Thank you all for the suggestions. I have tested both approaches. <br><br>1. Use gdk_display_sync (gdk_display_get_default())<br><br>Application A (which has the window) is written using QT. Here is the procedure:<br><br>1). Application A calls uiWindow.show() to display window,<br> 2). Call gdk_display_sync (gdk_display_get_default()) right after show(),<br>3). Get windowId, and send to Application B,<br>4). Application B call gst_x_overlay_set_xwindow_id(GST_X_OVERLAY(m_sinkPreview), windowId);<br> <br>With or without step 2), Application B can crash.<br><br>2. Use gdk_threads_enter and gdk_threads_leave<br><br>I did as suggested by Matthews and Luciana, in application B. This works.<br><br>Thanks again,<br>Yiliang<br> <br><div class="gmail_quote">On Tue, Mar 2, 2010 at 12:28 PM, Tristan Matthews <span dir="ltr"><<a href="mailto:tristan@sat.qc.ca">tristan@sat.qc.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> <div class="gmail_quote">2010/3/2 Tristan Matthews <span dir="ltr"><<a href="mailto:tristan@sat.qc.ca" target="_blank">tristan@sat.qc.ca</a>></span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> <div class="gmail_quote"><div class="im">2010/3/2 Jan Schmidt <span dir="ltr"><<a href="mailto:thaytan@noraisin.net" target="_blank">thaytan@noraisin.net</a>></span></div><div class="im"><div>Here's my code:<br> </div><div><br>bool handleBusMsg(GstMessage *message)<br> {<br> if (!gst_structure_has_name(message->structure, "prepare-xwindow-id"))<br> return false;<br><br> gdk_threads_enter();<br> gst_x_overlay_set_xwindow_id(GST_X_OVERLAY(GST_MESSAGE_SRC(message)), getXWindow());<br> gdk_threads_leave();<br>}<br><br></div></div></div></blockquote><div><br>I should add, getXWindow() returns the xid which has been provided by Application A (the destination), and that this code lives in Application B (the source).<br> <br> </div><div><div></div><div class="h5"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="gmail_quote"><div> Thanks,<br><font color="#888888"> Tristan<br> <br></font></div> <div><div></div><div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> - Jan.<br> <div><br> On Sat, 2010-02-27 at 17:23 -0800, yiliang wrote:<br> </div><div>> Hi,<br> ><br> > I have 2 applications. One application (application A) creates a window, and<br> > sends the window ID to another application (application B). application B<br> > has a gstreamer video pipeline that uses xvimagesink to display the video as<br> > overlay in the window using the window ID provided by application A. I am<br> > sorry if it sounds a little confusing. This is to separate UI from pipeline.<br> ><br> > Following function is used to configure xvimagesink with window ID:<br> ><br> > gst_x_overlay_set_xwindow_id(GST_X_OVERLAY(xvimagesink), winId);<br> ><br> > Most of time it works fine, but sometimes I encounter the following problem,<br> > and the application B is terminated:<br> ><br> > X Error of failed request: BadWindow (invalid Window parameter)<br> > Major opcode of failed request: 3 (X_GetWindowAttributes)<br> > Resource id in failed request: 0x400016f<br> > Serial number of failed request: 32<br> > Current serial number in output stream: 33<br> ><br> > After some debugging, I found the error was generated in function<br> > gst_xvimagesink_set_xwindow_id() when it called the following function:<br> ><br> > XGetWindowAttributes<br> ><br> > Could anyone give some hint how to fix this problem?<br> ><br> > Thanks,<br> > Yiliang<br> ><br> <br> <br> --<br> </div><font color="#888888">Jan Schmidt <<a href="mailto:thaytan@noraisin.net" target="_blank">thaytan@noraisin.net</a>><br> </font><div><div></div><div><br> <br> ------------------------------------------------------------------------------<br> Download Intel&#174; Parallel Studio Eval<br> Try the new software tools for yourself. Speed compiling, find bugs<br> proactively, and fine-tune applications for parallel performance.<br> See why Intel Parallel Studio got high marks during beta.<br> <a href="http://p.sf.net/sfu/intel-sw-dev" target="_blank">http://p.sf.net/sfu/intel-sw-dev</a><br> _______________________________________________<br> gstreamer-devel mailing list<br> <a href="mailto:gstreamer-devel@lists.sourceforge.net" target="_blank">gstreamer-devel@lists.sourceforge.net</a><br> <a href="https://lists.sourceforge.net/lists/listinfo/gstreamer-devel" target="_blank">https://lists.sourceforge.net/lists/listinfo/gstreamer-devel</a><br> </div></div></blockquote></div></div></div><br><br clear="all"><div><div></div><div><br>-- <br>Tristan Matthews<br>email: <a href="mailto:tristan@sat.qc.ca" target="_blank">tristan@sat.qc.ca</a><br>web: <a href="http://tristanswork.blogspot.com" target="_blank">http://tristanswork.blogspot.com</a><br> </div></div></blockquote></div></div></div><div><div></div><div class="h5"><br><br clear="all"><br>-- <br>Tristan Matthews<br>email: <a href="mailto:tristan@sat.qc.ca" target="_blank">tristan@sat.qc.ca</a><br>web: <a href="http://tristanswork.blogspot.com" target="_blank">http://tristanswork.blogspot.com</a><br> </div></div><br>------------------------------------------------------------------------------<br> Download Intel&#174; Parallel Studio Eval<br> Try the new software tools for yourself. Speed compiling, find bugs<br> proactively, and fine-tune applications for parallel performance.<br> See why Intel Parallel Studio got high marks during beta.<br> <a href="http://p.sf.net/sfu/intel-sw-dev" target="_blank">http://p.sf.net/sfu/intel-sw-dev</a><br>_______________________________________________<br> gstreamer-devel mailing list<br> <a href="mailto:gstreamer-devel@lists.sourceforge.net">gstreamer-devel@lists.sourceforge.net</a><br> <a href="https://lists.sourceforge.net/lists/listinfo/gstreamer-devel" target="_blank">https://lists.sourceforge.net/lists/listinfo/gstreamer-devel</a><br> <br></blockquote></div><br>