Hi Yue, Please check the answers below. I have tried my best to give the answers, but apologies for any wrong arguments.. :) <div class="gmail_quote">On Wed, Feb 27, 2008 at 12:13 PM, Yue Li <<a href="mailto:liyue99@gmail.com">liyue99@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi, I'm new to Gstreamer and this mail list. So I know maybe my question is too stupid. But I really couldn't find the answer and need your help. I just tried to decode a mpeg file like below: gst-launch filesrc location=mpeg2.mpg ! mpegdemux name=demux video_00! { queue ! mpeg2dec ! xvideosink } but got the error message : WARNING: erroneous pipeline: no element "video_00"</blockquote><div>The currect pipeline for this should be : gst-launch filesrc location=mpeg2.mpg ! mpegdemux name=demux { demux.video_00 ! queue ! mpeg2dec ! xvideosink } as the demuxer is a parent of the video_00 pad.  </div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Then I tried: gst-launch filesrc location=mpeg2.mpg ! mpegdemux ! fakesink and got: Setting pipeline to PAUSED ... Pipeline is PREROLLING ... ERROR: from element /pipeline0/filesrc0: Internal data flow error. Additional debug info: gstbasesrc.c(2099): gst_base_src_loop (): /pipeline0/filesrc0: streaming task paused, reason not-linked (-1) ERROR: pipeline doesn't want to preroll. Setting pipeline to NULL ... FREEING pipeline ... </blockquote><div>I am not very much sure of this, as this should have worked fine. Please try giving the caps filter ( not a good practice.) before mpeg2demux. Hope this will help you....... </div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> I know this question may be too simple to you but please help me... Thank you! Yue Li ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. <a href="http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/" target="_blank">http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/</a> _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.sourceforge.net">gstreamer-devel@lists.sourceforge.net</a> <a href="https://lists.sourceforge.net/lists/listinfo/gstreamer-devel" target="_blank">https://lists.sourceforge.net/lists/listinfo/gstreamer-devel</a> </blockquote></div> -- Manish Rana Software Engg. Handset Technology Solution, Sasken Comm. Tech. Bangalore,India