Hi, Thx a lot for the explanation. It resolved my problem, I can change the physical input (s-video, composite, ...) now. Sincerely, Julien <div>2008/4/13, Stefan Kost <<a href="mailto:ensonic@hora-obscura.de">ensonic@hora-obscura.de</a>>:<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> hi julien, Julien Isorce schrieb: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> Hi, I am trying to select physical input (S-Video, Composite, ...) The following code : ------------ ... videodevicesrc = gst_element_factory_make("v4l2src", "videodevicesrc"); ... GstTuner *tuner = GST_TUNER (videodevicesrc); ... ------------ leads to: (<unknown>:17146): GStreamer-CRITICAL **: gst_implements_interface_cast: assertion `gst_element_implements_interface (GST_ELEMENT (from), iface_type)' failed </blockquote> You can only cast in PAUSED or PLAYING (not sure about READY). Basically the devices has to be opened first, before the element knows that the underlying hardware has support for tuner. The gst_implements_interface mechanism is basically a hack to conditinally implement interfaces. Stefan <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> I know that v4l2src implements this interface and I got code example from <a href="http://webcvs.freedesktop.org/gstreamer/gst-plugins-good/tests/icles/v4l2src-test.c?revision=1.1&view=markup" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">http://webcvs.freedesktop.org/gstreamer/gst-plugins-good/tests/icles/v4l2src-test.c?revision=1.1&view=markup</a> <<a href="http://webcvs.freedesktop.org/gstreamer/gst-plugins-good/tests/icles/v4l2src-test.c?revision=1.1&view=markup" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">http://webcvs.freedesktop.org/gstreamer/gst-plugins-good/tests/icles/v4l2src-test.c?revision=1.1&view=markup</a>> The installed packages is gstreamer0.10-plugins-good_0.10.6-0ubuntu4_i386.deb The following command lien works very fine : gst-launch-0.10 v4l2src ! xvimagesink Where am I wrong ? Sincerely Julien ------------------------------------------------------------------------ ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. <a href="http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone</a> ------------------------------------------------------------------------ _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.sourceforge.net" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">gstreamer-devel@lists.sourceforge.net</a> <a href="https://lists.sourceforge.net/lists/listinfo/gstreamer-devel" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">https://lists.sourceforge.net/lists/listinfo/gstreamer-devel</a> </blockquote> </blockquote></div>