load_videoTrackbar.cpp

//
//  main.cpp
//  LearningOpenCV
//
//  Created by YourtionGuo on 7/28/16.
//  Copyright © 2016 Yourtion. All rights reserved.
//

#include <iostream>
#include <cv.h>
#include <highgui.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, const char * argv[]) {
    cvNamedWindow("Example3", CV_WINDOW_AUTOSIZE );
    g_capture = cvCreateFileCapture( argv[1] );
    int frames = (int) cvGetCaptureProperty(g_capture, CV_CAP_PROP_FRAME_COUNT);
    if (frames != 0) {
        cvCreateTrackbar("Position", "Example3", &g_slider_position, frames, onTrackbarSlide);
    }
    IplImage* frame;
    while (1) {
        frame = cvQueryFrame( g_capture );
        if (!frame) break;
        cvShowImage( "Example3", frame );
        char c = cvWaitKey(33);
        if ( c == 27 ) break;
    }
    cvReleaseCapture( &g_capture );
    cvDestroyWindow( "Example2" );
}