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ffmpeg解封装rtsp并录制视频-（1）解封装rtsp断网或摄像机重启后自动重连处理

news 来源：原创 2024/6/26 11:38:27

头文件：

xtools.h


#pragma once
#include <thread>
#include <iostream>
#include <mutex>
//日志级别 DEBUG INFO ERROR FATAL
enum XLogLevel
{XLOG_TYPE_DEBUG,XLOG_TYPE_INFO,XLOG_TPYE_ERROR,XLOG_TYPE_FATAL
};
#define LOG_MIN_LEVEL XLOG_TYPE_DEBUG
#define XLOG(s,level) \if(level>=LOG_MIN_LEVEL) \std::cout<<level<<":"<<__FILE__<<":"<<__LINE__<<":\n"\<<s<<std::endl;
#define LOGDEBUG(s) XLOG(s,XLOG_TYPE_DEBUG)
#define LOGINFO(s) XLOG(s,XLOG_TYPE_INFO)
#define LOGERROR(s) XLOG(s,XLOG_TPYE_ERROR)
#define LOGFATAL(s) XLOG(s,XLOG_TYPE_FATAL)
void MSleep(unsigned int ms);//获取当前时间戳 毫秒
long long NowMs();class XThread
{
public://启动线程virtual void Start();//停止线程（设置退出标志，等待线程退出）virtual void Stop();protected://线程入口函数virtual void Main() = 0;//标志线程退出bool is_exit_ = false;//线程索引号int index_ = 0;
private:std::thread th_;std::mutex m_;};
class XTools
{
};

xdemux_task.h

#pragma once
#include "xtools.h"
#include "xdemux.h"
class XDemuxTask :public XThread
{
public:void Main();/// <summary>/// 打开解封装/// </summary>/// <param name="url">rtsp地址</param>/// <param name="timeout_ms">超时时间 单位毫秒</param>/// <returns></returns>bool Open(std::string url,int timeout_ms = 1000);
private:XDemux demux_;std::string url_;int timeout_ms_ = 0;//超时时间
};

xformat.h

#pragma once
/// <summary>
/// 封装和解封装基类
/// </summary>
#include <mutex>
#include"xtools.h"
struct AVFormatContext;
struct AVCodecParameters;
struct AVPacket;
struct AVCodecContext;
struct XRational
{int num; ///< Numeratorint den; ///< Denominator
};
class XFormat
{
public:/// <summary>/// 复制参数 线程安全/// </summary>/// <param name="stream_index">对应c_->streams 下标</param>/// <param name="dst">输出参数</param>/// <returns>是否成功</returns>bool CopyPara(int stream_index, AVCodecParameters* dst);bool CopyPara(int stream_index, AVCodecContext* dts);/// <summary>/// 设置上下文，并且清理上次的设置的值，如果传递NULL，相当于关闭上下文3/// 线程安全/// </summary>/// <param name="c"></param>void set_c(AVFormatContext* c);int audio_index() { return audio_index_; }int video_index() { return video_index_; }XRational video_time_base(){ return video_time_base_; }XRational audio_time_base() { return audio_time_base_; }//根据timebase换算时间bool RescaleTime(AVPacket *pkt,long long offset_pts, XRational time_base);int video_codec_id() { return video_codec_id_; }//判断是否超时bool IsTimeout(){if (NowMs() - last_time_ > time_out_ms_) //超时{last_time_ = NowMs();is_connected_ = false;return true;}return false;}//设定超时时间void set_time_out_ms(int ms);bool is_connected() { return is_connected_; }protected:int time_out_ms_ = 0;           //超时时间 毫秒long long last_time_ = 0;bool is_connected_ = false;     //是否连接成功AVFormatContext* c_ = nullptr;  //封装解封装上下文std::mutex mux_;                //c_ 资源互斥int video_index_ = 0;//video和audio在stream中索引int audio_index_ = 1;XRational video_time_base_ = {1,25};XRational audio_time_base_ = {1,9000};int video_codec_id_ = 0;       //编码器ID
};

xdemux.h


#pragma once
#include "xformat.h"
class XDemux :public XFormat
{
public:/// <summary>/// 打开解封装/// </summary>/// <param name="url">解封装地址 支持rtsp</param>/// <returns>失败返回nullptr</returns>static AVFormatContext* Open(const char* url);/// <summary>/// 读取一帧数据/// </summary>/// <param name="pkt">输出数据</param>/// <returns>是否成功</returns>bool Read(AVPacket* pkt);bool Seek(long long pts,int stream_index);};

