So i have two input source one is videotestsrc and another is autovideosrc, using tee i am doing sink as Xvimagesink and udpsink. When i use videotestsrc as shown in try 1, it works. But if i do try 2 it freeze (see the debug 3 logs please).

To reproduce try the second one and use a script (python, c, java) to change the add-pad to sink1.

Try 1: 

When i use this it works: ( Screen shot: http://i.imgur.com/v8PrZ.png ) 
- Here its working because you can see the ball 

videotestsrc ! queue ! s.sink0 videotestsrc pattern=18 ! queue ! s.sink1 input-selector name=s ! videoscale  ! video/x-raw-yuv,width=320,height=240,framerate=30/1 ! queue ! tee name=t ! queue ! xvimagesink name=gl t. ! queue ! rtppay ssrc=1 timestamp-offset=0 seqnum-offset=0 ! udpsink 

Try 2: 

When i use this it does not work ( Screen shot: http://i.imgur.com/24mdM.png) 
- Right screen you can see it does not show the camera 

videotestsrc ! queue ! s.sink0 autovideosrc ! queue ! s.sink1 input-selector name=s ! videoscale  ! video/x-raw-yuv,width=320,height=240,framerate=30/1 ! queue ! tee name=t ! queue ! xvimagesink name=gl t. ! queue ! rtppay ssrc=1 timestamp-offset=0 seqnum-offset=0 ! udpsink 

Debug=*:3: 

http://fpaste.org/z2zn/raw/