Give a better error.

diff --git a/src/lib/reel_writer.cc b/src/lib/reel_writer.cc
index 10d405961ad4af041128e72a9a3e39a6ee57fa0c..1e730259f5dd63d4be2ed77234d674db67998a12 100644 (file)
--- a/src/lib/reel_writer.cc
+++ b/src/lib/reel_writer.cc
@@ -493,7 +493,12 @@ ReelWriter::create_reel (list<ReferencedReelAsset> const & refs, list<shared_ptr
        }
 
        if (reel_subtitle_asset) {
-               DCPOMATIC_ASSERT (reel_subtitle_asset->duration() == period_duration);
+               if (reel_subtitle_asset->duration() != period_duration) {
+                       throw ProgrammingError (
+                               __FILE__, __LINE__,
+                               String::compose ("%1 vs %2", reel_subtitle_asset->duration(), period_duration)
+                               );
+               }
                reel->add (reel_subtitle_asset);
        }