Hello Jaroslaw, The problem is that in case of streaming if sps & pps is lost no decoder can decode the H264 video, hence you getting the error "non-existing PPS referenced". To fix this please set config-interval property of rtph264pay , so that sps &pps are sent again and again. This will resolve your issue . Cheers Kapil <div class="gmail_quote">2011/3/10 Jarosław Przybyłowicz <<a href="mailto:jaroslaw.przybylowicz@mlabs.pl">jaroslaw.przybylowicz@mlabs.pl</a>> <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> Hi, I'm developing simple rtsp server and client. Simplified pipeline on the server side looks like: filesrc ! decodebin caps=video/x-h264 ! rtph264pay ! rtpbin (rtpbin is then connected to udpsinks for RTP, RTCP and udpsrc for RTCP). I used Totem to play the stream and everything looks to be working fine. Stream is played properly from start to end. However, I do have some problems with seek command. Lets say, one of the ten seek commands brakes down the player, sometimes it works, sometimes it doesn't. After calling gst_element_seek on the server side, there is a glitch in the player (followed by some artifacts in the rendered video) and then I get lots of "non-existing PPS referenced" on the debug console. Sadly it won't stabilize itself, it's broken for good until I restart the player. Secondly, I have implemented also a simple client, where pipeline is like this: rtpbin ! rtph264depay ! decodebin2 ! autovideosink This workd nicely for few first seconds. After that I again get lots of "non-existing PPS referenced" (no seek is performed!). Moreover, dump from rtph264depay to filesink produces exactly the same binary data as in the input file on the server side, so it is not a data corruption issue. I would be very happy if someone could explain to me what can cause "non-existing PPS referenced" because I don't even know where to start with this thing. Thanks in advance, Jaroslaw _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" target="_blank">http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> </blockquote></div> -- <a href="http://www.mediamagictechnologies.com">www.mediamagictechnologies.com</a> (Gstreamer, ffmpeg, Red5, Streaming) twitter handle: @gst_kaps <a href="http://www.linkedin.com/in/kapilagrawal">http://www.linkedin.com/in/kapilagrawal</a>