Question

我制作了一个程序，用于在背景图像上生成移动矩形的视频。这种形状的速度由计时器功能控制。正如imshow所见，我得到的输出正确。但是我有两个问题-

如果我提高速度，就无法降低它。我可以进一步增加但不能减少。
当我尝试使用videowriter录制视频时，它会跳过帧。当我尝试降低帧速率时，它会有所改善。有没有办法像我在imshow中那样保存我的视线？

我正在Linux中使用QT。我的代码是：

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{

  sprintf(filenameImg,"/home/Workspace/TestVideoMaker/BackImages/7.jpg");


ui->setupUi(this);
imageBack= imread(filenameImg);
outputVideo.open("outcpp.avi",CV_FOURCC('M','J','P','G'),24,Size(imageBack.cols,imageBack.rows),true);
}

void MainWindow::on_pushButton_Generate_clicked()
{

initialX=MainWindowPtr->ui->lineEdit_initialX->text().toInt();
initialY=MainWindowPtr->ui->lineEdit_initialY->text().toInt();


QTimer *timer = new QTimer;

// make the connection using the timer variable
connect(timer, &QTimer::timeout, this, &generate_video);

// start the timer object by first dereferencing that object first
timer->setInterval(100-MainWindowPtr->ui->horizontalSlider_speed->value());

timer->start();
}


void generate_video()
{
heightImg = MainWindowPtr->ui->lineEdit_Height->text().toInt();
widthImg = MainWindowPtr->ui->lineEdit_Width->text().toInt();
intensity=255;
imageBack= imread(filenameImg);  //to load original background repeatedly so that it doesn't show a trail of rectangle
cvtColor(imageBack, imageBack, cv::COLOR_RGB2GRAY);
rectangle(imageBack,Point(initialX,initialY),Point(initialX+widthImg,initialY+heightImg),Scalar(intensity),-1,8,0);

imshow("image",imageBack);
if(initialX>640)
initialX=0;
else
initialX+=2;

 if(recordFlag==1)
{
    cv::cvtColor(imageBack, frame, cv::COLOR_GRAY2BGR);
    outputVideo.write(frame);
}

}

void MainWindow::on_pushButton_stop_clicked()
{
    outputVideo.release();
    timer->stop();
}

void MainWindow::on_pushButton_Record_clicked()
{
 recordFlag=1;
}

Opencv Videowriter无法如imshow所示进行写入

0 个答案: