From 9f8bdc77426b15f1f89110118ccb5c9903228351 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Fri, 5 May 2017 14:06:47 +0100
Subject: [PATCH] Keep active subtitles around until the video they are on has
 been emitted.

---
 src/lib/player.cc | 33 ++++++++++++++++++++++++---------
 src/lib/player.h  | 21 ++++++++++++++++++---
 2 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/src/lib/player.cc b/src/lib/player.cc
index 3de26ec90..06a1b008d 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -626,7 +626,7 @@ Player::video (weak_ptr<Piece> wp, ContentVideo video)
 
 	optional<PositionImage> subtitles;
 
-	for (ActiveSubtitles::const_iterator i = _active_subtitles.begin(); i != _active_subtitles.end(); ++i) {
+	for (ActiveSubtitlesMap::const_iterator i = _active_subtitles.begin(); i != _active_subtitles.end(); ++i) {
 
 		shared_ptr<Piece> sub_piece = i->first.lock ();
 		if (!sub_piece) {
@@ -637,17 +637,21 @@ Player::video (weak_ptr<Piece> wp, ContentVideo video)
 			continue;
 		}
 
-		pair<PlayerSubtitles, DCPTime> sub = i->second;
+		ActiveSubtitles sub = i->second;
+
+		if (sub.from > time || (sub.to && sub.to.get() <= time)) {
+			continue;
+		}
 
 		list<PositionImage> sub_images;
 
 		/* Image subtitles */
-		list<PositionImage> c = transform_image_subtitles (sub.first.image);
+		list<PositionImage> c = transform_image_subtitles (sub.subs.image);
 		copy (c.begin(), c.end(), back_inserter (sub_images));
 
 		/* Text subtitles (rendered to an image) */
-		if (!sub.first.text.empty ()) {
-			list<PositionImage> s = render_subtitles (sub.first.text, sub.first.fonts, _video_container_size, time);
+		if (!sub.subs.text.empty ()) {
+			list<PositionImage> s = render_subtitles (sub.subs.text, sub.subs.fonts, _video_container_size, time);
 			copy (s.begin (), s.end (), back_inserter (sub_images));
 		}
 
@@ -684,6 +688,15 @@ Player::video (weak_ptr<Piece> wp, ContentVideo video)
 	Video (_last_video, time);
 
 	_last_video_time = time + one_video_frame ();
+
+	/* Clear any finished _active_subtitles */
+	ActiveSubtitlesMap updated;
+	for (ActiveSubtitlesMap::const_iterator i = _active_subtitles.begin(); i != _active_subtitles.end(); ++i) {
+		if (!i->second.to || i->second.to.get() >= time) {
+			updated[i->first] = i->second;
+		}
+	}
+	_active_subtitles = updated;
 }
 
 void
@@ -836,7 +849,7 @@ Player::image_subtitle_start (weak_ptr<Piece> wp, ContentImageSubtitle subtitle)
 	ps.image.push_back (subtitle.sub);
 	DCPTime from (content_time_to_dcp (piece, subtitle.from()));
 
-	_active_subtitles[wp] = make_pair (ps, from);
+	_active_subtitles[wp] = ActiveSubtitles (ps, from);
 }
 
 void
@@ -875,7 +888,7 @@ Player::text_subtitle_start (weak_ptr<Piece> wp, ContentTextSubtitle subtitle)
 		ps.add_fonts (piece->content->subtitle->fonts ());
 	}
 
-	_active_subtitles[wp] = make_pair (ps, from);
+	_active_subtitles[wp] = ActiveSubtitles (ps, from);
 }
 
 void
@@ -890,11 +903,13 @@ Player::subtitle_stop (weak_ptr<Piece> wp, ContentTime to)
 		return;
 	}
 
+	DCPTime const dcp_to = content_time_to_dcp (piece, to);
+
 	if (piece->content->subtitle->use() && !_always_burn_subtitles && !piece->content->subtitle->burn()) {
-		Subtitle (_active_subtitles[wp].first, DCPTimePeriod (_active_subtitles[wp].second, content_time_to_dcp (piece, to)));
+		Subtitle (_active_subtitles[wp].subs, DCPTimePeriod (_active_subtitles[wp].from, dcp_to));
 	}
 
-	_active_subtitles.erase (wp);
+	_active_subtitles[wp].to = dcp_to;
 }
 
 void
diff --git a/src/lib/player.h b/src/lib/player.h
index 719e42895..18b47043a 100644
--- a/src/lib/player.h
+++ b/src/lib/player.h
@@ -152,7 +152,8 @@ private:
 
 	AudioMerger _audio_merger;
 
-	class StreamState {
+	class StreamState
+	{
 	public:
 		StreamState () {}
 
@@ -169,8 +170,22 @@ private:
 	std::list<DCPTimePeriod> _no_video;
 	std::list<DCPTimePeriod> _no_audio;
 
-	typedef std::map<boost::weak_ptr<Piece>, std::pair<PlayerSubtitles, DCPTime> > ActiveSubtitles;
-	ActiveSubtitles _active_subtitles;
+	class ActiveSubtitles
+	{
+	public:
+		ActiveSubtitles () {}
+
+		ActiveSubtitles (PlayerSubtitles s, DCPTime f)
+			: subs (s)
+			, from (f)
+		{}
+
+		PlayerSubtitles subs;
+		DCPTime from;
+		boost::optional<DCPTime> to;
+	};
+	typedef std::map<boost::weak_ptr<Piece>, ActiveSubtitles> ActiveSubtitlesMap;
+	ActiveSubtitlesMap _active_subtitles;
 
 	boost::shared_ptr<AudioProcessor> _audio_processor;
 	typedef std::map<std::pair<boost::shared_ptr<const AudioContent>, AudioStreamPtr>, boost::shared_ptr<Resampler> > ResamplerMap;
-- 
2.30.2