure in VideoDecoder.
74 if (subs.empty() || sp.back().to < subs.front().period().from || sp.front().from > (subs.back().period().to + ContentTime::from_seconds (1))) {
75 seek (sp.front().from, true);
78 /* Now enough pass() calls will either:
79 * (a) give us what we want, or
80 * (b) hit the end of the decoder.
82 while (!pass () && (subs.empty() || (subs.back().period().to < sp.back().to))) {}
84 /* Now look for what we wanted in the data we have collected */
85 /* XXX: inefficient */
88 for (typename list<T>::const_iterator i = subs.begin(); i != subs.end(); ++i) {
89 if ((starting && period.contains (i->period().from)) || (!starting && period.overlaps (i->period ()))) {
94 /* Discard anything in _decoded_image_subtitles that is outside 5 seconds either side of period */
96 list<ContentImageSubtitle>::iterator i = _decoded_image_subtitles.begin();
97 while (i != _decoded_image_subtitles.end()) {
98 list<ContentImageSubtitle>::iterator tmp = i;
102 i->period().to < (period.from - ContentTime::from_seconds (5)) ||
103 i->period().from > (period.to + ContentTime::from_seconds (5))
105 _decoded_image_subtitles.erase (i);
114 list<ContentTextSubtitle>
115 SubtitleDecoder::get_text_subtitles (ContentTimePeriod period, bool starting)
117 return get<ContentTextSubtitle> (_decoded_text_subtitles, text_subtitles_during (period, starting), period, starting);
120 list<ContentImageSubtitle>
121 SubtitleDecoder::get_image_subtitles (ContentTimePeriod period, bool starting)
123 return get<ContentImageSubtitle> (_decoded_image_subtitles, image_subtitles_during (period, starting), period, starting);
127 SubtitleDecoder::seek (ContentTime, bool)
129 _decoded_text_subtitles.clear ();
130 _decoded_image_subtitles.clear ();