简历没有成员CAP_PROP_POS_FRAMES

Question

I'm trying to run a bit of code to add trackbars onto some video, it's from the Learning OpenCV Second Edition book, but I can't compile my code and gives the error "namespace cv has no member CAP_PROP_POS_FRAMES"

Here's the first bit of the code

#include <opencv2\highgui\highgui.hpp>
#include <opencv2\imgproc\imgproc.hpp>
#include <iostream>
#include <fstream>

using namespace std;

int g_slider_position = 0;
int g_run = 1, g_dontset = 0; //start out in a single step mode
cv::VideoCapture g_cap;

void onTrackbarSlide(int pos, void *) {
    g_cap.set(cv::CAP_PROP_POS_FRAMES, pos);
    if(!g_dontset)
        g_run = 1;
    g_dontset = 0;
}

Answer 1

It's CV_CAP_PROP_POS_FRAME (note the S) and it should be brought in by highgui.hpp. It's an unnamed enum in the global namespace.