fix up marshall/unmarshall of note data for MidiModel::DiffCommand

git-svn-id: svn://localhost/ardour2/branches/3.0@5662 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/evoral/src/SMF.cpp

@@ -19,6 +19,7 @@
 
 #define __STDC_LIMIT_MACROS 1
 #include <cassert>
+#include <cmath>
 #include <iostream>
 #include <stdint.h>
 #include "libsmf/smf.h"
@@ -262,5 +263,13 @@ SMF::end_write() THROW_FILE_ERROR
 		throw FileError();
 }
 
+double
+SMF::round_to_file_precision (double val) const
+{
+	double div = ppqn();
+
+	return round (val * div) / div;
+}
+
 
 } // namespace Evoral