Question

I see that this question‘s answer is really popular regarding how to print a cv::Mat image into an MFC application.

However, I was wondering if there is a memory leak there? or if there is none, how is that possible?

In specific, I’m wondering about the memset(bmih, 0, sizeof(*bmih)) part. Is it that MFC somehow manages the memory here? Can someone provide some information regarding this?

void COpenCVTestView::FillBitmapInfo(BITMAPINFO* bmi, int width, int height, int bpp, int origin) 
{ 
assert(bmi && width >= 0 && height >= 0 && (bpp == 8 || bpp == 24 || bpp == 32)); 

BITMAPINFOHEADER* bmih = &(bmi->bmiHeader); 
// this part shouldn't leak?
memset(bmih, 0, sizeof(*bmih)); 
bmih->biSize = sizeof(BITMAPINFOHEADER); 
bmih->biWidth = width; 
bmih->biHeight = origin ? abs(height) : -abs(height); 
bmih->biPlanes = 1; 
bmih->biBitCount = (unsigned short)bpp; 
bmih->biCompression = BI_RGB; 

if (bpp == 8) 
{ 
    RGBQUAD* palette = bmi->bmiColors; 

            for (int i = 0; i < 256; i++) 
    { 
        palette[i].rgbBlue = palette[i].rgbGreen = palette[i].rgbRed = (BYTE)i; 
        palette[i].rgbReserved = 0; 
    } 
} 
}

Answer 1

Where do you see a memory leak? There’s no dynamic allocation, and no
pointer manipulation. A memset coul cause a memory leak, if it
overwrote a pointer to dynamically allocated memory, but there’s no
pointer in a BITMAPINFOHEADER, just integers.