OpenCv播放视频并滚动条滚动

#include "highgui.h"
#include "cv.h"

int g_slider_position = 0;
CvCapture* g_capture = NULL;

void onTrackbarSlide(int pos){
cvSetCaptureProperty(g_capture, CV_CAP_PROP_POS_FRAMES, pos);
}

int main(int argc, char** argv){
cvNamedWindow("test2", 0);
g_capture = cvCreateFileCapture(argv[1]);
int frames = (int) cvGetCaptureProperty(g_capture, CV_CAP_PROP_FRAME_COUNT);
if (frames != 0){
cvCreateTrackbar("Position", "test2", &g_slider_position, frames, onTrackbarSlide);
}
IplImage* frame;
while (1){
frame = cvQueryFrame(g_capture);
if (!frame){
break;
}
cvSetTrackbarPos("Position", "test2", g_slider_position++);
cvShowImage("test2", frame);
char c = cvWaitKey(5);
if (c == 27){
break;
}
}
cvReleaseCapture(&g_capture);
cvDestroyWindow("test2");
return 0;
}