libsaria: Create a durstr() function

Call this to get a string representation of the pipeline's current
duration.

include/libsaria/audio.h

@@ -29,6 +29,7 @@ namespace libsaria
 		gint64 duration();
 		gint64 position();
 		string posstr();
+		string durstr();
 
 		/* Volume functions */
 		double get_volume();

libsaria/audio/progress.cpp

@@ -21,6 +21,20 @@ static bool get_position(gint64 &position)
 					  &position);
 }
 
+static string to_string(gint64 &time)
+	{
+		stringstream stream;
+		int minutes, seconds;
+
+		time = time / GST_SECOND;
+		minutes = time / 60;
+		seconds = time - (minutes * 60);
+		stream << minutes << ":";
+		if (seconds < 10)
+			stream << "0";
+		stream << seconds;
+		return stream.str();
+	}
 namespace libsaria
 {
 
@@ -75,21 +89,18 @@ namespace libsaria
 
 	string audio::posstr()
 	{
-		stringstream stream;
 		gint64 pos;
-		int minutes, seconds;
-
 		if (!get_position(pos))
 			return "";
+		return to_string(pos);
+	}
 
-		pos = pos / GST_SECOND;
-		minutes = pos / 60;
-		seconds = pos - (minutes * 60);
-		stream << minutes << ":";
-		if (seconds < 10)
-			stream << "0";
-		stream << seconds;
-		return stream.str();
+	string audio::durstr()
+	{
+		gint64 dur;
+		if (!get_duration(dur))
+			return "";
+		return to_string(dur);
 	}
 
 };