Thanks for your efforts, I submitted the bug here: <a href="https://bugzilla.gnome.org/show_bug.cgi?id=683580">https://bugzilla.gnome.org/show_bug.cgi?id=683580</a> <div class="gmail_quote">On Fri, Sep 7, 2012 at 3:03 PM, José Alburquerque <<a href="mailto:jaalburquerque@cox.net" target="_blank">jaalburquerque@cox.net</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="im">On Fri, 2012-09-07 at 07:20 +0300, Jiergir Ogoerg wrote: > Thanks, > your cast works! > > The code I'm talking about which doesn't compile is at the bottom > of this screenshot: > <a href="http://f35f22fan.blogspot.com/2012/09/gstreamer.html" target="_blank">http://f35f22fan.blogspot.com/2012/09/gstreamer.html</a> > > As one can see > 1) The guy who wrote it calls "parse()" on a Gst::Query object > 2) He uses "." to refer to the "parse()" method instead of "->" > So clearly it wouldn't compile, so I didn't even try. </div>Ah, that's a beginner's attempt at a crude C++ translation of the usage example found in GstQuery's description section. It was placed in the Gst::Query class docs as an attempt to also show how the class could be used. I guess little thought was put into the need to cast correctly before using the parse() method as you describe. The line which should cast has been fixed in this commit: <a href="http://git.gnome.org/browse/gstreamermm/commit/?id=a6933d2012fbe626eb110320ab6c4338c583e7bc" target="_blank">http://git.gnome.org/browse/gstreamermm/commit/?id=a6933d2012fbe626eb110320ab6c4338c583e7bc</a> Please feel free to report any errors you find here: <a href="https://bugzilla.gnome.org/enter_bug.cgi?product=gstreamermm" target="_blank">https://bugzilla.gnome.org/enter_bug.cgi?product=gstreamermm</a> <div class="im"> > > I wish that create() method just returned > Glib::RefPtr<Gst::QueryDuration> > </div>Feel free to file a bug about that also. <div class="HOEnZb"><div class="h5"> > > On Thu, Sep 6, 2012 at 10:50 PM, José Alburquerque > <<a href="mailto:jaalburquerque@cox.net">jaalburquerque@cox.net</a>> wrote: > On Thu, 2012-09-06 at 19:14 +0300, Jiergir Ogoerg wrote: > > Hi, > > I'm using the C++ backend of gstreamer (0.10) > > > > The problem is that Gst::QueryDuration::create(Format > format) returns > > Glib::RefPtr<Gst::Query> instead of > Glib::RefPtr<Gst::QueryDuration> > > which makes it impossible to use the parse() method of the > returned > > object since parse() only exists in Gst::QueryDuration. > > > The create() methods of the Gst::Query* classes wrap the > gst_query_new_*() functions and they return a GstQuery so the > create() > methods similarly return a Gst::Query. > > > > As a workaround I thought I'd cast the returned value to > > Glib::RefPtr<Gst::QueryDuration> but the compiler refuses to > do so. > > > The proper way to cast it would be something like: > > Glib::RefPtr<Gst::QueryDuration> durQuery = > Glib::RefPtr<Gst::QueryDuration>::cast_dynamic(query); > > The ogg_player, ogg_player_gtkmm and the media_player_gtkmm > examples > show how this is done when querying the pipeline for the > position of the > stream. > > > > Using Ubuntu 12.04 amd64, the documentation > (libgstreamermm-0.10-doc) > > doesn't tell how to do it. > > > > However, in Ubuntu 12.10 (yet to be released), the > documentation is > > updated with an example but it doesn't compile because the > example > > calls parse() on a Gst::Query object which doesn't have such > a method. > > > Really? What example would that be? The gstreamermm examples > should > compile and work fine with gstreamermm. > > > > So how do I create a Gst::QueryDuration object to be able to > call > > parse() to get the duration? Is it a broken C++ bindings > design? > > > _______________________________________________ > > gstreamer-devel mailing list > > <a href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a> > > > <a href="http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" target="_blank">http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> > > -- > José > > _______________________________________________ > gstreamer-devel mailing list > <a href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a> > <a href="http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" target="_blank">http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> > > _______________________________________________ > gstreamer-devel mailing list > <a href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a> > <a href="http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" target="_blank">http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> -- José _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" target="_blank">http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> </div></div></blockquote></div>