Send OPTIONS request at a regular basis to standard RTSP servers as well,

this prevents a time-out which closes the TCP connection and kills our
session.

see "Re: [FFmpeg-devel] [PATCH] rtsp.c: keep-alive" thread on mailinglist.

Originally committed as revision 24785 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/rtsp.c

@@ -1902,9 +1902,7 @@ static int rtsp_read_packet(AVFormatContext *s, AVPacket *pkt)
         return ret;
 
     /* send dummy request to keep TCP connection alive */
-    if ((rt->server_type == RTSP_SERVER_WMS ||
-         rt->server_type == RTSP_SERVER_REAL) &&
-        (av_gettime() - rt->last_cmd_time) / 1000000 >= rt->timeout / 2) {
+    if ((av_gettime() - rt->last_cmd_time) / 1000000 >= rt->timeout / 2) {
         if (rt->server_type == RTSP_SERVER_WMS) {
             ff_rtsp_send_cmd_async(s, "GET_PARAMETER", rt->control_uri, NULL);
         } else {