2 files changed, 17 insertions, 3 deletions
diff --git a/src/cpl.cc b/src/cpl.cc
index ee1817fc..74f6f0bd 100644
--- a/src/cpl.cc
+++ b/src/cpl.cc
@@ -747,3 +747,19 @@ CPL::set_additional_subtitle_languages (vector<dcp::LanguageTag> const& langs)
 		_additional_subtitle_languages.push_back (i.to_string());
 	}
 }
+
+
+void
+CPL::set_main_picture_active_area(dcp::Size area)
+{
+	if (area.width % 2) {
+		throw BadSettingError("Main picture active area width is not a multiple of 2");
+	}
+
+	if (area.height % 2) {
+		throw BadSettingError("Main picture active area height is not a multiple of 2");
+	}
+
+	_main_picture_active_area = area;
+}
+
diff --git a/src/cpl.h b/src/cpl.h
index c1489a2c..78e46c6a 100644
--- a/src/cpl.h
+++ b/src/cpl.h
@@ -307,9 +307,7 @@ public:
 		return _main_picture_active_area;
 	}
 
-	void set_main_picture_active_area (dcp::Size s) {
-		_main_picture_active_area = s;
-	}
+	void set_main_picture_active_area(dcp::Size area);
 
 	std::vector<std::string> additional_subtitle_languages () const {
 		return _additional_subtitle_languages;