Reset _next_video_time when deciding to emit black.

Otherwise if we inaccurately seek into an area with no video there
will never be any content coming into ::video() which could reset
_next_video_time. Then when a black frame is emitted using
emit_video_until we will emit black frames from time 0 to the time
of the inaccurate seek.

2 files changed, 35 insertions, 0 deletions

diff --git a/src/lib/player.cc b/src/lib/player.cc
index 6f9b70d0a..03935a46b 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -774,6 +774,12 @@ Player::pass ()
 	}
 	case BLACK:
 		LOG_DEBUG_PLAYER ("Emit black for gap at %1", to_string(_black.position()));
+		if (!_next_video_time) {
+			/* Deciding to emit black has the same effect as getting some video from the content
+			 * when we are inaccurately seeking.
+			 */
+			_next_video_time = _black.position();
+		}
 		if (film->three_d()) {
 			use_video(black_player_video_frame(Eyes::LEFT), _black.position(), _black.period_at_position().to);
 			use_video(black_player_video_frame(Eyes::RIGHT), _black.position(), _black.period_at_position().to);
diff --git a/test/player_test.cc b/test/player_test.cc
index 5120c0180..530dfc770 100644
--- a/test/player_test.cc
+++ b/test/player_test.cc
@@ -54,6 +54,7 @@ using std::cout;
 using std::list;
 using std::shared_ptr;
 using std::make_shared;
+using std::vector;
 using boost::bind;
 using boost::optional;
 #if BOOST_VERSION >= 106100
@@ -710,3 +711,31 @@ BOOST_AUTO_TEST_CASE(three_d_in_two_d_chooses_left)
 	while (!player->pass()) {}
 }
 
+
+BOOST_AUTO_TEST_CASE(check_seek_with_no_video)
+{
+	auto content = content_factory(TestPaths::private_data() / "Fight.Club.1999.720p.BRRip.x264-x0r.srt")[0];
+	auto film = new_test_film2("check_seek_with_no_video", { content });
+	auto player = std::make_shared<Player>(film, film->playlist());
+
+	boost::signals2::signal<void (std::shared_ptr<PlayerVideo>, dcpomatic::DCPTime)> Video;
+
+	optional<dcpomatic::DCPTime> earliest;
+
+	player->Video.connect(
+		[&earliest](shared_ptr<PlayerVideo>, dcpomatic::DCPTime time) {
+			if (!earliest || time < *earliest) {
+				earliest = time;
+			}
+		});
+
+	player->seek(dcpomatic::DCPTime::from_seconds(60 * 60), false);
+
+	for (int i = 0; i < 10; ++i) {
+		player->pass();
+	}
+
+	BOOST_REQUIRE(earliest);
+	BOOST_CHECK(*earliest >= dcpomatic::DCPTime(60 * 60));
+}
+