源文件：

xtools.cpp

#include "xtools.h"
#include <sstream>
using namespace std;
void MSleep(unsigned int ms)
{auto beg = clock();for (int i = 0; i < ms; i++){this_thread::sleep_for(1ms);if ((clock() - beg) / (CLOCKS_PER_SEC / 1000) >= ms)break;}
}
long long NowMs()
{return clock() / (CLOCKS_PER_SEC / 1000);
}
//启动线程
void XThread::Start()
{unique_lock<mutex> lock(m_);static int i = 0;i++;index_ = i;is_exit_ = false;//启动线程th_ = thread(&XThread::Main, this);stringstream ss;ss << "XThread::Start()" << index_;LOGINFO(ss.str());
}//停止线程（设置退出标志，等待线程退出）
void XThread::Stop()
{stringstream ss;ss << "XThread::Stop() begin" << index_;LOGINFO(ss.str());is_exit_ = true;if (th_.joinable()) //判断子线程是否可以等待th_.join();     //等待子线程退出ss.str("");ss << "XThread::Stop() end" << index_;LOGINFO(ss.str());
}

xdemux_task.cpp


#include "xdemux_task.h"
extern "C"
{
#include <libavformat/avformat.h>
}
using namespace std;
bool XDemuxTask::Open(std::string url, int timeout_ms)
{LOGDEBUG("XDemuxTask::Open begin!");demux_.set_c(nullptr);//断开之前的连接this->url_ = url;this->timeout_ms_ = timeout_ms;auto c = demux_.Open(url.c_str());if (!c)return false;demux_.set_c(c);demux_.set_time_out_ms(timeout_ms);LOGDEBUG("XDemuxTask::Open end!");return true;
}
void XDemuxTask::Main()
{AVPacket pkt;while (!is_exit_){if (!demux_.Read(&pkt)){//读取失败cout << "-" << flush;if (!demux_.is_connected())//如果断开连接，需要重新连接{Open(url_, timeout_ms_);}this_thread::sleep_for(1ms);continue;}cout << "." << flush;this_thread::sleep_for(1ms);}
}

xformat.cpp

#include "xformat.h"
#include <iostream>
#include <thread>
#include "xtools.h"
using namespace std;
extern "C" { //指定函数是c语言函数，函数名不包含重载标注
//引用ffmpeg头文件
#include <libavformat/avformat.h>
}
//预处理指令导入库
#pragma comment(lib,"avformat.lib")
#pragma comment(lib,"avutil.lib")
using namespace std;
static int TimeoutCallback(void* para)
{auto xf = (XFormat*)para;if (xf->IsTimeout())return 1;//超时退出Read//cout << "TimeoutCallback" << endl;return 0; //正常阻塞
}
void XFormat::set_c(AVFormatContext* c)
{unique_lock<mutex> lock(mux_);if (c_) //清理原值{if (c_->oformat) //输出上下文{if (c_->pb)avio_closep(&c_->pb);avformat_free_context(c_);}else if (c_->iformat)  //输入上下文{avformat_close_input(&c_);}else{avformat_free_context(c_);}}c_ = c;if (!c_){is_connected_ = false;return;}is_connected_ = true;//计时 用于超时判断last_time_ = NowMs();//设定超时处理回调if (time_out_ms_ > 0){AVIOInterruptCB cb = { TimeoutCallback ,this };c_->interrupt_callback = cb;}//用于区分是否有音频或者视频流audio_index_ = -1; video_index_ = -1;//区分音视频stream 索引for (int i = 0; i < c->nb_streams; i++){//音频if (c->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO){audio_index_ = i;audio_time_base_.den = c->streams[i]->time_base.den;audio_time_base_.num = c->streams[i]->time_base.num;}else if (c->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO){video_index_ = i;video_time_base_.den = c->streams[i]->time_base.den;video_time_base_.num = c->streams[i]->time_base.num;video_codec_id_ = c->streams[i]->codecpar->codec_id;}}
}bool XFormat::CopyPara(int stream_index, AVCodecContext* dts)
{unique_lock<mutex> lock(mux_);if (!c_){return false;}if (stream_index<0 || stream_index>c_->nb_streams)return false;auto re = avcodec_parameters_to_context(dts, c_->streams[stream_index]->codecpar);if (re < 0){return false;}return true;
}
/// <summary>
/// 复制参数 线程安全
/// </summary>
/// <param name="stream_index">对应c_->streams 下标</param>
/// <param name="dst">输出参数</param>
/// <returns>是否成功</returns>
bool XFormat::CopyPara(int stream_index, AVCodecParameters* dst)
{unique_lock<mutex> lock(mux_);if (!c_){return false;}if (stream_index<0 || stream_index>c_->nb_streams)return false;auto re = avcodec_parameters_copy(dst, c_->streams[stream_index]->codecpar);if (re < 0){return false;}return true;
}bool XFormat::RescaleTime(AVPacket* pkt, long long offset_pts, XRational time_base)
{unique_lock<mutex> lock(mux_);if (!c_)return false;        auto out_stream = c_->streams[pkt->stream_index];AVRational in_time_base;in_time_base.num = time_base.num;in_time_base.den = time_base.den;pkt->pts = av_rescale_q_rnd(pkt->pts- offset_pts, in_time_base,out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));pkt->dts = av_rescale_q_rnd(pkt->dts- offset_pts, in_time_base,out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));pkt->duration = av_rescale_q(pkt->duration, in_time_base, out_stream->time_base);pkt->pos = -1;return true;
}//设定超时时间
void XFormat::set_time_out_ms(int ms)
{unique_lock<mutex> lock(mux_);this->time_out_ms_ = ms;//设置回调函数，处理超时退出if (c_){//AVIOInterruptCB结构体：这是FFmpeg中用于处理I/O操作中断的结构体，包含一个回调函数指针和一个用户数据指针。AVIOInterruptCB cb = { TimeoutCallback ,this };//看下面的注释结构体 c_->interrupt_callback = cb;}/* typedef struct AVIOInterruptCB {int (*callback)(void*);void* opaque;} AVIOInterruptCB;*/}

