要了解pjsip的使用，simple_pjsua.c是一个很好的例子，虽然代码只有短短的172行，却展示了pjsua-lib层的完整使用流程、注册流程和基本呼叫流程。
来电的回调函数
呼叫状态改变的回调函数，没有做实质性的操作：
下面是学习过程中整理的simple_pjsua.c中的main函数主要流程：
先来看看pjsip-apps/src/samples/simple_pjsua.c的main函数
- /*
- * main()
- *
- * argv[1] may contain URL to call.
- */
- int main(int argc, char *argv[])
- {
- pjsua_acc_id acc_id;
- pj_status_t status;
- // 创建PJSIP
- /* Create pjsua first! */
- status = pjsua_create();
- if (status != PJ_SUCCESS) error_exit("Error in pjsua_create()", status);
- // 校验被叫SIP地址是否正确
- /* If argument is specified, it's got to be a valid SIP URL */
- if (argc > 1) {
- status = pjsua_verify_url(argv[1]);
- if (status != PJ_SUCCESS) error_exit("Invalid URL in argv", status);
- }
- // 初始化PJSUA，设置回调函数
- /* Init pjsua */
- {
- pjsua_config cfg;
- pjsua_logging_config log_cfg;
- pjsua_config_default(&cfg);
- cfg.cb.on_incoming_call = &on_incoming_call;
- cfg.cb.on_call_media_state = &on_call_media_state;
- cfg.cb.on_call_state = &on_call_state;
- pjsua_logging_config_default(&log_cfg);
- log_cfg.console_level = 4;
- status = pjsua_init(&cfg, &log_cfg, NULL);
- if (status != PJ_SUCCESS) error_exit("Error in pjsua_init()", status);
- }
- // 创建PJSIP的传输端口
- /* Add UDP transport. */
- {
- pjsua_transport_config cfg;
- pjsua_transport_config_default(&cfg);
- cfg.port = 5060;
- status = pjsua_transport_create(PJSIP_TRANSPORT_UDP, &cfg, NULL);
- if (status != PJ_SUCCESS) error_exit("Error creating transport", status);
- }
- // 启动PJSIP
- /* Initialization is done, now start pjsua */
- status = pjsua_start();
- if (status != PJ_SUCCESS) error_exit("Error starting pjsua", status);
- // 设置SIP用户帐号
- /* Register to SIP server by creating SIP account. */
- {
- pjsua_acc_config cfg;
- pjsua_acc_config_default(&cfg);
- cfg.id = pj_str("sip:" SIP_USER "@" SIP_DOMAIN);
- cfg.reg_uri = pj_str("sip:" SIP_DOMAIN);
- cfg.cred_count = 1;
- cfg.cred_info[0].realm = pj_str(SIP_DOMAIN);
- cfg.cred_info[0].scheme = pj_str("digest");
- cfg.cred_info[0].username = pj_str(SIP_USER);
- cfg.cred_info[0].data_type = PJSIP_CRED_DATA_PLAIN_PASSWD;
- cfg.cred_info[0].data = pj_str(SIP_PASSWD);
- status = pjsua_acc_add(&cfg, PJ_TRUE, &acc_id);
- if (status != PJ_SUCCESS) error_exit("Error adding account", status);
- }
- // 发起一个呼叫
- /* If URL is specified, make call to the URL. */
- if (argc > 1) {
- pj_str_t uri = pj_str(argv[1]);
- status = pjsua_call_make_call(acc_id, &uri, 0, NULL, NULL, NULL);
- if (status != PJ_SUCCESS) error_exit("Error making call", status);
- }
- // 循环等待
- /* Wait until user press "q" to quit. */
- for (;;) {
- char option[10];
- puts("Press 'h' to hangup all calls, 'q' to quit");
- if (fgets(option, sizeof(option), stdin) == NULL) {
- puts("EOF while reading stdin, will quit now..");
- break;
- }
- if (option[0] == 'q')
- break;
- if (option[0] == 'h')
- pjsua_call_hangup_all();
- }
- /* Destroy pjsua */
- pjsua_destroy();
- return 0;
- }
来电的回调函数
- //来电回调函数
- /* Callback called by the library upon receiving incoming call */
- static void on_incoming_call(pjsua_acc_id acc_id, pjsua_call_id call_id,
- pjsip_rx_data *rdata)
- {
- pjsua_call_info ci;
- PJ_UNUSED_ARG(acc_id);
- PJ_UNUSED_ARG(rdata);
- // 获得呼叫信息
- pjsua_call_get_info(call_id, &ci);
- PJ_LOG(3,(THIS_FILE, "Incoming call from %.*s!!",
- (int)ci.remote_info.slen,
- ci.remote_info.ptr));
- // 自动应答呼叫
- /* Automatically answer incoming calls with 200/OK */
- pjsua_call_answer(call_id, 200, NULL, NULL);
- }
呼叫状态改变的回调函数，没有做实质性的操作：
- //呼叫状态改变的回调函数
- /* Callback called by the library when call's state has changed */
- static void on_call_state(pjsua_call_id call_id, pjsip_event *e)
- {
- pjsua_call_info ci;
- PJ_UNUSED_ARG(e);
- pjsua_call_get_info(call_id, &ci);
- PJ_LOG(3,(THIS_FILE, "Call %d state=%.*s", call_id,
- (int)ci.state_text.slen,
- ci.state_text.ptr));
- }
- //媒体状态改变的回调函数
- /* Callback called by the library when call's media state has changed */
- static void on_call_media_state(pjsua_call_id call_id)
- {
- pjsua_call_info ci;
- pjsua_call_get_info(call_id, &ci);
- // 当媒体为激活时，连接呼叫和声音设备
- if (ci.media_status == PJSUA_CALL_MEDIA_ACTIVE) {
- // When media is active, connect call to sound device.
- pjsua_conf_connect(ci.conf_slot, 0);
- pjsua_conf_connect(0, ci.conf_slot);
- }
- }
