<div dir="ltr">I think tsdemux is badly broken at the moment. I'm having a similar experience to you: sometimes it works, then you change something that should be completely irrelevant (in your case constructing the pipeline in C++ instead of using gst-launch; in my case I've found that just changing the log level can make a difference) and the pipeline freezes. See also <a href="https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/issues/1419">issue 1419</a>.<div> </div><div>I've just tried adding a queue2 to my manager element where its sink is linked with my internal source (has a single src pad with caps "video/mpegts, systemstream = (boolean) true;") and the queue2's src is the target of my manager's src ghost pad. This made things worse. Highlights from the log of `gst-launch-1.0 playbin uri="htsp://..."`:</div><div> </div><div>0:00:00.088988232 24066 0x5591eb207ea0 INFO GST_ELEMENT_FACTORY gstelementfactory.c:363:gst_element_factory_create: creating element "tsdemux" 0:00:00.089118072 24066 0x5591eb207ea0 INFO GST_ELEMENT_PADS gstelement.c:752:gst_element_add_pad:<MpegTSBase@0x7fac2c1d8000> adding pad 'sink' 0:00:00.089291804 24066 0x5591eb207ea0 INFO GST_PADS gstpad.c:2377:gst_pad_link_prepare: trying to link typefind:src and tsdemux0:sink 0:00:00.089306656 24066 0x5591eb207ea0 INFO GST_PADS gstpad.c:2585:gst_pad_link_full: linked typefind:src and tsdemux0:sink, successful 0:00:00.089310744 24066 0x5591eb207ea0 INFO GST_EVENT gstevent.c:1610:gst_event_new_reconfigure: creating reconfigure event 0:00:00.089334061 24066 0x5591eb207ea0 INFO GST_STATES gstelement.c:2769:gst_element_continue_state:<tsdemux0> completed state change to READY 0:00:00.089340768 24066 0x5591eb207ea0 INFO GST_STATES gstelement.c:2669:_priv_gst_element_state_changed:<tsdemux0> notifying about state-changed NULL to READY (VOID_PENDING pending) 0:00:00.089424733 24066 0x5591eb207ea0 INFO GST_ELEMENT_PADS gstelement.c:1006:gst_element_get_static_pad: no such pad 'video_%01x_%05x' in element "tsdemux0" 0:00:00.089433342 24066 0x5591eb207ea0 INFO GST_ELEMENT_PADS gstelement.c:1006:gst_element_get_static_pad: no such pad 'audio_%01x_%05x' in element "tsdemux0" 0:00:00.089437649 24066 0x5591eb207ea0 INFO GST_ELEMENT_PADS gstelement.c:1006:gst_element_get_static_pad: no such pad 'subpicture_%01x_%05x' in element "tsdemux0" 0:00:00.089441946 24066 0x5591eb207ea0 INFO GST_ELEMENT_PADS gstelement.c:1006:gst_element_get_static_pad: no such pad 'private_%01x_%05x' in element "tsdemux0" 0:00:00.089528559 24066 0x5591eb207ea0 WARN task gsttask.c:890:gst_task_join:<srcqueue:src> trying to join task from its thread (gst-launch-1.0:24066): GStreamer-WARNING **: 15:40:38.404: Trying to join task 0x5591eb225170 from its thread would deadlock. You cannot change the state of an element from its streaming thread. Use g_idle_add() or post a GstMessage on the bus to schedule the state change from the main thread.</div><div> </div><div>I think I'm going to have to give up on gstreamer and try to get my head around something like MSE in a web app :-(.</div><div> </div></div> <div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, 6 Oct 2020 at 12:30, Torben <<a href="mailto:t.wiggerich@airrobot.de">t.wiggerich@airrobot.de</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi all, I have a problem to get the srcipt running in my application. So at first I tried to compile the following: gst-launch-1.0 -v udpsrc multicast-group=224.10.10.10 port=8008 ! tsdemux ! h264parse ! avdec_h264 ! d3dvideosink sync=false It worked and displays the correct video. But if I try to do this in my application than happens nothing. I think the problem is that the event