Hi all, I've been playing around with dynamic pipelines lately , I've been refering to : the part-block.txt design doc but I would need more precisions : The context : I'm trying to change from a file to a rtp source and vice versa while keeping my encoder and destination ( rtp for now)  So that I keep the continuity of the rtp flow... Things i've done: I've created a element that restamps the buffers to allow continuity , I just adds the duration to the last ts ( I link this just before my encoder) And this element also intercetps EOS events in case my file ends before I switch to rtp , or if I wan't to switch to rtp after my file ends. Things i'm not sure how to do : My big problem is stopping the dataflow to allow my source change properly: I've tryed 2 approches 1. Having the pipeline in PLAYING and blocking (sync) my source pads .. then unlinking /removing (setting state to null before) my elements and adding /relinking my new elements This seems to work but there's still some problems : My main problem is if I change from udpsrc to file for example and there's no data going throught the udpsrc I won't ever block since no push is done , so I won't be able to change my pipeline .. (this can happen at the end of a rtp stream for example.. no eos , just no more data and I can't block :( ) Or if I try to change after a file went to EOS... same thing.. I could block ASYNC and wait for a timeout I guess and then on the timeout send a FLUSH_START event on the pipeline up to my encoder and before unblocking my pad send a FLUSH_STOP event... To make sure no buffer is going throught the part of the pipeline I will modify... But then there's the question of how much time should I wait ... :( Would this be a good way ? Or maybe another solution would be to send something from another thread to make sure it will block but I wonder what I could send that wouldn't affect my pipeline and still do a push on the pad.... ideas ? Or if you ppl see any other solutions ? 2. I've tryed too setting the pipeline to PAUSED and blocking my src pads async But In that case I get weird problem like when removing an element like ffdec_mpeg4 that is completly unlinked ... seems like on post_activate the pad will that GST_PAD_STREAM_LOCK(pad) and that will try to lock the sink element ( basesink_do_sync) but it's already locked since i'm in PAUSED and then I deadlock, I really wonder why I trys to lock the sink when it's not linked to the pipeline anymore :( So going to paused to do this seems bad to me... am I right ? Thanks a lot , your help is very apreciated :)