<div class="gmail_quote">Hi all, I am writing an application for UDP multicast server. I use the below pipelines for server & client. SERVER: gst-launch filesrc location=~/Desktop/h264-aac/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 The pipeline works fine. But when I am writing an application for the above pipeline the pipeline doesn't change its state to "PLAYING". I state change on the pipeline is "GST_STATE_CHANGE_ASYNC". The pipeline never changes its state to "PLAYING". But when if I change my application to send either video or audio packets alone the application works fine with proper state changes. I will be thankful for any help. </div>