linkElements does not get called. So it comes from the pad-added signal of the tsdemux. I do not get any errors, or at least I cannot see them. So it seems for me that everything is ok. But the signal is not getting called... I run the following code with GST_DEBUG level 4. gstdebug(4).txt <<a href="http://gstreamer-devel.966125.n4.nabble.com/file/t379676/gstdebug%284%29.txt" rel="noreferrer" target="_blank">http://gstreamer-devel.966125.n4.nabble.com/file/t379676/gstdebug%284%29.txt</a>> Can you please tell me what I am doing wrong? #include <QCoreApplication> #include <gst/gst.h> #include <iostream> typedef struct { GstElement * pipeline = nullptr; GstElement * source = nullptr; GstElement * tsDemux = nullptr; GstElement * h264parse = nullptr; GstElement * avdecH264 = nullptr; GstElement * sinkVideo = nullptr; } VideoData; static void linkElements(GstElement* element,GstPad* sourcePad, gpointer sinkElement); int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); GMainLoop *loop; if (!g_thread_supported ()) g_thread_init (nullptr); gst_init ( 0, 0 ); loop = g_main_loop_new (nullptr, FALSE); VideoData m_data; m_data.pipeline = gst_pipeline_new ("player"); m_data.source = gst_element_factory_make ("udpsrc", nullptr); m_data.tsDemux = gst_element_factory_make("tsdemux", nullptr); m_data.h264parse = gst_element_factory_make("h264parse", nullptr); m_data.avdecH264 = gst_element_factory_make("avdec_h264", nullptr); m_data.sinkVideo = gst_element_factory_make("d3dvideosink", nullptr); g_object_set(G_OBJECT (m_data.source), "multicast-group", "224.10.10.10", nullptr); g_object_set(G_OBJECT (m_data.source), "port", 8008, nullptr); g_object_set(G_OBJECT (m_data.sinkVideo), "sync", false, nullptr); gst_bin_add_many(GST_BIN(m_data.pipeline), m_data.source, m_data.tsDemux, m_data.h264parse, m_data.avdecH264, m_data.sinkVideo, nullptr); std::cout << "Start linking all elements..." << std::endl; if ( gst_element_link (m_data.source, m_data.tsDemux ) != TRUE ) { std::cout << "1: Element could not be linked." << std::endl; gst_object_unref (m_data.pipeline); return 0; } g_signal_connect(m_data.tsDemux, "pad-added", G_CALLBACK(linkElements), nullptr); //nullptr //&m_data if ( gst_element_link_many(m_data.h264parse, m_data.avdecH264, m_data.sinkVideo, nullptr) != TRUE ) { std::cout << "2: Element could not be linked." << std::endl; gst_object_unref (m_data.pipeline); return 0; } std::cout << "Linked all elements!" << std::endl; GstStateChangeReturn ret = gst_element_set_state(m_data.sinkVideo, GST_STATE_READY); ret = gst_element_set_state (m_data.pipeline, GST_STATE_PLAYING); if (ret == GST_STATE_CHANGE_FAILURE) { std::cout << "Unable to set the pipeline to the playing state." << std::endl; gst_object_unref (m_data.pipeline); return 0; } g_main_loop_run (loop); return a.exec(); } static void linkElements(GstElement* element,GstPad* sourcePad, gpointer sinkElement){ std::cout << "Got here linkElements!" << std::endl; // It will never get here! GstPad* sinkPad=gst_element_get_static_pad((GstElement*)sinkElement,"sink"); gst_pad_link(sourcePad,sinkPad); gst_object_unref(sinkPad); } -- Sent from: <a href="http://gstreamer-devel.966125.n4.nabble.com/" rel="noreferrer" target="_blank">http://gstreamer-devel.966125.n4.nabble.com/</a> _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.freedesktop.org" target="_blank">gstreamer-devel@lists.freedesktop.org</a> <a href="https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" rel="noreferrer" target="_blank">https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> </blockquote></div> <div> </div>-- <div dir="ltr" class="gmail_signature"><div dir="ltr">TH<div> </div></div></div>