Slightly hacky fix for -114 errors during 3D encodes (#2173).

It still feels like I'm missing some large and beautiful trick
with gathering all the gap-filling code into one place, but
such a trick still eludes me.

2 files changed, 55 insertions, 0 deletions

diff --git a/src/lib/player.cc b/src/lib/player.cc
index a10654071..5e24dd44f 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -813,6 +813,19 @@ Player::pass ()
 		for (auto const& i: _delay) {
 			do_emit_video(i.first, i.second);
 		}
+
+		/* Perhaps we should have Empty entries for both eyes in the 3D case (somehow).
+		 * However, if we have L and R video files, and one is shorter than the other,
+		 * the fill code in ::video mostly takes care of filling in the gaps.
+		 * However, since it fills at the point when it knows there is more video coming
+		 * at time t (so it should fill any gap up to t) it can't do anything right at the
+		 * end.  This is particularly bad news if the last frame emitted is a LEFT
+		 * eye, as the MXF writer will complain about the 3D sequence being wrong.
+		 * Here's a hack to workaround that particular case.
+		 */
+		if (_next_video_eyes && _next_video_time && *_next_video_eyes == Eyes::RIGHT) {
+			do_emit_video (black_player_video_frame(Eyes::RIGHT), *_next_video_time);
+		}
 	}
 
 	return done;
diff --git a/test/threed_test.cc b/test/threed_test.cc
index 8523b5625..4fe91ebca 100644
--- a/test/threed_test.cc
+++ b/test/threed_test.cc
@@ -213,3 +213,45 @@ BOOST_AUTO_TEST_CASE (threed_test7)
 
 	JobManager::drop ();
 }
+
+
+/** Trigger a -114 error by trying to make a 3D DCP out of two files with slightly
+ *  different lengths.
+ */
+BOOST_AUTO_TEST_CASE (threed_test_separate_files_slightly_different_lengths)
+{
+	shared_ptr<Film> film = new_test_film2 ("threed_test3");
+	auto L = make_shared<FFmpegContent>("test/data/test.mp4");
+	film->examine_and_add_content (L);
+	auto R = make_shared<FFmpegContent>("test/data/test.mp4");
+	film->examine_and_add_content (R);
+	BOOST_REQUIRE (!wait_for_jobs());
+
+	L->video->set_frame_type (VideoFrameType::THREE_D_LEFT);
+	R->video->set_frame_type (VideoFrameType::THREE_D_RIGHT);
+	R->set_trim_end (dcpomatic::ContentTime::from_frames(1, 24));
+
+	film->set_three_d (true);
+	make_and_verify_dcp (film);
+}
+
+
+/** Trigger a -114 error by trying to make a 3D DCP out of two files with very
+ *  different lengths.
+ */
+BOOST_AUTO_TEST_CASE (threed_test_separate_files_very_different_lengths)
+{
+	shared_ptr<Film> film = new_test_film2 ("threed_test3");
+	auto L = make_shared<FFmpegContent>("test/data/test.mp4");
+	film->examine_and_add_content (L);
+	auto R = make_shared<FFmpegContent>("test/data/test.mp4");
+	film->examine_and_add_content (R);
+	BOOST_REQUIRE (!wait_for_jobs());
+
+	L->video->set_frame_type (VideoFrameType::THREE_D_LEFT);
+	R->video->set_frame_type (VideoFrameType::THREE_D_RIGHT);
+	R->set_trim_end (dcpomatic::ContentTime::from_seconds(1.5));
+
+	film->set_three_d (true);
+	make_and_verify_dcp (film);
+}