Hi, Since sometimes the client needs the key frame. So I call the event publish in another thread. The code like this: RegisterThread(); pjsua_call * call = &pjsua_var.calls[id]; if(call!=NULL) { pjmedia_event event; pjmedia_event_init(&event,PJMEDIA_EVENT_KEYFRAME_MISSING,NULL,NULL); status = pjmedia_event_publish(NULL,call,&event,pjmedia_event_publish_falsg(1)); } In most case, it works correctly. But sometimes, it causes crash, it crash in pjsip_param_shallow_clone. Is it right to do this in another thread? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20140623/79bdf64c/attachment.html>