Extract and fix closed text display logic (#2857).

This was buggy, but here it is extracted, fixed and gains a basic test.

2 files changed, 78 insertions, 0 deletions

diff --git a/test/closed_text_display_test.cc b/test/closed_text_display_test.cc
new file mode 100644
index 000000000..e3494471c
--- /dev/null
+++ b/test/closed_text_display_test.cc
@@ -0,0 +1,77 @@
+/*
+    Copyright (C) 2024 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "lib/butler.h"
+#include "lib/closed_text_display.h"
+#include "lib/content_factory.h"
+#include "lib/cross.h"
+#include "lib/dcpomatic_time.h"
+#include "lib/image.h"
+#include "lib/film.h"
+#include "lib/player.h"
+#include "lib/text_content.h"
+#include "test.h"
+#include <boost/test/unit_test.hpp>
+#include <memory>
+
+
+BOOST_AUTO_TEST_CASE(closed_text_display_test1)
+{
+	auto text = content_factory("test/data/frames.srt");
+	auto film = new_test_film("closed_text_display_test1", text);
+
+	DCPTextTrack track("test", dcp::LanguageTag("de-DE"));
+	text[0]->text[0]->set_type(TextType::CLOSED_CAPTION);
+	text[0]->text[0]->set_dcp_track(track);
+	text[0]->text[0]->set_use(true);
+
+	Player player(film, Image::Alignment::COMPACT);
+	auto butler = std::make_shared<Butler>(
+		film, player, AudioMapping(), 2, boost::bind(PlayerVideo::force, AV_PIX_FMT_RGB24), VideoRange::FULL, Image::Alignment::PADDED, true, false, Butler::Audio::DISABLED
+		);
+
+	auto await_butler = [butler]() {
+		while (butler->video_frames_in_buffer() < 4) {
+			dcpomatic_sleep_seconds(1);
+		}
+	};
+
+	await_butler();
+
+	ClosedTextDisplay display;
+	display.set_butler(butler);
+
+	display.update(dcpomatic::DCPTime::from_frames(2, 24), track);
+	BOOST_CHECK(display.current() == std::vector<std::string>{ "2" });
+
+	butler->seek({}, true);
+	await_butler();
+	display.update(dcpomatic::DCPTime::from_frames(0, 24), track);
+	BOOST_CHECK(display.current() == std::vector<std::string>{ "0" });
+
+	display.clear();
+	BOOST_CHECK(display.current().empty());
+
+	butler->seek(dcpomatic::DCPTime::from_frames(100, 24), true);
+	display.update(dcpomatic::DCPTime::from_frames(100, 24), track);
+	BOOST_CHECK(display.current().empty());
+}
+
diff --git a/test/wscript b/test/wscript
index cd23badc0..a13b9fa89 100644
--- a/test/wscript
+++ b/test/wscript
@@ -63,6 +63,7 @@ def build(bld):
                  cinema_sound_processor_test.cc
                  client_server_test.cc
                  closed_caption_test.cc
+                 closed_text_display_test.cc
                  collator_test.cc
                  colour_conversion_test.cc
                  config_test.cc