jrtplib3.9.1 example3

    用例子1发送，本例接收，运行窗口如下：
/*
   This IPv4 example listens for incoming packets and automatically adds destinations
   for new sources.
   本IPv4例子监听发送进来的数据包，并且自动为新的数据源添加目的端口
*/

#include "rtpsession.h"
#include "rtppacket.h"
#include "rtpudpv4transmitter.h"
#include "rtpipv4address.h"
#include "rtpsessionparams.h"
#include "rtperrors.h"
#ifndef WIN32
#include <netinet/in.h>
#include <arpa/inet.h>
#else
#include <winsock2.h>
#endif // WIN32
#include "rtpsourcedata.h"
#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <string>

using namespace jrtplib;

//
// This function checks if there was a RTP error. If so, it displays an error
// message and exists.
// 本函数检查是否有RTP错误，如果有，将其显示出来，并且退出

void checkerror(int rtperr)
{
if (rtperr < 0)
{
std::cout << "ERROR: " << RTPGetErrorString(rtperr) << std::endl;
exit(-1);
}
}

//
// The new class routine
// 一个新的继承自RTPSession的类

class MyRTPSession : public RTPSession
{
protected:
//有新的数据源，将对方的IP地址和端口自动添加到本类
void OnNewSource(RTPSourceData *dat)
{
if (dat->IsOwnSSRC())
return;

uint32_t ip;
uint16_t port;

if (dat->GetRTPDataAddress() != 0)
{
const RTPIPv4Address *addr = (const RTPIPv4Address *)(dat->GetRTPDataAddress());
ip = addr->GetIP();
port = addr->GetPort();
}
else if (dat->GetRTCPDataAddress() != 0)
{
const RTPIPv4Address *addr = (const RTPIPv4Address *)(dat->GetRTCPDataAddress());
ip = addr->GetIP();
port = addr->GetPort()-1;
}
else
return;

RTPIPv4Address dest(ip,port);
AddDestination(dest);
//此处自动添加上数据源的IP地址和端口

struct in_addr inaddr;
inaddr.s_addr = htonl(ip);
std::cout << "Adding destination " << std::string(inet_ntoa(inaddr)) << ":" << port << std::endl;
}

//收到BYE数据包（对方主动退出），则将对方ip地址和端口移除
void OnBYEPacket(RTPSourceData *dat)
{
if (dat->IsOwnSSRC())
return;

uint32_t ip;
uint16_t port;

if (dat->GetRTPDataAddress() != 0)
{
const RTPIPv4Address *addr = (const RTPIPv4Address *)(dat->GetRTPDataAddress());
ip = addr->GetIP();
port = addr->GetPort();
}
else if (dat->GetRTCPDataAddress() != 0)
{
const RTPIPv4Address *addr = (const RTPIPv4Address *)(dat->GetRTCPDataAddress());
ip = addr->GetIP();
port = addr->GetPort()-1;
}
else
return;

RTPIPv4Address dest(ip,port);
DeleteDestination(dest);

struct in_addr inaddr;
inaddr.s_addr = htonl(ip);
std::cout << "Deleting destination " << std::string(inet_ntoa(inaddr)) << ":" << port << std::endl;
}

//主动移除数据源，也应将对方的IP地址端口等删除
void OnRemoveSource(RTPSourceData *dat)
{
if (dat->IsOwnSSRC())
return;
if (dat->ReceivedBYE())
return;

uint32_t ip;
uint16_t port;

if (dat->GetRTPDataAddress() != 0)
{
const RTPIPv4Address *addr = (const RTPIPv4Address *)(dat->GetRTPDataAddress());
ip = addr->GetIP();
port = addr->GetPort();
}
else if (dat->GetRTCPDataAddress() != 0)
{
const RTPIPv4Address *addr = (const RTPIPv4Address *)(dat->GetRTCPDataAddress());
ip = addr->GetIP();
port = addr->GetPort()-1;
}
else
return;

RTPIPv4Address dest(ip,port);
DeleteDestination(dest);

struct in_addr inaddr;
inaddr.s_addr = htonl(ip);
std::cout << "Deleting destination " << std::string(inet_ntoa(inaddr)) << ":" << port << std::endl;
}
};

//
// The main routine
// 主函数

int main(void)
{
#ifdef WIN32
WSADATA dat;
WSAStartup(MAKEWORD(2,2),&dat);
#endif // WIN32

MyRTPSession sess;
uint16_t portbase;
std::string ipstr;
int status,i,num;

        // First, we'll ask for the necessary information
//首先，需要用户输入必要的信息
std::cout << "Enter local portbase:" << std::endl;//输入本地端口号
std::cin >> portbase;
std::cout << std::endl;

std::cout << std::endl;
std::cout << "Number of seconds you wish to wait:" << std::endl;//希望等待的秒数
std::cin >> num;

// Now, we'll create a RTP session, set the destination
// and poll for incoming data.
// 现在，创建一个RTP会话，设置目的端点，并且轮询等待发送进来的数据

RTPUDPv4TransmissionParams transparams;
RTPSessionParams sessparams;

// IMPORTANT: The local timestamp unit MUST be set, otherwise
//            RTCP Sender Report info will be calculated wrong
// In this case, we'll be just use 8000 samples per second.
// 重要：本地的时间戳单位必须要设定，否则RTCP发送报告信息将会计算错误。本例中，我们就用每秒8000个样本。
sessparams.SetOwnTimestampUnit(1.0/8000.0);

sessparams.SetAcceptOwnPackets(true);
transparams.SetPortbase(portbase);
status = sess.Create(sessparams,&transparams);
checkerror(status);

for (i = 1 ; i <= num ; i++)
{
sess.BeginDataAccess();

// check incoming packets
// 检查发送进来的数据包
if (sess.GotoFirstSourceWithData())
{
do
{
RTPPacket *pack;

while ((pack = sess.GetNextPacket()) != NULL)
{
// You can examine the data here
// 你可在此处检查收到的数据
printf("Got packet !\n");

// we don't longer need the packet, so
// we'll delete it
// 我们不再需要此数据包，所以我们删除它
sess.DeletePacket(pack);
}
} while (sess.GotoNextSourceWithData());
}

sess.EndDataAccess();

#ifndef RTP_SUPPORT_THREAD
status = sess.Poll();
checkerror(status);
#endif // RTP_SUPPORT_THREAD

RTPTime::Wait(RTPTime(1,0));
}

sess.BYEDestroy(RTPTime(10,0),0,0);

#ifdef WIN32
WSACleanup();
#endif // WIN32
return 0;
}