Thanks a lot for the answer. I'll take your advise into account. To follow up the issue I have to say that I have improved my recording by changing the valves the moment the pipeline is on pause, these way I don't stop the initialization and I don't have to take measures such as unblocking, flushing or whatever. The only problem I have left it's that some data is able to pass the valve before the dropping is on. Further the valves will work properly. I've been thinking on using the output-selector element - along with a fakesink as one of the selections -, but I couldn't make it work, neither findany suitable example around the web. About changing elements dynamically, I agree, it would bring new problems but I may use it on future improvements of the pipeline. I was able to get it work following the instructions on this link from GST: <a href="http://cgit.freedesktop.org/gstreamer/gstreamer/tree/docs/design/part-block.txt" target="_blank">http://cgit.freedesktop.org/gstreamer/gstreamer/tree/docs/design/part-block.txt</a> Anyway, I have learnt that many of the problems related to the states can be solved forcing flushing events but I need to know where - and if- a blockade has happened, so I will have to research on how gstreamer messages works. Cheers Hector <div class="gmail_quote">2011/3/16 4ernov <<a href="mailto:4ernov@gmail.com">4ernov@gmail.com</a>> <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">Hello, Hector, <div class="im"> > Hi everybody, > > I'm new in GStreamer but trying to move faster through it. > > I'm recording video with basic pipelines and now I'm trying to use valves to > regulate the record (stop/pause/cut...). > The problem is that the pipeline won't pass Prerolling when the valves are > initialised dropping. </div>I'd say using valves is not the best way for your case as it's very easy to drop some useful data (e.g. events or buffers) with them. Dynamic changes in pipeline is better but they also have a bunch of problems you need to solve. <div class="im"> > > I've also try to change sinks on-the-move (Playing) but it didn't work as I > expected. > > Any tips? </div>If I get it right what you're trying to do is to change the pipeline dynamically. Well, it's not the easiest part of work with GStreamer, I should say. There're several posts in the list about it here and there, but to sum everything гз here're the problems one need to solve to change the pipeline dynamically in proper way: 1. Branch synchronization if some of the sinks is in sync (e.g. streaming video to ximagesink and capturing it to file simultaneously): it's necessary to use queue for each branch. 2. To reconnect elements on the fly one need to look after the remaining pipeline. It's done by either blocking pads of changing branch or using valves (so dangerous). Besides that you should take into account that with every problem the pipeline is stalled hard without any messages even on DEBUG log level. It make the debugging difficult very much. Also these instructions work quite stable only for PLAYING state and have many issues for others. For example, if you block pads in PAUSED state, it will stall the pipeline forever as no buffers are streamed through the pipeline in this state. And finally, remember that elements are not guaranteed to be reusable i.e. if you create pipeline from scratch, set it to PLAYING state, then set it to READY and again to PLAYING, it's not guaranteed that the behavior is the same as if you create a new one instead of setting the existing pipeline to READY and then to PLAYING. So, there's some hope that it would be changed in the future releases, but now it's not easy at all to change the pipeline dynamically. Hope it helps. </blockquote></div>