Make sure SMPTE subtitle MXFs get the right intrinsic duration.

2 files changed, 10 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 598636ff1..e3265c5e9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2015-10-06  Carl Hetherington  <cth@carlh.net>
 
+	* Fix invalid SMPTE subtitle output
+	in some cases.
+
 	* Speculative support for multi-part
 	bitmap subtitles (#709).
 
diff --git a/src/lib/writer.cc b/src/lib/writer.cc
index bace6602d..3f856737b 100644
--- a/src/lib/writer.cc
+++ b/src/lib/writer.cc
@@ -617,6 +617,13 @@ Writer::finish ()
 			boost::filesystem::create_directories (directory);
 			_subtitle_asset->write (directory / ("sub_" + _subtitle_asset->id() + ".xml"));
 		} else {
+			/* All our assets should be the same length; use the picture asset length here
+			   as a reference to set the subtitle one.
+			*/
+			dynamic_pointer_cast<dcp::SMPTESubtitleAsset>(_subtitle_asset)->set_intrinsic_duration (
+				reel_picture_asset->intrinsic_duration ()
+				);
+
 			_subtitle_asset->write (
 				_film->dir (_film->dcp_name ()) / ("sub_" + _subtitle_asset->id() + ".mxf")
 				);