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/**
* @file videocapture_starter.cpp
* @brief A starter sample for using OpenCV VideoCapture with capture devices, video files or image sequences
* easy as CV_PI right?
*
* Created on: Nov 23, 2010
* Author: Ethan Rublee
*
* Modified on: April 17, 2013
* Author: Kevin Hughes
*/
#include <opencv2/imgcodecs.hpp>
#include <opencv2/videoio.hpp>
#include <opencv2/highgui.hpp>
#include <iostream>
#include <stdio.h>
using namespace cv;
using namespace std;
//hide the local functions in an anon namespace
namespace {
void help(char** av) {
cout << "The program captures frames from a video file, image sequence (01.jpg, 02.jpg ... 10.jpg) or camera connected to your computer." << endl
<< "Usage:\n" << av[0] << " <video file, image sequence or device number>" << endl
<< "q,Q,esc -- quit" << endl
<< "space -- save frame" << endl << endl
<< "\tTo capture from a camera pass the device number. To find the device number, try ls /dev/video*" << endl
<< "\texample: " << av[0] << " 0" << endl
<< "\tYou may also pass a video file instead of a device number" << endl
<< "\texample: " << av[0] << " video.avi" << endl
<< "\tYou can also pass the path to an image sequence and OpenCV will treat the sequence just like a video." << endl
<< "\texample: " << av[0] << " right%%02d.jpg" << endl;
}
int process(VideoCapture& capture) {
int n = 0;
char filename[200];
string window_name = "video | q or esc to quit";
cout << "press space to save a picture. q or esc to quit" << endl;
namedWindow(window_name, WINDOW_KEEPRATIO); //resizable window;
Mat frame;
for (;;) {
capture >> frame;
if (frame.empty())
break;
imshow(window_name, frame);
char key = (char)waitKey(30); //delay N millis, usually long enough to display and capture input
switch (key) {
case 'q':
case 'Q':
case 27: //escape key
return 0;
case ' ': //Save an image
snprintf(filename,sizeof(filename),"filename%.3d.jpg",n++);
imwrite(filename,frame);
cout << "Saved " << filename << endl;
break;
default:
break;
}
}
return 0;
}
}
int main(int ac, char** av) {
cv::CommandLineParser parser(ac, av, "{help h||}{@input||}");
if (parser.has("help"))
{
help(av);
return 0;
}
std::string arg = parser.get<std::string>("@input");
if (arg.empty()) {
help(av);
return 1;
}
VideoCapture capture(arg); //try to open string, this will attempt to open it as a video file or image sequence
if (!capture.isOpened()) //if this fails, try to open as a video camera, through the use of an integer param
capture.open(atoi(arg.c_str()));
if (!capture.isOpened()) {
cerr << "Failed to open the video device, video file or image sequence!\n" << endl;
help(av);
return 1;
}
return process(capture);
}
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