Fix subtitles being written with negative times when trimmed (#2965).

2 files changed, 45 insertions, 25 deletions

diff --git a/src/lib/player.cc b/src/lib/player.cc
index e5abaae68..b5ee280ae 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -1233,16 +1233,40 @@ Player::audio(weak_ptr<Piece> weak_piece, AudioStreamPtr stream, ContentAudio co
 }
 
 
+/** @return from time if this text should be stored in _active_texts, otherwise nullopt */
+boost::optional<DCPTime>
+Player::should_store(weak_ptr<Piece> weak_piece, weak_ptr<const TextContent> weak_content, ContentTime subtitle_from) const
+{
+	if (_suspended) {
+		return {};
+	}
+
+	auto piece = weak_piece.lock();
+	auto content = weak_content.lock();
+	auto film = _film.lock();
+	if (!piece || !content || !film) {
+		return {};
+	}
+
+	DCPTime const from(content_time_to_dcp(piece, subtitle_from));
+	if (from > piece->content->end(film)) {
+		return {};
+	}
+
+	return from;
+}
+
+
 void
 Player::bitmap_text_start(weak_ptr<Piece> weak_piece, weak_ptr<const TextContent> weak_content, ContentBitmapText subtitle)
 {
-	if (_suspended) {
+	auto from = should_store(weak_piece, weak_content, subtitle.from());
+	if (!from) {
 		return;
 	}
 
-	auto piece = weak_piece.lock();
 	auto content = weak_content.lock();
-	if (!piece || !content) {
+	if (!content) {
 		return;
 	}
 
@@ -1274,32 +1298,24 @@ Player::bitmap_text_start(weak_ptr<Piece> weak_piece, weak_ptr<const TextContent
 		ps.bitmap.push_back(BitmapText(image->scale(scaled_size, dcp::YUVToRGB::REC601, image->pixel_format(), Image::Alignment::PADDED, _fast), sub.rectangle));
 	}
 
-	DCPTime from(content_time_to_dcp(piece, subtitle.from()));
-	_active_texts[content->type()].add_from(weak_content, ps, from);
+	_active_texts[content->type()].add_from(weak_content, ps, *from);
 }
 
 
 void
 Player::plain_text_start(weak_ptr<Piece> weak_piece, weak_ptr<const TextContent> weak_content, ContentStringText subtitle)
 {
-	if (_suspended) {
+	auto from = should_store(weak_piece, weak_content, subtitle.from());
+	if (!from) {
 		return;
 	}
 
-	auto piece = weak_piece.lock();
 	auto content = weak_content.lock();
-	auto film = _film.lock();
-	if (!piece || !content || !film) {
+	if (!content) {
 		return;
 	}
 
 	PlayerText ps;
-	DCPTime const from(content_time_to_dcp(piece, subtitle.from()));
-
-	if (from > piece->content->end(film)) {
-		return;
-	}
-
 	for (auto s: subtitle.subs) {
 		s.set_h_position(s.h_position() + content->x_offset());
 		s.set_v_position(s.v_position() + content->y_offset());
@@ -1320,11 +1336,11 @@ Player::plain_text_start(weak_ptr<Piece> weak_piece, weak_ptr<const TextContent>
 			s.set_aspect_adjust(xs / ys);
 		}
 
-		s.set_in(dcp::Time(from.seconds(), 1000));
-		ps.string.push_back(s);
+		s.set_in(dcp::Time(from->seconds(), 1000));
+		ps.string.push_back (s);
 	}
 
-	_active_texts[content->type()].add_from(weak_content, ps, from);
+	_active_texts[content->type()].add_from(weak_content, ps, *from);
 }
 
 
@@ -1350,17 +1366,18 @@ Player::text_stop(weak_ptr<Piece> weak_piece, weak_ptr<const TextContent> weak_c
 		return;
 	}
 
-	DCPTime const dcp_to = content_time_to_dcp(piece, to);
+	auto dcp_to = content_time_to_dcp(piece, to);
+	auto from = _active_texts[content->type()].add_to(weak_content, dcp_to);
+	auto subtitle_period = DCPTimePeriod(from.second, dcp_to);
 
-	if (dcp_to > piece->content->end(film)) {
+	auto overlap = piece->content->period(film).overlap(subtitle_period);
+	if (!overlap) {
 		return;
 	}
 
-	auto from = _active_texts[content->type()].add_to(weak_content, dcp_to);
-
 	bool const always = (content->type() == TextType::OPEN_SUBTITLE && _always_burn_open_subtitles);
 	if (content->use() && !always && !content->burn()) {
-		Text(from.first, content->type(), content->dcp_track().get_value_or(DCPTextTrack()), DCPTimePeriod(from.second, dcp_to));
+		Text(from.first, content->type(), content->dcp_track().get_value_or(DCPTextTrack()), *overlap);
 	}
 }
 
diff --git a/src/lib/player.h b/src/lib/player.h
index 5148ad3a1..8922741bd 100644
--- a/src/lib/player.h
+++ b/src/lib/player.h
@@ -177,8 +177,11 @@ private:
 	boost::optional<PositionImage> open_texts_for_frame(dcpomatic::DCPTime time) const;
 	void emit_video(std::shared_ptr<PlayerVideo> pv, dcpomatic::DCPTime time);
 	void use_video(std::shared_ptr<PlayerVideo> pv, dcpomatic::DCPTime time, dcpomatic::DCPTime end);
-	void emit_audio(std::shared_ptr<AudioBuffers> data, dcpomatic::DCPTime time);
-	std::shared_ptr<const Playlist> playlist() const;
+	void emit_audio (std::shared_ptr<AudioBuffers> data, dcpomatic::DCPTime time);
+	std::shared_ptr<const Playlist> playlist () const;
+	boost::optional<dcpomatic::DCPTime> should_store(
+		std::weak_ptr<Piece> weak_piece, std::weak_ptr<const TextContent> weak_content, dcpomatic::ContentTime subtitle_from
+	) const;
 
 	/** Mutex to protect the most of the Player state.  When it's used for the preview we have
 	    seek() and pass() called from the Butler thread and lots of other stuff called