You need to correct several things to make it work:
You have to create the window before showing images in the window.
You have to close the writer to finish writing before open it later.
You need to add
cvWaitKey(20)
for the second image showing (check out here for why this is essential).
The whole fixed code is as follows:
#include <sstream>
#include <string>
#include <iostream>
#include <opencv/highgui.h>
#include <opencv/cv.h>
using namespace cv;
int main(int argc, char* argv[])
{
Mat inputVideo;
Mat frame;
Mat HSV;
Mat tracking;
char checkKey;
VideoCapture capture;
capture.open(0);
capture.set(CV_CAP_PROP_FRAME_WIDTH, 640);
capture.set(CV_CAP_PROP_FRAME_HEIGHT,480);
VideoWriter writer("OutputFile.mpeg", CV_FOURCC('P','I','M','1'), 50, Size(640, 480));
namedWindow("Original Video", WINDOW_AUTOSIZE );
while(1){
capture.read(inputVideo);
imshow("Original Video",inputVideo);
writer.write(inputVideo);
checkKey = cvWaitKey(20);
if(checkKey == 27)
break;
}
writer.release();
capture.open("OutputFile.mpeg");
capture.set(CV_CAP_PROP_FRAME_WIDTH, 640);
capture.set(CV_CAP_PROP_FRAME_HEIGHT,480);
namedWindow("Tracking Video", WINDOW_AUTOSIZE );
while(1){
capture.read(inputVideo);
if (!inputVideo.empty())
{
imshow("Tracking Video", inputVideo);
checkKey = cvWaitKey(20);
}
else
break;
}
return 0;
}