Qt+ffmpeg接受rtsp并显示

效果

接受

#include "rtspplayer.h"
#include 
VideoPlayer::VideoPlayer()
{

}

VideoPlayer::~VideoPlayer()
{
}

void VideoPlayer::run()
{
    //变量
    AVFormatContext *pFormatCtx;
    char filepath[] = "rtsp://192.168.0.188:554/stream/main";
    //初始化
    av_register_all();
    avformat_network_init();
    pFormatCtx = avformat_alloc_context();
    AVDictionary* options = NULL;
    av_dict_set(&options, "buffer_size", "1024000", 0); //设置缓存大小，1080p可将值调大
    av_dict_set(&options, "rtsp_transport", "udp", 0); //以udp方式打开，如果以tcp方式打开将udp替换为tcp
    av_dict_set(&options, "stimeout", "20000000", 0); //设置超时断开连接时间，单位微秒
    av_dict_set(&options, "max_delay", "500000", 0); //设置最大时延
    //av_dict_set(&options, "fps", "30", 0); //设置帧数
    //打开网络流或文件流
    if (avformat_open_input(&pFormatCtx, filepath, NULL, &options) != 0)
    {
        printf("Couldn't open input stream.\n");
        return;
    }
    //查找码流信息
    //设置查找时间以避免耗时过长
    pFormatCtx->probesize = 1000;
    pFormatCtx->max_analyze_duration = AV_TIME_BASE;
    if (avformat_find_stream_info(pFormatCtx, NULL)<0)
    {
        printf("Couldn't find stream information.\n");
        return;
    }
    //查找码流中是否有视频流
    int videoindex = -1;
    for (int 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.\n");
        return;
    }
    printf("-----------rtsp流输入信息--------------\n");
    av_dump_format(pFormatCtx, 0, filepath,0);
    printf("---------------------------------------\n");
    /*********************************************/
    AVCodecContext *pAVCodecContext;
    AVFrame *pAVFrame;
   	SwsContext * pSwsContext;
    AVPicture  pAVPicture;
    //获取视频流的分辨率大小
    pAVCodecContext = pFormatCtx->streams[0]->codec;
    int videoWidth=pAVCodecContext->width;
    int videoHeight=pAVCodecContext->height;  		    
    avpicture_alloc(&pAVPicture,AV_PIX_FMT_RGB32,videoWidth,videoHeight);

    AVCodec *pAVCodec;

    //获取视频流解码器
    pAVCodec = avcodec_find_decoder(pAVCodecContext->codec_id);
    pSwsContext = sws_getContext(videoWidth,videoHeight,pAVCodecContext->pix_fmt,videoWidth,videoHeight,AV_PIX_FMT_RGB32,SWS_BICUBIC,0,0,0);

      //打开对应解码器
    int result=avcodec_open2(pAVCodecContext,pAVCodec,NULL);
    if (result<0)
    {
        qDebug()<<"打开解码器失败";
        return;
    }

    pAVFrame = av_frame_alloc();
    int y_size = pAVCodecContext->width * pAVCodecContext->height;
    AVPacket *packet = (AVPacket *) malloc(sizeof(AVPacket)); //分配一个packet
    av_new_packet(packet, y_size); //分配packet的数据
    qDebug()<<"初始化视频流成功" <<","<<videoWidth << "," << videoHeight << "," ;
    
    int m_i_frameFinished =-1;
    int ret =-1;
    while(av_read_frame(pFormatCtx, packet) >= 0)
    {
        if (packet->stream_index == videoindex)
        {
            qDebug() << "pkt pts:" << packet->pts;
            ret = avcodec_decode_video2(pAVCodecContext, pAVFrame, &m_i_frameFinished, packet);
            if(ret < 0)
            {
                qDebug() << "解码失败!!";
                return;
            }
            if (m_i_frameFinished)
            {
				sws_scale(pSwsContext,(const uint8_t* const *)pAVFrame->data,pAVFrame->linesize,0,videoHeight,pAVPicture.data,pAVPicture.linesize);
                    //发送获取一帧图像信号
                QImage image(pAVPicture.data[0],videoWidth,videoHeight,QImage::Format_RGB32);
                emit sig_GetOneFrame(image);
            }
         }
      }
        av_free_packet(packet);
        msleep(0.02);
        if(pFormatCtx)
            avformat_close_input(&pFormatCtx);
        av_frame_free(&pAVFrame);
        sws_freeContext(pSwsContext);
        av_free(pAVFrame);
        printf("is end  !!! \n");
}

显示

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    m_player = new VideoPlayer;
    connect(m_player,SIGNAL(sig_GetOneFrame(QImage)),this,SLOT(slotGetOneFrame(QImage)));
    m_player->start();
}

MainWindow::~MainWindow()
{
    delete m_player;
    delete ui;
}


void MainWindow::paintEvent(QPaintEvent *event)
{
    QPainter painter(this);
    painter.setBrush(Qt::black);
    painter.drawRect(0, 0, this->width(), this->height()); //先画成黑色

    if (mImage.size().width() <= 0) return;

    ///将图像按比例缩放成和窗口一样大小
    QImage img = mImage.scaled(this->size(),Qt::KeepAspectRatio);

    int x = this->width() - img.width();
    int y = this->height() - img.height();

    x /= 2;
    y /= 2;

    painter.drawImage(QPoint(x,y),img); //画出图像

}

void MainWindow::slotGetOneFrame(QImage img)
{
    mImage = img;
    this->update(); //调用update将执行 paintEvent函数
}