Maintain frame-snap for position and trim when set_video_frame_rate is called (#1335).

3 files changed, 62 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 0ea7016b3..e51168502 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2018-07-09  Carl Hetherington  <cth@carlh.net>
+
+	* Keep video content position and trim on frame boundaries
+	even if the content's frame rate is forced to a new value (#1335).
+
 2018-07-07  Carl Hetherington  <cth@carlh.net>
 
 	* Add export buton for cinemas XML file (#1319).
diff --git a/src/lib/content.cc b/src/lib/content.cc
index f2380653f..2e4e77f8d 100644
--- a/src/lib/content.cc
+++ b/src/lib/content.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2013-2016 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2013-2018 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -360,6 +360,12 @@ Content::set_video_frame_rate (double r)
 	}
 
 	signal_changed (ContentProperty::VIDEO_FRAME_RATE);
+
+	/* Make sure things are still on frame boundaries */
+	if (video) {
+		set_position (position());
+		set_trim_start (trim_start());
+	}
 }
 
 void
diff --git a/test/content_test.cc b/test/content_test.cc
index 1ec3826ab..b077a96d6 100644
--- a/test/content_test.cc
+++ b/test/content_test.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2017 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2017-2018 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -76,3 +76,52 @@ BOOST_AUTO_TEST_CASE (content_test2)
 	film->make_dcp ();
 	BOOST_REQUIRE (!wait_for_jobs ());
 }
+
+/** Check that position and start trim of video content is forced to a frame boundary */
+BOOST_AUTO_TEST_CASE (content_test3)
+{
+	shared_ptr<Film> film = new_test_film2 ("content_test3");
+	film->set_sequence (false);
+
+	shared_ptr<Content> content = content_factory(film, "test/data/red_24.mp4").front();
+	film->examine_and_add_content (content);
+	BOOST_REQUIRE (!wait_for_jobs ());
+
+	/* Trim */
+
+	/* 12 frames */
+	content->set_trim_start (ContentTime::from_seconds (12.0 / 24.0));
+	BOOST_CHECK (content->trim_start() == ContentTime::from_seconds (12.0 / 24.0));
+
+	/* 11.2 frames */
+	content->set_trim_start (ContentTime::from_seconds (11.2 / 24.0));
+	BOOST_CHECK (content->trim_start() == ContentTime::from_seconds (11.0 / 24.0));
+
+	/* 13.9 frames */
+	content->set_trim_start (ContentTime::from_seconds (13.9 / 24.0));
+	BOOST_CHECK (content->trim_start() == ContentTime::from_seconds (14.0 / 24.0));
+
+	/* Position */
+
+	/* 12 frames */
+	content->set_position (DCPTime::from_seconds (12.0 / 24.0));
+	BOOST_CHECK (content->position() == DCPTime::from_seconds (12.0 / 24.0));
+
+	/* 11.2 frames */
+	content->set_position (DCPTime::from_seconds (11.2 / 24.0));
+	BOOST_CHECK (content->position() == DCPTime::from_seconds (11.0 / 24.0));
+
+	/* 13.9 frames */
+	content->set_position (DCPTime::from_seconds (13.9 / 24.0));
+	BOOST_CHECK (content->position() == DCPTime::from_seconds (14.0 / 24.0));
+
+	content->set_video_frame_rate (25);
+
+	/* Check that trim is fixed when the content's video frame rate is `forced' */
+
+	BOOST_CHECK (content->trim_start() == ContentTime::from_seconds (15.0 / 25.0));
+
+	/* Likewise position */
+
+	BOOST_CHECK (content->position() == DCPTime::from_seconds (15.0 / 25.0));
+}