Question

我有两台相机需要同时显示视频，无论是在单独的窗口还是在同一个窗口中。但是，使用以下代码，只显示其中一个摄像机输入（摄像机（1））。有人可以指出我的代码中需要更改的内容，或链接到其他可以达到预期效果的代码吗？

N.B。这不适用于立体视觉。

int main()
{

    //initialize and allocate memory to load the video stream from camera 
    CvCapture *capture1 = cvCaptureFromCAM(0);

    if( !capture1 ) return 1;

    //create a window with the title "Video1"
    cvNamedWindow("Video1");

    while(true) {
        //grab and retrieve each frames of the video sequentially 
        IplImage* frame1 = cvQueryFrame( capture1 );

        if( !frame1 ) break;

        //show the retrieved frame in the "Video1" window
        cvShowImage( "Video1", frame1 );

        //wait for 40 milliseconds
        int c = cvWaitKey(40);

        //exit the loop if user press "Esc" key  (ASCII value of "Esc" is 27) 
        if((char)c==27 ) break;
    }

    //initialize and allocate memory to load the video stream from camera 
    CvCapture *capture2 = cvCaptureFromCAM(1);

    if( !capture2 ) return 1;

    //create a window with the title "Video2"
    cvNamedWindow("Video2");

    while(true) {
        //grab and retrieve each frames of the video sequentially 
        IplImage* frame2 = cvQueryFrame( capture2 );

        if( !frame2 ) break;        

        //show the retrieved frame in the "Video2" window
        cvShowImage( "Video2", frame2 );

        //wait for 40 milliseconds
        int c = cvWaitKey(40);

        //exit the loop if user press "Esc" key  (ASCII value of "Esc" is 27) 
        if((char)c==27 ) break;
    }

    //destroy the opened window
    cvDestroyWindow("Video1"); 
    cvDestroyWindow("Video2");   
    //release memory
    cvReleaseCapture( &capture1 );
    cvReleaseCapture( &capture2 );

    return 0;  

    //VideoCapture1();
    //VideoCapture2();


}

Answer 1

只是澄清一下，您使用的是C还是C ++？如果您使用的是C ++，请使用OpenCV的C ++接口。

以下示例适用于我：

#include <opencv2/opencv.hpp>

int main()
{
    //initialize and allocate memory to load the video stream from camera 
    cv::VideoCapture camera0(0);
    cv::VideoCapture camera1(1);

    if( !camera0.isOpened() ) return 1;
    if( !camera1.isOpened() ) return 1;

    while(true) {
        //grab and retrieve each frames of the video sequentially 
        cv::Mat3b frame0;
        camera0 >> frame0;
        cv::Mat3b frame1;
        camera1 >> frame1;

        cv::imshow("Video0", frame0);
        cv::imshow("Video1", frame1);

        //wait for 40 milliseconds
        int c = cvWaitKey(40);

        //exit the loop if user press "Esc" key  (ASCII value of "Esc" is 27) 
        if(27 == char(c)) break;
    }

    return 0;
}

Answer 2

试试这个：

    CvCapture *capture1 = cvCaptureFromCAM(0);
    CvCapture *capture2 = cvCaptureFromCAM(1);

    if( !capture1 ) return 1;
    if (!capture2) return 1 ; 
    cvNamedWindow("Video1");
    cvNamedWindow("Video2") ;

    while(true) {
        //grab and retrieve each frames of the video sequentially 
        IplImage* frame1 = cvQueryFrame( capture1 );
        IplImage* frame2 = cvQueryFrame( capture2 );

        if( !frame1 || !frame2 ) break;

        cvShowImage( "Video1", frame1 );
        cvShowImage( "Video2", frame2 );

        //wait for 40 milliseconds
        int c = cvWaitKey(40);

        //exit the loop if user press "Esc" key  (ASCII value of "Esc" is 27) 
        if((char)c==27 ) break;
    }

Answer 3

将frame1和frame2的声明放在while循环之外

我在创建WebCam类时遇到了同样的问题。通过框架和捕获声明在单个实例中工作正常但是多个实例需要传递构造函数帧和捕获指针。

openCV看似无法多线程一些重要的设施

使用X11，BTW要获得多线程以使用cvWaitKey（），你需要链接libX11.so.6 并调用XInitThreads（）;作为main（）

中的第一条指令希望这会有所帮助戴夫莱恩。

使用opencv同时显示多个摄像头源？

3 个答案: