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/*
Copyright (C) 2013-2015 Carl Hetherington <cth@carlh.net>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "subtitle_decoder.h"
#include "subtitle_content.h"
#include <boost/shared_ptr.hpp>
#include <boost/foreach.hpp>
#include <iostream>
using std::list;
using std::cout;
using boost::shared_ptr;
using boost::optional;
SubtitleDecoder::SubtitleDecoder (shared_ptr<const SubtitleContent> c)
: _subtitle_content (c)
{
}
/** Called by subclasses when an image subtitle is ready.
* @param period Period of the subtitle.
* @param image Subtitle image.
* @param rect Area expressed as a fraction of the video frame that this subtitle
* is for (e.g. a width of 0.5 means the width of the subtitle is half the width
* of the video frame)
*/
void
SubtitleDecoder::image_subtitle (ContentTimePeriod period, shared_ptr<Image> image, dcpomatic::Rect<double> rect)
{
_decoded_image_subtitles.push_back (ContentImageSubtitle (period, image, rect));
}
void
SubtitleDecoder::text_subtitle (ContentTimePeriod period, list<dcp::SubtitleString> s)
{
_decoded_text_subtitles.push_back (ContentTextSubtitle (period, s));
}
/** @param sp Full periods of subtitles that are showing or starting during the specified period */
template <class T>
list<T>
SubtitleDecoder::get (list<T> const & subs, list<ContentTimePeriod> const & sp, ContentTimePeriod period, bool starting)
{
if (sp.empty ()) {
/* Nothing in this period */
return list<T> ();
}
/* Seek if what we want is before what we have, or a more than a little bit after.
Be careful with the length of this `little bit'; consider the case where the last
subs were just less than this little bit B ago. Then we will not seek, but instead
pass() for nearly B seconds; if we are a FFmpegDecoder then this will generate B's
worth of video which will stack up. If B + the pre-roll is bigger than the maximum
number of frames that the VideoDecoder will keep then we will get an assertion
failure in VideoDecoder.
*/
if (subs.empty() || sp.back().to < subs.front().period().from || sp.front().from > (subs.back().period().to + ContentTime::from_seconds (1))) {
seek (sp.front().from, true);
}
/* Now enough pass() calls will either:
* (a) give us what we want, or
* (b) hit the end of the decoder.
*/
while (!pass () && (subs.empty() || (subs.back().period().to < sp.back().to))) {}
/* Now look for what we wanted in the data we have collected */
/* XXX: inefficient */
list<T> out;
for (typename list<T>::const_iterator i = subs.begin(); i != subs.end(); ++i) {
if ((starting && period.contains (i->period().from)) || (!starting && period.overlaps (i->period ()))) {
out.push_back (*i);
}
}
/* Discard anything in _decoded_image_subtitles that is outside 5 seconds either side of period */
list<ContentImageSubtitle>::iterator i = _decoded_image_subtitles.begin();
while (i != _decoded_image_subtitles.end()) {
list<ContentImageSubtitle>::iterator tmp = i;
++tmp;
if (
i->period().to < (period.from - ContentTime::from_seconds (5)) ||
i->period().from > (period.to + ContentTime::from_seconds (5))
) {
_decoded_image_subtitles.erase (i);
}
i = tmp;
}
return out;
}
list<ContentTextSubtitle>
SubtitleDecoder::get_text_subtitles (ContentTimePeriod period, bool starting)
{
return get<ContentTextSubtitle> (_decoded_text_subtitles, text_subtitles_during (period, starting), period, starting);
}
list<ContentImageSubtitle>
SubtitleDecoder::get_image_subtitles (ContentTimePeriod period, bool starting)
{
return get<ContentImageSubtitle> (_decoded_image_subtitles, image_subtitles_during (period, starting), period, starting);
}
void
SubtitleDecoder::seek (ContentTime, bool)
{
_decoded_text_subtitles.clear ();
_decoded_image_subtitles.clear ();
}
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