<div> hi all     i have a trouble when i use gstreamer to develop a small project for sending and receiving udp packets with rtp payloaded sender------->server|---------------->receiver_1                                    |--------------->receiver_2 ***************************************************************** sender: gst-launch -v gstrtpbin name=rtpbin \ filesrc location=filesrc location=/home/xuxin/desktop/g_p/a.avi ! decodebin name=dec \ dec. ! queue ! x264enc byte-stream=false ! rtph264pay ! rtpbin.send_rtp_sink_0 \ rtpbin.send_rtp_src_0 ! udpsink port=5000 host=172.21.29.177 name=vrtpsink \ dec. ! queue ! audioresample ! audioconvert ! alawenc ! rtppcmapay ! rtpbin.send_rtp_sink_1 \ rtpbin.send_rtp_src_1 ! udpsink port=5002 host=172.21.29.177 ts-offset=0 name=artpsink Server( ip:172.21.29.177) gst-launch -v gstrtpbin name=rtpbin latency=200 \ udpsrc caps="application/x-rtp,media=(string)video,clock-rate=(int)90000,encoding-name=(string)H264" port=5000 ! rtpbin.recv_rtp_sink_0 \ rtpbin. ! udpsink port=5000 host=224.0.0.1 sync=false ts-offset=0 \ udpsrc caps="application/x-rtp,media=(string)audio,clock-rate=(int)8000,encoding-name=(string)PCMA" port=5002 ! rtpbin.recv_rtp_sink_1 \ rtpbin. ! udpsink port=5002 host=224.0.0.1 sync=false ts-offset=0 receiver (in multigroup) gst-launch -v gstrtpbin name=rtpbin latency=200 \ udpsrc multigroup="224.0.0.1" caps="application/x-rtp,media=(string)video,clock-rate=(int)90000,encoding-name=(string)H264" port=5000 ! rtpbin.recv_rtp_sink_0 \ rtpbin. ! rtph264depay ! decodebin ! xvimagesink \ udpsrc multigroup="224.0.0.1" caps="application/x-rtp,media=(string)audio,clock-rate=(int)8000,encoding-name=(string)PCMA" port=5002 ! rtpbin.recv_rtp_sink_1 \ rtpbin. ! rtppcmadepay ! decodebin ! audioconvert ! audioresample ! alsasink **********************************************************************  then I write "Server" in C language ,the code is showed below #include <gst/gst.h> #include <glib.h> #include <unistd.h> #include <stdlib.h> static gboolean bus_call (GstBus     *bus,           GstMessage *msg,           gpointer    data) {   GMainLoop *loop = (GMainLoop *) data;   switch (GST_MESSAGE_TYPE (msg)) {     case GST_MESSAGE_EOS:       g_print ("End of stream\n");       g_main_loop_quit (loop);       break;     case GST_MESSAGE_ERROR: {       gchar *debug;       GError *error;       gst_message_parse_error (msg, &error, &debug);       g_free (debug);       g_printerr ("Error: %s\n", error->message);       g_error_free (error);       g_main_loop_quit (loop);       break;     }     default:       break;   }   return TRUE; } static void on_pad_added(GstElement *element, GstPad *pad, gpointer data) {     GstPad *sinkpad;     GstElement *udpsink = (GstElement *)data;         g_print("Dynamic pad created, linking demuxer/decoder\n");     sinkpad = gst_element_get_static_pad(udpsink, "sink");     gst_pad_link(pad, sinkpad);     gst_object_unref(sinkpad); } int main(int argc, char **argv) {     GMainLoop *loop;     GstBus *bus;     GstPad *pad;     GstCaps *videocap, *audiocap;     GstElement *pipeline, *gstrtpbin, *udpsrc1, *udpsrc2,         *udpsink1, *udpsink2;         gst_init(&argc, &argv);     loop = g_main_loop_new(NULL, FALSE);         pipeline = gst_pipeline_new("server");     gstrtpbin = gst_element_factory_make("gstrtpbin", "gst_rtpbin");     udpsrc1 = gst_element_factory_make("udpsrc", "udpsrc1");     udpsrc2 = gst_element_factory_make("udpsrc", "udpsrc2");     udpsink1 = gst_element_factory_make("udpsink", "udpsink1");     udpsink2 = gst_element_factory_make("udpsink", "udpsink2");         if (argc != 4) {         g_printerr("argument error");         return -1;     }         bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline));     gst_bus_add_watch(bus, bus_call, loop);     gst_object_unref(bus);         videocap = gst_caps_new_simple("application/x-rtp",         "media", G_TYPE_STRING, "video",         "clock-rate", G_TYPE_LONG, 90000,         "encoding-name", G_TYPE_STRING, "H264", NULL);             audiocap = gst_caps_new_simple("application/x-rtp",         "media", G_TYPE_STRING, "audio",         "clock-rate", G_TYPE_LONG, 8000,         "encoding-name", G_TYPE_STRING, "PCMA", NULL);         g_object_set(G_OBJECT(udpsrc1), "caps", videocap, NULL);     g_object_set(G_OBJECT(udpsrc2), "caps", audiocap, NULL);     g_object_set(G_OBJECT(udpsrc1), "port", (gint)atoi(argv[1]), NULL);     g_object_set(G_OBJECT(udpsrc2), "port", (gint)atoi(argv[2]), NULL);     g_object_set(G_OBJECT(udpsink1), "port", (gint)atoi(argv[1]), NULL);     g_object_set(G_OBJECT(udpsink2), "port", (gint)atoi(argv[2]), NULL);     g_object_set(G_OBJECT(udpsink1), "host", argv[3], NULL);     g_object_set(G_OBJECT(udpsink2), "host", argv[3], NULL);         gst_caps_unref(videocap);     gst_caps_unref(audiocap);             gst_bin_add_many(GST_BIN(pipeline), udpsrc1, udpsrc2, gstrtpbin, udpsink1, udpsink2, NULL);         pad = gst_element_get_request_pad(gstrtpbin, "recv_rtp_sink_0");     gst_pad_link(gst_element_get_pad(udpsrc1, "src"), pad);         pad = gst_element_get_request_pad(gstrtpbin, "recv_rtp_sink_1");     gst_pad_link(gst_element_get_pad(udpsrc2, "src"), pad);         g_signal_connect(gstrtpbin, "pad-added", G_CALLBACK(on_pad_added), udpsink1);     g_signal_connect(gstrtpbin, "pad_added", G_CALLBACK(on_pad_added), udpsink2);         gst_element_set_state(pipeline, GST_STATE_PLAYING);         g_print("Running...\n");     g_main_loop_run(loop);         /* Out of the main loop, clean up nicely */     g_print("Returned, stopping playback\n");     gst_element_set_state(pipeline, GST_STATE_NULL);         g_print("Deleting pipeline\n");     gst_object_unref(GST_OBJECT(pipeline));         return 0; } ********************************************************************* when i run the server writed in c on my computer , Error: internal data flow error when i run the server which is not writed in c , Error : internal streamer error clock problem. additional debug info: gstbin.c(2240):gst_bin_do_latency_func() : failed to configure latency of 0:00:00:00000000   can anybody help me ,thank you very much </div>  <hr/> <a href="http://512.mail.163.com/mailstamp/stamp/dz/activity.do?from=footer">穿越地震带纪念汶川地震一周年</a>