ortp 发送RTP实例

参考源代码目录src/tests/rtpsend.c

    ortp_init();
    ortp_scheduler_init();
    ortp_set_log_level_mask(ORTP_MESSAGE|ORTP_WARNING|ORTP_ERROR);
    session=rtp_session_new(RTP_SESSION_SENDONLY);
    rtp_session_set_local_addr(session,"192.168.1.16",10000,10001);
    rtp_session_set_scheduling_mode(session,1);
    rtp_session_set_blocking_mode(session,1);
    //rtp_session_set_connected_mode(session,TRUE);
    rtp_session_set_connected_mode(session,0);
    rtp_session_set_remote_addr(session,argv[2],atoi(argv[3]));
    rtp_session_set_payload_type(session,8);

    ssrc=getenv("SSRC");
    if (ssrc!=NULL) {
        printf("using SSRC=%i.
",atoi(ssrc));
        rtp_session_set_ssrc(session,atoi(ssrc));
    }
    rtp_session_set_ssrc(session,0);

    infile=fopen(argv[1],"r");
    if (infile==NULL) {
        perror("Cannot open file");
        return -1;
    }

    signal(SIGINT,stophandler);
    while( ((i=fread(buffer,1,160,infile))>0) && (runcond) )
    {
        rtp_session_send_with_ts(session,buffer,i,user_ts);
        user_ts+=160;
        if (clockslide!=0 && user_ts%(160*50)==0){
            ortp_message("Clock sliding of %i miliseconds now",clockslide);
            rtp_session_make_time_distorsion(session,clockslide);
        }
        /*this will simulate a burst of late packets */
        if (jitter && (user_ts%(8000)==0)) {
            struct timespec pausetime, remtime;
            ortp_message("Simulating late packets now (%i milliseconds)",jitter);
            pausetime.tv_sec=jitter/1000;
            pausetime.tv_nsec=(jitter%1000)*1000000;
            while(nanosleep(&pausetime,&remtime)==-1 && errno==EINTR){
                pausetime=remtime;
            }
        }
    }

    fclose(infile);
    rtp_session_destroy(session);
    ortp_exit();
    ortp_global_stats_display();

代码解读：

1、如果不手动调用rtp_session_set_local_addr设置本地RTP IP/PORT和RTCP PORT，ortp会自动选择可用端口；

2、rtp_session_set_connected_mode设置连接模式，如果为1，会根据RTCP判断是否连接上；

3、上述代码是发送PCM A/U律代码，rtp_session_set_payload_type设置编码格式；

4、支持多线程；