--- a
+++ b/libupnpp/upnpavutils.cxx
@@ -0,0 +1,50 @@
+/* Copyright (C) 2014 J.F.Dockes
+ *       This program is free software; you can redistribute it and/or modify
+ *       it under the terms of the GNU General Public License as published by
+ *       the Free Software Foundation; either version 2 of the License, or
+ *       (at your option) any later version.
+ *
+ *       This program is distributed in the hope that it will be useful,
+ *       but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *       GNU General Public License for more details.
+ *
+ *       You should have received a copy of the GNU General Public License
+ *       along with this program; if not, write to the
+ *       Free Software Foundation, Inc.,
+ *       59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+#include <string>
+using namespace std;
+
+#include "libupnpp/upnpavutils.hxx"
+
+// Format duration in milliseconds into UPnP duration format
+string upnpduration(int ms)
+{
+    int hours = ms / (3600 * 1000);
+    ms -= hours * 3600 * 1000;
+    int minutes = ms / (60 * 1000);
+    ms -= minutes * 60 * 1000;
+    int secs = ms / 1000;
+    ms -= secs * 1000;
+
+    char cbuf[100];
+
+    // This is the format from the ref doc, but it appears that the
+    // decimal part in the seconds field is an issue with some control
+    // points. So drop it...
+    //  sprintf(cbuf, "%d:%02d:%02d.%03d", hours, minutes, secs, ms);
+    sprintf(cbuf, "%d:%02d:%02d", hours, minutes, secs);
+    return cbuf;
+}
+
+// H:M:S to seconds
+int upnpdurationtos(const string& dur)
+{
+    int hours, minutes, seconds;
+    if (sscanf(dur.c_str(), "%d:%d:%d", &hours, &minutes, &seconds) != 3) {
+	return 0;
+    }
+    return 3600 * hours + 60 * minutes + seconds;
+}