Index: res/res_monitor.c
===================================================================
--- res/res_monitor.c	(revision 89398)
+++ res/res_monitor.c	(working copy)
@@ -424,6 +424,7 @@
 	char *arg = NULL;
 	char *options = NULL;
 	char *delay = NULL;
+	char *format = NULL;
 	char *urlprefix = NULL;
 	char tmp[256];
 	int stream_action = X_REC_IN | X_REC_OUT;
@@ -446,24 +447,34 @@
 	parse = ast_strdupa((char*)data);
 	AST_STANDARD_APP_ARGS(args, parse);
 
-	if (strchr(args.options, 'm'))
-		stream_action |= X_JOIN;
-	if (strchr(args.options, 'b'))
-		waitforbridge = 1;
-	if (strchr(args.options, 'i'))
-		stream_action &= ~X_REC_IN;
-	if (strchr(args.options, 'o'))
-		stream_action &= ~X_REC_OUT;
+	if (args.options) {
+		if (strchr(args.options, 'm'))
+			stream_action |= X_JOIN;
+		if (strchr(args.options, 'b'))
+			waitforbridge = 1;
+		if (strchr(args.options, 'i'))
+			stream_action &= ~X_REC_IN;
+		if (strchr(args.options, 'o'))
+			stream_action &= ~X_REC_OUT;
+	}
 
-	arg = strchr(args.format, ':');
-	if (arg) {
-		*arg++ = 0;
-		urlprefix = arg;
+	if (args.format) {
+		format = args.format;
+		arg = strchr(args.format, ':');
+		if (arg) {
+			*arg++ = 0;
+			urlprefix = arg;
+		}
 	}
 
+	if (format && strcasecmp(format, "gsm") == 0)
+		format = "gsm";
+	else
+		format = "wav";
+
 	if (urlprefix) {
 		snprintf(tmp, sizeof(tmp), "%s/%s.%s", urlprefix, args.fname_base,
-			((strcmp(args.format, "gsm")) ? "wav" : "gsm"));
+			format);
 		if (!chan->cdr && !(chan->cdr = ast_cdr_alloc()))
 			return -1;
 		ast_cdr_setuserfield(chan, tmp);
@@ -485,7 +496,7 @@
 		return 0;
 	}
 
-	res = ast_monitor_start(chan, args.format, args.fname_base, 1, stream_action);
+	res = ast_monitor_start(chan, format, args.fname_base, 1, stream_action);
 	if (res < 0)
 		res = ast_monitor_change_fname(chan, args.fname_base, 1);