<html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body> Hello All, I am trying to record audio received in form srtp in a custom application. For this I set up following pipeline programatically: udpsrc port=5906 caps="application/x-srtp,channels=(int)1,media=(string)audio,payload=(int)0,clock-rate=(int)8000,encoding-name=(string)PCMU,ssrc=(uint)0,srtp-key=(buffer)344d2b7943556a5679644c53724d7232314478784a766e7075674446717172414639736c52717467,srtp-cipher=(string)aes-128-icm,srtp-auth=(string)hmac-sha1-32,srtcp-cipher=(string)aes-128-icm,srtcp-auth=(string)hmac-sha1-32,roc=(uint)0" ! srtpdec ! rtppcmudepay ! filesink location=/home/audio.pcmu The ssrc is not received in sdp. I have implemented the callback function to return capstring as mentioned in the <a moz-do-not-send="true" href="https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-bad/html/gst-plugins-bad-plugins-srtpdec.html">documentation</a> : static GstCaps request_key_callback (GstElement gstsrtpdec, guint ssrc, gpointer udata) The capstring returned is like: " application/x-srtp,channels=(int)1,media=(string)audio,payload=(int)0,clock-rate=(int)8000,encoding-name=(string)PCMU,ssrc=(uint)1932929554,srtp-key=(buffer)4d73554e564e334354466141365042324168614444436c4a456a754a497673747a354e5961694d5a,srtp-cipher=(string)aes-128-icm,srtp-auth=(string)hmac-sha1-32,srtcp-cipher=(string)aes-128-icm,srtcp-auth=(string)hmac-sha1-32,roc=(uint)0 " But after the callback invokes I am receiving following error: (recorder:32537): GLib-GObject-CRITICAL **: 14:18:06.064: g_object_unref: assertion 'G_IS_OBJECT (object)' failed ** (recorder:32537): CRITICAL **: 14:18:06.064: update_session_stream_from_caps: assertion 'GST_IS_SRTP_DEC (filter)' failed and the app crashes. Can anyone tell me what mistake I am making. I am not able to find much in the documentation or any examples. Thanks & Regards. </body> </html>