FFmpeg rtsp交互实现以及问题解决

知识准备

            默认情况下，wireshark并没有分析数据包的内容，从而判断是否是rtsp数据包，它是根据端口，默认端口是554，认为是进行rtsp协议会话，所以会在捕获界面显示数据包的Protocol协议，如果知道哪些端口也是进行rtsp会话的情况下，可以在菜单栏中选择分析，点击编码为，在字段中选择tcp port 值填写指定的端口，然后在当前的协议中，选择RTSP。另外，可以通过鼠标右键选择追踪流，点击其中的TCP，查看RTSP的交互过程

问题以及解决方案

1)405 Method Not Allowed
主要是在进行OPTIONS指令包封装的时候，通过wireshark抓包进行编写，报文内容如下：

Request: OPTIONS rtsp:://192.168.1.88 RTSP/1.0\r\n
Method: OPTIONS
URL: rtsp:://192.168.1.88
以为信息的开头是Request，实际上这是解析的语句
错误：
request_stream << "REQUEST: " <<"OPTIONS " << "rtsp://192.168.0.114 " << "RTSP/1.0\r\n";
request_stream << "CSeq: " << "2\r\n";
request_stream << "User-Agent: " << "LibVLC/2.1.5 (Live555 Streaming Media v2014.0)\r\n\r\n";

正确：
request_stream << "OPTIONS " << "rtsp://192.168.0.114 " << "RTSP/1.0\r\n";
request_stream << "CSeq: " << "2\r\n";
request_stream << "User-Agent: " << "LibVLC/2.1.5 (Live555 Streaming Media v2014.0)\r\n\r\n";

2)404 Stream Not Found
主要是在进行DESCRIBE的时候没有填写获取的视频流信息
错误:
request_stream << "DESCRIBE " << "rtsp://192.168.0.114 " << "RTSP/1.0\r\n";
正确:
request_stream << "DESCRIBE " << "rtsp://192.168.0.114/smoke.264 " << "RTSP/1.0\r\n";//error

3) 451 Parameter Not Understood

主要是url后面没有指定trackid,例如指定/trackID=0

错误：

SETUP rtsp://192.168.18.201:554/cam/realmonitor?channel=1&subtype=0 RTSP/1.0
CSeq: 4
User-Agent: LibVLC/2.2.8 (LIVE555 Streaming Media v2017.08.22)
Authorization: Digest username="admin", realm="Login to 4M01111PAJB50A1", nonce="3344152e2d9f717b3c3f29792f31e125", uri="rtsp://192.168.18.201:554/cam/realmonitor?channel=1&subtype=0", response="d69d677d06e9a5471327ff977cc09d9e"
Transport: RTP/AVP;unicast;client_port=45056-45057
RTSP/1.0 451 Parameter Not Understood
CSeq: 4
Session: 1029986489118

正确：

SETUP rtsp://192.168.18.201:554/cam/realmonitor?channel=1&subtype=0/trackID=0 RTSP/1.0
CSeq: 5
User-Agent: LibVLC/2.2.8 (LIVE555 Streaming Media v2017.08.22)
Authorization: Digest username="admin", realm="Login to 4M01111PAJB50A1", nonce="ba0a98388d61508258fc859081a62fb0", uri="rtsp://192.168.18.201:554/cam/realmonitor?channel=1&subtype=0", response="c72d514d419ee7383c4cc1f94a0b785d"
Session: 1039947334568
Transport: RTP/AVP;unicast;client_port=45058-45059

测试代码
#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <boost/asio.hpp>
#include "socket.h"

using namespace std;
using namespace boost::asio;

const char pszRtspServerIP[32] = "192.168.0.114";
short sRtspServerPort = 8554;

void WriteFile(char* buf);
{
ofstream ofs;
ofs.open("rtspoption.txt");
ofs << buf << endl;
ofs.close();
}

int HandleOptionCommand(ip::tcp::socket &sock)
{
boost::system::error_code ec;
boost::asio::streambuf request;
std::ostream request_stream(&request);
request_stream << "OPTIONS " << "rtsp://192.168.0.114 " << "RTSP/1.0\r\n";
request_stream << "CSeq: " << "2\r\n";
request_stream << "User-Agent: " << "LibVLC/2.1.5 (Live555 Streaming Media v2014.0)\r\n\r\n";

boost::asio::write(sock, request);

char buf[1024] = { 0 };
size_t len = sock.read_some(buffer(buf), ec);
return 0;
}

int HanleDescribeCommand(ip::tcp::socket &sock)
{
boost::system::error_code ec;
boost::asio::streambuf request;
std::ostream request_stream(&request);
request_stream << "DESCRIBE " << "rtsp://192.168.0.114/smoke.264 " << "RTSP/1.0\r\n";
request_stream << "CSeq: " << "3\r\n";
request_stream << "Accept: " << "application/sdp\r\n";
request_stream << "User-Agent: " << "LibVLC/2.1.5 (Live555 Streaming Media v2014.0)\r\n\r\n";

boost::asio::write(sock, request);

char buf[1024] = { 0 };
size_t len = sock.read_some(buffer(buf), ec);
//a=control:track1
return 0;
}

int HandleSetupCommand(ip::tcp::socket &sock)
{
boost::system::error_code ec;
boost::asio::streambuf request;
std::ostream request_stream(&request);
request_stream << "SETUP " << "rtsp://192.168.0.114/smoke.264 " << "RTSP/1.0\r\n";
request_stream << "CSeq: " << "3\r\n";
request_stream << "Transport: " << "RTP/AVP/TCP;unicast;interleaved=0-1\r\n";
request_stream << "User-Agent: " << "LibVLC/2.1.5 (Live555 Streaming Media v2014.0)\r\n\r\n";

boost::asio::write(sock, request);

char buf[1024] = { 0 };
size_t len = sock.read_some(buffer(buf), ec);
return 0;

}

int main(int argc, char* argv[])
{
io_service iosev;
ip::tcp::socket socket(iosev);
ip::tcp::endpoint ep(ip::address_v4::from_string(pszRtspServerIP), sRtspServerPort);
boost::system::error_code ec;
socket.connect(ep, ec);
if (ec) return -1;

HandleOptionCommand(socket);
HanleDescribeCommand(socket);
HandleSetupCommand(socket);

return 0;
}