Hi Tiago, Thank you very much for your reply. I didn't "request" the recv_rtp_src_%d_%d_%d pad. In my codes, I used gst_element_link_many(gstrtpbin, rtpdec, vdec, vconv, vsink, NULL); and hope that I can get the "dynamically" created pad. But according to the error message, no such pad was created. Any idea? Thanks Regards, Qin <div class="gmail_quote">On Mon, Mar 1, 2010 at 7:20 AM, Tiago Katcipis <<a href="mailto:katcipis@inf.ufsc.br">katcipis@inf.ufsc.br</a>> wrote: <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">On Mon, Mar 1, 2010 at 1:24 AM, Qin Chen <<a href="mailto:eric.qin.chen@gmail.com" target="_blank">eric.qin.chen@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 experts, I am trying to write a pipeline for receiving and decoding H.264 RTP packets. Please see the C codes below. It is basically equivalent to following pipeline. <pre>gst-launch -v gstrtpbin name=rtpbin \ udpsrc caps="application/x-rtp,media=(string)video,clock-rate=(int)90000,encoding-name=(string)H264" \ port=5000 ! rtpbin.recv_rtp_sink_0 \ rtpbin. ! rtph264depay ! ffdec_h264 ! xvimagesink \ </pre> But I couldn't link gstrtpbin and rtph264depay. The error message is as follows: 0:00:00.135605335 5934 0x95aa008 INFO GST_ELEMENT_PADS gstutils.c:1587:gst_element_link_pads: trying to link element gst-rtp-bin:(any) to element rtp-decoder:(any) 0:00:00.135657988 5934 0x95aa008 INFO GST_ELEMENT_PADS gstelement.c:970:gst_element_get_static_pad: no such pad 'recv_rtp_src_%d_%d_%d' in element "gst-rtp-bin" 0:00:00.135679108 5934 0x95aa008 INFO GST_ELEMENT_PADS gstutils.c:1208:gst_element_get_compatible_pad:<gst-rtp-bin> Could not find a compatible pad to link to rtp-decoder:sink Could someone give me some hints? Why I have no "recv_rtp_src_%d_%d_%d"? </blockquote><div> </div></div><div><a href="http://www.gstreamer.net/data/doc/gstreamer/head/gst-plugins-good-plugins/html/gst-plugins-good-plugins-gstrtpbin.html" target="_blank">http://www.gstreamer.net/data/doc/gstreamer/head/gst-plugins-good-plugins/html/gst-plugins-good-plugins-gstrtpbin.html</a></div> <div> </div><div>as you can see the "recv_rtp_src_%d_%d_%d" pad is created dinamically, you cant get it.</div> <div> </div><div>"To use <a href="http://gst-plugins-good-plugins-gstrtpbin.html#GstRtpBin" style="text-decoration: none; color: rgb(52, 101, 164);" target="_blank">GstRtpBin</a> as an RTP receiver, request a recv_rtp_sink_%<code>d</code> pad. The session number must be specified in the pad name. Data received on the recv_rtp_sink_%<code>d</code> pad will be processed in the <a href="http://gst-plugins-good-plugins-gstrtpsession.html#GstRtpSession" style="text-decoration: none; color: rgb(52, 101, 164);" target="_blank">GstRtpSession</a> manager and after being validated forwarded on <a href="http://gst-plugins-good-plugins-gstrtpssrcdemux.html#GstRtpSsrcDemux" style="text-decoration: none; color: rgb(52, 101, 164);" target="_blank">GstRtpSsrcDemux</a> element. Each RTP stream is demuxed based on the SSRC and send to a <a href="http://gst-plugins-good-plugins-gstrtpjitterbuffer.html#GstRtpJitterBuffer" style="text-decoration: none; color: rgb(52, 101, 164);" target="_blank">GstRtpJitterBuffer</a>. After the packets are released from the jitterbuffer, they will be forwarded to a<a href="http://gst-plugins-good-plugins-gstrtpssrcdemux.html#GstRtpSsrcDemux" style="text-decoration: none; color: rgb(52, 101, 164);" target="_blank">GstRtpSsrcDemux</a> element. The <a href="http://gst-plugins-good-plugins-gstrtpssrcdemux.html#GstRtpSsrcDemux" style="text-decoration: none; color: rgb(52, 101, 164);" target="_blank">GstRtpSsrcDemux</a> element will demux the packets based on the payload type and will create a unique pad recv_rtp_src_%<code>d_</code>%<code>d_</code>%<code>d</code> on gstrtpbin with the session number, SSRC and payload type respectively as the pad name."