Question

我正在尝试使用OpenCV 2.4.6从Macbook Pro的iSight捕获帧，并使用Xcode上的Apple LLVM 4.2编译器构建。

但是，我没有收到任何帧。通常我设置一个while循环来运行，直到帧已满，但下面的一个运行约30秒没有结果。我该怎么调试呢？

void testColourCapture() {

    cv::VideoCapture capture = cv::VideoCapture(0); //open default camera
    if(!capture.isOpened()) {
        fprintf( stderr, "ERROR: ColourInput capture is NULL \n" );
    }
    cv::Mat capFrame;

    int frameWaits = 0;
    while (capFrame.empty()) {
        capture.read(capFrame);
        //capture >> capFrame;
        cvWaitKey(30);
        frameWaits++;
        std::cout << "capture >> capFrame " << frameWaits << "\n";
        if (frameWaits > 1000) {
            break;
        }
    }
    imshow("capFrame", capFrame);

}

我确保它不是多线程的。此外，capture.isOpened始终返回true。

编辑：似乎其他人遇到了这个问题：OpenCV wont' capture from MacBook Pro iSight

编辑：我安装opencv的程序是：

$ sudo port selfupdate

$ sudo port install opencv

然后，我将libopencv_core.dylib，libopencv_highgui.dylib，libopencv_imgproc.dylib和libopencv_video.dylib拖到我的Xcode项目的Frameworks文件夹中，从/ opt / local / lib

Answer 1

OpenCV 2.4.6已损坏，无法与iSight摄像头配合使用。所以安装2.4.5。我已经为此写了一个分步指南：http://accidentalprogramming.blogspot.ch/2013/10/opencv-installation-on-mac-os-x.html

Answer 2

我使用以下代码：

VideoCapture cap = VideoCapture(0); // open the video file for reading

if ( !cap.isOpened() )  // if not success, exit program
{
    cout << "Cannot open the video file" << endl;
    return -1;
}

//cap.set(CV_CAP_PROP_POS_MSEC, 300); //start the video at 300ms

double fps = cap.get(CV_CAP_PROP_FPS); //get the frames per seconds of the video

cout << "Frame per seconds : " << fps << endl;

namedWindow("MyVideo",CV_WINDOW_AUTOSIZE); //create a window called "MyVideo"

while(1)
{
    Mat frame;

    bool bSuccess = cap.read(frame); // read a new frame from video

    if (!bSuccess) //if not success, break loop
    {
        cout << "Cannot read the frame from video file" << endl;
        break;
    }

    imshow("MyVideo", frame); //show the frame in "MyVideo" window

    if(waitKey(30) == 27) //wait for 'esc' key press for 30 ms. If 'esc' key is pressed, break loop
    {
        cout << "esc key is pressed by user" << endl;
        break;
    }
}

使用Opencv从Macbook Pro iSight捕获

2 个答案: