关于opencv video_reader.cpp的使用说明

How to solve OpenCV Error "function not implemented (called functionality is disabled for current build or platform) when using VideoWriter_GPU?

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <numeric>
#include <opencv2/core/core.hpp>
#include <opencv2/core/opengl_interop.hpp>
#include <opencv2/gpu/gpu.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/contrib/contrib.hpp>
using namespace cv;
using namespace gpu;
#include<iostream>
using namespace std;
int _tmain(int argc, _TCHAR* argv[])
{

std::string fname="1.avi";
string mm= cv::getBuildInformation();
cout<<mm<<endl;
cv::namedWindow("CPU", cv::WINDOW_NORMAL);
cv::namedWindow("GPU", cv::WINDOW_OPENGL);
gpu::setGlDevice();
cv::Mat frame;
cv::VideoCapture reader(fname);

cv::gpu::GpuMat d_frame;
cv::gpu::VideoReader_GPU d_reader(fname);
d_reader.dumpFormat(std::cout);

cv::TickMeter tm;
std::vector<double> cpu_times;
std::vector<double> gpu_times;

for (;;)
{
tm.reset(); tm.start();
if (!reader.read(frame))
break;
tm.stop();
cpu_times.push_back(tm.getTimeMilli());

tm.reset(); tm.start();
if (!d_reader.read(d_frame))
break;
tm.stop();
gpu_times.push_back(tm.getTimeMilli());

cv::imshow("CPU", frame);
cv::imshow("GPU", d_frame);

if (cv::waitKey(3) > 0)
break;
}

if (!cpu_times.empty() && !gpu_times.empty())
{
std::cout << std::endl << "Results:" << std::endl;

std::sort(cpu_times.begin(), cpu_times.end());
std::sort(gpu_times.begin(), gpu_times.end());

double cpu_avg = std::accumulate(cpu_times.begin(), cpu_times.end(), 0.0) / cpu_times.size();
double gpu_avg = std::accumulate(gpu_times.begin(), gpu_times.end(), 0.0) / gpu_times.size();

std::cout << "CPU : Avg : " << cpu_avg << " ms FPS : " << 1000.0 / cpu_avg << std::endl;
std::cout << "GPU : Avg : " << gpu_avg << " ms FPS : " << 1000.0 / gpu_avg << std::endl;
}
cvDestroyAllWindows();
system("pause");
return 0;
}