C语言 openCV 错误：断言失败（scn == 3 || scn == 4）
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openCV Error: Assertion failed (scn == 3 || scn == 4)
提问by MMH
I am having Assertion failed error at the last frame , while reading and writing a video frame by frame. The errors only shows at the last frame, don't know why. saw this answer here, whichs suggests to give waitkey, my code already have wait key on it.
我在最后一帧出现断言失败错误，同时逐帧读取和写入视频。错误只显示在最后一帧，不知道为什么。在这里看到这个答案，建议给waitkey，我的代码已经有了wait key。
my simple code is as follows
我的简单代码如下
int main()
{
CvCapture *capture=cvCaptureFromFile("C:\vid\op.mp4");
if(capture==NULL)
{
printf("can't open video");
}
Mat frame, first_frame,current_frame;
char buffer[100];
int frame_count=1,p=1;
while(1)
{
/*Getting the current frame from the video*/
frame=cvQueryFrame(capture);
cv::cvtColor(frame,current_frame,1); //saving current frame
sprintf(buffer,"C:\frames\image%u.jpg",p);
imwrite(buffer,current_frame);
p++;
waitKey(1);
}
return 0;
}
Anybody please help
任何人请帮忙
Solution: I added a check just after reading every file as-
解决方案：我在读取每个文件后添加了一个检查 -
if(frame.empty()){
fprinf("cannot access frame");
return -1;
}
回答by Haris
You need to check your frame is empty or not after each query
您需要在每次查询后检查您的框架是否为空
Like
喜欢
frame=cvQueryFrame(capture);
if (frame.empty()) break;
You are getting such an error because you are trying to convert an empty Mat to grayscale after last frame, so exit the loop if frame is empty.
您收到这样的错误是因为您试图在最后一帧之后将空 Mat 转换为灰度，因此如果帧为空，则退出循环。
