我已经选择了“学习OpenCV”,并且一直在尝试一些代码示例/练习.在这段代码片段中,我想让滑块更新其每个视频帧更改的位置,但是由于某些原因,它将无法正常工作(图片使用以下代码冻结)：
#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,char** argv)
{
cvNamedWindow("The Tom 'n Jerry Show",CV_WINDOW_AUTOSIZE);
g_capture = cvCreateFileCapture(argv[1]);
int frames = (int) cvGetCaptureProperty(
g_capture,CV_CAP_PROP_FRAME_COUNT
);
if (frames != 0)
{
cvCreateTrackbar(
"Position","The Tom 'n Jerry Show",&g_slider_position,frames,onTrackbarSlide
);
}
IplImage* frame;
while (1)
{
frame = cvQueryFrame(g_capture);
if (!frame)
break;
cvSetTrackbarPos(
"Position",++g_slider_position
);
cvShowImage("The Tom 'n Jerry Show",frame);
char c = cvWaitKey(33);
if (c == 27)
break;
}
cvReleaseCapture(&g_capture);
cvDestroyWindow("The Tom 'n Jerry Show");
return 0;
}
任何想法如何让滑块和视频按预期工作？
解决方法
This is the actual working code
// PROGRAM TO ADD A UPDATING TRACKBAR TO A VIDEO
#include <cv.h>
#include <highgui.h>
int g_slider_position = 0;
CvCapture* video_capture = NULL;
void onTrackbarSlide(int current_frame)
{
current_frame = g_slider_position;
cvSetCaptureProperty(video_capture,current_frame);
}
int main( int argc,char** argv )
{
cvNamedWindow( "Video",CV_WINDOW_AUTOSIZE );
video_capture = cvCreateFileCapture( "Crowdy.avi");
int no_of_frames = (int) cvGetCaptureProperty(video_capture,CV_CAP_PROP_FRAME_COUNT);
if( no_of_frames!= 0 )
{
cvCreateTrackbar("Slider","Video",no_of_frames,onTrackbarSlide);
}
IplImage* frame;
while(1)
{
frame = cvQueryFrame( video_capture );
if( !frame ) break;
cvShowImage( "Video",frame );
cvSetTrackbarPos("Slider",++g_slider_position);
char c = cvWaitKey(33);
if( c == 27 ) break;
}
cvReleaseCapture( &video_capture );
cvDestroyWindow( "Video" );
return(0);
}
