<div class="gmail_quote">Hi all, I am writing an application for udp client to receive the rtp payloaded packets. The pipeline I use is on client and server is as below: ****************************************************************************************************************************** SERVER: gst-launch filesrc location=~/Desktop/h264-aac/<div>alien.mp4 ! qtdemux name=d \ d. ! queue ! rtph264pay ! udpsink port=1234 host=224.0.0.1 \ d. ! queue ! rtpmp4apay ! udpsink port=1233 host=224.0.0.1 CLIENT: gst-launch udpsrc uri=udp://<a href="http://224.0.0.1:1234/" target="_blank">224.0.0.1:1234</a> caps="application/x-rtp, media=(string)video, encoding-name=(string)H264, payload=(int)96" ! queue ! rtph264depay ! ffdec_h264 ! ffmpegcolorspace ! xvimagesink\ udpsrc uri=udp://<a href="http://224.0.0.1:1233/" target="_blank">224.0.0.1:1233</a> caps="application/x-rtp, media=(string)audio, clock-rate=(int)44100, encoding-name=(string)MP4A-LATM, payload=(int)96" ! queue ! rtpmp4adepay ! faad ! audioconvert ! alsasink ****************************************************************************************************************************** In my application I set the state of the pipeline to GST_STATE_PLAYING as below: =========================================================================== sres = gst_element_set_state (GST_ELEMENT (pipeline), GST_STATE_PLAYING); if (sres == GST_STATE_CHANGE_ASYNC) { gint timeout = 0; while (timeout < 5) { sres = gst_element_get_state (pipeline, &new_state, &pending_state, (1 * GST_SECOND)); g_print("GET state pipeline : new_state = %s pending_state = %s\n", gst_element_state_get_name (new_state), gst_element_state_get_name (pending_state)); timeout++; } } else { g_print ("Error changing pipeline state to PLAYING sres = %d\n", sres); return -1; } =========================================================================== </div> But the state changes only to PAUSED and never to PLAYING. Could someone suggest me what could be done to change the pipeline state to PLAYING. I had one more query about caps negotiation. How to dynamically set the caps on udpsrc element used on the CLIENT side? Thanks in advance. </div>