Fill test disk partitions with random noise to expose more bugs.
[dcpomatic.git] / test / player_test.cc
index b6f864f8250e9762f0975eb16e6e79b38af8e360..80c7cf9eb44fc5509c7dd33a9fc1eb3493c08449 100644 (file)
 /*
-    Copyright (C) 2014 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2014-2021 Carl Hetherington <cth@carlh.net>
 
-    This program is free software; you can redistribute it and/or modify
+    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.
 
-    This program is distributed in the hope that it will be useful,
+    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 this program; if not, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
 
 */
 
+
 /** @file  test/player_test.cc
- *  @brief Various tests of Player.
+ *  @brief Test Player class.
+ *  @ingroup selfcontained
  */
 
-#include <iostream>
-#include <boost/test/unit_test.hpp>
-#include "lib/film.h"
-#include "lib/ffmpeg_content.h"
-#include "lib/dcp_content_type.h"
-#include "lib/ratio.h"
+
 #include "lib/audio_buffers.h"
+#include "lib/butler.h"
+#include "lib/compose.hpp"
+#include "lib/content_factory.h"
+#include "lib/cross.h"
+#include "lib/dcp_content.h"
+#include "lib/dcp_content_type.h"
+#include "lib/ffmpeg_content.h"
+#include "lib/film.h"
+#include "lib/image_content.h"
 #include "lib/player.h"
+#include "lib/ratio.h"
+#include "lib/string_text_file_content.h"
+#include "lib/text_content.h"
+#include "lib/video_content.h"
 #include "test.h"
+#include <boost/test/unit_test.hpp>
+#include <boost/algorithm/string.hpp>
+#include <iostream>
+
 
 using std::cout;
 using std::list;
-using boost::shared_ptr;
+using std::shared_ptr;
+using std::make_shared;
+using boost::bind;
+using boost::optional;
+#if BOOST_VERSION >= 106100
+using namespace boost::placeholders;
+#endif
+using namespace dcpomatic;
+
+
+static shared_ptr<AudioBuffers> accumulated;
+
+
+static void
+accumulate (shared_ptr<AudioBuffers> audio, DCPTime)
+{
+       BOOST_REQUIRE (accumulated);
+       accumulated->append (audio);
+}
+
+
+/** Check that the Player correctly generates silence when used with a silent FFmpegContent */
+BOOST_AUTO_TEST_CASE (player_silence_padding_test)
+{
+       auto film = new_test_film ("player_silence_padding_test");
+       film->set_name ("player_silence_padding_test");
+       auto c = std::make_shared<FFmpegContent>("test/data/test.mp4");
+       film->set_container (Ratio::from_id ("185"));
+       film->set_audio_channels (6);
+
+       film->examine_and_add_content (c);
+       BOOST_REQUIRE (!wait_for_jobs());
+
+       accumulated = std::make_shared<AudioBuffers>(film->audio_channels(), 0);
+
+       auto player = std::make_shared<Player>(film, Image::Alignment::COMPACT);
+       player->Audio.connect (bind (&accumulate, _1, _2));
+       while (!player->pass ()) {}
+       BOOST_REQUIRE (accumulated->frames() >= 48000);
+       BOOST_CHECK_EQUAL (accumulated->channels(), film->audio_channels ());
+
+       for (int i = 0; i < 48000; ++i) {
+               for (int c = 0; c < accumulated->channels(); ++c) {
+                       BOOST_CHECK_EQUAL (accumulated->data()[c][i], 0);
+               }
+       }
+}
+
 
-/** Player::overlaps */
-BOOST_AUTO_TEST_CASE (player_overlaps_test)
+/* Test insertion of black frames between separate bits of video content */
+BOOST_AUTO_TEST_CASE (player_black_fill_test)
 {
-       shared_ptr<Film> film = new_test_film ("player_overlaps_test");
+       auto film = new_test_film ("black_fill_test");
+       film->set_dcp_content_type (DCPContentType::from_isdcf_name ("FTR"));
+       film->set_name ("black_fill_test");
        film->set_container (Ratio::from_id ("185"));
-       shared_ptr<FFmpegContent> A (new FFmpegContent (film, "test/data/test.mp4"));
-       shared_ptr<FFmpegContent> B (new FFmpegContent (film, "test/data/test.mp4"));
-       shared_ptr<FFmpegContent> C (new FFmpegContent (film, "test/data/test.mp4"));
+       film->set_sequence (false);
+       film->set_interop (false);
+       auto contentA = std::make_shared<ImageContent>("test/data/simple_testcard_640x480.png");
+       auto contentB = std::make_shared<ImageContent>("test/data/simple_testcard_640x480.png");
 
+       film->examine_and_add_content (contentA);
+       film->examine_and_add_content (contentB);
+       BOOST_REQUIRE (!wait_for_jobs());
+
+       contentA->video->set_length (3);
+       contentA->set_position (film, DCPTime::from_frames(2, film->video_frame_rate()));
+       contentA->video->set_custom_ratio (1.85);
+       contentB->video->set_length (1);
+       contentB->set_position (film, DCPTime::from_frames(7, film->video_frame_rate()));
+       contentB->video->set_custom_ratio (1.85);
+
+       make_and_verify_dcp (
+               film,
+               {
+                       dcp::VerificationNote::Code::MISSING_FFMC_IN_FEATURE,
+                       dcp::VerificationNote::Code::MISSING_FFEC_IN_FEATURE
+               });
+
+       boost::filesystem::path ref;
+       ref = "test";
+       ref /= "data";
+       ref /= "black_fill_test";
+
+       boost::filesystem::path check;
+       check = "build";
+       check /= "test";
+       check /= "black_fill_test";
+       check /= film->dcp_name();
+
+       check_dcp (ref.string(), check.string());
+}
+
+
+/** Check behaviour with an awkward playlist whose data does not end on a video frame start */
+BOOST_AUTO_TEST_CASE (player_subframe_test)
+{
+       auto film = new_test_film ("reels_test7");
+       film->set_name ("reels_test7");
+       film->set_container (Ratio::from_id("185"));
+       film->set_dcp_content_type (DCPContentType::from_isdcf_name("TST"));
+       auto A = content_factory("test/data/flat_red.png").front();
        film->examine_and_add_content (A);
+       BOOST_REQUIRE (!wait_for_jobs());
+       auto B = content_factory("test/data/awkward_length.wav").front();
        film->examine_and_add_content (B);
-       film->examine_and_add_content (C);
-       wait_for_jobs ();
-
-       BOOST_CHECK_EQUAL (A->full_length(), DCPTime (288000));
+       BOOST_REQUIRE (!wait_for_jobs());
+       film->set_video_frame_rate (24);
+       A->video->set_length (3 * 24);
 
-       A->set_position (DCPTime::from_seconds (0));
-       B->set_position (DCPTime::from_seconds (10));
-       C->set_position (DCPTime::from_seconds (20));
+       BOOST_CHECK (A->full_length(film) == DCPTime::from_frames(3 * 24, 24));
+       BOOST_CHECK (B->full_length(film) == DCPTime(289920));
+       /* Length should be rounded up from B's length to the next video frame */
+       BOOST_CHECK (film->length() == DCPTime::from_frames(3 * 24 + 1, 24));
 
-       shared_ptr<Player> player = film->make_player ();
+       auto player = std::make_shared<Player>(film, Image::Alignment::COMPACT);
+       player->setup_pieces ();
+       BOOST_REQUIRE_EQUAL (player->_black._periods.size(), 1U);
+       BOOST_CHECK (player->_black._periods.front() == DCPTimePeriod(DCPTime::from_frames(3 * 24, 24), DCPTime::from_frames(3 * 24 + 1, 24)));
+       BOOST_REQUIRE_EQUAL (player->_silent._periods.size(), 1U);
+       BOOST_CHECK (player->_silent._periods.front() == DCPTimePeriod(DCPTime(289920), DCPTime::from_frames(3 * 24 + 1, 24)));
+}
 
-       list<shared_ptr<Piece> > o = player->overlaps<FFmpegContent> (DCPTime::from_seconds (0), DCPTime::from_seconds (5));
-       BOOST_CHECK_EQUAL (o.size(), 1);
-       BOOST_CHECK_EQUAL (o.front()->content, A);
 
-       o = player->overlaps<FFmpegContent> (DCPTime::from_seconds (5), DCPTime::from_seconds (8));
-       BOOST_CHECK_EQUAL (o.size(), 0);
+static Frame video_frames;
+static Frame audio_frames;
 
-       o = player->overlaps<FFmpegContent> (DCPTime::from_seconds (8), DCPTime::from_seconds (12));
-       BOOST_CHECK_EQUAL (o.size(), 1);
-       BOOST_CHECK_EQUAL (o.front()->content, B);
 
-       o = player->overlaps<FFmpegContent> (DCPTime::from_seconds (2), DCPTime::from_seconds (12));
-       BOOST_CHECK_EQUAL (o.size(), 2);
-       BOOST_CHECK_EQUAL (o.front()->content, A);
-       BOOST_CHECK_EQUAL (o.back()->content, B);
+static void
+video (shared_ptr<PlayerVideo>, DCPTime)
+{
+       ++video_frames;
+}
 
-       o = player->overlaps<FFmpegContent> (DCPTime::from_seconds (8), DCPTime::from_seconds (11));
-       BOOST_CHECK_EQUAL (o.size(), 1);
-       BOOST_CHECK_EQUAL (o.front()->content, B);
+static void
+audio (shared_ptr<AudioBuffers> audio, DCPTime)
+{
+       audio_frames += audio->frames();
 }
 
-/** Check that the Player correctly generates silence when used with a silent FFmpegContent */
-BOOST_AUTO_TEST_CASE (player_silence_padding_test)
+
+/** Check with a video-only file that the video and audio emissions happen more-or-less together */
+BOOST_AUTO_TEST_CASE (player_interleave_test)
 {
-       shared_ptr<Film> film = new_test_film ("player_silence_padding_test");
-       film->set_name ("player_silence_padding_test");
-       shared_ptr<FFmpegContent> c (new FFmpegContent (film, "test/data/test.mp4"));
+       auto film = new_test_film ("ffmpeg_transcoder_basic_test_subs");
+       film->set_name ("ffmpeg_transcoder_basic_test");
        film->set_container (Ratio::from_id ("185"));
        film->set_audio_channels (6);
-       
+
+       auto c = std::make_shared<FFmpegContent>("test/data/test.mp4");
        film->examine_and_add_content (c);
-       wait_for_jobs ();
+       BOOST_REQUIRE (!wait_for_jobs ());
+
+       auto s = std::make_shared<StringTextFileContent>("test/data/subrip.srt");
+       film->examine_and_add_content (s);
+       BOOST_REQUIRE (!wait_for_jobs ());
+
+       auto player = std::make_shared<Player>(film, Image::Alignment::COMPACT);
+       player->Video.connect (bind (&video, _1, _2));
+       player->Audio.connect (bind (&audio, _1, _2));
+       video_frames = audio_frames = 0;
+       while (!player->pass ()) {
+               BOOST_CHECK (abs(video_frames - (audio_frames / 2000)) <= 8);
+       }
+}
+
+
+/** Test some seeks towards the start of a DCP with awkward subtitles; see mantis #1085
+ *  and a number of others.  I thought this was a player seek bug but in fact it was
+ *  caused by the subtitle starting just after the start of the video frame and hence
+ *  being faded out.
+ */
+BOOST_AUTO_TEST_CASE (player_seek_test)
+{
+       auto film = std::make_shared<Film>(optional<boost::filesystem::path>());
+       auto dcp = std::make_shared<DCPContent>(TestPaths::private_data() / "awkward_subs");
+       film->examine_and_add_content (dcp, true);
+       BOOST_REQUIRE (!wait_for_jobs ());
+       dcp->only_text()->set_use (true);
+
+       auto player = std::make_shared<Player>(film, Image::Alignment::COMPACT);
+       player->set_fast ();
+       player->set_always_burn_open_subtitles ();
+       player->set_play_referenced ();
+
+       auto butler = std::make_shared<Butler>(
+               film, player, AudioMapping(), 2, bind(PlayerVideo::force, AV_PIX_FMT_RGB24), VideoRange::FULL, Image::Alignment::PADDED, true, false, Butler::Audio::DISABLED
+               );
+
+       for (int i = 0; i < 10; ++i) {
+               auto t = DCPTime::from_frames (i, 24);
+               butler->seek (t, true);
+               auto video = butler->get_video(Butler::Behaviour::BLOCKING, 0);
+               BOOST_CHECK_EQUAL(video.second.get(), t.get());
+               write_image(video.first->image(bind(PlayerVideo::force, AV_PIX_FMT_RGB24), VideoRange::FULL, true), String::compose("build/test/player_seek_test_%1.png", i));
+               /* This 14.08 is empirically chosen (hopefully) to accept changes in rendering between the reference and a test machine
+                  (17.10 and 16.04 seem to anti-alias a little differently) but to reject gross errors e.g. missing fonts or missing
+                  text altogether.
+               */
+               check_image(TestPaths::private_data() / String::compose("player_seek_test_%1.png", i), String::compose("build/test/player_seek_test_%1.png", i), 14.08);
+       }
+}
+
+
+/** Test some more seeks towards the start of a DCP with awkward subtitles */
+BOOST_AUTO_TEST_CASE (player_seek_test2)
+{
+       auto film = std::make_shared<Film>(optional<boost::filesystem::path>());
+       auto dcp = std::make_shared<DCPContent>(TestPaths::private_data() / "awkward_subs2");
+       film->examine_and_add_content (dcp, true);
+       BOOST_REQUIRE (!wait_for_jobs ());
+       dcp->only_text()->set_use (true);
+
+       auto player = std::make_shared<Player>(film, Image::Alignment::COMPACT);
+       player->set_fast ();
+       player->set_always_burn_open_subtitles ();
+       player->set_play_referenced ();
+
+       auto butler = std::make_shared<Butler>
+               (film, player, AudioMapping(), 2, bind(PlayerVideo::force, AV_PIX_FMT_RGB24), VideoRange::FULL, Image::Alignment::PADDED, true, false, Butler::Audio::DISABLED
+                );
+
+       butler->seek(DCPTime::from_seconds(5), true);
 
