Hi I a beginner with GStreamer, I am clueless about of the behavior and role of some GStreamer elements. I wrote a pipeline to get transition effect between 2 avi videos, it works fine but the sond, there's no sound at all. I was told to put an avidemuxer, I've been working around with it without luck. I put it between the queue and the gnlcomposition,it doesn't work, then I put after the queue. I wonder if some decoder is missing. I tryed to adapt my pipeline to this one: <a href="http://lists.freedesktop.org/archives/gstreamer-devel/2008-October/019240.html" target="_blank">http://lists.freedesktop.org/archives/gstreamer-devel/2008-October/019240.html</a>, but any adaptation didn't work for me. I got many kind of errors: "GStreamer-CRITICAL **: gst_pad_link_full: assertion `GST_IS_PAD (sinkpad)' failed" or Segment Violation Thanks a lot, Rossana This is the pipeline I need to adapt to hear the sound: <pre>bin ----------------------------------------------------------------------------------------------- alpha -------------------- |----------videomixer ------------fmpegcolorspace smptealpha --------------- ^ | ----------------------------------------------------------------------------------------------- | Controller // it controls the start-duration property of smptealpha composition -------------------------------------------------------------------------------------------------------- gnlfilesource | |gnloperation| // contains the *bin* described above | gnlfilesource -------------------------------------------------------------------------------------------------------- gnlopetation contains the *bin* described above gnlfilesource, one for each video pipeline ____________________ | | composition operation |___________ queue ___________ sink ___________________ | </pre>