Opencv 入门三（视频滑动条窗口）
视频滑动条窗口源码如下：
#include "opencv2\highgui\highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
#include <fstream>
using namespace std;
int g_slider_position = 0; // 滑动条的位置
int g_run = 1, g_dontset = 0; //start out in single step mode
cv::VideoCapture g_cap;
void onTrackbarSlide(int pos, void*) {
g_cap.set(cv::CAP_PROP_POS_FRAMES, pos); //真正使进度条移动到我们希望的位置
if (!g_dontset)
g_run = 1;
g_dontset = 0;
}
int main(int argc, char** argv)
{
cv::namedWindow("Example2_4", cv::WINDOW_AUTOSIZE);
g_cap.open(string(argv[1]));
int frames = (int)g_cap.get(cv::CAP_PROP_FRAME_COUNT);
int tmpw = (int)g_cap.get(cv::CAP_PROP_FRAME_WIDTH);
int tmph = (int)g_cap.get(cv::CAP_PROP_FRAME_HEIGHT);
cout << "Video has "<<frames<<" frames of dimensions("<<tmpw<<", "<<tmph <<")."<<endl;
cv::createTrackbar("Position", "Example2_4", &g_slider_position, frames, onTrackbarSlide);
cv::Mat frame;
for (;;) {
if (g_run != 0)
{
g_cap >> frame;
if (frame.empty())break;
int current_pos = (int)g_cap.get(cv::CAP_PROP_POS_FRAMES);
g_dontset = 1;
cv::setTrackbarPos("Position", "Example2_4", current_pos);
cv::imshow("Example2_4", frame);
g_run -= 1;
}
char c = (char)cv::waitKey(10);
if (c == 's')//single step
{
g_run = 1;
cout << "Single step,run =" << g_run << endl;
}
if (c == 'r')//run mode
{
g_run = -1; cout << "Run mode,run=" << g_run << endl;
}
if (c == 27) // Esc 按键
break;
}
return 0;
}
