Hey Everyone, So I have a gnlcomposition which, for the matter of depicting the situation, has 5 sources. 3 sources play for 30 seconds followed by the remaining 2 sources for another 30 seconds. This should produce a 1 minute video. The composition has a videomixer in a gnloperation to mix the sources for final output. I'm running into a situation where the pipeline gets stuck during the transition from 3 sources to 2 sources. It seems the video mixer is trying to send a seek event to all it's sink pads, which fails on the pad which no-longer has a source. During my tests, the gnlcomposition will happily create new pads, ie. changing the order so it's 2 sources followed by 3 sources works fine. But the opposite doesn't seem to be true, the gnlcomposition doesn't remove unused pads to it's operations. This brings me to the question of, is there a signal I'm not handling appropriately? If so, any pointers on which one I should be listening for? Thanks, Tim