Don't emit subtitle images that have a zero dimension (#2743).

They cause problems later when trying to blend them into the image.

4 files changed, 28 insertions, 3 deletions

diff --git a/run/tests b/run/tests
index 12d59346d..4315e227f 100755
--- a/run/tests
+++ b/run/tests
@@ -3,7 +3,7 @@
 # e.g. --run_tests=foo
 set -e
 
-PRIVATE_GIT="59b62615a48a1f3a70e9c028b92dfba75c1719ba"
+PRIVATE_GIT="f4b0c41b263a17cf33edae7565f16bd21eb80b65"
 
 if [ "$1" == "--check" ]; then
 	shift 1
diff --git a/src/lib/player.cc b/src/lib/player.cc
index ef7ecde5a..79b48ea71 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -921,7 +921,7 @@ Player::open_subtitles_for_frame (DCPTime time) const
 
 		/* Bitmap subtitles */
 		for (auto i: j.bitmap) {
-			if (!i.image) {
+			if (!i.image || i.image->size().width == 0 || i.image->size().height == 0) {
 				continue;
 			}
 
@@ -942,7 +942,10 @@ Player::open_subtitles_for_frame (DCPTime time) const
 		/* String subtitles (rendered to an image) */
 		if (!j.string.empty()) {
 			auto s = render_text(j.string, _video_container_size, time, vfr);
-			copy (s.begin(), s.end(), back_inserter (captions));
+			copy_if(s.begin(), s.end(), back_inserter(captions), [](PositionImage const& image) {
+				return image.image->size().width && image.image->size().height;
+			});
+
 		}
 	}
 
diff --git a/test/burnt_subtitle_test.cc b/test/burnt_subtitle_test.cc
index 9c6863a1d..8d7dcd143 100644
--- a/test/burnt_subtitle_test.cc
+++ b/test/burnt_subtitle_test.cc
@@ -30,6 +30,7 @@
 #include "lib/dcp_content.h"
 #include "lib/dcp_content_type.h"
 #include "lib/film.h"
+#include "lib/ffmpeg_encoder.h"
 #include "lib/log_entry.h"
 #include "lib/ratio.h"
 #include "lib/text_content.h"
@@ -184,3 +185,24 @@ BOOST_AUTO_TEST_CASE(burnt_subtitle_test_position)
 	/* Should have a baseline 864 pixels from the top ((1 - 0.2) * 1080) */
 	check("bottom");
 }
+
+
+/* Bug #2743 */
+BOOST_AUTO_TEST_CASE(burn_empty_subtitle_test)
+{
+	Cleanup cl;
+
+	auto content = content_factory("test/data/empty_sub.xml")[0];
+	auto film = new_test_film2("burnt_empty_subtitle_test", { content });
+	content->text[0]->set_use(true);
+
+	auto job = make_shared<TranscodeJob>(film, TranscodeJob::ChangedBehaviour::IGNORE);
+	auto file = boost::filesystem::path("build") / "test" / "burnt_empty_subtitle_test.mov";
+	cl.add(file);
+	FFmpegEncoder encoder(film, job, file, ExportFormat::PRORES_4444, false, false, false, 23);
+	encoder.go();
+
+	cl.run();
+}
+
+
diff --git a/test/data b/test/data
-Subproject a81d5737e54105f95d3d0cbf602dd355b881424
+Subproject 704f7643393caa29d77ddba138bff3642b273c4