#include <cv.h>
#include <highgui.h>

using namespace std;

//記錄當前位置
int g_slider_position = 0;
CvCapture* g_capture = NULL;

void onTrackbarSlide(int pos){
	//設定視訊屬性
	cvSetCaptureProperty(g_capture, CV_CAP_PROP_POS_FRAMES, pos);
}

int main()
{
	//建立視窗
	cvNamedWindow("test_demo1", CV_WINDOW_AUTOSIZE);
	//載入檔案
	g_capture = cvCreateFileCapture("E:\\電影\\See You Again_超清.mp4");
	//獲取視訊幀數
	int frames = (int)cvGetCaptureProperty(g_capture, CV_CAP_PROP_FRAME_COUNT);
	if (frames != 0){
		//建立跟蹤條
		cvCreateTrackbar("Position", "test_demo1", &g_slider_position, frames, onTrackbarSlide);
	}
	IplImage* frame;
	while (1){
		//獲取當前幀數
		g_slider_position = (int)cvGetCaptureProperty(g_capture, CV_CAP_PROP_POS_FRAMES);
		//重新整理跟蹤條
		cvCreateTrackbar("Position", "test_demo1", &g_slider_position, frames, onTrackbarSlide);
		frame = cvQueryFrame(g_capture);
		if (!frame){
			break;
		}
		//顯示當前幀的內容
		cvShowImage("test_demo1", frame);
		//c為使用者在鍵盤上的輸入，27為esc鍵的ASCII的值
		char c = cvWaitKey(33);
		if (c == 27){
			break;
		}
	}
	//釋放空間
	cvReleaseCapture(&g_capture);
	//銷燬視窗
	cvDestroyWindow("test_demo1");

	return 0;
}