Hello. I have tried to use pjsua for creating a testapplication that can call someone and playback some audio through the connection. The calling works okay, I guess, but when calling pjsua_player_create i get the error-log-message: 16:44:55.059 pjsua_aud.c ......Unable to add file to conference bridge: Invalid operation (PJ_EINVALIDOP) [status=70013] Why is that? How can I create a player-object and add it to the conference bridge so the remote participant can hear the file I play. When I call the function pjsua_player_get_conf_port() after creating the player-object, the application crashes on assertion: myapp: ../src/pjsua-lib/pjsua_aud.c:1191: pjsua_player_get_conf_port: Assertion `pjsua_var.player[id].port != ((void *)0)' failed. In that regard, there are some difficulties with detecting sound devices. I use the following sub-program to get the detected sound-devices of pjsua: pjmedia_aud_dev_info arr[8]; unsigned int num = 8; pjsua_enum_aud_devs( arr, &(num) ); printf ("Gefundene Ger?te: %d\n", num); for (unsigned int i=0; i<num; i++) { printf ("-- Name: %s (in %d, out %d)\n", arr[i].name, arr[i].input_count, arr[i].output_count); } When pjsua is installed for Xubuntu 14.04 repositories, there are devices "pulse" and "default", when built from sources (version 2.1) on Xubuntu 12.04 there are no devices detected. How can I fix that? I installed pretty much everthing ffmpeg and v4l2-like I could find. And there is one thing left, an error in the documentation: http://www.pjsip.org/docs/latest-2/pjsip/docs/html/group__PJSUA__LIB__MEDIA.htm under the heading "Detailed Description", there is code given, but this code would not even compile, for there a no parameter given for the functions pjsua_player_get_conf_port(). Regards Stefan Naumann