Index: res/res_rtp_asterisk.c
===================================================================
--- res/res_rtp_asterisk.c	(revision 311921)
+++ res/res_rtp_asterisk.c	(working copy)
@@ -2311,7 +2311,8 @@
 		rtp->f.delivery.tv_sec = 0;
 		rtp->f.delivery.tv_usec = 0;
 		/* Pass the RTP marker bit as bit */
-		ast_format_set_video_mark(&rtp->f.subclass.format);
+		if(mark)
+			ast_format_set_video_mark(&rtp->f.subclass.format);
 	} else {
 		/* TEXT -- samples is # of samples vs. 1000 */
 		if (!rtp->lastitexttimestamp)