Hi, I'm developing a gst-app with MFC: I'm currently trying to show an mpeg4 stream with gst. I'm using the windows gst one from <a href="http://perso.orange.es/moutte983/gstreamer/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)"> http://perso.orange.es/moutte983/gstreamer/ </a>. My goal is to use a fakesrc in which getting mpeg4 packet (done) and show with gst the video but I get this message: "ffdec_mpeg4:input format was not set before data start ". Here's my gst core: ..... GstElement *pipeline, *fakesrc, *flt, *conv, *videosink,*decoder,*videoscale,*par;     GstBus* bus;     GMainLoop *loop;     /* init GStreamer */     gst_init (NULL,NULL);     loop = g_main_loop_new (NULL, FALSE);     pipeline = gst_pipeline_new ("pipeline");     fakesrc = gst_element_factory_make ("fakesrc", "source");     decoder = gst_element_factory_make ("ffdec_mpeg4","mpeg4-decoder");     videoscale = gst_element_factory_make ("videoscale", "scaling-video");     par = gst_element_factory_make ("capsfilter", "dimens");     g_object_set (G_OBJECT(par), "caps",       gst_caps_new_simple( "video/x-raw-yuv",         "width", G_TYPE_INT, 720,         "height", G_TYPE_INT, 576,NULL),       NULL );     conv = gst_element_factory_make ("ffmpegcolorspace", "converter");     videosink = gst_element_factory_make ("directdrawsink", "directdraw");     if (!pipeline || !fakesrc || !decoder || !videoscale || !par || !conv || !videosink) {         g_print ("One element could not be created\n");         return -1;     }     /* put all elements in a bin */     gst_bin_add_many (GST_BIN (pipeline),             fakesrc, decoder,videoscale ,par, conv, videosink, NULL);     /* link together */     gst_element_link_many (fakesrc,decoder,videoscale, par, conv, videosink, NULL);     bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));     gst_bus_add_watch (bus, bus_call, loop);     gst_object_unref (bus);     g_object_set (G_OBJECT (fakesrc),         "signal-handoffs", TRUE,         "sizemax", 720 * 288 * 2,         "sizetype", 2, NULL);     g_signal_connect (fakesrc, "handoff", G_CALLBACK (cb_handoff), pParam);         /* Now set to playing and iterate. */     gst_element_set_state (pipeline, GST_STATE_PLAYING);     g_main_loop_run (loop);     /* clean up nicely */     gst_element_set_state (pipeline, GST_STATE_NULL);     gst_object_unref (GST_OBJECT (pipeline));     return 0; } ... The mpeg4 stream is via tcp but I can't use tcp plugin with gstwin32 (I can't find it!), so I must use the callback. Thank's. -- Riccardo Corona