advanced: rtp/multicast: fix receiver url

fixes #49

advanced/streaming/stream_over_rtp.rst

@@ -127,7 +127,7 @@ To receive the stream, run the following code on the receiving devices:
 
 .. code-block ::
 
-   $ vlc rtp://239.255.255.250:5010
+   $ vlc rtp://@239.255.255.250:5010
 
 Note that for receiving the multicast stream, it is important to specify the multicast IP address. Diagramatically, following is how the network might look like in this scenario:
 
@@ -140,7 +140,7 @@ Note that for receiving the multicast stream, it is important to specify the mul
       { node [width=0 shape=point label=""]; two, one;
       }
       
-      { node [shape=plaintext]; "$ vlc sample.mp4 --sout=\"#rtp{\nmux=ts, dst=239.255.255.250, port=5010}\"", "$ vlc rtp://239.255.255.250:5010\nOn the Receiving Devices.";
+      { node [shape=plaintext]; "$ vlc sample.mp4 --sout=\"#rtp{\nmux=ts, dst=239.255.255.250, port=5010}\"", "$ vlc rtp://@239.255.255.250:5010\nOn the Receiving Devices.";
       }
       
       {node [shape=box] "\n  Network  \n  Switch  \n "
@@ -148,7 +148,7 @@ Note that for receiving the multicast stream, it is important to specify the mul
       
       "\n  Network  \n  Switch  \n " -> "Idle Device\n IP: 192.168.0.102" [label="The other devices can\nremain idle, although,\nthe stream will still be\npushed to them in case\nthey wish to connect."] 
       "Streaming Device \n IP: 192.168.0.101":w -> "$ vlc sample.mp4 --sout=\"#rtp{\nmux=ts, dst=239.255.255.250, port=5010}\"":w [style=invis]
-      "Idle Device\n IP: 192.168.0.102" -> "$ vlc rtp://239.255.255.250:5010\nOn the Receiving Devices." [style=invis]
+      "Idle Device\n IP: 192.168.0.102" -> "$ vlc rtp://@239.255.255.250:5010\nOn the Receiving Devices." [style=invis]
       "Receiving Device 2\n IP: 192.168.0.103" -> "Idle Device\n IP: 192.168.0.102" [style=invis]
       "Receiving Device 1\n IP: 192.168.0.107" -> "Receiving Device 2\n IP: 192.168.0.103" [style=invis]
       
@@ -186,4 +186,4 @@ You can use SAP announcements while streaming over RTP. This will help to "disco
 
 You can also use RTSP as the session management protocol. In this, the streaming will still happen over RTP but the session parameters (like IP address and the port number) will be negotiated by the RTSP protocol. Hence, the sender will not have to manually mention the IP address(es) of the receivers. Refer to :ref:`Stream using RTSP <stream-with-rtsp>` to understand how to use RTSP for streaming.
 
-Taking it a step further, it is possible to use both SAP and RTSP simultaneously. This gives the client the choice to either connect through the SAP discovery option, or by using the RTSP link.
\ No newline at end of file
+Taking it a step further, it is possible to use both SAP and RTSP simultaneously. This gives the client the choice to either connect through the SAP discovery option, or by using the RTSP link.