title: Gstreamer UDPSink output issue
body: <p>I have the following command I am using but somehow its not letting me send it over network(local). if I view local it works but not when I try with IP-address.</p>
  
  <pre><code>gst-launch-0.10 v4l2src device=/dev/video0 ! video/x-raw-yuv,width=320,height=240 ! videobox left=-320 border-alpha=0 ! queue ! videomixer name=mix ! ffmpegcolorspace ! xvimagesink v4l2src device=/dev/video1 ! video/x-raw-yuv,width=320,height=240 ! videobox left=1 ! queue ! send-config=true ! udpsink host=127.0.0.1 port=5000 
  </code></pre>
  
  <p>this gives me error:</p>
  
  <pre><code>WARNING: erroneous pipeline: link without source element
  </code></pre>
  
  <p>but without the udp it works fine.</p>
  
  <pre><code>gst-launch-0.10 v4l2src device=/dev/video0 ! video/x-raw-yuv,width=320,height=240 ! videobox left=-320 border-alpha=0 ! queue ! videomixer name=mix ! ffmpegcolorspace ! xvimagesink v4l2src device=/dev/video1 ! video/x-raw-yuv,width=320,height=240 ! videobox left=1 ! queue ! mix.
  </code></pre>
  
  <p>my client side is this:</p>
  
  <pre><code>gst-launch udpsrc uri=udp://127.0.0.1:5000 caps="application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)MP4V-ES, profile-level-id=(string)1, config=(string)000001b001000001b58913000001000000012000c48d88007d0a041e1463000001b24c61766335322e3132332e30, payload=(int)96, ssrc=(uint)298758266, clock-base=(uint)3097828288, seqnum-base=(uint)63478" ! rtpmp4vdepay ! ffdec_mpeg4 ! autovideosink
  </code></pre>
  
  <p>what am I doing wrong? Any help would be great.</p>