</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;"><div><div></div><div class="h5">Or could someone lead me to similar examples? Thanks in advance! Regards, Qin static GstElement* construct_receiver_pipeline(void){ GstElement *pipeline, *gstrtpbin, *vdec, *rtpdec, *vsink; GstElement *jitterbuf, *vconv; GstElement *udpsrc_rtp; GstCaps *caps; GstPad *pad; gboolean err; GstPadLinkReturn res; //Create gstrtpbin gstrtpbin = gst_element_factory_make("gstrtpbin", "gst-rtp-bin"); if ( !gstrtpbin ) { g_printerr("Failed to create gstrtpbin\n"); return 0; } g_object_set(G_OBJECT (jitterbuf), "latency", jitter_latency, NULL); //RTP ource initialization udpsrc_rtp = gst_element_factory_make("udpsrc", "udp-udpsrc_rtp"); if ( !udpsrc_rtp ) { g_printerr("Failed to create udpsrc\n"); return 0; } g_object_set(G_OBJECT (udpsrc_rtp), "port", rtp_port, NULL); //gst_caps_new_simple and gst_element_linked_filter don't work g_object_set(G_OBJECT (udpsrc_rtp), "caps", gst_caps_from_string("application/x-rtp, " "clock-rate=(int)90000, " "payload=(int)96, " "media=(string)video, " "encoding-name=(string)H264"), NULL); //Create video decoder vdec = gst_element_factory_make(vdecoder, "video-decoder"); if ( !vdec ) { g_printerr("Failed to create %s\n", vdecoder); return 0; } //Choose RTP decoder according to video codec rtpdecoder = g_strdup(select_rtp_decoder(vdecoder)); g_free(vdecoder); //Create rtp decoder rtpdec = gst_element_factory_make(rtpdecoder, "rtp-decoder"); if ( !rtpdec ) { g_printerr("Failed to create %s\n", rtpdecoder); return 0; } //Create video converter vconv = gst_element_factory_make("ffmpegcolorspace", "video-converter"); if ( !vconv ) { g_printerr("Failed to create ffmpegcolorspace\n"); return 0; } //Create video sink vsink = gst_element_factory_make("xvimagesink", "video-sink"); if ( !vsink ) { g_printerr("Failed to create xvimagesink\n"); return 0; } /* Set up the pipeline */ gst_bin_add_many(GST_BIN (pipeline), udpsrc_rtp, gstrtpbin/*, jitterbuf*/, rtpdec, vdec, vconv, vsink, NULL); //link udpsrc_rtp to gstrtpbin pad = gst_element_get_request_pad(gstrtpbin, "recv_rtp_sink_%d"); if ( !pad ) { g_printerr("Failed to create pad\n"); return 0; } res = gst_pad_link(gst_element_get_pad(udpsrc_rtp, "src"), pad); gst_object_unref(GST_OBJECT (pad)); if ( GST_PAD_LINK_FAILED(res) ) { g_printerr("Failed to link pads\n"); return 0; } err = gst_element_link_many(gstrtpbin, rtpdec, vdec, vconv, vsink, NULL); if ( err==FALSE ) { g_printerr("Failed to link elements\n"); return 0; } return pipeline; } </div></div>------------------------------------------------------------------------------ Download Intel&#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. <a href="http://p.sf.net/sfu/intel-sw-dev" target="_blank">http://p.sf.net/sfu/intel-sw-dev</a> _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.sourceforge.net" target="_blank">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> ------------------------------------------------------------------------------ Download Intel&#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. <a href="http://p.sf.net/sfu/intel-sw-dev" target="_blank">http://p.sf.net/sfu/intel-sw-dev</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>