-       shared_ptr<Player> player = film->make_player ();
-       shared_ptr<AudioBuffers> test = player->get_audio (DCPTime (0), DCPTime::from_seconds (1), true);
-       BOOST_CHECK_EQUAL (test->frames(), 48000);
-       BOOST_CHECK_EQUAL (test->channels(), film->audio_channels ());
+       for (int i = 0; i < 10; ++i) {
+               auto t = DCPTime::from_seconds(5) + DCPTime::from_frames (i, 24);
+               butler->seek (t, true);
+               auto video = butler->get_video(Butler::Behaviour::BLOCKING, 0);
+               BOOST_CHECK_EQUAL(video.second.get(), t.get());
+               write_image(
+                       video.first->image(bind(PlayerVideo::force, AV_PIX_FMT_RGB24), VideoRange::FULL, true), String::compose("build/test/player_seek_test2_%1.png", i)
+                       );
+               check_image(TestPaths::private_data() / String::compose("player_seek_test2_%1.png", i), String::compose("build/test/player_seek_test2_%1.png", i), 14.08);
+       }
+}
+
+
+/** Test a bug when trimmed content follows other content */
+BOOST_AUTO_TEST_CASE (player_trim_test)
+{
+       auto film = new_test_film2 ("player_trim_test");
+       auto A = content_factory("test/data/flat_red.png").front();
+       film->examine_and_add_content (A);
+       BOOST_REQUIRE (!wait_for_jobs ());
+       A->video->set_length (10 * 24);
+       auto B = content_factory("test/data/flat_red.png").front();
+       film->examine_and_add_content (B);
+       BOOST_REQUIRE (!wait_for_jobs ());
+       B->video->set_length (10 * 24);
+       B->set_position (film, DCPTime::from_seconds(10));
+       B->set_trim_start (ContentTime::from_seconds (2));
+
+       make_and_verify_dcp (film);
+}
+
+
+struct Sub {
+       PlayerText text;
+       TextType type;
+       optional<DCPTextTrack> track;
+       DCPTimePeriod period;
+};
+
+
+static void
+store (list<Sub>* out, PlayerText text, TextType type, optional<DCPTextTrack> track, DCPTimePeriod period)
+{
+       Sub s;
+       s.text = text;
+       s.type = type;
+       s.track = track;
+       s.period = period;
+       out->push_back (s);
+}
+
+
+/** Test ignoring both video and audio */
+BOOST_AUTO_TEST_CASE (player_ignore_video_and_audio_test)
+{
+       auto film = new_test_film2 ("player_ignore_video_and_audio_test");
+       auto ff = content_factory(TestPaths::private_data() / "boon_telly.mkv").front();
+       film->examine_and_add_content (ff);
+       auto text = content_factory("test/data/subrip.srt").front();
+       film->examine_and_add_content (text);
+       BOOST_REQUIRE (!wait_for_jobs());
+       text->only_text()->set_type (TextType::CLOSED_CAPTION);
+       text->only_text()->set_use (true);
+
+       auto player = std::make_shared<Player>(film, Image::Alignment::COMPACT);
+       player->set_ignore_video ();
+       player->set_ignore_audio ();
+
+       list<Sub> out;
+       player->Text.connect (bind (&store, &out, _1, _2, _3, _4));
+       while (!player->pass ()) {}
+
+       BOOST_CHECK_EQUAL (out.size(), 6U);
+}
+
+
+/** Trigger a crash due to the assertion failure in Player::emit_audio */
+BOOST_AUTO_TEST_CASE (player_trim_crash)
+{
+       auto film = new_test_film2 ("player_trim_crash");
+       auto boon = content_factory(TestPaths::private_data() / "boon_telly.mkv").front();
+       film->examine_and_add_content (boon);
+       BOOST_REQUIRE (!wait_for_jobs());
+
+       auto player = std::make_shared<Player>(film, Image::Alignment::COMPACT);
+       player->set_fast ();
+       auto butler = std::make_shared<Butler>(
+               film, player, AudioMapping(), 6, bind(&PlayerVideo::force, AV_PIX_FMT_RGB24), VideoRange::FULL, Image::Alignment::COMPACT, true, false, Butler::Audio::ENABLED
+               );
+
+       /* Wait for the butler to fill */
+       dcpomatic_sleep_seconds (5);
+
+       boon->set_trim_start (ContentTime::from_seconds(5));
+
+       butler->seek (DCPTime(), true);
+
+       /* Wait for the butler to refill */
+       dcpomatic_sleep_seconds (5);
+
+       butler->rethrow ();
+}
+
+
+/** Test a crash when the gap between the last audio and the start of a silent period is more than 1 sample */
+BOOST_AUTO_TEST_CASE (player_silence_crash)
+{
+       auto film = new_test_film2 ("player_silence_crash");
+       auto sine = content_factory("test/data/impulse_train.wav").front();
+       film->examine_and_add_content (sine);
+       BOOST_REQUIRE (!wait_for_jobs());
+
+       sine->set_video_frame_rate (23.976);
+       film->write_metadata ();
+       make_and_verify_dcp (film, {dcp::VerificationNote::Code::MISSING_CPL_METADATA});
+}
+
+
+/** Test a crash when processing a 3D DCP */
+BOOST_AUTO_TEST_CASE (player_3d_test_1)
+{
+       auto film = new_test_film2 ("player_3d_test_1a");
+       auto left = content_factory("test/data/flat_red.png").front();
+       film->examine_and_add_content (left);
+       auto right = content_factory("test/data/flat_blue.png").front();
+       film->examine_and_add_content (right);
+       BOOST_REQUIRE (!wait_for_jobs());
+
+       left->video->set_frame_type (VideoFrameType::THREE_D_LEFT);
+       left->set_position (film, DCPTime());
+       right->video->set_frame_type (VideoFrameType::THREE_D_RIGHT);
+       right->set_position (film, DCPTime());
+       film->set_three_d (true);
 