xdemux.cpp

#include "xdemux.h"
#include <iostream>
#include <thread>
#include"xtools.h"
#include"xcodec.h"
using namespace std;
extern "C" { //指定函数是c语言函数，函数名不包含重载标注
//引用ffmpeg头文件
#include <libavformat/avformat.h>
}
void PrintErr(int err);
#define BERR(err) if(err!= 0){PrintErr(err);return 0;}
AVFormatContext* XDemux::Open(const char* url)
{AVFormatContext* c = nullptr;AVDictionary* opts = nullptr;//av_dict_set(&opts, "rtsp_transport", "tcp", 0);//传输媒体流为tcp协议，默认udpav_dict_set(&opts, "stimeout", "1000000", 0);//连接超时1秒//打开封装上下文auto re = avformat_open_input(&c, url, nullptr, &opts);if (opts)av_dict_free(&opts);BERR(re);//获取媒体信息re = avformat_find_stream_info(c, nullptr);BERR(re);//打印输入封装信息av_dump_format(c, 0, url, 0);return c;
}bool XDemux::Read(AVPacket* pkt)
{unique_lock<mutex> lock(mux_);if (!c_)return false;auto re = av_read_frame(c_, pkt);BERR(re);//计时 用于超时判断last_time_ = NowMs();return true;
}bool XDemux::Seek(long long pts, int stream_index)
{unique_lock<mutex> lock(mux_);if (!c_)return false;auto re = av_seek_frame(c_, stream_index, pts,AVSEEK_FLAG_FRAME | AVSEEK_FLAG_BACKWARD);BERR(re);return true;
}

main.cpp

#include <iostream>
#include <thread>
#include "xtools.h"
#include "xdemux_task.h"
using namespace std;
//class TestThread :public XThread
//{
//public:
//    void Main()
//    {
//        LOGDEBUG("TestThread Main begin");
//        while (!is_exit_)
//        {
//            this_thread::sleep_for(1ms);
//        }
//        LOGDEBUG("TestThread Main end");
//    }
//};
#define CAM1 \
"rtsp://admin:admin@192.168.2.108/cam/realmonitor?channel=1&subtype=0"
#define MP4 "v1080.mp4"
int main(int argc, char* argv[])
{XDemuxTask det;for (;;)//保证第一次连接就失败的情况{if (det.Open(CAM1))//进行解封装得到pkt{break;}MSleep(100);continue;}
//启动主线程Main函数进行解码det.Start();//TestThread tt;//tt.Start();//this_thread::sleep_for(3s);//tt.Stop();getchar();return 0;
}[点击并拖拽以移动]

主函数执行分析：

det对象用于对rtsp进行解封装，通过调用open函数，该函数调用Xdemux_task的成员demux对象对其进行解封装得到解封装上下文，再用set_c初始化设置解封装上下文，再用demux对象调用set_time_out_ms函数，该函数在xformat里，demux类继承xformat所以可以调用，作用是设定超时时间，如果断开连接则会调用一个回调函数TimeOutCallBack函数对时间进行判断是否超时，如果超时则退出，解封装后det再调用线程启动函数启动主线程Main函数，用read_frame函数把解封装后的rtsp进行读取存储到pkt中准备进行pkt->frame的解码，读取过程中如果摄像头断开会自动调用Open函数进行重新解封装。