Question

只是使用Visual Studio 2013在PC上构建了OpenCV 3，现在我正在尝试代码，但可悲的是我不知道出了什么问题？

#include "opencv2/opencv.hpp"
#include <iostream>

using namespace std;
using namespace cv;

int main() {

    VideoCapture vcap(0);
    if (!vcap.isOpened()) {
        cout << "Error opening video stream or file" << endl;
        return -1;
    }

    int frame_width = vcap.get(cv::CAP_PROP_FRAME_WIDTH);
    int frame_height = vcap.get(cv::CAP_PROP_FRAME_HEIGHT);
    VideoWriter video("out.avi", CV_FOURCC('M', 'J', 'P', 'G'), 10, Size(frame_width, frame_height), true);

    for (;;) {

        Mat frame;
        vcap >> frame;
        video.write(frame);
        imshow("Frame", frame);
        char c = (char)waitKey(33);
        if (c == 27) break;
    }
    return 0;


1>------ Build started: Project: ConsoleApplication12, Configuration: Release x64 ------
1>  Source.cpp
1>Source.cpp(21): warning C4244: 'initializing' : conversion from 'double' to 'int', possible loss of data
1>Source.cpp(22): warning C4244: 'initializing' : conversion from 'double' to 'int', possible loss of data
1>Source.cpp(23): error C3861: 'CV_FOURCC': identifier not found
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

无法确定我要替换“ CV_FOURCC”的原因。

编辑：

int frame_width = vcap.get(cv::CAP_PROP_FRAME_WIDTH);
    int frame_height = vcap.get(cv::CAP_PROP_FRAME_HEIGHT);
    int codec = cv::VideoWriter::fourcc('M', 'J', 'P', 'G');
    VideoWriter video("out.avi", codec, 10, Size(frame_width, frame_height), true);

Answer 1

我使用了错误的OpenCV源来构建我的库。

Answer 2

看起来在OpenCV的更高版本中此更改为cv::VideoWriter::fourcc(...)，其中...是由四个字符分隔的列表。

此处提供有关OpenCV 3.4的更多信息：https://docs.opencv.org/3.4/dd/d9e/classcv_1_1VideoWriter.html#afec93f94dc6c0b3e28f4dd153bc5a7f0

OpenCV 3错误“ CV_FOURCC”：找不到标识符

2 个答案: