Qt FFMPEG+OpenCV开启摄像头

//ffmpegDecode.h

#ifndef __FFMPEG_DECODE_H__
#define __FFMPEG_DECODE_H__

#include "global.h"

extern "C"
{
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
//图像转换结构需要引入的头文件
#include "libswscale/swscale.h"
};
 
class ffmpegDecode
{
public:
    ffmpegDecode(char * file = NULL);
        ~ffmpegDecode();

        cv::Mat getDecodedFrame();
        cv::Mat getLastFrame();
        int readOneFrame();
        int getFrameIndex(){return m_framIndex;};

    private:
        AVFrame *pAvFrame;
        AVFormatContext *pFormatCtx;
        AVCodecContext  *pCodecCtx;
        AVCodec         *pCodec;

        int i;
        int videoindex;
        int m_framIndex;
        char *filepath;
        int ret, got_picture;
        SwsContext *img_convert_ctx;
        int y_size;
        AVPacket *packet;

        cv::Mat *pCvMat;

        bool m_initResult;

        bool init();
        bool openDecode();
        void prepare();
        void get(AVCodecContext *pCodecCtx, SwsContext *img_convert_ctx,AVFrame *pFrame);

public:
        bool getInitResult();

};

#endif

//ffmpegDecode.cpp

#include "ffmpegDecode.h"
#include <QDebug>

int time_out = 0;
int firsttimeplay = 1;
int interrupt_cb(void *ctx)
{
    // do something

    time_out++;
    if (time_out > 40) {
        time_out=0;
        if (firsttimeplay) {
            firsttimeplay=0;
            return -1;//这个就是超时的返回
        }
    }
    return 0;
}

ffmpegDecode :: ~ffmpegDecode()
{
    pCvMat->release();
    
    pCvMat->release();
    //释放本次读取的帧内存
    av_free_packet(packet);
    avcodec_close(pCodecCtx);
    avformat_close_input(&pFormatCtx);  
}

ffmpegDecode :: ffmpegDecode(char * file)
{
    firsttimeplay = 1;
    pAvFrame = NULL/**pFrameRGB = NULL*/;
    pFormatCtx  = NULL;
    pCodecCtx   = NULL;
    pCodec      = NULL;

    pCvMat = new cv::Mat();
    i=0;
    videoindex=0;
    m_framIndex =0;
    ret = 0;
    got_picture = 0;
    img_convert_ctx = NULL;
    y_size = 0;
    packet = NULL;

    if (NULL == file)
    {
        filepath =  "rtsp://admin:admin123@192.168.10.239:554";
    }
    else
    {
        filepath = file;
    }

    m_initResult = false;
    if(init())
    {
        if(openDecode())
        {
            prepare();
            m_initResult =true;
        }
    }

}

bool ffmpegDecode::getInitResult()
{
    return m_initResult;
}

bool ffmpegDecode :: init()
{
    printf("init start...
");
    //ffmpeg注册复用器，编码器等的函数av_register_all()。
    //该函数在所有基于ffmpeg的应用程序中几乎都是第一个被调用的。只有调用了该函数，才能使用复用器，编码器等。
    //这里注册了所有的文件格式和编解码器的库，所以它们将被自动的使用在被打开的合适格式的文件上。注意你只需要调用 av_register_all()一次，因此我们在主函数main()中来调用它。如果你喜欢，也可以只注册特定的格式和编解码器，但是通常你没有必要这样做。
    av_register_all();
     avformat_network_init();
//    pFormatCtx = avformat_alloc_context();
//    pFormatCtx->interrupt_callback.callback = interrupt_cb;//--------注册回调函数

//    pFormatCtx->interrupt_callback.opaque = pFormatCtx;
    //打开视频文件,通过参数filepath来获得文件名。这个函数读取文件的头部并且把信息保存到我们给的AVFormatContext结构体中。
    //最后2个参数用来指定特殊的文件格式，缓冲大小和格式参数，但如果把它们设置为空NULL或者0，libavformat将自动检测这些参数。
    
    AVDictionary* options = NULL;  
        av_dict_set(&options, "rtsp_transport", "tcp", 0);  
        av_dict_set(&options, "stimeout", "2000000", 0); //设置超时断开连接时间，单位微秒

    if(avformat_open_input(&pFormatCtx,filepath,NULL,&options)!=0)
    {
        printf("无法打开文件
");
        return false;
    }

    //查找文件的流信息,avformat_open_input函数只是检测了文件的头部，接着要检查在文件中的流的信息
    if(avformat_find_stream_info(pFormatCtx,&options)<0)
    {
        printf("Couldn't find stream information.
");
        return false;
    }
    printf("init finished...
");

    return true;
}

bool ffmpegDecode :: openDecode()
{
     printf("openDecode start...
");
    //在库里面查找支持该格式的解码器
    videoindex = -1;
    for(i=0; i<pFormatCtx->nb_streams; i++) 
    {
        if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO)
        {
            videoindex=i;
            break;
        }
    }
    if(videoindex==-1)
    {
        printf("Didn't find a video stream.
");
        return false;
    }
    pCodecCtx=pFormatCtx->streams[videoindex]->codec;

    //在库里面查找支持该格式的解码器
    pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
    if(pCodec==NULL)
    {
        printf("Codec not found.
");
        return false;
    }

    //打开解码器
    if(avcodec_open2(pCodecCtx, pCodec,NULL) < 0)
    {
        printf("Could not open codec.
");
        return false;
    }
      printf("openDecode finished
");

      return true;
}

void ffmpegDecode :: prepare()
{
    //printf("prepare int
");
  //分配一个帧指针，指向解码后的原始帧
    pAvFrame=av_frame_alloc();
    y_size = pCodecCtx->width * pCodecCtx->height;
    //分配帧内存
    packet=(AVPacket *)av_malloc(sizeof(AVPacket));
    av_new_packet(packet, y_size);

    //输出一下信息-----------------------------
    printf("文件信息-----------------------------------------
");
    av_dump_format(pFormatCtx,0,filepath,0);
    //av_dump_format只是个调试函数，输出文件的音、视频流的基本信息了，帧率、分辨率、音频采样等等
  //printf("prepare out
");
}

int ffmpegDecode :: readOneFrame()
{
    int result = 0;
    pCvMat->release();
    result = av_read_frame(pFormatCtx, packet);
    return result;
}

cv::Mat ffmpegDecode :: getDecodedFrame()
{
    readOneFrame();
    if(packet->stream_index==videoindex)
    {
        //解码一个帧
        ret = avcodec_decode_video2(pCodecCtx, pAvFrame, &got_picture, packet);
        if(ret < 0)
        {
            printf("解码错误
");
            return cv::Mat();
        }
        if(got_picture)
        {
            m_framIndex++;
            //根据编码信息设置渲染格式
            if(img_convert_ctx == NULL){
                img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height,
                    pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height,
                    AV_PIX_FMT_BGR24, SWS_BICUBIC, NULL, NULL, NULL); 
            }   
            //----------------------opencv
            if (pCvMat->empty())
            {
                pCvMat->create(cv::Size(pCodecCtx->width, pCodecCtx->height),CV_8UC3);
            }

            if(img_convert_ctx != NULL)  
            {  
                get(pCodecCtx, img_convert_ctx, pAvFrame);
            }
        }
    }
    av_free_packet(packet);
    return *pCvMat;

}
cv::Mat ffmpegDecode :: getLastFrame()
{
    ret = avcodec_decode_video2(pCodecCtx, pAvFrame, &got_picture, packet);
    if(got_picture) 
    {  
        //根据编码信息设置渲染格式
        img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, AV_PIX_FMT_BGR24, SWS_BICUBIC, NULL, NULL, NULL); 

        if(img_convert_ctx != NULL)  
        {  
            get(pCodecCtx, img_convert_ctx,pAvFrame);
        }  
    } 
    return *pCvMat;
}

void ffmpegDecode :: get(AVCodecContext * pCodecCtx, SwsContext * img_convert_ctx, AVFrame * pFrame)
{
    if (pCvMat->empty())
    {
        pCvMat->create(cv::Size(pCodecCtx->width, pCodecCtx->height),CV_8UC3);
    }

    AVFrame *pFrameRGB = NULL;
    uint8_t  *out_bufferRGB = NULL;
    pFrameRGB = av_frame_alloc();

    //给pFrameRGB帧加上分配的内存;
    int size = avpicture_get_size(AV_PIX_FMT_BGR24, pCodecCtx->width, pCodecCtx->height);
    out_bufferRGB = new uint8_t[size];
    avpicture_fill((AVPicture *)pFrameRGB, out_bufferRGB, AV_PIX_FMT_BGR24, pCodecCtx->width, pCodecCtx->height);

    //YUV to RGB
    sws_scale(img_convert_ctx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);
    
    memcpy(pCvMat->data,out_bufferRGB,size);

    delete[] out_bufferRGB;
    av_free(pFrameRGB);
}

//crtspdecodethread.h

#ifndef CRTSPDECODETHREAD_H
#define CRTSPDECODETHREAD_H

#include <QThread>
#include <QMutex>
#include "ffmpegDecode.h"


class CRTSPDecodeThread : public QThread
{
    Q_OBJECT

public:
    CRTSPDecodeThread(QObject* parent);
    ~CRTSPDecodeThread();

    void SetCameraParam(QString, int, int cameraID);
    void run();

signals:
    void SendVideoFrame(cv::Mat);
    void SendDetectFrame(cv::Mat);

private:
    ffmpegDecode* m_pVdoDecode;
    bool m_isExist;
    unsigned long m_FrameCount;
    int m_detectInterval;

    VideoCapture m_VideoCap;

    QString m_cameraURL;
    QMutex m_Mutex;

    int m_cameraID;
    bool m_decodeInitResult;
};

#endif // CRTSPDECODETHREAD_H

//crtspdecodethread.cpp

#include "crtspdecodethread.h"
#include "ffmpegDecode.h"
#include <QDebug>
#include <QDateTime>
#include <queue>
#include <QMutexLocker>

extern bool g_ImportLib;
 std::queue<ST_IMGINFO>         g_OrgImgQueue;


CRTSPDecodeThread::CRTSPDecodeThread(QObject* parent):QThread(parent)
{
    m_isExist =  false;
}

CRTSPDecodeThread::~CRTSPDecodeThread()
{
    requestInterruption();
    quit();
    wait();

    m_isExist = true;
}

void CRTSPDecodeThread::SetCameraParam(QString strURL, int iInterval, int cameraID)
{
    m_cameraID = cameraID;
    m_detectInterval = iInterval;
    m_cameraURL =strURL;
    if(m_cameraURL == "USB")
    {
        bool bRet = m_VideoCap.open(0);
        if(!bRet)
        {
            qDebug()<<"打开USB摄像头失败...";
        }
    }
    else
    {
        m_pVdoDecode = new ffmpegDecode((char*)strURL.toStdString().c_str());
        m_decodeInitResult = m_pVdoDecode->getInitResult();
    }

}


void CRTSPDecodeThread::run()
{

    m_FrameCount = 0;

    cv::Mat img;
    unsigned long iRTSPOfflineTick = GetTickCount();
    while(!isInterruptionRequested())
    {
        if(m_isExist)
        {
            break;
        }

        if(m_cameraURL == "USB")
        {
            m_VideoCap>>img;
        }
        else
        {
            if(m_decodeInitResult)
            {
                img =m_pVdoDecode->getDecodedFrame();
            }
        }


        if(!img.empty())
        {
            m_FrameCount++;
            //cvtColor(img, img, COLOR_BGR2RGB);
            iRTSPOfflineTick = GetTickCount();

            emit SendVideoFrame(img);

            if(m_FrameCount % m_detectInterval == 0)
            {

                ST_IMGINFO imgInfo;
                 img.copyTo(imgInfo.img);

                 imgInfo.camera_id =m_cameraID;// m_pManager->GetCameraID();

                 QDateTime dtTime;
                 imgInfo.time = dtTime.currentDateTime().toString("yyyy-MM-dd HH:mm:ss");

                 QMutexLocker lock(&m_Mutex);
                 g_OrgImgQueue.push(imgInfo);

            }

            img.release();
        }
        else
        {
            qDebug()<<"获取原始视频帧失败...";

            if( (GetTickCount() -iRTSPOfflineTick ) > 1000*15)
            {
                qDebug()<<"重新打开视频流...";

                iRTSPOfflineTick = GetTickCount();

                if(m_cameraURL == "USB")
                {
                    bool bRet = m_VideoCap.open(0);
                    if(!bRet)
                    {
                        qDebug()<<"打开USB摄像头失败...";
                    }
                }
                else
                {
                    delete m_pVdoDecode;
                    m_pVdoDecode = NULL;

                     m_pVdoDecode = new ffmpegDecode((char*)m_cameraURL.toStdString().c_str());
                     m_decodeInitResult = m_pVdoDecode->getInitResult();
                }
            }
        }
    }
}