-       for (int i = 0; i < test->frames(); ++i) {
-               for (int c = 0; c < test->channels(); ++c) {
-                       BOOST_CHECK_EQUAL (test->data()[c][i], 0);
+       make_and_verify_dcp (film);
+
+       auto dcp = std::make_shared<DCPContent>(film->dir(film->dcp_name()));
+       auto film2 = new_test_film2 ("player_3d_test_1b", {dcp});
+
+       film2->set_three_d (true);
+       make_and_verify_dcp (film2);
+}
+
+
+/** Test a crash when processing a 3D DCP as content in a 2D project */
+BOOST_AUTO_TEST_CASE (player_3d_test_2)
+{
+       auto left = content_factory("test/data/flat_red.png").front();
+       auto right = content_factory("test/data/flat_blue.png").front();
+       auto film = new_test_film2 ("player_3d_test_2a", {left, right});
+
+       left->video->set_frame_type (VideoFrameType::THREE_D_LEFT);
+       left->set_position (film, DCPTime());
+       right->video->set_frame_type (VideoFrameType::THREE_D_RIGHT);
+       right->set_position (film, DCPTime());
+       film->set_three_d (true);
+
+       make_and_verify_dcp (film);
+
+       auto dcp = std::make_shared<DCPContent>(film->dir(film->dcp_name()));
+       auto film2 = new_test_film2 ("player_3d_test_2b", {dcp});
+
+       make_and_verify_dcp (film2);
+}
+
+
+/** Test a crash when there is video-only content at the end of the DCP and a frame-rate conversion is happening;
+ *  #1691.
+ */
+BOOST_AUTO_TEST_CASE (player_silence_at_end_crash)
+{
+       /* 25fps DCP with some audio */
+       auto content1 = content_factory("test/data/flat_red.png").front();
+       auto film1 = new_test_film2 ("player_silence_at_end_crash_1", {content1});
+       content1->video->set_length (25);
+       film1->set_video_frame_rate (25);
+       make_and_verify_dcp (film1);
+
+       /* Make another project importing this DCP */
+       auto content2 = std::make_shared<DCPContent>(film1->dir(film1->dcp_name()));
+       auto film2 = new_test_film2 ("player_silence_at_end_crash_2", {content2});
+
+       /* and importing just the video MXF on its own at the end */
+       optional<boost::filesystem::path> video;
+       for (auto i: boost::filesystem::directory_iterator(film1->dir(film1->dcp_name()))) {
+               if (boost::starts_with(i.path().filename().string(), "j2c_")) {
+                       video = i.path();
                }
        }
+
+       BOOST_REQUIRE (video);
+       auto content3 = content_factory(*video).front();
+       film2->examine_and_add_content (content3);
+       BOOST_REQUIRE (!wait_for_jobs());
+       content3->set_position (film2, DCPTime::from_seconds(1.5));
+       film2->set_video_frame_rate (24);
+       make_and_verify_dcp (film2);
+}
+
+
+/** #2257 */
+BOOST_AUTO_TEST_CASE (encrypted_dcp_with_no_kdm_gives_no_butler_error)
+{
+       auto content = content_factory("test/data/flat_red.png").front();
+       auto film = new_test_film2 ("encrypted_dcp_with_no_kdm_gives_no_butler_error", { content });
+       int constexpr length = 24 * 25;
+       content->video->set_length(length);
+       film->set_encrypted (true);
+       make_and_verify_dcp (
+               film,
+               {
+                       dcp::VerificationNote::Code::MISSING_CPL_METADATA,
+               });
+
+       auto content2 = std::make_shared<DCPContent>(film->dir(film->dcp_name()));
+       auto film2 = new_test_film2 ("encrypted_dcp_with_no_kdm_gives_no_butler_error2", { content2 });
+
+       auto player = std::make_shared<Player>(film2, Image::Alignment::COMPACT);
+       Butler butler(film2, player, AudioMapping(), 2, bind(PlayerVideo::force, AV_PIX_FMT_RGB24), VideoRange::FULL, Image::Alignment::PADDED, true, false, Butler::Audio::ENABLED);
+
+       float buffer[2000 * 6];
+       for (int i = 0; i < length; ++i) {
+               butler.get_video(Butler::Behaviour::BLOCKING, 0);
+               butler.get_audio(Butler::Behaviour::BLOCKING, buffer, 2000);
+       }
+
+       BOOST_CHECK_NO_THROW(butler.rethrow());
+}
+
+
+BOOST_AUTO_TEST_CASE (interleaved_subtitle_are_emitted_correctly)
+{
+       boost::filesystem::path paths[2] = {
+               "build/test/interleaved_subtitle_are_emitted_correctly1.srt",
+               "build/test/interleaved_subtitle_are_emitted_correctly2.srt"
+       };
+
+       dcp::File subs_file[2] = { dcp::File(paths[0], "w"), dcp::File(paths[1], "w") };
+
+       fprintf(subs_file[0].get(), "1\n00:00:01,000 -> 00:00:02,000\nSub 1/1\n\n");
+       fprintf(subs_file[0].get(), "2\n00:00:05,000 -> 00:00:06,000\nSub 1/2\n\n");
+
+       fprintf(subs_file[1].get(), "1\n00:00:00,500 -> 00:00:01,500\nSub 2/1\n\n");
+       fprintf(subs_file[1].get(), "2\n00:00:02,000 -> 00:00:03,000\nSub 2/2\n\n");
+
+       subs_file[0].close();
+       subs_file[1].close();
+
+       auto subs1 = content_factory(paths[0]).front();
+       auto subs2 = content_factory(paths[1]).front();
+       auto film = new_test_film2("interleaved_subtitle_are_emitted_correctly", { subs1, subs2 });
+       film->set_sequence(false);
+       subs1->set_position(film, DCPTime());
+       subs2->set_position(film, DCPTime());
+
+       auto player = std::make_shared<Player>(film, Image::Alignment::COMPACT);
+       dcp::Time last;
+       player->Text.connect([&last](PlayerText text, TextType, optional<DCPTextTrack>, dcpomatic::DCPTimePeriod) {
+               for (auto sub: text.string) {
+                       BOOST_CHECK(sub.in() >= last);
+                       last = sub.in();
+               }
+       });
+       while (!player->pass()) {}
 }