jrtplib3.9.1 example5

*转载时请注明出处。
http://blog.csdn.net/str999_cn/article/details/28173559
    此代码执行时，如果只发送1个数据包，发送和接收完毕，会自动退出。没问题。但一旦发送的数据包等会或超过2个时，则程序执行时会无休无止地分配和释放，还没来得及去搞清为什么是这样的。
    执行图片如下：
/*
   This is a modified version of example1.cpp to illustrate the use of a memory
   manager.
   这是对示例1的一个修改版本，用以展示内存管理的使用
*/

#include "rtpsession.h"
#include "rtppacket.h"
#include "rtpudpv4transmitter.h"
#include "rtpipv4address.h"
#include "rtpsessionparams.h"
#include "rtperrors.h"
#include "rtpmemorymanager.h"
#ifndef WIN32
#include <netinet/in.h>
#include <arpa/inet.h>
#else
#include <winsock2.h>
#endif // WIN32
#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，本函数显示错误信息，然后退出。

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

#ifdef RTP_SUPPORT_THREAD
//此处定义了RTP_SUPPORT_THREAD，会用到jthread这个单独的库。所以多定义了一个JMutex mutex;在进行内存分配和释放的时候，需要加锁和解锁。

using namespace jthread;

class MyMemoryManager : public RTPMemoryManager
{
public:
MyMemoryManager() 
{ 
mutex.Init();
alloccount = 0; 
freecount = 0; 
}
~MyMemoryManager() 
{ 
std::cout << "alloc: " << alloccount << " free: " << freecount << std::endl; 
}
void *AllocateBuffer(size_t numbytes, int memtype)
{
mutex.Lock();
void *buf = malloc(numbytes);
std::cout << "Allocated " << numbytes << " bytes at location " << buf 
<< " (memtype = " << memtype << ")" << std::endl;
alloccount++;
mutex.Unlock();
return buf;
}

void FreeBuffer(void *p)
{
mutex.Lock();
std::cout << "Freeing block " << p << std::endl;
freecount++;
free(p);
mutex.Unlock();
}
private:
int alloccount,freecount;
JMutex mutex;
};

#else

class MyMemoryManager : public RTPMemoryManager
{
public:
MyMemoryManager() 
{ 
alloccount = 0; 
freecount = 0; 
}
~MyMemoryManager() 
{ 
std::cout << "alloc: " << alloccount << " free: " << freecount << std::endl; 
}
void *AllocateBuffer(size_t numbytes, int memtype)
{
void *buf = malloc(numbytes);
std::cout << "Allocated " << numbytes << " bytes at location " << buf 
<< " (memtype = " << memtype << ")" << std::endl;
alloccount++;
return buf;
}

void FreeBuffer(void *p)
{
std::cout << "Freeing block " << p << std::endl;
freecount++;
free(p);
}
private:
int alloccount,freecount;
};

#endif // RTP_SUPPORT_THREAD

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

MyMemoryManager mgr;
RTPSession sess(0, &mgr);
uint16_t portbase,destport;
uint32_t destip;
std::string ipstr;
int status,i,num;

        // First, we'll ask for the necessary information
// 首先，让用户输入一些必要的信息
std::cout << "Enter local portbase:" << std::endl;
std::cin >> portbase;
std::cout << std::endl;

std::cout << "Enter the destination IP address" << std::endl;
std::cin >> ipstr;
destip = inet_addr(ipstr.c_str());
if (destip == INADDR_NONE)
{
std::cerr << "Bad IP address specified" << std::endl;
return -1;
}

// The inet_addr function returns a value in network byte order, but
// we need the IP address in host byte order, so we use a call to
// ntohl
// 函数inet_addr 返回网络字节序的值，但我们需要的IP地址是要主机字节序，所以我们调用ntohl函数
destip = ntohl(destip);

std::cout << "Enter the destination port" << std::endl;
std::cin >> destport;

std::cout << std::endl;
std::cout << "Number of packets you wish to be sent:" << std::endl;
std::cin >> num;

// Now, we'll create a RTP session, set the destination, send some
// packets and poll for incoming data.
// 现在，我们将创建一个RTP会话，设置目的端点，发送一些数据包，然后轮询等待发进来的数据

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 sending 10 samples each second, so we'll
// put the timestamp unit to (1.0/10.0)
// 重要信息：本地的时间戳单位必须要设置，否则RTCP发送报告信息将会计算错误
// 在本例，我们将每秒发送10个样本，所以我们将时间戳单位设置为（1.0/10.0）
sessparams.SetOwnTimestampUnit(1.0/10.0);

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

RTPIPv4Address addr(destip,destport);

status = sess.AddDestination(addr);
checkerror(status);

for (i = 1 ; i <= num ; i++)
{
printf("\nSending packet %d/%d\n",i,num);

// send the packet 发送数据包
status = sess.SendPacket((void *)"1234567890",10,0,false,10);
checkerror(status);

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 你可以在此处检查（收到的）数据
printf("Got packet !\n");

// we don't longer need the packet, so
// we'll delete it
// 我们不再需要这个数据包，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;
}