---

Не заработало, думаю надо взять этот код за основу   
     if (need_reopen) {
            if (pjsua_var.cap_dev != PJSUA_SND_NULL_DEV) {
                pjmedia_snd_port_param param;

                pjmedia_snd_port_param_default(&param);
                param.ec_options = pjsua_var.media_cfg.ec_options;

                /* Create parameter based on peer info */
                status = create_aud_param(&param.base, pjsua_var.cap_dev,
                                          pjsua_var.play_dev,
                                          peer_info.clock_rate,
                                          peer_info.channel_count,
                                          peer_info.samples_per_frame,
                                          peer_info.bits_per_sample,
                                          PJ_FALSE);
                if (status != PJ_SUCCESS) {
                    pjsua_perror(THIS_FILE, "Error opening sound device",
                                 status);
                    goto on_return;
                }

                /* And peer format */
                if (peer_info.format.id != PJMEDIA_FORMAT_PCM) {
                    param.base.flags |= PJMEDIA_AUD_DEV_CAP_EXT_FORMAT;
                    param.base.ext_fmt = peer_info.format;
                }

                param.options = 0;
                status = open_snd_dev(&param);
                if (status != PJ_SUCCESS) {
                    pjsua_perror(THIS_FILE, "Error opening sound device",
                                 status);
                    goto on_return;
                }
            } else {
                /* Null-audio */
                status = pjsua_set_snd_dev(pjsua_var.cap_dev,
                                           pjsua_var.play_dev);
                if (status != PJ_SUCCESS) {
                    pjsua_perror(THIS_FILE, "Error opening sound device",
                                 status);
                    goto on_return;
                }
            }
        }